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Sample records for acenaphthene fluorene phenanthrene

  1. Acenaphthene

    Integrated Risk Information System (IRIS)

    Acenaphthene ; CASRN 83 - 32 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  2. Degradation of phenanthrene, fluorene, fluoranthene, and pyrene by a Mycobacterium sp.

    PubMed Central

    Boldrin, B; Tiehm, A; Fritzsche, C

    1993-01-01

    Mycobacterium sp. strain BB1 was isolated from a former coal gasification site. It was able to utilize phenanthrene, pyrene, and fluoranthene as sole sources of carbon and energy and to degrade fluorene cometabolically. Exponential growth with solid phenanthrene, pyrene, and fluoranthene was obtained in fermentor cultures. The growth rates were 0.069, 0.056, and 0.040 h-1, respectively. Several metabolites of phenanthrene and fluorene metabolism were identified. PMID:8328808

  3. Fluorene and Phenanthrene Uptake and Accumulation by Wheat, Alfalfa and Sunflower from the Contaminated Soil.

    PubMed

    Salehi-Lisar, Seyed Yahya; Deljoo, Somaye; Harzandi, Ahmad Mosen

    2015-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are diverse organic contaminants released into the environment by both natural and anthropogenic activities. These compounds have negative impacts on plants growth and development. Although there are many reports on their existence in different parts of plant, their uptake and translocation pathways and mechanisms are not well understood yet. This paper highlights the uptake, translocation and accumulation of PAHs by wheat, sunflower and alfalfa through an experimental study under controlled conditions. Seeds were cultivated in a soil containing 50 mg/kg of phenanthrene and fluorene and their concentrations in plants roots and shoots were determined using a gas chromatograph after 7 and 14 days. The results showed that phenanthrene and fluorene concentrations in the treated plants were increased over the time. PAHs bioavailability was time and species dependent and generally, phenanthrene uptake and translocation was faster than that of fluorene, probably due to their higher Kow. Fluorene tended to accumulate in roots, but phenanthrene was transported to aerial parts of plants. PMID:25950194

  4. Mechanistic Studies on the Dibenzofuran Formation from Phenanthrene, Fluorene and 9–Fluorenone

    PubMed Central

    Li, Shanqing; Zhang, Qingzhu

    2015-01-01

    We carried out molecular orbital theory calculations for the homogeneous gas‑phase formation of dibenzofuran from phenanthrene, fluorene, 9-methylfluorene and 9-fluorenone. Dibenzofuran will be formed if ∙OH adds to C8a, and the order of reactivity follows as 9-fluorenone > 9-methylfluorene > fluorene > phenanthrene. The oxidations initiated by ClO∙ are more favorable processes, considering that the standard reaction Gibbs energies are at least 21.63 kcal/mol lower than those of the equivalent reactions initiated by ∙OH. The adding of ∙OH and then O2 to phenanthrene is a more favorable route than adding ∙OH to C8a of phenanthrene, when considering the greater reaction extent. The reaction channel from fluorene and O2 to 9-fluorenone and H2O seems very important, not only because it contains only three elementary reactions, but because the standard reaction Gibbs energies are lower than −80.07 kcal/mol. PMID:25756381

  5. Fluorene

    Integrated Risk Information System (IRIS)

    Fluorene ; CASRN 86 - 73 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  6. Phenanthrene

    Integrated Risk Information System (IRIS)

    Phenanthrene ; CASRN 85 - 01 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  7. Actions of a versatile fluorene-degrading bacterial isolate on polycyclic aromatic compounds.

    PubMed Central

    Grifoll, M; Selifonov, S A; Gatlin, C V; Chapman, P J

    1995-01-01

    Pseudomonas cepacia F297 grew with fluorene as a sole source of carbon and energy; its growth yield corresponded to an assimilation of about 40% of fluorene carbon. The accumulation of a ring meta-cleavage product during growth and the identification of 1-indanone in growth media and washed-cell suspensions suggest that strain F297 metabolizes fluorene by mechanisms analogous to those of naphthalene degradation. In addition to fluorene, strain F297 utilized for growth a wide variety of polycyclic aromatic compounds (PACs), including naphthalene, 2,3-dimethylnaphthalene, phenanthrene, anthracene, and dibenzothiophene. Fluorene-induced cells of the strain also transformed 2,6-dimethylnaphthalene, biphenyl, dibenzofuran, acenaphthene, and acenaphthylene. The identification of products formed from those substrates (by gas chromatography-mass spectrometry) in washed-cell suspensions indicates that P. cepacia F297 carries out the following reactions: (i) aromatic ring oxidation and cleavage, apparently using the pyruvate released for growth, (ii) methyl group oxidations, (iii) methylenic oxidations, and (iv) S oxidations of aromatic sulfur heterocycles. Strain F297 grew with a creosote-PAC mixture, producing an almost complete removal of all aromatic compounds containing 2 to 3 rings in 14 days, as demonstrated by gas chromatography analysis of the remaining PACs recovered from cultures. The identification of key chemicals confirmed that not only are certain compounds depleted but also the anticipated reaction products are found. PMID:7487007

  8. Health-effects assessment for acenaphthene

    SciTech Connect

    Not Available

    1987-07-01

    Because of the lack of data for the carcinogenicity and threshold toxicity of acenaphthene risk assessment values cannot be derived. The ambient water-quality criterion of 0.2 mg/l is based on organoleptic data, which has no known relationship to potential human health effects. Acenaphthene has been shown to produce nuclear and cytological changes in microbial and plant species. Results of acenaphthene mutagenicity studies in microorganisms and carcinogenicity study are negative. Despite the negative results in the newt (Triturus cristatus) the fact that acenaphthene is a polynuclear aromatic hydrocarbon (PAH), a class of chemicals that contain carcinogens, the carcinogenic potential of acenaphthene is of great concern. Inadequate evidence to allow any conclusion regarding carcinogenicity for humans appropriately places acenaphthene in EPA Group D.

  9. Chromatographic studies of purity and segregation behaviour of natural impurities present in coal tar acenaphthene and pyrene

    NASA Astrophysics Data System (ADS)

    Marciniak, B.

    2002-05-01

    Twenty one (two unidentified) and 14 impurities were detected and identified in the bottom parts of the zone refined ingots of commercially available ex-coal tar acenaphthene and pyrene, respectively, with the help of Hewlett-Packard gas chromatographs type 6890 GC System and 5890 series II equipped with fused silica capillary columns and the FID and MS detectors. The result of quantitative determination have shown that naphthalene, 2-methylnaphthalene and 9H-fluorene, and 7-methylanthracene, 1-phenylnaphthalene, fluoranthene and unknown compound with the molecular weight of 208 may be treated as the major impurities of the above hydrocarbons, respectively. These results have also shown that with the exception of methyldibenzofuran present as impurity in acenaphthene, the segregation coefficients of all the remaining detected impurities are lower than unity. Moreover, it was found that the final distribution of the major impurities after 100 passes of the melting zone may be described with high accuracy by a third-order equation. The purification procedure worked out on the basis of the determined impurity segregation behaviour enabled the preparation of the hydrocarbons with purity ⩾99.999 mass% from which high quality crystals were grown.

  10. Colonization on Root Surface by a Phenanthrene-Degrading Endophytic Bacterium and Its Application for Reducing Plant Phenanthrene Contamination

    PubMed Central

    Liu, Juan; Liu, Shuang; Sun, Kai; Sheng, Yuehui; Gu, Yujun; Gao, Yanzheng

    2014-01-01

    A phenanthrene-degrading endophytic bacterium, Pn2, was isolated from Alopecurus aequalis Sobol grown in soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Based on morphology, physiological characteristics and the 16S rRNA gene sequence, it was identified as Massilia sp. Strain Pn2 could degrade more than 95% of the phenanthrene (150 mg·L−1) in a minimal salts medium (MSM) within 48 hours at an initial pH of 7.0 and a temperature of 30°C. Pn2 could grow well on the MSM plates with a series of other PAHs, including naphthalene, acenaphthene, anthracene and pyrene, and degrade them to different degrees. Pn2 could also colonize the root surface of ryegrass (Lolium multiflorum Lam), invade its internal root tissues and translocate into the plant shoot. When treated with the endophyte Pn2 under hydroponic growth conditions with 2 mg·L−1 of phenanthrene in the Hoagland solution, the phenanthrene concentrations in ryegrass roots and shoots were reduced by 54% and 57%, respectively, compared with the endophyte-free treatment. Strain Pn2 could be a novel and useful bacterial resource for eliminating plant PAH contamination in polluted environments by degrading the PAHs inside plants. Furthermore, we provide new perspectives on the control of the plant uptake of PAHs via endophytic bacteria. PMID:25247301

  11. The Study of Acenaphthene and its Complexation with Water

    NASA Astrophysics Data System (ADS)

    Steber, Amanda; Perez, Cristobal; Rijs, Anouk; Schnell, Melanie

    2016-06-01

    Acenaphthene (Ace) is a three ring polycyclic aromatic hydrocarbon (PAH), which consists of naphthalene and a non-aromatic five member ring. Ace has been previously been studied by microwave spectroscopy where the rotational constants were reported[1]. New measurements from 2-8 GHz using chirped pulse-Fourier transform microwave spectroscopy (CP-FTMW) will be presented. The high sensitivity achieved enabled us to observe all 13C isotopologues in natural abundance and determine the Kraitchman substitution structure. The spectra of Ace complexed with water and H218O were also recorded at this frequency range. From these spectra, we have been able to assign the complexes Ace-(H2O)n, n=1-3 and (Ace)2-H2O and experimentally derive the O-atom position of the H2O. The Ace-(H2O)3 complex is especially interesting as the water aggregate forms a slightly distorted cyclic water trimer from that observed in the IR[2]. These complexes could give insight about the formation of ice grains in the interstellar medium. [1] Thorwirth, S., Theulé, P., Gottlieb, C.A., McCarthy, M.C., Thaddeus, P. Astrophys. J., 662, 1309-1314, 2007. [2] Keutsch, F.N., Cruzan, J.D., Saykally, R.J. Chem. Rev., 103, 2533-2577, 2003.

  12. Naphthalene and acenaphthene decomposition by electron beam generated plasma application

    SciTech Connect

    Ostapczuk, A.; Hakoda, T.; Shimada, A.; Kojima, T.

    2008-08-15

    The application of non-thermal plasma generated by electron beam (EB) was investigated in laboratory scale to study decomposition of polycyclic aromatic hydrocarbons like naphthalene and acenaphthene in flue gas. PAH compounds were treated by EB with the dose up to 8 kGy in dry and humid base gas mixtures. Experimentally established G-values gained 1.66 and 3.72 mol/100 eV for NL and AC at the dose of 1 kGy. NL and AC removal was observed in dry base gas mixtures showing that the reaction with OH radical is not exclusive pathway to initialize PAH decomposition; however in the presence of water remarkably higher decomposition efficiency was observed. As by-products of NL decomposition were identified compounds containing one aromatic ring and oxygen atoms besides CO and CO{sub 2}. It led to the conclusion that PAH decomposition process in humid flue gas can be regarded as multi-step oxidative de-aromatization analogical to its atmospheric chemistry.

  13. Isolation and characterization of phenanthrene-degrading Sphingomonas paucimobilis strain ZX4.

    PubMed

    Xia, Ying; Min, Hang; Rao, Gang; Lv, Zhen-mei; Liu, Ji; Ye, Yang-fang; Duan, Xue-jun

    2005-10-01

    Phenanthrene-degrading bacterium strain ZX4 was isolated from an oil-contaminated soil, and identified as Sphingomonas paucimobilis based on 16S rDNA sequence, cellular fatty acid composition, mol% G + C and Biolog-GN tests. Besides phenanthrene, strain ZX4 could also utilize naphthalene, fluorene and other aromatic compounds. The growth on salicylic acid and catechol showed that the strain degraded phenanthrene via salicylate pathway, while the assay of catechol 2,3-dioxygenase revealed catechol could be metabolized through meta-cleavage pathway. Three genes, including two of meta-cleavage operon genes and one of GST encoding gene were obtained. The order of genes arrangement was similar to S-type metapathway operons. The phylogenetic trees based on 16S rDNA sequence and meta-pathway gene both revealed that strain ZX4 is clustered with strains from genus Sphingomonas.

  14. Transformation of substituted fluorenes and fluorene analogs by pseudomonas sp. strain F274

    SciTech Connect

    Grifoll, M.; Selifonov, S.A. |; Chapman, P.J.

    1995-09-01

    Pseudomonas sp. strain F274, previously shown to catabolize fluorene via fluorenone and its angular dioxygenation, 2`, 3`-dihydroxy-2-carboxybiphenyl, phthalate, and protocatechuate, was examined for its ability to transform substituted fluorenes and S- and N-heterocyclic analogs. Halogen- and methyl-substituted fluorenes were metabolized to correspondingly substituted phthalates via attack on the unsubstituted ring. In the case of 1-methylfluorene, initial oxidation of the methyl group to carboxyl prevented all other transformations but 9-monooxygenation. This strain also oxidized the S-heteroatoms and benzylic methylenic groups of fluorene analogs. No angular dioxygenation of S- and N-heterocycles was observed. 24 refs., 2 figs., 1 tab.

  15. 40 CFR 721.3764 - Fluorene substituted aromatic amine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fluorene substituted aromatic amine... Substances § 721.3764 Fluorene substituted aromatic amine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a fluorene substituted...

  16. 40 CFR 721.3764 - Fluorene substituted aromatic amine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fluorene substituted aromatic amine... Substances § 721.3764 Fluorene substituted aromatic amine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a fluorene substituted...

  17. Biotransformation of fluorene by the fungus Cunninghamella elegans

    SciTech Connect

    Pothuluri, J.V.; Freeman, J.P.; Evans, F.E.; Cerniglia, C.E. )

    1993-06-01

    Fluorene, a tricyclic aromatic hydrocarbon, is formed during the combustion of fossil fuels and is an important pollutant of aquatic ecosystems where it is highly toxic to fish and algae. Few studies on microbial biodegradation of fluorene have been reported. This investigation describes the metabolism of fluorene by the fungus Cunninghamella elegans ATCC 36112 and the identification of major metabolites. 26 refs., 2 figs., 1 tab.

  18. Oxidation of Acenaphthene and Acenaphthylene by Human Cytochrome P450 Enzymes

    PubMed Central

    Shimada, Tsutomu; Takenaka, Shigeo; Murayama, Norie; Yamazaki, Hiroshi; Kim, Joo-Hwan; Kim, Donghak; Yoshimoto, Francis K.; Guengerich, F. Peter; Komori, Masayuki

    2016-01-01

    Acenaphthene and acenaphthylene, two known environmental polycyclic aromatic hydrocarbon (PAH) pollutants, were incubated at 50 µM concentrations in a standard reaction mixture with human P450s 2A6, 2A13, 1B1, 1A2, 2C9, and 3A4 and the oxidation products were determined using HPLC and LC-MS. HPLC analysis showed that P450 2A6 converted acenaphthene and acenaphthylene to several mono- and di-oxygenated products. LC-MS analysis of acenaphthene oxidation by P450s indicated the formation of 1-acenaphthenol as a major product, with turnover rates of 6.7, 4.5, and 3.6 nmol product formed/min/nmol P450 for P450 2A6, 2A13, and 1B1, respectively. Acenaphthylene oxidation by P450 2A6 showed the formation of 1,2-epoxyacenaphthene as a major product (4.4 nmol epoxide formed/min/nmol P450) and also several mono- and di-oxygenated products. P450 2A13, 1B1, 1A2, 2C9, and 3A4 formed 1,2-epoxyacenaphthene at rates of 0.18, 5.3 2.4, 0.16, and 3.8 nmol/min nmol P450, respectively. 1-Acenaphthenol, which induced Type I binding spectra with P450 2A13, was further oxidized by P450 2A13 but not P450 2A6. 1,2-Epoxyacenaphthene induced Type I binding spectra with P450 2A6 and 2A13 (Ks 1.8 and 0.16 µM, respectively) and was also oxidized to several oxidation products by these P450s. Molecular docking analysis suggested different orientations of acenaphthene, acenaphthylene, 1-acenaphthenol, and 1,2-epoxyacenaphthene in their interactions with P450 2A6 and 2A13. Neither these four PAHs induced umu gene expression in a Salmonella typhimurium NM tester strain. These results suggest, for the first time, that acenaphthene and acenaphthylene are oxidized by human P450s 2A6 and 2A13 and other P450s to form several mono- and di-oxygenated products. The results are of use in considering the biological and toxicological significance of these environmental PAHs in humans. PMID:25642975

  19. Study on the volatility of halogenated fluorenes.

    PubMed

    Oliveira, Juliana A S A; Oliveira, Tânia S M; Gaspar, Alexandra; Borges, Fernanda; Ribeiro da Silva, Maria D M C; Monte, Manuel J S

    2016-08-01

    This work reports the experimental determination of relevant thermophysical properties of five halogenated fluorenes. The vapor pressures of the compounds studied were measured at different temperatures using two different experimental techniques. The static method was used for studying 2-fluorofluorene (liquid and crystal vapor pressures between 321.04 K and 411.88 K), 2-iodofluorene (liquid and crystal vapor pressures between 362.63 K and 413.86 K), and 2,7-dichlorofluorene (crystal vapor pressures between 364.64 K and 394.22 K). The Knudsen effusion method was employed to determine the vapor pressures of 2,7-difluorofluorene (crystal vapor pressures between 299.17 K and 321.19 K), 2,7-diiodofluorene (crystal vapor pressures between 393.19 K and 415.14 K), and (again) 2-iodofluorene (crystal vapor pressures between 341.16 K and 361.12 K). The temperatures and the molar enthalpies of fusion of the five compounds were determined using differential scanning calorimetry. The application to halogenated fluorenes of recently developed methods for predicting vapor pressures and enthalpies of sublimation and vaporization of substituted benzenes is also discussed. PMID:27206270

  20. Electrochemical remediation of phenanthrene from contaminated kaolinite.

    PubMed

    Alcántara, T; Pazos, M; Cameselle, C; Sanromán, M A

    2008-04-01

    In this work a two-stage process combining soil electrokinetic remediation and liquid electrochemical oxidation for the remediation of polluted soil with organic compounds has been developed and evaluated using phenanthrene-spiked kaolinite. Application of an unenhanced electrokinetic process resulted in negligible removal of phenanthrene from the kaolinite sample. Addition of co-solvents and electrolyte to the processing fluid used in the electrode chambers enhanced phenanthrene desorption from the kaolinite matrix and favoured electro-osmotic flow. Near-complete removal of phenanthrene was achieved using Na2SO4 and ethanol in the processing fluid. Phenanthrene was transported towards the cathode chamber where it was collected. The cathodic solution containing the pollutant was treated by electrochemical oxidation; complete degradation of phenanthrene occurred after 9 h using Na2SO4 as electrolyte.

  1. Predicting survival of grass shrimp (Palaemonetes pugio) exposed to naphthalene, fluorene, and dibenzothiophene.

    PubMed

    Unger, Michael A; Newman, Michael C; Vadas, George G

    2008-08-01

    The composition and persistence of dissolved polycyclic aromatic hydrocarbons (PAHs) released to the water column during oil spills are altered by weathering, tidal transport, and addition of dispersants. Conventional toxicity effect metrics, such as the median lethal concentration (LC50), are inaccurate predictors of mortality from all toxicant exposure duration/concentration combinations likely to occur during spills. In contrast, survival models can predict the proportions of animals dying as a consequence of exposures differing in duration and intensity. Extending previous work with ethylnaphthalene, dimethylnaphthalene, and phenanthrene, survival time models were developed that include exposure duration and concentration to predict time to death for grass shrimp (Palaemonetes pugio). Two additional PAHs (naphthalene and fluorene) and a heterocyclic aromatic hydrocarbon (dibenzothiophene) were evaluated for the present study. Preliminary explorations of these models confirmed that quantitative structure- activity regression models were possible for predicting survival model parameters from compound characteristics. Conventional 48-h LC50s also were calculated for the compounds and combined with published LC50s to predict relative PAH toxicity to P. pugio based on octanol-water partitioning. PMID:18380521

  2. 40 CFR 721.10247 - Bis-phenoxyethanol fluorene diacrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Bis-phenoxyethanol fluorene diacrylate... Specific Chemical Substances § 721.10247 Bis-phenoxyethanol fluorene diacrylate (generic). (a) Chemical... as bis-phenoxyethanol fluorene diacrylate (PMN P-09-258) is subject to reporting under this...

  3. 40 CFR 721.10247 - Bis-phenoxyethanol fluorene diacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Bis-phenoxyethanol fluorene diacrylate... Specific Chemical Substances § 721.10247 Bis-phenoxyethanol fluorene diacrylate (generic). (a) Chemical... as bis-phenoxyethanol fluorene diacrylate (PMN P-09-258) is subject to reporting under this...

  4. 40 CFR 721.10247 - Bis-phenoxyethanol fluorene diacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Bis-phenoxyethanol fluorene diacrylate... Specific Chemical Substances § 721.10247 Bis-phenoxyethanol fluorene diacrylate (generic). (a) Chemical... as bis-phenoxyethanol fluorene diacrylate (PMN P-09-258) is subject to reporting under this...

  5. Synthesis and investigation of carbazoles and fluorenes containing tetrathiafulvalene core

    NASA Astrophysics Data System (ADS)

    Abashev, George G.; Shklyaeva, Elena V.; Syutkin, Roman V.; Lebedev, Konstantin Yu.; Osorgina, Irina V.; Romanova, Valentina A.; Bushueva, Anastasya Yu.

    2008-12-01

    For the first time carbazole- and fluorene-based monomers containing tetrathiafulvalene moieties were prepared. All the synthesized monomers were electrochemically polymerized in CH 3CN (CH 2Cl 2) media using (C 2H 5)N 4ClO 4 (1:1) as the supporting electrolyte. The properties of the resulting polymers were characterized by cyclic voltammetry (CV).

  6. 40 CFR 721.3764 - Fluorene substituted aromatic amine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fluorene substituted aromatic amine. 721.3764 Section 721.3764 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3764...

  7. Optically enhanced nuclear cross polarization in acridine-doped fluorene

    SciTech Connect

    Oshiro, C.M.

    1982-06-01

    The objective of this work has been to create large polarizations of the dilute /sup 13/C nuclei in the solid state. The idea was to create /sup 1/H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the /sup 13/C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large /sup 1/H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large /sup 13/C polarizations have been created in fluorene single crystals. These large /sup 13/C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined.

  8. Two-electron carbon dioxide reduction catalyzed by rhenium(I) bis(imino)acenaphthene carbonyl complexes.

    PubMed

    Portenkirchner, Engelbert; Kianfar, Elham; Sariciftci, Niyazi Serdar; Knör, Günther

    2014-05-01

    Rhenium(I) carbonyl complexes carrying substituted bis(arylimino)acenaphthene ligands (BIAN-R) have been tested as potential catalysts for the two-electron reduction of carbon dioxide. Cyclic voltammetric studies as well as controlled potential electrolysis experiments were performed using CO2-saturated solutions of the complexes in acetonitrile and acetonitrile-water mixtures. Faradaic efficiencies of more than 30 % have been determined for the electrocatalytic production of CO. The effects of ligand substitution patterns and water content of the reaction medium on the catalytic performance of the new catalysts are discussed.

  9. Homogeneous and heterogeneous reactions of phenanthrene with ozone

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Yang, Bo; Meng, Junwang; Gao, Shaokai; Dong, Xinyu; Shu, Jinian

    2010-02-01

    The reactions of gas-phase phenanthrene and suspended phenanthrene particles with ozone were conducted in a 200l chamber. The secondary organic aerosol formation was observed in the reaction of gas-phase phenanthrene with ozone and simultaneously the size distribution of the secondary organic aerosol was monitored with a scanning mobility particle sizer during the formation process. The particulate ozonation products from both reactions were analyzed with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer. 2,2'-Diformylbiphenyl was identified as the dominant product in both homogeneous and heterogeneous reactions of phenanthrene with ozone. GC/MS analysis of ozonation products of phenanthrene in glacial acetic acid was carried out for assigning time-of-flight mass spectra of reaction products formed in the homogeneous and heterogeneous reactions of phenanthrene with ozone.

  10. H- and J-aggregation of fluorene-based chromophores.

    PubMed

    Deng, Yonghong; Yuan, Wen; Jia, Zhe; Liu, Gao

    2014-12-11

    Understanding of H- and J-aggregation behaviors in fluorene-based polymers is significant both for determining the origin of various red-shifted emissions occurring in blue-emitting polyfluorenes and for developing polyfluorene-based device performance. In this contribution, we demonstrate a new theory of the H- and J-aggregation of polyfluorenes and oligofluorenes, and understand the influence of chromosphere aggregation on their photoluminescent properties. H- and J-aggregates are induced by a continuous increasing concentration of the oligofluorene or polyfluorene solution. A relaxed molecular configuration is simulated to illustrate the spatial arrangement of the bonding of fluorenes. It is indicated that the relaxed state adopts a 21 helical backbone conformation with a torsion angle of 18° between two connected repeat units. This configuration makes the formation of H- and J-aggregates through the strong π-π interaction between the backbone rings. A critical aggregation concentration is observed to form H- and J-aggregates for both polyfluorenes and oligofluorenes. These aggregates show large spectral shifts and distinct shape changes in photoluminescent excitation (PLE) and emission (PL) spectroscopy. Compared with "isolated" chromophores, H-aggregates induce absorption spectral blue-shift and fluorescence spectral red-shift but largely reduce fluorescence efficiency. "Isolated" chromophores not only refer to "isolated molecules" but also include those associated molecules if their conjugated backbones are not compact enough to exhibit perturbed absorption and emission. J-aggregates induce absorption spectral red-shift and fluorescence spectral red-shift but largely enhance fluorescence efficiency. The PLE and PL spectra also show that J-aggregates dominate in concentrated solutions. Different from the excimers, the H- and J-aggregate formation changes the ground-state absorption of fluorene-based chromophores. H- and J-aggregates show changeable

  11. H- and J-aggregation of fluorene-based chromophores.

    PubMed

    Deng, Yonghong; Yuan, Wen; Jia, Zhe; Liu, Gao

    2014-12-11

    Understanding of H- and J-aggregation behaviors in fluorene-based polymers is significant both for determining the origin of various red-shifted emissions occurring in blue-emitting polyfluorenes and for developing polyfluorene-based device performance. In this contribution, we demonstrate a new theory of the H- and J-aggregation of polyfluorenes and oligofluorenes, and understand the influence of chromosphere aggregation on their photoluminescent properties. H- and J-aggregates are induced by a continuous increasing concentration of the oligofluorene or polyfluorene solution. A relaxed molecular configuration is simulated to illustrate the spatial arrangement of the bonding of fluorenes. It is indicated that the relaxed state adopts a 21 helical backbone conformation with a torsion angle of 18° between two connected repeat units. This configuration makes the formation of H- and J-aggregates through the strong π-π interaction between the backbone rings. A critical aggregation concentration is observed to form H- and J-aggregates for both polyfluorenes and oligofluorenes. These aggregates show large spectral shifts and distinct shape changes in photoluminescent excitation (PLE) and emission (PL) spectroscopy. Compared with "isolated" chromophores, H-aggregates induce absorption spectral blue-shift and fluorescence spectral red-shift but largely reduce fluorescence efficiency. "Isolated" chromophores not only refer to "isolated molecules" but also include those associated molecules if their conjugated backbones are not compact enough to exhibit perturbed absorption and emission. J-aggregates induce absorption spectral red-shift and fluorescence spectral red-shift but largely enhance fluorescence efficiency. The PLE and PL spectra also show that J-aggregates dominate in concentrated solutions. Different from the excimers, the H- and J-aggregate formation changes the ground-state absorption of fluorene-based chromophores. H- and J-aggregates show changeable

  12. Light-Emitting Properties of Fluorene-Based Copolymers

    NASA Astrophysics Data System (ADS)

    Hwang, Do-Hoon; Lee, Jong-Don; Park, Moo-Jin; Lee, Ji-Hoon; Lee, Chang-Hee

    A series of random copolymers of 2,7-dibromo-9,9-bis(4‧-n-octyloxyphenyl) fluorene (BOPF) and 2,7-dibromo-N-(2‧-ethylhexyl)carbazole (EHC) were synthesized through Ni(0)-mediated polymerization. Carbazole comonomer was introduced to improve the hole-transporting properties of PBOPF. The synthesized poly(BOPF-co-EHC)s showed similar UV-visible absorption and PL emission to PBOPF. EL devices were fabricated in an ITO/PEDOT/polymer/Ca/Al configuration. EL devices which used copolymers showed improved device performance over devices which used PBOPF homopolymers due to a more balanced charge transport.

  13. The coordination chemistry of two symmetric fluorene-based organic ligands with cuprous chloride.

    PubMed

    Liu, Yan-Fei; Zhao, Chao-Wei; Ma, Jian-Ping; Liu, Qi-Kui; Dong, Yu-Bin

    2013-12-15

    Two novel symmetric fluorene-based ligands, namely, 2,7-bis(1H-imidazol-1-yl)-9,9-dimethyl-9H-fluorene [L1 or (I), C21H18N4] and 2,7-bis(1H-imidazol-1-yl)-9,9-dipropyl-9H-fluorene (L2), have been used to construct the coordination polymers catena-poly[[dichloridodicopper(I)(Cu-Cu)]-μ-2,7-bis(1H-imidazol-1-yl)-9,9-dimethyl-9H-fluorene], [Cu2Cl2(C21H18N4)]n, (II), and catena-poly[[tetra-μ2-chlorido-tetracopper(I)]-bis[μ-2,7-bis(1H-imidazol-1-yl)-9,9-dipropyl-9H-fluorene

  14. Evidence for a novel pathway in the degradation of fluorene by Pseudomonas sp. strain F274.

    PubMed Central

    Grifoll, M; Selifonov, S A; Chapman, P J

    1994-01-01

    A fluorene-utilizing microorganism, identified as a species of Pseudomonas, was isolated from soil severely contaminated from creosote use and was shown to accumulate six major metabolites from fluorene in washed-cell incubations. Five of these products were identified as 9-fluorenol, 9-fluorenone, (+)-1,1a-dihydroxy-1-hydro-9-fluorenone, 8-hydroxy-3,4-benzocoumarin, and phthalic acid. This last compound was also identified in growing cultures supported by fluorene. Fluorene assimilation into cell biomass was estimated to be approximately 50%. The structures of accumulated products indicate that a previously undescribed pathway of fluorene catabolism is employed by Pseudomonas sp. strain F274. This pathway involves oxygenation of fluorene at C-9 to give 9-fluorenol, which is then dehydrogenated to the corresponding ketone, 9-fluorenone. Dioxygenase attack on 9-fluorenone adjacent to the carbonyl group gives an angular diol, 1,1a-dihydroxy-1-hydro-9-fluorenone. Identification of 8-hydroxy-3,4-benzocoumarin and phthalic acid suggests that the five-membered ring of the angular diol is opened first and that the resulting 2'-carboxy derivative of 2,3-dihydroxy-biphenyl is catabolized by reactions analogous to those of biphenyl degradation, leading to the formation of phthalic acid. Cell extracts of fluorene-grown cells possessed high levels of an enzyme characteristic of phthalate catabolism, 4,5-dihydroxyphthalate decarboxylase, together with protocatechuate 4,5-dioxygenase. On the basis of these findings, a pathway of fluorene degradation is proposed to account for its conversion to intermediary metabolites. A range of compounds with structures similar to that of fluorene was acted on by fluorene-grown cells to give products consistent with the initial reactions proposed. PMID:8074523

  15. Tuning the Electronic Properties of Acetylenic Fluorenes by Phosphaalkene Incorporation.

    PubMed

    Svyaschenko, Yurii V; Orthaber, Andreas; Ott, Sascha

    2016-03-14

    Versatile synthetic protocols for 2,7- and 3,6-diacetylenic fluorene-9-ylidene phosphanes (F9Ps) were developed. Protodesilylation of trimethylsilyl-protected acetylenic F9Ps affords terminal acetylenes that can be employed in Sonogashira and Glaser-type C-C coupling reactions to give thienyl-decorated and butadiyne-bridged fluorene-9-ylidene phosphanes, respectively. As evidenced by UV/Vis spectroscopy and cyclic voltammetry and corroborated by ab initio calculations, the presence of the P center in the F9Ps induces a significantly reduced HOMO-LUMO splitting that originates from stabilization of the LUMO levels. Variation of the acetylene substitution pattern is an additional tool to influence the optical and electronic properties. Whereas 3,6-disubstituted F9Ps have strong absorptions around 400 nm, mainly due to π-π* transitions, 2,7-diacetylenic F9Ps exhibit longest-wavelength absorptions that have significant charge-transfer character with an onset around 520 nm. PMID:26833389

  16. Spirobifluorene and biphenylaminophenyl fluorene with dimesitylboron as multifunctional electroluminescent materials

    NASA Astrophysics Data System (ADS)

    Zhang, Wenguan; He, Zhiqun; Pang, Hui; Wang, Yongsheng; Zhao, Shengmin

    2015-12-01

    By introducing triarylamino and dimesitylboron groups into fluorene derivatives, two symmetric compounds 2,7-bis(dimesitylboryl)-9,9-spirobifluorene (SFMB) and 2,7-bis(dimesitylboryl)-9,9-bis(4-diphenylaminophenyl)fluorene (PAFMB) were prepared. SFMB and PAFMB exhibited solvatochromism in the different polarities of solvents. Devices A1, A2, A3 and A4 based on SFMB displayed emissions at 444, 448, 528, and 444 nm with current efficiencies of 1.06, 1.41, 0.84, and 1.52 cd/A, respectively. The blue light was close to the National Television Standards Committee standard blue color (x = 0.14, y = 0.08). Devices B1, B2, B3 and B4 based on PAFMB emitted lights centered at 484, 472, 513 and 472 nm, their current efficiencies were 1.80, 0.1, 1.23 and 1.93 cd/A, respectively. The results demonstrated that SFMB and PAFMB were multifunctional materials acted as emitters, and hole- and electron-transporting materials.

  17. An Undergraduate Laboratory Project Involving Photocyclizations in Independent Syntheses of Novel Chrysenes and Phenanthrenes.

    ERIC Educational Resources Information Center

    Letcher, R. M.

    1981-01-01

    Describes a project and experimental procedures, suitable for a final year organic chemistry course, in which students synthesize a variety of substituted phenanthrenes, chrysenes, and benzo phenanthrenes. (SK)

  18. Biodegradation of phenanthrene by fungi screened from nature.

    PubMed

    Hadibarata, Tony; Tachibana, Sanro; Itoh, Kazutaka

    2007-08-01

    Microbial degradation of Phenanthrene with several fungi screened from nature was conducted to select fungi for the bioremediation ofPhenanthrene. Thrichoderma sp. S019, a fungus collected from soil, had the highest rate of degradation on the agar medium containing Phenanthrene. Maximal degradation (72%) was obtained when Trichoderma sp. S019 was incubated for 30 days after the addition of 0.1 mM of Phenanthrene to the liquid medium. Furthermore, the degradation of Phenanthrene was affected by the addition of a carbon source, the addition of a nitrogen source and agitation. Also, 1,2-Dioxygenase and 2,3-Dioxygenase were produced by Trichoderma sp. S019 in a liquid medium. These enzymes play an important role in the metabolism of substrates, revealing a high stereoselectivity for initial dioxygenase and enzymatic hydration since the K-region of phenanthrene was the major site of metabolism. Phenanthrene was indeed degraded by Trichoderma sp. S019 because 1-Hydroxy-2-naphthoic acid, Salicyaldehyde, Salicylic acid and Catechol, considered to be the intermediates in the bioremediation of Phenanthrene, were detected among the reaction products.

  19. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures

    PubMed Central

    Rice, James W.; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C.; Suuberg, Eric M.

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior (i.e., fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly lnP/Pa = −2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene (xP) in the mixture is less than or equal to 0.80. Mixtures initially at xP = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 < xP < 5) indicating that anthracene may accommodate very low levels of phenanthrene in its crystal structure. PMID:26973354

  20. Evaluating phenanthrene sorption on various wood chars

    USGS Publications Warehouse

    James, G.; Sabatini, D.A.; Chiou, C.T.; Rutherford, D.; Scott, A.C.; Karapanagioti, H.K.

    2005-01-01

    A certain amount of wood char or soot in a soil or sediment sample may cause the sorption of organic compounds to deviate significantly from the linear partitioning commonly observed with soil organic matter (SOM). Laboratory produced and field wood chars have been obtained and analyzed for their sorption isotherms of a model solute (phenanthrene) from water solution. The uptake capacities and nonlinear sorption effects with the laboratory wood chars are similar to those with the field wood chars. For phenanthrene aqueous concentrations of 1 ??gl-1, the organic carbon-normalized sorption coefficients (log Koc) ranging from 5.0 to 6.4 for field chars and 5.4-7.3 for laboratory wood chars, which is consistent with literature values (5.6-7.1). Data with artificial chars suggest that the variation in sorption potential can be attributed to heating temperature and starting material, and both the quantity and heterogeneity of surface-area impacts the sorption capacity. These results thus help to corroborate and explain the range of log Koc values reported in previous research for aquifer materials containing wood chars. ?? 2004 Elsevier Ltd. All rights reserved.

  1. Synthesis of polyamides from diamines of the fluorene series

    NASA Technical Reports Server (NTRS)

    Fedotova, O. Y.; Korshak, V. V.; Nesterova, Y. I.

    1984-01-01

    Aromatic polyamides were prepared by polycondensation of isophthaloyl chloride and 2,7-diaminofluorene, 2,7-dimainofluorenone, or 2,5-diaminofluorenone in AcNMe2 or N-methyl-2-pyrrolidinone at 20 deg - 30 deg for 1.5-2 hr. Isophthaloyl chloride-2,5-diaminofluorenone copolymer 39609-29-51 was sol. in AcNMe2, N-methyl-2-pyrrolidinone, DMF, and hexamethylphosphoramide, whereas isophthaloyl chloride-2,7-diamino-fluorene copolymer 39609-30-3 and isophthaloyl chloride-2,7-diamino-fluorenone copolymer 39609-31-0 were not sol. in the solvents cited. The aromatic polyamides revealed thixotropic properties in 0.5% solutions in H2SO4.

  2. Fluorene-Perylene Diimide Arrays onto Graphene Sheets for Photocatalysis.

    PubMed

    Stergiou, Anastasios; Tagmatarchis, Nikos

    2016-08-24

    A facile approach for introducing photoactive poly(fluorene-perylene diimide) arrays (PFPDI) onto graphene sheets was accomplished. Noncovalent PFPDI/graphene ensembles formed via π-π stacking interactions between the two components and covalent PFPDI-graphene hybrids realized upon a Stille polycondensation reaction between an iodobenzyl-functionalized graphene, a 9,9-dialkyl substituted fluorene diboronic acid, and a 1,7-dibromo-PDI derivative were prepared. The morphology of PFPDI/graphene and PFPDI-graphene was evaluated by high-resolution transmission electron microscopy (HR-TEM), revealing the presence of even monolayered graphene sheets. Moreover, their photophysical and redox properties as assessed by electronic absorption spectroscopy and steady-state as well as time-resolved photoluminescence assays and electrochemistry, respectively, disclosed charge-transfer characteristics owing to the high photoluminescence quenching of PFPDI in the presence of graphene and the fast component attributed to the decay of the emission intensity of the singlet excited state of PFPDI in both PFPDI/graphene and PFPDI-graphene. Next, testing their ability to operate in energy conversion schemes, the PFPDI-graphene was successfully employed as catalyst for the reduction of 4-nitrophenol to 4-aminophenol. Notably, the kinetics for the reduction were enhanced by visible light photoirradiation as compared to dark conditions as well as the presence of PFPDI-graphene, contrasting the case where only PFPDI, in the absence of graphene, was employed. Finally, recycling of the catalyst PFPDI-graphene was achieved and reutilization in successive reduction reactions of 4-nitrophenol was found to proceed with the same efficiency.

  3. Fluorene-Perylene Diimide Arrays onto Graphene Sheets for Photocatalysis.

    PubMed

    Stergiou, Anastasios; Tagmatarchis, Nikos

    2016-08-24

    A facile approach for introducing photoactive poly(fluorene-perylene diimide) arrays (PFPDI) onto graphene sheets was accomplished. Noncovalent PFPDI/graphene ensembles formed via π-π stacking interactions between the two components and covalent PFPDI-graphene hybrids realized upon a Stille polycondensation reaction between an iodobenzyl-functionalized graphene, a 9,9-dialkyl substituted fluorene diboronic acid, and a 1,7-dibromo-PDI derivative were prepared. The morphology of PFPDI/graphene and PFPDI-graphene was evaluated by high-resolution transmission electron microscopy (HR-TEM), revealing the presence of even monolayered graphene sheets. Moreover, their photophysical and redox properties as assessed by electronic absorption spectroscopy and steady-state as well as time-resolved photoluminescence assays and electrochemistry, respectively, disclosed charge-transfer characteristics owing to the high photoluminescence quenching of PFPDI in the presence of graphene and the fast component attributed to the decay of the emission intensity of the singlet excited state of PFPDI in both PFPDI/graphene and PFPDI-graphene. Next, testing their ability to operate in energy conversion schemes, the PFPDI-graphene was successfully employed as catalyst for the reduction of 4-nitrophenol to 4-aminophenol. Notably, the kinetics for the reduction were enhanced by visible light photoirradiation as compared to dark conditions as well as the presence of PFPDI-graphene, contrasting the case where only PFPDI, in the absence of graphene, was employed. Finally, recycling of the catalyst PFPDI-graphene was achieved and reutilization in successive reduction reactions of 4-nitrophenol was found to proceed with the same efficiency. PMID:27483330

  4. Factors affecting sequestration and bioavailability of phenanthrene in soils

    SciTech Connect

    White, J.C.; Kelsey, J.W.; Hatzinger, P.B.; Alexander, M.

    1997-10-01

    A study was conducted to determine factors affecting the sequestration and changes in bioavailability as phenanthrene persists in soils. Phenanthrene became sequestered in seven soils differing appreciably in organic matter and clay content as measured by earthworm uptake, bacterial mineralization, or extractability. Phenanthrene also became sequestered as it aged in soil aggregates of various sizes as measured by decline in availability to a bacterium, a mild extractant, or both. Wetting and drying a soil during aging reduced the amount of phenanthrene recovered by a mild extractant and the rate and extent of bacterial mineralization of the hydrocarbon. After biodegradation of phenanthrene added to the soil, more of the compound remained if it had been aged than if it had not been aged. Wetting and drying the soil during aging further increased the amount of phenanthrene remaining after biodegradation. The rate and extent of bacterial mineralization of phenanthrene were less in leached than in unleached soil. Aging/sequestration is thus markedly affected by soil properties and environmental factors.

  5. 40 CFR 464.31 - Specialized definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-benzanthracene) 76. chrysene 77. acenaphthylene 78. anthracene 80. fluorene 81. phenanthrene 84. pyrene (3...-benzanthracene) 76. chrysene 77. acenaphthylene 78. anthracene 80. fluorene 81. phenanthrene 84. pyrene (5)...

  6. 40 CFR 464.31 - Specialized definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-benzanthracene) 76. chrysene 77. acenaphthylene 78. anthracene 80. fluorene 81. phenanthrene 84. pyrene (3...-benzanthracene) 76. chrysene 77. acenaphthylene 78. anthracene 80. fluorene 81. phenanthrene 84. pyrene (5)...

  7. Toxic photoproducts of phenanthrene and anthracene in sunlight

    SciTech Connect

    Duxbury, C.L.; McConkey, B.J.; Mallakin, A.; Dixon, D.G.; Greenberg, B.M.

    1995-12-31

    Phenanthrene and anthracene, two of the most prevalent PAHs, undergo significant increases in toxicity on exposure to sunlight. Over a period of several days exposure to light, the toxicity of an aqueous solution of phenanthrene or anthracene increased dramatically. This increase in toxicity is largely due to the primary products formed by these two PAHs due to light exposure. These compounds are more toxic than the parent compounds at equimolar concentrations. Although anthracene is a potent photosensitizer, phenanthrene did not exhibit a significant increase in toxicity due to photosensitization. Photo-oxidation was the principal cause of photoinduced toxicity, with 9,10-phenanthrenequinone being the primary product. This compound is more water soluble than phenanthrene increasing its bioavailability. In addition, mixtures of phenanthrene and 9,10-phenanthrenequinone exhibited toxicity similar to the quinone added alone. This was shown by joint toxicity testing using Lemna gibba and Daphnia magna. These two organisms are currently being used in the lab to further test individual oxidized products of anthracene and phenanthrene that occur as a result of exposure to sunlight.

  8. Triplet exciton transport in the benzophenone-fluorene-naphthalene molecule

    NASA Astrophysics Data System (ADS)

    McElfresh, Duncan C.

    Incoherent triplet-triplet energy transfer through the benzophenone-fluorene-naphthalene system is computationally investigated to determine triplet hopping rates. These rates have been previously measured experimentally and have also been estimated computationally. There are many complex steps associated with such a computational analysis, though, and earlier efforts resorted to a variety of semi-empirical modifications to the methods used in order to obtain results consistent with the experimental data. This has motivated an investigation in which best practice methods are applied to the system without any empirical adjustments. The calculation of triplet excitation energy and triplet-triplet electronic coupling are examined in detail using a range of computational methods from simple Density Functional Theory to the many-body Green function approach embodied in the Bethe-Salpeter Equation. This analysis includes an evaluation of the robustness of each method considered. Significantly, the investigation identifies the excited states of benzophenone as being extremely difficult to calculate using even the most advanced excitation methods, and a theory is presented as to why the molecule is both interesting and troublesome. The final rate estimates, without any empirical adjustments, are one to two orders of magnitude greater than those measured experimentally. This data, and the detailed methodological study supporting it, is expected to be helpful in future efforts to computationally scrutinize triplet exciton hopping.

  9. Use of bromodeoxyuridine immunocapture to identify psychrotolerant phenanthrene-degrading bacteria in phenanthrene-enriched polluted Baltic Sea sediments

    SciTech Connect

    Edlund, A.; Jansson, J.

    2008-05-01

    The aim of this study was to enrich and identify psychrotolerant phenanthrenedegrading bacteria from polluted Baltic Sea sediments. Polyaromatic hydrocarbon (PAH)-contaminated sediments were spiked with phenanthrene and incubated for 2 months in the presence of bromodeoxyuridine that is incorporated into the DNA of replicating cells. The bromodeoxyuridine-incorporated DNA was extracted by immunocapture and analyzed by terminal-restriction fragment length polymorphism and 16S rRNA gene cloning and sequencing to identify bacterial populations that were growing. In addition, degradation genes were quantified in the bromodeoxyuridine-incorporated DNA by real-time PCR. Phenanthrene concentrations decreased after 2 months of incubation in the phenanthrene-enriched sediments and this reduction correlated to increases in copy numbers of xylE and phnAc dioxygenase genes. Representatives of Exiguobacterium, Schewanella,Methylomonas, Pseudomonas, Bacteroides and an uncultured Deltaproteobacterium and a Gammaproteobacterium dominated the growing community in the phenanthrene spiked sediments. Isolates that were closely related to three of these bacteria (two pseudomonads and an Exiguobacterium sp.) could reduce phenanthrene concentrations in pure cultures and they all harbored phnAc dioxygenase genes. These results confirm that this combination of culture-based and molecular approaches was useful for identification of actively growing bacterial species with a high potential for phenanthrene degradation.

  10. Metabolism of phenanthrene by brown bullhead liver microsomes.

    PubMed

    Pangrekar, Jyotsna; Kole, Panna L; Honey, Sangeet A; Kumar, Subodh; Sikka, Harish C

    2003-09-10

    We have investigated the regio- and stereoselective metabolism of phenanthrene by the liver microsomes of brown bullhead (Ameriurus nebulosus), a bottom dwelling fish species. The liver microsomes from untreated and 3-methylcholanthrene (3-MC)-treated brown bullheads metabolized phenanthrene at a rate of 14.1 and 20.7 pmol/mg protein/min, respectively, indicating that the hydrocarbon is a rather poor substrate for bullhead liver microsomes contrary to what has been reported for rat liver microsomes. The major phenanthrene metabolites formed by liver microsomes from untreated and 3-MC-treated bullheads included benzo-ring 1,2-dihydrodiol (25.3 and 11.6%), K-region 9,10-dihydrodiol (9.6 and 9.6%), and phenols (40.5 and 54.5%). The 3,4-dihydrodiol represented a minor proportion of the total phenanthrene metabolites. The low proportion of the 9,10-dihydrodiol formed by both control and 3-MC-treated bullhead microsomes sharply contrasts the previous data reported for the corresponding rat liver microsomes which metabolized phenanthrene predominantly to its 9,10-dihydrodiol representing 76.6 and 67.1%, respectively of the total metabolites. Liver microsomes from 3-MC-treated bullheads, like rat liver microsomes, were more selective in their attack at the 1,2-position of the benzo-ring than at the 3,4-position of the benzo-ring. Phenanthrene 1,2-dihydrodiol and 3,4-dihydrodiol formed by liver microsomes from both control and 3-MC-treated bullheads consisted predominantly of their R,R enantiomer. Phenanthrene, compared with benzo[a]pyrene and chrysene, is metabolized by bullhead liver microsomal enzymes to its benzo-ring dihydrodiols with a relatively low degree of stereoselectivity.

  11. Photodegradation of fluorene in aqueous solution: Identification and biological activity testing of degradation products.

    PubMed

    Kinani, Said; Souissi, Yasmine; Kinani, Aziz; Vujović, Svetlana; Aït-Aïssa, Sélim; Bouchonnet, Stéphane

    2016-04-15

    Degradation of fluorene under UV-vis irradiation in water was investigated and structural elucidation of the main photoproducts was achieved using gas chromatography coupled with mass spectrometry. Twenty-six photoproducts were structurally identified, mainly on the basis of electron ionization mass spectra interpretation. The main generated transformation products are hydroxy derivatives. Some secondary photoproducts including fluorenone, hydroxy fluorenone, 2-biphenyl carboxylic acid, biphenylene, methanol fluorene congeners and hydroxy fluorene dimers were also observed. A photodegradation pathway was suggested on the basis of the chemical structures of photoproducts. Fluorene as well as its main photoproducts for which chemical standards were commercially available were tested for their ability to elicit cytotoxic, estrogenic and dioxin-like activity by using in vitro cell-based bioassays. None of the tested compounds was cytotoxic at concentrations up to 100 μM. However, 2-hydroxyfluorene and 3-hydroxyfluorene exerted significant estrogenic and dioxin-like activity on a concentration range of 3-30 μM, while fluorene and 9-hydroxyfluorene were weakly or not active, respectively, in our assays. This supports the view that photodegradation processes can generate by-products of higher toxicological concern than the parent compound and strengthens the need to further identify transformation products in the aquatic environment.

  12. Electronic Structure and Multicatalytic Features of Redox-Active Bis(arylimino)acenaphthene (BIAN)-Derived Ruthenium Complexes.

    PubMed

    Singha Hazari, Arijit; Ray, Ritwika; Hoque, Md Asmaul; Lahiri, Goutam Kumar

    2016-08-15

    The article examines the newly designed and structurally characterized redox-active BIAN-derived [Ru(trpy)(R-BIAN)Cl]ClO4 ([1a]ClO4-[1c]ClO4), [Ru(trpy)(R-BIAN)(H2O)](ClO4)2 ([3a](ClO4)2-[3c](ClO4)2), and BIAO-derived [Ru(trpy)(BIAO)Cl]ClO4 ([2a]ClO4) (trpy = 2,2':6',2''-terpyridine, R-BIAN = bis(arylimino)acenaphthene (R = H (1a(+), 3a(2+)), 4-OMe (1b(+), 3b(2+)), 4-NO2 (1c(+), 3c(2+)), BIAO = [N-(phenyl)imino]acenapthenone). The experimental (X-ray, (1)H NMR, spectroelectrochemistry, EPR) and DFT/TD-DFT calculations of 1a(n)-1c(n) or 2a(n) collectively establish {Ru(II)-BIAN(0)} or {Ru(II)-BIAO(0)} configuration in the native state, metal-based oxidation to {Ru(III)-BIAN(0)} or {Ru(III)-BIAO(0)}, and successive electron uptake processes by the α-diimine fragment, followed by trpy and naphthalene π-system of BIAN or BIAO, respectively. The impact of the electron-withdrawing NO2 function in the BIAN moiety in 1c(+) has been reflected in the five nearby reduction steps within the accessible potential limit of -2 V versus SCE, leading to a fully reduced BIAN(4-) state in [1c](4-). The aqua derivatives ({Ru(II)-OH2}, 3a(2+)-3c(2+)) undergo simultaneous 2e(-)/2H(+) transfer to the corresponding {Ru(IV)═O} state and the catalytic current associated with the Ru(IV)/Ru(V) response probably implies its involvement in the electrocatalytic water oxidation. The aqua derivatives (3a(2+)-3c(2+)) are efficient and selective precatalysts in transforming a wide variety of alkenes to corresponding epoxides in the presence of PhI(OAc)2 as an oxidant in CH2Cl2 at 298 K as well as oxidation of primary, secondary, and heterocyclic alcohols with a large substrate scope with H2O2 as the stoichiometric oxidant in CH3CN at 343 K. The involvement of the {Ru(IV)═O} intermediate as the active catalyst in both the oxidation processes has been ascertained via a sequence of experimental evidence. PMID:27482834

  13. Plant-enhanced phenanthrene and pyrene biodegradation in acidic soil.

    PubMed

    Chouychai, Waraporn; Thongkukiatkul, Amporn; Upatham, Suchart; Lee, Hung; Pokethitiyook, Prayad; Kruatrachue, Maleeya

    2009-01-01

    A study was undertaken to assess if corn plant (Zea may L.) maybe able to enhance the degradation of phenanthrene and pyrene in acidic soil inoculated with a bacterial strain (Pseudomonas putida MUB1) capable of degrading polycyclic aromatic hydrocarbons (PAHs). Planting with corn, inoculating with MUB1, ora combination of the two were found to promote the degradation of phenanthrene and pyrene in acidic soil at different rates. In the presence of corn plants, the rates of phenanthrene and pyrene removal were 41.7 and 38.8% in the first 10 days, while the rates were 58.8 and 53.6%, respectively in the treatment which received MUB1 only. After 60 days, the corn + MUB1 treatment led to the greatest reduction in both phenanthrene and pyrene biodegradation (89 and 88.2%, respectively). In control autoclaved soil, the rates of phenanthrene and pyrene removal were 14.2 and 28.7%, respectively while in non-autoclaved soil, the rates were 68.7 and 53.2%, respectively. These results show that corn, which was previously shown to grow well in PAH-contaminated acidic soil, also can enhance PAH degradation in such soil. Inoculation with a known PAH degrader further enhanced PAH degradation in the presence of corn.

  14. Bioventing remediation and ecotoxicity evaluation of phenanthrene-contaminated soil.

    PubMed

    García Frutos, F Javier; Escolano, Olga; García, Susana; Babín, Mar; Fernández, M Dolores

    2010-11-15

    The objectives of soil remediation processes are usually based on threshold levels of soil contaminants. However, during remediation processes, changes in bioavailability and metabolite production can occur, making it necessary to incorporate an ecotoxicity assessment to estimate the risk to ecological receptors. The evolution of contaminants and soil ecotoxicity of artificially phenanthrene-contaminated soil (1000 mg/kg soil) during soil treatment through bioventing was studied in this work. Bioventing was performed in glass columns containing 5.5 kg of phenanthrene-contaminated soil and uncontaminated natural soil over a period of 7 months. Optimum conditions of mineralisation (humidity=60% WHC; C/N/P=100:20:1) were determined in a previous work. The evolution of oxygen consumption, carbon dioxide production, phenanthrene concentration and soil toxicity were studied on sacrificed columns at periods of 0, 3 and 7 months. Toxicity to soil and aquatic organisms was determined using a multispecies system in the soil columns (MS-3). In the optimal bioventing treatability test, we obtained a reduction rate in phenanthrene concentration higher that 93% after 7 months of treatment. The residual toxicity obtained at the end of the treatment was not attributed to the low phenanthrene concentration, but to the ammonia used to restore the optimal C/N ratio.

  15. Biodegradation kinetics of phenanthrene by a fusant strain.

    PubMed

    Lu, Jing; Dang, Zhi; Lu, Guining; Yang, Chen; Yi, Xiaoyun; Guo, Chuling

    2012-09-01

    The fusant strain (F14), which produced by protoplast fusion between Sphingomonas sp. GY2B (GenBank DQ139343) and Pseudomonas sp. GP3A (GenBank EU233280), was tested for phenanthrene biodegradation at 30 °C and pH of 7.0. The kinetics of phenanthrene biodegradation by F14 was investigated over a wide range of initial concentration (15-1,000 mg l(-1)). The rate and the extent of phenanthrene degradation increased with the increase of concentration up to 230 mg l(-1), which indicated negligible inhibition effect at low concentrations. The non-competitive inhibition model was found to be fit for the process. GC-MS analysis showed that biodegradation of phenanthrene by F14 was via dioxygenation at both 1,2- and 3,4-positions and followed by 2-hydroxy-1-naphthoic acid and 1-hydroxy-2-naphthoic acid. The relative intensity of 2-hydroxy-1-naphthoic acid was approximately 3-4 times higher than that of 1-hydroxy-2-naphthoic acid, indicating the 2-hydroxy-1-naphthoic acid was the predominant product in the phenanthrene degradation by fusant strain F14.

  16. Poly(styrene)/oligo(fluorene)-intercalated fluoromica hybrids: synthesis, characterization and self-assembly

    PubMed Central

    Porzio, William; Scavia, Guido; Barba, Luisa; Arrighetti, Gianmichele; Ricci, Giovanni; Botta, Chiara

    2014-01-01

    Summary We report on the intercalation of a cationic fluorescent oligo(fluorene) in between the 2D interlayer region of a fluoromica type silicate. The formation of intercalated structures with different fluorophore contents is observed in powders by synchrotron radiation XRD. Successively, the hybrids are dispersed in poly(styrene) through in situ polymerization. Such a procedure allows us to synthesize the materials from solution, to achieve solid films, and to characterize them by optical and morphologic techniques. The polymeric films with homogeneous distribution of the hybrids exhibit ultraviolet–blue photoluminescence with a significantly enhanced photostability compared to the bare oligo(fluorene)s. Finally, under specific conditions, the polymer hybrid with higher oligo(fluorene) content spontaneously assembles into highly ordered microporous films. PMID:25671140

  17. Degradation of aromatic hydrocarbons by Sphingomonas paucimobilis strain EPA505.

    PubMed

    Story, S P; Kline, E L; Hughes, T A; Riley, M B; Hayasaka, S S

    2004-08-01

    To determine the substrate range capability of Sphingomonas paucimobilis strain EPA505, a number of aromatic compounds were tested as potential growth substrates. Strain EPA505 grew on phenanthrene, naphthalene, fluoranthene, toluene, benzoic acid, 2,3- and 3,4-dihydroxybenzoic acids, 1-chloro-2,4-dinitrobenzene, anthracene, 2-hydroxy-3-naphthoic acid and 1-hydroxy- 2-naphthoic acid, salicylic acid, and catechol. Strain EPA505 was unable to grow on coumarine 3-carboxylic acid, naphthalene dicarboxylic acid, acenaphthene, chrysene, pyrene, benzo[b]fluoranthene, and fluorene. Catabolic products were not detected or identified when the bacterium was incubated with coumarine 3-carboxylic acid, naphthalene dicarboxylic acid, acenaphthene, chrysene, or benzo[b]fluoranthene. Dihydroxypyrene, the ortho ring fission product of pyrene, and 10-hydroxy-1- phenanthroic acid were detected when the bacterium was incubated with pyrene. The open rings of benzo[b]fluoranthene, hydroxyacephenanthroic acid, hydroxyacephenanthrene, and phenanthrene anhydride, catabolites of benzo[b]fluoranthene degradation, were detected with Tn5 mutants of EPA505. With strain EPA505, both 9-fluorenone and an open ring fission product accumulated during incubation with fluorene. Other catabolites beyond the open ring of fluorene were detected, specifically dihydroxyfluorene, hydroxy-9-fluorenone, dihydroxy-9-fluorenone, hydroxyindane, and a putative glutathione-conjugated benzylanhydride. Benzylanhydride appeared to be a final end product of fluorene degradation by strain EPA505.

  18. The Effect of the Moisture Regime on the Interaction of Fluorene with Porous Media.

    PubMed

    Giat, Vered; Mingelgrin, Uri

    2015-07-01

    Movement and persistence of organic molecules in porous media is strongly influenced by their interactions with the solid phase. Understanding these interactions is important for the execution of reliable risk assessments and for proper handling and disposal of toxic organic chemicals. Transport and attenuation models often assume rapid adsorption-desorption equilibration and neglect the role of the ever-changing moisture regime at the top of the vadose zone. Adsorption of the polyaromatic hydrocarbon fluorene (CH), both from hexane and from water, on a cattle manure compost and on two soils-Dor (montmorillonitic, 1.9% organic matter [OM]) and Maagan-Michael (kaolinitic, 5.2% OM)-was studied. Adsorption from hexane mimics interactions with surfaces exposed to a gas phase or to an apolar liquid. Desorption was measured after loading the sorbents with fluorene dissolved in hexane, evaporating the solvent, and incubation in the wet state (above saturation of the porous medium), air-dried, or while undergoing wetting-drying cycles. Although good correlation was observed between the adsorption coefficient of fluorene from water and OM content, adsorption from hexane highly correlated with the surface charge density of the sorbent (its cation exchange capacity or its polarity). When added to the sorbents from hexane and then desorbed into water, less fluorene desorbed than predicted by its aqueous adsorption isotherms. Desorption from all sorbents decreased as the duration of incubation at air dryness increased. Thus, fluorene exhibited adsorption-desorption hysteresis, and a particularly strong adsorption-desorption hysteresis was exhibited by fluorene-loaded Maagan-Michael soil after undergoing wetting-drying cycles. PMID:26437097

  19. Relative role of eukaryotic and prokaryotic microorganisms in phenanthrene transformation in coastal sediments

    SciTech Connect

    MacGillivray, A.R.; Shiaris, M.P. )

    1994-04-01

    The relative role of eukaryotic versus prokaryotic microorganisms in phenanthrene transformation was measured in slurries of coastal sediment by two different approaches: detection of marker metabolites and use of selective inhibitors on phenanthrene biotransformation. Phenanthrene biotransformation was measured by polar metabolite formation and CO[sub 2] evolution from [9-[sup 14]C]phenanthrene. Both yeasts and bacteria transformed phenanthrene in slurries of coastal sediment. Two products of phenanthrene oxidation by fungi, phenanthrene trans-3,4-dihydrodiol and 3-phenanthrol, were produced in yeast-inoculated sterile sediment. However, only products of phenanthrene oxidation typical of bacterial transformation, 1-hydroxy-2-naphthoic acid and phenanthrene cis-3,4-dihydrodiol, were isolated from slurries of coastal sediment with natural microbial populations. Phenanthrene trans-dihydrodiols or other products of fungal oxidation of phenanthrene were not detected in the slurry containing a natural microbial population. A predominant role for bacterial transformation of phenanthrene was also suggested from selective inhibitor experiments. Addition of streptomycin to slurries, at a concentration which suppressed bacterial viable counts and rates of [methyl-[sup 3]H]thymidine uptake, completely inhibited phenanthrene transformation. Treatment with colchicine, at a concentration which suppressed yeast viable counts, depressed phenanthrene transformation by 40%, and this was likely due to nontarget inhibition of bacterial activity. The relative contribution of eukaryotic microorganisms to phenanthrene transformation in inoculated sterile sediment was estimated to be less than 3% of the total activity. We conclude that the predominant degraders of phenanthrene in muddy coastal sediments are bacteria and not eukaryotic microorganisms. 35 refs., 2 figs., 1 tab.

  20. Modeling of supercritical fluid extraction of phenanthrene from clayey soil.

    PubMed

    Elektorowicz, Maria; El-Sadi, Haifa; Ayadat, Tahar

    2008-05-01

    The supercritical fluid (SFC) extraction efficiency of phenanthrene from clayey soils was modeled. The model accounts for effective diffusion of the phenanthrene in the solid pores, axial dispersion in the fluid phase, and external mass transfer to the fluid phase from the particle surface. This model, involving partial differential equations, was solved using the finite difference. The model showed the relationship between diffusivity, mass transfer coefficient, and properties of porous media (clay texture). The porous media analysis was performed with a microscope and by an image analysis. The proposed model compared well with the experimental data available in the literature. PMID:18366027

  1. Modeling of supercritical fluid extraction of phenanthrene from clayey soil.

    PubMed

    Elektorowicz, Maria; El-Sadi, Haifa; Ayadat, Tahar

    2008-05-01

    The supercritical fluid (SFC) extraction efficiency of phenanthrene from clayey soils was modeled. The model accounts for effective diffusion of the phenanthrene in the solid pores, axial dispersion in the fluid phase, and external mass transfer to the fluid phase from the particle surface. This model, involving partial differential equations, was solved using the finite difference. The model showed the relationship between diffusivity, mass transfer coefficient, and properties of porous media (clay texture). The porous media analysis was performed with a microscope and by an image analysis. The proposed model compared well with the experimental data available in the literature.

  2. Donor/Acceptor Dihydroindeno[1,2-a]fluorene and Dihydroindeno[2,1-b]fluorene: Towards New Families of Organic Semiconductors.

    PubMed

    Romain, Maxime; Tondelier, Denis; Geffroy, Bernard; Jeannin, Olivier; Jacques, Emmanuel; Rault-Berthelot, Joëlle; Poriel, Cyril

    2015-06-22

    New families of donor/acceptor semiconductors based on dihydroindeno[1,2-a]fluorene and dihydroindeno[2,1-b]fluorene are reported. Due to the spiro bridges, this new generation of dihydroindenofluorenes allows a spatial separation of HOMO and LUMO, which retains the high ET value of the dihydroindenofluorene backbone and excellent physical properties. This control of the electronic and physical properties has allowed a second generation of dihydroindeno[1,2-a]fluorene to be obtained with strongly enhanced performance in green and sky-blue phosphorescent organic light-emitting diodes (PhOLEDs) relative to the first generation of materials. To date, this is the highest performance ever reported for a blue PhOLED by using a dihydroindenofluorene derivative. Through this structure-property relationship study, a remarkable difference of performance between syn and anti isomers has also been highlighted. This surprising behaviour has been attributed to the different symmetry of the two molecules, and highlights the importance of the geometry profiles in the design of host materials for PhOLEDs. PMID:26012479

  3. Modular Approach to 9-Monosubstituted Fluorene Derivatives Using Mo(V) Reagents.

    PubMed

    Franzmann, Peter; Trosien, Simon; Schubert, Moritz; Waldvogel, Siegfried R

    2016-03-01

    Oxidative coupling using molybdenum(V) reagents provides fast access to highly functionalized 9-monosubstituted fluorenes. This synthetic approach is highly modular, is high yielding, and tolerates a variety of labile moieties, e.g. amides or iodo groups. The established protocol leads to promising precursors for pharmacologically important analogues of melatonin. PMID:26913835

  4. Fluorene biodegradation and identification of transformation products by white-rot fungus Armillaria sp. F022.

    PubMed

    Hadibarata, Tony; Kristanti, Risky Ayu

    2014-06-01

    A diverse surfactant, including the nonionic Tween 80 and Brij 30, the anionic sodium dodecyl sulphate, the cationic surfactant Tetradecyltrimethylammonium bromide, and biosurfactant Rhamnolipid were investigated under fluorine-enriched medium by Armilaria sp. F022. The cultures were performed at 25 °C in malt extract medium containing 1 % of surfactant and 5 mg/L of fluorene. The results showed among the tested surfactants, Tween-80 harvested the highest cell density and obtained the maximum specific growth rate. This due Tween-80 provide a suitable carbon source for fungi. Fluorane was also successfully eliminated (>95 %) from the cultures within 30 days in all flasks. During the experiment, laccase production was the highest among other enzymes and Armillaria sp. F022-enriched culture containing Non-ionic Tween 80 showed a significant result for laccase activity (1,945 U/L). The increased enzyme activity was resulted by the increased biodegradation activity as results of the addition of suitable surfactants. The biotransformation of fluorene was accelerated by Tween 80 at the concentration level of 10 mg/L. Fluorene was initially oxidized at C-2,3 positions resulting 9-fluorenone. Through oxidative decarboxylation, 9-fluorenone subjected to meta-cleavage to form salicylic acid. One metabolite detected in the end of experiment, was identified as catechol. Armillaria sp. F022 evidently posses efficient, high effective degrader and potential for further application on the enhanced bioremediation technologies for treating fluorene-contaminated soil.

  5. New spiro[benzotetraphene-fluorene] derivatives: synthesis and application in sky-blue fluorescent host materials.

    PubMed

    Cha, Jae-Ryung; Lee, Chil-Won; Gong, Myoung-Seon

    2014-07-01

    Blue light-emitting spiro[benzotetraphene-fluorene] (SBTF)-based host materials, 3-(1-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9'-fluorene] (1), 3-(2-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9'-fluorene] (2), and 3-[2-(6-phenyl)naphthyl]-10-naphthylspiro[benzo[ij]tetraphene-7,9'-fluorene] (3) were designed and prepared via multi-step Suzuki coupling reactions. Introducing various aromatic groups into SBTF core lead to a reduction in band gap and a determination of the color purity and luminescence efficiency. Typical sky-blue fluorescent organic light emitting diodes with the configuration of ITO/N,N'-di(1-naphthyl)-N,N'-bis[(4-diphenylamino)phenyl]-biphenyl-4,4'-diamie (60 nm)/N,N,N',N'-tetra(1-biphenyl)-biphenyl-4,4'-diamine (30 nm)/host: dopant (30 nm, 5%)/LG201 (electron transporting layer, 20 nm)/LiF/Al were developed using SBTF derivatives as a host material and p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) as a sky-blue dopant material. A device obtained from three materials doped with DSA-Ph showed color purity of 0.148 and 0.239, a luminance efficiency of 7.91 cd/A, and an external quantum efficiency >4.75% at 5 V. PMID:24859632

  6. Two-stage mineralization of phenanthrene by estuarine enrichment cultures

    SciTech Connect

    Guerin, W.F.; Jones, G.E.

    1988-04-01

    The polycyclic aromatic hydrocarbon phenanthrene was mineralized in two stages by soil, estuarine water, and sediment microbial populations. At high concentrations, phenanthrene was degraded, with the concomitant production of biomass and accumulation of Folin-Ciocalteau-reactive aromatic intermediates. Subsequent consumption of these intermediates resulted in a secondary increase in biomass. Analysis of intermediates by high-performance liquid chromatography, thin-layer chromatography, and UV absorption spectrometry showed 1-hydroxy-2-naphthoic acid (1H2NA) to be the predominant product. A less pronounced two-stage mineralization pattern was also observed by monitoring /sup 14/CO/sub 2/ production from low concentrations (0.5 mg liter/sup -1/) of radiolabeled phenanthrene. Here, mineralization of /sup 14/C-labeled 1H2NA could explain the incremental /sup 14/CO/sub 2/ produced during the later part of the incubations. Accumulation of 1H2NA by isolates obtained from enrichments was dependent on the initial phenanthrene concentration. The production of metabolites during polycyclic aromatic hydrocarbon biodegradation is discussed with regard to its possible adaptive significance and its methodological implications.

  7. Two-stage mineralization of phenanthrene by estuarine enrichment cultures.

    PubMed

    Guerin, W F; Jones, G E

    1988-04-01

    The polycyclic aromatic hydrocarbon phenanthrene was mineralized in two stages by soil, estuarine water, and sediment microbial populations. At high concentrations, phenanthrene was degraded, with the concomitant production of biomass and accumulation of Folin-Ciocalteau-reactive aromatic intermediates. Subsequent consumption of these intermediates resulted in a secondary increase in biomass. Analysis of intermediates by high-performance liquid chromatography, thin-layer chromatography, and UV absorption spectrometry showed 1-hydroxy-2-naphthoic acid (1H2NA) to be the predominant product. A less pronounced two-stage mineralization pattern was also observed by monitoring CO(2) production from low concentrations (0.5 mg liter) of radiolabeled phenanthrene. Here, mineralization of C-labeled 1H2NA could explain the incremental CO(2) produced during the later part of the incubations. Accumulation of 1H2NA by isolates obtained from enrichments was dependent on the initial phenanthrene concentration. The production of metabolites during polycyclic aromatic hydrocarbon biodegradation is discussed with regard to its possible adaptive significance and its methodological implications.

  8. Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6

    PubMed Central

    Gao, Shumei; Seo, Jong-Su; Wang, Jun; Keum, Young-Soo; Li, Jianqiang; Li, Qing X.

    2013-01-01

    Stenotrophomonas maltophilia strain C6, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from creosote-contaminated sites at Hilo, Hawaii. Twenty-two metabolites of phenanthrene, covering from dihydrodiol to protocatechuic acid, were isolated and characterized. Phenanthrene was degraded via an initial dioxygenation on 1,2-, 3,4-, and 9,10-C, where the 3,4-dioxygenation and subsequent metabolisms were most dominant. The metabolic pathways were further branched by ortho- and meta-cleavage of phenanthrenediols to produce 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, and naphthalene-1,2-dicarboxylic acid. These intermediates were then transformed to naphthalene-1,2-diol. 1-Hydroxy-2-naphthoic acid was also degraded via a direct ring cleavage. Naphthalene-1,2-diol underwent primarily ortho-cleavage to produce trans-2-carboxycinnamic acid and then to form phthalic acid, 4,5-dihydroxyphthalic acid and protocatechuic acid. Accumulation of salicylic acid in prolonged incubation indicated that a limited extent of meta-cleavage of naphthalene-1, 2-diol also occurred. This is the first study of detailed phenanthrene metabolic pathways by Stenotrophomonas maltophilia. PMID:23539472

  9. Effect of Cosolutes on the Sorption of Phenanthrene onto Mineral Surface of River Sediments and Kaolinite

    PubMed Central

    2014-01-01

    Sorption of phenanthrene onto the natural sediment with low organic carbon content (OC%), organic-free sediment, and kaolinite was investigated through isotherm experiments. Effects of cosolutes (pyrene, 4-n-nonyphenol (NP), and humic acid (HA)) on phenanthrene sorption were also studied by comparing apparent solid-water distribution coefficients (Kdapp) of phenanthrene. Two addition sequences, including “cosolute added prior to phenanthrene” and “cosolute and phenanthrene added simultaneously,” were adopted. The Freundlich model fits phenanthrene sorption on all 3 sorbents well. The sorption coefficients on these sorbents were similar, suggesting that mineral surface plays an important role in the sorption of hydrophobic organic contaminants on low OC% sediments. Cosolutes could affect phenanthrene sorption on the sorbents, which depended on their properties, concentrations, and addition sequences. Pyrene inhibited phenanthrene sorption. Sorbed NP inhibited phenanthrene sorption at low levels and promoted sorption at high levels. Similar to NP, effect of HA on phenanthrene sorption onto the natural sediment depended on its concentrations, whereas, for the organic-free sediment and kaolinite, preloading of HA at high levels led to an enhancement in phenanthrene Kdapp while no obvious effect was observed at low HA levels; dissolved HA could inhibit phenanthrene sorption on the two sorbents. PMID:25147865

  10. Study of the degradation activity and the strategies to promote the bioavailability of phenanthrene by Sphingomonas paucimobilis strain 20006FA.

    PubMed

    Coppotelli, Bibiana M; Ibarrolaza, Agustin; Dias, Romina L; Del Panno, Maria T; Berthe-Corti, Luise; Morelli, Irma S

    2010-02-01

    The present study describes the phenanthrene-degrading activity of Sphingomonas paucimobilis 20006FA and its ability to promote the bioavailability of phenanthrene. S. paucimobilis 20006FA was isolated from a phenanthrene-contaminated soil microcosm. The strain was able to grow in liquid mineral medium saturated with phenanthrene as the sole carbon source, showing high phenanthrene elimination (52.9% of the supplied phenanthrene within 20 days). The accumulation of 1-hydroxy-2-naphthoic acid and salicylic acid as major phenanthrene metabolites and the capacity of the strain to grow with sodium salicylate as the sole source of carbon and energy indicated that the S. paucimobilis 20006FA possesses a complete phenanthrene degradation pathway. However, under the studied conditions, the strain was able to mineralize only the 10% of the consumed phenanthrene. Investigations on the cell ability to promote bioavailability of phenanthrene showed that the S. paucimobilis strain 20006FA exhibited low cell hydrophobicity (0.13), a pronounced chemotaxis toward phenanthrene, and it was able to reduce the surface tension of mineral liquid medium supplemented with phenanthrene as sole carbon source. Scanning electron micrographs revealed that: (1) in suspension cultures, cells formed flocks and showed small vesicles on the cell surface and (2) cells were also able to adhere to phenanthrene crystals and to produce biofilms. Clearly, the strain seems to exhibit two different mechanisms to enhance phenanthrene bioavailability: biosurfactant production and adhesion to the phenanthrene crystals.

  11. Regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4

    SciTech Connect

    Resnick, S.M.; Gibson, D.T.

    1996-11-01

    Fluorene, dibenzofuran, dibenzothiophene, and carbazole are structural analogs differing only in the type of atom bridging the two aromatic rings. These compounds are constituents of fossil fuels. The authors have examined the oxidation of fluorene, dibenzofuran, and dibenzothiophene by mutant and recombinant strains which express NDO from Pseudomonas sp. strain NCIB 9816-4 and reports the yields, region chemistry, absolute stereochemistry, and enantiomeric purity of the isolated initial metabolites. 71 refs., 3 figs., 2 tabs.

  12. Evaluation of matrices for the sorption and biodegradation of phenanthrene.

    PubMed

    Leglize, Pierre; Saada, Alain; Berthelin, Jacques; Leyval, Corinne

    2006-07-01

    Permeable reactive barriers (PRBs), a new cost effective technology for the remediation of contaminated groundwater, have rarely been considered for PAH contamination. We evaluated three candidate matrices (activated carbon (AC), pouzzolana coated (PzF) or not (Pz) with heavy fuel oil) for phenanthrene (PHE) sorption capacity and the biodegradation of adsorbed PHE. Adsorption-desorption batch experiments showed higher sorption capacity of AC than PzF (60 fold) and Pz (1,500 fold). Sorption isotherms were not linear for all matrices as described by a Freundlich model. Phenanthrene desorption from AC and PzF within 48 h was limited (1-3%). Mineralization of (14)C-PHE by a PAH-degrading bacterial strain increased in the presence of AC and Pz (+16 and +12%). Among the three matrices, AC may be a good candidate for PRBs due to high adsorption, low desorption and increased PHE degradation.

  13. A new boronic acid fluorescent sensor based on fluorene for monosaccharides at physiological pH

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona; Eslami, Abbas; Emami, Saeed

    2015-06-01

    Fluorescent boronic acids are very useful fluorescent sensor for detection of biologically important saccharides. Herein we synthesized a new fluorene-based fluorescent boronic acid that shows significant fluorescence changes upon addition of saccharides at physiological pH. Upon addition of fructose, sorbitol, glucose, galactose, ribose, and maltose at different concentration to the solution of 7-(dimethylamino)-9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (7-DMAFBA, 1), significant decreases in fluorescent intensity were observed. It was found that this boronic acid has high affinity (Ka = 3582.88 M-1) and selectivity for fructose over glucose at pH = 7.4. The sensor 1 showed a linear response toward D-fructose in the concentrations ranging from 2.5 × 10-5 to 4 × 10-4 mol L-1 with the detection limit of 1.3 × 10-5 mol L-1.

  14. Rational Design of Push-Pull Fluorene Dyes: Synthesis and Structure-Photophysics Relationship.

    PubMed

    Shaya, Janah; Fontaine-Vive, Fabien; Michel, Benoît Y; Burger, Alain

    2016-07-18

    Our work surveyed experimental and theoretical investigations to construct highly emissive D-π-A (D=donor, A=acceptor) fluorenes. The synthetic routes were optimised to be concise and gram-scalable. The molecular design was first rationalised by varying the electron-withdrawing group from an aldehyde, ketotriazole or succinyl to methylenemalonitrile or benzothiadiazole. The electron-donating group was next varied from aliphatic or aromatic amines to saturated cyclic amines ranging from aziridine to azepane. Spectroscopic studies correlated with TD-DFT calculations provided the optimised structures. The selected push-pull dyes exhibited visible absorptions, significant brightness, important solvatofluorochromism, mega-Stokes shifts (>250 nm) and dramatic shifts in emission to the near-infrared. The current library includes the comprehensive characterization of 16 prospective dyes for fluorescence applications. Among them, several fluorene derivatives bearing different conjugation anchors were tested for coupling and demonstrated to preserve the photophysical responses once further bound.

  15. Construction of logic gates with the fluorene-based small molecule/DNA probes.

    PubMed

    Guo, Jing; Wang, Ting; Yang, Renqiang

    2012-09-01

    Fluorene-based small molecules (FSMs) have optical properties and can interact with DNA. In this paper, the integrated "INH" and "AND" gates operating in parallel are developed with the fluorene-based small molecule (FSM)/DNA probe. They are activated by taking advantage of the two-step fluorescence resonance energy transfer (FRET) process and the sequence-recognition mechanism of DNA. Then, a "NOT" gate is obtained with a molecular beacon-like probe (FSM-MB) by using the FSM as the fluorophore. Moreover, the "NOT" gate based on the FSM-MB probe can be used as a biosensor and has potential applications in label-free detection of target molecules.

  16. Infrared Absorption Spectrum of Matrix-Isolated Phenanthrene

    NASA Astrophysics Data System (ADS)

    Zhang, Xu; Stanley P. Sander

    2016-10-01

    The far-to-mid Infrared absorption spectrum of phenanthrene (C14H10), one of the polycyclic aromatic hydrocarbons (PAHs), has been measured in an argon matrix at 5 K. Thirty two fundamental bands for phenanthrene have been observed; one of them is detected for the first time (v54 = 1398.0 cm-1) and eight of them are detected for the first time at temperatures below room temperature (v43 = 233.8 cm-1, v42 = 425.2 cm-1, v66 = 441.6 cm-1, v65 = 499.0 cm-1, v21 = 546.3 cm-1, v63 = 714.5 cm-1, v18 = 1033.7 cm-1 and v55 = 1362.5 cm-1). The relative intensities of these 32 bands have been measured; three ( v21, v18, v54) of which are measured for the first time and six ( v43, v42, v66, v65, v63, and v55) of which are measured for the first time at temperatures below room temperature. Our low temperature study of the vibrational bands for phenanthrene provides important information for the spectral analysis of the Composite Infrared Spectrometer (CIRS) aboard the Cassini Spacecraft.

  17. Anti-inflammatory phenanthrene derivatives from stems of Dendrobium denneanum.

    PubMed

    Lin, Yuan; Wang, Fei; Yang, Li-Juan; Chun, Ze; Bao, Jin-Ku; Zhang, Guo-Lin

    2013-11-01

    Cultivated Dendrobium denneanum has been substituted for other endangered Dendrobium species in recent years, but there have been few studies regarding either its chemical constituents or pharmacological effects. In this study, three phenanthrene glycosides, three 9,10-dihydrophenanthrenes, two 9,10-dihydrophenanthrenes glycosides, and four known phenanthrene derivatives, were isolated from the stems of D. denneanum. Their structures were elucidated on the basis of MS and NMR spectroscopic data. Ten compounds were found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated mouse macrophage RAW264.7 cells with IC50 values of 0.7-41.5 μM, and exhibited no cytotoxicity in RAW264.7, HeLa, or HepG2 cells. Additionally, it was found that 2,5-dihydroxy-4-methoxy-phenanthrene 2-O-β-d-glucopyranoside, and 5-methoxy-2,4,7,9S-tetrahydroxy-9,10-dihydrophenanthrene suppressed LPS-induced expression of inducible NO synthase (iNOS) inhibited phosphorylation of p38, JNK as well as mitogen-activated protein kinase (MAPK), and inhibitory kappa B-α (IκBα). This indicated that both compounds exert anti-inflammatory effects by inhibiting MAPKs and nuclear factor κB (NF-κB) pathways. PMID:24042064

  18. Plasmid-mediated mineralization of naphthalene, phenanthrene, and anthracene.

    PubMed Central

    Sanseverino, J; Applegate, B M; King, J M; Sayler, G S

    1993-01-01

    The well-characterized plasmid-encoded naphthalene degradation pathway in Pseudomonas putida PpG7(NAH7) was used to investigate the role of the NAH plasmid-encoded pathway in mineralizing phenanthrene and anthracene. Three Pseudomonas strains, designated 5R, DFC49, and DFC50, were recovered from a polynuclear aromatic hydrocarbon-degrading inoculum developed from a manufactured gas plant soil slurry reactor. Plasmids pKA1, pKA2, and pKA3, approximately 100 kb in size, were isolated from these strains and characterized. These plasmids have homologous regions of upper and lower NAH7 plasmid catabolic genes. By conjugation experiments, these plasmids, including NAH7, have been shown to encode the genotype for mineralization of [9-14C]phenanthrene and [U-14C]anthracene, as well as [1-14C]naphthalene. One strain, Pseudomonas fluorescens 5RL, which has the complete lower pathway inactivated by transposon insertion in nahG, accumulated a metabolite from phenanthrene and anthracene degradation. This is the first direct evidence to indicate that the NAH plasmid-encoded catabolic genes are involved in degradation of polynuclear aromatic hydrocarbons other than naphthalene. Images PMID:8328809

  19. Sublethal effects of phenanthrene, nicotine, and pinane on Daphnia pulex

    SciTech Connect

    Savino, J.F.; Tanabe, L.L. )

    1989-05-01

    Nearly 500 compounds were detected in the tissues of Great Lakes fish as compared to 8 in tissues of hatchery-reared fish. Lethal concentrations for many representative compounds were determined by testing their acute toxicity (48-hr EC50) to Daphnia pulex. However, the population growth and survival of aquatic organisms over longer time intervals are usually affected at concentrations much lower than the EC50 for a specific chemical. To develop a general relationship between acute and chronic concentrations for representative compounds detected in Great Lakes fish, the authors initiated full-life-cycle testing on D. pulex with phenanthrene, nicotine, and pinane. Growth and fecundity of daphnids was measured in 16-d tests in the laboratory. Phenanthrene and nicotine were highly toxic and pinane was moderately toxic to D. pulex in acute studies. For phenanthrene, a compound of the polycyclic aromatic hydrocarbons (PAHs) that has been associated with incomplete combustion of organic matter. For nicotine, a compound in the heterocyclic nitrogen class of chemicals that has been used as an insecticide, the EC50 was 0.24 mg/L. Cyclic alkanes, many of which are constituents of crude oil were represented by pinane for which the EC50 was 3.35 mg/L.

  20. Phenanthrene and pyrene oxidation in contaminated soils using Fenton's reagent.

    PubMed

    Silva, Paula Tereza de Souza E; Silva, Valdinete Lins da; Neto, Benício de Barros; Simonnot, Marie-Odile

    2009-01-30

    Fenton's reagent has shown its applicability to oxidizing these biorefractory organic contaminants. The purpose of this contribution was to investigate the influence of operating parameters on the process efficiency for soil highly contaminated by PAHs. Five variables were selected: pH, reaction time, UV irradiation, hydrogen peroxide concentration and Fe (II) amendment. Their effects on the oxidation of (i) phenanthrene and on (ii) phenanthrene and pyrene present in freshly contaminated soil samples were studied through batch reactor experiments following factorial designs. For phenanthrene oxidation run with a soil contaminated at 700 mg kg(-1), one set of variables enabled us to reach a residual concentration lower than 40 mg kg(-1) (Dutch legislation threshold). The most important factor was the reaction time, followed at a certain distance by UV irradiation, Fe (II), H(2)O(2) concentration and pH, this last variable being the least significant. The possibility of operating without pH adjustment is of importance in the treatment at the field scale. This shows the feasibility of photo-Fenton-like oxidation for the treatment of soil highly contaminated with PAH and the relative importance of the process variables. PMID:18524479

  1. Induction of PAH degradation in a phenanthrene-degrading pseudomonad

    SciTech Connect

    Stringfellow, W.T.; Chen, S.H.; Aitken, M.D.

    1995-12-31

    Recent evidence suggests that different polycyclic aromatic hydrocarbon (PAH) substrates are metabolized by common enzymes in PAH-degrading bacteria, implying that inducers for low-molecular-weight PAH degradation may coinduce for the metabolism of higher-molecular-weight compounds. The authors have tested this hypothesis with a well-characterized PAH-degrading bacterium, Pseudomonas saccharophila P-15. Growth of P-15 on salicylate, a metabolite of phenanthrene degradation, and a known inducer for naphthalene degradation, induced the metabolism of both substrates. Several potential inducers were then tested for their effects on metabolism of the four-ring compounds pyrene and fluoranthene, neither of which is a growth substrate for P-15, but both of which can be metabolized by this organism. Incubation of P-15 in the presence of phenanthrene or salicylate induced the metabolism of pyrene and fluoranthene in resting-cell assays. Catechol, another intermediate of naphthalene and phenanthrene degradation, did not induce the metabolism of either compound and interfered with the inducing effect of salicylate. These results have implications for strategies designed to maintain PAH degradation in contaminated environments, particularly for compounds that are degraded slowly or are degraded only by nongrowth metabolism.

  2. Characterising the exchangeability of phenanthrene associated with naturally occurring soil colloids using an isotopic dilution technique.

    PubMed

    Tavakkoli, Ehsan; Juhasz, Albert; Donner, Erica; Lombi, Enzo

    2015-04-01

    The association of polycyclic aromatic hydrocarbons (PAHs) with inorganic and organic colloids is an important factor influencing their bioavailability, mobility and degradation in the environment. Despite this, our understanding of the exchangeability and potential bioavailability of PAHs associated with colloids is limited. The objective of this study was to use phenanthrene as a model PAH compound and develop a technique using (14)C phenanthrene to quantify the isotopically exchangeable and non-exchangeable forms of phenanthrene in filtered soil water or sodium tetraborate extracts. The study was also designed to investigate the exchangeability of colloidal phenanthrene as a function of particle size. Our findings suggest that the exchangeability of phenanthrene in sodium tetraborate is controlled by both inorganic and organic colloids, while in aqueous solutions inorganic colloids play the dominant role (even though coating of these by organic matter cannot be excluded). Filter pore size did not have a significant effect on phenanthrene exchangeability.

  3. Sublethal responses of the striped mullet (Mugil cephalus L. ) to fluorene analogs

    SciTech Connect

    Wofford, H.W.

    1981-01-01

    Juvenile striped mullet (Mugil cephalus) were exposed for up to 12 days to 10 to 10,000 ..mu..g/l fluorene and three fluorene analogs (dibenzofuran, carbazole, and dibenzothiophene). These constituents of oil and coal were all acutely toxic to mullet at concentrations below their maximum solubility in seawater. The relative toxicity of the four analogs was related to their lipophilic nature and chemical reactivity. These pollutants were capable of inducing the corticosteroid stress response and resulting secondary stress responses in mullet. Plasma cortisol concentrations were significantly elevated, followed by a rise in plasma glucose. Responses were mild compared to those elicited by physical stress. Liver glycogen content was initially depressed, and later was restored to levels higher than the controls. Minor changes were observed in plasma lipids, with plasma triglyceride concentrations showing a consistent elevation upon exposure to dibenzofuran. Plasma osmolality was not significantly altered. Components of the xenobiotic metabolizing system of mullet were also affected by exposure to the four compounds. Large increases in liver glutathione concentration were observed, along with slight elevations in liver ascorbic acid content and ..beta..-glucuronidase activity. The fluorene analogs caused profound behavioral changes, which appeared to be related to a pharmacological effect on brain biogenic amine levels.

  4. Fluorene- and benzofluorene-cored oligomers as low threshold and high gain amplifying media

    SciTech Connect

    Kazlauskas, Karolis Kreiza, Gediminas; Bobrovas, Olegas; Adomėnienė, Ona; Adomėnas, Povilas; Juršėnas, Saulius; Jankauskas, Vygintas

    2015-07-27

    Deliberate control of intermolecular interactions in fluorene- and benzofluorene-cored oligomers was attempted via introduction of different-length alkyl moieties to attain high emission amplification and low amplified spontaneous emission (ASE) threshold at high oligomer concentrations. Containing fluorenyl peripheral groups decorated with different-length alkyl moieties, the oligomers were found to express weak concentration quenching of emission, yet excellent carrier drift mobilities (close to 10{sup −2} cm{sup 2}/V/s) in the amorphous films. Owing to the larger radiative decay rates (>1.0 × 10{sup 9 }s{sup −1}) and smaller concentration quenching, fluorene-cored oligomers exhibited down to one order of magnitude lower ASE thresholds at higher concentrations as compared to those of benzofluorene counterparts. The lowest threshold (300 W/cm{sup 2}) obtained for the fluorene-cored oligomers at the concentration of 50 wt % in polymer matrix is among the lowest reported for solution-processed amorphous films in ambient conditions, what makes the oligomers promising for lasing application. Great potential in emission amplification was confirmed by high maximum net gain (77 cm{sup −1}) revealed for these compounds. Although the photostability of the oligomers was affected by photo-oxidation, it was found to be comparable to that of various organic lasing materials including some commercial laser dyes evaluated under similar excitation conditions.

  5. 9-Phenyl-4,5-diaza-9H-fluoren-9-ol monohydrate

    PubMed Central

    Yin, Guo-Jie; Yang, Gang-Bin; Wang, Shi-Min

    2012-01-01

    The title compound, C17H12N2O·H2O, was synthesized by the reaction of 4,5-diaza­fluoren-9-one with a Grignard reagent in ether (the reaction mixture being hydrolysed with saturated NH4Cl solution), and crystallizes with two organic mol­ecules and two water mol­ecules in the asymmetric unit. The 4,5-diaza­fluorene fragment is approximately planar, with r.m.s. deviations of 0.0448 and 0.0198 Å in the two mol­ecules. The dihedral angles between the 4,5-diaza­fluorene planes and the phenyl ring are 80.49 (6) and 76.57 (7)°. The crystal packing features O—H⋯N and O—H⋯O hydrogen bonds involving the bridging solvent water mol­ecules, which link the mol­ecules into a three-dimensional network. PMID:22719589

  6. Optoelectronic properties of a novel fluorene derivative for organic light-emitting diode

    NASA Astrophysics Data System (ADS)

    Yu, Junsheng; Lou, Shuangling; Qian, Jincheng; Jiang, Yadong; Zhang, Qing

    2009-03-01

    We report the optoelectronic properties of a novel fluorene derivative of 6,6'-(9H-fluoren-9,9-diyl)bis(2,3-bis (9,9-dihexyl-9H-fluoren-2-yl)quinoxaline) (BFLBBFLYQ) used for organic light-emitting diode. UV-Vis absorption, photoluminescence (PL) and electroluminescence (EL) spectra of BFLBBFLYQ and the blend doped with N, N'-biphenyl- N, N'-bis-(3-methylphenyl)-1,1'-biphenyl-4,4'-di- amine (TPD) in solid state and in solution were investigated. The results showed that BFLBBFLYQ had a PL peak at 451 nm in solid and solution states and an EL peak at 483 nm with a broad emission band, resulting from fluorenone defects. Exciplex emission was observed in BFLBBFLYQ-TPD blend solid state with a green emission peaking at 530 nm. Also the blend in solution showed solvatochromism in polarity solvent upon UV irradiation. A new absorption band appeared at around 470 nm of BFLBBFLYQ-TPD blend in chloroform solution, and disappeared when diluted in absorption spectrum. Meanwhile, a low energy emission band from 530 to 580 nm appeared and increased with material concentration and UV irradiation time.

  7. Influence of hole transporter doping on electroluminescent property of novel fluorene molecular material

    NASA Astrophysics Data System (ADS)

    Qian, Jincheng; Yu, Junsheng; Lou, Shuangling; Jiang, Yadong; Zhang, Qing

    2009-05-01

    The luminescent characteristics of a novel small molecule fluorene material, 6,6'-(9H-fluoren-9,9-diyl)bis(2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)quinoxaline) (BFLBBFLYQ) for organic light-emitting diode are systemically investigated, especially focusing on the effect of hole transporter doping concentration. Double-layer devices with a structure of indium tin oxide (ITO)/emissive layer (EML)/2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline (BCP)/Mg:Ag are fabricated by spin-coating method, where EML is BFLBBFLYQ and blend of BFLBBFLYQ: N,N'-biphenyl-N,N'-bis-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), respectively. The results show that the performance of the device is improved two magnitudes by doping BFLBBFLYQ with TPD. In the electroluminescent (EL) spectra, the BFLBBFLYQ device show a blue light emission peaking at 485 nm, and the blend device exhibits a broad banded emission with 45 nm red-shifted peaking at 530 nm in green light area. The photoluminescent (PL) spectra of BFLBBFLYQ, TPD and BFLBBFLYQ: TPD blend in xylene solution and spin-coated film is also studied, yielding an evidence that exciplex maybe plays the role for low energy emission.

  8. Photoelectric characteristics of organic light-emitting device based on a small molecular fluorene derivative

    NASA Astrophysics Data System (ADS)

    Qian, Jincheng; Yu, Junsheng; Jiang, Yadong; Lou, Shuangling; Zhang, Qing

    2009-11-01

    The performance of organic light-emitting devices (OLEDs) based on a small molecular fluorene material, 6,6'-(9H-fluoren-9,9-diyl)bis(2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)quinoxaline) (BFLBBFLYQ), was investigated. Double-layer devices with a structure of indium tin oxide (ITO)/BFLBBFLYQ/2,9-dimethyl-4,7-diphenyl-l, 10-phenanthroline (BCP)/Mg:Ag were fabricated. To improve the performance of the OLEDs, N,N'-biphenyl-N,N'-bis-(3-methylphenyl)-1, 1'-biphenyl-4,4'-diamine (TPD) was introduced, and triple-layer OLEDs with a configuration of ITO/TPD/BFLBBFLYQ/BCP/Mg:Ag were fabricated. By analyzing the electric and luminescent properties of the devices with two different structures, it was found that the performance of triple-layer devices was higher than that of double-layer device. The electroluminescent (EL) spectra of the devices were also studied, which showed that the EL spectra red-shifted as the vacuum deposition temperature increased.

  9. Biostimulation as an attractive technique to reduce phenanthrene toxicity for meiofauna and bacteria in lagoon sediment.

    PubMed

    Louati, Hela; Said, Olfa Ben; Soltani, Amel; Got, Patrice; Cravo-Laureau, Cristiana; Duran, Robert; Aissa, Patricia; Pringault, Olivier; Mahmoudi, Ezzeddine

    2014-03-01

    A microcosm experiment was setup to examine (1) the effect of phenanthrene contamination on meiofauna and bacteria communities and (2) the effects of different bioremediation strategies on phenanthrene degradation and on the community structure of free-living marine nematodes. Sediments from Bizerte lagoon were contaminated with (100 mg kg(-1)) phenanthrene and effects were examined after 20 days. Biostimulation (addition of nitrogen and phosphorus fertilizer or mineral salt medium) and bioaugmentation (inoculation of a hydrocarbonoclastic bacterium) were used as bioremediation treatments. Bacterial biomass was estimated using flow cytometry. Meiofauna was counted and identified at the higher taxon level using a stereomicroscope. Nematodes, comprising approximately two thirds of total meiofauna abundance, were identified to genus or species. Phenanthrene contamination had a severe impact on bacteria and meiofauna abundances with a strong decrease of nematodes with a complete disappearance of polychaetes and copepods. Bioremediation counter balanced the toxic effects of phenanthrene since meiofauna and bacteria abundances were significantly higher (p < 0.01) than those observed in phenanthrene contamination. Up to 98 % of phenanthrene removal was observed. In response to phenanthrene contamination, the nematode species had different behavior: Daptonema fallax was eliminated in contaminated microcosms, suggesting that it is an intolerant species to phenanthrene; Neochromadora peocilosoma, Spirinia parasitifera, and Odontophora n. sp., which significantly (p < 0.05) increased in contaminated microcosms, could be considered as "opportunistic" species to phenanthrene whereas Anticoma acuminata and Calomicrolaimus honestus increased in the treatment combining biostimulation and bioaugmentation. Phenanthrene had a significant effect on meiofaunal and bacterial abundances (p < 0.05), with a strong reduction of density and change in the nematode communities

  10. Environmental Aging of Polycyclic Aromatic Hydrocarbons on Soot and its Effect on Source Identification

    PubMed Central

    Kim, Daekyun; Kumfer, Benjamin M.; Anastasio, Cort; Kennedy, Ian M.; Young, Thomas M.

    2009-01-01

    Soot associated PAHs were exposed to simulated sunlight to investigate disappearance rates under environmental aging conditions and to examine the robustness of diagnostic ratios for PAH source apportionment. Naphthalene, acenaphthylene, acenaphthene, and fluorene showed an obvious two-phase disappearance in all experiments while phenanthrene and anthracene exhibited this behavior for all but the highest soot loading. The first phase loss is 5-40 times faster than the second phase loss and occurred within 3 h for naphthalene, acenaphthylene, acenaphthene, and fluorene and within 10 h for phenanthrene and anthracene. Two-phase disappearance was not observed for any of the higher molecular weight PAHs with 4-6 rings. Each PAH has a unique loss rate via photodegradation and volatilization and these rates of some PAHs were affected by soot loadings; phenanthrene and anthracene showed similar rates in the first phase and increased loss rates in the second phase as soot loading increased. In the absence of light, the loss of PAHs was related to both temperature and molecular characteristics. Due to differences in disappearance rates of individual PAHs under illumination over extended times, prolonged exposure to sunlight could change the interpretation of some diagnostic ratios used previously for PAH source identification. This result indicates that more consistent and accurate methods that take into consideration the longevity of particulate PAHs are needed for reliable source apportionment. PMID:19443013

  11. Ultraviolet and visible spectra of the 1,3,5-trinitrobenzolates of polycyclic aromatic hydrocarbons and other organic compounds: A method for their identification (Part II)

    SciTech Connect

    Tombesi, O.L.; Frontera, M.A.; Tomas, M.A.; Badajoz, M.A. )

    1993-01-01

    In a previous paper, a study of ultraviolet and visible spectra of the picrates of polycyclic aromatic hydrocarbons and other representative organic compounds was reported. In the present paper, a similar study of 1,3,5-trinitrobenzolates derivatives is described. In the following discussion, the ultraviolet and visible spectra of the 1,3,5-trinitrobenzolates of polycyclic aromatic hydrocarbons [naphthalene (I), [beta]-methylnaphthalene (II), anthracene (III), phenanthrene (IV), chrysene (V), pyrene (VI), fluorene (VII), and acenaphthene (VIII)] and other representative organic compounds [dibenzofuran (IX), [beta]-naphthol (X), and [alpha]-naphthylamine (XI)] are given. 9 refs.

  12. Extractive biodegradation and bioavailability assessment of phenanthrene in the cloud point system by Sphingomonas polyaromaticivorans.

    PubMed

    Pan, Tao; Deng, Tao; Zeng, Xinying; Dong, Wei; Yu, Shuijing

    2016-01-01

    The biological treatment of polycyclic aromatic hydrocarbons is an important issue. Most microbes have limited practical applications because of the poor bioavailability of polycyclic aromatic hydrocarbons. In this study, the extractive biodegradation of phenanthrene by Sphingomonas polyaromaticivorans was conducted by introducing the cloud point system. The cloud point system is composed of a mixture of (40 g/L) Brij 30 and Tergitol TMN-3, which are nonionic surfactants, in equal proportions. After phenanthrene degradation, a higher wet cell weight and lower phenanthrene residue were obtained in the cloud point system than that in the control system. According to the results of high-performance liquid chromatography, the residual phenanthrene preferred to partition from the dilute phase into the coacervate phase. The concentration of residual phenanthrene in the dilute phase (below 0.001 mg/L) is lower than its solubility in water (1.18 mg/L) after extractive biodegradation. Therefore, dilute phase detoxification was achieved, thus indicating that the dilute phase could be discharged without causing phenanthrene pollution. Bioavailability was assessed by introducing the apparent logP in the cloud point system. Apparent logP decreased significantly, thus indicating that the bioavailability of phenanthrene increased remarkably in the system. This study provides a potential application of biological treatment in water and soil contaminated by phenanthrene.

  13. Evaluation of phenanthrene toxicity on earthworm (Eisenia fetida): an ecotoxicoproteomics approach.

    PubMed

    Wu, Shijin; Xu, Xian; Zhao, Shiliang; Shen, Feichao; Chen, Jianmeng

    2013-10-01

    The goal of this study was to identify promising new biomarkers of phenanthrene by identifying differentially expressed proteins in Eisenia fetida after exposure to phenanthrene. Extracts of earthworm epithelium collected at days 2, 7, 14, and 28 after phenanthrene exposure were analyzed by two dimensional electrophoresis (2-DE) and quantitative image analysis. Comparing the intensity of protein spots, 36 upregulated proteins and 45 downregulated proteins were found. Some of the downregulated and upregulated proteins were verified by MALDI-TOF/TOF-MS and database searching. Downregulated proteins in response to phenanthrene exposure were involved in glycolysis, energy metabolism, chaperones, proteolysis, protein folding and electron transport. In contrast, oxidation reduction, oxygen transport, defense systems response to pollutant, protein biosynthesis and fatty acid biosynthesis were upregulated in phenanthrene-treated E. fetida. In addition, ATP synthase b subunit, lysenin-related protein 2, lombricine kinase, glyceraldehyde 3-phosphate dehydrogenase, actinbinding protein, and extracellular globin-4 seem to be potential biomarkers since these biomarker were able to low levels (2.5 mg kg(-1)) of phenanthrene. Our study provides a functional profile of the phenanthrene-responsive proteins in earthworms. The variable levels and trends in these spots could play a potential role as novel biomarkers for monitoring the levels of phenanthrene contamination in soil ecosystems. PMID:23856470

  14. Physiological and molecular responses of springtails exposed to phenanthrene and drought.

    PubMed

    Holmstrup, Martin; Slotsbo, Stine; Schmidt, Stine N; Mayer, Philipp; Damgaard, Christian; Sørensen, Jesper G

    2014-01-01

    Interaction between effects of hazardous chemicals in the environment and adverse climatic conditions is a problem that receives increased attention in the light of climate change. We studied interactive effects of phenanthrene and drought using a test system in which springtails (Folsomia candida Willem) were concurrently exposed to a sublethal phenanthrene level via passive dosing from silicone (chemical activity of 0.010), and sublethal drought from aqueous NaCl solutions (water activity of 0.988). Previous studies have shown that the combined effects of high levels of phenanthrene and drought, respectively, interact synergistically when using lethality as an end-point. Here, we hypothesized that phenanthrene interferes with physiological mechanisms involved in drought tolerance, and that drought influences detoxification of phenanthrene. However, this hypothesis was not supported by data since phenanthrene had no effect on drought-protective accumulation of myo-inositol, and normal water conserving mechanisms of F. candida were functioning despite the near-lethal concentrations of the toxicant. Further, detoxifying induction of cytochrome P450 and glutathione-S-transferase was not impeded by drought. Both phenanthrene and drought induced transcription of heat shock protein (hsp70) and the combined effect of the two stressors on hsp70 transcription was additive, suggesting that the cellular stress and lethality imposed by these levels of phenanthrene and drought were also additive. PMID:24095812

  15. Simultaneous removal of phenanthrene and lead from artificially contaminated soils with glycine-β-cyclodextrin.

    PubMed

    Wang, Guanghui; Zhou, Yueming; Wang, Xuegang; Chai, Xinjun; Huang, Lei; Deng, Nansheng

    2010-12-15

    Preparation of glycine-β-cyclodextrin (GCD) was carried out by the reaction of β-cyclodextrin with glycine in the presence of KOH and epichlorohydrin. The enhanced solubilization behavior of phenanthrene and lead carbonate by GCD was studied, and the desorption behavior of phenanthrene and lead from co-contaminated soil was also investigated. The results showed that GCD has obvious solubilization for phenanthrene and lead carbonate. The solubility of phenanthrene in 30 g/L of GCD was enhanced about 30-fold. And the apparent aqueous solubilities of lead carbonate are also obviously increased with increasing GCD concentration, when the concentration of GCD reached 20 g/L, the aqueous lead concentration was 2945 mg/L. GCD could simultaneously increase the apparent aqueous solubility of phenanthrene and complex with lead. The desorption process of GCD for phenanthrene and lead from co-contaminated soil followed the pseudo-second-order kinetic model. The removal efficiencies of phenanthrene and lead in soil increased dramatically with increasing GCD concentrations. At concentration of 40 g/L, GCD has a removal efficiency of 85.8% and 78.8% for lead and phenanthrene, respectively, from the combined contaminated soil. The use of GCD as an extractant to enhance the removal of heavy and hydrophobic organic contaminants (HOCs) from co-contaminated soils appears as a promising remediation method.

  16. Evidence of polycyclic aromatic hydrocarbon biodegradation in a contaminated aquifer by combined application of in situ and laboratory microcosms using (13)C-labelled target compounds.

    PubMed

    Bahr, Arne; Fischer, Anko; Vogt, Carsten; Bombach, Petra

    2015-02-01

    The number of approaches to evaluate the biodegradation of polycyclic aromatic hydrocarbons (PAHs) within contaminated aquifers is limited. Here, we demonstrate the applicability of a novel method based on the combination of in situ and laboratory microcosms using (13)C-labelled PAHs as tracer compounds. The biodegradation of four PAHs (naphthalene, fluorene, phenanthrene, and acenaphthene) was investigated in an oxic aquifer at the site of a former gas plant. In situ biodegradation of naphthalene and fluorene was demonstrated using in situ microcosms (BACTRAP(®)s). BACTRAP(®)s amended with either [(13)C6]-naphthalene or [(13)C5/(13)C6]-fluorene (50:50) were incubated for a period of over two months in two groundwater wells located at the contaminant source and plume fringe, respectively. Amino acids extracted from BACTRAP(®)-grown cells showed significant (13)C-enrichments with (13)C-fractions of up to 30.4% for naphthalene and 3.8% for fluorene, thus providing evidence for the in situ biodegradation and assimilation of those PAHs at the field site. To quantify the mineralisation of PAHs, laboratory microcosms were set up with BACTRAP(®)-grown cells and groundwater. Naphthalene, fluorene, phenanthrene, or acenaphthene were added as (13)C-labelled substrates. (13)C-enrichment of the produced CO2 revealed mineralisation of between 5.9% and 19.7% for fluorene, between 11.1% and 35.1% for acenaphthene, between 14.2% and 33.1% for phenanthrene, and up to 37.0% for naphthalene over a period of 62 days. Observed PAH mineralisation rates ranged between 17 μg L(-1) d(-1) and 1639 μg L(-1) d(-1). The novel approach combining in situ and laboratory microcosms allowed a comprehensive evaluation of PAH biodegradation at the investigated field site, revealing the method's potential for the assessment of PAH degradation within contaminated aquifers.

  17. Effect of root exudates on sorption, desorption, and transport of phenanthrene in mangrove sediments.

    PubMed

    Jia, Hui; Lu, Haoliang; Dai, Minyue; Hong, Hualong; Liu, Jingchun; Yan, Chongling

    2016-08-15

    The effect of root exudates on the environmental behaviors of phenanthrene in mangrove sediments is poorly understood. In order to evaluate their influence, comprehensive laboratory experiments were performed using batch equilibrium and thin-layer chromatography (TLC) analyses. In the presence of root exudates, sorption of phenanthrene was inhibited, whereas desorption and mobility were promoted, and were elevated as root exudate concentrations increased. Among the three representative low molecular weight organic acids (LMWOAs) (citric, oxalic, and acetic acids), citric acid promoted desorption and mobility of phenanthrene more effectively than the other two. In addition, application of artificial root exudates (AREs) enhanced phenanthrene desorption, and mobility was always lower than that with the same concentration of LMWOAs, suggesting that LMWOAs predominantly affected the fate of phenanthrene in sediments. The results of this study could enhance our understanding of the mobility of persistent organic pollutants in sediment-water system.

  18. Effect of root exudates on sorption, desorption, and transport of phenanthrene in mangrove sediments.

    PubMed

    Jia, Hui; Lu, Haoliang; Dai, Minyue; Hong, Hualong; Liu, Jingchun; Yan, Chongling

    2016-08-15

    The effect of root exudates on the environmental behaviors of phenanthrene in mangrove sediments is poorly understood. In order to evaluate their influence, comprehensive laboratory experiments were performed using batch equilibrium and thin-layer chromatography (TLC) analyses. In the presence of root exudates, sorption of phenanthrene was inhibited, whereas desorption and mobility were promoted, and were elevated as root exudate concentrations increased. Among the three representative low molecular weight organic acids (LMWOAs) (citric, oxalic, and acetic acids), citric acid promoted desorption and mobility of phenanthrene more effectively than the other two. In addition, application of artificial root exudates (AREs) enhanced phenanthrene desorption, and mobility was always lower than that with the same concentration of LMWOAs, suggesting that LMWOAs predominantly affected the fate of phenanthrene in sediments. The results of this study could enhance our understanding of the mobility of persistent organic pollutants in sediment-water system. PMID:27293074

  19. Adsorption and bioaccessibility of phenanthrene on carbon nanotubes in the in vitro gastrointestinal system.

    PubMed

    Li, Wei; Zhao, Jian; Zhao, Qing; Zheng, Hao; Du, Peng; Tao, Shu; Xing, Baoshan

    2016-10-01

    Adsorption and bioaccessibility of phenanthrene on graphite and multiwalled carbon nanotubes (CNTs) were investigated in simulated gastrointestinal fluid using a passive dosing system. The saturated adsorption capacity of phenanthrene on different adsorbents follows an order of hydroxylated CNTs (H-CNTs)>carboxylated CNTs (C-CNTs)>graphitized CNTs (G-CNTs)>graphite, consistent with the order of their surface area and micropore volume. The change of phenanthrene adsorption on the adsorbents is different with the presence of pepsin (800mg/L) and bile salts (500mg/L and 5000mg/L, abbreviated as BS500 and BS5000). Both solubilization of phenanthrene by pepsin and bile salts and their competition with phenanthrene for the adsorption sites play a role. In addition, the large increase of the maximum adsorption capacity in BS5000 solution indicates an enhanced dispersion of CNTs or an exfoliation of graphite by bile salts, which consequently increases the exposed surface area. The bioaccessibility increases in pepsin and BS500 solution with a growing free phenanthrene concentration. Although the bioaccessibility of phenanthrene stalls or slightly decreases in the middle range of free phenanthrene concentration in BS5000 solution, the bioaccessibility overall is much higher than that in pepsin and BS500 solution at the same phenanthrene level. It is impossible to separate the effect of competition from dispersion (or exfoliation) at this stage, but the relative contribution of solubilization to phenanthrene desorption in pepsin and BS500 solutions was quantified, which improves our understanding of the mechanisms on bioaccessibility of adsorbed pollutants on CNTs. PMID:27213670

  20. 1-(Fluoren-2-yl)-2-(2-azafluoren-3-yl)ethene and 1-(fluoren-2-yl)-2-(2H,2-methylindeno(2,3-c)pyridine)ethene

    SciTech Connect

    Prostakov, N.S.; Obynochnyi, A.A.; Murugova, L.A.

    1987-11-01

    Condensation of 3-methyl-2-azafluorene with 2-formylfluorene results in the formation of a compound containing a polyconjugated system and two acidic CH centers, namely, 1-(fluoren-2-yl)-2-(2-azafluoren-3-yl)ethene. The conversions of this compound upon treatment with alkali have been studied by electronic absorption spectroscopy. The methyl iodide derivative of this base was used as an intermediate in the preparation of a pseudo-azulene, 1-(fluoren-2-yl)-2-(2H,2-methylindeno(2,3-c)pyridine)ethene.

  1. Biodegradation of phenanthrene and pyrene in compost-amended soil.

    PubMed

    Yuan, Shaw Y; Su, Lai M; Chang, Bea V

    2009-06-01

    This study investigated the biodegradation of the polycyclic aromatic hydrocarbons (PAHs) phenanthrene and pyrene in compost and compost-amended soil. The degradation rates of the two PAHs were phenanthrene>pyrene. The degradation of PAH was enhanced when the two PAHs were present simultaneously in the soil. The addition of either of the two types of compost (straw and animal manure) individually enhanced PAH degradation. Compost samples were separated into fractions with various particle size ranges, which spanned 2-50 microm, 50-105 microm, 105-500 microm, and 500-2000 microm. We observed that the compost fractions with smaller particle sizes demonstrated higher PAH degradation rates. However, when the different compost fractions were added to soil, compost particle size had no significant effect on the rate of PAH degradation. Of the micro-organisms isolated from the soil-compost mixtures, strains S1, S2, and S8, which were identified as Arthrobacter nicotianae, Pseudomonas fluorescens, and Bordetella Petrii, respectively, demonstrated the best degradation ability.

  2. Potassium permanganate oxidation of phenanthrene and pyrene in contaminated soils.

    PubMed

    de Souza e Silva, Paula Tereza; da Silva, Valdinete Lins; Neto, Benício de Barros; Simonnot, Marie-Odile

    2009-09-15

    Potassium permanganate, widely used in water treatment, has shown its applicability to reduce PAH contamination in groundwater and soils. The first stage to design a treatment at the site scale is the feasibility study at the bench scale, generally performed by means of batch experiments. The aim of the present contribution was to investigate the influence of two factors on PAH degradation in spiked soils, following the method of factorial designs. These factors were the weight ratio KMnO(4)/PAH and the reaction time. Three factorial designs were performed and batch experiments were run to study the degradation of phenanthrene and pyrene on soils spiked at different concentrations, between 700 and 2100 mg kg(-1). We showed that treatment with potassium permanganate significantly reduced PAH concentration, but pyrene was more recalcitrant than phenanthrene. Both variables had negative main effects and a positive two-factor interaction effect: increasing the weight ratio or the reaction time enhanced PAH degradation but the reduction produced by the two factors was lower than the sum of the individual contributions. The comparison of these results with results that we published previously under comparable conditions showed that Fenton's reagent was more efficient than potassium permanganate.

  3. Thermodynamics and existing phase of Ba-phenanthrene

    NASA Astrophysics Data System (ADS)

    Heguri, Satoshi; Thi Nhu Phan, Quynh; Tanabe, Yoichi; Tanigaki, Katsumi

    2015-03-01

    The recent discovery of superconductivity in potassium doped picene suggested the possibility of a new class of superconductors. The problem is that no satisfactory guide to improve the superconducting shielding fraction had been provided until recently. However, a high superconducting shielding fraction of 65 % was reported for Ba1.5(phenanthrene). Considering this situation, phenanthrene (PHN) appears to be a key material for confirming the existence of metallicity and superconductivity in the aromatic hydrocarbon (AHC) family, and also for clarifying the physical properties and superconducting mechanism of AHC superconductors. In the present work, the thermodynamics for intercalation of PHN with Ba is studied in comparison with its isomer of anthracene (AN). Contrarily to previous reports by other authors, the important observation that Ba is intercalated into neither PHN nor AN without affecting their molecular structures is unambiguously made by differential scanning calorimetry measurements and annealing time dependences observed by powder x-ray diffraction measurements. The reactions of Ba and PHN at elevated temperatures lead this system to molecular decomposition instead of intercalation. The phenomena of metallicity and superconductivity in PHN intercalated with alkaline earth metals (Ba or Sr) should be reconsidered.

  4. Degradation of phenanthrene and pyrene in spiked soils by single and combined plants cultivation.

    PubMed

    Cheema, Sardar Alam; Imran Khan, Muhammad; Shen, Chaofeng; Tang, Xianjin; Farooq, Muhammad; Chen, Lei; Zhang, Congkai; Chen, Yingxu

    2010-05-15

    The present study was conducted to investigate the capability of four plant species (tall fescue, ryegrass, alfalfa, and rape seed) grown alone and in combination to the degradation of phenanthrene and pyrene (polycyclic aromatic hydrocarbons, PAHs) in spiked soil. After 65 days of plant growth, plant biomass, dehydrogenase activity, water-soluble phenolic (WSP) compounds, plant uptake and accumulation and residual concentrations of phenanthrene and pyrene were determined. Our results showed that presence of vegetation significantly enhanced the dissipation of phenanthrene and pyrene from contaminated soils. Higher degradation rates of PAHs were observed in the combined plant cultivation (98.3-99.2% phenanthrene and 88.1-95.7% pyrene) compared to the single plant cultivation (97.0-98.0% phenanthrene and 79.8-86.0% pyrene). Contribution of direct plant uptake and accumulation of phenanthrene and pyrene was very low compared to the plant enhanced dissipation. By contrast, plant-promoted biodegradation was the predominant contribution to the remediation enhancement. The correlation analysis indicates a negative relation between biological activities (dehydrogenase activity and WSP compounds) and residual concentrations of phenanthrene and pyrene in planted soils. Our results suggest that phytoremediation could be a feasible choice for PAHs contaminated soil. Moreover, the combined plant cultivation has potential to enhance the process.

  5. Transport of dissolved organic macromolecules and their effect on the transport of phenanthrene in porous media

    SciTech Connect

    Magee, B.R.; Lion, L.W.; Lemley, A.T. )

    1991-02-01

    The retardation factor (R) of phenanthrene in a sand column was reduced by an average factor of 1.8 in the presence of dissolved organic matter (DOM) derived from soil, suggesting that a phenanthrene-DOM complex enhanced the transport of phenanthrene. Distribution coefficients (K{sub d}'s) were determined in batch and column studies for combinations of phenanthrene and DOM with sand. The retardation factor in the advective-dispersive transport equation was modified to reflect the pressure of a carrier by incorporating both the retardation and pore exclusion of the carrier itself. The best prediction of phenanthrene transport in the presence of DOM was provided by modeling the retardation by using two K{sub d}'s derived from column experiments of DOM alone and phenanthrene alone, along with the K{sub d} for phenanthrene binding to DOM. Sensitivity analyses indicated that the critical model parameters are the distribution coefficients for the hydrophobic pollutant binding to the stationary phase and binding to the carrier, as well as the carrier concentration.

  6. Oxidative stress and DNA damage responses to phenanthrene exposure in the estuarine guppy Poecilia vivipara.

    PubMed

    Machado, Anderson Abel de Souza; Hoff, Mariana Leivas Müller; Klein, Roberta Daniele; Cordeiro, Gilson Junior; Lencina Avila, Jannine Marquez; Costa, Patrícia Gomes; Bianchini, Adalto

    2014-07-01

    Despite ubiquitous phenanthrene contamination in aquatic coastal areas, little is known regarding its potential effects on estuarine fishes. The present work evaluated the response of a large suite of oxidative stress- and DNA damage-related biomarkers to phenanthrene exposure (10, 20 and 200 μg L(-1), 96 h) using DMSO as the solvent in estuarine guppy Poecilia vivipara (salinity 24 psu). Phenanthrene affected oxidative stress-related parameters, and decreased antioxidant defenses and reactive oxygen species in the gills and muscle overall. Lipid peroxidation occurred in muscle at 200 μg L(-1) phenanthrene. Genotoxicity was increased at 20 μg L(-1), while 200 μg L(-1) caused a relative decrease in erythrocyte release into the bloodstream. These findings indicated that phenanthrene is genotoxic and can induce oxidative stress, depending on tissue and phenanthrene concentration analyzed. Thus, some of the biomarkers analyzed in the present study are sufficiently sensitive to monitor the exposure of the guppy P. vivipara to phenanthrene in salt water. However, further studies are required for a better interpretation of the dose-response patterns observed.

  7. Visible light photodegradation of phenanthrene catalyzed by Fe(III)-smectite: role of soil organic matter.

    PubMed

    Jia, Hanzhong; Li, Li; Fan, Xiaoyun; Liu, Mingdeng; Deng, Wenye; Wang, Chuanyi

    2013-07-15

    In the present study, phenanthrene is employed as a model to explore the roles played by three soil organic matter (SOM) fractions, i.e., dissolved organic matter (DOM), humic acid (HA), and fulvic acid (FA), in its photodegradation with assistance of Fe(III)-smectite under visible-light. Slight decrease in phenanthrene photodegradation rate was observed in the presence of DOM, which is explained in terms of oxidative-radical competition between DOM and target phenanthrene molecules due to the high electron-donor capacity of phenolic moieties in DOM. On the other hand, a critic content is observed with FA (0.70mg/g) and HA (0.65mg/g). Before reaching the critic content, the removal of phenanthrene is accelerated; while after that, the photodegradation rate is suppressed. The acceleration of phenanthrene degradation can be attributed to the photosensitization of FA and HA. Due to the strong interaction between phenanthrene and the phenyl rings, however, the retention of phenanthrene on SOM-Fe(III)-smectite in the presence of high content of HA or FA is enhanced, thus slowing down its photodegradation. Those observations provide valuable insights into the transformation and fate of PAHs in the natural soil environment and open a window for using clay-humic substances complexes for remediation of contaminated soil.

  8. Genetic determinants involved in the biodegradation of naphthalene and phenanthrene in Pseudomonas aeruginosa PAO1.

    PubMed

    Qi, Jing; Wang, Bobo; Li, Jing; Ning, Huanhuan; Wang, Yingjuan; Kong, Weina; Shen, Lixin

    2015-05-01

    Pseudomonas sp. are predominant isolates of degradation-competent strains while very few studies have explored the degradation-related genes and pathways in most of the degrading strains. P. aeruginosa PAO1 was found capable of degrading naphthalene and phenanthrene efficiently. In order to investigate the degradation-related genes of naphthalene and phenanthrene in P. aeruginosa PAO1, a random promoter library of about 5760 strains was constructed. Thirty-two clones for differentially expressed promoters were obtained by screening in the presence of sub-inhibitory concentration of naphthalene and phenanthrene. Among them, 13 genes were up-regulated and 15 were down-regulated in the presence of naphthalene as well as phenanthrene. The four remaining genes have different regulation tendencies by naphthalene or phenanthrene. By comparing the growth between the wild type and mutants as well as the complementations, the roles of seven selected up-regulated genes on naphthalene and phenanthrene degradation were investigated. Five of the seven selected up-regulated genes, like PA2666 and PA4780, were found playing key roles on the degradation in P. aeruginosa PAO1. Also, the results imply that these genes participate in the overlapping part of naphthalene and phenanthrene degradation pathways in PAO1. Results in the article offer the convenience quick method and platform for searching degradation-related genes. It also laid a foundation for understanding of the role of the regulated genes.

  9. [Sorption and desorption of phenanthrene by organo-mineral complexes with different bridge cations].

    PubMed

    Ni, Jin-zhi; Luo, Yong-ming; Wei, Ran; Li, Xiu-hua; Qian, Wei

    2008-12-01

    Sorption and desorption of phenanthrene by organo-mineral complexes with Ca2+, Fe3+ and Al3+ as bridge cations were studied according to the association type between organic matter and minerals in natural soils. The results showed that the data of phenanthrene sorption and desorption by different cation saturated montmorillonite and their corresponding humic acid and mineral complexes could be fitted with Freundlich model, and the order of the sorption capacities (Kf) were Ca-Mont (0.184) > Fe-Mont (0.028) > Al-Mont (0.015) and Fe-Mont-HA (2.341) > Ca-Mont-HA (1.557) > Al-Mont-HA (1.136), respectively. The Kf values of humic acid and mineral complexes were far greater than those of minerals, which demonstrated that humic acid made great contributions to the sorption of phenanthrene in the organo-mineral complexes. However, the Kf values of the organo-mineral complexes with different bridge cations were not consistent with their organic carbon content, which indicated that both the organic carbon content and the combined types between organic matter and mineral could affect the sorption capacity of phenanthrene by the organo-mineral complexes. The desorption hysteresis of phenanthrene was significant for Ca2+ and Al3+ bridged organo-mineral complexes. Desorption hysteresis of phenanthrene was mainly from the sorption of phenanthrene by organic matter, and the contributions of mineral to the desorption hysteresis were not significant. PMID:19256397

  10. Low impact of phenanthrene dissipation on the bacterial community in grassland soil.

    PubMed

    Niepceron, Maïté; Beguet, Jérémie; Portet-Koltalo, Florence; Martin-Laurent, Fabrice; Quillet, Laurent; Bodilis, Josselin

    2014-02-01

    The effect of phenanthrene on the bacterial community was studied on permanent grassland soil historically presenting low contamination (i.e. less than 1 mg kg(-1)) by polycyclic aromatic hydrocarbons (PAHs). Microcosms of soil were spiked with phenanthrene at 300 mg kg(-1). After 30 days of incubation, the phenanthrene concentration decreased rapidly until its total dissipation within 90 days. During this incubation period, significant changes of the total bacterial community diversity were observed, as assessed by automated-ribosomal intergenic spacer analysis fingerprinting. In order to get a deeper view of the effect of phenanthrene on the bacterial community, the abundances of ten phyla and classes (Actinobacteria, Acidobacteria, Bacteroidetes, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Verrucomicrobiales, Gemmatimonadetes, and Planctomycetes) were monitored by quantitative polymerase chain reaction performed on soil DNA extracts. Interestingly, abundances of some bacterial taxa significantly changed as compared with controls. Moreover, among these bacterial groups impacted by phenanthrene spiking, some of them presented the potential of phenanthrene degradation, as assessed by PAH-ring hydroxylating dioxygenase (PAH-RHDα) gene detection. However, neither the abundance nor the diversity of the PAH-RHDα genes was significantly impacted by phenanthrene spiking, highlighting the low impact of this organic contaminant on the functional bacterial diversities in grassland soil.

  11. [Sorption and desorption of phenanthrene by organo-mineral complexes with different bridge cations].

    PubMed

    Ni, Jin-zhi; Luo, Yong-ming; Wei, Ran; Li, Xiu-hua; Qian, Wei

    2008-12-01

    Sorption and desorption of phenanthrene by organo-mineral complexes with Ca2+, Fe3+ and Al3+ as bridge cations were studied according to the association type between organic matter and minerals in natural soils. The results showed that the data of phenanthrene sorption and desorption by different cation saturated montmorillonite and their corresponding humic acid and mineral complexes could be fitted with Freundlich model, and the order of the sorption capacities (Kf) were Ca-Mont (0.184) > Fe-Mont (0.028) > Al-Mont (0.015) and Fe-Mont-HA (2.341) > Ca-Mont-HA (1.557) > Al-Mont-HA (1.136), respectively. The Kf values of humic acid and mineral complexes were far greater than those of minerals, which demonstrated that humic acid made great contributions to the sorption of phenanthrene in the organo-mineral complexes. However, the Kf values of the organo-mineral complexes with different bridge cations were not consistent with their organic carbon content, which indicated that both the organic carbon content and the combined types between organic matter and mineral could affect the sorption capacity of phenanthrene by the organo-mineral complexes. The desorption hysteresis of phenanthrene was significant for Ca2+ and Al3+ bridged organo-mineral complexes. Desorption hysteresis of phenanthrene was mainly from the sorption of phenanthrene by organic matter, and the contributions of mineral to the desorption hysteresis were not significant.

  12. Utilizing surfactants to control the sorption, desorption, and biodegradation of phenanthrene in soil-water system.

    PubMed

    Jin, Haiwei; Zhou, Wenjun; Zhu, Lizhong

    2013-07-01

    An integrative technology including the surfactant enhanced sorption and subsequent desorption and biodegradation of phenanthrene in the soil-water system was introduced and tested. For slightly contaminated agricultural soils, cationic-nonionic mixed surfactant-enhanced sorption of organic contaminants onto soils could reduce their transfer to plants, therefore safe-guarding agricultural production. After planting, residual surfactants combined with added nonionic surfactant could also promote the desorption and biodegradation of residual phenanthrene, thus providing a cost-effective pollution remediation technology. Our results showed that the cationic-nonionic mixed surfactants dodecylpyridinium bromide (DDPB) and Triton X-100 (TX100) significantly enhanced soil retention of phenanthrene. The maximum sorption coefficient Kd of phenanthrene for contaminated soils treated by mixed surfactants was about 24.5 times that of soils without surfactant (Kd) and higher than the combined effects of DDPB and TX100 individually, which was about 16.7 and 1.5 times Kd, respectively. On the other hand, TX100 could effectively remove phenanthrene from contaminated soils treated by mixed surfactants, improving the bioavailability of organic pollutants. The desorption rates of phenanthrene from these treated soils were greater than 85% with TX100 concentration above 2000 mg/L and approached 100% with increasing TX100 concentration. The biodegradation rates of phenanthrene in the presence of surfactants reached over 95% in 30 days. The mixed surfactants promoted the biodegradation of phenanthrene to some extent in 10-22 days, and had no obvious impact on phenanthrene biodegradation at the end of the experiment. Results obtained from this study provide some insight for the production of safe agricultural products and a remediation scheme for soils slightly contaminated with organic pollutants.

  13. Cysteine-β-cyclodextrin enhanced phytoremediation of soil co-contaminated with phenanthrene and lead.

    PubMed

    Wang, Guanghui; Wang, Yin; Hu, Suhang; Deng, Nansheng; Wu, Feng

    2015-07-01

    It is necessary to find an effective soil remediation technology for the simultaneous removal of hydrophobic organic contaminants and heavy metals from contaminated soils. In this work, a novel cysteine-β-cyclodextrin (CCD) was synthesized by the reaction of β-cyclodextrin with cysteine, and the structure of CCD was confirmed by (1)H-NMR, (13)C-NMR, FT-IR spectroscopy and elemental analysis. Pot-culture experiments were conducted to investigate the effects of CCD on the phytoremediation of soil co-contaminated with phenanthrene and lead. The results showed that CCD can enhance the phytoremediation of soil co-contaminated with phenanthrene and lead. When CCD was added to the co-contaminated soil, the concentrations of phenanthrene and Pb in roots and shoots of ryegrass (Lolium perenne L.) significantly increased, the presence of CCD is beneficial to the accumulation of phenanthrene and Pb in ryegrass, and the residual concentrations of phenanthrene and Pb in soils significantly decreased. Under the co-contamination of 500 mg Pb kg(-1) and 50 mg PHE kg(-1), the bioconcentration factor of phenanthrene and Pb in the presence of CCD was increased by 1.43-fold and 4.47-fold, respectively. After CCD was added to the contaminated soils, the residual concentration of phenanthrene and Pb in unplanted soil was decreased by 18 and 25%, respectively. However, for the planted soil, the residual concentration of phenanthrene and Pb was decreased by 48 and 56%, respectively. CCD may improve the bioavailability of phenanthrene and Pb in co-contaminated soil; CCD enhanced phytoremediation technology may be a good alternative for the removal of hydrophobic organic contaminants and heavy metals from contaminated soils.

  14. Naturally occurring phenanthrene degrading bacteria associated with seeds of various plant species.

    PubMed

    Fernet, Jennifer L; Lawrence, John R; Germida, James J

    2016-01-01

    Seeds of 11 of 19 plant species tested yielded naturally occurring phenanthrene degrading bacteria when placed on phenanthrene impression plates. Seed associated phenanthrene degrading bacteria were mostly detected on caragana, Canada thistle, creeping red fescue, western wheatgrass, and tall wheat grass. Based on 16S rRNA analysis the most common bacteria isolated from these seeds were strains belonging to the genera Enterobacteria, Erwinia, Burkholderia, Pantoea, Pseudomonas, and Sphingomonas. These plants may provide an excellent source of pre-adapted bacterial-plant associations highly suitable for use in remediation of contaminated soil environments.

  15. Naturally occurring phenanthrene degrading bacteria associated with seeds of various plant species.

    PubMed

    Fernet, Jennifer L; Lawrence, John R; Germida, James J

    2016-01-01

    Seeds of 11 of 19 plant species tested yielded naturally occurring phenanthrene degrading bacteria when placed on phenanthrene impression plates. Seed associated phenanthrene degrading bacteria were mostly detected on caragana, Canada thistle, creeping red fescue, western wheatgrass, and tall wheat grass. Based on 16S rRNA analysis the most common bacteria isolated from these seeds were strains belonging to the genera Enterobacteria, Erwinia, Burkholderia, Pantoea, Pseudomonas, and Sphingomonas. These plants may provide an excellent source of pre-adapted bacterial-plant associations highly suitable for use in remediation of contaminated soil environments. PMID:26515514

  16. Infrared Spectra of Perdeuterated Naphthalene, Phenanthrene, Chrysene, and Pyrene

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Sandford, Scott A.; Hudgins, Douglas M.; Arnold, James O. (Technical Monitor)

    1996-01-01

    Calculations are carried out using density functional theory (DFT) to determine the harmonic frequencies and intensities of perdeuterated naphthalene, phenanthrene, pyrene, and chrysene. We also report matrix- isolation spectra for these four species. The theoretical and experimental frequencies and relative intensities for the perdeuterated species are in generally good agreement. The effect of perdeuteration is to reduce the sum of the integrated intensities by a factor of about 1.75. This reduction occurs for all vibrational motions, except for the weak low frequency ring deformation modes. There is also a significant redistribution of the relative intensities between the out-of-plane C-D bands relative to those found for the out-of-plane C-H bands. The theoretical isotopic ratios provide an excellent diagnostic of the degree of C-H(C-D) involvement in the vibrational bands, allowing in most cases a clear distinction of the type of motion.

  17. Iron-Catalyzed Tandem Conia-Ene/Friedel-Crafts Reactions of o-Alkynyldihydrochalcones: Access to Benzo[b]fluorenes.

    PubMed

    Akbar, Sikkandarkani; Srinivasan, Kannupal

    2016-02-01

    o-Alkynyldihydrochalcones when treated with a catalytic amount of anhydrous FeCl3 in refluxing 1,2-dichloroethane underwent tandem Conia-ene and Friedel-Crafts reactions to yield benzo[b]fluorene derivatives in good yields. PMID:26726826

  18. Effect of n-alkyl chain length on the complexation of phenanthrene and 9-alkyl-phenanthrene with $beta;-cyclodextrin

    NASA Astrophysics Data System (ADS)

    Rima, J.; Aoun, E.; Hanna, K.

    2004-06-01

    The characteristics of host-guest complexation between β-cyclodextrin (β-CD) and phenanthrene derivatives (phenanthrene, n-propyl, n-butyl and n-hexyl-phenanthrene) were investigated by fluorescence spectrometry. Linear and non-linear regression methods were used to estimate the formation constants ( K1). A 1:1 stoichiometric ratio and an effect of n-alkyl chain length on the formation constant were observed for the binary inclusion complex between guest and β-CD. The formation constant dramatically increases with the length of n-alkyl, it starts from the value of 140 l mol -1 for the phenanthrene to reach the value of 580 l mol -1 for hexyl-phenanthrene. The effect of the temperature on the fluorescence intensity of each complex (guest-host) was also studied; and then the thermodynamic parameters were calculated. The main inclusion site seems to be aromatic moiety for short chain molecules, and it moves toward the alkyl chain part, as the chain becomes longer.

  19. Natural attenuation of fluorene and pyrene in contaminated soils and assisted with hydroxypropyl-β-cyclodextrin. Effect of co-contamination.

    PubMed

    Madrid, F; Rubio-Bellido, M; Villaverde, J; Tejada, M; Morillo, E

    2016-11-15

    The objectives of this study were to investigate the mutual effect of the PAHs fluorene and pyrene on their respective biodegradation and dissipation processes in an agricultural soil, and to determine the effect of hydroxypropyl-β-cyclodextrin (HPBCD), used to increase the bioavailability of PAHs, on such processes. Fluorene dissipation was primarily due to abiotic processes, although a small contribution from biodegradation was also observed. Therefore, fluorene dissipation did not increase with HPBCD and its presence did not significantly alter the dehydrogenase activity. In contrast to fluorene, pyrene dissipation depended primarily on biotic factors, with endogenous soil microorganisms capable of degrading pyrene, with large increases in dehydrogenase activity. HPBCD increased biodegradation rate of pyrene. The co-contamination of soil with both PAHs did not affect fluorene evolution, but significantly inhibited pyrene biodegradation. The different abilities of soil bacterial consortia to catabolize these PAHs are discussed. Additionally, the possibility that the abiotic loss of fluorene through volatilization had a significant effect on the microbial community biodegradation of both fluorene and pyrene is examined. PMID:27454573

  20. Natural attenuation of fluorene and pyrene in contaminated soils and assisted with hydroxypropyl-β-cyclodextrin. Effect of co-contamination.

    PubMed

    Madrid, F; Rubio-Bellido, M; Villaverde, J; Tejada, M; Morillo, E

    2016-11-15

    The objectives of this study were to investigate the mutual effect of the PAHs fluorene and pyrene on their respective biodegradation and dissipation processes in an agricultural soil, and to determine the effect of hydroxypropyl-β-cyclodextrin (HPBCD), used to increase the bioavailability of PAHs, on such processes. Fluorene dissipation was primarily due to abiotic processes, although a small contribution from biodegradation was also observed. Therefore, fluorene dissipation did not increase with HPBCD and its presence did not significantly alter the dehydrogenase activity. In contrast to fluorene, pyrene dissipation depended primarily on biotic factors, with endogenous soil microorganisms capable of degrading pyrene, with large increases in dehydrogenase activity. HPBCD increased biodegradation rate of pyrene. The co-contamination of soil with both PAHs did not affect fluorene evolution, but significantly inhibited pyrene biodegradation. The different abilities of soil bacterial consortia to catabolize these PAHs are discussed. Additionally, the possibility that the abiotic loss of fluorene through volatilization had a significant effect on the microbial community biodegradation of both fluorene and pyrene is examined.

  1. Heavy metal effects on the biodegradation of fluorene by Sphingobacterium sp. KM-02 isolated from PAHs-contaminated mine soil

    NASA Astrophysics Data System (ADS)

    Nam, I.; Chon, C.; Jung, K.; Kim, J.

    2012-12-01

    Polycyclic aromatic hydrocarbon compounds (PAHs) are widely distributed in the environment and occur ubiquitously in fossil fuels as well as in products of incomplete combustion and are known to be strongly toxic, often with carcinogenic and mutagenic properties. Fluorene is one of the 16 PAHs included in the list of priority pollutants of the Environmental Protection Agency. The fluorene-degrading bacterial strain Sphingobacterium sp. KM-02 was isolated from PAHs-contaminated soil near an abandoned mine impacted area by selective enrichment techniques. Fluorene added to the Sphingobacterium sp. KM-02 culture as sole carbon and energy source was 78.4% removed within 120 h. A fluorene degradation pathway is tentatively proposed based on mass spectrometric identification of the metabolic intermediates 9-fluorenone, 4-hydroxy-9-fluorenone, and 8-hydroxy-3,4-benzocoumarin. Further the ability of Sphingobacterium sp. KM-02 to bioremediate 100 mg/kg fluorene in mine soil was examined by composting under laboratory conditions. Treatment of microcosm soil with the strain KM-02 for 20 days resulted in a 65.6% reduction in total amounts. These results demonstrate that Sphingobacterium sp. KM-02 could potentially be used in the bioremediation of fluorene from contaminated soil. Mine impacted area comprises considerable amounts of heavy metals such as cadmium, lead, mercury, arsenic, and copper. Although some of these metals are necessary for biological life, excessive quantities often result in the inhibition of essential biological reactions via numerous pathways. A number of reports collectively show that various metals, such as Al, Co, Ni, Cu, Zn, Pb, and Hg at a range of concentrations have adverse effects on the degradation of organic compounds. However, at present there is only limited information on the effect of individual heavy metals on the biological degradation of polyaromatic hydrocarbons (PAHs) including fluorene. Moreover, heavy metal effects were not

  2. Effects of plant species identity, diversity and soil fertility on biodegradation of phenanthrene in soil.

    PubMed

    Oyelami, Ayodeji O; Okere, Uchechukwu V; Orwin, Kate H; De Deyn, Gerlinde B; Jones, Kevin C; Semple, Kirk T

    2013-02-01

    The work presented in this paper investigated the effects of plant species composition, species diversity and soil fertility on biodegradation of (14)C-phenanthrene in soil. The two soils used were of contrasting fertility, taken from long term unfertilised and fertilised grassland, showing differences in total nitrogen content (%N). Plant communities consisted of six different plant species: two grasses, two forbs, and two legume species, and ranged in species richness from 1 to 6. The degradation of (14)C-phenanthrene was evaluated by measuring indigenous catabolic activity following the addition of the contaminant to soil using respirometry. Soil fertility was a driving factor in all aspects of (14)C-phenanthrene degradation; lag phase, maximum rates and total extents of (14)C-phenanthrene mineralisation were higher in improved soils compared to unimproved soils. Plant identity had a significant effect on the lag phase and extents of mineralisation. Soil fertility was the major influence also on abundance of microbial communities.

  3. Hydrocracking phenanthrene and 1-methyl naphthalene: Development of linear free energy relationships

    SciTech Connect

    Landau, R.N.; Korre, S.C.; Neurock, M.; Klein, M.T.; Quann, R.J.

    1994-12-31

    The catalytic hydrocracking reaction pathways, kinetics and mechanisms of 1-methyl naphthalene and phenanthrene were investigated in experiments at 350 C and 68.1 atm H{sub 2} partial pressure (190.6 atm total pressure), using a presulfided Ni/W on USY zeolite catalyst. 1-methyl naphthalene hydrocracking led to 2-methyl naphthalene, methyl tetralins, methyl decalins, pentyl benzene and tetralin. Phenanthrene hydrocracking led to dihydro, tetrahydro and octahydro phenanthrene, butyl naphthalene, tetralin to butyl tetralin and dibutyl benzene. The rate constants for the dealkylation of butyl tetralins produced in the phenanthrene hydrocracking network conform to a linear free energy relationship (LFER), with the heat of formation of the leaving alkyl carbenium ion as the reactivity index.

  4. Sorption of phenanthrene and benzene on differently structural kerogen: important role of micropore-filling.

    PubMed

    Zhang, Yulong; Ma, Xiaoxuan; Ran, Yong

    2014-02-01

    Shale was thermally treated to obtain a series of kerogen with varied maturation. Their chemical, structural and porous properties were related to the sorption and/or desorption behaviors of phenanthrene and benzene. As the treatment temperature increases, aliphatic and carbonyl carbon of the kerogen samples decrease, while their aromaticity and maturation increase. Meanwhile, the isothermal nonlinearity of phenanthrene and benzene increases whereas the sorption capacity and micropore adsorption volumes (Vo,d) initially increase and then decrease. The Vo,d of benzene is significantly correlated with, but higher than that of phenanthrene, suggesting similar micropore filling mechanism and molecular sieve effect. The benzene desorption exhibits hysteresis, which is related to the pore deformation of the kerogen and the entrapment of solute in the kerogen matrix. The Vo,d of phenanthrene and benzene on the kerogen samples accounts for 23-46% and 36-65% of the maximum sorption volumes, respectively, displaying the importance of the micropore filling.

  5. Monitoring plant response to phenanthrene using the red edge of canopy hyperspectral reflectance.

    PubMed

    Zhu, Linhai; Chen, Zhongxin; Wang, Jianjian; Ding, Jinzhi; Yu, Yunjiang; Li, Junsheng; Xiao, Nengwen; Jiang, Lianhe; Zheng, Yuanrun; Rimmington, Glyn M

    2014-09-15

    To investigate the mechanisms and potential for the remote sensing of phenanthrene-induced vegetation stress, we measured field canopy spectra, and associated plant and soil parameters in the field controlled experiment in the Yellow River Delta of China. Two widely distributed plant communities, separately dominated by reed (Phragmites australis) and glaucous seepweed (Suaeda salsa), were treated with different doses of phenanthrene. The canopy spectral changes of plant community resulted from the decreases of biomass and foliar projective coverage, while leaf photosynthetic pigment concentrations showed no significance difference among treatments. The spectral response to phenanthrene included a flattened red edge, with decreased first derivative of reflectance. The red edge slope and area consistently responded to phenanthrene, showing a strong relationship with aboveground biomass, coverage and canopy pigments density. These results suggest the potential of remote sensing and the importance of field validation to correctly interpret the causes of the spectral changes. PMID:25038982

  6. Enhanced Solubilisation of Six PAHs by Three Synthetic Cyclodextrins for Remediation Applications: Molecular Modelling of the Inclusion Complexes

    PubMed Central

    Morillo, Esmeralda; Sánchez-Trujillo, María Antonia; Moyano, José Ramón; Villaverde, Jaime; Gómez-Pantoja, María Eulalia; Pérez-Martínez, José Ignacio

    2012-01-01

    Solubilisation of six polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, anthracene, fluoranthene, fluorene, phenanthrene and pyrene) by three synthetic cyclodextrins (CDs) (2-hydroxypropyl-β-CD, hydroxypropyl-γ-CD and ramdomly methylated-β-CD) was investigated in order to select the CD which presents the greatest increase in solubility and better complexation parameters for its use in contaminated scenarios. The presence of the three cyclodextrins greatly enhanced the apparent water solubility of all the PAHs through the formation of inclusion complexes of 1∶1 stoichiometry. Anthracene, fluoranthene, fluorene and phenanthrene clearly presented a higher solubility when β-CD derivatives were used, and especially the complexes with the ramdomly methylated-β-CD were favoured. On the contrary, pyrene presented its best solubility results when using 2-hydroxypropyl-γ-CD, but for acenaphthene the use of any of the three CDs gave the same results. Complementary to experimental phase-solubility studies, a more in-depth estimation of the inclusion process for the different complexes was carried out using molecular modelling in order to find a correlation between the degree of solubilisation and the fit of PAH molecules within the cavity of the different CDs and to know the predominant driving forces of the complexation. PMID:23028493

  7. Analysis of the organic contaminants in the condensate produced in the in situ underground coal gasification process.

    PubMed

    Smoliński, Adam; Stańczyk, Krzysztof; Kapusta, Krzysztof; Howaniec, Natalia

    2013-01-01

    Addressing the environmental risks related to contamination of groundwater with the phenolics, benzene, toluene, ethyl benzene, xylene (BTEX) and polycyclic aromatic hydrocarbons (PAHs), which might be potentially released from the underground coal gasification (UCG) under adverse hydrogeological and/or operational conditions, is crucial in terms of wider implementation of the process. The aim of this study was to determine the main organic pollutants present in the process condensate generated during the UCG trial performed on hard coal seam in the Experimental Mine 'Barbara', Poland; 8,933 L of condensate was produced in 813 h of experiment duration (including 456 h of the post-process stage) with average phenolics, BTEX and PAH concentrations of 576,000, 42.3 and 1,400.5 μg/L, respectively. The Hierarchical Clustering Analysis was used to explore the differences and similarities between the samples. The sample collected during the first 48 h of the process duration was characterized by the lowest phenanthrene, anthracene, fluoranthene and pyrene contents, high xylene content and the highest concentrations of phenolics, benzene, toluene and ethyl benzene. The samples collected during the stable operation of the UCG process were characterized by higher concentrations of naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, while in the samples acquired in the post-process stage the lowest concentrations of benzene, toluene, naphthalene, acenaphthene and fluorene were observed.

  8. Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.

    PubMed

    Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

    2011-02-01

    Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity. PMID:21072839

  9. Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.

    PubMed

    Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

    2011-02-01

    Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity.

  10. Enzymatic Mechanisms Involved in Phenanthrene Degradation by the White Rot Fungus Pleurotus ostreatus

    PubMed Central

    Bezalel, L.; Hadar, Y.; Cerniglia, C. E.

    1997-01-01

    The enzymatic mechanisms involved in the degradation of phenanthrene by the white rot fungus Pleurotus ostreatus were examined. Phase I metabolism (cytochrome P-450 monooxygenase and epoxide hydrolase) and phase II conjugation (glutathione S-transferase, aryl sulfotransferase, UDP-glucuronosyltransferase, and UDP-glucosyltransferase) enzyme activities were determined for mycelial extracts of P. ostreatus. Cytochrome P-450 was detected in both cytosolic and microsomal fractions at 0.16 and 0.38 nmol min(sup-1) mg of protein(sup1), respectively. Both fractions oxidized [9,10-(sup14)C]phenanthrene to phenanthrene trans-9,10-dihydrodiol. The cytochrome P-450 inhibitors 1-aminobenzotriazole (0.1 mM), SKF-525A (proadifen, 0.1 mM), and carbon monoxide inhibited the cytosolic and microsomal P-450s differently. Cytosolic and microsomal epoxide hydrolase activities, with phenanthrene 9,10-oxide as the substrate, were similar, with specific activities of 0.50 and 0.41 nmol min(sup-1) mg of protein(sup-1), respectively. The epoxide hydrolase inhibitor cyclohexene oxide (5 mM) significantly inhibited the formation of phenanthrene trans-9,10-dihydrodiol in both fractions. The phase II enzyme 1-chloro-2,4-dinitrobenzene glutathione S-transferase was detected in the cytosolic fraction (4.16 nmol min(sup-1) mg of protein(sup-1)), whereas aryl adenosine-3(prm1)-phosphate-5(prm1)-phosphosulfate sulfotransferase (aryl PAPS sulfotransferase) UDP-glucuronosyltransferase, and UDP-glucosyltransferase had microsomal activities of 2.14, 4.25, and 4.21 nmol min(sup-1) mg of protein(sup-1), respectively, with low activity in the cytosolic fraction. However, when P. ostreatus culture broth incubated with phenanthrene was screened for phase II metabolites, no sulfate, glutathione, glucoside, or glucuronide conjugates of phenanthrene metabolites were detected. These experiments indicate the involvement of cytochrome P-450 monooxygenase and epoxide hydrolase in the initial phase I oxidation of

  11. Effects of phenanthrene on the mortality, growth, and anti-oxidant system of earthworms (Eisenia fetida) under laboratory conditions.

    PubMed

    Wu, Shijin; Wu, Ermiao; Qiu, Lequan; Zhong, Weihong; Chen, Jianmeng

    2011-04-01

    To assess the toxic effects of phenanthrene on earthworms, we exposed Eisenia fetida to artificial soils supplemented with different concentrations (0.5, 2.5, 12.5, mgkg(-1) soil) of phenanthrene. The residual phenanthrene in the soil, the bioaccumulation of phenanthrene in earthworms, and the subsequent effects of phenanthrene on growth, anti-oxidant enzyme activities, and lipid peroxidation (LPO) were determined. The degradation rate of low concentrations of phenanthrene was faster than it was for higher concentrations, and the degradation half-life was 7.3d (0.5 mgkg(-1)). Bioaccumulation of phenanthrene in the earthworms decreased the phenanthrene concentration in soils, and phenanthrene content in the earthworms significantly increased with increasing initial soil concentrations. Phenanthrene had a significant effect on E. fetida growth, and the 14-d LC(50) was calculated as 40.67 mgkg(-1). Statistical analysis of the growth inhibition rate showed that the concentration and duration of exposure had significant effects on growth inhibition (p<0.001). Superoxide dismutase (SOD) activity increased at the beginning (2 and 7d) and decreased in the end (14 and 28 d). Catalase (CAT) activity in all treatments was inhibited from 1 to 14 d of exposure. However, no significant perturbations in malondialdehyde (MDA) content were noted between control and phenanthrene-treated earthworms except after 2d of exposure. These results revealed that bioaccumulation of phenanthrene in E. fetida caused concentration-dependent, sub-lethal toxicity. Growth and superoxide dismutase activity can be regarded as sensitive parameters for evaluating the toxicity of phenanthrene to earthworms.

  12. Surfaces wettability and morphology modulation in a fluorene derivative self-assembly system

    NASA Astrophysics Data System (ADS)

    Cao, Xinhua; Gao, Aiping; Zhao, Na; Yuan, Fangyuan; Liu, Chenxi; Li, Ruru

    2016-04-01

    A new organogelator based on fluorene derivative (gelator 1) was designed and synthesized. Organogels could be obtained via the self-assembly of the derivative in acetone, toluene, ethyl acetate, hexane, DMSO and petroleum ether. The self-assembly process was thoroughly characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV-vis, FT-IR and the contact angle. Surfaces with different morphologies and wetting properties were formed via the self-assembly of gelator 1 in the six different solvents. Interestingly, a superhydrophobic surface with a contact angle of 150° was obtained from organogel 1 in DMSO and exhibited the lotus-effect. The sliding angle necessary for a water droplet to move on the glass was only 15°. Hydrogen bonding and van der Waals forces were attributed as the main driving forces for gel formation.

  13. Amine-Reactive Fluorene Probes: Synthesis, Optical Characterization, Bioconjugation, and Two-Photon Fluorescence Imaging

    PubMed Central

    2008-01-01

    With the increasing demand for confocal and two-photon fluorescence imaging, the availability of reactive probes that possess high two-photon absorptivity, high fluorescence quantum yield, and high photostability is of paramount importance. To address the demand for better-performing probes, we prepared two-photon absorbing amine-reactive fluorenyl-based probes 2-(9,9-bis(2-(2-methoxyethoxy)ethyl)-2-isothiocyanato-9H-fluoren-7-yl)benzothiazole (1) and 2-(4-(2-(9,9-bis(2-(2-ethoxyethoxy)ethyl)-2-isothiocyanato-9H-fluoren-7-yl)vinyl)phenyl)benzothiazole (2), incorporating the isothiocyanate as a reactive linker. Probe design was augmented by integrating high optical nonlinearities, increased hydrophilicity, and coupling with reactive functional groups for specific targeting of biomolecules, assuring a better impact on two-photon fluorescence microscopy (2PFM) imaging. The isothiocyanate (NCS) derivatives were conjugated with cyclic peptide RGDfK and Reelin protein. The study of the chemical and photophysical properties of the new labeling reagents, as well as the conjugates, is described. The conjugates displayed high chemical stability and photostability. The NCS derivatives had low fluorescence quantum yields, while their bioconjugates exhibited high fluorescence quantum yields, essentially “lighting up” after conjugation. Conventional and 2PFM imaging and fluorescence lifetime imaging (FLIM) of HeLa, NT2, and H1299 cells, incubated with two-photon absorbing amine-reactive probe (1), RGDfK-dye conjugate (7), and Reelin-dye conjugate (6), was demonstrated. PMID:19090700

  14. A battery of bioassays for the evaluation of phenanthrene biotoxicity in soil.

    PubMed

    Khan, Muhammad Imran; Cheema, Sardar Alam; Tang, Xianjin; Hashmi, Muhammad Zaffar; Shen, Chaofeng; Park, Joonhong; Chen, Yingxu

    2013-07-01

    A battery of bioassays was used to assess the ecotoxicological risk of soil spiked with a range of phenanthrene levels (0.95, 6.29, 38.5, 58.7, 122, and 303 μg g(-1) dry soil) and aged for 69 days. Multiple species (viz. Brassica rapa, Eisenia feotida, Vibrio fischeri), representing different trophic levels, were used as bioindicator organisms. Among acute toxicity assays tested, the V. fischeri luminescence inhibition assay was the most sensitive indicator of phenanthrene biotoxicity. More than 15 % light inhibition was found at the lowest phenanthrene level (0.95 μg g(-1)). Furthermore, comet assay using E. fetida was applied to assess genotoxicity of phenanthrene. The strong correlation (r (2) ≥ 0.94) between phenanthrene concentration and DNA damage indicated that comet assay is appropriate for testing the genotoxic effects of phenanthrene-contaminated soil. In the light of these results, we conclude that the Microtox test and comet assay are robust and sensitive bioassays to be employed for the risk evaluation of polycyclic aromatic hydrocarbon-contaminated soil.

  15. [Screening of a phenanthrene-degrading bacterium and its degradation conditions].

    PubMed

    Zhou, Le; Sheng, Xiafang; Zhang, Shijin; Liu, Jing

    2005-12-01

    Several PAHs-degrading bacteria were isolated from the soil near a petrochemicals factory, and one strain Fl0a identified as B. sphaericus was chosen for use. The study on the phenanthrene-degradation potential of the strain and its affecting factors showed that at 28 degrees C, the degradation rate of phenanthrene (50 mg x L(-1)) was 98.12% after 27 hours rotary culture, and 98.47% after 84 hours static culture. F10a had a good phenanthrene-degradation capability when the pH was 4, 6 and 8, but its growth was inhibited when pH was 10. Cr2+ was toxic to the strain, Cu2+ could delay the degradation of phenanthrene, while Zn2+ and Pb2+ had no significant effects. The degradation rate of phenanthrene (200 mg x L(-1)) was 99.6% after 84 hours rotary culture. A significant positive relationship was found between bacterial growth and phenanthrene degradation. PMID:16515196

  16. Enhancing phenanthrene biomineralization in a polluted soil using gaseous toluene as a cosubstrate.

    PubMed

    Ortiz, Irmene; Auria, Richard; Sigoillot, Jean-Claude; Revah, Sergio

    2003-02-15

    Laboratory experiments were conducted to study the potential of adding gaseous toluene, as a readily degradable carbon source, to enhance phenanthrene mineralization in polluted soil (1,000 mg/kg(dry soil)) aged for 400 days. Experiments were conducted in 0.5-L column reactors packed with a mixture of (80:20 w(wet)/w(wet)) spiked soil and vermiculite and fed with 1 g m(-3)reactor h(-1) toluene load in air. Removal efficiencies of 100% for toluene and greater than 95% for phenanthrene were obtained in 190 h. Evolved CO2 showed that phenanthrene mineralization increased from 39% to 86% in columns treated with gaseous toluene. Phthalic acid was identified as the principal soluble intermediate, which accumulated when no toluene was added. Increased phenanthrene uptake and mineralization with toluene can be attributed to increased biomass and the induction of enzymes involved in the intermediate mineralization. In microcosm experiments, phthalic acid mineralization increased from 19% to 81% within 50 h in the presence of toluene. Experiments with 14C-labeled phenanthrene confirmed the enhancement of phenanthrene mineralization from 45% to 83% in 385 h with toluene as a second carbon source. The results indicate thatthe addition of an appropriate gaseous cosubstrate could be an adequate strategy to enhance mineralization of PAHs in soil. PMID:12636283

  17. Use of reporter-gene based bacteria to quantify phenanthrene biodegradation and toxicity in soil.

    PubMed

    Shin, Doyun; Moon, Hee Sun; Lin, Chu-Ching; Barkay, Tamar; Nam, Kyoungphile

    2011-02-01

    A phenanthrene-degrading bacterium, Sphingomonas paucimobilis EPA505 was used to construct two fluorescence-based reporter strains. Strain D harboring gfp gene was constructed to generate green fluorescence when the strain started to biodegrade phenanthrene. Strain S possessing gef gene was designed to die once phenanthrene biodegradation was initiated and thus to lose green fluorescence when visualized by a live/dead cell staining. Confocal laser scanning microscopic observation followed by image analysis demonstrates that the fluorescence intensity generated by strain D increased and the intensity by strain S decreased linearly at the phenanthrene concentration of up to 200 mg/L. Such quantitative increase and decrease of fluorescence intensity in strain D (i.e., from 1 to 11.90 ± 0.72) and strain S (from 1 to 0.40 ± 0.07) were also evident in the presence of Ottawa sand spiked with the phenanthrene up to 1000 mg/kg. The potential use of the reporter strains in quantitatively determining biodegradable or toxic phenanthrene was discussed.

  18. A battery of bioassays for the evaluation of phenanthrene biotoxicity in soil.

    PubMed

    Khan, Muhammad Imran; Cheema, Sardar Alam; Tang, Xianjin; Hashmi, Muhammad Zaffar; Shen, Chaofeng; Park, Joonhong; Chen, Yingxu

    2013-07-01

    A battery of bioassays was used to assess the ecotoxicological risk of soil spiked with a range of phenanthrene levels (0.95, 6.29, 38.5, 58.7, 122, and 303 μg g(-1) dry soil) and aged for 69 days. Multiple species (viz. Brassica rapa, Eisenia feotida, Vibrio fischeri), representing different trophic levels, were used as bioindicator organisms. Among acute toxicity assays tested, the V. fischeri luminescence inhibition assay was the most sensitive indicator of phenanthrene biotoxicity. More than 15 % light inhibition was found at the lowest phenanthrene level (0.95 μg g(-1)). Furthermore, comet assay using E. fetida was applied to assess genotoxicity of phenanthrene. The strong correlation (r (2) ≥ 0.94) between phenanthrene concentration and DNA damage indicated that comet assay is appropriate for testing the genotoxic effects of phenanthrene-contaminated soil. In the light of these results, we conclude that the Microtox test and comet assay are robust and sensitive bioassays to be employed for the risk evaluation of polycyclic aromatic hydrocarbon-contaminated soil. PMID:23440446

  19. Enhanced soil washing of phenanthrene by mixed solutions of TX100 and SDBS.

    PubMed

    Yang, Kun; Zhu, Lizhong; Xing, Baoshan

    2006-07-01

    Increased desorption of hydrophobic organic compounds (HOCs) from soils and sediments is a key to the remediation of contaminated soils and groundwater. In this study, phenanthrene desorption from a contaminated soil by mixed solutions of a nonionic surfactant(octylphenol polyethoxylate, TX100) and an anionic surfactant (sodium dodecylbenzenesulfonate, SDBS) was investigated. Phenanthrene desorption depended on not only aqueous surfactant concentrations and phenanthrene solubility enhancement but also the soil-sorbed surfactant amount and the corresponding sorption capacity of sorbed surfactants. The added surfactant critical desorption concentrations (CDCs) for phenanthrene from soil depended on both sorbed concentrations of surfactants and their critical micelle concentrations (CMCs). Phenanthrene desorption by mixed solutions was more efficient than individual surfactants due to the low sorption loss of mixed surfactants to soil. Among the tested surfactant systems, mixed TX100 and SDBS with a 1:9 mass ratio exhibited the highest phenanthrene desorption. Mixed micelle formation, showing negative deviation of CMCs from the ones predicted by the ideal mixing theory, was primarily responsible for the significant reduction of soil-sorbed amounts of TX100 and SDBS in their mixed systems. Therefore, mixed anionic-nonionic surfactants had great potential in the area of enhanced soil and groundwater remediation.

  20. Cyclopenta[c]phenanthrenes--chemistry and biological activity.

    PubMed

    Brzuzan, Paweł; Góra, Maciej; Luczyński, Michał K; Woźny, Maciej

    2013-06-25

    Despite cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs) having been detected in the environment, the ability of these compounds to induce cellular and tissue responses remains poorly characterized. In this review, we look at the chemistry and biological activity of the cyclopenta[c]phenanthrenes (CP[c]Phs) as potential chemicals of concern in the process of risk assessment. The first part of the review deals with the environmental occurrence and chemistry of CP-PAHs, focusing on available methods of CP[c]Ph chemical synthesis. The most interesting structural feature of the CP[c]Ph is the presence of a pseudo fjord-region constructed by the cyclopentane ring. This compound can be treated either as a structurally similar one to B[c]Ph, or as a phenanthrene skeleton with an electrodonating alkyl substituent in the bay-region of the molecule. The second thread, providing available data on the adverse effects of CP[c]Ph compounds on cells and tissues of living organisms, mainly fish, improves our understanding of these possible environmental hazards. The data show that CP[c]Ph is less potent at inducing CYP1A gene expression in rainbow trout than benzo[a]pyrene (B[a]P), a well-known Ah-receptor agonist. Interestingly, the CP[c]Ph dependent up-regulation of CYP1A mRNA is positively correlated with the incidences of clastogenic changes in rainbow trout erythrocytes. CP[c]Ph has, comparably to B[a]P, a potential to repress expression of tumor suppressor p53, in the head kidney of rainbow trout. Furthermore, estrogen responsive genes in fish liver, ERα and VTG, are not induced by CP[c]Ph, suggesting that the compound has no endocrine disrupting potential. However, some CP[c]Phs show mutagenic activity when investigated in the Ames test, and exhibit genotoxic properties in in vitro micronucleus assay. The above characteristics suggest that CP-PAHs are chemicals of concern for which potential pathways of exposure should be further identified. PMID:23628509

  1. 'Rare biosphere' bacteria as key phenanthrene degraders in coastal seawaters.

    PubMed

    Sauret, Caroline; Séverin, Tatiana; Vétion, Gilles; Guigue, Catherine; Goutx, Madeleine; Pujo-Pay, Mireille; Conan, Pascal; Fagervold, Sonja K; Ghiglione, Jean-François

    2014-11-01

    By coupling DNA-SIP and pyrosequencing approaches, we identified Cycloclasticus sp. as a keystone degrader of polycyclic aromatic hydrocarbons (PAH) despite being a member of the 'rare biosphere' in NW Mediterranean seawaters. We discovered novel PAH-degrading bacteria (Oceanibaculum sp., Sneathiella sp.) and we identified other groups already known to possess this function (Alteromonas sp., Paracoccus sp.). Together with Cycloclasticus sp., these groups contributed to potential in situ phenanthrene degradation at a rate >0.5 mg l(-1) day(-1), sufficient to account for a considerable part of PAH degradation. Further, we characterized the PAH-tolerant bacterial communities, which were much more diverse in the polluted site by comparison to unpolluted marine references. PAH-tolerant bacteria were also members of the rare biosphere, such as Glaciecola sp. Collectively, these data show the complex interactions between PAH-degraders and PAH-tolerant bacteria and provide new insights for the understanding of the functional ecology of marine bacteria in polluted waters.

  2. Polyurethane foam (PUF) passive samplers for monitoring phenanthrene in stormwater.

    PubMed

    Dou, Yueqin; Zhang, Tian C; Zeng, Jing; Stansbury, John; Moussavi, Massoum; Richter-Egger, Dana L; Klein, Mitchell R

    2016-04-01

    Pollution from highway stormwater runoff has been an increasing area of concern. Many structural Best Management Practices (BMPs) have been implemented for stormwater treatment and management. One challenge for these BMPs is to sample stormwater and monitor BMP performance. The main objective of this study was to evaluate the feasibility of using polyurethane foam (PUF) passive samplers (PSs) for sampling phenanthrene (PHE) in highway stormwater runoff and BMPs. Tests were conducted using batch reactors, glass-tube columns, and laboratory-scale BMPs (bioretention cells). Results indicate that sorption for PHE by PUF is mainly linearly relative to time, and the high sorption capacity allows the PUF passive sampler to monitor stormwater events for months or years. The PUF passive samplers could be embedded in BMPs for monitoring influent and effluent PHE concentrations. Models developed to link the results of batch and column tests proved to be useful for determining removal or sorption parameters and performance of the PUF-PSs. The predicted removal efficiencies of BMPs were close to the real values obtained from the control columns with errors ranging between -8.46 and 1.52%. This research showed that it is possible to use PUF passive samplers for sampling stormwater and monitoring the performance of stormwater BMPs, which warrants the field-scale feasibility studies in the future. PMID:26942631

  3. Polyurethane foam (PUF) passive samplers for monitoring phenanthrene in stormwater.

    PubMed

    Dou, Yueqin; Zhang, Tian C; Zeng, Jing; Stansbury, John; Moussavi, Massoum; Richter-Egger, Dana L; Klein, Mitchell R

    2016-04-01

    Pollution from highway stormwater runoff has been an increasing area of concern. Many structural Best Management Practices (BMPs) have been implemented for stormwater treatment and management. One challenge for these BMPs is to sample stormwater and monitor BMP performance. The main objective of this study was to evaluate the feasibility of using polyurethane foam (PUF) passive samplers (PSs) for sampling phenanthrene (PHE) in highway stormwater runoff and BMPs. Tests were conducted using batch reactors, glass-tube columns, and laboratory-scale BMPs (bioretention cells). Results indicate that sorption for PHE by PUF is mainly linearly relative to time, and the high sorption capacity allows the PUF passive sampler to monitor stormwater events for months or years. The PUF passive samplers could be embedded in BMPs for monitoring influent and effluent PHE concentrations. Models developed to link the results of batch and column tests proved to be useful for determining removal or sorption parameters and performance of the PUF-PSs. The predicted removal efficiencies of BMPs were close to the real values obtained from the control columns with errors ranging between -8.46 and 1.52%. This research showed that it is possible to use PUF passive samplers for sampling stormwater and monitoring the performance of stormwater BMPs, which warrants the field-scale feasibility studies in the future.

  4. Sublethal effects of phenanthrene, nicotine, and pinane on Daphnia pulex

    USGS Publications Warehouse

    Savino, Jacqueline F.; Tanabe, Lila L.

    1989-01-01

    Chronic studies of Daphnia Pulex exposed to different concentrations of phenanthrene, nicotine, and pinane produced consistent sublethal effects among replicates and concentrations. The LOEC's for growth and fecundity with each chemical tested were 3 to 30% of the 48-hr EC50's. Growth decreased as concentration increased for each chemical tested, and fecundity approached zero at 2 to 5 times the LOEC for each chemical. In this study chemicals representing PAHs, heterocyclic nitrogen compounds, and cyclic alkanes, produced detectable sublethal effects in daphnids at less than 0.1 ppm in water. These chronic studies, in conjuction with the more extensive acute toxicity testing (Passino and Smith 1987; Perry and Smith 1988; Smith et al. 1988), provided a relatively quick but thorough toxicological assessment of a large array of chemicals and demonstrated the relative importance of different classes of compounds in changing growth and survival trends in given populations of native organisms. Classic toxicity tests continue to provide a reliable backdrop of results with which the effects of new chemicals or mixtures can be compared.

  5. Comparison of phenanthrene and pyrene degradation by different wood-decaying fungi.

    PubMed Central

    Sack, U; Heinze, T M; Deck, J; Cerniglia, C E; Martens, R; Zadrazil, F; Fritsche, W

    1997-01-01

    The degradation of phenanthrene and pyrene was investigated by using five different wood-decaying fungi. After 63 days of incubation in liquid culture, 13.8 and 4.3% of the [ring U-14C]phenantherene and 2.4 and 1.4% of the [4,5,9,10-14C]pyrene were mineralized by Trametes versicolor and Kuehneromyces mutabilis, respectively. No 14CO2 evolution was detected in either [14C]phenanthrene or [14C]pyrene liquid cultures of Flammulina velutipes, Laetiporus sulphureus, and Agrocybe aegerita. Cultivation in straw cultures demonstrated that, in addition to T. versicolor (15.5%) and K. mutabilis (5.0%), L. sulphureus (10.7%) and A. aegerita (3.7%) were also capable of mineralizing phenanthrene in a period of 63 days. Additionally, K. mutabilis (6.7%), L. sulphureus (4.3%), and A. aegerita (3.3%) mineralized [14C]pyrene in straw cultures. The highest mineralization of [14C] pyrene was detected in straw cultures of T. versicolor (34.1%), which suggested that mineralization of both compounds by fungi may be independent of the number of aromatic rings. Phenanthrene and pyrene metabolites were purified by high-performance liquid chromatography and identified by UV absorption, mass, and 1H nuclear magnetic resonance spectrometry. Fungi capable of mineralizing phenanthrene and pyrene in liquid culture produced enriched metabolites substituted in the K region (C-9,10 position of phenanthrene and C-4,5 position of pyrene), whereas all other fungi investigated produced metabolites substituted in the C-1,2, C-3,4, and C-9,10 positions of phenanthrene and the C-1 position of pyrene. PMID:9327556

  6. A QTAIM and stress tensor investigation of the torsion path of a light-driven fluorene molecular rotary motor.

    PubMed

    Hu, Ming Xing; Xu, Tianlv; Momen, Roya; Huan, Guo; Kirk, Steven R; Jenkins, Samantha; Filatov, Michael

    2016-11-01

    The utility of the QTAIM/stress tensor analysis method for characterizing the photoisomerization of light driven molecular rotary machines is investigated on the example of the torsion path in fluorene molecular motor. The scalar and vector descriptors of QTAIM/stress tensor reveal additional information on the bonding interactions between the rotating units of the motor, which cannot be obtained from the analysis of the ground and excited state potential energy surfaces. The topological features of the fluorene motor molecular graph display that, upon the photoexcitation a certain increase in the torsional stiffness of the rotating bond can be attributed to the increasing topological stability of the rotor carbon atom attached to the rotation axle. The established variations in the torsional stiffness of the rotating bond may cause transfer of certain fraction of the torsional energy to other internal degrees of freedom, such as the pyramidalization distortion. © 2016 Wiley Periodicals, Inc. PMID:27671359

  7. Products of the OH radical-initiated gas-phase reaction of fluorene in the presence of NO x

    NASA Astrophysics Data System (ADS)

    Helmig, Detlev; Arey, Janet; Atkinson, Roger; Harger, William P.; McElroy, Patricia A.

    The products of the OH radical-initiated gas-phase reaction of fluorene in the presence of NO x were investigated in a 6400 ℓ all-Teflon chamber. Teh reaction products identified were fluorenone, 1-, 2-, 3- 4-nitrofluorene, three hydroxyfluorene isomers, three nitrofluorenone isomers and three hydroxynitrofluorene isomers. Of the reaction products identified, fluorenone was formed in the highest yield (9 ± 5%). The formation yields of the individual nitrofluorenes were in the order 3-nitrofluorene > 1- nitrofluorene > 4-nitrofluorene > 2-nitrofluorene, with the average 3-nitrofluorene yield being 1.4% and the total nitrofluorene yield being 2.5%. Diesel soot and ambient particulate matter showed relatively low concentrations of total nitrofluorenes when compared with the other nitro-PAH present. The measured ambient atmospheric concentrations of the nitrofluorenes were compared with levels expected on the basis of the nitrofluorene product yields from the OH radical-initiated reaction of fluorene.

  8. Electron-intramolecular-vibration interactions in positively charged phenanthrene-edge-type hydrocarbons

    NASA Astrophysics Data System (ADS)

    Kato, Takashi; Yamabe, Tokio

    2004-02-01

    Electron-phonon interactions in positively charged phenanthrene-edge-type hydrocarbons such as phenanthrene, chrysene, and picene are studied. The C-C stretching modes around 1500 cm-1 and the low-frequency modes around 500 cm-1 strongly couple to the highest occupied molecular orbitals (HOMO) in phenanthrene-edge-type hydrocarbons. The total electron-phonon coupling constants for the monocations (lHOMO) of 0.251, 0.135, and 0.149 eV for phenanthrene, chrysene, and picene, respectively, are estimated to be larger than those of 0.130, 0.107, and 0.094 eV for anthracene, tetracene, and pentacene, respectively. The phase patterns difference between the HOMO localized on carbon atoms which are located at the molecular edge in acene-edge-type hydrocarbons and the delocalized HOMO in phenanthrene-edge-type hydrocarbons is the main reason for the result. Strengths of orbital interactions between two neighboring carbon atoms in the HOMO become weaker with an increase in molecular size because the electron density on each carbon atom in the HOMO becomes smaller with an increase in molecular size in phenanthrene-edge-type hydrocarbons. On the other hand, the frontier orbitals of acene-edge-type hydrocarbons have somewhat nonbonding characters and thus cannot strongly couple to the totally symmetric vibrational modes compared with the frontier orbitals of phenanthrene-edge-type hydrocarbons. This is the reason why the lHOMO value for phenanthrene-edge-type hydrocarbons decreases with an increase in molecular size more significantly than that for acene-edge-type hydrocarbons, and the reason why the lHOMO value for polyphenanthrene with C2v geometry (0.033 eV) is estimated to be similar to that for polyacene (0.036 eV). The reorganization energies between the neutral molecules and the corresponding monocations for phenanthrene-edge-type hydrocarbons with large molecular size are estimated to be larger than those for acene-edge-type hydrocarbons with large molecular size.

  9. Effects of biosurfactant-producing bacteria on biodegradation and transport of phenanthrene in subsurface soil.

    PubMed

    Chang, Jae-Soo; Cha, Daniel K; Radosevich, Mark; Jin, Yan

    2015-01-01

    This study investigated the effects of surfactant-producing microorganism, Pseudomonas aeruginosa ATCC 9027, on phenanthrene (PHE) biodegradation by two different PHE-degrading bacteria (Isolate P5-2 and Pseudomonas strain R) in soil. Phenanthrene mineralization experiments were conducted with soils inoculated with one of PHE-degraders and/or the surfactant-producer. Influence of co-inoculation with the surfactant-producing bacteria on phenanthrene transport and biodegradation was also examined in soil columns. P. strain R mineralized phenanthrene faster and to a greater extent than Isolate P5-2 in the test soil. Co-inoculation with the surfactant-producing bacteria significantly enhanced phenanthrene biodegradation by P. strain R but it did not affect the biodegradation by Isolate P5-2 in both batch and column systems. Production of biosurfactants by P. aeruginosa ATCC 9027 was negligible under the given conditions. This study demonstrated that bioaugmentation with surfactant-producing bacteria could enhance in situ bioremediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs) and the beneficial effect of the bioaugmentation depended on types of PAH-degrading microorganisms present.

  10. Effect of amphiphilic polyurethane nanoparticles on sorption-desorption of phenanthrene in aquifer material.

    PubMed

    Kim, Ju-Young; Shim, Sun-Bo; Shim, Jin-Kie

    2003-03-17

    Micelle-like amphiphilic nano-sized polyurethane (APU) nanoparticles were synthesized via chemical cross-linking reaction of nano-aggregates of urethane acrylate nonionomer (UAN) chain and were tested for extraction efficiency of sorbed phenanthrene from aquifer material. Even though the solubilizing performance and interfacial activity of APU nanoparticles were inferior to that of Triton X-100, in the low concentration region, APU nanoparticles could effectively reduce phenanthrene sorption on the aquifer material and extracted sorbed phenanthrene from the aquifer material, whereas Triton X-100 could not extract sorbed phenanthrene and rather increased phenanthrene sorption onto the aquifer materials. At higher concentrations, APU nanoparticles and Triton X-100 had almost the same soil washing effectiveness. This interesting result is mainly due to a lower degree of sorption of APU nanoparticles onto the aquifer material. The sorption of APU nanoparticles onto aquifer sand is largely hindered by their chemically cross-linked nature, resulting in better soil-washing performance of APU nanoparticles than Triton X-100.

  11. Enhanced desorption of phenanthrene from contaminated soil using anionic/nonionic mixed surfactant.

    PubMed

    Zhou, Wenjun; Zhu, Lizhong

    2007-05-01

    A new approach using an anionic/nonionic mixed surfactant, sodium dodecyl sulphate (SDS) with Triton X-100 (TX100), was utilized for the desorption of phenanthrene from an artificial contaminated natural soil in an aim to improve the efficiency of surfactant remediation technology. The experimental results showed that the presence of SDS not only reduced the sorption of TX100 onto the natural soil, but also enhanced the solubilization of TX100 for phenanthrene, both of which resulted in the distribution of phenanthrene in soil-water systems decreasing with increasing mole fraction of SDS in surfactant solutions. These results can be attributed to the formation of mixed micelles in surfactant solution and the corresponding decrease in the critical micelle concentration of TX100 in mixed solution. The batch desorption experiments showed that the desorption percentage of phenanthrene from the contaminated soil with mixed solution was greater than that with single TX100 solution and appeared to be positively related to the mole fraction of SDS in surfactant solution. Thus, the anionic/nonionic mixed surfactants are more effective for the desorption of phenanthrene from the contaminated soil than a single nonionic surfactant.

  12. Ethanol and phenanthrene increase the biomass of fungal assemblages and decrease plant litter decomposition in streams.

    PubMed

    Barros, Diana; Oliveira, Patrícia; Pascoal, Cláudia; Cássio, Fernanda

    2016-09-15

    Fungi, particularly aquatic hyphomycetes, have been recognized as playing a dominant role in microbial decomposition of plant litter in streams. In this study, we used a microcosm experiment with different levels of fungal diversity (species number and identity) using monocultures and combinations with up to five aquatic hyphomycete species (Articulospora tetracladia, Tricladium splendens, Heliscus submersus, Tetrachaetum elegans and Flagellospora curta) to assess the effects of ethanol and phenanthrene on three functional measures: plant litter decomposition, fungal biomass accrual and reproduction. Alder leaves were conditioned by fungi for 7days and then were exposed to phenanthrene (1mgL(-1)) dissolved in ethanol (0.1% final concentration) or ethanol (at the concentration used to solubilise phenanthrene) for further 24days. Exposure to ethanol alone or in combination with phenanthrene decreased leaf decomposition and fungal reproduction, but increased fungal biomass produced. All aspects of fungal activity varied with species number. Fungal activity in polycultures was generally higher than that expected from the sum of the weighted performances of participating species in monoculture, suggesting complementarity between species. However, the activity of fungi in polycultures did not exceed the activity of the most productive species either in the absence or presence of ethanol alone or with phenanthrene.

  13. The impact of biochar on the bioaccessibility of (14)C-phenanthrene in aged soil.

    PubMed

    Ogbonnaya, O U; Adebisi, O O; Semple, K T

    2014-11-01

    Biochar is a carbon rich product from the incomplete combustion of biomass and it has been shown to reduce bioavailability of organic contaminants through adsorption. This study investigated the influence of 0%, 1%, 5% and 10% of two different particle sized wood biochars (≤2 mm and 3-7 mm) on the bioaccessibility of (14)C-phenanthrene (10 mg kg(-1)) in aged soil. The extent of (14)C-phenanthrene mineralisation by phenanthrene-degrading Pseudomonas sp. inoculum was monitored over a 14 day period in respirometric assays and compared to hydroxypropyl-β-cyclodextrin (HPCD) aqueous extraction. Notably, biochar amendments showed significant reduction in extents of mineralisation and HPCD extraction. Linear correlations between HPCD extractability and the total amount mineralised revealed good correlations, with 2 mm biochar showing a best fit (r(2) = 0.97, slope = 1.11, intercept = 1.72). Biochar reduced HPCD extractability and bioaccessibility of (14)C-phenanthrene to microorganisms in a similar manner. Biochar can aid risk reduction to phenanthrene exposure to biota in soil and HPCD can serve as a useful tool to assess the extent of exposure in biochar-amended soils.

  14. Ethanol and phenanthrene increase the biomass of fungal assemblages and decrease plant litter decomposition in streams.

    PubMed

    Barros, Diana; Oliveira, Patrícia; Pascoal, Cláudia; Cássio, Fernanda

    2016-09-15

    Fungi, particularly aquatic hyphomycetes, have been recognized as playing a dominant role in microbial decomposition of plant litter in streams. In this study, we used a microcosm experiment with different levels of fungal diversity (species number and identity) using monocultures and combinations with up to five aquatic hyphomycete species (Articulospora tetracladia, Tricladium splendens, Heliscus submersus, Tetrachaetum elegans and Flagellospora curta) to assess the effects of ethanol and phenanthrene on three functional measures: plant litter decomposition, fungal biomass accrual and reproduction. Alder leaves were conditioned by fungi for 7days and then were exposed to phenanthrene (1mgL(-1)) dissolved in ethanol (0.1% final concentration) or ethanol (at the concentration used to solubilise phenanthrene) for further 24days. Exposure to ethanol alone or in combination with phenanthrene decreased leaf decomposition and fungal reproduction, but increased fungal biomass produced. All aspects of fungal activity varied with species number. Fungal activity in polycultures was generally higher than that expected from the sum of the weighted performances of participating species in monoculture, suggesting complementarity between species. However, the activity of fungi in polycultures did not exceed the activity of the most productive species either in the absence or presence of ethanol alone or with phenanthrene. PMID:27186876

  15. Nitrite-induced enhancement of toxicity of phenanthrene in fish and its implications for coastal waters

    NASA Astrophysics Data System (ADS)

    Shailaja, M. S.; Rodrigues, A.

    2003-04-01

    Coastal areas are prone to varying degrees of anthropogenic chemical contamination. In many coastal environments experiencing reducing conditions in the water column, nitrite is produced as a result of denitrification. With a view to determining the effect of a natural stress such as the presence of nitrite in water on the xenobiotic metabolism in fish, the euryhaline cichlid Oreochromis mossambicus was exposed for up to 9 days to environmentally relevant concentrations of water-borne nitrite and phenanthrene, a polycyclic aromatic hydrocarbon. Analyses of different biomarkers in the treated fish indicated significant increase in the metabolism of phenanthrene as a result of exposure to nitrite. For example, the activity of the biotransformation enzyme measured as 7-ethoxyresorufin- O-deethylase activity was, in the presence of 1 μM nitrite, nearly twice that produced by phenanthrene alone. Similarly, biliary fixed fluorescence values reflecting phenanthrene and its metabolites were rendered 1.7 times higher when exposed simultaneously to nitrite. Contact with nitrite and phenanthrene together also led to severe hepatic damage with possible cell death as inferred from the large enhancement in sorbitol dehydrogenase activity in the serum and reduced liver somatic index.

  16. Impact of mycelia on the accessibility of fluorene to PAH-degrading bacteria.

    PubMed

    Schamfuß, Susan; Neu, Thomas R; van der Meer, Jan Roelof; Tecon, Robin; Harms, Hauke; Wick, Lukas Y

    2013-07-01

    Mycelia have been recently shown to actively transport polycyclic aromatic hydrocarbons (PAH) in water-unsaturated soil over the range of centimeters, thereby efficiently mobilizing hydrophobic PAH beyond their purely diffusive transport in air and water. However, the question if mycelia-based PAH transport has an effect on PAH biodegradation was so far unsolved. To address this, we developed a laboratory model microcosm mimicking air-water interfaces in soil. Chemical analyses demonstrated transport of the PAH fluorene (FLU) by the mycelial oomycete Pythium ultimum that was grown along the air-water interfaces. Furthermore, degradation of mycelia-transported FLU by the bacterium Burkholderia sartisoli RP037-mChe was indicated. Since this organism expresses eGFP in response to a FLU flux to the cell, it was also as a bacterial reporter of FLU bioavailability in the vicinity of mycelia. Confocal laser scanning microscopy (CLSM) and image analyses revealed a significant increase of eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU. Hence, we could show that physically separated FLU becomes bioavailable to bacteria after transport by mycelia. Experiments with silicon coated glass fibers capturing mycelia-transported FLU guided us to propose a three-step mechanism of passive uptake, active transport and diffusion-driven release. These experiments were also used to evaluate the contributions of these individual steps to the overall mycelial FLU transport rate.

  17. Alcohol-soluble interfacial fluorenes for inverted polymer solar cells: sequence induced spatial conformation dipole moment.

    PubMed

    Chen, Lie; Liu, Xiangfu; Wei, Yingkai; Wu, Feiyan; Chen, Yiwang

    2016-01-21

    Three fluorene-based alcohol-soluble organic small molecule electrolytes (SMEs) with different conjugated backbones, namely, TFTN-Br, FTFN-Br and FTTFN-Br, were designed as cathode interfacial layers for inverted polymer solar cells (i-PSCs). The insertion of SMEs to the ITO/active layer interfaces effectively lowered the energy barrier for electron transport and improved the inherent compatibility between the hydrophilic ITO and hydrophobic active layers. Due to these advantages, the device based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C61 butyric acid methyl ester (PC61BM) with TFTN-Br as the cathode interfacial layer achieved an improved power conversion efficiency (PCE) of 3.8%, which is a 26% improvement when compared to the standard device comprising ZnO cathode interfacial layers (PCE = 3.0%). Devices with FTFN-Br and FTTFN-Br also showed an improved PCE of 3.1% and 3.5%, respectively. The variation in device performance enhancement was found to be primarily correlated with the different conformation of their assembly onto the electrode caused by the joint sequence of the polar group of the SMEs, consequently impacting the dipole moment and interface morphology. In addition, introducing SMEs as the cathode interfacial layer also produced devices with long-term stability.

  18. Salicylyl Fluorene Derivatives as Fluorescent Sensors for Cu(II) Ions.

    PubMed

    Khaokeaw, Chenwit; Sukwattanasinitt, Mongkol; Rashatasakhon, Paitoon

    2016-03-01

    Two derivatives of fluorene containing salicylic acid groups are successfully synthesized by palladium-catalyzed coupling reactions and subsequent hydrolysis of salicylate esters. The compounds are characterized by various spectroscopic methods. In phosphate buffer (pH 8.0) solutions, these compounds are well soluble. They show maximum absorption wavelengths in the range of 304-330 nm and exhibit maximum emission wavelength around 420 and 430 nm with the quantum yields of 2.7 and 4.4 %, respectively. The compound with alkynyl salicylate groups (2) exhibits a selective fluorescence quenching towards Cu(II) and Fe(II) with a relatively similar sensitivity. The selectivity favoring Cu(II) over Fe(II) and other metal ions can be achieved upon the addition of 30 μM Triton X-100. The Cu(II) detection limit in solution phase is 1.47 ppb. The fluorescence signal recovery upon the addition of EDTA indicate a reversible complexation between 2 and Cu(II) ion. Fabrication of 2 on filter paper using a 50 μM solution in THF affords a naked-eye detection for Cu(II) and Fe(II) in aqueous media at picomole level. PMID:26753759

  19. High thermal stability fluorene-based hole-injecting material for organic light-emitting devices

    NASA Astrophysics Data System (ADS)

    Li, Lu; Jiao, Bo; Li, Sanfeng; Ma, Lin; Yu, Yue; Wu, Zhaoxin

    2016-03-01

    Novel N1,N3,N5-tris(9,9-diphenyl-9H-fluroen-2-yl)-N1,N3,N5-triphenylbenzene-1,3,5-triamine (TFADB) was synthesized and characterized as a hole-injecting material (HIM) for organic light-emitting devices (OLEDs). By incorporating fluorene group TFADB shows a high glass-transition temperature Tg > 168 °C, indicative of excellent thermal stability. TFADB-based devices exhibited the highest performance in terms of the maximum current efficiency (6.0 cd/A), maximum power efficiency (4.0 lm/W), which is improved than that of the standard device based on 4-4‧-4″Tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine (2T-NATA) (5.2 cd/A, 3.6 lm/W). This material could be a promising hole-injecting material, especially for the high temperature applications of OLEDs and other organic electronic devices.

  20. Coordination polymers assembled from semirigid fluorene-based ligand: A couple of enantiomers

    NASA Astrophysics Data System (ADS)

    Li, Liang; Wang, Zihao; Chen, Qiang; Zhou, Xinhui; yang, Tao; Zhao, Qiang; Huang, Wei

    2015-11-01

    A couple of Mg(II)-based coordination polymer enantiomers [MgL(DMF)(H2O)3]n (R-MgL and S-MgL), and a Zn(II)-based coordination polymer [ZnL(DMF)]n (ZnL) have been synthesized by the solvothermal reactions between the achiral ligand 4,4‧-(9,9-dimethyl-9H-fluorene-2,7-diyl)dibenzoic acid (H2L) and the corresponding metal salts. The MgL was obtained as the racemic conglomerate from the one pot reaction. The single crystal X-ray structural analyses reveal that MgL crystallize in the chiral space group P21 and possesses the right- or left-handed homochiral 1D Mg-O-C helical chain. The ZnL crystallize in the non-centrosymmetrical space group Aba2 and possesses the 2D network comprised of 1D Zn-O-C meso-helical chains and ligands. The MgL and ZnL complexes exhibit strong coordination-perturbed ligand-centered blue emissions when excited at 320 nm. Their second-order nonlinear optical effects and thermal properties have also been studied.

  1. Aqueous photodegradation and toxicity of the polycyclic aromatic hydrocarbons fluorene, dibenzofuran and dibenzothiophene

    PubMed Central

    Shemer, Hilla; Linden, Karl G.

    2007-01-01

    Decay kinetics resulting from the application of UV and UV/H2O2 to the polycyclic aromatic hydrocarbons (PAHs) fluorene, dibenzofuran and dibenzothiophene was studied. Batch experiments were conducted with both low pressure monochromatic (253.7 nm) and medium pressure polychromatic (200–300 nm) UV sources alone or in the presence of up to 25 mg/L hydrogen peroxide, in a quasi-collimated beam apparatus. Degradation of all three PAHs, by both UV and UV/H2O2, exhibited pseudo-first order reaction kinetics and low quantum yields ranging from 1.4×10−3 to 1.8×10−2 mol/E using both UV lamps. Toxicity testing using a bioluminesence inhibition bioassay was correlated to the decay in concentration of the PAHs as analyzed analytically using HPLC. Results demonstrated that treatment efficacy of oxidative PAH degradation measured by following the decay of the target compound is best complemented by also evaluating the toxicity of the treated water due to byproduct formation concerns. PMID:17217979

  2. Alcohol-soluble interfacial fluorenes for inverted polymer solar cells: sequence induced spatial conformation dipole moment.

    PubMed

    Chen, Lie; Liu, Xiangfu; Wei, Yingkai; Wu, Feiyan; Chen, Yiwang

    2016-01-21

    Three fluorene-based alcohol-soluble organic small molecule electrolytes (SMEs) with different conjugated backbones, namely, TFTN-Br, FTFN-Br and FTTFN-Br, were designed as cathode interfacial layers for inverted polymer solar cells (i-PSCs). The insertion of SMEs to the ITO/active layer interfaces effectively lowered the energy barrier for electron transport and improved the inherent compatibility between the hydrophilic ITO and hydrophobic active layers. Due to these advantages, the device based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C61 butyric acid methyl ester (PC61BM) with TFTN-Br as the cathode interfacial layer achieved an improved power conversion efficiency (PCE) of 3.8%, which is a 26% improvement when compared to the standard device comprising ZnO cathode interfacial layers (PCE = 3.0%). Devices with FTFN-Br and FTTFN-Br also showed an improved PCE of 3.1% and 3.5%, respectively. The variation in device performance enhancement was found to be primarily correlated with the different conformation of their assembly onto the electrode caused by the joint sequence of the polar group of the SMEs, consequently impacting the dipole moment and interface morphology. In addition, introducing SMEs as the cathode interfacial layer also produced devices with long-term stability. PMID:26694627

  3. Constraint on the potassium content for the superconductivity of potassium-intercalated phenanthrene

    SciTech Connect

    Huang, Qiao-Wei; Zhao, Xiao-Miao; Zhong, Guo-Hua; Zhang, Jiang; Zhang, Chao; Lin, Hai-Qing; Chen, Xiao-Jia

    2014-03-21

    Raman-scattering measurements were performed on K{sub x}phenanthrene (0 ⩽ x ⩽ 6.0) at room temperature. Three phases (x = 3.0, 3.5, and 4.0) are identified based on the obtained Raman spectra. Only the K{sub 3}phenanthrene phase is found to exhibit the superconducting transition at 5 K. The C–C stretching modes are observed to broaden and become disordered in K{sub x}phenanthrene with x = 2.0, 2.5, 6.0, indicating some molecular disorder in the metal intercalation process. This disorder is expected to influence the nonmetallic nature of these materials. The absence of metallic character in these nonsuperconducting phases is found from the calculated electronic structures based on the local density approximation.

  4. Toxicity of phenanthrene in freshwater sediments to the rooted submersed macrophyte, Vallisneria spiralis.

    PubMed

    Yan, Zai S; Hu, Ying; Jiang, He L

    2011-08-01

    A study was conducted to determine the response of the rooted submersed macrophyte, Vallisneria spiralis to phenanthrene in freshwater sediments with initial phenanthrene concentrations from 0 to 80 mg kg(-1) dry sediment. The sensitivity of various morphological endpoints was evaluated after 90 days of exposure. The most sensitive toxicity test endpoints were those that reflected root growth. Toxicological sensitivity of the endpoints changed with the effect level selected. The toxicity threshold from a plot of the EC(10) values was 1-2 orders of magnitude lower than those calculated for the threshold from plots of the EC(25) or EC(50) values. In addition, stimulatory responses (hormesis) on root growth were observed at subtoxic concentrations of phenanthrene, and a hormetic model should thus be incorporated for ecological risk assessment. PMID:21643831

  5. Acoustic studies of ternary mixture phenanthrene toluene heptane as a model of natural flocculating system

    NASA Astrophysics Data System (ADS)

    Bucek, M.; Marczak, W.

    2008-02-01

    Complexity of natural systems causes that results of experimental studies are often ambiguous and extremely unrewarding in interpretation. To overcome this difficulty, relative simple model systems may be investigated in order to provide physical grounds for further discussion. This study deals with adiabatic compressibility of liquid ternary system consisting of phenanthrene, toluene and heptane. Increase of heptane concentration in the mixture changes considerably the partial compressibility of phenanthrene, from common positive value in pure toluene up to clearly negative ones. This is most probably because of self-association of phenanthrene due to strong London forces. Heptane seems to promote the self-association. These feature of the investigated system suggests its usefulness in studies of flocculation of asphaltenes from crude oils.

  6. Constraint on the potassium content for the superconductivity of potassium-intercalated phenanthrene.

    PubMed

    Huang, Qiao-Wei; Zhong, Guo-Hua; Zhang, Jiang; Zhao, Xiao-Miao; Zhang, Chao; Lin, Hai-Qing; Chen, Xiao-Jia

    2014-03-21

    Raman-scattering measurements were performed on K(x)phenanthrene (0 ⩽ x ⩽ 6.0) at room temperature. Three phases (x = 3.0, 3.5, and 4.0) are identified based on the obtained Raman spectra. Only the K3phenanthrene phase is found to exhibit the superconducting transition at 5 K. The C-C stretching modes are observed to broaden and become disordered in K(x)phenanthrene with x = 2.0, 2.5, 6.0, indicating some molecular disorder in the metal intercalation process. This disorder is expected to influence the nonmetallic nature of these materials. The absence of metallic character in these nonsuperconducting phases is found from the calculated electronic structures based on the local density approximation. PMID:24655174

  7. Identification of soil bacteria able to degrade phenanthrene bound to a hydrophobic sorbent in situ.

    PubMed

    Regonne, Raïssa Kom; Martin, Florence; Mbawala, Augustin; Ngassoum, Martin Benoît; Jouanneau, Yves

    2013-09-01

    Efficient bioremediation of PAH-contaminated sites is limited by the hydrophobic character and poor bioavailability of pollutants. In this study, stable isotope probing (SIP) was implemented to track bacteria that can degrade PAHs adsorbed on hydrophobic sorbents. Temperate and tropical soils were incubated with (13)C-labeled phenanthrene, supplied by spiking or coated onto membranes. Phenanthrene mineralization was faster in microcosms with PAH-coated membranes than in microcosms containing spiked soil. Upon incubation with temperate soil, phenanthrene degraders found in the biofilms that formed on coated membranes were mainly identified as Sphingomonadaceae and Actinobacteria. In the tropical soil, uncultured Rhodocyclaceae dominated degraders bound to membranes. Accordingly, ring-hydroxylating dioxygenase sequences recovered from this soil matched PAH-specific dioxygenase genes recently found in Rhodocyclaceae. Hence, our SIP approach allowed the detection of novel degraders, mostly uncultured, which differ from those detected after soil spiking, but might play a key role in the bioremediation of PAH-polluted soils.

  8. The influence of mechanochemical modification on prevention of toxic ability of humic acids towards phenanthrene in aquatic environment

    NASA Astrophysics Data System (ADS)

    Shekhovtsova, N. S.; Maltseva, E. V.; Glyzina, T. S.; Ovchinnikova, I. S.

    2015-11-01

    The aim of the research work is to quantify interaction between phenanthrene with modified humic acids in aquatic environment. The changes in the structure and properties of humic acids after modifications were studied with 1H NMR spectroscopy and potentiometric titration methods. Our research demonstrates that the application of thiourea as a modified agent increases the binding capacity of humic acids towards phenanthrene.

  9. MEASURING GROWTH OF A PHENANTHRENE DEGRADING BACTERIAL INOCULUM IN SOIL WITH A QUANTITATIVE COMPETITIVE POLYMERASE CHAIN REACTION METHOD. (R825433)

    EPA Science Inventory

    We measured growth of a phenanthrene-degrading bacterium, Arthrobacter, strain RP17, in Forbes soil, amended with 500 small mu, Greekg g−1 phenanthrene using a quantitati...

  10. Effect of Model Sorptive Phases on Phenanthrene Biodegradation: Molecular Analysis of Enrichments and Isolates Suggests Selection Based on Bioavailability

    PubMed Central

    Friedrich, M.; Grosser, R. J.; Kern, E. A.; Inskeep, W. P.; Ward, D. M.

    2000-01-01

    Reduced bioavailability of nonpolar contaminants due to sorption to natural organic matter is an important factor controlling biodegradation of pollutants in the environment. We established enrichment cultures in which solid organic phases were used to reduce phenanthrene bioavailability to different degrees (R. J. Grosser, M. Friedrich, D. M. Ward, and W. P. Inskeep, Appl. Environ. Microbiol. 66:2695–2702, 2000). Bacteria enriched and isolated from contaminated soils under these conditions were analyzed by denaturing gradient gel electrophoresis (DGGE) and sequencing of PCR-amplified 16S ribosomal DNA segments. Compared to DGGE patterns obtained with enrichment cultures containing sand or no sorptive solid phase, different DGGE patterns were obtained with enrichment cultures containing phenanthrene sorbed to beads of Amberlite IRC-50 (AMB), a weak cation-exchange resin, and especially Biobead SM7 (SM7), a polyacrylic resin that sorbed phenanthrene more strongly. SM7 enrichments selected for mycobacterial phenanthrene mineralizers, whereas AMB enrichments selected for a Burkholderia sp. that degrades phenanthrene. Identical mycobacterial and Burkholderia 16S rRNA sequence segments were found in SM7 and AMB enrichment cultures inoculated with contaminated soil from two geographically distant sites. Other closely related Burkholderia sp. populations, some of which utilized phenanthrene, were detected in sand and control enrichment cultures. Our results are consistent with the hypothesis that different phenanthrene-utilizing bacteria inhabiting the same soils may be adapted to different phenanthrene bioavailabilities. PMID:10877758

  11. Toxicity of sediment-associated pyrene and phenanthrene to Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae)

    SciTech Connect

    Lotufo, G.R.; Fleeger, J.W.

    1996-09-01

    Acute and sublethal toxicities of sediment-spiked pyrene and phenanthrene to Limnodrilus hoffmeisteri Cleparede were investigated. Phenanthrene was acutely toxic at high sediment concentrations (10-d median lethal concentration of 297.5 {micro}g g{sup {minus}1}; 252.2--348.3, 95% confidence interval [Cl]). Pyrene was not acutely toxic, even at concentrations as high as 841 {micro}g g{sup {minus}1}. A significant impact of pyrene and phenanthrene on the feeding activity of L. hoffmeisteri was demonstrated through daily collection of egested fecal material during 5- and 10-d experiments. A short (5-d) exposure detected toxic effects more efficiently than a 10-d exposure, yielding IC25 values (estimated concentration causing a 25% reduction of measured endpoint in relation to the control[s]) of 58.9 {micro}g g{sup {minus}1} (32.1--89.4, 95% CI) for pyrene and 28.4 {micro}g g{sup {minus}1} (10.0--41.3, 95% CI) for phenanthrene. Effects on burrowing behavior and reproduction were assessed in a 28-d sediment exposure. Low burrowing avoidance (< 25%) was detected in high phenanthrene concentrations (143--612 {micro}g g{sup {minus}1}) but was not detected with pyrene. Offspring production was significantly reduced in dosed sediments yielding IC25 values of 59.1 {micro}g g{sup {minus}1} (38.3--112.5, 95% CI) for pyrene and 40.5 {micro}g g{sup {minus}1} (12.1--165.5, 955 CI) for phenanthrene. Decreases in egestion rates in the presence of nonpolar contaminants should be quantified when investigating the effects of bioturbation by deposit feeders on the flux of contaminants from sediment into the water column.

  12. Correlation between biological and physical availabilities of phenanthrene in soils and soil humin in aging experiments

    SciTech Connect

    White, J.C.; Hunter, M.; Nam, K.; Pignatello, J.J.; Alexander, M.

    1999-08-01

    The bioavailability of an organic compound in a soil or sediment commonly declines with the soil-chemical contact time (aging). A series of parallel desorption and bioavailability experiments was carried out on phenanthrene previously aged up to {approximately}100 d in Mount Pleasant silt loam (Mt. Pleasant, NY, USA) or Pahokee peat soil to determine as a function of the aging period the degree of correlation between the reduction in bioavailability and the rate and extent of desorption and the influence of soil organic matter composition on availability. The mineralization of phenanthrene by two bacteria and the uptake of phenanthrene by earthworms showed expected declines with aging. Likewise, the rate of phenanthrene desorption in the absence of organisms decreased with aging. The decline in initial rate of mineralization or desorption was nearly an order of magnitude after 50 to 60 d of aging. Plots of normalized rates of mineralization or desorption practically coincided. Similarly, plots of normalized fraction mineralized or fraction desorbed during an arbitrary period gave comparable slopes. The partial removal of organic matter from the peat by extraction with dilute NaOH to leave the humin fraction reduced the biodegradation of phenanthrene aged for 38 and 63 d as compared to the nonextracted peat, but the effect disappeared at longer incubation times. The rate of desorption from samples of peat previously extracted with NaOH or Na{sub 4}P{sub 2}O{sub 7} declined with aging and, for a given aging period, was significantly slower than from nonextracted peat. This work shows that the reduction in bioavailability of phenanthrene over time in soil is directly correlated with reduction of its physical availability due to desorption limitations. In addition, this study shows that removal of extractable humic substances leads to a decline in the rate of desorption and in the bioavailability of the substrate.

  13. Effect of microbial polymers on the sorption and transport of phenanthrene in a low-carbon sand

    SciTech Connect

    Dohse, D.M.; Lion, L.W. )

    1994-04-01

    Extracellular polymers of bacterial origin were analyzed for their effect on the sorption behavior of phenanthrene on a low-carbon aquifer sand. Batch experiments indicated that 85% of the polymers tested acted to decrease the distribution coefficient. Column experiments revealed a decrease in the retardation factor of phenanthrene by approximately 40% in the presence of an extracellular polymer produced by a Gram-negative motile rod isolated from a coal tar waste site. This polymer did not, however, influence the mineralization of phenanthrene and was not rapidly degraded by a mixed culture. The combination of the ability of the polymer to influence phenanthrene transport as well as its apparent persistence and lack of a negative effect on phenanthrene degradation suggest the extracellular polymers can act as agents that enhance PAH transport in natural systems. 50 refs., 8 figs., 2 tabs.

  14. Uptake and elimination of (9-/sup 14/C)phenanthrene in the turkey wing mussel (Arca zebra)

    SciTech Connect

    Solbakken, J.E.; Knap, A.H.; Searle, C.E.; Palmork, K.H.

    1983-04-01

    Turkey wing mussels of both sexes were collected from Harrington Sound, Bermuda and dosed after a week-long acclimation period with (9-/sup 14/C)phenanthrene (714 MBq/mmol). They were transferred into 8 liters of seawater containing 8 ..mu..g of labelled phenanthrene. Results show that the accumulation of labelled phenanthrene in the turkey wing mussel was very low compared to that found in other species. In the hepatopancreas, the uptake of phenanthrene based on the water concentration was only 4% of the corresponding value found in the calico clam (Macrocallista maculata) inhabiting the same area. In comparison, the uptake of phenanthrene in a temperate mollusc such as the horse mussel (Modiola modiolus) was also considerably higher than in the turkey wing (approx. 4 times). It therefore seems likely that these are due to species variations rather than environmental variations between subtropical and temperate areas. (JMT)

  15. Enantiomeric composition of the trans-dihydrodiols produced from phenanthrene by fungi

    SciTech Connect

    Sutherland, J.B.; Fu, P.P.; Von Tungeln, L.S.; Cerniglia, C.E. ); Yang, S.K. ); Casillas, R.P.; Crow, S.A. )

    1993-07-01

    Phenanthrene and other polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants. PAHs are frequently bioaccumulated by animals and can be activated to mutagenic and carcinogenic metabolites, but they are resistant to biodegradation by microorganisms. Although PAHs do not generally serve as carbon or energy sources for fungi, many fungi cometabolize one or more PAHs to trans-dihydrodiols. In this study, circular dichroism spectroscopy and chiral stationary-phase high-performance liquid chromatography is used to compare the stereoselectivity of three species of fungi that metabolize phenanthrene to trans-dihydrodiols, Cunninghamella elegans, Syncephalastrum racemosum, and Phanerochaete chrysosporium. 30 refs., 5 figs., 1 tab.

  16. Reaction of phenanthrene with tert-butylating agents under Friedel-Craft conditions

    SciTech Connect

    Pozdnyakovich, Yu.V.

    1988-10-20

    The alkylation of phenanthrene with tert-butyl alcohol in the presence of trifluoroacetic acid or with tert-butyl chloride, catalyzed by the TiCl/sub 4/, FeCl/sub 3/-CH/sub 3/NO/sub 2/, and AlCl/sub 3/-CH/sub 3/NO/sub 2/, leads to formation of 2- and 3-tert-butylphenanthrene and also 2,6-, 2,7-, and 3,6-di-tert-butylphenanthrene. The exhaustive alkylation of phenanthrene leads to the formation of the above-mentioned isomeric di-tert-butylphenanthrenes, the ratios of which depend on the nature of the catalyst.

  17. Synthesis and Luminescent Properties of Poly(9-(3-vinyl-phenyl)-phenanthrene).

    PubMed

    Yang, Garam; Lee, Hayoon; Lee, Suji; Jung, Hyocheol; Shin, Hwangyu; Lee, Jaehyun; Park, Jongwook

    2016-02-01

    Recently, interest of polymer light-emitting diode (PLED) fabricated from conjugated polymer has augmented because PLED has advantage property that is well-suited to flexible lighting and solution processed device. In this presentation, we suggest a new polymer host based on phenanthrene, poly(9-(3-Vinyl-phenyl)-phenanthrene) (PVPP). It can be easily synthesized through simple synthetic methods which are Suzuki and Wittig reactions. PVPP film can be obtained from spin coating with solution used by common solvent. It exhibited PL maximum value of 381 nm and broad PL spectrum. Energy transfer smoothly occurred when the three dopants for green, red and yellow were used in PVPP. PMID:27433663

  18. Different effects of copper (II), cadmium (II) and phosphate on the sorption of phenanthrene on the biomass of cyanobacteria.

    PubMed

    Tao, Yuqiang; Li, Wei; Xue, Bin; Zhong, Jicheng; Yao, Shuchun; Wu, Qinglong

    2013-10-15

    Due to the large surface area and high organic carbon content of cyanobacteria, organic contaminants can be readily sorbed on cyanobacteria during algal blooms, and then be transferred to the food web. This process is likely to be affected by the coexisting metals and nutrients, however, the possible impacts remain unclear. Effects of Cu(2+), Cd(2+), and phosphate on the sorption of phenanthrene on cyanobacterial biomass collected from an algal bloom were therefore studied. Continuous decrease in phenanthrene sorption was observed in the presence of low concentrations of Cu(2+), and Cd(2+) (<0.04 mmol L(-1)), because Cu(2+) and Cd(2+) were coadsorbed with phenanthrene on the surface of cyanobacteria as suggested by scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and Fourier transform infrared (FTIR) analyses. Phenanthrene sorption began to increase with the further increase in Cu(2+) concentration, but remained lower than that in the absence of Cu(2+). This increase in sorption was ascribed to the cation-π interaction between Cu(2+) and phenanthrene, as suggested by the enhanced ultraviolet absorbance at 251 nm. In contrast, sorption rebounding of phenanthrene did not occur in the presence of higher concentrations of Cd(2+). The different effects of Cu(2+) and Cd(2+) on phenanthrene sorption were attributed to that Cd(2+) required much more energy than Cu(2+) to form cation-π complexes with phenanthrene in the solutions. Phenanthrene sorption decreased continuously with the increase in phosphate concentration. Phosphate blocked the binding sites, modified the cell morphology, and increased the negative charge as well as the hydrophilicity of the cyanobacterial surface, thereby suppressing phenanthrene sorption. This study indicates that sorption of aromatic organic compounds by cyanobacteria could be significantly alerted by concentrations and properties of the coexisting transition metals and phosphates, which may subsequently affect their

  19. Syntheses and Chemosensory of Anthracene and Phenanthrene Bisimide Derivatives

    NASA Technical Reports Server (NTRS)

    Bogusz, Zachary A.

    2004-01-01

    As the present technology of biochemical weapons advances, it is essential for science to attempt to prepare our nation for such an occurrence. Various areas of current research are devoted to precautionary measures and potential antidotes for national security. A practical application of these precautions would be the development of a chemical capable of detecting harmful gas. The benefits of being capable to synthesis a chemical compound that would warn and identify potentially deadly gases would ensure a higher level of safety. The chemicals in question can be generalized as bisimide anthracene derivatives. The idea behind these compounds is that in the presence of certain nerve gases, the compound will actually fluoresce, giving an indication that there is a strong likelihood of the presence of a nerve gas and ensure the proper precautionary measures are taken. The fluorescence is due to the quenching of an electric proton transfer within the structure of the molecule. The system proves to be very unique on account of the fact that the fluorescence can be "turned off" by reducing the system. By utilizing the synthesis designed by Dr. Faysal Ilhan, four distinct compounds can be synthesized through photochemical reactions involving para- and ortho- diketones. The photochemistry involved is very modem and much research is being devoted to fully understanding the possibilities and alternative applications of such materials. and meta-nitro anthracene bisimide (ABI-NO2), the amine of each (ABI-NH2), a para- and meta-nitro phenanthrene bisimjde (PBI-NO2), and the amine of each (PBI-NH2). Upon synthesizing these distinct compounds, I must then purify and analyze them in order to obtain any relevant trends, behaviors, and characteristics. The chemical composition analyses that will be conducted are the procedures taken by Dr. Daniel Tyson on previous experiments. The results generated from the data will point further research in the correct direction and hopefully

  20. Novel 7-(dimethylamino)fluorene-based fluorescent probes and their binding to human serum albumin.

    PubMed

    Park, Kwanghee Koh; Park, Joon Woo; Hamilton, Andrew D

    2009-10-21

    A novel solvatochromic fluorescent molecule, 9,9-dibutyl-7-(dimethylamino)-2-fluorenesulfonate 2 was synthesized from 2-nitrofluorene in moderate yield. The fluorescence spectra of 2 and 7-(dimethylamino)-2-fluorenesulfonate 1 shift to shorter wavelengths as the polarity of the medium decreases. Both 1 and 2 bind to hydrophobic sites of human serum albumin (HSA). The apparent binding constants were determined by fluorescence titration to be 0.37 x 10(6) M(-1) for 1 and 2.2 x 10(6) M(-1) for 2. The energy of the Trp-214 fluorescence of HSA is transferred to the HSA-bound fluorophores with near 100% efficiency. The covalent bonding of acrylodan (AC) to Cys-34 has little effect on the binding affinity of 2 to HSA or fluorescent behavior of HSA-bound 2. Bound 2 also has little effect on the fluorescence of AC, but 2-->AC and Trp-214-->2-->AC resonance energy transfers were observed. Competitive binding between the fluorene compounds and other ligands such as 1-anilino-8-naphthalenesulfonate, aspirin, S-(+)-ibuprofen and phenylbutazone were also studied fluorometrically. The results indicated that the primary binding site of 2 to HSA is site II in domain IIIA, whereas 1 binds to site I in domain IIA, but a different region from the phenylbutazone binding site. Because of its large molar absorptivity, strong fluorescence, sensitivity to its environment, and high binding constant to HSA, 2 can be used successfully in the study of proteins and their binding properties. PMID:19795061

  1. Phytoremediation of phenanthrene by transgenic plants transformed with a naphthalene dioxygenase system from Pseudomonas.

    PubMed

    Peng, Ri-He; Fu, Xiao-Yan; Zhao, Wei; Tian, Yong-Sheng; Zhu, Bo; Han, Hong-Juan; Xu, Jing; Yao, Quan-Hong

    2014-11-01

    Genes from microbes for degrading polycyclic aromatic hydrocarbons (PAHs) are seldom used to improve the ability of plants to remediate the pollution because the initiation of the microbial degradation of PAHs is catalyzed by a multienzyme system. In this study, for the first time, we have successfully transferred the complex naphthalene dioxygenase system of Pseudomonas into Arabidopsis and rice, the model dicot and monocot plant. As in bacteria, all four genes of the naphthalene dioxygenase system can be simultaneously expressed and assembled to an active enzyme in transgenic plants. The naphthalene dioxygenase system can develop the capacity of plants to tolerate a high concentration of phenanthrene and metabolize phenanthrene in vivo. As a result, transgenic plants showed improved uptake of phenanthrene from the environment over wild-type plants. In addition, phenanthrene concentrations in shoots and roots of transgenic plants were generally lower than that of wild type plants. Transgenic plants with a naphthalene dioxygenase system bring the promise of an efficient and environmental-friendly technology for cleaning up PAHs contaminated soil and water.

  2. Preparation and characterization of a novel graphene/biochar composite for aqueous phenanthrene and mercury removal.

    PubMed

    Tang, Jingchun; Lv, Honghong; Gong, Yanyan; Huang, Yao

    2015-11-01

    A graphene/biochar composite (G/BC) was synthesized via slow pyrolysis of graphene (G) pretreated wheat straw, and tested for the sorption characteristics and mechanisms of representative aqueous contaminants (phenanthrene and mercury). Structure and morphology analysis showed that G was coated on the surface of biochar (BC) mainly through π-π interactions, resulting in a larger surface area, more functional groups, greater thermal stability, and higher removal efficiency of phenanthrene and mercury compared to BC. Pseudo second-order model adequately simulated sorption kinetics, and sorption isotherms of phenanthrene and mercury were simulated well by dual-mode and BET models, respectively. FTIR and SEM analysis suggested that partitioning and surface sorption were dominant mechanisms for phenanthrene sorption, and that surface complexation between mercury and C-O, CC, -OH, and OC-O functional groups was responsible for mercury removal. The results suggested that the G/BC composite is an efficient, economic, and environmentally friendly multifunctional adsorbent for environmental remediation. PMID:26255599

  3. Influence of Multiple Bacterial Populations on Phenanthrene Degradation, Bacterial Cell Elution, and Species Distribution

    NASA Astrophysics Data System (ADS)

    Patterson, B. M.; Brusseau, M. L.; Maier, R. M.; Frye, R.

    2001-05-01

    A single set of degradation coefficients is typically used when representing biodegradation in contaminant transport models. Implicit to this approach is the assumption that only a single degrading isolate exists, or that the entire community of degraders more typically present in natural systems has a uniform, constant growth rate and affinity for the contaminant. This assumption was evaluated through a miscible displacement experiment conducted using a column packed with a soil containing an indigenous microbial community comprised of 24 identified phenanthrene-degrading isolates. Results produced oscillating phenanthrene concentrations in the column effluent, indicating potential competitive interactions among the isolates. A second series of experiments, conducted in a simplified system comprised of sand and 1,2, or 3 indigenous isolates, examined the effects of species interactions on phenanthrene degradation and bacterial cell elution. Bacterial growth rates, density of cells within the column, and bacterial distribution were also evaluated. Results show single bacterial species produced relatively stable cell elution and phenanthrene concentrations in the effluent. Conversely, the behavior in the multiple species systems indicated synergistic and antagonistic interactions occurred among the species. These results illustrate that the dynamics of heterogeneous microbial communities should be considered when evaluating contaminant biodegradation and transport in subsurface systems.

  4. Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing

    PubMed Central

    Luo, Chunling; Zhang, Dayi; Zhang, Gan

    2015-01-01

    Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP). The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP) results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ. PMID:26098417

  5. COSOLVENT EFFECTS ON PHENANTHRENE SORPTION-DESORPTION ON A FRESH-WATER SEDIMENT

    EPA Science Inventory

    This study evaluated the effects of the water-miscible cosolvent methanol on the sorption-desorption of phenanthrene by the natural organic matter (NOM) of a fresh-water sediment. A biphasic pattern was observed in the relationship between the log of the carbon-normalized sorpti...

  6. Preparation and characterization of a novel graphene/biochar composite for aqueous phenanthrene and mercury removal.

    PubMed

    Tang, Jingchun; Lv, Honghong; Gong, Yanyan; Huang, Yao

    2015-11-01

    A graphene/biochar composite (G/BC) was synthesized via slow pyrolysis of graphene (G) pretreated wheat straw, and tested for the sorption characteristics and mechanisms of representative aqueous contaminants (phenanthrene and mercury). Structure and morphology analysis showed that G was coated on the surface of biochar (BC) mainly through π-π interactions, resulting in a larger surface area, more functional groups, greater thermal stability, and higher removal efficiency of phenanthrene and mercury compared to BC. Pseudo second-order model adequately simulated sorption kinetics, and sorption isotherms of phenanthrene and mercury were simulated well by dual-mode and BET models, respectively. FTIR and SEM analysis suggested that partitioning and surface sorption were dominant mechanisms for phenanthrene sorption, and that surface complexation between mercury and C-O, CC, -OH, and OC-O functional groups was responsible for mercury removal. The results suggested that the G/BC composite is an efficient, economic, and environmentally friendly multifunctional adsorbent for environmental remediation.

  7. Effect of surfactant on phenanthrene metabolic kinetics by Citrobacter sp. SA01.

    PubMed

    Li, Feng; Zhu, Lizhong; Zhang, Dong

    2014-11-01

    To attain a better understanding of the effects of surfactants on the metabolic kinetics of hydrophobic organic compounds, the biodegradation of phenanthrene by Citrobacter sp. SA01 was investigated in a batch experiment containing Tween 80, sodium dodecyl benzene sulfonate and liquid mineral salt medium. The Monod model was modified to effectively describe the partition, phenanthrene biodegradation and biopolymer production. The results showed that Tween 80 and sodium dodecyl benzene sulfonate (each at 50mg/L) enhanced phenanthrene metabolism and poly-β-hydroxybutyrate production as indicated by the increasing amounts of intermediates (by 17.2% to 47.9%), and percentages of poly-β-hydroxybutyrate (by 107.3% and 33.1%) within the cell dry weight when compared to their absence. The modified Monod model was capable of predicting microbial growth, phenanthrene depletion and biopolymer production. Furthermore, the Monod kinetic coefficients were largely determined by the surfactant-enhanced partition, suggesting that partitioning is a critical process in surfactant-enhanced bioremediation of hydrophobic organic compounds.

  8. Distribution of phenanthrene between soil and an aqueous phase in the presence of anionic micelle-like amphiphilic polyurethane particles.

    PubMed

    Lee, Kangtaek; Choi, Heon-Sik; Kim, Ju-Young; Ahn, Ik-Sung

    2003-12-12

    Sorption of micelle-like amphiphilic polyurethane (APU) particles to soil was studied and compared to that of a model anionic surfactant, sodium dodecyl sulfate (SDS). Three types of APU particles with different hydrophobicity were synthesized from urethane acrylate anionomers (UAA) and used in this study. Due to the chemically cross-linked structure, APU exhibited less sorption to the soil than SDS and a greater reduction in the sorption of phenanthrene, a model soil contaminant, to the soil was observed in the presence of APU than SDS even though the solubility of phenanthrene was higher in the presence of SDS than APU. A mathematical model was developed to describe the phenanthrene distribution between soil and an aqueous phase containing APU particles. The sorption of phenanthrene to the test soil could be well described by Linear isotherm. APU sorption to the soil was successfully described by Langmuir and Freundlich isotherms. The partition of phenanthrene between water and APU were successfully explained with a single partition coefficient. The model, which accounts for the limited solubilization of phenanthrene in sorbed APU particles, successfully described the experimental data for the distribution of phenanthrene between the soil and the aqueous phase in the presence of APU.

  9. Rapid degradation of phenanthrene by using Sphingomonas sp. GY2B immobilized in calcium alginate gel beads.

    PubMed

    Tao, Xue-Qin; Lu, Gui-Ning; Liu, Jie-Ping; Li, Ting; Yang, Li-Ni

    2009-09-01

    The strain Sphingomonas sp. GY2B is a high efficient phenanthrene-degrading strain isolated from crude oil contaminated soils that displays a broad-spectrum degradation ability towards PAHs and related aromatic compounds. This paper reports embedding immobilization of strain GY2B in calcium alginate gel beads and the rapid degradation of phenanthrene by the embedded strains. Results showed that embedded immobilized strains had high degradation percentages both in mineral salts medium (MSM) and 80% artificial seawater (AS) media, and had higher phenanthrene degradation efficiency than the free strains. More than 90% phenanthrene (100 mg x L(-1)) was degraded within 36 h, and the phenanthrene degradation percentages were >99.8% after 72 h for immobilized strains. 80% AS had significant negative effect on the phenanthrene degradation rate (PDR) of strain GY2B during the linear-decreasing stage of incubation and preadsorption of cells onto rice straw could improve the PDR of embedded strain GY2B. The immobilization of strain GY2B possesses a good potential for application in the treatment of industrial wastewater containing phenanthrene and other related aromatic compounds.

  10. Water quality, organic chemistry of sediment, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee

    USGS Publications Warehouse

    Bradfield, A.D.; Flexner, N.M.; Webster, D.A.

    1993-01-01

    An investigation of water quality, organic sediment chemistry, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee, was conducted during December 1990. The study was designed to assess the extent of possible contamination of water and biota in the streams from creosote-related discharge originating at this Superfund site. Central Creek, adjacent to the plant, had degraded water quality and biological conditions. Water samples from the most downstream station on Central Creek contained 30 micrograms per liter of pentachlorophenol, which exceeds the State's criterion maximum concentrations of 9 micrograms per liter for fish and aquatic life. Bottom-sediment samples from stations on Central Creek contained concentrations of acenaphthene, napthalene, and phenanthrene ranging from 1,400 to 2,500 micrograms per kilogram. Chronic or acute toxicity resulted during laboratory experiments using test organisms exposed to creosote-related contaminants. Sediment elutriate samples from Central Creek caused slightly to highly toxic effects on Ceriodaphnia dubia. Pimephales promelas, and Photobacterium phosphoreum. Fish-tissue samples from this station contained concentrations of naphthalene. dibenzofuran, fluorene, and phenanthrene ranging from 1.5 to 3.9 micrograms per kilogram Blue-green algae at this station represented about 79 percent of the organisms counted, whereas diatoms accounted for only 11 percent. Benthic invertebrate and fish samples from Central Creek had low diversity and density. Sediment samples from a station on the South Fork Forked Deer River downstream from its confluence with Central Creek contained concentrations of acenaphthene, anthracene, chrysene, fluoranthene, fluorene, pyrere, and phenanthrene ranging from 2,800 to 69,000 micrograms per kilogram. Sediment elutriate samples using water as elutriate from this station contained concentrations of extractable organic compounds ranging from an estimated

  11. Behavioral toxicity and physiological changes from repeated exposure to fluorene administered orally or intraperitoneally to adult male Wistar rats: A dose-response study.

    PubMed

    Peiffer, Julie; Grova, Nathalie; Hidalgo, Sophie; Salquèbre, Guillaume; Rychen, Guido; Bisson, Jean-François; Appenzeller, Brice M R; Schroeder, Henri

    2016-03-01

    Fluorene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) in the environment by reason of its high volatility. Demonstrated to be a neurotoxicant through inhalation, it was also identified as a contributive PAH to food contamination. Since no data are available on its oral neurotoxicity, the purpose of the present study was to assess the behavioral and physiological toxicity of repeated oral administration of fluorene to adult Wistar male rats. Animals were daily treated with fluorene at 1, 10 or 100mg/kg/day for 28 consecutive days. Administration was intraperitoneal (i.p.) or oral (p.o.) to evaluate the influence of the route of exposure on fluorene toxicity. Following this period of treatment, animals in both groups were subjected to similar cognitive evaluations, namely anxiety (elevated-plus maze), locomotor activity (open-field) and learning and memory abilities (eight-arm maze and avoidance test of an aversive light stimulus), as well as physiological measurements. The behavioral testing occurred from the 28th to the 60th day of the experiment during which fluorene treatment continued uninterrupted. At the end of this period, the concentration levels of fluorene and of three of its monohydroxylated metabolites in blood and brain were determined using a GC-MS/MS method. The results demonstrated a reduction in rat anxiety level at the lowest doses administered (1 and 10mg/kg/day) regardless of the treatment route, whereas locomotor activity and learning abilities remained unchanged. Moreover, a less significant weight gain was noticed in animals i.p.- and p.o.-treated with 100mg/kg/day during the 28-day period of treatment, which, upon comparison with the three other groups, induced a body weight gap that was maintained throughout the experiment. Significant increases in relative liver weight were also observed in a dose-dependent manner in orally treated rats and only in animal treated i.p. with 100mg/kg/day. According to the dose, higher

  12. AIE-Active Fluorene Derivatives for Solution-Processable Nondoped Blue Organic Light-Emitting Devices (OLEDs).

    PubMed

    Feng, Xin Jiang; Peng, Jinghong; Xu, Zheng; Fang, Renren; Zhang, Hua-Rong; Xu, Xinjun; Li, Lidong; Gao, Jianhua; Wong, Man Shing

    2015-12-30

    A series of fluorene derivatives end-capped with diphenylamino and oxadiazolyl were synthesized, and their photophysical and electrochemical properties are reported. Aggregation-induced emission (AIE) effects were observed for the materials, and bipolar characteristics of the molecules are favored with measurement of carrier mobility and calculation of molecular orbitals using density functional theory (DFT). Using the fluorene derivatives as emitting-layer, nondoped organic light-emitting devices (OLEDs) have been fabricated by spin-coating in the configuration ITO/PEDOT:PSS(35 nm)/PVK(15 nm)/PhN-OF(n)-Oxa(80 nm)/SPPO13(30 nm)/Ca(8 nm)/Al(100 nm) (n = 2-4). The best device with PhN-OF(2)-Oxa exhibits a maximum luminance of 14 747 cd/m(2), a maximum current efficiency of 4.61 cd/A, and an external quantum efficiency (EQE) of 3.09% in the blue region. Investigation of the correlation between structures and properties indicates that there is no intramolecular charge transfer (ICT) increase in these molecules with the increase of conjugation length. The device using material of the shortest conjugation length as emitting-layer gives the best electroluminescent (EL) performances in this series of oligofluorenes. PMID:26647284

  13. Influences of humic acid on the bioavailability of phenanthrene and alkyl phenanthrenes to early life stages of marine medaka (Oryzias melastigma).

    PubMed

    Liu, Yangzhi; Yang, Chenghu; Cheng, Pakkin; He, Xiaojing; Zhu, Yaxian; Zhang, Yong

    2016-03-01

    The influences of humic acid (HA) on the environmental behavior and bioavailability of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs were investigated and compared using the early life stages of marine medaka (Oryzias melastigma, O. melastigma). It was demonstrated that the binding affinity of parent phenanthrene (PHE) with HA was smaller than that of 3-methyl phenanthrene (3-MP) and 9-ethyl phenanthrene (9-EP). Furthermore, the bioaccumulation of the three PAHs and the levels of lipid peroxidation (LPO) were calculated to study the changes in bioavailability of PAHs in presence of HA. The results indicated that the addition of HA significantly decreased the bioaccumulation and toxicity of PAHs by decreasing free PAHs concentrations. The bioavailable fractions of HA-bound PAHs in bioaccumulation (α) and toxicity (β) were evaluated, indicating that the HA-bound 3-MP and 9-EP show higher bioavailability in bioaccumulation and lower bioavailability in toxicity relative to those of PHE. The β/α values were less than 1 for all PAH treatment groups containing HA, suggesting that the fraction of HA-bound PAHs contributing to bioaccumulation was higher than that of HA-bound PAHs inducing toxic effect. In addition, we proposed that the free PAHs generated by desorption from HA in the cell were toxic by showing that the β/α ratio values are correlated with the log KOW values (p = 0.007 and R(2) = 0.8355). Thus, oil spill risk assessments should consider both alkyl PAHs and the factors that influence the bioavailability and toxicity of PAHs in the natural aquatic environments.

  14. Sorption characteristics of phenanthrene and pyrene to surfactant-modified peat from aqueous solution: the contribution of partition and adsorption.

    PubMed

    Zhou, Yanbo; Zhang, Ruzhuang; Gu, Xiaochen; Zhao, Qing; Lu, Jun

    2015-01-01

    In this paper, the sorption characteristics and mechanisms of phenanthrene and pyrene onto peat (PT) and surfactant-modified peat (MPT) were investigated. Sorption results fit closely to the Partition model and Freundlich model, the coefficient of determination (R²) were higher than 0.98 and 0.99, respectively. The contributions of partition and adsorption to the total sorption of phenanthrene and pyrene by PT and MPT were analyzed quantitatively. Results indicate that the sorption process is a combination of partition and adsorption, and partition plays a major role in the sorption process. The contribution of partition increased with the increasing of initial concentrations of polycyclic aromatic hydrocarbons. The sorption ability of phenanthrene and pyrene by PT and MPT followed the order of pyrene > phenanthrene. MPT has demonstrated potential as a promising new class of materials for environmental remediation of organic pollutants.

  15. Reduction in the earthworm metabolomic response after phenanthrene exposure in soils with high soil organic carbon content.

    PubMed

    McKelvie, Jennifer R; Whitfield Åslund, Melissa; Celejewski, Magda A; Simpson, André J; Simpson, Myrna J

    2013-04-01

    We evaluated the correlation between soil organic carbon (OC) content and metabolic responses of Eisenia fetida earthworms after exposure to phenanthrene (58 ± 3 mg/kg) spiked into seven artificial soils with OC contents ranging from 1 to 27% OC. Principal component analysis of (1)H nuclear magnetic resonance (NMR) spectra of aqueous extracts identified statistically significant differences in the metabolic profiles of control and phenanthrene-exposed E. fetida in the 1% OC soil only. Partial least squares analysis identified a metabolic response in the four soils with OC values ≤11% which was well correlated to estimated phenanthrene porewater concentrations. The results suggest that the higher sorption capability of high OC soils decreased the bioavailability of phenanthrene and the subsequent metabolic response of E. fetida. PMID:23337355

  16. Flocculant in wastewater affects dynamics of inorganic N and accelerates removal of phenanthrene and anthracene in soil.

    PubMed

    Fernandez-Luqueno, F; Thalasso, F; Luna-Guido, M L; Ceballos-Ramírez, J M; Ordoñez-Ruiz, I M; Dendooven, L

    2009-06-01

    Recycling of municipal wastewater requires treatment with flocculants, such as polyacrylamide. It is unknown how polyacrylamide in sludge affects removal of polycyclic aromatic hydrocarbons (PAH) from soil. An alkaline-saline soil and an agricultural soil were contaminated with phenanthrene and anthracene. Sludge with or without polyacrylamide was added while emission of CO(2) and concentrations of NH(4)(+), NO(3)(-), NO(2)(-), phenanthrene and anthracene were monitored in an aerobic incubation experiment. Polyacrylamide in the sludge had no effect on the production of CO(2), but it reduced the concentration of NH(4)(+), increased the concentration of NO(3)(-) in the Acolman soil and NO(2)(-) in the Texcoco soil, and increased N mineralization compared to the soil amended with sludge without polyacrylamide. After 112d, polyacrylamide accelerated the removal of anthracene from both soils and that of phenanthrene in the Acolman soil. It was found that polyacrylamide accelerated removal of phenanthrene and anthracene from soil.

  17. Effect of bioaugmentation to enhance phytoremediation for removal of phenanthrene and pyrene from soil with Sorghum and Onobrychis sativa

    PubMed Central

    2014-01-01

    The use of plants to remove Poly-aromatic-hydrocarbons (PAHs) from soil (phytoremediation) is emerging as a cost-effective method. Phytoremediation of contaminated soils can be promoted by the use of adding microorganisms with the potential of pollution biodegradation (bioaugmentation). In the present work, the effect of bacterial consortium was studied on the capability of Sorghum and Onobrychis sativa for the phytoremediation of soils contaminated with phenanthrene and pyrene. 1.5 kg of the contaminated soil in the ratio of 100 and 300 mg phenanthrene and/or pyrene per kg of dry soil was then transferred into each pot (nine modes). The removal efficiency of natural, phytoremediation and bioaugmentation, separately and combined, were evaluated. The samples were kept under field conditions, and the remaining concentrations of pyrene and phenanthrene were determined after 120 days. The rhizosphere as well as the microbial population of the soil was also determined. Results indicated that both plants were able to significantly remove pyrene and phenanthrene from the contaminated soil samples. Phytoremediation alone had the removal efficiency of about 63% and 74.5% for pyrene and phenanthrene respectively. In the combined mode, the removal efficiency dramatically increased, leading to pyrene and phenanthrene removal efficiencies of 74.1% and 85.02% for Onobrychis sativa and 73.84% and 85.2% for sorghum, respectively. According to the results from the present work, it can be concluded that Onobrychis sativa and sorghum are both efficient in removing pyrene and phenanthrene from contamination and bioaugmentation can significantly enhance the phytoremediation of soils contaminated with pyrene and phenanthrene by 22% and 16% respectively. PMID:24406158

  18. Biodegradation of phenanthrene in bioaugmented microcosm by consortium ASP developed from coastal sediment of Alang-Sosiya ship breaking yard.

    PubMed

    Patel, Vilas; Patel, Janki; Madamwar, Datta

    2013-09-15

    A phenanthrene-degrading bacterial consortium (ASP) was developed using sediment from the Alang-Sosiya shipbreaking yard at Gujarat, India. 16S rRNA gene-based molecular analyses revealed that the bacterial consortium consisted of six bacterial strains: Bacillus sp. ASP1, Pseudomonas sp. ASP2, Stenotrophomonas maltophilia strain ASP3, Staphylococcus sp. ASP4, Geobacillus sp. ASP5 and Alcaligenes sp. ASP6. The consortium was able to degrade 300 ppm of phenanthrene and 1000 ppm of naphthalene within 120 h and 48 h, respectively. Tween 80 showed a positive effect on phenanthrene degradation. The consortium was able to consume maximum phenanthrene at the rate of 46 mg/h/l and degrade phenanthrene in the presence of other petroleum hydrocarbons. A microcosm study was conducted to test the consortium's bioremediation potential. Phenanthrene degradation increased from 61% to 94% in sediment bioaugmented with the consortium. Simultaneously, bacterial counts and dehydrogenase activities also increased in the bioaugmented sediment. These results suggest that microbial consortium bioaugmentation may be a promising technology for bioremediation.

  19. Effects of oil dispersant and oil on sorption and desorption of phenanthrene with Gulf Coast marine sediments.

    PubMed

    Gong, Yanyan; Zhao, Xiao; O'Reilly, S E; Qian, Tianwei; Zhao, Dongye

    2014-02-01

    Effects of a model oil dispersant (Corexit EC9500A) on sorption/desorption of phenanthrene were investigated with two marine sediments. Kinetic data revealed that the presence of the dispersant at 18 mg/L enhanced phenanthrene uptake by up to 7%, whereas the same dispersant during desorption reduced phenanthrene desorption by up to 5%. Sorption isotherms confirmed that at dispersant concentrations of 18 and 180 mg/L, phenanthrene uptake progressively increased for both sediments. Furthermore, the presence of the dispersant during desorption induced remarkable sorption hysteresis. The effects were attributed to added phenanthrene affinity and capacity due to sorption of the dispersant on the sediments. Dual-mode models adequately simulated sorption isotherms and kinetic data in the presence of the dispersant. Water accommodated oil (WAO) and dispersant-enhanced WAO increased phenanthrene sorption by up to 22%. This information is important for understanding roles of oil dispersants on the distribution and transport of petroleum PAHs in seawater-sediments. PMID:24291613

  20. Effects of the inoculant strain Sphingomonas paucimobilis 20006FA on soil bacterial community and biodegradation in phenanthrene-contaminated soil.

    PubMed

    Coppotelli, B M; Ibarrolaza, A; Del Panno, M T; Morelli, I S

    2008-02-01

    The effects of the inoculant strain Sphingomonas paucimobilis 20006FA (isolated from a phenanthrene-contaminated soil) on the dynamics and structure of microbial communities and phenanthrene elimination rate were studied in soil microcosms artificially contaminated with phenanthrene. The inoculant managed to be established from the first inoculation as it was evidenced by denaturing gradient gel electrophoresis analysis, increasing the number of cultivable heterotrophic and PAH-degrading cells and enhancing phenanthrene degradation. These effects were observed only during the inoculation period. Nevertheless, the soil biological activity (dehydrogenase activity and CO(2) production) showed a late increase. Whereas gradual and successive changes in bacterial community structures were caused by phenanthrene contamination, the inoculation provoked immediate, significant, and stable changes on soil bacterial community. In spite of the long-term establishment of the inoculated strain, at the end of the experiment, the bioaugmentation did not produce significant changes in the residual soil phenanthrene concentration and did not improve the residual effects on the microbial soil community.

  1. Low-valent niobium-mediated double activation of C-F/C-H bonds: fluorene synthesis from o-arylated alpha,alpha,alpha-trifluorotoluene derivatives.

    PubMed

    Fuchibe, Kohei; Akiyama, Takahiko

    2006-02-01

    By the treatment of 0.3 molar amount of NbCl5 and LiAlH4, o-arylated alpha,alpha,alpha-trifluorotoluenes afforded fluorene derivatives in good yields. C-F bonds of the CF3 group and the neighboring ortho C-H bond were doubly activated to give the coupling products. PMID:16448098

  2. Impact of activated carbon, biochar and compost on the desorption and mineralization of phenanthrene in soil.

    PubMed

    Marchal, Geoffrey; Smith, Kilian E C; Rein, Arno; Winding, Anne; Wollensen de Jonge, Lis; Trapp, Stefan; Karlson, Ulrich G

    2013-10-01

    Sorption of PAHs to carbonaceous soil amendments reduces their dissolved concentrations, limiting toxicity but also potentially biodegradation. Therefore, the maximum abiotic desorption of freshly sorbed phenanthrene (≤5 mg kg(-1)) was measured in three soils amended with activated carbon (AC), biochar or compost. Total amounts of phenanthrene desorbed were similar between the different soils, but the amendment type had a large influence. Complete desorption was observed in the unamended and compost amended soils, but this reduced for biochar (41% desorbed) and AC (8% desorbed). Cumulative amounts mineralized were 28% for the unamended control, 19% for compost, 13% for biochar and 4% for AC. Therefore, the effects of the amendments in soil in reducing desorption were also reflected in the extents of mineralization. Modeling was used to analyze key processes, indicating that for the AC and charcoal treatments bacterial activity did not limit mineralization, but rather desorption into the dissolved phase.

  3. Digestive determinants of benzo[a]pyrene and phenanthrene bioaccumulation by a deposit-feeding polychaete

    SciTech Connect

    Penry, D.L.; Weston, D.P.

    1998-11-01

    The uptake of hydrophobic contaminants from ingested sediment can contribute significantly to body burdens of deposit feeders, and feeding behavior and digestive physiology can play important roles in bioaccumulation. The authors examined the uptake of polycyclic aromatic hydrocarbons (PAHs) by the deposit-feeding polychaete Abarenicola pacifica in experiments in which worms were first acclimated to low or high organic carbon sediments with 0.08 or 0.45% total organic carbon, respectively and then transferred to low or high organic carbon test sediments contaminated with radiolabeled phenanthrene or benzo[a]pyrene. Ingestion rate was measurements are essential in many types of bioaccumulation studies because differences in ingestion rates between sediment types may confound some traditional measures of bioavailability. Physiological acclimation to the low or high organic carbon sediments did not appear to affect PAH uptake from the test sediments, but acclimation did affect biotransformation capabilities, particularly for phenanthrene.

  4. Degradation of Phenanthrene and Anthracene by Cell Suspensions of Mycobacterium sp. Strain PYR-1

    PubMed Central

    Moody, Joanna D.; Freeman, James P.; Doerge, Daniel R.; Cerniglia, Carl E.

    2001-01-01

    Cultures of Mycobacterium sp. strain PYR-1 were dosed with anthracene or phenanthrene and after 14 days of incubation had degraded 92 and 90% of the added anthracene and phenanthrene, respectively. The metabolites were extracted and identified by UV-visible light absorption, high-pressure liquid chromatography retention times, mass spectrometry, 1H and 13C nuclear magnetic resonance spectrometry, and comparison to authentic compounds and literature data. Neutral-pH ethyl acetate extracts from anthracene-incubated cells showed four metabolites, identified as cis-1,2-dihydroxy-1,2-dihydroanthracene, 6,7-benzocoumarin, 1-methoxy-2-hydroxyanthracene, and 9,10-anthraquinone. A novel anthracene ring fission product was isolated from acidified culture media and was identified as 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid. 6,7-Benzocoumarin was also found in that extract. When Mycobacterium sp. strain PYR-1 was grown in the presence of phenanthrene, three neutral metabolites were identified as cis- and trans-9,10-dihydroxy-9,10-dihydrophenanthrene and cis-3,4-dihydroxy-3,4-dihydrophenanthrene. Phenanthrene ring fission products, isolated from acid extracts, were identified as 2,2′-diphenic acid, 1-hydroxynaphthoic acid, and phthalic acid. The data point to the existence, next to already known routes for both gram-negative and gram-positive bacteria, of alternative pathways that might be due to the presence of different dioxygenases or to a relaxed specificity of the same dioxygenase for initial attack on polycyclic aromatic hydrocarbons. PMID:11282593

  5. Mechanistic characterization of adsorption and slow desorption of phenanthrene aged in soils

    SciTech Connect

    Abdul Abu; Steve Smith

    2006-09-01

    Long-term adsorption of phenanthrene to soils was characterized in a silt-loam (LHS), a sandy soil (SBS) from an uncontaminated area of a former coal treatment facility in the north of England and a podzolized soil (CNS) by use of the Polanyi-Manes model, a Langmuir-type model, and a black carbon-water distribution coefficient (K{sub BC}) at a relative aqueous concentration (C{sub e}/S{sub w}) of 0.002 - 0.32. Aqueous desorption kinetic tests and temperature-programmed desorption (TPD) were also used to evaluate phenanthrene diffusivities and desorption activation energies. Adsorption contribution in soils was 48-70% after 30 days and 64-95% after 270 days. Significant increases in adsorption capacity with aging suggest that accessibility of phenanthrene to fractions of SBS soil matrix was controlled by sorptive diffusion at narrow meso- and micropore constrictions. Similar trends were not significant for LHS silt-loam or CNS podzol. Analysis of TPD profiles reveal desorption activation energies of 35-53 kJ/mol and diffusivities of 1.6 x 10{sup -7-}9.7 10{sup -8} cm{sup 2}/s. TPD tests also indicate that the fraction of phenanthrene mass not diffusing from soils was located within micropores and narrow width mesopores with a corresponding volume of 1.83 10{sup -5-}6.3710{sup -5} cm{sup 3}/g. These values were consistent with the modeled adsorption contributions, thus demonstrating the need for such complimentary analytical approach in the risk assessment of organic contaminants. 41 refs., 2 figs., 4 tabs.

  6. Transcriptomics reveals extensive inducible biotransformation in the soil-dwelling invertebrate Folsomia candida exposed to phenanthrene

    PubMed Central

    Nota, Benjamin; Bosse, Mirte; Ylstra, Bauke; van Straalen, Nico M; Roelofs, Dick

    2009-01-01

    Background Polycyclic aromatic hydrocarbons are common pollutants in soil, have negative effects on soil ecosystems, and are potentially carcinogenic. The Springtail (Collembola) Folsomia candida is often used as an indicator species for soil toxicity. Here we report a toxicogenomic study that translates the ecological effects of the polycyclic aromatic hydrocarbon phenanthrene in soil to the early transcriptomic responses in Folsomia candida. Results Microarrays were used to examine two different exposure concentrations of phenanthrene, namely the EC10 (24.95 mg kg-1 soil) and EC50 (45.80 mg kg-1 soil) on reproduction of this springtail, which evoked 405 and 251 differentially expressed transcripts, respectively. Fifty transcripts were differential in response to either concentration. Many transcripts encoding xenobiotic detoxification and biotransformation enzymes (phases I, II, and III) were upregulated in response to either concentration. Furthermore, indications of general and oxidative stress were found in response to phenanthrene. Chitin metabolism appeared to be disrupted particularly at the low concentration, and protein translation appeared suppressed at the high concentration of phenanthrene; most likely in order to reallocate energy budgets for the detoxification process. Finally, an immune response was evoked especially in response to the high effect concentration, which was also described in a previous transcriptomic study using the same effect concentration (EC50) of cadmium. Conclusion Our study provides new insights in the molecular mode of action of the important polluting class of polycyclic aromatic hydrocarbons in soil animals. Furthermore, we present a fast, sensitive, and specific soil toxicity test which enhances traditional tests and may help to improve current environmental risk assessments and monitoring of potentially polluted sites. PMID:19457238

  7. trans-Chlorido(phenanthren-9-yl)bis­(triphenyl­phosphane)nickel(II)

    PubMed Central

    Lei, Xiangyang; Obregon, Karla A.

    2011-01-01

    The title compound, [Ni(C14H9)Cl(C18H15P)2], was synthesized from the reaction between 9-chloro­phenanthrene, NiCl2·6H2O and triphenyl­phosphane in ethanol. The bond angles around the NiII atom indicate that it exists in a slightly distorted square-planar geometry. PMID:22058872

  8. Molecular topology tuning of bipolar host materials composed of fluorene-bridged benzimidazole and carbazole for highly efficient electrophosphorescence.

    PubMed

    Mondal, Ejabul; Hung, Wen-Yi; Chen, Yang-Huei; Cheng, Ming-Hung; Wong, Ken-Tsung

    2013-08-01

    Two new molecules, CzFCBI and CzFNBI, have been tailor-made to serve as bipolar host materials to realize high-efficiency electrophosphorescent devices. The molecular design is configured with carbazole as the hole-transporting block and N-phenylbenzimidazole as the electron-transporting block hybridized through the saturated bridge center (C9) and meta-conjugation site (C3) of fluorene, respectively. With structural topology tuning of the connecting manner between N-phenylbenzimidazole and the fluorene core, the resulting physical properties can be subtly modulated. Bipolar host CzFCBI with a C connectivity between phenylbenzimidazole and the fluorene bridge exhibited extended π conjugation; therefore, a low triplet energy of 2.52 eV was observed, which is insufficient to confine blue phosphorescence. However, the monochromatic devices indicate that the matched energy-level alignment allows CzFCBI to outperform its N-connected counterpart CzFNBI while employing other long-wavelength-emitting phosphorescent guests. In contrast, the high triplet energy (2.72 eV) of CzFNBI imparted by the N connectivity ensures its utilization as a universal bipolar host for blue-to-red phosphors. With a common device configuration, CzFNBI has been utilized to achieve highly efficient and low-roll-off devices with external quantum efficiency as high as 14 % blue, 17.8 % green, 16.6 % yellowish-green, 19.5 % yellow, and 18.6 % red. In addition, by combining yellowish-green with a sky-blue emitter and a red emitter, a CzFNBI-hosted single-emitting-layer all-phosphor three-color-based white electrophosphorescent device was successfully achieved with high efficiencies (18.4 %, 36.3 cd A(-1) , 28.3 lm W(-1) ) and highly stable chromaticity (CIE x=0.43-0.46 and CIE y=0.43) at an applied voltage of 8 to 12 V, and a high color-rendering index of 91.6.

  9. Rhizodegradation potential and tolerance of Avicennia marina (Forsk.) Vierh in phenanthrene and pyrene contaminated sediments.

    PubMed

    Jia, Hui; Wang, He; Lu, Haoliang; Jiang, Shan; Dai, Minyue; Liu, Jingchun; Yan, Chongling

    2016-09-15

    A pot experiment was conducted to investigate the dissipation of phenanthrene and pyrene in spiked sediments with presence of Avicennia marina (Forsk.) Vierh. The rhizosphere environment was set up using a self-design nylon rhizo-bag which divided the sediment into the rhizosphere and non-rhizosphere. Results showed that the dissipation of phenanthrene and pyrene were significantly enhanced in the rhizosphere compared with non-rhizosphere sediments. Plant roots promoted dissipation significantly greater than the contribution of direct plant uptake and accumulation of phenanthrene and pyrene. The activities of antioxidant and detoxification enzymes in roots and leaves significantly increased against oxidative stress with increasing PAH concentrations. Furthermore, a significant relationship (R(2)>0.91) between dissolved organic carbon (DOC) concentrations and the residual of PAHs in rhizosphere and non-rhizosphere sediments was observed after 120days planting. Results indicated that rhizome mediation with A. marina is a useful approach to promote the depletion of PAHs in contaminated mangrove sediments. PMID:27373941

  10. Influence of temperature on phenanthrene toxicity towards nitrifying bacteria in three soils with different properties.

    PubMed

    Suszek-Łopatka, Beata; Maliszewska-Kordybach, Barbara; Klimkowicz-Pawlas, Agnieszka; Smreczak, Bożena

    2016-09-01

    This study focused on the combined effect of environmental conditions (temperature) and contamination (polycyclic aromatic hydrocarbons, PAHs) on the activity of soil microorganisms (nitrifying bacteria). Phenanthrene (Phe) at five contamination levels (0, 1, 10, 100 and 1000 mg kg(-1) dry mass of soil) was employed as a model PAH compound in laboratory experiments that were conducted at three temperatures (i.e., 20 °C (recommended by ISO 15685 method), 15 and 30 °C). Three soils with different properties were used in these studies, and the activity of the nitrifying bacteria was assessed based on nitrification potential (NP) determinations. For the statistical evaluation of the results, the ANCOVA (analysis of covariance) method for three independent variables (i.e., temperature, phenanthrene concentration, soil matrix (as a qualitative variable)) and their interactions was employed. The results indicated on the significant interaction of all studied factors. Temperature influenced the toxicity of Phe towards NP, and this effect was related to the Phe concentration as well as was varied for the different soils. A low content of soil organic matter (controlling bioavailability of phenanthrene to soil microorganisms) enhanced the combined effect of temperature and Phe toxicity, and a high biological activity of the soil (high NP values) increased the effect of high temperature on the Phe stimulatory influence. The results indicate that the temperature should not be neglected in tests evaluating PAH ecotoxicity, especially for reliable ecological risk assessment. PMID:27394082

  11. [Isolation of two endophytic phenanthrene-degrading strains and their degradation capacity].

    PubMed

    Ni, Xue; Liu, Juan; Gao, Yan-Zheng; Zhu, Xue-Zhu; Sun, Kai

    2013-02-01

    Two endophytic bacterial strains, which could degrade high concentration (up to 200 mg.L-1) of phenanthrene in liquid, were isolated from plants grown in PAHs-contaminated soils by the selective. enrichment culture. According to the results of morphology, physiology and the phylogenetic analyses of 16S rDNA sequence, stain P1 was identified as Stenotrophomonas sp. , and strain P3 was identified as Pseudomonas sp.. Two strains were aerobic bacteria, the degradation rates of phenanthrene (100 mg.L-1) by strain P1 and strain P3 were all greater than 90% at 28 degrees C on the rotation shaker at 150 r.min-1 for 7 days. The degradation rates of phenanthrene by two strains were greater than 70% when cultivated under the conditions as: 20-30 degrees C , pH 6-8, 0%-4% NaCl, 10-30 mL/100 mL inventory. It suggested that the optimum culture condition was: 30 degrees C, pH 7.0, NaCl< or =4% , inventory < or = 30 mL/100 mL flask. Through comprehensive comparison analyses on the degradation capacity of two strains, it showed that the tolerance of strain P1 to high temperature was higher than that of str ain P3, while the tolerance of strain P3 to pH change and anoxic condition was higher than that of strain P1. PMID:23668150

  12. Surface tailored organobentonite enhances bacterial proliferation and phenanthrene biodegradation under cadmium co-contamination.

    PubMed

    Mandal, Asit; Biswas, Bhabananda; Sarkar, Binoy; Patra, Ashok K; Naidu, Ravi

    2016-04-15

    Co-contamination of soil and water with polycyclic aromatic hydrocarbon (PAH) and heavy metals makes biodegradation of the former extremely challenging. Modified clay-modulated microbial degradation provides a novel insight in addressing this issue. This study was conducted to evaluate the growth and phenanthrene degradation performance of Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30mgL(-1) metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10mgL(-1)), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72-78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP-bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil.

  13. Synthesis and antioxidant activity of hydroxylated phenanthrenes as cis-restricted resveratrol analogues.

    PubMed

    Ding, De-Jun; Cao, Xiao-Yan; Dai, Fang; Li, Xiu-Zhuang; Liu, Guo-Yun; Lin, Dong; Fu, Xing; Jin, Xiao-Ling; Zhou, Bo

    2012-12-01

    Five hydroxylated phenanthrenes as "cis-configuration-fixed" resveratrol analogues differing in the number and position of the hydroxyl groups were designed and synthesized. Their antioxidant activity was studied by ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging, and DNA strand breakage-inhibiting assays, corresponding to their electron-donating, hydrogen-transfer and DNA-protecting abilities, respectively. In the above assays, their activity depends significantly on the number and position of the hydroxyl groups, and most of them are more effective than resveratrol. Noticeably, compound 9b (2,4,6-trihydroxyl phenanthrene) with the same hydroxyl group substitutions as resveratrol, is superior to the reference compound, highlighting the importance of extension of the conjugation over multiple aromatic-rings. Similar activity sequences were obtained in different experimental models, but the appreciable differences could contribute detailed insights into antioxidant mechanisms. Based on these results, the hydroxylated phenanthrenes may be considered as a novel type of resveratrol-directed antioxidants.

  14. Electroremediation of a natural soil polluted with phenanthrene in a pilot plant.

    PubMed

    López-Vizcaíno, R; Alonso, J; Cañizares, P; León, M J; Navarro, V; Rodrigo, M A; Sáez, C

    2014-01-30

    In this work, a pilot plant with two rows of three electrodes in semipermeable electrolyte wells was used to study the electrokinetic treatment of a natural soil polluted with phenanthrene (PHE). The electrokinetic pilot plant was an open system, i.e., there was direct contact between the soil and air. To increase the solubility of phenanthrene, thereby enhancing its transport through the soil, an aqueous solution of the anionic surfactant dodecyl sulfate was used as a flushing fluid. The results show that at the pilot scale considered, gravity and evaporation fluxes are more relevant than electrokinetic fluxes. Contrary to observations at the laboratory scale, desorption of PHE promoted by electric heating appears to be a significant removal mechanism at the pilot scale. In addition, PHE is dragged by the electroosmotic flow in the cathodic wells and by electrophoresis after interaction of the surfactant with phenanthrene in the anodic wells. In spite of the long treatment time (corresponding to an energy consumption over 500kWhm(-3)), the average removal attained was only 25%. PMID:24361491

  15. The efficacy of an oxidation pond in mineralizing some industrial waste products with special reference to fluorene degradation: A case study

    SciTech Connect

    Ahmed, M.T.; Dewedar, A.; Mekki, L.; Diab, A.

    1999-07-01

    The efficacy of the oxidation pond on the outskirts of the 10th of Ramadan, the main industrial city in Egypt, was examined. Samples of wastewater collected from the inlet and the outlet were screened for some priority pollutants. Acenaphethene and fluorene were the most frequently detected polycyclic aromatic hydrocarbons, while dimethyl phthalate was the most frequently detected phthalate ester. The spectrum of pollutants, their concentrations and frequencies were similar in the inlet and the outlet, indicating an inferior mineralization capability of the pond. Several degradative bacterial strains were isolated from the pond and grown on M56 minimal media supplemented with different pollutants as the carbon source. The efficacy of pure and mixed cultures to break down fluorene, the most frequently detected pollutant was examined. Fluorene degradation was fast in the first 10 days, the followed by a slow phase. Mixed culture had a higher rate of fluorene degradation in comparison to pure cultures. High performance liquid chromatography analysis of fluorene degradation showed three degradative metabolites. But GC/MS analysis detected one compound, identified as acetamide. The present work has indicated the poor efficacy of the pond. Lack of primary treatment of industrial effluent at factory level, coupled with shock loads of toxicants that may damage the microorganisms and their degradative capabilities are presumably main factors behind such inferior performance. Moreover, the type of pollutants discharged into the pond tend to fluctuate and change depending on the rate from the factories discharge and work shifts. Such irregular feeding of persistent pollutants may have led to a wash out of specialized strains of bacteria capable to degrade such persistent pollutants.

  16. Role of microbial adhesion in phenanthrene biodegradation by Pseudomonas fluorescens LP6a

    NASA Astrophysics Data System (ADS)

    Abbasnezhad, Hassan

    Biodegradation of poorly water soluble hydrocarbons, such as n-alkanes and polycyclic aromatic hydrocarbons (PAHs) is often limited by the low availability of the pollutant to microbes. Adhesion of microorganisms to the oil-water interface can influence this availability. Our approach was to study a range of compounds and mechanisms to promote the adhesion of a hydrophilic PAH degrading bacterium, Pseudomonas fluorescens LP6a, to an oil-water interface and examine the effect on biodegradation of phenanthrene by the bacteria. The cationic surfactants cetylpyridinium chloride (CPC), poly-L-lysine and chlorhexidine gluconate (CHX) and the long chain alcohols 1-dodecanol, 2-dodecanol and farnesol increased the adhesion of P. fluorescens LP6a to n-hexadecane from ca. 30% to ca. 90% of suspended cells adhering. The alcohols also caused a dramatic change in the oil-water contact angle of the cell surface, increasing it from 24° to 104°, whereas the cationic compounds had little effect. In contrast, cationic compounds changed the electrophoretic mobility of the bacteria, reducing the mean zeta potential from --23 to --7 mV in 0.01M potassium phosphate buffer, but the alcohols had no effect on zeta potential. This results illustrate that alcohols acted through altering the cell surface hydrophobicity, whereas cationic surfactants changed the surface charge density. Phenanthrene was dissolved in heptamethylnonane and introduced to the aqueous growth medium, hence forming a two phase system. Introducing 1-dodecanol at concentrations of 217, 820 or 4100 mg/L resulted in comparable increases in phenanthrene biodegradation of about 30% after 120 h incubation with non-induced cultures. After 100 h of incubation with LP6a cultures induced with 2-aminobenzoate, 4.5% of the phenanthrene was mineralized by cultures versus more than 10% by the cultures containing initial 1-dodecanol or 2-dodecanol concentrations of 120 or 160 mg/L. The production and accumulation of metabolites in

  17. A solution processable fluorene-benzothiadiazole small molecule for n-type organic field-effect transistors

    NASA Astrophysics Data System (ADS)

    Mutkins, Karyn; Gui, Ke; Aljada, Muhsen; Schwenn, Paul E.; Namdas, Ebinazar B.; Burn, Paul L.; Meredith, Paul

    2011-04-01

    We report an n-type organic semiconductor [2-({7-(9,9-di-n-propyl-9H-fluoren-2-yl}benzo[c][1,2,5]thiadiazol-4-yl)methylene]malononitrile (herein referred to as K12) for use in organic field-effect transistors (OFETs). K12 can be processed by spin-coating from solution or by vacuum deposition, organizing into highly orientated microcrystalline structures at modest (75 °C) annealing temperatures. OFETs with n-octyltrichlorosilane or hexamethyldisilazane monolayers, or poly(propylene-co-1-butene) (PPCB) modified dielectric surfaces were prepared. The mobility, ON/OFF ratio, threshold voltage, and current hysteresis were found to be dependent on the thermal history of the film and surface onto which it was deposited. The highest OFET mobility achieved was 2.4×10-3 cm2/V s, for spin-coated films with a PPCB modified silicon dioxide dielectric.

  18. Voltammetric detection of damage to DNA caused by nitro derivatives of fluorene using an electrochemical DNA biosensor.

    PubMed

    Vyskocil, Vlastimil; Labuda, Ján; Barek, Jirí

    2010-05-01

    An electrochemical DNA biosensor based on the screen printed carbon paste electrode (SPCPE) with an immobilized layer of calf thymus double-stranded DNA has been used for in vitro investigation of the interaction between genotoxic nitro derivatives of fluorene (namely 2-nitrofluorene and 2,7-dinitrofluorene) and DNA. Two types of DNA damage have been detected at the DNA/SPCPE biosensor: first, that caused by direct association of the nitrofluorenes, for which an intercalation association has been found using the known DNA intercalators [Cu(phen)(2)](2+) and [Co(phen)(3)](3+) as competing agents, and, second, that caused by short-lived radicals generated by electrochemical reduction of the nitro group (observable under specific conditions only). PMID:20186538

  19. Trinuclear nickel coordination complexes of phenanthrene-9,10-dione dioxime

    PubMed Central

    Williams, Owen M.; Cowley, Alan H.

    2016-01-01

    A trinuclear nickel complex of phenanthrene-9,10-dione dioxime (H2pqd), namely bis­[μ2-9,10-bis­(oxido­imino)­phenanthrene]­bis­[μ2-10-(oxido­imino)phenanthrene-9-one oxime](phenanthrene-9,10-dione dioxime)trinickel(II) toluene disolvate, [Ni3(C14H8N2O2)2(C14H9N2O2)2(C14H10N2O2)]·2C7H8, has been isolated and its crystal structure determined. This complex features three independent NiII atoms that are arranged in a triangular fashion along with five supporting ligands. There are two square-planar NiII atoms and a third pseudo-octa­hedral NiII atom. While the square-planar NiII atoms are stacked, there are no ligand bridges between them. Each square-planar NiII atom, however, bridges with the pseudo-octa­­hedral NiII atom through Ni—N—O—Ni and Ni—O—Ni bonds. A fluorido­bor­ation reaction of the proton-bridged species gave the analogous complex bis­(μ2-bis­{[10-(oxido­imino)-9,10-di­hydro­phenanthren-9-yl­idene]amino}di­fluorido­borato)(phenanthrene-9,10-dione dioxime)trinickel(II) dichloromethane trisolvate, [Ni3(C28H16BF2N4O2)4(C14H10N2O2)]·3CH2Cl2, which shows the same binding structure, but features a widened Ni—Ni inter­action between the square-planar NiII atoms. The proton-bridged complex completes the macrocyclic coordination around the square-planar NiII atoms by means of an O—H⋯O hydrogen bond. Both compounds feature O—H⋯N hydrogen bonds between the oxime and the N atoms attached to square-planar nickel atom. The nickel units show no direct inter­action with their nearest neighbors in the extended lattice. Two π-stacking inter­actions between adjacent mol­ecules are found: one with a centroid–centroid distance of 3.886 (2) Å and the other with a centroid–centroid distance of 4.256 (3) Å. In the latter case, although not aromatic, the distance to the centroid of the central phenanthrene ring is shorter, with a distance of 3.528 (3) Å. Toluene mol­ecules occupy the solvent channels that are

  20. Trinuclear nickel coordination complexes of phenanthrene-9,10-dione dioxime.

    PubMed

    Williams, Owen M; Cowley, Alan H

    2016-04-01

    A trinuclear nickel complex of phenanthrene-9,10-dione dioxime (H2pqd), namely bis-[μ2-9,10-bis-(oxido-imino)-phenanthrene]-bis-[μ2-10-(oxido-imino)phenanthrene-9-one oxime](phenanthrene-9,10-dione dioxime)trinickel(II) toluene disolvate, [Ni3(C14H8N2O2)2(C14H9N2O2)2(C14H10N2O2)]·2C7H8, has been isolated and its crystal structure determined. This complex features three independent Ni(II) atoms that are arranged in a triangular fashion along with five supporting ligands. There are two square-planar Ni(II) atoms and a third pseudo-octa-hedral Ni(II) atom. While the square-planar Ni(II) atoms are stacked, there are no ligand bridges between them. Each square-planar Ni(II) atom, however, bridges with the pseudo-octa--hedral Ni(II) atom through Ni-N-O-Ni and Ni-O-Ni bonds. A fluorido-bor-ation reaction of the proton-bridged species gave the analogous complex bis-(μ2-bis-{[10-(oxido-imino)-9,10-di-hydro-phenanthren-9-yl-idene]amino}di-fluorido-borato)(phenanthrene-9,10-dione dioxime)trinickel(II) dichloromethane trisolvate, [Ni3(C28H16BF2N4O2)4(C14H10N2O2)]·3CH2Cl2, which shows the same binding structure, but features a widened Ni-Ni inter-action between the square-planar Ni(II) atoms. The proton-bridged complex completes the macrocyclic coordination around the square-planar Ni(II) atoms by means of an O-H⋯O hydrogen bond. Both compounds feature O-H⋯N hydrogen bonds between the oxime and the N atoms attached to square-planar nickel atom. The nickel units show no direct inter-action with their nearest neighbors in the extended lattice. Two π-stacking inter-actions between adjacent mol-ecules are found: one with a centroid-centroid distance of 3.886 (2) Å and the other with a centroid-centroid distance of 4.256 (3) Å. In the latter case, although not aromatic, the distance to the centroid of the central phenanthrene ring is shorter, with a distance of 3.528 (3) Å. Toluene mol-ecules occupy the solvent channels that are oriented along the c axis. In

  1. Bioconcentration of phenanthrene and metabolites in bile and behavioral alterations in the tropical estuarine guppy Poecilia vivipara.

    PubMed

    Torreiro-Melo, Anny Gabrielle A G; Silva, Juliana Scanoni; Bianchini, Adalto; Zanardi-Lamardo, Eliete; de Carvalho, Paulo Sérgio Martins

    2015-08-01

    Quantification of polycyclic aromatic hydrocarbon (PAH) metabolites in fish bile is widely used to evaluate levels of internal PAH contamination in fish, whereas behavioral effects are deemed important to address potential risks to fish populations. The estuarine guppy Poecilia vivipara was exposed for 96h to waterborne phenanthrene at concentrations of 10, 50, 200 and 500μgL(-1). Phenanthrene and metabolites in bile were analyzed by fixed fluorescence at 260/380nm (excitation/emission) wavelengths. Phenanthrene increased in the bile of exposed fish in a dose-dependent pattern, and log bile bioconcentration factors ranged from 4.3 to 3.9 at 10 and 500μgL(-1) phenanthrene, respectively, values that are similar to predicted bioconcentration factors based on phenanthrene Kow. Swimming resistance index was reduced to 81% of control values at 500μgL(-1). Alteration of swimming speed was non monotonic, with a significant speed increase relative to control fish in treatments 50 and 200μgL(-1) phenanthrene, respectively, followed by a speed decrease in fish exposed to 500μgL(-1). However, swimming trajectories of fish exposed to 50, 200 and 500μgL(-1) was altered by the development of a repetitive circular swimming behavior, in contrast to the controls that explored the entire experimental arena. This change in swimming patterns apparently explains the reduction in prey capture rates at 200μgL(-1) phenanthrene. This study provides important information enabling the use of the estuarine guppy P. vivipara to monitor PAH metabolites in bile and its bioconcentration, linking internal exposure with ecologically relevant behavioral effects in the species.

  2. Measurements of NO/sub 2/, HONO, NO/sub 3/, NCHO, PAH, nitroarenes, and particulate mutagenic activities during the carbonaceous-species-methods comparison study. Final report, 9 July 1986-30 July 1987

    SciTech Connect

    Atkinson, R.; Winer, A.M.

    1988-02-01

    The ambient concentrations of NO/sub 2/, HONO and HCHO were measured by long-pathlength differential optical absorption spectroscopy. Ambient concentrations of HNO/sub 3/, NH/sub 3/ and HCHO were measured by long-pathlength Fourier infrared-absorption spectroscopy. Significant concentrations of these pollutants were observed. Ambient air samples were analyzed for mutagenicity and gas- and particle-associated polycyclic aromatic hydrocarbons (PAH) and nitroarenes. The mutagen densities obtained were consistent with those measured previously in the South Coast Air Basin. The following PAH and nitroarenes were observed and quantified: naphthalene, 1- and 2-methylnaphthalene, biphenyl, acenaphthene, acenaphthylene, fluorene, phenanthrene, anthracene, dibenzothiophene, fluoranthene, pyrene, benz(a)anthracene, chrysene/triphenylene, benzo(a)pyrene, 1- and 2-nitronaphthalene, 3-nitrobiphenyl, 2-, 3- and 8-nitrofluoranthrene, and 1- and 2-nitropyrene.

  3. Toxicological profile for polycyclic aromatic hydrocarbons. Final report

    SciTech Connect

    Not Available

    1990-12-01

    The ATSDR Toxicological Profile for Polycyclic Aromatic Hydrocarbons (PAHs): Acenaphthene, Acenaphthylene, Anthracene, Benzo(a)anthracene, Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(g,h,i)perylene, Benzo(k)fluoranthene, Chrysene, Dibenzo(a,h)anthracene, Fluoranthene, Fluorene, Indeno(1,2,3-cd)pyrene, Phenanthrene, Pyrene is intended to characterize succinctly the toxicological and health effects information for the substance. It identifies and reviews the key literature that describes the substance's toxicological properties. Other literature is presented but described in less detail. The profile begins with a public health statement, which describes in nontechnical language the substance's relevant toxicological properties. The adequacy of information to determine the substance's health effects is described. Research gaps in nontoxic and health effects information are described. Research gaps that are of significance to the protection of public health will be identified in a separate effort. The focus of the document is on health and toxicological information.

  4. Polycyclic aromatic hydrocarbon removal from water by natural fiber sorption.

    PubMed

    Khan, Eakalak; Khaodhir, Sutha; Rotwiron, Paritta

    2007-08-01

    The use of two natural sorbents, kapok and cattail fibers, were investigated for polycyclic aromatic hydrocarbon (PAH) removal from water. Naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, and fluoranthene were the PAHs studied. For comparative purposes, a commercial polyester fiber sorbent was included in the investigation. The PAH sorption and retention capabilities of the three fibers were determined through batch and continuous-flow experiments under non-competitive and competitive conditions. In the batch experiments, cattail fiber was the most effective sorbent. Kapok fiber provided the lowest PAH retention, while cattail fiber had slightly less PAH retention than polyester fiber. When two PAHs were present in the same system, a competitive effect on the much less hydrophobic PAH was observed. Similar results were obtained in the column experiments, except that polyester fiber performed much poorer on naphthalene. Cattail fiber is a promising sorbent for treating PAH-contaminated water, such as urban runoff.

  5. Atmospheric concentrations and dry deposition rates of polycyclic aromatic hydrocarbons (PAHs) for Tampa Bay, Florida, USA

    NASA Astrophysics Data System (ADS)

    Poor, Noreen; Tremblay, Raphael; Kay, Heidi; Bhethanabotla, Venkat; Swartz, Erick; Luther, Mark; Campbell, Scott

    2004-11-01

    Sampling of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) at the Gandy Bridge monitoring site between May and August 2002 provided preliminary ambient air concentrations and dry deposition rates for Tampa Bay. The HiC-IOGAPS dramatically improved the recovery of lower molecular weight gas and particle PAHs, as evidenced by the recoveries of PAHs in back-up denuders and filter packs. Total PAH (gas+particle) concentrations ranged from 80 to 190 ng m-3. Concentrations of naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene, and pyrene were consistently higher than concentrations of the remaining 10 PAHs. Assuming an unidirectional flux of these compounds from air to water, the estimated total (gas+particle) dry deposition flux was 11.5 μg m-2 d-1, or 6.7 μg m-2 d-1 if naphthalene is excluded.

  6. Quantifying the biodegradation of phenanthrene by Pseudomonas stutzeri P16 in the presence of a nonionic surfactant.

    PubMed Central

    Grimberg, S J; Stringfellow, W T; Aitken, M D

    1996-01-01

    The low water solubility of polycyclic aromatic hydrocarbons is believed to limit their availability to microorganisms, which is a potential problem for bioremediation of polycyclic aromatic hydrocarbon-contaminated sites. Surfactants have been suggested to enhance the bioavailability of hydrophobic compounds, but both negative and positive effects of surfactants on biodegradation have been reported in the literature. Earlier, we presented mechanistic models of the effects of surfactants on phenanthrene dissolution and on the biodegradation kinetics of phenanthrene solubilized in surfactant micelles. In this study, we combined the biodegradation and dissolution models to quantify the influence of the surfactant Tergitol NP-10 on biodegradation of solid-phase phenanthrene by Pseudomonas stutzeri P16. Although micellized phenanthrene does not appear to be available directly to the bacterium, the ability of the surfactant to increase the phenanthrene dissolution rate resulted in an overall increase in bacterial growth rate in the presence of the surfactant. Experimental observations could be predicted well by the derived model with measured biokinetic and dissolution parameters. The proposed model therefore can serve as a base case for understanding the physical-chemical effects of surfactants on nonaqueous hydrocarbon bioavailability. PMID:8779577

  7. Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

    NASA Astrophysics Data System (ADS)

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

    2014-06-01

    This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg.L-1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination.

  8. Isolation and characterization of a novel phenanthrene (PHE) degrading strain Psuedomonas sp. USTB-RU from petroleum contaminated soil.

    PubMed

    Masakorala, Kanaji; Yao, Jun; Cai, Minmin; Chandankere, Radhika; Yuan, Haiyan; Chen, Huilun

    2013-12-15

    The phenanthrene degrading novel bacterium strain USTB-RU was isolated from petroleum contaminated soil in Dagan oilfield, southeast of Tianjin, northeast China. The novel isolate was identified as Pseudomonas sp. USTB-RU on the basis of morphological, physicochemical characteristics and analysis of 16S rDNA gene sequence. The strain could degrade 86.65% of phenanthrene at an initial concentration of 100 mg L(-1) in 8 days and identified intermediate metabolite evident the biodegradation of phenanthrene through protocatechuate metabolic pathway. The strain showed the potential to produce surface-active compounds that may have caused for the resulted efficient biodegradation through enhancing the substrate bioavailability. The results highlighted that the adaptability of USTB-RU to grow in a range of temperature, pH and potential to utilize various commonly co-exist pollutants in contaminated site other than phenanthrene as sole carbon and energy source. Further, susceptibility of the strain for the tested antibiotics inferred the possibility to absence of risk of spreading drug resistant factor to other indigenous bacteria. Therefore, the isolated novel strain USTB-RU may have a high potential for application in in situ bioremediation of phenanthrene contaminated environment. PMID:24225588

  9. An experimental and theoretical investigation of Acenaphthene-5-boronic acid: conformational study, NBO and NLO analysis, molecular structure and FT-IR, FT-Raman, NMR and UV spectra.

    PubMed

    Karabacak, Mehmet; Sinha, Leena; Prasad, Onkar; Asiri, Abdullah M; Cinar, Mehmet

    2013-11-01

    The solid state Fourier transform infrared (FT-IR) and FT-Raman spectra of Acenaphthene-5-boronic acid (AN-5-BA), have been recorded in the range 4000-400cm(-1) and 4000-10cm(-1), respectively. Density functional theory (DFT), with the B3LYP functional was used for the optimization of the ground state geometry and simulation of the infrared and Raman spectra of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes and the normal modes were assigned by a scaled quantum mechanical (SQM) force field approach. Hydrogen-bonded dimer of AN-5-BA, optimized by counterpoise correction, has also been studied by B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H⋯O hydrogen bonding have been discussed. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by Gauge-Including Atomic Orbital (GIAO) method. Natural bond orbital (NBO) analysis has been applied to study stability of the molecule arising from charge delocalization. UV spectrum of the title compound was also recorded and the electronic properties, such as frontier orbitals, and band gap energies were measured by TD-DFT approach. The first order hyperpolarizability 〈β〉, its components and associated properties such as average polarizability and anisotropy of the polarizability (α and Δα) of AN-5-BA was calculated using the finite-field approach. PMID:23892116

  10. An experimental and theoretical investigation of Acenaphthene-5-boronic acid: Conformational study, NBO and NLO analysis, molecular structure and FT-IR, FT-Raman, NMR and UV spectra

    NASA Astrophysics Data System (ADS)

    Karabacak, Mehmet; Sinha, Leena; Prasad, Onkar; Asiri, Abdullah M.; Cinar, Mehmet

    2013-11-01

    The solid state Fourier transform infrared (FT-IR) and FT-Raman spectra of Acenaphthene-5-boronic acid (AN-5-BA), have been recorded in the range 4000-400 cm-1 and 4000-10 cm-1, respectively. Density functional theory (DFT), with the B3LYP functional was used for the optimization of the ground state geometry and simulation of the infrared and Raman spectra of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes and the normal modes were assigned by a scaled quantum mechanical (SQM) force field approach. Hydrogen-bonded dimer of AN-5-BA, optimized by counterpoise correction, has also been studied by B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H⋯O hydrogen bonding have been discussed. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by Gauge-Including Atomic Orbital (GIAO) method. Natural bond orbital (NBO) analysis has been applied to study stability of the molecule arising from charge delocalization. UV spectrum of the title compound was also recorded and the electronic properties, such as frontier orbitals, and band gap energies were measured by TD-DFT approach. The first order hyperpolarizability <β>, its components and associated properties such as average polarizability and anisotropy of the polarizability (α and Δα) of AN-5-BA was calculated using the finite-field approach.

  11. Recovery of Phenanthrene-Degrading Bacteria After Simulated In Situ Persulfate Oxidation in Contaminated Soil

    PubMed Central

    Richardson, Stephen D.; Lebron, Benjamin L.; Miller, Cass T.; Aitken, Michael D.

    2010-01-01

    A continuous-flow column study was conducted to investigate the long-term effects of persulfate oxidation on the abundance and activity of the indigenous microbial community and phenanthrene-degrading bacteria in contaminated soil from a former manufactured gas plant (MGP) site. Approximately six pore volumes of a 20 g/L persulfate solution were introduced into the column, followed by simulated groundwater for 500 d. Soil samples were collected from the surface of the soil bed and along the column length immediately before and after persulfate injection and up to 500 d following injection. Exposure to persulfate led to a two- to three-log reduction in total bacterial 16S rRNA genes, severe inhibition of 14C-acetate mineralization (as a measure of general microbial activity), and a decrease in community diversity. However, relatively rapid recovery of both bacterial gene abundance and activity was observed within 30 d after persulfate exposure. Mineralization of 14C-phenanthrene was also inhibited but did not recover until 100 d post-oxidation. Known phenanthrene-degrading bacterial groups decreased to below detection limits throughout the column, with recovery times from 100 d to 500 d after persulfate injection. These findings suggest that coupling biological processes with persulfate oxidation is possible, although recovery of specific contaminant degraders may occur much later than the general microbial community recovers. Furthermore, the use of total bacterial quantity or non-specific measures of activity as a surrogate for the recovery of contaminant degraders may be inappropriate for evaluating the compatibility of chemical treatment with subsequent bioremediation. PMID:21162560

  12. [Effect of constructed wetland on the purification of industrial zone rainfall runoff contaminated with phenanthrene].

    PubMed

    Jing, Dan-Dan; Wan, Jin-Quan; Ma, Yong-Wen; Li, Dong-Ya; Wang, Yan; Huang, Ming-Zhi

    2013-08-01

    According to the water characteristics of industrial rainfall runoff in the catchment of Tongsha Reservoir, Dongguan City, a subsurface-flow constructed wetland (SSFCW) was used to treat simulated rainfall and the spatial variation of removal efficiency of contaminants in the wetland bed was analyzed. The longitudinal and vertical variation of removal efficiency of COD, NH4(+) -N, TN, TP and phenanthrene were examined. Enzyme activity of polyphenol oxidase (PPO) and nitrate reductase (NR) along the wetland bed were analyzed as well, meanwhile, four biogeochemical indexes of the wetland system, including DO, pH, ORP and water temperature, were monitored and their influences on the removal efficiency of contaminants and enzyme activity were analyzed. Results showed that DO, pH, ORP, water temperature all presented a decreasing tendency along the wetland bed, and the removal of COD, TP and phenanthrene occurred mainly in the front quarter of the wetland system; in the vertical direction, DO and ORP in the upper wetland bed were significantly higher than those in the ground floor, suggesting that the horizontal subsurface system was in an anaerobic or anoxic condition. The removal rates of COD, TP, TN, NH4(+) -N and phenanthrene were 1.17-1.36, 2.04-2.11, 1.40-1.92, 1.37-2.30, and 1.07-1.36 times higher than those at the bottom, respectively. Therefore, the vertical variation of purification efficiency was more significant than the longitudinal variation. A significant positive correlation was determined between the enzyme activity of NR and the NO3(-) -N concentration, but the longitudinal variation in the enzyme activity of NR and PPO was not obvious.

  13. Disposition of phenanthrene and octachlorostyrene in spiny lobsters, Panulirus argus, after intragastric administration

    SciTech Connect

    Solbakken, J.E.; Knap, A.H.

    1986-11-01

    Spiny lobster (Panulirus argus) is a commercial crustacean in Bermuda. It was therefore of interest to study the fate of xenobiotics in the species as very little attention has been paid to toxicological studies with spiny lobsters. Earlier it was found that the temperate crustacean, Nephrops norveqicus (Norway lobster) had the ability to accumulate and eliminate phenanthrene. The aim of this investigation was to gain a better understanding of the fate of xenobiotics in crustaceans under different environmental conditions, and to compare the polycyclic aromatic hydrocarbon, phenenthrene, with the more environmentally persistent chlorinated compound octachlorostyrene, a by-product of magnesium metal production.

  14. Phenotypic and genotypic characterization of phenanthrene-degrading fluorescent Pseudomonas biovars

    SciTech Connect

    Johnsen, K.; Andersen, S.; Jacobsen, C.S.

    1996-10-01

    The genus Pseudomonas is a group of gram-negative motile rods know for large metabolic versatility as well as pathogenicity to plants, animals and humans. A large number of bacteria from this group capable of degrading polycyclic aromatic hydrocarbons have been isolated in soils and aquifers, but the identification is often conducted only to the Pseudomonas sp. level. This study aims to characterize a group of bacteria from the fluorescent Pseudomonas group degrading phenanthrene by four different methods to assess the bacterial diversity of the closely related group. 37 refs., 3 figs., 1 tab.

  15. Accumulation and elimination of (9-/sup 14/C)phenanthrene in the calico clam (Macrocallista maculata)

    SciTech Connect

    Solbakken, J.E.; Jeffrey, F.M.H.; Knap, A.H.; Palmork, K.H.

    1982-05-01

    The accumulation and elimination of radoactivity is studied after exposure of (9-/sup 14/C) phenanthrene in various tissues in the calico clam (Macrocallista maculata). Results show that accumulation is highest in the lipid-rich hepatopancreas, and the elimination is very efficient compared to the horse mussel. The calico clam, which is a sand-dwelling organism, can easily come in contact with hydrocarbon contaminated sedments and might accumulate the hydrocarbons at different extents in various tissues. The efficient elimination, however, will prevent a lasting accumulation. (JMT)

  16. Accurate spectroscopy of polycyclic aromatic compounds: from the rotational spectrum of fluoren-9-one in the millimeter wave region to its infrared spectrum.

    PubMed

    Maris, Assimo; Calabrese, Camilla; Melandri, Sonia; Blanco, Susana

    2015-01-14

    The rotational spectrum of fluoren-9-one, a small oxygenated polycyclic aromatic hydrocarbon, has been recorded and assigned in the 52-74.4 GHz region. The determined small negative value of the inertia defect (-0.3 u Å(2)) has been explained in terms of vibrational-rotational coupling constants calculated at the B3LYP/cc-pVTZ level of theory. Vibrational anharmonic analysis together with second-order vibrational perturbation theory approximation was applied both to fluorenone and its reduced form, fluorene, to predict the mid- and near-infrared spectra. The data presented here give precise indication on the fluorenone ground state structure, allow for an accurate spectral characterization in the millimeter wave and infrared regions, and hopefully will facilitate extensive radio astronomical searches with large radio telescopes.

  17. Fluorene-Based Copolymers Containing Dinaphtho-s-indacene as New Building Blocks for High-Efficiency and Color-Stable Blue LEDs.

    PubMed

    Guo, Xin; Cheng, Yanxiang; Xie, Zhiyuan; Geng, Yanhou; Wang, Lixiang; Jing, Xiabin; Wang, Fosong

    2009-05-19

    By incorporating a new building block, 7,7,15,15-tetraoctyldinaphtho-s-indacene (NSI), into the backbone of poly(9,9-dioctylfluorene) (PFO), a novel series of blue light-emitting copolymers (PFO-NSI) have been developed. The insertion of the NSI unit into the PFO backbone leads to the increase of local effective conjugation length, to form low-energy fluorene-NSI-fluorene (FNF) segments that serve as exciton trapping sites, to which the energy transfers from the high-energy PFO segments. This causes these copolymers to show red-shifted emissions compared with PFO, with a high efficiency and good color stability and purity. The best device performance with a luminance efficiency of 3.43 cd · A(-1) , a maximum brightness of 6 539 cd · m(-2) , and CIE coordinates of (0.152, 0.164) was achieved.

  18. Accurate spectroscopy of polycyclic aromatic compounds: from the rotational spectrum of fluoren-9-one in the millimeter wave region to its infrared spectrum.

    PubMed

    Maris, Assimo; Calabrese, Camilla; Melandri, Sonia; Blanco, Susana

    2015-01-14

    The rotational spectrum of fluoren-9-one, a small oxygenated polycyclic aromatic hydrocarbon, has been recorded and assigned in the 52-74.4 GHz region. The determined small negative value of the inertia defect (-0.3 u Å(2)) has been explained in terms of vibrational-rotational coupling constants calculated at the B3LYP/cc-pVTZ level of theory. Vibrational anharmonic analysis together with second-order vibrational perturbation theory approximation was applied both to fluorenone and its reduced form, fluorene, to predict the mid- and near-infrared spectra. The data presented here give precise indication on the fluorenone ground state structure, allow for an accurate spectral characterization in the millimeter wave and infrared regions, and hopefully will facilitate extensive radio astronomical searches with large radio telescopes. PMID:25591363

  19. Impact of Zn, Cu, Al and Fe on the partitioning and bioaccessibility of (14)C-phenanthrene in soil.

    PubMed

    Obuekwe, Ifeyinwa S; Semple, Kirk T

    2013-09-01

    This investigation considered the effects of Zn, Cu, Al and Fe (50 and 500 mg kg(-1)) on the loss, sequential extractability, using calcium chloride (CaCl2), hydroxypropyl-β-cyclodextrin (HPCD) and dichloromethane (DCM) and biodegradation of (14)C-phenanthrene in soil over 63 d contact time. The key findings were that the presence of Cu and Al (500 mg kg(-1)) resulted in larger amounts of (14)C-phenanthrene being extracted by CaCl2 and HPCD. Further, the CaCl2 + HPCD extractions directly predicted the biodegradation of the PAH in the presence of the metals, with the exception of 500 mg kg(-1) Cu and Zn. The presence of high concentrations of some metals can impact on the mobility and accessibility of phenanthrene in soil, which may impact on the risk assessment of PAH contaminated soil. PMID:23770460

  20. Metabolism of a Representative Oxygenated Polycyclic Aromatic Hydrocarbon (PAH) Phenanthrene-9,10-quinone in Human Hepatoma (HepG2) Cells

    PubMed Central

    2014-01-01

    Exposure to polycyclic aromatic hydrocarbons (PAHs) in the food chain is the major human health hazard associated with the Deepwater Horizon oil spill. Phenanthrene is a representative PAH present in crude oil, and it undergoes biological transformation, photooxidation, and chemical oxidation to produce its signature oxygenated derivative, phenanthrene-9,10-quinone. We report the downstream metabolic fate of phenanthrene-9,10-quinone in HepG2 cells. The structures of the metabolites were identified by HPLC–UV–fluorescence detection and LC–MS/MS. O-mono-Glucuronosyl-phenanthrene-9,10-catechol was identified, as reported previously. A novel bis-conjugate, O-mono-methyl-O-mono-sulfonated-phenanthrene-9,10-catechol, was discovered for the first time, and evidence for both of its precursor mono conjugates was obtained. The identities of these four metabolites were unequivocally validated by comparison to authentic enzymatically synthesized standards. Evidence was also obtained for a minor metabolic pathway of phenanthrene-9,10-quinone involving bis-hydroxylation followed by O-mono-sulfonation. The identification of 9,10-catechol conjugates supports metabolic detoxification of phenanthrene-9,10-quinone through interception of redox cycling by UGT, COMT, and SULT isozymes and indicates the possible use of phenanthrene-9,10-catechol conjugates as biomarkers of human exposure to oxygenated PAH. PMID:24646012

  1. Metabolism of a representative oxygenated polycyclic aromatic hydrocarbon (PAH) phenanthrene-9,10-quinone in human hepatoma (HepG2) cells.

    PubMed

    Huang, Meng; Zhang, Li; Mesaros, Clementina; Zhang, Suhong; Blaha, Michael A; Blair, Ian A; Penning, Trevor M

    2014-05-19

    Exposure to polycyclic aromatic hydrocarbons (PAHs) in the food chain is the major human health hazard associated with the Deepwater Horizon oil spill. Phenanthrene is a representative PAH present in crude oil, and it undergoes biological transformation, photooxidation, and chemical oxidation to produce its signature oxygenated derivative, phenanthrene-9,10-quinone. We report the downstream metabolic fate of phenanthrene-9,10-quinone in HepG2 cells. The structures of the metabolites were identified by HPLC-UV-fluorescence detection and LC-MS/MS. O-mono-Glucuronosyl-phenanthrene-9,10-catechol was identified, as reported previously. A novel bis-conjugate, O-mono-methyl-O-mono-sulfonated-phenanthrene-9,10-catechol, was discovered for the first time, and evidence for both of its precursor mono conjugates was obtained. The identities of these four metabolites were unequivocally validated by comparison to authentic enzymatically synthesized standards. Evidence was also obtained for a minor metabolic pathway of phenanthrene-9,10-quinone involving bis-hydroxylation followed by O-mono-sulfonation. The identification of 9,10-catechol conjugates supports metabolic detoxification of phenanthrene-9,10-quinone through interception of redox cycling by UGT, COMT, and SULT isozymes and indicates the possible use of phenanthrene-9,10-catechol conjugates as biomarkers of human exposure to oxygenated PAH.

  2. Single-layer electroluminescent devices based on fluorene-1H-pyrazolo[3,4-b]quinoxaline co-polymers

    NASA Astrophysics Data System (ADS)

    Pokladko-Kowar, Monika; Danel, Andrzej; Chacaga, Łukasz

    2013-11-01

    A fluorene based copolymer was synthesized for electroluminescent application. To the main chain of polymer the nitrogen heterocyclic, 1H-pyrazolo[3,4-b]quinoxaline, unit was introduced. The incorporation of this derivative tuned the emission from the blue to yellow-green one. A simple, single layered device was fabricated with the configuration ITO/PEDOT/co-poly-FLU-PQX/Ca/Mg.

  3. An integrated experimental and quantum chemical study on the complexation properties of (9‧-fluorene)-spiro-5-hydantoin and its thioanalogue

    NASA Astrophysics Data System (ADS)

    Ahmedova, Anife; Marinova, Petja; Marinov, Marin; Stoyanov, Neyko

    2016-03-01

    The reactivities of (9‧-fluorene)-spiro-5-hydantoin and its thio-analogue with Cu(II) were studied in different reaction conditions and the formed products were characterized by spectroscopic methods (IR, NMR and/or EPR). It was found that unlike the 2,4-dithio- analogue, both the (9‧-fluorene)-spiro-5-hydantoin and its 2-thio derivative form Cu(II) complexes only in presence of a strong base. We identified the coordination mode of the ligands and the structure of the complexes through geometry optimization of different models and calculations of the corresponding spectroscopic parameters using ab initio quantum chemical methods. The comparison between the experimental and the theoretical data suggested monodentate coordination of the fluorene-hydantoin ligands after deprotonation of one amido group. Additional confirmations of this proposition were obtained from the experimental and DFT-calculated EPR parameters (g-factor and A-tensor), which allowed for determination of the most probable geometry of the complexes. We further employed the quantum chemical methods to explain the observed differences in the complexation abilities of variously spiro-5-substituted thio- and dithio-hydantoins, accounting for the structural effects on the electron density and acidity of the hydantoin ring.

  4. Comparison of amphiphilic polyurethane nanoparticles to nonionic surfactants for flushing phenanthrene from soil.

    PubMed

    Kim, Ju-Young; Shim, Sun-Bo; Shim, Jin-Kie

    2004-12-31

    Amphiphilic polyurethane (APU) nanoparticles were synthesized through crosslinking polymerization of nano-aggregates of urethane acrylate nonionomer (UAN). The efficiency of in situ extraction of sorbed phenanthrene from aquifer material was tested using soil columns and compared with that of surfactants such as Triton X-100, Brij 30, and Tween 80. The extraction efficiency of those washing materials strongly depended on their concentration, flow rate, and the degree of sorption within soil column. That is, the extraction efficiency increased with the decrease of flow rate and the degree of sorption and the increase of the concentration. Even though the surfactants are superior to APU nanoparticles at solubilizing phenanthrene, at the same flow rate (0.02 mL/min) and concentration (4000 mg/L), the effectiveness of in situ soil washing of APU nanoparticles was about two times higher than those of surfactants. This is because, at the lower flow rates, the degree of sorption of APU nanoparticles was lower than that of surfactants, owing to the chemically crosslinked nature of APU nanoparticles.

  5. Complex conductivity response to microbial growth and biofilm formation on phenanthrene spiked medium

    NASA Astrophysics Data System (ADS)

    Albrecht, Remy; Gourry, Jean Christophe; Simonnot, Marie-Odile; Leyval, Corinne

    2011-11-01

    Several laboratory studies have recently demonstrated the utility of geophysical methods for the investigation of microbial-induced changes over contaminated sites. However, it remains difficult to distinguish the effects due to the new physical properties imparted by microbial processes, to bacterial growth, or to the development of bacterial biofilm. We chose to study the influence of biofilm formation on geophysical response using complex conductivity measurements (0.1-1000 Hz) in phenanthrene-contaminated media. Biotic assays were conducted with two phenanthrene (PHE) degrading bacterial strains: Burkholderia sp (NAH1), which produced biofilm and Stenophomonas maltophilia (MATE10), which did not, and an abiotic control. Results showed that bacterial densities for NAH1 and MATE10 strains continuously increased at the same rate during the experiment. However, the complex conductivity signature showed noticeable differences between the two bacteria, with a phase shift of 50 mrad at 4 Hz for NAH1, which produced biofilm. Biofilm volume was quantified by Scanning Confocal Laser Microscopy (SCLM). Significant correlations were established between phase shift decrease and biofilm volume for NAH1 assays. Results suggest that complex conductivity measurements, specifically phase shift, can be a useful indicator of biofilm formation inside the overall signal of microbial activity on contaminated sites.

  6. [Dynamic changes of physicochemical properties in phenanthrene-contaminated soil under wheat and clover intercropping].

    PubMed

    Zhang, Xiao-bin; Zhan, Xin-hua; Zhou, Li-xiang; Liang, Xiao

    2011-05-01

    Soil physicochemical properties play an important role in the efficiency of phytoremediation and soil arability after phytoremediation. Soil pot experiments were conducted to investigate the dynamic changes of physicochemical properties in phenanthrene (a representative of polycyclic aromatic hydrocarbons)-contaminated soil under wheat and clover intercropping. The results showed that plants improved the pH values of phenanthrene-polluted soil with a maximum variation pH of 0.61. The difference in pH between wheat/clover intercropping and wheat/clover single cropping was not significant. Soil organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus, cation exchange capacity and available potassium decreased over the experiment period due to biodecomposition and plant root absorption. The intercropping of wheat and alfalfa accelerated the consumption of the above-mentioned nutrients. And the decrease percentages ranged from 5.24% to 57.85%, more than those of wheat or alfalfa only planted with decrease percentages between 6.29% and 39.09%. In particular, soil available nitrogen and availiable phosphorus decreased more than the other nutrients with a maximum reduction percentage of 57.85%. Therefore, the application of nitrogen and phosphorus must be paid more attention during phytoremediation of polycyclic aromatic hydrocarbon-contaminated soil in the wheat and alfalfa intercropping system.

  7. Determination of phenanthrene by antibody-coated competitive real-time immuno-PCR assay.

    PubMed

    Zhou, Chun; Wang, Qiong-E; Zhuang, Hui-Sheng

    2008-08-01

    A reliable selective and sensitive antibody-coated competitive real-time immuno-PCR (RT-IPCR) assay for the determination of phenanthrene (PH) was developed. Phenanthrene butanoic acid (gamma-oxo-PHA) was synthesized as the hapten of PH. An active ester method was used to couple the PHA to bovine serum albumin to form an artificial immune antigen. Male New Zealand white rabbits were immunized with immune antigen to obtain polyclonal antibodies, with which a novel RT-IPCR assay for determination of PH was developed. Under the optimized assay conditions, PH can be determined in the concentration range from 10 fg/mL to 100 pg/mL with a detection limit of 5 fg/mL. The cross-reactivities of the anti-PH antibody to seven structurally related compounds were below 12.5%. Some environmental water samples were analyzed with satisfactory results, which showed good accuracy and suitability to analyze PH in environmental water. Compared with high-performance liquid chromatography, the recovery was lower or higher with agitation but would still be acceptable for use in an on-site field test to provide rapid, semiquantitative, and reliable test results for making environmental decisions. PMID:18587564

  8. Investigating the role of mineral-bound humic acid in phenanthrene sorption.

    PubMed

    Feng, Xiaojuan; Simpson, André J; Simpson, Myrna J

    2006-05-15

    Contaminant-soil interaction studies have indicated that physical conformation of organic matter atthe solid-aqueous interface is important in governing hydrophobic organic compound (HOC) sorption. To testthis, organo-clay complexes were constructed by coating montmorillonite and kaolinite with peat humic acid (PHA) in Na+ or Ca2+ dominated solutions with varying pH and ionic strength values. The solution conditions encouraged the dissolved PHA to adopt a "coiled" or "stretched" conformation prior to interacting with the clay mineral surface. Both kaolinite and montmorillonite organo-clay complexes exhibited higher phenanthrene sorption (Koc values) with decreasing pH, indicating that the coiled configuration provided more favorable sorption conditions. Evidence from 1H high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) indicated that polymethylene groups were prevalent at the surface of the organo-clay complexes and may enhance sorptive interactions. Preferential sorption of polymethylene groups on kaolinite and aromatic compounds on montmorillonite may also contribute to the difference in phenanthrene sorption by PHA associated with these two types of clay. This study demonstrates the importance of solution conditions in the sorption of nonionic, hydrophobic organic contaminants and also provides evidence for the indirect role of clay minerals in sorption of contaminants at the soil-water interface. PMID:16749691

  9. Repression of Pseudomonas putida phenanthrene-degrading activity by plant root extracts and exudates.

    PubMed

    Rentz, Jeremy A; Alvarez, Pedro J J; Schnoor, Jerald L

    2004-06-01

    The phenanthrene-degrading activity (PDA) of Pseudomonas putida ATCC 17484 was repressed after incubation with plant root extracts of oat (Avena sativa), osage orange (Maclura pomifera), hybrid willow (Salix alba x matsudana), kou (Cordia subcordata) and milo (Thespesia populnea) and plant root exudates of oat (Avena sativa) and hybrid poplar (Populus deltoides x nigra DN34). Total organic carbon content of root extracts ranged from 103 to 395 mg l(-1). Characterization of root extracts identified acetate (not detectable to 8.0 mg l(-1)), amino acids (1.7-17.3 mg l(-1)) and glucose (1.6-14.0 mg l(-1)), indicating a complex mixture of substrates. Repression was also observed after exposure to potential root-derived substrates, including organic acids, glucose (carbohydrate) and glutamate (amino acid). Carbon source regulation (e.g. catabolite repression) was apparently responsible for the observed repression of P. putida PDA by root extracts. However, we showed that P. putida grows on root extracts and exudates as sole carbon and energy sources. Enhanced growth on root products may compensate for partial repression, because larger microbial populations are conducive to faster degradation rates. This would explain the commonly reported increase in phenanthrene removal in the rhizosphere.

  10. In depth analysis of the quenching of three fluorene-phenylene-based cationic conjugated polyelectrolytes by DNA and DNA bases.

    PubMed

    Davies, Matthew L; Douglas, Peter; Burrows, Hugh D; Martincigh, Bice; Miguel, Maria da Graça; Scherf, Ullrich; Mallavia, Ricardo; Douglas, Alastair

    2014-01-16

    The interaction of three cationic poly {9,9-bis[N,N-(trimethylammonium)hexyl]fluorene-co-1,4-phenylene} polymers with average chain lengths of ∼6, 12, and 100 repeat units (PFP-NR36(I),12(Br),100(Br)) with both double and single stranded, short and long, DNA and DNA bases have been studied by steady state and time-resolved fluorescence techniques. Fluorescence of PFP-NR3 polymers is quenched with high efficiency by DNA (both double and single stranded) and DNA bases. The resulting quenching plots are sigmoidal and are not accurately described by using a Stern-Volmer quenching mechanism. Here, the quenching mechanism is well modeled in terms of an equilibrium in which a PFP-NR3/DNA aggregate complex is formed which brings polymer chains into close enough proximity to allow interchain excitation energy migration and quenching at aggregate or DNA base traps. Such an analysis gives equilibrium constants of 8.4 × 10(6) (±1.2 × 10(6)) M(-1) for short-dsDNA and 8.6 × 10(6) (±1.7 × 10(6)) M(-1) for short-ssDNA with PFP-NR36(I).

  11. Protective spin-labeled fluorenes maintain amyloid beta peptide in small oligomers and limit transitions in secondary structure

    SciTech Connect

    Altman, Robin; Ly, Sonny; Hilt, Silvia; Petrlova, Jitka; Maezawa, Izumi; Kálai, Tamás; Hideg, Kálmán; Jin, Lee-Way; Laurence, Ted A.; Voss, John C.

    2015-12-01

    Alzheimer’s disease is characterized by the presence of extracellular plaques comprised of amyloid beta (Aβ) peptides. Soluble oligomers of the Aβ peptide underlie a cascade of neuronal loss and dysfunction associated with Alzheimer's disease. Single particle analyses of Aβ oligomers in solution by fluorescence correlation spectroscopy (FCS) were used to provide real-time descriptions of how spin-labeled fluorenes (SLFs; bi-functional small molecules that block the toxicity of Aβ) prevent and disrupt oligomeric assemblies of Aβ in solution. The FCS results, combined with electron paramagnetic resonance spectroscopy and circular dichroism spectroscopy, demonstrate SLFs can inhibit the growth of Aβ oligomers and disrupt existing oligomers while retaining Aβ in a largely disordered state. Furthermore, while the ability of SLF to block Aβ toxicity correlates with a reduction in oligomer size, our results suggest the conformation of Aβ within the oligomer determines the toxicity of the species. Attenuation of Aβ toxicity, which has been associated primarily with the soluble oligomeric form, can be achieved through redistribution of the peptides into smaller oligomers and arrest of the fractional increase in beta secondary structure.

  12. Structure and Self-Assembly of Oligocarbonate-Fluorene End Functionalized Poly (ethylene glycol) ABA Triblock Polymer

    NASA Astrophysics Data System (ADS)

    Wei, Guangmin; Prabhu, Vivek; Venkataraman, Shrinivas; Yang, Yi Yan; Hedrick, James; Vivek Prabhu Team; Shrinivas Venkataraman, Yi Yan Yang Collaboration; James Hedrick Collaboration

    Hierarchical structures of oligocarbonate-fluorene end-functionalized poly(ethylene glycol) triblock copolymer (P(F-TMC)m-PEG444-P(F-TMC)m) were characterized by light scattering, atomic force microscopy, and Ultraviolet-visible spectroscopy in dilute regime in water, a poor solvent of F-TMC block. The evidence for pai-pai stacked of F-TMC block in self-assembled structure was provided. The self-assembly behavior is highly dependent on concentration and F-TMC block length, m. The presence of clusters dominates the population of scatterers once m is larger than 2, where there is no clear evidence of a separation of micelles and clusters. The molecular aggregation driven by F-TMC groups appears too strong to permit labile micelle-cluster dynamics as observed with m = 2 and 1.2. The non-mean field scaling of the aggregation number, when compared to models for triblock copolymers, highlights the need for a molecular-based model to predict the self-assembly at low end-group numbers. In our case, the end-groups are oligomers, so the comparison to Flory scaling may not be justified.

  13. CeO2 nanoparticles induce no changes in phenanthrene toxicity to the soil organisms Porcellionides pruinosus and Folsomia candida.

    PubMed

    Tourinho, Paula S; Waalewijn-Kool, Pauline L; Zantkuijl, Irene; Jurkschat, Kerstin; Svendsen, Claus; Soares, Amadeu M V M; Loureiro, Susana; van Gestel, Cornelis A M

    2015-03-01

    Cerium oxide nanoparticles (CeO2 NPs) are used as diesel fuel additives to catalyze oxidation. Phenanthrene is a major component of diesel exhaust particles and one of the most common pollutants in the environment. This study aimed at determining the effect of CeO2 NPs on the toxicity of phenanthrene in Lufa 2.2 standard soil for the isopod Porcellionides pruinosus and the springtail Folsomia candida. Toxicity tests were performed in the presence of CeO2 concentrations of 10, 100 or 1000mg Ce/kg dry soil and compared with results in the absence of CeO2 NPs. CeO2 NPs had no adverse effects on isopod survival and growth or springtail survival and reproduction. For the isopods, LC50s for the effect of phenanthrene ranged from 110 to 143mg/kg dry soil, and EC50s from 17.6 to 31.6mg/kg dry soil. For the springtails, LC50s ranged between 61.5 and 88.3mg/kg dry soil and EC50s from 52.2 to 76.7mg/kg dry soil. From this study it may be concluded that CeO2 NPs have a low toxicity and do not affect toxicity of phenanthrene to isopods and springtails. PMID:25499053

  14. CeO2 nanoparticles induce no changes in phenanthrene toxicity to the soil organisms Porcellionides pruinosus and Folsomia candida.

    PubMed

    Tourinho, Paula S; Waalewijn-Kool, Pauline L; Zantkuijl, Irene; Jurkschat, Kerstin; Svendsen, Claus; Soares, Amadeu M V M; Loureiro, Susana; van Gestel, Cornelis A M

    2015-03-01

    Cerium oxide nanoparticles (CeO2 NPs) are used as diesel fuel additives to catalyze oxidation. Phenanthrene is a major component of diesel exhaust particles and one of the most common pollutants in the environment. This study aimed at determining the effect of CeO2 NPs on the toxicity of phenanthrene in Lufa 2.2 standard soil for the isopod Porcellionides pruinosus and the springtail Folsomia candida. Toxicity tests were performed in the presence of CeO2 concentrations of 10, 100 or 1000mg Ce/kg dry soil and compared with results in the absence of CeO2 NPs. CeO2 NPs had no adverse effects on isopod survival and growth or springtail survival and reproduction. For the isopods, LC50s for the effect of phenanthrene ranged from 110 to 143mg/kg dry soil, and EC50s from 17.6 to 31.6mg/kg dry soil. For the springtails, LC50s ranged between 61.5 and 88.3mg/kg dry soil and EC50s from 52.2 to 76.7mg/kg dry soil. From this study it may be concluded that CeO2 NPs have a low toxicity and do not affect toxicity of phenanthrene to isopods and springtails.

  15. A novel passive dosing system for determining the toxicity of phenanthrene to early life stages of zebrafish.

    PubMed

    Butler, Josh D; Parkerton, Thomas F; Letinski, Daniel J; Bragin, Gail E; Lampi, Mark A; Cooper, Keith R

    2013-10-01

    Reliable experimental early life stage chronic toxicity data for fish are limited and further data are needed for polyaromatic hydrocarbons to establish environmental quality objectives and compare with toxicity model predictions. Efforts are underway to develop a zebrafish embryo toxicity test guideline to reduce, refine and replace the use of vertebrates in animal testing. An adaptation of this method which includes embryo lethal and sub-lethal developmental endpoints after a 5-day exposure as well as larval survival and growth endpoints during a subsequent 25-day test period is described using phenanthrene as a model test substance. To deliver well controlled exposure concentrations, a passive dosing system consisting of silicone coated vials and silicone O-rings was employed. Acute results indicated that edema and spinal curvature were the most sensitive sub-lethal effects observed and in many cases preceded observed mortality. The 30-day LC/EC10 for larval survival and growth was 40 and 67 μg/L respectively. Concentrations shown to cause adverse effects in this study are in the range of previous studies that have investigated the chronic effects of phenanthrene on fish. Further, results indicate that predicted water quality objectives for phenanthrene derived using the target lipid model are protective of early life stage effects on zebrafish. Based on these results the predicted water quality objectives for phenanthrene derived using the target lipid model (10 μg/L) would be protective of early life stage effects on zebrafish. PMID:23872248

  16. Intermolecular sequential [4 + 2]-cycloaddition-aromatization reaction of aryl-substituted allenes with DMAD affording phenanthrene and naphthalene derivatives.

    PubMed

    Jiang, Xuefeng; Kong, Wangqing; Chen, Jie; Ma, Shengming

    2008-10-01

    An efficient entry to phenanthrene and naphthalene derivatives through intermolecular sequential [4 + 2]-cycloaddition-aromatization reactions of aryl-substituted allenes with DMAD in the absence of any catalyst was discovered. In this reaction the aromatic ring and the adjacent carbon-carbon double bond of the allene unit acted as the 1,3-diene.

  17. [Effect of the inoculant strain Sphingomonas paucimobilis 20006FA on the bacterial composition of a phenanthrene-degrading consortium].

    PubMed

    Madueño, L; Coppotelli, B M; Morelli, I S

    2009-01-01

    The effect of the inoculant strain Sphingomonas paucimobilis 20006FA on the bacterial composition of a phenanthrene-degrading consortium obtained from a pristine soil in sequencing batch cultures was studied. Inoculated (F200+1) and non-inoculated (F200) phenanthrene-degrading consortia, were obtained. Bacterial diversity of consortia was studied at cultivable (phenotype and genotype characterization) and non-cultivable (PCR-DGGE) levels. During the successive cultures, a loss in the phenanthrene-degrading capacity and a decrease in the bacterial diversity were observed in both consortia. Although inoculation did not produce any significant changes in the consortia phenanthrene-degrading capacity (29.9% F200 and 27.6% F200+1), it did produce changes in the bacterial composition, showing a differential structural dynamics in the DGGE profiles of the inoculated consortium. In both consortia, a dominant band placed at the same position as that of the DNA of the inoculant strain in the DGGE gel could be observed. However, isolated cultures from the consortia which had an identical band position to that of S. paucimobilis 20006FA in the PCR-DGGE profile showed low similarity with respect to the inoculant strain (RAPD).

  18. UV light-mediated difunctionalization of alkenes with CF3SO2Na: synthesis of trifluoromethyl phenanthrene and anthrone derivatives.

    PubMed

    Li, Bing; Fan, Dan; Yang, Chao; Xia, Wujiong

    2016-06-21

    A metal-free and cost-effective protocol for UV light-mediated difunctionalization of alkenes with CF3SO2Na was developed. This strategy realized the direct formation of Csp(3)-CF3 and C-C bonds through a proposed tandem radical cyclization process, which produced a variety of phenanthrene and anthrone derivatives in moderate yields. PMID:27206267

  19. Biodegradation and adsorption of C1- and C2-phenanthrenes and C1- and C2-dibenzothiophenes in the presence of clay minerals: effect on forensic diagnostic ratios.

    PubMed

    Ugochukwu, Uzochukwu C; Head, Ian M; Manning, David A C

    2014-07-01

    The impact of modified montmorillonites on adsorption and biodegradation of crude oil C1-phenanthrenes, C1-dibenzothiophenes, C2-phenanthrenes and C2-dibenzothiophenes was investigated in aqueous clay/oil microcosm experiments with a hydrocarbon degrading microorganism community. Consequently, the effect on C1-dibenzothiophenes/C1-phenanthrenes, C2-dibenzothiophenes/C2-phenanthrenes, 2+3-methyldibenzothiophene/4-methyldibenzothiophene and 1-methyldibenzothiophene/4-methyldibenzothiophene ratios commonly used as diagnostic ratios for oil forensic studies was evaluated. The clay mineral samples were treated to produce acid activated montmorillonite, organomontmorillonite and homoionic montmorillonite which were used in this study. The different clay minerals (modified and unmodified) showed varied degrees of biodegradation and adsorption of the C1-phenanthrenes, C1-dibenzothiophenes, C2-phenanthrenes and C2-dibenzothiophenes. The study indicated that as opposed to biodegradation, adsorption has no effect on the diagnostic ratios. Among the diagnostic ratios reviewed, only C2-dibenzothiophenes/C2-phenanthrenes ratio was neither affected by adsorption nor biodegradation making this ratio very useful in forensic studies of oil spills and oil-oil correlation.

  20. Use of humic acids derived from peat and lignite as phenanthrene sorbents

    NASA Astrophysics Data System (ADS)

    Sofikitis, Elias; Giannouli, Andriana; Kalaitzidis, Stavros; Christanis, Kimon; Karapanagioti, Hrissi K.; Papanicolaou, Cassiani

    2015-04-01

    A broad range of materials is being applied for environmental remediation of water, among them sorbents such as humic acids. Being natural substances, the extraction and purification of humic acids might be cheaper than the production of synthetic sorbents. Having higher absorbing capacity than most of the sorbents used to date, humic acids have a competitive advantage against commonly used sorbents such as active charcoals and biochar. Humic acids are "complex colloidal super-mixtures" that are characterized by their functional groups. Therefore, composition and molecular formula can vary depending on the properties of the parent material. The aim of this project was (a) to study the sorption capacity of humic acids derived from peat and lignite samples picked up from deposits spread throughout Greece and (b) to compare the results with these of the parent materials. This comparison provides an insight to which matrix samples are suitable for further chemical treatment for the isolation of humic acids to be used as sorbents. The selected model pollutant was phenanthrene, which is a PAH that consists of three fused benzene rings. Humic acids were extracted according to the methodology proposed by the IHSS, slightly modified, in order to fit better to the properties of organic sediments. Sorption experiments were conducted by mixing 0.004 g of the sorbent (peat or lignite or humic acid) with aqueous solutions of phenanthrene at different concentrations of 30, 50, 100, 300, and 500 μg/L. The results show that phenanthrene sorption is higher for the humic acid than for the original lignite and peat samples. The original samples display higher sorption at the lower phenanthere solutions (30 μg/L; Kd ranges from 15,000 to 47,000 L/kg) than at the higher one (500 μg/L; Kd ranges from 4,100 to 13,000 L/Kg) suggesting non-linear sorption. The humic acids display mainly linear isotherms with Kd ranges from 6,600 to 120,000 L/kg. Concerning the suitability of the studied

  1. Aspects of the atmospheric chemistry of alkylnaphthalenes, phenanthrene and their atmospheric reaction products

    NASA Astrophysics Data System (ADS)

    Wang, Lin

    Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated and nitrated derivatives, observed in ambient atmospheres, are confirmed or suspected mutagens and animal carcinogens. They can undergo atmospheric chemical transformation processes, including photolysis and reactions with hydroxyl (OH) radicals, nitrate (NO3) radicals, Cl atoms and ozone (O3). In this work, atmospheric reactions were simulated in environmental chambers to study the atmospheric chemistry of naphthalene, alkylnaphthalenes, phenanthrene and their atmospheric reaction products, using chromatographic and spectroscopic techniques. Ambient measurements were conducted to assess the presence of atmospheric reaction products that were identified under laboratory conditions. Rate constants for the gas phase reactions of Cl atoms with naphthalene and alkylnaphthalenes were measured. The measured deuterium isotope effects and product yields indicate the reactions proceed by initial H- (or D-) atom abstraction. The products of the gas-phase reactions of OH radicals with naphthalene and alkylnaphthalenes were investigated. The major reaction products are ring-opened dicarbonyls that are 32 mass units higher in molecular weight than the parent compound, one or more ring-opened dicarbonyls of lower molecular weight resulting from loss of two beta-carbons and associated alkyl groups, and ring-containing compounds that may be epoxides. Phthalic anhydride and alkyl-substituted phthalic anhydrides were observed as second-generation products. A subsequent study investigated the photolysis and OH radical reactions of products formed from the OH radical-initiated reactions of naphthalene and alkylnaphthalenes, including phthaldialdehyde, 2-acetylbenzaldehyde and 1,2-diacetylbenzene. Environmental chamber studies have also been carried out to study the oxygenated and nitrated products from the gas-phase reactions of naphthalene and alkylnaphthalenes with NO3 radicals. Observed profiles of dimethyl

  2. Urinary naphthalene and phenanthrene as biomarkers of occupational exposure to polycyclic aromatic hydrocarbons

    PubMed Central

    Sobus, Jon R.; Waidyanatha, Suramya; McClean, Michael D.; Herrick, Robert F.; Smith, Thomas J.; Garshick, Eric; Laden, Francine; Hart, Jaime E.; Zheng, Yuxin; Rappaport, Stephen M.

    2009-01-01

    Objectives We investigated the utility of unmetabolized naphthalene (Nap) and phenanthrene (Phe) in urine as surrogates for exposures to mixtures of polycyclic aromatic hydrocarbons (PAHs). Methods Our study included workers exposed to diesel exhausts (low PAH exposure level, n = 39) as well as those exposed to emissions from asphalt (medium PAH exposure level, n = 26) and coke ovens (high PAH exposure level, n = 28). Levels of Nap and Phe were measured in urine from each subject using head space-solid phase microextraction and gas chromatography-mass spectrometry. Published levels of airborne Nap, Phe, and other PAHs in the coke-producing and aluminum industries were also investigated. Results In post-shift urine, the highest estimated geometric mean concentrations of Nap and Phe were observed in coke-oven workers (Nap: 2,490 ng/l; Phe: 975 ng/l), followed by asphalt workers (Nap: 71.5 ng/l; Phe: 54.3 ng/l), and by diesel-exposed workers (Nap: 17.7 ng/l; Phe: 3.60 ng/l). After subtracting logged background levels of Nap and Phe from the logged post-shift levels of these PAHs in urine, the resulting values [referred to as ln(adjNap) and ln(adjPhe), respectively] were significantly correlated in each group of workers (0.71 ≤ Pearson r ≤ 0.89), suggesting a common exposure source in each case. Surprisingly, multiple linear regression analysis of ln(adjNap) on ln(adjPhe) showed no significant effect of the source of exposure (coke ovens, asphalt, and diesel exhaust) and further suggested that the ratio of urinary Nap/Phe (in natural scale) decreased with increasing exposure levels. These results were corroborated with published data for airborne Nap and Phe in the coke-producing and aluminum industries. The published air measurements also indicated that Nap and Phe levels were proportional to the levels of all combined PAHs in those industries. Conclusion Levels of Nap and Phe in urine reflect airborne exposures to these compounds and are promising surrogates for

  3. Planar conjugated polymers containing 9,10-disubstituted phenanthrene units for efficient polymer solar cells.

    PubMed

    Li, Guangwu; Kang, Chong; Li, Cuihong; Lu, Zhen; Zhang, Jicheng; Gong, Xue; Zhao, Guangyao; Dong, Huanli; Hu, Wenping; Bo, Zhishan

    2014-06-01

    Four novel conjugated polymers (P1-4) with 9,10-disubstituted phenanthrene (PhA) as the donor unit and 5,6-bis(octyloxy)benzothiadiazole as the acceptor unit are synthesized and characterized. These polymers are of medium bandgaps (2.0 eV), low-lying HOMO energy levels (below -5.3 eV), and high hole mobilities (in the range of 3.6 × 10(-3) to 0.02 cm(2) V(-1) s(-1) ). Bulk heterojunction (BHJ) polymer solar cells (PSCs) with P1-4:PC71 BM blends as the active layer and an alcohol-soluble fullerene derivative (FN-C60) as the interfacial layer between the active layer and cathode give the best power conversion efficiency (PCE) of 4.24%, indicating that 9,10-disubstituted PhA are potential donor materials for high-efficiency BHJ PSCs.

  4. NAH plasmid-mediated catabolism of anthracene and phenanthrene to naphthoic acids.

    PubMed Central

    Menn, F M; Applegate, B M; Sayler, G S

    1993-01-01

    Pseudomonas fluorescens 5R contains an NAH7-like plasmid (pKA1), and P. fluorescens 5R mutant 5RL contains a bioluminescent reporter plasmid (pUTK21) which was constructed by transposon mutagenesis. Polymerase chain reaction mapping confirmed the localization of lux transposon Tn4431 300 bp downstream from the start of the nahG gene. Two degradation products, 2-hydroxy-3-naphthoic acid and 1-hydroxy-2-naphthoic acid, were recovered and identified from P. fluorescens 5RL as biochemical metabolites from the biotransformation of anthracene and phenanthrene, respectively. This is the first report which provides direct biochemical evidence that the naphthalene plasmid degradative enzyme system is involved in the degradation of higher-molecular-weight polycyclic aromatic hydrocarbons other than naphthalene. Images PMID:8328810

  5. The growth, photosynthesis and antioxidant defense responses of five vegetable crops to phenanthrene stress.

    PubMed

    Ahammed, Golam Jalal; Wang, Meng-Meng; Zhou, Yan-Hong; Xia, Xiao-Jian; Mao, Wei-Hua; Shi, Kai; Yu, Jing-Quan

    2012-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are global environmental problem. To better understand the growth and physiological responses to atmospheric PAHs, we investigated biomass, photosynthetic machinery and antioxidant system in pakchoi, cucumber, flowering chinese cabbage, tomato and lettuce under various levels of phenanthrene (PHE) stress. Foliar exposure to PHE for 14d resulted in a dose dependent decrease in growth, photosynthesis and chlorophyll contents. With few exceptions, antioxidant enzymes (superoxide dismutase, guaicol peroxidase, catalase, ascorbate peroxidase and glutathione reductase) were upregulated following exposure to PHE. Dose dependent increase in malondialdehyde contents together with H(2)O(2) accumulation suggested an occurrence of oxidative stress following PHE exposure. However, to some extent, growth and antioxidant defense responses differ from species to species. Difference in defense capacity might result in different tolerance and phytotoxicity among the studied vegetables. Taken together, phytotoxicity of PHE to five vegetables could be sequenced in the following order: pakchoi>cucumber>lettuce>tomato>flowering chinese cabbage.

  6. Atmospheric phenanthrene pollution modulates carbon allocation in red clover (Trifolium pratense L.).

    PubMed

    Desalme, Dorine; Binet, Philippe; Epron, Daniel; Bernard, Nadine; Gilbert, Daniel; Toussaint, Marie-Laure; Plain, Caroline; Chiapusio, Geneviève

    2011-10-01

    The influence of atmospheric phenanthrene (PHE) exposure (160 μg m(-3)) during one month on carbon allocation in clover was investigated by integrative (plant growth analysis) and instantaneous (13)CO(2) pulse-labelling approaches. PHE exposure diminished plant growth parameters (relative growth rate and net assimilation rate) and disturbed photosynthesis (carbon assimilation rate and chlorophyll content), leading to a 25% decrease in clover biomass. The root-shoot ratio was significantly enhanced (from 0.32 to 0.44). Photosynthates were identically allocated to leaves while less allocated to stems and roots. PHE exposure had a significant overall effect on the (13)C partitioning among clover organs as more carbon was retained in leaves at the expense of roots and stems. The findings indicate that PHE decreases root exudation or transfer to symbionts and in leaves, retains carbon in a non-structural form diverting photosynthates away from growth and respiration (emergence of an additional C loss process).

  7. Photodegradation of phenanthrene by N-doped TiO2 photocatalyst.

    PubMed

    Sirisaksoontorn, Weekit; Thachepan, Surachai; Songsasen, Apisit

    2009-07-15

    The photodegradation of phenanthrene has been catalyzed by nanostructures of TiO2 doped with nitrogen, N-doped TiO2. The N-doped TiO2 was prepared from the sol-gel reaction of Titanium(IV) bis(ethyl acetoacetato)diisopropoxide with 25% ammonia solution. The N-doped TiO2 was calcined at various temperatures from 300 to 700 degrees C. X-ray diffraction (XRD) results showed that N-doped TiO2 remained amorphous at 300 degrees C but anatase-to-rutile transformation started at 400 degrees C and was complete at 700 degrees C. The average particle size calculated from Scherrer's equation was in the range of 9-51 nm with surface area (S(BET)) of 253.7-4.8 m2/g. X-ray photoelectron spectroscopy (XPS) results confirmed the incorporation of nitrogen atoms (Ti-N bond) in the N-doped catalyst. Moreover, the percentage of nitrogen determined by Elemental analysis was 0.236% of N-doped calcined at 400 degrees C. UV-Vis reflection spectra indicated that N-doped TiO2 calcined at 400 degrees C shifted to the higher absorption edge in the range of visible light. N-doped TiO2 calcined at 400 degrees C successfully catalyzed the photodegradation of phenanthrene (80% conversion) whereas N-doped TiO2 calcined at 500 degrees C and P25 TiO2 failed as catalysts.

  8. Synthesis and Application of Tetrahydro-2H-fluorenes by a Pd(0)-Catalyzed Benzylic C(sp(3) )-H Functionalization.

    PubMed

    Suetsugu, Satoshi; Muto, Nobusuke; Horinouchi, Misa; Tsukano, Chihiro; Takemoto, Yoshiji

    2016-06-01

    A new method has been developed for the synthesis of tetrahydro-2H-fluorenes based on a Pd(0)-catalyzed benzylic C(sp(3) )-H functionalization. Importantly, the success of the cyclization step was dependent on there being substituents at the two positions ortho to the benzylic group to avoid an undesired C(sp(2) )-H functionalization. This method was subsequently used to prepare the right-hand fragment of the hexacyclic triterpenoid benzohopanes, and therefore represents a powerful tool for the construction of the related compounds.

  9. Gold-catalyzed cycloisomerization of 1,6-diyne carbonates and esters to 2,4a-dihydro-1H-fluorenes.

    PubMed

    Rao, Weidong; Koh, Ming Joo; Li, Dan; Hirao, Hajime; Chan, Philip Wai Hong

    2013-05-29

    A synthetic method to prepare 2,4a-dihydro-1H-fluorenes efficiently from gold(I)-catalyzed 1,2-acyloxy migration/cyclopropenation/Nazarov cyclization of 1,6-diyne carbonates and esters is described. The suggested reaction pathway provides rare examples of [2,3]-sigmatropic rearrangement in this class of compounds as well as the involvement of an in situ formed cyclopropene intermediate in gold catalysis. Experimental and ONIOM(QM:QM') [our own n-layered integrated molecular orbital and molecular mechanics(quantum mechanics:quantum mechanics')] computational studies based on the proposed Au carbenoid species provide insight into this unique selectivity. PMID:23627597

  10. [UV-spectrophotometry in drug control. 33. New drugs with benzene, pyridine, quinoline and phenanthrene chromophores in the molecule. 6. The effect of substitution and solvents].

    PubMed

    Krácmar, J; Krácmarová, J; Stejskal, Z

    1987-01-01

    UV-spectra of 14 new substances with benzene, pyridine, quinoline and phenanthrene chromophores as well as influences of substitutes and solvents on shifts of the bands E, K, B and R are discussed. PMID:2953035

  11. Combined remediation of Cd-phenanthrene co-contaminated soil by Pleurotus cornucopiae and Bacillus thuringiensis FQ1 and the antioxidant responses in Pleurotus cornucopiae.

    PubMed

    Jiang, Juan; Liu, Hongying; Li, Qiao; Gao, Ni; Yao, Yuan; Xu, Heng

    2015-10-01

    Remediation of soil co-contaminated with heavy metals and PAHs by mushroom and bacteria is a novel technique. In this study, the combined remediation effect of mushroom (Pleurotus cornucopiae) and bacteria (FQ1, Bacillus thuringiensis) on Cd and phenanthrene co-contaminated soil was investigated. The effect of bacteria (B. thuringiensis) on mushroom growth, Cd accumulation, phenanthrene degradation by P. cornucopiae and antioxidative responses of P. cornucopiae were studied. P. cornucopiae could adapt easily and grow well in Cd-phenanthrene co-contaminated soil. It was found that inoculation of FQ1 enhanced mushroom growth (biomass) and Cd accumulation with the increment of 26.68-43.58% and 14.29-97.67% respectively. Up to 100% and 95.07% of phenanthrene were removed in the bacteria-mushroom (B+M) treatment respectively spiked with 200mg/kg and 500mg/kg phenanthrene. In addition, bacterial inoculation alleviated oxidative stress caused by co-contamination with relative decreases in lipid peroxidation and enzyme activity, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). This study demonstrated that the integrated remediation strategy of bacteria and mushroom is an effective and promising method for Cd-phenanthrene co-contaminated soil bioremediation.

  12. Transcriptional responses indicate attenuated oxidative stress in the springtail Folsomia candida exposed to mixtures of cadmium and phenanthrene.

    PubMed

    de Boer, Muriel E; Ellers, Jacintha; van Gestel, Cornelis A M; den Dunnen, Johan T; van Straalen, Nico M; Roelofs, Dick

    2013-05-01

    Since the 'omics revolution', the assessment of toxic chemical mixtures has incorporated approaches where phenotypic endpoints are connected to a mechanistic understanding of toxicity. In this study we determined the effect of binary mixtures of cadmium and phenanthrene on the reproduction of Folsomia candida and investigated the cellular mechanisms underlying this response. Mixture toxicity modeling showed an antagonistic deviation from concentration addition for reproduction effects of the mixtures. Subsequent transcriptional response analysis was done using five mixtures at the modeled 50 % effect level for reproduction. The transcription profiles of 86 high throughput RT-qPCR assays were studied by means of partial least squares regression analysis. The first and second principal components (PCs) were correlated with global responses to cadmium and phenanthrene, while correlations with the mixture treatments were found in the higher PCs. Specifically associated with the mixture treatments were a biotransformation phase II gene, four mitochondrial related genes and a gene involved in the biosynthesis of antioxidant selenoproteins. Membrane integrity related gene inductions were correlated with the single phenanthrene treatment but not with the mixtures. Immune and inflammatory response assays did not correlate with any of the mixtures. These results suggest moderated oxidative stress, a higher mitochondrial maintenance and less compromised membrane function in the mixture exposed samples compared to the separate cadmium or phenanthrene exposures. The antagonism found for inhibition of reproduction may partially originate from these differences. Mechanistic studies on mixture toxicity can ultimately aid risk assessment by defining relevant toxicity pathways in organisms exposed to real-world mixture exposures present in the field. PMID:23483327

  13. Effects of nonionic surfactants on the microbial mineralization of phenanthrene in soil-water systems. [Quarterly report

    SciTech Connect

    Laha, S.; Luthy, R.G.

    1992-05-01

    The purpose of the work reported in this paper was to determine whether the inhibitory effect on microbial degradation of phenanthrene was specific to the nonionic surfactants used previously, i.e., the alkylethoxylate and alkylphenol ethoxylate surfactants. Thus, a number of nonionic surfactants of varying structures and properties were selected for further investigation. In addition, several tests were performed to verify results from earlier experiments.

  14. Enhancing plant-microbe associated bioremediation of phenanthrene and pyrene contaminated soil by SDBS-Tween 80 mixed surfactants.

    PubMed

    Ni, Hewei; Zhou, Wenjun; Zhu, Lizhong

    2014-05-01

    The use of surfactants to enhance plant-microbe associated dissipation in soils contaminated with polycyclic aromatic hydrocarbons (PAHs) is a promising bioremediation technology. This comparative study was conducted on the effects of plant-microbe treatment on the removal of phenanthrene and pyrene from contaminated soil, in the presence of low concentration single anionic, nonionic and anionic-nonionic mixed surfactants. Sodium dodecyl benzene sulfonate (SDBS) and Tween 80 were chosen as representative anionic and nonionic surfactants, respectively. We found that mixed surfactants with concentrations less than 150 mg/kg were more effective in promoting plant-microbe associated bioremediation than the same amount of single surfactants. Only about (m/m) of mixed surfactants was needed to remove the same amount of phenanthrene and pyrene from either the planted or unplanted soils, when compared to Tween 80. Mixed surfactants (< 150 mg/kg) better enhanced the degradation efficiency of phenanthrene and pyrene via microbe or plant-microbe routes in the soils. In the concentration range of 60-150 mg/kg, both ryegrass roots and shoots could accumulate 2-3 times the phenanthrene and pyrene with mixed surfactants than with Tween 80. These results may be explained by the lower sorption loss and reduced interfacial tension of mixed surfactants relative to Tween 80, which enhanced the bioavailability of PAHs in soil and the microbial degradation efficiency. The higher remediation efficiency of low dosage SDBS-Tween 80 mixed surfactants thus advanced the technology of surfactant-enhanced plant-microbe associated bioremediation.

  15. Analysis of hole mobility of fluorene derivative films based on the disorder model and relationship between disorder free mobility and reorganization energy in the Marcus theory

    NASA Astrophysics Data System (ADS)

    Era, M.; Mori, K.; Mototsu, N.

    2013-09-01

    Hole transporting behavior of two fluorene derivatives having carbazole group (2C1CBz) and diphenyl amino group (2C1DAF) and a carbazole derivative (C2CBzCBz) were investigated. Further, the fluorene derivatives and typical hole-transporting materials, 4,4'-bis[N-(p-tolyl)-N-phenyl-amino] biphenyl (TPD) and 4,4'-Bis(carbazol-9- yl)biphenyl (CBP) was analyzed based on the Gaussian Disorder Model. At room temperature, amorphous film of 2C1CBz exhibited highest hole mobility of 3.1 x 10-3 Vcm2/Vs at 1.6 x 105 Vcm-1 in these materials. From analysis based on the Gaussian Disorder Model, however, amorphous film of CBP is indicated to have highest disorder free mobility; the values of 2C1CBz, 2C1DAF, CBP and TPD were 0.812, 0.092, 2.84, and 0.38 cm2/Vs, respectively. In addition, their reorganization energy / was evaluated by a quantum mechanical calculation with ADF (Amsterdam Density Functional package, Scientific Computing and Modeling Co.) based on the Marcus theory. The experimental and calculation results demonstrated that the u0 has good proportionality relation with the /. Because theu0 mean as a rough standard of carrier-transporting, this result suggest that evaluation of / may be a promising approach to design molecular structure of carrier transporting materials with high carrier mobility.

  16. A non-fullerene electron acceptor based on fluorene and diketopyrrolopyrrole building blocks for solution-processable organic solar cells with an impressive open-circuit voltage.

    PubMed

    Patil, Hemlata; Zu, Wang Xi; Gupta, Akhil; Chellappan, Vijila; Bilic, Ante; Sonar, Prashant; Rananaware, Anushri; Bhosale, Sidhanath V; Bhosale, Sheshanath V

    2014-11-21

    A novel solution-processable non-fullerene electron acceptor 6,6'-(5,5'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione) (DPP1) based on fluorene and diketopyrrolopyrrole conjugated moieties was designed, synthesized and fully characterized. DPP1 exhibited excellent solubility and high thermal stability which are essential for easy processing. Upon using DPP1 as an acceptor with the classical electron donor poly(3-hexylthiophene), solution processable bulk-heterojunction solar cells afforded a power conversion efficiency of 1.2% with a high open-circuit voltage (1.1 V). As per our knowledge, this value of open circuit voltage is one of the highest values reported so far for a bulk-heterojunction device using DPP1 as a non-fullerene acceptor.

  17. Simultaneous control of phenanthrene and drought by dual exposure system: the degree of synergistic interactions in springtails was exposure dependent.

    PubMed

    Schmidt, Stine N; Holmstrup, Martin; Damgaard, Christian; Mayer, Philipp

    2014-08-19

    Organisms in the environment are exposed to multiple stressors. However, for terrestrial invertebrates, it remains difficult to study the effects of combined stressors under well-defined exposure conditions. Thus, the current study develops a new dual exposure system for the simultaneous and independent control of chemical and drought exposure in bioassays with terrestrial organisms: Passive dosing from silicone controlled the chemical activity of phenanthrene (chemical stress), while saline solutions controlled the water activity (drought stress) in the closed exposure system. The dual exposure system was then applied in a full factorial experiment with seven exposure levels (7(2)), which aimed at determining the combined effects of phenanthrene and drought on the survival of the terrestrial springtail Folsomia candida after 7 d exposure. Fitting an "independent action" model to the complete data set revealed statistically significant synergy between phenanthrene and drought (p < 0.0001). However, the degree of synergy was exposure dependent with some synergy at higher and only minor synergy at lower exposure levels. This emphasizes the need for taking exposure levels into account when extrapolating synergy observations from (eco)toxicological studies done at high exposure levels. PMID:24998522

  18. A fusant of Sphingomonas sp. GY2B and Pseudomonas sp. GP3A with high capacity of degrading phenanthrene.

    PubMed

    Lu, Jing; Guo, Chuling; Li, Jing; Zhang, Hui; Lu, Guining; Dang, Zhi; Wu, Renren

    2013-09-01

    A fusant strain F14 with high biodegradation capability of phenanthrene was obtained by protoplast fusion between Sphingomonas sp. GY2B (GenBank DQ139343) and Pseudomonas sp. GP3A (GenBank EU233280). F14 was screened and identified from 39 random fusants by antibiotic tests, scanning electron microscope (SEM) and randomly amplified polymorphic DNA (RAPD). The result of SEM analysis demonstrated that the cell shape of fusant F14 different from parental strains. RAPD analysis of 5 primers generated a total of 70 bands. The genetic similarity indices between F14 and parental strains GY2B and GP3A were 27.9 and 34.6 %, respectively. F14 could rapidly degrade phenanthrene within 24 h, and the degradation efficiency was much better than GY2B and GP3A. GC-MS analysis of metabolites of phenanthrene degradation indicated F14 had a different degradation pathway from GY2B. Furthermore, the fusant strain F14 had a wider adaptation of temperatures (25-36 °C) and pH values (6.5-9.0) than GY2B. The present study indicated that fusant strain F14 could be an effective and environment-friendly bacterial strain for PAHs bioremediation. PMID:23529357

  19. [Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

    PubMed

    Xie, Li; Chen, Ben-shou; Zhang, Jin-zhong; Lu, Song; Jiang, Tao

    2016-03-15

    The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content. PMID:27337897

  20. [Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

    PubMed

    Xie, Li; Chen, Ben-shou; Zhang, Jin-zhong; Lu, Song; Jiang, Tao

    2016-03-15

    The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content.

  1. A laboratory feasibility study on a new electrokinetic nutrient injection pattern and bioremediation of phenanthrene in a clayey soil.

    PubMed

    Xu, Wei; Wang, Cuiping; Liu, Haibin; Zhang, Zhiyuan; Sun, Hongwen

    2010-12-15

    Electrokinetic (EK) injection has recently been proposed to supply nutrients and electron acceptors in bioremediation of low permeable soils. However, effective pH control and uniform injection of inorganic ions have yet to be developed. The present study investigated a new EK injection pattern, which combined electrolyte circulation and electrode polarity reversal on a clayey soil. Soil pH could be controlled ranging from 7.0 to 7.6 by circulating the mixed electrolyte at a suitable rate (800 mL/h in this study) without any buffer. Ammonium and nitrate ions were distributed more uniformly in soil by electrode polarity reversal. The developed electrokinetic injection technology was applied primarily in bioremediation of phenanthrene contaminated soil. Over 80% of the initial 200mg/kg phenanthrene in soil could be removed in 20 d, and greater phenanthrene removal was achieved using electrode polarity reversal. Hence, the present study provides a promising electrokinetic injection technology for bioremediation of contaminated soils. PMID:20870357

  2. Magnetic adsorbents for the removal of Hg (II) and phenanthrene from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Isari, Ekavi; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.; Werner, David

    2015-04-01

    Activated carbon (AC) acts as a strong binding agent that lowers the pollutant concentration and, thus its toxicity. Another promising sorbent material in environmental applications is biochar (BC) which is obtained from the incomplete combustion of carbon-rich biomass under oxygen-limited conditions. Both of these materials could be used as soil or sediment amendments that would lower the toxicity in the aqueous phase. A draw back of this technique is that although the pollutant will remain non- bioavailable for many years being sorbed into these sorbents, it actually stays into the system. The objective of this study was (a) to synthesize a magnetic powdered activated carbon (AC/Fe) and magnetic powdered biochar (BC/Fe) produced from commercial AC1 and AC2 samples and biochar respectively and (b) to evaluate the potential use of AC/Fe and BIO/Fe to remove aqueous Hg (II) or phenanthrene while being magnetically recoverable. The BC was produced from olive pomace. The surface area, the pore volume, and the average pore size of each sorbent were determined using gas (N2) adsorption-desorption cycles and the Brunauer, Emmett, and Teller (BET) equation. Isotherms with 30 adsorption and 20 desorption points were conducted at liquid nitrogen temperature (77K). Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. For both AC/Fe, surface area measurements resulted in 66% those of corresponding AC. For BC/Fe, the surface area was 82% that of BC. Batch experiments with all sorbent samples and mercury solutions were conducted at room temperature (25oC) and at pH 5 in order to compare the sorption properties of the materials. Similar tests were performed with phenanthrene solutions. Based on mercury isotherm data, AC/Fe and BC/Fe are effective sorbents but with lower sorption capacity compared to the initial materials (50-75% lower). All these properties point to promising materials that can effectively be used for in

  3. Complete genome sequence of the phenanthrene-degrading soil bacterium Delftia acidovorans Cs1-4

    SciTech Connect

    Shetty, Ameesha R.; de Gannes, Vidya; Obi, Chioma C.; Lucas, Susan; Lapidus, Alla; Cheng, Jan-Fang; Goodwin, Lynne A.; Pitluck, Samuel; Peters, Linda; Mikhailova, Natalia; Teshima, Hazuki; Han, Cliff; Tapia, Roxanne; Land, Miriam; Hauser, Loren J.; Kyrpides, Nikos; Ivanova, Natalia; Pagani, Ioanna; Chain, Patrick S. G.; Denef, Vincent J.; Woyke, Tanya; Hickey, William J.

    2015-08-15

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental pollutants and microbial biodegradation is an important means of remediation of PAH-contaminated soil. Delftia acidovorans Cs1-4 (formerly Delftia sp. Cs1-4) was isolated by using phenanthrene as the sole carbon source from PAH contaminated soil in Wisconsin. Its full genome sequence was determined to gain insights into a mechanisms underlying biodegradation of PAH. Three genomic libraries were constructed and sequenced: an Illumina GAii shotgun library (916,416,493 reads), a 454 Titanium standard library (770,171 reads) and one paired-end 454 library (average insert size of 8 kb, 508,092 reads). The initial assembly contained 40 contigs in two scaffolds. The 454 Titanium standard data and the 454 paired end data were assembled together and the consensus sequences were computationally shredded into 2 kb overlapping shreds. Illumina sequencing data was assembled, and the consensus sequence was computationally shredded into 1.5 kb overlapping shreds. Gaps between contigs were closed by editing in Consed, by PCR and by Bubble PCR primer walks. A total of 182 additional reactions were needed to close gaps and to raise the quality of the finished sequence. The final assembly is based on 253.3 Mb of 454 draft data (averaging 38.4 X coverage) and 590.2 Mb of Illumina draft data (averaging 89.4 X coverage). The genome of strain Cs1-4 consists of a single circular chromosome of 6,685,842 bp (66.7 %G+C) containing 6,028 predicted genes; 5,931 of these genes were protein-encoding and 4,425 gene products were assigned to a putative function. Genes encoding phenanthrene degradation were localized to a 232 kb genomic island (termed the phn island), which contained near its 3’ end a bacteriophage P4-like integrase, an enzyme often associated with chromosomal integration of mobile genetic elements. Other biodegradation pathways reconstructed from the genome sequence included: benzoate (by the acetyl-CoA pathway

  4. Complete genome sequence of the phenanthrene-degrading soil bacterium Delftia acidovorans Cs1-4

    DOE PAGES

    Shetty, Ameesha R.; de Gannes, Vidya; Obi, Chioma C.; Lucas, Susan; Lapidus, Alla; Cheng, Jan-Fang; Goodwin, Lynne A.; Pitluck, Samuel; Peters, Linda; Mikhailova, Natalia; et al

    2015-08-15

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental pollutants and microbial biodegradation is an important means of remediation of PAH-contaminated soil. Delftia acidovorans Cs1-4 (formerly Delftia sp. Cs1-4) was isolated by using phenanthrene as the sole carbon source from PAH contaminated soil in Wisconsin. Its full genome sequence was determined to gain insights into a mechanisms underlying biodegradation of PAH. Three genomic libraries were constructed and sequenced: an Illumina GAii shotgun library (916,416,493 reads), a 454 Titanium standard library (770,171 reads) and one paired-end 454 library (average insert size of 8 kb, 508,092 reads). The initial assembly contained 40 contigs inmore » two scaffolds. The 454 Titanium standard data and the 454 paired end data were assembled together and the consensus sequences were computationally shredded into 2 kb overlapping shreds. Illumina sequencing data was assembled, and the consensus sequence was computationally shredded into 1.5 kb overlapping shreds. Gaps between contigs were closed by editing in Consed, by PCR and by Bubble PCR primer walks. A total of 182 additional reactions were needed to close gaps and to raise the quality of the finished sequence. The final assembly is based on 253.3 Mb of 454 draft data (averaging 38.4 X coverage) and 590.2 Mb of Illumina draft data (averaging 89.4 X coverage). The genome of strain Cs1-4 consists of a single circular chromosome of 6,685,842 bp (66.7 %G+C) containing 6,028 predicted genes; 5,931 of these genes were protein-encoding and 4,425 gene products were assigned to a putative function. Genes encoding phenanthrene degradation were localized to a 232 kb genomic island (termed the phn island), which contained near its 3’ end a bacteriophage P4-like integrase, an enzyme often associated with chromosomal integration of mobile genetic elements. Other biodegradation pathways reconstructed from the genome sequence included: benzoate (by the acetyl

  5. Complete genome sequence of the phenanthrene-degrading soil bacterium Delftia acidovorans Cs1-4.

    PubMed

    Shetty, Ameesha R; de Gannes, Vidya; Obi, Chioma C; Lucas, Susan; Lapidus, Alla; Cheng, Jan-Fang; Goodwin, Lynne A; Pitluck, Samuel; Peters, Linda; Mikhailova, Natalia; Teshima, Hazuki; Han, Cliff; Tapia, Roxanne; Land, Miriam; Hauser, Loren J; Kyrpides, Nikos; Ivanova, Natalia; Pagani, Ioanna; Chain, Patrick S G; Denef, Vincent J; Woyke, Tanya; Hickey, William J

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental pollutants and microbial biodegradation is an important means of remediation of PAH-contaminated soil. Delftia acidovorans Cs1-4 (formerly Delftia sp. Cs1-4) was isolated by using phenanthrene as the sole carbon source from PAH contaminated soil in Wisconsin. Its full genome sequence was determined to gain insights into a mechanisms underlying biodegradation of PAH. Three genomic libraries were constructed and sequenced: an Illumina GAii shotgun library (916,416,493 reads), a 454 Titanium standard library (770,171 reads) and one paired-end 454 library (average insert size of 8 kb, 508,092 reads). The initial assembly contained 40 contigs in two scaffolds. The 454 Titanium standard data and the 454 paired end data were assembled together and the consensus sequences were computationally shredded into 2 kb overlapping shreds. Illumina sequencing data was assembled, and the consensus sequence was computationally shredded into 1.5 kb overlapping shreds. Gaps between contigs were closed by editing in Consed, by PCR and by Bubble PCR primer walks. A total of 182 additional reactions were needed to close gaps and to raise the quality of the finished sequence. The final assembly is based on 253.3 Mb of 454 draft data (averaging 38.4 X coverage) and 590.2 Mb of Illumina draft data (averaging 89.4 X coverage). The genome of strain Cs1-4 consists of a single circular chromosome of 6,685,842 bp (66.7 %G+C) containing 6,028 predicted genes; 5,931 of these genes were protein-encoding and 4,425 gene products were assigned to a putative function. Genes encoding phenanthrene degradation were localized to a 232 kb genomic island (termed the phn island), which contained near its 3' end a bacteriophage P4-like integrase, an enzyme often associated with chromosomal integration of mobile genetic elements. Other biodegradation pathways reconstructed from the genome sequence included: benzoate (by the acetyl-CoA pathway

  6. Electrochemical Interrogation of G3-Poly(propylene thiophenoimine) Dendritic Star Polymer in Phenanthrene Sensing.

    PubMed

    Makelane, Hlamulo R; Tovide, Oluwakemi; Sunday, Christopher E; Waryo, Tesfaye; Iwuoha, Emmanuel I

    2015-09-03

    A novel dendritic star-copolymer, generation 3 poly(propylene thiophenoimine) (G3PPT)-co-poly(3-hexylthiophene) (P3HT) star co-polymer on gold electrode (i.e., Au|G3PPT-co-P3HT) was used as a sensor system for the determination of phenanthrene (PHE). The G3PPT-co-P3HT star co-polymer was synthesized via in situ electrochemical co-polymerization of generation 3 poly (propylene thiophenoimine) and poly (3-hexylthiophene) on gold electrode. 1HNMR spectroscopy was used to determine the regioregularity of the polymer composites, whereas Fourier transform infrared spectroscopy and scanning electron microscopy were used to study their structural and morphological properties. Au|G3PPT-co-P3HT in the absence of PHE, exhibited reversible electrochemistry attributable to the oligo (thiophene) 'pendants' of the dendrimer. PHE produced an increase in the voltammetric signals (anodic currents) due to its oxidation on the dendritic material to produce catalytic current, thereby suggesting the suitability of the Au|G3PPT-co-P3HT electrode as a PHE sensor. The electrocatalysis of PHE was made possible by the rigid and planar oligo-P3HT species (formed upon the oxidation of the oligo (thiophene) pendants of the star-copolymer), which allowed the efficient capture (binding) and detection (electrocatalytic oxidation) of PHE molecules.

  7. Fullerene-associated phenanthrene contributes to bioaccumulation but is not toxic to fish.

    PubMed

    Hu, Xialin; Li, Jing; Shen, Mohai; Yin, Daqiang

    2015-05-01

    The present study investigated the effects of aqueous fullerene suspensions (nC60 ) on the bioavailability and toxicity of phenanthrene (Phe) to junior carp (Cyprinus carpio). Bioaccumulation factors (BAFs) were calculated based on total as well as free concentrations of Phe. Equal BAF values were obtained with and without nC60 based on the total concentrations, whereas greater BAFs were found in the presence of nC60 when free Phe concentrations were applied. The results demonstrated that nC60 could act as a contaminant carrier to facilitate Phe bioaccumulation. The concentration-response relationship of induced hepatic 7-ethoxysorufin-O-deethylase activity was established in regard to the total and free concentrations of aqueous Phe solutions as well as the body residues. The concentration-response curves were reliant on the nC60 concentration when the total concentration of Phe was employed as a variable but were independent of nC60 presence when free concentration or body residue was employed as a variable, implying that the latter 2 parameters were more accurate in evaluating biological effects. Particles of C60 were mostly distributed in fish liver and intestines, which indicated the primary routine of uptake was through ingestion. Approximately 22% to 100% of the Phe-nC60 complex contributed to the bioaccumulation, whereas the complex did not contribute to the toxicity.

  8. Synergistic effects of inorganic salt and surfactant on phenanthrene removal from aqueous solution by sediment.

    PubMed

    Zhang, Xiaoyan; Wu, Yaoguo; Hu, Sihai; Lu, Cong

    2014-01-01

    The economic and effective application of surfactant enhanced remediation (SER) technology in a sediment-freshwater/saline water system was investigated by batch method using the combined effects of inorganic salt (sodium chloride, NaCl) and anionic surfactant (sodium dodecylbenzene sulfonate (SDBS)) on phenanthrene (PHE) removal via sorption by sediment. In all cases, PHE sorption followed a linear equation and partition as the main mechanism for PHE removal from aqueous solution. Separate addition of SDBS (2 mmol L(-1)) and NaCl (2-100 mmol L(-1)) moderately enhanced PHE removal, while with their combined addition the enhancement was substantial, and the removal efficiency achieved a peak of 92.8%. The combined effect expressed a synergy, and the sorption enhancement increased by factors of 2.7, 3.2 and 3.4 when compared with the sum of the separate entities at elevated salinity. This was because the sorbed SDBS, with increasing amount and a high packing conformation at elevated salinity, outcompeted aqueous SDBS for PHE partition. Moreover, a combination of 2 mmol L(-1) SDBS and 2 mmol L(-1) NaCl was optimal for PHE removal. Therefore, SER technology appears more effective for PHE removal in saline water than in freshwater, and preliminary water quality monitoring is essential for economic and efficient SER application. PMID:25353936

  9. Removal of low concentrations of phenanthrene, fluoranthene and pyrene from urban wastewater by membrane bioreactors technology.

    PubMed

    González-Pérez, Daniel M; Garralón, Gloria; Plaza, Fidel; Pérez, Jorge I; Moreno, Begoña; Gómez, Miguel A

    2012-01-01

    The fate and removal of phenanthrene (Phen), fluoranthene (F) and pyrene (Py) in urban wastewater treatment by membrane bioreactor (MBR) with low influent polycyclic aromatic hydrocarbons (PAHs) concentration were studied. A full experimental ultrafiltration MBR with a pre-denitrification configuration and capacity to treat 20 m(3)/d was employed. The system was operated with real urban wastewater, to which a concentration of PAHs was added. A constant purge was achieved in order to obtain 12 d of sludge retention time and the hydraulic retention time was 34 h. Concentration of PAHs was determined by Gas Chromatography and Mass Spectrometry with Twister, and mass balance on the MBR system were calculated. Data were supplemented by respirometric analyses, isolation of PAHs degrading microorganisms and bench-scale experiments. All effluent samples presented concentrations of PAHs, with removal levels of 91% and 92% for F and Py respectively, while for Phen performance did not surpass 82%. In spite of the high hydrophobicity of the tested compounds, their accumulation in the biomass was scarce and the sludge presented a low PAH concentration. The experiments reveal that PAHs removal is mainly due to air stripping, with biodegradation and adsorption making an insignificant contribution.

  10. Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination.

    PubMed

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Sheng, Yuehui; Kang, Fuxing; Waigi, Michael Gatheru

    2015-12-01

    Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil.

  11. Morphological and physiological responses of maize (Zea mays) exposed to sand contaminated by phenanthrene.

    PubMed

    Dupuy, Joan; Ouvrard, Stéphanie; Leglize, Pierre; Sterckeman, Thibault

    2015-04-01

    Phytoremediation is promising, but depends on clearly understanding contaminants' impact on plant functioning. We therefore focused on the impact of polycyclic aromatic hydrocarbons (PAH) on cultivated plants and understanding the impact of phenanthrene (PHE) on maize functioning (Zea mays). Cultivation was conducted under controlled conditions on artificially contaminated sand with PHE levels increasing from 50 to 750 mg PHE kg(-1). After four weeks, plants exposed to levels above 50 mg PHE kg(-1) presented decreased biomasses and reduced photosynthetic activity. These modifications were associated with higher biomass allocations to roots and lower ones to stems. The leaf biomass proportion was similar, with thinner blades than controls. PHE-exposed plant showed modified root architecture, with fewer roots of 0.2 and 0.4 mm in diameter. Leaves were potassium-deplete, but calcium, phosphorus, magnesium and zinc-enriched. Their content in nitrogen, iron, sulfur and manganese was unaffected. These responses resembled those of water-stress, although water contents in plant organs were not affected by PHE and water supply was not limited. They also indicated a possible perturbation of both nutritional functioning and photosynthesis.

  12. Titanium dioxide nanoparticles as carrier facilitate bioaccumulation of phenanthrene in marine bivalve, ark shell (Scapharca subcrenata).

    PubMed

    Tian, Shengyan; Zhang, Yaodan; Song, Chunzheng; Zhu, Xiaoshan; Xing, Baoshan

    2014-09-01

    To evaluate the impact of titanium dioxide nanoparticles (nTiO2) on the uptake of hydrophobic organic chemicals by marine bivalves, we conducted a comparative bioaccumulation study by exposing clam, Scapharca subcrenata, to phenanthrene (Phe) in the presence and absence of nTiO2. The large surface area of nTiO2 resulted in adsorption of co-existing Phe in aqueous solution to form nTiO2-Phe complexes. Accumulation of nTiO2 was not observed in clams at exposed concentration (500 μg/L) in this study. However, enhanced uptake of Phe by clams was observed in the presence of nTiO2, with ku and BAFs values being 2 and 1.7 times higher than that of Phe alone, respectively. The enhanced uptake can be explained by ingestion of nTiO2-Phe complexes into the gut and subsequent desorption of Phe there. Therefore, nTiO2 as a carrier facilitated the uptake of Phe by marine bivalves.

  13. Influence of a dispersant on the bioaccumulation of phenanthrene by topsmelt (Atherinops affinis).

    PubMed

    Mielbrecht, E E; Wolfe, M F; Tjeerdema, R S; Sowby, M L

    2005-05-01

    Chemical dispersants enhance oil spill dispersion by forming water-accommodated micelles with oil droplets. However, how dispersants alter bioavailability and subsequent bioaccumulation of hydrocarbons is not well understood. Thus, the goal was to investigate the influence of a chemical dispersant on the disposition (uptake, biotransformation, and depuration) of a model hydrocarbon, [14C]-phenanthrene ([14C]PHN), by larval topsmelt (Atherinops affinis). Exposure was via aqueous-only or combined dietary and aqueous routes from a water-accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO) or a WAF of Corexit 9527-dispersed PBCO (DO). Trophic transfer was measured by incorporating into exposure media both a rotifer (Brachionus plicatilis) as food for the fish and a phytoplankton (Isochrysis galbana) as food for the rotifers. Short-term (4 h) bioconcentration of PHN was significantly decreased in topsmelt when oil was treated with dispersant (P < 0.05), but differences diminished after 12 h. When trophic transfer was incorporated, PHN accumulation was initially delayed but after 12 h attained similar levels. Dispersant use also significantly decreased the proportion of biotransformed PHN (as 9-phenanthrylsulfate) produced by topsmelt (P < 0.05). However, overall PHN depuration was not affected by dispersant use. Thus, chemical dispersant use in oil spill response may reduce short-term uptake but not long-term accumulation of hydrocarbons such as PHN in pelagic fish. PMID:15814309

  14. Role of structure and microporosity in phenanthrene sorption by natural and engineered organic matter.

    PubMed

    Han, Lanfang; Sun, Ke; Jin, Jie; Wei, Xin; Xia, Xinghui; Wu, Fengchang; Gao, Bo; Xing, Baoshan

    2014-10-01

    Natural sorbents including one humic acid (HA), humins (HMs), nonhydrolyzable carbons (NHCs), and engineered sorbents (biochars) were subject to bleaching to selectively remove a fraction of aromatic C. The structural properties and sorption isotherm data of phenanthrene (Phen) by original and bleached sorbents were obtained. Significant correlations between Phen Koc values by all sorbents and their organic carbon (OC)-normalized CO2 cumulative surface area (CO2-SA/OC) suggested that nanopore-filling mechanism could dominate Phen sorption. After bleaching, natural sorbents still contained large amounts of aromatic C, which are resistant to bleaching, suggesting that they are derived from condensed or nonbiodegradable organic matter (OM). After eliminating the effect of aromatic C remaining in the bleached samples, a general trend of increasing CO2-SA/OC of natural sorbents with increasing aliphaticity was observed, suggesting that nanopores of natural sorbents are partially derived from their aliphatic moieties. Conversely, positive relationships between CO2-SA/OC or Phen logKoc of engineered sorbents and their aromaticity indicated the aromatic structures of engineered sorbents primarily contribute to their nanopores and dominate their sorption of HOCs. Therefore, this study clearly demonstrated that the role of structure and microporosity in Phen sorption is dependent on the sources of sorbents. PMID:25184695

  15. Biodegradation of pyrene and phenanthrene by bacterial consortium and evaluation of role of surfactant.

    PubMed

    Kumari, B; Rajput, S; Gaur, P; Singh, S N; Singh, D P

    2014-12-24

    High molecular weight poly aromatic hydrocarbons (HMW PAHs) are well known for their hydrophobicity and they get strongly adsorbed onto the soil particles. Generally, surfactants facilitate the biodegradation of PAH by enhancing their solubility and desorption of hydrophobic compounds from soil particles. To investigate the role of synthetic surfactant in biodegradation of PAHs, two bacterial strains BP10 and P2 were incubated in soil spiked with pyrene and phenantherene (100 μg g-1of soil each) in isolation and in combination with/without Tween 80. After 14 days of incubation, pyrene and phenantherene were degraded by a combination of BP10 and P2 to the extent of 98% and 99%, respectively. Addition of tween 80 reduced the degradation of pyrene and phenantherene by 35 and 10%, respectively. Biosurfactant produced by selected strains i.e. BP10 and P2 could enhance desorption of pyrene (100 μg g-1of soil) by about 27% and 12%, respectively. However, desorption activity was relatively higher (32 and 29%, respectively) in case of phenanthrene (100 μg g-1of soil) from the spiked soil. Present study showed that in spite of additional chemical surfactant, bioaugmentation of highly petroleum hydrocarbon degrading bacterial combination was very effective in boosting the bioremediation of PAHs- contaminated sites.

  16. Chronic toxicity of phenanthrene to the marine polychaete worm, Nereis (Neanthes) arenaceodentata

    SciTech Connect

    Emery, V.L. Jr.; Dillon, T.M.

    1996-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in the environment. While environmental concentrations are generally below acutely, lethal levels, chronic, low level exposures may result in subtle sublethal effects. PAHs accumulate in bottom sediments and may represent a hazard to the benthos. Polychaetes are important members of this community. The objective of this study is to evaluate the chronic sublethal effects of one PAH, phenanthrene (PHN), on the polychaete worm, Nereis arenaceodentata. PHN was selected because of its high toxicity to marine invertebrates relative to other PAHs. The response of bivalves to heavy metals and other toxins has usually been determined by observing valve position. Since mussels close their valves to avoid noxious stimuli, experimental delivery of chemicals is uncertain. To obtain constant results. Preston employed plastic spacers to hold the valves apart. This obviates the observation of valve position as an index of response, and some other method is required. Electromyography of intact mussels is one such index, and is shown to be a simple, effective and quantitative measurement of activity. Experiments are reported on the effects of added mercury on salt water and fresh water species. Parts of this Nvork have appeared in brief form.

  17. Study of phenanthrene utilizing bacterial consortia associated with cowpea (Vigna unguiculata) root nodules.

    PubMed

    Sun, Ran; Crowley, David E; Wei, Gehong

    2015-02-01

    Many legumes have been selected as model plants to degrade organic contaminants with their special associated rhizosphere microbes in soil. However, the function of root nodules during microbe-assisted phytoremediation is not clear. A pot study was conducted to examine phenanthrene (PHE) utilizing bacteria associated with root nodules and the effects of cowpea root nodules on phytoremediation in two different types of soils (freshly contaminated soil and aged contaminated soil). Cowpea nodules in freshly-contaminated soil showed less damage in comparison to the aged-contaminated soil, both morphologically and ultra-structurally by scanning electron microscopy. The study of polycyclic aromatic hydrocarbon (PAH) attenuation conducted by high performance liquid chromatography revealed that more PAH was eliminated from liquid culture around nodulated roots than nodule-free roots. PAH sublimation and denaturation gradient gel electrophoresis were applied to analyze the capability and diversity of PAH degrading bacteria from the following four parts of rhizo-microzone: bulk soil, root surface, nodule surface and nodule inside. The results indicated that the surface and inside of cowpea root nodules were colonized with bacterial consortia that utilized PHE. Our results demonstrated that root nodules not only fixed nitrogen, but also enriched PAH-utilizing microorganisms both inside and outside of the nodules. Legume nodules may have biotechnological values for PAH degradation. PMID:25601371

  18. Mechanisms regulating bioavailability of phenanthrene sorbed on a peat soil-origin humic substance.

    PubMed

    Yang, Yu; Shu, Liang; Wang, Xilong; Xing, Baoshan; Tao, Shu

    2012-07-01

    The organic matter-mineral complex plays an important role in regulating the fate of hydrophobic organic compounds (HOCs) in the environment. In the present study, the authors investigated the microbial bioavailability of phenanthrene (PHE) sorbed on the original and demineralized humic acids (HAs) and humin (HM) that were sequentially extracted from a peat soil. Demineralization treatment dramatically decreased the 720-h mineralized percentage of HM-sorbed PHE from 42.5 ± 2.6% to 3.4 ± 1.3%, whereas the influence of this treatment on the biodegradability of HA-associated PHE was much lower. Degradation kinetics of HA- and HM-sorbed PHE showed that its initial degradation rate was negatively correlated with the aromatic carbon content of humic substances (p<0.05). This was attributed to the strong interactions between PHE and the aromatic components of humic substances, which hampered its release and subsequent biodegradation. The 720-h mineralized percentage of PHE was inversely correlated with the estimated thickness of the organic matter layer at the surfaces of HAs and HMs. Therefore, in a relatively long term, diffusion of PHE within the organic matter layer could be an important factor that may limit the bioavailability of PHE to bacteria. Results of the present study highlight the molecular-scaled mechanisms governing bioavailability of PHE sorbed on humic substances.

  19. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation.

    PubMed

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  20. Quantifying the dynamic fluorescence quenching of phenanthrene and ofloxacin by dissolved humic acids.

    PubMed

    Wang, Lin; Liang, Ni; Li, Hao; Yang, Yu; Zhang, Di; Liao, Shaohua; Pan, Bo

    2015-01-01

    Fluorescence quenching includes dynamic and static quenching, and both processes can alter the behavior and reactivity of the fluorescer. However, dynamic quenching is seldom quantified. This study combined dialysis equilibrium and fluorescence quenching methods to compare the contribution of dynamic and static quenching. The results indicate that phenanthrene (PHE)-DHA binding increased with DHA hydrophobicity, while ofloxacin (OFL)-DHA interaction showed the opposite effect. For PHE,the contribution of dynamic quenching to the overall fluorescence quenching was in the range of 50%~82% and decreased to 11%~58% with increased DHA hydrophobicity. However, OFL dynamic quenching increased from 2%~27% to 31%~61% with DHA hydrophobicity. Combining the results using model chemicals, we concluded that the carboxyl groups in DHA might be the primary components for PHE dynamic quenching and might be responsible for both dynamic and static quenching of OFL. Extensive study is needed to explore the quantitative relationship of dynamic quenching and chemical/DHA properties.

  1. Morphological and physiological responses of maize (Zea mays) exposed to sand contaminated by phenanthrene.

    PubMed

    Dupuy, Joan; Ouvrard, Stéphanie; Leglize, Pierre; Sterckeman, Thibault

    2015-04-01

    Phytoremediation is promising, but depends on clearly understanding contaminants' impact on plant functioning. We therefore focused on the impact of polycyclic aromatic hydrocarbons (PAH) on cultivated plants and understanding the impact of phenanthrene (PHE) on maize functioning (Zea mays). Cultivation was conducted under controlled conditions on artificially contaminated sand with PHE levels increasing from 50 to 750 mg PHE kg(-1). After four weeks, plants exposed to levels above 50 mg PHE kg(-1) presented decreased biomasses and reduced photosynthetic activity. These modifications were associated with higher biomass allocations to roots and lower ones to stems. The leaf biomass proportion was similar, with thinner blades than controls. PHE-exposed plant showed modified root architecture, with fewer roots of 0.2 and 0.4 mm in diameter. Leaves were potassium-deplete, but calcium, phosphorus, magnesium and zinc-enriched. Their content in nitrogen, iron, sulfur and manganese was unaffected. These responses resembled those of water-stress, although water contents in plant organs were not affected by PHE and water supply was not limited. They also indicated a possible perturbation of both nutritional functioning and photosynthesis. PMID:25496734

  2. Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene

    NASA Astrophysics Data System (ADS)

    Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

    2014-06-01

    Beta-cyclodextrin (β-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, β-CD and electrospun CA nanofibers were modified so as to be azide-β-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of β-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

  3. Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene

    SciTech Connect

    Fronzoni, Giovanna; Baseggio, Oscar; Stener, Mauro; Hua, Weijie; Tian, Guangjun; Luo, Yi; Apicella, Barbara; Alfé, Michela; Simone, Monica de; Kivimäki, Antti; Coreno, Marcello

    2014-07-28

    We performed a combined experimental and theoretical study of the C1s Near-Edge X-ray Absorption Fine-Structure (NEXAFS) spectroscopy and X-ray Photoelectron Spectroscopy in the gas phase of two polycyclic aromatic hydrocarbons (phenanthrene and coronene), typically formed in combustion reactions. In the NEXAFS of both molecules, a double-peak structure appears in the C1s → LUMO region, which differ by less than 1 eV in transition energies. The vibronic coupling is found to play an important role in such systems. It leads to weakening of the lower-energy peak and strengthening of the higher-energy one because the 0 − n (n > 0) vibrational progressions of the lower-energy peak appear in nearly the same region of the higher-energy peak. Vibrationally resolved theoretical spectra computed within the Frank-Condon (FC) approximation and linear coupling model agree well with the high-resolution experimental results. We find that FC-active normal modes all correspond to in-plane vibrations.

  4. Effects of cowpea (Vigna unguiculata) root mucilage on microbial community response and capacity for phenanthrene remediation.

    PubMed

    Sun, Ran; Belcher, Richard W; Liang, Jianqiang; Wang, Li; Thater, Brian; Crowley, David E; Wei, Gehong

    2015-07-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is normally limited by their low solubility and poor bioavailability. Prior research suggests that biosurfactants are synthesized as intermediates during the production of mucilage at the root tip. To date the effects of mucilage on PAH degradation and microbial community response have not been directly examined. To address this question, our research compared 3 cowpea breeding lines (Vigna unguiculata) that differed in mucilage production for their effects on phenanthrene (PHE) degradation in soil. The High Performance Liquid Chromatography results indicated that the highest PHE degradation rate was achieved in soils planted with mucilage producing cowpea line C1, inoculated with Bradyrhizobium, leading to 91.6% PHE disappearance in 5 weeks. In root printing tests, strings treated with mucilage and bacteria produced larger clearing zones than those produced on mucilage treated strings with no bacteria or bacteria inoculated strings. Experiments with 14C-PHE and purified mucilage in soil slurry confirmed that the root mucilage significantly enhanced PHE mineralization (82.7%), which is 12% more than the control treatment without mucilage. The profiles of the PHE degraders generated by Denaturing gradient gel electrophoresis suggested that cowpea C1, producing a high amount of root mucilage, selectively enriched the PHE degrading bacteria population in rhizosphere. These findings indicate that root mucilage may play a significant role in enhancing PHE degradation and suggests that differences in mucilage production may be an important criterion for selection of the best plant species for use in phytoremediation of PAH contaminated soils. PMID:26141877

  5. Effects of cowpea (Vigna unguiculata) root mucilage on microbial community response and capacity for phenanthrene remediation.

    PubMed

    Sun, Ran; Belcher, Richard W; Liang, Jianqiang; Wang, Li; Thater, Brian; Crowley, David E; Wei, Gehong

    2015-07-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is normally limited by their low solubility and poor bioavailability. Prior research suggests that biosurfactants are synthesized as intermediates during the production of mucilage at the root tip. To date the effects of mucilage on PAH degradation and microbial community response have not been directly examined. To address this question, our research compared 3 cowpea breeding lines (Vigna unguiculata) that differed in mucilage production for their effects on phenanthrene (PHE) degradation in soil. The High Performance Liquid Chromatography results indicated that the highest PHE degradation rate was achieved in soils planted with mucilage producing cowpea line C1, inoculated with Bradyrhizobium, leading to 91.6% PHE disappearance in 5 weeks. In root printing tests, strings treated with mucilage and bacteria produced larger clearing zones than those produced on mucilage treated strings with no bacteria or bacteria inoculated strings. Experiments with 14C-PHE and purified mucilage in soil slurry confirmed that the root mucilage significantly enhanced PHE mineralization (82.7%), which is 12% more than the control treatment without mucilage. The profiles of the PHE degraders generated by Denaturing gradient gel electrophoresis suggested that cowpea C1, producing a high amount of root mucilage, selectively enriched the PHE degrading bacteria population in rhizosphere. These findings indicate that root mucilage may play a significant role in enhancing PHE degradation and suggests that differences in mucilage production may be an important criterion for selection of the best plant species for use in phytoremediation of PAH contaminated soils.

  6. Study of phenanthrene utilizing bacterial consortia associated with cowpea (Vigna unguiculata) root nodules.

    PubMed

    Sun, Ran; Crowley, David E; Wei, Gehong

    2015-02-01

    Many legumes have been selected as model plants to degrade organic contaminants with their special associated rhizosphere microbes in soil. However, the function of root nodules during microbe-assisted phytoremediation is not clear. A pot study was conducted to examine phenanthrene (PHE) utilizing bacteria associated with root nodules and the effects of cowpea root nodules on phytoremediation in two different types of soils (freshly contaminated soil and aged contaminated soil). Cowpea nodules in freshly-contaminated soil showed less damage in comparison to the aged-contaminated soil, both morphologically and ultra-structurally by scanning electron microscopy. The study of polycyclic aromatic hydrocarbon (PAH) attenuation conducted by high performance liquid chromatography revealed that more PAH was eliminated from liquid culture around nodulated roots than nodule-free roots. PAH sublimation and denaturation gradient gel electrophoresis were applied to analyze the capability and diversity of PAH degrading bacteria from the following four parts of rhizo-microzone: bulk soil, root surface, nodule surface and nodule inside. The results indicated that the surface and inside of cowpea root nodules were colonized with bacterial consortia that utilized PHE. Our results demonstrated that root nodules not only fixed nitrogen, but also enriched PAH-utilizing microorganisms both inside and outside of the nodules. Legume nodules may have biotechnological values for PAH degradation.

  7. Toxicity assessment of environmental pollutant phenanthrene in clam Venerupis philippinarum using oxidative stress biomarkers.

    PubMed

    Zhang, Hui; Pan, Luqing; Tao, Yanxia

    2014-03-01

    The objective of this study was to assess potential toxic effects of phenanthrene (PHE) on tissues of clam Venerupis philippinarum using parameters of antioxidant defenses and oxidative stress. Antioxidant biomarkers including ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), superoxide dismutase (SOD), and glutathione (GSH), as well as DNA damage and lipid peroxidation (LPO) in gills and digestive glands of V. philippinarum, were analyzed after a 1-, 3-, 6-, 10- and 15-day exposure to seawater containing PHE at concentrations of 2, 10, 50 μg/L. The results showed that the activity of most antioxidant enzymes was induced throughout the exposure period, and different trends were detected with time of exposure. The oxidative stress could be obviously caused in the gills and digestive glands under the experimental conditions. Overall, our results show that digestive glands are more sensitive to marine environmental stressors than gills, and GSH is proposed as potential useful biomarker as it showed good correlation with the target contaminant. This could provide useful information for toxic risk assessment of environmental pollutant PHE.

  8. Interaction of phenanthrene and potassium uptake by wheat roots: a mechanistic model

    PubMed Central

    2013-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic, mutagenic and toxic to both human and non-human organisms. Dietary intake of PAHs is a dominant route of exposure for the general population where food crops are a major source of dietary PAHs. Over 20% of main food crops contain PAHs that exceed the control limits in China. However, the mechanisms on PAH accumulation in crops are not well understood. Results Here we report the physiological mechanism of potassium (K+)-stimulated uptake of phenanthrene (PHE, a model PAH) in wheat. PHE uptake is stimulated by the external K+. The addition of blockers (tetraethlyammonium and barium) for K+ channels does not suppress the process, suggesting that K+ channels are not involved. The introduction of PHE and K+ elicits a much greater depolarization in root cell membrane potential than that of either PHE or K+. K+ activates the plasma membrane proton (H+)-ATPase in a K+-dependent manner. The pattern is quite similar to that in PHE uptake in the presence of K+. The external medium pH treated with PHE and K+ is higher than that with K+, and lower than that with PHE, indicating that H+ pump involves in the interaction between PHE and K+ uptake. Conclusions Therefore, it is concluded that a K+ influx/H+ efflux reaction is coupled with the transport of PHE into wheat root cells. Our results provide a novel insight into the PHE uptake by crop roots. PMID:24160457

  9. Brassinosteroids induce plant tolerance against phenanthrene by enhancing degradation and detoxification in Solanum lycopersicum L.

    PubMed

    Ahammed, Golam Jalal; Gao, Chun-Juan; Ogweno, Joshua Otieno; Zhou, Yan-Hong; Xia, Xiao-Jian; Mao, Wei-Hua; Shi, Kai; Yu, Jing-Quan

    2012-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are toxic to both plants and animals. The enhancement of plant tolerance and detoxification capacity is important for the plant-based remediation of PAHs. Therefore, we investigated the effects of 24-epibrassinolide (EBR) on the metabolism of a three-ringed PAH (phenanthrene-PHE) and subsequent stress tolerance in tomato (Solanum lycopersicum L.) plants. Exposure to PHE (300 μM) for 21 d significantly decreased biomass and net CO(2) assimilation (P(n)) but induced photoinhibition, malondialdehyde (MDA), H(2)O(2) and antioxidant enzymes. Obvious ultrastructural alterations were observed in the PHE-treated root tip cells. Importantly, the foliar application of EBR (0.1 μM) significantly increased biomass, P(n) and antioxidant enzyme activities but decreased MDA and H(2)O(2) compared with PHE alone and saved the root cells from severe damage. The expression of detoxification genes (CYP90b3, GSH1, GST1), reduced glutathione (GSH) content and glutathione S-transferase activity in the EBR+PHE-treated plants were higher than those of PHE alone. Additionally, lower levels of PHE residues in the roots were observed as a result of EBR+PHE treatment. Taken together, our results strongly suggest an enhanced and coordinated detoxification and degradation of PHE by EBR.

  10. Electrochemical Interrogation of G3-Poly(propylene thiophenoimine) Dendritic Star Polymer in Phenanthrene Sensing

    PubMed Central

    Makelane, Hlamulo R.; Tovide, Oluwakemi; Sunday, Christopher E.; Waryo, Tesfaye; Iwuoha, Emmanuel I.

    2015-01-01

    A novel dendritic star-copolymer, generation 3 poly(propylene thiophenoimine) (G3PPT)-co-poly(3-hexylthiophene) (P3HT) star co-polymer on gold electrode (i.e., Au|G3PPT-co-P3HT) was used as a sensor system for the determination of phenanthrene (PHE). The G3PPT-co-P3HT star co-polymer was synthesized via in situ electrochemical co-polymerization of generation 3 poly (propylene thiophenoimine) and poly (3-hexylthiophene) on gold electrode. 1HNMR spectroscopy was used to determine the regioregularity of the polymer composites, whereas Fourier transform infrared spectroscopy and scanning electron microscopy were used to study their structural and morphological properties. Au|G3PPT-co-P3HT in the absence of PHE, exhibited reversible electrochemistry attributable to the oligo (thiophene) ‘pendants’ of the dendrimer. PHE produced an increase in the voltammetric signals (anodic currents) due to its oxidation on the dendritic material to produce catalytic current, thereby suggesting the suitability of the Au|G3PPT-co-P3HT electrode as a PHE sensor. The electrocatalysis of PHE was made possible by the rigid and planar oligo-P3HT species (formed upon the oxidation of the oligo (thiophene) pendants of the star-copolymer), which allowed the efficient capture (binding) and detection (electrocatalytic oxidation) of PHE molecules. PMID:26404296

  11. Temperature-dependent sorption of naphthalene, phenanthrene, and pyrene to low organic carbon aquifer sediments

    USGS Publications Warehouse

    Piatt, J.J.; Backhus, D.A.; Capel, P.D.; Eisenreich, Steven J.

    1996-01-01

    Sorption experiments were conducted with naphthalene, phenanthrene, and pyrene on low organic carbon sediments at 4 and 26 ??C using batch and column techniques. Experimental controls ensured the absence of biologic and photolytic activity and colloid-free solution supernatants. Equilibrium distribution coefficients (K(d)) increased 1.1-1.6 times with a decrease in temperature of 22 ??C. Fraction instantaneous sorption (F) values did not change significantly with a decrease in temperature of 22 ??C. Desorption rate constants (k2) decreased 1.2-2.6 times with a decrease in temperature of 22 ??C. Times to equilibrium were at least 40 h. The magnitude of observed K(d) and k2 values and the effect of temperature on K(d) (e.g., low enthalpy of sorption) are consistent with sorbate partitioning between the aqueous phase and small amounts of organic matter (f(oc) = 0.02%) on the sediments. The temperature dependence of K(d) and k2 may be small as compared to the effects of heterogeneities in field-scale aquifer systems. Thus, thermal gradients may not be of major importance in most saturated subsurface regimes when predicting solute transport. However, aquifer remediation pump-and- treat times could be decreased because increased temperature decreases both retardation and tailing.

  12. Biosurfactants from Acinetobacter calcoaceticus BU03 enhance the solubility and biodegradation of phenanthrene.

    PubMed

    Zhao, Zhenyong; Wong, Jonathan W C

    2009-03-01

    A thermophilic bacterial strain, Acinetobacter calcoaceticus BU03, with a biosurfactant-producing capability, was isolated from petroleum-contaminated soil with an improved procedure which employed the solubilization of polycyclic aromatic hydrocarbons (PAHs), i.e. naphthalene in agar plate, as a selection criterion. Crude biosurfactant was recovered from the culture of BU03 by extraction with n-hexane, and its properties were investigated. Biosurfactants from A. calcoaceticus BU03 constitute a thermo-stable mixture, composed of different agents with surface activities. At their critical micelle concentration (CMC) of 152.4 mg L(-1), the crude biosurfactants produced from A. calcoaceticus BU03 decreased the air-water surface tension to 38.4 mN m(-1). In thermophilic conditions, the emulsifying activity is 2.8 times that of Tween 80. The effects of the biosurfactants produced by A. calcoaceticus on the solubility and biodegradation of PAHs were investigated in batch systems. Biosurfactants produced by A. calcoaceticus BU03 at 25 times their CMC significantly increased the apparent aqueous solubility of phenanthrene (PHE), pyrene (PYR) and benzo(a)pyrene (B[a]P) to 54.3, 6.33 and 2.08 mg L(-1), respectively. In aqueous system, the biosurfactants at concentrations of 0.5 CMC and 1 CMC slightly enhanced the biodegradation of PHE by a consortium of PAH-degrading microrganisms. Results indicate that biosurfactants from A. calcoaceticus BU03 have potential to enhance the removal of PAHs from contaminated sites.

  13. Effect of activated carbon on microbial bioavailability of phenanthrene in soils

    SciTech Connect

    Yang, Y.; Hunter, W.; Tao, S.; Crowley, D.; Gan, J.

    2009-11-15

    Bioavailability is a governing factor that controls the rate of biological degradation of hydrophobic organic contaminants in soil. Among the solid phases that can adsorb hydrophobic organic contaminants in soil, black carbon (BC) exerts a particularly significant effect on phase distribution. However, knowledge on the effect of BC on the microbial availability of polycyclic aromatic hydrocarbons in soil is still limited. In the present study, the effect of a coal-derived activated carbon on the bioavailability of phenanthrene (PHE) during its degradation by Mycobacterium vanbaalenii PYR-1 was measured in three soils. The freely dissolved concentration of PHE was concurrently determined in soil solutions using disposable polydimethylsiloxane fibers. The results showed that PHE mineralization was significantly inhibited after addition of activated carbon in all test soils. After 216 h, only 5.20, 5.83, and 6.85% of PHE was degraded in the 0.5% BC-amended soils initially containing organic carbon at 0.23, 2.1, and 7.1%, respectively. Significant correlation was found between PHE degradability and freely dissolved concentration, suggesting that BC affected PHE bioavailability by decreasing chemical activity. The effect of activated carbon in the amended soils was attributed to its enhancement of soil surface areas and pore volumes. Results from the present study clearly highlighted the importance of BC for influencing the microbial availability of polycyclic aromatic hydrocarbons in soils.

  14. Simulation of carrier-facilitated transport of phenanthrene in a layered soil profile.

    PubMed

    Prechtel, Alexander; Knabner, Peter; Schneid, Eckhard; Totsche, Kai Uwe

    2002-06-01

    The appropriate prediction of the fate of the contaminant is an essential step when evaluating the risk of severe groundwater pollutions-in particular in the context of natural attenuation. We numerically study the reactive transport of phenanthrene at the field scale in a multilayer soil profile based on experimental data. The effect of carrier facilitation by dissolved organic carbon is emphasized and incorporated in the model. Previously published simulations are restricted to the saturated zone and/or to homogeneous soil columns at the laboratory scale. A numerical flow and transport model is extended and applied to understand and quantify the relevant processes in the case of a strongly sorbing hydrophobic organic compound that is subject to carrier facilitation in the unsaturated zone. The contaminant migration is investigated on long- and short-term time scales and compared to predictions without carrier facilitation. The simulations demonstrate the importance of carrier facilitation and suggest strongly to take this aspect into account. By carrier facilitation breakthrough times at the groundwater level decreased from 500 to approximately 8 years and concentration peaks increased by two orders of magnitude in the long-term simulation assuming a temporary spill in an initially unpolluted soil with a non-sorbing carrier.

  15. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation

    PubMed Central

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  16. Soil mineral composition matters: response of microbial communities to phenanthrene and plant litter addition in long-term matured artificial soils.

    PubMed

    Babin, Doreen; Vogel, Cordula; Zühlke, Sebastian; Schloter, Michael; Pronk, Geertje Johanna; Heister, Katja; Spiteller, Michael; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2014-01-01

    The fate of polycyclic aromatic hydrocarbons (PAHs) in soil is determined by a suite of biotic and abiotic factors, and disentangling their role in the complex soil interaction network remains challenging. Here, we investigate the influence of soil composition on the microbial community structure and its response to the spiked model PAH compound phenanthrene and plant litter. We used long-term matured artificial soils differing in type of clay mineral (illite, montmorillonite) and presence of charcoal or ferrihydrite. The soils received an identical soil microbial fraction and were incubated for more than two years with two sterile manure additions. The matured artificial soils and a natural soil were subjected to the following spiking treatments: (I) phenanthrene, (II) litter, (III) litter + phenanthrene, (IV) unspiked control. Total community DNA was extracted from soil sampled on the day of spiking, 7, 21, and 63 days after spiking. Bacterial 16S rRNA gene and fungal internal transcribed spacer amplicons were quantified by qPCR and subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed that the bacterial community composition, which was strongly shaped by clay minerals after more than two years of incubation, changed in response to spiked phenanthrene and added litter. DGGE and qPCR showed that soil composition significantly influenced the microbial response to spiking. While fungal communities responded only in presence of litter to phenanthrene spiking, the response of the bacterial communities to phenanthrene was less pronounced when litter was present. Interestingly, microbial communities in all artificial soils were more strongly affected by spiking than in the natural soil, which might indicate the importance of higher microbial diversity to compensate perturbations. This study showed the influence of soil composition on the microbiota and their response to phenanthrene and litter, which may increase our understanding of

  17. Soil Mineral Composition Matters: Response of Microbial Communities to Phenanthrene and Plant Litter Addition in Long-Term Matured Artificial Soils

    PubMed Central

    Babin, Doreen; Vogel, Cordula; Zühlke, Sebastian; Schloter, Michael; Pronk, Geertje Johanna; Heister, Katja; Spiteller, Michael; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2014-01-01

    The fate of polycyclic aromatic hydrocarbons (PAHs) in soil is determined by a suite of biotic and abiotic factors, and disentangling their role in the complex soil interaction network remains challenging. Here, we investigate the influence of soil composition on the microbial community structure and its response to the spiked model PAH compound phenanthrene and plant litter. We used long-term matured artificial soils differing in type of clay mineral (illite, montmorillonite) and presence of charcoal or ferrihydrite. The soils received an identical soil microbial fraction and were incubated for more than two years with two sterile manure additions. The matured artificial soils and a natural soil were subjected to the following spiking treatments: (I) phenanthrene, (II) litter, (III) litter + phenanthrene, (IV) unspiked control. Total community DNA was extracted from soil sampled on the day of spiking, 7, 21, and 63 days after spiking. Bacterial 16S rRNA gene and fungal internal transcribed spacer amplicons were quantified by qPCR and subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed that the bacterial community composition, which was strongly shaped by clay minerals after more than two years of incubation, changed in response to spiked phenanthrene and added litter. DGGE and qPCR showed that soil composition significantly influenced the microbial response to spiking. While fungal communities responded only in presence of litter to phenanthrene spiking, the response of the bacterial communities to phenanthrene was less pronounced when litter was present. Interestingly, microbial communities in all artificial soils were more strongly affected by spiking than in the natural soil, which might indicate the importance of higher microbial diversity to compensate perturbations. This study showed the influence of soil composition on the microbiota and their response to phenanthrene and litter, which may increase our understanding of

  18. PHOTOACTIVATION AND TOXICITY OF MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN MARINE SEDIMENT

    EPA Science Inventory

    The direct toxicity and photoinduced toxicity of sediment-associated acenaphthene, phenanthrene, fluoranthene, and pyrene were determined for the marine amphipod Rhepoxynius abronius. The four polycyclic aromatic hydrocarbons (PAHs) were spiked into sediment in a concentration se...

  19. Metal oxides, clay minerals and charcoal determine the composition of microbial communities in matured artificial soils and their response to phenanthrene.

    PubMed

    Babin, Doreen; Ding, Guo-Chun; Pronk, Geertje Johanna; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2013-10-01

    Microbial communities in soil reside in a highly heterogeneous habitat where diverse mineral surfaces, complex organic matter and microorganisms interact with each other. This study aimed to elucidate the long-term effect of the soil mineral composition and charcoal on the microbial community composition established in matured artificial soils and their response to phenanthrene. One year after adding sterile manure to different artificial soils and inoculating microorganisms from a Cambisol, the matured soils were spiked with phenanthrene or not and incubated for another 70 days. 16S rRNA gene and internal transcribed spacer fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis. Metal oxides and clay minerals and to a lesser extent charcoal influenced the microbial community composition. Changes in the bacterial community composition in response to phenanthrene differed depending on the mineral composition and presence of charcoal, while no shifts in the fungal community composition were observed. The abundance of ring-hydroxylating dioxygenase genes was increased in phenanthrene-spiked soils except for charcoal-containing soils. Here we show that the formation of biogeochemical interfaces in soil is an ongoing process and that different properties present in artificial soils influenced the bacterial response to the phenanthrene spike.

  20. Effect of low-molecular-weight organic acids on photo-degradation of phenanthrene catalyzed by Fe(III)-smectite under visible light.

    PubMed

    Jia, Hanzhong; Chen, Hongxia; Nulaji, Gulimire; Li, Xiyou; Wang, Chuanyi

    2015-11-01

    The photolysis of polycyclic aromatic hydrocarbons (PAHs) is potentially an important process for its transformation and fate on contaminated soil surfaces. In this study, phenanthrene is employed as a model to explore PAH photodegradation with the assistance of Fe(III)-smectite under visible-light while focusing on roles played by five low-molecular-weight organic acids (LMWOAs), i.e., malic acid, oxalic acid, citric acid, ethylenediaminetetraacetic acid (EDTA), and nitrilotriacetic acid. Our results show that oxalic acid is most effective in promoting the photodegradation of phenanthrene, while only a slight increase in the rate of phenanthrene photodegradation is observed in the presence of malic acid. Electron paramagnetic resonance experiments confirm the formation of CO2(-) radicals in the presence of malic and oxalic acid, which provides strong evidence for generating OH and subsequent photoreaction pathways. The presence of EDTA or nitrilotriacetic acid significantly inhibits both Fe(II) formation and phenanthrene photodegradation because these organic anions tend to chelate with Fe(III), leading to decreases in the electron-accepting potential of Fe(III)-smectite and a weakened interaction between phenanthrene and Fe(III)-smectite. These observations provide valuable insights into the transformation and fate of PAHs in the natural soil environment and demonstrate the potential for using some LMWOAs as additives for the remediation of contaminated soil. PMID:26091867

  1. Effect of low-molecular-weight organic acids on photo-degradation of phenanthrene catalyzed by Fe(III)-smectite under visible light.

    PubMed

    Jia, Hanzhong; Chen, Hongxia; Nulaji, Gulimire; Li, Xiyou; Wang, Chuanyi

    2015-11-01

    The photolysis of polycyclic aromatic hydrocarbons (PAHs) is potentially an important process for its transformation and fate on contaminated soil surfaces. In this study, phenanthrene is employed as a model to explore PAH photodegradation with the assistance of Fe(III)-smectite under visible-light while focusing on roles played by five low-molecular-weight organic acids (LMWOAs), i.e., malic acid, oxalic acid, citric acid, ethylenediaminetetraacetic acid (EDTA), and nitrilotriacetic acid. Our results show that oxalic acid is most effective in promoting the photodegradation of phenanthrene, while only a slight increase in the rate of phenanthrene photodegradation is observed in the presence of malic acid. Electron paramagnetic resonance experiments confirm the formation of CO2(-) radicals in the presence of malic and oxalic acid, which provides strong evidence for generating OH and subsequent photoreaction pathways. The presence of EDTA or nitrilotriacetic acid significantly inhibits both Fe(II) formation and phenanthrene photodegradation because these organic anions tend to chelate with Fe(III), leading to decreases in the electron-accepting potential of Fe(III)-smectite and a weakened interaction between phenanthrene and Fe(III)-smectite. These observations provide valuable insights into the transformation and fate of PAHs in the natural soil environment and demonstrate the potential for using some LMWOAs as additives for the remediation of contaminated soil.

  2. Remediation of polluted soil by a two-stage treatment system: desorption of phenanthrene in soil and electrochemical treatment to recover the extraction agent.

    PubMed

    Gómez, J; Alcántara, M T; Pazos, M; Sanromán, M A

    2010-01-15

    In this study, the feasibility of a two-stage treatment process for the remediation of soil contaminated with phenanthrene as a model polycyclic aromatic hydrocarbon (PAH) has been assessed at laboratory scale. The initial stage of the process involved contacting contaminated soil with a solution of Tween 80 to enhance the desorption of phenanthrene from soil. In order to simulate a flushing process this initial stage was carried out in a washing packed-bed soil column. At the optimised conditions the total phenanthrene removal attained a value of almost 65% after 3 days. The second stage of the suggested treatment involved regeneration of the washing solution via phenanthrene degradation. The use of an electrochemical treatment was proposed for surfactant recovery and degradation of contaminants present in the solution collected. This oxidation was accomplished via an electrochemical cell by using graphite as electrode material. The phenanthrene was almost totally degraded in 3 days, reaching a degradation of about 96%. In addition, a test in which this regenerated solution was employed in the washing process was carried out in shake flask and washing column. The results demonstrate that selective degradation of pollutants by electrochemical treatment is potentially effective in reusing surfactant in another polluted soil treatment. PMID:19758751

  3. Synergistic effect of thermophilic temperature and biosurfactant produced by Acinetobacter calcoaceticus BU03 on the biodegradation of phenanthrene in bioslurry system.

    PubMed

    Zhao, Zhenyong; Selvam, Ammaiyappan; Wong, Jonathan Woon-Chung

    2011-06-15

    This study aimed at investigating the synergistic effect of temperature and biosurfactant on the biodegradation of phenanthrene in bioslurry. Bench-scale bioslurry experiments were conducted at 25 and 55°C. The desorption rate coefficients of phenanthrene (K(des)) obtained using the pseudo-first order model were 0.0026 and 0.0035 kg mg(-1)h(-1) at 25 and 55°C, respectively. Addition of 1500 mg L(-1) biosurfactant, produced by Acinetobacter calcoaceticus BU03, marginally increased the K(des) at 25°C since most of biosurfactant was sorbed onto soil; however, significantly increased the K(des) to 0.0087 kg mg(-1)h(-1) at 55°C as the thermophilic temperature reduced the adsorption of the biosurfactant onto soil and subsequently enhanced the desorption of phenanthrene. The biodegradation of phenanthrene well fitted pseudo-first order kinetics based on the assumption that biodegradation was limited by the desorption. About 78.7% of phenanthrene was degraded in 30 days at 25°C; and addition of biosurfactant did not affect the biodegradation. However, addition of the biosurfactant or inoculation of A. calcoaceticus BU03 at 55°C significantly enhanced the biodegradation by increasing the K(des). Results indicate that synergistic application of thermophilic temperature and biosurfactant or inoculation of biosurfactant producing microorganisms is an effective and innovative method to enhance the efficiency of PAH degradation in bioslurry system.

  4. Optical Studies of Poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) and its Nanocomposites

    NASA Astrophysics Data System (ADS)

    Layek, S.; Ghosh, M.; Reddy, K. Siddarth; Senapati, S.; Maiti, P.; Sinha, S.

    2015-11-01

    Steady state and time-resolved spectroscopic measurements are carried out to understand the fluorescent optical properties of the conjugated polymer poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) (PFV) in liquid phase and solid phase. Quite significant color tuning is observed in the fluorescence emission of PFV in the blue side of the spectra in the solid phase, especially in powder form, when the polymer is doped with 30B nanoclay (organically modified Montmorillonite) and graphene nanoparticles. Interestingly, the average fluorescence lifetime of PFVgraphene nanocomposite in thin film is found to be much higher (8.1 ns) compared to that for PFV only in thin film (3 ns). These novel nanocomposites may have potential applications in polymer optoelectronics industry.

  5. Mycoremediation of manganese and phenanthrene by Pleurotus eryngii mycelium enhanced by Tween 80 and saponin.

    PubMed

    Wu, Minghui; Xu, Yongan; Ding, Wenbo; Li, Yuanyuan; Xu, Heng

    2016-08-01

    Bioremediation of areas co-contaminated with metals and polycyclic aromatic hydrocarbons (PAHs) by mushrooms has attracted considerable attention in recent years. In this study, Pleurotus eryngii was introduced for the removal of Mn and phenanthrene (Phe) from potato liquid medium (PDL) simultaneously. Effects of Tween 80 and saponin on P. eryngii growth together with Mn uptake as well as Phe removal were investigated. Although pollutants had a negative effect on mycelial morphology and growth, P. eryngii could still tolerate and remove Mn and Phe. Tween 80 increased removal of Mn and Phe through increase of P. eryngii growth, Phe solubility, pollutants bioavailability, and specific surface area of mycelium pellets, moreover, the activities of manganese peroxidase (MnP) and laccase, which played an important role on PAHs biodegradation. The maximal removal of Mn and Phe was achieved (92.17 and 93.85 % after 15 days incubation, respectively) with 0.6 g L(-1) Tween 80. Treatments with saponin markedly inhibited P. eryngii growth (50.17-66.32 % lower relative to control) due to its fungistatic activity. Nevertheless, saponin could slightly enhance Phe removal through increasing solubility of Phe, and Phe removal rate varied from 80.53 to 87.06 % in saponin treatments. Joint stress of Mn and Phe induced a strong antioxidative response, and superoxide dismutase (SOD) activity decreased in surfactants-treated mycelium compared with control. Generally, Tween 80 was more suitable for strengthening mycoremediation by P. eryngii than saponin, and could be a promising alternative for the remediation of heavy metals and PAHs co-contaminated sites by mushrooms. PMID:27102128

  6. Influence of single-walled carbon nanotubes on microbial availability of phenanthrene in sediment.

    PubMed

    Cui, X Y; Jia, F; Chen, Y X; Gan, J

    2011-08-01

    Increasing production and use of single-walled carbon nanotubes (SWCNT) will inevitably lead to release of these nanoparticles to aquatic ecosystems. Similar to black carbon (BC) particles, SWCNT have a high affinity for hydrophobic organic contaminants (HOCs) and therefore the presence of SWCNT in sediment may lead to altered bioavailability of HOCs. We compared SWCNT with biochar and charcoal on their effect on the microbial degradability of 0.05 mg kg(-1) (14)C-phenanthrene (PHE) by Mycobacterium vanbaalenii PYR-1 in two sediments with different organic carbon (OC) contents. When the amendment rate of SWCNT or BC was 1 mg g(-1), PHE mineralization was inhibited much more significantly by SWCNT than by either biochar or charcoal. After 360 h of incubation, the mineralized fraction of PHE in the presence of SWCNT was 59.5% of the non-amended control in the sediment with low OC content, and only 42.4% in the other sediment with a higher OC content. Analysis of the freely dissolved concentration (C (free)) using disposable polydimethylsiloxane (PDMS) fibers showed that SWCNT decreased C (free) by 85-95%, apparently due to preferential sorption of PHE to SWCNT particles that had a much larger specific surface area and pore volume than biochar or charcoal. However, pre-interaction of SWCNT with dissolved organic matter (peptone, tannic acid, and humic acid) led to attachment of polar functional groups and reduced surface area on SWCNT, resulting in decreased PHE sorption and an alleviated effect on PHE biodegradation in the order of peptone > tannic acid > humic acid.

  7. Changes of biomarkers with oral exposure to benzo(a)pyrene, phenanthrene and pyrene in rats

    PubMed Central

    Kang, Hwan Goo; Cho, Myung Haing; Cho, Joon Hyoung

    2007-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants present in air and food. Among PAHs, benzo(a)pyrene(BaP), phenanthrene (PH) and pyrene (PY) are considered to be important for their toxicity or abundance. To investigate the changes of biomarkers after PAH exposure, rats were treated with BaP (150 µg/kg) alone or with PH (4,300 µg/kg) and PY (2,700 µg/kg) (BPP group) by oral gavage once per day for 30 days. 7-ethoxyresorufin-O-deethylase activity in liver microsomal fraction was increased in only BaP groups. The highest concentration (34.5 ng/g) of BaP, was found in muscle of rats treated with BaP alone at 20 days of treatment; it was 23.6 ng/g in BPP treated rats at 30 days of treatment. The highest PH concentration was 47.1 ng/g in muscle and 118.8 ng/g in fat, and for PY it was 29.7 ng/g in muscle and 219.9 ng/g in fat, in BPP groups. In urine, 114-161 ng/ml 3-OH-PH was found, while PH was 41-69 ng/ml during treatment. 201-263 ng/ml 1-OH-PY was found, while PH was 9-17 ng/ml in urine. The level of PY, PH and their metabolites in urine was rapidly decreased after withdrawal of treatment. This study suggest that 1-OH-PY in urine is a sensitive biomarker for PAHs; it was the most highly detected marker among the three PAHs and their metabolites evaluated during the exposure period and for 14 days after withdrawal. PMID:17993750

  8. The characteristics of phenanthrene biosorption by chemically modified biomass of Phanerochaete chrysosporium.

    PubMed

    Gu, Haiping; Luo, Xiaoyan; Wang, Haizhen; Wu, Laosheng; Wu, Jianjun; Xu, Jianming

    2015-08-01

    The natural (S0) and chemically modified Phanerochaete chrysosporium including the methylation of amino groups (S1), acetylation of hydroxyl groups (S2), lipid removal (S3), esterification of carboxyl groups (S4), and base hydrolysis (S5) were characterized, and their sorption for phenanthrene (PHE) was investigated. The sorption isotherm of PHE on natural biomasses was apparently linear, while it was nonlinear for the modified ones. The partition coefficient (K d ) describing the sorption affinity of PHE by biomasses followed the order of S0 (9.24 L g(-1)) > S5 (8.94 L g(-1)) > S1 (7.13 L g(-1)) > S2 (6.97 L g(-1)) > S3 (6.38 L g(-1)) > S4 (3.51 L g(-1)) and decreased as temperature increased. The PHE adsorption fitted well to the pseudo-second-order kinetic model, and the sorption capacity was in the order of S5 (2041.5 μg g(-1)) > S0 (1768.8 μg g(-1)) > S2 (1570.9 μg g(-1)) > S1 (1552.9 μg g(-1)) > S3 (1346.4 μg g(-1)) > S4 (991.0 μg g(-1)). Moreover, the π-π and electron donor-acceptor interactions may govern PHE sorption which processed spontaneously and exothermally. The natural and modified biomasses, especially the base hydrolysis treated ones, were economical and effective biosorbents for PHE removal. PMID:25860550

  9. Enhancement of toxic effects of phenanthrene to Daphnia magna due to the presence of suspended sediment.

    PubMed

    Zhang, Xiaotian; Xia, Xinghui; Dong, Jianwei; Bao, Yimeng; Li, Husheng

    2014-06-01

    In the present work, the influences of suspended sediment (SPS) on the toxic effects of phenanthrene (PHE), one kind of polycyclic aromatic hydrocarbons, to Daphnia magna was studied using a dialysis bag simulation system, which equalized the freely dissolved concentration of PHE between outside the dialysis bag in the presence of SPS and inside the dialysis bag in the absence of SPS. The immobilization and total superoxide dismutase (T-SOD) activity of Daphnia magna caused by PHE (0-0.8 mg L(-1)) were investigated under the influence of different SPS concentrations (0, 1, 3, 5 g L(-1)) during a 96 h-exposure. The results showed that, compared to the absence of SPS, the presence of SPS (1-5 g L(-1)) increased the immobilization of Daphnia magna by 1.6-2.7 times when the freely dissolved concentration of PHE was identical in both systems. The inhibition of T-SOD activity of Daphnia magna by PHE was significantly greater in the presence of SPS than in the absence of SPS (p<0.01). This infers that the PHE sorbed on SPS might be bioavailable and enhanced the toxic effect of PHE to Daphnia magna. The bioavailable fraction of PHE sorbed on SPS ranged from 10.1% to 22.7%, and the contribution of PHE sorbed on SPS to the immobilization caused by total PHE in the exposure system increased with SPS concentration, with the contribution ratio increasing from 36.7% to 57.7% when SPS concentration increased from 1 to 5 g L(-1). This study suggests that only considering the concentrations of hydrophobic organic compounds in the water phase may underestimate their toxicity; and the hydrophobic organic compounds sorbed on SPS should not be ignored in assessment of water quality and the establishment of water quality standard in the future.

  10. Biochar characteristics produced from food-processing products and their sorptive capacity for mercury and phenanthrene

    NASA Astrophysics Data System (ADS)

    Fotopoulou, Kalliopi N.; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.

    2015-04-01

    Various organic-rich wastes including wood chips, animal manure, and crop residues have been used for biochar production. Biochar is used as an additive to soils to sequester carbon and improve soil fertility but its use as a sorbent for environmental remediation processes is gaining increased attention. Surface properties such as point of zero charge, surface area and pore volume, surface topography, surface functional groups and acid-base behavior are important factors, which affect sorption efficiency. Understanding the surface alteration of biochars increases our understanding of the pollutant-sorbent interaction. The scope of the present work was to evaluate the effect of key characteristics of biochars on their sorptive properties. Raw materials for biochar production were evaluated including byproducts from brewering, coffee, wine, and olive oil industry. The charring process was performed at different temperatures under limited-oxygen conditions using specialized containers. The surface area, the pore volume, and the average pore size of the biochars were determined. Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. Raw food-processing waste demonstrates low surface area that increases by 1 order of magnitude by thermal treatment up to 750oC. At temperatures from 750 up to 900oC, pyrolysis results to biochars with surface areas 210-700 m2/g. For the same temperature range, a high percentage (46 to73%) of the pore volume of the biochars is due to micropores. Positive results were obtained when high surface area biochars were tested for their ability to remove organic (i.e. phenanthrene) and inorganic (i.e. mercury) compounds from aqueous solutions. All these properties point to new materials that can effectively be used for environmental remediation.

  11. Extracellular polymeric substances facilitate the biosorption of phenanthrene on cyanobacteria Microcystis aeruginosa.

    PubMed

    Bai, Leilei; Xu, Huacheng; Wang, Changhui; Deng, Jiancai; Jiang, Helong

    2016-11-01

    Phytoplankton-derived extracellular polymeric substances (EPS) are of vital importance for the biogeochemical cycles of hydrophobic organic pollutants in lake ecosystems. In this study, roles of loosely-bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) in biosorption of phenanthrene (PHE) on a typical cyanobacteria Microcystis aeruginosa were investigated. The results showed that the biosorption of PHE on M. aeruginosa cell varied lasted 24 h, while the binding of PHE to LB-EPS and TB-EPS reached equilibrium within less than 2 h. The equilibrium biosorption capacities of M. aeruginosa cell, LB-EPS and TB-EPS were 6.78, 12.31, and 9.47 μg mg(-1), respectively, indicating that the binding of PHE to EPS was a considerable process involved in biosorption. Fluorescence quenching titration revealed that increasing temperature induced more binding sites in EPS for PHE and the binding process was driven by electrostatic force and hydrophobic interactions. Interestingly, dynamic and static quenching processes occurred simultaneously for the binding of PHE to protein-like substances in EPS, whereas the binding of PHE to humic-like substances belonged to static quenching. The relatively higher contents of proteins in LB-EPS produced a stronger binding capacity of PHE. Overall, the interactions between hydrophobic organic pollutants and cyanobacterial EPS are favorable to the bioaccumulation of hydrophobic organic pollutants in cyanobacteria and facilitate the regulatory function of cyanobacterial biomass as a biological pump. PMID:27497347

  12. Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination.

    PubMed

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Sheng, Yuehui; Kang, Fuxing; Waigi, Michael Gatheru

    2015-12-01

    Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil. PMID:26263885

  13. [Sorption Characteristics of Phenanthrene and 1, 1-Dichloroethene onto Reed Straw Biochar in Aquatic Solutions].

    PubMed

    Wu, Qing-wen; Meng, Liang; Zhang, Zhi-hao; Luo, Qi-shi; Yang, Jie

    2016-02-15

    The purpose of this study was to investigate the sorption characteristics of phenanthrene (PHE) and 1, 1-dichloroethene (1, 1-DCE) onto reed straw biochar at 500 degrees C in aquatic solutions. The sorption mechanisms and effects of solution pH and biochar mass on sorption intensity were discussed. The results showed that the time required to reach sorption equilibrium was 60 min and 480 min for PHE and 1, 1-DCE, respectively, with maximum removal rates of 81, 87% and 90.18%. The sorption kinetics of both PHE and 1, 1-DCE fitted the pseudo-second-order model well, but the pseudo-second-order reaction rate of PHE was higher than that of 1, 1-DCE. Furthermore, the sorption processes were controlled by both membrane diffusion and intra-particle diffusion, and the latter was found to be the rate-controlling step. Sorption isotherms of the two organic pollutants fitted well with the Freundlich equation, and the sorption affinity of 1, 1-DCE onto biochar was greater than that of PHE. The total sorption mechanism of biochar was the combination of partition and adsorption, and dominated by adsorption. The adsorption capacity of 1, 1-DCE was greater than that of PHE, but its partition capacity was much smaller, indicating that pollutants' molecular volume and relative polarity would mainly affect the total sorption. Analysis of Fourier transform infrared spectroscopy (FTIR) demonstrated that oxygen- and hydrogen-containing functional groups and pi--pi interaction were important for PHE and 1, 1-DCE sorption onto biochar. The solution pH value had no significant effect on the sorption intensity of PHE and 1, 1-DCE, however, with biochar mass increasing from 5 mg to 50 mg, the equilibrium sorption amount of PHE and 1, 1-DCE decreased by 6.78 times and 2.18 times, and the removal rate increased by 20.21% and 15.78%, respectively. PMID:27363160

  14. Keto defect sites in fluorene-based organic field-effect transistors: The origin of rapid degradation on the performance of the device

    SciTech Connect

    Noh, Yong-Young; Kim, Dong-Yu; Yoshida, Yuji; Yase, Kiyoshi; Jung, Byung-Jun; Lim, Eunhee; Shim, Hong-Ku; Azumi, Reiko

    2005-05-15

    The effect of keto defects in fluorene units on the performance of organic field-effect transistors (OFETs) was examined based on fluorene end-capped fused bithiophenes (BFTT) and biphenyl end-capped fused bithiophene oligomers (BPTT). The formation of keto defects after various periods of UV illumination in air on BFTT films was confirmed by the increase of the long-wavelength emission at 2.1-2.3 eV in the photoluminescent (PL) spectrum and the generation of a Fourier transfer infrared (FTIR) peak at 1721 cm{sup -1}, corresponding to the carbonyl stretching mode of the fluorenone moiety. For both BPTT films irradiated in air and BFTT in nitrogen, i.e., a keto-free system, no increase in long-wavelength emission in the PL spectrum, was found and the peak corresponding to the carbonyl stretching mode of the fluorenone moiety was absent in the FTIR spectrum. The threshold voltage, i.e., switch-on voltage, of the OFETs was increased and the field-effect mobility and on-state drain current were rapidly decreased after the formation of ketonic defects, since these defects induce the formation of numerous trap sites in the band gap of the semiconducting conjugated oligomer. The density of trap sites (N{sub t}) generated after the formation of keto defects was determined using space-charge-limited current spectroscopy. A N{sub t} of around 2.7x10{sup 15} cm{sup -3} was found for the BFTT film due to the formation of keto defects after 6 h of UV irradiation.

  15. DNA single strand breakage, DNA adducts, and sister chromatid exchange in lymphocytes and phenanthrene and pyrene metabolites in urine of coke oven workers.

    PubMed Central

    Popp, W; Vahrenholz, C; Schell, C; Grimmer, G; Dettbarn, G; Kraus, R; Brauksiepe, A; Schmeling, B; Gutzeit, T; von Bülow, J; Norpoth, K

    1997-01-01

    OBJECTIVES: To investigate the specificity of biological monitoring variables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, 32P postlabelling assay, measurement of sister chromatid exchange) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (alkaline filter elution assay), sister chromatid exchange, and DNA adducts (32P postlabelling assay) in lymphocytes. Phenanthrene and pyrene metabolites were measured in 24 hour urine samples. 19 different PAHs (including benzo(a)pyrene, pyrene, and phenanthrene) were measured at the workplace by personal air monitoring. The GSTT1 activity in erythrocytes and lymphocyte subpopulations in blood was also measured. RESULTS: Concentrations of phenanthrene, pyrene, and benzo(a)pyrene in air correlated well with the concentration of total PAHs in air; they could be used for comparisons of different workplaces if the emission compositions were known. The measurement of phenanthrene metabolites in urine proved to be a better biological monitoring variable than the measurement of 1-hydroxypyrene. Significantly more DNA strand breaks in lymphocytes of coke oven workers were found (alkaline filter elution assay); the DNA adduct rate was not significantly increased in workers, but correlated with exposure to PAHs in a semiquantitative manner. The number of sister chromatid exchanges was lower in coke oven workers but this was not significant; thus counting sister chromatid exchanges was not a good variable for biomonitoring of coke oven workers. Also, indications for immunotoxic influences (changes in lymphocyte subpopulations) were found. CONCLUSIONS: The measurement of phenanthrene metabolites in urine seems to be a better biological monitoring variable for exposure to PAHs than

  16. Novel maturity parameters for mature to over-mature source rocks and oils based on the distribution of phenanthrene series compounds.

    PubMed

    Wang, Zixiang; Wang, Yongli; Wu, Baoxiang; Wang, Gen; Sun, Zepeng; Xu, Liang; Zhu, Shenzhen; Sun, Lina; Wei, Zhifu

    2016-03-01

    Pyrolysis experiments of a low-mature bitumen sample originated from Cambrian was conducted in gold capsules. Abundance and distribution of phenanthrene series compounds in pyrolysis products were measured by GC-MS to investigate their changes with thermal maturity. Several maturity parameters based on the distribution of phenanthrene series compounds have been discussed. The results indicate that the distribution changes of phenanthrene series compounds are complex, and cannot be explained by individual reaction process during thermal evolution. The dealkylation cannot explain the increase of phenanthrene within the EasyRo range of 0.9% ∼ 2.1%. Adding of phenanthrene into maturity parameters based on the methylphenanthrene isomerization is unreasonable, even though MPI 1 and MPI 2 could be used to some extent. Two additional novel and an optimized maturation parameters based on the distribution of phenanthrene series compounds are proposed and their relationships to EasyRo% (x) are established: log(MPs/P) = 0.19x + 0.08 (0.9% < EasyRo% < 2.1%); log(MPs/P) = 0.64x - 0.86 (2.1% < EasyRo% < 3.4%); log(DMPs/TMPs) = 0.71x - 0.55 (0.9% < EasyRo% < 3.4%); log(MTR) = 0.84x - 0.75 (0.9% < EasyRo% < 3.4%). These significant positive correlations are strong argument for using log(MPs/P), log(DMPs/TMPs) and log(MTR) as maturity parameters, especially for mature to over-mature source rocks. PMID:27441263

  17. Bioavailability of phenanthrene in the presence of birnessite-mediated catechol polymers.

    PubMed

    Russo, Fabio; Rao, Maria A; Gianfreda, Liliana

    2005-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants and contribute to the pollution of aquatic and terrestrial environments. In soil, their fate may be affected by interactions with the soil biological community and soil colloids. This study was conducted to investigate the fate of phenanthrene (Phe), selected as a representative PAH, in simplified model systems, which simulate processes naturally occurring in soil. Phe was interacted with catechol (Cat), an orthodiphenol, and common intermediate in the microbial degradation of PAHs, and birnessite (Bir), an abiotic strong oxidative catalyst abundant in soil. Two experimental conditions were investigated: Cat (5 mM)+Bir (1 mg ml(-1))+Phe (0.05 mg ml(-1)) mixed at the same time and incubated for 24 h at 25 degrees C (Cat-Bir-Phe) and Cat+Bir incubated for 24 h at 25 degrees C before Phe addition and then incubated for a further 24 h (Cat-Bir+Phe). After incubation, the systems were analysed for residual Cat and Phe, supplied with a selected Phe-degrading mixed bacterial culture, and then the microbial degradation of Phe and the growth of cells were monitored. Complex phenomena simultaneously occurred. Cat was completely removed after a 24-h incubation with Bir, and no interference by Phe in the Bir-mediated transformation of Cat was observed. Elemental analysis and UV-Vis and Fourier transfer infrared spectra showed that Cat transformation by Bir produced soluble and insoluble polymeric aggregates involving Phe. The hydrocarbon also interacted with the surfaces of Bir either previously coated (Cat-Bir+Phe sample) or not by Cat polymers. When a Phe-degrading bacterial culture was added to the systems after Bir-mediated Cat polymerisation, a different behaviour was observed in terms of Phe consumption and bacterial growth, thus suggesting differentiated availability of Phe to the microbial cells. The hydrocarbon was completely transformed in the presence of Bir and/or Bir covered by Cat

  18. Accumulation of phenanthrene by roots of intact wheat (Triticum acstivnm L.) seedlings: passive or active uptake?

    PubMed Central

    2010-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs) are of particular concern due to their hydrophobic, recalcitrant, persistent, potentially carcinogenic, mutagenic and toxic properties, and their ubiquitous occurrence in the environment. Most of the PAHs in the environment are present in surface soil. Plants grown in PAH-contaminated soils or water can become contaminated with PAHs because of their uptake. Therefore, they may threaten human and animal health. However, the mechanism for PAHs uptake by crop roots is little understood. It is important to understand exactly how PAHs are transported into the plant root system and into the human food chain, since it is beneficial in governing crop contamination by PAHs, remedying soils or waters polluted by PAHs with plants, and modeling potential uptake for risk assessment. Results The possibility that plant roots may take up phenanthrene (PHE), a representative of PAHs, via active process was investigated using intact wheat (Triticum acstivnm L.) seedlings in a series of hydroponic experiments. The time course for PHE uptake into wheat roots grown in Hoagland solution containing 5.62 μM PHE for 36 h could be separated into two periods: a fast uptake process during the initial 2 h and a slow uptake component thereafter. Concentration-dependent PHE uptake was characterized by a smooth, saturable curve with an apparent Km of 23.7 μM and a Vmax of 208 nmol g-1 fresh weight h-1, suggesting a carrier-mediated uptake system. Competition between PHE and naphthalene for their uptake by the roots further supported the carrier-mediated uptake system. Low temperature and 2,4-dinitrophenol (DNP) could inhibit PHE uptake equally, indicating that metabolism plays a role in PHE uptake. The inhibitions by low temperature and DNP were strengthened with increasing concentration of PHE in external solution within PHE water solubility (7.3 μM). The contribution of active uptake to total absorption was almost 40% within PHE water

  19. Effect of model dissolved organic matter coating on sorption of phenanthrene by TiO2 nanoparticles.

    PubMed

    Wang, Xilong; Ma, Enxing; Shen, Xiaofang; Guo, Xiaoying; Zhang, Meng; Zhang, Haiyun; Liu, Ye; Cai, Fei; Tao, Shu; Xing, Baoshan

    2014-11-01

    Dissolved organic matter (DOM) may alter the sorption of hydrophobic organic contaminants (HOC) to metal oxide nanoparticles (NPs), but the role of DOM and NP types is poorly understood. Here, phenanthrene sorption was quantified on four types of nano-TiO2 (three rutile, one anatase), and a bulk, raw TiO2 powder. Prior to the sorption experiments, these nanoparticles were coated using four different organic materials: Lignin (LIG), tannic acid (TAN), Congo red (CON), and capsorubin (CAP). Lignin, tannic acid, congo red and capsorubin coating substantially enhanced phenanthrene sorption to various TiO2 particles. After coating with a specific DOM, Kd values by the DOM-coated TiO2 particles on percent organic carbon content and surface area (SA) basis (Koc/SA) generally followed the order: TiO2 NPs with hydrophobic surfaces > bulk TiO2 particles > other TiO2 NPs. Different Koc/SA values of various DOM-TiO2 complexes resulted from distinct conformation of the coated DOM and aggregation.

  20. Derivation of water quality criteria of phenanthrene using interspecies correlation estimation models for aquatic life in China.

    PubMed

    Wu, Jiangyue; Liu, Zhengtao; Yan, Zhenguang; Yi, Xianliang

    2015-06-01

    Species sensitivity distribution (SSD) method has been widely used to derive water quality criteria (WQC). However, the toxicity data of some environmental pollutants are not easily accessible, especially for endangered and threatened species. Thus, it would be very desirable and economical to predict the toxicity of those species not subjected to toxicity test with the aid of a mathematical model. The interspecies correlation estimation (ICE) model (developed by the US Environmental Protection Agency (USEPA)) uses the initial toxicity estimate for one species to produce correlated toxicity values for multiple species, and it can be utilized to develop SSD and HC5 (hazardous concentration, 5th percentile). In this study, we explored the applicability of ICE to predict toxicity of phenanthrene to various species. ICE-based SSDs were generated using three surrogate species (Oncorhynchus mykiss, Lepomis macrochirus, and Daphnia magna) and compared with the metrical-based SSD. The corresponding HC5 of both models were also compared. The results showed there were no significant differences between HC5 derived from measured acute and ICE-based predicted values. The ICE model was verified as a valid approach for generating SSDs with limited toxicity data and deriving WQC for phenanthrene.

  1. Biosorption and biodegradation of phenanthrene and pyrene in sterilized and unsterilized soil slurry systems stimulated by Phanerochaete chrysosporium.

    PubMed

    Chen, Baoliang; Ding, Jie

    2012-08-30

    To assess the "bioaccessible" pool of mycelia-bound polycyclic aromatic hydrocarbons (PAHs) and to quantify its biodegradation kinetics in soil, a soil-slurry system containing mycelial pellets of Phanerochaete chrysosporium as a separable biophase was set up. In sterilized and unsterilized soil-slurry, the distribution and dissipation of phenanthrene and pyrene in soil, fungal body of P. chrysosporium and water were independently quantified over the incubation periods. Biosorption and biodegradation contributions to bio-dissipation of dissolved- and sorbed-PAHs were identified. The biodegradation kinetics of PAHs by allochthonous P. chrysosporium and soil wild microorganisms was higher than those predicted by a coupled desorption-biodegradation model, suggesting both allochthonous and wild microorganisms could access sorbed-PAHs. The obvious hysteresis of PAHs in soil reduced their biodegradation, while the biosorbed-PAHs in P. chrysosporium body as an interim pool exhibited reversibly desorption and were almost exhausted via biodegradation. Both biosorption and direct biodegradation of PAHs in soil slurry were stimulated by allochthonous P. chrysosporium. After 90-day incubation, the respective biodegradation percentages for phenanthrene and pyrene were 63.8% and 51.9% in the unsterilized soil without allochthonous microorganisms, and then increased to 94.9% and 90.6% when amended with live P. chrysosporium. These indicate that allochthonous and wild microorganisms may synergistically attack sorbed-PAHs.

  2. Surfactant-modified fatty acid composition of Citrobacter sp. SA01 and its effect on phenanthrene transmembrane transport.

    PubMed

    Li, Feng; Zhu, Lizhong

    2014-07-01

    The effects of the surfactants, Tween 80 and sodium dodecyl benzene sulfonate (SDBS) on a membrane's fatty acid composition and the transmembrane transport of phenanthrene were investigated. The results indicated that both surfactants could modify the composition of fatty acids of Citrobacter sp. Strain SA01 cells, 50 mg L(-1) of both surfactants changed the composition of the fatty acids the most, increasing the amount of unsaturated fatty acids. The comparison of fatty acid profiles with diphenylhexatriene fluorescence anisotropy, a probe for plasma membrane fluidity, suggested that an increased amount of unsaturated fatty acids corresponded to greater membrane fluidity. In addition, increased unsaturated fatty acids promoted phenanthrene to partition from the extracellular matrix to cell debris, which increased reverse partitioning from the cell debris to the cytochylema. The results of this study were expected in that the addition of a surfactant is a simple and effective method for accelerating the rate-limiting step of transmembrane transport of hydrophobic organic compounds (HOCs) in bioremediation.

  3. Solar-energy production and energy-efficient lighting: photovoltaic devices and white-light-emitting diodes using poly(2,7-fluorene), poly(2,7-carbazole), and poly(2,7-dibenzosilole) derivatives.

    PubMed

    Beaupré, Serge; Boudreault, Pierre-Luc T; Leclerc, Mario

    2010-02-23

    World energy needs grow each year. To address global warming and climate changes the search for renewable energy sources with limited greenhouse gas emissions and the development of energy-efficient lighting devices are underway. This Review reports recent progress made in the synthesis and characterization of conjugated polymers based on bridged phenylenes, namely, poly(2,7-fluorene)s, poly(2,7-carbazole)s, and poly(2,7-dibenzosilole)s, for applications in solar cells and white-light-emitting diodes. The main strategies and remaining challenges in the development of reliable and low-cost renewable sources of energy and energy-saving lighting devices are discussed.

  4. Palladium-Catalyzed Intermolecular Controlled Insertion of Benzyne-Benzyne-Alkene and Benzyne-Alkyne-Alkene-Synthesis of Phenanthrene and Naphthalene Derivatives.

    PubMed

    Yoshikawa; Yamamoto

    2000-01-01

    Aryne reagents, unlike alkynes, undergo insertion by allyl palladium complexes. The verification of the conversion described here is shown using Equation (1) as an example. The reaction proceeds in a few hours in refluxing acetonitrile to give the phenanthrene derivative in up to 71 % yield.

  5. Moderate salinity reduced phenanthrene-induced stress in the halophyte plant model Thellungiella salsuginea compared to its glycophyte relative Arabidopsis thaliana: Cross talk and metabolite profiling.

    PubMed

    Shiri, Moez; Rabhi, Mokded; Abdelly, Chedly; Bouchereau, Alain; El Amrani, Abdelhak

    2016-07-01

    It was shown that halophytes experience higher cross-tolerance to stresses than glycophytes, which was often associated with their more powerful antioxidant systems. Moreover, salinity was reported to enhance halophyte tolerance to several stresses. The aim of the present work was to investigate whether a moderate salinity enhances phenanthrene stress tolerance in the halophyte Thellungiella salsuginea. The model plant Arabidopsis thaliana, considered as its glycophyte relative, was used as reference. Our study was based on morpho-physiological, antioxidant, and metabolomic parameters. Results showed that T. salsuginea was more tolerant to phenanthrene stress as compared to A. thaliana. An improvement of phenanthrene-induced responses was recorded in the two plants in the presence of 25 mM NaCl, but the effect was significantly more obvious in the halophyte. This observation was particularly related to the higher antioxidant activities and the induction of more adapted metabolism in the halophyte. Gas Chromatography coupled with Mass Spectrometry (GC-MS) was used to quantify alcohols, ammonium, sugars, and organic acids. It showed the accumulation of several metabolites, many of them are known to be involved in signaling and abiotic stress tolerance. Moderate salinity and phenanthrene cross-tolerance involved in these two stresses was discussed. PMID:27139124

  6. The ratios of dibenzothiophene to phenanthrene and pristane to phytane as indicators of depositional environment and lithology of petroleum source rocks

    NASA Astrophysics Data System (ADS)

    Hughes, William B.; Holba, Albert G.; Dzou, Leon I. P.

    1995-09-01

    The ratio of dibenzothiophene to phenanthrene and the ratio of pristane to phytane, when coupled together, provide a novel and convenient way to infer crude oil source rock depositional environments and lithologies. Such knowledge can significantly assist in identifying the source formation(s) in a basin thereby providing valuable guidance for further exploration. The ability to infer this information from analysis of a crude oil is especially valuable as frequently the earliest samples in a new area may be shows and/or drill stem test samples from exploratory wells which are characteristically drilled on structural highs stratigraphically remote from the source formation(s). A cross-plot of dibenzothiophene/phenanthrene versus the pristane/phytane ratios measured on seventy-five crude oils from forty-one known source rocks ranging in age from Ordovician to Miocene consistently classified the oils into the following environment/ lithology groups: marine carbonate; marine carbonate/ mixed and lacustrine sulfate-rich; lacustrine sulfate-poor; marine and lacustrine shale; and fluvial/deltaic carbonaceous shale and coal. The dibenzothiophene/phenanthrene ratio alone is an excellent indicator of source rock lithology with carbonates having ratios > 1 and shales having ratios < 1. The dibenzothiophene to phenanthrene and the pristane to phytane ratios can also be used to classify source rock paleodepositional environments. The classification scheme is based on the premise that these ratios reflect the different Eh-pH regimes resulting from the significant microbiological and chemical processes occurring during deposition and early diagenesis of sediments. The dibenzothiophene/phenanthrene ratio assesses the availability of reduced sulfur for incorporation into organic matter and the pristane/phytane ratio assesses the redox conditions within the depositional environment. Interpretation of these ratios has been aided by quantitative biomarker analysis and by carbon

  7. Isolation and characterization of catechol 2,3-dioxygenase genes from phenanthrene degraders Sphingomonas, sp. ZP1 and Pseudomonas sp. ZP2.

    PubMed

    Zhao, He-Ping; Liang, Sheng-Hua; Yang, Xiaoe

    2011-12-01

    Two bacterial strains, Sphingomonas sp. ZP1 and Pseudomonas stutzeri sp ZP2, were identified as having phenanthrene-degrading ability and were characterized. The activity of catechol-2,3-dioxygenase (C230) of both strains was measured. With degradation of phenanthrene with an initial concentration of 250 ppm, the C230 activity of both strain ZP1 and ZP2 increased. The ZP1 strain consumed all phenanthrene at day 6, and strain ZP2 degraded 250 ppm of phenanthrene at around day 5; C230 activity in strain ZP1 reached its peak of 6.92 U at day 6, and C230 activity in strain ZP2 achieved 7.80 U as its peak at day 5. After all phenanthrene (250ppm) was consumed, C230 activity in both Sphingomonas sp. ZP1 and Pseudomonas stutzeri ZP2 decreased. Analysis of the C230 gene sequence indicated that gene PhnZP1 from strain ZP1 has close sequence similarity with the C230 gene from the nearest strain Sphingomonas. sp. KMG 425 (98% identity), 97% similarity with the C230 gene catA from S. paucimobilis sp. TZS-7, and 94% similar with catE gene from S. sp. HV3. The sequence of the C230 gene PhnZP2 of strain ZP2 has 98% similarity with the cmpE gene from strain S. sp., 92% similarity with the phnE gene from P. sp. DJ77 strain, and 90% similarity with all selected C230 genes from Pseudomonas genus strains.

  8. Solution‐crystallization and related phenomena in 9,9‐dialkyl‐fluorene polymers. II. Influence of side‐chain structure

    PubMed Central

    Perevedentsev, Aleksandr; Stavrinou, Paul N.; Smith, Paul

    2015-01-01

    ABSTRACT Solution‐crystallization is studied for two polyfluorene polymers possessing different side‐chain structures. Thermal analysis and temperature‐dependent optical spectroscopy are used to clarify the nature of the crystallization process, while X‐ray diffraction and scanning electron microscopy reveal important differences in the resulting microstructures. It is shown that the planar‐zigzag chain conformation termed the β‐phase, which is observed for certain linear‐side‐chain polyfluorenes, is necessary for the formation of so‐called polymer‐solvent compounds for these polymers. Introduction of alternating fluorene repeat units with branched side‐chains prevents formation of the β‐phase conformation and results in non‐solvated, i.e. melt‐crystallization‐type, polymer crystals. Unlike non‐solvated polymer crystals, for which the chain conformation is stabilized by its incorporation into a crystalline lattice, the β‐phase conformation is stabilized by complexation with solvent molecules and, therefore, its formation does not require specific inter‐chain interactions. The presented results clarify the fundamental differences between the β‐phase and other conformational/crystalline forms of polyfluorenes. © 2015 The Authors. Journal of Polymer Science Part B: Polymer Physics published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1492–1506 PMID:27546983

  9. Experimental and theoretical study of crystal and molecular structure of 1,2-di(9H-fluoren-9-ylidene)hydrazine

    NASA Astrophysics Data System (ADS)

    Lasri, Jamal; Eltayeb, Naser Eltaher; Ismail, Ali I.

    2016-10-01

    The molecular structure and spectroscopic properties of 1,2-di(9H-fluoren-9-ylidene)hydrazine were studied experimentally by ESI-MS, FTIR, NMR and UV-Vis techniques and computationally by the density functional theory (DFT) method at B3LYP/6-31+G(d,p) level of theory. XRD single crystal showed that the molecule is crystalline as a monoclinic with space group P21/n, the crystal parameters are a, b, c (Å) 11.164(3), 5.9761(16) and 13.457(3), respectively. Also, β (°) and Z were found to be 103.822(12) and 2, respectively. The theoretical vibrational frequencies obtained by DFT calculations are in good agreement with the experimental values. TD-DFT calculations were carried out in both gas phase and in different solvent systems using polarizable continuum model (PCM) to calculate the electronic absorption spectra. GIAO method was used to calculate the NMR spectra in four different solvents CD3CN, CDCl3, DMSO-d6 and MeOD-d4. The correlation between the calculated and experimental chemical shifts was mostly in the range of 0.87-0.97 for 1H, whereas, the correlation for 13C in all solvents was 0.98.

  10. Atmospheric concentration and carcinogenic risk of polycyclic aromatic hydrocarbons including benzo[c]fluorene, cyclopenta[c,d]pyrene, and benzo[j]fluoranthene in Japan

    NASA Astrophysics Data System (ADS)

    Yagishita, Mayuko; Kageyama, Shiho; Ohshima, Shigeru; Matsumoto, Michi; Aoki, Yasunobu; Goto, Sumio; Nakajima, Daisuke

    2015-08-01

    The atmospheric concentrations of both gas-phase and particulate-phase polycyclic aromatic hydrocarbons (PAHs) including 16 US Environmental Protection Agency priority PAHs (16 PAHs) were measured in eleven cities across Japan. Using the measured average concentrations and toxic equivalency factors (TEF) of the 16 PAHs, the benzo[a]pyrene (BaP)-toxic equivalent for eight major PAHs was obtained: the ratio of BaP to the eight major PAH toxicities ranged from 0.23 to 0.47. Among the target PAHs, from the viewpoint of carcinogenicity, we focused on benzo[c]fluorene (BcFE), which was detected in both the gas and particulate phase in contrast to BaP. The relative potency factor (RPF) of BcFE was evaluated as 6.46 based on its cancer slope factor relative to that of BaP determined in the benchmark dose calculations for mice. The relative carcinogenic risk of BcFE to BaP was obtained by multiplying the averaged concentrations of BaP and BcFE by the RPF value: the risk of BcFE was 6.8 and 5.1 times higher than that of BaP in summer and winter, respectively. These results show that the collection of atmospheric samples including the gas phase is important when assessing the carcinogenic risk of atmospheric PAHs.

  11. Development of water quality criteria for phenanthrene and comparison of the sensitivity between native and non-native species.

    PubMed

    Wu, Jiang-Yue; Yan, Zhen-Guang; Liu, Zheng-Tao; Liu, Ji-dong; Liang, Feng; Wang, Xiao-Nan; Wang, Wei-Li

    2015-01-01

    Phenanthrene (PHE) is a priority polycyclic aromatic hydrocarbon (PAH) which is toxic to aquatic organisms.However, there has been no paper dealing with water quality criteria (WQC) of PHE due to the shortage of toxicity data of different taxonomic levels. In the present study, toxicity data were obtained from 8 acute toxicity tests and 3 chronic toxicity tests using 8 Chinese native aquatic species from different taxonomic levels, and the water quality criteria was derived using 3 methods. Furthermore, differences of species sensitivity distributions (SSDs) between native and non-native species were compared. A criterion maximum concentration of 0.0514 mg/L and a criterion continuous concentration of 0.0186 mg/L were developed according to the US EPA guidelines. Finally, by using risk quotient (RQ) to assess the site-specific ecological risk in Liao River, the results indicated that the PHE might pose no risk to local aquatic species. PMID:25463707

  12. Insight into sorption mechanism of phenanthrene onto gemini modified palygorskite through a multi-level fuzzy-factorial inference approach.

    PubMed

    Zhao, Shan; Huang, Gordon; Wang, Shuo; Wang, Xiuquan; Huang, Wendy

    2016-07-28

    A multi-level fuzzy-factorial inference approach was proposed to examine the sorption behavior of phenanthrene on palygorskite modified with a gemini surfactant. Fuzzy set theory was used to determine five experimentally controlled environmental factors with triangular membership functions, including initial concentration, added humid acid dose, ionic strength, temperature, and pH. The statistical significance of factors and their interactions affecting the sorption process was revealed through a multi-level factorial experiment. Initial concentration, ionic strength, and pH were identified as the most significant factors based on the multi-way ANOVA results. Examination of curvature effects of factors revealed the nonlinear complexity inherent in the sorption process. The potential interactions among experimental factors were detected, which is meaningful for providing a deep insight into the sorption mechanisms under the influences of factors at different levels. PMID:27163726

  13. Transportation and localization of phenanthrene and its interaction with different species of arsenic in Pteris vittata L.

    PubMed

    Liao, Xiaoyong; Ma, Xu; Yan, Xiulan; Lin, Longyong; Shi, Peili; Wu, Zeying

    2016-06-01

    The interaction between arsenic (As) and phenanthrene (PHE) in Pteris vittata L. was investigated in this study. The migration and occurrence of PHE in P. vittata were determined by two-photon laser scanning confocal microscopy. Data indicated that PHE supplementation lowers the As concentration in P. vittata, decreasing As levels by 16.8-39.9% in the pinnae, 30.0-49.0% in the rachis, and 45-51.5% in the roots, respectively. Different arsenic species inhibited P. vittata PHE absorption. The most significant effect was observed using dimethylarsenic acid (DMA), which decreased PHE accumulation by 20.73%. With the exception of elevated As(V) concentrations in As(III)-treated plants, PHE treatment significantly reduced inorganic As concentrations in P. vittata. However, PHE elevated root DMA concentrations by 9%. According to in situ visualization, PHE is primarily found in the upper and lower epidermis and stomatal cells, particularly the stomata guard cells. PMID:27023118

  14. Synthesis, stereochemistry and reactivity of the highly mutagenic bay-region diol epoxides from benzo(c)phenanthrene

    SciTech Connect

    Sayer, J.M.; Yagi, H.; Croisy-Delcey, M.; Jerina, D.M.

    1980-08-01

    Within the past six years, epoxides on saturated benzo-rings in which the epoxide group forms part of a sterically hindered bay-region of the polycyclic aromatic hydrocarbon molecule have been identified as ultimate carcinogenic metabolites of a number of hydrocarbons. Several of these observations led to the formulation of the bay-region theory, which predicts that bay-region epoxides which yield stable benzylic carbonium ions (as indicated by large values of ..delta..E/sub deloc/..beta.. is for the formation of these carbonium ions) will be active as tumorigens and/or mutagens when derived from carcinogenic hydrocarbons. This prediction is in good qualitative agreement with the decreasing order of tumorigenicity and mutagenicity for the biologically active diastereomers of the bay-region diol eoxides derived from benzo(a)pyrene, benzo(a)anthracene and its derivatives, and chrysene. Factors, in addition to carbonium ion stability, also play an essential role in determining the chemical and biological activity of these molecules; namely, S/sub N/2 reactivity, steric, stereoelectronic and conformational effects, hydrogen bonding, size, shape and hydrophobic character of the aromatic moiety, and possible complexation effects with biological macromolecules. As part of studies to assess the importance of these factors, we have investigated the diastereomeric diol epoxides (+)-3..cap alpha.., 4..beta..-dihydroxy-1..beta.., 2..beta..-epoxy-1,2,3,4,-tetrahydrobenzo(c)phenanthrene, 1 and (+)-3..cap alpha.., 4..beta..-dihydroxy-1..cap alpha.., 2..cap alpha..-epoxy-1,2,3,4-tetrahydrobenzo(c)phenanthrene, 2.

  15. Isolation of Marine Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Cycloclasticus Strains from the Gulf of Mexico and Comparison of Their PAH Degradation Ability with That of Puget Sound Cycloclasticus Strains

    PubMed Central

    Geiselbrecht, Allison D.; Hedlund, Brian P.; Tichi, Mary A.; Staley, J. T.

    1998-01-01

    Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 102 to 106 cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAH substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAH-degrading bacteria in both Puget Sound and the Gulf of Mexico. PMID:9835552

  16. Isolation of marine polycyclic aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and comparison of their PAH degradation ability with that of Puget Sound Cycloclasticus strains

    SciTech Connect

    Geiselbrecht, A.D.; Hedlund, B.P.; Tichi, M.A.; Staley, J.T.

    1998-12-01

    Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 10{sup 2} to 10{sup 6} cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and Phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAH substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAH-degrading bacteria in both Puget Sound and the Gulf of Mexico.

  17. Synthesis of novel fluorene-based two-photon absorbing molecules and their applications in optical data storage, microfabrication, and stimulated emission depletion

    NASA Astrophysics Data System (ADS)

    Yanez, Ciceron

    2009-12-01

    Two-photon absorption (2PA) has been used for a number of scientific and technological applications, exploiting the fact that the 2PA probability is directly proportional to the square of the incident light intensity (while one-photon absorption bears a linear relation to the incident light intensity). This intrinsic property of 2PA leads to 3D spatial localization, important in fields such as optical data storage, fluorescence microscopy, and 3D microfabrication. The spatial confinement that 2PA enables has been used to induce photochemical and photophysical events in increasingly smaller volumes and allowed nonlinear, 2PA-based, technologies to reach sub-diffraction limit resolutions. The primary focus of this dissertation is the development of novel, efficient 2PA, fluorene-based molecules to be used either as photoacid generators (PAGs) or fluorophores. A second aim is to develop more effective methods of synthesizing these compounds. As a third and final objective, the new molecules were used to develop a write-once-read many (WORM) optical data storage system, and stimulated emission depletion probes for bioimaging. In Chapter I, the microwave-assisted synthesis of triarylsulfonium salt photoacid generators (PAGs) from their diphenyliodonium counterparts is reported. The microwave-assisted synthesis of these novel sulfonium salts afforded reaction times 90 to 420 times faster than conventional thermal conditions, with photoacid quantum yields of new sulfonium PAGs ranging from 0.01 to 0.4. These PAGs were used to develop a fluorescence readout-based, nonlinear three-dimensional (3D) optical data storage system (Chapter II). In this system, writing was achieved by acid generation upon two-photon absorption (2PA) of a PAG (at 710 or 730 nm). Readout was then performed by interrogating two-photon absorbing dyes, after protonation, at 860 nm. Two-photon recording and readout of voxels was demonstrated in five and eight consecutive, crosstalk-free layers within a

  18. A soluble ladder-conjugated star-shaped oligomer composed of four perylene diimide branches and a fluorene core: synthesis and properties.

    PubMed

    Zhang, Youdi; Chen, Lingcheng; Zhang, Kaichen; Wang, Helin; Xiao, Yi

    2014-08-01

    A new ladder-conjugated star-shaped oligomer electron-transporting material TetraPDI-PF, with four perylene diimide (PDI) branches and a fluorene core, was efficiently synthesized. The oligomer is highly soluble in dichlorobenzene with a solubility of 155 mg mL(-1), which is higher than those of PDI (35 mg mL(-1)) and PDI-Phen (70 mg mL(-1)). Demonstrated by thermogravimetric analysis (TGA), the oligomer exhibits excellent thermal stability with the decomposition temperature (Td) of 291.2 °C, which is 65 °C higher than that of PDI. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to investigate the electrochemical properties. Although the CV curves of TetraPDI-PF are successively scanned for 15 cycles, they still remain invariable reduction potentials. The oligomer also shows outstanding photostability, even better than PDI, which maintains 99 % fluorescence intensity after irradiation for 10 min using maximum laser intensity. In the steady-state space-charge-limited current (SCLC) devices, TetraPDI-PF exhibits higher intrinsic electron mobility of 2.22×10(-5) cm(2)  V(-1)  s(-1), three orders of magnitude over that of PDI (3.52×10(-8) cm(2)  V(-1)  s(-1)). The bulk heterojunction (BHJ) organic solar cells (OSCs) using TetraPDI-PF as non-fullerene acceptors and P3HT as donors give optimum power conversion efficiency (PCE) of 0.64 %, which is 64 times that of the PDI:P3HT BHJ cells.

  19. Assessment of bile fluorescence patterns in a tropical fish, Nile tilapia (Oreochromis niloticus) exposed to naphthalene, phenanthrene, pyrene and chrysene using fixed wavelength fluorescence and synchronous fluorescence spectrometry.

    PubMed

    Pathiratne, A; Hemachandra, C K; Pathiratne, K A S

    2010-05-01

    Bile fluorescence patterns in Nile tilapia, a potential fish for biomonitoring tropical water pollution were assessed following exposure to selected polycyclic aromatic hydrocarbons (PAHs): naphthalene, phenanthrene, pyrene and chrysene. Non-normalized fixed wavelength fluorescence signals in the fish exposed to these PAHs reflected dose and/or time response relationships of their metabolism. Normalizing signals to biliverdin introduced deviations to these response patterns. The optimal wavelength pairs (excitation/emission) for synchronous fluorescence scanning measurements of bile metabolites of naphthalene, phenanthrene, pyrene and chrysene were identified as 284/326, 252/357, 340/382 and 273/382 respectively. This study supports the use of bile fluorescence in Nile tilapia by fixed wavelength fluorescence and synchronous fluorescence spectrometry with non-normalized data as a simple method for screening bioavailability of these PAHs.

  20. Antitumor agents 251: synthesis, cytotoxic evaluation, and structure-activity relationship studies of phenanthrene-based tylophorine derivatives (PBTs) as a new class of antitumor agents.

    PubMed

    Wei, Linyi; Brossi, Arnold; Kendall, Ross; Bastow, Kenneth F; Morris-Natschke, Susan L; Shi, Qian; Lee, Kuo-Hsiung

    2006-10-01

    Polar phenanthrene-based tylophorine derivatives (PBTs) were designed, synthesized and evaluated as potential antitumor agents. These compounds contain a core phenanthrene structure and can be synthesized efficiently in excellent yield. The newly synthesized PBTs were evaluated for cytotoxic activity against the A549 human cancer cell line. Among them, N-(2,3-methylenedioxy-6-methoxy-phenanthr-9-ylmethyl)-L-2-piperidinemethanol (34) and N-(2,3-methylenedioxy-6-methoxy-phenanthr-9-ylmethyl)-5-aminopentanol (28) showed the highest potency with IC50 values of 0.16 and 0.27 microM, respectively, which are comparable to those of currently used antitumor drugs. A structure-activity relationship (SAR) study was also explored to facilitate the further development of this new compound class.

  1. Effects of nonionic surfactants on the microbial mineralization of phenanthrene in soil-water systems. [Surfactants used: alkylethoxylate and alkylphenol ethoxylate

    SciTech Connect

    Laha, S.; Luthy, R.G.

    1992-01-01

    The purpose of the work reported in this paper was to determine whether the inhibitory effect on microbial degradation of phenanthrene was specific to the nonionic surfactants used previously, i.e., the alkylethoxylate and alkylphenol ethoxylate surfactants. Thus, a number of nonionic surfactants of varying structures and properties were selected for further investigation. In addition, several tests were performed to verify results from earlier experiments.

  2. Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil.

    PubMed

    Song, Mengke; Jiang, Longfei; Zhang, Dayi; Luo, Chunling; Wang, Yan; Yu, Zhiqiang; Yin, Hua; Zhang, Gan

    2016-05-01

    Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually (13)C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota. PMID:26808242

  3. Short-Term Rhizosphere Effect on Available Carbon Sources, Phenanthrene Degradation, and Active Microbiome in an Aged-Contaminated Industrial Soil

    PubMed Central

    Thomas, François; Cébron, Aurélie

    2016-01-01

    Over the last decades, understanding of the effects of plants on soil microbiomes has greatly advanced. However, knowledge on the assembly of rhizospheric communities in aged-contaminated industrial soils is still limited, especially with regard to transcriptionally active microbiomes and their link to the quality or quantity of carbon sources. We compared the short-term (2–10 days) dynamics of bacterial communities and potential PAH-degrading bacteria in bare or ryegrass-planted aged-contaminated soil spiked with phenanthrene, put in relation with dissolved organic carbon (DOC) sources and polycyclic aromatic hydrocarbon (PAH) pollution. Both resident and active bacterial communities (analyzed from DNA and RNA, respectively) showed higher species richness and smaller dispersion between replicates in planted soils. Root development strongly favored the activity of Pseudomonadales within the first 2 days, and of members of Actinobacteria, Caulobacterales, Rhizobiales, and Xanthomonadales within 6–10 days. Plants slowed down the dissipation of phenanthrene, while root exudation provided a cocktail of labile substrates that might preferentially fuel microbial growth. Although the abundance of PAH-degrading genes increased in planted soil, their transcription level stayed similar to bare soil. In addition, network analysis revealed that plants induced an early shift in the identity of potential phenanthrene degraders, which might influence PAH dissipation on the long-term. PMID:26903971

  4. Effect of surfactant-induced cell surface modifications on electron transport system and catechol 1,2-dioxygenase activities and phenanthrene biodegradation by Citrobacter sp. SA01.

    PubMed

    Li, Feng; Zhu, Lizhong

    2012-11-01

    In order to better understand how surfactants affect biodegradation of hydrophobic organic compounds (HOCs), Tween 80 and sodium dodecyl benzene sulfonate (SDBS), were selected to investigate effects on cell surface hydrophobicity (CSH), electron transport system (ETS) activities and phenanthrene biodegradation by Citrobacter sp. SA01. Tween 80 and SDBS increased CSH by 19.8-25.2%, ETS activities by 352.1-376.0μmol/gmin, catechol 1,2-dioxygenase (C12) activities by 50.8-52.7U/L, and phenanthrene biodegradation by 8.9-17.2% separately in the presence of 50mg/L of surfactants as compared to in their absence. Lipopolysaccharide (LPS) release was 334.7μg/mg in the presence of both surfactants whereas in their absence only 8.6-44.4μg/mg of LPS was released. Thus, enhanced LPS release probably increased ETS and C12 activities as well as phenanthrene biodegradation by increasing CSH. The results demonstrate that surfactant-enhanced CSH provides a simple, yet effective strategy for field applications of surfactant-enhanced bioremediation of HOCs.

  5. Impact of phenanthrene on the properties of biogeochemical interfaces in soil: A two-layer column study

    NASA Astrophysics Data System (ADS)

    Reichel, Katharina; Totsche, Kai Uwe

    2013-04-01

    Biogeochemical interfaces in soils (Totsche et al. 2010) are the "hot spots" of microbial activity and the processing of organic compounds in soils. The production and relocation of mobile organic matter (MOM) and biocolloids like microorganisms are key processes for the formation and depth propagation of biogeochemical interfaces in soils (BGI). Phenanthrene (PHE) has been shown to affect microbial communities in soils (Ding et al. 2012) and may induce shifts in MOM quantity and quality (amount, type and properties of MOM). We hypothesize that the properties of BGI in soil change significantly due to the presence of PHE. The objectives of this study are (i) to evaluate the effect of PHE on soil microbial communities and on MOM quantity and quality under flow conditions with single- and two-layer column experiments and (ii) to assess the role of these processes for the physicochemical, mechanical and sorptive properties of BGI in soils. The soil columns were operated under water-unsaturated conditions. The top layer (source layer, SL, 2 cm) is made of sieved soil material (Luvisol, Scheyern, Germany) spiked with PHE (0.2 mg/g). The bottom layer (reception layer, RL, 10 cm) comprised the same soil without PHE. PHE-free columns were conducted in parallel as reference. Release and transport of MOM in mature soil of a single-layer column experiment was found to depend on the transport regime. The release of larger sized MOM (>0.45 µm) was restricted to an increased residence time during flow interruptions. Steady flow conditions favor the release of smaller MOM (<0.45 µm). Compared to the reference, in the two-layer column experiments higher OC concentrations were detected in the effluent from PHE spiked columns after enhanced flow interruptions (26d, 52d). That indicated the PHE influenced production or mobilization of MOM. Parallel factor analysis of fluorescence excitation and emission matrices revealed the presence of a constant DOM background and two new unknown

  6. Focused ion beam and field-emission microscopy of metallic filaments in memory devices based on thin films of an ambipolar organic compound consisting of oxadiazole, carbazole, and fluorene units

    USGS Publications Warehouse

    Pearson, Christopher; Bowen, Leon; Lee, Myung Won; Fisher, Alison L.; Linton, Katherine E.; Bryce, Martin R.; Petty, Michael C.

    2013-01-01

    We report on the mechanism of operation of organic thin film resistive memory architectures based on an ambipolar compound consisting of oxadiazole, carbazole, and fluorene units. Cross-sections of the devices have been imaged by electron microscopy both before and after applying a voltage. The micrographs reveal the growth of filaments, with diameters of 50 nm–100 nm, on the metal cathode. We suggest that these are formed by the drift of aluminium ions from the anode and are responsible for the observed switching and negative differential resistance phenomena in the memory devices.

  7. Toxicity of combined chromium(VI) and phenanthrene pollution on the seed germination, stem lengths, and fresh weights of higher plants.

    PubMed

    Hu, Shuangqing; Gu, Hairong; Cui, Chunyan; Ji, Rong

    2016-08-01

    Studies of the interaction and toxicity of pollutant combinations such as heavy metals and PAHs are of practical importance in the remediation and monitoring of the industrial soil environment. This study investigated the single and combined toxicity of chromium(VI) and phenanthrene on three important higher plants: mung beans (Phaseolus aureus), pakchoi cabbage (Brassica chinensis), and rice (Oryza sativa). In experiments using artificial soil matrix, the EC10 and EC20 of the two pollutants, alone and in combination, were analyzed with respect to seed germination, stem length, and above-ground fresh weight of these higher plants. The additive index method was used to evaluate the combined biological toxicity of chromium(VI) and phenanthrene. The results showed that the EC20 of chromium(VI) on the stem lengths of mung beans, pakchoi cabbage, and rice was 289, 248, and 550 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 334, 307, and 551 mg kg(-1). The EC20 of phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 528, 426, and 628 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 696, 585, and 768 mg kg(-1). The EC20 of a combination of chromium(VI) and phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 192, 173, and 279 mg kg(-1), respectively, and 200, 205, and 271 mg kg(-1) for the fresh weights of the three plants. The single and combined exposure of soil to chromium(VI) and phenanthrene had deleterious effects on plants in the early stage of growth. Overall, pakchoi cabbage was more sensitive than mung beans and rice. The two pollutants exerted synergistic effects on the stem lengths and above-ground fresh weights of both mung beans and rice but antagonistic effects on pakchoi cabbage. The results of this study also suggested pakchoi cabbage as a sensitive indicator of soil pollution.

  8. Toxicity of combined chromium(VI) and phenanthrene pollution on the seed germination, stem lengths, and fresh weights of higher plants.

    PubMed

    Hu, Shuangqing; Gu, Hairong; Cui, Chunyan; Ji, Rong

    2016-08-01

    Studies of the interaction and toxicity of pollutant combinations such as heavy metals and PAHs are of practical importance in the remediation and monitoring of the industrial soil environment. This study investigated the single and combined toxicity of chromium(VI) and phenanthrene on three important higher plants: mung beans (Phaseolus aureus), pakchoi cabbage (Brassica chinensis), and rice (Oryza sativa). In experiments using artificial soil matrix, the EC10 and EC20 of the two pollutants, alone and in combination, were analyzed with respect to seed germination, stem length, and above-ground fresh weight of these higher plants. The additive index method was used to evaluate the combined biological toxicity of chromium(VI) and phenanthrene. The results showed that the EC20 of chromium(VI) on the stem lengths of mung beans, pakchoi cabbage, and rice was 289, 248, and 550 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 334, 307, and 551 mg kg(-1). The EC20 of phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 528, 426, and 628 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 696, 585, and 768 mg kg(-1). The EC20 of a combination of chromium(VI) and phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 192, 173, and 279 mg kg(-1), respectively, and 200, 205, and 271 mg kg(-1) for the fresh weights of the three plants. The single and combined exposure of soil to chromium(VI) and phenanthrene had deleterious effects on plants in the early stage of growth. Overall, pakchoi cabbage was more sensitive than mung beans and rice. The two pollutants exerted synergistic effects on the stem lengths and above-ground fresh weights of both mung beans and rice but antagonistic effects on pakchoi cabbage. The results of this study also suggested pakchoi cabbage as a sensitive indicator of soil pollution. PMID

  9. Efficient biodegradation of phenanthrene by a novel strain Massilia sp. WF1 isolated from a PAH-contaminated soil.

    PubMed

    Wang, Haizhen; Lou, Jun; Gu, Haiping; Luo, Xiaoyan; Yang, Li; Wu, Laosheng; Liu, Yong; Wu, Jianjun; Xu, Jianming

    2016-07-01

    A novel phenanthrene (PHE)-degrading strain Massilia sp. WF1, isolated from PAH-contaminated soil, was capable of degrading PHE by using it as the sole carbon source and energy in a range of pH (5.0-8.0), temperatures (20-35 °C), and PHE concentrations (25-400 mg L(-1)). Massilia sp. WF1 exhibited highly effective PHE-degrading ability that completely degraded 100 mg L(-1) of PHE over 2 days at optimal conditions (pH 6.0, 28 °C). The kinetics of PHE biodegradation by Massilia sp. WF1 was well represented by the Gompertz model. Results indicated that PHE biodegradation was inhibited by the supplied lactic acid but was promoted by the supplied carbon sources of glucose, citric acid, and succinic acid. Salicylic acid (SALA) and phthalic acid (PHTA) were not utilized by Massilia sp. WF1 and had no obvious effect on PHE biodegradation. Only two metabolites, 1-hydroxy-2-naphthoic acid (1H2N) and PHTA, were identified in PHE biodegradation process. Quantitatively, nearly 27.7 % of PHE was converted to 1H2N and 30.3 % of 1H2N was further metabolized to PHTA. However, the PHTA pathway was broken and the SALA pathway was ruled out in PHE biodegradation process by Massilia sp. WF1. PMID:27026540

  10. Properties of the plant- and manure-derived biochars and their sorption of dibutyl phthalate and phenanthrene

    PubMed Central

    Qiu, Mengyi; Sun, Ke; Jin, Jie; Gao, Bo; Yan, Yu; Han, Lanfang; Wu, Fengchang; Xing, Baoshan

    2014-01-01

    The properties of plant residue-derived biochars (PLABs) and animal waste-derived biochars (ANIBs) obtained at low and high heating treatment temperatures (300 and 450°C) as well as their sorption of dibutyl phthalate (DBP) and phenanthrene (PHE) were investigated in this study. The higher C content of PLABs could explain that CO2-surface area (CO2-SA) of PLABs was remarkably high relative to ANIBs. OC and aromatic C were two key factors influencing the CO2-SA of the biochars. Much higher surface C content of the ANIBs than bulk C likely explained that the ANIBs exhibited higher sorption of DBP and PHE compared to the PLABs. H-bonding should govern the adsorption of DBP by most of the tested biochars and π-π interaction play an important role in the adsorption of PHE by biochars. High CO2-SA (>200 m2 g−1) demonstrated that abundant nanopores of OC existed within the biochars obtained 450°C (HTBs), which likely result in high and nonlinear sorption of PHE by HTBs. PMID:24924925

  11. Dependence of phenanthrene dissipation in mangrove sediment on the distance to root surface of Kandelia obovata L.

    PubMed

    Fang, Yu; Yan, Chong-Ling; Du, Jing-Na; Yu, Jun-Yi

    2012-07-01

    We explored the relationship between the distance from roots and rhizosphere-mediated phenanthrene (PHE) dissipation in planted mangrove sediment. A compartmentalized device (rhizobox) was used that separated root surface and four consecutive rhizosphere layers that extended 0-2, 2-4, 4-6, and >6 mm away from the root surface. Kandelia obovata L. Druce seedlings were grown for 4 months in sediment spiked with 10 mgkg(-1) PHE. PHE dissipation, microbial community structure and enzymatic activities at millimeter scale in the vicinity of plant roots were analyzed. Results indicated significant differences in PHE dissipation through the various layers in the planted rhizobox. PHE dissipation exhibited the most rapid loss in the 0-2 mm near-rhizosphere layer, the lowest in far-rhizosphere (>6 mm) layer. Microbial community structure as indicated by denaturing gradient gel electrophoresis (DGGE) profiles showed that special bacterial species and larger bacterial numbers were observed in near-rhizosphere layers. Depending on the distance to root surface, near-rhizosphere bacterial species and enzymatic activities were more abundant than root compartment and far-rhizosphere, resulting in rapid dissipation of PHE. PMID:22908629

  12. In silico understanding of the cyclodextrin-phenanthrene hybrid assemblies in both aqueous medium and bacterial membranes.

    PubMed

    Ren, Baiping; Gao, Huipeng; Cao, Yafeng; Jia, Lingyun

    2015-03-21

    The explicit-solvent molecular dynamic (MD) simulation and adaptive biased forces (ABF) methods were employed to systemically study the structural and thermodynamic nature of the β-cyclodextrin (βCD) monomer, phenanthrene (Phe) monomer, and their inclusion complexes in both the aqueous and membrane environments, aiming at clarifying the atomic-level mechanisms underlying in the CD-enhanced degradation of polycyclic aromatic hydrocarbons (PAHs) by bacteria. Simulations showed that βCD and Phe monomers could associate together to construct two distinctive assemblies, i.e, βCD1-Phe1 and βCD2-Phe1, respectively. The membrane-involved equilibrium simulations and the data of potential of mean forces (PMFs) further confirmed that Phe monomer was capable of penetrating through the membranes without confronting any large energy barrier, whereas, the single βCD and βCD-involved assemblies were unable to pass across the membranes. These observations clearly suggested that βCD only served as the carrier to enhance the bioavailability of Phe rather than the co-substrate in the Phe biodegradation process. The Phe-separation PMF profiles indicated that the maximum of the Phe uptake by bacteria would be achieved by the "optimal" βCD:Phe molar ratio, which facilitated the maximal formation of βCD1-Phe1 inclusion and the minimal construction of βCD2-Phe1 complex. PMID:25497028

  13. Solubility and partial molar volumes of naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene in supercritical carbon dioxide

    SciTech Connect

    Goenenc, Z.S.; Akman, U. |; Sunol, A.K.

    1995-07-01

    The effect of temperature, pressure, and supercritical fluid density on the retention and solubility in the mobile phase of solutes in supercritical fluid chromatography was investigated. New retention data for naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene were obtained as a function of pressure at different temperatures. Most of the data were taken near the critical region of the fluid phase where the anomalities such as enhanced solubility/selectivity and retrogate behavior are expected. These data were then used to compare two different approaches for modeling the pressure dependence of solute retention on the column. In these approaches, mobile-phase partial molar volumes of the solutes were determined either from bulk solubility data or from infinite-dilution fugacity coefficients. In both approaches, an integrated expression for the change of retention with pressure was utilized to explicitly reveal the nature of interactions between the stationary phase and the solute. The approach that utilizes the infinite-dilution fugacity coefficient predicts the pressure dependence of solute retention more accurately, especially for solutes that are substantially soluble in the mobile phase near the critical point of the mobile phase. Relationships between the pressure and temperature dependence of the solute solubility in the mobile phase and the retention of solutes on the column were also investigated.

  14. Sorption of bisphenol A, 17α-ethinyl estradiol and phenanthrene on thermally and hydrothermally produced biochars.

    PubMed

    Sun, Ke; Ro, Kyoung; Guo, Mingxin; Novak, Jeff; Mashayekhi, Hamid; Xing, Baoshan

    2011-05-01

    Thermal and hydrothermal biochars were characterized, and adsorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and phenanthrene (Phen) was determined to investigate the sorption characteristic difference between the two types of biochars. Thermal biochars were composed mostly of aromatic moieties, with low H/C and O/C ratios as compared to hydrothermal ones having diverse functional groups. Single-point organic carbon-normalized distribution coefficients (logK(OC)) of EE2 and BPA of hydrothermal biochars were higher than thermal biochars, while Phen logK(OC) values were comparable among them. X-ray diffraction and solid state nuclear magnetic resonance results suggested that hydrothermal biochars consisted of more amorphous aliphatic-C, possibly being responsible for their high sorption capacity of Phen. This study demonstrated that hydrothermal biochars could adsorb a wider spectrum of both polar and nonpolar organic contaminants than thermally produced biochars, suggesting that hydrothermal biochar derived from poultry and animal waste is a potential sorbent for agricultural and environmental applications.

  15. Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011').

    PubMed

    Sun, Y Y; Xu, H X; Li, J H; Shi, X Q; Wu, J C; Ji, R; Guo, H Y

    2016-01-01

    To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

  16. Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

    PubMed

    Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

    2016-04-01

    Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils. PMID:26683200

  17. Structural and Functional Diversities of the Hexadecahydro-1H-cyclopenta[a]phenanthrene Framework, a Ubiquitous Scaffold in Steroidal Hormones.

    PubMed

    Choudhury, Chinmayee; Deva Priyakumar, U; Narahari Sastry, G

    2016-04-01

    Hexadecahydro-1H-cyclopenta[a]phenanthrene framework (HHCPF) has been considered as one of the privileged scaffolds due to its versatile presence in many biologically essential molecules. In our quest to unravel the privileged nature of this framework, we undertook a systematic analysis of target binding and Absorption, Distribution, Metabolism, Elimination, Toxicity (ADMET)/physicochemical properties of 110 drugs containing HHCPF reported in DrugBank. Effect of number and positions of double bonds in the framework and substitutions at each carbon position on the target selectivity as well as drug like properties of these drugs were studied. Fifteen different scaffolds based on the numbers and positions of double bonds in the HHCPF were identified among these drugs. The optimum number of double bonds present in the HHCPF scaffolds was observed to be one to three, and one particular positional isomer is predominant among many scaffolds with same numbers of double bonds. Docking studies reveal the role of substituents at different positions to make specific interactions with their respective targets. Based on the docking interactions, we proposed structure based e-Pharmacophore models for seven important targets of HHCPF drugs. Good correlations were observed between the substitutions carbon positions 3 and 17 of the scaffolds and ADMET properties of the HHCPF drugs. This work enables preliminary prediction of the target selectivity and ADMET properties of a new HHCPF molecule based on the scaffold, substituents and the pharmacophoric features. PMID:27491924

  18. Variability in antioxidant/detoxification enzymes of Sinonovacula constricta exposed to benzo[a]pyrene and phenanthrene.

    PubMed

    Li, Lei; Jiang, Mei; Shen, Xinqiang

    2016-08-15

    The purpose of this study was to investigate the toxic effects induced by benzo[a]pyrene and phenanthrene. For this purpose, a study was performed on the clam exposed to 0.0, 0.5, 4.5μgL(-1) B(a)P and PHE for 15days using parameters of antioxidant defenses and oxidative stress. Antioxidant biomarkers including ethoxyresorufin-O-deethylase, glutathione S-transferase, superoxide dismutase, and glutathione and rylhydrocarbon hydroxylasein gills of Sinonovacula constricta, were analyzed after a 1-, 3-, 9- and 15-day exposure to seawater containing B(a)P and PHE. Integrated biomarker response was calculated by combining multiple biomarkers into a single value. The results showed that the activity of all antioxidant biomarkers was induced throughout the exposure period, and different patterns of variations were detected with exposure time. In addition, the study showed that the two concentrations used caused the activation of different general detoxification mechanisms, and the same concentration at different two PAH compounds induced different toxicity responses. PMID:27216044

  19. On the molecular structure of (E)-3-(9H-fluoren-2-yl)-1-(pyridin-2-yl)prop-2-en-1-one, theoretical calculations and SXRD studies

    NASA Astrophysics Data System (ADS)

    Labra-Vázquez, Pablo; Lugo-Aranda, Alejandra Zaavik; Maldonado-Domínguez, Mauricio; Arcos-Ramos, Rafael; Carreon-Castro, María del Pilar; Santillan, Rosa; Farfán, Norberto

    2015-12-01

    The azachalcone, (E)-3-(9H-fluoren-2-yl)-1-(pyridin-2-yl)prop-2-en-1-one (C21H15NO) (3) was synthesized by classical Claisen-Schmidt condensation reaction. An E-configuration was confirmed through single-crystal X-Ray diffraction studies; crystallizing in monoclinic space group P 21/c, with unit cell parameters a = 16.115 Å (3), b = 12.277 Å (3), c = 7.6884 Å (15) and Z = 4. Our approach to correlate the experimental molecular structure with the NMR assignment of this azachalcone comprised DFT computations of magnetic shielding, coupled with 2D-NMR spectroscopy. With a correlation of R2 = 0.9965 between experimental and computed 13C-NMR chemical shifts, this strategy allowed the full 13C assignment of the azachalcone π-system. The molecular structure was topologically analyzed within the framework of the quantum theory of atoms in molecules; π-stacking and donor-acceptor π contacts are involved in the crystal packing of (E)-3-(9H-fluoren-2-yl)-1-(pyridin-2-yl)prop-2-en-1-one (3).

  20. Biodegradation, Biosorption of Phenanthrene and Its Trans-Membrane Transport by Massilia sp. WF1 and Phanerochaete chrysosporium

    PubMed Central

    Gu, Haiping; Lou, Jun; Wang, Haizhen; Yang, Yu; Wu, Laosheng; Wu, Jianjun; Xu, Jianming

    2016-01-01

    Reducing phenanthrene (PHE) in the environment is critical to ecosystem and human health. Biodegradation, biosorption, and the trans-membrane transport mechanism of PHE by a novel strain, Massilia sp. WF1, and an extensively researched model fungus, Phanerochaete chrysosporium were investigated in aqueous solutions. Results showed that the PHE residual concentration decreased with incubation time and the data fitted well to a first-order kinetic equation, and the t1/2 of PHE degradation by WF1, spores, and mycelial pellets of P. chrysosporium were about 2 h, 87 days, and 87 days, respectively. The biosorbed PHE was higher in P. Chrysosporium than that in WF1, and it increased after microorganisms were inactivated and inhibited, especially in mycelial pellets. The detected intracellular auto-fluorescence of PHE by two-photon excitation microscopy also proved that PHE indeed entered into the cells. Based on regression, the intracellular (Kdin) and extracellular (Kdout) dissipation rate constants of PHE by WF1 were higher than those by spores and mycelial pellets. In addition, the transport rate constant of PHE from outside solution into cells (KinS/Vout) for WF1 were higher than the efflux rate constant of PHE from cells to outside solution (KoutS/Vin), while the opposite phenomena were observed for spores and mycelial pellets. The amount of PHE that transported from outside solution into cells was attributed to the rapid degradation and active PHE efflux in the cells of WF1 and P. Chrysosporium, respectively. Besides, the results under the inhibition treatments of 4°C, and the presence of sodium azide, colchicine, and cytochalasin B demonstrated that a passive trans-membrane transport mechanism was involved in PHE entering into the cells of WF1 and P. Chrysosporium. PMID:26858710

  1. Effects of sterile storage, cation saturation and substrate additions on the degradability and extractability of nonylphenol and phenanthrene in soil.

    PubMed

    Shchegolikhina, Anastasia; Marschner, Bernd

    2013-11-01

    The main objective of this study was to determine the effects of long-term abiotic processes during aging of organic pollutants in soil on their microbial degradability and formation of non-extractable residues. The specific aims of our study were to investigate how the fate of p353-nonylphenol (NP) and phenanthrene (Phe) in soils might be affected by: (i) saturation of soil by cations with different valency (Na(+), Ca(2+) or Al(3+)), (ii) addition of organic substrate (wood flour) during incubation period and (iii) different soil moisture levels. This study showed positive effect of long-term aging of sterilized samples on respiration of re-inoculated samples. However, the lack of aging effects on the mineralization of NP and Phe indicates that slow sorption processes by diffusion into less bioaccessible domains were not relevant in studied soils. Similarly, the lower respiration and xenobiotic mineralization rates in the Na(+) and Al(3+) treated soils indicate that this is due to toxic effects on microbial activity and not due to xenobiotic accessibility. Instead, the formation of non-extractable residues was strongly promoted by biological activity, most likely through formation of more reactive metabolites. The addition of wood flour greatly stimulated microbial respiration and enhanced NP mineralization while inhibiting that of Phe. Along with negligible effect of water addition after 4 weeks of incubation on kinetics of soil respiration, the soil moisture effect on xenobiotics mineralization indicates that most probably the bioavailability of NP and Phe increased due to bridging role of water films in soil.

  2. Role of brassinosteroids in alleviation of phenanthrene-cadmium co-contamination-induced photosynthetic inhibition and oxidative stress in tomato.

    PubMed

    Ahammed, Golam Jalal; Choudhary, Sikander Pal; Chen, Shuangchen; Xia, Xiaojian; Shi, Kai; Zhou, Yanhong; Yu, Jingquan

    2013-01-01

    Heavy metal pollution often occurs together with organic contaminants. Brassinosteroids (BRs) induce plant tolerance to several abiotic stresses, including phenanthrene (PHE) and cadmium (Cd) stress. However, the role of BRs in PHE+Cd co-contamination-induced stress amelioration is unknown. Here, the interactive effects of PHE, Cd, and 24-epibrassinolide (EBR; a biologically active BR) were investigated in tomato plants. The application of Cd (100 µM) alone was more phytotoxic than PHE applied alone (100 µM); however, their combined application resulted in slightly improved photosynthetic activity and pigment content compared with Cd alone after a 40 d exposure. Accumulation of reactive oxygen species and membrane lipid peroxidation were induced by PHE and/or Cd; however, the differences in effect were insignificant between Cd and PHE+Cd. The foliar application of EBR (0.1 µM) to PHE- and/or Cd-stressed plants alleviated photosynthetic inhibition and oxidative stress by causing enhancement of the activity of the enzymes and related transcript levels of the antioxidant system, secondary metabolism, and the xenobiotic detoxification system. Additionally, PHE and/or Cd residues were significantly decreased in both the leaves and roots after application of EBR, more specifically in PHE+Cd-stressed plants when treated with EBR, indicating a possible improvement in detoxification of these pollutants. The findings thus suggest a potential interaction of EBR and PHE for Cd stress alleviation. These results advocate a positive role for EBR in reducing pollutant residues for food safety and also strengthening phytoremediation.

  3. Comparison of polycyclic aromatic hydrocarbons level between suspended solid and sediment samples of Pengkalan Chepa River, Kelantan state, Malaysia

    NASA Astrophysics Data System (ADS)

    Muslim, Noor Zuhartini Md; Babaheidari, Seyedreza Hashemi; Zakaria, Mohamad Pauzi

    2015-09-01

    Sixteen type of common Polycyclic Aromatic Hydrocarbons (PAHs) which consist of naphthalene, acenaphthene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]-perylene, indeno[1,2,3-cd]-pyrene and dibenz[a,h]-anthracene in suspended solid and sediment samples of Pengkalan Chepa River, Kelantan state, Malaysia were investigated. The analysis samples were taken from six different sites of Pengkalan Chepa River during sunny day. The samples were subjected to a series of pre-treatment before the level of PAHs can be determined. A Gas Chromatography-Mass Spectrometry (GC-MS) was the prime method for the analysis of PAHs level. A total of 16 PAHs concentration in suspended solid of the whole Pengkalan Chepa River was found to be 2144.6 ng/g dry weights. This concentration was about eight times more than 16 PAHs concentration in sediment which found to be 266.5 ng/g dry weights.

  4. Toxicity evaluation of PAH mixtures using Microtox

    SciTech Connect

    Thompkins, J.; Guthrie, E.; Pfaender, F.

    1995-12-31

    Polycyclic aromatic hydrocarbons (PAH) are produced from both natural and anthropogenic combustion processes. PAHs are known to be toxic and carcinogenic, are prevalent at many hazardous waste sites, and pose a potential risk to both ecological and human health. To date, few researchers have assessed the toxicity of polycyclic aromatic hydrocarbon (PAH) mixtures. The toxicity of chrysene, anthracene, pyrene, phenanthrene, fluoranthrene, acenaphthene, fluorene, and naphthalene were evaluated using Microtox, and acute toxicity assay that uses bioluminescent bacteria, Photobacterium phosphoreum, to measure toxicity. In this study, the toxicities of 2, 3, and 4 ring PAHs were determined for individual compounds. Synergistic or additive effects of PAH mixtures was assessed by comparing the toxicity of mixtures with that of pure compounds. Each PAH or mixture was evaluated at their respective water solubility concentrations, For individual PAHs tested, the toxicity of PAHs is inversely related to water solubility. Mixtures of two and three PAHs with disparate water solubilities resulted in synergistic interactions. Antagonistic interactions, a decrease in toxicity, were observed for mixtures of similar water solubilities.

  5. [Determination of 18 polycyclic aromatic hydrocarbons in plastic products by ultra performance convergence chromatography].

    PubMed

    Dai, Xuewei; Wei, Biwen; Wang Xiuli; Yu, Wenjia; Xu, Yongwei

    2015-10-01

    A method for rapid determination of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo(b) fluoranthene, benzo(k) fluoranthene, benzo(j) fluoranthene, benzo (e) pyrene, benzo (a) pyrene, indeno (1, 2, 3-cd) pyrene, dibenzo (a, h) anthracene, benzo (g, h, i) perylene in plastic products by ultra performance convergence chromatography (UPC2) coupled photodiode array detector (PAD) was developed. The 18 polycyclic aromatic hydrocarbons (PAHs) were successfully separated in less than 8.5 min on a Daicel IB-3 chiral column with a mobile phase of CO2, the mobile-phase additive of methanol/acetonitrile (25 :75, v/v) at column temperature of 40 degrees C, and a back pressure of 15.17 MPa. There was a linear correlation between peak area and PAH concentration in the range of 0.05-50 mg/L (r ≥ 0.999 5) for each PAH. The limits of quantification (LOQs)(S/N > 10) were 0.05 mg/L. After ultrasonic-assisted extraction in toluene, the sample was analyzed by UPC2-PDA. The recoveries of PAHs spiked in plastic samples were from 78.3% to 117.6%, and the repeatabilities of peak areas for the 18 PAHs were less than 5% (RSD, n = 5). The present UPC2-PDA method has the advantages of rapid speed, high resolution, and low organic reagent consumption.

  6. Polycyclic aromatic hydrocarbon reaction rates with peroxy-acid treatment: prediction of reactivity using local ionization potential.

    PubMed

    Shoulder, J M; Alderman, N S; Breneman, C M; Nyman, M C

    2013-08-01

    Property-Encoded Surface Translator (PEST) descriptors were found to be correlated with the degradation rates of polycyclic aromatic hydrocarbons (PAHs) by the peroxy-acid process. Reaction rate constants (k) in hr(-1) for nine PAHs (acenaphthene, anthracene, benzo[a]pyrene, benzo[k]fluoranthene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene) were determined by a peroxy-acid treatment method that utilized acetic acid, hydrogen peroxide, and a sulphuric acid catalyst to degrade the polyaromatic structures. Molecular properties of the selected nine PAHs were derived from structures optimized at B3LYP/6-31G(d) and HF/6-31G(d) levels of theory. Properties of adiabatic and vertical ionization potential (IP), highest occupied molecular orbitals (HOMO), HOMO/lowest unoccupied molecular orbital (LUMO) gap energies and HOMO/singly occupied molecular orbital (SOMO) gap energies were not correlated with rates of peroxy-acid reaction. PEST descriptors were calculated from B3LYP/6-31G(d) optimized structures and found to have significant levels of correlation with k. PIP Min described the minimum local IP on the surface of the molecule and was found to be related to k. PEST technology appears to be an accurate method in predicting reactivity and could prove to be a valuable asset in building treatment models and in remediation design for PAHs and other organic contaminants in the environment. PMID:23734862

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

    PubMed

    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.

  8. Characterizing priority polycyclic aromatic hydrocarbons (PAH) in particulate matter from diesel and palm oil-based biodiesel B15 combustion

    NASA Astrophysics Data System (ADS)

    Rojas, Nestor Y.; Milquez, Harvey Andrés; Sarmiento, Hugo

    2011-11-01

    A set of 16 priority polycyclic aromatic hydrocarbons (PAH) associated with particulate matter (PM), emitted by a diesel engine fueled with petroleum diesel and a 15%-vol. palm oil methyl ester blend with diesel (B15), were determined. PM was filtered from a sample of the exhaust gas with the engine running at a steady speed and under no load. PAH were extracted from the filters using the Soxhlet technique, with dichloromethane as solvent. The extracts were then analyzed by gas chromatography using a flame ionization detector (FID). No significant difference was found between PM mass collected when fueled with diesel and B15. Ten of the 16 PAH concentrations were not reduced by adding biodiesel: Benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, naphthalene and phenanthrene. The acenaphthene, acenaphthylene and anthracene concentrations were 45%-80% higher when using diesel, whereas those for benzo(k)fluoranthene, benzo(g,h,i)perylene and pyrene were 30%-72% higher when using the B15 blend. Even though the 16 priority-PAH cumulative concentration increased when using the B15 blend, the total toxic equivalent (TEQ) concentration was not different for both fuels.

  9. TiO2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

    PubMed

    Kefi, Bochra Bejaoui; El Atrache, Latifa Latrous; Kochkar, Hafedh; Ghorbel, Abdelhamid

    2011-01-01

    An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven polycyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors affecting the extraction efficiency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01-0.8 microg/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017-0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.

  10. Enhancing the intrinsic bioremediation of PAH-contaminated anoxic estuarine sediments with biostimulating agents.

    PubMed

    Bach, Quang-Dung; Kim, Sang-Jin; Choi, Sung-Chan; Oh, Young-Sook

    2005-08-01

    Estuarine sediments are frequently polluted with hydrocarbons from fuel spills and industrial wastes. Polycyclic aromatic hydrocarbons (PAHs) are components of these contaminants that tend to accumulate in the sediment due to their low aqueous solubility, low volatility, and high affinity for particulate matter. The toxic, recalcitrant, mutagenic, and carcinogenic nature of these compounds may require aggressive treatment to remediate polluted sites effectively. In petroleum-contaminated sediments near a petrochemical industry in Gwangyang Bay, Korea, in situ PAH concentrations ranged from 10 to 2,900 microg/kg dry sediment. To enhance the biodegradation rate of PAHs under anaerobic conditions, sediment samples were amended with biostimulating agents alone or in combination: nitrogen and phosphorus in the form of slow-release fertilizer (SRF), lactate, yeast extract (YE), and Tween 80. When added to the sediment individually, all tested agents enhanced the degradation of PAHs, including naphthalene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, and benzo[a]pyrene. Moreover, the combination of SRF, Tween 80, and lactate increased the PAH degradation rate 1.2-8.2 times above that of untreated sediment (0.01-10 microg PAH/kg dry sediment/day). Our results indicated that in situ contaminant PAHs in anoxic sediment, including high molecular weight PAHs, were degraded biologically and that the addition of stimulators increased the biodegradation potential of the intrinsic microbial populations. Our results will contribute to the development of new strategies for in situ treatment of PAH-contaminated anoxic sediments.

  11. Survey of polycyclic aromatic hydrocarbons in marine products in Korea using GC/MS.

    PubMed

    Hwang, Kyungmi; Woo, Sungmin; Choi, Jangduck; Kim, Meehye

    2012-01-01

    This study investigates polycyclic aromatic hydrocarbons (PAHs) in marine products on the Korean market. A total of 280 samples of fish (n = 100), shellfish (n = 80), cephalopod (n = 60) and crustacea (n = 40) were collected for analyses of PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenz[a,h]anthracene and benzo[g,h,i]perylene). The analytical procedure was based on the matrix solid-phase dispersion on Florisil cartridges and extraction with hexane/dichloromethane (3:1, v/v). The PAHs were determined by gas chromatography with mass spectrometric detection using selective ion monitoring. Average recoveries for all the PAHs studied were in the range 58-79%. The sum of 16 PAHs concentrations in fish, shellfish, cephalopod/crustacea were in the range 0.2-0.5, 1.2-1.6 and 0.8-1.9 µg/kg, respectively.

  12. Effect of fuel composition and engine operating conditions on polycyclic aromatic hydrocarbon emissions from a fleet of heavy-duty diesel buses

    NASA Astrophysics Data System (ADS)

    Lim, McKenzie C. H.; Ayoko, Godwin A.; Morawska, Lidia; Ristovski, Zoran D.; Rohan Jayaratne, E.

    Emissions from 12 in-service heavy-duty buses powered by low- (LSD) and ultra low-sulfur (ULSD) diesel fuels were measured with the aim to characterize the profile of polycyclic aromatic hydrocarbons (PAHs) in the exhaust and to identify the effect of different types of fuels on the emissions. To mimic on-road conditions as much as possible, sampling was conducted on a chassis dynamometer at four driving modes, namely: mode 7 or idle (0% power), mode 11 (25% power), mode 10 (50% power) and mode 8 (100% power). Irrespective of the type of fuel used, naphthalene, acenaphthene, acenaphthylene, anthracene, phenanthrene, fluorene, fluoranthene and pyrene were found to be the dominant PAHs in the exhaust emissions of the buses. However, the PAH composition in the exhausts of ULSD buses were up to 91±6% less than those in the LSD buses. In particular, three- and four-ringed PAHs were more abundant in the later than in the former. Lowering of fuel sulfur content not only reduced PAH emission, but also decreased the benzo(a)pyrene equivalent (BAP eq) and hence the toxicity of the exhaust. Result from multicriteria decision-making and multivariate data analysis techniques showed that the use of ULSD afforded cleaner exhaust compositions and emissions with characteristics that are distinct from those obtained by the use of LSD.

  13. Generation and distribution of PAHs in the process of medical waste incineration.

    PubMed

    Chen, Ying; Zhao, Rongzhi; Xue, Jun; Li, Jinhui

    2013-05-01

    After the deadly earthquake on May 12, 2008 in Wenchuan county of China, several different incineration approaches were used for medical waste disposal. This paper investigates the generation properties of polycyclic aromatic hydrocarbons (PAHs) during the incineration. Samples were collected from the bottom ash in an open burning slash site, surface soil at the open burning site, bottom ash from a simple incinerator, bottom ash generated from the municipal solid waste (MSW) incinerator used for medical waste disposal, and bottom ash and fly ash from an incinerator exclusively used for medical waste. The species of PAHs were analyzed, and the toxicity equivalency quantities (TEQs) of samples calculated. Analysis results indicate that the content of total PAHs in fly ash was 1.8×10(3) times higher than that in bottom ash, and that the strongly carcinogenic PAHs with four or more rings accumulated sensitively in fly ash. The test results of samples gathered from open burning site demonstrate that Acenaphthylene (ACY), Acenaphthene (ACE), Fluorene (FLU), Phenanthrene (PHE), Anthracene (ANT) and other PAHs were inclined to migrate into surrounding environment along air and surface watershed corridors, while 4- to 6-ring PAHs accumulated more likely in soil. Being consistent with other studies, it has also been confirmed that increases in both free oxygen molecules and combustion temperatures could promote the decomposition of polycyclic PAHs. In addition, without the influence of combustion conditions, there is a positive correlation between total PCDD/Fs and total PAHs, although no such relationship has been found for TEQ.

  14. PAHs in leachates from thermal power plant wastes and ash-based construction materials.

    PubMed

    Irha, Natalya; Reinik, Janek; Jefimova, Jekaterina; Koroljova, Arina; Raado, Lembi-Merike; Hain, Tiina; Uibu, Mai; Kuusik, Rein

    2015-08-01

    The focus of the current study is to characterise the leaching behaviour of polycyclic aromatic hydrocarbons (PAHs) from oil shale ashes (OSAs) of pulverised firing (PF) and circulating fluidised-bed (CFB) boilers from Estonian Thermal Power Plant (Estonia) as well as from mortars and concrete based on OSAs. The target substances were 16 PAHs from the EPA priority pollutant list. OSA samples and OSA-based mortars were tested for leaching, according to European standard EN 12457-2 (2002). European standard CEN/TC 15862(2012) for monolithic matter was used for OSA-based concrete. Water extracts were analysed by GC-MS for the concentration of PAHs. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene were detected. Still, the release of PAHs was below the threshold limit value for inert waste. The amount of the finest fraction (particle size <0.045 mm), the content of the Al-Si glass phase and the surface characteristics were the main factors, which could affect the accessibility of PAHs for leaching. The mobility of PAHs from OSA of CFB and PF boilers was 20.2 and 9.9%, respectively. Hardening of OSA-based materials did not lead to the immobilisation of soluble PAHs. Release of PAHs from the monolith samples did not exceed 0.5 μg/m(2). In terms of leaching of PAHs, OSA is safe to be used for construction purposes.

  15. Organo/LDH nanocomposite as an adsorbent of polycyclic aromatic hydrocarbons in water and soil-water systems.

    PubMed

    Bruna, F; Celis, R; Real, M; Cornejo, J

    2012-07-30

    Polycyclic aromatic hydrocarbons (PAHs) are considered as priority pollutants because of their high risk to human health. In this paper, we addressed the issue of using hydrotalcite-based nanocomposites as adsorbents of six low molecular weight PAHs (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) to reduce their negative effects on the environment. A nanocomposite (HT-DDS) was prepared by intercalating the organic anion dodecylsulfate (DDS) in a Mg-Al hydrotalcite (HT), and then characterized using several analytical techniques. A Mediterranean soil was selected for being a high-risk scenario of groundwater contamination by leaching of pollutants. The nanocomposite displayed enhanced affinity for the PAHs in water as compared to carbonate-hydrotalcite (HTCO(3)) and its calcined product (HT500), and showed a high irreversibility of the adsorption process (hysteresis coefficient, H<0.15). The results revealed an increase of the pollutants retention in the soil by the addition of the nanocomposite that depended on the nanocomposite application rate and also on the hydrophobicity of each PAH. Accordingly, the use of HT-DDS as an amendment or barrier in contaminated soil is proposed for reducing the mobility of PAHs and, consequently, the adverse effect derived from rapid transport losses of the pollutants to the adjoining environmental compartments.

  16. Ecotoxicological risks associated with land treatment of petrochemical wastes. I. Residual soil contamination and bioaccumulation by cotton rats (Sigmodon hispidus).

    PubMed

    Schroder, Jackie; Basta, Nicholas; Payton, Mark; Wilson, James; Carlson, Ruth; Janz, David; Lochmiller, Robert

    2003-02-28

    Petrochemical waste contains both organic and inorganic contaminants that can pollute soil and may pose significant ecological risks to wildlife. Petrochemical waste typically is disposed of in land treatment units, which are widespread throughout Oklahoma and the United States. Few studies have been conducted evaluating possible toxicity risks to terrestrial organisms residing on these units. In this study, the extent of soil contamination with fluoride (F), metals, and organic hydrocarbons, the bioaccumulation of F and metals in cotton rats (Sigmodon hispidus), the relationship between contaminants in soil and in tissues of cotton rats, and the level of potentially toxic polycyclic aromatic hydrocarbons (PAHs) in soil were determined on land treatment units. Over a 2-yr period, cotton rats and soils were collected and analyzed from 5 land treatment and matched reference units. The number of land treatment units with soil metal contamination (in parentheses) included: Cr, Cu, Pb (5). Al, As, Ni, Sr, Zn (4). Ba (3). and Cd, V (2). The number of land treatment units with soil PAH contamination (in parentheses) were naphthalene, phenanthrene, benzo[g,h,i]perylene (3). acenaphthene, anthracene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenz[a,h]anthracene (2). and acenaphthylene, fluorene, fluoranthene, benzo[k]fluoranthene (1). Total PAH and total petroleum hydrocarbons (TPH) were elevated at all five land treatment units. Mean sums of benzo[a]pyrene (BaP) equivalents (BaPequiv ) were not affected on

  17. Assessment of hydrocarbons concentration in marine fauna due to Tasman Spirit oil spill along the Clifton beach at Karachi coast.

    PubMed

    Siddiqi, Hina A; Ansari, Fayyaz A; Munshi, Alia B

    2009-01-01

    On 27 July 2003, Tasman Spirit spilled 31,000 tonnes of crude oil into the sea at the Karachi coast. This disaster badly affected the marine life (Flora and Fauna.) Present research has been proposed to ascertain the level of Polycyclic Aromatic hydrocarbons (PAHs) contamination in different fisheries including Fishes, Crustaceans; Crabs and Shrimps, Mollusks and Echinoderms along with passing time. Heavier components of crude oil such as Polycyclic Aromatic Hydrocarbons (PAHs) appear to cause most damages as these are relatively unreactive and persist in water. High concentrations of toxic PAHs were observed in all the fisheries and shellfishes caught form oil-impacted area. In this study fishes were found most contaminated than shellfishes i.e. summation operator 16 PAH = 1821.24 microg/g and summation operator 1164.34 microg/g, respectively. Naphthalene was found in the range of 0.042-602.23 microg/g. Acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene were detected in the range 0.008-80.03 microg/g, fluoranthene, pyrene, benzo(a)anthracene and chrysene 0.0008-221.32 microg/g, benzo(b) fluoranthene, benzo(k)fluoranthene and benzo(a) pyrene 0.0005-7.71 microg/g, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene 0.02-503.7 microg/g. Dibenzo(a,h)anthracenre was not detected in any specie. PMID:18302003

  18. Initial environmental impacts of the Obed Mountain coal mine process water spill into the Athabasca River (Alberta, Canada).

    PubMed

    Cooke, Colin A; Schwindt, Colin; Davies, Martin; Donahue, William F; Azim, Ekram

    2016-07-01

    On October 31, 2013, a catastrophic release of approximately 670,000m(3) of coal process water occurred as the result of the failure of the wall of a post-processing settling pond at the Obed Mountain Mine near Hinton, Alberta. A highly turbid plume entered the Athabasca River approximately 20km from the mine, markedly altering the chemical composition of the Athabasca River as it flowed downstream. The released plume traveled approximately 1100km downstream to the Peace-Athabasca Delta in approximately four weeks, and was tracked both visually and using real-time measures of river water turbidity within the Athabasca River. The plume initially contained high concentrations of nutrients (nitrogen and phosphorus), metals, and polycyclic aromatic hydrocarbons (PAHs); some Canadian Council of Ministers of the Environmental (CCME) Guidelines were exceeded in the initial days after the spill. Subsequent characterization of the source material revealed elevated concentrations of both metals (arsenic, lead, mercury, selenium, and zinc) and PAHs (acenaphthene, fluorene, naphthalene, phenanthrene, and pyrene). While toxicity testing using the released material indicated a relatively low or short-lived acute risk to the aquatic environment, some of the water quality and sediment quality variables are known carcinogens and have the potential to exert negative long-term impacts. PMID:27017080

  19. Assessment of hydrocarbons concentration in marine fauna due to Tasman Spirit oil spill along the Clifton beach at Karachi coast.

    PubMed

    Siddiqi, Hina A; Ansari, Fayyaz A; Munshi, Alia B

    2009-01-01

    On 27 July 2003, Tasman Spirit spilled 31,000 tonnes of crude oil into the sea at the Karachi coast. This disaster badly affected the marine life (Flora and Fauna.) Present research has been proposed to ascertain the level of Polycyclic Aromatic hydrocarbons (PAHs) contamination in different fisheries including Fishes, Crustaceans; Crabs and Shrimps, Mollusks and Echinoderms along with passing time. Heavier components of crude oil such as Polycyclic Aromatic Hydrocarbons (PAHs) appear to cause most damages as these are relatively unreactive and persist in water. High concentrations of toxic PAHs were observed in all the fisheries and shellfishes caught form oil-impacted area. In this study fishes were found most contaminated than shellfishes i.e. summation operator 16 PAH = 1821.24 microg/g and summation operator 1164.34 microg/g, respectively. Naphthalene was found in the range of 0.042-602.23 microg/g. Acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene were detected in the range 0.008-80.03 microg/g, fluoranthene, pyrene, benzo(a)anthracene and chrysene 0.0008-221.32 microg/g, benzo(b) fluoranthene, benzo(k)fluoranthene and benzo(a) pyrene 0.0005-7.71 microg/g, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene 0.02-503.7 microg/g. Dibenzo(a,h)anthracenre was not detected in any specie.

  20. Effects of the position and number of bromine substituents on the concentration-mediated 2D self-assembly of phenanthrene derivatives.

    PubMed

    Hu, Xingyu; Zha, Bao; Wu, Yican; Miao, Xinrui; Deng, Wenli

    2016-03-14

    The effects of the position and number of bromine substituents on the self-assembled patterns of phenanthrene derivatives by changing multiple weak intermolecular interactions were investigated at the 1-octanoic acid/graphite interface at different concentrations by scanning tunneling microscopy. Two Br substituted DBHP molecules (2,7-DBHP, 3,6-DBHP) and BHP without a Br group formed a linear lamellar pattern by the van der Waals interactions between the alkoxyl chains in each lamella at high concentrations, which forces the phenanthrene derivatives to self-organize in a π-π stacked edge-on conformation. On decreasing the solution concentration, owing to the molecule-molecule van der Waals force and BrBr halogen bonds or the molecule-solvent cooperative BrO (C[double bond, length as m-dash]O) hydrogen and BrHO-hydrogen bonds, 2,7-DBHP molecules were found to form two kinds of network structures, whereas 3,6-DBHP molecules formed only a zigzag pattern due to the intermolecular BrBr van der Waals type interactions. One bromine substituted phenanthrene derivative (3-DBHP) formed a dislocated linear pattern by two C-HBr hydrogen bonds in each dimer. These observations revealed that an important modification of the position and number of halogen substituents might dramatically change the self-assembly behaviors by different intermolecular interactions including BrBr and BrO halogen bonding, BrBr van der Waals type interactions, and HBr hydrogen bonding. DFT calculations were explored to unravel how slightly tuning the molecular structure defines the geometry of a 2D self-assembled nanoarchitecture through the different elementary structural units having BrBr and BrH interactions. PMID:26890677

  1. The effect of laser wavelength on the Raman Spectra of phenanthrene, chrysene, and tetracene: implications for extra-terrestrial detection of polyaromatic hydrocarbons.

    PubMed

    Alajtal, A I; Edwards, H G M; Elbagerma, M A; Scowen, I J

    2010-06-01

    Raman spectroscopy, with visible laser (514 and 633 nm) and near infrared (785 and 1064 nm) excitation, has been used to obtain high quality spectra of phenanthrene, chrysene, and tetracene. Samples with dimensions from a minimum size of 10 microm have been analyzed utilizing a Raman microprobe fitted with a charge-coupled device (CCD) array detector and a FT-Raman instrument. Fluorescence is observed for samples using visible 514, 633 and near infrared 785 nm excitation but most of the samples can be measured with a near infrared 1064 nm Nd:YAG laser.

  2. The effect of laser wavelength on the Raman Spectra of phenanthrene, chrysene, and tetracene: Implications for extra-terrestrial detection of polyaromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Alajtal, A. I.; Edwards, H. G. M.; Elbagerma, M. A.; Scowen, I. J.

    2010-06-01

    Raman spectroscopy, with visible laser (514 and 633 nm) and near infrared (785 and 1064 nm) excitation, has been used to obtain high quality spectra of phenanthrene, chrysene, and tetracene. Samples with dimensions from a minimum size of 10 μm have been analyzed utilizing a Raman microprobe fitted with a charge-coupled device (CCD) array detector and a FT-Raman instrument. Fluorescence is observed for samples using visible 514, 633 and near infrared 785 nm excitation but most of the samples can be measured with a near infrared 1064 nm Nd:YAG laser.

  3. Facile synthesis of 4,5,6a,7-tetrahydrodibenzo[de,g]chromene heterocycles and their transformation to phenanthrene alkaloids

    PubMed Central

    Kapadia, Nirav; Harding, Wayne

    2013-01-01

    Oxa-Pictet-Spengler cyclization and microwave-assisted C-H arylation have been implemented as key steps in the synthesis of new isochroman heterocycles containing a 4,5,6a,7-tetrahydrodibenzo[de,g]chromene motif. These isochromans may be easily transformed to phenanthrene alkaloids via acidic cleavage of the isochroman ring and standard synthetic manipulations thereafter. The route described is attractive in that it provides access to two biologically interesting scaffolds in simple and high yielding synthetic steps. PMID:24187388

  4. One-pot Zn/CuI/TFA-catalyzed domino three-component-carbocyclization reaction involving biphenyl-2-carbaldehydes/alkynes/piperidine: allenes-mediated construction of phenanthrenes.

    PubMed

    Saifuddin, Mohammad; Agarwal, Piyush K; Kundu, Bijoy

    2011-12-16

    A one-pot protocol involving Zn/CuI/TFA-catalyzed domino three-component and subsequent carbocyclization reactions is described. The reaction proceeds via formation of propargyl amines from biphenyl-2-carbaldehydes/terminal alkynes/piperidine followed by the elimination of piperidine and ring closure to furnish phenanthrene derivatives in good yields. The strategy involves C(sp)-H activation-CH functionalization with imine-alkyne activation-1,5 hydride shift-β-elimination of piperidine-allene formation-6π cycloaddition-isomerization domino sequence. Evidence for the involvement of allenes as an intermediate during carbocyclization is discussed.

  5. BIODEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) FROM CRUDE OIL IN SANDY-BEACH MICROCOSMS.

    EPA Science Inventory

    Though the lower n-alkanes are considered the most degradable components of crude oil, our experiments with microcosms simulating oiled beaches showed substantial depletion of fluorene, phenanthrene, dibenzothiophene, and other PAH in control treatments consisting of raw seawater...

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

    EPA Science Inventory

    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 ...

  7. Preferential Glutathione Conjugation of a Reverse Diol Epoxide Compared to a Bay Region Diol Epoxide of Phenanthrene in Human Hepatocytes: Relevance to Molecular Epidemiology Studies of Glutathione-S-Transferase Polymorphisms and Cancer

    PubMed Central

    Hecht, Stephen S.; Berg, Jeannette Zinggeler; Hochalter, J. Bradley

    2009-01-01

    Bay region diol epoxides are recognized ultimate carcinogens of polycyclic aromatic hydrocarbons (PAH), and in vitro studies have demonstrated that they can be detoxified by conjugation with glutathione, leading to the widely investigated hypothesis that individuals with low activity forms of glutathione-S-transferases are at higher risk of PAH induced cancer, a hypothesis that has found at most weak support in molecular epidemiology studies. A weakness in this hypothesis was that the mercapturic acids resulting from conjugation of PAH bay region diol epoxides had never been identified in human urine. We recently analyzed smokers’ urine for mercapturic acids derived from phenanthrene, the simplest PAH with a bay region. The only phenanthrene diol epoxide-derived mercapturic acid in smokers’ urine was produced from the reverse diol epoxide, anti-phenanthrene-3,4-diol-1,2-epoxide (11), not the bay region diol epoxide, anti-phenanthrene-1,2-diol-3,4-epoxide (10), which does not support the hypothesis noted above. In this study, we extended these results by examining the conjugation of phenanthrene metabolites with glutathione in human hepatocytes. We identified the mercapturic acid N-acetyl-S-(r-4,t-2,3-trihydroxy-1,2,3,4-tetrahydro-c-1-phenanthryl)-L-cysteine (14a), (0.33–35.9 pmol/mL at 10 µM 8, 24h incubation, N = 10) in all incubations with phenanthrene-3,4-diol (8) and the corresponding diol epoxide 11, but no mercapturic acids were detected in incubations with phenanthrene-1,2-diol (7) and only trace amounts were observed in incubations with the corresponding bay region diol epoxide 10. Taken together with our previous results, these studies clearly demonstrate that glutathione conjugation of a reverse diol epoxide of phenanthrene is favored over conjugation of a bay region diol epoxide. Since reverse diol epoxides of PAH are generally weakly or non-mutagenic/carcinogenic, these results, if generalizable to other PAH, do not support the widely held

  8. Anticancer activities of self-assembled molecular bowls containing a phenanthrene-based donor and Ru(II) acceptors

    PubMed Central

    Kim, Inhye; Song, Young Ho; Singh, Nem; Jeong, Yong Joon; Kwon, Jung Eun; Kim, Hyunuk; Cho, Young Mi; Kang, Se Chan; Chi, Ki-Whan

    2015-01-01

    Nano-sized multinuclear ruthenium complexes have rapidly emerged as promising therapeutic candidates with unique anticancer activities. Here, we describe the coordination-driven self-assembly and anticancer activities of a set of three organometallic tetranuclear Ru(II) molecular bowls. [2+2] Coordination-driven self-assembly of 3, 6-bis(pyridin-3- ylethynyl) phenanthrene (bpep) (1) and one of the three dinuclear arene ruthenium clips, [(η6-p-iPrC6H4Me)2Ru2-(OO\\OO)][OTf]2 (OO\\OO =2, 5-dioxido-1, 4-benzoquinonato, OTf = triflate) (2), 5, 8-dioxido-1, 4-naphthoquinonato (3), or 6, 11-dioxido-5, 12-naphthacenediona (4), resulted in three molecular bowls 5–7 of general formula [{(η6-p-iPrC6H4Me)2Ru2-(OO\\OO)}2(bpep)2][OTf]4. All molecular bowls were obtained as triflate salts in very good yields (>90%) and were fully characterized using multinuclear nuclear magnetic resonance (NMR), electrospray ionization–mass spectrometry (ESI-MS), and elemental analysis. The structure of the representative molecular bowl 5 was confirmed by single-crystal X-ray diffraction analysis. The anticancer activities of molecular bowls 5–7 were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide, autophagy, and Western blot analysis. Bowl 6 showed the strongest cytotoxicity in AGS human gastric carcinoma cells and was more cytotoxic than doxorubicin. In addition, autophagic activity and the ratio of apoptotic cell death increased in AGS cells by treatment with bowl 6. Bowl 6 also induced autophagosome formation via upregulation of p62 and promotion of the conversion of LC3-I to LC3-II. Moreover, bowl 6 promoted apoptotic cell death through downregulation of Akt/mTOR activation, followed by increased caspase-3 activity. These results suggest that bowl 6 induces gastric cancer cell death via modulation of autophagy and apoptosis. Bowl 6 is a potent anticancer agent and a potential treatment for human gastric cancer that merits further study. PMID:26347134

  9. Sorption Characteristic of Phenanthrene on Biochar-Amended Soils: Effect of feedstock, pyrolysis temperature, and aging duration

    NASA Astrophysics Data System (ADS)

    Hyun, S.; Kim, C.; Kim, Y. S.; Kim, J.

    2015-12-01

    The high sorption capacity of biochar is widely known in environmental studies. Especially, biochar is effective for removal of hydrophobic organic compounds (HOCs) due to high surface area and porosity. In this study, the sorption characteristic of biochar-amended soil was evaluated by sorption kinetic experiment of phenanthrene (PHE). For PHE sorption test, the effect of biochar feedstock (sludge waste char (SWC), municipal waste char (MWC) and wood char (WC), Giant Miscanthus (GM)), pyrolysis temperature (400°C, 500°C and 700°C,), and duration of amending period (0, 3, 6, and 12 months) was assessed. Field Emission-Scanning Electron Microscopy (FE-SEM) and Fourier Transform-Infrared Spectroscopy (FT-IR) techniques were used to detect pore structure and the surface functional group of biochar amended soils. For all kinetic tests, apparent sorption equilibrium was attained in 24 hr. The result showed that sorption capacity of biochar amended soils was greatly influenced by biochar feedstock and pyrolysis temperature. For all samples, the sorption capacity of PHE by biochar amended soils decreased with aging period. This observation is due to the fact that the aromatic characters of biochar are different by feedstock and pyrolysis temperature and the amount of O-containing hydrophilic functional groups increased surfaces of biochar by natural oxidation (e.g. carboxyl groups) as confirmed by the result of FT-IR and FE-SEM. In addition, biochar pore blockage by inorganic minerals, which tended to increase with aging period, might attenuate the sorption capacity of samples. In conclusion, biochar derived from various feed stocks are all effective for PHE sorption. But the sorption capacity of biochar amended soils decreased with increasing aging duration most likely due to increasing hydrophilic functional groups of biochar surfaces and pore blockage by inorganic minerals in the weathering processes. Therefore, for the design of biochar amendment to attenuate

  10. Evaluation of a rat model versus a physiologically based extraction test for assessing phenanthrene bioavailability from soils.

    PubMed

    Pu, Xinzhu; Lee, Linda S; Galinsky, Raymond E; Carlson, Gary P

    2004-05-01

    The soil matrix can impact the bioavailability of soil-bound organic chemicals, and this impact is governed in part by soil properties such as organic carbon (OC) content, clay minerals, and pH. Recently, a physiologically based extraction test (PBET) was developed to predict the bioavailability of soil-bound organic chemicals. In the current study, the bioavailability of phenanthrene (PA) from laboratory-treated soils varying in OC content, clay, and pH was investigated using an in vivo rat model and an in vitro PBET. The relationship between these two approaches was also examined. In the in vivo assay, soils and corn oil containing equivalent levels of PA were administered to Sprague-Dawley rats by gavage at two dose levels: 400 and 800 mg/kg body weight. Equivalent doses were given via intravenous injection (i.v.). The areas under the blood concentration-versus-time curves (AUC) were measured, and the absolute and relative bioavailabilities of PA were determined for each soil. In the PBET tests, one g of each soil was extracted by artificial saliva, gastric juice, duodenum juice, and bile. The fraction of PA mobilized from each soil was quantified. The AUCs of PA in all soils were significantly lower than those following iv injection (p < 0.05), indicating that the soil matrix could reduce the bioavailability of PA from soil. There were obvious trends of soils with higher OC content and clay content, resulting in the lower bioavailability of PA from soil. A significant correlation (p < 0.05) was observed between the fraction of PA mobilized from soil in the PBET and its in vivo bioavailability. The data also showed that the absolute bioavailability of PA from corn oil was low: approximately 25%. These results suggest that PBET assay might be a useful alternative in predicting bioavailability of soil-bound organic chemicals. However, due to the limited soil types and use of one chemical vs. a variety of contaminants and soil properties in the environment, further

  11. Histological responses and localization of the cytochrome P450 (CYP2AU1) in Crassostrea brasiliana exposed to phenanthrene.

    PubMed

    dos Reis, Isis M M; Mattos, Jacó J; Garcez, Ricardo C; Zacchi, Flávia L; Miguelão, Talita; Flores-Nunes, Fabrício; Toledo-Silva, Guilherme; Sasaki, Sílvio T; Taniguchi, Satie; Bícego, Márcia C; Cargnin-Ferreira, Eduardo; Bainy, Afonso C D

    2015-12-01

    Phenanthrene (PHE) is an abundant polycyclic aromatic hydrocarbon (PAH), widely distributed in aquatic environment. The aim of this study was to evaluate the histological and molecular effects in the native oyster Crassostrea brasiliana(Lamarck, 1819) exposed to 100 and 1000 μg L(-1) PHE for 1, 5 and 10 days. Histological and chemical analyses were performed to evaluate, respectively, alterations in oyster tissues and bioaccumulation. In situ hybridization (ISH) was used to assess tissue distribution of CYP2AU1, a gene formerly identified as activated by PHE exposure in this species.Quantitative polymerase chain reaction (qPCR) in mantle was carried out to validate ISH data. Oysters bioaccumulated PHE increasingly along the exposure period in both exposure concentrations. Histologic changes, like tubular atrophy in digestive diverticula (digestive gland) and increased number of mucous cells in the mantle were observed in animals exposed to PHE for 10 days. ISH showed the presence of CYP2AU1transcripts in gills, digestive diverticula, mantle, intestine and gonads, but significant differences in transcript detection by ISH between treatments occurred only in gills, mantle and intestine. A positive and significant correlation between tubular atrophy and CYP2AU1hybridization signal was observed in digestive diverticula, suggesting that this gene product might be involved in energetic metabolism in C. brasiliana. Increased mucous cells and CYP2AU1transcript levels were observed in the mantle, where the inner and middle lobes showed higher intensity of hybridization signal. Mantle should be considered as a target organ for CYP2AU1 transcript evaluation and histological alterations in biomonitoring studies. CYP2AU1 signal in female gonads was observed in all follicular cells from different gonadic stages, while in male only the spermatic follicle cells of the wall in the pre-spawning stage showed this signal. ISH was an effective technique to evaluate the effects of PHE

  12. Anticancer activities of self-assembled molecular bowls containing a phenanthrene-based donor and Ru(II) acceptors.

    PubMed

    Kim, Inhye; Song, Young Ho; Singh, Nem; Jeong, Yong Joon; Kwon, Jung Eun; Kim, Hyunuk; Cho, Young Mi; Kang, Se Chan; Chi, Ki-Whan

    2015-01-01

    Nano-sized multinuclear ruthenium complexes have rapidly emerged as promising therapeutic candidates with unique anticancer activities. Here, we describe the coordination-driven self-assembly and anticancer activities of a set of three organometallic tetranuclear Ru(II) molecular bowls. [2+2] Coordination-driven self-assembly of 3, 6-bis(pyridin-3- ylethynyl) phenanthrene (bpep) (1) and one of the three dinuclear arene ruthenium clips, [(η6-p-iPrC6H4Me)2Ru2-(OO\\OO)][OTf]2 (OO\\OO =2, 5-dioxido-1, 4-benzoquinonato, OTf = triflate) (2), 5, 8-dioxido-1, 4-naphthoquinonato (3), or 6, 11-dioxido-5, 12-naphthacenediona (4), resulted in three molecular bowls 5-7 of general formula [{(η6-p-iPrC6H4Me)2Ru2-(OO\\OO)}2(bpep)2][OTf]4. All molecular bowls were obtained as triflate salts in very good yields (>90%) and were fully characterized using multinuclear nuclear magnetic resonance (NMR), electrospray ionization-mass spectrometry (ESI-MS), and elemental analysis. The structure of the representative molecular bowl 5 was confirmed by single-crystal X-ray diffraction analysis. The anticancer activities of molecular bowls 5-7 were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide, autophagy, and Western blot analysis. Bowl 6 showed the strongest cytotoxicity in AGS human gastric carcinoma cells and was more cytotoxic than doxorubicin. In addition, autophagic activity and the ratio of apoptotic cell death increased in AGS cells by treatment with bowl 6. Bowl 6 also induced autophagosome formation via upregulation of p62 and promotion of the conversion of LC3-I to LC3-II. Moreover, bowl 6 promoted apoptotic cell death through downregulation of Akt/mTOR activation, followed by increased caspase-3 activity. These results suggest that bowl 6 induces gastric cancer cell death via modulation of autophagy and apoptosis. Bowl 6 is a potent anticancer agent and a potential treatment for human gastric cancer that merits further study. PMID:26347134

  13. Histological responses and localization of the cytochrome P450 (CYP2AU1) in Crassostrea brasiliana exposed to phenanthrene.

    PubMed

    dos Reis, Isis M M; Mattos, Jacó J; Garcez, Ricardo C; Zacchi, Flávia L; Miguelão, Talita; Flores-Nunes, Fabrício; Toledo-Silva, Guilherme; Sasaki, Sílvio T; Taniguchi, Satie; Bícego, Márcia C; Cargnin-Ferreira, Eduardo; Bainy, Afonso C D

    2015-12-01

    Phenanthrene (PHE) is an abundant polycyclic aromatic hydrocarbon (PAH), widely distributed in aquatic environment. The aim of this study was to evaluate the histological and molecular effects in the native oyster Crassostrea brasiliana(Lamarck, 1819) exposed to 100 and 1000 μg L(-1) PHE for 1, 5 and 10 days. Histological and chemical analyses were performed to evaluate, respectively, alterations in oyster tissues and bioaccumulation. In situ hybridization (ISH) was used to assess tissue distribution of CYP2AU1, a gene formerly identified as activated by PHE exposure in this species.Quantitative polymerase chain reaction (qPCR) in mantle was carried out to validate ISH data. Oysters bioaccumulated PHE increasingly along the exposure period in both exposure concentrations. Histologic changes, like tubular atrophy in digestive diverticula (digestive gland) and increased number of mucous cells in the mantle were observed in animals exposed to PHE for 10 days. ISH showed the presence of CYP2AU1transcripts in gills, digestive diverticula, mantle, intestine and gonads, but significant differences in transcript detection by ISH between treatments occurred only in gills, mantle and intestine. A positive and significant correlation between tubular atrophy and CYP2AU1hybridization signal was observed in digestive diverticula, suggesting that this gene product might be involved in energetic metabolism in C. brasiliana. Increased mucous cells and CYP2AU1transcript levels were observed in the mantle, where the inner and middle lobes showed higher intensity of hybridization signal. Mantle should be considered as a target organ for CYP2AU1 transcript evaluation and histological alterations in biomonitoring studies. CYP2AU1 signal in female gonads was observed in all follicular cells from different gonadic stages, while in male only the spermatic follicle cells of the wall in the pre-spawning stage showed this signal. ISH was an effective technique to evaluate the effects of PHE

  14. Benchmark theoretical study of the ionization energies, electron affinities and singlet-triplet energy gaps of azulene, phenanthrene, pyrene, chrysene and perylene

    NASA Astrophysics Data System (ADS)

    Huzak, M.; Hajgató, B.; Deleuze, M. S.

    2012-10-01

    The vertical and adiabatic singlet-triplet energy gaps, electron affinities and ionization energies of azulene, phenanthrene, pyrene, chrysene, and perylene are computed by applying the principles of a focal point analysis onto a series of single-point calculations at the level of Hartree-Fock theory, second-, third-, and fourth-order Møller-Plesset perturbation theory, as well as coupled cluster theory including single, double and perturbative triple excitations, in conjunction with correlation consistent basis sets of improving quality. Results are supplemented with an extrapolation to the limit of an asymptotically complete basis set. According to our best estimates, azulene, phenanthrene, pyrene, chrysene, and perylene exhibit adiabatic singlet-triplet energy gaps of 1.79, 2.92, 2.22, 2.79 and 1.71 eV, respectively. In the same order, the corresponding adiabatic electron affinities (EAs) amount to 0.71, -0.08, -0.40, 0.24, and 0.87 eV, whereas benchmark values equal to 7.43, 8.01, 7.48, 7.66 and 7.15 eV, are found for the adiabatic ionization energies.

  15. A new phenanthrene derivative and two diarylheptanoids from the roots of Brassica rapa ssp. campestris inhibit the growth of cancer cell lines and LDL-oxidation.

    PubMed

    Wu, Qian; Cho, Jin-Gyeong; Yoo, Ki-Hyun; Jeong, Tae-Sook; Park, Ji-Hae; Kim, Su-Yeon; Kang, Ji-Hyun; Chung, In-Sik; Choi, Myung-Sook; Lee, Kyung-Tae; Chung, Hae-Gon; Bang, Myun-Ho; Baek, Nam-In

    2013-04-01

    Brassica rapa ssp. campestris (Brassicaceae) is a conical, deep purple, edible root vegetable commonly known as a turnip. We initiated phytochemical and pharmacological studies to search for biological active compounds from the roots of B. rapa ssp. campestris. We isolated a novel phenanthrene derivative, 6-methoxy-1-[10-methoxy-7-(3-methylbut-2-enyl)phenanthren-3-yl]undecane-2,4-dione, named brassicaphenanthrene A (3) along with two known diarylheptanoid compounds, 6-paradol (1) and trans-6-shogaol (2), through the repeated silica gel (SiO2), octadecyl silica gel, and Sephadex LH-20 column chromatography. The chemical structures of the compounds were determined by spectroscopic data analyses including nuclear magnetic resonance, mass spectrometry, ultraviolet spectroscopy, and infra-red spectroscopy. All compounds exhibited high inhibitory activity against the growth of human cancer lines, HCT-116, MCF-7, and HeLa, with IC50 values ranging from 15.0 to 35.0 μM and against LDL-oxidation with IC50 values ranging from 2.9 to 7.1 μM.

  16. X-ray structural studies and molecular orbital calculations (CNDO/2) in a series of cyclopenta[a]phenanthrenes: attempts at correlation with carcinogenicity.

    PubMed

    Clayton, A F; Coombs, M M; Henrick, K; McPartlin, M; Trotter, J

    1983-12-01

    Comparative X-ray crystallographic structure analyses have been carried out on seven cyclopenta[a]phenanthrenes, namely 15,16-dihydocyclopenta[a]phenanthren-17-one and its 2-, 6- and 12-methyl homologues (non-carcinogens) and the 7-and 11-methyl and 1,11-methano derivatives (carcinogens). All-valence-electron molecular-orbital calculations by the CNDO/2 method, using the crystallographic parameters, have also been executed. Charge distribution and the energies of the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) have been calculated. With one exception all the molecules show only small deviations from planarity, the exception being the strongly carcinogenic 11-methyl-17-ketone in which the bay-region methyl group causes out-of-plane deformation of the benzo rings of 12.5 degrees. Among the other six compounds the two carcinogens are readily differentiated by high angle strain induced by a 7-methyl group or a 1,11-methano bridge. As expected, the HOMO's of these molecules to some extent reflect their ease of chemical oxidation at the 6,7-double bond; biological oxidation is less easy to correlate probably due to spatial restrictions at the active site within the mono-oxygenase.

  17. Soil pollution by PAHs in urban soils: a comparison of three European cities.

    PubMed

    Morillo, E; Romero, A S; Maqueda, C; Madrid, L; Ajmone-Marsan, F; Grcman, H; Davidson, C M; Hursthouse, A S; Villaverde, J

    2007-09-01

    The purpose of this study was to determine the degree of contamination with polycyclic aromatic hydrocarbons (PAHs) in samples of urban soil from three European cities: Glasgow (UK), Torino (Italy) and Ljubljana (Slovenia). Fifteen PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) were measured in urban soil samples, using harmonised sampling, sample extraction and analyte quantification methods. Although the mean concentration of each PAH in urban soils of each city showed a wide range of values, high levels of contamination were only evident in Glasgow, where the sum of concentrations of 15 PAHs was in the range 1487-51,822 microg kg(-1), cf. ranges in the other two cities were about ten-fold lower (89.5-4488 microg kg(-1)). The three predominant PAHs were phenanthrene, fluoranthene and pyrene, with the sum of these compounds about 40% of the total PAH content. These data, together with some special molecular indices based on ratios of selected PAHs, suggest pyrogenic origins, especially motor vehicle exhausts, to be the major sources of PAHs in urban soils of the three cities. The largest concentrations for PAHs were often found in sites close to the historic quarters of the cities. Overall, the different climatic conditions, the organic carbon contents of soil, and the source apportionment were the dominant factors affecting accumulation of PAHs in soil. PMID:17726562

  18. Multivariate analysis of mixed contaminants (PAHs and heavy metals) at manufactured gas plant site soils.

    PubMed

    Thavamani, Palanisami; Megharaj, Mallavarapu; Naidu, Ravi

    2012-06-01

    Principal component analysis (PCA) was used to provide an overview of the distribution pattern of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in former manufactured gas plant (MGP) site soils. PCA is the powerful multivariate method to identify the patterns in data and expressing their similarities and differences. Ten PAHs (naphthalene, acenapthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo[a]pyrene) and four toxic heavy metals - lead (Pb), cadmium (Cd), chromium (Cr) and zinc (Zn) - were detected in the site soils. PAH contamination was contributed equally by both low and high molecular weight PAHs. PCA was performed using the varimax rotation method in SPSS, 17.0. Two principal components accounting for 91.7% of the total variance was retained using scree test. Principle component 1 (PC1) substantially explained the dominance of PAH contamination in the MGP site soils. All PAHs, except anthracene, were positively correlated in PC1. There was a common thread in high molecular weight PAHs loadings, where the loadings were inversely proportional to the hydrophobicity and molecular weight of individual PAHs. Anthracene, which was less correlated with other individual PAHs, deviated well from the origin which can be ascribed to its lower toxicity and different origin than its isomer phenanthrene. Among the four major heavy metals studied in MGP sites, Pb, Cd and Cr were negatively correlated in PC1 but showed strong positive correlation in principle component 2 (PC2). Although metals may not have originated directly from gaswork processes, the correlation between PAHs and metals suggests that the materials used in these sites may have contributed to high concentrations of Pb, Cd, Cr and Zn. Thus, multivariate analysis helped to identify the sources of PAHs, heavy metals and their association in MGP site, and thereby better characterise the site risk, which would not be possible if one uses chemical analysis

  19. Soil type-dependent responses to phenanthrene as revealed by determining the diversity and abundance of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase genes by using a novel PCR detection system.

    PubMed

    Ding, Guo-Chun; Heuer, Holger; Zühlke, Sebastian; Spiteller, Michael; Pronk, Geertje Johanna; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2010-07-01

    A novel PCR primer system that targets a wide range of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD(alpha)) genes of both Gram-positive and Gram-negative bacteria was developed and used to study their abundance and diversity in two different soils in response to phenanthrene spiking. The specificities and target ranges of the primers predicted in silico were confirmed experimentally by cloning and sequencing of PAH-RHD(alpha) gene amplicons from soil DNA. Cloning and sequencing showed the dominance of phnAc genes in the contaminated Luvisol. In contrast, high diversity of PAH-RHD(alpha) genes of Gram-positive and Gram-negative bacteria was observed in the phenanthrene-spiked Cambisol. Quantitative real-time PCR based on the same primers revealed that 63 days after phenanthrene spiking, PAH-RHD(alpha) genes were 1 order of magnitude more abundant in the Luvisol than in the Cambisol, while they were not detected in both control soils. In conclusion, sequence analysis of the amplicons obtained confirmed the specificity of the novel primer system and revealed a soil type-dependent response of PAH-RHD(alpha) gene-carrying soil bacteria to phenanthrene spiking.

  20. Metabolites of the Polycyclic Aromatic Hydrocarbon Phenanthrene in the Urine of Cigarette Smokers from Five Ethnic Groups with Differing Risks for Lung Cancer.

    PubMed

    Patel, Yesha M; Park, Sungshim L; Carmella, Steven G; Paiano, Viviana; Olvera, Natalie; Stram, Daniel O; Haiman, Christopher A; Le Marchand, Loic; Hecht, Stephen S

    2016-01-01

    Results from the Multiethnic Cohort Study demonstrated significant differences in lung cancer risk among cigarette smokers from five different ethnic/racial groups. For the same number of cigarettes smoked, and particularly among light smokers, African Americans and Native Hawaiians had the highest risk for lung cancer, Whites had intermediate risk, while Latinos and Japanese Americans had the lowest risk. We analyzed urine samples from 331-709 participants from each ethnic group in this study for metabolites of phenanthrene, a surrogate for carcinogenic polycyclic aromatic hydrocarbon exposure. Consistent with their lung cancer risk and our previous studies of several other carcinogens and toxicants of cigarette smoke, African Americans had significantly (p<0.0001) higher median levels of the two phenanthrene metabolites 3-hydroxyphenanthrene (3-PheOH, 0.931 pmol/ml) and phenanthrene tetraol (PheT, 1.13 pmol/ml) than Whites (3-PheOH, 0.697 pmol/ml; PheT, 0.853 pmol/ml) while Japanese-Americans had significantly (p = 0.002) lower levels of 3-PheOH (0.621 pmol/ml) than Whites. PheT levels (0.838 pmol/ml) in Japanese-Americans were not different from those of Whites. These results are mainly consistent with the lung cancer risk of these three groups, but the results for Native Hawaiians and Latinos were more complex. We also carried out a genome wide association study in search of factors that could influence PheT and 3-PheOH levels. Deletion of GSTT1 explained 2.2% of the variability in PheT, while the strongest association, rs5751777 (p = 1.8x10-62) in the GSTT2 gene, explained 7.7% of the variability in PheT. These GWAS results suggested a possible protective effect of lower GSTT1 copy number variants on the diol epoxide pathway, which was an unexpected result. Collectively, the results of this study provide further evidence that different patterns of cigarette smoking are responsible for the higher lung cancer risk of African Americans than of Whites and the

  1. Metabolites of the Polycyclic Aromatic Hydrocarbon Phenanthrene in the Urine of Cigarette Smokers from Five Ethnic Groups with Differing Risks for Lung Cancer

    PubMed Central

    Patel, Yesha M.; Park, Sungshim L.; Carmella, Steven G.; Paiano, Viviana; Olvera, Natalie; Stram, Daniel O.; Haiman, Christopher A.; Le Marchand, Loic

    2016-01-01

    Results from the Multiethnic Cohort Study demonstrated significant differences in lung cancer risk among cigarette smokers from five different ethnic/racial groups. For the same number of cigarettes smoked, and particularly among light smokers, African Americans and Native Hawaiians had the highest risk for lung cancer, Whites had intermediate risk, while Latinos and Japanese Americans had the lowest risk. We analyzed urine samples from 331–709 participants from each ethnic group in this study for metabolites of phenanthrene, a surrogate for carcinogenic polycyclic aromatic hydrocarbon exposure. Consistent with their lung cancer risk and our previous studies of several other carcinogens and toxicants of cigarette smoke, African Americans had significantly (p<0.0001) higher median levels of the two phenanthrene metabolites 3-hydroxyphenanthrene (3-PheOH, 0.931 pmol/ml) and phenanthrene tetraol (PheT, 1.13 pmol/ml) than Whites (3-PheOH, 0.697 pmol/ml; PheT, 0.853 pmol/ml) while Japanese-Americans had significantly (p = 0.002) lower levels of 3-PheOH (0.621 pmol/ml) than Whites. PheT levels (0.838 pmol/ml) in Japanese-Americans were not different from those of Whites. These results are mainly consistent with the lung cancer risk of these three groups, but the results for Native Hawaiians and Latinos were more complex. We also carried out a genome wide association study in search of factors that could influence PheT and 3-PheOH levels. Deletion of GSTT1 explained 2.2% of the variability in PheT, while the strongest association, rs5751777 (p = 1.8x10-62) in the GSTT2 gene, explained 7.7% of the variability in PheT. These GWAS results suggested a possible protective effect of lower GSTT1 copy number variants on the diol epoxide pathway, which was an unexpected result. Collectively, the results of this study provide further evidence that different patterns of cigarette smoking are responsible for the higher lung cancer risk of African Americans than of Whites and the

  2. Evaluation of ultraviolet spectrophotometry for simultaneous analysis of alkylbenzenes, alkylnaphthalenes, alkylanthracenes/phenanthrenes and total aromatics in mid-distillate fuels

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Seng, G. T.

    1982-01-01

    A rapid ultraviolet spectrophotometric method for the simultaneous determination of aromatics in middistillate fuels was developed and evaluated. In this method, alkylbenzenes, alkylnaphthalenes, alkylanthracenes/phenanthracenes and total aromatics were determined from ultraviolet spectra of the fuels. The accuracy and precision were determined using simulated standard fuels with known compositions. The total aromatics fraction accuracy was 5% for a Jet A type fuel and 0.6% for a broadened properties jet turbine type fuel. Precision, expressed as relative standard deviations, ranged from 2.9% for the alkylanthracenes/phenanthrenes to 15.3% for the alkylbenzenes. The accuracy, however, was less for actual fuel samples when compared to the results obtained by a mass spectrometric method. In addition, the ASTM D-1840 method for naphthalenes by ultraviolet spectroscopy was evaluated.

  3. Structural insight into DNA-assembled oligochromophores: crystallographic analysis of pyrene- and phenanthrene-modified DNA in complex with BpuJI endonuclease

    PubMed Central

    Probst, Markus; Aeschimann, Walter; Chau, Thi T.H.; Langenegger, Simon M.; Stocker, Achim; Häner, Robert

    2016-01-01

    The use of the DNA duplex as a supramolecular scaffold is an established approach for the assembly of chromophore aggregates. In the absence of detailed structural insight, the characterization of thus assembled oligochromophores is, today, largely based on solution-phase spectroscopy. Here, we describe the crystal structures of three DNA-organized chromophore aggregates. DNA hybrids containing non-nucleosidic pyrene and phenanthrene building blocks were co-crystallized with the recently described binding domain of the restriction enzyme BpuJI. Crystal structures of these complexes were determined at 2.7, 1.9 and 1.6 Å resolutions. The structures reveal aromatic stacking interactions between pyrene and/or phenanthrene units within the framework of the B-DNA duplex. In hybrids containing a single modification in each DNA strand near the end of the duplex, the two polyaromatic hydrocarbons are engaged in a face-to-face stacking orientation. Due to crystal packing and steric effects, the terminal GC base pair is disrupted in all three crystal structures, which results in a non-perfect stacking arrangement of the aromatic chromophores in two of the structures. In a hybrid containing a total of three pyrenes, crystal lattice induced end-to-end stacking of individual DNA duplexes leads to the formation of an extended aromatic π-stack containing four co-axially arranged pyrenes. The aromatic planes of the stacked pyrenes are oriented in a parallel way. The study demonstrates the value of co-crystallization of chemically modified DNA with the recombinant binding domain of the restriction enzyme BpuJI for obtaining detailed structural insight into DNA-assembled oligochromophores. PMID:27422870

  4. Crystal structure of 2,2''-bis-(2,7-di-chloro-9-hy-droxy-9H-fluoren-9-yl)-1,1':4',1''-terphenyl tri-ethyl-amine trisolvate.

    PubMed

    Klien, Henrik; Seichter, Wilhelm; Weber, Edwin

    2015-12-01

    In the title solvate, C44H26Cl4O2·3C6H15N, the asymmetric part of the unit cell comprises two halves of the diol mol-ecules, 2,2''-bis-(2,7-di-chloro-9-hy-droxy-9H-fluoren-9-yl)-1,1':4',1''-terphenyl, and three mol-ecules of tri-ethyl-amine, i. e. the diol mol-ecules are located on crystallographic symmetry centres. Two of the solvent mol-ecules are disordered over two positions [occupancy ratios of 0.567 (3):0.433 (3) and 0.503 (3):0.497 (3)]. In the diol mol-ecules, the outer rings of the 1,1':4',1''-terphenyl elements are twisted with reference to their central arene ring and the mean planes of the fluorenyl moieties are inclined with respect to the terphenyl ring to which they are connected, the latter making dihedral angles of 82.05 (8) and 82.28 (8)°. The presence of two 9-fluoren-9-ol units attached at positions 2 and 2'' of the terphenyl moiety induces a 'folded' geometry which is stabilized by intra-molecular C-H⋯O hydrogen bonds and π-π stacking inter-actions, the latter formed between the fluorenyl units and the central ring of the terphenyl unit [centroid-centroid distances = 3.559 (1) and 3.562 (1) Å]. The crystal is composed of 1:2 complex units, in which the solvent mol-ecules are associated with the diol mol-ecules via O-H⋯N hydrogen bonds, while the remaining solvent mol-ecule is linked to the host by a C-H⋯N hydrogen bond. The given pattern of inter-molecular inter-actions results in formation of chain structures extending along [010]. PMID:26870400

  5. Star-Shaped Macromolecules with the Core of Hexakis-(fluoren-2-yl)benzene and the Periphery of Pyridine: Synthesis and Application as Solution-Processable Electron-Transport Materials.

    PubMed

    Yin, Xiaojun; Miao, Jingsheng; Xiang, Yepeng; Wu, Hongbing; Cao, Yong; Yang, Chuluo

    2015-09-01

    Three new star-shaped macromolecules with hexakis(fluoren-2-yl)benzene as the core and pyridine as the periphery (2Py-HFB, 3Py-HFB, and 4Py-HFB) are synthesized and characterized. The synthetic conditions of octacarbonyldicobat-catalyzed cycloaddition reaction for different alkyne precursors are investigated. The coordination interaction between the pyridine ring of alkyne precursor and the cobalt catalyst may result in very low yield of the cyclotrimerization product. However, with the increase of the catalyst loading, the yields of the intermediates of cyclopentadienone are enhanced. Then, the desired cyclotrimerization products can be obtained by the Diels-Alder reactions of cyclopentadienone with acetylene in good yield. These new compounds exhibit good thermal stability and favorable electron affinity. By using the new compounds as electron-transporting materials, all-solution-processed phosphorescent organic light-emitting devices (OLEDs) show good performance with a maximum current efficiency of 5.6 cd A(-1) and maximum external quantum efficiency of 4.68%.

  6. Functional Categorization of Transcriptome in the Species Symphysodon aequifasciatus Pellegrin 1904 (Perciformes: Cichlidae) Exposed to Benzo[a]pyrene and Phenanthrene

    PubMed Central

    Lemgruber, Renato de Souza Pinto; Marshall, Nislanha Ana dos Anjos; Ghelfi, Andrea; Fagundes, Daniel Barros; Val, Adalberto Luis

    2013-01-01

    This study aims to evaluate the transcriptome alterations, through cDNA libraries, associated with the combined effects of two PAHs, benzo[a]pyrene (0.5 µg/L) and phenanthrene (50 µg/L), present in crude oil, on specimens of Symphysodon aequifasciatus (discus fish) after 48 h of exposure. The cDNA libraries were constructed according to the SOLiD™ SAGE™ protocol for sequencing in the SOLiD v.3 Plus sequencer. The results were analyzed by bioinformatics and differentially expressed genes were categorized using the gene ontology program. The functional categories (terms) found in the gene ontology and the gene network generated using STRING software were used to predict the adverse effects of benzo[a]pyrene and phenanthrene in the liver. In the present study, 27,127 genes (compared to Danio rerio database) were identified. Considering only those genes with a p-value less than or equal to 0.05 and greater than or equal to two-fold change in expression across libraries, we found 804 genes, 438 down-regulated (54%) and 366 up-regulated (46%), in the experimental group compared to the control. Out of this total, 327 genes were successfully categorized, 174 down-regulated and 153 up-regulated, using gene ontology. Using String, the gene network was composed by 199 nodes, 124 of them resulting in 274 interactions. The results showed that even an acute exposure of 48 h caused metabolic change in response to environmental contaminants, resulting in changes of cell integrity, in oxidation-reduction processes, in the immune response and disturbances of intracellular signaling of discus fish. Also the gene network has showed no central interplay cluster, exhibiting instead interconnected clusters interactions and connected sub-networks. These findings highlight that even an acute sublethal exposure of PAHs can cause metabolism changes that may affect survival of discus. Our findings using SOLiD coupled with SAGE-method resulted in a powerful and reliable means for gene

  7. Adsorption of phenanthrene, 2-naphthol, and 1-naphthylamine to colloidal oxidized multiwalled carbon nanotubes: effects of humic acid and surfactant modification.

    PubMed

    Hou, Lei; Zhu, Dongqiang; Wang, Ximeng; Wang, Lilin; Zhang, Chengdong; Chen, Wei

    2013-03-01

    Carbon nanotubes (CNTs) can exist in the form of colloidal suspension in aquatic environments, particularly in the presence of natural organic matter or surfactants, and may significantly affect the fate and transport of organic contaminants. In the present study, the authors examined the adsorption of phenanthrene, 2-naphthol, and 1-naphthylamine to three colloidal CNTs, including a stable suspension of oxidized multiwalled carbon nanotubes (O-MWNT), a humic acid (HA)-modified colloidal O-MWNT, and a sodium dodecyl sulfate (SDS)-modified colloidal O-MWNT. All three colloidal O-MWNTs exhibit strong adsorption affinities to the three test compounds (with K(OC) values orders of magnitude greater than those of natural organic matter), likely resulting from strong nonhydrophobic interactions such as π-π electron donor-acceptor interactions and Lewis acid-base interactions. When thoroughly mixed, HA (at ∼310 mg HA/g CNT) and SDS (at ∼750 mg SDS/g CNT) significantly affected the aggregation properties of O-MWNT, causing individually dispersed tubes to form a loosely entangled network. The effects of HA or SDS modification on adsorption are twofold. Adsorption of HA/SDS significantly reduces surface areas of O-MWNT; however, the entangled network allows adsorbate molecules to interact simultaneously with multiple tubes. An important implication is that humic substances and surfactant-like materials not only facilitate the formation of colloidal carbon nanoparticles but also affect how these colloidal carbon nanoparticles adsorb organic contaminants.

  8. The anharmonic quartic force field infrared spectra of five non-linear polycyclic aromatic hydrocarbons: Benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    The study of interstellar polycyclic aromatic hydrocarbons (PAHs) relies heavily on theoretically predicted infrared spectra. Most earlier studies use scaled harmonic frequencies for band positions and the double harmonic approximation for intensities. However, recent high-resolution gas-phase experimental spectroscopic studies have shown that the harmonic approximation is not sufficient to reproduce experimental results. In our previous work, we presented the anharmonic theoretical spectra of three linear PAHs, showing the importance of including anharmonicities into the theoretical calculations. In this paper, we continue this work by extending the study to include five non-linear PAHs (benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene), thereby allowing us to make a full assessment of how edge structure, symmetry, and size influence the effects of anharmonicities. The theoretical anharmonic spectra are compared to spectra obtained under matrix isolation low-temperature conditions, low-resolution, high-temperature gas-phase conditions, and high-resolution, low-temperature gas-phase conditions. Overall, excellent agreement is observed between the theoretical and experimental spectra although the experimental spectra show subtle but significant differences.

  9. The anharmonic quartic force field infrared spectra of five non-linear polycyclic aromatic hydrocarbons: Benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene.

    PubMed

    Mackie, Cameron J; Candian, Alessandra; Huang, Xinchuan; Maltseva, Elena; Petrignani, Annemieke; Oomens, Jos; Mattioda, Andrew L; Buma, Wybren Jan; Lee, Timothy J; Tielens, Alexander G G M

    2016-08-28

    The study of interstellar polycyclic aromatic hydrocarbons (PAHs) relies heavily on theoretically predicted infrared spectra. Most earlier studies use scaled harmonic frequencies for band positions and the double harmonic approximation for intensities. However, recent high-resolution gas-phase experimental spectroscopic studies have shown that the harmonic approximation is not sufficient to reproduce experimental results. In our previous work, we presented the anharmonic theoretical spectra of three linear PAHs, showing the importance of including anharmonicities into the theoretical calculations. In this paper, we continue this work by extending the study to include five non-linear PAHs (benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene), thereby allowing us to make a full assessment of how edge structure, symmetry, and size influence the effects of anharmonicities. The theoretical anharmonic spectra are compared to spectra obtained under matrix isolation low-temperature conditions, low-resolution, high-temperature gas-phase conditions, and high-resolution, low-temperature gas-phase conditions. Overall, excellent agreement is observed between the theoretical and experimental spectra although the experimental spectra show subtle but significant differences.

  10. Equatorenes: synthesis and properties of chiral naphthalene, phenanthrene, chrysene, and pyrene possessing bis(1-adamantyl) groups at the peri-position.

    PubMed

    Yamamoto, Koji; Oyamada, Naohiro; Xia, Sheng; Kobayashi, Yuta; Yamaguchi, Masahiko; Maeda, Hiroaki; Nishihara, Hiroshi; Uchimaru, Tadafumi; Kwon, Eunsang

    2013-11-01

    Chiral polycyclic aromatic hydrocarbons containing bis(1-adamantyl) groups at the peri-positions, named equatorenes, were synthesized in optically pure form starting from optically pure 4,5-bis(1-adamantyl)-8-methoxy-1-naphthol. A sequential Diels-Alder reaction of furan and arynes generated from 1,2-bromotriflates provided tricyclic and tetracyclic epoxides, and acid-catalyzed aromatization gave phenanthrol and chrysenol. Deoxygenation reactions involving the hydrogenolysis of triflates gave 1,8-bis(1-adamantyl)naphthalene, 1,10-bis(1-adamantyl)phenanthrene, and 1,12-bis(1-adamantyl)chrysene. 3,4-Bis(1-adamantyl)pyrene was synthesized from phenanthrol by Sonogashira coupling and Pt-catalyzed cyclization. Essentially no racemization occurred during the synthesis. X-ray analysis indicated the distorted naphthalene moiety possessing the peri-diadamantyl groups and the flat structure of the other benzene rings. UV-vis analysis of the equatorenes showed considerable redshifts compared with that of the corresponding achiral arenes. Electrochemical analysis of the naphthalene and pyrene indicated that the distortion decreased the highest occupied molecular orbital stability with no marked effect on the lowest unoccupied molecular orbital energy level, and the origin was discussed on the basis of calculation results.

  11. Use of the phenanthrene to benzo(e)pyrene ambient air ratio as an indicator for the source of polycyclic aromatic hydrocarbons

    SciTech Connect

    Germain, A.; Ringuette, S.; Tremblay, J.

    1994-12-31

    Polycyclic aromatic hydrocarbons (PAH) are emitted by many industrial, domestic and natural sources. In 1990, the principal sources of PAH for the Province of Quebec were primary aluminum smelters (858 t), residential heating with wood (162 t), forest fires (148 t) and transportation (33 t). A sampling program was developed to measure PAH levels in ambient air at different locations influenced by these sources. The highest concentrations of PAH in ambient air (470 ng/m{sup 3} geometric mean) were measured near primary aluminum smelters using Horizontal Stud Soederberg technology. Areas influences by wood heating (157 ng/m{sup 3} winter geometric mean) and transportation (80 ng/m{sup 3} geometric mean) had lower total PAH concentrations. Ratios of ambient air concentration for phenanthrene/benzo(e)pyrene were lower in samples collected in the surroundings of the primary aluminum smelters (7--14), whereas high ratios were observed for residential heating with wood and transportation (20--45). The use of this ratio was found to be a good indicator for PAH originating from primary aluminum smelters.

  12. Using testate amoeba as potential biointegrators of atmospheric deposition of phenanthrene (polycyclic aromatic hydrocarbon) on "moss/soil interface-testate amoeba community" microecosystems.

    PubMed

    Meyer, Caroline; Desalme, Dorine; Bernard, Nadine; Binet, Philippe; Toussaint, Marie-Laure; Gilbert, Daniel

    2013-03-01

    Microecosystem models could allow understanding of the impacts of pollutants such as polycyclic aromatic hydrocarbons on ecosystem functioning. We studied the effects of atmospheric phenanthrene (PHE) deposition on the microecosystem "moss/soil interface-testate amoebae (TA) community" over a 1-month period under controlled conditions. We found that PHE had an impact on the microecosystem. PHE was accumulated by the moss/soil interface and was significantly negatively correlated (0.4 < r(2) < 0.7) with total TA abundance and the abundance of five species of TA (Arcella sp., Centropyxis sp., Nebela lageniformis, Nebela tincta and Phryganella sp.). Among sensitive species, species with a superior trophic level (determined by the test aperture size) were more sensitive than other TA species. This result suggests that links between microbial groups in the microecosystems are disrupted by PHE and that this pollutant had effects both direct (ingestion of the pollutant or direct contact with cell) and/or indirect (decrease of prey) on the TA community. The TA community seems to offer a potential integrative tool to understand mechanisms and processes by which the atmospheric PHE deposition affects the links between microbial communities.

  13. The anharmonic quartic force field infrared spectra of five non-linear polycyclic aromatic hydrocarbons: Benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene.

    PubMed

    Mackie, Cameron J; Candian, Alessandra; Huang, Xinchuan; Maltseva, Elena; Petrignani, Annemieke; Oomens, Jos; Mattioda, Andrew L; Buma, Wybren Jan; Lee, Timothy J; Tielens, Alexander G G M

    2016-08-28

    The study of interstellar polycyclic aromatic hydrocarbons (PAHs) relies heavily on theoretically predicted infrared spectra. Most earlier studies use scaled harmonic frequencies for band positions and the double harmonic approximation for intensities. However, recent high-resolution gas-phase experimental spectroscopic studies have shown that the harmonic approximation is not sufficient to reproduce experimental results. In our previous work, we presented the anharmonic theoretical spectra of three linear PAHs, showing the importance of including anharmonicities into the theoretical calculations. In this paper, we continue this work by extending the study to include five non-linear PAHs (benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene), thereby allowing us to make a full assessment of how edge structure, symmetry, and size influence the effects of anharmonicities. The theoretical anharmonic spectra are compared to spectra obtained under matrix isolation low-temperature conditions, low-resolution, high-temperature gas-phase conditions, and high-resolution, low-temperature gas-phase conditions. Overall, excellent agreement is observed between the theoretical and experimental spectra although the experimental spectra show subtle but significant differences. PMID:27586928

  14. Effect of copper on the cytotoxicity of phenanthrene and 9,10-phenanthrenequinone to the human placental cell line, JEG-3.

    PubMed

    Peters, Zachary J; Nykamp, Julie A; Passaperuma, Kavitha; Carlson, John C; DeWitte-Orr, Stephanie J; Greenberg, Bruce M; Bols, Niels C

    2007-06-01

    The trophoblast cell line, JEG-3, was used to study the cytotoxicity of phenanthrene, 9,10-phenanthrenequinone (PHEQ), anthracene, and 9,10-anthracenedione alone and with copper. The endpoints were the capacity of cultures to reduce alamar Blue (AB), a measure of energy metabolism, and to convert carboxyfluorescein diacetate acetoxymethyl ester (CFDA AM) to carboxyfluorescein, an indication of membrane integrity. Only PHEQ elicited a cytotoxic response. PHEQ caused a concentration-dependent decline in AB but not in CFDA AM readings, suggesting an impairment to energy metabolism. In the presence of copper, PHEQ concentration-response curves were shifted to the left for AB and were obtained with CFDA AM. The Cu/PHEQ synergy is attributed to an increase in redox cycling and production of reactive oxygen species (ROS), which overwhelm antioxidant defenses, damaging energy metabolism first and then membrane integrity. The impermeable copper chelator, bathocuproine, reduced the PHEQ/copper interaction, but the permeable chelator, neocuproine, and copper together were cytotoxic.

  15. High concentrations of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene and pyrene) failed to explain biochar's capacity to reduce soil nitrous oxide emissions.

    PubMed

    Alburquerque, J A; Sánchez-Monedero, M A; Roig, A; Cayuela, M L

    2015-01-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) has been postulated as a mechanism by which biochar might mitigate N(2)O emissions. We studied whether and to what extent N(2)O emissions were influenced by the three most abundant PAHs in biochar: naphthalene, phenanthrene and pyrene. We hypothesised that biochars contaminated with PAHs would show a larger N(2)O mitigation capacity and that increasing PAH concentrations in biochar would lead to higher mitigation potentials. Our results demonstrate that the high-temperature biochar (550 °C) had a higher capacity to mitigate soil N(2)O emissions than the low-temperature biochar (350 °C). At low PAH concentrations, PAHs do not significantly contribute to the reductions in soil N(2)O emissions; while biochar stimulated soil N(2)O emissions when it was spiked with high concentrations of PAHs. This study suggests that the impact of biochar on soil N(2)O emissions is due to other compositional and/or structural properties of biochar rather than to PAH concentration. PMID:25305467

  16. Structure/Reactivity Relationships in the Benzo[c]phenanthrene Skeleton: Stable Ion and Electrophilic Substitution (Nitration, Bromination) Study of Substituted Analogs; Novel Carbocations and Substituted Derivatives

    PubMed Central

    Brulé, Cédric; Laali, Kenneth K.; Okazaki, Takao; Lakshman, Mahesh K.

    2008-01-01

    A series of novel carbocations were generated by low temperature protonation of substituted benzo[c]phenanthrenes B[c]Phs and their charge delocalization pathways were elucidated by NMR based on the magnitude of Δδ13C values. It has been shown that the protonation regioselectivity is strongly controlled by methoxy and hydroxyl substituents, whose directive effects override methyl substitution effects. Regiocontrol by –OMe and –OH substituents, and its stronger influence relative to methyl groups, was also observed in the nitration and bromination reactions. Charge distribution modes in the regioisomeric protonated carbocations via parent B[c]Ph as well as in the benzylic carbocation formed via fjord-region epoxide ring opening were deduced by GIAO-DFT, and from the NPA-derived changes in charges over CHs. These patterns were compared with those derived from NMR experiments in the substituted derivatives. NMR-based charge delocalization mapping provided insight into structure/activity relationships in the methylated and fluorinated B[c]Phs. Regioselectivities observed in the nitration and bromination reactions in representative cases are the same as those via protonations. Among a group of novel nitro and bromo derivatives synthesized in this study are examples where nitro group is introduced into the fjord-region, for which X-ray structure could be obtained in one case. PMID:17394355

  17. Partition of polycyclic aromatic hydrocarbons on organobentonites from water.

    PubMed

    Chen, B L; Zhu, L Z

    2001-04-01

    A series of organobentonites synthesized by exchanging organic cation 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 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 2.621 x 10(5), 2.106 x 10(5), 2.247 x 10(4), 5.085 x 10(4), 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 1gKoc and 1gKow, 1gKoc and 1gS for PAHs in the system of

  18. Enhancement of soil retention for phenanthrene in binary cationic gemini and nonionic surfactant mixtures: characterizing two-step adsorption and partition processes through experimental and modeling approaches.

    PubMed

    Zhao, Shan; Huang, Gordon; An, Chunjiang; Wei, Jia; Yao, Yao

    2015-04-01

    The enhancement of soil retention for phenanthrene (PHE) through the addition of a binary mixture of cationic gemini (12-2-12) and nonionic surfactants (C12E10) was investigated. The maximum apparent sorption coefficient Kd(*) reached 4247.8 mL/g through the addition of mixed 12-2-12 gemini and C12E10 surfactants, which was markedly higher than the summed individual results in the presence of individual 12-2-12 gemini (1148.6 mL/g) or C12E10 (210.0 mL/g) surfactant. However, the sorption of 12-2-12 gemini was inhibited by the increasing C12E10 dose; and a higher initial 12-2-12 gemini dose showed a higher "desorption" rate. The present study also addressed the sorption behavior of the single 12-2-12 gemini surfactant at the soil/aqueous interface. The sorption isotherm was divided into two steps to elucidate the sorption process; and the sorption schematics were proposed to elaborate the growth of surfactant aggregates corresponding to the various steps of the sorption isotherm. Finally, a two-step adsorption and partition model (TAPM) was developed to simulate the sorption process. Analysis of the equilibrium data indicated that the sorption isotherms of 12-2-12 gemini fitted the TAPM model better. Thermodynamic calculations confirmed that the 12-2-12 gemini sorption at the soil/aqueous interface was spontaneous and exothermic from 288 to 308K. PMID:25576782

  19. 1-OH-Pyrene and 3-OH-Phenanthrene in Urine Show Good Relationship with their Parent Polycyclic Aromatic Hydrocarbons in Muscle in Dairy Cattle

    PubMed Central

    Kang, Hwan-Goo; Jeong, Sang-Hee

    2011-01-01

    The toxicities of phenanthrene (PH) and pyrene (PY) are less than benzo (a) pyrene (BaP) , but both compounds are found in higher concentrations in the air, feed, and food. Most PAHs are metabolized to hydroxylated compounds by the hepatic cytochrome P450 monooxigenases system. Metabolites are excreted into urine and feces. We determined concentrations of PH, PY and BaP in muscle and hydroxylated metabolites, 3-OH-PH, 1-OH-PY, and 3-OH-BaP, respectively, in urine from dairy cattle (n = 24) . We also evaluated the relationship between parent compounds in muscle and their metabolites in urine. Concentrations of PH and PY in muscle ranged from 0.7~4.8 ng/g (1.8 ± 1.7) and 0.4~4.1 ng/g (1.2 ± 1.2) , respectively. Concentrations of 3-OH-PH and 1-OH-PY in urine ranged from 0.1~5.9 ng/ml (2.9 ± 3.7) and 0.5~3.6 ng/ml (1.9 ± 2.3) , respectively. Correlation coefficient for PY concentration in muscle versus 1-OH-PY in urine was 0.657 and for PH concentration in muscle versus 3-OH-PH in urine was 0.579.Coefficient determination for PY and PH concentrations in muscle was 0.886 and for 1-OH-PY and 3-OHPH in urine was 0.834. This study suggests that 1-OH-PY and 3-OH-PH could be used as biomarkers for PAHs exposure in dairy cattle. PMID:24278545

  20. Toxicity of a PAH photooxidation product to the bacteria Photobacterium phosphoreum and the duckweed Lemna gibba: Effects of phenanthrene and its primary photoproduct, phenanthrenequinone

    SciTech Connect

    McConkey, B.J.; Duxbury, C.L.; Dixon, D.G.; Greenberg, B.M.

    1997-05-01

    Phenanthrene (PHE) undergoes a significant increase in toxicity after exposure to simulated or natural sunlight in aqueous media, coincident with the appearance of PHE photoproducts. To investigate whether the primary photoproduct of PHE, 9,10-phenanthrenequinone (PHEQ), contributes to the increased hazards of solutions containing photomodified PHE, toxicity assays were conducted using the marine bacteria Photobacterium phosphoreum and the aquatic plant Lemna gibba (duckweed). Photobacterium phosphoreum was exposed to PHE, PHEQ, a photomodified PHE mixture containing known amounts of PHE and PHEQ (pmPHE), and a mixture mimicking the amounts of PHE and PHEQ in the pmPHE mixture. The bacteria were found to be equally sensitive to PHE in simulated solar radiation or darkness, with an EC50 of 0.53 mg/L. In both darkness or SSR, solutions containing PHEQ (with or without PHE) all exhibited an EC50 of 0.06 to 0.10 mg/L based on PHEQ concentrations, indicating that PHEQ was the primary active component of the pmPHE mixture. Lemna gibba was tested in SSR and visible light with PHE, PHEQ, and the pmPHE mixture. The calculated EC50 for PHE was 3.5 mg/L in SSR and 10.8 mg/L in visible light, showing that the presence of UV radiation in the SSR source increased the phytotoxicity of PHE. Strikingly, PHEQ was much more toxic to L. gibba than PHE in a light-independent manner. Thus, for both P. phosphoreum and L. gibba the major photooxidation product of PHE in SSR, PHEQ, is the more toxic of the two chemicals.

  1. Generation and distribution of PAHs in the process of medical waste incineration.

    PubMed

    Chen, Ying; Zhao, Rongzhi; Xue, Jun; Li, Jinhui

    2013-05-01

    After the deadly earthquake on May 12, 2008 in Wenchuan county of China, several different incineration approaches were used for medical waste disposal. This paper investigates the generation properties of polycyclic aromatic hydrocarbons (PAHs) during the incineration. Samples were collected from the bottom ash in an open burning slash site, surface soil at the open burning site, bottom ash from a simple incinerator, bottom ash generated from the municipal solid waste (MSW) incinerator used for medical waste disposal, and bottom ash and fly ash from an incinerator exclusively used for medical waste. The species of PAHs were analyzed, and the toxicity equivalency quantities (TEQs) of samples calculated. Analysis results indicate that the content of total PAHs in fly ash was 1.8×10(3) times higher than that in bottom ash, and that the strongly carcinogenic PAHs with four or more rings accumulated sensitively in fly ash. The test results of samples gathered from open burning site demonstrate that Acenaphthylene (ACY), Acenaphthene (ACE), Fluorene (FLU), Phenanthrene (PHE), Anthracene (ANT) and other PAHs were inclined to migrate into surrounding environment along air and surface watershed corridors, while 4- to 6-ring PAHs accumulated more likely in soil. Being consistent with other studies, it has also been confirmed that increases in both free oxygen molecules and combustion temperatures could promote the decomposition of polycyclic PAHs. In addition, without the influence of combustion conditions, there is a positive correlation between total PCDD/Fs and total PAHs, although no such relationship has been found for TEQ. PMID:23462270

  2. Pseudomonads Rule Degradation of Polyaromatic Hydrocarbons in Aerated Sediment

    PubMed Central

    Wald, Jiri; Hroudova, Miluse; Jansa, Jan; Vrchotova, Blanka; Macek, Tomas; Uhlik, Ondrej

    2015-01-01

    Given that the degradation of aromatic pollutants in anaerobic environments such as sediment is generally very slow, aeration could be an efficient bioremediation option. Using stable isotope probing (SIP) coupled with pyrosequencing analysis of 16S rRNA genes, we identified naphthalene-utilizing populations in aerated polyaromatic hydrocarbon (PAH)-polluted sediment. The results showed that naphthalene was metabolized at both 10 and 20°C following oxygen delivery, with increased degradation at 20°C as compared to 10°C—a temperature more similar to that found in situ. Naphthalene-derived 13C was primarily assimilated by pseudomonads. Additionally, Stenotrophomonas, Acidovorax, Comamonas, and other minor taxa were determined to incorporate 13C throughout the measured time course. The majority of SIP-detected bacteria were also isolated in pure cultures, which facilitated more reliable identification of naphthalene-utilizing populations as well as proper differentiation between primary consumers and cross-feeders. The pseudomonads acquiring the majority of carbon were identified as Pseudomonas veronii and Pseudomonas gessardii. Stenotrophomonads and Acidovorax defluvii, however, were identified as cross-feeders unable to directly utilize naphthalene as a growth substrate. PAH degradation assays with the isolated bacteria revealed that all pseudomonads as well as Comamonas testosteroni degraded acenaphthene, fluorene, and phenanthrene in addition to naphthalene. Furthermore, P. veronii and C. testosteroni were capable of transforming anthracene, fluoranthene, and pyrene. Screening of isolates for naphthalene dioxygenase genes using a set of in-house designed primers for Gram-negative bacteria revealed the presence of such genes in pseudomonads and C. testosteroni. Overall, our results indicated an apparent dominance of pseudomonads in the sequestration of carbon from naphthalene and potential degradation of other PAHs upon aeration of the sediment at both 20 and

  3. A Potential Impact on the Chemical Composition in the Marine Boundary Layer in the Arctic Ocean by Ship Emissions

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Wang, X.; Blum, J. D.; Sun, L.

    2005-12-01

    Samples of aerosols in the marine boundary layer (MBL) of the Arctic Ocean were collected aboard R/V ()Xuelong during the summer on the Second Chinese Arctic Research Expedition (July-September, 2003). Chemical compositions including major and trace elements and polycyclic aromatic hydrocarbons (PAHs) in aerosol particles were analyzed. Results showed that significant amounts of S, Fe, V and Ni are emitted from ship diesel engines and contaminate the ambient air. The total amount of Fe, which plays a significant role in the ocean ()biological pump, emitted from ships in the Arctic is estimated at 4.33-A106 kg yr-1. Sulfur emitted into the atmosphere may be transformed to sulfur acid and result in a chlorine depletion in sea-salt. Because the global inventory of sulfur from ship exhausts is large and halogens may have important consequences in possible tropospheric ozone destruction, the role of ships in effecting halogen depression in sea-salt should be evaluated. For organic compounds, 17 PAHs including Fluoranthene, Phenanthrene, Chrysene, Indeno[123-cd]pyrene, Pyrene, Benzo[b]fluoranthene, Benzo[ghi]pyrene, Naphthalene, Benzo[a]anthracene, Benzo[k]fluoranthene, Coronene, Fluorene, Benzo[a]pyrene, Acenaphthene, Anthracene, Dibenzo[a,h]anthracene and Acenaphthylene were detected. The average levels of subspecies of PAHs in ambient air ranged from 0.003 to 0.089 ng/m3. Among the 17 PAHs, fluoranthene had a relative high level, while the level of acenaphthylene was relative low. The aerosols contaminated by the ship, which were commonly excluded in previous investigations, thus provide an opportunity to investigate and understand the role of ship emissions in the atmospheric chemistry of the marine boundary layer, especially in the Arctic Ocean.

  4. [An investigation of the formation of] polycyclic aromatic hydrocarbon (PAH) emissions when firing pulverized coal in a bench-scale drop tube reactor

    SciTech Connect

    Pisupati, S.V.; Wasco, R.S.; Scaroni, A.W.

    1998-12-31

    The Clean Air Act Amendments (CAAA) of 1990 contain provisions which will set standards for the allowable emissions of 188 analytes designated as hazardous air pollutants (HAPs). This list of HAPs was used to establish an initial list of source categories for which EPA would be required to establish technology-based emission standards, which would result in regulated sources sharply reducing routine emissions of toxic air pollutants. Polycyclic organic matter (POM) has also been referred to as polynuclear or polycyclic aromatic compounds (PACs). Nine major categories of POM have been defined by EPA. The study of organic compounds from coal combustion is complex and the results obtained so far are inconclusive with respect to emission factors. The most common organic compounds in the flue gas of coal-fired power plants are polycyclic aromatic hydrocarbons (PAHs). Furthermore, EPA has specified 16 PAH compounds as priority pollutants. These are naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, benzo[ghi]perylene, and dibenz[ah]anthracene. Penn State`s Combustion Laboratory is equipped to collect and analyze the HAPs in the flue gas from fossil fuels combustion. The overall objective of this study was to examine the effect of unit temperature on PAH emissions. A Modified Method 5 sampling train was used to isokinetically collect samples at desired locations in flue gas streams. The collected sample can be separated into solid, condensed liquid and gaseous phases. The PAHs of interest are extracted from the collected sample, concentrated, then separated and quantified by gas chromatography/mass spectrometry (GC/MS). This study was conducted using a bench-scale drop-tube reactor (DTR). The fuel selected for this study was a Middle Kittanning seam coal pulverized to 80% passing US Standard 200 mesh (commonly

  5. Response of microbial activities and diversity to PAHs contamination at coal tar contaminated land

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaohui; Sun, Yujiao; Ding, Aizhong; Zhang, Dan; Zhang, Dayi

    2015-04-01

    Coal tar is one of the most hazardous and concerned organic pollutants and the main hazards are polycyclic aromatic hydrocarbons (PAHs). The indigenous microorganisms in soils are capable to degrade PAHs, with essential roles in biochemical process for PAHs natural attenuation. This study investigated 48 soil samples (from 8 depths of 6 boreholes) in Beijing coking and chemistry plant (China) and revealed the correlation between PAHs contamination, soil enzyme activities and microbial community structure, by 16S rRNA denaturing gradient gel electrophoresis (DGGE). At the site, the key contaminants were identified as naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene, and the total PAHs concentration ranged from 0.1 to 923.9 mg/kg dry soil. The total PAHs contamination level was positively correlated (p<0.05) with the bacteria count (0.9×107-14.2×107 CFU/mL), catalase activities (0.554-6.230 mL 0.02 M KMnO4/g•h) and dehydrogenase activities (1.9-30.4 TF μg/g•h soil), showing the significant response of microbial population and degrading functions to the organic contamination in soils. The PAHs contamination stimulated the PAHs degrading microbes and promoted their biochemical roles in situ. The positive relationship between bacteria count and dehydrogenase activities (p<0.05) suggested the dominancy of PAHs degrading bacteria in the microbial community. More interestingly, the microbial community deterioration was uncovered via the decline of microbial biodiversity (richness from 16S rRNA DGGE) against total PAHs concentration (p<0.05). Our research described the spatial profiles of PAHs contamination and soil microbial functions at the PAHs heavily contaminated sites, offering deeper understanding on the roles of indigenous microbial community in natural attenuation process.

  6. Modeling of experimental data on trace elements and organic compounds content in industrial waste dumps.

    PubMed

    Smoliński, Adam; Drobek, Leszek; Dombek, Václav; Bąk, Andrzej

    2016-11-01

    The main objective of the study presented was to investigate the differences between 20 mine waste dumps located in the Silesian Region of Poland and Czech Republic, in terms of trace elements and polycyclic aromatic hydrocarbons contents. The Principal Component Analysis and Hierarchical Clustering Analysis were applied in exploration of the studied data. Since the data set was affected by outlying objects, the employment of a relevant analysis strategy was necessary. The final PCA model was constructed with the use of the Expectation-Maximization iterative approach preceded by a correct identification of outliers. The analysis of the experimental data indicated that three mine waste dumps located in Poland were characterized by the highest concentrations of dibenzo(g,h,i)anthracene and benzo(g,h,i)perylene, and six objects located in Czech Republic and three objects in Poland were distinguished by high concentrations of chrysene and indeno (1.2.3-cd) pyrene. Three of studied mine waste dumps, one located in Czech Republic and two in Poland, were characterized by low concentrations of Cr, Ni, V, naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthen, benzo(a)anthracene, chrysene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo(a)pyrene, dibenzo(g,h,i)anthracene, benzo(g,h,i)perylene and indeno (1.2.3-cd) pyrene in comparison with the remaining ones. The analysis contributes to the assessment and prognosis of ecological and health risks related to the emission of trace elements and organic compounds (PAHs) from the waste dumps examined. No previous research of similar scope and aims has been reported for the area concerned. PMID:27497349

  7. Miniscale Liquid-Liquid Extraction Coupled with Full Evaporation Dynamic Headspace Extraction for the Gas Chromatography/Mass Spectrometric Analysis of Polycyclic Aromatic Hydrocarbons with 4000-to-14 000-fold Enrichment.

    PubMed

    Liew, Christina Shu Min; Li, Xiao; Lee, Hian Kee

    2016-09-20

    A new sample preparation approach of combining a miniscale version of liquid-liquid extraction (LLE), termed miniscale-LLE (msLLE), with automated full evaporation dynamic headspace extraction (FEDHS) was developed. Its applicability was demonstrated in the extraction of several polycyclic aromatic hydrocarbons (PAHs) (acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene) from aqueous samples. In the first step, msLLE was conducted with 1.75 mL of n-hexane, and all of the extract was vaporized through a Tenax TA sorbent tube via a nitrogen gas flow, in the FEDHS step. Due to the stronger π-π interaction between the Tenax TA polymer and PAHs, only the latter, and not n-hexane, was adsorbed by the sorbent. This selectivity by the Tenax TA polymer allowed an effective concentration of PAHs while eliminating n-hexane by the FEDHS process. After that, thermal desorption was applied to the PAHs to channel them into a gas chromatography/mass spectrometric (GC/MS) system for analysis. Experimental parameters affecting msLLE (solvent volume and mixing duration) and FEDHS (temperature and duration) were optimized. The obtained results achieved low limits of detection (1.85-3.63 ng/L) with good linearity (r(2) > 0.9989) and high enrichment factors ranging from 4200 to 14 100. The optimized settings were applied to the analysis of canal water sampled from an industrial area and tap water, and this methodology was compared to stir-bar sorptive extraction (SBSE). This innovative combined extraction-concentration approach proved to be fast, effective, and efficient in determining low concentrations of PAHs in aqueous samples.

  8. Fate of aromatic hydrocarbons in Italian municipal wastewater systems: an overview of wastewater treatment using conventional activated-sludge processes (CASP) and membrane bioreactors (MBRs).

    PubMed

    Fatone, Francesco; Di Fabio, Silvia; Bolzonella, David; Cecchi, Franco

    2011-01-01

    We studied the occurrence, removal, and fate of 16 polycyclic aromatic hydrocarbons (PAHs) and 23 volatile organic compounds (VOCs) in Italian municipal wastewater treatment systems in terms of their common contents and forms, and their apparent and actual removal in both conventional activated-sludge processes (CASP) and membrane bioreactors (MBRs). We studied five representative full-scale CASP treatment plants (design capacities of 12,000 to 700,000 population-equivalent), three of which included MBR systems (one full-scale and two pilot-scale) operating in parallel with the conventional systems. We studied the solid-liquid partitioning and fates of these substances using both conventional samples and a novel membrane-equipped automatic sampler. Among the VOCs, toluene, ethylbenzene, xylenes, styrene, 1,2,4-trimethylbenzene, and 4-chlorotoluene were ubiquitous, whereas naphthalene, acenaphthene, fluorene, and phenanthrene were the most common PAHs. Both PAHs and aromatic VOCs had removal efficiencies of 40-60% in the headworks, even in plants without primary sedimentation. Mainly due to volatilization, aromatic VOCs had comparable removal efficiencies in CASP and MBRs, even for different sludge ages. MBRs did not enhance the retention of PAHs sorbed to suspended particulates compared with CASPs. On the other hand, the specific daily accumulation of PAHs in the MBR's activated sludge decreased logarithmically with increasing sludge age, indicating enhanced biodegradation of PAHs. The PAH and aromatic VOC contents in the final effluent are not a major driver for widespread municipal adoption of MBRs, but MBRs may enhance the biodegradation of PAHs and their removal from the environment.

  9. Round robin investigation of organic compounds in aqueous leachates of solid wastes: application to H-coal filter cake leachates

    SciTech Connect

    Avery, M.; Hilpert, L.; Jackson, L.; Junk, G.; Maskarinec, M.; Paule, R.C.; Raphaelian, L.; Richard, J.; White, C.M.

    1985-01-01

    The work presented in this report details efforts of six laboratories to develop methods for the analysis of aqueous leachates from fossil fuel solid wastes and to determine their accuracy and precision. Quantitative data on the concentrations of seventeen target organic compounds in aqueous leachates of a fossil fuel waste are presented. Many of the target analytes were selected from Appendices VII and VIII, of the May 19th, 1980, Federal Register. Some organic compounds that are not present in Appendices VII and VIII were also selected because of the probability of their presence in fossil fuel products, by-products, and wastes. These target analytes and four standard compounds that were used as internal standards are the following: Benz(a)anthracene, o-Cresol, Phenanthrene, Carbazole, Naphthalene, 1,4-Naphthoquinone, Phenol, 2-Fluorophenol (standard), n-Octacosane (standard), Azulene (standard), 2,3,4,5-Tetrachlorobiphenyl (standard), n-Tetradecane, 2-Naphthol, n-Hexanoic acid, Dibenzothiophene, Quinoline, Acenaphthylene, 1-Naphthylamine, 2-Picoline, 4-Aminobiphenyl, and Fluoranthene. An analytical method for the determination of organic compounds in aqueous leachates has been developed. This method was evaluated using a series of samples of increasing complexity, starting with simple synthetic aqueous leachates and ending with leachates of fossil fuel wastes. The present report describes the analytical results from four laboratories applying the previously developed analytical method to leachates of an H-Coal filter cake material. These leachates were obtained using both the standard ASTM Method D3987 and the EP leaching procedures. Ten additional compounds of interest were identified in the extract: Indan, Tetralin, 2-Methylnaphthalene, 1-Methylnaphthalene, Tetrahydroacenaphthene, Biphenyl, Acenaphthene, Dibenzofuran, Fluorene, and Diphenyl Ether. 11 references, 2 figures, 16 tables.

  10. Generation and distribution of PAHs in the process of medical waste incineration

    SciTech Connect

    Chen, Ying; Zhao, Rongzhi; Xue, Jun; Li, Jinhui

    2013-05-15

    Highlights: ► PAHs generation and distribution features of medical waste incineration are studied. ► More PAHs were found in fly ash than that in bottom ash. ► The highest proportion of PAHs consisted of the seven most carcinogenic ones. ► Increase of free oxygen molecule and burning temperature promote PAHs degradation. ► There is a moderate positive correlation between total PCDD/Fs and total PAHs. - Abstract: After the deadly earthquake on May 12, 2008 in Wenchuan county of China, several different incineration approaches were used for medical waste disposal. This paper investigates the generation properties of polycyclic aromatic hydrocarbons (PAHs) during the incineration. Samples were collected from the bottom ash in an open burning slash site, surface soil at the open burning site, bottom ash from a simple incinerator, bottom ash generated from the municipal solid waste (MSW) incinerator used for medical waste disposal, and bottom ash and fly ash from an incinerator exclusively used for medical waste. The species of PAHs were analyzed, and the toxicity equivalency quantities (TEQs) of samples calculated. Analysis results indicate that the content of total PAHs in fly ash was 1.8 × 10{sup 3} times higher than that in bottom ash, and that the strongly carcinogenic PAHs with four or more rings accumulated sensitively in fly ash. The test results of samples gathered from open burning site demonstrate that Acenaphthylene (ACY), Acenaphthene (ACE), Fluorene (FLU), Phenanthrene (PHE), Anthracene (ANT) and other PAHs were inclined to migrate into surrounding environment along air and surface watershed corridors, while 4- to 6-ring PAHs accumulated more likely in soil. Being consistent with other studies, it has also been confirmed that increases in both free oxygen molecules and combustion temperatures could promote the decomposition of polycyclic PAHs. In addition, without the influence of combustion conditions, there is a positive correlation between

  11. A comparison of physicochemical methods for the remediation of porous medium systems contaminated with tar

    NASA Astrophysics Data System (ADS)

    Hauswirth, Scott C.; Miller, Cass T.

    2014-10-01

    The remediation of former manufactured gas plant (FMGP) sites contaminated with tar DNAPLs (dense non-aqueous phase liquids) presents a significant challenge. The tars are viscous mixtures of thousands of individual compounds, including known and suspected carcinogens. This work investigates the use of combinations of mobilization, solubilization, and chemical oxidation approaches to remove and degrade tars and tar components in porous medium systems. Column experiments were conducted using several flushing solutions, including an alkaline-polymer (AP) solution containing NaOH and xanthan gum (XG), a surfactant-polymer (SP) solution containing Triton X-100 surfactant (TX100) and XG, an alkaline-surfactant-polymer (ASP) solution containing NaOH, TX100, and XG, and base-activated sodium persulfate both with and without added TX100. The effectiveness of the flushing solutions was assessed based on both removal of polycyclic aromatic hydrocarbon (PAH) mass and on the reduction of dissolved-phase PAH concentrations. SP flushes of 6.6 to 20.9 PV removed over 99% of residual PAH mass and reduced dissolved-phase concentrations by up to two orders of magnitude. ASP flushing efficiently removed 95-96% of residual PAH mass within about 2 PV, and significantly reduced dissolved-phase concentrations of several low molar mass compounds, including naphthalene, acenaphthene, fluorene, and phenanthrene. AP flushing removed a large portion of the residual tar (77%), but was considerably less effective than SP and ASP in terms of the effect on dissolved PAH concentrations. Persulfate was shown to oxidize tar components, primarily those with low molar mass, however, the overall degradation was relatively low (30-50% in columns with low initial tar saturations), and the impact on dissolved-phase concentrations was minimal.

  12. Hard Cap Espresso Machines in Analytical Chemistry: What Else?

    PubMed

    Armenta, Sergio; de la Guardia, Miguel; Esteve-Turrillas, Francesc A

    2016-06-21

    A hard cap espresso machine has been used in combination with liquid chromatography with molecular fluorescence detection for the determination of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils and sediments providing appropriate extraction efficiencies and quantitative results. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benz[b]fluoranthene, benz[k]fluoranthene, benz[a]pyrene, dibenz[a,h]anthracene, benz[ghi]perylene, and indeno[1,2,3-cd]pyrene were used as target compounds. It should be mentioned that the pairs benz[a]anthracene-chrysene and dibenz[a,h]anthracene-benz[ghi]perylene peaks coelute under the employed chromatographic conditions; thus, those compounds were determined together. PAHs were extracted from 5.0 g of soil, previously homogenized, freeze-dried, and sieved to 250 μm, with 50 mL of 40% (v/v) acetonitrile in water at a temperature of 72 ± 3 °C. The proposed procedure is really fast, with an extraction time of 11 s, and it reduces the required amount of organic solvent to do the sample preparation. The obtained limit of detection for the evaluated PAHs was from 1 to 38 μg kg(-1). Recoveries were calculated using clean soils spiked with 100, 500, 1000, and 2000 μg kg(-1) PAHs with values ranging from 81 to 121% and good precision with relative standard deviation values lower than 30%. The method was validated using soil and sediment certified reference materials and also using real samples by comparison with ultrasound-assisted extraction, as reference methodology, obtaining statistically comparable results. Thus, the use of hard cap espresso machines in the analytical laboratories offers tremendous possibilities as low cost extraction units for the extraction of solid samples.

  13. Miniscale Liquid-Liquid Extraction Coupled with Full Evaporation Dynamic Headspace Extraction for the Gas Chromatography/Mass Spectrometric Analysis of Polycyclic Aromatic Hydrocarbons with 4000-to-14 000-fold Enrichment.

    PubMed

    Liew, Christina Shu Min; Li, Xiao; Lee, Hian Kee

    2016-09-20

    A new sample preparation approach of combining a miniscale version of liquid-liquid extraction (LLE), termed miniscale-LLE (msLLE), with automated full evaporation dynamic headspace extraction (FEDHS) was developed. Its applicability was demonstrated in the extraction of several polycyclic aromatic hydrocarbons (PAHs) (acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene) from aqueous samples. In the first step, msLLE was conducted with 1.75 mL of n-hexane, and all of the extract was vaporized through a Tenax TA sorbent tube via a nitrogen gas flow, in the FEDHS step. Due to the stronger π-π interaction between the Tenax TA polymer and PAHs, only the latter, and not n-hexane, was adsorbed by the sorbent. This selectivity by the Tenax TA polymer allowed an effective concentration of PAHs while eliminating n-hexane by the FEDHS process. After that, thermal desorption was applied to the PAHs to channel them into a gas chromatography/mass spectrometric (GC/MS) system for analysis. Experimental parameters affecting msLLE (solvent volume and mixing duration) and FEDHS (temperature and duration) were optimized. The obtained results achieved low limits of detection (1.85-3.63 ng/L) with good linearity (r(2) > 0.9989) and high enrichment factors ranging from 4200 to 14 100. The optimized settings were applied to the analysis of canal water sampled from an industrial area and tap water, and this methodology was compared to stir-bar sorptive extraction (SBSE). This innovative combined extraction-concentration approach proved to be fast, effective, and efficient in determining low concentrations of PAHs in aqueous samples. PMID:27535573

  14. A comparison of physicochemical methods for the remediation of porous medium systems contaminated with tar.

    PubMed

    Hauswirth, Scott C; Miller, Cass T

    2014-10-15

    The remediation of former manufactured gas plant (FMGP) sites contaminated with tar DNAPLs (dense non-aqueous phase liquids) presents a significant challenge. The tars are viscous mixtures of thousands of individual compounds, including known and suspected carcinogens. This work investigates the use of combinations of mobilization, solubilization, and chemical oxidation approaches to remove and degrade tars and tar components in porous medium systems. Column experiments were conducted using several flushing solutions, including an alkaline-polymer (AP) solution containing NaOH and xanthan gum (XG), a surfactant-polymer (SP) solution containing Triton X-100 surfactant (TX100) and XG, an alkaline-surfactant-polymer (ASP) solution containing NaOH, TX100, and XG, and base-activated sodium persulfate both with and without added TX100. The effectiveness of the flushing solutions was assessed based on both removal of polycyclic aromatic hydrocarbon (PAH) mass and on the reduction of dissolved-phase PAH concentrations. SP flushes of 6.6 to 20.9 PV removed over 99% of residual PAH mass and reduced dissolved-phase concentrations by up to two orders of magnitude. ASP flushing efficiently removed 95-96% of residual PAH mass within about 2 PV, and significantly reduced dissolved-phase concentrations of several low molar mass compounds, including naphthalene, acenaphthene, fluorene, and phenanthrene. AP flushing removed a large portion of the residual tar (77%), but was considerably less effective than SP and ASP in terms of the effect on dissolved PAH concentrations. Persulfate was shown to oxidize tar components, primarily those with low molar mass, however, the overall degradation was relatively low (30-50% in columns with low initial tar saturations), and the impact on dissolved-phase concentrations was minimal.

  15. Crystal structure of 7-isopropyl-1,4a,N-trimethyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca-hydro-phenanthrene-1-carb-ox-amide.

    PubMed

    Liu, Li; Yan, Xin-Yan; Rao, Xiao-Ping

    2015-10-01

    In the title compound, C26H37NO, a new derivative of di-hydro-abietic acid, the two cyclo-hexene rings adopt half chair conformations, whereas the cyclo-hexane ring has a chair conformation. Each of the methyl groups is in an axial position with respect to the tricyclic hydro-phenanthrene residue. In the crystal packing, methyl-ene-C-H⋯π(phen-yl) inter-actions lead to supra-molecular helical chains along [010]; the amide-H atom does not form a significant inter-molecular inter-action owing to steric pressure.

  16. Crystal structure of 7-isopropyl-1,4a,N-trimethyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca-hydro-phenanthrene-1-carb-ox-amide.

    PubMed

    Liu, Li; Yan, Xin-Yan; Rao, Xiao-Ping

    2015-10-01

    In the title compound, C26H37NO, a new derivative of di-hydro-abietic acid, the two cyclo-hexene rings adopt half chair conformations, whereas the cyclo-hexane ring has a chair conformation. Each of the methyl groups is in an axial position with respect to the tricyclic hydro-phenanthrene residue. In the crystal packing, methyl-ene-C-H⋯π(phen-yl) inter-actions lead to supra-molecular helical chains along [010]; the amide-H atom does not form a significant inter-molecular inter-action owing to steric pressure. PMID:26594487

  17. Malignant transformation of human colon epithelial cells by benzo[c]phenanthrene dihydrodiolepoxides as well as 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine

    SciTech Connect

    Herbst, Uta; Fuchs, Judith Iris; Teubner, Wera; Steinberg, Pablo . E-mail: steinber@rz.uni-potsdam.de

    2006-04-15

    Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) ingested with food have repeatedly been suggested to be involved in the malignant transformation of colon epithelial cells. In order to test this hypothesis, HCEC cells (SV40 large T antigen-immortalized human colon epithelial cells) were incubated with a racemic mixture of benzo[c]phenanthrene dihydrodiol epoxides (B[c]PhDE), extremely potent carcinogenic PAH metabolites in vivo, or with 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), the N-hydroxylated metabolite of the most abundant HCA in cooked meat. First, it was shown that HCEC cells express sulfotransferase 1A1, which is needed to metabolize N-OH-PhIP to the corresponding N-sulfonyloxy derivative, the direct precursor molecule of genotoxic nitrenium ions. Thereafter, exponentially growing HCEC cells were exposed five times to 0.1 {mu}g (0.37 nmol) B[c]PhDE/ml for 30 min or 0.72 {mu}g (3 nmol) N-OH-PhIP/ml for 24 h. Chemically treated HCEC cells showed an enhanced saturation density and grew faster than the corresponding solvent-treated cell cultures. After five treatment cycles, HCEC{sup B[c]PhDE} as well as HCEC {sup N-OH-PhIP} cells lost cell-cell contact inhibition and started piling up and forming foci in the culture flasks. Furthermore, HCEC{sup B[c]PhDE} and HCEC {sup N-OH-PhIP} cells were injected i.m. into SCID mice. Within 6 weeks after injection, eight animals out of eight injected with HCEC{sup B[c]PhDE} or HCEC {sup N-OH-PhIP} cells developed tumors at the site of injection, thus demonstrating the high tumorigenic potential of the HCEC{sup B[c]PhDE} and HCEC {sup N-OH-PhIP} cell cultures. Taken together, we show for the first time that the abovementioned active PAH metabolites as well as N-OH-PhIP are indeed able to malignantly transform human colon epithelial cells in vitro.

  18. Photochemistry of (η(6)-arene)Cr(CO)3 (arene = methylbenzoate, naphthalene, or phenanthrene) in n-heptane solution: population of two excited states following 400 nm excitation as detected by picosecond time-resolved infrared spectroscopy.

    PubMed

    Clark, Ian P; George, Michael W; Greetham, Gregory M; Harvey, Emma C; Long, Conor; Manton, Jennifer C; Pryce, Mary T

    2011-04-14

    The photochemistry of (η(6)-methylbenzoate)Cr(CO)(3), (η(6)-naphthalene)Cr(CO)(3), and (η(6)-phenanthrene)Cr(CO)(3) in n-heptane solution was investigated by picosecond time-resolved infrared spectroscopy (TRIR). The observation of two transient IR features in the organic carbonyl region at 1681 and 1724 cm(-1) following 400 nm excitation of (η(6)-methylbenzoate)Cr(CO)(3) confirms formation of two excited states which are classified as metal-to-arene charge transfer (MACT) and metal-to-CO charge transfer (MCCT), respectively. Time-dependent density functional theory calculations have been used to support these assignments. Population of the MCCT excited state results in a slow (150 ps) expulsion of one CO ligand. Excitation of (η(6)-naphthalene)Cr(CO)(3) or (η(6)-phenanthrene)Cr(CO)(3) at either 400 or 345 nm produced two excited states: the MCCT state results in CO loss, while the MACT excited state results in a change to the coordination mode of the polyaromatic ligands before relaxing to the parent complex. A comparison of the infrared absorptions observed following the population of the MACT excited state with those calculated for nonplanar polyaromatic intermediates provides a model for the reduced hapticity species.

  19. A femtosecond study of the anomaly in electron injection for dye-sensitized solar cells: the influence of isomerization employing Ru(II) sensitizers with anthracene and phenanthrene ancillary ligands.

    PubMed

    Cheema, Hammad; Younts, Robert; Ogbose, Louis; Gautam, Bhoj; Gundogdu, Kenan; El-Shafei, Ahmed

    2015-01-28

    In this study, an intriguing difference caused by structural isomerization based on anthracene and phenanthrene stilbazole type ancillary ligands in Ru(ii) sensitizers for dye sensitized solar cells (DSCs) has been investigated using femtosecond transient absorption spectroscopy. Both anthracene and phenanthrene based sensitizers HD-7 and HD-8, respectively, resulted in a similar extinction coefficient, photophysical and thermodynamic free energy of electron injection and dye regeneration as measured by UV-Vis, excited state lifetime and cyclic voltammetry measurements, respectively. However, TiO2 adsorbed HD-7 resulted in up to 45% less photocurrent density than HD-8 although photovoltage was similar owing to comparable thermodynamic characteristics. It was obvious from the measurement of incident photon to current conversion efficiency (IPCE) that excited electrons in HD-7 are prone to internal energy loss before injection into the TiO2 conduction band. Analysis of photo-induced spectral features measured by femtosecond transient absorption spectroscopy showed that excited electrons in HD-7 are prone to ISC (intersystem crossing) much more than HD-8 and those triplet electrons are not injected into TiO2 efficiently. Interestingly, from impedance measurements, HD-7 showed higher recombination resistance than HD-8 and N719, but a shorter lifetime for electrons injected into the TiO2 conduction band.

  20. Arbuscular mycorrhizal fungal hyphae contribute to the uptake of polycyclic aromatic hydrocarbons by plant roots.

    PubMed

    Gao, Yanzheng; Cheng, Zhaoxia; Ling, Wanting; Huang, Jing

    2010-09-01

    The arbuscular mycorrhizal (AM) hyphae-mediated uptake of polycyclic aromatic hydrocarbons (PAHs) by the roots of ryegrass (Lolium multiflorum Lam.) was investigated using three-compartment systems. Glomus mosseae and Glomus etunicatum were chosen, and fluorene and phenanthrene were used as representative PAHs. When roots were grown in un-spiked soils, AM hyphae extended into PAH-spiked soil and clearly absorbed and transported PAHs to roots, resulting in high concentrations of fluorene and phenanthrene in roots. This was further confirmed by the batch equilibration experiment, which revealed that the partition coefficients (K(d)) of tested PAHs by mycorrhizal hyphae were 270-356% greater than those by roots, suggesting the great potential of hyphae to absorb PAHs. Because of fluorene's lower molecular weight and higher water solubility, its translocation by hyphae was greater than that of phenanthrene. These results provide new perspectives on the AM hyphae-mediated uptake by plants of organic contaminants from soil. PMID:20403686

  1. Identifying Boundary-Layer Transitions on Aircraft Skin

    NASA Technical Reports Server (NTRS)

    Holmes, B. J.; Croom, C. C.; Kelliher, W. C.; Obara, C. J.

    1984-01-01

    Sublimating chemicals offer accurate, low-cost way of indicating laminarto-turbulent flow transisions on surfaces of aircraft. Aerodynamic surfaces coated with thin film of such volatile chemical solids as naphthalene, diphenyl, acenaphthene, or fluorene. Film sublimes rapidly because of high local shear stress and heat transfer in boundary layer. Coating appears white in regions where chemical remained on surface indicating laminar flow; regions where chemical disappeared indicate turbulent flow.

  2. Crystal structure of catena-poly[[di­aqua(4,5-di­aza­fluoren-9-one-κ2 N,N′)cadmium]-μ-2-hydroxy-5-sulfonato­benzoato-κ3 O 1,O 1′:O 5

    PubMed Central

    Wang, Chun-Xiang; Li, Zhi-Feng

    2014-01-01

    In the polymeric title compound, [Cd(C7H4O6S)(C11H6N2O)(H2O)2]n, the Cd2+ atom is seven-coordinated by two water O atoms, by three O atoms from two 2-hy­droxy-5-sulfonato­benzoate (Hssal2−) ligands and by two N atoms from a 4,5-di­aza­fluoren-9-one (Dafo) ligand in a distorted penta­gonal–bipyramidal geometry. The Cd2+ atoms are monodentately coordinated by the sulfonate group of one Hssal2− ligand and bidentately coordinated by the carboxyl­ate group of another Hssal2− ligand, generating zigzag chains running parallel to [010]. The chains are linked by O—H⋯O hydrogen bonds into a three-dimensional architecture. PMID:25484789

  3. Changes in the adsorption of bisphenol A, 17 α-ethinyl estradiol, and phenanthrene on marine sediment in Hong Kong in relation to the simulated sediment organic matter decomposition.

    PubMed

    Fei, Ying-heng; Xing, Baoshan; Li, Xiao-yan

    2014-09-01

    Marine sediment with an input of particulate organic matter was incubated to simulate the early aging process. On the sediment after various incubation periods, adsorption and desorption tests were conducted for three selected organic micropollutants: bisphenol A (BPA), 17α-ethinyl estradiol (EE2), and phenanthrene (Phe). The results showed significant sediment organic matter (SOM) decomposition during the incubation, and the SOM decay and transformation had a profound impact on the adsorption of organic compounds by the sediment. An increasing-delay-increasing pattern of change was observed for the SOM normalized partition coefficients of EE2 and Phe. This change was accordant to the transformation of SOM from labile organics into active biomass and its microbial products, and finally into more condensed and humic-like substances. Comparison between the 3 model micropollutants indicates that the chemical adsorption behaviors were mostly affected by their hydrophobic properties. PMID:24929636

  4. Crystal structure of 2,2′′-bis­(2,7-di­chloro-9-hy­droxy-9H-fluoren-9-yl)-1,1′:4′,1′′-terphenyl tri­ethyl­amine trisolvate

    PubMed Central

    Klien, Henrik; Seichter, Wilhelm; Weber, Edwin

    2015-01-01

    In the title solvate, C44H26Cl4O2·3C6H15N, the asymmetric part of the unit cell comprises two halves of the diol mol­ecules, 2,2′′-bis­(2,7-di­chloro-9-hy­droxy-9H-fluoren-9-yl)-1,1′:4′,1′′-terphenyl, and three mol­ecules of tri­ethyl­amine, i. e. the diol mol­ecules are located on crystallographic symmetry centres. Two of the solvent mol­ecules are disordered over two positions [occupancy ratios of 0.567 (3):0.433 (3) and 0.503 (3):0.497 (3)]. In the diol mol­ecules, the outer rings of the 1,1′:4′,1′′-terphenyl elements are twisted with reference to their central arene ring and the mean planes of the fluorenyl moieties are inclined with respect to the terphenyl ring to which they are connected, the latter making dihedral angles of 82.05 (8) and 82.28 (8)°. The presence of two 9-fluoren-9-ol units attached at positions 2 and 2′′ of the terphenyl moiety induces a ‘folded’ geometry which is stabilized by intra­molecular C—H⋯O hydrogen bonds and π–π stacking inter­actions, the latter formed between the fluorenyl units and the central ring of the terphenyl unit [centroid–centroid distances = 3.559 (1) and 3.562 (1) Å]. The crystal is composed of 1:2 complex units, in which the solvent mol­ecules are associated with the diol mol­ecules via O—H⋯N hydrogen bonds, while the remaining solvent mol­ecule is linked to the host by a C—H⋯N hydrogen bond. The given pattern of inter­molecular inter­actions results in formation of chain structures extending along [010]. PMID:26870400

  5. Microbial utilization of toxic chemicals in surface waters of Guayanilla Bay, Puerto Rico: Impact of seasonal variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted on the industrial area waters of Guayanilla Bay to determine the potential for microbial utilization of toxic compounds such as fluorene, naphthalene, phenanthrene, phenol and pentachlorophenol (PCP) as a sole carbon source. Utilization of toxic substrates was determined by usi...

  6. Enhanced Performance of Inverted Polymer Solar Cells by Combining ZnO Nanoparticles and Poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyfluorene)] as Electron Transport Layer.

    PubMed

    Han, Changfeng; Cheng, Yuanyuan; Chen, Ling; Qian, Lei; Yang, Ziyan; Xue, Wei; Zhang, Ting; Yang, Yixing; Cao, Weiran

    2016-02-10

    A highly efficient inverted polymer solar cell (PSC) has been successfully demonstrated by using a ZnO nanoparticle (NP) and poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyfluorene)] (PFN) bilayer structure as an effective electron collecting layer. This ZnO/PFN bilayer structure is designed to combine the advantages of both ZnO and PFN, based on the performance comparison of ZnO-only, PFN-only, and ZnO/PFN bilayer devices in our work. ZnO NPs can serve as an efficient electron transport and buffer layer for reduced series resistance, while the PFN interlayer can improve the energy level alignment of devices through the formation of an interfacial dipole. With the enhanced electron extraction induced by the ZnO/PFN bilayer structure and PTB7:ICBA:PC71BM ternary system, the corresponding inverted PSC device shows a high PCE of 9.3%, which is more than a 15% improvement compared to the ZnO- or PFN-only devices.

  7. 2-Amino-4-phenyl-5,6-dihydro-benzo[h]quinoline-3-carbonitrile-3-amino-1-phenyl-9,10-dihydro-phenanthrene-2,4-dicarbonitrile (5/3).

    PubMed

    Asiri, Abdullah M; Al-Youbi, Abdulrahman O; Faidallah, Hassan M; Ng, Seik Weng

    2011-11-01

    The asymmetric unit of the 5:3 title co-crystal of 2-amino-4-phenyl-5,6-dihydro-benzo[h]quinoline-3-carbonitrile and 3-amino-1-phenyl-9,10-dihydro-phenanthrene-2,4-dicarbonitrile, 0.625C(20)H(15)N(3).0.375C(22)H(15)N(3), has the atoms of the fused-ring system and those of the amino, cyano and phenyl substitutents overlapped. The fused-ring system is buckled owing to the ethyl-ene linkage in the central ring, the two flanking aromatic rings being twisted by 20.1 (1)°. This ethyl-ene portion is disordered over two positions in a 1:1 ratio. The phenyl ring is twisted by 69.5 (1)° relative to the amino- and cyano-bearing aromatic ring. In the crystal, two mol-ecules are linked by an N-H⋯N hydrogen bond, generating a a helical chain along [010]. PMID:22219912

  8. Dissipation of phenanthrene and pyrene at the aerobic-anaerobic soil interface: differentiation induced by the rhizosphere of PAH-tolerant and PAH-sensitive rice (Oryza sativa L.) cultivars.

    PubMed

    He, Yan; Xia, Wen; Li, Xinfeng; Lin, Jiajiang; Wu, Jianjun; Xu, Jianming

    2015-03-01

    A pot experiment was conducted to reveal the removal of two polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, PHE, and pyrene, PYR) during rice cultivation in a paddy field. The rhizosphere effect on facilitating dissipation of PAHs varied simultaneously as a function of soil properties, PAH types, cultivation time, and genotypes within rice cultivars, with differences performed for PYR but not PHE. Changes in soil PLFA profiles evidenced that the growth of rice roots modified the dominant species within rhizosphere microbial communities and induced a selective enrichment of Gram-negative aerobic bacteria capable of degrading, thereby resulting in the differentiated dissipation of PYR. While the insignificant differences in PHE dissipation might be attributed to its higher solubility and availability under flooded condition that concealed the differences in improvement of bioavailability for microorganisms between rhizosphere and non-rhizosphere, and between both soils and both rice cultivars. Our findings illustrate that the removal of PAHs in paddy soils was more complex relative to those in dryland soils. This was possibly due to the specialty of rice roots for oxygen secretion that provides development of redox heterogeneous microbial habitats at root-soil interface under flooded condition.

  9. Essential structure of opioid κ receptor agonist nalfurafine for binding to the κ receptor 3: synthesis of decahydro(iminoethano)phenanthrene derivatives with an oxygen functionality at the 3-position and their pharmacologies.

    PubMed

    Fujii, Hideaki; Imaide, Satomi; Hirayama, Shigeto; Nemoto, Toru; Gouda, Hiroaki; Hirono, Shuichi; Nagase, Hiroshi

    2012-12-15

    To clarify the essential structures of an opioid κ receptor selective agonist, nalfurafine, for binding to the κ receptor, we designed and synthesized the decahydro(iminoethano)phenanthrene derivatives with an oxygen functionality at the 3-position. The introduction of a hydroxy group to the derivatives increased the affinity and selectivity to the κ receptor regardless of the configuration at the 3-position. However, their affinities were lower than those of nalfurafine with the phenolic hydroxy group. The results suggested that the acidity of the hydroxy group would play an important role in the interaction with the opioid receptor. The low affinities of the 3-keto derivatives indicated that the 3-hydroxy group may participate in the hydrogen bonding with the receptor site not as a hydrogen acceptor but as a hydrogen donor. This is the first experimental evidence for a role as a hydrogen donor for the 3-hydroxy group in morphinans. Furthermore, the κ selectivities in these derivatives with the 6α-amide side chain were affected by the the 3-hydroxy group. The obtained structure-activity relationship information is expected to be useful for the design of more selective ligands for the κ receptor.

  10. Characterization of Cu(II) and Cd(II) resistance mechanisms in Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and their potential application in the bioremediation of heavy metal-phenanthrene co-contaminated sites.

    PubMed

    Chen, Chen; Lei, Wenrui; Lu, Min; Zhang, Jianan; Zhang, Zhou; Luo, Chunling; Chen, Yahua; Hong, Qing; Shen, Zhenguo

    2016-04-01

    Soil that is co-contaminated with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) is difficult to bioremediate due to the ability of toxic metals to inhibit PAH degradation by bacteria. We demonstrated the resistance mechanisms to Cu(II) and Cd(II) of two newly isolated strains of Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and further tested their potential application in the bioremediation of HM-phenanthrene (PhA) co-contaminated sites. The PHE-SPH and PHE-OCH strains tolerated 4.63 and 4.34 mM Cu(II) and also showed tolerance to 0.48 and 1.52 mM Cd(II), respectively. Diverse resistance patterns were detected between the two strains. In PHE-OCH cells, the maximum accumulation of Cu(II) occurred in the cell wall, while the maximum accumulation was in the cytoplasm of PHE-SPH cells. This resulted in a sudden suppression of growth in PHE-OCH and a gradual inhibition in PHE-SPH as the concentration of Cu(II) increased. Organic acid production was markedly higher in PHE-OCH than in PHE-SPH, which may also have a role in the resistance mechanisms, and contributes to the higher Cd(II) tolerance of PHE-OCH. The factors involved in the absorption of Cu(II) or Cd(II) in PHE-SPH and PHE-OCH were identified as proteins and carbohydrates by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, both strains showed the ability to efficiently degrade PhA and maintained this high degradation efficiency under HM stress. The high tolerance to HMs and the PhA degradation capacity make Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH excellent candidate organisms for the bioremediation of HM-PhA co-contaminated sites.

  11. The historical residue trend of chlorinated hydrocarbons in the Agassiz Ice Cap, Ellesmere I., Canada

    SciTech Connect

    Gregor, D.J.; Peters, A.J.; Backus, S.; Fisher, D.; Zheng, J.

    1995-12-31

    Current detailed measurements of contaminant deposition can not provide a historical perspective except through long term monitoring programs. In the Arctic, ice caps provide an alternative to lake sediments in that the annual snow layers reflect the atmospheric deposition. As a result of the remoteness of the Agassiz Ice Cap (80{degree}49`50``N, 72{degree}56`30``W) and the limited summer melt, annual layers undergo little chemical change, especially after the first summer season, and therefore provide a well defined historical record. PCBs were first measured above detection limit in the core in the late 1950`s. Mean concentration of {Sigma}PCB over the thirty year period is 3.5 ({+-}1.3) ng. L{sup {minus}1}. {Sigma}PCB is dominated by the lower chlorinated congeners with only infrequent detections of congeners with eight or more chlorines. Deposition peaked at 930 ng.m{sup {minus}2}.a{sup {minus}1} in 1967/68 and decreased to 90 ng.m{sup {minus}2}.a{sup {minus}1} in 1980/81. Since 1980/81, deposition has again increased to a local maximum of 850 ng.m{sup {minus}2}.a{sup {minus}1} in 1989/90. PAHs are detectable throughout the sampling period. Only 7 individual PAHs were above the quantification limits including naphthalene (accounting for an overall mean of 88% of the {Sigma}PAH) acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene. No PAHs with five or more aromatic rings were observed to be present above the detection limits. The flux of PAHs to the Ice Cap remained relatively constant from 1790 to 1940 at approximately 3 {micro}g.m{sup {minus}2}.a{sup {minus}1}. The period 1940 to 1980 is dominated by a large increase in deposition peaking at 70 {micro}g.m{sup {minus}2}.a{sup {minus}1} in the early 1970`s. The final period, 1980 to 1993 shows a steady increase by a factor of about 2 from a minimum of 10--20 {micro}g.m{sup {minus}2}.a{sup {minus}1}.

  12. [Identification of the characteristic vibrations for 16 PAHs based on Raman spectrum].

    PubMed

    Zeng, Ya-Ling; Jiang, Long; Cai, Xiao-Yu; Li, Yu

    2014-11-01

    In the present paper, by means of density functional theory in B3LYP/6-311++G(d, p) method, 16 kinds of pollutants, i. e. polycyclic aromatic hydrocarbons (PAHs): naphthalene (Nap), acenaphthylene (AcPy), acenaphthene (Acp), fluorene (Flu), phenanthrene (PA), anthracene (Ant), fluoranthene (Fl), pyrene (Pyr), benzo [a] anthracene (BaA), fused two naphthalene (CHR), benzo [b] fluoranthene (BbF), benzo [k] fluoranthene (BkF), benzo [a] pyrene (BaP), dibenzo (a, h) anthracene (DahA), dibenzo [g, h, i] pyrene (BghiP) and indene benzene (1, 2, 3-cd) pyrene (IcdP) among the U. S. EPA priority pollutants were selected, whose structures were optimized and Raman vibrational frequencies and depolarization were calculated. The structure, Raman vibrational frequencies and depolarization were basis of identification of PAHs. Studies have shown that Raman vibrations of 16 PAHs are mainly distributed in three frequency regions: 200-1 000 cm(-1) (fingerprint region), 1 000-1 700 cm(-1) and 3 000-3 200 cm(-1) (group frequency region), corresponding vibrations were assigned to ring deformation (ring def), C-C stretching (CCStr), C-H wiggle (CHw) and of these two patterns (CCStrCCw), and C-H stretching (CHStr). Further analysis showed that in fingerprint region the depolarization of 16 PAHs was reduced with the symmetry of benzene deformation vibration enhanced. At the point of minimum depolarization, symmetry and Raman peak of benzene ring breathing vibration were found strongest. At the minimum differential wave number the strongest peak in fingerprint region was distinguishable by micro-Raman spectroscopy. Therefore, 16 PAHs can be individually identified by depolarization and the strongest peak in fringerprint region. Vibration frequencies and peak intensity distribution of alkanes (Akn), olefin (Oe), alkyne (Aye), alcohols and phenols (Aap), aliphatic ether (Ape), arylalkyl ether (Aae), aldehydes (Ahd), ketones (Ktn), carboxylic acid (Cba), esters (Etr), amines (Aie), nitriles

  13. Mutagenicity, Stable DNA Adducts, and Abasic Sites Induced in Salmonella by Phenanthro[3,4-b]- and Phenanthro[4,3-b]thiophenes, Sulfur Analogs of Benzo[c]phenanthrene

    PubMed Central

    Swartz, Carol D.; King, Leon C.; Nesnow, Stephen; Umbach, David M.; Kumar, Subodh; DeMarini, David M.

    2009-01-01

    Sulfur-containing polycyclic aromatic hydrocarbons (thia-PAHs or thiaarenes) are common constituents of air pollution and cigarette smoke, but only a few have been studied for health effects. We evaluated the mutagenicity in Salmonella TA98, TA100, and TA104 of two sulfur-containing derivatives of benzo[c]phenanthrene, phenanthro[3,4-b]thiophene (P[3,4-b]T), and phenanthro[4,3-b]thiophene (P[4,3-b]T) as well as their dihydrodiol and sulfone derivatives. In addition, we assessed levels of stable DNA adducts (by 32P-postlabeling) as well as abasic sites (by an aldehydic-site assay) produced by six of these compounds in TA100. P[3,4-b]T and its 6,7- and 8,9-diols, P[3,4-b]T sulfone, P[4,3-b]T, and its 8,9-diol were mutagenic in TA100. P[3,4-b]T sulfone, the most potent mutagen, was approximately twice as potent as benzo[a]pyrene in both TA98 and TA100. Benzo-ring dihydrodiols were much more potent than K-region dihydrodiols, which had little or no mutagenic activity in any strain. P[3,4-b]T sulfone produced abasic sites and not stable DNA adducts; the other five compounds examined, B[c]P, B[c]P 3,4-diol, P[3,4-b]T, P[3,4-b]T 8,9-diol, and P[4,3-b]T 8,9-diol, produced only stable DNA adducts. P[3,4-b]T sulfone was the only compound that produced significant levels of frameshift mutagenicity and induced mutations primarily at GC sites. In contrast, B[c]P, its 3,4-diol, and the 8,9 diols of the phenanthrothiophenes induced mutations primarily at AT sites. P[3,4-b]T was not mutagenic in TA104, whereas P[3,4-b]T sulfone was. The two isomeric forms (P[3,4-b]T and P[4,3-b]T) are apparently activated differently, with the latter, but not the former, involving a diol pathway. This study is the first illustrating the potential importance of abasic sites in the mutagenicity of thia-PAHs. PMID:19041882

  14. Analysis of Phenanthrene and Benzo[a]pyrene Tetraol Enantiomers in Human Urine: Relevance to the Bay Region Diol Epoxide Hypothesis of Benzo[a]pyrene Carcinogenesis and to Biomarker Studies

    PubMed Central

    Hecht, Stephen S.; Carmella, Steven G.; Villalta, Peter W.; Hochalter, J. Bradley

    2010-01-01

    One widely accepted metabolic activation pathway of the prototypic carcinogenic polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP) proceeds through the “bay region diol epoxide” BaP-(7R,8S)-diol-(9S,10R)-epoxide (2). However, few studies have addressed the analysis of human urinary metabolites of BaP which result from this pathway. Phenanthrene (Phe) is structurally related to BaP, but human exposure to Phe is far greater and its metabolites can be readily detected in urine. Thus, Phe metabolites have been proposed as biomarkers of PAH exposure and metabolic activation. Phe-tetraols in particular could be biomarkers of the diol epoxide pathway. While BaP-tetraols and Phe-tetraols have been previously quantified in human urine, no published studies have determined their enantiomeric composition. This is important because different enantiomers would result from the bay region diol epoxide and “reverse” diol epoxide pathways, the latter being associated with weak mutagenicity and carcinogenicity. We addressed this problem using chiral HPLC to separate the enantiomers of BaP-7,8,9,10-tetraol and Phe-1,2,3,4-tetraol. Urine samples from smokers were subjected to solid-phase extraction, chiral HPLC, and GC-NICI-MS/MS analysis for silylated Phe-1,2,2,4-tetraols. The results demonstrated that >96% of Phe-1,2,3,4-tetraol in smokers’ urine was Phe-(1S,2R,3S,4R)-tetraol (12), resulting from the “reverse” diol epoxide pathway, whereas less than 4% resulted from the “bay region diol epoxide” pathway of Phe metabolism. Urine from creosote workers was similarly analyzed for BaP-7,8,9,10-tetraol enantiomers. In contrast to the results of the Phe-tetraol analyses, 78% of BaP-7,8,9,10-tetraol in these human urine samples was BaP-(7R,8S,9R,10S)-tetraol (3) resulting from the “bay region diol epoxide” pathway of BaP metabolism. These results provide further support for the bay region diol epoxide pathway of BaP metabolism in humans and demonstrate

  15. Effect of injection of di- and tricyclic aromatic compounds on post-combustion formation of polychlorinated dibenzo-p-dioxins and dibenzofurans.

    PubMed

    Jansson, Stina; Fick, Jerker; Tysklind, Mats

    2011-08-15

    The formation of mono- to octachlorinated dibenzo-p-dioxins (PC₁₋₈DD) and dibenzofurans (PC₁₋₈DF) was studied using a model waste in a laboratory-scale combustion reactor with simultaneous collection of flue gas at three different temperatures (450 °C, 300 °C, and 200 °C) in the post-combustion zone. To investigate the influence of chlorination reactions and the effects of carbon backbone-containing compounds present in the flue gases, five aromatic compounds were injected into the flue gas, namely dibenzofuran (DF), biphenyl (BP), naphthalene, phenanthrene and fluorene. The injection of DF induced a reduction in the concentration of PC₃₋₅DD, but did not significantly influence the concentration of PCDF. A reduction in the concentration of PC₃₋₅DD was also observed during the injection of fluorene, which is structurally very similar to DF. The injection of biphenyl, naphthalene and phenanthrene had less pronounced effects on the formation of PCDD and PCDF. A possible explanation of the observed changes during injection of DF and fluorene, based on homologue profiles and affected congeners, involves formation of radical species from fluorene and/or dibenzofuran. The fluorene radical is stabilized by the delocalization of electrons across the aromatic ring structure and has the propensity to react with highly abundant hydrogen chloride, whereas the molecular species would require reaction with Cl₂ or chlorine radicals.

  16. Effects of two novel D3-selective compounds, NGB 2904 [N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-9H-fluorene-2-carboxamide] and CJB 090 [N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide], on the reinforcing and discriminative stimulus effects of cocaine in rhesus monkeys.

    PubMed

    Martelle, Jennifer L; Claytor, Renee; Ross, Jason T; Reboussin, Beth A; Newman, Amy Hauck; Nader, Michael A

    2007-05-01

    The present study examined the effects of two novel dopamine D3 receptor compounds, NGB 2904 [N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-9H-fluorene-2-carboxamide], an antagonist, and CJB 090 [N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide], a partial agonist, in two models of cocaine abuse in rhesus monkeys. To establish a dose range and time course of effects, both compounds were shown to block quinpirole-induced yawning when administered i.m. 15, 30, or 120 min before quinpirole. Next, rhesus monkeys were trained to discriminate i.m. injections of saline (0.5 ml) and cocaine (0.3 mg/kg). Neither D3 compound (0.03-3.0 mg/kg; n=3) substituted for cocaine in any monkey. When given in combination with cocaine, CJB 090 but not NGB 2904 attenuated the discriminative stimulus effects of cocaine, shifting the cocaine dose-response curve to the right. In a separate group of monkeys, responding was maintained under a second-order schedule of either food (1.0-g pellets; n=3) or cocaine (0.1 mg/kg/injection; n=4) presentation. When responding was stable, a dose of NGB 2904 (1.0-5.6 mg/kg i.v.) or CJB 090 (0.3-3.0 mg/kg i.v.) was administered for 5 consecutive days, immediately before the session. CJB 090, but not NGB 2904, decreased cocaine- and food-maintained responding. These data indicate that compounds with relatively high affinity and selectivity for the D3 receptor can attenuate the discriminative and reinforcing stimulus effects of cocaine while not producing cocaine-like effects. The present findings support the continued examination of D3 compounds as pharmacological tools for better understanding the role of this receptor subtype in cocaine addiction and as potential lead compounds for novel therapeutic agents. PMID:17272677

  17. Urinary Biomarkers of Polycyclic Aromatic Hydrocarbons Are Associated with Cardiometabolic Health Risk

    PubMed Central

    Ranjbar, Mahsa; Rotondi, Michael A.; Ardern, Chris I.; Kuk, Jennifer L.

    2015-01-01

    Background Polycyclic aromatic hydrocarbons (PAH) are both man-made and naturally occurring environmental pollutants that may be related to cardiometabolic health risk. Objective To determine whether PAH is associated with obesity in the adult population and to examine whether urinary concentrations of PAH metabolites are associated with differences in how obesity relates to 3 or more risk factors for the metabolic syndrome (3RFMetS), type 2 diabetes (T2D), hypertension, and dyslipidemia. Methods A total of 4765 adult participants from the 2001–2008 National Health and Nutrition Examination Survey were examined. The association between 8 urinary hydroxylated PAH metabolites, obesity, and health were examined using weighted logistic regressions adjusting for age, sex, ethnicity, PIR, smoking status, and urinary creatinine. Results There was a positive dose-dependent association between obesity and 2-phenanthrene quintiles (P trend <0.0001). Contrarily, higher quintiles of 1-naphthalene were associated with lower risk of obesity (P trend = 0.0004). For a given BMI, those in the highest quintile of 2-naphthalene, 2-fluorene, 3-fluorene and 2-phenanthrene had a 66–80% greater likelihood of 3RFMetS (P≤0.05) compared to low levels. Higher quintiles of 1-naphthalene, 2-naphthalene, 2-phenanthrene and 1-pyrene were associated with a 78–124% greater likelihood of T2D (P≤0.05) compared to low levels while high 1-naphthalene, 2-naphthalene, 2-fluorene, 3-fluorene and 2-phenanthrene were associated with a 38–68% greater likelihood of dyslipidemia (P≤0.05) compared to lower levels. Finally, 2-naphthalene and 2-phenanthrene were positively associated with hypertension (P trend = 0.008 and P trend = 0.02 respectively). Conclusions PAH is related to obesity and the expression of a number of obesity-related cardiometabolic health risk factors. Future research is needed to bring to light the mechanistic pathways related to these findings. PMID:26340343

  18. 9,10-Dibromo­phenanthrene

    PubMed Central

    Yokota, Ruri; Kitamura, Chitoshi; Kawase, Takeshi

    2012-01-01

    The mol­ecule of the title compound, C14H8Br2, is almost planar [maximum deviation 0.0355 (7) Å] and possesses crystallographic twofold (C2) symmetry. In the crystal, the mol­ecules form face-to-face slipped anti­parallel π–π stacking inter­actions along the c axis with an inter­planar distance 3.471 (7) Å, centroid–centroid distances of 3.617 (5)–3.803 (6) Å. PMID:23284487

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

    PubMed

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

    2015-01-01

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

  20. Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Bacteria Isolated from Light Oil Polluted Soils

    NASA Astrophysics Data System (ADS)

    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.

  1. Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

    PubMed

    Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

    2016-10-01

    The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry. PMID:27391049

  2. Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

    PubMed

    Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

    2016-10-01

    The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry.

  3. Analysis of a workplace air particulate sample by synchronous luminescence and room-temperature phosphorescence

    SciTech Connect

    Vo-Dinh, T.; Gammage, R.B.; Martinez, P.R.

    1981-02-01

    An analysis of a XAD-2 resin extract of a particulate air sample collected at an industrial environment was conducted by use of two simple spectroscopic methods performed at ambient temperature, the synchronous luminescence and room-temperature phosphorescence techniques. Results of the analysis of 13 polynuclear aromatic compounds including anthracene, benzo(a)pyrene, benzo(e)pyrene, 2,3-benzofluorene, chrysene, 1,2,5,6-dibenzanthracene, dibenzthiophene, fluoranthene, fluorene, phenanthrene, perylene, pyrene, and tetracene were reported.

  4. The use of CNDO in spectroscopy. XV. Two photon absorption

    NASA Astrophysics Data System (ADS)

    Marchese, Francis T.; Seliskar, C. J.; Jaffé, H. H.

    1980-04-01

    Two-photon absorptivities have been calculated within the CNDO/S-CI molecular orbital framework of Del Bene and Jaffé utilizing the second order time dependent perturbation equations of Göppert-Mayer and polarization methods of McClain. Good agreement is found between this theory and experiment for transition energies, symmetries, and two-photon absorptivities for the following molecules: biphenyl, terphenyl, 2,2'-difluorobiphenyl, 2,2'-bipyridyl, phenanthrene, and the isoelectronic series: fluorene, carbazole, dibenzofuran.

  5. Implications of treating water containing polynuclear aromatic hydrocarbons with chlorine: a gas chromatographic-mass spectrometric study.

    PubMed Central

    Oyler, A R; Liukkonen, R J; Lukasewycz, M K; Cox, D A; Peake, D A; Carlson, R M

    1982-01-01

    The products of aqueous chlorination reactions of 1-methylnaphthalene, fluorene, dibenzofuran, anthracene, phenanthrene, 1-methylphenanthrene, fluoranthene, and pyrene have been determined. The conditions employed for these reactions approximated those that might be encountered in water treatment facilities. Reactions at pH greater than 6 tended to produce oxygenated products (epoxides, phenols, quinones, etc.), and reactions at pH less than 6 tended to produce both oxygenated (quinones) and chlorinated products. PMID:7151769

  6. Toxicity and photoactivation of PAH mixtures in marine sediment

    SciTech Connect

    Swartz, R.; Ferraro, S.; Lamberson, J.; Cole, F.; Ozretich, R.; Boese, B.; Schults, D.; Behrenfeld, M.; Ankley, G.

    1995-12-31

    The toxicity and toxicological photoactivation of mixtures of sediment-associated fluoranthene, phenanthrene, pyrene, and acenaphthene were determined using standard 10 d sediment toxicity tests with the marine amphipod, Rhepoxynius abronius. The four PAHs were spiked into sediment in a concentration series of either single compounds or an equitoxic mixture. Spiked sediment was stored at 4 C for 28 d before testing. Toxicity tests were conducted under fluorescent lighting. Survivors after 10 d in PAH-contaminated sediment were exposed for 1 h to UV light in the absence of sediment and then tested for their ability to bury in clean sediment. The 10 d LC50s for single PAHs were 3.3, 2.2, 2.8, and 2.3 mg/g oc for fluoranthene, phenanthrene, pyrene, and acenaphthene, respectively. These LC50s were used to calculate the sum of toxic units ({Sigma}TU) of the four PAHs in the equitoxic mixture treatments. The {Sigma}TU LC50 was then calculated for the mixture treatments. If the toxicological interaction of the four PAHs in the mixture was additive, the {Sigma}TU LC50 should equal 1.0. The observed {Sigma}TU LC50 in the mixture was 1.55, indicating the interaction was slightly less than additive. UV enhancement of toxic effects of individual PAHs was correctly predicted by photophysical properties, i.e. pyrene and fluoranthene were photoactivated and phenanthrene and acenaphthene were not. UV effects in the mixture of four PAHs can be explained by the photoactivation of pyrene and fluoranthene alone.

  7. Photoactivation and toxicity of mixtures of polycyclic aromatic hydrocarbon compounds in marine sediment

    SciTech Connect

    Swartz, R.C.; Ferraro, S.P.; Lamberson, J.O.; Cole, F.A.; Ozretich, R.J.; Boese, B.L.; Schults, D.W.; Behrenfeld, M.; Ankley, G.T.

    1997-10-01

    The direct toxicity and photoinduced toxicity of sediment-associated acenaphthene, phenanthrene, fluoranthene, and pyrene were determined for the marine amphipod Rhepoxynius abronius. The four polycyclic aromatic hydrocarbons (PAHs) were spiked into sediment in a concentration series of either single compounds or as approximately equitoxic mixtures of all four compounds. Standard 10-d sediment toxicity tests were conducted under fluorescent lighting. After 10 d, survivors were exposed for 1 h to ultraviolet (UV) radiation in the absence of sediment and then tested for their ability to bury in uncontaminated sediment. The 10-d median lethal concentrations (LC50s) were 2.31 mg acenaphthene/g organic carbon (OC), 2.22 mg phenanthrene/g OC, 3.31 mg fluoranthene/g OC, and 2.81 mg pyrene/g OC. These LC50s were used to calculate the sum of toxic units ({Sigma}TU) of the four PAHs in the approximately equitoxic mixtures. The {Sigma}TU LC50 was then calculated for the mixture treatments. If the toxicologic interaction of a mixture of contaminants is additive, {Sigma}TU LC50 = 1.0. The observed LC50 (1.55 {Sigma}TU) was slightly, but significantly, greater than unity, indicating that the interaction of PAHs in the mixture was less than additive. Exposure to UV radiation enhanced the toxic effects of fluoranthene and pyrene, but did not affect the toxicity of acenaphthene and phenanthrene. Effects of UV radiation on the toxicity of the mixture of four PAHs could be explained by the photoactivation of fluoranthene and pyrene alone. These results are consistent with predictions based on photophysical properties of PAH compounds.

  8. Probes for narcotic receptor mediated phenomena. 46.° N-Substituted-2,3,4,9,10,10a-hexahydro-1H-1,4a-(epiminoethano)phenanthren-6- and 8-ols - carbocyclic relatives of f-oxide bridged phenylmorphans

    PubMed Central

    Li, Fuying; Deck, Jason A.; Dersch, Christina M.; Rothman, Richard B.; Deschamps, Jeffrey R.; Jacobson, Arthur E.; Rice, Kenner C.

    2012-01-01

    Oxide-bridged phenylmorphans were conceptualized as topologically distinct, structurally rigid ligands with 3-dimensional shapes that could not be appreciably modified on interaction with opioid receptors. An enantiomer of the N-phenethyl-substituted ortho-f isomer was found to have high affinity for the μ-receptor (Ki = 7 nM) and was about four times more potent than naloxone as an antagonist. In order to examine the effect of introduction of a small amount of flexibility into these molecules, we have replaced the rigid 5-membered oxide ring with a more flexible 6-membered carbon ring. Synthesis of the new N-phenethyl-substituted tricyclic N-substituted-2,3,4,9,10,10a-hexahydro-1H-1,4a-(epiminoethano)phenanthren-6- and 8-ols resulted in a two carbon-bridged relative of the f-isomers, the dihydrofuran ring was replaced by a cyclohexene ring. The carbocyclic compounds had much higher affinity and greater selectivity for the μ-receptor than the f-oxide-bridged phenylmorphans. They were also much more potent μ-antagonists, with activities comparable to naltrexone in the [35S]GTPγS assay. PMID:23168379

  9. 2-Amino-4-(3,4-dimeth-oxy-phen-yl)-5,6-dihydro-benzo[h]quinoline-3-carbo-nitrile-3-amino-1-(3,4-dimeth-oxy-phen-yl)-9,10-dihydro-phenanthrene-2,4-dicarbonitrile (1/19).

    PubMed

    Asiri, Abdullah M; Al-Youbi, Abdulrahman O; Faidallah, Hassan M; Ng, Seik Weng

    2011-11-01

    The asymmetric unit of the 1:19 title co-crystal of 2-amino-4-(3,4-dimeth-oxy-phen-yl)-5,6-dihydro-benzo[h]quinoline-3-carbo-nitrile and 3-amino-1-(3,4-dimeth-oxy-phen-yl)-9,10-dihydro-phenanthrene-2,4-dicarbonitrile, 0.05C(22)H(19)N(3)O(2)·0.95C(24)H(19)N(3)O(2), has the atoms of the fused-ring system and those of the amino, cyano and dimeth-oxy-phenyl substitutents overlapped. The fused-ring system is buckled owing to the ethyl-ene linkage in the central ring with the two flanking aromatic rings being twisted by 31.9 (1)°. The ring of the dimeth-oxy-phenyl substituent is twisted by 72.4 (1)° relative to the amino- and cyano-bearing aromatic ring. In the crystal, mol-ecules are linked by duplex amine N-H⋯O(meth-oxy) hydrogen bonds in a cyclic association [graph-set R(2) (2)(7)], generating a helical chain structure extending along [201]. PMID:22219913

  10. 2-Amino-4-(4-chloro-phen-yl)-5,6-dihydro-benzo[h]quinoline-3-carbonitrile-3-amino-1-(4-chloro-phen-yl)-9,10-dihydro-phenanthrene-2,4-dicarbonitrile (1/4).

    PubMed

    Asiri, Abdullah M; Al-Youbi, Abdulrahman O; Faidallah, Hassan M; Ng, Seik Weng

    2011-11-01

    The asymmetric unit of the 1:4 title co-crystal of 2-amino-4-(4-chloro-phen-yl)-5,6-dihydro-benzo[h]quinoline-3-carbonitrile and 3-amino-1-(4-chloro-phen-yl)-9,10-dihydro-phenanthrene-2,4-dicarbonitrile, 0.2C(20)H(14)ClN(3)·0.8C(22)H(14)ClN(3), has the atoms of the fused-ring system and those of the amino, cyano and chloro-phenyl substitutents overlapped. The fused-ring system is buckled owing to the ethyl-ene linkage in the central ring. There are two independent overlapped mol-ecules in the asymmetric unit. In one independent mol-ecule, the two flanking aromatic rings are twisted by 24.4 (1)° and the ring of the chloro-phenyl substituent is twisted by 87.3 (1)° relative to the amino- and cyano-bearing aromatic ring. In the second mol-ecule, the respective dihedral angles are 26.1 (1) and 57.8 (1)°. The two independent mol-ecules are linked by N-H⋯N hydrogen bonds into dimers. PMID:22219914

  11. Reference range levels of polycyclic aromatic hydrocarbons in the US population by measurement of urinary monohydroxy metabolites

    SciTech Connect

    Grainger, James . E-mail: jag2@cdc.gov; Huang, Wenlin; Patterson, Donald G.; Turner, Wayman E.; Pirkle, James; Caudill, Samuel P.; Wang, Richard Y.; Needham, Larry L.; Sampson, Eric J.

    2006-03-15

    We developed a gas chromatography isotope-dilution high-resolution mass spectrometry (GC/Id-HRMS) method for measuring 14 polycyclic aromatic hydrocarbon (PAH) metabolites representing seven parent PAHs in 3 mL of urine at low parts-per-trillion levels. PAH levels were determined in urine samples collected in 1999 and 2000 from approximately 2400 participants in the National Health and Nutrition Examination Survey, and, for the first time, reference range values were calculated for these metabolites in the US population. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of fluorene, phenanthrene, fluoranthene, pyrene, and chrysene, benzo[c]phenanthrene, and benz[a]anthracene. Some monohydroxy metabolite isomers of benzo[c]phenanthrene, chrysene, and benz[a]anthracene exhibited low detection frequencies that did not allow for geometric mean calculations. Our study results enabled us to establish a reference range for the targeted PAHs in the general US population.

  12. Passive dosing versus solvent spiking for controlling and maintaining hydrophobic organic compound exposure in the Microtox® assay.

    PubMed

    Smith, Kilian E C; Jeong, Yoonah; Kim, Jongwoon

    2015-11-01

    Microbial toxicity bioassays such as the Microtox® test are ubiquitously applied to measure the toxicity of chemicals and environmental samples. In many ways their operation is conducive to the testing of organic chemicals. They are of short duration, use glass cuvettes and take place at reduced temperatures in medium lacking sorbing components. All of these are expected to reduce sorptive and volatile losses, but particularly for hydrophobic organics the role of such losses in determining the bioassay response remains unclear. This study determined the response of the Microtox® test when using solvent spiking compared to passive dosing for introducing the model hydrophobic compounds acenaphthene, phenanthrene, fluoranthene and benzo(a)pyrene. Compared to solvent spiking, the apparent sensitivity of the Microtox® test with passive dosing was 3.4 and 12.4 times higher for acenaphthene and phenanthrene, respectively. Furthermore, fluoranthene only gave a consistent response with passive dosing. Benzo(a)pyrene did not result in a response with either spiking or passive dosing even at aqueous solubility. Such differences in the apparent sensitivity of the Microtox® test can be traced back to the precise definition of the dissolved exposure concentrations and the buffering of losses with passive dosing. This highlights the importance of exposure control even in simple and short-term microbial bioassays such as the Microtox® test. PMID:26117202

  13. Evaluation of the reaction artifacts in an annular denuder-based sampler resulting from the heterogeneous ozonolysis of naphthalene.

    PubMed

    Goriaux, Mathieu; Pflieger, Maryline; Monod, Anne; Gligorovski, Sasho; Strekowski, Rafal S; Wortham, Henri

    2014-04-01

    The heterogeneous ozonolysis of naphthalene adsorbed on XAD-4 resin was studied using an annular denuder technique. The experiments involved depositing a known quantity of naphthalene on the XAD-4 resin and then measuring the quantity of the solid naphthalene that reacted away under a constant flow of gaseous ozone (0.064 to 4.9 ppm) for a defined amount of time. All experiments were performed at room temperature (26 to 30 °C) and atmospheric pressure. The kinetic rate coefficient for the ozonolysis reaction of naphthalene adsorbed on XAD-4 resin is reported to be (10.1 ± 0.4) × 10(-19) cm(3) molecule(-1) s(-1) (error is 2σ, precision only). This value is five times greater than the currently recommended literature value for the homogeneous gas phase reaction of naphthalene with ozone. The obtained rate coefficient is used to evaluate reaction artifacts from field concentration measurements of naphthalene, acenaphthene, and phenanthrene. The observed uncertainties associated with field concentration measurements of naphthalene, acenaphthene, and phenanthrene are reported to be much higher than the uncertainties associated with the artifact reactions. Consequently, ozone reaction artifact appears to be negligible compared to the observed field measurement uncertainty results.

  14. Amelioration of soil PAH and heavy metals by combined application of fly ash and biochar

    NASA Astrophysics Data System (ADS)

    Masto, Reginald; George, Joshy; Ansari, Md; Ram, Lal

    2016-04-01

    Generation of electricity through coal combustion produces huge quantities of fly ash. Sustainable disposal and utilization of these fly ash is a major challenge. Fly ash along with other amendments like biochar could be used for amelioration of soil. In this study, fly ash and biochar were used together for amelioration of polycyclic aromatic hydrocarbon (PAH) contaminated soil. Field experiment was conducted to investigate the effects of fly ash and biochar on the amelioration of soil PAH, and the yield of Zea mays. The treatments were control, biochar (4 t/ha), fly ash (4 t/ha), ash + biochar ( 2 + 2 t/ha). Soil samples were collected after the harvest of maize crop and analysed for chemical and biological parameters. Thirteen PAHs were analysed in the postharvest soil samples. Soil PAHs were extracted in a microwave oven at 120 °C using hexane : acetone (1:1) mixture. The extracted solutions were concentrated, cleaned and the 13 PAHs [Acenaphthene (Ace), fluorene (Flr), phenanthrene (Phn), anthracene(Ant), pyrene(Pyr), benz(a)anthracene (BaA), chrysene (Chy), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene, benzo(g,h,i)perylene (BghiP), dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene)(Inp)] were analysed using GC-MS. The mean pH increased from 6.09 in control to 6.64 and 6.58 at biochar and fly ash treated soils, respectively. N content was not affected, whereas addition of biochar alone and in combination with fly ash, has significantly increased the soil organic carbon content. P content was almost double in combined (9.06 mg/kg) treatment as compared to control (4.32 mg/kg). The increase in K due to biochar was 118%, whereas char + ash increased soil K by 64%. Soil heavy metals were decreased: Zn (-48.4%), Ni (-41.4%), Co (-36.9%), Cu (-35.7%), Mn (-34.3%), Cd (-33.2%), and Pb (-30.4%). Soil dehydrogenase activity was significantly increased by ash and biochar treatments and the maximum activity was observed for the combined

  15. Amelioration of soil PAH and heavy metals by combined application of fly ash and biochar

    NASA Astrophysics Data System (ADS)

    Masto, Reginald; George, Joshy; Ansari, Md; Ram, Lal

    2016-04-01

    Generation of electricity through coal combustion produces huge quantities of fly ash. Sustainable disposal and utilization of these fly ash is a major challenge. Fly ash along with other amendments like biochar could be used for amelioration of soil. In this study, fly ash and biochar were used together for amelioration of polycyclic aromatic hydrocarbon (PAH) contaminated soil. Field experiment was conducted to investigate the effects of fly ash and biochar on the amelioration of soil PAH, and the yield of Zea mays. The treatments were control, biochar (4 t/ha), fly ash (4 t/ha), ash + biochar ( 2 + 2 t/ha). Soil samples were collected after the harvest of maize crop and analysed for chemical and biological parameters. Thirteen PAHs were analysed in the postharvest soil samples. Soil PAHs were extracted in a microwave oven at 120 °C using hexane : acetone (1:1) mixture. The extracted solutions were concentrated, cleaned and the 13 PAHs [Acenaphthene (Ace), fluorene (Flr), phenanthrene (Phn), anthracene(Ant), pyrene(Pyr), benz(a)anthracene (BaA), chrysene (Chy), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene, benzo(g,h,i)perylene (BghiP), dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene)(Inp)] were analysed using GC-MS. The mean pH increased from 6.09 in control to 6.64 and 6.58 at biochar and fly ash treated soils, respectively. N content was not affected, whereas addition of biochar alone and in combination with fly ash, has significantly increased the soil organic carbon content. P content was almost double in combined (9.06 mg/kg) treatment as compared to control (4.32 mg/kg). The increase in K due to biochar was 118%, whereas char + ash increased soil K by 64%. Soil heavy metals were decreased: Zn (‑48.4%), Ni (‑41.4%), Co (‑36.9%), Cu (‑35.7%), Mn (‑34.3%), Cd (‑33.2%), and Pb (‑30.4%). Soil dehydrogenase activity was significantly increased by ash and biochar treatments and the maximum activity was observed for the

  16. Concentrations of polynuclear aromatic hydrocarbons and inorganic constituents in ambient surface soils, Chicago, Illinois, 2001-02

    USGS Publications Warehouse

    Kay, Robert T.; Arnold, Terri L.; Cannon, William F.; Graham, David; Morton, Eric; Bienert, Raymond

    2003-01-01

    Polynuclear aromatic hydrocarbon (PAH) compounds are ubiquitous in ambient surface soils in the city of Chicago, Illinois. PAH concentrations in samples collected in June 2001 and January 2002 were typically in the following order from highest to lowest: fluoranthene, pyrene, benzo(b)fluoranthene, phenanthrene, benzo(a)pyrene, chrysene, benzo(a)anthracene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, benzo(g,h,i)perylene, dibenzo(a,h)anthracene, and anthracene. Naphthalene, acenaphthene, acenaphthylene, and fluorene were consistently at the lowest concentrations in each sample. Concentrations of the PAH compounds showed variable correlation. Concentrations of PAH compounds with higher molecular weights typically show a higher degree of correlation with other PAH compounds of higher molecular weight, whereas PAH compounds with lower molecular weights tended to show a lower degree of correlation with all other PAH compounds. These differences indicate that high and low molecular-weight PAHs behave differentl y once released into the environment. Concentrations of individual PAH compounds in soils typically varied by at least three orders of magnitude across the city and varied by more than an order of magnitude over a distance of about 1,000 feet. Concentrations of a given PAH in ambient surface soils are affected by a variety of site-specific factors, and may be affected by proximity to industrial areas. Concentrations of a given PAH in ambient surface soils did not appear to be affected the organic carbon content of the soil, proximity to non-industrial land use, or proximity to a roadway. The concentration of the different PAH compounds in ambient surface soils appears to be affected by the propensity for the PAH compound to be in the vapor or particulate phase in the atmosphere. Lower molecular-weight PAH compounds, which are primarily in the vapor phase in the atmosphere, were detected in lower concentrations in the surface soils. Higher molecular-weight PAH

  17. [Indoor air guide values for naphthalene and naphthalene-like compounds. Announcement of the German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the States' Supreme Health Authorities].

    PubMed

    2013-10-01

    The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the States' Supreme Health Authorities is issuing indoor air guide values to protect public health. Naphthalene is a potentially volatile two-ring hydrocarbon with a mothball-like odor. Indoor air contaminations usually originate from tar-containing building products, sometimes from the use of mothballs. In Germany, indoor air concentrations of naphthalene are usually low, near the detection limit (medians of about 0.001 mg/m3, 95th percentiles up to 0.004 mg/m3). Naphthalene-like volatile compounds have been defined to cover methyl- and dimethylnaphthalenes and tricyclic aromatic hydrocarbons (e.g., acenaphthene, acenaphthylene, anthracene, fluorene and phenanthrene). Though methylnaphthalenes and dimethylnaphthalenes usually show low indoor air concentrations, they have been suspected to add to the mothball-like odor. Tricyclic aromatic hydrocarbons mostly occur below 0.001 mg/m3 of indoor air. Against this background naphthalene is seen to be the key component of this group of substances in indoor air. No valid human data is available with respect to health effects of inhaled naphthalene. Based on animal data cytotoxic-inflammatory lesions in the rat nasal epithelium are regarded as the critical endpoint. In a subchronic inhalation study in rats (Dodd et al., Inhal Toxicol 24:70–79, 2012), minimal effects were observed following an exposure to 5 mg naphthalene/m3. From this study the Ad-hoc Working Group derived a chronic NAEC of 2.5 mg naphthalene/m3. Time scaling was considered by a factor of 5.6 extrapolating from 6 to 24 h and 5 to 7 days, a factor of 2 applied for the use of F344 rats instead of the more sensitive Sprague-Dawley rats. Incorporating an interspecies factor of 1, an intraspecies factor of 10 and a factor of 2 for insufficient data on the toxicity of naphthalene in children resulted in a precautionary value of 0.01 mg naphthalene/m3 and a hazard

  18. Toxicity of polycyclic aromatic hydrocarbons to the nematode Caenorhabditis elegans.

    PubMed

    Sese, Beke T; Grant, Alastair; Reid, Brian J

    2009-01-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) in the environment has attracted much concern owing to their mutagenic and carcinogenic properties. Regulatory authorities have favored the use of biological indicators as an essential means of assessing potential toxicity of environmental pollutants. This study aimed to assess the toxicity of acenaphthene, phenanthrene, anthracene, fluoranthene, pyrene, and benzo[a]pyrene to Caenorhabditis elegans by measuring LC50 and EC50 values for growth and reproduction. The exposure to all chemicals was carried out in aqueous medium. All PAHs showed a low acute toxicity to C. elegans. There was no significant mortality in C. elegans after 24 h of exposure at PAH concentrations within (and indeed above) their respective solubility limits. Prolonged exposure (72 h) at high concentrations for acenaphthene (70,573 microg/L), phenanthrene (3758 microg/L), anthracene (1600 microg/L), fluoranthene (1955 microg/L), pyrene (1653 microg/L), and benzo[a]pyrene (80 microg/L) produced mortality. Results also showed that reproduction and growth were much more sensitive parameters of adverse response than lethality, and consequently may be more useful in assessing PAH toxicity using C. elegans. In comparison with previous studies, C. elegans was found to be approximately 2-fold less sensitive to acenaphthene, 5-fold less sensitive to phenanthrene, and 20-fold less sensitive to fluoranthene than Daphnia magna. However, the 48-h LC50 for benzo[a]pyrene (174 microg/L) reported in the present study with C. elegans was similar to that reported elsewhere for Daphnia magna (200 microg/L). Although C. elegans indicated greater sensitivity to benzo[a]pyrene than Artemia salina (174 microg/L vs. 10000 microg/L), the organism showed less sensitivity to pyrene (8 microg/L vs. 2418 microg/L), fluoranthene (40 microg/L vs. 2719 microg/L), and phenanthrene (677 microg/L vs. 4772 microg/L) than Artemia salina. Caenorhabditis elegans, while not the

  19. Biomonitoring of polycyclic aromatic hydrocarbon exposure in pregnant women in Trujillo, Peru--comparison of different fuel types used for cooking.

    PubMed

    Adetona, Olorunfemi; Li, Zheng; Sjödin, Andreas; Romanoff, Lovisa C; Aguilar-Villalobos, Manuel; Needham, Larry L; Hall, Daniel B; Cassidy, Brandon E; Naeher, Luke P

    2013-03-01

    Women and children in developing countries are often exposed to high levels of air pollution including polycyclic aromatic hydrocarbons (PAHs), which may negatively impact their health, due to household combustion of biomass fuel for cooking and heating. We compared creatinine adjusted hydroxy-PAH (OH-PAH) concentrations in pregnant women in Trujillo, Peru who cook with wood to levels measured in those who cook with kerosene, liquefied petroleum gas or a combination of fuels. Seventy-nine women were recruited for the study between May and July 2004 in the first trimester of their pregnancy. Urine samples were collected from the subjects in the first, second and third trimesters for OH-PAH analyses. The concentrations of the OH-PAHs were compared across the type of fuel used for cooking and pregnancy trimesters. The relationships between OH-PAHs levels in the first trimester and concurrently measured personal exposures to PM₂.₅, carbon monoxide and nitrogen dioxide together with their indoor and outdoor air concentrations were also investigated. Women cooking with wood or kerosene had the highest creatinine adjusted OH-PAH concentrations compared with those using gas, coal briquette or a combination of fuels. Concentrations of creatinine adjusted 2-hydroxy-fluorene, 3-hydroxy-fluorene, 1-hydroxy-fluorene, 2-hydroxy-phenanthrene and 4-hydroxy-phenanthrene were significantly higher (p<0.05) in women who used wood or kerosene alone compared with women who used liquefied petroleum gas (LPG), coal briquette or a combination of fuels. An increase in the concentrations of creatinine adjusted 9-hydroxy-fluorene, 1-hydroxy-phenanthrene, 2-hydroxy-phenanthrene, 4-hydroxy-phenanthrene and 1-hydroxy-pyrene in the third trimesters was also observed. Weak positive correlation (Spearman correlation coefficient, ρ<0.4; p<0.05) was observed between all first trimester creatinine adjusted OH-PAHs and indoor (kitchen and living room), and personal 48-h TWA PM₂.₅. Women who

  20. DNA Oxidation Profiles of Copper Phenanthrene Chemical Nucleases

    NASA Astrophysics Data System (ADS)

    Molphy, Zara; Slator, Creina; Chatgilialoglu, Chryssostomos; Kellett, Andrew

    2015-04-01

    The deleterious effects of metal-catalyzed reactive oxygen species (ROS) in biological systems can be seen in a wide variety of pathological conditions including cancer, cardiovascular disease, ageing, and neurodegenerative disorder. On the other hand however, targeted ROS production in the vicinity of nucleic acids - as demonstrated by metal-activated bleomycin - has paved the way for ROS-active chemotherapeutic drug development. Herein we report mechanistic investigations into the oxidative nuclease activity and redox properties of copper(II) developmental therapeutics [Cu(DPQ)(phen)]2+ (Cu-DPQ-Phen), [Cu(DPPZ)(phen)]2+ (Cu-DPPZ-Phen), and [{Cu(phen)2}2(μ-terph)](terph) (Cu-Terph), with results being compared directly to Sigman’s reagent [Cu(phen)2]2+ throughout (phen = 1,10-phenanthroline; DPQ = dipyridoquinoxaline; DPPZ = dipyridophenazine). Oxidative DNA damage was identified at the minor groove through use of surface bound recognition elements of methyl green, netropsin, and [Co(NH3)6]Cl3 that functioned to control complex accessibility at selected regions. ROS-specific scavengers and stabilisers were employed to identify the cleavage process, the results of which infer hydrogen peroxide produced metal-hydroxo or free hydroxyl radicals (•OH) as the predominant species. The extent of DNA damage owing to these radicals was then quantified through 8-oxo-2'-deoxyguanosine (8-oxo-dG) lesion detection under ELISA protocol with the overall trend following Cu-DPQ-Phen > Cu-Terph > Cu-Phen > Cu-DPPZ. Finally, the effects of oxidative damage on DNA replication processes were investigated using the polymerase chain reaction (PCR) where amplification of 120 base pair DNA sequences of varying base content were inhibited - particularly along A-T rich chains - through oxidative damage of the template strands.