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Sample records for aromatic hydrocarbons based

  1. Optimization and determination of polycyclic aromatic hydrocarbons in biochar-based fertilizers.

    Science.gov (United States)

    Chen, Ping; Zhou, Hui; Gan, Jay; Sun, Mingxing; Shang, Guofeng; Liu, Liang; Shen, Guoqing

    2015-03-01

    The agronomic benefit of biochar has attracted widespread attention to biochar-based fertilizers. However, the inevitable presence of polycyclic aromatic hydrocarbons in biochar is a matter of concern because of the health and ecological risks of these compounds. The strong adsorption of polycyclic aromatic hydrocarbons to biochar complicates their analysis and extraction from biochar-based fertilizers. In this study, we optimized and validated a method for determining the 16 priority polycyclic aromatic hydrocarbons in biochar-based fertilizers. Results showed that accelerated solvent extraction exhibited high extraction efficiency. Based on a Box-Behnken design with a triplicate central point, accelerated solvent extraction was used under the following optimal operational conditions: extraction temperature of 78°C, extraction time of 17 min, and two static cycles. The optimized method was validated by assessing the linearity of analysis, limit of detection, limit of quantification, recovery, and application to real samples. The results showed that the 16 polycyclic aromatic hydrocarbons exhibited good linearity, with a correlation coefficient of 0.996. The limits of detection varied between 0.001 (phenanthrene) and 0.021 mg/g (benzo[ghi]perylene), and the limits of quantification varied between 0.004 (phenanthrene) and 0.069 mg/g (benzo[ghi]perylene). The relative recoveries of the 16 polycyclic aromatic hydrocarbons were 70.26-102.99%.

  2. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    Science.gov (United States)

    Mahler, B.J.; Van Metre, P.C.

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  3. 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.

  4. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  5. Kekulé-based Valence Bond Model.Ⅱ. Diels-Alder Reactivity of Polycyclic Aromatic Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    MA,Jing(马晶); LI,Shu-Hua(黎书华); JIANG,Yuan-Sheng(江元生)

    2002-01-01

    The Kekule-based valence bond ( VB ) method was employed to study the ground state properties of 52 polycyclic aromatic hydrocarbons. The reactivity indices defined upon our VB calculations were demonstrated to be capable of quantitatively interpreting the secnd order rate constants of the Diels-Alder reactions. The qualitative trends of the reactivities of many homologous series can be also explained based on the local aromaticity index defined in this work.

  6. Potentiometric online detection of aromatic hydrocarbons in aqueous phase using carbon nanotube-based sensors.

    Science.gov (United States)

    Washe, Alemayehu P; Macho, Santiago; Crespo, Gastón A; Rius, F Xavier

    2010-10-01

    Surfaces made of entangled networks of single-walled carbon nanotubes (SWCNTs) display a strong adsorption affinity for aromatic hydrocarbons. Adsorption of these compounds onto the walls of SWCNTs changes the electrical characteristics of the SWCNT-solution interface. Using these features, we have developed a potentiometric sensor to detect neutral aromatic species. Specifically, we can detect online aromatic hydrocarbons in industrial coolant water. Our chromatographic results confirm the adsorption of toluene onto the walls of carbon nanotubes, and our impedance spectroscopy data show the change in the double layer capacitance of the carbon nanotube-solution interface upon addition of toluene, thus confirming the proposed sensing mechanism. The sensor showed a toluene concentration dependent EMF response that follows the shape of an adsorption isotherm and displayed an immediate response to the presence of toluene with a detection limit of 2.1 ppm. The sensor does not respond to other nonaromatic hydrocarbons that may coexist with aromatic hydrocarbons in water. It shows a qualitative sensitivity and selectivity of 100% and 83%, respectively, which confirms its ability to detect aromatic hydrocarbons in aqueous solutions. The sensor showed an excellent ability to immediately detect the presence of toluene in actual coolant water. Its operational characteristics, including its fast response, low cost, portability, and easy use in online industrial applications, improve those of current chromatographic or spectroscopic techniques.

  7. A DFT-based toxicity QSAR study of aromatic hydrocarbons to Vibrio fischeri: Consideration of aqueous freely dissolved concentration.

    Science.gov (United States)

    Wang, Ying; Yang, Xianhai; Wang, Juying; Cong, Yi; Mu, Jingli; Jin, Fei

    2016-05-05

    In the present study, quantitative structure-activity relationship (QSAR) techniques based on toxicity mechanism and density functional theory (DFT) descriptors were adopted to develop predictive models for the toxicity of alkylated and parent aromatic hydrocarbons to Vibrio fischeri. The acute toxicity data of 17 aromatic hydrocarbons from both literature and our experimental results were used to construct QSAR models by partial least squares (PLS) analysis. With consideration of the toxicity process, the partition of aromatic hydrocarbons between water phase and lipid phase and their interaction with the target biomolecule, the optimal QSAR model was obtained by introducing aqueous freely dissolved concentration. The high statistical values of R(2) (0.956) and Q(CUM)(2) (0.942) indicated that the model has good goodness-of-fit, robustness and internal predictive power. The average molecular polarizability (α) and several selected thermodynamic parameters reflecting the intermolecular interactions played important roles in the partition of aromatic hydrocarbons between the water phase and biomembrane. Energy of the highest occupied molecular orbital (E(HOMO)) was the most influential descriptor which dominated the toxicity of aromatic hydrocarbons through the electron-transfer reaction with biomolecules. The results demonstrated that the adoption of freely dissolved concentration instead of nominal concentration was a beneficial attempt for toxicity QSAR modeling of hydrophobic organic chemicals.

  8. A novel dual-LED based long-path DOAS instrument for the measurement of aromatic hydrocarbons

    Science.gov (United States)

    Stutz, Jochen; Hurlock, Stephen C.; Colosimo, Santo F.; Tsai, Catalina; Cheung, Ross; Festa, James; Pikelnaya, Olga; Alvarez, Sergio; Flynn, James H.; Erickson, Matthew H.; Olaguer, Eduardo P.

    2016-12-01

    Aromatic hydrocarbons are well known air toxics which are regulated by the US EPA and other air quality agencies. Accurate, long-term monitoring of these compounds at low part-per-billion levels, as well as identifying emission point sources is therefore crucial to protect human health in neighborhoods near large emission sources. Here we present a new long-path differential optical absorption spectroscopy (LP-DOAS) instrument specifically designed to monitor aromatic hydrocarbons. The system is based on a novel dual - light emitting diode (LED) light source, which eliminates the requirement to suppress spectrometer stray light. This light source, together with a high stability fiber-based sending/receiving telescope, allows the measurement of aromatic hydrocarbons on once-folded absorptions paths of 200-1200 m length. The new instrument shows very good agreement with simultaneous in-situ measurements if inhomogeneities of the trace gas spatial distributions are considered. The new instrument performed well during a three-month field test as an automated fence-line monitor at a refinery, successfully distinguishing upwind background levels of ∼1 ppb from emissions reflected in elevated mixing ratios of 3-4 ppb. A two-dimensional measurement network based on two identical LP-DOAS instruments operating on seven crossed light paths was operated successfully in Houston, TX. Qualitative and quantitative analysis of two events with toluene and xylene plumes demonstrate how this setup can be used to derive the spatial distribution of aromatic hydrocarbons, and identify point sources.

  9. Field effect transistors based on polycyclic aromatic hydrocarbons for the detection and classification of volatile organic compounds.

    Science.gov (United States)

    Bayn, Alona; Feng, Xinliang; Müllen, Klaus; Haick, Hossam

    2013-04-24

    We show that polycyclic aromatic hydrocarbon (PAH) based field effect transistor (FET) arrays can serve as excellent chemical sensors for the detection of volatile organic compounds (VOCs) under confounding humidity conditions. Using these sensors, w/o complementary pattern recognition methods, we study the ability of PAH-FET(s) to: (i) discriminate between aromatic and non-aromatic VOCs; (ii) distinguish polar and non-polar non-aromatic compounds; and to (iii) identify specific VOCs within the subgroups (i.e., aromatic compounds, polar non-aromatic compounds, non-polar non-aromatic compounds). We further study the effect of water vapor on the sensor array's discriminative ability and derive patterns that are stable when exposed to different constant values of background humidity. Patterns based on different independent electronic features from an array of PAH-FETs may bring us one step closer to creating a unique fingerprint for individual VOCs in real-world applications in atmospheres with varying levels of humidity.

  10. 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.

  11. Emission characteristics of polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons from diesel trucks based on on-road measurements

    Science.gov (United States)

    Cao, Xinyue; Hao, Xuewei; Shen, Xianbao; Jiang, Xi; Wu, Bobo; Yao, Zhiliang

    2017-01-01

    Polycyclic aromatic hydrocarbon (PAH) and nitro-polycyclic aromatic hydrocarbon (NPAH) emissions from 18 diesel trucks of different sizes and with different emission standards were tested in Beijing using a portable emission measurement system (PEMS). Both the gaseous- and particulate-phase PAHs and NPAHs were quantified by high-performance liquid chromatography (HPLC) in the laboratory. The emission factors (EFs) of the total PAHs from light-duty diesel trucks (LDDTs), medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs) were 82229.11 ± 41906.06, 52867.43 ± 18946.47 and 93837.35 ± 32193.14 μg/km, respectively, much higher than the respective values of total NPAHs from their counterpart vehicles. The gaseous phase had an important contribution to the total PAHs and NPAHs, with a share rate of approximately 69% and 97% on average, respectively. The driving cycle had important impacts on the emissions of PAHs and NPAHs, especially for LDDTs and HDDTs. Higher emissions of PAHs and NPAHs were detected on non-highway roads compared to that on highways for these two types of vehicles. Compared to the results of different studies, the difference in the EFs of PAHs and NPAHs can reach several orders of magnitudes, which would introduce errors in the development of an emission inventory of PAHs and NPAHs.

  12. Deuterated polycyclic aromatic hydrocarbons: Revisited

    CERN Document Server

    Doney, Kirstin D; Mori, Tamami; Onaka, Takashi; Tielens, A G G M

    2016-01-01

    The amount of deuterium locked up in polycyclic aromatic hydrocarbons (PAHs) has to date been an uncertain value. We present a near-infrared (NIR) spectroscopic survey of HII regions in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC) obtained with AKARI, which aims to search for features indicative of deuterated PAHs (PAD or Dn-PAH) to better constrain the D/H ratio of PAHs. Fifty-three HII regions were observed in the NIR (2.5-5 {\\mu}m), using the Infrared Camera (IRC) on board the AKARI satellite. Through comparison of the observed spectra with a theoretical model of deuterated PAH vibrational modes, the aromatic and (a)symmetric aliphatic C-D stretch modes were identified. We see emission features between 4.4-4.8 {\\mu}m, which could be unambiguously attributed to deuterated PAHs in only six of the observed sources, all of which are located in the Milky Way. In all cases, the aromatic C-D stretching feature is weaker than the aliphatic C-D stretching feature, and, in the case o...

  13. 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.

  14. Color encoded microbeads-based flow cytometric immunoassay for polycyclic aromatic hydrocarbons in food

    Energy Technology Data Exchange (ETDEWEB)

    Meimaridou, Anastasia, E-mail: anastasia.meimaridou@wur.nl [RIKILT-Institute of Food Safety, Wageningen UR, P.O. Box 230, 6700 AE Wageningen (Netherlands); Haasnoot, Willem; Noteboom, Linda; Mintzas, Dimitrios [RIKILT-Institute of Food Safety, Wageningen UR, P.O. Box 230, 6700 AE Wageningen (Netherlands); Pulkrabova, Jana; Hajslova, Jana [Department of Food Chemistry and Analysis, Institute of Chemical Technology Prague, Technicka 3, 166 28 Prague 6 (Czech Republic); Nielen, Michel W.F. [RIKILT-Institute of Food Safety, Wageningen UR, P.O. Box 230, 6700 AE Wageningen (Netherlands); Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen (Netherlands)

    2010-07-05

    Food contamination caused by chemical hazards such as persistent organic pollutants (POPs) is a worldwide public health concern and requires continuous monitoring. The chromatography-based analysis methods for POPs are accurate and quite sensitive but they are time-consuming, laborious and expensive. Thus, there is a need for validated simplified screening tools, which are inexpensive, rapid, have automation potential and can detect multiple POPs simultaneously. In this study we developed a flow cytometry-based immunoassay (FCIA) using a color-encoded microbeads technology to detect benzo[a]pyrene (BaP) and other polycyclic aromatic hydrocarbons (PAHs) in buffer and food extracts as a starting point for the future development of rapid multiplex assays including other POPs in food, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). A highly sensitive assay for BaP was obtained with an IC{sub 50} of 0.3 {mu}g L{sup -1} using a monoclonal antibody (Mab22F12) against BaP, similar to the IC{sub 50} of a previously described enzyme-linked immunosorbent assay (ELISA) using the same Mab. Moreover, the FCIA was 8 times more sensitive for BaP compared to a surface plasmon resonance (SPR)-based biosensor immunoassay (BIA) using the same reagents. The selectivity of the FCIAs was tested, with two Mabs against BaP for 25 other PAHs, including two hydroxyl PAH metabolites. Apart from BaP, the FCIAs can detect PAHs such as indenol[1,2,3-cd]pyrene (IP), benz[a]anthracene (BaA), and chrysene (CHR) which are also appointed by the European Food Safety Authority (EFSA) as suitable indicators of PAH contamination in food. The FCIAs results were in agreement with those obtained with gas chromatography-mass spectrometry (GC-MS) for the detection of PAHs in real food samples of smoked carp and wheat flour and has great potential for the future routine application of this assay in a simplex or multiplex format in combination with simplified extraction

  15. Volatilisation of aromatic hydrocarbons from soil

    DEFF Research Database (Denmark)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons were measured in the laboratory from the surface of soils contaminated with coal tar Four soil samples from a former gasworks site were used for the experiments. The fluxes were quantified for 11 selected compounds, 4 mono- and 7 polycyclic...... aromatic hydrocarbons, for a period of up to 8 or 16 days. The concentrations of the selected compounds in the soils were between 0.2 and 3,100 mu g/g. The study included the experimental determination of the distribution coefficient of the aromatic hydrocarbons between the sorbed phase and the water under...... saturated conditions. The determined distribution coefficients showed that the aromatic hydrocarbons were more strongly sorbed to the total organic carbon including the coal tar pitch - by a factor of 8 to 25 - than expected for natural organic matter. The fluxes were also estimated using an analytical...

  16. Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

    2000-01-01

    We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

  17. A DFT-based investigation of hydrogen abstraction reactions from methylated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Hemelsoet, Karen; Van Speybroeck, Veronique; Waroquier, Michel

    2008-11-10

    The growth of polycyclic aromatic hydrocarbons (PAHs) is in many areas of combustion and pyrolysis of hydrocarbons an inconvenient side effect that warrants an extensive investigation of the underlying reaction mechanism, which is known to be a cascade of radical reactions. Herein, the focus lies on one of the key reaction classes within the coke formation process: hydrogen abstraction reactions induced by a methyl radical from methylated benzenoid species. It has been shown previously that hydrogen abstractions determine the global PAH formation rate. In particular, the influence of the polyaromatic environment on the thermodynamic and kinetic properties is the subject of a thorough exploration. Reaction enthalpies at 298 K, reaction barriers at 0 K, rate constants, and kinetic parameters (within the temperature interval 700-1100 K) are calculated by using B3LYP/6-31+G(d,p) geometries and BMK/6-311+G(3df,2p) single-point energies. This level of theory has been validated with available experimental data for the abstraction at toluene. The enhanced stability of the product benzylic radicals and its influence on the reaction enthalpies is highlighted. Corrections for tunneling effects and hindered (or free) rotations of the methyl group are taken into account. The largest spreading in thermochemical and kinetic data is observed in the series of linear acenes, and a normal reactivity-enthalpy relationship is obtained. The abstraction of a methyl hydrogen atom at one of the center rings of large methylated acenes is largely preferred. Geometrical and electronic aspects lie at the basis of this striking feature. Comparison with hydrogen abstractions leading to arylic radicals is also made.

  18. Polycyclic aromatic hydrocarbons connected with Schiff base linkers: Experimental and theoretical photophysical characterization and electrochemical properties

    Science.gov (United States)

    Sęk, Danuta; Siwy, Mariola; Małecki, Jan Grzegorz; Kotowicz, Sonia; Golba, Sylwia; Nowak, Elżbieta M.; Sanetra, Jerzy; Schab-Balcerzak, Ewa

    2017-03-01

    A series of polyaromatic hydrocarbons with anthracene, phenanthrene and pyrene units connected with Schiff base junctions were synthesized via condensation of p-phenylenediamine and hydrazine with selected aldehydes. The effect of both hydrocarbon structures and presence of N-N- or phenyl- linked diimines on properties of the prepared azines and azomethines was analyzed. The obtained compounds were soluble in common organic solvents and melted in the range of 226-317 °C. Their photophysical and electrochemical properties were investigated by UV-vis, photoluminescence spectroscopies and cyclic voltammetry (CV), respectively. Moreover, a density functional theory (DFT) was applied for calculation of their electronic and geometric structures as well as absorption and emission spectra. Additionally, their electron acceptor activity was preliminary tested in photovoltaic experiment.

  19. 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...

  20. Investigation of the impacts of ethyl lactate based Fenton treatment on soil quality for polycyclic aromatic hydrocarbons (PAHs)-contaminated soils.

    Science.gov (United States)

    Gan, Suyin; Yap, Chiew Lin; Ng, Hoon Kiat; Venny

    2013-11-15

    This study aims to investigate the impacts of ethyl lactate (EL) based Fenton treatment on soil quality for polycyclic aromatic hydrocarbons (PAHs)-contaminated soils. Accumulation of oxygenated-polycyclic aromatic hydrocarbons (oxy-PAHs) was observed, but quantitative measurement on the most abundant compound 9,10-anthraquinone (ATQ) showed lower accumulation of the compound than that reported for ethanol (ET) based Fenton treatment. In general, as compared to conventional water (CW) based Fenton treatment, the EL based Fenton treatment exerted either a lower or higher negative impact on soil physicochemical properties depending on the property type and shared the main disadvantage of reduced soil pH. For revegetation, EL based Fenton treatment was most appropriately adopted for soil with native pH >/~ 6.2 in order to obtain a final soil pH >/~ 4.9 subject to the soil buffering capacity.

  1. Studies of Polycyclic Aromatic Hydrocarbons in Dungeness Crabs: Biomonitoring, Physiologically Based Toxicokinetic Model, and Human Health Risk Assessment

    OpenAIRE

    Eickhoff, Curtis

    2004-01-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants released into the environment from the incomplete combustion of organic material and petrochemical sources. PAH are persistent molecules that partition into sediments and biota in the aquatic environment. PAH such as benzo[a]pyrene, are of concern because they are metabolised into potentially carcinogenic chemicals that can cause tumours in fish and mammals. The purpose of this research was three-fold, (1) to explore the use of ...

  2. 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...

  3. Assessment of the aryl hydrocarbon receptor-mediated activities of polycyclic aromatic hydrocarbons in a human cell-based reporter gene assay.

    Science.gov (United States)

    Vondráček, Jan; Pěnčíková, Kateřina; Neča, Jiří; Ciganek, Miroslav; Grycová, Aneta; Dvořák, Zdeněk; Machala, Miroslav

    2017-01-01

    Activation of the aryl hydrocarbon receptor (AhR)-mediated activity is one of key events in toxicity of polycyclic aromatic hydrocarbons (PAHs). Although various classes of AhR ligands may differentially activate human and rodent AhR, there is presently a lack of data on the human AhR-inducing relative potencies (REPs) of PAHs. Here, we focused on estimation of the AhR-mediated activities of a large set of environmental PAHs in human gene reporter AZ-AhR cell line, with an aim to develop the human AhR-based REP values with potential implications for risk assessment of PAHs. The previously identified weakly active PAHs mostly failed to activate the AhR in human cells. The order for REPs of individual PAHs in human cells largely corresponded with the available data from rodent-based experimental systems; nevertheless, we identified differences up to one order of magnitude in REP values of PAHs between human and rodent cells. Higher REP values were found in human cells for some important environmental contaminants or suspected carcinogens, such as indeno[1,2,3-cd]pyrene, benz[a]anthracene or benzo[b]fluoranthene, while lower REP values were determined for methyl-substituted PAHs. Our results also indicate that a different rate of metabolism for individual PAHs in human vs. rodent cells may affect estimation of REP values in human cell-based assay, and potentially alter toxicity of some compounds, such as benzofluoranthenes, in humans. We applied the AZ-AhR assay to evaluation of the AhR-mediated activity of complex mixtures of organic compounds associated with diesel exhaust particles, and we identified the polar compounds present in these mixtures as being particularly highly active in human cells, as compared with rodent cells. The present data suggest that differences may exist between the AhR-mediated potencies of PAHs in human and rodent cells, and that the AhR-mediated effects of polar PAH derivatives and metabolites in human cell models deserve further

  4. In situ biodegradation potential of aromatic hydrocarbons in anaerobic groundwaters

    Science.gov (United States)

    Acton, D. W.; Barker, J. F.

    1992-04-01

    Three types of experiments were conducted to assess the potential for enhancing the in situ biodegradation of nine aromatic hydrocarbons in anaerobic, leachate-impacted aquifers at North Bay, Ontario, and at Canada Forces Base Borden. Laboratory micrososms containing authentic aquifer material and groundwater from the North Bay site were amended with nitrate and glucose. No significant losses of aromatic hydrocarbons were observed compared to unamended controls, over a period of 187 days. A total of eight in situ biodegradation columns were installed in the North Bay and Borden aquifers. Remedial additions included electron acceptors (nitrate and sulphate) and primary substrates (acetate, lactate and yeast extract). Six aromatic hydrocarbons [toluene, ethylbenzene, m-xylene, o-xylene, cumene and 1,2,4-trimethylbenzene ( 1,2,4-TMB)] were completely degraded in at least one in situ column at the North Bay site. Only toluene was degraded in the Borden aquifer. In all cases, aromatic hydrocarbon attenuation was attributed to biodegradation by methanogenic and fermentative bacteria. No evidence of aromatic hydrocarbon degradation was observed in columns remediated with nitrate or primary substrates. A continuous forced gradient injection experiment with sulphate addition was conducted at the North Bay site over a period of 51 days. The concentration of six aromatic hydrocarbons was monitored over time in the injection wells and at piezometer fences located 2, 5 and 10 m downgradient. All compounds except toluene reached injection concentration between 14 and 26 days after pumping began, and showed some evidence of selective retardation. Toluene broke through at a subdued concentration (˜ 50% of injection levels), and eventually declined to undetectable levels on day 43. This attenuation was attributed to adaptation and biodegradation by anaerobic bacteria. The results from these experiments indicate that considerable anaerobic biodegradation of aromatic hydrocarbons in

  5. Quantitative structure-activity relationship modeling of polycyclic aromatic hydrocarbon mutagenicity by classification methods based on holistic theoretical molecular descriptors.

    Science.gov (United States)

    Gramatica, Paola; Papa, Ester; Marrocchi, Assunta; Minuti, Lucio; Taticchi, Aldo

    2007-03-01

    Various polycyclic aromatic hydrocarbons (PAHs), ubiquitous environmental pollutants, are recognized mutagens and carcinogens. A homogeneous set of mutagenicity data (TA98 and TA100,+S9) for 32 benzocyclopentaphenanthrenes/chrysenes was modeled by the quantitative structure-activity relationship classification methods k-nearest neighbor and classification and regression tree, using theoretical holistic molecular descriptors. Genetic algorithm provided the selection of the best subset of variables for modeling mutagenicity. The models were validated by leave-one-out and leave-50%-out approaches and have good performance, with sensitivity and specificity ranges of 90-100%. Mutagenicity assessment for these PAHs requires only a few theoretical descriptors of their molecular structure.

  6. Initial microbial degradation of polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Milić Jelena

    2016-01-01

    Full Text Available The group of polycyclic aromatic hydrocarbons (PAHs are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas. [Projekat Ministarstva nauke Republike Srbije, br. III43004

  7. Analysis of saturated and aromatic hydrocarbons migrating from a polyolefin-based hot-melt adhesive into food.

    Science.gov (United States)

    Lommatzsch, Martin; Biedermann, Maurus; Grob, Koni; Simat, Thomas J

    2016-01-01

    Hot-melt adhesives are widely utilised to glue cardboard boxes used as food packaging material. They have to comply with the requirements of Article 3 of the European Framework Regulation for food contact materials (1935/2004). The hot melt raw materials analysed mainly consisted of paraffinic waxes, hydrocarbon resins and polyolefins. The hydrocarbon resins, functioning as tackifiers, were the predominant source of hydrocarbons of sufficient volatility to migrate into dry foods: the 18 hydrocarbon resins analysed contained 8.2-118 g kg(-1) saturated and up to 59 g kg(-1) aromatic hydrocarbons eluted from GC between n-C16 and n-C24, substantially more than the paraffinic waxes and the polyolefins. These tackfier resins, especially the oligomers ≤ C24, have been characterised structurally by GC×GC-MS and (1)H-NMR spectroscopy. Migration into food was estimated using a simulating system with polenta as food simulant, which was verified by the analysis of a commercial risotto rice sample packed in a virgin fibre folding box sealed with a hot melt. About 0.5-1.5% of the potentially migrating substances (between n-C16 and n-C24) of a hot melt were found to be transferred into food under storage conditions, which can result in a food contamination in the order of 1 mg kg(-1) food (depending on the amount of potentially migrating substances from the hot melt, the hot melt surface, amount of food, contact time etc.). Migrates from hot melts are easily mistaken for mineral oil hydrocarbons from recycled cardboard.

  8. Magnetic molecules derived from hydrogenation of Polycyclic Aromatic Hydrocarbons

    CERN Document Server

    Vergés, J A; Louis, E; Pastor-Abia, L; SanFabian, E

    2008-01-01

    Present routes to produce magnetic organic-based materials adopt a common strategy: the use of magnetic species (atoms, polyradicals, etc.) as building blocks. We explore an alternative approach which consists of selective hydrogenation of Polycyclic Aromatic Hydrocarbons. Self-Consistent-Field (SCF) (Hartree-Fock and DFT) and multi-configurational (CISD and MCSCF) calculations on coronene and corannulene, both hexa-hydrogenated, show that the formation of stable high spin species is possible. The spin of the ground states is discussed in terms of the Hund rule and Lieb's theorem for bipartite lattices (alternant hydrocarbons in this case). This proposal opens a new door to magnetism in the organic world.

  9. 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.

  10. 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

  11. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Directory of Open Access Journals (Sweden)

    K. Jaars

    2014-02-01

    Full Text Available 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 pyrometallurgical 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 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 total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. Benzene levels did not exceed local air quality standards. Toluene was the most abundant species, with an annual median concentration of 0.63 ppb. No statistically significant 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

  12. Humic acids-based one-step fabrication of SERS substrates for detection of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Qu, Lu-Lu; Li, Yuan-Ting; Li, Da-Wei; Xue, Jin-Qun; Fossey, John S; Long, Yi-Tao

    2013-03-07

    A facile one-step approach to fabricate substrates for surface-enhanced Raman scattering (SERS) detection of polycyclic aromatic hydrocarbons (PAHs) was explored by reduction of silver nitrate with humic acids (HAs). This simple process readily delivers silver nanoparticles (Ag NPs) decorated with HAs (HAs-Ag NPs), and an average diameter of 50 nm. More importantly, it compares favorably to Ag NPs prepared by the usual sodium citrate method, HAs-Ag NPs show excellent SERS activity for PAHs and display a remarkable capacity to absorb aromatic molecules through presumed π-π stacking interactions. Furthermore, the HAs-Ag NPs displayed good SERS stability, possibly due to the fact that HAs form loose coils or networks around the nanoparticles thus preventing aggregation. The investigation of qualitative and quantitative detection of PAHs on HAs-Ag NPs indicate that different PAHs can be distinguished easily from their discriminant SERS peaks, and the SERS responses exhibited a linear dependence on PAH concentrations over two orders of magnitude, with tens of nM detection limits. In addition, the HAs-Ag NPs performed well in the multicomponent analysis of PAH mixtures by the SERS technique without pre-separation.

  13. Structural Evolution of Interstellar Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Hammonds, Mark; Candian, Alessandra; Mori, Tamami; Usui, Fumihiko; Onaka, Takashi

    2015-08-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are an important reservoir for molecular carbon in the interstellar medium (ISM), and investigations into their chemistry and behaviour may be important to the understanding of how carbon is processed from simple forms into complex prebiotic molecules such as those detected in chondritic meteorites. In this study, infrared astronomical data from AKARI and other observatories are used together with laboratory and theoretical data to study variations in the structure of emitting PAHs in interstellar environments using spectroscopic decomposition techniques and bands arising from carbon-hydrogen bond vibrations at wavelengths from 3 - 14 microns. Results and inferences are discussed in terms of the processing of large carbonaceous molecules in astrophysical environments.

  14. Monitoring of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of southern Luxembourg using XAD-2 resin-based passive samplers.

    Science.gov (United States)

    Schummer, Claude; Appenzeller, Brice M; Millet, Maurice

    2014-02-01

    XAD-2 resin-based passive samplers (PAS) with dimensions adapted to 100 mL accelerated solvent extraction cells were used to study the temporal and spatial variations of 17 PAHs on five sites in the atmosphere of southern Luxembourg. This new design allowed extracting the PAS without emptying the resin from the shelter. PAH analyses were done with gas chromatography-tandem mass spectrometry. PAS were deployed for 1 year with varying sampling periodicities, and 16 PAHs were detected with concentrations ranging from 1 ng/PAS for chrysene to 9,727 ng/PAS for naphthalene. The PAS were found adapted to the monitoring of temporal and spatial variations for lightweight PAHs (up to four aromatic rings) though not for heavy PAHs with five aromatic rings or more, as these compounds are preferably in the particle phase of the atmosphere and the amount of these PAHs trapped on the PAS will be too low.

  15. Concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and Azaarenes in Runoff from Freshly Applied Coal-Tar-Based Pavement Sealcoat

    Science.gov (United States)

    Mahler, B. J.; Van Metre, P. C.

    2013-12-01

    Coal-tar-based sealcoat (CT-sealcoat) is extensively applied to asphalt parking lots and driveways in the U.S. and Canada. Toxicity to fish and invertebrates of runoff from pavement to which CT-sealcoat has been freshly applied has been reported, but relatively little is known about how concentrations of chemicals in runoff change in the hours to days following sealcoat application. We measured the concentrations of 16 U.S. Environmental Protection Agency Priority Pollutant polycyclic aromatic hydrocarbons (PAHs) and 7 azaarenes in 9 samples of simulated runoff from a coal-tar-sealed test plot collected at increasing intervals from 5 hours to 16 weeks following application. Azaarenes, several of which are common constituents in coal-tar pitch, and their oxidized derivatives, azaarones, are an emerging group of little-studied heterocyclic chemicals. Runoff samples were collected by spraying 25 L of a diluted groundwater to 10 m2 on sealed pavement and retrieving the runoff downgradient where the runoff pooled against spill berms. Unfiltered samples were analyzed by GC/MS following liquid-liquid extraction. In the first sample (t=5 hr), phenanthrene had the highest concentration (130 μg/L) among the 16 PAHs. Concentrations of the lower molecular weight (LMW) PAHs (2 and 3 ring) decreased during the 16 weeks following application, and concentrations of the higher molecular weight (HMW) PAHs (4 to 6 ring) increased, coincident with an increase in the concentration of suspended particulates. In the final sample (t=16 weeks), fluoranthene had the highest concentration (36 μg/L) among the 16 PAHs. Of the azaarenes measured, concentrations of acridine and carbazole (107 and 750 μg/L, respectively) in the initial sample exceeded those of any of the PAHs measured except phenanthrene; acridine and carbazole concentrations decreased over the 5 weeks to <5% of their initial values. Samples of dried sealcoat were analyzed the day of application and 5 weeks later. Samples were

  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. High atmosphere-ocean exchange of semivolatile aromatic hydrocarbons

    Science.gov (United States)

    González-Gaya, Belén; Fernández-Pinos, María-Carmen; Morales, Laura; Méjanelle, Laurence; Abad, Esteban; Piña, Benjamin; Duarte, Carlos M.; Jiménez, Begoña; Dachs, Jordi

    2016-06-01

    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 102-103 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.

  18. 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)

  19. Selection of ionic liquids for the extraction of aromatic hydrocarbons from aromatic/aliphatic mixtures

    NARCIS (Netherlands)

    Meindersma, G. Wytze; Podt, Anita (J.G.); Haan, de André B.

    2005-01-01

    The separation of aromatic hydrocarbons (benzene, toluene, ethyl benzene and xylenes) from C4 to C10 aliphatic hydrocarbon mixtures is challenging since these hydrocarbons have boiling points in a close range and several combinations form azeotropes. In this work, we investigated the separation of t

  20. CHARACTERISTICS OF AROMATIC HYDROCARBONS IN CRUDE OILS

    Institute of Scientific and Technical Information of China (English)

    罗斌杰; 李新宇

    1994-01-01

    Crude oils from different basins in China ,Australia and New Zealand were analyzed to character-ize aromatic hydrocarbons produced in different environments by means of GC/MS .The distributions of some common compounds such as naphthalene, phenanthrene, chrysene,pyrene, fluoranthene, fluorine,dibenzothiophene and dibenzofuran were found to be related to sedimentary environments.Especially the relative contents of fluorenes ,dibenzofurans and dibenzothiophenes can be used to di-vide the oils into three types(1) saline or marine carbonate environment;(2) fresh-brackish water lake;(3) swamp and coal-bearing sequence.A romatic biomarkers (e.g.retene, nor-abietene,derivatives of lupeol and β-amyrin)represent higher plant inpults with respect to the precursors of crude oils. High contents of sulphur-containing compounds like benzothiophene and dibenzothiophene series indicate a reducing sulphur-abundant diagenetic condition .The benzohopane series (C32-C35) was identified both in hypersaline and coal-bearing basins, and it is postulated to be the result of strong bacteria activity.In all the sam-ples, a complete series of alkyl benzenes was analyzed .The similarity of its carbon-number distrbu-tion with that of n-alkanes probably suggests their genetic relationship. The distribution of the methylphenanthrene series reflects the evolution degree of crude oils,MPI holding a positive correlation with C29-sterane 20S/(20S+20R).

  1. 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.

  2. Atmospheric polycyclic aromatic hydrocarbons in Seoul, Korea

    Science.gov (United States)

    Park, Seung S.; Kim, Young J.; Kang, Chang H.

    Daily particulate- and vapor-phase polycyclic aromatic hydrocarbons (PAH) samples were collected at an urban site in Seoul, Korea, during five intensive sampling campaigns between October 1998 and December 1999. PAH samples collected on quartz fiber filters and PUF plugs were first extracted using dichloromethane with ultrasonication and supercritical fluid extraction methods, respectively, and then analyzed by GC/MSD/SIM. Seasonal trends in atmospheric PAH concentrations in the study area were highly influenced by fossil fuel usage for domestic heating, boundary layer height, and air temperature. The relative benzo[a]pyrene amount and particulate organic to elemental carbon ratio calculated from the measurement results suggested that photo-oxidation is not an important factor in the variation of PAH concentrations during the summer sampling periods. Correlation studies between specific PAH of the individual factors identified by principal component factor analysis and meteorological parameters revealed that both temperature and relative humidity gave greater effects on the semi-volatile PAH, PHEN and FLT, rather than on the heavier PAH, B(b+k)F and BghiP.

  3. 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.

  4. Cancer risk assessment of human exposure to polycyclic aromatic hydrocarbons (PAHs) via indoor and outdoor dust based on probit model.

    Science.gov (United States)

    Kang, Yuan; Shao, Dingding; Li, Ning; Yang, Gelin; Zhang, Qiuyun; Zeng, Lixuan; Luo, Jiwen; Zhong, Wenfeng

    2015-03-01

    In the present study, the polycyclic aromatic hydrocarbons (PAHs) in indoor dust and outdoor dust including road and window dust around the traffic road in Hunan Province, China, were sampled and detected. The ∑PAHs in indoor dust ranged from 5007-24,236 ng g(-1), with a median of 14,049 ng g(-1). The ∑PAHs in road dust ranged from 3644-12,875 ng g(-1), with a median of 10,559 ng g(-1). The ∑PAHs in window dust ranged from 803-12,590 ng g(-1), with a median of 5459 ng g(-1). Similar pattern of PAHs was observed in road and window dust except in H3W and H4W samples, which was dominated by naphthalene (Nap), benzo(b+k)fluoranthene (B(b+k)F), phenanthrene (Phe), and fluorine (Fle). Indoor dust showed slightly different PAHs profiles, which was dominated by Nap, fluoranthene (Fla) and Phe. Risk assessment indicated that dermal contact and dust ingestion exposure pathways were more important than the inhalation pathway. Cancer risk of PAHs via dust varied from 2.73 × 10(-8)-8.04 × 10(-6), with a median of 2.06 × 10(-6) for children, and from 2 × 10(-8)-5.89 × 10(-6), with a median of 1.52 × 10(-6) for adult. Probit model showed that 76 and 71 % of samples in the sampling area would result in the risk of children and adult exposure to PAHs via dust higher than the acceptable level (1 × 10(-6)), respectively.

  5. Catalytic activity of in situ synthesized MoWNi sulfides in hydrogenation of aromatic hydrocarbons

    Science.gov (United States)

    Topolyuk, Yu. A.; Maksimov, A. L.; Kolyagin, Yu. G.

    2017-02-01

    MoWNi-sulfide catalysts were obtained in situ by thermal decomposition of metal-polymer precursors based on the copolymers of polymaleic anhydride in a hydrocarbon raw material. The activity of the synthesized catalysts in hydrogenation of bicyclic aromatic hydrocarbons was studied, and the composition and structure of active phase nanoparticles were determined.

  6. Partition of polycyclic aromatic hydrocarbons on organobentonites

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of organobentonites synthesized by exchanging organiccation such as dodecyltri-methylammonium (DTMA),benzyldimethyltetradecylammonium (BDTDA), cetyltrimethyl-ammonium (CTMA), octodeyltrimethylammonium (OTMA) on bentonite. The optimal condition, properties and mechanisms for the organobentonites to sorb phenanthrene, anthracene, naphthalene, acenaphthene in water were investigated in detail. The partition behavior was determined for four polycyclic aromatic hydrocarbons (PAHs), such as naphthalene, phenanthrene, anthracene and acenaphthene, from water to a series of organobentonites. The interlayer spacings and organic carbon contents of organobentonites, removal rate and sorption capacities for organobentonites to treat phenanthrene,anthracene, naphthalene, acenaphthene were correlated to the length of alkyl chains and the amounts of cation surfactant exchanged on Foundation item: the bentonite. Phenanthrene, anthracene, naphthalene, and acenaphthene sorption to organobentonites were characterized by linear isotherms, indicating solute partition between water and the organic phase composed of the large alkyl functional groups of quaternary ammonium cations. PAHs distribution coefficients (Kd)between organobentonites and water were proportional to the organic carbon contents of organobentonites. However, the partition coefficients (Koc) were nearly constants for PAHs in the system of organobentonite-water. The Koc of phenanthrene, anthracene,naphthalene, acenaphthene were 2.621x105, 2.106x105, 2.247x104,5.085x104, respectively. The means Koc values on the organobentonites are about ten to twenty times larger than the values on the soils/sediments, what is significant prerequisite for organobentonite to apply to remediation of pollution soil and groundwater. The sorption mechanism was also evaluated from octanol-water partition coefficients and aqueous solubility of PAHs. The correlations between lgKoc and 1gkow, 1gKoc and 1gS for PAHs in the system of water

  7. Identification of sources of polycyclic aromatic hydrocarbons based on concentrations in soils from two sides of the Himalayas between China and Nepal.

    Science.gov (United States)

    Luo, Wei; Gao, Jiajia; Bi, Xiang; Xu, Lan; Guo, Junming; Zhang, Qianggong; Romesh, Kumar Y; Giesy, John P; Kang, Shichang

    2016-05-01

    To understand distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in the Himalayas, 77 soil samples were collected from the northern side of the Himalayas, China (NSHC), and the southern side of the Himalayas, Nepal (SSHN), based on altitude, land use and possible trans-boundary transport of PAHs driven by wind from Nepal to the Tibetan Plateau, China. Soils from the SSHN had mean PAH concentration greater than those from the NSHC. Greater concentrations of PAHs in soils were mainly distributed near main roads and agricultural and urban areas. PAHs with 2-3 rings were the most abundant PAHs in the soils from the Himalayas. Concentrations of volatile PAHs were significantly and positively correlated with altitude. Simulations of trajectories of air masses indicated that distributions of soil PAH concentrations were associated with the cyclic patterns of the monsoon. PAH emissions from traffic and combustion of biomass or coal greatly contributed to concentrations of PAHs in soils from the Himalayas.

  8. In situ hydrothermal growth of ytterbium-based metal-organic framework on stainless steel wire for solid-phase microextraction of polycyclic aromatic hydrocarbons from environmental samples.

    Science.gov (United States)

    Li, Qiu-Lin; Wang, Xia; Chen, Xiang-Feng; Wang, Ming-Lin; Zhao, Ru-Song

    2015-10-09

    In this paper, we report the use of a porous ytterbium-based metal-organic framework (Yb-MOF) coating material with good thermal stability for the headspace solid-phase microextraction (HS-SPME) of polycyclic aromatic hydrocarbons (PAHs) from environmental samples. The Yb-MOF thin films, grown in situ on stainless steel wire in solution, exhibited high selectivity and sensitivity toward PAHs. Under the optimal conditions, the novel fibers achieved large enrichment factors (130-2288), low limits of detection (0.07-1.67ngL(-1)), and wide range of linearity (10-1000ngL(-1)) for 16 PAHs in the tested samples. The novel fiber was successfully used in the analysis of PAHs in real environmental samples. These results demonstrated that Yb-MOF is a promising coating material for the SPME of PAHs at trace levels from environmental samples.

  9. Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan.

    Science.gov (United States)

    Miki, Shizuho; Uno, Seiichi; Ito, Kazuki; Koyama, Jiro; Tanaka, Hiroyuki

    2014-08-30

    Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995.

  10. Xenoestrogenic gene expression: structural features of active polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Schultz, T Wayne; Sinks, Glendon D

    2002-04-01

    Estrogenicity was assessed using the Saccharomyces cerevisiae-based Lac-Z reporter assay and was reported as the logarithm of the inverse of the 50% molar beta-galactosidase activity (log[EC50(-1)]). In an effort to quantify the relationship between molecular structure of polycyclic aromatic hydrocarbons (PAHs) and estrogenic gene expression, a series of PAHs were evaluated. With noted exceptions, the results of these studies indicate that the initial two-dimensional structural warning for estrogenicity, the superpositioning of a hydroxylated aromatic system on the phenolic A-ring of 17-beta-estradiol, can be extended to the PAHs. This two-dimensional-alignment criterion correctly identified estrogenicity of 22 of the 29 PAHs evaluated. Moreover, the estrogenic potency of these compounds was directly related to the size of the hydrophobic backbone. The seven compounds classified incorrectly by this structural feature were either dihydroxylated naphthalenes or aromatic nitrogen-heterocyclic compounds; all such compounds were false positives. Results with dihydroxylated naphthalenes reveal derivatives that were nonestrogenic when superimposed on the phenolic A-ring of 17-beta-estradiol had the second hydroxyl group in the position of the C-ring or were catechol-like in structure. Structural alerts for nitrogen-heterocyclic compounds must take into account the position of the hydroxyl group and the in-ring nitrogen atom; compounds with the hydroxyl group and nitrogen atom involved with the same ring were observed to be nonactive.

  11. Environmental Behaviors and Toxicities of Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Hayakawa, Kazuichi

    2016-01-01

    Airborne particulate matter (PM) has been collected at four cities in Japan starting in the late 1990s, at five or more major cities in China, Korea and Russia starting in 2001 and at the Noto Peninsula starting in 2004. Nine polycyclic aromatic hydrocarbons (PAHs) and eleven nitropolycyclic aromatic hydrocarbons (NPAHs) were determined by HPLC with fluorescence and chemiluminescence detections, respectively. Annual concentrations of PAHs and NPAHs were in the order, China>Russia≫Korea=Japan, with seasonal change (winter>summer). During the observation period, concentrations of PAHs and NPAHs in Japanese cities significantly decreased but the increases in the PAH concentration were observed in Chinese and Russian cities. Concentrations of PAHs and NPAHs were higher in the Northern China than those in the Southern China. At the Noto peninsula, which is in the main path of winter northwest winds and a year-round jet stream that blow from the Asian continent to Japan, the concentrations were high in winter and low in summer every year. A cluster analysis and back trajectory analysis indicated that PAHs and NPAHs were long-range transported from Northeastern China, where coal burning systems such as coal-heating boilers are considered to be the major contributors of PAHs and NPAHs. A dramatic change in atmospheric concentrations of PAHs and NPAHs in East Asia suggests the rapid and large change of PM2.5 pollution in East Asia. Considering the adverse health effects of PM2.5, continuous monitoring of atmospheric PAHs and NPAHs is necessary in this area.

  12. Closed-Shell Polycyclic Aromatic Hydrocarbon Cations: A New Category of Interstellar Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Hudgins, Douglas M.; Bauschlicher, Charles W., Jr.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Density functional theory has been employed to calculate the harmonic frequencies and intensities of a range of polycyclic aromatic hydrocarbon (PAH) cations that explore both size and electronic structure effects of the infrared spectroscopic properties of these species. The sample extends the size range of PAH species considered to more than 50 carbon atoms and includes several representatives from each of two heretofore unexplored categories of PAH cations: (1) fully benzenoid PAH cations whose carbon skeleton is composed of an odd number of carbon atoms (C(sub odd) PAHs); and (2) protonated PAH cations (HPAH+). Unlike the radical electronic structures of the PAH cations that have been the subject of previous theoretical and experimental work, the species in these two classes have a closed-shell electronic configuration. The calculated spectra of circumcoronene, C54H18 in both neutral and (radical) cationic form are also reported and compared with those of the other species. Overall, the C(sub odd) PAHs spectra are dominated by strong CC stretching modes near 1600 cm(exp -1) and display spectra that are remarkably insensitive to molecular size. The HPAH+ species evince a more complex spectrum consistent with the added contributions of aliphatic modes and their generally lower symmetry. Finally, for both classes of closed-shell cations, the intensity of the aromatic CH stretching modes is found to increase with molecular size far out of proportion with the number of CH groups, approaching a value more typical of neutral PAHs for the largest species studied.

  13. Spliced leader-based analyses reveal the effects of polycyclic aromatic hydrocarbons on gene expression in the copepod Pseudodiaptomus poplesia.

    Science.gov (United States)

    Zhuang, Yunyun; Yang, Feifei; Xu, Donghui; Chen, Hongju; Zhang, Huan; Liu, Guangxing

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic and carcinogenic pollutants that can adversely affect the development, growth and reproduction of marine organisms including copepods. However, knowledge on the molecular mechanisms regulating the response to PAH exposure in marine planktonic copepods is limited. In this study, we investigated the survival and gene expression of the calanoid copepod Pseudodiaptomus poplesia upon exposure to two PAHs, 1, 2-dimethylnaphthalene (1, 2-NAPH) and pyrene. Acute toxicity responses resulted in 96-h LC50 of 788.98μgL(-1) and 54.68μgL(-1) for 1, 2-NAPH and pyrene, respectively. Using the recently discovered copepod spliced leader as a primer, we constructed full-length cDNA libraries from copepods exposed to sublethal concentrations and revealed 289 unique genes of diverse functions, including stress response genes and novel genes previously undocumented for this species. Eighty-three gene families were specifically expressed in PAH exposure libraries. We further analyzed the expression of seven target genes by reverse transcription-quantitative PCR in a time-course test with three sublethal concentrations. These target genes have primary roles in detoxification, oxidative defense, and signal transduction, and include different forms of glutathione S-transferase (GST), glutathione peroxidases (GPX), peroxiredoxin (PRDX), methylmalonate-semialdehyde dehydrogenase (MSDH) and ras-related C3 botulinum toxin substrate (RAC1). Expression stability of seven candidate reference genes were evaluated and the two most stable ones (RPL15 and RPS20 for 1, 2-NAPH exposure, RPL15 and EF1D for pyrene exposure) were used to normalize the expression levels of the target genes. Significant upregulation was detected in GST-T, GST-DE, GPX4, PRDX6 and RAC1 upon 1, 2-NAPH exposure, and GST-DE and MSDH upon pyrene exposure. These results indicated that the oxidative stress was induced and that signal transduction might be affected by PAH

  14. Environmental Remediation: Removal of polycyclic aromatic hydrocarbons Dissertation

    OpenAIRE

    Nkansah, Marian Asantewah

    2012-01-01

    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 refi...

  15. Exposure of iron foundry workers to polycyclic aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Omland, Øyvind; Sherson, D; Hansen, Åse Marie

    1994-01-01

    Exposure to polycyclic aromatic hydrocarbons (PAHs) in foundry workers has been evaluated by determination of benzo(a)pyrene-serum albumin adducts and urinary 1-hydroxypyrene. Benzo(a)pyrene binding to albumin and 1-hydroxypyrene were quantitatively measured by enzyme linked immunosorbent assay...... than in smoking and non-smoking controls (0 (0-0.022) and 0 (0-0.010) mumol/mol creatinine). Dose-response relations between total PAH, pyrene, carcinogenic PAHs, and 1-hydroxypyrene for smokers, and polycyclic aromatic hydrocarbons adsorbed to dust for non-smokers are suggested. Exposure to PAHs...

  16. 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...

  17. Comments on Coulomb pairing in aromatic hydrocarbons

    CERN Document Server

    Huber, D L

    2013-01-01

    Recently reported anomalies in the double-photonionization spectra of aromatic molecules such as benzene, naphthalene, anthracene and coronene are attributed to Coulomb-pair resonances of pi electrons.

  18. Determination of the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants.

    Science.gov (United States)

    Uematsu, Yoko; Suzuki, Kumi; Ogimoto, Mami

    2016-01-01

    A method was developed to determine the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants; a survey was also conducted of commercial lubricants. Hydrocarbons in lubricants were separated from the matrix components of lubricants using a silica gel solid phase extraction (SPE) column. Normal-phase liquid chromatography (NPLC) coupled with an evaporative light-scattering detector (ELSD) was used to determine the aromatic hydrocarbon to total hydrocarbon ratio. Size exclusion chromatography (SEC) coupled with a diode array detector (DAD) and a refractive index detector (RID) was used to estimate carbon numbers and the presence of aromatic hydrocarbons, which supplemented the results obtained by NPLC/ELSD. Aromatic hydrocarbons were not detected in 12 lubricants specified for use for incidental food contact, but were detected in 13 out of 22 lubricants non-specified for incidental food contact at a ratio up to 18%. They were also detected in 10 out of 12 lubricants collected at food factories at a ratio up to 13%. The centre carbon numbers of hydrocarbons in commercial lubricants were estimated to be between C16 and C50.

  19. 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.

  20. Trace level determination of polycyclic aromatic hydrocarbons in river water with automated pretreatment HPLC.

    Science.gov (United States)

    Watabe, Yoshiyuki; Kubo, Takuya; Tanigawa, Tetsuya; Hayakawa, Yoshihiro; Otsuka, Koji; Hosoya, Ken

    2013-03-01

    A novel on-line pretreatment pump-injection HPLC system for polycyclic aromatic hydrocarbons is proposed. We report novel pump-injection HPLC-based on-line SPE with a specially designed pretreatment column for the determination of trace amounts of chemical substances in surface water. Polycyclic aromatic hydrocarbons are well known for strong carcinogenicity and thus a severe concentration control is required for drinking water and/or river water, which is the main resource of tap water. We found it possible to detect ng/L levels of polycyclic aromatic hydrocarbons by using pump-injection column switching HPLC with fluorescence detection. To avoid the phenomenon, in which polycyclic aromatic hydrocarbons can be often adsorbed on the surface of flow lines of HPLC by their highly hydrophobicity especially resin-made parts in sample delivery pump, we employed "autodilution" device that provides reliable recovery and repeatability. Additionally, real water samples were collected and then the spiked polycyclic aromatic hydrocarbons were determined at ng/L levels.

  1. CYP1A1 genetic polymorphism and polycyclic aromatic hydrocarbons on pulmonary function in the elderly: haplotype-based approach for gene-environment interaction.

    Science.gov (United States)

    Choi, Yoon-Hyeong; Kim, Jin Hee; Hong, Yun-Chul

    2013-08-29

    Lung function may be impaired by environmental pollutants not only acting alone, but working with genetic factors as well. Few epidemiologic studies have been conducted to explore the interplay of polycyclic aromatic hydrocarbons (PAHs) exposure and genetic polymorphism on lung function in the elderly. For genetic polymorphism, haplotype is considered a more informative unit than single nucleotide polymorphism markers. Therefore, we examined the role of haplotype based-CYP1A1 polymorphism in the effect of PAHs exposure on lung function in 422 participants from a community-based panel of elderly adults in Seoul, Korea. Linear mixed effect models were fit to evaluate the association of PAH exposure markers (urinary 1-hydroxypyrene and 2-naphthol) with FVC, FEV₁, FEV₁/FVC, and FEF₂₅₋₇₅, and then the interaction with CYP1A1 haplotype constructed from three single nucleotide polymorphisms of the gene (rs4646421/rs4646422/rs1048943). Urinary 1-hydroxypyrene levels were inversely associated with FEV₁/FVC (ppolymorphisms on lung functions. Our findings suggest that PAH exposure producing 1-hydroxypyrene as a metabolite compromises lung function in the elderly, and that haplotype-based CYP1A1 polymorphism modifies the risk.

  2. A highly sensitive monoclonal antibody based biosensor for quantifying 3–5 ring polycyclic aromatic hydrocarbons (PAHs in aqueous environmental samples

    Directory of Open Access Journals (Sweden)

    Xin Li

    2016-03-01

    Full Text Available Immunoassays based on monoclonal antibodies (mAbs are highly sensitive for the detection of polycyclic aromatic hydrocarbons (PAHs and can be employed to determine concentrations in near real-time. A sensitive generic mAb against PAHs, named as 2G8, was developed by a three-step screening procedure. It exhibited nearly uniformly high sensitivity against 3-ring to 5-ring unsubstituted PAHs and their common environmental methylated PAHs, with IC50 values between 1.68 and 31 μg/L (ppb. 2G8 has been successfully applied on the KinExA Inline Biosensor system for quantifying 3–5 ring PAHs in aqueous environmental samples. PAHs were detected at a concentration as low as 0.2 μg/L. Furthermore, the analyses only required 10 min for each sample. To evaluate the accuracy of the 2G8-based biosensor, the total PAH concentrations in a series of environmental samples analyzed by biosensor and GC–MS were compared. In most cases, the results yielded a good correlation between methods. This indicates that generic antibody 2G8 based biosensor possesses significant promise for a low cost, rapid method for PAH determination in aqueous samples.

  3. Interactions of polyhalogeneted 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 the inhi

  4. 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...

  5. Bioavailability of Polycyclic Aromatic Hydrocarbons in Soils and Sediments

    NARCIS (Netherlands)

    Cuypers, M.P.

    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 contamin

  6. 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...

  7. Integrated Environmental Quality Objectives for Polycyclic Aromatic Hydrocarbons (PAHs)

    NARCIS (Netherlands)

    Kalf DF; Crommentuijn GH; Posthumus R; Plassche EJ van de; ACT

    1995-01-01

    In the present report Maximum Permissible Concentrations (MPCs) are derived for 10 Polycyclic Aromatic Hydrocarbons (PAHs). For the aquatic environment MPCs are derived from the available experimental data. For 3 PAHs no experimental data are available. These MPCs are calculated using the QSAR-appro

  8. THE RATES OF POLYCYCLIC AROMATIC HYDROCARBON EMISSIONS FROM INCENSE BURNING

    Science.gov (United States)

    The paper presents the results of experiments performed to determine the amounts of gas- and particle-phase polycyclic aromatic hydrocarbons (PAHS) in incense smoke. Ten brands of incense, 3 of stick, 2 of joss stick, and one each of cone, smudge bundle, rope, powder, and rock, w...

  9. Polycyclic aromatic hydrocarbons in soils around Guanting Reservoir, Beijing, China

    NARCIS (Netherlands)

    Jiao, W.T.; Lu, Y.L.; Wang, T.Y.; Li, J.; Han, Jingyi; Wang, G.; Hu, W.Y.

    2009-01-01

    The concentrations of 16 polycyclic aromatic hydrocarbons ( 16PAHs) were measured by gas chromatography equipped with a mass spectrometry detector (GC-MS) in 56 topsoil samples around Guanting Reservior (GTR), which is an important water source for Beijing. Low to medium levels of PAH contamination

  10. 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.

  11. Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils

    Science.gov (United States)

    Braddock, J.F.

    1999-01-01

    A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.

  12. Preconcentration and fluorimetric determination of polycyclic aromatic hydrocarbons based on the acid-induced cloud-point extraction with sodium dodecylsulfate

    Energy Technology Data Exchange (ETDEWEB)

    Goryacheva, Irina Yu.; Shtykov, Sergei N.; Loginov, Alexander S.; Panteleeva, Irina V. [Saratov State University, Chemistry Department, Saratov (Russian Federation)

    2005-07-01

    The acid-induced cloud-point extraction (CPE) technique based on sodium dodecylsulfate (SDS) micelles has been used for preconcentration of ten representatives of polycyclic aromatic hydrocarbons (PAHs) for the following fluorescence determination. The effect of the acidity of solution, SDS and electrolyte concentrations, centrifugation time and rate on the two-phase separation process and extraction percentages of PAHs have systematically been examined. Extraction percentages have been obtained for all PAHs after CPE ranged from 67 to 93%. Pyrene was used as a fluorescent probe to monitor the micropolarity of the surfactant-rich phase compared with SDS micelles and this allows one to conclude that water content in micellar phase after CPE is reduced. The spectral, metrological and analytical characteristics of PAH fluorimetric determination after acid-based CPE with sodium dodecylsulfate are presented. Advantages provided by using CPE in combination with fluorimetric determination of PAHs are discussed. The determination of benz[a]pyrene in tap water is presented as an example. (orig.)

  13. Intrinsic biodegradation potential of aromatic hydrocarbons in an alluvial aquifer--potentials and limits of signature metabolite analysis and two stable isotope-based techniques.

    Science.gov (United States)

    Morasch, Barbara; Hunkeler, Daniel; Zopfi, Jakob; Temime, Brice; Höhener, Patrick

    2011-10-01

    Three independent techniques were used to assess the biodegradation of monoaromatic hydrocarbons and low-molecular weight polyaromatic hydrocarbons in the alluvial aquifer at the site of a former cokery (Flémalle, Belgium). Firstly, a stable carbon isotope-based field method allowed quantifying biodegradation of monoaromatic compounds in situ and confirmed the degradation of naphthalene. No evidence could be deduced from stable isotope shifts for the intrinsic biodegradation of larger molecules such as methylnaphthalenes or acenaphthene. Secondly, using signature metabolite analysis, various intermediates of the anaerobic degradation of (poly-) aromatic and heterocyclic compounds were identified. The discovery of a novel metabolite of acenaphthene in groundwater samples permitted deeper insights into the anaerobic biodegradation of almost persistent environmental contaminants. A third method, microcosm incubations with 13C-labeled compounds under in situ-like conditions, complemented techniques one and two by providing quantitative information on contaminant biodegradation independent of molecule size and sorption properties. Thanks to stable isotope labels, the sensitivity of this method was much higher compared to classical microcosm studies. The 13C-microcosm approach allowed the determination of first-order rate constants for 13C-labeled benzene, naphthalene, or acenaphthene even in cases when degradation activities were only small. The plausibility of the third method was checked by comparing 13C-microcosm-derived rates to field-derived rates of the first approach. Further advantage of the use of 13C-labels in microcosms is that novel metabolites can be linked more easily to specific mother compounds even in complex systems. This was achieved using alluvial sediments where 13C-acenaphthyl methylsuccinate was identified as transformation product of the anaerobic degradation of acenaphthene.

  14. Growth of fungi on volatile aromatic hydrocarbons

    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 environme

  15. Correlation between atmospheric polycyclic aromatic hydrocarbons exposure and urinary hydroxyl metabolites of polycyclic aromatic hydrocarbons in elderly population in Tianjin

    Institute of Scientific and Technical Information of China (English)

    秦晓蕾

    2013-01-01

    Objective To identify suitable hydroxyl polycyclic aromatic hydrocarbons(OH-PAHs) for co-evaluation of internal exposure level of PAHs by simultaneous determination of a variety of OH-PAHs in urine. Methods The 24-h individual particulate matter and morning urine

  16. Bacterial Community Dynamics and Polycyclic Aromatic Hydrocarbon Degradation during Bioremediation of Heavily Creosote-Contaminated Soil

    OpenAIRE

    Viñas, Marc; Sabaté, Jordi; Espuny, María José; Solanas, Anna M.

    2005-01-01

    Bacterial community dynamics and biodegradation processes were examined in a highly creosote-contaminated soil undergoing a range of laboratory-based bioremediation treatments. The dynamics of the eubacterial community, the number of heterotrophs and polycyclic aromatic hydrocarbon (PAH) degraders, and the total petroleum hydrocarbon (TPH) and PAH concentrations were monitored during the bioremediation process. TPH and PAHs were significantly degraded in all treatments (72 to 79% and 83 to 87...

  17. Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Wang, Xianli; Kang, Haiyan; Wu, Junfeng

    2016-05-01

    Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water.

  18. Health risk assessment of polycyclic aromatic hydrocarbons in the source water and drinking water of China: Quantitative analysis based on published monitoring data.

    Science.gov (United States)

    Wu, Bing; Zhang, Yan; Zhang, Xu-Xiang; Cheng, Shu-Pei

    2011-12-01

    A carcinogenic risk assessment of polycyclic aromatic hydrocarbons (PAHs) in source water and drinking water of China was conducted using probabilistic techniques from a national perspective. The published monitoring data of PAHs were gathered and converted into BaP equivalent (BaP(eq)) concentrations. Based on the transformed data, comprehensive risk assessment was performed by considering different age groups and exposure pathways. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties of risk estimation. The risk analysis indicated that, the risk values for children and teens were lower than the accepted value (1.00E-05), indicating no significant carcinogenic risk. The probability of risk values above 1.00E-05 was 5.8% and 6.7% for adults and lifetime groups, respectively. Overall, carcinogenic risks of PAHs in source water and drinking water of China were mostly accepted. However, specific regions, such as Yellow river of Lanzhou reach and Qiantang river should be paid more attention. Notwithstanding the uncertainties inherent in the risk assessment, this study is the first attempt to provide information on carcinogenic risk of PAHs in source water and drinking water of China, and might be useful for potential strategies of carcinogenic risk management and reduction.

  19. Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment

    Science.gov (United States)

    Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

    1998-01-01

    The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

  20. Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel.

    Science.gov (United States)

    Bernabei, M; Reda, R; Galiero, R; Bocchinfuso, G

    2003-01-24

    The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described.

  1. Determination of low concentrations of aromatic hydrocarbons in multicomponent mixtures with iso-octane and n-heptane

    Science.gov (United States)

    Vesnin, V. L.; Muradov, V. G.

    2011-11-01

    We have experimentally studied the absorption spectra of hydrocarbon mixtures based on n-heptane and isooctane with small (1%-2%) additions of aromatic hydrocarbons (benzene, toluene, xylene). The study was conducted in the region of the first overtones of the vibrational spectra for the hydrocarbon groups CH3, CH2, CH. We show that four-component modeling of the absorption spectrum of the hydrocarbon mixture and minimization of the deviation of the model spectrum from the experimental spectrum allow us to separately determine the content of the aromatic additives for concentrations from 1%.

  2. Determination of polycyclic aromatic hydrocarbons in biochar and biochar amended soil

    Science.gov (United States)

    A method for the determination of the 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in biochar and soil amended with biochar was developed. Samples were Soxhlet extracted with acetone:cyclohexane 1:1, and PAHs were analysed by GC-MS after silica gel clean-up. In a comparative study based on reflu...

  3. Occurrence and sources of particulate nitro-polycyclic aromatic hydrocarbons in ambient air in Denmark

    DEFF Research Database (Denmark)

    Feilberg, A.; Poulsen, M.W.B.; Nielsen, T.

    2001-01-01

    The occurrence of selected nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) associated with atmospheric particulate matter has been investigated at an urban site and at a semi-rural site. For this purpose an analysis method based on gas chromatography and tandem ion trap mass spectrometry has...

  4. Biodegradation Mechanism and Technology of Polycyclic Aromatic Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    DIAO Shuo; WANG Hong-qi; ZHENG Yi-nan; HUA Fei

    2016-01-01

    [Abstract]Polycyclic aromatic hydrocarbons are a class of potentially hazardous chemicals of environmental and health concern.PAHs are one of the most prevalent groups of contaminants found in soil.Biodegradation of complex hydrocarbon usually requires the cooperation of more than single specie.This paper reviews the existing screening methods of PAH-degrading bacteria.It studied the mechanism and technical applications of the co-metabolism in PAHs.Author gives the suggestions and prospects in Biodegradable trend of PHAs.

  5. Nanostructured alkyl carboxylic acid-based restricted access solvents: Application to the combined microextraction and cleanup of polycyclic aromatic hydrocarbons in mosses.

    Science.gov (United States)

    Caballero-Casero, N; Çabuk, H; Martínez-Sagarra, G; Devesa, J A; Rubio, S

    2015-08-26

    Alkyl carboxylic acid-based nanostructured solvents, synthesized in mixtures of tetrahydrofuran (THF) and water through self-assembly and coacervation, were proved to behave as restricted access liquids. Both physical and chemical mechanisms were found responsible for exclusion of macromolecules such as proteins and polysaccharides. The potential of these solvents for extracting small molecules from complex solid samples, without interference from large biomolecules, was here evaluated. For this purpose, they were applied to the extraction of 14 priority polycyclic aromatic hydrocarbons (PAHs) from mosses prior to their separation by liquid chromatography and fluorescence detection (LC-FLD). Sample treatment involved the vortex shaking of 200 mg of moss with 200 μL of decanoic acid-based solvent for 5 min, subsequent centrifugation for 8 min and analysis of the extract by LC-FLD using external calibration. Proteins precipitated during extraction because of both the decrease of the dielectric constant of the solution caused by THF and the formation of macromolecular complexes with decanoic acid. Polysaccharides were not solubilized in the aqueous cavities of the solvent because of their size exclusion. In-house method validation was performed according to the recommendations of the European Commission Decision 202/657/EC. Method detection and quantification limits for the different PAHs were in the ranges 0.04-0.24 and 0.14-0.80 μg kg(-1), respectively. The method was applied to the determination of different moss species collected in both polluted and unpolluted sites in the South of Spain. Recoveries were within the range 71-110%. The results obtained show that solvents with restricted access properties have the potential to expand the scope of application of restricted access materials to areas other than biological fluids because of their suitability to combine analyte isolation and sample cleanup of solid samples in a single step.

  6. Development of a sample preparation procedure of sewage sludge samples for the determination of polycyclic aromatic hydrocarbons based on selective pressurized liquid extraction.

    Science.gov (United States)

    Pena, Maria Teresa; Casais, Maria Carmen; Mejuto, Maria Carmen; Cela, Rafael

    2010-01-22

    An automated, simple and sensitive method based on selective pressurized liquid extraction (SPLE) was developed for the analysis of polycyclic aromatic hydrocarbons in sewage sludge samples. The new sample preparation procedure consists of on-line clean-up by inclusion of sorbents in the extraction cell, and combines elevated temperatures and pressures with liquid solvents to achieve fast and efficient removal of target analytes from complex sewage sludge matrices. The effects of various operational parameters (e.g. sample pretreatment, extraction solvent, temperature, pressure, static time, etc.) on the performance of SPLE procedure were carefully investigated, obtaining the best results when SPLE conditions were fixed at 140 degrees C, 1500 psi, static time of 5 min and n-hexane as extraction solvent. A new programmed temperature vaporization-gas chromatography-tandem mass spectrometry method based on large volume injection (PTV-LVI-GC-MS/MS) was also developed and analytical determinations were performed by high performance liquid chromatography coupled with fluorescence detection and GC-MS/MS. The extraction yields for the different compounds obtained by SPLE ranged from 84.8% to 106.6%. Quantification limits obtained for all of these studied compounds (between 0.0001 and 0.005 microg g(-1), dry mass) were well below the regulatory limits for all compounds considered. To test the accuracy of the SPLE technique, the optimized methodology was applied to the analysis of a certified reference material (sewage sludge (BCR088)) and a reference material (sewage sludge (RTC-CNS312-04)), with excellent results.

  7. Use of Physiologically-Based Pharmacokinetic Modeling to Simulate the Profiles of 3-Hydroxybenzo(a)pyrene in Workers Exposed to Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Heredia Ortiz, Roberto; Maître, Anne; Barbeau, Damien; Lafontaine, Michel; Bouchard, Michèle

    2014-01-01

    Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models were constructed from in vivo experimental data in rats and then extrapolated from animals to humans after assessing and adjusting the most sensitive model parameters as well as species specific physiological parameters. Repeated urinary voids from workers exposed to polycyclic aromatic hydrocarbons (PAHs) have been collected over the course of a typical workweek and during subsequent days off work; urinary concentrations of 3-OHBaP were then determined. Based on the information obtained for each worker (BaP air concentration, daily shift hours, tasks, protective equipment), the time courses of 3-OHBaP in the urine of the different workers have been simulated using the PBPK and toxicokinetic models, considering the various possible exposure routes, oral, dermal and inhalation. Both models were equally able to closely reproduce the observed time course of 3-OHBaP in the urine of workers and predicted similar exposure scenarios. Simulations of various scenarios suggest that the workers under study were exposed mainly by the dermal route. Comparison of measured air concentration levels of BaP with simulated values needed to obtain a good approximation of observed time course further pointed out that inhalation was not the main route of exposure for most of the studied workers. Both kinetic models appear as a useful tool to interpret biomonitoring data of PAH exposure on the basis of 3-OHBaP levels. PMID:25032692

  8. THE INFRARED SPECTROSCOPY OF NEUTRAL POLYCYCLIC AROMATIC HYDROCARBON CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Ricca, Alessandra [Carl Sagan Center, SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Bauschlicher, Charles W. Jr. [Entry Systems and Technology Division, Mail Stop 230-3, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Allamandola, Louis J., E-mail: Alessandra.Ricca-1@nasa.gov, E-mail: Charles.W.Bauschlicher@nasa.gov [Space Science Division, Mail Stop 245-6, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2013-10-10

    The mid-infrared spectra of neutral homogeneous polycyclic aromatic hydrocarbon (PAH) clusters have been computed using density functional theory including an empirical correction for dispersion. The C-H out-of-plane bending modes are redshifted for all the clusters considered in this work. The magnitude of the redshift and the peak broadening are dependent on PAH size, shape, and on the PAH arrangement in the cluster.

  9. Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability

    OpenAIRE

    Whitehead, Todd P; Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.

    2013-01-01

    Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 thr...

  10. Estimating individual-level exposure to airborne polycyclic aromatic hydrocarbons throughout the gestational period based on personal, indoor, and outdoor monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Choi, H.; Perera, F.; Pac, A.; Wang, L.; Flak, E.; Mroz, E.; Jacek, R.; Chai-Onn, T.; Jedrychowski, W.; Masters, E.; Camann, D.; Spengler, J. [Columbia University, New York, NY (United States)

    2008-11-15

    Current understanding on health effects of long-term polycyclic aromatic hydrocarbon (PAH) exposure is limited by lack of data on time-varying nature of the pollutants at an individual level. In a cohort of pregnant women in Krakow, Poland, we examined the contribution of temporal, spatial, and behavioral factors to prenatal exposure to airborne PAHs within each trimester and developed a predictive model of PAH exposure over the entire gestational period. The observed personal, indoor, and outdoor B(a)P levels we observed in Krakow far exceed the recommended Swedish guideline value for B(a)P of 0.1 ng/m{sup 3}. Based on simultaneously monitored levels, the outdoor PAH level alone accounts for 93% of total variability in personal exposure during the heating season. Living near the Krakow bus depot, a crossroad, and the city, center and time spent outdoors or commuting were not associated with higher personal exposure. During the nonheating season only, a 1-hr increase in environmental tobacco smoke (ETS) exposure was associated with a 10-16% increase in personal exposure to the nine measured PAHs. A 1{degree}C decrease in ambient temperature was associated with a 3-5% increase in exposure to benz(a)anthracene, benzo(k)fluoranthene, and dibenz(a,h)anthracene, after accounting for the outdoor concentration. A random effects model demonstrated that mean personal exposure at a given gestational period depends on the season, residence location, and ETS. Considering that most women reported spending < 3 hr/day outdoors, most women in the study were exposed to outdoor-originating PAHs within the indoor setting. Cross-sectional, longitudinal monitoring supplemented with questionnaire data allowed development of a gestation-length model of individual-level exposure with high precision and validity.

  11. π-Extended Star-Shaped Polycyclic Aromatic Hydrocarbons based on Fused Truxenes: Synthesis, Self-Assembly, and Facilely Tunable Emission Properties.

    Science.gov (United States)

    Cheng, Cheng; Jiang, Yi; Liu, Cheng-Fang; Zhang, Jian-Dong; Lai, Wen-Yong; Huang, Wei

    2016-12-19

    A new set of star-shaped polycyclic aromatic hydrocarbons (PAHs) based on naphthalene-fused truxenes, TrNaCn (n=1-4), were synthesized and characterized. The synthesis involved a microwave-assisted six-fold Suzuki coupling reaction, followed by oxidative cyclodehydrogenation. Multiple dehydrocyclization products could be effectively isolated in a single reaction, thus suggesting that the oxidative cyclodehydrogenation reaction involved a stepwise ring-closing process. The thermal, optical, and electrochemical properties and the self-assembly behavior of the resulting oxidized samples were investigated to understand the impact of the ring-fusing process on the properties of the star-shaped PAHs. Distinct bathochromic shift of the absorption maxima (λmax ) revealed that the molecular conjugation extended with the stepwise ring-closing reactions. The optical band-gap energy of these PAHs varied significantly on increasing the number of fused rings, thereby resulting in readily tunable emissive properties of the resultant star-shaped PAHs. Interestingly, the generation of rigid "arms" by using perylene analogues caused TrNaC2 and TrNaC3 to show significantly enhanced photoluminescence quantum yields (PLQYs) in solution (η=0.65 and 0.66, respectively) in comparison with those of TrNa and TrNaC1 (η=0.08 and 0.16, respectively). Owing to strong intermolecular interactions, the TrNa precursor was able to self-assemble into rod-like microcrystals, which could be facilely identified by the naked eye, whilst TrNaC1 self-assembled into nanosheets once the naphthalene rings had fused. This study offers a unique platform to gain further insight into-and a better understanding of-the photophysical and self-assembly properties of π-extended star-shaped PAHs.

  12. C-Nucleosides Derived from Simple Aromatic Hydrocarbons.

    Science.gov (United States)

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

    1997-04-01

    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.

  13. Methanogenic biodegradation of two-ringed polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Berdugo-Clavijo, Carolina; Dong, Xiaoli; Soh, Jung; Sensen, Christoph W; Gieg, Lisa M

    2012-07-01

    Polycyclic aromatic hydrocarbons (PAH) are widespread in methane-rich subsurface environments, such as oil reservoirs and fuel-contaminated aquifers; however, little is known about the biodegradation of these compounds under methanogenic conditions. To assess the metabolism of PAH in the absence of electron acceptors, a crude oil-degrading methanogenic enrichment culture was tested for the ability to biodegrade naphthalene, 1-methylnaphthalene (1-MN), 2-methylnaphthalene (2-MN), and 2, 6-dimethylnaphthalene (2, 6-diMN). When methane was measured as an indicator of metabolism, nearly 400 μmol of methane was produced in the 2-MN- and 2, 6-diMN-amended cultures relative to substrate-unamended controls, which is close to the amount of methane stoichiometrically predicted based on the amount of substrate added (51-56 μmol). In contrast, no substantial methane was produced in the naphthalene- and 1-MN-amended enrichments. In time course experiments, metabolite analysis of enrichments containing 2-MN and 2, 6-diMN revealed the formation of 2-naphthoic acid and 6-methyl-2-naphthoic acid, respectively. Microbial community analysis by 454 pyrosequencing revealed that these PAH-utilizing enrichments were dominated by archaeal members most closely affiliated with Methanosaeta and Methanoculleus species and bacterial members most closely related to the Clostridiaceae, suggesting that these organisms play an important role in the methanogenic metabolism of the substituted naphthalenes in these cultures.

  14. Thermodiffusion of polycyclic aromatic hydrocarbons in binary mixtures

    Science.gov (United States)

    Hashmi, Sara M.; Senthilnathan, Sid; Firoozabadi, Abbas

    2016-11-01

    Thermodiffusion in liquid mixtures may explain some counter-intuitive but naturally occurring phenomena such as hydrocarbon reservoirs with heavier component(s) stratified on top of lighter ones. However, beyond benchmark systems, systematic measurements of thermodiffusion in binary organic mixtures are lacking. We use an optical beam deflection apparatus to simultaneously probe Fickian and thermal diffusion in binary solution mixtures of polycyclic aromatic hydrocarbons dissolved in alkanes, and measure both Fickian diffusion D and the Soret coefficient ST, and then obtain the thermodiffusion coefficient DT. In a series of nine binary mixtures, we vary both the size of the aromatic compound from two to four rings, as well as the length of the alkane chain from 6 to 16 carbons. To probe the effect of increasing ring size, we include a 6-ringed aromatic compound, coronene, and toluene as a solvent, due to the insolubility of coronene in alkanes. Our results suggest that Fickian diffusion increases with the inverse of solvent viscosity and also with decreasing molecular weight of the solute. While both of these trends match our intuition, the behavior of ST and DT is more complicated. We find that ST and DT increase with the solute molecular weight when the solvent is held fixed and that the impact of solute ring size is higher in shorter chain alkane solvents.

  15. Atmospheric chlorinated polycyclic aromatic hydrocarbons in East Asia.

    Science.gov (United States)

    Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Hayakawa, Kazuichi; Toriba, Akira

    2014-09-01

    This study estimates atmospheric concentrations of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and polycyclic aromatic hydrocarbons (PAHs) in East Asia using a Gas Chromatograph with High Resolution Mass Spectrometer (GC-HRMS). ClPAHs are ubiquitously generated from PAHs through substitution, and some ClPAHs show higher aryl hydrocarbon receptor (AhR)-mediated activities than their parent PAHs. Atmospheric particles were collected using a high-volume air sampler equipped with a quartz-fiber filter. We determined the ClPAH concentrations of atmospheric particles collected in Japan (Sapporo, Sagamihara, Kanazawa, and Kitakyushu), Korea (Busan), and China (Beijing). The concentrations of ClPAHs were highest in the winter Beijing sample, where the total mean concentration was approximately 15-70 times higher than in the winter samples from Japan and Korea. The concentrations of Σ19ClPAHs and Σ9PAHs were significantly correlated in the Kanazawa and the Busan samples. This indicates that within those cities ClPAHs and PAHs share the same origin, implying direct chlorination of parent PAHs. Toxic equivalent concentrations (TEQs) of the total ClPAHs and PAHs were lowest in Kanazawa in the summer, reaching 1.18 and 2610fg-TEQm(-3) respectively, and highest in Beijing in the winter, reaching 627 and 4240000fg-TEQm(-3) respectively.

  16. The formation of polycyclic aromatic hydrocarbons in evolved circumstellar environments

    CERN Document Server

    Cherchneff, Isabelle

    2010-01-01

    The formation of Polycyclic Aromatic Hydrocarbons in the circumstellar outflows of evolved stars is reviewed, with an emphasis on carbon stars on the Asymptotic Giant Branch. Evidence for PAHs present in their winds is provided by meteoritic studies and recent observations of the Unidentified Infrared bands. We detail the chemical processes leading to the closure of the first aromatic ring as well as the growth mechanisms leading to amorphous carbon grains. Existing studies on PAH formation in evolved stellar envelopes are reviewed and new results for the modelling of the inner wind of the archetype carbon star IRC+10216 are presented. Benzene, C6H6, forms close to the star, as well as water, H2O, as a result of non-equilibrium chemistry induced by the periodic passage of shocks. The growth process of aromatic rings may thus resemble that active in sooting flames due to the presence of radicals like hydroxyl, OH. Finally, we discuss possible formation processes for PAHs and aromatic compounds in the hydrogen-...

  17. 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.

  18. Technogenic pollution of pine forests by polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    O. V. Kalugina

    2015-08-01

    Full Text Available Anthropogenic pollution of boreal forests by polycyclic aromatic hydrocarbons was assessed by polycyclic aromatic hydrocarbon (PAH concentrations in needles of Scots pine (Pinus sylvestris L. trees growing in the vicinity of the Bratsk aluminium smelter – one of the largest aluminium smelters in the world. The fieldwork was performed in 2012–2013 on 34 index plots, set in mixed herb and sedge-mixed herb pine forests (mostly site class III. It is shown that the total accumulation of PAHs reaches its highest level (more than 6000 ng/g in pine needle samples collected at sites up to 3 km from the aluminium smelter. PAH total quantity decreases with increasing the distance from the pollution source and at a distance of 50 km reaches values close to background ones. The highest concentrations of PAHs were detected in needle samples collected at plots located from the plant in a direction corresponding to the prevailing emissions transfer. There was also detected a significant difference in compositions of individual PAHs: there were 18 compounds identified in samples collected near the aluminium smelter whereas only 6 compounds were identified in samples collected on the background territories. Among the PAHs accumulated in pine trees assimilation organs the substances with 3–4 aromatic rings (phenanthrene, fluoranthene, pyrene, chrysene were dominant with their total number reaching 90 % of the total. Compound with 5–6 aromatic rings (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[e]pyrene, perylene, indeno[1,2,3-c,d]pyrene, benzo[g, h, i]perylene, dibenz[a, h]anthracene.comprises a smaller proportion (from 6 to 27 % in total PAHs content. High concentrations of benzo[a]pyrene and perylene in needle samples collected in the vicinity of the aluminum smelter indicate technogenic character of forest pollution.

  19. 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.

  20. Failure of hydrogenation in protecting polycyclic aromatic hydrocarbons from fragmentation

    CERN Document Server

    Gatchell, Michael; de Ruette, Nathalie; Chen, Tao; Giacomozzi, Linda; Nascimento, Rodrigo F; Wolf, Michael; Anderson, Emma K; Delaunay, Rudy; Viziano, Violaine; Rousseau, Patrick; Adoui, Lamri; Huber, Bernd A; Schmidt, Henning T; Zettergren, Henning; Cederquist, Henrik

    2015-01-01

    A recent study of soft X-ray absorption in native and hydrogenated coronene cations, C$_{24}$H$_{12+m}^+$ $m=0-7$, led to the conclusion that additional hydrogen atoms protect (interstellar) Polycyclic Aromatic Hydrocarbon (PAH) molecules from fragmentation [Reitsma et al., Phys. Rev. Lett. 113, 053002 (2014)]. The present experiment with collisions between fast (30-200 eV) He atoms and pyrene (C$_{16}$H$_{10+m}^+$, $m=0$, 6, and 16) and simulations without reference to the excitation method suggests the opposite. We find that the absolute carbon-backbone fragmentation cross section does not decrease but increases with the degree of hydrogenation for pyrene molecules.

  1. 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.

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

    Science.gov (United States)

    Tarnow, Patrick; Hutzler, Christoph; Grabiger, Stefan; Schön, Karsten; Tralau, Tewes; Luch, Andreas

    2016-01-01

    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.

  3. 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 C(6)-C(10) 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.

  4. Sorption of polycyclic aromatic hydrocarbons (PAHs) on glass surfaces.

    Science.gov (United States)

    Qian, Yuan; Posch, Tjorben; Schmidt, Torsten C

    2011-02-01

    Sorption of polycyclic aromatic hydrocarbons (PAHs) to glass commonly used in laboratories was studied. Sorption coefficients (Kd) of five selected PAHs to borosilicate glass surfaces were measured using column chromatography. A linear relationship between log Kd and the corresponding water solubility of the subcooled liquid (log Sw) of the investigated PAHs was observed. Based on the determined sorption coefficients our data revealed that mass loss caused by sorption on glass walls strongly depends on the ratio of solution volume to contacted surface area (V/S). The influence of solution chemistry such as ionic strength, solution pH, presence of cosolvent, and the influence of temperature on the sorption process were investigated. In the presence of ionic strength, sorption coefficients concurrently increased but less than a factor of 2 up to 0.005 M calcium chloride concentration. However, further increasing ionic strength had no influence on Kd. The cosolvent reduced sorption at a concentration of methanol in water above 0.5% (v/v); however, for benzo[a]pyrene even with 10% (v/v) methanol the mass loss would be still higher than 10% (with a V/S ratio less than 0.25). Significant effects of the solution pH and temperature were not observed. These results suggest that van der Waal's forces dominate the sorption process. In the analysis of highly hydrophobic PAHs in aqueous samples, mass loss due to sorption on glass walls should be accounted for in the final result if untreated glass is used. The presented relationship between log Kd and log Sw may help to decide if such a correction is necessary. Furthermore, the frequently used silanization of glass surfaces may not be sufficient to suppress sorption for large PAHs.

  5. Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues.

    Science.gov (United States)

    Breedveld, Gijs D; Pelletier, Emilien; St Louis, Richard; Cornelissen, Gerard

    2007-04-01

    High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinitesink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (-100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples.

  6. Polycyclic aromatic hydrocarbons and heavy metals in Kostrena coastal area.

    Science.gov (United States)

    Linsak, Dijana Tomić; Linsak, Zeljko; Besić, Denis; Vojcić, Nina; Telezar, Mirna; Coklo, Miran; Susnić, Sasa; Mićović, Vladimir

    2011-12-01

    The aim of this study was to determine pollution by polycyclic aromatic hydrocarbons (PAH) and heavy metals in seawater and sediment in Kostrena coastal area, as well as their toxicity using bioluminescence based tests. Total PAH concentration in seawater ranged 1.7-155.3 ng/L. The share of carcinogenetic PAH was relatively high, ranging 22-48.3%. Nickel concentrations in seawater were beyond detection limits (chrome concentrations were beyond detection limits, and copper concentrations were also beyond detection limits or extremely low (up to 0.32 microg/L). EC50 values in seawater ranged 23.80-90.90 ng/L. Correlation between total PAH concentration and toxicity of seawater showed strong connection between them (r = 0.9579). Total PAH concentration in marine sediment ranged 58.02-1116 microg/kg dry weight (d.w.). The share of carcinogenetic PAH was extremely high ranging 10-53%. Nickel concentrations in marine sediment ranged 8-24 mg/kg d.w., vanadium concentrations ranged 24-42 mg/kg d.w., chrome concentrations ranged 11-19 mg/kg d.w., and copper concentrations ranged 7-25 mg/kg d.w. EC50 values in marine sediment ranged 818-4596 microg/kg d.w. Correlation between total PAH concentration and toxicity of marine sediment showed weak connection between them (r = 0.2590). Previous studies of seawater samples from areas of the Adriatic sea under the direct influence of oil industry did not include concentrations of heavy metals, which makes our study the first to present such comprehensive results. Our results point out the need for further evaluations and following of marine environment pollution and its consequences on living organisms and marine ecosystem in whole.

  7. 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.

  8. Thermal neutron cross-section libraries for aromatic hydrocarbons

    Science.gov (United States)

    Cantargi, F.; Granada, J. R.

    2010-08-01

    Solid phases of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture by volume of mesitylene and toluene, were studied as potential moderator materials for a cold neutron source. Existing information on the (lattice) translational and rotational modes of the different molecular species was used to produce generalized frequency spectra; the latter included the internal vibrational modes which in turn involved the analysis of the weights of the different modes. Cross-section libraries were generated in ENDF and ACE formats for hydrogen bounded in those materials at several temperatures, and were used in Monte Carlo calculations to analyze their neutron production compared with standard cryogenic materials like liquid hydrogen and solid methane, the best moderators in terms of cold neutron production. In particular, cross-section libraries were generated at 20 K, which is a typical operating temperature for the majority of the existing cold neutron sources. It was found that those aromatic hydrocarbons produce neutron spectra which are slightly warmer than that of solid methane while presenting a high resistance to radiation, conforming in this way a new and advantageous alternative to traditional moderator materials.

  9. Direct photolysis of polycyclic aromatic hydrocarbons in drinking water sources

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, S. [Instituto de Biologia Experimental e Tecnologica (IBET), Av. Republica, Qta. do Marques (EAN), 2784-505 Oeiras (Portugal); Instituto de Tecnologia Quimica e Biologica (ITQB) - Universidade Nova de Lisboa (UNL), Av. da Republica, Estacao Agronomica Nacional, 2780-157 Oeiras (Portugal); Leitao, C. [Instituto de Tecnologia Quimica e Biologica (ITQB) - Universidade Nova de Lisboa (UNL), Av. da Republica, Estacao Agronomica Nacional, 2780-157 Oeiras (Portugal); Penetra, A.; Cardoso, V.V.; Ferreira, E.; Benoliel, M.J. [Empresa Portuguesa das Aguas Livres, S.A., Avenida de Berlim, 15, 1800-031 Lisboa (Portugal); Crespo, M.T. Barreto [Instituto de Biologia Experimental e Tecnologica (IBET), Av. Republica, Qta. do Marques (EAN), 2784-505 Oeiras (Portugal); Instituto de Tecnologia Quimica e Biologica (ITQB) - Universidade Nova de Lisboa (UNL), Av. da Republica, Estacao Agronomica Nacional, 2780-157 Oeiras (Portugal); Pereira, V.J., E-mail: vanessap@itqb.unl.pt [Instituto de Biologia Experimental e Tecnologica (IBET), Av. Republica, Qta. do Marques (EAN), 2784-505 Oeiras (Portugal); Instituto de Tecnologia Quimica e Biologica (ITQB) - Universidade Nova de Lisboa (UNL), Av. da Republica, Estacao Agronomica Nacional, 2780-157 Oeiras (Portugal)

    2011-09-15

    Highlights: {yields} Low pressure UV photolysis can be used by drinking water utilities to degrade PAHs. {yields} Real water matrices with different compositions were tested. {yields} Photolysis kinetic parameters and by-product formation are described. {yields} The formation of photolysis by-products is highly dependent on the source waters. - Abstract: The widely used low pressure lamps were tested in terms of their efficiency to degrade polycyclic aromatic hydrocarbons listed as priority pollutants by the European Water Framework Directive and the U.S. Environmental Protection Agency, in water matrices with very different compositions (laboratory grade water, groundwater, and surface water). Using a UV fluence of 1500 mJ/cm{sup 2}, anthracene and benzo(a)pyrene were efficiently degraded, with much higher percent removals obtained when present in groundwater (83-93%) compared to surface water (36-48%). The removal percentages obtained for fluoranthene were lower and ranged from 13 to 54% in the different water matrices tested. Several parameters that influence the direct photolysis of polycyclic aromatic hydrocarbons were determined and their photolysis by-products were identified by mass spectrometry. The formation of photolysis by-products was found to be highly dependent on the source waters tested.

  10. Emissions of Parent, Nitro, and Oxygenated Polycyclic Aromatic Hydrocarbons from Residential Wood Combustion in Rural China

    OpenAIRE

    SHEN, Guofeng; TAO, SHU; WEI, Siye; ZHANG, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; HUANG, YE; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wang, Xilong; Liu, Wenxin

    2012-01-01

    Residential wood combustion is one of the important sources of air pollution in developing countries. Among the pollutants emitted, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives, including nitrated and oxygenated PAHs (nPAHs and oPAHs), are of concern because of their mutagenic and carcinogenic effects. In order to evaluate their impacts on regional air quality and human health, emission inventories, based on realistic emission factors (EFs), are needed. In this study,...

  11. 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

  12. Partially oxidized polycyclic aromatic hydrocarbons show an increased bioavailability and biodegradability.

    NARCIS (Netherlands)

    Meulenberg, R.; Rijnaarts, H.H.M.; Doddema, H.J.; Field, J.A.

    1997-01-01

    Polycyclic aromatic hydrocarbons have a low water solubility and tend to adsorb on soil particles, which both result in slow bioremediation processes. Many microorganisms, known for their ability to degrade polycyclic aromatic hydrocarbons, only partially oxidize these compounds. White rot fungi, fo

  13. 75 FR 8937 - Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH...

    Science.gov (United States)

    2010-02-26

    ... AGENCY Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH...) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures'' (EPA/635/R-08/012A). The draft document was... 27, 2010. The listening session on the draft document for PAH mixtures will be held on April 7,...

  14. 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.

  15. Blockade of the aryl hydrocarbon receptor pathway triggered by dioxin, polycyclic aromatic hydrocarbons and cigarette smoke by Phellinus linteus.

    Science.gov (United States)

    Mukai, Mai; Kasai, Ayumi; Hiramatsu, Nobuhiko; Hayakawa, Kunihiro; Okamura, Maro; Tagawa, Yasuhiro; Yao, Jian; Nakamura, Tomoyuki; Kitamura, Masanori

    2008-10-01

    Environmental pollutants including halogenated and polycyclic aromatic hydrocarbons activate the aryl hydrocarbon receptor (AhR) and thereby cause a wide range of pathological changes. Development of AhR antagonists will be useful for prevention and treatment of diseases related to AhR activation. Towards this end, we aimed in the present study at seeking for potential inhibitors of the AhR pathway in mycelial extracts using the dioxin responsive element-based sensing via secreted alkaline phosphatase (DRESSA). Through the screening of 13 mycelia, extracts prepared from Phellinus linteus, Cordyceps militaris and Hericium erinaceum inhibited activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin, benzo[a]pyrene or 3-methylcholanthrene. Subsequent studies revealed that only Phellinus linteus suppressed activation of AhR and AhR-dependent gene expression triggered by all of these agonists. Cigarette smoke is known to contain a number of halogenated and polycyclic aromatic hydrocarbons. We found that Phellinus linteus has the potential to block activation of AhR and AhR-dependent gene expression triggered by cigarette smoke. Furthermore, the inhibitory effect of Phellinus linteus on the AhR pathway was independent of; 1) depression of AhR or AhR nuclear translocator, and 2) induction of AhR repressor. We conclude that Phellinus linteus contains potent inhibitor(s) of AhR activation and may be useful for prevention of pathologies associated with aberrant activation of AhR.

  16. An Emission Inventory of Polycyclic Aromatic Hydrocarbons in China

    Science.gov (United States)

    Mu, Xilong; Zhu, Xianlei; Wang, Xuesong

    2015-04-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are among the most dangerous compounds due to their high carcinogenic and mutagenic character. Emission inventory provides the primary data to account for the sources of ambient PAHs and server as a necessary database for effective PAHs pollution control. China is experiencing fast economic growth and large energy consumption, which might result in a large amount of PAHs anthropogenic emissions. Therefore, based on the previous studies and combined recently field emission measurements as well as socio-economic activity data, the development of a nationwide PAHs emission inventory is needed. In this work, the emission inventory of 16 PAHs listed as U.S. Environmental Protection Agency priority pollutants in China in the year 2012 is compiled. The emission amounts of PAHs were estimated as annual rates of emission-related activities multiplied by respective emission factors. The activities such as fuel consumption, including fossil fuel and biofuel, and socio-economic statistics were obtained from yearbook released by Chinese central government and/or provincial governments, as well as related industry reports. Emission factors were derived from the related literature. Recently reported emission factors from local measurements were used. The total emissions of PAHs were 120611 ton in 2012. In China, PAHs were emitted predominantly from domestic combustion of coal and biofuel, coking industry and motor vehicles, accounting for 72% of the total amount. PAHs emission profiles were significantly different between China and the other countries. The emission profile in China featured a relatively higher portion of high molecular weight species with carcinogenic potential due to large contributions of domestic combustion and coking industry. Domestic combustion of straw, coal and firewood emitted 19464 ton, 8831 ton, and 5062 ton of PAHs, respectively, which were much higher than those in other countries. Emission per capita showed

  17. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction

    Energy Technology Data Exchange (ETDEWEB)

    Pena, M.T.; Pensado, Luis; Casais, M.C.; Mejuto, M.C.; Cela, Rafael [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia. Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2007-04-15

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 {mu}g kg{sup -1} dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials. (orig.)

  18. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction.

    Science.gov (United States)

    Pena, M Teresa; Pensado, Luis; Casais, M Carmen; Mejuto, M Carmen; Cela, Rafael

    2007-04-01

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 microg kg(-1) dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials.

  19. Analysis of intervention strategies for inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk based on a Monte Carlo population exposure assessment model.

    Directory of Open Access Journals (Sweden)

    Bin Zhou

    Full Text Available It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs, a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF and potential impact fraction (PIF of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.

  20. In situ microbial metabolism of aromatic-hydrocarbon environmental pollutants.

    Science.gov (United States)

    Jeon, Che Ok; Madsen, Eugene L

    2013-06-01

    Microbial processes that eliminate organic environmental contamination are important. Progress in the biotechnology of biodegradation relies upon the underlying sciences of environmental microbiology and analytical geochemistry. Recent key discoveries advancing knowledge of biodegradation (in general) and the aromatic-hydrocarbon biodegradation (in particular) have relied upon characterization of microorganisms: pure-culture isolates, laboratory enrichment cultures, and in contaminated field sites. New analytical and molecular tools (ranging from sequencing the DNA of biodegrading microorganisms to assessing changes in the isotopic ratios of 13C to 12C and 2H to 1H in contaminant pools in field sites) have deepened our insights into the mechanisms (how), the occurrence (what), and the identity (who) of active players that effect biodegradation of organic environmental pollutants.

  1. Study of ionic equilibria of indotricarbocyanines in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Dyadyusha, G.G.; Ishchenko, A.A.; Derevyanko, N.A.; Tolmachev, A.I.

    1982-05-01

    Study of the equilibria in nonpolar solvents is very complicated by the poor solubility of the salt-like dyes. Indotricarbocyanines I and II were found to be fairly soluble in aromatic hydrocarbons for solving these problems by means of electronic spectra. In the present work, their absorption spectra were studied in benzene, toluene, and m-xylene (the absorption spectra were measured on the SF-8 spectrophotometer). It was shown that the dyes studied in these solvents have spectral bands of unusual form of polymethine dyes. At the long wave edge of the spectra of indotricarbocyanines, a distinct band appears, whose intensity is very dependent on the nature of the anion. In the case of perchlorate I, it has a lower intensity, and in the case of iodide II, the intensity is higher.

  2. 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.

  3. Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: a Survey

    Science.gov (United States)

    Salama, F.; Galazutdinov, G. A.; Krelowski, J.; Allamandola, L. J.; Musaev, F. A.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices, are compared with an extensive set of astronomical spectra of reddened, early type stars. From this comparison, it is concluded that PAN ions are good candidates to explain some of the DIBs. Unambiguous assignments are difficult, however, due to the shift in wavelengths and the band broadening induced in the laboratory spectra by the solid matrix. Definitive band assignments and, ultimately, the test of the of the proposal that PAH ions carry some of the DIB must await the availability of gas-phase measurements in the laboratory. The present assessment offers a guideline for future laboratory experiments by allowing the preselection of promising PAH molecules to be studied in jet expansions.

  4. 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.

  5. 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.)

  6. Polycyclic aromatic hydrocarbons in sediments of China Sea.

    Science.gov (United States)

    Li, Yanxia; Duan, Xiaoyong

    2015-10-01

    Increasing pollution pressures were placed in the coastal and estuarine ecosystems in China because of the elevated pollutants discharged from various sources. Polycyclic aromatic hydrocarbons (PAHs) in the environment were closely linked to human activities, which have been intensively studied for their geochemical interest as markers. In this review, the status of PAH contamination in China Sea was assessed by comprehensive reviews of the concentrations, sources, and fates of PAHs in sediments of China Sea. PAH concentrations in China Sea sediments decreased from north to south due to the higher emissions in North China. Atmosphere was probably the main carrier of PAHs in the north due to the higher contents of atmospheric fine particles and higher wind speeds. However, riverine inputs were probably the most important sources of PAHs in the coastal sediments of South China due to higher rainfall.

  7. The distribution of polycyclic aromatic hydrocarbons in asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Y. [Inst. Mexicano del Petroleo, Lazaro (Mexico). Programa de Ingenieria Molecular; Ballard Andrews, A.; Mullins, O.C. [Schlumberger-Doll Research Center, Cambridge, MA (United States)

    2008-07-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in asphaltenes is a strong determinant for asphaltene physical properties. PAHs also provide the UV and visible absorption and emission profiles of asphaltenes. All PAHs absorb light in the UV-visible spectrum and many also emit light in this spectral range. This study combined a molecular orbital theory with an experimental approach to quantitatively link the UV-visible absorption and emission profiles to the asphaltene PAH distribution. Key features of the absorption and emission spectral data were found to be reproduced with PAH distributions centered at 7 fused rings. The study also identified other highly different distributions of PAHs in terms of plausibility to account for the measured optical data. The paper also described the affect that heteroatoms had on the analysis.

  8. Removal of high-molecular weight polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Ulrich Vasconcelos

    2011-01-01

    Full Text Available Alternatives for the removal of high-molecular weight polycyclic aromatic hydrocarbons (HWM-PAH from soil were tested by adding fertilizer or glycerol, as well as the combination of both. Experiments were carried out for 60 days in reactors containing a HWM-PAH-contaminated soil (8030 μg kg-1, accompanied by pH monitoring, humidity control and quantification of total heterotrophic bacteria and total fungus. Fertilizer addition removed 41.6% of HWM-PAH. Fertilizer and glycerol in combination removed 46.2%. When glycerol was added individually, degradation reached 50.4%. Glycerol also promoted the increase of degradation rate during the first 30 days suggesting the HMW-PAH removal occurred through cometabolic pathways.

  9. Dehydrogenation of polycyclic aromatic hydrocarbons in the diffuse interstellar medium

    CERN Document Server

    Foing, B H

    2000-01-01

    We present a model for the hydrogenation states of Polycyclic Aromatic Hydrocarbons (PAHs) in the diffuse interstellar medium. First, we study the abundance of hydrogenation and charge states of PAHs due to photo-ionization, photo-dissociation in the interstellar UV field, electron recombination and chemical reactions between PAH cations and H or H_2. For PAH cations, we find that the dehydrogenation effects are dominant. The hydrogenation state of PAHs depends strongly on the H density, the size of the molecule and UV field. In diffuse clouds with low H density and normal UV radiation, PAHs containing less than 40 C are completely or strongly dehydrogenated whereas at high H density, they are normally hydrogenated. The partially dehydrogenated species dominate in intermediate density clouds. PAHs above 40 C are quite stable and are fully hydrogenated, which would favor their spectroscopic search in near IR surveys of Diffuse Interstellar Bands (DIBs).

  10. Polycyclic Aromatic Hydrocarbons in Electrocautery Smoke during Peritonectomy Procedures

    Directory of Open Access Journals (Sweden)

    Sara Näslund Andréasson

    2012-01-01

    Full Text Available Objective. This study identified and quantified polycyclic aromatic hydrocarbons (PAHs in electrocautery smoke during 40 peritonectomy procedures and investigated any correlations and/or differences between levels of PAHs and perioperative variables. Methods. PAHs were measured in personal and stationary sampling by 40 mm Millipore cassettes, for adsorption of both gaseous and particle-bound PAHs. Results. All 16 USEPA priority pollutant PAHs were detected during peritonectomy procedures, naphthalene being the most abundant. For the only two PAHs with Swedish occupational exposure limits (OELs, benzo[a]pyrene and naphthalene, limits were never exceeded. Amount of bleeding was the only perioperative variable that correlated with levels of PAHs. Conclusions. Low levels of PAHs were detected in electrocautery smoke during peritonectomy procedures, and an increased amount of bleeding correlated with higher levels of PAHs. For evaluation of long-term health effects, more studies are needed.

  11. Formation History of Polycyclic Aromatic Hydrocarbons in Galaxies

    CERN Document Server

    Seok, Ji Yeon; Asano, Ryosuke S

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are some of the major dust components in the interstellar medium (ISM). We present our evolution models for the abundance of PAHs in the ISM on a galaxy-evolution timescale. We consider shattering of carbonaceous dust grains in interstellar turbulence as the formation mechanism of PAHs while the PAH abundance can be reduced by coagulation onto dust grains, destruction by supernova shocks, and incorporation into stars. We implement these processes in a one-zone chemical evolution model to obtain the evolution of the PAH abundance in a galaxy. We find that PAH formation becomes accelerated above certain metallicity where shattering becomes efficient. For PAH destruction, while supernova shock is the primary mechanism in the metal-poor environment, coagulation is dominant in the metal-rich environment. We compare the evolution of the PAH abundances in our models with observed abundances in galaxies with a wide metallicity range. Our models reproduce both the paucity of PAH...

  12. 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.

  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. Oil and gas potential assessment for coal measure source rocks on absolute concentration of n-alkanes and aromatic hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Absolute concentration of normal alkanes(n-alkanes) and aromatic hydrocarbons in bitumen extracted from source rocks in the period of thermodegradation from Turpan-Hami Basin suggests that aromatic hydrocarbons are dominant in coal and carbargilite while n-alkanes are dominant in mudstones. Bulkrock analysis and gas chromatograph/mass spectrum(GC-MS) of source rocks shows aromatic hydrocarbons are dominant in total ion chromatograms(TIC) of samples with poor perhydrous macerals while n-alkanes are dominant in TICs of samples with abundant perhydrous macerals. The identification of oil-prone and gas prone property based on GC-MS of bitumen "A" together with bulkrock analysis indicates that source rocks from Shengbei area are more oil-prone while source rocks from Qiudong and Xiaocaohu areas are more gas-prone,coinciding with the distribution of oil and gas reservoirs in Taibei Sag. Ratios used to identify oil-prone and gas-prone property for source rocks from Turpan Basin are proposed:n-alkanes >110 μg·mg-1,aromatics <15 μg·mg-1,and n-alkanes/aromatics >8 for oil-prone source rock bitumen while n-alkanes<82 μg·mg-1,aromatics >40 μg·mg-1,and n-alkanes/aromatics <1.5 for gas-prone source rock bitumen.

  15. Biodegradation aspects of polycyclic aromatic hydrocarbons (PAHs): a review.

    Science.gov (United States)

    Haritash, A K; Kaushik, C P

    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(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

  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. Study on Aromatization of C6 Aliphatic Hydrocarbons on ZRP Zeolite Catalyst

    Institute of Scientific and Technical Information of China (English)

    Wang Yongjun; Xie Chaogang

    2004-01-01

    The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.

  18. 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.

  19. Thermochemical properties and phase behavior of halogenated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Fu, Jinxia; Suuberg, Eric M

    2012-03-01

    Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene, and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464 K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared with parent compounds but does not necessarily increase the enthalpy of sublimation. Furthermore, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared with single halogen-substituted polycyclic aromatic hydrocarbons. In addition, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis.

  20. Sorption of polycyclic aromatic hydrocarbons to polystyrene nanoplastic.

    Science.gov (United States)

    Liu, Lijing; Fokkink, Remco; Koelmans, Albert A

    2016-07-01

    Microplastic has become an emerging contaminant of global concern. Bulk plastic can degrade to form smaller particles down to the nanoscale (nanoplastics. Because of their high surface area, nanoplastic may bind hydrophobic chemicals very effectively, increasing their hazard when such nanoplastics are taken up by biota. The present study reports distribution coefficients for sorption of polycyclic aromatic hydrocarbons (PAHs) to 70 nm polystyrene in freshwater, and PAH adsorption isotherms spanning environmentally realistic aqueous concentrations of 10(-5)  μg/L to 1 μg/L. Nanopolystyrene aggregate state was assessed using dynamic light scattering. The adsorption isotherms were nonlinear, and the distribution coefficients at the lower ends of the isotherms were very high, with values up to 10(9) L/kg. The high and nonlinear sorption was explained from π-π interactions between the planar PAHs and the surface of the aromatic polymer polystyrene and was higher than for micrometer-sized polystyrene. Reduction of nanopolystyrene aggregate sizes had no significant effect on sorption, which suggests that the PAHs could reach the sorption sites on the pristine nanoparticles regardless of the aggregation state. Pre-extraction of the nanopolystyrene with C18 polydimethylsiloxane decreased sorption of PAHs, which could be explained by removal of the most hydrophobic fraction of the nanopolystyrene. Environ Toxicol Chem 2016;35:1650-1655. © 2015 SETAC.

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

    Institute of Scientific and Technical Information of China (English)

    Thamaraiselvan; Rengarajan; Peramaiyan; Rajendran; Natarajan; Nandakumar; Boopathy; Lokeshkumar; Palaniswami; Rajendran; Ikuo; Nishigaki

    2015-01-01

    Polycyclie 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.

  2. Evaluation of anthropogenic secondary organic aerosol tracers from aromatic hydrocarbons

    Science.gov (United States)

    Al-Naiema, Ibrahim M.; Stone, Elizabeth A.

    2017-02-01

    Products of secondary organic aerosol (SOA) from aromatic volatile organic compounds (VOCs) - 2,3-dihydroxy-4-oxopentanoic acid, dicarboxylic acids, nitromonoaromatics, and furandiones - were evaluated for their potential to serve as anthropogenic SOA tracers with respect to their (1) ambient concentrations and detectability in PM2.5 in Iowa City, IA, USA; (2) gas-particle partitioning behaviour; and (3) source specificity by way of correlations with primary and secondary source tracers and literature review. A widely used tracer for toluene-derived SOA, 2,3-dihydroxy-4-oxopentanoic acid was only detected in the particle phase (Fp = 1) at low but consistently measurable ambient concentrations (averaging 0.3 ng m-3). Four aromatic dicarboxylic acids were detected at relatively higher concentrations (9.1-34.5 ng m-3), of which phthalic acid was the most abundant. Phthalic acid had a low particle-phase fraction (Fp = 0.26) likely due to quantitation interferences from phthalic anhydride, while 4-methylphthalic acid was predominantly in the particle phase (Fp = 0.82). Phthalic acid and 4-methylphthalic acid were both highly correlated with 2,3-dihydroxy-4-oxopentanoic acid (rs = 0.73, p = 0.003; rs = 0.80, p hydrocarbons; however the substantial partitioning toward the gas phase (Fp ≤ 0.16) and their water sensitivity limit their application as tracers. The outcome of this study is the demonstration that 2,3-dihydroxy-4-oxopentanoic acid, phthalic acid, 4-methylphthalic acid, and 4-hydroxy-3-nitrobenzyl alcohol are good candidates for tracing SOA from aromatic VOCs.

  3. Inhibitory effects of polycyclic aromatic hydrocarbons (PAHs) on photosynthetic performance are not related to their aromaticity.

    Science.gov (United States)

    Jajoo, Anjana; Mekala, Nageswara Rao; Tomar, Rupal Singh; Grieco, Michele; Tikkanen, Mikko; Aro, Eva-Mari

    2014-08-01

    Polycyclic aromatic hydrocarbons (PAHs) are very toxic and highly persistent environmental pollutants which accumulate in soil and affect growth of the plants adversely. This study aims to investigate inhibitory effects of 3 major PAH particularly on photosynthetic processes in Arabidopsis thaliana grown in soil treated with PAH. The 3 PAH chosen differ from each other in aromaticity (number of rings) comprising their structure (2 rings: naphthalene, 3 rings: anthracene and 4 rings: pyrene). Several growth parameters and Chlorophyll a fluorescence was monitored in PAH treated plants. BN-PAGe analysis was done in order to get information about change in the protein conformation. PAH treatment led to increased value of Fo which collaborated with increase in the amount of free LHC as seen through BN-Page analysis. Thus PAH were found to inhibit PS II photochemistry and caused distinct change in pigment composition. However the results led us to infer that 3-ring anthracence is more inhibitory as compared to 2-ring naphthalene and 4-ring pyrene. This indicates that aromaticity of PAH is unrelated to their response on photosynthetic processes.

  4. ExBox: a polycyclic aromatic hydrocarbon scavenger.

    Science.gov (United States)

    Barnes, Jonathan C; Juríček, Michal; Strutt, Nathan L; Frasconi, Marco; Sampath, Srinivasan; Giesener, Marc A; McGrier, Psaras L; Bruns, Carson J; Stern, Charlotte L; Sarjeant, Amy A; Stoddart, J Fraser

    2013-01-09

    A template-directed protocol, which capitalizes on donor-acceptor interactions, is employed to synthesize a semi-rigid cyclophane (ExBox(4+)) that adopts a box-like geometry and is comprised of π-electron-poor 1,4-phenylene-bridged ("extended") bipyridinium units (ExBIPY(2+)). ExBox(4+) functions as a high-affinity scavenger of an array of different polycyclic aromatic hydrocarbons (PAHs), ranging from two to seven fused rings, as a result of its large, accommodating cavity (approximately 3.5 Å in width and 11.2 Å in length when considering the van der Waals radii) and its ability to form strong non-covalent bonding interactions with π-electron-rich PAHs in either organic or aqueous media. In all, 11 PAH guests were observed to form inclusion complexes with ExBox(4+), with coronene being the largest included guest. Single-crystal X-ray diffraction data for the 11 inclusion complexes ExBox(4+)⊂PAH as well as UV/vis spectroscopic data for 10 of the complexes provide evidence of the promiscuity of ExBox(4+) for the various PAHs. Nuclear magnetic resonance spectroscopy and isothermal titration calorimetric analyses of 10 of the inclusion complexes are employed to further characterize the host-guest interactions in solution and determine the degree with which ExBox(4+) binds each PAH compound. As a proof-of-concept, a batch of crude oil from Saudi Arabia was subjected to extraction with the water-soluble form of the PAH receptor, ExBox·4Cl, resulting in the isolation of different aromatic compounds after ExBox·4Cl was regenerated.

  5. 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

  6. Polycyclic aromatic hydrocarbons: from metabolism to lung cancer.

    Science.gov (United States)

    Moorthy, Bhagavatula; Chu, Chun; Carlin, Danielle J

    2015-05-01

    Excessive exposure to polycyclic aromatic hydrocarbons (PAHs) often results in lung cancer, a disease with the highest cancer mortality in the United States. After entry into the lung, PAHs induce phase I metabolic enzymes such as cytochrome P450 (CYP) monooxygenases, i.e. CYP1A1/2 and 1B1, and phase II enzymes such as glutathione S-transferases, UDP glucuronyl transferases, NADPH quinone oxidoreductases (NQOs), aldo-keto reductases (AKRs), and epoxide hydrolases (EHs), via the aryl hydrocarbon receptor (AhR)-dependent and independent pathways. Humans can also be exposed to PAHs through diet, via consumption of charcoal broiled foods. Metabolism of PAHs through the CYP1A1/1B1/EH pathway, CYP peroxidase pathway, and AKR pathway leads to the formation of the active carcinogens diol-epoxides, radical cations, and o-quinones. These reactive metabolites produce DNA adducts, resulting in DNA mutations, alteration of gene expression profiles, and tumorigenesis. Mutations in xenobiotic metabolic enzymes, as well as polymorphisms of tumor suppressor genes (e.g. p53) and/or genes involved in gene expression (e.g. X-ray repair cross-complementing proteins), are associated with lung cancer susceptibility in human populations from different ethnicities, gender, and age groups. Although various metabolic activation/inactivation pathways, AhR signaling, and genetic susceptibilities contribute to lung cancer, the precise points at which PAHs induce tumor initiation remain unknown. The goal of this review is to provide a current state-of-the-science of the mechanisms of human lung carcinogenesis mediated by PAHs, the experimental approaches used to study this complex class of compounds, and future directions for research of these compounds.

  7. Identification and discrimination of polycyclic aromatic hydrocarbons using Raman spectroscopy

    Science.gov (United States)

    Cloutis, Edward; Szymanski, Paul; Applin, Daniel; Goltz, Douglas

    2016-08-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely present throughout the Solar System and beyond. They have been implicated as a contributor to unidentified infrared emission bands in the interstellar medium, comprise a substantial portion of the insoluble organic matter in carbonaceous chondrites, are expected stable components of organic matter on Mars, and are present in a wide range of terrestrial hydrocarbons and as components of biomolecules. However, PAH structures can be very complicated, making their identification challenging. Raman spectroscopy is known to be especially sensitive to the highly polarizable C-C and C=C bonds found in PAHs, and therefore, can be a powerful tool for PAH structural and compositional elucidation. This study examined Raman spectra of 48 different PAHs to determine the degree to which Raman spectroscopy could be used to uniquely identify different species, factors that control the positions of major Raman peaks, the degree to which induced fluorescence affects the intensity of Raman peaks, its usefulness for PAH discrimination, and the effects of varying excitation wavelength on some PAH Raman spectra. It was found that the arrangement and composition of phenyl (benzene) rings, and the type and position of functional groups can greatly affect fluorescence, positions and intensities of Raman peaks associated with the PAH backbone, and the introduction of new Raman peaks. Among the functional groups found on many of the PAHs that were analyzed, only a few Raman peaks corresponding to the molecular vibrations of these groups could be clearly distinguished. Comparison of the PAH Raman spectra that were acquired with both 532 and 785 nm excitation found that the longer wavelength resulted in reduced fluorescence, consistent with previous studies.

  8. MULTISUBSTRATE BIODEGRADATION KINETICS FOR BINARY AND COMPLEX MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBONS

    Science.gov (United States)

    Biodegradation kinetics were studied for binary and complex mixtures of nine polycyclic aromatic hydrocarbons (PAHs): naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, phenanthrene, anthracene, pyrene, fluorene and fluoranthene. Discrepancies between the ...

  9. Identification of persulfate oxidation products of polycyclic aromatic hydrocarbon during remediation of contaminated soil

    Science.gov (United States)

    The extent of PAH transformation, the formation and transformation of reaction byproducts during persulfate oxidation of polycyclic aromatic hydrocarbons (PAHs) in coking plant soil was investigated. Pre-oxidation analyses indicated that oxygen-containing PAHs (oxy-PAHs) existed ...

  10. Do lagoon area sediments act as traps for polycyclic aromatic hydrocarbons?

    Science.gov (United States)

    Marini, Mauro; Frapiccini, Emanuela

    2014-09-01

    The coastal lagoons are vulnerable systems, located between the land and the sea, enriched by both marine and continental inputs and are among the most productive aquatic ecosystems. The purpose of this work is to understand the influence of the lagoon area sediments on the behaviour of polycyclic aromatic hydrocarbons, through the adsorption coefficient determination. In fact, the sorption of polycyclic aromatic hydrocarbons is an important process because it governs the fate, transport, bioavailability and toxicity of these compounds in sediments. It has been observed that the adsorption of polycyclic aromatic hydrocarbons in a transitional system is the outcome of different factors, such as their sources and physicochemical properties, salinity and sediment composition, hydrology and environmental conditions. The results showed that transitional areas contribute to the polycyclic aromatic hydrocarbon accumulation in the sediment turning it into a trap.

  11. STUDIES ON BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SEDIMENTS: BIOAVAILABILITY, BIODEGRADABILITY, AND TOXICITY ISSUES

    Science.gov (United States)

    The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes, on which the bioavailability and the toxicity of PAHs often have a significant impact. This research investigated the biode...

  12. Comparison of passive and standard dosing of polycyclic aromatic hydrocarbons to the marine algae Phaeodactylum tricornutum

    DEFF Research Database (Denmark)

    Witt, G.; Niehus, N. C.; Konopka, K.

    2015-01-01

    Testing hydrophobic organic compounds (HOCs), like polycyclic aromatic hydrocarbons (PAHs), in aquatic toxicity tests is difficult due to compound losses through volatilization, sorption to the test vessel and culture medium constituents. This results in poorly defined exposure, the bioavailable...

  13. Modeling the Role of Alkanes, Polycyclic Aromatic Hydrocarbons, and Their Oligomers in Secondary Organic Aerosol Formation

    Science.gov (United States)

    A computationally efficient method to treat secondary organic aerosol (SOA) from various length and structure alkanes as well as SOA from polycyclic aromatic hydrocarbons (PAHs) is implemented in the Community Multiscale Air Quality (CMAQ) model to predict aerosol concentrations ...

  14. Dynamics of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Cochin estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ramzi, A; Rahman, K.H.; Gireeshkumar, T.R.; Balachandran, K.K.; Jacob, C.; Chandramohanakumar, N

    Polycyclic aromatic hydrocarbons (PAHs) showed significant seasonal dynamics in surface sediments of a tropical ecosystem (Cochin estuary, south west coast of India). Concentrations ranged from 304 to 5874 ngg-1 in pre-monsoon, 493 to 14...

  15. Recent analytical methods for atmospheric polycyclic aromatic hydrocarbons and their derivatives.

    Science.gov (United States)

    Hayakawa, Kazuichi; Tang, Ning; Toriba, Akira

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are ubiquitous environmental pollutants. Moreover, some oxidative metabolites of these pollutants, such as hydroxylated and epoxide PAHs, cause endocrine disruption or produce reactive oxygen species. These compounds have become a large concern from the viewpoint of particulate matter (PM2.5 ) pollution. This report deals with recent studies concerning analytical methods for PAHs, NPAHs and related compounds in atmospheric and biological samples.

  16. Solubilization and biodegradation of polycyclic aromatic hydrocarbons in microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Wong, J.W.C.; Zhao, Z.Y.; Yang, J.; Wong, S.Y. [Hong Kong Baptist Univ., Hong Kong (China). Sino-Forest Applied Research Centre for Pearl River Delta Environment, Dept. of Biology

    2009-07-01

    This study investigated the feasibility of using microemulsions to enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs). Microemulsions are commonly used in soil washing as a means of enhancing the solubility of hydrophobic pollutants. The microemulsions were composed of Tween-80, 1-pentanol and linseed oil. Phenanthrene (PHE) was dissolved in dichloromethane and added to a glass vial. Microemulsions were added separately to the vials. A high performance liquid chromatograph (HPLC) was used to determine PHE concentrations. The vials were inoculated with an isolated PAH degradative bacterium Bacillus subtilis B-UM. Soil collected from abandoned shipyards in Hong Kong were then spiked with the mixtures and aged for 3 months. One way analysis of variance (ANOVA) analyses were conducted. Results of the study showed that a microemulsion composed of 0.4 Tween-80, 0.1 per cent 1-pentanol, and 0.05 linseed oil effectively enhanced the biodegradation of PHE in the aqueous phase. It was concluded that microemulsions can be used to remediate soils contaminated by PAHs. 26 refs., 2 tabs., 4 figs.

  17. Polycyclic aromatic hydrocarbons in household dust near diesel transport routes.

    Science.gov (United States)

    Kuo, Chung-Yih; Chen, Heng-Chun; Cheng, Fang-Ching; Huang, Li-Ru; Chien, Po-Shan; Wang, Jing-Ya

    2012-02-01

    A river-dredging project has been undertaken in Nantou, Taiwan. A large number of diesel vehicles carrying gravel and sand shuttle back and forth on the main roads. Ten stations along major thoroughfares were selected as the exposure sites for testing, while a small village located about 9 km from a main traffic route was selected as the control site. Levels of household dust loading at the exposure sites (60.3 mg/m(2)) were significantly higher than those at the control site (38.2 mg/m(2)). The loading (μg/m(2)) of t-PAHs (total polycyclic aromatic hydrocarbons) in the household dust at the exposure sites was significantly higher (P < 0.05) than was the case at the control site. The diagnostic ratios of PAHs showed that diesel emissions were the dominant source of PAHs at the exposure sites. The lack of a significant correlation between the concentrations of Fe and t-PAHs suggested that the t-PAHs in household dust might come from diverse sources. However, a significant correlation (P = 0.003) between the concentrations of Mo and t-PAHs implied that the most of the t-PAHs in the household dust might have resulted from diesel emissions. The lifetime cancer risks of BaP(eq) from household dust exposure were markedly higher than those resulting from inhalation exposure.

  18. MONITORING POLYNUCLEAR AROMATIC HYDROCARBONS IN SEDIMENT POREWATER BY SPMD

    Institute of Scientific and Technical Information of China (English)

    朱亚先; 张勇; 庄一廷; Ka-FaiPoon; MichaelH.W.Lam; 洪华生; RudolfS.S.Wu

    2001-01-01

    A new mimic biological Semi-permeable Membrane Device (SPMD) introduced for sampling organic pollutants yielded satisfactory results when it was frrst used as a passive sampler to concentrate and determine 16 kinds of polynuclear aromatic hydrocarbons (PAHs) by means of capillary GC on an HP 5890 GC-FID in coastal sediment perewater. The concentration of PAHs in sediment porewater for naphthalene(N), acenaphthlene(AL), acenaphthene (AE), fluorene (F), phenaphthene(P), anthracene(A), fluoranthene(FA), pyrene(Py), benzo[a]anthracene(B[a]A), chrysene(Chr), benzo[b] fluor- anthene(B[b]F), benzo[k]fluoranthene(B[k]F), benzo[a]pyrene(B[a]P),indeno[1,2,3,-cd]-Pyrene(I[123]P), dibenz[a,h]anthracene(D[ab]A) and benzo[g,h,i] perylene(B[ghi]P) were:50.36, under detection limits(UD), 18.19, 8.41, 8.40, 1.44, UD, 8.01, 524.15, 168.47, 50.13,123.66, 63.48, 27.40, 82.04 and 58,81 ng/L, respectively.

  19. MONITORING POLYNUCLEAR AROMATIC HYDROCARBONS IN SEDIMENT POREWATER BY SPMD

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new mimic biological Semi-permeable Membrane Device (SPMD) introduced for sampling organic pollutants yielded satisfactory results when it was first used as a passive sampler to concentrate and determine 16 kinds of polynuclear aromatic hydrocarbons (PAHs) by means of capillary GC on an HP 5890 GC-FID in coastal sediment porewater. The concentration of PAHs in sediment porewater for naphthalene(N), acenaphthlene(AL), acenaphthene(AE), fluorene(F), phenaphthene(P), anthracene(A), fluoranthene(FA), pyrene(Py), benzo[ a] anthracene( B [a] A), chrysene(Chr), benzo[b]fluor- anthene ( B [ b ] F ), benzo[ k ] fluoranthene ( B [ k ] F ), benzo[ a ] pyrene ( B [ a ] P), indeno [ 1,2,3,-cd]-Pyrene(I[123]P), dibenz[a,h]anthracene(D[ah]A) and benzo[g,h,i] perylene(B[ghi]P) were:50.36, under detection limits( UD), 18.19, 8.41, 8.40, 1.44, UD, 8.01, 524.15, 168.47, 50.13,123.66, 63.48, 27.40, 82.04 and 58,81 ng/L, respectively.

  20. Polycyclic Aromatic Hydrocarbon Ionization Energy Lowering in Water Ices

    Science.gov (United States)

    Gudipati, Murthy S.; Allamandola, Louis J.

    2004-01-01

    In studying various interstellar and solar system ice analogs, we have recently found that upon vacuum ultraviolet photolysis, polycyclic aromatic hydrocarbons (PAHs) frozen in water ice at low temperatures are easily ionized and indefinitely stabilized as trapped ions (Gudipati; Gudipati & Allamandola). Here we report the first experimental study that shows that PAH ionization energy is significantly lowered in PAH/H2O ices, in agreement with recent theoretical work (Woon & Park). The ionization energy (IE) of the PAH studied here, quaterrylene (C40H20, IE = 6.11 eV), is lowered by up to 2.11 eV in water ice. PAH ionization energy reduction in low-temperature water ice substantially expands the astronomical regions in which trapped ions and electrons may be important. This reduction in ionization energy should also hold for other types of trapped species in waterrich interstellar, circumstellar, and solar system ices. Subject headings: ISM: clouds - methods: laboratory - molecular processes - radiation mechanisms: nonthermal -ultraviolet: ISM - ultraviolet: solar system

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

    Science.gov (United States)

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

    2017-01-01

    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.

  2. 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.

  3. Investigation of polycyclic aromatic hydrocarbons from coal gasification

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong-cang; JIN Bao-sheng; ZHONG Zhao-ping; HUANG Ya-ji; XIAO Rui; LI Da-ji

    2005-01-01

    The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The total-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification.

  4. 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.

  5. Anharmonicity and infrared bands of Polycyclic Aromatic Hydrocarbon (PAH) molecules

    Science.gov (United States)

    Petrignani, Annemieke; Maltseva, Elena; Candian, Alessandra; Mackie, Cameron; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander; Oomens, Jos; Buma, Wybren Jan

    2015-08-01

    We present a systematic laboratory study of the CH stretching region in Polycyclic Aromatic Hydrocarbon (PAH) molecules of different shapes and sizes to investigate anharmonic behaviour and address the reliability of the never-validated but universally accepted scaling factors employed in astronomical PAH models. At the same time, new anharmonic theoretical quantum chemistry studies have been performed with the software program Spectro using our experimental data as benchmark. We performed mass and conformational-resolved, high-resolution spectroscopy of cold (~10K) linear and compact PAH molecules starting with naphthalene (C10H8) in the 3-µm CH stretching region. Surprisingly, the measured infrared spectra show many more strong modes than expected. Measurements of the deuterated counterparts demonstrate that these bands are the result of Fermi Resonances. First comparisons with harmonic and anharmonic DFT calculations using Gaussian 09 show that both approximations are not able to reproduce in detail the observed molecular reality. The improved anharmonic calculations performed with Spectro now include the effects of Fermi resonances and have been applied to PAHs for the first time. The analysis of the experimental data is greatly aided by these new theoretical quantum chemistry studies. Preliminary assignments are presented, aided by comparison between the observed rotational contour and the symmetry of candidate bands.

  6. Contamination of rivers in Tianjin, China by polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Z.; Tao, S.; Pan, B.; Fan, W.; He, X.C.; Zuo, Q.; Wu, S.P.; Li, B.G.; Cao, J.; Liu, W.X.; Xu, F.L.; Wang, X.J.; Shen, W.R.; Wong, P.K. [Peking University, Beijing (China). College of Environmental Science

    2005-03-01

    Abstract: Tianjin urban/industrial complex is highly polluted by some persistent organic pollutants. In this study, the levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were tested in sediment, water, and suspended particulate matter (SPM) samples in 10 rivers in Tianjin. The total concentration of 16 PAHs varied from 0.787 to 1943 {mu}g/g dry weight in sediment, from 45.81 to 1272 ng/L in water, and from 0.938 to 64.2 {mu}g/g dry weight in SPM. The levels of PAHs in these media are high in comparison with values reported from other river and marine systems. Variability of total concentrations of PAHs in sediment, water, and SPM from nine different rivers is consistent with each other. No obvious trends of total PAHs concentration variations were found between upstream and downstream sediment, water, and SPM samples for most rivers, which indicate local inputs and disturbances along these rivers. The spatial distributions of three-phase PAHs are very similar to each other, and they are also similar to those found in topsoil. However, their chemical profiles are significantly different from that of topsoil. The change of profiles is consistent with the different aqueous transport capability of 16 PAHs. Low molecular weight PAHs predomination suggests a relatively recent local source and coal combustion source of PAHs in the study area.

  7. Investigation of polycyclic aromatic hydrocarbons from coal gasification.

    Science.gov (United States)

    Zhou, Hong-cang; Jin, Bao-sheng; Zhong, Zhao-ping; Huang, Ya-ji; Xiao, Rui; Li, Da-ji

    2005-01-01

    The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The total-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification.

  8. Polycyclic aromatic hydrocarbons (PAHs) removal by sorption: A review.

    Science.gov (United States)

    Lamichhane, Shanti; Bal Krishna, K C; Sarukkalige, Ranjan

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are organic micro pollutants which are persistent compounds in the environment due to their hydrophobic nature. Concerns over their adverse effects in human health and environment have resulted in extensive studies on various types of PAHs removal methods. Sorption is one of the widely used methods as PAHs possess a great sorptive ability into the solid media and their low aqueous solubility property. Several adsorbent media such as activated carbon, biochar, modified clay minerals have been largely used to remove PAHs from aqueous solution and to immobilise PAHs in the contaminated soils. According to the past studies, very high removal efficiency could be achieved using the adsorbents such as removal efficiency of activated carbon, biochar and modified clay mineral were 100%, 98.6% and >99%, respectively. PAHs removal efficiency or adsorption/absorption capacity largely depends on several parameters such as particle size of the adsorbent, pH, temperature, solubility, salinity including the production process of adsorbents. Although many studies have been carried out to remove PAHs using the sorption process, the findings have not been consolidated which potentially hinder to get the correct information for future study and to design the sorption method to remove PAHs. Therefore, this paper summarized the adsorbent media which have been used to remove PAHs especially from aqueous solutions including the factor affecting the sorption process reported in 142 literature published between 1934 and 2015.

  9. Association of polycyclic aromatic hydrocarbons in housewives' hair with hypertension.

    Science.gov (United States)

    Wang, Bin; Li, Zhiwen; Ma, Yiqiu; Qiu, Xinghua; Ren, Aiguo

    2016-06-01

    The relationship between polycyclic aromatic hydrocarbons (PAHs) and hypertension remains a subject of debate. The aims of this study were to determine an association of concentrations of PAHs in housewives' hair with hypertension risk and the modification effect of single nucleotide polymorphisms (SNPs) related to Phase I metabolism of PAHs. We recruited 405 women for a cross-sectional study in Shanxi Province, China, including 170 with hypertension (the case group) and 235 without hypertension (the control group). We analyzed 26 individual PAHs in hair samples and the SNPs of the genes including cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1), CYP1A2, CYP1B1 and CYP2E1. Our results showed that seven PAHs in hair samples were measured with detection rate >70%. Only acenaphthylene was found to be associated with an increased risk of hypertension with adjustment for the potential confounders following Bonferroni correction, whereas others not. No SNPs of the concerned genes were found to be associated with the risk of hypertension. A multiple interaction effect of PAHs in housewives' hair and SNPs on hypertension risk was not observed. It was concluded that PAHs tended to contribute to the formation of hypertension.

  10. 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.

  11. 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.

  12. Polycyclic aromatic hydrocarbon formation under simulated coal seam pyrolysis conditions

    Institute of Scientific and Technical Information of China (English)

    Liu Shuqin; Wang Yuanyuan; Wang Caihong; Bao Pengcheng; Dang Jinli

    2011-01-01

    Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification.This is an important source of polycyclic aromatic hydrocarbon (PAH) emission in China.Pyrolysis in a coal seam was simulated in a tubular furnace.The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC.The effects of temperature,heating rate,pyrolysis atmosphere,and coal size were investigated.The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas.The 2-ring NaP and the 4-ring Pyr are also of concern.Increasing temperature caused the total PAH yield to go through a minimum.The lowest value was obtained at the temperature of 600 ℃ Higher heating rates promote PAH formation,especially formation of the lower molecular weight PAHs.The typical heating rate in a coal seam,5 ℃/min,results in intermediate yields of PAHs.The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2,which indicates that an air flow through the coal seam accelerates the formation of PAHs.An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and 6-ring PAHs.

  13. 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

    2017-01-01

    Abstract 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. PMID:27897357

  14. Threshold Energies for Single Carbon Knockout from Polycyclic Aromatic Hydrocarbons

    CERN Document Server

    Stockett, M H; Chen, T; de Ruette, N; Giacomozzi, L; Wolf, M; Schmidt, H T; Zettergren, H; Cederquist, H

    2015-01-01

    We have measured absolute cross sections for ultrafast (fs) single-carbon knockout from Polycyclic Aromatic Hydrocarbon (PAH) cations as functions of He-PAH center-of-mass collision energy in the range 10-200 eV. Classical Molecular Dynamics (MD) simulations cover this range and extend up to 10$^5$ eV. The shapes of the knockout cross sections are well described by a simple analytical expression yielding experimental and MD threshold energies of $E_{th}^{Exp}=32.5\\pm 0.4$ eV and $E_{th}^{MD}=41.0\\pm 0.3$ eV, respectively. These are the first measurements of knockout threshold energies for molecules isolated \\emph{in vacuo}. We further deduce semi-empirical (SE) and MD displacement energies --- \\emph{i.e.} the energy transfers to the PAH molecules at the threshold energies for knockout --- of $T_{disp}^{SE}=23.3\\pm 0.3$ eV and $T_{disp}^{MD}=27.0\\pm 0.3$ eV. The semi-empirical results compare favorably with measured displacement energies for graphene $T_{disp}=23.6$ eV [Meyer \\emph{et al.} Phys. Rev Lett. \\tex...

  15. Fibrous adsorbent for removal of aqueous aromatic hydrocarbons.

    Science.gov (United States)

    Jung, Yong-Jun; Kiso, Yoshiaki; Oguchi, Tatsuo; Yamada, Toshiro; Takagi, Hiroo; Nishimura, Kazuyuki

    2007-01-01

    Bundles of a strongly hydrophobic fibrous material (p-phenylene-2,6-benzobisoxazole; PBO; Zylon) were employed as an adsorbent for the removal of aqueous aromatic compounds, because the PBO fibers are too rigid to be woven and did not entrap suspended solids. The removal performance for nine kinds of polyaromatic hydrocarbons (PAHs) and di-(2-ethylhexyl) phthalate (DEHP) was evaluated. PAHs and DEHP at initial concentrations of 50 microg L(-1) were removed at 72.5-99.9% and ca. 95%, respectively, although the removal efficiencies were affected by the phase ratio (fiber weight/solution volume). The logarithm of the partition coefficient (log K) for planar PAHs was linearly correlated with the logarithm of the n-octanol/water partition coefficient (log P), but nonplanar PAHs, such as cis-stilbene, p-terphenyl, and o-terphenyl, showed significantly lower adsorption performance. The adsorbed PAHs were not desorbed effectively with CH3CN, CH2Cl2, and toluene. On the other hand, DEHP was effectively desorbed with methanol.

  16. Aqueous leaching of polycyclic aromatic hydrocarbons from bitumen and asphalt.

    Science.gov (United States)

    Brandt, H C; de Groot, P C

    2001-12-01

    The application of bitumen in, e.g. asphalt roads, roofs and hydraulic applications will lead to the leaching of compounds from the bitumen/asphalt into the environment. Because polycyclic aromatic hydrocarbons (PAHs) are present in bitumen, static and dynamic leach tests have been performed to study the leaching behaviour of this class of compounds. Nine petroleum bitumens covering a representative range of commercially available products and one asphalt made from one of the bitumens have been tested in a static leach test. The asphalt has been also subjected to a dynamic leach test. The main conclusions are that a 30h dynamic leach test is sufficient to determine the equilibrium concentration that will be reached after bitumen or asphalt has been in contact with the water for more than 3-6 days. As an alternative to performing a leach test, this concentration can be calculated from the PAH concentrations in the bitumen, and their distribution coefficients, as calculated here, or from their aqueous solubilities. The equilibrium PAH concentrations in the leach water from bitumens stay well below the surface water limits that exist in several EEC-countries and are also more than an order of magnitude lower than the current EEC limits for potable water.

  17. Separation and analysis of aromatic hydrocarbons from two Chinese coals

    Institute of Scientific and Technical Information of China (English)

    DING Ming-jie; LI Wen-dian; XIE Rui-lun; ZONG Ying; CAI Ke-ying; PENG Yao-li; ZONG Zhi-min; XIE Rui-lun; WEI Xian-yong

    2008-01-01

    Separation and analysis of aromatic hydrocarbons (AHs) from coals is of considerable significance for both fuel and non-fuel use of the coals. In present work two Chinese bituminous coals were selected for separation of AHs by ultrasonic extraction with CS2 followed by column chromatography using hexane as eluent. A series of AHs were separated from the two coals and analyzed by GC/MS. FTIR was employed to characterize the raw coals and the extracted residues. The results of GC/MS analysis show that the separated AHs are mono- to tetracyclic arenes, among which the principle AHs are alkyl naphthalenes and phenanthrenes. Obvious differences in the composition and the structure of AHs exist between the two coals, i.e., the AHs from Tongting coal tend to be higher rings compared to those from Pingshuo coal both from the variety and from the abundance of the AHs. FFIR analysis shows that the raw and extracted coals are similar in terms of functional groups, suggesting that the composition and structure of CS extract, especially the AHs, from coals can be used to interpret the coal structure to some extent.

  18. Magnetic graphene oxide as adsorbent for the determination of polycyclic aromatic hydrocarbon metabolites in human urine.

    Science.gov (United States)

    Zhu, Linli; Xu, Hui

    2014-09-01

    Detection of monohydroxy polycyclic aromatic hydrocarbons metabolites in urine is an advisable and valid method to assess human environmental exposure to polycyclic aromatic hydrocarbons. In this work, novel Fe3O4/graphene oxide composites were prepared and their application in the magnetic solid-phase extraction of monohydroxy polycyclic aromatic hydrocarbons in urine was investigated by coupling with liquid chromatography and mass spectrometry. In the hybrid material, superparamagnetic Fe3O4 nanoparticles provide fast separation to simplify the analytical process and graphene oxide provides a large functional surface for the adsorption. The prepared magnetic nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometry. The experimental conditions were optimized systematically. Under the optimal conditions, the recoveries of these compounds were in the range of 98.3-125.2%, the relative standard deviations ranged between 6.8 and 15.5%, and the limits of detection were in the range of 0.01-0.15 ng/mL. The simple, quick, and affordable method was successfully used in the analysis of human urinary monohydroxy polycyclic aromatic hydrocarbons in two different cities. The results indicated that the monohydroxy polycyclic aromatic hydrocarbons level in human urine can provide useful information for environmental exposure to polycyclic aromatic hydrocarbons.

  19. Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments of the Mediterranean: assessment and source recognition of petroleum hydrocarbons.

    Science.gov (United States)

    El Nemr, Ahmed; El-Sadaawy, Manal M; Khaled, Azza; Draz, Suzanne O

    2013-06-01

    Coastal marine sediment samples were collected from ten sampling stations along the Egyptian Mediterranean coast in April 2010. All sediment samples were analyzed for aliphatic (C7 to C34) and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total aliphatic hydrocarbons ranged from 1621.82 to 9069.99 ng/g (dry weight), while aromatic hydrocarbons (16 PAHs) varied between 208.69 and 1020.02 ng/g with an average of 530.68 ± 225.86 ng/g dwt. Good correlations observed between certain PAH concentrations allowed to identify its origin. The average TOC percent was varied from 0.13 to 1.46 %. Principal component analysis was used to determine the sources of hydrocarbon pollutants in sediments of Mediterranean. Additionally, special PAHs compound ratios suggest the petrogenic origins.

  20. 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...

  1. Source Characterization of Polycyclic Aromatic Hydrocarbons by Using Their Molecular Indices: An Overview of Possibilities

    NARCIS (Netherlands)

    Stogiannidis, E.; Laane, R.

    2014-01-01

    The Polycyclic Aromatic Hydrocarbons (PAHs or polyaromatic hydrocarbons) have been extensively studied to understand their distribution, fate and effects in the environment (Haftka 2009; Laane et al. 1999, 2006, 2013; Okuda et al. 2002; Page et al. 1999; Pavlova and Ivanova 2003; Stout et al. 2001a;

  2. Speciation of atmospheric polycyclic aromatic hydrocarbons (PAHs) present during fog time collected submicron particles.

    Science.gov (United States)

    Singh, Dharmendra Kumar; Sharma, Swati; Habib, Gazala; Gupta, Tarun

    2015-08-01

    Airborne submicron particles (PM1) were collected using PM1 sampler during the fog-dominated days (December 2013-January 2014). PM1 values varied between 58.12 μg/m(3) and 198.75 μg/m(3), and average mass concentration was 162.33 ± 38.25 μg/m(3) while total average concentration of particle-associated polycyclic aromatic hydrocarbon (PAHs) determined was 616.31 ± 30.31 ng/m(3). This is a signal for an alarming high pollution level at this site situated in the Indo-Gangetic Plain (IGP). PAHs were extracted from filters using toluene and acetonitrile. Quantitative measurements of polycyclic aromatic hydrocarbons (PAHs) were carried out using the high performance liquid chromatography (HPLC) technique. The extracts were analyzed for 16 target polycyclic aromatic hydrocarbons (PAHs) including carcinogenic compound benzo(a)pyrene (19.86 ± 38.98 ng/m(3)). Fluoranthene, benzo(a)anthracene, anthracene, and fluorene were the predominant compounds found in the samples collected during foggy days. Based on number of rings, four-ring PAH compounds had maximum contribution (43%) in this fog time collected submicron particles followed by three-ring (21%), five-ring (20%), six-ring (13%), and two-ring (3%), respectively. In winter and foggy days, wood and coal combustion and biomass burning also significantly contribute to the PAH levels. However, diagnostic ratio suggests diesel emissions as the prime source of PAHs at this sampling site.

  3. Polytetrafluoroethylene-jacketed stirrer modified with graphene oxide and polydopamine for the efficient extraction of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Zhang, Zinxin; Mwadini, Mwadini Ahmada; Chen, Zilin

    2016-10-01

    Steel stirrers jacketed with polytetrafluoroethylene can be regarded as an ideal substrate for stirrer bar sorptive extraction. However, it is still a great challenge to immobilize graphene onto a polytetrafluoroethylene stirrer due to the high chemical resistance of the surface of a polytetrafluoroethylene stirrer. We describe here a method to modify the surface of polytetrafluoroethylene stirrers with graphene. In this work, graphene was used as the sorbent due to its excellent adsorption capability for aromatic compounds, such as polycyclic aromatic compounds. Graphene was successfully immobilized onto polytetrafluoroethylene-stirrer by a bio-inspired polydopamine functionalization method. The graphene-modified polytetrafluoroethylene-stirrer shows good stability and tolerance to stirring, ultrasonication, strong acidic and basic solutions, and to organic solvents. The multilayer coating was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. After the optimization of some experimental conditions, the graphene-modified polytetrafluoroethylene stirrer was used for the stirrer bar sorptive extraction of polycyclic aromatic hydrocarbons, in which the binding between the polycyclic aromatic hydrocarbons and the graphene layer was mainly based on π-π stacking and hydrophobic interactions. The graphene-modified polytetrafluoroethylene-stirrer-based stirrer bar sorptive extraction and high-performance liquid chromatography method was developed for the determination of polycyclic aromatic hydrocarbons with great extraction efficiency, with enrichment factors from 18 to 62. The method has low limits of detection of 1-5 pg/mL, wide linear range (5-100 and 10-200 pg/mL), good linearity (R ≥ 0.9957) and good reproducibility (RSD ≤ 6.45%). The proposed method has been applied to determine polycyclic aromatic hydrocarbons in real dust samples. Good recoveries were obtained, ranging from 88.53 to 109.43%.

  4. Depletion of gaseous polycyclic aromatic hydrocarbons by a forest canopy

    Directory of Open Access Journals (Sweden)

    S.-D. Choi

    2008-07-01

    Full Text Available Rapid uptake of gaseous polycyclic aromatic hydrocarbons (PAHs by a forest canopy was observed at Borden in Southern Ontario, Canada during bud break in early spring 2003. High volume air samples were taken on 12 individual days at three different heights (44.4, 29.1, and 16.7 m on a scaffolding tower and on the forest floor below the canopy (1.5 m. Concentrations of PAHs were positively correlated to ambient temperature, resulting from relatively warm and polluted air masses passing over the Eastern United States and Toronto prior to arriving at the sampling site. An analysis of vertical profiles and gas/particle partitioning of the PAHs showed that gaseous PAHs established a concentration gradient with height, whereas levels of particulate PAHs were relatively uniform, implying that only the uptake of gaseous PAHs by the forest canopy was sufficiently rapid to be observed. Specifically, the gaseous concentrations of intermediate PAHs, such as phenanthrene, anthracene, and pyrene, during budburst and leaf emergence were reduced within and above the canopy. When a gradient was observed, the percentage of PAHs on particles increased at the elevations experiencing a decrease in gas phase concentrations. The uptake of intermediate PAHs by the canopy also led to significant differences in gaseous PAH composition with height. These results are the most direct evidence yet of the filter effect of forest canopies for gaseous PAHs in early spring. PAH deposition fluxes and dry gaseous deposition velocities to the forest canopy were estimated from the concentration gradients.

  5. Estimation of Chronic Personal Exposure to Airborne Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Choi, Hyunok; Zdeb, Michael; Perera, Frederica; Spengler, John

    2015-01-01

    Background Polycyclic aromatic hydrocarbons (PAH) exposure from solid fuel burning represents an important public health issue for the majority of the global population. Yet, understanding of individual-level exposures remains limited. Objectives To develop regionally adaptable chronic personal exposure model to pro-carcinogenic PAH (c-PAH) for the population in Kraków, Poland. Methods We checked the assumption of spatial uniformity in eight c-PAH using the coefficients of divergence (COD), a marker of absolute concentration differences. Upon successful validation, we developed personal exposure models for eight pro-carcinogenic PAH by integrating individual-level data with area-level meteorological or pollutant data. We checked the resulting model for accuracy and precision against home outdoor monitoring data. Results During winter, COD of 0.1 for Kraków suggest overall spatial uniformity in the ambient concentration of the eight c-PAH. The three models that we developed were associated with index of agreement approximately equal to 0.9, root mean square error < 2.6 ng/m3, and 90th percentile of absolute difference ≤ 4 ng/m3 for the predicted and the observed concentrations for eight pro-carcinogenic PAH. Conclusions Inexpensive and logistically feasible information could be used to estimate chronic personal exposure to PAH profiles, in lieu of costly and labor-intensive personal air monitoring at wide scale. At the same time, thorough validation through direct personal monitoring and assumption checking are critical for successful model development. PMID:25965038

  6. 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.

  7. Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability

    Science.gov (United States)

    Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.

    2013-01-01

    Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 through 2007 and during 2010) using household vacuum cleaners, and measured 12 PAHs using gas chromatography–mass spectrometry. We used a random- and a mixed-effects model for each PAH to apportion observed variance into four components and to identify sources of variability. Results: Median concentrations for individual PAHs ranged from 10 to 190 ng/g of dust. For each PAH, total variance was apportioned into regional variability (1–9%), intraregional between-household variability (24–48%), within-household variability over time (41–57%), and within-sample analytical variability (2–33%). Regional differences in PAH dust levels were associated with estimated ambient air concentrations of PAH. Intraregional differences between households were associated with the residential construction date and the smoking habits of residents. For some PAHs, a decreasing time trend explained a modest fraction of the within-household variability; however, most of the within-household variability was unaccounted for by our mixed-effects models. Within-household differences between sampling rounds were largest when the interval between dust sample collections was at least 6 years in duration. Conclusions: Our findings indicate that it may be feasible to use residential dust for retrospective assessment of PAH exposures in studies of health effects. PMID:23461863

  8. Polycyclic Aromatic Hydrocarbon and Metal Concentrations in Imported Canned Maize

    Directory of Open Access Journals (Sweden)

    Embbey K Ossai

    2014-08-01

    Full Text Available Concentrations and profile of polycyclic aromatic hydrocarbons(PAHs and metals (Cd, Pb, Ni, Cr, Fe and Mn were determined in selected brands of canned maize in the Nigeria market with a view to providing information on the hazards associated with the consumption of these products. The measurement of the concentrations of PAHs was carried out by using a gas chromatography equipped with flame ionization detector (GC-FID after extraction by ultra-sonication with acetone/dichloromethane and clean-up. The 16 PAH concentrations varied between 45.1 and 335.7 µg/kg. The concentrations of the indicators for occurrence and effects of PAHs in food varied from 3.6 to 114.5 µg/kg for BaP, 6.4 to 168.2 µg/kg for PAH2, 11.8 to 232.7 µg/kg for PAH4 and 19.4 to 327.3 µg/kg for PAH8. The concentrations of metals were determined by using atomic absorption spectrometry after acid digestion. The concentrations of metals in these samples ranged from <0.05 to 0.9 µg/g for Cd; 5.0 to 8.0 µg/g for Pb, 0.8 to 1.7 µg/g for Fe while Cr and Mn were less than the limits of quantification (<0.05 µg/g. The concentrations of Cd and Pb in these canned maize samples were above their permissible limits for foods.

  9. Near Infrared Spectra of Large Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Mattioda, A. L.; Hudgins, D. M.; Bauschlicher, C. W.; Allamandola, L. J.

    The widespread, mid-IR interstellar emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 microns are generally attributed to vibrationally excited polycyclic aromatic hydrocarbons (PAHs). Since these features typcially originate from radiation-rich regions, it has been generally thought that UV photons must dominate the interstellar excitation process since PAHs have very strong UV absorption bands. However, observations have shown that lower energy photons can also pump the emission (Aitken and Roche, Uchida and Sellgren), raising questions about the PAH model. Although it has long been known that larger PAHs should absorb at longer wavelengths (e.g. Schutte et. al., Salama et al., Li and Draine) data was not available for the isolated, neutral and ionized PAHs of sizes comparable to those thought responsible for the interstellar emission features. Here the matrix-isolated near-IR (NIR) spectra (from 0.7 to 2.5 microns) are presented for the anions and cations of PAHs ranging in size from C34H16 to C50H22. These molecules are characterized by strong absorption bands in this region, bands that can account for the emission of the interstellar features from UV poor regions. These NIR PAH transitions could also contribute to the extinction curve associated with the diffuse interstellar medium. For example, band overlap, as expected from a mixture of PAHs, can contribute to the continuum. Overlapping broad bands could lead to slight undulations in the continuum reminiscent of the Very Broad Structure (VBS, e.g. Hayes et al.). Furthermore, as previously pointed out, individual PAH bands may contribute to the diffuse interstellar band (DIB) spectrum (e.g. Romanini)

  10. The C--H Stretching Features at 3.2--3.5 Micrometer of Polycyclic Aromatic Hydrocarbons with Aliphatic Sidegroups

    CERN Document Server

    Yang, Xuejuan; Glaser, Rainer; Zhong, Jianxin

    2016-01-01

    The so-called unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 micrometer are ubiquitously seen in a wide variety of astrophysical regions. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, e.g., polycyclic aromatic hydrocarbon (PAH) molecules. The 3.3 micrometer aromatic C--H stretching feature is often accompanied by a weaker feature at 3.4 micrometer. The latter 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 micrometer aromatic C--H feature to that of the 3.4 micrometer aliphatic C--H feature allows one to estimate the aliphatic fraction of the UIE carriers, provided that the intrinsic oscillator strengths of the 3.3 micrometer aromatic C--H stretch (A3.3) and the 3.4 micrometer aliphatic C--H stretch (A3.4) are known. While previous studies on the aliphatic fraction of the UIE carriers were mostly based on the A3.4...

  11. Atmospheric photochemistry of aromatic hydrocarbons: Analysis of OH budgets during SAPHIR chamber experiments and evaluation of MCMv3.2

    Science.gov (United States)

    Nehr, S.; Bohn, B.; Brauers, T.; Dorn, H.; Fuchs, H.; Häseler, R.; Hofzumahaus, A.; Li, X.; Lu, K.; Rohrer, F.; Tillmann, R.; Wahner, A.

    2012-12-01

    Aromatic hydrocarbons, almost exclusively originating from anthropogenic sources, comprise a significant fraction of volatile organic compounds observed in urban air. The photo-oxidation of aromatics results in the formation of secondary pollutants and impacts air quality in cities, industrialized areas, and districts of dense traffic. Up-to-date photochemical oxidation schemes of the Master Chemical Mechanism (MCMv3.2) exhibit moderate performance in simulating aromatic compound degradation observed during previous environmental chamber studies. To obtain a better understanding of aromatic photo-oxidation mechanisms, we performed experiments with a number of aromatic hydrocarbons in the outdoor atmosphere simulation chamber SAPHIR located in Jülich, Germany. These chamber studies were designed to derive OH turnover rates exclusively based on experimental data. Simultaneous measurements of NOx (= NO + NO2), HOx (= OH + HO2), and the total OH loss rate constant k(OH) facilitate a detailed analysis of the OH budgets during photo-oxidation experiments. The OH budget analysis was complemented by numerical model simulations using MCMv3.2. Despite MCM's tendency to overestimate k(OH) and to underpredict radical concentrations, the OH budgets are reasonably balanced for all investigated aromatics. However, the results leave some scope for OH producing pathways that are not considered in the current MCMv3.2. An improved reaction mechanism, derived from MCMv3.2 sensitivity studies, is presented. The model performance is basically improved by changes of the mechanistic representation of ring fragmentation channels.

  12. Identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons in a complex mixture of polycyclic aromatic hydrocarbons from coal tar.

    Science.gov (United States)

    Oña-Ruales, Jorge O; Ruiz-Morales, Yosadara; Wise, Stephen A

    2016-04-15

    A methodology for the characterization of groups of polycyclic aromatic hydrocarbons (PAHs) using a combination of normal phase liquid chromatography with ultraviolet-visible spectroscopy (NPLC/UV-vis) and gas chromatography with mass spectrometry (GC/MS) was used for the identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons, PAHs, in standard reference material (SRM) 1597a, complex mixture of PAHs from coal tar. The NPLC/UV-vis isolated the fractions based on the number of aromatic carbons and the GC/MS allowed the identification and quantification of five of the nine C26H14 PAH isomers; naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene using a retention time comparison with authentic reference standards. For the other four benzenoid isomers with no available reference standards the following two approaches were used. First, the annellation theory was used to achieve the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene, and second, the elution distribution in the GC fractions was used to support the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene and to reach the tentative identifications of dibenzo[a,ghi]perylene, naphtho[7,8,1,2,3-pqrst]pentaphene, and anthra[2,1,9,8-opqra]naphthacene. It is the first time that naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene are quantified, and the first time that benzo[qr]naphtho[3,2,1,8-defg]chrysene is potentially identified, in any sample, in any context.

  13. Effect of the Structure of Cations and Anions of Ionic Liquids on Separation of Aromatics from Hydrocarbon Mixtures

    Institute of Scientific and Technical Information of China (English)

    Liu Yansheng; Zhang Zhongxin; Zhang Guofu; Liu Zhichang; Hu Yufeng; Shi Quan; Ji Dejun

    2006-01-01

    The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The results showed that the corresponding separation factors were considerably larger than those of the traditional solvents (Benzene+Hexane+sulfolane), and that the ionic liquids could be used as novel solvents for the separation of aromatics from hydrocarbon mixtures. The key parameters governing the ability of ionic liquids for separating aromatics from hydrocarbon sources were investigated. It was found that the effectiveness of the ionic liquids, based on the same anion, changed in the cation order of [BIqu]+< [BPy]+< [BMIM]+. The selectivity of the ionic liquid toward aromatics decreased apparently with the increasing length of the substituted alkyl chain of its cationic head ring. The separation factors, based on the same cation, changed in the anion order of [Tf2N]-<[PF6]-<[BF4]-<[C2H5SO4]-. The solubilities of the aromatics were greater in the ionic liquids based on the former three anions than that in the ionic liquids involving [C2H5SO4]-.

  14. Retention mechanism for polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography with monomeric stationary phases.

    Science.gov (United States)

    Rafferty, Jake L; Siepmann, J Ilja; Schure, Mark R

    2011-12-23

    Reversed-phase liquid chromatography (RPLC) is the foremost technique for the separation of analytes that have very similar chemical functionalities, but differ only in their molecular shape. This ability is crucial in the analysis of various mixtures with environmental and biological importance including polycyclic aromatic hydrocarbons (PAHs) and steroids. A large amount of effort has been devoted to studying this phenomenon experimentally, but a detailed molecular-level description remains lacking. To provide some insight on the mechanism of shape selectivity in RPLC, particle-based simulations were carried out for stationary phases and chromatographic parameters that closely mimic those in an experimental study by Sentell and Dorsey [J. Chromatogr. 461 (1989) 193]. The retention of aromatic hydrocarbons ranging in size from benzene to the isomeric PAHs of the formula C(18)H(12) was examined for model RPLC systems consisting of monomeric dimethyl octadecylsilane (ODS) stationary phases with surface coverages ranging from 1.6 to 4.2 μmol/m(2) (i.e., stationary phases yielding low to intermediate shape selectivity) in contact with a 67/33 mol% acetonitrile/water mobile phase. The simulations show that the stationary phase acts as a very heterogeneous environment where analytes with different shapes prefer different spatial regions with specific local bonding environments of the ODS chains. However, these favorable retentive regions cannot be described as pre-existing cavities because the chain conformation in these local stationary phase regions adapts to accommodate the analytes.

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

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    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.

  16. Bioremediation of Mixtures of High Molecular Weight Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Xu, H.; Wu, J.; Shi, X.; Sun, Y.

    2014-12-01

    Although bioremediation has been considered as one of the most promising means to remove polycyclic aromatic hydrocarbons (PAHs) from polluted environments, the efficacy of PAHs bioremediation still remains challenged, especially for high molecular weight PAHs (HMW PAHs) and their mixtures. This study was focused on (a) isolation and characterization of pure strain and mixed microbial communities able to degrade HMW PAHs and (b) further evaluation of the ability of the isolated microbes to degrade HMW PAHs mixtures in the absence and presence of indigenous flora. Fluoranthene, benzo[b]fluoranthene and pyrene were selected as the representative HMW PAHs in this study. A pure bacterial strain, identified as Herbaspirillum chlorophenolicum FA1, was isolated from activated sludge. A mixed bacterial community designated as consortium-4 was isolated from petroleum contaminated soils, containing Pseudomonas sp. FbP1、Enterobacter sp. FbP2、Hydrogenophaga sp. FbP3 and Luteolibacter pohnpeiensis. FbP4. To our knowledge, this is the first study to demonstrate that bacterial strains of Herbaspirillum chlorophenolicum FA1 and Luteolibacter pohnpeiensis. FbP4 can also degrade fluoranthene, benzo[b]fluoranthene and pyrene. Experiment results showed that both strain FA1 and consortium-4 could degrade fluoranthene, benzo[b]fluoranthene and pyrene within a wide range of temperature, pH and initial PAHs concentration. Degradation of HMW PAHs mixtures (binary and ternary) demonstrated the interactive effects that can alter the rate and extent of biodegradation within a mixture. The presence of indigenous flora was found to either increase or decrease the degradation of HMW PAHs, suggesting possible synergistic or competition effects. Biodegradation kinetics of HMW PAHs for sole substrates, binary and ternary systems was evaluated, with the purpose to better characterize and compare the biodegradation process of individual HMW PAH and mixtures of HMW PAHs. Results of this study

  17. Metabolism of mutagenic polycyclic aromatic hydrocarbons by photosynthetic algal species.

    Science.gov (United States)

    Schoeny, R; Cody, T; Warshawsky, D; Radike, M

    1988-02-01

    Polycyclic aromatic hydrocarbons (PAH) known to produce carcinogenic and mutagenic effects have been shown to contaminate waters, sediments and soils. While it is accepted that metabolites of these compounds are responsible for most of their biological effects in mammals, their metabolism, and to a large extent their bioactivity, in aquatic plants have not been explored. Cultures of photosynthetic algal species were assayed for their ability to metabolize benzo[a]pyrene (BaP), a carcinogenic PAH under conditions which either permitted (white light) or disallowed (gold light) photooxidation of the compound. Growth of Selenastrum capricornutum, a fresh-water green alga, was completely inhibited when incubated in white light with 160 micrograms BaP/l medium. By contrast concentrations at the upper limit of BaP solubility in aqueous medium had no effect on algal growth when gold light was used. BaP quinones and phenol derivatives were found to inhibit growth of Selenastrum under white light incubation. BaP phototoxicity and metabolism were observed to be species-specific. All 3 tested species of the order Chlorococcales were growth-inhibited by BaP in white light whereas neither the green alga Chlamydomonas reinhardtii nor a blue-green, a yellow-green or an euglenoid alga responded in this fashion. Assays of radiolabeled BaP metabolism in Selenastrum showed that the majority of radioactivity associated with BaP was found in media as opposed to algal cell pellets, that the extent of metabolism was BaP concentration dependent, and that the proportion of various metabolites detected was a function of the light source. After gold light incubation, BaP diols predominated while after white light treatment at equal BaP concentrations, the 3,6-quinone was found in the highest concentration. Extracted material from algal cell pellets and from media was tested for mutagenicity in a forward mutation suspension assay in Salmonella typhimurium using resistance to 8-azaguanine for

  18. New biomarkers of occupational exposure to polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Seidel, Albrecht; Spickenheuer, Anne; Straif, Kurt; Rihs, Hans-Peter; Marczynski, Boleslaw; Scherenberg, Michael; Dettbarn, Gerhard; Angerer, Jürgen; Wilhelm, Michael; Brüning, Thomas; Jacob, Jürgen; Pesch, Beate

    2008-01-01

    Polycyclic aromatic hydrocarbons (PAH) are metabolized in a complex manner. Although biological activity is associated with diol-epoxide formation, phenolic metabolites have predominantly been used in human biomonitoring. In this study monohydroxylated and new metabolites were characterized as biomarkers for occupational PAH exposure. In 97 male workers, personal exposure to 16 airborne PAH compounds was measured during shift. In postshift urine, 1-hydroxypyrene and 1,6- and 1,8-dihydroxypyrene (1-OHP, DiOHP) were determined as metabolites of pyrene (P), and the sum of 1-, 2-, 3-, 4-, and 9-hydroxyphenanthrenes (OHPHE), and PHE-dihydrodiols (PHED) as metabolites of phenanthrene (PHE). The referent group comprised 21 nonsmoking construction workers. Median (interquartile range) shift concentrations of airborne P and PHE were 1.46 (0.62-4.05 microg/m(3)) and 10.9 (3.69-23.77 microg/m(3)), respectively. The corresponding parameters were 3.86 (2.08-7.44) microg/g creatinine (crn) for 1-OHP, 0.66 (0.17-1.65) microg/g crn for DiOHP, 11.44 (5.21-34.76) microg/g crn for OHPHE, and 12.28 (3.3-97.76) microg/g crn for PHED in PAH-exposed workers. The median levels of 1-OHP and OHPHE were 0.09 (0.08-0.17 microg/m(3)) and 0.59 (0.45-1.39 microg/m(3)), respectively, in the referents. PHE correlated significantly with OHPHE and PHED, and P with 1-OHP but not with DiOHP. Under a doubling of PHE, OHPHE increased by a factor of 1.56 and PHED by 1.57. With a doubling of P, 1-OHP rose by 1.31 and DiOHP by 1.27. P is predominantly metabolized into 1-OHP, whereas PHE is metabolized equally into OHPHE and PHED. Thus metabolites of PHE were found as reliable biomarkers for PAH exposure.

  19. Emissions of polycyclic aromatic hydrocarbons from coking industries in China

    Institute of Scientific and Technical Information of China (English)

    Ling Mu; Lin Peng; Junji Cao; Qiusheng He; Fan Li; Jianqiang Zhang; Xiaofeng Liu

    2013-01-01

    This study set out to assess the characteristics of polycyclic aromatic hydrocarbon (PAH) emission from coking industries,with field samplings conducted at four typical coke plants.For each selected plant,stack flue gas samples were collected during processes that included charging coal into the ovens (CC),pushing coke (PC) and the combustion of coke-oven gas (CG).Sixteen individual PAHs on the US EPA priority list were analyzed by gas chromatography/mass spectrometry (GC/MS).Results showed that the total PAH concentrations in the flue gas ranged from 45.776 to 414.874 μg/m3,with the highest emission level for CC (359.545 μg/m3).The concentration of PAH emitted from the CC process in CP1 (stamp charging) was lower than that from CP3 and CP4 (top charging).Low-molecular-weight PAHs (i.e.,two-to three-ring PAHs) were predominant contributors to the total PAH contents,and Nap,AcPy,Flu,PhA,and AnT were found to be the most abundant ones.Total BaPeq concentrations for CC (2.248 iμg/m3) were higher than those for PC (1.838 μg/m3) and CG (1.082 μg/m3),and DbA was an important contributor to carcinogenic risk as BaP in emissions from coking processes.Particulate PAH accounted for more than 20% of the total BaPeq concentrations,which were significantly higher than the corresponding contributions to the total PAH mass concentration (5%).Both particulate and gaseous PAH should be taken into consideration when the potential toxicity risk of PAH pollution during coking processes is assessed.The mean total-PAH emission factors were 346.132 and 93.173 μg/kg for CC and PC,respectively.

  20. 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

  1. Contribution of methyl group to secondary organic aerosol formation from aromatic hydrocarbon photooxidation

    Science.gov (United States)

    Li, Lijie; Qi, Li; Cocker, David R.

    2017-02-01

    The complete atmospheric oxidation pathways leading to secondary organic aerosol remain elusive for aromatic compounds including the role of methyl substitutes on oxidation. This study investigates the contribution of methyl group to Secondary Organic Aerosol (SOA) formation during the photooxidation of aromatic hydrocarbons under low NOx condition by applying methyl carbon labeled aromatic hydrocarbons ((13C2) m-xylene and (13C2) p-xylene). Particle and gas phase oxidation products are analyzed by a series of mass spectrometers (HR-TOF-AMS, PTR-MS and SIFT-MS). The methyl group carbon containing oxidation products partition to the particle-phase at a lower rate than the carbons originating from the aromatic ring as a result of ring opening reactions. Further, the methyl carbon in the original aromatic structure is at least 7 times less likely to be oxidized when forming products that partition to SOA than the aromatic ring carbon. Therefore, oxidation of the methyl group in xylenes exerts little impact on SOA formation in current study. This study provides supporting evidence for a recent finding - a similarity in the SOA formation and composition from aromatic hydrocarbons regardless of the alkyl substitutes.

  2. Historical polycyclic aromatic and petrogenic hydrocarbon loading in Northern Central Gulf of Mexico shelf sediments

    Energy Technology Data Exchange (ETDEWEB)

    Overton, E.B.; Ashton, B.M.; Miles, M.S. [Louisiana State University, Baton Rouge, LA (United States). Dept. of Environmental Studies

    2005-10-01

    The distribution of selected hydrocarbons within ten dated sediment cores taken from the Mississippi River Bight off coastal Louisiana suggests a chronic contaminant loading from several sources including the river itself, oil and gas exploration in the central Gulf of Mexico (GOM) shelf area, and natural geologic hydrocarbon seeps. Data were grouped as either total polycyclic aromatic hydrocarbons (PAH's), which were indicative of pyrogenic PAH's; or estimated total hopanes (indicative of petrogenic hydrocarbons). The total PAH concentrations and estimated total hopanes begin increasing above background levels (approximately 200 ng g{sup -1}) after the 1950s. The distribution of these hydrocarbons and hopanes within the dated sediment cores suggests that the Mississippi River is a regional source of pyrogenic PAH's, and that the hopanes are from natural geologic hydrocarbon seeps, oil and gas exploration in the GOM, or both. (author)

  3. Source apportionment of polycyclic aromatic hydrocarbons in surface soil in Tianjin, China

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Q.; Duan, Y.H.; Yang, Y.; Wang, X.J.; Tao, S. [Peking University, Beijing (China)

    2007-05-15

    Principal component analysis and multiple linear regression were applied to apportion sources of polycyclic aromatic hydrocarbons (PAHs) in surface soils of Tianjin, China based on the measured PAH concentrations of 188 surface soil samples. Four principal components were identified representing coal combustion, petroleum, coke oven plus biomass burning, and chemical industry discharge, respectively. The contributions of major sources were quantified as 41% from coal, 20% from petroleum, and 39% from coking and biomass, which are compatible with PAH emissions estimated based on fuel consumption and emission factors. When the study area was divided into three zones with distinctive differences in soil PAH concentration and profile, different source features were unveiled. For the industrialized Tanggu-Hangu zone, the major contributors were coking (43%), coal (37%) and vehicle exhaust (20%). In rural area, however, in addition to the three main sources, biomass burning was also important (13%). In urban-suburban zone, incineration accounted for one fourth of the total.

  4. Fast automated dual-syringe based dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Guo, Liang; Tan, Shufang; Li, Xiao; Lee, Hian Kee

    2016-03-18

    An automated procedure, combining low density solvent based solvent demulsification dispersive liquid-liquid microextraction (DLLME) with gas chromatography-mass spectrometry analysis, was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Capitalizing on a two-rail commercial autosampler, fast solvent transfer using a large volume syringe dedicated to the DLLME process, and convenient extract collection using a small volume microsyringe for better GC performance were enabled. Extraction parameters including the type and volume of extraction solvent, the type and volume of dispersive solvent and demulsification solvent, extraction and demulsification time, and the speed of solvent injection were investigated and optimized. Under the optimized conditions, the linearity ranged from 0.1 to 50 μg/L, 0.2 to 50 μg/L, and 0.5 to 50 μg/L, depending on the analytes. Limits of detection were determined to be between 0.023 and 0.058 μg/L. The method was applied to determine PAHs in environmental water samples.

  5. Availability of polycyclic aromatic hydrocarbons in aging soils

    Energy Technology Data Exchange (ETDEWEB)

    Ling Wanting; Zeng Yuechun; Gao Yanzheng; Dang Hongjiao; Zhu Xuezhu [Coll. of Resource and Environmental Sciences, Nanjing Agricultural Univ. (China)

    2010-07-15

    Purpose: The soil contamination by hydrophobic organic contaminants (HOCs), such as polycyclic aromatic hydrocarbons (PAHs), poses great threats to human health and ecological security and attracts worldwide concerns. The total HOC concentrations overestimate its available fraction to the soil biota. Increased understanding of the availabilities of PAHs in soil environment will have considerable benefits for their risk assessment and be very instructive to food safety and remediation strategies in contaminated sites. However, the availability of PAHs in aging soils and particularly the correlations of the availabilities with their forms in soils have yet to be elucidated. In this work, the availabilities of PAHs in aging soils were evaluated using a sequential mild extraction technique. Materials and methods: Four typical zonal soils in China previously free of PAHs were collected from A (0-20 cm) horizon, air-dried, and sieved. Soils were spiked with a solution of phenanthrene and pyrene as representative PAHs in acetone. After the acetone evaporated off, the treated soils were progressively diluted with unspiked soils and sieved again several times to homogenize the soil samples. The forms of PAHs in soils were experimented using microcosms that are similar to those reported in literature. Various treated soils were packed into amber glass microcosms (each with 25 g soil). Three replications were given for each treatment. NaN{sub 3} solution (0.5%) was added to some microcosms in order to get the microbe-inhibited treatments. The soil water contents were adjusted to be 20% of soil water-holding capacity. After incubation for 0, 2, 4, 8, 12, and 16 weeks in microcosms with a temperature of 25 C, the soils were sampled. PAHs were then extracted by a sequential mild extraction technique, and their forms and availabilities were determined. Results and discussion: The available residual concentrations of phenanthrene and pyrene generally decreased with aging time, and

  6. Analysis of coal tar polycyclic aromatic hydrocarbon LC-fractions by capillary SFC on a liquid crystalline stationary phase

    Energy Technology Data Exchange (ETDEWEB)

    Kithinji, J.P.; Raynor, M.W.; Egia, B.; Davies, I.L.; Bartle, K.D.; Clifford, A.A. (University of Leeds, Leeds (UK). School of Chemistry)

    1990-01-01

    Supercritical fluid chromatography (SFC) on a capillary column coated with a smectic mesomorphic crystalline phase is shown to exhibit a typical turnover effect (retention versus column temperature) for polycyclic aromatic hydrocarbons (PAHs) at lower temperatures than are found on a methylpolysiloxane phase. Liquid chromatography is used to separate various fractions from a coal tar, which are analyzed by high resolution capillary SFC. Different density and temperature programs were investigated to optimize the separations. Simultaneous density and temperature programs gave the best results, and this is thought to be due to increased solute diffusion coefficients which yield highly efficient separations for the high molecular weight polycyclic aromatic hydrocarbons. The separation mechanism is based on the shape of the liquid crystalline phase, solubility, volatility, and molecular geometry of the PAHs.

  7. Reduced kinetic mechanism of n-heptane oxidation in modeling polycyclic aromatic hydrocarbon formation in opposed-flow diffusion flames

    Institute of Scientific and Technical Information of China (English)

    Beijing ZHONG; Jun XI

    2008-01-01

    A reduced mechanism, which could couple with the multidimensional computational fluid dynamics code for quantitative description of a reacting flow, was developed for chemical kinetic modeling of polycyclic aro-matic hydrocarbon formation in an opposed-flow dif-fusion flame. The complete kinetic mechanism, which comprises 572 reactions and 108 species, was reduced to a simplified mechanism that includes only 83 reactions and 56 species through sensitivity analysis. The results computed via this reduced mechanism are nearly indistin-guishable from those via the detailed mechanism, which demonstrate that the model based on this reduced mech-anism can properly describe n-heptane oxidation chem-istry and quantitatively predict polycyclic aromatic hydrocarbon (such as benzene, naphthalene, phenan-threne and pyrene) formation in opposed-flow diffusion flames.

  8. Sedimentary record of polycyclic aromatic hydrocarbons in Lake Erhai,Southwest China

    Institute of Scientific and Technical Information of China (English)

    Jianyang Guo; Zhang Liang; Haiqing Liao; Zhi Tang; Xiaoli Zhao; Fengchang Wu

    2011-01-01

    The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in a sediment core from Lake Erhal in Southwest China using gas-chromatography/mass spectrometry (GC/MS) method.The total organic carbon (TOC) normalized total PAHs concentrations (sum of US Environmental Protection Agency proposed 16 priority PAHs) ranged from 31.9 to 269 μg/g dry weight (dw),and were characterized by a slowly increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments.The PAHs in the sediments were dominated by low molecular weight (LMW) PAHs,suggesting that the primary source of PAHs was low- and moderate temperature combustion processes.However,both the significant increase in high molecular weight (HMW) PAHs in the upper sediments and the vertical profile of diagnostic ratios pointed out a change in the sources of PAHs from low-temperature combustion to high-temperature combustion.The ecotoxicological assessment based on consensus-based sediment quality guidelines implied that potential adverse biological impacts were possible for benzo(ghi)perylenelene and most LMW PAHs.In addition,the total BaP equivalent quotient of seven carcinogenic polycyclic aromatic hydrocarbons (BaA,CHr,BbF,BkF,BaP,DBA and INP) was 106.1 ng/g,according to the toxic equivalency factors.Although there was no great biological impact associated with the HMW PAlls,great attention should be paid to these PAH components based on their rapid increase in the upper sediments.

  9. Occurrence of polycyclic aromatic hydrocarbons (PAHs) in seawater from the Western Taiwan Strait, China.

    Science.gov (United States)

    Wu, Yu-Ling; Wang, Xin-Hong; Li, Yong-Yu; Hong, Hua-Sheng

    2011-01-01

    Seawater samples (including surface water and bottom water) were collected from the Western Taiwan Strait (WTS) during June 24-25, 2009; polycyclic aromatic hydrocarbons (PAHs) in dissolved phase and particulate phase were analyzed, respectively. The results showed that the total concentrations of PAHs in the dissolved phase and particulate phase were ranged from 12.3 to 58.0 ng L(-1), and 10.3-45.5 ng L(-1), which showed a low-middle contamination level in the China Seas. The spatial variability of PAHs may be related to the complicated currents of WTS, especially the Min-Zhe coastal current. PAHs diagnostic ratios suggested that PAHs mainly originated from the inputs of pyrolytic (combustion) sources, which might be contributed to land-based atmospheric deposition. The particle-water partition coefficients of individual PAH showed that partitions were not correlated with suspended particulate matter content, dissolved organic carbon or salinity, similar to the Yangtze coastal area.

  10. Approaches for externally validated QSAR modelling of Nitrated Polycyclic Aromatic Hydrocarbon mutagenicity.

    Science.gov (United States)

    Gramatica, P; Pilutti, P; Papa, E

    2007-01-01

    Nitrated Polycyclic Aromatic Hydrocarbons (nitro-PAHs), ubiquitous environmental pollutants, are recognized mutagens and carcinogens. A set of mutagenicity data (TA100) for 48 nitro-PAHs was modeled by the Quantitative Structure-Activity Relationships (QSAR) regression method, and OECD principles for QSAR model validation were applied. The proposed Multiple Linear Regression (MLR) models are based on two topological molecular descriptors. The models were validated for predictivity by both internal and external validation. For the external validation, three different splitting approaches, D-optimal Experimental Design, Self Organizing Maps (SOM) and Random Selection by activity sampling, were applied to the original data set in order to compare these methodologies and to select the best descriptors able to model each prediction set chemicals independently of the splitting method applied. The applicability domain was verified by the leverage approach.

  11. [Limit values for polycyclic aromatic hydrocarbons in soil of children's playgrounds--basic criteria and recommendations].

    Science.gov (United States)

    Roscher, E; Liebl, B; Schwegler, U; Schmied, R; Kerscher, G

    1996-01-01

    Elevated concentrations of polycyclic aromatic hydrocarbons (PAK) are often found in the soil of former waste disposal sites, industrial areas, etc. It is desirable and useful to determine orientation values to facilitate and unify the evaluation of contaminations under the aspects of present or planned uses of an area, health protection and decision-making on remedial measures. In the present paper we wish to draw attention to, and discuss problems resulting from, particular characteristics of PAK, e.g. the toxicological property "complete carcinogens" or the necessity of taking into account oral, inhalative and dermal exposure of children on a playground. Based on the discussion, orientation values for benzo[a]pyrene and PAK ("normal" pattern) of 0.5 mg/kg soil and 5 mg/kg soil, respectively, are recommended for top soil of vegetation-free playgrounds. In comparison, deductions carried out by other working groups are presented.

  12. The phototoxicity of polycyclic aromatic hydrocarbons: a theoretical study of excited states and correlation to experiment.

    Science.gov (United States)

    Betowski, Leon D; Enlow, Mark; Riddick, Lee

    2002-06-01

    Investigators using models to determine the phototoxic effects of sunlight on polycyclic aromatic hydrocarbons (PAHs) have invoked the excited states of the molecule as important in elucidating the mechanism of these reactions. Energies of actual excited states were calculated for ten PAHs by several ab initio methods. The main method used for these calculations was the Configuration Interaction approach, modeling excited states as combinations of single substitutions out of the Hartree-Fock ground state. These calculations correlate well with both experimentally measured singlet and triplet state energies and also previous HOMO-LUMO gap energies that approximate the singlet state energies. The excited state calculations then correlate well with general models of photo-induced toxicity based for the PAHs.

  13. [Symptoms of atopy in persons exposed to chronic immunosuppression of polycyclic aromatic hydrocarbons].

    Science.gov (United States)

    Szczeklik, J; Kowalczyk, E; Gałuszka, Z

    1995-01-01

    The frequency of the atopy symptoms was estimated in 126 coke oven workers chronically exposed to polycyclic aromatic hydrocarbons (PAHs). The assessment was based on questionnaire, point skin tests with the allergens of dust, feathers, mould grass as well as on the measurements of total blood serum IgE concentration. The control group was consisted of 75 men, workers of cold rolling mill division where the environmental conditions were much better. It was observed that positive questionnaire data and positive skin tests were significantly less frequent in men exposed to PAHs. The men serum IgE values were not statistically different in both group workers although in coke oven workers the tendency to higher IgE values was observed. It is rather suggested that more useful method might be the measurement of specific serum IgE.

  14. Application of random forests method to predict the retention indices of some polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Goudarzi, N; Shahsavani, D; Emadi-Gandaghi, F; Chamjangali, M Arab

    2014-03-14

    In this work, a quantitative structure-retention relationship (QSRR) investigation was carried out based on the new method of random forests (RF) for prediction of the retention indices (RIs) of some polycyclic aromatic hydrocarbon (PAH) compounds. The RIs of these compounds were calculated using the theoretical descriptors generated from their molecular structures. Effects of the important parameters affecting the ability of the RF prediction power such as the number of trees (nt) and the number of randomly selected variables to split each node (m) were investigated. Optimization of these parameters showed that in the point m=70, nt=460, the RF method can give the best results. Also, performance of the RF model was compared with that of the artificial neural network (ANN) and multiple linear regression (MLR) techniques. The results obtained show the relative superiority of the RF method over the MLR and ANN ones.

  15. Characterization of polycyclic aromatic hydrocarbons from the diesel engine by adding light cycle oil to premium diesel fuel.

    Science.gov (United States)

    Lin, Yuan-Chung; Lee, Wen-Jhy; Chen, Chung-Bang

    2006-06-01

    Diesel fuels governed by U.S. regulations are based on the index of the total aromatic contents. Three diesel fuels, containing various fractions of light cycle oil (LCO) and various sulfur, total polyaromatic, and total aromatic contents, were used in a heavy-duty diesel engine (HDDE) under transient cycle test to assess the feasibility of using current indices in managing the emissions of polycyclic aromatic hydrocarbons (PAHs) from HDDE. The mean sulfur content in LCO is 20.8 times as much as that of premium diesel fuel (PDF). The mean total polyaromatic content in LCO is 28.7 times as much as that of PDF, and the mean total aromatic content in LCO is 2.53 times as much as that of PDF. The total polyaromatic hydrocarbon emission factors in the exhaust from the diesel engine, as determined using PDF L3.5 (3.5% LCO and 96.5% PDF), L7.5 (7.5% LCO and 92.5% PDF), and L15 (15% LCO and 85% PDF) were 14.3, 25.8, 44, and 101 mg L(-1), respectively. The total benzo(a)pyrene equivalent (BaPeq) emission factors in the exhaust from PDF, L3.5, L7.5, and L15 were 0.0402, 0.121, 0.219, and 0.548 mg L(-1), respectively. Results indicated that using L3.5 instead of PDF will result in an 80.4% and a 201% increase of emission for total PAHs and total BaPeq, respectively. The relationships between the total polyaromatic hydrocarbon emission factor and the two emission control indices, including fuel polyaromatic content and fuel aromatic content, suggest that both indices could be used feasibly to regulate total PAH emissions. These results strongly suggest that LCO used in the traveling diesel vehicles significantly influences PAH emissions.

  16. 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...

  17. 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...

  18. 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.; Sánchez de Armas, F.; Puerta Saborido, G.; Hudgins, D. M.; Allamandola, L. J.

    2010-01-01

    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 t

  19. 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, bio

  20. Availabiltiy and leaching of polycyclic aromatic hydrocarbons: Controlling processes and comparison of testing methods

    NARCIS (Netherlands)

    Roskam, G.; Comans, R.N.J.

    2009-01-01

    We have studied the availability and leaching of polycyclic aromatic hydrocarbons (PAHs) from two contaminated materials, a tar-containing asphalt granulate (¿16 US-EPA PAHs 3412 mg/kg) and gasworks soil (¿PAHs 900 mg/kg), by comparing results from three typical types of leaching tests: a column, se

  1. POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL

    Science.gov (United States)

    Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

  2. 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...

  3. Novel β-cyclodextrin modified quantum dots as fluorescent probes for polycyclic aromatic hydrocarbons (PAHs)

    Institute of Scientific and Technical Information of China (English)

    Cui Ping Han; Hai Bing Li

    2008-01-01

    Water-soluble CdSe/ZnS quantum dots (QDs)were prepared via a simple sonochemical procedure using β-cyclodextrin (CD)as surface coating agent.The QDs displayed a sensitive emission enhancement for anthracene over other related polycyclic aromatic hydrocarbons,and the detection limit was around 1.6 × 10-8 mol/L.

  4. The effects of polycyclic aromatic hydrocarbons on the chemistry of photodissociation regions

    NARCIS (Netherlands)

    Bakes, ELO; Tielens, AGGM

    1998-01-01

    We have investigated the effects of including polycylic aromatic hydrocarbons (PAHs) on the abundance of neutral atoms and molecules for two typical photodissociation regions (PDRs): a high-density case (the Orion complex) and a low-density case. PAHs provide a large surface area for chemistry betwe

  5. 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.

  6. Polycyclic aromatic hydrocarbons and dust in regions of massive star formation

    NARCIS (Netherlands)

    Peeters, Els

    2002-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are known on earth as a large family of tarry materials naturally present in for example coal and crude oil. In addition, they are also formed in the combustion of all sorts of carbonaceous fuels and hence are found in auto exhaust, cigarette smoke, candle soo

  7. 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…

  8. Development of analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates:A review

    Institute of Scientific and Technical Information of China (English)

    LIU Li-bin; LIU Yan; LIN Jin-ming; TANG Ning; HAYAKAWA Kazuichi; MAEDA Tsuneaki

    2007-01-01

    In the present work,the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.

  9. Empirical modeling of soot formation in shock-tube pyrolysis of aromatic hydrocarbons

    Science.gov (United States)

    Frenklach, M.; Clary, D. W.; Matula, R. A.

    1986-01-01

    A method for empirical modeling of soot formation during shock-tube pyrolysis of aromatic hydrocarbons is developed. The method is demonstrated using data obtained in pyrolysis of argon-diluted mixtures of toluene behind reflected shock waves. The developed model is in good agreement with experiment.

  10. Gas phase adiabatic electron affinities of cyclopenta-fused polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Todorov, P.D.; Koper, C.; van Lenthe, J.H.; Jenneskens, L.W.

    2008-01-01

    The B3LYP/DZP++ adiabatic electron affinity (AEA) of nine (non)-alternant polycyclic aromatic hydrocarbons are reported and discussed. Calculations became feasible for molecules this size by projecting out the near-linearly dependent part of the one-electron basis. Non-alternant PAH consisting of an

  11. Supercooled liquid vapour pressures and related thermodynamic properties of polycyclic aromatic hydrocarbons determined by gas chromatography

    NARCIS (Netherlands)

    Haftka, J.J.H.; Parsons, J.R.; Govers, H.A.J.

    2006-01-01

    A gas chromatographic method using Kovats retention indices has been applied to determine the liquid vapour pressure (P-i), enthalpy of vaporization (Delta H-i) and difference in heat capacity between gas and liquid phase (Delta C-i) for a group of polycyclic aromatic hydrocarbons (PAHs). This group

  12. Production of aromatic hydrocarbons via catalytic pyrolysis of biomass over fe-modified HZSM-5 zeolites

    Science.gov (United States)

    Iron modified HZSM-5 catalysts were prepared by partial ion exchange of NH4ZSM-5 with Fe (II) at three different loadings (1.4, 2.8 and 4.2 wt%), and their effectiveness for producing aromatic hydrocarbons from cellulose, cellobiose, lignin and switchgrass by catalytic pyrolysis were screened using ...

  13. 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...

  14. 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...

  15. 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...

  16. Safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water

    Energy Technology Data Exchange (ETDEWEB)

    Taymaz, K.; Williams, D.T.; Benoit, F.M.

    1979-01-01

    The safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water and industrial wastewaters in the US was studied by observing the reactions of naphthalene and methylnaphthalenes in essentially chlorine-free, aqueous chlorine dioxide solutions. Naphthalene and methylnaphthalenes yielded chlorinated derivatives and oxidation products. Further research is recommended.

  17. Longitudinal study of excretion of metabolites of polycyclic aromatic hydrocarbons in urine from two psoriatic patients

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Menné, T

    1993-01-01

    Coal tar, which is widely used in the treatment of patients with atopic dermatitis, chronic eczema, and psoriasis, contains a large amount of polycyclic aromatic hydrocarbons (PAH). Some of the PAH compounds are known either to be carcinogenic or to potentiate the effects of other carcinogenic su...

  18. 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 P

  19. 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...

  20. Molecular comparison of cultivable protozoa from a pristine and a polycyclic aromatic hydrocarbon polluted site

    DEFF Research Database (Denmark)

    Lara, E; Berney, C; Ekelund, Flemming

    2007-01-01

    We compared the abundance and diversity of cultivable protozoa (flagellates and amoebae) in a polycyclic aromatic hydrocarbon (PAH) polluted soil and an unpolluted control, by isolating and cultivating clonal strains. The number of cultivable protozoa was higher in the polluted soil; however...

  1. 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)

  2. 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 seminatur

  3. Probing the role of polycyclic aromatic hydrocarbons in the photoelectric heating within photodissociation regions

    NARCIS (Netherlands)

    Okada, Y.; Pilleri, P.; Berné, O.; Ossenkopf, V.; Fuente, A.; Goicoechea, J. R.; Joblin, C.; Kramer, C.; Röllig, M.; Teyssier, D.; van der Tak, F. F. S.

    2013-01-01

    Aims: We observationally investigate the relation between the photoelectric heating efficiency in photodissociation regions (PDRs) and the charge of polycyclic aromatic hydrocarbons (PAHs), which are considered to play a key role in photoelectric heating. Methods: Using PACS onboard Herschel, we obs

  4. 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

  5. Non-covalent Interactions of Graphene with Polycyclic Aromatic Hydrocarbons

    NARCIS (Netherlands)

    Zygouri, Panagiota; Potsi, Georgia; Mouzourakis, Eleftherios; Spyrou, Konstantinos; Gournis, Dimitrios; Rudolf, Petra

    2015-01-01

    In this mini review we discuss the interactions of polyaromatic hydrocarbons (PAHs) with graphene and the experimental approaches developed so far to create novel graphene/PAH hybrids and composite systems. The utilization of these systems in electrical, biomedical and polymer-reinforcement applicat

  6. 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 soi

  7. 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......, organic acids, and water) and aliphatic hydrocarbons. We show in this work that the model can be satisfactorily extended to complex vapor-liquid-liquid equilibria with aromatic or olefinic hydrocarbons. The solvation between aromatics/olefinics and polar compounds is accounted for. This is particularly...... 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...

  8. Fingerprints of polycyclic aromatic hydrocarbons (PAHs) in infrared absorption spectroscopy.

    Science.gov (United States)

    Tommasini, Matteo; Lucotti, Andrea; Alfè, Michela; Ciajolo, Anna; Zerbi, Giuseppe

    2016-01-05

    We have analyzed a set of 51 PAHs whose structures have been hypothesized from mass spectrometry data collected on samples extracted from carbon particles of combustion origin. We have obtained relationships between infrared absorption signals in the fingerprint region (mid-IR) and the chemical structures of PAHs, thus proving the potential of IR spectroscopy for the characterization of the molecular structure of aromatic combustion products. The results obtained here for the spectroscopic characterization of PAHs can be also of interest in Materials Science and Astrophysics.

  9. Production of aromatic hydrocarbons by catalytic pyrolysis of microalgae with zeolites: catalyst screening in a pyroprobe.

    Science.gov (United States)

    Du, Zhenyi; Ma, Xiaochen; Li, Yun; Chen, Paul; Liu, Yuhuan; Lin, Xiangyang; Lei, Hanwu; Ruan, Roger

    2013-07-01

    Catalytic pyrolysis of microalgae and egg whites was investigated to evaluate the performance of different zeolites for the production of aromatic hydrocarbons. Three zeolites with different structures (H-Y, H-Beta and H-ZSM5) were used to study the effect of catalyst type on the aromatic yield. All three catalysts significantly increased the aromatic yields from pyrolysis of microalgae and egg whites compared with non-catalytic runs, and H-ZSM5 was most effective with a yield of 18.13%. Three H-ZSM5 with silica-to-alumina ratios of 30, 80 and 280 were used to study the effect of Si/Al ratio on the aromatic yield. The maximum yield was achieved at the Si/Al ratio of 80, which provides moderate acidity to achieve high aromatic production and reduce coke formation simultaneously. Aromatic production increased with the incorporation of copper or gallium to HZSM-5. However, other studied metals either had no significant influence or led to a lower aromatic yield.

  10. Interactions between polycyclic aromatic hydrocarbons in binary mixtures: Effects on gene expression and DNA adduct formation in precision-cut rat liver slices

    NARCIS (Netherlands)

    Staal, Y.C.M.; Pushparajah, D.S.; Herwijnen, M.H.M. van; Gottschalk, R.W.H.; Maas, L.M.; Ioannides, C.; Schooten, F.J. van; Delft, J.H.M. van

    2008-01-01

    Although exposure to polycyclic aromatic hydrocarbons (PAHs) occurs mostly through mixtures, hazard and risk assessment are mostly based on the effects caused by individual compounds. The objective of the current study was to investigate whether interactions between PAHs occur, focusing on gene expr

  11. Use of Physiologically-Based Pharmacokinetic Modeling to Simulate the Profiles of 3-Hydroxybenzo(a)pyrene in Workers Exposed to Polycyclic Aromatic Hydrocarbons

    OpenAIRE

    Roberto Heredia Ortiz; Anne Maître; Damien Barbeau; Michel Lafontaine; Michèle Bouchard

    2014-01-01

    Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models ...

  12. IUPAC-NIST Solubility Data Series. 101. Alcohols + Hydrocarbons + Water Part 3. C1-C3 Alcohols + Aromatic Hydrocarbons

    Science.gov (United States)

    Oracz, Paweł; Góral, Marian; Wiśniewska-Gocłowska, Barbara; Shaw, David G.; Mączyński, Andrzej

    2016-09-01

    The mutual solubilities and related liquid-liquid equilibria for 11 ternary systems of C1-C3 alcohols with aromatic hydrocarbons and water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2012 are compiled. For nine systems, sufficient data are available (two or more independent determinations) to allow critical evaluation. All new data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, an additional criterion was used for each of the evaluated systems. These systems include one binary miscibility gap in the hydrocarbon + water subsystem. The binary tie lines were compared with the recommended values published previously.

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

    Directory of Open Access Journals (Sweden)

    I. HATZIANESTIS

    2012-12-01

    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. The optical spectrum of a large isolated polycyclic aromatic hydrocarbon: hexa-peri-hexabenzocoronene, C42H18

    CERN Document Server

    Kokkin, Damian L; Nakajima, Masakazu; Nauta, Klaas; Varberg, Thomas D; Metha, Gregory F; Lucas, Nigel T; Schmidt, Timothy W

    2008-01-01

    The first optical spectrum of an isolated polycyclic aromatic hydrocarbon large enough to survive the photophysical conditions of the interstellar medium is reported. Vibronic bands of the first electronic transition of the all benzenoid polycyclic aromatic hydrocarbon hexa-peri-hexabenzocoronene were observed in the 4080-4530 Angstrom range by resonant 2-color 2-photon ionization spectroscopy. The strongest feature at 4261 Angstrom is estimated to have an oscillator strength of f=1.4x10^-3, placing an upper limit on the interstellar abundance of this polycyclic aromatic hydrocarbon at 4x10^12 cm^-2, accounting for a maximum of ~0.02% of interstellar carbon. This study opens up the possibility to rigorously test neutral polycyclic aromatic hydrocarbons as carriers of the diffuse interstellar bands in the near future.

  15. 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...

  16. 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 contaminant

  17. On the impact of olefins and aromatics in the methanol-to-hydrocarbon conversion over H-ZSM-5 catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.; Mueller, S.; Veen, A.C. van; Lercher, J.A. [Technische Univ. Muenchen, Garching (Germany). Dept. of Chemistry

    2012-07-01

    Methanol-to-hydrocarbons processes using HZSM-5 archetype acidic zeolites or zeotype SAPO-34 catalysts are regarded as a vital suite of conversion technologies to bypass petroleum-based routes for the production of specific fuels and petrochemical commodities. Special significance of the methanol chemistry originates from its versatility enabling selective transformations towards various products. Industry demonstrated successfully implementations of Methanol-To-Gasoline, Methanol-To-Olefin, and Methanol-To-Propylene processes, although the typical single-pass selectivity remained limited and recycling is necessary. Considerable fundamental research efforts both from experimental and computational sides contributed to unravel the underlying complex reaction mechanism. The indirect hydrocarbon pool mechanism, in which Broensted acid sites combined with adsorbed light olefins or lower methylbenzenes act as active centers, is generally accepted to explain the formation of light olefins. As olefin and aromatics populated catalytic sites show different reactivity in terms of activity and selectivity to ethylene or propylene, one could envision optimizing the product distribution by suitable co-feeding of specific hydrocarbons. The present work addresses three questions with an experimental study conducted under realistic MTP operation conditions: (1) How are ethylene and propylene formed at molecular level? (2) Which reaction pathway leads to the formation of undesired hydrogen transfer products? (3) Does olefin or aromatics co-feeding change the selectivity to ethylene or propylene? Xylenes and various olefins were co-fed with methanol to achieve a detailed understanding of the reaction mechanism over acidic HZSM-5 zeolites. Results suggest, that an olefin homologation/cracking route (olefin cycle) accounts for the autocatalytic (-like) nature and the majority of methanol consumption rather than the route involving aromatic intermediates (aromatics cycle). Co

  18. Degradation of polycyclic aromatic hydrocarbons in the presence of synthetic surfactants.

    OpenAIRE

    Tiehm, A

    1994-01-01

    The biodegradation of polycyclic aromatic hydrocarbons (PAH) often is limited by low water solubility and dissolution rate. Nonionic surfactants and sodium dodecyl sulfate increased the concentration of PAH in the water phase because of solubilization. The degradation of PAH was inhibited by sodium dodecyl sulfate because this surfactant was preferred as a growth substrate. Growth of mixed cultures with phenanthrene and fluoranthene solubilized by a nonionic surfactant prior to inoculation wa...

  19. Effect of low concentrations of synthetic surfactants on polycyclic aromatic hydrocarbons (PAH) biodegradation

    OpenAIRE

    A. C. Rodrigues; Nogueira, R; Melo, L. F.; A. G. Brito

    2013-01-01

    The present study is focused on the effect of synthetic surfactants, at low concentration, on the kinetics of polycyclic aromatic hydrocarbons (PAH) biodegradation by Pseudomonas putida ATCC 17514 and addresses the specific issue of the effect of the surfactant on bacterial adhesion to PAH, which is believed to be an important mechanism for the uptake of hydrophobic compounds. For that purpose, three surfactants were tested, namely, the nonionic Tween 20, the anionic sodium dodecyl sulphate (...

  20. Advances in the field of high‐molecular‐weight polycyclic aromatic hydrocarbon biodegradation by bacteria

    OpenAIRE

    Kanaly, Robert A.; Harayama, Shigeaki

    2010-01-01

    Summary Interest in understanding prokaryotic biotransformation of high‐molecular‐weight polycyclic aromatic hydrocarbons (HMW PAHs) has continued to grow and the scientific literature shows that studies in this field are originating from research groups from many different locations throughout the world. In the last 10 years, research in regard to HMW PAH biodegradation by bacteria has been further advanced through the documentation of new isolates that represent diverse bacterial types that...

  1. Use of Ionic Liquid-filled Semipermeable Membrane for Extraction of Polycyclic Aromatic Hydrocarbons in Water

    Institute of Scientific and Technical Information of China (English)

    Wen Yan ZHAO; Meng HAN; Shu Gui DAI; Xia ZHONG

    2005-01-01

    A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM] [PF6]) - filled semipermeable membrane. For24 hrs extraction of naphthalene, 1-methylnaphthalene, 2-chloronaphthalene, phenanthrene, the result showed that the extraction efficiency, correlation coefficient (R2) and RSD (n=5) were in the range of 67-102 %, 0.9870-0.9962, and 2.1-5.3 %, respectively.

  2. 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...

  3. Prenatal exposure to polycyclic aromatic hydrocarbons and cognitive dysfunction in children

    OpenAIRE

    Jedrychowski, Wiesław A.; Perera, Frederica P.; Camann, David; Spengler, John; Butscher, Maria; Mroz, Elzbieta; Majewska, Renata; Flak, Elżbieta; Jacek, Ryszard; Sowa, Agata

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced by combustion of fossil fuel and other organic materials. Both experimental animal and human studies have reported the harmful impacts of PAH compounds on fetal growth and neurodevelopment, including verbal IQ of children. Here, we have assessed the association between cognitive function of children and prenatal PAH exposures. The study is part of an ongoing, longitudinal investigation of the health effec...

  4. Molecular cloning of novel genes for polycyclic aromatic hydrocarbon degradation from Comamonas testosteroni GZ39.

    OpenAIRE

    1996-01-01

    Three strains of Comamonas testosteroni were isolated from river sediment for the ability to degrade phenanthrene; two of the strains also grew on naphthalene, and one strain also grew on anthracene. The homology of the genes for polycyclic aromatic hydrocarbon degradation in these strains to the classical genes (nah) for naphthalene degradation from Pseudomonas putida NCIB 9816-4 was determined. The three C. testosteroni strains showed no homology to the nah gene probe even under low-stringe...

  5. Estimated IR and phosphorescence emission fluxes for specific Polycyclic Aromatic Hydrocarbons in the Red Rectangle

    CERN Document Server

    Mulas, G; Joblin, C; Toublanc, D

    2005-01-01

    Following the tentative identification of the blue luminescence in the Red Rectangle by Vijh et al. (2005), we compute absolute fluxes for the vibrational IR emission and phosphorescence bands of three small polycyclic aromatic hydrocarbons. The calculated IR spectra are compared with available ISO observations. A subset of the emission bands are predicted to be observable using presently available facilities, and can be used for an immediate, independent, discriminating test on their alleged presence in this well-known astronomical object.

  6. Structural Vector Description and Estimation of Normal Boiling Points for 66 Aromatic Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A molecular vector-type descriptor containing 6 variables is used to describe the structure of aromatic hydrocarbons (AHs) and relate to normal boiling points (bp) of AHs. The correlation coefficient (R) between the estimated bp and experimental bp is 0.9988 and the root mean square error (RMS) is 7.907° C for 66 AHs. The RMS obtained by cross-validation is 9.131° C, which implies the relationship model having good prediction ability.

  7. Analysis of 23 polycyclic aromatic hydrocarbons in smokeless tobacco by gas chromatography-mass spectrometry

    OpenAIRE

    Stepanov, Irina; Villalta, Peter W.; Knezevich, Aleksandar; Jensen, Joni; Hatsukami, Dorothy; Hecht, Stephen S.

    2010-01-01

    Smokeless tobacco contains 28 known carcinogens and causes precancerous oral lesions and oral and pancreatic cancer. A recent study conducted by our research team identified 8 different polycyclic aromatic hydrocarbons (PAH) in U.S. moist snuff, encouraging further investigations of this group of toxicants and carcinogens in smokeless tobacco products. In this study, we developed a gas chromatography-mass spectrometry method that allows simultaneous analysis of 23 various PAH in smokeless tob...

  8. Fingerprint of polycyclic aromatic hydrocarbons in two populations of southern sea lions (Otaria flavescens).

    Science.gov (United States)

    Marsili, L; Fossi, M C; Casini, S; Savelli, C; Jimenez, B; Junin, M; Castello, H

    1997-02-01

    The fingerprint of 14 polycyclic aromatic hydrocarbons (PAHs) was investigated in biopsy, fur, blood, liver and faeces of live and dead specimens of two Argentinian population of southern sea lion (Otaria flavescens). One colony lives in Mar del Plata harbour which is particularly polluted with petroleum, the second (control) colony lives at Punta Bermeja (Patagonia). The highest concentrations of the five carcinogenic PAHs were found in the Mar del Plata sea lions.

  9. Detection and characterization of human serum antibodies to polycyclic aromatic hydrocarbon diol-epoxide DNA adducts.

    OpenAIRE

    Newman, M J; Light, B A; Weston, A; Tollurud, D; Clark, J L; Mann, D L; Blackmon, J P; Harris, C C

    1988-01-01

    The presence of serum antibodies to the diol-epoxide DNA adducts of representative polycyclic aromatic hydrocarbons (PAH), chrysene, benz[a]anthracene and benzo[a]pyrene, was determined by ELISA using serum samples obtained from normal healthy individuals. Antibodies that reacted against PAH adducted-DNA, but not against PAH-adducted protein, were found in the serum of approximately 40% of the test individuals. Specificity analysis of the antibodies demonstrated that serological cross-reactio...

  10. Calculation of electron affinities of polycyclic aromatic hydrocarbons and solvation energies of their radical anion.

    Science.gov (United States)

    Betowski, Leon D; Enlow, Mark; Riddick, Lee; Aue, Donald H

    2006-11-30

    Electron affinities (EAs) and free energies for electron attachment (DeltaGo(a,298K)) have been directly calculated for 45 polynuclear aromatic hydrocarbons (PAHs) and related molecules by a variety of theoretical methods, with standard regression errors of about 0.07 eV (mean unsigned error = 0.05 eV) at the B3LYP/6-31 + G(d,p) level and larger errors with HF or MP2 methods or using Koopmans' Theorem. Comparison of gas-phase free energies with solution-phase reduction potentials provides a measure of solvation energy differences between the radical anion and neutral PAH. A simple Born-charging model approximates the solvation effects on the radical anions, leading to a good correlation with experimental solvation energy differences. This is used to estimate unknown or questionable EAs from reduction potentials. Two independent methods are used to predict DeltaGo(a,298K) values: (1) based upon DFT methods, or (2) based upon reduction potentials and the Born model. They suggest reassignments or a resolution of conflicting experimental EAs for nearly one-half (17 of 38) of the PAH molecules for which experimental EAs have been reported. For the antiaromatic molecules, 1,3,5-tri-tert-butylpentalene and the dithia-substituted cyclobutadiene 1, the reduction potentials lead to estimated EAs close to those expected from DFT calculations and provide a basis for the prediction of the EAs and reduction potentials of pentalene and cyclobutadiene. The Born model has been used to relate the electrostatic solvation energies of PAH and hydrocarbon radical anions, and spherical halide anions, alkali metal cations, and ammonium ions to effective ionic radii from DFT electron-density envelopes. The Born model used for PAHs has been successfully extended here to quantitatively explain the solvation energy of the C60 radical anion.

  11. Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons.

    Science.gov (United States)

    Frenzel, Max; Scarlett, Alan; Rowland, Steven J; Galloway, Tamara S; Burton, Sara K; Lappin-Scott, Hilary M; Booth, Andy M

    2010-09-01

    Environmentally persistent aromatic hydrocarbons known as unresolved complex mixtures (UCMs) derived from crude oil can be accumulated by, and elicit toxicological responses in, marine organisms (e.g. mussels, Mytilus edulis). Comprehensive two-dimensional gas chromatography time-of-flight mass-spectrometry (GCxGC-ToF-MS) previously revealed that these UCMs included highly branched alkylated aromatic hydrocarbons. Here, the effects of biodegradation on the toxicity and chemical composition of an aromatic UCM hydrocarbon fraction isolated from Tia Juana Pesado (TJP) crude oil were examined. 48h exposure of mussels to the aromatic hydrocarbon fraction (F2) resulted in tissue concentrations of 900microgg(-1) (dry wt.) and approximately 45% decrease in clearance rate. Over 90% of the hydrocarbon burden corresponded to an UCM. Following a 5day recovery period, GCxGC-ToF-MS analysis of the tissues indicated depuration of most accumulated hydrocarbons and clearance rates returned to those observed in controls. To assess the potential of biodegradation to reduce UCM toxicity, TJP F2 was exposed to bacteria isolated from Whitley Bay, UK, for 46days. Mussels exposed to the undegraded TJP F2 from the abiotic control exhibited a reduction in clearance rate comparable with values for the pure crude oil TJP F2. Clearance rates of mussels exposed to biodegraded TJP F2 were statistically similar to seawater controls, suggesting biodegradation had reduced the TJP F2 toxicity. GCxGC-ToF-MS analysis revealed the same compound groups in the tissue of mussels exposed to pure TJP F2, undegraded TJP F2 and biodegraded TJP F2 samples; however >300 fewer compounds were observed in the biodegraded (954 compounds) compared to the undegraded TJP F2 (1261). The compound distributions were markedly different, possibly accounting for the decrease in toxicity. Extraction and analysis of pelleted bacterial cell material revealed that a significant proportion of the TJP F2 had adsorbed onto the

  12. Assessment of the bioavailability and phytotoxicity of sediment spiked with polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Rončević, Srđan; Spasojević, Jelena; Maletić, Snežana; Jazić, Jelena Molnar; Isakovski, Marijana Kragulj; Agbaba, Jasmina; Grgić, Marko; Dalmacija, Božo

    2016-02-01

    Large amounts of sediment are dredged globally every year. This sediment is often contaminated with low concentrations of metals, polycyclic aromatic hydrocarbons, pesticides and other organic pollutants. Some of this sediment is disposed of on land, creating a need for risk assessment of the sediment disposal method, to minimize the degradation of environmental quality and prevent risks to human health. Evaluating the available fractions of certain polycyclic aromatic hydrocarbons is very important, as in the presence of various organisms, they are believed to be easily subject to the processes of bioaccumulation, biosorption and transformation. In order to determine the applicability of applying these methods for the evaluation of pollutant bioavailability in sediments, the desorption kinetics from the sediment of various polycyclic aromatic hydrocarbons in the presence of Tenax and XAD4 were examined over the course of 216 h. Changes in the PAH concentrations in dredged sediments using five different seed plants during a short time of period (10 days) were also followed. Using chemical extraction techniques with Tenax and XAD4, a time of around 24 h is enough to achieve equilibrium for all four PAHs. Results showed good agreement between the seed accumulation and PAH extraction methods with both agents. If we compare the two extraction techniques, XAD4 gave better results for phenanthrene, pyrene and benzo(a)pyrene, and Tenax gave better results for chrysene.

  13. 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.

  14. 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.

  15. A method for removing aromatic hydrocarbons from liquid n-paraffins

    Energy Technology Data Exchange (ETDEWEB)

    Gayle, A.A.; Pavlyuk, N.F.; Proskuryakov, V.A.; Semenov, L.V.; Zakhrov, A.P.

    1982-01-01

    In the known method for removing aromatic hydrocarbons from liquid n-paraffins through liquid extraction by a selective solvent, in order to increase the output of the paraffins methoxyacetonitrile (I) is used as the selective solvent. The advantages of the extraction process using I are high output and quality of the purified paraffins and the possibility of using series produced extractors of medium effectiveness. The high selectivity of I relative to aromatic hydrocarbons, unlike low selective acetone in the known method and its high density (1.032) as compared with acetone (0.790) provide for effective mass exchange in industrial performance of the process. The regeneration of I from the extraction phase may be accomplished through rectification. In an example of single stage isolation of mixtures of n-tetradecane with 1,2,4,5-tetramethylbenzene and 1-methylnaphthaline (a temperature of 30 degrees, a ratio of solvent to raw material of 3, an aromatic hydrocarbon content in the mixture of 1.0 percent) showed the following.

  16. Infrared spectra of protonated polycyclic aromatic hydrocarbon molecules: Azulene

    Science.gov (United States)

    Zhao, Dawei; Langer, Judith; Oomens, Jos; Dopfer, Otto

    2009-11-01

    The infrared (IR) spectrum of protonated azulene (AzuH+, C10H9+) has been measured in the fingerprint range (600-1800 cm-1) by means of IR multiple photon dissociation (IRMPD) spectroscopy in a Fourier transform ion cyclotron resonance mass spectrometer equipped with an electrospray ionization source using a free electron laser. The potential energy surface of AzuH+ has been characterized at the B3LYP/6-311G∗∗ level in order to determine the global and local minima and the corresponding transition states for interconversion. The energies of the local and global minima, the dissociation energies for the lowest-energy fragmentation pathways, and the proton affinity have been evaluated at the CBS-QB3 level. Comparison with calculated linear IR absorption spectra supports the assignment of the IRMPD spectrum to C4-protonated AzuH+, the most stable of the six distinguishable C-protonated AzuH+ isomers. Comparison between Azu and C4-AzuH+ reveals the effects of protonation on the geometry, vibrational properties, and the charge distribution of these fundamental aromatic molecules. Calculations at the MP2 level indicate that this technique is not suitable to predict reliable IR spectra for this type of carbocations even for relatively large basis sets. The IRMPD spectrum of protonated azulene is compared to that of isomeric protonated naphthalene and to an astronomical spectrum of the unidentified IR emission bands.

  17. DISTRIBUTION AND CHARACTERIZATION OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN AIRBORNE PARTICULATES OF EAST ASIA

    Institute of Scientific and Technical Information of China (English)

    Yan Liu; Libin Liu; Jin-Ming Lin; Ning Tang; Kazuichi Hayakawa

    2006-01-01

    A review is presented on the distribution and characterization of polycyclic aromatic hydrocarbons (PAHs)and their derivatives, including nitro-PAHs and hydro-PAHs, on atmospheric particulates of East Asia. Generally, PAH compounds with two or three aromatic rings are released mainly into the gas phase, while those containing three or more aromatic rings are associated with particulate matter (PM) emission. Particle-associated PAHs are primarily adsorbed on fine particles, and little associated with coarse particles. Investigation into the concentration level of PAHs in different areas can serve not only to reflect the pollutant status and sources but also to lead to the formulation of control strategies.The results of the present study show that China has more severe PAH pollution than such East Asian countries as Japan and Korea.

  18. Aliphatic and aromatic hydrocarbons in particulate fallout of Alexandria, Egypt: Sources and implications

    Energy Technology Data Exchange (ETDEWEB)

    Aboul-Kassim, T.A.T.; Simoneit, B.R.T. [Oregon State Univ., Corvallis, OR (United States)

    1995-10-01

    Particulate fallout samples (PFS) were collected in Alexandria, and their aliphatic and aromatic hydrocarbon compositions were determined both quantitatively and qualitatively to characterize the homologous and biomarker compounds in terms of their original sources. The results show that all samples contain aliphatic hydrocarbons, including n-alkanes, UCM, isoprenoids, tri- and tetracyclic terpanes, hopanes, and steranes/diasteranes. The main source of these compounds is from petrochemical contamination with trace input of terrestrial higher plant wax. In addition, polycyclic aromatic hydrocarbons, which are considered to be combustion products from fossil fuels such as petroleum, are also widely distributed in all samples. Multivariate statistical analysis, including extended Q-mode factor analysis and linear programming technique, was performed in order to reduce the hydrocarbon data set into a meaningful number of end members (sources). This analysis indicates that there are two significant end members explaining 90% of the total variation among the samples and confirming petrochemical (79.6%), and thermogenic/pyrolytic (10.4%) sources in the PFS model. 65 refs., 7 figs., 4 tabs.

  19. Risk assessment of urban soils contamination: The particular case of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

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

    2016-05-01

    The assessment of soil quality and characterization of potential risks to the environment and human health can be a very difficult task due to the heterogeneity and complexity of the matrix, the poor understanding about the fate of contaminants in the soil matrix, scarcity of toxicological/ecotoxicological data and variability of guidelines. In urban soils these difficulties are enhanced by the patchy nature of urban areas and the presence of complex mixtures of organic and inorganic contaminants resulting from diffuse pollution caused by urban activities (e.g. traffic, industrial activity, and burning of carbon sources for heating). Yet, several tools are available which may help to assess the risks of soil contamination in a simpler, cost effective and reliable way. Within these tools, a tiered risk assessment (RA) approach, first based on a chemical screening in combination with geostatistical tools, may be very useful in urban areas. However, there is still much to improve and a long way to go in order to obtain a reliable RA, especially in the case of hydrophobic organic compounds such as polycyclic aromatic hydrocarbons (PAHs). This paper aims at proposing a RA framework to assess the environmental and human health risks of PAHs present in urban soils, based on existing models. In addition, a review on ecotoxicological, toxicological, and exposure assessment data was made, as well as of the existing soil quality guidelines for PAHs that can be used in the RA process.

  20. 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.

  1. Prediction of mono- and polycyclic aromatic hydrocarbon degradation in spiked soils using cyclodextrin extraction

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Ian J. [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Semple, Kirk T. [Department of Environmental Sciences, Lancaster University, LA1 4YQ (United Kingdom); Hare, Rina [Alcontrol Laboratories, Chester CH5 3US (United Kingdom); Reid, Brian J. [Alcontrol Laboratories, Chester CH5 3US (United Kingdom)]. E-mail: b.reid@uea.ac.uk

    2006-11-15

    In this study, an aqueous-based hydroxypropyl-{beta}-cyclodextrin (HPCD) extraction technique was assessed for its capacity to determine the microbially degradable fraction of mono- and polycyclic aromatic hydrocarbons in four dissimilar soils. A linear relationship (slope = 0.90; R {sup 2} = 0.89), approaching 1:1 between predicted and observed phenanthrene mineralization, was demonstrated for the cyclodextrin extraction; however, the water only extraction underestimated the microbially available fraction by a factor of three (slope = 3.35; R {sup 2} = 0.64). With respect to determining the mineralizable fraction of p-cresol in soils, the cyclodextrin extraction (slope = 0.94; R {sup 2} = 0.84) was more appropriate than the water extraction (slope = 1.50; R {sup 2} = 0.36). Collectively, these results suggested that the cyclodextrin extraction technique was suitable for the prediction of the mineralizable fraction of representative PAHs and phenols present in dissimilar soils following increasing soil-contaminant contact times. The assessment of the microbial availability of contaminants in soils is important for a more representative evaluation of soil contamination. - An aqueous-based HPCD extraction technique was more appropriate than the water extraction in prediction of the mineralizable fraction of phenanthrene and p-cresol present in a range of dissimilar soils.

  2. Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

    Science.gov (United States)

    Yao, Yao; Meng, Xiang-Zhou; Wu, Chen-Chou; Bao, Lian-Jun; Wang, Feng; Wu, Feng-Chang; Zeng, Eddy Y

    2016-06-01

    Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe. The composition profiles of PAHs indicated that PAHs in the inland lakes were derived mainly from local oil spills, which was corroborated by a large number of fuel spillage reports from ship and plane crash incidents in Antarctica during recent years. Clearly, local human activities, rather than long-range transport, are the dominant sources of PAH contamination to the inland lakes. Finally, the present study demonstrates the efficacy of PE-based passive samplers for investigating PAHs in the aquatic environment of Antarctica under complex field conditions.

  3. Comparison of monolithic capillary electrochromatography and micellar electrokinetic chromatography for the separation of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Salwiński, Aleksander; Delépée, Raphaël

    2014-05-01

    Atmospheric pollution of anthropic origin is recognized as a major risk factor for health, in particular for respiratory and cardio-vascular systems. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs) are placed on the list of US Environmental Protection Agency (EPA) as 'priority' pollutants and four of them are assigned as potential carcinogens by The International Agency for Research on Cancer (IARC). In the present work two capillary techniques-micellar electrokinetic chromatography (MEKC) and monolithic capillary electrochromatography (CEC)-were compared for the separation of eleven PAHs. Both techniques compared in the present work are fully compatible with every standard apparatus of capillary electrophoresis. For MEKC, enhancement of selectivity and decrease of the separation window of eleven PAHs were obtained with methanol:borate 25 mM (20/80, v/v) running buffer containing 10 mM of hydroxypropylated γ-cyclodextrins with low SDS content (25 mM). In case of CEC, two acrylate-based monolithic stationary phases (MSPs) were evaluated for their application in the separation of eleven PAHs. The best MSP based on butyl acrylate was compared with MEKC in terms of sample capacity, PAHs elution order, LOQ, efficiency and effect of pH. Influence of the hydrophobicity of mobile phase on the PAHs elution order was also studied.

  4. Asymmetric polycyclic aromatic hydrocarbon as a capable source of astronomically observed interstellar infrared spectrum

    CERN Document Server

    Ota, Norio

    2015-01-01

    In order to find out capable molecular source of astronomically well observed infrared (IR) spectrum, asymmetric molecular configuration polycyclic aromatic hydrocarbon (PAH) was analyzed by the density functional theory (DFT) analysis. Starting molecules were benzene C6H6, naphthalene C10H8 and 1H-phenalene C13H9. In interstellar space, those molecules will be attacked by high energy photon and proton, which may bring cationic molecules as like C6H6n+ (n=0~3 in calculation), C10H8n+, and C13H9n+, also CH lacked molecules C5H5n+, C9H7n+, and C12H8n+. IR spectra of those molecules were analyzed based on DFT based Gaussian program. Results suggested that symmetrical configuration molecules as like benzene, naphthalene , 1H-phenalene and those cation ( +, 2+, and 3+) show little resemblance with observed IR. Contrast to such symmetrical molecules, several cases among cationic and asymmetric configuration molecules show fairly good IR tendency. One typical example was C12H83+, of which calculated harmonic IR wave...

  5. Structurally Distinct Polycyclic Aromatic Hydrocarbons Induce Differential Transcriptional Responses in Developing Zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Goodale, Britton; Tilton, Susan C.; Corvi, Margaret M.; Wilson, Glenn V.; Janszen, Derek B.; Anderson, Kim A.; Waters, Katrina M.; Tanguay, Robert

    2013-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment as components of fossil fuels and by-products of combustion. These multi-ring chemicals differentially activate the aryl hydrocarbon receptor (AHR) in a structurally dependent manner, and induce toxicity via both AHR-dependent and -independent mechanisms. PAH exposure is known to induce developmental malformations in zebrafish embryos, and recent studies have shown cardiac toxicity induced by compounds with low AHR affinity. Unraveling the potentially diverse molecular mechanisms of PAH toxicity is essential for understanding the hazard posed by complex PAH mixtures present in the environment. We analyzed transcriptional responses to PAH exposure in zebrafish embryos exposed to benz(a)anthracene (BAA), dibenzothiophene (DBT) and pyrene (PYR) at concentrations that induced developmental malformations by 120 h post-fertilization (hpf). Whole genome microarray analysis of mRNA expression at 24 and 48 hpf identified genes that were differentially regulated over time and in response to the three PAH structures. PAH body burdens were analyzed at both time points using GC-MS, and demonstrated differences in PAH uptake into the embryos. This was important for discerning dose-related differences from those that represented unique molecular mechanisms. While BAA misregulated the least number of transcripts, it caused strong induction of cyp1a and other genes known to be downstream of the AHR, which were not induced by the other two PAHs. Analysis of functional roles of misregulated genes and their predicted regulatory transcription factors also distinguished the BAA response from regulatory networks disrupted by DBT and PYR exposure. These results indicate that systems approaches can be used to classify the toxicity of PAHs based on the networks perturbed following exposure, and may provide a path for unraveling the toxicity of complex PAH mixtures.

  6. Potential of non-ligninolytic fungi in bioremediation of chlorinated and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Marco-Urrea, Ernest; García-Romera, Inmaculada; Aranda, Elisabet

    2015-12-25

    In previous decades, white-rot fungi as bioremediation agents have been the subjects of scientific research due to the potential use of their unspecific oxidative enzymes. However, some non-white-rot fungi, mainly belonging to the Ascomycota and Zygomycota phylum, have demonstrated their potential in the enzymatic transformation of environmental pollutants, thus overcoming some of the limitations observed in white-rot fungi with respect to growth in neutral pH, resistance to adverse conditions and the capacity to surpass autochthonous microorganisms. Despite their presence in so many soil and water environments, little information exists on the enzymatic mechanisms and degradation pathways involved in the transformation of hydrocarbons by these fungi. This review describes the bioremediation potential of non-ligninolytic fungi with respect to chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) and also shows known conversion pathways and the prospects for future research.

  7. 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

  8. Inorganic-organic hybrid coating material for the online in-tube solid-phase microextraction of monohydroxy polycyclic aromatic hydrocarbons in urine.

    Science.gov (United States)

    Wang, ShuLing; Xu, Hui

    2016-12-01

    An inorganic-organic hybrid nanocomposite (zinc oxide/polypyrrole) that represents a novel kind of coating for in-tube solid-phase microextraction is reported. The composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless-steel tube. Based on the coated tube, a novel online in-tube solid-phase microextraction with liquid chromatography and mass spectrometry method was developed and applied for the extraction of three monohydroxy polycyclic aromatic hydrocarbons in human urine. The coating displayed good extraction ability toward monohydroxy polycyclic aromatic hydrocarbons. In addition, long lifespan, excellent stability, and good compression resistance were also obtained for the coating. The experimental conditions affecting the extraction were optimized systematically. Under the optimal conditions, the limits of detection and quantification were in the range of 0.039-0.050 and 0.130-0.167 ng/mL, respectively. Good linearity (0.2-100 ng/mL) was obtained with correlation coefficients larger than 0.9967. The repeatability, expressed as relative standard deviation, ranged between 2.5% and 9.4%. The method offered the advantage of process simplicity, rapidity, automation, and sensitivity in the analysis of human urinary monohydroxy polycyclic aromatic hydrocarbons in two different cities of Hubei province. An acceptable recovery of monohydroxy polycyclic aromatic hydrocarbons (64-122%) represented the additional attractive features of the method in real urine analysis.

  9. 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

  10. QSAR for Predicting Biodegradation Rates of Polycyclic Aromatic Hydrocarbons in Aqueous Systems

    Institute of Scientific and Technical Information of China (English)

    XU Xiang; LI Xian-Guo

    2012-01-01

    The relationship between chemical structures and biodegradation rates (k b) of 22 polycyclic aromatic hydrocarbons (PAHs) was studied using density functional theory (DFT) and stepwise multiple linear regression analysis (SMLR) method.The equilibrium geometries and vibration frequency have been investigated at the B3LYP/6-31+G(d,p) level by thinking Solvent effects using a selfconsistent reaction field (SCRF) based on the polarizable continuum model (PCM).It was concluded that the biodegradation rate was closely related to its molecular structure,and there is one high correlation coefficient between the in-plane bending vibration frequency of the conjugated ring of PAHs (Freq) and k b.By means of regression analysis,the main factors affecting the biodegradation rate were obtained and the equation of quantitative structure-activity relationship (QSAR) was successfully established kb =-0.653+0.001Freq+0.068CQ+0.049N1.Statistical evaluation of the developed QSAR showed that the relationships were statistically significant and the model had good predictive ability.The fact that a bending frequency is more important than the HOMO or LUMO energies in predicting k b suggests that the bending of benzene ring might play an important role in the enzymatic catalysis of the initial oxidation step.

  11. Isolation and characterization of heavy polycyclic aromatic hydrocarbon-degrading bacteria adapted to electrokinetic conditions.

    Science.gov (United States)

    Li, Fengmei; Guo, Shuhai; Hartog, Niels; Yuan, Ye; Yang, Xuelian

    2016-02-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in artificially contaminated soils. The results showed that strains PB4 (Pseudomonas fluorescens) and FB6 (Kocuria sp.) were the most efficient heavy PAH degraders under electrokinetic conditions. They were re-inoculated into a polluted soil from an industrial site with a PAH concentration of 184.95 mg kg(-1). Compared to the experiments without an electric field, the degradation capability of Pseudomonas fluorescens and Kocuria sp. was enhanced in the industrially polluted soil under electrokinetic conditions. The degradation extents of total PAHs were increased by 15.4 and 14.0% in the electrokinetic PB4 and FB6 experiments (PB4 + EK and FB6 + EK) relative to the PB4 and FB6 experiments without electrokinetic conditions (PB4 and FB6), respectively. These results indicated that P. fluorescens and Kocuria sp. could efficiently degrade heavy PAHs under electrokinetic conditions and have the potential to be used for the electro-bioremediation of PAH-contaminated soil, especially if the soil is contaminated with heavy PAHs.

  12. Differential immunomodulatory responses to nine polycyclic aromatic hydrocarbons applied by passive dosing.

    Science.gov (United States)

    Oostingh, Gertie J; Smith, Kilian E C; Tischler, Ulrike; Radauer-Preiml, Isabella; Mayer, Philipp

    2015-03-01

    Studying the effects of hydrophobic chemicals using in vitro cell based methods is hindered by the difficulty in bringing and keeping these chemicals in solution. Their effective concentrations are often lower than their nominal concentrations. Passive dosing is one approach that provides defined 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 cytokine 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(a)antracene and benzo(a)pyrene. Cytokine promoter expression was then studied in dose response experiments with acenaphthene, phenanthrene and benzo(a)anthracene. The strongest induction was observed for benzo(a)anthracene. Cell viability analysis was performed and showed that none of the PAHs induced cytotoxicity 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 and decreased then with concentration despite the apparent absence of cytotoxicity.

  13. Global atmospheric emissions and transport of polycyclic aromatic hydrocarbons: Evaluation of modeling and transboundary pollution

    Science.gov (United States)

    Shen, Huizhong; Tao, Shu

    2014-05-01

    Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimated country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1° × 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). MOZART-4 (The Model for Ozone and Related Chemical Tracers, version 4) was applied to simulate the global tropospheric transport of Benzo(a)pyrene, one of the high molecular weight carcinogenic PAHs, at a horizontal resolution of 1.875° (longitude) × 1.8947° (latitude). The reaction with OH radical, gas/particle partitioning, wet deposition, dry deposition, and dynamic soil/ocean-air exchange of PAHs were considered. The simulation was validated by observations at both background and non-background sites, including Alert site in Canadian High Arctic, EMEP sites in Europe, and other 254 urban/rural sites reported from literatures. Key factors effecting long-range transport of BaP were addressed, and transboundary pollution was discussed.

  14. Screening method for the analysis of polycyclic aromatic hydrocarbons by high performance thin layer chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Butler, H.T.

    1983-01-01

    Investigations were carried out to develop a routine analytical method for the determination of the polycyclic aromatic hydrocarbons (PAH) in environmental samples. The method used high performance thin layer chromatography (HPTLC) for the separation of the PAH's. Densitometric measurements using selective fluorescence detection was employed for the quantitative aspects of the method. High performance silica gel, cellulose, acetylated cellulose and reversed-phase plates as the separation media were evaluated. Reversed-phase plates with 60% silanization and solvent system of methanol:water using continuous multiple developments produced the best separation. The method was evaluated using shale oil, air particulate, diesel exhaust particulate and an in-house dust samples. During the course of the studies a characterization of the fluorescence and single wavelength double beam reflectance modes was performed. Based on observations made during the characterization studies, a calibration method employing a single standard solution was developed. The method had an operating range of approximately 0.5 to 20 ng and is suitable as a scouting technique to determine approximate concentrations of unknown samples in HPTLC. A method for expressing the relative fluorescence intensity of the PAH's at a given excitation wavelength was also developed. The emission response ratios (ERR) were useful in approximating interferences and determining optimal wavelength combinations.

  15. Evaluating the biodegradation of aromatic hydrocarbons by monitoring of several functional genes.

    Science.gov (United States)

    Piskonen, Reetta; Nyyssönen, Mari; Itävaara, Merja

    2008-11-01

    Various microbial activities determine the effectiveness of bioremediation processes. In this work, we evaluated the feasibility of gene array hybridization for monitoring the efficiency of biodegradation processes. Biodegradation of 14C-labelled naphthalene and toluene by the aromatic hydrocarbon-degrading Pseudomonas putida F1, P. putida mt-2 and P. putida G7 was followed in mixed liquid culture microcosm by a preliminary, nylon membrane-based gene array. In the beginning of the study, toluene was degraded rapidly and increased amount of toluene degradation genes was detected by the preliminary gene array developed for the study. After toluene was degraded, naphthalene mineralization started and the amount of naphthalene degradation genes increased as biodegradation proceeded. The amount of toluene degradation genes decreased towards the end of the study. The hybridization signal intensities determined by preliminary gene array were in good agreement with mineralization of naphthalene and toluene and with the amount of naphthalene dioxygenase and toluene dioxygenase genes quantified by dot blot hybridization. The clear correlation between the results obtained by the preliminary array and the biodegradation process suggests that gene array methods can be considered as a promising tool for monitoring the efficiency of biodegradation processes.

  16. Use of SPMDs to determine average water concentration of polycyclic aromatic hydrocarbons in urban stormwater runoff

    Energy Technology Data Exchange (ETDEWEB)

    DeVita, W.; Crunkilton, R. [Univ. of Wisconsin, Stevens Point, WI (United States)

    1995-12-31

    Semipermeable polymeric membrane devices (SPMDS) were deployed for 30 day periods to monitor polycyclic aromatic hydrocarbons (PAHs) in an urban stream which receives much of its flow from urban runoff. SPMDs are capable of effectively sampling several liters of water per day for some PAHs. Unlike conventional methods, SPMDs sample only those non-polar organic contaminants which are truly dissolved and available for bioconcentration. Also, SPMDs may concentrate contaminants from episodic events such as stormwater discharge. The State of Wisconsin has established surface water quality criteria based upon human lifetime cancer risk of 23 ppt for benzo(a)pyrene and 23 ppt as the sum of nine other potentially carcinogenic PAHs. Bulk water samples analyzed by conventional methodology were routinely well above this criteria, but contained particulate bound PAHs as well as PAHs bound by dissolved organic carbon (DOC) which are not available for bioconcentration. Average water concentrations of dissolved PAHs determined using SPMDs were also above this criteria. Variables used for determining water concentration included sampling rate at the exposure temperature, length of exposure and estimation of biofouling of SPMD surface.

  17. Emissions of Polycyclic Aromatic Hydrocarbons from Natural Gas Extraction into Air.

    Science.gov (United States)

    Paulik, L Blair; Donald, Carey E; Smith, Brian W; Tidwell, Lane G; Hobbie, Kevin A; Kincl, Laurel; Haynes, Erin N; Anderson, Kim A

    2016-07-19

    Natural gas extraction, often referred to as "fracking", has increased rapidly in the United States in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. Levels of benzo[a]pyrene, phenanthrene, and carcinogenic potency of PAH mixtures were highest when samplers were closest to active wells. PAH levels closest to natural gas activity were comparable to levels previously reported in rural areas in winter. Sourcing ratios indicated that PAHs were predominantly petrogenic, suggesting that PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. At sites closest to active wells, the risk estimated for maximum residential exposure was 0.04 in a million, which is below the U.S. Environmental Protection Agency's acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest from them. This work suggests that natural gas extraction is contributing PAHs to the air, at levels that would not be expected to increase cancer risk.

  18. [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.

  19. Cancer risk assessments of Hong Kong soils contaminated by polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Man, Yu Bon [School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Lin’an, Zhejiang 311300 (China); State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China); Kang, Yuan [State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China); School of Chemistry and Environment, South China Normal University, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Higher Education Mega Center, Guangzhou 510006 (China); Wang, Hong Sheng [State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China); Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Lau, Winifred; Li, Hui; Sun, Xiao Lin [State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China); Giesy, John P. [Department of Biology and Chemistry and State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR (China); Chow, Ka Lai [State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China); Wong, Ming Hung, E-mail: mhwong@hkbu.edu.hk [School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Lin’an, Zhejiang 311300 (China); State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong SAR (China)

    2013-10-15

    Highlights: ► High levels of soil organic matter in soils render PAHs more resistant to degradation. ► Open burning site contain high concentrations of PAHs in Hong Kong. ► Car dismantling workshop can increase potential cancer risk on human. -- Abstract: The aim of this study was to evaluate soils from 12 different land use types on human cancer risks, with the main focus being on human cancer risks related to polycyclic aromatic hydrocarbons (PAHs). Fifty-five locations were selected to represent 12 different types of land use (electronic waste dismantling workshop (EW (DW)); open burning site (OBS); car dismantling workshop (CDW) etc.). The total concentrations of 16 PAHs in terms of total burden and their bioaccessibility were analysed using GC/MS. The PAHs concentrations were subsequently used to establish cancer risks in humans via three exposure pathways, namely, accident ingestion of soil, dermal contact soil and inhalation of soil particles. When the 95th centile values of total PAH concentrations were used to derive ingestion and dermal cancer risk probabilities on humans, the CDW land use type indicated a moderate potential for cancerous development (244 × 10{sup −6} and 209 × 10{sup −6}, respectively). Bioaccessible PAHs content in soil samples from CDW (3.60 × 10{sup −6}) were also classified as low cancer risk. CDW soil possessed a higher carcinogenic risk based on PAH concentrations. Bioremediation is recommended to treat the contaminated soil.

  20. 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.

  1. EU marker polycyclic aromatic hydrocarbons in food supplements: analytical approach and occurrence.

    Science.gov (United States)

    Zelinkova, Zuzana; Wenzl, Thomas

    2015-01-01

    Several food supplements comprising botanical, oil and bee products collected from retail markets in different countries were tested for the occurrence of 4 EU marker Polycyclic aromatic hydrocarbons (PAHs; benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene). A robust GC/MS-based stable-isotope dilution method was used taking into account the differences in the type of matrices. The accuracy of the results was assessed by implementing several quality control tools. Sixty-eight samples of 94 analysed products exceeded the level of 0.5 μg/kg for the sum of the four EU marker PAHs (ΣPAH4). Benzo[a]pyrene exceeded the limit of quantification in 49 samples. The PAH with the highest abundance in all products was chrysene. On average, propolis extracts and other bee products showed relatively high levels of ΣPAH4 (mean 188.2 μg/kg), whereas the contamination levels of fish oil supplements were very low or mostly undetectable. Considerably high ΣPAH4 amounts found in some samples could remarkably increase the daily exposure of consumers to PAHs, demonstrating the need for continuous monitoring of ΣPAH4 in food supplements.

  2. Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Mercury in Oysters (Crassostrea rhizophorae from Two Brazilian Estuarine Zones

    Directory of Open Access Journals (Sweden)

    Ronaldo J. Torres

    2012-01-01

    Full Text Available Nowadays, organisms are increasingly being used in biomonitoring to assess bioavailability and bioaccumulation of contaminants. This approach can use both native and transplanted organisms in order to accomplish this task. In Brazil, most of the studies related to bioaccumulation of contaminants in oysters deal with metals. The present work employs this kind of test in Brazilian coastal estuaries (Santos and Paranaguá to evaluate total mercury and polycyclic aromatic hydrocarbon contamination in sediments and oysters (native and caged Crassostrea rhizophorae. The methodologies employed were based on known USEPA methods. Results have shown a significant contamination in Santos sediments and consequent bioavailability of organisms. Paranaguá sediments presented lower contamination in sediments, but native oysters were able to accumulate total Hg. The experiments done with caged oysters did not show significant bioaccumulation of Hg and PAHs in the Paranaguá site, but proved to be an excellent tool to assess bioavailability in the Santos estuary since they were able to bioaccumulate up to 1,600% of total PAH in the samples from the inner part of this estuary when compared to control organisms. Multivariate statistical analyses employed to these results have separated the sites evaluated and the most contaminated samples from the least contaminated.

  3. 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.

  4. Assessing hazardous risks of human exposure to temple airborne polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Chiang, Kuo-Chih; Chio, Chia-Pin; Chiang, Yu-Hui; Liao, Chung-Min

    2009-07-30

    We proposed an integrated probabilistic risk assessment framework based on reported data to quantify human health risks of temple goers/workers to airborne polycyclic aromatic hydrocarbons (PAHs) from incense burning in typical Taiwanese temples. The framework probabilistically integrates exposure, human respiratory tract, and incremental lifetime cancer risk (ILCR) models to quantitatively estimate size-dependent PAHs exposure in human lung regions and cancer risks for temple goers (moderate and high exposures) and temple workers (extreme exposure). Our results show that the ILCRs are greater than the acceptable level of 10(-6) for extreme and high exposure groups through inhalation route. The result also indicates that the higher ILCRs (10(-6) to 10(-4)) are found in ingestion and dermal contact routes for temple goers/workers. For personal extreme exposure to carcinogenic PAH in the temple, 95% probability total ILCR (TILCR) (9.87 x 10(-4) to 1.13 x 10(-3)) is much greater than the range of 10(-6) to 10(-4), indicating high potential health risk to temple workers. For temple goers with high and moderate exposure groups, however, the 95% probability TILCRs were estimated from 6.44 x 10(-5) to 7.50 x 10(-5) and 5.75 x 10(-6) to 6.99 x 10(-6), respectively. This study successfully offers a scientific basis for risk analysis due to incense burning to enhance broad risk management strategies for temple indoor air quality.

  5. Distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) from Liaohe estuarine wetland soils.

    Science.gov (United States)

    Lang, Yinhai; Wang, Nannan; Gao, Huiwang; Bai, Jie

    2012-09-01

    Thirty-one surface soil samples were collected from Liaohe estuarine wetland in October 2008 and May and August 2009. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), identified as priority pollutants by the US EPA, were measured by gas chromatography. PAHs were predominated by three- and four-ring compounds. The total PAH concentrations ranged from 704.7 to 1,804.5 μg/kg with a mean value of 1,001.9 μg/kg in October 2008, from 509.7 to 1,936.9 μg/kg with an average of 887.1 μg/kg in May 2009, and from 293.4 to 1,735.9 μg/kg with a mean value of 675.4 μg/kg in August 2009. The PAH concentration detected at most sites shared the same pattern, with maximum concentrations during the autumn (October) and minimum concentrations during the summer (August). The ecological risk assessment of PAHs showed that adverse effects would occasionally occur in the soils from Liaohe estuarine wetland based on the effects range low (ERL)/effects range median and the toxic equivalency factors. The results revealed that some of the individual PAHs were in excess of ERL which implied possible acute adverse biological effects. The BaP(eq) values in some sites surpassed the Dutch target value. Therewith, quite a part of soils in the wetland were subjected to potential ecological risks.

  6. EU marker polycyclic aromatic hydrocarbons in food supplements: analytical approach and occurrence

    Science.gov (United States)

    Zelinkova, Zuzana; Wenzl, Thomas

    2015-01-01

    Several food supplements comprising botanical, oil and bee products collected from retail markets in different countries were tested for the occurrence of 4 EU marker Polycyclic aromatic hydrocarbons (PAHs; benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene). A robust GC/MS-based stable-isotope dilution method was used taking into account the differences in the type of matrices. The accuracy of the results was assessed by implementing several quality control tools. Sixty-eight samples of 94 analysed products exceeded the level of 0.5 μg/kg for the sum of the four EU marker PAHs (ΣPAH4). Benzo[a]pyrene exceeded the limit of quantification in 49 samples. The PAH with the highest abundance in all products was chrysene. On average, propolis extracts and other bee products showed relatively high levels of ΣPAH4 (mean 188.2 μg/kg), whereas the contamination levels of fish oil supplements were very low or mostly undetectable. Considerably high ΣPAH4 amounts found in some samples could remarkably increase the daily exposure of consumers to PAHs, demonstrating the need for continuous monitoring of ΣPAH4 in food supplements. PMID:26467752

  7. Time trend of polycyclic aromatic hydrocarbon emission factors from motor vehicles

    Science.gov (United States)

    Tao, Shu; Shen, Huizhong; Wang, Rong; Sun, Kang

    2010-05-01

    Motor vehicle is an important emission source of polycyclic aromatic hydrocarbons (PAHs) and this is particularly true in urban areas. Motor vehicle emission factors (EFs) for individual PAH compound reported in the literature varied for 4 to 5 orders of magnitude, leading to high uncertainty in emission estimation. In this study, the major factors affecting EFs were investigated and characterized by regression models. Based on the model developed, a motor vehicle PAH emission inventory at country level was developed. It was found that country and model year are the most important factors affecting EFs for PAHs. The influence of the two factors can be quantified by a single parameter of per capita gross domestic production (purchasing power parity), which was used as the independent variables of the regression models. The models developed using randomly selected 80% of measurements and tested with the remained data accounted for 28 to 48% of the variations in EFs for PAHs measured in 16 countries over 50 years. The regression coefficients of the EF prediction models were molecular weight dependent. Motor vehicle emission of PAHs from individual countries in the world in 1985, 1995, 2005, 2015, and 2025 were calculated and the global emission of total PAHs were 470, 390, and 430 Gg in 1985, 1995, and 2005 and will be 290 and 130 Gg in 2015 and 2025, respectively. The emission is currently passing its peak and will decrease due to significant decrease in China and other developing countries.

  8. 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...

  9. Highly selective detection of oil spill polycyclic aromatic hydrocarbons using molecularly imprinted polymers for marine ecosystems.

    Science.gov (United States)

    Krupadam, Reddithota J; Nesterov, Evgueni E; Spivak, David A

    2014-06-15

    Im*plications due to oil spills on marine ecosystems have created a great interest toward developing more efficient and selective materials for oil spill toxins detection and remediation. This research paper highlights the application of highly efficient molecularly imprinted polymer (MIP) adsorbents based on a newly developed functional crosslinker (N,O-bismethacryloyl ethanolamine, NOBE) for detection of highly toxic polycyclic aromatic hydrocarbons (PAHs) in seawater. The binding capacity of MIP for oil spill toxin pyrene is 35 mg/g as compared to the value of 3.65 mg/g obtained using a non-imprinted polymer (NIP). The selectivity of all three high molecular weight PAHs (pyrene, chrysene and benzo[a]pyrene) on the NOBE-MIP shows an excellent selective binding with only 5.5% and 7% cross-reactivity for chrysene and benzo[a]pyrene, respectively. Not only is this particularly significant because the rebinding solvent is water, which is known to promote non-selective hydrophobic interactions; the binding remains comparable under salt-water conditions. These selective and high capacity adsorbents will find wide application in industrial and marine water monitoring/remediation.

  10. Quantification of polynuclear aromatic hydrocarbons in transformer oils by enzyme immunoassay.

    Science.gov (United States)

    Kim, I S; Ritchie, L; Setford, S; Allen, M; Wilson, G; Heywood, R; Pahlavanpour, B; Saini, S

    2001-01-01

    Many polynuclear aromatic hydrocarbons (PAHs) are either known or suspected carcinogens and are a common constituent of mineral oils. Due to the large number of possible PAH structures, standard quantification methods fail since they either lack specificity or are too complex, requiring individual fractionation, identification, and quantification. A rapid, low-cost, novel analytical screening method, incorporating a silica-based solid-phase extraction (SPE) method linked to co-solvent dilution and quantification of total and carcinogenic PAH levels by immunoassay, is reported here. The method yielded high extraction efficiencies and minimal matrix effects. This novel approach yielded total and carcinogenic PAH levels x 5.7 and x 126, respectively, lower than that recorded by the industry-recognised BS2000 Pt. 346 (IP346) method which estimates the polyaromatic carbon (PAC) content of oils by gravimetry. The method is expected to be of benefit where an indication of PAH levels in oils is important for purchasing, management or disposal purposes and also for risk assessment and for appropriate labelling of oils in line with current legislation.

  11. Effects of oil pipeline explosion on ambient particulate matter and their associated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Zhao, Yue; Cao, Lixin; Zhou, Qing; Que, Qiming

    2015-01-01

    Effects of the oil pipeline explosion on PM(2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and their substituted (alkylated, nitrated, oxygenated, hydroxyl and chlorinated) derivatives are assessed near the accident scene of Qingdao, China. Compared with those in TSP-PM(2.5), gaseous phase, burn residue and unburned crude oil, eighty-nine PAHs in PM(2.5) are identified and quantified to investigate the composition, temporal and spatial distribution, and sources. The concentrations of PM(2.5)-associated parent PAHs increase approximately seven times from the non-explosion samples to the explosion samples (mean ± standard deviation: 112 ± 2 vs 764 ± 15 ng/m(3)), while some substituted products (nitro- and oxy-) increase by two orders of magnitude (3117 ± 156 pg/m(3) vs 740 ± 37 ng/m(3)). The toxicity evaluation indicates the BaP equivalent concentrations (based on the US EPA's toxicity factors) in PM(2.5) are much higher than those in the other phases, especially for a long duration after the tragic accident.

  12. Behaviour of polycyclic aromatic hydrocarbons (PAH) in soils under freeze-thaw cycles

    Science.gov (United States)

    Zschocke, Anne; Schönborn, Maike; Eschenbach, Annette

    2010-05-01

    The arctic region will be one of the most affected regions by climate change due to the predicted temperature rise. As a result of anthropogenic actions as mining, exploration and refining as well as atmospheric transport pollutions can be found in arctic soils. Therefore questions on the behaviour of organic contaminants in permafrost influenced soils are of high relevance. First investigations showed that permafrost can act as a semi-permeable layer for PAH (Curtosi et al., 2007). Therefore it can be assumed that global warming could result in a mobilization of PAH in these permafrost influenced soils. On the other hand a low but detectable mineralization of organic hydrocarbons by microorganisms under repeated freeze-thaw cycles was analysed (Börresen et al. 2007, Eschenbach et al. 2000). In this study the behaviour and distribution of PAH under freezing and periodically freezing and thawing were investigated in laboratory column experiments with spiked soil materials. Two soil materials which are typical for artic regions, a organic matter containing melt water sand and a well decomposed peat, were homogeneously spiked with a composite of a crude oil and the PAH anthracene and benzo(a)pyrene. After 14days preincubation time the soil material was filled in the laboratory columns (40cm high and 10 cm in diameter). Based on studies by Chuvilin et al. (2001) the impact of freezing of the upper third of the column from the surface downwards was examined. The impact of freezing was tested in two different approaches the first one with a single freezing step and the second one with a fourfold repeated cycle of freezing and thawing which takes about 6 or 7 days each. The experimental design and very first results will be shown and discussed. In some experiments with the peat a higher concentration of anthracene and benzo(a)pyrene could be detected below the freezing front in the unfrozen part of the column. Whereas the concentration of PAH had slightly decreased in

  13. Evaluation of environmental levels of aromatic hydrocarbons in gasoline service stations by gas chromatography.

    Science.gov (United States)

    Periago, J F; Zambudio, A; Prado, C

    1997-08-22

    The volume of gasoline sold in refuelling operations and the ambient temperature, can increase significantly the environmental levels of aromatic hydrocarbon vapours and subsequently, the occupational risk of gasoline service station attendants, specially in the case of benzene. We have evaluated the occupational exposure to aromatic hydrocarbons by means of personal-breathing-zone samples of gasoline vapours in a service station attendant population. This evaluation was carried out using diffusive samplers, in two periods at quite different temperatures (March and July). A significant relationship between the volume of gasoline sold during the shift and the ambient concentration of benzene, toluene, and xylenes was found for each worker sampled. Furthermore a significant difference was found between the time-weighted average concentration of aromatic compounds measured in March, with ambient temperatures of 14-15 degrees C and July, with temperatures of 28-30 degrees C. In addition, 20% of the population sampled in the last period were exposed to a time-weighted average concentration of benzene above the proposed Threshold Limit Value of 960 micrograms/m(3) of the American Conference of Governmental Industrial Hygienists (ACGIH).

  14. Electron affinities of aromatic hydrocarbons and disproportionation of their radical-anions

    Energy Technology Data Exchange (ETDEWEB)

    Szwarc, M.

    1986-09-01

    Electron affinities of aromatic hydrocarbons measured in the gas-phase and in solutions are compared. The experimental methods used for their determination are briefly reviewed. The reduction yields the respective radical-anions. Radical-anions may undergo disproportionation, a reaction described by the scheme: 2A/sup -/ . , Cat/sup =/ in equilibrium A + A/sup 2-/, 2 Cat/sup +/, K/sub dipr/. The disproportionation constant, K/sub dipr/, is greatly affected by the nature of aromatic hydrocarbon, of the cation, and of the solvent. Variation of each of these factors is illustrated. Variation of the cation and solvent results in changes of the disproportionation constant as large as factors of 10/sup 25/. The causes of these variations are rationalized and discussed in terms of the respective ..delta..H and ..delta..S. Kinetics of disproportionation was investigated by flash-photolysis techniques. The experimental approach is described. The peculiarities of Ba salts deserved some discussion to clarify the nature of those salts. The effect of disproportionation on reactions of radical-anions are described: namely on cis-trans isomerization of stilbenes, on protonation of radical-anions of anthracene an perylene, on dissociation of radical anions of aromatic derivatives ethane, etc.

  15. Docosahexaenoic acid regulates gene expression in HUVEC cells treated with polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Gdula-Argasińska, Joanna; Czepiel, Jacek; Totoń-Żurańska, Justyna; Jurczyszyn, Artur; Perucki, William; Wołkow, Paweł

    2015-07-16

    The molecular mechanism of inflammation and carcinogenesis induced by exposure of polycyclic aromatic hydrocarbons (PAHs) is not clearly understood. Our study was undertaken due to the strong pro-carcinogenic potential and reactivity of PAH-metabolites, as well as the susceptibility of polyunsaturated fatty acids to oxidation. The aim of this study was to evaluate the pro- or anti-inflammatory impact of n-3 docosahexaenoic acid on human primary umbilical vein endothelial cells (HUVEC) exposed to polycyclic aromatic hydrocarbons. We analysed the influence of docosahexaenoic acid (DHA) and/or PAHs supplementation on the fatty acid profile of cell membranes, on cyclooxygenase-2 (COX-2), aryl hydrocarbon receptor (AHR), and glutathione S transferase Mu1 (GSTM1) protein expression as well as on the prostaglandin synthase 2 (PTGS2), AHR, GSTM1, PLA2G4A, and cytochrome P450 CYP1A1 gene expression. We observed that COX-2 and AHR protein expression was increased while GSTM1 expression was decreased in cells exposed to DHA and PAHs. Docosahexaenoic acid down-regulated CYP1A1 and up-regulated the AHR and PTGS2 genes. Our findings suggested that DHA contributes significantly to alleviate the harmful effects caused by PAHs in endothelial cells. Moreover, these results suggest that a diet rich in n-3 fatty acids is helpful to reduce the harmful effects of PAHs exposure on human living in heavily polluted areas.

  16. Engineered Antibodies for Monitoring of Polynuclear Aromatic Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Alexander E. Karu Ph.D; Victoria A. Roberts Ph.D.; Qing X. Li, Ph.D.

    2002-01-17

    This project was undertaken to fill needs in ODE's human and ecosystem health effects research, site remediation, rapid emergency response, and regulatory compliance monitoring programs. Doe has greatly stimulated development and validation of antibody-based, rapid, field-portable detection systems for small hazardous compounds. These range from simple dipsticks, microplate enzyme-linked immunosorbent assays (ELISAs), and hand-held colorimeters, to ultrasensitive microfluidic reactors, fiber-optic sensors and microarrays that can identify multiple analytes from patterns of cross-reactivity. Unfortunately, the technology to produce antibodies with the most desirable properties did not keep pace. Lack of antibodies remains a limiting factor in production and practical use of such devices. The goals of our project were to determine the chemical and structural bases for the antibody-analyte binding interactions using advanced computational chemistry, and to use this information to create useful new binding properties through in vitro genetic engineering and combinatorial library methods.

  17. 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}.

  18. Monitoring aromatic hydrocarbon biodegradation by functional marker genes

    Energy Technology Data Exchange (ETDEWEB)

    Nyyssoenen, Mari [Technical Research Centre of Finland, Espoo (Finland)], E-mail: mari.nyyssonen@vtt.fi; Piskonen, Reetta; Itaevaara, Merja [Technical Research Centre of Finland, Espoo (Finland)

    2008-07-15

    The development of biological treatment technologies for contaminated environments requires tools for obtaining direct information about the biodegradation of specific contaminants. The potential of functional gene array analysis to monitor changes in the amount of functional marker genes as indicators of contaminant biodegradation was investigated. A prototype functional gene array was developed for targeting key functions in the biodegradation of naphthalene, toluene and xylenes. Internal standard probe based normalization was introduced to facilitate comparison across multiple samples. Coupled with one-colour hybridization, the signal normalization improved the consistency among replicate hybridizations resulting in better discrimination for the differences in the amount of target DNA. During the naphthalene biodegradation in a PAH-contaminated soil slurry microcosm, the normalized hybridization signals in naphthalene catabolic gene probes were in good agreement with the amount of naphthalene-degradation genes and the production of {sup 14}CO{sub 2}. Gene arrays provide efficient means for monitoring of contaminant biodegradation in the environment. - Functional gene array analysis coupled with one-colour hybridization and internal standard based signal normalization provides efficient tool for monitoring contaminant biodegradation processes.

  19. Determination of polycyclic aromatic hydrocarbons in soy isoflavone nutraceutical products by gas chromatography coupled to triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Ruiz-Delgado, Ana; Martínez-Domínguez, Gerardo; Romero-González, Roberto; López-Ruiz, Rosalía; Frenich, Antonia Garrido

    2016-02-01

    Thirteen polycyclic aromatic hydrocarbons have been determined in soy-based nutraceutical products. First, an optimization of extraction procedure was performed, and a solid-liquid extraction assisted by sonication and a dilute and shoot procedure were compared, selecting the dilute and shoot approach for the extraction of target compounds, utilizing a mixture of acetone/n-hexane (1:1 v/v) as extractant solvent. After this, a clean-up step was needed bearing in mind the complexity of these matrices. Dispersive solid-phase extraction, using a mixture of C18 and Zr-Sep+ (25 mg/mL each) was used. The separation was achieved by gas chromatography and detection with triple quadrupole tandem mass spectrometry. For quantification purposes, matrix-matched calibration was used. The validation was applied at three concentration levels (20, 100 and 250 μg/kg), obtaining recoveries between 70 and 120% and precision values equal to or lower than 23%. Limits of detection and quantification were below 8 and 20 μg/kg, respectively. The method was applied in 11 samples, detecting five polycyclic aromatic hydrocarbons at concentrations ranging from 4.1 to 18.5 μg/kg.

  20. Genomic insights into the metabolic potential of the polycyclic aromatic hydrocarbon degrading sulfate-reducing Deltaproteobacterium N47.

    Science.gov (United States)

    Bergmann, Franz; Selesi, Draženka; Weinmaier, Thomas; Tischler, Patrick; Rattei, Thomas; Meckenstock, Rainer U

    2011-05-01

    Anaerobic degradation of polycyclic aromatic hydrocarbons (PAHs) is an important process during natural attenuation of aromatic hydrocarbon spills. However, knowledge about metabolic potential and physiology of organisms involved in anaerobic degradation of PAHs is scarce. Therefore, we introduce the first genome of the sulfate-reducing Deltaproteobacterium N47 able to catabolize naphthalene, 2-methylnaphthalene, or 2-naphthoic acid as sole carbon source. Based on proteomics, we analysed metabolic pathways during growth on PAHs to gain physiological insights on anaerobic PAH degradation. The genomic assembly and taxonomic binning resulted in 17 contigs covering most of the sulfate reducer N47 genome according to general cluster of orthologous groups (COGs) analyses. According to the genes present, the Deltaproteobacterium N47 can potentially grow with the following sugars including d-mannose, d-fructose, d-galactose, α-d-glucose-1P, starch, glycogen, peptidoglycan and possesses the prerequisites for butanoic acid fermentation. Despite the inability for culture N47 to utilize NO(3) (-) as terminal electron acceptor, genes for nitrate ammonification are present. Furthermore, it is the first sequenced genome containing a complete TCA cycle along with the carbon monoxide dehydrogenase pathway. The genome contained a significant percentage of repetitive sequences and transposase-related protein domains enhancing the ability of genome evolution. Likewise, the sulfate reducer N47 genome contained many unique putative genes with unknown function, which are candidates for yet-unknown metabolic pathways.

  1. Distribution and Geochemical Implication of Aromatic Hydrocarbons across the Meishan Permian-Triassic Boundary

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Aromatic compounds extracted from sedimentary rocks can reflect environmental conditions, organic sources and maturity. The aromatics, identified in association with mass extinction in particular, would provide a signature assisting our understanding of the causes of the biotic crisis. Aromatic hydrocarbons were fractionated from the total lipid extracts of 37 samples taken from the Permian Triassic boundary (beds 23 to 34) of section B at Meishan(煤山),Zhejiang(浙江)Province in South China. These aromatics were analyzed by using gas chromatography-mass spectrometry (GC-MS). Main compounds identified include naphthalene, phenanthrenes, fluorene, dibenzothiophene, dibenzofuran, fluoranthene, pyrene and some of their methyl homologues. The indices of methyl phenanthrene distribution fraction indicate the comparable maturity (within the oil window, 0.7% - 1.0% of the mean vitrinite reflectance) of the organic matter throughout the whole profile analyzed. The ratio of dibenzothiophene to phenanthrene (DBT/PHN) varies generally at a comparable pace with lithology. Significantly,a gradual decrease of this ratio was observed within bed 24 limestone, which is probably due to the variation of sedimentary environment. This change is in line with the drop in the carbon isotope composition of carbonate, the loss of the Changhsingian reef ecosystem, and the decrease of cyanobacteria abundance within the bacteria population. The coincidence of these records suggests a close relation between the biotic crisis and marine environmental conditions, and these records clearly show the onset of the biotic crisis prior to event bed 25.

  2. Laboratory studies of polycyclic aromatic hydrocarbons: the search for interstellar candidates

    CERN Document Server

    Joblin, C; Simon, A; Mulas, G

    2009-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are considered as a major constituent of interstellar dust. They have been proposed as the carriers of the Aromatic Infrared Bands (AIBs) observed in emission in the mid-IR. They likely have a significant contribution to various features of the extinction curve such as the 220 nm bump,the far-UV rise and the diffuse interstellar bands. Emission bands are also expected in the far-IR, which are better fingerprints of molecular identity than the AIBs. They will be searched for with the Herschel Space Observatory. Rotational emission is also expected in the mm range for those molecules which carry significant dipole moments. Despite spectroscopic studies in the laboratory, no individual PAH species could be identified. This emphasises the need for an investigation on where interstellar PAHs come from and how they evolve due to environmental conditions: ionisation and dissociation upon UV irradiation, interactions with electrons, gas and dust. There is also evidence for PAH ...

  3. Sorption of polycyclic aromatic hydrocarbons (PAHs) to lignin: effects of hydrophobicity and temperature.

    Science.gov (United States)

    Zhang, Ming; Ahmad, Mahtab; Lee, Sang Soo; Xu, Li Heng; Ok, Yong Sik

    2014-07-01

    The study of the sorption of contaminants to lignin is significant for understanding the migration of contaminants in the environment as well as developing low cost sorbent. In this study, sorption of three polycyclic aromatic hydrocarbons (PAHs), naphthalene, acenaphthene and phenanthrene, to lignin was investigated. Sorption isotherms were well described by both linear and Freundlich sorption models. Sorption coefficients of PAHs to lignin from water obtained from regression of both linear model (K d) and Freundlich model (K f) were highly positively correlated with hydrophobicity of PAHs. The amorphous structure of lignin provided sufficient sorption domain for partitioning of PAHs, and the attraction between PAHs molecules and aromatic fractions in lignin via π-π electron-donor-acceptor (π-π EDA) interaction is hypothesized to provide a strong sorption force. Thermodynamic modeling revealed that sorption of PAHs to lignin was a spontaneous and exothermic process.

  4. Enhanced sorption of polycyclic aromatic hydrocarbons from aqueous solution by modified pine bark.

    Science.gov (United States)

    Li, Yungui; Chen, Baoliang; Zhu, Lizhong

    2010-10-01

    To enhance removal efficiency of natural sorbent with polycyclic aromatic hydrocarbons (PAHs), single-solute and bi-solute sorption of phenanthrene and pyrene onto raw and modified pine bark were investigated. Pine bark was modified using Soxhlet extraction, saponification and acid hydrolysis, yielding six bark fractions with different chemical compositions. Raw pine bark exhibited high affinities with PAHs, and sorption was dominated by partitioning. The relatively nonlinear sorption isotherms of modified bark were attributed to the specific interaction between sorbate and aromatic core of sorbent. Comparison with lipid and suberin, lignin was the most powerful sorption medium, but which was almost completely suppressed by coexisting polysaccharide. After consuming polysaccharide by acid hydrolysis, sorption of pine bark fractions was notably increased (4-17 folds); and sorption of pyrene just decreased 16-34% with phenanthrene as a competitor. These observations suggest that pine bark is of great potential for PAHs removal and can be significantly promoted by acid hydrolysis for environmental application.

  5. [Polycyclic aromatic hydrocarbons in tea and tea infusions].

    Science.gov (United States)

    Ciemniak, Artur; Mocek, Kamila

    2010-01-01

    Tea is the one of most widely consumed beverage in the world. It is generally believed that tea consumption might have health promoting properties. But residues of certain chemical compounds might impose a health threat on tea drinkers. The main contaminants are heavy metals, fluoride, pesticides and even dioxins. Tea lives which possess a high surface area can be contaminated with atmospheric PAHs. The manufacturing processes may also introduce PAHs into tea lives. The aim of his study was to determine the contamination of black, green, red and white teas by PAHs. In this investigation, content of 23 PAH, i.e 16 EPA PAH and 15 EU PAH were determined in 18 brands of tea and its infusions. The analytical procedure was based on ultrasonic extraction for dried tea and liquid-liquid extraction for infusions. All samples were cleaned up by florisil cartridge. The total content of 23 PAH varied between 22.9 microg/kg to 2945.5 microg/kg and 2.7 microg/kg to 63,1 microg/kg microg/kg for BaP. The analysed tea samples showed an increasing presence of PAH in the following order (mean value): black tea tea green tea tea. However the highest content of PAH was found in the one brand of black tea bag both in sum of PAH and BaP content. During tea infusion 1.6% of total PAHs contained in tea was released into the beverage. The dominant PAHs in tea infusion were 2, 3 and 4 rings PAH, while the most toxic compounds were found at trace amounts. The concentrations of total 23 PAHs and BaP in tea infusions ranged from 332.5 ng/dm3 to 2245.9 ng/dm3 and 0.35 ng/dm3 to 18.7 ng/dm3 respectively.

  6. 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

  7. Influence of smoking parameters on the concentration of polycyclic aromatic hydrocarbons (PAHs) in Danish smoked fish

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Christensen, J. H.; Højgård, A.

    2010-01-01

    ), solid-phase extraction (silica gel), and gas chromatography-mass spectrometry analysis. The sum concentration of 25 PAHs (Sigma PAH25) was highest in smoked herring (n = 3) and mackerel fillets (n = 13), with an average concentration of 320 and 235 mu g kg-1, respectively. Lowest average Sigma PAH25......A new method for the analysis of 25 polycyclic aromatic hydrocarbon (PAH) compounds in fish was developed, validated, and used for the quantification of PAHs in 180 industrially smoked fish products. The method included pressurized liquid extraction, gel-permeation chromatography (Bio-beads S-X3...

  8. 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.

  9. Medium scale spatial structures of polycyclic aromatic hydrocarbons in the topsoil of Tianjin area

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.J.; Zheng, Y.; Liu, R.M.; Li, B.G.; Cao, J.; Tao, S. [Peking University, Beijing (China). Dept. of Urban & Environmental Science, MOE Lab. for Earth Surface Process

    2003-07-01

    The spatial distribution patterns of polycyclic aromatic hydrocarbons (PAHs) in soil are important to regional environmental assessment. In this paper, the spatial structural features of sixteen prior PAH compounds in the topsoil of Tianjin area, as well as soil properties, were studied. Results showed that medium scale spatial autocorrelations were well revealed. Spherical models with sills could be used to fit all experimental variograms. The spatial structures of PAHs contents demonstrated significant anisotropy. Air precipitation caused by the combustion of coal was the key factor in the formation of the spatial structural patterns of PAHs in the topsoil of Tianjin area.

  10. Structures and electronic properties of thin-films of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, Yutaka [Asahi-Kasei Corporation, 2-1 Samejima, Fuji, Shizuoka (Japan)], E-mail: natsume.yc@om.asahi-kasei.co.jp; Minakata, Takashi; Aoyagi, Takeshi [Asahi-Kasei Corporation, 2-1 Samejima, Fuji, Shizuoka (Japan)

    2009-03-02

    We report the fabrication and characterization of organic thin-film transistors (TFTs) using several polycyclic aromatic hydrocarbons (PAHs). Pentacene, ovalene, dibenzocoronene and hexabenzocoronene were deposited as organic semiconductors on silicon wafers with gold electrodes as the bottom-contact configuration of the TFTs. The pentacene TFT showed the highest field-effect mobility of more than 0.1 cm{sup 2}/Vs in comparison with the other PAHs. The results clarified that the high field-effect mobility of the pentacene thin film is due to large grain size and intrinsic electronic properties.

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

    DEFF Research Database (Denmark)

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

    Recently, there has been an augmented focus on the increasing amount of pesticides, drug residues and endocrine disruptors present in waste and drinking water1. These pollutants represent a challenge in water purification since they may be hazardous to human health even in low doses2. Cyclodextrins...... 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....

  12. Contamination of soils in the urbanized areas of Belarus with polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Kukharchyk, T. I.; Khomich, V. S.; Kakareka, S. V.; Kurman, P. V.; Kozyrenko, M. I.

    2013-02-01

    The content of polycyclic aromatic hydrocarbons (PAHs) in the soils of urbanized areas, including the impact zones of Belarus, were studied. The concentrations of 16 PAHs in the soils were determined for individual and high-rise building zones, forests, and forest parks of Belarus. The levels of the PAH accumulation in the soils of different industrial enterprises and boiler stations were analyzed. Possible sources of soil contamination with PAHs were considered, and the structure of the PAHs in the soils was shown. The levels of the soil contamination were determined from the regulated parameters for individual compounds and the sum of 16 PAHs.

  13. Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China

    Science.gov (United States)

    Liu, Jihua; Hu, Ningjing; Shi, Xuefa

    2015-04-01

    Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China Liu Jihua, Hu Ningjing, Shi Xuefa First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous organic contaminants in the environment. Indeed, 16 PAH compounds have been listed as priority pollutants by the United States Environmental Protection Agency and the European Union because of their potential toxicity to humans and ecosystems. As POPs are released or escape into the environment, their global accumulation in marine sediments generates a complex balance between inputs and outputs. Furthermore, PAHs in coastal sediments can serve as effective tracers of materials transport from land-to-sea (Fang et al., 2009). Hence, investigations of PAHs in sediments can provide useful information for further understanding of environmental processes and material transport. In this study, sixteen polycyclic aromatic hydrocarbons (PAHs) were extracted from a total of 112 surface sediment samples collected across the entire territory of the Bohai Sea. The detectable concentrations of PAHs ranged from 97.2 to 300.7 ng/g across all samples, indicating low contamination levels of PAHs compared with reported values for other coastal sediments in China and developed countries. The highest concentrations were found within three belts in the vicinity of Luan River Estuary-Qinhuangdao Harbor, the Cao River Estuary-Bohai Sea Center, and north of the Yellow River Estuary. The distribution patterns of PAHs and source identification implied that PAH contamination in the Bohai Sea mainly originates from offshore oil exploration, sewage discharge from rivers and shipping activities. Further Principal components analysis (PCA)/multivariate linear regression (MLR) analysis suggested that the contributions of spilled oil products (petrogenic), coal combustion and traffic

  14. Dermal uptake of polycyclic aromatic hydrocarbons after hairwash with coal-tar shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Schooten, F.-J. van; Moonen, E.J.C.; Rhijnsburger, E.; Agen, B. van; Thijssen, H.H.W.; Kleinjans, J.C.S. [University of Limburg, Maastricht (Netherlands). Dept. of Health Risk Analysis and Toxicology

    1994-11-26

    Describes an experiment to assess the dermal uptake of polycyclic aromatic hydrocarbons (PAHs) after hairwashing with coal tar antidandruff shampoo. The urinary excretion of 1-hydroxypyrene (1-OH-P), a PAH metabolile was used to assess internal dose of PAH. A single use of coal tar shampoo resulted in increased 1-OH-P excretion in all members of the experimental group compared with the control group using a non-coal tar antidandruff shampoo. It is suggested that repeated use of coal tar shampoo would result in a high internal dose of carcinogenic PAH. 5 refs., 1 fig.

  15. POLYCYCLIC AROMATIC HYDROCARBONS (PAHS IN SEAFOODS CAUGHT IN CORIGLIANO CALABRO GULF (CS,ITALY

    Directory of Open Access Journals (Sweden)

    R. Marrone

    2012-08-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs were determined by high performance liquid chromatography (HPLC with fluorescence detection in seafoods (Merluccius merluccius, Arnoglossus laterna, Scomber japonicus, Penaeus kerathurus, Eledone cirrhosa collected along coasts of Corigliano Calabro gulf (Calabria Region - Italy. The results showed that Bap levels exceeded the limit fixed by EU Regulation 1881/2006 in only four samples of Merluccius merluccius, Arnoglossus laterna and Scomber japonicus particularly. PAH concentrations detected in samples caught in winter were higher than those found in summer.

  16. 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...

  17. Batch washing of saturated hydrocarbons and polycyclic aromatic hydrocarbons from crude oil contaminated soils using bio-surfactant

    Institute of Scientific and Technical Information of China (English)

    张文

    2015-01-01

    Desorption of total saturated fractions (i.e. SAT, defined for this study as the summation of the concentrations of the saturated hydrocarbon from n-C10 to n-C26) and polycyclic aromatic fractions (i.e. PAH, defined as the summation of the concentrations of all polycyclic aromatic fractions including the 16 EPA priority PAH) in two types of soils subjected to the changes of pH and salinity and different bio-surfactant concentrations were investigated. In general, compared with the experiments without bio-surfactant addition, adding rhamnolipid to crude oil−water systems at concentrations above its critical micelle concentration (CMC) values benefits SAT and PAH desorption. The results indicate that the change of pH could have distinct effects on rhamnolipid performance concerning its own micelle structure and soil properties. For loam soil, the adsorption of non-aqueous phase liquid (NAPL) and rhamnolipid would be the principle limiting factors during the NAPL removal procedure. For sand soil, less amount of rhamnolipid is adsorbed onto soil. Thus, with the increase of salinity, the solubilization and desorption of rhamnolipid solution are more significant. In summary, the pH and salt sensitivity of the bio-surfactant will vary according to the specific structure of the surfactant characteristics and soil properties.

  18. Indoor emission, dispersion and exposure of total particle-bound polycyclic aromatic hydrocarbons during cooking

    Science.gov (United States)

    Gao, Jun; Jian, Yating; Cao, Changsheng; Chen, Lei; Zhang, Xu

    2015-11-01

    Cooking processes highly contribute to indoor polycyclic aromatic hydrocarbon (PAH) pollution. High molecular weight and potentially carcinogenic PAHs are generally found attached to small particles, i.e., particulate phase PAHs (PPAHs). Due to the fact that indoor particle dynamics have been clear, describing the indoor dynamics of cooking-generated PPAHs within a specific time span is possible. This paper attempted to quantify the dynamic emission rate, simultaneous spatial dispersion and individual exposure of PPAHs using a cooking source. Experiments were conducted in a real-scale kitchen chamber to elucidate the time-resolved emission and effect of edible oil temperature and mass. Numerical simulations based on indoor particle dynamics were performed to obtain the spatial dispersion and individual inhalation intake of PPAHs under different emission and ventilation conditions. The present work examined the preheating cooking stage, at which edible oil is heated up to beyond its smoke point. The dynamic emission rate peak point occurred much earlier than the oil heating temperature. The total PPAH emission ranged from 2258 to 6578 ng upon heating 40-85 g of edible oil. The overall intake fraction by an individual within a period of 10 min, including 3 min for heating and 7 min for natural cooling, was generally ∼1/10,000. An important outcome of this work was that the overall intake fraction could be represented by multiplying the range hood escape efficiency by the inhalation-to-ventilation rate ratio, which would be no greater than the same ratio. The methodology and results of this work were extendible for the number-based assessment of PPAHs. This work is expected to help us understand the health risks due to inhalation exposure to cooking-generated PPAHs in the kitchen.

  19. Statistical Modeling of Occupational Exposure to Polycyclic Aromatic Hydrocarbons Using OSHA Data.

    Science.gov (United States)

    Lee, Derrick G; Lavoué, Jérôme; Spinelli, John J; Burstyn, Igor

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants with multiple variants classified as carcinogenic. The Occupational Safety and Health Administration (OSHA) provided access to two PAH exposure databanks of United States workplace compliance testing data collected between 1979 and 2010. Mixed-effects logistic models were used to predict the exceedance fraction (EF), i.e., the probability of exceeding OSHA's Permissible Exposure Limit (PEL = 0.2 mg/m3) for PAHs based on industry and occupation. Measurements of coal tar pitch volatiles were used as a surrogate for PAHs. Time, databank, occupation, and industry were included as fixed-effects while an identifier for the compliance inspection number was included as a random effect. Analyses involved 2,509 full-shift personal measurements. Results showed that the majority of industries had an estimated EF < 0.5, although several industries, including Standardized Industry Classification codes 1623 (Water, Sewer, Pipeline, and Communication and Powerline Construction), 1711 (Plumbing, Heating, and Air-Conditioning), 2824 (Manmade Organic Fibres), 3496 (Misc. Fabricated Wire products), and 5812 (Eating Places), and Major group's 13 (Oil and Gas Extraction) and 30 (Rubber and Miscellaneous Plastic Products), were estimated to have more than an 80% likelihood of exceeding the PEL. There was an inverse temporal trend of exceeding the PEL, with lower risk in most recent years, albeit not statistically significant. Similar results were shown when incorporating occupation, but varied depending on the occupation as the majority of industries predicted at the administrative level, e.g., managers, had an estimated EF < 0.5 while at the minimally skilled/laborer level there was a substantial increase in the estimated EF. These statistical models allow the prediction of PAH exposure risk through individual occupational histories and will be used to create a job-exposure matrix for use in a population-based case

  20. Spatial and Temporal Distribution of Polycyclic Aromatic Hydrocarbons and Heavy Metals in Stormwater Detention Basin Sediments

    Science.gov (United States)

    Schifman, L. A.; Kasaraneni, V. K.; Boving, T. B.; Craver, V.

    2015-12-01

    Stormwater runoff is a conduit for several pollutants such as polycyclic aromatic hydrocarbons (PAHs) into surface and ground water bodies. The control of runoff and pollutants is typically addressed by best management practices, such as retention/detention ponds. While the effectiveness of catchment basins in runoff volume reduction and removal of some contaminants has been established, very little is known about contaminant fate within these structures. Particularly in coastal regions and places with shallow groundwater tables PAH accumulation in the bottom sediments poses a potential threat for groundwater contamination. The concentrations of PAHs accumulated in the sediments of these catchment basins will primarily depend on the sources of runoff origin and the surrounding land use. Here, five stormwater catchment basins along the I-95 corridor in Rhode Island were selected based on the stormwater runoff origin and land use (industrial, urban, highway, and commercial). To study the stratification of PAHs one foot sediment cores were collected and analyzed for 17 PAHs (16 EPA parent PAH and Retene). The concentrations of PAHs in sediments of detention ponds in urban and industrial land use areas ranged from 20 μg/g to 200 μg/g. Generally higher concentrations of contaminants were found in sediments near the pond inlet and a decreasing concentration gradient is observed laterally and vertically throughout the pond. To compare stormwater ponds in various land use settings a new index based on sediment contamination, pond size and age, and catchment area will be presented. Further, it will be investigated whether BMP maintenance has to be targeted towards pollutant removal to maintain an effective stormwater treatment system.

  1. From Source to Sink of Polycyclic Aromatic Hydrocarbons in Sediments in the East China Seas

    Science.gov (United States)

    Guo, Z.; Lin, T.; Hu, L.

    2014-12-01

    The East China Seas (ECSs), including Bohai Sea (77,000 km2), Yellow Sea (400,000 km2) and East China Sea (770,000 km2) have experienced a great variety of demographic and economic conditions which have a profound influence on the source composition of land-based polycyclic aromatic hydrocarbons (PAHs) in the sediments since ECSs's coasts support about 420 million peoples, provide more than half of the national GDP in China in 2007, and are major emission regions of PAHs in China. Furthermore, the ECSs are downwind of the Asian continental outflow in spring and winter driven by the East Asian monsoon. The sources of 16 USEPA priority PAHs in strategically selected surface sediment samples from the ECSs were apportioned using positive matrix factorization model, and the input pathways of PAHs were also revealed in the regions. Four sources were identified: petroleum residue, vehicular emissions, coal combustion and biomass burning. Petroleum residue was the dominant contributor of PAHs in the coast of the Bohai Bay probably due to Haihe River runoff, oil leakage from ships and offshore oil fields. The PAHs in sediments of the coastal East China Sea were mainly sourced from the Yangtze River discharge into the sea. The combined results of PMF, PCA and composition of PAHs suggest that the atmospheric deposition is the dominate input of PAHs for the open seas of Bohai Sea, East China Sea and Yellow Sea; while river input is the major pathway of PAHs in the estuarine and neighborhood coastal areas. The demographic and economic conditions around the ECSs have profound influence on the origins of the land-based PAHs in the sediments of the open seas.

  2. A reaction mechanism for gasoline surrogate fuels for large polycyclic aromatic hydrocarbons

    KAUST Repository

    Raj, Abhijeet

    2012-02-01

    This work aims to develop a reaction mechanism for gasoline surrogate fuels (n-heptane, iso-octane and toluene) with an emphasis on the formation of large polycyclic aromatic hydrocarbons (PAHs). Starting from an existing base mechanism for gasoline surrogate fuels with the largest chemical species being pyrene (C 16H 10), this new mechanism is generated by adding PAH sub-mechanisms to account for the formation and growth of PAHs up to coronene (C 24H 12). The density functional theory (DFT) and the transition state theory (TST) have been adopted to evaluate the rate constants for several PAH reactions. The mechanism is validated in the premixed laminar flames of n-heptane, iso-octane, benzene and ethylene. The characteristics of PAH formation in the counterflow diffusion flames of iso-octane/toluene and n-heptane/toluene mixtures have also been tested for both the soot formation and soot formation/oxidation flame conditions. The predictions of the concentrations of large PAHs in the premixed flames having available experimental data are significantly improved with the new mechanism as compared to the base mechanism. The major pathways for the formation of large PAHs are identified. The test of the counterflow diffusion flames successfully predicts the PAH behavior exhibiting a synergistic effect observed experimentally for the mixture fuels, irrespective of the type of flame (soot formation flame or soot formation/oxidation flame). The reactions that lead to this synergistic effect in PAH formation are identified through the rate-of-production analysis. © 2011 The Combustion Institute.

  3. Structurally distinct polycyclic aromatic hydrocarbons induce differential transcriptional responses in developing zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Goodale, Britton C. [Department of Environmental and Molecular Toxicology, The Environmental Health Sciences Center, Oregon State University, Corvallis, OR (United States); Tilton, Susan C. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory (United States); Corvi, Margaret M.; Wilson, Glenn R. [Department of Environmental and Molecular Toxicology, The Environmental Health Sciences Center, Oregon State University, Corvallis, OR (United States); Janszen, Derek B. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory (United States); Anderson, Kim A. [Department of Environmental and Molecular Toxicology, The Environmental Health Sciences Center, Oregon State University, Corvallis, OR (United States); Waters, Katrina M. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory (United States); Tanguay, Robert L., E-mail: tanguay.robert@oregonstate.edu [Department of Environmental and Molecular Toxicology, The Environmental Health Sciences Center, Oregon State University, Corvallis, OR (United States)

    2013-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment as components of fossil fuels and by-products of combustion. These multi-ring chemicals differentially activate the aryl hydrocarbon receptor (AHR) in a structurally dependent manner, and induce toxicity via both AHR-dependent and -independent mechanisms. PAH exposure is known to induce developmental malformations in zebrafish embryos, and recent studies have shown cardiac toxicity induced by compounds with low AHR affinity. Unraveling the potentially diverse molecular mechanisms of PAH toxicity is essential for understanding the hazard posed by complex PAH mixtures present in the environment. We analyzed transcriptional responses to PAH exposure in zebrafish embryos exposed to benz(a)anthracene (BAA), dibenzothiophene (DBT) and pyrene (PYR) at concentrations that induced developmental malformations by 120 h post-fertilization (hpf). Whole genome microarray analysis of mRNA expression at 24 and 48 hpf identified genes that were differentially regulated over time and in response to the three PAH structures. PAH body burdens were analyzed at both time points using GC–MS, and demonstrated differences in PAH uptake into the embryos. This was important for discerning dose-related differences from those that represented unique molecular mechanisms. While BAA misregulated the least number of transcripts, it caused strong induction of cyp1a and other genes known to be downstream of the AHR, which were not induced by the other two PAHs. Analysis of functional roles of misregulated genes and their predicted regulatory transcription factors also distinguished the BAA response from regulatory networks disrupted by DBT and PYR exposure. These results indicate that systems approaches can be used to classify the toxicity of PAHs based on the networks perturbed following exposure, and may provide a path for unraveling the toxicity of complex PAH mixtures. - Highlights: • Defined global mRNA expression

  4. Biodegradation kinetics of select polycyclic aromatic hydrocarbon (PAH) mixtures by Sphingomonas paucimobilis EPA505.

    Science.gov (United States)

    Desai, Anuradha M; Autenrieth, Robin L; Dimitriou-Christidis, Petros; McDonald, Thomas J

    2008-04-01

    Many contaminated sites commonly have complex mixtures of polycyclic aromatic hydrocarbons (PAHs) whose individual microbial biodegradation may be altered in mixtures. Biodegradation kinetics for fluorene, naphthalene, 1,5-dimethylnaphthalene and 1-methylfluorene were evaluated in sole substrate, binary and ternary systems using Sphingomonas paucimobilis EPA505. The first order rate constants for fluorene, naphthalene, 1,5-dimethylnaphthalene, and 1-methylfluorene were comparable; yet Monod parameters were significantly different for the tested PAHs. S. paucimobilis completely degraded all the components in binary and ternary mixtures; however, the initial degradation rates of individual components decreased in the presence of competitive PAHs. Results from the mixture experiments indicate competitive interactions, demonstrated mathematically. The generated model appropriately predicted the biodegradation kinetics in mixtures using parameter estimates from the sole substrate experiments, validating the hypothesis of a common rate-determining step. Biodegradation kinetics in mixtures were affected by the affinity coefficients of the co-occurring PAHs and mixture composition. Experiments with equal concentrations of substrates demonstrated the effect of concentration on competitive inhibition. Ternary experiments with naphthalene, 1,5-dimethylnaphthalene and 1-methylfluorene revealed delayed degradation, where depletion of naphthalene and 1,5-dimethylnapthalene occurred rapidly only after the complete removal of 1-methylfluorene. The substrate interactions observed in mixtures require a multisubstrate model to account for simultaneous degradation of substrates. PAH contaminated sites are far more complex than even ternary mixtures; however these studies clearly demonstrate the effect that interactions can have on individual chemical kinetics. Consequently, predicting natural or enhanced degradation of PAHs cannot be based on single compound kinetics as this

  5. Biodegradation of selected UV-irradiated and non-irradiated polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Lehto, Kirsi-Maarit; Puhakka, Jaakko A; Lemmetyinen, Helge

    2003-08-01

    Biodegradation of UV-irradiated anthracene, pyrene, benz[a]anthracene, and dibenz[a,h]anthracene was compared to that of the non-irradiated samples, individually and in synthetic mixtures with enrichment cultures. Combined treatment was repeated for individual anthracene and for the PAH mixture with Sphingomonas sp. strain EPA 505 and Sphingomonas yanoikuyae. Enrichment culture studies were performed on the PAH mixtures in the presence of the main photoproduct of anthracene, pure 9,10-anthracenedione. Photochemically pretreated creosote solutions were also subjected to biodegradation and the results were compared to those of the non-irradiated solutions. The primary interest was on 16 polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by European Union (EU) and the United States Environmental Protection Agency (USEPA). Irradiation accelerated the biodegradation onset for anthracene, pyrene, and benz[a]anthracene when they were treated individually. The biodegradation of irradiated pyrene started with no lag phase and was complete by 122 h whereas biodegradation of the non-irradiated sample had a lag of 280 h and resulted in complete degradation by 720 h. Biodegradation of PAHs was accelerated in synthetic mixtures, especially in the presence of pure 9,10-anthracenedione. In general, irradiation had no effect on the biodegradation of PAHs incubated in synthetic mixtures or with pure cultures. Under current experimental conditions, the UV-irradiation invariably reduced the biodegradation of PAHs in creosote. Based on the results of the present and previous photochemical-biological studies of PAHs, the influence of the photochemical pretreatment on the biodegradation is highly dependent on the compounds being treated and other process parameters.

  6. Double-tagged fluorescent bacterial bioreporter for the study of polycyclic aromatic hydrocarbon diffusion and bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Tecon, R.; Binggeli, O.; van der Meer, J.R. [University of Lausanne, Lausanne (Switzerland). Dept. of Fundamental Microbiology

    2009-09-15

    Bacterial degradation of polycyclic aromatic hydrocarbons (PAHs), ubiquitous contaminants from oil and coal, is typically limited by poor accessibility of the contaminant to the bacteria. In order to measure PAH availability in complex systems, we designed a number of diffusion-based assays with a double-tagged bacterial reporter strain Burkholderia sartisoli RP037-mChe. The reporter strain is capable of mineralizing phenanthrene (PHE) and induces the expression of enhanced green fluorescent protein (eGFP) as a function of the PAH flux to the cell. At the same time, it produces a second autofluorescent protein (mCherry) in constitutive manner. Quantitative epifluorescence imaging was deployed in order to record reporter signals as a function of PAH availability. The reporter strain expressed eGFP proportionally to dosages of naphthalene or PHE in batch liquid cultures. To detect PAH diffusion from solid materials the reporter cells were embedded in 2 cm-sized agarose gel patches, and fluorescence was recorded over time for both markers as a function of distance to the PAH source. eGFP fluorescence gradients measured on known amounts of naphthalene or PHE served as calibration for quantifying PAH availability from contaminated soils. To detect reporter gene expression at even smaller diffusion distances, we mixed and immobilized cells with contaminated soils in an agarose gel. eGFP fluorescence measurements confirmed gel patch diffusion results that exposure to 2-3 mg lampblack soil gave four times higher expression than to material contaminated with 10 or 1 (mg PHE) g{sup -1}.

  7. Contamination, source, and input route of polycyclic aromatic hydrocarbons in historic wastewater-irrigated agricultural soils.

    Science.gov (United States)

    Wang, Ning; Li, Hong-Bo; Long, Jin-Lin; Cai, Chao; Dai, Jiu-Lan; Zhang, Juan; Wang, Ren-Qing

    2012-12-01

    Contamination by polycyclic aromatic hydrocarbons (PAHs) of historic wastewater-irrigated agricultural topsoil (0-5 cm) and the contribution of groundwater irrigation and atmospheric deposition to soil PAHs were studied in a typical agricultural region, i.e. Hunpu region, Liaoning, China. Concentrations of total PAHs ranged from 0.43 to 2.64 mg kg⁻¹ in topsoil, being lower than those found in other wastewater-irrigated areas. The levels of PAHs in soil declined as the distance from a water source increased. Concentrations of individual PAHs were generally higher in upland than in paddy topsoils. The calculated nemerow composite index showed that agricultural soil in the region was "polluted" by PAHs. A human health risk assessment based on the total toxic equivalent concentration showed that the presence of elevated concentrations of PAHs in the soil might pose a great threat to the health of local residents. Ratios of pairs of PAHs and principal component analysis (PCA) showed that pyrogenesis, such as coal combustion, was the main source of PAHs, while petroleum, to some extent, also had a strong influence on PAHs contamination in upland soil. The distribution patterns of individual PAHs and composition of PAHs differed between irrigation groundwater and topsoil, but were similar between atmospheric deposition and topsoil. There were significant linear correlations (r = 0.90; p soils, while no significant relationships were observed between irrigation groundwater and topsoil in levels of PAHs. These suggested that PAHs in agricultural soils were mainly introduced from atmospheric deposition, rather than from groundwater irrigation after the phasing out of wastewater irrigation in the region since 2002. This study provides a reference to ensure agricultural product safety, pollution control, and proper soil management.

  8. Accumulation, allocation, and risk assessment of polycyclic aromatic hydrocarbons (PAHs in soil-Brassica chinensis system.

    Directory of Open Access Journals (Sweden)

    Juan Zhang

    Full Text Available Farmland soil and leafy vegetables accumulate more polycyclic aromatic hydrocarbons (PAHs in suburban sites. In this study, 13 sampling areas were selected from vegetable fields in the outskirts of Xi'an, the largest city in northwestern China. The similarity of PAH composition in soil and vegetation was investigated through principal components analysis and redundancy analysis (RDA, rather than discrimination of PAH congeners from various sources. The toxic equivalent quantity of PAHs in soil ranged from 7 to 202 μg/kg d.w., with an average of 41 μg/kg d.w., which exceeded the agricultural/horticultural soil acceptance criteria for New Zealand. However, the cancer risk level posed by combined direct ingestion, dermal contact, inhalation of soil particles, and inhalation of surface soil vapor met the rigorous international criteria (1 × 10(-6. The concentration of total PAHs was (1052 ± 73 μg/kg d.w. in vegetation (mean ± standard error. The cancer risks posed by ingestion of vegetation ranged from 2×10-5 to 2 × 10(-4 with an average of 1.66 × 10(-4, which was higher than international excess lifetime risk limits for carcinogens (1 × 10(-4. The geochemical indices indicated that the PAHs in soil and vegetables were mainly from vehicle and crude oil combustion. Both the total PAHs in vegetation and bioconcentration factor for total PAHs (the ratio of total PAHs in vegetation to total PAHs in soil increased with increasing pH as well as decreasing sand in soil. The total variation in distribution of PAHs in vegetation explained by those in soil reached 98% in RDA, which was statistically significant based on Monte Carlo permutation. Common pollution source and notable effects of soil contamination on vegetation would result in highly similar distribution of PAHs in soil and vegetation.

  9. Water clusters adsorbed on polycyclic aromatic hydrocarbons: Energetics and conformational dynamics

    Science.gov (United States)

    Simon, Aude; Spiegelman, Fernand

    2013-05-01

    In this work, we present some classical molecular dynamics (MD) simulations and finite temperature infrared (IR) spectra of water clusters adsorbed on coronene (C24H12), a compact polycyclic aromatic hydrocarbon (PAH). The potential energy surface is obtained within the self-consistent-charge density-functional based tight-binding approach with modifications insuring the correct description of water-water and water-PAH interactions. This scheme is benchmarked for the minimal energy structures of (C24H12)(H2O)n (n = 3-10) against density-functional theory (DFT) calculations and for the low-energy isomers of (H2O)6 and (C6H6)(H2O)3 against correlated wavefunction and DFT calculations. A detailed study of the low energy isomers of (C24H12)(H2O)3, 6 complexes is then provided. On-the-fly Born-Oppenheimer MD simulations are performed in the temperature T range 10-350 K for (C24H12)(H2O)n (n = 3-7) complexes. The description of the evolution of the systems with T is provided with emphasis on (C24H12)(H2O)n (n = 3,6). For T in the range 50-150 K, isomerisation processes are observed and when T increases, a solid-to-liquid phase-change like behavior is shown. The desorption of one water molecule is frequently observed at 300 K. The isomerisation processes are evidenced on the finite temperature IR spectra and the results are presented for (C24H12)(H2O)n (n = 3,6). A signature for the edge-coordination of the water cluster on the PAH is also proposed.

  10. Ionization and fragmentation of polycyclic aromatic hydrocarbon clusters in collisions with keV ions

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, H. A. B.; Zettergren, H.; Holm, A. I. S.; Seitz, F.; Schmidt, H. T.; Cederquist, H. [Department of Physics, Stockholm University, SE-106 91, Stockholm (Sweden); Rousseau, P.; Lawicki, A.; Capron, M.; Domaracka, A.; Lattouf, E.; Maclot, S.; Maisonny, R.; Chesnel, J.-Y.; Adoui, L.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Universite de Caen Basse-Normandie, Boulevard Henri Becquerel, BP5133, F-14070 Caen Cedex 5 (France); Manil, B. [Laboratoire de Physique des Laser, CNRS, UMR 7538, Institut Galilee, Universite Paris 13, F-93430, Villetaneuse (France)

    2011-10-15

    We report on an experimental study of the ionization and fragmentation of clusters of k polycyclic aromatic hydrocarbon (PAH) molecules using anthracene, C{sub 14}H{sub 10}, or coronene, C{sub 24}H{sub 12}. These PAH clusters are moderately charged and strongly heated in small impact parameter collisions with 22.5-keV He{sup 2+} ions, after which they mostly decay in long monomer evaporation sequences with singly charged and comparatively cold monomers as dominating end products. We describe a simple cluster evaporation model and estimate the number of PAH molecules in the clusters that have to be hit by He{sup 2+} projectiles for such complete cluster evaporations to occur. Highly charged and initially cold clusters are efficiently formed in collisions with 360-keV Xe{sup 20+} ions, leading to cluster Coulomb explosions and several hot charged fragments, which again predominantly yield singly charged, but much hotter, monomer ions than the He{sup 2+} collisions. We present a simple formula, based on density-functional-theory calculations, for the ionization energy sequences as functions of coronene cluster size, rationalized in terms of the classic electrostatic expression for the ionization of a charged conducting object. Our analysis indicates that multiple electron removal by highly charged ions from a cluster of PAH molecules rapidly may become more important than single ionization as the cluster size k increases and that this is the main reason for the unexpectedly strong heating in these types of collisions.

  11. Sources of polycyclic aromatic hydrocarbons to sediments of the Bohai and Yellow Seas in East Asia

    Science.gov (United States)

    Lin, Tian; Hu, Limin; Guo, Zhigang; Qin, Yanwen; Yang, Zuosheng; Zhang, Gan; Zheng, Mei

    2011-12-01

    The coasts of Bohai Sea (BS) and Yellow Sea (YS) in China support almost one-quarter of its population and provide more than one-third of the national GDP. BS and YS are downwind of the Asian continental outflow in spring and winter as influenced by the East Asian monsoon. This makes the two seas important sinks of land-based pollutants associated with the Asian continental outflow. The sixteen U.S. EPA proposed priority polycyclic aromatic hydrocarbons (PAHs) in 130 surface sediment samples collected from BS and YS were measured. Combined with our previous PAH data of 90 PM2.5 samples from the upwind areas, the sources of the PAHs in BS and YS were apportioned using positive matrix factorization (PMF) modeling. Four sources were identified: petroleum residue, vehicular emissions, coal combustion and biomass burning. Petroleum residue was the dominant contributor of PAHs in the coast of the Bohai Bay probably due to Haihe River runoff, oil leakage from ships and offshore oil fields. The contribution of vehicular emissions in BS was higher than that in YS, and the reverse was true for coal combustion and biomass burning. This difference in the source patterns in the sediments of the two seas could be attributed to the different PAH emission features of the upwind area related to demographic and economic conditions, as well as the marine geography. The ratios of selected 4-6 ring PAHs in the sediments compared well with those of the PM2.5 of the upwind areas, implicating that the particle phase PAHs in the atmosphere play an important role in the source to sink process of the pyrogenic PAHs in the region.

  12. Determination of polycyclic aromatic hydrocarbons in water using an electrochemical DNA biosensor

    Directory of Open Access Journals (Sweden)

    R Manaffar

    2015-08-01

    Full Text Available Background and Objectives: Polycyclic aromatic hydrocarbons (PAHs are widespread environmental contaminants in aquatic environments. These contaminants are generated through oil spills, manufactory processes, and industrial wastes or naturally through the incomplete combustion of coal, oil, gas, and wood waste. Most of these compounds are noted as carcinogenic and mutagenic. Therefore, detection of these pollutants by a sensitive and inexpensive method is very important. Materials and Methods: In this study, an electrochemical DNA biosensor was used to detect PAHs due to its sensitivity, ability, and high response rate. For this purpose, the bovine thymus double-stranded DNA was fixed on a screen-printed electrode. Then, the electrodes electrochemical behavior was investigated. This electrochemical DNA biosensor works upon the difference between the electrochemical response of guanine bases in DNA structure in the presence and absence of PAH compounds. To evaluate the biosensors performance, the response of biosensor to real samples was compared with conventional pollutant determination methods like liquid-liquid chromatography. Results: Optimum conditions were examined for biosensor response including effect of activation potential and time on electrode pretreatment, applied potential for DNA immobilization, and detection potential. Under optimal conditions, the pretreatment of the electrode obtained in 1.6 V for 350s, then the DNA was immobilized on the electrode surface by applying a potential of -0.5 V to detect different PAHs in real samples in the range of micro molar. Conclusion: Electrochemical DNA biosensors are capable of detecting the sum of PAHs in water samples with high accuracy, sensitivity, and low cost compared with chromatographic methods.

  13. A computational study of ethylene–air sooting flames: Effects of large polycyclic aromatic hydrocarbons

    KAUST Repository

    Selvaraj, Prabhu

    2015-11-05

    An updated reduced gas-phase kinetic mechanism was developed and integrated with aerosol models to predict soot formation characteristics in ethylene nonpremixed and premixed flames. A primary objective is to investigate the sensitivity of the soot formation to various chemical pathways for large polycyclic aromatic hydrocarbons (PAH). The gas-phase chemical mechanism adopted the KAUST-Aramco PAH Mech 1.0, which utilized the AramcoMech 1.3 for gas-phase reactions validated for up to C2 fuels. In addition, PAH species up to coronene (C24H12 or A7) were included to describe the detailed formation pathways of soot precursors. In this study, the detailed chemical mechanism was reduced from 397 to 99 species using directed relation graph with expert knowledge (DRG-X) and sensitivity analysis. The method of moments with interpolative closure (MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames at low strain rate sooting conditions were considered, for which the sensitivity of soot formation characteristics to different nucleation pathways were investigated. Premixed flame experiment data at different equivalence ratios were also used for validation. The findings show that higher PAH concentrations result in a higher soot nucleation rate, and that the total soot volume and average size of the particles are predicted in good agreement with experimental results. Subsequently, the effects of different pathways, with respect to pyrene- or coronene-based nucleation models, on the net soot formation rate were analyzed. It was found that the nucleation processes (i.e., soot inception) are sensitive to the choice of PAH precursors, and consideration of higher PAH species beyond pyrene is critical for accurate prediction of the overall soot formation.

  14. Accumulation, allocation, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in soil-Brassica chinensis system.

    Science.gov (United States)

    Zhang, Juan; Fan, Shukai; Du, Xiaoming; Yang, Juncheng; Wang, Wenyan; Hou, Hong

    2015-01-01

    Farmland soil and leafy vegetables accumulate more polycyclic aromatic hydrocarbons (PAHs) in suburban sites. In this study, 13 sampling areas were selected from vegetable fields in the outskirts of Xi'an, the largest city in northwestern China. The similarity of PAH composition in soil and vegetation was investigated through principal components analysis and redundancy analysis (RDA), rather than discrimination of PAH congeners from various sources. The toxic equivalent quantity of PAHs in soil ranged from 7 to 202 μg/kg d.w., with an average of 41 μg/kg d.w., which exceeded the agricultural/horticultural soil acceptance criteria for New Zealand. However, the cancer risk level posed by combined direct ingestion, dermal contact, inhalation of soil particles, and inhalation of surface soil vapor met the rigorous international criteria (1 × 10(-6)). The concentration of total PAHs was (1052 ± 73) μg/kg d.w. in vegetation (mean ± standard error). The cancer risks posed by ingestion of vegetation ranged from 2×10-5 to 2 × 10(-4) with an average of 1.66 × 10(-4), which was higher than international excess lifetime risk limits for carcinogens (1 × 10(-4)). The geochemical indices indicated that the PAHs in soil and vegetables were mainly from vehicle and crude oil combustion. Both the total PAHs in vegetation and bioconcentration factor for total PAHs (the ratio of total PAHs in vegetation to total PAHs in soil) increased with increasing pH as well as decreasing sand in soil. The total variation in distribution of PAHs in vegetation explained by those in soil reached 98% in RDA, which was statistically significant based on Monte Carlo permutation. Common pollution source and notable effects of soil contamination on vegetation would result in highly similar distribution of PAHs in soil and vegetation.

  15. Determination of polycyclic aromatic hydrocarbons in urban street dust: implications for human health.

    Science.gov (United States)

    Lorenzi, Damien; Entwistle, Jane A; Cave, Mark; Dean, John R

    2011-05-01

    The determination of sixteen polycyclic aromatic hydrocarbons in urban street dust has been done. Samples were collected from 12 sampling locations in a city centre location (Newcastle upon Tyne, north east England) and extracted using in situ pressurised fluid extraction followed by gas chromatography mass spectrometry. From the results it was possible to identify three groups, with respect to PAH concentration, with PAH contents ranging between 0.6-2.3 mg kg(-1), 15.6-22.5 mg kg(-1) and 36.1-46.0 mg kg(-1). The total PAH content of samples from these sampling sites has been compared to 22 urban locations around the world; comparable levels were found in these samples compared to the other cities around the world. The potential source of PAHs has been investigated by investigating the proportion of pyrogenic and petrogenic material in urban street dust using specific individual PAH ratios. The results indicate that the PAH content of urban street dust from the chosen sites are more likely to be due to pyrogenic sources i.e. vehicle exhaust emissions. The particle size fractions (PAHs in three selected sampling sites was investigated. In two of the selected sites the PAH content was independent of particle size whereas in sampling site 10 elevated PAH levels are noted in the PAHs was assessed in terms of a mean daily intake (based on an ingestion rate of 100 mg d(-1)). It was found that all 4-6 membered ring PAHs had concentrations in excess of the mean daily intake thereby reflecting a potential health risk, particularly in the smallest size particle fractions.

  16. Runoff pollution impacts of polycyclic aromatic hydrocarbons in street dusts from a stream network town.

    Science.gov (United States)

    Zhao, Hongtao; Yin, Chengqing; Chen, Meixue; Wang, Weidong

    2008-01-01

    Runoff with contaminated street dusts has an environmental risk to the aquatic environment. An assessment of the diffuse pollution of polycyclic aromatic hydrocarbons (PAHs) from a small town and their risks to the township stream network was conducted at Yangtze River delta. This assessment is based on measurements of 16 PAHs from the US EPA priority list by GC-MS in stream water during rainy and dry season, street dusts with different particle sizes, river sediments and suspended solids of urban runoff. The maximum level of PAHs in the stream water (2,323-4,948 ng L(-1)) were found during rainy season, while significantly lower PAHs concentrations (242-998 ng L(-1)) were measured during dry season. The total PAHs ranged from 1,629 to 8,986 microg kg(-1) in the street dusts. Approximately 55% of the total PAHs were associated with street dust particles of diameters less than 250 microm and these accounted for 40% of the total. The town reaches sediments were rich in PAHs and it was suggested as the sink of street dusts. The research findings suggested that size of street dusts, the topographical and hydrological features of the landscape in the stream network were the important factors influencing PAH emitted to the receiving water. The contribution of urban surface runoff could significantly influence PAHs concentration in the stream water. To reduce the pollution of street dust into the stream network, the buffer zone along the hydrological pathway is suggested and the existing street cleaning methods should also be improved.

  17. Polyphenol oxidase activity in subcellular fractions of tall fescue contaminated by polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Ling, Wanting; Lu, Xiaodan; Gao, Yanzheng; Liu, Juan; Sun, Yandi

    2012-01-01

    Understanding enzyme responses to contamination with persistent organic pollutants (POPs) is a key step in the elucidation of POP metabolic mechanisms in plants. However, there is little information available on enzyme activity in subcellular fractions of POP-contaminated plants. To our knowledge, this is the first study to investigate the activities of polyphenol oxidase (PPO) in cell fractions of plants under contamination stress from polycyclic aromatic hydrocarbons (PAHs) using a greenhouse batch technique. Three parameters, E(cell), E(cell-n), and P(cell), denoting the amount of PPO activity, cell fraction content-normalized PPO activity, and proportion of PPO activity in each cell fraction, respectively, were used in this study. Contamination with phenanthrene, as a representative PAH, at a relatively high level (>0.23 mg L⁻¹) in culture solution generally stimulated PPO activity in tall fescue (Festuca arundinacea Schreb.) roots and shoots and their cellular fractions. The amount and distribution proportion of PPO activity in each cell fraction of phenanthrene-contaminated roots and shoots were (in descending order): cell solution > > cell wall > cell organelles. Cell solution was the dominant storage domain of PPO activity and contributed 84.0 and 82.8% of PPO activity in roots and shoots, respectively. The cell wall had the highest density of PPO activity in roots and shoots, based on the highest cell fraction content normalized PPO activity in this cell fraction. Our results provide new information on enzyme responses in plant intracellular fractions to xenobiotic POPs and fundamental information on within-plant POP metabolic mechanisms.

  18. Effect of irradiance spectra on the photoinduced toxicity of three polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, S.A.; Mount, D.R.; Burkhard, L.P.; Ankley, G.T.; Makynen, E.A.; Leonard, E.N.

    2000-05-01

    Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light received. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events underlying phototoxicity. This suggests that variation in light spectra present in natural waters, arising from variation in dissolved organic carbon composition, is an important determinant of phototoxicity risk in specific, PAH-contaminated waterbodies. To quantify the effect of environmentally realistic variation in light spectra on toxicity, brine shrimp (Artemia salina) assays were conducted under various light spectra and with three PAHs (pyrene, fluoranthene, and anthracene) of known phototoxicity potential. In these spectral assays, the total ultraviolet light present was equivalent; only the spectral characteristics varied. Based on the absorbance spectra of these PAHs, it was predicted that toxicity, quantified using immobilization as the endpoint, would vary significantly among light spectra in pyrene assays, but not in anthracene assays, and that variation in toxicity in fluoranthene assays would be intermediate. The results supported these assumptions. In the pyrene exposures, the glass filter time to 50% population immobilization (IT50) (39.5 min) was 117% longer than the KCr filter IT50 (18.2 min). In the fluoranthene exposures, the glass filter IT50 (49.5 min) was 27% longer than the KCr filter IT50 (39.1 min). In the anthracene exposures, the glass filter IT50 (62.2 min) was not statistically different from the KCr filter IT50 (63.8 min). Comparison of these results with the results of assays conducted under neutral-density filters (that change intensity but not spectral distribution) demonstrate that multiplying spectral intensity by wavelength-specific absorbance accurately predicts relative photoinduced toxicity among the experimental treatments. These results indicate

  19. Seasonal changes and temperature-dependent accumulation of polycyclic aromatic hydrocarbons in high-altitude soils.

    Science.gov (United States)

    Tremolada, Paolo; Parolini, Marco; Binelli, Andrea; Ballabio, Cristiano; Comolli, Roberto; Provini, Alfredo

    2009-07-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are a major group of pollutants whose occurrence in the environment is mainly of anthropogenic origin. In this paper, we examine the effect of topographical slope exposure on PAH contamination and seasonal change in PAH concentrations in soils. We collected soil samples on three dates in 2007 (early May, end of July and beginning of November) from south- and north-facing aspects at 1900 m a.s.l. in the central Italian Alps. We found greater PAH contamination in soils from a north-facing slope than in those from a south-facing slope at all seasons. We calculated North-South Enrichment Factors as the ratio between the concentrations measured in soils from northern and southern aspects. These ratios ranged from 1.4 to 1.9 for lighter PAHs (from 2 to 4 rings). These values are consistent with theoretical calculations based on temperature-specific octanol-air partition coefficients (predicted North-South Enrichment Factors range from 1.6 to 2.0). For heavier PAHs (from 5 to 6 rings), smaller differences were observed between soils from northern and southern aspects, due to the gas/particle distribution of these compounds. We also found consistent differences in normalised PAH concentrations across the three sampling periods. The majority of compounds showed a significant decreasing trend from the beginning of May to the end of July, due to the annual cycles of physical processes (deposition vs. volatilisation) and biological processes (uptake and/or biotransformation). Only a few compounds showed different trends, presumably due to season-specific local emission sources.

  20. Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    L. C. Marr

    2005-12-01

    Full Text Available Understanding sources, concentrations, and transformation of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and assessment of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations typically peak at ~110 ng m−3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

  1. Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    L. C. Marr

    2006-01-01

    Full Text Available Understanding sources, concentrations, and transformations of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and intercomparison of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations of particle-phase PAHs typically peak at ~110 ng m-3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

  2. Bioconcentration of polycyclic aromatic hydrocarbons in roots of three mangrove species in Jiulong River Estuary

    Institute of Scientific and Technical Information of China (English)

    LU Zhi-qiang; ZHENG Wen-jiao; MA Li

    2005-01-01

    The polycyclic aromatic hydrocarbons(PAHs) concentrations were determined in the root of three mangrove species( Kandelia candel, Avicennia marina and Bruguiera gymnorrhiza) and their growing environment(sediment) in mangrove wetlands of Jiulong River Estuary, Fujian, China. The total PAHs(16 parent PAHs) in mangrove sediments ranged from 193.44 to 270.53 ng/g dw, with a mean value of 231.76 ± 31.78 ng/g dw. Compared with other mangrove and coastal marine sediments, the PAHs concentrations of all the sampling areas in this study were at relatively lower level. The total PAHs(13 parent PAHs) values varied from 30.83 to 62.73 ng/g dw in mangrove roots. Benzo[a] pyrene(five-ring), fluoranthene(four-ring) and pyrene(four- ring) dominated in mangrove sediments. Based on ratios of phenathrene/anthracene, fluoranthene/pyrene and fluoranthene/pyrene + fluoranthene, the main possible sources of surface sediment PAHs were identified as grass, wood or coal combustion for mangrove wetlands of Jiulong River Estuary. Naphthalene(two-ring)and phenathrene(three-ring) were the most abundant compounds in mangrove roots. Sediment-to-vegetation bioconcentration factors (BCFsvS) were calculated and their relationships with PAHs' physico-chemical properties were investigated. The average BCFsv s of PAHs for three mangrove species roots were almost all under the level of 1 except for naphthalene. Good linear relationship between BCFsv values for mangrove roots and PAHs water solubility, octanol-water partitioning coefficients was derived in present study. The solubility and the octanol-water partition coefficient were proved to be good predictors for the accumulation of PAHs in mangrove roots,respectively.

  3. Genotoxicity in child populations exposed to Polycyclic Aromatic Hydrocarbons (PAHs in the air from Tabasco, Mexico

    Directory of Open Access Journals (Sweden)

    Aldeco R. Gamboa

    2008-12-01

    Full Text Available The economy of the state of Tabasco is based on oil extraction. However, this imposes major effects to the environment and communities. Examples are the Polycyclic Aromatic Hydrocarbons (PAHs that may be found in the soil, water and sediment of the region. Their volatility makes them available to living beings and results in genotoxic activity. The purpose of this study was to quantify the levels of PAHs in the air at several points in the state, and to analyze their relationship with possible damage to DNA on local inhabitants. Single Cell Gel Electrophoresis Assay (Comet Assay was applied to peripheral blood lymphocytes of five groups of children between six and 15 years of age. PAH samples were analyzed following US/EPA TO-13-A method. Results indicated the presence in the air of most of the 16 PAHs considered as high priority by EPA, some of which have been reported with carcinogenic activity. Differences (p<0.05 were found between PAHs concentration in the gaseous component and in the particulate component of air samples, with the greatest values for the gaseous component. Greatest PAH concentrations were detected in areas with high oil extraction activities. Children groups from high oil activity areas presented genotoxic damage labeled from moderate to high according to DNA migration from nuclei (Tail Length: 14.2 - 42.14 mm and Tail/Head: 0.97 - 2.83 mm compared with control group (12.25 and 0.63 mm, respectively. The group with greatest cell damage was located in the area with the greatest oil activity. We conclude that the presence of PAHs in the air may represent a health risk to populations that are chronically exposed to them at high oil activity regions.

  4. Genotoxicity in child populations exposed to polycyclic aromatic hydrocarbons (PAHs) in the air from Tabasco, Mexico.

    Science.gov (United States)

    Gamboa, Rodríguez T; Gamboa, Aldeco R; Bravo, Alvarez H; Ostrosky, Wegman P

    2008-12-01

    The economy of the state of Tabasco is based on oil extraction. However, this imposes major effects to the environment and communities. Examples are the Polycyclic Aromatic Hydrocarbons (PAHs) that may be found in the soil, water and sediment of the region. Their volatility makes them available to living beings and results in genotoxic activity. The purpose of this study was to quantify the levels of PAHs in the air at several points in the state, and to analyze their relationship with possible damage to DNA on local inhabitants. Single Cell Gel Electrophoresis Assay (Comet Assay) was applied to peripheral blood lymphocytes of five groups of children between six and 15 years of age. PAH samples were analyzed following US/EPA TO-13-A method. Results indicated the presence in the air of most of the 16 PAHs considered as high priority by EPA, some of which have been reported with carcinogenic activity. Differences (p<0.05) were found between PAHs concentration in the gaseous component and in the particulate component of air samples, with the greatest values for the gaseous component. Greatest PAH concentrations were detected in areas with high oil extraction activities. Children groups from high oil activity areas presented genotoxic damage labeled from moderate to high according to DNA migration from nuclei (Tail Length: 14.2 - 42.14 microm and Tail/Head: 0.97 - 2.83 microm) compared with control group (12.25 and 0.63 microm, respectively). The group with greatest cell damage was located in the area with the greatest oil activity. We conclude that the presence of PAHs in the air may represent a health risk to populations that are chronically exposed to them at high oil activity regions.

  5. Impact of oxidation process on polycyclic aromatic hydrocarbon (PAH) content in bitumen.

    Science.gov (United States)

    Bolliet, Christophe; Juery, Catherine; Thiebaut, Benoit

    2013-01-01

    This study investigated the impact of the oxidation process on the concentration of polycyclic aromatic hydrocarbons (PAH) in blown bitumen and identified some key contributing parameters. The U.S. Environmental Protection Agency's PAH list was used for this study. PAHs are considered a good toxicological marker, and measurement of PAHs in bitumen can be performed easily. The results of PAH content in blown bitumen and the corresponding feedstock was determined from the limit of detection up to 120 mg/kg for 24 samples. Compared to PAH levels in coal tar pitch, PAH levels in bitumen are very low. Measurements were performed by three laboratories using different methods to allow robust conclusions. The results highlight the difficulties in measuring PAHs in bitumen with accuracy for values below 30 mg/kg; therefore the discussion is based on summary statistics by adding concentrations of PAHs with common ring sizes. Incorporation of flux oil in the feed of the blowing bitumen unit tends to increase PAH content in feed stock and in blown bitumen, particularly the 4- to 6-ring PAHs, which are the most carcinogenic as identified by an animal skin painting test. The amount of PAH content from blown bitumen with flux oil can be at least three times higher than the amount in blown bitumen without flux oil, depending on the quality and quantity of the flux oil used. This study shows that the blowing process does not produce PAHs in bitumen. Conversely, it appears to reduce them in the final product. Close to 10 to 30% of PAHs are probably stripped from the liquid phase of bitumen during the blowing operation.

  6. Simple and rapid extraction of polycyclic aromatic hydrocarbons collected on polyurethane foam adsorbent

    Science.gov (United States)

    Maddalena, Randy L.; McKone, Thomas E.; Kado, Norman Y.

    A single-pass flow through extraction (FTE) method for polycyclic aromatic hydrocarbons (PAHs) that have been collected on poly-ether type polyurethane foam (PUF) is described and demonstrated. The method is based on the principles of trace enrichment and solid-phase extraction where the analyte of interest is collected or concentrated on the expanded PUF matrix. Following collection, the PUF is compressed to reduce the solvent requirement and a single-pass gravity fed mobile-phase extraction is used to remove the analyte. Two extraction mobile phases were tested (dichloromethane, DCM and a 10% (V:V) mixture of acetone in hexane, AH). We obtained quantitative recoveries of 18 PAHs from 115 cm 3 PUF plugs with less than 4 ml of DCM or 6 ml of AH. Average standard recoveries of 18 spiked PAHs were 97% and 104% for the DCM and the AH extractions, respectively. The semi-volatile fraction of PAHs in an environmental sample of a complex mixture (diesel exhaust) were also quantitatively extracted using the FTE method. Finally, the FTE method was used to extract samples collected from an exposure chamber that was designed to measure the transfer of semi-volatile atmospheric pollutants into vegetation. Total variance reported as percent relative standard deviation in the measured steady-state atmospheric concentrations of pyrene, fluoranthene, anthracene and phenanthrene were 3.4, 10.5, 8.5 and 4.4%, respectively, thus demonstrating the excellent precision of the method. The FTE method is simple, fast and effective for extracting PAH that has been collected on PUF adsorbent.

  7. Interactions between zooplankton and crude oil: toxic effects and bioaccumulation of polycyclic aromatic hydrocarbons.

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeda

    Full Text Available We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1 the effects of crude oil (Louisiana light sweet oil on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs in mesozooplankton communities, (2 the lethal effects of dispersant (Corexit 9500A and dispersant-treated oil on mesozooplankton, (3 the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4 the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 µl L(-1 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1∶20, dispersant (0.25 µl L(-1 and dispersant-treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 µl L(-1 to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments.

  8. Firefighting instructors' exposures to polycyclic aromatic hydrocarbons during live fire training scenarios.

    Science.gov (United States)

    Kirk, Katherine M; Logan, Michael B

    2015-01-01

    Cumulative exposures of firefighting instructors to toxic contaminants generated from live-fire training potentially far exceed firefighter exposures arising from operational fires. This study measured the atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) outside and inside the structural firefighting ensembles worn by instructors during five live fire training evolutions. In addition, the contamination of ensembles by deposition of PAHs was characterized. Concentrations of polycyclic aromatic hydrocarbons outside the instructors' structural firefighting ensembles during the training evolutions ranged from 430 μg/m(3) to 2700 μg/m(3), and inside the structural firefighting ensembles from 32 μg/m(3) to 355 μg/m(3). Naphthalene, phenanthrene and acenaphthylene dominated the PAHs generated in the live fire evolutions, but benzo[a]pyrene was the greatest contributor to the toxicity of the PAH mixture both inside and outside the structural firefighting ensembles. Deposition of PAHs onto the structural firefighting ensembles was measured at between 69 and 290 ng/cm(2), with phenanthrene, fluoranthene, pyrene, and benzo[a]anthracene detected on all samples. These findings suggest that firefighting instructor exposures to PAHs during a single live-fire training evolution are comparable with exposures occurring in industrial settings over a full shift. Further research is required to investigate the importance of various potential routes of exposure to PAHs as a result of ingress and deposition of PAHs in/on structural firefighting ensembles.

  9. Questioning the existence of superconducting potassium doped phases for aromatic hydrocarbons

    Science.gov (United States)

    Heguri, Satoshi; Kobayashi, Mototada; Tanigaki, Katsumi

    2015-07-01

    Superconductivity in aromatic hydrocarbons doped with potassium (K) such as K3 [picene (PCN)] and K3 [phenanthrene (PHN)] is found for only armchair-type polycyclic aromatic hydrocarbon. In this paper the thermodynamics of the reaction processes of PHN or anthracene (AN, zigzag type) with K was studied using differential scanning calorimetry and x-ray diffraction. We show that PHN decomposes during the reaction, triggered by hydrogen abstraction, to give metal hydride KH and unknown amorphous. No stable doped phases exist in Kx(PHN ) with stoichiometries of x =1 -3 . However, in the case of AN, a stable doped phase forms. We claim that PHN, which has been reported to be energetically more stable in the ground state than AN by first principle calculations, is unstable upon doping. We also suggest that the superconductivity in K3(PCN ) is due to the misinterpretation of experimental data, which actually arises from ferromagnetic impurities. We have never detected the superconductivity above 2 K in these compounds. The superconductivity in both Kx(PHN ) and Kx(PCN ) is concluded to be highly questionable.

  10. Studies of biomarkers in aluminum workers occupationally exposed to polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Ovrebø, S; Haugen, A; Hemminki, K; Szyfter, K; Drabløs, P A; Skogland, M

    1995-01-01

    Evaluation of biomarkers for genotoxic exposure are important for future use of such biomarkers in cancer prevention. We have studied a group of aluminum plant workers for a period of 2.5 years. The level of polycyclic aromatic hydrocarbons (PAHs) has been monitored at the work place (cathode relining). During the study period, urine and blood were sampled up to seven times from the same workers. Mean level of urinary 1-hydroxypyrene varied from 1.08 to 2.44 mumol/mol creatinine in the exposed groups compared with 0.36 and 0.20 mumol/mol creatinine in the two reference groups. For a group of 14 workers the intraindividual variation of urinary 1-hydroxypyrene was analyzed. The relative standard deviation of the values was < or = 0.50 for half of the workers; the relative standard deviation was calculated for individual values divided by mean of each time point. Polycyclic aromatic hydrocarbon-DNA adducts in white blood cells from exposed and nonexposed workers were measured by both immunoassay and 32P-postlabeling. By 32P-postlabeling mean values of 12.0 adducts/10(8) and 10.8 adducts/10(8) nucleotides were found in a PAH-exposed group and a reference group, respectively. Intraindividual variation of PAH-DNA adducts was also analyzed.

  11. Polycyclic Aromatic Hydrocarbons (PAHs) in urban atmospheric particulate of NCR, Delhi, India

    Science.gov (United States)

    Sonwani, Saurabh; Amreen, Hassan; Khillare, P. S.

    2016-07-01

    The present study identifies the particulate Polycyclic Aromatic hydrocarbons (PAHs) and their sources in ambient atmosphere of Delhi, India. PM10 (aerodynamic diameter, ≤10 μm) samples were collected weekly at two residential areas from July 2013 to January 2014. First sampling site was located in centre of the city, while other was at city's background (located in South-East direction of the Delhi). PM10 was collected on Whatman GF/A (8"x10") glass fibre filters using High-Volume sampler having a constant flow rate of 1.10 m3/min. A total of 55 samples, 27 from city centre and 28 from background site were collected during sampling period, covering two different seasons. The samples were analysed for determination of 16 Polycyclic Aromatic Hydrocarbons by using High Performance Liquid Chromatography (HPLC) system (Waters, USA). A source apportionment study using Molecular Diagnostic Ratio (MDR) and Principal Component Analysis (PCA) were conducted for both sampling sites in order to identify the potential PAHs sources in Delhi. MDR was used for the preliminary identification of sources and PCA was used for further confirmation of the PAH sources at both the sites in Delhi. Results indicated towards traffic and coal combustion related sources as dominant contributors of urban atmospheric PAHs in Delhi.

  12. Biomarker sensitivity for polynuclear and halogenated aromatic hydrocarbon contamination in fish species from Galveston Bay

    Energy Technology Data Exchange (ETDEWEB)

    Willett, K.; McDonald, S.; Steinberg, M.; Beatty, K.; Safe, S. [Texas A and M Univ., College Station, TX (United States)

    1995-12-31

    The Galveston Bay estuary exhibits a contamination gradient for polynuclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons, which is useful for comparing biomarker response sensitivity in fish taken from different bay locations. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), were collected from four stations where sediment total PAHs ranged from 68 to > 1,000 ng/g. Hardhead catfish showed no consistent CYP1A mediated responses (hepatic ethoxyresorufin-O-deethylase activity (EROD), CYP1A mRNA levels, or CYP1A immunoreactive protein) in the field collected fish or in fish dosed with up to 15 mg/kg benzo(a)pyrene (BaP). Significant differences were seen in field collected hardhead catfish in biliary concentrations of naphthalene, phenanthrene, and BaP metabolites. Conversely, in croakers taken from the same four Galveston Bay locations, there were significant elevations IN EROD and glutathione-S-transferase activities, CYP1A immunoreactive protein, and biliary PAH metabolites at the contaminated stations. These studies suggest that croaker is a good monitoring species especially with respect to induction of CYP1A mediated responses by PAHs. Biliary PAH metabolites and PAH-DNA adducts were sensitive to PAH contamination in both species.

  13. City air pollution of polycyclic aromatic hydrocarbons and other mutagens: occurrence, sources and health effects

    DEFF Research Database (Denmark)

    Nielsen, T.; Ejsing Jørgensen, Hans; Larsen, J.C.

    1996-01-01

    The presence of polycyclic aromatic hydrocarbons (PAH), mutagens and other air pollutants was investigated in a busy street in central Copenhagen and in a park area adjacent to the street. The winter concentration of benzo(a)pyrene was 4.4+/-1.2 ng/m(3) in the street air and 1.4+/-0.6 ng/m(3) in ...... was estimated to be 40%. Four different approaches to evaluate the health effects are discussed. The direct effect of PAH air pollution, and other mutagens, is considered to be a maximum of five lung cancer cases each year out of one million people.......The presence of polycyclic aromatic hydrocarbons (PAH), mutagens and other air pollutants was investigated in a busy street in central Copenhagen and in a park area adjacent to the street. The winter concentration of benzo(a)pyrene was 4.4+/-1.2 ng/m(3) in the street air and 1.4+/-0.6 ng/m(3......) in the city park. The atmospheric concentrations of PAH decreased in the order of: street > city background air similar to suburbs > village > open land. The traffic contribution of PAH to street air was estimated to be 90% on working days and 60% during weekends and its contribution to city background air...

  14. Mortality from obstructive lung diseases and exposure to polycyclic aromatic hydrocarbons among asphalt workers

    Energy Technology Data Exchange (ETDEWEB)

    Burstyn, I.; Boffetta, P.; Heederik, D.; Partanen, T.; Kromhout, H.; Svane, O.; Langard, S.; Frentzel-Beyme, R.; Kauppinen, T.; Stucker, I.; Shaham, J.; Ahrens, W.; Cenee, S.; Ferro, G.; Heikkila, P.; Hooiveld, M.; Johansen, C.; Randem, B.G.; Schill, W. [University of Utrecht, Utrecht (Netherlands)

    2003-09-01

    Work in the asphalt industry has been associated with nonmalignant respiratory morbidity and mortality, but the evidence is not consistent. A historical cohort of asphalt workers included 58,862 men (911,209 person-years) first employed between 1913 and 1999 in companies applying and mixing asphalt in Denmark, Finland, France, Germany, Israel, the Netherlands, and Norway. The relations between mortality from nonmalignant respiratory diseases (including the obstructive lung diseases: chronic bronchitis, emphysema, and asthma) and specific chemical agents and mixtures were evaluated using a study-specific exposure matrix. Mortality from obstructive lung diseases was associated with the estimated cumulative and average exposures to polycyclic aromatic hydrocarbons and coal tar (p values of the test for linear trend=0.06 and 0.01, respectively). The positive association between bitumen fume exposure and mortality from obstructive lung diseases was weak and not statistically significant; confounding by simultaneous exposure to coal tar could not be excluded. The authors lacked data on smoking and full occupational histories. In conclusion, exposures to polycyclic aromatic hydrocarbons, originating from coal tar and possibly from bitumen fume, may have contributed to mortality from obstructive lung diseases among asphalt workers, but confounding and bias cannot be ruled out as an explanation for the observed associations.

  15. 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.

  16. Polycyclic aromatic hydrocarbons in Recent lake sediments—I. Compounds having anthropogenic origins

    Science.gov (United States)

    Wakeham, Stuart G.; Schaffner, Christian; Giger, Walter

    1980-03-01

    Polycyclic aromatic hydrocarbons (PAH) in sediment cores from Lake Lucerne, Lake Zürich, and Greifensee, Switzerland, and Lake Washington, northwest U.S.A., have been isolated, identified and quantified by glass capillary gas chromatography and gas chromatography/mass spectrometry. Surface sediment layers are greatly enriched in PAH—up to 40 times—compared to deeper layers. In addition, concentration increases in upper sediments generally correspond to increasing industrialization and urbanization in the catchment basins of the lakes. Few PAH could be detected in pre-industrial revolution sediments, indicating that background levels for most PAH in aquatic sediments are extremely low. These results are consistent with an anthropogenic source for most of the aromatic hydrocarbons present in the modern sediments. A comparison of PAH distributions in the sediments and in possible source materials shows that urban runoff of street dust may be the most important PAH input to these lacustrine sediments. There is evidence that a significant contribution to the PAH content of street dust comes from material associated with asphalt.

  17. Oxidation of polycyclic aromatic hydrocarbons using partially purified laccase from residual compost of agaricus bisporus

    Energy Technology Data Exchange (ETDEWEB)

    Mayolo-Deloisa, K. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Machin-Ramirez, C. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Faculty of Chemical Sciences and Engineering, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Rito-Palomares, M. [Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Trejo-Hernandez, M.R. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico)

    2011-08-15

    Laccase partially purified from residual compost of Agaricus bisporus by an aqueous two-phase system (Lac ATPS) was used in degrading polycyclic aromatic hydrocarbons: fluorene (Flu), phenanthrene (Phe), anthracene (Ant), benzo[a]pyrene (BaP), and benzo[a]anthracene (BaA). The capacity of the enzyme to oxidize polyaromatic compounds was compared to that of the crude laccase extract (CE). After treatment of 72 h, Lac ATPS and CE were not capable of oxidizing Flu and Phe, while Ant, BaP, and BaA were oxidized, resulting in percentages of oxidation of 11.2 {+-} 1, 26 {+-} 2, and 11.7 {+-} 4 % with CE, respectively. When Lac ATPS was used, the following percentages of oxidation were obtained: 11.4 {+-} 3 % for Ant, 34 {+-} 0.1 % for BaP, and 13.6 {+-} 2 % for BaA. The results reported here demonstrate the potential application of Lac ATPS for the oxidation of polycyclic aromatic hydrocarbons. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Characteristics of polycyclic aromatic hydrocarbon emissions of particles of various sizes from smoldering incense.

    Science.gov (United States)

    Yang, T T; Lin, T S; Wu, J J; Jhuang, F J

    2012-02-01

    Release of polycyclic aromatic hydrocarbons (PAHs) in particles of various sizes from smoldering incenses was determined. Among the three types of incense investigated, yielding the total PAH emission rate and factor ranges for PM0.25 were 2,139.7-6,595.6 ng/h and 1,762.2-8,094.9 ng/g, respectively. The PM0.25/PM2.5 ratio of total PAH emission factors and rates from smoldering three incenses was greater than 0.92. This study shows that total particle PAH emission rates and factors were mainly incenses. The benzo[a]pyrene accounted for 65.2%-68.0% of the total toxic equivalency emission factor of PM2.5 for the three incenses. Experimental results clearly indicate that the PAH emission rates and factors were influenced significantly by incense composition, including carbon and hydrogen content. The study concludes that smoldering incense with low atomic hydrogen/carbon ratios minimized the production of total polycyclic aromatic hydrocarbons of both PM2.5 and PM0.25.

  19. Evaluation of methods for predicting the toxicity of polycyclic aromatic hydrocarbon mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, W.; Barhoumi, R.; Burghardt, R.C. [and others] [Texas A & M University, College Station, TX (USA). Dept. of Veterinary Anatomy and Public Health and Department of Civil Engineering

    2001-04-15

    Risk assessments of polycyclic aromatic hydrocarbon mixtures are hindered by a lack of reliable information on the potency of both mixtures and their individual components. This paper examines methods for approximating the toxicity of polycyclic aromatic hydrocarbon (PAH) mixtures. PAHs were isolated from a coal tar and then separated by ring number using HPLC. Five fractions (A-E) were generated, each possessing a unique composition and expected potency. The toxicity of each fraction was measured in the Salmonella/mutagenicity assay and the Chick Embryo Screening Test (CHEST). Their abilities to induce ethoxyresorufin-O-deethylase and to inhibit gap junction intercellular communication in rat liver Clone 9 cells were also measured. In the Salmonella/mutagenicity assay, fractions were predicted to have potencies in the order C {gt} E {gt} B {gt} A. Toxic equivalency factors (TEFs) for fractions A-E were in the order E {ge} D {gt} C {gt} B {gt} A. TEF values were 20 652, 20 929, 441, 306 and 74.1 {mu}g of BaP equiv/g, respectively. A lack of agreement between assay-predicted potencies and chemical analysis-predicted potencies was observed with other assays and other methods of calculation. The results demonstrate the limitations of using a single method to predict the toxicity of a complex PAH mixture. 41 refs., 2 figs., 3 tabs.

  20. 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.

  1. 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.)

  2. 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. 

  3. Fate of Soil Organic Carbon and Polycyclic Aromatic Hydrocarbons in a Vineyard Soil Treated with Biochar.

    Science.gov (United States)

    Rombolà, Alessandro G; Meredith, Will; Snape, Colin E; Baronti, Silvia; Genesio, Lorenzo; Vaccari, Francesco Primo; Miglietta, Franco; Fabbri, Daniele

    2015-09-15

    The effect of biochar addition on the levels of black carbon (BC) and polcyclic aromatic hydrocarbons (PAHs) in a vineyard soil in central Italy was investigated within a two year period. Hydropyrolysis (HyPy) was used to determine the contents of BC (BCHyPy) in the amended and control soils, while the hydrocarbon composition of the semi-labile (non-BCHyPy) fraction released by HyPy was determined by gas chromatography-mass spectrometry, together with the solvent-extractable PAHs. The concentrations of these three polycyclic aromatic carbon reservoirs changed and impacted differently the soil organic carbon over the period of the trial. The addition of biochar (33 ton dry biochar ha(-1)) gave rise to a sharp increase in soil organic carbon, which could be accounted for by an increase in BCHyPy. Over time, the concentration of BCHyPy decreased significantly from 36 to 23 mg g(-1) and as a carbon percentage from 79% to 61%. No clear time trends were observed for the non-BCHyPy PAHs varying from 39 to 34 μg g(-1) in treated soils, not significantly different from control soils. However, the concentrations of extractable PAHs increased markedly in the amended soils and decreased with time from 153 to 78 ng g(-1) remaining always higher than those in untreated soil. The extent of the BCHyPy loss was more compatible with physical rather than chemical processes.

  4. Evaluation of Polycyclic Aromatic Hydrocarbons Using Analytical Methods, Toxicology, and Risk Assessment Research: Seafood Safety after a Petroleum Spill as an Example

    OpenAIRE

    Wickliffe, Jeffrey; Overton, Edward; Frickel, Scott; Howard, Jessi; Wilson, Mark; Simon, Bridget; Echsner, Stephen; Nguyen, Daniel; Gauthe, David; Blake, Diane; Miller, Charles; Elferink, Cornelis; Ansari, Shakeel; Fernando, Harshica; Trapido, Edward

    2013-01-01

    Background: Polycyclic aromatic hydrocarbons (PAHs) are abundant and widespread environmental chemicals. They are produced naturally and through man-made processes, and they are common in organic media, including petroleum. Several PAHs are toxic, and a subset exhibit carcinogenic activity. PAHs represent a range of chemical structures based on two or more benzene rings and, depending on their source, can exhibit a variety of side modifications resulting from oxygenation, nitrogenation, and a...

  5. Importance of fundamental sp, sp2, and sp3 hydrocarbon radicals in the growth of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Shukla, Bikau; Koshi, Mitsuo

    2012-06-05

    The most basic chemistry of products formation in hydrocarbons pyrolysis has been explored via a comparative experimental study on the roles of fundamental sp, sp(2), and sp(3) hydrocarbon radicals/intermediates such as ethyne/ethynyl (C(2)H(2)/C(2)H), ethene/ethenyl (C(2)H(4)/C(2)H(3)), and methane/methyl (CH(4)/CH(3)) in products formations. By using an in situ time-of-flight mass spectrometry technique, gas-phase products of pyrolysis of acetylene (ethyne, C(2)H(2)), ethylene (ethene, C(2)H(4)), and acetone (propanone, CH(3)COCH(3)) were detected and found to include small aliphatic products to large polycyclic aromatic hydrocarbons (PAHs) of mass 324 amu. Observed products mass spectra showed a remarkable sequence of mass peaks at regular mass number intervals of 24, 26, or 14 indicating the role of the particular corresponding radicals, ethynyl (C(2)H), ethenyl (C(2)H(3)), or methyl (CH(3)), in products formation. The analysis of results revealed the following: (a) product formation in hydrocarbon pyrolysis is dominated by hydrogen abstraction and a vinyl (ethenyl, C(2)H(3)) radical addition (HAVA) mechanism, (b) contrary to the existing concept of termination of products mass growth at cyclopenta fused species like acenaphthylene, novel pathways forming large PAHs were found succeeding beyond such cyclopenta fused species by the further addition of C(2)H(x) or CH(3) radicals, (c) production of cyclopenta ring-fused PAHs (CP-PAHs) such as fluoranthene/corannulene appeared as a preferred route over benzenoid species like pyrene/coronene, (d) because of the high reactivity of the CH(3) radical, it readily converts unbranched products into products with aliphatic chains (branched product), and (e) some interesting novel products such as dicarbon monoxide (C(2)O), tricarbon monoxide (C(3)O), and cyclic ketones were detected especially in acetone pyrolysis. These results finally suggest that existing kinetic models of product formation should be modified to include

  6. 食品中多环芳烃的研究进展%Progress in polycyclic aromatic hydrocarbons in food

    Institute of Scientific and Technical Information of China (English)

    李翠翠; 马宇翔; 陆启玉

    2015-01-01

    The progress in research on the formation mechanism,analytical methods and control measures about polycyclic aromatic hydrocarbons in food was summarized,in order to provide references for solving pollution problems caused by polycyclic aromatic hydrocarbons in food.%简述了近年来关于食品中多环芳烃的形成机理、分析方法及控制措施的研究进展,以期为解决食品中多环芳烃的污染问题提供依据。

  7. 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.

  8. 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.

  9. Conversion of methanol to hydrocarbons over ZSM-5 zeolite: an examination of the role of aromatic hydrocarbons using /sup 13/carbon and deuterium-labeled feeds

    Energy Technology Data Exchange (ETDEWEB)

    Mole, T.; Bett, G.; Seddon, D.

    1983-12-01

    A mechanism is suggested for the acceleration by aromatic hydrocarbons of zeolite-catalyzed methanol conversion. According to this mechanism, the aromatic hydrocarbon undergoes successive ring methylation, prototropic conversion to an exo-methylene-cyclohexadiene, side-chain methylation, and ring de-ethylation. The overall result is that two methanol molecules give an ethylene molecule. The mechanism is supported by various reactions observed over ZSM-5 catalyst at methanol conversion temperatures: (I) deuteration of p-xylene by D/sub 2/O in the ring and methyl positions; (II) de-alkylation of p-ethyltoluene and n-propylbenzene; and (III) incorporation of the aromatic carbon of benzenes and alkylbenzenes into ethylene product, as revealed by /sup 13/C-labeling studies. 3 tables.

  10. Biodegradation of polycyclic aromatic hydrocarbons by Trichoderma species: a mini review.

    Science.gov (United States)

    Zafra, German; Cortés-Espinosa, Diana V

    2015-12-01

    Fungi belonging to Trichoderma genus are ascomycetes found in soils worldwide. Trichoderma has been studied in relation to diverse biotechnological applications and are known as successful colonizers of their common habitats. Members of this genus have been well described as effective biocontrol organisms through the production of secondary metabolites with potential applications as new antibiotics. Even though members of Trichoderma are commonly used for the commercial production of lytic enzymes, as a biological control agent, and also in the food industry, their use in xenobiotic biodegradation is limited. Trichoderma stands out as a genus with a great range of substrate utilization, a high production of antimicrobial compounds, and its ability for environmental opportunism. In this review, we focused on the recent advances in the research of Trichoderma species as potent and efficient aromatic hydrocarbon-degrading organisms, as well as aimed to provide insight into its potential role in the bioremediation of soils contaminated with heavy hydrocarbons. Several Trichoderma species are associated with the ability to metabolize a variety of both high and low molecular weight polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, chrysene, pyrene, and benzo[a]pyrene. PAH-degrading species include Trichoderma hamatum, Trichoderma harzianum, Trichoderma reesei, Trichoderma koningii, Trichoderma viride, Trichoderma virens, and Trichoderma asperellum using alternate enzyme systems commonly seen in other organisms, such as multicooper laccases, peroxidases, and ring-cleavage dioxygenases. Within these species, T. asperellum stands out as a versatile organism with remarkable degrading abilities, high tolerance, and a remarkable potential to be used as a remediation agent in polluted soils.

  11. Comparison of three different in vitro mutation assays used for the investigation of cytochrome P450-mediated mutagenicity of nitro-polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Kappers, W.A.; Och, F.M.M. van; Groene, E.M. de; Horbach, G.J.

    2000-01-01

    Three different in vitro mutation assays were used to investigate the involvement of cytochrome P450 enzymes in the activation of the nitro- polycyclic aromatic hydrocarbons (nitroPAHs) 1-nitropyrene and 2- nitrofluorene and their reduced metabolites amino-polycyclic aromatic hydrocarbons (aminoPAHs

  12. 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 (< LOQ) to 2.1 × 103 ng L-1. The concentrations of PCBs and CPs in rainwater were < LOQ. ∑ PCB and ∑ CP concentrations in air ranged from < LOQ to 44.6 and < LOQ to 351.7 pg m-3, respectively. The potential relationships between PAH wet scavenging and particulate matter and rainwater properties were investigated. The concentrations of ionic species in particulate matter and rainwater were significantly correlated, highlighting the importance of particle scavenging process. Overall, higher scavenging efficiencies were found for relatively less volatile PAHs, underlining the effect of analyte 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.

  13. Polycyclic aromatic hydrocarbons produced by electrocautery smoke and the use of personal protective equipment 1

    Science.gov (United States)

    Claudio, Caroline Vieira; Ribeiro, Renata Perfeito; Martins, Júlia Trevisan; Marziale, Maria Helena Palucci; Solci, Maria Cristina; Dalmas, José Carlos

    2017-01-01

    ABSTRACT Objective: analyze the concentration of polycyclic aromatic hydrocarbons in electrocautery smoke in operating rooms and the use of personal protective equipment by the intraoperative team when exposed to hydrocarbons. Method: exploratory and cross-sectional field research conducted in a surgery center. Gases were collected by a vacuum suction pump from a sample of 50 abdominal surgeries in which an electrocautery was used. A form was applied to identify the use of personal protective equipment. Gases were analyzed using chromatography. Descriptive statistics and Spearman's test were used to treat data. Results: there were 17 (34%) cholecystectomies with an average duration of 136 minutes, while the average time of electrocautery usage was 3.6 minutes. Airborne hydrocarbons were detected in operating rooms in 100% of the surgeries. Naphthalene was detected in 48 (96.0%) surgeries and phenanthrene in 49 (98.0%). The average concentration of these compounds was 0.0061 mg/m3 and a strong correlation (0.761) was found between them. The intraoperative teams did not use respirator masks such as the N95. Conclusion: electrocautery smoke produces gases that are harmful to the health of the intraoperative team, which is a concern considering the low adherence to the use of personal protective equipment. PMID:28301033

  14. A strategy for aromatic hydrocarbon bioremediation under anaerobic conditions and the impacts of ethanol: A microcosm study

    Science.gov (United States)

    Chen, Yu Dao; Barker, James F.; Gui, Lai

    2008-02-01

    Increased use of ethanol-blended gasoline (gasohol) and its potential release into the subsurface have spurred interest in studying the biodegradation of and interactions between ethanol and gasoline components such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) in groundwater plumes. The preferred substrate status and the high biological oxygen demand (BOD) posed by ethanol and its biodegradation products suggests that anaerobic electron acceptors (EAs) will be required to support in situ bioremediation of BTEX. To develop a strategy for aromatic hydrocarbon bioremediation and to understand the impacts of ethanol on BTEX biodegradation under strictly anaerobic conditions, a microcosm experiment was conducted using pristine aquifer sand and groundwater obtained from Canadian Forces Base Borden, Canada. The initial electron accepter pool included nitrate, sulfate and/or ferric iron. The microcosms typically contained 400 g of sediment, 600˜800 ml of groundwater, and with differing EAs added, and were run under anaerobic conditions. Ethanol was added to some at concentrations of 500 and 5000 mg/L. Trends for biodegradation of aromatic hydrocarbons for the Borden aquifer material were first developed in the absence of ethanol, The results showed that indigenous microorganisms could degrade all aromatic hydrocarbons (BTEX and trimethylbenzene isomers-TMB) under nitrate- and ferric iron-combined conditions, but not under sulfate-reducing conditions. Toluene, ethylbenzene and m/p-xylene were biodegraded under denitrifying conditions. However, the persistence of benzene indicated that enhancing denitrification alone was insufficient. Both benzene and o-xylene biodegraded significantly under iron-reducing conditions, but only after denitrification had removed other aromatics. For the trimethylbenzene isomers, 1,3,5-TMB biodegradation was found under denitrifying and then iron-reducing conditions. Biodegradation of 1,2,3-TMB or 1,2,4-TMB was slower under iron

  15. A magnetic-based dispersive micro-solid-phase extraction method using the metal-organic framework HKUST-1 and ultra-high-performance liquid chromatography with fluorescence detection for determining polycyclic aromatic hydrocarbons in waters and fruit tea infusions.

    Science.gov (United States)

    Rocío-Bautista, Priscilla; Pino, Verónica; Ayala, Juan H; Pasán, Jorge; Ruiz-Pérez, Catalina; Afonso, Ana M

    2016-03-04

    A hybrid material composed by the metal-organic framework (MOF) HKUST-1 and Fe3O4 magnetic nanoparticles (MNPs) has been synthetized in a quite simple manner, characterized, and used in a magnetic-assisted dispersive micro-solid-phase extraction (M-d-μSPE) method in combination with ultra-high-performance liquid chromatography (UHPLC) and fluorescence detection (FD). The application was devoted to the determination of 8 heavy polycyclic aromatic hydrocarbons (PAHs) in different aqueous samples, specifically tap water, wastewaters, and fruit tea infusion samples. The overall M-d-μSPE-UHPLC-FD method was optimized and validated. The method is characterized by: its simplicity in both the preparation of the hybrid material (simple mixing) and the magnetic-assisted approach (∼10min extraction time), the use of low sorbent amounts (20mg of HKUST-1 and 5mg of Fe3O4 MNPs), and the low organic solvent consumption in the overall M-d-μSPE-UHPLC-FD method (1.5mL of acetonitrile in the M-d-μSPE method and 2.8mL of acetonitrile in the UHPLC-FD run). The resulting method has high sensitivity, with LODs down to 0.8ngL(-1); adequate intermediate precision, with relative standard deviation values (RSD) always lower than 6.3% (being the range 5.9-9.0% in tap water for a spiked level of 45ngL(-1), 6.1-14% in wastewaters for a spiked level of 45ngL(-1), and 7.2-17% in fruit tea infusion samples for a spiked level of 45ngL(-1)); and adequate relative recoveries, with average values of 82% in tap water, and 94% and 75% in wastewater and fruit tea infusion samples, respectively, if using the proper matrix-matched calibration.

  16. Exposure to polycyclic aromatic hydrocarbons (PAHs) and bladder cancer: evaluation from a gene-environment perspective in a hospital-based case-control study in the Canary Islands (Spain)

    Science.gov (United States)

    Boada, Luis D; Henríquez-Hernández, Luis A; Navarro, Patricio; Zumbado, Manuel; Almeida-González, Maira; Camacho, María; Álvarez-León, Eva E; Valencia-Santana, Jorge A; Luzardo, Octavio P

    2015-01-01

    Background: Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to bladder cancer. Objective: To evaluate the role of PAHs in bladder cancer, PAHs serum levels were measured in patients and controls from a case-control study. Methods: A total of 140 bladder cancer patients and 206 healthy controls were included in the study. Sixteen PAHs were analyzed from the serum of subjects by gas chromatography–mass spectrometry. Results: Serum PAHs did not appear to be related to bladder cancer risk, although the profile of contamination by PAHs was different between patients and controls: pyrene (Pyr) was solely detected in controls and chrysene (Chry) was exclusively detected in the cases. Phenanthrene (Phe) serum levels were inversely associated with bladder cancer (OR = 0·79, 95%CI = 0·64–0·99, P = 0·030), although this effect disappeared when the allelic distribution of glutathione-S-transferase polymorphisms of the population was introduced into the model (multinomial logistic regression test, P = 0·933). Smoking (OR = 3·62, 95%CI = 1·93–6·79, P<0·0001) and coffee consumption (OR = 1·73, 95%CI = 1·04–2·86, P = 0·033) were relevant risk factors for bladder cancer. Conclusions: Specific PAH mixtures may play a relevant role in bladder cancer, although such effect seems to be highly modulated by polymorphisms in genes encoding xenobiotic-metabolizing enzymes. PMID:25291984

  17. LLE data for the ionic liquid 3-methyl-N-butyl pyridinium dicyanamide with several aromatic and aliphatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hansmeier, Antje R., E-mail: a.hansmeier@tue.n [Chair of Process Systems Engineering (SPS), Technical University of Eindhoven, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Jongmans, Mark; Wytze Meindersma, G.; Haan, Andre B. de [Chair of Process Systems Engineering (SPS), Technical University of Eindhoven, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2010-04-15

    (Liquid + liquid) equilibrium data for ternary systems of several aromatic and aliphatic hydrocarbons with the ionic liquid 3-methyl-N-butylpyridinium dicyanamide were determined at T = 303.15 K and 328.15 K and atmospheric pressure. As aromatics benzene, cumene and p-xylene have been chosen, as paraffins n-hexane and n-nonane were used. The experimental data were regressed and could be adequately correlated with the NRTL model. A logical order in the extraction capacity of 3-methyl-N-butylpyridinium dicyanamide for the different aromatics is obtained: benzene > p-xylene > cumene.

  18. Atmospheric photochemistry of aromatic hydrocarbons: OH budgets during SAPHIR chamber experiments

    Science.gov (United States)

    Nehr, S.; Bohn, B.; Dorn, H.-P.; Fuchs, H.; Häseler, R.; Hofzumahaus, A.; Li, X.; Rohrer, F.; Tillmann, R.; Wahner, A.

    2014-07-01

    Current photochemical models developed to simulate the atmospheric degradation of aromatic hydrocarbons tend to underestimate OH radical concentrations. In order to analyse OH budgets, we performed experiments with benzene, toluene, p-xylene and 1,3,5-trimethylbenzene in the atmosphere simulation chamber SAPHIR. Experiments were conducted under low-NO conditions (typically 0.1-0.2 ppb) and high-NO conditions (typically 7-8 ppb), and starting concentrations of 6-250 ppb of aromatics, dependent on OH rate constants. For the OH budget analysis a steady-state approach was applied in which OH production and destruction rates (POH and DOH) have to be equal. The POH were determined from measurements of HO2, NO, HONO, and O3 concentrations, considering OH formation by photolysis and recycling from HO2. The DOH were calculated from measurements of the OH concentrations and total OH reactivities. The OH budgets were determined from DOH/POH ratios. The accuracy and reproducibility of the approach were assessed in several experiments using CO as a reference compound where an average ratio DOH/POH = 1.13 ± 0.19 was obtained. In experiments with aromatics, these ratios ranged within 1.1-1.6 under low-NO conditions and 0.9-1.2 under high-NO conditions. The results indicate that OH budgets during photo-oxidation experiments with aromatics are balanced within experimental accuracies. Inclusion of a further, recently proposed OH production via HO2 + RO2 reactions led to improvements under low-NO conditions but the differences were small and insignificant within the experimental errors.

  19. [Characterization of aromatic hydrocarbons in heavy gas oil using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry].

    Science.gov (United States)

    Guo, Kun; Zhou, Jian; Liu, Zelong

    2012-02-01

    An analytical method for separating and identifying the aromatic hydrocarbons in heavy gas oil using comprehensive two-dimensional gas chromatography (GC x GC) coupled to time-of-flight mass spectrometry (TOF MS) was established. The two-dimensional distribution by ring number of the aromatic hydrocarbons was obtained. Besides phenanthrene and methyl-phenanthrene, many other polycyclic aromatic hydrocarbons (PAHs) such as pyrene and benzo [a] anthracene were identified by using the retention times, standard mass spectra or literature reports. The method was successfully applied to the hydrotreating process of heavy gas oil and the hydrotreated products of phenanthrene, pyrene were identified. This method provided technical support for the characterization of aromatic hydrocarbons in heavy gas oil and the investigation of hydrogenation mechanism of polycyclic aromatic hydrocarbons. Compared with the conventional method, gas chromatography coupled to mass spectrometry (GC-MS), the GC x GC-TOF MS method illustrated the obvious advantages for heavy gas oil analysis.

  20. Assessing adsorption of polycyclic aromatic hydrocarbons on Rhizopus oryzae cell wall components with water-methanol cosolvent model.

    Science.gov (United States)

    Ma, Bin; Lv, Xiaofei; He, Yan; Xu, Jianming

    2016-03-01

    The contribution of different fungal cell wall components in adsorption of polycyclic aromatic hydrocarbons (PAHs) is still unclear. We isolated Rhizopus oryzae cell walls components with sequential extraction, characterized functional groups with NEXAFS spectra, and determined partition coefficients of PAHs on cell walls and cell wall components with cosolvent model. Spectra of NEXAFS indicated that isolated cell walls components were featured with peaks at ~532.7 and ~534.5eV energy. The lipid cosolvent partition coefficients were approximately one order of magnitude higher than the corresponding carbohydrate cosolvent partition coefficients. The partition coefficients for four tested carbohydrates varied at approximate 0.5 logarithmic units. Partition coefficients between biosorbents and water calculated based cosolvent models ranged from 0.8 to 4.2. The present study proved the importance of fungal cell wall components in adsorption of PAHs, and consequently the role of fungi in PAHs bioremediation.

  1. Bioaccumulation of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and hexachlorobenzene by three Arctic benthic species from Kongsfjorden (Svalbard, Norway).

    Science.gov (United States)

    Szczybelski, Ariadna S; van den Heuvel-Greve, Martine J; Kampen, Tineke; Wang, Chenwen; van den Brink, Nico W; Koelmans, Albert A

    2016-11-15

    The predicted expansion of oil and gas (O&G) activities in the Arctic urges for a better understanding of impacts of these activities in this region. Here we investigated the influence of location, feeding strategy and animal size on the bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs) and Hexachlorobenzene (HCB) by three Arctic benthic species in Kongsfjorden (Svalbard, Norway). No toxicity was expected based on biota PAH critical body residues. Biota PCB levels were mainly below limit of detection, whereas samples were moderately polluted by HCB. PAH concentrations in biota and Biota Sediment Accumulation Factors (BSAFs) were generally higher in Blomstrandhalvøya than in Ny-Ålesund, which was explained by a higher abundance of black carbon in Ny-Ålesund harbour. BSAFs differed significantly among species and stations. We conclude that contaminant body residues are a less variable and more straightforward monitoring parameter than sediment concentrations or BSAFs in Arctic benthos.

  2. Sediment baseline study of levels and sources of polycyclic aromatic hydrocarbons and heavy metals in Lake Nicaragua

    DEFF Research Database (Denmark)

    Scheibye, Katrine; Weisser, Johan; Borggaard, Ole K.;

    2014-01-01

    Selected metals and polycyclic aromatic hydrocarbons (PAHs) were analyzed in sediment samples from 24 sites in Lake Nicaragua sampled May 2010 to provide a baseline of pollution levels. Cu exceeded the Consensus-Based Sediment Quality Guideline (CBSQG) Threshold Effect Concentrations (TECs) at 21...... showed that the CBSQG TECs were exceeded by naphthalene at five sites. The sum concentrations of the 16 US EPA priority PAHs (∑PAH16) ranged from 0.01mgkg(-1)dw to 0.64mgkg(-1)dw. The highest ∑PAH16 concentration was found upstream in River Mayales and the PAH composition revealed a heavy PAH fraction (e....... This study concluded that areas of Lake Nicaragua represent an important pollution baseline for future studies in this lake and other tropical lakes....

  3. Study of polycyclic aromatic hydrocarbons in atmospheric particulate matter of an urban area with iron and steel mills.

    Science.gov (United States)

    Menezes, Helvécio C; Cardeal, Zenilda L

    2012-07-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed from ambient air particulate matter iron and steel mills. The carcinogenic potency of priority PAHs relative to benzo[a]pyrene was estimated for a period of six months. Benzo[a]pyrene equivalents were 7.52 ng/m(3) for the study period. The estimated risk of lifetime lung cancer was 6.5 × 10(-4) . A model based on the diagnostic ratio and principal component analysis was applied for source apportionment. Considering the entire study period, the burning of biomass and fuel oil accounted for about 70% of the PAH profile. An inventory was performed during the monitoring period, with 37 companies representing major industries located in the urban area. The observations were consistent with the distribution of sources and indicated that the iron and steel sector was the largest contributor.

  4. Application of the triolein-embedded cellulose acetate membrane passive sampler for monitoring of polycyclic aromatic hydrocarbons in water.

    Science.gov (United States)

    Tang, Jianfeng; He, Guiying; Li, Gang

    2014-01-01

    Triolein-embedded cellulose acetate membrane (TECAM) can be used as a passive sampler to measure hydrophobic organic contaminants in water. Uptake constant rates (k u ) for polycyclic aromatic hydrocarbons (PAHs) by TECAM sampling were measured under different hydrodynamic conditions. The measured k u values were modeled to enable the quantification of time weighed average (TWA) concentrations of PAHs in the field. An empirical relationship that enables the calculation of in situ k u values of chemicals using performance reference compounds (PRCs) was derived and its application was demonstrated in a field study. The results showed that freely dissolved concentrations of hydrophobic organic compounds (HOCs) can be accurately measured in the field using TECAM method based on empirical uptake models calibrated with PRCs.

  5. Study of the interaction between water and hydrogen sulfide with polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cabaleiro-Lago, Enrique M; Carrazana-García, Jorge A; Rodríguez-Otero, Jesús

    2009-06-21

    A computational study has been carried out for determining the characteristics of the interaction between one water and hydrogen sulfide molecule with a series of polycyclic aromatic hydrocarbons of increasing size, namely, benzene, anthracene, triphenylene, coronene, circumcoronene, and dicircumcoronene. Potential energy curves were calculated for structures where H(2)X (X=O,S) molecule is located over the central six-membered ring with its hydrogen atoms pointing toward to (mode A) or away from (mode B) the hydrocarbon. The accuracy of different methods has been tested against the results of coupled cluster calculations extrapolated to basis set limit for the smaller hydrocarbons. The spin component scaled MP2 (SCS-MP2) method and a density functional theory method empirically corrected for dispersion (DFT-D) reproduce fairly well the results of high level calculations and therefore were employed for studying the larger systems, though DFT-D seems to underestimate the interaction in hydrogen sulfide clusters. Water complexes in mode A have interaction energies that hardly change with the size of the hydrocarbon due to compensation between the increase in the correlation contribution to the interaction energy and the increase in the repulsive character of the Hartree-Fock energy. For all the other clusters studied, there is a continuous increase in the intensity of the interaction as the size of the hydrocarbon increases, suggesting already converged values for circumcoronene. The interaction energy for water clusters extrapolated to an infinite number of carbon atoms amounts to -13.0 and -15.8 kJ/mol with SCS-MP2 and DFT-D, respectively. Hydrogen sulfide interacts more strongly than water with the hydrocarbons studied, leading to a limiting value of -21.7 kJ/mol with the SCS-MP2 method. Also, complexes in mode B are less stable than the corresponding A structures, with interaction energies amounting to -8.2 and -18.2 kJ/mol for water and hydrogen sulfide

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

    Science.gov (United States)

    Bejaoui, Salma; Salama, Farid

    2015-08-01

    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 [1, 2]. Absorption spectra of several cold, isolated gas-phase PAHs have also been measured under experimental conditions that mimic the interstellar conditions [see 3 for a review]. 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 [4] and are performed with the Pulsed Discharge Nozzle (PDN) of the COSmIC laboratory facility at NASA Ames laboratory. The PDN generates 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 examinedReferences[1] F. Salama, E. Bakes, L.J. Allamandola, A.G.G.M. Tielens, Astrophys. J., 458 (1996) p.621[2] F. Salama, The ISO Revolution, EDP Sciences, Les Ulis, France (1999) p.65[3] Salama F., In Organic Matter in Space, IAU Symposium 251, Kwok & Sandford Eds.Cambridge University Press,4, S251,(2008), p. 357 (2008) and references therein.[4

  7. Content of heterocyclic amines and polycyclic aromatic hydrocarbons in pork, beef and chicken barbecued at home by Danish consumers

    DEFF Research Database (Denmark)

    Aaslyng, Margit D.; Duedahl-Olesen, Lene; Jensen, Kirsten;

    2013-01-01

    It is a well-known fact that, when meat is barbecued, several harmful components, including heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH), may be formed. The aim of this study was to determine the HCA and PAH content in meat (pork, chicken and beef) when barbecued at home...

  8. 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

  9. 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 PA

  10. 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

  11. Identification of sources of elevated concentrations of polycyclic aromatic hydrocarbons in an industrial area in Tianjin, China

    NARCIS (Netherlands)

    Jiao, W.T.; Lu, Y.L.; Li, J.; Han, Jingyi; Wang, T.Y.; Luo, W.; Shi, Y.J.; Wang, G.

    2009-01-01

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector in 105 topsoil samples from an industrial area around Bohai Bay, Tianjin in the North of China. Results demonstrated that concentrations of PAHs in 104 so

  12. Theory and application of landfarming to remediate polycyclic aromatic hydrocarbons and mineral oil-contaminated sediments: beneficial reuse

    NARCIS (Netherlands)

    Harmsen, J.; Rulkens, W.H.; Sims, R.C.; Rijtema, P.E.; Zweers, A.J.

    2007-01-01

    When applying landfarming for the remediation of contaminated soil and sediment, a fraction of the soil-bound contaminant is rapidly degraded; however, a residual concentration may remain, which slowly degrades. Degradation of polycyclic aromatic hydrocarbons (PAHs) and mineral oil can be described

  13. 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...

  14. Diffusion Coefficients of Polychlorinated Biphenyls and Polycyclic Aromatic Hydrocarbons in Polydimethylsiloxane and Low-Density Polylethylene Polymers

    NARCIS (Netherlands)

    Rusina, T.; Smedes, F.; Klanova, J.

    2010-01-01

    Diffusion coefficients (D) of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were determined by film-stacking technique in low-density polyethylene (LDPE) and two types of polydimethylsiloxane (PDMS) (also known as silicone rubber, SR) with the trade names AlteSil (TM)

  15. FISH BILIARY POLYCYCLIC AROMATIC HYDROCARBON METABOLITES ESTIMATED BY FIXED-WAVELENGTH FLUORESCENCE: COMPARISON WITH HPLC-FLUORESCENT DETECTION

    Science.gov (United States)

    Fixed wavelength fluorescence (FF) was compared to high-performance liquid chromatography with fluorescence detection (HPLC-F) as an estimation of polycyclic aromatic hydrocarbon (PAH) exposure to fish. Two excitation/emission wavelength pairs were used to measure naphthalene- an...

  16. Repair of DNA damage induced by anthanthrene, a polycyclic aromatic hydrocarbon (PAH) without bay or fjord regions

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Johannessen, Christian; Rasmussen, Lene Juel

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants, formed during incomplete burning of coal, oil and gas. Several PAHs have carcinogenic and mutagenic potencies, but these compounds must be activated in order to exert their mutagenic effects. One of the principal pathways...

  17. Development of a Relative Potency Factor (Rpf) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of polycyclic aromatic hydrocarbon (PAH) mixtures that when finalized will appear on the Integrated Risk Information System (IRIS) database. ...

  18. THE INFRARED SPECTRA OF POLYCYCLIC AROMATIC HYDROCARBONS WITH SOME OR ALL HYDROGEN ATOMS REMOVED

    Energy Technology Data Exchange (ETDEWEB)

    Bauschlicher, Charles W. Jr. [Entry Systems and Technology Division, Mail Stop 230-3, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ricca, Alessandra, E-mail: Charles.W.Bauschlicher@nasa.gov, E-mail: Alessandra.Ricca-1@nasa.gov [Carl Sagan Center, SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States)

    2013-10-20

    The loss of one hydrogen from C{sub 96}H{sub 24} does not significantly affect the infrared spectra of the neutral, cation, or anion. Excluding a very weak C-C stretching band at 5.1 μm, the loss of two adjacent duo hydrogens does not significantly affect the spectra compared with the parent. Removing all of the hydrogen atoms significantly increases the intensity of the new C-C stretching band, and, for the cation, shifts it to a longer (5.2 μm) wavelength. Observations show a feature near 5.25 μm, which has been attributed to overtone and combination bands from polycyclic aromatic hydrocarbons (PAHs). This current work suggests that dehydrogenated PAHs might also contribute to this band, but its weakness implies that fully dehydrogenated cationic or dicationic species are very rare.

  19. 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...... 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...... at greater distances (12-24 m) contained only background levels of PAHs. The total bacterial populations (CFU and numbers of 16S rDNA genes) were similar for all soil samples, whereas the microbial degrader populations (culturable PAH degraders and numbers of PAH dioxygenase genes) were most abundant...

  20. The lack of microbial degradation of polycyclic aromatic hydrocarbons from coal-rich soils

    Energy Technology Data Exchange (ETDEWEB)

    Achten, C.; Cheng, S.B.; Straub, K.L.; Hofmann, T. [University of Vienna, Vienna (Austria)

    2011-02-02

    Analytical techniques used to assess the environmental risk of contamination from polycyclic aromatic hydrocarbons (PAHs) typically consider only abiotic sample parameters. Supercritical fluid extraction and sorption enthalpy experiments previously suggested slow desorption rates for PAH compounds in two coal-contaminated floodplain soils. In this study, the actual PAH availability for aerobic soil microorganisms was tested in two series of soil-slurry experiments. The experimental conditions supported microbial degradation of phenanthrene if it was weakly sorbed onto silica gel. Native coals and coal-derived particles in two soils effectively acted as very strong sorbents and prevented microbial PAH degradation. The long history of PAH exposure and degree of coal contamination apparently had no influence on the capability of the microbial soil community to overcome constraints of PAH availability. Within the context of the experimental conditions and the compounds chosen, our results confirm that coal-bound PAHs are not bioavailable and hence of low environmental concern.

  1. Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Bacteria Isolated from Light Oil Polluted Soils

    Science.gov (United States)

    Ohnuma, T.; Suto, K.; Inoue, C.

    2007-03-01

    Polycyclic aromatic hydrocarbons (PAHs) have polluted soil and groundwater widely and for long term because of their low solubility at normal temperature. Several microorganisms, such as Pseudomonas sp., Sphigomonas sp., a white-rot fungus and so on, being able to decompose PAHs, have been isolated and researched. This study reported to investigate biodegradation of low molecule PAH by isolated bacteria from light oil polluted soil. 12 isolates were obtained from a light oil polluted soil using naphthalene, fluorene and anthracene as sole carbon source, of which 4 isolates grew with naphthalene, 4 isolates did with fluorene and 4 isolates did with anthracene. Among them 3 isolates showed the ability to degrade phenanthrene additionally. These phenanthrene degradation and growth rates were almost same as that of S. yanoikuyae (DSM6900), which is the typical bacteria of PAHs degrader. Therefore, the isolate seemed to have an expectation for PAHs degradation.

  2. Qualitative TLC determination of some polycyclic aromatic hydrocarbons in sugar-beet

    Directory of Open Access Journals (Sweden)

    BILJANA D. SKRBIC

    2005-10-01

    Full Text Available The presence of polycyclic or polynuclear aromatic hydrocarbons (PAHs were investigated in sugar-beet from a local sugar factory in the district of Vojvodina. The sugar-beet was cultivated on areas near roads with intensive traffic. The procedure for the preparation and determination of these compounds included saponification of the sample, several liquid–liquid extraction systems and a silica gel column clean-up. The purified sample solution was analysed by thin layer chromatography (TLC on silica gel with cyclohexane as the developing solvent. Benzo(bfluoranthene and benzo(aanthracene and/or benzo(apyrene were detected at concentrations greater than the allowed limits in food.

  3. Characterizing the parent and oxygenated polycyclic aromatic hydrocarbons in mangrove sediments of Hong Kong.

    Science.gov (United States)

    Wang, Xiaowei; Yuan, Ke; Yang, Lihua; Lin, Li; Tam, Nora F Y; Chen, Baowei; Luan, Tiangang

    2015-09-15

    Parent and oxygenated polycyclic aromatic hydrocarbons (PAHs) were investigated in mangrove sediments of Hong Kong. Most of the analytes were detected, and the dominant carbonylic and hydroxylated PAHs in mangrove sediments were 9-fluorenone and 2-hydroxy fluorene, respectively. The concentration of 9-fluorenone and 9,10-anthraquinone was higher than their parent PAHs. Moreover, the concentration of total organic matter (TOM) related with those of the parent PAHs and carbonylic PAHs, except for hydroxylated PAHs, which indicated that TOM was not the only factor regulating the distribution of oxygenated PAHs. Nevertheless, the parent PAHs in mangrove sediments was correlated positively with carbonylic PAHs which demostrated not only the similar source but also the fate of these two compound class. However, hydroxylated PAHs had different source by comparing with parent PAHs and carbonylic PAHs, they were probably originated from biodegradation and accumulated in mangrove sediments.

  4. Comparison of polycyclic aromatic hydrocarbon pollution in Chinese and Japanese residential air

    Institute of Scientific and Technical Information of China (English)

    Hao Lu; Takashi Amagai; Takeshi Ohura

    2011-01-01

    Comparative studies on polycyclic aromatic hydrocarbon (PAH) pollution in residential air of Hangzhou (China) and Shizuoka (Japan) were conducted in summer (August,2006) and winter (January,2007).Total concentrations of 8 PAHs ranged from 7.1 to 320ng/m3 and 0.15 to 35 ng/m3 in residential air of Hangzhou and Shizuoka,respectively.Air PAH concentrations in smoking houses were higher than that in nonsmoking houses.In nonsmoking houses,mothball emission and cooking practice were the emission sources of 2- and 3-ring PAHs in Hangzhou,respectively.The 2- and 3-ring PAHs were from use of insect repellent,kerosene heating and outdoor environment in nonsmoking houses in Shizuoka.The 5- and 6-ring PAHs in residential air were mainly from outdoor environment in both cities.Toxicity potencies of PAHs in residential air of Hangzhou were much higher than that in Shizuoka.

  5. An unexpected restructuring of combustion soot aggregates by subnanometer coatings of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Chen, Chao; Fan, Xiaolong; Shaltout, Tasneem; Qiu, Chong; Ma, Yan; Goldman, Andrew; Khalizov, Alexei F.

    2016-10-01

    We investigated the effect of thin polycyclic aromatic hydrocarbon (PAH) coatings on the structure of soot aggregates. Soot aerosol from an inverted diffusion burner was size classified, thermally denuded, coated with six different PAHs, and then characterized using scanning electron microscopy, light scattering, and mass-mobility measurements. Contrary to our expectation, significant restructuring was observed in the presence of subnanometer layers of pyrene, fluoranthene, and phenanthrene. These PAHs remained in subcooled liquid state in thin films, whereby the liquid layer acted as a lubricant, reducing the force required to initiate the restructuring. Thin layers of PAH of higher melting temperatures (perylene, anthracene, and triphenylene) presumably remained solid because these chemicals induced lesser structural changes. Our results suggest that some of the intrinsic PAH generated during incomplete combustion may induce significant restructuring of soot aggregates, even when present in small quantities, altering the properties and atmospheric impacts of combustion aerosols.

  6. The effect of humic acids on biodegradation of polycyclic aromatic hydrocarbons depends on the exposure regime.

    Science.gov (United States)

    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.

  7. 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.

  8. Study on Removing Trace Olefins in Aromatic Hydrocarbons with HPMo-loaded Y Zeolites

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhenghong; Zeng Haiping; Shi Li

    2008-01-01

    HPMo-loaded Y-zeolites were prepared for the removal of trace olefins from aromatic hydrocarbons.The temperature of calcination and the proportion of phospho-molybdic acid in the catalyst were studied. The catalytic activity for olefins removal and the service life of the catalyst were tested in a fixed bed microreactor. The results showed that the catalyst containing 3% phospho-molybdic acid, which was calcined at 550℃,demonstrated the best activity for olefins removal. The catalyst could be regenerated and could perform still very well. Catalyst characterization was performed by XRD and measured by pyridine-FTIR spectrometry. The test results indicated that the activity of the catalyst was related with the effect of acid concentration and acid strength. Besides, the deactivation of the catalyst was associated with the formation of coke deposits and the deactivated catalyst could recover its activity by oxidation with air under a proper temperature.

  9. Inclusion of poly-aromatic hydrocarbon (PAH) molecules in a functionalized layered double hydroxide

    Indian Academy of Sciences (India)

    L Mohanambe; S Vasudevan

    2006-01-01

    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 a polar solvent into the less polar interior of the anchored cyclodextrin cavities by a partitioning process. The optical (absorption and emission) properties of the PAH molecules included within the functionalized Mg-Al layered double hydroxide solid are similar to that of dilute solutions of the PAH in non-polar solvents. The unique feature of these hybrid materials is that they are thermally stable over a wide temperature range with their emission properties practically unaltered.

  10. [Assessment of exposure to cancerogenic aromatic hydrocarbon during controlled-access highways management activities].

    Science.gov (United States)

    Martinotti, I; Cirla, A M; Cottica, D; Cirla, P E

    2011-01-01

    The purpose of this study was an integrated assessment of exposure to benzene and Polycyclic Aromatic Hydrocarbons (PAH) in 29 workers employed to manage a controlled-access highways. A campaign was performed in summertime by environmental monitoring (active and passive airborne personal sampler), as well as by biological monitoring (urine samples of the beginning and of the end of daily shift, baseline after two days of vacation). The measured environmental levels did not differ from background environmental concentrations found in a metropolitan area (i.e. benzo[a]pyrene < 1 ng/m3; benzene < 5 mcg/m3), and the results of biological monitoring were in agreement and were compatible with extra-professional habits of the investigated subjects (1-hydroxipyrene 50-990 ng/g creatinine; unmetabolized benzene 15-2010 ng/I; t-t muconic acid < 4-222 mcg/g creatinine).

  11. 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.

  12. Identification of cytochrome P4501A inducers in complex mixtures of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Villeneuve, D.L. [Michigan State Univ., East Lansing, MI (United States); DeVita, W.M.; Crunkilton, R.L. [Univ. of Wisconsin, Stevens Point, WI (United States). Coll. of Natural Resources

    1998-12-31

    An in vitro ethoxyresorufin O-deethylase (EROD) assay was used to study the ability of individual polycyclic aromatic hydrocarbons (PAHs) and mixtures of PAHs to induce Ah receptor (AhR) mediated cytochrome P4501A activity in PLHC-1 fish hepatoma cells. The purpose was to identify the most potent inducers from a set of thirteen separate PAHs and describe interactions occurring in complex mixtures of these PAHs. Where possible, potency was expressed in terms of 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TCDD-EQ) by normalizing the PAH results to a TCDD standard curve. The most potent inducers were benzo(k)fluoranthene > benzo(a)pyrene {approx} benzo(b)fluoranthene > chrysene {approx} benzo(a)anthracene. At equal concentrations, these PAHs yielded potencies of 1670, 940, 655, 255, and 185 pg TCDD-EQ/g, respectively. Analysis of various mixtures of the thirteen PAHs suggested that complex interactions may be occurring.

  13. Distribution and ecotoxicological significance of polycyclic aromatic hydrocarbons in sediments from Iko River estuary mangrove ecosystem.

    Science.gov (United States)

    Essien, Joseph P; Eduok, Samuel I; Eduok, Stephen I; Olajire, Abass Abiola

    2011-05-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in epipelic and benthic sediments from Iko River estuary mangrove ecosystem has been investigated. Total PAHs ranged from 6.10 to 35.27 mg/kg dry weight. Quantitative difference between the total PAHs in epipelic and benthic sediments showed that the benthic sediment known for higher capability to serve as sink for chemical pollutants accumulated less PAHs. This implies that PAHs in the epipelic sediment may plausibly be from industrial sources via runoff and/or of biogenic origin. A strong pyrolytic source fingerprint has been detected with slight influence of petrogenic sources. Total organic carbon normalized PAHs (sum of 16 PAHs, 59.7 to 372.4 mg/kg OC) were under (except for ES3 and BS3) the threshold effects concentrations (TEC, 290 mg/kg OC). Total PAHs in Iko River estuary sediments were in the range between ERL and ERM.

  14. Binding of polycyclic aromatic hydrocarbons by size classes of particulate in Hamilton Harbor water

    Energy Technology Data Exchange (ETDEWEB)

    Leppard, G.G. [National Water Research Inst., Burlington, Ontario (Canada). Aquatic Ecosystem Protection Branch]|[McMaster Univ., Hamilton, Ontario (Canada). Dept. of Biology; Flannigan, D.T. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Biology; Mavrocordatos, D. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Biology]|[Univ. of Lausanne (Switzerland). Dept. of Chemistry; Marvin, C.H. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Chemistry]|[Agriculture and Agri-Food Canada, Vineland Station Ontario (Canada). Pest Management Research Centre; Bryant, D.W.; McCarry, B.E. [McMaster Univ., Hamilton, Ontario (Canada)

    1998-11-15

    In aquatic systems there is considerable transport of organic contaminants on suspended particles that act as carriers and influence the redistribution, bioavailability, and ultimate fate of contaminants. Using methodology not previously applied to the analysis of lake water, the authors demonstrate that polycyclic aromatic hydrocarbons (PAH) in Hamilton Harbor are predominantly sorbed to suspended flocs. Techniques employed were as follows: (i) differential cascade sedimentation and centrifugation to separate suspended particles; (ii) scanning transmission electron microscopy and energy-dispersive spectroscopy to identify flocs and individual particles in the size range of 10{sup {minus}3}--10{sup 3} {micro}m; (iii) gas chromatography-mass spectrometry to identify PAH in extracts prepared from size classes. Heterogeneous flocs larger than 20 {micro}m accounted for roughly 98% of phenanthrene binding, 89% of fluoranthene binding, and 85% of pyrene binding.

  15. Compost-mediated removal of polycyclic aromatic hydrocarbons from contaminated soil.

    Science.gov (United States)

    Sasek, V; Bhatt, M; Cajthaml, T; Malachová, K; Lednická, D

    2003-04-01

    Compost-assisted remediation of a manufactured-gas plant soil contaminated with polycyclic aromatic hydrocarbons (PAHs) was performed in thermally insulated composting chamber using mushroom compost consisting wheat straw, chicken manure, and gypsum. The degradation of individual PAHs was in range of 20-60% at the end of 54 days of composting followed by further increase of PAH removal (37-80%) after another 100 days of maturation. Both chemical analysis of the contaminated soil for PAHs and ecotoxicity tests on bioluminescent bacteria, earthworms, and plant seeds were performed before and after the composting. After the composting, inhibition of bioluminescence decreased, whereas no significant change in toxicity was observed for earthworm survival and seed germination. Using bacterial culture of Escherichia coli K12 genotoxicity tests were performed on samples taken from different parts of the composting pile; after the composting the decrease in genotoxicity was observed only in the sample taken from upper part of the composted pile.

  16. 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.

  17. Polycyclic aromatic hydrocarbons (PAHs) in bio-crudes from induction-heating pyrolysis of biomass wastes.

    Science.gov (United States)

    Tsai, Wen-Tien; Mi, Hsiao-Hsuan; Chang, Yuan-Ming; Yang, Shyh-Yu; Chang, Jeng-Hung

    2007-03-01

    The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography/mass spectrometry (GC/MS) revealed that the PAHs in bio-crudes were primarily dominant in the low molecular weight (LMW) PAHs, including naphthalene (1.10-2.45 mg/L) and acenaphthene (0.72-7.61 mg/L). However, by considering carcinogenic potency, the bio-crudes from rice husk and sugarcane bagasse contained higher contents of benzo[a]pyrene (BaP) (0.52 and 0.92 mg/L, respectively) as compared to those from rice straw and coconut shell.

  18. Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Z. [College of Environmental Sciences, Peking University, Beijing 100871 (China); Tao, S. [College of Environmental Sciences, Peking University, Beijing 100871 (China)]. E-mail: taos@urban.pku.edu.cn; Pan, B. [College of Environmental Sciences, Peking University, Beijing 100871 (China); Liu, W.X. [College of Environmental Sciences, Peking University, Beijing 100871 (China); Shen, W.R. [Tianjin Environmental Protection Bureau, Tianjin 300191 (China)

    2007-03-15

    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 {sub 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. - Distribution of PAHs among water, suspended solids and sediment was under strong influence of naturally occurring organic carbon.

  19. 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

    Khuzestan, Iran is heavily industrialised with petrochemical and refinery companies. Herein, sediment and soil samples were collected from Hendijan coast, Khore Mosa and Arvandroud River. The CHEMSIC (CHEmometric analysis of Selected Ion Chromatograms) method was used to assign the main sources...... 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...... weathered petrogenic and pyrogenic, and PC4 is indicative for a diagenetic input. The sources of PAHs in the Arvandroud River were mainly relatively fresh oil with some samples corresponding to a weathered oil input. Further, perylene (indicator for diagenetic source) was identified. Samples from Khore Mosa...

  20. Mycobacterium pyrenivorans sp. nov., a novel polycyclic-aromatic-hydrocarbon-degrading species.

    Science.gov (United States)

    Derz, Kerstin; Klinner, Ulrich; Schuphan, Ingolf; Stackebrandt, Erko; Kroppenstedt, Reiner M

    2004-11-01

    The taxonomic position of a polycyclic-aromatic-hydrocarbon-degrading bacterium, strain 17A3(T), isolated from contaminated soil was determined using a combination of phenotypic and genotypic properties. The isolate showed phenotypic properties that were diagnostic for species of the genus Mycobacterium. Comparative 16S rRNA gene sequence analysis assigned 17A3(T) to the 16S rRNA gene subgroup that contains Mycobacterium aurum, Mycobacterium austroafricanum, Mycobacterium vaccae and Mycobacterium vanbaalenii, but it could clearly be distinguished from these species using a combination of physiological, chemotaxonomic markers and internal rRNA gene spacer analyses. The data showed that strain 17A3(T) (=DSM 44605(T)=NRRL B-24244(T)) merits recognition as the type strain of a novel species of the genus Mycobacterium. The name Mycobacterium pyrenivorans sp. nov. is proposed for the species because of its ability to use pyrene as a sole source of carbon and energy.

  1. Role of volcanic dust in the atmospheric transport and deposition of polycyclic aromatic hydrocarbons and mercury.

    Science.gov (United States)

    Stracquadanio, Milena; Dinelli, Enrico; Trombini, Claudio

    2003-12-01

    The role of volcanic ash as scavenger of atmospheric pollutants, in their transport and final deposition to the ground is examined. Attention is focused on polycyclic aromatic hydrocarbons (PAHs) and on particulate mercury (Hgp). The ash-fall deposits studied belong to the 2001 and 2002 eruptive activity of Mount Etna, Southern Italy, and were investigated at three (2001) and four (2002) sites downwind of the major tephra dispersal pattern. The dry deposition of mercury and PAHs was determined, and, in particular, a downward flux to the ground of PAHs (approximately 7.29 microg m(-2) per day) and mercury (750 ng m(-2) per day) was estimated in Catania from October 26 to October 28, 2002. Finally, evidence on the anthropogenic origin of PAHs scavenged from the troposphere by volcanic ash is supported by the analysis of PAH compositions in granulometrically homogeneous fractions.

  2. Isomer discrimination of polycyclic aromatic hydrocarbons in the Murchison meteorite by resonant ionization.

    Science.gov (United States)

    Callahan, Michael P; Abo-Riziq, Ali; Crews, Bridgit; Grace, Louis; de Vries, Mattanjah S

    2008-12-15

    We have used two-color resonant two-photon ionization (2C-R2PI) mass spectrometry to discriminate between isomers of polycyclic aromatic hydrocarbons in the Murchison meteorite. We measured the 2C-R2PI spectra of chrysene and triphenylene seeded in a supersonic jet by laser desorption. Since each isomer differs in its R2PI spectrum, we can distinguish between isomers using wavelength dependent ionization and mass spectrometry. We found both chrysene and triphenylene in sublimates from carbonaceous residue obtained by acid demineralization of the Murchison meteorite. Their R2PI mass spectra show only the molecular ion, even though these samples contain a complex inventory of organic molecules.

  3. Aromatic hydrocarbons associated with brines from geopressured wells. Annual report, fiscal 1985

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, D.F.; Meriwether, J.R.

    1985-01-01

    Samples of cryocondensates - materials condensed at - 78.5/sup 0/C were taken on a regular basis from the gas stream for the USDOE geopressured wells. Most of the data has been taken from the Gladys McCall well as it has flowed on a regular and almost continous basis. The cryocondensates, not the ''condensate'' from gas wells, are almost exclusively aromatic hydrocarbons, primarily benzene, toluene, ethylbenzene, and the xylenes, but contain over 95 compounds, characterized using gas chromatographic-mass spectroscopy. The solubility in water and brine of benezene, toluene, ethylbenzene and o-xylene, some of the components of the cryocondensate, as well as distribution coefficients between water or brine and a standard oil have been measured. 25 refs.

  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.

  5. Formation of H{sub 2} from internally heated polycyclic aromatic hydrocarbons: Excitation energy dependence

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T., E-mail: tao.chen@fysik.su.se, E-mail: henning@fysik.su.se; Gatchell, M.; Stockett, M. H.; Schmidt, H. T.; Cederquist, H.; Zettergren, H., E-mail: tao.chen@fysik.su.se, E-mail: henning@fysik.su.se [Department of Physics, Stockholm University, S-106 91 Stockholm (Sweden); Delaunay, R.; Rousseau, P.; Adoui, L. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen cedex 05 (France); Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen (France); Domaracka, A.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen cedex 05 (France); Micelotta, E. R. [Université Paris Sud, Institut d’Astrophysique Spatiale, UMR 8617, 91405 Orsay (France); Tielens, A. G. G. M. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2015-04-14

    We have investigated the effectiveness of molecular hydrogen (H{sub 2}) formation from Polycyclic Aromatic Hydrocarbons (PAHs) which are internally heated by collisions with keV ions. The present and earlier experimental results are analyzed in view of molecular structure calculations and a simple collision model. We estimate that H{sub 2} formation becomes important for internal PAH temperatures exceeding about 2200 K, regardless of the PAH size and the excitation agent. This suggests that keV ions may effectively induce such reactions, while they are unlikely due to, e.g., absorption of single photons with energies below the Lyman limit. The present analysis also suggests that H{sub 2} emission is correlated with multi-fragmentation processes, which means that the [PAH-2H]{sup +} peak intensities in the mass spectra may not be used for estimating H{sub 2}-formation rates.

  6. Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies.

    Science.gov (United States)

    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.

  7. 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.

  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. A review of airborne polycyclic aromatic hydrocarbons (PAHs) and their human health effects.

    Science.gov (United States)

    Kim, Ki-Hyun; Jahan, Shamin Ara; Kabir, Ehsanul; Brown, Richard J C

    2013-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds comprised of two or more fused benzene rings arranged in various configurations. PAHs are widespread environmental contaminants formed as a result of incomplete combustion of organic materials such as fossil fuels. The occurrence of PAHs in ambient air is an increasing concern because of their carcinogenicity and mutagenicity. Although emissions and allowable concentrations of PAHs in air are now regulated, the health risk posed by PAH exposure suggests a continuing need for their control through air quality management. In light of the environmental significance of PAH exposure, this review offers an overview of PAH properties, fates, transformations, human exposure, and health effects (acute and chronic) associated with their emission to the atmosphere. Biomarkers of PAH exposure and their significance are also discussed.

  10. 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.

  11. 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.

  12. High-resolution IR absorption spectroscopy of polycyclic aromatic hydrocarbons: the realm of anharmonicity

    CERN Document Server

    Maltseva, Elena; Candian, Alessandra; Mackie, Cameron J; Huang, Xinchuan; Lee, Timothy J; Tielens, Alexander G G M; Oomens, Jos; Buma, Wybren Jan

    2015-01-01

    We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micron CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (~4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilises intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination ...

  13. Aromatic hydrocarbon pathology in fish following a large spill into the Nemadji River, Wisconsin, USA

    Science.gov (United States)

    Caldwell, C.A.

    1997-01-01

    On June 30, 1992, a train accident resulted in a rail car releasing 114,000 L of a complex mixture of aromatic hydrocarbons into the Nemadji River, a tributary of Lake Superior near Superior, Wisconsin (Table 1). Although the majority of the spilled material evaporated, damage to aquatic life was extensive. Several thousand fishes were killed and an inestimable number were exposed to low concentrations (exposure to determine the extent of injury when compared to fishes collected from the reference site. The liver, spleen, gill, and head kidney were examined for histopathology. Blood was collected to determine the severity of liver damage reflected by the presence of the serum enzymes (aspartate aminotransferase, alanine aminotransferase, and d - glutamyl transferase).

  14. 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.

  15. Analysis of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHS): an overview of modern electroanalytical techniques and their applications.

    Science.gov (United States)

    Şentürk, Zühre

    2013-02-01

    A number of Polycyclic Aromatic Hydrocarbons (PAHs) have been shown to be toxicants, and induce carcinogenic and immunotoxic effects. Since PAHs are often present in low concentrations and it may be difficult to determine them in complex matrices, it is therefore essential to use powerful analytical tools to separate and identify the analyses in the samples. In this paper, initially, a short description of the principles, instrumentation, and use of common extraction and analytical techniques for PAH pollutants and their metabolites will be made in light of the previously reported works and major reviews. Special attention will be given to the use of modern polarographic and voltammetric techniques on the mercury and different types of solid electrodes, together with their some practical applications. The main drawbacks and limitations of these methods will also be discussed.

  16. Polycyclic aromatic hydrocarbon pollution in the surface water and sediments of Chabahar Bay, Oman Sea.

    Science.gov (United States)

    Agah, Homira; Mehdinia, Ali; Bastami, Kazem Darvish; Rahmanpour, Shirin

    2017-02-15

    In the present study, the concentrations and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in the water and surface sediments from the Chabahar Bay, Oman Sea, were investigated in May (premonsoon) and December (postmonsoon) 2012. The concentrations of PAHs in the surface water samples ranged from 1.7 to 2.8ngl(-1) and from 0.04 to 59.6ngl(-1) in pre- and postmonsoon, respectively. In general, the PAH levels of the water samples from Chabahar Bay were higher in postmonsoon than in premonsoon (p<0.05). The concentrations of PAHs in the sediment samples varied from undetectable levels to 92.8ngg(-1) d.w. in both seasons. The seasonal comparison of the results in sediment samples showed that the overall concentration of PAH compounds was higher in the postmonsoon season (p<0.05).

  17. Characterisation and Treatment of Nano-sized Particles, Colloids and Associated Polycyclic Aromatic Hydrocarbons in Stormwater

    DEFF Research Database (Denmark)

    Nielsen, Katrine

    facilities in Denmark. This is a consequence of climate changes, with increasing precipitation in Europe. The increased precipitation causes problems with hydraulic overloading of sewer systems and therefore stormwater is directed into stormwater drainage systems and to stormwater treatment facilities...... 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......-sized particles in the stormwater, in terms of particle size distribution (PSD) and zeta potential. In combination with the characterisation of the particles, concentrations of organic and inorganic compounds were quantified in the stormwater, with a focus on PAHs, together with physical and chemical parameters...

  18. Sorption of polycyclic aromatic hydrocarbons (PAHs by dietary fiber extracted from wheat bran

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-10-01

    Full Text Available The unintentional ingestion of carcinogenic xenobiotic substances leads to the high risk of cancer. Dietary fiber (DF may protect against cancer by sorbing such chemicals. To this end, the sorption of four polycyclic aromatic hydrocarbons (PAHs to DF extracted from wheat bran (WB was studied. The strong affinity of PAHs to DF and WB indicated the effective binding of PAHs, and their distribution coefficients (Kd positively increased with the increase in hydrophobicity of the PAHs. The DF had much higher Kd values for all PAHs compared to those of the unprocessed WB. The DF extraction process removed hydrophilic residues, such as starch, from WB, and increased the roughness of DF surface. Loss of hydrophilic components from WB to DF led to much higher affinity of DF with PAHs than WB. The results indicate that the DF can effectively sorb and remove xenobiotics, thereby having the potential to lower carcinogenic risk to humans.

  19. 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.

  20. Distribution and sources of polycyclic aromatic hydrocarbons in main aquacultural areas in Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    MASKAOUI Khalid; HU Zhong; ZHOU Junliang; HAN Yali

    2007-01-01

    The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogenic sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.

  1. Sorption effects interfering with the analysis of polycyclic aromatic hydrocarbons (PAH) in aqueous samples.

    Science.gov (United States)

    Krüger, Oliver; Kalbe, Ute; Meißner, Kerstin; Sobottka, Sebastian

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAH) are severe environmental pollutants that are analyzed frequently. The risk assessment of PAH impact to groundwater can be performed using leaching tests. Therby a liquid-solid separation step including centrifugation may be required, which in turn might lead to loss of analytes due to sorption on the equipment. Thus we determined the PAH recoveries from various container materials (polyethylene (PE), polypropylene (PP), polytetraflourethylene (PTFE), stainless steel (ES), and perflouroalkoxy (PFA)) and compared them to selected PAH properties. We found the best recoveries for PFA (68%) and PTFE (65%) containers. We found good negative correlations (-0.93 and better) between PAH recovery and log partition coefficient organic carbon-water (logKOC) for PFA, PTFE, and ES containers.

  2. Determination of polycyclic aromatic hydrocarbon (PAH) content and risk assessment from edible oils in Korea.

    Science.gov (United States)

    Kang, Bomi; Lee, Byung-Mu; Shin, Han-Seung

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAH) content and a risk assessment from consumption of Korean edible oils were investigated. Liquid-liquid extraction and gas chromatography-mass spectroscopy were used to measure eight PAH in edible oils commonly consumed in Korea. The total average PAH concentration was 0.548 μg/kg from edible oils and the content of the 8 PAH was lower than 2 μg/kg, which is the maximum tolerable limit reported by the commission regulation. The contents of the eight PAH were converted to exposure assessment and risk characterization values. Dietary exposure to PAH from edible oils was 0.025 ng-TEQBaP/kg/d, and margin of exposure (MOE) was 4 × 10(6), which represents negligible concern. Although PAH were detected from edible oils in Korea, their contribution to human exposure to PAH is considered not significant.

  3. Photolysis of polycyclic aromatic hydrocarbons on soil surfaces under UV irradiation

    Institute of Scientific and Technical Information of China (English)

    Chengbin Xu; Dianbo Dong; Xuelian Meng; Xin Su; Xu Zheng; Yaoyao Li

    2013-01-01

    Photolysis of some polycyclic aromatic hydrocarbons (PAHs) on soil surfaces may play an important role in the fate of PAHs in the environment.Photolysis of PAHs on soil surfaces under UV irradiation was investigated.The effects of oxygen,irradiation intensity and soil moisture on the degradation of the three PAHs were observed.The results showed that oxygen,soil moisture and irradiation intensity enhanced the photolysis of the three PAHs on soil surfaces.The degradation of the three PAHs on soil surfaces is related to their absorption spectra and the oxidation-half-wave potential.The photolysis of PAHs on soil surfaces in the presence of oxygen followed pseudo first-order kinetics.The photolysis half-lives ranged from 37.87 days for benzo[a]pyrene to 58.73 days for phenanthrene.The results indicate that photolysis is a successful way to remediate PAHs-contaminated soils.

  4. Polycyclic aromatic hydrocarbon-DNA adducts in beluga whales from the Arctic.

    Science.gov (United States)

    Mathieu, A; Payne, J F; Fancey, L L; Santella, R M; Young, T L

    1997-05-01

    The Arctic is still relatively pristine in nature, but it is also vulnerable to pollution because contaminants originating from midlatitudes are transported to the Arctic by atmospheric processes, ocean currents, and rivers (Muir et al., 1992). Recognition of this fact of Arctic vulnerability has resulted in a Declaration on the Protection of the Arctic Environment by eight Arctic countries. A manifest aim of this declaration is to develop an Arctic Monitoring and Assessment Program. We report here on the presence of measurable levels of polycyclic aromatic hydrocarbon-DNA adducts, including relatively high levels in Arctic beluga (Delphinapterus leucas). These results lend support to the value of developing biological assessment programs for Arctic wildlife.

  5. Emission factors of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from residential solid fuel combustions

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Guofeng [Jiangsu Academy of Environmental Science, Nanjing (China). Inst. of Atmospheric Sciences

    2014-07-01

    Emission inventory is basic for the understanding of environmental behaviors and potential effects of compounds, however, current inventories are often associated with relatively high uncertainties. One important reason is the lack of emission factors, especially for the residential solid fuel combustion in developing countries. In the present study, emission factors of a group of pollutants including particulate matter, organic carbon, elemental carbon (sometimes known as black carbon) and polycyclic aromatic hydrocarbons were measured for a variety of residential solid fuels including coal, crop straw, wood, and biomass pellets in rural China. The study provided a large number of emission factors that can be further used in emission estimation. Composition profiles and isomer ratios were investigated and compared so as to be used in source apportionment. In addition, the present study identified and quantified the influence of factors like fuel moisture, volatile matter on emission performance.

  6. Study of nitro-polycyclic aromatic hydrocarbons in fine and coarse atmospheric particles

    Science.gov (United States)

    Teixeira, Elba Calesso; Garcia, Karine Oliveira; Meincke, Larissa; Leal, Karen Alam

    2011-08-01

    The purpose of the present study was to evaluate six nitro-polycyclic aromatic hydrocarbons (NPAHs) in fine (MAPA), RS, Brazil. The method used was of NPAHs isolation and derivatization, and subsequent gas chromatography by electron capture detection (CG/ECD). Results revealed a higher concentration of NPAHs, especially 3-nitrofluoranthene and 1-nitropyrene, in fine particles in the sampling sites studied within the MAPA. The diagnostic ratios calculated for PAHs and NPAHs identified the influence of heavy traffic, mainly of diesel emissions. The correlation of NPAHs with other pollutants (NO x, NO 2, NO and O 3) evidence the influence of vehicular emissions in the MAPA. The seasonal variation evidenced higher NPAHs concentrations in the fine particles during winter for most compounds studied.

  7. 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.

  8. Isolation and characterization of different bacterial strains for bioremediation of n-alkanes and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Guermouche M'rassi, A; Bensalah, F; Gury, J; Duran, R

    2015-10-01

    Crude oil is a common environmental pollutant composed of a large number of both aromatic and aliphatic hydrocarbons. Biodegradation is carried out by microbial communities that are important in determining the fate of pollutants in the environment. The intrinsic biodegradability of the hydrocarbons and the distribution in the environment of competent degrading microorganisms are crucial information for the implementation of bioremediation processes. In the present study, the biodegradation capacities of various bacteria toward aliphatic and aromatic hydrocarbons were determined. The purpose of the study was to isolate and characterize hydrocarbon-degrading bacteria from contaminated soil of a refinery in Arzew, Algeria. A collection of 150 bacterial strains was obtained; the bacterial isolates were identified by 16S rRNA gene sequencing and their ability to degrade hydrocarbon compounds characterized. The isolated strains were mainly affiliated to the Gamma-Proteobacteria class. Among them, Pseudomonas spp. had the ability to metabolize high molecular weight hydrocarbon compounds such as pristane (C19) at 35.11 % by strain LGM22 and benzo[a] pyrene (C20) at 33.93 % by strain LGM11. Some strains were able to grow on all the hydrocarbons tested including octadecane, squalene, phenanthrene, and pyrene. Some strains were specialized degrading only few substrates. In contrast, the strain LGM2 designated as Pseudomonas sp. was found able to degrade both linear and branched alkanes as well as low and high poly-aromatic hydrocarbons (PAHs). The alkB gene involved in alkane degradation was detected in LGM2 and other Pseudomonas-related isolates. The capabilities of the isolated bacterial strains to degrade alkanes and PAHs should be of great practical significance in bioremediation of oil-contaminated environments.

  9. Polycyclic aromatic hydrocarbons in Australian coals. I. Angularly fused pentacyclic tri- and tetraaromatic components of Victorian brown coal

    Science.gov (United States)

    Chaffee, Alan L.; Johns, R. B.

    1983-12-01

    Analysis of the tri- and tetraaromatic hydrocarbon fractions of a brown coal sample from the Latrobe Valley, Victoria, Australia indicate the predominance of pentacyclic hydroaromatic components. Many of these have not been previously reported in the literature, but are obviously diagenetically related to triterpenoids naturally occurring in the biosphere. The components whose molecular structures have been confirmed, together with those for which tentative structural assignments are given, offer strong support for a theory of progressive diagenetic aromatization of C-3 oxygenated triterpenoids, commencing from ring A. Other compounds present in smaller amounts suggest that 1,2-methyl shift reactions also occur prior to or during aromatization. There is a notable absence of polycyclic aromatic hydrocarbons (PAH's) which can be diagenetically related to the steroid or extended-side-chain hopane skeletons.

  10. Biodiesel presence in the source zone hinders aromatic hydrocarbons attenuation in a B20-contaminated groundwater

    Science.gov (United States)

    Ramos, Débora Toledo; Lazzarin, Helen Simone Chiaranda; Alvarez, Pedro J. J.; Vogel, Timothy M.; Fernandes, Marilda; do Rosário, Mário; Corseuil, Henry Xavier

    2016-10-01

    The behavior of biodiesel blend spills have received limited attention in spite of the increasing and widespread introduction of biodiesel to the transportation fuel matrix. In this work, a controlled field release of biodiesel B20 (100 L of 20:80 v/v soybean biodiesel and diesel) was monitored over 6.2 years to assess the behavior and natural attenuation of constituents of major concern (e.g., BTEX (benzene, toluene, ethyl-benzene and xylenes) and PAHs (polycyclic aromatic hydrocarbons)) in a sandy aquifer material. Biodiesel was preferentially biodegraded compared to diesel aromatic compounds with a concomitant increase in acetate, methane (near saturation limit (≈ 22 mg L- 1)) and dissolved BTEX and PAH concentrations in the source zone during the first 1.5 to 2.0 years after the release. Benzene and benzo(a)pyrene concentrations remained above regulatory limits in the source zone until the end of the experiment (6.2 years after the release). Compared to a previous adjacent 100-L release of ethanol-amended gasoline, biodiesel/diesel blend release resulted in a shorter BTEX plume, but with higher residual dissolved hydrocarbon concentrations near the source zone. This was attributed to greater persistence of viscous (and less mobile) biodiesel than the highly-soluble and mobile ethanol in the source zone. This persistence of biodiesel/diesel NAPL at the source zone slowed BTEX and PAH biodegradation (by the establishment of an anaerobic zone) but reduced the plume length by reducing mobility. This is the first field study to assess biodiesel/diesel blend (B20) behavior in groundwater and its effects on the biodegradation and plume length of priority groundwater pollutants.

  11. A novel cloud-point extraction process for preconcentrating selected polycyclic aromatic hydrocarbons in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Bai, D.; Li, J.; Chen, S.B.; Chen, B.-H. [National University of Singapore (Singapore). Dept. of Chemical and Environmental Engineering

    2001-10-01

    Polycyclic aromatic hydrocarbons (PAHs) released in such processes as incomplete coal combustion and during the disposal of coal tar, are subject to strict emission controls in which the determination of PAHs has to be addressed. PAHs have low aqueous solubility which necessitates preconcentration prior to the analytical determination of PAHs. A novel but simple cloud-point extraction (CPE) process is developed to preconcentrate the trace of selected polycyclic aromatic hydrocarbons (PAHs) with the use of the readily biodegradable nonionic surfactant of secondary ethyoxylated alcohol Tergitol 15-S-7 as extractant. The concentrations of PAHs, mixtures of naphthalene and phenanthrene as well as pyrene in the spiked samples were determined with the new CPE process at ambient temperature (23{degree}C) followed by high performance liquid chromatography (HPLC) with fluorescence detection. More than 80% of phenanthrene and pyrene, respectively, and 96% of naphthalene initially present in the aqueous solutions with concentrations near or below their aqueous solubilities were recovered using this new CPE process. Importantly Tergitol 15-S-7 does not give any fluorometric signal to interfere with fluorescence detection of PAHs in the UV range. No special washing step is, thus, required to remove surfactant before HPLC analyses. Different experimental conditions were studied. The optimum conditions for the preconcentration and determination of these selected PAHs at ambient temperature have been established as the following: (1) 3 wt% surfactant; (2) addition of 0.5 M Na{sub 2}SO{sub 4}; (3) 10 min for equilibration time; and (4) 3000 rpm for centrifugal speed with duration of 10 min. 50 refs., 7 figs.

  12. Urinary metabolites of polycyclic aromatic hydrocarbons in Saudi Arabian schoolchildren in relation to sources of exposure.

    Science.gov (United States)

    Alghamdi, Mansour A; Alam, Mohammed S; Stark, Christopher; Mohammed, Nuredin; Harrison, Roy M; Shamy, Magdy; Khoder, Mamdouh I; Shabbaj, Ibrahim I; Göen, Thomas

    2015-07-01

    Polycyclic aromatic hydrocarbons contain a number of known carcinogenic compounds, and urinary biomarkers have been widely used as a measure of exposure but quantitative relationships with exposure variables have proved elusive. This study aimed to quantify the relationship between exposures to phenanthrene and pyrene from atmospheric and dietary sources with the excretion of 1-hydroxypyrene and hydroxyphenanthrenes in urine as biomarkers of exposure. The study population consisted of 204 male schoolchildren attending three schools in different parts of Jeddah, Saudi Arabia who provided urine samples on each of three consecutive days. Outdoor air measurements of polycyclic aromatic hydrocarbons were made at the schools and the children provided information on diet, exposure to environmental tobacco smoke and incense, and various lifestyle factors through a questionnaire. Mixed models with random effects for subjects nested within site were fitted in order to examine the relationship between exposure variables and urinary PAH metabolites. A unit increase (1 ng m(-3)) in ambient pyrene (particulate plus gaseous phase) was associated with a 3.5% (95% CI: 1.01%, 5.13%) increase in urinary 1-hydroxypyrene concentration. A unit increase in ambient phenanthrene was associated with a 1.01% (95% CI: 0.03%, 2.02%) increase in total hydroxyphenanthrene concentrations. Consumption of chargrilled food increased the 1-hydroxypyrene and hydroxyphenanthrene concentrations by 24% (95% CI: 11%, 37%) and 17% (95% CI: 8%, 26%) respectively. We did not find evidence of association for environmental tobacco smoke exposure or incense burning. It is concluded that both respiratory exposure and consumption of chargrilled food are considerable sources of PAH exposure in this population as reflected by concentrations of urinary biomarkers.

  13. Role of glyoxal in SOA formation from aromatic hydrocarbons: gas-phase reaction trumps reactive uptake

    Directory of Open Access Journals (Sweden)

    S. Nakao

    2011-11-01

    Full Text Available This study evaluates the significance of glyoxal acting as an intermediate species leading to SOA formation from aromatic hydrocarbon photooxidation under humid conditions. Rapid SOA formation from glyoxal uptake onto aqueous (NH42SO4 seed particles is observed; however, glyoxal did not partition to SOA or SOA coated aqueous seed during all aromatic hydrocarbon experiments (RH up to 80%. Glyoxal is found to only influence SOA formation by raising hydroxyl (OH radical concentrations. Four experimental approaches supporting this conclusion are presented in this paper: (1 increased SOA formation and decreased SOA volatility in the toluene + NOx photooxidation system with additional glyoxal was reproduced by matching OH radical concentrations through H2O2 addition; (2 glyoxal addition to SOA seed formed from toluene + NOx photooxidation did not increase observed SOA volume; (3 SOA formation from toluene + NOx photooxidation with and without deliquesced (NH42SO4 seed resulted in similar SOA growth, consistent with a coating of SOA preventing glyoxal uptake onto deliquesced (NH42SO4 seed; and (4 the fraction of a C4H9+ fragment (observed by Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer, HR-ToF-AMS from SOA formed by 2-tert-butylphenol (BP oxidation was unchanged in the presence of additional glyoxal despite enhanced SOA formation. This study suggests that glyoxal uptake onto aerosol is minor when the surface (and near-surface of aerosols are primarily composed of secondary organic compounds.

  14. [Improving Agricultural Safety of Soils Contaminated with Polycyclic Aromatic Hydrocarbons by In Situ Bioremediation].

    Science.gov (United States)

    Jiao, Hai-huan; Pan, Jian-gang; Xu, Shena-jun; Bai, Zhi-hui; Wang, Dong; Huang, Zhan-bin

    2015-08-01

    In order to reduce the risk of enrichment of polycyclic aromatic hydrocarbons (PAHs) in crops, reduce the potential hazards of food-sourced PAHs to human and increase the agricultural safety of PAHs contaminated soils, the bio-augmented removal of polycyclic aromatic hydrocarbons (PAHs) was investigated through in situ remediation by introducing Rhodobacter sphaeroides (RS) into the agricultural soil contaminated by PAHs. The 50-times diluted RS was sprayed on leaf surface (in area B) or irrigated to roots (in area D). The treatment of spraying water of the equal amount was taken as the control (A) and the wheat field without any treatment as the blank (CK). Treatments were conducted since wheat seeding. Soil and wheat samples were collected in the mature period to analyze the changes of community structure of the soil microorganisms and the concentration of PAHs in soils and investigate the strengthening and restoration effects of RS on PAHs contaminated soils. Compared to the CK Area, the areas B and D revealed that the variation ratio of phospholipid fatty acids (PLFAs) that were the biomarker of soil microorganisms was 29.6%, and the ratio of total PAHs removed was increased 1.59 times and 1.68 times, respectively. The dry weight of wheat grain of 50 spikes was increased by 8.95% and 12.5%, respectively, and the enrichment factor of total PAHs was decreased by 58.9% and 62.2% respectively in the wheat grains. All the results suggested that RS reduced enrichment of PAHs in wheat grains and increased wheat yield, which had great exploitation and utilization potentiality in repairing and improving the agricultural safety of the soils contaminated with PHAs.

  15. Theoretical Infrared Spectra for Polycyclic Aromatic Hydrocarbon Neutrals, Cations and Anions

    Science.gov (United States)

    Langhoff, Stephen R.

    1995-01-01

    Calculations are carried out using density functional theory (DFT) to determine the harmonic frequencies and intensities of the neutrals and cations of thirteen polycyclic aromatic hydrocarbons (PAHs) up to the size of ovalene. Calculations are also carried out for a few PAH anions. The DFT harmonic frequencies, when uniformly scaled by the factor of 0.958 to account primarily for anharmonicity, agree with the matrix isolation fundamentals to within an average error of about 10 per centimeter. Electron correlation is found to significantly reduce the intensities of many of the cation harmonics, bringing them into much better agreement with the available experimental data. While the theoretical infrared spectra agree well with the experimental data for the neutral systems and for many of the cations, there are notable discrepancies with the experimental matrix isolation data for some PAH cations that are difficult to explain in terms of limitations in the calculations. In agreement with previous theoretical work, the present calculations show that the relative intensities for the astronomical unidentified infrared (UIR) bands agree reasonably well with those for a distribution of polycyclic aromatic hydrocarbon (PAH) cations, but not with a distribution of PAH neutrals. We also observe that the infrared spectra of highly symmetrical cations such as coronene agree much better with astronomical observations than do those of, for example, the polyacenes such as tetracene and pentacene. The total integrated intensities for the neutral species are found to increase linearly with size, while the total integrated intensities are much larger for the cations and scale more nearly quadratically with size. We conclude that emission from moderate-sized highly symmetric PAH cations such as coronene and larger could account for the UIR bands.

  16. Association between a biomarker of exposure to polycyclic aromatic hydrocarbons and semen quality

    Directory of Open Access Journals (Sweden)

    Joanna Jurewicz

    2013-10-01

    Full Text Available Objectives: Growing evidence supports the reproductive and developmental toxicity of polycyclic aromatic hydrocarbons (PAHs from prenatal and postnatal exposure, but the results of epidemiological studies regarding harmful effects of PAHs exposure on male reproductive system still remain limited and inconclusive. The aim of the present study was to investigate the relationship between 1-hydroxypyrene, a biomarker of polycyclic aromatic hydrocarbons exposure and semen quality. Materials and Methods: The study population consisted of 277 men attending an infertility clinic for diagnostic purposes and having normal semen concentration of 20-300 mln/ml or slight oligozoospermia (semen concentration: 15-20 mln/ml (WHO 1999. All the men were healthy and under 45 years of age. All participants were interviewed and provided a semen sample. The interview included questions concerning demographics, socio-economic status, medical history related to past diseases which may have an impact on semen quality, lifestyle factors and occupational information. Concentrations of 1-hydroxypyrene (1-OHP in the urine samples were analyzed using high performance liquid chromatography (HPLC. Results: A positive association was found between the level of 1-OHP in urine and sperm neck abnormalities as well as the percentage of static sperm cells (p = 0.001, p = 0.018, respectively. Additionally, exposure to PAHs measured by 1-OHP in urine decreased semen volume and the percentage of motile sperm cells (p = 0.014, p = 0.0001, respectively. Conclusions: Presented findings indicate that the environmental level of PAHs exposure adversely affects male semen quality. The future large-scale studies should incorporate different biomarkers to generate a more accurate and full assessment of the effects of PAHs exposure on male fertility.

  17. Biological Monitoring of Occupational Exposure to Polycyclic Aromatic Hydrocarbons at an Electric Steel Foundry in Tunisia.

    Science.gov (United States)

    Campo, Laura; Hanchi, Mariem; Olgiati, Luca; Polledri, Elisa; Consonni, Dario; Zrafi, Ines; Saidane-Mosbahi, Dalila; Fustinoni, Silvia

    2016-07-01

    Occupational exposures during iron and steel founding have been classified as carcinogenic to humans, and the exposure to polycyclic aromatic hydrocarbons (PAHs) in this industrial setting may contribute to cancer risk. The occupational exposure to PAHs was assessed in 93 male workers at an electric steel foundry in Tunisia by biomonitoring, with the aims of characterizing the excretion profile and investigating the influence of job title and personal characteristics on the biomarkers. Sixteen 2-6 ring unmetabolized PAHs (U-PAHs) and eight hydroxylated PAH metabolites (OHPAHs) were analyzed by gas chromatography-triple quadrupole tandem mass spectrometry and liquid chromatography triple quadrupole tandem mass spectrometry, respectively. Among U-PAHs, urinary naphthalene (U-NAP) was the most abundant compound (median level: 643ng l(-1)), followed by phenanthrene (U-PHE, 18.5ng l(-1)). Urinary benzo[a]pyrene (U-BaP) level was <0.30ng l(-1) Among OHPAHs, 2-hydroxynaphthalene (2-OHNAP) was the most abundant metabolite (2.27 µg l(-1)). Median 1-hydroxypyrene (1-OHPYR) was 0.52 µg l(-1) Significant correlations among urinary biomarkers were observed, with Pearson's r ranging from 0.177 to 0.626. 1-OHPYR was correlated to benzo[a]pyrene, but not to five- and six-rings PAHs. A multiple linear regression model showed that job title was a significant determinant for almost all U-PAHs. In particular, employees in the steel smelter workshop had higher levels of high-boiling U-PAHs and lower levels of low-boiling U-PAHs than those of workers with other job titles. Among OHPAHs, this model was significant only for naphthols and 1-hydroxyphenanthrene (1-OHPHE). Smoking status was a significant predictor for almost all biomarkers. Among all analytes, U-PHE and 1-OHPHE were the less affected by tobacco smoke, and they were significantly correlated with both low- and high-molecular-weight compounds, and their levels were related to job titles, so they could be proposed as suitable

  18. Evaluation of ambient air concentrations of polycyclic aromatic hydrocarbons in Germany from 1990 to 1998.

    Science.gov (United States)

    Fertmann, Regina; Tesseraux, Irene; Schümann, Michael; Neus, Hermann

    2002-03-01

    All available polycyclic aromatic hydrocarbon (PAH) concentration data in ambient air obtained over the past 10 years in Germany were evaluated to clarify whether it is justified to use benzo(a)pyrene (BaP) as a marker compound for the total PAH exposure. The data basis comprises annual mean concentrations from 1990 to 1998 supplied by the emission protection authorities of the federal states with additional information on the region, year and site of measurement. The data are very heterogeneous with respect to sample size, the number of individual PAHs analyzed, place of origin and year. Nine of 25 individual compounds with sufficient sample size (74German reunion and time characterize the distributive patterns, e.g., from 1991 to 1997, a significant decrease in BaP could be determined based on the data from North Rhine-Westphalia (1991, N=51, median 1.6 ng/m(3); 1997, N=45, median 0.7 ng/m(3); P

  19. Biosurfactant produced by novel Pseudomonas sp. WJ6 with biodegradation of n-alkanes and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Xia, Wenjie; Du, Zhifeng; Cui, Qingfeng; Dong, Hao; Wang, Fuyi; He, Panqing; Tang, YongChun

    2014-07-15

    Alkanes and polycyclic aromatic hydrocarbons (PAHs) have threatened the environment due to toxicity and poor bioavailability. Interest in degradation of these hazardous materials by biosurfactant-producing bacteria has been steadily increasing in recent years. In this work, a novel biosurfactant-producing Pseudomonas sp. WJ6 was isolated to degrade a wide range of n-alkanes and polycyclic aromatic hydrocarbons. Production of lipopeptide biosurfactant was observed in all biodegradable studies. These lipopeptides were purified and identified by C18 RP-HPLC system and electrospray ionization-mass spectrometry. Results of structural analysis showed that these lipopeptides generated from different hydrocarbons were classified to be surfactin, fengycin and lichenysin. Heavy-oil sludge washing experiments demonstrated that lipopeptides produced by Pseudomonas sp. WJ6 have 92.46% of heavy-oil washing efficiency. The obtained results indicate that this novel bacterial strain and its lipopeptides have great potentials in the environmental remediation and petroleum recovery.

  20. Determination of hydroxylated polycyclic aromatic hydrocarbons by HPLC-photoionization tandem mass spectrometry in wood smoke particles and soil samples.

    Science.gov (United States)

    Avagyan, Rozanna; Nyström, Robin; Boman, Christoffer; Westerholm, Roger

    2015-06-01

    A simple and fast method for analysis of hydroxylated polycyclic aromatic hydrocarbons using pressurized liquid extraction and high performance liquid chromatography utilizing photoionization tandem mass spectrometry was developed. Simultaneous separation and determination of nine hydroxylated polycyclic aromatic hydrocarbons and two hydroxy biphenyls could be performed in negative mode with a run time of 12 min, including equilibration in 5 min. The calibration curves were in two concentration ranges; 1-50 ng/mL and 0.01-50 μg/mL, with coefficients of correlation R (2) > 0.997. The limits of detection and method quantification limits were in the range of 9-56 pg and 5-38 ng/g, respectively. A two-level full factorial experimental design was used for screening of conditions with the highest impact on the extraction. The extraction procedure was automated and suitable for a large number of samples. The extraction recoveries ranged from 70 to 102 % and the matrix effects were between 92 and 104 %. The overall method was demonstrated on wood smoke particles and soil samples with good analytical performance, and five OH-PAHs were determined in the concentration range of 0.19-210 μg/g. As far as we know, hydroxylated polycyclic aromatic hydrocarbons were determined in wood smoke and soil samples using photoionization mass spectrometry for the first time in this present study. Accordingly, this study shows that high performance liquid chromatography photoionization tandem mass spectrometry can be a good option for the determination of hydroxylated polycyclic aromatic hydrocarbons in complex environmental samples. Graphical Abstract The method developed in this study was used to determine hydroxylated polycyclic aromatic hydrocarbons in wood smoke and soil.

  1. 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.

  2. 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.

  3. Polycyclic aromatic hydrocarbons in sediments and mussels of the western Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Baumard, P.; Budzinski, H.; Garrigues, P. [Univ. Bordeaux I, Talence (France)

    1998-05-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in superficial sediments and mussels (Mytilus galloprovincialis) of the western Mediterranean sea. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). The PAH concentrations ranged from 1 to 20,500 ng/g in the sediments. Different molecular indices allowed differentiation between the different pollutant sources. On the French coast, PAHs originated mainly from incomplete combustion of organic matter (pyrolytic origin), whereas for some sites in Corsica and Sardinia an overimposition of petrogenic PAHs occurred. The mussel PAH concentrations ranged from 25 to 390 ng/g. The total and individual PAH bioaccumulation factors were calculated. The correlation between sediment and mussel PAH content was discussed in terms of bioavailability. It was possible to distinguish different absorption routes for the xenobiotics according to their physicochemical properties. Because the mussel distribution of phenanthrene and anthracene seems to be governed by their water solubility, these compounds were probably mainly absorbed as the water-dissolved form, whereas the heavier molecular weight PAHs (more than four aromatic rings), whose sediment and mussel concentrations are correlated with higher correlation coefficients than for phenanthrene and anthracene, were probably mainly absorbed as adsorbed on particles. Furthermore, a possible preferential biotransformation of benzo[a]pyrene over benzo[e]pyrene is discussed.

  4. Vapor pressures and sublimation enthalpies of seven heteroatomic aromatic hydrocarbons measured using the Knudsen effusion technique.

    Science.gov (United States)

    Goldfarb, Jillian L; Suuberg, Eric M

    2010-06-01

    The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) grams plus sign in circlemol(-1) were measured over the temperature range of (301 to 486) Kelvin 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.

  5. 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.

  6. 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

  7. Physico-chemical properties and toxicity of alkylated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kang, Hyun-Joong; Lee, So-Young; Kwon, Jung-Hwan

    2016-07-15

    Crude oil and refined petroleum products contain many polycyclic and heterocyclic aromatic hydrocarbons, in particular, alkylated PAHs. Although alkylated PAHs are found in significantly higher quantities than their corresponding unsubstituted PAHs, the most studies on the physico-chemical properties and toxicities of these compounds have been conducted on unsubstituted PAHs. In this study, we measured crucial physico-chemical properties (i.e., water solubility, partition coefficients between polydimethylsiloxane and water (KPDMSw), and partition coefficient between liposomes and water (Klipw)) of selected alkylated PAHs, and evaluated their toxicity using the luminescence inhibition of Aliivibrio fischeri and growth inhibition of Raphidocelis subcapitata. In general, the logarithms of these properties for alkylated PAHs showed good linear correlations with log Kow, as did those for unsubstituted PAHs. Changes in molecular symmetry on the introduction of alkyl groups on aromatic ring structure significantly altered water solubility. The inhibition of bacterial luminescence and algal growth by alkylated PAHs can be explained well by the baseline toxicity hypothesis, and good linear relationships between log Kow or log Klipw and log (1/EC50) were found.

  8. Formation of polycyclic aromatic hydrocarbons from acetylene over nanosized olivine-type silicates.

    Science.gov (United States)

    Tian, M; Liu, B S; Hammonds, M; Wang, N; Sarre, P J; Cheung, A S-C

    2012-05-14

    The formation mechanism of polycyclic aromatic hydrocarbon (PAH) molecules in interstellar and circumstellar environments is not well understood although the presence of these molecules is widely accepted. In this paper, addition and aromatization reactions of acetylene over astrophysically relevant nesosilicate particles are reported. Gas-phase PAHs produced from exposure of acetylene gas to crystalline silicates using pulsed supersonic jet expansion (SJE) conditions were detected by time-of-flight mass spectrometry (TOF-MS). The PAHs produced were further confirmed in a separate experiment using a continuous flow fixed-bed reactor in which acetylene was introduced at atmospheric pressure. The gas-phase effluent and solutions of the carbonaceous compounds deposited on the nesosilicate particles were analyzed using gas chromatography-mass spectrometry (GC-MS). A mechanism for PAH formation is proposed in which the Mg(2+) ions in the nesosilicate particles act as Lewis acid sites for the acetylene reactions. Our studies indicate that the formation of PAHs in mixed-chemistry astrophysical environments could arise from acetylene interacting with olivine nano-particles. These nesosilicate particles are capable of providing catalytic centres for adsorption and activation of acetylene molecules that are present in the circumstellar environments of mass-losing carbon stars. The structure and physical properties of the particles were characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and high-resolution transmission electron microscopy (HRTEM) techniques.

  9. Evaluation of sampling devices for the determination of polycyclic aromatic hydrocarbons in surface microlayer coastal waters.

    Science.gov (United States)

    Guitart, C; García-Flor, N; Dachs, J; Bayona, J M; Albaigés, J

    2004-05-01

    The sea surface microlayer (SML) may play an important role on the transport and fate of persistent organic pollutants in the marine environment. In order to evaluate the appropriateness of a number of sampling devices for the analysis of 14 parent polycyclic aromatic hydrocarbons (3-5 aromatic rings), marine SML waters were sampled using a glass plate, a rotating drum/roller, a metal screen and a surface slick sampler. The underlying waters were also sampled for the determination of the corresponding enrichment factors (EF = [C](microlayer)/[C](underlying water)). The EFs were phase dependent, ranging from 1 to 3 for the dissolved phase and between 4 and 7 for the particulate phase. In order to better assess the performance of the different sampling methods, in terms of phase partitioning, the truly dissolved and colloidal phases were also estimated. Generally, no significant differences were found for the enrichment factors provided by the different methods, due to the observed large variability in concentrations that can be attributed to small-scale coastal processes. However, the metal screen is recommended as the most efficient sampling method for the study of PAHs taking into account the amount of water collected versus time.

  10. 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.

  11. Simultaneous biodegradation of creosote-polycyclic aromatic hydrocarbons by a pyrene-degrading Mycobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Z.; Vila, J.; Grifoll, M. [Barcelona Univ. (Spain). Dept. de Microbiologia; Ortega-Calvo, J.J. [C.S.I.C., Seville (Spain). Inst. de Recursos Naturales y Agrobiologia

    2008-02-15

    When incubated with a creosote-polycyclic aromatic hydrocarbons (PAHs) mixture, the pyrene-degrading strain Mycobacterium sp. AP1 acted on three- and four-ring components, causing the simultaneous depletion of 25% of the total PAHs in 30 days. The kinetics of disappearance of individual PAHs was consistent with differences in aqueous solubility. During the incubation, a number of acid metabolites indicative of distinctive reactions carried out by high-molecular-weight PAH-degrading mycobacteria accumulated in the medium. Most of these metabolites were dicarboxylic aromatic acids formed as a result of the utilization of growth substrates (phenanthrene, pyrene, or fluoranthene) by multibranched pathways including meta- and ortho-ring-cleavage reactions: phthalic acid, naphthalene-1,8-dicarboxylic acid, phenanthrene-4,5-dicarboxylic acid, diphenic acid, Z-9-carboxymethylenefluorene-1-carboxylic acid, and 6,6'-dihydroxy-2,2'-biphenyl dicarboxylic acid. Others were dead-end products resulting from cometabolic oxidations on nongrowth substrates (fluorene meta-cleavage product). These results contribute to the general knowledge of the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted soils. The identification of the partially oxidized compounds will facilitate to develop analytical methods to determine their potential formation and accumulation in contaminated sites. (orig.)

  12. High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons: The Realm of Anharmonicity

    Science.gov (United States)

    Maltseva, Elena; Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

    2016-01-01

    We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micrometers CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold ((is) approximately 4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main modes that fall within 0.5% of the experimental frequencies. The implications for the Aromatic Infrared Bands, specifically the 3-m band are discussed.

  13. Random mixtures of polycyclic aromatic hydrocarbon spectra match interstellar infrared emission

    CERN Document Server

    Rosenberg, Marissa J F; Boersma, Christiaan

    2014-01-01

    The mid-infrared (IR; 5-15~$\\mu$m) spectrum of a wide variety of astronomical objects exhibits a set of broad emission features at 6.2, 7.7, 8.6, 11.3 and 12.7 $\\mu$m. About 30 years ago it was proposed that these signatures are due to emission from a family of UV heated nanometer-sized carbonaceous molecules known as polycyclic aromatic hydrocarbons (PAHs), causing them to be referred to as aromatic IR bands (AIBs). Today, the acceptance of the PAH model is far from settled, as the identification of a single PAH in space has not yet been successful and physically relevant theoretical models involving ``true'' PAH cross sections do not reproduce the AIBs in detail. In this paper, we use the NASA Ames PAH IR Spectroscopic Database, which contains over 500 quantum-computed spectra, in conjunction with a simple emission model, to show that the spectrum produced by any random mixture of at least 30 PAHs converges to the same 'kernel'-spectrum. This kernel-spectrum captures the essence of the PAH emission spectrum...

  14. Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions.

    Science.gov (United States)

    Zhou, Hui; Wu, Chunfei; Onwudili, Jude A; Meng, Aihong; Zhang, Yanguo; Williams, Paul T

    2015-02-01

    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.

  15. Conversion of heavy aromatic hydrocarbons to valuable synthetic feed for steamcrackers

    Energy Technology Data Exchange (ETDEWEB)

    Cesana, A.; Dalloro, L.; Rivetti, F.; Buzzoni, R.; Bignazzi, R. [ENI S.p.A., Novara (Italy). Refining and Marketing Div.

    2007-07-01

    The scope of the present study was upgrading a set of heavy aromatic hydrocarbons mixtures whose commercial value ranks close to fuel oil and should become even lower in the next future because of the introduction of more stringent regulations on fuels, through hydro-conversion to a synthetic feed for steam-cracking. The resulting process provides an opportunity to improve the economic return of a steamcracking plant, offering the chance of converting low-value mixtures produced by the plant itself, such as fuel oil of cracking (FOK), saving an equivalent amount of naphtha. The method can also be used for converting pyrolysis gasoline (pygas). Although pygas has at present a fair commercial value, it could suffer a significant penalization in the future due to further limitations on total aromatic content in gasoline. Pygas hydro-conversion to a synthetic steam-cracking feedstock has been recently reported. Fractions from refinery, such as heavy distillates (e.g. Heavy Vacuum Gas Oil, VGO), deasphalted resides (DAO), or some FCC streams (e.g. LCO) resulted suitable and very attractive mixtures to be treated as well. No more than deasphalting was required as pretreatment of the feed mixture and only when the asphalts were >2%. Hetero-elements are often present in such kind of feeds at quite high concentrations, but no problems were observed due to the presence of sulphur and nitrogen, respectively, up to 15000 and 5500 ppm. (orig.)

  16. Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hui [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Energy Research Institute, University of Leeds, Leeds LS2 9JT (United Kingdom); Wu, Chunfei, E-mail: c.wu@leeds.ac.uk [Energy Research Institute, University of Leeds, Leeds LS2 9JT (United Kingdom); Onwudili, Jude A. [Energy Research Institute, University of Leeds, Leeds LS2 9JT (United Kingdom); Meng, Aihong [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Zhang, Yanguo, E-mail: zhangyg@tsinghua.edu.cn [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Williams, Paul T., E-mail: p.t.williams@leeds.ac.uk [Energy Research Institute, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-02-15

    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.

  17. Tumour-promoting activity of polycyclic aromatic hydrocarbons and their oxygenated or nitrated derivatives.

    Science.gov (United States)

    Misaki, Kentaro; Takamura-Enya, Takeji; Ogawa, Hideoki; Takamori, Kenji; Yanagida, Mitsuaki

    2016-03-01

    Various types of polycyclic aromatic compounds (PACs) in diesel exhaust particles are thought to contribute to carcinogenesis in mammals. Although the carcinogenicity, mutagenicity and tumour-initiating activity of these compounds have been evaluated, their tumour-promoting activity is unclear. In the present study, to determine the tumour-inducing activity of PACs, including previously known mutagenic compounds in atmospheric environments, a transformation assay for promoting activity mediated by the release of contact inhibition was conducted for six polycyclic aromatic hydrocarbons (PAHs), seven oxygenated PAHs (oxy-PAHs) and seven nitrated PAHs (nitro-PAHs) using mouse embryonic fibroblast cells transfected with the v-Ha-ras gene (Bhas 42 cells). Of these, two PAHs [benzo[k]fluoranthene (B[k]FA) and benzo[b]fluoranthene (B[b]FA)], one oxy-PAH [6H-benzo[cd]pyren-6-one (BPO)] and two nitro-PAHs (3-nitro-7H-benz[de]anthracen-7-one and 6-nitrochrysene) were found to exhibit particularly powerful tumour-promoting activity (≥10 foci following exposure to BPO). Further, an HO-1 antioxidant response activation was observed following exposure to B[k]FA, B[b]FA and BPO, suggesting that the induction of tumour-promoting activity in these compounds is correlated with the dysfunction of signal transduction via AhR-mediated responses and/or oxidative stress responses.

  18. Polycyclic aromatic hydrocarbon-degrading bacteria from aviation fuel spill site at Ibeno, Nigeria.

    Science.gov (United States)

    John, R C; Essien, J P; Akpan, S B; Okpokwasili, G C

    2012-06-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were isolated from aviation fuel contaminated soil at Inua Eyet Ikot in Ibeno, Nigeria. PAH-degrading bacteria in the contaminated soil were isolated by enrichment culture technique. Isolates with high PAH degrading potential characterized by their extensive growth on PAH-supplemented minimal salt medium were screened for their naphthalene, phenanthrene and chrysene degradability. The screening medium which contained selected PAHs as the sole source of carbon and energy showed that Micrococcus varians AFS-2, Pseudomonas putida AFS-3 and Alcaligenes faecalis AFS-5 exhibited a concentration-dependent growth in all the PAH-compounds tested. There were visible changes in the color of growth medium suggesting the production of different metabolites. Their acclimation to different PAH substrates was also evident as A. faecalis AFS-5 isolated from chrysene grew well on other less complex aromatic compounds. The isolate exhibited best growth (0.44 OD(600)) when exposed to 10 ppm of chrysene for 5 days and could utilize up to 90 ppm of chrysene. This isolate and others with strong PAH-degrading potentials are recommended for bioremediation of PAHs in aviation fuel-contaminated sites in the tropics.

  19. HIGH-RESOLUTION IR ABSORPTION SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS: THE REALM OF ANHARMONICITY

    Energy Technology Data Exchange (ETDEWEB)

    Maltseva, Elena; Buma, Wybren Jan [University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Tielens, Alexander G. G. M. [Leiden Observatory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Huang, Xinchuan; Lee, Timothy J. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Oomens, Jos, E-mail: w.j.buma@uva.nl, E-mail: petrignani@strw.leidenuniv.nl [Radboud University, Toernooiveld 7, 6525 ED Nijmegen (Netherlands)

    2015-11-20

    We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3-μm CH stretching region of polycyclic aromatic hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (∼4 K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main bands that fall within 0.5% of the experimental frequencies. The implications for the aromatic infrared bands, specifically the 3-μm band, are discussed.

  20. Release behavior and formation mechanism of polycyclic aromatic hydrocarbons during coal pyrolysis.

    Science.gov (United States)

    Gao, Meiqi; Wang, Yulong; Dong, Jie; Li, Fan; Xie, Kechang

    2016-09-01

    Polycyclic aromatic hydrocarbons (PAHs) are major environmental pollutants. They have attracted considerable attention due to their severe potential carcinogenic, mutagenic and genotoxic effects on human health. In this study, five different rank coals from China were pyrolyzed using pyro-probe CDS 5250 and the release behavior of 16 PAHs under different pyrolysis conditions were studied by Gas Chromatography-Mass Spectrometer (GC-MS). The structural characteristics of the five coals were determined by Cross-Polarization/Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS (13)C NMR) spectroscopy, and then the factors influencing the formation of PAHs during coal pyrolysis were discussed together with the coal structural data. It was shown that the amount of PAHs generated during coal pyrolysis was largely related to coal rank and followed the order of medium metamorphic coal > low metamorphic coal > high metamorphic coal. The amount of total PAHs varied as the temperature was increased from 400 °C to 1200 °C, which showed a trend of first increasing and then decreasing, with the maximum value at 800 °C. Moreover, the species of PAHs released varied with pyrolysis temperatures. When the temperature was lower than 800 °C, the small ring PAHs were the most abundant, while the proportion of heavy rings increased at higher temperature. The results indicate that the formation of PAHs during coal pyrolysis depends on the structure of the coal. The species and amounts of PAHs generated during coal pyrolysis are closely related to the contents of protonated aromatic carbons and bridging ring junction aromatic carbons present in the coal structure.