WorldWideScience

Sample records for azaarenes

  1. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    International Nuclear Information System (INIS)

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. - Highlights: • We compare PAH and azaarene concentrations in runoff from coal-tar- and asphalt-sealed pavement. • Concentrations in coal-tar-sealcoat runoff greatly exceeded those in asphalt-sealcoat runoff. • Decreases in azaarenes and LMW PAHs were offset by increases in HMW PAHs. • PAH concentrations in coal-tar-sealcoat runoff remained high for months after application. - Concentrations of PAHs in runoff from pavement with coal-tar-based sealcoat continue to be elevated for at least 3 months following sealcoat application

  2. Biodegradation of azaarenes and creosote in aqueous and organic liquid phase immobilized cell bioreactors by bacteria isolated from creosote contaminated soil

    International Nuclear Information System (INIS)

    The biodegradation of azaarenes and coal-tar creosote was studied using aerobic bacteria isolated from creosote contaminated soil as inocula in batch cultures and in immobilized cell bioreactors. Biodegradation of quinoline, isoquinoline, and 6-methylquinoline by pure and mixed cultures yielded mono-hydroxylated metabolites as the primary products of azaarene metabolism. All azaarene degrading cultures could degrade quinoline, suggesting a common metabolic pathway based on quinoline metabolism. Mixed cultures attacking creosote degraded 2- and 3-ring polyaromatic hydrocarbons and heterocycles, but were unable to degrade 4- and 5-ring PAH. The degradation rate and loading capacity for quinoline was greatly enhanced in the bioreactors in comparison to batch cultures. The rates of isoquinoline, 6-methylquinoline degrading strain of Pseudomonas putida successfully removed 6-methylquinoline from solution in decane in a water-limited, non-aqueous liquid phase immobilized cell bioreactor. These experiments demonstrate the ability of environmental organisms to biodegrade several biologically active compounds under conditions suitable for bioremediation applications

  3. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  4. Occurrence, distribution and health risk from polycyclic aromatic compounds (PAHs, oxygenated-PAHs and azaarenes) in street dust from a major West African Metropolis.

    Science.gov (United States)

    Bandowe, Benjamin A Musa; Nkansah, Marian Asantewah

    2016-05-15

    Scientific evidence suggests that the burden of disease on urban residents of sub-Saharan African Countries is increasing, partly as a result of exposure to elevated concentrations of toxic environmental chemicals. However, characterization of the levels, composition pattern and sources of polycyclic aromatic compounds (PACs) in environmental samples from African cities is still lacking. This study measured the PAHs, oxygenated-PAHs (OPAHs) and azaarene (AZAs) content of street dusts collected from Kumasi, Ghana (a major metropolis located in the tropical forest zone of West Africa). The ∑Alkyl+parent-PAHs, ∑OPAHs and ∑AZAs concentration in street dust averaged 2570ngg(-1) (range: 181-7600ngg(-1)), 833ngg(-1) (57-4200ngg(-1)) and 73ngg(-1) (3.3-240ngg(-1)), respectively. The concentrations of ∑Alkyl+parent-PAHs were strongly correlated (n=25) with ∑OPAHs (r=0.96, psoils from same city, demonstrating the high influence of traffic emissions. Several individual OPAHs and AZAs had higher concentrations than their related and often monitored parent-PAHs. The estimated incremental lifetime cancer risks due to the parent-PAHs in street dusts was >10(-6) indicating high risk of contracting cancer from exposure to street dust from Kumasi. The contribution of OPAHs, AZAs, and alkyl-PAHs in street dust to cancer risk could not be quantified because of lack of toxicity equivalency factors for these compounds; however this could be significant because of their high concentration and known higher toxicity of some polar PACs and alkyl-PAHs than their related parent-PAHs. PMID:26930316

  5. Oxygenated polycyclic aromatic hydrocarbons and azaarenes in urban soils: a comparison of a tropical city (Bangkok) with two temperate cities (Bratislava and Gothenburg).

    Science.gov (United States)

    Bandowe, Benjamin A Musa; Lueso, María Gómez; Wilcke, Wolfgang

    2014-07-01

    Environmental conditions in the tropics favor the formation of polar polycyclic aromatic compound (polar PACs, such as oxygenated PAHs [OPAHs] and azaarenes [AZAs]), but little is known about these hazardous compounds in tropical soils. The objectives of this work were to determine (i) the level of contamination of soils (0-5 and 5-10 cm layers) from the tropical metropolis of Bangkok (Thailand) with OPAHs and AZAs and (ii) the influence of urban emission sources and soil properties on the distribution of PACs. We hypothesized that the higher solar insolation and microbial activity in the tropics than in the temperate zone will lead to enhanced secondary formation of OPAHs. Hence, OPAH to related parent-PAH ratios will be higher in the tropical soils of Bangkok than in temperate soils of Bratislava and Gothenburg. The concentrations of ∑15OPAHs (range: 12-269 ng g(-1)) and ∑4AZAs (0.1-31 ng g(-1)) measured in soils of Bangkok were lower than those in several cities of the industrialized temperate zone. The ∑15OPAHs (r=0.86, pPAHs highlighting similar sources and related fate. The octanol-water partition coefficient did not explain the transport to the subsoil, indicating soil mixing as the reason for the polar PAC load of the lower soil layer. Data on PAC concentrations in soils of Bratislava and Gothenburg were taken from published literature. The individual OPAH to parent-PAH ratios in soils of Bangkok were mostly higher than those of Bratislava and Gothenburg (e.g. 9-fluorenone/fluorene concentration ratio was 12.2 ± 6.7, 5.6 ± 2.4, and 0.7 ± 02 in Bangkok, Bratislava and Gothenburg soils, respectively) supporting the view that tropical environmental conditions and higher microbial activity likely lead to higher OPAH to parent-PAH ratios in tropical than in temperate soils. PMID:24529396

  6. Determination of basic azaarenes and polynuclear aromatic hydrocarbons in airborne particulate matter by gas chromatography

    DEFF Research Database (Denmark)

    Nielsen, Torben; Clausen, Peraxel; Jensen, Finn Palmgren

    1986-01-01

    phase (adjusted to pH 14 with potassium hydroxide) with dichloromethane, and determined by capillary gas chromatography (g.c.) with a nitrogen-sensitive detector. The PAH in the toluene phase are isolated by means of semipreparative high-performance liquid chromatography and liquid-liquid extraction and...

  7. Synthetic Fuels Program

    International Nuclear Information System (INIS)

    Studies on waste water derived from synthetic fuel processes included acute toxicity of coal conversion effluent components and acute toxicity of aqueous waste and wastewater components of the ORNL Bench-Scale hydrocarbonization process. The potential hazards of synthetic fuels technology development to terrestrial ecosystems were studied with regard to toxicity of PAH and azaarenes. Aquatic transport studies included the following: aquatic transport of PAH and rates of PAH photolysis at the Bethlehem, Pennsylvania, coking plant site; microbial transformations of polycyclic aromatic hydrocarbons in water and sediment samples; persistence of azaarenes in aquatic systems; bioaccumulation of pathways of azaarenes; sorption of PAH to suspended particles in natural waters; and transport and fate of anthracene in pond microcosms. Studies were also conducted on environmental characterization of solid waste from a Lurgi facility

  8. Microbial conversions of nitrogenous heterocycles

    OpenAIRE

    Parshikov, Igor A

    2015-01-01

    The monography describes examples of the application of microbial technologies for obtaining of derivatives from a series of nitrogen heterocycles (saturated nitrogen heterocycles, azaarenes and quinolones). It is proposed alternative ways for synthesize substances that are difficult to obtain by the methods of organic chemistry. Microbial technologies of synthesis of organic compounds may find out a practical application in the production of various drugs.

  9. Development and application of a solidphase extraction method for simultaneousdetermination of PAHs, oxy-PAHs andazaarenes in water samples

    OpenAIRE

    WANG Yu

    2012-01-01

    In this study, a solid phase extraction (SPE) method was developed that can be used to extract a wide range of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (oxy-PAHs) and azaarenes, from water samples. Three commercially available SPE materials, i.e. Oasis HLB, ISOLUTE C2/C18 (EC) and ISOLUTE PAH, were tested for their capability to accomplish the extraction, and two were chosen for further optimization. Several different combination...

  10. Synthetic Strategies for 5- and 6-Membered Ring Azaheterocycles Facilitated by Iminyl Radicals.

    Science.gov (United States)

    Walton, John C

    2016-01-01

    The totality of chemical space is so immense that only a small fraction can ever be explored. Computational searching has indicated that bioactivity is associated with a comparatively small number of ring-containing structures. Pyrrole, indole, pyridine, quinoline, quinazoline and related 6-membered ring-containing aza-arenes figure prominently. This review focuses on the search for fast, efficient and environmentally friendly preparative methods for these rings with specific emphasis on iminyl radical-mediated procedures. Oxime derivatives, particularly oxime esters and oxime ethers, are attractive precursors for these radicals. Their use is described in conventional thermolytic, microwave-assisted and UV-vis based preparative procedures. Photoredox-catalyzed protocols involving designer oxime ethers are also covered. Choice can be made amongst these synthetic strategies for a wide variety of 5- and 6-membered ring heterocycles including phenanthridine and related aza-arenes. Applications to selected natural products and bioactive molecules, including trispheridine, vasconine, luotonin A and rutaecarpine, are included. PMID:27213311

  11. Biotransformations of organic compounds mediated by cultures of Aspergillus niger.

    Science.gov (United States)

    Parshikov, Igor A; Woodling, Kellie A; Sutherland, John B

    2015-09-01

    Many different organic compounds may be converted by microbial biotransformation to high-value products for the chemical and pharmaceutical industries. This review summarizes the use of strains of Aspergillus niger, a well-known filamentous fungus used in numerous biotechnological processes, for biochemical transformations of organic compounds. The substrates transformed include monocyclic, bicyclic, and polycyclic aromatic hydrocarbons; azaarenes, epoxides, chlorinated hydrocarbons, and other aliphatic and aromatic compounds. The types of reactions performed by A. niger, although not unique to this species, are extremely diverse. They include hydroxylation, oxidation of various functional groups, reduction of double bonds, demethylation, sulfation, epoxide hydrolysis, dechlorination, ring cleavage, and conjugation. Some of the products may be useful as new investigational drugs or chemical intermediates. PMID:26162670

  12. Determination of polycyclic aromatic compounds and heavy metals in sludges from biological sewage treatment plants.

    Science.gov (United States)

    Bodzek, D; Janoszka, B; Dobosz, C; Warzecha, L; Bodzek, M

    1997-07-11

    The procedure of the analysis of polycyclic aromatic hydrocarbons (PAHs) and their derivatives in the sludges from biological sewage treatment plants has been worked out. The analysis included isolation of organic matter from sludges, separation of the extract into fractions of similar chemical character, qualitative-quantitative analysis of individual PAHs and their nitrogenated and oxygenated derivatives. Liquid-solid chromatography, solid-phase extraction and semipreparative band thin-layer chromatography techniques were used for the separation. Capillary gas chromatography-mass spectrometry analysis of the separated fractions enabled identification of more than 21 PAHs, including hydrocarbons which contained 2-6 aromatic rings as well as their alkyl derivatives, 10 oxygen derivatives, 9 nitroarenes, aminoarenes and over 20 azaarenes and carbazoles. Using the capillary gas chromatography-flame ionization detection technique the content of 17 dominant PAHs was determined. The content of heavy metals was determined in investigated sludges with the use of atomic absorption spectrometry. The concentrations of the respective metals could be ranked in the order Cd coal mine wastes, taking into consideration the contents of toxic organic pollutants and heavy metals. PMID:9253190

  13. Identification of sulfur heterocycles in coal liquids and shale oils. Technical progress report, August 1, 1980-May 1, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. L.; Castle, R. N.

    1981-01-01

    The sulfur heterocycle separation scheme which was described in the last progress report was evaluated for quantitative recovery of individual components. The results indicate that recoveries can range from 10% to approx. 30% depending on the structure of the compound. During this period, 23 unsubstituted sulfur-containing heterocyclic ring systems were synthesized in oder to confirm GC/MS identifications and for biological testing. The four possible 3-ring heterocycles and the thirteen possible 4-ring heterocycles were tested for mutagenic activity in the histidine reversion (Ames assay) system. One of the 3-ring isomers, naphtho(1,2-b)-thiophene, and six of the 4-ring isomers induced mutations in Salmonella test strains. One of these compounds, phenanthro(3,4-b)thiophene, displayed approximately the same mutagenic activity as benzo(a)pyrene. A two-step adsorption chromatographic procedure was developed in order to fractionate synthetic fuels into various chemical-type classes for studying the relative concentrations and mutagenic activities of the various types. An SRC-II Heavy Distillate was fractionated into aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, sulfur heterocycles, indoles and carbazoles, azaarenes, and amino polycyclic aromatic hydrocarbons. It was found that the amino-PAH fraction contained most of the mutagenic activity. A survey was made for compounds containing both nitrogen and sulfur heteroatoms in their structures. A number of these compounds were detected by GC using nitrogen- and sulfur-selective detection.

  14. Occurrence, gas/particle partitioning and carcinogenic risk of polycyclic aromatic hydrocarbons and their oxygen and nitrogen containing derivatives in Xi'an, central China

    International Nuclear Information System (INIS)

    29 parent- and alkyl-polycyclic aromatic hydrocarbons (PAHs), 15 oxygenated-PAHs (OPAHs), 11 nitrated-PAHs (NPAHs) and 4 azaarenes (AZAs) in both the gaseous and particulate phases, as well as the particulate-bound carbon fractions (organic carbon, elemental carbon, char, and soot) in ambient air sampled in March and September 2012 from an urban site in Xi'an, central China were extracted and analyzed. The average concentrations (gaseous + particulate) of ∑ 29PAHs, ∑ 15OPAHs, ∑ 11NPAHs and ∑ 4AZAs were 1267.0 ± 307.5, 113.8 ± 46.1, 11.8 ± 4.8 and 26.5 ± 11.8 ng m−3 in March and 784.7 ± 165.1, 67.2 ± 9.8, 9.0 ± 1.5 and 21.6 ± 5.1 ng m−3 in September, respectively. Concentrations of ∑ 29PAHs, ∑ 15OPAHs and ∑ 11NPAHs in particulates were significantly correlated with those of the carbon fractions (OC, EC, char and soot). Both absorption into organic matter in particles and adsorption onto the surface of particles were important for PAHs and OPAHs in both sampling periods, with more absorption occurring in September, while absorption was always the most important process for NPAHs. The total carcinogenic risk of PAHs plus the NPAHs was higher in March. Gaseous compounds, which were not considered in most previous studies, contributed 29 to 44% of the total health risk in March and September, respectively. - Highlights: • Gaseous and particulate PAHs, OPAHs, NPAHs and AZAs were measured at Xi’an. • ∑29PAHs were 1 to 2 orders of magnitude higher than ∑15OPAHs, ∑11NPAHs and ∑4AZAs. • MW can predict phase partitioning and more absorption occurred in September. • Gaseous PACs contributed 29 − 44% of total cancer risk

  15. Occurrence, gas/particle partitioning and carcinogenic risk of polycyclic aromatic hydrocarbons and their oxygen and nitrogen containing derivatives in Xi'an, central China

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Chong [Key Laboratory of Aerosol Chemistry and Physics (KLACP), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); Geographic Institute, University of Berne, Hallerstrasse 12, 3012 Berne (Switzerland); State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Han, Yongming, E-mail: yongming@ieecas.cn [Key Laboratory of Aerosol Chemistry and Physics (KLACP), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); Bandowe, Benjamin A. Musa [Geographic Institute, University of Berne, Hallerstrasse 12, 3012 Berne (Switzerland); Cao, Junji [Key Laboratory of Aerosol Chemistry and Physics (KLACP), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); Institute of Global Environmental Change, Xi' an Jiaotong University, Xi' an 710049 (China); Huang, Ru-Jin [Key Laboratory of Aerosol Chemistry and Physics (KLACP), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Ni, Haiyan; Tian, Jie [Key Laboratory of Aerosol Chemistry and Physics (KLACP), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); and others

    2015-02-01

    29 parent- and alkyl-polycyclic aromatic hydrocarbons (PAHs), 15 oxygenated-PAHs (OPAHs), 11 nitrated-PAHs (NPAHs) and 4 azaarenes (AZAs) in both the gaseous and particulate phases, as well as the particulate-bound carbon fractions (organic carbon, elemental carbon, char, and soot) in ambient air sampled in March and September 2012 from an urban site in Xi'an, central China were extracted and analyzed. The average concentrations (gaseous + particulate) of ∑ 29PAHs, ∑ 15OPAHs, ∑ 11NPAHs and ∑ 4AZAs were 1267.0 ± 307.5, 113.8 ± 46.1, 11.8 ± 4.8 and 26.5 ± 11.8 ng m{sup −3} in March and 784.7 ± 165.1, 67.2 ± 9.8, 9.0 ± 1.5 and 21.6 ± 5.1 ng m{sup −3} in September, respectively. Concentrations of ∑ 29PAHs, ∑ 15OPAHs and ∑ 11NPAHs in particulates were significantly correlated with those of the carbon fractions (OC, EC, char and soot). Both absorption into organic matter in particles and adsorption onto the surface of particles were important for PAHs and OPAHs in both sampling periods, with more absorption occurring in September, while absorption was always the most important process for NPAHs. The total carcinogenic risk of PAHs plus the NPAHs was higher in March. Gaseous compounds, which were not considered in most previous studies, contributed 29 to 44% of the total health risk in March and September, respectively. - Highlights: • Gaseous and particulate PAHs, OPAHs, NPAHs and AZAs were measured at Xi’an. • ∑29PAHs were 1 to 2 orders of magnitude higher than ∑15OPAHs, ∑11NPAHs and ∑4AZAs. • MW can predict phase partitioning and more absorption occurred in September. • Gaseous PACs contributed 29 − 44% of total cancer risk.

  16. Uncontrolled combustion of shredded tires in a landfill - Part 1: Characterization of gaseous and particulate emissions

    Science.gov (United States)

    Downard, Jared; Singh, Ashish; Bullard, Robert; Jayarathne, Thilina; Rathnayake, Chathurika M.; Simmons, Donald L.; Wels, Brian R.; Spak, Scott N.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O.; Stone, Elizabeth A.

    2015-03-01

    In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions and to provide new insights into the qualitative nature of the smoke and the quantity of pollutants emitted. Significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAH) were observed. For the first time, PM2.5 from tire combustion was shown to contain PAH with nitrogen heteroatoms (a.k.a. azaarenes) and picene, a compound previously suggested to be unique to coal-burning. Despite prior laboratory studies' findings, metals used in manufacturing tires (i.e. Zn, Pb, Fe) were not detected in coarse particulate matter (PM10) at a distance of 4.2 km downwind. Ambient measurements were used to derive the first in situ fuel-based emission factors (EF) for the uncontrolled open burning of tires, revealing substantial emissions of SO2 (7.1 g kg-1), particle number (3.5 × 1016 kg-1), PM2.5 (5.3 g kg-1), EC (2.37 g kg-1), and 19 individual PAH (totaling 56 mg kg-1). A large degree of variability was observed in day-to-day EF, reflecting a range of flaming and smoldering conditions of the large-scale fire, for which the modified combustion efficiency ranged from 0.85 to 0.98. Recommendations for future research on this under-characterized source are also provided.