WorldWideScience

Sample records for halogenated organic compounds

  1. Organic halogen compounds in the environment

    International Nuclear Information System (INIS)

    1979-07-01

    There are 20 research reports on selected problems concerning the analysis, the occurence, and the behaviour of a wide spectrum of organic halogen compounds. The work was carried out in the framework of the project 'Organic Halogen Compounds in the Environment', financed by the BMFT, between 1975 and 1978. (orig.) [de

  2. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

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

  3. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  4. PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

    Science.gov (United States)

    Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

  5. Halogenated organic compounds in archived whale oil: A pre-industrial record

    International Nuclear Information System (INIS)

    Teuten, Emma L.; Reddy, Christopher M.

    2007-01-01

    To provide additional evidence that several halogenated organic compounds (HOCs) found in environmental samples are natural and not industrially produced, we analyzed an archived whale oil sample collected in 1921 from the last voyage of the whaling ship Charles W. Morgan. This sample, which pre-dates large-scale industrial manufacture of HOCs, contained two methoxylated polybrominated diphenyl ethers (MeO-PBDEs), five halogenated methyl bipyrroles (MBPs), one halogenated dimethyl bipyrrole (DMBP), and tentatively one dimethoxylated polybrominated biphenyl (diMeO-PBB). This result indicates, at least in part, a natural source of the latter compounds. - Nine halogenated organic compounds have been detected in archived whale oil from the early 1920s

  6. Halogenated organic compounds in archived whale oil: A pre-industrial record

    Energy Technology Data Exchange (ETDEWEB)

    Teuten, Emma L. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: emma.teuten@plymouth.ac.uk; Reddy, Christopher M. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: creddy@whoi.edu

    2007-02-15

    To provide additional evidence that several halogenated organic compounds (HOCs) found in environmental samples are natural and not industrially produced, we analyzed an archived whale oil sample collected in 1921 from the last voyage of the whaling ship Charles W. Morgan. This sample, which pre-dates large-scale industrial manufacture of HOCs, contained two methoxylated polybrominated diphenyl ethers (MeO-PBDEs), five halogenated methyl bipyrroles (MBPs), one halogenated dimethyl bipyrrole (DMBP), and tentatively one dimethoxylated polybrominated biphenyl (diMeO-PBB). This result indicates, at least in part, a natural source of the latter compounds. - Nine halogenated organic compounds have been detected in archived whale oil from the early 1920s.

  7. Organic halogen compounds and surface water pollution; Composti organoalogenati alifatici e contaminazione delle acque superficiali

    Energy Technology Data Exchange (ETDEWEB)

    Cocchioni, M.; Pellegrini, M. G.; Grappasonni, I.; Nacciarriti, L.; Bernacchia, G. [Camerino, Univ. (Italy). Dipt. di Scienze Igienistiche e Sanitarie-Ambientali

    1997-03-01

    A brief review of the effects of halogenated organic compounds on the fluvial ecosystem is followed by results from a detailed monitoring of these substances in all the Marches Region rivers. The results show generally modest concentrations, except for sporadic peaks for chloroform. Sites revealing significant concentrations of halogenated organic compounds also manifested a worsening of the biological quality of the waters with lessening of E.B.I. Attention is drawn to the negative effects of indiscriminate chlorination of purification plant outputs, as this practice often fails to resolve infective problems and in itself adds toxicity to the watercourse.

  8. Radiocarbon content of synthetic and natural semi-volatile halogenated organic compounds

    International Nuclear Information System (INIS)

    Reddy, C.M.; Xu Li; Eglinton, T.I.; Boon, J.P.; Faulkner, D.J.

    2002-01-01

    New developments in molecular-level 14 C analysis techniques enable clues about natural versus commercial synthesis of trace organic contaminants. - Some halogenated organic compounds, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polybrominated diphenyl ethers (PBDEs), have been suggested to have natural sources but separating these compounds from their commercially synthesized counterparts is difficult. Molecular-level 14 C analysis may be beneficial since most synthetic compounds are manufactured from petrochemicals ( 14 C-free) and natural compounds should have 'modern' or 'contemporary' 14 C levels. As a baseline study, we measured, for the first time, the 14 C abundance in commercial PCB and PBDE mixtures, a number of organochlorine pesticides, as well as one natural product 2-(3', 5'-dibromo-2'-methoxyphenoxy)-3,5-dibromoanisole. The latter compound was isolated from a marine sponge and is similar in structure to a PBDE. All of the synthetic compounds were 14 C-free except for the pesticide toxaphene, which had a modern 14 C abundance, as did the brominated natural compound. The result for toxaphene was not surprising since it was commercially synthesized by the chlorination of camphene derived from pine trees. These results suggest that measuring the 14 C content of halogenated organic compounds may be quite useful in establishing whether organic compounds encountered in the environment have natural or synthetic origins (or both) provided that any synthetic counterparts derive from petrochemical feedstock

  9. Identifying bioaccumulative halogenated organic compounds using a nontargeted analytical approach: seabirds as sentinels.

    Directory of Open Access Journals (Sweden)

    Christopher J Millow

    Full Text Available Persistent organic pollutants (POPs are typically monitored via targeted mass spectrometry, which potentially identifies only a fraction of the contaminants actually present in environmental samples. With new anthropogenic compounds continuously introduced to the environment, novel and proactive approaches that provide a comprehensive alternative to targeted methods are needed in order to more completely characterize the diversity of known and unknown compounds likely to cause adverse effects. Nontargeted mass spectrometry attempts to extensively screen for compounds, providing a feasible approach for identifying contaminants that warrant future monitoring. We employed a nontargeted analytical method using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS to characterize halogenated organic compounds (HOCs in California Black skimmer (Rynchops niger eggs. Our study identified 111 HOCs; 84 of these compounds were regularly detected via targeted approaches, while 27 were classified as typically unmonitored or unknown. Typically unmonitored compounds of note in bird eggs included tris(4-chlorophenylmethane (TCPM, tris(4-chlorophenylmethanol (TCPMOH, triclosan, permethrin, heptachloro-1'-methyl-1,2'-bipyrrole (MBP, as well as four halogenated unknown compounds that could not be identified through database searching or the literature. The presence of these compounds in Black skimmer eggs suggests they are persistent, bioaccumulative, potentially biomagnifying, and maternally transferring. Our results highlight the utility and importance of employing nontargeted analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value in using environmental sentinels to proactively identify novel contaminants.

  10. Gas-liquid partitioning of halogenated volatile organic compounds in aqueous cyclodextrin solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ondo, Daniel; Barankova, Eva [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dohnal, Vladimir, E-mail: dohnalv@vscht.cz [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2011-08-15

    Highlights: > Binding of halogenated VOCs with cyclodextrins examined through g-l partitioning. > Complex stabilities reflect host-guest size matching and hydrophobic interaction. > Presence of halogens in the guest molecule stabilizes the binding. > Thermodynamic origin of the binding varies greatly among the systems studied. > Results obey the guest-CD global enthalpy-entropy compensation relationship. - Abstract: Gas-liquid partitioning coefficients (K{sub GL}) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, {alpha},{alpha},{alpha}-trifluorotoluene, and toluene in aqueous solutions of natural {alpha}-, {beta}-, and {gamma}-cyclodextrins (CDs) at temperatures from (273.35 to 326.35) K employing the techniques of headspace gas chromatography and inert gas stripping. The binding constants of the 1:1 inclusion complex formation between the VOCs and CDs were evaluated from the depression of the VOCs volatility as a function of CD concentration. The host-guest size matching and the hydrophobic interaction concept were used to rationalize the observed widely different affinity of the VOC-CD pairs to form the inclusion complex. The enthalpic and entropic component of the standard Gibbs free energy of complex formation as derived from the temperature dependence of the binding constant indicate the thermodynamic origin of the binding to vary greatly among the systems studied, but follow the global enthalpy-entropy compensation relationships reported previously in the literature.

  11. Halogenating reaction activity of aromatic organic compounds during disinfection of drinking water

    International Nuclear Information System (INIS)

    Guo Gaimei; Chen Xiaodong

    2009-01-01

    The halogenating reactions of five aromatic organic compounds (AOCs) with aqueous chlorine (HOCl/OCl - ) and aqueous bromine (HOBr/OBr - ) were studied with an aim to compare the formation properties of haloacetic acids (HAAs) for the corresponding chlorination or bromination reactions of AOCs, respectively. The experiment results indicated that the HAAs substitution efficiency for the bromination reactions of AOCs was greater than that for the chlorination reactions, and the formation of HAAs had a strong dependence on the chemical structure of AOCs. The chlorination or bromination reaction activities for the AOCs with electron donating functional groups were higher than that for them with electron withdrawing functional groups. The kinetic experiments indicated that the reactions of aqueous bromine with phenol were faster than those of aqueous chlorine with phenol and the halogen consumption exhibited rapid initial and slower consumption stages for the reactions of phenol with aqueous chlorine and bromine, respectively. In addition, the HAAs production for the chlorination reaction of phenol decreased with the increase of pH. These conclusions could provide the valuable information for the effective control of the disinfection by-products during drinking water treatment operation

  12. Exhaled human breath measurement method for assessing exposure to halogenated volatile organic compounds.

    Science.gov (United States)

    Pleil, J D; Lindstrom, A B

    1997-05-01

    The organic constituents of exhaled human breath are representative of blood-borne concentrations through gas exchange in the blood/breath interface in the lungs. The presence of specific compounds can be an indicator of recent exposure or represent a biological response of the subject. For volatile organic compounds (VOCs), sampling and analysis of breath is preferred to direct measurement from blood samples because breath collection is noninvasive, potentially infectious waste is avoided, and the measurement of gas-phase analytes is much simpler in a gas matrix rather than in a complex biological tissue such as blood. To exploit these advantages, we have developed the "single breath canister" (SBC) technique, a simple direct collection method for individual alveolar breath samples, and adapted conventional gas chromatography-mass spectrometry analytical methods for trace-concentration VOC analysis. The focus of this paper is to describe briefly the techniques for making VOC measurements in breath, to present some specific applications for which these methods are relevant, and to demonstrate how to estimate exposure to example VOCs on the basis of breath elimination. We present data from three different exposure scenarios: (a) vinyl chloride and cis-1,2-dichloroethene from showering with contaminated water from a private well, (b) chloroform and bromodichloromethane from high-intensity swimming in chlorinated pool water, and (c) trichloroethene from a controlled exposure chamber experiment. In all cases, for all subjects, the experiment is the same: preexposure breath measurement, exposure to halogenated VOC, and a postexposure time-dependent series of breath measurements. Data are presented only to demonstrate the use of the method and how to interpret the analytical results.

  13. The gas-chromatographic and gas-chromatographic-mass-spectrometric identification of halogen-containing organic compounds

    Science.gov (United States)

    Gidaspov, B. V.; Zenkevich, I. G.; Rodin, A. A.

    1989-09-01

    The problem of identifying halogen-containing organic compounds in their gas-chromatographic and gas-chromatographic-mass-spectrometric (GC-MS) determination in different materials has been examined. Particular attention has been paid not to the complete characterisation of methods for carrying out this analysis but to the most important problem of increasing the selectivity at the stages of sampling, separation, and interpretation of the gas-chromatographic and GC-MS information. The bibliography contains 292 references.

  14. Organic halogens in landfill leachates

    DEFF Research Database (Denmark)

    Grøn, C.; Christensen, J. B.; Jensen, Dorthe Lærke

    2000-01-01

    Using a group parameter, total organic halogens (TOX), high TOX concentrations were found in leachates and leachate contaminated groundwaters at two Danish mixed sanitary and hazardous waste sites. With commonly used screening procedures for organic contaminants, the individual halogenated organi...

  15. Removal of halogenated organic compounds in landfill gas by top covers containing zero-valent iron

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Winther, K.; Kjeldsen, Peter

    2000-01-01

    Transformation of gaseous CCl3F and CCl4 by zero-valent iron was studied in systems unsaturated with water under anaerobic conditionssin an N2 gas and in a landfill gas atmosphere. The transformation was studied in batch as well as flow-through column tests. In both systems, the transformation....... During continuous aerobic conditions, the transformation of CCl3F decreased toward zero. Model calculations show that use of zero-valent iron in landfill top covers is a potential treatment technology for emission reduction of halogenated trace compounds from landfills....

  16. Labelling of some iodinated organic compounds by halogen exchange in organic media

    International Nuclear Information System (INIS)

    Hallaba, E.; Suhybani, A.Al-; Khowaiter, S.Al-; Abdel-Wahid, M.

    1983-01-01

    Describes a general method for labelling Rose Bengal in an organic medium. An isotopic exchange technique with interactive iodine as carrier for radioiodine is used. The effect of temperature, carrier, pH of the solvent and solvent are investigated. The optimum conditions for maximum yield of exchange are: .0.2 micro mole carrier inactive iodine per one micro mole of Rose Bengal, reaction mixture is 10ml ethyl alcohol 96% as a solvent for Rose Bengal and 3ml of ether or carbon tetrachloride containing the inactive and radioiodine. In case of ether, the reaction is slow and is completed in two hours with maximum yield of 90% at boiling temperature. Addition of 175 λ of 1 M acetate buffer with carbon tetrachloride gave a yield of 90% in one hour. This method can be applied successfully to label any iodinated organic compound, such as hypuran, thyroxine, tyrosine or aliphatic fatty acids, for application in nuclear medicine. 10 Ref

  17. Evaluation of modulators and electron-capture detectors for comprehensive two-dimensional GC of halogenated organic compounds

    NARCIS (Netherlands)

    Kristenson, E.M.; Korytar, P.; Danielsson, C.; Kallio, M.; Brandt, M.; Makela, J.; Vreuls, R.J.J.; Beens, J.; Brinkman, U.A.T.

    2003-01-01

    Different cryogenic and a heated GC×GC modulator(s) were evaluated and compared for the analysis of high-boiling halogenated compounds. The cryogenic modulators investigated were: (i) the longitudinally modulated cryogenic system; (ii) the liquid-nitrogen-cooled jet modulator (KT2001); (iii) a

  18. Determination of tetrachloroethylene and other volatile halogenated organic compounds in oil wastes by headspace SPME GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, D.; Bezzi, R.; Torri, C.; Galletti, P.; Tagliavini, E. [Bologna Univ., Ravenna (Italy). Lab. of Chemistry, C.I.R.S.A

    2007-09-15

    Oil wastes and slops are complex mixtures of hydrocarbons, which may contain a variety of contaminants including tetrachloroethylene (perchloroethylene, PCE) and other volatile halogenated organic compounds (VHOCs). The analytical determination of PCE at trace levels in petroleum-derived matrices is difficult to carry out in the presence of large amounts of hydrocarbon matrix components. In the following study, we demonstrate that headspace solid-phase microextraction (HS-SPME) combined with GC-MS analysis can be applied for the rapid measurement of PCE concentration in oil samples. The HS-SPME method was developed using liquid paraffin as matrix matching reference material for external and internal calibration and optimisation of experimental parameters. The limit of quantitation was 0.05 mg kg{sup -1}, and linearity was established up to 25 mg kg{sup -1}. The HS-SPME method was extended to several VHOCs, including trichloroethylene (TCE) in different matrices and was applied to the quantitative analysis of PCE and TCE in real samples.

  19. Investigating the Impact of Ecological Succession on Fluxes of Halogenated Volatile Organic Compounds (HVOCs) from Retreating Glacier Forefields

    Science.gov (United States)

    Macdonald, M.; Young, D.; O'Doherty, S.; Wadham, J.

    2017-12-01

    The Arctic is one of the fastest warming regions of the Earth, with temperature increases of +7oC projected by 2100 under a mitigation emission scenario. These climate perturbations are forecast to cause the retreat of extensive glacial systems across Canada, Greenland, Svalbard and the Russian Arctic. This will reveal new proglacial land surfaces for microbial colonisation, ultimately succeeding to tundra over decades to centuries. A relatively unexplored dimension to these changes is their impact upon the emission and consumption of halogenated volatile organic compounds (HVOCs) from proglacial land surfaces. HVOCs are involved in several important atmospheric processes such as ozone destruction and aerosol formation and despite considerable research, uncertainties remain in the natural cycles of some of these compounds. Here, we investigated the influence of biological process on the fluxes of HVOCs from recently (chambers on surfaces spanning recently-exposed sediments, to approx. 100 yr old tundra in front of Midtre Lovenbreen glacier, Svalbard. In-field analysis of a suite of HVOCs was conducted using a GCMS (gas chromatograph mass spectrometer) with a custom-built pre-concentration system. HVOC concentrations were evaluated with reference to biological (e.g. cell numbers) and physio-chemical (e.g. water content) parameters of the land surface, in order to assess the importance of the microbial community on the net flux. Significant rates of consumption of some HVOC species and production of others was detected. Further laboratory incubations supported the findings in the field. Proglacial surfaces are, therefore, a previously unrecognised sink and source of various HVOCs that have the potential to increase in importance with projected future climate change.

  20. Is halogen content the most important factor in the removal of halogenated trace organics by MBR treatment?

    Science.gov (United States)

    Hai, Faisal I; Tadkaew, Nichanan; McDonald, James A; Khan, Stuart J; Nghiem, Long D

    2011-05-01

    This study investigated the relationship between physicochemical properties (namely halogen content and hydrophobicity) of halogenated trace organics and their removal efficiencies by a laboratory scale membrane bioreactor (MBR) under stable operating conditions. The reported results demonstrated a combined effect of halogen content and hydrophobicity on the removal. Compounds with high halogen content (>0.3) were well removed (>85%) when they possessed high hydrophobicity (Log D>3.2), while those with lower Log D values were also well removed if they had low halogen content (BIOWIN index (which is based on only biodegradation) or a more specific index such as the halogen content (which captures a chemical aspect) appeared insufficient to predict the removal efficiency of halogenated compounds in MBR. Experimental data confirmed that the ratio of halogen content and Log D, which incorporates two important physico-chemical properties, is comparatively more suitable. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Allergic contact dermatitis due to highly reactive halogenated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, F C; Ive, F A

    1983-11-01

    Ten cases of dermatitis in a fine organic chemicals plant are reported. These cases were all due to exposure to chemical compounds with reactive bromine or chlorine atoms. This type of chemical is always extremely irritant, but evidence is put forward to suggest that these cases were the result of allergic sensitization. Chemicals with reactive halogen atoms should always be handled with extreme care and patch testing should be approached with caution.

  2. Organic halogens in spruce forest throughfall

    DEFF Research Database (Denmark)

    Öberg, G.; Johansen, C.; Grøn, C.

    1998-01-01

    . No relationship between the position of the collectors and the forest edge or dominating wind-direction was found, suggesting that dry deposition was not a major source. The concentration of organic halogens was related to that of organic carbon and decreased from the tree-trunk and outwards. In addition......, the concentrations were higher during the growing season than during the dormant season. This indicates that the major part of the organic carbon and organic halogens in spruce forest throughfall originates from canopy leachates or other internal sources. (C) 1998 Elsevier Science Ltd.......Deposition of dissolved organic halogens by throughfall was determined in a small spruce forest site in Denmark (56 degrees 28'N, 8 degrees 24'E). The mean annual deposition of dissolved organic halogens was 377 g ha(-1)yr(-1), and larger than the general deposition by precipitation...

  3. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer–chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS)

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B.; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A.; Schimmelmann, Arndt

    2017-01-01

    Rationale: Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems.

  4. Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

    2010-05-15

    The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

  5. Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

    Directory of Open Access Journals (Sweden)

    J. Ofner

    2012-07-01

    Full Text Available Reactive halogen species (RHS, such as X·, X2 and HOX containing X = chlorine and/or bromine, are released by various sources like photo-activated sea-salt aerosol or from salt pans, and salt lakes. Despite many studies of RHS reactions, the potential of RHS reacting with secondary organic aerosol (SOA and organic aerosol derived from biomass-burning (BBOA has been neglected. Such reactions can constitute sources of gaseous organohalogen compounds or halogenated organic matter in the tropospheric boundary layer and can influence physicochemical properties of atmospheric aerosols.

    Model SOA from α-pinene, catechol, and guaiacol was used to study heterogeneous interactions with RHS. Particles were exposed to molecular chlorine and bromine in an aerosol smog-chamber in the presence of UV/VIS irradiation and to RHS, released from simulated natural halogen sources like salt pans. Subsequently, the aerosol was characterized in detail using a variety of physicochemical and spectroscopic methods. Fundamental features were correlated with heterogeneous halogenation, which results in new functional groups (FTIR spectroscopy, changes UV/VIS absorption, chemical composition (ultrahigh resolution mass spectroscopy (ICR-FT/MS, or aerosol size distribution. However, the halogen release mechanisms were also found to be affected by the presence of organic aerosol. Those interaction processes, changing chemical and physical properties of the aerosol are likely to influence e.g. the ability of the aerosol to act as cloud condensation nuclei, its potential to adsorb other gases with low-volatility, or its contribution to radiative forcing and ultimately the Earth's radiation balance.

  6. The adsorption and reaction of halogenated volatile organic compounds (VOC's) on metal oxides. 1998 annual progress report

    International Nuclear Information System (INIS)

    Goodman, D.W.; Haw, J.F.; Lunsford, J.

    1998-01-01

    'The goal of the research is to elucidate the properties of the materials responsible for the activation of halocarbons and the nature of the intermediates formed in the dissociative adsorption of this class of compounds. This information is essential for interpreting and predicting stoichiometric and catalytic pathways for the safe destruction of halocarbon pollutants. The specific objectives are: (1) to study the adsorption and reactivity of chloromethanes and chloroethanes on metal oxides; (2) to identify the reaction intermediates using spectroscopic methods; and (3) to develop kinetic models for the reaction of these halocarbons with oxide surfaces. This report summarizes work after 20 months of a 36-month project. Emphasis has been placed understanding the surfaces phases, as well as the bulk phases that are present during the reactions of chlorinated hydrocarbons with strongly basic metal oxides. Most of the research has been carried out with carbon tetrachloride.'

  7. Radiolysis of other organic compounds

    International Nuclear Information System (INIS)

    Pikaev, A.K.

    1986-01-01

    Peculiarities of radiolysis of organic halogen, phosphorus, sulfur and nitrogen (including amines, amides, nitriles et al.) compounds in liquid phase are discussed. Intermediate and stable finish products of radiolysis of the given compounds, properties and radiochemical yields of these products are considered

  8. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer-chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS).

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A; Schimmelmann, Arndt

    2017-03-30

    Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H 2 ) is responsible for non-quantitative H 2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer-Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of manganese metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. The modified EA-Cr/HTC reactor setup showed an overall H 2 -recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and

  9. Historical trends in occurrence and atmospheric inputs of halogenated volatile organic compounds in untreated ground water used as a source of drinking water

    Science.gov (United States)

    Shapiro, S.D.; Busenberg, E.; Focazio, M.J.; Plummer, Niel

    2004-01-01

    Analyses of samples of untreated ground water from 413 community-, non-community- (such as restaurants), and domestic-supply wells throughout the US were used to determine the frequency of detection of halogenated volatile organic compounds (VOCs) in drinking-water sources. The VOC data were compiled from archived chromatograms of samples analyzed originally for chlorofluorocarbons (CFCs) by purge-and-trap gas chromatography with an electron-capture detector (GC-ECD). Concentrations of the VOCs could not be ascertained because standards were not routinely analyzed for VOCs other than trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Nevertheless, the peak areas associated with the elution times of other VOCs on the chromatograms can be classified qualitatively to assess concentrations at a detection limit on the order of parts per quadrillion. Three or more VOCs were detected in 100% (percent) of the chromatograms, and 77.2% of the samples contained 10 or more VOCs. The maximum number of VOCs detected in any sample was 24. Modeled ground-water residence times, determined from concentrations of CFC-12, were used to assess historical trends in the cumulative occurrence of all VOCs detected in this analysis, as well as the occurrence of individual VOCs, such as CFC-11, carbon tetrachloride (CCl4), chloroform and tetrachloroethene (PCE). The detection frequency for all of the VOCs detected has remained relatively constant from approximately 1940 to 2000; however, the magnitude of the peak areas on the chromatograms for the VOCs in the water samples has increased from 1940 to 2000. For CFC-11, CCl4, chloroform and PCE, small peaks decrease from 1940 to 2000, and large peaks increase from 1940 to 2000. The increase in peak areas on the chromatograms from analyses of more recently recharged water is consistent with reported increases in atmospheric concentrations of the VOCs. Approximately 44% and 6

  10. Biogas from MSW landfill: Composition and determination of chlorine content with the AOX (adsorbable organically bound halogens) technique

    International Nuclear Information System (INIS)

    Rey, M.D.; Font, R.; Aracil, I.

    2013-01-01

    An exhaustive characterization of the biogas from some waste disposal facilities has been carried out. The analysis includes the main components (methane, carbon dioxide, nitrogen and oxygen) as well as trace components such as hydrogen sulphide, ammonia and VOCs (volatile organic compounds) including siloxanes and halogenated compounds. VOCs were measured by GC/MS (Gas Chromatography/Mass Spectrometry) using two different procedures: thermal desorption of the Tenax TA and Carbotrap 349 tubes and SPME (Solid Phase Micro-Extraction). A method has been established to measure the total halogen content of the biogas with the AOX (adsorbable organically bound halogens) technique. The equipment used to analyze the samples was a Total Organic Halogen Analyzer (TOX-100). Similar results were obtained when comparing the TOX (Total Organic Halogen) values with those obtained by GC/MS. The halogen content in all the samples was under 22 mg Cl/Nm 3 which is below the limit of 150 mg/Nm 3 proposed in the Spanish Regulations for any use of the biogas. The low chlorine content in the biogas studied, as well as the low content of other trace compounds, makes it suitable for use as a fuel for electricity generating engines

  11. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    Science.gov (United States)

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1983-09-20

    A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

  12. Rational design of organic semiconductors for texture control and self-patterning on halogenated surfaces

    KAUST Repository

    Ward, Jeremy W.; Li, Ruipeng; Obaid, Abdulmalik; Payne, Marcia M.; Smilgies, Detlef Matthias; Anthony, John Edward; Amassian, Aram; Jurchescu, Oana D.

    2014-01-01

    new materials. Here, the influence of the interactions at the interface between a halogenated organic semiconductor (OSC) thin film and a halogenated self-assembled monolayer on the formation of the crystalline texture directly affecting

  13. A Survey of Electron Impact Cross-Sections for Halogens and Halogen Compounds of Interest to Plasma Processing

    Science.gov (United States)

    Sharma, S. P.; Rao, M. V. V. S.; Arnold, James O. (Technical Monitor)

    1998-01-01

    Published electron impact cross section data on halogens Cl2, F2, and halogen containing compounds such as Cx Fy, HCl, Cx Cly Fz are reviewed and critically evaluated based on the information provided by various researchers. The present work reports data on electron impact excitation, ionization, dissociation, electron attachment, electron detachment, and photo detachment. Elastic scattering cross sections and data on bulk properties such as diffusion coefficients in various background gases are also evaluated. Since some of the cross sectional data is derived from indirect measurements such as drift velocity, care has been taken to reconcile the differences among the reported data with due attention to the measurement technique. In conclusion, the processes with no or very limited amount of data and questionable set of data are identified and recommendation for further research direction is made.

  14. Organic astatine compounds, their preparation and properties

    Energy Technology Data Exchange (ETDEWEB)

    Vasaros, L; Berei, K

    1985-01-01

    Aromatic astatine compounds of possible medical application were prepared by high energy substitutions, by astatine-halogen, and by electrophil astatine-hydrogen substitutions at the Joint Institute of Nuclear Researches, Dubna. Physico-chemical properties of organic astatine compounds such as boiling point and evaporation heat, and the refraction and dissociation energy of carbon-astatine bonds were determined experimentally by gas chromatography. The results are compared with extrapolated data. (V.N.). 41 refs.; 7 figs.; 5 tables.

  15. Flue gas corrosion through halogen compounds in fuel gas

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, R

    1987-04-01

    The halogens of chlorine and fluorine greatly influence the corrosion speed of metal materials. If small quantities of chlorinated and/or fluorinated hydrocarbons are present in fuel gas like in landfill gas, they must not result in enhanced corrosion of gas appliances. Data from literature and the initial results of tests run by the author indicate that quantities at about 10 mg/cbm (in terms of chlorine) can be assumed not to cause any noticeable acceleration of corrosion speed.

  16. Flame retardant synergism between molybdenum and halogen-containing compounds in unsaturated polyesters. [Smoke suppression

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, G.A.; Parker, L.E.; Marshall, P.J.

    1978-01-01

    Oxygen index results for a series of unsaturated polyesters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between molybdenum and halogen. With the halogenated compounds used, the magnitude of the effect was greater in the presence of bromine but was dependent on the type of compound. When dibromoneopentyl glycol was used as the bromine source, the synergistic effect exhibited by molybdenum oxide was comparable to that shown by antimony oxide. Since molybdenum oxide also acts as a smoke suppressant, it could offer a useful alternative to antimony oxide particularly in the light of probable changes in standards and regulatory control regarding smoke emission. 4 figures, 2 tables.

  17. Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

    Science.gov (United States)

    Lim, Seung Joo; Fox, Peter

    2014-02-01

    The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics. © 2013.

  18. Chiral halogenated Schiff base compounds: green synthesis, anticancer activity and DNA-binding study

    Science.gov (United States)

    Ariyaeifar, Mahnaz; Amiri Rudbari, Hadi; Sahihi, Mehdi; Kazemi, Zahra; Kajani, Abolghasem Abbasi; Zali-Boeini, Hassan; Kordestani, Nazanin; Bruno, Giuseppe; Gharaghani, Sajjad

    2018-06-01

    Eight enantiomerically pure halogenated Schiff base compounds were synthesized by reaction of halogenated salicylaldehydes with 3-Amino-1,2-propanediol (R or S) in water as green solvent at ambient temperature. All compounds were characterized by elemental analyses, NMR (1H and 13C), circular dichroism (CD) and FT-IR spectroscopy. FS-DNA binding studies of these compounds carried out by fluorescence quenching and UV-vis spectroscopy. The obtained results revealed that the ligands bind to DNA as: (Rsbnd ClBr) > (Rsbnd Cl2) > (Rsbnd Br2) > (Rsbnd I2) and (Ssbnd ClBr) > (Ssbnd Cl2) > (Ssbnd Br2) > (Ssbnd I2), indicating the effect of halogen on binding constant. In addition, DNA-binding constant of the Ssbnd and R-enantiomers are different from each other. The ligands can form halogen bonds with DNA that were confirmed by molecular docking. This method was also measured the bond distances and bond angles. The study of obtained data can have concluded that binding affinity of the ligands to DNA depends on strength of halogen bonds. The potential anticancer activity of ligands were also evaluated on MCF-7 and HeLa cancer cell lines by using MTT assay. The results showed that the anticancer activity and FS-DNA interaction is significantly dependent on the stereoisomers of Schiff base compounds as R-enantiomers displayed significantly higher activity than S-enantiomers. The molecular docking was also used to illustrate the specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction was proposed for them. In addition, molecular docking results indicated that there are three types of bonds (Hsbnd and X-bond and hX-bond) between synthesized compounds and base pairs of DNA.

  19. Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

    OpenAIRE

    Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride),...

  20. Changes in patterns of persistent halogenated compounds through a pelagic food web in the Baltic Sea

    DEFF Research Database (Denmark)

    Stephansen, Diana Agnete; Svendsen, Tore Christian; Vorkamp, Katrin

    2012-01-01

    The concentrations and patterns of persistent halogenated compounds (PHCs), including polychlorinated biphenyls (PCBs), DDT, hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and polybrominated diphenyl ethers (PBDEs) were examined in a pelagic food web from the southern Baltic Sea consisting...... for the assessment of PHC patterns, e.g. for tracing migratory fish....

  1. Tuning the viscosity of halogen free bulk heterojunction inks for inkjet printed organic solar cells

    NARCIS (Netherlands)

    Lamont, C.A.; Eggenhuisen, T.M.; Coenen, M.J.J.; Slaats, T.W.L.; Andriessen, R.; Groen, P.

    2015-01-01

    For the solution processing of organic photovoltaics on an industrial scale, the exclusion of halogenated solvents is a necessity. However, the limited solubility of most semiconducting polymer/fullerene blends in non-halogenated solvents results in ink formulations with low viscosities which poses

  2. Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

    Science.gov (United States)

    Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded. PMID:2339874

  3. Possibilities of analyzing dump and sewage gas, and determination of halogen and sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, R

    1985-01-01

    In connection with the utilization of refuse and sewage gas efficacions analytical methods are gaining increasing importance especially with regard to halogen and sulfur compounds. The paper describes various possibilities to determine those substances. Besides gas chromatography it takes into account classic analytical methods which can be superior in biogas analytics to modern physical processes. The advantages and disadvantages of each method are discussed and practical experiences obtained by their application reported.

  4. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems.

    Science.gov (United States)

    Tan, J; Allard, S; Gruchlik, Y; McDonald, S; Joll, C A; Heitz, A

    2016-01-15

    The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

    Science.gov (United States)

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1982-03-31

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

  6. Separation of halogens from uranium compounds by means of pyrohydrolysis and their determination by ion chromatography

    International Nuclear Information System (INIS)

    Pires, M.A.F.; Brandao Filho, D.; Abrao, A.

    1987-07-01

    This paper describs the determination of fluorine in nuclear grade uranium compounds by means of phyrohydrolysis. A stream of wet oxygem at a temperature of 900 to 1000 0 C is passed through a quartz tube where the powdered samples is put. The halogens are volatilized as their respective acids that are absorbed in a buffer solution or water. The measurements are made with ion-seletive eletrodes or by ion chromatography. The sensitivity is of 1μg F - /g and 5μg Cl - /g. The separation of fluorine from uranium compounds by diferent methods is discussed. (Author) [pt

  7. Chloric organic compound

    International Nuclear Information System (INIS)

    Moalem, F.

    2000-01-01

    Since many years ago, hazardous and toxic refuses which are results of human activities has been carelessly without any Biological and Engineering facts and knowledge discharged into our land and water. The effects of discharging those materials in environment are different. Some of refuse materials shows short and other has long-time adverse effects in our environment, Among hazardous organic chemical materials, chlorine, consider, to be the main element. Organic materials with chlorine is called chlorine hydrocarbon as a hazardous compound. This paper discuss the hazardous materials especially chloric organic compound and their misuse effects in environment and human being

  8. Computing sextic centrifugal distortion constants by DFT: A benchmark analysis on halogenated compounds

    Science.gov (United States)

    Pietropolli Charmet, Andrea; Stoppa, Paolo; Tasinato, Nicola; Giorgianni, Santi

    2017-05-01

    This work presents a benchmark study on the calculation of the sextic centrifugal distortion constants employing cubic force fields computed by means of density functional theory (DFT). For a set of semi-rigid halogenated organic compounds several functionals (B2PLYP, B3LYP, B3PW91, M06, M06-2X, O3LYP, X3LYP, ωB97XD, CAM-B3LYP, LC-ωPBE, PBE0, B97-1 and B97-D) were used for computing the sextic centrifugal distortion constants. The effects related to the size of basis sets and the performances of hybrid approaches, where the harmonic data obtained at higher level of electronic correlation are coupled with cubic force constants yielded by DFT functionals, are presented and discussed. The predicted values were compared to both the available data published in the literature and those obtained by calculations carried out at increasing level of electronic correlation: Hartree-Fock Self Consistent Field (HF-SCF), second order Møller-Plesset perturbation theory (MP2), and coupled-cluster single and double (CCSD) level of theory. Different hybrid approaches, having the cubic force field computed at DFT level of theory coupled to harmonic data computed at increasing level of electronic correlation (up to CCSD level of theory augmented by a perturbational estimate of the effects of connected triple excitations, CCSD(T)) were considered. The obtained results demonstrate that they can represent reliable and computationally affordable methods to predict sextic centrifugal terms with an accuracy almost comparable to that yielded by the more expensive anharmonic force fields fully computed at MP2 and CCSD levels of theory. In view of their reduced computational cost, these hybrid approaches pave the route to the study of more complex systems.

  9. Anaerobic biodegradation of halogenated and nonhalogenated N-, s-, and o-heterocyclic compounds in aquifer slurries

    Science.gov (United States)

    Adrian, Neal R.; Suflita, Joseph M.

    1994-01-01

    The fate of several halogenated and nonhalogenated heterocyclic compounds in anoxic aquifer slurries was investigated Substrate depletion and methane formation were monitored in serum bottle incubations by HPLC and GC, respectively Pyridine, pyrimidine, thiophene, and furan were not mineralized following an 11-month incubation, but the corresponding carboxylated or oxygenated compounds were That is, >74% of the theoretically expected amount of methane was recovered from nicotinic acid, uracil, or 2-furoic acid Chlorinated derivatives, like 2 chloro- or 6-chloronicotinic acid, as well as 4 chloro- and 5-chlorouracil resisted mineralization However, 5-bromouracil was reductively dehalogenated to stoichiometric amounts of uracil, whereas 2-chloropyrimidine was metabolized to a more polar unidentified compound that resisted further anaerobic biodegradation Microorganisms acclimated to 5-bromouracil were unable to transform 4 chloro or 5 chlorouracil These findings illustrate how the structure of heterocyclic contaminants influences their susceptibility to anaerobic decay

  10. The effect of halogen hetero-atoms on the vapor pressures and thermodynamics of polycyclic aromatic compounds measured via the Knudsen effusion technique

    International Nuclear Information System (INIS)

    Goldfarb, Jillian L.; Suuberg, Eric M.

    2008-01-01

    Knowledge of vapor pressures of high molar mass organics is essential to predicting their behavior in combustion systems as well as their fate and transport within the environment. This study involved polycyclic aromatic compounds (PACs) containing halogen hetero-atoms, including bromine and chlorine. The vapor pressures of eight PACs, ranging in molar mass from (212 to 336) g . mol -1 , were measured using the isothermal Knudsen effusion technique over the temperature range of (296 to 408) K. These compounds included those with few or no data available in the literature, namely: 1,4-dibromonaphthalene, 5-bromoacenaphthene, 9-bromoanthracene, 1,5-dibromoanthracene, 9,10-dibromoanthracene, 2-chloroanthracene, 9,10-dichloroanthracene, and 1-bromopyrene. Enthalpies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. An analysis is presented on the effects of the addition of halogen hetero-atoms to pure polycyclic aromatic hydrocarbons using these data as well as available literature data. As expected, the addition of halogens onto these PACs increases their enthalpies of sublimation and decreases their vapor pressures as compared to the parent compounds

  11. Boiling points of halogenated aliphatic compounds: a quantitative structure-property relationship for prediction and validation.

    Science.gov (United States)

    Oberg, Tomas

    2004-01-01

    Halogenated aliphatic compounds have many technical uses, but substances within this group are also ubiquitous environmental pollutants that can affect the ozone layer and contribute to global warming. The establishment of quantitative structure-property relationships is of interest not only to fill in gaps in the available database but also to validate experimental data already acquired. The three-dimensional structures of 240 compounds were modeled with molecular mechanics prior to the generation of empirical descriptors. Two bilinear projection methods, principal component analysis (PCA) and partial-least-squares regression (PLSR), were used to identify outliers. PLSR was subsequently used to build a multivariate calibration model by extracting the latent variables that describe most of the covariation between the molecular structure and the boiling point. Boiling points were also estimated with an extension of the group contribution method of Stein and Brown.

  12. Isostructurality and non-isostructurality in the series of halogenated organic crystal substances. The structure of Hal-aggregates

    International Nuclear Information System (INIS)

    Grineva, O.V.; Zorkij, P.M.

    2001-01-01

    Local characteristics and the type of intermolecular Hal-aggregates (ensembles of contacting halogen atoms of adjacent molecules) present in chemically similar halogenated crystal substances, differing only in the nature of Hal atoms, are compared. 23 series of halogenated hydrocarbons, including 57 crystal structures were considered. A clearly pronounced specificity of Hal-aggregates for compounds with a low and intermediate content of halogen was revealed. It was found that, as a rule, coordination number of Hal atom by Hal adjacent atoms increases in the series F-Cl-Br-I [ru

  13. Rational design of organic semiconductors for texture control and self-patterning on halogenated surfaces

    KAUST Repository

    Ward, Jeremy W.

    2014-05-15

    Understanding the interactions at interfaces between the materials constituting consecutive layers within organic thin-film transistors (OTFTs) is vital for optimizing charge injection and transport, tuning thin-film microstructure, and designing new materials. Here, the influence of the interactions at the interface between a halogenated organic semiconductor (OSC) thin film and a halogenated self-assembled monolayer on the formation of the crystalline texture directly affecting the performance of OTFTs is explored. By correlating the results from microbeam grazing incidence wide angle X-ray scattering (μGIWAXS) measurements of structure and texture with OTFT characteristics, two or more interaction paths between the terminating atoms of the semiconductor and the halogenated surface are found to be vital to templating a highly ordered morphology in the first layer. These interactions are effective when the separating distance is lower than 2.5 dw, where dw represents the van der Waals distance. The ability to modulate charge carrier transport by several orders of magnitude by promoting "edge-on" versus "face-on" molecular orientation and crystallographic textures in OSCs is demonstrated. It is found that the "edge-on" self-assembly of molecules forms uniform, (001) lamellar-textured crystallites which promote high charge carrier mobility, and that charge transport suffers as the fraction of the "face-on" oriented crystallites increases. The role of interfacial halogenation in mediating texture formation and the self-patterning of organic semiconductor films, as well as the resulting effects on charge transport in organic thin-film transistors, are explored. The presence of two or more anchoring sites between a halogenated semiconductor and a halogenated self-assembled monolayer, closer than about twice the corresponding van der Waals distance, alter the microstructure and improve electrical properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation......), atomic emission spectrometry, and mass spectrometry. For most environmental samples, chlorinated FAMEs must be enriched prior to GC. ELCD is a useful detection method for indicating halogenated FAMEs in the chromatograms, and tentative identification of the halogenated species can be obtained...

  15. Evaluation of trace organic contaminants in ultra-pure water production processes by measuring total organic halogen formation potential

    International Nuclear Information System (INIS)

    Urano, Kohei; Iwase, Yoko

    1984-01-01

    A new procedure for the determination of organic substances in water with high accuracy and high sensitivity was proposed, in which a hypochlorite is added to water, and the resultant total amount of organic halogen compounds (TOX formation potential) was measured, and it was applied to the evaluation of trace organic contaminants in ultra-pure water production process. In this investigation, the TOX formation potential of the raw water which was to be used for the ultra-pure water production process, intermediately treated water and ultra-pure water was measured to clarify the behavior of organic substances in the ultra-pure water production process and to demonstrate the usefulness of this procedure to evaluate trace organic contaminants in water. The measurement of TOX formation potential requires no specific technical skill, and only a short time, and gives accurate results, therefore, it is expected that the water quality control in the ultra-pure water production process can be performed more exactly by applying this procedure. (Yoshitake, I.)

  16. Biogeochemistry of Halogenated Hydrocarbons

    Science.gov (United States)

    Adriaens, P.; Gruden, C.; McCormick, M. L.

    2003-12-01

    Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of

  17. A survey of indoor pollution by volatile organo halogen compounds in Katsushika, Tokyo, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Amagai, T.; Olansandan; Matsushita, H. [University of Shizuoka, Shizuoka (Japan); Ono, M. [National Institute for Environmental Studies, Ibaraki (Japan); Nakai, S. [Yokohama National University, Yokohama (Japan); Tamura, K. [National Institute for Minamata Disease, Kumamoto (Japan); Maeda, K. [Tokyo Kasel University, Tokyo (Japan)

    1999-07-01

    A survey of indoor and outdoor pollution by 10 volatile organo halogen compounds (VOHCs) was performed in Katsushika Ward, Tokyo, Japan. Thirteen houses in February and 30 houses in July were sampled. Four consecutive 24-hour samples were collected by passive sampling from living room, kitchen, bedroom, bathroom and outdoors in February and July 1995. Indoor concentrations of carbon tetrachloride and trichloroethylene were at nearly the same as outdoor concentrations; therefore, it was concluded that indoor pollution by these compounds was primarily due to penetration of outdoor pollutants. Indoor concentrations of some VOHCs were considerably higher than outdoor concentrations and they varied widely between households. The list included: p-dichlorobenzene, tetrachloroethylene and tri halomethanes, for which emission sources were insect repellents, dry-cleaned clothes, and tap water, showers and bathtub water, respectively. Indoor concentrations of these compounds were higher in reinforced concrete houses than in wooden houses or wooden houses with mortar walls. This suggests that airtightness of the rooms is responsible for high indoor VOHC concentrations. (author)

  18. Algae form brominated organic compounds in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Huetteroth, A; Putschew, A; Jekel, M [Tech. Univ. Berlin (Germany)

    2004-09-15

    Monitoring of organic halogen compounds, measured as adsorbable organic bromine (AOBr) revealed seasonal high concentrations of organic bromine compounds in a surface water (Lake Tegel, Berlin, Germany). Usually, in late summer, concentrations are up to five times higher than during the rest of the year. The AOBr of the lake inflows (throughout the year less then 6 {mu}g/L) were always lower then those in the lake, which indicates a production of AOBr in the lake. A correlation of the AOBr and chlorophyll-a concentration (1) in the lake provides first evidence for the influence of phototrophic organisms. The knowledge of the natural production of organohalogens is relatively recent. Up to now there are more then 3800 identified natural organohalogen compounds that have been detected in marine plants, animals, and bacteria and also in terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and humans. Halogenated organic compounds are commonly considered to be of anthropogenic origin; derived from e.g. pharmaceuticals, herbicides, fungicides, insecticides, flame retardants, intermediates in organic synthesis and solvents. Additionally they are also produced as by-products during industrial processes and by waste water and drinking water disinfection. Organohalogen compounds may be toxic, persistent and/or carcinogenic. In order to understand the source and environmental relevance of naturally produced organobromine compounds in surface waters, the mechanism of the formation was investigated using batch tests with lake water and algae cultures.

  19. Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

    Energy Technology Data Exchange (ETDEWEB)

    Grimalt, Joan O.; Carrizo, Daniel; Otero, Raquel; Vizcaino, Esther [Institute of Environmental Assessment and Water Research (IDAeA-CSIC), Department of Environmental Chemistry, Barcelona, Catalonia (Spain); Howsam, Mike [Universite de Lille 2, Centre Universitaire de Mesure et d' Analyse, Faculte de Pharmacie, Lille (France); Rodrigues de Marchi, Mary Rosa [Institute of Chemistry UNESP, Department of Analytical Chemistry, Araraquara, SP (Brazil)

    2010-03-15

    A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000{mu}L were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes ({>=}300 {mu}L) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n=73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. (orig.)

  20. Volatile organic compounds

    International Nuclear Information System (INIS)

    Silseth, May Liss

    1998-01-01

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  1. Halogenated organic species over the tropical South American rainforest

    Directory of Open Access Journals (Sweden)

    S. Gebhardt

    2008-06-01

    Full Text Available Airborne measurements of the halogenated trace gases methyl chloride, methyl bromide and chloroform were conducted over the Atlantic Ocean and about 1000 km of pristine tropical rainforest in Suriname and French Guyana (3–6° N, 51–59° W in October 2005. In the boundary layer (0–1.4 km, maritime air masses, advected over the forest by southeasterly trade winds, were measured at various distances from the coast. Since the organohalogens presented here have relatively long atmospheric lifetimes (0.4–1.0 years in comparison to the advection times from the coast (1–2 days, emissions will accumulate in air traversing the rainforest. The distributions of methyl chloride, methyl bromide and chloroform were analyzed as a function of time the air spent over land and the respective relationship used to determine net fluxes from the rainforest for one week within the long dry season.

    Net fluxes from the rainforest ecosystem have been calculated for methyl chloride and chloroform as 9.5 (±3.8 2σ and 0.35 (±0.15 2σμg m-2 h−1, respectively. No significant flux was observed for methyl bromide within the limits of these measurements.

    The global budget of methyl chloride contains large uncertainties, in particular with regard to a possible source from tropical vegetation. Our measurements are used in a large-scale approach to determine the net flux from a tropical ecosystem to the planetary boundary layer. The obtained global net flux of 1.5 (±0.6 2σ Tg yr-1 for methyl chloride is at the lower end of current estimates for tropical vegetation sources, which helps to constrain the range of tropical sources and sinks (0.82 to 8.2 Tg yr-1 from tropical plants, 0.03 to 2.5 Tg yr-1 from senescent/dead leaves and a sink of 0.1 to 1.6 Tg yr-1 by soil uptake. Nevertheless, these results show that the contribution of the rainforest ecosystem is the major source in the

  2. Large area inkjet printing for organic photovoltaics and organic light emitting diodes using non-halogenated ink formulations

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; Coenen, M.J.J.; Slaats, M.W.L.; Groen, W.A.

    2014-01-01

    The transfer of laboratory scale solution processing of organic electronics to large area roll-to-roll production requires the use of up-scalable deposition techniques. Furthermore, industrial production demands the omission of halogenated and other harmful solvents. Here, the authors discuss large

  3. Halogens in pore water of peat bogs – the role of peat decomposition and dissolved organic matter

    Directory of Open Access Journals (Sweden)

    H. Biester

    2006-01-01

    Full Text Available Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC (chlorine and IC-ICP-MS (bromine and iodine. Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM is the predominant mechanism of iodine and bromine release from peat.

  4. Basic aspects of photocatalytic detoxification of organic halogens by TiO2 nanocrystallites. Photolytic and radiolytic investigations

    International Nuclear Information System (INIS)

    Rabani, J.

    1998-01-01

    Various forms of TiO 2 (nanocrystallites in colloid solutions, powders and layers) are considered as promising photocatalysts for detoxification of persistent organic chemicals which are present as pollutants in waste water effluents from industrial manufacturers and even from regular households. Such pollutants penetrate and reach water sources and must be removed or destroyed in order to prevent damage to people or to the environment. Some of the toxins, such as organic halogenated compounds is difficult to remove by moderate chemical redox reactions, but can be mineralized by a free radical mechanism. Pilot plants for detoxification of industrial wastes on TiO 2 surface are currently being tested in several countries. In view of this recent development it is of particular interest to investigate yields of the reactive intermediates and reaction mechanisms of reactions of representative organic substrates. Such work is presently going on in many laboratories. In the present contribution we focus on the nature of the primary oxidizing species and the possible ways to increase photolytic yields, with particular attention to chain reactions in organic halogen compounds. Although the work concerns photocatalysis, radiation chemistry may provide useful results regarding kinetic parameters and comparative tests. Thus, comparison between photocatalytic (TiO 2 ), radiolytic and chemical hydroxylations of phenol provides evidence that the reactive hydroxylation agent is an OH· radical adsorbed to the TiO 2 surface. The initial photochemical products are conduction band electrons and valence band holes in the TiO 2 nanocrystallites, which become 'trapped' within less than 30 ps. (author)

  5. Quadrupole coupling constants and isomeric Moessbauer shifts for halogen-containing gold, platinum, niobium, tantalum and antimony compounds

    International Nuclear Information System (INIS)

    Poleshchuk, O. K.; Branchadell, V.; Ritter, R. A.; Fateev, A. V.

    2008-01-01

    We have analyzed by means of Density functional theory calculations the nuclear quadrupole coupling constants of a range of gold, antimony, platinum, niobium and tantalum compounds. The geometrical parameters and halogen nuclear quadrupole coupling constants obtained by these calculations substantially corresponded to the data of microwave and nuclear quadrupole resonance spectroscopy. An analysis of the quality of the calculations that employ pseudo-potentials and all-electron basis sets for the halogen compounds was carried out. The zero order regular approximation (ZORA) method is shown to be a viable alternative for the calculation of halogen coupling constants in molecules. In addition, the ZORA model, in contrast to the pseudo-potential model, leads to realistic values of all metal nuclear quadrupole coupling constants. From Klopman's approach, it follows that the relationship between the electrostatic bonding and covalent depends on the nature of the central atom. The results on Moessbauer chemical shifts are also in a good agreement with the coordination number of the central atom.

  6. Quadrupole coupling constants and isomeric Moessbauer shifts for halogen-containing gold, platinum, niobium, tantalum and antimony compounds

    Energy Technology Data Exchange (ETDEWEB)

    Poleshchuk, O. K., E-mail: poleshch@tspu.edu.ru [Tomsk State Pedagogical University (Russian Federation); Branchadell, V. [Universitat Autonoma de Barcelona, Departament de Quimica (Spain); Ritter, R. A.; Fateev, A. V. [Tomsk State Pedagogical University (Russian Federation)

    2008-01-15

    We have analyzed by means of Density functional theory calculations the nuclear quadrupole coupling constants of a range of gold, antimony, platinum, niobium and tantalum compounds. The geometrical parameters and halogen nuclear quadrupole coupling constants obtained by these calculations substantially corresponded to the data of microwave and nuclear quadrupole resonance spectroscopy. An analysis of the quality of the calculations that employ pseudo-potentials and all-electron basis sets for the halogen compounds was carried out. The zero order regular approximation (ZORA) method is shown to be a viable alternative for the calculation of halogen coupling constants in molecules. In addition, the ZORA model, in contrast to the pseudo-potential model, leads to realistic values of all metal nuclear quadrupole coupling constants. From Klopman's approach, it follows that the relationship between the electrostatic bonding and covalent depends on the nature of the central atom. The results on Moessbauer chemical shifts are also in a good agreement with the coordination number of the central atom.

  7. Relationship between centrifugation and drying of sludge and the organic halogens

    Directory of Open Access Journals (Sweden)

    Karel Hrich

    2010-01-01

    Full Text Available This work is focused on determination of adsorbable organic halogens (AOX concentration in the digested sludge from the sewage treatment plant and the losses of this component during dewatering and drying of sludge. Drying of the sludge from wastewater treatment plant is not extended too much in Czech Republic. In this work, the AOX are monitored, because AOX is one of the limits restraining use of the sludge on an agricultural land. Another reason is technological demand for using the sludge in cement processing, because chlorine in AOX can cause decrease in a heat transfer effect in a cement kiln. It is clear from the results that both centrifuged and dried sludge from the sewage treatment plant Brno fulfilled limits for using sludge on agriculture land. They can also be composted, in case they meet other requirements. If not, it is a possibility of co-incineration in cement kiln. In such case, limit for total chlorine including the AOX is required too. This limit was not exceeded. Another aim was to calculate a mass balance of AOX during the centrifugation and drying processes. It was found out, that after centrifugation the main part of AOX remained in the centrifuged sludge (96.4 %. The rest was drawn-off with reject water. 60 % of AOX in the reject water were dissolved compounds. A similar situation occurred during the drying process. More than 99 % of AOX was bound in the dried sludge. The air and vaporised water contained such quantity of AOX, which corresponded with the amount of the dust in the air and the amount of particles of sludge in vaporised water.

  8. Generation and alteration of the defects induced by particle irradiation and electromagnetic radiation in alkali halogen compounds

    International Nuclear Information System (INIS)

    Nistor, L.C.

    1979-01-01

    Interactions between electron beams, CO 2 - laser radiation and alkali halogen compound have led to interesting results: 1. The development of two types of F-centre respectively in normal lattice or near the dislocations. 2. The beginning of metal colloids development process at low temperature when a thermal treatment is applied. 3. An experimental confirmation of the Pooley-Hersh model for crystal defects has been brought up. 4. The surface penetration is an explosive process. 5. Surface polygonizations were also investigated. A model has been proposed to describe the destructive channels development within alkali halogen crystals with molecular anions impurities of less than 10 ppm. KCl monocrystals of advanced purity level was prepared for building up passive optical components of strong CO 2 lasers. (author)

  9. Apparatus for washing out halogens

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M; Hahn, J; Kroenig, W

    1941-03-26

    An apparatus is described for washing out of halogens and the like or liquid halogen compounds from the products, which are formed on pressure hydrogenation or splitting of carbon-containing material in the presence of halogens or halogen compounds, consisting of a washing apparatus installed between the reaction vessel and the hot separator, which is inclined in relatively small space for steam regulation and contains, with the steam, arranged baffles, especially spirals.

  10. Reactive and organic halogen species in three different European coastal environments

    Directory of Open Access Journals (Sweden)

    C. Peters

    2005-01-01

    Full Text Available We present results of three field campaigns using active longpath DOAS (Differential Optical Absorption Spectroscopy for the study of reactive halogen species (RHS BrO, IO, OIO and I2. Two recent field campaigns took place in Spring 2002 in Dagebüll at the German North Sea Coast and in Spring 2003 in Lilia at the French Atlantic Coast of Brittany. In addition, data from a campaign in Mace Head, Ireland in 1998 was partly re-evaluated. During the recent field campaigns volatile halogenated organic compounds (VHOCs were determined by a capillary gas chromatograph coupled with an electron capture detector and an inductively coupled plasma mass spectrometer (GC/ECD-ICPMS in air and water. Due to the inhomogeneous distribution of macroalgae at the German North Sea Coast we found a clear connection between elevated levels of VHOCs and the appearance of macroalgae. Extraordinarily high concentrations of several VHOCs, especially CH3I and CH3Br of up to 1830 pptv and 875 pptv, respectively, were observed at the coast of Brittany, demonstrating the outstanding level of bioactivity there. We found CH2I2 at levels of up to 20 pptv, and a clear anti-correlation with the appearance of IO. The IO mixing ratio reached up to 7.7±0.5 ppt(pmol/mol during the day, in reasonable agreement with model studies designed to represent the meteorological and chemical conditions in Brittany. For the two recent campaigns the DOAS spectra were evaluated for BrO, OIO and I2, but none of these species could be clearly identified (average detection limits around 2 ppt, 3 ppt, 20 ppt, resp., significantly higher in individual cases. Only in the Mace Head spectra evidence was found for the presence of OIO. Since macroalgae under oxidative stress are suggested to be a further source for I2 in the marine boundary layer, we re-analyzed spectra in the 500–600 nm range taken during the 1998 PARFORCE campaign in Mace Head, Ireland, which had not previously been analyzed for I2. We

  11. Reactive and Organic Halogen Species in Three Different European Coastal Environments

    Science.gov (United States)

    Platt, U.; Peters, C.; Pechtl, S.

    2005-12-01

    Within this contribution results of three field campaigns using active longpath DOAS (Differential Optical Absorption Spectroscopy) for the study of reactive halogen species (RHS) BrO, IO, OIO and I2 are presented. Two recent field campaigns took place in Spring 2002 in Dagebuell at the German North Sea Coast and 2003 in Lilia at the French Atlantic Coast of Brittany. Both sites represent coastal environments, characterized by extended intertidal zones and a moderately polluted atmosphere, with NO2 levels of up to 8 ppb. However, the sites show strong differences in their respective bioactivity. A great variety of macroalgae appeared over extended areas in Brittany, whereas algae were localized in small and rare spots at the German North Sea Coast. During these field campaigns volatile halogenated organic compounds (VHOCs) were determined by GC/ECD-ICPMS in air and water. Due to the spatial distribution of macroalgae at the German North Sea Coast clear evidence was for a connection between elevated levels of VHOCs and the appearance of macroalgae. Extraordinarily high concentrations of several VHOCs, specially CH3I and CH3Br of up to 1830 pptv and 875 pptv, respectively, were observed at the coast of Brittany, demonstrating the outstanding level of bioactivity there. CH2I2, an important source species for reactive iodine in the atmosphere due its short photolytic lifetime of only a few minutes, could be detected of up to 20 pptv. The IO mixing ratio reached up to 7.7±0.5 ppt (pmol/mol) during the day, in reasonable agreement with model studies designed to represent the meteorological and chemical conditions in Brittany. Since macroalgae under oxidative stress are suggested to be a further source for I2 in the marine boundary layer, spectra in the 500-600 nm range were re-analyzed taken during the 1998 PARFORCE campaign in Mace Head, Ireland, which had not previously been analyzed for I2. Molecular iodine could be clearly identified above the detection limit (~20

  12. Quantitative structure-activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: wing spot test of Drosophila melanogaster.

    Science.gov (United States)

    Chroust, Karel; Pavlová, Martina; Prokop, Zbynek; Mendel, Jan; Bozková, Katerina; Kubát, Zdenek; Zajícková, Veronika; Damborský, Jiri

    2007-02-01

    Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.

  13. Extraterrestrial Organic Compounds in Meteorites

    Science.gov (United States)

    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.

  14. Experiments on the VERONA test facility on formation and decomposition of polyhalogenated dioxins and furans and other organic halogen compounds in the combustion process; Untersuchungen an der Technikumsanlage VERONA zur Bildung und zum Abbau von polyhalogenierten Dioxinen und Furanen und anderen Organohalogenverbindungen in Verbrennungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, D.

    2002-09-01

    The study examines measures to reduce dioxin formation in thermal waste treatment. The VERONA pilot plant (VErbrennungsanlage mit feststehendem ROst und getrennter NAchbrennkammer - incineration plant with stationary grate and separate post-combustion chamber) was developed to carry out practical experiments. The experiments were conducted using wood and propane as basic combustible materials and with controlled dosage of various bromine-, chlorine- and copper-containing compounds. The behaviour of the following compounds was studied in the combustion chamber, after the post-combustion chamber and after the heat exchanger: PCPh, PBrPh, PCBz, PBrBz, PCDD/F and PBDD/F. Experiments involving the variation of various primary measures (moisture content of combustible material, air supply, temperature in the combustion chamber, quality of post-combustion, quantities and structures of halogen compounds) have shown that the quality of post-combustion plays a much greater role than the other measures. For this reason, a search was launched for indicators which can be measured readily and by means of which the quality of post-combustion in terms of organohalide decomposition can be evaluated, and which correlate closely with the dioxin concentrations after the heat exchanger. It became apparent that the congeners of the chlorophenols and of the chlorobenzenes, measured in various incineration stages, are not suited, nor is the CO content. (orig.)

  15. Students' Categorizations of Organic Compounds

    Science.gov (United States)

    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…

  16. Solar driven production of toxic halogenated and nitroaromatic compounds in natural seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, Paola [Dipartimento di Chimica Analitica, Universita di Torino, via P. Giuria 5, 10125 Torino (Italy)], E-mail: paola.calza@unito.it; Massolino, Cristina; Pelizzetti, Ezio; Minero, Claudio [Dipartimento di Chimica Analitica, Universita di Torino, via P. Giuria 5, 10125 Torino (Italy)

    2008-07-15

    Natural seawater (NSW) sampled in March and June 2007 in the Gulf of Trieste, Italy, has been spiked with phenol and irradiated in a device simulating solar light spectrum and intensity. Opposite to the case of artificial seawater, for which phenol is slightly degraded by direct photolysis, in NSW the phenol degradation mediated by natural photosensitizers occurs, forming several secondary pollutants, including hydroxyderivatives (1,4-benzoquinone, resorcinol), three chlorophenol isomers, 2,3-dichlorophenol, 2- and 4-bromophenol, 2- and 4-nitrophenol, and several condensed products (2 and 4-phenoxyphenol, 2,2'-, 4,4'- and 2,4-bisphenol). These compounds are toxic to bacteria and other living organisms. Ecotoxicologic effect has been evaluated by using the Vibrio Fischeri luminescent bacteria assay. This technique uses marine organisms, and it is therefore well suited for the study on marine samples. A correlation exists between the intermediates evolution and the toxicity profile, as the largest toxicity is observed when compounds with the lower EC50 (halophenols, phenoxyphenols) are formed at higher concentration.

  17. Solar driven production of toxic halogenated and nitroaromatic compounds in natural seawater

    International Nuclear Information System (INIS)

    Calza, Paola; Massolino, Cristina; Pelizzetti, Ezio; Minero, Claudio

    2008-01-01

    Natural seawater (NSW) sampled in March and June 2007 in the Gulf of Trieste, Italy, has been spiked with phenol and irradiated in a device simulating solar light spectrum and intensity. Opposite to the case of artificial seawater, for which phenol is slightly degraded by direct photolysis, in NSW the phenol degradation mediated by natural photosensitizers occurs, forming several secondary pollutants, including hydroxyderivatives (1,4-benzoquinone, resorcinol), three chlorophenol isomers, 2,3-dichlorophenol, 2- and 4-bromophenol, 2- and 4-nitrophenol, and several condensed products (2 and 4-phenoxyphenol, 2,2'-, 4,4'- and 2,4-bisphenol). These compounds are toxic to bacteria and other living organisms. Ecotoxicologic effect has been evaluated by using the Vibrio Fischeri luminescent bacteria assay. This technique uses marine organisms, and it is therefore well suited for the study on marine samples. A correlation exists between the intermediates evolution and the toxicity profile, as the largest toxicity is observed when compounds with the lower EC50 (halophenols, phenoxyphenols) are formed at higher concentration

  18. Compound deterioration properties of non-halogen flame-resisting cables

    International Nuclear Information System (INIS)

    Yamamoto, Yasuaki; Yagyu, Hideki; Onishi, Takao; Kamiharako, Shinji

    1984-01-01

    Conventional flame-resisting cables release harmful gas such as hydrogen chloride and smoke on burning. To improve this disadvantage, the cables for nuclear power plants using new non-halogen flame-resisting insulating material have been developed. In this experiment, the non-halogen flame-resisting cables were subjected to the environmental test with varying test conditions. The test conditions included the order of exposure (heat treatment, γ-ray irradiation and steam exposure) and dose rate. After the environmental test, the mechanical and electrical properties of the samples were measured. In all test conditions, the samples did not crack in bending, and withstood the bending and withstand-voltage in-water test. The tensile strength and a.c. breakdown voltage did not change, and were stable. The elongation decreased greatly, but maintained the value of about 100 %, and the volumetric resistivity decreased by only one figure. It was confirmed that these cables were able to withstand various environmental tests. (Yoshitake, I.)

  19. Determination of adsorbable organic halogens in surface water samples by combustion-microcoulometry versus combustion-ion chromatography titration.

    Science.gov (United States)

    Kinani, Aziz; Sa Lhi, Hacène; Bouchonnet, Stéphane; Kinani, Said

    2018-03-02

    Adsorbable Organic Halogen (AOX) is an analytical parameter of considerable interest since it allows to evaluate the amount of organohalogen disinfection by-products (OXBPs) present in a water sample. Halogen speciation of AOX into adsorbable organic chlorine, bromine and iodine, respectively AOCl, AOBr and AOI, is extremely important since it has been shown that iodinated and brominated organic by-products tend to be more toxic than their chlorinated analogues. Chemical speciation of AOX can be performed by combustion-ion chromatography (C-IC). In the present work, the effectiveness of the nitrate wash according to ISO 9562 standard method protocol to eliminate halide ions interferences was firstly examined. False positive AOX values were observed when chloride concentration exceeded 100 ppm. The improvements made to the washing protocol have eliminated chloride interference for concentrations up to 1000 ppm. A C-IC method for chemical speciation of AOX into AOCl, AOBr, and AOI has been developed and validated. The most important analytical parameters were investigated. The following optimal conditions were established: an aqueous solution containing 2.4 mM sodium bicarbonate/2.0 mM sodium carbonate, and 2% acetone (v/v) as mobile phase, 2 mL of aqueous sodium thiosulfate (500 ppm) as absorption solution, 0.2 mL min -1 as water inlet flow rate for hydropyrolysis, and 10 min as post-combustion time. The method was validated according to NF T90-210 standard method. Calibration curves fitted through a quadratic equation show coefficients of determination (r 2 ) greater than 0.9998, and RSD less than 5%. The LOQs were 0.9, 4.3, and 5.7 μg L -1 Cl for AOCl, AOBr, and AOI, respectively. The accuracy, in terms of relative error, was within a ± 10% interval. The applicability of the validated method was demonstrated by the analysis of twenty four water samples from three rivers in France. The measurements reveals AOX amounts above 10

  20. Quantitative prediction of solvation free energy in octanol of organic compounds.

    Science.gov (United States)

    Delgado, Eduardo J; Jaña, Gonzalo A

    2009-03-01

    The free energy of solvation, DeltaGS0, in octanol of organic compounds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a DeltaGS0 range from about -50 to 0 kJ.mol(-1). The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ.mol(-1), just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

  1. Novel enhancement of thin-form-factor galvanic cells: Probing halogenated organic oxidizers and metal anodes

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas-Valencia, Andres M.; Adornato, Lori; Short, R. Timothy; Langebrake, Larry [SRI International, Engineering and Systems Division, Marine Technology Program, 140 Seventh Avenue South, St Petersburg, FL 33701 (United States)

    2008-09-15

    The work reported herein demonstrates a novel method to improve the overall performance of thin-form-factor galvanic cells, fabricated via micro-electromechanical systems (MEMS) processes. Use of solid, low cost, cyclic-halogenated, organic catholyte materials permits water activation of cells consisting of metal anode and catalytic platinum positive electrodes. Similar cells, employing aluminum and zinc anodes, have been activated using sodium hypochlorite (NaClO) solutions, i.e. bleach, in the past. The oxidizers chosen for this study (bromo-, chloro- and iodo-succinimides, and sodium dichloroisocyanuric acid) supply the cathode's oxy-halogenated ions when in contact with water. Zinc, magnesium and aluminum anodes are utilized to fabricate galvanic cells. A comparison between these anodes, coupled with various oxidizers, is included herein. Results using aluminum anode cells show that, even though the utilization efficiency of the catholyte reagents is low (faradic efficiencies between 16 and 19%), the performance of the new water-activated cells (6 cm x 6 cm x 0.25 cm) is superior when compared to those activated with bleach. For instance, operational lives of 6 h (activation with 10% NaClO solution) increase to more than 30 h using the new approach, with a 100-ohm-load. It is also shown that specific energies of 90-110 Wh kg{sup -1} (calculated to include both reagent and packaging mass) could be obtained using the described approach with current draws between 10 and 20 mA. The specific energies obtained suggest that novel MEMS-type cells could have much broader application than low-current, bleach-activated cells. (author)

  2. Decomposition of halogenated organic chemicals in ionic liquid by ionizing radiation

    International Nuclear Information System (INIS)

    Kimura, A.; Taguchi, M.; Kojima, T.; Nagaishi, R.; Hiratsuka, H.

    2006-01-01

    Introduction: Halogenated organic chemicals such as polychlorodibenzo-p-dioxin, polychlorobiphenyls and hexachlorobenzene are widely spread in water environment. These pollutants are persistent against advanced oxidation treatments such as ozone/UV, ozone/hydrogen peroxide, ionizing radiation and photocatalysts. The ionizing radiation, however, can also produce homogeneously and quantitatively reducing species in water. On the other hand, room temperature ionic liquids (RTILs) have unique properties such as nonflammable, high polarity, low melting point, hydrophobicity and wide electrochemical window. The combined method of reduction by ionizing radiation and RTILs is investigated as a new environmental conservation technology. Experimental: Chlorophenol (CP) is selected as model chemicals having the main frame of halogenated organic chemicals. Each o - , m - and p-CP were irradiated with 60 Co γ-ray in each diethylmethyl(2-methoxy-ethyl)ammonium bis(trifluoromethylsulfonyl)imide (DEMMA- TFSI), diethylmethyl(2-methoxyethyl)-ammonium tetrafluoroborate (DEMMA-BF4), methanol and ethanol as solvent. Decomposition of CP and formation of irradiation products were studied using HPLC, LC-MS and ion chromatography. Results and discussion: Concentration of CP in each solution decreased as a function of dose. G-value was estimated from the slope at the primary stage of the decomposition curve. The G(-CP) and G(Phenol) were shown in Table 1. G(-CP) in the aliphatic alcohols was 0.21 to 0.37, which is lower than G-value of reducing species in the alcohols, e.g. G=1.0 to 1.5 for solvated electron. Since the rate constant for reaction of CP with hydrated electron is 1.3 x 10 9 mol -1 ·dm 3 ·s -1 , the reverse reaction is considered to attribute. G(-CP) in DEMMA-TFSI or DEMMA-BF4 was about 2 to 3 times higher than that in each alcohol. Lifetime of the reducing species in RTILs would be longer than that in each alcohol. G(-CP) in DEMMA-TFSI decreased by adding acetone or oxygen

  3. Halogenated methanesulfonic acids: A new class of organic micropollutants in the water cycle.

    Science.gov (United States)

    Zahn, Daniel; Frömel, Tobias; Knepper, Thomas P

    2016-09-15

    Mobile and persistent organic micropollutants may impact raw and drinking waters and are thus of concern for human health. To identify such possible substances of concern nineteen water samples from five European countries (France, Switzerland, The Netherlands, Spain and Germany) and different compartments of the water cycle (urban effluent, surface water, ground water and drinking water) were enriched with mixed-mode solid phase extraction. Hydrophilic interaction liquid chromatography - high resolution mass spectrometry non-target screening of these samples led to the detection and structural elucidation of seven novel organic micropollutants. One structure could already be confirmed by a reference standard (trifluoromethanesulfonic acid) and six were tentatively identified based on experimental evidence (chloromethanesulfonic acid, dichloromethanesulfonic acid, trichloromethanesulfonic acid, bromomethanesulfonic acid, dibromomethanesulfonic acid and bromochloromethanesulfonic acid). Approximated concentrations for these substances show that trifluoromethanesulfonic acid, a chemical registered under the European Union regulation REACH with a production volume of more than 100 t/a, is able to spread along the water cycle and may be present in concentrations up to the μg/L range. Chlorinated and brominated methanesulfonic acids were predominantly detected together which indicates a common source and first experimental evidence points towards water disinfection as a potential origin. Halogenated methanesulfonic acids were detected in drinking waters and thus may be new substances of concern. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Quantitative Prediction of Solvation Free Energy in Octanol of Organic Compounds

    Directory of Open Access Journals (Sweden)

    Eduardo J. Delgado

    2009-03-01

    Full Text Available The free energy of solvation, ΔGS0 , in octanol of organic compunds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a ΔGS0 range from about –50 to 0 kJ·mol-1. The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ·mol-1, just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

  5. Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

    Energy Technology Data Exchange (ETDEWEB)

    Ren Guofa, E-mail: rgf2008@shu.edu.cn [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Zhao, Wang [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Zhiqiang, Yu [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang, Wang [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Shengtao, Ma [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Minghong, Wu [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Guoying, Sheng [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Jiamo, Fu [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2013-01-15

    Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40-39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: Black-Right-Pointing-Pointer DP was reported in fish samples from river close to an old industrial base in China. Black-Right-Pointing-Pointer The first report on the unusually high fraction of PCB-209 in samples from China. Black-Right-Pointing-Pointer GC Multiplication-Sign GC-TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

  6. Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

    International Nuclear Information System (INIS)

    Ren Guofa; Wang Zhao; Yu Zhiqiang; Wang Yang; Ma Shengtao; Wu Minghong; Sheng Guoying; Fu Jiamo

    2013-01-01

    Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40–39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: ► DP was reported in fish samples from river close to an old industrial base in China. ► The first report on the unusually high fraction of PCB-209 in samples from China. ► GC × GC–TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

  7. Environmental health sciences center task force review on halogenated organics in drinking water.

    Science.gov (United States)

    Deinzer, M; Schaumburg, F; Klein, E

    1978-06-01

    The disinfection of drinking water by chlorination has in recent years come under closer scrutiny because of the potential hazards associated with the production of stable chlorinated organic chemicals. Organic chemical contaminants are common to all water supplies and it is now well-established that chlorinated by-products are obtained under conditions of disinfection, or during tertiary treatment of sewage whose products can ultimately find their way into drinking water supplies. Naturally occurring humic substances which are invariably present in drinking waters are probably the source of chloroform and other halogenated methanes, and chloroform has shown up in every water supply investigated thus far.The Environmental Protection Agency is charged with the responsibility of assessing the public health effects resulting from the consumption of contaminated drinking water. It has specifically undertaken the task of determining whether organic contaminants or their chlorinated derivatives have a special impact, and if so, what alternatives there are to protect the consumer against bacterial and viral diseases that are transmitted through infected drinking waters. The impetus to look at these chemicals is not entirely without some prima facie evidence of potential trouble. Epidemiological studies suggested a higher incidence of cancer along the lower Mississippi River where the contamination from organic chemicals is particularly high. The conclusions from these studies have, to be sure, not gone unchallenged.The task of assessing the effects of chemicals in the drinking water is a difficult one. It includes many variables, including differences in water supplies and the temporal relationship between contamination and consumption of the finished product. It must also take into account the relative importance of the effects from these chemicals in comparison to those from occupational exposure, ingestion of contaminated foods, inhalation of polluted air, and many

  8. Genetic effects of organic mercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramel, C

    1967-01-01

    Studies on the genetic and developmental effects of organic mercury compounds on lilies, drosophila, and ice were carried out. It was found that chromosomal and developmental abnormalities were correlated with the administration of mercury compounds.

  9. Enzymatic Halogenation and Dehalogenation Reactions: Pervasive and Mechanistically Diverse.

    Science.gov (United States)

    Agarwal, Vinayak; Miles, Zachary D; Winter, Jaclyn M; Eustáquio, Alessandra S; El Gamal, Abrahim A; Moore, Bradley S

    2017-04-26

    Naturally produced halogenated compounds are ubiquitous across all domains of life where they perform a multitude of biological functions and adopt a diversity of chemical structures. Accordingly, a diverse collection of enzyme catalysts to install and remove halogens from organic scaffolds has evolved in nature. Accounting for the different chemical properties of the four halogen atoms (fluorine, chlorine, bromine, and iodine) and the diversity and chemical reactivity of their organic substrates, enzymes performing biosynthetic and degradative halogenation chemistry utilize numerous mechanistic strategies involving oxidation, reduction, and substitution. Biosynthetic halogenation reactions range from simple aromatic substitutions to stereoselective C-H functionalizations on remote carbon centers and can initiate the formation of simple to complex ring structures. Dehalogenating enzymes, on the other hand, are best known for removing halogen atoms from man-made organohalogens, yet also function naturally, albeit rarely, in metabolic pathways. This review details the scope and mechanism of nature's halogenation and dehalogenation enzymatic strategies, highlights gaps in our understanding, and posits where new advances in the field might arise in the near future.

  10. Xenobiotic organic compounds in wastewater

    DEFF Research Database (Denmark)

    Eriksson, Eva; Baun, Anders; Henze, Mogens

    2002-01-01

    hundred of XOCs, among them mainly originating from hygiene products: chlorophenols, detergents and phthalates. Several compounds not deriving from hygiene products were also identified e.g. flame-retardants and drugs. A environmental hazard identification showed that a large number of compounds with high...

  11. using stereochemistry models in teaching organic compounds

    African Journals Online (AJOL)

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    The purpose of the study was to find out the effect of stereochemistry models on students' ... consistent with the names given to organic compounds. Some of ... Considering class level, what is the performance of the students in naming organic.

  12. Passive sampling as a tool for identifying micro-organic compounds in groundwater.

    Science.gov (United States)

    Mali, N; Cerar, S; Koroša, A; Auersperger, P

    2017-09-01

    The paper presents the use of a simple and cost efficient passive sampling device with integrated active carbon with which to test the possibility of determining the presence of micro-organic compounds (MOs) in groundwater and identifying the potential source of pollution as well as the seasonal variability of contamination. Advantage of the passive sampler is to cover a long sampling period by integrating the pollutant concentration over time, and the consequently analytical costs over the monitoring period can be reduced substantially. Passive samplers were installed in 15 boreholes in the Maribor City area in Slovenia, with two sampling campaigns covered a period about one year. At all sampling sites in the first series a total of 103 compounds were detected, and 144 in the second series. Of all detected compounds the 53 most frequently detected were selected for further analysis. These were classified into eight groups based on the type of their source: Pesticides, Halogenated solvents, Non-halogenated solvents, Domestic and personal, Plasticizers and additives, Other industrial, Sterols and Natural compounds. The most frequently detected MO compounds in groundwater were tetrachloroethene and trichloroethene from the Halogenated solvents group. The most frequently detected among the compound's groups were pesticides. Analysis of frequency also showed significant differences between the two sampling series, with less frequent detections in the summer series. For the analysis to determine the origin of contamination three groups of compounds were determined according to type of use: agriculture, urban and industry. Frequency of detection indicates mixed land use in the recharge areas of sampling sites, which makes it difficult to specify the dominant origin of the compound. Passive sampling has proved to be useful tool with which to identify MOs in groundwater and for assessing groundwater quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Experimental and computational evidence of halogen bonds involving astatine

    Science.gov (United States)

    Guo, Ning; Maurice, Rémi; Teze, David; Graton, Jérôme; Champion, Julie; Montavon, Gilles; Galland, Nicolas

    2018-03-01

    The importance of halogen bonds—highly directional interactions between an electron-deficient σ-hole moiety in a halogenated compound and an acceptor such as a Lewis base—is being increasingly recognized in a wide variety of fields from biomedicinal chemistry to materials science. The heaviest halogens are known to form stronger halogen bonds, implying that if this trend continues down the periodic table, astatine should exhibit the highest halogen-bond donating ability. This may be mitigated, however, by the relativistic effects undergone by heavy elements, as illustrated by the metallic character of astatine. Here, the occurrence of halogen-bonding interactions involving astatine is experimentally evidenced. The complexation constants of astatine monoiodide with a series of organic ligands in cyclohexane solution were derived from distribution coefficient measurements and supported by relativistic quantum mechanical calculations. Taken together, the results show that astatine indeed behaves as a halogen-bond donor—a stronger one than iodine—owing to its much more electrophilic σ-hole.

  14. Simulation of the adsorption capacity of polar organic compounds and dyes from water onto activated carbons: Model development and validation

    Directory of Open Access Journals (Sweden)

    Warisa Bunmahotama

    2018-03-01

    Full Text Available A model approach is developed to simulate the adsorption isotherms of low-molecular-weight polar organic compounds (LMWPOCs, halogenated LMWPOCs, and dye molecules onto activated carbons (AC. The models were based on the Dubinin–Astakhov equation, with the limiting pore volume of adsorbent estimated from the pore size distribution data, and the adsorption affinity of the adsorbate described by the molecular connectivity index. The models were used to simulate the adsorption data of 87 LMWPOCs onto six ACs, 25 halogenated LMWPOCs onto two ACs and 22 dyes onto three ACs. The developed models follow the experimental data fairly well, with errors of 49, 33 and 43% for the tested LMWPOCs, halogenated LMWPOCs, and dyes, respectively. This study shows that the developed model approach may provide a simple means for the estimation of adsorption capacity for LMWPOCs and dyes onto ACs in water.

  15. Halogenated arsenenes as Dirac materials

    International Nuclear Information System (INIS)

    Tang, Wencheng; Sun, Minglei; Ren, Qingqiang; Wang, Sake; Yu, Jin

    2016-01-01

    Highlights: • We have revealed the presence of Dirac cone in fully-halogenated arsenene compounds. • All fully-halogenated arsenene except As_2I_2 would spontaneously form and stable in defending the thermal fluctuation in room temperature. - Abstract: Arsenene is the graphene-like arsenic nanosheet, which has been predicted very recently [S. Zhang, Z. Yan, Y. Li, Z. Chen, and H. Zeng, Angewandte Chemie, 127 (2015) 3155–3158]. Using first-principles calculations, we systematically investigate the structures and electronic properties of fully-halogenated arsenenes. Formation energy analysis reveals that all the fully-halogenated arsenenes except iodinated arsenene are energetically favorable and could be synthesized. We have revealed the presence of Dirac cone in fully-halogenated arsenene compounds. They may have great potential applications in next generation of high-performance devices.

  16. Alkylation of organic aromatic compounds

    Science.gov (United States)

    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.

  17. Alkylation of organic aromatic compounds

    Science.gov (United States)

    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.

  18. Low molecular weight halogenated hydrocarbons (LMHHs) in Mediterranean sea water: Preliminary observations

    International Nuclear Information System (INIS)

    Elder, D.L.; Villeneuve, J.P.; Harvey, G.R.

    1976-01-01

    Halogenated organic compounds containing 1-3 carbon atoms are among the most extensively produced synthetic chemicals. Within this group of compounds are solvents such as chloroform, carbon tetrachloride, trichloroethane and the chlorofluoro carbons or freons which are used as refrigerants and aerosol sprays. Once produced many of these compounds are eventually released to the environment

  19. ESR studies of Bunsen-type methane-air flames. II. The effects of the addition of halogenated compounds to the secondary air on the hydrogen atoms in the flame

    Energy Technology Data Exchange (ETDEWEB)

    Noda, S; Fujimoto, S; Claesson, O; Yoshida, H

    1983-09-01

    Hydrogen atoms in a methane-air Bunsen-type flame were detected by the flame-in-cavity ESR method. The addition of a halogenated compound to the secondary air reduced the H-atom concentration linearly with an increase in additive concentration. These 8 halogenated compounds examined showed increased effectiveness in scavenging H atoms in this order: hydrochloric acid < dichlorodifluoromethane < chloroform < methyl chloride < methylene chloride < trichlorofluoromethane < carbon tetrachlorie < methyl bromide. The chemical effects of these additives on the combustion reactions agree well with the inhibitor indices for these compounds. 14 references, 3 figures.

  20. Organic electronic devices using phthalimide compounds

    Science.gov (United States)

    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.

  1. INVESTIGATION OF THE TOTAL ORGANIC HALOGEN ANALYTICAL METHOD AT THE WASTE SAMPLING CHARACTERIZATION FACILITY (WSCF)

    International Nuclear Information System (INIS)

    DOUGLAS JG; MEZNARICH HD, PHD; OLSEN JR; ROSS GA; STAUFFER M

    2008-01-01

    Total organic halogen (TOX) is used as a parameter to screen groundwater samples at the Hanford Site. Trending is done for each groundwater well, and changes in TOX and other screening parameters can lead to costly changes in the monitoring protocol. The Waste Sampling and Characterization Facility (WSCF) analyzes groundwater samples for TOX using the United States Environmental Protection Agency (EPA) SW-846 method 9020B (EPA 1996a). Samples from the Soil and Groundwater Remediation Project (S and GRP) are submitted to the WSCF for analysis without information regarding the source of the sample; each sample is in essence a 'blind' sample to the laboratory. Feedback from the S and GRP indicated that some of the WSCF-generated TOX data from groundwater wells had a number of outlier values based on the historical trends (Anastos 2008a). Additionally, analysts at WSCF observed inconsistent TOX results among field sample replicates. Therefore, the WSCF lab performed an investigation of the TOX analysis to determine the cause of the outlier data points. Two causes were found that contributed to generating out-of-trend TOX data: (1) The presence of inorganic chloride in the groundwater samples: at inorganic chloride concentrations greater than about 10 parts per million (ppm), apparent TOX values increase with increasing chloride concentration. A parallel observation is the increase in apparent breakthrough of TOX from the first to the second activated-carbon adsorption tubes with increasing inorganic chloride concentration. (2) During the sample preparation step, excessive purging of the adsorption tubes with oxygen pressurization gas after sample loading may cause channeling in the activated-carbon bed. This channeling leads to poor removal of inorganic chloride during the subsequent wash step with aqueous potassium nitrate. The presence of this residual inorganic chloride then produces erroneously high TOX values. Changes in sample preparation were studied to more

  2. Genetic effects of organic mercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramel, C

    1967-01-01

    Organic mercury compounds have a c-mitotic effect on plant cells that cause polyploidi. Studies were performed on Allium root cells. These investigations involved methyl mercury dicyandiamide, methyl mercury hydroxide, and phenyl mercury hydroxide. The lowest concentration necessary for a cytologically observable effect was about 0.05 ppM Hg for the methyl compounds. For the phenyl compound, the value was lower. Experiments were performed on Drosophila melanogaster. The question was whether the mercury would reach the gonads. Experimental data with mercury treated larvae indicated a chromosome disjunction. Data indicated a preferential segregation at the meiotic division might be involved. Experiments are being performed on mice inbred (CBA) in order to investigate teratogenic effects and dominant lethality caused by organic mercury compounds. The mutagenic effects of these compounds are studied on Neurospora Drosophila. No conclusive data is now available.

  3. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    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.

  4. Air sparging of organic compounds in groundwater

    International Nuclear Information System (INIS)

    Hicks, P.M.

    1994-01-01

    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

  5. Methane oxidation and degradation of organic compounds in landfill soil covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2002-01-01

    High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero-order kin......High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero...

  6. Organic compounds in the Murchison meteorite.

    Science.gov (United States)

    Ponnamperuma, C.

    1972-01-01

    Impressive supporting evidence for the concept of the chemical evolution of life has appeared in the discovery of biologically important compounds in extraterrestrial samples. The approaches pursued to detect extraterrestrial organic compounds include the study of interstellar space by radioastronomy, the evaluation of the Apollo lunar samples, and the analysis of meteorites, both ancient and recent. It has been found that the clouds of gas in the interstellar medium contain a wide variety of molecules, most of which are organic in nature. The carbonaceous chondrites contain polymeric organic matter. Amino acids have been detected in the Murchison meteorite.

  7. INVESTIGATION OF THE TOTAL ORGANIC HALOGEN ANALYTICAL METHOD AT THE WASTE SAMPLING AND CHARACTERIZATION FACILITY

    International Nuclear Information System (INIS)

    Douglas, J.G.; Meznarich, H.K.; Olsen, J.R.; Ross, G.A.; Stauffer, M.

    2009-01-01

    Total organic halogen (TOX) is used as a parameter to screen groundwater samples at the Hanford Site. Trending is done for each groundwater well, and changes in TOX and other screening parameters can lead to costly changes in the monitoring protocol. The Waste Sampling and Characterization Facility (WSCF) analyzes groundwater samples for TOX using the United States Environmental Protection Agency (EPA) SW-S46 method 9020B (EPA 1996a). Samples from the Soil and Groundwater Remediation Project (SGRP) are submitted to the WSCF for analysis without information regarding the source of the sample; each sample is in essence a ''blind'' sample to the laboratory. Feedback from the SGRP indicated that some of the WSCF-generated TOX data from groundwater wells had a number of outlier values based on the historical trends (Anastos 200Sa). Additionally, analysts at WSCF observed inconsistent TOX results among field sample replicates. Therefore, the WSCF lab performed an investigation of the TOX analysis to determine the cause of the outlier data points. Two causes were found that contributed to generating out-of-trend TOX data: (1) The presence of inorganic chloride in the groundwater samples: at inorganic chloride concentrations greater than about 10 parts per million (ppm), apparent TOX values increase with increasing chloride concentration. A parallel observation is the increase in apparent breakthrough of TOX from the first to the second activated-carbon adsorption tubes with increasing inorganic chloride concentration. (2) During the sample preparation step, excessive purging of the adsorption tubes with oxygen pressurization gas after sample loading may cause channeling in the activated carbon bed. This channeling leads to poor removal of inorganic chloride during the subsequent wash step with aqueous potassium nitrate. The presence of this residual inorganic chloride then produces erroneously high TOX values. Changes in sample preparation were studied to more effectively

  8. Reflectance spectroscopy of organic compounds: 1. Alkanes

    Science.gov (United States)

    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.

  9. Integrated modelling of two xenobiotic organic compounds

    DEFF Research Database (Denmark)

    Lindblom, Erik Ulfson; Gernaey, K.V.; Henze, Mogens

    2006-01-01

    This paper presents a dynamic mathematical model that describes the fate and transport of two selected xenobiotic organic compounds (XOCs) in a simplified representation. of an integrated urban wastewater system. A simulation study, where the xenobiotics bisphenol A and pyrene are used as reference...... compounds, is carried out. Sorption and specific biological degradation processes are integrated with standardised water process models to model the fate of both compounds. Simulated mass flows of the two compounds during one dry weather day and one wet weather day are compared for realistic influent flow...... rate and concentration profiles. The wet weather day induces resuspension of stored sediments, which increases the pollutant load on the downstream system. The potential of the model to elucidate important phenomena related to origin and fate of the model compounds is demonstrated....

  10. Performance audits and laboratory comparisons for SCOS97-NARSTO measurements of speciated volatile organic compounds

    Science.gov (United States)

    Fujita, Eric M.; Harshfield, Gregory; Sheetz, Laurence

    Performance audits and laboratory comparisons were conducted as part of the quality assurance program for the 1997 Southern California Ozone Study (SCOS97-NARSTO) to document potential measurement biases among laboratories measuring speciated nonmethane hydrocarbons (NMHC), carbonyl compounds, halogenated compounds, and biogenic hydrocarbons. The results show that measurements of volatile organic compounds (VOC) made during SCOS97-NARSTO are generally consistent with specified data quality objectives. The hydrocarbon comparison involved nine laboratories and consisted of two sets of collocated ambient samples. The coefficients of variation among laboratories for the sum of the 55 PAM target compounds and total NMHC ranged from ±5 to 15 percent for ambient samples from Los Angeles and Azusa. Abundant hydrocarbons are consistently identified by all laboratories, but discrepancies occur for olefins greater than C 4 and for hydrocarbons greater than C 8. Laboratory comparisons for halogenated compounds and biogenic hydrocarbons consisted of both concurrent ambient sampling by different laboratories and round-robin analysis of ambient samples. The coefficients of variation among participating laboratories were about 10-20 percent. Performance audits were conducted for measurement of carbonyl compounds involving sampling from a standard mixture of carbonyl compounds. The values reported by most of the laboratories were within 10-20 percent of those of the reference laboratory. Results of field measurement comparisons showed larger variations among the laboratories ranging from 20 to 40 percent for C 1-C 3 carbonyl compounds. The greater variations observed in the field measurement comparison may reflect potential sampling artifacts, which the performance audits did not address.

  11. Modern and historical fluxes of halogenated organic contaminants to a lake in the Canadian arctic, as determined from annually laminated sediment cores

    International Nuclear Information System (INIS)

    Stern, G.A.; Braekevelt, E.; Helm, P.A.; Bidleman, T.F.; Outridge, P.M.; Lockhart, W.L.; McNeeley, R.; Rosenberg, B.; Ikonomou, M.G.; Hamilton, P.; Tomy, G.T.; Wilkinson, P.

    2005-01-01

    Two annually laminated cores collected from Lake DV09 on Devon Island in May 1999 were dated using 210 Pb and 137 Cs, and analyzed for a variety of halogenated organic contaminants (HOCs), including polychlorinated biphenyls (PCBs), organochlorine pesticides, short-chain polychlorinated n-alkanes (sPCAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs). Dry weight HOC concentrations in Lake DV09 sediments were generally similar to other remote Arctic lakes. Maximum HOC fluxes often agreed well with production maxima, although many compound groups exhibited maxima at or near the sediment surface, much later than peak production. The lower than expected HOC concentrations in older sediment slices may be due to anaerobic degradation and possibly to dilution resulting from a temporary increase in sedimentation rate observed between the mid-1960s and 1970s. Indeed, temporal trends were more readily apparent for those compound classes when anaerobic metabolites were also analyzed, such as for DDT and toxaphene. However, it is postulated here for the first time that the maximum or increasing HOC surface fluxes observed for many of the major compound classes in DV09 sediments may be influenced by climate variation and the resulting increase in algal primary productivity which could drive an increasing rate of HOC scavenging from the water column. Both the fraction (F TC ) and enantiomer fraction (EF) of trans-chlordane (TC) decreased significantly between 1957 and 1997, suggesting that recent inputs to the lake are from weathered chlordane sources. PCDD/Fs showed a change in sources from pentachlorophenol (PeCP) in the 1950s and 1960s to combustion sources into the 1990s. Improvements in combustion technology may be responsible for the reducing the proportion of TCDF relative to OCDD in the most recent slice

  12. Behaviour of organic sulfur compounds in HPLC

    International Nuclear Information System (INIS)

    Freyholdt, T.

    1982-01-01

    The retention behaviour of organic sulfur compounds in the reverse-bonded-phase chromatography is characterized by determining the retention indices according to Kovats. The results of these studies show that the solubility of organic compounds in the eluting agent and the molar sorption surfaces of the solutes are the main factors determining the retention behaviour. Knowledge of the retention indices of above-mentioned compounds allows a quick interpretation of chromatograms obtained through a product analysis of γ-irradiated aqueous solutions of organic sulfur compounds. Dithia compounds of the type CH 3 -S-(CH 2 )sub(n)-S-Ch 3 (1 1. 2,4-Dithiapentane (n = 1) however will yield primarily monothio-S-methyl formate as a stable end product. The formation of oxygenic reaction products proceeds via sulfur-centred radical kations. Spin trapping experiments with nitroxyl radicals show that it is possible to trap radiation-chemically produced radicals of sulfurous substrates, but the thus obtained adducts with half-life periods of 4-5 min. cannot be identified by means of NMR, IR or mass spectroscopy. (orig.) [de

  13. Biosynthesis of polybrominated aromatic organic compounds by marine bacteria

    Science.gov (United States)

    Agarwal, Vinayak; El Gamal, Abrahim A.; Yamanaka, Kazuya; Poth, Dennis; Kersten, Roland D.; Schorn, Michelle; Allen, Eric E.; Moore, Bradley S.

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) and polybrominated bipyrroles are natural products that bioaccumulate in the marine food chain. PBDEs have attracted widespread attention due to their persistence in the environment and potential toxicity to humans. However, the natural origins of PBDE biosynthesis are not known. Here we report marine bacteria as producers of PBDEs and establish a genetic and molecular foundation for their production that unifies paradigms for the elaboration of bromophenols and bromopyrroles abundant in marine biota. We provide biochemical evidence of marine brominase enzymes revealing decarboxylative-halogenation enzymology previously unknown among halogenating enzymes. Biosynthetic motifs discovered in our study were used to mine sequence databases to discover unrealized marine bacterial producers of organobromine compounds. PMID:24974229

  14. Semivolatile organic compounds in indoor environments

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Nazaroff, W.W.

    2008-01-01

    Semivolatile organic compounds (SVOCs) are ubiquitous in indoor environments, redistributing from their original sources to all indoor surfaces. Exposures resulting from their indoor presence contribute to detectable body burdens of diverse SVOCs, including pesticides, plasticizers, and flame ret...... remarkably well with levels measured in dermal hand wipes for SVOCs possessing a wide range of octanol-air partition coefficients....

  15. Organic chemistry

    International Nuclear Information System (INIS)

    2003-08-01

    This book with sixteen chapter explains organic chemistry on linkage isomerism such as alkane, cycloalkane, alkene, aromatic compounds, stereo selective isomerization, aromatic compounds, stereo selective isomerization, organic compounds, stereo selective isomerization, organic halogen compound, alcohol, ether, aldehyde and ketone, carboxylic acid, dicarboxylic acid, fat and detergent, amino, carbohydrate, amino acid and protein, nucleotide and nucleic acid and spectroscopy, a polymer and medical chemistry. Each chapter has introduction structure and characteristic and using of organic chemistry.

  16. Chemical cleaning-associated generation of dissolved organic matter and halogenated byproducts in ceramic MBR: Ozone versus hypochlorite.

    Science.gov (United States)

    Sun, Huifang; Liu, Hang; Han, Jiarui; Zhang, Xiangru; Cheng, Fangqin; Liu, Yu

    2018-04-24

    This study characterized the dissolved organic matter (DOM) and byproducts generated after the exposure of activated sludge to ozone and NaClO in ceramic MBR. It was found that NaClO triggered more significant release of DOM than ozone. Proteins with the molecular weight greater than 20 kDa and humic acid like-substances were the principal components of DOM generated by NaClO, while ozone was found to effectively degrade larger biopolymers to low molecular weight substances. The results showed that more than 80% of DOM generated by NaClO and ozone could pass through the 0.2-μm ceramic membrane. Furthermore, total organic chlorine (TOCl) was determined to be the principal species of halogenated byproducts in both cases, while the generation of TOCl by NaClO was much more significant than that by ozone. Only a small fraction of TOCl was removed by the 0.2-μm ceramic membrane. More importantly, the toxic bioassays further revealed that the supernatant of sludge suspension and permeate in the MBR with NaClO cleaning exhibited higher developmental toxicity to the polychaete embryos than those by ozone. The results clearly showed that on-line chemical cleaning with ozone should be a more eco-friendly and safer approach for sustaining long-term membrane permeability in ceramic MBR. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Influences of binding to dissolved organic matter on hydrophobic organic compounds in a multi-contaminant system: Coefficients, mechanisms and ecological risks

    International Nuclear Information System (INIS)

    Li, Yi-Long; He, Wei; Liu, Wen-Xiu; Kong, Xiang-Zhen; Yang, Bin; Yang, Chen; Xu, Fu-Liu

    2015-01-01

    The complexation flocculation (CF) method was successfully employed to identify binding coefficients (K_d_o_c) of specific organic contaminants to dissolved organic matter (DOM, often indicated by dissolved organic carbon, DOC) in a multi-contaminant hydrophobic organic contaminant (HOC) system. K_d_o_c values were obtained for most of the evaluated 33 HOCs, indicating the feasibility and applicability of the CF method in a multi-contaminant system. Significant positive correlations were observed between binding coefficients and octanol–water partition coefficients (K_o_w) for organic halogen compounds, such as polybrominated diphenyl ethers (PBDEs) (R"2 = 0.95, p < 0.05) and organic chlorine pesticides (OCPs) (methoxychlor excluded, R"2 = 0.82, p < 0.05). The positive correlations identified between the lgK_d_o_c and lgBCF (bioconcentration factor) for PBDEs and OCPs, as well as the negative correlation observed for polycyclic aromatic hydrocarbons (PAHs), indicated that different binding or partition mechanisms between PAHs and organic halogen compounds exist. These differences further result in discriminative competition partitions of HOCs between DOM and organisms. Assuming that only freely dissolved HOCs are bioconcentrative, the results of DOM-influenced bioconcentration factor (BCF_D_O_M) and DOM-influenced lowest observed effect level (LOEL_D_O_M) indicate that the ecological risk of HOCs is decreased by DOM. - Highlights: • Complexing-flocculation is viable in measuring K_d_o_c in a multi-polluted system. • The binding mechanisms between PAHs and organic halogens were different. • DOM should be considered when assessing ecological risk of HOCs in natural ecosystem. - Assuming only freely dissolved HOCs are effective, bioconcentration factors and ecological risks of HOCs are decreased by dissolved organic matter via binding.

  18. Participation of the Halogens in Photochemical Reactions in Natural and Treated Waters

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2017-10-01

    Full Text Available Halide ions are ubiquitous in natural waters and wastewaters. Halogens play an important and complex role in environmental photochemical processes and in reactions taking place during photochemical water treatment. While inert to solar wavelengths, halides can be converted into radical and non-radical reactive halogen species (RHS by sensitized photolysis and by reactions with secondary reactive oxygen species (ROS produced through sunlight-initiated reactions in water and atmospheric aerosols, such as hydroxyl radical, ozone, and nitrate radical. In photochemical advanced oxidation processes for water treatment, RHS can be generated by UV photolysis and by reactions of halides with hydroxyl radicals, sulfate radicals, ozone, and other ROS. RHS are reactive toward organic compounds, and some reactions lead to incorporation of halogen into byproducts. Recent studies indicate that halides, or the RHS derived from them, affect the concentrations of photogenerated reactive oxygen species (ROS and other reactive species; influence the photobleaching of dissolved natural organic matter (DOM; alter the rates and products of pollutant transformations; lead to covalent incorporation of halogen into small natural molecules, DOM, and pollutants; and give rise to certain halogen oxides of concern as water contaminants. The complex and colorful chemistry of halogen in waters will be summarized in detail and the implications of this chemistry for global biogeochemical cycling of halogen, contaminant fate in natural waters, and water purification technologies will be discussed.

  19. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao; Croue, Jean-Philippe

    2015-01-01

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  20. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao

    2015-12-02

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  1. Process for removal of hydrogen halides or halogens from incinerator gas

    Science.gov (United States)

    Huang, H.S.; Sather, N.F.

    1987-08-21

    A process for reducing the amount of halogens and halogen acids in high temperature combustion gas and through their removal, the formation of halogenated organics at lower temperatures, with the reduction being carried out electrochemically by contacting the combustion gas with the negative electrode of an electrochemical cell and with the halogen and/or halogen acid being recovered at the positive electrode.

  2. Degradation of air polluted by organic compounds

    International Nuclear Information System (INIS)

    Santoyo O, E.L.; Lizama S, B.E.; Vazquez A, O.; Luna C, P.C.; Arredondo H, S.

    1999-01-01

    According to the Mexican standard NOM-010-STPS-1994 it has been established concentrations of maximum permissible levels in workable air for styrene in the range 420-1710 mg/m 3 and for xylene between 218-870 mg/m 3 . In this work it is studied a biological treatment (bio filtration) for air polluted by xylene and styrene where the microorganisms are adhered at synthetic fiber, these degrade to the organic compounds that across in gaseous state and they are mineralized toward CO 2 and H 2 O. The characteristics of temperature, p H, concentration of organic compound and mineral parameters, as well as, the biomass quantity have been optimized for that bio filters efficiency were greater than those reported in other works. (Author)

  3. Oxo-halogen complexes of molybdenum (V) with bioactive polyfunctional organic ligands

    International Nuclear Information System (INIS)

    Azizkulova, O.A.

    1997-01-01

    The present work dedicated to systematization of synthesized by author coordinated compounds of molybdenum with aminoacetic, asparaginic, glutamic, n-aminobenzoic acids, 1-methyl-2-imidazole, thio-semi-carbazone, thia-dia-zole and its derivatives each of which has from 2 till 5 potentially donor atom

  4. Efficient Annealing-Free P3HT:PC_6_1BM-Based Organic Solar Cells by Using a Novel Solvent Additive without a Halogen or Sulphur Atom

    International Nuclear Information System (INIS)

    Xiao Man-Jun; Zhu Wei-Guo; Shen Wen-Fei; Wang Jun-Yi; Han Liang-Liang; Chen Wei-Chao; Bao Xi-Chang; Yang Ren-Qiang

    2015-01-01

    The power conversion efficiency (PCE) of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PC_6_1BM) based organic solar cells (OSCs) is significantly improved by using benzyl acetate (BA), an organic compound without any halogen or sulphur atom, as a processing additive to control the blend morphology. The solar cells show PCE of 3.85% with a fill factor (FF) of 65.22%, which are higher than those of the common thermal annealing device (PCE 3.30%, FF 60.83%). The overall increased PCE depends upon the enhanced crystallinity of P3HT and good carriers transport, with a high balanced charge carrier mobility. (cross-disciplinary physics and related areas of science and technology)

  5. Iron Mineral Catalyzed C-H Activation As a Potential Pathway for Halogenation Processes

    Science.gov (United States)

    Tubbesing, C.; Schoeler, H. F.; Benzing, K.; Krause, T.; Lippe, S.; Rudloff, M.

    2014-12-01

    Due to increasing drinking water demand of mankind and an expected climate change the impact of salt lakes and salt deserts will increase within the next decades. Furthermore, a rising sea level influences coastal areas like salt marshes and abets processes which will lead to elevated organohalogen formation. An additional increase of the global warming potential, of particle formation and stratospheric ozone depletion is expected. Understanding these multifaceted processes is essential for mankind to be prepared for these alterations of the atmosphere. For example, Keppler et al. (2000) described the production of volatile halogenated organic compounds via oxidation of organic matter driven by ferric iron. However, the formation of long-chained alkyl halides in salt lakes is yet undisclosed. Despite the relative "inertness" of alkanes a direct halogenation of these compounds might be envisaged. In 2005 Vaillancourt et al. discovered a nonheme iron enzyme which is able to halogenate organic compounds via generating the high valent ferryl cation as reaction center. Based on various publications about C-H activation (Bergman, 2007) we postulate a halogenation process in which an iron containing minerals catalyse the C-H bond cleavage of organic compounds in soils. The generated organic radicals are highly reactive towards halides connected to the iron complex. We suggest that next to diagenetically altered iron containing enzymes, minerals such as oxides, hydroxides and sulfides are involved in abiotic halogenation processes. We applied the amino acid methionine as organic model compound and soluble iron species as reactants. All samples were incubated in aqueous phases containing various NaCl concentrations. As a result various halogenated ethanes and ethenes were identified as reaction products. References Bergman, R. G. (2007) Nature, 446(7134) 391-393 Keppler, F., et al. (2000) Nature, 403(6767) 298-301 Vaillancourt, F. H., et al. (2005) Nature, 436(7054) 1191-1194

  6. Typical halogenated persistent organic pollutants in indoor dust and the associations with childhood asthma in Shanghai, China.

    Science.gov (United States)

    Meng, Ge; Nie, Zhiqing; Feng, Yan; Wu, Xiaomeng; Yin, Yong; Wang, Yan

    2016-04-01

    Halogenated persistent organic pollutants (Hal-POPs) are significant contaminants in the indoor environment that are related to many human diseases. Ingestion of indoor dust is considered the major pathway of Hal-POP exposures, especially for children aged 3-6 years. Alongside a retrospective study on the associations between typical Hal-POP exposure and childhood asthma in Shanghai, indoor dust samples from asthmatic and non-asthmatic children's homes (n = 60, each) were collected. Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured by GC-MS. BDE-209, PCB-8 and p,p'-DDE were the predominant components in each chemical category. The concentrations of most Hal-POPs were significantly higher in the asthmatic families. The associations between Hal-POP exposure and asthma occurrence were examined by calculating the odds ratios (ORs) using a logistic regression model. A positive association was found between p,p'-DDE in indoor dust and childhood asthma (OR = 1.825, 95%CI: 1.004, 3.317; p = 0.048). The average daily doses of Hal-POP intake were calculated using the method provided by the USEPA. Non-carcinogenic health risks were preliminarily assessed. Our study indicated that exposure to p,p'-DDE via indoor dust may contribute to childhood asthma occurrence. Non-carcinogenic health risks were not found with the intake of Hal-POPs via the ingestion of indoor dust. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Exposure to volatile organic compounds: Comparison among different transportation modes

    Science.gov (United States)

    Do, Duc Hoai; Van Langenhove, Herman; Chigbo, Stephen Izuchukwu; Amare, Abebech Nuguse; Demeestere, Kristof; Walgraeve, Christophe

    2014-09-01

    The increasing trend of promoting public transportation (bus tram, metro, train) and more environmental friendly and sustainable non fossil-fuel alternatives (walking, cycling etc) as substitutes for auto vehicles brings forward new questions with regard to pollutant levels to which commuters are exposed. In this study, three transportation modes (tram, auto vehicle and bicycle) are studied and concentration levels of 84 volatile organic compounds (VOCs) (hydrocarbons, aromatic hydrocarbons, oxygen containing hydrocarbons, terpenes and halogenated compounds) are measured along a route in the city of Ghent, Belgium. The concentration levels are obtained by active sampling on Tenax TA sorbent tubes followed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) using deuterated toluene as an internal standard. The median total VOC concentrations for the tram mode (33 μg/m³) is 1.7 times higher than that of the bicycle mode (20 μg/m³) and 1.5 times higher than for the car mode (22 μg/m³). It is found that aromatic hydrocarbons account for a significant proportion in the total VOCs concentration (TVOCs) being as high as 41-57%, 59-72% and 58-72% for the tram, car and bicycle respectively. In all transportation modes, there was a high (r > 0.6) degree of correlation between BTEX compounds, isopropylbenzene, n-propylbenzene, 1,3,5-trimethylbenzene and 1,2,4-trimethylbenzene. When comparing time weighed average concentrations along a fixed route in Ghent, it is found that commuters using the tram mode experience the highest TVOCs concentration levels. However, next to the concentration level to which commuters are exposed, the physical activity level involving the mode of transportation is important to assess the exposure to toxic VOCs. It is proven that the commuter using a bicycle (4.3 ± 1.5 μg) inhales seven and nine times more benzene compared to the commuter using the car and tram respectively, when the same route is followed.

  8. Halogenated organic contaminants (HOCs) in sediment from a highly eutrophicated lake, China: occurrence, distribution and mass inventories.

    Science.gov (United States)

    Wang, Ji-Zhong; Liu, Liang-Ying; Zhang, Kai; Liang, Bo; Li, Guo-Lian; Chen, Tian-Hu

    2012-11-01

    Halogenated organic contaminants (HOCs) including 16 polybrominated diphenyl ethers (PBDEs) and 37 polychlorinated biphenyls (PCBs) were determined in 49 surfacial sediments from Chaohu Lake, a highly eutrophicated lake, China. PBDEs were detected in almost samples with the range of the total concentration (defined as Σ(16)PBDEs) from 0.84 to 86.6 ng g(-1). Compared with the occurrence of PBDEs in Pearl River Delta and Yangtze River Delta in China, lower percentage of BDE-209 over the concentration of Σ(16)PBDEs was inferred by the high-volume application of penta-BDE mixture product for local domestic furniture purpose. The total concentration of 37 PCBs (Σ(37)PCBs) ranged from 0.05 to 3.36 ng g(-1) with the most detection of PCB-1, -4, -52 and -71. Both the concentrations of Σ(16)PBDE and Σ(37)PCB poorly correlated with total organic carbon (TOC), suggesting the significant contribution of phytoplankton organic carbons to sediment TOC. The contamination by PBDEs and PCBs in western region of the lake was significantly more serious than in eastern lake. Our findings about the higher residues of PBDEs and PCBs in sediments at the estuary of Nanfei River compared to the other estuaries also supported the conclusion that urban area (Hefei city) was the main source of PBDEs and PCBs. The comparison with the concentration of HOC in the present study with those in other lacustrine sediments around the world suggested the contamination by PBDEs in Chaohu Lake is at middle of the global concentration range, whereas PCBs is at low end of the global range which could be elucidated by local economic development and historical usage of PBDEs and PCBs. The mass inventories of HOCs in the lake were estimated at 561 and 38 kg, which corresponds to only 0.000006% and 0.0001% of these global historical produce volumes, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Influences of binding to dissolved organic matter on hydrophobic organic compounds in a multi-contaminant system: Coefficients, mechanisms and ecological risks.

    Science.gov (United States)

    Li, Yi-Long; He, Wei; Liu, Wen-Xiu; Kong, Xiang-Zhen; Yang, Bin; Yang, Chen; Xu, Fu-Liu

    2015-11-01

    The complexation flocculation (CF) method was successfully employed to identify binding coefficients (Kdoc) of specific organic contaminants to dissolved organic matter (DOM, often indicated by dissolved organic carbon, DOC) in a multi-contaminant hydrophobic organic contaminant (HOC) system. Kdoc values were obtained for most of the evaluated 33 HOCs, indicating the feasibility and applicability of the CF method in a multi-contaminant system. Significant positive correlations were observed between binding coefficients and octanol-water partition coefficients (Kow) for organic halogen compounds, such as polybrominated diphenyl ethers (PBDEs) (R(2) = 0.95, p mechanisms between PAHs and organic halogen compounds exist. These differences further result in discriminative competition partitions of HOCs between DOM and organisms. Assuming that only freely dissolved HOCs are bioconcentrative, the results of DOM-influenced bioconcentration factor (BCFDOM) and DOM-influenced lowest observed effect level (LOELDOM) indicate that the ecological risk of HOCs is decreased by DOM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Sono-catalytic degradation of organic compounds

    International Nuclear Information System (INIS)

    Navarro, N.

    2012-01-01

    Unlike aqueous effluents from the PUREX process, aqueous effluents from advanced separation processes developed to separate the minor actinides (Am, Cm) contain organic reagents in large amounts. To minimize the impact of these organic compounds on the next steps of the process, and to respect standard discharges, it is necessary to develop new techniques of degradation of organic compounds. Sono-chemistry appears as a very promising solution to eliminate organic species in aqueous nuclear effluents. Indeed, the propagation of an ultrasonic wave in a liquid medium induces the appearance of cavitation bubbles which will quickly grow and implode, causing local conditions and extreme temperatures and pressures. Each cavitation bubble can then be considered as a microreactor at high temperature and high pressure able to destroy organic molecules without the addition of specific reagents. The first studies on the effect of ultrasonic frequency on sono-luminescence and sono-lysis of formic acid have shown that the degradation of formic acid occurs at the bubble/liquid interface. The most striking difference between low-frequency and high-frequency ultrasound is that the sono-lysis of HCOOH at high ultrasonic frequencies initiates secondary reactions not observed at 20 kHz. However, despite a much higher sono-chemical activity at high frequency, highly concentrated carboxylic acids in the aqueous effluents from advanced separation processes cannot be destroyed by ultrasound alone. To increase the efficiency of sono-chemical reactions, the addition of supported platinum catalysts has been studied. In these conditions, an increase of the kinetics of destruction of carboxylic acids such as oxalic acid is observed. (author) [fr

  11. The fight against Volatile Organic Compounds (VOC)

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This paper strikes the balance of the fight against organic volatile compounds emissions in France and in Europe. The first part describes the influence of VOC on production of Ozone in troposphere and gives numerical data on permissive emission values in atmosphere. The second part describes french and european policy and regulations. The third part gives the principle methods and devices for COV measurement in the atmosphere. In the last part, effluents treatment is given: thermal incineration, catalytic incineration, adsorption on active carbon, biologic purification, condensation and separative processes on membrane

  12. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

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

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to 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 degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three

  13. Lipid–water partition coefficients and correlations with uptakes by algae of organic compounds

    International Nuclear Information System (INIS)

    Hung, Wei-Nung; Chiou, Cary T.; Lin, Tsair-Fuh

    2014-01-01

    Graphical abstract: - Highlights: • Partition coefficients of contaminants with lipid triolein (K tw ) are measured. • Measured K tw values are nearly the same as the respective K ow . • Sorption of the contaminants to a dry algal powder is similarly measured. • Algal uptake of a compound occurs primarily by partition into the algal lipid. - Abstract: In view of the scarcity of the lipid–water partition coefficients (K tw ) for organic compounds, the log K tw values for many environmental contaminants were measured using ultra-pure triolein as the model lipid. Classes of compounds studied include alkyl benzenes, halogenated benzenes, short-chain chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. In addition to log K tw determination, the uptakes of these compounds from water by a dry algal species were measured to evaluate the lipid effect on the algal uptake. The measured log K tw are closely related to their respective log K ow (octanol–water), with log K ow = 1.9 to 6.5. A significant difference is observed between the present and early measured log K tw for compounds with log K ow > ∼5, which is attributed to the presence and absence of a triolein microemulsion in water affecting the solute partitioning. The observed lipid-normalized algae–water distribution coefficients (log K aw/lipid ) are virtually identical to the respective log K tw values, which manifests the dominant lipid-partition effect of the compounds with algae

  14. Special syntheses of certain organic iodine compounds

    International Nuclear Information System (INIS)

    Henry, R.; Debuchy, D.; Junod, E.

    1960-01-01

    The technical difficulties encountered in working on radioactive products force us to choose the simplest methods of chemical synthesis possible. For iodine compounds, two special methods have been chosen: - by using fission recoil, we can prepare simple iodine compounds such as iodobenzene or methyl iodide in high yields and having a good degree of purity. The method consists in the irradiation of mixtures of uranium oxide and benzoic acid or ammonium acetate. The iodised product is separated by distillation, after dissolving the recoil medium in a solvent. - by isotopic exchange between the inorganic iodine of different valencies and complex molecules such as Bengal pink, and diodone, it is also possible to obtain satisfactory labelling yields. These reactions have been adapted so as to give a minimum time for isotopic exchange. In the case of Bengal pink, we have found a yield of 90 per cent after 60 minutes by exchange between Nal and the organic molecule in aqueous solution in presence of hydrogen peroxide. For diodone the method proposed by Liebster has been modified so as to reduce losses during purification. The analytical methods adopted for these different compounds are described. (author) [fr

  15. Toxic organic compounds from energy production

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Complex Treatment of Soils, Waste Water and Groundwater Contaminated by Halogenated Organic Compounds.

    Czech Academy of Sciences Publication Activity Database

    Kaštánek, František; Maléterová, Ywetta; Kaštánek, P.; Rott, J.; Jiřičný, Vladimír; Jirátová, Květa

    2007-01-01

    Roč. 211, č. 1-3, (2007) , s. 261-271 ISSN 0011-9164. [Environmental Science and Technology Symposium /9./. Rhodes, 01.09.2005-03.09.2005] R&D Project s: GA ČR(CZ) GA104/03/0407; GA MPO FI-IM3/050 Institutional research plan: CEZ:AV0Z40720504 Keywords : vinyl chloride * waste and underground water * fenton reaction Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.875, year: 2007

  17. Haloperoxidase-like activity in spruce forest soil. A source of volatile halogenated organic compounds?

    DEFF Research Database (Denmark)

    Laturnus, F.; Mehrtens, G.; Grøn, C.

    1995-01-01

    Haloperoxidase-like activity was monitored in samples from a podzol soil in an uncontaminated spruce forest at Klosterhede, Denmark. Activity for the oxidation of chloride and bromide was found. The pH optima for chlorination and bromination ranged between pH 2.5 and 4: Very high activity, up to 4...

  18. Nitrate radicals and biogenic volatile organic compounds ...

    Science.gov (United States)

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

  19. In vivo evaluation of an antibacterial coating containing halogenated furanone compound-loaded poly(l-lactic acid) nanoparticles on microarc-oxidized titanium implants.

    Science.gov (United States)

    Cheng, Yicheng; Gao, Bo; Liu, Xianghui; Zhao, Xianghui; Sun, Weige; Ren, Huifang; Wu, Jiang

    2016-01-01

    To prevent peri-implant infection, a new antibacterial coating containing a halogenated furanone compound, (Z-)-4-bromo-5-(bromomethylene)-2(5H)-furanone-loaded poly(l-lactic acid) nanoparticles, has been fabricated. The current study was designed to evaluate the preventive effect of the antibacterial coating under a simulated environment of peri-implant infection in vivo. Microarc-oxidized titanium implants treated with minocycline hydrochloride ointment were used as positive control group, and microarc-oxidized titanium implants without any treatment were used as blank control group. Three kinds of implants were implanted in dogs' mandibles, and the peri-implant infection was simulated by silk ligation and feeding high sugar diet. After 2-month implantation, the results showed that no significant differences were detected between the experimental and positive control groups (P>0.05), but the data of clinical measurements of the blank control group were significantly higher than those of the other two groups (Pmicroscope observation and histological examination showed that more new bone was formed on the surface of the experimental and positive control groups. It can be concluded that the antibacterial coating fabricated on implants has remarkable preventive effect on peri-implant infection at the early stage.

  20. Bioaccumulation and biomagnification of classical flame retardants, related halogenated natural compounds and alternative flame retardants in three delphinids from Southern European waters

    International Nuclear Information System (INIS)

    Barón, E.; Giménez, J.; Verborgh, P.; Gauffier, P.; De Stephanis, R.; Eljarrat, E.; 2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona (Spain))" data-affiliation=" (Institute of Environmental Assessment and Water Research Studies (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona (Spain))" >Barceló, D.

    2015-01-01

    Occurrence and behaviour of classical (PBDEs) and alternative (HNs, HBB, PBEB, DBDPE and HBCD) flame retardants, together with naturally produced MeO-PBDEs, were studied in short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and long-finned pilot whale (Globicephala melas) in two sampling locations from Southern European waters. PBDEs, Dec 602, Dec 603, DP, α-HBCD and two MeO-PBDEs were detected in all three species. ∑PBDEs were between 17 and 2680 ng/g lw; ∑HNs were between 1.1 and 59 ng/g lw; α-HBCD levels ranged between 3.2 and 641 ng/g lw; ∑MeO-PBDEs were between 34 and 1966 ng/g lw. Bottlenose dolphins were the most contaminated species and some individuals could present health risk for endocrine disruption since levels found were above the reported threshold (1500 ng/g lw). Stable isotope analysis was used to evaluate the biomagnification capacity of these compounds. PBDEs, MeO-PBDEs and Dec 602 showed a significant positive correlation with trophic position. - Highlights: • Several FRs were detected in three dolphin species from Southern European waters. • Concentrations of classical FRs were higher than concentrations of alternative FRs. • MeO-PBDE concentrations were generally similar to PBDE concentrations. • Evidence of biomagnification capacity of some FRs was observed. • Some individuals were above the threshold level associated to endocrine disruption. - Bioaccumulation and biomagnification of halogenated compounds in dolphins

  1. Process for reducing halogen impurities in oil products

    Energy Technology Data Exchange (ETDEWEB)

    Basler, F.

    1990-08-14

    Oil products, in particular waste oils, may be efficiently reprocessed according to an economic and technically simple method for removing impurities, notably halogens. In this method, the oil product is treated at temperatures up to about 150{degree}C with an effective amount of an aqueous solution of at least one compound selected from the group consisting of a strong acid, a salt of a weak base and a strong acid and precursors thereof. The oil product obtained in this step is treated at increased temperatures with at least one halogen binding agent. The water and/or solids from the product so treated are separated out. The process of the invention can be carried out in a conventional stripping apparatus. The strong acid used in the first step is preferably selected from sulfurous acid, phosphoric acid, phosphorous acid, and phosphonic acid. The salt of the weak base and strong acid is preferably ammonium sulfate, ammonium bisulfate, ammonium sulfite, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphite, and ammonium phosphonic acid. The second step of the method is preferably a coagulation step in which organic halogen compounds break down into hydrogen halides which are neutralized by the added halogen binding agents. The preferred halogen binding agents are ammonia and/or an organic base. The coagulation is preferably carried out in heat exchangers so that the oil is heated in 3 stages and the oil from each stage is passed through a cascade tower. In the third step, additives may be used to enhance separation of the oil. Experiments are described to illustrate the method of the invention. 1 tab.

  2. Organic compounds as indicators of air pollution

    DEFF Research Database (Denmark)

    Mølhave, Lars

    2003-01-01

    The most important indoor air pollutants have already been addressedwith individual national guidelines or recommendations. However, an interna-tional set of guidelines or recommendations for indoor air quality (IAQ) isneeded for these pollutants based on general and uniform rules for setting...... suchstandards. A major research need exist on the less adverse pollutants beforerecommendations or guidelines can be established. In the interim period a pre-caution principle should lead to an ALARA principle for these secondary cau-salities. It should be noted that volatile organic compound (VOC......) is an indicatorfor the presence of VOC indoors. The TVOC indicator can be used in relation toexposure characterization and source identification but for VOCs only, not as anindictor of other pollutants and their health effects. In risk assessment the TVOCindicator can only be used as a screening tool and only...

  3. Adsorption of Organic Compounds to Building Products

    DEFF Research Database (Denmark)

    Kjær, Ulla Dorte

    The presence of VOCs (Volatile Organic Compounds) in the indoor air may be a contributory cause of complaints about irritation of mucous membranes in eyes, nose and throat, difficulty in breathing, frequent airway inflammation, skin irritation, fatigue, concentration difficulty, dizziness and hea...... (6 pages). Detailed summary in English (15 pages). Background (23 pages). Objective and hypotheses (2 pages). Methods and materials (20 pages). Results (26 pages). Discussion (12 pages). Conclusion (3 pages). References (14 pages). Appendices (95 pages)....... on sorption equilibrium and kinetics of temperature, relative humidity, VOC concentrations and air velocity past the surface of the building product. Four common building materials were carefully selected for the sorption/desorption experiments: Painted gypsum board, lacquered beechwood parquet, PVC flooring...

  4. Simulations of charge transport in organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Vehoff, Thorsten

    2010-05-05

    We study the charge transport properties of organic liquid crystals, i.e. hexabenzocoronene and carbazole macrocycle, and single crystals, i.e. rubrene, indolocarbazole and benzothiophene derivatives (BTBT, BBBT). The aim is to find structure-property relationships linking the chemical structure as well as the morphology with the bulk charge carrier mobility of the compounds. To this end, molecular dynamics (MD) simulations are performed yielding realistic equilibrated morphologies. Partial charges and molecular orbitals are calculated based on single molecules in vacuum using quantum chemical methods. The molecular orbitals are then mapped onto the molecular positions and orientations, which allows calculation of the transfer integrals between nearest neighbors using the molecular orbital overlap method. Thus we obtain realistic transfer integral distributions and their autocorrelations. In case of organic crystals the differences between two descriptions of charge transport, namely semi-classical dynamics (SCD) in the small polaron limit and kinetic Monte Carlo (KMC) based on Marcus rates, are studied. The liquid crystals are investigated solely in the hopping limit. To simulate the charge dynamics using KMC, the centers of mass of the molecules are mapped onto lattice sites and the transfer integrals are used to compute the hopping rates. In the small polaron limit, where the electronic wave function is spread over a limited number of neighboring molecules, the Schroedinger equation is solved numerically using a semi-classical approach. The carbazole macrocycles form columnar structures arranged on a hexagonal lattice with side chains facing inwards, so columns can closely approach each other allowing inter-columnar and thus three-dimensional transport. We are able to show that, on the time-scales of charge transport, static disorder due to slow side chain motions is the main factor determining the mobility. The high mobility of rubrene is explained by two main

  5. Typical halogenated persistent organic pollutants in indoor dust and the associations with childhood asthma in Shanghai, China

    International Nuclear Information System (INIS)

    Meng, Ge; Nie, Zhiqing; Feng, Yan; Wu, Xiaomeng; Yin, Yong; Wang, Yan

    2016-01-01

    Halogenated persistent organic pollutants (Hal-POPs) are significant contaminants in the indoor environment that are related to many human diseases. Ingestion of indoor dust is considered the major pathway of Hal-POP exposures, especially for children aged 3–6 years. Alongside a retrospective study on the associations between typical Hal-POP exposure and childhood asthma in Shanghai, indoor dust samples from asthmatic and non-asthmatic children's homes (n = 60, each) were collected. Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured by GC–MS. BDE-209, PCB-8 and p,p′-DDE were the predominant components in each chemical category. The concentrations of most Hal-POPs were significantly higher in the asthmatic families. The associations between Hal-POP exposure and asthma occurrence were examined by calculating the odds ratios (ORs) using a logistic regression model. A positive association was found between p,p′-DDE in indoor dust and childhood asthma (OR = 1.825, 95%CI: 1.004, 3.317; p = 0.048). The average daily doses of Hal-POP intake were calculated using the method provided by the USEPA. Non-carcinogenic health risks were preliminarily assessed. Our study indicated that exposure to p,p’-DDE via indoor dust may contribute to childhood asthma occurrence. Non-carcinogenic health risks were not found with the intake of Hal-POPs via the ingestion of indoor dust. - Highlights: • Three POP species were measured in indoor dust from the homes of asthmatic and non-asthmatic children. • The concentrations of BDE-47/-99/-209, PCB-8/-49 and p,p’-DDE were significantly higher in the case group. • p,p′-DDE showed positive association with childhood asthma occurrence. • Hal-POP exposure via ingestion of indoor dust was not associated with non-carcinogenic health risks. - The concentrations of select Hal-POPs in dust were determined, and a positive association was found between p

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

    African Journals Online (AJOL)

    GCMS), was used to identify volatile compounds at three different temperatures. Fifty volatile compounds, inclusive of 14 acids, 14 alcohols, and 22 esters were identified and quantified in the two brands of indigenous banana beer samples. Only 12 ...

  7. New uranium compounds preparation and use as catalyst for hydrogenation of non-saturated organic compounds

    International Nuclear Information System (INIS)

    Arnaudet, L.; Folcher, G.

    1985-01-01

    Preparation of new organic uranium compounds and their use as catalysts for hydrogenation of non-saturated organic compounds are described. These compounds include Uranium III, a cyclopentadienic group, an alkyl group and an acetylenic derivative C 6 H 5 C triple bonds CR fixed by a π bond. Catalysts can be prepared with depleted uanium for hydrogenation of olefins for example [fr

  8. Investigations on organogermanium compounds XII. Reactions of trialkylgermylalkalimetal compounds in hexamethylphosphoric triamide (HMPT) with some inorganic and organic compounds

    NARCIS (Netherlands)

    Bulten, E.J.; Noltes, J.G.

    1971-01-01

    Trialkylgermyl alkali metal compounds in HMPT have been found to be highly reactive nucleophiles. Reactions with some inorganic and organic compounds, such as oxygen, carbon dioxide, inorganic and orgaanic halides, aldehydes, ketones, epoxides and lactones are described. Several new

  9. Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana).

    Science.gov (United States)

    Tue, Nguyen Minh; Goto, Akitoshi; Takahashi, Shin; Itai, Takaaki; Asante, Kwadwo Ansong; Kunisue, Tatsuya; Tanabe, Shinsuke

    2016-01-25

    Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Organic compounds in concrete from demolition works.

    Science.gov (United States)

    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. Copyright © 2015. Published by Elsevier Ltd.

  11. International protocol on volatile organic compounds

    International Nuclear Information System (INIS)

    Gauthier, J.-P.

    1992-01-01

    In August 1991, negotiations between Canada, the USA, and 33 European countries led to an international protocol on reducing the emissions of volatile organic compounds (VOC), which are responsible for serious ozone pollution problems. This was the third transborder pollution agreement developed under the auspices of the United Nations Economic Commission for Europe. Certain aspects of negotiations related to an earlier protocol developed for SO 2 and nitrogen oxide emissions had reappeared during the VOC negotiations, and these aspects are discussed. The VOC protocol proposes three approaches to satisfy basic obligations: reducing VOC emissions of a country by 30%, reducing VOC emissions by 30% in certain regions, and ensuring a freeze in VOC emissions in a country starting on a specified date. The protocol also introduces a new concept, that of zones of tropospheric ozone management. In Canada, plans for management of nitrogen oxides and VOC have been adapted to the ozone problem, and the management plan has been developed by a consultation process involving all sectors of society including industry, environmental groups, and governments. In Canada, it will be sufficient to reduce total VOC emissions by 16% during a first phase and to increase these reductions slightly in the second phase. Special ozone management zones in the Quebec City/Windsor corridor and the Fraser River valley have been established

  12. Organic compounds in radiation fogs in Davis (California)

    Science.gov (United States)

    Herckes, Pierre; Hannigan, Michael P.; Trenary, Laurie; Lee, Taehyoung; Collett, Jeffrey L.

    New stainless steel active fogwater collectors were designed and used in Davis (CA, USA) to collect fogwater for the speciation of organic matter. Organic compounds in fog samples were extracted by liquid-liquid extraction and analyzed by gas chromatography coupled to mass spectrometry. Numerous organic compounds, including various alkanes, polycyclic aromatic hydrocarbons (PAH) and alkanoic acids, have been identified in the fogwater samples. Higher molecular weight (MW) compounds are preferentially associated with an insoluble phase inside the fog drops, whereas lower molecular weight and more polar compounds are found predominantly in the dissolved phase. Concentrations in the dissolved phase were sometimes much higher than estimated by the compounds' aqueous solubilities.

  13. Mechanochemical synthesis of organic compounds and composites with their participation

    Energy Technology Data Exchange (ETDEWEB)

    Lyakhov, Nikolai Z; Grigorieva, Tatiana F; Barinova, Antonina P; Vorsina, I A [Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2010-05-13

    The results of experimental studies in the mechanochemical synthesis of organic compounds and composites with their participation published over the last 15 years are described systematically. The key reactions of organic compounds are considered: synthesis of the salts of organic acids, acylation, substitution, dehalogenation, esterification, hydrometallation and other reactions. Primary attention is devoted to systems and compounds that cannot be obtained by traditional chemistry methods.

  14. ANTIMICROBIAL REAGENTS AS FUNCTIONAL FINISHING FOR TEXTILES INTENDED FOR BIOMEDICAL APPLICATIONS. I. SYNTHETIC ORGANIC COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Madalina Zanoaga

    2014-06-01

    Full Text Available This article offers an overview of some contemporary antimicrobial (biocides and biostatics agents used as functional finishing for textiles intended for biomedical applications. It reviews only synthetic agents, namely quaternary ammonium compounds, halogenated phenols, polybiguanides, N-halamines, and renewable peroxides, as a part of an extensive study currently in progress.

  15. Volatile organic compound measurements in the California/Mexico border region during SCOS97

    International Nuclear Information System (INIS)

    Zielinska, B.; Sagebiel, J.; Harshfield, G.; Pasek, R.

    2001-01-01

    Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone Study in the summer of 1997 (SCOS97). Integrated 3-h samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during intensive operational periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6-l canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C18 SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C 2 -C 12 ), CO, CO 2 , CH 4 , methyl t-butyl ether (MTBE), and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for 14 C 1 -C 7 carbonyl compounds. The concentrations of all species were higher at Mexicali than in Rosarito. A good correlation between total non-methane hydrocarbons (TNMHC), CO, and other pollutants associated with motor vehicle emissions observed for Mexicali indicates that the main source of TNMHC at this site is vehicular traffic

  16. A field comparison of volatile organic compound measurements using passive organic vapor monitors and stainless steel canisters.

    Science.gov (United States)

    Pratt, Gregory C; Bock, Don; Stock, Thomas H; Morandi, Maria; Adgate, John L; Ramachandran, Gurumurthy; Mongin, Steven J; Sexton, Ken

    2005-05-01

    Concurrent field measurements of 10 volatile organic compounds (VOCs) were made using passive diffusion-based organic vapor monitors (OVMs) and the U.S. Federal Reference Method, which comprises active monitoring with stainless steel canisters (CANs). Measurements were obtained throughout a range of weather conditions, repeatedly over the course of three seasons, and at three different locations in the Minneapolis/St. Paul metropolitan area. Ambient concentrations of most VOCs as measured by both methods were low compared to those of other large metropolitan areas. For some VOCs a considerable fraction of measurements was below the detection limit of one or both methods. The observed differences between the two methods were similar across measurement sites, seasons, and meteorological variables. A Bayesian analysis with uniform priors on the differences was applied, with accommodation of sometimes heavy censoring (nondetection) in either device. The resulting estimates of bias and standard deviation of the OVM relative to the CAN were computed by tertile of the canister-measured concentration. In general, OVM and CAN measurements were in the best agreement for benzene and other aromatic compounds with hydrocarbon additions (ethylbenzene, toluene, and xylenes). The two methods were not in such good agreement for styrene and halogenated compounds (carbon tetrachloride, p-dichlorobenzene, methylene chloride, and trichloroethylene). OVMs slightly overestimated benzene concentrations and carbon tetrachloride at low concentrations, but in all other cases where significant differences were found, OVMs underestimated relative to canisters. Our study indicates that the two methods are in agreement for some compounds, but not all. We provide data and interpretation on the relative performance of the two VOC measurement methods, which facilitates intercomparisons among studies.

  17. Lipid–water partition coefficients and correlations with uptakes by algae of organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Wei-Nung [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 30011, Taiwan (China); Chiou, Cary T., E-mail: carychio@mail.ncku.edu.tw [Department of Environmental Engineering and Sustainable Environment Research Laboratory, National Cheng Kung University, Tainan 70101, Taiwan (China); U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States); Lin, Tsair-Fuh, E-mail: tflin@mail.ncku.edu.tw [Department of Environmental Engineering and Sustainable Environment Research Laboratory, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2014-08-30

    Graphical abstract: - Highlights: • Partition coefficients of contaminants with lipid triolein (K{sub tw}) are measured. • Measured K{sub tw} values are nearly the same as the respective K{sub ow}. • Sorption of the contaminants to a dry algal powder is similarly measured. • Algal uptake of a compound occurs primarily by partition into the algal lipid. - Abstract: In view of the scarcity of the lipid–water partition coefficients (K{sub tw}) for organic compounds, the log K{sub tw} values for many environmental contaminants were measured using ultra-pure triolein as the model lipid. Classes of compounds studied include alkyl benzenes, halogenated benzenes, short-chain chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. In addition to log K{sub tw} determination, the uptakes of these compounds from water by a dry algal species were measured to evaluate the lipid effect on the algal uptake. The measured log K{sub tw} are closely related to their respective log K{sub ow} (octanol–water), with log K{sub ow} = 1.9 to 6.5. A significant difference is observed between the present and early measured log K{sub tw} for compounds with log K{sub ow} > ∼5, which is attributed to the presence and absence of a triolein microemulsion in water affecting the solute partitioning. The observed lipid-normalized algae–water distribution coefficients (log K{sub aw/lipid}) are virtually identical to the respective log K{sub tw} values, which manifests the dominant lipid-partition effect of the compounds with algae.

  18. Chemical Reductive Transformations of Synthetic Organic Compounds

    National Research Council Canada - National Science Library

    Peyton, Gary

    2001-01-01

    Advanced Oxidation Processes (AOPs) can be used to selectively remove DNT (2,4-dinitrotoluene) from a complex waste stream by adding a precursor compound such as ethanol which forms a reducing radical upon reaction with hydroxyl radical...

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

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... have entered the commercial market, both in rural areas ... nation of volatile compounds include: gas chromate- graphy (GC) ... prior to the actual analysis, various extraction methods ..... traditional and industrial 'orujo' spirits.

  20. Salt lakes of Western Australia - Natural abiotic formation of volatile organic compounds

    Science.gov (United States)

    Krause, T.; Studenroth, S.; Mulder, I.; Tubbesing, C.; Kotte, K.; Ofner, J.; Junkermann, W.; Schöler, H. F.

    2012-04-01

    Western Australia is a semi-/arid region that is heavily influenced by global climate change and agricultural land use. The area is known for its many ephemeral saline and hypersaline lakes with a wide range of hydrogeochemical parameters that have gradually changed over the last fifty years. Historically, the region was covered by eucalyptus trees and shrubs, but was cleared mainly within 10 years after WWII to make room for wheat and live stock. After the clearance of the deep rooted native plants the groundwater started to rise, bringing increased amounts of dissolved salts and minerals to the surface and discharging them into streams and lakes. Thus most of Western Australia is influenced by secondary salinisation (soil salting) [1]. Another problem is that the discharged minerals affect the pH of ground and surface water, which ranges from acidic to slightly basic. During the 2011 campaign surface water was measured with a pH between 2.5 and 7.1. Another phenomenon in Western Australia is the decrease of rainfall over the last decades assumed to be linked to the secondary salinisation. The rising saline and mineral rich groundwater increases the biotical and abiotical activity of the salt lakes. Halogenated and non-halogenated volatile organic compounds emitted from those lakes undergo fast oxidation and chemical reactions to form small particles modifying cloud microphysics and thus suppressing rain events [2]. Our objective is to gain a better understanding of this extreme environment with its hypersaline acidic lakes with regard to the potential abiotic formation of volatile organic compounds and its impact on the local climate. In spring 2011 fifty-three sediment samples from ten salt lakes in the Lake King region where taken, freeze-dried and ground. In order to simulate the abiotic formation of volatile organic compounds the soil samples were resuspended with water in gas-tight headspace vials. The headspace was measured using a purge and trap GC

  1. Small-Molecule Organic Photovoltaic Modules Fabricated via Halogen-Free Solvent System with Roll-to-Roll Compatible Scalable Printing Method.

    Science.gov (United States)

    Heo, Youn-Jung; Jung, Yen-Sook; Hwang, Kyeongil; Kim, Jueng-Eun; Yeo, Jun-Seok; Lee, Sehyun; Jeon, Ye-Jin; Lee, Donmin; Kim, Dong-Yu

    2017-11-15

    For the first time, the photovoltaic modules composed of small molecule were successfully fabricated by using roll-to-roll compatible printing techniques. In this study, blend films of small molecules, BTR and PC 71 BM were slot-die coated using a halogen-free solvent system. As a result, high efficiencies of 7.46% and 6.56% were achieved from time-consuming solvent vapor annealing (SVA) treatment and roll-to-roll compatible solvent additive approaches, respectively. After successful verification of our roll-to-roll compatible method on small-area devices, we further fabricated large-area photovoltaic modules with a total active area of 10 cm 2 , achieving a power conversion efficiency (PCE) of 4.83%. This demonstration of large-area photovoltaic modules through roll-to-roll compatible printing methods, even based on a halogen-free solvent, suggests the great potential for the industrial-scale production of organic solar cells (OSCs).

  2. Mass spectrometric investigation of vinyl-substituted organic boron compounds

    International Nuclear Information System (INIS)

    Tarielashvili, V.O.; Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.

    1992-01-01

    Mass spectrometric investigation of vinyl-substituted organic compounds was conducted. Ionization was performed by electron shock. Possibility of determining boron isotope content is all analyzed organic boron vinyl-substituted compounds by direct method is shown. This simplifies sufficiently and lowers the price of analysis, improves its accuracy and rapidity

  3. Energy Efficient Removal of Volatile Organic Compounds (VOCs) and Organic Hazardous Air Pollutants (o-HAPs) from Industrial Waste Streams by Direct Electron Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Testoni, A. L.

    2011-10-19

    This research program investigated and quantified the capability of direct electron beam destruction of volatile organic compounds and organic hazardous air pollutants in model industrial waste streams and calculated the energy savings that would be realized by the widespread adoption of the technology over traditional pollution control methods. Specifically, this research determined the quantity of electron beam dose required to remove 19 of the most important non-halogenated air pollutants from waste streams and constructed a technical and economic model for the implementation of the technology in key industries including petroleum refining, organic & solvent chemical production, food & beverage production, and forest & paper products manufacturing. Energy savings of 75 - 90% and green house gas reductions of 66 - 95% were calculated for the target market segments.

  4. Halogen bond: a long overlooked interaction.

    Science.gov (United States)

    Cavallo, Gabriella; Metrangolo, Pierangelo; Pilati, Tullio; Resnati, Giuseppe; Terraneo, Giancarlo

    2015-01-01

    Because of their high electronegativity, halogen atoms are typically considered, in most of their derivatives, as sites of high electron density and it is commonly accepted that they can form attractive interactions by functioning as the electron donor site (nucleophilic site). This is the case when they work as hydrogen bond acceptor sites. However, the electron density in covalently bound halogens is anisotropically distributed. There is a region of higher electron density, accounting for the ability of halogens to function as electron donor sites in attractive interactions, and a region of lower electron density where the electrostatic potential is frequently positive (mainly in the heavier halogens). This latter region is responsible for the ability of halogen atoms to function as the electron-acceptor site (electrophilic site) in attractive interactions formed with a variety of lone pair-possessing atoms, anions, and π-systems. This ability is quite general and is shown by a wide diversity of halogenated compounds (e.g., organohalogen derivatives and dihalogens). According to the definition proposed by the International Union of Pure and Applied Chemistry, any attractive interactions wherein the halogen atom is the electrophile is named halogen bond (XB). In this chapter, it is discussed how the practice and the concept of XB developed and a brief history of the interaction is presented. Papers (either from the primary or secondary literature) which have reported major experimental findings in the field or which have given important theoretical contributions for the development of the concept are recollected in order to trace how a unifying and comprehensive categorization emerged encompassing all interactions wherein halogen atoms function as the electrophilic site.

  5. [Composition characteristics of atmospheric volatile organic compounds in the urban area of Beibei District, Chongqing].

    Science.gov (United States)

    Qi, Xin; Hao, Qing-ju; Ji, Dong-sheng; Zhang, Jun-ke; Liu, Zi-rui; Hu, Bo; Wang, Yue-si; Jiang, Chang-sheng

    2014-09-01

    In order to study the composition and distribution of VOCs (Volatile Organic Compounds) in the atmosphere in the urban area of Beibei district, Chongqing, atmospheric samples were collected from March 2012 to February 2013 with special stainless steel cylinders, and analyzed with a three-stage preconcentration method coupled with GC-MS. 78 species of VOCs were detected in this study, of which there were 25 species of alkanes, 15 species of olefins, 28 species of aromatic hydrocarbons and 10 species of halogenated hydrocarbons. The results showed that the top seven species of VOCs according to the order of annual average concentration in the atmosphere of Beibei were: Dichloromethane (3. 08 x 10(-9) ) , Benzene (2. 09 x 10-9) , Isopentane (1. 85 x 10 -9) , Toluene (1. 51 x 10(-9)) , Propane (1. 51 x 10(-9)), m/p-xylene (1.43 x 10(-9)) and Styrene (1. 39 x 10-9). The concentration of TVOCs (Total Volatile Organic Compounds) in the atmosphere of Beibei was 33. 89 x 10 -9 during the measuring period, and the seasonal variation was obvious with the order of spring (42. 57 x 10 -9) > autumn (33.89 x 10-9) > winter (31.91 x 10 -9) > summer (27.04 x 10(-9)). In the composition of TVOCs, alkanes and aromatic hydrocarbons provided the largest contribution to TVOCs (31.5% and 30.7% ) , followed by halogenated hydrocarbon, accounting for 27.4% , and the last one was olefins, with only 10.4%. By means of ozone formation potential, the analysis results showed that olefins and aromatic hydrocarbon compounds were the two important materials which made the biggest contribution to the formation of ozone in the atmosphere of Beibei. We further analyzed the sources of VOCs in atmosphere of Beibei by the method of Principal Component Analysis (PCA). Vehicle exhaust was the biggest source and its contribution to VOCs was 50. 41%. The calculated results with T/B value also confirmed that traffic was the biggest source contributing to the VOCs in atmosphere of Beibei.

  6. Quantifying commuter exposures to volatile organic compounds

    Science.gov (United States)

    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

  7. Atmospheric degradation mechanism of organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T; Arsene, C

    2002-02-01

    In the present work a detailed product study has been performed on the OH radical initiated oxidation of dimethyl sulphide and dimethyl sulphoxide, under different conditions of temperature, partial pressure of oxygen and NO{sub x} concentration, in order to better define the degradation mechanism of the above compounds under conditions which prevail in the atmosphere. (orig.)

  8. Organic compounds in circumstellar and interstellar environments.

    Science.gov (United States)

    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.

  9. The role of different nonspecific interactions and halogen contacts in the crystal structure organization of 5-chloroisatoic anhydride.

    Science.gov (United States)

    Pogoda, Dorota; Matera-Witkiewicz, Agnieszka; Listowski, Marcin; Janczak, Jan; Videnova-Adrabinska, Veneta

    2018-03-01

    The crystal structure of 6-chloro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione (5-chloroisatoic anhydride), C 8 H 4 ClNO 3 , has been determined and analysed in terms of connectivity and packing patterns. The compound crystallizes in the noncentrosymmetric space group Pna2 1 with one molecule in the asymmetric unit. The role of different weak interactions is discussed with respect to three-dimensional network organization. Molecules are extended into one-dimensional helical arrangements, making use of N-H...O hydrogen bonds and π-π interactions. The helices are further organized into monolayers via weak C-H...O and lone pair-π interactions, and the monolayers are packed into a noncentrosymmetric three-dimensional architecture by C-Cl...π interactions and C-H...Cl and Cl...Cl contacts. A Hirshfeld surface (HS) analysis was carried out and two-dimensional (2D) fingerprint plots were generated to visualize the intermolecular interactions and to provide quantitative data for their relative contributions. In addition, tests of the antimicrobial activity and in vitro cytotoxity effects against fitoblast L929 were performed and are discussed.

  10. Synthesis of organic compounds 15 N enriched

    International Nuclear Information System (INIS)

    Oliveira, Claudineia Raquel de; Bendassolli, Jose Albertino; Prestes, Clelber Vieira; Tavares, Glauco Arnold

    2002-01-01

    The aim of this work was to develop urea- 15 N and glycine- 15 N synthesis for agronomic and biological studies. The production of these compounds was evaluated due to the fact of increasing use of urea, comparing to others solid fertilizers and the importance of glycine in the studies of protein metabolism. A non-conventional method was carried out to synthesize urea. The process involved reaction among Co, NH 3 anidrid and S at low temperature (100 deg C) and of pressure (0,81 mPa) compared to the conventional method. Monolise halets reaction was carried out for glycine synthesis with chloroacetic and ammonia 2 deg C. Both compounds are economic viable, they can be produced at a lower price than the trade market one. (author)

  11. Photocatalytic fluoroalkylation reactions of organic compounds

    OpenAIRE

    Barata Vallejo, Sebastian; Bonesi, Sergio Mauricio; Postigo, Jose Alberto

    2017-01-01

    Photocatalytic methods for fluoroalkyl-radical generation provide more convenient alternatives to the classical perfluoroalkyl-radical (Rf) production through chemical initiators, such as azo or peroxide compounds or the employment of transition metals through a thermal electron transfer (ET) initiation process. The mild photocatalytic reaction conditions tolerate a variety of functional groups and, thus, are handy to the late-stage modification of bioactive molecules. Transition metal-photoc...

  12. Inkjet-Printed Small-Molecule Organic Light-Emitting Diodes: Halogen-Free Inks, Printing Optimization, and Large-Area Patterning.

    Science.gov (United States)

    Zhou, Lu; Yang, Lei; Yu, Mengjie; Jiang, Yi; Liu, Cheng-Fang; Lai, Wen-Yong; Huang, Wei

    2017-11-22

    Manufacturing small-molecule organic light-emitting diodes (OLEDs) via inkjet printing is rather attractive for realizing high-efficiency and long-life-span devices, yet it is challenging. In this paper, we present our efforts on systematical investigation and optimization of the ink properties and the printing process to enable facile inkjet printing of conjugated light-emitting small molecules. Various factors on influencing the inkjet-printed film quality during the droplet generation, the ink spreading on the substrates, and its solidification processes have been systematically investigated and optimized. Consequently, halogen-free inks have been developed and large-area patterning inkjet printing on flexible substrates with efficient blue emission has been successfully demonstrated. Moreover, OLEDs manufactured by inkjet printing the light-emitting small molecules manifested superior performance as compared with their corresponding spin-cast counterparts.

  13. Binary systems solubilities of inorganic and organic compounds

    CERN Document Server

    Stephen, H

    1963-01-01

    Solubilities of Inorganic and Organic Compounds, Volume 1: Binary Systems, Part 1 is part of an approximately 5,500-page manual containing a selection from the International Chemical Literature on the Solubilities of Elements, Inorganic Compounds, Metallo-organic and Organic Compounds in Binary, Ternary and Multi-component Systems. A careful survey of the literature in all languages by a panel of scientists specially appointed for the task by the U.S.S.R. Academy of Sciences, Moscow, has made the compilation of this work possible. The complete English edition in five separately bound volumes w

  14. Organic compounds in hydraulic fracturing fluids and wastewaters: A review.

    Science.gov (United States)

    Luek, Jenna L; Gonsior, Michael

    2017-10-15

    High volume hydraulic fracturing (HVHF) of shale to stimulate the release of natural gas produces a large quantity of wastewater in the form of flowback fluids and produced water. These wastewaters are highly variable in their composition and contain a mixture of fracturing fluid additives, geogenic inorganic and organic substances, and transformation products. The qualitative and quantitative analyses of organic compounds identified in HVHF fluids, flowback fluids, and produced waters are reviewed here to communicate knowledge gaps that exist in the composition of HVHF wastewaters. In general, analyses of organic compounds have focused on those amenable to gas chromatography, focusing on volatile and semi-volatile oil and gas compounds. Studies of more polar and non-volatile organic compounds have been limited by a lack of knowledge of what compounds may be present as well as quantitative methods and standards available for analyzing these complex mixtures. Liquid chromatography paired with high-resolution mass spectrometry has been used to investigate a number of additives and will be a key tool to further research on transformation products that are increasingly solubilized through physical, chemical, and biological processes in situ and during environmental contamination events. Diverse treatments have been tested and applied to HVHF wastewaters but limited information has been published on the quantitative removal of individual organic compounds. This review focuses on recently published information on organic compounds identified in flowback fluids and produced waters from HVHF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Generation of standard gas mixtures of halogenated, aliphatic, and aromatic compounds and prediction of the individual output rates based on molecular formula and boiling point.

    Science.gov (United States)

    Thorenz, Ute R; Kundel, Michael; Müller, Lars; Hoffmann, Thorsten

    2012-11-01

    In this work, we describe a simple diffusion capillary device for the generation of various organic test gases. Using a set of basic equations the output rate of the test gas devices can easily be predicted only based on the molecular formula and the boiling point of the compounds of interest. Since these parameters are easily accessible for a large number of potential analytes, even for those compounds which are typically not listed in physico-chemical handbooks or internet databases, the adjustment of the test gas source to the concentration range required for the individual analytical application is straightforward. The agreement of the predicted and measured values is shown to be valid for different groups of chemicals, such as halocarbons, alkanes, alkenes, and aromatic compounds and for different dimensions of the diffusion capillaries. The limits of the predictability of the output rates are explored and observed to result in an underprediction of the output rates when very thin capillaries are used. It is demonstrated that pressure variations are responsible for the observed deviation of the output rates. To overcome the influence of pressure variations and at the same time to establish a suitable test gas source for highly volatile compounds, also the usability of permeation sources is explored, for example for the generation of molecular bromine test gases.

  16. Organic compounds preparation with 14 C

    International Nuclear Information System (INIS)

    Shirvani, Gholam Hossein.

    1996-09-01

    Active urea is a basic reagent for the synthesis of active uric-8- 14 C acid. In our manner, activated Barium carbonate with specified activity was placed in a special furnace with ability of passing gases. Then, ammonia gas was passed through it at about 850 Degree C to obtain Barium Cyanamide. Reaction of the produced compound with CO 2 , and then acidification of the mixture, gave activated urea. Condensation of the urea with Ethylcyanoacetate, produce 6-Aminouracil which upon nitrosation, reduction and then condensation with urea, the desired Uric-8- 14 C acid was synthesized. (author). 148 refs.,

  17. Phosphate incorporation in organic compounds in roots of maize

    International Nuclear Information System (INIS)

    Michalik, I.; Ivanko, S.

    1976-01-01

    32 P incorporation and metabolism was investigated for short exposure times of 1 sec, 10 sec and 1, 10, 30 and 120 min. By stepwise extraction with a methanol-chloroform-formic acid-water mixture, various fractions of P compounds were obtained. Low-molecular acid-soluble P compounds were separated by one-dimensional paper chromatography. Of the total amount of 32 P absorbed by the roots of maize in the form of phosphate ions during the short incubation time of 1 sec, more than 33% was incorporated into organic compounds. With increasing incubation time, the proportion of 32 P in low-molecular organic compounds increased with the decreasing proportion of inorganic phosphorus. In the 1 sec, exposure incorporation was found in 3 low-molecular organic compounds only, namely ATP, ADP and diphosphoglyceric acid. The 32 P incorporation into ATP and ADP, in contrast with incorporation into diphosphoglyceric acid, increased markedly with increased exposure time. (author)

  18. Dissociative Photoionization of 1-Halogenated Silacyclohexanes: Silicon Traps the Halogen.

    Science.gov (United States)

    Bodi, Andras; Sigurdardottir, Katrin Lilja; Kvaran, Ágúst; Bjornsson, Ragnar; Arnason, Ingvar

    2016-11-23

    The threshold photoelectron spectra and threshold photoionization mass spectra of 1-halogenated-1-silacyclohexanes, for the halogens X = F, Cl, Br, and I, have been obtained using synchrotron vacuum ultraviolet radiation and photoelectron photoion coincidence spectroscopy. As confirmed by a similar ionization onset and density functional theory molecular orbitals, the ionization to the ground state is dominated by electron removal from the silacyclohexane ring for X = F, Cl, and Br, and from the halogen lone pair for X = I. The breakdown diagrams show that the dissociative photoionization mechanism is also different for X = I. Whereas the parent ions decay by ethylene loss for X = F to Br in the low-energy regime, the iodine atom is lost for X = I. The first step is followed by a sequential ethylene loss at higher internal energies in each of the compounds. It is argued that the tendency of silicon to lower bond angles stabilizes the complex cation in which C 2 H 4 is η 2 -coordinated to it, and which precedes ethylene loss. Together with the relatively strong silicon-halogen bonds and the increased inductive effect of the silacyclohexane ring in stabilizing the cation, this explains the main differences observed in the fragmentation of the halogenated silacyclohexane and halogenated cyclohexane ions. The breakdown diagrams have been modeled taking into account slow dissociations at threshold and the resulting kinetic shift. The 0 K appearance energies have been obtained to within 0.08 eV for the ethylene loss for X = F to Br (10.56, 10.51, and 10.51 eV, respectively), the iodine atom loss for X = I (10.11 eV), the sequential ethylene loss for X = F to I (12.29, 12.01, 11.94, and 11.86 eV, respectively), and the minor channels of H loss for X = F (10.56 eV) and propylene loss in X = Cl (also at 10.56 eV). The appearance energies for the major channels likely correspond to the dissociative photoionization reaction energy.

  19. Molecular activation analysis for organo-halogen contaminants in yogurt

    International Nuclear Information System (INIS)

    Zhang Hong; Chai Zhifang

    2004-01-01

    The concentrations of total halogen (TX), extractable organo-halogen (EOX), extractable persistent organo-halogen (EPOX), organo-chlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in 18 different yogurt specimens of 14 brands from Beijing, Tianjin, Shanghai, Guangzhou and Shijiazhuang were determined by epithermal neutron activation analysis (ENAA), molecular activation analysis (MAA) and GC-Mass Spectrometry (GC-MS), respectively. The results indicated that the halogen in yogurt mainly existed as inorganic species and non-extractable organo-halogen compounds. About 1/3 to 1/4 of EOX was EPOX. Further, EOCl and EPOCl were the main organo-halogen species in yogurt. The average concentration of the unknown organo-chlorine was 96% of the EPOCl. HCHs and DDTs were still the main contaminants of OCPs in the yogurt of interest. Also, PCB202, PCB103 and PCB208 were the main contaminants of PCBs. (authors)

  20. Computational Tools To Model Halogen Bonds in Medicinal Chemistry.

    Science.gov (United States)

    Ford, Melissa Coates; Ho, P Shing

    2016-03-10

    The use of halogens in therapeutics dates back to the earliest days of medicine when seaweed was used as a source of iodine to treat goiters. The incorporation of halogens to improve the potency of drugs is now fairly standard in medicinal chemistry. In the past decade, halogens have been recognized as direct participants in defining the affinity of inhibitors through a noncovalent interaction called the halogen bond or X-bond. Incorporating X-bonding into structure-based drug design requires computational models for the anisotropic distribution of charge and the nonspherical shape of halogens, which lead to their highly directional geometries and stabilizing energies. We review here current successes and challenges in developing computational methods to introduce X-bonding into lead compound discovery and optimization during drug development. This fast-growing field will push further development of more accurate and efficient computational tools to accelerate the exploitation of halogens in medicinal chemistry.

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

    Data.gov (United States)

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

  2. Metal organic frameworks for removal of compounds from a fluid

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-03

    Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO2, H2S and condensable hydrocarbons. One or more of CO2, H2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

  3. Thermodynamic properties of organic compounds estimation methods, principles and practice

    CERN Document Server

    Janz, George J

    1967-01-01

    Thermodynamic Properties of Organic Compounds: Estimation Methods, Principles and Practice, Revised Edition focuses on the progression of practical methods in computing the thermodynamic characteristics of organic compounds. Divided into two parts with eight chapters, the book concentrates first on the methods of estimation. Topics presented are statistical and combined thermodynamic functions; free energy change and equilibrium conversions; and estimation of thermodynamic properties. The next discussions focus on the thermodynamic properties of simple polyatomic systems by statistical the

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

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  5. Metal organic frameworks for removal of compounds from a fluid

    KAUST Repository

    Eddaoudi, Mohamed; Belmabkhout, Youssef

    2016-01-01

    Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO2, H2S and condensable hydrocarbons. One or more of CO2, H2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

  6. Preparation of radioactive labelled compounds Pt.1. 82Br labelled organic bromine compounds

    International Nuclear Information System (INIS)

    Otto, R.

    1988-05-01

    A simple method allowing the preparation of 82 Br labelled organic bromine compounds from olefins with chemical and radiochemical yields between 75 and 95% and the specific activities required, is described [fr

  7. SYNTHESIS AND CHARACTERIZATION OF NEW HALOGENATED CURCUMINOIDS

    Directory of Open Access Journals (Sweden)

    Eugenio Torres

    2013-12-01

    Full Text Available In this work a novel procedure of synthesis of compounds analogues to curcumin with halogens atoms in its structure is described, which can increase its solubility and biological activity. Four halogenated curcuminoids were obtained with great pharmacological interest, none of them reported in literature before. Synthesis was carried out by means of the aldol condensation assisted by microwaves of halogenated aromatic aldehydes and acetylacetona, using morpholine as basic catalyst, in absence of solvent, and the reaction just needed 1 min. The products were purified by treatment of the reaction mixture with methanol under ultrasound irradiation, followed by chromatographic column. All obtained compounds were characterized by infrared spectroscopy, nuclear magnetic resonance, quantitative elementary analysis and high resolution mass spectrometry. The RMN-1H data demonstrate in all structures of synthesized curcuminoids the enol form is the most favored.

  8. Treating contaminated organic compounds using the DETOX process

    International Nuclear Information System (INIS)

    Elsberry, K.; Dhooge, P.M.

    1993-01-01

    Waste matrices containing organic compounds, radionuclides, and metals pose difficult problems in waste treatment and disposal when the organic compounds and/or metals are considered to be hazardous. This paper describes the results of bench-scale studies of DETOX applied to the components of liquid mixed wastes, with the goal of establishing parameters for designing a prototype waste treatment unit. Apparent reaction rate orders for organic compounds and the dependence of apparent reaction rate on solution composition and the contact area were measured for vacuum pump oil, scintillation fluids, and trichloroethylene. Reaction rate was superior in chloride-based solutions and was proportional to the contact area above about 20 g/kg loading of organic material. Oxidations in 4-L volume, mixed bench-top reactor have given destruction efficiencies of 0.999999+ g/g for common organic compounds. Reaction rates achieved in the mixed bench-top reactor were one to two orders of magnitude greater than had been achieved in unmixed reactions; a thoroughly mixed reactor should be capable of oxidizing 10 to 100+ g of organic material per L-hr. Results are also presented on the solvation efficiency of DETOX for mercury, cerium, and neodymium, and for removal/destruction of organic compounds sorbed on vermiculite. The next stage of development will be converting the bench-top unit to continuous processing

  9. Evolution of interstellar organic compounds under asteroidal hydrothermal conditions

    Science.gov (United States)

    Vinogradoff, V.; Bernard, S.; Le Guillou, C.; Remusat, L.

    2018-05-01

    Carbonaceous chondrites (CC) contain a diversity of organic compounds. No definitive evidence for a genetic relationship between these complex organic molecules and the simple organic molecules detected in the interstellar medium (ISM) has yet been reported. One of the many difficulties arises from the transformations of organic compounds during accretion and hydrothermal alteration on asteroids. Here, we report results of hydrothermal alteration experiments conducted on a common constituent of interstellar ice analogs, Hexamethylenetetramine (HMT - C6H12N4). We submitted HMT to asteroidal hydrothermal conditions at 150 °C, for various durations (up to 31 days) and under alkaline pH. Organic products were characterized by gas chromatography mass spectrometry, infrared spectroscopy and synchrotron-based X-ray absorption near edge structure spectroscopy. Results show that, within a few days, HMT has evolved into (1) a very diverse suite of soluble compounds dominated by N-bearing aromatic compounds (> 150 species after 31 days), including for instance formamide, pyridine, pyrrole and their polymers (2) an aromatic and N-rich insoluble material that forms after only 7 days of experiment and then remains stable through time. The reaction pathways leading to the soluble compounds likely include HMT dissociation, formose and Maillard-type reactions, e.g. reactions of sugar derivatives with amines. The present study demonstrates that, if interstellar organic compounds such as HMT had been accreted by chondrite parent bodies, they would have undergone chemical transformations during hydrothermal alteration, potentially leading to the formation of high molecular weight insoluble organic molecules. Some of the diversity of soluble and insoluble organic compounds found in CC may thus result from asteroidal hydrothermal alteration.

  10. Trace organic compounds in wet atmospheric deposition: an overview

    Science.gov (United States)

    Steinheimer, T.R.; Johnson, S.M.

    1987-01-01

    An overview of the occurrence of organic compounds in wet atmospheric deposition is given. Multiplicity of sources and problems associated with source identification are discussed. Available literature is reviewed by using citations from Chemical Abstracts and Water Resources Abstracts through June 1985 and includes reports published through December 1984 that summarize current knowledge. Approaches to the chemical determination of organic compounds in precipitation are examined in addition to aspects of sampling protocols. Best methods for sample collection and preparation for instrumental analysis continue to be discussed among various investigators. Automatic wet-deposition-only devices for collection and extraction are preferred. Classes of organic compounds that have been identified in precipitation include a spectrum of compounds with differing properties of acidity or basicity, polarity, and water solubility. Those compounds that have been reported in rainfall, snowfall, and ice include hydrocarbons (both aromatic and nonaromatic), chlorinated derivatives of these hydrocarbons, carbonyl compounds (both acidic and nonacidic), and carboxylic acids and esters. Formic and acetic are the most abundant organic acids present. Cloudwater, fogwater, and mist also have been collected and analyzed for organic composition.

  11. Direct or photostimulated luminescence after X-Ray irradiation of divalent europium in alkaline earth compounds containing some halides; Luminescence directe ou photostimulee apres irradiation X de l'europium divalent dans des familles de composes alcalino-terreux comportant un halogene

    Energy Technology Data Exchange (ETDEWEB)

    Merigou, C

    1990-10-15

    With a view for digitizing of radiological images, the luminescent properties of divalent europium in diverse halogen compounds involving strontium or barium have been studied. In halogen-rich compounds (MCl{sub 2}, M{sub 4}OCl{sub 6}, M{sub 5}SiO{sub 4}Cl{sub 6},... where M is Sr or Ba), the thermal extinction of the emission begins only above 300 K. High densities of coloured spots have been produced with X-ray irradiation. The combining of these 2 features has led to the obtention of high yields for argon laser stimulated luminescence in the case of Sr{sub 5}SiO{sub 4}Cl{sub 5}Br:Eu halogen silicate. Although these yields are high they stay below that of BaXF:Eu which is usually used in photon-stimulated screens.

  12. Investigation of second-order hyperpolarizability of some organic compounds

    Science.gov (United States)

    Tajalli, H.; Zirak, P.; Ahmadi, S.

    2003-04-01

    In this work, we have measured the second order hyperpolarizability of some organic materials with (EFISH) method and also calculated the second order hyperpolarizability of 13 organic compound with Mopac6 software and investigated the different factors that affect the amount of second order hyperpolarizability and ways to increase it.

  13. Thin films of metal-organic compounds and metal nanoparticle

    Indian Academy of Sciences (India)

    Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications. S Philip Anthony Shatabdi Porel D ... Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which ...

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

    Science.gov (United States)

    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 ...

  15. Removal of organic compounds from shale gas flowback water

    NARCIS (Netherlands)

    Butkovskyi, Andrii; Faber, Ann-Hélène; Wang, Yue; Grolle, Katja; Hofman-Caris, Roberta; Bruning, Harry; Van Wezel, Annemarie P.; Rijnaarts, Huub H M

    2018-01-01

    Ozonation, sorption to granular activated carbon and aerobic degradation were compared as potential treatment methods for removal of dissolved organic carbon (DOC) fractions and selected organic compounds from shale gas flowback water after pre-treatment in dissolved air flotation unit. Flowback

  16. On the enrichment of hydrophobic organic compounds in fog droplets

    Science.gov (United States)

    Valsaraj, K. T.; Thoma, G. J.; Reible, D. D.; Thibodeaux, L. J.

    The unusual degree of enrichment of hydrophobic organics in fogwater droplets reported by several investigators can be interpreted as a result of (a) the effects of temperature correction on the reported enrichment factors, (b) the effects of colloidal organic matter (both filterable and non-filterable) in fog water and (c) the effects of the large air-water interfacial adsorption of neutral hydrophobic organics on the tiny fog droplets. The enrichment factor was directly correlated to the hydrophobicity (or the activity coefficient in water) of the compounds, as indicated by their octanol-water partition constants. Compounds with large octanol-water partition coefficients (high activity coefficients in water) showed the largest enrichment. Available experimental data on the adsorption of hydrophobic compounds at the air-water interface and on colloidal organic carbon were used to show that the large specific air-water interfacial areas of fog droplets contribute significantly to the enrichment factor.

  17. Studies about behavior of microbial degradation of organic compounds

    International Nuclear Information System (INIS)

    Ohtsuka, Makiko

    2003-02-01

    Some of TRU waste include organic compounds, thus these organic compounds might be nutrients for microbial growth at disposal site. This disposal system might be exposed to high alkali condition by cement compounds as engineering barrier material. In the former experimental studies, it has been supposed that microbial exist under pH = 12 and the microbial activity acclimated to high alkali condition are able to degrade asphalt under anaerobic condition. Microbes are called extremophile that exist in cruel habitat as high alkali or reductive condition. We know less information about the activity of extremophile, though any recent studies reveal them. In this study, the first investigation is metabolic pathway as microbial activity, the second is microbial degradation of aromatic compounds in anaerobic condition, and the third is microbial activity under high alkali. Microbial metabolic pathway consist of two systems that fulfill their function each other. One system is to generate energy for microbial activities and the other is to convert substances for syntheses of organisms' structure materials. As these systems are based on redox reaction between substances, it is made chart of the microbial activity region using pH, Eh, and depth as parameter, There is much report that microbe is able to degrade aromatic compounds under aerobic or molecular O 2 utilizing condition. For degradation of aromatic compounds in anaerobic condition, supplying electron acceptor is required. Co-metabolism and microbial consortia has important role, too. Alcalophile has individual transporting system depending Na + and acidic compounds contained in cell wall. Generating energy is key for survival and growth under high alkali condition. Co-metabolism and microbial consortia are effective for microbial degradation of aromatic compounds under high alkali and reductive condition, and utilizable electron acceptor and degradable organic compounds are required for keeping microbial activity and

  18. Levels of Organic Compounds, Number of Microorganisms

    Science.gov (United States)

    Majewska, Małgorzata; Słomka, Anna

    2016-01-01

    Understanding the microbiological, biochemical and physiological aspects of phytoremediation of soil and water environments polluted to different degrees with heavy metals has very important theoretical and practical implications. In this study, a comparison was made between total cadmium concentration in root and shoot tissues as well as concentrations of particular fractions of Cd immobilized by roots of Festuca ovina (Sheep’s fescue) hydroponically cultivated in nutrient solutions supplemented with 1 μg Cd ml(–1) and those cultivated at 10 μg Cd ml(–1). After three weeks of F. ovina cultivation, the number of bacterial CFU and the amounts of organic chelators, siderophores, proteins and reducing sugars in the growth medium and on the root surface were higher at 10 than at 1 μg Cd ml(–1). The grass also reacted to the high Cd concentration by a decrease in plant growth and dehydrogenase activity in root tissues. The concentration of Cd determined in fractions bound with different strength in roots was significantly dependent on Cd concentration in the growth medium. When the plants were grown at 1 μg Cd ml(–1), 9% of the immobilized cadmium was loosely bound to the root surface, 20% was exchangeable adsorbed, and 28% was bound by chelation; at 10 μg Cd ml(–1), the respective values were 12%, 25%, and 20%. About 43% of the immobilized cadmium remained in roots after sequential extraction, and bioaccumulation factors in shoots had the same values independently of Cd concentration. At both Cd concentrations, the cadmium translocation index for F. ovina was low (< 1), which is why this grass can be recommended for phytostabilization of the metal under study.

  19. Improving rubber concrete by waste organic sulfur compounds.

    Science.gov (United States)

    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.

  20. Halogenation of Hydraulic Fracturing Additives in the Shale Well Parameter Space

    Science.gov (United States)

    Sumner, A. J.; Plata, D.

    2017-12-01

    Horizontal Drilling and Hydraulic fracturing (HDHF) involves the deep-well injection of a `fracking fluid' composed of diverse and numerous chemical additives designed to facilitate the release and collection of natural gas from shale plays. The potential impacts of HDHF operations on water resources and ecosystems are numerous, and analyses of flowback samples revealed organic compounds from both geogenic and anthropogenic sources. Furthermore, halogenated chemicals were also detected, and these compounds are rarely disclosed, suggesting the in situ halogenation of reactive additives. To test this transformation hypothesis, we designed and operated a novel high pressure and temperature reactor system to simulate the shale well parameter space and investigate the chemical reactivity of twelve commonly disclosed and functionally diverse HDHF additives. Early results revealed an unanticipated halogenation pathway of α-β unsaturated aldehyde, Cinnamaldehyde, in the presence of oxidant and concentrated brine. Ongoing experiments over a range of parameters informed a proposed mechanism, demonstrating the role of various shale-well specific parameters in enabling the demonstrated halogenation pathway. Ultimately, these results will inform a host of potentially unintended interactions of HDHF additives during the extreme conditions down-bore of a shale well during HDHF activities.

  1. Surface microlayer enrichment of volatile organic compounds and semi-volatile organic compounds in drinking water source.

    Science.gov (United States)

    Huang, Zhi; Zhou, Wen; Yu, Ya-juan; Zhang, Ai-qian; Han, Shuo-kui; Wang, Lian-sheng

    2004-01-01

    Enrichment of volatile organic compounds(VOC) and semi-volatility organic compounds(SVOC) in surface microlayer(SM) of three drinking water sources were studied. The enrichment factor(EFs) were 0.67 to 13.37 and 0.16 to 136, respectively. The results showed some VOC and most SVOC could enrich in SM. Some EFs of SVOC was quite high. Suspension and temperature could affect EFs of SVOC, slim wind and water movement do not destroy enrichment of organic in SM.

  2. Biokinetics and dosimetry of radioactively labelled organic C-14 compounds

    International Nuclear Information System (INIS)

    Krins, A.; Sahre, P.; Schoenmuth, T.

    2003-12-01

    The report starts with summarising research work and the resulting scientific information in connection with the dosimetry of C-14 labelled organic compounds. Biokinetic models are developed for compounds such as benzene, phenol, aniline, nitrobenzene, and a selection of pharmaceuticals, in order to show the radioactivity distribution after administration of the C-14 labelled substances. Based on the those models, dose coefficients and excretion rates are derived. The following synoptic view of the available data library leads on to a discussion of various aspects, as eg. the question of whether and how monitoring for detection of incorporation of C-14 administered with labelled organic compounds is possible. None of the questions and aspects arising in connection with this subject can be adequately dealt with in the present document, but concepts and methods are presented which permit an interpretation of radioactivity excretion data measured after incorporation of C-14 labelled organic substances. (orig./CB) [de

  3. Radiolytic formation of organic iodides from organic compounds released from ripolin paint

    International Nuclear Information System (INIS)

    Attia, S.; Evans, G.J.

    2002-01-01

    The impact of a serious nuclear reactor accident is governed to a large extent by the possible release of airborne organic iodides to the environment. This research examines the identification and behavior of organic iodides formed in the containment due to the release of organic compounds from Ripolin paint, into the aqueous phase, following a nuclear reactor accident. A bench scale apparatus installed in the irradiation chamber of a Gammacell was used to analyze the formation of organic iodides. Iodo-organics, transferred to the gas phase above irradiated aqueous samples, were analyzed using a Thermal Desorption method coupled with gas chromatography and mass spectrometry. Detailed studies of the identity of the organic compounds released and the organic iodides formed were conducted. The effects of parameters such as irradiation dose were also examined. All the organic iodides formed, under radiolytic conditions, were identified as iodo-alkanes. The organic compounds that were released from the Ripolin paint, such as methyl isobutyl ketone, were found to decompose, by a series of reactions, to produce the organic iodides. The precursor organic compounds and the organic iodides formed were observed to consist of the same alkyl group. These results indicate that organic compounds released from surface paints directly influence the formation of radiolytic organic iodide. (author)

  4. Inventory of volatile organic compound emissions in Finland, 1985

    International Nuclear Information System (INIS)

    Mroueh, U.M.

    1988-01-01

    The aim of the study was to compile an inventory of the emissions of volatile organic compounds in Finland for the year 1985. The report was prepared for the ECE Task Force on Emissions of Volatile Organic Compounds from Stationary Sources according to the classification given by the Task Force. It considers anthropogenic as well as natural sources. Mobile sources are excluded. The quantities as well as the main components are listed, as far as possible. The values given exclude methane which according to the present understanding is regarded as unreactive

  5. Simplified Production of Organic Compounds Containing High Enantiomer Excesses

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Froste, H [comp.

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Froste, H. [comp.

    1996-12-31

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

  8. Organic compounds inhibiting S. epidermidis adhesion and biofilm formation

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhiqiang [Department of Systems Biology, Technical University of Denmark, Dk-2800 Kgs. Lyngby (Denmark); Key Laboratory of Medical Molecular Virology of Ministry of Education and Public Health, Institute of Medical Microbiology and Institutes of Biomedical Science, Shanghai Medical School of Fudan University, Yi Xue Yuan Road 138, Shanghai 200032 (China); Division of Infectious Diseases, Department of Medicine, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas Street, Charleston, SC 29425 (United States); Zhang, Jingdong; Hu, Yifan; Chi, Qijin [Department of Chemistry, Building 207, NanoDTU, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Mortensen, Ninell P. [Department of Systems Biology, Technical University of Denmark, Dk-2800 Kgs. Lyngby (Denmark); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37932 (United States); Qu, Di [Key Laboratory of Medical Molecular Virology of Ministry of Education and Public Health, Institute of Medical Microbiology and Institutes of Biomedical Science, Shanghai Medical School of Fudan University, Yi Xue Yuan Road 138, Shanghai 200032 (China); Molin, Soren [Department of Systems Biology, Technical University of Denmark, Dk-2800 Kgs. Lyngby (Denmark); Ulstrup, Jens, E-mail: ju@kemi.dtu.dk [Department of Chemistry, Building 207, NanoDTU, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2009-07-15

    The formation of biofilms on surfaces of indwelling medical devices is a serious medical problem. Staphylococcus epidermidis is a common pathogen found to colonize implanted devices and as a biofilm is more resistant to the host immune system as well as to antibiotic treatments. Combating S. epidermidis infections by preventing or eradicating biofilm formation of the bacterium is therefore a medically important challenge. We report here a study of biofilm formation of S. epidermidis on solid surfaces using a combination of confocal laser scanning (CLSM) and atomic force microscopy (AFM) in both air and aqueous environments. We have investigated the inhibitory effects of surfaces treated with four organic compounds, two benzoate derivatives denoted as compound 59 and 75 and two carboxamide derivatives denoted as compound 47 and 73, on S. epidermidis adhesion and biofilm formation. All four compounds evoke significant inhibitory effects on the formation of S. epidermidis biofilms with compounds 47 and 73 being most effective. None of the compounds were found to inhibit growth of S. epidermidis in liquid cultures. Bacteria attached to the substrate when exposed to the compounds were not affected indicating that these compounds inhibit initial adhesion. These results suggest a pretreatment for medically implanted surfaces that can prevent the biofilm formation and reduce infection.

  9. Organic compounds inhibiting S. epidermidis adhesion and biofilm formation

    International Nuclear Information System (INIS)

    Qin, Zhiqiang; Zhang, Jingdong; Hu, Yifan; Chi, Qijin; Mortensen, Ninell P.; Qu, Di; Molin, Soren; Ulstrup, Jens

    2009-01-01

    The formation of biofilms on surfaces of indwelling medical devices is a serious medical problem. Staphylococcus epidermidis is a common pathogen found to colonize implanted devices and as a biofilm is more resistant to the host immune system as well as to antibiotic treatments. Combating S. epidermidis infections by preventing or eradicating biofilm formation of the bacterium is therefore a medically important challenge. We report here a study of biofilm formation of S. epidermidis on solid surfaces using a combination of confocal laser scanning (CLSM) and atomic force microscopy (AFM) in both air and aqueous environments. We have investigated the inhibitory effects of surfaces treated with four organic compounds, two benzoate derivatives denoted as compound 59 and 75 and two carboxamide derivatives denoted as compound 47 and 73, on S. epidermidis adhesion and biofilm formation. All four compounds evoke significant inhibitory effects on the formation of S. epidermidis biofilms with compounds 47 and 73 being most effective. None of the compounds were found to inhibit growth of S. epidermidis in liquid cultures. Bacteria attached to the substrate when exposed to the compounds were not affected indicating that these compounds inhibit initial adhesion. These results suggest a pretreatment for medically implanted surfaces that can prevent the biofilm formation and reduce infection.

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

    Science.gov (United States)

    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. Greatly enhanced flux pinning properties of fluorine-free metal-organic decomposition YBCO films by co-addition of halogens (Cl, Br) and metals (Zr, Sn, Hf)

    Science.gov (United States)

    Motoki, Takanori; Ikeda, Shuhei; Nakamura, Shin-ichi; Honda, Genki; Nagaishi, Tatsuoki; Doi, Toshiya; Shimoyama, Jun-ichi

    2018-04-01

    Additive-free YBCO films, as well as those with halogen (X) added, metal (M) added and (X, M) co-added, have been prepared by the fluorine-free metal-organic decomposition method on SrTiO3(100) single crystalline substrates, where X = Cl, Br and M = Zr, Sn, Hf. It was revealed that the addition of both Cl and Br to the starting solution resulted in the generation of oxyhalide, Ba2Cu3O4 X 2, in the YBCO films, and that the oxyhalide was found to promote the bi-axial orientation of the YBCO crystals. By adding a decent amount of Cl or Br, highly textured YBCO films with high J c were reproducibly obtained, even when an impurity metal, M, was co-added, while the addition of M without X did not greatly improve J c owing to the poor bi-axial orientation of the YBCO crystals. Our results suggest that the addition of Br more effectively enhances J c than the addition of Cl. The pinning force density at 40 K in 4.8 T reached ˜55 GN m-3 with the co-addition of (Br, M). This value is much larger than that of the pure YBCO film, reaching ˜17 GN m-3.

  12. Phosphate incorporation in organic compounds in roots of maize

    Energy Technology Data Exchange (ETDEWEB)

    Michalik, I; Ivanko, S [Vysoka Skola Polnohospodarska, Nitra (Czechoslovakia)

    1976-01-01

    /sup 32/P incorporation and metabolism was investigated for short exposure times of 1 sec, 10 sec and 1, 10, 30 and 120 min. By stepwise extraction with a methanol-chloroform-formic acid-water mixture, various fractions of P compounds were obtained. Low-molecular acid-soluble P compounds were separated by one-dimensional paper chromatography. Of the total amount of /sup 32/P absorbed by the roots of maize in the form of phosphate ions during the short incubation time of 1 sec, more than 33% was incorporated into organic compounds. With increasing incubation time, the proportion of /sup 32/P in low-molecular organic compounds increased with the decreasing proportion of inorganic phosphorus. In the 1 sec, exposure incorporation was found in 3 low-molecular organic compounds only, namely ATP, ADP and diphosphoglyceric acid. The /sup 32/P incorporation into ATP and ADP, in contrast with incorporation into diphosphoglyceric acid, increased markedly with increased exposure time.

  13. Ambient volatile organic compounds (VOCs) in Calgary, Alberta: Sources and screening health risk assessment.

    Science.gov (United States)

    Bari, Md Aynul; Kindzierski, Warren B

    2018-08-01

    Exposure to ambient volatile organic compound (VOCs) in urban areas is of interest because of their potential chronic and acute adverse effects to public health. Limited information is available about VOC sources in urban areas in Canada. An investigation of ambient VOCs levels, their potential sources and associated risks to public health was undertaken for the urban core of Alberta's largest city (downtown Calgary) for the period 2010-2015. Twenty-four hour arithmetic and geometric mean concentrations of total VOCs were 42μg/m 3 and 39μg/m 3 , respectively and ranged from 16 to 160μg/m 3 , with winter levels about two-fold higher than summer. Alkanes (58%) were the most dominant compounds followed by halogenated VOCs (22%) and aromatics (11%). Mean and maximum 24h ambient concentrations of selected VOCs of public health concern were below chronic and acute health risk screening criteria of the United States regulatory agencies and a cancer screening benchmark used in Alberta equivalent to 1 in 100,000 lifetime risk. The Positive matrix factorization (PMF) model revealed nine VOC sources at downtown Calgary, where oil/natural gas extraction/combustion (26%), fuel combustion (20%), traffic sources including gasoline exhaust, diesel exhaust, mixed fugitive emissions (10-15%), and industrial coatings/solvents (12%) were predominant. Other sources included dry cleaning (3.3%), biogenic (3.5%) and a background source (18%). Source-specific health risk values were also estimated. Estimated cancer risks for all sources were below the Alberta cancer screening benchmark, and estimated non-cancer risks for all sources were well below a safe level. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Biogenic volatile organic compounds in the Earth system.

    Science.gov (United States)

    Laothawornkitkul, Jullada; Taylor, Jane E; Paul, Nigel D; Hewitt, C Nicholas

    2009-01-01

    Biogenic volatile organic compounds produced by plants are involved in plant growth, development, reproduction and defence. They also function as communication media within plant communities, between plants and between plants and insects. Because of the high chemical reactivity of many of these compounds, coupled with their large mass emission rates from vegetation into the atmosphere, they have significant effects on the chemical composition and physical characteristics of the atmosphere. Hence, biogenic volatile organic compounds mediate the relationship between the biosphere and the atmosphere. Alteration of this relationship by anthropogenically driven changes to the environment, including global climate change, may perturb these interactions and may lead to adverse and hard-to-predict consequences for the Earth system.

  15. Novel collection method for volatile organic compounds (VOCs) from dogs

    Science.gov (United States)

    Host derived chemical cues are an important aspect of arthropod attraction to potential hosts. Host cues that act over longer distances include CO2, heat, and water vapor, while cues such as volatile organic compounds (VOCs) act over closer distances. Domestic dogs are important hosts for disease cy...

  16. Exposure to organic compounds during heat treatment of cooking oils

    Directory of Open Access Journals (Sweden)

    Marzena Zaciera

    2012-09-01

    Full Text Available Fumes from cooking oils were found to be genotoxic in several short-term tests. Epidemiological research among Taiwanese and Chinese women has shown high incidence of lung cancer. These women were not smoking or rarely smoking , but they cooked meals every day. A lot of organic compounds have been identified from cooking oils including PAH.

  17. 40 CFR 60.542 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after the date on which the initial performance test, required by § 60.8, is completed, but no later than...

  18. Determination of hydrogen isotope composition in organic compounds

    International Nuclear Information System (INIS)

    Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.; Tarielashvili, V.O.

    1989-01-01

    method for determination of hydrogen isotope composition just in organic compounds using mass-spectrometer of the second class is suggested. The method enables to determine atomic fraction of hydrogen without multiplet separation. The accuracy of determination of deuterium atomic fraction in acetone in 1-99% range was equal to 3-0.2% respectively

  19. Nitrosonium complexes of organic compounds. Structure and reactivity

    International Nuclear Information System (INIS)

    Borodkin, Gennady I; Shubin, Vyacheslav G

    2001-01-01

    Data on the structures and reactivities of nitrosonium complexes of organic compounds are systematised and generalised. The characteristic features of the electronic structure of the NO + cation are responsible for a wide structural variety of nitrosonium complexes. Reactions of nitrosonium complexes are described. The bibliography includes 172 references.

  20. Radiation-induced nitration of organic compounds in aqueous solutions

    International Nuclear Information System (INIS)

    Ershov, B.G.; Gordeev, A.V.; Bykov, G.L.

    2009-01-01

    Radiation-induced nitration of organic compounds in aqueous solutions was studied. It was found that γ-irradiation of solutions containing acetic and nitric acid and/or their salts gives nitromethane. Dependences of the product yield on the absorbed dose and the contents of components were established. The mechanism of radiation nitration involving radicals is discussed. (author)

  1. The growth of bacteria on organic compounds in drinking water

    NARCIS (Netherlands)

    Kooij, van der D.

    1984-01-01

    Growth ("regrowth") of bacteria In drinking water distribution systems results in a deterioration of the water quality. Regrowth of chemoheterotrophic bacteria depends on the presence of organic. compounds that serve as a nutrient source for these bacteria. A batch-culture technique was

  2. ambient volatile organic compounds pollution and ozone formation

    African Journals Online (AJOL)

    OLUMAYEDE

    2013-08-01

    Aug 1, 2013 ... Volatile organic compound (VOC) species react at different rate and exhibit differences in reactivity with respect to ozone formation in polluted urban atmosphere. To assess this, the variations pattern, reactivity relative to OH radical and ozone creation potential of ambient VOCs were investigated in field.

  3. Green chemistry principles in organic compound synthesis and analysis

    Directory of Open Access Journals (Sweden)

    Ruchi Verma

    2014-03-01

    Full Text Available The present review focus on various green chemistry approaches which could be utilized in the organic compounds in practical classes for undergraduate level in comparison of conventional methods. These methods avoid the usage of hazardous substances and are environmental friendly.

  4. Instrument for Analysis of Organic Compounds on Other Planets

    Science.gov (United States)

    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.

  5. Preparation of radioactive labelled compounds. Pt. 2. 82Br labelled organic bromine compounds by isotopic exchange

    International Nuclear Information System (INIS)

    Otto, R.

    1988-05-01

    Studies on isotopic exchange between organic bromine compounds and 82 Br labelled dioxane dibromide in the presence of AlCl 3 are described. The results obtained enable to develop a simple and quick preparation method for the labelling with 82 Br [fr

  6. Charge-density matching in organic-inorganic uranyl compounds

    International Nuclear Information System (INIS)

    Krivovichev, S.V.; Krivovichev, S.V.; Tananaev, I.G.; Myasoedov, B.F.

    2007-01-01

    Single crystals of [C 10 H 26 N 2 ][(UO 2 )(SeO 4 ) 2 (H 2 O)](H 2 SeO 4 ) 0.85 (H 2 O) 2 (1), [C 10 H 26 N 2 ][(UO 2 )(SeO 4 ) 2 ] (H 2 SeO 4 ) 0.50 (H 2 O) (2), and [C 8 H 20 N] 2 [(UO 2 )(SeO 4 ) 2 (H 2 O)] (H 2 O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in pentagonal bipyramidal and tetrahedral coordinations, respectively. The UO 7 and SeO 4 polyhedra polymerize by sharing common O atoms to form chains (compound 1) or sheets (compounds 2 and 3). In the structure of 1, the layers consisting of hydrogen-bonded [UO 2 (SeO 4 ) 2 (H 2 O)] 2- chains are separated by mixed organic-inorganic layers comprising from [NH 3 (CH 2 ) 10 NH 3 ] 2+ molecules, H 2 O molecules, and disordered electroneutral (H 2 SeO 4 ) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO 2 (SeO 4 ) 2 ] 2- sheet. The structure of 3 does not contain disordered (H 2 SeO 4 ) groups but is based upon alternating [UO 2 (SeO 4 ) 2 (H 2 O)] 2- sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH 3 (CH 2 ) 7 CH 3 ] + . The structures may be considered as composed of anionic inorganic sheets (2D blocks) and cationic organic blocks self-organized according to competing hydrophilic-hydrophobic interactions. Analysis of the structures allows us to conclude that the charge-density matching principle is observed in uranyl compounds. In order to satisfy some basic peculiarities of uranyl (in general, actinyl) chemistry, it requires specific additional mechanisms: (a) in long-chain-amine-templated compounds, protonated amine molecules inter-digitate; (b) in long-chain-diamine-templated compounds, incorporation of acid-water interlayers into

  7. Determination of organic compounds in water using ultraviolet LED

    Science.gov (United States)

    Kim, Chihoon; Ji, Taeksoo; Eom, Joo Beom

    2018-04-01

    This paper describes a method of detecting organic compounds in water using an ultraviolet LED (280 nm) spectroscopy system and a photodetector. The LED spectroscopy system showed a high correlation between the concentration of the prepared potassium hydrogen phthalate and that calculated by multiple linear regression, indicating an adjusted coefficient of determination ranging from 0.953-0.993. In addition, a comparison between the performance of the spectroscopy system and the total organic carbon analyzer indicated that the difference in concentration was small. Based on the close correlation between the spectroscopy and photodetector absorbance values, organic measurement with a photodetector could be configured for monitoring.

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

    Directory of Open Access Journals (Sweden)

    Ivan Milovanović

    2015-01-01

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

  9. Characterization of halogenated DBPs and identification of new DBPs trihalomethanols in chlorine dioxide treated drinking water with multiple extractions.

    Science.gov (United States)

    Han, Jiarui; Zhang, Xiangru; Liu, Jiaqi; Zhu, Xiaohu; Gong, Tingting

    2017-08-01

    Chlorine dioxide (ClO 2 ) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and haloacetic acids. A major portion of total organic halogen (TOX), a collective parameter for all halogenated DBPs, formed in ClO 2 -treated drinking water is still unknown. A commonly used pretreatment method for analyzing halogenated DBPs in drinking water is one-time liquid-liquid extraction (LLE), which may lead to a substantial loss of DBPs prior to analysis. In this study, characterization and identification of polar halogenated DBPs in a ClO 2 -treated drinking water sample were conducted by pretreating the sample with multiple extractions. Compared to one-time LLE, the combined four-time LLEs improved the recovery of TOX by 2.3 times. The developmental toxicity of the drinking water sample pretreated with the combined four-time LLEs was 1.67 times higher than that pretreated with one-time LLE. With the aid of ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, a new group of polar halogenated DBPs, trihalomethanols, were detected in the drinking water sample pretreated with multiple extractions; two of them, trichloromethanol and bromodichloromethanol, were identified with synthesized standard compounds. Moreover, these trihalomethanols were found to be the transformation products of trihalomethanes formed during ClO 2 disinfection. The results indicate that multiple LLEs can significantly improve extraction efficiencies of polar halogenated DBPs and is a better pretreatment method for characterizing and identifying new polar halogenated DBPs in drinking water. Copyright © 2017. Published by Elsevier B.V.

  10. Sorption of Heterocyclic Organic Compounds to Multiwalled Carbon Nanotubes.

    Science.gov (United States)

    Metzelder, Florian; Funck, Matin; Schmidt, Torsten C

    2018-01-16

    Sorption is an important natural and technical process. Sorption coefficients are typically determined in batch experiments, but this may be challenging for weakly sorbing compounds. An alternative method enabling analysis of those compounds is column chromatography. A column packed with the sorbent is used and sorption data are determined by relating sorbate retention to that of a nonretarded tracer. In this study, column chromatography was applied for the first time to study sorption of previously hardly investigated heterocyclic organic compounds to multiwalled carbon nanotubes (MWCNTs). Sorption data for these compounds are very limited in literature, and weak sorption is expected from predictions. Deuterium oxide was used as nonretarded tracer. Sorption isotherms were well described by the Freundlich model and data showed reasonable agreement with predicted values. Sorption was exothermic and physisorption was observed. H-bonding may contribute to overall sorption, which is supported by reduced sorption with increasing ionic strength due to blocking of functional groups. Lowering pH reduced sorption of ionizable compounds, due to electrostatic repulsion at pH 3 where sorbent as well as sorbates were positively charged. Overall, column chromatography was successfully used to study sorption of heterocyclic compounds to MWCNTs and could be applied for other carbon-based sorbents.

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

    Science.gov (United States)

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

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

  12. Main regularities of radiolytic transformations of bifunctional organic compounds

    International Nuclear Information System (INIS)

    Petryaev, E.P.; Shadyro, O.I.

    1985-01-01

    General regularities of the radiolysis of bifunctional organic compounds (α-diols, ethers of α-diols, amino alcohols, hydroxy aldehydes and hydroxy asids) in aqueous solutions from the early stages of the process to formation of finite products are traced. It is pointed out that the most characteristic course of radiation-chemical, transformation of bifunctional compounds in agueous solutions in the fragmentation process with monomolecular decomposition of primary radicals of initial substrances and simultaneous scission of two vicinal in respect to radical centre bonds via five-membered cyclic transient state. The data obtained are of importance for molecular radiobiology

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

    NARCIS (Netherlands)

    Kotterman, M.J.J.; Veen, van der I.; Hesselingen, van J.M.; Leonards, P.E.G.; Osinga, R.; Boer, de J.

    2003-01-01

    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

  14. Holographic detection of hydrocarbon gases and other volatile organic compounds.

    Science.gov (United States)

    Martínez-Hurtado, J L; Davidson, C A B; Blyth, J; Lowe, C R

    2010-10-05

    There is a need to develop sensors for real-time monitoring of volatile organic compounds (VOCs) and hydrocarbon gases in both external and indoor environments, since these compounds are of growing concern in human health and welfare. Current measurement technology for VOCs requires sophisticated equipment and lacks the prospect for rapid real-time monitoring. Holographic sensors can give a direct reading of the analyte concentration as a color change. We report a technique for recording holographic sensors by laser ablation of silver particles formed in situ by diffusion. This technique allows a readily available hydrophobic silicone elastomer to be transformed into an effective sensor for hydrocarbon gases and other volatile compounds. The intermolecular interactions present between the polymer and molecules are used to predict the sensor performance. The hydrophobicity of this material allows the sensor to operate without interference from water and other atmospheric gases and thus makes the sensor suitable for biomedical, industrial, or environmental analysis.

  15. Organic compounds inhibiting S. epidermidis adhesion and biofilm formation

    DEFF Research Database (Denmark)

    Qin, Zhiqiang; Zhang, Jingdong; Hu, Yifan

    2009-01-01

    The formation of biofilms on surfaces of indwelling medical devices is a serious medical problem. Staphylococcus epidermidis is a common pathogen found to colonize implanted devices and as a biofilm is more resistant to the host immune system as well as to antibiotic treatments. Combating S....... epidermidis infections by preventing or eradicating biofilm formation of the bacterium is therefore a medically important challenge. We report here a study of biofilm formation of S. epidermidis on solid surfaces using a combination of confocal laser scanning (CLSM) and atomic force microscopy (AFM) in both...... air and aqueous environments. We have investigated the inhibitory effects of surfaces treated with four organic compounds, two benzoate derivatives denoted as compound 59 and 75 and two carboxamicle derivatives denoted as compound 47 and 73, on S. epidermidis adhesion and biofilm formation. All four...

  16. Release of organic nitrogen compounds from Kerogen via catalytic hydropyrolysis

    Directory of Open Access Journals (Sweden)

    Bennett B

    2000-12-01

    Full Text Available High hydrogen pressure pyrolysis (hydropyrolysis was performed on samples of solvent extracted Kimmeridge Clay Formation source rock with a maturity equivalent to ca. 0.35% vitrinite reflectance. We describe the types and distributions of organic nitrogen compounds in the pyrolysis products (hydropyrolysates using GC-MS. Compounds identified included alkyl-substituted indoles, carbazoles, benzocarbazoles, quinolines and benzoquinolines. The distributions of the isomers of methylcarbazoles, C2-alkylcarbazoles and benzocarbazoles in the hydropyrolysates were compared to a typical North Sea oil. The hydropyrolysates compared to the North Sea oil, showed increased contributions from alkylcarbazole isomers where the nitrogen group is "exposed" (no alkyl substituents adjacent to the nitrogen functionality and appreciable levels of benzo[b]carbazole relative to benzo[a]- and benzo[c]carbazoles. Hydropyrolysis is found to be an ideal technique for liberating appreciable quantities of heterocyclic organic nitrogen compounds from geomacromolecules. The products released from the immature Kimmeridge Clay are thought to represent a potential source of nitrogen compounds in the bound phase (kerogen able to contribute to the free bitumen phase during catagenesis.

  17. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

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

    1995-01-01

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

  18. Beyond the network of plants volatile organic compounds

    OpenAIRE

    Vivaldo, Gianna; Masi, Elisa; Taiti, Cosimo; Caldarelli, Guido; Mancuso, Stefano

    2017-01-01

    Plants emission of volatile organic compounds (VOCs) is involved in a wide class of ecological functions, as VOCs play a crucial role in plants interactions with biotic and abiotic factors. Accordingly, they vary widely across species and underpin differences in ecological strategy. In this paper, VOCs spontaneously emitted by 109 plant species (belonging to 56 different families) have been qualitatively and quantitatively analysed in order to classify plants species. By using bipartite netwo...

  19. Production of fungal volatile organic compounds in bedding materials

    Directory of Open Access Journals (Sweden)

    S. LAPPALAINEN

    2008-12-01

    Full Text Available The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin and analysed by gas chromatography. Several microbial volatile organic compounds (MVOCs, e.g. 1-butanol, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol and 1-octanol were detected in laboratory experiments; however, these accounted for only 0.08-1.5% of total volatile organic com-pounds (TVOCs. Emission rates of MVOCs were 0.001-0.176 mg/kg of bedding materials per hour. Despite some limitations of the analytical method, certain individual MVOCs, 2-hexanone, 2-hep-tanone and 3-octanone, were also detected in concentrations of less than 4.6 mg/m 3 (0.07-0.31% of TVOC in a horse stable where peat and shavings were used as bedding materials. MVOC emission rate was estimated to be 0.2-2.0 mg/kg ´ h -1 from bedding materials in the stable, being about ten times higher than the rates found in the laboratory experiments. Some compounds, e.g. 3-octanone and 1-octen-3-ol, can be assumed to originate mainly from microbial metabolisms.;

  20. Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

    Science.gov (United States)

    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.

  1. Production of fungal volatile organic compounds in bedding materials

    OpenAIRE

    S. LAPPALAINEN; A. PASANEN; P. PASANEN

    2008-01-01

    The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin a...

  2. Incineration method for plutonium recovery from alpha contaminated organic compounds

    International Nuclear Information System (INIS)

    Yahata, Taneaki; Abe, Jiro; Kato, Michiharu; Kurihara, Masayoshi

    1985-01-01

    An incineration method for plutonium recovery from α contaminated organic compounds in a flow of controlled oxygen gas is stated. The species of such thermal decomposition products as hydrocarbons, free carbon, carbon monoxide and hydrogen were determined by mass spectrography. The mixture of the products which are the source of tar or soot was converted to CO 2 and H 2 O in contact with copper oxide catalyst without flaming. This incineration method is composed of two stages. The first stage is the decomposition of organic compounds in the streams of gas mixtures containing oxygen in low ratios. The second stage is the incineration of the decomposition products by catalytic reaction in the streams of gas with higher oxygen ratios. Plutonium was recovered as the form of plutonium dioxide from the incineration residues of the first stage. The behavior of oil was examined as a representative of liquid organic compounds. It was found to evaporate below ca. 500 0 C, but was completely incinerated by the catalytic reaction with copper oxide catalyst in the flow of gas with controlled oxygen amount and was changed to CO 2 and H 2 O. (author)

  3. Engineering biosynthesis of high-value compounds in photosynthetic organisms.

    Science.gov (United States)

    O'Neill, Ellis C; Kelly, Steven

    2017-09-01

    The photosynthetic, autotrophic lifestyle of plants and algae position them as ideal platform organisms for sustainable production of biomolecules. However, their use in industrial biotechnology is limited in comparison to heterotrophic organisms, such as bacteria and yeast. This usage gap is in part due to the challenges in generating genetically modified plants and algae and in part due to the difficulty in the development of synthetic biology tools for manipulating gene expression in these systems. Plant and algal metabolism, pre-installed with multiple biosynthetic modules for precursor compounds, bypasses the requirement to install these pathways in conventional production organisms, and creates new opportunities for the industrial production of complex molecules. This review provides a broad overview of the successes, challenges and future prospects for genetic engineering in plants and algae for enhanced or de novo production of biomolecules. The toolbox of technologies and strategies that have been used to engineer metabolism are discussed, and the potential use of engineered plants for industrial manufacturing of large quantities of high-value compounds is explored. This review also discusses the routes that have been taken to modify the profiles of primary metabolites for increasing the nutritional quality of foods as well as the production of specialized metabolites, cosmetics, pharmaceuticals and industrial chemicals. As the universe of high-value biosynthetic pathways continues to expand, and the tools to engineer these pathways continue to develop, it is likely plants and algae will become increasingly valuable for the biomanufacturing of high-value compounds.

  4. Biodegradation of volatile organic compounds by five fungal species

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-01

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

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

    International Nuclear Information System (INIS)

    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 4 ) contamination located near the center of the Hanford Site. The movement of CCl 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

  6. Assessment of indoor levels of volatile organic compounds and carbon dioxide in schools in Kuwait.

    Science.gov (United States)

    Al-Awadi, Layla

    2018-01-01

    Indoor air quality (IAQ) in schools is a matter of concern because children are most vulnerable and sensitive to pollutant exposure. Conservation of energy at the expense of ventilation in heating, ventilation, and air conditioning (HVAC) systems adversely affects IAQ. Extensive use of new materials in building, fitting, and refurbishing emit various pollutants such that the indoor environment creates its own discomfort and health risks. Various schools in Kuwait were selected to assess their IAQ. Comprehensive measurements of volatile organic compounds (VOCs) consisting of 72 organic compounds consisting of aliphatic (C 3 -C 6 ), aromatic (C 6 -C 9 ), halogenated (C 1 -C 7 ), and oxygenated (C 2 -C 9 ) functional groups in indoor air were made for the first time in schools in Kuwait. The concentrations of indoor air pollutants revealed hot spots (science preparation rooms, science laboratories, arts and crafts classes/paint rooms, and woodworking shops/decoration rooms where local sources contributed to the buildup of pollutants in each school. The most abundant VOC pollutant was chlorodifluoromethane (R22; ClF 2 CH), which leaked from air conditioning (AC) systems due to improper operation and maintenance. The other copious VOCs were alcohols and acetone at different locations due to improper handling of the chemicals and their excessive uses as solvents. Indoor carbon dioxide (CO 2 ) levels were measured, and these levels reflected the performance of HVAC systems; a specific rate or lack of ventilation affected the IAQ. Recommendations are proposed to mitigate the buildup of indoor air pollutants at school sites. Indoor air quality in elementary schools has been a subject of extreme importance due to susceptibility and sensibility of children to air pollutants. The schools were selected based on their surrounding environment especially downwind direction from the highly industrialized zone in Kuwait. Extensive sampling from different sites in four schools for

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

    Science.gov (United States)

    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

  8. Microbial degradation of water-insoluble organic compounds

    International Nuclear Information System (INIS)

    Thomas, J.M.

    1985-01-01

    The effect of solubilization on biodegradation of water-insoluble organic compounds was investigated. The effect of particle size on solubilization and degradation of 4-chlorobiphenyl (4-CB) and naphthalene by a microbial mixture was determined. The concentration of soluble compound was determined using gas-liquid chromatography. The rates of solubilization were inversely related to particle size for both compounds. The rates of mineralization of 14 C-labeled palmitic acid, octadecane, di(2-ethylhexyl)phthalate (DEHP), and Sevin (1-naphthyl N-methylcarbamate) by microbial mixtures were determined by trapping the 14 CO 2 formed, and those rates were compared to solubilization rates determined by periodically filtering sterile MS amended with one of the compounds. Mineralization and colonization of the surface of 10 μg palmitic acid per 10 ml MS by Pseudomonas pseudoflava was determined by trapping 14 CO 2 and epifluorescence microscopy. Mineralization began before colonization and was initially exponential, but the rate then declined. The rate of mineralization at the end of the exponential phase approximated the rate of solubilization. The surface was completely covered about the time mineralization stopped. Unbound cells grew exponentially before colonization was detected; however, colonization of the surface was complete after the number of free cells stopped increasing. The data suggest that soluble palmitic acid is utilized before the insoluble phase but colonization is important in the mineralization of palmitic acid when solubilization becomes rate limiting

  9. Some methods for labelling organic compounds by deuterium

    International Nuclear Information System (INIS)

    Moustapha, C.

    1988-01-01

    The rapid growth of knowledge in the fields of biochemistry, physiology, and molecular biology reflects to a considerable degree the utilization of stable isotopes (specially deuterium) in the study of chemical reactions and fragmentation mechanisms in mass spectrometry, as well as in the pharmacological and biological studies. Organic compounds maybe labelled by deuterium through classic organic reactions by using special deuterated solvents and reagents. This article discusses some reactions, with examples on how to prepare labelled compounds with high isotopic purety. These reactions are: exchange reactions in acid and alkaline media (the exchange in the chromatographic column in liquid and gas phases, the exchange in homogenous medium), reduction reactions of functional groups as well as saturation of the double bounds by deuterium using hydrogenation catalystes, electrochemical reactions using KOLBE, and photochemical reactions. This article also deals with spectroscopic properties of deuterium and the methods which are used to identify its compounds such as infrared, nuclear magnetic resonance, and mass spectroscopy. 37 refs., 2 figs

  10. Advanced Characterization of Semivolatile Organic Compounds Emitted from Biomass Burning

    Science.gov (United States)

    Hatch, L. E.; Liu, Y.; Rivas-Ubach, A.; Shaw, J. B.; Lipton, M. S.; Barsanti, K. C.

    2017-12-01

    Biomass burning (BB) emits large amounts of non-methane organic gases (NMOGs) and primary (directly emitted) particulate matter (PM). NMOGs also react in plume to form secondary PM (i.e., SOA) and ozone. BB-PM has been difficult to represent accurately in models used for chemistry and climate predictions, including for air quality and fire management purposes. Much recent research supports that many previously unconsidered SOA precursors exist, including oxidation of semivolatile compounds (SVOCs). Although many recent studies have characterized relatively volatile BB-derived NMOGs and relatively non-volatile particle-phase organic species, comparatively few studies have performed detailed characterization of SVOCs emitted from BB. Here we present efforts to expand the volatility and compositional ranges of compounds measured in BB smoke. In this work, samples of SVOCs in gas and particle phases were collected from 18 fires representing a range of fuel types during the 2016 FIREX fire laboratory campaign; samples were analyzed by two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS) and Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS). Hundreds of compounds were detectable in both gas and particle phases by GCxGC-TOFMS whereas thousands of peaks were present in the FTICR mass spectra. Data from both approaches highlight that chemical fingerprints of smoke are fuel/burn-dependent. These efforts support our continued research in building the understanding and model representation of BB emissions and BB-derived SOA.

  11. Effects of organic compounds on actinoid transfer in natural environment

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Keizo; Nakaguchi, Yuzuru; Suzuki, Yasuhiro [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology; Senoo, Muneaki; Nagao, Seiya; Sakamoto, Yoshiaki

    1996-01-01

    For safety evaluation of geological disposal of radioactive wastes, it seems necessary to elucidate the geological transfer of radioactive nuclides in the soil and the undersea sediments. It has been known that there exist various organic compounds highly potential to form a complex with TRU elements, uranium, copper etc. in the soil and the sediments and those compounds may play an important role for geological transfer of nuclides. In this study, fluorescent substances contained in underground and river water were focused as the measures to identify the molecular species of organic compounds in natural water and their interactions with radionuclides and minor metals, and their geological transfers were investigated. Spectrophotometric properties of humic acid obtained in the market were examined. Its fluorescent intensity was strongest at pH 10 and stable for 2 weeks or more. Then, highly polluted river water was taken from Yamato river to determine the contents of humic acid and other fluorescent substances. Further, the effects of the additions of Cu and Fe on the fluorescent intensity were examined. (M.N.)

  12. Charge-density matching in organic-inorganic uranyl compounds

    Energy Technology Data Exchange (ETDEWEB)

    Krivovichev, S.V. [Saint Petersburg State Univ., Dept. of Crystallography, Faculty of Geology (Russian Federation); Krivovichev, S.V.; Tananaev, I.G.; Myasoedov, B.F. [Russian Academy of Sciences, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow (Russian Federation)

    2007-10-15

    Single crystals of [C{sub 10}H{sub 26}N{sub 2}][(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)](H{sub 2}SeO{sub 4}){sub 0.85}(H{sub 2}O){sub 2} (1), [C{sub 10}H{sub 26}N{sub 2}][(UO{sub 2})(SeO{sub 4}){sub 2}] (H{sub 2}SeO{sub 4}){sub 0.50}(H{sub 2}O) (2), and [C{sub 8}H{sub 20}N]{sub 2}[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)] (H{sub 2}O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in pentagonal bipyramidal and tetrahedral coordinations, respectively. The UO{sub 7} and SeO{sub 4} polyhedra polymerize by sharing common O atoms to form chains (compound 1) or sheets (compounds 2 and 3). In the structure of 1, the layers consisting of hydrogen-bonded [UO{sub 2}(SeO{sub 4}){sub 2}(H{sub 2}O)]{sup 2-} chains are separated by mixed organic-inorganic layers comprising from [NH{sub 3}(CH{sub 2}){sub 10}NH{sub 3}]{sup 2+} molecules, H{sub 2}O molecules, and disordered electroneutral (H{sub 2}SeO{sub 4}) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO{sub 2}(SeO{sub 4}){sub 2}]{sup 2-} sheet. The structure of 3 does not contain disordered (H{sub 2}SeO{sub 4}) groups but is based upon alternating [UO{sub 2}(SeO{sub 4}){sub 2}(H{sub 2}O)]{sup 2-} sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH{sub 3}(CH{sub 2}){sub 7}CH{sub 3}]{sup +}. The structures may be considered as composed of anionic inorganic sheets (2D blocks) and cationic organic blocks self-organized according to competing hydrophilic-hydrophobic interactions. Analysis of the structures allows us to conclude that the charge-density matching principle is observed in uranyl compounds. In order to satisfy some basic peculiarities of uranyl (in

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2018-01-01

    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.

  15. Interaction between t-butyl hydroperoxide (I) and positive halogen compounds. part I. Intermediates in the reaction between I and CI2O

    NARCIS (Netherlands)

    Ham, J. van; Schors, A.; Kooyman, E.C.

    1973-01-01

    “positive halogen” compounds were found to induce the decomposition of t-butyl hydroperoxide (I) in the dark. In this Cl2O proved to be particularly effective, liberating oxygen from I instantaneously at 0°. At temperature between −80° and −30°, two oxygen-rich intermediates could be observed with

  16. Symmetric and asymmetric halogen-containing metallocarboranylporphyrins and uses thereof

    Science.gov (United States)

    Miura, Michiko; Wu, Haitao

    2013-05-21

    The present invention is directed to low toxicity boronated compounds and methods for their use in the treatment, visualization, and diagnosis of tumors. More specifically, the present invention is directed to low toxicity halogenated, carborane-containing 5,10,15,20-tetraphenylporphyrin compounds and methods for their use particularly in boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) for the treatment of tumors of the brain, head and neck, and surrounding tissue. The invention is also directed to using these halogenated, carborane-containing tetraphenylporphyrin compounds in methods of tumor imaging and/or diagnosis such as MRI, SPECT, or PET.

  17. Tropospheric Halogen Chemistry

    Science.gov (United States)

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing the main oxidants O3 and its photolysis product OH and directly, e.g., by reactions of the Cl radical with hydrocarbons (e.g., CH4).Already by the middle of the nineteenth century, Marchand (1852) reported the presence of bromine and iodine in rain and other natural waters. He also mentions the benefits of iodine in drinking water through the prevention of goitres and cretinism. In a prophetic monograph "Air and Rain: The Beginnings of a Chemical Climatology," Smith (1872) describes measurements of chloride in rain water, which he states to originate partly from the oceans by a process that he compares with the bursting of "soap bubbles" which produces "small vehicles" that transfer small spray droplets of seawater to the air. From deviations of the sulfate-to-chloride ratio in coastal rain compared to seawater, Smith concluded that chemical processes occur once the particles are airborne.For almost a century thereafter, however, atmospheric halogens received little attention. One exception was the work by Cauer (1939), who reported that iodine pollution has been significant in Western and Central Europe due to the inefficient burning of seaweed, causing mean gas phase atmospheric concentrations as high as or greater than 0.5 μg m-3. In his classical textbook Air Chemistry and Radioactivity, Junge (1963) devoted less than three pages to halogen gas phase chemistry, discussing chlorine and iodine. As reviewed by Eriksson (1959a, b), the main atmospheric source of halogens is sea salt, derived from the bursting of bubbles of air which are produced by ocean waves and other

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

  20. Electron beam treatment of toxic volatile organic compounds and dioxins

    International Nuclear Information System (INIS)

    Kojima, Takuji

    2006-01-01

    Considerations of wastes based on the reduction, reuse and recycle in daily life are primary measures to conserve our environment, but the control technology is necessary to support these measures. The electron beam (EB) process is promising as an advanced purification process having advantages such as a quick treatment of big volume gas, applicability even for very low concentration pollutants as the further purification at the downstream of existing process, and decomposition of pollutants into non-toxic substances by one process. The EB technology has been developed for treatment of toxic volatile organic compounds (VOCs) in ventilation gas and dioxins in solid waste incineration flue gas. (author)

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

    Directory of Open Access Journals (Sweden)

    Milena Šetka

    2017-03-01

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

  2. A box model study on photochemical interactions between VOCs and reactive halogen species in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2004-01-01

    Full Text Available A new chemical scheme is developed for the multiphase photochemical box model SEAMAC (size-SEgregated Aerosol model for Marine Air Chemistry to investigate photochemical interactions between volatile organic compounds (VOCs and reactive halogen species in the marine boundary layer (MBL. Based primarily on critically evaluated kinetic and photochemical rate parameters as well as a protocol for chemical mechanism development, the new scheme has achieved a near-explicit description of oxidative degradation of up to C3-hydrocarbons (CH4, C2H6, C3H8, C2H4, C3H6, and C2H2 initiated by reactions with OH radicals, Cl- and Br-atoms, and O3. Rate constants and product yields for reactions involving halogen species are taken from the literature where available, but the majority of them need to be estimated. In particular, addition reactions of halogen atoms with alkenes will result in forming halogenated organic intermediates, whose photochemical loss rates are carefully evaluated in the present work. Model calculations with the new chemical scheme reveal that the oceanic emissions of acetaldehyde (CH3CHO and alkenes (especially C3H6 are important factors for regulating reactive halogen chemistry in the MBL by promoting the conversion of Br atoms into HBr or more stable brominated intermediates in the organic form. The latter include brominated hydroperoxides, bromoacetaldehyde, and bromoacetone, which sequester bromine from a reactive inorganic pool. The total mixing ratio of brominated organic species thus produced is likely to reach 10-20% or more of that of inorganic gaseous bromine species over wide regions over the ocean. The reaction between Br atoms and C2H2 is shown to be unimportant for determining the degree of bromine activation in the remote MBL. These results imply that reactive halogen chemistry can mediate a link between the oceanic emissions of VOCs and the behaviors of compounds that are sensitive to halogen chemistry such as dimethyl

  3. Spatial arrangement of organic compounds on a model mineral surface: implications for soil organic matter stabilization.

    Science.gov (United States)

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

    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.

  4. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    , emitted in order to communicate within and between trophic levels and as protection against biotic and abiotic stresses, or as byproducts. Some BVOCs are very reactive, and when entering the atmosphere they rapidly react with for example hydroxyl radicals and ozone, affecting the oxidative capacity......Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...

  5. Dynamic behavior of semivolatile organic compounds in indoor air

    Energy Technology Data Exchange (ETDEWEB)

    Loy, Michael David Van [Univ. of California, Berkeley, CA (United States)

    1998-12-09

    Exposures to a wide range of air pollutants are often dominated by those occurring in buildings because of three factors: 1) most people spend a large fraction of their time indoors, 2) many pollutants have strong indoor sources, and 3) the dilution volume in buildings is generally several orders of magnitude smaller than that of an urban airshed. Semivolatile organic compounds (SVOCS) are emitted by numerous indoor sources, including tobacco combustion, cooking, carpets, paints, resins, and glues, so indoor gasphase concentrations of these compounds are likely to be elevated relative to ambient levels. The rates of uptake and release of reversibly sorbing SVOCS by indoor materials directly affect both peak concentrations and persistence of the pollutants indoors after source elimination. Thus, accurate predictions of SVOC dynamics in indoor air require an understanding of contaminant sorption on surface materials such as carpet and wallboard. The dynamic behaviors of gas-phase nicotine and phenanthrene were investigated in a 20 ms stainless steel chamber containing carpet and painted wallboard. Each compound was studied independently, first in the empty chamber, then with each sorbent individually, and finally with both sorbents in the chamber.

  6. Emission and role of biogenic volatile organic compounds in biosphere

    International Nuclear Information System (INIS)

    Saleem, A.R.

    2013-01-01

    Plants are an essential part of the biosphere. Under the influence of climate change, plants respond in multiple ways within the ecosystem. One such way is the release of assimilated carbon back to the atmosphere in form of biogenic volatile organic compounds (BVOCs), which are produced by plants and are involved in plant growth, reproduction, defense and other . These compounds are emitted from vegetation into the atmosphere under different environmental situations. Plants produce an extensive range of BVOCs, including isoprenoids, sequisterpenes, aldehydes, alcohols and terpenes in different tissues above and below the ground. The emission rates vary with various environmental conditions and the plant growth stage in its life span.BVOCs are released under biotic and abiotic stress changes, like heat, drought, land-use changes, higher atmospheric CO concentrations, increased UV radiation and insect or disease attack. Plants emit BVOCs in atmosphere in order to avoid stress, and adapt to harsh circumstances. These compounds also have a significant role in plant-plant interaction, communication and competition. BVOCs have the ability to alter atmospheric chemistry; they readily react with atmospheric pollutant gases under high temperature and form tropospheric ozone, which is a potent air pollutant for global warming and disease occurrence. BVOCs may be a cause of photochemical smog and increase the stay of other GHGs in the atmosphere. Therefore, further study is required to assess the behavior of BVOCs in the biosphere as well as the atmosphere. (author)

  7. Identifying organic nitrogen compounds in Rocky Mountain National Park aerosols

    Science.gov (United States)

    Beem, K. B.; Desyaterik, Y.; Ozel, M. Z.; Hamilton, J. F.; Collett, J. L.

    2010-12-01

    Nitrogen deposition is an important issue in Rocky Mountain National Park (RMNP). While inorganic nitrogen contributions to the ecosystems in this area have been studied, the sources of organic nitrogen are still largely unknown. To better understand the potential sources of organic nitrogen, filter samples were collected and analyzed for organic nitrogen species. Samples were collected in RMNP using a Thermo Fisher Scientific TSP (total suspended particulate) high-volume sampler with a PM2.5 impactor plate from April - November of 2008. The samples presented the opportunity to compare two different methods for identification of individual organic nitrogen species. The first type of analysis was performed with a comprehensive two dimensional gas chromatography (GCxGC) system using a nitrogen chemiluminescence detector (NCD). The filter samples were spiked with propanil in dichloromethane to use as an internal standard and were then extracted in water followed by solid phase extraction. The GCxGC system was comprised of a volatility based separation (DB5 column) followed by a polarity based separation (RXI-17 column). A NCD was used to specifically detect nitrogen compounds and remove the complex background matrix. Individual standards were used to identify peaks by comparing retention times. This method has the added benefit of an equimolar response for nitrogen so only a single calibration is needed for all species. In the second analysis, a portion of the same filter samples were extracted in DI water and analyzed with liquid chromatography coupled with mass spectroscopy (LC/MS). The separation was performed using a C18 column and a water-methanol gradient elution. Electrospray ionization into a time of flight mass spectrometer was used for detection. High accuracy mass measurement allowed unambiguous assignments of elemental composition of resulting ions. Positive and negative polarities were used since amines tend to show up in positive mode and nitrates in

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

    Directory of Open Access Journals (Sweden)

    Ramjee Pallela

    2010-04-01

    Full Text Available 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.

  9. Formation of highly oxygenated organic molecules from aromatic compounds

    Science.gov (United States)

    Molteni, Ugo; Bianchi, Federico; Klein, Felix; El Haddad, Imad; Frege, Carla; Rossi, Michel J.; Dommen, Josef; Baltensperger, Urs

    2018-02-01

    Anthropogenic volatile organic compounds (AVOCs) often dominate the urban atmosphere and consist to a large degree of aromatic hydrocarbons (ArHCs), such as benzene, toluene, xylenes, and trimethylbenzenes, e.g., from the handling and combustion of fuels. These compounds are important precursors for the formation of secondary organic aerosol. Here we show that the oxidation of aromatics with OH leads to a subsequent autoxidation chain reaction forming highly oxygenated molecules (HOMs) with an O : C ratio of up to 1.09. This is exemplified for five single-ring ArHCs (benzene, toluene, o-/m-/p-xylene, mesitylene (1,3,5-trimethylbenzene) and ethylbenzene), as well as two conjugated polycyclic ArHCs (naphthalene and biphenyl). We report the elemental composition of the HOMs and show the differences in the oxidation patterns of these ArHCs. A potential pathway for the formation of these HOMs from aromatics is presented and discussed. We hypothesize that AVOCs may contribute substantially to new particle formation events that have been detected in urban areas.

  10. Formation of highly oxygenated organic molecules from aromatic compounds

    Directory of Open Access Journals (Sweden)

    U. Molteni

    2018-02-01

    Full Text Available Anthropogenic volatile organic compounds (AVOCs often dominate the urban atmosphere and consist to a large degree of aromatic hydrocarbons (ArHCs, such as benzene, toluene, xylenes, and trimethylbenzenes, e.g., from the handling and combustion of fuels. These compounds are important precursors for the formation of secondary organic aerosol. Here we show that the oxidation of aromatics with OH leads to a subsequent autoxidation chain reaction forming highly oxygenated molecules (HOMs with an O : C ratio of up to 1.09. This is exemplified for five single-ring ArHCs (benzene, toluene, o-/m-/p-xylene, mesitylene (1,3,5-trimethylbenzene and ethylbenzene, as well as two conjugated polycyclic ArHCs (naphthalene and biphenyl. We report the elemental composition of the HOMs and show the differences in the oxidation patterns of these ArHCs. A potential pathway for the formation of these HOMs from aromatics is presented and discussed. We hypothesize that AVOCs may contribute substantially to new particle formation events that have been detected in urban areas.

  11. Biogenic volatile organic compound emissions from vegetation fires.

    Science.gov (United States)

    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. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  12. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  13. GC-MS Study of Mono- and Bishaloethylphosphonates Related to Schedule 2.B.04 of the Chemical Weapons Convention: The Discovery of a New Intramolecular Halogen Transfer

    Science.gov (United States)

    Picazas-Márquez, Nerea; Sierra, María; Nova, Clara; Moreno, Juan Manuel; Aboitiz, Nuria; de Rivas, Gema; Sierra, Miguel A.; Martínez-Álvarez, Roberto; Gómez-Caballero, Esther

    2016-09-01

    A new class of compounds, mono- and bis-haloethylphosphonates (HAPs and bisHAPs, respectively), listed in Schedule 2.B.04 of the Chemical Weapons Convention (CWC), has been synthesized and studied by GC-MS with two aims. First, to improve the identification of this type of chemicals by the Organization for the Prohibition of Chemical Weapons, (OPCW). Second, to study the synergistic effect of halogen and silicon atoms in molecules undergoing mass spectrometry. Fragmentation patterns of trimethylsilyl derivatives of HAPs were found to depend on the nature of the halogen atom; this was in agreement with DFT-calculations. The data suggest that a novel intramolecular halogen transfer takes place during the fragmentation process.

  14. Electrocatalytic hydrogenation and hydrodeoxygenation of oxygenated and unsaturated organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, James E.; Lam, Chun Ho; Saffron, Christopher M.; Miller, Dennis J.

    2018-04-24

    A process and related electrode composition are disclosed for the electrocatalytic hydrogenation and/or hydrodeoxygenation of organic substrates such as biomass-derived bio-oil components by the production of hydrogen atoms on a catalyst surface followed by the reaction of the hydrogen atoms with the organic reactants. Biomass fast pyrolysis-derived bio-oil is a liquid mixture containing hundreds of organic compounds with chemical functionalities that are corrosive to container materials and are prone to polymerization. A high surface area skeletal metal catalyst material such as Raney Nickel can be used as the cathode. Electrocatalytic hydrogenation and/or hydrodeoxygenation convert the organic substrates under mild conditions to reduce coke formation and catalyst deactivation. The process converts oxygen-containing functionalities and unsaturated bonds into chemically reduced forms with an increased hydrogen content. The process is operated at mild conditions, which enables it to be a good means for stabilizing bio-oil to a form that can be stored and transported using metal containers and pipes.

  15. Volatile organic compound emissions from Larrea tridentata (creosotebush

    Directory of Open Access Journals (Sweden)

    A. Guenther

    2010-12-01

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

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

    Science.gov (United States)

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 d...

  17. Environmental levels and toxicological potencies of a novel mixed halogenated carbazole

    Directory of Open Access Journals (Sweden)

    Miren Pena-Abaurrea

    2016-09-01

    Full Text Available The present work involves an extensive analytical and toxicological description of a recently identified mixed halogenated carbazole found in sediment samples, 1,8-dibromo-3,6-dichloro-9H-carbazole (BCCZ. Concentrations and the relative effect potency (REP were calculated for the target BCCZ in a set of stream sediments collected in 2008 in Ontario, Canada. The levels calculated for BCCZ as compared to those previously assessed for legacy persistent organic pollutants (POPs in the same samples revealed a significant contribution of BCCZ to the total organic chemical contamination (<1%–95%; average 37%. The corresponding dioxin toxic equivalencies (TEQs of BCCZ in the sediment extracts were estimated from experimental REP data. The experimental data presented supports the classification of this emerging halogenated chemical as a contaminant of emerging environmental concern. Although potential emission sources could not be identified, this study highlights the importance of on-going research for complete characterization of halogenated carbazoles and related compounds.

  18. Energy dependence of radiation interaction parameters of some organic compounds

    Science.gov (United States)

    Singh, Mohinder; Tondon, Akash; Sandhu, B. S.; Singh, Bhajan

    2018-04-01

    Gamma rays interact with a material through photoelectric absorption, Compton scattering, Rayleigh scattering and Pair production in the intermediate energy range. The probability of occurrence of a particular type of process depends on the energy of incident gamma rays, atomic number of the material, scattering angle and geometrical conditions. Various radiological parameters for organic compounds, namely ethylene glycol (C2H6O2), propylene glycol (C3H8O2), glycerin (C3H8O3), isoamyl alcohol (C5H12O), butanone (C4H8O), acetophenone (C8H8O2), cyclohexanone (C6H10O), furfural (C5H4O2), benzaldehyde (C7H6O), cinnamaldehyde (C9H8O), glutaraldehyde (C5H8O2), aniline (C6H7N), benzyl amine (C6H7N), nitrobenzene (C6H5NO2), ethyl benzene (C8H10), ethyl formate (C3H6O2) and water (H2O) are presented at 81, 122, 356 and 511 keV energies employing NaI(Tl) scintillation detector in narrow-beam transmission geometry. The radiation interaction parameters such as mass attenuation, molar extinction and mass energy absorption coefficients, half value layer, total atomic and effective electronic cross-sections and CT number have been evaluated for these organic compounds. The general trend of values of mass attenuation coefficients, half value layer, molar extinction coefficients, total atomic and effective electronic cross-sections and mass energy absorption coefficients shows a decrease with increase in incident gamma photon energy. The values of CT number are found to increases linearly with increase of effective atomic number (Zeff). The variation in CT number around Zeff ≈ 3.3 shows the peak like structure with respect to water and the correlation between CT number and linear attenuation coefficient is about 0.99. Appropriate equations are fitted to these experimentally determined parameters for the organic compounds at incident photon energy ranging from 81 keV to 511 keV used in the present study. Experimental values are compared with the theoretical data obtained using Win

  19. Selection criteria for oxidation method in total organic carbon measurement.

    Science.gov (United States)

    Yoon, GeunSeok; Park, Sang-Min; Yang, Heuiwon; Tsang, Daniel C W; Alessi, Daniel S; Baek, Kitae

    2018-05-01

    During the measurement of total organic carbon (TOC), dissolved organic carbon is converted into CO 2 by using high temperature combustion (HTC) or wet chemical oxidation (WCO). However, the criteria for selecting the oxidation methods are not clear. In this study, the chemical structures of organic material were considered as a key factor to select the oxidation method used. Most non-degradable organic compounds showed a similar oxidation efficiency in both methods, including natural organic compounds, dyes, and pharmaceuticals, and thus both methods are appropriate to measure TOC in waters containing these compounds. However, only a fraction of the carbon in the halogenated compounds (perfluorooctanoic acid and trifluoroacetic acid) were oxidized using WCO, resulting in measured TOC values that are considerably lower than those determined by HTC. This result is likely due to the electronegativity of halogen elements which inhibits the approach of electron-rich sulfate radicals in the WCO, and the higher bond strength of carbon-halogen pairs as compared to carbon-hydrogen bonds, which results in a lower degree of oxidation of the compounds. Our results indicate that WCO could be used to oxidize most organic compounds, but may not be appropriate to quantify TOC in organic carbon pools that contain certain halogenated compounds. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Removal of gasoline volatile organic compounds via air biofiltration

    International Nuclear Information System (INIS)

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

    1995-01-01

    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 2 + H 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 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

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

    Science.gov (United States)

    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.

  2. Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly-Detected Halogenated Compounds: CFC-113a, CFC-112 and HCFC-133a

    Directory of Open Access Journals (Sweden)

    Maryam Etminan

    2014-07-01

    Full Text Available CFC-113a (CF3CCl3, CFC-112 (CFCl2CFCl2 and HCFC-133a (CF3CH2Cl are three newly detected molecules in the atmosphere that are almost certainly emitted as a result of human activity. It is important to characterise the possible contribution of these gases to radiative forcing of climate change and also to provide information on the CO2-equivalence of their emissions. We report new laboratory measurements of absorption cross-sections of these three compounds at a resolution of 0.01 cm−1 for two temperatures 250 K and 295 K in the spectral range of 600–1730 cm−1. These spectra are then used to calculate the radiative efficiencies and global warming potentials (GWP. The radiative efficiencies are found to be between 0.15 and 0.3 W∙m−2∙ppbv−1. The GWP for a 100 year time horizon, relative to carbon dioxide, ranges from 340 for the relatively short-lived HCFC-133a to 3840 for the longer-lived CFC-112. At current (2012 concentrations, these gases make a trivial contribution to total radiative forcing; however, the concentrations of CFC-113a and HCFC-133a are continuing to increase. The 2012 CO2-equivalent emissions, using the GWP (100, are estimated to be about 4% of the current global CO2-equivalent emissions of HFC-134a.

  3. Cytotoxic Compounds from Aerial Organs of Xanthium strumarium.

    Science.gov (United States)

    Ferrer, Janet Piloto; Zampini, Iris Catiana; Cuello, Ana Soledad; Francisco, Marbelis; Romero, Aylema; Valdivia, Dayana; Gonzalez, Maria; Carlos Salas; Lamar, Angel Sanchez; Isla, Maria Inés

    2016-03-01

    Xanthium strumarium L., the main species of the genus Xanthium, is ubiquitously distributed. The aim of this study was to determine the cytotoxic effect of aerial organs of X strumarium, grown in Cuba, against cancer cell lines and the isolation of compounds potentially responsible for this activity. Initially, an ethanol partitioning procedure yielded the XSE extract that was subsequently fractionated with chloroform resulting in a XSCF fraction. Both, XSE and XSCF fractions exhibited cytotoxic effects on MDA MB-23 1, MCF7, A549 and CT26 cell lines by using the MTT assay. Above all, the XSCF fraction was more active than XSE. For this reason, XSCF was subsequently fractionated by silica gel chromatography and the active fractions submitted to semi-preparative HPLC for isolation of bioactive compounds. Six sub-fractions (SF1 to SF6) were recovered. Sub-fractions 3 and 6 were the most active on each assayed cell line, while sub-fractions 4 and 5 were only active against A549 and CT26 cell lines. In each case, sub-fraction 6 showed the strongest inhibitory effect. The HPLC-DAD fingerprint of sub-fraction 6 showed a single peak that was identified by GC-MS as (-) spathulenol, a sesquiterpene with reported antitumor activity.

  4. Measurement of loss rates of organic compounds in snow using in situ experiments and isotopically labelled compounds

    Directory of Open Access Journals (Sweden)

    Erika von Schneidemesser

    2012-07-01

    Full Text Available Organic molecular marker compounds are widely used to identify emissions from anthropogenic and biogenic air pollution sources in atmospheric samples and in deposition. Specific organic compounds have been detected in polar regions, but their fate after deposition to snow is poorly characterized. Within this context, a series of exposure experiments were carried out to observe the post-depositional processing of organic compounds under real-world conditions in snow on the surface of the Greenland Ice Sheet, at the Summit research station. Snow was prepared from water spiked with isotopically labelled organic compounds, representative of typical molecular marker compounds emitted from anthropogenic activities. Reaction rate constants and reaction order were determined based on a decrease in concentration to a stable, non-zero, threshold concentration. Fluoranthene-d10, docosane-d46, hexadecanoic acid-d31, docosanoic acid-d43 and azelaic acid-d14 were estimated to have first order loss rates within surface snow with reaction rate constants of 0.068, 0.040, 0.070, 0.067 and 0.047 h−1, respectively. No loss of heptadecane-d36 was observed. Overall, these results suggest that organic contaminants are archived in polar snow, although significant post-depositional losses of specific organic compounds occur. This has implications for the environmental fate of organic contaminants, as well as for ice-core studies that seek to use organic molecular markers to infer past atmospheric loadings, and source emissions.

  5. Hybrid energy storage systems utilizing redox active organic compounds

    Science.gov (United States)

    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.

  6. Method for spiking soil samples with organic compounds

    DEFF Research Database (Denmark)

    Brinch, Ulla C; Ekelund, Flemming; Jacobsen, Carsten S

    2002-01-01

    We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either...... higher than in control soil, probably due mainly to release of predation from indigenous protozoa. In order to minimize solvent effects on indigenous soil microorganisms when spiking native soil samples with compounds having a low water solubility, we propose a common protocol in which the contaminant...... tagged with luxAB::Tn5. For both solvents, application to the whole sample resulted in severe side effects on both indigenous protozoa and bacteria. Application of dichloromethane to the whole soil volume immediately reduced the number of protozoa to below the detection limit. In one of the soils...

  7. Control of volatile organic compound emissions: the issues

    Energy Technology Data Exchange (ETDEWEB)

    Woodfield, M.; Marlowe, I.

    1989-11-01

    This review paper outlines the problems caused by the emissions of volatile organic compounds (VOC) which are causing increasing concern because of their part in the formation of photochemical oxidation that causes damage to crops and vegetation and because of the toxic and climatic effects. It briefly summarises current knowledge of VOC emissions and their effects and then suggests options for abatement of VOC emissions in the UK and the EEC. A comparison of anthropogenic VOC emission in the UK and the EEC from various sources is given. Further information is needed on current emissions, on the costs and efficiencies of control technologies and on the effects of control on industry before decisions can be made on the suitability, extent and strategy to control VOC emissions in the UK. The report was prepared for the UK Department of Trade and Industry (Headquarters).

  8. Effects of trace volatile organic compounds on methane oxidation

    Directory of Open Access Journals (Sweden)

    Chiemchaisri Wilai

    2001-01-01

    Full Text Available The effects of volatile organic compounds (VOCs on methane oxidation in landfill cover soils were examined. The batch experiments were conducted using single and mixed VOCs, such as, dichloromethane (DCM, trichloroethylene (TCE, tetrachloroethylene (PCE, and benzene. The results from all combinations showed a decrease in methane oxidation rate with increase in VOC concentrations. Moreover, inhibition effects of TCE and DCM were found higher than benzene and PCE. The reduction of methane oxidation by benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cell's internal membrane was found in a methanotrophic culture exposed to VOC gases which is the attachment site of a key enzyme needed for methane oxidation

  9. Imaging subsurface geology and volatile organic compound plumes

    International Nuclear Information System (INIS)

    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

  10. Investigation of michelson interferometer for volatile organic compound sensor

    International Nuclear Information System (INIS)

    Marzuarman; Rivai, Muhammad; Sardjono, Tri Arief; Purwanto, Djoko

    2017-01-01

    The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels. (paper)

  11. Emission of the main biogenic volatile organic compounds in France

    International Nuclear Information System (INIS)

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

    2000-01-01

    An estimation of biogenic emissions of the main non-methanic Volatile Organic Compounds (VOCs) due to the forest cover in France has been realized. 32 species representing 98% of French forest have been considered for the estimation. The latter dealt on a net made of 93 irregular spatial grids (Departments) with an average size of 75 km x 75 km. We assigned emission rates and foliar biomass densities specific to each of the 32 species. The environmental variables (temperature, light intensity) have been collected for the whole of French Departments. A special effort was extended so as to use ''Guenther's'' calculation algorithms, and specific emitting factors to species growing in France or in bordering countries. Along the way of the five years (1994-1998) of the study we have calculated the yearly mean of isoprene, mono-terpenes and Other Volatile Organic Compounds (OVOCs) emissions on the scale of the French Departments. At the national level isoprene emission is reckoned at 457 kt yr -1 and represents nearly 49% of the total emission, whereas mono-terpenes with 350 kt yr -1 and OVOCs with 129 kt yr -1 represent respectively 37% and 14% of the total. The yearly biogenic emission of VOCs in France represents virtually half the anthropic source. However in some regions (Mediterranean area) natural emissions can widely exceed anthropic emissions during certain periods. Let's note the whole of our results remains tinged with a great uncertainty because the estimations carried out are presented with correction factors that can reach values comprised between 4 and 7. (author)

  12. Treatment of trace organic compounds in common onsite wastewater systems

    Science.gov (United States)

    Robert Siegrist,; Conn, Kathleen E.

    2015-01-01

    Onsite wastewater systems (OWS) have historically been relied on to treat conventional pollutants and pathogens in a fashion similar to that expected from centralized wastewater systems. However, based on the occurrence of, and potential effects from, contaminants of emerging concern in wastewaters, OWS as well as centralized systems need to account for these compounds in system design and use. One group of contaminants involves organic compounds such as those associated with consumer product chemicals and pharmaceuticals, which are collectively referred to as trace organic compounds (TOrCs) due to their very low levels (e.g., ng/L to ug/L) relative to other pollutants. The question being confronted today is how best to account for TOrCs in onsite system design and use while also achieving other goals such as system simplicity, limited operation and maintenance requirements, low cost, and sustainability. In contrast to conventional pollutants such as nutrients and pathogens which have specific and achievable treatment goals, there are currently no enforceable treatment standards for TOrCs, which often have non-traditional toxicological endpoints (i.e. endocrine disruption). As highlighted in this paper, there are a large number of TOrCs that can be present in OWS and they have different properties, can be present at different frequencies of occurrence and concentrations, and have different susceptibilities to treatment in OWS. In general, based on the studies summarized in this paper, TOrCs normally should not require additional considerations beyond those for conventional pollutants and pathogens (e.g., nitrogen or bacteria and virus) during design and use of OWS. That said, there are situations where TOrCs could be a serious concern warranting special consideration in system design and use. In this paper, the frequency of occurrence of TOrCs and the range of concentrations encountered are highlighted. An evolving approach is outlined that could help assess the

  13. Neurotoxicity of fungal volatile organic compounds in Drosophila melanogaster.

    Science.gov (United States)

    Inamdar, Arati A; Masurekar, Prakash; Bennett, Joan Wennstrom

    2010-10-01

    Many volatile organic compounds (VOCs) are found in indoor environment as products of microbial metabolism. In damp indoor environments, fungi are associated with poor air quality. Some epidemiological studies have suggested that microbial VOCs have a negative impact on human health. Our study was designed to provide a reductionist approach toward studying fungal VOC-mediated toxicity using the inexpensive model organism, Drosophila melanogaster, and pure chemical standards of several important fungal VOCs. Low concentrations of the following known fungal VOCs, 0.1% of 1-octen-3-ol and 0.5% of 2-octanone; 2,5 dimethylfuran; 3-octanol; and trans-2-octenal, caused locomotory defects and changes in green fluorescent protein (GFP)- and antigen-labeled dopaminergic neurons in adult D. melanogaster. Locomotory defects could be partially rescued with L-DOPA. Ingestion of the antioxidant, vitamin E, improved the survival span and delayed the VOC-mediated changes in dopaminergic neurons, indicating that the VOC-mediated toxicity was due, in part, to generation of reactive oxygen species.

  14. Volatile Organic Compounds: Characteristics, distribution and sources in urban schools

    Science.gov (United States)

    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.

  15. Influence of Sensory Stimulation on Exhaled Volatile Organic Compounds.

    Science.gov (United States)

    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.

  16. Emerging site characterization technologies for volatile organic compounds

    International Nuclear Information System (INIS)

    Rohay, V.J.; Last, G.V.

    1992-05-01

    A Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) expedited response action (ERA) has been initiated at Hanford Site's 200 West Area for the removal of carbon tetrachloride from the unsaturated soils. In coordination with the ERA, innovative technology demonstrations are being conducted as part of DOE's Volatile Organic Compounds -- Arid Integrated Demonstration in an effort to improve upon baseline technologies. Improved methods for accessing, sampling, and analyzing soil and soil-vapor contaminants is a high priority. Sonic drilling is being evaluated as an alternative to cable-tool drilling, while still providing the advantages of reliability, containment, and waste minimization. Applied Research Associates, Inc. used their cone penetrometer in the 200 West Area to install a permanent soil-gas monitoring probe and to collect soil-gas profile data. However, successful application of this technology will require the development of an improved ability to penetrate coarse gravel units. A Science and Engineering Associates Membrane Instrumentation and Sampling Technique (SEAMIST) system designed for collecting in situ soil samples and air permeability data in between drilling runs at variable depths is being tested in 200 West Area boreholes. Analytical technologies scheduled for testing include supercritical fluid extraction and analysis for non- and semi-volatile organic co-contaminants and an unsaturated flow apparatus developed by Washington State University for the measurement of transport parameters

  17. Sources and Seasonality of Volatile Organic Compounds in the Northern Front Range Metropolitan Area

    Science.gov (United States)

    Abeleira, A.; Pollack, I. B.; Sive, B. C.; Zaragoza, J.; Lindaas, J.; Fischer, E. V.; Farmer, D.

    2016-12-01

    The Northern Front Range Metropolitan Area (NFRMA) of Colorado, with a growing population of over 3 million, was deemed an ozone (O3) nonattainment area (NAA) in 2008 despite continued work on NOx reductions. Ground-level O3 is produced from photochemical catalytic cycles initiated by the OH oxidation of volatile organic compounds (VOCs), and propagated through reactions involving peroxy (HO2+RO2) and NOx (NO + NO2) radicals. We measured a suite of speciated VOCs during two 8-week deployments (March-May 2015, July-September 2015) at the Boulder Atmospheric Observatory in Erie, CO. The spring deployment overlapped with the NOAA SONGNEX (Shale Oil and Natural Gas Nexus) campaign. The BAO site lies at an urban-rural interface in the NFRMA with multiple urban centers surrounding the site, a major interstate highway within 2 miles, local suburban development in Erie, agricultural operations in the surrounding counties, and recent rapid expansion of oil and gas development in adjacent Weld County. VOCs were measured hourly with a custom-built online gas chromatography system along with measurements of O3, NOx, PAN, CO, and CH4. VOC measurements included C2-C8 hydrocarbons (NMHCs), C1-C5 alkyl nitrates, C1-C2 halocarbons, and several oxygenated species (OVOCs: methyl ethyl ketone, acetone, acetaldehyde). Using Positive Matrix Factorization (PMF) we have identified four distinct VOC sources in the spring and five in the summer: 1) Oil and Natural Gas (ONG, e.g. C2 - C5 alkanes), 2) Traffic (e.g. ethyne & aromatics), 3) Background species (e.g. long-lived halogenated species), 4) Secondary production (e.g. C3-C5 alkyl nitrates & OVOCs), and for summer 5) Biogenic (e.g. isoprene). Using the source factors generated from the PMF analysis we calculated the VOC reactivity (VOCr) of each source. For both seasons, the ONG factor dominates VOCr in the mornings. In spring afternoons, a combination of background species and secondary products make up a large percentage of VOCr as

  18. A method to estimate the enthalpy of formation of organic compounds with chemical accuracy

    DEFF Research Database (Denmark)

    Hukkerikar, Amol; Meier, Robert J.; Sin, Gürkan

    2013-01-01

    through better correlation of data. For parameter estimation, a data-set containing 861 experimentally measured values of a wide variety of organic compounds (hydrocarbons, oxygenated compounds, nitrogenated compounds, multi-functional compounds, etc.) is used. The developed property model for Δf...

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

    Directory of Open Access Journals (Sweden)

    Tanzeela Khalid

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

  20. Attenuation of trace organic compounds (TOrCs) inbioelectrochemical systems

    KAUST Repository

    Werner, Craig M.

    2015-04-01

    Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4=-1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater

  1. Organohalide respiration in pristine environments: implications for the natural halogen cycle.

    Science.gov (United States)

    Atashgahi, Siavash; Häggblom, Max M; Smidt, Hauke

    2018-03-01

    Halogenated organic compounds, also termed organohalogens, were initially considered to be of almost exclusively anthropogenic origin. However, over 5000 naturally synthesized organohalogens are known today. This has also fuelled the hypothesis that the natural and ancient origin of organohalogens could have primed development of metabolic machineries for their degradation, especially in microorganisms. Among these, a special group of anaerobic microorganisms was discovered that could conserve energy by reducing organohalogens as terminal electron acceptor in a process termed organohalide respiration. Originally discovered in a quest for biodegradation of anthropogenic organohalogens, these organohalide-respiring bacteria (OHRB) were soon found to reside in pristine environments, such as the deep subseafloor and Arctic tundra soil with limited/no connections to anthropogenic activities. As such, accumulating evidence suggests an important role of OHRB in local natural halogen cycles, presumably taking advantage of natural organohalogens. In this minireview, we integrate current knowledge regarding the natural origin and occurrence of industrially important organohalogens and the evolution and spread of OHRB, and describe potential implications for natural halogen and carbon cycles. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Aqueous processing of organic compounds in carbonaceous asteroids

    Science.gov (United States)

    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

  3. Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

    Science.gov (United States)

    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.

  4. Secondary organic aerosol formation from a large number of reactive man-made organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Derwent, Richard G., E-mail: r.derwent@btopenworld.com [rdscientific, Newbury, Berkshire (United Kingdom); Jenkin, Michael E. [Atmospheric Chemistry Services, Okehampton, Devon (United Kingdom); Utembe, Steven R.; Shallcross, Dudley E. [School of Chemistry, University of Bristol, Bristol (United Kingdom); Murrells, Tim P.; Passant, Neil R. [AEA Environment and Energy, Harwell International Business Centre, Oxon (United Kingdom)

    2010-07-15

    A photochemical trajectory model has been used to examine the relative propensities of a wide variety of volatile organic compounds (VOCs) emitted by human activities to form secondary organic aerosol (SOA) under one set of highly idealised conditions representing northwest Europe. This study applied a detailed speciated VOC emission inventory and the Master Chemical Mechanism version 3.1 (MCM v3.1) gas phase chemistry, coupled with an optimised representation of gas-aerosol absorptive partitioning of 365 oxygenated chemical reaction product species. In all, SOA formation was estimated from the atmospheric oxidation of 113 emitted VOCs. A number of aromatic compounds, together with some alkanes and terpenes, showed significant propensities to form SOA. When these propensities were folded into a detailed speciated emission inventory, 15 organic compounds together accounted for 97% of the SOA formation potential of UK man made VOC emissions and 30 emission source categories accounted for 87% of this potential. After road transport and the chemical industry, SOA formation was dominated by the solvents sector which accounted for 28% of the SOA formation potential.

  5. Reactivity of group IV (100) semiconductor surfaces towards organic compounds

    Science.gov (United States)

    Wang, George T.

    The reactions of simple and multifunctional organic compounds with the clean silicon, germanium, and diamond (100)-2 x 1 semiconductor surfaces have been investigated using a combination of multiple internal reflection infrared spectroscopy and quantum chemistry density functional theory calculations. From these studies, an improved understanding of the atomic level reactivity of these semiconductor surfaces has been obtained, along with insights into how to achieve their selective coupling with organics of desired and varied functionality. In addition to the Si(100) and Ge(100) surfaces, our results show that cycloaddition chemistry can also be extended to the diamond (100) surface. At room temperature, 1,3-butadiene was found to form a Diels-Alder product with the diamond (100) surface, as evidenced by isotopic substitution experiments and comparison of the surface adduct with its direct molecular analogue, cyclohexene. The reactions of other classes of molecules in addition to alkenes on the Si(100) and Ge(100) surfaces, including a series of five-membered cyclic amines, were also examined. For tertiary aliphatic amines on Si(100) and both secondary and tertiary aliphatic amines on Ge(100), a majority of the molecules were observed to become stably trapped in dative-bonded precursor states rather than form energetically favorable dissociation products. For pyrrole, aromaticity was found to play a defining role in its reactivity, and a comparison of its molecular and surface reactivity reveals interesting similarities. To probe the factors controlling the selectivity of organic reactions on clean semiconductor surfaces, the adsorption of acetone and a series of unsaturated ketones was also investigated. The reaction of acetone on Ge(100) was found to be under thermodynamic control at room temperature, resulting in the formation of an "ene" product rather than the kinetically favored [2+2] C=O cycloaddition product previously observed on the Si(100) surface. In

  6. Calixarene Langmuir-Blodgett Thin Films For Volatile Organic Compounds

    International Nuclear Information System (INIS)

    Capan, R.

    2010-01-01

    Volatile Organic Compounds (VOC's) such as benzene, toluene, chloroform are chemicals that evaporate easily at room temperature and create many health effects on young children, elderly and a person with heightened sensitivity to chemicals. Concentrations of many VOC's are consistently higher indoors (up to ten times higher) than outdoors because many household products (for example paints, varnishes, many cleaning, disinfecting, cosmetic, degreasing, hobby products etc.) contains VOC's. Some effects of VOC's for human beings can be followed as the eye, nose, and throat irritations; headaches, loss of coordination, nausea; damage to liver, kidneys, and central nervous system. These are big incentives for the development of portable, user-friendly VOC's sensors and for the investigation of the sensing properties of new materials to be prepared as a thin film sensing element. Langmuir-Blodgett (LB) ultra-thin film technique allows us to produce monolayer or multilayer organic thin films that can be used as chemical sensing elements.In this work, materials known as the calix[n]arene are investigated for the production of sensing material against several VOC's such as the chloroform, benzene, ethylbenzene and toluene by using LB thin film techniques. UV-visible, Quartz Crystal Microbalance (QCM) system and Surface Plasmon Resonance (SPR) measurement techniques are used to check the quality of the deposition process onto a solid substrate. Surface morphology and sensing properties of the final sensing layers are then studied by Atomic Force Microscopy (AFM) and SPR techniques. Our results indicated that selected calixarene materials are sensitive enough and quite suitable to fabricate a highly ordered, reproducible and uniform LB film that can be used as a very thin sensing layer against VOC's.

  7. Volatile organic compounds at swine facilities: a critical review.

    Science.gov (United States)

    Ni, Ji-Qin; Robarge, Wayne P; Xiao, Changhe; Heber, Albert J

    2012-10-01

    Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions. Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples. The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts. Identification and quantification of VOCs were restricted by using instruments based on

  8. Non-microbial sources of microbial volatile organic compounds.

    Science.gov (United States)

    Choi, Hyunok; Schmidbauer, Norbert; Bornehag, Carl-Gustaf

    2016-07-01

    The question regarding the true sources of the purported microbial volatile organic compounds (MVOCs) remains unanswered. To identify microbial, as well as non-microbial sources of 28 compounds, which are commonly accepted as microbial VOCs (i.e. primary outcome of interest is Σ 28 VOCs). In a cross-sectional investigation of 390 homes, six building inspectors assessed water/mold damage, took air and dust samples, and measured environmental conditions (i.e., absolute humidity (AH, g/m(3)), temperature (°C), ventilation rate (ACH)). The air sample was analyzed for volatile organic compounds (μg/m(3)) and; dust samples were analyzed for total viable fungal concentration (CFU/g) and six phthalates (mg/g dust). Four benchmark variables of the underlying sources were defined as highest quartile categories of: 1) the total concentration of 17 propylene glycol and propylene glycol ethers (Σ17 PGEs) in the air sample; 2) 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MIB) in the air sample; 3) semi-quantitative mold index; and 4) total fungal load (CFU/g). Within severely damp homes, co-occurrence of the highest quartile concentration of either Σ17 PGEs or TMPD-MIB were respectively associated with a significantly higher median concentration of Σ 28 VOCs (8.05 and 13.38μg/m(3), respectively) compared to the reference homes (4.30 and 4.86μg/m(3), respectively, both Ps ≤0.002). Furthermore, the homes within the highest quartile range for Σ fungal load as well as AH were associated with a significantly increased median Σ 28 VOCs compared to the reference group (8.74 vs. 4.32μg/m(3), P=0.001). Within the final model of multiple indoor sources on Σ 28 VOCs, one natural log-unit increase in summed concentration of Σ17 PGEs, plus TMPD-MIB (Σ 17 PGEs + TMPD-MIB) was associated with 1.8-times (95% CI, 1.3-2.5), greater likelihood of having a highest quartile of Σ 28 VOCs, after adjusting for absolute humidity, history of repainting at least one room

  9. Biogenic volatile organic compound (VOC) emissions from forests in Finland

    International Nuclear Information System (INIS)

    Lindfors, V.; Laurila, T.

    2000-01-01

    We present model estimates of biogenic volatile organic compound (VOC) emissions from the forests in Finland. The emissions were calculated for the years 1995-1997 using the measured isoprene and monoterpene emission factors of boreal tree species together with detailed satellite land cover information and meteorological data. The three-year average emission is 319 kilotonnes per annum, which is significantly higher than the estimated annual anthropogenic VOC emissions of 193 kilotonnes. The biogenic emissions of the Finnish forests are dominated by monoterpenes, which contribute approximately 45% of the annual total. The main isoprene emitter is the Norway spruce (Picea abies) due to its high foliar biomass density. Compared to the monoterpenes, however, the total isoprene emissions are very low, contributing only about 7% of the annual forest VOC emissions. The isoprene emissions are more sensitive to the meteorological conditions than the monoterpene emissions, but the progress of the thermal growing season is clearly reflected in all biogenic emission fluxes. The biogenic emission densities in northern Finland are approximately half of the emissions in the southern parts of the country. (orig.)

  10. Advances in Biodegradation of Multiple Volatile Organic Compounds

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.

    2017-12-01

    Bioremediation of soil and groundwater containing multiple contaminants remains a challenge in environmental science and engineering because complete biodegradation of all components is necessary but very difficult to accomplish in practice. This presentation provides a brief overview on advances in biodegradation of multiple volatile organic compounds (VOCs) including chlorinated ethylenes, benzene, toluene and dichloromethane (DCM). Case studies on aerobic biodegradation of benzene, toluene and DCM, and integrated anaerobic-aerobic biodegradation of 7 contaminants, specifically, tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), vinyl chloride (VC), DCM, benzene and toluene will be provided. Recent findings based on systematic laboratory experiments indicated that aerobic toluene degradation can be enhanced by co-existence of benzene. Propioniferax, not a known benzene, toluene and DCM degrader can be a key microorganism that involves in biodegradation when the three contaminants co-exist. Integrated anaerobic-aerobic biodegradation is capable of completely degrading the seven VOCs with initial concentrations less than 30 mg/L. Dehalococcoides sp., generally considered sensitive to oxygen, can survive aerobic conditions for at least 28 days, and can be activated during the subsequent anaerobic biodegradation. This presentation may provide a systematic information about biodegradation of multiple VOCs, and a scientific basis for the complete bioremediation of multiple contaminants in situ.

  11. [Indoor volatile organic compounds: concentrations, sources, variation factors].

    Science.gov (United States)

    Palot, A; Charpin-Kadouch, C; Ercoli, J; Charpin, D

    2008-06-01

    Volatile organic compounds (V.O.C.) are part of urban air pollution and are also generated indoors from cleaning and maintenance products. VOC measurements are, on average, 10 times higher within homes than outside. Results of the national survey led by the Observatoire National de la Qualité de l'Air Intérieur demonstrated that up to 25% of French homes have very high or high concentrations of VOC. Indoor levels depend mainly on indoor sources. Aldehydes are included in many everyday life products. VOC originate from various household decorating and cleaning products. Some products are less detrimental to the environment and health and have special labelling. Indoor VOC levels also depend on the rate of air exchange and on household characteristics such as indoor temperature and humidity, age of the building, presence of smokers, and communication with a garage. The public may participate in maintaining good indoor air quality and the authorities should also improve regulations. VOC are part of everyday air pollution. Their sources and concentrations should be better monitored.

  12. Volatile organic compounds adsorption using different types of adsorbent

    Directory of Open Access Journals (Sweden)

    Pimanmes Chanayotha

    2014-09-01

    Full Text Available Adsorbents were synthesized from coconut shell, coal and coke by pyrolysis followed by chemical activation process. These synthesized materials were used as adsorbents in adsorption test to determine the amount of volatile organic compounds (VOCs namely, 2-Hydroxyethyl methacrylate (HEMA, Octamethylcyclotetrasiloxane and Alkanes standard solution (C8-C20. The adsorption capacities of both synthesized adsorbents and commercial grade adsorbents (Carbotrap™ B and Carbotrap™ C were also compared. It was found that adsorbent A402, which was produced from coconut shell, activated with 40% (wt. potassium hydroxide and at activating temperature of 800°C for 1 hr, could adsorb higher amount of both HEMA and Octamethylcyclotetrasiloxane than other synthesized adsorbents. The maximum adsorption capacity of adsorbent A402 in adsorbing HEMA and Octamethylcyclotetrasiloxane were 77.87% and 50.82% respectively. These adsorption capabilities were 79.73% and 70.07% of the adsorption capacity of the commercial adsorbent Carbotrap™ B respectively. All three types of the synthesized adsorbent (A402, C302, C402 showed the capability to adsorb alkanes standard solution through the range of C8-C20 . However, their adsorption capacities were high in a specific range of C10-C11. The result from the isotherm plot was indicated that surface adsorption of synthesized adsorbent was isotherm type I while the surface adsorption of commercial adsorbent was isotherm type III.

  13. Detection of semi-volatile organic compounds in permeable ...

    Science.gov (United States)

    Abstract The Edison Environmental Center (EEC) has a research and demonstration permeable parking lot comprised of three different permeable systems: permeable asphalt, porous concrete and interlocking concrete permeable pavers. Water quality and quantity analysis has been ongoing since January, 2010. This paper describes a subset of the water quality analysis, analysis of semivolatile organic compounds (SVOCs) to determine if hydrocarbons were in water infiltrated through the permeable surfaces. SVOCs were analyzed in samples collected from 11 dates over a 3 year period, from 2/8/2010 to 4/1/2013.Results are broadly divided into three categories: 42 chemicals were never detected; 12 chemicals (11 chemical test) were detected at a rate of less than 10% or less; and 22 chemicals were detected at a frequency of 10% or greater (ranging from 10% to 66.5% detections). Fundamental and exploratory statistical analyses were performed on these latter analyses results by grouping results by surface type. The statistical analyses were limited due to low frequency of detections and dilutions of samples which impacted detection limits. The infiltrate data through three permeable surfaces were analyzed as non-parametric data by the Kaplan-Meier estimation method for fundamental statistics; there were some statistically observable difference in concentration between pavement types when using Tarone-Ware Comparison Hypothesis Test. Additionally Spearman Rank order non-parame

  14. Ionic liquid technology to recover volatile organic compounds (VOCs).

    Science.gov (United States)

    Salar-García, M J; Ortiz-Martínez, V M; Hernández-Fernández, F J; de Los Ríos, A P; Quesada-Medina, J

    2017-01-05

    Volatile organic compounds (VOCs) comprise a wide variety of carbon-based materials which are volatile at relatively low temperatures. Most of VOCs pose a hazard to both human health and the environment. For this reason, in the last years, big efforts have been made to develop efficient techniques for the recovery of VOCs produced from industry. The use of ionic liquids (ILs) is among the most promising separation technologies in this field. This article offers a critical overview on the use of ionic liquids for the separation of VOCs both in bulk and in immobilized form. It covers the most relevant works within this field and provides a global outlook on the limitations and future prospects of this technology. The extraction processes of VOCs by using different IL-based assemblies are described in detail and compared with conventional methods This review also underlines the advantages and limitations posed by ionic liquids according to the nature of the cation and the anions present in their structure and the stability of the membrane configurations in which ILs are used as liquid phase. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Volatile organic compounds in the atmosphere of Mexico City

    Science.gov (United States)

    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.

  16. Processing of volatile organic compounds by microwave plasmas

    International Nuclear Information System (INIS)

    Mizeraczyk, J.; Jasinski, M.; Dors, M.; Zakrzewski, Z.

    2011-01-01

    In this paper atmospheric pressure microwave discharge methods and devices used for producing the nonthermal plasmas for processing of gases are presented. The main part of the paper concerns the microwave plasma sources (MPSs) for environmental protection applications. A few types of the MPSs, i.e. waveguidebased surface wave sustained MPS, coaxial-line-based and waveguide-based nozzle-type MPSs, waveguidebased nozzleless cylinder-type MPS and MPS for microdischarges are presented. Also, results of the laboratory experiments on the plasma processing of several highly-concentrated (up to several tens percent) volatile organic compounds (VOCs), including Freon-type refrigerants, in the moderate (200-400 W) waveguide-based nozzletype MPS (2.45 GHz) are presented. The results showed that the microwave discharge plasma fully decomposed the VOCs at relatively low energy cost. The energy efficiency of VOCs decomposition reached 1000 g/kWh. This suggests that the microwave discharge plasma can be a useful tool for environmental protection applications. In this paper also results of the use of the waveguide-based nozzleless cylinder-type MPS to methane reforming into hydrogen are presented. (author)

  17. Production of volatile organic compounds by cyanobacteria Synechococcus sp.

    Science.gov (United States)

    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).

  18. Advanced heat pump for the recovery of volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The Toxic-Release Inventory'' of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

  19. Volatile organic compound monitoring by photo acoustic radiometry

    International Nuclear Information System (INIS)

    Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

    1995-01-01

    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 μm. 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

  20. Processing of volatile organic compounds by microwave plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mizeraczyk, J. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Gdansk (Poland); Department of Marine Electronics, Gdynia Martime University, Gdynia (Poland); Jasinski, M.; Dors, M.; Zakrzewski, Z. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Gdansk (Poland)

    2011-07-01

    In this paper atmospheric pressure microwave discharge methods and devices used for producing the nonthermal plasmas for processing of gases are presented. The main part of the paper concerns the microwave plasma sources (MPSs) for environmental protection applications. A few types of the MPSs, i.e. waveguidebased surface wave sustained MPS, coaxial-line-based and waveguide-based nozzle-type MPSs, waveguidebased nozzleless cylinder-type MPS and MPS for microdischarges are presented. Also, results of the laboratory experiments on the plasma processing of several highly-concentrated (up to several tens percent) volatile organic compounds (VOCs), including Freon-type refrigerants, in the moderate (200-400 W) waveguide-based nozzletype MPS (2.45 GHz) are presented. The results showed that the microwave discharge plasma fully decomposed the VOCs at relatively low energy cost. The energy efficiency of VOCs decomposition reached 1000 g/kWh. This suggests that the microwave discharge plasma can be a useful tool for environmental protection applications. In this paper also results of the use of the waveguide-based nozzleless cylinder-type MPS to methane reforming into hydrogen are presented. (author)

  1. Personal exposure to volatile organic compounds in the Czech Republic.

    Science.gov (United States)

    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 (Pfireplace 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).

  2. Volatile organic compounds discrimination based on dual mode detection

    Science.gov (United States)

    Yu, Yuanyuan; Wu, Enxiu; Chen, Yan; Feng, Zhihong; Zheng, Shijun; Zhang, Hao; Pang, Wei; Liu, Jing; Zhang, Daihua

    2018-06-01

    We report on a volatile organic compound (VOC) sensor that can provide concentration-independent signals toward target gases. The device is based on a dual-mode detection mechanism that can simultaneously record the mechanical (resonant frequency, f r) and electrical (current, I) responses of the same gas adsorption event. The two independent signals form a unique I–f r trace for each target VOC as the concentration varies. The mechanical response (frequency shift, Δf r) resulting from mass load on the device is directly related to the amount of surface adsorptions, while the electrical response (current variation, ΔI) is associated with charge transfer across the sensing interface and changes in carrier mobility. The two responses resulting from independent physical processes reflect intrinsic physical properties of each target gas. The ΔI–Δf r trace combined with the concentration dependent frequency (or current) signals can therefore be used to achieve target both recognition and quantification. The dual-mode device is designed and fabricated using standard complementary metal oxide semiconductor (CMOS) compatible processes. It exhibits consistent and stable performance in our tests with six different VOCs including ethanol, methanol, acetone, formaldehyde, benzene and hexane.

  3. Characterization of volatile organic compounds from different cooking emissions

    Science.gov (United States)

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

    2016-11-01

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

  4. Prediction of boiling points of organic compounds by QSPR tools.

    Science.gov (United States)

    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Remediation of ground water containing volatile organic compounds and tritium

    International Nuclear Information System (INIS)

    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

  6. Volatile organic compounds in emissions from brown-coal-fired residential stoves

    International Nuclear Information System (INIS)

    Engewald, W.; Knobloch, T.; Efer, J.

    1993-01-01

    Volatile organic compounds were determined in stack-gas emissions from the residential burning of brown-coal briquets using adsorptive enrichment on hydrophobic adsorbents, thermal desorption and capillary-gas chromatographic analysis. 152 compounds were identified and quantified. Quantitative emission factors of the identified individual compounds were determined in relation to the amount of the fuel used. These factors permit assessment of the pollution of the city of Leipzig with volatile organic compounds resulting from the burning of indigenous lignite. (orig.) [de

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

    Data.gov (United States)

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

  8. Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong

    Science.gov (United States)

    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

  9. Volatile organic compounds and secondary organic aerosol in the Earth's atmosphere

    International Nuclear Information System (INIS)

    Galbally, Ian

    2007-01-01

    Full text: Recent research, when considered as a whole, suggests that a substantial fraction of both gas-phase and aerosol atmospheric organics have not been, or have very rarely been, directly measured. A review of the global budget for organic gases shows that we cannot account for the loss of approximately half the non-methane organic carbon entering the atmosphere. We suggest that this unaccounted-for loss most likely occurs through formation of secondary organic aerosols (SOAs), indicating that the source for these aerosols is an order of magnitude larger than current estimates. There is evidence that aged secondary organic aerosol can participate in both direct and indirect (cloud modifying) radiative forcing and that this influence may change with other global climate change. Even though our knowledge of the organic composition of the atmosphere is limited, these compounds clearly influence the reactive chemistry of the atmosphere and the formation, composition, and climate impact of aerosols A major challenge in the coming decade of atmospheric chemistry research will be to elucidate the sources, structure, chemistry, fate and influences of these clearly ubiquitous yet poorly constrained organic atmospheric constituents

  10. Natural halogenated compounds in forest soils

    DEFF Research Database (Denmark)

    Albers, Christian Nyrop

    Formålet med nærværende afhandling er at undersøge forekomst, dannelse og skæbne af halogenerede organiske stoffer, dannet gennem naturlige processer i jorden. Halogenerede og herunder specielt klorerede stoffer har haft et stærkt fokus inden for miljøkemien i de sidste 40 år, på grund af de mang...

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

    OpenAIRE

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

    2017-01-01

    A biogeochemical connection between the atmosphere and the ocean is demonstrated whereby a marine source of oxygenated volatile organic compounds is identified. Compounds of this type are involved in the formation of secondary organic aerosol, which remains one of the most poorly understood components of Earth’s climate system due in part to the diverse sources of its volatile organic compound precursors. This is especially the case for marine environments, where there are more oxygenated vol...

  12. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    Science.gov (United States)

    Doherty, J.P.; Marek, J.C.

    1987-02-25

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

  13. Passive remediation of chlorinated volatile organic compounds using barometric pumping

    International Nuclear Information System (INIS)

    Rossabi, J.; Looney, B.B.; Dilek, C.A.E.; Riha, B.; Rohay, V.J.

    1993-01-01

    The purpose of the Savannah River Integrated Demonstration Program, sponsored by the Department of Energy, is to demonstrate new subsurface characterization, monitoring, and remediation technologies. The interbedded clay and sand layers at the Integrated Demonstration Site (IDS) are contaminated with chlorinated volatile organic compounds (CVOCs). Characterization studies show that the bulk of the contamination is located in the approximately 40 m thick vadose zone. The most successful strategy for removing contaminants of this type from this environment is vapor extraction alone or in combination with other methods such as air sparging or enhanced bioremediation. Preliminary work at the IDS has indicated that natural pressure differences between surface and subsurface air caused by surface barometric fluctuations can produce enough gas flow to make barometric pumping a viable method for subsurface remediation. Air flow and pressure were measured in wells that are across three stratigraphic intervals in the vadose zone' The subsurface pressures were correlated to surface pressure fluctuations but were damped and lagging in phase corresponding to depth and stratum permeability. Piezometer wells screened at lower elevations exhibited a greater phase lag and damping than wells screened at higher elevations where the pressure wave from barometric fluctuations passes through a smaller number of low permeable layers. The phase lag between surface and subsurface pressures results in significant fluxes through these wells. The resultant air flows through the subsurface impacts CVOC fate and transport. With the appropriate controls (e.g. solenoid valves) a naturally driven vapor extraction system can be implemented requiring negligible operating costs yet capable of a large CVOC removal rate (as much as 1--2 kg/day in each well at the IDS)

  14. Diagnosing Tibetan pollutant sources via volatile organic compound observations

    Science.gov (United States)

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

    2017-10-01

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

  15. Transport of volatile organic compounds across the capillary fringe

    Science.gov (United States)

    McCarthy, Kathleen A.; Johnson, Richard L.

    1993-01-01

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

  16. Mass transfer of nonvolatile organic compounds from porous media

    Science.gov (United States)

    Khachikian, Crist Simon

    This thesis presents data pertaining to the mass transfer of nonvolatile organic compounds from porous media. Physical properties of porous solids, including surface and pore areas, are studied. Information from these studies, along with dissolution data, are used to develop correlations relating the Sherwood Number to the Peclet Number. The contaminant used in this study is naphthalene; the solids used are Moffett Sand (MS), Borden Sand (BS), Lampblack (LB), and Silica Gel (SG). Surface area results indicate that contamination at 0.1% reduces the area of MS and SG by 48 and 37%, respectively, while contamination at 1.0% reduces the area of MS, BS, and SG by 59, 56, and 40%, respectively. Most of the reduction in area originates in the reduction of pore areas and volumes, where the contaminant precipitates. After long-term storage, surface areas did not recover to their original values due to an "irreversible" fraction of naphthalene. Treatment with heat or solvent or both was necessary to completely remove the contamination. For lampblack, treatment at 100°C decreased areas while treatment at 250°C increased them. Treatment at 250°°C probably opened pores while that at 100°C may have blocked more pores by redistributing the tar-like contaminant characteristic of lampblack. Contaminated MS and SG solids are packed in columns through which water is pumped. The effluent began at a relatively high concentration (˜70% of solubility) for both samples. However, SG column concentrations dropped quickly, never achieving steady state while the MS samples declined more gradually towards steady state. The high pore areas of the SG samples are believed to cause this behavior. The steady state portion of the MS dissolution history is used to develop mass transfer correlations. The correlation in this study differs from previous work in two major ways: (1) the exponent on the Pe is three times larger and (2) the limiting Sh is 106 times smaller. These results suggest that

  17. Virus, protozoa and organic compounds decay in depurated oysters.

    Science.gov (United States)

    Souza, Doris Sobral Marques; Piazza, Rômi Sharon; Pilotto, Mariana Rangel; do Nascimento, Mariana de Almeida; Moresco, Vanessa; Taniguchi, Satie; Leal, Diego Averaldo Guiguet; Schmidt, Éder der Carlos; Cargin-Ferreira, Eduardo; Bícego, Márcia Caruso; Sasaki, Silvio Tarou; Montone, Rosalinda Carmela; de Araujo, Rafael Alves; Franco, Regina Maura Bueno; Bouzon, Zenilda Laurita; Bainy, Afonso Celso Dias; Barardi, Célia Regina Monte

    2013-11-01

    (1) Evaluate the dynamic of the depuration process of Crassostrea gigas oysters using different ultraviolet doses with different amounts of contaminants (virus, protozoa and organic contaminants) and (2) investigate the morphological changes in the oysters' tissues produced by the depuration procedures. The oysters were allocated in sites with different degrees of contamination and analyzed after 14 days. Some animals were used as positive controls by artificial bioaccumulation with HAdV2 and MNV1 and subjected to depuration assays using UV lamps (18 or 36 W) for 168 h. The following pollutants were researched in the naturally contaminated oysters, oysters after 14 days in sites and oysters during the depuration processes: virus (HAdV, HAV, HuNoV GI/GII and JCPyV), by (RT) qPCR; protozoa (Cryptosporidium and Giardia species), by immunomagnetic separation and immunofluorescence; and organic compounds (AHs, PAHs, LABs, PCBs and organochlorine pesticides-OCs), by chromatography. Changes in the oysters' tissues produced by the depuration processes were also evaluated using histochemical analysis by light microscopy. In the artificially bioaccumulated oysters, only HAdV2 and MNV1 were investigated by (RT) qPCR before the depuration procedures and after 96 and 168 h of these procedures. At 14 days post-allocation, HAdV was found in all the sites (6.2 × 105 to 4.4 × 107 GC g(-1)), and Giardia species in only one site. Levels of PCBs and OCs in the oyster's tissues were below the detection limit for all samples. AHs (3.5 to 4.4 μg g(-1)), PAHs (11 to 191 ng g(-1)) and LABs (57 to 751 ng g(-1)) were detected in the samples from 3 sites. During the depuration assays, we found HAdV, Giardia and Cryptosporidium species until 168 h, independent of UV treatment. AHs, PAHs and LABs were found also after 168 h of depuration (36 W and without UV lamp). The depuration procedures did not produce changes in the oysters' tissues. In the artificially contaminated and depurated

  18. Studies on the use of haloperoxidases in organic synthesis

    NARCIS (Netherlands)

    Franssen, M.C.R.

    1987-01-01

    The subject of this thesis is the use of haloperoxidases in synthetic organic chemistry. Haloperoxidases are enzymes capable of halogenating a variety of organic compounds. They require hydrogen peroxide and halide ions as cosubstrates. The enzymes operate under mild conditions, compared to

  19. Interactions of the Calcite {10.4} Surface with Organic Compounds: Structure and Behaviour at Mineral – Organic Interfaces

    DEFF Research Database (Denmark)

    Hakim, S. S.; Olsson, M. H. M.; Sørensen, H. O.

    2017-01-01

    The structure and the strength of organic compound adsorption on mineral surfaces are of interest for a number of industrial and environmental applications, oil recovery, CO2 storage and contamination remediation. Biomineralised calcite plays an essential role in the function of many organisms...... that control crystal growth with organic macromolecules. Carbonate rocks, composed almost exclusively of calcite, host drinking water aquifers and oil reservoirs. In this study, we examined the ordering behaviour of several organic compounds and the thickness of the adsorbed layers formed on calcite {10...... monolayers. The results of this work indicate that adhered organic compounds from the surrounding environment can affect the surface behaviour, depending on properties of the organic compound....

  20. Formation of organobromine and organoiodine compounds by engineered TiO2 nanoparticle-induced photohalogenation of dissolved organic matter in environmental waters.

    Science.gov (United States)

    Hao, Zhineng; Yin, Yongguang; Wang, Juan; Cao, Dong; Liu, Jingfu

    2018-08-01

    There are increasing concerns about the adverse effects of released engineered nanoparticles and photochemically formed organohalogen compounds (OHCs) on human health and the environment. Herein, we report that titanium dioxide nanoparticles (TiO 2 NPs) can photocatalytically halogenate dissolved organic matter (DOM) to form a large number of organobromine compounds (OBCs) and organoiodine compounds (OICs), as characterized by negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry. Compared with no OHCs produced in control samples in darkness and/or without TiO 2 NPs under sunlight irradiation, various OBCs and OICs were detected in freshwater and seawater under sunlight irradiation for 12h and 24h even in the presence of 1mgL -1 TiO 2 NPs, indicating the photocatalytic roles TiO 2 NPs played in DOM halogenation. Furthermore, TiO 2 NPs could result in the photodegradation of newly formed OHCs, as evidenced by the intensity and the number of some OHCs decreased with reaction time. In addition, many TiO 2 NP-induced OBCs contained two or three bromine atoms, and/or nitrogen and sulfur elements, belonging to lignin-like, tannin-like, unsaturated hydrocarbon and aliphatic compounds. While the OICs were primarily contained one iodine, and very few consisted of nitrogen and sulfur elements, most were lignin-like and tannin-like compounds. Finally, the OBCs in freshwater were found to be formed mainly via a substitution reaction or addition reaction and were accompanied by other reactions such as photooxidation, while the OBCs in seawater and OICs were formed primarily via substitution reactions. Given the abundance of produced OHCs and their toxicity, our findings call for further studies on the exact structure and toxicity of the formed OHCs, taking account the TiO 2 NP-induced DOM photohalogenation in aquatic environments during the evaluation of the environmental effects of engineered TiO 2 NPs. Copyright © 2018

  1. Theoretical study of stability and charge-transport properties of coronene molecule and some of its halogenated derivatives: A path to ambipolar organic-based materials?

    Energy Technology Data Exchange (ETDEWEB)

    Sancho-García, J. C., E-mail: jc.sancho@ua.es; Pérez-Jiménez, A. J., E-mail: aj.perez@ua.es [Departamento de Química Física, Universidad de Alicante, E-03080 Alicante (Spain)

    2014-10-07

    We have carefully investigated the structural and electronic properties of coronene and some of its fluorinated and chlorinated derivatives, including full periphery substitution, as well as the preferred orientation of the non-covalent dimer structures subsequently formed. We have paid particular attention to a set of methodological details, to first obtain single-molecule magnitudes as accurately as possible, including next the use of modern dispersion-corrected methods to tackle the corresponding non-covalently bound dimers. Generally speaking, this class of compounds is expected to self-assembly in neighboring π-stacks with dimer stabilization energies ranging from –20 to –30 kcal mol{sup −1} at close distances around 3.0–3.3 Å. Then, in a further step, we have also calculated hole and electron transfer rates of some suitable candidates for ambipolar materials, and corresponding charge mobility values, which are known to critically depend on the supramolecular organization of the samples. For coronene and per-fluorinated coronene, we have found high values for their hopping rates, although slightly smaller for the latter due to an increase (decrease) of the reorganization energies (electronic couplings)

  2. Neutron diffraction by monocrystals of inorganic and elementary organic compounds

    International Nuclear Information System (INIS)

    Becker, G.; Hauser, H.D.

    1992-01-01

    The phase of preparation and X-ray structural analysis of the compounds has been completed following the synthetical preparation of compounds sensitive to oxidation and pyrolysis, in this case: phosphonic acid, potassium silanide, lithium dihydrogenphosphide * DME, bis[lithium-tri(tert.butyl)alanate], dibromophenylbismuthate, potassium tetrahydride aluminate, and phosphinic acid. The work was started is neutron diffraction experiments for detecting the positions of the hydrogen and carbon atoms, in order to analyse space group problems. (BBR) [de

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-07

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

  4. Removal of chlorinated organic compounds from gas phase using electron beam technology

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.; Bulka, S.; Zimek, A. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Chmielewski, A. G. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw (Poland)

    2011-07-01

    Selected chlorinated organic compounds (Cl-HC), which are emitted from coal fired power plants, waste incinerators, chemical industry etc., are very harmful to the environment and human’s health. Some of them are listed as carcinogenic compounds by USA EPA. Recent studies show that some chlorinated organic compounds are suspected to be precursors for dioxins formation. Chlorinated organic compounds decomposition in air in an electron beam (EB) generated plasma reactor technology was studied. We selected cis-dichloroethylene (cis-DCE), 1,4-dichlorobenznene(1,4-DCB), 1-chloronaphthalene as studied objects. It is found that chlorinated organic compounds can be decomposed in an electron beam generated plasma reactor. The order of decomposition efficiency of these compounds are: cis-DCE > 1,4-DCB> 1-chloronaphthalene. (author)

  5. Chemical Reductive Transformations of Synthetic Organic Compounds. Probe Compound Studies and Mechanistic Modeling

    National Research Council Canada - National Science Library

    Peyton, Gary

    2001-01-01

    Advanced Oxidation Processes (AOPs) can be used to selectively remove DNT (2,4-dinitrotoluene) from a complex waste stream by adding a precursor compound such as ethanol, which forms a reducing radical upon reaction with hydroxyl radical...

  6. Crystallization of an organic compound from an ionic liquid using carbon dioxide as anti-solvent

    NARCIS (Netherlands)

    Kroon, M.C.; Toussaint, V.A.; Shariati - Sarabi, A.; Florusse, L.J.; Spronsen, van J.; Witkamp, G.J.; Peters, C.J.

    2008-01-01

    In this paper the anti-solvency behavior of supercritical carbon dioxide (CO2) as a way to recover an organic compound from an ionic liquid by crystallization is explored. As an example, the conditions for crystallization of the organic compound methyl-(Z)-a-acetamido cinnamate (MAAC) from the ionic

  7. Coordination compounds of rare-earth metals with organic ligands for electroluminescent diodes

    International Nuclear Information System (INIS)

    Katkova, M A; Bochkarev, Mikhail N; Vitukhnovsky, Alexey G

    2005-01-01

    Data on lanthanide coordination compounds with organic ligands used in the design of electroluminescent diodes are summarised and systematically represented. The molecular and electronic structures and spectroscopic characteristics of these compounds are considered. A comparative analysis of the properties of organic electroluminescent diodes with different compositions of emitting and conductive layers is presented.

  8. End-group-directed self-assembly of organic compounds useful for photovoltaic applications

    Science.gov (United States)

    Beaujuge, Pierre M.; Lee, Olivia P.; Yiu, Alan T.; Frechet, Jean M.J.

    2016-05-31

    The present invention provides for an organic compound comprising electron deficient unit covalently linked to two or more electron rich units. The present invention also provides for a device comprising the organic compound, such as a light-emitting diode, thin-film transistor, chemical biosensor, non-emissive electrochromic, memory device, photovoltaic cells, or the like.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-01

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

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

  10. Characteristics of organic compounds in PM2.5 at urban and remote areas in Korea

    Science.gov (United States)

    Choi, A.; Lee, J.; Shin, H. J.; Lee, M.; Jin seok, H.; Lim, J.

    2016-12-01

    Organic aerosols contain thousands of organic compounds and contribute to 20%-90% of the total fine aerosol mass (Kanakidou et al., 2005). These organic aerosols originate from anthropogenic and natural (biogenic and geologic) sources and alter physical and chemical properties in the atmosphere depending on the atmospheric and meteorological conditions. About one hundred individual organic compounds in PM2.5 at Seoul (urban area) and Baengnyeong Island (remote area) were identified and quantified using gas chromatography/mass spectrometry (GC/MS) in order to understand the characteristics of organic compounds in PM2.5 at these areas. Further, major factors to determine their concentrations in the atmosphere were investigated. Organic compounds analyzed in this study were classified into six groups, n-alkanes, polycyclic aromatic hydrocarbons (PAHs), hopanes, fatty acids (FA), dicarboxylic acids (DCAs), and sugars. Daily variation of organic compounds concentrations at Seoul were not high, while, the concentrations of organic compounds at Baengnyeong Island showed high daily variation. This is might due to frequent change of source strength and/or SOA formation in this region. Through correlations of organic compounds with other air pollutants and factor analysis at both sites, it found that major factors (or source) for the determination of organic compounds concentrations at Seoul and Baengnyeong Island were different. The major sources at Seoul were anthropogenic sources such as vehicular emission and coal combustions, while, SOA formation and biomass burning were more attributed more to the organic compounds concentrations at Baengnyeong Island.References Kanakidou, M., Seinfeld, J.H., Pandis, S.N., Barnes, I., Dentener, F.J., Facchini, M.C., Van Dingenen, R., Ervens, B., Nenes, A., Nielsen, C.J., Swietlicki, E., Putaud, J.P., Balkanski, Y., Fuzzi, S., Horth, J., Moortgat, G.K., Winterhalter, R., Myhre, C.E.L., Tsigaridis, K., Vignati, E., Stephanou, E

  11. Methods and systems for chemoautotrophic production of organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Curt R.; Che, Austin J.; Shetty, Reshma P.; Kelly, Jason R.

    2018-02-27

    The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

  12. Cloud processing of organic compounds: Secondary organic aerosol and nitrosamine formation

    Science.gov (United States)

    Hutchings, James W., III

    Cloud processing of atmospheric organic compounds has been investigated through field studies, laboratory experiments, and numerical modeling. Observational cloud chemistry studies were performed in northern Arizona and fog studies in central Pennsylvania. At both locations, the cloud and fogs showed low acidity due to neutralization by soil dust components (Arizona) and ammonia (Pennsylvania). The field observations showed substantial concentrations (20-5500 ng•L -1) of volatile organic compounds (VOC) in the cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase with half lives of approximately three hours. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction kinetics decreased with increasing organic carbon content, resulting in half lives of approximately 7 hours. The secondary organic aerosol (SUA) mass formation potential of cloud processing of BTEX was evaluated. SOA mass formation by cloud processing of BTEX, while strongly dependent on the atmospheric conditions, could contribute up to 9% of the ambient atmospheric aerosol mass, although typically ˜1% appears realistic. Field observations also showed the occurrence of N-nitrosodimethylamine (NDMA), a potent carcinogen, in fogs and clouds (100-340 ng•L -1). Laboratory studies were conducted to investigate the formation of NDMA from nitrous acid and dimethylamine in the homogeneous aqueous phase within cloud droplets. While NDMA was produced in the cloud droplets, the low yields (NDMA with partitioning to droplet must be the source of aqueous

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    This study presents the chemical composition of VOCs in air and gas discharges collected at Nisyros Island (Dodecanese Archipelago, Greece). The main goals are i) to discriminate between natural and anthropogenic VOC sources and ii) to evaluate their impact on local air quality. Up to 63 different VOCs were recognized and quantitatively determined in 6 fumaroles and 19 air samples collected in the Lakki caldera, where fumarolic emissions are located, and the outer ring of the island, including the Mandraki village and the main harbor. Air samples from the crater area show significant concentrations of alkanes, alkenes, cyclic, aromatics, and S- and O-bearing heterocycles directly deriving from the hydrothermal system, as well as secondary O-bearing compounds from oxidation of primary VOCs. At Mandraki village, C 6 H 6 /Σ(methylated aromatics) and Σ(linear)/Σ(branched) alkanes ratios 2 O–CO 2 –H 2 S rich and discharge a large variety of VOC species. •Benzene/toluene ratios identify anthropogenic and natural sources of VOCs in air. •Aldehydes in air are produced by oxidation of alkanes and alkenes. •Geogenic furans and hydrogenated halocarbons in air are recalcitrant. -- Anthropogenic and natural VOCs in air are distinguished on the basis of aromatic, O-substituted, S-substituted and halogenated compounds

  14. Fruit tree model for uptake of organic compounds from soil

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rasmussen, D.; Samsoe-Petersen, L.

    2003-01-01

    -state, and an example calculation is given. The Fruit Tree Model is compared to the empirical equation of Travis and Arms (T&A), and to results from fruits, collected in contaminated areas. For polar compounds, both T&A and the Fruit Tree Model predict bioconcentration factors fruit to soil (BCF, wet weight based......) of > 1. No empirical data are available to support this prediction. For very lipophilic compounds (log K-OW > 5), T&A overestimates the uptake. The conclusion from the Fruit Tree Model is that the transfer of lipophilic compounds into fruits is not relevant. This was also found by an empirical study...... with PCDD/F. According to the Fruit Tree Model, polar chemicals are transferred efficiently into fruits, but empirical data to verify these predictions are lacking....

  15. Determination of N-containing halogenated natural products using gas chromatography in combination of a nitrogen-phosphorus-detector

    Energy Technology Data Exchange (ETDEWEB)

    Melcher, J.; Vetter, W. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Lebensmittelchemie

    2004-09-15

    In the last few years several nonpolar halogenated natural products (HNPs) such as Q1, MHC-1, BC-2, BC-3, BC-10 were detected at elevated concentrations in marine biota samples. In addition, there are still some abundant peaks of halogenated compounds frequently found in the gas chromatograms of many marine samples which have not yet been identified. Some of the known halogenated natural products (Q1, HDBPs including BC-10, bromoindoles) contain N-heterocyclic backbones. Since nitrogen is scarcely found in anthropogenic halogenated compounds, the detection of N-containing halogenated substances may be used as a first indicator for the presence of HNPs in a sample extract. In the presented method we studied the suitability of a nitrogen phosphorous detector (NPD) for quantification of Q1 and the detection of Ncontaining compounds in marine biota. Analyses were accompanied with GC/ECD analyses.

  16. Effects of airborne volatile organic compounds on plants

    International Nuclear Information System (INIS)

    Cape, J.N.

    2003-01-01

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

  17. Evidence for Interfacial Halogen Bonding.

    Science.gov (United States)

    Swords, Wesley B; Simon, Sarah J C; Parlane, Fraser G L; Dean, Rebecca K; Kellett, Cameron W; Hu, Ke; Meyer, Gerald J; Berlinguette, Curtis P

    2016-05-10

    A homologous series of donor-π-acceptor dyes was synthesized, differing only in the identity of the halogen substituents about the triphenylamine (TPA; donor) portion of each molecule. Each Dye-X (X=F, Cl, Br, and I) was immobilized on a TiO2 surface to investigate how the halogen substituents affect the reaction between the light-induced charge-separated state, TiO2 (e(-) )/Dye-X(+) , with iodide in solution. Transient absorption spectroscopy showed progressively faster reactivity towards nucleophilic iodide with more polarizable halogen substituents: Dye-F < Dye-Cl < Dye-Br < Dye-I. Given that all other structural and electronic properties for the series are held at parity, with the exception of an increasingly larger electropositive σ-hole on the heavier halogens, the differences in dye regeneration kinetics for Dye-Cl, Dye-Br, and Dye-I are ascribed to the extent of halogen bonding with the nucleophilic solution species. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Molar extinction coefficients of solutions of some organic compounds

    Indian Academy of Sciences (India)

    efficients of these compounds have been used to calculate effective atomic numbers and electron densities. The additivity ... Molar extinction coefficients; effective atomic numbers; electron density. PACS Nos 29.30. ... the radiation path and is linearly dependent on the concentration of the absorbing species. This is most ...

  19. Green Synthetic Alternatives to Organic Compounds and Nanomaterials

    Science.gov (United States)

    A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedia...

  20. Rapid NMR method for the quantification of organic compounds in thin stillage.

    Science.gov (United States)

    Ratanapariyanuch, Kornsulee; Shen, Jianheng; Jia, Yunhua; Tyler, Robert T; Shim, Youn Young; Reaney, Martin J T

    2011-10-12

    Thin stillage contains organic and inorganic compounds, some of which may be valuable fermentation coproducts. This study describes a thorough analysis of the major solutes present in thin stillage as revealed by NMR and HPLC. The concentration of charged and neutral organic compounds in thin stillage was determined by excitation sculpting NMR methods (double pulse field gradient spin echo). Compounds identified by NMR included isopropanol, ethanol, lactic acid, 1,3-propanediol, acetic acid, succinic acid, glycerophosphorylcholine, betaine, glycerol, and 2-phenylethanol. The concentrations of lactic and acetic acid determined with NMR were comparable to those determined using HPLC. HPLC and NMR were complementary, as more compounds were identified using both methods. NMR analysis revealed that stillage contained the nitrogenous organic compounds betaine and glycerophosphorylcholine, which contributed as much as 24% of the nitrogen present in the stillage. These compounds were not observed by HPLC analysis.

  1. Modeling of RO/NF membrane rejections of PhACs and organic compounds : A statistical analysis

    NARCIS (Netherlands)

    Yangali-Quintanilla, V.; Kim, T.U.; Kennedy, M.; Amy, G.

    2008-01-01

    Rejections of pharmaceutical compounds (Ibuprofen, Diclofenac, Clofibric acid, Naproxen, Primidone, Phenacetin) and organic compounds (Dichloroacetic acid, Trichloroacetic acid, Chloroform, Bromoform, Trichloroethene, Perchloroethene, Carbontetrachloride, Carbontetrabromide) by NF (Filmtec, Saehan)

  2. Comparison of the neurotoxicities between volatile organic compounds and fragrant organic compounds on human neuroblastoma SK-N-SH cells and primary cultured rat neurons

    Directory of Open Access Journals (Sweden)

    Yasue Yamada

    2015-01-01

    Full Text Available These are many volatile organic compounds (VOCs that are synthesized, produced from petroleum or derived from natural compounds, mostly plants. Fragrant and volatile organic compounds from plants have been used as food additives, medicines and aromatherapy. Several clinical and pathological studies have shown that chronic abuse of VOCs, mainly toluene, causes several neuropsychiatric disorders. Little is known about the mechanisms of neurotoxicity of the solvents. n-Octanal, nonanal, and 2-ethyl-1-hexanol, which are used catalyzers or intermediates of chemical reactions, are released into the environment. Essential oils have the functions of self-defense, sterilization, and antibiosis in plants. When volatile organic compounds enter the body, there is the possibility that they will pass through the blood–brain barrier (BBB and affect the central nervous system (CNS. However, the direct effects of volatile organic compounds on neural function and their toxicities are still unclear. We compared the toxicities of n-octanal, nonanal and 2-ethyl-1-hexanol with those of five naturally derived fragrant organic compounds (FOCs, linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and n-phenethyl alcohol. MTT assay of human neuroblastoma SK-N-SH cells showed that the IC50 values of linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and phenethyl alcohol were 1.33, 2.3, >5, >5, and 2.39 mM, respectively, and the IC50 values of toluene, n-octanal, nonanal and 2-ethyl-1-hexanol were 850, 37.2, 8.31 and 15.1 μM, respectively. FOCs showed lower toxicities than those of VOCs. These results indicate that FOCs are safer than other compounds.

  3. Thermal degradation of the vapours of organic nitrogen compounds in the presence of the air

    International Nuclear Information System (INIS)

    Brault, A.; Chevalier, G.; Kerfanto, M.; Loyer, H.

    1983-04-01

    Following a quick survey of the literature on the products originated during the thermal degradation of some organic nitrogen compounds, the experimental results obtained by applying a technique previously used for other organic compounds are presented. The compounds investigated include: methyl and ethylamines at the origin of the bad smells of many gaseous wastes, trilaurylamine and tetraethylenediamine sometimes used in nuclear facilities. Attention is brought on the emission of noxious products during thermal degradation in the presence of the air, at various temperatures, viz. either usual combustion gases such as carbon monoxide, or nitro-derivatives such as hydrogen cyanide present whatever the compound investigated when temperatures are below 850 0 C [fr

  4. Fiscal 1998 achievement report on regional consortium research and development project. Venture business fostering regional consortium research and development in its 2nd year--Creation of key industries (Development of energy-efficient catalytic decomposition device for persistent halogen compounds for environmental conservation); 1998 nendo kankyo hozen no tame no nanbunkaisei halogen kagobutsu no sho energy shokubai bunkai sochi no kaihatsu seika hokokusho. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Devices that decompose halogen compounds by use of AlPO{sub 4} are built, and studies are made concerning the collection of basic knowledge and findings, the settlement of problems that accompany scaleup, and the elucidation of mechanism of catalytic function occurrence. Tests are conducted at an intermediate plant, when catalytic performance is observed using a unit accommodating 1 liter of catalyst and chlorofluorocarbon (CFC) 12 is subjected to decomposition for the selection of proper operating conditions. Results similar to those from micro-reactor operation are attained when the reaction tube temperature is controlled. On the basis of the results, a real reactor and reaction system are designed and constructed, and CFC12 containing some CFC115 and CFC22 is made to undergo a decomposition reaction in this real reactor. It is then clarified that CFC catalytic decomposition proceeds at a low cost without generating dioxins and that therefore the process is commercially viable. In the study of catalytic adjustment, it is found that adjustment may be sufficiently effected when baking is conducted at 1,000 degrees C even when the extrusion process which demands low manufacturing cost is employed. Studies are also conducted about the mechanism of co-catalytic function occurrence. (NEDO)

  5. The unique role of halogen substituents in the design of modern agrochemicals.

    Science.gov (United States)

    Jeschke, Peter

    2010-01-01

    The past 30 years have witnessed a period of significant expansion in the use of halogenated compounds in the field of agrochemical research and development. The introduction of halogens into active ingredients has become an important concept in the quest for a modern agrochemical with optimal efficacy, environmental safety, user friendliness and economic viability. Outstanding progress has been made, especially in synthetic methods for particular halogen-substituted key intermediates that were previously prohibitively expensive. Interestingly, there has been a rise in the number of commercial products containing 'mixed' halogens, e.g. one or more fluorine, chlorine, bromine or iodine atoms in addition to one or more further halogen atoms. Extrapolation of the current trend indicates that a definite growth is to be expected in fluorine-substituted agrochemicals throughout the twenty-first century. A number of these recently developed agrochemical candidates containing halogen substituents represent novel classes of chemical compounds with new modes of action. However, the complex structure-activity relationships associated with biologically active molecules mean that the introduction of halogens can lead to either an increase or a decrease in the efficacy of a compound, depending on its changed mode of action, physicochemical properties, target interaction or metabolic susceptibility and transformation. In spite of modern design concepts, it is still difficult to predict the sites in a molecule at which halogen substitution will result in optimal desired effects. This review describes comprehensively the successful utilisation of halogens and their unique role in the design of modern agrochemicals, exemplified by various commercial products from Bayer CropScience coming from different agrochemical areas.

  6. Bibliography about silicon non-organic fluorine compounds

    International Nuclear Information System (INIS)

    Carles, M.

    1963-01-01

    This bibliography is made from Professor I.G. Ryss' book published in Moscow in 1956, translated in English under the title 'The chemistry of fluorine and its inorganic compounds' (Translation series. AEC tr 3927, Pt 1 and 2), and completed with the data found in the 'Chemical Abstracts' of the years 1946 to 1962 [fr

  7. Removal of Intermediate Aromatic Halogenated DBPs by Activated Carbon Adsorption: A New Approach to Controlling Halogenated DBPs in Chlorinated Drinking Water.

    Science.gov (United States)

    Jiang, Jingyi; Zhang, Xiangru; Zhu, Xiaohu; Li, Yu

    2017-03-21

    During chlorine disinfection of drinking water, chlorine may react with natural organic matter (NOM) and bromide ion in raw water to generate halogenated disinfection byproducts (DBPs). To mitigate adverse effects from DBP exposure, granular activated carbon (GAC) adsorption has been considered as one of the best available technologies for removing NOM (DBP precursor) in drinking water treatment. Recently, we have found that many aromatic halogenated DBPs form in chlorination, and they act as intermediate DBPs to decompose and form commonly known DBPs including trihalomethanes and haloacetic acids. In this work, we proposed a new approach to controlling drinking water halogenated DBPs by GAC adsorption of intermediate aromatic halogenated DBPs during chlorination, rather than by GAC adsorption of NOM prior to chlorination (i.e., traditional approach). Rapid small-scale column tests were used to simulate GAC adsorption in the new and traditional approaches. Significant reductions of aromatic halogenated DBPs were observed in the effluents with the new approach; the removals of total organic halogen, trihalomethanes, and haloacetic acids by the new approach always exceeded those by the traditional approach; and the effluents with the new approach were considerably less developmentally toxic than those with the traditional approach. Our findings indicate that the new approach is substantially more effective in controlling halogenated DBPs than the traditional approach.

  8. Binary systems solubilities of inorganic and organic compounds, v.1 pt.2

    CERN Document Server

    Stephen, H

    2013-01-01

    Solubilities of Inorganic and Organic Compounds, Volume 1: Binary Systems, Part 1 is part of an approximately 5,500-page manual containing a selection from the International Chemical Literature on the Solubilities of Elements, Inorganic Compounds, Metallo-organic and Organic Compounds in Binary, Ternary and Multi-component Systems. A careful survey of the literature in all languages by a panel of scientists specially appointed for the task by the U.S.S.R. Academy of Sciences, Moscow, has made the compilation of this work possible. The complete English edition in five separately bound volumes w

  9. Prediction of Partition Coefficients of Organic Compounds for SPME/PDMS

    Directory of Open Access Journals (Sweden)

    Liao Hsuan-Yu

    2016-01-01

    Full Text Available The partition coefficients of 51 organic compounds between SPME/PDMS and gas were compiled from the literature sources in this study. The effect of physicochemical properties and descriptors on the partitioning process of partition coefficients was explicated by the correlation analysis. The PDMS-gas partition coefficients were well correlated to the molecular weight of organic compounds (r = 0.832, p < 0.05. An empirical model, consisting of the molecular weight and the polarizability, was developed to appropriately predict the partition coefficients of organic compounds. The empirical model for estimating the PDMS-gas partition coefficient will contribute to the practical applications of the SPME technique.

  10. Prediction of acid dissociation constants of organic compounds using group contribution methods

    DEFF Research Database (Denmark)

    Zhou, Teng; Jhamb, Spardha; Liang, Xiaodong

    2018-01-01

    data-points with average absolute error of 0.23; (b) a non-linear GC model for organic compounds using 1622 data-points with average absolute error of 1.18; (c) an artificial neural network (ANN) based GC model for the organic compounds with average absolute error of 0.17. For each of the developed......In this paper, group contribution (GC) property models for the estimation of acid dissociation constants (Ka) of organic compounds are presented. Three GC models are developed to predict the negative logarithm of the acid dissociation constant pKa: (a) a linear GC model for amino acids using 180...

  11. Differential effects of organic compounds on cucumber damping-off and biocontrol activity of antagonistic bacteria

    DEFF Research Database (Denmark)

    Li, Bin; Ravnskov, Sabine; Guanlin, X.

    2011-01-01

    The influence of the organic compounds tryptic soy broth, cellulose, glucose and chitosan on cucumber damping-off caused by Pythium aphanidermatum and biocontrol efficacy of the biocontrol agents (BCAs) Paenibacillus macerans and P. polymyxa were examined in a seedling emergence bioassay. Results...... showed that the organic compounds differentially affected both pathogen and BCAs. Tryptic soy broth, glucose and chitosan increased Pythium damping-off of cucumber, compared to the control treatment without organic compounds, whereas cellulose had no effect. Both Paenibacillus species had biocontrol...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    a color difference map which gives a unique fingerprint for each explosive and volatile organic compound. Such sensing technology can be used to screen for relevant explosives in a complex background as well as to distinguish mixtures of volatile organic compounds distributed in gas phase. This sensor......In the framework of the research project 'Xsense' at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT and TNT, and identification of volatile organic compounds in the presence of water vapor in air...

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

    Science.gov (United States)

    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.

  14. Organic compounds and suspended matter in the White Sea snow-ice cover

    International Nuclear Information System (INIS)

    Nemirovskaya, I.; Shevchenko, V.

    2008-01-01

    The pollution of the White Sea snow-ice cover was estimated by examining the distribution of organic compounds, including oil and pyrogenic hydrocarbons. Ice and snow cores were taken from Chupa Bay and the Kandalaksha Gulf in the Cape Kartesh area in the spring of 2004 and from the mouth of the Severnaya Dvina River in the spring of 2005, 2006, and 2007. This paper presented data on the lipid content, aliphatic hydrocarbons (AHC), polycyclic aromatic hydrocarbons (PAH) and suspended particulate matter in snow, ice and under-ice water. This paper focused on organic compounds and suspended matter (SM) concentrations in the sea snow-ice cover and described the ice forming conditions and interactions of the substances with ice, snow and sub-ice water. The amount of particulate matter and organic compounds in the snow increased sharply near industrial centres. The concentration of compounds decreased further away from these centres, suggesting that most pollutants are deposited locally. The study revealed that organic compounds concentrate in barrier zones, such as snow-ice and water-ice, depending on the source of pollution. There was no obvious evidence of petrogenic sources of PAHs in particulate matter from the White Sea snow-ice cover. The SM and organic compounds accumulated in layers characterized by local depositional processes. The zones remained biogeochemically active even under low temperature conditions, but the accumulation of both SM and organic compounds was at its highest during the initial stage of ice formation. 16 refs., 2 tabs., 4 figs

  15. SYNTHESIS AND STUDY OF HALOGENATED BENZYLAMIDES OF SOME ISOCYCLIC AND HETEROCYCLIC ACIDS AS POTENTIAL ANTICONVULSANTS.

    Science.gov (United States)

    Strupińska, Marzanna; Rostafińska-Suchar, Grażyna; Pirianowicz-Chaber, Elżbieta; Grabczuk, Mateusz; Józwenko, Magdalena; Kowalczyk, Hubert; Szuba, Joanna; Wójcicka, Monika; Chen, Tracy; Mazurek, Aleksander P

    2015-01-01

    A series of potential anticonvulsants have been synthesized. There are eight fluorobenzylamides and three chlorobenzylamides of isocyclic or heterocyclic acids. Two not halogenated benzylamides were also synthesized to compare the effect of halogenation. The aim of the research performed was to evaluate whether halogenation of the mother structure is able to improve its anticonvulsant activity. The compounds were tested in Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Compound 1 showed MES ED50 = 80.32 mg/kg, PI = 3.16. Compound 7 showed CKM ED50 = 56.72 mg/kg. Compound 8 showed MES ED50 = 34.23 mg/kg and scPTZ ED50 > 300 mg/kg, PI = 8.53.Compound 13 showed 6Hz ED50 = 78.96, PI = 3.37. The results indicate that fluorination does not improve activity, whereas chlorination in our experiment even reduces it.

  16. Capillary electrophoretic separation of inorganic and organic arsenic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Greschonig, H. [Institute of Analytical Chemistry, Karl Franzens University Graz (Austria); Schmid, M.G.; Guebitz, G. [Institute of Pharmaceutical Chemistry, Karl Franzens University Graz (Austria)

    1998-09-01

    Capillary zone electrophoresis was used to separate arsenite, arsenate, dimethylarsinic and diphenylarsinic acid, methanearsonic acid, phenyl- and p-aminophenyl arsonic acid, phenylarsineoxide and phenarsazinic acid. Anionic and uncharged species were separated in a fused silica capillary with on-column UV detection at 200 nm. A 15 mM phosphate solution adjusted to pH 6.5 containing 10 mM sodium dodecylsulfonate served as background electrolyte. The influence of pH and applied voltage on separation efficiency, as well as the feasibility of identification of arsenic compounds in spiked urine, were investigated. (orig.) With 7 figs., 1 tab., 22 refs.

  17. Atmospheric chemistry of organic sulfur and nitrogen compounds

    International Nuclear Information System (INIS)

    Nielsen, O.J.; Sidebottom, H.W.; Treacy, J.J.

    1988-12-01

    The work carried out during the first year of a four year Danish-Irish contract with the European Economic Community is described. The reactions of OH radicals with dialkyl sulfides and nitroalkanes have been studied applying both an absolute technique of pulse radiolysis with kinetic spectroscopy and a relative rate method using conventional smog chamber facilities. The reactions of OH with dimethyl sulfide and nitromethane have been investigated in special detail. Rate constants for reaction of Cl atoms with the same compounds have been determing using the relative rate method. (author)

  18. Selective C-H Halogenation with a Highly Fluorinated Manganese Porphyrin.

    Science.gov (United States)

    Li, Gang; Dilger, Andrew K; Cheng, Peter T; Ewing, William R; Groves, John T

    2018-01-26

    The selective C-H functionalization of aliphatic molecules remains a challenge in organic synthesis. While radical chain halogenation reactions provide efficient access to many halogenated molecules, the use of typical protocols for the selective halogenation of electron-deficient and strained aliphatic molecules is rare. Herein, we report selective C-H chlorination and fluorination reactions promoted by an electron-deficient manganese pentafluorophenyl porphyrin catalyst, Mn(TPFPP)Cl. This catalyst displays superior properties for the aliphatic halogenation of recalcitrant, electron-deficient, and strained substrates with unique regio- and stereoselectivity. UV/Vis analysis during the course of the reaction indicated that an oxo-Mn V species is responsible for hydrogen-atom abstraction. The observed stereoselectivity results from steric interactions between the bulky porphyrin ligand and the intermediate substrate radical in the halogen rebound step. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Dissolved organic carbon enhances the mass transfer of hydrophobic organic compounds from Nonaqueous Phase Liquids (NAPLs) into the aqueous phase

    NARCIS (Netherlands)

    Smith, K.E.C.; Thullner, M.; Wick, L.Y.; Harms, H.

    2011-01-01

    The hypothesis that dissolved organic carbon (DOC) enhances the mass transfer of hydrophobic organic compounds from nonaqueous phase liquids (NAPLs) into the aqueous phase above that attributable to dissolved molecular diffusion alone was tested. In controlled experiments, mass transfer rates of

  20. 75 FR 57390 - Approval and Promulgation of Implementation Plans; Alabama: Volatile Organic Compounds

    Science.gov (United States)

    2010-09-21

    ... Environmental Management (ADEM) on March 3, 2010. The revision modifies the definition of ``volatile organic... the VOC definition on the basis that these compounds make a negligible contribution to tropospheric..., 2009, which excludes these compounds from the regulatory VOC definition. This action is being taken...

  1. Destructive hydrogenation; dehydrogenation and dehydrogenation processes; purifying oils; polynuclear organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    1934-02-08

    Unitary organic compounds containing four or more nuclei are recovered from the high boiling fractions of destructive hydrogenation products of bituminous, resinous, or ligneous materials. Cooling, precipitation, crystallization, selective dissolution and distillation are some of the techniques discussed. These techniques may also be applied to the recovery of polynuclear compounds.

  2. Volatile organic compounds and Photobacterium phosphoreum associated with spoilage of modified-atmosphere-packaged raw pork

    DEFF Research Database (Denmark)

    Nieminen, Timo T.; Dalgaard, Paw; Björkroth, Johanna

    2016-01-01

    Accumulation of volatile organic compounds was monitored in association with sensory quality, bacterial concentrations and culture-independent microbial community analyses in raw pork loin and pork collar during storage under high-oxygen modified atmosphere at +4°C. Of the 48 volatile compounds...

  3. Risk assessment for halogenated solvents

    International Nuclear Information System (INIS)

    Travis, C.C.

    1988-01-01

    A recent development in the cancer risk area is the advent of biologically based pharmacokinetic and pharmacodynamic models. These models allow for the incorporation of biological and mechanistic data into the risk assessment process. These advances will not only improve the risk assessment process for halogenated solvents but will stimulate and guide basic research in the biological area

  4. Genetic effects of organic mercury compounds. II. Chromosome segregation in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Ramel, C; Magnusson, J

    1969-01-01

    The genetic effect of organic mercury compounds on the fruit fly, Drosophila melanogaster was investigated. Treatments of larvae with methyl and phenyl mercury gave rise to development disturbances. Chromosomal abnormalities were noted.

  5. Isotopic Constraints on the Sources and Associations of Organic Compounds in Marine Sediments

    National Research Council Canada - National Science Library

    White, Helen K

    2006-01-01

    .... The main objective has been to determine the significance of these associations, and to assess how they affect the transport, bioavailability, preservation and residence times of organic compounds in the environment...

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  7. Abstracts of the papers presented at the workshop 'synthesis and application of radioactively labelled organic compounds'

    International Nuclear Information System (INIS)

    1988-10-01

    The abstracts of the 12 papers read at the Rossendorf workshop comprise syntheses and radioactive labelling of organic compounds such as herbicides, steroids, peptides and others and their application as tracers, above all in kinetic studies

  8. Occurrence and Distribution of Pharmaceutical Organic Compounds in the Groundwater Downgradient of a Landfill (Grindsted, Denmark)

    DEFF Research Database (Denmark)

    Holm, John V.; Rügge, Kirsten; Bjerg, Poul Løgstrup

    1995-01-01

    Usually landfill leachates contain specific organic compounds as BTEXs (benzene, toluene, ethylbenzene, and xylenes), chlorinated aliphatic hydrocarbons and chlorobenzenes originating from household chemicals and waste from small businesses (I). However, where industrial waste has been landfilled...

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

    NARCIS (Netherlands)

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

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

  10. Plant-associated bacterial degradation of toxic organic compounds in soil.

    LENUS (Irish Health Repository)

    McGuinness, Martina

    2009-08-01

    A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review.

  11. The Study and Development of Metal Oxide Reactive Adsorbents for the Destruction of Toxic Organic Compounds

    National Research Council Canada - National Science Library

    Mitchell, Mark B

    2008-01-01

    ... and other toxic organic compounds. The research program that was developed built upon earlier results achieved in the room temperature oxidative decomposition of a chemical warfare agent simulant, dimethyl methylphosphonate (DMMP...

  12. PREDICTION OF THE VAPOR PRESSURE, BOILING POINT, HEAT OF VAPORIZATION AND DIFFUSION COEFFICIENT OF ORGANIC COMPOUNDS

    Science.gov (United States)

    The prototype computer program SPARC has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC solute-solute physical process models have been developed and tested...

  13. Halogen bonding in solution: thermodynamics and applications.

    Science.gov (United States)

    Beale, Thomas M; Chudzinski, Michael G; Sarwar, Mohammed G; Taylor, Mark S

    2013-02-21

    Halogen bonds are noncovalent interactions in which covalently bound halogens act as electrophilic species. The utility of halogen bonding for controlling self-assembly in the solid state is evident from a broad spectrum of applications in crystal engineering and materials science. Until recently, it has been less clear whether, and to what extent, halogen bonding could be employed to influence conformation, binding or reactivity in the solution phase. This tutorial review summarizes and interprets solution-phase thermodynamic data for halogen bonding interactions obtained over the past six decades and highlights emerging applications in molecular recognition, medicinal chemistry and catalysis.

  14. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also...

  15. Lifetimes of organic photovoltaics: photooxidative degradation of a model compound

    DEFF Research Database (Denmark)

    Norrman, K.; Alstrup, J.; Jørgensen, M.

    2006-01-01

    A poly phenylene vinylene (PPV-type) oligomer used in organic photovoltaics was designed to facilitate the interpretation of mass spectral data. A film of the oligomer was subjected to various degrees of illumination (1000 W m(-2), AM1.5) in air resulting in photooxidation of the material...

  16. Adsorption of Volatile Organic Compounds from Aqueous Solution by Granular Activated Carbon in Batch System

    International Nuclear Information System (INIS)

    Zeinali, F.; Ghoreyshi, A. A.; Najafpour, G.

    2011-01-01

    Chlorinated hydrocarbons and aromatics are the major volatile organic compounds that contaminate the ground water and industrial waste waters. The best way to overcome this problem is to recover the dissolved compounds in water. In order to evaluate the potential ability of granular activated carbon for recovery of volatile organic compounds from water, the equilibrium adsorption was investigated. This study deals with the adsorption of dichloromethane as a typical chlorinated volatile organic compound and toluene as the representative of aromatic volatile organic compounds on a commercial granular activated carbon. The adsorption isotherms of these two volatile organic compounds on granular activated carbon were measured at three different temperatures, toluene at 293, 303 and 313 K and dichloromethane at 298, 303 and 313 K within their solubility concentration range in water. The maximum adsorption capacity of dichloromethane and toluene adsorption by granular activated carbon was 4 and 0.2 mol/Kg-1, respectively. The experimental data obtained were correlated with different adsorption isotherm models. The Langmuir model was well adapted to the description of dichloromethane adsorption on granular activated carbon at all three temperatures, while the adsorption of toluene on granular activated carbon was found to be well described by the Langmuir-BET hybrid model at all three temperatures. The heat of adsorption was also calculated based on the thermodynamic equation of Clausius Clapeyron, which indicates the adsorption process is endothermic for both compounds.

  17. Studies on the biological effects of deuteriated organic compounds

    International Nuclear Information System (INIS)

    Dinh-Nguyen, Nguyen; Vincent, J.

    1976-01-01

    The antifungal activity of some perdeuterated fatty acids with a normal chain of 11 to 18 carbon atoms was investigated on common dermatophytes Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum under in vitro conditions. A perdeuterated compound is one in which most of the hydrogen atoms in the molecule are replaced by deuterium. These studies were performed by the dilution technique with respiratory measurements. Perdeuteration of of some fatty acids increases their inhibitory effect on the dermatophyte growth. Perdeuterated n-hendecanoic acid proved to be the most active of the substances tested. Possible mechanisms behind the enhanced antifungal activity due to the perdeuteration of fatty acids are discussed. The present study investigates the antifungal properties of some perdeuterated fatty acids on dermatophytes in vitro

  18. Erythrocyte hemolysis by organic tin and lead compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kleszcynska, H. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Hladyszowski, J. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Pruchnik, H. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics; Przestalski, S. [Agricultural Univ., Wroclaw (Poland). Dept. of Physics and Biophysics

    1997-01-01

    The effect of trialkyllead and trialkyltin on pig erythrocyte hemolysis has been studied and compared. The results of experiments showed that the hemolytic activity of organoleads increases with their hydrophobicity and follows the sequence: triethyllead chloride < tri-n-propyllead chloride < tributyllead chloride. And similarly in the case of organotins: triethyltin chloride < tri-n-propyltin chloride < tributyltin chloride. Comparison of the hemolytic activity of organoleads and organotins indicates that the lead compounds exhibit higher hemolytic activity. The methods of quantum chemistry allowed to determine the maximum electric potential of the ions R{sub 3}Pb{sup +} and R{sub 3}Sn{sup +}, and suggest a relationship between the potential and toxicity. (orig.)

  19. Maximizing Information from Residential Measurements of Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Li, Na [Berkeley Analytical Associates, Richmond, CA (United States); Hodgson, Alfred [Berkeley Analytical Associates, Richmond, CA (United States); Offermann, Francis [Indoor Environmental Engineering, San Francisco, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-02-01

    Continually changing materials used in home construction and finishing can introduce new chemicals or changes in the VOC profile in residential air and the trend towards tighter homes can lead to higher exposure concentrations for many indoor sources. However, the complex mixture of VOCs in residential air makes it difficult to discover emerging contaminants and/or trends in pollutant profiles. The purpose of this study is to prepare a comprehensive library of chemicals found in homes, along with a semi-quantitative approach to maximize the information gained from VOC measurements. We carefully reviewed data from 108 new California homes and identified 238 individual compounds. The majority of the identified VOCs originated indoors. Only 31% were found to have relevant health based exposure guidelines and less than 10% had a chronic reference exposure level (CREL). The finding highlights the importance of extending IAQ studies to include a wider range of VOCs

  20. New methods of arene iodination and functional transformation of multiple bonds in organic compounds

    International Nuclear Information System (INIS)

    Filimonov, V.D.; Chajkovskij, V.K.; Krasnokutskaya, E.A.

    2000-01-01

    The review summarizes the latest results of organic chemistry and technology of organic synthesis department of Tomsk polytechnical university concerning iodination of arenes and chemical transformations of unsaturated compounds. Preparative possibilities of the new reactions and reagents for iodination, oxidation of alkenes and alkynes to 1,2- and bis-1,2-dicarbonyl compounds, iodonitration of alkynes, and reaction of oxidative dimerization of the terminal alkynes to unsaturated δ-sultones are discussed [ru

  1. Prediction of Partition Coefficients of Organic Compounds for SPME/PDMS

    OpenAIRE

    Liao Hsuan-Yu; Huang Miao-Ling; Lu Yu-Ting; Chao Keh-Ping

    2016-01-01

    The partition coefficients of 51 organic compounds between SPME/PDMS and gas were compiled from the literature sources in this study. The effect of physicochemical properties and descriptors on the partitioning process of partition coefficients was explicated by the correlation analysis. The PDMS-gas partition coefficients were well correlated to the molecular weight of organic compounds (r = 0.832, p < 0.05). An empirical model, consisting of the molecular weight and the polarizability, was ...

  2. Biogenic, urban, and wildfire influences on the molecular composition of dissolved organic compounds in cloud water

    Science.gov (United States)

    Cook, Ryan D.; Lin, Ying-Hsuan; Peng, Zhuoyu; Boone, Eric; Chu, Rosalie K.; Dukett, James E.; Gunsch, Matthew J.; Zhang, Wuliang; Tolic, Nikola; Laskin, Alexander; Pratt, Kerri A.

    2017-12-01

    Organic aerosol formation and transformation occurs within aqueous aerosol and cloud droplets, yet little is known about the composition of high molecular weight organic compounds in cloud water. Cloud water samples collected at Whiteface Mountain, New York, during August-September 2014 were analyzed by ultra-high-resolution mass spectrometry to investigate the molecular composition of dissolved organic carbon, with a focus on sulfur- and nitrogen-containing compounds. Organic molecular composition was evaluated in the context of cloud water inorganic ion concentrations, pH, and total organic carbon concentrations to gain insights into the sources and aqueous-phase processes of the observed high molecular weight organic compounds. Cloud water acidity was positively correlated with the average oxygen : carbon ratio of the organic constituents, suggesting the possibility for aqueous acid-catalyzed (prior to cloud droplet activation or during/after cloud droplet evaporation) and/or radical (within cloud droplets) oxidation processes. Many tracer compounds recently identified in laboratory studies of bulk aqueous-phase reactions were identified in the cloud water. Organosulfate compounds, with both biogenic and anthropogenic volatile organic compound precursors, were detected for cloud water samples influenced by air masses that had traveled over forested and populated areas. Oxidation products of long-chain (C10-12) alkane precursors were detected during urban influence. Influence of Canadian wildfires resulted in increased numbers of identified sulfur-containing compounds and oligomeric species, including those formed through aqueous-phase reactions involving methylglyoxal. Light-absorbing aqueous-phase products of syringol and guaiacol oxidation were observed in the wildfire-influenced samples, and dinitroaromatic compounds were observed in all cloud water samples (wildfire, biogenic, and urban-influenced). Overall, the cloud water molecular composition depended on

  3. Removal of volatile organic compounds by a high pressure microwave plasma torch

    International Nuclear Information System (INIS)

    Rubio, S.J.; Quintero, M.C.; Rodero, A.; Alvarez, R.

    2004-01-01

    A helium microwave plasma torch was studied and optimised as a destruction system of volatile organic compounds. Attention was focused on trichloroethylene as a prototypical volatile organic compound, which is used technologically and which poses known health risks. The dependence of the destruction efficiency on the plasma conditions was obtained for different values of trichloroethylene concentrations. The results show a destruction and removal efficiency greater than 99.999% (Authors)

  4. Analysis of volatile organic compounds of ‘Fuji’ apples following electron beam irradiation and storage

    International Nuclear Information System (INIS)

    Song, Hyun-Pa; Shim, Sung-Lye; Lee, Sun-Im; Kim, Dong-Ho; Kwon, Joong-Ho; Kim, Kyong-Su

    2012-01-01

    The volatile organic compounds of non-irradiated and electron-beam irradiated ‘Fuji’ apples (Malus domestica Borkh.) at 0, 0.5, and 1 kGy were isolated through simultaneous distillation extractions and analyzed using gas chromatograph–mass spectrometry. A total of 53 volatile organic compounds were characterized in 0 and 1 kGy irradiated samples, whereas two more compounds related to ketone and terpenoid group were identified in 0.5 kGy irradiated samples. The contents of volatile compounds were 24.33, 36.49, and 35.28 mg/kg in 0, 0.5, and 1 kGy irradiated samples, respectively. The major compounds identified were butanol, hexanal, [E]-2-hexenal, and hexanol in all samples. The relative content of alcohol increased after 30 days of storage in all samples, whereas that of aldehyde decreased. Although the contents of some volatile compounds were changed by electron-beam irradiation, the total yield and major flavor compounds of irradiated ‘Fuji’ apples were similar to, or even greater than, those of the control. Therefore, the application of e-beam irradiation if required for microbial decontamination of ‘Fuji’ apples is an acceptable method as it does not bring about any major quantitative changes of volatile organic compounds. - Highlights: ► We analyzed the volatile organic compounds of electron beam irradiated Fuji apples. ► The major compounds of samples were butanol, hexanal, [E]-2-hexenal, and hexanol. ► The contents of major flavor compounds of non-irradiated and irradiated samples were similar.

  5. Adsorption of volatile organic compounds by polytetra-fluor ethylene

    International Nuclear Information System (INIS)

    Martinet, J.M.

    1958-01-01

    The sorption of organic vapours by microporous polytetra-fluor ethylene has been studied gravimetrically using a Mc Bain-Baker type sorption balance. The amount of sorption, the peculiarities observed on the isotherm curves, the small influence of temperature, and smallness of hysteresis suggests that mainly physical adsorption occurs when the temperature is around 25 deg. C. The values of the surface areas obtained from the adsorption isotherms using organic vapours differ greatly from those derived from N 2 adsorption measurements. This discrepancy cannot be completely attributed to differences in the structure and chemical function of the adsorbate molecules, or to the porous structure of the adsorbent. On the contrary, the surface area values obtained by sorbing high volatile freons conform with those measured by nitrogen adsorption, which seems to imply a connection between the area of sorbed monolayers and volatility of the adsorbate. (author) [fr

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

    Science.gov (United States)

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

    2017-02-01

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

  7. Organic compound materials used as pipes reinforcement of fluids conduction

    International Nuclear Information System (INIS)

    Latorre, G; Vargas, F

    1999-01-01

    This paper presents the experimental test and the results of the development of a composite organic material (MCO) for the reinforcement and covering of pipelines. MCO is designed to be applied to pipelines with external, damages such as dents or gauges or with surface damages caused by corrosion; The product can recover transport lines with 65% thickness losses due to corrosion in lengths of less than 0,2 m. the system developed by ECOPETROL-ICP can stop progressive picking corrosion, it has an excellent capillary, good adhesion, good resistance in cathodic protection, and mechanical strength that can support the operational pressure of the pipeline. MCO is a mixture of a polymeric resin reinforced with organic fibers, it can be applied to surface or underground pipelines without stopping normal operation. The maximum rupture pressure attained by the MCO was 23,4 MPA in pipelines with a 65% thickness loss due to corrosion. The normal operation pressure is 10-12 MPA

  8. The Photocatalytic Destruction of Volatile Organic Compounds in Water

    Science.gov (United States)

    1991-12-10

    some common oxidants. It can be seen that the hydroxyl radical is only second to the fluorine ion in oxidation potential. 5 Table 2.1 Dissociation...Potential of Oxidants (Bernardin, 1991) Relative Oxidation Oxidative Power, Chlorine = 1 Species Potential (volts) 2.23 Fluorine 3.03 2.06 Hydroxyl... varnishes . It is used as a universal degreaser, in drycleaning, and in the manufacture of organic chemicals. On military bases it is used as a universal

  9. Halogen-Mediated Conversion of Hydrocarbons to Commodities.

    Science.gov (United States)

    Lin, Ronghe; Amrute, Amol P; Pérez-Ramírez, Javier

    2017-03-08

    Halogen chemistry plays a central role in the industrial manufacture of various important chemicals, pharmaceuticals, and polymers. It involves the reaction of halogens or halides with hydrocarbons, leading to intermediate compounds which are readily converted to valuable commodities. These transformations, predominantly mediated by heterogeneous catalysts, have long been successfully applied in the production of polymers. Recent discoveries of abundant conventional and unconventional natural gas reserves have revitalized strong interest in these processes as the most cost-effective gas-to-liquid technologies. This review provides an in-depth analysis of the fundamental understanding and applied relevance of halogen chemistry in polymer industries (polyvinyl chloride, polyurethanes, and polycarbonates) and in the activation of light hydrocarbons. The reactions of particular interest include halogenation and oxyhalogenation of alkanes and alkenes, dehydrogenation of alkanes, conversion of alkyl halides, and oxidation of hydrogen halides, with emphasis on the catalyst, reactor, and process design. Perspectives on the challenges and directions for future development in this exciting field are provided.

  10. Non-classical structures of organic compounds: unusual stereochemistry and hypercoordination

    International Nuclear Information System (INIS)

    Minkin, Vladimir I; Minyaev, Ruslan M; Hoffmann, Roald

    2002-01-01

    Non-classical structures of organic compounds are defined as molecules containing non-tetrahedral tetracoordinate and/or hypercoordinate carbon atoms. The evolution of the views on this subject is considered and the accumulated theoretical and experimental data on the structures and dynamic transformations of non-classical organic compounds are systematised. It is shown that computational analysis using the methods and the software potential of modern quantum chemistry has now acquired high predictive capacity and is the most important source of data on the structures of non-classical compounds. The bibliography includes 227 references.

  11. Using the properties of organic compounds to help design a treatment system

    International Nuclear Information System (INIS)

    Nyer, E.; Boettcher, G.; Morello, B.

    1991-01-01

    The author provides the physical/chemical and treatability properties of 50 organic compounds. The physical/chemical parameters of the compounds can be used to help evaluate data generated during remedial investigations. The treatability parameters can be used as a basis for the preliminary design of a treatment system that will remove organic compounds from ground water. The main physical/chemical properties that should be evaluated prior to design are solubility, specific gravity, and octanol/water coefficient. Based on this determination, the treatability is determined for carbon adsorption and biodegradability

  12. Graphene and graphene nanocomposites for the removal of aromatic organic compounds from the water: systematic review

    Science.gov (United States)

    Monsores Paixão, Monique; Tadeu Gomes Vianna, Marco; Marques, Marcia

    2018-01-01

    Aromatic organic pollutants are highly toxic to the human and environmental health and are considered as priority pollutants by regulatory agencies. Managing contaminated sites with organic pollutants is one of the major environmental challenges today. Of all technologies that have been proposed to remove contaminants, adsorption is recognized worldwide as an attractive option due to its versatility, wide applicability and economic viability. Recent studies report the use of graphene (GN), a recently carbon nanomaterial, and its derivatives in sorption processes for the removal of aromatic organic compounds. The present review has shown that GN structures are a promising alternative to traditional adsorbent materials, with excellent results in the removal of organic compounds from water, due to their unique structural characteristics and great adsorption capacity for organic compounds. Although, there is still a long way to go until that practical applications can be implemented.

  13. Detecting and Eliminating Interfering Organic Compounds in Waters Analyzed for Isotopic Composition by Crds

    Science.gov (United States)

    Richman, B. A.; Hsiao, G. S.; Rella, C.

    2010-12-01

    Optical spectroscopy based CRDS technology for isotopic analysis of δD and δ18O directly from liquid water has greatly increased the number and type of liquid samples analyzed. This increase has also revealed a previously unrecognized sample contamination problem. Recently West[1] and Brand[2] identified samples containing ethanol, methanol, plant extracts and other organic compounds analyzed by CRDS and other spectroscopy based techniques as yielding erroneous results for δD and δ18O (especially δD) due to spectroscopic interference. Not all organic compounds generate interference. Thus, identifying which samples are contaminated by which organic compounds is of key importance for data credibility and correction. To address this problem a new approach in the form of a software suite, ChemCorrect™, has been developed. A chemometrics component uses a spectral library of water isotopologues and interfering organic compounds to best fit the measured spectra. The best fit values provide a quantitative assay of the actual concentrations of the various species and are then evaluated to generate a visual flag indicating samples affected by organic contamination. Laboratory testing of samples spiked with known quantities of interfering organic compounds such as methanol, ethanol, and terpenes was performed. The software correctly flagged and identified type of contamination for all the spiked samples without any false positives. Furthermore the reported values were a linear function of actual concentration with an R^2>0.99 even for samples which contained multiple organic compounds. Further testing was carried out against a range of industrial chemical compounds which can contaminate ground water as well as a variety of plant derived waters and juices which were also analyzed by IRMS. The excellent results obtained give good insight into which organic compounds cause interference and which classes of plants are likely to contain interfering compounds. Finally

  14. Abiotic synthesis of organic compounds from carbon disulfide under hydrothermal conditions.

    Science.gov (United States)

    Rushdi, Ahmed I; Simoneit, Bernd R T

    2005-12-01

    Abiotic formation of organic compounds under hydrothermal conditions is of interest to bio, geo-, and cosmochemists. Oceanic sulfur-rich hydrothermal systems have been proposed as settings for the abiotic synthesis of organic compounds. Carbon disulfide is a common component of magmatic and hot spring gases, and is present in marine and terrestrial hydrothermal systems. Thus, its reactivity should be considered as another carbon source in addition to carbon dioxide in reductive aqueous thermosynthesis. We have examined the formation of organic compounds in aqueous solutions of carbon disulfide and oxalic acid at 175 degrees C for 5 and 72 h. The synthesis products from carbon disulfide in acidic aqueous solutions yielded a series of organic sulfur compounds. The major compounds after 5 h of reaction included dimethyl polysulfides (54.5%), methyl perthioacetate (27.6%), dimethyl trithiocarbonate (6.8%), trithianes (2.7%), hexathiepane (1.4%), trithiolanes (0.8%), and trithiacycloheptanes (0.3%). The main compounds after 72 h of reaction consisted of trithiacycloheptanes (39.4%), pentathiepane (11.6%), tetrathiocyclooctanes (11.5%), trithiolanes (10.6%), tetrathianes (4.4%), trithianes (1.2%), dimethyl trisulfide (1.1%), and numerous minor compounds. It is concluded that the abiotic formation of aliphatic straight-chain and cyclic polysulfides is possible under hydrothermal conditions and warrants further studies.

  15. The olefin metathesis reaction: reorganization and cyclization of organic compounds

    International Nuclear Information System (INIS)

    Frederico, Daniel; Brocksom, Ursula; Brocksom, Timothy John

    2005-01-01

    The olefin metathesis reaction allows the exchange of complex alkyl units between two olefins, with the formation of a new olefinic link and a sub-product olefin usually ethylene. This reaction has found extensive application in the last ten years with the development of the Grubbs and Schrock catalysts, in total synthesis of complex organic molecules, as opposed to the very important use in the petrochemical industry with relatively simple molecules. This review intends to trace a historical and mechanistic pathway from industry to academy, before illustrating the more recent advances. (author)

  16. Ozone variability and halogen oxidation within the Arctic and sub-Arctic springtime boundary layer

    Directory of Open Access Journals (Sweden)

    J. B. Gilman

    2010-11-01

    Full Text Available The influence of halogen oxidation on the variabilities of ozone (O3 and volatile organic compounds (VOCs within the Arctic and sub-Arctic atmospheric boundary layer was investigated using field measurements from multiple campaigns conducted in March and April 2008 as part of the POLARCAT project. For the ship-based measurements, a high degree of correlation (r = 0.98 for 544 data points collected north of 68° N was observed between the acetylene to benzene ratio, used as a marker for chlorine and bromine oxidation, and O3 signifying the vast influence of halogen oxidation throughout the ice-free regions of the North Atlantic. Concurrent airborne and ground-based measurements in the Alaskan Arctic substantiated this correlation and were used to demonstrate that halogen oxidation influenced O3 variability throughout the Arctic boundary layer during these springtime studies. Measurements aboard the R/V Knorr in the North Atlantic and Arctic Oceans provided a unique view of the transport of O3-poor air masses from the Arctic Basin to latitudes as far south as 52° N. FLEXPART, a Lagrangian transport model, was used to quantitatively determine the exposure of air masses encountered by the ship to first-year ice (FYI, multi-year ice (MYI, and total ICE (FYI+MYI. O3 anti-correlated with the modeled total ICE tracer (r = −0.86 indicating that up to 73% of the O3 variability measured in the Arctic marine boundary layer could be related to sea ice exposure.

  17. Short latency compound action potentials from mammalian gravity receptor organs

    Science.gov (United States)

    Jones, T. A.; Jones, S. M.

    1999-01-01

    Gravity receptor function was characterized in four mammalian species using far-field vestibular evoked potentials (VsEPs). VsEPs are compound action potentials of the vestibular nerve and central relays that are elicited by linear acceleration ramps applied to the cranium. Rats, mice, guinea pigs, and gerbils were studied. In all species, response onset occurred within 1.5 ms of the stimulus onset. Responses persisted during intense (116 dBSPL) wide-band (50 to 50 inverted question mark omitted inverted question mark000 Hz) forward masking, whereas auditory responses to intense clicks (112 dBpeSPL) were eliminated under the same conditions. VsEPs remained after cochlear extirpation but were eliminated following bilateral labyrinthectomy. Responses included a series of positive and negative peaks that occurred within 8 ms of stimulus onset (range of means at +6 dBre: 1.0 g/ms: P1=908 to 1062 micros, N1=1342 to 1475 micros, P2=1632 to 1952 micros, N2=2038 to 2387 micros). Mean response amplitudes at +6 dBre: 1.0 g/ms ranged from 0.14 to 0.99 microV. VsEP input/output functions revealed latency slopes that varied across peaks and species ranging from -19 to -51 micros/dB. Amplitude-intensity slopes also varied ranging from 0.04 to 0.08 microV/dB for rats and mice. Latency values were comparable to those of birds although amplitudes were substantially smaller in mammals. VsEP threshold values were considerably higher in mammals compared to birds and ranged from -8.1 to -10.5 dBre 1.0 g/ms across species. These results support the hypothesis that mammalian gravity receptors are less sensitive to dynamic stimuli than are those of birds.

  18. HS-SPME analysis of volatile organic compounds of coniferous needle litter

    Science.gov (United States)

    Isidorov, V. A.; Vinogorova, V. T.; Rafałowski, K.

    The composition of volatile emission of Scots pine ( Pinus sylvestris) and spruce ( Picea exelsa) litter was studied by gas chromatography-mass spectrometry (GC-MS) and samples were collected by solid-phase microextraction (SPME) method. The list of identified compounds includes over 60 organic substances of different classes. It was established that volatile emission contain not only components of essential oils of pine and spruce needles but also a large number of organic compounds which are probably secondary metabolites of litter-decomposing fungi. They include lower carbonyl compounds and alcohols as well as products of terpene dehydration and oxidation. These data show that the processes of litter decomposition are an important source of reactive organic compounds under canopy of coniferous forests.

  19. From energy-rich phosphate compounds to warfare agents: A review on the chemistry of organic phosphate compounds

    Directory of Open Access Journals (Sweden)

    Luciano Albino Giusti

    2008-12-01

    Full Text Available The chemistry of the phosphorus-oxygen bond is widely used in biological systems in many processes, such as energy transduction and the storage, transmission and expression of genetic information, which are essential to living beings in relation to a wide variety of functions. Compounds containing this bond have been designed for many purposes, ranging from agricultural defense systems, in order to increase food production, to nerve agents, for complaining use in warfare. In this review, features related to the chemistry of organic phosphate compounds are discussed, with particular emphasis on the role of phosphate compounds in biochemical events and in nerve agents. To this aim, the energy-rich phosphate compounds are focused, particularly the mode of their use as energy currency in cells. Historical and recent studies carried out by research groups have tried to elucidate the mechanism of action of enzymes responsible for energy transduction through the use of biochemical studies, enzyme models, and artificial enzymes. Finally, recent studies on the detoxification of nerve agents based on phosphorous esters are presented, and on the utilization of chromogenic and fluorogenic chemosensors for the detection of these phosphate species.

  20. Two new POMOF compounds constructed from polyoxoanions, metals and organic ligands

    Science.gov (United States)

    Xiao, Li-Na; Zhang, Hao; Zhang, Ting-Ting; Zhang, Xiao; Cui, Xiao-Bing

    2018-03-01

    Two new POMOF compounds, namely [PMo12V2O42][Cu3(4,4'-bpy)3]·(DABCO) (1) and [PMo10V4O42][Cu2(4,4'-bpy)2][Cu(phen)2]2 (2) (DABCO = triethylenediamine, bpy = bipyridine, phen = 1,10-phenanthroline)), have been synthesized and characterized by IR, UV-Vis, XRD, elemental analysis and X-ray diffraction analysis. Crystal structure analyses reveal that compounds 1 and 2 exhibit novel 2-D layered framework structures constructed from bi-capped Keggin molybdenum-vanadium polyoxoanions, metals and organic ligands, respectively. The main difference of the two compounds is that compound 2 contains both Cu2+ and Cu+ complexes. In addition, we also investigate the catalytic properties of the two compounds, both compound 1 and 2 are excellent catalysts for the epoxidation of styrene.

  1. Photocatalysis: A viable alternative for the elimination of organic compound

    International Nuclear Information System (INIS)

    Gil Pavas, Edison

    2002-01-01

    The basic idea of this project is to present photo catalysis as a simple, economic, effective and innovative technology, for the treatment of phenolic waters found in the effluents from several industrial processes, by determining the optimum conditions of operation and by identifying the parameters that govern the process. The attractiveness of this technology is based on its profitability, easy of implementation and use. The required capital investment is minimal in comparison with other technologies. The UV radiation from the sun or artificial sources (lamps) is used to activate the catalyst (TiO) to destroy the organic pollutants present in liquids effluent. The process was carried out continuously with using ph, catalyst (TiO 2 ) concentration and recirculation time as variables

  2. Radioluminescence of organic compounds: specific luminescence of condensed aromatic scintillators

    International Nuclear Information System (INIS)

    Lopes da Silva, J.

    1978-01-01

    The influence of the nature of ionizing particles on the radioluminescence yield of aromatic scintillators is studied. Both prompt and delayed scintillation components are considered. An expression giving the specific luminescence dS/dx as a function of the charge number z and of the incident particle specific energy loss have been derived, following a track model published before, that is consistent with recent conclusions about the nature, evolution and distribution of the primary excitations created by an ionizing particle in the organic scintillator. The good agreement between the theoretical curves derived in this paper and the experimental ones previously reported provided us with a means of evaluating the different parameters included in the proposed expressions. The numerical values of these parameters included in the proposed expressions. The numerical values of these parameters agree with those of other authors and are theoretically discussed and justified [fr

  3. Chlorine isn't Just for Swimming Pools Anymore... Chlorination of Organic Compounds in the Arctic

    Science.gov (United States)

    Han, A.; Raab, T. K.

    2013-12-01

    The cycling of chlorine between its organic and inorganic forms is known to occur in forest soils, but little is known about the generality of this mechanism, which soil components chlorine attaches to, and at what rate chlorination occurs. The study uses peat-rich tundra soils from Barrow, Alaska varying in age since formation of 50 yrs - 5500 yrs BP, and seeks to measure the rate at which organic molecules are chlorinated and to understand what changes those molecules undergo once chlorinated. Soil abundance of chlorine and bromine was estimated in soils of varying age using X-ray fluorescence, and org-Cl levels were measured using pyro-hydrolysis [Table 1]. We considered activity of the enzyme Chloroperoxidase, and data was gathered using absorbance scans of the organic molecule monochlorodimedone to determine whether it had been chlorinated and if so, at what rate. Additional information was gathered from the chlorination of small organic components of the macromolecule lignin, whose constituent molecules make up a large portion of humic materials critical to soil health, through emission scans and fluorescence scans. The results showed that the enzyme chloroperoxidase, which is found in nature and is associated with fungi or bacteria, attaches a chlorine atom to monochlorodimedone and that similar enzymes found in Arctic soils act on it, as well as the lignin model subunits cinnamaldehyde ((2E)-3-phenylprop-2-enal) and naringenin-7-rhamnoglucoside. The results may provide more information on chlorination rates in the Arctic and may contribute to an understanding of how and at what rate chlorine changes form in nature, and answer questions about ozone deterioration or anthropogenic chlorine impact(s) on the environment.Average Halogen Abundance in Arctic Soils xrf=Energy Dispersive X-Ray Fluorescencepyro= TOX Pyro-Hydrolysis

  4. Extraction of interesting organic compounds from olive oil waste

    Directory of Open Access Journals (Sweden)

    Jiménez, Ana

    2006-03-01

    Full Text Available In the olive fruits there is a large amount of bioactive compounds and substances of high interest. Many of them are known by owing health beneficial properties that contribute to protective effect of the virgin olive oil. During olive oil processing, most of them remain in the olive oil wastes. Although, olive-mill wastewater (OMWW or “alpechin”, olive oil cake (OOC, and the new by-product, known as “alperujo” in Spain and generated by the two-phase extraction process, represent a major disposal and potentially severe pollution problem for the industry, they are also promising source of substances of high value. This review summarises the last knowledge on the utilisation of residual products, with more than 90 references including articles and patents, which are promising with regard to future application. All these investigations have been classified into two options, the recovery of valuable natural constituents and the bioconversion into useful products.Existe una gran cantidad de compuestos bioactivos y de alto interés presentes en la aceituna. Muchos de ellos se conocen por las cualidades beneficiosas que aportan al aceite de oliva virgen. La mayoría permanecen en mayor cantidad en el subproducto de la extracción del aceite. Aunque, el alpechín, el orujo y el nuevo subproducto de extracción del aceite en dos fases, alperujo, representan un problema potencial de vertido y contaminación, también son una prometedora fuente de compuestos de alto valor. Esta revisión resume lo último que se conoce sobre la utilización de estos residuos en el campo anteriormente mencionado, con más de 90 referencias que incluyen artículos y patentes. Todas estas investigaciones han sido clasificadas en cuanto a la recuperación de constituyentes naturalmente presentes o en cuanto a la bioconversión de los residuos en sustancias de interés.

  5. Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

    Science.gov (United States)

    This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

  6. N-doping of organic semiconductors by bis-metallosandwich compounds

    Science.gov (United States)

    Barlow, Stephen; Qi, Yabing; Kahn, Antoine; Marder, Seth; Kim, Sang Bok; Mohapatra, Swagat K.; Guo, Song

    2016-01-05

    The various inventions disclosed, described, and/or claimed herein relate to the field of methods for n-doping organic semiconductors with certain bis-metallosandwich compounds, the doped compositions produced, and the uses of the doped compositions in organic electronic devices. Metals can be manganese, rhenium, iron, ruthenium, osmium, rhodium, or iridium. Stable and efficient doping can be achieved.

  7. Exploring the C-X…π Halogen Bonding Motif: An Infrared and Raman Study of the Complexes of CF3X (X = Cl, Br and I with the Aromatic Model Compounds Benzene and Toluene

    Directory of Open Access Journals (Sweden)

    Wouter A. Herrebout

    2013-06-01

    Full Text Available The formation of halogen bonded complexes formed between the trifluorohalomethanes CF3Cl, CF3Br and CF3I and the Lewis bases benzene and toluene at temperatures below 150K was investigated using FTIR and Raman spectroscopy. Experiments using liquid krypton as solvent show that for both CF3Br and CF3I substantial fractions of the monomers can be involved in 1:1 complexes. In addition, weak absorptions illustrating the formation of 2:1 complexes between CF3I and benzene are observed. Using spectra recorded at temperatures between 120 and 140 K, observed information on the relative stability was obtained for all complexes by determining the complexation enthalpies in solution. The resulting values for CF3Br.benzene, CF3I.benzene and (CF3I2.benzene are −6.5(3, −7.6(2 and −14.5(9 kJ mol−1. The values for CF3Br.toluene and CF3I.toluene are −6.2(5 and −7.4(5 kJ mol−1. The experimental complexation enthalpies are compared with theoretical data obtained by combining results from MP2/aug-cc-pVDZ(-PP and MP2/aug-cc-pVTZ(-PP ab initio calculations, from statistical thermodynamical calculations and from Monte Carlo Free Energy Perturbation simulations. The data are also compared with results derived for other C-X···π halogen bonded complexes involving unsaturated Lewis bases such as ethene and ethyne.

  8. Formation and evolution of point defects created in alkali halogen compounds irradiated by heavy ions; Formation et evolution des defauts ponctuels crees dans certains halogenures alcalins irradies par des ions lourds

    Energy Technology Data Exchange (ETDEWEB)

    Hourdequin, E [Nantes Univ., 44 (France)

    1993-07-16

    The goal of this study was to achieve a better understanding of the heavy-ion material interaction. Alkali halogen crystals were chosen since the color centers produced by heavy ions can be distinguished easier from those generated by X rays. Measurements on KI irradiated at low temperature showed that the usual process of non radiative de-excitation of self-captured exciton is not prevailing. As the main objective of this work was the exact determination of the defects created by accelerated heavy ions, an important effort was dedicated to the spectrum deconvolution. Due to the high quality of the obtained spectra the V band analyse was possible. The defect stability was found to have the same nature in all the cubical alkali halogens and depend essentially on the crystal type. The defect evolution after irradiation is related to the diffusion coefficients corresponding to each mobile species and to the crystal lattice in which they move. Based on measurements made at different temperatures a simple modeling of the recombination kinetics was proposed. This effect was found to be specific to irradiation by heavy ions. It is difficult to determine the initial processes from the fossil defects, so, the defect history must be known as the described investigation methods do not permit to establish the transient aspect of defect creation. The important role of impurities should be stressed as the third intruder in the ion/crystal configuration; it can modify significantly the final state of the irradiated crystal, as it was found in KI, for instance. The open problems underlined in this study will probably be solved by using the atomic force microscopy and diffraction or on-line Raman measurements in ISOC chamber to avoid the passage to ambient conditions of the crystals irradiated at low temperatures 60 refs.

  9. Hydrogen charging/discharging system with liquid organic compounds: a lacunar oxide catalyst to hydrogenate the unsaturated organic compound

    International Nuclear Information System (INIS)

    Jalowiecki-Duhamel, L.; Carpentier, J.; Payen, E.; Heurtaux, F.

    2006-01-01

    Lacunar mixed oxides based on cerium nickel and aluminium or zirconium CeM 0.5 Ni x O y s (M = Zr or Al), able to store high quantities of hydrogen, have been analysed in the hydrogenation of toluene into methyl-cyclohexane (MCH). When these solids present very good toluene hydrogenation activity and selectivity towards MCH in presence of H 2 , in absence of gaseous hydrogen, the reactive hydrogen species stored in the solid can hydrogenate toluene into MCH. The hydrogenation activity under helium + toluene flow decreases as a function of time and becomes nil. The integration of the curve obtained allows to determine the extractable hydrogen content of the solid used, and a value of 1.2 wt % is obtained at 80 C on a CeAl 0.5 Ni 3 O y compound pre-treated in H 2 at 300 C. To optimise the system, different parameters have been analysed, such as the catalyst formulation, the metal content, the pre-reducing conditions as well as the reaction conditions under helium + toluene. (authors)

  10. Biodegradation of organic compounds in vadose zone and aquifer sediments

    International Nuclear Information System (INIS)

    Konopka, A.; Turco, R.

    1991-01-01

    The microbial processes that occur in the subsurface under a typical Midwest agricultural soil were studied. A 26-m bore was installed in November of 1988 at a site of the Purdue University Agronomy Research Center. Aseptic collections of soil materials were made at 17 different depths. Physical analysis indicated that the site contained up to 14 different strata. The site materials were primarily glacial tills with a high carbonate content. The N,P, and organic C contents of sediments tended to decrease with depth. Ambient water content was generally less than the water content, which corresponds to a -0.3-bar equivalent. No pesticides were detected in slurry incubations of up to 128 days. The sorption of atrazine and metolachlor was correlated with the clay content of the sediments. Microbial biomass (determined by direct microscopic count, viable count, and phospholipid assay) in the tills was lower than in either the surface materials or the aquifer located at 25 m. The biodegradation of glucose and phenol occurred rapidly and without a lag in samples from the aquifer capillary fringe, saturated zone, and surface soils. In contrast, lag periods and smaller biodegradation rates were found in the till samples. Subsurface sediments are rich in microbial numbers and activity. The most active strata appear to be transmissive layers in the saturated zone. This implies that the availability of water may limit activity in the profile

  11. Development of technology performance specifications for volatile organic compounds

    International Nuclear Information System (INIS)

    Purdy, C.; Schutte, W.E.

    1993-01-01

    The Office of Technology Development (OTD) within the Office of Environmental Restoration and Waste Management of the Department of Energy has a mission to deliver needed and usable technologies to its customers. The primary customers are individuals and organizations performing environmental characterization and remediation, waste cleanup, and pollution prevention at DOE sites. DOE faces a monumental task in cleaning up the dozen or so major sites and hundreds of smaller sites that were or are used to produce the US nuclear weapons arsenal and to develop nuclear technologies for national defense and for peaceful purposes. Contaminants and waste materials include the radionuclides associated with nuclear weapons, such as plutonium and tritium, and more common pollutants and wastes of industrial activity such as chromium, chlorinated solvents, and polychlorinated biphenyls (PCBs). Quite frequently hazardous wastes regulated by the Environmental Protection Agency are co-mingled with radioactive wastes regulated by the Nuclear Regulatory Commission to yield a open-quotes mixed waste,close quotes which increases the cleanup challenges from several perspectives. To help OTD and its investigators meet DOE's cleanup goal, technology performance specifications are being implemented for research and development and DT ampersand E projects. Technology performance specifications or open-quotes performance goalsclose quotes describe, quantitatively where possible, the technology development needs being addressed. These specifications are used to establish milestones, evaluate the status of ongoing projects, and determine the success of completed projects

  12. Method for the detection and isolation of traces of organic fluorine compounds in plants

    Energy Technology Data Exchange (ETDEWEB)

    Wade, R H; Ross, J M; Benedict, H M

    1964-01-01

    A method for the detection and isolation of sub-microgram quantities of organic fluorine compounds from plant materials in the presence of much larger amounts of inorganic fluoride is presented. The procedure consists first of a rapid screening step for use with large numbers of vegetable samples and extracts and, second, of a chromatographic step to isolate and characterize any fluoro-organics found. These methods are developed in light of specific chemical characteristics of organic fluorine compounds as a general class. A modification of SOEP's quantitative sub-micro fluoride analytical method is presented as applicable to these isolation methods. Microgram quantities of organic fluorine compounds were found in the plant materials investigated but at a level too low for isolation and identification.

  13. Organic compounds leached from fast pyrolysis mallee leaf and bark biochars.

    Science.gov (United States)

    Lievens, Caroline; Mourant, Daniel; Gunawan, Richard; Hu, Xun; Wang, Yi

    2015-11-01

    Characterization of organic compounds leached from biochars is essential in assessing the possible toxicity of the biochar to the soils' biota. In this study the nature of the leached organic compounds from Mallee biochars, produced from pyrolysis of Mallee leaf and bark in a fluidised-bed pyrolyser at 400 and 580°C was investigated. Light bio-oil compounds and aromatic organic compounds were investigated. The 'bio-oil like' light compounds from leaf and bark biochars 'surfaces were obtained after leaching the chars with a solvent, suitable to dissolve the respective bio-oils. GC/MS was implemented to investigate the leachates. Phenolics, which are potentially harmful toxins, were detected and their concentration shown to be dependent on the char's origin and the char production temperature. Further, to simulate biochars amendment to soils, the chars were leached with water. The water-leached aromatic compounds from leaf and bark biochars were characterized using UV-fluorescence spectroscopy. Those results suggested that biochars contain leachable compounds of which the nature and amount is dependent on the biomass feedstock, pyrolysis temperature and leaching time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Azo compounds as a family of organic electrode materials for alkali-ion batteries.

    Science.gov (United States)

    Luo, Chao; Borodin, Oleg; Ji, Xiao; Hou, Singyuk; Gaskell, Karen J; Fan, Xiulin; Chen, Ji; Deng, Tao; Wang, Ruixing; Jiang, Jianjun; Wang, Chunsheng

    2018-02-27

    Organic compounds are desirable for sustainable Li-ion batteries (LIBs), but the poor cycle stability and low power density limit their large-scale application. Here we report a family of organic compounds containing azo group (N=N) for reversible lithiation/delithiation. Azobenzene-4,4'-dicarboxylic acid lithium salt (ADALS) with an azo group in the center of the conjugated structure is used as a model azo compound to investigate the electrochemical behaviors and reaction mechanism of azo compounds. In LIBs, ADALS can provide a capacity of 190 mAh g -1 at 0.5 C (corresponding to current density of 95 mA g -1 ) and still retain 90%, 71%, and 56% of the capacity when the current density is increased to 2 C, 10 C, and 20 C, respectively. Moreover, ADALS retains 89% of initial capacity after 5,000 cycles at 20 C with a slow capacity decay rate of 0.0023% per cycle, representing one of the best performances in all organic compounds. Superior electrochemical behavior of ADALS is also observed in Na-ion batteries, demonstrating that azo compounds are universal electrode materials for alkali-ion batteries. The highly reversible redox chemistry of azo compounds to alkali ions was confirmed by density-functional theory (DFT) calculations. It provides opportunities for developing sustainable batteries.

  15. Influence of organic nitro-compounds and of surface active compounds on the inverse voltametric determination of cadmium, lead and copper

    Energy Technology Data Exchange (ETDEWEB)

    Wahdat, F; Neeb, R

    1983-12-01

    The influence of surface active agents and of organic nitro-compounds alone and in combination on the potentiometric stripping analysis and anodic-stripping differential-pulse-polarography of Cd, Pb and Cu is investigated. In some cases PSA offers advantages for the determination of these elements in the presence of organic nitro-compounds in comparison with differential pulse-polarography.

  16. Precipitation of organic arsenic compounds and their degradation products during struvite formation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jin-Biao; Yuan, Shoujun [School of Civil Engineering, Hefei University of Technology, Hefei 230009 (China); Institute of Water Treatment and Wastes Reutilization, Hefei University of Technology, Hefei 230009 (China); Wang, Wei, E-mail: dwhit@126.com [School of Civil Engineering, Hefei University of Technology, Hefei 230009 (China); Institute of Water Treatment and Wastes Reutilization, Hefei University of Technology, Hefei 230009 (China); Hu, Zhen-Hu, E-mail: zhhu@hfut.edu.cn [School of Civil Engineering, Hefei University of Technology, Hefei 230009 (China); Institute of Water Treatment and Wastes Reutilization, Hefei University of Technology, Hefei 230009 (China); Yu, Han-Qing [Department of Chemistry, University of Science & Technology of China, Hefei 230026 (China)

    2016-11-05

    Highlights: • Organic and inorganic arsenic compounds precipitated during struvite formation. • Precipitation of organic arsenic compounds in struvite decreased with increasing pH. • Arsenate easily precipitate in struvite as compared to organic arsenic compounds. • Arsenic compounds in solution affected the shape of struvite crystallization products. - Abstract: 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 (NH{sub 4}{sup +}-N) and phosphate (PO{sub 4}{sup 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 PO{sub 4}{sup 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.

  17. Sorption interactions of organic compounds with soils affected by agricultural olive mill wastewater.

    Science.gov (United States)

    Keren, Yonatan; Borisover, Mikhail; Bukhanovsky, Nadezhda

    2015-11-01

    The organic compound-soil interactions may be strongly influenced by changes in soil organic matter (OM) which affects the environmental fate of multiple organic pollutants. The soil OM changes may be caused by land disposal of various OM-containing wastes. One unique type of OM-rich waste is olive mill-related wastewater (OMW) characterized by high levels of OM, the presence of fatty aliphatics and polyphenolic aromatics. The systematic data on effects of the land-applied OMW on organic compound-soil interactions is lacking. Therefore, aqueous sorption of simazine and diuron, two herbicides, was examined in batch experiments onto three soils, including untreated and OMW-affected samples. Typically, the organic compound-soil interactions increased following the prior land application of OMW. This increase is associated with the changes in sorption mechanisms and cannot be attributed solely to the increase in soil organic carbon content. A novel observation is that the OMW application changes the soil-sorbent matrix in such a way that the solute uptake may become cooperative or the existing ability of a soil sorbent to cooperatively sorb organic molecules from water may become characterized by a larger affinity. The remarkable finding of this study was that in some cases a cooperative uptake of organic molecules by soils makes itself evident in distinct sigmoidal sorption isotherms rarely observed in soil sorption of non-ionized organic compounds; the cooperative herbicide-soil interactions may be characterized by the Hill model coefficients. However, no single trend was found for the effect of applied OMW on the mechanisms of organic compound-soil interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Isomorphous Crystals from Diynes and Bromodiynes Involved in Hydrogen and Halogen Bonds

    Directory of Open Access Journals (Sweden)

    Pierre Baillargeon

    2016-04-01

    Full Text Available Isomorphous crystals of two diacetylene derivatives with carbamate functionality (BocNH-CH2-diyne-X, where X = H or Br have been obtained. The main feature of these structures is the original 2D arrangement (as supramolecular sheets or walls in which the H bond and halogen bond have a prominent effect on the whole architecture. The two diacetylene compounds harbor neighboring carbamate (Boc protected amine and conjugated alkyne functionalities. They differ only by the nature of the atom located at the penultimate position of the diyne moiety, either a hydrogen atom or a bromine atom. Both of them adopt very similar 2D wall organizations with antiparallel carbamates (as in antiparallel beta pleated sheets. Additional weak interactions inside the same walls between molecular bricks are H bond interactions (diyne-H···O=C or halogen bond interactions (diyne-Br···O=C, respectively. Based on crystallographic atom coordinates, DFT (B3LYP/6-31++G(d,p and DFT (M06-2X/6-31++G(d,p calculations were performed on these isostructural crystals to gain insight into the intermolecular interactions.

  19. Source apportionment of airborne particulate matter using organic compounds as tracers

    Science.gov (United States)

    Schauer, James J.; Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

    A chemical mass balance receptor model based on organic compounds has been developed that relates source contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected specifically for the purpose of testing this model. The contributions of up to nine primary particle source types can be separately identified in ambient samples based on this method, and approximately 85% of the organic fine aerosol is assigned to primary sources on an annual average basis. The model provides information on source contributions to fine mass concentrations, fine organic aerosol concentrations and individual organic compound concentrations. The largest primary source contributors to fine particle mass concentrations in Los Angeles are found to include diesel engine exhaust, paved road dust, gasoline-powered vehicle exhaust, plus emissions from food cooking and wood smoke, with smaller contribution from tire dust, plant fragments, natural gas combustion aerosol, and cigarette smoke. Once these primary aerosol source contributions are added to the secondary sulfates, nitrates and organics present, virtually all of the annual average fine particle mass at Los Angeles area monitoring sites can be assigned to its source.

  20. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    International Nuclear Information System (INIS)

    Daisey, J.M.

    1991-11-01

    There is considerable interest in the ''unattached'' fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the ''unattached'' fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the 218 PoO 2 + ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the 218 PoO 2 + ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the 218 PoO 2 + ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos)

  1. Sensory irritating potency of some microbial volatile organic compounds (MVOCs) and a mixture of five MVOCs.

    Science.gov (United States)

    Korpi, A; Kasanen, J P; Alarie, Y; Kosma, V M; Pasanen, A L

    1999-01-01

    The authors investigated the ability/potencies of 3 microbial volatile organic compounds and a mixture of 5 microbial volatile organic compounds to cause eye and upper respiratory tract irritation (i.e., sensory irritation), with an animal bioassay. The authors estimated potencies by determining the concentration capable of decreasing the respiratory frequency of mice by 50% (i.e., the RD50 value). The RD50 values for 1-octen-3-ol, 3-octanol, and 3-octanone were 182 mg/m3 (35 ppm), 1359 mg/m3 (256 ppm), and 17586 mg/m3 (3360 ppm), respectively. Recommended indoor air levels calculated from the individual RD50 values for 1-octen-3-ol, 3-octanol, and 3-octanone were 100, 1000, and 13000 microg/m3, respectively-values considerably higher than the reported measured indoor air levels for these compounds. The RD50 value for a mixture of 5 microbial volatile organic compounds was also determined and found to be 3.6 times lower than estimated from the fractional concentrations and the respective RD50s of the individual components. The data support the conclusion that a variety of microbial volatile organic compounds may have some synergistic effects for the sensory irritation response, which constrains the interpretation and application of recommended indoor air levels of individual microbial volatile organic compounds. The results also showed that if a particular component of a mixture was much more potent than the other components, it may dominate the sensory irritation effect. With respect to irritation symptoms reported in moldy houses, the results of this study indicate that the contribution of microbial volatile organic compounds to these symptoms seems less than previously supposed.

  2. Development of sampling method and chromatographic analysis of volatile organic compounds emitted from human skin.

    Science.gov (United States)

    Grabowska-Polanowska, Beata; Miarka, Przemysław; Skowron, Monika; Sułowicz, Joanna; Wojtyna, Katarzyna; Moskal, Karolina; Śliwka, Ireneusz

    2017-10-01

    The studies on volatile organic compounds emitted from skin are an interest for chemists, biologists and physicians due to their role in development of different scientific areas, including medical diagnostics, forensic medicine and the perfume design. This paper presents a proposal of two sampling methods applied to skin odor collection: the first one uses a bag of cellulose film, the second one, using cellulose sachets filled with active carbon. Volatile organic compounds were adsorbed on carbon sorbent, removed via thermal desorption and analyzed using gas chromatograph with mass spectrometer. The first sampling method allowed identification of more compounds (52) comparing to the second one (30). Quantitative analyses for acetone, butanal, pentanal and hexanal were done. The skin odor sampling method using a bag of cellulose film, allowed the identification of many more compounds when compared with the method using a sachet filled with active carbon.

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

    Science.gov (United States)

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

    2012-12-01

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

  4. Fast GC-analysis of selected organic compounds at trace levels with the novel RAPID-MS/MS-technology

    International Nuclear Information System (INIS)

    Poell, S.

    2002-03-01

    The main topic of the present thesis was the development of rapid analytical procedures for the environmental analysis of a steel producing company, to speed up the sample throughput for the daily routine work. Additionally, high precision of analysis results was requested. This brought a certain effort concerning the validation of the results which was supported by the analysis of certified reference materials. Special interest was laid on the optimization of the trace analysis of dioxins and furans (PCDD/DF). An expansion of the established methods with powerful techniques like single ion storage and tandem-mass spectrometry resulted in an obvious improvement of the limits of quantitation and the reliability of analysis. Further advances could be achieved with the simplification of the clean-up procedure by the application of a new sampling technique which reduced the demand on sample preparation time as well. Analysis were also carried out with brominated Dioxins and Furans (PBrDD/DF). The next item focused on the analysis of polycyclic aromatic hydrocarbons (PAH) with the implementation of five new representatives with a highly carcinogenic potential. In this case, the coupling of three detectors resulted in a robust and precise HPLC-method with a highly qualitative and quantitative analytical reliability. Furthermore, the aim was to promote the routine analysis of alkylated aromatics (BTEX) and halogenated volatile organic (VOC) compounds. By the use of gas chromatography coupled with mass spectrometric detection a common analytical technique for both classes of substances could be found with an enhancement of sensitivity due to application of the single ion storage technique. The existing method for the determination of polychlorinated biphenyls (PCB) was improved by replacing the electron capture detector with mass spectrometry. Due to an optimization of the single ion storage and tandem mass spectrometry parameters the requested demands on low detection

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Efficiency of inductively torch plasma operating at atmospheric pressure on destruction of chlorinated liquid wastes- A path to the treatment of radioactive organic halogen liquid wastes

    Science.gov (United States)

    Kamgang-Youbi, G.; Poizot, K.; Lemont, F.

    2012-12-01

    The performance of a plasma reactor for the degradation of chlorinated hydrocarbon waste is reported. Chloroform was used as a target for a recently patented destruction process based using an inductive plasma torch. Liquid waste was directly injected axially into the argon plasma with a supplied power of ~4 kW in the presence of oxygen as oxidant and carrier gas. Decomposition was performed at CHCl3 feed rates up to 400 g·h-1 with different oxygen/waste molar ratios, chloroform destruction was obtained with at least 99% efficiency and the energy efficiency reached 100 g·kWh-1. The conversion end products were identified and assayed by online FTIR spectroscopy (CO2, HCl and H2O) and redox titration (Cl2). Considering phosgene as representative of toxic compounds, only very small quantities of toxics were released (rates. The experimental results were very close to the equilibrium composition predicted by thermodynamic calculations. At the bottom of the reactor, the chlorinated acids were successfully trapped in a scrubber and transformed into mineral salts, hence, only CO2 and H2O have been found in the final off-gases composition.

  7. Efficiency of inductively torch plasma operating at atmospheric pressure on destruction of chlorinated liquid wastes- A path to the treatment of radioactive organic halogen liquid wastes

    International Nuclear Information System (INIS)

    Kamgang-Youbi, G; Poizot, K; Lemont, F

    2012-01-01

    The performance of a plasma reactor for the degradation of chlorinated hydrocarbon waste is reported. Chloroform was used as a target for a recently patented destruction process based using an inductive plasma torch. Liquid waste was directly injected axially into the argon plasma with a supplied power of ∼4 kW in the presence of oxygen as oxidant and carrier gas. Decomposition was performed at CHCl 3 feed rates up to 400 g·h −1 with different oxygen/waste molar ratios, chloroform destruction was obtained with at least 99% efficiency and the energy efficiency reached 100 g·kWh −1 . The conversion end products were identified and assayed by online FTIR spectroscopy (CO 2 , HCl and H 2 O) and redox titration (Cl 2 ). Considering phosgene as representative of toxic compounds, only very small quantities of toxics were released ( −1 ) even with high waste feed rates. The experimental results were very close to the equilibrium composition predicted by thermodynamic calculations. At the bottom of the reactor, the chlorinated acids were successfully trapped in a scrubber and transformed into mineral salts, hence, only CO 2 and H 2 O have been found in the final off-gases composition.

  8. Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations

    Science.gov (United States)

    Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

    1996-08-01

    An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that

  9. Identification of novel synthetic organic compounds with supersonic gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fialkov, Alexander B; Amirav, Aviv

    2004-11-26

    Several novel synthetic organic compounds were successfully analyzed with a unique type of GC-MS titled Supersonic GC-MS following a failure in their analysis with standard GC-MS. Supersonic GC-MS is based on interfacing GC and MS with a supersonic molecular beam (SMB) and on electron ionization of sample compounds as vibrationally cold molecules while in the SMB, or by cluster chemical ionization. The analyses of novel synthetic organic compounds significantly benefited from the extended range of compounds amenable to analyses with the Supersonic GC-MS. The Supersonic GC-MS enabled the analysis of thermally labile compounds that usually degrade in the GC injector, column and/or ion source. Due to the high carrier gas flow rate at the injector liner and column these compounds eluted without degradation at significantly lower elution temperatures and the use of fly-through EI ion source eliminated any sample degradation at the ion source. The cold EI feature of providing trustworthy enhanced molecular ion (M+), complemented by its optional further confirmation with cluster CI was highly valued by the synthetic organic chemists that were served by the Supersonic GC-MS. Furthermore, the provision of extended mass spectral structural, isomer and isotope information combined with short (a few minutes) GC-MS analysis times also proved beneficial for the analysis of unknown synthetic organic compounds. As a result, the synthetic organic chemists were provided with both qualitative and quantitative data on the composition of their synthetic mixture, and could better follow the path of their synthetic chemistry. Ten cases of such analyses are demonstrated in figures and discussed.

  10. Analysis of organic compounds by secondary neutral mass spectrometry (SNMS) and secondary ion mass spectrometry (SIMS)

    International Nuclear Information System (INIS)

    Ewinger, H.P.

    1993-05-01

    This study is about the use of secondary neutral mass spectrometry (SNMS) and secondary ion mass spectrometry (SIMS) as analytical techniques with depth resolution in determining organic components in environmental solid microparticles. The first application of plasma SNMS to organic compounds revealed the spectra to be composed mainly of signals from the atoms of all participating elements, such as C, H, O, N, S, P, and Cl. In addition, signals produced by multi-atomic clusters can be detected, such as CH, C 2 , CH 2 , C 2 H, and C 3 , as well as signals indicating the presence of organic compounds with hetero elements, such as OH, NH, and CN. Their intensity decreases very markedly with increasing numbers of atoms. Among the signals from bi-atomic clusters, those coming from elements with large mass differences are most intense. The use of plasma SNMS with organic compounds has shown that, except for spurious chemical reactions induced by ion bombardment and photodesorption by the photons of the plasma, it is possible to analyze with resolution in depth, elements of organic solids. A more detailed molecular characterization of organic compounds is possible by means of SIMS on the basis of multi-atomic fragments and by comparison with suitable signal patterns. (orig./BBR) [de

  11. Evaluation of soluble organic compounds generated by radiological degradation of asphalt

    International Nuclear Information System (INIS)

    Fukumoto, M.; Nishikawa, Y.; Kagawa, A.; Kawamura, K.

    2000-12-01

    The soluble organic compounds generated by radiological degradation of asphalt (γ ray) were confirmed as a part of influence of the bituminized waste degradation in the TRU waste repository. Especially, the influence of the nitrate was focused on. As a result, the concentration of the soluble organic compounds generated by radiological degradation of asphalt (10 MGy, γ ray which is correspond to absorbed dose of asphalt for 1,000,000 years) were lower (each formic acid: about 50 mg/dm 3 , acetic acid: about 30 mg/dm 3 and oxalic acid: about 2 mg/dm 3 ) than that of the formic acid, the acetic acid and the oxalic acid which Valcke et al. had shown (the influence of the organic at the solubility examination which uses Pu and Am). Moreover, the change in the concentration of TOC and the soluble organic compounds (formic acid, acetic acid and oxalic acid) is little under the existence of nitrate ion. That is, the formic acid and acetic acid which can be organic ligands were generated little by oxidative decomposition of asphalt in the process that nitrate ion becomes nitride ion by radiation. The influence of the soluble organic compounds by the radiological degradation of the asphalt (γ ray) on adsorption and solubility by the complexation of radionuclides in the performance assessment can be limited. (author)

  12. Hammerhead ribozyme activity and oligonucleotide duplex stability in mixed solutions of water and organic compounds

    Directory of Open Access Journals (Sweden)

    Shu-ichi Nakano

    2014-01-01

    Full Text Available Nucleic acids are useful for biomedical targeting and sensing applications in which the molecular environment is different from that of a dilute aqueous solution. In this study, the influence of various types of mixed solutions of water and water-soluble organic compounds on RNA was investigated by measuring the catalytic activity of the hammerhead ribozyme and the thermodynamic stability of an oligonucleotide duplex. The compounds with a net neutral charge, such as poly(ethylene glycol, small primary alcohols, amide compounds, and aprotic solvent molecules, added at high concentrations changed the ribozyme-catalyzed RNA cleavage rate, with the magnitude of the effect dependent on the NaCl concentration. These compounds also changed the thermodynamic stability of RNA base pairs of an oligonucleotide duplex and its dependence on the NaCl concentration. Specific interactions with RNA molecules and reduced water activity could account for the inhibiting effects on the ribozyme catalysis and destabilizing effects on the duplex stability. The salt concentration dependence data correlated with the dielectric constant, but not with water activity, viscosity, and the size of organic compounds. This observation suggests the significance of the dielectric constant effects on the RNA reactions under molecular crowding conditions created by organic compounds.

  13. Phosphorus sorption on marine carbonate sediment: phosphonate as model organic compounds.

    Science.gov (United States)

    Huang, Xiao-Lan; Zhang, Jia-Zhong

    2011-11-01

    Organophosphonate, characterized by the presence of a stable, covalent, carbon to phosphorus (C-P) bond, is a group of synthetic or biogenic organophosphorus compounds. The fate of these organic phosphorus compounds in the environment is not well studied. This study presents the first investigation on the sorption of phosphorus (P) in the presence of two model phosphonate compounds, 2-aminothylphosphonoic acid (2-AEP) and phosphonoformic acid (PFA), on marine carbonate sediments. In contrast to other organic P compounds, no significant inorganic phosphate exchange was observed in seawater. P was found to adsorb on the sediment only in the presence of PFA, not 2-AEP. This indicated that sorption of P from phosphonate on marine sediment was compound specific. Compared with inorganic phosphate sorption on the same sediments, P sorption from organic phosphorus is much less in the marine environment. Further study is needed to understand the potential role of the organophosphonate compounds in biogeochemical cycle of phosphorus in the environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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).

  15. Microbial transformations of natural organic compounds and radionuclides in subsurface environments

    International Nuclear Information System (INIS)

    Francis, A.J.

    1985-10-01

    A major national concern in the subsurface disposal of energy wastes is the contamination of ground and surface waters by waste leachates containing radionuclides, toxic metals, and organic compounds. Microorganisms play an important role in the transformation of organic compounds, radionuclides, and toxic metals present in the waste and affect their mobility in subsurface environments. Microbial processes involved in dissolution, mobilization, and immobilization of toxic metals under aerobic and anaerobic conditions are briefly reviewed. Metal complexing agents and several organic acids produced by microbial action affect mobilization of radionuclides and toxic metals in subsurface environments. Information on the persistence of and biodegradation rates of synthetic as well as microbiologically produced complexing agents is scarce but important in determining the mobility of metal organic complexes in subsoils. Several gaps in knowledge in the area of microbial transformation of naturally occurring organics, radionuclides, and toxic metals have been identified, and further basic research has been suggested. 31 refs., 1 fig., 3 tabs

  16. Effect of organic complexing compounds and surfactants on coprecipitation of cesium radionuclides with nickel ferrocyanide precipitate

    International Nuclear Information System (INIS)

    Milyutin, V.V.; Gelis, V.M.; Ershov, B.G.; Seliverstov, A.F.

    2008-01-01

    One studied the effect of the organic complexing compounds and of the surfactants on the coprecipitation of Cs trace amounts with the nickel ferrocyanide precipitate. The presence of the oxalate- and ethylenediamin-tetraacetate-ions in the solutions is shown to result in the abrupt reduction of Cs coprecipitation degree. The effect of the various surfactants manifested itself not so explicitly. To reduce the negative effect of the organic compounds on the intimacy of Cs coprecipitation one tried out the procedure of their chemical destruction by ozon. Pre-ozonization of the solutions enabled to prevent the negative effect of the organic complexing compounds and of the surfactants on Cs coprecipitation with nickel ferrocyanide precipitate [ru

  17. A methodology for ranking and hazard identification of xenobiotic organic compounds in urban stormwater

    DEFF Research Database (Denmark)

    Baun, Anders; Eriksson, Eva; Ledin, Anna

    2006-01-01

    The paper presents a novel methodology (RICH, Ranking and Identification of Chemical Hazards) for ranking and identification of xenobiotic organic compounds of environmental concern in stormwater discharged to surface water. The RICHmethod is illustrated as a funnel fitted with different filters...... in hazard/risk assessments, a justified list of stormwater priority pollutants which must be included in hazard/risk assessments, and a list of compounds which may be present in discharged stormwater, but cannot be evaluated due to lack of data. The procedure was applied to 233 xenobiotic organic chemicals...... with xenobiotic organic compounds (XOCs) found in urban stormwater, but it may be transferred to other environmental compartments and problems. Thus, the RICH procedure can be used as a stand-alone tool for selection of potential priority pollutants or it can be integrated in larger priority setting frameworks....

  18. Organic compounds in produced waters from coalbed natural gas wells in the Powder River Basin, Wyoming, USA

    Science.gov (United States)

    Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Rice, C.A.; Bartos, T.T.; Bates, A.L.; Tewalt, S.; Corum, M.D.

    2007-01-01

    The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 ??g/L. Concentrations of individual compounds ranged from about 18 to compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. In many areas, including the PRB, coal strata provide aquifers for drinking water wells. Organic compounds observed in produced water are also likely present in drinking water supplied from wells in the coal. Some of the organic compounds identified in the produced water samples are potentially toxic, but at the levels measured in these samples are unlikely to have acute health effects. The human health effects of low-level, chronic exposure to coal-derived organic compounds in drinking water are currently unknown. Continuing studies will evaluate possible toxic effects from low level, chronic exposure to coal-derived organic compounds in drinking water supplies.

  19. Role of effluent organic matter in the photochemical degradation of compounds of wastewater origin.

    Science.gov (United States)

    Bodhipaksha, Laleen C; Sharpless, Charles M; Chin, Yu-Ping; MacKay, Allison A

    2017-03-01

    The photoreactivity of treated wastewater effluent organic matter differs from that of natural organic matter, and the indirect phototransformation rates of micropollutants originating in wastewater are expected to depend on the fractional contribution of wastewater to total stream flow. Photodegradation rates of four common compounds of wastewater origin (sulfamethoxazole, sulfadimethoxine, cimetidine and caffeine) were measured in river water, treated municipal wastewater effluent and mixtures of both to simulate various effluent-stream water mixing conditions that could occur in environmental systems. Compounds were chosen for their unique photodegradation pathways with the photochemically produced reactive intermediates, triplet-state excited organic matter ( 3 OM*), singlet oxygen ( 1 O 2 ), and hydroxyl radicals (OH). For all compounds, higher rates of photodegradation were observed in effluent relative to upstream river water. Sulfamethoxazole degraded primarily via direct photolysis, with some contribution from OH and possibly from carbonate radicals and other unidentified reactive intermediates in effluent-containing samples. Sulfadimethoxine also degraded mainly by direct photolysis, and natural organic matter appeared to inhibit this process to a greater extent than predicted by light screening. In the presence of effluent organic matter, sulfadimethoxine showed additional reactions with OH and 1 O 2 . In all water samples, cimetidine degraded by reaction with 1 O 2 (>95%) and caffeine by reaction with OH (>95%). In river water mixtures, photodegradation rate constants for all compounds increased with increasing fractions of effluent. A conservative mixing model was able to predict reaction rate constants in the case of hydroxyl radical reactions, but it overestimated rate constants in the case of 3 OM* and 1 O 2 pathways. Finally, compound degradation rate constants normalized to the rate of light absorption by water correlated with E 2 /E 3 ratios

  20. Reversible Capture and Release of Cl2 and Br2 with a Redox-Active Metal-Organic Framework.

    Science.gov (United States)

    Tulchinsky, Yuri; Hendon, Christopher H; Lomachenko, Kirill A; Borfecchia, Elisa; Melot, Brent C; Hudson, Matthew R; Tarver, Jacob D; Korzyński, Maciej D; Stubbs, Amanda W; Kagan, Jacob J; Lamberti, Carlo; Brown, Craig M; Dincă, Mircea

    2017-04-26

    Extreme toxicity, corrosiveness, and volatility pose serious challenges for the safe storage and transportation of elemental chlorine and bromine, which play critical roles in the chemical industry. Solid materials capable of forming stable nonvolatile compounds upon reaction with elemental halogens may partially mitigate these challenges by allowing safe halogen release on demand. Here we demonstrate that elemental halogens quantitatively oxidize coordinatively unsaturated Co(II) ions in a robust azolate metal-organic framework (MOF) to produce stable and safe-to-handle Co(III) materials featuring terminal Co(III)-halogen bonds. Thermal treatment of the oxidized MOF causes homolytic cleavage of the Co(III)-halogen bonds, reduction to Co(II), and concomitant release of elemental halogens. The reversible chemical storage and thermal release of elemental halogens occur with no significant losses of structural integrity, as the parent cobaltous MOF retains its crystallinity and porosity even after three oxidation/reduction cycles. These results highlight a material operating via redox mechanism that may find utility in the storage and capture of other noxious and corrosive gases.

  1. Estrogenicity of halogenated bisphenol A: in vitro and in silico investigations.

    Science.gov (United States)

    Zhang, Jie; Li, Tiezhu; Wang, Tuoyi; Yuan, Cuiping; Zhong, Shuning; Guan, Tianzhu; Li, Zhuolin; Wang, Yongzhi; Yu, Hansong; Luo, Quan; Wang, Yongjun; Zhang, Tiehua

    2018-03-01

    The binding interactions of bisphenol A (BPA) and its halogenated derivatives (halogenated BPAs) to human estrogen receptor α ligand binding domain (hERα-LBD) was investigated using a combined in vitro and in silico approach. First, the recombinant hERα-LBD was prepared as a soluble protein in Escherichia coli BL21(DE3)pLysS. A native fluorescent phytoestrogen, coumestrol, was employed as tracer for the fluorescence polarization assay. The results of the in vitro binding assay showed that bisphenol compounds could bind to hERα-LBD as the affinity ligands. All the tested halogenated BPAs exhibited weaker receptor binding than BPA, which might be explained by the steric effect of substituents. Molecular docking studies elucidated that the halogenated BPAs adopted different conformations in the flexible hydrophobic ligand binding pocket (LBP), which is mainly dependent on their distinct halogenation patterns. The compounds with halogen substituents on the phenolic rings and on the bridging alkyl moiety acted as agonists and antagonists for hERα, respectively. Interestingly, all the compounds in the agonist conformation of hERα formed a hydrogen bond with His524, while the compounds in the antagonist conformation formed a hydrogen bond with Thr347. These docking results suggested a pivotal role of His524/Thr347 in maintaining the hERα structure in the biologically active agonist/antagonist conformation. Comparison of the calculated binding energies vs. experimental binding affinities yielded a good correlation, which might be applicable for the structure-based design of novel bisphenol compounds with reduced toxicities and for environmental risk assessment. In addition, based on hERα-LBD as a recognition element, the proposed fluorescence polarization assay may offer an alternative to chromatographic techniques for the multi-residue determination of bisphenol compounds.

  2. Application of organic compounds for high-order harmonic generation of ultrashort pulses

    Science.gov (United States)

    Ganeev, R. A.

    2016-02-01

    The studies of the high-order nonlinear optical properties of a few organic compounds (polyvinyl alcohol, polyethylene, sugar, coffee, and leaf) are reported. Harmonic generation in the laser-produced plasmas containing the molecules and large particles of above materials is demonstrated. These studies showed that the harmonic distributions and harmonic cutoffs from organic compound plasmas were similar to those from the graphite ablation. The characteristic feature of observed harmonic spectra was the presence of bluesided lobes near the lower-order harmonics.

  3. Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

    Science.gov (United States)

    Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

    2016-11-01

    The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

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

    International Nuclear Information System (INIS)

    Suominen, K.; Verta, M.; Marttinen, S.

    2014-01-01

    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. - Highlights:

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

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, K., E-mail: kimmo.suominen@evira.fi [Finnish Food Safety Authority Evira, Risk Assessment Research Unit, Mustialankatu 3, 00790 Helsinki (Finland); Verta, M. [Finnish Environmental Institute (SYKE), Mechelininkatu 34a, P.O. Box 140, 00251 Helsinki (Finland); Marttinen, S. [MTT Agrifood Research Finland, 31600 Jokioinen (Finland)

    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. - Highlights:

  6. METHOD FOR PRODUCING ISOTOPIC METHANES AND PARTIALLY HALOGENATED DERIVATIVES THEROF

    Science.gov (United States)

    Frazer, J.W.

    1959-08-18

    A method is given for producing isotopic methanes and/ or partially halogenated derivatives. Lithium hydride, deuteride, or tritide is reacted with a halogenated methane or with a halogenated methane in combination with free halogen. The process is conveniently carried out by passing a halogenated methane preferably at low pressures or in an admixture with an inert gas through a fixed bed of finely divided lithium hydride heated initially to temperatures of 100 to 200 deg C depending upon the halogenated methane used.

  7. Comparative study in vitro of contraction percentage by polymerization of the compound resins: FiltekTMZ350 XT, BRILLIANTTMNG, Vit-l-escence®, when subjected to halogen light, applying the Archimedes' principle

    International Nuclear Information System (INIS)

    Castro Brenes, Maria Jose; Duran Leon, Luis Edgardo

    2013-01-01

    The contraction by polymerization in vitro is determined in three resins (Filtek TM Z350 XT, BRILLIANT TM NG, Vit-l-escence®), when exposed to halogen light during 60 seconds and applying the Archimedes' principle. This method has provided to professional the criteria to consider for the selection of the material according to the therapeutic requirements. Archimedes' principle is applied like a tool to determine the contraction by polymerization of the resins; however, human errors may be present due to manipulation, omission or losses of the product during processing. The contraction by polymerization of the resins is estimated, where Filtek TM Z350 XT has been the that least volumetric contraction has experienced, followed by BRILLIANT TM NG and lastly Vit-l-escence®, has been the most is contracted of the three. Differences found between the resins studied are established according to contraction by polymerization and compared with the 'literature' and properties that are offered by fabricators. The characteristics of the resins Filtek TM Z350 XT, BRILLIANT TM NG, Vit-l-escence® are evaluated with respect to properties that have had higher or lower contraction by polymerization, to establish patterns of behavior according to their characteristics [es

  8. Insights into the attenuated sorption of organic compounds on black carbon aged in soil.

    Science.gov (United States)

    Luo, Lei; Lv, Jitao; Chen, Zien; Huang, Rixiang; Zhang, Shuzhen

    2017-12-01

    Sorption of organic compounds on fresh black carbons (BCs) can be greatly attenuated in soil over time. We examined herein the changes in surface properties of maize straw-derived BCs (biochars) after aged in a black soil and their effects on the sorptive behaviors of naphthalene, phenanthrene and 1,3-dinitrobenzene. Dissolved fulvic and humic acids extracted from the soil were used to explore the role of dissolved organic carbon (DOC) in the aging of biochars. Chromatography analysis indicated that DOC molecules with relatively large molecular weight were preferentially adsorbed on the biochars during the aging processes. DOC sorption led to blockage of the biochar's micropores according to N 2 and CO 2 adsorption analyses. Surface chemistry of the biochars was also substantially modified, with more O-rich functional groups on the aged biochars compared to the original biochars, as evidenced by Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. The changes in both the physical and chemical surface properties of biochars by DOC led to significant attenuation of the sorption capacity and nonlinearity of the nonionic organic compounds on the aged biochars. Among the tested organic compounds, phenanthrene was the most attenuated in its sorption by the aging treatments, possibly because of its relatively large molecular size and hydrophobicity. The information can help gain a mechanistic understanding of interactions between BCs and organic compounds in soil environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Prediction of RO/NF membrane rejections of PhACs and organic compounds : A statistical analysis

    NARCIS (Netherlands)

    Yangali-Quintanilla, V.; Kim, T.U.; Kennedy, M.; Amy, G.

    2008-01-01

    OA fund TU Delft Rejections of pharmaceutical compounds (Ibuprofen, Diclofenac, Clofibric acid, Naproxen, Primidone, Phenacetin) and organic compounds (Dichloroacetic acid, Trichloroacetic acid, Chloroform, Bromoform, Trichloroethene, Perchloroethene, Car-bontetrachloride, Carbontetrabromide) by NF

  10. Stripping of organic compounds from wastewater as an auxiliary fuel of regenerative thermal oxidizer

    International Nuclear Information System (INIS)

    Chang, Meng-Wen; Chern, Jia-Ming

    2009-01-01

    Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. In the cleaning processes of electronics industries, most volatile organic compounds (VOCs) are vented to air pollution control devices while most non-volatile organic solvents dissolve in the cleaning water and become the major sources of COD in wastewater. Discharging a high-COD wastewater stream to wastewater treatment facility often disturbs the treatment performance. A pretreatment of the high-COD wastewater is therefore highly desirable. This study used a packed-bed stripping tower in combination with a regenerative thermal oxidizer to remove the COD in the wastewater from a printed circuit board manufacturing process and to utilize the stripped organic compounds as the auxiliary fuel of the RTO. The experimental results showed that up to 45% of the COD could be removed and 66% of the RTO fuel could be saved by the combined treatment system.

  11. Synthetic organic compounds and their transformation products in groundwater: occurrence, fate and mitigation.

    Science.gov (United States)

    Postigo, Cristina; Barceló, Damià

    2015-01-15

    Groundwater constitutes the main source of public drinking water supply in many regions. Thus, the contamination of groundwater resources by organic chemicals is a matter of growing concern because of its potential effects on public health. The present manuscript compiles the most recent works related to the study of synthetic organic compounds (SOCs) in groundwater, with special focus on the occurrence of contaminants not or barely covered by previously published reviews, e.g., pesticide and pharmaceutical transformation products, lifestyle products, and industrial chemicals such as corrosion inhibitors, brominated and organophosphate flame retardants, plasticizers, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Moreover, the main challenges in managed aquifer recharge, i.e., reclaimed water injection and infiltration, and riverbank filtration, regarding natural attenuation of organic micropollutants are discussed, and insights into the future chemical quality of groundwater are provided. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Exploring sources of biogenic secondary organic aerosol compounds using chemical analysis and the FLEXPART model

    Directory of Open Access Journals (Sweden)

    J. Martinsson

    2017-09-01

    Full Text Available Molecular tracers in secondary organic aerosols (SOAs can provide information on origin of SOA, as well as regional scale processes involved in their formation. In this study 9 carboxylic acids, 11 organosulfates (OSs and 2 nitrooxy organosulfates (NOSs were determined in daily aerosol particle filter samples from Vavihill measurement station in southern Sweden during June and July 2012. Several of the observed compounds are photo-oxidation products from biogenic volatile organic compounds (BVOCs. Highest average mass concentrations were observed for carboxylic acids derived from fatty acids and monoterpenes (12. 3 ± 15. 6 and 13. 8 ± 11. 6 ng m−3, respectively. The FLEXPART model was used to link nine specific surface types to single measured compounds. It was found that the surface category sea and ocean was dominating the air mass exposure (56 % but contributed to low mass concentration of observed chemical compounds. A principal component (PC analysis identified four components, where the one with highest explanatory power (49 % displayed clear impact of coniferous forest on measured mass concentration of a majority of the compounds. The three remaining PCs were more difficult to interpret, although azelaic, suberic, and pimelic acid were closely related to each other but not to any clear surface category. Hence, future studies should aim to deduce the biogenic sources and surface category of these compounds. This study bridges micro-level chemical speciation to air mass surface exposure at the macro level.

  13. Effect of halogen substitution on the enthalpies of solvation and hydrogen bonding of organic solutes in chlorobenzene and 1,2-dichlorobenzene derived using multi-parameter correlations

    Energy Technology Data Exchange (ETDEWEB)

    Varfolomeev, Mikhail A.; Rakipov, Ilnaz T.; Khachatrian, Artashes A. [Department of Physical Chemistry, Kazan Federal University, Kremlevskaya 18, Kazan 420008 (Russian Federation); Acree, William E., E-mail: acree@unt.edu [Department of Chemistry, 1155 Union Circle # 305070, University of North Texas, Denton, TX 76203-5017 (United States); Brumfield, Michela [Department of Chemistry, 1155 Union Circle # 305070, University of North Texas, Denton, TX 76203-5017 (United States); Abraham, Michael H. [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2015-10-10

    Graphical abstract: - Highlights: • Enthalpies of solution measured for 43 solutes dissolved in chlorobenzene. • Enthalpies of solution measured for 72 solutes dissolved in 1,2-dichlorobenzene. • Mathematical expressions derived for predicting enthalpies of solvation of solutes in chlorobenzene. • Mathematical expressions derived for predicting enthalpies of solvation of solutes in 1,2-chlorobenzene. - Abstract: Enthalpies of solution at infinite dilution at 298 K, Δ{sub soln}H{sup A/Solvent}, have been measured by isothermal solution calorimetry for 43 and 72 organic solutes dissolved in chlorobenzene and 1,2-dichlorobenzene, respectively. The measured Δ{sub soln}H{sup A/Solvent} data, along with published Δ{sub soln}H{sup A/Solvent} values taken from the published literature for solutes dissolved in both chlorobenzene solvents, were converted to enthalpies of solvation, Δ{sub solv}H{sup A/Solvent}, using standard thermodynamic equations. Abraham model correlations were developed from the experimental Δ{sub solv}H{sup A/Solvent} data. The best derived correlations describe the experimental gas-to-chlorobenzene and gas-to-1,2-dichlorobenzene enthalpies of solvation to within standard deviations of 1.5 kJ mol{sup −1} and 1.9 kJ mol{sup −1}, respectively. Enthalpies of X−H…π (X – O, N, and C) hydrogen bond formation of proton donor solutes (alcohols, amines, chlorinated hydrocarbons, etc.) with chlorobenzene and 1,2-dichlorobenzene were calculated based on the Abraham solvation equation. Obtained values are in good agreement with the results determined using conventional methods.

  14. Environmental recovery by destruction of toxic organic compounds using electron beam accelerator

    International Nuclear Information System (INIS)

    Duarte, C.L; Sampa, M.H.O.; Rela, P.R.; Oikawa, H.

    2001-01-01

    The oxidation process has attracted many researchers because of the capacity to mineralise organic compounds. The most efficient oxidation is the use of OH radicals. There are various methods to generate OH radicals as the use of ozone, hydrogen peroxide and ultra-violet (AOP - Advanced Oxidation Process). The most simple and efficient method for generating OH radicals in situ is the interaction of ionizing radiation with water. The reactive species formed by the water irradiation are the reducing radical's solvated electron and H atoms and the oxidising radical hydroxyl OH. The reactive species will react with organic compounds in the water inducing their decomposition. The use of ionizing radiation has great ecological and technologies advantages, especially when compared to physical-chemical and biological methods. It degrades organic compounds, generating substances that are easily biodegraded without the necessity of adding chemical compounds. The purpose of the radiation treatment is the conversion of these substances to biodegradable compounds; sometimes the complete decomposition is not necessary for this conversion

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

    Directory of Open Access Journals (Sweden)

    Sílvio Terra Stefanello

    2015-01-01

    Full Text Available 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-tolylselanylpropan-2-amine (C1 and 1-(2-methoxyphenylselanyl-3-phenylpropan-2-amine (C2 and analogs of DPDS 1,2-bis(2-methoxyphenyldiselenide (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 C. 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 C. 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.

  16. The solubilities of significant organic compounds in HLW tank supernate solutions -- FY 1995 progress report

    International Nuclear Information System (INIS)

    Barney, G.S.

    1996-01-01

    At the Hanford Site organic compounds were measured in tank supernate simulant solutions during FY 1995. This solubility information will be used to determine if these organic salts could exist in solid phases (saltcake or sludges) in the waste where they might react violently with the nitrate or nitrite salts present in the tanks. Solubilities of sodium glycolate, succinate, and caproate salts; iron and aluminum and butylphosphate salts; and aluminum oxalate were measured in simulated waste supernate solutions at 25 degree C, 30 degree C, 40 degree C, and 50 degree C. The organic compounds were selected because they are expected to exist in relatively high concentrations in the tanks. The solubilities of sodium glycolate, succinate, caproate, and butylphosphate in HLW tank supernate solutions were high over the temperature and sodium hydroxide concentration ranges expected in the tanks. High solubilities will prevent solid sodium salts of these organic acids from precipitating from tank supernate solutions. The total organic carbon concentrations (YOC) of actual tank supernates are generally much lower than the TOC ranges for simulated supernate solutions saturated (at the solubility limit) with the organic salts. This is so even if all the dissolved carbon in a given tank and supernate is due to only one of these eight soluble compounds (an unlikely situation). Metal ion complexes of and butylphosphate and oxalate in supernate solutions were not stable in the presence of the hydroxide concentrations expected in most tanks. Iron and aluminum dibutylphosphate compounds reacted with hydroxide to form soluble sodium dibutylphosphate and precipitated iron and aluminum hydroxides. Aluminum oxalate complexes were also not stable in the basic simulated supernate solutions. Solubilities of all the organic salts decrease with increasing sodium hydroxide concentration because of the common ion effect of Na+. Increasing temperatures raised the solubilities of the organic

  17. Stimulated exoelectron emission dosimetry of organic compounds and of ionic crystals

    International Nuclear Information System (INIS)

    Rocca-Serra nee Chevtchenko, Nathalie

    1980-01-01

    The purpose of this work is the dosimetric study of stimulated exoelectron emission from various organic compounds (organic acid salts, amino acids) and ionic crystals (sodium chloride, magnesium oxide, calcium sulfate, lithium fluoride and α/β alumina). Experimental results obtained for α/β alumina leads us to determine physical properties of this material such as activation energies and frequency factors of traps involved in the exo-emission process. (author) [fr

  18. General scheme for elucidating the structure of organic compounds using spectroscopic and spectrometric methods

    International Nuclear Information System (INIS)

    Ribeiro, Carlos Magno R.; Souza, Nelson Angelo de

    2007-01-01

    This work describes a systematic method to be applied in undergraduate courses of organic chemistry, correlating infrared spectra, hydrogen and carbon-13 nuclear magnetic resonance, and mass spectra. To this end, a scheme and a table were developed to conduct the elucidation of the structure of organic compounds initially using infrared spectra. Interpretation of hydrogen and carbon-13 nuclear magnetic resonance spectra and of mass spectra is used to confirm the proposed structure. (author)

  19. Modeling of iodine radiation chemistry in the presence of organic compounds

    International Nuclear Information System (INIS)

    Taghipour, Fariborz; Evans, Greg J.

    2002-01-01

    A kinetic-based model was developed that simulates the radiation chemistry of iodine in the presence of organic compounds. The model's mechanistic description of iodine chemistry and generic semi-mechanistic reactions for various classes of organics, provided a reasonable representation of experimental results. The majority of the model and experimental results of iodine volatilization rates were in agreement within an order of magnitude

  20. Natural elimination of volatile halogenated hydrocarbons from the environment

    Energy Technology Data Exchange (ETDEWEB)

    Harress, H.M.; Grathwohl, P.; Torunski, H.

    1987-01-01

    Recently carried out field investigations of groundwater contaminations with volatile halogenated hydrocarbons have shown evidence of natural elimination of these hazardous substances. This elimination effects is rare and observed in connection with special geological conditions. With regard to some contaminated sites, the following mechanisms for this behaviour are discussed: 1. Stripping by naturally ascending gases. 2. Sorption on soil organic matter. 3. Biodegradation. The so far compiled knowledge allowed to develop further research programmes, which are pursued in various projects.

  1. Characterization of organic aromatic compounds in soils affected by an uncontrolled tire landfill fire through the use of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

    Science.gov (United States)

    Escobar-Arnanz, J; Mekni, S; Blanco, G; Eljarrat, E; Barceló, D; Ramos, L

    2018-02-09

    Discarded vehicle tires have become an increasing concern worldwide due to the enormous amount of wastes generated and the increasing evidence of health problems associated to their disposal and accidental combustion. Previous studies conducted involving either simulated or open uncontrolled tire fires have identified aromatics belonging to two main classes, volatile organic compounds and polycyclic aromatic compounds (PAHs), as the most relevant chemicals generated in these burning processes. As a consequence, and due to their recognized toxicity, most studies reported up to now have mainly focused on these two categories of compounds being information concerning the possible occurrence of other aromatic classes rather limited. In this study, the enhanced separation power and structural confirmation capabilities provided by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-ToF MS) has been used, for the first time, for the non-targeted analysis of soils impacted by a tire fire and an ash collected at the scene of the fire. In total, 118 volatile and semi-volatile aromatic compounds have been differentiated. Among them, 104 compounds have been either positively or tentatively identified. PAHs with 3-5 rings and their alkyl-derivatives were the most numerous and relevant classes in the investigated samples. A significant number of sulfur, oxygen- and nitrogen-containing PAHs were also detected in the samples. The application of a script function to the raw GC×GC-ToF MS data allowed the fast filtering and automatic recognition of compounds containing halogens in their structure. This part of the study evidenced that only a limited number of regulated persistent organic pollutants were present in the investigated samples. However, it also revealed the presence of emerging organophosphorous flame retardants, whose levels in tire fire impacted soils are reported for the first time. Copyright © 2017 Elsevier B.V. All rights

  2. Halogenated hydrocarbons - an environmental problem

    Energy Technology Data Exchange (ETDEWEB)

    Schoeler, H F; Thofern, E

    1984-01-01

    The paper provides a survey of the incidence of highly volatile halogenated hydrocarbons in ground, surface and drinking water as well as in the snows of Western Germany. Almost the entire production of chlorinated solvents is released into the environment. The absorption media are mostly soil, water and atmosphere. Whereas in the atmosphere elimination reactions take place, solvents that have passed the soil get into the ground water owing to their persistence and can cause considerable pollutions of drinking water. Moreover haloforms may occur in drinking water, which are produced during chlorine disinfection of pre-treated water.

  3. Deuterium enrichment by selective photo-induced dissociation of an organic carbonyl compound

    International Nuclear Information System (INIS)

    Marling, J.B.

    1981-01-01

    A deuterium-enriched material is produced by selective photoinduced dissociation of a gas phase organic carbonyl compound containing at least one hydrogen atom bonded to an atom adjacent to a carbonyl group. Alkyl carbonyl compounds such as acetone, acetaldehyde, trifluoroacetic acid, cyclobutanone, cyclopentanone, methyl acetate, 3,3-dimethyl-2-butanone, 2,4-pentanedione, and 4-methyl-2-pentanone are preferred. The carbonyl compound is subjected to intense infrared radiation from one laser, or two lasers operating at different frequencies, to selectively dissociate the deuterated molecules into stable products. The undissociated compound may be redeuterated by direct aqueous liquid phase H/D exchange, or by indirect liquid phase exchange using an alkanol in an intermediate step

  4. The Enantiomeric Ratios of Meteoritic Organic Compounds: Their Possible Roles in the Origin of Life

    Science.gov (United States)

    Cooper, George

    2012-01-01

    This talk will give an overview of the enantiomer (mirror-image) ratios of organic compounds in meteorites and also describe the results of the present work in my lab. The primary focus will be on sugar derivatives (sugar acids) of carbonaceous meteorites. Our work begins to address questions associated with chirality, i.e., the origins of homochirality. On Earth, biological monomers (amino acids, sugars, etc.) are usually found with one of the enantiomers more abundant than the other. However, biological polymers (proteins, nucleic acids, etc.) are only composed of one enantiomer i.e., they are homochiral. There are hints in meteorites that some organic molecules may also exist in homochiral forms. The talk will address questions such as: did extraterrestrial sources aid in the beginning of this homochirality? Do the increasing size and apparent enantiomer excesses of some meteoritic compounds also extend to larger meteoritic compounds and polymers?

  5. Chemisorption of organic iodine compounds forming from fission isotopes of radioactive iodine

    International Nuclear Information System (INIS)

    Tot, G.; Galina, F.; Zel'd, E.

    1977-01-01

    Studied is ethyl iodine adsorption, labelled by iodine 131, on palladium black and on aluminium oxide activized by palladium. The desorption of adsorbed iodine in the temperature range of 20-600 deg C by the mass spectroscopy and thermal gravimetric methods was investigated. At the ethyl iodine and palladium interaction the bond between carbon and iodine in the ethyl iodine molecule breaks down and extracting iodine reacts with palladium, forming a stable compound at high temperatures. Desorption of adsorbed iodine is insignificant up to the temperatures of 250-300 deg C. Thus, sorbents, containing palladium, may be successfully applied for iodine absorption from the organic iodine compounds. These compounds spontaneously appear from the iodine fragment ratio isotopes during their interaction with some environmental organic impurities

  6. Organically grown tomato (Lycopersicon esculentum Mill.): bioactive compounds in the fruit and infection with Phytophthora infestans.

    Science.gov (United States)

    Mohammed, Afrah E; Smit, Inga; Pawelzik, Elke; Keutgen, Anna J; Horneburg, Bernd

    2012-05-01

    Tomato fruits are characterized by a good nutritional profile, including different bioactive compounds such as carotenoids, phenolic compounds and ascorbic acid. The objective of this study was to analyze the content of bioactive compounds in the fruit and the infection by Phytophthora infestans of 28 tomato genotypes from organic outdoor production. The relationship between bioactive compounds in the fruit and infection with P. infestans was estimated. Field experiments were carried out in 2004 and 2005 at two locations in central Germany. Significant variation among genotypes, locations and years was observed for the content of lycopene, ascorbic acid, total phenolic compounds, antioxidant capacity and the infection level of P. infestans. Antioxidant capacity seemed to be influenced mainly by the phenolics and was highest in small fruits, which were less infected with P. infestans. The large genetic variation among tomato genotypes for the content of bioactive compounds in their fruit allows for selection gains. None of the investigated bioactive compounds can be recommended for the indirect selection for increased field resistance against P. infestans. Copyright © 2011 Society of Chemical Industry.

  7. The effect of the controlled oxygen on the incineration of radio contaminated organic compounds

    International Nuclear Information System (INIS)

    Yahata, Taneaki; Abe, Jiro; Hoshino, Akira.

    1982-02-01

    It is very important to resolve the method of safety storage and the reduction of volume of radio contaminated waste for utilization of atomic energies. Presently, the amounts of radio contaminated organic compounds such as ion exchange resin, vinyl chloride resin and so on are increased year by year. These compounds are very difficult to burning because of the occurrence of soot or flying ash, so that the waste are solidified using with cement or asphalt. But the burning of these compounds are most efficient method for reduction of volume of the wastes. The present work is an attempt to evaluate the effect of controlled oxygen on the incineration of these compounds, using by differential thermoelectrobalance. The given off gas from these compounds are mixture of hydrocarbon and free carbon examined by mass spectrography. As the result of this study, these compounds are decomposed perfectly under 5 - 10% of oxygen gas flow at about 650 0 C and the off gas from the compounds is disappeared contact with heated copper oxide without soot or flying ash. (author)

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

    Science.gov (United States)

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

    1999-01-01

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

  9. Synthesis, characterization and crystal structures of new organic compounds containing cyanoacrylic acid

    Czech Academy of Sciences Publication Activity Database

    Khalaji, A.D.; Mogheiseh, M.; Eigner, Václav; Dušek, Michal; Chow, T.J.; Maddahi, E.

    2015-01-01

    Roč. 1098, Oct (2015), s. 318-323 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : organic compounds * cyanoacrylic acid * single-crystal structure analysis * dye-sensitized solar cells * density functional theory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.780, year: 2015

  10. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    Science.gov (United States)

    2010-07-01

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

  11. The scent of colorectal cancer: detection by volatile organic compound analysis

    NARCIS (Netherlands)

    de Boer, Nanne K. H.; de Meij, Tim G. J.; Oort, Frank A.; Ben Larbi, Ilhame; Mulder, Chris J. J.; van Bodegraven, Adriaan A.; van der Schee, Marc P.

    2014-01-01

    The overall metabolic state of an individual is reflected by emitted volatile organic compounds (VOCs), which are gaseous carbon-based chemicals. In this review, we will describe the potential of VOCs as fully noninvasive markers for the detection of neoplastic lesions of the colon. VOCs are

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  13. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On and after the date on which the initial performance test, required by § 60.8, is completed, but no...

  14. New global fire emission estimates and evaluation of volatile organic compounds

    Science.gov (United States)

    C. Wiedinmyer; L. K. Emmons; S. K. Akagi; R. J. Yokelson; J. J. Orlando; J. A. Al-Saadi; A. J. Soja

    2010-01-01

    A daily, high-resolution, global fire emissions model has been built to estimate emissions from open burning for air quality modeling applications: The Fire INventory from NCAR (FINN version 1). The model framework uses daily fire detections from the MODIS instruments and updated emission factors, specifically for speciated non-methane organic compounds (NMOC). Global...

  15. Estimating the melting point, entropy of fusion, and enthalpy of fusion of organic compounds via SPARC

    Science.gov (United States)

    The entropies of fusion, enthalies of fusion, and melting points of organic compounds can be estimated through three models developed using the SPARC (SPARC Performs Automated Reasoning in Chemistry) platform. The entropy of fusion is modeled through a combination of interaction ...

  16. Dependence of negative muon depolarization on molecular weight and temperature in organic compounds

    International Nuclear Information System (INIS)

    Djuraev, A.A.; Evseev, V.S.; Obukhov, Yu.V.; Roganov, V.S.

    2009-01-01

    An atomic capture of negative muons in the aliphatic spirit series, the dependence of muon rest polarization on the molecular weight of spirit have been studied. The temperature dependence of depolarization in benzole and styrene has been obtained. The results on depolarization are being interpreted basing on notions about chemical interactions of mesic atoms in organic compounds. (author)

  17. Intermolecula transfer and elimination of molecular hydrogen in thermal reactions of unsaturated organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Suria, Sabartanty [Iowa State Univ., Ames, IA (United States)

    1995-02-10

    Two reactions which are important to coal liquefaction include intermolecular transfer and the elimination of two hydrogen atoms. We have designed several model reactions to probe the viability of several hydrogen transfer and elimination pathways. This report described studies on these reactions using organic model compounds.

  18. Profiling of volatile organic compounds produced by clinical Aspergillus isolates using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Gerritsen, M G; Brinkman, P; Escobar Salazar, Natalia; Bos, L D; de Heer, K; Meijer, M; Janssen, H-G; de Cock, H; Wösten, H A B; Visser, C.E.; van Oers, M H J; Sterk, P J

    Volatile organic compounds (VOCs) in exhaled breath may identify the presence of invasive pulmonary aspergillosis. We aimed to detect VOC profiles emitted by in vitro cultured, clinical Aspergillus isolates using gas chromatography-mass spectrometry (GC-MS). Three clinical Aspergillus isolates and a

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  20. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    Science.gov (United States)

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...