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Sample records for aromatic hydrocarbon neutrals

  1. Theoretical modeling of infrared emission from neutral and charged polycyclic aromatic hydrocarbons. II.

    NARCIS (Netherlands)

    Bakes, ELO; Tielens, AGGM; Bauschlicher, CW; Hudgins, DM; Allamandola, LJ

    2001-01-01

    The nature of the carriers of the interstellar infrared (IR) emission features between 3.3 and 12.7 mum is complex. We must consider emission from a family of polycyclic aromatic hydrocarbons (PAHs) in a multiplicity of cationic charge states (+1, +2, +3, and so on), along with neutral and anionic

  2. Laser Induced Fluorescence Spectroscopy of Neutral and Ionized Polycyclic Aromatic Hydrocarbons in the Cosmic Simulation Chamber

    Science.gov (United States)

    Bejaoui, Salma; Salama, Farid; Contreras, Cesar; Sciamma O'Brien, Ella; Foing, Bernard; Pascale, Ehrenfreund

    2015-01-01

    Polycyclic aromatic hydrocarbon (PAH) molecules are considered the best carriers to account for the ubiquitous infrared emission bands. PAHs have also been proposed as candidates to explain the diffuse interstellar bands (DIBs), a series of absorption features seen on the interstellar extinction curve and are plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments. Extensive efforts have been devoted over the past two decades to characterize the physical and chemical properties of PAH molecules and ions in space. Absorption spectra of PAH molecules and ions trapped in solid matrices have been compared to the DIBs. Absorption spectra of several cold, isolated gas-phase PAHs have also been measured under experimental conditions that mimic the interstellar conditions. The purpose of this study is to provide a new dimension to the existing spectroscopic database of neutral and single ionized PAHs that is largely based on absorption spectra by adding emission spectroscopy data. The measurements are based on the laser induced fluorescence (LIF) technique and are performed with the Pulsed Discharge Nozzle (PDN) of the COSmIC laboratory facility at NASA Ames laboratory. The PDN generates a plasma in a free supersonic jet expansion to simulate the physical and the chemical conditions in interstellar environments. We focus, here, on the fluorescence spectra of large neutral PAHs and their cations where there is a lack of fluorescence spectroscopy data. The astronomical implications of the data (e.g., ERE) are examined.

  3. Effects of Neutralization, Decoloration, and Deodorization on Polycyclic Aromatic Hydrocarbons during Laboratory-Scale Oil Refining Process

    Directory of Open Access Journals (Sweden)

    Yuxiang Ma

    2017-01-01

    Full Text Available The influence of technological operations during oil refining process on polycyclic aromatic hydrocarbons (PAHs in neutralized, bleached, and deodorized oils was investigated on the basis of laboratory-scale study. Under the best experimental conditions, benzo[a]pyrene decreased by 85.1%, 99.7%, and 40.8% in neutralized, bleached, and deodorized oils, respectively. Total of 16 analytes decreased by 55.7%, 87.5%, and 47.7%, respectively. Bleaching with activated charcoal was the most efficient procedure to reduce PAHs in crude oil. Neutralization had a modest influence on sixteen analytes; however, deodorization was only responsible for a slight decrease in the light PAHs and heavy PAHs contents. Data obtained in this study suggest that the use of activated carbon during oil refining process is highly recommended; moreover, these results provide a useful guidance for oil refining plant to reduce security risk and ensure the quality of the vegetable oil products.

  4. CHARACTERIZING THE INFRARED SPECTRA OF SMALL, NEUTRAL, FULLY DEHYDROGENATED POLYCYCLIC AROMATIC HYDROCARBONS

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, C. J.; Peeters, E.; Cami, J. [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Bauschlicher, C. W. Jr., E-mail: mackie@strw.leidenuniv.nl [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States)

    2015-02-01

    We present the results of a computational study to investigate the infrared spectroscopic properties of a large number of polycyclic aromatic hydrocarbon (PAH) molecules and their fully dehydrogenated counterparts. We constructed a database of fully optimized geometries for PAHs that is complete for eight or fewer fused benzene rings, thus containing 1550 PAHs and 805 fully dehydrogenated aromatics. A large fraction of the species in our database have clearly non-planar or curved geometries. For each species, we determined the frequencies and intensities of their normal modes using density functional theory calculations. Whereas most PAH spectra are fairly similar, the spectra of fully dehydrogenated aromatics are much more diverse. Nevertheless, these fully dehydrogenated species show characteristic emission features at 5.2 μm, 5.5 μm, and 10.6 μm; at longer wavelengths, there is a forest of emission features in the 16-30 μm range that appears as a structured continuum, but with a clear peak centered around 19 μm. We searched for these features in Spitzer-IRS spectra of various positions in the reflection nebula NGC 7023. We find a weak emission feature at 10.68 μm in all positions except that closest to the central star. We also find evidence for a weak 19 μm feature at all positions that is not likely due to C{sub 60}. We interpret these features as tentative evidence for the presence of a small population of fully dehydrogenated PAHs, and discuss our results in the framework of PAH photolysis and the formation of fullerenes.

  5. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  6. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  7. 4N electron aromatic cycles in polycyclic hydrocarbons.

    Science.gov (United States)

    Mauksch, Michael; Tsogoeva, Svetlana B

    2017-05-31

    Polycyclic fully conjugated hydrocarbons in which aromatics are fused to aromatics - or aromatics to antiaromatics - are important as potential organic semiconductors. Herein we explore the only remaining fusion pattern of antiaromatics to antiaromatics. It is shown computationally that the central antiaromatic unit (cyclobutadiene or pentalene) in such a three-unit polycyclic hydrocarbon, generated by fusion of three antiaromatic molecules, turns aromatic according to magnetic shielding (NICS) criteria. The resulting neutral 4N electron molecules possess a 4N π electron perimeter with pronounced CC bond length equalization (as indicated by the HOMA geometric index) and significant aromatic stabilization energies (computed using the isomerization-stabilization method) and could be promising synthetic targets with small HOMO-LUMO gaps.

  8. Inclusion of poly-aromatic hydrocarbon (PAH) molecules in a ...

    Indian Academy of Sciences (India)

    The internal surface of an Mg-Al layered double hydroxide has been functionalized by anchoring carboxy-methyl derivatized -cyclodextrin cavities to the gallery walls. Neutral polyaromatic hydrocarbon (PAH) molecules have been included within the functionalized solid by driving the hydrophobic aromatic molecules from ...

  9. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

  10. Determination of carcinogenic polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Determination of carcinogenic polycyclic aromatic hydrocarbons (pahs), anthracene in different variety of fish samples in the Bangsai river of Bangladesh. F Yeasmin, SMM Rahman, S Rana, KJ Fatema, MA Hossain ...

  11. Hydrocarbon fractions. Aromatic determination by mass spectrometry

    International Nuclear Information System (INIS)

    Anon.

    Analysis of hydrocarbon fractions by mass spectrometry using low energy electrons, for determination of aromatic hydrocarbons repartition, suitable for fraction with the following properties: boiling point up to 320 0 C, whithout olefine, sulfur content up to 0.1 per cent, boiling range up to 100 0 C, if the final temperature is 200 0 C, and up to 50 0 C, if over 200 0 C [fr

  12. Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons ...

    African Journals Online (AJOL)

    DR. GODSON

    Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons (cPAHs) and Heavy. Metal in Crude Oil from Gokana Area, Rivers ... Exploration and production activities of petroleum in the Niger delta, Nigeria has led to the accidental ..... Chemical and bio-geophysical impact of four- dimensional seismic exploration.

  13. Polycyclic aromatic hydrocarbons (PAHs) contamination in coastal ...

    African Journals Online (AJOL)

    The objective of this study was to determine the levels of polycyclic aromatic hydrocarbons (PAHs) in sediments and crabs in the mangrove ecosystems of Zanzibar. Sediments and crabs from eight sampling sites were analysed for eleven selected PAHs. Samples were extracted with dichloromethane by ultrasonication, ...

  14. Determination of carcinogenic polycyclic aromatic hydrocarbons in ...

    African Journals Online (AJOL)

    Determination of carcinogenic polycyclic aromatic hydrocarbons in air samples in Irbid, north Jordan. A Al-Gawadreh Sat, M.B. Gasim, A.R. Hassan, A Azid. Abstract. Air samples were collected at an urban site and a rural (BERQESH) site during February (2017) until March (2017) to determine concentrations of polycyclic ...

  15. Measurements of Polycyclic Aromatic Hydrocarbons and ...

    African Journals Online (AJOL)

    ... with both fluorescence and ultraviolet detection. The genotoxicity was investigated by means of two bacterial assays: the Ames test and the SOS Chromotest. A number of PAHs were identified and genotoxic activity was observed in both of the assays. Keywords: Polycyclic aromatic hydrocarbons, toll plaza, genotoxicity.

  16. Determination of polynuclear aromatic hydrocarbons (PAHs) in ...

    African Journals Online (AJOL)

    Several water bodies in the Niger Delta region of Nigeria where extensive crude oil production activities take place were analyzed for the presence of 16 US EPA priority polynuclear aromatic hydrocarbons (PAHs) namely: naphthalene, acenaphthylene, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene, ...

  17. Adsorption of polynuclear aromatic hydrocarbons from aqueous

    African Journals Online (AJOL)

    ABSTRACT. The adsorption efficiency of a new hybrid clay adsorbent for polynuclear aromatic hydrocarbons. (PAHs) is compared with known modified clay adsorbents. The new hybrid clay adsorbent (HYCA) showed far higher adsorption capacities for the adsorption of various PAH molecules compared with sodium ...

  18. Predicting the Biodegradation of Polycyclic Aromatic Hydrocarbons ...

    African Journals Online (AJOL)

    ... the concentrations of the polycyclic aromatic hydrocarbons, and this was followed by a 'plateau' concentration signifying the attainment of endpoint of the degradation process. Keywords: Model, Neuron, Feed forward, Training, Input, Hidden and Output layers. Journal of the Nigerian Association of Mathematical Physics, ...

  19. (Tpec) of Carcinogenic Polycyclic Aromatic Hydrocarbons (Cpahs)

    African Journals Online (AJOL)

    The aim of this paper is to report the determination of Total potency equivalent concentration (TPEC) of Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in soil samples from Bodo area in Ogoniland using the Toxicity Equivalent Factor (TEF) model. Gas Chromatography GC HP 5870 with FID was used for analysis.

  20. short communication aliphatic and polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. The impact of sunlight on aliphatic and polycyclic aromatic hydrocarbons profiles of Agbabu natural bitumen in Nigeria was investigated. The raw flow type of the bitumen was purified and exposed to sunlight for six consecutive months. Different portions of the bitumen were withdrawn at an interval of one.

  1. Polycyclic aromatic hydrocarbons (PAHs) degradation by laccase ...

    African Journals Online (AJOL)

    Laccase enzyme was produced from an isolate of the white rot fungus, Ganoderma lucidum Chaaim-001 BCU. The enzyme was subsequently evaluated for its degradative ability towards sixteen types of polycyclic aromatic hydrocarbons (PAHs). The G. lucidum laccase degraded antracene completely with or without a ...

  2. Bioremediation of Polycyclic Aromatic Hydrocarbon contaminated ...

    African Journals Online (AJOL)

    This study investigates the effect of lead and chromium on the rate of bioremediation of polycyclic aromatic hydrocarbon (PAH) contaminated clay soil. Naphthalene was used as a target PAH. The soil was sterilized by heating at 120oC for one hour. 100g of the soil was contaminated with lead, chromium, nickel and mercury ...

  3. Transformations of aromatic hydrocarbons over zeolites

    Czech Academy of Sciences Publication Activity Database

    Voláková, Martina; Žilková, Naděžda; Čejka, Jiří

    2008-01-01

    Roč. 34, 5-7 (2008), s. 439-454 ISSN 0922-6168 R&D Projects: GA ČR GA203/05/0197; GA AV ČR 1QS400400560; GA AV ČR KJB4040402 Institutional research plan: CEZ:AV0Z40400503 Keywords : aromatic hydrocarbons * zeolites * alkylation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.514, year: 2008

  4. Water pollution potential of mineral oils with high content of polycyclic aromatic hydrocarbons (heavy fuel oil and neutral oil extracts); Untersuchungen zur Wassergefaehrdung durch Mineraloele mit hohen Gehalten an polycyclischen aromatischen Kohlenwasserstoffen (Heizoel Schwer und Extrakte)

    Energy Technology Data Exchange (ETDEWEB)

    Albers, G. [Mobil Schmierstoff GmbH, Hamburg (Germany)

    1999-01-01

    A data base on highly aromatic mineral oils has been compiled to classify mineral oil products according to their water-pollution potential (water hazard class or Wassergefaehrdungsklasse, WGK). This activity has been undertaken through the Commission for Water Hazardous Materials (Kommission Bewertung Wassergefaehrdender Stoffe, KBwS). In this special case, highly aromatic mineral oils containing a high concentration of polycyclic aromatic hydrocarbons (Polyaromatische Kohlenwasserstoffe, PAK) were evaluated. A test method for measuring the elution potential of PAK into water was developed on petroleum products with high viscosity and high freeze point. This method was applied to determine the solubility of 23 PAK (including 16 PAK according to EPA 610 and 6 PAK according to the German drinking water regulation (Trinkwasserverordnung, TVO)) from heavy fuel oil and neutral oil extract in the aqueous phase. For the 6 PAK, according to TVO, a sum limit of 0,2 {mu}g/l in drinking water is permitted by German legislation. This limit was not exceeded in any of the water phases examined. (orig.) [Deutsch] Fuer die Einstufung von Mineraloelprodukten in die Wassergefaehrdungsklassen (WGK) durch die Kommission Bewertung Wassergefaehrdender Stoffe ist es notwendig, Basisdaten zur Verfuegung zu stellen. Im speziellen Fall handelt es sich um die Bewertung von Mineraloelen, die sich durch einen hohen Gehalt an polycyclischen aromatischen Kohlenwasserstoffen (PAK) auszeichnen. Zur Eluierbarkeit von PAK`s aus Produkten mit hoher Viskosiaet bzw. mit hohem Stockpunkt wurde eine Pruefmethode entwickelt. Diese Methode wurde zur Bestimmung der Loeslichkeit von 23 PAK`s (16 PAK`s nach EPA-Liste incl. 6 PAK`s der TVO) aus den Mineraloelen Heizoel Schwer und Neutralextrakt in der Wasserphase eingesetzt. Fuer die PAK der TVO ist in der TVO ein Summengrenzwert von 0,2 {mu}g/l Trinkwasser angegeben. Dieser Grenzwert wurde in keiner der untersuchten Wasserphasen ueberschritten. (orig.)

  5. Petroleum and individual polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, Peter H.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

    1995-01-01

    Crude petroleum, refined-petroleum products, and individual polycyclic aromatic hydrocarbons (PAHs) contained within petroleum are found throughout the world. their presence has been detected in living and nonliving components of ecosystems. Petroleum can be an environmental hazard for wild animals and plants. Individual PAHs are also hazardous to wildlife, but they are most commonly associated with human illnesses. Because petroleum is a major environmental source of these PAHs, petroleum and PAHs are jointly presented in this chapter. Composition, sources, environmental fate, and toxic effects on all living components of aquatic and terrestrial environments are addessed.

  6. Polycyclic aromatic hydrocarbons profile of kitchen dusts.

    Science.gov (United States)

    Iwegbue, Chukwujindu M A

    2011-03-01

    Concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) were determined in thirty dust samples collected from kitchens that use wood cook system (WCS), kerosene stove cook system (KSCS) and butane gas cook system (BGCS). The total PAHs concentrations ranged from 52 to 497, 39 to 96 and 37 to 155 μg kg(-1) for WCS, KSCS and BGCS respectively. The results indicate predominance of lower molecular weight (2-3 rings) over higher molecular weight PAHs and users of wood cook system are more exposed to higher levels of PAHs than the users of either kerosene cook system or butane gas cook system.

  7. Microbial degradation of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Volkering, F.; Breure, A.M.; Andel, J.G. van

    1992-01-01

    Polycyclic aromatic hydrocarbons (PAH) are hazardous compounds originating from oil, tar, creosote, or from incomplete combustion of fossil fuels. Application of biotechnological techniques for remediation of polluted soils from PAH demonstrated that the high molecular compounds are degraded very slowly, and that the residual concentration of PAH often is too high to permit application of the treated soil. Investigations were started to establish process parameters for optimal biodegradation of PAH. The aim is to achieve a relation between the physical properties of PAH and the biodegradation kinetics in different matrices, in order to identify applicability of biotechnological cleanup methods for waste streams and polluted soil. (orig.) [de

  8. AROMATIC AND POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN A LAMINAR PREMIXED N-BUTANE FLAME. (R825412)

    Science.gov (United States)

    AbstractExperimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane¯oxygen¯argon burner s...

  9. A Review of Polycyclic Aromatic Hydrocarbons and Heavy Metal ...

    African Journals Online (AJOL)

    A Review of Polycyclic Aromatic Hydrocarbons and Heavy Metal Contamination of Fish from Fish Farms. ... Journal of Applied Sciences and Environmental Management ... Polycyclic aromatic hydrocarbons (PAHs) and heavy metals contribute to pollutants in aquaculture facilities and thus need to be further investigated.

  10. Laboratory Investigation of Organic Aerosol Formation from Aromatic Hydrocarbons

    Science.gov (United States)

    Molina, Luisa T.; Molina, Mario J.; Zhang, Renyi

    2006-08-23

    Our work for this DOE funded project includes: (1) measurements of the kinetics and mechanism of the gas-phase oxidation reactions of the aromatic hydrocarbons initiated by OH; (2) measurements of aerosol formation from the aromatic hydrocarbons; and (3) theoretical studies to elucidate the OH-toluene reaction mechanism using quantum-chemical and rate theories.

  11. Polycyclic aromatic hydrocarbons (PAHs) in yogurt samples.

    Science.gov (United States)

    Battisti, Chiara; Girelli, Anna Maria; Tarola, Anna Maria

    2015-01-01

    The concentrations and distributions of major polycyclic aromatic hydrocarbons (PAHs) were determined in 20 kinds of yogurt specimens collected from Italian supermarkets using reversed phase high-performance liquid chromatography equipped with fluorescence detection. The method was validated by determination of recovery percentages, precision (repeatability) and sensitivity (limits of detection) with yogurt samples fortified at 0.25, 0.5 and 1 µg/kg concentration levels. The recovery of 13 PAHs, with the exception of naphthalene and acenaphthene, ranged from 61% to 130% and from 60% to 97% at all the levels for yogurts with low (0.1%) and high (3.9%) fat content, respectively. The method is repeatable with relative standard deviation values yogurts with low and high fats were compared.

  12. Zirconacyclopentadiene-annulated polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kiel, Gavin R.; Ziegler, Micah S.; Tilley, T. Don [Department of Chemistry, University of California, Berkeley, CA (United States)

    2017-04-18

    Syntheses of large polycyclic aromatic hydrocarbons (PAHs) and graphene nanostructures demand methods that are capable of selectively and efficiently fusing large numbers of aromatic rings, yet such methods remain scarce. Herein, we report a new approach that is based on the quantitative intramolecular reductive cyclization of an oligo(diyne) with a low-valent zirconocene reagent, which gives a PAH with one or more annulated zirconacyclopentadienes (ZrPAHs). The efficiency of this process is demonstrated by a high-yielding fivefold intramolecular coupling to form a helical ZrPAH with 16 fused rings (from a precursor with no fused rings). Several other PAH topologies are also reported. Protodemetalation of the ZrPAHs allowed full characterization (including by X-ray crystallography) of PAHs containing one or more appended dienes with the ortho-quinodimethane (o-QDM) structure, which are usually too reactive for isolation and are potentially valuable for the fusion of additional rings by Diels-Alder reactions. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Biosurfactant-enhanced bioremediation of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Bollag, J.M. [Penn State University, University Park, PA (USA). Soil Biochemical Lab.

    2003-07-01

    Biosurfactants are surface-active compounds synthesized by it wide variety of micro-organisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures - lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs) can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released to the environment its a result of spillage of oil and byproducts of coal treatment processes. The low water solubility of PAHs limits their availability to microorganisms, which is a potential problem for bioremediation of PAH-contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of PAHs has potential applications in bioremediation.

  14. Determination and content of polycyclic aromatic hydrocarbons in bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, H.J.; Kaschani, D.T.

    1977-12-01

    The institut for Petrolium Research in Hanover has been engaged for some ten years on the analysis of bitumens. What is now known on the subject from the works of various authors is reviewed here. One of the points dealt with in the report is that, owing to its content of polycyclic aromatic hydrocarbons, bitumen is not a potential carcinogen. The analysis of the polycyclic aromatic hydrocarbons and their results, aromatic hydrocarbons in bitumen vapours and their solubility in water from bitumens are dealt with.

  15. Theoretical studies of the structures and local aromaticity of conjugated polycyclic hydrocarbons using three aromatic indices

    Science.gov (United States)

    Sakai, Shogo; Kita, Yuki

    2013-07-01

    The structures and local aromaticity of some conjugated polycyclic hydrocarbons (from the butadienoid, acene, and phenylene series) are studied using ab initio MO and density functional methods. The aromaticities of the molecules are estimated using three indices: the nucleus-independent chemical shift (NICS), the harmonic oscillator model of aromaticity (HOMA), and the index of deviation from aromaticity (IDA). Assessment of the relationships between the structures and the aromatic indices shows that the IDA values correspond best to the characteristics of the conjugated polycyclic hydrocarbon structures.

  16. High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons

    KAUST Repository

    González-Gaya, Belén

    2016-05-16

    Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

  17. Environmental Remediation: Removal of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nkansah, Marian Asantewah

    2012-11-15

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous persistent semi-volatile organic compounds. They are contaminants that are resistant to degradation and can remain in the environment for long periods due to their high degree of conjugation, and aromaticity. PAHs are present in industrial effluents as products of incomplete combustion processes of organic compounds. Petroleum, coal and shale oil contain extremely complex mixtures of these PAHs, and their transport and refining process can also result in the release of PAHs. It is therefore prudent that such effluents are treated before discharge into the environment. In this project, different approaches to the treatment of PAHs have been investigated. Hydrous pyrolysis has been explored as a potential technique for degrading PAHs in water using anthracene as a model compound. The experiments were performed under different conditions of temperature, substrate, redox systems and durations. The conditions include oxidising systems comprising pure water, hydrogen peroxide and Nafion-SiO2 solid catalyst in water; and reducing systems of formic acid and formic acid / Nafion-SiO2 / Pd-C catalysts to assess a range of reactivities. Products observed in GCMS analysis of the extract from the water phase include anthrone, anthraquinone, xanthone and multiple hydro-anthracene derivatives (Paper I). In addition a modified version of the Nafion-SiO2 solid catalyst in water oxidising system was tested; and reducing systems of formic acid and formic acid / Nafion-SiO2 / Pd-C catalysts were adopted for the conversion of a mixture of anthracene, fluorene and fluoranthene. The rate of conversion in the mixture was high as compared to that of only anthracene (Paper II). Also the use of LECA (Lightweight expanded clay aggregates) as an adsorbent (Paper III) for PAHs (phenanthrene, fluoranthene and pyrene) removal from water has been.(Author)

  18. Strong Correlation Physics in Aromatic Hydrocarbon Superconductors

    Science.gov (United States)

    Capone, Massimo; Giovannetti, Gianluca

    2012-02-01

    We show, by means of ab-initio calculations, that electron-electron correlations play an important role in doped aromatic hydrocarbon superconductors, including potassium doped picene with Tc= 18K [1], coronene and phenanthrene [2]. For the case of picene the inclusion of exchange interactions by means of hybrid functionals reproduces the correct gap for the undoped compound and predicts an antiferromagnetic state for x=3, where superconductivity has been observed [3]. The latter finding is compatible with a sizable value of the correlation strength. The differences between the different compounds are analyzed and results of Dynamical Mean-Field Theory including both correlation effects and electron-phonon interactions are presented. Finally we discuss the consequences of strong correlations in an organic superconductor in relation to the properties of Cs3C60, in which electron correlations drive an antiferromagnetic state [4] but also lead to an enhancement of superconductivity [5]. 1. R. Mitsuhashi et al. Nature 464, 76 (2010)2. X.F. Wang et al, Nat. Comm. 2, 507 (2011)3. G. Giovannetti and M. Capone, Phys. Rev. B 83, 134508 (2011)4. Y. Takabayashi et al., Science 323, 1585 (2009)5. M. Capone et al. Rev. Mod. Phys. 81, 943 (2009

  19. Polycyclic aromatic hydrocarbons in the bakery chain.

    Science.gov (United States)

    Ciecierska, M; Obiedziński, M W

    2013-11-01

    The level of polycyclic aromatic hydrocarbons occurrence and the possibility of their formation in the bakery chain, its raw materials and final products, were examined. Experimental bread baking, with different baking temperatures, was performed in the Warsaw bakery, using cyclothermic deck ovens. PAHs determination was performed by high-pressure liquid chromatography with fluorescent and diode array detectors (HPLC-FLD/DAD) and confirmed by gas chromatography coupled with mass spectrometry (GC/MS). Total content of 19 PAHs in the grain, flour and bran varied from 1.07 to 3.65 μg/kg and, in bread, from 1.59 to 13.6 μg/kg depending on the part of bread and baking temperature. Based on the dough's contamination level and the influence of the baking temperature on the bread's PAHs content, it was confirmed that PAHs are formed during baking. Considering the results of the average dietary exposure to PAHs and the MOE (Margin of Exposure) analysis, it could be concluded that analysed bread and cereal products constitute little concern for consumer health. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.

    2012-01-06

    A systematic study of the preparation of porphyrins with extended conjugation by meso,β-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl 3, dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin β,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,β-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (λ max = 730 nm), coronenyl (λ max = 780 nm), pyrenyl (λ max = 815 nm), and perylenyl (λ max = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the β,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with λ max = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. © 2011 American Chemical Society.

  1. Mechanisms for polycyclic aromatic hydrocarbon degradation by ligninolytic fungi.

    OpenAIRE

    Hammel, K E

    1995-01-01

    Ligninolytic fungi accomplish the partial degradation of numerous aromatic organopollutants. Their ability to degrade polycyclic aromatic hydrocarbons (PAHs) is particularly interesting because eukaryotes were previously considered to be unable to cleave fused-ring aromatics. Recent results indicate that extracellular peroxidases of these fungi are responsible for the initial oxidation of PAHs. Fungal lignin peroxidases oxidize certain PAHs directly, whereas fungal manganese peroxidases co-ox...

  2. Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere

    Science.gov (United States)

    Lopez-Puertas, M.; Dinelli, B. M.; Adriani, A.; Funke, B.; Garcia-Comas, M.; Moriconi, M. L.; D'Aversa, E.; Boersma, C.; Allamandola, L. J.

    2013-01-01

    In this paper, we analyze the strong unidentified emission near 3.28 micron in Titan's upper daytime atmosphere recently discovered by Dinelli et al.We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 micron. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) × 10(exp 4) particles / cubic cm. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is approx 430 u; the mean area is about 0.53 sq. nm; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

  3. Atmospheric behaviors of particulate-bound polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in Beijing, China from 2004 to 2010

    OpenAIRE

    Tang, Ning; Suzuki, Genki; Morisaki, Hiroshi; Tokuda, Takahiro; Yang, Xiaoyang; Zhao, Lixia; Lin, Jinming; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

    2017-01-01

    Airborne particulates were collected at an urban site (site 1) from 2004 to 2010 and at a suburban site (site 2) in 2010 in Beijing. Nine polycyclic aromatic hydrocarbons (PAHs) and five nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The concentrations of PAHs and NPAHs were higher in heating season than in non-heating season at the two sites. Both the concentrations of PAHs an...

  4. Polycyclic Aromatic Hydrocarbons (PAHs) and some Trace metals in ...

    African Journals Online (AJOL)

    Polycyclic Aromatic Hydrocarbons (PAHs) and some Trace metals in Yam, Cassava, Orange and Papaya from two Oil and Gas Flaring Impacted Communities in Southern Nigeria. ... metals in response to contamination. Keywords: PAHs levels; Hydrocarbon contaminant exposure; Food safety; Fruits and tubers.

  5. Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in particulates emitted by motorcycles

    International Nuclear Information System (INIS)

    Pham, Chau Thuy; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

    2013-01-01

    We determined eleven PAHs and four NPAHs in particulates and regulated pollutants (CO, CO 2 , HC, NO x , PM) exhausted from motorcycles to figure out the characteristics of motorcycle exhausts. Fluoranthene and pyrene accounted for more than 50% of the total detected PAHs. Among four detected NPAHs, 6-nitrochrysene and 7-nitrobenz[a]anthracene were the predominant NPAHs and were highly correlated relationship with their parent PAHs (R = 0.93 and 0.97, respectively). The PM and HC emissions tended to be close to the PAH emissions. NO x and NPAHs were negatively correlated. Despite their small engine size, motorcycles emitted much more PM and PAHs, showed stronger PAH-related carcinogenicity and indirect-acting mutagenicity, but weaker NPAH-related direct-acting mutagenic potency than automobiles. This is the first study to analyze both PAHs and NPAHs emitted by motorcycles, which could provide useful information to design the emission regulations and standards for motorcycles such as PM. -- Highlights: ► We characterized PAHs and NPAHs distribution in motorcycle exhausts. ► NPAHs concentrations were about three orders of magnitude lower than those of PAHs. ► We found larger amounts of PM and PAHs in exhaust of motorcycles than of automobiles. ► Motorcycles showed stronger PAH-related toxicity than automobiles. ► Motorcycles showed weaker NPAH-related direct-acting mutagenicity than automobiles. -- Control polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbon in particulates emitted by motorcycles due to their toxic potency

  6. Fate of polynuclear aromatic hydrocarbons in soil

    International Nuclear Information System (INIS)

    Bulman, T.L.; Lesage, S.; Fowlie, P.; Webber, M.D.

    1987-01-01

    A study was performed on the persistence of selected polynuclear aromatic hydrocarbons (PAH's) in soil. Two incubation studies were performed. In the first, a mixture of eight PAH's were added to unacclimated soil at levels of 5 and 50 mg/kg and the concentrations were monitored with time. In the second, C 14 -labelled benzo(a)pyrene or anthracene was added to soil incubated in biometer flasks. Microbial degradation, physical and chemical degradation, volatilization and binding were assessed as mechanisms affecting benzo(a)pyrene and anthracene in soil. The disappearance of PAH's appeared to be related to molecular weight, water solubility, volatility and adsorptivity to soil. The loss during this initial period approximated first order kinetics, in some cases following a lag period. The remaining 2-6% of the added PAH's, however, was lost at a much reduced rate. With the 50 mg/kg level of application, reduced rates of disappearance in later stages resulted in levels five to ten times the background concentration which persisted throughout the 400 days. Degradation of phenanthrene, anthracene, fluoranthene and pyrene at the 5 mg/kg application rate, however, resulted in concentrations close to background levels within 400 days. Either a model other than first order or a combination of two models was required to adequately describe the loss of 99% of the added PAH's. The mechanisms leading to a decrease in PAH concentration, identified through the use of C 14 labelling, were predominantly volatilization and adsorption to soil solids for anthracene and adsorption to soil solids for benzo(a)pyrene. Microbial transformation of benzo(a)pyrene was minimal. 17 refs., 10 figs., 4 tabs

  7. Polycyclic Aromatic Hydrocarbons in Fine Particulate Matter ...

    Science.gov (United States)

    This study measured polycyclic aromatic hydrocarbon (PAH) composition in particulate matter emissions from residential cookstoves. A variety of fuel and cookstove combinations were examined, including: (i) liquid petroleum gas (LPG), (ii) kerosene in a wick stove, (iii) wood (10% and 30% moisture content on a wet basis) in a forced-draft fan stove, and (iv) wood in a natural-draft rocket cookstove. LPG combustion had the highest thermal efficiency (~57%) and the lowest PAH emissions per unit fuel energy, resulting in the lowest PAH emissions per useful energy delivered (MJd). The average benzo[a]pyrene (B[a]P) emission factor for LPG was 0.842 µg/MJd; the emission rate was 0.043 µg/min. The highest PAH emissions were from wood burning in the natural-draft stove (209-700 µg B[a]P/MJd). PAH emissions from kerosene were significantly lower than those from the wood burning in the natural-draft cookstove, but higher than those from LPG. It is expected that in rural regions where LPG and kerosene are unavailable or unaffordable, the forced-draft fan stove may be an alternative because its emission factor (5.17-8.07 µg B[a]P/MJd) and emission rate (0.52-0.57 µg/min) are similar to kerosene (5.36 µg B[a]P/MJd and 0.45 µg/min). Compared with wood combustion emissions, LPG stoves emit less total PAH emissions and less fractions of high molecular weight PAHs. Relatively large variations in PAH emissions from LPG call for additional future tests to identify the major

  8. POLYCYCLIC AROMATIC HYDROCARBON FAR-INFRARED SPECTROSCOPY

    International Nuclear Information System (INIS)

    Boersma, C.; Mattioda, A. L.; Tielens, A. G. G. M.; Allamandola, L. J.; Bauschlicher, C. W. Jr; Ricca, A.; Peeters, E.

    2011-01-01

    The far-IR characteristics of astrophysically relevant polycyclic aromatic hydrocarbons (PAHs) averaging in size around 100 carbon atoms have been studied using the theoretical spectra in the NASA Ames PAH IR Spectroscopic Database. These spectra were calculated using density functional theory. Selections of PAH species are made, grouped together by common characteristics or trends, such as size, shape, charge, and composition, and their far-IR spectra compared. The out-of-plane modes involving the entire molecule are explored in detail, astronomical relevance is assessed, and an observing strategy is discussed. It is shown that PAHs produce richer far-IR spectra with increasing size. PAHs also produce richer far-IR spectra with increasing number of irregularities. However, series of irregular-shaped PAHs with the same compact core have common 'Jumping-Jack' modes that 'pile up' at specific frequencies in their average spectrum. For the PAHs studied here, around 100 carbon atoms in size, this band falls near 50 μm. PAH charge and nitrogen inclusion affect band intensities but have little effect on far-IR band positions. Detailed analysis of the two-dimensional, out-of-plane bending 'drumhead' modes in the coronene and pyrene 'families' and the one-dimensional, out-of-plane bending 'bar' modes in the acene 'family' show that these molecular vibrations can be treated as classical vibrating sheets and bars of graphene, respectively. The analysis also shows that the peak position of these modes is very sensitive to the area of the emitting PAH and does not depend on the particular geometry. Thus, these longest wavelength PAH bands could provide a unique handle on the size of the largest species in the interstellar PAH family. However, these bands are weak. Observing highly excited regions showing the mid-IR bands in which the emission from classical dust peaks at short wavelengths offers the best chance of detecting PAH emission in the far-IR. For these regions

  9. Polycyclic aromatic hydrocarbons in air samples of meat smokehouses

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Olsen, I L; Poulsen, O M

    1992-01-01

    In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors or approx......In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors...

  10. High-resolution gas chromatographic analysis of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons

    International Nuclear Information System (INIS)

    Perez, M.; Gonzalez, D.

    1988-01-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs

  11. Ionized polycyclic aromatic hydrocarbons and the diffuse interstellar bands

    International Nuclear Information System (INIS)

    Crawford, M.K.; Tielens, A.G.G.M.; Allamandola, L.J.

    1985-01-01

    A good case has recently been made that the unidentified infrared emission features arise from positively charged, partially hydrogenated polycyclic aromatic hydrocarbons (PAHs). In the Letter, we suggest that these exceedingly stable ions are also the carriers of the diffuse interstellar bands. Although a large variety of PAH isomers is possible, the more condensed forms are substantially more stable than the less condensed forms and are expected to be dominant in harsh interstellar environment. While neutral PAHs do not absorb in the visible, their ionized counterparts do. Because of their low ionization potential, a substantial fraction of the interstellar PAHs will be ionized. Visible spectra of the most stable PAH cations isolated in glasses are compared directly to the interstellar band spectra. Although the laboratory spectra are on an extremely compressed scale and solid state shifts are present, the comparison is favorable. Since little information is available concerning the spectroscopic properties of these species in the gas phase, a considerable amount of laboratory and theoretical work is called for to test this hypothesis

  12. Polycyclic aromatic hydrocarbons in municipal waste ashes from ...

    African Journals Online (AJOL)

    The levels of isolated polycyclic aromatic hydrocarbons (PAH) in ash residues of wastes from some major waste dumps in Lagos, Nigeria, were determined. The total amounts of the PAH in the ashes were in the range of 0.06 – 0.4 mg/g. The ash from the waste dump that contains the highest level also displayed greatest ...

  13. Source apportionment of polycyclic aromatic hydrocarbon in soil ...

    African Journals Online (AJOL)

    The13C/12C isotopic ratios of polycyclic aromatic hydrocarbons (PHCs) for soil samples collected and preserved from contact with any other source(s) of PAHs except atmospheric, between the years 1865 and 1986 in the United Kingdom, were determined, in order to understand PAHs source apportionment within the ...

  14. Source determination of polynuclear aromatic hydrocarbons in water ...

    African Journals Online (AJOL)

    SERVER

    2008-02-05

    Feb 5, 2008 ... Polynuclear aromatic hydrocarbons in surface water and sediment of Ekpan Creek of the Warri River were determined with GC Perkin-Elmer/Clarius 500. Compositional patterns of the PAHs were used to distinguish their sources in the aquatic system. The three diagnostic selected concentration ratios of.

  15. Effect of Smoking on Polycyclic Aromatic Hydrocarbons (PAHS ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Department of Chemistry, Michael Okpara University of Agriculture, Umudike,. P.M.B 7267, Umuahia, Abia State, Nigeria. ABSTRACT: The effects of smoking on proximate composition, energy values and concentrations of polycyclic aromatic hydrocarbons (PAHs) were studied in raw and smoked samples of catfish (Clarias ...

  16. Biodegradation of Polycyclic Aromatic Hydrocarbons in Crude oil ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Release of crude oil and its products into the environment has resulted in many problems that are of global concern. The objective of this study was to determine effect of Composted Market Waste (CMW) on the degradation of Polycyclic Aromatic Hydrocarbons (PAHs) in crude oil-contaminated soil.

  17. Determination of levels of polycyclic aromatic hydrocarbons in soil ...

    African Journals Online (AJOL)

    Soil samples contaminated with spent motor engine oil collected from Abakaliki auto-mechanic site were analyzed to determine the concentration of polycyclic aromatic hydrocarbon (PAH) components which are often targets in environmental check. Identification and quantification of the PAH components was accomplished ...

  18. Interactions of polyhalogenated aromatic hydrocarbons with thyroid hormone metabolism

    NARCIS (Netherlands)

    Schuur, A.G.

    1998-01-01

    This thesis deals with the possible interactions of polyhalogenated aromatic hydrocarbons and/or their metabolites with thyroid hormone metabolism. This chapter summarizes firstly the effects of thyroid hormone on the induction of biotransformation enzymes by PHAHs. Secondly, the results on

  19. Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by white ...

    African Journals Online (AJOL)

    ... activity, and Pseudotrametes gibbosa had significant potential due to its higher laccase production and more potent degradation of PAHs. This study provides technical support for pollution amelioration using aboriginal white-rot fungus. Key words: White-rot fungus, laccase, polycyclic aromatic hydrocarbons, degradation.

  20. A study of the microbiology and polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    A study was carried out on the drill cuttings from three different oil and gas wells located at Ologbo Community at Edo State with respect to their microbiology and polycyclic aromatic hydrocarbons (PAHs) compositional profile and sources. Isolation and enumeration of heterotrophic bacteria and fungi was carried out using ...

  1. Effect of smoking on Polycyclic Aromatic Hydrocarbons (PAHS ...

    African Journals Online (AJOL)

    The effects of smoking on proximate composition, energy values and concentrations of polycyclic aromatic hydrocarbons (PAHs) were studied in raw and smoked samples of catfish (Clarias gariepinus) and tilapia (Oreochromis niloticus). Crude protein was higher in the tilapia sample for both raw and smoked samples.

  2. Polycyclic aromatic hydrocarbons (PAH) in Danish barbecued meat

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Aaslyng, Margit Dall; Meinert, Lene

    2015-01-01

    Barbecuing is known to result in the formation of polycyclic aromatic hydrocarbons (PAHs). A validated method that employed pressurized liquid extraction (PLE), gel permeation chromatography (GPC) followed by solid phase extraction (SPE) on Silica and analytical determination by GC-MS was applied...

  3. Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria

    Science.gov (United States)

    Tikilili, P. V.; Chirwa, E. M. N.

    2010-01-01

    Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.

  4. Enhancement of aromatic and saturated hydrocarbon by modified ...

    African Journals Online (AJOL)

    Three sediment samples collected from the Qua Iboe River System and eighteen different column packing ratios of silica gel and alumina were used in this investigation. The variation of the composition of the stationary phase (silica gel and alumina, SA) gave different yields of aromatic and saturated hydrocarbons. In all the ...

  5. Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas.

    Science.gov (United States)

    Nwinyi, Obinna C; Ajayi, Oluseyi O; Amund, Olukayode O

    2016-01-01

    The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R(2)=1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site. Copyright © 2016. Published by Elsevier Editora Ltda.

  6. carcinogenic potency of polycyclic aromatic hydrocarbons in soil

    African Journals Online (AJOL)

    Carcinogenic potency of polycyclic aromatic hydrocarbons (PAHs) in soils obtained from seven different sampling locations in Effurun metropolis and its environs of Niger Delta Area of Nigeria were evaluated. The 16 US EPA priority PAHs were determined with GC-MS. The concentrations of individual PAHs observed were ...

  7. An Evaluation of Polycyclic Aromatic Hydrocarbons in Hemichromis ...

    African Journals Online (AJOL)

    The concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) were analysed in Hemichromis fasciatus netted from the Ikpoba reservoir in Benin City, Nigeria, using Gas chromatographic technique, in order to evaluate the potential ecological risk of these organic pollutants on the investigated ecosystem. The mean ...

  8. Biodegradation of polycyclic aromatic hydrocarbons in crude oil ...

    African Journals Online (AJOL)

    Release of crude oil and its products into the environment has resulted in many problems that are of global concern. The objective of this study was to determine effect of Composted Market Waste (CMW) on the degradation of Polycyclic Aromatic Hydrocarbons (PAHs) in crude oil-contaminated soil. Pot experiment was ...

  9. Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in a tropical ...

    African Journals Online (AJOL)

    The distribution of 8 polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of the Grand-Lahou lagoon (Côte d'Ivoire) was investigated using a high performance liquid chromatography (HPLC). The total concentrations of PAHs were between 1.55 and 437.52 μg/g in the dry season. Pyrene, benzo (b) ...

  10. Polycyclic Aromatic Hydrocarbons in Air and their Toxic Potency

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. Polycyclic Aromatic Hydrocarbons in Air and their Toxic Potency. R Mohanraj is currently working as Senior Research. Fellow in Environmental. Impact Assessment (EIA). Division of Salim Ali Centre for Ornithology and Natural. History (SACON),. Coimbatore. His primary interest lies in aerosol.

  11. Polycyclic aromatic hydrocarbons in occupational vs. urban environmental air

    NARCIS (Netherlands)

    Branisteanu, R.; Aiking, H.

    1998-01-01

    Objectives: To evaluate the balance between occupational and environmental exposure to suspended particulate matter (SPM) and polycyclic aromatic hydrocarbons (PAHs), comparison measurements were performed in a coal-fired power plant and the urban atmosphere from the town nearby. Methods: The

  12. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Science.gov (United States)

    Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, V.; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, A.; Hellén, H.; Laakso, L.; Hakola, H.

    2014-07-01

    Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol, which affect human health, crop production and regional climate. Measurements of aromatic hydrocarbons were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (> 10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anticyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for 1 year. Samples were collected twice a week for 2 h during daytime and 2 h during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median (mean) total aromatic hydrocarbon concentrations ranged between 0.01 (0.011) and 3.1 (3.2) ppb. Benzene levels did not exceed the local air quality standard limit, i.e. annual mean of 1.6 ppb. Toluene was the most abundant compound, with an annual median (mean) concentration of 0.63 (0.89) ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found, and no distinct seasonal patterns were

  13. Polynuclear Aromatic Hydrocarbons with Curved Surfaces: Buckyballs

    Energy Technology Data Exchange (ETDEWEB)

    Sygula, Andrzej [Mississippi State Univ., Mississippi State, MS (United States)

    2016-08-15

    The discovery of a new allotropic form of elemental carbon – the fullerenes – and subsequently other novel forms of elemental carbon with pyramidalized surfaces, most notably single-walled and multi-walled carbon nanotubes, introduced a novel structural motif to the polycyclic aromatic hydrocarbons (PAHs) with nonplanar surfaces. Our research program supported by BES DOE grant DE-FG02-04ER15514 has dealt with the synthesis, structural studies, and chemistry of the novel curved-surface PAHs with carbon frameworks structurally related to fullerenes. They are referred to as “buckybowls”. We prepared several new buckybowls and, even more importantly, developed the efficient, gram-scale synthetic methodologies for the preparation of small buckybowls, most notably corannulene (C20H10) and its derivatives. In addition, the employment of the corannulene-based synthons previously developed in our laboratory led to a number of highly nonplanar molecular architectures with two or more corannulene subunits with a potential for the applications as novel materials in separation sciences, nanoelectronics, photovoltaics and catalysis. In collaboration with Professor Angelici (Iowa State) we prepared and characterized several transition metal complexes of corannulene, providing the first structural characterization of η6 metal complexes of buckybowls by a single crystal X-ray diffraction. In addition to the definitive structural characterization of the complexes we demonstrated that the (η6-C6Me6)Ru2+ unit in some relatively stable complexes activate the corannulene ligand to react with proper nucleophiles suggesting that such complexex may be used in catalysis. (Section C). We have explored the efficiency of the dispersion-based interactions of curved-surface conjugated carbon networks by high-level computational models. We showed that the curvature of such networks does not reduce the van der Waals attractions as compared to the planar systems of similar size. We than

  14. Polycyclic aromatic hydrocarbons (PAHs) degradation by laccase ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... 1Plant Biomass Utilization Research Unit, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok. 10330, Thailand. 2Biotechnology Program, Faculty of Science, ..... hydrocarbons: past, present and future applications in bioremediation. J. Ind. Microbiol. Biotechnol. 19: 324-333.

  15. Volatilisation of aromatic hydrocarbons from coal-tar contaminated soil

    International Nuclear Information System (INIS)

    Lindhardt, B.

    1994-09-01

    A study of the non-steady-state volatilisation of organic compounds from coal tar contaminated soil. The observed fluxes from the laboratory experiments were compared with the fluxes predicted by a diffusion model assuming that the behaviour of the compounds was ideal. The diffusive release from unsaturated soil was measured in the laboratory from soil samples originating from a former gasworks site, as well as from soils spiked in the laboratory with a single model compound. The volatilisation from the surface of coal-tar contaminated soil was measured from four samples of sandy soils originating from the same site. The flux was quantified for eleven selected aromatic hydrocarbons. Volatilisation was measured from similar coal tar contaminated soil samples located below a 5 cm layer of uncontaminated and biologically inhibited soil with a an organic carbon content of 1.1% or 0.11%.monocyclic aromatic compounds. The study showed that the flux of volatile aromatic hydrocarbons,the monocyclic and the 2-ringed polycyclic aromatic hydrocarbons from coal tar contaminated soil can be estimated within one order of magnitude by a model concept which assumes that the diffusion of the compounds is independent of each other and the change in the composition of the coal tar during the experimental period can be ignored. ignored. It requires that the distribution coefficients between the coal tar contaminated soil and water are known. Where the contaminated soil resides below uncontaminated soil, degradation of the aromatic hydrocarbons can be expected if the cover layer is aerobic. The degradation will reduce the flux significantly after a period of adaption. (AB)

  16. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, Ville; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, Alex B.; Hellen, H.; Laakso, L.; Hakola, H.

    2014-07-11

    Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours 1 during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass 2 selective detector was used for sample preparation and analysis. Results indicated that the 3 monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. 4 Benzene levels did not exceed local air quality standards. Toluene was the most abundant 5 species, with an annual median concentration of 0.63 ppb. No statistically significant 6 differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be

  17. Strong CH/O interactions between polycyclic aromatic hydrocarbons and water: Influence of aromatic system size.

    Science.gov (United States)

    Veljković, Dušan Ž

    2018-03-01

    Energies of CH/O interactions between water molecule and polycyclic aromatic hydrocarbons with a different number of aromatic rings were calculated using ab initio calculations at MP2/cc-PVTZ level. Results show that an additional aromatic ring in structure of polycyclic aromatic hydrocarbons significantly strengthens CH/O interactions. Calculated interaction energies in optimized structures of the most stable tetracene/water complex is -2.27 kcal/mol, anthracene/water is -2.13 kcal/mol and naphthalene/water is -1.97 kcal/mol. These interactions are stronger than CH/O contacts in benzene/water complex (-1.44 kcal/mol) while CH/O contacts in tetracene/water complex are even stronger than CH/O contacts in pyridine/water complexes (-2.21 kcal/mol). Electrostatic potential maps for different polycyclic aromatic hydrocarbons were calculated and used to explain trends in the energies of interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Occurrence of fungi degrading aromatic hydrocarbons in activated sludge biocenoses

    Directory of Open Access Journals (Sweden)

    Anna Grabińska-Łoniewska

    2014-08-01

    Full Text Available A set of 21 strains of yeast-like microorganisms isolated from biocenoses of aerobic and anaerobic wastewater treatment systems were assayed for their ability to utilize aromatic hydrocarbons as a sole C-source. Basing on the achieved results, the highly biochemically active strains for application in enhancing of wastewaters and exhaust gases purification as well as soil bioremediation were selected.

  19. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    International Nuclear Information System (INIS)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare; Zonca, Alberto

    2013-01-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 × 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  20. Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in Hong Kong marine sediments

    International Nuclear Information System (INIS)

    Zheng, G.J.; Richardson, B.J.

    1999-01-01

    A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour), Tsing Yi North and Tolo Harbour. Petroleum hydrocarbon pollutants in marine sediments are believed to be mainly derived from the transportation of oil, shipping activities, spillages, and industrial, stormwater and waste wastewater discharge. The ratio of unresolved complex mixture (UCM) to n-alkanes, carbon preference index (CPI), and n-C 16 values indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. Pollutant sources appear to be stable and continuing when compared with previous data. (author)

  1. Physico-Chemical Speciation and Ocean Fluxes of Polycyclic Aromatic Hydrocarbons

    National Research Council Canada - National Science Library

    Gustafsson, Orjan

    1997-01-01

    Partitioning of ecotoxicologically significant polycyclic aromatic hydrocarbons (PAHs) to non-aqueous, particularly colloidal and soot, phases results in a decrease in their, directly bioavailable, dissolved fractions...

  2. Ex-situ bioremediation of polycyclic aromatic hydrocarbons in sewage sludge

    DEFF Research Database (Denmark)

    Larsen, Sille Bendix; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAH) are regarded as environmental pollutants. A promising approach to reduce PAH pollution is based on the implementation of the natural potential of some microorganisms to utilize hydrocarbons. In this study Proteiniphilum acetatigenes was used for bioaugmentat...

  3. Exposure to polycyclic aromatic hydrocarbons with special focus on cancer

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2015-03-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are a group of compounds consisting of two or more fused aromatic rings. Most of them are formed during incomplete combustion of organic materials such as wood and fossil fuels, petroleum products, and coal. The composition of PAH mixtures varies with the source and is also affected by selective weathering effects in the environment. PAHs are ubiquitous pollutants frequently found in a variety of environments such as fresh water and marine sediments, the atmosphere, and ice. Due to their widespread distribution, the environmental pollution due to PAHs has aroused global concern. Many PAHs and their epoxides are highly toxic, mutagenic and/or carcinogenic to microorganisms as well as to higher forms of life including humans. The main aim of this review is to provide contemporary information on PAH sources, route of exposure, worldwide emission rate, and adverse effects on humans, especially with reference to cancer.

  4. Prenatal exposure to polycyclic aromatic hydrocarbons/aromatics, BDNF and child development.

    Science.gov (United States)

    Perera, Frederica; Phillips, David H; Wang, Ya; Roen, Emily; Herbstman, Julie; Rauh, Virginia; Wang, Shuang; Tang, Deliang

    2015-10-01

    Within a New York City (NYC) birth cohort, we assessed the associations between polycyclic aromatic hydrocarbon (PAH) and other aromatic DNA adducts and brain derived neurotrophic factor (BDNF) concentrations in umbilical cord blood, and neurodevelopment at age 2 years and whether BDNF is a mediator of the associations between PAH/aromatic-DNA adducts and neurodevelopment. PAH/aromatic-DNA adduct concentrations in cord blood were measured in 505 children born to nonsmoking African-American and Dominican women residing in NYC, and a subset was assessed for neurodevelopment at 2 years using the Bayley Scales of Infant Development Mental Development Index (MDI). A spectrum of PAH/aromatic-DNA adducts was measured using the (32)P-postlabeling assay; DNA adducts formed by benzo[a]pyrene (B[a]P), a representative PAH, were measured by High Performance Liquid Chromatography (HPLC)/fluorescence. BDNF mature protein in cord blood plasma was quantified by an ELISA. Multivariate regression analysis, adjusting for potential confounders, was conducted. PAH/aromatic-DNA adduct concentration measured by postlabeling was inversely associated with BDNF concentration (p=0.02) and with MDI scores at 2 years (p=0.04). BDNF level was positively associated with MDI scores (p=0.003). Restricting to subjects having all three measures (PAH/aromatic-DNA adducts by postlabeling, MDI, and BDNF), results were similar but attenuated (p=0.13, p=0.05, p=0.01, respectively). Associations between B[a]P-DNA adducts and BDNF and B[a]P-DNA adducts and MDI at age 2 years were not significant. At age 3 years, the positive association of BDNF with MDI was not observed. The results at age 2 suggest that prenatal exposure to a spectrum of PAH/aromatic pollutants may adversely affect early neurodevelopment, in part by reducing BDNF levels during the fetal period. However, the same relationship was not seen at age 3. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. CHEMISTRY OF OXIDATION OF POLYCYCLIC AROMATIC HYDROCARBONS BY SOIL PSEUDOMONADS

    Science.gov (United States)

    Rogoff, Martin H.

    1962-01-01

    Rogoff, Martin H. (U.S. Bureau of Mines, Pittsburgh, Pa.). Oxidation of polycyclic aromatic hydrocarbons by soil pseudomonads. J. Bacteriol. 83:998–1004. 1962.—Substitution of phenanthrene by a methyl group at the 9-carbon blocks oxidation of the compound by a resting-cell suspension of a phenanthrene-grown soil pseudomonad. When 2-methylphenanthrene is provided, the oxidation rate is considerably higher; 3-methylphenanthrene is oxidized at a rate intermediate between the other two, even though the methyl group is attached to a carbon directly involved in ring splitting. Cells grown on naphthalene or anthracene oxidize phenanthrene at a much lower rate than cells grown with phenanthrene or 2-methylnaphthalene as the source of carbon. Naphthalene-grown cells also absorb less phenanthrene from aqueous solution than do their phenanthrene-grown counterparts. The data are in keeping with the hypothesis that polynuclear aromatic hydrocarbons attach to the relevant bacterial enzymes at carbon-carbon bonds of high electron density (K regions; localized double bonds), and that the ring-splitting reactions then occur at other bonds on the substrate molecule. The actual bond that undergoes fission is determined by the electronic and steric configurations of the enzyme-substrate complex. When linearly arranged aromatic compounds such as naphthalene or anthracene are attacked, attachment to an enzyme and ring splitting may take place on the same ring; angular aromatic compounds such as phenanthrene afford attachment to an enzyme at a bond in a ring other than the one containing the ring-splitting site. PMID:14493381

  6. Preparation and Aromatic Hydrocarbon Removal Performance of Potassium Ferrate

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2014-01-01

    Full Text Available This experiment adopts the hypochlorite oxidation method to constantly synthesize potassium ferrate. Under the condition of micropolluted source water pH and on the basis of naphthalene, phenanthrene, and pyrene as research objects, the effects of different systems to remove aromatic hydrocarbons were studied. Various oxidation systems to remove phenanthrene intermediate are analyzed and the detailed mechanisms for removal of phenanthrene are discussed. The study found that the main intermediate of potassium ferrate system to transform phenanthrene is 9,10-phenanthraquinone and its area percentage reached 82.66%; that is, 9,10-phenanthraquinone is the key entity to remove phenanthrene.

  7. Environmental polycyclic aromatic hydrocarbons affect androgen receptor activation in vitro

    DEFF Research Database (Denmark)

    Vinggaard, Anne Marie; Hnida, Christina; Larsen, John Christian

    2000-01-01

    Nine structurally different polycyclic aromatic hydrocarbons (PAHs) were tested for their ability to either agonize or antagonize the human androgen receptor (hAR) in a sensitive reporter gene assay based on CHO cells transiently cotransfected with a hAR vector and an MMTV-LUC vector. Benz......, determined in the presence of increasing concentrations of R1881. No cytotoxic effects of the tested compounds were observed as determined either by metabolic reduction using AlamarBlue (up to 20 mu M) or determined in cells transfected with a constitutively active hAR (up to 10 mu M). The well-known ability...

  8. Laboratory rotational spectroscopy of cyano substituted polycyclic aromatic hydrocarbons

    Science.gov (United States)

    McNaughton, Don; Jahn, Michaela K.; Travers, Michael J.; Wachsmuth, Dennis; Godfrey, Peter D.; Grabow, Jens-Uwe

    2018-03-01

    The rotational spectra of the four cyano substituted polycyclic aromatic hydrocarbon (PAH) molecules 1-cyanonaphthalene, 2-cyanonaphthalene, 9-cyanoanthracene and 9-cyanophenanthrene have been recorded in molecular expansions using a Stark modulated millimeterwave spectrometer and a Fourier Transform Microwave spectrometer in the cmwave region. The spectra have been assigned and fitted to provide molecular constants and quadrupole hyperfine constants of sufficient accuracy to enable complete hyperfine structure line predictions for interstellar searches. The data may provide a route into detection of small PAHs in the interstellar medium.

  9. Monitoring of nitropolycyclic aromatic hydrocarbons in food using gas chromatography.

    Science.gov (United States)

    Schlemitz, S; Pfannhauser, W

    1996-07-01

    Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) were determined in different kinds of food. The investigation of food matrices necessitates the development of appropriate analytical procedures for sensitive monitoring and determination of these compounds. The analysis of the nitro-PAHs was carried out by GC/MSD, GC plus mass spectrometry, and GC/NPD (nitrogen-phosphorus detection) GC plus nitrogen-phosphorus detection. Seven nitro-PAHs were positively identified and quantified in vegetables, smoked and grilled foods, oil, tea, coffee and spices.

  10. Measurement of polycyclic aromatic hydrocarbons and other pollutants.

    Science.gov (United States)

    Espigares García, M; Pérez López, J A; Mariscal Larrubia, A; Fernandez-Crehuet, M; Gálvez Vargas, R

    1987-04-01

    A single point study of atmospheric pollution has been carried out in Granada (Spain); suspended particulate matter, sulphur oxides, ammoniac, nitrogen dioxide and polycyclic aromatic hydrocarbons were determined. There were variations in relation to the month and the day of the week. The PAHs have been determined through HPLC, with a mobile phase of acetonitrile-water (75-25). The results of measurements of benzo(a)pyrene were between 1.006 and 0.485 micrograms m-3 in two different periods of sampling.

  11. Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

    Directory of Open Access Journals (Sweden)

    E. V. Lau

    2010-01-01

    Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

  12. The unique aromatic catabolic genes in sphingomonads degrading polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Pinyakong, Onruthai; Habe, Hiroshi; Omori, Toshio

    2003-02-01

    Many members of the sphingomonad genus isolated from different geological areas can degrade a wide variety of polycyclic aromatic hydrocarbons (PAHs) and related compounds. These sphingomonads such as Sphingobium yanoikuyae strain B1, Novosphingobium aromaticivorans strain F199, and Sphingobium sp. strain P2 have been found to possess a unique group of genes for aromatic degradation, which are distantly related with those in pseudomonads and other genera reported so far both in sequence homology and gene organization. Genes for aromatics degradation in these sphingomonads are complexly arranged; the genes necessary for one degradation pathway are scattered through several clusters. These aromatic catabolic gene clusters seem to be conserved among many other sphingomonads such as Sphingobium yanoikuyae strain Q1, Sphingomonas paucimobilis strain TNE12, S. paucimobilis strain EPA505, Sphingobium agrestis strain HV3, and Sphingomonas chungbukensis strain DJ77. Furthermore, some genes for naphthalenesulfonate degradation found in Sphingomonas xenophaga strain BN6 also share a high sequence homology with their homologues found in these sphingomonads. On the other hand, protocatechuic catabolic gene clusters found in fluorene-degrading Sphingomonas sp. strain LB126 appear to be more closely related with those previously found in lignin-degrading S. paucimobilis SYK-6 than the genes in this group of sphingomonads. This review summarizes the information on the distribution of these strains and relationships among their aromatic catabolic genes.

  13. Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components

    Science.gov (United States)

    Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale

    2012-08-01

    Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

  14. GAS-PHASE REACTIONS OF POLYCYCLIC AROMATIC HYDROCARBON ANIONS WITH MOLECULES OF INTERSTELLAR RELEVANCE

    International Nuclear Information System (INIS)

    Demarais, Nicholas J.; Yang Zhibo; Martinez, Oscar; Wehres, Nadine; Bierbaum, Veronica M.; Snow, Theodore P.

    2012-01-01

    We have studied reactions of small dehydrogenated polycyclic aromatic hydrocarbon anions with neutral species of interstellar relevance. Reaction rate constants are measured at 300 K for the reactions of phenide (C 6 H – 5 ), naphthalenide (C 10 H – 7 ), and anthracenide (C 14 H – 9 ) with atomic H, H 2 , and D 2 using a flowing afterglow-selected ion flow tube instrument. Reaction rate constants of phenide with neutral molecules (CO, O 2 , CO 2 , N 2 O, C 2 H 2 , CH 3 OH, CH 3 CN, (CH 3 ) 2 CO, CH 3 CHO, CH 3 Cl, and (CH 3 CH 2 ) 2 O) are also measured under the same conditions. Experimental measurements are accompanied by ab initio calculations to provide insight into reaction pathways and enthalpies. Our measured reaction rate constants should prove useful in the modeling of astrophysical environments, particularly when applied to dense regions of the interstellar and circumstellar medium.

  15. Gas-phase Reactions of Polycyclic Aromatic Hydrocarbon Anions with Molecules of Interstellar Relevance

    Science.gov (United States)

    Demarais, Nicholas J.; Yang, Zhibo; Martinez, Oscar; Wehres, Nadine; Snow, Theodore P.; Bierbaum, Veronica M.

    2012-02-01

    We have studied reactions of small dehydrogenated polycyclic aromatic hydrocarbon anions with neutral species of interstellar relevance. Reaction rate constants are measured at 300 K for the reactions of phenide (C6H- 5), naphthalenide (C10H- 7), and anthracenide (C14H- 9) with atomic H, H2, and D2 using a flowing afterglow-selected ion flow tube instrument. Reaction rate constants of phenide with neutral molecules (CO, O2, CO2, N2O, C2H2, CH3OH, CH3CN, (CH3)2CO, CH3CHO, CH3Cl, and (CH3CH2)2O) are also measured under the same conditions. Experimental measurements are accompanied by ab initio calculations to provide insight into reaction pathways and enthalpies. Our measured reaction rate constants should prove useful in the modeling of astrophysical environments, particularly when applied to dense regions of the interstellar and circumstellar medium.

  16. Anaerobic Degradation of Benzene and Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Meckenstock, Rainer U; Boll, Matthias; Mouttaki, Housna; Koelschbach, Janina S; Cunha Tarouco, Paola; Weyrauch, Philip; Dong, Xiyang; Himmelberg, Anne M

    2016-01-01

    Aromatic hydrocarbons such as benzene and polycyclic aromatic hydrocarbons (PAHs) are very slowly degraded without molecular oxygen. Here, we review the recent advances in the elucidation of the first known degradation pathways of these environmental hazards. Anaerobic degradation of benzene and PAHs has been successfully documented in the environment by metabolite analysis, compound-specific isotope analysis and microcosm studies. Subsequently, also enrichments and pure cultures were obtained that anaerobically degrade benzene, naphthalene or methylnaphthalene, and even phenanthrene, the largest PAH currently known to be degradable under anoxic conditions. Although such cultures grow very slowly, with doubling times of around 2 weeks, and produce only very little biomass in batch cultures, successful proteogenomic, transcriptomic and biochemical studies revealed novel degradation pathways with exciting biochemical reactions such as for example the carboxylation of naphthalene or the ATP-independent reduction of naphthoyl-coenzyme A. The elucidation of the first anaerobic degradation pathways of naphthalene and methylnaphthalene at the genetic and biochemical level now opens the door to studying the anaerobic metabolism and ecology of anaerobic PAH degraders. This will contribute to assessing the fate of one of the most important contaminant classes in anoxic sediments and aquifers. © 2016 S. Karger AG, Basel.

  17. Antifungal activity of polycyclic aromatic hydrocarbons against Ligninolytic fungi

    Directory of Open Access Journals (Sweden)

    Memić Mustafa

    2011-01-01

    Full Text Available Environmental contamination by polycyclic aromatic hydrocarbons (PAHs has caused increasing concern because of their known, or suspected, carcinogenic and mutagenic effects. Polycyclic aromatic hydrocarbons occurring in the environment are usually the result of the incomplete combustion of carbon containing materials. The main sources of severe PAHs contamination in soil come from fossil fuels, i.e. production or use of fossil fuels or their products, such as coal tar and creosote. Creosote is used as a wood preservation for railway ties, bridge timbers, pilling and large-sized lumber. It consists mainly of PAHs, phenol and cresol compounds that cause harmful health effects. Research on biodegradation has shown that a special group of microorganisms, the white-rot fungi and brown-rot fungi, has a remarkable potential to degrade PAHs. This paper presents a study of the antifungal activity of 12 selected PAHs against two ligninolytic fungi Hypoxylon fragiforme (white rot and Coniophora puteana (brown rot. The antifungal activity of PAHs was determined by the disc-diffusion method by measuring the diameter of the zone of inhibition. The results showed that the antifungal activity of the tested PAHs (concentration of 2.5 mmol/L depends on the their properties such as molar mass, solubility in water, values of log Kow, ionization potential and Henry’s Law constant as well as number of aromatic rings, molecule topology or pattern of ring linkage. Among the 12 investigated PAHs, benzo(k fluoranthene with five rings, and pyrene with four cyclic condensed benzene rings showed the highest antifungal activity.

  18. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria Reactivityfactor 21 280-290 Aromatic...

  19. Synthesis of condensed phases containing polycyclic aromatic hydrocarbons fullerenes and nanotubes

    Science.gov (United States)

    Reilly, Peter T. A.

    2004-10-19

    The invention relates to methods for producing polycyclic aromatic hydrocarbons, fullerenes, and nanotubes, comprising: a. heating at least one carbon-containing material to form a condensed phase comprising at least one polycyclic aromatic hydrocarbon; b. collecting at least some of the condensed phase; c. reacting the condensed phase to form fullerenes and/or nanotubes.

  20. Atmospheric behaviors of particulate-bound polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in Beijing, China from 2004 to 2010

    Science.gov (United States)

    Tang, Ning; Suzuki, Genki; Morisaki, Hiroshi; Tokuda, Takahiro; Yang, Xiaoyang; Zhao, Lixia; Lin, Jinming; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

    2017-03-01

    Airborne particulates were collected at an urban site (site 1) from 2004 to 2010 and at a suburban site (site 2) in 2010 in Beijing. Nine polycyclic aromatic hydrocarbons (PAHs) and five nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The concentrations of PAHs and NPAHs were higher in heating season than in non-heating season at the two sites. Both the concentrations of PAHs and NPAHs decreased in the non-heating season but only the concentrations of NPAHs decreased in heating season at site 1, from 2004 to 2010. These findings suggest that source control measures implemented by the city of Beijing helped to reduce air pollution in Beijing. The concentrations of PAHs increased at site 1 in 2010, possibly because of the transport of emissions from windward other areas, such as Shanxi province. Several diagnostic ratios of PAHs and NPAHs showed that the different sources contributed to Beijing's air pollution, although coal combustion was the main source in the heating season and vehicle emission was the main source in the non-heating season. An analysis of physical parameters at Beijing showed that high wind speed can remove atmospheric PAHs and NPAHs in the heating season and that high relative humidity can remove them in the non-heating season.

  1. Polycyclic aromatic hydrocarbons' formation and occurrence in processed food.

    Science.gov (United States)

    Singh, Lochan; Varshney, Jay G; Agarwal, Tripti

    2016-05-15

    Polycyclic aromatic hydrocarbons (PAHs) emerged as an important contaminant group in a gamut of processed food groups like dairy, nuts, herbs, beverages, meat products etc. Different cooking processes and processing techniques like roasting, barbecuing, grilling, smoking, heating, drying, baking, ohmic-infrared cooking etc. contribute towards its formation. The level of PAHs depends on factors like distance from heat source, fuel used, level of processing, cooking durations and methods, whereas processes like reuse, conching, concentration, crushing and storage enhance the amount of PAHs in some food items. This review paper provides insight into the impact of dietary intake of PAHs, its levels and formation mechanism in processed food items and possible interventions for prevention and reduction of the PAHs contamination. The gaps and future prospects have also been assessed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. X-ray excited optical luminescence of polynuclear aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Oestreich, G.J.

    1979-05-01

    X-ray excited optical luminescence (XEOL) coupled with time resolved spectroscopy was employed to analyze polynuclear aromatic hydrocarbons (PAH) in n-alkane solvents at 10 K. A pulsed XEOL system which was designed around minicomputer control of a medical x-ray unit was developed. Computer software which generated variable width x-ray pulses, monitored timing reference pulses, controlled data acquisition, and analyzed data was written. Phosphorescence decay constants of several PAHs were determined. Synthetic mixtures of zone refined PAHs were prepared and time resolved with the pulsed XEOL technique. Analytical results obtained from the five component mixtures of PAHs at the part per million level were tabulated. Systematic improvements and further development of the pulsed XEOL method were considered.

  3. Transport of Polycyclic Aromatic Hydrocarbons in Unsaturated Porous Media

    Science.gov (United States)

    Chahal, Maninder; Flury, Markus

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are complex organic molecules containing 2 or more fused benzene rings. Being hydrophobic and non-polar, PAHs tend to partition to the organic matter in the soil from bulk aqueous phase. Though transport of these contaminants has been well studied in saturated environment, interactive mechanisms of these fluorescent compounds in unsaturated (identified by presence of air-water interface) porous media is still not well understood. We studied is the transport of fluoranthene in unsaturated porous media as facilitated by moving air-water interfaces. Confocal microscopy was used to visualize the interactions of fluoranthene particles in a glass channel packed with quartz glass beads. The packed glass channel was used to mimic a porous media and effects of an advancing and receding capillary fringe on the detachment of fluoranthene.

  4. Biotransformation of polycyclic aromatic hydrocarbons in marine polychaetes

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Giessing, Anders; Rasmussen, Lene Juel

    2008-01-01

    Deposit-feeding polychaetes constitute the dominant macrofauna in marine environments that tend to be depositional centers for organic matter and contaminants. Polychaetes are known to accumulate polycyclic aromatic hydrocarbons (PAHs) from both particulate and dissolved phases but less is known...... about the mechanisms underlying elimination of accumulated PAHs. An important pathway of elimination is through biotransformation which results in increased aqueous solubility of the otherwise hydrophobic PAHs. Biotransformation in marine polychaetes proceeds in a two phased process similar to those...... well studied in vertebrates, phase I enzymes belonging to the Cytochrome P450 (CYP) enzyme family, along with a few phase II enzymes have been identified in marine polychaetes. In this review we aim at highlighting advances in the mechanistic understanding of PAH biotransformation in marine polychaetes...

  5. Secondary electron emission yield: graphite and some aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Cazaux, J

    2005-01-01

    A recent analytical model for the secondary electron emission yield, δ, is successfully applied here to graphite and some aromatic hydrocarbons (xylene, anthracene, phenanthrene and biphenyl). In contrast to the use of conventional constant loss model, this model takes a more realistic account of the in-depth generation of the secondary electrons and permits a good description of the reduced yield curves, δ/δ (max) versus E 0 /E 0 (max) , via a suitable choice of the most probable energy dissipation depth, z C , of primary electrons in these low-density, low atomic-weight materials. Physical information on escape probability and on attenuation length of secondary electrons propagating in the investigated specimens is deduced from the good fit between calculated and experimental yield curves, δ = f(E 0 )

  6. Secondary electron emission yield: graphite and some aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cazaux, J [LASSI/UTAP, Faculte des Sciences, BP1039, 51687 Reims Cedex 2 (France)

    2005-07-21

    A recent analytical model for the secondary electron emission yield, {delta}, is successfully applied here to graphite and some aromatic hydrocarbons (xylene, anthracene, phenanthrene and biphenyl). In contrast to the use of conventional constant loss model, this model takes a more realistic account of the in-depth generation of the secondary electrons and permits a good description of the reduced yield curves, {delta}/{delta}{sub (max)} versus E{sup 0}/E{sup 0}{sub (max)}, via a suitable choice of the most probable energy dissipation depth, z{sub C}, of primary electrons in these low-density, low atomic-weight materials. Physical information on escape probability and on attenuation length of secondary electrons propagating in the investigated specimens is deduced from the good fit between calculated and experimental yield curves, {delta} = f(E{sup 0})

  7. Screening of ectomycorrhizal fungi for degradation of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Braun-Luellemann, A.; Huettermann, A.; Majcherczyk, A. [Goettingen Univ. (Germany). Inst. fuer Forstbotanik

    2000-07-01

    Ectomycorrhizal fungi belonging to 16 species (27 strains) were tested for their ability to degrade polycyclic aromatic hydrocarbons (PAHs): Phenanthrene, chrysene, pyrene and benzo[a]pyrene. Cultivated on a complex liquid medium, most of the fungi tested were able to metabolise these compounds. Approximately 50% of the benzo[a]pyrene was removed by strains of Amanita excelsa, Leccinum versipelle, Suillus grevillei, S. luteus, and S. variegatus during a 4-week incubation period. The same amount of phenanthrene was also metabolised by A. muscaria, Paxillus involutus, and S. grevillei. The degradation of the other two PAHs was, for the most part, less effective. Only S. grevillei was able to remove 50% of the pyrene, whereas Boletus edulis and A. muscaria removed 35% of the chrysene. (orig.)

  8. Polycyclic Aromatic Hydrocarbons and Infrared Astrophysics with Spitzer

    Science.gov (United States)

    Hudgins, Douglas M.; Allamandola, L. J.

    2004-01-01

    Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role that carbon-rich plays in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbons (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry -are recognized throughout the Universe. In this presentation, we will examine the current state of the interstellar PAH model and explore how this data, in conjunction with the unparalleled observational data provided by the Spitzer Space Telescope, can be used to draw ever-deeper insights into the physical and chemical natures of a wide range of astrophysical environments.

  9. Simulated transport of polycyclic aromatic hydrocarbons in artificial streams

    Energy Technology Data Exchange (ETDEWEB)

    Bartell, S.M.; Landrum, P.F.; Giesy, J.P.; Leversee, G.J.

    1981-01-01

    A model was constructed to predict the pattern of flow and accumulation of three polycyclic aromatic hydrocarbons (PAH) (anthracene, naphthalene, and benzo(a)pyrene) in artificial streams located on the Savannah River Plant near Aiken, South Carolina. Predictions were based upon the premise that the fundamental chemistry of individual PAH contains useful information for predictive purposes. Model processes included volatilization, photolysis, sorption to sediments and particulates, and net accumulation by biota. Simulations of anthracene transport were compared to results of an experiment conducted in the streams. The model realistically predicted the concentration of dissolved anthracene through time and space. Photolytic degradation appeared to be a major pathway of anthracene flux from the streams.

  10. Kinetics of biodegradation of mixtures of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lotfabad, S.K.; Gray, M.R. [Alberta Univ., Edmonton (Canada). Dept. of Chemical and Materials Engineering

    2002-11-01

    The kinetics of biodegradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture were determined in a creosote-contaminated soil and in a pristine soil. A competitive-inhibition model was able to represent the kinetics of degradation of PAHs from the creosote-contaminated soil, from the lag phase through to active degradation, but not data from pristine soil with the same PAHs alone and in mixtures. The presence of phenanthrene introduced a lag phase of 4.5 days in the degradation of fluoranthene and 5 days for chrysene. Rapid degradation of pyrene followed a lag phase of circa 5 days, regardless of the presence of other PAHs. These results show that even when kinetics of PAH degradation by mixed cultures appear to follow competitive-inhibition kinetics, the underlying mechanisms may be more complex. (orig.)

  11. Urinary polycyclic aromatic hydrocarbon biomarkers and diabetes mellitus.

    Science.gov (United States)

    Alshaarawy, Omayma; Zhu, Motao; Ducatman, Alan M; Conway, Baqiyyah; Andrew, Michael E

    2014-06-01

    The aim of the current study is to investigate the association of polycyclic aromatic hydrocarbons (PAHs), a group of environmental pollutants, with diabetes mellitus. Animal studies link PAHs to inflammation and subsequent development of diabetes mellitus. In addition, occupational studies suggest that exposure to other aromatic hydrocarbons such as dioxins may be associated with diabetes risk in humans. We examined participants from the merged National Health and Nutrition Examination Survey 2001-2002, 2003-2004 and 2005-2006. Exposures of interest were eight urinary monohydroxy-PAHs. Our outcome was diabetes mellitus defined as a glycohemoglobin level (HbA1c) ≥6.5%, a self-reported physician diagnosis of diabetes or use of oral hypoglycaemic medication or insulin. Analyses were adjusted for age, sex, body mass index, race, alcohol consumption, poverty-income ratio, total cholesterol and serum cotinine. We observed a positive association between urinary biomarkers of 1 and 2-hydroxynapthol, 2-hydroxyphenanthrene and summed low molecular weight (LMW) PAH biomarkers, and diabetes mellitus. Compared with participants with summed LMW PAH biomarkers in the lowest quartile, the multivariable-adjusted OR of diabetes mellitus among those in the highest quartile was 3.1 (95% CI 1.6 to 5.8). Urinary biomarkers of 1 and 2-hydroxynapthol, 2-hydroxyphenanthrene and summed LMW PAH biomarkers are associated with diabetes mellitus in US adults 20-65 years of age. The association of a one-time biomarker of PAH exposure has limitations commonly associated with cross-sectional studies, yet is consistent with experimental animal data and is worthy of additional consideration.

  12. Oxidation kinetics of polycyclic aromatic hydrocarbons by permanganate.

    Science.gov (United States)

    Forsey, Steven P; Thomson, Neil R; Barker, James F

    2010-04-01

    The reactivity of permanganate towards polycyclic aromatics hydrocarbons (PAHs) is well known but little kinetic information is available. This study investigated the oxidation kinetics of a selected group of coal tar creosote compounds and alkylbenzenes in water using permanganate, and the correlation between compound reactivity and physical/chemical properties. The oxidation of naphthalene, phenanthrene, chrysene, 1-methylnaphthalene, 2-methylnaphthalene, acenaphthene, fluorene, carbazole isopropylbenzene, ethylbenzene and methylbenzene closely followed pseudo first-order reaction kinetics. The oxidation of pyrene was initially very rapid and did not follow pseudo first-order kinetics at early times. Fluoranthene was only partially oxidized and the oxidation of anthracene was too fast to be captured. Biphenyl, dibenzofuran, benzene and tert-butylbenzene were non-reactive under the study conditions. The oxidation rate was shown to increase with increasing number of polycyclic rings because less energy is required to overcome the aromatic character of a polycyclic ring than is required for benzene. Thus the rate of oxidation increased in the series naphthalenearomatic sextet theory was used to predict the relative stability of arenes towards ring oxidation by permanganate. 2010 Elsevier Ltd. All rights reserved.

  13. The effects of polycyclic aromatic hydrocarbons on the immune system of fish: A review

    International Nuclear Information System (INIS)

    Reynaud, S.; Deschaux, P.

    2006-01-01

    Polycyclic aromatic hydrocarbons are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. This review summarizes the diverse literature on the effects of these pollutants on innate and acquired immunity in fish and the mechanism of PAH-induced immunotoxicity. Among innate immune parameters, many authors have focused on macrophage activities in fish exposed to polycyclic aromatic hydrocarbons. Macrophage respiratory burst appears especially sensitive to polycyclic aromatic hydrocarbons. Among acquired immune parameters, lymphocyte proliferation appears highly sensitive to polycyclic aromatic hydrocarbon exposure. However, the effects of polycyclic aromatic hydrocarbons on both specific and non-specific immunity are contradictory and depend on the mode of exposure, the dose used or the species studied. In contrast to mammals, fewer studies have been done in fish to determine the mechanism of polycyclic aromatic hydrocarbon-induced toxicity. This phenomenon seems to implicate different intracellular mechanisms such as metabolism by cytochrome P4501A, binding to the Ah-receptor, or increased intracellular calcium. Advances in basic knowledge of fish immunity should lead to improvements in monitoring fish health and predicting the impact of polycyclic aromatic hydrocarbons on fish populations, which is a fundamental ecotoxicological goal

  14. The effects of polycyclic aromatic hydrocarbons on the immune system of fish: A review

    Energy Technology Data Exchange (ETDEWEB)

    Reynaud, S. [Laboratoire d' Ecologie Alpine. UMR CNRS 5553. Universite Joseph Fourier. BP 53. 38041 Grenoble cedex 9 (France) and Laboratory of General and Comparative Immunophysiology, Science Teaching and Research Unit, 123, av. Albert Thomas, 87060 Limoges (France)]. E-mail: stephane.reynaud@ujf-grenoble.fr; Deschaux, P. [Laboratory of General and Comparative Immunophysiology, Science Teaching and Research Unit, 123, av. Albert Thomas, 87060 Limoges (France)

    2006-05-01

    Polycyclic aromatic hydrocarbons are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. This review summarizes the diverse literature on the effects of these pollutants on innate and acquired immunity in fish and the mechanism of PAH-induced immunotoxicity. Among innate immune parameters, many authors have focused on macrophage activities in fish exposed to polycyclic aromatic hydrocarbons. Macrophage respiratory burst appears especially sensitive to polycyclic aromatic hydrocarbons. Among acquired immune parameters, lymphocyte proliferation appears highly sensitive to polycyclic aromatic hydrocarbon exposure. However, the effects of polycyclic aromatic hydrocarbons on both specific and non-specific immunity are contradictory and depend on the mode of exposure, the dose used or the species studied. In contrast to mammals, fewer studies have been done in fish to determine the mechanism of polycyclic aromatic hydrocarbon-induced toxicity. This phenomenon seems to implicate different intracellular mechanisms such as metabolism by cytochrome P4501A, binding to the Ah-receptor, or increased intracellular calcium. Advances in basic knowledge of fish immunity should lead to improvements in monitoring fish health and predicting the impact of polycyclic aromatic hydrocarbons on fish populations, which is a fundamental ecotoxicological goal.

  15. High Temperature Chemistry of Aromatic Hydrocarbons. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Lawrence T. [Boston College, Chestnut Hill, MA (United States). Merkert Chemistry Center, Dept. of Chemistry

    2017-05-15

    The primary goal of this research was to uncover the principal reaction channels available to polycyclic aromatic hydrocarbons (PAHs) at high temperatures in the gas phase and to establish the factors that determine which channels will be followed in varying circumstances. New structure-property relationships for PAHs were also studied. The efficient production of clean energy from fossil fuels will remain a major component of the DOE mission until alternative sources of energy eventually displace coal and petroleum. Hydrocarbons constitute the most basic class of compounds in all of organic chemistry, and as the dominant species in fossil fuels, they figure prominently into the programs of the DOE. Much is already known about the normal chemistry of hydrocarbons under ambient conditions, but far less is known about their intrinsic chemistry at temperatures close to those reached during combustion. An understanding of the fundamental molecular transformations, rearrangements, and interconversions of PAHs at high temperatures in the gas phase, as revealed by careful studies on small, well-designed, molecular systems, provides insights into the underlying chemistry of many important processes that are more complex, such as the generation of energy by the combustion of fossil fuels, the uncatalyzed gasification and liquefaction of coal, the production of fullerenes in fuel-rich flames, and the formation of soot and carcinogenic pollutants in smoke (e.g., benzo[a]pyrene). The rational control of any of these processes, whether it be the optimization of a desirable process or the minimization of an undesirable one, requires a clear knowledge of the basic chemistry that governs the fate of the species involved. Advances in chemistry at the most fundamental level come about primarily from the discovery of new reactions and from new insights into how reactions occur. Harnessing that knowledge is the key to new technologies. The recent commercialization of a combustion

  16. EXPERIMENTAL EVIDENCE FOR THE FORMATION OF HIGHLY SUPERHYDROGENATED POLYCYCLIC AROMATIC HYDROCARBONS THROUGH H ATOM ADDITION AND THEIR CATALYTIC ROLE IN H2 FORMATION

    DEFF Research Database (Denmark)

    Thrower, John; Jørgensen, Bjarke; Friis, Emil Enderup

    2012-01-01

    Mass spectrometry measurements show the formation of highly superhydrogenated derivatives of the polycyclic aromatic hydrocarbon molecule coronene through H atom addition reactions. The observed product mass distribution provides evidence also for abstraction reactions resulting in H2 formation......, in agreement with recent IR measurements. Complementary density functional theory calculations confirm the stability of the observed superhydrogenated species toward spontaneous H and H2 loss indicating that abstraction reactions may be the dominant route to H2 formation involving neutral polycyclic aromatic...... hydrocarbons (PAHs). The results indicate that highly superhydrogenated PAHs could well be formed and could act as efficient catalysts for H2 formation in the interstellar medium in low UV flux regions....

  17. Emission of polycyclic aromatic hydrocarbons from gasohol and ethanol vehicles

    Science.gov (United States)

    de Abrantes, Rui; Vicente de Assunção, João; Pesquero, Célia Regina; Bruns, Roy Edward; Nóbrega, Raimundo Paiva

    The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20-25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A - Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application. Results showed that the total PAH emission factor varied from 41.9 μg km -1 to 612 μg km -1 in the gasohol vehicle, and from 11.7 μg km -1 to 27.4 μg km -1 in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo( a)pyrene toxicity equivalence, emission factors varied from 0.00984 μg TEQ km -1 to 4.61 μg TEQ km -1 for the gasohol vehicle and from 0.0117 μg TEQ km -1 to 0.0218 μg TEQ km -1 in the ethanol vehicle. For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed

  18. Molecular catalytic hydrogenation of aromatic hydrocarbons and hydrotreating of coal liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shiyong; Stock, L.M.

    1996-05-01

    This report presents the results of research on the development of new catalytic pathways for the hydrogenation of multiring aromatic hydrocarbons and the hydrotreating of coal liquids at The University of Chicago under DOE Contract No. DE-AC22-91PC91056. The work, which is described in three parts, is primarily concerned with the research on the development of new catalytic systems for the hydrogenation of aromatic hydrocarbons and for the improvement of the quality of coal liquids by the addition of dihydrogen. Part A discusses the activation of dihydrogen by very basic molecular reagents to form adducts that can facilitate the reduction of multiring aromatic hydrocarbons. Part B examines the hydrotreating of coal liquids catalyzed by the same base-activated dihydrogen complexes. Part C concerns studies of molecular organometallic catalysts for the hydrogenation of monocyclic aromatic hydrocarbons under mild conditions.

  19. Ex-situ bioremediation of polycyclic aromatic hydrocarbons in sewage sludge

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Larsen, S.B.; Karakashev, Dimitar Borisov

    2008-01-01

    Polycyclic aromatic hydrocarbons (PAH) are naturally occurring organic compounds. As a result of anthropogenic activities, PAH concentration has increased in the environment considerably. PAH are regarded as environmental pollutants because they have toxic, mutagenic and carcinogenic effects on l...

  20. Webinar Presentation: Prenatal Exposures to Polycyclic Aromatic Hydrocarbons (PAH) and Childhood Body Mass Index Trajectories

    Science.gov (United States)

    This presentation, Prenatal Exposures to Polycyclic Aromatic Hydrocarbons (PAH) and Childhood Body Mass Index Trajectories, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series held on Feb. 11, 2015.

  1. Geochemical distribution of polycyclic aromatic hydrocarbons in soils and sediments of El-Tabbin, Egypt

    Czech Academy of Sciences Publication Activity Database

    Havelcová, Martina; Melegy, A.; Rapant, S.

    2014-01-01

    Roč. 95, JAN (2014), s. 63-74 ISSN 0045-6535 Institutional support: RVO:67985891 Keywords : polycyclic aromatic hydrocarbons * soils * sediment * contamination Subject RIV: DD - Geochemistry Impact factor: 3.340, year: 2014

  2. Susceptibility of eastern oyster early life stages to road surface polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    2012-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are a class of chemical compounds that are mostly : anthropogenic in nature, and they can become persistent organic contaminants in aquatic : ecosystems. Runoff from impervious surfaces is one of the many ways ...

  3. Phytoremediation mechanisms for polycyclic aromatic hydrocarbons removing from contaminated soils

    Directory of Open Access Journals (Sweden)

    Alagić Slađana Č.

    2015-01-01

    Full Text Available Phytoremediation of polycyclic aromatic hydrocarbons (PAHs from soil aims to degrade them into less toxic/non toxic compounds and limit their further movement by sequestration and accumulation into the vacuoles. Lipophilic organic compounds such as PAHs are bound strongly to the epidermis of the root tissue and are rarely translocated within plant. There are no reports in the literature data of PAHs being completely mineralized by plants. There is little evidence to suggest that PAHs accumulate to significant degree in plants, but there still is a lot of evidences on the ability of various plant species (most often grasses and legumes, to degrade and dissipate these dangerous contaminants. The primary mechanism controlling the dissipation of PAHs is rhizosphere microbial degradation where microbes use PAHs molecules as carbon substrates for growth, which in final, leads to the breakdown or total mineralization of the contaminants. The process is usually augmented by the excretion of root exudates (e.g., sugars, alcohols, acids, enzymes, and the build-up of organic carbon in the soil, so the proper selection of particular plant species represents a critical management decision for PAHs phytoremediation. These facts favor the rhyzoremediation as the best solution for sites contaminated with PAHs.

  4. Source apportionment of polycyclic aromatic hydrocarbons in Louisiana

    Science.gov (United States)

    Han, F.; Zhang, H.

    2017-12-01

    Polycyclic aromatic hydrocarbons (PAHs) in the environment are of significant concern due to their high toxicity that may result in adverse health effects. PAHs measurements at the limited air quality monitoring stations alone are insufficient to gain a complete concept of ambient PAH levels. This study simulates the concentrations of PAHs in Louisiana and identifies the major emission sources. Speciation profiles for PAHs were prepared using data assembled from existing emission profile databases. The Sparse Matrix Operator Kernel Emission (SMOKE) model was used to generate the estimated gridded emissions of 16 priority PAH species directly associated with health risks. The estimated emissions were then applied to simulate ambient concentrations of PAHs in Louisiana for January, April, July and October 2011 using the Community Multiscale Air Quality (CMAQ) model (v5.0.1). Through the formation, transport and deposition of PAHs species, the concentrations of PAHs species in gas phase and particulate phase were obtained. The spatial and temporal variations were analyzed and contributions of both local and regional major sources were quantified. This study provides important information for the prevention and treatment of PAHs in Louisiana.

  5. Environmental forensic principals for sources allocation of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    O'Sullivan, G.; Martin, E.; Sandau, C.D.

    2008-01-01

    Polycyclic aromatic hydrocarbons (PAH) are organic compounds which include only carbon and hydrogen with a fused ring structure containing at least two six-sided benzene rings but may also contain additional fused rings that are not six-sided. The environmental forensic principals for sources allocation of PAHs were examined in this presentation. Specifically, the presentation addressed the structure and physiochemical properties of PAHs; sources and sinks; fate and behaviour; analytical techniques; conventional source identification techniques; and toxic equivalent fingerprinting. It presented a case study where residents had been allegedly exposed to dioxins, PAHs and metals released from a railroad tie treatment plant. The classification of PAHs is governed by thermodynamic properties such as biogenic, petrogenic, and pyrogenic properties. A number of techniques were completed, including chemical fingerprinting; molecular diagnostic ratios; cluster analysis; principal component analysis; and TEF fingerprinting. These techniques have shown that suspected impacted sites do not all share similar PAH signatures indicating the potential for various sources. Several sites shared similar signatures to background locations. tabs., figs

  6. Spatial variation and distribution of polycyclic aromatic hydrocarbons in soil

    Directory of Open Access Journals (Sweden)

    Okoro Duke

    2007-04-01

    Full Text Available An investigative study on polycyclic aromatic hydrocarbons (PAHs in soils of different sampling stations in Effurun metropolis and its environs of the Niger Delta Area of Nigeria was carried out with gas chromatography mass spectrometry (GC-MS. Among the 16 US EPA priority PAHs determined, pyrene was observed to be the most abundant compound at all sites (20 %, followed by fluoranthene (14 %, phenanthrene (12 %, chrysene (10 % and benzo(ghiperylene (6 %. High concentrations of pyrene could be attributed to anthropogenic source such as industrial and vehicular emissions. On the other hand, naphthalene, acenathalene and anthracene accounted for 3.2 %, 1.6 %, and 1.1 %, respectively. The observed trend: Refinery > Ekpan > Enerhen > Water Resources > Alegbo > Ugborikoko > Ugboroke could be attributed to the density of industrial and commercial activities in each area. Clear differences in the total PAH between urban/industrial and rural areas were observed. The results showed that PAH levels in soils from heavily industrial sites were higher in concentrations to the effect that Refinery locations were comparatively higher than all other locations. The higher levels of PAHs observed in the Refinery location are clear indications of combustion emissions and gas flaring from fractionating towers.

  7. Polycyclic aromatic hydrocarbons and pesticides in soil of Vojvodina

    Directory of Open Access Journals (Sweden)

    Pucarević Mira M.

    2004-01-01

    Full Text Available The paper deals with several groups of compounds that represent the most frequent pollutants of soil in the world. The paper also reviews results of long-term studies conducted at the Institute of Field and Vegetable Crops in Novi Sad on the residues of pesticides and polycyclic aromatic hydrocarbons (PAHs in the soil of the Vojvodina Province. The analyzed samples have been found to contain residues of persistent pesticides and their metabolites lindane and its metabolites 6,20 μg/kg, alachlor 3,56 μg/kg, aldrin 2,3 μg/kg, heptachlor epoxide 0,99 μg/kg, chlordane 3,82 μg/kg, DDT and its metabolites 10,77 μg/kg, dieldrin 2,04 μg/kg, endrin 3,57 μg/kg and endrin aldehyde 1,36 μg/kg. Soil samples from Novi Sad municipality contained 53,69 μg/kg of DDT and its metabolites. The values of atrazine ranged from 0,0005 to 0,8 mg/kg. The values of PAHs were 6,64 mg/kg in industrial soil, 4,93 mg/kg in agricultural soil, and 4,55 mg/kg and 5,48 mg/kg in the Novi Sad municipality. The lowest value, 0.83 mg/kg, was found for nonagricultural/nonindustrial soils.

  8. FT-IR spectroscopic studies of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Salisbury, D.W.; Allen, J.E. Jr.; Donn, B.; Moore, W.J.; Khanna, R.K.

    1990-01-01

    Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared absorption coefficients instead of those at the temperature of interest because of the latter's unavailability. The present studies are designed to address the differences between the calculated and experimental thermal emission spectra and to provide information which will be useful in future ultraviolet induced infrared fluorescence studies. The emission spectra have been obtained for temperatures up to 825K using an emission cell designed to mount against an external port of an FT-IR spectrometer. These spectra provide information concerning relative band intensities and peak positions which is unavailable from previous calculations

  9. Determination of Polycyclic Aromatic Hydrocarbons In Exhaled Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Moldoveanu SC

    2014-12-01

    Full Text Available The retention by humans of 20 polycyclic aromatic hydrocarbons (PAHs from mainstream cigarette smoke was evaluated. The analysis was done by a new technique using solid phase extraction (SPE for the cleanup and the concenration of PAHs. The new technique has excellent sensitivity and accuracy, which were necessary for the analysis of the very low levels of PAHs present in the exhaled cigarette smoke. The study was done on a common commercial cigarette with 10.6 mg ‘tar’ by U.S. Federal Trade Commission (FTC recommendation. The results were obtained from ten human subjects, each smoking three cigarettes. The exhaled smoke was collected using a vacuum assisted procedure that avoids strain in exhaling. The study showed that the PAHs with a molecular weight lower than about 170 Daltons are retained with high efficiency. The heavier molecules are less retained, but even compounds such as indeno[1,2,3-cd]pyrene, dibenz[a, h]anthracene, and benzoperylene are retained with efficiencies around 50%. The dependence of retention efficiency for PAHs (in % on their octanol-water partition coefficient (LogPow was found to be nonlinear and showed considerable variability for several compounds that have very close LogPow values. Better correlation was obtained between the retention efficiency and PAHs vapor pressure (Log VP.

  10. Fugacity analysis of polycyclic aromatic hydrocarbons between microplastics and seawater

    Science.gov (United States)

    Lee, Hwang; Chang, Sein; Kim, Seung-Kyu; Kwon, Jung-Hwan

    2017-03-01

    Recently, the accumulation of plastic debris in the marine environment has become a great concern worldwide. Although plastics are biologically and chemically inert, plastic debris has been suspected of causing adverse effects on ecosystems due to the increase in reactivity by size reduction and/or micropollutants associated with plastics. Because of the high sorption capacity of microplastics toward organic micropollutants, it is suspected that microplastics may play roles in the distribution and fate of micropollutants. In order to quantitatively evaluate the "net flow" of environmental contaminants in water-plastic-organism systems, a fugacity analysis was conducted using concentrations of polycyclic aromatic hydrocarbons (PAHs) in open oceans and in polyethylene as a representative material of plastic debris. Ratio of fugacity in polyethylene to that in seawater showed a decreasing trend with increasing partition coefficient between polyethylene and seawater (KPE/sw). This indicates that phase equilibrium between polyethylene and seawater is not attained for higher molecular weight PAHs. Disequilibrium of high molecular weight PAHs suggests that transfer from seawater to plastic debris is thermodynamically driven and the role of plastic debris as a vector to transfer them to living organisms would be minimal. However, additives may slowly migrate from plastics into the environment causing potentially serious effects on ecosystems.

  11. Eisenia fetida increased removal of polycyclic aromatic hydrocarbons from soil

    Energy Technology Data Exchange (ETDEWEB)

    Contreras-Ramos, Silvia M. [Laboratory of Soil Ecology, Department of Biotechnology and Bioengineering, Cinvestav, Av. Instituto Politecnico Nacional 2508, C.P. 07000 Mexico, D.F. (Mexico); Alvarez-Bernal, Dioselina [Laboratory of Soil Ecology, Department of Biotechnology and Bioengineering, Cinvestav, Av. Instituto Politecnico Nacional 2508, C.P. 07000 Mexico, D.F. (Mexico); Dendooven, Luc [Laboratory of Soil Ecology, Department of Biotechnology and Bioengineering, Cinvestav, Av. Instituto Politecnico Nacional 2508, C.P. 07000 Mexico, D.F. (Mexico)]. E-mail: dendoove@cinvestav.mx

    2006-06-15

    The removal of phenanthrene, anthracene and benzo(a)pyrene added at three different concentrations was investigated with or without earthworms (Eisenia fetida) within 11 weeks. Average anthracene removal by the autochthonous micro-organisms was 23%, 77% for phenanthrene and 13% for benzo(a)pyrene, while it was 51% for anthracene, 47% for benzo(a)pyrene and 100% for phenanthrene in soil with earthworms. At 50 and 100 mg phenanthrene kg{sup -1} E. fetida survival was 91% and 83%, but at 150 mg kg{sup -1} all died within 15 days. Survival of E. fetida in soil amended with anthracene {<=}1000 mg kg{sup -1} and benzo(a)pyrene {<=}150 mg kg{sup -1} was higher than 80% and without weight loss compared to the untreated soil. Only small amounts of PAHs were detected in the earthworms. It was concluded that E. fetida has the potential to remove large amounts of PAHs from soil, but more work is necessary to elucidate the mechanisms involved. - Addition of earthworms, Eisenia fetida, accelara removal of polycyclic aromatic hydrocarbons from soil.

  12. Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, C K; Schuepfer, P; Boiteux, P, E-mail: chuynh@hospvd.c [Institute for Work and Health, rue du Bugnon 21, CH-1005 Lausanne (Switzerland)

    2009-02-01

    Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of mug.g{sup -1} or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.

  13. Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust

    International Nuclear Information System (INIS)

    Huynh, C K; Schuepfer, P; Boiteux, P

    2009-01-01

    Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of μg.g -1 or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.

  14. Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Miletić, Tanja; Fermi, Andrea; Orfanos, Ioannis; Avramopoulos, Aggelos; De Leo, Federica; Demitri, Nicola; Bergamini, Giacomo; Ceroni, Paola; Papadopoulos, Manthos G; Couris, Stelios; Bonifazi, Davide

    2017-02-16

    The synthesis of O-doped polyaromatic hydro- carbons in which two polycyclic aromatic hydrocarbon sub units are bridged through one or two O atoms has been achieved. This includes high-yield ring-closure key steps that, depending on the reaction conditions, result in the formation of furanyl or pyranopyranyl linkages through intramolecular C-O bond formation. Comprehensive photophysical measurements in solution showed that these compounds have exceptionally high emission yields and tunable absorption properties throughout the UV/Vis spectral region. Electrochemical investigations showed that in all cases O annulation increases the electron-donor capabilities by raising the HOMO energy level, whereas the LUMO energy level is less affected. Moreover, third-order nonlinear optical (NLO) measurements on solutions or thin films containing the dyes showed very good values of the second hyperpolarizability. Importantly, poly(methyl methacrylate) films containing the pyranopyranyl derivatives exhibited weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, and thus revealed them to be exceptional organic materials for photonic devices. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  15. Slurry reactor bioremediation of soil-bound polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Jones, A.B.; Brinkmann, M.R.; Mahaffey, W.R.

    1992-01-01

    ECOVA Corporation conducted pilot-scale process development studies in 1991 using a slurry-phase biotreatment design to evaluate bioremediation of polycyclic aromatic hydrocarbons (PAHs) in creosote-contaminated soil collected from a superfund site. Bench-scale studies were performed as an antecedent to pilot-scale evaluations in order to collect data which would be used to determine the optimal treatment protocols. This study was performed for the US EPA to supply information as part of the database on Best Demonstrated Available Technology (BDAT) for soil remediation. The database will be used to develop soil standards for land disposal restriction. This paper is a summary of the complete on-site engineering (OER) report is available from the US EPA. The site is a former railroad tie-treating facility. Two surface impoundments were used for the disposal of wastewater generated from wood-treating processes (Resource Conservation and Recovery Act waste code K001). Although all wastewater and liquid creosote have been removed from the impoundments, there is an estimated 12,500 cubic yards of soil and sludge remaining that is contaminated with 2-, 3-, and 4+-ring PAHs. There is also some groundwater contamination restricted to a relatively small area downgradient from the site

  16. Eisenia fetida increased removal of polycyclic aromatic hydrocarbons from soil

    International Nuclear Information System (INIS)

    Contreras-Ramos, Silvia M.; Alvarez-Bernal, Dioselina; Dendooven, Luc

    2006-01-01

    The removal of phenanthrene, anthracene and benzo(a)pyrene added at three different concentrations was investigated with or without earthworms (Eisenia fetida) within 11 weeks. Average anthracene removal by the autochthonous micro-organisms was 23%, 77% for phenanthrene and 13% for benzo(a)pyrene, while it was 51% for anthracene, 47% for benzo(a)pyrene and 100% for phenanthrene in soil with earthworms. At 50 and 100 mg phenanthrene kg -1 E. fetida survival was 91% and 83%, but at 150 mg kg -1 all died within 15 days. Survival of E. fetida in soil amended with anthracene ≤1000 mg kg -1 and benzo(a)pyrene ≤150 mg kg -1 was higher than 80% and without weight loss compared to the untreated soil. Only small amounts of PAHs were detected in the earthworms. It was concluded that E. fetida has the potential to remove large amounts of PAHs from soil, but more work is necessary to elucidate the mechanisms involved. - Addition of earthworms, Eisenia fetida, accelara removal of polycyclic aromatic hydrocarbons from soil

  17. Towards Carbon-Neutral CO2 Conversion to Hydrocarbons.

    Science.gov (United States)

    Mattia, Davide; Jones, Matthew D; O'Byrne, Justin P; Griffiths, Owen G; Owen, Rhodri E; Sackville, Emma; McManus, Marcelle; Plucinski, Pawel

    2015-12-07

    With fossil fuels still predicted to contribute close to 80 % of the primary energy consumption by 2040, methods to limit further CO2 emissions in the atmosphere are urgently needed to avoid the catastrophic scenarios associated with global warming. In parallel with improvements in energy efficiency and CO2 storage, the conversion of CO2 has emerged as a complementary route with significant potential. In this work we present the direct thermo-catalytic conversion of CO2 to hydrocarbons using a novel iron nanoparticle-carbon nanotube (Fe@CNT) catalyst. We adopted a holistic and systematic approach to CO2 conversion by integrating process optimization-identifying reaction conditions to maximize conversion and selectivity towards long chain hydrocarbons and/or short olefins-with catalyst optimization through the addition of promoters. The result is the production of valuable hydrocarbons in a manner that can approach carbon neutrality under realistic industrial process conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Isolation and identification of aromatic hydrocarbon degrading yeasts present in gasoline tanks of urbans vehicles

    Directory of Open Access Journals (Sweden)

    Nathalia Catalina Delgadillo-Ordoñez

    2017-07-01

    Full Text Available Yeast isolates were obtained from fuel tanks of vehicles in order to assess their potential use in the degradation of aromatic hydrocarbons. Growth assays were performed in minimum mineral medium using different aromatic hydrocarbons (benzene, toluene, naphthalene, phenanthrene, and pyrene as the sole carbon source. Isolates that showed growth in any of the tested polycyclic aromatic hydrocarbons were identified by Sanger sequencing of the ITS1 and ITS2 rDNA molecular markers. A total of 16 yeasts strains were isolated, and three showed remarkable growth in media with aromatic hydrocarbons as the sole carbon source. These strains belong to the genus Rhodotorula, and correspond to the species Rhodotorula calyptogenae (99,8% identity and Rhodotorula dairenensis (99,8% identity.  These strains grew in benzene, toluene, naphthalene, phenanthrene and pyrene. This study demonstrates for the first time that yeasts of the genus Rhodotorula inhabit pipelines and fuel tanks of vehicles and that remove   aromatic hydrocarbons that are environmental pollutants. Our results suggest that these yeasts are potential candidates for aromatic hydrocarbon degradation as part of bioremediation strategies.

  19. Probing the spin multiplicity of gas-phase polycyclic aromatic hydrocarbons through their infrared emission spectrum: a theoretical study.

    Science.gov (United States)

    Falvo, Cyril; Calvo, Florent; Parneix, Pascal

    2012-08-14

    The anharmonic infrared emission spectrum following an optical excitation has been calculated for a variety of polycyclic aromatic hydrocarbon molecules in their ground singlet electronic state or in their triplet state. The computational protocol relies on second-order perturbation theory and involves a quartic vibrational Hamiltonian, the vibrational quantum numbers being sampled according to a Monte Carlo procedure. In the case of neutral naphthalene, the IR spectrum obtained in the (ground) singlet state differs significantly from the spectrum in the triplet state, especially for out-of-plane CH bending modes. Although not as prominent, spectral differences in larger molecules are still observable.

  20. UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers

    Science.gov (United States)

    Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.; Gillette, J. S.; Clemett, S. J.; Zare, R. N.

    1999-01-01

    Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.

  1. Polycyclic aromatic hydrocarbons and heavy metals in the Cispata Bay, Colombia: A marine tropical ecosystem.

    Science.gov (United States)

    Burgos-Núñez, Saudith; Navarro-Frómeta, Amado; Marrugo-Negrete, José; Enamorado-Montes, Germán; Urango-Cárdenas, Iván

    2017-07-15

    The concentrations of polycyclic aromatic hydrocarbons and heavy metals were evaluated in shallow sediments, water, fish and seabird samples from the Cispata Bay, Colombia. The heavy metals concentrations in the sediment was in the following order: Cu>Pb>Hg>Cd. The heavy metal concentration was different (pheavy metals in seabirds may be explained by their feeding habits. The presence of polycyclic aromatic hydrocarbons in the Cispata Bay may be due to hydrocarbon spills during oil transport at the nearby oil port. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. STRONG POLYCYCLIC AROMATIC HYDROCARBON EMISSION FROM z ∼ 2 ULIRGs

    International Nuclear Information System (INIS)

    Desai, Vandana; Soifer, B. T.; Melbourne, Jason; Dey, Arjun; Brand, Kate; Brodwin, Mark; Jannuzi, Buell T.; Le Floc'h, Emeric; Armus, Lee; Teplitz, Harry; Brown, Michael J. I.; Houck, James R.; Weedman, Daniel W.; Ashby, Matthew L. N.; Huang Jiasheng; Smith, Howard A.; Willner, Steve P.; Gonzalez, Anthony

    2009-01-01

    Using the Infrared Spectrograph on board the Spitzer Space Telescope, we present low-resolution (64 ν (24 μm)>0.5 mJy; (2) R - [24]>14 Vega mag; and (3) a prominent rest frame 1.6 μm stellar photospheric feature redshifted into Spitzer's 3-8 μm IRAC bands. Of these, 20 show emission from polycyclic aromatic hydrocarbons (PAHs), usually interpreted as signatures of star formation. The PAH features indicate redshifts in the range 1.5 < z < 3.0, with a mean of (z) = 1.96 and a dispersion of 0.30. Based on local templates, these sources have extremely large infrared luminosities, comparable to that of submillimeter galaxies. Our results confirm previous indications that the rest-frame 1.6 μm stellar bump can be efficiently used to select highly obscured star-forming galaxies at z ∼ 2, and that the fraction of starburst-dominated ULIRGs increases to faint 24 μm flux densities. Using local templates, we find that the observed narrow redshift distribution is due to the fact that the 24 μm detectability of PAH-rich sources peaks sharply at z = 1.9. We can analogously use observed spectral energy distributions to explain the broader redshift distribution of Spitzer-detected ULIRGs that are dominated by an active galactic nucleus (AGN). Finally, we conclude that z ∼ 2 sources with a detectable 1.6 μm stellar opacity feature lack sufficient AGN emission to veil the 7.7 μm PAH band.

  3. Polycyclic Aromatic Hydrocarbon Emission Toward the Galactic Bulge

    Science.gov (United States)

    Shannon, M. J.; Peeters, E.; Cami, J.; Blommaert, J. A. D. L.

    2018-03-01

    We examine polycyclic aromatic hydrocarbon (PAH), dust, and atomic/molecular emission toward the Galactic bulge using Spitzer Space Telescope observations of four fields: C32, C35, OGLE, and NGC 6522. These fields are approximately centered on (l, b) = (0.°0, 1.°0), (0.°0, ‑1.°0), (0.°4, ‑2.°4), and (1.°0, ‑3.°8), respectively. Far-infrared photometric observations complement the Spitzer/IRS spectroscopic data and are used to construct spectral energy distributions. We find that the dust and PAH emission are exceptionally similar between C32 and C35 overall, in part explained due to their locations—they reside on or near boundaries of a 7 Myr old Galactic outflow event and are partly shock-heated. Within the C32 and C35 fields, we identify a region of elevated Hα emission that is coincident with elevated fine-structure and [O IV] line emission and weak PAH feature strengths. We are likely tracing a transition zone of the outflow into the nascent environment. PAH abundances in these fields are slightly depressed relative to typical ISM values. In the OGLE and NGC 6522 fields, we observe weak features on a continuum dominated by zodiacal dust. SED fitting indicates that thermal dust grains in C32 and C35 have temperatures comparable to those of diffuse, high-latitude cirrus clouds. Little variability is detected in the PAH properties between C32 and C35, indicating that a stable population of PAHs dominates the overall spectral appearance. In fact, their PAH features are exceptionally similar to that of the M82 superwind, emphasizing that we are probing a local Galactic wind environment.

  4. Generation of polycyclic aromatic hydrocarbons (PAH during woodworking operations

    Directory of Open Access Journals (Sweden)

    Evin Danisman Bruschweiler

    2012-10-01

    Full Text Available Occupational exposures to wood dust have been associated with an elevated risk of sinonasal cancer (SNC. Wood dust is recognized as a human carcinogen but the specific cancer causative agent remains unknown. One possible explanation is a co-exposure to; wood dust and polycyclic aromatic hydrocarbons (PAHs. PAHs could be generated during incomplete combustion of wood due to heat created by use of power tools.To determine if PAHs are generated from wood during common woodworking operations, PAHs concentrations in wood dust samples collected in an experimental chamber operated under controlled conditions were analyzed. In addition, personal air samples from workers exposed to wood dust (n=30 were collected.Wood dust was generated using tree different power tools: vibrating sander, belt sander, and saw; and six wood materials: fir, Medium Density Fiberboard (MDF, beech, mahogany, oak and wood melamine. Monitoring of wood workers was carried out by means of personnel sampler device during wood working operations. We measured 21 PAHs concentrations in wood dust samples by capillary gas chromatographic-ion trap mass spectrometric analysis (GC-MS.Total PAH concentrations in wood dust varied greatly (0.24 – 7.95 ppm with the lowest being in MDF dust and the highest in wood melamine dust. Personal exposures to PAHs observed were between 37.5-119.8 ng m-3 among workers during wood working operations.Our results suggest that PAH exposures during woodworking operation are present and hence could play a role in the mechanism of cancer induction related to wood dust exposure.

  5. Dermal exposure to polycyclic aromatic hydrocarbons among road pavers.

    Science.gov (United States)

    Väänänen, Virpi; Hämeilä, Mervi; Kalliokoski, Pentti; Nykyri, Elina; Heikkilä, Pirjo

    2005-03-01

    Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) and the role of an industrial by-product, coal fly ash, on workers' PAH exposure were investigated during stone mastic asphalt (SMA) paving and remixing. PAH exposure was measured at eight sites during the laying of SMA containing coal fly ash or limestone (conventional SMA) as the filler. Six of the surveys were carried out during SMA paving and two during remixing of SMA (hot recycling at the paving site). Dermal PAH exposure was measured by hand washing (using sunflower oil and wiping with Kleenex tissues) before and after the work shift, and by placing exposure pads on the workers' wrists during the work shift. The analyses included 15 native PAHs from the hand-washing samples determined using high-performance liquid chromatography equipped with a two-channel fluorescence detector and 16 native PAHs and four methylated PAHs from the exposure pads using gas chromatography with mass-selective detection. The PAH results obtained using the pad and hand-washing methods (concentrations after the work shift) were equivalent and showed a strong correlation (r = 0.757, P hand washing. The skin contamination by PAHs was significantly higher (P < 0.01) during remixing than during SMA paving. The variation in PAH contamination on the skin explained more of the variation in the excretion of urinary 1-hydroxypyrene and phenanthrols than the variation in the respiratory PAH concentrations. The industrial by-product investigated in asphalt, coal fly ash, had no statistically significant effect on the workers' dermal PAH exposure. The dermal exposure of paving workers to PAHs was higher during remixing than during SMA paving.

  6. [Exposure of smoking pregnant women to polycyclic aromatic hydrocarbons].

    Science.gov (United States)

    Polańska, Kinga; Hanke, Wojciech; Sobala, Wojciech; Brzeźnicki, Sławomir; Ligocka, Danuta

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are compounds that are formed as a result of incomplete combustion of organic matter. The most common sources of PAHs are cigarette smoke, coal-fired utilities, steel plants, coke-oven plants, graphite electrode manufacturing plant, Söderberg aluminum electrolysis plant, vehicle exhaust, wood-burning ovens and fireplaces, and charcoal-grilled and smoked food. The aim of the study was to assess the exposure of smoking pregnant women to PAHs. The study population consisted of 189 pregnant women from the Lódź voivodeship (province). Smoking status was assessed based on saliva cotinine level analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The cutoff point 10 ng/ml was adopted for saliva cotinine level. 1-hydroxypyrene (1-HP) concentration in urine sample was chosen as the biomarker of exposure to PAHs. The mean concentration of 1-HP in urine of nonsmoking woman was 0.60 microg/g creatinine, whereas in smoking one 1.35 microg/g creatinine. Among the women with saliva cotinine level higher than 10 ng/ml, the mean concentration of 1-HP in urine was over twofold higher than that in women with cotinine level lower than 10 ng/ml after adjustment for the day of urine ample collection (ratio of geometric mean 2.3; 95% CI 1.7-3.0). The study confirmed a higher risk of exposure to PAHs in the group of women who smoke cigarettes during pregnancy as compared to nonsmoking women. It should be stressed that cigarette smoking is not the only source of exposure to PAHs.

  7. Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Karu, A.E.; Li, Q.X.; Roberts, V.A.

    1998-01-01

    'The long-term goal of this project is to develop antibodies and antibody-based methods for detection and recovery of polynuclear aromatic hydrocarbons (PAHs) and PAH adducts that are potential biomarkers in environmental and biological samples. The inherent cross-reactivity will be exploited by pattern recognition methods. Dr. Karu''s laboratory uses new haptens representing key PAHs to derive recombinant Fab (rFab) and single-chain Fv (scFv) antibodies from hybridoma lines and combinatorial phage display libraries. Computational models of the haptens and combining sites made by Dr. Roberts''s group are used to guide antibody engineering by mutagenesis. Dr. Li''s laboratory develops enzyme immunoassays (EIAs), sensors, and immunoaffinity methods that make use of the novel haptens and antibodies for practical analytical applications in support of DOE''s mission. This report summarizes work completed in one and one-half years of a 3-year project, with close collaboration between the three research groups. Dr. Alexander Karu''s laboratory: the authors proceeded with the two strategies described in the original proposal. Site-directed mutagenesis was used to correct differences in the rFab N-terminal amino acids that were introduced by the degenerate PCR primers used for gene amplification. The binding constants of the rFabs with the corrected sequences will be compared with those of the parent MAbs, and should be very similar. The 4D5 and 10C10 heavy and light chain sequences are being moved to the pCOMB3H phagemid vector to facilitate selection of new engineered mutants.'

  8. Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes.

    Science.gov (United States)

    Li, S; Pan, D; Wang, G

    1994-01-01

    Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils and fumes from three catering shops. All samples contained benzo(a)pyrene (BaP) and dibenzo (a,h)anthracene (DBahA). In addition, the concentration of DBahA was 5.7 to 22.8 times higher than that of BaP in the fume samples. Concentrations of BaP and DBahA were, respectively, 0.463 and 5.736 micrograms/g in refined vegetable oil, 0.341 and 3.725 micrograms/g in soybean oil, and 0.305 and 4.565 micrograms/g in vegetable oil. Investigation of PAH concentrations at three catering shops showed that the level of BaP at a Youtiao (deep-fried twisted dough sticks) shop was 4.18 micrograms/100 m3, 2.28 micrograms/100 m3 at a Seqenma (candied fritters) workshop, and 0.49 micrograms/100 m3 at a kitchen of a restaurant; concentrations of DBahA were 33.80, 14.41, and 3.03 micrograms/100 m3, respectively. The high concentration of carcinogens, such as BaP and DBahA, in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma.

  9. New plug flow slurry bioreactor for polycyclic aromatic hydrocarbon degradation

    Energy Technology Data Exchange (ETDEWEB)

    Gamati, S.; Gosselin, C.; Bergeron, E.; Chenier, M.; Truong, T.V. [Sodexen Group, Laval, PQ (Canada); Bisaillon, J.G. [INRS-Inst. Armand-Frappier, Laval, PQ (Canada)

    1999-11-01

    Sodexen Group has developed a new bioslurry bioreactor capable of efficiently and economically treating polycyclic aromatic hydrocarbons (PAHs) contaminated soils and sediments. A pilot plug-flow reactor was constructed, and innovations included were specifically-designed Venturi jet aerators for improved mixing and and oxygen distribution, and the development of bacterial consortia selectively adapted to high molecular weight PAH soil matrices. Rapid biodegradation is provided due to enhanced mass transfer rates and better microorgamism/contaminant contact. Various soil mixtures were tested in a 200 L pilot, and recirculation of a 50% slurry solid concentration was obtained by the use of centrifugal pumps along with submerged aerators and water nozzles. Based on microcosm biodegradation results, specific bioenhancing agents were added to the slurry to optimize bacterial activity and increase substrate bioavailability. Collected volatile organic compounds were treated by a biofilter. The feasibility of operating the continuously fed plug-flow reactor at high slurry solid content was shown. The bioslurry reactor allowed adequate operational conditions and mass transfer rates. Initial operation tests showed that increasing the slurry solid content up to 50% required certain design modifications to move settled particles. These included the number, size, position and distribution of the aerators. Internal shape of the reactor was also changed to obtain adequate mixing and solid suspension. Obtained oxygen levels throughout the reactor showed the efficiency of the aeration system. Resulting PAH removal efficiencies ranged from 63-90% depending on PAH molecular weights. Residence times of about ten days were needed to attain this removal rate. A rapid biodegradation of 80-90% of the more readily-available 2- and 3- ring PHAs occurred. Overall removal rates of more sorbed 4- and 6- ring PHAs were lower, suggesting the need for longer residence times, improved

  10. A bacteriophage system for screening and study of biologically active polycyclic aromatic hydrocarbons and related compounds.

    Science.gov (United States)

    Hsu, W T; Harvey, R G; Lin, E J; Weiss, S B

    1977-01-01

    The usefulness of bacterial viruses for detecting substances that are potentially carcinogenic is reexamined as a model system for screening biologically active polycyclic aromatic hydrocarbons. A modification of the original assay procedure allows one to distinguish between aromatics that can modify the biological activity of infectious nucleic acids directly and those polycyclic aromatic hydrocarbons that require metabolic activation by Escherichia coli enzymes. The effect of chemical modification of several different polycyclic aromatic hydrocarbons, with respect to their biological activity in the phage assay system, is described. Among the 31 different compounds examined, (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide was the most potent inhibitor of infectious phage nucleic acid. The (+) and (-) isomers of the above racemic mixture did not differ significantly in their capacity to inhibit phage replication. PMID:323848

  11. Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

    2003-03-01

    Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

  12. THE EFFECTS OF EQUIVALENCE RATIO ON THE FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOOT IN PREMIXED ETHANE FLAMES. (R825412)

    Science.gov (United States)

    AbstractThe formation of polycyclic aromatic hydrocarbons (PAH) and soot has been investigated in atmospheric-pressure, laminar, ethane/oxygen/argon premixed flames as a function of mixture equivalence ratio. Mole fraction profiles of major products, trace aromatics, ...

  13. Polycyclic aromatic hydrocarbon in fine particulate matter emitted from burning kerosene, liquid petroleum gas, and wood fuels in household cookstoves

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all data in figures in the manuscript and supporting information for the publication entitled "Particulate polycyclic aromatic hydrocarbon...

  14. POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATION LEVELS IN COLLECTED SAMPLES FROM VICINITY OF A HIGHWAY

    Directory of Open Access Journals (Sweden)

    S. V. Samimi ، R. Akbari Rad ، F. Ghanizadeh

    2009-01-01

    Full Text Available Tehran as the biggest city of Iran with a population of more than 10 millions has potentially high pollutant exposures of gas oil and gasoline combustion from vehicles that are commuting in the highways every day. The vehicle exhausts contain polycyclic aromatic hydrocarbons, which are produced by incomplete combustion and can be directly deposited in the environment. In the present study, the presence of polycyclic aromatic hydrocarbons contamination in the collected samples of a western highway in Tehran was investigated. The studied location was a busy highway in Tehran. High performance liquid chromatography equipped with florescence detector was used for determination of polycyclic aromatic hydrocarbons concentrations in the studied samples. Total concentration of the ten studied polycyclic aromatic hydrocarbons compounds ranged from 11107 to 24342 ng/g dry weight in the dust samples and increased from 164 to 2886 ng/g dry weight in the soil samples taken from 300 m and middle of the highway, respectively. Also the average of Σ PAHs was 1759 ng/L in the water samples of pools in parks near the highway. The obtained results indicated that polycyclic aromatic hydrocarbons contamination levels were very high in the vicinity of the highway.

  15. Ecotoxicity of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil.

    Science.gov (United States)

    Eom, I C; Rast, C; Veber, A M; Vasseur, P

    2007-06-01

    Soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (PAHs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. The total concentration of the 16 PAHs listed as priority pollutants by the US Environmental Protection Agency (US-EPA) was 2634+/-241 mg/kgdw in soil samples. The toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (Vibrio fischeri; Microtox test, Daphnia magna) and chronic (Pseudokirchneriella subcapitata, Ceriodaphnia dubia) bioassays and the EC values were expressed as percentage water extract in the test media (v/v). Algal growth (EC50-3d=2.4+/-0.2% of the water extracts) and reproduction of C. dubia (EC50-7d=4.3+/-0.6%) were the most severely affected, compared to bacterial luminescence (EC50-30 min=12+/-3%) and daphnid viability (EC50-48 h=30+/-3%). The Ames and Mutatox tests indicated mutagenicity of water extracts, while no response was found with the umu test. The toxicity of the soil samples was assessed on the survival and reproduction of earthworms (Eisenia fetida) and collembolae (Folsomia candida), and on the germination and growth of higher plants (Lactuca sativa L.: lettuce and Brassica chinensis J.: Chinese cabbage). The EC50 values were expressed as percentage contaminated soil in ISO soil test medium (weight per weight-w/w) and indicated severe effects on reproduction of the collembola F. candida (EC50-28 d=5.7%) and the earthworm E. fetida (EC50-28 d=18% and EC50-56 d=8%, based on cocoon and juvenile production, respectively). Survival of collembolae was already affected at a low concentration of the contaminated soil (EC50-28 d=11%). The viability of juvenile earthworms was inhibited at much lower concentrations of the cokery soil (EC50-14 d=28%) than the viability of adults (EC50-14 d=74%). Only plant growth was inhibited (EC50-17d=26%) while germination was not. Chemical analyses of water extracts allowed

  16. Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

    Energy Technology Data Exchange (ETDEWEB)

    Haritash, A.K., E-mail: akharitash@gmail.com [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India); Kaushik, C.P. [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India)

    2009-09-30

    PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H{sub 2}O, CO{sub 2} (aerobic) or CH{sub 4} (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions

  17. Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

    International Nuclear Information System (INIS)

    Haritash, A.K.; Kaushik, C.P.

    2009-01-01

    PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H 2 O, CO 2 (aerobic) or CH 4 (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can

  18. Polycyclic aromatic hydrocarbons in the South American environment.

    Science.gov (United States)

    Barra, Ricardo; Castillo, Caroline; Torres, Joao Paulo Machado

    2007-01-01

    Pollution of the environment with polycyclic aromatic hydrocarbons (PAHs) should be a global concern, especially in urbanized areas. In South American countries, where notable increase in urban populations has been observed in the past few years, reliable information about the pollution status of these urban environments is not always easily accessible, and therefore an effort to collect updated information is required. This review attempts to contribute by analyzing the existing information regarding environmental levels of PAHs in some South American countries. A regional trend for environmental PAH information is an uneven contribution, because some countries, such as Bolivia, Peru, Paraguay, and Ecuador, have reported no information at all in the scientific literature, reflecting to a certain extent the different patterns of economic, technical, and scientific development. PAH air monitoring is one of the areas that has received the most attention during the last few years, mainly in Brazil, Chile, and Argentina, where data represent a few geographical areas within the region. PAH levels in air from some urban areas in Argentina, Brazil, and Chile, considered moderate to high (100-1000ng/m3), are probably among the highest values reported in the open literature. Urbanization, vehicle pollution, and wood fires are the principal contributors to the high reported levels. In more temperate areas, a clear distinction is observed between summer and winter levels. PAH monitoring in soils is very limited within the region, with few data available, and most information indicates widespread pollution. In Brazil, values for many representative ecosystems were found. In Chile, data from forestry and agricultural areas indicate in general low concentrations, in spite of a relatively high detection frequency. Pollution levels in soils are highly dependent on their closeness to PAH sources and certain cultural practices (agricultural burnings, forest fires, etc.). Water PAH

  19. Polycyclic Aromatic Hydrocarbons in Air and their Toxic Potency

    Indian Academy of Sciences (India)

    Among the urban air pollutants, polycyclic aromatic hydrocar- bons (P AHs) are a large group of over 100 different chemical compounds with 2 to 7 aromatic rings. Large quantities of such compounds are released into environment by various human activities. Recently PAHs in the environment have become.

  20. C-Nucleosides Derived from Simple Aromatic Hydrocarbons

    OpenAIRE

    Chaudhuri, Narayan C.; Ren, Rex X.-F.; Kool, Eric T.

    1997-01-01

    We describe the synthesis, structure and DNA incorporation of a class of novel aromatic C-deoxynucleosides in which benzenes and larger polycyclic aromatics serve as DNA base analogs. Novel approaches have been developed for glycosidic bond formation and for epimenzation of the anomeric substitutents to β-configuration, and we describe some of the properties of such compounds in DNA.

  1. Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Li [Iowa State Univ., Ames, IA (United States)

    1998-03-27

    The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.

  2. [Analysis of aromatic hydrocarbons in cracking products of jet fuel by comprehensive two-dimensional gas chromatography-mass spectrometry].

    Science.gov (United States)

    Li, Haijing; Zhang, Xiangwen

    2017-08-08

    As coking precursors, aromatic hydrocarbons have an effect on the cracking stability of fuels. A method for identifying and quantitating aromatics in the supercritical cracking products of jet fuel was established by comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS). The effects of main chromatographic conditions such as initial oven temperature and modulation period on the separation of supercritical cracking products were studied. The method has good separation ability for polycyclic aromatic hydrocarbons (PAH) isomers. A total of 27 aromatics, including monocyclic aromatic hydrocarbons, bicyclic aromatic hydrocarbons, tricyclic aromatic hydrocarbons, tetracyclic aromatic hydrocarbons, etc., were identified based on standard mass spectra, the retention times of standards and literature reports. Moreover, the corresponding quantitative determination was achieved by external standard method of GC×GC-FID. The results showed that the contents of aromatics increased with the increase of gas yield. When gas yield reached 22%, the bicyclic aromatic hydrocarbons began to produce, and their contents increased exponentially with the increase of gas yield. Compared with the traditional GC-MS, the method has better separation and qualitative ability, and can be applied to the separation of complex samples and qualitative and quantitative analyses of cracking products.

  3. Liquid + liquid equilibria for ternary mixtures of (solvent + aromatic hydrocarbon + alkane)

    International Nuclear Information System (INIS)

    Mohsen-Nia, M.; Modarress, H.; Doulabi, F.; Bagheri, H.

    2005-01-01

    Liquid + liquid equilibrium (LLE) results for the ternary mixtures of (solvent + aromatic hydrocarbon + alkane) at different temperatures from (298.15 to 313.15) K are reported, where the aromatic hydrocarbon is toluene or m-xylene and the alkane is n-heptane or n-octane or cyclohexane and the solvent is tetramethylene sulfone (i.e., sulfolane) or dimethyl sulfoxide (DMSO) or ethylene carbonate. The data were correlated with the UNIQUAC and NRTL equations. The partition coefficients and the selectivity factor of the solvents are calculated. Then, the selectivity of solvents for the extraction of aromatic hydrocarbons from alkanes has been compared. The phase diagrams for the ternary mixtures are presented and the correlated tie line results have been compared with the experimental data. The comparisons indicate the applicability of the UNIQUAC and NRTL activity coefficients model for liquid + liquid equilibrium calculations of the studied mixtures

  4. Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation

    Science.gov (United States)

    Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

    2017-10-01

    The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

  5. Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation.

    Science.gov (United States)

    Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

    2017-10-01

    The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

  6. Biotransformation of the polycyclic aromatic hydrocarbon pyrene in the marine polychaete Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Glessing, Anders M B; Rasmussen, Lene Juel

    2005-01-01

    In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1-hydroxypyr......In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1...

  7. Investigating Superhydrogenated Polycyclic Aromatic Hydrocarbons on HOPG and their catalytic abilities of H2 formation

    DEFF Research Database (Denmark)

    Simonsen, Frederik Doktor Skødt

    Scanning tunneling microscopy and temperature programmed desorption techniques have been used to investigate adsorption and abstraction of hydrogen atoms on the polycyclic aromatic hydrocarbon, coronene. The coronene molecules were exposed to different hydrogen fluences at a dosing temperature...... molecules called polycyclic aromatic hydrocarbons (PAHs). PAHs are believed to account for up to 20% of the available carbon in the ISM and have been observed, with significantly large abundances, alongside H2[2]. Here we investigate the adsorption pattern of hydrogen/deuterium on coronene, C24H12 (a PAH...

  8. Hydrocarbons (aliphatic and aromatic) in the snow-ice cover in the Arctic

    International Nuclear Information System (INIS)

    Nemirovskaya, I.A.; Novigatsky, A.N.; Kluvitkin, A.A.

    2002-01-01

    This paper presented the concentration and composition of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in snow and ice-infested waters in the France-Victoria trough in the northern Barents Sea and in the Mendeleev ridge in the Amerasian basin of the Arctic Ocean. Extreme conditions such as low temperatures, ice sheets and the polar nights render the arctic environment susceptible to oil spills. Hydrocarbons found in these northern seas experience significant transformations. In order to determine the sources, pathways and transformations of the pollutants, it is necessary to know their origin. Hydrocarbon distributions is determined mostly by natural hydrobiological and geochemical conditions. The regularity of migration is determined by natural factors such as formation and circulation of air and ice drift. There is evidence suggesting that the hydrocarbons come from pyrogenic sources. It was noted that hydrocarbons could be degraded even at low temperatures. 17 refs., 1 tab

  9. Polycyclic Aromatic Hydrocarbons in an industrialized urban area

    Science.gov (United States)

    Cachada, A.; Pereira, R.; Ferreira da Silva, E.; Duarte, A. C.

    2009-04-01

    Urbanization, agricultural intensification and industrialization are contributing to erosion, local and diffuse contamination and sealing of soil surfaces, resulting in soil quality degradation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments and considered good markers of anthropogenic activities such as traffic, industry, domestic heating and agriculture. Although they are subject to biodegradation and photodegradation, once in the soil, they tend to bind to the soil organic fraction. Estarreja is a small coastal town in the Northwestern Portuguese coast, with a close relation with the lagoon of Aveiro which supports a variety of biotopes (channels, islands with vegetation, mudflats, salt marshes and agricultural fields) of important ecological value. It supports an intensive and diversified agriculture, a variety of heavy and light industries and a population of about half a million people which is dependent on this resource. This is a very industrialized area, due to its five decades of chemical industry. This study aims to assess the impact of the urbanization and of the chemical industry in PAHs distribution. The survey and sampling method were based on pre-interpreted maps, aerial photographs, and directly checked in the field, in order to get an overall characterization of the area. Topsoils were collected from 34 sites, considering different land uses. Five land uses were chosen: ornamental gardens, parks, roadsides, forest and agricultural. Parameters such as soil pH (ISO method 10390:1994), total C, N, H, S percentages (microanalyser LECO, CNHS-932), organic matter (LOI at 430°), particle size distribution (Micromeritics® Sedigraph 5100), cation exchange capacity and exchangeable bases, were determined in order to have a general characterization of soil. Determination of the 16 EPA PAHs in soils was performed by GC/MS after a Soxhlet extraction and an alumina clean-up of extracts. Procedure blanks, duplicates and reference

  10. Polymorphisms of genes involved in polycyclic aromatic hydrocarbons' biotransformation and atherosclerosis.

    Science.gov (United States)

    Marinković, Natalija; Pasalić, Daria; Potocki, Slavica

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are among the most prevalent environmental pollutants and result from the incomplete combustion of hydrocarbons (coal and gasoline, fossil fuel combustion, byproducts of industrial processing, natural emission, cigarette smoking, etc.). The first phase of xenobiotic biotransformation in the PAH metabolism includes activities of cytochrome P450 from the CYP1 family and microsomal epoxide hydrolase. The products of this biotransformation are reactive oxygen species that are transformed in the second phase through the formation of conjugates with glutathione, glucuronate or sulphates. PAH exposure may lead to PAH-DNA adduct formation or induce an inflammatory atherosclerotic plaque phenotype. Several genetic polymorphisms of genes encoded for enzymes involved in PAH biotransformation have been proven to lead to the development of diseases. Enzyme CYP P450 1A1, which is encoded by the CYP1A1 gene, is vital in the monooxygenation of lipofilic substrates, while GSTM1 and GSTT1 are the most abundant isophorms that conjugate and neutralize oxygen products. Some single nucleotide polymorphisms of the CYP1A1 gene as well as the deletion polymorphisms of GSTT1 and GSTM1 may alter the final specific cellular inflammatory respond. Occupational exposure or conditions from the living environment can contribute to the production of PAH metabolites with adverse effects on human health. The aim of this study was to obtain data on biotransformation and atherosclerosis, as well as data on the gene polymorphisms involved in biotransformation, in order to better study gene expression and further elucidate the interaction between genes and the environment.

  11. Recent Advances in Laboratory Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbons: PAHs in the Far Infrared

    Science.gov (United States)

    Mattioda, Andrew L.; Ricca, Alessandra; Tucker, Jonathan; Boersma, Christiaan; Bauschlicher, Charles, Jr.; Allamandola, Louis J.

    2010-01-01

    Over 25 years of observations and laboratory work have shown that the mid-IR spectra of a majority of astronomical sources are dominated by emission features near 3.3, 6.2, 7.7, and 11.2 microns, which originate in free polycyclic aromatic hydrocarbon (PAH) molecules. PAHs dominate the mid-IR emission from many galactic and extragalactic objects. As such, this material tracks a wide variety of astronomical processes, making this spectrum a powerful probe of the cosmos Apart from bands in the mid-IR, PAHs have bands spanning the Far-IR (FIR) and emission from these FIR features should be present in astronomical sources showing the Mid-IR PAH bands. However, with one exception, the FIR spectral characteristics are known only for a few neutral small PAHs trapped in salt pellets or oils at room temperature, data which is not relevant to astrophysics. Furthermore, since most emitting PAHs responsible for the mid-IR astronomical features are ionized, the absence of any experimental or theoretical PAH ion FIR spectra will make it impossible to correctly interpret the FIR data from these objects. In view of the upcoming Herschel space telescope mission and SOFIA's FIR airborne instrumentation, which will pioneer the FIR region, it is now urgent to obtain PAH FIR spectra. This talk will present an overview recent advances in the laboratory spectroscopy of PAHs, Highlighting the FIR spectroscopy along with some quantum calculations.

  12. Molecular growth in clusters of polycyclic aromatic hydrocarbons induced by collisions with ions

    International Nuclear Information System (INIS)

    Delaunay, Rudy

    2016-01-01

    This thesis concerns the experimental study of the interaction between low energy ions (keV range) and neutral isolated molecules or clusters of polycyclic aromatic hydrocarbons (PAH) in the gas phase. The use of ionising radiations on these complex molecular systems of astrophysical interest allowed to highlight processes of statistical fragmentation, corresponding to the redistribution of the energy through the degrees of freedom of the target, and non-statistical fragmentation, linked to binary collisions of the ions on the nuclei of the target. A mechanism of intermolecular growth in clusters of PAH is observed. It is associated to the ultrafast (≤ ps) formation of fragments inside the clusters following binary collisions. The presence of a molecular environment around the fragments formed during the interaction may initiate a process of reactivity between the fragments and the molecules of the clusters. More precisely, the study focusses on the importance of the electronic stopping power SE and the nuclear stopping power SN of the projectile ion. It shows that the molecular growth is enhanced when SN is higher than SE. This can be explained by the fact that the deposit of energy is mainly due to the interaction with the nuclei of the target. The process of growth has been observed for all the molecules of PAH studied during this thesis and also for nitrogenated analogues of the molecule of anthracene. This demonstrates that molecular growth may be efficiently induced by collisions of low energy ions with clusters of PAH. (author) [fr

  13. Sources and deposition of polycyclic aromatic hydrocarbons to western US national parks

    Science.gov (United States)

    Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) to determine their current and historical deposition, as well as to identify thei...

  14. Extraction of sediment-associated polycyclic aromatic hydrocarbons with granular activated carbon

    NARCIS (Netherlands)

    Rakowska, M.I.; Kupryianchyk, D.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.; Koelmans, A.A.

    2013-01-01

    Addition of activated carbon (AC) to sediments has been proposed as a method to reduce ecotoxicological risks of sediment-bound contaminants. The present study explores the effectiveness of granular AC (GAC) in extracting polycyclic aromatic hydrocarbon (PAH) from highly contaminated sediments. Four

  15. Estrogenic activity of environmental polycyclic aromatic hydrocarbons in uterus of immature Wistar rats

    Czech Academy of Sciences Publication Activity Database

    Kummer, V.; Mašková, J.; Zralý, Z.; Neča, J.; Šimečková, P.; Vondráček, Jan; Machala, M.

    2008-01-01

    Roč. 180, č. 3 (2008), s. 212-221 ISSN 0378-4274 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : polycyclic aromatic hydrocarbons * rat immature uterothrophic assay * estrogen receptor Subject RIV: BO - Biophysics Impact factor: 3.249, year: 2008

  16. Gas-phase infrared spectra of cationized nitrogen-substituted polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Galué, Alvaro; Pirali, O.; Oomens, J.

    2010-01-01

    Gas-phase infrared spectra of several ionized nitrogen substituted polycyclic aromatic hydrocarbons (PANHs) have been recorded in the 600-1600 cm(-1) region via IR multiple-photon dissociation (IRMPD) spectroscopy. The UV photoionized PANH ions are trapped and isolated in a quadrupole ion trap where

  17. "Super-Reducing" Photocatalysis: Consecutive Energy and Electron Transfers with Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Brasholz, Malte

    2017-08-21

    Donation welcome: Recent developments in visible-light photocatalysis allow the utilization of increasingly negative reduction potentials. Successive energy and electron transfer with polycyclic aromatic hydrocarbons enables the catalytic formation of strongly reducing arene radical anions, classical stoichiometric reagents for one-electron reduction in organic synthesis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Polycyclic aromatic hydrocarbon-polluted dredged peat sediments and earthworms: a mutual interference

    NARCIS (Netherlands)

    Eijsackers, H.J.P.; Jonge, de S.; Muijs, B.; Slijkerman, D.; Gestel, van C.A.M.

    2001-01-01

    In lowland areas of the Netherlands, any peat sediments will gradually become enriched with anthropogenically derived Polycyclic Aromatic Hydrocarbons. Due to Dutch policy standards these (anaerobic) sediments are not allowed to be dredged and placed onto land. Under aerobic conditions, however,

  19. Monitoring of occupational exposure to polycyclic aromatic hydrocarbons in a carbon-electrode manufacturing plant

    NARCIS (Netherlands)

    Delft, J.H.M. van; Steenwinkel, M-J.S.T.; Asten, J.G. van; Es, J. van; Kraak, A.; Baan, R.A.

    1998-01-01

    An investigation is presented of occupational exposure to polycyclic aromatic hydrocarbons (PAH) in a carbon-electrode manufacturing plant, as assessed by three monitoring methods, viz, environmental monitoring of the external dose by analysis of personal air samples, biological monitoring of the

  20. COMPARATIVE STUDIES OF THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBON GEOMETRY ON THE HYDROLYSIS OF DIOL EPOXIDES

    Science.gov (United States)

    Comparative studies of the effect of polycyclic aromatic hydrocarbon geometry on the hydrolysis of diol epoxides The interaction of the diol epoxides (DEs) of both planar and non-planar PAHs with water have been examined using quantum mechanical and molecular dynamics. Th...

  1. Gas-phase infrared spectra of cationized nitrogen-substituted polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Galué, H.A.; Pirali, O.; Oomens, J.

    2010-01-01

    Gas-phase infrared spectra of several ionized nitrogen substituted polycyclic aromatic hydrocarbons (PANHs) have been recorded in the 600-1600 cm-1 region via IR multiple-photon dissociation (IRMPD) spectroscopy. The UV photoionized PANH ions are trapped and isolated in a quadrupole ion trap where

  2. Extinction and Polycyclic Aromatic Hydrocarbon Intensity Variations across the H II Region IRAS 12063-6259

    NARCIS (Netherlands)

    Stock, D.; Peeters, E.; Tielens, A.G.G.M.; Otaguro, J.; Bik, A.

    2013-01-01

    The spatial variations in polycyclic aromatic hydrocarbon (PAH) band intensities are normally attributed to the physical conditions of the emitting PAHs, however in recent years it has been suggested that such variations are caused mainly by extinction. To resolve this question, we have obtained

  3. Effect of three polycyclic aromatic hydrocarbons on nodulation of Rhizobium tropici CIAT 899 on Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Paredes, Y.; Ferrera-Cerrato, R.; Alarcon, A.

    2009-07-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous organic pollutants that are considered toxic and carcinogenic compounds to living organisms. There us scarce information about the effect of PAH on symbiotic systems such as Azolla-Anabaena, arbuscular mycorrhizal fungi-plants, or legume-rhizobia. (Author)

  4. DEGRADATION OF POLYNUCLEAR AROMATIC HYDROCARBONS UNDER BENCH-SCALE COMPOST CONDITIONS

    Science.gov (United States)

    The relationship between biomass growth and degradation of polynuclear aromatic hydrocarbons (PAHs) in soil, and subsequent toxicity reduction, was evaluated in 10 in-vessel, bench-scale compost units. Field soil was aquired from the Reilly Tar and Chemical Company Superfund site...

  5. Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Jonker, M.T.O.; Sinke, A.; Brils, J.M.; Murk, A.J.; Koelmans, A.A.

    2006-01-01

    Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAHs), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a

  6. Environmental exposure to carcinogenic polycyclic aromatic hydrocarbons – the interpretation of cytogenetic analysis by FISH

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim; Beskid, Olena; Rössnerová, Andrea; Rössner st., Pavel; Lněničková, Zdena; Milcová, Alena; Solansky, I.; Binková, Blanka

    2007-01-01

    Roč. 172, - (2007), s. 12-20 ISSN 0378-4274 R&D Projects: GA MŽP SL/5/160/05 Institutional research plan: CEZ:AV0Z50390512 Keywords : environmental pollution * carcinogenic polycyclic aromatic hydrocarbons * cytogenetic analysis Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.826, year: 2007

  7. Degradation and utilization of polycyclic aromatic hydrocarbons by indigenous soil bacteria

    International Nuclear Information System (INIS)

    Stetzenbach, L.D.A.

    1986-01-01

    The persistence of industrially derived polycyclic aromatic hydrocarbons in the subsurface may be significantly affected by the metabolism of soil bacteria. This study was conducted to determine the ability of indigenous soil bacteria to decrease the concentration of four polycyclic aromatic hydrocarbons (naphthalene, fluorene, anthracene, and pyrene) and to utilize the compounds as a substrate for growth. Soil cores from petroleum contaminated and noncontaminated sites contained 10 5 -10 7 viable microorganisms per gram dryweight of soil. Gram negative rod-shaped bacteria predominated. Decreases in the concentration of the four polycyclic aromatic hydrocarbons were observed during incubation with bacterial isolates in aqueous suspension by the use of high performance liquid chromatography. Corresponding increases in bacterial numbers indicated utilization of the compounds as a carbon source. Soil samples from the contaminated sites contained greater numbers of bacteria utilizing anthracene and pyrene than soil samples from uncontaminated sites. Degradation rates of the four polycyclic aromatic hydrocarbons were related to the compound, its concentration, and the bacterium. Biodegradation of pyrene was positively correlated with the presence of oxygen. Pyrene was biodegraded by an Acinetobacter sp. under aerobic conditions but not under anaerobic or microaerophilic conditions. Studies with radiolabeled 14 C-anthracene demonstrated utilization of the labeled carbon as a source of carbon by viable bacterial cells in aqueous suspension. Incorporation of 14 C into cellular biomass however was not observed during incubation of 14 C-anthracene in soil

  8. Polymorphisms in DNA repair genes, traffic-related polycyclic aromatic hydrocarbon exposure and breast cancer incidence

    Czech Academy of Sciences Publication Activity Database

    Mordukhovich, I.; Beyea, J.; Herring, A. H.; Hatch, M.; Stellman, S. D.; Teitelbaum, S. L.; Richardson, D.B.; Millikan, R. C.; Engel, L.S.; Shantakumar, S.; Steck, S.E.; Neugut, A. I.; Rössner ml., Pavel; Santella, R. M.; Gammon, M. D.

    2016-01-01

    Roč. 139, č. 2 (2016), s. 310-321 ISSN 0020-7136 Institutional support: RVO:68378041 Keywords : traffic * DNA repair * polycyclic aromatic hydrocarbons * breast cancer Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 6.513, year: 2016

  9. Influence of the bioaccessible fraction of polycyclic aromatic hydrocarbons on the ecotoxicity of historically contaminated soils

    Czech Academy of Sciences Publication Activity Database

    Čvančarová, Monika; Křesinová, Zdena; Cajthaml, Tomáš

    2013-01-01

    Roč. 254, JUN 15 (2013), s. 116-124 ISSN 0304-3894 R&D Projects: GA TA ČR TE01020218; GA TA ČR TA01020106 Institutional support: RVO:61388971 Keywords : Bioavailability * Polycyclic aromatic hydrocarbons * Ecotoxicity Subject RIV: EE - Microbiology, Virology Impact factor: 4.331, year: 2013

  10. Correlation of levels of volatile versus carcinogenic particulate polycyclic aromatic hydrocarbons in air samples from smokehouses

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Christensen, J M

    1991-01-01

    In the present study, data on the concentration of polycyclic aromatic hydrocarbons (PAH) in air samples from fish smokehouses (Nordholm et al. 1986) and meat smokehouses (Hansen et al. submitted for publication) were used to analyze the extent to which six different volatile PAH compounds could...

  11. A 25-year record of polycyclic aromatic hydrocarbons in soils amended with sewage sludges

    DEFF Research Database (Denmark)

    Lichtfouse, Eric; Sappin-Didier, Valérie; Denaix, Laurence

    2005-01-01

    We studied polycyclic aromatic hydrocarbons (PAHs) in crop soils amended with 1000 tonnes dry weight of sewage sludges per 10,000 m(2) from 1974 to 1992, then after sludges addition from 1993 to 1999. The absence of variations of total PAHs levels of control soils, averaging at 123 mu g/Kg, shows...

  12. Moss as bio-indicators of human exposure to polycyclic aromatic hydrocarbons in Portland, OR

    Science.gov (United States)

    Geoffrey H. Donovan; Sarah E. Jovan; Demetrios Gatziolis; Vicente J. Monleon

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a class of air pollutants linked to a wide range of adverse health outcomes, including asthma, cancers, cardiovascular disease, and fetal growth impairment. PAHs are emitted by combustion of organic matter (e.g. fossil fuels, plant biomass) and can accumulate in plant and animal tissues over time. Compared to criteria...

  13. Particle in a Disk: A Spectroscopic and Computational Laboratory Exercise Studying the Polycyclic Aromatic Hydrocarbon Corannulene

    Science.gov (United States)

    Frey, E. Ramsey; Sygula, Andrzej; Hammer, Nathan I.

    2014-01-01

    This laboratory exercise introduces undergraduate chemistry majors to the spectroscopic and theoretical study of the polycyclic aromatic hydrocarbon (PAH), corannulene. Students explore the spectroscopic properties of corannulene using UV-vis and Raman vibrational spectroscopies. They compare their experimental results to simulated vibrational…

  14. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments from Khuzestan province, Iran

    DEFF Research Database (Denmark)

    Lübeck, Josephine; Poulsen, Kristoffer Gulmark; Knudsen, Sofie B.

    2016-01-01

    of polycyclic aromatic hydrocarbon (PAH) pollution. A four-component principal component analysis (PCA) model was obtained. While principal component 1 (PC1) was related to the total concentration of PAHs, the remaining PCs described three distinct sources: PC2 and PC3 collectively differentiate between...

  15. Elimination and accumulation of polycyclic aromatic hydrocarbons (PAHs) in urban stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Istenič, Daria; Arias, Carlos Alberto; Matamoros, Victor

    2011-01-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of seven wet detention ponds receiving urban stormwater were investigated. The ponds comprised traditional wet detention ponds with a permanent wet volume and a storage volume as well as ponds that were expanded...

  16. Enhanced diffusion of polycyclic aromatic hydrocarbons in artificial and natural aqueous solutions

    DEFF Research Database (Denmark)

    Mayer, Philipp; Fernqvist, M.M.; Christensen, P.S.

    2007-01-01

    Uptake of hydrophobic organic compounds into organisms is often limited by the diffusive transport through a thin boundary layer. Therefore, a microscale diffusion technique was applied to determine the diffusive mass transfer of 12 polycyclic aromatic hydrocarbons through water, air, surfactant...

  17. Draft Genome Sequence of Advenella kashmirensis Strain W13003, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

    Science.gov (United States)

    Jin, Decai; Zhou, Lisha; Wu, Liang; An, Wei; Zhao, Lin

    2014-01-01

    Advenella kashmirensis strain W13003 is a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated marine sediments. Here, we report the 4.8-Mb draft genome sequence of this strain, which will provide insights into the diversity of A. kashmirensis and the mechanism of PAH degradation in the marine environment. PMID:24482505

  18. Degradation of polycyclic aromatic hydrocarbons by hydrogen peroxide catalyzed by heterogeneous polymeric metal chelates

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Cajthaml, Tomáš; Merhautová, Věra; Gabriel, Jiří; Nerud, František; Stopka, P.; Hrubý, Martin; Beneš, Milan J.

    2005-01-01

    Roč. 59, - (2005), s. 267-274 ISSN 0926-3373 R&D Projects: GA AV ČR IBS5020306; GA ČR GA203/01/0944 Institutional research plan: CEZ:AV0Z7090911 Keywords : degradation * polycyclic aromatic hydrocarbon * hydrogen peroxide Subject RIV: EE - Microbiology, Virology Impact factor: 3.809, year: 2005

  19. Variability of Biological Degradation of Aromatic Hydrocarbons in an Aerobic Aquifer Determined by Laboratory Batch Experiments

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Christensen, Thomas Højlund

    1994-01-01

    The biological aerobic degradation of 7 aromatic hydrocarbons (benzene, toluene, o-xylene, p-dichlorobenzene, o-dichlorobenzene, naphthalene and biphenyl) was studied for 149 days in replicate laboratory batch experiments with groundwater and sediment from 8 localities representing a 15 m × 30 m...

  20. The NASA Ames Polycyclic Aromatic Hydrocarbon Infrared Spectroscopic Database : The Computed Spectra

    NARCIS (Netherlands)

    Bauschlicher, C. W.; Boersma, C.; Ricca, A.; Mattioda, A. L.; Cami, J.; Peeters, E.; de Armas, F. Sanchez; Saborido, G. Puerta; Hudgins, D. M.; Allamandola, L. J.

    The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant

  1. Polycyclic aromatic hydrocarbon migration from creosote-treated railway ties into ballast and adjacent wetlands

    Science.gov (United States)

    Kenneth M. Brooks

    2004-01-01

    Occasionally, creosote-treated railroad ties need to be replaced, sometimes in sensitive environments such as wetlands. To help determine if this is detrimental to the surrounding environment, more information is needed on the extent and pattern of creosote, or more specifically polycyclic aromatic hydrocarbon (PAH), migration from railroad ties and what effects this...

  2. Removal of crude oil polycyclic aromatic hydrocarbons via organoclay-microbe-oil interactions.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Fialips, Claire I

    2017-05-01

    Clay minerals are quite vital in biogeochemical processes but the effect of organo-clays in the microbial degradation of crude oil polycyclic aromatic hydrocarbons is not well understood. The role of organo-saponite and organo-montmorillonite in comparison with the unmodified clays in crude oil polycyclic aromatic hydrocarbons (PAHs) removal via adsorption and biodegradation was studied by carrying out microcosm experiments in aqueous clay/oil systems with a hydrocarbon degrading microbial community that is predominantly alcanivorax spp. Montmorillonite and saponite samples were treated with didecyldimethylammonium bromide to produce organo-montmorillonite and organo-saponite used in this study. Obtained results indicate that clays with high cation exchange capacity (CEC) such as montmorillonite produced organo-clay (organomontmorillonite) that was not stimulatory to biodegradation of crude oil polycyclic aromatic compounds, especially the low molecular weight (LMW) ones, such as dimethylnaphthalenes. It is suggested that interaction between the organic phase of the organo-clay and the crude oil PAHs which is hydrophobic in nature must have reduced the availability of the polycyclic aromatic hydrocarbons for biodegradation. Organo-saponite did not enhance the microbial degradation of dimethylnaphthalenes but enhanced the biodegradation of some other PAHs such as phenanthrene. The unmodified montmorillonite enhanced the microbial degradation of the PAHs and is most likely to have done so as a result of its high surface area that allows the accumulation of microbes and nutrients enhancing their contact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Trapping of polycyclic aromatic hydrocarbons by amphiphilic cyclodextrin functionalized polypropylene nonwovens

    DEFF Research Database (Denmark)

    Lumholdt, Ludmilla; Nielsen, Ronnie Bo Højstrup; Larsen, Kim Lambertsen

    of the textile fibers. In this study we present the ability of amphiphilic CD coated polypropylene nonwovens to trap 8 different polycyclic aromatic hydrocarbons/endocrine disruptors from aqueous solutions thus demonstrating the potential of using the amphiphilic cyclodextrins for water purification....

  4. Graphene etching on SiC grains as a path to interstellar polycyclic aromatic hydrocarbons formation.

    Science.gov (United States)

    Merino, P; Švec, M; Martinez, J I; Jelinek, P; Lacovig, P; Dalmiglio, M; Lizzit, S; Soukiassian, P; Cernicharo, J; Martin-Gago, J A

    2014-01-01

    Polycyclic aromatic hydrocarbons as well as other organic molecules appear among the most abundant observed species in interstellar space and are key molecules to understanding the prebiotic roots of life. However, their existence and abundance in space remain a puzzle. Here we present a new top-down route to form polycyclic aromatic hydrocarbons in large quantities in space. We show that aromatic species can be efficiently formed on the graphitized surface of the abundant silicon carbide stardust on exposure to atomic hydrogen under pressure and temperature conditions analogous to those of the interstellar medium. To this aim, we mimic the circumstellar environment using ultra-high vacuum chambers and investigate the SiC surface by in situ advanced characterization techniques combined with first-principles molecular dynamics calculations. These results suggest that top-down routes are crucial to astrochemistry to explain the abundance of organic species and to uncover the origin of unidentified infrared emission features from advanced observations.

  5. A field experiment for the anaerobic biotransformation of aromatic hydrocarbon compounds at Seal Beach, California

    International Nuclear Information System (INIS)

    Reinhard, M.; Wills, L.E.; Ball, H.A.; Harmon, T.

    1991-01-01

    Biotransformation of aromatic hydrocarbons under anaerobic conditions is of interest because dissolved oxygen is rapidly consumed in groundwater contaminant plumes of hydrocarbon fuel. Anaerobic biotransformation of aromatic hydrocarbons has been demonstrated under different redox regimes including nitrate-reducing iron-reducing and fermentative-methanogenic conditions. Recently, laboratory evidence has been obtained for the degradation of alkylbenzenes including toluene under sulfate-reducing conditions. The long-term objective of this study is to determine transformation rates under the conditions of the Seal Beach site, and second to explore the feasibility of inducing nitrate- and sulfate-reducing conditions and fermentative-methanogenic conditions in field bioreactors. Both laboratory studies and field studies in bioreactors are being conducted. This paper reports on the experimental design of the bioreactors and initial results

  6. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part A-Monocyclic and Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-08-01

    Present study focused on the screening of bacterial consortium for biodegradation of monocyclic aromatic hydrocarbon (MAH) and polycyclic aromatic hydrocarbons (PAHs). Target compounds in the present study were naphthalene, acenaphthene, phenanthrene (PAHs), and benzene (MAH). Microbial consortia enriched with the above target compounds were used in screening experiments. Naphthalene-enriched consortium was found to be the most efficient consortium, based on its substrate degradation rate and its ability to degrade other aromatic pollutants with significantly high efficiency. Substrate degradation rate with naphthalene-enriched culture followed the order benzene > naphthalene > acenaphthene > phenanthrene. Chryseobacterium and Rhodobacter were discerned as the predominant species in naphthalene-enriched culture. They are closely associated to the type strain Chryseobacterium arthrosphaerae and Rhodobacter maris, respectively. Single substrate biodegradation studies with naphthalene (PAH) and benzene (MAH) were carried out using naphthalene-enriched microbial consortium (NAPH). Phenol and 2-hydroxybenzaldehyde were identified as the predominant intermediates during benzene and naphthalene degradation, respectively. Biodegradation of toluene, ethyl benzene, xylene, phenol, and indole by NAPH was also investigated. Monod inhibition model was able to simulate biodegradation kinetics for benzene, whereas multiple substrate biodegradation model was able to simulate biodegradation kinetics for naphthalene.

  7. Stimulated anoxic biodegradation of aromatic hydrocarbons using Fe(III) ligands

    Science.gov (United States)

    Lovley, D.R.; Woodward, J.C.; Chapelle, F.H.

    1994-01-01

    Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive. Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access. Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in the presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing the bioavailability of Fe(III) by adding suitable ligands provides a potential alternative to oxygen addition for the bioremediation of petroleum-contaminated aquifers.Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive. Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access. Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in the presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing

  8. Novel production methods for ethylene, light hydrocarbons, and aromatics

    International Nuclear Information System (INIS)

    Albright, L.F.; Crynes, B.L.; Nowak, S.

    1992-01-01

    This book covers the following topics: catalytic production of ethylene; oxidative coupling of methane over Sm 2 O 3 ; balancing heat flow in natural gas conversion; olefin production; methanol/hydrocarbon cracking; flash pyrolysis and methanolysis of biomass for production of ethylene, benzene, and methanol

  9. Potential for biodegradation of polycyclic aromatic hydrocarbons by ...

    African Journals Online (AJOL)

    WiTT

    2012-05-08

    May 8, 2012 ... model revealed that N. hatei was the best microorganism in the biodegradation of used motor oil with ... leakage of fuel into the motor oil as well as the ..... Afr. J. Biotechnol. 7(12): 1927-1932. Tanecredi JT (1977). Petroleum hydrocarbons from effluents: detection in marine environment. J. Water Pollut.

  10. Degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria

    NARCIS (Netherlands)

    Weelink, S.A.B.

    2008-01-01

    Accidental spills, industrial discharges and gasoline leakage from underground storage tanks have resulted in serious pollution of the environment with monoaromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX). High concentrations of BTEX have been detected in

  11. Determination of levels of polycyclic aromatic hydrocarbons in soil ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: Soil samples contaminated with spent motor engine oil collected from Abakaliki auto-mechanic site were ... Waste oil is a mixture of different chemicals including petroleum hydrocarbons, chlorinated biphenyls, chlorodibenzofurans, additives, decomposition products and heavy metals that come from engine.

  12. Growth of fungi on volatile aromatic hydrocarbons: environmental technology perspectives

    NARCIS (Netherlands)

    Prenafeta Boldú, F.X.

    2002-01-01

    The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching

  13. Aromatic Hydrocarbons: Degrading Bacteria in the Desert Soil of Kuwait

    International Nuclear Information System (INIS)

    Al-Gounaim, M.; Diab, A.; Al-Hilali, A.; Abu-Shady, A. Sattar

    2005-01-01

    Soil samples of different levels of oil pollutants were collected from Kuwait's Burgan Oil Field, near an oil lake. The samples represented, highly polluted (8.0% w/w), moderately polluted (2.1%-3.4%) and slightly polluted (2.1%-3.4%) and slightly polluted (0.5- 0.8%). The aromatic fractions of the collected samples were in the range of (0.21-2.57g/100g) soil. (GC) analysis of the aromatic fractions of the resolution of the different individual (PAHs) revealed the presence of (16) different (PAHs) resolved from the aromatic fraction of the highly polluted sample (S3). (15), (14) and (13) individual (PAHs) were identified soil samples (S5), (S2) and (S1, S4, S6) respectively. The most frequent (PAH) was indeno (1, 2, 3-c, d) pyrene (22.5%-45.11%) followed chrysene (13.6%-19.48%). Eight carcinogenic (PAHs) were resolved from the aromatic fractions of the polluted samples. Total carcinogenic (PAHs) recorded in this study were in this study were in the range of (11.53) (forS4) - (510.98) (for S3) ppm. The counts of (CFU) of aromatic degraders (AD) were in the range of (3x10) - (110x 10) (CFU/g) soil (with a percent of (2.2%-69.6%)). The results show that, higher counts of (AD) were recorded from a highly polluted sample (S3), followed by the moderately polluted samples; total of (51) bacteria, that gave presumptive positive biodegradation activities, were isolated and identified (45.1%) of them were isolated and identified. (45.1%) of them were isolated from the highly polluted sample (S3). Total of (13) different species were identified of which Micrococcus luteus was more frequent (23.5) followed by Bacillus licheniformis (19.6%) and Bacillus subtilis (11.8%). The three Pseudomonas species collectively were presented by (11.8%). Five different species proved to be of good activities, they are: Bacillus brevis, Bacillus lichenoformis, Pseudomonas aeruginosa, Pseudomonas stutzeri and Pseudomonas flourescens. The ability of five species and their mixture was

  14. Polycyclic aromatic hydrocarbons and molecular hydrogen in oxygen-rich planetary nebulae: the case of NGC 6720.

    Science.gov (United States)

    Cox, N L J; Pilleri, P; Berné, O; Cernicharo, J; Joblin, C

    2016-02-11

    Evolved stars are primary sources for the formation of polycyclic aromatic hydrocarbons (PAHs) and dust grains. Their circumstellar chemistry is usually designated as either oxygen-rich or carbon-rich, although dual-dust chemistry objects, whose infrared spectra reveal both silicate- and carbon-dust features, are also known. The exact origin and nature of this dual-dust chemistry is not yet understood. Spitzer -IRS mid-infrared spectroscopic imaging of the nearby, oxygen-rich planetary nebula NGC 6720 reveals the presence of the 11.3 μ m aromatic (PAH) emission band. It is attributed to emission from neutral PAHs, since no band is observed in the 7-8 μ m range. The spatial distribution of PAHs is found to closely follow that of the warm clumpy molecular hydrogen emission. Emission from both neutral PAHs and warm H 2 is likely to arise from photo-dissociation regions associated with dense knots that are located within the main ring. The presence of PAHs together with the previously derived high abundance of free carbon (relative to CO) suggest that the local conditions in an oxygen-rich environment can also become conducive to in-situ formation of large carbonaceous molecules, such as PAHs, via a bottom-up chemical pathway. In this scenario, the same stellar source can enrich the interstellar medium with both oxygen-rich dust and large carbonaceous molecules.

  15. PcMtr, an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum

    NARCIS (Netherlands)

    Trip, H; Evers, ME; Driessen, AJM

    2004-01-01

    The gene encoding an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum was cloned, functionally expressed and characterized in Saccharomyces cerevisiae M4276. The permease, designated PcMtr, is structurally and functionally homologous to Mtr of Neurospora crassa, and

  16. Adsorption of polar aromatic hydrocarbons on synthetic calcite

    DEFF Research Database (Denmark)

    Madsen, Lene; Grahl-Madsen, Laila; Grøn, Christian

    1996-01-01

    The wettability of hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. A model system of synthetic call cite, cyclohexane and the three probe molecules: benzoic acid, benzyl alcohol and benzylamine, have been...... of magnitude of Delta G degrees for the adsorption process implies the formation of a strong bond between the calcite surface and the adsorbate molecules. Copyright (C) 1996 Elsevier Science Ltd....

  17. Estrogenic Activity of Mineral Oil Aromatic Hydrocarbons Used in Printing Inks.

    Directory of Open Access Journals (Sweden)

    Patrick Tarnow

    Full Text Available The majority of printing inks are based on mineral oils (MOs which contain complex mixtures of saturated and aromatic hydrocarbons. Consumer exposure to these oils occurs either through direct skin contacts or, more frequently, as a result of MO migration into the contents of food packaging that was made from recycled newspaper. Despite this ubiquitous and frequent exposure little is known about the potential toxicological effects, particularly with regard to the aromatic MO fractions. From a toxicological point of view the huge amount of alkylated and unsubstituted compounds therein is reason for concern as they can harbor genotoxicants as well as potential endocrine disruptors. The aim of this study was to assess both the genotoxic and estrogenic potential of MOs used in printing inks. Mineral oils with various aromatic hydrocarbon contents were tested using a battery of in vitro assays selected to address various endpoints such as estrogen-dependent cell proliferation, activation of estrogen receptor α or transcriptional induction of estrogenic target genes. In addition, the comet assay has been applied to test for genotoxicity. Out of 15 MOs tested, 10 were found to potentially act as xenoestrogens. For most of the oils the effects were clearly triggered by constituents of the aromatic hydrocarbon fraction. From 5 oils tested in the comet assay, 2 showed slight genotoxicity. Altogether it appears that MOs used in printing inks are potential endocrine disruptors and should thus be assessed carefully to what extent they might contribute to the total estrogenic burden in humans.

  18. Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons.

    Science.gov (United States)

    Gonul, L Tolga; Kucuksezgin, Filiz

    2012-01-01

    Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern Mediterranean in 2008. Total aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g(-1) dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g(-1) dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged from a relatively low to a moderate PAHs pollution compared to other urbanized coastal areas worldwide. PAH consisted mainly of pyrolytic four- to five-ring compounds. Both pyrolytic and petrogenic PAHs are present in most samples, although petroleum-derived PAH are dominant at Izmir Inner Bay (IIB) and Dardanelles Strait, and pyrolytic sources are prevalent in other sampling sites. A high contribution of perylene, a diagenetic originated PAH, to the total penta PAHs was found greater than 70% in Meric River Estuary, Dikili Bay, Candarli Bay, and Gokova Bay sites. The spatial distributions of aliphatic hydrocarbons and PAHs indicated that urban runoff and transport from the continental shelf is the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near-shore area. PAH levels at all sites were below the effects range-low (ERL) and effects range-median (ERM) values except fluorene. The average and maximum fluorene concentrations exceeded ERL, but below ERM, in the IIB. Meanwhile, the concentration levels of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene, and chrysene were higher than threshold effect level values at the same site, but all these compounds were significantly lower than the probable effect level values. The results indicated that the sediments should have potential biological impact.

  19. The use of polynuclear aromatic hydrocarbon (PAH) alkyl homologues in determining petroleum source identification and weathering

    International Nuclear Information System (INIS)

    Brown, J.S.; Boehm, P.D.; Sauer, T.C.; Wong, W.M.C.

    1993-01-01

    Techniques utilizing double ratio plots of selected polynuclear aromatic hydrocarbon (PAH) alkyl homologues were used to identify and distinguish crude oils and refined petroleum products from each other and to distinguish petroleum sources in complex pollutant regimes. Petroleum samples were fractionated by high performance liquid chromatography (HPLC) into saturated and aromatic (PAH) hydrocarbon fractions. The saturated hydrocarbon fractions were then analyzed by gas chromatography/flame ionization detection (GC/FID) to obtain a resolved/unresolved alkane fingerprint of each oil. The aromatic fractions of the oils were analyzed by gas chromatography/mass spectrometry (GC/MS) for PAH and selected alkyl homologues. Comparisons of the saturated hydrocarbon fingerprints indicated that some oils were indistinguishable based on the alkane fingerprint alone. Another double ratio plot of the alkyl chrysenes and alkyl dibenzothiophenes was effective in establishing the weathering of oil in environmental samples which were processed using the same analytical techniques, since the dibenzothiophenes are degraded more rapidly than the chrysenes. The application of selected ratios in oil spill source identification in complex environmental samples from Suisin Bay California and Boston Harbor are discussed. The use of ratios to measure the extent of weathering in oil spill samples from Prince William Sound and the Gulf of Alaska is examined

  20. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated pesticides in background air in central Europe - investigating parameters affecting wet scavenging of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Shahpoury, P.; Lammel, G.; Holubová Šmejkalová, A.; Klánová, J.; Přibylová, P.; Váňa, M.

    2015-02-01

    Concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and chlorinated pesticides (CPs) were measured in air and precipitation at a background site in central Europe. ∑ PAH concentrations in air and rainwater ranged from 0.7 to 327.9 ng m-3 and below limit of quantification (air ranged from gas-particle partitioning on scavenging process. The particulate matter removal by rain, and consequently PAH wet scavenging, was more effective when the concentrations of ionic species were high. In addition, the elemental and organic carbon contents of the particulate matter were found to influence the PAH scavenging.

  1. Compositional changes of aromatic steroid hydrocarbons in naturally weathered oil residues in the Egyptian western desert

    International Nuclear Information System (INIS)

    Barakat, A.O.; Qian, Y.; Kim, M.; Kennicutt, M.C. II

    2002-01-01

    Aromatic steranes are geochemical markers that can be used to study the maturation of organic matter of sediments and to correlate crude oils and source rocks. In this study, naturally weathered oil residues from an arid waste disposal site in Al-Alamein, Egypt, were analyzed for monoaromatic and triaromatic steranes to show the usefulness of biomarker compounds in assessing changes in chemical composition during the degradation of oil residues that have been released onto terrestrial environments. Gas chromatography and mass spectrometry were used to characterize the individual aromatic compounds. Results indicate that triaromatic sterane distributions are similar in oil residues with varying extents of weathering. The distribution correlated with a fresh crude oil sample from Western Desert-sourced oil. Molecular ratios of triaromatic sterane compounds were found to be suitable for source identification. The major changes in chemical compositions resulting from the weathering of the oil included the depletion of short chain mono- and tri-aromatic steranes in extremely weathered samples. The results of the triaromatic sterane distribution correspond with weathering classifications based on the analyses of saturated and aromatic hydrocarbons and the ratios of n-alkanes, polycyclic aromatic hydrocarbons, and saturate biomarker compounds. 15 refs., 3 tabs., 3 figs

  2. Mechanistic studies on the OH-initiated atmospheric oxidation of selected aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nehr, Sascha

    2012-07-01

    Benzene, toluene, the xylenes, and the trimethylbenzenes are among the most abundant aromatic trace constituents of the atmosphere mainly originating from anthropogenic sources. The OH-initiated atmospheric photo-oxidation of aromatic hydrocarbons is the predominant removal process resulting in the formation of O{sub 3} and secondary organic aerosol. Therefore, aromatics are important trace constituents regarding air pollution in urban environments. Our understanding of aromatic photo-oxidation processes is far from being complete. This work presents novel approaches for the investigation of OH-initiated atmospheric degradation mechanisms of aromatic hydrocarbons. Firstly, pulsed kinetic studies were performed to investigate the prompt HO{sub 2} formation from OH+ aromatic hydrocarbon reactions under ambient conditions. For these studies, the existing OH reactivity instrument, based on the flash photolysis/laser-induced fluorescence (FP/LIF) technique, was extended to the detection of HO{sub 2} radicals. The experimental design allows for the determination of HO{sub 2} formation yields and kinetics. Results of the pulsed kinetic experiments complement previous product studies and help to reduce uncertainties regarding the primary oxidation steps. Secondly, experiments with aromatic hydrocarbons were performed under atmospheric conditions in the outdoor atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber) located at Forschungszentrum Juelich. The experiments were aimed at the evaluation of up-to-date aromatic degradation schemes of the Master Chemical Mechanism (MCMv3.2). The unique combination of analytical instruments operated at SAPHIR allows for a detailed investigation of HO{sub x} and NO{sub x} budgets and for the determination of primary phenolic oxidation product yields. MCMv3.2 deficiencies were identified and most likely originate from shortcomings in the mechanistic representation of ring

  3. Dissolved and Suspended Polycyclic Aromatic Hydrocarbons (PAH) in the North Aegean Sea

    OpenAIRE

    HATZIANESTIS, I.; SKLIVAGOU, E.

    2002-01-01

    The distribution and sources of polycyclic aromatic hydrocarbons (PAH) were investigated in the seawater of the North Aegean Sea. The measured PAH concentrations in SPM are generally considered as elevated for open sea waters and were evenly distributed in the area. Their levels in the dissolved phase (1.6-33.0 ng/l) were much higher than those encountered in the corresponding particulate phases (0.04-10.2 ng/l). The PAH patterns in both phases were dominated by the three ring aromatics and t...

  4. Computational Spectroscopy of Polycyclic Aromatic Hydrocarbons In Support of Laboratory Astrophysics

    Science.gov (United States)

    Tan, Xiaofeng; Salama, Farid

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are strong candidates for the molecular carriers of the unidentified infrared bands (UIR) and the diffuse interstellar bands (DIBs). In order to test the PAH hypothesis, we have systematically measured the vibronic spectra of a number of jet-cooled neutral and ionized PAHs in the near ultraviolet (UV) to visible spectral ranges using the cavity ring-down spectroscopy. To support this experimental effort, we have carried out theoretical studies of the spectra obtained in our measurements. Ab initio and (time-dependent) density.functiona1 theory calculations are performed to obtain the geometries, energetics, vibrational frequencies, transition dipole moments, and normal coordinates of these PAH molecules. Franck-Condon (FC) calculations and/or vibronic calculations are then performed using the calculated normal coordinates and vibrational frequencies to simulate the vibronic spectra. It is found that vibronic interactions in these conjugated pi electron systems are often strong enough to cause significant deviations from the Born-Oppenheimer (BO) approximation. For vibronic transitions that are well described by the BO approximation, the vibronic band profiles are simulated by calculating the rotational structure of the vibronic transitions. Vibronic oscillator strength factors are calculated in the frame of the FC approximation from the electronic transition dipole moments and the FC factors. This computational effort together with our experimental measurements provides, for the first time, powerful tools for comparison with space-based data and, hence, a powerful approach to understand the spectroscopy of interstellar PAH analogs and the nature of the UIR and DIBs.

  5. Spectroscopy of electronic transitions in Polycyclic Aromatic Hydrocarbon cations and their clusters

    International Nuclear Information System (INIS)

    Friha, Hela

    2012-01-01

    This thesis is an experimental study of the electronic spectroscopy of cations of Polycyclic Aromatic Hydrocarbons (PAHs) and their aggregates in conditions close to those of the interstellar medium (ISM), i.e. cold and totally isolated in the gas phase. It is related to the astrophysical context of the interstellar medium (ISM), in particular on the question of the possible link between interstellar PAHs and Diffuse Interstellar Bands (DIBs). The purpose of this thesis is to provide laboratory spectra which can be directly compared to the spectra of DIBs. Indeed these bands are the oldest spectroscopy riddle in astrophysics which remained unanswered for nearly 100 years and whose key is still looked for. A special attention is given to the methylated derivatives of PAHs species detected in many interstellar environments, cationic PAH dimers (the simplest PAH clusters). These clusters have been proposed as a model of the very small grains, which contribute to the formation of interstellar PAHs and whose chemical composition remains uncertain. This thesis has been mainly devoted to the determination of the electronic spectra of naphthalene cation monomer (Np + ) and its methylated derivative (2-MeN p + ), as well as the associated homogeneous dimers. The experimental method used is based on the photodissociation of van der Waals complexes PAH + m -Ar n (argon atoms spectators), prepared by UV laser photoionization in a supersonic jet. This technique combines different experimental tools, namely: molecular beam mass spectrometry and laser spectroscopy as well as physical tools such as the handling of clusters VdW PAH + m -Ar n , the detection of photo-fragments, the measurement of photodissociation efficiency. The identification of the fragments by the photodissociation of VdW clusters allowed us to determine the different possible fragmentation channels and especially to obtain the spectra the charge resonance transition and the first allowed transition to locally

  6. The aryl hydrocarbon receptor-dependent deregulation of cell cycle control induced by polycyclic aromatic hydrocarbons in rat liver epithelial cells

    Czech Academy of Sciences Publication Activity Database

    Andrysík, Zdeněk; Vondráček, Jan; Machala, M.; Krčmář, P.; Šindlerová, Lenka; Kranz, A.; Weiss, C.; Faust, D.; Kozubík, Alois; Dietrich, C.

    2007-01-01

    Roč. 615, č. 1-2 (2007), s. 87-97 ISSN 0027-5107 R&D Projects: GA AV ČR(CZ) KJB6004407 Institutional research plan: CEZ:AV0Z50040702 Keywords : aryl hydrocarbon receptor * contact inhibition * polycyclic aromatic hydrocarbons Subject RIV: BO - Biophysics Impact factor: 4.159, year: 2007

  7. Analysis of aliphatic and aromatic hydrocarbons in particulate matter in Madrid urban area

    International Nuclear Information System (INIS)

    Perez, M.; Mendez, J.; Bomboi, M.T.

    1988-01-01

    Levels of n-alkanes and polycyclic aromatic hydrocarbons have been measured in the air particulate matter during six months, from January to June of 1987, in an urban area of Madrid. The hydrocarbons were collected on glass fiber filters by high volumen sampling. The extraction was carried out by Sohxlet and ultrasonic techniques. The extracts were clean-up on silicagel fractionation and the chromatographic analysis was performed by capillary column gas chromatographic. Final results are discussed as well as the immission values related to the possible emission sources. (Author)

  8. INTERPRETING THE SUBTLE SPECTRAL VARIATIONS OF THE 11.2 AND 12.7 μ m POLYCYCLIC AROMATIC HYDROCARBON BANDS

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, M. J.; Stock, D. J.; Peeters, E., E-mail: mshann3@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada)

    2016-06-20

    We report new properties of the 11 and 12.7 μ m emission complexes of polycyclic aromatic hydrocarbons (PAHs) by applying a Gaussian-based decomposition technique. Using high-resolution Spitzer Space Telescope data, we study in detail the spectral and spatial characteristics of the 11 and 12.7 μ m emission bands in maps of reflection nebulae NGC 7023 and NGC 2023 (north and south) and the star-forming region M17. Profile variations are observed in both the 11 and 12.7 μ m emission bands. We identify a neutral contribution to the traditional 11.0 μ m PAH band and a cationic contribution to the traditional 11.2 μ m band, the latter of which affects the PAH class of the 11.2 μ m emission in our sample. The peak variations of the 12.7 μ m complex are explained by the competition between two underlying blended components. The spatial distributions of these components link them to cations and neutrals. We conclude that the 12.7 μ m emission originates in both neutral and cationic PAHs, lending support to the use of the 12.7/11.2 intensity ratio as a charge proxy.

  9. Polycyclic aromatic hydrocarbons profiles of spent drilling fluids deposited at Emu-Uno, Delta State, Nigeria.

    Science.gov (United States)

    Iwegbue, Chukwujindu M A

    2011-10-01

    The concentrations and profiles of polycyclic aromatic hydrocarbons were determined in spent drilling fluid deposited at Emu-Uno, Delta State of Nigeria. The total concentrations of polycyclic aromatic hydrocarbons in the spent drilling fluid deposits ranged between 40 and 770 μg kg(-1). The PAHs profile were predominantly 2- and 3-rings with acenaphthalene, phenanthrene, fluorene being the predominant PAHs. The prevalence of 2- and 3-rings PAHs in the spent drilling fluid deposits indicate contamination of the drilling fluids with crude oil during drilling. Incorporation of spent drilling fluids into the soil has serious implication for soil, surface water and groundwater quality. © Springer Science+Business Media, LLC 2011

  10. Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

    Science.gov (United States)

    Pogorzelec, Marta; Piekarska, Katarzyna

    2017-11-01

    The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland). To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC). Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

  11. Factors affecting elimination of polycyclic aromatic hydrocarbons from traditional smoked common carp meat

    Science.gov (United States)

    Babić, J.; Vidaković, S.; Škaljac, S.; Kartalović, B.; Ljubojević, D.; Ćirković, M.; Teodorović, V.

    2017-09-01

    Smoking techniques have been progressively improved and different procedures have been developed in different regions for treating fish. In these times, the technology is mainly used for enrichment of fish with specific taste and odour, to extend the shelf-life of these perishable products and appearance required widely on the market. A lot of chemical contaminants such as polycyclic aromatic hydrocarbons (PAHs) are formed during the combustion of fuel in the smoking process. PAHs are a group of compounds that have been the subject of great concern in the recent years due to their toxic, mutagenic and/or carcinogenic potentials to humans. These fact can have a significant impact on the acceptance of these products by consumers. In this review article, the objective is to describe factors affecting elimination of polycyclic aromatic hydrocarbons from traditional smoked common carp meat.

  12. Renal cancer risk and occupational exposure to polycyclic aromatic hydrocarbons and plastics

    Science.gov (United States)

    Karami, Sara; Boffetta, Paolo; Brennan, Paul; Stewart, Patricia A.; Zaridze, David; Matveev, Vsevolod; Janout, Vladimir; Kollarova, Helena; Bencko, Vladimir; Navratilova, Marie; Szeszenia-Dabrowska, Neonila; Mates, Dana; Gromiec, Jan P.; Sobotka, Roman; Chow, Wong-Ho; Rothman, Nathaniel; Moore, Lee E.

    2011-01-01

    Objective To investigate whether occupational exposure to polycyclic aromatic hydrocarbons and certain plastic monomers increased renal cell carcinomas (RCC) risk. Methods Unconditional logistic regression was used to calculate RCC risk in relation to exposure. Results No association between RCC risk and having ever been occupationally exposed to any polycyclic aromatic hydrocarbons or plastics was observed. Duration of exposure and average exposure also showed no association with risk. Suggestive positive associations between RCC risk and cumulative exposure to styrene (P-trend = 0.02) and acrylonitrile (P-trend = 0.06) were found. Cumulative exposure to petroleum/gasoline engine emissions was inversely associated with risk (P-trend = 0.02). Conclusions Results indicate a possible association between occupational styrene and acrylonitrile exposure and RCC risk. Additional studies are needed to replicate findings, as this is the first time these associations have been reported and they may be due to chance. PMID:21270648

  13. Dissolved and Suspended Polycyclic Aromatic Hydrocarbons (PAH in the North Aegean Sea

    Directory of Open Access Journals (Sweden)

    I. HATZIANESTIS

    2002-06-01

    Full Text Available The distribution and sources of polycyclic aromatic hydrocarbons (PAH were investigated in the seawater of the North Aegean Sea. The measured PAH concentrations in SPM are generally considered as elevated for open sea waters and were evenly distributed in the area. Their levels in the dissolved phase (1.6-33.0 ng/l were much higher than those encountered in the corresponding particulate phases (0.04-10.2 ng/l. The PAH patterns in both phases were dominated by the three ring aromatics and their alkylated derivatives, reflecting a predominant contribution of fossil hydrocarbons probably related to ship traffic, whereas no significant inputs from the rivers outfalling in the area were detected. In bottom waters PAH values were generally lower, whereas a higher depletion of the petroleum PAH in comparison with the pyrolytic ones according to depth was observed.

  14. Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (Chelydra serpentina) embryos and hatchlings

    International Nuclear Information System (INIS)

    Van Meter, Robin J.; Spotila, James R.; Avery, Harold W.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic development. Exposure to PAHs had a significant effect on survival rates in embryos from one clean reference site, but not in embryos from the other sites. There was a positive linear relationship between level of exposure to PAHs and severity of deformities in embryos collected from two of the clean reference sites. Neither righting response nor upper temperature tolerance (critical thermal maximum, CTM) of snapping turtle hatchlings with no or minor deformities was significantly affected by exposure to PAHs. - Exposure to polycyclic aromatic hydrocarbons on the egg reduces survival of snapping turtle embryos and causes developmental abnormalities

  15. Avoidance of polycyclic aromatic hydrocarbon-contaminated sediments by the freshwater invertebrates Gammarus pulex and Asellus aquaticus

    NARCIS (Netherlands)

    Lange, de H.J.; Sperber, V.; Peeters, E.T.H.M.

    2006-01-01

    Contamination of sediments is a serious problem in most industrialized areas. Sediments are often contaminated with trace metals and organic contaminants like polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Bioassays are often used to determine the effect of

  16. PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES

    Science.gov (United States)

    The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

  17. The Unusual Hydrocarbon Emission From the Early Carbon Star HD 100764: The Connection Between Aromatics and Aliphatics

    National Research Council Canada - National Science Library

    Sloan, G. C; Jura, M; Duley, W. W; Kraemer, K. E; Bernard-Salas, J; Forrest, W. J; Sargent, B; Li, A; Barry, D. J; Bohac, C. J

    2007-01-01

    .... The spectrum shows emission features from polycyclic aromatic hydrocarbons (PAHs) that are shifted to longer wavelengths than normally seen, a characteristic of "class C" systems in the classification scheme of Peeters et al...

  18. FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR GROWTH TO SOOT -A REVIEW OF CHEMICAL REACTION PATHWAYS. (R824970)

    Science.gov (United States)

    The generation by combustion processes of airborne species of current health concern such as polycyclic aromatic hydrocarbons (PAH) and soot particles necessitates a detailed understanding of chemical reaction pathways responsible for their formation. The present review discus...

  19. Polycyclic Aromatic Hydrocarbons in Fine Particulate Matter Emitted from Burning Kerosene, Liquid Petroleum Gas, and Wood Fuels in Household Cookstoves

    Science.gov (United States)

    This study measured polycyclic aromatic hydrocarbon (PAH) composition in particulate matter emissions from residential cookstoves. A variety of fuel and cookstove combinations were examined, including: (i) liquid petroleum gas (LPG), (ii) kerosene in a wick stove, (iii) wood (10%...

  20. Thyroid hormone binding proteins as novel targets for hydroxylated polyhalogenated aromatic hydrocarbons (PHAHs) : possible implications for toxicity

    NARCIS (Netherlands)

    Lans, M.C.

    1995-01-01

    Some toxic effects caused by polyhalogenated aromatic hydrocarbons (PHAHs) develop through alterations in the reproductive and thyroid hormone regulatory systems, thereby affecting (brain) development, reproduction and behaviour of several species (Stone, 1995, Birnbaum, 1994, for review:

  1. Secondary Aerosol Formation from Oxidation of Aromatics Hydrocarbons by Cl atoms

    Science.gov (United States)

    Cai, X.; Griffin, R.

    2006-12-01

    Aerosol Formation From the Oxidation of Aromatic Hydrocarbons by Chlorine Atmospheric secondary organic aerosol (SOA) affects regional and global air quality. The formation mechanisms of SOA via the oxidation of volatile organic compounds by hydroxyl radicals, ozone, and nitrate radicals have been studied intensively during the last decade. Chlorine atoms (Cl) also have been hypothesized to be effective oxidants in marine and industrially influenced areas. Recent work by the authors has indicated that significant amounts of SOA are formed from the oxidation of monoterpenes by Cl. Aromatic hydrocarbons are important for generation of both SOA and ozone in urban areas because of their large emission rates and high reactivity. The goal of this work was to quantify the SOA formation potentials of two representative aromatic hydrocarbons through laboratory chamber experiments in which oxidation was initiated by Cl. The system constructed for this study includes an experimental chamber, a gas chromatograph for quantification of aromatic mixing ratios, a Scanning Mobility Particle Spectrometer to measure SOA size distributions, a zero air generator, and an illuminating system. The model aromatic hydrocarbons chosen for this study are toluene and m-xylene. Aerosol yields are estimated based on measured aerosol volume concentration, the concentration of consumed hydrocarbon, and estimation of wall loss of the newly formed aerosol. Toluene and m-xylene exhibit similar SOA yields from the oxidation initiated by Cl. The toluene SOA yield from Cl-initiated oxidation, however, depends on the ratio between the mixing ratios of the initial chlorine source and toluene in the chamber. For toluene experiments with higher such ratios, SOA yields vary from 0.05 to 0.079 for generated aerosol ranging from 4.2 to12.0 micrograms per cubic meter. In the lower ratio experiments, SOA yields are from 0.033 to 0.064, corresponding to generated aerosol from 3.0 to 11.0 micrograms per cubic

  2. Vibrational Structure in Magnetic Circular Dichroism Spectra of Polycyclic Aromatic Hydrocarbons

    Czech Academy of Sciences Publication Activity Database

    Kaminský, Jakub; Chalupský, Jakub; Štěpánek, P.; Kříž, Jan; Bouř, Petr

    2017-01-01

    Roč. 121, č. 47 (2017), s. 9064-9073 ISSN 1089-5639 R&D Projects: GA ČR GA15-19143S; GA ČR(CZ) GA16-05935S; GA ČR(CZ) GA16-00270S Institutional support: RVO:61388963 Keywords : magnetic circular dichroism * polycyclic aromatic hydrocarbons * DFT Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.847, year: 2016

  3. Degradation of Polycyclic Aromatic Hydrocarbons by a Newly Discovered Enteric Bacterium, Leclercia adecarboxylata

    OpenAIRE

    Sarma, Priyangshu Manab; Bhattacharya, Dhruva; Krishnan, S.; Lal, Banwari

    2004-01-01

    A bacterial strain, PS4040, capable of degrading polycyclic aromatic hydrocarbons for use as the sole carbon source was isolated from oily-sludge-contaminated soil. The 16S rRNA gene showed 98.8% homology to that of Leclercia adecarboxylata. Comparative molecular typing with the clinical strain of L. adecarboxylata revealed that there were few comigrating and few distinct amplimers among them.

  4. Degradation of Polycyclic Aromatic Hydrocarbons by a Newly Discovered Enteric Bacterium, Leclercia adecarboxylata

    Science.gov (United States)

    Sarma, Priyangshu Manab; Bhattacharya, Dhruva; Krishnan, S.; Lal, Banwari

    2004-01-01

    A bacterial strain, PS4040, capable of degrading polycyclic aromatic hydrocarbons for use as the sole carbon source was isolated from oily-sludge-contaminated soil. The 16S rRNA gene showed 98.8% homology to that of Leclercia adecarboxylata. Comparative molecular typing with the clinical strain of L. adecarboxylata revealed that there were few comigrating and few distinct amplimers among them. PMID:15128584

  5. Study of erythrocytes, hemoglobin levels, and menstrual cycle characteristics of women exposed to aromatic hydrocarbons.

    Science.gov (United States)

    Georgieva, T; Lukanova, A; Panev, T; Popov, T

    1998-09-01

    The impact of occupational hazards on erythrocyte and hemoglobin levels and menstrual cycle characteristics in women exposed to aromatic hydrocarbons was studied. The investigated cohort consisted of 110 women exposed to benzene, toluene, xylene and styrene while working in the transport and storage of petrochemical products (TSPP), the laboratory for the control of aromatic hydrocarbons (LCAH), and rubber and latex (RL) production at the biggest petrochemical plant in Bulgaria, Neftochim. Controls consisted of 45 women from the administrative personnel in the same plant. Questionnaires were administrated to all participants to obtain self-reported demographic data, data on characteristics of the menstrual cycle, and psychosomatic symptoms. Erythrocyte counts (RBC) and hemoglobin (HGB) levels were determined by the semiautomatic hematology analyzer Serono System 190, USA. All subjects had signed an informed consent. The mean RBC counts and HGB levels of the women from the LCAH and TSPP departments were statistically significantly lower than those of the control group. We found statistically significant differences in all exposed groups in comparison with controls when the dose-response relationship was investigated. No statistically significant differences were found in menstrual cycle characteristics (duration of the menstrual cycle, days and quantity of bleeding) between the subjects exposed and the controls in all age groups investigated, but the numbers were too small to allow definite conclusions. The lowering of HGB levels and RBC counts in the investigated women were mainly due to the direct influence of aromatic hydrocarbons in the working environment on hematopoiesis. The studied group was too small to enable us to determine the impact of aromatic hydrocarbons on menstrual cycle characteristics, and the possible combination of these effects.

  6. Oxidative damage by carcinogenic polycyclic aromatic hydrocarbons and organic extracts from urban air particulate matter

    Czech Academy of Sciences Publication Activity Database

    Hanzalová, Kateřina; Rössner ml., Pavel; Šrám, Radim

    2010-01-01

    Roč. 696, č. 2 (2010), s. 114-121 ISSN 1383-5718 R&D Projects: GA MŠk 2B08005; GA MŽP(CZ) SP/1B3/8/08 Institutional research plan: CEZ:AV0Z50390512 Keywords : carcinogenic polycyclic aromatic hydrocarbons * oxidative damage in vitro * extractable organic matter Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.938, year: 2010

  7. Tailoring ZSM-5 Zeolites for the Fast Pyrolysis of Biomass to Aromatic Hydrocarbons

    DEFF Research Database (Denmark)

    Hoff, Thomas C.; Gardner, David W.; Thilakaratne, Rajeeva

    2016-01-01

    The production of aromatic hydrocarbons from cellulose by zeolite-catalyzed fast pyrolysis involves a complex reaction network sensitive to the zeolite structure, crystallinity, elemental composition, porosity, and acidity. The interplay of these parameters under the reaction conditions represents...... a major roadblock that has hampered significant improvement in catalyst design for over a decade. Here, we studied commercial and laboratory-synthesized ZSM-5 zeolites and combined data from 10 complementary characterization techniques in an attempt to identify parameters common to high...

  8. [Determination of aromatic polycyclic hydrocarbons during the installation of bituminous acoustic insulation panels].

    Science.gov (United States)

    Gianello, G; Marrubini, G; La Bua, R; Laurini, C; Bergamaschi, A

    2006-01-01

    Two kinds of bituminous European and Asiatic origin panels, used as acoustic insulators in the production of electrical household appliances have been analysed. The tests, made at 180 degrees C, operation temperature during the assembly phases, have been executed by sampling the smokes released during the thermal treatment, subsequently analysed by GC-MS. The results showed a marked difference between the two samples in the amount of the issued compounds, essentially constituted by alkyl-aromatic hydrocarbons, IPA and Alkyl-IPA.

  9. Differential electron emission from polycyclic aromatic hydrocarbon molecules under fast ion impact

    OpenAIRE

    Biswas, Shubhadeep; Champion, Christophe; Tribedi, Lokesh C.

    2017-01-01

    Interaction between polycyclic aromatic hydrocarbon (PAH) molecule and energetic ion is a subject of interest in different areas of modern physics. Here, we present measurements of energy and angular distributions of absolute double differential electron emission cross section for coronene (C24H12) and fluorene (C13H10) molecules under fast bare oxygen ion impact. For coronene, the?angular distributions?of the low energy electrons are quite different from that of simpler targets like Ne or CH...

  10. Studies on mechanisms of toxicity of polycyclic aromatic hydrocarbons using in vitro models

    Czech Academy of Sciences Publication Activity Database

    Vondráček, Jan; Machala, M.

    2005-01-01

    Roč. 149, č. 1 (2005), s. 11 ISSN 1213-8118. [10. Interdisciplinary Czech and Slovak Toxicological Conference. 14.09.2005-16.09.2005, Olomouc] R&D Projects: GA ČR(CZ) GA525/03/1527; GA AV ČR(CZ) KJB6004407 Institutional research plan: CEZ:AV0Z50040507 Keywords : polycyclic aromatic hydrocarbons * toxicity * intercellular communication Subject RIV: BO - Biophysics

  11. Subgap Two-Photon States in Polycyclic Aromatic Hydrocarbons: Evidence for Strong Electron Correlations

    OpenAIRE

    Aryanpour, K.; Roberts, A.; Sandhu, A.; Rathore, R.; Shukla, A.; Mazumdar, S.

    2013-01-01

    Strong electron correlation effects in the photophysics of quasi-one-dimensional $\\pi$-conjugated organic systems such as polyenes, polyacetylenes, polydiacetylenes, etc., have been extensively studied. Far less is known on correlation effects in two-dimensional $\\pi$-conjugated systems. Here we present theoretical and experimental evidence for moderate repulsive electron-electron interactions in a number of finite polycyclic aromatic hydrocarbon molecules with $D_{6h}$ symmetry. We show that...

  12. Hydrogenation of polycyclic aromatic hydrocarbons as a factor affecting the cosmic 6.2 micron emission band

    Science.gov (United States)

    Beegle, L. W.; Wdowiak, T. J.; Harrison, J. G.

    2001-01-01

    While many of the characteristics of the cosmic unidentified infrared (UIR) emission bands observed for interstellar and circumstellar sources within the Milky Way and other galaxies, can be best attributed to vibrational modes of the variants of the molecular family known as polycyclic aromatic hydrocarbons (PAH), there are open questions that need to be resolved. Among them is the observed strength of the 6.2 micron (1600 cm(-1)) band relative to other strong bands, and the generally low strength for measurements in the laboratory of the 1600 cm(-1) skeletal vibration band of many specific neutral PAH molecules. Also, experiments involving laser excitation of some gas phase neutral PAH species while producing long lifetime state emission in the 3.3 micron (3000 cm(-1)) spectral region, do not result in significant 6.2 micron (1600 cm(-1)) emission. A potentially important variant of the neutral PAH species, namely hydrogenated-PAH (H(N)-PAH) which exhibit intriguing spectral correlation with interstellar and circumstellar infrared emission and the 2175 A extinction feature, may be a factor affecting the strength of 6.2 micron emission. These species are hybrids of aromatic and cycloalkane structures. Laboratory infrared absorption spectroscopy augmented by density function theory (DFT) computations of selected partially hydrogenated-PAH molecules, demonstrates enhanced 6.2 micron (1600 cm(-1)) region skeletal vibration mode strength for these molecules relative to the normal PAH form. This along with other factors such as ionization or the incorporation of nitrogen or oxygen atoms could be a reason for the strength of the cosmic 6.2 micron (1600 cm(-1)) feature.

  13. Geochemical markers and polycyclic aromatic hydrocarbons in solvent extracts from diesel engine particulate matter.

    Science.gov (United States)

    Fabiańska, Monika; Kozielska, Barbara; Bielaczyc, Piotr; Woodburn, Joseph; Konieczyński, Jan

    2016-04-01

    Exhaust particulate from compression ignition (CI) engines running on engine and chassis dynamometers was studied. Particulate dichloromethane extracts were qualitatively and quantitatively analyzed for polycyclic aromatic hydrocarbons (PAHs) and biomarkers by gas chromatography with flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). PAH group profiles were made and the PAH group shares according to the number of rings (2 or 3; 4; 5 or more) as well as diagnostic indices were calculated. Values of geochemical ratios of selected biomarkers and alkyl aromatic hydrocarbons were compared with literature values. A geochemical interpretation was carried out using these values and biomarker and alkyl aromatic hydrocarbon distributions. It has been shown that geochemical features are unequivocally connected to the emission of fossil fuels and biofuels burned in CI engines. The effect of the exothermic combustion process is limited to low-molecular-weight compounds, which shows that the applied methodology permits source identification of PAHs coexisting in the particulate emitted.

  14. Soil sealing degree as factor influencing urban soil contamination with polycyclic aromatic hydrocarbons (PAHs

    Directory of Open Access Journals (Sweden)

    Mendyk Łukasz

    2016-03-01

    Full Text Available The objective of the study was to determine role of soil sealing degree as the factor influencing soil contamination with polycyclic aromatic hydrocarbons (PAHs. The study area included four sampling sites located within the administrative boundaries of the Toruń city, Poland. Sampling procedure involved preparing soil pits representing three examples of soil sealing at each site: non-sealed soil as a control one (I and two degrees of soil sealing: semi-pervious surface (II and totally impervious surface (III. Together with basic properties defined with standard procedures (particle size distribution, pH, LOI, content of carbonates content of selected PAHs was determined by dichloromethane extraction using gas chromatography with mass spectrometric detection (GC-MS. Obtained results show that urban soils in the city of Toruń are contaminated with polycyclic aromatic hydrocarbons. Soil sealing degree has a strong influence on the soil contamination with polycyclic aromatic hydrocarbons. Totally sealed soils are better preserved from atmospheric pollution including PAHs. Combustion of grass/wood/coal was the main source of determined PAHs content in examined soils.

  15. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    Energy Technology Data Exchange (ETDEWEB)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy); Zonca, Alberto, E-mail: gmulas@oa-cagliari.inaf.it, E-mail: silvia@oa-cagliari.inaf.it, E-mail: ccp@oa-cagliari.inaf.it, E-mail: azonca@oa-cagliari.inaf.it [Dipartimento di Fisica, Universita di Cagliari, Strada Prov.le Monserrato-Sestu Km 0.700, I-09042 Monserrato (Italy)

    2013-07-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  16. Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

    International Nuclear Information System (INIS)

    Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

    2006-01-01

    Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

  17. Optimizing catalysis conditions to decrease aromatic hydrocarbons and increase alkanes for improving jet biofuel quality.

    Science.gov (United States)

    Cheng, Jun; Li, Tao; Huang, Rui; Zhou, Junhu; Cen, Kefa

    2014-04-01

    To produce quality jet biofuel with high amount of alkanes and low amount of aromatic hydrocarbons, two zeolites of HY and HZSM-5 supporting Ni and Mo were used as catalysts to convert soybean oil into jet fuel. Zeolite HY exhibited higher jet range alkane selectivity (40.3%) and lower jet range aromatic hydrocarbon selectivity (23.8%) than zeolite HZSM-5 (13.8% and 58.9%). When reaction temperature increased from 330 to 390°C, yield of jet fuel over Ni-Mo/HY catalyst at 4 MPa hydrogen pressure increased from 0% to 49.1% due to the shift of reaction pathway from oligomerization to cracking reaction. Further increase of reaction temperature from 390 to 410°C resulted in increased yield of jet range aromatic hydrocarbons from 18.7% to 30%, which decreased jet fuel quality. A high yield of jet fuel (48.2%) was obtained at 1 MPa low hydrogen pressure over Ni (8 wt.%)-Mo (12 wt.%)/HY catalyst. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Stereospecific Winding of Polycyclic Aromatic Hydrocarbons into Trinacria Propellers.

    Science.gov (United States)

    Mosca, Dario; Stopin, Antoine; Wouters, Johan; Demitri, Nicola; Bonifazi, Davide

    2017-11-02

    The stereospecific trimerization of enantiomerically pure binaphthols with hexakis(bromomethyl)benzene gives access in one step to enantiomerically pure molecular propellers, in which three binaphthyl rings are held together with dioxecine rings. X-ray diffraction analysis revealed that three out the six naphthyl moieties are folded in a (EF) 3 -type arrangement held by three intramolecular C-H⋅⋅⋅π interactions. This slips outward the three remaining naphthyl rings in a blade-like fashion, just like in three-folded propeller components. This peculiar conformation shows striking similarity to the mythological Sicilian symbol of Trinacria, from which the name "trinacria propeller" derives. The propeller conformation is also preserved in chlorinated solutions, as displayed by the presence of a peak at 4.7 ppm typical of an aromatic proton resonance engaged in a C-H⋅⋅⋅π interaction. The denaturation of the propeller-like conformation is obtained at high temperature, corresponding to activation energy for the ring inversion of ca. 18.2 kcal mol -1 . Notably, halide-functionalized molecular propellers exposing I-atoms at the leading and trailing edges could be prepared stereo- and regiospecifically by choosing the relevant iodo-bearing BINOL derivative. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Deuterium enrichment of polycyclic aromatic hydrocarbons by photochemically induced exchange with deuterium-rich cosmic ices

    Science.gov (United States)

    Sandford, S. A.; Bernstein, M. P.; Allamandola, L. J.; Gillette, J. S.; Zare, R. N.

    2000-01-01

    The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly exchanges its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. Exchange occurs via three different chemical processes: D atom addition, D atom exchange at oxidized edge sites, and D atom exchange at aromatic edge sites. Observed exchange rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These exchange mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.

  20. The toxicity of photomodified polycyclic aromatic hydrocarbons to Japanese medaka (Oryzias latipes) embryos

    Energy Technology Data Exchange (ETDEWEB)

    Farwell, A.J.; Croft, M.; Rhodes, S.M.; Dixon, D.G. [Waterloo Univ., ON (Canada). Dept. of Biology

    2003-07-01

    Alkylated polycyclic aromatic hydrocarbons (PAHs) occur naturally in process-affected waters associated with bitumen extraction from the Athabasca oil sands in northern Alberta. The hydrocarbon fraction of process-affected water increases the frequency and severity of blue sac disease in Japanese medaka. It also reduces the larval fork length. The United States Environmental Protection Agency has determined that the most common hydrocarbon fraction of the priority pollutants is C2-substituted dibenzothiophenes. This extract was exposed to simulated solar radiation (SSR) to determine the effects of photomodification on its toxicity. Japanese medaka embryos exposed to SSR extracts for 1 and 4 days showed decreased toxicity compared to non-photomodified extracts. Four-day exposures did not reveal any significant changes in hatch length or blue sac disease symptoms, but there was a slight increase in time to hatch.

  1. Combined effects of prenatal polycyclic aromatic hydrocarbons and material hardship on child IQ.

    Science.gov (United States)

    Vishnevetsky, Julia; Tang, Deliang; Chang, Hsin-Wen; Roen, Emily L; Wang, Ya; Rauh, Virginia; Wang, Shuang; Miller, Rachel L; Herbstman, Julie; Perera, Frederica P

    2015-01-01

    Polycyclic aromatic hydrocarbons are common carcinogenic and neurotoxic urban air pollutants. Toxic exposures, including air pollution, are disproportionately high in communities of color and frequently co-occur with chronic economic deprivation. We examined whether the association between child IQ and prenatal exposure to polycyclic aromatic hydrocarbons differed between groups of children whose mothers reported high vs. low material hardship during their pregnancy and through child age 5. We tested statistical interactions between hardships and polycyclic aromatic hydrocarbons, as measured by DNA adducts in cord blood, to determine whether material hardship exacerbated the association between adducts and IQ scores. Prospective cohort. Participants were recruited from 1998 to 2006 and followed from gestation through age 7 years. Urban community (New York City) A community-based sample of 276 minority urban youth EXPOSURE MEASURE: Polycyclic aromatic hydrocarbon-DNA adducts in cord blood as an individual biomarker of prenatal polycyclic aromatic hydrocarbon exposure. Maternal material hardship self-reported prenatally and at multiple timepoints through early childhood. Child IQ at 7 years assessed using the Wechsler Intelligence Scale for Children. Significant inverse effects of high cord PAH-DNA adducts on full scale IQ, perceptual reasoning and working memory scores were observed in the groups whose mothers reported a high level of material hardship during pregnancy or recurring high hardship into the child's early years, and not in those without reported high hardship. Significant interactions were observed between high cord adducts and prenatal hardship on working memory scores (β = -8.07, 95% CI (-14.48, -1.66)) and between high cord adducts and recurrent material hardship (β = -9.82, 95% CI (-16.22, -3.42)). The findings add to other evidence that socioeconomic disadvantage can increase the adverse effects of toxic physical "stressors" like air pollutants

  2. Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polycyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion

    Science.gov (United States)

    Landera, Alexander

    2013-12-01

    Several different mechanisms leading to the formation of (substituted) naphthalene and azanaphthalenes were examined using theoretical quantum chemical calculations. As a result, a series of novel synthetic routes to Polycyclic Aromatic Hydrocarbons (PAHs) and Nitrogen Containing Polycyclic Aromatic Compounds (N-PACs) have been proposed. On Earth, these aromatic compounds originate from incomplete combustion and are released into our environment, where they are known to be major pollutants, often with carcinogenic properties. In the atmosphere of a Saturn's moon Titan, these PAH and N-PACs are believed to play a critical role in organic haze formation, as well as acting as chemical precursors to biologically relevant molecules. The theoretical calculations were performed by employing the ab initio G3(MP2,CC)/B3LYP/6-311G** method to effectively probe the Potential Energy Surfaces (PES) relevant to the PAH and N-PAC formation. Following the construction of the PES, Rice-Ramsperger-Kassel-Markus (RRKM) theory was used to evaluate all unimolecular rate constants as a function of collision energy under single-collision conditions. Branching ratios were then evaluated by solving phenomenological rate expressions for the various product concentrations. The most viable pathways to PAH and N-PAC formation were found to be those where the initial attack by the ethynyl (C2H) or cyano (CN) radical toward a unsaturated hydrocarbon molecule led to the formation of an intermediate which could not effectively lose a hydrogen atom. It is not until ring cyclization has occurred, that hydrogen elimination leads to a closed shell product. By quenching the possibility of the initial hydrogen atom elimination, one of the most competitive processes preventing the PAH or N-PAC formation was avoided, and the PAH or N-PAC formation was allowed to proceed. It is concluded that these considerations should be taken into account when attempting to explore any other potential routes towards

  3. Aliphatic and polycyclic aromatic hydrocarbons in sediments of Kaohsiung Harbour and Adjacent Coast, Taiwan.

    Science.gov (United States)

    Lee, Chon-Lin; Hsieh, Ming-Tsuen; Fang, Meng-Der

    2005-01-01

    Surficial sediment samples collected from Kaohsiung Harbour and its nearby coast were analyzed for aliphatic hydrocarbons and parent polycyclic aromatic hydrocarbons (PAHs). According to our results, the average total concentrations of n-alkanes (n-C12 to C35) and aromatics (15 PAHs) were 4.33 microg g(-1) dry weight (ranged 0.46-22.60) and 0.59 microg g(-1) dry weight (ranged 0.09-1.75), respectively. The highest concentrations of aliphatic and aromatic hydrocarbons were recorded in stations near the estuaries of Qianzhen River and Love River, respectively. Aliphatic hydrocarbons in the samples indicate that there has been significant non-petrogenic, possibly terrestrial, contribution in the sediment of the open coast of Kaohsiung Harbour and that there has been dominant contribution from petrogenic sources in the sediment of the inner harbour. PAHs, detected in the samples, however, indicated a higher pyrolytic contribution in open-coast samples and a higher petrogenic contribution in the inner harbour. Overall, sediment concentrations of total alkanes in this study were comparable to those found in Victoria Harbour, Hong Kong and are higher than those found in Xiamen Harbour, China. Concentrations of total PAHs in inner Kaohsiung Harbour sediments were relatively lower than those found in Victoria Harbour, Hong Kong and Xiamen Harbour, China, but comparable to those found in Hsin-ta Harbour, Taiwan and Incheon Harbour, Korea. In comparison with several effect-based sediment quality guidelines, most PAH concentrations found in samples taken from inner harbour stations exceeded the Threshold Effect Level of Florida indicating a slight possibility of adverse effects.

  4. Application of the cubic-plus-association (CPA) equation of state to complex mixtures with aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2006-01-01

    The cubic-plus-association (CPA) equation of state is applied to phase equilibria of mixtures containing alcohols, glycols, water, and aromatic or olefinic hydrocarbons. Previously, CPA has been successfully used for mixtures containing various associating compounds (alcohols, glycols, amines...... of the model (the Soave-Redlich-Kwong (SRK) equation of state) can be obtained from mixtures with aliphatic hydrocarbons. For mixtures of glycols with aromatic hydrocarbons, two parameters have been fitted to experimental data, one in the physical (SRK) part and one in the association part of the model...

  5. Bioavailability assessment and environmental fate of polycyclic aromatic hydrocarbons in biostimulated creosote-contaminated soil.

    Science.gov (United States)

    Sabaté, Jordi; Viñas, Marc; Solanas, Anna M

    2006-06-01

    When hydrocarbon-contaminated soil is subjected to bioremediation technology, hydrocarbon depletion is typically marked by an initially rapid reduction rate. This rate decreases over time and frequently a residual concentration remains in the soil. This kinetic has been attributed primarily to the enrichment of more recalcitrant fractions, as well as to the lack of resting hydrocarbon bioavailability. Thus, at the end of the bioremediation process, a part of the residual hydrocarbon soil concentration represents the non-bioavailable fraction, which is difficult to degrade by microbial populations and which poses a minor hazard. Therefore, determination of the bioavailable fraction in a bioremediation project represents both an estimation of the maximum level of achievable biodegradation, as well as an additional indication of the environmental health hazard. In the present study, aged creosote-contaminated soil was subjected to biostimulation processes, and the bioavailable fraction for several target polycyclic aromatic hydrocarbons (PAHs) was calculated using a mild extraction with cyclodextrines. The amount of PAH extracted corresponded to the desorbing fraction and can be regarded as the bioavailable fraction. The non-desorbing fraction data obtained from this procedure were compared to the remaining PAH concentrations following bioremediation treatment of soil microcosms. These results permitted the establishment of a theoretical biodegradation limit based on the desorbing fraction. In addition, neither accumulation of intermediate metabolites, nor the formation of bound-residues or reduced acute toxicity was observed.

  6. Biodegradation Of Polycyclic Aromatic Hydrocarbons In Petroleum Oil Contaminating The Environment

    International Nuclear Information System (INIS)

    Partila, A.M.

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in urban atmospheres (Chen et al., 2013). PAHs enter the environment via incomplete combustion of fossil fuels and accidental leakage of petroleum products, and as components of products such as creosote (Muckian et al., 2009). Due to PAHs carcinogenic activity, they have been included in the European Union (EU) and the Environmental Protection Agency (EPA) priority pollutant lists. Human exposure to PAHs occurs in three ways, inhalation, dermal contact and consumption of contaminated foods, which account for 88-98% of such contamination; in other words, diet is the major source of human exposure to these contaminants (Rey-Salgueiro et al., 2008). Both the World Health Organization and the UK Expert Panel on Air Quality Standards (EPAQS) have considered benzo(a)pyrene (BaP) as a marker of the carcinogenic potency of the polycyclic aromatic hydrocarbons (PAH) mixture (Delgado-Saborit et al., 2011). Polycyclic aromatic and heavier aliphatic hydrocarbons, which have a stable recalcitrant molecular structure, exhibit high hydrophobicity and low aqueous solubility, are not readily removed from soil through leaching and volatilization (Brassington et al., 2007). The hydrophobicity of PAHs limits desorption to the aqueous phase (Donlon et al., 2002). Six main ways of dissipation, i.e. disappearance, are recognized in the environment: volatilization, photooxidation, Aim of the Work chemical oxidation, sorption, leaching and biodegradation. Microbial degradation is considered to be the main process involved in the dissipation of PAH (Yuan et al., 2002). Thus, more and more research interests are turning to the biodegradation of PAHs. Some microorganisms can utilize PAHs as a source of carbon and energy so that PAHs can be degraded to carbon dioxide and water, or transformed to other nontoxic or low-toxic substances (Perelo, 2010). Compared with other physical and chemical methods such as combustion

  7. A systematic review on the effects of polycyclic aromatic hydrocarbons on cardiometabolic impairment

    Directory of Open Access Journals (Sweden)

    Parinaz Poursafa

    2017-01-01

    Full Text Available Background: Various epidemiological studies have shown that exposure to environmental pollutants including polycyclic aromatic hydrocarbons (PAHs might increase the risk of cardiovascular diseases (CVDs and their risk factors. This study aims to systematically review the association of PAH exposure with metabolic impairment. Methods: Data were collected by searching for relevant studies in international databases using the following keywords: “polycyclic aromatic hydrocarbon” + “cardiovascular disease,” PAH + CVD, polycyclic aromatic hydrocarbon and “air pollutant” + “CVD,” and the desired data were extracted and included in the study according to the systematic review process. Results: From the 14 articles included in the present systematic review, eight articles were conducted on the relationship between PAH and CVDs, four articles were conducted to examine the association of PAH exposure with blood pressure (BP, and two articles investigated the link between PAH and obesity. Conclusions: Most studies included in this systematic review reported a significant positive association of PAH exposure with increased risk of CVDs and its major risk factors including elevated BP and obesity. These findings should be confirmed by longitudinal studies with long-term follow-up.

  8. [Polycyclic aromatic hydrocarbons in the beans, peas and broad beans from domestic market, 1999-2002].

    Science.gov (United States)

    Bałdyga, Barbara; Zbigniew, Borejszo; Wieczorek, Jolanta; Dymkowska-Malesa, Maria; Smoczyńtski, Stefan S

    2005-01-01

    Seeds of bean, peas and broad bean, purchased from local seed production plants in the provinces of Mazowieckie and Kujawsko-Pomorskie in the years 1999-2002, were determined for the contents of fifteen polycyclic aromatic hydrocarbons. The hydrocarbons were extracted from the seeds with a hexane-acetone mixture by means of sonification. The obtained extracts were then purified in a silica gel column. Polycyclic aromatic hydrocarbons (PAH) were identified and determined quantitatively with liquid chromatography using a fluorescent detector. The presence (in different concentrations) of PAH was reported in the majority of seeds of the bean, peas and broad bean varieties examined, which indicates that they may be ingested with food and bioaccumulated in the human organism. A considerably higher content of SPAH was observed in the seeds of broad bean, compared to those of bean and peas. The highest SPAH determined reached 2 x 10(2) microg/kg of product. The obtained results were comparable with those reported by other authors for vegetables originating from non-industrial areas. It is worth emphasising that all the seeds examined revealed the presence of PAH with carcinogenic properties.

  9. Biocatalytic upgrading of petroleum distillates: ring cleavage of aromatic hydrocarbons and heterocycles commonly present in petroleum distillates

    Energy Technology Data Exchange (ETDEWEB)

    Fogth, J. M.; Wu, Q.; Fedorak, P. M.; Pickard, M. A. [Alberta Univ., Edmonton, AB (Canada); Gray, M. R. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical Engineering

    1997-09-01

    The potential exists for microorganisms to selectively cleave the aromatic rings enzymatically under near-ambient conditions, yielding products that are more susceptible to hydrogenation than their parent compounds. In order to improve the understanding of this process, preliminary trials dealing with the first stage of the potential process were carried out using Pseudomonas fluorescens LP6a. This organism oxidizes (by enzymatic action) a wide range of aromatic hydrocarbons and heterocycles commonly present in petroleum middle distillate fractions. Mutants were generated and shown by mass spectrometry to produce the predicted aromatic ring fission products without carbon loss from pure aromatic substrates. The aromatic hydrocarbons and heterocycles dissolved in heptamethylnonane were transformed without altering the aliphatic carrier. 11 refs., 1 tab., 5 figs.

  10. Current State of Knowledge in Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs): A Review

    Science.gov (United States)

    Ghosal, Debajyoti; Ghosh, Shreya; Dutta, Tapan K.; Ahn, Youngho

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed toward removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of PAHs. The main

  11. Current state of knowledge in microbial degradation of polycyclic aromatic hydrocarbons (PAHs: a review

    Directory of Open Access Journals (Sweden)

    Debajyoti Ghosal

    2016-08-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed towards removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of

  12. C-H and N-H bond dissociation energies of small aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Barckholtz, C.; Barckholtz, T.A.; Hadad, C.M.

    1999-01-27

    A survey of computational methods was undertaken to calculate the homolytic bond dissociation energies (BDEs) of the C-H and N-H bonds in monocyclic aromatic molecules that are representative of the functionalities present in coal. These include six-membered rings (benzene, pyridine, pyridazine, pyrimidine, pyrazine) and five-membered rings (furan, thiophene, pyrrole, oxazole). By comparison of the calculated C-H BDEs with the available experimental values for these aromatic molecules, the B3LYP/6-31G(d) level of theory was selected to calculate the BDEs of polycyclic aromatic hydrocarbons (PAHs), including carbonaceous PAHs (naphthalene, anthracene, pyrene, coronene) and heteroatomic PAHs (benzofuran, benzothiophene, indole, benzoxazole, quinoline, isoquinoline, dibenzofuran, carbazole). The cleavage of a C-H or a N-H bond generates a {sigma} radical that is, in general, localized at the site from which the hydrogen atom was removed. However, delocalization of the unpaired electron results in {approximately} 7 kcal {center{underscore}dot} mol{sup {minus}1} stabilization of the radical with respect to the formation of phenyl when the C-H bond is adjacent to a nitrogen atom in the azabenzenes. Radicals from five-membered rings are {approximately} 6 kcal {center{underscore}dot} mol{sup {minus}1} less stable than those formed from six-membered rings due to both localization of the spin density and geometric factors. The location of the heteroatoms in the aromatic ring affects the C-H bond strengths more significantly than does the size of the aromatic network. Therefore, in general, the monocyclic aromatic molecules can be used to predict the C-H BDE of the large PAHs within 1 kcal {center{underscore}dot} mol{sup {minus}1}.

  13. Polycyclic aromatic hydrocarbons in pine and spruce shoots-temporal trends and spatial distribution.

    Science.gov (United States)

    Schröter-Kermani, Christa; Kreft, Dirk; Schilling, Bernd; Herrchen, Monika; Wagner, Gerhard

    2006-08-01

    In the framework of the German environmental specimen bank one-year old spruce shoots (Picea abies) and pine shoots (Pinus sylvestris) serve as bioindicators for the atmospheric pollution. Sampling is performed in two urbanized areas in western and eastern Germany (Warndt and Duebener Heide, respectively), and in seven different rural locations. Prior to archiving conifer shoots are continuously analyzed for a set of 17 individual polycyclic aromatic hydrocarbons (PAHs). The results from the two urbanized areas show that the atmospheric contamination with PAH has declined by about 75% between 1985 and 2004 at Warndt and by about 85% between 1991 and 2004 at Duebener Heide. However, summation operatorPAH concentrations stayed virtually constant at both locations since the end of the 1990s at levels of about 100 ng g(-1) wet weight (ww). In spruce shoots from rural areas current concentrations of PAHs are significantly lower and vary between 8 and 61 ng g(-1) ww. In all shoot samples the four low molecular aromatics phenanthrene, fluoranthene, pyrene, and chrysene dominate the pattern by contributing 60 to 90% to summation operatorPAH. The group of high molecular weight aromatics is dominated by benzo[b,j,k]fluoranthene, especially in spruce shoots originating from greater altitudes remarkable amounts of six and seven ringed PAHs could be detected. Despite the strong decrease of PAH concentrations in urban areas patterns of aromatics remained nearly unchanged in the observation period 1985 to 2004.

  14. Non-linear, cata-Condensed, Polycyclic Aromatic Hydrocarbon Materials: A Generic Approach and Physical Properties.

    Science.gov (United States)

    Haire, Barnaby T; Heard, Kane W J; Little, Mark S; Parry, Adam V S; Raftery, James; Quayle, Peter; Yeates, Stephen G

    2015-07-06

    A generic approach to the regiospecific synthesis of halogenated polycyclic aromatics is made possible by the one- or two-directional benzannulation reactions of readily available (ortho-allylaryl)trichloroacetates (the "BHQ" reaction). Palladium-catalysed cross-coupling reactions of the so-formed haloaromatics enable the synthesis of functionalised polycyclic aromatic hydrocarbons (PAHs) with surgical precision. Overall, this new methodology enables the facile mining of chemical space in search of new electronic functional materials. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  15. Magnetic ionic liquids as non-conventional extraction solvents for the determination of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Trujillo-Rodríguez, María J; Nacham, Omprakash; Clark, Kevin D; Pino, Verónica; Anderson, Jared L; Ayala, Juan H; Afonso, Ana M

    2016-08-31

    This work describes the applicability of magnetic ionic liquids (MILs) in the analytical determination of a group of heavy polycyclic aromatic hydrocarbons. Three different MILs, namely, benzyltrioctylammonium bromotrichloroferrate (III) (MIL A), methoxybenzyltrioctylammonium bromotrichloroferrate (III) (MIL B), and 1,12-di(3-benzylbenzimidazolium) dodecane bis[(trifluoromethyl)sulfonyl)]imide bromotrichloroferrate (III) (MIL C), were designed to exhibit hydrophobic properties, and their performance examined in a microextraction method for hydrophobic analytes. The magnet-assisted approach with these MILs was performed in combination with high performance liquid chromatography and fluorescence detection. The study of the extraction performance showed that MIL A was the most suitable solvent for the extraction of polycyclic aromatic hydrocarbons and under optimum conditions the fast extraction step required ∼20 μL of MIL A for 10 mL of aqueous sample, 24 mmol L(-1) NaOH, high ionic strength content of NaCl (25% (w/v)), 500 μL of acetone as dispersive solvent, and 5 min of vortex. The desorption step required the aid of an external magnetic field with a strong NdFeB magnet (the separation requires few seconds), two back-extraction steps for polycyclic aromatic hydrocarbons retained in the MIL droplet with n-hexane, evaporation and reconstitution with acetonitrile. The overall method presented limits of detection down to 5 ng L(-1), relative recoveries ranging from 91.5 to 119%, and inter-day reproducibility values (expressed as relative standard derivation) lower than 16.4% for a spiked level of 0.4 μg L(-1) (n = 9). The method was also applied for the analysis of real samples, including tap water, wastewater, and tea infusion. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baoliang, E-mail: blchen@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Yuan Miaoxin; Liu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2011-04-15

    Graphical abstract: The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants. Research highlights: {yields} Polycyclic aromatic hydrocarbons are effectively removed by plant residues. {yields} Biosorption mechanism of plant residues to abate PAHs is a partitioning process. {yields} Partition coefficients are negatively related with sugar contents of biosorbent. {yields} The aromatic component and K{sub ow} exhibit positive effects on biosorption. {yields} The structure-effect relationship guides plant residue using as a biosorbent. - Abstract: To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N{sub 2} surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K{sub d}) followed the order of PN > BL > OP > RR > WC, ranged from 2484 {+-} 24.24 to 5306 {+-} 92.49 L/kg. Except the WC sample, the K{sub d} values were negatively correlated with sugar content, polar index [(N + O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K{sub oc}) were linearly correlated with octanol-water partition coefficients (K{sub ow}) of PAHs, i.e., log K{sub oc} = 1.16 log K{sub ow} - 1.21. The structure-effect relationship provides a reference to select and modify plant residues as a

  17. Polycyclic aromatic hydrocarbons and the Oak Ridge National Laboratory's experimental coal program: minimizing the hazards

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, R.C. III; Cochran, H.D.; Bolton, N.E.

    1977-01-01

    Many processing techniques for the liquefaction or gasification of coal are being developed at the Oak Ridge National Laboratory and elsewhere. Although different in many other respects, all coal conversion processes produce a liquid effluent comprising a complex mixture of hydrocarbons. Such mixtures invariably contain significant amounts of polycyclic, aromatic compounds, some of which are known to be highly active carcinogens. The underlying philosophy that has been adopted for the protection of personnel involved in experimental coal processing operations is defined, and procedures that have been instituted to govern the conduct of such experimental work and handling of associated coal-derived liquids are detailed.

  18. Entanglement and polyradical character of polycyclic aromatic hydrocarbons predicted by projected Hartree-Fock theory.

    Science.gov (United States)

    Rivero, Pablo; Jiménez-Hoyos, Carlos A; Scuseria, Gustavo E

    2013-10-24

    We study strong correlation effects in a series of fused benzene rings (acenes) of varying length and width using our recently developed projected Hartree-Fock (PHF) method. These molecules, commonly known as polycyclic aromatic hydrocarbons or nanographenes, are very challenging for electronic structure theory because of their strong multireference character. This challenge is here met by PHF at moderate computational cost optimizing a spin eigenfunction obtained by projection of an unrestricted Hartree-Fock (UHF) trial determinant. The resulting method, known as SUHF, predicts that polyradical behavior and orbital entanglement are enhanced with molecular size, especially in systems whose structural motifs are dominated by zigzag edges, like oligoacenes.

  19. Polycyclic Aromatic Hydrocarbons via Iron(III)-Catalyzed Carbonyl-Olefin Metathesis.

    Science.gov (United States)

    McAtee, Christopher C; Riehl, Paul S; Schindler, Corinna S

    2017-03-01

    Polycyclic aromatic hydrocarbons are important structural motifs in organic chemistry, pharmaceutical chemistry, and materials science. The development of a new synthetic strategy toward these compounds is described based on the design principle of iron(III)-catalyzed carbonyl-olefin metathesis reactions. This approach is characterized by its operational simplicity, high functional group compatibility, and regioselectivity while relying on FeCl 3 as an environmentally benign, earth-abundant metal catalyst. Experimental evidence for oxetanes as reactive intermediates in the catalytic carbonyl-olefin ring-closing metathesis has been obtained.

  20. Interrelationship of Pyrogenic Polycyclic Aromatic Hydrocarbon (PAH Contamination in Different Environmental Media

    Directory of Open Access Journals (Sweden)

    Un Hyuk Yim

    2009-11-01

    Full Text Available Interrelationships between pyrogenic polycyclic aromatic hydrocarbons (PAHs were assessed in air, soil, water, sediment, and tree leaves by using multi-media monitoring data. Concurrent concentration measurements were taken bimonthly for a year for the multi-media at urban and suburban sites. PAH level correlations between air and other media were observed at the urban site but were less clear at the suburban site. Considering a closer PAHs distribution/fate characteristics to soil than suspended solids, contamination in sediment seemed to be governed primarily by that in soil. The partitioning of PAHs in waters could be better accounted for by sorption onto black carbon and dissolved organic carbon.

  1. Polycyclic aromatic hydrocarbons study in Taichung, Taiwan, during 2002-2003

    Science.gov (United States)

    Fang, Guor-Cheng; Wu, Yuh-Shen; Chen, Ming-Hsiang; Ho, Tse-Tsung; Huang, Shih-Han; Rau, Jui-Yeh

    The concentrations of ambient air polycyclic aromatic hydrocarbons were measured simultaneously from August 2002 to July 2003 in an industrial area (Taichung Industrial Park) and a suburban area (Tunghai University) in central Taiwan. Particle-bound PAH were collected on quartz filters and gas-phase PAH on glass cartridges using polyurethane foam sampler. Both types of samples used soxhlet analytical method and were subjected to gas chromatography-mass spectrometric analysis. Diagnostic ratios and principal component analysis were also used to characterize and identify PAH emission source in this study.

  2. Extraction of polycyclic aromatic hydrocarbons from smoked fish using pressurized liquid extraction with integrated fat removal

    DEFF Research Database (Denmark)

    Lund, Mette; Duedahl-Olesen, Lene; Christensen, Jan H.

    2009-01-01

    Quantification of polycyclic aromatic hydrocarbons (PAHs) in smoked fish products often requires multiple clean-up steps to remove fat and other compounds that may interfere with the chemical analysis. We present a novel pressurized liquid extraction (PLE) method that integrates exhaustive...... extraction with fat retention in one single analytical step. The PLE parameters: type of fat retainer, flush volume, solvent composition, fat-to-fat retainer ratio (FFR), and the dimensions of the extraction cells were the most important factors for obtaining fat-free extracts with high recoveries of PAHs...

  3. Polycyclic aromatic hydrocarbons in food and beverages. Analytical methods and trends.

    Science.gov (United States)

    Plaza-Bolaños, Patricia; Frenich, Antonia Garrido; Vidal, José Luis Martínez

    2010-10-08

    Polycyclic aromatic hydrocarbons (PAHs) are compounds widespread in the environment, many of them showing carcinogenic effects. These compounds can reach the food chain by different ways and, therefore, the analysis of PAHs in food is a matter of concern. This article reviews the extraction methodologies together with the separation and detection techniques which are currently applied in the determination of PAHs in food and beverages. Specific extraction conditions, performance characteristics, chromatographic and detection parameters are discussed. A review of the occurrence of these compounds in the matrixes under study is also provided. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Correlation of levels of volatile versus carcinogenic particulate polycyclic aromatic hydrocarbons in air samples from smokehouses

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Christensen, J M

    1991-01-01

    In the present study, data on the concentration of polycyclic aromatic hydrocarbons (PAH) in air samples from fish smokehouses (Nordholm et al. 1986) and meat smokehouses (Hansen et al. submitted for publication) were used to analyze the extent to which six different volatile PAH compounds could...... carcinogenic PAH compounds in air samples from smokehouses, whereas fluoranthene and pyrene displayed the highest specificity. However, when the applicability of the six markers was tested on air samples from iron foundries, only naphthalene and pyrene were useful as markers for the carcinogenic compounds...

  5. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil

    DEFF Research Database (Denmark)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J

    2006-01-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63...... for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.......) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several...

  6. Pollution by polycyclic aromatic hydrocarbons (PAH's) in sediments and organisms from Salina Cruz Port, Oaxaca, Mexico

    International Nuclear Information System (INIS)

    Botello, A.V.; Villanueva, S.; Diaz, G.; Pica, Y.

    1995-01-01

    The presence and levels of polycyclic aromatic hydrocarbons (PAH's) in [sediments and biota from the Port of Salina Cruz, Oaxaca; were evaluated by means of gas capillary chromatography using columns of high resolution. The results show a seasonal variability of the PAH's concentrations in sediments being higher in the port area and lower in oceanic sediments. The increase of the PAH's levels in Crassostrea iridiscens and Penaeus stylirostris is important and related to the bioaccumulation process. The presence of PAH's conformed by 4 y 5 benzene rings in these species must be noted specially because they have carcinogenic properties and their effects on the local fisheries should be considered. (Author)

  7. A review on polycyclic aromatic hydrocarbons: Source, environmental impact, effect on human health and

    Directory of Open Access Journals (Sweden)

    Hussein I. Abdel-Shafy

    2016-03-01

    The aim of this review is to discuss PAHs impact on the environmental and the magnitude of the human health risks posed by such substances. They also contain important information on concentrations, burdens and fate of polycyclic aromatic hydrocarbons (PAHs in the atmosphere. The main anthropogenic sources of PAHs and their effect on the concentrations of these compounds in air are discussed. The fate of PAHs in the air, their persistence and the main mechanisms of their losses are presented. Health hazards associated with PAH air pollution are stressed.

  8. Emission of Polycyclic Aromatic Hydrocarbons from the Exhalation Zones of Thermally Active Mine Waste Dumps

    Directory of Open Access Journals (Sweden)

    Patrycja Kuna-Gwoździewicz

    2013-01-01

    Full Text Available The article presents results of research carried out on the occurrence of polycyclic aromatic hydrocarbons (PAH in gases of exhalation zones, created on the surface of a thermally active coal mine waste dump. The oxidation and self-heating of mine waste are accompanied with the intensive emission of flue gases, including PAH group compounds. Taking into consideration the fact the hydrocarbons show strong genotoxic, mutagenic and carcinogenic properties, research was conducted to establish their content in the examined gases. The research object was a gangue dump located in Rybnik. The research was performed in 2012. In total, 24 samples of gas were collected with PUF (polyurethane foam sampling cartridges with a quartz fibre filter and an aspirator. The collected samples were analysed with the use of high performance liquid chromatography (HPLC and a fluorescence detector (FLD to evaluate the amount of PAH present.

  9. The carriers of the unidentified infrared emission features: Clues from polycyclic aromatic hydrocarbons with aliphatic sidegroups

    Science.gov (United States)

    Yang, X. J.; Glaser, R.; Li, Aigen; Zhong, J. X.

    2017-04-01

    The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 μ m are ubiquitously seen in a wide variety of astrophysical regions in the Milky Way and nearby galaxies as well as distant galaxies at redshifts z ≳ 4. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials. The 3.3 μ m feature which results from the C-H stretching vibration in aromatic species is often accompanied by a weaker feature at 3.4 μ m. The 3.4 μ m feature is often thought to result from the C-H stretch of aliphatic groups attached to the aromatic systems. The ratio of the observed intensity of the 3.3 μ m aromatic C-H feature (I3.3) to that of the 3.4 μ m aliphatic C-H feature (I3.4) allows one to estimate the aliphatic fraction (e.g., NC, aliph/NC, arom, the number of C atoms in aliphatic units to that in aromatic rings) of the carriers of the UIE features, provided that the intrinsic oscillator strengths (per chemical bond) of the 3.3 μ m aromatic C-H stretch (A3.3) and the 3.4 μ m aliphatic C-H stretch (A3.4) are known. In this review we summarize the computational results on A3.3 and A3.4 and their implications for the aromaticity and aliphaticity of the UIE carriers. We use density functional theory and second-order perturbation theory to derive A3.3 and A3.4 from the infrared vibrational spectra of seven polycyclic aromatic hydrocarbon (PAH) molecules with various aliphatic substituents (e.g., methyl-, dimethyl-, ethyl-, propyl-, butyl-PAHs, and PAHs with unsaturated alkyl chains). The mean band strengths of the aromatic (A3.3) and aliphatic (A3.4) C-H stretches are derived and then employed to estimate the aliphatic fraction of the carriers of the UIE features by comparing the ratio of the intrinsic band strength of the two stretches (A3.4/A3.3) with the ratio of the observed intensities (I3.4/I3.3). We conclude that the UIE emitters are predominantly aromatic, as revealed by the observationally

  10. Distributions of nitrated polycyclic aromatic hydrocarbons in the sediment of Osaka Bay, Japan.

    Science.gov (United States)

    Uno, Seiichi; Tanaka, Hiroyuki; Kokushi, Emiko; Bacolod, Eugene T; Koyama, Jiro

    2017-11-30

    The distributions of 15 nitrated polycyclic aromatic hydrocarbons (NPAHs) in sediments collected at 44 sites throughout Osaka Bay, Japan were examined. The highest total NPAHs, with a concentration of 1949ng/kg dry weight, were detected near the city of Amagasaki. Some sites near the cities of Osaka, Kishiwada, sand Sakai registered ng/kg levels of NPAHs, but individual NPAH concentrations were relatively lower than those in previous studies. The sources were estimated using principal component analysis, and NPAHs were derived from exhaust gases of automobiles and industries at some sites. However, our results suggest that it is difficult to estimate the source, especially in coastal areas near big cities and large industrial areas, because the generation pathways between parent polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs are slightly different, and the ratio of PAHs and NPAHs could not be accurately reflect the characters of sources in sediments especially at coastal areas with large-scale industrial zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. [Polycyclic aromatic hydrocarbons monohydroxy metabolites level in urine of general population in eight provinces of China].

    Science.gov (United States)

    Huang, Chuanfeng; Zhang, Jing; Ding, Chunguang; Liu, Cuilan; Wang, Gang; Song, Xinkui; Huang, Hanlin; Zhu, Baoli; Shao, Hua; Zhao, Chunxiang; Han, Changcheng; Peng, Shanzhuo; Jiang, Xianlong; Yu, Shanfa; Ji, Hongrong; Zhang, Xiaoxi; Sun, Ran; Zheng, Yuxin; Yan, Huifang

    2014-02-01

    To assess the levels of polycyclic aromatic hydrocarbons monohydroxy metabolites in urine of general population in China among 8 provinces, provide the baseline of the metabolites in the general population. From 2009 to 2010, 18 120 subjects of general population aged 6-60 years old were recruited from 24 areas among 8 provinces in east, west and central areas of China mainland by cluster random sampling. The information of the living environment and health condition were collected by questionnaire and spot urine samples were collected, 4 680 urine samples were analysed by high performance liquid chromatography with tandem mass spectrometry, and monohydroxy metabolites distribution in urine among groups of gender and ages were analysed. Geometric means (GM) of 2-naphthol, 1-naphthol, 3-phenanthrol and 1-hydroxypyrene concentration in urine (95%CI) were 1.85 (1.75-1.95), 1.55 (1.50-1.61), 0.57 (0.54-0.59) and 0.82 (0.78-0.85) µg/L, respectively;and median are 2.44, population were significantly different (P population aged 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were 1.60, 1.56, 1.69, 2.23, 1.91 and 1.86 µg/L (χ(2) = 17.90, P population were different, it provided a basic data for the further study of polycyclic aromatic hydrocarbons biomonitoring in the population.

  12. Risk of human exposure to polycyclic aromatic hydrocarbons: A case study in Beijing, China

    International Nuclear Information System (INIS)

    Yu, Yanxin; Li, Qi; Wang, Hui; Wang, Bin; Wang, Xilong; Ren, Aiguo; Tao, Shu

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) can cause adverse effects on human health. The relative contributions of their two major intake routes (diet and inhalation) to population PAH exposure are still unclear. We modeled the contributions of diet and inhalation to the overall PAH exposure of the population of Beijing in China, and assessed their human incremental lifetime cancer risks (ILCR) using a Mont Carlo simulation approach. The results showed that diet accounted for about 85% of low-molecular-weight PAH (L-PAH) exposure, while inhalation accounted for approximately 57% of high-molecular-weight PAH (H-PAH) exposure of the Beijing population. Meat and cereals were the main contributors to dietary PAH exposure. Both gaseous- and particulate-phase PAHs contributed to L-PAH exposure through inhalation, whereas exposure to H-PAHs was mostly from the particulate-phase. To reduce the cancer incidence of the Beijing population, more attention should be given to inhaled particulate-phase PAHs with considerable carcinogenic potential. - Highlights: • We modeled the contributions of diet and inhalation to population PAH exposure. • Diet contributed 85% of population exposure to low molecular-weight PAHs. • Inhalation contributed 57% of population exposure to high molecular-weight PAHs. • The PAH exposure level with body-weight adjustment decreased with age increasing. • The population cancer risk of PAH exposure is lower than the serious risk level. - The exposure of the Beijing population to carcinogenic polycyclic aromatic hydrocarbons was mainly from inhaled particulate matter

  13. Monohydroxylated polycyclic aromatic hydrocarbons influence spicule formation in the early development of sea urchins (Hemicentrotus pulcherrimus).

    Science.gov (United States)

    Suzuki, Nobuo; Ogiso, Shouzo; Yachiguchi, Koji; Kawabe, Kimi; Makino, Fumiya; Toriba, Akira; Kiyomoto, Masato; Sekiguchi, Toshio; Tabuchi, Yoshiaki; Kondo, Takashi; Kitamura, Kei-ichiro; Hong, Chun-Sang; Srivastav, Ajai K; Oshima, Yuji; Hattori, Atsuhiko; Hayakawa, Kazuichi

    2015-05-01

    We previously demonstrated that monohydroxylated polycyclic aromatic hydrocarbons (OHPAHs), which are metabolites of polycyclic aromatic hydrocarbons (PAHs), act on calcified tissue and suppress osteoblastic and osteoclastic activity in the scales of teleost fish. The compounds may possibly influence other calcified tissues. Thus, the present study noted the calcified spicules in sea urchins and examined the effect of both PAHs and OHPAHs on spicule formation during the embryogenesis of sea urchins. After fertilization, benz[a]anthracene (BaA) and 4-hydroxybenz[a]anthracene (4-OHBaA) were added to seawater at concentrations of 10(-8) and 10(-7) M and kept at 18 °C. The influence of the compound was given at the time of the pluteus larva. At this stage, the length of the spicule was significantly suppressed by 4-OHBaA (10(-8) and 10(-7) M). BaA (10(-7) M) decreased the length of the spicule significantly, while the length did not change with BaA (10(-8) M). The expression of mRNAs (spicule matrix protein and transcription factors) in the 4-OHBaA (10(-7) M)-treated embryos was more strongly inhibited than were those in the BaA (10(-7) M)-treated embryos. This is the first study to demonstrate that OHPAHs suppress spicule formation in sea urchins. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Binding of polycyclic aromatic hydrocarbons by humic acids formed during composting

    International Nuclear Information System (INIS)

    Plaza, Cesar; Xing Baoshan; Fernandez, Jose M.; Senesi, Nicola; Polo, Alfredo

    2009-01-01

    Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene and pyrene. Further, isotherm deviation from linearity was larger for soil HA than for organic substrate HAs, indicating a larger heterogeneity of binding sites in the former. The composting process decreased the binding affinity and increased the heterogeneity of binding sites of HAs. The changes undergone by the HA fraction during composting may be expected to contribute to facilitate microbial accessibility to PAHs. The results obtained also suggest that bioremediation of PAH-contaminated soils with matured compost, rather than with fresh organic amendments, may result in faster and more effective cleanup. - Composting of organic materials decreases the binding affinity of the humic acid fraction for polycyclic aromatic hydrocarbons

  15. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10

    Directory of Open Access Journals (Sweden)

    Tri Handayani Kurniati

    2016-12-01

    Full Text Available Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity.  Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene within 7 days. The result of nested PCR analysis revealed that this isolate possessed the nahAc gene which encodes dioxygenase enzyme for initial degradation of Polycyclic Aromatic Hydrocarbon (PAH. Observation of both tensio-active and emulsifying activities indicated that biosurfactants which produced by AMP 10 when grown on glucose could lower the surface tension of medium from 71.3 mN/m to 24.7 mN/m and formed a stable emulsion in used lubricant oil with an emulsification index (E24 of 74%. According to the results, it is suggested that the bacterial isolates G. cholesterolivorans AMP10 are suitable candidates for bioremediation of PAH-contaminated environments.How to CiteKurniati, T. H.,  Rusmana, I. Suryani, A. & Mubarik, N. R. (2016. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10. Biosaintifika: Journal of Biology & Biology Education, 8(3, 336-343. 

  16. Polycyclic aromatic hydrocarbon degradation by biosurfactant-producing Pseudomonas sp. IR1

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela); Synthesis and Biotics Div., Indian Oil Corp., Research and Development Center, Haryana (India); Leon, V.; Materano, A.D.S.; Ilzins, O.A.; Galindo-Castro, I.; Fuenmayor, S.L. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela)

    2006-03-15

    We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source. PCR and DNA hybridization studies showed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by IR1 during growth on both water miscible and immiscible substrates. The biosurfactants lowered the surface tension of medium from 54.9 dN cm{sup -1} to 35.4 dN cm{sup -1} and formed a stable and compact emulsion with an emulsifying activity of 74% with diesel oil, when grown on dextrose. These findings indicate that this isolate may be useful for bioremediation of sites contaminated with aromatic hydrocarbons. (orig.)

  17. Biodegradation of aged polycyclic aromatic hydrocarbons (PAHs) by microbial consortia in soil and slurry phases.

    Science.gov (United States)

    Li, Xiaojun; Li, Peijun; Lin, Xin; Zhang, Chungui; Li, Qi; Gong, Zongqiang

    2008-01-15

    Microbial consortia isolated from aged oil-contaminated soil were used to degrade 16 polycyclic aromatic hydrocarbons (15.72 mgkg(-1)) in soil and slurry phases. The three microbial consortia (bacteria, fungi and bacteria-fungi complex) could degrade polycyclic aromatic hydrocarbons (PAHs), and the highest PAH removals were found in soil and slurry inoculated with fungi (50.1% and 55.4%, respectively). PAHs biodegradation in slurry was lower than in soil for bacteria and bacteria-fungi complex inoculation treatments. Degradation of three- to five-ring PAHs treated by consortia was observed in soil and slurry, and the highest degradation of individual PAHs (anthracene, fluoranthene, and benz(a)anthracene) appeared in soil (45.9-75.5%, 62-83.7% and 64.5-84.5%, respectively) and slurry (46.0-75.8%, 50.2-86.1% and 54.3-85.7%, respectively). Therefore, inoculation of microbial consortia (bacteria, fungi and bacteria-fungi complex) isolated from in situ contaminated soil to degrade PAHs could be considered as a successful method.

  18. DNA-damage effect of polycyclic aromatic hydrocarbons from urban area, evaluated in lung fibroblast cultures

    International Nuclear Information System (INIS)

    Calesso Teixeira, Elba; Pra, Daniel; Idalgo, Daniele; Henriques, João Antonio Pêgas; Wiegand, Flavio

    2012-01-01

    This study was designed to biomonitor the effect of PAH extracts from urban areas on the DNA of lung cell cultures. The analyses of the polycyclic aromatic hydrocarbons (PAHs) were performed in atmospheric PM 2.5 and PM 10 collected at three sampling sites with heavy traffic located in the Metropolitan Area of Porto Alegre (MAPA) (Brazil). The concentrations of 16 major PAHs were determined according to EPA. Comet assay on V79 hamster lung cells was chosen for genotoxicity evaluation. Temperature, humidity, and wind speed were recorded. With regard to the damage index, higher levels were reported in the extract of particulate matter samples from the MAPA during the summer. High molecular weight compounds showed correlation with DNA damage frequency and their respective carcinogenicity. - Highlights: ► Cell line V79 was used to assess the effect of PAHs in PM 2.5 and PM 10 from urban area. ► Temperature showed a significant seasonal variation with the level of DNA damage. ► PAHs with higher molecular weight contributed to higher DNA damage levels. - DNA-damage effect of polycyclic aromatic hydrocarbons from urban area, showed difference according to season

  19. Chemistry of polycyclic aromatic hydrocarbons formation from phenyl radical pyrolysis and reaction of phenyl and acetylene.

    Science.gov (United States)

    Comandini, A; Malewicki, T; Brezinsky, K

    2012-03-15

    An experimental investigation of phenyl radical pyrolysis and the phenyl radical + acetylene reaction has been performed to clarify the role of different reaction mechanisms involved in the formation and growth of polycyclic aromatic hydrocarbons (PAHs) serving as precursors for soot formation. Experiments were conducted using GC/GC-MS diagnostics coupled to the high-pressure single-pulse shock tube present at the University of Illinois at Chicago. For the first time, comprehensive speciation of the major stable products, including small hydrocarbons and large PAH intermediates, was obtained over a wide range of pressures (25-60 atm) and temperatures (900-1800 K) which encompass the typical conditions in modern combustion devices. The experimental results were used to validate a comprehensive chemical kinetic model which provides relevant information on the chemistry associated with the formation of PAH compounds. In particular, the modeling results indicate that the o-benzyne chemistry is a key factor in the formation of multi-ring intermediates in phenyl radical pyrolysis. On the other hand, the PAHs from the phenyl + acetylene reaction are formed mainly through recombination between single-ring aromatics and through the hydrogen abstraction/acetylene addition mechanism. Polymerization is the common dominant process at high temperature conditions.

  20. Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

    Directory of Open Access Journals (Sweden)

    Pogorzelec Marta

    2017-01-01

    Full Text Available The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland. To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC. Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

  1. Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

    Directory of Open Access Journals (Sweden)

    Turk-Sekulić Maja M.

    2011-01-01

    Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

  2. Effects of oxygenated polycyclic aromatic hydrocarbons on the early life stages of Japanese medaka.

    Science.gov (United States)

    Kawano, Machi; Uno, Seiichi; Koyama, Jiro; Kokushi, Emiko; McElroy, Anne

    2017-12-01

    Oxygenated polycyclic aromatic hydrocarbons (oxyPAHs) are directly discharged into the atmosphere with exhaust gas from diesel engine automobiles and industry and are also generated by photo-oxidation and/or microbial metabolism of parent polycyclic aromatic hydrocarbons (PAHs). They are widely distributed in environment, especially around urban areas. We evaluated the effects of exposure to oxyPAHs as acenaphthenequinone (ANQ), 7,12-benz(a)anthracenequinone (BAQ), 1,4-naphthoquinone (NAQ), and 9,10-phenanethrenequinone (PHQ) in Japanese medaka (Oryzias latipes) embryos. ANQ (>2720 μg/L) caused caving in the yolk sac, and BAQ (>22.4 μg/L) caused tanning of the oil droplet. Additionally, NAQ (>314 μg/L) and PHQ (>734 μg/L) stopped development of medaka embryos beginning 2 days after the start of exposure. The hatched larvae from embryos exposed to ANQ, BAQ, NAQ, or PHQ at 518, 9.86, 36.5, or 80.7 μg/L, respectively, exhibited incomplete development of the cephalic region, incomplete palate, unabsorbed and hypertrophied yolk sac, tubular heart, altered axial curvature, and poor swimming ability. These symptoms were similar to those observed in blue sac disease, which is caused by exposure to PAHs.

  3. IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    M. Amzad Hossain

    2010-06-01

    Full Text Available A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC: n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate column was used, followed by glass fiber filter (GFF paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh.   Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS

  4. Functional diversity of bacterial genes associated with aromatic hydrocarbon degradation in anthropogenic dark earth of Amazonia

    Directory of Open Access Journals (Sweden)

    Mariana Gomes Germano

    2012-05-01

    Full Text Available The objective of this work was to evaluate the catabolic gene diversity for the bacterial degradation of aromatic hydrocarbons in anthropogenic dark earth of Amazonia (ADE and their biochar (BC. Functional diversity analyses in ADE soils can provide information on how adaptive microorganisms may influence the fertility of soils and what is their involvement in biogeochemical cycles. For this, clone libraries containing the gene encoding for the alpha subunit of aromatic ring-hydroxylating dioxygenases (α-ARHD bacterial gene were constructed, totaling 800 clones. These libraries were prepared from samples of an ADE soil under two different land uses, located at the Caldeirão Experimental Station - secondary forest (SF and agriculture (AG -, and the biochar (SF_BC and AG_BC, respectively. Heterogeneity estimates indicated greater diversity in BC libraries; and Venn diagrams showed more unique operational protein clusters (OPC in the SF_BC library than the ADE soil, which indicates that specific metabolic processes may occur in biochar. Phylogenetic analysis showed unidentified dioxygenases in ADE soils. Libraries containing functional gene encoding for the alpha subunit of the aromatic ring-hydroxylating dioxygenases (ARHD gene from biochar show higher diversity indices than those of ADE under secondary forest and agriculture.

  5. Polycyclic aromatic hydrocarbon (PAH) formation from benzyl radicals: a reaction kinetics study.

    Science.gov (United States)

    Sinha, Sourab; Raj, Abhijeet

    2016-03-21

    The role of resonantly stabilized radicals such as propargyl, cyclopentadienyl and benzyl in the formation of aromatic hydrocarbons such as benzene and naphthalene in the high temperature environments has been long known. In this work, the possibility of benzyl recombination to form three-ring aromatics, phenanthrene and anthracene, is explored. A reaction mechanism for it is developed, where reaction energetics are calculated using density functional theory (B3LYP functional with 6-311++G(d,p) basis set) and CBS-QB3, while temperature-dependent reaction kinetics are evaluated using transition state theory. The mechanism begins with barrierless formation of bibenzyl from two benzyl radicals with the release of 283.2 kJ mol(-1) of reaction energy. The further reactions involve H-abstraction by a H atom, H-desorption, H-migration, and ring closure to gain aromaticity. Through mechanism and rate of production analyses, the important reactions leading to phenanthrene and anthracene formation are determined. Phenanthrene is found to be the major product at high temperatures. Premixed laminar flame simulations are carried out by including the proposed reactions for phenanthrene formation from benzyl radicals and compared to experimentally observed species profiles to understand their effects on species concentrations.

  6. Activation of the aryl hydrocarbon receptor is the major toxic mode of action of an organic extract of a reference urban dust particulate matter mixture: The role of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Andrysik, Zdenek; Vondracek, Jan; Marvanova, Sona; Ciganek, Miroslav; Neca, Jiri; Pencikova, Katerina; Mahadevan, Brinda; Topinka, Jan; Baird, William M.; Kozubik, Alois; Machala, Miroslav

    2011-01-01

    Highlights: → SRM1649a extract and its fractions are potent activators of AhR in a model of epithelial cells. → AhR-dependent effects include both induction of CYP1 enzymes and disruption of cell proliferation control. → Polycyclic aromatic hydrocarbons present in the neutral SRM1649a fraction are major contributors to the AhR-mediated toxic effects. → Activation of AhR and related nongenotoxic effects occur at significantly lower doses than the formation of DNA adducts and activation of DNA damage response. → More attention should be paid to the AhR-dependent nongenotoxic events elicited by urban particulate matter constituents. - Abstract: Many of the toxic and carcinogenic effects of urban air pollution have been linked to polycyclic aromatic hydrocarbons (PAHs) adsorbed to airborne particulate matter (PM). The carcinogenic properties of PAHs in complex organic mixtures derived from PM have been chiefly attributed to their mutagenicity. Nevertheless, PAHs are also potent activators of the aryl hydrocarbon receptor (AhR), which may contribute to their nongenotoxic effects, including tumor promotion. As the genotoxicity of carcinogenic PAHs in complex mixtures derived from urban PM is often inhibited by other mixture constituents, the AhR-mediated activity of urban PM extracts might significantly contribute to the carcinogenic activity of such mixtures. In the present study, we used an organic extract of the urban dust standard reference material, SRM1649a, as a model mixture to study a range of toxic effects related to DNA damage and AhR activation. Both the organic extract and its neutral aromatic fraction formed a low number of DNA adducts per nucleotide in the liver epithelial WB-F344 cells model, without inducing DNA damage response, such as tumor suppressor p53 activation and apoptosis. In contrast, we found that this extract, as well as its neutral and polar fractions, were potent inducers of a range of AhR-mediated responses, including induction

  7. Alkane and polycyclic aromatic hydrocarbons in sediments and benthic invertebrates of the northern Chukchi Sea

    Science.gov (United States)

    Harvey, H. Rodger; Taylor, Karen A.

    2017-10-01

    The Hanna Shoal region represents an important northern gateway for transport and deposition in the Chukchi Sea. This study determined the concentration and distribution of organic contaminants (aliphatic hydrocarbon and polycyclic aromatic hydrocarbons, PAHs) in surface sediments from 34 sites across Hanna Shoal. Up to 31 total PAHs, including parent and alkyl homologues were detected with total concentrations ranging from a low of 168 ng g-1 the western flank of Hanna Shoal (station H34) to 1147 ng g-1 at station in Barrow Canyon (station BarC5). Alkyl PAHs were more abundant than parent structures and accounted for 53-64% of the summed concentrations suggesting overall at background levels (< 1600 ng g-1) in sediments. Alkane (C15-C33) hydrocarbons ranged from 4.3 μg g-1 on the southern flank of Hanna shoal to 31 μg g-1 at a northern station. Sediments were often dominated by short chain (C15-C22) alkanes with overall terrestrial aquatic ratios (TAR) for the region averaging 0.20. Based on the ratio of Fl/(Fl+ Py) and BaF/(Baf+BeP) verses (BA/BA+Ch) in sediments, PAHs are largely derived from petrogenic sources with minor amounts of mixed combustion sources. A diversity of PAHs were detected in the northern whelk Neptunea heros foot muscle with total concentrations ranging from 0.14 to 1.5 μg g-1 dry tissue wt. Larger (and presumably older) animals showed higher levels of PAH per unit muscle tissue, suggesting that animals may bioaccumulate PAHs over time, with low but increasing concentrations also present in internal and external eggs. Alkane hydrocarbons were also higher in whelks with distributions similar to that seen in sediments. The mussel Muscularus discors collected in Barrow Canyon showed constrained distributions and substantially lower concentrations of both PAHs and alkanes than the surrounding surface sediments.

  8. Influence of soil organic matter on the leaching of polycyclic aromatic hydrocarbons in soil.

    Science.gov (United States)

    Petruzzelli, L; Celi, L; Cignetti, A; Marsan, F Ajmone

    2002-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are one of the main classes of contaminants in the terrestrial environment. Aside from total organic carbon, the ratio among the different organic matter fractions [dissolved organic matter, fulvic acid (FA), humic acid (HA) and humin] can also affect the mobility of these hydrocarbons in soils. In this study the effect of the whole organic carbon pool has been compared with that of HA and FA on the translocation of four PAHs (biphenyl, fluorene, phenanthrene and pyrene) in soil columns. Oxidized and untreated soil columns with and without HA or FA, were prepared, spilled with hydrocarbons and leached with a 0.01 M CaCl2 solution. The influence of HA and FA on PAH translocation was investigated through determinations of the PAH contents and total organic carbon (TOC) in the layers of the columns. All molecules were moved vertically by the percolating solutions, their concentrations decreasing with depths. The nonoxidized soil tended to retain more PAHs (96%) than the oxidized one (60%), confirming that organic matter plays an important role in controlling PAH leaching. The whole organic matter pool reduced the translocation of pollutants downward the profile. The addition of HA enhanced this behaviour by increasing the PAH retention in the top layers (7.55 mg and 4.00 mg in the top two layers, respectively) while FA increased their mobility (only 2.30 and 2.90 mg of PAHs were found in the top layers) and favoured leaching. In fact, in the presence of HA alone, the higher amounts of PAHs retained at the surface and the good correlation (r2=0.936) between TOC and hydrocarbon distribution can be attributed to a parallel distribution of PAHs and HA, while in the presence of FA, the higher mobility of PAHs can be attributed to the high mobility of the humic material, as expected by its extensive hydrophilic characteristics.

  9. Geochemical interpretation of distribution of aromatic hydrocarbons in components of geologic environment of Pechora, Barents and Kara seas.

    Science.gov (United States)

    Kursheva, Anna; Petrova, Vera; Litvinenko, Ivan; Morgunova, Inna

    2017-04-01

    Information about the hydrocarbons content (including aromatic ones) in components of geologic environment allows to define common factors in distribution and correlation both nature and technogenic component, and also to reveal the sources of contamination. At that, it should be noted, that hydrocarbons are widely spread in lithosphere and create steady geochemical background, variations are caused here by specifics of initial organic matter, conditions of its accumulation and transformation. The basis of the study are the samples of sea water and deep sea sediments (more than 600 stations), collected in western sector of Arctic region (Pechora, Barents and Kara seas) during the scientific-research expeditions of FSBI "VNIIOkeangeologia" for the period 2000-2010. Total content of aromatic hydrocarbons was defined by spectrofluorometric method using analyzer «FLUORAT-Panorama-02». Certification of data was performed on representative samples based on contents and molecule structure of polycyclic aromatic hydrocarbons using GC-MS (Agilent 5973/6850 GC-MS System). Results of spectrofluorometric analysis of lipid fraction of organic matter of bottom sediments allowed to define specific parameters, which characterize various lithofacies groups of sediments. Thus, sandy residues are characterized by low level of aromatic hydrocarbons (ca. 4.3 μg/g) with prevalence of bi- and tri-aromatic compounds (λmax 270-310 nm). This correlates with low sorption capacity of coarse-grained sediments and absence of organic-mineral component, containing the breakdown products of initial organic matter. Tetra- and penta- aromatic structures prevail in clay sediments (ca. 13.0 μg/g), which are typical components of lipid fraction of organic matter of post sedimentation and early diagenetic stages of transformation. At that, changes of spectral characteristic of sediments in stratigraphic sequence completely reflect processes of diagenetic transformation of organic matter, including

  10. Volatilisation of aromatic hydrocarbons from soil: part II, fluxes from coal tar contaminated soils residing below the soil surface

    International Nuclear Information System (INIS)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons from coal tar contaminated soil, placed below a 5 cm deep layer of uncontaminated soil, were measured in the laboratory over a period of 53 days. The contaminated soil originated from a former gasworks site and contained concentrations of 11 selected aromatic hydrocarbons between 50 to 840 μg/cm 3 . Where the microbial activity was inhibited, the fluxes stabilized on a semi-steady-state level for the monocyclic aromatic hydrocarbons, naphthalene and 1-methylnaphthalene after a period of 10-20 days. Fluxes of acenaphthene and fluorene were only measurable in an experiment that utilized a cover soil with a low organic content. The fluxes were predicted by a numerical model assuming that the compounds acted independently of each other and that local equilibrium between the air, water, and sorbed phases existed. The model overestimated the fluxes for all the detected aromatic hydrocarbons by a factor of 1.3 to 12. When the cover soil was adapted to degrade naphthalene, the fluxes of naphthalene and 1-methylnaphthalene approached the detection limit after 5 to 8 days. Thereafter the fluxes of these two compounds were less than predicted by the model employing half-life values of 0.5 and 1 day for naphthalene and 1-methylnaphthalene respectively. 10 refs., 6 figs., 7 tabs

  11. Monitoring of polycyclic aromatic hydrocarbons (PAH) in food supplements containing botanicals and other ingredients on the Dutch market

    NARCIS (Netherlands)

    Martena, M.J.; Grutters, M.; Groot, de H.N.; Konings, E.J.M.; Rietjens, I.

    2011-01-01

    Food supplements can contain polycyclic aromatic hydrocarbons (PAH). The European Food Safety Authority (EFSA) has defined 16 priority PAH that are both genotoxic and carcinogenic and identified eight priority PAH (PAH8) or four of these (PAH4) as good indicators of the toxicity and occurrence of

  12. THE PENALIZED OPTIMAL EXPERIMENTAL DESIGN: THE PRECISE ESTIMATION OF AN INTERACTION THRESHOLD IN A MIXTURE OF EIGHTEEN POLYHALOGENATED AROMATIC HYDROCARBONS.

    Science.gov (United States)

    Crofton et al. (EHP, 2005) conducted a study of 18 polyhalogenated aromatic hydrocarbons (PHAHs) on serum total thyroxine (T4). Young female Long-Evans rats were dosed with the 18 single agents or a fixed-ratio mixture, and serum total T4 was measured via radioimmunoassay. The i...

  13. Including sorption to black carbon in modelling bioaccumulation of polycyclic aromatic hydrocarbons: Uncertainty analysis and comparison with field data

    NARCIS (Netherlands)

    Hauck, M.; Hendriks, A.J.; Huijbregts, M.J.A.; Koelmans, A.A.; Heuvel-Greve, van den M.J.; Moermond, C.T.A.; Veltman, K.; Vethaak, A.D.

    2007-01-01

    Model estimations of bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) have been higher than field or laboratory data. This has been explained by strong sorption to black carbon (BC). In this paper, eight previously published bioaccumulation datasets were reinterpreted in terms of

  14. Analysis of polycyclic aromatic hydrocarbons I. Determination by gas chromatography with glass and fused silica capillary columns

    International Nuclear Information System (INIS)

    Perez, M. M.; Gonzalez, D.

    1987-01-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column. The limitations and the advantages of the procedure are discussed in terms of separation efficiency, sensitivity and precision. (Author) 17 refs

  15. Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in the water-SPM-sediment system of Lake Chaohu, China

    DEFF Research Database (Denmark)

    Qin, Ning; He, Wei; Kong, Xiang-Zhen

    2014-01-01

    The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the water, suspended particular matter (SPM) and sediment from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The spatial-temporal distributions and the SPM-water partition of PAHs and their influenci...

  16. Impact of polychlorinated biphenyl and polycyclic aromatic hydrocarbon sequestration in sediment on bioaccumulation in aquatic food webs

    NARCIS (Netherlands)

    Moermond, C.T.A.; Roessink, I.; Jonker, M.T.O.; Meijer, T.; Koelmans, A.A.

    2007-01-01

    It is not clear whether sequestration or aging of organic chemicals like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) limits accumulation in higher levels of aquatic food chains. Therefore, the effect of aging on accumulation was studied in 1-m3 model ecosystems that

  17. In vivo and in vitro polycyclic aromatic hydrocarbons degradation by Lentinus (Panus) tigrinus CBS 577.79

    Czech Academy of Sciences Publication Activity Database

    Covino, S.; Svobodová, Kateřina; Křesinová, Zdena; Petruccioli, M.; Federici, F.; D’Annibale, A.; Čvančarová, Monika; Cajthaml, Tomáš

    2010-01-01

    Roč. 101, č. 9 (2010), s. 3004-3012 ISSN 0960-8524 R&D Projects: GA MŠk 2B06156 Institutional research plan: CEZ:AV0Z50200510 Keywords : Lentinus (Panus) tigrinus * Ligninolytic enzymes * Polycyclic aromatic hydrocarbons Subject RIV: EE - Microbiology, Virology Impact factor: 4.365, year: 2010

  18. Bioavailability of polycyclic aromatic hydrocarbons in soils and sediments: prediction of bioavailability and characterization of organic matter domains

    NARCIS (Netherlands)

    Cuypers, C.

    2001-01-01

    Polycyclic aromatic hydrocarbons (PAHs) constitute a group of priority pollutants which are of increasing environmental concern because of their adverse effects on humans, animals, and plants. Soils and sediments generally serve as a sink for PAHs, which leads to the accumulation of PAHs at

  19. Co-Transport of Polycyclic Aromatic Hydrocarbons by Motile Microorganisms Leads to Enhanced Mass Transfer under Diffusive Conditions

    DEFF Research Database (Denmark)

    Gilbert, Dorthea; Jakobsen, Hans H.; Winding, Anne

    2014-01-01

    as sink and source for polycyclic aromatic hydrocarbons (PAHs). This resulted in stable concentration gradients in water (>24 h). Adding the model organism Tetrahymena pyriformis to the experimental system enhanced PAH mass transfer up to hundred-fold (benzo[a]pyrene). Increasing mass transfer enhancement...

  20. Analysis of polycyclic aromatic hydrocarbons. I. Determination by gas chromatography with glass and fused solica capillary columns

    International Nuclear Information System (INIS)

    Perez Garcia, M.; Gonzalez, D.

    1987-01-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons is presented. The separation has been carried out by glass and fused silice capillary column. The limitations and the advantages of the procedure are discussed in terms of separation efficiency, sensitivity and precision. (author). 3 figs., 17 refs

  1. Solubility of solid polycyclic aromatic hydrocarbons in pressurized hot water at temperatures from 313 K to the melting point

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Planeta, Josef; Roth, Michal

    2006-01-01

    Roč. 51, č. 2 (2006), s. 616-622 ISSN 0021-9568 R&D Projects: GA ČR GA203/03/0859 Institutional research plan: CEZ:AV0Z40310501 Keywords : polycyclic aromatic hydrocarbon * solid solubility * pressurized hot water Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.642, year: 2006

  2. Equilibrium passive sampling as a tool to study polycyclic aromatic hydrocarbons in Baltic Sea sediment pore-water systems

    DEFF Research Database (Denmark)

    Lang, Susann-Cathrin; Hursthouse, Andrew; Mayer, Philipp

    2015-01-01

    Solid Phase Microextraction (SPME) was applied to provide the first large scale dataset of freely dissolved concentrations for 9 polycyclic aromatic hydrocarbons (PAHs) in Baltic Sea sediment cores. Polydimethylsiloxane (PDMS) coated glass fibers were used for ex-situ equilibrium sampling followed...

  3. Infrared spectroscopy of gas-phase polycyclic aromatic hydrocarbon cations in the 10-50 m spectral range

    NARCIS (Netherlands)

    Bakker, J.M.; Redlich, B.; Meer, A.F.G.; Oomens, J.

    2011-01-01

    The gas-phase infrared spectra of four polycyclic aromatic hydrocarbon (PAH) cations have been recorded in the 10-50 μm (or 1000-200 cm-1) spectral range via IR multiple photon dissociation (IRMPD) spectroscopy. Ionized PAHs are formed by UV laser ionization in an effusive beam and subsequently

  4. The occupational exposure of dermatology nurses to polycyclic aromatic hydrocarbons - evaluating the effectiveness of better skin protection.

    NARCIS (Netherlands)

    Scheepers, P.T.J.; Houtum, J.L.M. van; Anzion, R.B.M.; Champmartin, C.; Hertsenberg, S.; Bos, R.P.; Valk, P. van der

    2009-01-01

    OBJECTIVES: We studied the uptake of polycyclic aromatic hydrocarbons (PAH) in nurses who apply ointments containing coal tar to patients and investigated the effectiveness of skin protection methods. METHODS: We determined gas-phase PAH on XAD-2 and particle-associated PAH on filters. We also used

  5. Atmospheric polycyclic aromatic hydrocarbons (PAHs) in Asia: A review from 1999 to 2004

    International Nuclear Information System (INIS)

    Chang, K.-F.; Fang, G.-C.; Chen, J.-C.; Wu, Y.-S.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are present in both gaseous and particulate phases. These compounds are considered to be atmospheric contaminants and are human carcinogens. Many studies have monitored atmospheric particulate and gaseous phases of PAH in Asia over the past 5 years. This work compares and discusses different sample collection, pretreatment and analytical methods. The main PAH sources are traffic exhausts (AcPy, FL, Flu, PA, Pyr, CHR, BeP) and industrial emissions (BaP, BaA, PER, BeP, COR, CYC). PAH concentrations are highest in areas of traffic, followed by the urban sites, and lowest in rural sites. Meteorological conditions, such as temperature, wind speed and humidity, strongly affect PAH concentrations at all sampling sites. This work elucidates the characteristics, sources and distribution, and the healthy impacts of atmospheric PAH species in Asia. - This work summarizes the characteristics, sources and distribution, and the healthy impacts of atmospheric PAH species in Asia

  6. Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tokyo Metropolitan area.

    Science.gov (United States)

    Takada, H; Onda, T; Harada, M; Ogura, N

    1991-09-01

    Molecular distributions of polycyclic aromatic hydrocarbons (PAHs) in street dust samples collected from the Tokyo Metropolitan area were determined by capillary gas chromatography following HPLC fractionation. Three- to six-ring PAHs and sulfur-heterocyclics were detected. PAHs in the dusts were dominated by three and four unsubstituted ring systems with significant amounts of their alkyl homologues. PAHs were widely distributed in the streets, with concentrations (sigma COMB) of a few microgram/g dust. Automobile exhaust, asphalt, gasoline fuel, diesel fuel, tyre particles, automobile crankcase oils, and atmospheric fallout were also analysed. The PAH profile, especially the relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, indicated that PAHs in the street dusts from roads carrying heavy traffic are mainly derived from automobile exhausts; dusts from residential areas have a more significant contribution from atmospheric fallout.

  7. Photolysis of polycyclic aromatic hydrocarbons adsorbed on spruce [Picea abies (L.) Karst.] needles under sunlight irradiation

    International Nuclear Information System (INIS)

    Niu Junfeng; Chen Jingwen; Martens, D.; Quan Xie; Yang Fenglin; Kettrup, A.; Schramm, K.-W.

    2003-01-01

    Photolysis of PAHs on surfaces may determine their ultimate fate in the environment. - Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment

  8. The persistence of polynuclear aromatic hydrocarbons in sewage sludge-amended agricultural soils

    International Nuclear Information System (INIS)

    Wild, S.R.; Jones, K.C.; Berrow, M.L.

    1992-01-01

    In 1968 five metal enriched sewage sludges containing different concentrations of polynuclear aromatic hydrocarbons (PAHs) were applied to different plots on field soils at two experimental sites, Luddington and Lee Valley in the UK. This resulted in substantial increases in soil ΣPAH concentrations in all plots. Since application compound specific losses have occurred, with the high molecular weight PAHs being more persistent. Calculated half-lives range from under 2 years for naphthalene to over 9 years for benzo[ghi]perylene and coronene. The loss of PAH compounds in these field experiments can be related, in part, to certain physico-chemical properties, namely water solubility and the octanol:water partition coefficients. 20 refs., 3 figs., 1 tab

  9. Combined effects of heavy metal and polycyclic aromatic hydrocarbon on soil microorganism communities

    Science.gov (United States)

    Cao, Linkui; Shen, Guoqing; Lu, Yitong

    2008-06-01

    Soil contaminated sites contain a variety of pollutants, especially heavy metals and polycyclic aromatic hydrocarbons (PAHs). Interactions between heavy metals have been relatively well studied, but little is known about interactions between heavy metals and PAHs. The combined effect of heavy metals and PAHs on soil microorganism was studied in laboratory conditions and evaluated by random denaturing gradient gel electrophoresis. We extracted DNA directly from contaminated soils and then amplified the V3 sequences of the 16S rDNA. The results showed that with different culture time, the gene diversity of the single and combined contaminated soil differed as well. After 15 days of culture, the microorganisms were stimulated and accommodated. After 45 days of cultivation, the quantities of the soil microorganisms were affected. It is concluded that some of the microorganisms utilize phenanthrene as important carbon resources. Microorganisms directly isolated from soil could reflect the diversity of soil microorganism and population distribution conditions.

  10. Contamination of runoff waters with polycyclic aromatic hydrocarbons in the city of Siedlce

    Directory of Open Access Journals (Sweden)

    Kluska Mariusz

    2016-12-01

    Full Text Available The paper presents the results of the research on content of 16 polycyclic aromatic hydrocarbons in samples of runoff waters collected in Siedlce city. The samples were collected in March, July and October 2015. The highest mean total concentration of 16 PAHs amounting to 12.54 μmolּdm-3 was determined in water samples collected at Łukowska Street, whereas the lowest concentrations (1.90 μmolּdm-3 were found in samples collected at Warszawska Street. In some samples, small amounts of benzo(apyrene were present; the average content ranged from 0.02 μmol⋅dm-3 at Warszawska Street to 0.20 μmolּdm-3 at Garwolińska Street.

  11. Ecotoxicological risk of polycyclic aromatic hydrocarbons (PAHs) in urban soil of Isfahan metropolis, Iran.

    Science.gov (United States)

    Moore, F; Akhbarizadeh, R; Keshavarzi, B; Khabazi, S; Lahijanzadeh, A; Kermani, M

    2015-04-01

    Concentration, distribution, probable sources, and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 52 soil samples collected within a radius 50 km from Isfahan metropolis center. Total concentration of PAHs ranged from 57.70 to 11,730.08 μg/kg averaging 2,000.56 μg/kg. Spatial PAH profiles were site-specific and higher concentration of PAHs was observed in the vicinity of industrial zones within Isfahan metropolis. The molecular indices, ring classes, and principal component analysis indicated that the sources of PAHs were both geogenic and pyrogenic. The incremental lifetime cancer risks of exposure to soil PAHs for adults and children living in the study area were 2.3×10(-2) and 2.2×10(-3), respectively. The results suggest that current PAHs levels in Isfahan metropolis soil are highly carcinogenic and may hold a serious health risk for local resident.

  12. Clam bioaccumulation of Alkylphenols and Polyciclic aromatic hydrocarbons in the Venice lagoon under different pressures.

    Science.gov (United States)

    Ademollo, N; Patrolecco, L; Matozzo, V; Marin, M G; Valsecchi, S; Polesello, S

    2017-11-15

    Biota-Sediment Accumulation Factors (BSAFs) of nonylphenols (NPs) and polycyclic aromatic hydrocarbons (PAHs) in Ruditapes philippinarum from the Venice Lagoon (Italy) were determined with the aim to verify whether the routine biomonitoring studies are reliable in contaminated sites. Clams and sediments were collected in field campaigns (October 2003 to June 2004) in three sites of the Venice Lagoon. Results showed that Marghera and Campalto sediments were more contaminated by NPs and PAHs than Poveglia. Different trends were observed in the contamination of clams with the highest BSAFs found at Poveglia. BSAF trend appeared to be inversely related to the contaminant pressure on the sites. These results suggest that clam bioaccumulation is not always representative of the chemical pressure on aquatic biota. The direct correlation between sediment and biota concentrations in contaminated sites can be lost as a function of the site-specific conditions such as sediment toxicity and food availability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Occurrence of polycyclic aromatic hydrocarbons throughout the processing stages of erva-mate (Ilex paraguariensis).

    Science.gov (United States)

    Vieira, Manoela Alano; Maraschin, Marcelo; Rovaris, Angela Angeloni; Amboni, Renata Dias de Mello Castanho; Pagliosa, Cristiane Manfé; Xavier, José Júnior Mendonca; Amante, Edna Regina

    2010-06-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) in mate (Ilex paraguariensis) is believed to be due to the degradation of mate compounds and the burning of wood during the "sapeco" (rapid drying process) and the final drying steps, which are the most important processing stages in mate production. Due to the high toxicity of these compounds, studies on their presence in mate are extremely important. The aim of this study was to evaluate PAH levels in mate throughout the processing stages of its production. The PAHs were measured in samples collected at different stages of mate processing. Total PAHs content ranged widely (443-9001 microg/kg) in the samples, with the highest PAHs levels recorded during the mate drying step. The results indicate that the processing method currently used in mate production may lead to an increase in PAHs levels in the final product.

  14. 'Mussel Watch' and chemical contamination of the coasts by polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Farrington, J.W.

    1999-01-01

    Polycyclic aromatic hydrocarbons (PAH) enter the coastal marine environment from three general categories of sources; pyrogenic, petrogenic (or petroleum), and natural diagenesis. PAH from different sources appear to have differential biological availability related to how the PAH are sorbed, trapped, or chemically bound to particulate matter, including soot. Experience to date with bivalve sentinel organism, or 'Mussel Watch', monitoring programs indicates that these programs can provide a reasonable general assessment of the status and trends of biologically available PAH in coastal ecosystems. As fossil fuel use increases in developing countries, it is important that programs such as the International Mussel Watch Program provide assessments of the status and trends of PAH contamination of coastal ecosystems of these countries. (author)

  15. Polycyclic aromatic hydrocarbons in pyrogenic soils of swampy landscapes of the Meshchera lowland

    Science.gov (United States)

    Tsibart, A. S.; Gennadiev, A. N.; Koshovskii, T. S.; Gamova, N. S.

    2016-03-01

    The composition and distribution of polycyclic aromatic hydrocarbons (PAHs) were studied in organomineral and organic soils of the Meshchera National Park. It was found that the background oligotrophic peat soils unaffected by fires in central parts of the bogs are characterized by the increased PAH concentrations due to their high sorption capacity. The fires of 2007 and 2010 resulted in the transformation of the plant cover and soil morphology, the formation of new horizons, and the change in the PAHs content and composition. Significant burn-off of organic matter was found in oligotrophic-eutrophic soils and resulted in the decrease of PAHs content after fire. Only partial burn-off of organic horizons and intense formation of PAHs were recorded in the soil with initially great thickness of peat horizons. Pyrogenic accumulation of PAHs was identified in organomineral soils of the marginal parts of bogs and of forest sites.

  16. Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China.

    Science.gov (United States)

    Shi, Z; Tao, S; Pan, B; Liu, W X; Shen, W R

    2007-03-01

    Water, suspended particulate matter (SPM), and sediment samples were collected from ten rivers in Tianjin and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), dissolved organic carbon (DOC), particulate organic carbon (POC) in SPM and total organic carbon (TOC) in sediment. The behavior and fate of PAHs influenced by these parameters were examined. Generally, organic carbon was the primary factor controlling the behavior of the 16 PAH species. Partitioning of PAHs between SPM and water phase was studied, and K(OC) for some PAH species were found to be significantly higher than the predicted values. The source of PAHs contamination was diagnosed by using PAH isomer ratios. Coal combustion was identified to be a long-term and prevailing contamination source for sediment, while sewage/wastewater source could reasonably explain a short-term PAHs contamination of SPM.

  17. The Composition of Cigarette Smoke: A Catalogue of the Polycyclic Aromatic Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Rodgman A

    2014-12-01

    Full Text Available Classified as toxicants in many of the substances to which humans are exposed are the polycyclic aromatic hydrocarbons (PAHs. Such exposures include air pollutants from a variety of sources, foodstuffs and beverages, and tobacco smoke. Since the early 1950s, the composition of the latter has been more completely defined than that of any other consumer product. Nearly 4800 components have been identified in tobacco smoke and among these are over 500 PAHs either completely or partially identified. Because of the tumorigenicity of many PAHs, much research has been conducted in attempts to define the relationship between the PAH structures and their specific tumorigenicities in laboratory animals. None of the theories to date completely answers all the questions.

  18. Use of antioxidant enzymes of clam Ruditapes philippinarum as biomarker to polycyclic aromatic hydrocarbon pollution

    Science.gov (United States)

    Zhu, Lin; Tang, Xuexi; Wang, Ying; Sui, Yadong; Xiao, Hui

    2016-03-01

    The typical organic pollutant polycyclic aromatic hydrocarbon (PAH) anthracene was selected as a contaminant to investigate its effects on the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the clam Ruditapes philippinarum. The results show that SOD, CAT and GSH-Px had diff erent induction and inhibition reactions to anthracene stress, and that three diff erent organs in R. philippinarum (visceral mass, muscle tissue and mantle) had diff erent sensitivities to anthracene stress. This study suggest that SOD activities of the visceral mass, CAT activitities of the mantle and the visceral mass, and GSH-Px activity of the muscle tissue could be used as sensitive indicators of anthracene stress in R. philippinarum.

  19. Flow cytometry detection of planktonic cells with polycyclic aromatic hydrocarbons sorbed to cell surfaces

    KAUST Repository

    Cerezo, Maria I.

    2017-02-17

    Polycyclic aromatic hydrocarbons are very important components of oil pollution. These pollutants tend to sorb to cell surfaces, exerting toxic effects on organisms. Our study developed a flow cytometric method for the detection of PAHs sorbed to phytoplankton by exploiting their spectral characteristics. We discriminated between cells with PAHs from cells free of PAHs. Clear discrimination was observed with flow cytometer provided with 375 or 405nm lasers in addition to the standard 488nm laser necessary to identify phytoplankton. Using this method, we measured the relationship between the percentages of phytoplankton organisms with PAHs, with the decrease in the growth rate. Moreover, the development of this method could be extended to facilitate the study of PAHs impact on cell cultures from a large variety of organisms.

  20. Coordination of bis(tricarbonylchromium) complexes to small polycyclic aromatic hydrocarbons: Structure, relative stabilities, and bonding

    Science.gov (United States)

    Jiménez-Halla, J. Oscar C.; Robles, Juvencio; Solà, Miquel

    2008-11-01

    Bis(tricarbonylchromium) complexes of two- to four-fused benzenoid rings were investigated by means of the B3LYP method. Our analysis was focused on both the molecular structure of the different isomers and their relative energies. For all the studied cases, the isomer with the lowest energy resulted to be the anti where both Cr(CO) 3 units are bonded to the most external rings. According to the calculated dissociation energies for the lowest energy isomers, stabilization due to metal bicomplexation is similar in angular and linear polycyclic aromatic hydrocarbons (PAH), while the less energetically favorable complexation occurs in PAH with a compact arrangement of six-membered rings like in pyrene.

  1. Occurrence of polycyclic aromatic hydrocarbons in dust emitted from circulating fluidized bed boilers.

    Science.gov (United States)

    Kozielska, B; Konieczyńiski, J

    2008-11-01

    Occurrence of polycyclic aromatic hydrocarbons (PAHs) in granulometric fractions of dust emitted from a hard coal fired circulating fluidized bed (CFB) boiler was investigated. The dust was sampled with the use of a Mark III impactor. In each fraction of dust, by using gas chromatography (GC), 16 selected PAHs and total PAHs were determined and the toxic equivalent B(a)P (TE B(a)P) was computed. The results, recalculated for the standard granulometric fractions, are presented as concentrations and content of the determined PAHs in dust. Distributions of PAHs and their profiles in the granulometric dust fractions were studied also. The PAHs in dust emitted from the CFB boiler were compared with those emitted from mechanical grate boilers; a distinctly lower content of PAHs was found in dust emitted from the former.

  2. [Experimental research on alcohols, aldehydes, aromatic hydrocarbons and olefins emissions from alcohols fuelled vehicles].

    Science.gov (United States)

    Zhang, Fan; Wang, Jian-Hai; Wang, Xiao-Cheng; Wang, Jian-Xin

    2013-07-01

    Using two vehicles fuelled with pure gasoline, M15, M30 and pure gasoline, E10, E20 separately, 25 degrees C normal temperature type I emission test, -7 degrees C low temperature type VI emission test and type IV evaporation emission test were carried out. FTIR, HPLC and GC-MS methods were utilized to measure alcohols, aldehydes, aromatic hydrocarbons and olefins emissions. The test results indicate that at the low as well as normal ambient temperature, as the alcohols proportion increasing in the fuel, unburned methanol, formaldehyde, acetaldehyde increase proportionally, benzene, toluene, ethylene, propylene, 1,3-butadiene and isobutene decrease slightly. The unregulated emissions at the low ambient temperature are significantly higher than those at the normal ambient temperature. The difference of HC emissions in the entire process of evaporative emission tests of E10, gasoline and M15 fuels is slight. There is a small difference of unregulated emissions in the diurnal test of three fuels.

  3. Distribution and origin sources of Polycyclic Aromatic Hydrocarbons (PAHs) pollution in sediment of Sarawak coastal area

    International Nuclear Information System (INIS)

    Mohd Shuhaimi Elias; Abdul Khalik Wood; Zaleha Hashim; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Nazaratul Ashifa Abdullah Salim

    2010-01-01

    Alkyl and parent Polycyclic Aromatic Hydrocarbons (PAHs) compounds in marine sediment sample collected from ten locations along Sarawak coastal areas were extracted and analyzed by using gas chromatography-mass spectrometry. The source identification of PAH pollution in marine sediment of Sarawak coastal areas were identify by ratios technique of An/ An+phen, Fl/ Fl +Py, B[a]A/ (B[a]A+Chry) and total Methyl Phen/ Phen. The total alkyl and parent PAHs concentration varies from 36.5 - 277.4 ng/ g dry weight (d.w.) with a mean concentration of 138.2 ng/ g d.w. The ratio values of PAHs pollution in marine sediment of Sarawak coastal areas are clearly indicating the PAHs pollutions are originated from petroleum (petrogenic) and petroleum combustion (pyrolytic). However, the origin sources of PAHs pollution in a few stations were uncertain due to mixing sources of PAHs. (author)

  4. Biological risk and pollution history of polycyclic aromatic hydrocarbons (PAHs) in Nansha mangrove, South China.

    Science.gov (United States)

    Wu, Qihang; Leung, Jonathan Y S; Tam, Nora F Y; Chen, Shejun; Mai, Bixian; Zhou, Xizhen; Xia, Lihua; Geng, Xinhua

    2014-08-15

    Chinese government has taken various measures to alleviate pollution caused by polycyclic aromatic hydrocarbons (PAHs) in the region of Pearl River Delta since the economic reform in 1978, but the effectiveness of these measures remains largely unknown. This study aimed to elucidate the biological risk and pollution history of PAHs by measuring the concentrations of 28 PAHs in the surface and core sediments, respectively, in Nansha mangrove. Results found that the biological risk of PAHs was low without obvious spatial variation. The PAH concentration along the depth gradient indicated that PAH pollution was stabilized since the early 1990s while the source of PAHs has gradually changed from combustion of coal to petroleum products. This implied that the mitigation measures taken by the Chinese government were effective. Compared to marine bottom sediment, we propose that using mangrove sediment can provide a more accurate and precise estimate of pollution history of PAHs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Characterization of polycyclic aromatic hydrocarbon emission from open burning of joss paper

    Science.gov (United States)

    Rau, Jui-Yeh; Tseng, Hui-Hsin; Lin, Min-Der; Wey, Ming-Yen; Lin, Yu-Hao; Chu, Chien-Wei; Lee, Ching-Hwa

    The concentration of polycyclic aromatic hydrocarbons (PAHs) in the ambient air from a massive open burning of joss paper was simultaneously measured at an open-burning site (OS) and a downwind site (DS) from 6 to 8 August 2006. A total of 16 major PAHs (particle-bound and gas-phase) concentrations were extracted by the Soxhlet analytical method and analyzed by gas chromatography. The dominant PAHs of the total mass of the organic compound at both the sampling sites were low-molecular-weight species. Further, the results showed that the start burning/end burning-dominant PAH concentration ratios at the OS and DS were 10 and 6.2, respectively. Diagnostic ratios were also used in this study to characterize and identify the PAH emission sources. The results suggest that the characterization of air pollutants emitted from open-burning joss paper lies between furnace-burning joss paper and wood combustion.

  6. Polycyclic aromatic hydrocarbons in Tripuí River, Ouro Preto, MG, Brazil.

    Science.gov (United States)

    Brum, Daniel Mares; Pereira Netto, Annibal D

    2009-06-15

    This paper reports the determination of 15 EPA-polycyclic aromatic hydrocarbons (PAHs) and benzo[e]pyrene in water samples collected in Tripuí River, Ouro Preto City, MG, Brazil. Samples were collected between September 2006 (dry season) and November 2006 (wet season) in the neighborhood of an aluminum smelter. Detection limits and quantification limits were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian and USEPA legislations. Recoveries from water spiked samples were always larger than 89%. Fluoranthene, pyrene, phenanthrene, chrysene and benzo[b]fluoranthene predominated in the studied samples. The concentrations of PAHs upstream the aluminum smelter were systematically lower than those found downstream indicating a possible role of the smelter in the local pollution by PAHs. Principal component analysis and cluster analysis also showed remarkable differences of the characteristics of samples collected upstream and downstream the aluminum smelter and also of samples from wet and dry seasons.

  7. Interaction of oxides of nitrogen and aromatic hydrocarbons under simulated atmospheric conditions

    International Nuclear Information System (INIS)

    Obrien, R.J.; Green, P.J.; Doty, R.A.; Vanderzanden, J.W.; Easton, R.R.; Irwin, R.P.

    1979-01-01

    The reactions of nitrogen oxides with aromatic hydrocarbons under simulated atmospheric conditions are investigated. Gaseous reaction products formed when toluene is irradiated under simulated atmospheric conditions in the presence of nitrogen oxides were analyzed by gas chromatography. Reaction products detected include acetylene, water, acetaldehyde, acetone, toluene, benzaldehyde, ortho-, meta- and para-cresol, benzyl nitrate and meta- and para-nitrotoluene. Reaction mechanisms yielding the various products are illustrated. The assumption that all the nitrogen oxides observed to be lost from the reaction products can be accounted for by nitric acid formation in the absence of ozone formation is verified by a model in which the hydroxyl radical is assumed to be the only means of removing toluene. Under conditions in which ozone is formed, nitrogen oxide loss is accounted for by ozone formation in addition to nitric acid formation

  8. Sediment chronology and polycyclic aromatic hydrocarbon concentrations and fluxes in Cayuga Lake, NY

    Energy Technology Data Exchange (ETDEWEB)

    Heit, M.; Tan, Y.L.; Miller, K.M.; Quanci, J.; Marinetti, C.; Silvestri, S.; Swain, A.M.; Winkler, M.G.

    1986-02-01

    We describe experiments aimed at determining the deposition history of energy-related, particulate-associated, potentially carcinogenic polycyclic aromatic hydrocarbons (PAH) deposited in the sediments of Cayuga Lake in the Finger Lakes Region of Central New York State. The sediment cores were chronologically dated from measurements of artificial and natural radionuclides (/sup 137/Cs, Pu-isotopes, /sup 210/Pb) and pollen. Diatoms and charcoal were used to determine historic changes in the Cayuga Lake basin. These methods showed agreement in chronology and also indicated that the sediments were not mixed or diffused to any great extent so that clear pollutant trends could be established. Historic changes in concentrations (ng/g dry wt.) and flux (ng/cm/sup 2//yr) of 3 to 7 ring PAH compounds were determined. Estimates of the atmospheric component of PAH flux to the sediments were made using the ratio of /sup 137/Cs inventories in sediments to that deposited on undisturbed soils.

  9. Toxicity assessment of polycyclic aromatic hydrocarbons in sediments from European high mountain lakes.

    Science.gov (United States)

    Quiroz, Roberto; Grimalt, Joan O; Fernández, Pilar

    2010-05-01

    Sediment quality guidelines and toxic equivalent factors have been used for assessment of the toxicity of sedimentary long-range atmospherically transported polycyclic aromatic hydrocarbons (PAHs) to the organisms living in high mountain European lakes. This method has provided indices that are consistent with experimental studies evaluating in situ sedimentary estrogenic activity or physiological response to AhR binding in fish from the same lakes. All examined lakes in north, central, west, northeast and southeast European mountains have shown sedimentary PAH concentrations that are above thresholds of no effect but only those situated in the southeast lakes district exhibited concentrations above the indices of probable effects. These mountains, Tatras, are also those having PAH concentrations of highest activity for AhR binding. Chrysene+triphenylene, dibenz[a]anthracene, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene are the main compounds responsible for the observed toxic effects. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Static and Field-Oriented Properties of Bowl-Shaped Polynuclear Aromatic Hydrocarbon Fragments.

    Science.gov (United States)

    Zoppi, Laura; Ferretti, Andrea; Baldridge, Kim K

    2013-11-12

    First principles techniques are used to investigate the structure, linear polarizability, and field-oriented property trends of the series of bowl shaped polynuclear aromatic hydrocarbon fragments, C20H10, C30H10, C40H10, and C50H10. Such structures represent a sequence of minimalistic, capped bucky tube units based on the corannulene molecule, with interesting technological promise imparted by their curvature. Specific issues associated with how the intrinsic dipole and static linear polarizability influences the orientation of these structures in the presence of an external electric field are addressed and shown to correlate well with a simple analytical model. At moderate electric fields, the induced dipoles become comparable and even larger than the intrinsic dipoles due to the large in-plane polarizabilities in these systems. This generates a nontrivial and field dependent orientation of the molecule that can be exploited, for example, to induce switching behavior within molecular nanojunctions.

  11. Biodepuration of polynuclear aromatic hydrocarbons from a bivalve mollusc, Mercenaria mercenaria L

    International Nuclear Information System (INIS)

    Tanacredl, J.T.; Cardenas, R.R.

    1991-01-01

    Mercenaria mercenaria, exposed in vitro for 48 h to nine parent polynuclear aromatic hydrocarbons (PAHs) found in waste crankcase oil (WCCO) and analyzed by multiparametric analysis over a 45-day depuration period in an activated carbon filtration aquaria system, did not depurate PAHs, but rather maintained them at detectable levels. Uptake of PAHs was shown to be directly related to clam weight. A cluster analysis of empirical results reaffirmed a biostabilization in PAH groupings in clam tissue over a 45-day depuration period and exhibited no evidence of a decreasing trend in total PAHs when subjected to ANOVA. Due to the commercial importance of hard-shell clams, the practices of clam depuration and clam relaying are reviewed in light of potential long-terms public health exposures to low-level xenobiotics and the implications for human consumers

  12. Titanocene-Mediated Dinitrile Coupling: A Divergent Route to Nitrogen-Containing Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Kiel, Gavin R; Samkian, Adrian E; Nicolay, Amélie; Witzke, Ryan J; Tilley, T Don

    2018-02-21

    A general synthetic strategy for the construction of large, nitrogen-containing polycyclic aromatic hydrocarbons (PAHs) is reported. The strategy involves two key steps: (1) a titanocene-mediated reductive cyclization of an oligo(dinitrile) precursor to form a PAH appended with di(aza)titanacyclopentadiene functionality; (2) a divergent titanocene transfer reaction, which allows final-step installation of one or more o-quinone, diazole, or pyrazine units into the PAH framework. The new methodology enables rational, late-stage control of HOMO and LUMO energy levels and thus photophysical and electrochemical properties, as revealed by UV/vis and fluorescence spectroscopy, cyclic voltammetry, and DFT calculations. More generally, this contribution presents the first productive use of di(aza)metallacyclopentadiene intermediates in organic synthesis, including the first formal [2 + 2 + 2] reaction to form a pyrazine ring.

  13. Heavy metals and polycyclic aromatic hydrocarbons in surface sediments of Karoon River, Khuzestan Province, Iran.

    Science.gov (United States)

    Keshavarzi, Behnam; Mokhtarzadeh, Zeinab; Moore, Farid; Rastegari Mehr, Meisam; Lahijanzadeh, Ahmadreza; Rostami, Soqra; Kaabi, Helena

    2015-12-01

    Karoon is the longest river in Iran and provides water for industries located along its banks, such as metal, petrochemical, and oil industries. It is also the source of drinking water for cities such as Ahwas, Abadan, and Khorramshahr. In this study, 34 and 18 surface sediment samples were collected and analyzed for heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs). The measured concentrations of heavy metals were compared with US EPA sediment quality guidelines, and the results showed that Cu concentration was above the threshold effect level (TEL) in 65.67% of the samples and Hg concentration was above the effect range median (ERM) in some samples. The results revealed that Hg was severely enriched (5 soap factory and Abadan petrochemical complex. Principal component analysis and cluster analysis also revealed the relationships between the studied parameters and identified their probable sources.

  14. Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

    Science.gov (United States)

    Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

    2014-01-01

    Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

  15. Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

    Directory of Open Access Journals (Sweden)

    Seyedeh Belin Tavakoly Sany

    Full Text Available Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia. The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions, with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

  16. Biomonitoring seasonal variation of urban air polycyclic aromatic hydrocarbons (PAHs) using Ficus benghalensis leaves.

    Science.gov (United States)

    Prajapati, Santosh Kumar; Tripathi, B D

    2008-02-01

    Temporal and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) concentrations in leaves of Ficus benghalensis were investigated in Varanasi city (India). Leaf samples were collected from six sites from urban area of Varanasi and from a control site. PAH extraction was done by sonication in dichloromethane-acetone and quantification by GC-MS. In January total leaf PAHs concentrations at all the urban sites were twice higher as compared to other season's viz. summer and rainy. In contrast, at the control site leaf PAHs concentrations showed lower values than urban sites. The maximum concentrations of total PAHs in winter were due to the medium molecular weight PAHs which increases with respect to both low and high molecular weight PAHs. The temporal variation of medium molecular weight PAHs was similar both at the urban and remote sites. These results support biomonitoring ability of Ficus benghalensis leaves to temporal variations in PAHs contamination.

  17. Heavy Metals and Polycyclic Aromatic Hydrocarbons in Urban Leaf Litter Designated for Combustion

    Directory of Open Access Journals (Sweden)

    Meike Nitsche

    2017-03-01

    Full Text Available Vast amounts of leaf litter have to be disposed of by city administrations. This biomass has the potential for energy conversion, but contamination with pollutants can adversely affect this usage. We investigated leaf litter samples from the city of Kassel by analyzing their heavy metal and polycyclic aromatic hydrocarbon (PAH concentrations. Leaf samples were indeed contaminated with heavy metals and PAHs and contamination was influenced by provenience and collection technique. A simple cleaning system of washing and subsequent mechanical dewatering significantly reduced heavy metal concentration. Regression models were developed for contamination with heavy metals which showed that contamination could be successfully estimated using the total ash content of the sample as a predictor, with an R2 of up to 0.77. It can be concluded that leaf litter from cities is a possible feedstock for energetic conversion, provided a cleaning step is applied.

  18. Biodegradation, bioaccessibility, and genotoxicity of diffuse polycyclic aromatic hydrocarbon (PAH) pollution at a motorway site

    DEFF Research Database (Denmark)

    Johnsen, A.R.; de Lipthay, J.R.; Reichenberg, F.

    2006-01-01

    Diffuse pollution of surface soil with polycyclic aromatic hydrocarbons (PAHs) is problematic in terms of the large areas and volumes of polluted soil. The levels and effects of diffuse PAH pollution at a motorway site were investigated. Surface soil was sampled with increasing distance from...... in the most polluted samples close to the pavement. Hydroxypropyl-beta-cyclodextrin extraction of soil PAHs, as a direct estimate of the bioaccessibility, indicated that only 1-5% of the PAHs were accessible to soil bacteria. This low bioaccessibility is suggested to be due to sorption to traffic soot...... the asphalt pavement and tested for total amounts of PAHs, amounts of bioaccessible PAHs, total bacterial populations, PAH degrader populations, the potential for mineralization of C-14-PAHs, and mutagenicity. Elevated PAH concentrations were found in the samples taken 1-8 m from the pavement. Soil sampled...

  19. A review of atmospheric polycyclic aromatic hydrocarbons: sources, fate and behavior

    International Nuclear Information System (INIS)

    Baek, S.O.; Field, R.A.; Goldstone, M.E.; Kirk, P.W.; Lester, J.N.; Perry, R.

    1991-01-01

    A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the environment having been detected in remote areas of the world. This is thought to be due to long term transport in the atmosphere. PAH can also be subjected to chemical and/or photochemical change whilst resident in the atmosphere prior to their removal by either wet or dry deposition. 146 refs., 5 tabs

  20. Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

    KAUST Repository

    Cerezo, Maria Isabel

    2015-11-01

    One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers\\' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.

  1. Polycyclic aromatic hydrocarbons in ash: determination of total and leachable concentrations.

    Science.gov (United States)

    Enell, Anja; Fuhrman, Filippa; Lundin, Lisa; Warfvinge, Per; Thelin, Gunnar

    2008-03-01

    Before wood ash can be used as a soil fertilizer, concentrations of environmentally hazardous compounds must be investigated. In this study, total and leachable concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in four ash samples and one green liquor sludge. The ash sample with the highest carbon content also contained high levels of PAHs; three of the ash samples had total concentrations exceeding the limit permitted by the Swedish Forest Agency for recycling to forest soils. The leachable concentrations were higher for the non-stabilized samples; this was probably due to colloid-facilitated transport of the contaminants in these samples. However, the leachable concentrations were overall relatively low in all the samples studied. The amounts of PAHs introduced to forest soils by additions of stabilized, recyclable ash products will be determined primarily by the rate of weathering of the ash particles and the total concentration of contaminants.

  2. Characterisation and Treatment of Nano-sized Particles, Colloids and Associated Polycyclic Aromatic Hydrocarbons in Stormwater

    DEFF Research Database (Denmark)

    Nielsen, Katrine

    . The associated pollutants will, if not removed in stormwater treatment facilities, be discharged into receiving surface waters, due to enhanced transportation exerted by the colloids and nano-sized particles. More stormwater than previously is separated from wastewater and drained to stormwater treatment.......Since little is known about the colloids and nano-sized particle-enhanced transportation of pollutants in stormwater, it has been difficult to determine their quantitative role in the total release of pollutants into receiving waters.Therefore the main purpose of this thesis has been to document the presence...... and size distribution of colloids and nano-sized particles in stormwater, as well as quantify the particle-enhanced transportation of polycyclic aromatic hydrocarbons (PAHs) in stormwater. Stormwater from five sites in Europe was collected to characterise the particulate matter, colloids and nano...

  3. Differential immunomodulatory responses to nine polycyclic aromatic hydrocarbons applied by passive dosing

    DEFF Research Database (Denmark)

    Oostingh, Gertie J.; Smith, Kilian E. C.; Tischler, Ulrike

    2015-01-01

    and stable dissolved concentrations during in vitro testing, and was applied to control and maintain freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs) at levels up to their aqueous solubility limit. The immunomodulatory effects of 9 different PAHs at aqueous solubility on human...... bronchial epithelial cells were determined by analysing the cytoldne promoter expression of 4 different inflammatory cytokines using stably transfected recombinant A549 cell lines. Diverse immunomodulatory responses were found with the highest induction observed for the most hydrophobic PAHs chrysene, benzo...... at any of the concentrations tested. Overall, this study shows that (1) immunomodulatory effects of PAHs can be studied in vitro at controlled freely dissolved concentrations, (2) the most hydrophobic PAHs were the strongest inducers and (3) induction was often higher at lower exposure levels...

  4. Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

    Science.gov (United States)

    Nie, Zhiqiang; Yang, Yufei; Tang, Zhenwu; Liu, Feng; Wang, Qi; Huang, Qifei

    2014-11-01

    Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

  5. Overview of established and emerging treatment technologies for polycyclic aromatic hydrocarbons at wood preserving facilities

    International Nuclear Information System (INIS)

    Shearon, M.D.

    1992-01-01

    The contamination of soil and groundwater by polycyclic aromatic hydrocarbons (PAHs) is common to wood preserving facilities and manufactured gas plants. Since the inception of RCRA and CERCLA, much attention has been focused upon the remediation of both active and defunct wood preserving facilities. The experiences gleaned from the use of proven technologies, and more importantly, the lessons being learned in the trials of emerging technologies on creosote-derived PAH clean-ups at wood preserving sites, should have direct bearing on the clean-up of similar contaminants at MGP sites. In this paper, a review of several remedial actions using waste removal/disposal, on-site incineration, and bioremediation will be presented. Additionally, emerging technologies for the treatment of PAH-contaminated soil and water will be reviewed. Lastly, recent information on risk assessment results for creosote sites and treated PAH waste will be discussed

  6. Degradation of polycyclic aromatic hydrocarbons by a marine fluidized-bed enrichment

    International Nuclear Information System (INIS)

    Melin, E.S.; Puhakka, J.A.; Maennistoe, M.; Ferguson, J.F.

    1995-01-01

    Aerobic polycyclic aromatic hydrocarbon (PAH)-degrading bacteria from marine sediments were enriched and maintained in a fluidized-bed reactor (FBR). The FBR was continuously fed a mixture of naphthalene, biphenyl, 2-methylnaphthalene, 2,6-dimethylnaphthalene, acenaphthene, fluorene, and phenanthrene; and the effluent concentrations remained below 0.03 mg/L (detection limit) over a period of 6 months. In batch vial assays, the relative rates of PAH degradation were controlled by their solubilities and, in some cases, by their substitution patterns. The enrichment also degraded several other PAHs, including anthracene and pyrene. The results demonstrate that the predominant PAH constituents of coal-tar creosote can be degraded and that PAH-contaminated saline waters can be remediated by the marine enrichment

  7. Bioremediation of phenols and polycyclic aromatic hydrocarbons in creosote contaminated soil using ex-situ landtreatment.

    Science.gov (United States)

    Guerin, T F

    1999-03-19

    Soil from a former creosoting plant containing phenols and polycyclic aromatic hydrocarbons, was remediated using an ex-situ landtreatment process. Total 16 USEPA priority PAH and total phenol were reduced from 290 mg/kg and 40 mg/kg to bioremediation process involved soil mixing, aeration, and slow release fertilizer addition. The indigenous populations of PAH and phenol utilizing populations of microorganisms were shown to increase during the treatment process, indicating that biostimulation was effective. The most extensive degradation was apparent with the 2- and 3-ring PAH, with decreases of 97% and 82%, respectively. The higher molecular weight 3- and 4-ring PAH were degraded at slower rates, with reductions of 45% and 51%, respectively. Six-ring PAH were degraded the least with average reductions of < 35%. The residual concentrations of PAH and total phenol obtained in the study allowed the treated soil to be disposed of as low level contaminated landfill.

  8. Polycyclic aromatic hydrocarbons (PAHs) in atmospheric dustfall from the industrial corridor in Hubei Province, Central China.

    Science.gov (United States)

    Zhang, Jiaquan; Qu, Chengkai; Qi, Shihua; Cao, Junji; Zhan, Changlin; Xing, Xinli; Xiao, Yulun; Zheng, Jingru; Xiao, Wensheng

    2015-10-01

    Thirty atmospheric dustfall samples collected from an industrial corridor in Hubei Province, central China, were analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) to investigate their concentrations, spatial distributions, sources, and health risks. Total PAH concentrations (ΣPAHs) ranged from 1.72 to 13.17 µg/g and averaged 4.91 µg/g. High molecular weight (4-5 rings) PAHs averaged 59.67% of the ΣPAHs. Individual PAH concentrations were not significantly correlated with total organic carbon, possibly due to the semi-continuous inputs from anthropogenic sources. Source identification studies suggest that the PAHs were mainly from motor vehicles and biomass/coal combustion. The incremental lifetime cancer risks associated with exposure to PAHs in the dustfall ranged from 10(-4) to 10(-6); these indicate potentially serious carcinogenic risks for exposed populations in the industrial corridor.

  9. Consistent associations between hepatic lesions in english sole (Parophrys vetulus) and polycyclic aromatic hydrocarbons in bottom sediment

    Energy Technology Data Exchange (ETDEWEB)

    Landahl, J.T.; McCain, B.B.; Myers, M.S.; Brown, D.W. (National Oceanographic and Atmospheric Administration, Seattle, WA (USA) Univ. of Washington, Seattle (USA))

    1990-11-01

    A consistent and statistically significant association between prevalence of hepatic neoplasms in free-living sole (Parophrys vetulus) and levels of anthropogenic polycyclic aromatic hydrocarbons in bottom sediment from sites of fish capture was documented in a series of studies conducted over a period of 7 years in Puget Sound, Washington. This result strengthens the evidence supporting a causal relationship between exposure to sediment-associated hydrocarbons and development of hepatic neoplasms in this bottom-dwelling marine fish species. Prevalence of two other distinct categories of idiopathic hepatic lesions - megalocytic hepatosis and steatosis/hemosiderosis - also showed consistent, statistically significant associations with polycyclic aromatic hydrocarbon concentrations in bottom sediment, and association with prevalence of a third category (putatively preneoplastic foci of cellular alteration) approached statistical significance. On the basis of other studies, megalocytic hepatosis and foci of cellular alteration are both considered to be important precursor lesions in the stepwise histogenesis of hepatic neoplasms.

  10. Cancer Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Soils and Sediments of India: A Meta-Analysis

    Science.gov (United States)

    Tarafdar, Abhrajyoti; Sinha, Alok

    2017-10-01

    A carcinogenic risk assessment of polycyclic aromatic hydrocarbons in soils and sediments was conducted using the probabilistic approach from a national perspective. Published monitoring data of polycyclic aromatic hydrocarbons present in soils and sediments at different study points across India were collected and converted to their corresponding BaP equivalent concentrations. These BaP equivalent concentrations were used to evaluate comprehensive cancer risk for two different age groups. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties of risk estimation. The analysis denotes 90% cancer risk value of 1.770E-5 for children and 3.156E-5 for adults at heavily polluted site soils. Overall carcinogenic risks of polycyclic aromatic hydrocarbons in soils of India were mostly in acceptance limits. However, the food ingestion exposure route for sediments leads them to a highly risked zone. The 90% risk values from sediments are 7.863E-05 for children and 3.999E-04 for adults. Sensitivity analysis reveals exposure duration and relative skin adherence factor for soil as the most influential parameter of the assessment, followed by BaP equivalent concentration of polycyclic aromatic hydrocarbons. For sediments, biota to sediment accumulation factor of fish in terms of BaP is most sensitive on the total outcome, followed by BaP equivalent and exposure duration. Individual exposure route analysis showed dermal contact for soils and food ingestion for sediments as the main exposure pathway. Some specific locations such as surrounding areas of Bhavnagar, Raniganj, Sunderban, Raipur, and Delhi demand potential strategies of carcinogenic risk management and reduction. The current study is probably the first attempt to provide information on the carcinogenic risk of polycyclic aromatic hydrocarbons in soil and sediments across India.

  11. Cancer Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Soils and Sediments of India: A Meta-Analysis.

    Science.gov (United States)

    Tarafdar, Abhrajyoti; Sinha, Alok

    2017-10-01

    A carcinogenic risk assessment of polycyclic aromatic hydrocarbons in soils and sediments was conducted using the probabilistic approach from a national perspective. Published monitoring data of polycyclic aromatic hydrocarbons present in soils and sediments at different study points across India were collected and converted to their corresponding BaP equivalent concentrations. These BaP equivalent concentrations were used to evaluate comprehensive cancer risk for two different age groups. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties of risk estimation. The analysis denotes 90% cancer risk value of 1.770E-5 for children and 3.156E-5 for adults at heavily polluted site soils. Overall carcinogenic risks of polycyclic aromatic hydrocarbons in soils of India were mostly in acceptance limits. However, the food ingestion exposure route for sediments leads them to a highly risked zone. The 90% risk values from sediments are 7.863E-05 for children and 3.999E-04 for adults. Sensitivity analysis reveals exposure duration and relative skin adherence factor for soil as the most influential parameter of the assessment, followed by BaP equivalent concentration of polycyclic aromatic hydrocarbons. For sediments, biota to sediment accumulation factor of fish in terms of BaP is most sensitive on the total outcome, followed by BaP equivalent and exposure duration. Individual exposure route analysis showed dermal contact for soils and food ingestion for sediments as the main exposure pathway. Some specific locations such as surrounding areas of Bhavnagar, Raniganj, Sunderban, Raipur, and Delhi demand potential strategies of carcinogenic risk management and reduction. The current study is probably the first attempt to provide information on the carcinogenic risk of polycyclic aromatic hydrocarbons in soil and sediments across India.

  12. Removal and transformation of polycyclic aromatic hydrocarbons during electrocoagulation treatment of an industrial wastewater.

    Science.gov (United States)

    Gong, Chenhao; Shen, Gang; Huang, Haiou; He, Peiran; Zhang, Zhongguo; Ma, Baoqing

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are an important class of water pollutants because of their known ecological and human toxicity. Electrocoagulation (EC) is a promising technology for mitigating industrial wastewater pollution, but the removal and transformation of PAHs during EC treatment has not yet been understood. Therefore, a paper-making wastewater effluent (PMWW) was employed in this study to investigate the relationship between PAHs' removal and transformation during EC treatment. The results show that 86% of PAHs were effectively removed not only by the electro-oxidation reactions, but also by adsorption onto Fe hydroxide flocs. The removal and transformation of PAHs were related to the number of rings in their structures. Some PAHs composed of two aromatic rings (e.g., naphthaline and dimethylnaphthalene) were produced from humic acid-like and fulvic acid-like organics in PMWW, while PAHs with three to four rings were degraded, thus being removed efficiently. Therefore, PAH transformation during EC treatment exerted double-sided effects on the removal of PAHs; the net effect appeared to be positive. Overall, this study revealed the existence and importance of PAH transformation during EC treatment and provided useful guidance for pulp and paper mills to improve the design and operation of wastewater treatment facilities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Polycyclic aromatic hydrocarbons (PAHs) enriching antibiotic resistance genes (ARGs) in the soils.

    Science.gov (United States)

    Chen, Baowei; He, Rong; Yuan, Ke; Chen, Enzhong; Lin, Lan; Chen, Xin; Sha, Sha; Zhong, Jianan; Lin, Li; Yang, Lihua; Yang, Ying; Wang, Xiaowei; Zou, Shichun; Luan, Tiangang

    2017-01-01

    The prevalence of antibiotic resistance genes (ARGs) in modern environment raises an emerging global health concern. In this study, soil samples were collected from three sites in petrochemical plant that represented different pollution levels of polycyclic aromatic hydrocarbons (PAHs). Metagenomic profiling of these soils demonstrated that ARGs in the PAHs-contaminated soils were approximately 15 times more abundant than those in the less-contaminated ones, with Proteobacterial being the preponderant phylum. Resistance profile of ARGs in the PAHs-polluted soils was characterized by the dominance of efflux pump-encoding ARGs associated with aromatic antibiotics (e.g., fluoroquinolones and acriflavine) that accounted for more than 70% of the total ARGs, which was significantly different from representative sources of ARG pollution due to wide use of antibiotics. Most of ARGs enriched in the PAHs-contaminated soils were not carried by plasmids, indicating the low possibilities of them being transferred between bacteria. Significant correlation was observed between the total abundance of ARGs and that of Proteobacteria in the soils. Proteobacteria selected by PAHs led to simultaneously enriching of ARGs carried by them in the soils. Our results suggested that PAHs could serve as one of selective stresses for greatly enriching of ARGs in the human-impacted environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs by a Newly Isolated Strain from Oilfield Produced Water

    Directory of Open Access Journals (Sweden)

    Yi-Bin Qi

    2017-02-01

    Full Text Available The polycyclic aromatic hydrocarbon (PAH-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA and gas chromatography–mass spectrometry (GC–MS analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(apyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution.

  15. Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions

    International Nuclear Information System (INIS)

    Zhou, Hui; Wu, Chunfei; Onwudili, Jude A.; Meng, Aihong; Zhang, Yanguo; Williams, Paul T.

    2015-01-01

    Highlights: • PAH from pyrolysis of 9 MSW fractions was investigated. • Pyrolysis of plastics released more PAH than that of biomass. • Naphthalene was the most abundant PAH in the tar. • The mechanism of PAH release from biomass and plastics was proposed. - Abstract: The formation of 2–4 ring polycyclic aromatic hydrocarbons (PAH) from the pyrolysis of nine different municipal solid waste fractions (xylan, cellulose, lignin, pectin, starch, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) were investigated in a fixed bed furnace at 800 °C. The mass distribution of pyrolysis was also reported. The results showed that PS generated the most total PAH, followed by PVC, PET, and lignin. More PAH were detected from the pyrolysis of plastics than the pyrolysis of biomass. In the biomass group, lignin generated more PAH than others. Naphthalene was the most abundant PAH, and the amount of 1-methynaphthalene and 2-methynaphthalene was also notable. Phenanthrene and fluorene were the most abundant 3-ring PAH, while benzo[a]anthracene and chrysene were notable in the tar of PS, PVC, and PET. 2-ring PAH dominated all tar samples, and varied from 40 wt.% to 70 wt.%. For PS, PET and lignin, PAH may be generated directly from the aromatic structure of the feedstock

  16. Phototoxicity of individual polycyclic aromatic hydrocarbons and petroleum to marine invertebrate larvae and juveniles

    International Nuclear Information System (INIS)

    Pelletier, M.C.; Burgess, R.M.; Ho, K.T.; Kuhn, A.; McKinney, R.A.; Ryba, S.A.

    1997-01-01

    Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude of increase in PAH toxicity often exceeds a factor of 100. In the marine environment phototoxicity to marine organisms has not been reported for individual or complex mixtures of PAHs. In this study, larvae and juveniles of the bivalve, Mulinia lateralis, and juveniles of the mysid shrimp, Mysidopsis bahia, were exposed to individual known phototoxic PAHs (anthracene, fluoranthene, pyrene), as well as the water-accommodated fractions of several petroleum products (Fuel Oil number-sign 2, Arabian Light Crude, Prudhoe Bay Crude, Fuel Oil number-sign 6) containing PAHs. Phototoxicity of individual PAHs was 12 to >50,000 times that of conventional toxicity. Three of the petroleum products demonstrated phototoxicity while the lightest product, Fuel Oil number-sign 2, was not phototoxic at the concentrations tested. The phototoxicity of petroleum products appears to be dependent on the composition and concentrations of phototoxic PAHs present: lighter oils have fewer multiple aromatic ring, phototoxic compounds while heavier oils have higher levels of these types of molecules. This study shows that phototoxicity can occur in marine waters to marine species. Further, the occurrence of oil in marine waters presents the additional risk of phototoxicity not routinely assessed for during oil spills

  17. Side Group Addition to the Polycyclic Aromatic Hydrocarbon Coronene by Proton Irradiation in Cosmic Ice Analogs

    Science.gov (United States)

    Bernstein, Max P.; Moore, Marla H.; Elsila, Jamie E.; Sandford, Scott A.; Allamandola, Louis J.; Zare, Richard N.

    2003-01-01

    Ices at ~15 K consisting of the polycyclic aromatic hydrocarbon coronene (C24H12) condensed either with H2O, CO2, or CO in the ratio of 1:100 or greater have been subjected to MeV proton bombardment from a Van de Graaff generator. The resulting reaction products have been examined by infrared transmission-reflection-transmission spectroscopy and by microprobe laser-desorption laser-ionization mass spectrometry. Just as in the case of UV photolysis, oxygen atoms are added to coronene, yielding, in the case of H2O ices, the addition of one or more alcohol (OH) and ketone (>CO) side chains to the coronene scaffolding. There are, however, significant differences between the products formed by proton irradiation and the products formed by UV photolysis of coronene containing CO and CO2 ices. The formation of a coronene carboxylic acid (COOH) by proton irradiation is facile in solid CO but not in CO2, the reverse of what was previously observed for UV photolysis under otherwise identical conditions. This work presents evidence that cosmic-ray irradiation of interstellar or cometary ices should have contributed to the formation of aromatics bearing ketone and carboxylic acid functional groups in primitive meteorites and interplanetary dust particles.

  18. Vapor pressures and sublimation enthalpies of seven heteroatomic aromatic hydrocarbons measured using the Knudsen effusion technique

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, Jillian L., E-mail: JillianLGoldfarb@gmail.co [Division of Engineering, Brown University, Providence, RI 02912 (United States); Suuberg, Eric M., E-mail: Eric_Suuberg@brown.ed [Division of Engineering, Brown University, Providence, RI 02912 (United States)

    2010-06-15

    The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) g . mol{sup -1} were measured over the temperature range of (301 to 486) K using the isothermal Knudsen effusion technique. The compounds measured include: anthraquinone, 9-fluorenone, 9-fluorenone oxime, phenoxazine, phenoxathiin, and 9H-pyrido[3,4-b]indole. These solid-state sublimation measurements provided values that are compared to vapor pressures of parent aromatic compounds (anthracene and fluorene) and to others with substituent groups in order to examine the effects of alcohol, ketone, pyridine, and pyrrole functionality on this property. The enthalpies and entropies of sublimation for each compound were determined from the Clausius-Clapeyron equation. Though there is no consistent trend in terms of the effects of substitutions on changes in the enthalpy or entropy of sublimation, we note that the prevalence of enthalpic or entropic driving forces on vapor pressure depend on molecule-specific factors and not merely molecular weight of the substituents.

  19. Removal of polycyclic aromatic hydrocarbons from organic solvents by ashes wastes

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Gregorio, M.R.; Garcia-Falcon, M.S.; Martinez-Carballo, E. [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain); Simal-Gandara, J., E-mail: jsimal@uvigo.es [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain)

    2010-06-15

    Polycyclic aromatic hydrocarbons (PAHs) can be formed during the refinery processes of crude petroleum. Their removal is of great importance. The same happens with other organic solvents used for the extraction of PAHs (hexane, acetonitrile...), which can be polluted with PAHs. Kinetic and equilibrium batch sorption tests were used to investigate the effect of wood ashes wastes as compared to activated carbon on the sorption of three representative PAHs from n-hexane and acetonitrile. Mussel shell ashes were discarded for batch sorption experiments because they were the only ashes containing PAHs. The equilibrium time was reached at 16 h. Physical sorption caused by the aromatic nature of the compounds was the main mechanism that governed the PAHs removal process. Our investigation revealed that wood ashes obtained at lower temperature (300 deg. C) did not show any PAHs sorption, while ashes obtained at higher temperature (>500 deg. C) have adsorbent sites readily available for the PAH molecules. An increase in the molecular weight of PAHs has a strong effect on sorption wood ashes wastes. As low the wood ashes particle size as high the sorption of PAHs, as a result of differences in adsorbent sites. The performance of wood ash wastes vs. activated carbon to remove 10 PAHs from organic solvents is competitive in price, and a good way for waste disposal.

  20. Biotransformation of petroleum asphaltenes and high molecular weight polycyclic aromatic hydrocarbons by Neosartorya fischeri.

    Science.gov (United States)

    Hernández-López, E Lorena; Perezgasga, Lucia; Huerta-Saquero, Alejandro; Mouriño-Pérez, Rosa; Vazquez-Duhalt, Rafael

    2016-06-01

    Neosartorya fischeri, an Aspergillaceae fungus, was evaluated in its capacity to transform high molecular weight polycyclic aromatics hydrocarbons (HMW-PAHs) and the recalcitrant fraction of petroleum, the asphaltenes. N. fischeri was able to grow in these compounds as sole carbon source. Coronene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene, together with the asphaltenes, were assayed for fungal biotransformation. The transformation of the asphaltenes and HMW-PAHs was confirmed by reverse-phase high-performance liquid chromatography (HPLC), nano-LC mass spectrometry, and IR spectrometry. The formation of hydroxy and ketones groups on the PAH molecules suggest a biotransformation mediated by monooxygenases such as cytochrome P450 system (CYP). A comparative microarray with the complete genome from N. fischeri showed three CYP monooxygenases and one flavin monooxygenase genes upregulated. These findings, together with the internalization of aromatic substrates into fungal cells and the microsomal transformation of HMW-PAHs, strongly support the role of CYPs in the oxidation of these recalcitrant compounds.

  1. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water

    Science.gov (United States)

    Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

    2017-01-01

    The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography–mass spectrometry (GC–MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution. PMID:28241412

  2. Application of the luciferase recombinant cell culture bioassay system for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Ziccardi, Michael H; Gardner, Ian A; Denison, Michael S

    2002-10-01

    An aryl hydrocarbon (Ah) receptor-based luciferase cell culture bioassay developed to detect 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other halogenated aromatics was modified and optimized to detect and quantitate polycyclic aromatics (PAHs). Twenty-four PAHs were analyzed, and subsequent EC50 and EC20 concentrations (based on the median and 20% TCDD maximal response, respectively) and appropriate induction equivalency factors (calculated by comparison to the response obtained with TCDD) were determined from dose-response experiments. Six compounds were shown to be active in the system, with benzo[k]fluoranthene > benz[a,h]anthracene indeno[1,2,3-cd]pyrene > benzo[a]pyrene > benzo[b]fluoranthene > chrysene. A complex mixture of 16 PAHs was also analyzed using this system, and overall induction equivalency (or 1-EQ) of the mixture was shown to be very similar to that predicted from the sum of the activity estimated for each individual PAH. Overall, our results strongly support the use of this system for the detection and relative quantitation of Ah receptor-active PAHs.

  3. Isolation and characterization of polycyclic aromatic hydrocarbons-degrading Sphingomonas sp. strain ZL5.

    Science.gov (United States)

    Liu, Yongsheng; Zhang, Jie; Zhang, Zhongze

    2004-06-01

    A bacterial strain ZL5, capable of growing on phenanthrene as a sole carbon and energy source but not naphthalene, was isolated by selective enrichment from crude-oil-contaminated soil of Liaohe Oil Field in China. The isolate was identified as a Sphingomonas sp. strain on the basis of 16S ribosomal DNA analysis. Strain ZL5 grown on phenanthrene exhibited catechol 2,3-dioxygenase (C23O) activity but no catechol 1,2-dioxygenase, gentisate 1,2-dioxygenase, protocatechuate 3,4-dioxygenase and protocatechuate 4,5-dioxygenase activities. This suggests that the mode of cleavage of phenanthrene by strain ZL5 could be meta via the intermediate catechol, which is different from the protocatechuate way of other two bacteria, Alcaligenes faecelis AFK2 and Nocardioides sp. strain KP7, also capable of growing on phenanthrene but not naphthalene. A resident plasmid (approximately 60 kb in size), designated as pZL, was detected from strain ZL5. Curing the plasmid with mitomycin C and transferring the plasmid to E. coli revealed that pZL was responsible for polycyclic aromatic hydrocarbons degradation. The C23O gene located on plasmid pZL was cloned and overexpressed in E. coli JM109(DE3). The ring-fission activity of the purified C23O from the recombinant E. coli on dihydroxylated aromatics was in order of catechol > 4-methylcatechol > 3-methylcatechol > 4-chlorocatechol > 3,4-dihydroxyphenanthrene > 3-chlorocatechol.

  4. Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, C.L.; Lambert, A.B.; Lundstedt, S.; Tysklind, M.; White, P.A. [Health Canada, Ottawa, ON (Canada). Safe Environment Program

    2008-04-15

    The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.

  5. Assessing the ecological risk of polycyclic aromatic hydrocarbons in sediments at Langkawi Island, Malaysia.

    Science.gov (United States)

    Nasher, Essam; Heng, Lee Yook; Zakaria, Zuriati; Surif, Salmijah

    2013-01-01

    Tourism-related activities such as the heavy use of boats for transportation are a significant source of petroleum hydrocarbons that may harm the ecosystem of Langkawi Island. The contamination and toxicity levels of polycyclic aromatic hydrocarbon (PAH) in the sediments of Langkawi were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Ten samples were collected from jetties and fish farms around the island in December 2010. A gas chromatography/flame ionization detector (GC/FID) was used to analyse the 18 PAHs. The concentration of total PAHs was found to range from 869 ± 00 to 1637 ± 20 ng g⁻¹ with a mean concentration of 1167.00 ± 24 ng g⁻¹, lower than the SQG effects range-low (3442 ng g⁻¹). The results indicated that PAHs may not cause acute biological damage. Diagnostic ratios and principal component analysis suggested that the PAHs were likely to originate from pyrogenic and petrogenic sources. The toxic equivalent concentrations of the PAHs ranged from 76.3 to 177 ng TEQ/g d.w., which is lower compared to similar studies. The results of mean effects range-median quotient of the PAHs were lower than 0.1, which indicate an 11% probability of toxicity effect. Hence, the sampling sites were determined to be the low-priority sites.

  6. Limitations of the toxic equivalency factor (TEF) approach for risk assessment of halogenated aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Safe, S. [Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Physiology and Pharmacology

    1995-12-31

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons (HAHs) are present as complex mixtures of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in most environmental matrices. Risk management of these mixtures utilize the toxic equivalency factor (TEF) approach in which the TCDD (dioxin) or toxic equivalents of a mixture is a summation of the congener concentration (Ci) times TEF{sub i} (potency relative to TCDD) where. TEQ{sub mixture} = {Sigma}[Cil] {times} TEF{sub i}. TEQs are determined only for those HAHs which are aryl hydrocarbon (Ah) receptor agonists and this approach assumes that the toxic or biochemical effects of individual compounds in a mixture are additive. Several in vivo and in vitro laboratory and field studies with different HAH mixtures have been utilized to validate the TEF approach. For some responses, the calculated toxicities of PCDD/PCDF and PCB mixtures predict the observed toxic potencies. However, for fetal cleft palate and immunotoxicity in mice, nonadditive (antagonistic) responses are observed using complex PCB mixtures or binary mixtures containing an Ah receptor agonist with 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB153). The potential interactive effects of PCBs and other dietary Ah receptor antagonist suggest that the TEF approach for risk management of HAHs requires further refinement and should be used selectively.

  7. Polycyclic aromatic hydrocarbon formation during the gasification of sewage sludge in sub- and supercritical water: Effect of reaction parameters and reaction pathways.

    Science.gov (United States)

    Gong, Miao; Wang, Yulan; Fan, Yujie; Zhu, Wei; Zhang, Huiwen; Su, Ying

    2018-02-01

    The formation of polycyclic aromatic hydrocarbon is a widespread issue during the supercritical water gasification of sewage sludge, which directly reduces the gasification efficiency and restricts the technology practical application. The changes of the concentrations and forms as well as the synthesis rate of polycyclic aromatic hydrocarbons in the residues from supercritical water gasification of dewatered sewage sludge were investigated to understand influence factors and the reaction pathways. Results showed that the increase of reaction temperature during the heating period favours directly concentration of polycyclic aromatic hydrocarbon (especially higher-molecular-weight), especially when it raise above 300 °C. Lower heating and cooling rate essentially extend the total reaction time. Higher polycyclic aromatic hydrocarbon concentration and higher number of rings were generally promoted by lower heating and cooling rate, longer reaction time and higher reaction temperature. The lower-molecular-weight polycyclic aromatic hydrocarbons can be directly generated through the decomposition of aromatic-containing compounds in sewage sludge, as well as 3-ring and 4-ring polycyclic aromatic hydrocarbons can be formed by aromatization of steroids. Possible mechanisms of reaction pathways of supercritical water gasification of sewage sludge were also proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effects of methyl group on aromatic hydrocarbons on the nanostructures and oxidative reactivity of combustion-generated soot

    KAUST Repository

    Guerrero Peña, Gerardo D.J.

    2016-07-23

    The substituted and unsubstituted aromatic hydrocarbons, present in transportation fuels such as gasoline and diesel, are thought to be responsible for most of the soot particles produced during their combustion. However, the effects of the substituted alkyl groups on the aromatic hydrocarbons on their sooting tendencies, and on the physical and chemical properties of soot produced from them are not well understood. In this work, the effect of the presence of methyl groups on aromatic hydrocarbons on their sooting propensity, and on the oxidative reactivity, morphology, and chemical composition of soot generated from them in diffusion flames is studied using benzene, toluene, and m-xylene as fuels. Several experimental techniques including high resolution transmission electron microscopy and X-ray diffraction are used to identify the morphological changes in soot, whereas the elemental and thermo-gravimetric analyses, electron energy loss spectroscopy, and Fourier transform infrared spectroscopy are used to study the changes in its chemical properties and reactivity. The activation energies for soot oxidation are calculated at different conversion levels, and a trend in the reactivity of soots from benzene, toluene and m-xylene is reported. It is observed that the sizes of primary particles and graphene-like sheets, and the concentrations of aliphatics and oxygenated groups in soot particles decreased with the addition of methyl group(s) on the aromatic ring. The physicochemical changes in soot are found to support the oxidative reactivity trends. © 2016 The Combustion Institute

  9. NMR detects molecular interactions of graphene with aromatic and aliphatic hydrocarbons in water

    Science.gov (United States)

    Bichenkova, Elena V.; Raju, Arun P. A.; Burusco, Kepa K.; Kinloch, Ian A.; Novoselov, Kostya S.; Clarke, David J.

    2018-03-01

    Polyaromatic carbon is widely held to be strongly diamagnetic and hydrophobic, with textbook van der Waals and ‘π-stacked’ binding of hydrocarbons, which disrupt their self-assembled supramolecular structures. The NMR of organic molecules sequestered by polyaromatic carbon is expected to be dominated by shielding from the orbital diamagnetism of π electrons. We report the first evidence of very different polar and magnetic behavior in water, wherein graphene remained well-dispersed after extensive dialysis and behaved as a 1H-NMR-silent ghost. Magnetic effects dominated the NMR of organic structures which interacted with graphene, with changes in spin-spin coupling, vast increase in relaxation, line broadening and decrease in NMR peak heights when bound to graphene. However, the interactions were weak, reversible and did not disrupt organic self-assemblies reliant on hydrophobic ‘π-stacking’, even when substantially sequestered on the surface of graphene by the high surface area available. Interacting assemblies of aromatic molecules retained their strongly-shielded NMR signals and remained within self-assembled structures, with slower rates of diffusion from association with graphene, but with no further shielding from graphene. Binding to graphene was selective for positively-charged organic assemblies, weaker for non-aromatic and negligible for strongly-negatively-charged molecules, presumably repelled by a negative zeta potential of graphene in water. Stronger binders, or considerable excess of weaker binders readily reversed physisorption, with no evidence of structural changes from chemisorption. The fundamental nature of these different electronic interactions between organic and polyaromatic carbon is considered with relevance to electronics, charge storage, sensor, medical, pharmaceutical and environmental research.

  10. Bioaccumulation of polycyclic aromatic hydrocarbons and survival of earthworms (Eisenia andrei) exposed to biochar amended soils.

    Science.gov (United States)

    Malev, O; Contin, M; Licen, S; Barbieri, P; De Nobili, M

    2016-02-01

    Biochar has a charcoal polycyclic aromatic structure which allows its long half-life in soil, making it an ideal tool for C sequestration and for adsorption of organic pollutants, but at the same time raises concerns about possible adverse impacts on soil biota. Two biochars were tested under laboratory-controlled conditions on Eisenia andrei earthworms: a biochar produced at low temperature from wine tree cuttings (WTB) and a commercial low tar hardwood lump charcoal (HLB). The avoidance test (48-h exposure) showed that earthworms avoid biochar-treated soil with rates higher than 16 t ha(-1) for HLB and 64 t ha(-1) for WTB. After 42 days, toxic effects on earthworms were observed even at application rates (100 t ha(-1)) that are generally considered beneficial for most crops. The concentration of HLB and WTB required to kill half of earthworms' population (LC50; 95% confidence limits) in the synthetic OECD soil was 338 and 580 t ha(-1), respectively. Accumulation of polycyclic aromatic hydrocarbons (PAH) in earthworms exposed to the two biochar types at 100 t ha(-1) was tested in two soils of different texture. In biochar-treated soils, the average earthworm survival rates were about 64% in the sandy and 78% clay-loam soils. PAH accumulation was larger in the sandy soil and largest in soils amended with HLB. PAH with less than four rings were preferentially scavenged from the soil by biochars, and this behaviour may mask that of the more dangerous components (i.e. four to five rings), which are preferentially accumulated. Earthworms can accumulate PAH as a consequence of exposure to biochar-treated soils and transfer them along the food chain. Soil type and biochar quality are both relevant in determining PAH transfer.

  11. From Interstellar Polycyclic Aromatic Hydrocarbons and Ice to the Origin of Life

    Science.gov (United States)

    Allamandola, Louis

    2004-01-01

    Tremendous strides have been made in our understanding of interstellar material over the past twenty years thanks to significant, parallel developments in observational astronomy and laboratory astrophysics. Twenty years ago the composition of interstellar dust was largely guessed at, the concept of ices in dense molecular clouds ignored, and the notion of large, abundant, gas phase, carbon rich molecules widespread throughout the interstellar medium (ISM) considered impossible. Today the composition of dust in the diffuse ISM is reasonably well constrained to cold refractory materials comprised of amorphous and crystalline silicates mixed with an amorphous carbonaceous material containing aromatic structural units and short, branched aliphatic chains. In the dense ISM, the birthplace of stars and planets, these cold dust particles are coated with mixed molecular ices whose composition is very well constrained. Lastly, the signature of carbon-rich polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by early interstellar chemistry standards, is widespread throughout the Universe. The first part of this talk will describe how infrared studies of interstellar space, combined with laboratory simulations, have revealed the composition of interstellar ices (the building blocks of comets) and the high abundance and nature of interstellar PAHs. The laboratory database has now enabled us to gain insight into the identities, abundances, and physical state of many interstellar materials. Within a dense molecular cloud, and especially in the presolar nebula, the materials frozen into the interstellar/precometary ices are photoprocessed by ultraviolet light and produce more complex molecules. The remainder of the presentation will focus on the photochemical evolution of these materials and the possible role of these compounds on the to the carbonaceous components of micrometeorites, they are likely to have been important sources of complex materials on the early

  12. Formation of polycyclic aromatic hydrocarbons and soot in fuel-rich oxidation of methane in a laminar flow reactor

    DEFF Research Database (Denmark)

    Skjøth-Rasmussen, Martin Skov; Glarborg, Peter; Østberg, M.

    2004-01-01

    Conversion of methane to higher hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and soot was investigated under fuel-rich conditions in a laminar flow reactor. The effects of stoichiometry, dilution, and water vapor addition were studied at temperatures between 1073 and 1823 K. A chemical ...... decrease with increasing addition of water vapor. The effect is described qualitatively by the reaction mechanism. The enhanced oxidation of acetylene is attributed to higher levels of hydroxyl radicals, formed from the reaction between the water vapor and hydrogen atoms....

  13. Grating light reflection spectroelectrochemistry for detection of trace amounts of aromatic hydrocarbons in water

    Energy Technology Data Exchange (ETDEWEB)

    KELLY,MICHAEL J.; SWEATT,WILLIAM C.; KEMME,SHANALYN A.; KASUNIC,K.J.; BLAIR,DIANNA S.; ZAIDI,S.H.; MCNEIL,J.R.; BURGESS,L.W.; BRODSKY,A.M.; SMITH,S.A.

    2000-04-01

    Grating light reflection spectroscopy (GLRS) is an emerging technique for spectroscopic analysis and sensing. A transmission diffraction grating is placed in contact with the sample to be analyzed, and an incident light beam is directed onto the grating. At certain angles of incidence, some of the diffracted orders are transformed from traveling waves to evanescent waves. This occurs at a specific wavelength that is a function of the grating period and the complex index of refraction of the sample. The intensities of diffracted orders are also dependent on the sample's complex index of refraction. The authors describe the use of GLRS, in combination with electrochemical modulation of the grating, for the detection of trace amounts of aromatic hydrocarbons. The diffraction grating consisted of chromium lines on a fused silica substrate. The depth of the grating lines was 1 {micro}m, the grating period was 1 {micro}m, and the duty cycle was 50%. Since chromium was not suitable for electrochemical modulation of the analyte concentration, a 200 nm gold layer was deposited over the entire grating. This gold layer slightly degraded the transmission of the grating, but provided satisfactory optical transparency for the spectroelectrochemical experiments. The grating was configured as the working electrode in an electrochemical cell containing water plus trace amounts of the aromatic hydrocarbon analytes. The grating was then electrochemically modulated via cyclic voltammetry waveforms, and the normalized intensity of the zero order reflection was simultaneously measured. The authors discuss the lower limits of detection (LLD) for two analytes, 7-dimethylamino-1,2-benzophenoxazine (Meldola's Blue dye) and 2,4,6-trinitrotoluene (TNT), probed with an incident HeNe laser beam ({lambda} = 543.5 nm) at an incident angle of 52.5{degree}. The LLD for 7-dimethylamino-1,2-benzophenoxazine is approximately 50 parts per billion (ppb), while the LLD for TNT is approximately

  14. Characterization of aliphatic and polycyclic aromatic hydrocarbons in environmental tobacco smokes

    International Nuclear Information System (INIS)

    Mohammad Fais Fadzil; Norhayati Mohd Tahir

    2007-01-01

    A study has been conducted to investigate the distribution of aliphatic and polycyclic aromatic hydrocarbons in Environmental Tobacco Smoke (ETS). ETS is the smoke that is present in the ambient air due to smoking of tobacco. Types of cigarettes (C1R1 and C6R1) were chosen based on a result of a simple survey carried out to determine the consumer choice of cigarette brand. In analyzing the ETS, volunteers were asked to smoke each brand of cigarette in a closed room and the ETS was then collected using the high Volume Air Sampler fitted with a glass fiber filter. Smoke samples from the glass fiber filter were then extracted using Ultrasonic Agitation and fractionated into aliphatic and aromatic fraction using silica-alumina column. Identification and quantification was done using gas chromatography with flame ionization detector. Results indicated the presence of n-alkanes in ETS, ranging from C 13 to C 36 with an odd to even carbon number predominance with Carbon Preference Index(CPI) values ranging from 3.34 to 4.90. Total identified resolved aliphatic hydrocarbons (TIRAH) concentration found in ETS ranged from 590 μg m -3 to 591 μg m -3 with the percentage of plant wax n-alkanes ranging from 61% to 64% of the TIRAH found in ETS samples. In source apportionment, CPI > 1 and high percentage of plant wax n-alkanes has generally been associated with the contribution of terrestrial plant source, thus this result indicates that even after curing process and smoking of tobacco, the overall signature of the source of n-alkanes is still preserved. Amount of PAHs detected in all ETS samples ranged from 11.7 ng m -3 to 56.1 ng m -3 . Results also indicated the presence of medium to high molecular weight PAHs with dominant presence of benzo(g, h, i)perylene compound. This result seems to support the contention that smoking process involves a high temperature burning with an oxygen deficient zone in the cigarette itself. Although the concentrations were low, the

  15. Development of miniaturized submersible fluorometers for the detection of aromatic hydrocarbons in marine waters

    Science.gov (United States)

    Tedetti, Marc; Bachet, Caroline; Joffre, Pascal; Ferretto, Nicolas; Guigue, Catherine; Goutx, Madeleine

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are among the most widespread organic contaminants in aquatic environments. Due to their physico-chemical properties, PAHs are persistent and mobile, can strongly bioaccumulate in food chains and are harmful to living organisms. They are thus recognized by various international organizations as priority contaminants and are included in the list of 45 priority regulated substances by the European Union. Because of their aromatic structure, PAHs are "optically active" and have inherent fluorescence properties in the ultraviolet (UV) spectral domain (200-400 nm). Therefore, UV fluorescence spectroscopy has been successfully used to develop PAH sensors (i.e. UV fluorometers). Currently, five UV submersible fluorometers are commercially available for in situ measurements of PAHs: EnviroFlu-HC (TriOS Optical Sensors, Germany), Hydrocarbon Fluorometer (Sea & Sun Technology, Germany), HydroC ™ / PAH (CONTROS, Germany), UviLux AquaTracka (Chelsea Technology Group, UK) and Cyclops-7 (Turner Designs, US). These UV fluorometers are all dedicated to the measurement of phenanthrene (λEx /λEm: 255/360 nm), one of the most abundant and fluorescent PAHs found in the aquatic environment. In this study, we developed original, miniaturized submersible fluorometers based on deep UV light-emitting diodes (LEDs) for simultaneous measurements of two PAHs of interest: the MiniFluo-UV 1 for the detection of phenanthrene (PHE, at λEx /λEm: 255/360 nm) and naphthalene (NAP, at λEx /λEm: 270/340 nm), and the MiniFluo-UV 2 for the detection of fluorene (FLU, at λEx /λEm: 255/315 nm) and pyrene (PYR, at λEx /λEm: 270/380 nm). The MiniFluo-UV sensors have several features: measurements of two PAHs at the same time, small size (puck format, 80 x 60 mm), very low energy consumption (500 mW at 12V), LED monitoring, analog and numerical communication modes. The two MiniFluo-UV sensors were first tested in the laboratory: 1) on standard solutions of

  16. Photodegradation of polycyclic aromatic hydrocarbons in soils under a climate change base scenario.

    Science.gov (United States)

    Marquès, Montse; Mari, Montse; Audí-Miró, Carme; Sierra, Jordi; Soler, Albert; Nadal, Martí; Domingo, José L

    2016-04-01

    The photodegradation of polycyclic aromatic hydrocarbons (PAHs) in two typical Mediterranean soils, either coarse- or fine-textured, was here investigated. Soil samples, spiked with the 16 US EPA priority PAHs, were incubated in a climate chamber at stable conditions of temperature (20 °C) and light (9.6 W m(-2)) for 28 days, simulating a climate change base scenario. PAH concentrations in soils were analyzed throughout the experiment, and correlated with data obtained by means of Microtox(®) ecotoxicity test. Photodegradation was found to be dependent on exposure time, molecular weight of each hydrocarbon, and soil texture. Fine-textured soil was able to enhance sorption, being PAHs more photodegraded than in coarse-textured soil. According to the EC50 values reported by Microtox(®), a higher detoxification was observed in fine-textured soil, being correlated with the outcomes of the analytical study. Significant photodegradation rates were detected for a number of PAHs, namely phenanthrene, anthracene, benzo(a)pyrene, and indeno(123-cd)pyrene. Benzo(a)pyrene, commonly used as an indicator for PAH pollution, was completely removed after 7 days of light exposure. In addition to the PAH chemical analysis and the ecotoxicity tests, a hydrogen isotope analysis of benzo(a)pyrene was also carried out. The degradation of this specific compound was associated to a high enrichment in (2)H, obtaining a maximum δ(2)H isotopic shift of +232‰. This strong isotopic effect observed in benzo(a)pyrene suggests that compound-specific isotope analysis (CSIA) may be a powerful tool to monitor in situ degradation of PAHs. Moreover, hydrogen isotopes of benzo(a)pyrene evidenced a degradation process of unknown origin occurring in the darkness. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization.

    Science.gov (United States)

    Nowak, Jeremy A; Weber, Robert J; Goldstein, Allen H

    2018-03-12

    The ability to structurally characterize and isomerically quantify crude oil hydrocarbons relevant to refined fuels such as motor oil, diesel, and gasoline represents an extreme challenge for chromatographic and mass spectrometric techniques. This work incorporates two-dimensional gas chromatography coupled to a tunable vacuum ultraviolet soft photoionization source, the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source at the Lawrence Berkeley National Laboratory, with a time-of-flight mass spectrometer (GC × GC-VUV-TOF) to directly characterize and isomerically sum the contributions of aromatic and aliphatic species to hydrocarbon classes of four crude oils. When the VUV beam is tuned to 10.5 ± 0.2 eV, both aromatic and aliphatic crude oil hydrocarbons are ionized to reveal the complete chemical abundance of C 9 -C 30 hydrocarbons. When the VUV beam is tuned to 9.0 ± 0.2 eV only aromatic hydrocarbons are ionized, allowing separation of the aliphatic and aromatic fractions of the crude oil hydrocarbon chemical classes in an efficient manner while maintaining isomeric quantification. This technique provides an effective tool to determine the isomerically summed aromatic and aliphatic hydrocarbon compositions of crude oil, providing information that goes beyond typical GC × GC separations of the most dominant hydrocarbon isomers.

  18. Decomposition of volatile organic compounds and polycyclic aromatic hydrocarbons in industrial off-gas by electron beams: A review

    International Nuclear Information System (INIS)

    Paur, H.R.

    1998-01-01

    The electron beam induced decomposition of volatile organic compounds (e.g. aromatic compounds, esters, chlorinated hydrocarbons) and polycyclic aromatic hydrocarbons (e.g. chlorinated dibenzo-dioxins) in industrial off gas has been investigated by several research groups in Germany and Japan. The method was shown to be effective for cleaning the waste gas of a paint factory, the waste air discharged from an automobile tunnel, the off gas cleaning from a groundwater remediation plant and the flue gas of a waste incinerator. The electron beam process achieves high removal efficiencies for volatile organic compounds. Reaction models have been developed, which suggest that the organic compounds are oxidized by hydroxyl radicals. The electron beam process may treat very large off-gas volumes at ambient temperatures and has a low energy consumption. The production of secondary wastes can be avoided or minimized. Compared to conventional methods the investment and operation costs of the process seem to be attractive for selected applications

  19. Concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and Major and Trace Elements in Simulated Rainfall Runoff from Parking Lots, Austin, Texas, 2003

    National Research Council Canada - National Science Library

    Mahler, Barbara J; Van Metre, Peter C; Wilson, Jennifer T

    2004-01-01

    Samples of creek bed sediment collected near seal-coated parking lots in Austin, Texas, by the City of Austin during 2001-02 had unusually elevated concentrations of polycyclic aromatic hydrocarbons (PAHs...

  20. Biological monitoring the exposure to polycyclic aromatic hydrocarbons of coke oven workers in relation to smoking and genetic polymorphisms for GSTM1 GSTT1

    NARCIS (Netherlands)

    Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Asten, J.G. van; Vogel, N. de; Bruijntjes-Rozier, T.C.D.M.; Schouten, T.; Cramers, P.; Maas, L.; Herwijnen, M.H. van; Schooten, F.-J. van; Hopmans, P.M.J.

    2001-01-01

    Occupational exposure to polycyclic aromatic hydrocarbons (PAH) increases the risk of developing lung cancer. Human exposure is often demonstrated by increased internal levels of PAH metabolites and of markers for early biological effects, like DNA adducts and cytogenetic aberrations. Objective:

  1. RELATING DAILY SOLAR ULTRAVIOLET RADIATION DOSE IN SALT MARSH-ASSOCIATED ESTUARINE SYSTEMS TO LABORATORY ASSESSMENTS OF PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY

    Science.gov (United States)

    Estuaries of the southeastern United States not only serve an important nursery function but also are common repositories of polycyclic aromatic hydrocarbons (PAHs) derived from upland activities. Thus, these habitats may be at risk for PAHphototoxicity. To better characterize ...

  2. The Influence of Multiwalled Carbon Nanotubes on Polycyclic Aromatic Hydrocarbon (PAH) Bioavailability and Toxicity to Soil Microbial Communities in Alfalfa Rhizosphere

    Science.gov (United States)

    Carbon nanotubes (CNTs) may affect bioavailability and toxicity of organic contaminants due to their adsorption properties. Recent studies have observed the influence of multiwalled carbon nanotubes (MWNTs) on the fate of polycyclic aromatic hydrocarbons (PAHs) and other organic contaminants. Greenh...

  3. Webinar Presentation: Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes

    Science.gov (United States)

    This presentation, Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes, was given at the NIEHS/EPA Children's Centers 2016 Webinar Series: Childhood Obesity

  4. Functional soil metagenomics: elucidation of polycyclic aromatic hydrocarbon degradation potential following 12 years of in situ bioremediation.

    Science.gov (United States)

    Duarte, Márcia; Nielsen, Agnes; Camarinha-Silva, Amélia; Vilchez-Vargas, Ramiro; Bruls, Thomas; Wos-Oxley, Melissa L; Jauregui, Ruy; Pieper, Dietmar H

    2017-08-01

    A culture-independent function-based screening approach was used to assess the microbial aerobic catabolome for polycyclic aromatic hydrocarbons degradation of a soil subjected to 12 years of in situ bioremediation. A total of 422 750 fosmid clones were screened for key aromatic ring-cleavage activities using 2,3-dihydroxybiphenyl as substrate. Most of the genes encoding ring-cleavage enzymes on the 768 retrieved positive fosmids could not be identified using primer-based approaches and, thus, 205 fosmid inserts were sequenced. Nearly two hundred extradiol dioxygenase encoding genes of three different superfamilies could be identified. Additional key genes of aromatic metabolic pathways were identified, including a high abundance of Rieske non-heme iron oxygenases that provided detailed information on enzymes activating aromatic compounds and enzymes involved in activation of the side chain of methylsubstituted aromatics. The gained insights indicated a complex microbial network acting at the site under study, which comprises organisms similar to recently identified Immundisolibacter cernigliae TR3.2 and Rugosibacter aromaticivorans Ca6 and underlined the great potential of an approach that combines an activity-screening, a cost-effective high-throughput sequencing of fosmid clones and a phylogenomic-routed and manually curated database to carefully identify key proteins dedicated to aerobic degradation of aromatic compounds. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. Polycyclic aromatic hydrocarbons degradation and microbial community shifts during co-composting of creosote-treated wood

    Czech Academy of Sciences Publication Activity Database

    Covino, Stefano; Fabiánová, Tereza; Křesinová, Zdena; Čvančarová, Monika; Burianová, Eva; Filipová, Alena; Voříšková, Jana; Baldrian, Petr; Cajthaml, Tomáš

    2016-01-01

    Roč. 301, JAN 15 (2016), s. 17-26 ISSN 0304-3894 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA TA ČR TE01020218; GA ČR GA13-28283S Institutional support: RVO:61388971 Keywords : Composting * Bioremediation * Polycyclic aromatic hydrocarbons Subject RIV: EE - Microbiology, Virology Impact factor: 6.065, year: 2016

  6. Determination of Polycyclic Aromatic Hydrocarbons in Automobile Exhaust by Means of High-Performance Liquid Chromatography with Fluorescence Detection

    DEFF Research Database (Denmark)

    Nielsen, Tom

    1979-01-01

    A chromatographic method has been developed and applied to the determination of polycyclic aromatic hydrocarbons (PAHs) in particulate matter in automobile exhaust, in petrols, and in crankcase oils. The PAHs were purified from other organic compounds by thin-layer chromatography, separated by high......-performance liquid chromatography, and measured by means of on-line fluorescence detection. The identities of the PAHs were verified by comparing the emission spectra obtained by a stop-flow technique with those of standard PAHs...

  7. Biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the Middle Atlantic Ridge

    OpenAIRE

    Cui, Zhisong; Lai, Qiliang; Dong, Chunming; Shao, Zongze

    2008-01-01

    The bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched w...

  8. Polycyclic aromatic hydrocarbons modulate cell proliferation in rat hepatic epithelial stem-like WB-F344 cells

    Czech Academy of Sciences Publication Activity Database

    Chramostová, Kateřina; Vondráček, Jan; Šindlerová, Lenka; Vojtěšek, B.; Kozubík, Alois; Machala, M.

    2004-01-01

    Roč. 196, č. 1 (2004), s. 136-148 ISSN 0041-008X R&D Projects: GA ČR GP525/01/D076; GA ČR GA525/03/1527 Institutional research plan: CEZ:AV0Z5004920 Keywords : polycyclic aromatic hydrocarbons * contact inhibition * rat liver epithelial cells Subject RIV: BO - Biophysics Impact factor: 2.618, year: 2004

  9. Synthesis of zirconia-immobilized copper chelates for catalytic decomposition of hydrogen peroxide and the oxidation of polycyclic aromatic hydrocarbons

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Merhautová, Věra; Cajthaml, Tomáš; Nerud, František; Stopka, Pavel; Gorbacheva, O.; Hrubý, Martin; Beneš, Milan J.

    2008-01-01

    Roč. 72, č. 11 (2008), s. 1721-1726 ISSN 0045-6535 R&D Projects: GA AV ČR IBS5020306 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z40320502; CEZ:AV0Z40500505 Keywords : degradation * polycyclic aromatic hydrocarbons * hydrogen peroxide Subject RIV: EE - Microbiology, Virology Impact factor: 3.054, year: 2008

  10. Electron Correlations and Two-Photon States in Polycyclic Aromatic Hydrocarbon Molecules: A Peculiar Role of Geometry

    OpenAIRE

    Aryanpour, K.; Shukla, A.; Mazumdar, S.

    2013-01-01

    We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene and circumcoronene, all possessing $D_{6h}$ point group symmetry versus ovalene with $D_{2h}$ symmetry, within the Pariser-Parr-Pople model of interacting $\\pi$-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitat...

  11. Polycyclic aromatic hydrocarbons (PAHs) in meat products and estimated PAH intake by children and general population in Estonia

    OpenAIRE

    2007-01-01

    Abstract The concentrations of benzo(a)pyrene and 11 other polycyclic aromatic hydrocarbons (PAHs) were analysed from 322 commercial cured meat products and 14 home-grilled meat samples as part of the Estonian food safety monitoring programme during 2001-2005. The maximum acceptable concentration of 5 ?g kg-1 for benzo(a)pyrene was exceeded in 3.4% of analyzed samples. Highest PAH concentrations were detected in home-grilled pork samples. Using of disposable grilling unit resulted ...

  12. Marine organic pollutants of the Eastern Aegean: aliphatic and polycyclic aromatic hydrocarbons in Candarli Gulf surficial sediments.

    Science.gov (United States)

    Kucuksezgin, Filiz; Pazi, Idil; Gonul, L Tolga

    2012-11-01

    Aliphatics and PAHs were determined in sediments from the Candarli Gulf in 2009. Aliphatics ranged from 3.88 to 24.7 μg g(-1) while aromatics varied between hydrocarbon contamination is via oil and its products. PAH levels at all sites were below the ERL and ERM except fluorene. The results indicated that the sediments should have no potential biological impact except stations 6 and 14. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Particle-associated polycyclic aromatic hydrocarbons in a suburban region of Rio de Janeiro, Brazil, with industrial and traffic emissions

    OpenAIRE

    Marques,Larissa F. C. S.; Arbilla,Graciela; Quiterio,Simone L.; Machado,Mauro Cesar S.

    2009-01-01

    From April 206 to March 2007, total suspended particles (TSP) and PM10 samples were collected at the Campus of FIOCRUZ, situated in a suburban region with intense industrial and commercial activities in Rio de Janeiro (Brazil). The concentrations of 16 selected polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography with mass selective detection. Individual concentrations were between the detection limit (acenaphtylene, acenaphthene, anthracene and fluorene) and 6.16 ng ...

  14. Exploring the relationship between polycyclic aromatic hydrocarbons and sedimentary organic carbon in three Chinese lakes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fengchang; Xu, Libin; Liao, Haiqing; Zhao, Xiaoli [Chinese Research Academy of Environmental Sciences, Beijing (China). State Key Lab. of Environmental Criteria and Risk Assessment; Sun, Yongge [Zhejiang Univ., Hangzhou (China). Inst. of Environmental and Biogeochemistry; Guo, Jianyang [Chinese Academy of Sciences, Guiyang (China). State Key Lab. of Environmental Geochemistry

    2012-05-15

    Purpose: Previous studies have shown a positive correlation between concentrations of polycyclic aromatic hydrocarbons (PAHs) and total organic carbon (TOC) in lake sediments. However, with respect to the complex organic matter in recent sediments, it is still unclear which part of TOC plays a key role in controlling PAHs distributions in natural sediments. The aim of this study was to examine the relationships between PAHs and TOC components of different origins in lake sediments. Materials and methods: Sediment cores from three Chinese lakes with different trophic conditions - Lakes Bosten, Dianchi, and Poyang - were collected using a piston core sampler. The cores were sectioned into 1- or 2-cm intervals immediately after collection and transported on ice to the laboratory where they were stored at -20 C. The subsamples were freeze-dried and ground with a mortar and pestle for analyses. PAHs were analyzed by GC-MS and TOC was determined with a PE elemental analyzer after the removal of carbonates. Rock-Eval 6 pyrolysis technique was used to deconvolute the TOC in the sediments into free and volatile hydrocarbons (S1), kerogen-derived hydrocarbons (S2), and residual carbon (RC); S2 was further separated into thermal less stable macromolecular organic matter (S2a) and high molecular weight kerogens (S2b). Results and discussion: Positive correlations between TOC and PAHs were observed in these lakes. Results show that the more labile, minor components of TOC (S1 and S2a) played a more important role in controlling PAH distributions than the major components of TOC (S2b and RC), probably due to the different accessibilities of the organic components. The algae-derived organic carbon had a greater influence on the distribution of low molecular weight PAHs than that of high molecular weight PAHs in sediments. This suggests that PAHs scavenging in the water column by algae is mainly targeted at low molecular weight PAHs, and that preferential scavenging of low

  15. Carcinogenic polycyclic aromatic hydrocarbons in umbilical cord blood of human neonates from Guiyu, China

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yongyong; Huo, Xia [Analytic Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou (China); Wu, Kusheng [Analytic Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou (China); Department of Preventive Medicine, Shantou University Medical College, Shantou (China); Liu, Junxiao; Zhang, Yuling [Analytic Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou (China); Xu, Xijin, E-mail: xuxj@stu.edu.cn [Analytic Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou (China); Department of Cell Biology and Genetics, Shantou University Medical College, Shantou (China)

    2012-06-15

    Unregulated electronic-waste recycling results in serious environmental pollution of polycyclic aromatic hydrocarbons (PAHs) in Guiyu, China. We evaluated the body burden of seven carcinogenic PAHs and potential health risks for neonates. Umbilical cord blood (UCB) samples were collected from Guiyu (n = 103), and the control area of Chaonan (n = 80), China. PAHs in UCB were determined by gas chromatography/mass spectrometry. The median N-Ary-Summation 7c-PAH concentration was 108.05 ppb in UCB samples from Guiyu, vs. 79.36 ppb in samples from Chaonan. Residence in Guiyu and longer cooking time of food during the gestation period were significant factors contributing to the N-Ary-Summation 7c-PAH level. Benzo[a]anthracene (BaA), chrysene (Chr), and benzo[a]pyrene (BaP) were found to correlate with reduced neonatal height and gestational age. Infants experiencing adverse birth outcomes, on the whole, displayed higher BaA, Chr, and BaP levels compared to those with normal outcomes. We conclude that maternal PAH exposure results in fetal accumulation of toxic PAHs, and that such prenatal exposure correlates with adverse effects on neonatal health.

  16. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in soils of Mayabeque, Cuba.

    Science.gov (United States)

    Sosa, Dayana; Hilber, Isabel; Faure, Roberto; Bartolomé, Nora; Fonseca, Osvaldo; Keller, Armin; Schwab, Peter; Escobar, Arturo; Bucheli, Thomas D

    2017-05-01

    Cuba is a country in transition with a considerable potential for economic growth. Soils are recipients and integrators of chemical pollution, a frequent negative side effect of increasing industrial activities. Therefore, we established a soil monitoring network to monitor polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in soils of Mayabeque, a Cuban province southeast of Havana. Concentrations of the sum of the 16 US EPA PAHs and of the seven IRMM PCBs in soils from 39 locations ranged from 20 to 106 μg kg -1 and from 1.1 to 7.6 μg kg -1 , respectively. While such concentrations can be considered as low overall, they were in several cases correlated with the distance of sampling sites to presumed major emission sources, with some of the concomitantly investigated source diagnostic PAH ratios, and with black carbon content. The presented data adds to the limited information on soil pollution in the Caribbean region and serves as a reference time point before the onset of a possible further industrial development in Cuba. It also forms the basis to set up and adapt national environmental standards.

  17. Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Verdin, Anthony [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France); Lounes-Hadj Sahraoui, Anissa [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)]. E-mail: lounes@univ-littoral.fr; Newsam, Ray [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Robinson, Gary [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Durand, Roger [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)

    2005-01-01

    Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities.

  18. [Occurrence and spatial differentiation of polycyclic aromatic hydrocarbons in surface soils from Shenzhen, China].

    Science.gov (United States)

    Zhang, Di; Cao, Shan-Ping; Sun, Jian-Lin; Zeng, Hui

    2014-02-01

    188 surface soil samples were collected in Shenzhen of China to determine the occurrence and spatial differentiation of polycyclic aromatic hydrocarbons (PAHs), based on which we studied the correlation between PAHs concentrations and urbanization levels, as well as the PAHs ecological risk. The total concentrations of 28 PAHs (sigma28 PAHs), 16 EPA PAHs (sigma 16 PAHs) and 7 carcinogenic PAHs (sigma7 CarPAHs) ranged from 5 to 7939 ng x g(-1), 2 to 6745 ng x g(-1) and not detected to 3786 ng x g(-1), respectively. 8 kinds of land use types according to sigma16 PAHs average levels in descending order were: transportation lands, commercial lands, industrial lands, agricultural lands, residential lands, urban green space, orchards and woodland. And sigma16 PAHs of construction and non-construction lands samples were mainly derived from combustion of various fossil fuels with contribution of 75.1% and 68.2%, respectively. Significant positive correlation was also found between PAHs concentrations of high molecular weight and urbanization levels. And PAHs pollution in the top soils of Shenzhen was at a low-end level of the world.

  19. Parking lot sealcoat: a major source of polycyclic aromatic hydrocarbons (PAHs) in urban and suburban environments

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.; Scoggins, Mateo; Hamilton, Pixie A.

    2005-01-01

    Collaborative studies by the City of Austin and the U. S. Geological Survey (USGS) have identified coal-tar based sealcoat—the black, shiny emulsion painted or sprayed on asphalt pavement such as parking lots—as a major and previously unrecognized source of polycyclic aromatic hydrocarbon (PAH) contamination. Several PAHs are suspected human carcinogens and are toxic to aquatic life. Studies in Austin, Texas, showed that particles in runoff from coal-tar based sealcoated parking lots had concentrations of PAHs that were about 65 times higher than concentrations in particles washed off parking lots that had not been sealcoated. Biological studies, conducted by the City of Austin in the field and in the laboratory, indicated that PAH levels in sediment contaminated with abraded sealcoat were toxic to aquatic life and were degrading aquatic communities, as indicated by loss of species and decreased numbers of organisms. Identification of this source of PAHs may help to improve future strategies for controlling these compounds in urban water bodies across the Nation where parking lot sealcoat is used.

  20. Influence of traffic conditions on polycyclic aromatic hydrocarbon abundance in street dust.

    Science.gov (United States)

    Xiang, Li; Li, Yingxia; Yang, Zhifeng; Shi, Jianghong

    2010-01-01

    Polycyclic aromatic hydrocarbon (PAH) concentrations were quantified in sieved street dusts from eight sampling sites with different traffic conditions in Beijing. The parent diagnostic ratio test and multi-regression analysis were used to identify the different PAH pollution sources. Results showed that more than 93% of the cumulative 16 priority pollutant PAHs (Sigma 16EPA-PAH) load was present in street dust with a diameter less than 300 microm across all the sampling sites. The concentration of Sigma 4-6 ring PAHs was 93 to 284% higher than that of Sigma 2-3 ring PAHs for most of the sites except the cycle lane site, indicating the dominance of pyrogenic inputs in street dusts at these sites. Cooking oil is an important PAH source in street dusts for all the sampling sites. Tire debris and vehicle emissions were also identified as significant contributors to the PAH loading in the heavy traffic zone, vehicle parking areas, the frequent brake usage zone, and the construction area.

  1. Heavy metals and polycyclic aromatic hydrocarbons: pollution and ecological risk assessment in street dust of Tehran.

    Science.gov (United States)

    Saeedi, Mohsen; Li, Loretta Y; Salmanzadeh, Mahdiyeh

    2012-08-15

    50 street dust samples from four major streets in eastern and southern Tehran, the capital of Iran, were analyzed for metal pollution (Cu, Cr, Pb, Ni, Cd, Zn, Fe, Mn and Li). Hakanson's method was used to determine the Risk Index (RI) and ecological risks. Amongst these samples, 21 were also analyzed for polycyclic aromatic hydrocarbons (PAHs). Correlation, cluster and principal component analyses identified probable natural and anthropogenic sources of contaminants. The dust had elevated concentrations of Pb, Cd, Cu, Cr, Ni, Zn, Fe and PAHs. Enrichment factors of Cu, Pb, Cd and Zn showed that the dust is extremely enriched in these metals. Multivariate statistical analyses revealed that Cu, Pb, Zn, Fe and PAHs and, to a lesser extent, Cr and Ni have common anthropogenic sources. While Mn and Li were identified to have natural sources, Cd may have different anthropogenic origins. All samples demonstrated high ecological risk. Traffic and related activities, petrogenic and pyrogenic sources are likely to be the main anthropogenic sources of heavy metals and PAHs in Tehran dust. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Polycyclic aromatic hydrocarbons in urban street dust: sources and health risk assessment.

    Science.gov (United States)

    Wang, Xue Song

    2018-02-01

    Urban street dust samples from 49 sampling sites in Xuzhou (China) were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) using gas chromatography/mass spectrometry. The organic matter and total carbon contents were also determined. The results showed that total PAHs concentrations varied from 2174 to 24,499 ng/g with a mean value of 6616 ng/g, organic matter content varied from 3.1 to 8.7% with a mean value of 5.8%, total carbon content varied from 13.2 to 24.2%, with a mean value of 19.9%. Total carbon content was found to show a significant correlation with total PAHs concentration, but such a relationship with total PAHs concentration was only weakly identified for organic matter content. Source Apportionment Techniques indicated pyrogenic sources were the main source of PAHs in urban street dust. The total incremental lifetime cancer risk, including dermal contact, ingestion and inhalation exposure pathways, was estimated to be 4.12 × 10 -6 and 3.98 × 10 -6 for children and adults, respectively.

  3. Modelling Poly-Aromatic Hydrocarbons "online" with the GEOS-Chem Europe and Asia regional models.

    Science.gov (United States)

    Ivatt, P.; Evans, M. J.

    2017-12-01

    Poly-Aromatic Hydrocarbons (PAHs) are carcinogens and so are restricted by international treaties. PAHs are mainly emitted into the atmosphere by domestic (heating and cooking), natural (forest fires burning), as well as some industrial processes (coke ovens). PAHs partition between the gas and particle phase (notably carbonaceous particles) based on their volatility. In recent years, interest has turned to the possible health effects of their oxidation products (both nitrogenated and oxygenated) as it has been suggested that these oxidation products may be even more carcinogenic than the parent PAHs. To increase our understanding of the processes controlling the regional concentrations of PAHs and their oxidation products an "online" PAH model has been developed within the GEOS-Chem framework. This provides for the representation of the coupled aerosol/gas phase chemistry of the parent PAH and its secondary oxidation products. Benzo[a]pyrene is used as an exemplar but the methodology is flexible and the approach can be used for any PAH species. Comparisons are made with observations and the sources of variability discussed.

  4. Impact of soil organic matter on the distribution of polycyclic aromatic hydrocarbons (PAHs) in soils

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Zhang, N.; Xue, M. [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Tao, S., E-mail: taos@urban.pku.edu.c [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2010-06-15

    The knowledge on the distribution of hydrophobic organic contaminants in soils can provide better understanding for their fate in the environment. In the present study, the n-butanol extraction and humic fractionation were applied to investigate the impact of SOM on the distribution of polycyclic aromatic hydrocarbons (PAHs). The results indicated that 80.5%-94.8% of the target PAHs could be extracted by n-butanol and 63.1%-94.6% of PAHs were associated with fulvic acid (FA). Concentrations of un-extracted PAHs increased significantly with the increasing soil organic matter (SOM), however, such an association was absent for the extractable fractions. The results suggested that the sequestration played a critical role in the accumulation of PAHs in soils. SOM also retarded the diffusion of PAHs into the humin fractions. It implied that sequestration in SOM was critical for PAH distribution in soils, while the properties of PAH compounds also had great influences. - Soil organic matter played an important role in the distribution of PAHs in soils through sequestration.

  5. Assessing the polycyclic aromatic hydrocarbon anisotropic potential with application to the exfoliation energy of graphite.

    Science.gov (United States)

    Totton, Tim S; Misquitta, Alston J; Kraft, Markus

    2011-11-24

    In this work we assess a recently published anisotropic potential for polycyclic aromatic hydrocarbon (PAH) molecules (J. Chem. Theory Comput. 2010, 6, 683-695). Comparison to recent high-level symmetry-adapted perturbation theory based on density functional theory (SAPT(DFT)) results for coronene (C(24)H(12)) demonstrate the transferability of the potential while highlighting some limitations with simple point charge descriptions of the electrostatic interaction. The potential is also shown to reproduce second virial coefficients of benzene (C(6)H(6)) with high accuracy, and this is enhanced by using a distributed multipole model for the electrostatic interaction. The graphene dimer interaction energy and the exfoliation energy of graphite have been estimated by extrapolation of PAH interaction energies. The contribution of nonlocal fluctuations in the π electron density in graphite have also been estimated which increases the exfoliation energy by 3.0 meV atom(-1) to 47.6 meV atom(-1), which compares well to recent theoretical and experimental results.

  6. POLYCYCLIC AROMATIC HYDROCARBONS CONCENTRATION AND MUTAGENIC EFFECTS OF DUST IN OUTDOOR ENVIRONMENT IN SILESIAN REGION

    Directory of Open Access Journals (Sweden)

    Agnieszka Kozłowska

    2011-09-01

    Full Text Available Quality and quantity of pollution depend on the combusted fuels and industrial technologies, the season of the year and meteorological conditions. Dust pollution of the air consists of diverse chemical organic and inorganic substances. Polycyclic aromatic hydrocarbon (PAH mixture and their nitric, amin, oxidated and chlorated derivatives, which are found in all dust fractions, are particularly dangerous to human health and exert mutagenic effects. PAHs are measured and analyzed using liquid chromatography, which is one of the most popular technique in analytical chemistry. Standard Ames test on Salmonella strain TA98 and YG1041 was used to assess mutagenic properties of dust. Samples of dust were collected on glass fiber filters by aspiration instrument with air flow 1 m3/min. during the autumn in six cities in Silesian Region. Extraction of pollution was carried out in Soxhlet instrument using dichlorometane in the ventilated chamber. There was majority of indirect mutagenic substances (requiring metabolic activation in studied samples. Mutagenic activity of dust fractions in outdoor air was caused by the PAHs concentrations, and particularly by benzo(apyrene, what was confirmed by HPLC.

  7. Contamination and distribution of parent, nitrated, and oxygenated polycyclic aromatic hydrocarbons in smoked meat.

    Science.gov (United States)

    Chen, Yuanchen; Shen, Guofeng; Su, Shu; Shen, Huizhong; Huang, Ye; Li, Tongchao; Li, Wei; Zhang, Yanyan; Lu, Yan; Chen, Han; Yang, Chunli; Lin, Nan; Zhu, Ying; Fu, Xiaofang; Liu, Wenxin; Wang, Xilong; Tao, Shu

    2014-10-01

    Smoked meat is widely consumed in many areas, particularly in rural southwest China. High concentrations of polycyclic aromatic hydrocarbons (PAHs) in smoked meat could lead to adverse dietary exposure and health risks. In this study, 27 parent PAHs (pPAHs), 12 nitrated PAHs (nPAHs), and 4 oxygenated PAHs (oPAHs) were measured in coal- and wood-smoked meats. The median concentrations of pPAHs, nPAHs, and oPAHs were as high as 1.66 × 10(3), 4.29, and 20.5 ng/g in the coal-smoked meat and 2.54 × 10(3), 7.32, and 9.26 ng/g in the wood-smoked meat, respectively. Based on the relative potency factors of individual PAHs, the calculated toxic equivalent (TEQ) values of all pPAHs were 22.1 and 75.1 ng TEQ/g for the wood- and coal-smoked meats, respectively. The highest concentrations of PAHs can be found in the surface layer of skin and decrease exponentially with depth. Surface PAH concentrations correlated with concentrations of PAHs in household air and with the concentration in emission exhaust. Migration of PAHs from surface to interior portions of meat is faster in lean than in fat or skin, and oPAHs and pPAHs can penetrate deeper than pPAHs. The penetration ability of PAHs is negatively correlated with the molecular weight.

  8. Using quantitative structure-activity relationships (QSAR) to predict toxic endpoints for polycyclic aromatic hydrocarbons (PAH).

    Science.gov (United States)

    Bruce, Erica D; Autenrieth, Robin L; Burghardt, Robert C; Donnelly, K C; McDonald, Thomas J

    2008-01-01

    Quantitative structure-activity relationships (QSAR) offer a reliable, cost-effective alternative to the time, money, and animal lives necessary to determine chemical toxicity by traditional methods. Additionally, humans are exposed to tens of thousands of chemicals in their lifetimes, necessitating the determination of chemical toxicity and screening for those posing the greatest risk to human health. This study developed models to predict toxic endpoints for three bioassays specific to several stages of carcinogenesis. The ethoxyresorufin O-deethylase assay (EROD), the Salmonella/microsome assay, and a gap junction intercellular communication (GJIC) assay were chosen for their ability to measure toxic endpoints specific to activation-, induction-, and promotion-related effects of polycyclic aromatic hydrocarbons (PAH). Shape-electronic, spatial, information content, and topological descriptors proved to be important descriptors in predicting the toxicity of PAH in these bioassays. Bioassay-based toxic equivalency factors (TEF(B)) were developed for several PAH using the quantitative structure-toxicity relationships (QSTR) developed. Predicting toxicity for a specific PAH compound, such as a bioassay-based potential potency (PP(B)) or a TEF(B), is possible by combining the predicted behavior from the QSTR models. These toxicity estimates may then be incorporated into a risk assessment for compounds that lack toxicity data. Accurate toxicity predictions are made by examining each type of endpoint important to the process of carcinogenicity, and a clearer understanding between composition and toxicity can be obtained.

  9. Polycyclic aromatic hydrocarbons bioaccessibility in seafood: Culinary practices effects on dietary exposure.

    Science.gov (United States)

    Dos Santos Fogaça, Fabíola Helena; Soares, Cristina; Oliveira, Marta; Alves, Ricardo N; Maulvault, Ana L; Barbosa, Vera L; Anacleto, Patrícia; Magalhães, João Avelar; Bandarra, Narcisa M; Ramalhosa, Maria João; Morais, Simone; Marques, António

    2018-07-01

    This work aimed to determine the effect of culinary practices on the contamination level and bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in seafood. The selected farmed seafood species (marine shrimp, clams and seaweed) were commercially available in Portugal. The mean concentrations of PAHs varied between 0.23 and 51.8 µg kg -1 , with the lowest value being observed in raw shrimp and the highest in dried seaweed. The number of compounds detected in seaweed and clams (naphthalene, acenaphthene, fluorene, phenanthrene, benzo(b)fluoranthene and benzo(j)fluoranthene) were higher than in shrimp (fluorene and pyrene). Among the PAHs measured, fluorene was the predominant one. There was a significant interaction effect between species and culinary treatment (p < 0.05), thus boiled and dried seaweed samples presented the lowest and the highest levels of fluorene (0.13 and 1.8 µg kg -1 ), respectively. The daily intake of PAHs decreased with bioaccessibility, varying from 22% for benzo(k)fluoranthene (in raw clam) to 84% for phenanthrene (in steamed clam). According to the potency equivalent concentrations, screening values and bioaccessibility of PAHs, the consumption of marine shrimp, clam and seaweed is considered as safe for consumers. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Assessing Photoinduced Toxicity of Polycyclic Aromatic Hydrocarbons in an Urbanized Estuary

    Directory of Open Access Journals (Sweden)

    M. Vo

    2004-12-01

    Full Text Available Increases in contaminants associated with urban sprawl are a particular concern in the rapidly developing coastal areas of the southeastern United States. Polycyclic aromatic hydrocarbons (PAHs are contaminants associated with vehicle emissions and runoff from impervious surfaces. Increased vehicular traffic and more impervious surfaces lead to an increased loading of PAHs into coastal estuarine systems. The phototoxic effect of PAH-contaminated sediments on a sediment-dwelling meiobenthic copepod, Amphiascus tenuiremis, was estimated in Murrells Inlet, a small, high-salinity estuary with moderate urbanization located in Georgetown and Horry Counties, South Carolina, USA. Field-determined solar ultraviolet radiation (UV and UV extinction coefficients were incorporated into laboratory toxicity experiments, and a model was developed to predict areas of specific hazard to A. tenuiremis in the estuary. The model incorporated laboratory toxicity data, UV extinction coefficients, and historical sediment chemistry and bathymetric data within a spatial model of sedimentary areas of the estuary. The model predicted that approximately 8-16% of the total creek habitat suitable for meiobenthic copepods is at risk to photoinduced PAH toxicity. This area is in the northern, more developed part of Murrells Inlet.

  11. Potential of Polycyclic Aromatic Hydrocarbon-Degrading Bacterial Isolates to Contribute to Soil Fertility.

    Science.gov (United States)

    Bello-Akinosho, Maryam; Makofane, Rosina; Adeleke, Rasheed; Thantsha, Mapitsi; Pillay, Michael; Chirima, George Johannes

    2016-01-01

    Restoration of polycyclic aromatic hydrocarbon- (PAH-) polluted sites is presently a major challenge in agroforestry. Consequently, microorganisms with PAH-degradation ability and soil fertility improvement attributes are sought after in order to achieve sustainable remediation of polluted sites. This study isolated PAH-degrading bacteria from enriched cultures of spent automobile engine-oil polluted soil. Isolates' partial 16S rRNA genes were sequenced and taxonomically classified. Isolates were further screened for their soil fertility attributes such as phosphate solubilization, atmospheric nitrogen fixation, and indoleacetic acid (IAA) production. A total of 44 isolates were obtained and belong to the genera Acinetobacter , Arthrobacter , Bacillus , Flavobacterium , Microbacterium , Ochrobactrum , Pseudomonas , Pseudoxanthomonas , Rhodococcus , and Stenotrophomonas . Data analysed by principal component analysis showed the Bacillus and Ochrobactrum isolates displayed outstanding IAA production. Generalized linear modelling statistical approaches were applied to evaluate the contribution of the four most represented genera ( Pseudomonas , Acinetobacter , Arthrobacter , and Rhodococcus ) to soil fertility. The Pseudomonas isolates were the most promising in all three soil fertility enhancement traits evaluated and all isolates showed potential for one or more of the attributes evaluated. These findings demonstrate a clear potential of the isolates to participate in restorative bioremediation of polluted soil, which will enhance sustainable agricultural production and environmental protection.

  12. Measurement of polynuclear aromatic hydrocarbon concentrations in the plume of Kuwait oil well fires

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, K.B.; Wright, C.W.; Veverka, C. [Pacific Northwest Lab., Richland, WA (United States); Ball, J.C. [Ford Motor Co., Dearborn, MI (United States). Scientific Research Lab.; Stevens, R. [US Environmental Protection Agency (United States). Atmospheric Research and Exposure Assessment Lab.

    1995-03-01

    Following their retreat from Kuwait during February and March of 1991, the Iraqi Army set fire to over 500 oil wells dispersed throughout the Kuwait oil fields. During the period of sampling from July to August 1991, it was estimated that between 3.29 {times} 10{sup 6} barrels per day of crude oil were combusted. The resulting fires produced several plumes of black and white smoke that coalesced to form a composite ``super`` plume. Because these fires were uncontrolled, significant quantities of organic materials were dispersed into the atmosphere and drifted throughout the Middle East. The organic particulants associated with the plume of the oil well fires had a potential to be rich in polynuclear aromatic hydrocarbon (PAH) compounds. Based on the extreme mutagenic and carcinogenic activities of PAHs found in laboratory testing, a serious health threat to the population of that region potentially existed. Furthermore, the Kuwait oil fire plumes represented a unique opportunity to study the atmospheric chemistry associated with PAHs in the plume. If samples were collected near the plume source and from the plume many kilometers downwind from the source, comparisons could be made to better understand atmospheric reactions associated with particle-bound and gas-phase PAHs. To help answer health-related concerns and to better understand the fate and transport of PAHs in an atmospheric environment, a sampling and analysis program was developed.

  13. Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment

    International Nuclear Information System (INIS)

    Mishra, Nitika; Ayoko, Godwin A.; Morawska, Lidia

    2016-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis – Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. - Highlights: • PAHs represent a major group of outdoor air pollutants. • Concentration levels of PAHS in urban schools ranged from 1.2 to 38 ng/m 3 . • PCA–APCS technique used to identify sources of PAHs and their contributions. • Vehicular emissions (56%) were found to be the prominent sources of PAHs.

  14. Quantitative Analysis of Polycyclic Aromatic Hydrocarbons (PAHs Cited by the United States Food and Drug Administration

    Directory of Open Access Journals (Sweden)

    Guthery W

    2014-12-01

    Full Text Available The yields of 16 polycyclic aromatic hydrocarbons (PAHs were determined from cigarette mainstream smoke condensate extracts using Gas Chromatography- Tandem Mass Spectrometry (GC-MS/MS. The method has been validated for ISO and Health Canada Intense (HCI smoking protocols. Quantifiable levels (ISO means 0.16 to 365 ng/cig; HCI means 0.33 to 1595 ng/cig; n = 30 of 15 PAHs were found in the Kentucky reference cigarette K3R4F. The coefficient of variance (CV was derived from ten determinations each run in triplicate. The CV range was 8.7% to 24.8% (ISO and 6.6% to 24.3% (HCI. The limit of detection (LOD based on empirical precision was ≤ 0.06 ng/cig (ISO and ≤ 0.20 ng/cig (HCI for all components except naphthalene (2.89 and 9.62 ng/cig, respectively. The yields from 5 unspecified branded cigarettes (Samples A-E and 2 other reference cigarettes, K1R5F and the CORESTA monitor CM7, were determined under ISO smoking conditions. The same 15 PAHs were detected as in the K3R4F; however, cigarettes with lower yields of total particulate matter (TPM were found to contain significantly less PAHs. One component was measured below the limit of quantification (LOQ in Sample E and 2 components were < LOQ in the K1R5F.

  15. Historical Profiles of Polycyclic Aromatic Hydrocarbons (PAHs) in Marine Sediment Cores from Northwest Spain.

    Science.gov (United States)

    Pérez-Fernández, Begoña; Viñas, Lucía; Bargiela, Jesica

    2016-11-01

    The northwest coast of Spain is characterized by an irregular coastline rich in marine life and with the highest mussel production in Europe. Taking this into account, the characterization of the pollution levels and the sources involved appear necessary. Not only were parent Polycyclic Aromatic Hydrocarbons (PAHs) analysed but also their alkylated homologues. In total, 35 compounds were analyzed in 5 sediment cores. Sediments were collected using a box core dredge and extracted by (Pressurized Liquid Extraction) whilst the quantification of PAHs was performed using gas chromatography coupled to mass spectrometry (GC-MS). The total concentration detected varied from 49.6 to 2489 ng g -1 dry weight (d.w.) of which parent PAHs ranged from 44.5 to 2254 ng g -1 d.w. and alkylated PAHs varied from 5.04 to 317 ng g -1 d.w. Temporal and spatial evolution were outlined and pollution sources were identified along with a possible correlation between this pollution and local history and industry. Most of the PAHs from the superficial samples have a biomass and coal combustion profile, and some specific, localized events are reflected in the total PAH concentration evolution. Moreover, the study of the deepest layers of the sampled cores provides a baseline to develop background concentration values that will help in future sediment quality assessment.

  16. Polycyclic aromatic hydrocarbons (PAHs in traditional smoked dairy products from Campania (Italy

    Directory of Open Access Journals (Sweden)

    Teresa Cirillo

    2004-06-01

    Full Text Available The smoked mozzarella and caciocavallo cheeses occupy a significant area among the traditional products in the Campania region. Smoked and non-smoked mozzarella and caciocavallo cheeses were screened for the presence of polycyclic aromatic hydrocarbons (PAHs. Total PAH concentration in non-smoked mozzarella ranged from 59.11 to 160.05 ìg kg-1 wet weight (w.w. and in that smoked from 67.49 to 399.90 ìg kg-1 w.w.
    The total PAH content in non-smoked caciocavallo was between 36.70 and 248.59 ìg kg-1 w.w.; in the smoked cheese, it varied from 72.52 to 1643.18 ìg kg-1 w.w. The benzo(apyrene (BaP values in all cheeses smoked by liquid smoke were higher than the permissible limit for BaP of 0.03 ìg kg-1 for foods aromatised with liquid smoke.

  17. Recalcitrance of polycyclic aromatic hydrocarbons in soil contributes to background pollution

    International Nuclear Information System (INIS)

    Posada-Baquero, Rosa; Ortega-Calvo, Jose-Julio

    2011-01-01

    The microbial accessibility of native phenanthrene and pyrene was determined in soils representing background scenarios for pollution by polycyclic aromatic hydrocarbons (PAHs). The soils were selected to cover a wide range of concentrations of organic matter (1.7-10.0%) and total PAHs (85-952 μg/kg). The experiments included radiorespirometry determinations of biodegradation with 14 C-labeled phenanthrene and pyrene and chemical analyses to determine the residual concentrations of the native compounds. Part of the tests relied on the spontaneous biodegradation of the chemicals by native microorganisms; another part also involved inoculation with PAH-degrading bacteria. The results showed the recalcitrance of PAHs already present in the soils. Even after extensive mineralization of the added 14 C-PAHs, the concentrations of native phenanthrene and pyrene did not significantly decrease. We suggest that aging processes operating at background concentrations may contribute to recalcitrance and, therefore, to ubiquitous pollution by PAHs in soils. - Highlights: → Background PAHs in soils are highly resistant to biodegradation. → Recalcitrance occurs even after inoculation with specialized microorganisms. → Recalcitrance is caused by a low bioaccessibility and aging. → Time (aging) seems a relevant factor causing recalcitrance. → Recalcitrance can explain ubiquitous PAH background pollution. - Background soil PAHs are highly resistant to biodegradation.

  18. The effect of humic acids on biodegradation of polycyclic aromatic hydrocarbons depends on the exposure regime

    International Nuclear Information System (INIS)

    Tejeda-Agredano, Maria-Carmen; Mayer, Philipp; Ortega-Calvo, Jose-Julio

    2014-01-01

    Binding of polycyclic aromatic hydrocarbons (PAHs) to dissolved organic matter (DOM) can reduce the freely dissolved concentration, increase apparent solubility or enhance diffusive mass transfer. To study the effects of DOM on biodegradation, we used phenanthrene and pyrene as model PAHs, soil humic acids as model DOM and a soil Mycobacterium strain as a representative degrader organism. Humic acids enhanced the biodegradation of pyrene when present as solid crystals but not when initially dissolved or provided by partitioning from a polymer. Synchronous fluorescence spectrophotometry, scintillation counting and a microscale diffusion technique were applied in order to determine the kinetics of dissolution and diffusive mass transfer of pyrene. We suggest that humic acids can enhance or inhibit biodegradation as a result of the balance of two opposite effects, namely, solubilization of the chemicals on the one hand and inhibition of cell adhesion to the pollutant source on the other. Highlights: • Humic acids can enhance the biodegradation of PAHs. • The enhancement depends on how the bacteria are exposed to PAHs. • Humic acids stimulate if PAHs are provided by dissolution form crystals. • An inhibition occurs if PAHs are provided by partitioning from a silicone. • The balance between enhanced dissolution and decreased adhesion is the cause. -- Humic acids cause opposite effects on biodegradation of PAHs depending on the exposure regime

  19. Recalcitrance of polycyclic aromatic hydrocarbons in soil contributes to background pollution

    Energy Technology Data Exchange (ETDEWEB)

    Posada-Baquero, Rosa [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain); Ortega-Calvo, Jose-Julio, E-mail: jjortega@irnase.csic.es [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain)

    2011-12-15

    The microbial accessibility of native phenanthrene and pyrene was determined in soils representing background scenarios for pollution by polycyclic aromatic hydrocarbons (PAHs). The soils were selected to cover a wide range of concentrations of organic matter (1.7-10.0%) and total PAHs (85-952 {mu}g/kg). The experiments included radiorespirometry determinations of biodegradation with {sup 14}C-labeled phenanthrene and pyrene and chemical analyses to determine the residual concentrations of the native compounds. Part of the tests relied on the spontaneous biodegradation of the chemicals by native microorganisms; another part also involved inoculation with PAH-degrading bacteria. The results showed the recalcitrance of PAHs already present in the soils. Even after extensive mineralization of the added {sup 14}C-PAHs, the concentrations of native phenanthrene and pyrene did not significantly decrease. We suggest that aging processes operating at background concentrations may contribute to recalcitrance and, therefore, to ubiquitous pollution by PAHs in soils. - Highlights: > Background PAHs in soils are highly resistant to biodegradation. > Recalcitrance occurs even after inoculation with specialized microorganisms. > Recalcitrance is caused by a low bioaccessibility and aging. > Time (aging) seems a relevant factor causing recalcitrance. > Recalcitrance can explain ubiquitous PAH background pollution. - Background soil PAHs are highly resistant to biodegradation.

  20. Occupational Exposure to Polycyclic Aromatic Hydrocarbons and Elevated Cancer Incidence in Firefighters.

    Science.gov (United States)

    Stec, Anna A; Dickens, Kathryn E; Salden, Marielle; Hewitt, Fiona E; Watts, Damian P; Houldsworth, Philip E; Martin, Francis L

    2018-02-06

    Cancer incidence appears to be higher amongst firefighters compared to the general population. Given that many cancers have an environmental component, their occupational exposure to products of carbon combustion such as polycyclic aromatic hydrocarbons (PAHs) is of concern. This is the first UK study identifying firefighters exposure to PAH carcinogens. Wipe samples were collected from skin (jaw, neck, hands), personal protective equipment of firefighters, and work environment (offices, fire stations and engines) in two UK Fire and Rescue Service Stations. Levels of 16 US Environmental Protection Agency (EPA) PAHs were quantified together with more potent carcinogens: 7,12-dimethylbenzo[a]anthracene, and 3-methylcholanthrene (3-MCA) (12 months post-initial testing). Cancer slope factors, used to estimate cancer risk, indicate a markedly elevated risk. PAH carcinogens including benzo[a]pyrene (B[a]P), 3-MCA, and 7,12-dimethylbenz[a]anthracene PAHs were determined on body surfaces (e.g., hands, throat), on PPE including helmets and clothing, and on work surfaces. The main exposure route would appear to be via skin absorption. These results suggest an urgent need to monitor exposures to firefighters in their occupational setting and conduct long-term follow-up regarding their health status.

  1. Phototoxic effects of fluoranthene, a polycyclic aromatic hydrocarbon, on bacterial species

    International Nuclear Information System (INIS)

    Tuveson, R.W.; Kagan, J.; Shaw, M.A.; Moresco, G.M.; von Behne, E.M.; Pu, H.; Bazin, M.; Santus, R.

    1987-01-01

    Fluoranthene, a non-carcinogenic polycyclic aromatic hydrocarbon, inactivates Escherichia coli cells in the presence of near-ultraviolet light (NUV; 300-400 nm). E coli cells carrying defects in the uvrA6 or katF genes are sensitized to inactivation by the simultaneous treatment with fluoranthene and NUV, suggesting that DNA is a target and that hydrogen peroxide is generated. Haemophilus influenzae transforming DNA can be inactivated by the simultaneous treatment with fluoranthene and NUV confirming DNA as a target. Using the photooxidation of imidazole and histidine as probes, fluoranthene was found to generate singlet oxygen in organic and aqueous media. In water, it participated in electron transfer reactions, reducing nitro blue tetrazolium as well as ferricytochrome C. This reduction took place both in the presence of air, where superoxide anion was formed, and under argon. Simultaneous treatment with fluoranthene and NUV was incapable of inducing histidine-independent mutations. Simultaneous treatment with fluoranthene and NUV was incapable of inducing the uvrA gene product as evidenced by the absence of the induction of beta-galactosidase in an E coli operon fusion strain [uvrA215::Mud(Ap,lac)

  2. The polycyclic aromatic hydrocarbon concentrations in soils in the Region of Valasske Mezirici, the Czech Republic

    Directory of Open Access Journals (Sweden)

    Rümmeli Mark H

    2009-12-01

    Full Text Available Abstract The polycyclic aromatic hydrocarbon (PAH contamination of urban, agricultural and forest soil samples was investigated from samples obtained in the surroundings of Valasske Mezirici. Valasske Mezirici is a town located in the north-east mountainous part of the Czech Republic, where a coal tar refinery is situated. 16 PAHs listed in the US EPA were investigated. Organic oxidizable carbon was also observed in the forest soils. The PAH concentrations ranged from 0.86-10.84 (with one anomalous value of 35.14 and 7.66-79.39 mg/kg dm in the urban/agricultural and forest soils, respectively. While the PAH levels in the urban/agricultural soils are within the range typically found in industrialized areas, the forest soils showed elevated PAH concentrations compared to other forest soils in Western and Northern Europe. The PAH concentrations and their molecular distribution ratios were studied as functions of the sample location and the meteorological history. The soils from localities at higher altitudes above sea level have the highest PAH concentrations, and the PAH concentrations decrease with increasing distance from the town.

  3. Recalcitrance of polycyclic aromatic hydrocarbons in soil contributes to background pollution.

    Science.gov (United States)

    Posada-Baquero, Rosa; Ortega-Calvo, José-Julio

    2011-12-01

    The microbial accessibility of native phenanthrene and pyrene was determined in soils representing background scenarios for pollution by polycyclic aromatic hydrocarbons (PAHs). The soils were selected to cover a wide range of concentrations of organic matter (1.7-10.0%) and total PAHs (85-952 μg/kg). The experiments included radiorespirometry determinations of biodegradation with (14)C-labeled phenanthrene and pyrene and chemical analyses to determine the residual concentrations of the native compounds. Part of the tests relied on the spontaneous biodegradation of the chemicals by native microorganisms; another part also involved inoculation with PAH-degrading bacteria. The results showed the recalcitrance of PAHs already present in the soils. Even after extensive mineralization of the added (14)C-PAHs, the concentrations of native phenanthrene and pyrene did not significantly decrease. We suggest that aging processes operating at background concentrations may contribute to recalcitrance and, therefore, to ubiquitous pollution by PAHs in soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Temperature dependence of gas-phase polycyclic aromatic hydrocarbon and organochlorine pesticide concentrations in Chicago air

    Science.gov (United States)

    Sofuoglu, Aysun; Odabasi, Mustafa; Tasdemir, Yucel; Khalili, Nasrin R.; Holsen, Thomas M.

    The temperature dependence of gas-phase atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides measured in Chicago, IL between June and October 1995 were investigated using plots of the natural logarithm of partial pressures (ln P) vs. reciprocal mean temperatures (1/ T). For the eight lowest molecular weight PAHs, temperature dependence was statistically significant (at the 95% confidence level) and temperature accounted for 23-49% of the variability in gas-phase concentrations. The relatively higher slopes for most of the PAHs suggested that volatilization from local sources and short-range transport influenced their concentrations. For pesticides, temperature dependence was statistically significant for DDD and for trans-nonachlor (at the 95% and 90% confidence levels), and was not statistically significant for the other five compounds (2-18% of the variability in their gas-phase concentrations). The relatively lower slopes for individual pesticides suggested that they have mostly non-urban and distant sources. Results of back trajectory analyses suggested that the region, southwest of Chicago, might be an important local or regional source sector for PAHs and organochlorine pesticides. No statistically significant relationship was observed between wind speed and PAH or pesticide concentrations. None of the variables (temperature, wind speed, wind direction, local and regional sources) could fully explain the variation in their concentrations measured in Chicago, therefore, this variation can be attributed to the combined effect of those factors.

  5. Detection of Polarized Infrared Emission by Polycyclic Aromatic Hydrocarbons in the MWC 1080 Nebula

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Han; Telesco, Charles M.; Pantin, Eric; Barnes, Peter [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Hoang, Thiem [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon 34055 (Korea, Republic of); Li, Aigen [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Wright, Christopher M. [School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, P.O. Box 7916, Canberra BC 2610 (Australia); Li, Dan, E-mail: hanzh0420@ufl.edu [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2017-07-20

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in astrophysical environments, as revealed by their pronounced emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m commonly ascribed to the C–H and C–C vibrational modes. Although these features have long been predicted to be polarized, previous searches for PAH polarization led to null or, at best, tentative detections. Here we report the definite detection of polarized PAH emission at 11.3 μ m in the nebula associated with the Herbig Be star MWC 1080. We measure a polarization degree of 1.9% ± 0.2%, which is unexpectedly high compared to models. This poses a challenge in the current understanding of the alignment of PAHs, which is required to polarize the PAH emission but thought to be substantially suppressed. PAH alignment with a magnetic field via a resonance paramagnetic relaxation process may account for such a high level of polarization.

  6. Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles

    International Nuclear Information System (INIS)

    Verdin, Anthony; Lounes-Hadj Sahraoui, Anissa; Newsam, Ray; Robinson, Gary; Durand, Roger

    2005-01-01

    Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities

  7. Exposure to Polycyclic Aromatic Hydrocarbons, Plasma Cytokines, and Heart Rate Variability

    Science.gov (United States)

    Yang, Binyao; Deng, Qifei; Zhang, Wangzhen; Feng, Yingying; Dai, Xiayun; Feng, Wei; He, Xiaosheng; Huang, Suli; Zhang, Xiao; Li, Xiaohai; Lin, Dafeng; He, Meian; Guo, Huan; Sun, Huizhen; Yuan, Jing; Lu, Jiachun; Hu, Frank B.; Zhang, Xiaomin; Wu, Tangchun

    2016-01-01

    Epidemiological studies have suggested associations between polycyclic aromatic hydrocarbons (PAHs) and heart rate variability (HRV). However, the roles of plasma cytokines in these associations are limited. In discovery stage of this study, we used Human Cytokine Antibody Arrays to examine differences in the concentrations of 280 plasma cytokines between 8 coke-oven workers and 16 community residents. We identified 19 cytokines with significant different expression (fold change ≥2 or ≤−2, and q-value coke-oven workers by enzyme-linked immunosorbent assays in validation stage. We found OH-PAHs were inversely associated with brain-derived neurotrophic factor (BDNF) (p 16% BDNF decreases. Additionally, OH-PAHs were positively associated with activated leukocyte cell adhesion molecule (ALCAM) and C-reactive protein (CRP) (p 20% increases in CRP. We also found significant associations between these cytokines and HRV (p 8% decreases in HRV. Our results indicated PAH exposure was associated with plasma cytokines, and higher cytokines were associated with decreased HRV, but additional human and potential mechanistic studies are needed. PMID:26758679

  8. Human Health Risk Assessment of 16 Priority Polycyclic Aromatic Hydrocarbons in Soils of Chattanooga, Tennessee, USA.

    Science.gov (United States)

    Hussar, Erika; Richards, Sean; Lin, Zhi-Qing; Dixon, Robert P; Johnson, Kevin A

    2012-11-01

    South Chattanooga has been home to foundries, coke furnaces, chemical, wood preserving, tanning and textile plants for over 100 years. Most of the industries were in place before any significant development of residential property in the area. During the 1950s and 1960s, however, the government purchased inexpensive property and constructed public housing projects in South Chattanooga. Many neighborhoods that surround the Chattanooga Creek were previous dumping grounds for industry. Polycyclic aromatic hydrocarbons (PAHs) comprised the largest component of the dumping and airborne industrial emissions. To address the human exposure to these PAHs, a broad study of South Chattanooga soil contaminant concentrations was conducted on 20 sites across the city. Sixteen priority pollutant PAHs were quantified at two depths (0-10cm and 10-20cm) and compared against reference site soils, as well as to soils from industrially-impacted areas in Germany, China, and the US. From these data, the probability that people would encounter levels exceeding EPA Residential Preliminary Remediation Goals (PRG) was calculated. Results indicate that South Chattanooga soils have relatively high concentrations of total PAHs, specifically Benzo[a]pyrene (B[a]P). These high concentrations of B[a]P were somewhat ubiquitous in South Chattanooga. Indeed, there is a high probability (88%) of encountering soil in South Chattanooga that exceeds the EPA PRG for B[a]P. However, there is a low probability (15%) of encountering a site with ∑PAHs exceeding EPA PRG guidelines.

  9. The Composition of Cigarette Smoke. An Historical Perspective of Several Polycyclic Aromatic Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Rodgman A

    2014-12-01

    Full Text Available Because of the significant advancements in fractionation, analytical, and characterization technologies since the early 1960s, hundreds of components of complex mixtures have been accurately characterized without the necessity of actually isolating the individual component. This has been particularly true in the case of the complex mixtures tobacco and tobacco smoke. Herein, an historical account of a mid-1950 situation concerning polycyclic aromatic hydrocarbons (PAHs in cigarette smoke is presented. While the number of PAHs identified in tobacco smoke has escalated from the initial PAH, azulene, identified in 1947 to almost 100 PAHs identified by late 1963 to more than 500 PAHs identified by the late 1970s, the number of PAHs isolated individually and characterized by several of the so-called classical chemical means (melting point, mixture melting point, derivative preparation and properties in the mid-1950s and since is relatively few, 14 in all. They were among 44 PAHs identified in cigarette mainstream smoke and included the following PAHs ranging from bicyclic to pentacyclic: Acenaphthylene, 1,2-dihydroacenaphthylene, anthracene, benz[a]anthracene, benzo[a]pyrene, chrysene, dibenz[a, h]anthracene, fluoranthene, 9H-fluorene, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, phenanthrene, and pyrene. One of them, benzo[a]pyrene, was similarly characterized in another study in 1959 by Hoffmann.

  10. Dynamic Effects of Biochar on the Bacterial Community Structure in Soil Contaminated with Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Song, Yang; Bian, Yongrong; Wang, Fang; Xu, Min; Ni, Ni; Yang, Xinglun; Gu, Chenggang; Jiang, Xin

    2017-08-16

    Amending soil with biochar is an effective soil remediation strategy for organic contaminants. This study investigated the dynamic effects of wheat straw biochar on the bacterial community structure during remediation by high-throughput sequencing. The wheat straw biochar amended into the soil significantly reduced the bioavailability and toxicity of polycyclic aromatic hydrocarbons (PAHs). Biochar amendment helped to maintain the bacterial diversity in the PAH-contaminated soil. The relationship between the immobilization of PAHs and the soil bacterial diversity fit a quadratic model. Before week 12 of the incubation, the incubation time was the main factor contributing to the changes in the soil bacterial community structure. However, biochar greatly affected the bacterial community structure after 12 weeks of amendment, and the effects were dependent upon the biochar type. Amendment with biochar mainly facilitated the growth of rare bacterial genera (relative abundance of 0.01-1%) in the studied soil. Therefore, the application of wheat straw biochar into PAH-contaminated soil can reduce the environmental risks of PAHs and benefit the soil microbial ecology.

  11. Spatial Characterization of Polycyclic Aromatic Hydrocarbons in 2008 TC3 Samples

    Science.gov (United States)

    Sabbah, Hassan; Morrow, A.; Zare, R. N.; Jenniskens, P.

    2009-09-01

    Hassan Sabbah1, Amy L. Morrow1, Richard N. Zare1 and Petrus Jenniskens2 1Stanford University, Stanford, California 94305, 2 SETI Institute, Carl Sagan Center, 515 North Whisman Road, Mountain View, California 94043, USA. In October 2006 a small asteroid (2-3 meters) was observed in outer space. On October 7, 2008, it entered the Earth's atmosphere creating a fireball over Northern Sudan. Some 280 meteorites were collected by the University of Khartoum. In order to explore the existence of organic materials, specifically polycyclic aromatic hydrocarbons (PAHs), we applied two-step laser desorption laser ionization mass spectrometry (L2MS) to some selected fragments. This technique consists of desorbing with a pulsed infrared laser beam the solid materials into a gaseous phase with no fragmentation followed by resonance enhanced multiphoton ionization to analyze the PAH content. L2MS was already applied to an array of extraterrestrial objects including interplanetary dust particles IDPs, carbonaceous chondrites and comet coma particles. Moreover, spatial resolution of PAHs in 2008 TC3 samples was achieved to explore the heterogeneity within individual fragments. The results of these studies and their contribution to understanding the formation of this asteroid will be discussed.

  12. Removal of polycyclic aromatic hydrocarbons from aged-contaminated soil using cyclodextrins: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Viglianti, Christophe [Laboratoire d' Analyse Environnementale des Procedes et des Systemes Industriels - INSA de Lyon, 9, rue de la Physique - 69621 Villeurbanne Cedex (France); Centre Sciences, Information et Technologies pour l' Environnement (SITE) - ENS de Mines de Saint Etienne, 158 cours Fauriel - 42023 Saint Etienne Cedex 2 (France); Hanna, Khalil [Laboratoire d' Analyse Environnementale des Procedes et des Systemes Industriels - INSA de Lyon, 9, rue de la Physique - 69621 Villeurbanne Cedex (France)]. E-mail: khalilhanna@hotmail.com; Brauer, Christine de [Laboratoire d' Analyse Environnementale des Procedes et des Systemes Industriels - INSA de Lyon, 9, rue de la Physique - 69621 Villeurbanne Cedex (France); Germain, Patrick [Laboratoire d' Analyse Environnementale des Procedes et des Systemes Industriels - INSA de Lyon, 9, rue de la Physique - 69621 Villeurbanne Cedex (France)

    2006-04-15

    The removal of polycyclic aromatic hydrocarbons (PAHs) from soil using water as flushing agent is relatively ineffective due to their low aqueous solubility. However, addition of cyclodextrin (CD) in washing solutions has been shown to increase the removal efficiency several times. Herein are investigated the effectiveness of cyclodextrin to remove PAH occurring in industrially aged-contaminated soil. {beta}-Cyclodextrin (BCD), hydroxypropyl-{beta}-cyclodextrin (HPCD) and methyl-{beta}-cyclodextrin (MCD) solutions were used for soil flushing in column test to evaluate some influent parameters that can significantly increase the removal efficiency. The process parameters chosen were CD concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant and almost linear effect on PAH removal from the contaminated soil, except the temperature where no significant enhancement in PAH extraction was observed for temperature range from 5 to 35 {sup o}C. The PAHs extraction enhancement factor compared to water was about 200. - An innovative method using a biodegradable and non-toxic flushing agent for the depollution of industrially aged-contaminated soil.

  13. Urinary metabolites of polycyclic aromatic hydrocarbons, sperm DNA damage and spermatozoa apoptosis.

    Science.gov (United States)

    Yang, Pan; Wang, Yi-Xin; Sun, Li; Chen, Ying-Jun; Liu, Chong; Huang, Li-Li; Lu, Wen-Qing; Zeng, Qiang

    2017-05-05

    Inconsistent results between polycyclic aromatic hydrocarbons (PAHs) exposure and adverse male reproductive health have been reported in humans. To assess whether PAH exposure is associated with declined sperm function. Ten monohydroxylated PAHs (OH-PAHs) metabolites were analyzed in repeated urine samples from an infertility clinic. We used multivariable linear models to estimate the associations of urinary OH-PAH metabolites with sperm DNA damage (n=405) and spermatozoa apoptosis (n=366). The shapes of dose-dependent associations of exposure measurements with outcomes were further evaluated by restricted cubic splines. Multiple comparisons were adjusted by false discovery rate (FDR). We found that urinary 9-hydroxyfluorene (9-OHFlu) was associated with increased tail length and comet length (p for trend=0.05 and 0.01, respectively), and that urinary 9-hydroxyphenanthrene (9-OHPh) was associated with decreased percentage of Annexin V - /PI - spermatozoa (p for trend=0.04). Also, suggestive associations of urinary 9-OHPh and ∑OHFlu with increased comet length, and urinary 9-OHFlu and 2-OHPh with decreased percentage of Annexin V - /PI - spermatozoa were observed (all p for trends cubic splines. Our results suggest that environmental exposure to fluorene and phenanthrene are associated with declined sperm function. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air.

    Science.gov (United States)

    Gregoris, Elena; Barbaro, Elena; Morabito, Elisa; Toscano, Giuseppa; Donateo, Antonio; Cesari, Daniela; Contini, Daniele; Gambaro, Andrea

    2016-04-01

    Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. Graphical abstract Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter and evaluation of the effect of an European Directive on air quality in Venice.

  15. Essential Metals Zinc, Selenium, and Strontium Protect against Chromosome Damage Caused by Polycyclic Aromatic Hydrocarbons Exposure.

    Science.gov (United States)

    Bai, Yansen; Feng, Wei; Wang, Suhan; Zhang, Xiao; Zhang, Wangzhen; He, Meian; Zhang, Xiaomin; Wu, Tangchun; Guo, Huan

    2016-01-19

    Essential metals play important roles in maintaining cellular homeostasis, but the effects of their interaction with the environmental pollutants are still not very well-known in human subjects. The aim of this study was to evaluate the roles of essential metals and their interactions with polycyclic aromatic hydrocarbons (PAHs) on chromosome damage, an early carcinogenic event. A total of 1245 male workers were included in this study and the levels of 11 urinary essential metals, 12 urinary PAH metabolites, plasma concentrations of benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, and lymphocyte micronucleus (MN) frequencies were monitored. We found that zinc (Zn), selenium (Se), and strontium (Sr) have significant inverse dose-response relationships with MN frequencies (all P < 0.05). Furthermore, the protective roles of Zn, Se, and Sr were mainly shown among subjects with high levels of BPDE-Alb adducts. Significant effect modification of BPDE-Alb adducts on the associations of Zn, Se, and Sr with MN frequencies was observed (all Pinteraction < 0.05). Our study showed evidence that Zn, Se, and Sr play protective roles in reducing chromosome damage, and these effects can be modified by PAH exposure levels. These findings add potential evidence for the preventive effects of Zn, Se, and Sr against carcinogenesis in human subjects.

  16. Effects of grilling procedures on levels of polycyclic aromatic hydrocarbons in grilled meats.

    Science.gov (United States)

    Lee, Joon-Goo; Kim, Su-Yeon; Moon, Jung-Sik; Kim, Sheen-Hee; Kang, Dong-Hyun; Yoon, Hae-Jung

    2016-05-15

    Polycyclic aromatic hydrocarbons (PAHs) are chemicals formed when muscle meat is cooked using high-temperature methods, such as grilling directly over an open flame. PAHs have been found to be mutagenic-that is, they cause changes in DNA that may increase the risk of cancer. We investigated the effects of grilling procedures on the level of 4 PAHs; benzo[a]anthracene (B[a]A), chrysene (Chr), benzo[b]fluoranthene (B[b]F), and benzo[a]pyrene (B[a]P). PAHs were extracted and determined by gas chromatography with mass detection (GC-MS). With regard to barbecuing successive meat samples with the same batch of burning charcoal, it was observed that stable combustion contribute to reduction of PAHs. Significant reductions in the sum of the four PAHs were observed through treatments which removed meat drippings and smoke with alternative grilling apparatus. The sums of 4 PAHs were reduced 48-89% with dripping removed and 41-74% with the smoke removal treatment in grilled pork and beef meats than conventional grilling. We investigated the components of meats drippings. The major constituent of meat dripping was fat. The most important factor contributing to the production of PAHs in grilling was smoke resulting from incomplete combustion of fat dripped onto the fire. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Photocatalytic oxidation of polycyclic aromatic hydrocarbons: Intermediates identification and toxicity testing

    International Nuclear Information System (INIS)

    Woo, O.T.; Chung, W.K.; Wong, K.H.; Chow, Alex T.; Wong, P.K.

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic pollutants and their low water solubility limits their degradation in aqueous solution. The presence of water-miscible solvent such as acetone can increase the water solubility of PAHs, however acetone will also affect the degradation of PAH. In this study the effects of acetone on the photocatalytic degradation efficiency and pathways of 5 selected PAHs, namely naphthalene (2 rings), acenaphthylene (3 rings), phenanthrene (3 rings), anthracene (3 rings) and benzo[a]anthracene (4 rings) were investigated. The Microtox toxicity test was used to determine whether the PCO system can completely detoxify the parental PAHs and its intermediates. The addition of 16% acetone can greatly alter the degradation pathway of naphthalene and anthracene. Based on intermediates identified from degradation of the 5 PAHs, the location of parental PAHs attacked by reactive free radicals can be correlated with the localization energies of different positions of the compound. For toxicity analysis, irradiation by UV light was found to induce acute toxicity by generating intermediates/degradation products from PAHs and possibly acetone. Lastly, all PAHs (10 mg l -1 ) can be completely detoxified by titanium dioxide (100 mg l -1 ) within 24 h under UVA irradiation (3.9 mW cm -2 ).

  18. Parent and halogenated polycyclic aromatic hydrocarbons in rice and implications for human health in China

    International Nuclear Information System (INIS)

    Ding Chao; Ni Honggang; Zeng Hui

    2012-01-01

    Rice is the staple food for approximate two thirds of the Chinese population. However, human exposure to parent and halogenated polycyclic aromatic hydrocarbons (PAHs) via rice consumption is still not clear for Chinese people so far. The goals of this work are to assess human exposure to PAHs and halogenated PAHs (HPAHs) via rice ingestion and the cancer risk for Chinese population. 16 PAHs and eight HPAHs were determined in rice samples collected from 18 provinces in China. In general terms, the general population in China was exposed to higher levels of PAHs via rice ingestion in comparison to that via cereals for other countries. The cancer risk values induced by exposure to PAHs and HPAHs for male and female on each age group were between the priority risk level (10 −4 ) and the acceptable risk level (10 −6 ). Children faced the highest cancer risk, followed by adolescents and adults. - Highlights: ► Dietary exposure to PAHs via rice ingestion for Chinese population was higher than that via cereals in other countries. ► The cancer risk induced by PAHs and HPAHs intakes via rice consumption were between 10 −6 and 10 −4 . ► Children faced the highest cancer risk, followed by adolescents and adults. ► Given all exposure routes were considered, the real cancer risk for Chinese people would be greater. - Human exposure to parent and halogenated PAHs via rice ingestion and the cancer risk for Chinese population were assessed.

  19. Atmospheric bulk deposition of polycyclic aromatic hydrocarbons in Shanghai: Temporal and spatial variation, and global comparison.

    Science.gov (United States)

    Feng, Daolun; Liu, Ying; Gao, Yi; Zhou, Jinxing; Zheng, Lirong; Qiao, Gang; Ma, Liming; Lin, Zhifen; Grathwohl, Peter

    2017-11-01

    Atmospheric deposition leads to accumulation of atmospheric polycyclic aromatic hydrocarbons (PAHs) on urban surfaces and topsoils. To capture the inherent variability of atmospheric deposition of PAHs in Shanghai's urban agglomeration, 85 atmospheric bulk deposition samples and 7 surface soil samples were collected from seven sampling locations during 2012-2014. Total fluxes of 17 PAHs were 587-32,300 ng m -2 day -1 , with a geometric mean of 2600 ng m -2 day -1 . The deposition fluxes were categorized as moderate to high on a global scale. Phenanthrene, fluoranthene and pyrene were major contributors. The spatial distribution of deposition fluxes revealed the influence of urbanization/industrialization and the relevance of local emissions. Meteorological conditions and more heating demand in cold season lead to a significant increase of deposition rates. Atmospheric deposition is the principal pathway of PAHs input to topsoils and the annual deposition load in Shanghai amounts to ∼4.5 tons (0.7 kg km -2 ) with a range of 2.5-10 tons (0.4-1.6 kg km -2 ). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach.

    Science.gov (United States)

    Zheng, Yi; Lin, Zhongrong; Li, Hao; Ge, Yan; Zhang, Wei; Ye, Youbin; Wang, Xuejun

    2014-05-15

    Urban stormwater runoff delivers a significant amount of polycyclic aromatic hydrocarbons (PAHs), mostly of atmospheric origin, to receiving water bodies. The PAH pollution of urban stormwater runoff poses serious risk to aquatic life and human health, but has been overlooked by environmental modeling and management. This study proposed a dynamic modeling approach for assessing the PAH pollution and its associated environmental risk. A variable time-step model was developed to simulate the continuous cycles of pollutant buildup and washoff. To reflect the complex interaction among different environmental media (i.e. atmosphere, dust and stormwater), the dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. Long-term simulations of the model can be efficiently performed, and probabilistic features of the pollution level and its risk can be easily determined. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. The results showed that Beijing's PAH pollution of road runoff is relatively severe, and its associated risk exhibits notable seasonal variation. The current sweeping practice is effective in mitigating the pollution, but the effectiveness is both weather-dependent and compound-dependent. The proposed modeling approach can help identify critical timing and major pollutants for monitoring, assessing and controlling efforts to be focused on. The approach is extendable to other urban areas, as well as to other contaminants with similar fate and transport as PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Dissipation of polycyclic aromatic hydrocarbons (PAHs) in the rhizosphere: Synthesis through meta-analysis

    International Nuclear Information System (INIS)

    Ma Bin; He Yan; Chen Huaihai; Xu Jianming; Rengel, Zed

    2010-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread and persistent organic pollutants with high carcinogenic effect and toxicity; their behavior and fate in the soil-plant system have been widely investigated. In the present paper, meta-analysis was used to explore the interaction between plant growth and dissipation of PAHs in soil based on the large body of published literature. Plants have a promoting effect on PAH dissipation in soils. There was no difference in PAH dissipation between soils contaminated with single and mixed PAHs. However, plants had a more obvious effect on PAH dissipation in freshly-spiked soils than in long-term field-polluted soils. Additionally, a positive effect of the number of microbial populations capable of degrading PAHs was observed in the rhizosphere compared with the bulk soil. Our meta-analysis established the importance of the rhizosphere effect on PAH dissipation in variety of the soil-plant systems. - The meta-analysis provides the first quantitative evidence of the positive effect of rhizosphere processes on PAH dissipation.

  2. Effects of Large Polycyclic Aromatic Hydrocarbons on the Soot Formation in Ethylene-Air Nonpremixed Flames

    KAUST Repository

    Prabhu, S.

    2015-03-30

    This study presents updated comprehensive gas-phase kinetic mechanism and aerosol models to predict soot formation characteristics in ethylene-air nonpremixed flames. A main objective is to investigate the sensitivity of the soot formation rate to various chemical pathways for large polycyclic aromatic hydrocarbons (PAH). In this study, the detailed chemical mechanism was reduced from 397 to 99 species using directed relation graph (DRG) and sensitivity analysis. The method of moments with interpolative closure (MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames of pure ethylene at low strain rate sooting conditions are considered, for which the sensitivity of soot formation characteristics with respect to hetrogeneous nucleation is investigated. Results show that higher PAH concentrations result in higher soot nucleation rate, and that the average size of the particles are in good agreement with experimental results. It is found that the nucleation processes (i.e., soot inception) from higher PAH precursors, coronene in particular, is critical for accurate prediction of the overall soot formation.

  3. Monitoring exposure to polycyclic aromatic hydrocarbons in an Australian population using pooled urine samples.

    Science.gov (United States)

    Thai, Phong K; Heffernan, Amy L; Toms, Leisa-Maree L; Li, Zheng; Calafat, Antonia M; Hobson, Peter; Broomhall, Sara; Mueller, Jochen F

    2016-03-01

    Integrated exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed through monitoring of urinary mono-hydroxylated PAHs (OH-PAHs). The aim of this study was to provide the first assessment of exposure to PAHs in a large sample of the population in Queensland, Australia including exposure to infant (0-4years). De-identified urine specimens, obtained from a pathology laboratory, were stratified by age and sex, and pooled (n=24 pools of 100) and OH-PAHs were measured by gas chromatography-isotope dilution-tandem mass spectrometry. Geometric mean (GM) concentrations ranged from 30ng/L (4-hydroxyphenanthrene) to 9221ng/L (1-naphthol). GM of 1-hydroxypyrene, the most commonly used PAH exposure biomarker, was 142ng/L. The concentrations of OH-PAHs found in this study are consistent with those in developed countries and lower than those in developing countries. We observed no association between sex and OH-PAH concentrations. However, we observed lower urinary concentrations of all OH-PAHs in samples from infants (0-4years), children (5-14years) and the elderly (>60year old) compared with samples from other age groups (15-29, 30-44 and 45-59years) which may be attributed to age-dependent behaviour-specific exposure sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Polycyclic Aromatic Hydrocarbons (PAHs) and their Bioaccessibility in Meat: a Tool for Assessing Human Cancer Risk.

    Science.gov (United States)

    Hamidi, Elliyana Nadia; Hajeb, Parvaneh; Selamat, Jinap; Abdull Razis, Ahmad Faizal

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are primarily formed as a result of thermal treatment of food, especially barbecuing or grilling. Contamination by PAHs is due to generation by direct pyrolysis of food nutrients and deposition from smoke produced through incomplete combustion of thermal agents. PAHs are ubiquitous compounds, well-known to be carcinogenic, which can reach the food in different ways. As an important human exposure pathway of contaminants, dietary intake of PAHs is of increasing concern for assessing cancer risk in the human body. In addition, the risks associated with consumption of barbecued meat may increase if consumers use cooking practices that enhance the concentrations of contaminants and their bioaccessibility. Since total PAHs always overestimate the actual amount that is available for absorption by the body, bioaccessibility of PAHs is to be preferred. Bioaccessibility of PAHs in food is the fraction of PAHs mobilized from food matrices during gastrointestinal digestion. An in vitro human digestion model was chosen for assessing the bioaccessibility of PAHs in food as it offers a simple, rapid, low cost alternative to human and animal studies; providing insights which may not be achievable in in vivo studies. Thus, this review aimed not only to provide an overview of general aspects of PAHs such as the formation, carcinogenicity, sources, occurrence, and factors affecting PAH concentrations, but also to enhance understanding of bioaccessibility assessment using an in vitro digestion model.

  5. Investigation on the Binding of Polycyclic AromaticHydrocarbons with Soil Organic Matter: A Theoretical Approach

    Directory of Open Access Journals (Sweden)

    Supa Hannongbua

    2007-04-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are ubiquitous contaminants of the terrestrial environment that have been designated as Environmental Protection Agency (EPA Priority Pollutants. In this study, molecular modeling was used to examine the physical and chemical characteristics of soil organic matter (SOM, fulvic acid (FA and humic acid (HA, as well as their binding interactions with PAHs. The molecular structures of 18 PAHs were built by using the SYBYL 7.0 program and then fully optimized by a semiempirical (AM1 method. A molecular docking program, AutoDock 3.05, was used to calculate the binding interactions between the PAHs, and three molecular structure models including FA (Buffle’s model, HA (Stevenson’s model and SOM (Schulten and Schnitzer’s model. The π-π interactions and H-bonding interactions were found to play an important role in the intermolecular bonding of the SOM/PAHs complexes. In addition, significant correlations between two chemical properties, boiling point (bp and octanol/water partition coefficient (Log Kow and final docking energies were observed. The preliminary docking results provided knowledge of the important binding modes to FA, HA and SOM, and thereby to predict the sorption behavior of PAHs and other pollutants.

  6. Implications of Bioremediation of Polycyclic Aromatic Hydrocarbon-Contaminated Soils for Human Health and Cancer Risk.

    Science.gov (United States)

    Davie-Martin, Cleo L; Stratton, Kelly G; Teeguarden, Justin G; Waters, Katrina M; Simonich, Staci L Massey

    2017-09-05

    Bioremediation uses soil microorganisms to degrade polycyclic aromatic hydrocarbons (PAHs) into less toxic compounds and can be performed in situ, without the need for expensive infrastructure or amendments. This review provides insights into the cancer risks associated with PAH-contaminated soils and places bioremediation outcomes in a context relevant to human health. We evaluated which bioremediation strategies were most effective for degrading PAHs and estimated the cancer risks associated with PAH-contaminated soils. Cancer risk was statistically reduced in 89% of treated soils following bioremediation, with a mean degradation of 44% across the B2 group PAHs. However, all 180 treated soils had postbioremediation cancer risk values that exceeded the U.S. Environmental Protection Agency (USEPA) health-based acceptable risk level (by at least a factor of 2), with 32% of treated soils exceeding recommended levels by greater than 2 orders of magnitude. Composting treatments were most effective at biodegrading PAHs in soils (70% average reduction compared with 28-53% for the other treatment types), which was likely due to the combined influence of the rich source of nutrients and microflora introduced with organic compost amendments. Ultimately, bioremediation strategies, in the studies reviewed, were unable to successfully remove carcinogenic PAHs from contaminated soils to concentrations below the target cancer risk levels recommended by the USEPA.

  7. Variations in the bioavailability of polycyclic aromatic hydrocarbons in industrial and agricultural soils after bioremediation.

    Science.gov (United States)

    Guo, Meixia; Gong, Zongqiang; Allinson, Graeme; Tai, Peidong; Miao, Renhui; Li, Xiaojun; Jia, Chunyun; Zhuang, Jie

    2016-02-01

    The aim of this study was to demonstrate the variations in bioavailability remaining in industrial and agricultural soils contaminated by polycyclic aromatic hydrocarbons (PAHs) after bioremediation. After inoculation of Mycobacterium sp. and Mucor sp., PAH biodegradation was tested on a manufactured gas plant (MGP) soil and an agricultural soil. PAH bioavailability was assessed before and after biodegradation using solid-phase extraction (Tenax-TA extraction) and solid-phase micro-extraction (SPME) to represent bioaccessibility and chemical activity of PAHs, respectively. Only 3- and 4-ring PAHs were noticeably biodegradable in the MGP soil. PAH biodegradation in the agricultural soil was different from that in the MGP soil. The rapidly desorbing fractions (F(rap)) extracted by Tenax-TA and the freely dissolved concentrations of 3- and 4-ring PAHs determined by SPME from the MGP soil decreased after 30 days biodegradation; those values of the 5- and 6-ring PAHs changed to a lesser degree. For the agricultural soil, the F(rap) values of the 3- and 4-ring PAHs also decreased after the biodegradation experiment. The Tenax-TA extraction and the SPME have the potential to assess variations in the bioavailability of PAHs and the degree of biodegradation in contaminated MGP soils. In addition, Tenax-TA extraction is more sensitive than SPME when used in the agricultural soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Differential electron emission from polycyclic aromatic hydrocarbon molecules under fast ion impact.

    Science.gov (United States)

    Biswas, Shubhadeep; Champion, Christophe; Weck, P F; Tribedi, Lokesh C

    2017-07-17

    Interaction between polycyclic aromatic hydrocarbon (PAH) molecule and energetic ion is a subject of interest in different areas of modern physics. Here, we present measurements of energy and angular distributions of absolute double differential electron emission cross section for coronene (C 24 H 12 ) and fluorene (C 13 H 10 ) molecules under fast bare oxygen ion impact. For coronene, the angular distributions of the low energy electrons are quite different from that of simpler targets like Ne or CH 4 , which is not the case for fluorene. The behaviour of the higher electron energy distributions for both the targets are similar to that for simple targets. In case of coronene, a clear signature of plasmon resonance is observed in the analysis of forward-backward angular asymmetry of low energy electron emission. For fluorene, such signature is not identified probably due to lower oscillator strength of plasmon compared to the coronene. The theoretical calculation based on the first-order Born approximation with correct boundary conditions (CB1), in general, reproduced the experimental observations qualitatively, for both the molecules, except in the low energy region for coronene, which again indicates the role of collective excitation. Single differential and total cross sections are also deduced. An overall comparative study is presented.

  9. Polystyrene plastic: a source and sink for polycyclic aromatic hydrocarbons in the marine environment.

    Science.gov (United States)

    Rochman, Chelsea M; Manzano, Carlos; Hentschel, Brian T; Simonich, Staci L Massey; Hoh, Eunha

    2013-12-17

    Polycyclic aromatic hydrocarbons (PAHs) on virgin polystyrene (PS) and PS marine debris led us to examine PS as a source and sink for PAHs in the marine environment. At two locations in San Diego Bay, we measured sorption of PAHs to PS pellets, sampling at 0, 1, 3, 6, 9, and 12 months. We detected 25 PAHs using a new analytical method with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. Several congeners were detected on samples before deployment. After deployment, some concentrations decreased (1,3-dimethylnaphthalene and 2,6-methylnaphthalene), while most increased [2-methylanthracene and all parent PAHs (PPAHs), except fluorene and fluoranthene], suggesting that PS debris is a source and sink for PAHs. When sorbed concentrations of PPAHs on PS are compared to the five most common polymers [polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP)], PS sorbed greater concentrations than PP, PET, and PVC, similar to HDPE and LDPE. Most strikingly, at 0 months, PPAHs on PS ranged from 8 to 200 times greater than on PET, HDPE, PVC, LDPE, and PP. The combination of greater PAHs in virgin pellets and large sorption suggests that PS may pose a greater risk of exposure to PAHs upon ingestion.

  10. Detection of Polarized Infrared Emission by Polycyclic Aromatic Hydrocarbons in the MWC 1080 Nebula

    International Nuclear Information System (INIS)

    Zhang, Han; Telesco, Charles M.; Pantin, Eric; Barnes, Peter; Hoang, Thiem; Li, Aigen; Wright, Christopher M.; Li, Dan

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in astrophysical environments, as revealed by their pronounced emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m commonly ascribed to the C–H and C–C vibrational modes. Although these features have long been predicted to be polarized, previous searches for PAH polarization led to null or, at best, tentative detections. Here we report the definite detection of polarized PAH emission at 11.3 μ m in the nebula associated with the Herbig Be star MWC 1080. We measure a polarization degree of 1.9% ± 0.2%, which is unexpectedly high compared to models. This poses a challenge in the current understanding of the alignment of PAHs, which is required to polarize the PAH emission but thought to be substantially suppressed. PAH alignment with a magnetic field via a resonance paramagnetic relaxation process may account for such a high level of polarization.

  11. Dry deposition of atmospheric polycyclic aromatic hydrocarbons in three Plantago species

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, M.I.; Vorenhout, M.; Sijm, D.T.H.M.; Kolloeffel, C.

    1999-10-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) in the leaf wax of three Plantago species were determined weekly for 3 weeks. The almost glabrous, free-standing leaves of Plantago major and the sparsely hairy Plantago lanceolata leaves were more heavily contaminated with low molecular weight (MW) PAHs (MW {lt} 228) than the densely hairy, partly overlapping Plantago media leaves. This may be caused by the lower canopy roughness (higher aerodynamic resistance), the higher amount of leaf hairs, and/or the higher leaf overlap of P. media. On the other hand, PAHs with MW {ge} 252 tended to show higher concentrations in P. media than in the other two species. This is likely caused by the dense layer of hairs on P. media leaves, which can efficiently intercept the largely particle-bound high MW PAHs. When the PAH concentrations were normalized to projected leaf surface area, the differences between P. media and the other two species became significant for the high MW PAHs, while the differences for the low MW PAHs decreased. Although the differences in PAH concentrations between species are relatively small, this study clearly shows that plant architecture and leaf hairs influence the dry deposition of PAHs.

  12. Predicting Polycyclic Aromatic Hydrocarbon Bioavailability to Mammals from Incidentally Ingested Soils Using Partitioning and Fugacity.

    Science.gov (United States)

    James, Kyle; Peters, Rachel E; Cave, Mark R; Wickstrom, Mark; Lamb, Eric G; Siciliano, Steven D

    2016-02-02

    Soil and dust ingestion is one of the major human exposure pathways to contaminated soil; however, pollutant transfer from ingested substances to humans cannot currently be confidently predicted. Soil polycyclic aromatic hydrocarbon (PAH) bioavailability is likely dependent upon properties linked to chemical potential and partitioning such as fugacity, fugacity capacity, soil organic carbon, and partitioning to simulated intestinal fluids. We estimated the oral PAH bioavailability of 19 historically contaminated soils fed to juvenile swine. Between soils, PAH blood content, with the exception of benzo(a)pyrene, was not linked to fugacity. In contrast, between individual PAHs, using partitioning explained PAH blood content (area under the curve = 0.47 log fugacity + 0.34, r(2) = 0.68, p fugacity capacity predicts PAH soil concentration with an average slope of 0.30 (μg PAH g(-1) soil) Pa(-1) and r(2)'s of 0.61-0.73. Because PAH blood content was independent of soil concentration, soil fugacity correlated to PAH bioavailability via soil fugacity's link to soil concentration. In conclusion, we can use fugacity to explain PAH uptake from a soil into blood. However, something other than partitioning is critical to explain the differences in PAH uptake into blood between soils.

  13. Fugacity approach to evaluate the sediment-water diffusion of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, De-Gao; Alaee, Mehran; Byer, Jonathan; Liu, Yong-Jun; Tian, Chong-Guo

    2011-06-01

    Diffusion is an important process for sediment-water exchange and plays a vital role in controlling water quality. Fugacity fraction (ff) was used to estimate the sediment-water diffusion of polycyclic aromatic hydrocarbons (PAHs) between seawater and surficial sediment. A total of 33 surface sediment and sea water samples were collected concurrently from the northeast coastal area in China and 25 PAHs were analyzed including the alkylated and chlorated PAHs. Fugacity fraction was calculated based on the PAH concentrations in water and sediment, octanol-water partition coefficient of PAHs, organic matter content in sediment, and density of sediment. The calculated results showed that ff increased with decreasing molecular weight of PAHs. The low molecular weight PAHs (2-3 rings) transferred from sediment to water and the sediment acted as a secondary source to the water. The medium molecular weight PAHs (4-5 rings) were close to the sediment-water equilibrium and the transfer tendency shifted between sediment and water. The high molecular weight PAHs (5-6 rings) transferred from water into sediment and the sediment acted as a sink. Soot carbon and the difference of PAH concentrations between sediment and water were found to be important factors affecting the sediment-water diffusion. This study provided new insight into the process of sediment-water diffusion, which has a great influence on the quality of water, especially in severely-polluted sediment areas.

  14. Prenatal airborne polycyclic aromatic hydrocarbon exposure and child IQ at age 5 years.

    Science.gov (United States)

    Perera, Frederica P; Li, Zhigang; Whyatt, Robin; Hoepner, Lori; Wang, Shuang; Camann, David; Rauh, Virginia

    2009-08-01

    This study evaluated the relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and child intelligence. Children of nonsmoking black or Dominican-American women residing in New York City were monitored from in utero to 5 years of age, with determination of prenatal PAH exposure through personal air monitoring for the mothers during pregnancy. At 5 years of age, intelligence was assessed for 249 children by using the Wechsler Preschool and Primary Scale of Intelligence-Revised. Multivariate linear regression models were used to estimate and to test the associations between prenatal PAH exposure and IQ. After adjustment for maternal intelligence, quality of the home caretaking environment, environmental tobacco smoke exposure, and other potentially confounding factors, high PAH levels (above the median of 2.26 ng/m(3)) were inversely associated with full-scale IQ (P = .007) and verbal IQ (P = .003) scores. Children in the high-exposure group had full-scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively, than those of less-exposed children (IQ measures also were significant (full-scale IQ: beta = -3.00; P = .009; verbal IQ: beta = -3.53; P = .002). These results provide evidence that environmental PAHs at levels encountered in New York City air can affect children's IQ adversely.

  15. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust.

    Science.gov (United States)

    Chang, Chang-Tang; Chen, Bor-Yann

    2008-05-30

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5 alpha. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC50, was approximately as follows: PAHs>two-stroke engines>four-stroke engines>BTEX.

  16. Potential of Polycyclic Aromatic Hydrocarbon-Degrading Bacterial Isolates to Contribute to Soil Fertility

    Directory of Open Access Journals (Sweden)

    Maryam Bello-Akinosho

    2016-01-01

    Full Text Available Restoration of polycyclic aromatic hydrocarbon- (PAH- polluted sites is presently a major challenge in agroforestry. Consequently, microorganisms with PAH-degradation ability and soil fertility improvement attributes are sought after in order to achieve sustainable remediation of polluted sites. This study isolated PAH-degrading bacteria from enriched cultures of spent automobile engine-oil polluted soil. Isolates’ partial 16S rRNA genes were sequenced and taxonomically classified. Isolates were further screened for their soil fertility attributes such as phosphate solubilization, atmospheric nitrogen fixation, and indoleacetic acid (IAA production. A total of 44 isolates were obtained and belong to the genera Acinetobacter, Arthrobacter, Bacillus, Flavobacterium, Microbacterium, Ochrobactrum, Pseudomonas, Pseudoxanthomonas, Rhodococcus, and Stenotrophomonas. Data analysed by principal component analysis showed the Bacillus and Ochrobactrum isolates displayed outstanding IAA production. Generalized linear modelling statistical approaches were applied to evaluate the contribution of the four most represented genera (Pseudomonas, Acinetobacter, Arthrobacter, and Rhodococcus to soil fertility. The Pseudomonas isolates were the most promising in all three soil fertility enhancement traits evaluated and all isolates showed potential for one or more of the attributes evaluated. These findings demonstrate a clear potential of the isolates to participate in restorative bioremediation of polluted soil, which will enhance sustainable agricultural production and environmental protection.

  17. Factors controlling leaching of polycyclic aromatic hydrocarbons from petroleum source rock using nonionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Akinlua, Akinsehinwa [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Fossil Fuels and Environmental Geochemistry Group; Jochmann, Maik A.; Qian, Yuan; Schmidt, Torsten C. [Duisburg-Essen Univ., Essen (Germany). Instrumental Analytical Chemistry; Sulkowski, Martin [Duisburg-Essen Univ., Essen (Germany). Inst. of Environmental Analytical Chemistry

    2012-03-15

    The extraction of polycyclic aromatic hydrocarbons (PAHs) from petroleum source rock by nonionic surfactants with the assistance of microwave irradiation was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and type of surfactant have significant effects on extraction yields of PAHs. Factors such as surfactant concentration, irradiation power, sample/solvent ratio and mixing surfactants (i.e., mixture of surfactant at specific ratio) also influence the extraction efficiencies for these compounds. The optimum temperature for microwave-assisted nonionic surfactant extraction of PAHs from petroleum source rock was 120 C and the best suited surfactant was Brij 35. The new method showed extraction efficiencies comparable to those afforded by the Soxhlet extraction method, but a reduction of the extraction times and environmentally friendliness of the new nonionic surfactant extraction system are clear advantages. The results also show that microwave-assisted nonionic surfactant extraction is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock. (orig.)

  18. Factors that influence the extraction of polycyclic aromatic hydrocarbons from coal

    Science.gov (United States)

    Xue, J.; Liu, Gaisheng; Niu, Z.; Chou, C.-L.; Qi, C.; Zheng, Lingyun; Zhang, H.

    2007-01-01

    Coal samples and carbonaceous mudstone were collected from the Huaibei coalfield, China, and experiments investigating the factors influencing the extraction of the sixteen US EPA (Environmental Protection Agency) priority polycyclic aromatic hydrocarbons (PAHs) were carried out. Different extraction times, solvents, and methods were used. Major interest was focused on finding optimum conditions for extracting the PAHs from coal. We conclude that (1) coal composition, including the H/C and O/C ratios, is an important factor for the distribution of PAHs in coals; (2) the total amount of EPA priority PAHs increases with increasing extraction time, 30 min being suitable for ultrasonic-assisted extraction and 24 h for Soxhlet extraction; (3) CS2 is effective in extracting low molecular weight PAHs, while CH2Cl2 is better for extracting high molecular weight PAHs (both are excellent extraction solvents vs hexane); (4) both Soxhlet and ultrasonic extraction showed a similar PAH concentration profile, but the ultrasonic method is less efficient. ?? 2007 American Chemical Society.

  19. Polycyclic aromatic hydrocarbons at selected burning grounds at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Harris, B.W.; Minor, L.K.M.; Flucas, B.J.

    1998-02-01

    A commercial immunoassay field test (IFT) was used to rapidly assess the total concentrations of polycyclic aromatic hydrocarbons (PAHs) in the soil at selected burning grounds within the explosives corridor at Los Alamos National Laboratory (LANL). Results were compared with analyses obtained from LANL Analytical Laboratory and from a commercial laboratory. Both used the Environmental Protection Agency's (EPA's) Methods 8270 and 8310. EPA's Method 8270 employs gas chromatography and mass spectral analyses, whereas EPA's Method 8310 uses an ultraviolet detector in a high-performance liquid chromatography procedure. One crude oil sample and one diesel fuel sample, analyzed by EPA Method 8270, were included for references. On an average the IFT results were lower for standard samples and lower than the analytical laboratory results for the unknown samples. Sites were selected to determine whether the PAHs came from the material burned or the fuel used to ignite the burn, or whether they are produced by a high-temperature chemical reaction during the burn. Even though the crude oil and diesel fuel samples did contain measurable quantities of PAHs, there were no significant concentrations of PAHs detected in the ashes and soil at the burning grounds. Tests were made on fresh soil and ashes collected after a large burn and on aged soil and ashes known to have been at the site more than three years. Also analyzed were twelve-year-old samples from an inactive open burn cage

  20. NATO Advanced Research and CNRS Workshop on Polycyclic Aromatic Hydrocarbons and Astrophysics

    CERN Document Server

    d’Hendecourt, L; Boccara, N

    1987-01-01

    The near Infra-Red emission of the Interstellar Medium is a very puzzling subject. In the brightest regions, where spectroscopic observa­ tions are possible from the ground, several bands (3.3 - 3.4 - 6.2 - 7.7 - 8.6 - 11.3 ~m) have been observed since 1973. The absence of satisfying explanation was so obvious that they were called "Unidenti­ fied IR Emission Bands". The puzzle still increased when were known the first results of the general IR sky survey made by the satellite IRAS. On a large scale, the near IR emission of the Interstellar medium was expected to be very small but it was observed to be about one third of the total IR emission for our own galaxy ..• The situation has moved in 1984 when it was suggested that a class of stable organic molecules, the Polycyclic Aromatic Hydrocarbons (PAH's) could be at the origin of this near IR emission. Initially based on the required refractory character of particules that should be heated to high temperature without subliming, this hypothesis leads to a s...

  1. Spatial and temporal variability of polycyclic aromatic hydrocarbons in sediments from yellow river-dominated margin.

    Science.gov (United States)

    Ding, Su; Xu, Yunping; Wang, Yinghui; Zhang, Xinyu; Zhao, Liang; Ruan, Jiaping; Wu, Weichao

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed for surface sediments and a sediment core from the Yellow River-dominated margin. The concentration of 16 USEPA priority PAHs in surface sediments ranged from 5.6 to 175.4 ng g(-1) dry weight sediment (dws) with a mean of 49.1 ng g(-1) dws. From 1930 to 2011, the distribution of PAHs (37.2 to 210.6 ng g(-1) dws) was consistent with the socioeconomic development of China. The PAHs' concentration peaked in 1964 and 1986, corresponding to the rapid economic growth in China (1958-1965) and the initiation of the "Reform and Open" policy in 1978, respectively. The applications of molecular diagnostic ratios and principal component analysis suggest that PAHs are predominantly produced by the coal and biomass combustion, whereas the contribution of petroleum combustions slightly increased after the 1970s, synchronous with an increasing usage of oil and gas in China.

  2. Solubilization properties of polycyclic aromatic hydrocarbons by saponin, a plant-derived biosurfactant

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Wenjun, E-mail: wenjunzhou@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310028 (China); Yang Juanjuan; Lou Linjie [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310028 (China)

    2011-05-15

    The enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) by saponin, a plant-derived non-ionic biosurfactant, was investigated. The results indicated that the solubilization capabilities of saponin for PAHs were greater than some representative synthetic non-ionic surfactants and showed strong dependence on solution pH and ionic strength. The molar solubilization ratio (MSR) of saponin for phenanthrene was about 3-6 times of those of the synthetic non-ionic surfactants, and decreased by about 70% with the increase of solution pH from 4.0 to 8.0, but increased by approximately 1 times with NaCl concentration increased from 0.01 to 1.0 M. Heavy metal ions can enhance saponin solubilization for phenanthrene and the corresponding MSR values increased by about 25% with the presence of 0.01 M of Cd{sup 2+} or Zn{sup 2+}. Saponin is more effective in enhancing PAHs solubilization than synthetic non-ionic surfactants and has potential application in removing organic pollutants from contaminated soils. - Highlights: > The enhanced solubilization of PAHs by saponin was investigated in this study. > Saponin showed great solubilization capability for PAHs. > Saponin is more effective in enhancing HOCs solubilization at lower solution pH. > Increasing ionic strength can enhance HOCs solubilization in saponin solution. > Heavy metal ions can also enhance phenanthrene solubilization in saponin solution. - Saponin showed different solubilization properties for PAHs from the synthetic non-ionic surfactants and anionic rhamnolipid biosurfactants.

  3. Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies

    International Nuclear Information System (INIS)

    Lau, Ee Von; Gan, Suyin; Ng, Hoon Kiat; Poh, Phaik Eong

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs. -- Highlights: • The alternative and advancement in extraction agents to remove PAHs from soil using soil washing technology is summarised. • The soil regulations for PAH level in various countries are summarized for reference to researchers. • The concentration levels of PAHs in soil at present and the need for soil remediation is presented. -- The efficiency of the extraction agent plays a significant role in soil washing of PAH-contaminated soil

  4. Biodegradation of polycyclic aromatic hydrocarbons (PAH) from crude oil in sandy-beach microcosms

    International Nuclear Information System (INIS)

    Lepo, J.E.; Cripe, C.R.

    2000-01-01

    Experiments were conducted using triplicate microcosm chambers for each treatment of a simulated oil spill on a beach. The treatments were sterile control, 10 ppm of a rhamnolipid biosurfactant added to the seawater and bi-weekly inoculation of the microcosms with two marine bacteria that produce biosurfactants but degrade only n-alkanes. The results showed that raw seawater cycled through the microcosms over a 30-day period led to a substantial depletion of fluorene, phenanthrene, and other polyaromatic hydrocarbons (PAH). It was not possible to detect PAH in pooled test system effluents. The oiled-beach microcosms were run with sterile synthetic seawater to differentiate between wash out and degradation. Depletion of n-alkanes was noticed in the systems inoculated with the alkane-degrading microbes and virtually all the aromatic analytes were recoverable from the oiled sand. The other two treatments permitted the recovery of all the analytes (PAH or alkanes). Under aerobic conditions, the biodegradation by microorganisms indigenous to natural seawater supported that lower molecular weight PAH were substantially depleted, but not the n-alkanes under similar conditions. 16 refs., 4 tabs., 1 fig

  5. Problems in the fingerprints based polycyclic aromatic hydrocarbons source apportionment analysis and a practical solution

    International Nuclear Information System (INIS)

    Zou, Yonghong; Wang, Lixia; Christensen, Erik R.

    2015-01-01

    This work intended to explain the challenges of the fingerprints based source apportionment method for polycyclic aromatic hydrocarbons (PAH) in the aquatic environment, and to illustrate a practical and robust solution. The PAH data detected in the sediment cores from the Illinois River provide the basis of this study. Principal component analysis (PCA) separates PAH compounds into two groups reflecting their possible airborne transport patterns; but it is not able to suggest specific sources. Not all positive matrix factorization (PMF) determined sources are distinguishable due to the variability of source fingerprints. However, they constitute useful suggestions for inputs for a Bayesian chemical mass balance (CMB) analysis. The Bayesian CMB analysis takes into account the measurement errors as well as the variations of source fingerprints, and provides a credible source apportionment. Major PAH sources for Illinois River sediments are traffic (35%), coke oven (24%), coal combustion (18%), and wood combustion (14%). - Highlights: • Fingerprint variability poses challenges in PAH source apportionment analysis. • PCA can be used to group compounds or cluster measurements. • PMF requires results validation but is useful for source suggestion. • Bayesian CMB provide practical and credible solution. - A Bayesian CMB model combined with PMF is a practical and credible fingerprints based PAH source apportionment method

  6. Toxic equivalency factors for halogenated aromatic hydrocarbons determined from embryotoxicity data with Japanese medaka

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, C.D.; Harris, G.; Metcalfe, T.; Bennett, E.; Marshall, T. [Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies Program

    1995-12-31

    Toxic Equivalency Factors (TEFs) for non-ortho substituted PCBs and chlorinated diphenyl ethers have been developed from embryotoxicity data with the Japanese medaka (Oryzias latipes). The medaka TEF for non-ortho PCB congener 126 (0.1) approximates the TEF determined from mammalian experimental models, but the medaka TEFs for other non-ortho PCBs differ from mammalian TEFS. The toxicity of an extract from Lake Ontario rainbow trout to medaka embryos could not be predicted from the Toxic Equivalent Quantities (TEQs) of non-ortho PCBs, 2,3,7,8-TCDD and 2,3,7,8-TCDF in the extract. Embryotoxicity data with subtractions of the trout extract indicated that the ``non-toxic`` PCBs in complex mixtures may modify the toxicity of the non-ortho congeners. Data on the embryotoxicity of chlorinated diphenyl ethers (CDPEs) to medaka indicate that mono-ortho substituted CDPEs are more toxic than non-ortho substituted CDPEs. A fraction of extract prepared from Lake Ontario lake trout which was enriched with CDPEs was embryotoxic to medaka, which indicates that CDPEs may contribute significantly to the toxic burden of halogenated aromatic hydrocarbons in the eggs of wild fish.

  7. Spatial and Temporal Variability of Polycyclic Aromatic Hydrocarbons in Sediments from Yellow River-Dominated Margin

    Directory of Open Access Journals (Sweden)

    Su Ding

    2014-01-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs were analyzed for surface sediments and a sediment core from the Yellow River-dominated margin. The concentration of 16 USEPA priority PAHs in surface sediments ranged from 5.6 to 175.4 ng g−1 dry weight sediment (dws with a mean of 49.1 ng g−1 dws. From 1930 to 2011, the distribution of PAHs (37.2 to 210.6 ng g−1 dws was consistent with the socioeconomic development of China. The PAHs’ concentration peaked in 1964 and 1986, corresponding to the rapid economic growth in China (1958–1965 and the initiation of the “Reform and Open” policy in 1978, respectively. The applications of molecular diagnostic ratios and principal component analysis suggest that PAHs are predominantly produced by the coal and biomass combustion, whereas the contribution of petroleum combustions slightly increased after the 1970s, synchronous with an increasing usage of oil and gas in China.

  8. Chronic Toxicity Of High Molecular Weight Polynuclear Aromatic Hydrocarbon- Pyrene On Freshwater Cyanobacterium Anabaena Fertlissima Rao

    Directory of Open Access Journals (Sweden)

    Jignasha G Patel

    2013-12-01

    Full Text Available The aim of this work was to determine the consequences of Polynuclear aromatic hydrocarbon – Pyrene in response to growth, pigments and metabolic study on Anabaena fertilissima Rao. Test organisms were treated at different doses and encountered LC50 (Lethal concentration at which 50% growth reduction occur concentration separately at 1.5 mg/l, 3.0 mg/l and 6.0 mg/l respectively for Anabaena fertilissima Rao. The influence of Pyrene on growth, pigments, release of metabolites such as carbohydrates, protein, amino acid, phenols was carried out. The test doses caused a concentration dependent decrease in pigments like carotenoids and phycobilliproteins and showed more sensitivity to pyrene. Depletion of carbohydrate by 13% to 81% and proteins by 47% to 93% was encountered with rise in pyrene concentrations after 16th day of exposure. However, phenols were found to rise by 27% to 50% with increased pyrene concentrations on the contrary, amino acids were reported to decline by 79% to 92%. This study therefore suggests high molecular weight pyrene that decreases in metabolite content and enzyme activity can be used as a signal of PAHs toxicity in cyanobacteria. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 175-183 DOI: http://dx.doi.org/10.3126/ije.v2i1.9220

  9. Field application of a genetically engineered microorganism for polycyclic aromatic hydrocarbon bioremediation process monitoring and control

    Energy Technology Data Exchange (ETDEWEB)

    Sayler, G.S.; Cox, C.D.; Ripp, S.; Nivens, D.E.; Werner, C.; Ahn, Y.; Matrubutham, U. [Univ. of Tennessee, Knoxville, TN (United States); Burlage, R. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

    1998-11-01

    On October 30, 1996, the US Environmental Protection Agency (EPA) commenced the first test release of genetically engineered microorganisms (GEMs) for use in bioremediation. The specific objectives of the investigation were multifaceted and include (1) testing the hypothesis that a GEM can be successfully introduced and maintained in a bioremediation process, (2) testing the concept of using, at the field scale, reporter organisms for direct bioremediation process monitoring and control, and (3) acquiring data that can be used in risk assessment decision making and protocol development for future field release applications of GEMs. The genetically engineered strain under investigation is Pseudomonas fluorescens strain HK44 (King et al., 1990). The original P. fluorescens parent strain was isolated from polycyclic aromatic hydrocarbon (PAH) contaminated manufactured gas plant soil. Thus, this bacterium is able to biodegrade naphthalene (as well as other substituted naphthalenes and other PAHs) and is able to function as a living bioluminescent reporter for the presence of naphthalene contamination, its bioavailability, and the functional process of biodegradation. A unique component of this field investigation was the availability of an array of large subsurface soil lysimeters. This article describes the experience associated with the release of a genetically modified microorganism, the lysimeter facility and its associated instrumentation, as well as representative data collected during the first eighteen months of operation.

  10. Distribution of polycyclic aromatic hydrocarbons in water and surface sediments from Daya Bay, China

    International Nuclear Information System (INIS)

    Zhou, J.L.; Maskaoui, K.

    2003-01-01

    Findings indicate an urgent need to establish a monitoring program for persistent organic pollutants in water and sediment. - Marine culture is thriving in China and represents a major component of the regional economy in coastal zones, yet the environmental quality of many of those areas has never been studied. This paper attempts to investigate the quality status of Daya Bay, a key aquaculture area in China. The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in water and sediment samples of the bay. The total concentrations of 16 PAHs varied from 4228 to 29325 ng l -1 in water, and from 115 to 1134 ng g -1 dry weight in sediments. In comparison to many other marine systems studied, the PAH levels in Daya Bay waters were relatively high, and at six sites they were sufficiently high (>10 μg l -1 ) to cause acute toxicity. The PAH composition pattern in sediments suggest dominance by medium to high molecular weight compounds, and the ratio of certain related PAHs indicate important pyrolytic and petrogenic sources. Further analysis showed that the distribution coefficient (K D ) increased with the particular organic carbon content of sediments, consistent with the PAH partition theory. The organic carbon normalised distribution coefficient (K oc ) also increased with the compounds' octanol/water partition coefficient (K ow ), confirming the potential applicability of the linear free energy relationships in the modelling and prediction of PAH behaviour in marine environments

  11. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust

    International Nuclear Information System (INIS)

    Chang, C.-T.; Chen, B.-Y.

    2008-01-01

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5α. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC 50 , was approximately as follows: PAHs > two-stroke engines > four-stroke engines > BTEX

  12. Probabilistic ecological risk assessment of polycyclic aromatic hydrocarbons in southwestern catchments of the Bohai Sea, China.

    Science.gov (United States)

    Zeng, Lin; Zeng, Siyu; Dong, Xin; Zhang, Tianzhu; Chen, Jining

    2013-10-01

    A probability risk assessment was undertaken to study the individual and combined ecological risks induced by six polycyclic aromatic hydrocarbons (PAHs) both in surface water and sediment from southwestern catchments of the Bohai Sea, China. The actual measured PAH concentrations in water and sediment were compared with toxicity effect data (the 10th percentile of predicted no effect concentration) to calculate the risk quotients (RQs) for an individual PAH. The equilibrium partitioning method was applied to estimate toxicity data in sediment. A method based on the equivalent concentration concept was proposed and applied to assess the combined ecological risk of multiple PAHs. Monte Carlo simulation and bootstrap technique were utilized to calculate the distribution of RQs and associated uncertainties. The ecological safety level was defined by RQ ≤ 1. Results indicated that both in water and sediment, fluoranthene and pyrene posed the highest risks, whereas acenaphthene and fluorene posed negligible risks. Naphthalene and phenanthrene did not pose risks to the ecological community in surface water but had relatively higher risks in sediment. The median RQs of combined risk in surface water and sediment were 0.934 and 2.42, and the probabilities of RQ > 1 were up to 0.473 and 0.599, respectively, which were much higher than the individual compound acting alone. The risk level in sediment was quite higher than in surface water probably owing to the non-equilibrium distribution between two phases, which suggested that local authorities should focus more on sediment quality management.

  13. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil

    International Nuclear Information System (INIS)

    Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

    2015-01-01

    Highlights: • A novel metal-immobilizing organoclay (MIOC) synthesized and characterized. • MIOC immobilizes toxic metals and reduces metal bioavailability. • It enhances PAH-bioavailability to soil bacteria. • It improves microbial growth and activities in mixed-contaminated soils. • MIOC facilitates PAH-biodegradation in metal co-contaminated soils. - Abstract: Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad ® 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC > unmodified bentonite > Arquad–bentonite). The MIOC variably increased the microbial count (10–43%) as well as activities (respiration 3–44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils

  14. Polycyclic Aromatic Hydrocarbons in the Dagang Oilfield (China: Distribution, Sources, and Risk Assessment

    Directory of Open Access Journals (Sweden)

    Haihua Jiao

    2015-05-01

    Full Text Available The levels of 16 polycyclic aromatic hydrocarbons (PAHs were investigated in 27 upper layer (0–25 cm soil samples collected from the Dagang Oilfield (China in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1, to oil well areas (mean of 627.3 µg·kg−1, to urban and residential zones (mean of 1856 µg·kg−1. Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B or not classified/non-carcinogenic (NB. The total concentrations of carcinogenic PAHs (∑BPAHs varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

  15. [Pollution characteristics and sources of polycyclic aromatic hydrocarbons in urban rivers of Wenzhou city].

    Science.gov (United States)

    Zhou, Jie-Cheng; Chen, Zhen-Lou; Bi, Chun-Juan; Lü, Jin-Gang; Xu, Shi-Yuan; Pan, Qi

    2012-12-01

    Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) in water and surface sediments collected from the urban rivers of Wenzhou city in spring and summer were measured by GC-MS. The results showed that the total PAHs concentrations in water and sediments of the studied rivers varied in ranges of 146.74-3 047.89 ng x L(-1) and 21.01-11 990.48 ng x g(-1), respectively. Higher concentrations occurred in spring. The low and middle rings of 2-4-ring were dominant in both water and sediments, but the concentrations of 5-ring and 6-ring PAHs in sediments were relatively higher than those in water. The EBaP values of PAHs in water of the studied rivers in spring and summer were 1.69-51.95 ng x L(-1) and 0-3.03 ng x L(-1), respectively. Eighty percent of water samples in spring surpassed the limits of BaP in surface water of China. The concentrations of sigma PAHs in the sediments both in spring and summer were lower than the ERM value, but part of the components of PAHs had values higher than the ERM, suggesting possible toxic effect on living organisms. Based on the PAHs molecule ratios and principal component analysis, a mixed PAHs source of petroleum and combustion in water and sediments was diagnosed, while sediments showed a greater proportion of combustion sources.

  16. Degradation of phenolics, nitrogen-heterocyclics and polynuclear aromatic hydrocarbons in a rotating biological contactor.

    Science.gov (United States)

    Jeswani, Hansa; Mukherji, Suparna

    2012-05-01

    The degradation of phenolics, heterocyclics and polynuclear aromatic hydrocarbons (PAHs) in a synthetic biomass gasifier wastewater with average COD of 1388 mg/L was studied in a three stage rotating biological contactor (RBC) using the pyrene degrader, Exiguobacterium aurantiacum and activated sludge consortia (1:3 v/v). As the organic loading rate (OLR) was varied from 3.3 to 14 g/m(2)/d, the COD removal ranged from 63.3% to 92.6%. Complete removal of all the constituents was observed at the lowest OLR of 3.3g/m(2)/d. At 24h hydraulic retention time (HRT) and OLR of 6.6g/m(2)/d complete removal of pyridine, quinoline and benzene and 85-96% removal of phenol, naphthalene, phenanthrene, fluoranthene and pyrene was observed. E. aurantiacum was found to be the dominant bacteria in the biofilm. Clark's model provided good fits to data for all the three stages of the RBC. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Impact of soil organic matter on the distribution of polycyclic aromatic hydrocarbons (PAHs) in soils.

    Science.gov (United States)

    Yang, Y; Zhang, N; Xue, M; Tao, S

    2010-06-01

    The knowledge on the distribution of hydrophobic organic contaminants in soils can provide better understanding for their fate in the environment. In the present study, the n-butanol extraction and humic fractionation were applied to investigate the impact of SOM on the distribution of polycyclic aromatic hydrocarbons (PAHs). The results indicated that 80.5%-94.8% of the target PAHs could be extracted by n-butanol and 63.1%-94.6% of PAHs were associated with fulvic acid (FA). Concentrations of un-extracted PAHs increased significantly with the increasing soil organic matter (SOM), however, such an association was absent for the extractable fractions. The results suggested that the sequestration played a critical role in the accumulation of PAHs in soils. SOM also retarded the diffusion of PAHs into the humin fractions. It implied that sequestration in SOM was critical for PAH distribution in soils, while the properties of PAH compounds also had great influences. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Impact of vegetation on sedimentary organic matter composition and polycyclic aromatic hydrocarbon attenuation.

    Science.gov (United States)

    Gregory, Samuel T; Shea, Damian; Guthrie-Nichols, Elizabeth

    2005-07-15

    Results from natural and engineered phytoremediation systems provide strong evidencethatvegetated soils mitigate polycyclic aromatic hydrocarbon (PAH) contamination. However, the mechanisms by which PAH mitigation occurs and the impact of plant organic matter on PAH attenuation remain unclear. This study assessed the impact of plant organic matter on PAH attenuation in labile and refractory sediments fractions from a petroleum distillate waste pit that has naturally revegetated. Samples were collected in distinct zones of barren and vegetated areas to assess changes to organic matter composition and PAH content as vegetation colonized and became established in the waste pit. Sediments were fractionated into bulk sediment and humin fractions and analyzed for organic matter composition by isotope ratio mass spectrometry (delta (13)C), 13C nuclear magnetic resonance (13C NMR), delta 14C AMS (accelerator mass spectrometry), and percent organic carbon (%TOC). Gas chromatography mass spectrometry (GC/ MS) of lipid extracts of SOM fractions provided data for PAH distribution histograms, compound weathering ratios, and alkylated and nonalkylated PAH concentrations. Inputs of biogenic plant carbon, PAH weathering, and declines in PAH concentrations are most evidentfor vegetated SOM fractions, particularly humin fractions. Sequestered PAH metabolites were also observed in vegetated humin. These results show that plant organic matter does impact PAH attenuation in both labile and refractory fractions of petroleum distillate waste.

  19. Adsorption of polynuclear aromatic hydrocarbons from aqueous solution: Agrowaste-modified kaolinite vs surfactant modified bentonite

    Directory of Open Access Journals (Sweden)

    E. I. Unuabonah

    2017-01-01

    Full Text Available The adsorption efficiency of a new hybrid clay adsorbent for polynuclear aromatic hydrocarbons (PAHs is compared with known modified clay adsorbents. The new hybrid clay adsorbent (HYCA showed far higher adsorption capacities for the adsorption of various PAH molecules compared with sodium dodecyl sulfate modified and humic acid modified Bentonite clay adsorbents. With the new hybrid clay adsorbent (HYCA, the adsorption of some of the larger PAH molecules was complete in the first 1 h as compared with ≈ 62% and ≈ 76% observed for both humic acid modified and sodium dodecyl sulfate modified Bentonite clay adsorbents respectively. In 24 h adsorption of the PAHs was complete for all adsorbents with HYCA adsorbent showing better efficiency in the removal of the PAH molecules from aqueous solutions. No significant change was observed with increase in time up to 48 h. The adsorption was observed to be more spontaneous with HYCA adsorbent than with either modified Bentonite adsorbents. The enthalpy of adsorption did not follow any specific order and were not consistent for all PAH molecules considered.

  20. Ionization of Gas-Phase Polycyclic Aromatic Hydrocarbons in Electrospray Ionization Coupled with Gas Chromatography.

    Science.gov (United States)

    Cha, Eunju; Jeong, Eun Sook; Han, Sang Beom; Cha, Sangwon; Son, Junghyun; Kim, Sunghwan; Oh, Han Bin; Lee, Jaeick

    2018-03-20

    Herein, gas-phase polycyclic aromatic hydrocarbons (PAHs) as nonpolar compounds were ionized to protonated molecular ions [M + H] + without radical cations and simultaneously analyzed using gas chromatography (GC)/electrospray ionization (ESI)-tandem mass spectrometry (MS/MS). The ionization profile, dissociation, and sensitivity were first investigated to understand the significant behavior of gas-phase PAHs under ESI. The formation of protonated molecular ions of PAHs was distinguished according to the analyte phase and ESI spray solvents. The protonated PAHs exhibited characteristic dissociations, such as H-loss, H 2 -loss, and acetylene-loss, via competition of internal energy. In addition, GC/ESI-MS/MS resulted in relatively lower concentration levels (better sensitivity) for the limits-of-detection (LODs) of PAHs than liquid chromatography (LC)/ESI-MS/MS, and it seems to result from the characteristic ionization mechanism of the gas-phase analyte under ESI. Furthermore, the LODs of gas-phase PAHs depended on molecular weight and proton affinity (PA). Consequently, we demonstrated the relationship among the analyte phases, sensitivities, and structural characteristics (molecular weight and PA) under ESI. The gas-phase PAHs provided enhanced protonation efficiency and sensitivity using GC/ESI-MS/MS, as their molecular weight and PA increased. Based on these results, we offered important information regarding the behavior of gas-phase analytes under ESI. Therefore, the present GC/ESI-MS/MS method has potential as an alternative method for simultaneous analysis of PAHs.