Science.gov

Sample records for additional organic compounds

  1. Relative Stabilities of Organic Compounds Using Benson's Additivity Rules.

    ERIC Educational Resources Information Center

    Vitale, Dale E.

    1986-01-01

    Shows how the structure-energy principle can be presented in organic chemistry (without having to resort to quantum mechanics) by use of Benson's Additive Rules. Examples of the application to several major classes of organic compounds are given.

  2. Conductivity and structure of bilinear organic addition compounds

    PubMed Central

    Phillips, J. C.

    1976-01-01

    The relationship between crystal structures and metallic conductivities of linear organic materials such as tetrathiafulvalene-tetracyanoquinodimethane is explained in terms of strong lateral elastic interactions between chains. A microdomain model is presented in which at high temperatures there are, in general, two coexisting phases on each stacked molecular chain. The ordering of (in general, four) phases on two interacting chains leads to a variety of phase transitions at low temperatures. By examining temperature-dependent electrical conductivities and magnetic susceptibilities one can establish the character of each such transition. PMID:16592359

  3. Dilution standard addition calibration: A practical calibration strategy for multiresidue organic compounds determination.

    PubMed

    Martins, Manoel L; Rizzetti, Tiele M; Kemmerich, Magali; Saibt, Nathália; Prestes, Osmar D; Adaime, Martha B; Zanella, Renato

    2016-08-19

    Among calibration approaches for organic compounds determination in complex matrices, external calibration, based in solutions of the analytes in solvent or in blank matrix extracts, is the most applied approach. Although matrix matched calibration (MMC) can compensates the matrix effects, it does not compensate low recovery results. In this way, standard addition (SA) and procedural standard calibration (PSC) are usual alternatives, despite they generate more sample and/or matrix blanks consumption need, extra sample preparations and higher time and costs. Thus, the goal of this work was to establish a fast and efficient calibration approach, the diluted standard addition calibration (DSAC), based on successive dilutions of a spiked blank sample. In order to evaluate the proposed approach, solvent calibration (SC), MMC, PSC and DSAC were applied to evaluate recovery results of grape blank samples spiked with 66 pesticides. Samples were extracted with the acetate QuEChERS method and the compounds determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Results indicated that low recovery results for some pesticides were compensated by both PSC and DSAC approaches. Considering recoveries from 70 to 120% with RSD <20% as adequate, DSAC presented 83%, 98% and 100% of compounds meeting this criteria for the spiking levels 10, 50 and 100μgkg(-1), respectively. PSC presented same results (83%, 98% and 100%), better than those obtained by MMC (79%, 95% and 97%) and by SC (62%, 70% and 79%). The DSAC strategy showed to be suitable for calibration of multiresidue determination methods, producing adequate results in terms of trueness and is easier and faster to perform than other approaches. PMID:27432791

  4. Dilution standard addition calibration: A practical calibration strategy for multiresidue organic compounds determination.

    PubMed

    Martins, Manoel L; Rizzetti, Tiele M; Kemmerich, Magali; Saibt, Nathália; Prestes, Osmar D; Adaime, Martha B; Zanella, Renato

    2016-08-19

    Among calibration approaches for organic compounds determination in complex matrices, external calibration, based in solutions of the analytes in solvent or in blank matrix extracts, is the most applied approach. Although matrix matched calibration (MMC) can compensates the matrix effects, it does not compensate low recovery results. In this way, standard addition (SA) and procedural standard calibration (PSC) are usual alternatives, despite they generate more sample and/or matrix blanks consumption need, extra sample preparations and higher time and costs. Thus, the goal of this work was to establish a fast and efficient calibration approach, the diluted standard addition calibration (DSAC), based on successive dilutions of a spiked blank sample. In order to evaluate the proposed approach, solvent calibration (SC), MMC, PSC and DSAC were applied to evaluate recovery results of grape blank samples spiked with 66 pesticides. Samples were extracted with the acetate QuEChERS method and the compounds determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Results indicated that low recovery results for some pesticides were compensated by both PSC and DSAC approaches. Considering recoveries from 70 to 120% with RSD <20% as adequate, DSAC presented 83%, 98% and 100% of compounds meeting this criteria for the spiking levels 10, 50 and 100μgkg(-1), respectively. PSC presented same results (83%, 98% and 100%), better than those obtained by MMC (79%, 95% and 97%) and by SC (62%, 70% and 79%). The DSAC strategy showed to be suitable for calibration of multiresidue determination methods, producing adequate results in terms of trueness and is easier and faster to perform than other approaches.

  5. Organic Compounds

    NASA Astrophysics Data System (ADS)

    Shankland, Kenneth

    For many years, powder X-ray diffraction was used primarily as a fingerprinting method for phase identification in the context of molecular organic materials. In the early 1990s, with only a few notable exceptions, structures of even moderate complexity were not solvable from PXRD data alone. Global optimisation methods and highly-modified direct methods have transformed this situation by specifically exploiting some well-known properties of molecular compounds. This chapter will consider some of these properties.

  6. 77 FR 14279 - National Volatile Organic Compound Emission Standards for Aerosol Coatings-Addition of Dimethyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... compounds listed in Table 2A. Since publication of the final rule (73 FR 15604, March 24, 2008), compounds have been added to Table 2A following the same procedure (74 FR 29595, June 23, 2009). The amendments... other compounds listed in Table 2A (73 FR 15604, March 24, 2008; 74 FR 29595, June 23, 2009)....

  7. Fates of chlorinated volatile organic compounds in aerobic biological treatment processes: the effects of aeration and sludge addition.

    PubMed

    Chen, Wei-Hsiang; Yang, Wen-Ben; Yuan, Chung-Shin; Yang, Jun-Chen; Zhao, Qing-Liang

    2014-05-01

    The emission of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) is becoming an environmental issue of increasing concern. As biological treatment has been considered as one important approach for VOC removal, lab-scale batch experiments were conducted in this study to investigate the fates of four chlorinated hydrocarbons, including chloroform, carbon tetrachloride, trichloroethylene (TCE), and tetrachloroethylene (PERC), in the biological treatment processes with respect to the effects of aeration and sludge addition. The VOC concentrations in the phases of air, water, and sludge under four simulated treatment stages (the first sedimentation, the forepart and rear part of aerobic biological treatment, and the second sedimentation) were analyzed. The results were used to understand the three-phase partitioning of these compounds and to estimate their potentials for volatilization and biological sorption and degradation in these technologies with the concept of fugacity. It was observed that the VOCs were mainly present in the water phase through the experiments. The effects of aeration or sludge addition on the fates of these VOCs occurred but appeared to be relatively limited. The concentration distributions of the VOCs were well below the reported partitioning coefficients. It was suggested that these compounds were unsaturated in the air and sludge phases, enhancing their potentials for volatilization and biological sorption/degradation through the processes. However, the properties of these chlorinated VOCs such as the volatility, polarity, or even biodegradability caused by their structural characteristics (e.g., the number of chlorine, saturated or unsaturated) may represent more significant factors for their fates in the aerobic biological treatment processes. These findings prove the complication behind the current knowledge of VOC pollutions in WWTPs and are of help to manage the adverse impacts on the environment and public

  8. Synthesis and pharmacological screening for muscle relaxant, anticonvulsant, and sedative activities of certain organic compounds produced by Michael addition.

    PubMed

    Said, Makarem M; Ahmed, Amany A E; El-Alfy, Abir T

    2004-12-01

    Michael addition of certain nucleophiles on alpha, beta-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with alpha-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice. PMID:15646790

  9. Phytodegradation of organic compounds.

    PubMed

    Newman, Lee A; Reynolds, Charles M

    2004-06-01

    The phytodegradation of organic compounds can take place inside the plant or within the rhizosphere of the plant. Many different compounds and classes of compounds can be removed from the environment by this method, including solvents in groundwater, petroleum and aromatic compounds in soils, and volatile compounds in the air. Although still a relatively new area of research, there are many laboratories studying the underlying science necessary for a wide range of applications for plant-based remediation of organic contaminants.

  10. Group additivity values for estimating the enthalpy of formation of organic compounds: an update and reappraisal. 2. C, H, N, O, S, and halogens.

    PubMed

    Holmes, John L; Aubry, Christiane

    2012-07-01

    This study extends a previous publication on group additivity values (GAVs) for the elements C, H, and O, to include the elements nitrogen, sulfur, and the halogens. The present state and utility of the Benson additivity schemes for estimating the enthalpy of formation (Δ(f)H(0)) of organic compounds are again described, extending them to include more elements. Old and new GAVs for a wide variety of compounds are provided and are revised where necessary. When new terms are proposed, or old ones are significantly altered, the rationale for so doing is presented. GAV derived ring strain values for benzene and pyridine indicate that the aromatic stabilization of each is essentially the same. As before, the thermochemical consequences of replacing one functional group by another are also shown, thus permitting quick shortcuts to the estimation of new Δ(f)H(0) values.

  11. Organic compounds in meteorites

    NASA Technical Reports Server (NTRS)

    Anders, E.; Hayatsu, R.; Studier, M. H.

    1973-01-01

    The problem of whether organic compounds originated in meteorites as a primary condensate from a solar gas or whether they were introduced as a secondary product into the meteorite during its residence in a parent body is examined by initially attempting to reconstruct the physical conditions during condensation (temperature, pressure, time) from clues in the inorganic matrix of the meteorite. The condensation behavior of carbon under these conditions is then analyzed on the basis of thermodynamic calculations, and compounds synthesized in model experiments on the condensation of carbon are compared with those actually found in meteorites. Organic compounds in meteorites seem to have formed by catalytic reactions of carbon monoxide, hydrogen, and ammonia in the solar nebula at 360 to 400 K temperature and about 3 to 7.6 microtorr pressure. The onset of these reactions was triggered by the formation of suitable catalysts (magnetite, hydrated silicates) at these temperatures.

  12. Percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve finished-water samples containing free chlorine, 2004-10

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Bender, David A.; Price, Curtis V.

    2011-01-01

    This report presents finished-water matrix-spike recoveries of 270 anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine. Percent recoveries were calculated using analytical results from a study conducted during 2004-10 for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The study was intended to characterize the effect of quenching on finished-water matrix-spike recoveries and to better understand the potential oxidation and transformation of 270 anthropogenic organic compounds. The anthropogenic organic compounds studied include those on analytical schedules 1433, 2003, 2033, 2060, 2020, and 4024 of the USGS National Water Quality Laboratory. Three types of samples were collected from 34 NAWQA locations across the Nation: (1) quenched finished-water samples (not spiked), (2) quenched finished-water matrix-spike samples, and (3) nonquenched finished-water matrix-spike samples. Percent recoveries of anthropogenic organic compounds in quenched and nonquenched finished-water matrix-spike samples are presented. Comparisons of percent recoveries between quenched and nonquenched spiked samples can be used to show how quenching affects finished-water samples. A maximum of 18 surface-water and 34 groundwater quenched finished-water matrix-spike samples paired with nonquenched finished-water matrix-spike samples were analyzed. Percent recoveries for the study are presented in two ways: (1) finished-water matrix-spike samples supplied by surface-water or groundwater, and (2) by use (or source) group category for surface-water and groundwater supplies. Graphical representations of percent recoveries for the quenched and nonquenched finished-water matrix-spike samples also are presented.

  13. Organic compounds in meteorites

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.

    1980-01-01

    Recent studies of carbonaceous chondrites provide evidence that certain organic compounds are indigenous and the result of an abiotic, chemical synthesis. The results of several investigators have established the presence of amino acids and precursors, mono- and dicarboxylic acids, N-heterocycles, and hydrocarbons as well as other compounds. For example, studies of the Murchison and Murray meteorites have revealed the presence of at least 40 amino acids with nearly equal abundances of D and L isomers. The population consists of both protein and nonprotein amino acids including a wide variety of linear, cyclic, and polyfunctional types. Results show a trend of decreasing concentration with increasing carbon number, with the most abundant being glycine (41 n Moles/g). These and other results to be reviewed provide persuasive support for the theory of chemical evolution and provide the only natural evidence for the protobiological subset of molecules from which life on earth may have arisen.

  14. Effects of air exposure, temperature and additives on fermentation characteristics, yeast count, aerobic stability and volatile organic compounds in corn silage.

    PubMed

    Weiss, K; Kroschewski, B; Auerbach, H

    2016-10-01

    Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA

  15. Effects of air exposure, temperature and additives on fermentation characteristics, yeast count, aerobic stability and volatile organic compounds in corn silage.

    PubMed

    Weiss, K; Kroschewski, B; Auerbach, H

    2016-10-01

    Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA

  16. Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, Grorge

    2001-01-01

    Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.

  17. PERSISTENT PERFLUORINATED ORGANIC COMPOUNDS

    EPA Science Inventory

    Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consume...

  18. Energies of organic compounds

    SciTech Connect

    Wiberg, K.B.

    1995-07-01

    The studies included hydrolysis of ketals, hydration of alkenes, barrier to rotation about C-O bonds in esters and acids, hydrolysis of lactones, reduction of ketones, non-bonded interactions, and enthalpies of vaporization of ketones, ketals, and other compounds.

  19. Organic Compounds in Stardust

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Clemett. Simon J.; Sandford, Scott A.; Nakamura-Messenger, Keiko; Hoerz, Fredrich

    2011-01-01

    The successful return of the STARDUST spacecraft provides a unique opportunity to investigate the nature and distribution of organic matter in cometary dust particles collected from Comet 81P/Wild-2. Analysis of individual cometary impact tracks in silica aerogel using the technique of two-step laser mass spectrometry (L2MS) demonstrates the presence of complex aromatic organic matter. While concerns remain as to the organic purity of the aerogel collection medium and the thermal effects associated with hypervelocity capture, the majority of the observed organic species appear indigenous to the impacting particles and are hence of cometary origin. While the aromatic fraction of the total organic matter present is believed to be small, it is notable in that it appears to be N-rich. Spectral analysis in combination with instrumental detection sensitivities suggest that N is incorporated predominantly in the form of aromatic nitriles (R-C N). While organic species in the STARDUST samples do share some similarities with those present in the matrices of carbonaceous chondrites, the closest match is found with stratospherically collected interplanetary dust particles. These findings are consistent with the notion that a fraction of interplanetary dust is of cometary origin. The presence of complex organic N-containing species in comets has astrobiological implications since comets are likely to have contributed to the prebiotic chemical inventory of both the Earth and Mars.

  20. Organophosphorus Compounds in Organic Electronics.

    PubMed

    Shameem, Muhammad Anwar; Orthaber, Andreas

    2016-07-25

    This Minireview describes recent advances of organophosphorus compounds as opto-electronic materials in the field of organic electronics. The progress of (hetero-) phospholes, unsaturated phosphanes, and trivalent and pentavalent phosphanes since 2010 is covered. The described applications of organophosphorus materials range from single molecule sensors, field effect transistors, organic light emitting diodes, to polymeric materials for organic photovoltaic applications. PMID:27276233

  1. Organophosphorus Compounds in Organic Electronics.

    PubMed

    Shameem, Muhammad Anwar; Orthaber, Andreas

    2016-07-25

    This Minireview describes recent advances of organophosphorus compounds as opto-electronic materials in the field of organic electronics. The progress of (hetero-) phospholes, unsaturated phosphanes, and trivalent and pentavalent phosphanes since 2010 is covered. The described applications of organophosphorus materials range from single molecule sensors, field effect transistors, organic light emitting diodes, to polymeric materials for organic photovoltaic applications.

  2. Biomedical Compounds from Marine organisms

    PubMed Central

    Jha, Rajeev Kumar; Zi-rong, Xu

    2004-01-01

    The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.

  3. Extraterrestrial Organic Compounds in Meteorites

    NASA Technical Reports Server (NTRS)

    Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

    2003-01-01

    Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

  4. Photoprotective compounds from marine organisms.

    PubMed

    Rastogi, Rajesh P; Richa; Sinha, Rajeshwar P; Singh, Shailendra P; Häder, Donat-P

    2010-06-01

    The substantial loss in the stratospheric ozone layer and consequent increase in solar ultraviolet radiation on the earth's surface have augmented the interest in searching for natural photoprotective compounds in organisms of marine as well as freshwater ecosystems. A number of photoprotective compounds such as mycosporine-like amino acids (MAAs), scytonemin, carotenoids and several other UV-absorbing substances of unknown chemical structure have been identified from different organisms. MAAs form the most common class of UV-absorbing compounds known to occur widely in various marine organisms; however, several compounds having UV-screening properties still need to be identified. The synthesis of scytonemin, a predominant UV-A-photoprotective pigment, is exclusively reported in cyanobacteria. Carotenoids are important components of the photosynthetic apparatus that serve both light-harvesting and photoprotective functions, either by direct quenching of the singlet oxygen or other toxic reactive oxygen species or by dissipating the excess energy in the photosynthetic apparatus. The production of photoprotective compounds is affected by several environmental factors such as different wavelengths of UVR, desiccation, nutrients, salt concentration, light as well as dark period, and still there is controversy about the biosynthesis of various photoprotective compounds. Recent studies have focused on marine organisms as a source of natural bioactive molecules having a photoprotective role, their biosynthesis and commercial application. However, there is a need for extensive work to explore the photoprotective role of various UV-absorbing compounds from marine habitats so that a range of biotechnological and pharmaceutical applications can be found.

  5. Study Design and Percent Recoveries of Anthropogenic Organic Compounds With and Without the Addition of Ascorbic Acid to Preserve Water Samples Containing Free Chlorine, 2004-06

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Price, Curtis V.; Sandstrom, Mark W.

    2008-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water). Finished water is the water that is treated, which typically involves, in part, the addition of chlorine or other disinfection chemicals to remove pathogens, and is ready to be delivered to consumers. Finished water is collected before the water enters the distribution system. This report describes the study design and percent recoveries of anthropogenic organic compounds (AOCs) with and without the addition of ascorbic acid to preserve water samples containing free chlorine. The percent recoveries were determined by using analytical results from a laboratory study conducted in 2004 by the USGS's National Water Quality Laboratory (NWQL) and from data collected during 2004-06 for a field study currently (2008) being conducted by the USGS's NAWQA Program. The laboratory study was designed to determine if preserving samples with ascorbic acid (quenching samples) adversely affects analytical performance under controlled conditions. During the laboratory study, eight samples of reagent water were spiked for each of five analytical schedules evaluated. Percent recoveries from these samples were then compared in two ways: (1) four quenched reagent spiked samples analyzed on day 0 were compared with four quenched reagent spiked samples analyzed on day 7 or 14, and (2) the combined eight quenched reagent spiked samples analyzed on day 0, 7, or 14 were compared with eight laboratory reagent spikes (LRSs). Percent

  6. Photochemical dimerization of organic compounds

    SciTech Connect

    Crabtree, R.H.; Brown, S.H.; Muedas, C.A.; Ferguson, R.R.

    1992-04-14

    This patent describes improvement in a Group IIb photosensitized vapor phase dimerization of an organic compound in which a gaseous mixture of a Group IIB metal and the organic compound is irradiated in a reaction zone with a photosensitizing amount of radiant energy. The improvement comprises: a continuous stream of the gaseous mixture is passed as a vapor phase in a single pass through the reaction zone at a temperature at which the thus-produced dimer condenses immediately upon the formation thereof; the starting gaseous mixture comprises hydrogen and two ethylenically unsaturated compounds selected from the group consisting of alkenes of at least six carbon atoms, unsaturated nitriles, unsaturated epoxides, unsaturated silanes, unsaturated amines, unsaturated phosphines, and fluorinated alkenes; the gaseous mixture comprises nitrous oxide and the organic compound is a saturated compound with C-H bond strengths greater than 100 kcal/mol or a mixture of the saturated compound and an alkene; or the starting gaseous comprises an activating amount of hydrogen and the dimerization is a dehydrodimerization or cross-dimerization of a saturated hydrocarbon.

  7. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    NASA Technical Reports Server (NTRS)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  8. Students' Categorizations of Organic Compounds

    ERIC Educational Resources Information Center

    Domin, Daniel S.; Al-Masum, Mohammad; Mensah, John

    2008-01-01

    Categorization is a fundamental psychological ability necessary for problem solving and many other higher-level cognitive tasks. In organic chemistry, students must establish groupings of different chemical compounds in order not only to solve problems, but also to understand course content. Classic models of categorization emphasize similarity as…

  9. Catalyst for Oxidation of Volatile Organic Compounds

    NASA Technical Reports Server (NTRS)

    Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)

    2000-01-01

    Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

  10. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  11. Biodegradation of halogenated organic compounds.

    PubMed

    Chaudhry, G R; Chapalamadugu, S

    1991-03-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  12. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F.; Rovani, Jr., Joseph F.; Bomstad, Theresa M.; Sorini-Wong, Susan S.; Wong, Gregory K.

    2011-03-01

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  13. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F.; Rovani, Jr., Joseph F.; Bomstad, Theresa M.; Sorini-Wong, Susan S.

    2009-02-10

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  14. Additional compound semiconductor nanowires for photonics

    NASA Astrophysics Data System (ADS)

    Ishikawa, F.

    2016-02-01

    GaAs related compound semiconductor heterostructures are one of the most developed materials for photonics. Those have realized various photonic devices with high efficiency, e. g., lasers, electro-optical modulators, and solar cells. To extend the functions of the materials system, diluted nitride and bismide has been paid attention over the past decade. They can largely decrease the band gap of the alloys, providing the greater tunability of band gap and strain status, eventually suppressing the non-radiative Auger recombinations. On the other hand, selective oxidation for AlGaAs is a vital technique for vertical surface emitting lasers. That enables precisely controlled oxides in the system, enabling the optical and electrical confinement, heat transfer, and mechanical robustness. We introduce the above functions into GaAs nanowires. GaAs/GaAsN core-shell nanowires showed clear redshift of the emitting wavelength toward infrared regime. Further, the introduction of N elongated the carrier lifetime at room temperature indicating the passivation of non-radiative surface recombinations. GaAs/GaAsBi nanowire shows the redshift with metamorphic surface morphology. Selective and whole oxidations of GaAs/AlGaAs core-shell nanowires produce semiconductor/oxide composite GaAs/AlGaOx and oxide GaOx/AlGaOx core-shell nanowires, respectively. Possibly sourced from nano-particle species, the oxide shell shows white luminescence. Those property should extend the functions of the nanowires for their application to photonics.

  15. Organic compounds in star forming regions.

    PubMed

    Kochina, O; Wiebe, D

    2014-09-01

    The influence of complex dust composition on the general chemical evolution of a prestellar core and the content of complex organic compounds is studied. It is shown that various component groups respond differently to the presence of a small dust population. At early stages the difference is determined primarily by changes in the balance of photo processes due to effective absorption of ultraviolet photons by small dust grains of the second population and collisional reactions with dust particles. At later stages differences are also caused by the growing dominance of additional reaction channels related to surface organic synthesis. PMID:25515345

  16. Organic compounds in star forming regions.

    PubMed

    Kochina, O; Wiebe, D

    2014-09-01

    The influence of complex dust composition on the general chemical evolution of a prestellar core and the content of complex organic compounds is studied. It is shown that various component groups respond differently to the presence of a small dust population. At early stages the difference is determined primarily by changes in the balance of photo processes due to effective absorption of ultraviolet photons by small dust grains of the second population and collisional reactions with dust particles. At later stages differences are also caused by the growing dominance of additional reaction channels related to surface organic synthesis.

  17. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, G.D.; Moore, G.A.; Stone, M.L.; Reagen, W.K.

    1995-08-29

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs. 15 figs.

  18. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, Gregory D.; Moore, Glenn A.; Stone, Mark L.; Reagen, William K.

    1995-01-01

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs.

  19. Handbook of data on organic compounds

    SciTech Connect

    Weast, R.C.

    1985-01-01

    This book is a compilation of data on approximately 24,000 organic compounds, presented in a number of useful formats. Volumes I and II contain an alphabetical listing of compounds, giving the following information, where applicable, for each: common names and synonyms, melting and boiling point, molecular formula and weight, line formula, refractive index, density, color, crystalline form, specific rotation, solubility (greater than 10%). Since Beilstein and CAS numbers are given wherever possible, these references will also serve as a means to more in depth research. In addition, Volume II contains separate tables which group the compounds by melting point, boiling point, emperical formula, and structural formula. A separate table lists the infrared, UV, NMR, and mass spectroscopy reference numbers for major sources of curve and other spectroscopic data.

  20. Oceanic protection of prebiotic organic compounds from UV radiation

    NASA Technical Reports Server (NTRS)

    Cleaves, H. J.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1998-01-01

    It is frequently stated that UV light would cause massive destruction of prebiotic organic compounds because of the absence of an ozone layer. The elevated UV flux of the early sun compounds this problem. This applies to organic compounds of both terrestrial and extraterrestrial origin. Attempts to deal with this problem generally involve atmospheric absorbers. We show here that prebiotic organic polymers as well as several inorganic compounds are sufficient to protect oceanic organic molecules from UV degradation. This aqueous protection is in addition to any atmospheric UV absorbers and should be a ubiquitous planetary phenomenon serving to increase the size of planetary habitable zones.

  1. Oceanic protection of prebiotic organic compounds from UV radiation.

    PubMed

    Cleaves, H J; Miller, S L

    1998-06-23

    It is frequently stated that UV light would cause massive destruction of prebiotic organic compounds because of the absence of an ozone layer. The elevated UV flux of the early sun compounds this problem. This applies to organic compounds of both terrestrial and extraterrestrial origin. Attempts to deal with this problem generally involve atmospheric absorbers. We show here that prebiotic organic polymers as well as several inorganic compounds are sufficient to protect oceanic organic molecules from UV degradation. This aqueous protection is in addition to any atmospheric UV absorbers and should be a ubiquitous planetary phenomenon serving to increase the size of planetary habitable zones.

  2. Classification of additives for organic photovoltaic devices.

    PubMed

    Machui, Florian; Maisch, Philipp; Burgués-Ceballos, Ignasi; Langner, Stefan; Krantz, Johannes; Ameri, Tayebeh; Brabec, Christoph J

    2015-04-27

    The use of additives to improve the performance of organic photovoltaic cells has been intensely researched in recent years. However, so far, no system has been reported for the classification of additives and their functions. In this report, a system for classifying additives according to the fundamental mechanism by which they influence microstructure formation for P3HT:PCBM is suggested. The major parameters used for their classification are solubility and drying kinetics. Both are discussed in detail and their consequences on processing are analyzed. Furthermore, a general mechanism to classify the impact of additives on structure formation is suggested and discussed for different materials relevant to organic photovoltaic devices.

  3. Methods of making organic compounds by metathesis

    SciTech Connect

    Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

    2015-09-01

    Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

  4. Estimation of melting points of organic compounds-II.

    PubMed

    Jain, Akash; Yalkowsky, Samuel H

    2006-12-01

    A model for calculation of melting points of organic compounds from structure is described. The model utilizes additive, constitutive and nonadditive, constitutive molecular properties to calculate the enthalpy of melting and the entropy of melting, respectively. Application of the model to over 2200 compounds, including a number of drugs with complex structures, gives an average absolute error of 30.1 degrees.

  5. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  6. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  7. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  8. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  9. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  10. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  11. Microwave plasma conversion of volatile organic compounds.

    PubMed

    Ko, Youngsam; Yang, Gosu; Chang, Daniel P Y; Kennedy, Ian M

    2003-05-01

    A microwave-induced, steam/Ar/O2, plasma "torch" was operated at atmospheric pressure to determine the feasibility of destroying volatile organic compounds (VOCs) of concern. The plasma process can be coupled with adsorbent technology by providing steam as the fluid carrier for desorbing the VOCs from an adsorbent. Hence, N2 can be excluded by using a relatively inexpensive carrier gas, and thermal formation of oxides of nitrogen (NOx) is avoided in the plasma. The objectives of the study were to evaluate the technical feasibility of destroying VOCs from gas streams by using a commercially available microwave plasma torch and to examine whether significant byproducts were produced. Trichloroethene (TCE) and toluene (TOL) were added as representative VOCs of interest to a flow that contained Ar as a carrier gas in addition to O2 and steam. The O2 was necessary to ensure that undesirable byproducts were not formed in the process. Microwave power applied at 500-600 W was found to be sufficient to achieve the destruction of the test compounds, down to the detection limits of the gas chromatograph that was used in the analysis. Samples of the postmicrowave gases were collected on sorbent tubes for the analysis of dioxins and other byproducts. No hazardous byproducts were detected when sufficient O2 was added to the flow. The destruction efficiency at a fixed microwave power improved with the addition of steam to the flow that passed through the torch.

  12. Organic electronic devices using phthalimide compounds

    DOEpatents

    Hassan, Azad M.; Thompson, Mark E.

    2013-03-19

    Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

  13. Organic electronic devices using phthalimide compounds

    DOEpatents

    Hassan, Azad M.; Thompson, Mark E.

    2012-10-23

    Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

  14. Organic electronic devices using phthalimide compounds

    DOEpatents

    Hassan, Azad M.; Thompson, Mark E.

    2010-09-07

    Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

  15. VOLATILE ORGANIC COMPOUNDS AS EXPOSURE BIOMARKERS

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the US Environmental Protection Agency's National Exposure Research Laboratory have developed and refined...

  16. Microwave spectra of some volatile organic compounds

    NASA Technical Reports Server (NTRS)

    White, W. F.

    1975-01-01

    A computer-controlled microwave (MRR) spectrometer was used to catalog reference spectra for chemical analysis. Tables of absorption frequency, peak absorption intensity, and integrated intensity are included for 26 volatile organic compounds, all but one of which contain oxygen.

  17. Energies of organic compounds. Final report

    SciTech Connect

    1995-07-01

    The objective of this research was to gain information on the energies of organic compounds and on the factors that control energies. The work involved calorimetric measurements of energy changes and theoretical studies of intramolecular interactions and molecular energies.

  18. PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH

    EPA Science Inventory

    A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

  19. (CHINA) PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH

    EPA Science Inventory

    A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

  20. Volatile organic compound emissions from silage systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major 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...

  1. VOLATILE ORGANIC COMPOUNDS (VOCS) CHAPTER 31.

    EPA Science Inventory

    The term "volatile organic compounds' (VOCs) was originally coined to refer, as a class, to carbon-containing chemicals that participate in photochemical reactions in the ambient (outdoor) are. The regulatory definition of VOCs used by the U.S. EPA is: Any compound of carbon, ex...

  2. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  3. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  4. Antioxidant combinations of molybdenum complexes and organic sulfur compounds for lubricating oils

    SciTech Connect

    deVries, L.; King, J.M.

    1983-09-06

    An antioxidant additive combination for lubricating oils is prepared by combining (a) a sulfur containing molybdenum compound prepared by reacting an ammonium tetrathiomolybdate, and a basic nitrogen compound, with (b) an organic sulfur compound.

  5. Microbial removal of hazardous organic compounds

    SciTech Connect

    Kobayashi, H.; Rittman, B.E.

    1982-03-01

    An in-depth evaluation of the potential for microorganisms to remove anthropogenic organic compounds, mainly priority pollutants and related compounds, is presented. The evaluation indicates that use of properly selected populations of microbes, and the maintenance of environmental conditions most conducive to their metabolism, can be an important means of improving biological treatment of organic wastes. One major theme is that microorganisms not normally associated with biological waste treatment have potential advantages when the removal of anthropogenic compounds is the goal. An extensive summary of examples of anthropogenic compounds and microorganisms that can attack them is presented in tabular form. A second table lists the selective uses of microorganisms for removal of different anthropogenic compounds. (KRM)

  6. Enantiomeric and Isotopic Analysis of Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, George

    2004-01-01

    Carbonaceous meteorites are relatively enriched in soluble organic compounds. The Murchison and Murray meteorites contain numerous compounds of interest in the study of early solar system organic chemistry and organic compounds of potential importance for the origin of life. These include: amino acids, amides, carboxylic acids, and polyols. This talk will focus on the enantiomeric and isotopic analysis of individual meteoritic compounds - primarily polyol acids. The analyses will determine if, in addition to certain amino acids from Murchison, another potentially important class of prebiotic compounds also contains enantiomeric excesses, i.e., excesses that could have contributed to the current homochirality of life. Preliminary enantiomeric and isotopic (C- 13) measurements of Murchison glyceric acid show that it is indeed extraterrestrial. C-13 and D isotope analysis of meteoritic sugar alcohols (glycerol, threitol, ribitol, etc.) has shown that they are also indigenous to the meteorite.

  7. Air sparging of organic compounds in groundwater

    SciTech Connect

    Hicks, P.M.

    1994-12-31

    Soils and aquifers containing organic compounds have been traditionally treated by excavation and disposal of the soil and/or pumping and treating the groundwater. These remedial options are often not practical or cost effective solutions. A more favorable alternative for removal of the adsorbed/dissolved organic compounds would be an in situ technology. Air sparging will remove volatile organic compounds from both the adsorbed and dissolved phases in the saturated zone. This technology effectively creates a crude air stripper below the aquifer where the soil acts as the ``packing``. The air stream that contacts dissolved/adsorbed phase organics in the aquifer induces volatilization. A case history illustrates the effectiveness of air sparging as a remedial technology for addressing organic compounds in soil and groundwater. The site is an operating heavy equipment manufacturing facility in central Florida. The soil and groundwater below a large building at the facility was found to contain primarily diesel type petroleum hydrocarbons during removal of underground storage tanks. The organic compounds identified in the groundwater were Benzene, Xylenes, Ethylbenzene and Toluenes (BTEX), Methyl tert-Butyl Ether (MTBE) and naphthalenes in concentrations related to diesel fuel.

  8. Photocatalytic oxidation of organic compounds on Mars

    NASA Technical Reports Server (NTRS)

    Chun, S. F. S.; Pang, K. D.; Cutts, J. A.; Ajello, J. M.

    1978-01-01

    Ultraviolet-stimulated catalytic oxidation is proposed as a mechanism for the destruction of organic compounds on Mars. The process involves the presence of gaseous oxygen, UV radiation, and a catalyst (titanium dioxide), and all three of these have been found to be present in the Martian environment. Therefore it seems plausible that UV-stimulated oxidation of organics is responsible for degrading organic molecules into inorganic end products.

  9. Reflectance spectroscopy of organic compounds: 1. Alkanes

    USGS Publications Warehouse

    Clark, R.N.; Curchin, J.M.; Hoefen, T.M.; Swayze, G.A.

    2009-01-01

    Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first in a series of papers to build a spectral database of organic compounds for use in remote sensing studies. Applications range from mapping the environment on the Earth, to the search for organic molecules and life in the solar system and throughout the. universe. We show that the spectral reflectance properties of organic compounds are rich, with major diagnostic spectral features throughout the spectral range studied. Little to no spectral change was observed as a function of temperature and only small shifts and changes in the width of absorption bands were observed between liquids and solids, making remote detection of spectral properties throughout the solar system simpler. Some high molecular weight organic compounds contain single-bonded carbon chains and have spectra similar to alkanes even ' when they fall into other families. Small spectral differences are often present allowing discrimination among some compounds, further illustrating the need to catalog spectral properties for accurate remote sensing identification with spectroscopy.

  10. Stabilization of Long-Range Order by Additional Anisotropic Spins in Two-Dimensional Isotropic Heisenberg Antiferromagnets —A Possible Model of an Organic Compound with Magnetic Anions—

    NASA Astrophysics Data System (ADS)

    Shimahara, Hiroshi; Ito, Kazuhiro

    2014-11-01

    We examine a two-dimensional (2D) coupled antiferromagnetic (AF) Heisenberg model that consists of two subsystems: an isotropic S = 1/2 spin subsystem with strong AF exchange interactions (main system), and a uniaxial S = 5/2 spin subsystem with weak exchange interactions. This model is an example in which additional semiclassical degrees of freedom affect a quantum system; it also describes a possible stabilization mechanism of AF long-range order (LRO) in the 2D organic compound λ-(BETS)2FeCl4, where BETS stands for bis(ethylenedithio)tetraselenafulvalene. Previous experimental studies have revealed that 3d spins on FeCl4 anions passively follow the AF LRO of the π-electron system in the BETS layers, although the AF LRO is stabilized by the 3d spins themselves. To explain this paradoxical behavior, we examine a scenario in which the uniaxial anisotropy of the 3d spins stabilizes the AF LRO on an isotropic 2D π-spin system. We extend Green's function theory, called the Tyablikov approximation, to the present system, which describes spin-wave excitations and is consistent with the Mermin-Wagner theorem. It is shown that even extremely weak interactions with the uniaxial subsystem efficiently stabilize the AF LRO in the main system, even in the absence of AF exchange interactions in the uniaxial subsystem. The AF LRO is triggered by the uniaxial subsystem, but the sublattice magnetization remains smaller than that of the main system in the high-temperature region. These results are consistent with experimental data for λ-(BETS)2FeCl4 and λ-(BETS)2GaCl4; the latter does not have the 3d spins and does not exhibit the AF LRO.

  11. Occupational health experience with organic additives.

    PubMed

    Thiess, A M; Wellenreuther, G

    1984-12-01

    For many decades, interest in occupational medicine has been focused on the wide variety of organic additives, which includes a large number of substances, for example, dyestuffs, pigments, and auxiliaries for the textile, leather, and paper industries. The reason is that, if the recommended precautions are not observed, there is a risk of exposure to most of these substances during both production and use. Moreover, over the years, some additives have caused concern and aroused suspicion regarding adverse effects on health. In order to deal with health problems in this field, it is important to be aware of how, what, and where occupational diseases or accidents arise. Much knowledge has been gained about these, and it would be an impossible task to give a systematic survey of the data that have accumulated, especially since it is necessary to take account of the problem of exposure to more than one substance. Thus an attempt is made to report on occupational health experience in general, and to demonstrate how an industrial hygienist may approach the many and various problems. Some epidemiological studies on organic additives (auramine, anthraquinone dyestuffs, organic dyes, etc.) are discussed.

  12. Nonaqueous battery with organic compound cathode

    SciTech Connect

    Yamaji, A.; Yamaki, J.

    1981-02-17

    A battery embodying this invention comprises: an anode including an anode-active material formed of one metal selected from the Group IA metals or preferably lithium metal; a cathode including a cathode-active material formed of metal or metal-free organic compounds having a phthalocyanine function or organic compounds having a porphin function; and an electrolyte prepared from a material which is chemically stable to the cathode and anode materials and permits the migration of the ion of the anode metal to the cathode for electrochemical reaction with the cathode-active material.

  13. Molecular and Enantiomeric Analysis of Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, George

    2003-01-01

    Carbonaceous meteorites are relatively enriched in carbon. Much of this carbon is in the form of soluble organic compounds. The Murchison and Murray meteorites are the best-characterized carbonaceous meteorites with respect to organic chemistry. Their content of organic compounds has led to an initial understanding of early solar system organic chemistry as well as what compounds may have played a role in the origin of life (Cronin and Chang, 1993). Reported compounds include: amino acids, amides, carboxylic acids, sulfonic acids, and polyols. This talk will focus on the molecular and enantiomeric analysis of individual meteoritic compounds: polyol acids; and a newly identified class of meteorite compounds, keto acids, i.e., acetoacetic acid, levulinic acid, etc. Keto acids (including pyruvic) are critically important in all contemporary organisms. They are key intermediates in metabolism and processes such as the citric acid cycle. Using gas chromatography-mass spectrometry we identified individual meteoritic keto acids after derivatization to one or more of the following forms: isopropyl ester (ISP), trimethyIsiIy1 (TMS), tert-butyldimethylsilyl (BDMS). Ongoing analyses will determine if, in addition to certain amino acids from Murchison (Cronin and Pizzarello, 1997), other potentially important prebiotic compounds also contain enantiomeric excesses, i.e., excesses that could have contributed to the current homochirality of life.

  14. Metastable Equilibria Among Aqueous Organic Compounds

    NASA Astrophysics Data System (ADS)

    Shock, E.; Shipp, J.; Yang, Z.; Gould, I. R.

    2011-12-01

    Metastable equilibrium states exist when reactions among a subset of compounds in a chemical system are reversible even though other irreversible reactions exist in the same system. The existence of metastable equilibrium among organic compounds was initially detected by comparing ratios of organic acid concentrations reported for oil-field brines (Shock, 1988, Geology 16, 886-890; Shock, 1989, Geology 17, 572-573), and calculating the same ratios for likely oxidation states determined by mineral assemblages and mixtures of hydrocarbons in coexisting petroleum (Shock, 1994, in: The Role of Organic Acids in Geological Processes, Springer). This led to the notion of extending the concept of metastable equilibrium states to explicitly account for petroleum compositions (Helgeson et al., 1993, GCA, 57, 3295-3339), which eventually yielded the concept of hydrolytic disproportionation of kerogens to produce petroleum and CO2(g) (Helgeson et al., 2009, GCA, 73, 594-695). Experimental tests of metastable equilibrium among organic compounds began with the identification of reversible reactions between alkanes and alkenes that are dependent on the H2 fugacity of the experimental system (Seewald, 1994, Nature 370, 285-287). These were followed with a comprehensive series of long-term experiments leading to the hypothesis that reversible reactions include alkanes, alkenes, alcohol, aldehydes, ketones and carboxylic acids (e.g., Seewald, 2001, GCA 65, 1641-1664; 2003, Nature 426, 327-333; McCollom & Seewald, 2003, GCA 67, 3645-3664). We have conducted sets of hydrothermal organic transformation experiments that test the extent to which these reactions are indeed reversible using aromatic and cyclic compounds. Results demonstrate reversibility for reactions among dibenzyl ketone, 1,3-diphenyl-2-propanol, 1,3-diphenylpropene and 1,3-diphenylpropane, as well as among methylcyclohexanes, methylcyclohexenes, methylcyclohexanols, methylcyclohexanones and methylcyclohexadienes. The

  15. Chlorinated organic compounds produced by Fusarium graminearum.

    PubMed

    Ntushelo, Khayalethu

    2016-06-01

    Fusarium graminearum, a pathogen of wheat and maize, not only reduces grain yield and degrades quality but also produces mycotoxins in the infected grain. Focus has been on mycotoxins because of the human and animal health hazards associated with them. In addition to work done on mycotoxins, chemical profiling of F. graminearum to identify other compounds produced by this fungus remains critical. With chemical profiling of F. graminearum the entire chemistry of this fungus can be understood. The focus of this work was to identify chlorinated compounds produced by F. graminearum. Various chlorinated compounds were detected and their role in F. graminearum is yet to be understood.

  16. Simulation of comet particulates from organic compounds

    NASA Astrophysics Data System (ADS)

    Kajmakov, E. A.; Lizunkova, I. S.; Dranerich, V. A.

    1981-02-01

    A laboratory study of the sublimation of aqueous solutions of several organic compounds (urea, glycine, and phenylalanine) that might occur in comet nuclei is described. The molecules of the organic materials are found to form acicular crystals. If the concentration of the initial solution is reduced the acicular crystals will grow longer. The presence of elongated grains in comet atmospheres could explain certain polarization characteristics of comet radiation.

  17. Ultraviolet radiation absorbing compounds in marine organisms

    SciTech Connect

    Chalker, B.E.; Dunlap, W.C. )

    1990-01-09

    Studies on the biological effects of solar ultraviolet radiations are becoming increasingly common, in part due to recent interest in the Antarctic ozone hole and in the perceived potential for global climate change. Marine organisms possess many strategies for ameliorating the potentially damaging effects of UV-B (280-320 nm) and the shorter wavelengths of UV-A (320-400nm). One mechanism is the synthesis of bioaccumulation of ultraviolet radiation absorbing compounds. Several investigators have noted the presence of absorbing compounds in spectrophotometer scans of extracts from a variety of marine organisms, particularly algae and coelenterates containing endosymbiotic algae. The absorbing compounds are often mycosporine-like amino acids. Thirteen mycosporine-like amino acids have already been described, and several others have recently been detected. Although, the mycosporine-like amino acids are widely distributed. these compounds are by no means the only type of UV-B absorbing compounds which has been identified. Coumarins from green algae, quinones from sponges, and indoles from a variety of sources are laternative examples which are documented in the natural products literature. When the biological impact of solar ultraviolet radiation is assessed, adequate attention must be devoted to the process of photoadaptation, including the accumulation of ultraviolet radiation absorbing compounds.

  18. Chlorinated organic compounds in urban river sediments

    SciTech Connect

    Soma, Y.; Shiraishi, H.; Inaba, K.

    1995-12-31

    Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

  19. Additive manufacturing: From implants to organs.

    PubMed

    Douglas, Tania S

    2014-06-01

    Additive manufacturing (AM) constructs 3D objects layer by layer under computer control from 3D models. 3D printing is one example of this kind of technology. AM offers geometric flexibility in its products and therefore allows customisation to suit individual needs. Clinical success has been shown with models for surgical planning, implants, assistive devices and scaffold-based tissue engineering. The use of AM to print tissues and organs that mimic nature in structure and function remains an elusive goal, but has the potential to transform personalised medicine, drug development and scientific understanding of the mechanisms of disease.  PMID:25214247

  20. Additive manufacturing: From implants to organs.

    PubMed

    Douglas, Tania S

    2014-05-12

    Additive manufacturing (AM) constructs 3D objects layer by layer under computer control from 3D models. 3D printing is one example of this kind of technology. AM offers geometric flexibility in its products and therefore allows customisation to suit individual needs. Clinical success has been shown with models for surgical planning, implants, assistive devices and scaffold-based tissue engineering. The use of AM to print tissues and organs that mimic nature in structure and function remains an elusive goal, but has the potential to transform personalised medicine, drug development and scientific understanding of the mechanisms of disease. 

  1. Volatile organic compounds from leaves litter.

    PubMed

    Isidorov, Valery; Jdanova, Maria

    2002-09-01

    Qualitative composition of volatile emissions of litter of five species of deciduous trees was investigated by GC-MS. The list of identified substances contains more than 70 organic compounds of various classes. It was established that the composition of components emitted by the litter into the gas phase greatly differs from that of essential oils extracted by hydrodistillation from turned leaves collected from trees during fall. It is suggested that most compounds found in litter emissions are products of vital activity of microorganisms decomposing it. The reported data indicate that after the vegetative period is over the decomposition processes of litter are important seasonal sources of reactive organic compounds under the forest canopy.

  2. Catalytic Destruction Of Toxic Organic Compounds

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.

    1990-01-01

    Proposed process disposes of toxic organic compounds in contaminated soil or carbon beds safely and efficiently. Oxidizes toxic materials without producing such other contaminants as nitrogen oxides. Using air, fuel, catalysts, and steam, system consumes less fuel and energy than decontamination processes currently in use. Similar process regenerates carbon beds used in water-treatment plants.

  3. Cyanoethylated Compounds as Additives in Lithium/Lithium Ion Batteries

    SciTech Connect

    Nagasubramanian, Ganesan

    1998-05-08

    The power loss of lithium/lithium ion battery cells is significantly reduced, especially at low temperatures, when about 1% by weight of an additive is incorporated in the electrolyte layer of the cells. The usable additives are organic solvent soluble cyanoethylated polysaccharides and poly(vinyl alcohol). The power loss decrease results primarily from the decrease in the charge transfer resistance at the interface between the electrolyte and the cathode.

  4. Cyanoethylated compounds as additives in lithium/lithium batteries

    DOEpatents

    Nagasubramanian, Ganesan

    1999-01-01

    The power loss of lithium/lithium ion battery cells is significantly reduced, especially at low temperatures, when about 1% by weight of an additive is incorporated in the electrolyte layer of the cells. The usable additives are organic solvent soluble cyanoethylated polysaccharides and poly(vinyl alcohol). The power loss decrease results primarily from the decrease in the charge transfer resistance at the interface between the electrolyte and the cathode.

  5. Improving rubber concrete by waste organic sulfur compounds.

    PubMed

    Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

    2010-01-01

    In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly. PMID:19710121

  6. Improving rubber concrete by waste organic sulfur compounds.

    PubMed

    Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

    2010-01-01

    In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly.

  7. Characterizations of organic compounds in diesel exhaust particulates.

    PubMed

    Lim, Jaehyun; Lim, Cheolsoo; Kim, Sangkyun; Hong, Jihyung

    2015-08-01

    To characterize how the speed and load of a medium-duty diesel engine affected the organic compounds in diesel particle matter (PM) below 1 μm, four driving conditions were examined. At all four driving conditions, concentration of identifiable organic compounds in PM ultrafine (34-94 nm) and accumulation (94-1000 nm) modes ranged from 2.9 to 5.7 μg/m(3) and 9.5 to 16.4 μg/m(3), respectively. As a function of driving conditions, the non-oxygen-containing organics exhibited a reversed concentration trend to the oxygen-containing organics. The identified organic compounds were classified into eleven classes: alkanes, alkenes, alkynes, aromatic hydrocarbons, carboxylic acids, esters, ketones, alcohols, ethers, nitrogen-containing compounds, and sulfur-containing compounds. At all driving conditions, alkane class consistently showed the highest concentration (8.3 to 18.0 μg/m(3)) followed by carboxylic acid, esters, ketones and alcohols. Twelve polycyclic aromatic hydrocarbons (PAHs) were identified with a total concentration ranging from 37.9 to 174.8 ng/m(3). In addition, nine nitrogen-containing polycyclic aromatic compounds (NPACs) were identified with a total concentration ranging from 7.0 to 10.3 ng/m(3). The most abundant PAH (phenanthrene) and NPACs (7,8-benzoquinoline and 3-nitrophenanthrene) comprise a similar molecular (3 aromatic-ring) structure under the highest engine speed and engine load. PMID:26257360

  8. Characterizations of organic compounds in diesel exhaust particulates.

    PubMed

    Lim, Jaehyun; Lim, Cheolsoo; Kim, Sangkyun; Hong, Jihyung

    2015-08-01

    To characterize how the speed and load of a medium-duty diesel engine affected the organic compounds in diesel particle matter (PM) below 1 μm, four driving conditions were examined. At all four driving conditions, concentration of identifiable organic compounds in PM ultrafine (34-94 nm) and accumulation (94-1000 nm) modes ranged from 2.9 to 5.7 μg/m(3) and 9.5 to 16.4 μg/m(3), respectively. As a function of driving conditions, the non-oxygen-containing organics exhibited a reversed concentration trend to the oxygen-containing organics. The identified organic compounds were classified into eleven classes: alkanes, alkenes, alkynes, aromatic hydrocarbons, carboxylic acids, esters, ketones, alcohols, ethers, nitrogen-containing compounds, and sulfur-containing compounds. At all driving conditions, alkane class consistently showed the highest concentration (8.3 to 18.0 μg/m(3)) followed by carboxylic acid, esters, ketones and alcohols. Twelve polycyclic aromatic hydrocarbons (PAHs) were identified with a total concentration ranging from 37.9 to 174.8 ng/m(3). In addition, nine nitrogen-containing polycyclic aromatic compounds (NPACs) were identified with a total concentration ranging from 7.0 to 10.3 ng/m(3). The most abundant PAH (phenanthrene) and NPACs (7,8-benzoquinoline and 3-nitrophenanthrene) comprise a similar molecular (3 aromatic-ring) structure under the highest engine speed and engine load.

  9. Secondary organic aerosol from biogenic volatile organic compound mixtures

    NASA Astrophysics Data System (ADS)

    Hatfield, Meagan L.; Huff Hartz, Kara E.

    2011-04-01

    The secondary organic aerosol (SOA) yields from the ozonolysis of a Siberian fir needle oil (SFNO), a Canadian fir needle oil (CFNO), and several SOA precursor mixtures containing reactive and non-reactive volatile organic compounds (VOCs) were investigated. The use of precursor mixtures more completely describes the atmosphere where many VOCs exist. The addition of non-reactive VOCs such as bornyl acetate, camphene, and borneol had very little to no effect on SOA yields. The oxidation of VOC mixtures with VOC mass percentages similar to the SFNO produced SOA yields that became more similar to the SOA yield from SFNO as the complexity and concentration of VOCs within the mixture became more similar to overall SFNO composition. The SOA yield produced by the oxidation of CFNO was within the error of the SOA yield produced by the oxidation of SFNO at a similar VOC concentration. The SOA yields from SFNO were modeled using the volatility basis set (VBS), which predicts the SOA yields for a given mass concentration of mixtures containing similar VOCs.

  10. Organic photosensitive devices using subphthalocyanine compounds

    DOEpatents

    Rand, Barry; Forrest, Stephen R.; Mutolo, Kristin L.; Mayo, Elizabeth; Thompson, Mark E.

    2011-07-05

    An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.

  11. Climate impacts of biogenic organic compounds

    NASA Astrophysics Data System (ADS)

    Sengupta, Kamalika; Gordon, Hamish; Almeida, Joao; Rap, Alex; Scott, Catherine; Pringle, Kirsty; Carslaw, Ken

    2016-04-01

    Currently the most uncertain driver of climate change, impact of anthropogenic aerosols on earth's radiative balance depends significantly on estimates of cloud condensation nuclei (CCN), representation of the pre-industrial atmosphere among others. Nearly 90% of aerosols in the tropics are organic in nature of which a major part comes from biogenic sources. About 45% of the CCN in the atmosphere are formed in-situ via nucleation. Understanding the role of biogenic organic compounds in particle formation and their subsequent growth is hence imperative in order to quantify the climate impact of aerosols. The CLOUD experiment at CERN, which measures particle formation and growth rates in a uniquely clean chamber under atmospherically relevant conditions, found evidence of a nucleation mechanism involving only biogenic organic compounds. This mechanism significantly changes our pre-industrial estimates. The experimental results have been parameterized and included in a global aerosol microphysics model, GLOMAP, to quantify the impact of pure biogenic nucleation on CCN formation and their climatic impact. Further the treatment of secondary organic compounds in GLOMAP has been improved and the sensitivity of our estimates of radiative forcing to the same has been evaluated.

  12. Organic Phosphorus Characterisation in Agricultural Soils by Enzyme Addition Assays

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus; Frossard, Emmanuel; Bünemann, Else K.

    2013-04-01

    Phosphorus (P) is a non-renewable resource and it is a building block of many molecules indispensable for life. Up to 80 per cent of total soil P can be in organic form. Hydrolysability and thereby availability to plants and microorganisms differ strongly among the multitude of chemical forms of soil organic P. A recent approach to characterise organic P classes is the addition of specific enzymes which hydrolyse organic P to inorganic orthophosphate, making it detectable by colorimetry. Based on the substrate specificity of the added enzymes, conclusions about the hydrolysed forms of organic P can then be made. The aim of this study was to determine the applicability of enzyme addition assays for the characterisation of organic P species in soil:water suspensions of soils with differing properties. To this end, ten different soil samples originating from four continents, with variable pH (in water) values (4.2-8.0), land management (grassland or cropped land) and P fertilization intensity were analysed. Three different enzymes were used (acid phosphatase, nuclease and phytase). Acid phosphatase alone or in combination with nuclease was applied to determine the content of P in simple monoesters (monoester-like P) and P in DNA (DNA-like P), while P hydrolysed from myo-inositol hexakisphosphate (Ins6P-like P) was calculated from P release after incubation with phytase minus P release by acid phosphatase. To reduce sorption of inorganic P on soil particles of the suspension, especially in highly weathered soils, soil specific EDTA additions were determined in extensive pre-tests. The results of these pre-tests showed that recoveries of at least 30 per cent could be achieved in all soils. Thus, detection of even small organic P pools, such as DNA-like P, was possible in all soils if a suitable EDTA concentration was chosen. The enzyme addition assays provided information about the hydrolysable quantities of the different classes of soil organic P compounds as affected

  13. Toxic organic compounds from energy production

    SciTech Connect

    Hites, R.A.

    1991-09-20

    The US Department of Energy's Office of Health and Environmental Research (OHER) has supported work in our laboratory since 1977. The general theme of this program has been the identification of potentially toxic organic compounds associated with various combustion effluents, following the fates of these compounds in the environment, and improving the analytical methodology for making these measurements. The projects currently investigation include: an improved sampler for semi-volatile compounds in the atmosphere; the wet and dry deposition of dioxins and furans from the atmosphere; the photodegradation and mobile sources of dioxins and furans; and the bioaccumulation of PAH by tree bark. These projects are all responsive to OHER's interest in the pathways and mechanisms by which energy-related agents move through and are modified by the atmosphere''. The projects on gas chromatographic and liquid chromatographic tandem mass spectrometry are both responsive to OHER's interest in new and more sensitive technologies for chemical measurements''. 35 refs., 9 figs.

  14. Predicting the octanol solubility of organic compounds.

    PubMed

    Admire, Brittany; Yalkowsky, Samuel H

    2013-07-01

    The molar octanol solubility of an organic nonelectrolytes can be reasonably predicted solely from its melting point provided that its liquid (or a hypothetical super-cooled liquid) form is miscible with octanol. The aim of this work is to develop criteria to determine if the real or hypothetical liquid form of a given compound will be miscible with octanol based on its molar volume and solubility parameter. Fortunately, most organic compounds (including most drugs) conform to the criteria for complete liquid miscibility, and therefore have solubilities that are proportional to their melting points. The results show that more than 95% of the octanol solubilities studied are predicted with an error of less than 1 logarithmic unit.

  15. Compositional space boundaries for organic compounds.

    PubMed

    Lobodin, Vladislav V; Marshall, Alan G; Hsu, Chang Samuel

    2012-04-01

    An upper elemental compositional boundary for fossil hydrocarbons has previously been established as double-bond equivalents (i.e., DBE = rings plus double bonds) not exceeding 90% of the number of carbons. For heteroatom-containing fossil compounds, the 90% rule still applies if each N atom is counted as a C atom. The 90% rule eliminates more than 10% of the possible elemental compositions at a given mass for fossil database molecules. However, some synthetic compounds can fall outside the upper boundary defined for naturally occurring compounds. Their inclusion defines an "absolute" upper boundary as DBE (rings plus double bonds to carbon) equal to carbon number plus one, and applies to all organic compounds including fullerenes and other molecules containing no hydrogen. Finally, the DBE definition can fail for molecules with particular atomic valences. Therefore, we also present a generalized DBE definition that includes atomic valence to enable calculation of the correct total number of rings, double bonds, and triple bonds for heteroatom-containing compounds.

  16. Metabolic Reactions among Organic Sulfur Compounds

    NASA Technical Reports Server (NTRS)

    Schulte, M.; Rogers, K.

    2005-01-01

    Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.

  17. Computational calculation of equilibrium constants: addition to carbonyl compounds.

    PubMed

    Gómez-Bombarelli, Rafael; González-Pérez, Marina; Pérez-Prior, María Teresa; Calle, Emilio; Casado, Julio

    2009-10-22

    Hydration reactions are relevant for understanding many organic mechanisms. Since the experimental determination of hydration and hemiacetalization equilibrium constants is fairly complex, computational calculations now offer a useful alternative to experimental measurements. In this work, carbonyl hydration and hemiacetalization constants were calculated from the free energy differences between compounds in solution, using absolute and relative approaches. The following conclusions can be drawn: (i) The use of a relative approach in the calculation of hydration and hemiacetalization constants allows compensation of systematic errors in the solvation energies. (ii) On average, the methodology proposed here can predict hydration constants within +/- 0.5 log K(hyd) units for aldehydes. (iii) Hydration constants can be calculated for ketones and carboxylic acid derivatives within less than +/- 1.0 log K(hyd), on average, at the CBS-Q level of theory. (iv) The proposed methodology can predict hemiacetal formation constants accurately at the MP2 6-31++G(d,p) level using a common reference. If group references are used, the results obtained using the much cheaper DFT-B3LYP 6-31++G(d,p) level are almost as accurate. (v) In general, the best results are obtained if a common reference for all compounds is used. The use of group references improves the results at the lower levels of theory, but at higher levels, this becomes unnecessary. PMID:19761202

  18. Computational Calculation of Equilibrium Constants: Addition to Carbonyl Compounds

    NASA Astrophysics Data System (ADS)

    Gómez-Bombarelli, Rafael; González-Pérez, Marina; Pérez-Prior, María Teresa; Calle, Emilio; Casado, Julio

    2009-09-01

    Hydration reactions are relevant for understanding many organic mechanisms. Since the experimental determination of hydration and hemiacetalization equilibrium constants is fairly complex, computational calculations now offer a useful alternative to experimental measurements. In this work, carbonyl hydration and hemiacetalization constants were calculated from the free energy differences between compounds in solution, using absolute and relative approaches. The following conclusions can be drawn: (i) The use of a relative approach in the calculation of hydration and hemiacetalization constants allows compensation of systematic errors in the solvation energies. (ii) On average, the methodology proposed here can predict hydration constants within ± 0.5 log Khyd units for aldehydes. (iii) Hydration constants can be calculated for ketones and carboxylic acid derivatives within less than ± 1.0 log Khyd, on average, at the CBS-Q level of theory. (iv) The proposed methodology can predict hemiacetal formation constants accurately at the MP2 6-31++G(d,p) level using a common reference. If group references are used, the results obtained using the much cheaper DFT-B3LYP 6-31++G(d,p) level are almost as accurate. (v) In general, the best results are obtained if a common reference for all compounds is used. The use of group references improves the results at the lower levels of theory, but at higher levels, this becomes unnecessary.

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

    PubMed

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

    2014-08-01

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

  20. Methods for determination of toxic organic compounds in air

    SciTech Connect

    Winberry, W.T. Jr.

    1990-01-01

    This paper provides environmental regulatory agencies, industry, and other interested parties with specific, standardized sampling and analysis procedures for toxic organic compounds in air. Compounds include Volatile Organic Compounds, Organochlorine Pesticides and PCBs, Aldehydes and Ketones, Phosgene, N-Nitrosodimethylamine, Phenol and Methylphenols (Cresols), Polychlorinated Dibenzo-p-Dioxins (PCDDs), Formaldehyde, Non-Methane Organic Compounds (NMOCs) and Polynuclear Aromatic Hydrocarbons (PAHs).

  1. Volatile organic compound sources for Southern Finland

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Volatile organic compounds (VOCs) have several sources, both biogenic and anthropogenic. Emissions of biogenic VOCs in a global scale are estimated to be an order of magnitude higher than anthropogenic ones. However, in densely populated areas and during winter time the anthropogenic VOC emissions dominate over the biogenic ones. The aim of this study was to clarify potential local sources and source areas of VOCs in different seasons. Diurnal behaviour in winter and spring were also compared at two different sites in Finland: SMEAR II and III (Station for Measuring Ecosystem - Atmosphere Relations). SMEAR II is a rural site located in Hyytiälä in Southern Finland 220 km North-West from Helsinki whereas SMEAR III is background urban site located 5 km from the downtown of Helsinki. The volume mixing ratios of VOCs were measured with a proton-transfer-reaction mass spectrometer (PTR-MS, Ionicon Analytik GmbH, Austria) during years 2006-2011. Other trace gases such as CO, NOXand SO2 were also measured in both sites and used for source analysis. Source areas for long term VOC measurements were investigated with trajectory analysis and sources for local and regional concentrations were determined by Unmix multivariate receptor model. Forest fires affect air quality and the biggest smoke plumes can be seen in satellite images and even hinder visibility in the plume areas. They provide temporally and spatially well-defined sources that can be used to verify source area estimates. During the measurement periods two different forest fire episodes with several hotspots, happened in Russia. Forest fires which showed up in these measurements were in 2006 near the border of Finland in Vyborg area and 2010 in Moscow area. Forest fire episodes were clearly observed in trajectory analysis for benzene, toluene and methanol and also CO and NOX. In addition to event sources continuous source areas were determined. Anthropogenic local sources seemed to be dominant during winter in

  2. The Atmospheric Fate of Organic Nitrogen Compounds

    NASA Astrophysics Data System (ADS)

    Borduas, Nadine

    Organic nitrogen compounds are present in our atmosphere from biogenic and anthropogenic sources and have impacts on air quality and climate. Due to recent advances in instrumentation, these compounds are being detected in the gas and particle phases, raising questions as to their source, processing and sinks in the environment. With their recently identified role as contributors to aerosol formation and growth, their novel large scale use as solvents in carbon capture and storage (CCS) technology and their emissions from cigarette smoke, it is now important to address the gaps in our understanding of the fate of organic nitrogen. Experimentally and theoretically, I studied the chemical atmospheric fate of specific organic nitrogen compounds in the amine, amide and isocyanate families, yielding information that can be used in chemical transport models to assess the fate of this emerging class of atmospheric molecules. I performed kinetic laboratory studies in a smog chamber to measure the room temperature rate coefficient for reaction with the hydroxyl radical of monoethanolamine, nicotine, and five different amides. I employed online-mass spectrometry techniques to quantify the oxidation products. I found that amines react quickly with OH radicals with lifetimes of a few hours under sunlit conditions, producing amides as oxidation products. My studies on amides revealed that they have much longer lifetimes in the atmosphere, ranging from a few hours to a week. Photo-oxidation of amides produces isocyanates and I investigated these mechanisms in detail using ab initio calculations. Furthermore, I experimentally measured isocyanic acid's Henry's Law constant as well as its hydrolysis rate constants to better understand its sinks in the atmosphere. Finally, I re-examined the structure-activity relationship (SAR) of organic nitrogen molecules for improved model parameterizations.

  3. Self assembly properties of primitive organic compounds

    NASA Technical Reports Server (NTRS)

    Deamer, D. W.

    1991-01-01

    A central event in the origin of life was the self-assembly of amphiphilic, lipid-like compounds into closed microenvironments. If a primitive macromolecular replicating system could be encapsulated within a vesicular membrane, the components of the system would share the same microenvironment, and the result would be a step toward true cellular function. The goal of our research has been to determine what amphiphilic molecules might plausibly have been available on the early Earth to participate in the formation of such boundary structures. To this end, we have investigated primitive organic mixtures present in carbonaceous meteorites such as the Murchison meteorite, which contains 1-2 percent of its mass in the form of organic carbon compounds. It is likely that such compounds contributed to the inventory of organic carbon on the prebiotic earth, and were available to participate in chemical evolution leading to the emergence of the first cellular life forms. We found that Murchison components extracted into non-polar solvent systems are surface active, a clear indication of amphiphilic character. One acidic fraction self-assembles into vesicular membranes that provide permeability barriers to polar solutes. Other evidence indicates that the membranes are bimolecular layers similar to those formed by contemporary membrane lipids. We conclude that bilayer membrane formation by primitive amphiphiles on the early Earth is feasible. However, only a minor fraction of acidic amphiphiles assembles into bilayers, and the resulting membranes require narrowly defined conditions of pH and ionic composition to be stable. It seems unlikely, therefore, that meteoritic infall was a direct source of membrane amphiphiles. Instead, the hydrocarbon components and their derivatives more probably would provide an organic stock available for chemical evolution. Our current research is directed at possible reactions which would generate substantial quantities of membranogenic

  4. Microbial cycling of volatile organic sulfur compounds.

    PubMed

    Lomans, B P; van der Drift, C; Pol, A; Op den Camp, H J M

    2002-04-01

    Microbial cycling of volatile organic sulfur compounds (VOSCs), especially dimethyl sulfide (DMS) and methanethiol (MT), is intensively studied because these compounds play an important role in the processes of global warming, acid precipitation, and the global sulfur cycle. VOSC concentrations in freshwater sediments are low due to the balance between the formation and degradation of these compounds. These reactions occur for the greater part at the oxic/anoxic interphase of sediment and water column. In contrast to marine ecosystems, where dimethylsulfoniopropionate is the main precursor of MT and DMS, in freshwater ecosystems, VOSCs are formed mainly by methylation of sulfide and to a lesser extent from the degradation of S-containing amino acids. One of the major routes for DMS and MT formation through sulfide methylation is anaerobic O-demethylation of methoxylated aromatic compounds. Inhibition studies have revealed that the major part of the endogenously produced MT and DMS is degraded anaerobically by methanogens. The major bacterial groups involved in formation and consumption of VOSCs are described. PMID:12022467

  5. Sorption of emerging trace organic compounds onto wastewater sludge solids.

    PubMed

    Stevens-Garmon, John; Drewes, Jörg E; Khan, Stuart J; McDonald, James A; Dickenson, Eric R V

    2011-05-01

    This work examined the sorption potential to wastewater primary- and activated-sludge solids for 34 emerging trace organic chemicals at environmentally relevant concentrations. These compounds represent a diverse range of physical and chemical properties, such as hydrophobicity and charge state, and a diverse range of classes, including steroidal hormones, pharmaceutically-active compounds, personal care products, and household chemicals. Solid-water partitioning coefficients (K(d)) were measured where 19 chemicals did not have previously reported values. Sludge solids were inactivated by a nonchemical lyophilization and dry-heat technique, which provided similar sorption behavior for recalcitrant compounds as compared to fresh activated-sludge. Sorption behavior was similar between primary- and activated-sludge solids from the same plant and between activated-sludge solids from two nitrified processes from different wastewater treatment systems. Positively-charged pharmaceutically-active compounds, amitriptyline, clozapine, verapamil, risperidone, and hydroxyzine, had the highest sorption potential, log K(d)=2.8-3.8 as compared to the neutral and negatively-charged chemicals. Sorption potentials correlated with a compound's hydrophobicity, however the higher sorption potentials observed for positively-charged compounds for a given log D(ow) indicate additional sorption mechanisms, such as electrostatic interactions, are important for these compounds. Previously published soil-based one-parameter models for predicting sorption from hydrophobicity (log K(ow)>2) can be used to predict sorption for emerging nonionic compounds to wastewater sludge solids.

  6. Biogenic volatile organic compounds - small is beautiful

    NASA Astrophysics Data System (ADS)

    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 <2m above ground level. Emissions at leaf scale are well documented and widely presented, and are not discussed here. Instead we describe some details of recent research on rhizosphere bVOCs, and bVOCs associated with pollination of flowers. Although bVOC emissions from soil surfaces are small, bVOCs are exuded by roots of some plant species, and can be extracted from decaying litter. Naturally occurring monoterpenes in the rhizosphere provide a specialised carbon source for micro-organisms, helping to define the micro-organism community structure, and impacting on nutrient cycles which are partly controlled by microorganisms. Naturally occurring monoterpenes in the soil system could also affect the aboveground structure of ecosystems because of their role in plant defence strategies and as mediating chemicals in 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

  7. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect

    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

  8. A method of isolating organic compounds present in water

    NASA Technical Reports Server (NTRS)

    Calder, G. V.; Fritz, J.; Junk, G. A.

    1972-01-01

    Water sample is passed through a column containing macroreticular resin, which absorbs only nonionic organic compounds. These compounds are selectively separated using aqueous eluents of varying pH, or completely exuded with small amount of an organic eluent.

  9. Palladium catalyzed hydrogenation of bio-oils and organic compounds

    DOEpatents

    Elliott, Douglas C.; Hu, Jianli; Hart, Todd R.; Neuenschwander, Gary G.

    2008-09-16

    The invention provides palladium-catalyzed hydrogenations of bio-oils and certain organic compounds. Experimental results have shown unexpected and superior results for palladium-catalyzed hydrogenations of organic compounds typically found in bio-oils.

  10. Palladium catalyzed hydrogenation of bio-oils and organic compounds

    DOEpatents

    Elliott, Douglas C [Kennewick, WA; Hu, Jianli [Richland, WA; Hart,; Todd, R [Kennewick, WA; Neuenschwander, Gary G [Burbank, WA

    2011-06-07

    The invention provides palladium-catalyzed hydrogenations of bio-oils and certain organic compounds. Experimental results have shown unexpected and superior results for palladium-catalyzed hydrogenations of organic compounds typically found in bio-oils.

  11. Volatile Organic Compound Analysis in Istanbul

    NASA Astrophysics Data System (ADS)

    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

  12. Instrument for Analysis of Organic Compounds on Other Planets

    NASA Technical Reports Server (NTRS)

    Daulton, Riley M.; Hintze, Paul E.

    2016-01-01

    The goal of this project is to develop the Instrument for Solvent Extraction and Analysis of Extraterrestrial Bodies using In Situ Resources (ISEE). Specifically, ISEE will extract and characterize organic compounds from regolith which is found on the surface of other planets or asteroids. The techniques this instrument will use are supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC). ISEE aligns with NASA's goal to expand the frontiers of knowledge, capability, and opportunities in space in addition to supporting NASA's aim to search for life elsewhere by characterizing organic compounds. The outcome of this project will be conceptual designs of 2 components of the ISEE instrument as well as the completion of proof-of-concept extraction experiments to demonstrate the capabilities of SFE. The first conceptual design is a pressure vessel to be used for the extraction of the organic compounds from the regolith. This includes a comparison of different materials, geometry's, and a proposition of how to insert the regolith into the vessel. The second conceptual design identifies commercially available fluid pumps based on the requirements needed to generate supercritical CO2. The proof-of-concept extraction results show the percent mass lost during standard solvent extractions of regolith with organic compounds. This data will be compared to SFE results to demonstrate the capabilities of ISEE's approach.

  13. Highly stable meteoritic organic compounds as markers of asteroidal delivery

    NASA Astrophysics Data System (ADS)

    Cooper, George; Horz, Friedrich; Spees, Alanna; Chang, Sherwood

    2014-01-01

    Multiple missions to search for water-soluble organic compounds on the surfaces of Solar System bodies are either current or planned and, if such compounds were found, it would be desirable to determine their origin(s). Asteroid or comet material is likely to have been components of all surface environments throughout Solar System history. To simulate the survival of meteoritic compounds both during impacts with planetary surfaces and under subsequent (possibly) harsh ambient conditions, we subjected known meteoritic compounds to comparatively high impact-shock pressures (>30 GPa) and/or to extremely oxidizing/corrosive acid solution. Consistent with past impact experiments, α-amino acids survived only at trace levels above ∼18 GPa. Polyaromatic hydrocarbons (PAHs) survived at levels of 4-8% at a shock pressure of 36 GPa. Lower molecular weight sulfonic and phosphonic acids (S&P) had the highest degree of impact survival of all tested compounds at higher pressures. Oxidation of compounds was done with a 3:1 mixture of HCl:HNO3, a solution that generates additional strong oxidants such as Cl2 and NOCl. Upon oxidation, keto acids and α-amino acids were the most labile compounds with proline as a significant exception. Some fraction of the other compounds, including non-α amino acids and dicarboxylic acids, were stable during 16-18 hours of oxidation. However, S&P quantitatively survived several months (at least) under the same conditions. Such results begin to build a profile of the more robust meteoritic compounds: those that may have survived, i.e., may be found in, the more hostile Solar System environments. In the search for organic compounds, one current mission, NASA's Mars Science Laboratory (MSL), will use analytical procedures similar to those of this study and those employed previously on Earth to identify many of the compounds described in this work. The current results may thus prove to be directly relevant to potential findings of MSL and other

  14. Bioavailability enhancement by addition of surfactant and surfactant-like compounds

    SciTech Connect

    Strong-Gunderson, J.M.; Palumbo, A.V.

    1995-12-31

    The bioavailability and microbial degradation of contaminant compounds (e.g., toluene and naphthalene) were enhanced by adding synthetic surfactants, biosurfactants, and nutrients with surfactant like properties. In addition to enhanced contaminant degradation, these surfactant compounds have the potential to change the availability of natural organic matter (NOM), and thus may affect overall site bioremediation. Two bacterial bioreporter strains that are induced by toluene or naphthalene were used to directly measure contaminant bioavailability. A cell-free biosurfactant product, Tween-80, and an oleophilic fertilizer were added to aqueous suspensions and soil slurries containing toluene or naphthalene. The addition of these surfactant compounds at or below the critical micelle concentration (CMC) enhanced bioavailability as measured by increased levels of bioluminescence. Bioluminescence data were coupled with gas chromatographic analyses. The addition of Tween-80 increased not only the bioavailability of the contaminants but also, in a separate assay, the bioavailability of recalcitrant NOM. The enhanced NOM bioavailability was inferred from measurements of biomass by optical density increases and plate counts. Thus, adding surfactant compounds for enhanced contaminant degradation has the potential to introduce additional competition for nutrients and microbial metabolism, a significant area of concern for in situ site remediation.

  15. IRRADIATION METHOD OF CONVERTING ORGANIC COMPOUNDS

    DOEpatents

    Allen, A.O.; Caffrey, J.M. Jr.

    1960-10-11

    A method is given for changing the distribution of organic compounds from that produced by the irradiation of bulk alkane hydrocarbons. This method consists of depositing an alkane hydrocarbon on the surface of a substrate material and irradiating with gamma radiation at a dose rate of more than 100,000 rads. The substrate material may be a metal, metal salts, metal oxides, or carbons having a surface area in excess of 1 m/sup 2//g. The hydrocarbons are deposited in layers of from 0.1 to 10 monolayers on the surfaces of these substrates and irradiated. The product yields are found to vary from those which result from the irradiation of bulk hydrocarbons in that there is an increase in the quantity of branched hydrocarbons.

  16. Computational assessment of organic photovoltaic candidate compounds

    NASA Astrophysics Data System (ADS)

    Borunda, Mario; Dai, Shuo; Olivares-Amaya, Roberto; Amador-Bedolla, Carlos; Aspuru-Guzik, Alan

    2015-03-01

    Organic photovoltaic (OPV) cells are emerging as a possible renewable alternative to petroleum based resources and are needed to meet our growing demand for energy. Although not as efficient as silicon based cells, OPV cells have as an advantage that their manufacturing cost is potentially lower. The Harvard Clean Energy Project, using a cheminformatic approach of pattern recognition and machine learning strategies, has ranked a molecular library of more than 2.6 million candidate compounds based on their performance as possible OPV materials. Here, we present a ranking of the top 1000 molecules for use as photovoltaic materials based on their optical absorption properties obtained via time-dependent density functional theory. This computational search has revealed the molecular motifs shared by the set of most promising molecules.

  17. Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group-Update and Additions to the Determination of Chloroacetanilide Herbicide Degradation Compounds in Water Using High-Performance Liquid Chromatography/Mass Spectrometry

    USGS Publications Warehouse

    Lee, E.A.; Kish, J.L.; Zimmerman, L.R.; Thurman, E.

    2001-01-01

    An analytical method using high-performance liquid chromatography/mass spectrometry (HPLC/MS) was developed by the U.S. Geological Survey in 1999 for the analysis of selected chloroacetanilide herbicide degradation compounds in water. These compounds were acetochlor ethane sulfonic acid (ESA), acetochlor oxanilic acid (OXA), alachlor ESA, alachlor OXA, metolachlor ESA, and metolachlor OXA. The HPLC/MS method was updated in 2000, and the method detection limits were modified accordingly. Four other degradation compounds also were added to the list of compounds that can be analyzed using HPLC/MS; these compounds were dimethenamid ESA, dimethenamid OXA, flufenacet ESA, and flufenacet OXA. Except for flufenacet OXA, good precision and accuracy were demonstrated for the updated HPLC/MS method in buffered reagent water, surface water, and ground water. The mean HPLC/MS recoveries of the degradation compounds from water samples spiked at 0.20 and 1.0 ?g/L (microgram per liter) ranged from 75 to 114 percent, with relative standard deviations of 15.8 percent or less for all compounds except flufenacet OXA, which had relative standard deviations ranging from 11.3 to 48.9 percent. Method detection levels (MDL's) using the updated HPLC/MS method varied from 0.009 to 0.045 ?g/L, with the flufenacet OXA MDL at 0.072 ?g/L. The updated HPLC/MS method is valuable for acquiring information about the fate and transport of the parent chloroacetanilide herbicides in water.

  18. Organic compounds in meteorites and their origins

    NASA Technical Reports Server (NTRS)

    Hayatsu, R.; Anders, E.

    1981-01-01

    The current investigation represents an extensively updated version of a review conducted by Anders et al. (1973). The investigation takes into account the literature through mid-1980. It is pointed out that Type 1 carbonaceous chondrites (C1) contain 6% of their cosmic complement of carbon, mainly in the form of organic matter. Most authors now agree that this material represents primitive prebiotic matter. The principal questions remaining are what abiotic processes formed the organic matter, and to what extent these processes took place in locales other than the solar nebula, such as interstellar clouds or meteorite parent bodes. The problem is approached in three stages. It is attempted to reconstruct the physical conditions during condensation from the clues contained in the inorganic matrix of the meteorite. The condensation behavior of carbon under these conditions is determined on the basis of thermodynamic calculations. Model experiments on the condensation of carbon are performed, and the synthesized compounds are compared with those actually found in meteorites.

  19. Natural organic compounds as tracers for biomass combustion in aerosols

    SciTech Connect

    Simoneit, B.R.T. |; Abas, M.R. bin |; Cass, G.R. |; Rogge, W.F. |; Mazurek, M.A.; Standley, L.J.; Hildemann, L.M.

    1995-08-01

    Biomass combustion is an important primary source of carbonaceous particles in the global atmosphere. Although various molecular markers have already been proposed for this process, additional specific organic tracers need to be characterized. The injection of natural product organic tracers to smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. The degree of alteration increases as the burn temperature rises and the moisture content of the fuel decreases. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular structures of the tracers are generally source specific. The homologous compound series and biomarkers present in smoke particles are derived directly from plant wax, gum and resin by volatilization and secondarily from pyrolysis of biopolymers, wax, gum and resin. The complexity of the organic components of smoke aerosol is illustrated with examples from controlled burns of temperate and tropical biomass fuels. Burning of biomass from temperate regions (i.e., conifers) yields characteristic tracers from diterpenoids as well as phenolics and other oxygenated species, which are recognizable in urban airsheds. The major organic components of smoke particles from tropical biomass are straight-chain, aliphatic and oxygenated compounds and triterpenoids. The precursor-to-product approach of organic geochemistry can be applied successfully to provide tracers for studying smoke plume chemistry and dispersion.

  20. Tritium labeling of organic compounds deposited on porous structures

    DOEpatents

    Ehrenkaufer, Richard L. E.; Wolf, Alfred P.; Hembree, Wylie C.

    1979-01-01

    An improved process for labeling organic compounds with tritium is carried out by depositing the selected compound on the extensive surface of a porous structure such as a membrane filter and exposing the membrane containing the compound to tritium gas activated by the microwave discharge technique. The labeled compound is then recovered from the porous structure.

  1. Breath measurements as volatile organic compound biomarkers.

    PubMed Central

    Wallace, L; Buckley, T; Pellizzari, E; Gordon, S

    1996-01-01

    A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water. PMID:8933027

  2. Volatile Organic Compound Emissions by Agricultural Crops

    NASA Astrophysics Data System (ADS)

    Ormeno, E.; Farres, S.; Gentner, D.; Park, J.; McKay, M.; Karlik, J.; Goldstein, A.

    2008-12-01

    Biogenic Volatile Organic Compounds (BVOCs) participate in ozone and aerosol formation, and comprise a substantial fraction of reactive VOC emission inventories. In the agriculturally intensive Central Valley of California, emissions from crops may substantially influence regional air quality, but emission potentials have not been extensively studied with advanced instrumentation for many important crops. Because crop emissions may vary according to the species, and California emission inventories are constructed via a bottom-up approach, a better knowledge of the emission rate at the species-specific level is critical for reducing uncertainties in emission inventories and evaluating emission model performance. In the present study we identified and quantified the BVOCs released by dominant agricultural crops in California. A screening study to investigate both volatile and semivolatile BVOC fractions (oxygenated VOCs, isoprene, monoterepenes, sesquiterpenes, etc.) was performed for 25 crop species (at least 3 replicates plants each), including branch enclosures of woody species (e.g. peach, mandarin, grape, pistachio) and whole plant enclosures for herbaceous species (e.g. onion, alfalfa, carrot), through a dynamic cuvette system with detection by PTRMS, in-situ GCMS/FID, and collection on carbon-based adsorbents followed by extraction and GCMS analysis. Emission data obtained in this study will allow inclusion of these crops in BVOC emission inventories and air quality simulations.

  3. Volatile organic compound remedial action project

    SciTech Connect

    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).

  4. Organic compounds in concrete from demolition works.

    PubMed

    Van Praagh, M; Modin, H; Trygg, J

    2015-11-01

    This study aims to verify the effect of physically removing the outer surface of contaminated concrete on total contents and on potential mobility of pollutants by means of leaching tests. Reclaimed concrete from 3 industrial sites in Sweden were included: A tar impregnated military storage, a military tar track-depot, as well as concrete constructions used for disposing of pesticide production surplus and residues. Solid materials and leachates from batch and column leaching tests were analysed for metals, Cl, F, SO4, DOC and contents of suspected organic compounds (polycyclic aromatic hydrocarbons, PAH, and pesticides/substances for pesticide production such as phenoxy acids, chlorophenols and chlorocresols, respectively). In case of PAH contaminated concrete, results indicate that removing 1 or 5 mm of the surface lead to total concentrations below the Swedish guidelines for recycling of aggregates and soil in groundwork constructions. 3 out of 4 concrete samples contaminated with pesticides fulfilled Swedish guidelines for contaminated soil. Results from batch and column leaching tests indicated, however, that concentrations above environmental quality standards for certain PAH and phenoxy acids, respectively, might occur at site when the crushed concrete is recycled in groundwork constructions. As leaching tests engaged in the study deviated from leaching test standards with a limited number of samples, the potential impact of the leaching tests' equipment on measured PAH and pesticide leachate concentrations has to be evaluated in future work. PMID:26164853

  5. Organic compounds in concrete from demolition works.

    PubMed

    Van Praagh, M; Modin, H; Trygg, J

    2015-11-01

    This study aims to verify the effect of physically removing the outer surface of contaminated concrete on total contents and on potential mobility of pollutants by means of leaching tests. Reclaimed concrete from 3 industrial sites in Sweden were included: A tar impregnated military storage, a military tar track-depot, as well as concrete constructions used for disposing of pesticide production surplus and residues. Solid materials and leachates from batch and column leaching tests were analysed for metals, Cl, F, SO4, DOC and contents of suspected organic compounds (polycyclic aromatic hydrocarbons, PAH, and pesticides/substances for pesticide production such as phenoxy acids, chlorophenols and chlorocresols, respectively). In case of PAH contaminated concrete, results indicate that removing 1 or 5 mm of the surface lead to total concentrations below the Swedish guidelines for recycling of aggregates and soil in groundwork constructions. 3 out of 4 concrete samples contaminated with pesticides fulfilled Swedish guidelines for contaminated soil. Results from batch and column leaching tests indicated, however, that concentrations above environmental quality standards for certain PAH and phenoxy acids, respectively, might occur at site when the crushed concrete is recycled in groundwork constructions. As leaching tests engaged in the study deviated from leaching test standards with a limited number of samples, the potential impact of the leaching tests' equipment on measured PAH and pesticide leachate concentrations has to be evaluated in future work.

  6. Volatile Organic Compounds Contribute to Airway Hyperresponsiveness

    PubMed Central

    Jang, An-Soo; Choi, Inseon-S; Koh, Young-Il

    2007-01-01

    Background Volatile organic compounds (VOCs) in concentrations found in both the work and home environments may influence lung function. We investigated the prevalence of airway responsiveness in workers exposed to VOCs. Methods We used allergic skin tests, nonspecific airway hyperresponsiveness testing and questionnaires to study twenty exposed workers and twenty-seven control subjects. Atopy was defined as a reactor who showed >3+ response to one or more allergens on the skin prick tests. Airway hyperresponsiveness (BRindex) was defined as log [% fall of FEV1/ log (last concentration of methacholine) +10]. Results The VOC exposed workers, in comparison with the control subjects, tended to have a higher BRindex (1.19±0.07 vs. 1.15±0.08, respectively). Workers exposed to VOCs with atopy or smoker, as compared with the workers exposed to VOCs with non-atopy and who were non-smokers and the control subjects with non-atopy and who were non-smokers, had a significantly higher BRindex (1.20±0.05 vs. 1.14±0.06 vs. 1.10±0.03, respectively p<0.05). The BRindex was not correlated with atopy, the smoking status or the duration of VOC exposure. Conclusions These findings suggest that VOCs may act as a contributing factor of airway hyperresponsiveness in workers exposed to VOCs. PMID:17427638

  7. Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

    NASA Astrophysics Data System (ADS)

    Yang, M.; Blomquist, B.; Beale, R.; Nightingale, P. D.; Liss, P. S.

    2015-12-01

    Atmospheric volatile organic compounds (VOCs) affect the tropospheric oxidative capacity due to their ubiquitous abundance and relatively high reactivity towards the hydroxyal radical. Over the ocean and away from terrestrial emission sources, oxygenated volatile organic compounds (OVOCs) make up a large fraction of VOCs as airmasses age and become more oxidized. In addition to being produced or destroyed in the marine atmosphere, OVOCs can also be emitted from or deposited to the surface ocean. Here we first present direct air-sea flux measurements of three of the most abundant OVOCs - methanol, acetone, and acetaldehyde, by the eddy covariance technique from two cruises in the Atlantic: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The OVOC mixing ratios were quantified by a high resolution proton-reaction-transfer mass spectrometer with isotopically labeled standards and their air-sea (net) fluxes were derived from the eddy covariance technique. Net methanol flux was consistently from the atmosphere to the surface ocean, while acetone varied from supersaturation (emission) in the subtropics to undersaturation (deposition) in the higher latitudes of the North Atlantic. The net air-sea flux of acetaldehyde is near zero through out the Atlantic despite the apparent supersaturation of this compound in the surface ocean. Knowing the dissolved concentrations and in situ production rates of these compounds in seawater, we then estimate their bulk atmospheric depositions and oceanic emissions. Lastly, we summarize the state of knowledge on the air-sea transport of a number of organic gasses, and postulate the magnitude and environmental impact of total organic carbon transfer between the ocean and the atmosphere.

  8. Method and reaction pathway for selectively oxidizing organic compounds

    DOEpatents

    Camaioni, Donald M.; Lilga, Michael A.

    1998-01-01

    A method of selectively oxidizing an organic compound in a single vessel comprises: a) combining an organic compound, an acid solution in which the organic compound is soluble, a compound containing two oxygen atoms bonded to one another, and a metal ion reducing agent capable of reducing one of such oxygen atoms, and thereby forming a mixture; b) reducing the compound containing the two oxygen atoms by reducing one of such oxygen atoms with the metal ion reducing agent to, 1) oxidize the metal ion reducing agent to a higher valence state, and 2) produce an oxygen containing intermediate capable of oxidizing the organic compound; c) reacting the oxygen containing intermediate with the organic compound to oxidize the organic compound into an oxidized organic intermediate, the oxidized organic intermediate having an oxidized carbon atom; d) reacting the oxidized organic intermediate with the acid counter ion and higher valence state metal ion to bond the acid counter ion to the oxidized carbon atom and thereby produce a quantity of an ester incorporating the organic intermediate and acid counter ion; and e) reacting the oxidized organic intermediate with the higher valence state metal ion and water to produce a quantity of alcohol which is less than the quantity of ester, the acid counter ion incorporated in the ester rendering the carbon atom bonded to the counter ion less reactive with the oxygen containing intermediate in the mixture than is the alcohol with the oxygen containing intermediate.

  9. Nitrated Secondary Organic Tracer Compounds in Biomass Burning Smoke

    NASA Astrophysics Data System (ADS)

    Iinuma, Y.; Böge, O.; Gräfe, R.; Herrmann, H.

    2010-12-01

    Natural and human-initiated biomass burning releases large amounts of gases and particles into the atmosphere, impacting climate, environment and affecting public health. Several hundreds of compounds are emitted from biomass burning and these compounds largely originate from the pyrolysis of biopolymers such as lignin, cellulose and hemicellulose. Some of compounds are known to be specific to biomass burning and widely recognized as tracer compounds that can be used to identify the presence of biomass burning PM. Detailed chemical analysis of biomass burning influenced PM samples often reveals the presence compounds that correlated well with levoglucosan, a known biomass burning tracer compound. In particular, nitrated aromatic compounds correlated very well with levoglucosan, indicating that biomass burning as a source for this class of compounds. In the present study, we present evidence for the presence of biomass burning originating secondary organic aerosol (BSOA) compounds in biomass burning influenced ambient PM. These BSOA compounds are typically nitrated aromatic compounds that are produced in the oxidation of precursor compounds in the presence of NOx. The precursor identification was performed from a series of aerosol chamber experiments. m-Cresol, which is emitted from biomass burning at significant levels, is found to be a major precursor compounds for nitrated BSOA compounds found in the ambient PM. We estimate that the total concentrations of these compounds in the ambient PM are comparable to biogenic SOA compounds in winter months, indicating the BSOA contributes important amounts to the regional organic aerosol loading.

  10. Development of a new semi-volatile organic compound sampler

    SciTech Connect

    Sioutas, C.; Koutrakis, P.; Burton, R.M.

    1994-12-31

    A new sampler has been developed to sample semi-volatile organic compounds. The sampler utilizes the principle of virtual impactor to efficiently separate the particulate from the gas phases of organic compounds. The virtual impactor consists of a slit-shaped nozzle where the aerosol is accelerated, and another slit-shaped nozzle that collects the particulate phase of organics (plus a small and known fraction of the gas phase). The acceleration slit is 0.023 cm wide, the collection slit is 0.035 cm wide, and both slits are 11 cm long. The virtual impactor`s 50% cutpoint has been determined experimentally to be 0.12 {micro}m. In addition, interstage losses have been determined (in all configurations tested, particle losses ranged from 5--15%). The impactor`s sampling flow rate is 284 liters/minute, with a corresponding pressure drop of 100 inches H{sub 2}O. Higher or lower sampling flow rates can be achieved by increasing or decreasing the length of the slits. Tests for volatilization losses have been conducted by generating organic aerosols of known volatility, and comparing the impactor`s collection to that of a filter pack sampling in parallel. The experiments demonstrated negligible volatilization losses (< 5%) for the compounds tried. Particles are collected on a filter connected to the minor flow of the impactor, followed by a sorbent bed to collect material that volatilized from the particles. The organic gas phases is collected on a sorbent bed, connected to the major flow of the impactor.

  11. Characteristics of the volatile organic compounds -- Arid Integrated Demonstration Site

    SciTech Connect

    Last, G.V.; Lenhard, R.J.; Bjornstad, B.N.; Evans, J.C.; Roberson, K.R.; Spane, F.A.; Amonette, J.E.; Rockhold, M.L.

    1991-10-01

    The Volatile Organic Compounds -- Arid Integrated Demonstration Program (VOC-Arid ID) is targeted at demonstration and testing of technologies for the evaluation and cleanup of volatile organic compounds and associated contaminants at arid DOE sites. The initial demonstration site is an area of carbon tetrachloride (CCl{sub 4}) contamination located near the center of the Hanford Site. The movement of CCl{sub 4} and other volatile organic contaminants in the subsurface is very complex. The problem at the Hanford Site is further complicated by the concurrent discharge of other waste constituents including acids, lard oil, organic phosphates, and transuranic radionuclides. In addition, the subsurface environment is very complex, with large spatial variabilities in hydraulic properties. A thorough understanding of the problem is essential to the selection of appropriate containment, retrieval, and/or in situ remedial technologies. The effectiveness of remedial technologies depends on knowing where the contaminants are, how they are held up in a given physical and chemical subsurface environment; and knowing the physical, chemical, and microbiological changes that are induced by the various remedial technologies.

  12. Simulation of Comet Impact and Survivability of Organic Compounds

    SciTech Connect

    Liu, B T; Lomov, I N; Blank, J G; Antoun, T H

    2007-07-18

    Comets have long been proposed as a potential means for the transport of complex organic compounds to early Earth. For this to be a viable mechanism, a significant fraction of organic compounds must survive the high temperatures due to impact. We have undertaken three-dimensional numerical simulations to track the thermodynamic state of a comet during oblique impacts. The comet was modeled as a 1-km water-ice sphere impacting a basalt plane at 11.2 km/s; impact angles of 15{sup o} (from horizontal), 30{sup o}, 45{sup o}, 65{sup o}, and 90{sup o} (normal impact) were examined. The survival of organic cometary material, modeled as water ice for simplicity, was calculated using three criteria: (1) peak temperatures, (2) the thermodynamic phase of H{sub 2}O, and (3) final temperature upon isentropic unloading. For impact angles greater than or equal to 30{sup o}, no organic material is expected to survive the impact. For the 15{sup o} impact, most of the material survives the initial impact and significant fractions (55%, 25%, and 44%, respectively) satisfy each survival criterion at 1 second. Heating due to deceleration, in addition to shock heating, plays a role in the heating of the cometary material for nonnormal impacts. This effect is more noticeable for more oblique impacts, resulting in significant deviations from estimates using scaling of normal impacts. The deceleration heating of the material at late times requires further modeling of breakup and mixing.

  13. Challenges and solutions for biofiltration of hydrophobic volatile organic compounds.

    PubMed

    Cheng, Yan; He, Huijun; Yang, Chunping; Zeng, Guangming; Li, Xiang; Chen, Hong; Yu, Guanlong

    2016-11-01

    Volatile organic compounds (VOCs) emitted to the environment highly probably result in ecological and health risks. Many biotechnologies for waste gases containing hydrophobic VOCs have been developed in recent years. However, these biological processes usually exhibit poor removal performances for hydrophobic VOCs due to the low bioavailability. This review presents an overview of enhanced removal of hydrophobic VOCs in biofilters. Mechanisms and problems relevant to the biological removal of hydrophobic VOCs are reviewed, and then solutions including the addition of surfactants, application of fungal biocatalysts, biofiltration with pretreatment, innovative bioreactors and utilization of hydrophilic compounds are discussed in detail. Future research needs are also proposed. This review provides new insights into hydrophobic VOC removal by biofiltration. PMID:27374790

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

    USGS Publications Warehouse

    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.

  15. Zeolite-catalyzed additions of aromatic compounds to oleic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is significant research interest in developing new materials from vegetable oils and animal fats. Biobased materials can be more environmentally friendly because they tend to have good biodegradability and are derived from renewable resources. In this talk, efficient approaches for the addit...

  16. Kinetic study of additions of dialkylmagnesium compounds to a cycloprene

    SciTech Connect

    Watkins, E.K.; Richey, H.G. Jr.

    1992-11-01

    Reaction of Et{sub 2}Mg and spiro[2.4]hept-1-ene (1) in tetahydrofuran followed by hydrolysis furnishes mainly 1-ethylspiro[2.4]heptane (3); when hydrolysis is with D{sub 2}O, {ge}98% of this (Z)-1-ethylspirol[2.4]heptane-2-d (4). Some metalation of 1 and formation of higher molecular weight products incorporating two or three molecules of 1 also take place. Formation of 3 is first order in 1 and in Et{sub 2}Mg, and at 35.47{degrees}C the rate constant is 1.2 x 10{sup -5} L M{sup -1}s{sup -1}. Under the same conditions, the rate of addition (1.5 x 10{sup -5} L M{sup -1}{sub s}{sup -1}). Under the same conditions, the rate of addition (1.5 x 10{sup -5} L mol{sup -1} {sub s}{sup -1}) of the Grignard reagent prepared from EtBr is similar. Reactions of 1 with Me{sub 2}Mg, I-Pr{sub 2}Mg, and t-Bu{sub 2}Mg. Added Fe(acac){sub 3} increases the rate of formation of 3 from reactions of 1 with either Et{sub 2}Mg or the Grignard reagent prepared from EtBr, but additional products also are formed. 55 refs., 2 tabs.

  17. Potentially useful polyolester lubricant additives an overview of antioxidants, antiwear and antiseize compounds

    SciTech Connect

    Cavestri, R.C.

    1996-11-01

    Reliable service lubrication of compressors with polyolesters that do not contain additives is the optimal goal for hermetic compressor use. Chlorine derived from CFC and HCFC refrigerants is reported to have effective antiwear properties and negates the widespread use of additives in mineral oil lubricated systems. The use of antioxidants for mineral oil and polyolesters have been reported; antioxidant additive activity seems essential for polyolesters.- Antiwear and antiseize additives seem to be a short term goal for use with polyolesters. High silicone aluminum to steel wear seems to be a primary target for additive use. The interaction of specific heteroatom organic compounds with highly polar surface active synthetic polyolester lubricants is complex. Results of an extensive literature search describe results from a service base determined at ambient conditions. Known lubricant additives used in the hermetic compressor industry, the. mode of action of several types of additives and some lubricant additive chemistry that demonstrates selective thermal stability in conjunction with the chemical structure are examined.

  18. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 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...

  19. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  20. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 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)...

  1. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  2. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  3. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 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...

  4. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  5. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  6. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 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...

  7. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 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...

  8. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 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...

  9. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  10. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 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)...

  11. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  12. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  13. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 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...

  14. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  15. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 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)...

  16. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  17. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  18. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  19. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 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...

  20. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  1. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  2. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  3. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 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...

  4. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  5. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  6. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  7. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  8. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  9. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    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)...

  10. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  11. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    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...

  12. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  13. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  14. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  15. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  16. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    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...

  17. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  18. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  19. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  20. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  1. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 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)...

  2. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  3. A Systematic Presentation of Organic Phosphorus and Sulfur Compounds.

    ERIC Educational Resources Information Center

    Hendrickson, James B.

    1985-01-01

    Because the names, interrelations, and oxidation levels of the organic compounds of phosphorus and sulfur tend to confuse students, a simple way to organize these compounds has been developed. The system consists of grouping them by oxidation state and extent of carbon substitution. (JN)

  4. Multifunctional additives for automotive gasolines based on oxyethylated compounds

    SciTech Connect

    Lykov, O.P.; Vishnyakova, T.P.; Tsygan, L.V.; Emel'yanov, V.E.

    1987-03-01

    The authors have investigated various oil-soluble nonionic surfactants with different degrees of oxyethylation as multifunctional additives for gasolines. The following products were taken for oxyethylation: C/sub 17/-C/sub 20/ synthetic fatty acids; concentrate of isocarboxylic and unsaturated acids segregated from C/sub 17/-C/sub 20/ SFA by cold acetone; technical C/sub 10/-C/sub 18/ alkylsalicylic acids; products from the condensation of AC acids with C/sub 10/-C/sub 16/ aliphatic amines; primary aliphatic amines.

  5. Global simulation of aromatic volatile organic compounds in the atmosphere

    NASA Astrophysics Data System (ADS)

    Cabrera Perez, David; Taraborrelli, Domenico; Pozzer, Andrea

    2015-04-01

    Among the large number of chemical compounds in the atmosphere, the organic group plays a key role in the tropospheric chemistry. Specifically the subgroup called aromatics is of great interest. Aromatics are the predominant trace gases in urban areas due to high emissions, primarily by vehicle exhausts and fuel evaporation. They are also present in areas where biofuel is used (i.e residential wood burning). Emissions of aromatic compounds are a substantial fraction of the total emissions of the volatile organic compounds (VOC). Impact of aromatics on human health is very important, as they do not only contribute to the ozone formation in the urban environment, but they are also highly toxic themselves, especially in the case of benzene which is able to trigger a range of illness under long exposure, and of nitro-phenols which cause detrimental for humans and vegetation even at very low concentrations. The aim of this work is to assess the atmospheric impacts of aromatic compounds on the global scale. The main goals are: lifetime and budget estimation, mixing ratios distribution, net effect on ozone production and OH loss for the most emitted aromatic compounds (benzene, toluene, xylenes, ethylbenzene, styrene and trimethylbenzenes). For this purpose, we use the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model to build the global atmospheric budget for the most emitted and predominant aromatic compounds in the atmosphere. A set of emissions was prepared in order to include biomass burning, vegetation and anthropogenic sources of aromatics into the model. A chemical mechanism based on the Master Chemical Mechanism (MCM) was developed to describe the chemical oxidation in the gas phase of these aromatic compounds. MCM have been reduced in terms of number of chemical equation and species in order to make it affordable in a 3D model. Additionally other features have been added, for instance the production of HONO via ortho

  6. Remotion of organic compounds of actual industrial effluents by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Sampa, M. H. O.; Duarte, C. L.; Rela, P. R.; Somessari, E. S. R.; Silveira, C. G.; Azevedo, A. L.

    1998-06-01

    Organic compounds has been a great problem of environmental pollution, the traditional methods are not effecient on removing these compounds and most of them are deposited to ambient and stay there for long time causing problems to the environment. Ionizing radiation has been used with success to destroy organic molecules. Actual industrial effluents were irradiated using IPEN's electron beam wastewater pilot plant to study organic compounds degradation. The samples were irradiated with and without air mixture by different doses. Irradiation treatment efficiency was evaluated by the Cromatography Gas Analyses of the samples before and after irradiation. The studied organic compounds were: phenol, chloroform, tetrachloroethylene (PCE), carbon tetrachloride, trichloroethylene (TCE), 1,1-dichloroethane, dichloromethane, benzene, toluene and xilene. A degradation superior to 80% was achieved for the majority of the compounds with air addition and 2kGy delivered dose condition. For the samples that were irradiated without air addition the degradation was higher.

  7. Thermodynamics of Aqueous Organic Sulfur Compounds: A Key to the Organic Geochemistry of Hydrothermal Systems?

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Rogers, Karyn L.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Hydrothermal environments are locations of varied geochemistry due to the disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Observations of the organic geochemistry of hydrothermal vent sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols. thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in hydrothermal environments as well as in a variety of biological processes and other abiotic reactions (Wachtershauser, 1990, OLEB 20, 173; Heinen and Lauwers, 1996, OLEB 26, 13 1, Huber and Wachtershauser, 1997, Science 276, 245; Russell et al., 1998, in Thermophiles: The keys to molecular evolution and the origin of life?). The reduction of CO2 to thiols, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power (see Schoonen et al., 1999, OLEB 29, 5). In addition, the enzyme involved in final stage of methanogenesis, coenzyme-M, is itself a thiol. Thus, organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life at high temperatures. Understanding the biochemical processes of microorganisms that can live to temperatures at least as high as 113 C (Blochl et al., 1996, Extremophiles 1, 14) requires knowledge of the properties of the chemical reactions involved. In order to assess the role of aqueous organic sulfur compounds in hydrothermal organic geochemistry, we have been attempting to determine their thermodynamic properties. We have culled the literature to obtain the properties of organic sulfur compounds. We are able to calculate a number of essential properties, such as free energies of formation, from solubility data available in the literature together with standard

  8. Quantifying commuter exposures to volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  9. Quantifying commuter exposures to volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  10. Organic Compounds in Circumstellar and Interstellar Environments

    NASA Astrophysics Data System (ADS)

    Kwok, Sun

    2015-06-01

    Recent research has discovered that complex organic matter is prevalent throughout the Universe. In the Solar System, it is found in meteorites, comets, interplanetary dust particles, and planetary satellites. Spectroscopic signatures of organics with aromatic/aliphatic structures are also found in stellar ejecta, diffuse interstellar medium, and external galaxies. From space infrared spectroscopic observations, we have found that complex organics can be synthesized in the late stages of stellar evolution. Shortly after the nuclear synthesis of the element carbon, organic gas-phase molecules are formed in the stellar winds, which later condense into solid organic particles. This organic synthesis occurs over very short time scales of about a thousand years. In order to determine the chemical structures of these stellar organics, comparisons are made with particles produced in the laboratory. Using the technique of chemical vapor deposition, artificial organic particles have been created by injecting energy into gas-phase hydrocarbon molecules. These comparisons led us to believe that the stellar organics are best described as amorphous carbonaceous nanoparticles with mixed aromatic and aliphatic components. The chemical structures of the stellar organics show strong similarity to the insoluble organic matter found in meteorites. Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in old stars. This provides a direct link between star dust and the Solar System and raises the possibility that the early Solar System was chemically enriched by stellar ejecta with the potential of influencing the origin of life on Earth.

  11. Organic compounds in circumstellar and interstellar environments.

    PubMed

    Kwok, Sun

    2015-06-01

    Recent research has discovered that complex organic matter is prevalent throughout the Universe. In the Solar System, it is found in meteorites, comets, interplanetary dust particles, and planetary satellites. Spectroscopic signatures of organics with aromatic/aliphatic structures are also found in stellar ejecta, diffuse interstellar medium, and external galaxies. From space infrared spectroscopic observations, we have found that complex organics can be synthesized in the late stages of stellar evolution. Shortly after the nuclear synthesis of the element carbon, organic gas-phase molecules are formed in the stellar winds, which later condense into solid organic particles. This organic synthesis occurs over very short time scales of about a thousand years. In order to determine the chemical structures of these stellar organics, comparisons are made with particles produced in the laboratory. Using the technique of chemical vapor deposition, artificial organic particles have been created by injecting energy into gas-phase hydrocarbon molecules. These comparisons led us to believe that the stellar organics are best described as amorphous carbonaceous nanoparticles with mixed aromatic and aliphatic components. The chemical structures of the stellar organics show strong similarity to the insoluble organic matter found in meteorites. Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in old stars. This provides a direct link between star dust and the Solar System and raises the possibility that the early Solar System was chemically enriched by stellar ejecta with the potential of influencing the origin of life on Earth. PMID:25720971

  12. Organic compounds in circumstellar and interstellar environments.

    PubMed

    Kwok, Sun

    2015-06-01

    Recent research has discovered that complex organic matter is prevalent throughout the Universe. In the Solar System, it is found in meteorites, comets, interplanetary dust particles, and planetary satellites. Spectroscopic signatures of organics with aromatic/aliphatic structures are also found in stellar ejecta, diffuse interstellar medium, and external galaxies. From space infrared spectroscopic observations, we have found that complex organics can be synthesized in the late stages of stellar evolution. Shortly after the nuclear synthesis of the element carbon, organic gas-phase molecules are formed in the stellar winds, which later condense into solid organic particles. This organic synthesis occurs over very short time scales of about a thousand years. In order to determine the chemical structures of these stellar organics, comparisons are made with particles produced in the laboratory. Using the technique of chemical vapor deposition, artificial organic particles have been created by injecting energy into gas-phase hydrocarbon molecules. These comparisons led us to believe that the stellar organics are best described as amorphous carbonaceous nanoparticles with mixed aromatic and aliphatic components. The chemical structures of the stellar organics show strong similarity to the insoluble organic matter found in meteorites. Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in old stars. This provides a direct link between star dust and the Solar System and raises the possibility that the early Solar System was chemically enriched by stellar ejecta with the potential of influencing the origin of life on Earth.

  13. Phosphatase hydrolysis of organic phosphorus compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphatases are diverse groups of enzymes that deserve special attention because of the significant roles they play in mineralizing organic phosphorus (P) into inorganic available form. For getting more insight on the enzymatically hydrolysis of organic P, in this work, we compared the catalytic pa...

  14. Modeling Emissions of Volatile Organic Compounds from New Carpets

    SciTech Connect

    Little, J.C.; Hodgson, A.T.; Gadgil, A.J.

    1993-02-01

    A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the polymer/air partition coefficients generally increase as the vapor pressure of the compounds decrease. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that predictions of VOCs emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.

  15. Eco-friendly polyethylene glycol promoted Michael addition reactions of α,β-unsaturated carbonyl compounds

    EPA Science Inventory

    Abstract- Intra- and inter-nucleophilic addition reactions of different unsaturated compounds were found to be highly effective without any additives in PEG-400 as a recyclable reaction medium under neutral conditions.

  16. Organic compounds in produced waters from shale gas wells.

    PubMed

    Maguire-Boyle, Samuel J; Barron, Andrew R

    2014-01-01

    A detailed analysis is reported of the organic composition of produced water samples from typical shale gas wells in the Marcellus (PA), Eagle Ford (TX), and Barnett (NM) formations. The quality of shale gas produced (and frac flowback) waters is a current environmental concern and disposal problem for producers. Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment. The metal content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Mineral elements are expected depending on the reservoir geology and salts used in hydraulic fracturing; however, significant levels of other transition metals and heavier main group elements are observed. The presence of scaling elements (Ca and Ba) is related to the pH of the water rather than total dissolved solids (TDS). Using gas chromatography mass spectrometry (GC/MS) analysis of the chloroform extracts of the produced water samples, a plethora of organic compounds were identified. In each water sample, the majority of organics are saturated (aliphatic), and only a small fraction comes under aromatic, resin, and asphaltene categories. Unlike coalbed methane produced water it appears that shale oil/gas produced water does not contain significant quantities of polyaromatic hydrocarbons reducing the potential health hazard. Marcellus and Barnett produced waters contain predominantly C6-C16 hydrocarbons, while the Eagle Ford produced water shows the highest concentration in the C17-C30 range. The structures of the saturated hydrocarbons identified generally follows the trend of linear > branched > cyclic. Heterocyclic compounds are identified with the largest fraction being fatty alcohols, esters, and ethers. However, the presence of various fatty acid phthalate esters in the Barnett and Marcellus produced waters can be related to their use in drilling fluids and breaker additives

  17. Anti-photoaging and Photoprotective Compounds Derived from Marine Organisms

    PubMed Central

    Pallela, Ramjee; Na-Young, Yoon; Kim, Se-Kwon

    2010-01-01

    Marine organisms form a prominent component of the oceanic population, which significantly contribute in the production of cosmeceutical and pharmaceutical molecules with biologically efficient moieties. In addition to the molecules of various biological activities like anti-bacterial, anti-cancerous, anti-inflammatory and anti-oxidative etc., these organisms also produce potential photoprotective or anti-photoaging agents, which are attracting present day researchers. Continuous exposure to UV irradiation (both UV-A and UV-B) leads to the skin cancer and other photoaging complications, which are typically mediated by the reactive oxygen species (ROS), generated in the oxidative pathways. Many of the anti-oxidative and anti-photoaging compounds have been identified previously, which work efficiently against photodamage of the skin. Recently, marine originated photoprotective or anti-photoaging behavior was observed in the methanol extracts of Corallina pilulifera (CPM). These extracts were found to exert potent antioxidant activity and protective effect on UV-A-induced oxidative stress in human dermal fibroblast (HDF) cells by protecting DNA and also by inhibiting matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to UV-A. The present review depicts various other photoprotective compounds from algae and other marine sources for further elaborative research and their probable use in cosmeceutical and pharmaceutical industries. PMID:20479974

  18. 40 CFR 60.542 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after...) For each green tire spraying operation where both water-based and organic solvent-based sprays...

  19. 40 CFR 60.542 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after...) For each green tire spraying operation where both water-based and organic solvent-based sprays...

  20. 40 CFR 60.542 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after...) For each green tire spraying operation where both water-based and organic solvent-based sprays...

  1. 40 CFR 60.542 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after...) For each green tire spraying operation where both water-based and organic solvent-based sprays...

  2. 40 CFR 60.542 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after...) For each green tire spraying operation where both water-based and organic solvent-based sprays...

  3. Evaluation of the protective effect of chemical additives in the oxidation of phenolic compounds catalysed by peroxidase.

    PubMed

    Torres, Juliana Arriel; Chagas, Pricila Maria Batista; Silva, Maria Cristina; Dos Santos, Custódio Donizete; Corrêa, Angelita Duarte

    2016-01-01

    The use of oxidoredutive enzymes in removing organic pollutants has been the subject of much research. The oxidation of phenolic compounds in the presence of chemical additives has been the focus of this study. In this investigation, the influence of the additives polyethylene glycol and Triton X-100 was evaluated in the phenol oxidation, caffeic acid, chlorogenic acid and total phenolic compounds present in coffee processing wastewater (CPW) at different pH values, performed by turnip peroxidase and peroxidase extracted from soybean seed hulls. The influence of these additives was observed only in the oxidation of phenol and caffeic acid. In the oxidation of other studied phenolic compounds, the percentage of oxidation remained unchanged in the presence of these chemical additives. In the oxidation of CPW in the presence of additives, no change in the oxidation of phenolic compounds was observed. Although several studies show the importance of evaluating the influence of additives on the behaviour of enzymes, this study found a positive response from the economic point of view for the treatment of real wastewater, since the addition of these substances showed no influence on the oxidation of phenolic compounds, which makes the process less costly.

  4. Evaluation of the protective effect of chemical additives in the oxidation of phenolic compounds catalysed by peroxidase.

    PubMed

    Torres, Juliana Arriel; Chagas, Pricila Maria Batista; Silva, Maria Cristina; Dos Santos, Custódio Donizete; Corrêa, Angelita Duarte

    2016-01-01

    The use of oxidoredutive enzymes in removing organic pollutants has been the subject of much research. The oxidation of phenolic compounds in the presence of chemical additives has been the focus of this study. In this investigation, the influence of the additives polyethylene glycol and Triton X-100 was evaluated in the phenol oxidation, caffeic acid, chlorogenic acid and total phenolic compounds present in coffee processing wastewater (CPW) at different pH values, performed by turnip peroxidase and peroxidase extracted from soybean seed hulls. The influence of these additives was observed only in the oxidation of phenol and caffeic acid. In the oxidation of other studied phenolic compounds, the percentage of oxidation remained unchanged in the presence of these chemical additives. In the oxidation of CPW in the presence of additives, no change in the oxidation of phenolic compounds was observed. Although several studies show the importance of evaluating the influence of additives on the behaviour of enzymes, this study found a positive response from the economic point of view for the treatment of real wastewater, since the addition of these substances showed no influence on the oxidation of phenolic compounds, which makes the process less costly. PMID:26502790

  5. Natural production of organic bromine compounds in Berlin Lakes.

    PubMed

    Hütteroth, Alexandra; Putschew, Anke; Jekel, Martin

    2007-05-15

    Berlin surface waters are characterized by elevated concentrations of organic bound bromine (up to 35 microg/L) in late summer. Organic bromine compounds in lakes are of significant importance because human life is closely connected to fresh water. Apart from recreational use, fresh water is frequently used for the production of drinking water, e.g., after bank filtration. Therefore the source, particularly the mechanism responsible for the formation is studied. Field studies indicate that the organic bromine compounds, measured as adsorbable organic bromine (AOBr), are autochthonous. Staggered maxima concentrations of chlorophyll-a, DOC and AOBr indicate that phototrophic organisms might contribute to the AOBr after death. The involvement of phototrophic organisms was established in the laboratory using surface water and/or cultures of organisms. Light and the presence of phototrophic organisms are essential for an AOBr production. Phototrophic organisms incorporate bromide, which is released randomly and after cell death. A part of the incorporated bromide is used for the formation of organic bromine compounds in the cell. After death of the organisms the brominated compounds and the incorporated bromide are released into the water phase, and an extracellular AOBr production can lead to a further formation of AOBr, most probably due to the parallel release of haloperoxidases.

  6. SYNTHESIZING ORGANIC COMPOUNDS USING LIGHT-ACTIVATED TIO2

    EPA Science Inventory

    High-value organic compounds have been synthesized successfully from linear and cyclic hydrocarbons, by photocatalytic oxidation using a semiconductor material, titanium dioxide (TiO2). Various hydrocarbons were partially oxgenated in both liquid and gaseous phase reactors usi...

  7. SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM SURFACTANT SOLUTIONS BY PERVAPORATION

    EPA Science Inventory

    Pervaporation is gradually becoming an accepted and practical method for the recovery of volatile organic compounds (VOCs) from aqueous process and waste streams. As the technolog has matured, new applications for pervaporation have emerged. One such application is the separati...

  8. ESTIMATION OF PHYSIOCHEMICAL PROPERTIES OF ORGANIC COMPOUNDS BY SPARC

    EPA Science Inventory

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  9. Synthesis of fluorinated organic compounds using oxygen difluoride

    NASA Technical Reports Server (NTRS)

    Toy, M. S.

    1971-01-01

    Oxygen difluoride synthesis is a much simpler, higher-yield procedure than reactions originally followed to synthesize various fluorinated organic compounds. Extreme care is taken in working with oxygen difluoride as its reactions present severe explosion hazard.

  10. VOLATILE ORGANIC COMPOUNDS MEASURED IN DEARS PASSIVE SAMPLERS

    EPA Science Inventory

    A suite of 27 volatile organic compounds (VOCs) were monitored in personal exposures, indoors and outdoors of participant's residences, and at a central community site during the DEARS summer 2004 monitoring season. The list of VOCs focused on compounds typically associated with ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. INDOOR AIR QUALITY DATA BASE FOR ORGANIC COMPOUNDS

    EPA Science Inventory

    The report gives results of the compilation of a data base for concentrations of organic compounds measured indoors. ased on a review of the literature from 1979 through 1990, the data base contains information on over 220 compounds ranging in molecular weight from 30 to 446. he ...

  13. The thermodynamic properties of organic oxygen compounds

    NASA Astrophysics Data System (ADS)

    Chirico, R. D.; Steele, W. V.; Hossenlopp, A.; Nguyen, A.; Archer, D. G.; Strube, M. M.

    1988-01-01

    The principles of group additivity are used to compare a series of cyclic hydrocarbons with the corresponding oxygen-containing analogs. The strengths and limitations of the group-additivity method are demonstrated and recommendations are made for measurements essential to the improvement of the accuracy of the predicted properties. The ideal-gas enthalpies of formation and ideal-gas entropies (which are used in combination to calculate Gibbs energies) are considered.

  14. In situ bioremediation of petroleum hydrocarbon and other organic compounds

    SciTech Connect

    Alleman, B.C.; Leeson, A.

    1999-10-01

    From supertanker oil spills to the leaking underground storage tank at the corner gas station, contamination from petroleum hydrocarbon fuels and other organic compounds is an environmental concern that affects nearly every small hamlet and major metropolis throughout the world. Moreover, the world`s rivers, estuaries, and oceans are threatened by contamination from petroleum leaks and spills. Fortunately, most petroleum hydrocarbons are amenable to biodegradation, and a considerable body of experience has been built up over the past two decades in applying in situ bioremediation to a variety of contaminants in all media. Good progress is being made in terms of developing innovative, cost-effective in situ approaches to bioremediation. This volume provides a comprehensive guide to the latest technological breakthroughs in both the laboratory and the field, covering such topics as air sparging, cometabolic biodegradation, treatment of MTBE, real-time control systems, nutrient addition, rapid biosensor analysis, multiphase extraction, and accelerated bioremediation.

  15. Volatile Organic Compound Optical Fiber Sensors: A Review

    PubMed Central

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

    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 possibility of multiplexing, among others, these sensors are a real alternative to electronic ones in electrically noisy environments where electronic sensors cannot operate correctly. In the present work, a classification of these devices has been made according to the sensing mechanism and taking also into account the sensing materials or the different methods of fabrication. In addition, some solutions already implemented for the detection of VOCs using optical fiber sensors will be described with detail.

  16. Shock Modifications of Organic Compounds in Carbonaceous Chondrite Parent Bodies

    NASA Technical Reports Server (NTRS)

    Cooper, George W.

    1998-01-01

    Impacts among asteroidal objects would have altered or destroyed pre-existing organic matter in both targets and projectiles to a greater or lesser degree depending upon impact velocities. To begin filling a knowledge gap on the shock metamorphism of organic compounds, we are studying the effects of shock impacts on selected classes of organic compounds utilizing laboratory shock facilities. Our approach is to subject mixtures of organic compounds, embedded in the matrix of the Murchison meteorite, to simulated hypervelocity impacts by firing them into targets at various pressures. The mixtures are then analyzed to determine the amount of each compound that survives as well as to determine if new compounds are being synthesized. The initial compounds added to the matrix (with the exception of thiosulfate). The sulfonic acids were chosen in part because they are relatively abundant in Murchison, relatively stable, and because they and the phosphonic acids are the first well-characterized homologous series of organic sulfur and phosphorus compounds identified in an extraterrestrial material. Experimental procedures were more fully described in the original proposal. A 20 mm gun, with its barrel extending into a vacuum chamber (10(exp -2) torr), was used to launch the projectile containing the sample at approx. 1.6 km/sec (3,600 mi/hr) into the target material. Maximum pressure of impact depend on target/projectile materials. The target was sufficiently thin to assure minimum pressure decay over the total sample thickness.

  17. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, Robert A.; Laugal, James A.; Rappa, Angela

    1985-01-01

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  18. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, R.A.; Laugal, J.A.; Rappa, A.

    1985-08-06

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  19. Thermodynamics of Organic Compound Alteration in Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Shock, E. L.

    2005-12-01

    Organic compounds enter hydrothermal systems through infiltrating surface waters, zones of microbial productivity in the subsurface, extracts of organic matter in surrounding host rocks, and abiotic synthesis. Owing to variations in pH, oxidation state, composition, temperature, and pressure throughout the changing pathways of fluid migration over the duration of the system, organic compounds from all of these sources are introduced to conditions where their relative stabilities and reactivities can be dramatically transformed. If those transformations were predictable, then the extent to which organic alteration reactions have occurred could be used to reveal flowpaths and histories of hydrothermal systems. Speciation and mass transfer calculations permit some insight into the underlying thermodynamic driving forces that result in organic compound alteration. As an example, the speciation of many geochemist's canonical organic matter: CH2O depends strongly on oxidation state, temperature, and total concentration of dissolved organic matter. Calculations show that at oxidation states buffered by iron-bearing mineral assemblages, organic acids dominate the speciation of CH2O throughout hydrothermal systems, with acetic acid (itself equivalent to 2 CH2O by bulk composition) and propanoic acid generally the most abundant compounds. However, at more reduced conditions, which may prevail in organic-rich iron-poor sediments, the drive is to form ketones and especially alcohols at the expense of organic acids. The distribution of organic carbon among the various members of these compound classes is strongly dependent on the total concentration of dissolved organic matter. As an example, at a bulk concentration equivalent to average dissolved organic matter in seawater (45μm), the dominant alcohols at 100°C are small compounds like ethanol and 1-propanol. In contrast, at a higher bulk concentration of 500μm, there is a drive to shift large percentages of dissolved

  20. Fast, greener and scalable direct coupling of organolithium compounds with no additional solvents

    PubMed Central

    Pinxterhuis, Erik B.; Giannerini, Massimo; Hornillos, Valentín; Feringa, Ben L.

    2016-01-01

    Although the use of catalytic rather than stoichiometric amounts of metal mediator in cross-coupling reactions between organic halides and organometallic counterparts improves significantly the atom economy and waste production, the use of solvents and stoichiometric generation of main-group byproducts (B, Sn and Zn) hamper the ‘greenness' and industrial efficiency of these processes. Here we present a highly selective and green Pd-catalysed cross-coupling between organic halides and organolithium reagents proceeding without additional solvents and with short reaction times (10 min). This method bypasses a number of challenges previously encountered in Pd-catalysed cross-coupling with organolithium compounds such as strict exclusion of moisture, dilution and slow addition. Operational ease of this protocol combines the use of industrially viable catalysts loadings (down to 0.1 mol%), scalability of the process (tested up to 120 mmol) and exceptionally favourable environmental impact (E factors in several cases as low as 1). PMID:27251636

  1. Analysis of volatile organic compounds from illicit cocaine samples

    SciTech Connect

    Robins, W.H.; Wright, B.W.

    1994-07-01

    Detection of illicit cocaine hydrochloride shipments can be improved if there is a greater understanding of the identity and quantity of volatile compounds present. This study provides preliminary data concerning the volatile organic compounds detected in a limited Set of cocaine hydrochloride samples. In all cases, cocaine was one of the major volatile compounds detected. Other tropeines were detected in almost all samples. Low concentrations of compounds that may be residues of processing solvents were observed in some samples. The equilibrium emissivity of. cocaine from cocaine hydrochloride was investigated and a value of 83 parts-per-trillion was determined.

  2. Recent advances in trifluoromethylation of organic compounds using Umemoto's reagents.

    PubMed

    Zhang, Cai

    2014-09-14

    The incorporation of fluorine-containing moieties into organic compounds is of great importance in pharmaceutical, agricultural, and materials science. Within these organofluorides, the trifluoromethyl group is one of the most important motifs. In recent years, the trifluoromethyl group has attracted more and more attention, and many trifluoromethylated compounds have been found to possess special activities. However, until now, only a few methods have been developed to achieve this efficiently using Umemoto's reagents. This review highlights recent developments in the direct introduction of a trifluoromethyl group into organic compounds with Umemoto's reagents. Seven approaches to the trifluoromethylation of organic compounds are summarized: (i) trifluoromethylation of arenes, (ii) trifluoromethylation of alkenes, (iii) trifluoromethylation of terminal alkynes, (iv) deoxygenative trifluoromethylation of benzylic xanthates, (v) trifluoromethylation of ketoesters, (vi) trifluoromethylation of aryl boronic acids and aromatic amines (synthesis of ArCF3) and (vii) trifluoromethylation of biphenyl isocyanide derivatives. PMID:25011917

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Multifunctional slow-release organic-inorganic compound fertilizer.

    PubMed

    Ni, Boli; Liu, Mingzhu; Lü, Shaoyu; Xie, Lihua; Wang, Yanfang

    2010-12-01

    Multifunctional slow-release organic-inorganic compound fertilizer (MSOF) has been investigated to improve fertilizer use efficiency and reduce environmental pollution derived from fertilizer overdosage. The special fertilizer is based on natural attapulgite (APT) clay used as a matrix, sodium alginate used as an inner coating and sodium alginate-g-poly(acrylic acid-co-acrylamide)/humic acid (SA-g-P(AA-co-AM)/HA) superabsorbent polymer used as an outer coating. The coated multielement compound fertilizer granules were produced in a pan granulator, and the diameter of the prills was in the range of 2.5-3.5 mm. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nutrients release, were examined. In addition, a mathematical model for nutrient release from the fertilizer was applied to calculate the diffusion coefficient D of nutrients in MSOF. The degradation of the SA-g-P(AA-co-AM)/HA coating was assessed by examining the weight loss with incubation time in soil. It is demonstrated that the product prepared by a simple route with good slow-release property may be expected to have wide potential applications in modern agriculture and horticulture. PMID:21058723

  5. Multifunctional slow-release organic-inorganic compound fertilizer.

    PubMed

    Ni, Boli; Liu, Mingzhu; Lü, Shaoyu; Xie, Lihua; Wang, Yanfang

    2010-12-01

    Multifunctional slow-release organic-inorganic compound fertilizer (MSOF) has been investigated to improve fertilizer use efficiency and reduce environmental pollution derived from fertilizer overdosage. The special fertilizer is based on natural attapulgite (APT) clay used as a matrix, sodium alginate used as an inner coating and sodium alginate-g-poly(acrylic acid-co-acrylamide)/humic acid (SA-g-P(AA-co-AM)/HA) superabsorbent polymer used as an outer coating. The coated multielement compound fertilizer granules were produced in a pan granulator, and the diameter of the prills was in the range of 2.5-3.5 mm. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nutrients release, were examined. In addition, a mathematical model for nutrient release from the fertilizer was applied to calculate the diffusion coefficient D of nutrients in MSOF. The degradation of the SA-g-P(AA-co-AM)/HA coating was assessed by examining the weight loss with incubation time in soil. It is demonstrated that the product prepared by a simple route with good slow-release property may be expected to have wide potential applications in modern agriculture and horticulture.

  6. Constituents of volatile organic compounds of evaporating essential oil

    NASA Astrophysics Data System (ADS)

    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.

  7. Membrane bioreactor for control of volatile organic compound emissions

    SciTech Connect

    Ergas, S.J.; McGrath, M.S.

    1997-06-01

    A membrane bioreactor system that overcomes many of the limitations of conventional compost biofilters is described. The system utilizes microporous hydrophobic hollow fiber membranes for mass transfer of volatile organic compounds (VOCs) from the gas phase to a microbially active liquid phase. The reactor design provides a high biomass concentration, a method for wasting biomass, and a method for addition of pH buffers, nutrients, cometabolites, and/or other amendments. A theoretical model is developed, describing mass transfer and biodegradation in the membrane bioreactor. Reactor performance was determined in a laboratory scale membrane bioreactor over a range of gas loading rates using toluene as a model VOC. Toluene removal efficiency was greater than 98% at an inlet concentration of 100 ppm, and a gas residence time of less than 2 s. Factors controlling bioreactor performance were determined through both experiments and theoretical modeling to include: compound Henry`s law constant, membrane specific surface area, gas and VOC loading rates, liquid phase turbulence, and biomass substrate utilization rate.

  8. Semivolatile organic compounds in urban and over-water atmospheres

    NASA Astrophysics Data System (ADS)

    Offenberg, John H., Jr.

    Concentrations of semi-volatile organic contaminants were measured both in air and precipitation in and downwind of Chicago, IL and Baltimore, MD as part of the A_tmospheric E_xchange O_ver L_akes and O_ceans_ (AEOLOS) project. Precipitation events were collected simultaneously in the city and over the water to measure increased wet depositional fluxes of polychlorinated biphenyls to Lake Michigan during May and July 1994 and January 1995. Elevated atmospheric concentrations in Chicago, IL increase atmospheric loadings of PCBs to Lake Michigan by at least a factor of two over regional background levels. Precipitation loadings, bidirectional gas exchange and dry deposition combine to increase measured surface water concentrations of PCBs in Lake Michigan during periods of southwesterly winds which transport the urban air mass across the lake. PCB concentrations in surface waters were higher during winter than in spring or summer, but PAH concentrations did not vary significantly with season. However, when placed in historical context, Lake Michigan PCB concentrations have declined ten fold over fourteen years from 1980 to 1994. Size segregated airborne particulate samples collected around and over southern Lake Michigan show geometric mean diameters of polycyclic aromatic hydrocarbons that are correlated with the compound's sub-cooled liquid vapor pressures. More volatile compounds were found on larger particles. The slope of the relationship between GMD and vapor pressure depends on the transit time from the shoreline, suggesting that higher wind speeds induce faster dry deposition of large particles. Measured gas/particle partitioning of these compounds is modeled according to a three dimensional multiple linear regression that includes the influences of vapor pressure, particle size and measured aerosol fractional organic carbon content. Each of these terms is significant in the full model but, addition of the latter two terms appears to be practically

  9. Foam concrete with porous mineral and organic additives

    NASA Astrophysics Data System (ADS)

    Kudiakov, A.; Prischepa, I.; Tolchennickov, M.

    2015-01-01

    The article presents results of studies of structural heat insulating foam concrete with porous mineral and organic additives. By mixing additives with the concrete the speed of the initial structure formation increases. The additives of ash loss and thermal-modified peat TMT 600 provide a stable increase of strength by compression and bending of foam concrete. In the dried foam concrete with the addition of TMT and ash loss thermal conductivity decreases by 20% and 7% respectively. The regularities of changes in the thermal conductivity at various moisture of foam concrete have been investigated.

  10. New Aspects of Zirconium Containing Organic Compounds

    NASA Astrophysics Data System (ADS)

    Marek, Ilan

    Metal carbene complexes have made their way from organometallic curiosities to valuable reagents and catalysts. They offer novel synthetic opportunities in carbon-carbon bond formation based on either carbene-centered reactions or on metal-templated processes which makes them indispensable in modern synthetic methodology. The most prominent metal carbenes are now either commercially available or easy to synthesize and handle with modern laboratory techniques. This volume organized in eight chapters written by the leading scientists in the field illustrates the theoretical background, non-classical nucleophilic and cycloaddition patterns, chromium-templated benzannulation and photo-induced reactions, rhodium-catalyzed carbene transfer as well as the principles and applications of olefin metathesis which has coined the progress in synthetic methodology over the past decade.

  11. Scaffold of Asymmetric Organic Compounds - Magnetite Plaquettes

    NASA Technical Reports Server (NTRS)

    Chan, Q. H. S.; Zolensky, M. E.; Martinez, J.

    2015-01-01

    Life on Earth shows preference towards the set of organics with particular spatial configurations, this 'selectivity' is a crucial criterion for life. With only rare exceptions, life prefers the left- (L-) form over the right- (D-) form of amino acids, resulting in an L-enantiomeric excess (L-ee). Recent studies have shown Lee for alpha-methyl amino acids in some chondrites. Since these amino acids have limited terrestrial occurrence, the origin of their stereoselectivity is nonbiological, and it seems appropriate to conclude that chiral asymmetry, the molecular characteristic that is common to all terrestrial life form, has an abiotic origin. A possible abiotic mechanism that can produce chiral asymmetry in meteoritic amino acids is their formation with the presence of asymmetric catalysts, as mineral crystallization can produce spatially asymmetric structures. Magnetite is shown to be an effective catalyst for the formation of amino acids that are commonly found in chondrites. Magnetite 'plaquettes' (or 'platelets'), first described by Jedwab, show an interesting morphology of barrel-shaped stacks of magnetite disks with an apparent dislocation-induced spiral growth that seem to be connected at the center. A recent study by Singh et al. has shown that magnetites can self-assemble into helical superstructures. Such molecular asymmetry could be inherited by adsorbed organic molecules. In order to understand the distribution of 'spiral' magnetites in different meteorite classes, as well as to investigate their apparent spiral configurations and possible correlation to molecular asymmetry, we observed polished sections of carbonaceous chondrites (CC) using scanning electron microscope (SEM) imaging. The sections were also studied by electron backscattered diffraction (EBSD) in order to reconstruct the crystal orientation along the stack of magnetite disks.

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

    PubMed

    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. PMID:25236204

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

    PubMed

    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.

  14. Hydrophobic Organic Compounds in Hydraulic Fracturing Flowback Waters: Identification and Source Apportionment

    NASA Astrophysics Data System (ADS)

    Plata, D.; Shregglman, K.; Elsner, M.; Getzinger, G.; Ferguson, L.; Drollette, B.; Karatum, O.; Nelson, R. K.; Reddy, C. M.

    2014-12-01

    Current hydraulic fracturing technologies rely on organic chemicals to serve multiple critical functions, including corrosion inhibition, in situ gel formation, and friction reduction. While industrial users have disclosed several hundreds of compound and mixture identities, it is unclear which of these are used and where, in what proportion, and with what frequency. Furthermore, while flowback and production waters contain both fracturing additive and geogenic compounds, they may contain potential reaction byproducts as well. Here, we identified several hundred organic compounds present in six hydraulic fracturing flowback waters over the Fayetteville shale. Identifications were made via non-target analysis using two-dimensional gas chromatography with time of flight mass spectrometry for hydrophobic organic compounds and liquid chromatography- orbitrap mass spectrometry. Compound identities were confirmed using purchased standards when available. Using the SkyTruth database and the Waxman list of disclosed compounds, we assigned compounds as either fracturing-fluid-derived or geogenic (or both), or a putative transformation products thereof. Several unreported halogenated compounds were detected, including chlorinated, brominated, and iodated species that have no known natural sources. Control studies indicated that these could not be formed under typical laboratory or field storage conditions, suggesting that halogenation reactions may give rise to novel compounds in the subsurface, presumably via reaction between fracturing fluid additives and shale-derived brines. Further, the six samples were strikingly heterogeneous, reflecting the diversity in fracturing fluid composition and flowback handling procedures at the time of the study.

  15. Chemical reactions of organic compounds on clay surfaces

    SciTech Connect

    Soma, Yuko; Soma, Mitsuyuki )

    1989-11-01

    Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, and the Broensted or Lewis acidity of clay minerals.

  16. INTERACTIONS BETWEEN ORGANIC COMPOUNDS AND CYCLODEXTRIN-CLAY SYSTEMS

    EPA Science Inventory

    Computational and experimental techniques are combined in order to better understand interactions involving organic compounds and cyclodextrin (CD)-clay systems. CD-clay systems may have great potential in the containment of organic contaminants in the environment. This study w...

  17. LOSS OF ORGANIC CHEMICALS IN SOIL: PURE COMPOUND TREATABILITY STUDIES

    EPA Science Inventory

    Comprehensive screening data on the treatability of 32 organic chemicals in soil were developed. Of the evaluated chemicals, 22 were phenolic compounds. Aerobic batch laboratory microcosm experiments were conducted using two soils: an acidic clay soil with <1% organic matter and ...

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

    EPA Science Inventory

    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...

  19. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  20. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 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...

  1. 40 CFR 60.392 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  2. 40 CFR 60.392 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  3. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  4. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  5. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 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...

  6. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    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...

  7. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 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...

  8. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 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...

  9. Leveraging the beneficial compounds of organic and pasture milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much discussion has arisen over the possible benefits of organic food, including milk. Organic milk comes from cows that are on pasture during the growing season, and would be expected to contain some compounds that are not found in animals receiving conventional feed, or at higher concentrations. ...

  10. Students' Understanding of Molecular Structure and Properties of Organic Compounds.

    ERIC Educational Resources Information Center

    Schmidt, Hans-Jurgen

    The purpose of this study was to investigate senior high school students' difficulties predicting the existence of hydrogen bridge bonds between organic molecules, investigate students' difficulties predicting the relative boiling points of simple organic compounds, and develop test questions that enable teachers to quickly get information about…

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

    SciTech Connect

    Ma Fengji; Liu Shuxia; Liang Dadong; Ren Guojian; Wei Feng; Chen Yaguang; Su Zhongmin

    2011-11-15

    The functionalization of porous metal-organic frameworks (Cu{sub 3}(BTC){sub 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{sub 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. - Graphical Abstract: The adsorption behavior of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates has been systematically evaluated. Highlights: > Functionalization of MOFs was achieved by incorporating Keggin-type POMs. > Introduction of POMs improved the thermal stability and adsorption capacity. > Alkali metal ion-exchange modified the inclusion state and also enhanced the adsorption. > Adsorption enthalpies were estimated to study the impact of POMs and alkali metal cations.

  12. Magnesium silicates adsorbents of organic compounds

    NASA Astrophysics Data System (ADS)

    Ciesielczyk, Filip; Krysztafkiewicz, Andrzej; Jesionowski, Teofil

    2007-08-01

    Studies were presented on production of highly dispersed magnesium silicate at a pilote scale. The process of silicate adsorbent production involved precipitation reaction using water glass (sodium metasilicate) solution and appropriate magnesium salt, preceded by an appropriate optimization stage. Samples of best physicochemical parameters were in addition modified (in order to introduce to silica surface of several functional groups) using the dry technique and various amounts of 3-isocyanatepropyltrimethoxysilane, 3-thiocyanatepropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane. The so prepared samples were subjected to a comprehensive physicochemical analysis. At the terminal stage of studies attempts were made to adsorb phenol from its aqueous solutions on the surface of unmodified and modified magnesium silicates. Particle size distributions were determined using the ZetaSizer Nano ZS apparatus. In order to define adsorptive properties of studied magnesium silicates isotherms of nitrogen adsorption/desorption on their surfaces were established. Efficiency of phenol adsorption was tested employing analysis of post-adsorption solution.

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

    NASA Astrophysics Data System (ADS)

    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. Emission of volatile organic compounds to the atmosphere in the solvent sublation process. II. Volatile chlorinated organic compounds

    SciTech Connect

    Ososkov, V.; Kebbekus, B.; Chou, C.C.

    1996-06-01

    The mass of trichloroethylene, chlorobenzene, and 1,3-dichlorobenzene removed from an aqueous solution and emitted to the atmosphere during solvent sublation was determined experimentally. It was shown that the emission of these compounds in solvent sublation was reduced by 30 to 85% over air stripping under the same experimental conditions. The efficiency of removal of these compounds from water was also studied. The reduction of emissions over air stripping was more effective for the more hydrophobic and less volatile compounds. Emissions are reduced as the thickness of organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emissions to a greater extent than does paraffin oil. Removal of these chlorinated volatile organic compounds from water by solvent sublation at an elevated temperature of 45{degrees}C is significantly faster than at room temperature. However, the emissions to the atmosphere are also increased.

  15. Use of Bromine and Bromo-Organic Compounds in Organic Synthesis.

    PubMed

    Saikia, Indranirekha; Borah, Arun Jyoti; Phukan, Prodeep

    2016-06-22

    Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis. PMID:27199233

  16. Use of Bromine and Bromo-Organic Compounds in Organic Synthesis.

    PubMed

    Saikia, Indranirekha; Borah, Arun Jyoti; Phukan, Prodeep

    2016-06-22

    Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

  17. Catalytic combustion of volatile organic compounds.

    PubMed

    Everaert, K; Baeyens, J

    2004-06-18

    Despite the success of adsorption and thermal incineration of (C)VOC emissions, there is still a need for research on techniques which are both economically more favorable and actually destroy the pollutants rather than merely remove them for recycling elsewhere in the biosphere. The catalytic destruction of (C)VOC to CO2, H2O and HCl/Cl2 appears very promising in this context and is the subject of the present paper. The experiments mainly investigate the catalytic combustion of eight target compounds, all of which are commonly encountered in (C)VOC emissions and/or act as precursors for the formation of PCDD/F. Available literature on the different catalysts active in the oxidation of (C)VOC is reviewed and the transition metal oxide complex V2O5-WO3/TiO2 appears most suitable for the current application. Different reactor geometries (e.g. fixed pellet beds, honeycombs, etc.) are also described. In this research a novel catalyst type is introduced, consisting of a V2O5-WO3/TiO2 coated metal fiber fleece. The conversion of (C)VOC by thermo-catalytic reactions is governed by both reaction kinetics and reaction equilibrium. Full conversion of all investigated VOC to CO2, Cl2, HCl and H2O is thermodynamically feasible within the range of experimental conditions used in this work (260-340 degrees C, feed concentrations 30-60 ppm). A first-order rate equation is proposed for the (C)VOC oxidation reactions. The apparent rate constant is a combination of reaction kinetics and mass transfer effects. The oxidation efficiencies were measured with various (C)VOC in the temperature range of 260-340 degrees C. Literature data for oxidation reactions in fixed beds and honeycomb reactors are included in the assessment. Mass transfer resistances are calculated and are generally negligible for fleece reactors and fixed pellet beds, but can be of importance for honeycomb monoliths. The experimental investigations demonstrate: (i) that the conversion of the hydrocarbons is

  18. Composition and major sources of organic compounds in urban aerosols

    NASA Astrophysics Data System (ADS)

    Bi, Xinhui; Simoneit, Bernd R. T.; Sheng, Guoying; Ma, Shexia; Fu, Jiamo

    Total suspended particles (TSP), collected during June 2002 to July 2003 in Guangzhou, a typical economically developed city in South China, were analyzed for the organic compound compositions using gas chromatography-mass spectrometry (GC/MS). Over 140 organic compounds were detected in the aerosols and grouped into different classes including n-alkanes, hopanoids, polycyclic aromatic hydrocarbons, alkanols, fatty acids, dicarboxylic acids excluding oxalic acid, polyols/polyacids, lignin products, phytosterols, phthalates and water-soluble sugars. The total amounts of the identified organic compounds including unresolved complex mixture (UCM) ranged from 3112 ng/m 3 in spring to 5116 ng/m 3 in winter, comprising on seasonal average 2.8% of TSP. Primary organic compounds peaked in winter although there are no heating systems burning fuels in Guangzhou. The highest saccharide levels occurred in fall due to agricultural activities. This study demonstrated that utilization of fossil fuels, biomass burning, soil resuspension and plastic/refuse burning are the major contributors to the identified organic compounds in the urban atmosphere of South China.

  19. Field-usable portable analyzer for chlorinated organic compounds

    SciTech Connect

    Buttner, W.J.; Penrose, W.R.; Stetter, J.R.

    1995-10-01

    Transducer Research, Inc. (TRI) has been working with the DOE Morgantown Energy Technology Center to develop a new chemical monitor based on a unique sensor which responds selectively to vapors of chlorinated solvents. We are also developing field applications for the monitor in actual DOE cleanup operations. During the initial phase, prototype instruments were built and field tested. Because of the high degree of selectivity that is obtained, no response was observed with common hydrocarbon organic compounds such as BTX (benzene, toluene, xylene) or POLs (petroleum, oil, lubricants), and in fact, no non-halogen-containing chemical has been identified which induces a measurable response. By the end of the Phase I effort, a finished instrument system was developed and test marketed. This instrument, called the RCL MONITOR, was designed to analyze individual samples or monitor an area with automated repetitive analyses. Vapor levels between 0 and 500 ppm can be determined in 90 s with a lower detection limit of 0.2 ppm using the handportable instrument. In addition to the development of the RCL MONITOR, advanced sampler systems are being developed to: (1) extend the dynamic range of the instrument through autodilution of the vapor and (2) allow chemical analyses to be performed on aqueous samples. When interfaced to the samplers, the RCL MONITOR is capable of measuring chlorinated solvent contamination in the vapor phase up to 5000 ppm and in water and other condensed media from 10 to over 10,000 ppb(wt)--without hydrocarbon and other organic interferences.

  20. Organic additives stabilize RNA aptamer binding of malachite green.

    PubMed

    Zhou, Yubin; Chi, Hong; Wu, Yuanyuan; Marks, Robert S; Steele, Terry W J

    2016-11-01

    Aptamer-ligand binding has been utilized for biological applications due to its specific binding and synthetic nature. However, the applications will be limited if the binding or the ligand is unstable. Malachite green aptamer (MGA) and its labile ligand malachite green (MG) were found to have increasing apparent dissociation constants (Kd) as determined through the first order rate loss of emission intensity of the MGA-MG fluorescent complex. The fluorescent intensity loss was hypothesized to be from the hydrolysis of MG into malachite green carbinol base (MGOH). Random screening organic additives were found to reduce or retain the fluorescence emission and the calculated apparent Kd of MGA-MG binding. The protective effect became more apparent as the percentage of organic additives increased up to 10% v/v. The mechanism behind the organic additive protective effects was primarily from a ~5X increase in first order rate kinetics of MGOH→MG (kMGOH→MG), which significantly changed the equilibrium constant (Keq), favoring the generation of MG, versus MGOH without organic additives. A simple way has been developed to stabilize the apparent Kd of MGA-MG binding over 24h, which may be beneficial in stabilizing other triphenylmethane or carbocation ligand-aptamer interactions that are susceptible to SN1 hydrolysis.

  1. Organic additives stabilize RNA aptamer binding of malachite green.

    PubMed

    Zhou, Yubin; Chi, Hong; Wu, Yuanyuan; Marks, Robert S; Steele, Terry W J

    2016-11-01

    Aptamer-ligand binding has been utilized for biological applications due to its specific binding and synthetic nature. However, the applications will be limited if the binding or the ligand is unstable. Malachite green aptamer (MGA) and its labile ligand malachite green (MG) were found to have increasing apparent dissociation constants (Kd) as determined through the first order rate loss of emission intensity of the MGA-MG fluorescent complex. The fluorescent intensity loss was hypothesized to be from the hydrolysis of MG into malachite green carbinol base (MGOH). Random screening organic additives were found to reduce or retain the fluorescence emission and the calculated apparent Kd of MGA-MG binding. The protective effect became more apparent as the percentage of organic additives increased up to 10% v/v. The mechanism behind the organic additive protective effects was primarily from a ~5X increase in first order rate kinetics of MGOH→MG (kMGOH→MG), which significantly changed the equilibrium constant (Keq), favoring the generation of MG, versus MGOH without organic additives. A simple way has been developed to stabilize the apparent Kd of MGA-MG binding over 24h, which may be beneficial in stabilizing other triphenylmethane or carbocation ligand-aptamer interactions that are susceptible to SN1 hydrolysis. PMID:27591602

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  4. GROUNDWATER TRANSPORT OF HYDROPHOBIC ORGANIC COMPOUNDS IN THE PRESENCE OF DISSOLVED ORGANIC MATTER

    EPA Science Inventory

    The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. Three compounds (naphthalene, phenanthrene and DDT) that spanned three orders of magnitude in water solubility were used. Instead of humic matter, mo...

  5. Dosimeter for monitoring vapors and aerosols of organic compounds

    DOEpatents

    Vo-Dinh, T.

    1987-07-14

    A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique. 7 figs.

  6. Dosimeter for monitoring vapors and aerosols of organic compounds

    DOEpatents

    Vo-Dinh, Tuan

    1987-01-01

    A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique.

  7. Nitrogen Additions Increase the Diversity of Carbon Compounds Degraded by Fungi in Boreal Forests

    NASA Astrophysics Data System (ADS)

    Gartner, T. B.; Turner, K. M.; Treseder, K. K.

    2004-12-01

    Boreal forest soils in North America harbor a large reservoir of organic C, and this region is increasingly exposed to long-range atmospheric N transport from Eurasia. By examining the responses of decomposers to N deposition in these forests, we hope to improve predictions of the fate of boreal carbon pools under global change. We tested the hypothesis that the functional diversity of decomposer fungi would increase under N fertilization in boreal forests where fungal growth was otherwise N-limited, owing to a reduction in competitive exclusion of fungal groups. We collected soil and leaf litter from three Alaskan sites that represent different successional stages at 5, 17, or 80 years following severe forest fire. Each site had been exposed for two years to nitrogen and phosphorus fertilization in a factorial design, with four plots per treatment. Nutrient limitation of fungal growth varied depending on successional stage. The standing hyphal length of decomposer fungi in soil (i.e. Ascomycota and Basidiomycota) responded to neither N nor P in the 5-year old site, increased under N fertilization in the 17-year old site, and increased where N and P was added simultaneously in the 80-year old site (site x N x P interaction: P = 0.001). We used BIOLOG microplates for filamentous fungi to obtain an index of the diversity of carbon use by decomposer fungi; each of 95 wells of these plates contains a different carbon-based compound, as well as a dye that changes color upon metabolism of the compound. Saline leaf litter extracts were mixed with fungal growth medium and then added to the microplates. The number of wells displaying metabolic activity was counted following incubation for five days. We found that N fertilization raised the average number of positive wells per plate from 14 to 27 (P = 0.012), with no significant differences in responses among sites. Phosphorus additions did not alter functional diversity of fungi in any site. Since increases in functional

  8. Simplified Production of Organic Compounds Containing High Enantiomer Excesses

    NASA Technical Reports Server (NTRS)

    Cooper, George W. (Inventor)

    2015-01-01

    The present invention is directed to a method for making an enantiomeric organic compound having a high amount of enantiomer excesses including the steps of a) providing an aqueous solution including an initial reactant and a catalyst; and b) subjecting said aqueous solution simultaneously to a magnetic field and photolysis radiation such that said photolysis radiation produces light rays that run substantially parallel or anti-parallel to the magnetic field passing through said aqueous solution, wherein said catalyst reacts with said initial reactant to form the enantiomeric organic compound having a high amount of enantiomer excesses.

  9. Detection of Organic Compounds with Whole-Cell Bioluminescent Bioassays

    PubMed Central

    Xu, Tingting; Close, Dan; Smartt, Abby; Ripp, Steven

    2015-01-01

    Natural and manmade organic chemicals are widely deposited across a diverse range of ecosystems including air, surface water, groundwater, wastewater, soil, sediment, and marine environments. Some organic compounds, despite their industrial values, are toxic to living organisms and pose significant health risks to humans and wildlife. Detection and monitoring of these organic pollutants in environmental matrices therefore is of great interest and need for remediation and health risk assessment. Although these detections have traditionally been performed using analytical chemical approaches that offer highly sensitive and specific identification of target compounds, these methods require specialized equipment and trained operators, and fail to describe potential bioavailable effects on living organisms. Alternatively, the integration of bioluminescent systems into whole-cell bioreporters presents a new capacity for organic compound detection. These bioreporters are constructed by incorporating reporter genes into catabolic or signaling pathways that are present within living cells and emit a bioluminescent signal that can be detected upon exposure to target chemicals. Although relatively less specific compared to analytical methods, bioluminescent bioassays are more cost-effective, more rapid, can be scaled to higher throughput, and can be designed to report not only the presence but also the bioavailability of target substances. This chapter reviews available bacterial and eukaryotic whole-cell bioreporters for sensing organic pollutants and their applications in a variety of sample matrices. PMID:25084996

  10. Detection of organic compounds with whole-cell bioluminescent bioassays.

    PubMed

    Xu, Tingting; Close, Dan; Smartt, Abby; Ripp, Steven; Sayler, Gary

    2014-01-01

    Natural and manmade organic chemicals are widely deposited across a diverse range of ecosystems including air, surface water, groundwater, wastewater, soil, sediment, and marine environments. Some organic compounds, despite their industrial values, are toxic to living organisms and pose significant health risks to humans and wildlife. Detection and monitoring of these organic pollutants in environmental matrices therefore is of great interest and need for remediation and health risk assessment. Although these detections have traditionally been performed using analytical chemical approaches that offer highly sensitive and specific identification of target compounds, these methods require specialized equipment and trained operators, and fail to describe potential bioavailable effects on living organisms. Alternatively, the integration of bioluminescent systems into whole-cell bioreporters presents a new capacity for organic compound detection. These bioreporters are constructed by incorporating reporter genes into catabolic or signaling pathways that are present within living cells and emit a bioluminescent signal that can be detected upon exposure to target chemicals. Although relatively less specific compared to analytical methods, bioluminescent bioassays are more cost-effective, more rapid, can be scaled to higher throughput, and can be designed to report not only the presence but also the bioavailability of target substances. This chapter reviews available bacterial and eukaryotic whole-cell bioreporters for sensing organic pollutants and their applications in a variety of sample matrices.

  11. Recovery of several volatile organic compounds from simulated water samples: Effect of transport and storage

    USGS Publications Warehouse

    Friedman, L.C.; Schroder, L.J.; Brooks, M.G.

    1986-01-01

    Solutions containing volatile organic compounds were prepared in organic-free water and 2% methanol and submitted to two U.S. Geological Survey laboratories. Data from the determination of volatile compounds in these samples were compared to analytical data for the same volatile compounds that had been kept in solutions 100 times more concentrated until immediately before analysis; there was no statistically significant difference in the analytical recoveries. Addition of 2% methanol to the storage containers hindered the recovery of bromomethane and vinyl chloride. Methanol addition did not enhance sample stability. Further, there was no statistically significant difference in results from the two laboratories, and the recovery efficiency was more than 80% in more than half of the determinations made. In a subsequent study, six of eight volatile compounds showed no significant loss of recovery after 34 days.

  12. Screening of volatile organic compounds in river sediment

    SciTech Connect

    Kawata, K.; Tanabe, A.; Saito, S.

    1997-06-01

    Volatile organic compounds (VOCs), such as trichloroethene, toluene and xylenes have been reported to be detected from river water and sediment, because a part of VOCs charged into river can be distributed to river sediment. Fifty-three common VOCs in water have been simultaneously determined with good accuracy and precision by gas chromatography - mass spectrometry (GC/MS) with headspace method as well as purge-and-trap method. However, simultaneous determination methods for the VOCs in sediment have not been established. Several GC or GOMS methods have been reported to determine some VOCs in sediment, purge-and-trap, distillation, headspace and solvent extraction. Among them headspace GC/MS method appears to be the most appropriate method for screening the VOCs in sediments, because of its simplicity in analytical procedure. Hewitt et al. have reported that headspace method gave no statistically different results from purge-and-trap method for GC/MS determination of four VOCs in soil. Voice and Kolb have reported that headspace GC method gave better results to determine nine VOCs in soil than purge-and-trap method or solvent extraction method followed by headspace. However, headspace analysis of some VOCs in sediments could give insufficient recoveries. This is because VOCs adsorb to sediment. To improve their low recoveries from sediment, we have previously used a stable isotope-labeled compound as an internal standard to determine eight chlorinated VOCs. However, this method is not proper for determining simultaneously as many as 53 VOCs with various physical properties. Therefore, we investigate headspace GC/MS method with standard addition method for simultaneous screening of them in sediment. In this paper, we describe effects of a few headspace conditions on the VOC recoveries from sediment, and present screening results of the VOCs in sediments from mouths of rivers and a port in Niigata, Japan. 17 refs., 3 figs., 3 tabs.

  13. Chemical reactions of organic compounds on clay surfaces.

    PubMed Central

    Soma, Y; Soma, M

    1989-01-01

    Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, and the Brönsted or Lewis acidity of clay minerals. PMID:2533556

  14. Volatile organic compounds in polyethylene bags-A forensic perspective.

    PubMed

    Borusiewicz, Rafał; Kowalski, Rafał

    2016-09-01

    Polyethylene bags, though not recommended, are sometimes used in some countries as improvised packaging for items sent to be analysed for the presence of volatile organic compounds, namely ignitable liquids residues. Sometimes items made of polyethylene constitute the samples themselves. It is well known what kind of volatile organic compounds are produced as a result of polyethylene thermal decomposition, but there is a lack of information relating to if some volatile compounds are present in unheated/unburned items made of polyethylene in detectable amounts and, if so, what those compounds are. The aim of this presented research was to answer these questions. 28 different bags made of polyethylene, representing 9 brands, were purchased in local shops and analysed according to the procedure routinely used for fire debris. The results proved that in almost all bags a distinctive mixture of compounds is present, comprising of n-alkanes and n-alkenes with an even number of carbon atoms in their molecules. Some other compounds (e.g., limonene, 2,2,4,6,6-pentamethylheptane) are also often present, but the presence of even n-alkanes and n-alkenes constitutes the most characteristic feature. PMID:27458996

  15. Volatile organic compounds in polyethylene bags-A forensic perspective.

    PubMed

    Borusiewicz, Rafał; Kowalski, Rafał

    2016-09-01

    Polyethylene bags, though not recommended, are sometimes used in some countries as improvised packaging for items sent to be analysed for the presence of volatile organic compounds, namely ignitable liquids residues. Sometimes items made of polyethylene constitute the samples themselves. It is well known what kind of volatile organic compounds are produced as a result of polyethylene thermal decomposition, but there is a lack of information relating to if some volatile compounds are present in unheated/unburned items made of polyethylene in detectable amounts and, if so, what those compounds are. The aim of this presented research was to answer these questions. 28 different bags made of polyethylene, representing 9 brands, were purchased in local shops and analysed according to the procedure routinely used for fire debris. The results proved that in almost all bags a distinctive mixture of compounds is present, comprising of n-alkanes and n-alkenes with an even number of carbon atoms in their molecules. Some other compounds (e.g., limonene, 2,2,4,6,6-pentamethylheptane) are also often present, but the presence of even n-alkanes and n-alkenes constitutes the most characteristic feature.

  16. Non-targeted analyses of organic compounds in urban wastewater.

    PubMed

    Alves Filho, Elenilson G; Sartori, Luci; Silva, Lorena M A; Silva, Bianca F; Fadini, Pedro S; Soong, Ronald; Simpson, Andre; Ferreira, Antonio G

    2015-09-01

    A large number of organic pollutants that cause damage to the ecosystem and threaten human health are transported to wastewater treatment plants (WWTPs). The problems regarding water pollution in Latin America have been well documented, and there is no evidence of substantive efforts to change the situation. In the present work, two methods to study wastewater samples are employed: non-targeted 1D ((13)C and (1)H) and 2D NMR spectroscopic analysis to characterize the largest possible number of compounds from urban wastewater and analysis by HPLC-(UV/MS)-SPE-ASS-NMR to detect non-specific recalcitrant organic compounds in treated wastewater without the use of common standards. The set of data is composed of several compounds with the concentration ranging considerably with treatment and seasonality. An anomalous discharge, the influence of stormwater on the wastewater composition and the presence of recalcitrant compounds (linear alkylbenzene sulfonate surfactant homologs) in the effluent were further identified. The seasonal variations and abnormality in the composition of organic compounds in sewage indicated that the procedure that was employed can be useful in the identification of the pollution source and to enhance the effectiveness of WWTPs in designing preventive action to protect the equipment and preserve the environment.

  17. Anaerobic transformations of complex organic compounds in subsurface soils

    SciTech Connect

    Proctor, B.L. )

    1988-09-01

    This study was initiated following increased observations of man-made organic chemicals in groundwater. In the US, over 40% of the population depends on groundwater for drinking purposes. Soil is often the receptacle for organic chemicals, and there is a danger that they may reach the groundwater in a toxic form. Once contamination of the soil and vadose water has occurred, the compound may not be detected and/or degraded for decades. Limited, if any, information is available on the biotic-abiotic transformations of complex organic compounds in subsurface soils. The purpose of this study was to determine for each test compound (phenothiazine, 1-chloronaphthalene, 2-trifluoromethyl phenothiazine, 2-chloro-5 trifluoromethyl benzophenone and 2,2{prime},4,4{prime} tetrachlorobiphenyl) the following: (A) the soil sorption capacity for untreated subsurface soil, acid-treated, base-treated, mercuric chloride-treated, and calcium chloride treated subsurface soil; (B) transformation of the test compound in EPA soft water under anaerobic biotic and abiotic conditions; (C) transformation of the test compound in subsurface soils microcosms under anaerobic biotic and abiotic conditions; and (D) comparison of the results form the soil and water anaerobic biotic and abiotic studies.

  18. Preconcentration and detection of chlorinated organic compounds and benzene.

    PubMed

    Hobson, Stephen T; Cemalovic, Sabina; Patel, Sanjay V

    2012-03-01

    Remote and automated detection of organic compounds in subsurface aquifers is crucial to superfund monitoring and environmental remediation. Current monitoring techniques use expensive laboratory instruments and trained personnel. The use of a filled tubular preconcentrator combined with a chemicapacitive detector array presents an attractive option for the unattended monitoring of these compounds. Five preconcentrator materials were exposed to common target compounds of subsurface remediation projects (1,1,2-trichloroethane, trichloroethylene, t-1,2-dichloroethylene, benzene, and perchloroethylene). Rapid heating of the tube caused the collected, concentrated effluent to pass over the surface of a chemicapacitive detector array coated with four different sorbent polymers. A system containing a porous ladder polymer and the sensor array was subsequently used to sample the analytes injected onto sand in a laboratory test, simulating a subsurface environment. With extended collection times, effective detection limits of 5 ± 3 ppbV for 1,1,2-trichloroethane and 145 ± 60 ppbV for benzene were achieved. Effects of the preconcentrator material structure, the collection time, and sensor material on the system performance were observed. The resultant system presents a solution for remote, periodic monitoring of chlorinated organic compounds and other volatile organic compounds in a soil matrix.

  19. Analysis of Organic Compounds in Mars Analog Samples

    NASA Technical Reports Server (NTRS)

    Mahaffy, P. R.; Brinckerhoff, W. B.; Buch, A.; Cabane, M.; Coll, P.; Demick, J.; Glavin, D. P.

    2004-01-01

    The detailed characterization of organic compounds that might be preserved in rocks, ices, or sedimentary layers on Mars would be a significant step toward resolving the question of the habitability and potential for life on that planet. The fact that the Viking gas chromatograph mass spectrometer (GCMS) did not detect organic compounds should not discourage further investigations since (a) an oxidizing environment in the near surface fines analyzed by Viking is likely to have destroyed many reduced carbon species; (b) there are classes of refractory or partially oxidized species such as carboxylic acids that would not have been detected by the Viking GCMS; and (c) the Viking landing sites are not representative of Mars overall. These factors motivate the development of advanced in situ analytical protocols to carry out a comprehensive survey of organic compounds in martian regolith, ices, and rocks. We combine pyrolysis GCMS for analysis of volatile species, chemical derivatization for transformation of less volatile organics, and laser desorption mass spectrometry (LDMS) for analysis of elements and more refractory, higher-mass organics. To evaluate this approach and enable a comparison with other measurement techniques we analyze organics in Mars simulant samples.

  20. Method for predicting photocatalytic oxidation rates of organic compounds.

    PubMed

    Sattler, Melanie L; Liljestrand, Howard M

    2003-01-01

    In designing a photocatalytic oxidation (PCO) system for a given air pollution source, destruction rates for volatile organic compounds (VOCs) are required. The objective of this research was to develop a systematic method of predicting PCO rate constants by correlating rate constants with physical-chemical characteristics of compounds. Accordingly, reaction rate constants were determined for destruction of volatile organics over a titanium dioxide (TiO2) catalyst in a continuous mixed-batch reactor. It was found that PCO rate constants for alkanes and alkenes vary linearly with gas-phase ionization potential (IP) and with gas-phase hydroxyl radical reaction rate constant. The correlations allow rates of destruction of compounds not tested in this research to be predicted based on physical-chemical characteristics. PMID:12568248

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

    PubMed

    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. PMID:27266255

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

    PubMed

    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.

  3. Modeling emissions of volatile organic compounds from silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. The Survival of Meteorite Organic Compounds with Increasing Impact Pressure

    NASA Technical Reports Server (NTRS)

    Cooper, George; Horz, Friedrich; Oleary, Alanna; Chang, Sherwood; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The majority of carbonaceous meteorites studied today are thought to originate in the asteroid belt. Impacts among asteroidal objects generate heat and pressure that may have altered or destroyed pre-existing organic matter in both targets and projectiles to a greater or lesser degree depending upon impact velocities. Very little is known about the shock related chemical evolution of organic matter relevant to this stage of the cosmic history of biogenic elements and compounds. The present work continues our study of the effects of shock impacts on selected classes of organic compounds utilizing laboratory shock facilities. Our approach was to subject mixtures of organic compounds, embedded in a matrix of the Murchison meteorite, to a simulated hypervelocity impact. The molecular compositions of products were then analyzed to determine the degree of survival of the original compounds. Insofar as results associated with velocities < 8 km/sec may be relevant to impacts on planetary surfaces (e.g., oblique impacts, impacts on small outer planet satellites) or grain-grain collisions in the interstellar medium, then our experiments will be applicable to these environments as well.

  5. MICROBIAL VOLATILE ORGANIC COMPOUND EMISSION RATES AND EXPOSURE MODEL

    EPA Science Inventory

    This paper presents the results from a study that examined microbial volatile organic compound (MVOC) emissions from six fungi and one bacterial species (Streptomyces spp.) commonly found in indoor environments. Data are presented on peak emission rates from inoculated agar plate...

  6. MEASUREMENT OF ORGANIC COMPOUND EMISSIONS USING SMALL TEST CHAMBERS

    EPA Science Inventory

    Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The follow...

  7. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  8. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  9. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  10. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  11. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Modeling emissions of volatile organic compounds from silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile organic compounds (VOCs), necessary reactants for photochemical smog formation, are emitted from numerous sources. Limited available data suggest that dairy farms emit VOCs with cattle feed, primarily silage, being the primary source. Process-based models of VOC transfer within and from si...

  14. Measuring Emissions of Volatile Organic Compounds from Silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile organic compound (VOC) emissions are considered to be important precursors to smog and ozone production. An experimental protocol was developed to obtain undisturbed silage samples from silage storages. Samples were placed in a wind tunnel where temperature, humidity, and air flow were cont...

  15. Volatile organic compound emissions from dairy facilities in central California

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Energies of organic compounds. [Polyoxygenated methanes, ketals, orthoesters, cyclopropane derivatives

    SciTech Connect

    Wiberg, K. B.

    1980-07-01

    Automatic reaction calorimeters were developed. Enthalpies of hydration or hydrolysis were determined for polyoxygenated methanes, ketals, acetals, orthoesters, and alkenes. Trifluoroacetolysis of alkenes was carried out. Enthalpies of acetolysis and combustion of cyclopropane derivatives were also determined. Molecular mechanics calculations were carried out for ketones and ketals. Charge distribution in organic compounds were studied. 31 references. (DLC)

  17. LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

  18. Stripping volatile organic compounds and petroleum hydrocarbons from water

    SciTech Connect

    LaBranche, D.F.; Collins, M. R.

    1996-05-01

    Volatile organic compounds (VOCs) and petroleum products are ubiquitous groundwater contaminants. Petroleum products, for example, diesel fuel, contain a wide array of volatile, semivolatile, and large-chain hydrocarbon compounds. This research sought to determine whether air stripping can provide a site-specific treatment solution for petroleum-contaminated groundwaters and to document the abilities and limitations of tray-type (ShallowTray{sup TM}) air-stripping technology. Full factorial experimental trials were conducted to determine the influence of inlet water flow rate and temperature on trichloroethylene (TCE), perchloroethylene (PCE), and total petroleum hydrocarbon (TPH) removal. As expected, TPH removal controlled air stripper performance, and liquid temperature affected removal more than flow rate. The mass-transfer rate of TCE and PCE from water to air was controlled by the compound`s volatility, whereas the TPH mass-transfer rate was controlled by the compound`s concentration gradient. Results indicate that economical air stripping of VOC and TPH compounds can be achieved using low liquid flow rates (20 to 75 L/min), high air/water ratios (225 to 898), and medium liquid temperatures (16{degree}C to 28{degree}C) in tray-type air strippers. 19 refs., 7 figs., 6 tabs.

  19. Evaluation of Volatile Organic Compound Emissions from Megacities and Wildfires

    NASA Astrophysics Data System (ADS)

    Emmons, L. K.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Lamarque, J.; Wiedinmyer, C.; Mirage Science Team; Arctas Science Team

    2011-12-01

    Volatile organic compounds (VOCs) play a critical role in determining air quality through their impact on ozone production and other pollutants. Tropospheric chemistry models use a variety of treatments for the lumping of VOCs in their chemical mechanisms, as a compromise between detailed treatment and computational speed. However, emission inventories are frequently provided for only total VOCs with little or no information on how to split the emissions among the model species, introducing additional uncertainty to the model simulations. Global model simulations using the Model for Ozone and Related Chemical Tracers (MOZART-4) and several different emission inventories are evaluated through detailed comparison to aircraft and surface observations. In particular, correlations between measured VOCs and CO are used to test the emission inventory emission ratios of the modeled VOC species. For example, megacity VOC emissions will be evaluated with surface measurements in Mumbai, Shanghai and Tokyo, as well as aircraft measurements from the NSF/MIRAGE experiment downwind of Mexico City. Wildfire emissions in Siberia, Canada and California will be evaluated using airborne observations of the NASA/ARCTAS experiment.

  20. Predicting carcinogenicity of organic compounds based on CPDB.

    PubMed

    Wu, Xiuchao; Zhang, Qingzhu; Wang, Hui; Hu, Jingtian

    2015-11-01

    Cancer is a major killer of human health and predictions for the carcinogenicity of chemicals are of great importance. In this article, predictive models for the carcinogenicity of organic compounds using QSAR methods for rats and mice were developed based on the data from CPDB. The models was developed based on the data of specific target site liver and classified according to sex of rats and mice. Meanwhile, models were also classified according to whether there is a ring in the molecular structure in order to reduce the diversity of molecular structure. Therefore, eight local models were developed in the final. Taking into account the complexity of carcinogenesis and in order to obtain as much information, DRAGON descriptors were selected as the variables used to develop models. Fitting ability, robustness and predictive power of the models were assessed according to the OECD principles. The external predictive coefficients for validation sets of each model were in the range of 0.711-0.906, and for the whole data in each model were all greater than 0.8, which represents that all models have good predictivity. In order to study the mechanism of carcinogenesis, standardized regression coefficients were calculated for all predictor variables. In addition, the effect of animal sex on carcinogenesis was compared and a trend that female showed stronger tolerance for cancerogen than male in both species was appeared. PMID:26070146

  1. Source identification of volatile organic compounds in Houston, Texas.

    PubMed

    Zhao, Weixiang; Hopke, Philip K; Karl, Thomas

    2004-03-01

    The complexity of the volatile organic compound (VOC) mixture in the Houston area makes studies of the air quality in that area very challenging. In this paper, a novel factor analysis model, where the normal chemical mass balance model was augmented by a parallel equation that accounted for wind speed and direction, temperature, and weekend/weekday effects, was fitted with a multilinear engine (ME) to provide identification and apportionment of the VOC sources at the La Porte Municipal Airport site in Houston during the Texas Air Quality Study (TexAQS) 2000. The analysis determined the profiles and contributions of nine sources and the corresponding wind speed, wind direction, temperature, and weekend factors. The reasonableness of these results not only suggests the high resolving power of the expanded factor analysis model for source apportionment but also provides the novel and effective auxiliary information for more specific source identification. In addition, a new approach to estimate the measurement uncertainty and the details of determining the source number and dealing with missing values are also presented as important parts of the data analysis process. This study demonstrates the feasibility of the expanded model to identify sources in complex VOC systems and extract useful information for locating VOC emitters and controlling their emissions in the Houston area.

  2. Fate of alkylphenolic compounds during activated sludge treatment: impact of loading and organic composition.

    PubMed

    McAdam, Ewan J; Bagnall, John P; Soares, Ana; Koh, Yoong K K; Chiu, Tze Y; Scrimshaw, Mark D; Lester, John N; Cartmell, Elise

    2011-01-01

    The impact of loading and organic composition on the fate of alkylphenolic compounds in the activated sludge plant (ASP) has been studied. Three ASP designs comprising carbonaceous, carbonaceous/nitrification, and carbonaceous/nitrification/denitrification treatment were examined to demonstrate the impact of increasing levels of process complexity and to incorporate a spectrum of loading conditions. Based on mass balance, overall biodegradation efficiencies for nonylphenol ethoxylates (NPEOs), short chain carboxylates (NP(1-3)EC) and nonylphenol (NP) were 37%, 59%, and 27% for the carbonaceous, carbonaceous/nitrification, and carbonaceous/nitrification/denitrification ASP, respectively. The presence of a rich community of ammonia oxidizing bacteria does not necessarily facilitate effective alkylphenolic compound degradation. However, a clear correlation between alkylphenolic compound loading and long chain ethoxylate compound biodegradation was determined at the three ASPs, indicating that at higher initial alkylphenolic compound concentrations (or load), greater ethoxylate biotransformation can occur. In addition, the impact of settled sewage organic composition on alkylphenolic compound removal was evaluated. A correlation between the ratio of chemical oxygen demand (COD) to alkylphenolic compound concentration and biomass activity was determined, demonstrating the inhibiting effect of bulk organic matter on alkylphenol polyethoxylate transformation activity. At all three ASPs the biodegradation pathway proposed involves the preferential biodegradation of the amphiphilic ethoxylated compounds, after which the preferential attack of the lipophilic akylphenol moiety occurs. The extent of ethoxylate biodegradation is driven by the initial alkylphenolic compound concentration and the proportion of COD constituted by the alkylphenol polyethoxylates (APEOs) and their metabolites relative to the bulk organic concentration of the sewage composed of proteins, acids, fats

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways. We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds. Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult. The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and

  4. (Semi)volatile Organic Compounds and Microbiological Entities in Snow during OASIS Barrow 2009

    NASA Astrophysics Data System (ADS)

    Kos, G.; Nafissa, A.; Lutchman, D.; Mortazavi, R.; Ariya, P.

    2009-12-01

    Snow has recently been shown to be an active medium for the deposition of (semi-)volatile (bio)organic compounds. We collected surface snow samples during the OASIS Barrow campaign in March 2009 for analysis of semi-volatile organic compounds using solid phase microextraction and gas chromatography with mass spectrometric detection (SPME-GC/MS). Additional grab samples were taken for analysis of non-methane hydrocarbons in air. Moreover we analyzed for microbial species in air and snow. Identifed organic compounds covered a wide range of functionalities and molecular weights, including oxygenated reactive speces such as aldehydes (e.g., hexanal to decanal), alcohols (e.g., hexanol, octanol) and aromatic species (e.g., methyl- and ethylbenzenes). Quantification data for selected aromatic species are presented with concentrations in the upper ng/L range. We will present our preliminary data on microbiological species, and will discuss the potential implications of the results for organic snow chemistry.

  5. Aerobic biodegradation of organic compounds in hydraulic fracturing fluids.

    PubMed

    Kekacs, Daniel; Drollette, Brian D; Brooker, Michael; Plata, Desiree L; Mouser, Paula J

    2015-07-01

    Little is known of the attenuation of chemical mixtures created for hydraulic fracturing within the natural environment. A synthetic hydraulic fracturing fluid was developed from disclosed industry formulas and produced for laboratory experiments using commercial additives in use by Marcellus shale field crews. The experiments employed an internationally accepted standard method (OECD 301A) to evaluate aerobic biodegradation potential of the fluid mixture by monitoring the removal of dissolved organic carbon (DOC) from an aqueous solution by activated sludge and lake water microbial consortia for two substrate concentrations and four salinities. Microbial degradation removed from 57 % to more than 90 % of added DOC within 6.5 days, with higher removal efficiency at more dilute concentrations and little difference in overall removal extent between sludge and lake microbe treatments. The alcohols isopropanol and octanol were degraded to levels below detection limits while the solvent acetone accumulated in biological treatments through time. Salinity concentrations of 40 g/L or more completely inhibited degradation during the first 6.5 days of incubation with the synthetic hydraulic fracturing fluid even though communities were pre-acclimated to salt. Initially diverse microbial communities became dominated by 16S rRNA sequences affiliated with Pseudomonas and other Pseudomonadaceae after incubation with the synthetic fracturing fluid, taxa which may be involved in acetone production. These data expand our understanding of constraints on the biodegradation potential of organic compounds in hydraulic fracturing fluids under aerobic conditions in the event that they are accidentally released to surface waters and shallow soils.

  6. Aerobic biodegradation of organic compounds in hydraulic fracturing fluids.

    PubMed

    Kekacs, Daniel; Drollette, Brian D; Brooker, Michael; Plata, Desiree L; Mouser, Paula J

    2015-07-01

    Little is known of the attenuation of chemical mixtures created for hydraulic fracturing within the natural environment. A synthetic hydraulic fracturing fluid was developed from disclosed industry formulas and produced for laboratory experiments using commercial additives in use by Marcellus shale field crews. The experiments employed an internationally accepted standard method (OECD 301A) to evaluate aerobic biodegradation potential of the fluid mixture by monitoring the removal of dissolved organic carbon (DOC) from an aqueous solution by activated sludge and lake water microbial consortia for two substrate concentrations and four salinities. Microbial degradation removed from 57 % to more than 90 % of added DOC within 6.5 days, with higher removal efficiency at more dilute concentrations and little difference in overall removal extent between sludge and lake microbe treatments. The alcohols isopropanol and octanol were degraded to levels below detection limits while the solvent acetone accumulated in biological treatments through time. Salinity concentrations of 40 g/L or more completely inhibited degradation during the first 6.5 days of incubation with the synthetic hydraulic fracturing fluid even though communities were pre-acclimated to salt. Initially diverse microbial communities became dominated by 16S rRNA sequences affiliated with Pseudomonas and other Pseudomonadaceae after incubation with the synthetic fracturing fluid, taxa which may be involved in acetone production. These data expand our understanding of constraints on the biodegradation potential of organic compounds in hydraulic fracturing fluids under aerobic conditions in the event that they are accidentally released to surface waters and shallow soils. PMID:26037076

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

    SciTech Connect

    Michalski, Casey C.; DiSalvo, Rick; Boylan, John

    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)

  8. Mobilization and Transport of Organic Compounds from Reservoir Rock and Caprock in Geological Carbon Sequestration Sites

    SciTech Connect

    Zhong, Lirong; Cantrell, Kirk J.; Mitroshkov, Alexandre V.; Shewell, Jesse L.

    2014-05-06

    Supercritical CO2 (scCO2) is an excellent solvent for organic compounds, including benzene, toluene, ethyl-benzene, and xylene (BTEX), phenols, and polycyclic aromatic hydrocarbons (PAHs). Monitoring results from geological carbon sequestration (GCS) field tests has shown that organic compounds are mobilized following CO2 injection. Such results have raised concerns regarding the potential for groundwater contamination by toxic organic compounds mobilized during GCS. Knowledge of the mobilization mechanism of organic compounds and their transport and fate in the subsurface is essential for assessing risks associated with GCS. Extraction tests using scCO2 and methylene chloride (CH2Cl2) were conducted to study the mobilization of volatile organic compounds (VOCs, including BTEX), the PAH naphthalene, and n-alkanes (n-C20 – n-C30) by scCO2 from representative reservoir rock and caprock obtained from depleted oil reservoirs and coal from an enhanced coal-bed methane recovery site. More VOCs and naphthalene were extractable by scCO2 compared to the CH2Cl2 extractions, while scCO2 extractable alkane concentrations were much lower than concentrations extractable by CH2Cl2. In addition, dry scCO2 was found to extract more VOCs than water saturated scCO2, but water saturated scCO2 mobilized more naphthalene than dry scCO2. In sand column experiments, moisture content was found to have an important influence on the transport of the organic compounds. In dry sand columns the majority of the compounds were retained in the column except benzene and toluene. In wet sand columns the mobility of the BTEX was much higher than that of naphthalene. Based upon results determined for the reservoir rock, caprock, and coal samples studied here, the risk to aquifers from contamination by organic compounds appears to be relatively low; however, further work is necessary to fully evaluate risks from depleted oil reservoirs.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Analysis of organic compounds in returned comet nucleus samples

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.

    1989-01-01

    Techniques for analysis of organic compounds in returned comet nucleus samples are described. Interstellar, chondritic and transitional organic components are discussed. Appropriate sampling procedures will be essential to the success of these analyses. It will be necessary to return samples that represent all the various regimes found in the nucleus, e.g., a complete core, volatile components (deep interior), and crustal components (surface minerals, rocks, processed organics such as macromolecular carbon and polymers). Furthermore, sampling, storage, return, and distribution of samples must be done under conditions that preclude contamination of the samples by terrestrial matter.

  11. Determination of fluorine in organic compounds: Microcombustion method

    USGS Publications Warehouse

    Clark, H.S.

    1951-01-01

    A reliable and widely applicable means of determining fluorine in organic compounds has long been needed. Increased interest in this field of research in recent years has intensified the need. Fluorine in organic combinations may be determined by combustion at 900?? C. in a quartz tube with a platinum catalyst, followed by an acid-base titration of the combustion products. Certain necessary precautions and known limitations are discussed in some detail. Milligram samples suffice, and the accuracy of the method is about that usually associated with the other halogen determinations. Use of this method has facilitated the work upon organic fluorine compounds in this laboratory and it should prove to be equally valuable to others.

  12. Absorption and excretion of organic compounds of copper by sheep.

    PubMed

    Mahmoud, O M; Ford, E J

    1983-10-01

    When sheep are injected subcutaneously with copper calcium edetate or copper oxyquinoline sulphonate there is a rapid increase in the concentration of copper in whole blood, serum and urine within the first 24 h. When sheep are injected with copper methionate the concentration of copper in whole blood and serum rises slowly over a period of about 10 days and there is no detectable increase in urinary copper. After the injection of each of the three compounds, there was a steady increase in the caeruloplasmin activity in serum over a period of 10 to 20 days, followed by a slow fall to pre-injection activity by 40 days. There was a marked increase in the beta-globulin fraction of serum 9 days after the injection of copper methionate but not after the other 2 compounds and the amounts of 2 copper containing proteins in liver were greater 60 days after the injection of copper methionate than after the injection of the other two compounds. The copper content of the 3 organic compounds is absorbed and excreted at different rates by sheep. The amounts of copper-containing protein produced in the liver also differ according to the organic component of the compound injected. The results suggest that the lower toxicity of copper injected as methionate compared with that injected as copper calcium edetate or copper oxyquinoline sulphonate is due to the slower absorption and transport of the copper to the liver and kidney.

  13. Biodiversity of volatile organic compounds from five French ferns.

    PubMed

    Fons, Françoise; Froissard, Didier; Bessière, Jean-Marie; Buatois, Bruno; Rapior, Sylvie

    2010-10-01

    Five French ferns belonging to different families were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Fifty-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including monoterpenes, sesquiterpenes and carotenoid-type compounds were identified. The main volatile compound of Adiantum capillus-veneris L. (Pteridaceae) was (E)-2-decenal with a plastic or "stink bug" odor. The volatile profiles of Athyrium filix-femina (L.) Roth (Woodsiaceae) and Blechnum spicant (L.) Roth (Blechnaceae) showed similarities, with small amounts of isoprenoids and the same main volatile compounds, i.e., 2-phenylethanal (odor of lilac and hyacinth) and 1-octen-3-ol (mushroom-like odor). The main volatile compound of Dryopteris filix-mas (L.) Schott (Dryopteridaceae) was (E)-nerolidol with a woody or fresh bark note. Polyketides, as acylfilicinic acids, were mainly identified in this fern. Oreopteris limbosperma (Bellardi ex. All.) J. Holub (Thelypteridaceae), well-known for its lemon smell, contained the highest biodiversity of VOC. Eighty percent of the volatiles was issued from the terpenic pathway. The main volatiles were (E)-nerolidol, alpha-terpineol, beta-caryophyllene and other minor monoterpenes (for example, linalool, pinenes, limonene, and gamma-terpinen-7-al). It was also the fern with the highest number of carotenoid-type derivatives, which were identified in large amounts. Our results were of great interest underlying new industrial valorisation for ferns based on their broad spectrum of volatiles. PMID:21121267

  14. Measurements of halogenated organic compounds near the tropical tropopause

    NASA Technical Reports Server (NTRS)

    Schauffler, S. M.; Heidt, L. E.; Pollock, W. H.; Gilpin, T. M.; Vedder, J. F.; Solomon, S.; Lueb, R. A.; Atlas, E. L.

    1993-01-01

    The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8 deg N and 25.3 deg N during AASE 2. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 +/- 0.06 ppbv and 21.1 +/- 0.8 pptv, respectively. CH3Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl3F) and CFC 12 (CCl2F2) accounting for 22.6% and 28.2%, respectively, with the remaining 34.1% primarily from CCl4, CH3CCl3, and CFC 113 (CCl2FCClF2). CH3Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude mid-troposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl3, CH2Cl2, CH2Br2, and CH3CCl3. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere.

  15. Measurements of Halogenated Organic Compounds near the Tropical Tropopause

    NASA Technical Reports Server (NTRS)

    Schauffler, S. M.; Heidt, L. E.; Pollock, W. H.; Gilpin, T. M.; Vedder, J. F.; Solomon, S.; Leub, R. A.; Atlas, E. L.

    1993-01-01

    The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8 deg N and 25.3 deg N during AASE 2. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 +/- 0.06 ppbv and 21.1 +/- 0.8 pptv, respectively. CH3Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl3F) and CFC 12 (CCl2F2) accounting for 22.6% and 28.2%, respectively, with the remaining 34.1% primarily from CCl4, CH3CCl3, and CFC 113 (CCl2FCClF2). CH3Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude midtroposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl3, CH2Cl2, CH2Br2, and CH3CCl3. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere.

  16. Temperature sensitivity of organic compound destruction in SCWO process.

    PubMed

    Tan, Yaqin; Shen, Zhemin; Guo, Weimin; Ouyang, Chuang; Jia, Jinping; Jiang, Weili; Zhou, Haiyun

    2014-03-01

    To study the temperature sensitivity of the destruction of organic compounds in supercritical water oxidation process (SCWO), oxidation effects of twelve chemicals in supercritical water were investigated. The SCWO reaction rates of different compounds improved to varying degrees with the increase of temperature, so the highest slope of the temperature-effect curve (imax) was defined as the maximum ratio of removal ratio to working temperature. It is an important index to stand for the temperature sensitivity effect in SCWO. It was proven that the higher imax is, the more significant the effect of temperature on the SCWO effect is. Since the high-temperature area of SCWO equipment is subject to considerable damage from fatigue, the temperature is of great significance in SCWO equipment operation. Generally, most compounds (imax > 0.25) can be completely oxidized when the reactor temperature reaches 500°C. However, some compounds (imax > 0.25) need a higher temperature for complete oxidation, up to 560°C. To analyze the correlation coefficients between imax and various molecular descriptors, a quantum chemical method was used in this study. The structures of the twelve organic compounds were optimized by the Density Functional Theory B3LYP/6-311G method, as well as their quantum properties. It was shown that six molecular descriptors were negatively correlated to imax while other three descriptors were positively correlated to imax. Among them, dipole moment had the greatest effect on the oxidation thermodynamics of the twelve organic compounds. Once a correlation between molecular descriptors and imax is established, SCWO can be run at an appropriate temperature according to molecular structure.

  17. Temperature sensitivity of organic compound destruction in SCWO process.

    PubMed

    Tan, Yaqin; Shen, Zhemin; Guo, Weimin; Ouyang, Chuang; Jia, Jinping; Jiang, Weili; Zhou, Haiyun

    2014-03-01

    To study the temperature sensitivity of the destruction of organic compounds in supercritical water oxidation process (SCWO), oxidation effects of twelve chemicals in supercritical water were investigated. The SCWO reaction rates of different compounds improved to varying degrees with the increase of temperature, so the highest slope of the temperature-effect curve (imax) was defined as the maximum ratio of removal ratio to working temperature. It is an important index to stand for the temperature sensitivity effect in SCWO. It was proven that the higher imax is, the more significant the effect of temperature on the SCWO effect is. Since the high-temperature area of SCWO equipment is subject to considerable damage from fatigue, the temperature is of great significance in SCWO equipment operation. Generally, most compounds (imax > 0.25) can be completely oxidized when the reactor temperature reaches 500°C. However, some compounds (imax > 0.25) need a higher temperature for complete oxidation, up to 560°C. To analyze the correlation coefficients between imax and various molecular descriptors, a quantum chemical method was used in this study. The structures of the twelve organic compounds were optimized by the Density Functional Theory B3LYP/6-311G method, as well as their quantum properties. It was shown that six molecular descriptors were negatively correlated to imax while other three descriptors were positively correlated to imax. Among them, dipole moment had the greatest effect on the oxidation thermodynamics of the twelve organic compounds. Once a correlation between molecular descriptors and imax is established, SCWO can be run at an appropriate temperature according to molecular structure. PMID:25079262

  18. Anthropogenic and biogenic organic compounds in summertime fine aerosols (PM2.5) in Beijing, China

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Kawamura, Kimitaka; Chen, Jing; Ho, Kinfai; Lee, Shuncheng; Gao, Yuan; Cui, Long; Wang, Tieguan; Fu, Pingqing

    2016-01-01

    Ambient fine aerosol samples (PM2.5) were collected at an urban site (PKU) in Beijing and its upwind suburban site (Yufa) during the CAREBEIJING-2007 field campaign. Organic molecular compositions of the PM2.5 samples were studied for seven organic compound classes (sugars, lignin/resin acids, hydroxy-/polyacids, aromatic acids, biogenic SOA tracers, fatty acids and phthalates) using capillary GC/MS to better understand the characteristics and sources of organic aerosol pollution in Beijing. More than 60 individual organic species were detected in PM2.5 and were grouped into different compound classes based on their functional groups. Concentrations of total quantified organics at Yufa (469-1410 ng m-3, average 1050 ng m-3) were slightly higher than those at PKU (523-1390 ng m-3, 900 ng m-3). At both sites, phthalates were found as the most abundant compound class. Using a tracer-based method, the contributions of the biogenic secondary organic carbon (SOC) to organic carbon (OC) were 3.1% at PKU and 5.5% at Yufa, among which isoprene-SOC was the dominant contributor. In addition, most of the measured organic compounds were higher at Yufa than those at PKU, indicating a more serious pollution in its upwind region than in urban Beijing.

  19. Estimation of Henry's Law Constant for a Diverse Set of Organic Compounds from Molecular Structure

    EPA Science Inventory

    The SPARC (SPARC Performs Automated Reasoning in Chemistry) vapor pressure and activity coefficient models were coupled to estimate Henry’s Law Constant (HLC) in water and in hexadecane for a wide range of non-polar and polar organic compounds without modification or additional p...

  20. Group extraction of organic compounds present in liquid samples

    NASA Technical Reports Server (NTRS)

    Jahnsen, Vilhelm J. (Inventor)

    1976-01-01

    An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

  1. PILOT-SCALE STUDIES ON THE EFFECT OF BROMINE ADDITION ON THE EMISSIONS OF CHLORINATED ORGANIC COMBUSTION BY-PRODUCTS

    EPA Science Inventory

    The addition of brominated organic compounds to the feed of a pilot-scale incinerator burning chlorinated waste has been found previously, under some circumstances, to enhance emissions of volatile and semivolatile organic chlorinated products of incomplete combustion (PiCs) incl...

  2. Response of Dissolved Organic Matter to Warming and Nitrogen Addition

    NASA Astrophysics Data System (ADS)

    Choi, J. H.; Nguyen, H.

    2014-12-01

    Dissolved Organic Matter (DOM) is a ubiquitous mixture of soluble organic components. Since DOM is produced from the terrestrial leachate of various soil types, soil may influence the chemistry and biology of freshwater through the input of leachate and run-off. The increased temperature by climate change could dramatically change the DOM characteristics of soils through enhanced decomposition rate and losses of carbon from soil organic matter. In addition, the increase in the N-deposition affects DOM leaching from soils by changing the carbon cycling and decomposition rate of soil decay. In this study, we conducted growth chamber experiments using two types of soil (wetland and forest) under the conditions of temperature increase and N-deposition in order to investigate how warming and nitrogen addition influence the characteristics of the DOM leaching from different soil types. This leachate controls the quantity and quality of DOM in surface water systems. After 10 months of incubation, the dissolved organic carbon (DOC) concentrations decreased for almost samples in the range of 7.6 to 87.3% (ANOVA, p<0.05). The specific UV absorption (SUVA) values also decreased for almost samples after the first 3 months and then increased gradually afterward in range of 3.3 to 108.4%. Both time and the interaction between time and the temperature had the statistically significant effects on the SUVA values (MANOVA, p<0.05). Humification index (HIX) showed the significant increase trends during the duration of incubation and temperature for almost the samples (ANOVA, p<0.05). Higher decreases in the DOC values and increases in HIX were observed at higher temperatures, whereas the opposite trend was observed for samples with N-addition. The PARAFAC results showed that three fluorescence components: terrestrial humic (C1), microbial humic-like (C2), and protein-like (C3), constituted the fluorescence matrices of soil samples. During the experiment, labile DOM from the soils was

  3. Hazardous organic compounds in biogas plant end products--soil burden and risk to food safety.

    PubMed

    Suominen, K; Verta, M; Marttinen, S

    2014-09-01

    The end products (digestate, solid fraction of the digestate, liquid fraction of the digestate) of ten biogas production lines in Finland were analyzed for ten hazardous organic compounds or compound groups: polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCB(7)), polyaromatic hydrocarbons (PAH(16)), bis-(2-ethylhexyl) phthalate (DEHP), perfluorinated alkyl compounds (PFCs), linear alkylbenzene sulfonates (LASs), nonylphenols and nonylphenol ethoxylates (NP+NPEOs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Biogas plant feedstocks were divided into six groups: municipal sewage sludge, municipal biowaste, fat, food industry by-products, animal manure and others (consisting of milling by-products (husk) and raw former foodstuffs of animal origin from the retail trade). There was no clear connection between the origin of the feedstocks of a plant and the concentrations of hazardous organic compounds in the digestate. For PCDD/Fs and for DEHP, the median soil burden of the compound after a single addition of digestate was similar to the annual atmospheric deposition of the compound or compound group in Finland or other Nordic countries. For PFCs, the median soil burden was somewhat lower than the atmospheric deposition in Finland or Sweden. For NP+NPEOs, the soil burden was somewhat higher than the atmospheric deposition in Denmark. The median soil burden of PBDEs was 400 to 1000 times higher than the PBDE air deposition in Finland or in Sweden. With PBDEs, PFCs and HBCD, the impact of the use of end products should be a focus of further research. Highly persistent compounds, such as PBDE- and PFC-compounds may accumulate in agricultural soil after repeated use of organic fertilizers containing these compounds. For other compounds included in this study, agricultural use of biogas plant end products is unlikely to cause risk to food safety in Finland.

  4. The effect of silane addition timing on mixing processability and properties of silica reinforced rubber compound

    NASA Astrophysics Data System (ADS)

    Jeong, Hee-Hoon; Jin, Hyun-Ho; Ha, Sung-Ho; Jang, Suk-Hee; Kang, Yong-Gu; Han, Min-Hyun

    2016-03-01

    A series of experiments were performed to determine an optimum balance between processability and performance of a highly loaded silica compound. The experiments evaluated 4 different silane injection times. All mixing related to silane addition was conducted with a scaled up "Tandem" mixer line. With exception to silane addition timing, almost all operating conditions were controlled between experimental features. It was found that when the silane addition was introduced earlier in the mixing cycle both the reaction was more complete and the bound rubber content was higher. But processability indicators such as sheet forming and Mooney plasticity were negatively impacted. On the other hand, as silane injection was delayed to later in the mixing process the filler dispersion and good sheet forming was improved. However both the bound rubber content and Silane reaction completion were decreased. With the changes in silane addition time, the processability and properties of a silica compound can be controlled.

  5. A Review of the Tissue Residue Approach for Organic and Organometallic Compounds in Aquatic Organisms

    EPA Science Inventory

    This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (tin, mercury, and lead). Specific emphasis was placed on evaluating key factors that influence interpretation of critical body resid...

  6. Preliminary study on the occurrence of brominated organic compounds in Dutch marine organisms.

    PubMed

    Kotterman, Michiel; van der Veen, Ike; van Hesselingen, Judith; Leonards, Pim; Osinga, Ronald; de Boer, Jacob

    2003-07-01

    The extracts of three marine organisms; the ascidian Ciona intestinalis, the brown seaweed Sargassum muticum and the sponge Halichondria panicea, all elicited a number of brominated compounds, some of which were tentatively identified. Tribromophenol was observed in all species. This compound, also industrially produced as flame retardant and fungicide, was likely due to endogenous production. PMID:12919829

  7. Identification and Quantification of Volatile Organic Compounds at a Dairy

    NASA Astrophysics Data System (ADS)

    Filipy, J.; Mount, G.; Westberg, H.; Rumburg, B.

    2003-12-01

    Livestock operations in the United States are an escalating environmental concern. The increasing density of livestock within a farm results in an increased emission of odorous gases, which have gained considerable attention by the public in recent years (National Research Council (NRC), 2002). Odorous compounds such as ammonia (NH3), volatile organic compounds (VOC's), and hydrogen sulfide (H2S) were reported to have a major effect on the quality of life of local residents living near livestock facilities (NRC, 2002). There has been little data collected related to identification and quantification of gaseous compounds collected from open stall dairy operations in the United States. The research to be presented identifies and quantifies VOCs produced from a dairy operation that contribute to odor and other air quality problems. Many different VOCs were identified in the air downwind of an open lactating cow stall area and near a waste lagoon at the Washington State University dairy using Gas Chromatography Mass Spectroscopy (GC-MS) analysis techniques. Identified compounds were very diverse and included many alcohols, aldehydes, amines, aromatics, esters, ethers, a fixed gas, halogenated hydrocarbons, hydrocarbons, ketones, other nitrogen containing compounds, sulfur containing compounds, and terpenes. The VOCs directly associated with cattle waste were dependent on ambient temperature, with the highest emissions produced during the summer months. Low to moderate wind speeds were ideal for VOC collection. Concentrations of quantified compounds were mostly below odor detection thresholds found in the literature, however the combined odor magnitude of the large number of compounds detected was most likely above any minimum detection threshold.

  8. Chemical compounds to be used as solid carriers for fuel additives

    SciTech Connect

    Santambrogio, A.; Mattei, L.

    1987-09-08

    This patent describes compositions of dosing additives to fuel for internal combustion engines, comprising (1) solid carrier chemical compounds, which have a melting point between 70/sup 0/C and 130/sup 0/C, are soluble in hydrocarbons and are selected from the group consisting of alkyl-substituted phenols, aromatic carbonates, alkyl-substituted pyrocatechols, and polymers of alkyl-substituted 1,2-dihydroquinoline; and (2) additives for fuel for internal combustion engines which are liquid at room temperature.

  9. Thermal engine driven heat pump for recovery of volatile organic compounds

    DOEpatents

    Drake, Richard L.

    1991-01-01

    The present invention relates to a method and apparatus for separating volatile organic compounds from a stream of process gas. An internal combustion engine drives a plurality of refrigeration systems, an electrical generator and an air compressor. The exhaust of the internal combustion engine drives an inert gas subsystem and a heater for the gas. A water jacket captures waste heat from the internal combustion engine and drives a second heater for the gas and possibly an additional refrigeration system for the supply of chilled water. The refrigeration systems mechanically driven by the internal combustion engine effect the precipitation of volatile organic compounds from the stream of gas.

  10. Partitioning of Organic Contaminants and Tracer Compounds in a CO2-Brine System at High Salinities

    NASA Astrophysics Data System (ADS)

    Thomas, B.; Kharaka, Y. K.; Rosenbauer, R. J.; Janesko, D.; Trutna, J.

    2011-12-01

    Nonionic chemical species including gases and organic compounds partition between the fluid CO2 phase and the aqueous phase in geologic carbon sequestration systems. The injection and migration of CO2 in geologic carbon sequestration systems covers a wide range of pressure and temperature, so it is important to understand the partitioning of these compounds at various P-T conditions and salinities. Geochemical data is particularly lacking for the partitioning of organic contaminant compounds and tracer compounds between highly saline brines and CO2. Most groundwater is relatively low in organic contaminants; however, groundwater associated with hydrocarbon migration pathways, enhanced oil recovery (EOR), and hydrocarbon storage or extraction can contain high concentrations of known organic contaminants. CO2 injection in these systems may therefore be more likely to result in partitioning of contaminants into the CO2 phase that could, upon migration, represent an important risk to groundwater resources. We present the experimental apparatus and determination of partition coefficients between brine and CO2 for a suite of compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and low molecular weight polynuclear aromatic hydrocarbons (PAHs). In addition, partition coefficients are determined for the important gas phase tracer compounds: SF6 and Krypton covering a P-T envelope consistent with CO2 injection and plume migration to the near surface.

  11. Novel synthetic organic compounds inspired from antifeedant marine alkaloids as potent bacterial biofilm inhibitors.

    PubMed

    Rane, Rajesh A; Karpoormath, Rajshekhar; Naphade, Shital S; Bangalore, Pavankumar; Shaikh, Mahamadhanif; Hampannavar, Girish

    2015-08-01

    In this paper, we have reported seventeen novel synthetic organic compounds derived from marine bromopyrrole alkaloids, exhibiting potential inhibition of biofilm produced by Gram-positive bacteria. Compound 5f with minimumbiofilm inhibitory concentration(MBIC) of 0.39, 0.78 and 3.125 μg/mL against MSSA, MRSA and SE respectively, emerged as promising anti-biofilm lead compounds. In addition, compounds 5b, 5c, 5d, 5e, 5f, 5h, 5i and 5j revealed equal potency as that of the standard drug Vancomycin (MBIC = 3.125 μg/mL) against Streptococcus epidermidis. Notably, most of the synthesized compounds displayed better potency than Vancomycin indicating their potential as inhibitors of bacterial biofilm. The cell viability assay for the most active hybrid confirms its anti-virulence properties which need to be further researched.

  12. Dielectric Barrier Discharge Ionization in Characterization of Organic Compounds Separated on Thin-Layer Chromatography Plates

    PubMed Central

    Cegłowski, Michał; Smoluch, Marek; Babij, Michał; Gotszalk, Teodor; Silberring, Jerzy; Schroeder, Grzegorz

    2014-01-01

    A new method for on-spot detection and characterization of organic compounds resolved on thin layer chromatography (TLC) plates has been proposed. This method combines TLC with dielectric barrier discharge ionization (DBDI), which produces stable low-temperature plasma. At first, the compounds were separated on TLC plates and then their mass spectra were directly obtained with no additional sample preparation. To obtain good quality spectra the center of a particular TLC spot was heated from the bottom to increase volatility of the compound. MS/MS analyses were also performed to additionally characterize all analytes. The detection limit of proposed method was estimated to be 100 ng/spot of compound. PMID:25170762

  13. Bibliography on contaminants and solubility of organic compounds in oxygen

    NASA Technical Reports Server (NTRS)

    Ordin, P. M. (Compiler)

    1975-01-01

    A compilation of a number of document citations is presented which contains information on contaminants in oxygen. Topics covered include contaminants and solubility of organic compounds in oxygen, reaction characteristics of organic compounds with oxygen, and sampling and detection limits of impurities. Each citation in the data bank contains many items of information about the document. Some of the items are title, author, abstract, corporate source, description of figures pertinent to hazards or safety, key references, and descriptors (keywords) by which the document can be retrieved. Each citation includes an evaluation of the technical contents as to being good/excellent, acceptable, or poor. The descriptors used to define the contents of the documents and subsequently used in the computerized search operations were developed for the cryogenic fluid safety by experts in the cryogenics field.

  14. Destruction of organic compounds in water using supported photocatalysts

    SciTech Connect

    Zhang, Y.; Crittenden, J.C.; Hand, D.W.; Perram, D.L.

    1996-05-01

    Photocatalytic destruction of organic compounds in water is investigated using tanning lamps and fixed-bed photoreactors. Platinized titanium dioxide (Pt-TiO{sub 2}) supported on silica gel is used as a photocatalyst. Complete mineralization of influent concentrations of 4.98 mg/L tetrachloroethylene and 2.35 mg/L p-dichlorobenzene requires a reactor residence time less than 1.3 minutes. While for influent concentrations of 3.58 mg/L 2-chlorobiphenyl, 2.50 mg/L methyl ethyl ketone and 0.49 mg/L carbon tetrachloride, complete mineralization requires reactor residence times of 1.6, 10.5, and 16.8 minutes, respectively. A reactor model is developed using Langmuir-Hinshelwood kinetics and the model parameters are determined using a reference compound, trichloroethylene. Based on the results of experiments with trichloroethylene, the model predicts the mineralization of the aforementioned compounds from ultraviolet (UV) irradiance, influent concentration, hydroxyl radical rate constants, and the known physical properties of the compounds. The model is also able to predict organic destruction using solar insolation (which has a different spectral distribution from the tanning lamps) based on the UV absorption characteristics of titanium dioxide.

  15. Microbial desulfurization of organic sulfur compounds in petroleum.

    PubMed

    Ohshiro, T; Izumi, Y

    1999-01-01

    Sulfur removal from petroleum is important from the standpoint of the global environment because the combustion of sulfur compounds leads to the production of sulfur oxides, which are the source of acid rain. As the regulations for sulfur in fuels become more stringent, the existing chemical desulfurizations are coming inadequate for the "deeper desulfurization" to produce lower-sulfur fuels without new and innovative processes. Biodesulfurization is rising as one of the candidates. Several microorganisms were found to desulfurize dibenzothiophene (DBT), a representative of the organic sulfur compounds in petroleum, forming a sulfur-free compound, 2-hydroxybiphenyl. They are promising as biocatalysts in the microbial desulfurization of petroleum because without assimilation of the carbon content, they remove only sulfur from the heterocyclic compounds which is refractory to conventional chemical desulfurization. Both enzymological and molecular genetic studies are now in progress for the purpose of obtaining improved desulfurization activity of organisms. The genes involved in the sulfur-specific DBT desulfurization were identified and the corresponding enzymes have been investigated. From the practical point of view, it has been proved that the microbial desulfurization proceeds in the presence of high concentrations of hydrocarbons, and more complicated DBT analogs are also desulfurized by the microorganisms. This review outlines the progress in the studies of the microbial desulfurization from the basic and practical point of view.

  16. Onsite treatment of volatile organic compounds in groundwater

    SciTech Connect

    Steele, J L

    1983-01-01

    Volatile organic compounds (trichloroethylene and tetrachloroethylene) were discovered in a shallow groundwater zone. A three-phase program was implemented to systematically address the problem. Principal sources and location of the contaminants were identified along with appropriate remedial action technology. A pilot air stripping column was installed to evaluate air stripping. A 50-gpm production unit is being built and will be followed by a 400-gpm production unit.

  17. Fiber optic micromirror sensor for volatile organic compounds

    SciTech Connect

    Butler, M.A.; Ricco, A.J.; Buss, R. )

    1990-04-01

    With the growing concern over environmental pollution, there is a need for sensors to locate and measure the distribution of a wide range of pollutants. In this paper the authors report a fiber optic sensor, based on a thin film micromirror, which responds to a wide range of volatile organic compounds (VOCs). This generic class of sensor will be useful for monitoring applications where the pollutant has already been identified.

  18. Sugar-Related Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, G.; Kimmich, N.; Belisle, W.; Sarinana, J.; Brabham, K.; Garrel, L.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Sugars and related polyols are critical components of all organisms and may have been necessary for the origin of life. To date, this class of organic compounds had not been definitively identified in meteorites. This study was undertaken to determine if polyols were present in the early Solar System as constituents of carbonaceous meteorites. Results of analyses of the Murchison and Murray meteorites indicate that formaldehyde and sugar chemistry may be responsible for the presence of a variety of polyols. We conclude that polyols were present on the early Earth through delivery by asteroids and possibly comets.

  19. Speciation of volatile organic compounds from poultry production

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; Li, Hong; Burns, Robert; Xin, Hongwei; Hatfield, Jerry

    2010-09-01

    Volatile organic compounds (VOCs) emitted from poultry production are leading source of air quality problems. However, little is known about the speciation and levels of VOCs from poultry production. The objective of this study was the speciation of VOCs from a poultry facility using evacuated canisters and sorbent tubes. Samples were taken during active poultry production cycle and between production cycles. Levels of VOCs were highest in areas with birds and the compounds in those areas had a higher percentage of polar compounds (89%) compared to aliphatic hydrocarbons (2.2%). In areas without birds, levels of VOCs were 1/3 those with birds present and compounds had a higher total percentage of aliphatic hydrocarbons (25%). Of the VOCs quantified in this study, no single sampling method was capable of quantifying more than 55% of compounds and in several sections of the building each sampling method quantified less than 50% of the quantifiable VOCs. Key classes of chemicals quantified using evacuated canisters included both alcohols and ketones, while sorbent tube samples included volatile fatty acids and ketones. The top five compounds made up close to 70% of VOCs and included: 1) acetic acid (830.1 μg m -3); 2) 2,3-butanedione (680.6 μg m -3); 3) methanol (195.8 μg m -3); 4) acetone (104.6 μg m -3); and 5) ethanol (101.9 μg m -3). Location variations for top five compounds averaged 49.5% in each section of the building and averaged 87% for the entire building.

  20. Volatile organic compound emissions from dry mill fuel ethanol production.

    PubMed

    Brady, Daniel; Pratt, Gregory C

    2007-09-01

    Ethanol fuel production is growing rapidly in the rural Midwest, and this growth presents potential environmental impacts. In 2002, the U.S. Environmental Protection Agency (EPA) and the Minnesota Pollution Control Agency (MPCA) entered into enforcement actions with 12 fuel ethanol plants in Minnesota. The enforcement actions uncovered underreported emissions and resulted in consent decrees that required pollution control equipment be installed. A key component of the consent decrees was a requirement to conduct emissions tests for volatile organic compounds (VOCs) with the goal of improving the characterization and control of emissions. The conventional VOC stack test method was thought to underquantify total VOC emissions from ethanol plants. A hybrid test method was also developed that involved quantification of individual VOC species. The resulting database of total and speciated VOC emissions from 10 fuel ethanol plants is relatively small, but it is the most extensive to date and has been used to develop and gauge compliance with permit limits and to estimate health risks in Minnesota. Emissions were highly variable among facilities and emissions units. In addition to the variability, the small number of samples and the presence of many values below detection limits complicate the analysis of the data. To account for these issues, a nested bootstrap procedure on the Kaplan-Meier method was used to calculate means and upper confidence limits. In general, the fermentation scrubbers and fluid bed coolers emitted the largest mass of VOC emissions. Across most facilities and emissions units ethanol was the pollutant emitted at the highest rate. Acetaldehyde, acetic acid, and ethyl acetate were also important emissions from some units. Emissions of total VOCs, ethanol, and some other species appeared to be a function of the beer feed rate, although the relationship was not reliable enough to develop a production rate-based emissions factor.

  1. Emerging role of phenolic compounds as natural food additives in fish and fish products.

    PubMed

    Maqsood, Sajid; Benjakul, Soottawat; Shahidi, Fereidoon

    2013-01-01

    Chemical and microbiological deteriorations are principal causes of quality loss of fish and fish products during handling, processing, and storage. Development of rancid odor and unpleasant flavor, changes of color and texture as well as lowering nutritional value in fish can be prevented by appropriate use of additives. Due to the potential health hazards of synthetic additives, natural products, especially antioxidants and antimicrobial agents, have been intensively examined as safe alternatives to synthetic compounds. Polyphenols (PP) are the natural antioxidants prevalent in fruits, vegetables, beverages (tea, wine, juices), plants, seaweeds, and some herbs and show antioxidative and antimicrobial activities in different fish and fish products. The use of phenolic compounds also appears to be a good alternative for sulphiting agent for retarding melanosis in crustaceans. Phenolic compounds have also been successfully employed as the processing aid for texture modification of fish mince and surimi. Thus, plant polyphenolic compounds can serve as potential additives for preventing quality deterioration or to retain the quality of fish and fish products.

  2. Methods for the determination of organic compounds in drinking water

    SciTech Connect

    Not Available

    1988-12-01

    Thirteen analytical methods for the identification and measurement of organic compounds in drinking water are described in detail. Six of the methods are for volatile organic compounds (VOCs) and certain disinfection by-products. These methods were cited in the Federal Register of July 8, 1987, under the National Primary Drinking Water Regulations. The other seven methods are designed for the determination of a variety of synthetic organic compounds and pesticides, and these methods were cited in proposed drinking-water regulations in the Federal Register of May 22, 1989. Five of the methods utilize the inert gas purge-and-trap extraction procedure for VOCs, six methods employ a classical liquid-liquid extraction, one method uses a new liquid-solid extraction technique, and one method is for direct aqueous analysis. Of the 13 methods, 12 use either packed or capillary gas-chromatography column separations followed by detection with mass spectrometry or a selective gas-chromatography detector. One method is based on a high-performance liquid-chromatography separation.

  3. Refractory Organic Compounds in Enceladus' Ice Grains and Hydrothermal Activity

    NASA Astrophysics Data System (ADS)

    Postberg, F.; Khawaja, N.; Hsu, H. W.; Sekine, Y.; Shibuya, T.

    2015-12-01

    Cassini's Cosmic Dust Analyzer (CDA) generates time-of-flight mass spectra of individual grains impinging on the instruments target-plate. Following the analysis of salt rich ice grains emitted by Enceladus that indicated a salt-water ocean in contact with the moon's rocky core [1,2] a recent CDA analysis of nano-phase silica particles pointed at hydrothermal activity at the moon's rock/water interface [3]. The results imply temperatures above 80 - 90°C and alkaline pH values around 10 reminiscent of alkaline hydrothermal vents on Earth like the Lost City Hydrothermal Field. In this context the compositional analysis of organic components in CDA mass spectra of the ejected ice grains is of particular relevance. A multitude of volatile organic species has already been identified in the gas component of the plume [4]. As expected, we find more complex organic molecules in ice grains than in the gas indicating aromatic species, amines, and carbonyl group species. The composition of organic-bearing ice grains displays a great diversity indicating a variety of different organic species in varying concentrations. Recent spatially resolved CDA in situ measurements inside Enceladus' plume indicate that these organic compounds are especially frequent in 'young' ice grains that have just been ejected by high velocity jets. We investigate the implications of our findings with respect to ice grain formation at the water surface and inside the icy vents. We constrain the generation of organic compounds at the rock/water interface in the light of hydrothermal activity and the potential for the formation of life precursor molecules in Enceladus' ocean. Ref:[1] Postberg et al., Nature 459, 1098-1101 (2009). [2] Postberg et al., Nature 474, 620-622 (2011). [3]. Hsu, Postberg, Sekine et al., Nature, 519, 207-210 (2015). [4] Waite et al., Nature 460, 487-490 (2009).

  4. A survey of household products for volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Sack, Thomas M.; Steele, David H.; Hammerstrom, Karen; Remmers, Janet

    A total of 1159 common household products were analysed for 31 volatile organic compounds as potential sources of indoor air pollution. The products were distributed among 65 product categories within 8 category classes: automotive products (14.4% of the products); household cleaners/polishes (9.6%); paint-related products (39.9%); fabric and leather treatments (7.9%); cleaners for electronic equipment (6.0%); oils, greases and lubricants (9.6%); adhesive-related products (6.6%); and miscellaneous products (6.1%). The study was conducted in two parts. In the first part, or the original study, the products were reanalysed for methylene chloride and five other chlorocarbons using purge-and-trap gas chromatography/mass spectrometry (GC/MS), and a data base containing the analytical results was developed. Because full mass spectra were taken, the original set of GC/MS data also contained information regarding other volatile chemicals in the products. However, this additional data was not reported at that time. In the second part of the study, the GC/MS data were reanalysed to determine the presence and concentrations of an additional 25 volatile chemicals. The 31 chemicals included in both parts of this study were: carbon tetrachloride; methylene chloride; tetrachloroethylene; 1,1,1-trichloroethane; trichlorethylene; 1,1,2-tricholorotrifluoroethane; acetone; benzene; 2-butanone; chlorobenzene; chloroform; cyclohexane; 1,2-dichloroethane; 1,4-dioxane; ethylbenzene; n-hexane; d-limonene; methylcyclohexane; methylcyclopentane; methyl isobutyl ketone; n-nonane; n-octane; α-pinene; propylene oxide; styrene; 1,1,2,2-tetrachloroethane; tetrahydrofuran; toluene; m-mxylene; o-xylene; and p-xylene. Of the 31 chemicals, toluene, the xylenes and methylene chloride were found to occur most frequently—in over 40% of the products tested. Chemicals that were typically found in relatively high concentrations in the samples (i.e. greater than 20% w/w) included acetone, 2-butanone

  5. Determination of organic nitro compounds using HPLC-UV-PAED

    NASA Astrophysics Data System (ADS)

    Marple, Ronita L.; LaCourse, William R.

    2004-12-01

    High-performance liquid chromatography with ultra violet and photo-assisted electrochemical detection (HPLC-UV-PAED) has been applied to the sensitive and selective determination of organic nitro compounds. The system was first developed for the determination of nitro explosives, and PAED has shown superior sensitivity over UV detection for these compounds (i.e., <1 part-per-trillion for HMX). The system also shows enhanced selectivity over the traditional UV method in that two detectors can be used for improved analyte identification. Also, having two detectors permits chemometric resolution of overlapping peaks, and this is not addressed in the UV method. Because this method is applicable to a wide range of nitro explosives, it was predicted that PAED would show the same sensitivity and selectivity toward other types of nitro compounds. Since its development, the system's use has been expanded to include the determination of nitro-containing pharmaceuticals and glycosylated nitro compounds in biological matrices. Model compounds were chosen, specifically nitroglycerin and related compounds and nitrophenyl-glucoside, to represent these classes. PAED showed superior detection limits over low wavelength UV detection for nitroglycerin (PAED = 0.3ppb, UV at 220nm = 48ppb), demonstrating PAED"s applicability to determining nitro-pharmaceuticals. Conversely, UV detection at 220nm proved to be more sensitive than PAED for nitrophenyl-glucoside (UV at 220 = 0.6ppb, PAED = 3.6ppb). However, when nitrophenyl-glucoside was spiked into urine, PAED determination resulted in 99+0.3% recovery, while UV at 220nm resulted in 116+0.2% recovery, suggesting that UV determination may suffer from matrix interference.

  6. Microbial cycling of volatile organic sulfur compounds in anoxic environments.

    PubMed

    Lomans, B P; Pol, A; Op den Camp, H J M

    2002-01-01

    Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.

  7. Organic Compounds in Clackamas River Water Used for Public Supply near Portland, Oregon, 2003-05

    USGS Publications Warehouse

    Carpenter, Kurt D.; McGhee, Gordon

    2009-01-01

    Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, gasoline hydrocarbons, solvents, personal care and domestic-use products, disinfection by-products, and manufacturing additives. In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the intake for the Clackamas River Water plant, one of four community water systems on the lower Clackamas River. The diversity of compounds detected suggests a variety of different sources and uses (including wastewater discharges, industrial, agricultural, domestic, and others) and different pathways to drinking-water supplies (point sources, precipitation, overland runoff, ground-water discharge, and formation during water treatment). A total of 20 organic compounds were commonly detected (in at least 20 percent of the samples) in source water and (or) finished water. Fifteen compounds were commonly detected in source water, and five of these compounds (benzene, m- and p-xylene, diuron, simazine, and chloroform) also were commonly detected in finished water. With the exception of gasoline hydrocarbons, disinfection by-products, chloromethane, and the herbicide diuron, concentrations in source and finished water were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about 60 percent of the compounds detected. On the basis of this screening-level assessment, adverse effects to human health are assumed to be negligible (subject to limitations of available human-health benchmarks).

  8. Incremental Reactivity Effects of Anthropogenic and Biogenic Volatile Organic Compounds on Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Kacarab, M.; Li, L.; Carter, W. P. L.; Cocker, D. R., III

    2015-12-01

    Two surrogate reactive organic gas (ROG) mixtures were developed to create a controlled reactivity environment simulating different urban atmospheres with varying levels of anthropogenic (e.g. Los Angeles reactivity) and biogenic (e.g. Atlanta reactivity) influences. Traditional chamber experiments focus on the oxidation of one or two volatile organic compound (VOC) precursors, allowing the reactivity of the system to be dictated by those compounds. Surrogate ROG mixtures control the overall reactivity of the system, allowing for the incremental aerosol formation from an added VOC to be observed. The surrogate ROG mixtures were developed based on that used to determine maximum incremental reactivity (MIR) scales for O3 formation from VOC precursors in a Los Angeles smog environment. Environmental chamber experiments were designed to highlight the incremental aerosol formation in the simulated environment due to the addition of an added anthropogenic (aromatic) or biogenic (terpene) VOC. All experiments were conducted in the UC Riverside/CE-CERT dual 90m3 environmental chambers. It was found that the aerosol precursors behaved differently under the two altered reactivity conditions, with more incremental aerosol being formed in the anthropogenic ROG system than in the biogenic ROG system. Further, the biogenic reactivity condition inhibited the oxidation of added anthropogenic aerosol precursors, such as m-xylene. Data will be presented on aerosol properties (density, volatility, hygroscopicity) and bulk chemical composition in the gas and particle phases (from a SYFT Technologies selected ion flow tube mass spectrometer, SIFT-MS, and Aerodyne high resolution time of flight aerosol mass spectrometer, HR-ToF-AMS, respectively) comparing the two controlled reactivity systems and single precursor VOC/NOx studies. Incremental aerosol yield data at different controlled reactivities provide a novel and valuable insight in the attempt to extrapolate environmental chamber

  9. Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils

    SciTech Connect

    Jagadamma, Sindhu; Mayes, Melanie; Phillips, Jana Randolph

    2012-01-01

    Physico-chemical sorption of dissolved organic carbon (DOC) on soil minerals is one of the major processes of organic carbon (OC) stabilization in soils, especially in deeper layers. The attachment of C on soil solids is related to the reactivity of the soil minerals and the chemistry of the sorbate functional groups, but the sorption studies conducted without controlling microbial activity may overestimate the sorption potential of soil. This study was conducted to examine the sorptive characteristics of a diverse functional groups of simple OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols) with and without biological degradative processes. Equilibrium batch experiments were conducted using 0-100 mg C L-1 at a solid-solution ratio of 1:60 for 48 hrs and the sorption parameters were calculated by Langmuir model fitting. The amount of added compounds that remained in the solution phase was detected by high performance liquid chromatography (HPLC) and total organic C (TOC) analysis. Soil sterilization was performed by -irradiation technique and experiments were repeated to determine the contribution of microbial degradation to apparent sorption. Overall, Ultisols did not show a marked preference for apparent sorption of any of the model compounds, as indicated by a narrower range of maximum sorption capacity (Smax) of 173-527 mg kg soil-1 across compounds. Mollisols exhibited a strong preference for apparent sorption of oxalic acid (Smax of 5290 mg kg soil-1) and sinapyl alcohol (Smax of 2031 mg kg soil-1) over the other compounds. The propensity for sorption of oxalic acid is mainly attributed to the precipitation of insoluble Ca-oxalate due to the calcareous nature of most Mollisol subsoils and its preference for sinapyl alcohol could be linked to the polymerization of this lignin monomer on 2:2 mineral dominated soils. The reactivity of Alfisols to DOC was in

  10. On the site preferences of ternary additions to triple defect B2 intermetallic compounds

    SciTech Connect

    Pike, L.M.; Chen, S.L.; Chang, Y.A.

    1995-12-31

    Knowledge of the site preference of ternary solute additions is essential to developing an understanding of how these solutes affect the properties of B2 intermetallic compounds. A quasichemical model will be presented which is able to predict the site preferences of dilute solute additions to triple defect B2 compounds. The only parameters required are enthalpies of formation at the stoichiometric composition. General equations are developed which can be used to determine site occupations and defect concentrations for dilute as well as non-dilute solute additions. These equations use atom pair bond enthalpies as the parameters. It is found that the site preferences of dilute additions are not always in agreement with predictions based on the solubility lobes in ternary Gibbs isotherms, Predictions for dilute additions to NiAl and FeAl are compared to experimental results found in the literature. Satisfactory correlation is found between the model and the experimental results. In addition, the predictions from the model on vacancy concentrations in Fe doped NiAl are compared to recent experimental results by the authors.

  11. Enhanced laccase production in white-rot fungus Rigidoporus lignosus by the addition of selected phenolic and aromatic compounds.

    PubMed

    Cambria, Maria Teresa; Ragusa, Santa; Calabrese, Vittorio; Cambria, Antonio

    2011-02-01

    The white rot fungus Rigidoporus lignosus produces substantial amounts of extracellular laccase, a multicopper blue oxidase which is capable of oxidizing a wide range of organic substrates. Laccase production can be greatly enhanced in liquid cultures supplemented with various aromatic and phenolic compounds. The maximum enzyme activity was reached at the 21st or 24th day of fungal cultivation after the addition of inducers. The zymograms of extracellular fluid of culture preparation in the presence of inducers, at maximum activity day, revealed two bands with enzymatic activity, called Lac1 and Lac2, having different intensities. Lac2 band shows the higher intensity which changed with the different inducers. Laccase induction can be also obtained by adding to the culture medium olive mill wastewaters, which shows a high content of phenolic compounds.

  12. Presence and distribution of chlorinated organic compounds in streambed sediments, new jersey

    USGS Publications Warehouse

    Stackelberg, P.E.

    1997-01-01

    Concentrations of 18 hydrophobic chlorinated organic compounds in streambed sediments from 100 sites throughout New Jersey were examined to determine (1) which compounds were detected most frequently, (2) whether detection frequencies differed among selected drainage basins, and (3) whether concentrations differed significantly among selected drainage basins. Twelve drainage basins across New Jersey that contain a range of land-use patterns and population densities were selected to represent various types and degrees of development. To ensure an adequate number of samples for statistical comparison among drainage basins, the 12 selected basins were consolidated into seven drainage areas on the basis of similarities in land- use patterns and population densities. Additionally, data for three classes of chlorinated organic compounds in streambed sediments from 255 sites throughout New Jersey were examined to determine whether the presence of these compounds in streambed sediments is related to the type and degree of development within the drainage area of each sampling site. Chlorinated organic compounds detected most frequently within the seven representative drainage areas were DDT, DDE, DDD, chlordane, dieldrin, and PCBs. DDT, DDE, and DDD, which were the most widely distributed organic compounds, were detected in about 60 to 100 percent of the samples from all drainage areas hut one (where the detection rate for these compounds was about 20 to 40 percent). Chlordane and dieldrin were detected in about 80 to 100 percent of samples from highly urbanized and populated drainage areas; detection frequencies for these compounds tended to be smaller in less developed and populated areas. PCBs were detected in about 40 to 85 percent of samples from all drainage areas; detection frequencies were highest in the most heavily developed and populated areas. Analysis of variance on rank-transformed organic compound concentrations normalized to sediment organic carbon content

  13. Compound specific 13C- and 18O-isotope analysis of organic aerosols

    NASA Astrophysics Data System (ADS)

    Blees, Jan; Saurer, Matthias; Siegwolf, Rolf T. W.; Dommen, Josef; Baltensperger, Urs

    2014-05-01

    . Elements other than carbon may provide valuable additional information. Here we report on the development of methods for the analysis of stable carbon and oxygen isotope ratios of organic compounds in aerosols, through GC-combustion-irMS and GC-pyrolysis-irMS. We apply these analyses to environmental aerosol samples and samples of smog-chamber experiments, with the aim of identifying isotopic signatures of sources and pathways. We will pay special attention to derivatisation techniques - notably alternatives to the often-used trimethylsilyl derivatives in GC-pyrolysis-irMS for δ18O analysis - and to compound separation and identification. We present initial data of combined δ13C and δ18O studies on (secondary) organic aerosol samples, and their added value for source apportionment studies.

  14. Multiple microbial activities for volatile organic compounds reduction by biofiltration.

    PubMed

    Civilini, Marcello

    2006-07-01

    In the northeast of Italy, high volatile organic carbon (VOC) emissions originate from small-medium companies producing furniture. In these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. Among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple VOC degradation potentials used to oxidize these compounds to CO2. Starting from the air emissions of a typical industrial wood-painting plant, a series of experiments studied in vitro microbial degradation of each individual VOC. Isolated strains were then added to a laboratory-scale biofiltration apparatus filled with an organic matrix, and the different VOC behavior demonstrated the potential of single and/or synergic microbial removal actions. When a single substrate was fed, the removal efficiency of a Pseudomonas aeruginosa inoculated reactor was 1.1, 1.17, and 0.33 g m(-3) hr(-1), respectively, for xylene, toluene, and ethoxy propyl acetate. A VOC mixture composed of butyl acetate, ethyl acetate, diacetin alcohol, ethoxy propanol acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene was then fed into a 2-m(3) reactor treating 100 m3 hr(-1) of contaminated air. The reactor was filled with the same mixture of organic matrix, enriched with all of the isolated strains together. During reactor study, different VOC loading rates were used, and the behavior was evaluated continuously. After a short acclimation period, the removal efficiency was > 65% at VOC load of 150-200 g m(-3) hr(-1). Quantification of removal efficiencies and VOC speciation confirmed the relationship among removal efficiencies, compound biodegradability, and the dynamic transport of each mixture component within the organic matrix. Samples of the fixed bed were withdrawn at different intervals and the heterogeneous microbial community evaluated for both total and differential compound counts. PMID:16878585

  15. Organic compounds in hot-water-soluble fractions from water repellent soils

    NASA Astrophysics Data System (ADS)

    Atanassova, Irena; Doerr, Stefan

    2014-05-01

    Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes < C20) were extracted through desorption of complex colloids stabilized as micelles in dissolved organic carbon (DOC). Water repellency was completely eliminated by hot water under high pressure. The molecular composition of HWSC can play a critical role in stabilization and destabilization of soil organic matter (SOM), particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds

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

    USGS Publications Warehouse

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Effect of volatile organic compounds from bacteria on nematodes.

    PubMed

    Xu, You-Yao; Lu, Hao; Wang, Xin; Zhang, Ke-Qin; Li, Guo-Hong

    2015-09-01

    The five studied bacterial strains could produce volatile organic compounds (VOCs) that kill nematodes. Based on their 16S rRNA sequences, these strains were identified as Pseudochrobactrum saccharolyticum, Wautersiella falsenii, Proteus hauseri, Arthrobacter nicotianae, and Achromobacter xylosoxidans. The bacterial VOCs were extracted using solid-phase micro-extraction (SPME) and subsequently identified by GC/MS analysis. The VOCs covered a wide range of aldehydes, ketones, alkyls, alcohols, alkenes, esters, alkynes, acids, ethers, as well as heterocyclic and phenolic compounds. Among the 53 VOCs identified, 19 candidates, produced by different bacteria, were selected to test their nematicidal activity (NA) against Caenorhabditis elegans and Meloidogyne incognita. The seven compounds with the highest NAs were acetophenone, S-methyl thiobutyrate, dimethyl disulfide, ethyl 3,3-dimethylacrylate, nonan-2-one, 1-methoxy-4-methylbenzene, and butyl isovalerate. Among them, S-methyl thiobutyrate showed a stronger NA than the commercial insecticide dimethyl disulfide. It was reported for the first time here that the five bacterial strains as well as S-methyl thiobutyrate, ethyl 3,3-dimethylacrylate, 1-methoxy-4-methylbenzene, and butyl isovalerate possess NA. These strains and compounds might provide new insights in the search for novel nematicides.

  19. Prediction of solvation enthalpy of gaseous organic compounds in propanol

    NASA Astrophysics Data System (ADS)

    Golmohammadi, Hassan; Dashtbozorgi, Zahra

    2016-09-01

    The purpose of this paper is to present a novel way for developing quantitative structure-property relationship (QSPR) models to predict the gas-to-propanol solvation enthalpy (Δ H solv) of 95 organic compounds. Different kinds of descriptors were calculated for each compound using the Dragon software package. The variable selection technique of replacement method (RM) was employed to select the optimal subset of solute descriptors. Our investigation reveals that the dependence of physical chemistry properties of solution on solvation enthalpy is nonlinear and that the RM method is unable to model the solvation enthalpy accurately. The results established that the calculated Δ H solv values by SVM were in good agreement with the experimental ones, and the performances of the SVM models were superior to those obtained by RM model.

  20. Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

    PubMed

    Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

    2007-01-01

    The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

  1. Native Fluorescence Detection Methods, Devices, and Systems for Organic Compounds

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Bhartia, Rohit (Inventor); Reid, Ray D. (Inventor); Lane, Arthur L. (Inventor)

    2016-01-01

    Naphthalene, benzene, toluene, xylene, and other volatile organic compounds VOCs have been identified as serious health hazards. 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 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.

  2. Influence of Concentration and Salinity on the Biodegradability of Organic Additives in Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Mouser, P. J.; Kekacs, D.

    2014-12-01

    One of the risks associated with the use of hydraulic fracturing technologies for energy development is the potential release of hydraulic fracturing-related fluids into surface waters or shallow aquifers. Many of the organic additives used in hydraulic fracturing fluids are individually biodegradable, but little is know on how they will attenuate within a complex organic fluid in the natural environment. We developed a synthetic hydraulic fracturing fluid based on disclosed recipes used by Marcellus shale operators to evaluate the biodegradation potential of organic additives across a concentration (25 to 200 mg/L DOC) and salinity gradient (0 to 60 g/L) similar to Marcellus shale injected fluids. In aerobic aqueous solutions, microorganisms removed 91% of bulk DOC from low SFF solutions and 57% DOC in solutions having field-used SFF concentrations within 7 days. Under high SFF concentrations, salinity in excess of 20 g/L inhibited organic compound biodegradation for several weeks, after which time the majority (57% to 75%) of DOC remained in solution. After SFF amendment, the initially biodiverse lake or sludge microbial communities were quickly dominated (>79%) by Pseudomonas spp. Approximately 20% of added carbon was converted to biomass while the remainder was respired to CO2 or other metabolites. Two alcohols, isopropanol and octanol, together accounted for 2-4% of the initial DOC, with both compounds decreasing to below detection limits within 7 days. Alcohol degradation was associated with an increase in acetone at mg/L concentrations. These data help to constrain the biodegradation potential of organic additives in hydraulic fracturing fluids and guide our understanding of the microbial communities that may contribute to attenuation in surface waters.

  3. QSPR Modeling of Bioconcentration Factors of Nonionic Organic Compounds

    PubMed Central

    Deeb, Omar; Khadikar, Padmakar V.; Goodarzi, Mohammad

    2010-01-01

    The terms bioaccumulation and bioconcentration refer to the uptake and build-up of chemicals that can occur in living organisms. Experimental measurement of bioconcentration is time-consuming and expensive, and is not feasible for a large number of chemicals of potential regulatory concern. A highly effective tool depending on a quantitative structure-property relationship (QSPR) can be utilized to describe the tendency of chemical concentration organisms represented by, the important ecotoxicological parameter, the logarithm of Bio Concentration Factor (log BCF) with molecular descriptors for a large set of non-ionic organic compounds. QSPR models were developed using multiple linear regression, partial least squares and neural networks analyses. Linear and non-linear QSPR models to predict log BCF of the compounds developed for the relevant descriptors. The results obtained offer good regression models having good prediction ability. The descriptors used in these models depend on the volume, connectivity, molar refractivity, surface tension and the presence of atoms accepting H-bonds. PMID:20706622

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

    PubMed

    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.

  5. Seeking organic compounds on Mars : in situ analysis of organic compounds by Gas Chromatography-Mass Spectrometry on MOMA experiment

    NASA Astrophysics Data System (ADS)

    Buch, A.; Freissinet, C.; Sternberg, R.; Pinnick, V.; Szopa, C.; Coll, P. J.; Rodier, C.; Garnier, C.; Steininger, H.; Moma Team

    2010-12-01

    The search for signs of past or present life is one of the primary goals of future Mars exploratory missions. The Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars mission (set to launch 2016-2018) is a joint venture by the European Space Agency and NASA to develop a sensitive detector for organics on Mars. MOMA will be one of the main analytical instruments aboard the ExoMars Rover aimed at characterizing possible “signs-of-life molecules” in the Martian environment such as amino acids, carboxylic acids, nucleobases or polycyclic aromatic hydrocarbons (PAHs). With the aim to separate and detect organic compounds from Martian soil, the French MOMA team has built a gas chromatograph able to work in standalone mode by using a TCD detector. The gas chromatograph can also be coupled with an ion trap mass spectrometer developed by the US MOMA team. Moreover, a GC-MS compatible sample processing system (SPS) allowing the extraction and the chemical transformation of the organic compounds from the soil, that fits within space flight conditions, has also been developed. The sample processing is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of oven can be ranged from 20 to 1000 °C which allows for pyrolysis, thermochemolysis or derivatization. The organic extraction step is achieved by using thermodesorption in the range of 100 to 300°C for 0.5 to 5 min. Then, the chemical derivatization and/or thermochemolysis of the extracted compounds is performed directly on the soil with a mixture of MTBSTFA-DMF, TMAH or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the target molecules, this step allows for their volatilization at a temperature below 250°C without any chemical degradation. Once derivatized, the volatile target molecules are trapped in a cold chemical trap and promptly desorbed into the gas chromatograph coupled to the mass

  6. Identification and quantification of volatile organic compounds from a dairy

    NASA Astrophysics Data System (ADS)

    Filipy, Jenny; Rumburg, Brian; Mount, George; Westberg, Hal; Lamb, Brian

    Volatile organic compounds (VOCs) that contribute to odor and air quality problems have been identified from the Washington State University Knott Dairy Farm using gas chromatography-mass spectroscopy (GC-MS). Eighty-two VOCs were identified at a lactating cow open stall and 73 were detected from a slurry wastewater lagoon. These compounds included alcohols, aldehydes, ketones, esters, ethers, aromatic hydrocarbons, halogenated hydrocarbons, terpenes, other hydrocarbons, amines, other nitrogen containing compounds, and sulfur-containing compounds. The concentration of VOCs directly associated with cattle waste increased with ambient air temperature, with the highest concentrations present during the summer months. Concentrations of most detected compounds were below published odor detection thresholds. Emission rates of ethanol (1026±513 μg cow -1 s -1) and dimethyl sulfide (DMS) (13.8±10.3 μg cow -1 s -1) were measured from the lactating stall area using an atmospheric tracer method and concentrations were plotted using data over a 2-year period. Emission rates of acetone (3.03±0.85 ng cow -1 s -1), 2-butanone (145±35 ng cow -1 s -1), methyl isobutyl ketone (3.46±1.11 ng cow -1 s -1), 2-methyl-3-pentanone (25.1±8.0 ng cow -1 s -1), DMS (2.19±0.92 ng cow -1 s -1), and dimethyl disulfide (DMDS) (16.1±3.9 ng cow -1 s -1) were measured from the slurry waste lagoon using a laboratory emission chamber.

  7. Allochthonous Addition of Meteoritic Organics to the Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; Clemett, S.; Ross, D. K.; Le, L.; Rahman, Z.; McKay, D. S.; Gibson, E. K.; Gonzalez, C.

    2013-01-01

    Preparation of lunar samples 74220,861 was discussed in detail in [3, 4]. Our analysis sequence was as follows: optical microscopy, UV fluorescence imaging, -Raman, FESEM-EDX imaging and mapping, FETEMEDX imaging and mapping of a Focused Ion Beam (FIB) extracted section, and NanoSIMs analysis. We observed fluffytextured C-rich regions of interest (ROI) on three different volcanic glass beads. Each ROI was several m2 in size and fluoresced when exposed to UV. Using FESEM/EDX, the largest ROI measured 36 m and was located on an edge of a plateau located on the uppermost surface of the bead. The ROI was covered on one edge by a siliceous filament emanating from the plateau surface indicating it was attached to the bead while on the Moon. EDX mapping of the ROI shows it is composed primarily of heterogeneously distributed C. Embedded with the carbonaceous phase are localized concentrations of Si, Fe, Al and Ti indicating the presence of glass and/or minerals grains. -Raman showed strong D- and G-bands and their associated second order bands; intensity and location of these bands indicates the carbonaceous matter is structurally disorganized. A TEM thin section was extracted from the surface of a glass bead using FIB microscopy. High resolution TEM imaging and selected area electron diffraction demonstrate the carbonaceous layer to be amorphous; it lacked any long or short range order characteristic of micro- or nanocrystalline graphite. Additionally TEM imaging also revealed the presence of submicron mineral grains, typically < 50 nm in size, dispersed within the carbonaceous layer. NanoSIMs data will be presented and discussed at the meeting. Given the noted similarities between the carbonaceous matter present on 74220 glass beads and meteoritic kerogen, we suggest the allochthonous addition of meteoritic organics as the most probable source for the C-rich ROIs.

  8. Spatial Arrangment of Organic Compounds on a Model Mineral Surface: Implications for Soil Organic Matter Stabilization

    SciTech Connect

    Petridis, Loukas; Ambaye, Haile Arena; Jagadamma, Sindhu; Kilbey, S. Michael; Lokitz, Bradley S; Lauter, Valeria; Mayes, Melanie

    2014-01-01

    The complexity of the mineral organic carbon interface may influence the extent of stabilization of organic carbon compounds in soils, which is important for global climate futures. The nanoscale structure of a model interface was examined here by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto a soil mineral analogue (Al2O3). Neutron reflectometry, a technique which provides depth-sensitive insight into the organization of the thin films, indicates that glucose molecules reside in a layer between Al2O3 and stearic acid, a result that was verified by water contact angle measurements. Molecular dynamics simulations reveal the thermodynamic driving force behind glucose partitioning on the mineral interface: The entropic penalty of confining the less mobile glucose on the mineral surface is lower than for stearic acid. The fundamental information obtained here helps rationalize how complex arrangements of organic carbon on soil mineral surfaces may arise

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

    PubMed

    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 yr. 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.

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

    PubMed

    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 yr. 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. PMID:22751077

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

    USGS Publications Warehouse

    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.

  12. Racemization and the origin of optically active organic compounds in living organisms

    NASA Technical Reports Server (NTRS)

    Bada, J. L.; Miller, S. L.

    1987-01-01

    The organic compounds synthesized in prebiotic experiments are racemic mixtures. A number of proposals have been offered to explain how asymmetric organic compounds formed on the Earth before life arose, with the influence of chiral weak nuclear interactions being the most frequent proposal. This and other proposed asymmetric syntheses give only sight enantiomeric excess and any slight excess will be degraded by racemization. This applies particularly to amino acids where half-lives of 10(5)-10(6) years are to be expected at temperatures characteristic of the Earth's surface. Since the generation of chiral molecules could not have been a significant process under geological conditions, the origins of this asymmetry must have occurred at the time of the origin of life or shortly thereafter. It is possible that the compounds in the first living organisms were prochiral rather than chiral; this is unlikely for amino acids, but it is possible for the monomers of RNA-like molecules.

  13. Characterization of polar organic compounds in the organic film on indoor and outdoor glass windows.

    PubMed

    Liu, Qin-Tao; Chen, Rachel; McCarry, Brian E; Diamond, Miriam L; Bahavar, Bagher

    2003-06-01

    Organic films on an impervious surface (window glass) were sampled at paired indoor-outdoor sites in July 2000 and characterized for their paraffinic and polar organic compositions along an urban-rural transect. Four classes of polar compounds (C11-C31 aliphatic monocarboxylic, C6-C14 dicarboxylic, nine aromatic polycarboxylic, and five terpenoid acids) constituted between 81 and 95% (w/w) of the total organic fraction analyzed comprising n-alkanes (C10-C36), 46 PAH, 97 PCBs, and 18 OC pesticides. Concentrations of the polar compounds plus their precursors, n-alkanes, ranged from 8 to 124 microg m(-20 and were dominated by monocarboxylic acids (67-89%, w/w). On outdoor windows, n-alkanes, aromatic acids, and terpenoid acids decreased in concentration along the urban-rural transect. The carbon preference index values and the interpretations of individual compounds indicate that the main sources of n-alkanes were plant waxes followed by petrogenic sources; monocarboxylic and dicarboxylic acids were from plant waxes and animal fats. Results of principal component analysis showed closer correspondence between outdoor and indoor signatures than among locations. In outdoor films, these compounds are suggested to play an important role in mediating chemical fate in urban areas by air-film exchange and facilitating "wash-off" due to their surfactant-like properties. In indoor films, these compounds provide a medium for the accumulation of more toxic compounds.

  14. The synthesis of organic and inorganic compounds in evolved stars.

    PubMed

    Kwok, Sun

    2004-08-26

    Recent isotopic analysis of meteorites and interplanetary dust has identified solid-state materials of pre-solar origin. We can now trace the origin of these inorganic grains to the circumstellar envelopes of evolved stars. Moreover, organic (aromatic and aliphatic) compounds have been detected in proto-planetary nebulae and planetary nebulae, which are the descendants of carbon stars. This implies that molecular synthesis is actively happening in the circumstellar environment on timescales as short as several hundred years. The detection of stellar grains in the Solar System suggests that they can survive their journey through the interstellar medium and that they are a major contributor of interstellar grains. PMID:15329712

  15. Hazardous organic compounds in groundwater near Tehran automobile industry.

    PubMed

    Dobaradaran, Sina; Mahvi, Amir Hossein; Nabizadeh, Ramin; Mesdaghinia, Alireza; Naddafi, Kazem; Yunesian, Masoud; Rastkari, Noushin; Nazmara, Shahrokh

    2010-11-01

    Potential of groundwater contamination by trichloroethylene (TCE) and other volatile organic compounds VOCs near car industry was conducted in this study. TCE, PCE, toluene, xylene, dichloromethane, cyclohexane, n-hexane and n-pentane were detected in all groundwaters. Mean TCE levels in groundwater ranged from 124.37 to 1,035.9 μg L⁻¹ with maximum level of 1,345.7 μg L⁻¹. Due to the data obtained from conventional wastewater treatment in car factory the TCE removal efficiency was only 24 percent which necessitates the TCE removal by advanced treatment processes before the use of well water.

  16. Process for removing an organic compound from water

    DOEpatents

    Baker, Richard W.; Kaschemekat, Jurgen; Wijmans, Johannes G.; Kamaruddin, Henky D.

    1993-12-28

    A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

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

    SciTech Connect

    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

  18. Quantitative extraction of organic tracer compounds from ambient particulate matter collected on polymer substrates.

    PubMed

    Sun, Qinyue; Alexandrova, Olga A; Herckes, Pierre; Allen, Jonathan O

    2009-05-15

    Organic compounds in ambient particulate matter (PM) samples are used as tracers for PM source apportionment. These PM samples are collected using high volume samplers; one such sampler is an impactor in which polyurethane foam (PUF) and polypropylene foam (PPF) are used as the substrates. The polymer substrates have the advantage of limiting particle bounce artifacts during sampling; however these substrates may contain background organic additives. A protocol of two extractions with isopropanol followed by three extractions with dichloromethane (DCM) was developed for both substrate precleaning and analyte extraction. Some residual organic contaminants were present after precleaning; expressed as concentrations in a 24-h ambient PM sample, the residual amounts were 1 microg m(-3) for plasticizers and antioxidants, and 10 ng m(-3) for n-alkanes with carbon number lower than 26. The quantification limit for all other organic tracer compounds was approximately 0.1 ng m(-3) in a 24-h ambient PM sample. Recovery experiments were done using NIST Standard Reference Material (SRM) Urban Dust (1649a); the average recoveries for polycyclic aromatic hydrocarbons (PAHs) from PPF and PUF substrates were 117+/-8% and 107+/-11%, respectively. Replicate extractions were also done using the ambient samples collected in Nogales, Arizona. The relative differences between repeat analyses were less than 10% for 47 organic tracer compounds quantified. After the first extraction of ambient samples, less than 7% of organic tracer compounds remained in the extracted substrates. This method can be used to quantify a suite of semi- and non-polar organic tracer compounds suitable for source apportionment studies in 24-h ambient PM samples.

  19. 76 FR 4835 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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... plastic composites production operations. This rule is approvable because it satisfies the...

  20. Potential for Finding Evidence of Bio/Organic Compounds in Extraterrestrial Materials

    NASA Astrophysics Data System (ADS)

    Hinman, N. W.; Richardson, C. D.; Aspden, D.; Kouri, K.; Kotler, J. M.; McHenry, L. J.; Scott, J. R.

    2010-04-01

    Results contribute to improved ability to detect bio/organic compounds and determine their biogenicity, predict which landing sites are most likely to provide evidence for life, and detect bio/organic compounds for decontamination procedures for planetary protection.

  1. 75 FR 2090 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

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

    PubMed Central

    Bennett, Joan W.; Inamdar, Arati A.

    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, 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. PMID:26402705

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

    PubMed

    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.

  4. Methods in plant foliar volatile organic compounds research1

    PubMed Central

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; 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 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. PMID:26697273

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

    PubMed

    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 < acetones < aromas, linears < branches < cycles, and para- < meta- < ortho-. The deviating 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).

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

    PubMed

    Bennett, Joan W; Inamdar, Arati A

    2015-09-01

    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, 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. PMID:26402705

  7. Acidic organic compounds in beverage, food, and feed production.

    PubMed

    Quitmann, Hendrich; Fan, Rong; Czermak, Peter

    2014-01-01

    Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications.

  8. Organic compounds in indoor air—their relevance for perceived indoor air quality?

    NASA Astrophysics Data System (ADS)

    Wolkoff, Peder; Nielsen, Gunnar D.

    It is generally believed that indoor air pollution, one way or another may cause indoor air complaints. However, any association between volatile organic compounds (VOCs) concentrations and increase of indoor climate complaints, like the sick-building syndrome symptoms, is not straightforward. The reported symptom rates of, in particular, eye and upper airway irritation cannot generally be explained by our present knowledge of common chemically non-reactive VOCs measured indoors. Recently, experimental evidence has shown those chemical reactions between ozone (either with or without nitrogen dioxide) and unsaturated organic compounds (e.g. from citrus and pine oils) produce strong eye and airway irritating species. These have not yet been well characterised by conventional sampling and analytical techniques. The chemical reactions can occur indoors, and there is indirect evidence that they are associated with eye and airway irritation. However, many other volatile and non-volatile organic compounds have not generally been measured which could equally well have potent biological effects and cause an increase of complaint rates, and posses a health/comfort risk. As a consequence, it is recommended to use a broader analytical window of organic compounds than the classic VOC window as defined by the World Health Organisation. It may include hitherto not yet sampled or identified intermediary species (e.g., radicals, hydroperoxides and ionic compounds like detergents) as well as species deposited onto particles. Additionally, sampling strategies including emission testing of building products should carefully be linked to the measurement of organic compounds that are expected, based on the best available toxicological knowledge, to have biological effects at indoor concentrations.

  9. Biogenic volatile organic compound emissions from vegetation fires.

    PubMed

    Ciccioli, Paolo; Centritto, Mauro; Loreto, Francesco

    2014-08-01

    The aim of this paper was to provide an overview of the current state of the art on research into the emission of biogenic volatile organic compounds (BVOCs) from vegetation fires. Significant amounts of VOCs are emitted from vegetation fires, including several reactive compounds, the majority belonging to the isoprenoid family, which rapidly disappear in the plume to yield pollutants such as secondary organic aerosol and ozone. This makes determination of fire-induced BVOC emission difficult, particularly in areas where the ratio between VOCs and anthropogenic NOx is favourable to the production of ozone, such as Mediterranean areas and highly anthropic temperate (and fire-prone) regions of the Earth. Fire emissions affecting relatively pristine areas, such as the Amazon and the African savannah, are representative of emissions of undisturbed plant communities. We also examined expected BVOC emissions at different stages of fire development and combustion, from drying to flaming, and from heatwaves coming into contact with unburned vegetation at the edge of fires. We conclude that forest fires may dramatically change emission factors and the profile of emitted BVOCs, thereby influencing the chemistry and physics of the atmosphere, the physiology of plants and the evolution of plant communities within the ecosystem.

  10. Biogenic volatile organic compound emissions from vegetation fires

    PubMed Central

    CICCIOLI, PAOLO; CENTRITTO, MAURO; LORETO, FRANCESCO

    2014-01-01

    The aim of this paper was to provide an overview of the current state of the art on research into the emission of biogenic volatile organic compounds (BVOCs) from vegetation fires. Significant amounts of VOCs are emitted from vegetation fires, including several reactive compounds, the majority belonging to the isoprenoid family, which rapidly disappear in the plume to yield pollutants such as secondary organic aerosol and ozone. This makes determination of fire-induced BVOC emission difficult, particularly in areas where the ratio between VOCs and anthropogenic NOx is favourable to the production of ozone, such as Mediterranean areas and highly anthropic temperate (and fire-prone) regions of the Earth. Fire emissions affecting relatively pristine areas, such as the Amazon and the African savannah, are representative of emissions of undisturbed plant communities. We also examined expected BVOC emissions at different stages of fire development and combustion, from drying to flaming, and from heatwaves coming into contact with unburned vegetation at the edge of fires. We conclude that forest fires may dramatically change emission factors and the profile of emitted BVOCs, thereby influencing the chemistry and physics of the atmosphere, the physiology of plants and the evolution of plant communities within the ecosystem. PMID:24689733

  11. Diagnosing gastrointestinal illnesses using fecal headspace volatile organic compounds

    PubMed Central

    Chan, Daniel K; Leggett, Cadman L; Wang, Kenneth K

    2016-01-01

    Volatile organic compounds (VOCs) emitted from stool are the components of the smell of stool representing the end products of microbial activity and metabolism that can be used to diagnose disease. Despite the abundance of hydrogen, carbon dioxide, and methane that have already been identified in human flatus, the small portion of trace gases making up the VOCs emitted from stool include organic acids, alcohols, esters, heterocyclic compounds, aldehydes, ketones, and alkanes, among others. These are the gases that vary among individuals in sickness and in health, in dietary changes, and in gut microbial activity. Electronic nose devices are analytical and pattern recognition platforms that can utilize mass spectrometry or electrochemical sensors to detect these VOCs in gas samples. When paired with machine-learning and pattern recognition algorithms, this can identify patterns of VOCs, and thus patterns of smell, that can be used to identify disease states. In this review, we provide a clinical background of VOC identification, electronic nose development, and review gastroenterology applications toward diagnosing disease by the volatile headspace analysis of stool. PMID:26819529

  12. Volatile organic compounds in storm water from a parking lot

    USGS Publications Warehouse

    Lopes, T.J.; Fallon, J.D.; Rutherford, D.W.; Hiatt, M.H.

    2000-01-01

    A mass balance approach was used to determine the most important nonpoint source of volatile organic compounds (VOCs) in storm water from an asphalt parking lot without obvious point sources (e.g., gasoline stations). The parking lot surface and atmosphere are important nonpoint sources of VOCs, with each being important for different VOCs. The atmosphere is an important source of soluble, oxygenated VOCs (e.g., acetone), and the parking lot surface is an important source for the more hydrophobic VOCs (e.g., benzene). VOCs on the parking lot surface appear to be concentrated in oil and grease and organic material in urban particles (e.g., vehicle soot). Except in the case of spills, asphalt does not appear to be an important source of VOCs. The uptake isotherm of gaseous methyl tert-butyl ether on urban particles indicates a mechanism for dry deposition of VOCs from the atmosphere. This study demonstrated that a mass balance approach is a useful means of understanding non-point-source pollution, even for compounds such as VOCs, which are difficult to sample.

  13. Partitioning of Organic Compounds into Supercritical CO2 in Depleted Oil Reservoirs - A Review

    NASA Astrophysics Data System (ADS)

    Burant, A.; Lowry, G. V.; Karamalidis, A.

    2012-12-01

    Depleted oil reservoirs, with enhanced oil recovery, will be one of the first adopters of carbon capture and storage (CCS), which is a promising mitigation strategy for global climate change. The large scale implementation of CCS mandates better understanding of the risks associated with CO2 injection, especially in regards to potential leakage of the stored CO2. Organics, in the residual oil and dissolved in the brine, can partition into supercritical CO2 (sc-CO2) and move with that phase if it leaks. This review presents an overview of the thermodynamic models and trends in experimental partitioning data needed to understand what compounds may be expected to move with the sc-CO2. There are two main types of thermodynamic models used for predicting the solubility of organic compounds in sc-CO2, equations of state and quantitative structure activity relationships. Both can predict the partitioning behavior of one compound in sc-CO2, however only equations of state can predict solubility in multicomponent systems. In addition, equations of state have been developed to determine the effect of electrolytes on the partitioning behavior of organics dissolved in brines. There are three main trends in the partitioning behavior of organics in sc-CO2: Pure phase solubility follows trends in vapor pressure; compounds with higher volatility have higher solubility in sc-CO2. Second, the partitioning from water to sc-CO2 follows trends in Henry's constants, which follow the relative solubility of a compound in both the sc-CO2 and aqueous phases. Thirdly, the solubility of a compound can be enhanced by the presence of another; highly volatile compounds enhance the solubility of compounds with lower volatility. Finally, the review presents the gaps in experimental research that can be used to improve the modeling of the partitioning behavior of organics in sc-CO2, specifically in regards to co-solvency effects and the effects of electrolytes on the partitioning of dissolved

  14. Chiral Analyses of Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Pizzarello, Sandra

    2004-01-01

    Contents include the following: 1. Characterization of Tagish Lake organic content. The first two grant years were largely devoted to the molecular and isotopic analyses of Tagish Lake organic composition. This carbonaceous meteorite fell in Canada in the winter of the year 2000, and its exceptional atmospheric entry and subsequent recovery (e. g., the sample was recovered and stored by avoiding hand contact and above freezing temperatures) contributed in providing a rare and pristine extraterrestrial material. 2. Chiral analyses of Murchison and Murray soluble organics. One of the most intriguing finding in regard to soluble meteorite organics is the presence within the amino acid suite of some compounds displaying L-enantiomeric excesses. This configuration is exclusive in the amino acids of terrestrial proteins and the finding has raised speculations of a possible role of amino acids from meteorites in the origin of homochirality on the early Earth. The main objective for this NASA funding was the characterization of enantiomeric excesses in meteorites and we have conducted several studies toward establishing their distribution and indignity.

  15. Investigation of membrane fouling in ultrafiltration using model organic compounds.

    PubMed

    Kweon, J H; Lawler, D F

    2005-01-01

    Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface.

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

    PubMed

    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. PMID:26495281

  17. Investigation of membrane fouling in ultrafiltration using model organic compounds.

    PubMed

    Kweon, J H; Lawler, D F

    2005-01-01

    Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface. PMID:16003967

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

    PubMed

    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.

  19. Development and Mining of a Volatile Organic Compound Database

    PubMed Central

    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. PMID:26495281

  20. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for Volatile Organic Compound... with a vapor collection system designed to collect the total organic compounds vapors displaced from... total organic compounds per liter of gasoline loaded, except as noted in paragraph (c) of this...

  1. Manmade organic compounds in the surface waters of the United States

    SciTech Connect

    Smith, J.A.; Witkowski, P.J.; Fusillo, T.V.

    1988-01-01

    This report reviews the scientific literature with reference to the processes influencing the occurrence and distribution of manmade organic compounds in surface-water systems. The distribution and concentration of organic compounds in these systems are affected by sorption, bioaccumulation, photolysis, hydrolysis, biodegradation, and volatilization. Data regarding production and use, environmental fate, and environmental distribution are presented for eight groups of anthropogenic organic compounds.

  2. Biogeochemical processes governing exposure and uptake of organic pollutant compounds in aquatic organisms

    SciTech Connect

    Farrington, J.W. )

    1991-01-01

    This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of entering ecosystems, and their physical chemical forms are discussed. Important factors that influence bioavailability and disposition (e.g., organism-water partitioning, uptake via food, food web transfer) are reviewed. These factors included solubilities of chemicals; partitioning of chemicals between solid surfaces, colloids, and soluble phases; variables rates of sorption, desorption; and physiological status of organism. It appears that more emphasis on considering food as a source of uptake and bioaccumulation is important in benthic and epibenthic ecosystems when sediment-associated pollutants are a significant source of input to an aquatic ecosystem. Progress with mathematical models for exposure and uptake of contaminant chemicals is discussed briefly.

  3. Organic colloid as a mode of transport for toxic halogenated organic compounds in the Mississippi river

    SciTech Connect

    Rostad, C.E.

    1995-12-01

    Suspended material was isolated from water samples from sixteen sites on the Mississippi River and its major tributaries from Minneapolis, Minn., to New Orleans, La., during the summer and fall of 1991 and the spring of 1992. The suspended material was separated into silt and colloid fractions in order to determine the proportion of associated toxic hydrophobic halogenated organic compounds transported on the colloid. The silt fraction (63 {mu}m to 1 {mu}m in diameter) was isolated first by centrifugation, then the colloidal fraction (1 {mu}m to 0.005 {mu}m in diameter) was isolated by tangential-flow ultrafiltration. The colloid averaged about 10 percent by weight of the total suspended material. Organic carbon content of the colloid ranged from 7 to 30 percent by weight. Silt organic carbon content ranged from 2 to 5 percent by weight. The proportion of suspended organic carbon transport in the river associated with the colloids averaged 35 percent of the total suspended organic carbon transport. Toxic halogenated organic compounds associated with both fractions included PCBs, chlordane, DCPA, hexachlorobenzene, and trifluralin. In some cases, transport of these compounds by the colloid fraction in the Mississippi River was greater than by the silt fraction.

  4. Biogeochemical processes governing exposure and uptake of organic pollutant compounds in aquatic organisms.

    PubMed Central

    Farrington, J W

    1991-01-01

    This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of entering ecosystems, and their physical chemical forms are discussed. Important factors that influence bioavailability and disposition (e.g., organism-water partitioning, uptake via food, food web transfer) are reviewed. These factors include solubilities of chemicals; partitioning of chemicals between solid surfaces, colloids, and soluble phases; variables rates of sorption, desorption; and physiological status of organism. It appears that more emphasis on considering food as a source of uptake and bioaccumulation is important in benthic and epibenthic ecosystems when sediment-associated pollutants are a significant source of input to an aquatic ecosystem. Progress with mathematical models for exposure and uptake of contaminant chemicals is discussed briefly. PMID:1904812

  5. Emissions and Secondary Organic Aerosol Production from Semivolatile and Intermediate Volatility Organic Compounds

    NASA Astrophysics Data System (ADS)

    Robinson, A. L.; Presto, A. A.; Miracolo, M. A.; Donahue, N. M.; Kroll, J. H.; Worsnop, D. R.

    2008-12-01

    Organic aerosols are a highly-dynamic system dominated by both variable gas-particle partitioning and chemical evolution. Important classes of organics include semivolatile and intermediate volatility organic compounds (SVOC and IVOC, respectively). SVOCs are compounds that exist in both the gas and particle phases at typical atmospheric conditions while IVOC are low-volatility vapors that exist exclusively in the gas phase. Both classes have saturation concentrations that are orders of magnitude lower than volatile organic compounds (VOC) that are the traditional subjects of atmosphere chemistry, such as monoterpenes, alkyl benzenes, etc. The SVOC and IVOC are poorly represented for in current atmospheric chemistry models. Source testing indicates that SVOC and IVOC emissions from biomass combustion, diesel engines and other sources exceed the primary organic aerosol emissions; thus the oxidation of these vapors could serve as a significant source of organic aerosol in the atmosphere. The formation of secondary organic aerosol (SOA) from the reactions between OH radicals and SVOCs and IVOCs was investigated in the Carnegie Mellon University smog chamber. Experiments were conducted with n-alkanes and emission surrogates (diesel fuel and lubricating oil). SVOC oxidation produces oxidized organic aerosol but little new organic aerosol mass. This behavior can be explained by the coupled effects of partitioning and aging. Oxidation of SVOC vapors creates low volatility species that partition into the condensed phase; this oxidation also reduces the SVOC vapor concentration which, in turn, requires particle-phase SVOC to evaporate to maintain phase equilibrium. In contrast, oxidation of IVOC results in sustained production of SOA consistent with a reaction with relatively slow kinetics and high mass yield. Aerosol Mass Spectrometer data indicates that the SOA formed from IVOC has a mass spectrum that is quite similar to the oxygenated organic aerosol factor observed in

  6. Microbial community response to addition of polylactate compounds to stimulate hexavalent chromium reduction in groundwater.

    PubMed

    Brodie, Eoin L; Joyner, Dominique C; Faybishenko, Boris; Conrad, Mark E; Rios-Velazquez, Carlos; Malave, Josue; Martinez, Ramon; Mork, Benjamin; Willett, Anna; Koenigsberg, Steven; Herman, Donald J; Firestone, Mary K; Hazen, Terry C

    2011-10-01

    To evaluate the efficacy of bioimmobilization of Cr(VI) in groundwater at the Department of Energy Hanford site, we conducted a series of microcosm experiments using a range of commercial electron donors with varying degrees of lactate polymerization (polylactate). These experiments were conducted using Hanford Formation sediments (coarse sand and gravel) immersed in Hanford groundwater, which were amended with Cr(VI) and several types of lactate-based electron donors (Hydrogen Release Compound, HRC; primer-HRC, pHRC; extended release HRC) and the polylactate-cysteine form (Metal Remediation Compound, MRC). The results showed that polylactate compounds stimulated an increase in bacterial biomass and activity to a greater extent than sodium lactate when applied at equivalent carbon concentrations. At the same time, concentrations of headspace hydrogen and methane increased and correlated with changes in the microbial community structure. Enrichment of Pseudomonas spp. occurred with all lactate additions, and enrichment of sulfate-reducing Desulfosporosinus spp. occurred with almost complete sulfate reduction. The results of these experiments demonstrate that amendment with the pHRC and MRC forms result in effective removal of Cr(VI) from solution most likely by both direct (enzymatic) and indirect (microbially generated reductant) mechanisms.

  7. Protective effects of novel organic selenium compounds against oxidative stress in the nematode Caenorhabditis elegans

    PubMed Central

    Stefanello, Sílvio Terra; Gubert, Priscila; Puntel, Bruna; Mizdal, Caren Rigon; de Campos, Marli Matiko Anraku; Salman, Syed M.; Dornelles, Luciano; Avila, Daiana Silva; Aschner, Michael; Soares, Félix Alexandre Antunes

    2015-01-01

    Organic selenium compounds possess numerous biological properties, including antioxidant activity. Yet, the high toxicity of some of them, such as diphenyl diselenide (DPDS), is a limiting factor in their current usage. Accordingly, we tested four novel organic selenium compounds in the non-parasite nematode Caenorhabditis elegans and compared their efficacy to DPDS. The novel organic selenium compounds are β-selenoamines (1-phenyl-3-(p-tolylselanyl)propan-2-amine (C1) and 1-(2-methoxyphenylselanyl)-3-phenylpropan-2-amine (C2) and analogs of DPDS (1,2-bis (2-methoxyphenyl) diselenide (C3) and 1,2-bisp-tolyldiselenide (C4). Synchronized worms at the L4 larval stage were exposed for one hour in M9 buffer to these compounds. Oxidative stress conditions were induced by juglone (200 μM) and heat shock (35 °C). Moreover, we evaluated Caenorhabditis elegans behavior, GST-4::GFP (glutathione S-transferase) expression and the activity of acetylcholinesterase (AChE). All tested compounds efficiently restored viability in juglone stressed worms. However, DPDS, C2, C3 and C4 significantly decreased the defecation cycle time. Juglone-induced GST-4::GFP expression was not attenuated in worms pretreated with the novel compounds, except with C2. Finally, AChE activity was reduced by DPDS, C2, C3 and C4. To our knowledge, this is study firstly showed the effects of C1, C2, C3 and C4 selenium-derived compounds in Caenorhabditis elegans. Low toxic effects were noted, except for reduction in the defecation cycle, which is likely associated with AChE inhibition. The juglone-induced stress (reduced viability) was fully reversed by compounds to control animal levels. C2 was also efficient in reducing the juglone-induced GST-4::GFP expression, suggesting the latter may mediate the stress induced by this compound. Future studies could be profitably directed at addressing additional molecular mechanisms that mediate the protective effects of these novel organic selenium compounds. PMID

  8. Removal of gasoline volatile organic compounds via air biofiltration

    SciTech Connect

    Miller, R.S.; Saberiyan, A.G.; Esler, C.T.; DeSantis, P.; Andrilenas, J.S.

    1995-12-31

    Volatile organic compounds (VOCs) generated by vapor extraction and air-stripping systems can be biologically treated in an air biofiltration unit. An air biofilter consists of one or more beds of packing material inoculated with heterotrophic microorganisms capable of degrading the organic contaminant of concern. Waste gases and oxygen are passed through the inoculated packing material, where the microorganisms will degrade the contaminant and release CO{sub 2} + H{sub 2}O. Based on data obtained from a treatability study, a full-scale unit was designed and constructed to be used for treating gasoline vapors generated by a vapor-extraction and groundwater-treatment system at a site in California. The unit is composed of two cylindrical reactors with a total packing volume of 3 m{sup 3}. Both reactors are packed with sphagnum moss and inoculated with hydrocarbon-degrading microorganisms of Pseudomonas and Arthrobacter spp. The two reactors are connected in series for air-flow passage. Parallel lines are used for injection of water, nutrients, and buffer to each reactor. Data collected during the startup program have demonstrated an air biofiltration unit with high organic-vapor-removal efficiency.

  9. Metabolism and effects of organic compounds in animals

    SciTech Connect

    Eisele, G.R.

    1985-10-01

    The knowledge of the metabolism and effects of organic compounds in animals, specifically food-producing animals, are of paramount importance in assessing potential human health hazards. An intensive effort has been directed at detection of chemicals in the environment, determination of their physiological insult and cellular interaction; in particular their carcinogenic and mutagenic induction capability. The chemical exposure of food-producing animals can be extremely difficult to evaluate and quite devastating. The exposure of food-producing animals to polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) emphasizes the seriousness of the problem. The polycyclic aromatic hydrocarbons (PAHs), capable of inducing cancer in experimental animals, have been studied extensively in laboratory animals. Current studies deal with the mechanism of metabolism of PAHs and the ultimate carcinogenic form. Although our knowledge concerning the health hazards of organic chemicals is continually increasing, its impact on food-producing animals and man's food chain is poorly understood. Awareness of the problem by practicing veterinarians and toxicologists, environmental toxicologists and public health officials is required to evaluate the impact of organic chemicals on the human food chain. 6 references.

  10. Influence of Biodegradation on the Organic Compounds Composition of Peat.

    NASA Astrophysics Data System (ADS)

    Serebrennikova, Olga; Svarovskaya, Lidiya; Duchko, Maria; Strelnikova, Evgeniya; Russkikh, Irina

    2016-06-01

    Largest wetland systems are situated on the territory of the Tomsk region. They are characterized by the high content of organic matter (OM), which undergoes transformation as a result of physical, chemical and biological processes. The composition of peat OM is determined by the nature of initial peat-forming plants, their transformation products and bacteria. An experiment in stimulated microbial impact was carried out for estimating the influence of biodegradation on the composition of peat lipids. The composition of the functional groups in the bacterial biomass, initial peat and peat after biodegradation was determined by IR-spectroscopy using the spectrometer NICOLET 5700. The IR spectra of peat and bacteria organic matter are characterized by the presence of absorption bands in ranges: 3400-3200 cm-1, which refers to the stretching vibrations of OH-group of carboxylic acids and various types of hydrogen bonds; 1738-1671 cm-1 - characteristic stretching vibrations of the C = O group of carboxylic acids and ketones; 1262 cm-1 - stretching vibrations of C-O of carboxylic acids. Group and individual composition of organic compounds in studied samples was determined by gas chromatography-mass-spectrometry.

  11. Mechanisms on electrical breakdown strength increment of polyethylene by aromatic carbonyl compounds addition: a theoretical study.

    PubMed

    Zhang, Hui; Shang, Yan; Wang, Xuan; Zhao, Hong; Han, Baozhong; Li, Zesheng

    2013-12-01

    A theoretical investigation is accomplished on the mechanisms of electrical breakdown strength increment of polyethylene at the atomic and molecular levels. It is found that the addition of aromatic carbonyl compounds as voltage stabilizers is one of the important factors for increasing electrical breakdown strength of polyethylene, as the additives can trap hot electrons, obtain energy of hot electrons, and transform the aliphatic cation to relatively stable aromatic cation to prevent the degradation of the polyethylene matrix. The HOMO-LUMO energy gaps (E(g)), the ionization potentials (IPs), and electron affinities (EAs) at the ground states of a series of aromatic carbonyl compounds are obtained at the B3LYP/6-311+G(d,p) level. The theoretical results are in good agreement with the available experimental findings, show that 2,4-dioctyloxybenzophenone (Bzo) and 4,4'-didodecyloxybenzil (Bd) molecules can effectively increase the electrical breakdown strength when they are doped into polyethylene because of their much smaller E g values than all the other studied aromatic carbonyl molecules and excellent compatibility with polymers matrix.

  12. Nitrogen Containing Organic Compounds and Oligomers in Secondary Organic Aerosol Formed by Photooxidation of Isoprene

    SciTech Connect

    Nguyen, Tran B.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei

    2011-07-06

    Electrospray ionization high-resolution mass spectrometry (ESI HR-MS) was used to probe molecular structures of oligomers in secondary organic aerosol (SOA) generated in laboratory experiments on isoprene photooxidation at low- and high-NOx conditions. Up to 80-90% of the observed products are oligomers and up to 33% are nitrogen-containing organic compounds (NOC). We observe oligomers with up to 8 monomer units in length. Tandem mass spectrometry (MSn) confirms NOC compounds are organic nitrates and elucidates plausible chemical building blocks contributing to oligomer formation. Most organic nitrates are comprised of methylglyceric acid units. Other important multifunctional C2-C5 monomer units are identified including methylglyoxal, hydroxyacetone, hydroxyacetic acid, glycolaldehyde, and 2-methyltetrols. The majority of the NOC oligomers contain only one nitrate moiety resulting in a low average N:C ratio of 0.019. Average O:C ratios of the detected SOA compounds are 0.54 under the low-NOx conditions and 0.83 under the high-NOx conditions. Our results underscore the importance of isoprene photooxidation as a source of NOC in organic particulate matter.

  13. Mineral and organic compounds in leachate from landfill with concentrate recirculation.

    PubMed

    Talalaj, Izabela Anna

    2015-02-01

    The effect of a reverse osmosis concentrate recirculation on the mineral and organic compounds in a landfill leachate was investigated. Investigated was the quality of a leachate from two landfills operated for different periods (a 20-year-old Cell A and a 1-year-old Cell B), where the concentrate was recirculated. Examined were general parameters (conductivity, pH), organic compounds (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic nitrogen, BOD/COD), and inorganic compounds (nitrogen ammonia, sulfite, sulfate, cyanide, boron, chloride, ferrous, zinc, chrome, copper). The findings from the first year of investigation showed that over the initial period of recirculation, the concentration of organic compounds (BOD, COD) increased, but after 6 months their values stabilized. It indicates that the concentrate recirculation accelerated organic decomposition, especially in the new landfill Cell. The analysis of inorganic parameters showed that recirculation landfills produce a leachate with a higher concentration of N-NH4, and Cl(-). In case of the old landfill Cell, an increase in B and Fe was also noticeable. These compounds are cyclically washed out from a waste dump and require an additional pretreatment in order to exclude them from recirculation cycle. The increased concentration of Cu, Zn, and Fe was noticed during the initial months of recirculation and in the season of intense atmospheric precipitation in the leachate from both Cells. Higher values of electro conductivity, Cl(-), N-NH4 (+), B, and Fe in the leachate from the old field indicate that the attenuation capacity of this landfill is close to exhaustion.

  14. Mineral and organic compounds in leachate from landfill with concentrate recirculation.

    PubMed

    Talalaj, Izabela Anna

    2015-02-01

    The effect of a reverse osmosis concentrate recirculation on the mineral and organic compounds in a landfill leachate was investigated. Investigated was the quality of a leachate from two landfills operated for different periods (a 20-year-old Cell A and a 1-year-old Cell B), where the concentrate was recirculated. Examined were general parameters (conductivity, pH), organic compounds (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic nitrogen, BOD/COD), and inorganic compounds (nitrogen ammonia, sulfite, sulfate, cyanide, boron, chloride, ferrous, zinc, chrome, copper). The findings from the first year of investigation showed that over the initial period of recirculation, the concentration of organic compounds (BOD, COD) increased, but after 6 months their values stabilized. It indicates that the concentrate recirculation accelerated organic decomposition, especially in the new landfill Cell. The analysis of inorganic parameters showed that recirculation landfills produce a leachate with a higher concentration of N-NH4, and Cl(-). In case of the old landfill Cell, an increase in B and Fe was also noticeable. These compounds are cyclically washed out from a waste dump and require an additional pretreatment in order to exclude them from recirculation cycle. The increased concentration of Cu, Zn, and Fe was noticed during the initial months of recirculation and in the season of intense atmospheric precipitation in the leachate from both Cells. Higher values of electro conductivity, Cl(-), N-NH4 (+), B, and Fe in the leachate from the old field indicate that the attenuation capacity of this landfill is close to exhaustion. PMID:25194843

  15. Study on photocatalytic degradation of several volatile organic compounds.

    PubMed

    Zuo, Guo-Min; Cheng, Zhen-Xing; Chen, Hong; Li, Guo-Wen; Miao, Ting

    2006-02-01

    The gas-phase photolytic and photocatalytic reactions of several aromatics and chlorohydrocarbons were investigated. The experimental results revealed that chlorohydrocarbons like trichloroethylene, dichloromethane and chloroform could be degraded through either photolysis or photocatalysis under irradiation of germicidal lamp, and the elimination rate of chlorohydrocarbons through photolysis was quicker than that through photocatalysis. UV light from a germicidal lamp could directly lead to degradation of toluene but could hardly act on benzene. The photodegradation rate for these volatile organic compounds (VOCs) through photolysis followed an order: trichloroethylene>chloroform>dichloromethane>toluene>benzene>carbon tetrachloride, and through photocatalysis followed: trichloroethylene>chloroform>toluene>dichloromethane>benzene>carbon tetrachloride. Besides, a series of modified TiO2 photocatalysts were prepared by depositing noble metal, doping with transition metal ion, recombining with metal oxides and modifying with super strong acid. Activity of these catalysts was examined upon photocatalytic degradation of benzene as a typical compound that was hard to be degraded. It indicated that these modification methods could promote the activity of TiO2 catalyst to different extent. The apparent zero-order reaction rate constant for degrading benzene over SnO2/TiO2 catalyst had the highest value, which was nearly three times as that over P25 TiO2. But it simultaneously had the lowest rate for mineralizing the objective compound. In spite that Fe3+/TiO2 catalyst behaved slightly less active than SnO2/TiO2 for degradation of benzene, the mineralization rate over Fe3+/TiO2 was the highest one among the prepared catalysts.

  16. Sulfate Minerals: A Problem for the Detection of Organic Compounds on Mars?

    PubMed Central

    Watson, Jonathan S.; Najorka, Jens; Luong, Duy; Sephton, Mark A.

    2015-01-01

    Abstract The search for in situ organic matter on Mars involves encounters with minerals and requires an understanding of their influence on lander and rover experiments. Inorganic host materials can be helpful by aiding the preservation of organic compounds or unhelpful by causing the destruction of organic matter during thermal extraction steps. Perchlorates are recognized as confounding minerals for thermal degradation studies. On heating, perchlorates can decompose to produce oxygen, which then oxidizes organic matter. Other common minerals on Mars, such as sulfates, may also produce oxygen upon thermal decay, presenting an additional complication. Different sulfate species decompose within a large range of temperatures. We performed a series of experiments on a sample containing the ferric sulfate jarosite. The sulfate ions within jarosite break down from 500°C. Carbon dioxide detected during heating of the sample was attributed to oxidation of organic matter. A laboratory standard of ferric sulfate hydrate released sulfur dioxide from 550°C, and an oxygen peak was detected in the products. Calcium sulfate did not decompose below 1000°C. Oxygen released from sulfate minerals may have already affected organic compound detection during in situ thermal experiments on Mars missions. A combination of preliminary mineralogical analyses and suitably selected pyrolysis temperatures may increase future success in the search for past or present life on Mars. Key Words: Mars—Life detection—Geochemistry—Organic matter—Jarosite. Astrobiology 15, 247–258. PMID:25695727

  17. Catabolism of volatile organic compounds influences plant survival.

    PubMed

    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.

  18. PDMS-coated fiber volatile organic compounds sensors.

    PubMed

    Ning, Xiangping; Yang, Jingyi; Zhao, Chun Liu; Chan, Chi Chiu

    2016-05-01

    The functionality of poly(dimethylsiloxane) (PDMS)-based interferometric fiber sensors for volatile organic compounds (VOCs) detection is investigated and experimentally demonstrated. Two interferometric configurations are considered in this work, namely Fabry-Perot (FP) and Sagnac interferometers (SI). Both sensors are functionalized with a thin layer of VOC-sensitive polymer: PDMS, whose degree of swelling varies as a function of VOC concentrations. This swelling effect will result in an optical path length and birefringence modulation for FP and SI sensors, respectively. In this paper, the two common VOCs, ethanol and 2-propanol, were detected by the proposed sensor and the inverse matrix method was used to differentiate the VOC in gas mixture.

  19. Imaging subsurface geology and volatile organic compound plumes

    SciTech Connect

    Qualheim, B.J.; Daley, P.F.; Johnson, V.; McPherrin, R.V.; Laguna, G.

    1992-03-01

    Lawrence Livermore National Laboratory (LLNL) (Fig. 1) is in the final stages of the Superfund decisionmaking process for site remediation and restoration. In the process of characterizing the subsurface of the LLNL site, we have developed unique methods of collecting, storing, retrieving, and imaging geologic and chemical data from more than 350 drill holes. The lateral and vertical continuity of subsurface paleostream channels were mapped for the entire LLNL site using geologic descriptions from core samples, cuttings, and interpretations from geophysical logs. A computer-aided design and drafting program, SLICE, written at LLNL, was used to create two-dimensional maps of subsurface sediments, and state-of-the-art software produced three-dimensional images of the volatile organic compound (VOC) plumes using data from water and core fluid analyses.

  20. Growth Yields of Bacteria on Selected Organic Compounds

    PubMed Central

    Mayberry, W. R.; Prochazka, G. J.; Payne, W. J.

    1967-01-01

    Cell yields were determined for two bacterial soil isolants grown aerobically in minimal media on a variety of synthetic organic compounds. 1-Dodecanol, benzoic acid, phenylacetic acid, phenylglyoxylic acid, and diethylene, triethylene, and tetraethylene glycols were tested. Two “biochemicals,” succinate and acetate, were also tested for comparison. Yields were calculated on the basis of grams of cells obtained per mole of substrate utilized, gram atom of carbon utilized, mole of oxygen consumed, and equivalent of “available electrons” in the substrates. This latter value appears to be nearly constant at 3 g of cells per equivalent of “available electrons.” Yields predicted on this basis for other bacteria and for yeasts on other substrates are in fair agreement with reported values. PMID:16349741

  1. Source apportionment of ambient volatile organic compounds in Beijing.

    PubMed

    Song, Yu; Shao, Min; Liu, Ying; Lu, Sihua; Kuster, William; Goldan, Paul; Xie, Shaodong

    2007-06-15

    The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing. PMID:17626435

  2. Detection of volatile organic compounds using surface enhanced Raman scattering

    SciTech Connect

    Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

    2012-03-22

    The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

  3. Organic waste compounds as contaminants in Milwaukee-area streams

    USGS Publications Warehouse

    Baldwin, Austin K.; Corsi, Steven R.; Magruder, Christopher; Magruder, Matthew; Bruce, Jennifer L.

    2015-09-22

    Organic waste compounds (OWCs) are ingredients and by-products of common agricultural, industrial, and household substances that can contaminate our streams through sources like urban runoff, sewage overflows, and leaking septic systems. To better understand how OWCs are affecting Milwaukee-area streams, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District, conducted a three-year study to investigate the presence and potential toxicity of 69 OWCs in base flow, stormflow, pore water, and sediment at 14 stream sites and 3 Milwaukee harbor locations. This fact sheet summarizes the major findings of this study, including detection frequencies and concentrations, potential toxicity, the prevalence of polycyclic aromatic hydrocarbons (PAHs), and the influence of urbanization.

  4. Hybrid energy storage systems utilizing redox active organic compounds

    SciTech Connect

    Wang, Wei; Xu, Wu; Li, Liyu; Yang, Zhenguo

    2015-09-08

    Redox flow batteries (RFB) have attracted considerable interest due to their ability to store large amounts of power and energy. Non-aqueous energy storage systems that utilize at least some aspects of RFB systems are attractive because they can offer an expansion of the operating potential window, which can improve on the system energy and power densities. One example of such systems has a separator separating first and second electrodes. The first electrode includes a first current collector and volume containing a first active material. The second electrode includes a second current collector and volume containing a second active material. During operation, the first source provides a flow of first active material to the first volume. The first active material includes a redox active organic compound dissolved in a non-aqueous, liquid electrolyte and the second active material includes a redox active metal.

  5. PDMS-coated fiber volatile organic compounds sensors.

    PubMed

    Ning, Xiangping; Yang, Jingyi; Zhao, Chun Liu; Chan, Chi Chiu

    2016-05-01

    The functionality of poly(dimethylsiloxane) (PDMS)-based interferometric fiber sensors for volatile organic compounds (VOCs) detection is investigated and experimentally demonstrated. Two interferometric configurations are considered in this work, namely Fabry-Perot (FP) and Sagnac interferometers (SI). Both sensors are functionalized with a thin layer of VOC-sensitive polymer: PDMS, whose degree of swelling varies as a function of VOC concentrations. This swelling effect will result in an optical path length and birefringence modulation for FP and SI sensors, respectively. In this paper, the two common VOCs, ethanol and 2-propanol, were detected by the proposed sensor and the inverse matrix method was used to differentiate the VOC in gas mixture. PMID:27140369

  6. Laboratory methods for volatile organic compounds evolved in mineralization studies

    SciTech Connect

    Hickey, W.J.; Arnold, S.M.; Moran, B.N.

    1995-11-01

    A system to study mineralization of volatile organic compounds (VOCs) was developed using commercially available solid-phase VOC traps and impingers to collect CO{sub 2} as well as VOCs breaking out from the solid-phase trap. The efficiencies of VOC traps containing activated charcoal (AC) or graphitized carbon black (GCB) for absorbing [{sup 14}C]trichloroethylene ([{sup 14}C]TCE) and {sup 14}CO{sub 2} were evaluated, and approaches for minimizing VOC losses from reaction vessels were established. Mass balances showed AC and GCB absorbed similar amounts of [{sup 14}C]TCE. However, GCB had no detectable {sup 14}CO{sub 2} retention, whereas AC absorbed about 7% of the {sup 14}CO{sub 2}. Because {sup 14}CO{sub 2} absorption could influence the interpretation of mineralization experiments, GCB was concluded to be the better VOC-trapping matrix.

  7. Transport of organic compounds in thermoplastic geomembranes. 1: Mathematical model

    SciTech Connect

    Park, J.K.; Hoopes, J.A.; Sakti, J.P.

    1996-09-01

    A quasi-two-dimensional partition-diffusion transport model was developed to determine the diffusion coefficient and partition coefficient for various types of geomembranes from measurements of aqueous organic compound concentrations in a confined, double-compartment apparatus with a geomembrane separating the two compartments. The geomembranes tested were high-density polyethylene (HDPE), very low-density polyethylene (VLDPE), and polyvinyl chloride (PVC) and the permeants were mixtures of methylene chloride, toluene, trichloroethylene (TCE), and m-xylene at 10--100 mg/L. The diffusion coefficient increased exponentially was unaffected by compound concentration and membrane thickness. As HDPE geomembranes had stretched by 5% of their original length, the partition coefficient increased by 0.15--0.6 times. VLDPE had 1.8--3.3 times greater partition coefficients and 1.6--2.8 times greater diffusion coefficients than HDPE, while PVC had 6.2--8.3 times greater partition coefficients and 1--1.8 times greater diffusion coefficients than HDPE.

  8. Sorption of hydrophobic organic compounds (HOC) in rapeseed oil bodies.

    PubMed

    Boucher, J; Cengelli, F; Trumbic, D; Marison, I W

    2008-02-01

    Oil-bodies are minute plant organelles (0.5-2.0microm diameter) consisting of an oil core surrounded by a phospholipid monolayer/proteinaceous membrane. Oil-bodies have been isolated from rapeseed seeds and demonstrated to constitute a novel type of micro-capsule suitable for the extraction of hydrophobic organic compounds from aqueous environments. Three hydrophobic pesticides: atrazine (2-chlor-4-ethyl-amino-6-isopropylamino-1,3,5-triazine), carbaryl (1-naphthyl methylcarbamate) and parathion (O,O-diethyl O-(4-nitrophenyl) phosphorothioate), as well as naphthalene and 2-phenylethanol were successfully extracted from aqueous solutions, with absorption in the inner oily core of OB as sorption mechanism. The OB membrane does not represent a barrier for the mass transfer of the compound towards the inner oily core of OB. Moreover, due to very high surface area to volume ratio, oil-bodies exhibit very good mass transfer properties compared with larger synthetic microcapsules or two-phase liquid-liquid extraction (LLE) techniques, which diminishes the need for strong agitation and avoids the formation of difficult to separate stable emulsions.

  9. Indoor carpet as an adsorptive reservoir for volatile organic compounds

    SciTech Connect

    Won, D.; Corsi, R.L.; Rynes, M.

    1999-07-01

    Carpet is recognized as a potential source of volatile organic compounds (VOCs) in indoor air. However, carpet systems can also serve as adsorptive sinks with the potential for reductions in peak VOC concentrations and subsequent re-emission of VOCs over prolonged periods of time. A series of experiments involving eight VOCs, and several carpet systems and environmental conditions were completed using a set of parallel chambers to characterize carpet systems as sinks of VOCs. A linear adsorption and desorption model was used to describe interactions between VOCs and carpet. New carpet fibers treated with stain protection generally accounted for only a very small fraction of mass sorbed to carpet. Most of the sorbed mass for carpet systems was accounted for by either the underlying pad or a combination of the pad and structural backing. Methyl-tert-butyl ether (MTBE) was the only compound to exhibit greater sorption to nylon fibers than to other carpet components. Vapor pressure was observed to be one of the properties that can be related to sorption parameters. Variations in relative humidity (RH) had a significant effect on the degree of sorption for a highly soluble VOC (isopropanol). However, RH had no apparent effect on other VOCs. Air exchange rates (0.5, 2.1, 3.2 /hr) and inlet concentrations (2.5, 5, 15 ppm) generally had little effect on sorption.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Precipitation of organic arsenic compounds and their degradation products during struvite formation.

    PubMed

    Lin, Jin-Biao; Yuan, Shoujun; Wang, Wei; Hu, Zhen-Hu; Yu, Han-Qing

    2016-11-01

    Roxarsone (ROX) and arsanilic acid (ASA) have been extensively used as organoarsenic animal feed additives. Organic arsenic compounds and their degradation products, arsenate (As(V)) and arsenite (As(III)), exist in the effluent from anaerobic reactors treating animal manure contaminated by ROX or ASA with ammonium (NH4(+)-N) and phosphate (PO4(3-)-P) together. Therefore, arsenic species in the effluent might be involved in the struvite formation process. In this study, the involvement of organic arsenic compounds and their degradation products As(V) and As(III) in the struvite crystallization was investigated. The results demonstrated that arsenic compounds did not substantially affect the PO4(3-)-P recovery, but confirmed the precipitation of arsenic during struvite formation. The precipitation of arsenic compounds in struvite was considerably affected by a solution pH from 9.0 to 11.0. With an increase in pH, the content of ASA and ROX in the precipitation decreased, but the contents of As(III) and As(V) increased. In addition, the arsenic content of As(V) in the struvite was higher than that of As(III), ASA and ROX. The results indicated that the struvite could be contaminated when the solution contains arsenic species, but that could be minimized by controlling the solution pH and maintaining anaerobic conditions during struvite formation. PMID:27262276

  12. Spatial variability of volatile organic compounds in streams on Long Island, New York, and in New Jersey

    USGS Publications Warehouse

    O'Brien, Anne K.; Reiser, Robert G.; Gylling, Helle

    1997-01-01

    Volatile organic compounds (VOCs) are found in almost all natural and synthetic materials and are commonly used in fuels, fuel additives, solvents, perfumes, flavor additives, and deodorants. Potential health hazards and environmental degradation resulting from the widespread use of VOCs has prompted increasing concern among scientists, industry, and the general public.

  13. The identification of polar organic compounds found in consumer products and their toxicological properties.

    PubMed

    Cooper, S D; Raymer, J H; Pellizzari, E D; Thomas, K W

    1995-01-01

    Exposure to volatile organic compounds (VOCs) in the indoor environment has received substantial research attention in the past several years, with the goal of better understanding the impact of such exposures on human health and well-being. Many VOCs can arise from consumer products used within the indoor environment. The VOCs emitted from five representative consumer products were collected onto Tenax-GC and subjected to thermal desorption and analysis by gas chromatography, in combination with low-resolution mass spectrometry (MS), high-resolution MS, and matrix-isolation Fourier transform infrared spectroscopy for structural characterization. An emphasis was placed on the polar organic compounds often used to provide fragrance in these products. The structures of a number of these compounds were confirmed, and an electronic literature search was carried out on them to determine any known toxic properties. The search revealed that many of the VOCs possess toxic properties when studied at acute, relatively high-level exposures. In addition, toxic effects were reported for a few of the chemicals, such as benzaldehyde, alpha-terpineol, benzyl acetate, and ethanol, at relatively low dose levels of 9-14 mg/kg. In general, the data were unclear as to the effect of chronic, low-level exposures. The widespread use of such chemicals suggests that the health effects of chronic exposures need to be determined. Validated analytical methods for the quantitative characterization of polar organic compounds at low concentrations will be required to make such work possible.

  14. Organic Compounds in Truckee River Water Used for Public Supply near Reno, Nevada, 2002-05

    USGS Publications Warehouse

    Thomas, Karen A.

    2009-01-01

    Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including, in part, pesticides, solvents, gasoline hydrocarbons, personal care and domestic-use products, and refrigerants and propellants. Of 258 compounds measured, 28 were detected in at least 1 source water sample collected approximately monthly during 2002-05 at the intake of the Chalk Bluff Treatment Plant, on the Truckee River upstream of Reno, Nevada. The diversity of compounds detected indicate various sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including point sources from treated wastewater outfalls upstream of the sampling location, overland runoff, and groundwater discharge) to drinking-water supply intakes. Three compounds were detected in more than 20 percent of the source-water intake samples at low concentrations (less than 0.1 microgram per liter), including caffeine, p-cresol (a wood preservative), and toluene (a gasoline hydrocarbon). Sixteen of the 28 compounds detected in source water also were detected in finished water (after treatment, but prior to distribution; 2004-05). Additionally, two disinfection by-products not detected in source water, bromodichloromethane and dibromochloromethane, were detected in all finished water samples. Two detected compounds, cholesterol and 3-beta-coprostanol, are among five naturally occurring biochemicals analyzed in this study. Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the compounds. Seven compounds (toluene, chloroform, bromodichloromethane, dibromodichloromethane, bisphenol A, cholesterol, and 3-beta-coprostanol) were measured at concentrations greater than 0.1 microgram per liter. On the basis of this screening-level assessment, adverse effects to human health are

  15. Description, Properties, and Degradation of Selected Volatile Organic Compounds Detected in Ground Water--A Review of Selected Literature

    USGS Publications Warehouse

    Lawrence, Stephen J.

    2006-01-01

    This report provides abridged information describing the most salient properties and biodegradation of 27 chlorinated volatile organic compounds detected during ground-water studies in the United States. This information is condensed from an extensive list of reports, papers, and literature published by the U.S. Government, various State governments, and peer-reviewed journals. The list includes literature reviews, compilations, and summaries describing volatile organic compounds in ground water. This report cross-references common names and synonyms associated with volatile organic compounds with the naming conventions supported by the International Union of Pure and Applied Chemistry. In addition, the report describes basic physical characteristics of those compounds such as Henry's Law constant, water solubility, density, octanol-water partition (log Kow), and organic carbon partition (log Koc) coefficients. Descriptions and illustrations are provided for natural and laboratory biodegradation rates, chemical by-products, and degradation pathways.

  16. Compositions of volatile organic compounds emitted from melted virgin and waste plastic pellets.

    PubMed

    Yamashita, Kyoko; Yamamoto, Naomichi; Mizukoshi, Atsushi; Noguchi, Miyuki; Ni, Yueyong; Yanagisawa, Yukio

    2009-03-01

    To characterize potential air pollution issues related to recycling facilities of waste plastics, volatile organic compounds (VOCs) emitted from melted virgin and waste plastics pellets were analyzed. In this study, laboratory experiments were performed to melt virgin and waste plastic pellets under various temperatures (150, 200, and 250 degrees C) and atmospheres (air and nitrogen [N2]). In the study presented here, low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS) and the recycled waste plastic pellets were used. The VOCs generated from each plastic pellets were collected by Tenax/Carboxen adsorbent tubes and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). The result showed the higher temperatures generated larger amounts of total VOCs (TVOCs). The VOCs emitted from the virgin plastic pellets likely originated from polymer degradation. Smaller TVOC emissions were observed in N2 atmosphere than in air atmosphere. In particular, larger amounts of the oxygenated compounds, which are generally hazardous and malodorous, were detected in air than in N2. In addition to the compounds originating from polymer degradation, the compounds originating from the plastic additives were also detected from LDPE and PS. Furthermore, various species of VOCs likely originating from contaminant inseparate polyvinyl chloride (PVC), food residues, cleaning agents, degreasers, and so on were detected from the waste plastic. Thus, melting waste plastics, as is conducted in recycling facilities, might generate larger amounts of potentially toxic compounds than producing virgin plastics.

  17. Photochemical Recycling of Hydrogen Peroxide on Snow in the Presence of Organic Compounds

    NASA Astrophysics Data System (ADS)

    Hullar, T.; Anastasio, C.

    2008-12-01

    Hydrogen peroxide (HOOH), an important tropospheric oxidant, is also present in polar ice cores and surface snow. In the presence of sunlight, HOOH in the photic zone of snow photolyzes to form hydroxyl radical (•OH), which can react with organics and other compounds in the snow to form a variety of products, including volatile compounds. Based on past reports, the photolytic lifetime of HOOH in polar surface snow during the summer is less than a month, yet ice core data shows that snowpack HOOH survives through the summer. Chemical reactions producing HOOH are known to exist in water drops and aerosol particles, but have not been studied in snow or ice matrices. Recycling of HOOH due to reactions with organic compounds may represent a significant source in polar snows. Our work evaluates the ability of organic compounds to recycle HOOH in water and ice matrices. The recycling of HOOH can occur through the following cycle: (1) HOOH is photolyzed to two molecules of •OH; (2) reaction of •OH with an organic molecule forms hydroperoxyl radical (HO2•), and (3) two HO2• combine to reform HOOH: •OH + organic → HO2• + products HO2• + HO2• → HOOH + O2 Our findings in solution (5° C) indicate that a variety of organic compounds recycle •OH back into HOOH; typically 10 to 60% of the HOOH that is photolyzed is recycled via this mechanism. For organic acids, decreases in solution pH increase the efficiency of HOOH production. Other organics have not shown pH dependent production rates. Organics studied have also shown direct photoformation of HOOH, although the contribution of this pathway to the overall HOOH concentration is minor compared to the recycling reaction. Evaluation of organics-mediated HOOH recycling in an ice matrix is underway, and will also be presented. Assuming recycling efficiencies in an ice matrix are similar to those in aqueous solution, HOOH recycling could be responsible for extending the lifetime of HOOH in polar snowpacks

  18. [Occurrence and distribution of volatile organic compounds in conventional and advanced drinking water treatment processes].

    PubMed

    Chen, Xi-Chao; Luo, Qian; Chen, Hu; Wei, Zi; Wang, Zi-Jian; Xu, Ke-Wen

    2013-12-01

    A series of experiments were conducted to study the occurrence and distribution of volatile organic compounds (VOCs) in conventional and advanced drinking water treatment processes of 3 water treatment plants in Lianyungang City. Results showed that 30 compounds of 3 classes were detected from 67 kinds of VOCs in all the samples collected. The concentrations of carbonyl compounds, halogenated hydrocarbons and benzenes detected were in the ranges of 0.04-61.27, 0.02-35.61 and 0.07-2.33 microg x L(-1) respectively. Comparing the changes of different VOCs in three drinking water treatment plants, conventional chlorination process could effectively remove benzenes but meanwhile produced trihalomethanes (THMs). Additional advanced treatment ozonation-biological activated carbon process could decrease the formation of THMs during pre-chlorination but produced new risky contaminants like carbonyl compounds. The changes of VOCs in tap water were also investigated. It was found that carbonyl compounds produced by ozonation could be further transformed to THMs with residual chlorine. However, the health risks of all detected compounds in tap water were at a low level, except that the carcinogenic risk of crotonaldehydes (9.3 x 10(-5)-2.2 x 10(-4)) was slightly higher than the US EPA threshold (10(-6)-10(-4)). PMID:24640902

  19. [Occurrence and distribution of volatile organic compounds in conventional and advanced drinking water treatment processes].

    PubMed

    Chen, Xi-Chao; Luo, Qian; Chen, Hu; Wei, Zi; Wang, Zi-Jian; Xu, Ke-Wen

    2013-12-01

    A series of experiments were conducted to study the occurrence and distribution of volatile organic compounds (VOCs) in conventional and advanced drinking water treatment processes of 3 water treatment plants in Lianyungang City. Results showed that 30 compounds of 3 classes were detected from 67 kinds of VOCs in all the samples collected. The concentrations of carbonyl compounds, halogenated hydrocarbons and benzenes detected were in the ranges of 0.04-61.27, 0.02-35.61 and 0.07-2.33 microg x L(-1) respectively. Comparing the changes of different VOCs in three drinking water treatment plants, conventional chlorination process could effectively remove benzenes but meanwhile produced trihalomethanes (THMs). Additional advanced treatment ozonation-biological activated carbon process could decrease the formation of THMs during pre-chlorination but produced new risky contaminants like carbonyl compounds. The changes of VOCs in tap water were also investigated. It was found that carbonyl compounds produced by ozonation could be further transformed to THMs with residual chlorine. However, the health risks of all detected compounds in tap water were at a low level, except that the carcinogenic risk of crotonaldehydes (9.3 x 10(-5)-2.2 x 10(-4)) was slightly higher than the US EPA threshold (10(-6)-10(-4)).

  20. Biodegradation of organic compounds sequestered in organic solids or in nanopores within silica particles

    SciTech Connect

    Hatzinger, P.B.; Alexander, M.

    1997-11-01

    A study was conducted using model solids to determine whether the time-dependent decline in availability for biodegradation of organic pollutants in soil might result from the entrapment of these compounds in porous or nonporous solids. A strain of Pseudomonas mineralized phenanthrene in solid alkanes containing 18 to 32 carbons, three waxes, and low-molecular-weight polycaprolactone, polyethylene, and polypropylene. The rates were appreciably slower than when the substrate was not initially present within these nonporous solids. From 1.4 to 63.4% of the polycyclic aromatic hydrocarbon added to the solids was mineralized in 90 d. The rates and extents of partitioning of phenanthrene varied markedly among the solids. The rates of partitioning and biodegradation of phenanthrene initially present in the alkanes were positively correlated. The bacterium rapidly and extensively mineralized phenanthrene provided in calcium alginate beads containing varying amounts of soluble soil organic matter. The rates and extents of phenanthrene mineralization declined as the percentage of the substrate in the nanopores within silica particles increased, but the reductions in rate, extent, or both were less pronounced than with nonporous solids. The rate of 4-nitrophenol biodegradation also declined with increasing percentages of the compound in these nanopores. The data are consistent with hypotheses that the sequestration and consequent decrease in bioavailability of organic compounds that persist in soil result from their partitioning into organic matter or their presence within nanopores in soil.

  1. Enhanced mineralization of organic compounds in nonaqueous-phase liquids

    SciTech Connect

    Labare, M.P.; Alexander, M.

    1995-11-01

    Biodegradation of phenanthrene, biphenyl, or di(2-ethylhexyl) phthalate initially present in a variety of nonaqueous-phase liquids (NAPLs) was slow in samples of soil and aquifer solids. The NAPLs were hexadecane, dibutyl phthalate, 2, 2, 4 ,4, 6, 8, 8-heptamethylnonane, cyclohexane, commercial oils, crude oil, creosote, and kerosene. Slurrying the soil or aquifer solids markedly enhanced the rate and extent of mineralization of the test compounds initially in many of the NAPLs. Both the low rate and extent of mineralization of the three compounds initially in dibutyl phthalate in soil slurries and of di(2- ethylhexyl) phthalate in heptamethylnonane present in slurries of aquifer solids were increased by inoculation of acclimated microbial cultures. Increasing the NAPL volume decreased phenanthrene biodegradation in soil, but the effect of larger NAPL volume could be alleviated by slurrying and inoculation. The rate or extent of mineralization in aquifer slurries of di(2-ethylhexyi) phthalate initially in some NAPLs was increased by addition of N and P, and inoculation further enhanced the degradation.

  2. Effect of water saturation in soil organic matter on the partition of organic compounds

    USGS Publications Warehouse

    Rutherford, D.W.; Chlou, G.T.

    1992-01-01

    The sorption of benzene, trichloroethylene, and carbon tetrachloride at room temperature from water solution and from vapor on two high-organic-content soils (peat and muck) was determined in order to evaluate the effect of water saturation on the solute partition in soil organic matter (SOM). The uptake of water vapor was similarly determined to define the amounts of water in the saturated soil samples. In such high-organic-content soils the organic vapor sorption and the respective solute sorption from water exhibit linear isotherms over a wide range of relative concentrations. This observation, along with the low BET surface areas of the samples, suggests that partition in the SOM of the samples is the dominant process in the uptake of these liquids. A comparison of the sorption from water solution and from vapor phase shows that water saturation reduces the sorption (partition) efficiency of SOM by ?? 42%; the saturated water content is ??38% by weight of dry SOM. This reduction is relatively small when compared with the almost complete suppression by water of organic compound adsorption on soil minerals. While the effect of water saturation on solute uptake by SOM is much expected in terms of solute partition in SOM, the influence of water on the solubility behavior of polar SOM can be explained only qualitatively by regular solution theory. The results suggest that the major effect of water in a drying-wetting cycle on the organic compound uptake by normal low-organic-content soils (and the associated compound's activity) is the suppression of adsorption by minerals rather than the mitigation of the partition effect in SOM.

  3. Evaluation of the Effect of Two Volatile Organic Compounds on Barley Pathogens.

    PubMed

    Kaddes, Amine; Parisi, Olivier; Berhal, Chadi; Ben Kaab, Sofiene; Fauconnier, Marie-Laure; Nasraoui, Bouzid; Jijakli, M Haissam; Massart, Sébastien; De Clerck, Caroline

    2016-08-26

    This study aimed to determine the effect of Volatile Organic Compounds (VOCs) on some pathogens, these VOCs were emitted during interactions of barley with Fusarium culmorum Schltdl and/or Cochliobolus sativus Shoemaker, two common root rot pathogens. Our work shows that two organic esters: methyl propanoate (MP) and methyl prop-2-enoate (MA) significantly reduced the development of fungi in vitro. Additional tests showed that the esters significantly inhibited spore germination of these pathogens. The activity of these VOCs on a wide range of fungal and bacterial pathogens was also tested in vitro and showed inhibitory action. The effect of the VOCs on infected barley seeds also showed plantlets growing without disease symptoms. MA and MP seem to have potential value as alternative plant protection compounds against barley bioagressors.

  4. Evaluation of the Effect of Two Volatile Organic Compounds on Barley Pathogens.

    PubMed

    Kaddes, Amine; Parisi, Olivier; Berhal, Chadi; Ben Kaab, Sofiene; Fauconnier, Marie-Laure; Nasraoui, Bouzid; Jijakli, M Haissam; Massart, Sébastien; De Clerck, Caroline

    2016-01-01

    This study aimed to determine the effect of Volatile Organic Compounds (VOCs) on some pathogens, these VOCs were emitted during interactions of barley with Fusarium culmorum Schltdl and/or Cochliobolus sativus Shoemaker, two common root rot pathogens. Our work shows that two organic esters: methyl propanoate (MP) and methyl prop-2-enoate (MA) significantly reduced the development of fungi in vitro. Additional tests showed that the esters significantly inhibited spore germination of these pathogens. The activity of these VOCs on a wide range of fungal and bacterial pathogens was also tested in vitro and showed inhibitory action. The effect of the VOCs on infected barley seeds also showed plantlets growing without disease symptoms. MA and MP seem to have potential value as alternative plant protection compounds against barley bioagressors. PMID:27571054

  5. Ice Nucleation by High Molecular Weight Organic Compounds

    NASA Astrophysics Data System (ADS)

    Cantrell, W.

    2003-12-01

    Deep convection in the tropics is frequently associated with biomass burning. Recent work has suggested that the size of ice crystals in the anvils of tropical cumulonimbus clouds may be affected by biomass burning, though the mechanism for such an effect is uncertain (Sherwood, 2002). We will present results of an investigation of the role that high molecular weight organic compounds, known to be produced in biomass burning (Elias et al., 1999), may play in tropical cirrus anvils through heterogeneous nucleation of ice. In particular, we examine the mechanisms underlying heterogeneous nucleation of ice by films of long chain alcohols by studying the interaction of the alcohols and water/ice using temperature controlled, Attenuated Total Reflection - Fourier Transform Infrared spectroscopy. The mechanisms are interpreted in the context of recent criticisms of some aspects of classical nucleation theory (Seeley and Seidler, 2001; Oxtoby, 1998). References V. Elias, B. Simoneit, A. Pereira, J. Cabral, and J. Cardoso, Detection of high molecular weight organic tracers in vegetation smoke samples by high-temperature gas chromatography-mass spectrometry. Environ. Sci. Tecnol., 33, 2369-2376, 1999. D. Oxtoby, Nucleation of first-order phase transitions. Acc. Chem. Res., 31, 91-97, 1998. L. Seeley and G. Seidler, Preactivation in the nucleation of ice by Langmuir films of aliphatic alcohols. J. Chem. Phys., 114, 10464-10470, 2001. S. Sherwood, Aerosols and ice particle size in tropical cumulonimbus. J. Climate, 15, 1051-1063, 2002.

  6. Influence of Sensory Stimulation on Exhaled Volatile Organic Compounds.

    PubMed

    Mazzatenta, A; Pokorski, M; Di Tano, A; Cacchio, M; Di Giulio, C

    2016-01-01

    The real-time exhaled volatile organic compounds (VOCs) have been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. The VOCs profile in exhaled breath reflects the biochemical alterations related to metabolic changes, organ failure, and neuronal activity, which are, at least in part, transmitted via the lungs to the alveolar exhaled breath. Breath analysis has been applied to investigate cancer, lung failure, and neurodegenerative diseases. There are by far no studies on the real-time monitoring of VOCs in sensory stimulation in healthy subjects. Therefore, in this study we investigated the breath parameters and exhaled VOCs in humans during sensory stimulation: smell, hearing, sight, and touch. Responses sensory stimulations were recorded in 12 volunteers using an iAQ-2000 sensor. We found significant effects of sensory stimulation. In particular, olfactory stimulation was the most effective stimulus that elicited the greatest VOCs variations in the exhaled breath. Since the olfactory pathway is distinctly driven by the hypothalamic and limbic circuitry, while other senses project first to the thalamic area and then re-project to other brain areas, the findings suggest the importance of olfaction and chemoreception in the regulation lung gas exchange. VOCs variations during sensory activation may become putative indicators of neural activity. PMID:26453064

  7. Volatile Organic Compounds: Characteristics, distribution and sources in urban schools

    NASA Astrophysics Data System (ADS)

    Mishra, Nitika; Bartsch, Jennifer; Ayoko, Godwin A.; Salthammer, Tunga; Morawska, Lidia

    2015-04-01

    Long term exposure to organic pollutants, both inside and outside school buildings may affect children's health and influence their learning performance. Since children spend significant amount of time in school, air quality, especially in classrooms plays a key role in determining the health risks associated with exposure at schools. Within this context, the present study investigated the ambient concentrations of Volatile Organic Compounds (VOCs) in 25 primary schools in Brisbane with the aim to quantify the indoor and outdoor VOCs concentrations, identify VOCs sources and their contribution, and based on these; propose mitigation measures to reduce VOCs exposure in schools. One of the most important findings is the occurrence of indoor sources, indicated by the I/O ratio >1 in 19 schools. Principal Component Analysis with Varimax rotation was used to identify common sources of VOCs and source contribution was calculated using an Absolute Principal Component Scores technique. The result showed that outdoor 47% of VOCs were contributed by petrol vehicle exhaust but the overall cleaning products had the highest contribution of 41% indoors followed by air fresheners and art and craft activities. These findings point to the need for a range of basic precautions during the selection, use and storage of cleaning products and materials to reduce the risk from these sources.

  8. Influence of Sensory Stimulation on Exhaled Volatile Organic Compounds.

    PubMed

    Mazzatenta, A; Pokorski, M; Di Tano, A; Cacchio, M; Di Giulio, C

    2016-01-01

    The real-time exhaled volatile organic compounds (VOCs) have been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. The VOCs profile in exhaled breath reflects the biochemical alterations related to metabolic changes, organ failure, and neuronal activity, which are, at least in part, transmitted via the lungs to the alveolar exhaled breath. Breath analysis has been applied to investigate cancer, lung failure, and neurodegenerative diseases. There are by far no studies on the real-time monitoring of VOCs in sensory stimulation in healthy subjects. Therefore, in this study we investigated the breath parameters and exhaled VOCs in humans during sensory stimulation: smell, hearing, sight, and touch. Responses sensory stimulations were recorded in 12 volunteers using an iAQ-2000 sensor. We found significant effects of sensory stimulation. In particular, olfactory stimulation was the most effective stimulus that elicited the greatest VOCs variations in the exhaled breath. Since the olfactory pathway is distinctly driven by the hypothalamic and limbic circuitry, while other senses project first to the thalamic area and then re-project to other brain areas, the findings suggest the importance of olfaction and chemoreception in the regulation lung gas exchange. VOCs variations during sensory activation may become putative indicators of neural activity.

  9. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  10. Use of sonication for in-well softening of semivolatile organic compounds. 1997 annual progress report

    SciTech Connect

    Peters, R.W.; Manning, J.; Hoffman, M.R.; Gorelick, S.

    1997-01-01

    'This project investigates the in-situ degradation of semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) using in-well sonication, in-well vapor stripping, and bioremediation. Pretreating groundwaters with sonication techniques in-situ would form VOCs that can be effectively removed by in-well vapor stripping and bioremediation. The mechanistic studies focus on the coupling of megasonics and ultrasonics to soften (i.e., partially degrade) the SVOCs; oxidative reaction mechanism studies; surface corrosion studies (on the reactor walls/well); enhancement due to addition of oxidants, quantification of the hydroxyl radical formation; identification/quantification of degradation products; volatility/degradability of the treated waters; development of a computer simulation model to describe combined in-well sonication/in-well vapor stripping/bioremediation; systems analysis/economic analysis; large laboratory-scale experiment verification; and field demonstration of the integrated technology. Benefits of this approach include: (1) Remediation is performed in-situ; (2) The treatment systems complement each other; their combination can drastically reduce or remove SVOCs and VOCs; (3) Ability to convert hard-to-degrade organics into more volatile organic compounds; (4) Ability to remove residual VOCs and softened SVOCs through the combined action of in-well vapor stripping and biodegradation; (5) Does not require handling or disposing of water at the ground surface; and (6) Cost-effective and improved efficiency, resulting in shortened clean-up times to remediate a site.'

  11. Perfluorinated compounds in aquatic organisms at various trophic levels in a Great Lakes food chain.

    PubMed

    Kannan, Kurunthachalam; Tao, Lin; Sinclair, Ewan; Pastva, Stephanie D; Jude, Dave J; Giesy, John P

    2005-05-01

    Trophic transfer of perfluorooctanesulfonate (PFOS) and other related perfluorinated compounds was examined in a Great Lakes benthic foodweb including water-algae-zebra mussel-round goby-smallmouth bass. In addition, perfluorinated compounds were measured in livers and eggs of Chinook salmon and lake whitefish, in muscle tissue of carp, and in eggs of brown trout collected from Michigan. Similarly, green frog livers, snapping turtle plasma, mink livers, and bald eagle tissues were analyzed to determine concentrations in higher trophic-level organisms in the food chain. PFOS was the most widely detected compound in benthic organisms at various trophic levels. Concentrations of PFOS in benthic invertebrates such as amphipods and zebra mussels were approximately 1000-fold greater than those in surrounding water, which suggested a bioconcentration factor (BCF; concentration in biota/concentration in water) of 1000 in benthic invertebrates. Concentrations of PFOS in round gobies were two- to fourfold greater than those in their prey organisms such as zebra mussels and amphipods. Concentrations of PFOS in predatory fishes (Chinook salmon and lake whitefish) were 10 to 20-fold greater than those in their prey species. Concentrations of PFOS in mink and bald eagles were, on average, 5- to 10-fold greater than those in Chinook salmon, carp, or snapping turtles. Because of the accumulation of PFOS in liver and blood, the biomagnification factor (BMF) of perfluorinated compounds in higher trophic-level organisms such as salmonid fishes, mink, and eagles were based on the concentrations in livers or plasma. Overall, these results suggest a BCF of PFOS of approximately 1000 (whole-body based) in benthic invertebrates, and a BMF of 10 to 20 in mink or bald eagles, relative to their prey items. Eggs of fish contained notable concentrations of PFOS, suggesting oviparous transfer of this compound. PFOA was found in water, but its biomagnification potential was lower than that of

  12. Reaction of ozone with c5 and c6 biogenic volatile organic compounds

    NASA Astrophysics Data System (ADS)

    O Connor, M.; O Dwyer, M.; Wenger, J.

    2003-04-01

    REACTION OF OZONE WITH C5 AND C6 BIOGENIC VOLATILE ORGANIC COMPOUNDS M. O'Connor, M. O'Dwyer, J. Wenger CRAC-Centre for Research into Atmospheric Chemistry, Department of Chemistry, University College Cork, Ireland. jwenger@chemistry.ucc.ie Biogenic volatile organic compounds (BVOCs) account for around 90% of hydrocarbon emissionsinto the Earth's atmosphere. During the last ten years an increasing number of oxygenated BVOCs have also been detected in field measurement campaigns and plant emission studies. In particular a range of C5 and C6 oxygenates have been identifiedincluding compounds such as 1-penten-3-ol, E-2-hexenal and E-2-hexenyl acetate. The atmospheric impact of many of these compounds is largely unknown. The major atmospheric degradation processes for biogenic VOCs are gas-phase reaction with hydroxyl (OH) radicals, nitrate (NO3) radicals and ozone (O3). These reactions produce oxidized hydrocarbons, ozone and secondary organic aerosol and, as a result, exert a strong influence on the chemical compositionof the atmosphere. Although a number of studies have been made on the kinetics of the degradation of BVOCs, very few details are available concerning the reaction products and chemical mechanisms. In this work we have studied the reaction of O3 with a series of C5 unsaturated alcohols and C6 unsaturated aldehydes. Rate coefficients for these reactions have been studied using the relative rate method and gas-phase oxidation products have been identified using FTIR spectroscopy and PFBHA derivatisation coupled with GC-MS analysis. In addition secondary organic aerosol (SOA) formation has been studied as a function of humidity. The data obtained in this work will be used to further our knowledge of the atmospheric degradation of these naturally occurring compounds.

  13. Sulfate minerals: a problem for the detection of organic compounds on Mars?

    PubMed

    Lewis, James M T; Watson, Jonathan S; Najorka, Jens; Luong, Duy; Sephton, Mark A

    2015-03-01

    The search for in situ organic matter on Mars involves encounters with minerals and requires an understanding of their influence on lander and rover experiments. Inorganic host materials can be helpful by aiding the preservation of organic compounds or unhelpful by causing the destruction of organic matter during thermal extraction steps. Perchlorates are recognized as confounding minerals for thermal degradation studies. On heating, perchlorates can decompose to produce oxygen, which then oxidizes organic matter. Other common minerals on Mars, such as sulfates, may also produce oxygen upon thermal decay, presenting an additional complication. Different sulfate species decompose within a large range of temperatures. We performed a series of experiments on a sample containing the ferric sulfate jarosite. The sulfate ions within jarosite break down from 500 °C. Carbon dioxide detected during heating of the sample was attributed to oxidation of organic matter. A laboratory standard of ferric sulfate hydrate released sulfur dioxide from 550 °C, and an oxygen peak was detected in the products. Calcium sulfate did not decompose below 1000 °C. Oxygen released from sulfate minerals may have already affected organic compound detection during in situ thermal experiments on Mars missions. A combination of preliminary mineralogical analyses and suitably selected pyrolysis temperatures may increase future success in the search for past or present life on Mars.

  14. Sulfate minerals: a problem for the detection of organic compounds on Mars?

    PubMed

    Lewis, James M T; Watson, Jonathan S; Najorka, Jens; Luong, Duy; Sephton, Mark A

    2015-03-01

    The search for in situ organic matter on Mars involves encounters with minerals and requires an understanding of their influence on lander and rover experiments. Inorganic host materials can be helpful by aiding the preservation of organic compounds or unhelpful by causing the destruction of organic matter during thermal extraction steps. Perchlorates are recognized as confounding minerals for thermal degradation studies. On heating, perchlorates can decompose to produce oxygen, which then oxidizes organic matter. Other common minerals on Mars, such as sulfates, may also produce oxygen upon thermal decay, presenting an additional complication. Different sulfate species decompose within a large range of temperatures. We performed a series of experiments on a sample containing the ferric sulfate jarosite. The sulfate ions within jarosite break down from 500 °C. Carbon dioxide detected during heating of the sample was attributed to oxidation of organic matter. A laboratory standard of ferric sulfate hydrate released sulfur dioxide from 550 °C, and an oxygen peak was detected in the products. Calcium sulfate did not decompose below 1000 °C. Oxygen released from sulfate minerals may have already affected organic compound detection during in situ thermal experiments on Mars missions. A combination of preliminary mineralogical analyses and suitably selected pyrolysis temperatures may increase future success in the search for past or present life on Mars. PMID:25695727

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Toward engineering functional organ modules by additive manufacturing.

    PubMed

    Marga, Francoise; Jakab, Karoly; Khatiwala, Chirag; Shepherd, Benjamin; Dorfman, Scott; Hubbard, Bradley; Colbert, Stephen; Gabor, Forgacs

    2012-06-01

    Tissue engineering is emerging as a possible alternative to methods aimed at alleviating the growing demand for replacement tissues and organs. A major pillar of most tissue engineering approaches is the scaffold, a biocompatible network of synthetic or natural polymers, which serves as an extracellular matrix mimic for cells. When the scaffold is seeded with cells it is supposed to provide the appropriate biomechanical and biochemical conditions for cell proliferation and eventual tissue formation. Numerous approaches have been used to fabricate scaffolds with ever-growing complexity. Recently, novel approaches have been pursued that do not rely on artificial scaffolds. The most promising ones utilize matrices of decellularized organs or methods based on multicellular self-assembly, such as sheet-based and bioprinting-based technologies. We briefly overview some of the scaffold-free approaches and detail one that employs biological self-assembly and bioprinting. We describe the technology and its specific applications to engineer vascular and nerve grafts.

  17. Fatty acids and small organic compounds bind to mineralo-organic nanoparticles derived from human body fluids as revealed by metabolomic analysis.

    PubMed

    Martel, Jan; Wu, Cheng-Yeu; Hung, Cheng-Yu; Wong, Tsui-Yin; Cheng, Ann-Joy; Cheng, Mei-Ling; Shiao, Ming-Shi; Young, John D

    2016-03-14

    Nanoparticles entering the human body instantly become coated with a "protein corona" that influences the effects and distribution of the particles in vivo. Yet, whether nanoparticles may bind to other organic compounds remains unclear. Here we use an untargeted metabolomic approach based on ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry to identify the organic compounds that bind to mineral nanoparticles formed in human body fluids (serum, plasma, saliva, and urine). A wide range of organic compounds is identified, including fatty acids, glycerophospholipids, amino acids, sugars, and amides. Our results reveal that, in addition to the proteins identified previously, nanoparticles harbor an "organic corona" containing several fatty acids which may affect particle-cell interactions in vivo. This study provides a platform to study the organic corona of biological and synthetic nanoparticles found in the human body.

  18. 40 CFR Appendix Viii to Part 266 - Organic Compounds for Which Residues Must Be Analyzed

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Organic Compounds for Which Residues...—Organic Compounds for Which Residues Must Be Analyzed Volatiles Semivolatiles Benzene Bis(2-ethylhexyl... those compounds that do not have an established F039 nonwastewater concentration limit....

  19. Determination of regulatory organic compounds in radioactive waste samples. Semivolatile organics in aqueous liquids

    SciTech Connect

    Tomkins, B.A.; Caton, J.E. Jr.; Fleming, G.S.; Garcia, M.E.; Harmon, S.H.; Schenley, R.L.; Treese, C.A.; Griest, W.H. )

    1990-02-01

    The regulatory semivolatile organic compounds present in radioactive aqueous waste samples are extracted and concentrated in a small-scale version of a standard EPA procedure normally used for ground waters. Decontamination is sufficient to permit analysis of the extract in a conventional gas chromatography/mass spectrometry laboratory. The performance of the modified procedure, based on surrogate standards, matrix spikes and matrix spike duplicates, and blanks, is comparable to that of the standard method. The modified procedure was applied to a variety of aqueous radioactive waste tank samples. Only 12 of the EPA Appendix VIII compounds were present, and none in concentrations exceeding the reporting limit (500 or 2,500 {mu}g/L). The most common semivolatile present was tributyl phosphate, an organic extractant commonly used in radiochemical processing, at 2,000-30,000 {mu}g/L.

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

    PubMed Central

    Khalid, Tanzeela; Aggio, Raphael; White, Paul; De Lacy Costello, Ben; Persad, Raj; Al-Kateb, Huda; Jones, Peter; Probert, Chris S.; Ratcliffe, Norman

    2015-01-01

    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. PMID:26599280

  1. Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils

    PubMed Central

    Jagadamma, Sindhu; Mayes, Melanie A.; Phillips, Jana R.

    2012-01-01

    Background Physico-chemical sorption onto soil minerals is one of the major processes of dissolved organic carbon (OC) stabilization in deeper soils. The interaction of DOC on soil solids is related to the reactivity of soil minerals, the chemistry of sorbate functional groups, and the stability of sorbate to microbial degradation. This study was conducted to examine the sorption of diverse OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols). Methodology Equilibrium batch experiments were conducted using 0–100 mg C L−1 at a solid-solution ratio of 1∶60 for 48 hrs on natural soils and on soils sterilized by γ-irradiation. The maximum sorption capacity, Qmax and binding coefficient, k were calculated by fitting to the Langmuir model. Results Ultisols appeared to sorb more glucose, alanine, and salicylic acid than did Alfisols or Mollisols and the isotherms followed a non-linear pattern (higher k). Sterile experiments revealed that glucose and alanine were both readily degraded and/or incorporated into microbial biomass because the observed Qmax under sterile conditions decreased by 22–46% for glucose and 17–77% for alanine as compared to non-sterile conditions. Mollisols, in contrast, more readily reacted with oxalic acid (Qmax of 886 mg kg−1) and sinapyl alcohol (Qmax of 2031 mg kg−1), and no degradation was observed. The reactivity of Alfisols to DOC was intermediate to that of Ultisols and Mollisols, and degradation followed similar patterns as for Ultisols. Conclusion This study demonstrated that three common temperate soil orders experienced differential sorption and degradation of simple OC compounds, indicating that sorbate chemistry plays a significant role in the sorptive stabilization of DOC. PMID:23209742

  2. Spatial Arrangement of Organic Compounds on a Model Mineral Surface: Implications for Soil Organic Matter Stabilization

    NASA Astrophysics Data System (ADS)

    Ambaye, Haile; Petridis, Loukas; Jagadamma, Sindhu; Kilbey, Michael; Lauter, Valeria; Lokitz, Bradley; Mayes, Melanie

    2015-03-01

    Stability of organic carbon compounds in soil is important for global climate futures which could be affected by the complexity of the mineral-organic carbon interfaces. We examined the nanoscale structure of model interfaces by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose, deuterated-amphiphilic stearic acid (SA) and Natural Organic Matters (NOM) onto a soil mineral analogue (Al2O3) . The NOM was separated into its constituent components such as NOM-Philic and NOM-Phobic when it is deposited onto the soil mineral. We used Neutron Reflectivity technique to understand the depth organization of the thin films. The result indicates that glucose molecules reside in a layer between Al2O3 and stearic acid and SA self-assembles. No self-assembly of SA was observed when SA and NOM-Phobic was deposited on the mineral soil. Molecular dynamics simulations reveal the thermodynamic driving force behind glucose partitioning on the mineral interface. Funded by ORNL Director's Research and Development Program. Research at ORNL was sponsored by the BES, DOE.

  3. Aqueous processing of organic compounds in carbonaceous asteroids

    NASA Astrophysics Data System (ADS)

    Trigo-Rodríguez, Josep Maria; Rimola, Albert; Martins, Zita

    2015-04-01

    There is growing evidence pointing towards a prebiotic synthesis of complex organic species in water-rich undifferentiated bodies. For instance, clays have been found to be associated with complex organic compounds (Pearson et al. 2002; Garvie & Buseck 2007; Arteaga et al. 2010), whereas theoretical calculations have studied the interaction between the organic species and surface minerals (Rimola et al., 2013) as well as surface-induced reactions (Rimola at al. 2007). Now, we are using more detailed analytical techniques to study the possible processing of organic molecules associated with the mild aqueous alteration in CR, CM and CI chondrites. To learn more about these processes we are studying carbonaceous chondrites at Ultra High-Resolution Transmission Electron Microscopy (UHR-TEM). We are particularly interested in the relationship between organics and clay minerals in carbonaceous chondrites (CCs) matrixes (Trigo-Rodríguez et al. 2014, 2015).We want to address two goals: i) identifying the chemical steps in which the organic molecules could have increased their complexity (i.e., surface interaction and catalysis); and ii) studying if the organic matter present in CCs experienced significant processing concomitant to the formation of clays and other minerals at the time in which these planetary bodies experienced aqueous alteration. Here, these two points are preliminarily explored combing experimental results with theoretical calculations based on accurate quantum mechanical methods. References Arteaga O, Canillas A, Crusats J, El-Hachemi Z, Jellison GE, Llorca J, Ribó JM (2010) Chiral biases in solids by effect of shear gradients: a speculation on the deterministic origin of biological homochirality. Orig Life Evol Biosph 40:27-40. Garvie LAJ, Buseck PR (2007) Prebiotic carbon in clays from Orgueil and Ivuna (CI) and Tagish lake (C2 ungrouped) meteorites. Meteorit Planet Sci 42:2111-2117. Pearson VK, Sephton MA, Kearsley AT, Bland AP, Franchi IA, Gilmour

  4. Fatty acids and small organic compounds bind to mineralo-organic nanoparticles derived from human body fluids as revealed by metabolomic analysis

    NASA Astrophysics Data System (ADS)

    Martel, Jan; Wu, Cheng-Yeu; Hung, Cheng-Yu; Wong, Tsui-Yin; Cheng, Ann-Joy; Cheng, Mei-Ling; Shiao, Ming-Shi; Young, John D.

    2016-03-01

    Nanoparticles entering the human body instantly become coated with a ``protein corona'' that influences the effects and distribution of the particles in vivo. Yet, whether nanoparticles may bind to other organic compounds remains unclear. Here we use an untargeted metabolomic approach based on ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry to identify the organic compounds that bind to mineral nanoparticles formed in human body fluids (serum, plasma, saliva, and urine). A wide range of organic compounds is identified, including fatty acids, glycerophospholipids, amino acids, sugars, and amides. Our results reveal that, in addition to the proteins identified previously, nanoparticles harbor an ``organic corona'' containing several fatty acids which may affect particle-cell interactions in vivo. This study provides a platform to study the organic corona of biological and synthetic nanoparticles found in the human body.Nanoparticles entering the human body instantly become coated with a ``protein corona'' that influences the effects and distribution of the particles in vivo. Yet, whether nanoparticles may bind to other organic compounds remains unclear. Here we use an untargeted metabolomic approach based on ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry to identify the organic compounds that bind to mineral nanoparticles formed in human body fluids (serum, plasma, saliva, and urine). A wide range of organic compounds is identified, including fatty acids, glycerophospholipids, amino acids, sugars, and amides. Our results reveal that, in addition to the proteins identified previously, nanoparticles harbor an ``organic corona'' containing several fatty acids which may affect particle-cell interactions in vivo. This study provides a platform to study the organic corona of biological and synthetic nanoparticles found in the human body. Electronic supplementary information (ESI) available. See

  5. Addition of Phenols Compounds to Meat Dough Intended for Salami Manufacture and its Antioxidant Effect

    PubMed Central

    Fasolato, Luca; Cardazzo, Barbara; Carraro, Lisa; Taticchi, Agnese; Balzan, Stefania

    2014-01-01

    A purified extract of phenols compounds (65% of phenolic content of which decarboxymethyl oleuropein aglycone represented 45% of the wet mass) obtained from vegetation water (a by-product of oil mill) was added to a ground meat dough intended for salami manufacture in two concentration levels: 75 and 150 mg/100 g of dough (F1 and F2, respectively). The control batch was composed of lean and fat cuts of pork in 70:30 ratio, 2.7% salt and a mixed starter culture of staphylococci and pediococci. After stuffing into natural casings, salamis were aged until they reached a total weight loss of 30%. The product was then sliced and packaged in a protective atmosphere (nitrogen:carbon dioxide 80:20) and placed in a refrigerator thermostat (2-4°C) with alternating 12 h of artificial light and darkness. The samples were analysed for the measurement of pH, water activity, organic acidity, peroxide number and secondary products of lipid peroxidation at the time of slicing and after 10, 20 and 30 days of storage into the refrigerated thermostat. The pH and water activity were not substantially different between the control and the two enriched batches. The peroxide number and secondary products of lipid peroxidation values in the two batches with phenols were at least substantially lower than the control sample. In conclusion, the phenol compounds obtained from vegetation water have shown no interference with the ripening process while protecting the dough from oxidation. PMID:27800353

  6. Compositing water samples for analysis of volatile organic compounds

    USGS Publications Warehouse

    Lopes, T.J.; Fallon, J.D.; Maluk, T.L.

    2000-01-01

    Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Researchers are able to derive

  7. Reducing Emissions of Volatile Organic Compounds - Final Report - 08/15/1997 - 02/14/2001

    SciTech Connect

    Stensel, H. David; Strand, Stuart E.

    2001-03-14

    The overall objective of this research was to determine if the shallow suspended growth reactor (SSGR) could provide sufficient treatment performance of organic and reduced sulfur (TRS) compounds, at 50 C to meet the EPA ''cluster rule'' regulatory limits. The biodegradation of a mixture of organic compounds that could be present in pulp and paper high volume low concentration gas streams was evaluated at 50 C in a bench-scale SSGR. The removal of methanol was followed in particular, and was mathematically modeled to evaluate the effect of process design and operating parameters on methanol removal. Additional tests were performed to obtain mass transfer and biodegradation kinetic parameters for the model. The acclimation of microbial populations capable of degrading TRS compounds from various seed sources was studied in batch reactors at 30 and 50 C. The degradation of TRS compounds in bench-scale SSGR was studied at 20-50 C. Also, the biodegradation kinetic and mass transfer coefficients for alpha-terpinene and gamma-terpinene were studied. Finally, a pilot plant was constructed and operated at Simpson pulp and paper mill in Tacoma, WA.

  8. Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste.

    PubMed

    Nour, Violeta; Ionica, Mira Elena; Trandafir, Ion

    2015-12-01

    The tomato processing industry generates high amounts of waste, mainly tomato skins and seeds, which create environmental problems. These residues are attractive sources of valuable bioactive components and pigments. A relatively simple recovery technology could consist of production of powders to be directly incorporated into foods. Tomato waste coming from a Romanian tomato processing unit were analyzed for the content of several bioactive compounds like ascorbic acid, β-carotene, lycopene, total phenolics, mineral and trace elements. In addition, its antioxidant capacity was assayed. Results revealed that tomato waste (skins and seeds) could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods. Dry tomato processing waste were used to supplement wheat flour at 6 and 10 % levels (w/w flour basis) and the effects on the bread's physicochemical, baking and sensorial characteristics were studied. The following changes were observed: increase in moisture content, titratable acidity and bread crumb elasticity, reduction in specific volume and bread crumb porosity. The addition of dry tomato waste at 6 % resulted in bread with good sensory characteristics and overall acceptability but as the amount of dry tomato waste increased to 10 %, bread was less acceptable.

  9. Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste.

    PubMed

    Nour, Violeta; Ionica, Mira Elena; Trandafir, Ion

    2015-12-01

    The tomato processing industry generates high amounts of waste, mainly tomato skins and seeds, which create environmental problems. These residues are attractive sources of valuable bioactive components and pigments. A relatively simple recovery technology could consist of production of powders to be directly incorporated into foods. Tomato waste coming from a Romanian tomato processing unit were analyzed for the content of several bioactive compounds like ascorbic acid, β-carotene, lycopene, total phenolics, mineral and trace elements. In addition, its antioxidant capacity was assayed. Results revealed that tomato waste (skins and seeds) could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods. Dry tomato processing waste were used to supplement wheat flour at 6 and 10 % levels (w/w flour basis) and the effects on the bread's physicochemical, baking and sensorial characteristics were studied. The following changes were observed: increase in moisture content, titratable acidity and bread crumb elasticity, reduction in specific volume and bread crumb porosity. The addition of dry tomato waste at 6 % resulted in bread with good sensory characteristics and overall acceptability but as the amount of dry tomato waste increased to 10 %, bread was less acceptable. PMID:26604402

  10. Understanding the Oxidative Addition of σ-Bonds to Group 13 Compounds.

    PubMed

    García-Rodeja, Yago; Bickelhaupt, F Matthias; Fernández, Israel

    2016-09-12

    The oxidative addition reaction of X-H σ-bonds to Group 13 (E=Al, Ga, In) containing compounds has been computationally explored within the density functional theory framework. These reactions, which proceed concertedly involving the E(I) →E(III) oxidation, are exothermic and associated with relatively low activation barriers. In addition, the following trends in reactivity are found: (i) the activation barriers are lower for the X-H bonds involving the heavier element in the same group (ΔE(≠) : C>Si; N>P; O>S), (ii) the process becomes kinetically more favorable in going from left to right in the same period (ΔE(≠) : C>N>O; Si≈P>S), and (iii) the activation barrier systematically increases when heavier Group 13 elements are involved in the transformation (ΔE(≠) : Al

  11. Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

    NASA Astrophysics Data System (ADS)

    Ho, K. F.; Lee, S. C.; Chiu, Gloria M. Y.

    Volatile organic compounds (VOCs), PAHs and carbonyl compounds are the major toxic components in Hong Kong. Emissions from motor vehicles have been one of the primary pollution sources in the metropolitan areas throughout Hong Kong for a long time. A 1-yr monitoring program for VOCs, PAHs and carbonyl compounds had been performed at a roadside urban station at Hong Kong Polytechnic University in order to determine the variations and correlations of each selected species (VOCs, PAHs and carbonyl compounds). This study is aimed to analyze toxic volatile organic compounds (benzene, toluene, ethylbenzene and xylene), two carbonyl compounds (formaldehyde, acetaldehyde), and selective polycyclic aromatic hydrocarbons. The monitoring program started from 16 April 1999 to 30 March 2000. Ambient VOC concentrations, many of which originate from the same sources as particulate PAHs and carbonyls compounds, show significant quantities of benzene, toluene and xylenes. Correlations and multivariate analysis of selected gaseous and particulate phase organic pollutants were performed. Source identification by principle component analysis and hierarchical cluster analysis allowed the identification of four sources (factors) for the roadside monitoring station. Factor 1 represents the effect of diesel vehicle exhaust. Factor 2 shows the contribution of aromatic compounds. Factor 3 explains photochemical products—formaldehyde and acetaldehyde. Factor 4 explains the effect of gasoline vehicle exhaust.

  12. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K; Hupp, Joseph T

    2013-06-25

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  13. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.

    2012-09-11

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  14. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds

    PubMed Central

    Sackett, Tara E.; Thomas, Sean C.

    2016-01-01

    Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)–gas chromatography–mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant

  15. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds.

    PubMed

    Gale, Nigel V; Sackett, Tara E; Thomas, Sean C

    2016-01-01

    Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)-gas chromatography-mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant

  16. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds

    PubMed Central

    Sackett, Tara E.; Thomas, Sean C.

    2016-01-01

    Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)–gas chromatography–mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant

  17. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds.

    PubMed

    Gale, Nigel V; Sackett, Tara E; Thomas, Sean C

    2016-01-01

    Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)-gas chromatography-mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant

  18. Fate of trace organic compounds during vadose zone soil treatment in an onsite wastewater system

    USGS Publications Warehouse

    Conn, K.E.; Siegrist, R.L.; Barber, L.B.; Meyer, M.T.

    2010-01-01

    During onsite wastewater treatment, trace organic compounds are often present in the effluents applied to subsurface soils for advanced treatment during vadose zone percolation and groundwater recharge. The fate of the endocrine-disrupting surfactant metabolites 4-nonylphenol (NP), 4-nonylphenolmonoethoxylate (NP1EO), and 4-nonylphenolmonoethoxycarboxylate (NP1EC), metal-chelating agents ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), antimicrobial agent triclosan, stimulant caffeine, and antibiotic sulfamethoxazole during transport through an unsaturated sandy loam soil was studied at a field-scale test site. To assess the effects of effluent quality and hydraulic loading rate (HLR) on compound fate in the soil profile, two effluents (septic tank or textile biofilter) were applied at two design HLRs (2 or 8 cm/d). Chemical concentrations were determined in the two effluents and soil pore water at 60, 120, and 240 cm below the soil infiltrative surface. Concentrations of trace organic compounds in septic tank effluent were reduced by more than 90% during transport through 240 cm (often within 60 cm) of soil, likely due to sorption and biotransformation. However, the concentration of NP increased with depth in the shallow soil profile. Additional treatment of anaerobic septic tank effluent with an aerobic textile biofilter reduced effluent concentrations of many compounds, but generally did not affect any changes in pore water concentrations. The soil profile receiving septic tank effluent (vs. textile biofilter effluent) generally had greater percent removal efficiencies. EDTA, NP, NP1EC, and sulfamethoxazole were measured in soil pore water, indicating the ability of some trace organic compounds to reach shallow groundwater. Risk is highly dependent on the degree of further treatment in the saturated zone and the types and proximity of uses for the receiving groundwater environment. ?? 2009 SETAC.

  19. Factors controlling volatile organic compounds in dwellings in Melbourne, Australia.

    PubMed

    Cheng, M; Galbally, I E; Molloy, S B; Selleck, P W; Keywood, M D; Lawson, S J; Powell, J C; Gillett, R W; Dunne, E

    2016-04-01

    This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n-butane, 2-methylbutane, toluene, formaldehyde, acetaldehyde, d-limonene, ethanol, 2-propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum-like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings.

  20. Volatile organic compounds in the atmosphere of Mexico City

    NASA Astrophysics Data System (ADS)

    Garzón, Jessica P.; Huertas, José I.; Magaña, Miguel; Huertas, María E.; Cárdenas, Beatriz; Watanabe, Takuro; Maeda, Tsuneaki; Wakamatsu, Shinji; Blanco, Salvador

    2015-10-01

    The Mexico City Metropolitan Area (MCMA) is one of the most polluted megacities in North America. Therefore, it is an excellent benchmark city to understand atmospheric chemistry and to implement pilot countermeasures. Air quality in the MCMA is not within acceptable levels, mainly due to high ground levels of ozone (O3). Tropospheric O3 is a secondary pollutant formed from the oxidation of volatile organic compounds (VOCs) in the presence of nitrogen oxides and sunlight. To gain a better understanding of O3 formation in megacities, evaluate the effectiveness of already-implemented countermeasures, and identify new cost-effective alternatives to reduce tropospheric O3 concentrations, researchers and environmental authorities require updated concentrations for a broader range of VOCs. Moreover, in an effort to protect human health and the environment, it is important to understand which VOCs exceed reference safe values or most contribute to O3 formation, as well as to identify the most probable emission sources of those VOCs. In this work, 64 VOCs, including 36 toxic VOCs, were measured at four sites in the MCMA during 2011-2012. VOCs related to liquefied petroleum gas leakages exhibited the highest concentrations. Toxic VOCs with the highest average concentrations were acetone and ethanol. The toxic VOC benzene represented the highest risk to Mexican citizens, and toluene contributed the most to O3 formation. Correlation analysis indicated that the measured VOCs come from vehicular emissions and solvent-related industrial sources.

  1. Sources of volatile organic compounds in Cairo's ambient air.

    PubMed

    Abu-Allaban, M; Lowenthal, D H; Gertler, A W; Labib, M

    2009-10-01

    The greater Cairo area suffers from extreme levels of gas and particulate phase air pollutants. In order to reduce the levels of ambient pollution, the USAID and the Egyptian Environmental Affairs Agency (EEAA) have supported the Cairo Air Improvement Project (CAIP). As part of this project, two intensive ambient monitoring studies were carried out during the period of February 22 to March 4 and October 27 to November 27, 1999. Volatile organic compounds (VOCs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. During the February/March study, samples were collected daily, while in the October/November study samples were collected every other day. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. High levels of NMHC were observed at all locations. NMHC concentrations ranged from 365 ppb C at Helwan to 1,848 ppb C at El Qualaly during winter, 1999 and from 461 ppb C at Kaha to 2,037 ppb C at El Qualaly during fall, 1999. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The highest mobile source contributions were estimated at this site. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and compressed natural gas. PMID:18843549

  2. Real time analysis of volatile organic compounds (VOCs) in centenarians.

    PubMed

    Mazzatenta, Andrea; Pokorski, Mieczyslaw; Di Giulio, Camillo

    2015-04-01

    Centenarians are a model to study human longevity and the physiological process of aging. A plethora of studies on this model show the complexity of the system. Laboratory studies fail to find a biomarker of senescence. The real time exhaled breath volatile organic compounds (VOCs) has been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. VOCs exhaled by centenarians have not been studied in the general population and across-age-groups. In the present study we investigated, in real time, the breath properties and VOC exhaled content in healthy centenarians as compared with non-centenarian seniors and young healthy subjects. We found distinctly different breath pattern and distribution profiles of VOCs in the centenarians. Thus, the VOCs measurement allowed to discriminate the differences between the age-groups. We propose a VOCs fingerprint as a biomarker underlying the physiological mechanisms of aging and longevity. Longevity should be considered physiologically as a new phase of life, characteristic of the well adapted subject.

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

    PubMed

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

    2011-01-01

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

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

    PubMed

    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. PMID:19029718

  5. Prediction of boiling points of organic compounds by QSPR tools.

    PubMed

    Dai, Yi-min; Zhu, Zhi-ping; Cao, Zhong; Zhang, Yue-fei; Zeng, Ju-lan; Li, Xun

    2013-07-01

    The novel electro-negativity topological descriptors of YC, WC were derived from molecular structure by equilibrium electro-negativity of atom and relative bond length of molecule. The quantitative structure-property relationships (QSPR) between descriptors of YC, WC as well as path number parameter P3 and the normal boiling points of 80 alkanes, 65 unsaturated hydrocarbons and 70 alcohols were obtained separately. The high-quality prediction models were evidenced by coefficient of determination (R(2)), the standard error (S), average absolute errors (AAE) and predictive parameters (Qext(2),RCV(2),Rm(2)). According to the regression equations, the influences of the length of carbon backbone, the size, the degree of branching of a molecule and the role of functional groups on the normal boiling point were analyzed. Comparison results with reference models demonstrated that novel topological descriptors based on the equilibrium electro-negativity of atom and the relative bond length were useful molecular descriptors for predicting the normal boiling points of organic compounds.

  6. Prediction of boiling points of organic compounds by QSPR tools.

    PubMed

    Dai, Yi-min; Zhu, Zhi-ping; Cao, Zhong; Zhang, Yue-fei; Zeng, Ju-lan; Li, Xun

    2013-07-01

    The novel electro-negativity topological descriptors of YC, WC were derived from molecular structure by equilibrium electro-negativity of atom and relative bond length of molecule. The quantitative structure-property relationships (QSPR) between descriptors of YC, WC as well as path number parameter P3 and the normal boiling points of 80 alkanes, 65 unsaturated hydrocarbons and 70 alcohols were obtained separately. The high-quality prediction models were evidenced by coefficient of determination (R(2)), the standard error (S), average absolute errors (AAE) and predictive parameters (Qext(2),RCV(2),Rm(2)). According to the regression equations, the influences of the length of carbon backbone, the size, the degree of branching of a molecule and the role of functional groups on the normal boiling point were analyzed. Comparison results with reference models demonstrated that novel topological descriptors based on the equilibrium electro-negativity of atom and the relative bond length were useful molecular descriptors for predicting the normal boiling points of organic compounds. PMID:23792208

  7. Personal exposure to volatile organic compounds in the Czech Republic.

    PubMed

    Svecova, Vlasta; Topinka, Jan; Solansky, Ivo; Sram, Radim J

    2012-09-01

    Personal exposures to volatile organic compounds (VOCs) were measured in the three industrial cities in the Czech Republic, Ostrava, Karvina and Havirov, while the city of Prague served as a control in a large-scale molecular epidemiological study identifying the impacts of air pollution on human health. Office workers from Ostrava and city policemen from Karvina, Havirov and Prague were monitored in the winter and summer of 2009. Only adult non-smokers participated in the study (N=160). Radiello-diffusive passive samplers were used to measure the exposure to benzene, toluene, ethylbenzene, meta- plus para-xylene and ortho-xylene (BTEX). All participants completed a personal questionnaire and a time-location-activity diary (TLAD). The average personal BTEX exposure levels in both seasons were 7.2/34.3/4.4/16.1 μg/m(3), respectively. The benzene levels were highest in winter in Karvina, Ostrava and Prague: 8.5, 7.2 and 5.3 μg/m(3), respectively. The personal exposures to BTEX were higher than the corresponding stationary monitoring levels detected in the individual localities (P<0.001; except m,p-xylene in summer). The indoor environment, ETS (environmental tobacco smoke), cooking, a home-heating fireplace or gas stove, automobile use and being in a restaurant were important predictors for benzene personal exposure. Ostrava's outdoor benzene pollution was a significant factor increasing the exposure of the Ostrava study participants in winter (P<0.05).

  8. Elimination of volatile organic compounds by biofiltration: a review.

    PubMed

    Nikiema, Josiane; Dastous, Paul-André; Heitz, Michèle

    2007-01-01

    Volatile organic compounds (VOCs) are pollutants that are responsible for the formation of the tropospheric ozone, one of the precursors of smog. VOCs are emitted by various industries including chemical plants, pulp and paper mills, pharmaceuticals, cosmetics, electronics and agri-food industries. Some VOCs cause odor pollution while many of them are harmful to environment and human or animal health. For the removal of VOCs, biofiltration, a biological process, has proved to be reliable when properly operated. This process has therefore been widely applied in Europe and North America. The main advantages associated with the use of biofiltration are related to its set-up, maintenance, and operating costs which are usually lower than those related to other VOCs control technologies and because it is less harmful for the environment than conventional processes like incineration. In the present paper, the main parameters (type, moisture, pH, and temperature of filter bed, microbial population, nutrients concentrations, and VOCs' inlet load) to be controlled during the biofiltration are identified and described in detail. The main phenomena involved in biofiltration are also discussed. For improving the efficiency of VOC control biotechnology, new techniques are now proposed that include the use of membranes, biphasic reactors, UV photolysis, and many others.

  9. Predicting the emission rate of volatile organic compounds fromvinyl flooring

    SciTech Connect

    Cox, Steven S.; Little, John C.; Hodgson, Alfred T.

    2001-03-01

    A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion-controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C{sub 0}), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests, and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top side up and bottom side up. With the exception of phenol, and within the limits of experimental precision, the mass of VOCs recovered in the gas phase balances the mass emitted from the material phase. The model parameters (C{sub 0}, K, and D) were measured using procedures that were completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.

  10. Identification of priority organic compounds in groundwater recharge of China.

    PubMed

    Li, Zhen; Li, Miao; Liu, Xiang; Ma, Yeping; Wu, Miaomiao

    2014-09-15

    Groundwater recharge using reclaimed water is considered a promising method to alleviate groundwater depletion, especially in arid areas. Traditional water treatment systems are inefficient to remove all the types of contaminants that would pose risks to groundwater, so it is crucial to establish a priority list of organic compounds (OCs) that deserve the preferential treatment. In this study, a comprehensive ranking system was developed to determine the list and then applied to China. 151 OCs, for which occurrence data in the wastewater treatment plants were available, were selected as candidate OCs. Based on their occurrence, exposure potential and ecological effects, two different rankings of OCs were established respectively for groundwater recharge by surface infiltration and direct aquifer injection. Thirty-four OCs were regarded as having no risks while the remaining 117 OCs were divided into three groups: high, moderate and low priority OCs. Regardless of the recharge way, nonylphenol, erythromycin and ibuprofen were the highest priority OCs; their removal should be prioritized. Also the database should be updated as detecting technology is developed.

  11. Evaluation of volatile organic compound reduction technologies for metal coatings

    SciTech Connect

    Wang, Y.; Huang, E.W.

    1997-12-31

    Under the sponsorship of California Air Resources Board, AeroVironment Environmental Services, Inc. (AVES) is currently conducting a study to demonstrate a new zero-VOC Industrial Maintenance Metal Coating. This new technology can help the coating industry reduce emissions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). In a previous study conducted by AVES, current VOCs technologies available on the market for metal parts and product coatings were evaluated for compliance with the South Coast Air Quality Management District (SCAQMD) proposed Rule 1107 (Metal Parts and Product Coatings). There are low-VOC coating products available for industries of interest. For general metal coating applications, certain coating products can comply with current SCAQMD Rule 1107 VOC limits. Some of the low-VOC products that are considered as a substitute or an alternative to high-VOC petroleum-based products are summarized. The current available emerging technologies offer a great opportunity for emission reduction through a gradual shift from high to low/no VOC coatings. By phasing in low/no VOC coatings, industries will be able to reduce energy use and air emissions without installation of add-on controls.

  12. Volatile organic compound monitoring by photo acoustic radiometry

    SciTech Connect

    Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

    1995-12-01

    Two methods for sampling and analyzing volatile organics in subsurface pore gas were developed for use at the Hazardous Waste Disposal Site at Los Alamos National Laboratory. One is Thermal Desorption Gas Chromatography Mass Spectrometry (TDGCMS), the other is Photoacoustic Radiometry (PAR). Presented here are two years worth of experience and lessons learned as both techniques matured. The sampling technique is equally as important as the analysis method. PAR is a nondispersive infrared technique utilizing band pass filters in the region from 1 to 15 {mu}m. A commercial instrument, the Model 1302 Multigas Analyzer, made by Bruel and Kjaer, was adapted for field use. To use the PAR there must be some a priori knowledge of the constellation of analytes to be measured. The TDGCMS method is sensitive to 50 analytes. Hence TDGCMS is used in an initial survey of the site to determine what compounds are present and at what concentration. Once the major constituents of the soil-gas vapor plume are known the PAR can be configured to monitor for the five analytes of most interest. The PAR can analyse a sample in minutes, while in the field. The PAR is also quite precise in controlled situations.

  13. Production of volatile organic compounds by cyanobacteria Synechococcus sp.

    NASA Astrophysics Data System (ADS)

    Hiraiwa, M.; Abe, M.; Hashimoto, S.

    2014-12-01

    Phytoplankton are known to produce volatile organic compounds (VOCs), which contribute to environmental problems such as global warming and decomposition of stratospheric ozone. For example, picophytoplankton, such as Prochlorococcus and Synechococcus, are distributed in freshwater and oceans worldwide, accounting for a large proportion of biomass and primary production in the open ocean. However, to date, little is known about the production of VOCs by picophytoplankton. In this study, VOCs production by cyanobacteria Synechococcus sp. (NIES-981) was investigated. Synechococcus sp. was obtained from the National Institute for Environmental Studies (NIES), Japan, and cultured at 24°C in autoclaved f/2-Si medium under 54 ± 3 µE m-2 s-1 (1 E = 1 mol of photons) with a 12-h light and 12-h dark cycle. VOCs concentrations were determined using a purge-and-trap gas chromatograph-mass spectrometer (Agilent 5973). The concentrations of chlorophyll a (Chl a) were also determined using a fluorometer (Turner TD-700). Bromomethane (CH3Br) and isoprene were produced by Synechococcus sp. Isoprene production was similar to those of other phytoplankton species reported earlier. Isoprene was produced when Chl a was increasing in the early stage of the incubation period (5-15 days of incubation time, exponential phase), but CH3Br was produced when Chl a was reduced in the late stage of the incubation period (30-40 days of incubation time, death phase).

  14. Remediation of ground water containing volatile organic compounds and tritium

    SciTech Connect

    Shukla, S.N.; Folsom, E.N.

    1994-03-01

    The Trailer 5475 (T-5475) East Taxi Strip Area at Lawrence Livermore National Laboratory (LLNL), Livermore, California was used as a taxi strip by the US Navy to taxi airplanes to the runway from 1942 to 1947. Solvents were used in some unpaved areas adjacent to the East Taxi Strip for cleaning airplanes. From 1953 through 1976, the area was used to store and treat liquid waste. From 1962 to 1976 ponds were constructed and used for evaporation of liquid waste. As a result, the ground water in this area contains volatile organic compounds (VOCs) and tritium. The ground water in this area is also known to contain hexavalent chromium that is probably naturally occurring. Therefore, LLNL has proposed ``pump-and-treat`` technology above grade in a completely closed loop system. The facility will be designed to remove the VOCs and hexavalent chromium, if any, from the ground water, and the treated ground water containing tritium will be reinjected where it will decay naturally in the subsurface. Ground water containing tritium will be reinjected into areas with equal or higher tritium concentrations to comply with California regulations.

  15. Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong

    NASA Astrophysics Data System (ADS)

    Li, Yunchun

    Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they can be emitted from a variety of sources as well as formed from photochemical reactions of numerous precursors. This thesis work aims to improve the characterization of polar organic compounds and source apportionment analysis of fine organic carbon (OC) in Hong Kong, which consists of two parts: (1) An improved analytical method to determine monocarboxylic acids, dicarboxylic acids, ketocarboxylic acids, and dicarbonyls collected on filter substrates has been established. These oxygenated compounds were determined as their butyl ester or butyl acetal derivatives using gas chromatography-mass spectrometry. The new method made improvements over the original Kawamura method by eliminating the water extraction and evaporation steps. Aerosol materials were directly mixed with the BF 3/BuOH derivatization agent and the extracting solvent hexane. This modification improves recoveries for both the more volatile and the less water-soluble compounds. This improved method was applied to study the abundances and sources of these oxygenated compounds in PM2.5 aerosol samples collected in Hong Kong under different synoptic conditions during 2003-2005. These compounds account for on average 5.2% of OC (range: 1.4%-13.6%) on a carbon basis. Oxalic acid was the most abundant species. Six C2 and C3 oxygenated compounds, namely oxalic, malonic, glyoxylic, pyruvic acids, glyoxal, and methylglyoxal, dominated this suite of oxygenated compounds. More efforts are therefore suggested to focus on these small compounds in understanding the role of oxygenated

  16. A Parameterisation for the Dynamic Condensation of Semi-volatile Organic Compounds

    NASA Astrophysics Data System (ADS)

    Crooks, Matthew; Connolly, Paul

    2016-04-01

    The properties of aerosol particles in the atmosphere have a profound effect on both weather and climate but the relationship between them is poorly understood. One process that is particularly difficult to analyse and model is the formation of secondary organic aerosol (SOA) formed through the condensation of gases in the atmosphere. This effects number concentration, material properties and the size of the particles; all of which can change the number of cloud droplets. In addition to this, the gas phase of the organic compounds that form SOA undergo chemical reactions to produce very numerous different compounds which can be computational expensive to model individually. Attempts to model this process often rely on equilibrium absorptive partitioning theory to calculate the condensed phase of the organic compounds, however, equilibrium is a state that takes atmospherically unrealistic timescales to reach. The result is often an over prediction of condensed mass in small particles and subsequently an underestimation in large particles; both of which can significantly alter the supersaturation and consequently the number of cloud droplets. We present here a method of modelling approximately the dynamic condensation process to give more accurate condensed masses at atmospherically relevant timescales. By exploiting the properties of a widely applied logarithmically spaced volatility basis set along with various mathematical methods we have derived a method that produces vapour phase concentrations and time evolution of the particle size distributions which agree well with solution obtained through the vastly more computationally expensive direct numerical simulation.

  17. Speciation of organic compounds in aerosols from urban background sites in the winter season

    NASA Astrophysics Data System (ADS)

    Alves, Célia; Nunes, Teresa; Vicente, Ana; Gonçalves, Cátia; Evtyugina, Margarita; Marques, Telma; Pio, Casimiro; Bate-Epey, Frieda

    2014-12-01

    Winter aerosol samples were daily collected during one-month long campaign in Oporto and Coimbra. The high-volume PM2.5 samples were solvent extracted and their organic content separated into several functional groups, which were then analysed by gas chromatography-mass spectrometry. The organic compounds identified and quantified revealed some differences between samples from the two urban areas. In general, the levels of total hydrocarbons in the urban background station of Oporto were higher than those of Coimbra. Concentration ratios between specific compounds and the presence of molecular markers derived from petroleum, such as hopanes, pristane and phytane, point out vehicles as the main source of pollutants. The contribution of biogenic compounds, mainly hydrocarbons associated with the waxy cuticle of vegetation, is also observable in both cities. The benzo[a]pyrene equivalent daily values were frequently higher than 1 ng m- 3 in Oporto suggesting an additional cancer risk for the population. The PM2.5 mass attributable to vehicle emissions is higher in the background atmosphere of Oporto than in Coimbra. On weekends, biomass burning emissions could represent up to 74% of the organic carbon content of the urban aerosols.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27733773

  20. Measurement of emissions from air pollution sources. 3. C1-C29 organic compounds from fireplace combustion of wood.

    PubMed

    Schauer, J J; Kleeman, M J; Cass, G R; Simoneit, B R

    2001-05-01

    Organic compound emission rates for volatile organic compounds (VOC), gas-phase semivolatile organic compounds, and particle-phase organic compounds are measured from residential fireplace combustion of wood. Firewood from a conifer tree (pine) and from two deciduous trees (oak and eucalyptus) is burned to determine organic compound emissions profiles for each wood type including the distribution of the alkanes, alkenes, aromatics, polycyclic aromatic hydrocarbons (PAH), phenol and substituted phenols, guaiacol and substituted guaiacol, syringol and substituted syringols, carbonyls, alkanoic acids, resin acids, and levoglucosan. Levoglucosan is the major constituent in the fine particulate emissions from all three wood types, contributing 18-30% of the fine particulate organic compound emissions. Guaiacol (2-methoxyphenol), and guaiacols with additional substituents at position 4 on the molecule, and resin acids are emitted in significant quantities from pine wood combustion. Syringol (2,6-dimethoxyphenol) and syringols with additional substituents at position 4 on the molecule are emitted in large amounts from oak and eucalyptus firewood combustion, but these compounds are not detected in the emissions from pine wood combustion. Syringol and most of the substituted syringols are found to be semivolatile compounds that are present in both the gas and particle phases, but two substituted syringols that have not been previously quantified in wood smoke emissions, propionylsyringol and butyrylsyringol, are found exclusively in the particle phase and can be used to help trace hardwood smoke particles in the atmosphere. Benzene, ethene, and acetylene are often used as tracers for motor vehicle exhaust in the urban atmosphere. The contribution of wood smoke to the ambient concentrations of benzene, ethene, and acetylene could lead to an overestimate of the contribution of motor vehicle tailpipe exhaust to atmospheric VOC concentrations. PMID:11355184