Biodegradation of naphthalene and phenanthren by Bacillus subtilis 3KP

NASA Astrophysics Data System (ADS)

Ni'matuzahroh, Trikurniadewi, N.; Pramadita, A. R. A.; Pratiwi, I. A.; Salamun, Fatimah, Sumarsih, Sri

2017-06-01

The purposes of this research were to know growth response, degradation ability, and uptake mechanism of naphthalene and phenanthrene by Bacillus subtilis 3KP. Bacillus subtilis 3KP was grown on Mineral Synthetic (MS) medium with addition of 1% yeast extract and naphthalene and phenanthrene respectively 200 ppm in different cultures. Bacillus subtilis 3KP growth response was monitored by Total Plate Count (TPC) method, the degradation ability was monitored by UV-Vis spectrophotometer, and the uptake mechanism of hydrocarbon was monitored by emulsification activity, decrease of surface tension, and activity of Bacterial Adherence to Hydrocarbon (BATH). Bacillus subtilis 3KP was able to grow and show biphasic growth pattern on both of substrates. Naphthalene and phenanthrene were used as a carbon source for Bacillus subtilis 3KP growth that indicated by the reduction of substrate concomitant with the growth. At room temperature conditions (± 30°C) and 90 rpm of agitation for 7 days, Bacillus subtilis 3KP could degrade naphthalene in the amount of 70.5% and phenanthrene in the amount of 24.8%. Based on the analysis of UV-Vis spectrophotometer, three metabolites, 1-hydroxy-2-naphthoic acid, salicylic acid, and pyrocatechol were found in both cultures. The metabolite identification became basis of propose degradation pathway of naphthalene and phenanthrene by Bacillus subtilis 3KP. The results of hydrocarbon uptake mechanism test show that Bacillus subtilis 3KP used all of the mechanism to degrade naphthalene and phenanthrene.

Biodegradation of naphthalene and anthracene by chemo-tactically active rhizobacteria of populus deltoides

PubMed Central

Bisht, Sandeep; Pandey, Piyush; Sood, Anchal; Sharma, Shivesh; Bisht, N. S.

2010-01-01

Several naphthalene and anthracene degrading bacteria were isolated from rhizosphere of Populus deltoides, which were growing in non-contaminated soil. Among these, four isolates, i.e. Kurthia sp., Micrococcus varians, Deinococcus radiodurans and Bacillus circulans utilized chrysene, benzene, toluene and xylene, in addition to anthracene and naphthalene. Kurthia sp and B. circulans showed positive chemotactic response for naphthalene and anthracene. The mean growth rate constant (K) of isolates were found to increase with successive increase in substrate concentration (0.5 to 1.0 mg/50ml). B. circulans SBA12 and Kurthia SBA4 degraded 87.5% and 86.6% of anthracene while, Kurthia sp. SBA4, B. circulans SBA12, and M. varians SBA8 degraded 85.3 %, 95.8 % and 86.8 % of naphthalene respectively after 6 days of incubation as determined by HPLC analysis. PMID:24031572

Microbial characterization and hydrocarbon biodegradation potential of natural bilge waste microflora.

PubMed

Olivera, N L; Commendatore, M G; Delgado, O; Esteves, J L

2003-09-01

Shipping operations produce oily wastes that must be managed properly to avoid environmental pollution. The aim of this study was to characterize microorganisms occurring in ship bilge wastes placed in open lagoons and, particularly, to assess their potential to degrade polycyclic aromatic hydrocarbons (PAHs). A first-order kinetic was suitable for describing hydrocarbon biodegradation after 17 days of treatment. The calculated rate constants were 0.0668 and 0.0513 day(-1) with a corresponding half-life of 10.3 and 13.5 days for the aliphatic and aromatic hydrocarbon fractions, respectively. At day 17, PAH removal percentages were: acenaphtylene 100, fluorene 95.2, phenanthrene 93.6, anthracene 70.3, and pyrene 71.5. Methyl phenanthrene removals were lower than that of their parent compound (3-methyl phenanthrene 83.6, 2-methyl phenanthrene 80.8, 1-methyl phenanthrene 77.3, 9-methyl phenanthrene 75.1, and 2,7-dimethyl phenanthrene 76.6). Neither pure cultures nor the microbial community from these wastes showed extracellular biosurfactant production suggesting that the addition of an exogenously produced biosurfactant may be important in enhancing hydrocarbon bioavailability and biodegradation. DNA analysis of bilge waste samples revealed a ubiquitous distribution of the nahAc genotype in the dump pools. Although almost all of the isolates grew on naphthalene as sole carbon source, only some of them yielded nahAc amplification under the experimental conditions used. The variety of PAHs in bilge wastes could support bacteria with multiple degradation pathways and a diversity of catabolic genes divergent from the classical nah-like type.

Phototoxic effects of PAH and UVA exposure on molecular responses and developmental success in coral larvae.

PubMed

Overmans, Sebastian; Nordborg, Mikaela; Díaz-Rúa, Rubén; Brinkman, Diane L; Negri, Andrew P; Agustí, Susana

2018-05-01

Exposure to polycyclic aromatic carbons (PAHs) poses a growing risk to coral reefs due to increasing shipping and petroleum extraction in tropical waters. Damaging effects of specific PAHs can be further enhanced by the presence of ultraviolet radiation, known as phototoxicity. We tested phototoxic effects of the PAHs anthracene and phenanthrene on larvae of the scleractinian coral Acropora tenuis in the presence and absence of UVA (320-400 nm). Activity of superoxide dismutase (SOD) enzyme was reduced by anthracene while phenanthrene and UVA exposure did not have any effect. Gene expression of MnSod remained constant across all treatments. The genes Catalase, Hsp70 and Hsp90 showed increased expression levels in larvae exposed to anthracene, but not phenanthrene. Gene expression of p53 was upregulated in the presence of UVA, but downregulated when exposed to PAHs. The influence on stress-related biochemical pathways and gene expresson in A. tenuis larvae was considerably greater for anthracene than phenanthrene, and UVA-induced phototoxicity was only evident for anthracene. The combined effects of UVA and PAH exposure on larval survival and metamorphosis paralleled the sub-lethal stress responses, clearly highlighting the interaction of UVA on anthracene toxicity and ultimately the coral's development. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Uptake of polycyclic aromatic hydrocarbons and their cellular effects in the mangrove Bruguiera gymnorrhiza.

PubMed

Naidoo, Gonasageran; Naidoo, Krishnaveni

2016-12-15

The uptake of polycyclic aromatic hydrocarbons and their cellular effects were investigated in the mangrove Bruguiera gymnorrhiza. Seedlings were subjected to sediment oiling for three weeks. In the oiled treatment, the ƩPAHs was higher in roots (99%) than in leaves (1%). In roots, PAHs included phenanthrene (55%), acenaphthene (13%), fluorine (12%) and anthracene (8%). In leaves, PAHs possessed two to three rings and included acenaphthene (35%), naphthalene (33%), fluorine (18%) and phenanthrene (14%). In the roots, oil caused disorganization of cells in the root cap, meristem and conducting tissue. Oil contaminated cells were distorted and possessed large and irregularly shaped vacuoles. Ultrastructural changes included loss of cell contents and fragmentation of the nucleus and mitochondrion. In the leaves, oil caused dilation and distortion of chloroplasts and disintegration of grana and lamellae. Oil targets critical organelles such as nuclei, chloroplasts and mitochondria which are responsible for cell vitality and energy transformation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Leaching of polycyclic aromatic hydrocarbons from oil shale processing waste deposit: a long-term field study.

PubMed

Jefimova, Jekaterina; Irha, Natalya; Reinik, Janek; Kirso, Uuve; Steinnes, Eiliv

2014-05-15

The leaching behavior of selected polycyclic aromatic hydrocarbons (PAHs) from an oil shale processing waste deposit was monitored during 2005-2009. Samples were collected from the deposit using a special device for leachate sampling at field conditions without disturbance of the upper layers. Contents of 16 priority PAHs in leachate samples collected from aged and fresh parts of the deposit were determined by GC-MS. The sum of the detected PAHs in leachates varied significantly throughout the study period: 19-315 μg/l from aged spent shale, and 36-151 μg/l from fresh spent shale. Among the studied PAHs the low-molecular weight compounds phenanthrene, naphthalene, acenaphthylene, and anthracene predominated. Among the high-molecular weight PAHs benzo[a]anthracene and pyrene leached in the highest concentrations. A spent shale deposit is a source of PAHs that could infiltrate into the surrounding environment for a long period of time. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantifying the equilibrium partitioning of substituted polycyclic aromatic hydrocarbons in aerosols and clouds using COSMOtherm.

PubMed

Awonaike, Boluwatife; Wang, Chen; Goss, Kai-Uwe; Wania, Frank

2017-03-22

Functional groups attached to polycyclic aromatic hydrocarbons (PAHs) can significantly modify the environmental fate of the parent compound. Equilibrium partition coefficients, which are essential for describing the environmental phase distribution of a compound, are largely unavailable for substituted PAHs (SPAHs). Here, COSMOtherm, a software based on quantum-chemical calculations is used to estimate the atmospherically relevant partition coefficients between the gas phase, the aqueous bulk phase, the water surface and the water insoluble organic matter phase, as well as the salting-out coefficients, for naphthalene, anthracene, phenanthrene, benz(a)anthracene, benzo(a)pyrene and dibenz(a,h)anthracene and 62 of their substituted counterparts. They serve as input parameters for the calculation of equilibrium phase distribution of these compounds in aerosols and clouds. Our results, which were compared with available experimental data, show that the effect of salts, the adsorption to the water surface and the dissolution in a bulk aqueous phase can be safely neglected when estimating the gas-particle partitioning of SPAHs in aerosols. However, for small PAHs with more than one polar functional group the aqueous phase can be the dominant reservoir in a cloud.

Identification and quantification of phencyclidine pyrolysis products formed during smoking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lue, L.P.; Scimeca, J.A.; Thomas, B.F.

As a result of frequent phencyclidine (PCP) abuse, pyrolysis studies were conducted to further investigate its fate during smoking. Marijuana placebo cigarettes were impregnated with /sup 3/H-PCP HCl and burned under conditions simulating smoking. Mainstream smoke was passed through glass wool filters as well as acidic and basic traps. Approximately 90% of the starting material could be accounted for in the first glass wool trap and cigarette holder. HPLC and GC/MS analysis of methanol extracts of these glass wool traps revealed the presence of 1-phenyl-1-cyclohexene (47% of the starting material) > PCP (40%) > piperidine (15%) > N-acetylpiperidine (9%). Itmore » was not possible to fully account for the remainder of the piperidine moiety. It has been reported that at high temperatures PCP is converted to numerous polynuclear aromatic compounds which include styrene, ..cap alpha..-methylstyrene, naphthalene, 2-methyl-naphthalene, 1-methylnaphthalene, biphenyl, cyclohexylbenzene, acenaphthene, phenanthrene, and anthracene. These compounds were not formed from PCP under smoking conditions.« less

The Triplet State

NASA Astrophysics Data System (ADS)

Zahlan, A. B.

2010-01-01

Preface; List of participants; Part I. Spin-orbit Coupling and Intersystem Crossing: 1. Spin-orbit interactions in organic molecules; 2. Singlet-triplet transitions in organic molecules; 3. Triplet decay and intersystem crossing in aromatic hydrocarbons; 4. Statistical aspects of resonance energy transfer; Discussion; Part II. Magnetic Resonance and Magnetic Interactions: 5. Magnetic resonance spectra of organic molecules in triplet states in single crystals; 6. Magnetic interactions related to phosphorescence; 7. ESR investigations of naphthalene-d8:Naphthalene-h8 mixed crystals; 8. Biradicals and polyradicals in the nitroxide series; 9. Changes induced in the phosphorescent radiation of aromatic molecules by paramagnetic resonance in their metastable triplet states; 10. Paramagnetic resonance of the triplet state of tetramethylpyrazine; 11. On magnetic dipole contributions to the intrinsic S0 = T1 transition in simple aromatics; Discussion; Part III. Photochemistry: 12. The kinetics of energy transfer from the triplet state in rigid solutions; 13. Triplet states in gas-phase photochemistry; 14. Biphotonic photochemistry, involving the triplet state: polarisation of the effective T-T transition and solvent effects; 15. Direct and sensitised photo-oxidation of aromatic hydrocarbons in boric acid glass; Discussion; Part IV. Radiationless Transitions: 16. Radiationless transitions in gaseous benzene; 17. Low-lying excited triplet states and intersystem crossing in aromatic hydrocarbons; 18. De-excitation rates of triplet states in condensed media; 19. Lifetimes of the triplet state of aromatic hydrocarbons in the vapour phase; Discussion; Part V. Triplet Excitons: 20. Some comments on the properties of triplet excitons in molecular crystals; 21. Exact treatment of coherent and incoherent triplet exciton migration; 22. Magnetic susceptibility of a system of triplet excitons: Würster's Blue Perchlorate; 23. A study of triplet excitons in anthracene crystals under laser excitation; 24. The electronic states in crystaline anthracene; Discussion; Part VI. Delayed Fluorescent and Phosphorescence: 25. Delayed fluorescence of solutions; 26. The kinetics of the excited states of anthracene and phenanthrene vapor; 27. Optical investigations of the triplet states of naphthalene in different crystalline environments; 28. Excitation of the triplet states of organic molecules; 29. The delayed luminescence and triplet quantum yields of pyrene solutions; 30. Triplet state studies of some polyphenyls in rigid glasses; 31. Decay time of delayed fluorescence of anthracene as a function of temperature (2-30ºK); 32. Energy transfer between benzene and biacetyl and the lifetime of triplet benzene in the gas phase; 33. Charge transfer triplet state of molecular complexes. 34. Flash-photolytic detection of triplet acridine formed by energy transfer from biacetyl; 35. Extinction coefficients of triplet-triplet transitions between 3000 and 8800 A in anthracene; 36. Anthracene triplet-triplet annihilation rate constant; Discussion; Part VII. Triplet State Related to Biology: 37. ESR and optical studies of some triplet states of biological interest; 38. The triplet state of DNA; 39. Some characteristics of the triplet states of the nucleic bases; Discussion; Indexes.

Reduced biodegradability of desorption-resistant fractions of polycyclic aromatic hydrocarbons in soil and aquifer solids

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, J.C.; Alexander, M.

1996-11-01

Less of the desorption-resistant fractions of phenanthrene and naphthalene than freshly added phenanthrene and naphthalene was mineralized in columns of aquifer solids, loam, or muck. Slurrying columns of hydrocarbon-amended aquifer solids, loam, or muck enhanced the rate and extent of mineralization of desorption-resistant phenanthrene and naphthalene, but degradation was still less than in slurries amended with fresh compound. A substantial portion of the desorption-resistant compound remained undergraded in the slurry. A surfactant and methanol increased the mineralization of resistant phenanthrene in slurries of loam. A mixed culture of microorganisms enriched on desorption-resistant phenanthrene degraded twice as much of this fractionmore » of compound as a pseudomonad. The authors suggest that predictions of the environment fate of toxic chemicals require information on the biodegradability of the fraction of a compound that is resistant to desorption.« less

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.

Influence of fuel composition on polycyclic aromatic hydrocarbon emissions from a fleet of in-service passenger cars

NASA Astrophysics Data System (ADS)

Lim, McKenzie C. H.; Ayoko, Godwin A.; Morawska, Lidia.; Ristovski, Zoran D.; Jayaratne, E. Rohan

The composition of exhaust emissions from eight in-service passenger cars powered by liquefied petroleum gas (LPG) and unleaded petrol (ULP) were measured on a chassis dynamometer at two driving speeds (60 and 80 km h -1) with the aims of evaluating their polycyclic aromatic hydrocarbon (PAH) contents and investigating the effects of the type of fuel on vehicle performance, ambient air quality and associated health risks. Naphthalene, fluorene, phenanthrene, anthracene, pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene were the most prominent PAHs emitted by both ULP and LPG powered cars. The total emission factors of PAHs from LPG cars were generally lower than (but statistically comparable with) those of ULP cars. Similarly, the total BAP eq of the PAHs emitted by LPG cars were lower than those from ULP cars. Multi-criteria decision making (MCDM) methods showed that cars powered by LPG fuel performed better than those powered by ULP fuel in term of PAH levels. The implications of these observations on the advantages and disadvantages of using ULP and LPG fuels are discussed.

Biodegradation of polycyclic hydrocarbons by Phanerochaete chrysosporium.

PubMed

Bumpus, J A

1989-01-01

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance liquid chromatography showed that at least 22 PAHs, including all of the most abundant PAH components present in anthracene oil, underwent 70 to 100% disappearance during 27 days of incubation with nutrient nitrogen-limited cultures of this fungus. Because phenanthrene is the most abundant PAH present in anthracene oil, this PAH was selected for further study. In experiments in which [14C]phenanthrene was incubated with cultures of P. chrysosporium containing anthracene oil for 27 days, it was shown that 7.7% of the recovered radiolabeled carbon originally present in [14C]phenanthrene was metabolized to 14CO2 and 25.2% was recovered from the aqueous fraction, while 56.1 and 11.0% were recovered from the methylene chloride and particulate fractions, respectively. High-performance liquid chromatography of the 14C-labeled material present in the methylene chloride fraction revealed that most (91.9%) of this material was composed of polar metabolites of [14C]phenanthrene. These results suggest that this microorganism may be useful for the decontamination of sites in the environment contaminated with PAHs.

Biodegradation of polycyclic hydrocarbons by Phanerochaete chrysosporium.

PubMed Central

Bumpus, J A

1989-01-01

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance liquid chromatography showed that at least 22 PAHs, including all of the most abundant PAH components present in anthracene oil, underwent 70 to 100% disappearance during 27 days of incubation with nutrient nitrogen-limited cultures of this fungus. Because phenanthrene is the most abundant PAH present in anthracene oil, this PAH was selected for further study. In experiments in which [14C]phenanthrene was incubated with cultures of P. chrysosporium containing anthracene oil for 27 days, it was shown that 7.7% of the recovered radiolabeled carbon originally present in [14C]phenanthrene was metabolized to 14CO2 and 25.2% was recovered from the aqueous fraction, while 56.1 and 11.0% were recovered from the methylene chloride and particulate fractions, respectively. High-performance liquid chromatography of the 14C-labeled material present in the methylene chloride fraction revealed that most (91.9%) of this material was composed of polar metabolites of [14C]phenanthrene. These results suggest that this microorganism may be useful for the decontamination of sites in the environment contaminated with PAHs. PMID:2705768

Effect of rhamnolipid biosurfactant on solubilization of polycyclic aromatic hydrocarbons.

PubMed

Li, Shudong; Pi, Yongrui; Bao, Mutai; Zhang, Cong; Zhao, Dongwei; Li, Yiming; Sun, Peiyan; Lu, Jinren

2015-12-15

Rhamnolipid biosurfactant-producing bacteria, Bacillus Lz-2, was isolated from oil polluted water collected from Dongying Shengli oilfield, China. The factors that influence PAH solubilization such as biosurfactant concentration, pH, ionic strength and temperature were discussed. The results showed that the solubilities of naphthalene, phenanthrene and pyrene increased linearly with the rise of rhamnolipid biosurfactant dose above the biosurfactant critical micelle concentration (CMC). Furthermore, the molar solubilization ratio (MSR) values decreased in the following order: naphthalene>phenanthrene>pyrene. However, the solubility percentage increased and followed the opposite order: pyrene>phenanthrene>naphthalene. The solubilities of PAHs in rhamnolipid biosurfactant solution increased with the rise of pH and ionic strength, and reached the maximum values under the conditions of pH11 and NaCl concentration 8 g · L(-1). The solubility of phenanthrene and pyrene increased with the rise of temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stable-Isotope Probing of Bacteria Capable of Degrading Salicylate, Naphthalene, or Phenanthrene in a Bioreactor Treating Contaminated Soil

PubMed Central

Singleton, David R.; Powell, Sabrina N.; Sangaiah, Ramiah; Gold, Avram; Ball, Louise M.; Aitken, Michael D.

2005-01-01

[13C6]salicylate, [U-13C]naphthalene, and [U-13C]phenanthrene were synthesized and separately added to slurry from a bench-scale, aerobic bioreactor used to treat soil contaminated with polycyclic aromatic hydrocarbons. Incubations were performed for either 2 days (salicylate, naphthalene) or 7 days (naphthalene, phenanthrene). Total DNA was extracted from the incubations, the “heavy” and “light” DNA were separated, and the bacterial populations associated with the heavy fractions were examined by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Unlabeled DNA from Escherichia coli K-12 was added to each sample as an internal indicator of separation efficiency. While E. coli was not detected in most analyses of heavy DNA, a low number of E. coli sequences was recovered in the clone libraries associated with the heavy DNA fraction of [13C]phenanthrene incubations. The number of E. coli clones recovered proved useful in determining the relative amount of light DNA contamination of the heavy fraction in that sample. Salicylate- and naphthalene-degrading communities displayed similar DGGE profiles and their clone libraries were composed primarily of sequences belonging to the Pseudomonas and Ralstonia genera. In contrast, heavy DNA from the phenanthrene incubations displayed a markedly different DGGE profile and was composed primarily of sequences related to the Acidovorax genus. There was little difference in the DGGE profiles and types of sequences recovered from 2- and 7-day incubations with naphthalene, so secondary utilization of the 13C during the incubation did not appear to be an issue in this experiment. PMID:15746319

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 alone.

Oxidation kinetics of polycyclic aromatic hydrocarbons by permanganate.

PubMed

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

2010-04-01

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

Input and behavior of polycyclic aromatic hydrocarbons in arable, fallow, and forest soils of the taiga zone (Tver oblast)

NASA Astrophysics Data System (ADS)

Zhidkin, A. P.; Gennadiev, A. N.; Koshovskii, T. S.

2017-03-01

Contents of 11 most prevalent polycyclic aromatic hydrocarbons (PAHs) in snow and soils of arable, fallow, and forest areas significantly remote from impact technogenic sources of polyarenes have been examined in the Torzhok district of Tver oblast. From the analysis of snow samples, the volumes and composition of PAHs coming from the atmosphere onto the areas of different land use have been determined. Light hydrocarbons prevail in PAHs. They make up 65-70% of total PAHs; their share in soils reaches almost 95%. An increase in the content of PAHs is revealed in fallow soils compared to arable and afforested areas. A direct relationship is revealed between the lateral distribution of total PAHs and the content of organic carbon. The distribution of total PAHs is surface-accumulative in forest soils, mainly uniform in arable soils, and deepaccumulative in fallow soils. PAH groups characterized by similar radial distributions and ratios between their reserves in snow and soils are distinguished: (1) fluorene and phenanthrene, (2) biphenyl and naphthalene, (3) benzo(a)anthracene, chrysene, perylene, and benzo[ a]pyrene, and (4) anthracene and benzo[ ghi]pyrene.

Gene cloning and in vivo characterization of a dibenzothiophene dioxygenase from Xanthobacter polyaromaticivorans.

PubMed

Hirano, Shin-Ichi; Haruki, Mitsuru; Takano, Kazufumi; Imanaka, Tadayuki; Morikawa, Masaaki; Kanaya, Shigenori

2006-02-01

Xanthobacter polyaromaticivorans sp. nov. 127W is a bacterial strain that is capable of degrading a wide range of cyclic aromatic compounds such as dibenzothiophene, biphenyl, naphthalene, anthracene, and phenanthrene even under extremely low oxygen [dissolved oxygen (DO)< or = 0.2 ppm] conditions (Hirano et al., Biosci Biotechnol Biochem 68:557-564, 2004). A major protein fraction carrying dibenzothiophene degradation activity was purified. Based on its partial amino acid sequences, dbdCa gene encoding alpha subunit terminal oxygenase (DbdCa) and its flanking region were cloned and sequenced. A phylogenetic analysis based on the amino acid sequence demonstrates that DbdCa is a member of a terminal oxygenase component of group IV ring-hydroxylating dioxygenases for biphenyls and monocyclic aromatic hydrocarbons, rather than group III dioxygenases for polycyclic aromatic hydrocarbons. Gene disruption in dbdCa abolished almost of the degradation activity against biphenyl, dibenzothiophene, and anthracene. The gene disruption also impaired degradation activity of the strain under extremely low oxygen conditions (DO< or = 0.2 ppm). These results indicate that Dbd from 127W represents a group IV dioxygenase that is functional even under extremely low oxygen conditions.

Ice growth from supercooled aqueous solutions of benzene, naphthalene, and phenanthrene.

PubMed

Liyana-Arachchi, Thilanga P; Valsaraj, Kalliat T; Hung, Francisco R

2012-08-23

Classical molecular dynamics (MD) were performed to investigate the growth of ice from supercooled aqueous solutions of benzene, naphthalene, or phenanthrene. The main objective of this study is to explore the fate of those aromatic molecules after freezing of the supercooled aqueous solutions, i.e., if these molecules become trapped inside the ice lattice or if they are displaced to the QLL or to the interface with air. Ice growth from supercooled aqueous solutions of benzene, naphthalene, or phenanthrene result in the formation of quasi-liquid layers (QLLs) at the air/ice interface that are thicker than those observed when pure supercooled water freezes. Naphthalene and phenanthrene molecules in the supercooled aqueous solutions are displaced to the air/ice interface during the freezing process at both 270 and 260 K; no incorporation of these aromatics into the ice lattice is observed throughout the freezing process. Similar trends were observed during freezing of supercooled aqueous solutions of benzene at 270 K. In contrast, a fraction of the benzene molecules become trapped inside the ice lattice during the freezing process at 260 K, with the rest of the benzene molecules being displaced to the air/ice interface. These results suggest that the size of the aromatic molecule in the supercooled aqueous solution is an important parameter in determining whether these molecules become trapped inside the ice crystals. Finally, we also report potential of mean force (PMF) calculations aimed at studying the adsorption of gas-phase benzene and phenanthrene on atmospheric air/ice interfaces. Our PMF calculations indicate the presence of deep free energy minima for both benzene and phenanthrene at the air/ice interface, with these molecules adopting a flat orientation at the air/ice interface.

Do nonbonded H--H interactions in phenanthrene stabilize it relative to anthracene? A possible resolution to this question and its implications for ligands such as 2,2'-bipyridyl.

PubMed

Hancock, Robert D; Nikolayenko, Igor V

2012-08-23

The problem of whether interactions between the hydrogen atoms at the 1,10-positions in the "cleft" of the "bent" phenanthrene stabilize the latter molecule thermodynamically relative to "linear" anthracene, or whether the higher stability of phenanthrene is due to a more energetically favorable π-system, is considered. DFT calculations at the X3LYP/cc-pVTZ(-f)++ level of the ground state energies (E) of anthracene, phenanthrene, and the set of five benzoquinolines are reported. In the gas phase, "bent" phenanthrene was computed to be thermodynamically more stable than "linear" anthracene by -28.5 kJ mol(-1). This fact was attributed predominantly to the phenomenon of higher aromatic stabilization of the π-system of phenanthrene relative to anthracene, and not to the stabilizing influence of the nonbonding H--H interactions in its cleft. In fact, these interactions in phenanthrene were shown to be destabilizing. Similar calculations for five benzoquinolines (bzq) indicate that ΔE values vary as: 6,7-bzq (linear) ≤ 2,3-bzq (linear) < 5,6-bzq (bent) ≤ 3,4-bzq (bent) < 7,8-bzq (bent, no H--H nonbonding interactions in cleft), supporting the idea that it is a more stable π-system that favors 7,8-bzq over 2,3-bzq and 6,7-bzq, and that the H--H interactions in the clefts of 3,4-bzq and 5,6-bzq are destabilizing. Intramolecular hydrogen bonding in the cleft of 7,8-bzq plays a secondary role in its stabilization relative 6,7-bzq. The question of whether H--H nonbonded interactions between H atoms at the 3 and 3' positions of 2,2'-bipyridyl (bpy) coordinated to metal ions are stabilizing or destabilizing is then considered. The energy of bpy is scanned as a function of N-C-C-N torsion angle (χ) in the gas-phase, and it is found that the trans form is 32.8 kJ mol(-1) more stable than the cis conformer. A relaxed coordinate scan of energy of bpy in aqueous solution as a function of χ is modeled using the PBF approach, and it is found that the trans conformer is still more stable than the cis, but now only by 5.34 kJ mol(-1). The effect that the latter energy has on the thermodynamic stability of complexes of metal ions with bpy in aqueous solution is discussed.

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.

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.

A comparative study to evaluate natural attenuation, mycoaugmentation, phytoremediation, and microbial-assisted phytoremediation strategies for the bioremediation of an aged PAH-polluted soil.

PubMed

García-Sánchez, Mercedes; Košnář, Zdeněk; Mercl, Filip; Aranda, Elisabet; Tlustoš, Pavel

2018-01-01

Biological treatments are considered an environmentally option to clean-up polluted soil with polycyclic aromatic hydrocarbons (PAHs). A pot experiment was conducted to comparatively evaluate four different strategies, including natural attenuation (NA), mycoaugmentation (M) by using Crucibulum leave, phytoremediation (P) using maize plants, and microbial-assisted phytoremediation (MAP) for the bioremediation of an aged PAH-polluted soil at 180 days. The P treatment had higher affinity degrading 2-3 and 4 ring compounds than NA and M treatments, respectively. However, M and P treatments were more efficient in regards to naphthalene, indeno[l,2,3-c,d]pyrene and benzo[g,h,i]perylene degradation respect to NA. However, 4, 5-6 rings undergo a strong decline during the microbe-assisted phytoremediation, being the treatment which determined the highest rates of PAHs degradation. Sixteen PAH compounds, except fluorene and dibenzo[a,h]anthracene, were found in maize roots, whereas the naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene were accumulated in the shoots, in both P and MAP treatments. However, higher PAH content in maize biomass was achieved during the MAP treatment respect to P treatment. The bioconversion and translocation factors were less than 1, indicating that phystabilization/phytodegradation processes occurred rather than phytoextraction. The microbial biomass, activity and ergosterol content were significantly boosted in the MAP treatment respect to the other treatments at 180 days. Ours results demonstrated that maize-C. laeve association was the most profitable technique for the treatment of an aged PAH-polluted soil when compared to other bioremediation approaches. Copyright © 2017 Elsevier Inc. All rights reserved.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Degradation of phenanthrene by Burkholderia sp. C3: initial 1,2- and 3,4-dioxygenation and meta- and ortho-cleavage of naphthalene-1,2-diol.

PubMed

Seo, Jong-Su; Keum, Young-Soo; Hu, Yuting; Lee, Sung-Eun; Li, Qing X

2007-02-01

Burkholderia sp. C3 was isolated from a polycyclic aromatic hydrocarbon (PAH)-contaminated site in Hilo, Hawaii, USA, and studied for its degradation of phenanthrene as a sole carbon source. The initial 3,4-C dioxygenation was faster than 1,2-C dioxygenation in the first 3-day culture. However, 1-hydroxy-2-naphthoic acid derived from 3,4-C dioxygenation degraded much slower than 2-hydroxy-1-naphthoic acid derived from 1,2-C dioxygenation. Slow degradation of 1-hydroxy-2-naphthoic acid relative to 2-hydroxy-1-naphthoic acid may trigger 1,2-C dioxygenation faster after 3 days of culture. High concentrations of 5,6- and 7,8-benzocoumarins indicated that meta-cleavage was the major degradation mechanism of phenanthrene-1,2- and -3,4-diols. Separate cultures with 2-hydroxy-1-naphthoic acid and 1-hydroxy-2-naphthoic acid showed that the degradation rate of the former to naphthalene-1,2-diol was much faster than that of the latter. The two upper metabolic pathways of phenanthrene are converged into naphthalene-1,2-diol that is further metabolized to 2-carboxycinnamic acid and 2-hydroxybenzalpyruvic acid by ortho- and meta-cleavages, respectively. Transformation of naphthalene-1,2-diol to 2-carboxycinnamic acid by this strain represents the first observation of ortho-cleavage of two rings-PAH-diols by a Gram-negative species.

Recyclable nanoscale zero-valent iron-based magnetic polydopamine coated nanomaterials for the adsorption and removal of phenanthrene and anthracene

NASA Astrophysics Data System (ADS)

Li, Jing; Zhou, Qingxiang; Liu, Yongli; Lei, Man

2017-12-01

In this study, nanoscale zero-valent iron nanoparticles (NZVIs) were coated with silica and polydopamine using a two-step process. The coated nanoparticles were applied as adsorbents for removal of two common polycyclic aromatic hydrocarbons pollutants, phenanthrene (PHE) and anthracene (ANT) from aqueous system. Adsorption kinetics followed a pseudo-second-order model. Isotherms and thermodynamics were investigated and the results indicated that the adsorption process fit best to the Freundlich model and exhibited the characteristics of an exothermal physical adsorption process. Owing to their superparamagnetic characteristics and stability, these adsorbents could be easily collected and recycled for reuse.

Hydrous pyrolysis of polycyclic aromatic hydrocarbons and implications for the origin of PAH in hydrothermal petroleum

NASA Technical Reports Server (NTRS)

McCollom, T. M.; Simoneit, B. R.; Shock, E. L.

1999-01-01

Polycyclic aromatic hydrocarbons (PAH) are found at high concentrations in thermally altered organic matter and hydrothermally generated petroleum from sediment-covered seafloor hydro-thermal systems. To better understand the factors controlling the occurrence of PAH in thermally altered environments, the reactivities of two PAH, phenanthrene and anthracene, were investigated in hydrothermal experiments. The compounds were heated with water at 330 degrees C in sealed reaction vessels for durations ranging from 1 to 17 days. Iron oxide and sulfide minerals, formic acid, or sodium for-mate were included in some experiments to vary conditions within the reaction vessel. Phenanthrene was unreactive both in water alone and in the presence of minerals for up to 17 days, while anthracene was partially hydrogenated (5-10%) to di- and tetrahydroanthracene. In the presence of 6-21 vol % formic acid, both phenanthrene and anthracene reacted extensively to form hydrogenated and minor methylated derivatives, with the degree of hydrogenation and methylation increasing with the amount of formic acid. Phenanthrene was slightly hydrogenated in sodium formate solutions. The hydrogenation reactions could be readily reversed; heating a mixture of polysaturated phenanthrenes resulted in extensive dehydrogenation (aromatization) after 3 days at 330 degrees C. While the experiments demonstrate that reaction pathways for the hydrogenation of PAH under hydrothermal conditions exist, the reactions apparently require higher concentrations of H2 than are typical of geologic settings. The experiments provide additional evidence that PAH may be generated in hydrothermal systems from progressive aromatization and dealkylation of biologically derived polycyclic precursors such as steroids and terpenoids. Furthermore, the results indicate that PAH initially present in sediments or formed within hydrothermal systems are resistant to further thermal degradation during hydrothermal alteration.

Does the concept of Clar's aromatic sextet work for dicationic forms of polycyclic aromatic hydrocarbons?--testing the model against charged systems in singlet and triplet states.

PubMed

Dominikowska, Justyna; Palusiak, Marcin

2011-07-07

The concept of Clar's π-electron aromatic sextet was tested against a set of polycyclic aromatic hydrocarbons in neutral and doubly charged forms. Systems containing different types of rings (in the context of Clar's concept) were chosen, including benzene, naphthalene, anthracene, phenanthrene and triphenylene. In the case of dicationic structures both singlet and triplet states were considered. It was found that for singlet state dicationic structures the concept of aromatic sextet could be applied and the local aromaticity could be discussed in the context of that model, whereas in the case of triplet state dicationic structures Clar's model rather failed. Different aromaticity indices based on various properties of molecular systems were applied for the purpose of the studies. The discussion about the interdependence between the values of different aromaticity indices applied to neutral and charged systems in singlet and triplet states is also included. This journal is © the Owner Societies 2011

Identification and quantification of phencyclidine pyrolysis products formed during smoking.

PubMed

Lue, L P; Scimeca, J A; Thomas, B F; Martin, B R

1986-01-01

As a result of frequent phencyclidine (PCP) abuse, pyrolysis studies were conducted to further investigate its fate during smoking. Marijuana placebo cigarettes were impregnated with 3H-PCP X HCI and burned under conditions simulating smoking. Mainstream smoke was passed through glass wool filters as well as acidic and basic traps. Approximately 90% of the starting material could be accounted for in the first glass wool trap and cigarette holder. HPLC and GC/MS analysis of methanol extracts of these glass wool traps revealed the presence of 1-phenyl-1-cyclohexene (47% of the starting material) greater than PCP (40%) greater than piperidine (15%) greater than N-acetylpiperidine (9%). It was not possible to fully account for the remainder of the piperidine moiety. It has been reported that at high temperatures PCP is converted to numerous polynuclear aromatic compounds which include styrene, alpha-methylstyrene, naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, biphenyl, cyclohexylbenzene, acenaphthene, phenanthrene, and anthracene. These compounds were not formed from PCP under smoking conditions.

Predicting the equilibrium solubility of solid polycyclic aromatic hydrocarbons and dibenzothiophene using a combination of MOSCED plus molecular simulation or electronic structure calculations

NASA Astrophysics Data System (ADS)

Phifer, Jeremy R.; Cox, Courtney E.; da Silva, Larissa Ferreira; Nogueira, Gabriel Gonçalves; Barbosa, Ana Karolyne Pereira; Ley, Ryan T.; Bozada, Samantha M.; O'Loughlin, Elizabeth J.; Paluch, Andrew S.

2017-06-01

Methods to predict the equilibrium solubility of non-electrolyte solids are important for the design of novel separation processes. Here we demonstrate how conventional molecular simulation free energy calculations or electronic structure calculations in a continuum solvent, here SMD or SM8, can be used to predict parameters for the MOdified Separation of Cohesive Energy Density (MOSCED) method. The method is applied to the solutes naphthalene, anthracene, phenanthrene, pyrene and dibenzothiophene, compounds of interested to the petroleum industry and for environmental remediation. Adopting the melting point temperature and enthalpy of fusion of these compounds from experiment, we are able to predict equilibrium solubilities. Comparing to a total of 422 non-aqueous and 193 aqueous experimental solubilities, we find the proposed method is able to well correlate the data. The use of MOSCED is additionally advantageous as it is a solubility parameter-based method useful for intuitive solvent selection and formulation.

Recyclable nanoscale zero-valent iron-based magnetic polydopamine coated nanomaterials for the adsorption and removal of phenanthrene and anthracene

PubMed Central

Li, Jing; Zhou, Qingxiang; Liu, Yongli; Lei, Man

2017-01-01

Abstract In this study, nanoscale zero-valent iron nanoparticles (NZVIs) were coated with silica and polydopamine using a two-step process. The coated nanoparticles were applied as adsorbents for removal of two common polycyclic aromatic hydrocarbons pollutants, phenanthrene (PHE) and anthracene (ANT) from aqueous system. Adsorption kinetics followed a pseudo-second-order model. Isotherms and thermodynamics were investigated and the results indicated that the adsorption process fit best to the Freundlich model and exhibited the characteristics of an exothermal physical adsorption process. Owing to their superparamagnetic characteristics and stability, these adsorbents could be easily collected and recycled for reuse. PMID:28179954

JPRS Report, Science & Technology USSR: Physics & Mathematics.

DTIC Science & Technology

1991-01-17

Irregularities on Readings of Local Work Function by Scanning Tunneling Microscope [A.O. Golubok, N.A. Tarasov, et al; PISMA V ZHURNAL TEKHNICHESKOY...constant. The substances tested (anthracene, phenanthrene, naphthacene, triphenylene, p- terphenyl, pentacene , benzo(def)phenanthrene, benzo(ghl...in nucleus-nucleus collisions are analyzed, considering that local thermodynamic equilibrium establishes itself after two or three collisions to be

Heterologous Expression of Polycyclic Aromatic Hydrocarbon Ring-Hydroxylating Dioxygenase Genes from a Novel Pyrene-Degrading Betaproteobacterium

PubMed Central

Hu, Jing; Aitken, Michael D.

2012-01-01

A betaproteobacterium within the family Rhodocyclaceae previously identified as a pyrene degrader via stable-isotope probing (SIP) of contaminated soil (designated pyrene group 1 or PG1) was cultivated as the dominant member of a mixed bacterial culture. A metagenomic library was constructed, and the largest contigs were analyzed for genes associated with polycyclic aromatic hydrocarbon (PAH) metabolism. Eight pairs of genes with similarity to the α- and β-subunits of ring-hydroxylating dioxygenases (RHDs) associated with aerobic bacterial PAH degradation were identified and linked to PG1 through PCR analyses of a simplified enrichment culture. In tandem with a ferredoxin and reductase found in close proximity to one pair of RHD genes, six of the RHDs were cloned and expressed in Escherichia coli. Each cloned RHD was tested for activity against nine PAHs ranging in size from two to five rings. Despite differences in their predicted protein sequences, each of the six RHDs was capable of transforming phenanthrene and pyrene. Three RHDs could additionally transform naphthalene and fluorene, and these genotypes were also associated with the ability of the E. coli constructs to convert indole to indigo. Only one of the six cloned RHDs was capable of transforming anthracene and benz[a]anthracene. None of the tested RHDs were capable of significantly transforming fluoranthene, chrysene, or benzo[a]pyrene. PMID:22427500

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.

Microplastics Reduce Short-Term Effects of Environmental Contaminants. Part II: Polyethylene Particles Decrease the Effect of Polycyclic Aromatic Hydrocarbons on Microorganisms.

PubMed

Kleinteich, Julia; Seidensticker, Sven; Marggrander, Nikolaj; Zarfl, Christiane

2018-02-07

Microplastic particles in terrestrial and aquatic ecosystems are currently discussed as an emerging persistent organic pollutant and as acting as a vector for hydrophobic chemicals. Microplastic particles may ultimately deposit and accumulate in soil as well as marine and freshwater sediments where they can be harmful to organisms. In this study, we tested the sensitivity of natural freshwater sediment bacterial communities (by genetic fingerprint) to exposure to microplastics (polyethylene, 2 and 20 mg/g sediment) and microplastics loaded with polycyclic aromatic hydrocarbons (PAHs, phenanthrene and anthracene), using a laboratory-based approach. After two weeks of incubation, the bacterial community composition from an unpolluted river section was altered by high concentrations of microplastics, whereas the community downstream of a wastewater treatment plant remained unchanged. Low microplastic concentrations loaded with phenanthrene or anthracene induced a less pronounced response in the sediment communities compared to the same total amount of phenanthrene or anthracene alone. In addition, biodegradation of the PAHs was reduced. This study shows, that microplastic can affect bacterial community composition in unpolluted freshwater sediments. Moreover, the results indicate that microplastics can serve as a vehicle for hydrophobic pollutants but bioavailability of the latter is reduced by the sorption to microplastics.

Microplastics Reduce Short-Term Effects of Environmental Contaminants. Part II: Polyethylene Particles Decrease the Effect of Polycyclic Aromatic Hydrocarbons on Microorganisms

PubMed Central

Kleinteich, Julia; Marggrander, Nikolaj; Zarfl, Christiane

2018-01-01

Microplastic particles in terrestrial and aquatic ecosystems are currently discussed as an emerging persistent organic pollutant and as acting as a vector for hydrophobic chemicals. Microplastic particles may ultimately deposit and accumulate in soil as well as marine and freshwater sediments where they can be harmful to organisms. In this study, we tested the sensitivity of natural freshwater sediment bacterial communities (by genetic fingerprint) to exposure to microplastics (polyethylene, 2 and 20 mg/g sediment) and microplastics loaded with polycyclic aromatic hydrocarbons (PAHs, phenanthrene and anthracene), using a laboratory-based approach. After two weeks of incubation, the bacterial community composition from an unpolluted river section was altered by high concentrations of microplastics, whereas the community downstream of a wastewater treatment plant remained unchanged. Low microplastic concentrations loaded with phenanthrene or anthracene induced a less pronounced response in the sediment communities compared to the same total amount of phenanthrene or anthracene alone. In addition, biodegradation of the PAHs was reduced. This study shows, that microplastic can affect bacterial community composition in unpolluted freshwater sediments. Moreover, the results indicate that microplastics can serve as a vehicle for hydrophobic pollutants but bioavailability of the latter is reduced by the sorption to microplastics. PMID:29414906

Influence of the Reaction Temperature on the Nature of the Active and Deactivating Species During Methanol-to-Olefins Conversion over H-SAPO-34

PubMed Central

2017-01-01

The selectivity toward lower olefins during the methanol-to-olefins conversion over H-SAPO-34 at reaction temperatures between 573 and 773 K has been studied with a combination of operando UV–vis diffuse reflectance spectroscopy and online gas chromatography. It was found that the selectivity toward propylene increases in the temperature range of 573–623 K, while it decreases in the temperature range of 623–773 K. The high degree of incorporation of olefins, mainly propylene, into the hydrocarbon pool affects the product selectivity at lower reaction temperatures. The nature and dynamics of the active and deactivating hydrocarbon species with increasing reaction temperature were revealed by a non-negative matrix factorization of the time-resolved operando UV–vis diffuse reflectance spectra. The active hydrocarbon pool species consist of mainly highly methylated benzene carbocations at temperatures between 573 and 598 K, of both highly methylated benzene carbocations and methylated naphthalene carbocations at 623 K, and of only methylated naphthalene carbocations at temperatures between 673 and 773 K. The operando spectroscopy results suggest that the nature of the active species also influences the olefin selectivity. In fact, monoenylic and highly methylated benzene carbocations are more selective to the formation of propylene, whereas the formation of the group of low methylated benzene carbocations and methylated naphthalene carbocations at higher reaction temperatures (i.e., 673 and 773 K) favors the formation of ethylene. At reaction temperatures between 573 and 623 K, catalyst deactivation is caused by the gradual filling of the micropores with methylated naphthalene carbocations, while between 623 and 773 K the formation of neutral poly aromatics and phenanthrene/anthracene carbocations are mainly responsible for catalyst deactivation, their respective contribution increasing with increasing reaction temperature. Methanol pulse experiments at different temperatures demonstrate the dynamics between methylated benzene and methylated naphthalene carbocations. It was found that methylated naphthalene carbocations species are deactivating and block the micropores at low reaction temperatures, while acting as the active species at higher reaction temperatures, although they give rise to the formation of extended hydrocarbon deposits. PMID:28824823

Polycyclic Aromatic Hydrocarbons In Edible Mushrooms from Niger Delta, Nigeria: Carcinogenic and Non-Carcinogenic Health Risk Assessment

PubMed

Igbiri, Sorbari; Udowelle, Nnaemeka Arinze; Ekhator, Osazuwa Clinton; Asomugha, Rose Ngozi; Igweze, Zelinjo Nkeiruka; Orisakwe, Orish Ebere

2017-02-01

In the oil-rich Niger Delta, hydrocarbon pollution and oil spillages, gas flaring and sundry anthropogenic activities constitute sources of polycyclic aromatic hydrocarbons (PAHs), with food contamination playing a major role in human exposure. In this study we assessed PAH levels in wild and cultivated edible mushroom species consumed by the general population from the oil producing Niger Delta, Nigeria. The concentrations of USEPA-16 PAHs were determined by gas chromatography and carcinogenic and non-carcinogenic health risks were calculated. The concentrations of USEPA-16 PAHs ranged from 0.02 mg/kg – 3.37 mg/kg. The dietary intake of carcinogenic and non-carcinogenic USEPA-16 PAHs (Naphthalene, Acenaphthylene, Acenaphthene, Anthracene, Phenanthrene, Flourene, Flouranthene, Pyrene, Benzo[a]Anthracene, Chrysene, Benzo[a]Pyrene, Benzo[b]Flouranthene, Benzo[K]Flouranthene, Benzo[g,h,i] Perylene, Dibenz[a,h]Anthracene and Ideno[1,2,3-cd]Pyrene) for adults, adolescents and seniors ranged from 0.00 – 0.05 mg/kg/day, 0.00 – 0.06 mg/kg/day and 0.00 – 0.07 mg/kg/day. The BaPeq ranged from 0.02 – 2.76 with margin of exposure MOE values of BaP ranging from 3,500,000 to 700,000, 3,500,000 and 3,500,000 to 7,000,000 for adults, adolescents and seniors indicating very insignificant health risk. The incremental lifetime cancer risk was within the safe range of 1.56x10-8 – 1.73x10-6 with the highest calculated risk found for wild Pleurotus ostreatus mushroom species from the study area. Creative Commons Attribution License

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

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

PubMed

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

1995-10-01

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.

Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Hui; Energy Research Institute, University of Leeds, Leeds LS2 9JT; Wu, Chunfei, E-mail: c.wu@leeds.ac.uk

2015-02-15

Highlights: • PAH from pyrolysis of 9 MSW fractions was investigated. • Pyrolysis of plastics released more PAH than that of biomass. • Naphthalene was the most abundant PAH in the tar. • The mechanism of PAH release from biomass and plastics was proposed. - Abstract: The formation of 2–4 ring polycyclic aromatic hydrocarbons (PAH) from the pyrolysis of nine different municipal solid waste fractions (xylan, cellulose, lignin, pectin, starch, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) were investigated in a fixed bed furnace at 800 °C. The mass distribution of pyrolysis was also reported. Themore » results showed that PS generated the most total PAH, followed by PVC, PET, and lignin. More PAH were detected from the pyrolysis of plastics than the pyrolysis of biomass. In the biomass group, lignin generated more PAH than others. Naphthalene was the most abundant PAH, and the amount of 1-methynaphthalene and 2-methynaphthalene was also notable. Phenanthrene and fluorene were the most abundant 3-ring PAH, while benzo[a]anthracene and chrysene were notable in the tar of PS, PVC, and PET. 2-ring PAH dominated all tar samples, and varied from 40 wt.% to 70 wt.%. For PS, PET and lignin, PAH may be generated directly from the aromatic structure of the feedstock.« less

Aromatic hydrocarbon biodegradation activates neutral lipid biosynthesis in oleaginous yeast.

PubMed

Deeba, Farha; Pruthi, Vikas; Negi, Yuvraj S

2018-05-01

In this study, the biodegradation ability of oleaginous yeast Cryptococcus psychrotolerans IITRFD for aromatic hydrocarbons (AHs) was investigated. It was found to completely degrade range of AHs such as 1 g/L phenol, 0.75 g/L naphthalene, 0.50 g/L anthracene and 0.50 g/L pyrene with lipid productivity (g/L/h) of 0.0444, 0.0441, 0.0394 and 0.0383, respectively. This work demonstrated the ring cleavage pathways of AHs by this yeast which follow ortho route for phenol and naphthalene while meta route for anthracene and pyrene degradation. The end products generated during biodegradation of AHs are feed as precursors for de novo triacylglycerols (TAG) biosynthesis pathway of oleaginous yeast. A high quantity of lipid content (46.54%) was observed on phenol as compared to lipid content on naphthalene (46.38%), anthracene (44.97%) and pyrene (44.16%). The lipid profile revealed by GC-MS analysis shows elevated monounsaturated fatty acid (MUFA) content with improved biodiesel quality. Copyright © 2018 Elsevier Ltd. All rights reserved.

Energy transfer of highly vibrationally excited phenanthrene and diphenylacetylene.

PubMed

Hsu, Hsu Chen; Tsai, Ming-Tsang; Dyakov, Yuri; Ni, Chi-Kung

2011-05-14

The energy transfer between Kr atoms and highly vibrationally excited, rotationally cold phenanthrene and diphenylacetylene in the triplet state was investigated using crossed-beam/time-of-flight mass spectrometer/time-sliced velocity map ion imaging techniques. Compared to the energy transfer between naphthalene and Kr, energy transfer between phenanthrene and Kr shows a larger cross-section for vibrational to translational (V → T) energy transfer, a smaller cross-section for translational to vibrational and rotational (T → VR) energy transfer, and more energy transferred from vibration to translation. These differences are further enlarged in the comparison between naphthalene and diphenylacetylene. In addition, less complex formation and significant increases in the large V → T energy transfer probabilities, termed supercollisions in diphenylacetylene and Kr collisions were observed. The differences in the energy transfer between these highly vibrationally excited molecules are attributed to the low-frequency vibrational modes, especially those vibrations with rotation-like wide-angle motions.

The degradation of three-ringed polycyclic aromatic hydrocarbons by wood-inhabiting fungus Pleurotus ostreatus and soil-inhabiting fungus Agaricus bisporus.

PubMed

Pozdnyakova, Natalia; Dubrovskaya, Ekaterina; Chernyshova, Marina; Makarov, Oleg; Golubev, Sergey; Balandina, Svetlana; Turkovskaya, Olga

2018-05-01

The degradation of two isomeric three-ringed polycyclic aromatic hydrocarbons by the white rot fungus Pleurotus ostreatus D1 and the litter-decomposing fungus Agaricus bisporus F-8 was studied. Despite some differences, the degradation of phenanthrene and anthracene followed the same scheme, forming quinone metabolites at the first stage. The further fate of these metabolites was determined by the composition of the ligninolytic enzyme complexes of the fungi. The quinone metabolites of phenanthrene and anthracene produced in the presence of only laccase were observed to accumulate, whereas those formed in presence of laccase and versatile peroxidase were metabolized further to form products that were further included in basal metabolism (e.g. phthalic acid). Laccase can catalyze the initial attack on the PAH molecule, which leads to the formation of quinones, and that peroxidase ensures their further oxidation, which eventually leads to PAH mineralization. A. bisporus, which produced only laccase, metabolized phenanthrene and anthracene to give the corresponding quinones as the dominant metabolites. No products of further utilization of these compounds were detected. Thus, the fungi's affiliation with different ecophysiological groups and their cultivation conditions affect the composition and dynamics of production of the ligninolytic enzyme complex and the completeness of PAH utilization. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Human biomonitoring of polycyclic aromatic hydrocarbonsand metals in the general population residing near the municipal solid waste incinerator of Modena, Italy.

PubMed

Gatti, Maria Giulia; Bechtold, Petra; Campo, Laura; Barbieri, Giovanna; Quattrini, Giulia; Ranzi, Andrea; Sucato, Sabrina; Olgiati, Luca; Polledri, Elisa; Romolo, Michael; Iacuzio, Laura; Carrozzi, Giuliano; Lauriola, Paolo; Goldoni, Carlo A; Fustinoni, Silvia

2017-11-01

A cross-sectional biomonitoring study was carried out to investigate exposure to incinerator emission in relation to the body burden of selected biomarkers in the population living around the plant. Approximately 500 people, aged 18-69 yrs, living within 4 km from the incinerator were randomly selected form the population register. Exposure was measured through fall-out maps of particulate matter (PM), used as tracer for incinerator emissions. Ten metabolized polycyclic aromatic hydrocarbons (PAHs), from naphthalene to chrysene, 1-hydroxypyrene and twelve metals (Cd, Cr, Cu, Hg, Ni, Pb, Ni, Zn, V, Tl, As, Sn) were measured in spot urine samples. Confounders, such as diet, smoking, traffic, occupation and personal characteristics were assessed by questionnaires and objective measurements, and included into multivariate linear regression models. Metal concentrations in urine were in line with or higher than Italian reference limits, besides Cr and V with more than twofold concentrations. Metal levels did not show clear association to exposure categories. Most abundant PAHs were naphthalene (median 26.2 ng/L) and phenanthrene (7.4 ng/L). All PAHs, but benz[a]anthracene and 1-hydroxypyrene, were found in more than 52% of samples, and included in regression models. Significant associations between urinary PAHs and exposure were found, strong for fluorene, and weaker for naphthalene, fluoranthene and pyrene. Results were confirmed by sensitivity analyses. Correlation with variables reported in literature were observed. The study indicates that the emissions were very low and highlights that specific urinary PAHs provided useful information about the internal dose arising from incinerator emission. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 464.31 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (dichloromethane) 55. naphthalene 64. pentachlorophenol 65. phenol 66. bis(2-ethylhexyl)phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72. benzo (a)anthracene (1,2...-ethylhexyl) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 72. benzo (a)anthracene (1,2...

Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)

PubMed Central

Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

2012-01-01

Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality. PMID:23185628

RECOIL LABELING OF ORGANIC COMPOUNDS (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oae, S.; Hamada, M.; Otsuji, Y.

1963-01-01

The results of C/sup 14/-labeling under neutron irradiation of two groups of compounds are reported: (1) naphthalene, phenanthrene, and anthracene in an attempt to determine whether or not high energy C/sup 14/ fragments formed by nuclear recoil would favor or discriminate against any particular position in product formations; (2) pseudoephedrine, 2-amino-pyrimidine, and 3,6- dihydroxypyridazine as complex nitrogen-containing compounds. These samples were irradiated with thermal neutrons obtained from a pile. To determine the radiochemical yields and the relative ratios of the C/sup 14/ distributions in the respective compounds, the samples were purified radlochemically and were degraded chemically. The results deduced frommore » the experimental data are the following: (1) higher distribution of C/sup 14/ was found in the positions where the localizations of electrons are known to be higher; (2) the re-entry of C/sup 14/ into angular positions was very small; (3) the difference of phase affected the yield but not the distribution of C/sup 14/ in the products; (4) the relatively complex compounds could be labeled directly by this method. (A.G.W.)« less

Contamination of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and plants of mangrove swamps in Shenzhen, China.

PubMed

Li, Fenglan; Zeng, Xiaokang; Yang, Junda; Zhou, Kai; Zan, Qijie; Lei, Anping; Tam, Nora F Y

2014-08-30

The concentrations of 16 individual and total polycyclic aromatic hydrocarbons (∑PAHs) in sediments, roots and leaves of three mangrove swamps in Shenzhen, China, namely Futian, Baguang and Waterlands, were determined. The mean concentration of ∑PAHs in Futian (4480 ng g(-1)) was significantly higher than that in Baguang (1262 ng g(-1)) and Waterlands (2711 ng g(-1)). Among the 16 PAHs, the concentration of naphthalene was the highest. Based on the ratios of phenanthrene/anthracene and fluoranthene/pyrene, PAHs in Futian and Waterlands came from petrogenic and pyrolytic sources, while Baguang was mainly from pyrolytic. More PAHs were accumulated in leaves, as reflected by its higher mean concentration of ∑PAHs (3697 ng g(-1)) and bioconcentration factor of PAHs (BCF) (>1.5) than that in roots. The BCF values in plants collected from Futian were significantly higher than that from Waterlands. These results indicated that more attention should be paid to the PAH contamination in Futian. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions.

PubMed

Zhou, Hui; Wu, Chunfei; Onwudili, Jude A; Meng, Aihong; Zhang, Yanguo; Williams, Paul T

2015-02-01

The formation of 2-4 ring polycyclic aromatic hydrocarbons (PAH) from the pyrolysis of nine different municipal solid waste fractions (xylan, cellulose, lignin, pectin, starch, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) were investigated in a fixed bed furnace at 800 °C. The mass distribution of pyrolysis was also reported. The results showed that PS generated the most total PAH, followed by PVC, PET, and lignin. More PAH were detected from the pyrolysis of plastics than the pyrolysis of biomass. In the biomass group, lignin generated more PAH than others. Naphthalene was the most abundant PAH, and the amount of 1-methynaphthalene and 2-methynaphthalene was also notable. Phenanthrene and fluorene were the most abundant 3-ring PAH, while benzo[a]anthracene and chrysene were notable in the tar of PS, PVC, and PET. 2-ring PAH dominated all tar samples, and varied from 40 wt.% to 70 wt.%. For PS, PET and lignin, PAH may be generated directly from the aromatic structure of the feedstock. Copyright © 2014 Elsevier Ltd. All rights reserved.

Examining spatial patterns in polycyclic aromatic compounds measured in stream macroinvertebrates near a small subarctic oil and gas operation.

PubMed

Korosi, J B; Eickmeyer, D C; Chin, K S; Palmer, M J; Kimpe, L E; Blais, J M

2016-03-01

The Cameron River runs through a small, remote petrochemical development in the Cameron Hills (Northwest Territories, Canada). In order to evaluate the exposure of aquatic biota to contaminants from oil and gas activities, we measured polycyclic aromatic compounds (PACs) in macroinvertebrates collected from sites and tributaries along the Cameron River, including upstream and downstream of the development, and sites located near drilled wells (developed). Macroinvertebrate tissue PAC burdens ranged from 0.2-2.8 μg g(-1) lipid for unsubstituted compounds, and from 4.2-63.2 μg g(-1) lipid for alkylated compounds, relatively low compared to similar studies from more industrialized regions in North America. There was no significant difference in tissue PAC burdens between upstream, downstream, or developed sites (p = 0.12), although alkyl PACs in five out of seven developed sites were higher than the regional average. Petrogenic PACs were dominant in most samples, including alkyl fluorines, alkyl phenanthrene/anthracenes, and alkyl dibenzothiophenes. Minimal changes in PAC composition in macroinvertebrate tissues were detected along the Cameron River, with the exception of the two sites furthest downstream that had high concentrations of C3-C4 naphthalene. Overall, our results suggest that oil and gas development in the Cameron Hills has not resulted in substantial increases in PAC bioaccumulation in stream macroinvertebrates, although the potential that alkyl naphthalenes are being transported downstream from the development warrants further attention.

The phn Genes of Burkholderia sp. Strain RP007 Constitute a Divergent Gene Cluster for Polycyclic Aromatic Hydrocarbon Catabolism

PubMed Central

Laurie, Andrew D.; Lloyd-Jones, Gareth

1999-01-01

Cloning and molecular ecological studies have underestimated the diversity of polycyclic aromatic hydrocarbon (PAH) catabolic genes by emphasizing classical nah-like (nah, ndo, pah, and dox) sequences. Here we report the description of a divergent set of PAH catabolic genes, the phn genes, which although isofunctional to the classical nah-like genes, show very low homology. This phn locus, which contains nine open reading frames (ORFs), was isolated on an 11.5-kb HindIII fragment from phenanthrene-degrading Burkholderia sp. strain RP007. The phn genes are significantly different in sequence and gene order from previously characterized genes for PAH degradation. They are transcribed by RP007 when grown at the expense of either naphthalene or phenanthrene, while in Escherichia coli the recombinant phn enzymes have been shown to be capable of oxidizing both naphthalene and phenanthrene to predicted metabolites. The locus encodes iron sulfur protein α and β subunits of a PAH initial dioxygenase but lacks the ferredoxin and reductase components. The dihydrodiol dehydrogenase of the RP007 pathway, PhnB, shows greater similarity to analogous dehydrogenases from described biphenyl pathways than to those characterized from naphthalene/phenanthrene pathways. An unusual extradiol dioxygenase, PhnC, shows no similarity to other extradiol dioxygenases for naphthalene or biphenyl oxidation but is the first member of the recently proposed class III extradiol dioxygenases that is specific for polycyclic arene diols. Upstream of the phn catabolic genes are two putative regulatory genes, phnR and phnS. Sequence homology suggests that phnS is a LysR-type transcriptional activator and that phnR, which is divergently transcribed with respect to phnSFECDAcAdB, is a member of the ς54-dependent family of positive transcriptional regulators. Reverse transcriptase PCR experiments suggest that this gene cluster is coordinately expressed and is under regulatory control which may involve PhnR and PhnS. PMID:9882667

Acute photo-induced toxicity and toxicokinetics of single compounds and mixtures of polycyclic aromatic hydrocarbons in zebrafish.

PubMed

Willis, Alison M; Oris, James T

2014-09-01

The present study examined photo-induced toxicity and toxicokinetics for acute exposure to selected polycyclic aromatic hydrocarbons (PAHs) in zebrafish. Photo-enhanced toxicity from co-exposure to ultraviolet (UV) radiation and PAHs enhanced the toxicity and exhibited toxic effects at PAH concentrations orders of magnitude below effects observed in the absence of UV. Because environmental exposure to PAHs is usually in the form of complex mixtures, the present study examined the photo-induced toxicity of both single compounds and mixtures of PAHs. In a sensitive larval life stage of zebrafish, acute photo-induced median lethal concentrations (LC50s) were derived for 4 PAHs (anthracene, pyrene, carbazole, and phenanthrene) to examine the hypothesis that phototoxic (anthracene and pyrene) and nonphototoxic (carbazole and phenanthrene) pathways of mixtures could be predicted from single exposures. Anthracene and pyrene were phototoxic as predicted; however, carbazole exhibited moderate photo-induced toxicity and phenanthrene exhibited weak photo-induced toxicity. The toxicity of each chemical alone was used to compare the toxicity of mixtures in binary, tertiary, and quaternary combinations of these PAHs, and a predictive model for environmental mixtures was generated. The results indicated that the acute toxicity of PAH mixtures was additive in phototoxic scenarios, regardless of the magnitude of photo-enhancement. Based on PAH concentrations found in water and circumstances of high UV dose to aquatic systems, there exists potential risk of photo-induced toxicity to aquatic organisms. © 2014 SETAC.

Tissue distribution and depuration kinetics of waterborne 14C-labeled light PAHs in mummichog (Fundulus heteroclitus).

PubMed

Valdez Domingos, F X; Oliveira Ribeiro, C A; Pelletier, É; Rouleau, C

2011-04-01

Light polycyclic aromatic hydrocarbons (PAHs) of petrogenic origin are commonly found in estuaries and coastal areas. Though they are known to be toxic to fish, little is known about their uptake and tissue distribution. This paper reports on the results of a study on uptake, elimination, and tissue distribution of three waterborne 14C-labeled PAHs in the mummichog, Fundulus heteroclitus, using whole-body autoradiography. After a 24 h exposure to 1 μCi·L(-1) of 14C-naphthalene, 14C-1-naphthol, and 14C-phenanthrene, fish were transferred to clean water and tissue distribution examined after 0, 1, 3, 7, 14, and 21 days of depuration. All compounds were readily accumulated by fish and were also rapidly eliminated (t0.5 range=1.1 to 3.0 days). Most of the radioactivity in naphthalene- and phenanthrene-treated fish was found in gall bladder≫liver>intestinal lumen. In naphthol-exposed fish, an important labeling of some brain areas was observed. Brain of naphthalene-exposed fish was also labeled after 24 h depuration, indicating that exposure to naphthalene may result in metabolite accumulation in the brain. This is the first study showing that naphthalene, naphthol, and/or unidentified metabolite(s) can accumulate in brain tissues, which may impair normal brain function.

Contrasting effects of a nonionic surfactant on the biotransformation of polycyclic aromatic hydrocarbons to cis-dihydrodiols by soil bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, C.C.R.; Boyd, D.R.; Hempenstall, F.

The biotransformation of the polycyclic aromatic hydrocarbons (PAHs) naphthalene and phenanthrene was investigated by using two dioxygenase-expressing bacteria, Pseudomonas sp. strain 9816/11 and Sphingomonas yanoikuyae B8/36, under conditions which facilitate mass-transfer limited substrate oxidation. Both of these strains are mutants that accumulate cis-dihydrodiol metabolites under the reaction conditions used. The effects of the nonpolar solvent 2,2,4,4,6,8,8-heptamethylnonane (HMN) and the nonionic surfactant Triton X-100 on the rate of accumulation of these metabolites were determined. HMN increased the rate of accumulation of metabolites for both microorganisms, with both substrates. The enhancement effect was most noticeable with phenanthrene, which has a lower aqueousmore » solubility than naphthalene. Triton X-100 increased the rate of oxidation of the PAHs with strain 9816/11 with the effect being most noticeable when phenanthrene was used as a substrate. However, the surfactant inhibited the biotransformation of both naphthalene and phenanthrene with strain B8/36 under the same conditions. The observation that a nonionic surfactant could have such contrasting effects on PAH oxidation by different bacteria, which are known to be important for the degradation of these compounds in the environment, may explain why previous research on the application of the surfactants to PAH bioremediation has yielded inconclusive results. The surfactant inhibited growth of the wild-type strain S. yanoikuyae B1 on aromatic compounds but did not inhibit B8/36 dioxygenase enzyme activity in vitro.« less

Identification of petroleum hydrocarbons using a reduced number of PAHs selected by Procrustes rotation.

PubMed

Fernández-Varela, R; Andrade, J M; Muniategui, S; Prada, D; Ramírez-Villalobos, F

2010-04-01

Identifying petroleum-related products released into the environment is a complex and difficult task. To achieve this, polycyclic aromatic hydrocarbons (PAHs) are of outstanding importance nowadays. Despite traditional quantitative fingerprinting uses straightforward univariate statistical analyses to differentiate among oils and to assess their sources, a multivariate strategy based on Procrustes rotation (PR) was applied in this paper. The aim of PR is to select a reduced subset of PAHs still capable of performing a satisfactory identification of petroleum-related hydrocarbons. PR selected two subsets of three (C(2)-naphthalene, C(2)-dibenzothiophene and C(2)-phenanthrene) and five (C(1)-decahidronaphthalene, naphthalene, C(2)-phenanthrene, C(3)-phenanthrene and C(2)-fluoranthene) PAHs for each of the two datasets studied here. The classification abilities of each subset of PAHs were tested using principal components analysis, hierarchical cluster analysis and Kohonen neural networks and it was demonstrated that they unraveled the same patterns as the overall set of PAHs. (c) 2009 Elsevier Ltd. All rights reserved.

Comment on: Negative ions, molecular electron affinity and orbital structure of cata-condensed polycyclic aromatic hydrocarbons by Rustem V. Khatymov, Mars V. Muftakhov and Pavel V. Shchukin.

PubMed

Chen, Edward S; Chen, Edward C M

2018-02-15

The anion mass spectral lifetimes for several aromatic hydrocarbons reported in the subject article were related to significantly different electron affinities. The different values are rationalized using negative ion mass spectral data. Electron affinities for polycyclic aromatic hydrocarbons are reported from the temperature dependence of unpublished electron capture detector data. These are compared with published values and the largest values are assigned to the ground state. The ground state adiabatic electron affinities: (eV) pentacene, 1.41 (3); tetracene, 1.058 (5); benz(a)pyrene, 0.82 (4); benz(a) anthracene, 0.69 (2) anthracene, 0.68 (2); and pyrene, 0.59 (1) are used to assign excited state adiabatic electron affinities: (eV) tetracene: 0.88 (4); anthracene 0.53 (1); pyrene, 0.41 (1); benz(a)anthracene, 0.39 (10); chrysene, 0.32 (1); and phenanthrene, 0.12 (2) and ground state adiabatic electron affinities: (eV) dibenz(a,j)anthracene, 0.69 (3); dibenz(a,h)anthracene, 0.68 (3); benz(e)pyrene, 0.60 (3); and picene, 0.59 (3) from experimental data. The lifetime of benz(a)pyrene is predicted to be larger than 150 μs and for benzo(c)phenanthrene and picene about 40 μs, from ground state adiabatic electron affinities. The assignments of adiabatic electron affinities of aromatic hydrocarbons determined from electron capture detector and mass spectrometric data to ground and excited states are supported by constant electronegativities. A set of consistent ground state adiabatic electron affinities for 15 polycyclic aromatic hydrocarbons is related to lifetimes from the subject article. Copyright © 2017 John Wiley & Sons, Ltd.

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 43 to 420 micrograms per liter. Sediment elutriate samples were toxic to Ceriodaphnia dubta, Pimephales promelas, Photobacterium phosphoreum, and Salenastrum capricornulum.

Carbon nanorings with inserted acenes: Breaking symmetry in excited state dynamics

DOE PAGES

Franklin-Mergarejo, R.; Alvarez, D. Ondarse; Tretiak, S.; ...

2016-08-10

Conjugated cycloparaphenylene rings have unique electronic properties being the smallest segments of carbon nanotubes. Their conjugated backbones support delocalized electronic excitations, which dynamics is strongly influenced by cyclic geometry. Here we present a comparative theoretical study of the electronic and vibrational energy relaxation and redistribution in photoexcited cycloparaphenylene carbon nanorings with inserted naphthalene, anthracene, and tetracene units using non-adiabatic excited-state molecular dynamics simulations. Calculated excited state structures reflect modifications of optical selection rules and appearance of low-energy electronic states localized on the acenes due to gradual departure from a perfect circular symmetry. After photoexcitation, an ultrafast electronic energy relaxation tomore » the lowest excited state is observed on the time scale of hundreds of femtoseconds in all molecules studied. Concomitantly, the efficiency of the exciton trapping in the acene raises when moving from naphthalene to anthracene and to tetracene, being negligible in naphthalene, and ~60% and 70% in anthracene and tetracene within the first 500 fs after photoexcitation. Observed photoinduced dynamics is further analyzed in details using induced molecular distortions, delocatization properties of participating electronic states and non-adiabatic coupling strengths. Lastly, our results provide a number of insights into design of cyclic molecular systems for electronic and light-harvesting applications.« less

Phytoremediation of polycyclic aromatic hydrocarbons (PAH) by cv. Crioula: A Brazilian alfalfa cultivar.

PubMed

Alves, Wilber S; Manoel, Evelin A; Santos, Noemi S; Nunes, Rosane O; Domiciano, Giselli C; Soares, Marcia R

2018-07-03

This work aimed to evaluate the phytoremediation capacity of the alfalfa cultivar Crioula in soils contaminated with polycyclic aromatic hydrocarbons (PAHs), primary pollutants with mutagenic and carcinogenic potential. Alfalfa was grown from seed for 40 days on soil amended with anthracene, pyrene, and phenanthrene. Soil and plant tissue was collected for biometric assay, dry mass analysis, and PAH analysis by liquid chromatography. Increased total PAH concentration was associated with decreases in plant biomass, height, and internode length. The Crioula cultivar had a satisfactory phytoremediation effect, reducing total PAH concentration (300 ppm) in the experimental soil by 85% in 20 days, and by more than 95% in 40 days. The PAH showed a tendency to be removed in the temporal order: phenanthrene before pyrene before anthracene, and the removal ratio was influenced by the initial soil concentration of each PAH.

Modeling the Environmental Impacts of Potential Oil Pipeline Leaks in the PÁRAMO Region upon the Water Supply for Quito, Ecuador

NASA Astrophysics Data System (ADS)

Gherasim, J.; Sanjinez Guzman, V.; Emerman, S. H.; Tebbs, K. C.

2017-12-01

The Trans-Ecuadorian Pipeline carries crude oil from oilfields in eastern Ecuador to refineries on the Pacific coast, crossing the Páramo region, an alpine tundra ecosystem within the province of Pichincha, which also serves as the water supply for the capital city of Quito. The objective of this study has been to create a model for predicting the likelihood that the effects of a crude oil spill in the Páramo region would impact the water supply of Quito by comparing the residence times of organic compounds in soil with the time required for microbial degradation. A custom MATLAB script included linear partitioning of multiple organic compounds among the water, air, soil and NAPL phases. The three organic compounds considered were anthracene, benzene, and naphthalene. The relevant soil parameters for the Páramo region were obtained from the ISRIC-WISE Harmonized Global Soil Profile Dataset. The soil organic matter content is a critical parameter that was estimated from a very small number of measurements. Residence time half-lives were calculated for depths of penetration of the initial spill ranging from 0.1-5 m. For a depth of penetration of 1 m, residence time half-lives for benzene, naphthalene and anthracene were 1.5, 23.1 and 247.8 years, respectively. Comparing with typical biodegradation half-lives of 10-730 days for benzene, 1-258 days for naphthalene, and 199-252 days for anthracene, it can be seen that penetration to groundwater and transport to the reservoir that supplies water to Quito is unlikely for naphthalene and anthracene, but is a distinct possibility for benzene. Current modeling involves including the effect of volatilization within the soil and improving the estimates of biodegradation rates within an alpine tundra ecosystem. Further results will be reported at the meeting.

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Trichloroethane methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate...-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2...

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Trichloroethane methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate...-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2...

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

40 CFR 469.12 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate tetrachloroethylene toluene trichloroethylene 2 Chlorophenol 2,4 Dichlorophenol 4 Nitrophenol pentachlorophenol di-n-butyl phthalate anthracene...

40 CFR 469.12 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate tetrachloroethylene toluene trichloroethylene 2 Chlorophenol 2,4 Dichlorophenol 4 Nitrophenol pentachlorophenol di-n-butyl phthalate anthracene...

Yields of Bacterial Cells from Hydrocarbons

PubMed Central

Wodzinski, Richard S.; Johnson, Marvin J.

1968-01-01

A strain of Nocardia and one of Pseudomonas, both isolated on pristane (2,6,10,14-tetramethylpentadecane), gave cell yields of approximately 100% on n-octadecane and pristane. Both organisms grew more rapidly on the n-octadecane than on the pristane. A mixed culture, isolated on 3-methylheptane, whose two components were identified as species of Pseudomonas and of Nocardia, gave approximately 100% cell yields and grew with generation times of about 5 hr on n-heptane, n-octane, and 2-methylheptane. The generation time on 3-methylheptane was 8.6 hr and the cell yield was only 79%. A strain of Pseudomonas isolated from naphthalene enrichments and one from phenanthrene enrichments both gave a cell yield of 50% on naphthalene. The phenanthrene isolate gave a cell yield of 40% on phenanthrene. A Nocardia species isolated on benzene gave a 79% cell yield on benzene. The generation times of the bacteria isolated on aromatic hydrocarbons were related to the solubility of the aromatic hydrocarbons on which they were grown; the more insoluble hydrocarbons gave slower growth. PMID:5726161

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walton, B.T.

In the present study, acute and chronic toxicities of five PAHs (naphthalene, anthracene, benz(a)anthracene, pyrene, and benzo(a)pyrene) and an oxygenated PAH derivative (anthrone) were determined in a terrestrial insect, Acheta domesticus (L.), with emphasis on the influence of route of entry on toxicity. Hexamethylphosphoric triamide (hempa) was included in the chronic tests since this chemosterilant is a useful reference compound for investigations of reproductive effects of chemicals in insects.

Diversity of metabolic capacities among strains degrading polycyclic aromatic hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouchez, M.; Besnaienou, B.; Blanchet, D.

1995-12-31

Strains of Pseudomonas and Rhodococcus genera were isolated for their capacity to use, as a sole carbon and energy source, one of the following polycyclic aromatic hydrocarbons (PAHs): naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLT), and pyrene (PYR). The range of PAHs supporting growth of these pure strains was usually restricted, but several other hydrocarbons were used by Rhodococcus sp. All strains could grow on simple organic acids. Maximal specific growth rates ({mu}{sub max}) of all strains on their PAH growth substrates were determined by respirometry. No clear relationships between {mu}{sub max} values and the molecular weightmore » or water solubility of PAHs were apparent, but Pseudomonas sp. exhibited the highest {mu}{sub max} values. Carbon balances for PAH biodegradation were established. Differences between strains were observed, but high mineralization rates and low production of soluble metabolites were obtained for all PAHs. Bacterial biomass represented 16% to 35% of the carbon consumed. Strain diversity was also apparent in the interactions observed in the degradation of a mixture of two PAHs by individual strains, which often involved inhibition of PAH substrate degradation, with or without cometabolization of the second PAH.« less

Removal efficiency of polycyclic aromatic hydrocarbons and phthalate esters by surface flow wetland in Shunyi district, Beijing

NASA Astrophysics Data System (ADS)

Li, Binghua; Liu, Licai; Han, Li; Yang, Yong

2017-03-01

The surface flow wetland (SFW) system was located on Shunyi district, Beijing. It was built to treat industrial wastewater and domestic sewage, which were looked as its influent. Here sixteen polycyclic aromatic hydrocarbons (PAHs) and six phthalate esters (PAEs) were detected by gas chromatography-mass spectrometry (GC-MS).To determine treatment effect of SFW system, concentrations of targeted compounds in the influent were compared with those in the effluent. Results showed typical compounds of industrial wastewater were naphthalene (NAP), phenanthrene (PHE), dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), and their concentrations were ranged from 122.6 ng.L-1 to 760.6 ng.L-1. However typical compounds of domestic sewage were NAP, anthracene (ANT), PHE, DBP, diethyl phthalate (DEP), DEHP, and their concentrations were ranged from 280 ng.L-1 to 7998.1 ng.L-1. Typical compounds of effluent were NAP, PHE, DBP, DEHP, and their concentrations changed between 4.2 ng.L-1 and 1430.74 ng.L-1. The removal rate of those compounds were 10% ~ 99%, and nineteen compounds removal rate reached above 70%.Therefore, it can be concluded that SFW system had a strong effect on the removal of these compounds.

Biodegradation of low and high molecular weight hydrocarbons in petroleum refinery wastewater by a thermophilic bacterial consortium.

PubMed

Pugazhendi, Arulazhagan; Abbad Wazin, Hadeel; Qari, Huda; Basahi, Jalal Mohammad Al-Badry; Godon, Jean Jacques; Dhavamani, Jeyakumar

2017-10-01

Clean-up of contaminated wastewater remains to be a major challenge in petroleum refinery. Here, we describe the capacity of a bacterial consortium enriched from crude oil drilling site in Al-Khobar, Saudi Arabia, to utilize polycyclic aromatic hydrocarbons (PAHs) as sole carbon source at 60°C. The consortium reduced low molecular weight (LMW; naphthalene, phenanthrene, fluorene and anthracene) and high molecular weight (HMW; pyrene, benzo(e)pyrene and benzo(k)fluoranthene) PAH loads of up to 1.5 g/L with removal efficiencies of 90% and 80% within 10 days. PAH biodegradation was verified by the presence of PAH metabolites and evolution of carbon dioxide (90 ± 3%). Biodegradation led to a reduction of the surface tension to 34 ± 1 mN/m thus suggesting biosurfactant production by the consortium. Phylogenetic analysis of the consortium revealed the presence of the thermophilic PAH degrader Pseudomonas aeruginosa strain CEES1 (KU664514) and Bacillus thermosaudia (KU664515) strain CEES2. The consortium was further found to treat petroleum wastewater in continuous stirred tank reactor with 96 ± 2% chemical oxygen demand removal and complete PAH degradation in 24 days.

First-Principles DFT Studies of the Vibrational Properties of Germanene Nanoflakes

NASA Astrophysics Data System (ADS)

Richardson, Steven; Peroparde, Borja; Andrade, Xavier; Aspuru-Guzik, AláN.

The germanium analogue of graphene, germanene, is a potentially new atomically thin quantum material which theory predicts will possess unique transport and optoelectronic properties. Recently, there have been a number of experimental efforts to successfully grow two-dimensional films of germanene on noble metal substrates using molecular beam epitaxy. In addition to this top-down approach of synthesizing large scale films of germanene, we would like to focus on a bottom-up approach where nanoflakes of germanene could be used as molecular seeds or precursors to grow large films of two-dimensional germanene. A knowledge of their infrared and Raman spectra will be critical for characterizing these germanene nanoflakes in future experiments. In this work we used density-functional theory (DFT) to compute the vibrational spectra of a selected number of lower order germanene nanoflakes (e.g. hexagermabenzene, germa-naphthalene, germa-anthracene, germa-phenanthrene, germa-pyrene, germa-tetracene, and germa-pentacene). Our DFT studies also reveal that these germanene nanoflakes are vibrationally stable with buckling of these molecules from their normal two-dimensional planar forms which exist in graphene nanoflakes. This research is supported by NSF Grant No. DMR-1231319.

Oil-bioremediation potential of two hydrocarbonoclastic, diazotrophic Marinobacter strains from hypersaline areas along the Arabian Gulf coasts.

PubMed

Al-Mailem, D M; Eliyas, M; Radwan, S S

2013-05-01

Two halophilic, hydrocarbonoclastics bacteria, Marinobacter sedimentarum and M. flavimaris, with diazotrophic potential occured in hypersaline waters and soils in southern and northern coasts of Kuwait. Their numbers were in the magnitude of 10(3) colony forming units g(-1). The ambient salinity in the hypersaline environments was between 3.2 and 3.5 M NaCl. The partial 16S rRNA gene sequences of the two strains showed, respectively, 99 and 100% similarities to the sequences in the GenBank. The two strains failed to grow in the absence of NaCl, exhibited best growth and hydrocarbon biodegradation in the presence of 1 to 1.5 M NaCl, and still grew and maintained their hydrocarbonoclastic activity at salinities up to 5 M NaCl. Both species utilized Tween 80, a wide range of individual aliphatic hydrocarbons (C9-C40) and the aromatics benzene, biphenyl, phenanthrene, anthracene and naphthalene as sole sources of carbon and energy. Experimental evidence was provided for their nitrogen-fixation potential. The two halophilic Marinobacter strains successfully mineralized crude oil in nutrient media as well as in hypersaline soil and water microcosms without the use of any nitrogen fertilizers.

Environmental Assessment for Restoration and Stabilization of Eastern Shoreline MacDill AFB, Florida

DTIC Science & Technology

2005-12-01

heal stress , and machinery injuries. Construction would not involve any unique hazards and all construction methods would comply with Occupational...slips, heat stress , and machinery injuries. Construction would not involve any unique hazards, and all construction methods would comply with OSHA...Chloropropane, Benzene, Cumine , Naphthalene, benzo(b)flouranthene, toluene Soils: Benzo(a)pyrene, dibenzo(a,h)anthracene, Pb, naphthalene, toluene Surface

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Online investigations on ozonation products of pyrene and benz[ a]anthracene particles with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer

NASA Astrophysics Data System (ADS)

Gao, Shaokai; Zhang, Yang; Meng, Junwang; Shu, Jinian

The reaction products of ozone with pyrene and benz[ a]anthracene absorbed on azelaic acid particles under the pseudo-first-order reaction conditions have been investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The pyrene and benz[ a]anthracene particles with the initial concentrations of ˜1 mg m -3 are respectively exposed to ˜22 ppm ozone in a reaction chamber with a volume of ˜180 L. The time-of-flight mass spectra of the particulate ozonides are obtained. The assignments of the mass spectra reveal that 4-carboxy-5-phenanthrene-carboxyaldehyde (71%) and hydroxypyrene (23%) are the main solid state ozonides of pyrene, while 2-(2-formyl)phenyl-3-naphthoic acid (35%), hydroxybenz[ a]anthrone (30%), and benz[ a]anthracene-7,12-dione (18%) are the main solid state ozonides of benz[ a]anthracene. The pathways of the ozonations are proposed in the paper.

Temperature-dependent vibrational spectroscopy to study order-disorder transitions in charge transfer complexes

NASA Astrophysics Data System (ADS)

Isaac, Rohan; Goetz, Katelyn P.; Roberts, Drew; Jurchescu, Oana D.; McNeil, L. E.

2018-02-01

Charge-transfer (CT) complexes are a promising class of materials for the semiconductor industry because of their versatile properties. This class of compounds shows a variety of phase transitions, which are of interest because of their potential impact on the electronic characteristics. Here temperature-dependent vibrational spectroscopy is used to study structural phase transitions in a set of organic CT complexes. Splitting and broadening of infrared-active phonons in the complex formed between pyrene and pyromellitic dianhydride (PMDA) confirm the structural transition is of the order-disorder type and complement previous x-ray diffraction (XRD) results. We show that this technique is a powerful tool to characterize transitions, and apply it to a range of binary CT complexes composed of polyaromatic hyrdocarbons (anthracene, perylene, phenanthrene, pyrene, and stilbene) and PMDA. We extend the understanding of transitions in perylene-PMDA and pyrene-PMDA, and show that there are no order-disorder transitions present in anthracene-PMDA, stilbene-PMDA and phenanthrene-PMDA in the temperature range investigated here.

[Polycyclic aromatic hydrocarbons and soluble organic fraction in fine particles from solid fraction of biodiesel exhaust fumes].

PubMed

Szewczyńska, Małgorzata; Pośniak, Małgorzata

2012-01-01

This paper presents the results of investigations into the distribution of fine particles in the biodiesel exhaust fumes (bio-DEP), as well as into the content of polycyclic aromatic hydrocarbons (PAHs) and soluble organic fraction (SOF) in the study fractions. Samples of biodiesel B20 and B40 exhaust combustion fumes were generated at the model station composed of a diesel engine from Diesel TDI 2007 Volkswagen. Sioutas personal cascade impactor (SPCI) with Teflon filters and low-pressure impactor ELIPI (Dekati Low Pressure Impactor) were used for sampling diesel exhaust fine particles. The analysis of PAHs adsorbed on particulate fractions was performed by high performance liquid chromatography with fluorescence detection (HPLC/FL). For the determination of dry residue soluble organic fraction of biodiesel exhaust particles the gravimetric method was used. The combustion exhaust fumes of 100% ON contained mainly naphthalene, acenaphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo(a)anthracene and chrysene, whilst the exhaust of B40-single PAHs of 4 and 5 rings, such as chrysene, benzo(k)fluoranthene, dibenzo (ah)anthracene and benzo(ghi)perylene. The total content of PAHs in diesel exhaust particles averaged 910 ng/m3 for 100% ON and 340 ng/m3 for B40. The concentrations of benzo(a)antarcene were at the levels of 310 ng/m3 (100% ON) and 90 ng/m3 (B40). The investigations indicated that a fraction < 025 microm represents the main component of diesel exhaust particles, regardless of the used fuel. Bioester B 100 commonly added to diesel fuel (ON) causes a reduction of the total particulates emission and thus reduces the amount of toxic substances adsorbed on their surface.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

PAH concentrations simulated with the AURAMS-PAH chemical transport model over Canada and the USA

NASA Astrophysics Data System (ADS)

Galarneau, E.; Makar, P. A.; Zheng, Q.; Narayan, J.; Zhang, J.; Moran, M. D.; Bari, M. A.; Pathela, S.; Chen, A.; Chlumsky, R.

2013-07-01

The off-line Eulerian AURAMS chemical transport model was adapted to simulate the atmospheric fate of seven PAHs: phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene + triphenylene, and benzo[a]pyrene. The model was then run for the year 2002 with hourly output on a~grid covering southern Canada and the continental USA with 42 km horizontal grid spacing. Model predictions were compared to ~ 5000 24 h average PAH measurements from 45 sites, eight of which also provided data on particle/gas partitioning which had been modelled using two alternative schemes. This is the first known regional modelling study for PAHs over a North American domain and the first modelling study at any scale to compare alternative particle/gas partitioning schemes against paired field measurements. Annual average modelled total (gas + particle) concentrations were statistically indistinguishable from measured values for fluoranthene, pyrene and benz[a]anthracene whereas the model underestimated concentrations of phenanthrene, anthracene and chrysene + triphenylene. Significance for benzo[a]pyrene performance was close to the statistical threshold and depended on the particle/gas partitioning scheme employed. On a day-to-day basis, the model simulated total PAH concentrations to the correct order of magnitude the majority of the time. Model performance differed substantially between measurement locations and the limited available evidence suggests that the model spatial resolution was too coarse to capture the distribution of concentrations in densely populated areas. A more detailed analysis of the factors influencing modelled particle/gas partitioning is warranted based on the findings in this study.

40 CFR 464.21 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 464.21 Specialized definitions. For the purpose of this subpart: (a) Total Toxic Organics (TTO). TTO... comprised of a discrete list of toxic organic pollutants for each process segment where it is regulated, as.... chrysene 77. acenaphthylene 78. anthracene 81. phenanthrene 84. pyrene (5) Mold Cooling (§ 464.25(g) and...

40 CFR 464.31 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 464.31 Specialized definitions. For the purpose of this subpart: (a) Total Toxic Organics (TTO). TTO... comprised of a discrete list of toxic organic pollutants for each process segment where it is regulated, as...-benzanthracene) 76. chrysene 77. acenaphthylene 78. anthracene 80. fluorene 81. phenanthrene 84. pyrene (5) Mold...

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 occupational exposures to PAH mixtures. Main Messages Urinary naphthalene and phenanthrene are promising surrogates for occupational exposures to PAHs. Policy Implications Measurement of urinary naphthalene and phenanthrene could simplify the assessment of occupational exposures to PAHs. PMID:19017700

Biochemical studies on a versatile esterase that is most catalytically active with polyaromatic esters

PubMed Central

Martínez-Martínez, Mónica; Lores, Iván; Peña-García, Carlina; Bargiela, Rafael; Reyes-Duarte, Dolores; Guazzaroni, María-Eugenia; Peláez, Ana Isabel; Sánchez, Jesús; Ferrer, Manuel

2014-01-01

Herein, we applied a community genomic approach using a naphthalene-enriched community (CN1) to isolate a versatile esterase (CN1E1) from the α/β-hydrolase family. The protein shares low-to-medium identity (≤ 57%) with known esterase/lipase-like proteins. The enzyme is most active at 25–30°C and pH 8.5; it retains approximately 55% of its activity at 4°C and less than 8% at ≥ 55°C, which indicates that it is a cold-adapted enzyme. CN1E1 has a distinct substrate preference compared with other α/β-hydrolases because it is catalytically most active for hydrolysing polyaromatic hydrocarbon (phenanthrene, anthracene, naphthalene, benzoyl, protocatechuate and phthalate) esters (7200–21 000 units g−1 protein at 40°C and pH 8.0). The enzyme also accepts 44 structurally different common esters with different levels of enantio-selectivity (1.0–55 000 units g−1 protein), including (±)-menthyl-acetate, (±)-neomenthyl acetate, (±)-pantolactone, (±)-methyl-mandelate, (±)-methyl-lactate and (±)-glycidyl 4-nitrobenzoate (in that order). The results provide the first biochemical evidence suggesting that such broad-spectrum esterases may be an ecological advantage for bacteria that mineralize recalcitrant pollutants (including oil refinery products, plasticizers and pesticides) as carbon sources under pollution pressure. They also offer a new tool for the stereo-assembly (i.e. through ester bonds) of multi-aromatic molecules with benzene rings that are useful for biology, chemistry and materials sciences for cases in which enzyme methods are not yet available. PMID:24418210

Distribution of polycyclic aromatic hydrocarbons in riverine waters after Mediterranean forest fires.

PubMed

Olivella, M A; Ribalta, T G; de Febrer, A R; Mollet, J M; de Las Heras, F X C

2006-02-15

Extensive forest fires occurred in Catalonia, northern Spain, in 1994. In our study, concentrations and profiles of 12 parent polycyclic aromatic hydrocarbons (PAHs) were determined in riverine waters, ash and sediment samples at nine sampling sites (W1-W9) and at three sampling dates from Llobregat hydrographic basin: in August, 1994, one month after the extensive forest fires; in September, 1994, after the first heavy autumn rainfalls and in January, 1995, six months after forest fires. In August 1994, the total concentrations of 12 PAHs measured in riverine waters varied from 2 ng/l to 336 ng/l. In September 1994, the total PAH concentrations decreased to 0.2-31 ng/l and in January 1995, from 9 ng/l to 73 ng/l. In August, the composition pattern of PAHs showed a distribution dominated by 4-ring PAHs (pyrene, chrysene+triphenylene, benzo(a)anthracene) at W3-W6, W8 and W9 and 3-ring PAHs (phenanthrene) at W1, W2 and W7. In September, a preference by 3-ring PAHs (phenanthrene) at all sampling sites except W5 was shown and in January was clearly dominated by 4-ring PAHs (chrysene+triphenylene, pyrene, benzo(a)anthracene) at all sampling sites. In ash and sediment samples, the total concentrations of 12 PAHs ranged from 1.3 ng/g to 19 ng/g. The dominant compound was phenanthrene.

Exchangeable cations-mediated photodegradation of polycyclic aromatic hydrocarbons (PAHs) on smectite surface under visible light.

PubMed

Jia, Hanzhong; Li, Li; Chen, Hongxia; Zhao, Yue; Li, Xiyou; Wang, Chuanyi

2015-04-28

Clay minerals saturated with different exchangeable cations are expected to play various roles in photodegradation of polycyclic aromatic hydrocarbons (PAHs) via direct and/or indirect pathways on clay surfaces. In the present study, anthracene and phenanthrene were selected as molecule probes to investigate the roles of exchangeable cations on their photodegradation under visible light irradiation. For five types of cation-modified smectite clays, the photodegradation rate of anthracene and phenanthrene follows the order: Fe(3+)>Al(3+)>Cu(2+)>Ca(2+)>K(+)>Na(+), which is consistent with the binding energy of cation-π interactions between PAHs and exchangeable cations. The result suggests that PAHs photolysis rate depends on cation-π interactions on clay surfaces. Meanwhile, the deposition of anthracene at the Na(+)-smectite and K(+)-smectite surface favors solar light absorption, resulting in enhanced direct photodecomposition of PAHs. On the other hand, smectite clays saturated with Fe(3+), Al(3+), and Cu(2+) are highly photoreactive and can act as potential catalysts giving rise to oxidative radicals such as O2(-) , which initiate the transformation of PAHs. The present work provides valuable insights into understanding the transformation and fate of PAHs in the natural soil environment and sheds light on the development of technologies for contaminated land remediation. Copyright © 2015 Elsevier B.V. All rights reserved.

SURFACTANT ENHANCED PHOTO-OXIDATION OF WASTEWATERS

EPA Science Inventory

Initial research projects using the nonionic surfactant Brij-35 established that this surfactant could successfully adsolublize aromatic organic pollutants such as anthracene, naphthalene, benzoic acid, chlorophenol, and benzene onto the surface of TiO₂ par...

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.

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.

The influence of smoking in traditional conditions on content of polycyclic aromatic hydrocarbons in Petrovská klobása

NASA Astrophysics Data System (ADS)

Škaljac, S.; Petrović, Lj; Jokanović, M.; Tomović, V.; Tasić, T.; Ivić, M.; Šojić, B.; Ikonić, P.; Džinić, N.

2017-09-01

The aim of this study was to determine the content of 13 polycyclic aromatic hydrocarbons (acenaphthylene, fluorene, phenanthrene, anthracene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene) the from Environmental Protection Agency list (US-EPA PAH) in traditional dry fermented sausage Petrovská klobása. Sausages were smoked in traditional conditions and samples for analyses were taken on day 0 of production (0), at the end of drying (T1) and at the end of the storage period (T2). The highest total content of 13 US-EPA PAHs was determined in sausages at the end of the storage period (73.5 μg/kg). Phenanthrene was the most abundant of the PAHs in all examined sausage samples (0-4.90 μg/kg T1-18.0 μg/kg and T2-26.3 μg/kg). Benzo[a]pyrene, with a maximum allowed content in smoked meat products of 2 µg/kg (EC No. 835/2011), was below the limit of detection in all examined samples. Also, PAH4 (the total content of benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) with a maximum allowed content in smoked meat products of 12 µg/kg (EC No. 835/2011), was below the limit of detection in all examined sausage samples. According to the results obtained in this study, and in regard to the European regulation on PAHs content, the dry fermented sausage Petrovská klobása, smoked in traditional conditions, was safe for consumers.

High-Sensitivity Surface-Enhanced Raman Scattering (SERS) Substrate Based on a Gold Colloid Solution with a pH Change for Detection of Trace-Level Polycyclic Aromatic Hydrocarbons in Aqueous Solution.

PubMed

Shi, Xiaofeng; Liu, Shu; Han, Xiaohong; Ma, Jun; Jiang, Yongchao; Yu, Guifeng

2015-05-01

In this study, a gold colloid solution whose parameters were optimized, and without any surfactants, was developed as a surface-enhanced Raman scattering (SERS) substrate for the detection of trace-level polycyclic aromatic hydrocarbons (PAHs). A gold colloid solution with 57 nm gold particles and pH 13 was prepared to be the SERS substrate. It had impressive enhancement that was two orders of magnitude higher than that of a gold colloid solution with 57 nm gold particles and without pH change (pH 6). Even with a compact field-based Raman spectrometer, naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene were detected, with limits of detection at 6.8 nM, 3.4 nM, 1.8 nM, 0.68 nM (680 pM), and 0.44 nM (440 pM), respectively. The significant enhancement was ascribed to an electromagnetic mechanism and a charge-transfer mechanism. Quantitative analyses for these five PAHs in water were also performed. The SERS intensities of PAHs were found to have good linear dependence relations with the concentrations in low concentration. This high-sensitivity, easily prepared substrate offers a promising technology for the quantitative detection of trace-level PAHs.

Gas chromatographic retention behavior of polycyclic aromatic hydrocarbons (PAHs) and alkyl-substituted PAHs on two stationary phases of different selectivity.

PubMed

Nalin, Federica; Sander, Lane C; Wilson, Walter B; Wise, Stephen A

2018-01-01

Retention indices (I) for 45 polycyclic aromatic hydrocarbons (PAHs) and 63 methyl-substituted PAHs were determined by gas chromatography - mass spectrometry (GC-MS) using two different stationary phases: a Rxi-PAH phase (a "higher phenyl-content stationary phase") and a 50% (mole fraction) liquid crystalline dimethylpolysiloxane phase. Retention data were obtained for parent PAHs from molecular mass (MM) 128 g/mol (naphthalene) to 328 g/mol (benzo[c]picene) and for 12 sets of methyl-PAHs (methylfluorenes, methylanthracenes, methylphenanthrenes, methylfluoranthenes, methylpyrenes, methylbenz[a]anthracenes, methylbenzo[c]phenanthrenes, methylchrysenes, methyltriphenylenes, methylbenzo[a]pyrenes, methylperylenes, and methylpicenes). Molecular shape descriptors such as length-to-breath ratio (L/B) and thickness (T) were determined for all the PAHs studied. Correlation between I and L/B ratio was evaluated for both stationary phases with a better correlation observed for the 50% liquid crystalline phase (correlation coefficients ranging from 0.22 to 1.00). Graphical Abstract GC separation of six methylchrysene isomers (m/z 242) on two different stationary phases: 50 % phenyl-like methylpolysiloxane phase and 50 % liquid crystalline phase. Retention indices (I) are plotted as a function of L/B for both phases. The data marker numbers identify each isomer based on methyl-substitution position.

COSOLVENT EFFECTS ON SORPTION AND MOBILITY OF ORGANIC CONTAMINANTS IN SOILS

EPA Science Inventory

Batch equilibrium and column miscible displacement techniques were used to investigate the influence of an organic cosolvent (methanol) on the sorption and transport of three hydrophobic organic chemicals (HOCs) — naphthalene, phenanthrene, and diuron herbicide — in a sandy surfa...

Multisubstrate biodegradation kinetics of naphthalene, phenanthrene, and pyrene mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guha, S.; Peters, C.A.; Jaffe, P.R.

Biodegradation kinetics of naphthalene, phenanthrene and pyrene were studied in sole-substrate systems, and in binary and ternary mixtures to examine substrate interactions. The experiments were conducted in aerobic batch aqueous systems inoculated with a mixed culture that had been isolated from soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Monod kinetic parameters and yield coefficients for the individual parameters and yield coefficients for the individual compounds were estimated from substrate depletion and CO{sub 2} evolution rate data in sole-substrate experiments. In all three binary mixture experiments, biodegradation kinetics were comparable to the sole-substrate kinetics. In the ternary mixture, biodegradation of naphthalenemore » was inhibited and the biodegradation rates of phenanthrene and pyrene were enhanced. A multisubstrate form of the Monod kinetic model was found to adequately predict substrate interactions in the binary and ternary mixtures using only the parameters derived from sole-substrate experiments. Numerical simulations of biomass growth kinetics explain the observed range of behaviors in PAH mixtures. In general, the biodegradation rates of the more degradable and abundant compounds are reduced due to competitive inhibition, but enhanced biodegradation of the more recalcitrant PAHs occurs due to simultaneous biomass growth on multiple substrates. In PAH-contaminated environments, substrate interactions may be very large due to additive effects from the large number of compounds present.« less

ORGANIC COSOLVENT EFFECTS ON THE SORPTION AND TRANSPORT OF NEUTRAL ORGANIC CHEMICALS

EPA Science Inventory

Soil column miscible displacement techniques were used to investigate the effects of an organic cosolvent (methanol) on the sorption and transport of three neutral organic chemicals; naphthalene, phenanthrene, and the herbicide diuron, through a sandy surface soil. A two-domain, ...

Identification of products formed during the heterogeneous nitration and ozonation of polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Cochran, Richard E.; Jeong, Haewoo; Haddadi, Shokouh; Fisseha Derseh, Rebeka; Gowan, Alexandra; Beránek, Josef; Kubátová, Alena

2016-03-01

The 3- and 4-ring polycyclic aromatic hydrocarbons (PAHs) are the most abundant of PAHs in air particulate matter (PM). Thus we have investigated heterogeneous oxidation of 3- and 4-ring PAHs in a small-scale flow reactor using quartz filter as a support. Four representative PAHs, anthracene, phenanthrene, pyrene, and fluoranthene, were exposed to either NO2, O3 or NO2+O3 (NO3/N2O5) with a goal to identify and attempt quantification of major product distribution. A combination of gas chromatography with mass spectrometry (GC-MS) with/without derivatization and liquid chromatography with high resolution MS (LC-HRMS) was used for identification. For the first time, a comprehensive characterization of a broad range of products enabled identifying ketone/diketone, aldehyde, hydroxyl, and carboxylic acid PAH derivatives. Exposure to NO3/N2O5 (formed by reacting NO2 with O3, a more powerful reactant than either O3 or NO2) produced additional compounds not observed with either oxidant alone. Multiple isomers of nitrofluoranthene and, for the first time, nitrophenanthrene were identified. In addition hydroxy-nitro-PAH derivatives were observed for the reaction of anthracene with NO3/N2O5. Monitoring of specific common ions such as those of 176 and 205 m/z attributed to carbonyl phenanthrene and deprotonated phenanthrene ions respectively was shown to be a useful tool for identification of multiple pyrene oxidation products.

GROUNDWATER TRANSPORT OF HYDROPHOBIC ORGANIC COMPOUNDS IN THE PRESENCE OF DISSOLVED ORGANIC MATTER

EPA Science Inventory

The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. Three compounds (naphthalene, phenanthrene and DDT) that spanned three orders of magnitude in water solubility were used. Instead of humic matter, mo...

Impact of kerogen heterogeneity on sorption of organic pollutants. 2. Sorption equilibria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, C.; Yu, Z.Q.; Xiao, B.H.

2009-08-15

Phenanthrene and naphthalene sorption isotherms were measured for three different series of kerogen materials using completely mixed batch reactors. Sorption isotherms were nonlinear for each sorbate-sorbent system, and the Freundlich isotherm equation fit the sorption data well. The Freundlich isotherm linearity parameter n ranged from 0.192 to 0.729 for phenanthrene and from 0.389 to 0.731 for naphthalene. The n values correlated linearly with rigidity and aromaticity of the kerogen matrix, but the single-point, organic carbon-normalized distribution coefficients varied dramatically among the tested sorbents. A dual-mode sorption equation consisting of a linear partitioning domain and a Langmuir adsorption domain adequately quantifiedmore » the overall sorption equilibrium for each sorbent-sorbate system. Both models fit the data well, with r{sup 2} values of 0.965 to 0.996 for the Freundlich model and 0.963 to 0.997 for the dual-mode model for the phenanthrene sorption isotherms. The dual-mode model fitting results showed that as the rigidity and aromaticity of the kerogen matrix increased, the contribution of the linear partitioning domain to the overall sorption equilibrium decreased, whereas the contribution of the Langmuir adsorption domain increased. The present study suggested that kerogen materials found in soils and sediments should not be treated as a single, unified, carbonaceous sorbent phase.« less

40 CFR 464.31 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (dichloromethane) 55. naphthalene 64. pentachlorophenol 65. phenol 66. bis(2-ethylhexyl)phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72. benzo (a)anthracene (1,2... (dichloromethane) 66. bis (2-ethylhexyl) phthalate 77. acenaphthylene 84. pyrene (4) Melting Furnace Scrubber...

40 CFR 464.31 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (dichloromethane) 55. naphthalene 64. pentachlorophenol 65. phenol 66. bis(2-ethylhexyl)phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72. benzo (a)anthracene (1,2... (dichloromethane) 66. bis (2-ethylhexyl) phthalate 77. acenaphthylene 84. pyrene (4) Melting Furnace Scrubber...

Degradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture and its component pure cultures, obtained from PAH-contaminated soil.

PubMed

Trzesicka-Mlynarz, D; Ward, O P

1995-06-01

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.

Enhanced polyaromatic hydrocarbon degradation by adapted cultures of actinomycete strains.

PubMed

Bourguignon, Natalia; Isaac, Paula; Alvarez, Héctor; Amoroso, María J; Ferrero, Marcela A

2014-12-01

Fifteen actinomycete strains were evaluated for their potential use in removal of polycyclic aromatic hydrocarbons (PAH). Their capability to degrade of naphthalene, phenanthrene, and pyrene was tested in minimal medium (MM) and MM with glucose as another substrate. Degradation of naphthalene in MM was observed in all isolates at different rates, reaching maximum values near to 76% in some strains of Streptomyces, Rhodococcus sp. 016 and Amycolatopsis tucumanensis DSM 45259. Maximum values of degradation of phenanthrene in MM occurred in cultures of A. tucumanensis DSM 45259 (36.2%) and Streptomyces sp. A12 (20%), while the degradation of pyrene in MM was poor and only significant with Streptomyces sp. A12 (4.3%). Because of the poor performance when growing on phenanthrene and pyrene alone, Rhodococcus sp. 20, Rhodococcus sp. 016, A. tucumanensis DSM 45259, Streptomyces sp. A2, and Streptomyces sp. A12 were challenged to an adaptation schedule of successive cultures on a fresh solid medium supplemented with PAHs, decreasing concentration of glucose in each step. As a result, an enhanced degradation of PAHs by adapted strains was observed in the presence of glucose as co-substrate, without degradation of phenanthrene and pyrene in MM while an increase to up to 50% of degradation was seen with these strains in glucose amended media. An internal fragment of the catA gene, which codes for catechol 1,2-dioxygenase, was amplified from both Rhodococcus strains, showing the potential for degradation of aromatic compounds via salycilate. These results allow us to propose the usefulness of these actinomycete strains for PAH bioremediation in the environment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure-property relationships: asymmetric alkylphenyl-substituted anthracene molecules for use in small-molecule solar cells.

PubMed

Kim, Yu Jin; Ahn, Eun Soo; Jang, Sang Hun; An, Tae Kyu; Kwon, Soon-Ki; Chung, Dae Sung; Kim, Yun-Hi; Park, Chan Eon

2015-05-11

Two asymmetric anthracene-based organic molecules, NDHPEA and TNDHPEA, were prepared without or with a thiophene spacer between the anthracene and naphthalene units. These asymmetric oligomers displayed different degrees of coplanarity, as evidenced by differences in the dihedral angles calculated by using DFT. Differential scanning calorimetry and XRD studies were used to probe the crystallization characteristics and molecular packing structures in the active layers. The coplanarity of the molecules in the asymmetric structure significantly affected the crystallization behavior and the formation of crystalline domains in the solid state. The small-molecule crystalline properties were correlated with the device physics by determining the J-V characteristics and hole mobilities of the devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of the presence of PAHs and coal tar on naphthalene sorption in soils

NASA Astrophysics Data System (ADS)

Bayard, Rémy; Barna, Ligia; Mahjoub, Borhane; Gourdon, Rémy

2000-11-01

The mobility of the most water-soluble polynuclear aromatic hydrocarbons (PAHs) such as naphthalene in contaminated soils from manufactured gas plant (MGP) sites or other similar sites is influenced not only by the naturally occurring soil organic matter (SOM) but also, and in many cases mostly, by the nature and concentration of coal tar xenobiotic organic matter (XOM) and other PAH molecules present in the medium under various physical states. The objective of the present study was to quantify the effects of these factors using batch experiments, in order to simulate naphthalene transport in soil-tar-water systems using column experiments. Naphthalene sorption was studied in the presence of (i) solid coal tar particles, (ii) phenanthrene supplied as pure crystals, in the aqueous solution or already sorbed onto the soil, (iii) fluoranthene as pure crystals, and (iv) an aqueous solution of organic molecules extracted from a liquid tar. All experiments were conducted under abiotic conditions using short naphthalene/sorbent contact times of 24-60 h. Although these tests do not reflect true equilibrium conditions which usually take more time to establish, they were used to segregate relatively rapid sorption phenomena ("pseudo equilibrium") from slow sorption and other aging phenomena. For longer contact times, published data have shown that experimental biases due to progressive changes in the characteristics of the soil and the solution may drastically modify the affinity of the solutes for the soil. Slow diffusion in the microporosity and in dense organic phases may also become significant over the long term, along with some irreversible aging phenomena which have not been addressed in this work. Results showed that PAHs had no effect on naphthalene sorption when present in the aqueous solution or as pure crystals, due to their low solubility in water. Adsorbed phenanthrene was found to reduce naphthalene adsorption only when present at relatively high concentrations (about 120 mg/kg) in the soil. In contrast, experiments carried out with coal tar particles revealed a significant effect. Naphthalene sorption appeared to be proportional to the amount of coal tar added to the sand or soil, and a much higher affinity of naphthalene for XOM ( Koc above 2000 cm 3/g) than SOM ( Koc around 300 cm 3/g) was observed. Naphthalene transport in the columns of sand or soil spiked with coal tar particles was simulated very satisfactorily with a dual double-domain model. Around 90% of naphthalene retention by coal tar was found to occur within the organic phase, suggesting a phase partition process which may be explained by the amorphous nature of the XOM and its extreme affinity for naphthalene. For SOM, however, which is present as porous microaggregates of clay and humic substances, with less affinity for naphthalene, only 1/3 of naphthalene retention was found to occur within the organic phase, underlining the significant role of surface adsorption in the short term behavior of naphthalene in soil. For longer contact times, the model simulations proposed in the present study should be coupled to slow sorption, aging and biodegradation models to describe long-term behavior of naphthalene in soil-tar-water systems.

Linear acene derivatives - New routes to pentacene and naphthacene and the first synthesis of a triptycene with two anthracene moieties

NASA Technical Reports Server (NTRS)

Luo, Jihmei; Hart, Harold

1987-01-01

The cycloaddition of o-xylylene to arene 1,4-endoxides was used to construct linear arene derivatives. An analogous sequence but with naphthalene 1,4-endoxides gave naphthacenes. Dehydration of the di adducts from 4 and anthracene 1,4:5,8-diendoxides gave a mixture of 5,9,14,18- and 5,8,15,18-tetrahydroheptacenes 3 and 9. The previously unknown triptycene 2 was synthesized from 5,14-dihydropentacene, an intermediate in the new pentacene synthesis, in three steps and 29 percent overall yield.

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.

Appraisement, source apportionment and health risk of polycyclic aromatic hydrocarbons (PAHs) in vehicle-wash wastewater, Pakistan.

PubMed

Qamar, Zahir; Khan, Sardar; Khan, Anwarzeb; Aamir, Muhammad; Nawab, Javed; Waqas, Muhammad

2017-12-15

Vehicle-wash wastewater (VWW) contains elevated concentrations of different petrochemicals including polycyclic aromatic hydrocarbons (PAHs), a carcinogenic group of organic compounds. This study investigates the discharge of PAHs present in the untreated wastewater of vehicle-wash stations (VWS) located in district Peshawar, Pakistan. The data obtained was being novel with the detection of 16 USEPA PAHs (both individuals and total) and compared with earlier studies and international standards. The ∑16PAHs in wastewater from light vehicle-wash stations (LVWS) and heavy vehicle-wash stations (HVWS) ranged from 245-429μg/l and 957-1582μg/l, respectively. A significant difference (p<0.01) was observed in PAHs discharged from LVWS and HVWS. The projected ∑16PAHs discharge from both HVWS (92% of total generated PAHs) and LVWS (8%) was about 5109.9 g per annum. According to PAH diagnostic ratios, PAHs were both petrogenic (chrysene/benz(a)anthracene, low molecular weight/high molecular weight) and pyrogenic (phenanthrene/anthracene, fluoranthene/pyrene, fluoranthene/fluoranthene+pyrene) in origin. The highest toxic equivalent quotient (TEQ) value was shown by benzo(a)pyrene (21.6μg/l) followed by dibenz(ah)anthracene (9.81μg/l) in wastewater from HVWS. However, in LVWS the case was reversed with highest value (7.54μg/l) for dibenz(ah)anthracene followed by benzo(a)pyrene (3.54μg/l). The lowest TEQ value was indicated for phenanthrene (0.007μg/l) in wastewater of LVWS, while pyrene showed the lowest value (0.007μg/l) in wastewater of HVWS. The results indicated that VWS contribute significant amount of PAHs each year, which is of great concern regarding water quality, ecological and human health risk. This is the first systematic and comprehensive research related with generation of PAHs load per day, week, month and annum from VWS, their source apportionment and health effects in Pakistan. Copyright © 2017 Elsevier B.V. All rights reserved.

PAH concentrations simulated with the AURAMS-PAH chemical transport model over Canada and the USA

NASA Astrophysics Data System (ADS)

Galarneau, E.; Makar, P. A.; Zheng, Q.; Narayan, J.; Zhang, J.; Moran, M. D.; Bari, M. A.; Pathela, S.; Chen, A.; Chlumsky, R.

2014-04-01

The offline Eulerian AURAMS (A Unified Regional Air quality Modelling System) chemical transport model was adapted to simulate airborne concentrations of seven PAHs (polycyclic aromatic hydrocarbons): phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene + triphenylene, and benzo[a]pyrene. The model was then run for the year 2002 with hourly output on a grid covering southern Canada and the continental USA with 42 km horizontal grid spacing. Model predictions were compared to ~5000 24 h-average PAH measurements from 45 sites, most of which were located in urban or industrial areas. Eight of the measurement sites also provided data on particle/gas partitioning which had been modelled using two alternative schemes. This is the first known regional modelling study for PAHs over a North American domain and the first modelling study at any scale to compare alternative particle/gas partitioning schemes against paired field measurements. The goal of the study was to provide output concentration maps of use to assessing human inhalation exposure to PAHs in ambient air. Annual average modelled total (gas + particle) concentrations were statistically indistinguishable from measured values for fluoranthene, pyrene and benz[a]anthracene whereas the model underestimated concentrations of phenanthrene, anthracene and chrysene + triphenylene. Significance for benzo[a]pyrene performance was close to the statistical threshold and depended on the particle/gas partitioning scheme employed. On a day-to-day basis, the model simulated total PAH concentrations to the correct order of magnitude the majority of the time. The model showed seasonal differences in prediction quality for volatile species which suggests that a missing emission source such as air-surface exchange should be included in future versions. Model performance differed substantially between measurement locations and the limited available evidence suggests that the model's spatial resolution was too coarse to capture the distribution of concentrations in densely populated areas. A more detailed analysis of the factors influencing modelled particle/gas partitioning is warranted based on the findings in this study.

Naphthalene degradation by bacterial consortium (DV-AL) developed from Alang-Sosiya ship breaking yard, Gujarat, India.

PubMed

Patel, Vilas; Jain, Siddharth; Madamwar, Datta

2012-03-01

Naphthalene degrading bacterial consortium (DV-AL) was developed by enrichment culture technique from sediment collected from the Alang-Sosiya ship breaking yard, Gujarat, India. The 16S rRNA gene based molecular analyzes revealed that the bacterial consortium (DV-AL) consisted of four strains namely, Achromobacter sp. BAB239, Pseudomonas sp. DV-AL2, Enterobacter sp. BAB240 and Pseudomonas sp. BAB241. Consortium DV-AL was able to degrade 1000 ppm of naphthalene in Bushnell Haas medium (BHM) containing peptone (0.1%) as co-substrate with an initial pH of 8.0 at 37°C under shaking conditions (150 rpm) within 24h. Maximum growth rate and naphthalene degradation rate were found to be 0.0389 h(-1) and 80 mg h(-1), respectively. Consortium DV-AL was able to utilize other aromatic and aliphatic hydrocarbons such as benzene, phenol, carbazole, petroleum oil, diesel fuel, and phenanthrene and 2-methyl naphthalene as sole carbon source. Consortium DV-AL was also efficient to degrade naphthalene in the presence of other pollutants such as petroleum hydrocarbons and heavy metals. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Homology modeling, simulation and molecular docking studies of catechol-2, 3-Dioxygenase from Burkholderia cepacia: Involved in degradation of Petroleum hydrocarbons.

PubMed

Ajao, At; Kannan, M; Yakubu, Se; Vj, Umoh; Jb, Ameh

2012-01-01

Catechol 2, 3-dioxygenase is present in several types of bacteria and undergoes degradation of environmental pollutants through an important key biochemical pathways. Specifically, this enzyme cleaves aromatic rings of several environmental pollutants such as toluene, xylene, naphthalene and biphenyl derivatives. Hence, the importance of Catechol 2, 3-dioxygenase and its role in the degradation of environmental pollutants made us to predict the three-dimensional structure of Catechol 2, 3-dioxygenase from Burkholderia cepacia. The 10ns molecular dynamics simulation was carried out to check the stability of the modeled Catechol 2, 3- dioxygenase. The results show that the model was energetically stable, and it attains their equilibrium within 2000 ps of production MD run. The docking of various petroleum hydrocarbons into the Catechol 2,3-dioxygenase reveals that the benzene, O-xylene, Toluene, Fluorene, Naphthalene, Carbazol, Pyrene, Dibenzothiophene, Anthracene, Phenanthrene, Biphenyl makes strong hydrogen bond and Van der waals interaction with the active site residues of H150, L152, W198, H206, H220, H252, I254, T255, Y261, E271, L276 and F309. Free energy of binding and estimated inhibition constant of these compounds demonstrates that they are energetically stable in their binding cavity. Chrysene shows positive energy of binding in the active site atom of Fe. Except Pyrene all the substrates made close contact with Fe atom by the distance ranges from 1.67 to 2.43 Å. In addition to that, the above mentioned substrate except pyrene all other made π-π stacking interaction with H252 by the distance ranges from 3.40 to 3.90 Å. All these docking results reveal that, except Chrysene all other substrate has good free energy of binding to hold enough in the active site and makes strong VdW interaction with Catechol-2,3-dioxygenase. These results suggest that, the enzyme is capable of catalyzing the above-mentioned substrate.

Homology modeling, simulation and molecular docking studies of catechol-2, 3-Dioxygenase from Burkholderia cepacia: Involved in degradation of Petroleum hydrocarbons

PubMed Central

Ajao, AT; Kannan, M; Yakubu, SE; VJ, Umoh; JB, Ameh

2012-01-01

Catechol 2, 3-dioxygenase is present in several types of bacteria and undergoes degradation of environmental pollutants through an important key biochemical pathways. Specifically, this enzyme cleaves aromatic rings of several environmental pollutants such as toluene, xylene, naphthalene and biphenyl derivatives. Hence, the importance of Catechol 2, 3-dioxygenase and its role in the degradation of environmental pollutants made us to predict the three-dimensional structure of Catechol 2, 3-dioxygenase from Burkholderia cepacia. The 10ns molecular dynamics simulation was carried out to check the stability of the modeled Catechol 2, 3- dioxygenase. The results show that the model was energetically stable, and it attains their equilibrium within 2000 ps of production MD run. The docking of various petroleum hydrocarbons into the Catechol 2,3-dioxygenase reveals that the benzene, O-xylene, Toluene, Fluorene, Naphthalene, Carbazol, Pyrene, Dibenzothiophene, Anthracene, Phenanthrene, Biphenyl makes strong hydrogen bond and Van der waals interaction with the active site residues of H150, L152, W198, H206, H220, H252, I254, T255, Y261, E271, L276 and F309. Free energy of binding and estimated inhibition constant of these compounds demonstrates that they are energetically stable in their binding cavity. Chrysene shows positive energy of binding in the active site atom of Fe. Except Pyrene all the substrates made close contact with Fe atom by the distance ranges from 1.67 to 2.43 Å. In addition to that, the above mentioned substrate except pyrene all other made π-π stacking interaction with H252 by the distance ranges from 3.40 to 3.90 Å. All these docking results reveal that, except Chrysene all other substrate has good free energy of binding to hold enough in the active site and makes strong VdW interaction with Catechol-2,3-dioxygenase. These results suggest that, the enzyme is capable of catalyzing the above-mentioned substrate. PMID:23144539

PAHs in corn grains submitted to drying with firewood.

PubMed

de Lima, Rafael Friedrich; Dionello, Rafael Gomes; Peralba, Maria do Carmo Ruaro; Barrionuevo, Simone; Radunz, Lauri Lourenço; Reichert Júnior, Francisco Wilson

2017-01-15

Grain drying using firewood as fuel for air heating, with direct fire, is still widely used in Brazil. The combustion of organic material, such as wood, can generate polycyclic aromatic hydrocarbons (PAHs) which are known to have carcinogenic potential. In the present work corn grain drying was carried out at three drying air temperatures: 60°C, 60/80°C and 80°C. Following the drying process, the presence and quantification of PAH in the corn grains was investigated. After extracting the PAHs of the matrix, the material was subjected to analysis by gas chromatography with mass detector. he results showed the presence of seven compounds: fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene and chrysene. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using a Differential Scanning Calorimeter to Teach Phase Equilibria to Students of Igneous and Metamorphic Petrology

ERIC Educational Resources Information Center

Maria, Anton H.; Millam, Evan L.; Wright, Carrie L.

2011-01-01

As an aid for teaching phase equilibria to undergraduate students of igneous and metamorphic petrology, we have designed a laboratory exercise that allows them to create a phase diagram from data produced by differential scanning calorimetry. By preparing and analyzing samples of naphthalene and phenanthrene, students acquire hands-on insight into…

The anharmonic quartic force field infrared spectra of three polycyclic aromatic hydrocarbons: Naphthalene, anthracene, and tetracene.

PubMed

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

2015-12-14

Current efforts to characterize and study interstellar polycyclic aromatic hydrocarbons (PAHs) rely heavily on theoretically predicted infrared (IR) spectra. Generally, such studies use the scaled harmonic frequencies for band positions and double harmonic approximation for intensities of species, and then compare these calculated spectra with experimental spectra obtained under matrix isolation conditions. High-resolution gas-phase experimental spectroscopic studies have recently revealed that the double harmonic approximation is not sufficient for reliable spectra prediction. In this paper, we present the anharmonic theoretical spectra of three PAHs: naphthalene, anthracene, and tetracene, computed with a locally modified version of the SPECTRO program using Cartesian derivatives transformed from Gaussian 09 normal coordinate force constants. Proper treatments of Fermi resonances lead to an impressive improvement on the agreement between the observed and theoretical spectra, especially in the C-H stretching region. All major IR absorption features in the full-scale matrix-isolated spectra, the high-temperature gas-phase spectra, and the most recent high-resolution gas-phase spectra obtained under supersonically cooled molecular beam conditions in the CH-stretching region are assigned.

The anharmonic quartic force field infrared spectra of three polycyclic aromatic hydrocarbons: Naphthalene, anthracene, and tetracene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackie, Cameron J., E-mail: mackie@strw.leidenuniv.nl; Candian, Alessandra; Tielens, Alexander G. G. M.

2015-12-14

Current efforts to characterize and study interstellar polycyclic aromatic hydrocarbons (PAHs) rely heavily on theoretically predicted infrared (IR) spectra. Generally, such studies use the scaled harmonic frequencies for band positions and double harmonic approximation for intensities of species, and then compare these calculated spectra with experimental spectra obtained under matrix isolation conditions. High-resolution gas-phase experimental spectroscopic studies have recently revealed that the double harmonic approximation is not sufficient for reliable spectra prediction. In this paper, we present the anharmonic theoretical spectra of three PAHs: naphthalene, anthracene, and tetracene, computed with a locally modified version of the SPECTRO program using Cartesianmore » derivatives transformed from Gaussian 09 normal coordinate force constants. Proper treatments of Fermi resonances lead to an impressive improvement on the agreement between the observed and theoretical spectra, especially in the C–H stretching region. All major IR absorption features in the full-scale matrix-isolated spectra, the high-temperature gas-phase spectra, and the most recent high-resolution gas-phase spectra obtained under supersonically cooled molecular beam conditions in the CH-stretching region are assigned.« less

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge.

PubMed

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946-4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments.

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge

PubMed Central

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946–4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments. PMID:26379634

Characterization and distribution of polycyclic aromatic hydrocarbon contaminations in surface sediment and water from Gao-ping River, Taiwan.

PubMed

Doong, Ruey-An; Lin, Yu-Tin

2004-04-01

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected from 12 locations in Gao-ping River, Taiwan were analyzed. Molecular ratios and principal component analysis (PCA) were used to characterize the possible pollution sources. Concentrations of total 16 PAHs (SigmaPAHs) in water samples ranged from below method detection limits (

Common y-intercept and single compound regressions of gas-particle partitioning data vs 1/T

NASA Astrophysics Data System (ADS)

Pankow, James F.

Confidence intervals are placed around the log Kp vs 1/ T correlation equations obtained using simple linear regressions (SLR) with the gas-particle partitioning data set of Yamasaki et al. [(1982) Env. Sci. Technol.16, 189-194]. The compounds and groups of compounds studied include the polycylic aromatic hydrocarbons phenanthrene + anthracene, me-phenanthrene + me-anthracene, fluoranthene, pyrene, benzo[ a]fluorene + benzo[ b]fluorene, chrysene + benz[ a]anthracene + triphenylene, benzo[ b]fluoranthene + benzo[ k]fluoranthene, and benzo[ a]pyrene + benzo[ e]pyrene (note: me = methyl). For any given compound, at equilibrium, the partition coefficient Kp equals ( F/ TSP)/ A where F is the particulate-matter associated concentration (ng m -3), A is the gas-phase concentration (ng m -3), and TSP is the concentration of particulate matter (μg m -3). At temperatures more than 10°C from the mean sampling temperature of 17°C, the confidence intervals are quite wide. Since theory predicts that similar compounds sorbing on the same particulate matter should possess very similar y-intercepts, the data set was also fitted using a special common y-intercept regression (CYIR). For most of the compounds, the CYIR equations fell inside of the SLR 95% confidence intervals. The CYIR y-intercept value is -18.48, and is reasonably close to the type of value that can be predicted for PAH compounds. The set of CYIR regression equations is probably more reliable than the set of SLR equations. For example, the CYIR-derived desorption enthalpies are much more highly correlated with vaporization enthalpies than are the SLR-derived desorption enthalpies. It is recommended that the CYIR approach be considered whenever analysing temperature-dependent gas-particle partitioning data.

Remarkably constant PAH concentrations in Swiss soils over the last 30 years.

PubMed

Gubler, Andreas; Wächter, Daniel; Blum, Franziska; Bucheli, Thomas D

2015-10-01

Although polycyclic aromatic hydrocarbons (PAH) are of concern due to their carcinogenic, mutagenic, and teratogenic properties and their ubiquitous occurrence in environmental compartments, only few studies assessed the temporal evolutions of PAH contents of soils over extended time periods. The Swiss Soil Monitoring Network NABO runs long-term monitoring sites resampled every five years since the 1980s. In the present study, soil (0-20 cm) samples collected from 1985 through 2013 at 25 selected monitoring sites were analysed for the 16 priority PAH according to the U.S. EPA and five PAH marker substances. We observed divergent trends for light PAH, such as naphthalene and phenanthrene, compared with heavy PAH, such as benzo[a]pyrene and benzo[ghi]perylene. Whereas the former showed decreasing concentrations since the late 1980s, no significant trends were found for the latter. Furthermore, the analyses showed that naphthalene contents decreased most strongly at rural sites featuring low population densities, while phenanthrene contents generally decreased most strongly at semi-rural sites. The deviating evolutions of light and heavy PAH were mainly attributed to their differing physico-chemical properties. Temporal evolutions in soils contradict emission inventory data suggesting PAH emissions to decline since the 1980s.

Characterization of a Microbial Consortium for the Bioremoval of Polycyclic Aromatic Hydrocarbons (PAHs) in Water

PubMed Central

Blanco-Enríquez, Esmeralda G.; Zavala-Díaz de la Serna, Francisco Javier; Peralta-Pérez, María del Rosario; Ballinas-Casarrubias, Lourdes; Salmerón, Iván; Rubio-Arias, Héctor; Rocha-Gutiérrez, Beatriz A.

2018-01-01

Pollution of freshwater ecosystems from polycyclic aromatic hydrocarbons (PAHs) is a global concern. The US Environmental Protection Agency (EPA) has included the PAHs pyrene, phenanthrene, and naphthalene among the 16 priority compounds of special concern for their toxicological effects. The aim of this study was to adapt and characterize a microbial consortium from ore waste with the potential to remove these three PAHs from water. This microbial consortium was exposed to the target PAHs at levels of 5, 10, 20, 50, and 100 mg L−1 for 14 days. PAH bioremoval was measured using the analytical technique of solid phase microextraction, followed by gas chromatography mass spectrometry (SPME-GC/MS). The results revealed that up to 90% of the target PAHs can be removed from water after 14 days at a concentration level of 100 mg L−1. The predominant group of microorganisms identified at the phylum taxonomic level were the Proteobacteria, while the Actinobacteria were the predominant subgroup. The removal of phenanthrene, naphthalene, and pyrene predominantly occurred in specimens of genera Stenotrophomonas, Williamsia, and Chitinophagaceae, respectively. This study demonstrates that the use of specific microorganisms is an alternative method of reducing PAH levels in water. PMID:29757264

Bond Dissociation Energies for Substituted Polycyclic Aromatic Hydrocarbons and Their Cations

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W.; Langhoff, Stephen R.; Arnold, James O. (Technical Monitor)

1998-01-01

The B3LYP/4-31G approach is used to compute bond energies for a series of substituted benzene, naphthalene, and anthracene molecules and their cations. The benzene bond energies are compared with experiment. The trends in the bond energies are discussed. The ionization energies are also reported and compared with available experiments.

Diversity of organotrophic bacteria, activity of dehydrogenases and urease as well as seed germination and root growth Lepidium sativum, Sorghum saccharatum and Sinapis alba under the influence of polycyclic aromatic hydrocarbons.

PubMed

Lipińska, Aneta; Wyszkowska, Jadwiga; Kucharski, Jan

2015-12-01

Polycyclic aromatic hydrocarbons are organic compounds with highly toxic, carcinogenic, and mutagenic properties, which adversely affect the basic biological parameters of the soil, including the count of microorganisms, and the enzymatic activity. In addition to disturbances to the biological activity of the soil, PAHs may also exhibit toxic effects on plants. In view of the above, the study involved testing aimed at the determination of the effects of polycyclic aromatic hydrocarbons in a form of naphthalene, phenanthrene, anthracene and pyrene on the count, colony development (CD) index, ecophysiological (EP) diversity index of organotrophic bacteria, and the activity of soil dehydrogenases and soil urease. Moreover, an attempt was made to determine the soil's resistance based on the activity of the above-listed enzymes, and the effect of polycyclic aromatic hydrocarbons on seed germination and root growth was assessed by Lepidium sativum, Sorghum saccharatum, and Sinapis alba. In addition, the species of bacteria found in a soil subjected to strong pressure of polycyclic aromatic hydrocarbons were isolated. The experiment was performed in a laboratory on samples of loamy sand. Polycyclic aromatic hydrocarbons were introduced into the soil in an amount of 0, 1000, 2000, and 4000 mg kg(-1) of soil dry matter. Germination and growth of cress (L. sativum), white mustard (S. alba), and sweet sorghum (S. saccharatum) were determined using Phytotoxkit tests. It was found that the tested PAHs increased the average colony counts of organotrophic soil bacteria; pyrene did so to the greatest extent (2.2-fold relative to non-contaminated soil), phenanthrene to the smallest extent (1.4-fold relative to non-contaminated soil). None of the PAHs changed the value of the bacterial colony development (CD) index, while anthracene and pyrene increased the value of the eco-physiological (EP) diversity indicator. PAHs lowered the activity of the tested enzymes. The activity of dehydrogenases was dependent on a greater extent by the type of hydrocarbon (54.56%) rather than by the dose (10.64%), while for the activity of urease, it was the opposite. The greater extent was dependent on dose (95.42%) rather than by type (0.21%). Dehydrogenases are characterised by greater resistance to the action of PAHs than urease. Based on seed germination and root growth, it has shown that S. alba is best suited, being the most vulnerable plant, while S. saccharatum is the least suited. Subjecting a soil to strong pressure of PAHs leads to disturbances to the biological parameters of the soil, seed germination, and root growth L. sativum, S. saccharatum, and S. alba.

Influence of processing in the prevalence of polycyclic aromatic hydrocarbons in a Portuguese traditional meat product.

PubMed

Roseiro, L C; Gomes, A; Santos, C

2011-06-01

The concentration of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in traditional dry/fermented sausage along distinct stages of processing under two different technological procedures (traditional and modified processes). The influence of product's position in the smoking room, on the variation of contaminants and in their migration dynamics from the outer into the inner part, was also followed up. Raw material mixtures presented expressive total PAH values, 106.17 μg kg(-1) in wet samples and 244.34 μg kg(-1) in dry mater (DM), expressing the frequent fire woods occurred in the regions pigs were extensively reared. Traditional processing produced a higher (p<0.01) total PAH levels comparatively to modified/industrial procedures, with mean values reaching 3237.10 and 1702.85 μg kg(-1) DM, respectively. Both, raw materials and final products, showed PAH profiles with light compounds representing about 99.0% of the total PAHs, mostly accounted by those having two rings (naphthalene-27.5%) or three rings (acenaphtene-16.9%; fluorene-27.1%; phenanthrene-19.5% and anthracene-3.9%). The benzo[a]pyrene (BaP) accumulated in traditional and modified processed products never surpassed the limit of 5 μg kg(-1) established by the EU legislation. PAHs in products hanged in bars closer to heating/smoking source speed up their transfer from the surface/outer portion to the inner part of the product. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biodegradation Ability and Catabolic Genes of Petroleum-Degrading Sphingomonas koreensis Strain ASU-06 Isolated from Egyptian Oily Soil

PubMed Central

Mostafa, Yasser M.; Shoreit, Ahmed

2014-01-01

Polycyclic aromatic hydrocarbons (PAHs) are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06) was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 as Sphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genes alkB, alkB1, nahAc, C12O, and C23O suggested that ASU-06 might possess genes for aliphatic and PAHs degradation, while PAH-RHDαGP gene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period. PMID:25177681

L-cysteine-capped core/shell/shell quantum dot-graphene oxide nanocomposite fluorescence probe for polycyclic aromatic hydrocarbon detection.

PubMed

Adegoke, Oluwasesan; Forbes, Patricia B C

2016-01-01

Environmental pollutants, such as the polycyclic aromatic hydrocarbons (PAHs), become widely distributed in the environment after emission from a range of sources, and they have potential biological effects, including toxicity and carcinogenity. In this work, we have demonstrated the analytical potential of a covalently linked L-cysteine-capped CdSeTe/ZnSe/ZnS core/shell/shell quantum dot (QD)-graphene oxide (GO) nanocomposite fluorescence probe to detect PAH compounds in aqueous solution. Water-soluble L-cysteine-capped CdSeTe/ZnSe/ZnS QDs were synthesized for the first time and were covalently bonded to GO. The fluorescence of the QD-GO nanocomposite was enhanced relative to the unconjugated QDs. Various techniques including TEM, SEM, HRSEM, XRD, Raman, FT-IR, UV/vis and fluorescence spectrophotometry were employed to characterize both the QDs and the QD-GO nanocomposite. Four commonly found priority PAH analytes namely; phenanthrene (Phe), anthracene (Ant), pyrene (Py) and naphthalene (Naph), were tested and it was found that each of the PAH analytes enhanced the fluorescence of the QD-GO probe. Phe was selected for further studies as the PL enhancement was significantly greater for this PAH. A limit of detection (LOD) of 0.19 µg/L was obtained for Phe under optimum conditions, whilst the LOD of Ant, Py and Naph were estimated to be ~0.26 µg/L. The fluorescence detection mechanism is proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and sources of polycyclic aromatic hydrocarbon (PAH) in marine environment of China

NASA Astrophysics Data System (ADS)

Zheng, Jinshu; Richardson, Bruce J.; Shouming, O.; Zheng, Jianhua

2004-06-01

Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8 11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.

A density-functional-theory study of biradicals from benzene to hexacene

NASA Astrophysics Data System (ADS)

Kim, Hyun-Jung; Wang, Xingyong; Ma, Jing; Cho, Jun-Hyung

2011-11-01

The singlet-triplet energy gap of biradicals created in benzene and polyacenes is investigated by density-functional-theory calculations. For the biradicals in benzene, naphthalene, anthracene, tetracene, pentacene, and hexacene, we find that the singlet state is energetically favored over the triplet state by 189, 191, 184, 199, 218, and 244 meV, respectively. The monotonous increase of the singlet-triplet energy gap from anthracene to hexacene is attributed to the enhanced stability of the singlet state for longer polyacenes. Our analysis shows that the spin density of the singlet state is delocalized over all benzene rings, but such a spin delocalization is not present for the triplet state.

Dearomatization of diesel oil using Pseudomonas sp.

PubMed

Khan, Samiya; Gupta, Sanjay; Gupta, Nidhi

2018-05-25

To improve the quality of diesel fuel via removal of aromatic compounds using Pseudomonas sp. In the present study Pseudomonas sp. was able to remove 94% of fluorene, 59% of phenanthrene, 49% of anthracene, 52% of fluoranthene, 45% of pyrene and 75% carbazole present in diesel oil. Additionally, it also does not affect the aliphatic content of fuel thus maintaining the carbon backbone of the fuel. Pseudomonas sp. is a potential biocatalyst that can be used in the refining industry.

1-[(Anthracen-9-yl)carbon­yl]-2,7-di­meth­oxy­naphthalene: a chain-like structure composed of face-to-face type dimeric mol­ecular aggregates

PubMed Central

Siqingaowa; Tsumuki, Takehiro; Ogata, Kazuki; Yonezawa, Noriyuki; Okamoto, Akiko

2016-01-01

The asymmetric unit of the title compound, C27H20O3, contains two independent mol­ecules (A and B). The anthracene ring system is connected to the 2,7-di­meth­oxy­naphthalene core in a twisted manner, with dihedral angles of 86.38 (5) and 79.36 (8)°, respectively, for conformers A and B. In the crystal, face-to-face type dimeric mol­ecular aggregates of each conformer are observed. The dimer of conformer A is formed by two pairs of C—H⋯π inter­actions, and that of conformer B by a pair of (sp 2)C—H⋯O hydrogen bonds. The dimers of conformer A are linked to each other via a π–π stacking inter­action between the anthracene rings to form a chain along the b axis and the chains are aligned along the c axis, forming a sheet structure. The dimers of conformer B are connected to each other via a couple of C—H⋯π inter­actions to form a chain along the b axis. The chains are aligned along the c axis through (sp 2)C—H⋯O=C hydrogen bonds, forming a sheet parallel to the bc plane. The sheets of conformers A and B are alternately stacked along the a axis via two kinds of inter­molecular (sp 2)C—H⋯O=C hydrogen bonds. PMID:27980839

Oxidation of polycyclic aromatic hydrocarbons under sulfate-reducing conditions

USGS Publications Warehouse

Coates, J.D.; Anderson, R.T.; Lovley, D.R.

1996-01-01

[14C]naphthalene and phenanthrene were oxidized to 14CO2 without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction was necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized.

Laboratory evidence for ionized polycyclic aromatic hydrocarbons in the interstellar medium

NASA Technical Reports Server (NTRS)

Szczepanski, Jan; Vala, Martin

1993-01-01

The infrared absorption from neutrals and cations of four PAHs - naphthalene, anthracene, pyrene, and perylene - integrated over the spectral regions corresponding to the interstellar bands are compared with astronomical observations. It is found that the interstellar bands cannot be explained solely on the basis of neutral PAH species, but that cations must be a significant, and in some cases dominant, component.

New anthracene derivatives as triplet acceptors for efficient green-to-blue low-power upconversion.

PubMed

Liang, Zuo-Qin; Sun, Bin; Ye, Chang-Qing; Wang, Xiao-Mei; Tao, Xu-Tang; Wang, Qin-Hua; Ding, Ping; Wang, Bao; Wang, Jing-Jing

2013-10-21

Three new anthracene derivatives [2-chloro-9,10-dip-tolylanthracene (DTACl), 9,10-dip-tolylanthracene-2-carbonitrile (DTACN), and 9,10-di(naphthalen-1-yl)anthracene-2-carbonitrile (DNACN)] were synthesized as triplet acceptors for low-power upconversion. Their linear absorption, single-photon-excited fluorescence, and upconversion fluorescence properties were studied. The acceptors exhibit high fluorescence yields in DMF. Selective excitation of the sensitizer Pd(II)octaethylporphyrin (PdOEP) in solution containing DTACl, DTACN, or DNA-CN at 532 nm with an ultralow excitation power density of 0.5 W cm(-2) results in anti-Stokes blue emission. The maximum upconversion quantum yield (Φ(UC) =17.4%) was obtained for the couple PdOEP/DTACl. In addition, the efficiency of the triplet-triplet energy transfer process was quantitatively studied by quenching experiments. Experimental results revealed that a highly effective acceptor for upconversion should combine high fluorescence quantum yields with efficient quenching of the sensitizer triplet. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Free-Radical Pathway to Hydrogenated Phenanthrene in Molecular Clouds-Low Temperature Growth of Polycyclic Aromatic Hydrocarbons.

PubMed

Thomas, Aaron M; Lucas, Michael; Yang, Tao; Kaiser, Ralf I; Fuentes, Luis; Belisario-Lara, Daniel; Mebel, Alexander M

2017-08-05

The hydrogen-abstraction/acetylene-addition mechanism has been fundamental to unravelling the synthesis of polycyclic aromatic hydrocarbons (PAHs) detected in combustion flames and carbonaceous meteorites like Orgueil and Murchison. However, the fundamental reaction pathways accounting for the synthesis of complex PAHs, such as the tricyclic anthracene and phenanthrene along with their dihydrogenated counterparts, remain elusive to date. By investigating the hitherto unknown chemistry of the 1-naphthyl radical with 1,3-butadiene, we reveal a facile barrierless synthesis of dihydrophenanthrene adaptable to low temperatures. These aryl-type radical additions to conjugated hydrocarbons via resonantly stabilized free-radical intermediates defy conventional wisdom that PAH growth is predominantly a high-temperature phenomenon and thus may represent an overlooked path to PAHs as complex as coronene and corannulene in cold regions of the interstellar medium like in the Taurus Molecular Cloud. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct observation of organic contaminant uptake, storage, and metabolism within plant roots.

PubMed

Wild, Edward; Dent, John; Thomas, Gareth O; Jones, Kevin C

2005-05-15

Two-photon excitation microscopy (TPEM) is used to visualize and track the uptake and movement of anthracene and phenanthrene from a contaminated growth medium into living unmodified roots of maize and wheat over a 56-day period. The degradation of anthracene was also directly observed within the cortex cells of both species. The power of this technique is that neither the plant nor the compound require altering (staining or sectioning) to visualize them, meaning they are in their natural form throughout the experiment. Initially both compounds bound to the epidermis along the zone of elongation, passing through the epidermal cells to reach the cortex within the root hair, and branching zones of the root. The PAHs entered the epidermis radially; however, once within the cortex cells this movement was dominated by slow lateral movement of both compounds toward the shoot. Highly focused "streams" of compound were observed to form over time; zones where phenanthrene concentrated extended up to 1500 microm in length over a 56-day period, for example, passing through several adjoining cells, and were detectable in cell walls and cell vacuoles. Radial movement was not observed to extend beyond the cortex cells to reach the vascular tissues of the plant. The longitudinal movement of both compounds was not observed to extend beyond the root base into the stem or vegetative parts of the plant. The lateral movement of both compounds within the cortex cells was dominated by movement within the cell walls, suggesting apoplastic flow through multiple cell walls, but with a low level of symplastic movement to transport compound into the cellular vacuoles. Degradation of anthracene to the partial breakdown products anthrone, anthraquinone, and hydroxyanthraquinone was observed directly in the zones of root elongation and branching. The technique and observations have important applications to the fields of agrochemistry and phytoremediation.

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 provide enough information to possibly create a stepping-stone for a brand new area in an unexplored frontier of chemistry.

Impacts of UV radiation and photomodification on the toxicity of PAHs to the higher plant Lemna gibba (duckweed)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiaodong Huang; Dixon, D.G.; Greenberg, B.M.

1993-06-01

The toxicity of polycyclic aromatic hydrocarbons (PAHs) can be enhanced by both biotic and abiotic processes. This is exemplified by light, which, by virtue of the extensive [pi]-orbital systems of PAHs, can be a major factor in PAH toxicity. Light activation of PAHs is known to occur via photosensitization reactions and potentially by photomodification of the chemicals to more toxic species. To examine the modes of PAH action in the light and determine if the photomodified compounds are hazardous, the authors investigated the photoinduced toxicity of anthracene, phenanthrene and benzo[a]pyrene to the aquatic higher plant Lemna gibba (a duckweed). Toxicitymore » end points were inhibition of growth and extent of chlorosis. Light did indeed activated the phytotoxicity of PAHs, with UV radiation more effective than visible light. Dose-response curves based on chemical concentration and light intensity revealed the order of phytotoxic strength to be anthracene > phenanthrene > benzo[a]pyrene. To explore whether photomodified PAHs were contributing to toxicity, the chemicals were irradiated before toxicity testing. The rates of photomodification of the three PAHs were rapid, and the relative velocities were coincident with the order of toxic strength. Furthermore, the photomodified PAHs were more hazardous to Lemna than the intact compounds. Because interpretations of the potential impacts of PAHs in the environment are based mostly on measurements of the structurally intact chemicals, the severity of PAH hazards is possibly underestimated.« less

A Novel Phenanthrene Dioxygenase from Nocardioides sp. Strain KP7: Expression in Escherichia coli

PubMed Central

Saito, Atsushi; Iwabuchi, Tokuro; Harayama, Shigeaki

2000-01-01

Nocardioides sp. strain KP7 grows on phenanthrene but not on naphthalene. This organism degrades phenanthrene via 1-hydroxy-2-naphthoate, o-phthalate, and protocatechuate. The genes responsible for the degradation of phenanthrene to o-phthalate (phd) were found by Southern hybridization to reside on the chromosome. A 10.6-kb DNA fragment containing eight phd genes was cloned and sequenced. The phdA, phdB, phdC, and phdD genes, which encode the α and β subunits of the oxygenase component, a ferredoxin, and a ferredoxin reductase, respectively, of phenanthrene dioxygenase were identified. The gene cluster, phdAB, was located 8.3 kb downstream of the previously characterized phdK gene, which encodes 2-carboxybenzaldehyde dehydrogenase. The phdCD gene cluster was located 2.9 kb downstream of the phdB gene. PhdA and PhdB exhibited moderate (less than 60%) sequence identity to the α and β subunits of other ring-hydroxylating dioxygenases. The PhdC sequence showed features of a [3Fe-4S] or [4Fe-4S] type of ferredoxin, not of the [2Fe-2S] type of ferredoxin that has been found in most of the reported ring-hydroxylating dioxygenases. PhdD also showed moderate (less than 40%) sequence identity to known reductases. The phdABCD genes were expressed poorly in Escherichia coli, even when placed under the control of strong promoters. The introduction of a Shine-Dalgarno sequence upstream of each initiation codon of the phdABCD genes improved their expression in E. coli. E. coli cells carrying phdBCD or phdACD exhibited no phenanthrene-degrading activity, and those carrying phdABD or phdABC exhibited phenanthrene-degrading activity which was significantly less than that in cells carrying the phdABCD genes. It was thus concluded that all of the phdABCD genes are necessary for the efficient expression of phenanthrene-degrading activity. The genetic organization of the phd genes, the phylogenetically diverged positions of these genes, and an unusual type of ferredoxin component suggest phenanthrene dioxygenase in Nocardioides sp. strain KP7 to be a new class of aromatic ring-hydroxylating dioxygenases. PMID:10735855

Microwave-assisted extraction and ultrasonic extraction to determine polycyclic aromatic hydrocarbons in needles and bark of Pinus pinaster Ait. and Pinus pinea L. by GC-MS.

PubMed

Ratola, Nuno; Lacorte, Sílvia; Barceló, Damià; Alves, Arminda

2009-01-15

Two different extraction strategies (microwave-assisted extraction (MAE) and ultrasonic extraction (USE)) were tested in the extraction of the 16 US Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) from pine trees. Extraction of needles and bark from two pine species common in the Iberian Peninsula (Pinus pinaster Ait. and Pinus pinea L.) was optimized using two amounts of sample (1g and 5 g) and two PAHs spiking levels (20 ng/g and 100 ng/g). In all cases, the clean-up procedure following extraction consisted in solid-phase extraction (SPE) with alumina cartridges. Quantification was done by gas chromatography (GC) with mass spectrometry (MS), using five deuterated PAH surrogate standards as internal standards. Limits of detection were globally below 0.2 ng/g. The method was robust for the matrices studied regardless of the extraction procedures. Recovery values between 70 and 130% were reached in most cases, except for high molecular weight PAHs (indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[ghi]perylene). A field study with naturally contaminated samples from eight sites (four in Portugal and four in Catalonia, Spain) showed that needles are more suitable biomonitors for PAHs, yielding concentrations from 2 to 17 times higher than those found in bark. The levels varied according to the sampling site, with the sum of the individual PAH concentrations between 213 and 1773 ng/g (dry weight). Phenanthrene was the most abundant PAH, followed by fluoranthene, naphthalene and pyrene.

Infrared Spectra of Polycyclic Aromatic Hydrocarbons: Nitrogen Substitution

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W.; Arnold, James O. (Technical Monitor)

1998-01-01

The B3LYP/4-31G approach is used to compute the harmonic frequencies of substituted naphthalene, anthracene, and their cations. The substitutions include cyano (CN), aminio (NH2), imino (NH), and replacement of a CH group by a nitrogen atom. All unique sites are considered, namely 1 and 2 for naphthalene and 1, 2, and 9 for an'tracene, except for the imino, where only 2-iminonaphthalene is studied. The IR spectra of these substituted species are compared with those of the unsubstituted molecules. The addition of a CN group does not significantly affect the spectra except to add the CN stretching frequency. Replacing a CH group by N has only a small effect on the IR spectra. The addition of the NH2 group dramatically affects the neutral spectra, giving it much of the character of the cation spectra. However, the neutral 2-irrinonaphthalene spectra looks more like that of naphthalene than like the 2-aminonaphthalene spectra.

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.

Characterization of a Naphthalene Dioxygenase Endowed with an Exceptionally Broad Substrate Specificity Toward Polycyclic Aromatic Hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jouanneau,Y.; Meyer, C.; Jakoncic, J.

In Sphingomonas CHY-1, a single ring-hydroxylating dioxygenase is responsible for the initial attack of a range of polycyclic aromatic hydrocarbons (PAHs) composed of up to five rings. The components of this enzyme were separately purified and characterized. The oxygenase component (ht-PhnI) was shown to contain one Rieske-type [2Fe-2S] cluster and one mononuclear Fe center per {alpha} subunit, based on EPR measurements and iron assay. Steady-state kinetic measurements revealed that the enzyme had a relatively low apparent Michaelis constant for naphthalene (K{sub m} = 0.92 {+-} 0.15 {mu}M) and an apparent specificity constant of 2.0 {+-} 0.3 M{sup -1} s{sup -1}.more » Naphthalene was converted to the corresponding 1,2-dihydrodiol with stoichiometric oxidation of NADH. On the other hand, the oxidation of eight other PAHs occurred at slower rates and with coupling efficiencies that decreased with the enzyme reaction rate. Uncoupling was associated with hydrogen peroxide formation, which is potentially deleterious to cells and might inhibit PAH degradation. In single turnover reactions, ht-PhnI alone catalyzed PAH hydroxylation at a faster rate in the presence of organic solvent, suggesting that the transfer of substrate to the active site is a limiting factor. The four-ring PAHs chrysene and benz[a]anthracene were subjected to a double ring-dihydroxylation, giving rise to the formation of a significant proportion of bis-cis-dihydrodiols. In addition, the dihydroxylation of benz[a]anthracene yielded three dihydrodiols, the enzyme showing a preference for carbons in positions 1,2 and 10,11. This is the first characterization of a dioxygenase able to dihydroxylate PAHs made up of four and five rings.« less

Temperature-dependent sorption of naphthalene, phenanthrene, and pyrene to low organic carbon aquifer sediments

USGS Publications Warehouse

Piatt, Joseph J.; Backhus, Debera A.; Capel, Paul 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 (Kd) 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 Kd and k2 values and the effect of temperature on Kd (e.g., low enthalpy of sorption) are consistent with sorbate partitioning between the aqueous phase and small amounts of organic matter (foc = 0.02%) on the sediments. The temperature dependence of Kd 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.

Evaluation of PAH contamination in soil treated with solid by-products from shale pyrolysis.

PubMed

Nicolini, Jaqueline; Khan, Muhammad Y; Matsui, M; Côcco, Lílian C; Yamamoto, Carlos I; Lopes, Wilson A; de Andrade, Jailson B; Pillon, Clenio N; Arizaga, Gregorio G Carbajal; Mangrich, Antonio S

2015-01-01

The aim of this work was to evaluate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in soils to which solid shale materials (SSMs) were added as soil conditioners. The SSMs were derived from the Petrosix pyrolysis process developed by Petrobras (Brazil). An improved ultrasonic agitation method was used to extract the PAHs from the solid samples (soils amended with SSMs), and the concentrations of the compounds were determined by gas chromatography coupled to mass spectrometry (GC-MS). The procedure provided satisfactory recoveries, detection limits, and quantification limits. The two-, three-, and four-ring PAHs were most prevalent, and the highest concentration was obtained for phenanthrene (978 ± 19 μg kg(-1) in a pyrolyzed shale sample). The use of phenanthrene/anthracene and fluoranthene/pyrene ratios revealed that the PAHs were derived from petrogenic rather than pyrogenic sources. The measured PAH concentrations did not exceed national or international limit values, suggesting that the use of SSMs as soil conditioners should not cause environmental damage.

Co-biodegradation of anthracene and naphthalene by the bacterium Acinetobacter johnsonii.

PubMed

Jiang, Yan; Qi, Hui; Zhang, Xian M

2018-04-16

NAP (Naphthalene) and ANT (anthracene) usually co-exist in environment and possessed interactional effects on their biodegradation in environment. Presently, a strain of Acinetobacter johnsonii was employed to degrade NAP and ANT in single- and dual-substrate systems. NAP was utilized as prefer substrate by cells to accelerate ANT biodegradation. As much as 200 mg L -1 ANT could be entirely degraded with 1,500 mg L -1 NAP, which was beyond bacterial potential in single substrate system. Especially, the shortest biodegradation period (103 h) for ANT was observed with the presence of 50 mg L -1 NAP. By contrast, ANT showed strong inhibition on NAP degradation, while the peak biodegradation of 1,950 mg L -1 NAP with 50 mg L -1 ANT could still proceed. By introducing an inhibition constant parameter to fit the inhibition on cells, modeling indicated the substrate inhibition for NAP and ANT over the concentrations of 174 and 49 mg L -1 , respectively. Furthermore, enzyme assay revealed the pathway of meta fission in NAP biodegradation due to the appearance of catechol 2,3-dioxygenase activity, and low-level lipase excretion was also found in both NAP and ANT biodegradation, but hardly affect NAP and ANT biodegradation in the present study. To research the interplay of NAP and ANT is conducive to targeted decontamination.

Combination of Liquid Chromatography with Multivariate Curve Resolution-Alternating Least-Squares (MCR-ALS) in the Quantitation of Polycyclic Aromatic Hydrocarbons Present in Paprika Samples.

PubMed

Monago-Maraña, Olga; Pérez, Rocío L; Escandar, Graciela M; Muñoz de la Peña, Arsenio; Galeano-Díaz, Teresa

2016-11-02

This work presents a strategy for quantitating polycyclic aromatic hydrocarbons (PAHs) in smoked paprika samples. For this, a liquid chromatographic method with fluorimetric detection (HPLC-FLD) was optimized. To resolve some interference co-eluting with the target analytes, the second-order multivariate curve resolution-alternating least-squares (MCR-ALS) algorithm has been employed combined with this liquid chromatographic method. Among the eight PAHs quantified (fluorene, phenanthrene, anthracene, pyrene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene) by HPLC-FLD, only in the case of fluorene, pyrene, and benzo[b]fluoranthene was it necessary to apply the second-order algorithm for their resolution. Limits of detection and quantitation were between 0.015 and 0.45 mg/kg and between 0.15 and 1.5 mg/kg, respectively. Good recovery results (>80%) for paprika were obtained via the complete extraction procedure, consisting of an extraction from the matrix and the cleanup of the extract by means of silica cartridges. Higher concentrations of chrysene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene were found in the paprika samples, with respect to the maximal amounts allowed for other spices that are under European Regulation (EU) N° 2015/1933.

Investigation of hydrophobic contaminants in an urban slough system using passive sampling - Insights from sampling rate calculations

USGS Publications Warehouse

McCarthy, K.

2008-01-01

Semipermeable membrane devices (SPMDs) were deployed in the Columbia Slough, near Portland, Oregon, on three separate occasions to measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds (OCs) in the slough. Concentrations of PAHs and OCs in SPMDs showed spatial and seasonal differences among sites and indicated that unusually high flows in the spring of 2006 diluted the concentrations of many of the target contaminants. However, the same PAHs - pyrene, fluoranthene, and the alkylated homologues of phenanthrene, anthracene, and fluorene - and OCs - polychlorinated biphenyls, pentachloroanisole, chlorpyrifos, dieldrin, and the metabolites of dichlorodiphenyltrichloroethane (DDT) - predominated throughout the system during all three deployment periods. The data suggest that storm washoff may be a predominant source of PAHs in the slough but that OCs are ubiquitous, entering the slough by a variety of pathways. Comparison of SPMDs deployed on the stream bed with SPMDs deployed in the overlying water column suggests that even for the very hydrophobic compounds investigated, bed sediments may not be a predominant source in this system. Perdeuterated phenanthrene (phenanthrene-d10). spiked at a rate of 2 ??g per SPMD, was shown to be a reliable performance reference compound (PRC) under the conditions of these deployments. Post-deployment concentrations of the PRC revealed differences in sampling conditions among sites and between seasons, but indicate that for SPMDs deployed throughout the main slough channel, differences in sampling rates were small enough to make site-to-site comparisons of SPMD concentrations straightforward. ?? Springer Science+Business Media B.V. 2007.

Endophytic Burkholderia fungorum DBT1 can improve phytoremediation efficiency of polycyclic aromatic hydrocarbons.

PubMed

Andreolli, Marco; Lampis, Silvia; Poli, Marika; Gullner, Gabor; Biró, Borbala; Vallini, Giovanni

2013-07-01

Burkholderia fungorum DBT1 is a bacterial strain isolated from an oil refinery discharge and capable of transforming dibenzothiophene, phenanthrene, naphthalene, and fluorene. In order to evaluate the influence of a policyclic aromatic hydrocarbon (PAH)-transforming bacterial strain on the phytoremediation of organic contaminants, B. fungorum DBT1 was inoculated into hybrid poplar (Populus deltoides×Populus nigra). The poplar plants were grown for 18-wk with or without naphthalene, phenanthrene, fluorene and dibenzothiophene (488mgkg(-1) soil each) in non-sterile sand-peat substrate. Evidences were gained that B. fungorum DBT1 was present in high concentration in poplar root tissues (2.9-9.5×10(3)CFUg(-1)), while the strain was not detected in stem, leaves and rhizosphere. When poplar was planted in uncontaminated substrate, the infection caused negative effects on biomass index, leaves and stem dry weight, without showing however any disease symptoms. On the other hand, plants inoculated with the strain DBT1 resulted in better tolerance against the toxic effects of PAHs, in terms of root dry weight. Although the presence of plants acted as the main effective treatment for PAH dissipation (82-87%), the inoculum with DBT1 strain lead to the highest PAH abatement (up to 99%). In the present study, an environmental isolate with proper metabolic features was demonstrated to be possibly suitable as a poplar endophyte for improving microbe-assisted phytoremediation in PAH contaminated matrices. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modular, Metal-Catalyzed Cycloisomerization Approach to Angularly Fused Polycyclic Aromatic Hydrocarbons and Their Oxidized Derivatives

PubMed Central

Thomson, Paul F.; Parrish, Damon; Pradhan, Padmanava; Lakshman, Mahesh K.

2015-01-01

Palladium-catalyzed cross-coupling reactions of 2-bromobenzaldehyde and 6-bromo-2,3-dimethoxybenzaldehyde with 4-methyl-1-naphthaleneboronic acid and acenaphthene-5-boronic acid gave corresponding o-naphthyl benzaldehydes. Corey–Fuchs olefination followed by reaction with n-BuLi led to various 1-(2-ethynylphenyl)naphthalenes. Cycloisomerization of individual 1-(2-ethynylphenyl)naphthalenes to various benzo[c]phenanthrene (BcPh) analogues was accomplished smoothly with catalytic PtCl2 in PhMe. In the case of 4,5-dihydrobenzo[l]acephenanthrylene, oxidation with DDQ gave benzo[l]acephenanthrylene. The dimethoxy-substituted benzo[c]phenanthrenes were demethylated with BBr3 and oxidized to the ortho-quinones with PDC. Reduction of these quinones with NaBH4 in THF/EtOH in an oxygen atmosphere gave the respective dihydrodiols. Exposure of the dihydrodiols to N-bromoacetamide in THF-H2O led to bromohydrins that were cyclized with Amberlite IRA 400 HO− to yield the series 1 diol epoxides. Epoxidation of the dihydrodiols with mCPBA gave the isomeric series 2 diol epoxides. All of the hydrocarbons as well as the methoxy-substituted ones were crystallized and analyzed by X-ray crystallography, and these data are compared to other previously studied BcPh derivatives. The methodology described is highly modular and can be utilized for the synthesis of a wide variety of angularly fused polycyclic aromatic hydrocarbons and their putative metabolites and/or other derivatives. PMID:26196673

Carboxylation as an initial reaction in the anaerobic metabolism of naphthalene and phenanthrene by sulfidogenic consortia.

PubMed Central

Zhang, X; Young, L Y

1997-01-01

The anaerobic biodegradation of naphthalene (NAP) and phenanthrene (PHE) was investigated by using sediment collected from the Arthur Kill in New York/New Jersey harbor. The initial cultures were composed of 10% sediment and 90% mineral medium containing 20 mM sulfate. Complete loss of NAP and PHE (150 to 200 muM) was observed after 150 days of incubation. Upon refeeding, NAP and PHE were utilized within 14 days. The utilization of both compounds was inhibited in the presence of 20 mM molybdate. [14C]NAP and [14C]PHE were mineralized to 14CO2. The activities could be maintained and propagated by subculturing in mineral medium. In the presence of halogenated analogs, 2-naphthoate was detected in NAP-utilizing enrichments. The mass spectrum of the derivatized 2-napththoate from the enrichment supplemented with both [13C]bicarbonate and NAP indicates the incorporation of 13CO2 into NAP. In the PHE-utilizing enrichment, a metabolite was detected by both high-pressure liquid chromatography and gas chromatography-mass spectrometry analyses. The molecular ion and fragmentation pattern of its mass spectrum indicate that it was phenanthrenecarboxylic acid. The results obtained with [13C] bicarbonate indicate that 13CO2 was incorporated into PHE. It appears, therefore, that carboxylation is an initial key reaction for the anaerobic metabolism and NAP and PHE. To our knowledge, this is the first report providing evidence for intermediates of PAH degradation under anaerobic conditions. PMID:9471963

Dissolved organic matter effects on the performance of a barrier to polycyclic aromatic hydrocarbon transport by groundwater

NASA Astrophysics Data System (ADS)

Moon, Jung-Won; Goltz, Mark N.; Ahn, Kyu-Hong; Park, Jae-Woo

2003-02-01

In order to contain the movement of organic contaminants in groundwater, a subsurface sorption barrier consisting of sand or clay minerals coated with a cationic surfactant has been proposed. The effectiveness of such a sorption barrier might be affected by the presence of dissolved organic matter (DOM) in the groundwater. To study the impact of DOM on barrier performance, a series of batch experiments were performed by measuring naphthalene and phenanthrene sorption onto sand coated with cetylpyridinium chloride (CPC) and bentonite coated with hexadecyltrimethylammonium bromide (HDTMA) in the presence of various concentrations of DOM. The overall soil-water distribution coefficient ( K*) of naphthalene and phenanthrene onto CPC-coated sand decreased with increasing DOM concentration, whereas the K* of the compounds onto HDTMA-coated bentonite slightly increased with increasing DOM concentration. To describe the overall distribution of polycyclic aromatic hydrocarbons (PAHs) in the systems, a competitive multiphase sorption (CMS) model was developed and compared with an overall mechanistic sorption (OMS) model. The modeling studies showed that while the OMS model did not explain the CPC-coated sand experimental results, a model that included competitive sorption between DOM and PAH did. The experimental results and the modeling study indicated that there was no apparent competition between DOM and PAH in the HDTMA-coated bentonite system, and indicated that in groundwater systems with high DOM, a barrier using HDTMA-coated bentonite might be more effective.

Polyphasic approach for assessing changes in an autochthonous marine bacterial community in the presence of Prestige fuel oil and its biodegradation potential.

PubMed

Jiménez, Núria; Viñas, Marc; Guiu-Aragonés, Cèlia; Bayona, Josep M; Albaigés, Joan; Solanas, Anna M

2011-08-01

A laboratory experiment was conducted to identify key hydrocarbon degraders from a marine oil spill sample (Prestige fuel oil), to ascertain their role in the degradation of different hydrocarbons, and to assess their biodegradation potential for this complex heavy oil. After a 17-month enrichment in weathered fuel, the bacterial community, initially consisting mainly of Methylophaga species, underwent a major selective pressure in favor of obligate hydrocarbonoclastic microorganisms, such as Alcanivorax and Marinobacter spp. and other hydrocarbon-degrading taxa (Thalassospira and Alcaligenes), and showed strong biodegradation potential. This ranged from >99% for all low- and medium-molecular-weight alkanes (C(15)-C(27)) and polycyclic aromatic hydrocarbons (C(0)- to C(2)- naphthalene, anthracene, phenanthrene, dibenzothiophene, and carbazole), to 75-98% for higher molecular-weight alkanes (C(28)-C(40)) and to 55-80% for the C(3) derivatives of tricyclic and tetracyclic polycyclic aromatic hydrocarbons (PAHs) (e.g., C(3)-chrysenes), in 60 days. The numbers of total heterotrophs and of n-alkane-, aliphatic-, and PAH degraders, as well as the structures of these populations, were monitored throughout the biodegradation process. The salinity of the counting medium affects the counts of PAH degraders, while the carbon source (n-hexadecane vs. a mixture of aliphatic hydrocarbons) is a key factor when counting aliphatic degraders. These limitations notwithstanding, some bacterial genera associated with hydrocarbon degradation (mainly belonging to α- and γ-Proteobacteria, including the hydrocarbonoclastic Alcanivorax and Marinobacter) were identified. We conclude that Thalassospira and Roseobacter contribute to the degradation of aliphatic hydrocarbons, whereas Mesorhizobium and Muricauda participate in the degradation of PAHs.

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.

Laboratory studies to characterize the efficacy of sand capping a coal tar-contaminated sediment.

PubMed

Hyun, Seunghun; Jafvert, Chad T; Lee, Linda S; Rao, P Suresh C

2006-06-01

Placement of a microbial active sand cap on a coal tar-contaminated river sediment has been suggested as a cost effective remediation strategy. This approach assumes that the flux of contaminants from the sediment is sufficiently balanced by oxygen and nutrient fluxes into the sand layer such that microbial activity will reduce contaminant concentrations within the new benthic zone and reduce the contaminant flux to the water column. The dynamics of such a system were evaluated using batch and column studies with microbial communities from tar-contaminated sediment under different aeration and nutrient inputs. In a 30-d batch degradation study on aqueous extracts of coal tar sediment, oxygen and nutrient concentrations were found to be key parameters controlling the degradation rates of polycyclic aromatic hydrocarbons (PAHs). For the five PAHs monitored (naphthalene, fluorene, phenanthrene, anthracene, and pyrene), degradation rates were inversely proportional to molecular size. For the column studies, where three columns were packed with a 20-cm sand layer on the top of a 5 cm of sediment layer, flow was established to sand layers with (1) aerated water, (2) N(2) sparged water, or (3) HgCl(2)-sterilized N(2) sparged water. After steady-state conditions, PAH concentrations in effluents were the lowest in the aerated column, except for pyrene, whose concentration was invariant with all effluents. These laboratory scale studies support that if sufficient aeration can be achieved in the field through either active and passive means, the resulting microbially active sand layer can improve the water quality of the benthic zone and reduce the flux of many, but not all, PAHs to the water column.

Cement-based stabilization/solidification of oil refinery sludge: Leaching behavior of alkanes and PAHs.

PubMed

Karamalidis, Athanasios K; Voudrias, Evangelos A

2007-09-05

Stabilization/solidification is a process widely applied for the immobilization of inorganic constituents of hazardous wastes, especially for metals. Cement is usually one of the most common binders for that purpose. However, limited results have been presented on immobilization of hydrocarbons in cement-based stabilized/solidified petroleum solid waste. In this study, real oil refinery sludge samples were stabilized and solidified with various additions of I42.5 and II42.5 cement (Portland and blended cement, respectively) and subject to leaching. The target analytes were total petroleum hydrocarbons, alkanes and 16 polycyclic aromatic hydrocarbons of the EPA priority pollutant list. The experiments showed that the waste was confined in the cement matrix by macroencapsulation. The rapture of the cement structure led to the increase of leachability for most of the hydrocarbons. Leaching of n-alkanes from II42.5 cement-solidified samples was lower than that from I42.5 solidified samples. Leaching of alkanes in the range of n-C(10) to n-C(27) was lower than that of long chain alkanes (>n-C(27)), regardless the amount of cement addition. Generally, increasing the cement content in the solidified waste samples, increased individual alkane leachability. This indicated that cement addition resulted in destabilization of the waste. Addition of I42.5 cement favored immobilization of anthracene, benzo[a]anthracene, benzo[b]fluoroanthene, benzo[k]fluoroanthene, benzo[a]pyrene and dibenzo[a,h]anthracene. However, addition of II42.5 favored 5 out of 16, i.e., naphthalene, anthracene, benzo[b]fluoroanthene, benzo[k]fluoroanthene and dibenzo[a,h]anthracene.

Immune effects of HFO on European sea bass, Dicentrarchus labrax, and Pacific oyster, Crassostrea gigas.

PubMed

Bado-Nilles, Anne; Quentel, Claire; Auffret, Michel; Le Floch, Stéphane; Gagnaire, Béatrice; Renault, Tristan; Thomas-Guyon, Hélène

2009-07-01

The European sea bass, Dicentrarchus labrax, and the Pacific oyster, Crassostrea gigas, were exposed to a soluble fraction of heavy fuel oil for 5 and 9 days, respectively. The organisms were then transferred to non-contaminated seawater for 1 month. The bioaccumulation and elimination of PAHs in contaminated tissues were dissimilar between species. In fish, acenaphthene and naphthalene were detected and naphthalene was still detectable 30 days after the beginning of the recovery period. In oysters, on the other hand, pyrene and phenanthrene were bioaccumulated and 14 days after exposure no more PAHs were detected. Concerning innate immune parameters, the increase of haemolytic activity of the alternative complement pathway in fish and the reduction of phenoloxidase activity in oysters endured, respectively, 1 and 2 weeks in contaminated organisms. This indicates that these two enzymatic cascades could be quite useful for monitoring pollution by oil.

Azomethine diimides end-capped with anthracene moieties: Experimental and theoretical investigations

NASA Astrophysics Data System (ADS)

Schab-Balcerzak, Ewa; Grucela, Marzena; Malecki, Grzegorz; Kotowicz, Sonia; Siwy, Mariola; Janeczek, Henryk; Golba, Sylwia; Praski, Aleksander

2017-01-01

New arylene bisimide derivatives containing imine linkages and anthracene units were synthesized. Azomethine diimides were prepared via condensation reaction of 9-anthracenecarboxaldehyde and diamines with phthalic diimide or naphthalene diimide core and Schiff base linkers. They were characterized by FTIR spectroscopy, elemental analysis and mass spectrometry (MALDI-TOF-MS). The synthesized compounds exhibited high resistance against thermal decomposition up to 400 °C. Investigated compounds are electrochemically active and undergo reversible electrochemical reduction and irreversible oxidation processes as was found in cyclic voltammetry studies. The photoluminescence measurements of synthesized compounds in solid state as thin film on glass substrate revealed their ability to emission of the blue light with quantum yield efficiency about 2%. The electronic structure and spectroscopic properties of prepared azomethine diimides were also calculated by the density functional theory (DFT). The electrical properties of the diimide derivatives were preliminary investigated by current-voltage measurements.

Preparation of Silver Nanoparticles from Synthetic and Natural Sources: Remediation Model for PAHs

NASA Astrophysics Data System (ADS)

Abbasi, Maryam; Saeed, Fatima; Rafique, Uzaira

2014-06-01

The emergence of nanoscience and technology is gaining popularity with an increasing demand for metal nanoparticles applicability in various areas such as electronics, catalysis, chemistry, energy and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques, where the chemicals used are quite often toxic and flammable. In this work, an attempt is made to compare the efficiency of two different synthesis methods and application of each for the remediation of poly aromatic hydrocarbons (PAHs). In this regard, silver nanoparticles are prepared by green and wet chemical method using plant extract of garlic (Allium sativum). The extract is known to reduce the metal during synthesis and acts as stabilizing ligand. These synthesized silver nanoparticles (Agp) and (AgW) were applied as adsorbents in synthetic batch mode experiments at varying parameters of pH and temperature. A concentration of 0.01mg/L of Phenanthrene, Anthracene, and Pyrene were induced at fixed dosage of 1mg/Kg of adsorbent. Residual concentration of each PAH was analyzed on UV-Visible spectrophotometer. The results indicated that both adsorbents follow the sequence of Phenanthrene>Pyrene>Anthracene with optimal removal of higher than 85% in each case. A distinguishing privilege is attained by Agp adsorbent showing 3, 3 and 11 orders of magnitude higher efficiency than Agw. It may be attributed to more functional groups in the plant extract participating in binding of PAH to the surface. Each synthesized adsorbents was characterized by FTIR, SEM and EDX. The average particle size was determined to be of the order of 13-26 nm. The study concludes the use of alternate economical and green adsorbents for control of poly aromatic hydrocarbons (PAHs).

Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill.

PubMed

Ke, L; Wong, Teresa W Y; Wong, Y S; Tam, Nora F Y

2002-01-01

The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10 m x 10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2,135 ng g(-1), and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2,135 (30 days) to 1,196 ng g(-1) (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (>10) and low values of fluoranthene to pyrene ratio (0.3-0.4).

Magnetic microsphere-confined graphene for the extraction of polycyclic aromatic hydrocarbons from environmental water samples coupled with high performance liquid chromatography-fluorescence analysis.

PubMed

Wang, Weina; Ma, Ruiyang; Wu, Qiuhua; Wang, Chun; Wang, Zhi

2013-06-07

In this paper, a magnetic microsphere-confined graphene adsorbent (Fe3O4@SiO2-G) was fabricated and used for the extraction of five polycyclic aromatic hydrocarbons (fluorene, anthracene, phenanthrene, fluoranthene and pyrene) from environmental water samples prior to high performance liquid chromatography with fluorescence detection. The Fe3O4@SiO2-G was characterized by various instrumental methods. Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe3O4@SiO2-G, the pH and ionic strength of sample solution, the extraction time and the desorption conditions, were investigated. Due to the high surface area and excellent adsorption capacity of the Fe3O4@SiO2-G, satisfactory extraction can be achieved with only 15mg of the adsorbent per 250mL solution and 5min extraction. Under the optimum conditions, a linear response was observed in the concentration range of 5-1500ngL(-1) for fluorene, 2.5-1500ngL(-1) for anthracene and 15-1500ngL(-1) for phenanthrene, fluoranthene and pyrene, with the correlation coefficients (r) ranging from 0.9897 to 0.9961. The limits of detection (S/N=3) of the method were between 0.5 and 5.0ngL(-1). The relative standard deviations (RSDs) were less than 5.6%. The recoveries of the method were in the range between 83.2% and 108.2%. The results indicated that this graphene-based magnetic nanocomposite had a great adsorptive ability toward the five polycyclic aromatic hydrocarbons from environmental water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

[Transport and differentiation of polycyclic aromatic hydrocarbons in air from Dashiwei karst Sinkholes in Guangxi, China].

PubMed

Kong, Xiang-Sheng; Qi, Shi-Hua; Sun, Qian; Huang, Bao-Jian

2012-12-01

The typical karst Dashiwei Sinkholes located in Leye County, Guangxi were chosen as the study object. The air samples from the opening of Dashiwei Sinkholes to the underground river profiles were collected by polyurethane foam passive samplers (PUF-PAS), and the meteorological parameters were observed. The 16 PAHs were analyzed using GC-MS. The results showed that the total PAHs concentration in air in Dashiwei Sinkholes ranged from 33.76 ng x d(-1) to 150.86 ng x d(-1), with an average of 80.36 ng x d(-1). The mean concentrations in the cliff, the bottom and the underground river profiles were 67.17, 85.36 and 101.67 ng x d(-1), respectively. The 2-3 rings PAHs (including phenanthrene, anthracene, napnthalene and fluorene) accounted for 87.97% of the total of PAHs. The transport and accumulation processes of PAHs in air in Dashiwei Sinkholes were: the ground to the cliff section to the bottom section and then to the underground river, and the total PAHs concentrations showed an obvious increasing tendency with the decrease in altitude or increase in the length of the underground river. Low molecular weight PAHs compounds (including phenanthrene, anthracene, flourene and fluoranthene) in air went through differentiation at the bottom of the west peak, the bottom of the sinkhole and the underground river. The primary sources of PAHs were pyrogenic sources with atmosphere transport. Ambient temperature was the predominating factor influencing the transport and accumulation of gas phase PAHs in Dashiwei Sinkholes, following by wind speed, wind direction and relative humidity. Relative humidity and the temperature were the predominating factors influencing the differentiation, following by wind speed and wind direction. As a whole, a "cold trapping effect" of POPs was showed obviously in Dashiwei Sinkholes.

Anaerobic Degradation of Benzene and Polycyclic Aromatic Hydrocarbons.

PubMed

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

2016-01-01

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

Dibenzo[a,f]perylene bisimide: effects of introducing two fused rings.

PubMed

Chaolumen; Enno, Hiroki; Murata, Michihisa; Wakamiya, Atsushi; Murata, Yasujiro

2014-11-01

Perylene bisimides (PBIs) are fascinating dyes with various potential applications. To study the effects of introducing a dibenzo-fused structure to the perylene moiety, π-extended PBI derivatives with a dibenzo-fused structure at both of the a and f bonds were synthesized. The twisted structure was characterized by X-ray crystal structure analysis. In the cyclic voltammograms, the dibenzo[a,f]-fused PBI showed a reversible oxidation wave at much less positive potential, relative to a dibenzo[a,o]-fused PBI derivative. These data indicated that two ring fusions at both sides of a naphthalene moiety, which construct a tetracene core, effectively raise the HOMO level compared to fusion of one ring at each naphthalene moiety (two anthracene cores). The dibenzo[a,f]-fused PBI derivative showed an absorption band at 735 nm with a shoulder band reaching 900 nm. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The influence of black carbon on the sorption and desorption of two model PAHs in natural soils.

PubMed

Chi, Fung-Hwa

2014-01-01

Black carbons (BC) which result from the incomplete combustion of farm waste [man-made (burned) BC] are highly absorbent. In Taiwan, the burning of farm waste known as slash and burn is common. The BCs from the burning may present an environmental challenge. Little is known about the effect of BCs on the transport of hydrophobic organic contaminants (HOC). This study investigates the sorption of anthracene and naphthalene to BCs in soil and efficiency of the surfactants Tween 80 and Triton X-100 in their removal. Both surfactants demonstrated 2-6 times increased solubility in the soils with the addiction of BC. Column experiments were performed to imitate the transportation of these contaminants in groundwater through soils before and after adding BC produced by burning farm waste in the lab. We found significantly increased sorption of anthracene in soil added with BCs produced in the lab, suggesting that fraction of organic carbon (foc) can contribute to sorption of such HOCs. Sorption of naphthalene was increased but not significantly. Comparing the concentrations of contaminants, we found the soil containing BC from burned farm waste absorbed HOC more efficiently than the organic BC (naturally-occurring) in the original soil. Therefore, sorption capacity and influence on the transport of HOC cannot be estimated simply by the foc of the soil because the two BCs differ greatly in their sorption ability. BC from farm waste absorbs more contaminants than naturally occurring BC in the soil.

Relationship between chemical composition and oxidative potential of secondary organic aerosol from polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Wang, Shunyao; Ye, Jianhuai; Soong, Ronald; Wu, Bing; Yu, Legeng; Simpson, André J.; Chan, Arthur W. H.

2018-03-01

Owing to the complex nature and dynamic behaviors of secondary organic aerosol (SOA), its ability to cause oxidative stress (known as oxidative potential, or OP) and adverse health outcomes remains poorly understood. In this work, we probed the linkages between the chemical composition of SOA and its OP, and investigated impacts from various SOA evolution pathways, including atmospheric oligomerization, heterogeneous oxidation, and mixing with metal. SOA formed from photooxidation of the two most common polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) were studied as model systems. OP was evaluated using the dithiothreitol (DTT) assay. The oligomer-rich fraction separated by liquid chromatography dominates DTT activity in both SOA systems (52 ± 10 % for naphthalene SOA (NSOA), and 56 ± 5 % for phenanthrene SOA (PSOA)). Heterogeneous ozonolysis of NSOA was found to enhance its OP, which is consistent with the trend observed in selected individual oxidation products. DTT activities from redox-active organic compounds and metals were found to be not additive. When mixing with highly redox-active metal (Cu), OP of the mixture decreased significantly for 1,2-naphthoquinone (42 ± 7 %), 2,3-dihydroxynaphthalene (35 ± 1 %), NSOA (50 ± 6 %), and PSOA (43 ± 4 %). Evidence from proton nuclear magnetic resonance (1H NMR) spectroscopy illustrates that such OP reduction upon mixing can be ascribed to metal-organic binding interactions. Our results highlight the role of aerosol chemical composition under atmospheric aging processes in determining the OP of SOA, which is needed for more accurate and explicit prediction of the toxicological impacts from particulate matter.

Cancer risk assessment, indicators, and guidelines for polycyclic aromatic hydrocarbons in the ambient air.

PubMed Central

Boström, Carl-Elis; Gerde, Per; Hanberg, Annika; Jernström, Bengt; Johansson, Christer; Kyrklund, Titus; Rannug, Agneta; Törnqvist, Margareta; Victorin, Katarina; Westerholm, Roger

2002-01-01

Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs in Sweden. In Stockholm, the sum of 14 different PAHs is 100-200 ng/m(3) at the street-level site, the most abundant being phenanthrene. Benzo[a]pyrene (B[a]P) varies between 1 and 2 ng/m(3). Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA. B[a]P is the main indicator of carcinogenic PAHs. Fluoranthene is an important volatile PAH because it occurs at high concentrations in ambient air and because it is an experimental carcinogen in certain test systems. Thus, fluoranthene is suggested as a complementary indicator to B[a]P. The most carcinogenic PAH identified, dibenzo[a,l]pyrene, is also suggested as an indicator, although it occurs at very low concentrations. Quantitative cancer risk estimates of PAHs as air pollutants are very uncertain because of the lack of useful, good-quality data. According to the World Health Organization Air Quality Guidelines for Europe, the unit risk is 9 X 10(-5) per ng/m(3) of B[a]P as indicator of the total PAH content, namely, lifetime exposure to 0.1 ng/m(3) would theoretically lead to one extra cancer case in 100,000 exposed individuals. This concentration of 0.1 ng/m(3) of B[a]P is suggested as a health-based guideline. Because the carcinogenic potency of fluoranthene has been estimated to be approximately 20 times less than that of B[a]P, a tentative guideline value of 2 ng/m(3) is suggested for fluoranthene. Other significant PAHs are phenanthrene, methylated phenanthrenes/anthracenes and pyrene (high air concentrations), and large-molecule PAHs such as dibenz[a,h]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and indeno[1,2,3-cd]pyrene (high carcinogenicity). Additional source-specific indicators are benzo[ghi]perylene for gasoline vehicles, retene for wood combustion, and dibenzothiophene and benzonaphthothiophene for sulfur-containing fuels. PMID:12060843

Quantum control of coherent π -electron ring currents in polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Mineo, Hirobumi; Fujimura, Yuichi

2017-12-01

We present results for quantum optimal control (QOC) of the coherent π electron ring currents in polycyclic aromatic hydrocarbons (PAHs). Since PAHs consist of a number of condensed benzene rings, in principle, there exist various coherent ring patterns. These include the ring current localized to a designated benzene ring, the perimeter ring current that flows along the edge of the PAH, and the middle ring current of PAHs having an odd number of benzene rings such as anthracene. In the present QOC treatment, the best target wavefunction for generation of the ring current through a designated path is determined by a Lagrange multiplier method. The target function is integrated into the ordinary QOC theory. To demonstrate the applicability of the QOC procedure, we took naphthalene and anthracene as the simplest examples of linear PAHs. The mechanisms of ring current generation were clarified by analyzing the temporal evolutions of the electronic excited states after coherent excitation by UV pulses or (UV+IR) pulses as well as those of electric fields of the optimal laser pulses. Time-dependent simulations of the perimeter ring current and middle ring current of anthracene, which are induced by analytical electric fields of UV pulsed lasers, were performed to reproduce the QOC results.

Polycyclic aromatic hydrocarbons (PAHs) skin permeation rates change with simultaneous exposures to solar ultraviolet radiation (UV-S).

PubMed

Hopf, Nancy B; Spring, Philipp; Hirt-Burri, Nathalie; Jimenez, Silvia; Sutter, Benjamin; Vernez, David; Berthet, Aurelie

2018-05-01

Road construction workers are simultaneously exposed to two carcinogens; solar ultraviolet (UV-S) radiation and polycyclic aromatic hydrocarbons (PAHs) in bitumen emissions. The combined exposure may lead to photogenotoxicity and enhanced PAH skin permeation rates. Skin permeation rates (J) for selected PAHs in a mixture (PAH-mix) or in bitumen fume condensate (BFC) with and without UV-S co-exposures were measured with in vitro flow-through diffusion cells mounted with human viable skin and results compared. Possible biomarkers were explored. Js were greater with UV-S for naphthalene, anthracene, and pyrene in BFC (0.08-0.1 ng/cm 2 /h) compared to without (0.02-0.26 ng/cm 2 /h). This was true for anthracene, pyrene, and chrysene in the PAH-mix. Naphthalene and benzo(a)pyrene (BaP) in the PAH-mix had greater Js without (0.97-13.01 ng/cm 2 /h) compared to with UV-S (0.40-6.35 ng/cm 2 /h). Time until permeation (T lags ) in the PAH-mix were generally shorter compared to the BFC, and they ranged from 1 to 13 h. The vehicle matrix could potentially be the reason for this discrepancy as BFC contains additional not identified substances. Qualitative interpretation of p53 suggested a dose-response with UV-S, and somewhat with the co-exposures. MMP1, p65 and cKIT were not exploitable. Although not statistically different, PAHs permeate human viable skin faster with simultaneous exposures to UV. Copyright © 2018 Elsevier B.V. All rights reserved.

Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbon Cations. 3; The Members

NASA Technical Reports Server (NTRS)

Hudgins, D. M.; Allamandola, L. J.; Wittebon, Fred C. (Technical Monitor)

1994-01-01

In spite of the fact that the infrared spectroscopic properties of only a few isolated ionized polycyclic aromatic hydrocarbons (PAHs) are known, gaseous, ionized PAHs are thought to be responsible for a very common family of infrared interstellar emission bands. In order to provide a data base to test this hypothesis and, if borne out, to use this emission band family as a probe of many different interstellar environments, we are carrying out a thorough study of the infrared spectroscopic properties of neutral and ionized PAHs in argon matrices. Here we present the near and mid-infrared spectra of the cations of the five most thermodynamically favored PAHs up to coronene: phenanthrene, pyrene, benzo[e]pyrene, benzo[ghilperylene, and coronene. The properties of naphthalene, the first member of the series, are given elsewhere. The spectra of perdeuterated phenanthrene and pyrene are also reported. For those molecules which have been previously studied (pyrene, d(10)-pyrene, and coronene), band positions and relative intensities are in agreement. In all cases we report additional features. Absolute integrated absorbance values are given for the phenanthrene, perdeutero-phenanthrene, pyrene, benzo[ghi]perylene, and coronene cations. With the exception of coronene,the cation bands corresponding to the CC modes are typically 2-5 times more intense than those of the CH out-of-plane bending vibrations. For the cations the CC stretching and CH in-plane bending modes give rise to bands which are an order of magnitude stronger than for the neutral species, and the CH out-of-plane bends produce bands which are 5-20 times weaker than in the neutral species. This behavior is similar to that found in most other PAH cations studied to date. The astronomical implications of these PAH cation spectra are also discussed.

[Simultaneous determination of 15 polycyclic aromatic hydrocarbons in cigarette filter by gas chromatography-tandem mass spectrometry].

PubMed

Zhang, Xiaotao; Zhang, Li; Ruan, Yibin; Wang, Weiwei; Ji, Houwei; Wan, Qiang; Lin, Fucheng; Liu, Jian

2017-10-08

A method for the simultaneous determination of 15 polycyclic aromatic hydrocarbons in cigarette filter was developed by isotope internal standard combined with gas chromatography-tandem mass spectrometry. The cigarette filters were extracted with dichloromethane, and the extract was filtered with 0.22 μm organic phase membrane. The samples were isolated by DB-5MS column (30 m×0.25 mm, 0.25 μm) and detected using multiple reaction monitoring mode of electron impact source under positive ion mode. The linearities of the 15 polycyclic aromatic hydrocarbons (acenapthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, ben[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenzo[ a,h ]anthracene, benzo[ g,h,i ]perylene and indeno[1,2,3- c,d ]pyrene) were good, and the correlation coefficients ( R 2 ) ranged from 0.9914 to 0.9999. The average recoveries of the 15 polycyclic aromatic hydrocarbons were 81.6%-109.6% at low, middle and high spiked levels, and the relative standard deviations were less than 16%, except that the relative standard deviation of fluorene at the low spiked level was 19.2%. The limits of detection of the 15 polycyclic aromatic hydrocarbons were 0.02 to 0.24 ng/filter, and the limits of quantification were 0.04 to 0.80 ng/filter. The method is simple, rapid, accurate, sensitive and reproducible. It is suitable for the quantitative analysis of the 15 polycyclic aromatic hydrocarbons in cigarette filters.

Water- and Bed-Sediment Quality of Seguchie Creek and Selected Wetlands Tributary to Mille Lacs Lake in Crow Wing County, Minnesota, October 2003 to October 2006

USGS Publications Warehouse

Fallon, James D.; Yaeger, Christine S.

2009-01-01

Mille Lacs Lake and its tributaries, located in east-central Minnesota, are important resources to the public. In addition, many wetlands and lakes that feed Mille Lacs Lake are of high resource quality and vulnerable to degradation. Construction of a new four-lane expansion of U.S. Highway 169 has been planned along the western part of the drainage area of Mille Lacs Lake in Crow Wing County. Concerns exist that the proposed highway could affect the resource quality of surface waters tributary to Mille Lacs Lake. Baseline water- and bed-sediment quality characteristics of surface waters tributary to Mille Lacs Lake were needed prior to the proposed highway construction. The U.S. Geological Survey, in cooperation with the Minnesota Department of Transportation, characterized the water- and bed-sediment quality at selected locations that the proposed route intersects from October 2003 to October 2006. Locations included Seguchie Creek upstream and downstream from the proposed route and three wetlands draining to Mille Lacs Lake. The mean streamflow of Seguchie Creek increased between the two sites: flow at the downstream streamflow-gaging station of 0.22 cubic meter per second was 5.6 percent greater than the mean streamflow at the upstream streamflow-gaging station of 0.21 cubic meter per second. Because of the large amount of storage immediately upstream from both gaging stations, increases in flow were gradual even during intense precipitation. The ranges of most constituent concentrations in water were nearly identical between the two sampling sites on Seguchie Creek. No concentrations exceeded applicable water-quality standards set by the State of Minnesota. Dissolved-oxygen concentrations at the downstream gaging station were less than the daily minimum standard of 4.0 milligrams per liter for 6 of 26 measurements. Constituent loads in Seguchie Creek were greater at the downstream site than the upstream site for all measured, including dissolved chloride (1.7 percent), ammonia plus organic nitrogen (13 percent), total phosphorus (62 percent), and suspended sediment (11 percent) during the study. All constituents had seasonal peaks in spring and fall. The large loads during the fall resulted from unusually large precipitation and streamflow patterns. This caused the two greatest streamflow peaks at both sites to occur during October (2004 and 2005). In Seguchie Creek, bed-sediment concentrations of five metals and trace elements (arsenic, cadmium, chromium, lead, and zinc) exceeded the Interim Sediment Quality Guidelines (ISQG) set by the Canadian Council of Ministers of the Environment. Bed-sediment samples from the upstream site had more exceedances of ISQGs for metals and trace elements than did samples from the downstream site (seven and two exceedances, respectively). Bed-sediment samples from the downstream site had more exceedances of ISQGs (20 exceedances) for semivolatile organic compounds than did samples from the upstream site (8 exceedances), indicating different sources for organic compounds than for metals and trace elements. Concentrations of 11 semivolatile organic compounds exceeded ISQGs: ancenaphthene, acenaphthylene, anthracene, benzo[a]anthracene, benzo[a]pyrene, chrysene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene. In bed-sediment samples collected from three wetlands, concentrations of all six metals exceeded ISQGs: arsenic, cadmium, chromium, copper, lead, and zinc. Concentrations of three semivolatile organic compounds exceeded ISQGs: flouranthene, phenanthrene, and pyrene. Results indicate that areas appearing relatively undisturbed and of high resource value can have degraded quality from previous unknown land use.

Evaluation of the performance of biochars as an adsorbent for polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Jung, J.; Kang, S.; Ok, Y.; Choi, Y.

2016-12-01

Biochars, byproducts generated by pyrolysis of biomass, are known to have several advantages as a soil amendment such as carbon sequestration effect, enhancement of soil microbial activity, and nutrient supply. Because of their high surface area and affinity to organic pollutants, biochars are also being evaluated as an adsorbent for hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) in soils, stormwater, and wastewater. Depending on their organic precursors and pyrolysis temperatures, biochars have been shown to have various physicochemical properties, which should determine their performance as an adsorbent for hydrophobic organic pollutants. In this study, we obtained biochars derived from soybean stover, wood chip, rice husk, and sewage sludge with pyrolysis temperatures of 700°, 250°, 500°, and 500°, respectively, to investigate their performance for PAH adsorption. Adsorption kinetic and isotherm experiments were conducted using naphthalene and phenanthrene as model compounds. Soybean stover biochar reached close to equilibrium in 7 days while the others did in 25 days in the kinetic experiments. The first-order sorption rate constants were greater for naphthalene than for phenanthrene for all biochars studied, and they were generally in the order of soybean stover>rice husk>sewage sludge>wood chip biochars for the two contaminants. The removal rates of aqueous PAHs at equilibrium were in the order of soybean stover>rice husk>sewage sludge>wood chip biochars at a concentration range of a few ng/mL. The results suggested that the sorption capability and the rate is generally greater for biochar produced from plant materials than that from sludge, and for biochar produced at higher pyrolysis temperature. Comparing the sorption properties of the biochars and granular activated carbon (GAC), it is shown that biochar produced at optimal conditions can exhibit performance for PAH adsorption similar to GAC.

Biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the Middle Atlantic Ridge.

PubMed

Cui, Zhisong; Lai, Qiliang; Dong, Chunming; Shao, Zongze

2008-08-01

The bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched with the PAH mixture mentioned above in the lab. The resulting consortia were named C2CO and C2PPN respectively. Their bacterial composition was analysed with plate cultivation, PCR-DGGE and 16S rDNA library analysis. On plates, isolates belonging to Pseudoalteromonas, Halomonas, Marinobacter, Thalassospira and Tistrella dominated the culturable populations. With PCR-DGGE, five major bands closely related to Cycloclasticus, Alteromonas, Thalassospira, Alcanivorax and Rhodospirillaceae were detected in consortium C2CO, while only one major band of Cycloclasticus was detected in consortium C2PPN. In addition, the dynamics of community structure in response to aromatic substrate alterations were examined. As a result, three ribotypes of Cycloclasticus were detected by 16S rDNA library analysis, one which played a key role in phenanthrene degradation; two Alteromonas bacteria dominated the naphthalene reselected consortium. Although bacteria of the two genera grew as the main members of the communities, none of them were isolated, probably owing to their poor cultivability. These results confirm that bacteria of Cycloclasticus are important obligate PAH degraders in marine environments, and coexist with other degrading bacteria that inhabit the deep subsurface sediment of the Atlantic. This supports the view that PAH accumulation and bioattenuation occur in remote areas consistently and continuously.

Biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the Middle Atlantic Ridge

PubMed Central

Cui, Zhisong; Lai, Qiliang; Dong, Chunming; Shao, Zongze

2008-01-01

The bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched with the PAH mixture mentioned above in the lab. The resulting consortia were named C2CO and C2PPN respectively. Their bacterial composition was analysed with plate cultivation, PCR-DGGE and 16S rDNA library analysis. On plates, isolates belonging to Pseudoalteromonas, Halomonas, Marinobacter, Thalassospira and Tistrella dominated the culturable populations. With PCR-DGGE, five major bands closely related to Cycloclasticus, Alteromonas, Thalassospira, Alcanivorax and Rhodospirillaceae were detected in consortium C2CO, while only one major band of Cycloclasticus was detected in consortium C2PPN. In addition, the dynamics of community structure in response to aromatic substrate alterations were examined. As a result, three ribotypes of Cycloclasticus were detected by 16S rDNA library analysis, one which played a key role in phenanthrene degradation; two Alteromonas bacteria dominated the naphthalene reselected consortium. Although bacteria of the two genera grew as the main members of the communities, none of them were isolated, probably owing to their poor cultivability. These results confirm that bacteria of Cycloclasticus are important obligate PAH degraders in marine environments, and coexist with other degrading bacteria that inhabit the deep subsurface sediment of the Atlantic. This supports the view that PAH accumulation and bioattenuation occur in remote areas consistently and continuously. PMID:18445026

High Voltage Electrochemiluminescence (ECL) as a New Method for Detection of PAH During Screening for PAH-Degrading Microbial Consortia.

PubMed

Staninska, Justyna; Szczepaniak, Zuzanna; Staninski, Krzysztof; Czarny, Jakub; Piotrowska-Cyplik, Agnieszka; Nowak, Jacek; Marecik, Roman; Chrzanowski, Łukasz; Cyplik, Paweł

The search for new bacterial consortia capable of removing PAH from the environment is associated with the need to employ novel, simple, and economically efficient detection methods. A fluorimetric method (FL) as well as high voltage electrochemiluminescence (ECL) on a modified surface of an aluminum electrode were used in order to determine the changes in the concentrations of PAH in the studied aqueous solutions. The ECL signal (the spectrum and emission intensity for a given wavelength) was determined with the use of an apparatus operating in single photon counting mode. The dependency of ECL and FL intensity on the concentration of naphthalene, phenanthrene, and pyrene was linear in the studied concentration range. The biodegradation kinetics of the particular PAH compounds was determined on the basis of the obtained spectroscopic determinations. It has been established that the half-life of naphthalene, phenanthrene, and pyrene at initial concentrations of 50 mg/l (beyond the solubility limit) reached 41, 75, and 130 h, accordingly. Additionally, the possibility of using ECL for rapid determination of the soluble fraction of PAH directly in the aqueous medium has been confirmed. Metagenomic analysis of the gene encoding 16S rRNA was conducted on the basis of V4 hypervariable region of the 16S rRNA gene and allowed to identify 198 species of bacteria that create the S4consortium. The consortium was dominated by Gammaproteobacteria (78.82 %), Flavobacteria (9.25 %), Betaproteobacteria (7.68 %), Sphingobacteria (3.76 %), Alphaproteobacteria (0.42 %), Clostridia (0.04 %), and Bacilli (0.03 %).

Which persistent organic pollutants in the rivers of the Bohai Region of China represent the greatest risk to the local ecosystem?

PubMed

Zhang, Yueqing; Johnson, Andrew C; Su, Chao; Zhang, Meng; Jürgens, Monika D; Shi, Yajuan; Lu, Yonglong

2017-07-01

Freshwater aquatic organisms can be exposed to hundreds of persistent organic pollutants (POPs) discharged by natural and anthropogenic activities. Given our limited resources it is necessary to identify, from the existing evidence, which is the greatest threat so that control measures can be targeted wisely. The focus of this study was to rank POPs according to the relative risk they represent for aquatic organisms in rivers in the Bohai Region, China. A list of 14 POPs was compiled based on the available data on their presence in these rivers and ecotoxicological data. Those that were widely detected were benzo[a]pyrene, p,p'-DDE, p,p'-DDT, endrin, fluoranthene, heptachlor, hexabromocyclododecane, hexachlorobenzene, α-hexachlorocyclohexane, γ-hexachlorocyclohexane, naphthalene, perfluorooctanoic acid, perfluorooctane sulfonate and phenanthrene. Effect concentrations were compiled for Chinese relevant and standard test species and compared with river aqueous concentrations. Only bed-sediment concentrations were available so water levels were calculated based on the known local sediment organic carbon concentration and the K oc . The POPs were ranked on the ratio between the median river and median effect concentrations. Of the POPs studied, fluoranthene was ranked as the highest threat, followed by phenanthrene, naphthalene and p,p'-DDE. The risk from p,p'-DDE may be magnified due to being highly bioaccumulative. However, the greatest overlap between river concentrations and effect levels was for lindane. Overall, fish was the most sensitive species group to the risks from POPs. Hotspots with the highest concentrations and hence risk were mainly associated with watercourses draining in Tianjin, the biggest city in the Bohai Region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of the performance of SMFCs in the bioremediation of PAHs in contaminated marine sediments under different redox conditions and analysis of the associated microbial communities.

PubMed

Hamdan, Hamdan Z; Salam, Darine A; Hari, Ananda Rao; Semerjian, Lucy; Saikaly, Pascal

2017-01-01

The biodegradation of naphthalene, 2-methylnaphthalene and phenanthrene was evaluated in marine sediment microbial fuel cells (SMFCs) under different biodegradation conditions, including sulfate reduction as a major biodegradation pathway, employment of anode as terminal electron acceptor (TEA) under inhibited sulfate reducing bacteria activity, and combined sulfate and anode usage as electron acceptors. A significant removal of naphthalene and 2-methylnaphthalene was observed at early stages of incubation in all treatments and was attributed to their high volatility. In the case of phenanthrene, a significant removal (93.83±1.68%) was measured in the closed circuit SMFCs with the anode acting as the main TEA and under combined anode and sulfate reduction conditions (88.51±1.3%). A much lower removal (40.37±3.24%) was achieved in the open circuit SMFCs operating with sulfate reduction as a major biodegradation pathway. Analysis of the anodic bacterial community using 16S rRNA gene pyrosequencing revealed the enrichment of genera with potential exoelectrogenic capability, namely Geoalkalibacter and Desulfuromonas, on the anode of the closed circuit SMFCs under inhibited SRB activity, while they were not detected on the anode of open circuit SMFCs. These results demonstrate the role of the anode in enhancing PAHs biodegradation in contaminated marine sediments and suggest a higher system efficiency in the absence of competition between microbial redox processes (under SRB inhibition), namely due to the anode enrichment with exoelectrogenic bacteria, which is a more energetically favorable mechanism for PAHs oxidation than sulfate. Copyright © 2016. Published by Elsevier B.V.

Time-dependent density functional theory description of total photoabsorption cross sections

NASA Astrophysics Data System (ADS)

Tenorio, Bruno Nunes Cabral; Nascimento, Marco Antonio Chaer; Rocha, Alexandre Braga

2018-02-01

The time-dependent version of the density functional theory (TDDFT) has been used to calculate the total photoabsorption cross section of a number of molecules, namely, benzene, pyridine, furan, pyrrole, thiophene, phenol, naphthalene, and anthracene. The discrete electronic pseudo-spectra, obtained in a L2 basis set calculation were used in an analytic continuation procedure to obtain the photoabsorption cross sections. The ammonia molecule was chosen as a model system to compare the results obtained with TDDFT to those obtained with the linear response coupled cluster approach in order to make a link with our previous work and establish benchmarks.

Electrochemistry and Spectroelectrochemistry of 1,8-Naphthalene and 1,8- Anthracene-Linked Cofacial Binuclear Metallophthalocynanines. New Mixed Valence Metallopthalocyanines

DTIC Science & Technology

1990-05-10

slope of a plot of peak current vs. sweep rate to the charge should be equal to nF/4RT, where n is the number of electrons per adsorbed species and...overlapping waves. b) Values ofAEp : (Ep. - Epe) are given at a potential sweep rate of 50 mV/s. c) data fom ref.8g. d) Potentials are approximate because...cyclic voltametry at 200, 100, 50 and 20 mV/s, Average data being E : (Eps + Epc)/2 are reported. Data in parenthesis are estimated from overlapping

Genetic analysis of biodegradation of tetralin by a Sphingomonas strain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernaez, M.J.; Santero, E.; Reineke, W.

Tetralin (1,2,3,4-tetrahydronaphthalene) is produced for industrial purposes from naphthalene by catalytic hydrogenation or from anthracene by cracking. A strain designated TFA which very efficiently utilizes tetralin has been isolated from the Rhine river. The strain has been identified as Sphingomonas macrogoltabidus, based on 16S rDNA sequence similarity. Genetic analysis of tetralin biodegradation has been performed by insertion mutagenesis and by physical analysis and analysis of complementation between the mutants. The genes involved in tetralin utilization are clustered in a region of 9 kb, comprising at least five genes grouped in two divergently transcribed operons.

Continuous catalytic hydrogenation of polyaromatic hydrocarbon compounds in hydrogen-supercritical carbon dioxide.

PubMed

Yuan, Tao; Fournier, Anick R; Proudlock, Raymond; Marshall, William D

2007-03-15

A continuous hydrogenation device was evaluated for the detoxification of selected tri-, tetra-, or pentacyclic polyaromatic hydrocarbon (PAH) compounds {anthracene, phenanthrene, chrysene, and benzo[a]pyrene (B[a]P)} by hydrogenation. A substrate stream in hexane, 0.05-1.0% (w/v), was mixed with hydrogen-carbon dioxide (H2-CO2, 5-30% v/v) and delivered to a heated reactor column (25 cm x 1 cm) containing palladium supported on gamma alumina (Pd0/gamma-Al2O3) that was terminated with a capillary restrictor. The flow rate from the reactor, approximately 800 mL min(-1) decompressed gas, corresponded to 4 mL min(-1) fluid under the operating conditions of the trials. Reaction products were recovered by passing the reactor effluent through hexane. At 90 degrees C, the anthracene or phenanthrene substrate was hydrogenated only partially to octahydro and dodecahydro species and contained only a minor quantity of totally hydrogenated products. For substrates with increasing numbers of fused aromatic rings, the hydrogenation efficiency was decreased further. However, at an increasing temperature (90-150 degrees C) and increasing mobile phase flow rate (20.68 MPa corresponding to 2100 mL min(-1) decompressed gas), B[a]P and chrysene were hydrogenated, virtuallytotally, to their corresponding perhydro analogues (eicosahydrobenzo[a]pyrenes and octadecahydrochrysenes), respectively. That this approach might be useful for decontaminating soil extracts was supported by companion in vitro trials in which the substrate and products were assayed for mutagenic activity with five bacterial strains that are auxotrophic for histidine (Salmonella typhimurium TA98, TA100, TA1535, and TA1537) or tryptophan (Escherichia coliWP2 uvrA), using the bacterial reverse mutation assay (modified Ames test). Generally, substantial increases in revertant colony counts were not observed with any of the strains following exposure to the hydrogenation products in the absence or presence of the 10 or 30% S9 mix, which is consistent with the loss of mutagenic activity from these hydrogenation products.

The Mid-Infrared Absorption Spectra of Neutral PAHs in Dense Interstellar Clouds

NASA Technical Reports Server (NTRS)

Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) are common throughout the universe and are expected to be present in dense interstellar clouds. In these environments, some P.4Hs may be present in the gas phase, but most should be frozen into ice mantles or adsorbed onto dust grains and their spectral features are expected to be seen in absorption. Here we extend our previous work on the infrared spectral properties of the small PAH naphthalene (C10H8) in several media to include the full mid-infrared laboratory spectra of 11 other PAHs and related aromatic species frozen in H2O ices. These include the molecules 1,2-dihydronaphthalene, anthracene, 9,1O-dihydroanthracene, phenanthrene, pyrene, benzo[e]pyrene, perylene, benzo(k)fluoranthene, pentacene, benzo[ghi]perylene, and coronene. These results demonstrate that PAHs and related molecules, as a class, show the same spectral behaviors as naphthalene when incorporated into H2O-rich matrices. When compared to the spectra of these same molecules isolated in inert matrices (e.g., Ar or N2), the absorption bands produced when they are frozen in H2O matrices are broader (factors of 3-10), show small position shifts in either direction (usually < 4/cm, always < 10/cm), and show variable changes in relative band strengths (typically factors of 1-3). There is no evidence of systematic increases or decreases in the absolute strengths of the bands of these molecules when they are incorporated in H2O matrices. In H2O-rich ices, their absorption bands are relatively insensitive to concentration over the range of 10 < H2O/PAH < 200): The absorption bands of these molecules are also insensitive to temperature over the 10 K < T < 125 K range, although the spectra can show dramatic changes as the ices are warmed through the temperature range in which amorphous H2O ice converts to its cubic and hexagonal crystalline forms (T > 125 Kj. Given the small observed band shifts cause by H2O, the current database of spectra from Ar matrix-isolated neutral PAHs and related molecules should be useful for the search for these species in dense clouds on the basis of observed absorption band positions. Furthermore, these data permit determination of column densities to better than a factor of 3 for PAHs in dense clouds. Column density determination of detected aromatics to better than a factor of 3 will, however, require good knowledge about the nature of the matrix in which the PAH is embedded and laboratory studies of relevant samples.

Systematic developmental neurotoxicity assessment of a representative PAH Superfund mixture using zebrafish

DOE PAGES

Geier, Mitra C.; James Minick, D.; Truong, Lisa; ...

2018-04-01

Superfund sites often consist of complex mixtures of polycyclic aromatic hydrocarbons (PAHs). It is widely recognized that PAHs pose risks to human and environmental health, but the risks posed by exposure to PAH mixtures are unclear. Here, we constructed an environmentally relevant PAH mixture with the top 10 most prevalent PAHs (SM10) from a Superfund site derived from environmental passive sampling data. Using the zebrafish model, we measured body burden at 48 hours post fertilization (hpf) and evaluated the developmental and neurotoxicity of SM10 and the 10 individual constituents at 24 hours post fertilization (hpf) and 5 days post fertilizationmore » (dpf). Zebrafish embryos were exposed from 6 to 120 hpf to (1) the SM10 mixture, (2) a variety of individual PAHs: pyrene, fluoranthene, retene, benzo[a]anthracene, chrysene, naphthalene, acenaphthene, phenanthrene, fluorene, and 2-methylnaphthalene. We demonstrated that SM10 and only 3 of the individual PAHs were developmentally toxic. Subsequently, we constructed and exposed developing zebrafish to two sub-mixtures: SM3 (comprised of 3 of the developmentally toxicity PAHs) and SM7 (7 non-developmentally toxic PAHs). We found that the SM3 toxicity profile was similar to SM10, and SM7 unexpectedly elicited developmental toxicity unlike that seen with its individual components. The results demonstrated that the overall developmental toxicity in the mixtures could be explained using the general concentration addition model. To determine if exposures activated the AHR pathway, spatial expression of CYP1A was evaluated in the 10 individual PAHs and the 3 mixtures at 5 dpf. Results showed activation of AHR in the liver and vasculature for the mixtures and some individual PAHs. Embryos exposed to SM10 during development and raised in chemical-free water into adulthood exhibited decreased learning and responses to startle stimulus indicating that developmental SM10 exposures affect neurobehavior. Collectively, these results exemplify the utility of zebrafish to investigate the developmental and neurotoxicity of complex mixtures.« less

Systematic developmental neurotoxicity assessment of a representative PAH Superfund mixture using zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geier, Mitra C.; James Minick, D.; Truong, Lisa

Superfund sites often consist of complex mixtures of polycyclic aromatic hydrocarbons (PAHs). It is widely recognized that PAHs pose risks to human and environmental health, but the risks posed by exposure to PAH mixtures are unclear. Here, we constructed an environmentally relevant PAH mixture with the top 10 most prevalent PAHs (SM10) from a Superfund site derived from environmental passive sampling data. Using the zebrafish model, we measured body burden at 48 hours post fertilization (hpf) and evaluated the developmental and neurotoxicity of SM10 and the 10 individual constituents at 24 hours post fertilization (hpf) and 5 days post fertilizationmore » (dpf). Zebrafish embryos were exposed from 6 to 120 hpf to (1) the SM10 mixture, (2) a variety of individual PAHs: pyrene, fluoranthene, retene, benzo[a]anthracene, chrysene, naphthalene, acenaphthene, phenanthrene, fluorene, and 2-methylnaphthalene. We demonstrated that SM10 and only 3 of the individual PAHs were developmentally toxic. Subsequently, we constructed and exposed developing zebrafish to two sub-mixtures: SM3 (comprised of 3 of the developmentally toxicity PAHs) and SM7 (7 non-developmentally toxic PAHs). We found that the SM3 toxicity profile was similar to SM10, and SM7 unexpectedly elicited developmental toxicity unlike that seen with its individual components. The results demonstrated that the overall developmental toxicity in the mixtures could be explained using the general concentration addition model. To determine if exposures activated the AHR pathway, spatial expression of CYP1A was evaluated in the 10 individual PAHs and the 3 mixtures at 5 dpf. Results showed activation of AHR in the liver and vasculature for the mixtures and some individual PAHs. Embryos exposed to SM10 during development and raised in chemical-free water into adulthood exhibited decreased learning and responses to startle stimulus indicating that developmental SM10 exposures affect neurobehavior. Collectively, these results exemplify the utility of zebrafish to investigate the developmental and neurotoxicity of complex mixtures.« less

The 1:1 co-crystal of 2-bromo-naphthalene-1,4-dione and 1,8-di-hydroxy-anthracene-9,10-dione: crystal structure and Hirshfeld surface analysis.

PubMed

Tonin, Marlon D L; Garden, Simon J; Jotani, Mukesh M; Wardell, Solange M S V; Wardell, James L; Tiekink, Edward R T

2017-05-01

The asymmetric unit of the title co-crystal, C 10 H 5 BrO 2 ·C 14 H 8 O 4 [systematic name: 2-bromo-1,4-di-hydro-naphthalene-1,4-dione-1,8-dihy-droxy-9,10-di-hydro-anthracene-9,10-dione (1/1)], features one mol-ecule of each coformer. The 2-bromo-naphtho-quinone mol-ecule is almost planar [r.m.s deviation of the 13 non-H atoms = 0.060 Å, with the maximum deviations of 0.093 (1) and 0.099 (1) Å being for the Br atom and a carbonyl-O atom, respectively]. The 1,8-di-hydroxy-anthra-quinone mol-ecule is planar (r.m.s. deviation for the 18 non-H atoms is 0.022 Å) and features two intra-molecular hy-droxy-O-H⋯O(carbon-yl) hydrogen bonds. Dimeric aggregates of 1,8-di-hydroxy-anthra-quinone mol-ecules assemble through weak inter-molecular hy-droxy-O-H⋯O(carbon-yl) hydrogen bonds. The mol-ecular packing comprises stacks of mol-ecules of 2-bromo-naphtho-quinone and dimeric assembles of 1,8-di-hydroxy-anthra-quinone with the shortest π-π contact within a stack of 3.5760 (9) Å occurring between the different rings of 2-bromo-naphtho-quinone mol-ecules. The analysis of the Hirshfeld surface reveals the importance of the inter-actions just indicated but, also the contribution of additional C-H⋯O contacts as well as C=O⋯π inter-actions to the mol-ecular packing.

Effect of ZSM-5 acidity on aromatic product selectivity during upgrading of pine pyrolysis vapors

DOE PAGES

Engtrakul, Chaiwat; Mukarakate, Calvin; Starace, Anne K.; ...

2015-11-14

The impact of catalyst acidity on the selectivity of upgraded biomass pyrolysis products was studied by passing pine pyrolysis vapors over five ZSM-5 catalysts of varying acidity at 500 degrees C. The SiO 2-to-Al 2O 3 ratio (SAR) of the ZSM-5 zeolite was varied from 23 to 280 to control the acidity of the catalyst and the composition of upgraded products. The upgraded product stream was analyzed by GCMS. Additionally, catalysts were characterized using temperature programmed desorption, diffuse-reflectance FTIR spectroscopy, N 2 physisorption, and X-ray diffraction. The results showed that the biomass pyrolysis vapors were highly deoxygenated to form amore » slate of aromatic hydrocarbons over all of the tested ZSM-5 catalysts. As the overall acidity of the ZSM-5 increased the selectivity toward alkylated (substituted) aromatics (e.g., xylene, dimethyl-naphthalene, and methyl-anthracene) decreased while the selectivity toward unsubstituted aromatics (e.g., benzene, naphthalene, and anthracene) increased. Additionally, the selectivity toward polycyclic aromatic compounds (2-ring and 3-ring) increased as catalyst acidity increased, corresponding to a decrease in acid site spacing. The increased selectivity toward less substituted polycyclic aromatic compounds with increasing acidity is related to the relative rates of cyclization and alkylation reactions within the zeolite structure. As the acid site concentration increases and sites become closer to each other, the formation of additional cyclization products occurs at a greater rate than alkylated products. The ability to adjust product selectivity within 1-, 2-, and 3-ring aromatic families, as well as the degree of substitution, by varying ZSM-5 acidity could have significant benefits in terms creating a slate of upgraded biomass pyrolysis products to meet specific target market demands.« less

PAH composition of Water Based Drilling Mud and drill cuttings in the offshore region, east coast of India.

PubMed

Jagwani, Devaanshi; Kulkarni, Atul; Shukla, Parth; Ramteke, Dilip S; Juneja, Harjeet D

2011-11-01

As a consequence of offshore drilling, used Water Based Drilling Muds (WBMs) are typically disposed off, by discharging into the sea; such a disposal does not fully eliminate the environmental hazards. Hence, in this study, 2, 3, 4 and 5 ringed polycyclic aromatic hydrocarbons (PAHs i.e. naphthalene, fluorene, phenanthrene, fluoranthene, chrysene and benzo (a) pyrene) were determined from the WBMs and associated drill cuttings obtained from varying depths(viz. 150, 300 and 600 m) from three offshore wells present in East coast of India. In both WBMs and drill cuttings, concentration of naphthalene was maximum i.e. 81.59 ± 2.73 and 39.87 ± 2.40 mg/kg respectively, while benzo (a) pyrene was minimum i.e. 0.19 ± 0.07 and 0.12 ± 0.03 mg/kg respectively. The WBMs contained significantly (p < 0.05) higher PAH concentration than drill cuttings. The individual PAH concentration significantly (p < 0.01) increased with increasing depth in each well.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, E.; Kraatz, M.; Luthy, R.G.

The dissolution of naphthalene, phenanthrene, and pyrene from viscous organic phases into water was studied in continuous-flow systems for time periods ranging from several months to more than 1 year. By selecting nonaqueous phases ranging from low viscosity to semisolid, i.e., from a light lubricating oil to paraffin, the governance of mass transfer was shown to vary from water phase control to nonaqueous phase control. An advancing depleted-zone model is proposed to explain the dissolution of PAHs from a viscous organic phase wherein the formation of a depleted zone within the organic phase increases the organic phase resistance to themore » dissolution of PAHs. The experimental data suggest the formation of a depleted zone within the organic phase for systems comprising a high-viscosity oil, petrolatum (petroleum jelly), and paraffin. Organic phase resistance to naphthalene dissolution became dominant over aqueous phase resistance after flushing for several days. Such effects were not evident for low viscosity lubricating oil. The transition from aqueous-phase dissolution control to nonaqueous-phase dissolution control appears predictable, and this provides a more rational framework to assess long-term release of HOCs from viscous nonaqueous phase liquids and semisolids.« less

Application of solid-phase microextraction method to determine bioavailable fraction of PAH in hazardous waste.

PubMed

Jefimova, J; Irha, N; Mägi, R; Kirso, U

2012-10-01

The solid-phase microextraction (SPME) method was developed to determine PAH free dissolved concentration (C(free)) in field leachates from hazardous waste disposal. SPME technique, involving a 100-μm polydimethylsiloxane (PDMS) fiber coupled to GC-MS was optimized for determination of C(free). The following PAH were found in bioavailable form: acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, with C(free) varying between 2.38 and 62.35 ng/L. Conventional solvent extraction was used for measurement of total concentration (C(total)) in the same samples, and ranging from 1.26 to 77.56 μg/L. Determining C(free) of the hydrophobic toxic pollutants could give useful information for risk assessment of the hazardous waste.

Photolysis of polycyclic aromatic hydrocarbons (PAHs) on Fe3+-montmorillonite surface under visible light: Degradation kinetics, mechanism, and toxicity assessments.

PubMed

Zhao, Song; Jia, Hanzhong; Nulaji, Gulimire; Gao, Hongwei; Wang, Fu; Wang, Chuanyi

2017-10-01

Photochemical behavior of various polycyclic aromatic hydrocarbons (PAHs) on Fe 3+ -modified montmorillonite was explored to determine their potential kinetics, pathways, and mechanism under visible light. Depending on the type of PAH molecules, the transformation rate follows the order of benzo[a]pyrene ≈ anthracene > benzo[a]anthracene > phenanthrene. Quantum simulation results confirm the crucial role of "cation-π" interaction between Fe 3+ and PAHs on their transformation kinetics. Primary intermediates, including quinones, ring-opening products and benzene derivatives, were identified by gas chromatography-mass spectrometer (GC-MS), and the possible photodegradation pathway of benzo[a]pyrene was proposed. Meanwhile, radical intermediates, such as reactive oxygen species (ROS) and free organic radicals, were detected by electron paramagnetic resonance (EPR) technique. The photolysis of selected PAHs, such as anthracene and benzo[a]pyrene, on clay surface firstly occurs by electron transfer from PAHs to Fe 3+ -montmorillonite, followed by degradation involving photo-induced ROS such as ·OH and ·O 2 - . To investigate the acute toxicity of photolysis products, the Microtox ® toxicity test was performed during the photodegradation processes of various PAHs. As a result, the photo-irradiation initially induces increased toxicity by generating reactive intermediates, such as free organic radicals, and then the toxicity gradually decreases with increasing of reaction time. Overall, the present study provides useful information to understand the fate and photo-transformation of PAHs in contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of polycyclic aromatic hydrocarbons using desorption atmospheric pressure chemical ionization coupled to a portable mass spectrometer.

PubMed

Jjunju, Fred P M; Maher, Simon; Li, Anyin; Badu-Tawiah, Abraham K; Taylor, Stephen; Cooks, R Graham

2015-02-01

Desorption atmospheric pressure chemical ionization (DAPCI) is implemented on a portable mass spectrometer and applied to the direct detection of polycyclic aromatic hydrocarbons (PAHs) and alkyl substituted benzenes. The presence of these compounds in the environment poses a significant threat to the health of both humans and wildlife because of their carcinogenic, toxic, and mutagenic properties. As such, instant detection outside of the laboratory is of particular importance to allow in-situ measurement at the source. Using a rapid, high throughput, miniature, handheld mass spectrometer, several alkyl substituted benzenes and PAHs (i.e., 1,2,3,5-tetramethylbenzene, pentamethylbenzene, hexamethylbenzene, fluoranthene, anthracene, benzo[k]fluoranthene, dibenz[a,h]anthracene, acenaphthene, indeno[1,2,3-c,d]pyrene, 9-ethylfluorene, and 1-benzyl-3-methyl-naphthalene) were identified and characterized using tandem mass spectrometry (MS/MS) from ambient surfaces, in the open air. This method can provide almost instantaneous information while minimizing sample preparation, which is advantageous in terms of both cost and simplicity of analysis. This MS-based technique is applicable to a wide range of environmental organic molecules.

Association of atmospheric concentrations of polycyclic aromatic hydrocarbons with their urinary metabolites in children and adolescents.

PubMed

Poursafa, Parinaz; Amin, Mohammad Mehdi; Hajizadeh, Yaghoub; Mansourian, Marjan; Pourzamani, Hamidreza; Ebrahim, Karim; Sadeghian, Babak; Kelishadi, Roya

2017-07-01

This study aims to determine the atmospheric concentrations of particulate matter 2.5 (PM 2.5 )-bounded polycyclic aromatic hydrocarbons (PAHs) and their association with their urinary metabolites in children and adolescents. This study was conducted from October 2014 to March 2016 in Isfahan, Iran. We measured 16 species of PAHs bounded to PM 2.5 by gas chromatography mass spectrometry (GC/MS) from 7 parts of the city. Moreover, PAH urinary metabolites were measured in 186 children and adolescents, randomly selected from households. Urinary metabolites consisted of 1-hydroxy naphthalene (1-naphthol), 2-hydroxy naphthalene (2-naphthol), 9-hydroxy phenanthrene (9-phenanthrol), and 1-hydroxy pyrene using GC/MS. Considering the short half-lives of PAHs, we measured the metabolites twice with 4 to 6 months of time interval. We found that the ambient concentrations of PAHs were significantly associated with their urinary metabolites. 1-hydroxy naphthalene and 2-hydroxy naphthalene concentrations showed an increase of 1.049 (95% CI: 1.030, 1.069) and 1.047 (95% CI: 1.025, 1.066) for each unit increase (1 ng/m 3 ) in ambient naphthalene. Similarly, 1-hydroxy pyrene showed an increase of 1.009 (95% CI: 1.006-1.011) for each unit increase (1 ng/m 3 ) in ambient pyrene concentration after adjustment for body mass index, physical activity level, urinary creatinine, age, and sex. The association of urinary 9-hydroxyphenanthrene and ambient phenantherene was significant in the crude model; however after adjustment for the abovementioned covariates, it was no more significant. We found significant correlations between exposure to ambient PM 2.5 -bounded PAHs and their urinary excretion. Considering the adverse health effects of PAHs in the pediatric age group, biomonitoring of PAHs should be underscored; preventive measures need to be intensified.

Carrier-doped aromatic hydrocarbons: a new platform in condensed matter chemistry and physics.

PubMed

Heguri, Satoshi; Tanigaki, Katsumi

2018-02-27

High-quality bulk samples of the first four polyacenes, which are naphthalene, anthracene, tetracene, and pentacene, doped with alkali metal in 1 : 1 and 1 : 2 stoichiometries were prepared and their fundamental properties were systematically studied. A new systematic understanding on the electronic states of electron-doped polyacenes sensitive to the energetic balance among on-site Coulomb repulsion, bandwidth and the Peierls instability was provided. The carrier-doped typical aromatic hydrocarbons showed a large variety of properties as well as charge transfer complexes and metal-doped fullerides. We open a new avenue for organometallic and inorganic chemistry.

Peroxidases from root exudates of Medicago sativa and Sorghum bicolor: Catalytic properties and involvement in PAH degradation.

PubMed

Dubrovskaya, Ekaterina; Pozdnyakova, Natalia; Golubev, Sergey; Muratova, Anna; Grinev, Vyacheslav; Bondarenkova, Anastasiya; Turkovskaya, Olga

2017-02-01

Peroxidases from root exudates of sorghum (Sorghum bicolor L. Moench) and alfalfa (Medicago sativa L.) were purified and characterized, and their ability to oxidize native PAHs and PAH-derivatives was evaluated. The obtained data confirm that peroxidases are involved in the rhizosphere degradation of PAHs. Nondenaturing PAGE showed that the peroxidases of both plants were represented by a range of isoforms/isoenzymes (five to eight). Minor forms were lost during further purification, and as a result, the major anionic form from alfalfa root exudates and the major cationic form from those of sorghum were obtained. Both electrophoretically homogeneous peroxidases were monomeric proteins with a molecular weight of about 46-48 kDa. The pH optima and the main catalytic constants for the test substrates were determined. On the basis of their molecular and catalytic properties, the obtained enzymes were found to be typical plant peroxidases. Derivatives of PAHs and potential products of their microbial degradation (9-phenanthrol and 9,10-phenanthrenequinone), unlike the parent PAH (phenanthrene), inhibited the catalytic activity of the peroxidases, possibly indicating greater availability of the enzymes' active centers to these substances. Peroxidase-catalyzed decreases in the concentrations of a number of PAHs and their derivatives were observed. Sorghum peroxidase oxidized anthracene and phenanthrene, while alfalfa peroxidase oxidized only phenanthrene. 1-Hydroxy-2-naphthoic acid was best oxidized by peroxidase of alfalfa. However, quinone derivatives of PAHs were unavailable to sorghum peroxidase, but were oxidized by alfalfa peroxidase. These results indicate that the major peroxidases from root exudates of alfalfa and sorghum can have a role in the rhizosphere degradation of PAHs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Versatile peroxidase of Bjerkandera fumosa: substrate and inhibitor specificity.

PubMed

Pozdnyakova, Natalia; Makarov, Oleg; Chernyshova, Marina; Turkovskaya, Olga; Jarosz-Wilkolazka, Anna

2013-01-10

The inhibitor and substrate specificities of versatile peroxidase from Bjerkandera fumosa (VPBF) were studied. Two different effects were found: NaN(3), Tween-80, anthracene, and fluorene decreased the activity of VPBF, but p-aminobenzoic acid increased it. A mixed mechanism of effector influence on the activity of this enzyme was shown. The catalytic properties of VPBF in the oxidation of mono- and polycyclic aromatic compounds were studied also. 2,7-Diaminofluorene, ABTS, veratryl alcohol, and syringaldazine can be oxidized by VPBF in two ways: either directly by the enzyme or by diffusible chelated Mn(3+) as an oxidizing agent. During VPBF oxidation of 2,7-diaminofluorene, both with and without Mn(2+), biphasic kinetics with apparent saturation in both micromolar and millimolar ranges were obtained. In the case of ABTS, inhibition of VPBF activity by an excess of substrate was observed. Direct oxidation of p-aminobenzoic acid by versatile peroxidase was found for the first time. The oxidation of three- and four-ring PAHs by VPBF was investigated, and the oxidation of anthracene, phenanthrene, fluorene, pyrene, chrysene, and fluoranthene was shown. The products of PAH oxidation (9,10-anthraquinone, 9,10-phenanthrenequinone, and 9-fluorenone) catalyzed by VPBF were identified. Copyright © 2012 Elsevier Inc. All rights reserved.

Key high molecular weight PAH-degrading bacteria in a soil consortium enriched using a sand-in-liquid microcosm system.

PubMed

Tauler, Margalida; Vila, Joaquim; Nieto, José María; Grifoll, Magdalena

2016-04-01

A novel biphasic system containing mineral medium and sand coated with a biologically weathered creosote-PAH mixture was developed to specifically enrich the high molecular weight polycyclic aromatic hydrocarbon (HMW PAH)-degrading community from a creosote-polluted soil. This consortium (UBHP) removed 70% of the total HMW PAHs and their alkyl-derivatives in 12 weeks. Based on a combined culture-dependent/independent approach, including clone library analysis, detection of catabolic genes, metabolomic profiles, and characterization of bacterial isolates, 10 phylotypes corresponding to five major genera (Sphingobium, Sphingomonas, Achromobacter, Pseudomonas, and Mycobacterium) were pointed out as key players within the community. In response to exposure to different single PAHs, members of sphingomonads were associated to the utilization of phenanthrene, fluoranthene, benzo[a]anthracene, and chrysene, while the degradation of pyrene was mainly associated to low-abundance mycobacteria. In addition to them, a number of uncultured phylotypes were detected, being of special relevance a group of Gammaproteobacteria closely related to a group previously associated with pyrene degradation that were here related to benzo(a)anthracene degradation. The overall environmental relevance of these phylotypes was confirmed by pyrosequencing analysis of the microbial community shift in the creosote-polluted soil during a lab-scale biostimulation.

Formation of Carbon Nanotube Based Gears: Quantum Chemistry and Molecular Mechanics Study of the Electrophilic Addition of o-Benzyne to Fullerenes, Graphene, and Nanotubes

NASA Technical Reports Server (NTRS)

Jaffe, Richard; Han, Jie; Globus, Al; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

Considerable progress has been made in recent years in chemical functionalization of fullerene molecules. In some cases, the predominant reaction products are different from those obtained (using the same reactants) from polycyclic aromatic hydrocarbons (PAHs). One such example is the cycloaddition of o-benzyne to C60. It is well established that benzyne adds across one of the rings in naphthalene, anthracene and other PAHs forming the [2+4] cycloaddition product (benzobicyclo[2.2.2.]-octatriene with naphthalene and triptycene with anthracene). However, Hoke et al demonstrated that the only reaction path for o-benzyne with C60 leads to the [2+2] cycloaddition product in which benzyne adds across one of the interpentagonal bonds (forming a cyclobutene ring in the process). Either reaction product results in a loss of aromaticity and distortion of the PAH or fullerene substrate, and in a loss of strain in the benzyne. It is not clear, however, why different products are preferred in these cases. In the current paper, we consider the stability of benzyne-nanotube adducts and the ability of Brenner's potential energy model to describe the structure and stability of these adducts. The Brenner potential has been widely used for describing diamondoid and graphitic carbon. Recently it has also been used for molecular mechanics and molecular dynamics simulations of fullerenes and nanotubes. However, it has not been tested for the case of functionalized fullerenes (especially with highly strained geometries). We use the Brenner potential for our companion nanogear simulations and believe that it should be calibrated to insure that those simulations are physically reasonable. In the present work, Density Functional theory (DFT) calculations are used to determine the preferred geometric structures and energetics for this calibration. The DFT method is a kind of ab initio quantum chemistry method for determining the electronic structure of molecules. For a given basis set expansion, it is comparable in accuracy to the MP2 method (better than Hartree Fock, but less accurate than more extensive electron correlation methods such as MP4 or CCSD). However, for systems with large numbers of basis functions it more efficient than any other methods that include electron correlation effects. In this presentation we show the results of DFT calculations for the reaction of benzyne with naphthalene, C60, and nanotube models. We compare energies for [2+2] and [2+4] cycloaddition products. The preferred products for the naphthalene and C60 reactions have been determined by experiment and, thus, these cases serve as a validation of our quantum chemical approach. We also compare the DFT and Brenner potential results. Finally we can predict the likelihood of reaction between benzyne and nanotubes.

Selective removal of organic contaminants from sediments: A methodology for toxicity identification evaluations (TIEs)

USGS Publications Warehouse

Lebo, J.A.; Huckins, J.N.; Petty, J.D.; Ho, K.T.; Stern, E.A.

2000-01-01

Aqueous slurries of a test sediment spiked with dibenz[a,h]anthracene, 2,4,5,2′,4′,5′-hexachlorobiphenyl, p,p′-DDE, or phenanthrene were subjected to decontamination experimentation. The spiked sediments were agitated at elevated temperatures for at least 96 h in the presence of either of the two contaminant-absorbing media: clusters of polyethylene membrane or lipid-containing semipermeable membrane devices (SPMDs). The effects of treatment temperature and surface area of media on the removal of contaminants were explored. This work is part of a larger methodology for whole-sediment toxicity identification evaluation (TIE). A method is being sought that is capable of detoxifying sediments with respect to organic contaminants while leaving toxicity attributable to inorganic contaminants unaffected.

Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents.

PubMed

Xi, Zemin; Chen, Baoliang

2014-04-01

Removal of polycyclic aromatic hydrocarbons (PAHs), e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorption kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains (i.e., exposed aromatic core). By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorption coefficients (Kd) were negatively correlated with the polarity index [(O+N)/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Modelling directional solidification

NASA Technical Reports Server (NTRS)

Wilcox, William R.

1987-01-01

An improved understanding of the phenomena of importance to directional solidification is attempted to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Emphasis is now on experimentally determining the influence of convection and freezing rate fluctuations on compositional homogeneity and crystalline perfection. A correlation is sought between heater temperature profiles, buoyancy-driven convection, and doping inhomogeneities using naphthalene doped with anthracene. The influence of spin-up/spin-down is determined on compositional homogeneity and microstructure of indium gallium antimonide. The effect is determined of imposed melting - freezing cycles on indium gallium antimonide. The mechanism behind the increase of grain size caused by using spin-up/spin-down in directional solidification of mercury cadimum telluride is sought.

Sources of sedimentary PAHs in tropical Asian waters: differentiation between pyrogenic and petrogenic sources by alkyl homolog abundance.

PubMed

Saha, Mahua; Togo, Ayako; Mizukawa, Kaoruko; Murakami, Michio; Takada, Hideshige; Zakaria, Mohamad P; Chiem, Nguyen H; Tuyen, Bui Cach; Prudente, Maricar; Boonyatumanond, Ruchaya; Sarkar, Santosh Kumar; Bhattacharya, Badal; Mishra, Pravakar; Tana, Touch Seang

2009-02-01

We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (Sigma PAHs: approximately 1000 to approximately 100,000 ng/g-dry) than in rural areas ( approximately 10 to approximately 100g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes+methylfluoranthenes to pyrene+fluoranthene (MPy/Py), and methylchrysenes+methylbenz[a]anthracenes to chrysene+benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P=0.4, MPy/Py=0.5, and MC/C=1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P approximately 0.5, MPy/Py approximately 0.1, and MC/C approximately 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P approximately 1-4, MPy/Py approximately 0.3-1, and MC/C approximately 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters.

Pyopneumothorax following suicidal kerosene ingestion.

PubMed

Verma, S K; Kapoor, Neha; Bhaskar, Ravi; Upadhyay, Rashmi

2012-12-18

Liquid hydrocarbons derived from petroleum are widely used in household and industry. Many hydrocarbons in kerosene, such as hexane, naphthalene, octane and phenanthrene, are toxic to humans. Pulmonary toxicity is the major cause of morbidity and mortality followed by central nervous-system and cardiovascular complications. As kerosene is a mixture of chemicals, there is no definitive absorption, distribution, metabolism and excretion. The major route of exposure is by inhalation of liquid (aspiration). Kerosene vapours may be mildly irritating to the respiratory system and spray applications of kerosene may provoke signs of pulmonary irritation such as coughing and dyspnoea. Kerosene aspiration leads to inflammation and loss of surfactant. Secondary effects in the lungs include pneumothorax, pneumatocele or bronchopleural fistula. Here, we are presenting a case of pyopneumothorax after kerosene consumption.

Bacterial Degradation of Aromatic Compounds

PubMed Central

Seo, Jong-Su; Keum, Young-Soo; Li, Qing X.

2009-01-01

Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms. PMID:19440284

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 compounds, which are present primarily in the particulate phase in the atmosphere, tended to be in higher concentrations in the surface soils. The apparent effect of the PAH phase in the atmosphere on the concentration of a PAH in ambient surface soils indicates that atmospheric settling of particulate matter is an important source of the PAH compounds in ambient surface soils in Chicago. The distribution of PAH compounds within the city was complex. Comparatively high concentrations were detected near Lake Michigan in the northern part of the city, in much of the western part of the city, and in isolated areas in the southern part of the city. Concentrations were lower in much of the northwestern, south-central, southwestern, and far southern parts of the city. The arithmetic mean concentration of arsenic, mercury, calcium, magnesium, phosphorus, copper, molybdenum, zinc, and selenium was from 2 to 6 times higher in ambient surface soils in the city of Chicago than in soils from surrounding agricultural areas. The arithmetic mean concentration of lead in Chicago soils was about 20 times higher. Concentrations of calcium and magnesium above those of surrounding agricultural areas appear to be related to the effects of dolomite bedrock on the chemical composition of the soil. Elevated concentrations of the remaining elements listed above indicate a potential anthropogenic source(s) of these elements in Chicago soils.

Microcosm studies of subsurface PAH-degrading bacteria from a former manufactured gas plant

NASA Astrophysics Data System (ADS)

Durant, Neal D.; Wilson, Liza P.; Bouwer, Edward J.

1995-01-01

A study was conducted to evaluate the potential for natural in situ biodegradation of polycyclic aromatic hydrocarbons (PAH's) in the subsurface at the site of a former manufactured gas plant. Fifty-seven samples of unconsolidated subsurface sediments were aseptically obtained from five boreholes across the site. Bacteria capable of aerobically degrading PAH's without an acclimation period were detected throughout shallow (2.7 m) and deep (24.7 m) areas of the subsurface in both relatively clean (<20 μg L -1 naphthalene) and contaminated (4400 μg L -1 naphthalene) zones. Significant ( p < 0.05) quantities of naphthalene (8±3% to 43±7%) and/or phenanthrene (3±1% to 31±3%) were mineralized in sediment-groundwater microcosms during 4 weeks of aerobic incubation at 22°C. Three samples out of 11 were able to aerobically mineralize significant quantities of benzene (6±2% to 24±1%). Of 11 samples tested for anaerobic mineralization, naphthalene biodegradation (7±1% to 13±2%) in the presence of N03 was observed in two samples. Compound removals were first order with respect to substrate concentration during the first 10-15 days of incubation. Compound biodegradation plateaued in the later stages of incubation (15-40 days), most likely from diminishing bioavailability and nutrient and oxygen depletion. Population densities in the sediments were typically low, with viable aerobic counts ranging from 0 to 10 5 CFU gdw -1, viable anaerobic counts ranging from 0 to 104 CFU gdw -1, and total counts (AODC) usually 10-fold greater than viable counts. Total counts exhibited a strong ( p < 0.01) positive correlation with sample grain size. Viable aerobic and anaerobic populations commonly occurred in the same sample, suggesting the presence of facultative anaerobes. Bacteria were metabolically active in samples from groundwaters with low pH (3.7) and high naphthalene concentrations (11,000 μg L -1). Data from these enumeration and microcosm studies suggest that natural in situ biodegradation is occurring at the site.

PCDD/F, PAH and heavy metals in the sewage sludge from six wastewater treatment plants in Beijing, China.

PubMed

Dai, Jiayin; Xu, Muqi; Chen, Jiping; Yang, Xiangping; Ke, Zhenshan

2007-01-01

In order to better understand land application of sewage sludge, the characterization of heavy metals, PCDD/F and PAHs in sewage sludge was investigated from six different wastewater treatment plants (WWTP) in Beijing City, China. It was found that the total concentrations of Zn in Wujiacun (WJC) sewage sludge, and Cd and Hg in sewage sludge generated from all of the six different places are higher than Chinese regulation limit of pollutants for sludge to be used for agriculture (GB18918-2002). The levels of 16 PAHs that have been categorized as priority pollutants by US EPA in the sewage sludge samples varied from 2467 to 25923 microg/kg (dry weight), the highest values of 25923 microg/kg being found in WJC WWTP. The concentrations of Benzo[a]pyrene were as high as 6.1mg/kg dry weight in WJC sewage sludge, exceeding the maximum permitted content by GB18918-2002. Individual PAH content varies considerably with sewage samples. The ratios of anthracene to anthracene plus phenanthrene (An/178), benz[a]anthracene to benz[a]anthracene plus chrysene (BaA/228), indene[1,2,3-cd]pyrene to indene[1,2,3-cd]pyrene plus benzo[g,h,i]perylene (In/In+BP), and fluoranthene to fluoranthene plus pyrene (Fl/Fl+Py) suggest that petroleum and combustion of fossil fuel were the dominant contributions for the PAHs in sewage sludge. The concentrations of total PCDD/F in the sewage sludge ranged from 330 to 4245 pg/g d.w. The toxicity equivalent concentrations is between 3.47-88.24 pg I-TEQ according to NATO/CCMS, which is below Chinese legislation limit value proposed for land application. The PCDD/F congener/homologue profiles found in the Beijing samples indicated that the high chlorinated PCDD/F contamination might originate mainly from PCP-related source and depositional sources while the low chlorinated PCDD/F homologues could be originating from incineration or coal combustion. The major source of PCDD/Fs in Beijing sludge is still unclear.

Airborne Measurements of atmospheric PAH's across Europe

NASA Astrophysics Data System (ADS)

Davison, B.; Jaward, F.; Jones, K.; Lee, R.

2003-04-01

Atmospheric measurements of PAHs were taken aboard the DRL Falcon 20 during May 2001. A sampling system was designed to work aboard this aircraft platform. Particulate PAHs were collected on a glass fiber filter (GFF) with their gaseous component concentrated on a polyurethane foam sheets located behind the filter. Typically sampling volumes of between 20-50m^3 were collected which equated to a collection time of about 30minutes. In this way the distance travelled was kept within an acceptable level, about 60 nautical miles. The average concentrations of the data set for phenanthrene was 450 pg m-3 while values for many of the heavier PAH marker compounds used in the UK such as benzo(a)pyrene, diben(ah)anthracene were below the detection limits on all flights. The results will be discussed with consideration of location, altitude and airmass trajectory.

Polycyclic aromatic hydrocarbons in sediments and mussels of Corral Bay, south central Chile.

PubMed

Palma-Fleming, Hernan; P, Adalberto J Asencio; Gutierrez, Elena

2004-03-01

PAHs were measured in sediments and mussels (Mytilus chilensis) from Carboneros and Puerto Claro, located in Corral Bay, Valdivia. According to the ratio of phenanthrene/anthracene and fluoranthene/pyrene concentrations, these sites are medium polluted with PAHs originating mainly from pyrolytic sources. Fluoranthene was the major component measured in mussels (3.1-390 ng g(-1) dry weight) and sediments (6.9-74.1 ng g(-1) dry weight). In general, mussels were mainly exposed to the dissolved fraction of the lower molecular weight PAHs (tri- and tetra-aromatics) while the higher molecular ring systems (penta- and hexa-aromatics) were more bioavailable to sediments. Mussel PAHs content was relatively constant, with the exception of the 1999 summer season (March), when higher concentration values were found in both sites; however, PAHs residues in sediments showed a temporal variation.

High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons: The Realm of Anharmonicity

NASA Technical Reports Server (NTRS)

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

2016-01-01

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micrometers CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold ((is) approximately 4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main modes that fall within 0.5% of the experimental frequencies. The implications for the Aromatic Infrared Bands, specifically the 3-m band are discussed.

HIGH-RESOLUTION IR ABSORPTION SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS: THE REALM OF ANHARMONICITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maltseva, Elena; Buma, Wybren Jan; Petrignani, Annemieke

2015-11-20

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3-μm CH stretching region of polycyclic aromatic hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (∼4 K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computationalmore » program SPECTRO, providing anharmonic predictions with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main bands that fall within 0.5% of the experimental frequencies. The implications for the aromatic infrared bands, specifically the 3-μm band, are discussed.« less

Coliform Bacteria for Bioremediation of Waste Hydrocarbons

PubMed Central

2017-01-01

Raw, domestic sewage of Kuwait City contained about 106 ml−1 colony forming units of Enterobacter hormaechei subsp. oharae (56.6%), Klebsiella spp. (36%), and Escherichia coli (7.4%), as characterized by their 16S rRNA-gene sequences. The isolated coliforms grew successfully on a mineral medium with crude oil vapor as a sole source of carbon and energy. Those strains also grew, albeit to different degrees, on individual n-alkanes with carbon chains between C9 and C36 and on the individual aromatic hydrocarbons, toluene, naphthalene, phenanthrene, and biphenyl as sole sources of carbon and energy. These results imply that coliforms, like other hydrocarbonoclastic microorganisms, oxidize hydrocarbons to the corresponding alcohols and then to aldehydes and fatty acids which are biodegraded by β-oxidation to acetyl CoA. The latter is a well-known key intermediate in cell material and energy production. E. coli cells grown in the presence of n-hexadecane (but not in its absence) exhibited typical intracellular hydrocarbon inclusions, as revealed by transmission electron microscopy. Raw sewage samples amended with crude oil, n-hexadecane, or phenanthrene lost these hydrocarbons gradually with time. Meanwhile, the numbers of total and individual coliforms, particularly Enterobacter, increased. It was concluded that coliform bacteria in domestic sewage, probably in other environmental materials too, are effective hydrocarbon-biodegrading microorganisms. PMID:29082238

Polycyclic aromatic hydrocarbons bioaccessibility in seafood: Culinary practices effects on dietary exposure.

PubMed

Dos Santos Fogaça, Fabíola Helena; Soares, Cristina; Oliveira, Marta; Alves, Ricardo N; Maulvault, Ana L; Barbosa, Vera L; Anacleto, Patrícia; Magalhães, João Avelar; Bandarra, Narcisa M; Ramalhosa, Maria João; Morais, Simone; Marques, António

2018-07-01

This work aimed to determine the effect of culinary practices on the contamination level and bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in seafood. The selected farmed seafood species (marine shrimp, clams and seaweed) were commercially available in Portugal. The mean concentrations of PAHs varied between 0.23 and 51.8 µg kg -1 , with the lowest value being observed in raw shrimp and the highest in dried seaweed. The number of compounds detected in seaweed and clams (naphthalene, acenaphthene, fluorene, phenanthrene, benzo(b)fluoranthene and benzo(j)fluoranthene) were higher than in shrimp (fluorene and pyrene). Among the PAHs measured, fluorene was the predominant one. There was a significant interaction effect between species and culinary treatment (p < 0.05), thus boiled and dried seaweed samples presented the lowest and the highest levels of fluorene (0.13 and 1.8 µg kg -1 ), respectively. The daily intake of PAHs decreased with bioaccessibility, varying from 22% for benzo(k)fluoranthene (in raw clam) to 84% for phenanthrene (in steamed clam). According to the potency equivalent concentrations, screening values and bioaccessibility of PAHs, the consumption of marine shrimp, clam and seaweed is considered as safe for consumers. Copyright © 2018 Elsevier Inc. All rights reserved.

Distribution and Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Dissolved Phase, Suspended Particulate Matter and Sediment from Weihe River in Northwest China

PubMed Central

Chen, Yuyun; Jia, Rui; Yang, Shengke

2015-01-01

Weihe River is a typical river located in the arid and semi-arid regions of Northwest China. In this study, the distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in Weihe River were investigated. The concentrations of ∑PAHs ranged from 351 to 4427 ng/L with a mean value of 835.4 ng/L in water dissolved phase (WDP), from 3557 ng/L to 147,907 ng/L with a mean value of 20,780 ng /L in suspended particulate matter (SPM), and from 362 to 15,667 ng/g dry weight (dw) with a mean value of 2000 ng/g dw in sediment, respectively. The concentrations of PAHs in Weihe River were higher compared with other rivers in the world. In both WDP and sediment, the highest concentrations of ∑PAHs were observed in the middle reach, while the lowest concentrations of ∑PAHs were found in the lower reach. For SPM, however, the PAHs concentrations in the lower reach were highest and the PAHs concentrations in the upper reach were lowest. The ratios of anthracene/(anthracene + phenanthrene) and fluoranthene/(fluoranthene + pyrene) reflected a pattern of both pyrolytic and petrogenic input of PAHs in Weihe River. The potential ecosystem risk assessment indicated that harmful biological impairments occur frequently in Weihe River. PMID:26561824

The relative abundance and seasonal distribution correspond with the sources of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of Chenab River, Pakistan.

PubMed

Hussain, Imran; Syed, Jabir Hussain; Kamal, Atif; Iqbal, Mehreen; Eqani, Syed-Ali-Mustjab-Akbar-Shah; Bong, Chui Wei; Taqi, Malik Mumtaz; Reichenauer, Thomas G; Zhang, Gan; Malik, Riffat Naseem

2016-06-01

Chenab River is one of the most important rivers of Punjab Province (Pakistan) that receives huge input of industrial effluents and municipal sewage from major cities in the Central Punjab, Pakistan. The current study was designed to evaluate the concentration levels and associated ecological risks of USEPA priority polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of Chenab River. Sampling was performed from eight (n = 24) sampling stations of Chenab River and its tributaries. We observed a relatively high abundance of ∑16PAHs during the summer season (i.e. 554 ng g(-1)) versus that in the winter season (i.e. 361 ng g(-1)), with an overall abundance of two-, five- and six-ring PAH congeners. Results also revealed that the nitrate and phosphate contents in the sediments were closely associated with low molecular weight (LMW) and high molecular weight (HMW) PAHs, respectively. Source apportionment results showed that the combustion of fossil fuels appears to be the key source of PAHs in the study area. The risk quotient (RQ) values indicated that seven PAH congeners (i.e. phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)pyrene, chrysene and benzo(a)anthracene) could pose serious threats to the aquatic life of the riverine ecosystem in Pakistan.

Occupational exposure to aromatic hydrocarbons and polycyclic aromatic hydrocarbons at a coke plant.

PubMed

Bieniek, Grażyna; Łusiak, Agnieszka

2012-08-01

The objective of this study was to assess the external exposure to aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) of coke-oven workers and by-product workers at a coke plant in Poland. The content of benzene, toluene, xylene, and naphthalene in a gaseous phase and the content of dibenzo[a,h]anthracene, benz[a]anthracene, anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benz[ghi]perylene, chrysene, and indeno[1,2,3-c,d]pyrene in a particulate phase of coke plant workers were measured in the workers mentioned above. A toxic equivalency factor BaP(eq) was used to estimate human health risk associated with respiratory exposure to PAHs. Time-weighted values of the exposure to AHs in the coke plant were as follows: benzene (range 0.01-2.71 mg m(-3)), toluene (0.01-1.73 mg m(-3)), xylene (0.01-0.78 mg m(-3)), naphthalene (6.0-6079 μg m(-3)), and the concentrations of hydrocarbons did not exceed the exposure limits. The results for particle-bound PAHs were equal to 1.96 μg m(-3) for B(a)P, 0.73 μg m(-3) for DBA, 3.23 μg m(-3) for BaA, 4.35 μg m(-3) for BbF, 3.02 μg m(-3) for BkF, 4.54 μg m(-3) for IND, 4.32 μg m(-3) for CHR, and 0.73 μg m(-3) for Ant. The results of personal air measurements (median values of the sum of nine carcinogenic PAHs) were 2.115 μg m(-3) (coke-oven workers, n = 207), 0.326 μg m(-3) (coke by-product workers, n = 33), and 0.653 μg m(-3) (total area workers, n = 38). The benzo[a]pyrene equivalent concentrations (BaP(eq)) of 10 PAHs were 1.33, 0.183, and 0.284 μg m(-3), respectively. We found out that coke plant workers are simultaneously exposed to a mixture of aromatic and polycyclic hydrocarbons present in the breathing zone air. Exposure levels are significantly influenced by job categories. Coke by-product workers are significantly more exposed to benzene, toluene, and xylene and less to PAHs. Coke-oven workers are mainly exposed to PAHs. Coke-oven workplaces (top side, coke side, and push side) are characterized by higher carcinogenic risk than other coke plant workplaces.

A comparative study of the structures and electronic properties of graphene fragments: A DFT and MP2 survey

NASA Astrophysics Data System (ADS)

de Carvalho, E. F. V.; Lopez-Castillo, A.; Roberto-Neto, O.

2018-01-01

Graphene can be viewed as sheet of benzene rings fused together forming a variety of structures including the trioxotriangulenes (TOTs) which is a class of organic molecules with electro-active properties. In order to clarify such properties, structures and electronic properties of the graphene fragments phenalenyl, triangulene, 6-oxophenalenoxyl, and X3TOT (X = H, F, Cl) are computed. Validation of the methodologies are carried out using the density functionals B3LYP, M06-2X, B2PLYP-D, and the MP2 theory, giving equilibrium geometries of benzene, naphthalene, and anthracene with mean unsigned error (MUE) of only 0.003, 0.007, 0.004, and 0.007 Å, respectively in relation to experiment.

Theoretical infrared spectra of some model polycyclic aromatic hydrocarbons - Effect of ionization

NASA Technical Reports Server (NTRS)

De Frees, D. J.; Miller, M. D.; Talbi, D.; Pauzat, F.; Ellinger, Y.

1993-01-01

In order to test the hypothesis of ionized PAHs as possible carriers of the UIR bands, we realized a computational exploration on selected PAHs of small dimension in order to identify which changes ionization would induce on their IR spectra. In this study we performed ab initio calculations of the spectra of neutral and positively ionized naphthalene, anthracene, and pyrene. The results are significantly important. The frequencies in the cations are slightly shifted with respect to the neutral species, but no general conclusion can be reached from the three molecules considered. By contrast, the relative intensities of most vibrations are strongly affected by ionization, leading to a much better agreement between the calculated CH/CC vibration intensity ratios and those deduced from observations.

Magnetic micro-solid-phase-extraction of polycyclic aromatic hydrocarbons in water.

PubMed

Naing, Nyi Nyi; Yau Li, Sam Fong; Lee, Hian Kee

2016-04-01

A novel sorbent, magnetic chitosan functionalized graphene oxide (MCFG) was synthesized and used in the micro-solid-phase-extraction (μ-SPE) and gas chromatography-mass spectrometric (GC-MS) analysis of polycyclic aromatic hydrocarbons (PAHs) from water. Through the use of the magnetic sorbent, the μ-SPE device also functioned as a stir bar during extraction. Three types of MCFG were prepared using glutaraldehyde cross-linked chitosan and graphene oxide with different amounts of magnetic nanoparticles (Fe3O4) (0.05g, 0.07g and 0.1g). The material was characterized using Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Parameters affecting the extraction such as the type of sorbent, extraction and desorption times, volume of sample solution and type of desorption solvent were optimized. Under the most favourable conditions, the highest extraction was obtained by using the composite prepared with 0.1g of Fe3O4. For the latter material as sorbent, the linearity of the analytes was in the range of 0.01 and 100μgL(-1) for naphthalene, fluoranthene and pyrene while acenaphthylene and phenanthrene exhibited linearity in the range of 0.05 and 100μgL(-1). For fluorene and anthracene, the linearity range was from 0.01 to 50μgL(-1). The coefficients of determination (r(2)) associated with the above linear ranges were higher than 0.987. The limits of detection from GC-MS analysis of the seven PAHs were in the range 0.2-1.8ngL(-1); limits of quantification were between 0.8 and 5.9ngL(-1) while the relative standard deviations (RSDs) varied from 2.1 to 8.2%. The recoveries of the method for the compounds at spiking levels of 1 and 5μgL(-1) were in the range 67.5-106.9% with RSDs below 15%. The enrichment factors were found to be in between 67 and 302. The developed method afforded an interesting and innovative approach using MCFG as an efficient and promising sorbent. Copyright © 2016 Elsevier B.V. All rights reserved.

Systematic developmental neurotoxicity assessment of a representative PAH Superfund mixture using zebrafish.

PubMed

Geier, Mitra C; James Minick, D; Truong, Lisa; Tilton, Susan; Pande, Paritosh; Anderson, Kim A; Teeguardan, Justin; Tanguay, Robert L

2018-04-06

Superfund sites often consist of complex mixtures of polycyclic aromatic hydrocarbons (PAHs). It is widely recognized that PAHs pose risks to human and environmental health, but the risks posed by exposure to PAH mixtures are unclear. We constructed an environmentally relevant PAH mixture with the top 10 most prevalent PAHs (SM10) from a Superfund site derived from environmental passive sampling data. Using the zebrafish model, we measured body burden at 48 hours post fertilization (hpf) and evaluated the developmental and neurotoxicity of SM10 and the 10 individual constituents at 24 hours post fertilization (hpf) and 5 days post fertilization (dpf). Zebrafish embryos were exposed from 6 to 120 hpf to (1) the SM10 mixture, (2) a variety of individual PAHs: pyrene, fluoranthene, retene, benzo[a]anthracene, chrysene, naphthalene, acenaphthene, phenanthrene, fluorene, and 2-methylnaphthalene. We demonstrated that SM10 and only 3 of the individual PAHs were developmentally toxic. Subsequently, we constructed and exposed developing zebrafish to two sub-mixtures: SM3 (comprised of 3 of the developmentally toxicity PAHs) and SM7 (7 non-developmentally toxic PAHs). We found that the SM3 toxicity profile was similar to SM10, and SM7 unexpectedly elicited developmental toxicity unlike that seen with its individual components. The results demonstrated that the overall developmental toxicity in the mixtures could be explained using the general concentration addition model. To determine if exposures activated the AHR pathway, spatial expression of CYP1A was evaluated in the 10 individual PAHs and the 3 mixtures at 5 dpf. Results showed activation of AHR in the liver and vasculature for the mixtures and some individual PAHs. Embryos exposed to SM10 during development and raised in chemical-free water into adulthood exhibited decreased learning and responses to startle stimulus indicating that developmental SM10 exposures affect neurobehavior. Collectively, these results exemplify the utility of zebrafish to investigate the developmental and neurotoxicity of complex mixtures. Copyright © 2018 Elsevier Inc. All rights reserved.

Pyopneumothorax following suicidal kerosene ingestion

PubMed Central

Verma, S K; Kapoor, Neha; Bhaskar, Ravi; Upadhyay, Rashmi

2012-01-01

Liquid hydrocarbons derived from petroleum are widely used in household and industry. Many hydrocarbons in kerosene, such as hexane, naphthalene, octane and phenanthrene, are toxic to humans. Pulmonary toxicity is the major cause of morbidity and mortality followed by central nervous-system and cardiovascular complications.1 As kerosene is a mixture of chemicals, there is no definitive absorption, distribution, metabolism and excretion. The major route of exposure is by inhalation of liquid (aspiration). Kerosene vapours may be mildly irritating to the respiratory system and spray applications of kerosene may provoke signs of pulmonary irritation such as coughing and dyspnoea. Kerosene aspiration leads to inflammation and loss of surfactant. Secondary effects in the lungs include pneumothorax, pneumatocele or bronchopleural fistula. Here, we are presenting a case of pyopneumothorax after kerosene consumption. PMID:23257648

Roles of aromatic side chains and template effects of the hydrophobic cavity of a self-assembled peptide nanoarchitecture for anisotropic growth of gold nanocrystals.

PubMed

Tomizaki, Kin-ya; Kishioka, Kohei; Kobayashi, Hiroki; Kobayashi, Akitsugu; Yamada, Naoki; Kataoka, Shunsuke; Imai, Takahito; Kasuno, Megumi

2015-11-15

Gold nanocrystals are promising as catalysts and for use in sensing/imaging systems, photonic/plasmonic devices, electronics, drug delivery systems, and for photothermal therapy due to their unique physical, chemical, and biocompatible properties. The use of various organic templates allows control of the size, shape, structure, surface modification and topology of gold nanocrystals; in particular, currently the synthesis of gold nanorods requires a cytotoxic surfactant to control morphology. To control the shape of gold nanocrystals, we previously demonstrated the de novo design and synthesis of a β-sheet-forming nonapeptide (RU006: Ac-AIAKAXKIA-NH2, X=L-2-naphthylalanine, Nal) and the fabrication of gold nanocrystals by mixing RU006 and HAuCl4 in water. The reaction afforded ultrathin gold nanoribbons 50-100 nm wide, several nanometers high, and microns long. To understand the mechanism underlying gold nanoribbon formation by the RU006 system, we here report (i) the effects of replacement of the Nal aromatic side chain in the RU006 sequence with other aromatic moieties, (ii) the electrochemical properties of aromatic side chains in the de novo designed template peptides to estimate the redox potential and number of electrons participating in the gold crystallization process, and (iii) the stoichiometry of the RU006 system for gold nanoribbon synthesis. Interestingly, RU006 bearing a naphthalene moiety (oxidation peak potential of 1.50 V vs Ag/Ag(+)) and an analog [Ant(6)]-RU006 bearing a bulky anthracene moiety (oxidation peak potential of 1.05 V vs Ag/Ag(+)) allowed the growth of anisotropic (ribbon-like) and isotropic (round) gold nanocrystals, respectively. This trend in morphology of gold nanocrystals was attributed to spatially-arranged hydrophobic cavities sufficiently large to accommodate the gold precursor and to allow directed crystal growth driven by cross-linking reactions among the naphthalene rings. Support for this mechanism was obtained by decreasing the mole fraction of [Ant(6)]-RU006 against the total concentration of [Ant(6)]-RU006 and [Phe(6)]-RU006: absorption spectra similar to that for RU006 were obtained. Differences in the redox properties of the anthracene and naphthalene moieties scarcely affected morphology. We propose that construction of an appropriate hydrophobic cavity is important for templating gold nanocrystal architectures by peptide self-assembly. This mechanism would be applicable for developing simple, low toxicity, mild synthetic methods for constructing metallic nanomaterials for therapeutic use. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removing polycyclic aromatic hydrocarbons from water using granular activated carbon: kinetic and equilibrium adsorption studies.

PubMed

Eeshwarasinghe, Dinushika; Loganathan, Paripurnanda; Kalaruban, Mahatheva; Sounthararajah, Danious Pratheep; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

2018-05-01

Polycyclic aromatic hydrocarbons (PAHs) constitute a group of highly persistent, toxic and widespread environmental micropollutants that are increasingly found in water. A study was conducted in removing five PAHs, specifically naphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene, from water by adsorption onto granular activated carbon (GAC). The pseudo-first-order (PFO) model satisfactorily described the kinetics of adsorption of the PAHs. The Weber and Morris diffusion model's fit to the data showed that there were faster and slower rates of intra-particle diffusion probably into the mesopores and micropores of the GAC, respectively. These rates were negatively related to the molar volumes of the PAHs. Batch equilibrium adsorption data fitted well to the Langmuir, Freundlich and Dubinin-Radushkevich models, of which the Freundlich model exhibited the best fit. The adsorption affinities were related to the hydrophobicity of the PAHs as determined by the log K ow values. Free energies of adsorption calculated from the Dubinin-Radushkevich model and the satisfactory kinetic data fitting to the PFO model suggested physical adsorption of the PAHs. Adsorption of naphthalene, acenaphthylene and acenaphthene in fixed-bed columns containing a mixture of GAC (0.5 g) + sand (24.5 g) was satisfactorily simulated by the Thomas model.

Health-hazard evaluation report HETA 82-309-1630, Inland Steel, East Chicago, Indiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almaguer, D.; Orris, P.

1985-10-01

Environmental and breathing-zone samples were analyzed for polynuclear aromatic hydrocarbons (PAHs) and coal-tar-pitch volatiles at the Inland Steel Company, East Chicago, Indiana in November, 1982 and September, 1984. The evaluation was requested because of concern about employee exposures during maintenance of the coke battery precipitator at the number 2 facility. Four former employees were interviewed. The cyclohexane soluble fraction of coal-tar-pitch volatiles ranged from 0.232 to 0.668 mg/m/sup 3/. The OSHA standard is 0.15mg/m/sup 3/. Naphthalene concentrations up to 0.107mg/m/sup 3/ were detected. The OSHA standard for naphthalene is 50mg/m/sup 3/. Other PAHs detected included phenanthrene, fluorene and acenaphthene. Themore » employees reported experiencing local skin, eye, ear, nose, and throat irritation while working on the coke battery precipitator in the past. Personal protective measures such as wearing safety boots, barrier creams on exposed skin surfaces, and showering and changing clothes before leaving the facility were implemented. The authors conclude that a potential health hazard from PAHs and coal-tar-pitch volatiles is being adequately addressed by the facility. Recommendations include continuing the present personal protective measures and providing emergency rescue training.« less

Development and certification of a coal fly ash certified reference material for selected polycyclic aromatic hydrocarbons.

PubMed

Cao, X; Xu, X; Cui, W; Xi, Z

2001-08-01

The development and certification of a coal fly ash certified reference material (CRM) for polycyclic aromatic hydrocarbons (PAH) is described; this is the first natural matrix CRM for organic environmental analysis in China. The homogeneity and stability of this material have been tested by HPLC. The concentrations of several PAH were determined by use of two independent, different methods--solvent extraction-HPLC analysis with UV detection coupled with fluorescence detection (FLD) and solvent extraction, isolation with a silica column, and GC analysis with flame ionization detection (FID). Five certified values were determined: phenanthrene 7.1 +/- 2.6 microg g(-1), anthracene 2.0 +/- 0.8 microg g(-1), fluoranthene 7.4 +/- 1.9 microg g(-1), pyrene 7 +/- 2 microg g(-1), and benzo[a]pyrene 1.3 +/- 0.3 microg g(-1). Reference values for several other PAH are also suggested.

Solid-state surface luminescence of polycyclic aromatic hydrocarbons adsorbed on cellulose diacetate matrices

NASA Astrophysics Data System (ADS)

Rogacheva, Svetlana M.; Shipovskaya, Anna B.; Volkova, Elena V.; Khurshudyan, Grachia N.; Suska-Malawska, Malgorzata; Gubina, Tamara I.

2018-04-01

The spectral-kinetic characteristics of luminescence of 17 polycyclic aromatic hydrocarbons (PAH) sorbed from a "water-organic solvent" medium on cellulose diacetate (CDA) matrices were studied. A significant increase in the fluorescence signal on the CDA matrix was observed for 13 PAHs in comparison with aqueous solutions. The highest detection sensitivity was found for pyrene, benzo(a)pyrene, and benzo(k)fluoranthene. The fluorescence spectra of two PAH indicator pairs (anthracene-phenanthrene and pyrene-fluoranthene) used to control toxicant emission sources were studied with the simultaneous presence of isomers in the analyte, depending on the excitation wavelength. For both isomer pairs, it has been found that the spectra of their solid-state luminescence overlap insignificantly, the characteristic peaks do not coincide and do not overlap, the sensitivities of detection are close to each other, which makes it possible to consider this technique as promising to control PAH contamination sources.

Urinary hydroxy-metabolites of naphthalene, phenanthrene and pyrene as markers of exposure to diesel exhaust.

PubMed

Kuusimäki, Leea; Peltonen, Yrjö; Mutanen, Pertti; Peltonen, Kimmo; Savela, Kirsti

2004-01-01

The objective of this study was to assess the exposure of bus-garage and waste-collection workers to polycyclic aromatic hydrocarbons (PAHs) derived from diesel exhaust by the measurement of levels of seven urinary PAH metabolites: 2-naphthol, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1+9-hydroxyphenanthrene, 4-hydroxyphenanthrene and 1-hydroxypyrene. One urine sample from each of 46 control persons, and one pre-shift and two post-shift spot urine samples from 32 exposed workers were obtained in winter and in summer. The metabolites were analysed after enzymatic hydrolysis by high performance liquid chromatography (HPLC) with fluorescence detection. The sum of seven PAH metabolites (mean 3.94 +/- 3.40 and 5.60 +/- 6.37 micromol/mol creatinine in winter and summer, respectively) was higher [P=0.01, degrees of freedom (df) =61.2 and P=0.01, df=67.6 in winter and summer, respectively] in the exposed group than in the control group (mean 3.18 +/- 3.99 and 3.03 +/- 2.01 micromol/mol creatinine in winter and summer, respectively). The mean concentrations of 2-naphthol among exposed and controls ranged between 3.34 and 4.85 micromol/mol creatinine and 2.51 and 2.58 micromol/mol creatinine, respectively (P<0.01 in winter, P<0.03 in summer). The mean level of the hydroxyphenanthrenes in the samples of exposed workers was between 0.40 and 0.70 micromol/mol creatinine and in the control samples 0.40-0.60 micromol/mol creatinine. The concentration of 1-hydroxypyrene was higher among exposed workers in both pre-shift and post-shift samples (mean 0.10-0.15 micromol/mol creatinine) than in control group (mean 0.05-0.06 micromol/mol creatinine) in winter (P=0.002, df=78) and in summer (P<0.001, df=68). The urinary hydroxy-metabolites of naphthalene, phenanthrene and pyrene showed low exposure to diesel-derived PAHs; however, it was higher in exposed workers than in control group. Urinary PAH monohydroxy-metabolites measured in this study did not correlate with the PAHs in the air samples, reported earlier, in 2002 and 2003.

Photoionization of Benzene and Small Polycyclic Aromatic Hydrocarbons in Ultraviolet-Processed Astrophysical Ices: A Computational Study

NASA Technical Reports Server (NTRS)

Woon, D. E.; Park, J.-Y.

2004-01-01

We employed density functional theory (DFT) calculations to model the photoionization behavior of benzene and small polycyclic aromatic hydrocarbons when they are embedded in a matrix of water ice in order to investigate issues raised by recent experimental work by Gudipati and Allamandola. The ionization energies of benzene, naphthalene, anthracene, and pyrene were found to be lowered by 1.5-2.1 eV in water ice. Low-lying vertical electronic excitation energies were computed with time-dependent DFT for both neutral and ionized species and are found in both cases to be remarkably unaffected by the ice matrix. Chemical behavior in ultraviolet-photoprocessed ices is also discussed, with a focus on electron recombination and pathways leading to phenol and analogous products.

Analysis of particle and vapour phase PAHs from the personal air samples of bus garage workers exposed to diesel exhaust.

PubMed

Kuusimaki, Leea; Peltonen, Kimmo; Mutanen, Pertti; Savela, Kirsti

2003-07-01

The levels of particle and vapour phase polycyclic aromatic hydrocarbons (PAHs) derived from the diesel exhaust compounds in bus garage work were measured in winter and in summer. Five personal air samples were collected from the breathing zones of 22 garage workers every other day of consecutive weeks. Control samples (n = 22) were collected from office workers in Helsinki. Fifteen PAHs in the air samples were analysed by HPLC using a fluorescence detector. Statistically significant differences were observed between total PAH levels of the exposed workers (2241 and 1245 ng/m(3)) and the control group (254 and 275 ng/m(3)) in both winter (P < 0.001) and summer (P < 0.001). Phenanthrene, pyrene, benzo[ghi]perylene and fluoranthene were the major compounds in the particle phase, and naphthalene, phenanthrene and fluorene in the vapour phase. About 98% of PAHs measured were related to the vapour phase compounds, whereas the high molecular weight PAH compounds were detected only in the particle phase. The PAH levels in the garages were twice as high (P < 0.001) in winter as in summer. Even though the exposure levels were low in the bus garages, the low level does not allow conclusions to be drawn about the possible adverse health effects due to exposure to diesel exhaust.

Modulation of ethoxyresorufin O-deethylase and glutathione S-transferase activities in Nile tilapia (Oreochromis niloticus) by polycyclic aromatic hydrocarbons containing two to four rings: implications in biomonitoring aquatic pollution.

PubMed

Pathiratne, Asoka; Hemachandra, Chamini K

2010-08-01

Despite ubiquity of polycyclic aromatic hydrocarbons (PAHs) in the tropical environments, little information is available concerning responses of tropical fish to PAHs and associated toxicity. In the present study, effects of five PAHs containing two to four aromatic rings on hepatic CYP1A dependent ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST) and serum sorbitol dehydrogenase (SDH) activities in Nile tilapia, a potential fish species for biomonitoring pollution in tropical waters, were evaluated. Results showed that EROD activities were induced by the PAHs containing four aromatic rings (pyrene and chrysene) in a dose dependent manner. However PAHs with two to three aromatic rings (naphthalene, phenanthrene and fluoranthene) caused no effect or inhibition of EROD activities depending on the dose and the duration. Fluoranthene was the most potent inhibitor. SDH results demonstrated that high doses of fluoranthene induced hepatic damage. GST activity was induced by the lowest dose of phenanthrene, fluoranthene and chrysene but high doses had no effect. The results indicate that induction of EROD enzyme in Nile tilapia is a useful biomarker of exposure to PAHs such as pyrene and chrysene. However EROD inhibiting PAHs such as fluoranthene in the natural environment may modulate the EROD inducing potential of other PAHs thereby influencing PAH exposure assessments.

Endocrine disrupting potential of PAHs and their alkylated analogues associated with oil spills.

PubMed

Lee, Sangwoo; Hong, Seongjin; Liu, Xiaoshan; Kim, Cheolmin; Jung, Dawoon; Yim, Un Hyuk; Shim, Won Joon; Khim, Jong Seong; Giesy, John P; Choi, Kyungho

2017-09-20

Polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs are known to be major toxic contaminants in spills of petroleum hydrocarbons (oil). Spilled oil undergoes weathering and over time, PAHs go through a series of compositional changes. PAHs can disrupt endocrine functions, and the type of functions affected and associated potencies vary with the type and alkylation status of PAH. In this study, the potential of five major PAHs of crude oil, i.e., naphthalene, fluorene, dibenzothiophene, phenanthrene, and chrysene, and their alkylated analogues (n = 25), to disrupt endocrine functions was evaluated by use of MVLN-luc and H295R cell lines. In the MVLN-luc bioassay, seven estrogen receptor (ER) agonists were detected among 30 tested PAHs. The greatest ER-mediated potency was observed for 1-methylchrysene (101.4%), followed by phenanthrene and its alkylated analogues (range of %-E2max from 1.6% to 47.3%). In the H295R bioassay, significantly greater syntheses of steroid hormones were observed for 20 PAHs. For major PAHs and their alkylated analogues, disruption of steroidogenesis appeared to be more significant than ER-mediated effects. The number and locations of alkyl-moieties alone could not explain differences in the types or the potencies of toxicities. This observation shows that disruption of endocrine functions by some constituents of oil spills could be underestimated if only parent compounds are considered in assessments of hazard and risk.

Joint approximate diagonalization of eigenmatrices as a high-throughput approach for analysis of hyphenated and comprehensive two-dimensional gas chromatographic data.

PubMed

Zarghani, Maryam; Parastar, Hadi

2017-11-17

The objective of the present work is development of joint approximate diagonalization of eigenmatrices (JADE) as a member of independent component analysis (ICA) family, for the analysis of gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) data to address incomplete separation problem occurred during the analysis of complex sample matrices. In this regard, simulated GC-MS and GC×GC-MS data sets with different number of components, different degree of overlap and noise were evaluated. In the case of simultaneous analysis of multiple samples, column-wise augmentation for GC-MS and column-wise super-augmentation for GC×GC-MS was used before JADE analysis. The performance of JADE was evaluated in terms of statistical parameters of lack of fit (LOF), mutual information (MI) and Amari index as well as analytical figures of merit (AFOMs) obtained from calibration curves. In addition, the area of feasible solutions (AFSs) was calculated by two different approaches of MCR-BANDs and polygon inflation algorithm (FACPACK). Furthermore, JADE performance was compared with multivariate curve resolution-alternating least squares (MCR-ALS) and other ICA algorithms of mean-field ICA (MFICA) and mutual information least dependent component analysis (MILCA). In all cases, JADE could successfully resolve the elution and spectral profiles in GC-MS and GC×GC-MS data with acceptable statistical and calibration parameters and their solutions were in AFSs. To check the applicability of JADE in real cases, JADE was used for resolution and quantification of phenanthrene and anthracene in aromatic fraction of heavy fuel oil (HFO) analyzed by GC×GC-MS. Surprisingly, pure elution and spectral profiles of target compounds were properly resolved in the presence of baseline and interferences using JADE. Once more, the performance of JADE was compared with MCR-ALS in real case. On this matter, the mutual information (MI) values were 1.01 and 1.13 for resolved profiles by JADE and MCR-ALS, respectively. In addition, LOD values (μg/mL) were respectively 1.36 and 1.24 for phenanthrene and 1.26 and 1.09 for anthracene using MCR-ALS and JADE which showed outperformance of JADE over MCR-ALS. Copyright © 2017 Elsevier B.V. All rights reserved.

Occupational PAH exposures during prescribed pile burns.

PubMed

Robinson, M S; Anthony, T R; Littau, S R; Herckes, P; Nelson, X; Poplin, G S; Burgess, J L

2008-08-01

Wildland firefighters are exposed to particulate matter and gases containing polycyclic aromatic hydrocarbons (PAHs), many of which are known carcinogens. Our objective was to evaluate the extent of firefighter exposure to particulate and PAHs during prescribed pile burns of mainly ponderosa pine slash and determine whether these exposures were correlated with changes in urinary 1-hydroxypyrene (1-HP), a PAH metabolite. Personal and area sampling for particulate and PAH exposures were conducted on the White Mountain Apache Tribe reservation, working with 21 Bureau of Indian Affairs/Fort Apache Agency wildland firefighters during the fall of 2006. Urine samples were collected pre- and post-exposure and pulmonary function was measured. Personal PAH exposures were detectable for only 3 of 16 PAHs analyzed: naphthalene, phenanthrene, and fluorene, all of which were identified only in vapor-phase samples. Condensed-phase PAHs were detected in PM2.5 area samples (20 of 21 PAHs analyzed were detected, all but naphthalene) at concentrations below 1 microg m(-3). The total PAH/PM2.5 mass fractions were roughly a factor of two higher during smoldering (1.06 +/- 0.15) than ignition (0.55 +/- 0.04 microg mg(-1)). There were no significant changes in urinary 1-HP or pulmonary function following exposure to pile burning. In summary, PAH exposures were low in pile burns, and urinary testing for a PAH metabolite failed to show a significant difference between baseline and post-exposure measurements.

Soils impacted by PAHs: Would the stabilized organic matter be a green tool for the immobilization of these noxious compounds?

PubMed

Dores-Silva, Paulo R; Cotta, Jussara A O; Landgraf, Maria D; Rezende, Maria O O

2018-05-04

The objective of this study was to investigate the role of stabilized organic matter (vermicompost) and tropical soils in the sorption of naphthalene, anthracene and benzo[a]pyrene. The results obtained for the three compounds were extrapolated for the priority polycyclic aromatic hydrocarbons (PAHs) pollutants according to Environmental Protection Agency (US EPA). To evaluate the sorption process, high performance liquid chromatography was employed and the data was fitted by Freundlich isotherms. The results suggest that the sorption effect generally increases with the number of benzene rings of the PAHs, and that the persistence of PAHs in the environment is possibly related to the number of benzene rings in the PAH molecule. In addition, the pH of the vermicompost can strongly affect the adsorption process in this matrix.

NMR shifts for polycyclic aromatic hydrocarbons from first-principles

NASA Astrophysics Data System (ADS)

Thonhauser, T.; Ceresoli, Davide; Marzari, Nicola

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the 1H and 13 shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size.

Insights into the attenuated sorption of organic compounds on black carbon aged in soil.

PubMed

Luo, Lei; Lv, Jitao; Chen, Zien; Huang, Rixiang; Zhang, Shuzhen

2017-12-01

Sorption of organic compounds on fresh black carbons (BCs) can be greatly attenuated in soil over time. We examined herein the changes in surface properties of maize straw-derived BCs (biochars) after aged in a black soil and their effects on the sorptive behaviors of naphthalene, phenanthrene and 1,3-dinitrobenzene. Dissolved fulvic and humic acids extracted from the soil were used to explore the role of dissolved organic carbon (DOC) in the aging of biochars. Chromatography analysis indicated that DOC molecules with relatively large molecular weight were preferentially adsorbed on the biochars during the aging processes. DOC sorption led to blockage of the biochar's micropores according to N 2 and CO 2 adsorption analyses. Surface chemistry of the biochars was also substantially modified, with more O-rich functional groups on the aged biochars compared to the original biochars, as evidenced by Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. The changes in both the physical and chemical surface properties of biochars by DOC led to significant attenuation of the sorption capacity and nonlinearity of the nonionic organic compounds on the aged biochars. Among the tested organic compounds, phenanthrene was the most attenuated in its sorption by the aging treatments, possibly because of its relatively large molecular size and hydrophobicity. The information can help gain a mechanistic understanding of interactions between BCs and organic compounds in soil environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Seasonal variation of polycyclic aromatic hydrocarbons concentrations in urban streams at Niterói City, RJ, Brazil.

PubMed

Ribeiro, Angelo Morgado; da Rocha, Camila Coimbra Martins; Franco, Caroline Fernandes Jaegger; Fontana, Luiz Francisco; Pereira Netto, Annibal D

2012-12-01

Polycyclic aromatic hydrocarbons (PAHs) were determined in water samples collected in two streams and a lake located at Niteroi City, Rio de Janeiro State, Brazil between October 2008 and September 2009. Samples were extracted using liquid-liquid extraction and analyzed using high performance liquid chromatography with fluorescence detection. The limits of quantification were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian (50 ng/L) and USEPA legislations, with recoveries larger than 81.6%. Phenanthrene, fluoranthene, pyrene and benz[a]anthracene predominated among PAHs. Total concentrations of PAHs were well correlated with rainfall indicating a possible role of runoff to local pollution of water by PAHs and showed a seasonal variation in wet and dry seasons. Our results highlight the contribution of the widespread streams located around Guanabara Bay to the PAH burden found in its waters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

PubMed

Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

2017-10-01

Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polycyclic Aromatic Hydrocarbon (pah) In The Bulk Precipitation of The Seine Estuary, France

NASA Astrophysics Data System (ADS)

Motelay-Massei, A.; Ollivon, D.; Garban, B.; Chevreuil, M.

The evolution of industry and the rising of population have resulted in deep changes in the quality of the environment. Nowadays much more often the attention of analysts is focused on the presence of organic pollutants in precipitation, such as polycyclic aromatic hydrocarbons or pesticides. Atmospheric inputs play a significant role in semivolatile chemicals cycling and alter so the hydrological cycle. PAHs are semi- volatile organic contaminants of great environmental concern because of their car- cinogenic properties. PAHs are produced primarily during incomplete combustion of fossil fuels and wood. Major sources of PAHs to urban atmosphere include au- tomobile traffic, home heating, municipal incinerators and industrial emissions. De- spite their production in urban and industrial sites, PAHs occur at high concentra- tions in rural areas due to their persistence and ability to be transported over long distances. The aim of this investigation was to obtain information about occurrence of organic trace components in precipitation in the Seine Estuary. It was also of in- terest to investigate the spatial and temporal variability of PAHs in the bulk (wet and dry) deposition occurring in the estuary region and to estimate PAH deposition flux on watershed (urban, industrial or rural). Precipitation samples were collected at four locations in the Seine Estuary: the first is an industrial site (Le Havre), two are urban sites (Rouen, representative of urban area influenced by heavy traffic and Notre-Dame de Gravenchon, near from an industrial center) and the last one is ru- ral (Evreux). Each of the sites is located close to a meteorological station. Sam- pling is performed weekly since March 2001. In our analytical conditions, "total PAH" includes 15 compounds: naphthalene (NAP), acenaphtene (ACE), phenanthrene (PHE), anthracene (ANT), fluoranthene (FTH), pyrene (PYR), benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), dibenz(a,h)anthracene (DahA), benzo(g,h,i)perylene (BghiP) and indeno(1,2,3-cd)pyrene (IcdP). 130 precipitation samples were analyzed from March to October 2001. Analytical results indicated that PAHs were present in pre- cipitation in frequent basis. In spring the concentration of the PAHs varied between 4 ng.L-1 (Rouen, 14-21 May 2001) and 493 ng.L-1 (Le Havre, 14-21 May 2001) and were normally distributed. These values show good agreement with those measured in other sites in Europe. In addition the profile of the compounds was also similar. PHE 1 (18 to 24 %), FTH (18 to 22 %), PYR (10 to 13 %) were find in the highest concen- tration again. NAP contributed as much as 8 % to the total deposition at Le Havre, Rouen and Evreux and as 15 % at Notre-Dame de Gravenchon. This is probably due to relatively high solubility in water of NAP. Clouds arriving at our sites may contain NAP from distant as well as from local sources. The PAHs considered as carcinogenic (BaA, BbF, BkF, BaP, DahA, IcdP) by the International Association for Research on Cancer represent 14 to 25% of total PAHs. Wet deposition rates are also estimated: total fluxes ranged from 11 (Notre-Dame de Gravenchon) to 40 µg.m-2 (Le Havre) quarterly. This study assesses the seasonal and spatial variability in atmospheric de- position fluxes of these contaminants in the Seine Estuary. Spatial influences were observed and indicate both localized and long-range atmospheric source inputs and, indirectly, influence of direction and speed of winds. In addition, fluxes of PAHs seem to follow seasonal patterns, with increasing concentrations during the colder months of the year. These results highlighted the non-negligible contribution of atmospheric deposition to micropollutants supply to the watershed and consequently groundwater. Moreover, these chemical compounds, due to their high stability and residence times, could be used as tracers in the environment. 2

Binding of Diverse Environmental Chemicals with Human Cytochromes P450 2A13, 2A6, and 1B1 and Enzyme Inhibition

PubMed Central

Shimada, Tsutomu; Kim, Donghak; Murayama, Norie; Tanaka, Katsuhiro; Takenaka, Shigeo; Nagy, Leslie D.; Folkman, Lindsay M.; Foroozesh, Maryam K.; Komori, Masayuki; Yamazaki, Hiroshi; Guengerich, F. Peter

2014-01-01

A total of 68 chemicals including derivatives of naphthalene, phenanthrene, fluoranthene, pyrene, biphenyl, and flavone were examined for their abilities to interact with human P450s 2A13 and 2A6. Fifty-one of these 68 chemicals induced stronger Type I binding spectra (iron low- to high-spin state shift) with P450 2A13 than those seen with P450 2A6, i.e. the spectral binding intensities (ΔAmax/Ks ratio) determined with these chemicals were always higher for P450 2A13. In addition, benzo[c]phenanthrene, fluoranthene, 2,3-dihydroxy-2,3-dihydrofluoranthene, pyrene, 1-hydroxypyrene, 1-nitropyrene, 1-acetylpyrene, 2-acetylpyrene, 2,5,2’,5’-tetrachlorobiphenyl, 7-hydroxyflavone, chrysin, and galangin were found to induce a Type I spectral change only with P450 2A13. Coumarin 7-hydroxylation, catalyzed by P450 2A13, was strongly inhibited by 2’-methoxy-5,7-dihydroxyflavone, 2-ethynylnaphthalene, 2’-methoxyflavone, 2-naphththalene propargyl ether, acenaphthene, acenaphthylene, naphthalene, 1-acetylpyrene, flavanone, chrysin, 3-ethynylphenanthrene, flavone, and 7-hydroxyflavone; these chemicals induced Type I spectral changes with low Ks values. On the basis of the intensities of the spectral changes and inhibition of P450 2A13, we classified the 68 chemicals into eight groups based on the order of affinities for these chemicals and inhibition of P450 2A13. The metabolism of chemicals by P450 2A13 during the assays explained why some of the chemicals that bound well were poor inhibitors of P450 2A13. Finally, we compared the 68 chemicals for their abilities to induce Type I spectral changes of P450 2A13 with the Reverse Type I binding spectra observed with P450 1B1: 45 chemicals interacted with both P450s 2A13 and 1B1, indicating that the two enzymes have some similarty of structural features regarding these chemicals. Molecular docking analyses suggest similarities at the active sites of these P450 enzymes. These results indicate that P450 2A13, as well as Family 1 P450 enzymes, is able to catalyze many detoxication and activation reactions with chemicals of environmental interest. PMID:23432429

Simultaneous analysis of naphthols, phenanthrols, and 1-hydroxypyrene in urine as biomarkers of polycyclic aromatic hydrocarbon exposure: intraindividual variance in the urinary metabolite excretion profiles caused by intervention with beta-naphthoflavone induction in the rat.

PubMed

Elovaara, Eivor; Väänänen, Virpi; Mikkola, Jouni

2003-04-01

Two fluorimetric HPLC methods are described for the quantification of naphthols, phenanthrols and 1-hydroxypyrene (1-OHP) in urine specimens obtained from male Wistar rats exposed to naphthalene, phenanthrene and pyrene. The polycyclic aromatic hydrocarbons (PAHs) were given intraperitoneally, either alone (1.0 mmol/kg body weight) or as an equimolar mixture (0.33 mmol/kg), using the same dosages for repeated treatments on week 1 and week 2. Between these treatments, PAH-metabolizing activities encoded by aryl hydrocarbon (Ah) receptor-controlled genes were induced in the rats with beta-naphthoflavone (betaNF). Chromatographic separation of five phenanthrols (1-, 2-, 3-, 4-, and 9-isomers) was accomplished using two different RP C-18 columns. Despite selective detection (programmable wavelengths), the quantification limits in the urine ranged widely: 1-OHP (0.18 microg/l)

PAH distributions in sediments in the oil sands monitoring area and western Lake Athabasca: Concentration, composition and diagnostic ratios.

PubMed

Evans, Marlene; Davies, Martin; Janzen, Kim; Muir, Derek; Hazewinkel, Rod; Kirk, Jane; de Boer, Dirk

2016-06-01

Oil sands activities north of Fort McMurray, Alberta, have intensified in recent years with a concomitant debate as to their environmental impacts. The Regional Aquatics Monitoring Program and its successor, the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM), are the primary aquatic programs monitoring this industry. Here we examine sediment data (collected by Ekman grabs) to investigate trends and sources of polycyclic aromatic hydrocarbons (PAHs), supplementing these data with sediment core studies. Total PAH (ΣPAH) concentrations were highest at Shipyard Lake (6038 ± 2679 ng/g) in the development center and lower at Isadore's Lake (1660 ± 777 ng/g) to the north; both lakes are in the Athabasca River Valley and lie below the developments. ΣPAH concentrations were lower (622-930 ng/g) in upland lakes (Kearl, McClelland) located further away from the developments. ΣPAH concentrations increased at Shipyard Lake (2001-2014) and the Ells River mouth (1998-2014) but decreased in nearshore areas at Kearl Lake (2001-2014) and a Muskeg River (2000-2014) site. Over the longer term, ΣPAH concentrations increased in Kearl (1934-2012) and Sharkbite (1928-2010) Lakes. Further (200 km) downstream in the Athabasca River delta, ΣPAH concentrations (1029 ± 671 ng/g) increased (1999-2014) when %sands were included in the regression model; however, 50 km to the east, concentrations declined (1926-2009) in Lake Athabasca. Ten diagnostic ratios based on anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, indeno[123-cd]pyrene, dibenz[a,h]anthracene, dibenzothiophene and retene were examined to infer spatial and temporal trends in PAH sources (e.g., combustion versus petrogenic) and weathering. There was some evidence of increasing contributions of unprocessed oil sands and bitumen dust to Shipyard, Sharkbite, and Isadore's Lakes and increased combustion sources in the Athabasca River delta. Some CCME interim sediment quality guidelines were exceeded, primarily in Shipyard Lake and near presumed natural bitumen sources. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Investigating the Effects of Environmental Solutes on the Reaction Environment in Ice and at Ice Surfaces

NASA Astrophysics Data System (ADS)

Malley, Philip Patrick Anthony

The reaction environments present in water, ice, and at ice surfaces are physically distinct from one another and studies have shown that photolytic reactions can take place at different rates in the different media. Kinetics of reactions in frozen media are measured in snow and ice prepared from deionized water. This reduces experimental artifacts, but is not relevant to snow in the environment, which contains solutes. We have monitored the effect of nonchromophoric (will not absorb sunlight) organic matter on the photolytic fate of the polycyclic aromatic hydrocarbons (PAHs) phenanthrene, pyrene, and anthracene in ice and at ice surfaces. Nonchromophoric organic matter reduced photolysis rates to below our detection limit in bulk ice, and reduced rates at ice surfaces to a lesser extent due to the PAHs partially partitioning to the organics present. In addition, we have monitored the effect of chromophoric (will absorb sunlight) dissolved organic matter (cDOM) on the fate of anthracene in water, ice, and ice surfaces. cDOM reduced rates in all three media. Suppression in liquid water was due to physical interactions between anthracene and the cDOM, rather than to competitive photon absorbance. More suppression was observed in ice cubes and ice granules than in liquid water due to a freeze concentrating effect. Sodium Chloride (NaCl) is another ubiquitous environmental solute that can influence reaction kinetics in water, ice, and at ice surfaces. Using Raman microscopy, we have mapped the surface of ice of frozen NaCl solutions at 0.02M and 0.6M, as well as the surface of frozen samples of Sargasso Sea Water. At temperatures above and below the eutectic temperature (-21.1°C). Above the eutectic, regions of ice and liquid water were observed in all samples. Liquid regions generally took the form of channels. Channel widths and fractional liquid surface coverage increased with NaCl concentration and temperature. Volume maps of the three samples at temperatures above the eutectic point, showed that liquid channels were distributed throughout the ice sample. Liquid fractions were similar at ice surfaces and in the bulk at depths of at least 80 microm.

Birefringent Stable Glass with Predominantly Isotropic Molecular Orientation

NASA Astrophysics Data System (ADS)

Liu, Tianyi; Exarhos, Annemarie L.; Alguire, Ethan C.; Gao, Feng; Salami-Ranjbaran, Elmira; Cheng, Kevin; Jia, Tiezheng; Subotnik, Joseph E.; Walsh, Patrick J.; Kikkawa, James M.; Fakhraai, Zahra

2017-09-01

Birefringence in stable glasses produced by physical vapor deposition often implies molecular alignment similar to liquid crystals. As such, it remains unclear whether these glasses share the same energy landscape as liquid-quenched glasses that have been aged for millions of years. Here, we produce stable glasses of 9-(3,5-di(naphthalen-1-yl)phenyl)anthracene molecules that retain three-dimensional shapes and do not preferentially align in a specific direction. Using a combination of angle- and polarization-dependent photoluminescence and ellipsometry experiments, we show that these stable glasses possess a predominantly isotropic molecular orientation while being optically birefringent. The intrinsic birefringence strongly correlates with increased density, showing that molecular ordering is not required to produce stable glasses or optical birefringence, and provides important insights into the process of stable glass formation via surface-mediated equilibration. To our knowledge, such novel amorphous packing has never been reported in the past.

Infrared Spectra of Polycyclic Aromatic Hydrocarbons: Methyl Substitution and Loss of H

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W.; Langhoff, Stephen R.; Arnold, James O. (Technical Monitor)

1998-01-01

The B3LYP approach, in conjunction with the 4-31G basis set, is used to compute the harmonic frequencies of 1- and 2-methylnaphthalene, 1-, 2-, and 9-methylanthracene, and their cations. The IR spectra of the methyl substituted species are very similar to the parent spectra, except for the addition of the methyl C-H stretch at lower frequency than the aromatic C-H stretch. The loss of a single hydrogen from naphthalene, anthracene, and their cations is shown to have a very small effect on the IR spectra. Loss of a methyl hydrogen from 1- or 2-methylnaphthalene, or their cations, is shown to shift the side group C-H frequencies from below aromatic hydrogen stretching frequencies to above them. The loss of IT from 2-methylenenaphthalene shows only a small shift in the side group C-H stretching frequency.

Bioremediation of oil spills by whale microbes. Final report, 1994-1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, A.M.; Wachenheim, D.

1995-06-01

Baleen whale forestomach anaerobic microbes were studied for their ability to detoxify recalcitrant environmental pollutants; these include components of crude oil and some chlorinated aromatic compounds which are constituents of oil spills not biodegraded by aerobic microbes. In this study, forestomach rumen samples were collected on two occasions on the North Slope. When incubated with anthracene and naphthalene (PAH), these pollutants were degraded in the majority of sample sets. All simple aromatic hydrocarbons (benzine, toluene, xylenes, ethylbenzene) were degraded. PCBs were biodegraded by microbes from only two of the whales. Variable results were found with picric acid, trinitrotoluene (TNT), andmore » atrazine, and were likely due to analytical difficulties. Whale forestomach bacteria have adapted to an ecological niche where flow rates, mixing, and catabolism occur at rapid rates. These rates and the ability to metabolize complex molecules far exceed those of aerobic sediment and soil bacteria in biodegradation of environmental pollutants.« less

Process of changing the refractive index of a composite containing a polymer and a compound having large dipole moment and polarizability and applications thereof

NASA Technical Reports Server (NTRS)

Peyghambarian, Nasser (Inventor); Hendrickx, Eric (Inventor); Volodin, Boris (Inventor); Marder, Seth R. (Inventor); Kippelen, Bernard (Inventor)

2000-01-01

Fused ring bridge, ring locked dyes that form thermally stable photorfractive compositions. The fused ring bridge structures are .pi.-conjugated bonds in benzene-, naphthalene- or anthracene-derived fused ring systems that connect donor and acceptor groups. The donor and acceptor groups contribute to a high molecular dipole moment and linear polarizability anisotropy. The polarization characteristics of the dye molecules are stabilized since the bonds in the fused ring bridge are not susceptible to rotation, reducing the opportunity for photoisomerization. The dyes are compatible with polymeric compositions, including thermoplastics. The dyes are electrically neutral but have charge transport, electronic and orientational properties such that upon illumination of a composition containing the dye, the dye facilitates refractive index modulation and a photorefractive effect that can be utilized advantageously in numerous applications such as in optical quality devices and biological imaging.

Thermally stable molecules with large dipole moments and polarizabilities and applications thereof

NASA Technical Reports Server (NTRS)

Marder, Seth R. (Inventor); Peyghambarian, Nasser (Inventor); Kippelen, Bernard (Inventor); Volodin, Boris (Inventor); Hendrickx, Eric (Inventor)

2002-01-01

Disclosed are fused ring bridge, ring-locked dyes that form thermally stable photorefractive compositions. The fused ring bridge structures are .pi.-conjugated bonds in benzene-, naphthalene- or anthracene-derived fused ring systems that connect donor and acceptor groups. The donor and acceptor groups contribute to a high molecular dipole moment and linear polarizability anisotropy. The polarization characteristics of the dye molecules are stabilized since the bonds in the fused ring bridge are not susceptible to rotation, reducing the opportunity for photoisomerization. The dyes are compatible with polymeric compositions, including thermoplastics. The dyes are electrically neutral but have charge transport, electronic and orientational properties such that upon illumination of a composition containing the dye, the dye facilitates refractive index modulation and a photorefractive effect that can be utilized advantageously in numerous applications such as in optical quality devices and biological imaging.

Infrared frequencies and intensities for astrophysically important polycyclic aromatic hydrocarbon cations

NASA Technical Reports Server (NTRS)

Szczepanski, Jan; Vala, Martin

1993-01-01

Polycyclic aromatic hydrocarbons (PAHs) have been implicated as the carriers of the 'unidentified infrared' (UIR) emission bands observed from the interstellar medium. It has long been thought that these molecules, if present, probably exist as cations. In this paper we present infrared spectra of the cations of five moderate-sized PAHs. The PAH cations have been produced by low-energy electron impact and then trapped and stabilized in argon matrices at 12 K. To date, results have been obtained on naphthalene, anthracene, pyrene, perylene, and coronene. A common feature of the infrared spectra of all these cations is the very different intensity pattern of the ions compared to the neutral parents. Visible and (partial) infrared spectra of the coronene cation are also presented. It is shown that the out-of-plane CH bending mode shifts to a position very close to the UIR band at 11.3 microns. The astrophysical impact of these observations is discussed.

The converse approach to NMR chemical shifts from first-principles: application to finite and infinite aromatic compounds

NASA Astrophysics Data System (ADS)

Thonhauser, T.; Ceresoli, D.; Marzari, N.

2009-03-01

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the ^1H and ^13C shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size.

Atypical kinetic behavior of chloroperoxidase-mediated oxidative halogenation of polycyclic aromatic hydrocarbons.

PubMed

Aburto, Jorge; Correa-Basurto, Jose; Torres, Eduardo

2008-12-01

We have identified an atypical kinetic behavior for the oxidative halogenation of several polycyclic aromatic hydrocarbons (PAHs) by chloroperoxidase (CPO) from Caldariomyces fumago. This behavior resembles the capacity of some members of the P450 family to simultaneously recognize several substrate molecules at their active sites. Indeed, fluorometric studies showed that PAHs exist in solution as monomers and pi-pi dimers that interact to different extents with CPO. The dissociation constants of dimerization were evaluated for every single PAH by spectrofluorometry. Furthermore, docking studies also suggest that CPO might recognize either one or two substrate molecules in its active site. The atypical sigmoidal kinetic behavior of CPO in the oxidative halogenation of PAHs is explained in terms of different kinetic models for non-heteroatomic PAHs (naphthalene, anthracene and pyrene). The results suggest that the actual substrate for CPO in this study was the pi-pi dimer for all evaluated PAHs.

Hydrocarbons identified in extracts from estuarine water accommodated no. 2 fuel oil by gas chromatography-mass spectrometry

NASA Technical Reports Server (NTRS)

Lewis, B. W.; Walker, A. L.; Bieri, R. H.

1974-01-01

Results are presented on a computerized gas chromatograph-mass spectrometer analysis of methylene chloride and n-heptane extracts of a No. 2 fuel oil accommodated estuarine water sample. The analytical method is briefly described, and the limitations on the identifications are categorized. Some attempt was made to determine major and trace constituents in the water accommodate. Altogether 66 hydrocarbon compounds were identified specifically, and 75 compounds were partially identified. Seven compounds could be recognized as major constituents of the water accommodated oil and ten were present only as traces. The aromatic compounds found were alkyl benzenes, naphthalene, tetralin, indane, biphenyl, fluorene, anthracene, and some of their alkyl substituted isomers in the range of carbon numbers C7 to C15. Four n-alkanes, C10 to C13, were found along with four other assorted hydrocarbons.

Polycyclic aromatic hydrocarbon ions and the diffuse interstellar bands

NASA Technical Reports Server (NTRS)

Salama, F.; Allamandola, L. J.

1995-01-01

Neutral naphthalene (C10H8), phenanthrene (C14H10), and pyrene (C16H10) absorb strongly in the ultraviolet and may contribute to the extinction curve. High abundances are required to produce detectable structures. The cations of these Polycyclic Aromatic Hydrocarbons (PAHs) absorb in the visible. C10H8(+) has 12 discrete absorption bands which fall between 6800 and 5000 A. The strongest band at 6741 A falls close to the weak 6742 A diffuse interstellar band (DIB). Five other weaker bands also match DIBs. The possibility that C10H8(+) is responsible for some of the DIBs can be tested by searching for new DIBS at 6520, 6151, and 5965 A, other moderately strong naphthalene cation band positions. If C10H8(+) is indeed responsible for the 6742 A feature, it accounts for 0.3% of the cosmic carbon. The spectrum of C16H10(+) is dominated by a strong band at 4435 A in an Ar matrix and 4395 A in a Ne matrix, a position which falls very close to the strongest DIB, that at 4430 A. If C16H10(+), or a closely related pyrene-like ion is indeed responsible for the 4430 A feature, it accounts for 0.2% of the cosmic carbon. We also report an intense, very broad UV-to-visible continuum which is associated with both ions and could explain how PAHs convert interstellar UV and visible radiation into IR.

Neutral and ionized polycyclic aromatic hydrocarbons, diffuse interstellar bands and the ultraviolet extinction curve

NASA Technical Reports Server (NTRS)

Salama, Farid; Allamandola, Louis John

1993-01-01

Neutral naphthalene C10H8, phenanthrene C14H10 and pyrene C16H10 absorb strongly in the ultraviolet region and may contribute to the extinction curve. High abundances are required to produce detectable structures. The cations of these polycyclic aromatic hydrocarbons (PAHs) absorb in the visible C10H8(+) has 13 discrete absorption bands which fall between 6800 and 4500 A. The strongest band at 6741 A falls close to the weak 6742 A diffuse interstellar band (DIB). Five other weaker bands also match DIBs. The possibility that C10H8(+) is responsible for some of the DIBs can be tested by searching for new DIBs at 6520 and 6151 A, other strong naphthalene cation band positions. If C10H8(+) is indeed responsible for the 6742 A feature, it accounts for 0.3% of the cosmic carbon. The spectrum of C16H10(+) is dominated by a strong band at 4435 A in an Ar matrix and 4395 A in Ne, wavelengths which fall very close to the strongest DIB at 4430 A. If C16H10(+) or a closely related pyrene-like ion, is indeed responsible for the 4430 A feature, it accounts for 0.2% of the cosmic carbon. An intense, very broad UV-to-visible continuum is reported which is associated with both ions and could explain how PAHs convert interstellar UV and visible radiation into IR radiation.

Occupational PAH Exposures during Prescribed Pile Burns

PubMed Central

Robinson, M. S.; Anthony, T. R.; Littau, S. R.; Herckes, P.; Nelson, X.; Poplin, G. S.; Burgess, J. L.

2008-01-01

Wildland firefighters are exposed to particulate matter and gases containing polycyclic aromatic hydrocarbons (PAHs), many of which are known carcinogens. Our objective was to evaluate the extent of firefighter exposure to particulate and PAHs during prescribed pile burns of mainly ponderosa pine slash and determine whether these exposures were correlated with changes in urinary 1-hydroxypyrene (1-HP), a PAH metabolite. Personal and area sampling for particulate and PAH exposures were conducted on the White Mountain Apache Tribe reservation, working with 21 Bureau of Indian Affairs/Fort Apache Agency wildland firefighters during the fall of 2006. Urine samples were collected pre- and post-exposure and pulmonary function was measured. Personal PAH exposures were detectable for only 3 of 16 PAHs analyzed: naphthalene, phenanthrene, and fluorene, all of which were identified only in vapor-phase samples. Condensed-phase PAHs were detected in PM2.5 area samples (20 of 21 PAHs analyzed were detected, all but naphthalene) at concentrations below 1 μg m−3. The total PAH/PM2.5 mass fractions were roughly a factor of two higher during smoldering (1.06 ± 0.15) than ignition (0.55 ± 0.04 μg mg−1). There were no significant changes in urinary 1-HP or pulmonary function following exposure to pile burning. In summary, PAH exposures were low in pile burns, and urinary testing for a PAH metabolite failed to show a significant difference between baseline and post-exposure measurements. PMID:18515848

High-performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles.

PubMed

Zhu, Yang; Morisato, Kei; Hasegawa, George; Moitra, Nirmalya; Kiyomura, Tsutomu; Kurata, Hiroki; Kanamori, Kazuyoshi; Nakanishi, Kazuki

2015-08-01

The optimization of a porous structure to ensure good separation performances is always a significant issue in high-performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high-performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high-performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high-performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36,000 m(-1). Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans-stilbene with separation factor as 7 and theoretical plate number as 76,000 m(-1) for cis-stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long- established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Condensed Phase Membrane Introduction Mass Spectrometry with Direct Electron Ionization: On-line Measurement of PAHs in Complex Aqueous Samples

NASA Astrophysics Data System (ADS)

Termopoli, Veronica; Famiglini, Giorgio; Palma, Pierangela; Cappiello, Achille; Vandergrift, Gregory W.; Krogh, Erik T.; Gill, Chris G.

2016-02-01

Polycyclic aromatic hydrocarbons (PAHs) are USEPA regulated priority pollutants. Their low aqueous solubility requires very sensitive analytical methods for their detection, typically involving preconcentration steps. Presented is the first demonstrated `proof of concept' use of condensed phase membrane introduction mass spectrometry (CP-MIMS) coupled with direct liquid electron ionization (DEI) for the direct, on-line measurement of PAHs in aqueous samples. DEI is very well suited for the ionization of PAHs and other nonpolar compounds, and is not significantly influenced by the co-elution of matrix components. Linear calibration data for low ppb levels of aqueous naphthalene, anthracene, and pyrene is demonstrated, with measured detection limits of 4 ppb. Analytical response times (t10%-90% signal rise) ranged from 2.8 min for naphthalene to 4.7 min for pyrene. Both intra- and interday reproducibility has been assessed (<3% and 5% RSD, respectively). Direct measurements of ppb level PAHs spiked in a variety of real, complex environmental sample matrices is examined, including natural waters, sea waters, and a hydrocarbon extraction production waste water sample. For these spiked, complex samples, direct PAH measurement by CP-MIMS-DEI yielded minimal signal suppression from sample matrix effects (81%-104%). We demonstrate the use of this analytical approach to directly monitor real-time changes in aqueous PAH concentrations with potential applications for continuous on-line monitoring strategies and binding/adsorption studies in heterogeneous samples.

Polycyclic aromatic hydrocarbons in mountain soils of the subtropical Atlantic.

PubMed

Ribes, A; Grimalt, J O; Torres García, C J; Cuevas, E

2003-01-01

Surface soil samples from various altitudes on Tenerife Island, ranging from sea level up to 3400 m above mean sea level, were analyzed to study the distribution of 26 polycyclic aromatic hydrocarbons (PAHs) in a remote subtropical area. The stable atmospheric conditions in this island define three vertically stratified layers: marine boundary, trade-wind inversion, and free troposphere. Total PAH concentrations, 1.9 to 6000 microg/kg dry wt., were high when compared with those in tropical areas and in a similar range to those in temperate areas. In the marine boundary layer, fluoranthene (Fla), pyrene (Pyr), benz [a]anthracene (BaA), and chrysene (C + T) were largely dominant. The predominance of Fla over Pyr may reflect photo-oxidative processes during atmospheric transport, although coal combustion inputs cannot be excluded. The PAHs found in higher concentration in the soils from the inversion layer were benzo[b + j]fluoranthene (BbjF) + benzo[k]fluoranthene (BkF) > benzo[e]pyrene (BeP) approximately indeno[1,2, 3-cd]pyrene (Ind) > benzo[a]pyrene (BaP) approximately benzo[ghi]perylene (Bghi) > coronene (Cor) approximately dibenz[a,h]anthracene (Dib), reflecting that high temperatures and insolation prevent the accumulation of PAHs more volatile than BbjF in significant amounts. These climatic conditions involve a process of standardization that prevents the identification of specific PAH sources such as traffic, forest fires, or industrial inputs. Only soils with high total organic carbon (TOC) (e.g., 10-30%) preserve the more volatile compounds such as phenanthrene (Phe), methylphenanthrenes (MPhe), dimethylphenanthrenes (DMPhe), and retene (Ret). However, no relation between PAHs and soil TOC and black carbon (BC) was found. The specific PAH distributions of the free tropospheric region suggest a direct input from pyrolytic processes related to the volcanic emission of gases in Teide.

Description of Immundisolibacter cernigliae gen. nov., sp. nov., a high-molecular-weight polycyclic aromatic hydrocarbon-degrading bacterium within the class Gammaproteobacteria, and proposal of Immundisolibacterales ord. nov. and Immundisolibacteraceae fam. nov.

PubMed

Corteselli, Elizabeth M; Aitken, Michael D; Singleton, David R

2017-04-01

The bacterial strain TR3.2T was isolated from aerobic bioreactor-treated soil from a polycyclic aromatic hydrocarbon (PAH)-contaminated site in Salisbury, NC, USA. Strain TR3.2T was identified as a member of 'Pyrene Group 2' or 'PG2', a previously uncultivated cluster of organisms associated with the degradation of high-molecular-weight PAHs by stable-isotope probing. Based on its 16S rRNA gene sequence, the strain was classified as a member of the class Gammaproteobacteria but possessed only 90.5 % gene identity to its closest described relative, Methylococcus capsulatus strain Bath. Strain TR3.2T grew on the PAHs pyrene, phenanthrene, anthracene, benz[a]anthracene and fluorene, as well as the azaarene carbazole, and could additionally metabolize a limited number of organic acids. Optimal growth occurred aerobically under mesophilic temperature, neutral pH and low salinity conditions. Strain TR3.2T was catalase and oxidase positive. Predominant fatty acids were C17 : 0 cyclo and C16 : 0. Genomic G+C content of the single chromosome was 67.79 mol% as determined by complete genome sequencing. Due to the high sequence divergence from any cultivated species and its unique physiological properties compared to its closest relatives, strain TR3.2T is proposed as a representative of a novel order, family, genus and species within the class Gammaproteobacteria, for which the name Immundisolibacter cernigliae gen. nov., sp. nov. is proposed. The associated order and family are therefore proposed as Immundisolibacteralesord. nov. and Immundisolibacteraceaefam. nov. The type strain of the species is TR3.2T (=ATCC TSD-58T=DSM 103040T).

Degradation of phenanthrene by Trametes versicolor and its laccase.

PubMed

Han, Mun-Jung; Choi, Hyoung-Tae; Song, Hong-Gyu

2004-06-01

Phenanthrene is a three-ring polycyclic aromatic hydrocarbon and commonly found as a pollutant in various environments. Degradation of phenanthrene by white rot fungus Trametes versicolor 951022 and its laccase, isolated in Korea, was investigated. After 36 h of incubation, about 46% and 65% of 100 mg/l of phenanthrene added in shaken and static fungal cultures were removed, respectively. Phenanthrene degradation was maximal at pH 6 and the optimal temperature for phenanthrene removal was 30 degrees C. Although the removal percentage of phenanthrene was highest (76.7%) at 10 mg/l of phenanthrene concentration, the transformation rate was maximal (0.82 mg/h) at 100 mg/L of phenanthrene concentration in the fungal culture. When the purified laccase of T versicolor 951022 reacted with phenanthrene, phenanthrene was not transformed. The addition of redox mediator, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) or 1-hydroxybenzotriazole (HBT) to the reaction mixture increased oxidation of phenanthrene by laccase about 40% and 30%, respectively.

Distribution and human health risk assessment of PAHs in four fish species from a SW Atlantic estuary.

PubMed

Oliva, Ana L; La Colla, Noelia S; Arias, Andrés H; Blasina, Gabriela E; Lopez Cazorla, Andrea; Marcovecchio, Jorge E

2017-08-01

The aim of this study is to assess-for the first time-the concentration of the 16 polycyclic aromatic hydrocarbons (PAHs) in the muscle tissues of four fish species (Micropogonias furnieri, Cynoscion guatucupa, Ramnogaster arcuata, and Mustelus schmitti) from Bahía Blanca estuary, Argentina and to evaluate their sources, distribution, and the human health risks implicated. Considering the four species under study, mean total PAH concentrations showed the following decreasing accumulation trend: M. schmitti, R. arcuata, C. guatucupa, and M. furnieri. Low molecular weight PAHs, such as naphthalene and phenanthrene, were generally predominant, displaying properties of PAH mixtures generated from petrogenic pollution. Of the four fish species analyzed, M. furnieri was the only one that did not raise any human consumption warning. In the case of the other species, exceeding values were found above the safety human consumption guidelines. Nevertheless, the screening criteria for carcinogenic PAHs proposed by the USEPA indicated a good quality status for these fish species.

Monitoring the freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) around a Norwegian oil platform by holistic passive sampling.

PubMed

Harman, Christopher; Thomas, Kevin V; Tollefsen, Knut Erik; Meier, Sonnich; Bøyum, Olav; Grung, Merete

2009-11-01

In order to assess the environmental impact of aquatic discharges from the offshore oil industry, polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were deployed around an oil platform and at reference locations in the North Sea. Exposure to polycyclic aromatic hydrocarbons (PAH) and alkylated phenols (AP) was determined from passive sampler accumulations using an empirical uptake model, the dissipation of performance reference compounds and adjusted laboratory derived sampling rates. Exposure was relatively similar within 1-2 km of the discharge point, with levels dominated by short chained C1-C3 AP isomers (19-51 ngL(-1)) and alkylated naphthalenes, phenanthrenes and dibenzothiophenes (NPD, 29-45 ngL(-1)). Exposure stations showed significant differences to reference sites for NPD, but not always for more hydrophobic PAH. These concentrations are several orders of magnitude lower than those reported to give both acute and sub-lethal effects, although their long term consequences are unknown.

Immobilization of fungal laccase onto a nonionic surfactant-modified clay material: application to PAH degradation.

PubMed

Chang, Yi-Tang; Lee, Jiunn-Fwu; Liu, Keng-Hua; Liao, Yi-Fen; Yang, Vivian

2016-03-01

Nonionic surfactant-modified clay is a useful absorbent material that effectively removes hydrophobic organic compounds from soil/groundwater. We developed a novel material by applying an immobilized fungal laccase onto nonionic surfactant-modified clay. Low-water-solubility polycyclic aromatic hydrocarbons (PAHs) (naphthalene/phenanthrene) were degraded in the presence of this bioactive material. PAH degradation by free laccase was higher than degradation by immobilized laccase when the surfactant concentration was allowed to form micelles. PAH degradation by immobilized laccase on TX-100-modified clay was higher than on Brij35-modified clay. Strong laccase degradation of PAH can be maintained by adding surfactant monomers or micelles. The physical adsorption of nonionic surfactants onto clay plays an important role in PAH degradation by laccase, which can be explained by the structure and molecular interactions of the surfactant with the clay and enzyme. A system where laccase is immobilized onto TX-100-monomer-modified clay is a good candidate bioactive material for in situ PAHs bioremediation.

Spatial and temporal variation of freely dissolved PAHs in an urban river undergoing Superfund remediation

PubMed Central

Sower, GJ; Anderson, K.A.

2014-01-01

Urban rivers with a history of industrial use can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations and even the assessment of remediation efforts. Concentrations of 15 biologically available priority pollutant polycyclic aromatic hydrocarbons (PAHs) were measured over five years along 18.5 miles of the lower Willamette River using passive sampling devices and HPLC. The study area includes the Portland Harbor Superfund megasite with several PAH sources including remediation operations for coal tar at RM 6.3 west and an additional Superfund site, McCormick and Baxter, at RM 7 east consisting largely of creosote contamination. Study results show that organoclay capping at the McCormick and Baxter Superfund Site reduced PAHs from a pre-cap average of 440 ± 422 ng/L to 8 ± 3 ng/L post-capping. Results also reveal that dredging of submerged coal tar nearly tripled nearby freely dissolved PAH concentrations. For apportioning sources, fluoranthene/ pyrene and phenanthrene/anthracene diagnostic ratios from passive sampling devices were established for creosote and coal tar contamination and compared to published sediment values. PMID:19174872

Spatial and temporal variation of freely dissolved polycyclic aromatic hydrocarbons in an urban river undergoing Superfund remediation.

PubMed

Sower, Gregory James; Anderson, Kim A

2008-12-15

Urban rivers with a history of industrial use can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations and even the assessment of remediation efforts. Concentrations of 15 biologically available priority pollutant polycyclic aromatic hydrocarbons (PAHs) were measured over five years along 18.5 miles of the lower Willamette River using passive sampling devices and HPLC. The study area includes the Portland Harbor Superfund megasite with several PAH sources including remediation operations for coal tar at RM 6.3 west and an additional Superfund site, McCormick and Baxter, at RM 7 east consisting largely of creosote contamination. Study results show that organoclay capping at the McCormick and Baxter Superfund Site reduced PAHs from a precap average of 440 +/- 422 ng/L to 8 +/- 3 ng/L postcapping. Results also reveal that dredging of submerged coal tar nearly tripled nearby freely dissolved PAH concentrations. For apportioning sources, fluoranthene/pyrene and phenanthrene/anthracene diagnostic ratios from passive sampling devices were established for creosote and coal tar contamination and compared to published sediment values.

Ultrafast optical excitations in supramolecular metallacycles with charge transfer properties.

PubMed

Flynn, Daniel C; Ramakrishna, Guda; Yang, Hai-Bo; Northrop, Brian H; Stang, Peter J; Goodson, Theodore

2010-02-03

New organometallic materials such as two-dimensional metallacycles and three-dimensional metallacages are important for the development of novel optical, electronic, and energy related applications. In this article, the ultrafast dynamics of two different platinum-containing metallacycles have been investigated by femtosecond fluorescence upconversion and transient absorption. These measurements were carried out in an effort to probe the charge transfer dynamics and the rate of intersystem crossing in metallacycles of different geometries and dimensions. The processes of ultrafast intersystem crossing and charge transfer vary between the two different classes of metallacyclic systems studied. For rectangular anthracene-containing metallacycles, the electronic coupling between adjacent ligands was relatively weak, whereas for the triangular phenanthrene-containing structures, there was a clear interaction between the conjugated ligand and the metal complex center. The transient lifetimes increased with increasing conjugation in that case. The results show that differences in the dimensionality and structure of metallacycles result in different optical properties, which may be utilized in the design of nonlinear optical materials and potential new, longer-lived excited state materials for further electronic applications.

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

PubMed

Tecon, Robin; Binggeli, Olivier; van der Meer, Jan R

2009-09-01

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

Interactions among buffelgrass, phenanthrene and phenanthrene-degrading bacteria in gnotobiotic microcosms.

PubMed

Robert, Francoise M; Sun, Wenhao H; Toma, Marisa; Jones, Ryan K; Tang, Chung-Shih

2008-07-15

An experiment was undertaken in gnotobiotic microcosms to determine the role of buffelgrass (Cenchrus ciliaris) and a phenanthrene-degrading bacterium (strain PM600) in the degradation of phenanthrene. The Gram-negative bacterium was identified as a Sphingomonas sp. by 16S rRNA gene sequence analysis and as S. paucimobilis by biochemical tests (API 20 NE strips). Its yellow pigment corresponded to nostoxanthin and its cellular fatty acids were typical of the genus Sphingomonas. Moreover, it was devoid of lipopolysaccharides. Strain PM600 was tested for growth on mineral medium supplemented with No. 2 diesel, hexadecane, mineral oil, pristane, phenanthrene, and pyrene as single carbon sources. It was capable of utilizing phenanthrene only. In the gnotobiotic microcosms silica sand was either or not supplemented with 150 mg of phenanthrene kg(-1) sand, inoculated with strain PM600, and planted to sterile young seedlings of buffelgrass. After 28 days, 67% of the reduction of the phenanthrene concentration was assigned to degradation by the bacterium and ca. 20% to abiotic factors. No statistically significant effect of the young buffelgrass was found. In the absence of phenanthrene, the bacterial population significantly increased in the rhizosphere of buffelgrass. However, in the presence of buffelgrass and phenanthrene, the bacterial population preferentially responded to phenanthrene. The growth of buffelgrass was severely curtailed by phenanthrene in the absence of the bacterium. However, strain PM600 effectively protected buffelgrass against the phytotoxicity of phenanthrene.

Equation of motion coupled cluster methods for electron attachment and ionization potential in polyacenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhaskaran-Nair, Kiran; Kowalski, Karol; Jarrell, Mark

2015-11-05

Polyacenes have attracted considerable attention due to their use in organic based optoelectronic materials. Polyacenes are polycyclic aromatic hydrocarbons composed of fused benzene rings. Key to understanding and design of new functional materials is an understanding of their excited state properties starting with their electron affinity (EA) and ionization potential (IP). We have developed a highly accurate and com- putationally e*fficient EA/IP equation of motion coupled cluster singles and doubles (EA/IP-EOMCCSD) method that is capable of treating large systems and large basis set. In this study we employ the EA/IP-EOMCCSD method to calculate the electron affinity and ionization potential ofmore » naphthalene, anthracene, tetracene, pentacene, hex- acene and heptacene. We have compared our results with other previous theoretical studies and experimental data. Our EA/IP results are in very good agreement with experiment and when compared with the other theoretical investigations our results represent the most accurate calculations as compared to experiment.« less

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

PubMed

Veljković, Dušan Ž

2018-03-01

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

Enhanced aqueous solubility of polycyclic aromatic hydrocarbons by green diester-linked cationic gemini surfactants and their binary solutions

NASA Astrophysics Data System (ADS)

Panda, Manorama; Fatma, Nazish; Kabir-ud-Din

2016-07-01

Three homologues of a novel biodegradable diester-linked cationic gemini surfactant series, CmH2m+1 (CH3)2N+(CH2COOCH2)2N+(CH3)2CmH2m+1.2Cl- (m-E2-m; m = 12, 14, 16), were used for investigation of the solubilization of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, anthracene and pyrene in single as well as binary surfactant solutions. Physicochemical parameters of the pure/mixed systems were derived by conductivity and surface tension measurements. Dissolution capacity of the equimolar binary surfactant solutions towards the PAHs was studied from the molar solubilization ratio (MSR), micelle-water partition coefficient (Km) and free energy of solubilization (ΔGs0) of the solubilizates. Influence of hydrophobic chain length of the dimeric surfactants on solubilization was characterized. Aqueous solubility of the PAHs was enhanced linearly with concentration of the surfactant in all the pure and mixed gemini-gemini surfactant systems.

Electronic relaxation effects in condensed polyacenes: A high-resolution photoemission study

NASA Astrophysics Data System (ADS)

Rocco, M. L. M.; Haeming, M.; Batchelor, D. R.; Fink, R.; Schöll, A.; Umbach, E.

2008-08-01

We present a high-resolution photoelectron spectroscopy investigation of condensed films of benzene, naphthalene, anthracene, tetracene, and pentacene. High spectroscopic resolution and a systematic variation of the molecular size allow a detailed analysis of the fine structures. The line shapes of the C 1s main lines are analyzed with respect to the different contributions of inhomogeneous broadening, vibronic coupling, and chemical shifts. The shake-up satellite spectra reveal trends, which give insight into the charge redistribution within the molecule upon photoexcitation. In particular, the shake-up between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) increases in intensity and moves closer toward the C 1s main line if the size of the aromatic system is increased. An explanation is given on the basis of the delocalization of the aromatic system and its capability in screening the photogenerated core hole. A comparison of the HOMO-LUMO shake-up position to the optical band gap gives additional insight into the reorganization of the electronic system upon photoexcitation.

On The Geometric Nature of ``Singlet Fission'' in Certain Crystalline Conjugated Polymers

NASA Astrophysics Data System (ADS)

Rahman, Noah

2013-03-01

In recent years, the coherent fission of low-lying singlet electronic excitations in conjugated polymers has attracted interest as a possible way to exceed the Shockley-Queisser limit in organic photovoltaics. Femtosecond spectroscopic and fluorescence measurements of such singlets and the resulting triplets in crystalline anthracene, tetracene and naphthalene reveal curious phenomena associated with certain vibrational modes, such as ultrafast propagation on a timescale inconsistent with conventional intersystem crossing, long-lived electronic coherence, and triplet magnetic anisotropy whose structure is consistent across all three materials. This conflicts with NRG and quantum chemical simulations, which posit isotropic triplets. I explain this by a dynamical Rashba spin-orbit interaction that decays as R-6. This arises from a geometric SU(2) gauge potential generated by a nuclear-motion-induced parametric near-degeneracy of the molecular electronic states. The anisotropy is shown to follow from the work of Affleck and Oshikawa on spin one-half Heisenberg chains. Possible directions for future work are discussed, especially with regard to adiabatic pumping and topological insulators.

Succession of Phenotypic, Genotypic, and Metabolic Community Characteristics during In Vitro Bioslurry Treatment of Polycyclic Aromatic Hydrocarbon-Contaminated Sediments

PubMed Central

Ringelberg, David B.; Talley, Jeffrey W.; Perkins, Edward J.; Tucker, Samuel G.; Luthy, Richard G.; Bouwer, Edward J.; Fredrickson, Herbert L.

2001-01-01

Dredged harbor sediment contaminated with polycyclic aromatic hydrocarbons (PAHs) was removed from the Milwaukee Confined Disposal Facility and examined for in situ biodegradative capacity. Molecular techniques were used to determine the successional characteristics of the indigenous microbiota during a 4-month bioslurry evaluation. Ester-linked phospholipid fatty acids (PLFA), multiplex PCR of targeted genes, and radiorespirometry techniques were used to define in situ microbial phenotypic, genotypic, and metabolic responses, respectively. Soxhlet extractions revealed a loss in total PAH concentrations of 52%. Individual PAHs showed reductions as great as 75% (i.e., acenapthene and fluorene). Rates of 14C-PAH mineralization (percent/day) were greatest for phenanthrene, followed by pyrene and then chrysene. There was no mineralization capacity for benzo[a]pyrene. Ester-linked phospholipid fatty acid analysis revealed a threefold increase in total microbial biomass and a dynamic microbial community composition that showed a strong correlation with observed changes in the PAH chemistry (canonical r2 of 0.999). Nucleic acid analyses showed copies of genes encoding PAH-degrading enzymes (extradiol dioxygenases, hydroxylases, and meta-cleavage enzymes) to increase by as much as 4 orders of magnitude. Shifts in gene copy numbers showed strong correlations with shifts in specific subsets of the extant microbial community. Specifically, declines in the concentrations of three-ring PAH moieties (i.e., phenanthrene) correlated with PLFA indicative of certain gram-negative bacteria (i.e., Rhodococcus spp. and/or actinomycetes) and genes encoding for naphthalene-, biphenyl-, and catechol-2,3-dioxygenase degradative enzymes. The results of this study suggest that the intrinsic biodegradative potential of an environmental site can be derived from the polyphasic characterization of the in situ microbial community. PMID:11282603

Toxicity of effluents from gasoline stations oil-water separators to early life stages of zebrafish Danio rerio.

PubMed

Alves, Romulo Nepomuceno; Mariz, Célio Freire; Paulo, Driele Ventura de; Carvalho, Paulo S M

2017-07-01

Used petroleum hydrocarbons and gasoline stations runoff are significant sources of polycyclic aromatic hydrocarbons (PAHs) to aquatic ecosystems. Samples of the final effluent of oil-water-separators were collected at gasoline stations in the metropolitan region of Recife, Brazil, before release to sewage or rainwater systems. Effluent soluble fractions (ESF) were prepared and bioassays were performed according to the Fish Embryo Toxicity Test. The test involved exposing zebrafish Danio rerio embryos to dilutions of the ESFs for 96 h, with daily examination of lethality and sublethal morphological effects integrated through the General Morphology Score (GMS), based on the achievement of developmental hallmarks. Frequencies of abnormalities were recorded after exposures. ESF LC50-96h (lethal concentration to 50% of exposed embryos) in the most toxic effluent achieved 8.9% (v/v), equivalent to 11 μg phenanthrene equivalents L -1 . GMS scores indicated significantly delayed embryo-larval development at ESF dilutions of 10% and 20% from effluents of all gas stations. Major abnormalities detected after the 96 h exposure included the presence of a yolk sac not fully absorbed coupled with the lack of an inflated swim bladder, lack of both pectoral fins, and the failure to develop a protruding mouth. Effective equivalent PAH concentrations that induce a 50% frequency of larvae without an inflated swim bladder (EC50) were 4.9 μg phenanthrene L -1 , 21.8 μg naphthalene L -1 , and 34.1 μg chrysene L -1 . This study shows that PAHs in ESFs from gas stations oil water separators are toxic to zebrafish, contributing to the toxicity of urban storm waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does Switching to Reduced Ignition Propensity Cigarettes Alter Smoking Behavior or Exposure to Tobacco Smoke Constituents?

PubMed Central

Rees, Vaughan W.; Norton, Kaila J.; Cummings, K. Michael; Connolly, Gregory N.; Alpert, Hillel R.; Sjödin, Andreas; Romanoff, Lovisa; Li, Zheng; June, Kristie M.; Giovino, Gary A.

2010-01-01

Introduction: Since 2004, several jurisdictions have mandated that cigarettes show reduced ignition propensity (RIP) in laboratory testing. RIP cigarettes may limit fires caused by smoldering cigarettes, reducing fire-related deaths and injury. However, some evidence suggests that RIP cigarettes emit more carbon monoxide and polycyclic aromatic hydrocarbons, and smokers may alter their smoking patterns in response to RIP cigarettes. Both of these could increase smokers’ exposures to harmful constituents in cigarettes. Methods: An 18-day switching study with a comparison group was conducted in Boston, MA (N = 77), and Buffalo, NY (N = 83), in 2006–2007. Current daily smokers completed 4 laboratory visits and two 48-hr field data collections. After a 4-day baseline, Boston participants switched to RIP cigarettes for 14 days, whereas Buffalo participants smoked RIP cigarettes throughout. Outcome measures included cigarettes smoked per day; smoking topography; salivary cotinine; breath CO; and hydroxylated metabolites of pyrene, naphthalene, phenanthrene, and fluorene. Because the groups differed demographically, analyses adjusted for race, age, and sex. Results: We observed no significant changes in smoking topography or CO exposure among participants who switched to RIP cigarettes. Cigarette use decreased significantly in the switched group (37.7 cigarettes/48 hr vs. 32.6 cigarettes/48 hr, p = .031), while hydroxyphenanthrenes increased significantly (555 ng/g creatinine vs. 669 ng/g creatinine, p = .007). No other biomarkers were significantly affected. Discussion: Small increases in exposure to phenanthrene among smokers who switched to RIP versions were observed, while other exposures and smoking topography were not significantly affected. Toxicological implications of these findings are unclear. These findings should be weighed against the potential public health benefits of adopting RIP design standards for cigarette products. PMID:20805292

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 (K d app) 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 K d app while no obvious effect was observed at low HA levels; dissolved HA could inhibit phenanthrene sorption on the two sorbents. PMID:25147865

Profile distribution of polycyclic aromatic hydrocarbons in soils of drained peatlands after wildfires (Moscow region, Russia)

NASA Astrophysics Data System (ADS)

Tsibart, Anna; Gennadiev, Alexander; Koshovskii, Timur; Kovach, Roman

2014-05-01

Polycyclic aromatic compounds (PAHs) are formed in different natural and anthropogenic processes and could be found in many landscape components. These compounds are carcinogenic and belong to the group of persistent organic pollutants. The anthropogenic sources of PAHs are well-studied, but insufficient data are available on the hightemperature production of PAHs in natural processes. For example, natural fires are frequently related to the PAHs sources in landscapes, but very little factual data are on this topic. The soils of drained peatlands affected by catastrophic wildfires of 2010 and 2002 were studied in the Eastern part of Moscow Region (Russia). A total of 14 profiles of histosols and histic podsols were investigated. These series included soils of plots subjected to fires of different intensities and age, as well as soils of the background plots. Soil samples were taken from genetic horizons and from every 10 cm. The samples were analyzed for the contents of 14 prevailing individual compounds: fluorene, naphthalene, phenanthrene, chrysene, pyrene, anthracene, tetraphene, benz[a]pyrene, benzo[ghi]perylene, benzo[e]pyrene, coronene, dibenztiophene, triphenilene, benz(k)fluorantene. Morfological properties of soils after wildfires on drained peatlands were changed dramatically, the horizons of ash and char instead of organic layers were formed. These new horizons differ in the capability of PAHs accumulation. The char horizons have the highest concentrations of PAHs - up to 300 ng/g because of incomplete burning of organic matter in this sites, and the ash horizons, where the complete burning occured, contain only 10 ng/g PAHs. The highest concentrations of PAHs in soil profiles were detected after recent fires, and in cases of thick peat layers. After the combustion of peat chrysene, benz[a]pyrene, benz[e]pyrene, benzo[ghi]perylene, benz(k)fluorantene and tetraphene accumulated in soils. This is mainly the group of 4-6-nuclear compounds. The formation of high-molecular weight compounds is possible during smoldering process under a low oxygen supply. The oxygen deficit acts as a factor of the organic fragments recombination and PAHs production; therefore, relatively large amounts of PAHs are formed in peat fires. Moreover the peat fires occur directly in the soil layer; therefore, larger amounts of the resulting PAHs remain in the soils of the fire sites. The migration of low-molecular weight compounds occures in histic podsols, in histosols PAHs accumalate only in upper organic horizons. The research was conducted with the support of Russian Geographical Society.

[Laser Induced Fluorescence Spectroscopic Analysis of Aromatics from One Ring to Four Rings].

PubMed

Zhang, Peng; Liu, Hai-feng; Yue, Zong-yu; Chen, Bei-ling; Yao, Ming-fa

2015-06-01

In order to distinguish small aromatics preferably, a Nd : YAG Laser was used to supply an excitation laser, which was adjusted to 0.085 J x cm(-2) at 266 nm. Benzene, toluene, naphthalene, phenanthrene, anthracene, pyrene and chrysene were used as the representative of different rings aromatics. The fluorescence emission spectra were researched for each aromatic hydrocarbon and mixtures by Laser induced fluorescence (LIF). Results showed that the rings number determined the fluorescence emission spectra, and the structure with same rings number did not affect the emission fluorescence spectrum ranges. This was due to the fact that the absorption efficiency difference at 266 nm resulted in that the fluorescence intensities of each aromatic hydrocarbon with same rings number were different and the fluorescence intensities difference were more apparently with aromatic ring number increasing. When the absorption efficiency was similar at 266 nm and the concentrations of each aromatic hydrocarbon were same, the fluorescence intensities were increased with aromatic ring number increasing. With aromatic ring number increasing, the fluorescence spectrum and emission peak wavelength were all red-shifted from ultraviolet to visible and the fluorescence spectrum range was also wider as the absorption efficiency was similar. The fluorescence emission spectra from one to four rings could be discriminated in the following wavelengths, 275 to 320 nm, 320 to 375 nm, 375 to 425 nm, 425 to 556 nm, respectively. It can be used for distinguish the type of the polycyclic aromatic hydrocarbons (PAHs) as it exists in single type. As PAHs are usually exist in a variety of different rings number at the same time, the results for each aromatic hydrocarbon may not apply to the aromatic hydrocarbon mixtures. For the aromatic hydrocarbon mixtures, results showed that the one- or two-ring PAHs in mixtures could not be detected by fluorescence as three- or four-ring PAHs existed in mixture. This was caused by radiation energy transfer mechanism, in which the ultraviolet light was lost in mixtures but the fluorescence intensities were increased with the one- or two-ring PAHs adding. When the mixture only contained three- and four-ring PAHs, the fluorescence emission spectrum showed the both characteristics of three- and four-ring PAHs fluorescence. When three- and four-ring PAHs existed in mixtures at the same time, the fluorescence emission spectra were related to each concentration, so the rings number could be discriminated to a certain extent.

Determination of phenanthrene bioavailability by using a self-dying reporter bacterium: test with model solids and soil.

PubMed

Shin, Doyun; Nam, Kyoungphile

2012-02-20

The present study was conducted to investigate the performance and feasibility of a self-dying reporter bacterium to visualize and quantify phenanthrene bioavailability in soil. The self-dying reporter bacterium was designed to die on the initiation of phenanthrene biodegradation. The viability of the reporter bacterium was determined by a fluorescence live/dead cell staining method and visualized by confocal laser scanning microscopic observation. Phenanthrene was spiked into four types of model solids and a sandy loam. The bioavailability of phenanthrene to the reporter bacterium was remarkably declined with the hydrophobicity of the model solids: essentially no phenanthrene was biodegraded in the presence of 9-nm pores and about 35.8% of initial phenanthrene was biodegraded without pores. Decrease in bioavailability was not evident in the nonporous hydrophilic bead, but a small decrease was observed in the porous hydrophilic bead at 1000 mg/kg of phenanthrene. The fluorescence intensity was commensurate with the extent of phenanthrene biodegradation by the reporter bacterium at the concentration range from 50 to 500 mg/kg. Such a quantitative relationship was also confirmed with a sandy loam spiked up to 1000 mg/kg of phenanthrene. This reporter bacterium may be a useful means to determine phenanthrene bioavailability in soil. Copyright © 2011 Elsevier B.V. All rights reserved.

The mechanisms by which phenanthrene affects the photosynthetic apparatus of cucumber leaves.

PubMed

Jin, Liqiao; Che, Xingkai; Zhang, Zishan; Li, Yuting; Gao, Huiyuan; Zhao, Shijie

2017-02-01

Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) that is widely distributed in the environment and seriously affects the growth and development of plants. To clarify the mechanisms of the direct effects of phenanthrene on the plant photosynthetic apparatus, we measured short-term phenanthrene-treated cucumber leaves. Phenanthrene inhibited Rubisco carboxylation activity, decreasing photosynthesis rates (Pn). And phenanthrene inhibited photosystem II (PSII) activity, thereby blocking photosynthetic electron transport. The inhibition of the light and dark reactions decreased the photosynthetic electron transport rate (ETR) and increased the excitation pressure (1-qP). Under high light, the maximum photochemical efficiency of photosystem II (F v /F m ) in phenanthrene-treated cucumber leaves decreased significantly, but photosystem I (PSI) activity (Δ I/I o ) did not. Phenanthrene also caused a J-point rise in the OJIP curve under high light, which indicated that the acceptor side of PSII Q A to Q B electron transfer was restricted. This was primarily due to the net degradation of D1 protein, which is caused by the accumulation of reactive oxygen species (ROS) in phenanthrene-treated cucumber leaves under high light. This study demonstrated that phenanthrene could directly inhibit photosynthetic electron transport and Rubisco carboxylation activity to decrease net Pn. Under high light, phenanthrene caused the accumulation of ROS, resulting in net increases in D1 protein degradation and consequently causing PSII photoinhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantity and quality of stormwater collected from selected stormwater outfalls at industrial sites, Fort Gordon, Georgia, 2011

USGS Publications Warehouse

Nagle, Doug D.; Guimaraes, Wladmir B.

2012-01-01

An assessment of the quantity and quality of stormwater runoff associated with industrial activities at Fort Gordon was conducted from January through December 2011. The assessment was provided to satisfy the requirements from a general permit that authorizes the discharge of stormwater under the National Pollutant Discharge Elimination System from a site associated with industrial activities. The stormwater quantity refers to the runoff discharge at the point and time of the runoff sampling. The study was conducted by the U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon. The initial scope of this study was to sample stormwater runoff from five stations at four industrial sites (two landfills and two heating and cooling sites). As a consequence of inadequate hydrologic conditions during 2011, no samples were collected at the two landfills; however, three samples were collected from the heating and cooling sites. The assessment included the collection of physical properties, such as water temperature, specific conductance, dissolved oxygen, and pH; the detection of suspended materials (total suspended solids, total fixed solids, total volatile solids), nutrients and organic compounds, and major and trace inorganic compounds (metals); and the detection of volatile and semivolatile organic compounds. Nutrients and organic compounds, major and trace inorganic compounds, and volatile and semivolatile organic compounds were detected above the laboratory reporting levels in all samples collected from the three stations. The detection of volatile and semivolatile organic compounds included anthracene, benzo[a]anthracene, benzo[a]pyrene, benzo[ghi]perylene, cis,1, 2-dichloroethene, dimethyl phthalate, fluoranthene, naphthalene, pyrene, acenaphthylene (station SWR11-3), and di-n-butyl phthalate (station SWR11-4).

Pressurized liquid extraction of diesel and air particulate standard reference materials: effect of extraction temperature and pressure.

PubMed

Schantz, Michele M; McGaw, Elizabeth; Wise, Stephen A

2012-10-02

Four particulate matter Standard Reference Materials (SRMs) available from the National Institute of Standards and Technology (NIST) were used to evaluate the effect of solvent, number of static cycles and static times, pressure, and temperature when using pressurized liquid extraction (PLE) for the extraction of polycyclic aromatic hydrocarbons (PAHs) and nitrated-PAHs. The four materials used in the study were SRM 1648a Urban Particulate Matter, SRM 1649b Urban Dust, SRM 1650b Diesel Particulate Matter, and SRM 2975 Diesel Particulate Matter (Industrial Forklift). The results from the study indicate that the choice of solvent, dichloromethane compared to toluene and toluene/methanol mixtures, had little effect on the extraction efficiency. With three to five extraction cycles, increasing the extraction time for each cycle from 5 to 30 min had no significant effect on the extraction efficiency. The differences in extraction efficiency were not significant (with over 95% of the differences being <10%) when the pressure was increased from 13.8 to 20.7 MPa. The largest increase in extraction efficiency occurred for selected PAHs when the temperature of extraction was increased from 100 to 200 °C. At 200 °C naphthalene, biphenyl, fluorene, dibenzothiophene, and anthracene show substantially higher mass fractions (>30%) than when extracted at 100 °C in all the SRMs studied. For SRM 2975, large increases (>100%) are also observed for some other PAHs including benz[a]anthracene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, benzo[ghi]perylene, and benzo[b]chrysene when extracted at the higher temperatures; however, similar trends were not observed for the other diesel particulate sample, SRM 1650b. The results are discussed in relation to the use of the SRMs for evaluating analytical methods.

Purification and characteristics of an inducible by polycyclic aromatic hydrocarbons NADP(+)-dependent naphthalenediol dehydrogenase (NDD) in Mucor circinelloides YR-1.

PubMed

Camacho-Morales, Reyna Lucero; Zazueta-Novoa, Vanesa; Casillas, Juana Lizbeth González; Ballesteros, Elizabeth Aranda; Bote, Juan Antonio Ocampo; Zazueta-Sandoval, Roberto

2014-05-01

We detected NADP(+)-dependent dihydrodiol dehydrogenase (DD) activity in a cell-free extract from Mucor circinelloides YR-1, after high-speed centrifugation. We analyzed the enzymatic activity in the cytosolic fraction by zymograms, as described previously, and eight different DD activity bands were revealed. Five constitutive DD activities (DD1-5) were present when glucose was used as carbon source and three inducible activities (NDD, PDD1 and PDD2) when aromatic hydrocarbon compounds were used. NDD activity was induced all of the aromatic hydrocarbon compounds. The highest DD activity inducer was naphthalene and the lowest was pyrene. One of the enzymes showed higher activity with cis-naphthalene-diol rather than with trans-nahthalenediol as a substrate. We purified this particular enzyme to homogeneity and found that it had an isoelectric point of 4.6. The molecular weight for the native protein was 197.4kDa and 49.03±0.5kDa for the monomer that conforms it, suggesting a homotetrameric structure for the complete enzyme. Polyclonal antibodies were raised against it and obtained. NDD activity was almost totally inhibited when antibodies were used at low concentrations, and in native immunoblots only one band, which corresponds to the activity band detected in the zymograms, could be detected. In denaturing PAGE immunoblots only one band was detected. This band corresponds to the purified protein band of 49kDa detected in SDS-PAGE gels. The other two inducible enzymes PDD1 and PDD2 were present only when phenanthrene was used as sole carbon source in the culture media. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluating environmental modeling and sampling data with biomarker data to identify sources and routes of exposure

NASA Astrophysics Data System (ADS)

Shin, Hyeong-Moo; McKone, Thomas E.; Bennett, Deborah H.

2013-04-01

Exposure to environmental chemicals results from multiple sources, environmental media, and exposure routes. Ideally, modeled exposures should be compared to biomonitoring data. This study compares the magnitude and variation of modeled polycyclic aromatic hydrocarbons (PAHs) exposures resulting from emissions to outdoor and indoor air and estimated exposure inferred from biomarker levels. Outdoor emissions result in both inhalation and food-based exposures. We modeled PAH intake doses using U.S. EPA's 2002 National Air Toxics Assessment (NATA) county-level emissions data for outdoor inhalation, the CalTOX model for food ingestion (based on NATA emissions), and indoor air concentrations from field studies for indoor inhalation. We then compared the modeled intake with the measured urine levels of hydroxy-PAH metabolites from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) survey as quantifiable human intake of PAH parent-compounds. Lognormal probability plots of modeled intakes and estimated intakes inferred from biomarkers suggest that a primary route of exposure to naphthalene, fluorene, and phenanthrene for the U.S. population is likely inhalation from indoor sources. For benzo(a)pyrene, the predominant exposure route is likely from food ingestion resulting from multi-pathway transport and bioaccumulation due to outdoor emissions. Multiple routes of exposure are important for pyrene. We also considered the sensitivity of the predicted exposure to the proportion of the total naphthalene production volume emitted to the indoor environment. The comparison of PAH biomarkers with exposure variability estimated from models and sample data for various exposure pathways supports that both indoor and outdoor models are needed to capture the sources and routes of exposure to environmental contaminants.

Leaching behaviour of low level organic pollutants contained in cement-based materials: experimental methodology and modelling approach.

PubMed

Tiruta-Barna, Ligia; Fantozzi-Merle, Catherine; de Brauer, Christine; Barna, Radu

2006-11-16

The aim of this paper is the investigation of the leaching behaviour of different porous materials containing organic pollutants (PAH: naphthalene and phenanthrene). The assessment methodology of long term leaching behaviour of inorganic materials was extended to cement solidified organic pollutants. Based on a scenario-approach considering environmental factors, matrix and pollutants specificities, the applied methodology is composed of adapted equilibrium and dynamic leaching tests. The contributions of different physical and chemical mechanisms were identified and the leaching behaviour was modelled. The physical parameters of the analysed reference and polluted materials are similar. A difference in the pore size distribution appears for higher naphthalene content. The solubility of the PAH contained in the material is affected by the ionic strength and by the presence of a co-solvent; the solution pH does not influence PAH solubility. The solubility of the major mineral species is not influenced by the presence of the two PAH nor by the presence of the methanol as co-solvent in the range of the tested material compositions. In the case of the leaching of a monolith material the main transport mechanism is the diffusion in the porous system. For both mineral and organic species we observed at least two dynamic domains. At the beginning of the leaching process the released flux is due to the surface dissolution and to the diffusion of the main quantity dissolved in the initial pore solution. The second period is governed by a stationary regime between dissolution in pore water and diffusion. The model, coupling transport and chemical phenomena in the pore solution, at the monolith surface and in the leachate simulates satisfactory the release for both mineral and organic species.

Thermodynamics of phenanthrene partition into solid organic matter from water.

PubMed

Chen, Bao-liang; Zhu, Li-zhong; Tao, Shu

2005-01-01

The thermodynamic behavior of organic contaminants in soils is essential to develop remediation technologies and assess risk from alternative technologies. Thermodynamics of phenanthrene partition into four solids(three soils and a bentonite) from water were investigated. The thermodynamics parameters (deltaH, deltaG degrees, deltaS degrees) were calculated according to experimental data. The total sorption heats of phenanthrene to solids from water ranged from -7.93 to -17.1 kJ/mol, which were less exothermic than the condensation heat of phenanthrene-solid (i.e., -18.6 kJ/mol). The partition heats of phenanthrene dissolved into solid organic matter ranged from 23.1 to 32.2 kJ/mol, which were less endothermic than the aqueous dissolved heat of phenanthrene (i.e., 40.2 kJ/mol), and were more endothermic than the fusion heat of phenanthrene-solid (i.e., 18.6 kJ/mol). The standard free energy changes, deltaG degrees, are all negative which suggested that phenanthrene sorption into solid was a spontaneous process. The positive values of standard entropy changes, deltaS degrees, show a gain in entropy for the transfer of phenanthrene at the stated standard state. Due to solubility-enhancement of phenanthrene, the partition coefficients normalized by organic carbon contents decrease with increasing system temperature (i.e., ln Koc = -0.284 ln S + 9.82 (n = 4, r2 = 0.992)). The solubility of phenanthrene in solid organic matter increased with increasing temperatures. Transports of phenanthrene in different latitude locations and seasons would be predicted according to its sorption thermodynamics behavior.

Impact of methylene chloride on microorganisms and phenanthrene mineralization in soil.

PubMed

Schwartz, Egbert; Trinh, Sinh V; Scow, Kate M

2002-01-01

This study investigated the effects of the quantity of methylene chloride, used as a carrier solvent for phenanthrene when added to soil, on phenanthrene mineralization kinetics, soil phospholipid fatty add profiles (PLFA), and phenanthrene distribution. Methylene chloride dosages of 25 microL/g soil or more resulted in an enrichment of saturated PLFAs, suggesting soil microorganisms had adjusted their cell membranes in response to the solvent. A greater fraction of phenanthrene mineralized when spiked in 5 microL/g than in 25 microL/g methylene chloride suggesting that the methylene chloride became toxic to phenanthrene-degrading organisms in soil. Phenanthrene was more equally distributed among 0.1 g soil subsamples if spiked in 25 than 5 or 1 microL methylene chloride per gram soil. Thus the amount of methylene chloride used to spike phenanthrene in soil strongly impacted the mineralization kinetics, phenanthrene distribution, and microbial community in soil. Because a variety of spiking methods are used in biodegradation research, scientists should consider the quantity of solvents used when comparing results among different studies.

Characterization of hydrocarbon-degrading and biosurfactant-producing Pseudomonas sp. P-1 strain as a potential tool for bioremediation of petroleum-contaminated soil.

PubMed

Pacwa-Płociniczak, Magdalena; Płaza, Grażyna Anna; Poliwoda, Anna; Piotrowska-Seget, Zofia

2014-01-01

The Pseudomonas sp. P-1 strain, isolated from heavily petroleum hydrocarbon-contaminated soil, was investigated for its capability to degrade hydrocarbons and produce a biosurfactant. The strain degraded crude oil, fractions A5 and P3 of crude oil, and hexadecane (27, 39, 27 and 13% of hydrocarbons added to culture medium were degraded, respectively) but had no ability to degrade phenanthrene. Additionally, the presence of gene-encoding enzymes responsible for the degradation of alkanes and naphthalene in the genome of the P-1 strain was reported. Positive results of blood agar and methylene blue agar tests, as well as the presence of gene rhl, involved in the biosynthesis of rhamnolipid, confirmed the ability of P-1 for synthesis of glycolipid biosurfactant. 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectrum and mass spectrum analyses indicated that the extracted biosurfactant was affiliated with rhamnolipid. The results of this study indicate that the P-1 and/or biosurfactant produced by this strain have the potential to be used in bioremediation of hydrocarbon-contaminated soils.

Preparation of IrO2-Ta2O5|Ti electrodes by immersion, painting and electrophoretic deposition for the electrochemical removal of hydrocarbons from water.

PubMed

Herrada, Rosa Alhelí; Medel, Alejandro; Manríquez, Federico; Sirés, Ignasi; Bustos, Erika

2016-12-05

After intense years of great development, the electrochemical technologies have become very suitable alternatives in niche markets like industrial wastewater reclamation and soil remediation. A key role to achieve a high efficiency in such treatments is played by the characteristics of the coating of the electrodes employed. This paper compares three techniques, namely immersion, painting and electrophoresis, for the preparation of IrO2-Ta2O5ǀTi, so-called dimensionally stable anodes (DSA(®)). The quality of the coatings has been investigated by means of surface and electrochemical analysis. Their ability to generate hydroxyl radicals and degrade aqueous solutions of hydrocarbons like phenanthrene, naphthalene and fluoranthene has been thoroughly assessed. Among the synthesis techniques, electrophoretic deposition yielded the best results, with DSA(®) electrodes exhibiting a homogeneous surface coverage that led to a good distribution of active sites, thus producing hydroxyl radicals that were able to accelerate the degradation of hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

Predicting bioavailability of PAHs in soils to wheat roots with triolein-embedded cellulose acetate membranes and comparison with chemical extraction.

PubMed

Tao, Yuqiang; Zhang, Shuzhen; Wang, Zijian; Christie, Peter

2008-11-26

Triolein-embedded cellulose acetate membrane (TECAM) was buried in 15 field-contaminated soils in parallel with the cultivation of wheat to predict bioavailability of naphthalene, phenanthrene, pyrene, and benzo[a]pyrene to wheat roots, and the method was compared with chemical extraction methods. Although a good linear relationship was found between PAH concentrations in chemical extractants and wheat roots, the percentage of PAH in soil removed by chemical extraction was much higher than the corresponding percentage removed by wheat roots. In contrast to chemical extraction, a nearly 1:1 relationship was found between the amount of each PAH taken up by TECAMs and wheat roots (r(2) = 0.798-0.925, P < 0.01). Furthermore, the uptake of PAHs by TECAMs and wheat roots had the same pathway of passive transport via the soil solution. Moreover, TECAM caused minimal disturbance to the soil and was easy to deploy. Therefore, TECAM is believed to be a useful tool to predict bioavailability of PAHs to wheat roots grown in contaminated soils.

Solubilization of polycyclic aromatic hydrocarbons in micellar nonionic surfactant solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, D.A.; Luthy, R.G.; Liu, Zhongbao

1991-01-01

Experimental data are presented on the enhanced apparent solubilities of naphthalene, phenanthrene, and pyrene resulting from solubilization in aqueous solutions of four commercial, nonionic surfactants: an alkyl polyoxyethylene (POE) type, two octylphenol POE types, and a nonylphenol POE type. Apparent solubilities of the polycyclic aromatic hydrocarbon (PAH) compounds in surfactant solutions were determined by radiolabeled techniques. Solubilization of each PAH compound commenced at the surfactant critical micelle concentration and was proportional to the concentration of surfactant in micelle form. The partitioning of organic compounds between surfactant micelles and aqueous solution is characterized by a mole fraction micelle-phase/aqueous-phase partition coefficient, K{submore » m}. Values of log K{sub m} for PAH compounds in surfactant solutions of this study range from 4.57 to 6.53. Log K{sub m} appears to be a linear function of log K{sub ow} for a given surfactant solution. A knowledge of partitioning in aqueous surfactant systems is a prerequisite to understanding mechanisms affecting the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in contaminant remediation or facilitated transport.« less

Impacts of Pantoea agglomerans strain and cation-modified clay minerals on the adsorption and biodegradation of phenanthrene.

PubMed

Tao, Kelin; Zhao, Song; Gao, Pin; Wang, Lijin; Jia, Hanzhong

2018-06-06

Interactions between microorganisms and minerals have the potential contribution to remove polycyclic aromatic hydrocarbons (PAHs) in model systems. In this study, phenanthrene (PHE) was used as a probe molecule to explore the potential adsorption and biotransformation processes in the presence of microorganisms and various reference clays, such as montmorillonite (M), kaolinite (K), and pyrophyllite (P). Equilibrium adsorption experiments and scanning electron microscopy (SEM) technique were used to investigate the sorption of Pantoea agglomerans strains on clay minerals saturated with cations (Na + and Fe 3+ ). The adsorption isotherms of PHE and Pantoea agglomerans strains on cation-modified clay minerals fitted to Langmuir equation, and their adsorbed amounts both followed the sequence: montmorillonite > kaolinite > pyrophyllite. For six types of cation-modified minerals, the behavior of PHE adsorbed and Pantoea agglomerans adhered onto mentioned minerals was in the order of Na(I)-M > Fe(Ⅲ)-M, Na(I)-K > Fe(Ⅲ)-K and Fe(Ⅲ)-P > Na(I)-P, respectively. The biodegradation results showed that cation-modified clay minerals could enhance the biodegradation of PHE, ascribing to their large specific surface area, and cation exchange capability, as well as the difference in zeta potential between minerals and Pantoea agglomerans strains. Comparison of biodegradation rates displayed that PHE was degraded the highest in the presence of Na-M (93.285%). In addition, the obtained results suggested that the adhesion of bacteria onto cation-exchanged clay minerals was beneficial to the biodegradation of PHE. Anthracen-9-ylmethanol and 3,4-dimethyl-2-(3-methylbutanoyl)benzoic acid were detected as the main intermediate compounds, which can be further biodegraded into small molecules. The overall results obtained in this study are of valuable significance for the understanding of the behavior of PHE in soil and associated environment. Copyright © 2018 Elsevier Inc. All rights reserved.

Spatial distribution and temporal trends of polycyclic aromatic hydrocarbons (PAHs) in water and sediment from Songhua River, China.

PubMed

Zhao, Xuesong; Ding, Jing; You, Hong

2014-02-01

The spatial and temporal distributions of polycyclic aromatic hydrocarbons (PAHs) in the Songhua River, Harbin, China, were investigated. Seventy-seven samples, 42 water and 35 sediment samples, were collected in April and October of 2007 and January of 2008. The concentrations of total PAHs in water ranged from 163.54 to 2,746.25 ng/L with the average value of 934.62 ng/L, which were predominated by 2- and 3-ring PAHs. The concentrations of total 16 PAHs in sediment ranged from 68.25 to 654.15 ng/g dw with the average value of 234.15 ng/g dw, which were predominated by 4-, 5- and 6-ring PAHs. Statistical analysis of the PAH concentrations shown that the highest concentrations of the total PAHs were found during rainy season (October of 2007) and the lowest during snowy season (January of 2008). Ratios of specific PAH compounds, including fluoranthene/(fluoranthene + pyrene) (Flu/(Flu + Pyr)) and phenanthrene/(phenanthrene + anthracene) (An/(Ant + PhA)), were calculated to evaluate the possible sources of PAH contaminations. These ratios reflected pyrolytic inputs of PAHs in Songhua River water and a mixed pattern of pyrolytic and petrogenic inputs of PAHs in the Songhua River sediments. Ecotoxicological risk levels calculated for PAHs suggested that there were individual PAHs, which can less frequently cause biological impairment in some samples, but no samples had constituents that may frequently cause biological impairment. Total toxic benzo[a]pyrene equivalent of ΣcPAHs varied from 10.03 to 29.7 ng/g dw and from 0.36 to 1.92 ng/g dw for total toxic tetrachlorodibenzo-p-dioxin equivalent. The level of PAHs indicated a low toxicological risk to this area.

Spatial and temporal variation of freely dissolved polycyclic aromatic hydrocarbons in an urban river undergoing Superfund remediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aregory James Sower; Kim A. Anderson

2008-12-15

Urban rivers with a history of industrial use can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations and even the assessment of remediation efforts. Concentrations of 15 biologically available priority pollutant polycyclic aromatic hydrocarbons (PAHs) were measured over five years along 18.5 miles of the lower Willamette River using passive sampling devices and HPLC. The study area includes the Portland Harbor Superfund megasite with several PAH sources including remediation operations for coal tar at RM 6.3 west and an additional Superfund site, McCormick and Baxter, at RM 7 east consisting largely of creosote contamination.more » Study results show that organoclay capping at the McCormick and Baxter Superfund Site reduced PAHs from a precap average of 440 {+-} 422 ng/L to 8 {+-} 3 ng/L postcapping. Results also reveal that dredging of submerged coal tar nearly tripled nearby freely dissolved PAH concentrations. For apportioning sources, fluoranthene/pyrene and phenanthrene/anthracene diagnostic ratios from passive sampling devices were established for creosote and coal tar contamination and compared to published sediment values. 29 refs., 3 figs., 3 tabs.« less

Detection of polycyclic aromatic hydrocarbons (PAHs) in Medicago sativa L. by fluorescence microscopy.

PubMed

Alves, Wilber S; Manoel, Evelin A; Santos, Noemi S; Nunes, Rosane O; Domiciano, Giselli C; Soares, Marcia R

2017-04-01

Green technologies, such as phytoremediation, are effective for removing organic pollutants derived from oil and oil products, including polycyclic aromatic hydrocarbons (PAHs). Given the increasing popularity of these sustainable remediation techniques, methods based on fluorescence microscopy and multiphoton microscopy for the environmental monitoring of such pollutants have emerged in recent decades as effective tools for phytoremediation studies aimed at understanding the fate of these contaminants in plants. However, little is known about the cellular and molecular mechanisms involved in PAH uptake, responses and degradation by plants. Thus, the present study aimed to detect the location of pyrene, anthracene and phenanthrene using fluorescence microscopy techniques in shoots and roots of Medicago sativa L. (alfalfa) plants grown in artificially contaminated soil (150ppm PAHs) for 40days. Leaflet and root samples were then collected and observed under a fluorescence microscope to detect the presence of PAHs in various tissues. One important finding of the present study was intense fluorescence in the glandular secreting trichomes (GSTs) of plants grown in contaminated soil. These trichomes, with a previously unknown function, may be sites of PAH conjugation and degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fate and Transport of Polycyclic Aromatic Hydrocarbons in Upland Irish Headwater Lake Catchments

PubMed Central

Scott, Heidi E. M.; Aherne, Julian; Metcalfe, Chris D.

2012-01-01

Polycyclic aromatic hydrocarbons (PAHs) are a concern due to their carcinogenicity and propensity for transboundary atmospheric transport. Ireland is located on the western periphery of Europe and assumed to receive clean Atlantic air. As such, it has been used as an atmospheric reference for comparison to other regions. Nonetheless, few studies have evaluated concentrations of PAHs within the Irish environment. In the current study, PAHs were measured at five upland (500–800 masl) headwater lake catchments in coastal regions around Ireland, remote from industrial point source emissions. Semipermeable membrane devices were deployed in lakes for a 6-month period in July 2009, and topsoils were sampled from each catchment during October 2010. The concentrations of PAHs were low at most study sites with respect to other temperate regions. Homologue groups partitioned between lake and soil compartments based on their molecular weight were: “lighter” substances, such as Phenanthrene and Fluorene, were found in higher proportions in lakes, whereas “heavier” compounds, such as Chrysene and Benz[a]anthracene, were more prominent in soils. Concentrations of PAHs were highest at the east coast sites, potentially due to contributions from historical transboundary and regional combustion sources. PMID:23346024

Selectivity of hexaphenylbenzene-based hydrocarbon stationary phase with propeller-like conformation for aromatic and aliphatic isomers.

PubMed

Yang, Yinhui; Chang, Zhengfeng; Yang, Xiaohong; Qi, Meiling; Wang, Jinliang

2018-08-03

Herein we report a propeller-like hexaphenylbenzene-based hydrocarbon material (denoted as BT) as the stationary phase for capillary gas chromatography (GC). The statically-coated BT capillary column showed a high column efficiency of 4340 plates m -1 and weak polarity. Owing to its unique conformation, π-electron toroidal delocalization and intrinsic microporosity, the BT stationary phase exhibited interesting selectivity for aromatic compounds over alkanes. Compared with the graphene (G) column, the BT column showed much prolonged retention and high selectivity for aromatic isomers, especially methylnaphthalenes, dimethylnaphthalenes and phenanthrene/anthracene, mainly because of its propeller-like conformation with rich intercalation effects. Moreover, it exhibited good column repeatability (intra-day, inter-day) and reproducibility (between-column) with RSD values on the retention times less than 0.08% for intra-day, 0.32% for inter-day and 3.8% for between-column, respectively. Also, it showed good potential for determination of minor isomer impurities in real samples. To the best of our knowledge, this work presents the first example of employing an neat aromatic hydrocarbon material as the GC stationary phase with high selectivity for analytes of a wide ranging polarity. Copyright © 2018 Elsevier B.V. All rights reserved.

Remediation of soil-bound polynuclear aromatic hydrocarbons using nonionic surfactants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeom, IckTae; Ghosh, Mriganka; Cox, C.

1996-12-31

The solubilization and biodegradation of soil-bound PAHs from a manufactured gas plant (MGP) site soil was investigated using surfactants. Three nonionic polyoxyethylene (POE) surfactants, Triton X-100, Tween 80, and Brij 35, were used. The fate of four PAHs, phenanthrene, anthracene, pyrene, and benzo(a)pyrene were monitored during the remediation process. The measured concentrations of solubilized PAHs agreed well with those estimated using micelle-water partitioning coefficient, K{sub m}, and Raoult`s law. The solubilization of soil-bound PAHs by surfactants is a slow, nonequilibrium process. Diffusion of PAH molecules within the weathered soil-tar matrix is proposed as the rate-limiting step in solubilizing PAHs frommore » such soils. A radial diffusion model is used to describe solubilization of PAHs by surfactant washing. The model predicts experimental results fairly well at low surfactant dosages while at high dosages it somewhat overestimates the extent of solubilization. Biodegradation studies were performed using a natural consortium of microorganisms enriched from PAH-contaminated soils. Surfactants enhanced biodegradation of PAHs except for Tween 80. However, biodegradation of surfactants themselves appear to attenuate the beneficial effects of surfactant-mediated bioremediation.« less

PAH dissipation in spiked soil: impacts of bioavailability, microbial activity, and trees.

PubMed

Mueller, Kevin E; Shann, Jodi R

2006-08-01

While trees have demonstrated potential in phytoremediation of several organic contaminants, little is known regarding their ability to impact the common soil contaminant PAHs. Several species of native North American trees were planted in soil artificially contaminated with three PAHs. Plant biomass, PAH dissipation, and microbial mineralization were monitored over the course of one year and environmental conditions were allowed to follow typical seasonal patterns. PAH dissipation and mineralization were not affected by planting. Extensive and rapid loss of PAHs was observed and attributed to high bioavailability and microbial activity in all treatments. The rate of this loss may have masked any significant planting effects. Anthracene was found to be more recalcitrant than pyrene or phenanthrene. Parallel soil aging studies indicated that sequestration to soil components was minimal. Contrary to common inferences in literature, amendment with decaying fine roots inhibited PAH degradation by the soil microbial community. Seasonal variation in environmental factors and rhizosphere dynamics may have also reduced or negated the effect of planting and should be taken into account in future phytoremediation trials. The unique root traits of trees may pose a challenge to traditional thought regarding PAH dissipation in the rhizosphere of plants.

Degradation of polycyclic aromatic hydrocarbons (PAHs) present in used motor oil and implications for urban runoff quality

NASA Astrophysics Data System (ADS)

Ferreira, M.; Stenstrom, M. K.; Lau, S.

2013-12-01

Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants of urban stormwater runoff due to atmospheric deposition, vehicle-related discharges, and coal tar pavement sealants. The US EPA lists sixteen PAHs as priority pollutants and seven of those are potential carcinogenic compounds. Due to their molecular structure, PAHs tend to attach to particles that will subsequently be deposited as sediments in waterways. This study focuses on the degradation of PAHs present in used motor oil. Four experimental setups were used to simulate volatilization and photooxidation in the degradation of sixteen PAHs as observed for up to 54 days. The volatilization-only experiment showed substantial reduction only in the concentration of Napthalene (Nap). However, photooxidation-only was more efficient in degrading PAHs. In this process, substantial reduction in the concentrations of Nap, Acenapthene (Anthe), Anthracene (ANT), Fluoranthene (FLT), Pyrene (PYR), Benz[a]anthracene (BaA), Benzo[a]pyrene (BaP), Indeno[1,2,3,cd]pyrene (INP), and Benz[g,h,i]perylene (BghiP) were observed as early as five days. The two volatilization-photooxidation experiments exhibited substantial reduction in the concentrations of Fluorene (FLU), Chrysene (CHR) and Benzo[b]fluoranthene (BbF), in addition to the PAHs reduced by photooxidation-only. Phenanthrene (PHE), Fluoranthene (FLT), and Benzo[b]fluoranthene (BbF) only exhibited substantial decreased concentrations after 20 days in the volatilization-photooxidation experiment. One PAH, acenapthylene (Anthy), was not detected in the original sample of used motor oil. The highest degradations were observed in the combined volatilization-photooxidation experiment. In regions with infrequent rainfall, such as Southern California, molecules of PAHs attached to highway particles will have time to undergo degradation prior to transport. Therefore, PAHs may be present in lower concentrations in highway runoff in dry climates than in rainy climates. To support this hypothesis, a review of highway-related PAHs concentrations is presented.

Numerical taxonomy of phenanthrene-degrading bacteria isolated from the Chesapeake Bay

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, P.A.; Okpokwasili, G.C.; Brayton, P.R.

1984-11-01

Phenanthrene-degrading bacteria were isolated from Chesapeake Bay samples by the use of a solid medium which had been overlaid with an ethanol solution of phenanthrene before inoculation. Eighteen representative strains of phenanthrene-degrading bacteria with 21 type and reference bacteria were examined for 123 characteristics representing physiological, biochemical, and nutritional properties. Relationships between strains were computed with several similarity coefficients. The phenogram constructed by unweighted-pair-group arithmetic average linkage and use of the simple Jaccard (S/sub J/) coefficient was used to identify seven phena. Phenanthrene-degrading bacteria were identified as Vibrio parahaemolyticus and Vibrio fluvialis by their clustering with type and reference strains.more » Several phenanthrene-degrading bacteria resembled Enterobacteriaceae family members, although some Vibrio-like phenanthrene degraders could not be identified. 22 references, 1 figure, 2 tables.« less

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.

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

Isolation of Soil Bacteria Adapted To Degrade Humic Acid-Sorbed Phenanthrene

PubMed Central

Vacca, D. J.; Bleam, W. F.; Hickey, W. J.

2005-01-01

The goal of these studies was to determine how sorption by humic acids affected the bioavailability of polynuclear aromatic hydrocarbons (PAHs) to PAH-degrading microbes. Micellar solutions of humic acid were used as sorbents, and phenanthrene was used as a model PAH. Enrichments from PAH-contaminated soils established with nonsorbed phenanthrene yielded a total of 25 different isolates representing a diversity of bacterial phylotypes. In contrast, only three strains of Burkholderia spp. and one strain each of Delftia sp. and Sphingomonas sp. were isolated from enrichments with humic acid-sorbed phenanthrene (HASP). Using [14C]phenanthrene as a radiotracer, we verified that only HASP isolates were capable of mineralizing HASP, a phenotype hence termed “competence.” Competence was an all-or-nothing phenotype: noncompetent strains showed no detectable phenanthrene mineralization in HASP cultures, but levels of phenanthrene mineralization effected by competent strains in HASP and NSP cultures were not significantly different. Levels and rates of phenanthrene mineralization exceeded those predicted to be supported solely by the metabolism of phenanthrene in the aqueous phase of HASP cultures. Thus, competent strains were able to directly access phenanthrene sorbed by the humic acids and did not rely on desorption for substrate uptake. To the best of our knowledge, this is the first report of (i) a selective interaction between aerobic bacteria and humic acid molecules and (ii) differential bioavailability to bacteria of PAHs sorbed to a natural biogeopolymer. PMID:16000791

Uptake of aromatic hydrocarbon vapors (benzene and phenanthrene) at the air-water interface of micron-size water droplets.

PubMed

Raja, Suresh; Valsaraj, Kalliat T

2004-12-01

Uptake of aromatic hydrocarbon vapors (benzene and phenanthrene) by typical micrometer-sized fog-water droplets was studied using a falling droplet reactor at temperatures between 296 and 316 K. Uptake of phenanthrene vapor greater than that predicted by bulk (air-water)-phase equilibrium was observed for diameters less than 200 microm, and this was attributed to surface adsorption. The experimental values of the droplet-vapor partition constant were used to obtain the overall mass transfer coefficient and the mass accommodation coefficient for both benzene and phenanthrene. Mass transfer of phenanthrene was dependent only on gas-phase diffusion and mass accommodation at the interface. However, for benzene, the mass transfer was limited by liquid-phase diffusion and mass accommodation. A large value of the mass accommodation coefficient, alpha = (1.4 +/- 0.4) x 10(-2) was observed for the highly surface-active (hydrophobic) phenanthrene, whereas a small alpha = (9.7 +/- 1.8) x 10(-5) was observed for the less hydrophobic benzene. Critical cluster numbers ranging from 2 for benzene to 5.7 for phenanthrene were deduced using the critical cluster nucleation theory for mass accommodation. The enthalpy of mass accommodation was more negative for phenanthrene than it was for benzene. Consequently, the temperature effect was more pronounced for phenanthrene. A linear correlation was observed for the enthalpy of accommodation with the excess enthalpy of solution. A natural organic carbon surrogate (Suwannee Fulvic acid) in the water droplet increased the uptake for phenanthrene and benzene, the effect being more marked for phenanthrene. A characteristic time constant analysis showed that uptake and droplet scavenging would compete for the fog deposition of phenanthrene, whereas deposition would be unimpeded by the uptake rate for benzene vapor. For both compounds, the characteristic atmospheric reaction times were much larger and would not impact fog deposition.

Effects of flooding and aging on phytoremediation of typical polycyclic aromatic hydrocarbons in mangrove sediments by Kandelia obovata seedlings.

PubMed

Li, Rui-Long; Liu, Bei-Bei; Zhu, Ya-Xian; Zhang, Yong

2016-06-01

A laboratory experiment was conducted to evaluate the effects of flooding and aging on the phytoremediation of naphthalene (Nap), anthracene (Ant) and benzo[a]pyrene (B[a]P) in mangrove sediment by Kandelia obovata (K. obovata) Druce seedlings. Flooding increased dissipation efficiency in the rhizosphere zone from 69.47% to 82.45%, 64.27% to 80.41%, and 61.55% to 78.31% for Nap, Ant and B[a]P, respectively. Aging decreased dissipation efficiency significantly. Further investigation demonstrated that increased enzyme activity was one of important factors for increasing PAHs dissipation rates in flooded mangrove sediments. Moreover, a novel method for in situ quantitative investigation of PAHs distribution in root tissues was established using microscopic fluorescence spectra analysis. Subsequently, the effects of flooding and aging on the distribution of PAHs in root tissues were evaluated using this established method. The order of bioavailable fractions of PAHs after phytoremediation was as follows: non-aging/non-flooding>flooding>aging. Copyright © 2016 Elsevier Inc. All rights reserved.

Determination of polycyclic aromatic hydrocarbons in drinking water samples by solid-phase nanoextraction and high-performance liquid chromatography.

PubMed

Wang, Huiyong; Campiglia, Andres D

2008-11-01

A novel alternative is presented for the extraction and preconcentration of polycyclic aromatic hydrocarbons (PAH) from water samples. The new approachwhich we have named solid-phase nanoextraction (SPNE)takes advantage of the strong affinity that exists between PAH and gold nanoparticles. Carefully optimization of experimental parameters has led to a high-performance liquid chromatography method with excellent analytical figures of merit. Its most striking feature correlates to the small volume of water sample (500 microL) for complete PAH analyses. The limits of detection ranged from 0.9 (anthracene) to 58 ng.L (-1) (fluorene). The relative standard deviations at medium calibration concentrations vary from 3.2 (acenaphthene) to 9.1% (naphthalene). The analytical recoveries from tap water samples of the six regulated PAH varied from 83.3 +/- 2.4 (benzo[ k]fluoranthene) to 95.7 +/- 4.1% (benzo[ g,h,i]perylene). The entire extraction procedure consumes less than 100 microL of organic solvents per sample, which makes it environmentally friendly. The small volume of extracting solution makes SPNE a relatively inexpensive extraction approach.

High-efficient and brightness white organic light-emitting diodes operated at low bias voltage

NASA Astrophysics Data System (ADS)

Zhang, Lei; Yu, Junsheng; Yuan, Kai; Jian, Yadong

2010-10-01

White organic light-emitting diodes (OLEDs) used for display application and lighting need to possess high efficiency, high brightness, and low driving voltage. In this work, white OLEDs consisted of ambipolar 9,10-bis 2-naphthyl anthracene (ADN) as a host of blue light-emitting layer (EML) doped with tetrabutyleperlene (TBPe) and a thin codoped layer consisted of N, N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) as a host of yellow light-emitting layer doped with 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) were investigated. With appropriate tuning in the film thickness, position, and dopant concentration of the co-doped layer, a white OLED with a luminance yield of 10.02 cd/A with the CIE coordinates of (0.29, 0.33) has been achieved at a bias voltage of 9 V and a luminance level of over 10,000 cd/m2. By introducing the PIN structure with both HIL and bis(10- hydroxybenzo-quinolinato)-beryllium (BeBq2) ETL, the power efficiency of white OLED was improved.

[Priority pollutants ranking and screening of coke industry based on USEtox model].

PubMed

Hao, Tian; Du, Peng-Fei; Du, Bin; Zeng, Si-Yu

2014-01-01

Thesis aims at evaluating and setting priority to human toxicity and ecotoxicity of coking pollutants. A field research and sampling project are conducted in coke plant in Shanxi so as to complete the coke emission inventory. The USEtox model representing recommended practice in LCIA characterization is applied to the emission inventory to quantify the potential impacts on human toxicity and ecotoxicity of emerging pollutants. Priority pollutants, production procedures and effects of changing plant site on the toxicity are analyzed. As conclusions, benzo(a) pyrene, benzene, Zn and As are identified as the priority pollutants in human toxicity, while pyrene and anthracene in ecotoxicity. Coal charging is the dominant procedure for organic toxicity and priority pollutants include benzo (a) pyrene, benzene, naphthalene, etc. While coke drenching is the dominant procedure for metal toxicity and priority pollutants include Zn, As, Ti, Hg etc. Emission to rural environment can reduce the organic toxicity significantly compared to the emission to urban environment. However, the site changing has no effect on metal toxicity and might increase the risk of the metal pollution to rural water and soil.

Probing the (110)-Oriented plane of rutile ZnF2: A DFT investigation

NASA Astrophysics Data System (ADS)

Tamijani, Ali Abbaspour; Ebrahimiaqda, Elham

2017-12-01

For many years, rutile-like crystals have given rise to pronounced enthusiasm amongst mineralogists. In this context, rutile-type ZnF2 has found numerous applications across a variety of disciplines, ranging from material sciences to optoelectronics. Surprisingly, very limited literature is concerned with the molecular adsorption on ZnF2 surfaces and related energetics. Additionally, surface probing with small particles is a well-entrenched technique to analyze the interfacial properties. In this regard, small organic species are valuable picks. In the present work, we have employed electronic structure calculations to simulate the adsorption of methane, chloroform, pyrrole, benzene, naphthalene, anthracene, tetracene and pentacene at the (110) plane of rutile ZnF2. Dispersion-corrected DFT method was chosen to predict the binding energies and structures of molecule-adsorbed surfaces. Interestingly, a linear proportionality relationship was found between the binding energies of aromatic adsorbates and their respective molecular lengths. By applying this relationship, we were able to predict the adsorption energy of pentacene on ZnF2 to within 2% of our DFT-based result.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasnokutski, Serge A.; Huisken, Friedrich; Jäger, Cornelia

A very high abundance of atomic carbon in the interstellar medium (ISM), and the high reactivity of these species toward different hydrocarbon molecules including benzene, raise questions regarding the stability of polycyclic aromatic hydrocarbon (PAH) molecules in space. To test the efficiency of destruction of PAH molecules via reactions with atomic carbon, we performed a set of laboratory and computational studies of the reactions of naphthalene, anthracene, and coronene molecules with carbon atoms in the ground state. The reactions were investigated in liquid helium droplets at T = 0.37 K and by quantum chemical computations. Our studies suggest that allmore » small and all large catacondensed PAHs react barrierlessly with atomic carbon, and therefore should be efficiently destroyed by such reactions in a broad temperature range. At the same time, large compact pericondensed PAHs should be more inert toward such a reaction. In addition, taking into account their higher photostability, much higher abundances of pericondensed PAHs should be expected in various astrophysical environments. The barrierless reactions between carbon atoms and small PAHs also suggest that, in the ISM, these reactions could lead to the bottom-up formation of PAH molecules.« less

Gas-phase reactions of phenyl radicals with aromatic molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fahr, A.; Stein, S.E.

1988-08-25

Relative rates of reactions of phenyl radicals with a series of aromatic and polycyclic aromatic compounds are reported. Most studies were done in static reactors at 450/degrees/C using diphenyl diketone (benzil) as the phenyl radical source. Reactions with the following molecules are reported: benzene, toluene, p-xylene, 1,3,5-trimethylbenzene, phenol, bromobenzene, naphthalene, biphenyl, anthracene, 9-methylanthracene, and triphenylene. For reactions with substituted benzenes, H abstraction is the dominant reaction. Relative rates of phenylation at different sites do not closely follow established trends for rates of radical attack. It is proposed that these deviations are primarily due to a dependence of the degree ofmore » reversibility on the specific site of phenylation. These studies also show that the rates of phenyl and H-atom migration around the ring in adduct radicals are slow relative to dissociation. Also, by use of these results to link literature rate data from high and low temperatures, a rate expression for H abstraction from p-xylene by phenyl of 10/sup 9.6/ exp(-4.4 kcal/RT) M/sup /minus/1/ s/sup /minus/1/ is derived.« less

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.

Effect of aging of chemicals in soil on their biodegradability and extractability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatzinger, P.B.; Alexander, M.

1995-11-01

A study was conducted to determine whether the time that a compound remains in a soil affects its biodegradability and the ease of its extraction. Phenanthrene and 4-nitrophenol were aged in sterilized loam and muck, and bacteria able to degrade the compounds were then added to the soils. increasingly smaller amounts of phenanthrene in the muck and 4-nitrophenol in both soils were mineralized with increasing duration of aging. Aging also increased the resistance of phenanthrene to biodegradation in nutrient-amended aquifer sand. The rate of miner- alization of the two compounds in both soils declined with increasing periods of aging. Themore » amount of phenanthrene and 4-nitrophenol added to sterile soils that was recovered by butanol extraction declined with duration of aging, but subsequent Soxhlet extraction recovered phenanthrene from the loam but not the muck. The extents of mineralization of phenanthrene previously incubated for up to 27 days with soluble or insoluble organic matter from the muck were similar. Less aged than freshly added phenanthrene was biodegraded if aggregates in the muck were sonically disrupted. The data show that phenanthrene and 4-nitrophenol added to soil become increasingly more resistant with time to biodegradation and extraction.« less

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.

Biodegradation of PAHs in Soil: Influence of Initial PAHs Concentration

NASA Astrophysics Data System (ADS)

Kamil, N. A. F. M.; Talib, S. A.

2016-07-01

Most studies on biodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) evaluate the effect of initial PAHs concentration in liquid medium. There are limited studies on evaluation in solid medium such as contaminated soil. This study investigated the potential of the bacteria, Corynebacterium urealyticum isolated from municipal sludge in degrading phenanthrene contaminated soil in different phenanthrene concentration. Batch experiments were conducted over 20 days in reactors containing artificially contaminated phenanthrene soil at different concentration inoculated with a bacterial culture. This study established the optimum condition for phenanthrene degradation by the bacteria under nonindigenous condition at 500 mg/kg of initial phenanthrene concentration. High initial concentration required longer duration for biodegradation process compared to low initial concentration. The bacteria can survive for three days for all initial phenanthrene concentrations.

Linking of Microorganisms to Phenanthrene Metabolism in Soil by Analysis of 13C-Labeled Cell Lipids

PubMed Central

Johnsen, Anders R.; Winding, Anne; Karlson, Ulrich; Roslev, Peter

2002-01-01

Phenanthrene-metabolizing soil microbial communities were characterized by examining mineralization of [14C]phenanthrene, by most-probable-number (MPN) counting, by 16S-23S spacer DNA analysis of the numerically dominant, culturable phenanthrene-degrading isolates, and by examining incorporation of [13C]phenanthrene-derived carbon into sterols and polar lipid fatty acids (PLFAs). An unpolluted agricultural soil, a roadside soil diffusely polluted with polycyclic aromatic hydrocarbons (PAHs), and two highly PAH-polluted soils from industrial sites were analyzed. Microbial phenanthrene degraders were not detected by MPN counting in the agricultural soil and the roadside soil. In the industrial soils, phenanthrene degraders constituted 0.04 and 3.6% of the total number of CFU. 16S-23S spacer DNA analysis followed by partial 16S DNA sequencing of representative isolates from one of the industrial soils showed that one-half of the isolates belonged to the genus Sphingomonas and the other half were closely related to an unclassified beta-proteobacterium. The 13C-PLFA profiles of the two industrial soils were relatively similar and resembled the profiles of phenanthrene-degrading Sphingomonas reference strains and unclassified beta-proteobacterium isolates but did not match the profiles of Pseudomonas, Mycobacterium, or Nocardia reference strains. The 13C-PLFA profiles of phenanthrene degraders in the agricultural soil and the roadside soil were different from each other and different from the profiles of the highly polluted industrial soils. Only in the roadside soil were 10me/12me18:0 PLFAs enriched in 13C, suggesting that actinomycetes metabolized phenanthrene in this soil. The 13C-PLFA profiles of the unpolluted agricultural soil did not resemble the profiles of any of the reference strains. In all of the soils investigated, no excess 13C was recovered in the 18:2ω6,9 PLFA, suggesting that fungi did not contribute significantly to assimilation of [13C]phenanthrene. PMID:12450834

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 transfer to the food web in eutrophic waters. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

The first-principles investigations on magnetic ground-state in Sm-doped phenanthrene

NASA Astrophysics Data System (ADS)

Han, Jia-Xing; Zhong, Guo-Hua; Wang, Xiao-Hui; Chen, Xiao-Jia; Lin, Hai-Qing

2017-05-01

Based on the density functional theory plus the effective Coulomb repulsion U, we have investigated the crystal structure, electronic properties and magnetic characteristics in Sm-doped phenanthrene, recently characterized as a superconductor with Tc˜5 -6 Kelvin. Calculated total energies of different magnetic states indicate that Sm-doped phenanthrene is stable at the ferromagnetic ground-state. Considered the strong electronic correlations effect due to the intercalation of Sm-4f electrons, we found that the Sm-4f contributes to the Fermi surface together with C-2p, which is different from K-doped phenanthrene. Compared with alkali-metal-doped phenanthrene, Sm atom has larger local magnetic moment, which suppresses the superconductivity in conventional superconductors. Our results indicate that the electron-electron correlations play an important role in superconductivity of Sm-doped phenanthrene.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edlund, A.; Jansson, J.

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 thismore » 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.« less

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.

Use of nutrient supplements to increase the microbial degradation of PAH in contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carmichael, L.M.; Pfaender, F.K.

1994-12-31

The microbial degradation of polycyclic aromatic hydrocarbons (PAH) is often low in soils due to unavailability of PAH and/or to conditions in the soil that are not favorable to microbial activity. As a result, successful bioremediation of PAH contaminated soils may require the addition of supplements to impact PAH availability or soil conditions. This paper reports on the addition of supplements (Triton X-100, Inopol, nutrient buffer, an organic nutrient solution, salicylic acid) on the fate of (9-{sup 14}C) phenanthrene, a model PAH, in creosote contaminated soils. Phenanthrene metabolism was assessed using a mass balance approach that accounts for metabolism ofmore » phenanthrene to CO{sub 2}, relative metabolite production, and uptake of phenanthrene into cells. Most of the supplements did not drastically alter the fate of phenanthrene in the contaminated soils. Additions of Inopol, however, increased phenanthrene mineralization, while salicylic acid decreased phenanthrene mineralization but greatly increased the production of polar and water soluble metabolites. All supplements (excluding salicylic acid and the organic nutrient solution) increased populations of heterotrophic microorganisms, as measured by plate counts. Phenanthrene degrader populations, however, were only slightly increased by additions of the nutrient buffer, as measured by the Most Probable Number assay.« less

Source Term Modeling for Evaluating the Potential Impacts to Groundwater of Fluids Escaping from a Depleted Oil Reservoir Used for Carbon Sequestration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Kirk J.; Brown, Christopher F.

2014-06-13

In recent years depleted oil reservoirs have received special interest as carbon storage reservoirs because of their potential to offset costs through collaboration with enhanced oil recovery projects. Modeling is currently being conducted to evaluate potential risks to groundwater associated with leakage of fluids from depleted oil reservoirs used for storage of CO2. Modeling results reported here focused on understanding how toxic organic compounds found in oil will distribute between the various phases within a storage reservoir after introduction of CO2, understanding the migration potential of these compounds, and assessing potential groundwater impacts should leakage occur. Two model scenarios weremore » conducted to evaluate how organic components in oil will distribute among the phases of interest (oil, CO2, and brine). The first case consisted of 50 wt.% oil and 50 wt.% water; the second case was 90 wt.% CO2 and 10 wt.% oil. Several key organic compounds were selected for special attention in this study based upon their occurrence in oil at significant concentrations, relative toxicity, or because they can serve as surrogate compounds for other more highly toxic compounds for which required input data are not available. The organic contaminants of interest (COI) selected for this study were benzene, toluene, naphthalene, phenanthrene, and anthracene. Partitioning of organic compounds between crude oil and supercritical CO2 was modeled using the Peng-Robinson equation of state over temperature and pressure conditions that represent the entire subsurface system (from those relevant to deep geologic carbon storage environments to near surface conditions). Results indicate that for a typical set of oil reservoir conditions (75°C, and 21,520 kPa) negligible amounts of the COI dissolve into the aqueous phase. When CO2 is introduced into the reservoir such that the final composition of the reservoir is 90 wt.% CO2 and 10 wt.% oil, a significant fraction of the oil dissolves into the vapor phase. As the vapor phase moves up through the stratigraphic column, pressures and temperatures decrease, resulting in significant condensation of oil components. The heaviest organic components condense early in this process (at higher pressures and temperatures), while the lighter components tend to remain in the vapor phase until much lower pressures and temperatures are reached. Based on the model assumptions, the final concentrations of COI to reach an aquifer at 1,520 kPa and 25°C were quite significant for benzene and toluene, whereas the concentrations of polynuclear aromatic hydrocarbons that reach the aquifer were very small. This work demonstrates a methodology that can provide COI source term concentrations in CO2 leaking from a reservoir and entering an overlying aquifer for use in risk assessments.« less

Understanding boron through size-selected clusters: structure, chemical bonding, and fluxionality.

PubMed

Sergeeva, Alina P; Popov, Ivan A; Piazza, Zachary A; Li, Wei-Li; Romanescu, Constantin; Wang, Lai-Sheng; Boldyrev, Alexander I

2014-04-15

Boron is an interesting element with unusual polymorphism. While three-dimensional (3D) structural motifs are prevalent in bulk boron, atomic boron clusters are found to have planar or quasi-planar structures, stabilized by localized two-center-two-electron (2c-2e) σ bonds on the periphery and delocalized multicenter-two-electron (nc-2e) bonds in both σ and π frameworks. Electron delocalization is a result of boron's electron deficiency and leads to fluxional behavior, which has been observed in B13(+) and B19(-). A unique capability of the in-plane rotation of the inner atoms against the periphery of the cluster in a chosen direction by employing circularly polarized infrared radiation has been suggested. Such fluxional behaviors in boron clusters are interesting and have been proposed as molecular Wankel motors. The concepts of aromaticity and antiaromaticity have been extended beyond organic chemistry to planar boron clusters. The validity of these concepts in understanding the electronic structures of boron clusters is evident in the striking similarities of the π-systems of planar boron clusters to those of polycyclic aromatic hydrocarbons, such as benzene, naphthalene, coronene, anthracene, or phenanthrene. Chemical bonding models developed for boron clusters not only allowed the rationalization of the stability of boron clusters but also lead to the design of novel metal-centered boron wheels with a record-setting planar coordination number of 10. The unprecedented highly coordinated borometallic molecular wheels provide insights into the interactions between transition metals and boron and expand the frontier of boron chemistry. Another interesting feature discovered through cluster studies is boron transmutation. Even though it is well-known that B(-), formed by adding one electron to boron, is isoelectronic to carbon, cluster studies have considerably expanded the possibilities of new structures and new materials using the B(-)/C analogy. It is believed that the electronic transmutation concept will be effective and valuable in aiding the design of new boride materials with predictable properties. The study of boron clusters with intermediate properties between those of individual atoms and bulk solids has given rise to a unique opportunity to broaden the frontier of boron chemistry. Understanding boron clusters has spurred experimentalists and theoreticians to find new boron-based nanomaterials, such as boron fullerenes, nanotubes, two-dimensional boron, and new compounds containing boron clusters as building blocks. Here, a brief and timely overview is presented addressing the recent progress made on boron clusters and the approaches used in the authors' laboratories to determine the structure, stability, and chemical bonding of size-selected boron clusters by joint photoelectron spectroscopy and theoretical studies. Specifically, key findings on all-boron hydrocarbon analogues, metal-centered boron wheels, and electronic transmutation in boron clusters are summarized.

Understanding Boron through Size-Selected Clusters: Structure, Chemical Bonding, and Fluxionality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sergeeva, Alina P.; Popov, Ivan A.; Piazza, Zachary A.

Conspectus Boron is an interesting element with unusual polymorphism. While three-dimensional (3D) structural motifs are prevalent in bulk boron, atomic boron clusters are found to have planar or quasi-planar structures, stabilized by localized two-center–two-electron (2c–2e) σ bonds on the periphery and delocalized multicenter–two-electron (nc–2e) bonds in both σ and π frameworks. Electron delocalization is a result of boron’s electron deficiency and leads to fluxional behavior, which has been observed in B13+ and B19–. A unique capability of the in-plane rotation of the inner atoms against the periphery of the cluster in a chosen direction by employing circularly polarized infrared radiationmore » has been suggested. Such fluxional behaviors in boron clusters are interesting and have been proposed as molecular Wankel motors. The concepts of aromaticity and antiaromaticity have been extended beyond organic chemistry to planar boron clusters. The validity of these concepts in understanding the electronic structures of boron clusters is evident in the striking similarities of the π-systems of planar boron clusters to those of polycyclic aromatic hydrocarbons, such as benzene, naphthalene, coronene, anthracene, or phenanthrene. Chemical bonding models developed for boron clusters not only allowed the rationalization of the stability of boron clusters but also lead to the design of novel metal-centered boron wheels with a record-setting planar coordination number of 10. The unprecedented highly coordinated borometallic molecular wheels provide insights into the interactions between transition metals and boron and expand the frontier of boron chemistry. Another interesting feature discovered through cluster studies is boron transmutation. Even though it is well-known that B–, formed by adding one electron to boron, is isoelectronic to carbon, cluster studies have considerably expanded the possibilities of new structures and new materials using the B–/C analogy. It is believed that the electronic transmutation concept will be effective and valuable in aiding the design of new boride materials with predictable properties. The study of boron clusters with intermediate properties between those of individual atoms and bulk solids has given rise to a unique opportunity to broaden the frontier of boron chemistry. Understanding boron clusters has spurred experimentalists and theoreticians to find new boron-based nanomaterials, such as boron fullerenes, nanotubes, two-dimensional boron, and new compounds containing boron clusters as building blocks. Here, a brief and timely overview is presented addressing the recent progress made on boron clusters and the approaches used in the authors’ laboratories to determine the structure, stability, and chemical bonding of size-selected boron clusters by joint photoelectron spectroscopy and theoretical studies. Specifically, key findings on all-boron hydrocarbon analogues, metal-centered boron wheels, and electronic transmutation in boron clusters are summarized.« less

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 treatment. Peroxidase, phenol oxidase, and catalase activities were not affected by these treatments. Acid phosphatase activity decreased, whereas alkaline phosphatase activity increased due to biochar and fly ash treatment. Microbial biomass carbon increased significantly (P < 0.05) with biochar (+27.9%), fly ash (19.8%), and char + ash (+27.9%) applications. Maize grain yield was increased by biochar (+11.4%) and char + ash (+28.1%) treatments. The total PAH concentration decreased from 4191 μg/kg in control to 1930 μg/kg in fly ash; 1509 μg/kg in biochar and 1011 μg/kg in ash + char treatments. Among the different PAHs the concentration was higher for BkF, which decreased from 713 μg/kg in control to 139 - 315 μg/kg under different treatments. Overall, combined application of fly ash and biochar was found to be effective in amelioration of soil quality parameters and improving crop yield.

Indigenous 14C-phenanthrene biodegradation in "pristine" woodland and grassland soils from Norway and the United Kingdom.

PubMed

Okere, Uchechukwu V; Schuster, Jasmin K; Ogbonnaya, Uchenna O; Jones, Kevin C; Semple, Kirk T

2017-11-15

In this study, the indigenous microbial mineralisation of 14 C-phenanthrene in seven background soils (four from Norwegian woodland and three from the UK (two grasslands and one woodland)) was investigated. ∑PAHs ranged from 16.39 to 285.54 ng g -1 dw soil. Lag phases (time before 14 C-phenanthrene mineralisation reached 5%) were longer in all of the Norwegian soils and correlated positively with TOC, but negatively with ∑PAHs and phenanthrene degraders for all soils. 14 C-phenanthrene mineralisation in the soils varied due to physicochemical properties. The results show that indigenous microorganisms can adapt to 14 C-phenanthrene mineralisation following diffuse PAH contamination. Considering the potential of soil as a secondary PAH source, these findings highlight the important role of indigenous microflora in the processing of PAHs in the environment.

Dissolved oxygen saturation controls PAH biodegradation in freshwater estuary sediments.

PubMed

Boyd, T J; Montgomery, M T; Steele, J K; Pohlman, J W; Reatherford, S R; Spargo, B J; Smith, D C

2005-02-01

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in terrestrial and aquatic environments and can represent a significant constituent of the carbon pool in coastal sediments. We report here the results of an 18-month seasonal study of PAH biodegradation and heterotrophic bacterial production and their controlling biogeochemical factors from 186 sediment samples taken in a tidally influenced freshwater estuary. For each sampling event, measurements were averaged from 25-45 stations covering approximately 250 km(2). There was a clear relationship between bacterial production and ambient temperature, but none between production and bottom water dissolved oxygen (DO) % saturation or PAH concentrations. In contrast with other studies, we found no effect of temperature on the biodegradation of naphthalene, phenanthrene, or fluoranthene. PAH mineralization correlated with bottom water DO saturation above 70% (r(2) > 0.99). These results suggest that the proportional utilization of PAH carbon to natural organic carbon is as much as three orders of magnitude higher during cooler months, when water temperatures are lower and DO % saturation is higher. Infusion of cooler, well-oxygenated water to the water column overlying contaminated sediments during the summer months may stimulate PAH metabolism preferentially over non-PAH organic matter.

Regularities of changes in fluid composition and properties in Vankor field pools: from light to heavy oil

NASA Astrophysics Data System (ADS)

Goncharov, I. V.; Oblasov, N. V.

2015-02-01

Oil in layers Nkh 3-4, Nkh 1, Sd 9, Yak 3-7 and vYak 2-4 of the Vankor field occurs at the depth of -2,767 to -1,357 meters at strongly different temperatures: from 62 to 26 °C. Such temperature conditions contribute to oil biodegradation processes in the pool. Therefore, oils in different pools significantly differ from each other in terms of composition and properties depending on the intensity of biodegradation. At the same time, pools might embrace both oils that have practically been not exposed to biodegradation processes and significantly biodegraded oils. The most seriously altered oils are found in vYak 2-4 layer pools. They are the heaviest and the most viscous oils among the samples under study. Many typical oil components (alkanes, alkylbenzenes, naphthalenes, phenanthrenes, dibenzothiophenes) are absent in their composition. Besides, the initial distribution of hopanes in the composition of biomarkers is altered. Apart from the molecular composition of degassed oil samples, the work also studies the effect of biodegradation on the properties and the component and isotopic composition of oils, gases and formation fluid samples.

Determination of polycyclic aromatic hydrocarbons in urine of coke oven workers by headspace solid phase microextraction and gas chromatography-mass spectrometry.

PubMed

Waidyanatha, Suramya; Zheng, Yuxin; Rappaport, Stephen M

2003-05-06

Polycyclic aromatic hydrocarbons (PAHs) represent a complex mixture of toxic compounds that are ubiquitous in the environment. We investigated the utility of head space-solid phase microextraction (HS-SPME) to measure the following surrogate PAHs in urine: naphthalene (NAP), phenanthrene (PHE), pyrene (PYR), and benzo(a)pyrene (BAP), representing classes of 2-, 3-, 4- and 5-ring compounds, respectively. We then applied the method to urine from 28 coke oven workers (median levels (microg/l) were: NAP=3.65, PHE=1.51, PYR=0.003, BAP not detected) and 22 controls (median (microg/l) NAP=0.859, PHE=0.062, PYR=0.001, BAP not detected). Urinary levels of NAP, PHE, and PYR were all associated with exposure category (controls, side- and bottom-workers, and top-workers) but not with smoking status. Strong correlations were observed between urinary levels of NAP, PHE, and PYR in coke-oven workers. Our results indicate that unmetabolized 2-, 3- and 4-ring PAHs can be measured in urine by HS-SPME. Such measurements can be used to investigate the uptake and metabolism of complex PAH mixtures in humans.

Occupational Exposure to Polycyclic Aromatic Hydrocarbon of Wildland Firefighters at Prescribed and Wildland Fires.

PubMed

Navarro, Kathleen M; Cisneros, Ricardo; Noth, Elizabeth M; Balmes, John R; Hammond, S Katharine

2017-06-06

Wildland firefighters suppressing wildland fires or conducting prescribed fires work long shifts during which they are exposed to high levels of wood smoke with no respiratory protection. Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants formed during incomplete combustion. Exposure to PAHs was measured for 21 wildland firefighters suppressing two wildland fires and 4 wildland firefighters conducting prescribed burns in California. Personal air samples were actively collected using XAD4-coated quartz fiber filters and XAD2 sorbent tubes. Samples were analyzed for 17 individual PAHs through extraction with dichloromethane and gas chromatograph-mass spectrometer analysis. Naphthalene, retene, and phenanthrene were consistently the highest measured PAHs. PAH concentrations were higher at wildland fires compared to prescribed fires and were highest for firefighters during job tasks that involve the most direct contact with smoke near an actively burning wildland fire. Although concentrations did not exceed current occupational exposure limits, wildland firefighters are exposed to PAHs not only on the fire line at wildland fires, but also while working prescribed burns and while off-duty. Characterization of occupational exposures from wildland firefighting is important to understand better any potential long-term health effects.

Trichoderma longibrachiatum Evx1 is a fungal biocatalyst suitable for the remediation of soils contaminated with diesel fuel and polycyclic aromatic hydrocarbons.

PubMed

Andreolli, Marco; Lampis, Silvia; Brignoli, Pierlorenzo; Vallini, Giovanni

2016-05-01

Trichoderma sp. strain Evx1 was isolated from a semi-deciduous forest soil in Southern Italy. It decolorizes polynuclear organic dyes and tolerates high concentrations of phenanthrene, anthracene, fluoranthene, and pyrene. The ability of this ascomycete fungus to degrade polycyclic aromatic hydrocarbons was verified in vitro and confirmed by its strong phenoloxidase activity in the presence of gallic acid. Phylogenetic characterization of Trichoderma sp. Evx1 positioned this strain within the species Trichoderma longibrachiatum. The potential use of this species for the bioremediation of contaminated environmental matrices was tested by inoculating diesel-spiked soil with a dense mycelial suspension. The biodegradation percentage of the C12-40 hydrocarbon fraction in the inoculated soil rose to 54.2 ± 1.6 %, much higher than that in non-inoculated soil or soil managed solely by a combination of watering and aeration. The survival and persistence of T. longibrachiatum Evx1 throughout the bioremediation trial was monitored by PCR-DGGE analysis. The fungal strain was still present in the soil 30 days after bioaugmentation. These findings indicate that T. longibrachiatum Evx1 may be a suitable inoculum in bioremediation protocols for the reclamation of soils contaminated by complex mixtures of hydrocarbons.

Kinetics of hydrophobic organic contaminant extraction from sediment by granular activated carbon.

PubMed

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

2014-03-15

Ex situ solid phase extraction with granular activated carbon (GAC) is a promising technique to remediate contaminated sediments. The methods' efficiency depends on the rate by which contaminants are transferred from the sediment to the surface of GAC. Here, we derive kinetic parameters for extraction of polycyclic aromatic hydrocarbons (PAH) from sediment by GAC, using a first-order multi-compartment kinetic model. The parameters were obtained by modeling sediment-GAC exchange kinetic data following a tiered model calibration approach. First, parameters for PAH desorption from sediment were calibrated using data from systems with 50% (by weight) GAC acting as an infinite sink. Second, the estimated parameters were used as fixed input to obtain GAC uptake kinetic parameters in sediment slurries with 4% GAC, representing the ex situ remediation scenario. PAH uptake rate constants (kGAC) by GAC ranged from 0.44 to 0.0005 d(-1), whereas GAC sorption coefficients (KGAC) ranged from 10(5.57) to 10(8.57) L kg(-1). These values are the first provided for GAC in the presence of sediment and show that ex situ extraction with GAC is sufficiently fast and effective to reduce the risks of the most available PAHs among those studied, such as fluorene, phenanthrene and anthracene. Copyright © 2013 Elsevier Ltd. All rights reserved.

Levels, composition profiles and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in sludge from ten textile dyeing plants.

PubMed

Ning, Xun-An; Lin, Mei-Qing; Shen, Ling-Zhi; Zhang, Jian-Hao; Wang, Jing-Yu; Wang, Yu-Jie; Yang, Zuo-Yi; Liu, Jing-Yong

2014-07-01

As components of synthetic dyes, polycyclic aromatic hydrocarbons (PAHs) are present as contaminants in textile dyeing sludge due to the recalcitrance in wastewater treatment process, which may pose a threat to environment in the process of sludge disposal. In order to evaluate PAHs in textile dyeing sludge, comprehensive investigation comprising 10 textile dyeing plants was undertaken. Levels, composition profiles and risk assessment of 16 EPA-priority PAHs were analyzed in this study. The total concentrations of 16 PAHs (∑16 PAHs) varied from 1463 ± 177 ng g(-1) to 16,714 ± 1,507 ng g(-1) with a mean value of 6386 ng g(-1). The composition profiles of PAHs were characterized by 3- and 4-ring PAHs, among which phenanthrene, anthracene and fluoranthene were the most dominant components. The mean benzo[a]pyrene equivalent (BaPeq) concentration of ∑16 PAHs in textile dyeing sludge was 423 ng g(-1), which was 2-3 times higher than concentrations reported for urban soil. According to ecological risk assessment, the levels of PAHs in the textile dyeing sludge may cause a significant risk to soil ecosystem after landfill or dumping on soil. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of short-chain organic acids on the enhanced desorption of phenanthrene by rhamnolipid biosurfactant in soil-water environment.

PubMed

An, Chun-jiang; Huang, Guo-he; Wei, Jia; Yu, Hui

2011-11-01

This study investigated the effect of short-chain organic acids on biosurfactant-enhanced mobilization of phenanthrene in soil-water system. The desorption characteristics of phenanthrene by soils were assessed in the presence of rhamnolipid and four SCOAs, including acetic acid, oxalic acid, tartaric acid and citric acid. The tests with rhamnolipid and different organic acids could attain the higher desorption of phenanthrene compared to those with only rhamnolipid. Among the different combinations, the series with rhamnolipid and citric acid exhibited more significant effect on the desorption performance. The removal of phenanthrene using rhamnolipid and SCOAs gradually increased as the SCOA concentration increased up to a concentration of 300 mmol/L. The effects of pH, soil dissolved organic matter and ionic strength were further evaluated in the presence of both biosurfactant and SCOAs. The results showed that the extent of phenanthrene desorption was more significant at pH 6 and 9. Desorption of phenanthrene was relatively lower in the DOM-removed soils with the addition of biosurfactant and SCOAs. The presence of more salt ions made phenanthrene more persistent on the solid phase and adversely affected its desorption from contaminated soil. The results from this study may have important implications for soil washing technologies used to treat PAH-contaminated soil and groundwater. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mobile bacteria and transport of polynuclear aromatic hydrocarbons in porous media.

PubMed Central

Jenkins, M B; Lion, L W

1993-01-01

Sorption of hydrophobic pollutants such as polynuclear aromatic hydrocarbons (PAHs) to soil and aquifer materials can severely retard their mobility and the time course of their removal. Because mobile colloids may enhance the mobility of hydrophobic pollutants in porous media and indigenous bacteria are generally colloidal in size, bacterial isolates from soil and subsurface environments were tested for their ability to enhance the transport of phenanthrene, a model PAH, in aquifer sand. Batch isotherm experiments were performed to measure the ability of selected bacteria, including 14 isolates from a manufactured gas plant waste site, to sorb 14C-phenanthrene and to determine whether the presence of the suspended cells would reduce the distribution coefficient (Kd) for phenanthrene with the sand. Column experiments were then used to test the mobility of isolates that reduced the Kd for phenanthrene and to test the most mobile isolate for its ability to enhance the transport of phenanthrene. All of the isolates tested passively sorbed phenanthrene, and most but not all of the isolates reduced the Kd for phenanthrene. Some, but not all, of those isolates were mobile in column experiments. The most mobile isolate significantly enhanced the transport of phenanthrene in aquifer sand, reducing its retardation coefficient by 25% at a cell concentration of approximately 5 x 10(7) ml-1. The experimental results demonstrated that mobile bacteria may enhance the transport of PAHs in the subsurface. PMID:8250555

Effects of nanoplastics and microplastics on toxicity, bioaccumulation, and environmental fate of phenanthrene in fresh water.

PubMed

Ma, Yini; Huang, Anna; Cao, Siqi; Sun, Feifei; Wang, Lianhong; Guo, Hongyan; Ji, Rong

2016-12-01

Contamination of fine plastic particles (FPs), including micrometer to millimeter plastics (MPs) and nanometer plastics (NPs), in the environment has caught great concerns. FPs are strong adsorbents for hydrophobic toxic pollutants and may affect their fate and toxicity in the environment; however, such information is still rare. We studied joint toxicity of FPs with phenanthrene to Daphnia magna and effects of FPs on the environmental fate and bioaccumulation of 14 C-phenanthrene in fresh water. Within the five sizes particles we tested (from 50 nm to 10 μm), 50-nm NPs showed significant toxicity and physical damage to D. magna. The joint toxicity of 50-nm NPs and phenanthrene to D. magna showed an additive effect. During a 14-days incubation, the presence of NPs significantly enhanced bioaccumulation of phenanthrene-derived residues in daphnid body and inhibited the dissipation and transformation of phenanthrene in the medium, while 10-μm MPs did not show significant effects on the bioaccumulation, dissipation, and transformation of phenanthrene. The differences may be attributed to higher adsorption of phenanthrene on 50-nm NPs than 10-μm MPs. Our findings underlined the high potential ecological risks of FPs, and suggested that NPs should be given more concerns, in terms of their interaction with hydrophobic pollutants in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

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. Copyright © 2013 Elsevier B.V. All rights reserved.

Studies on organic semiconductors. 15: Effects of the substituents on the photoconductivities of substituted anthracenes

NASA Technical Reports Server (NTRS)

Sugimoto, A.; Kato, S.; Inoue, H.; Imoto, E.

1985-01-01

The photocurrents of the substituted anthracenes, 1,5-diacetylanthracene (2), 1-acetylanthracene (3), 9-acetylanthracene (4), 1,5-dichloroanthracene (5), 1,5-diethylanthracene (6), 1,5-dimethoxyanthracene (7), 9-cyanoanthracene (8), and anthracene (1) were measured by using their surface type cells in nitrogen. The compounds of (1), (5), (6), (7), and (8) showed the photocurrent spectra which corresponded to the absorption spectra of their evaporated films. In the cases of (2) and (3), however, the anomalous photocurrent appeared in the threshold region of their absorption spectra. The appearance of the anomalous photocurrent was characteristic of anthracenes having the acetyl group at 1- and/or 5-position. The magnitude of the photocurrents of the 1,5-disubstituted anthracenes was similar to that of (1). The photocurrents of the monosubstituted anthracenes were smaller than that of (1). Among the monosubstituted anthracenes, the compound (4) showed no photocurrent under the same conditions. Contrary to the results obtained in the cases of phenazines, the photoconductivities of the anthracene derivatives became better in air.

Oxidation of anthracene using waste Mn oxide minerals: the importance of wetting and drying sequences.

PubMed

Clarke, Catherine; Tourney, Janette; Johnson, Karen

2012-02-29

PAHs are a common problem in contaminated urban soils due to their recalcitrance. This study presents results on the oxidation of anthracene on synthetic and natural Mn oxide surfaces. Evaporation of anthracene spiked Mn oxide slurries in air results in the oxidation of 30% of the anthracene to anthraquinone. Control minerals, quartz and calcite, also oxidised a small but significant proportion of the anthracene (4.5% and 14% conversion, respectively) when spiked mineral slurries were evaporated in air. However, only Mn oxide minerals showed significant anthracene oxidation (5-10%) when evaporation took place in the absence of oxygen (N2 atmosphere). In the fully hydrated systems where no drying took place, natural Mn oxides showed an increase in anthracene oxidation with decreasing pH, with a conversion of 75% anthracene at pH 4. These results show both acidification and drying favor the oxidation of anthracene on Mn oxide mineral surfaces. It has also been demonstrated that non-redox active mineral surfaces, such as calcite, may play a role in contaminant breakdown during wetting and drying sequences. Given that climate changes suggest that wetting and drying sequences are likely to become more significant these results have important implications for contaminated land remediation technologies. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Distributions and potential sources of polycyclic aromatic hydrocarbons in surface sediments from an emerging industrial city (Xinxiang).

PubMed

Feng, Jinglan; Xi, Nannan; Zhang, Fei; Zhao, Jiahui; Hu, Pengtuan; Sun, Jianhui

2016-01-01

To investigate the distributions, degree, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in bed sediments from four rivers of Xinxiang, 18 sediment samples were analyzed. The concentrations ranged from 4.45 × 10(3) to 29.0 × 10(3) ng/g for ∑15PAHs (sum of US Environmental Protection Agency (EPA) priority PAHs apart from naphthalene (Nap)) and 3.37 × 10(3) to 23.5 × 10(3) ng/g for ∑7carPAHs (including benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DBA), and indeno[1,2,3-cd]pyrene (InP)) with average concentrations of 10.7 × 10(3) and 7.99 × 10(3) ng/g, respectively. Compared with those from other rivers in China, sediments from four rivers of Xinxiang were severely polluted with PAHs. Pearson correlation analysis showed that ∑15PAHs concentrations had a significant positive correlation with black carbon content. Four- to six-ring PAHs accounted for 83.4 % of total PAHs, which indicated that the main source of PAHs in the studied area could be pyrogenic contamination. Source apportionment using PCA/MLR and UNMIX revealed that coal and biomass combustion contributed 64.4-67.1 %, gasoline vehicle 23.2-27.2 %, and diesel vehicle 5.70-12.4 % of the total PAHs, respectively. The effects range low/effects range median (ERL/ERM) values showed that there was a high level of toxicity risk for BaA. The ecological risk assessment by mean effects range median quotients (mERMQ) revealed a medium ecological risk of ∑15PAHs in sediments from four rivers of Xinxiang, manifesting that a close attention should be paid to pollution of PAHs in the studied area.

Specific adsorption of cadmium on surface-engineered biocompatible organoclay under metal-phenanthrene mixed-contamination.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

2016-11-01

Bioremediation of polycyclic aromatic hydrocarbons (PAHs) is extremely challenging when they coexist with heavy metals. This constrain has led to adsorption-based techniques that help immobilize the metals and reduce toxicity. However, the adsorbents can also non-selectively bind the organic compounds, which reduces their bioavailability. In this study we developed a surface-engineered organoclay (Arquad ® 2HT-75-bentonite-palmitic acid) which enhanced bacterial proliferation and adsorbed cadmium, but elevated phenanthrene bioavailability. Adsorption models of single and binary solutes revealed that the raw bentonite adsorbed cadmium and phenanthrene non-selectively at the same binding sites and sequestrated phenanthrene. In contrast, cadmium selectively bound to the deprotonated state of carboxyl groups in the organoclay and phenanthrene on the outer surface of the adsorbent led to a microbially congenial microenvironment with a higher phenanthrene bioavailability. This study provided valuable information which would be highly important for developing a novel clay-modulated bioremediation technology for cleaning up PAHs under mixed-contaminated situations. Copyright © 2016 Elsevier Ltd. All rights reserved.

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. Copyright 2003 Elsevier Science B.V.

Solubilization of phenanthrene above cloud point of Brij 30: a new application in biodegradation.

PubMed

Pantsyrnaya, T; Delaunay, S; Goergen, J L; Guseva, E; Boudrant, J

2013-06-01

In the present study a new application of solubilization of phenanthrene above cloud point of Brij 30 in biodegradation was developed. It was shown that a temporal solubilization of phenanthrene above cloud point of Brij 30 (5wt%) permitted to obtain a stable increase of the solubility of phenanthrene even when the temperature was decreased to culture conditions of used microorganism Pseudomonas putida (28°C). A higher initial concentration of soluble phenanthrene was obtained after the cloud point treatment: 200 against 120μM without treatment. All soluble phenanthrene was metabolized and a higher final concentration of its major metabolite - 1-hydroxy-2-naphthoic acid - (160 against 85μM) was measured in the culture medium in the case of a preliminary cloud point treatment. Therefore a temporary solubilization at cloud point might have a perspective application in the enhancement of biodegradation of polycyclic aromatic hydrocarbons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparing Urinary Biomarkers of Airborne and Dermal Exposure to Polycyclic Aromatic Compounds in Asphalt-Exposed Workers

PubMed Central

Sobus, Jon R.; McClean, Michael D.; Herrick, Robert F.; Waidyanatha, Suramya; Nylander-French, Leena A.; Kupper, Lawrence L.; Rappaport, Stephen M.

2009-01-01

When working with hot mix asphalt, road pavers are exposed to polycyclic aromatic hydrocarbons (PAHs) through the inhalation of vapors and particulate matter (PM) and through dermal contact with PM and contaminated surfaces. Several PAHs with four to six rings are potent carcinogens which reside in these particulate emissions. Since urinary biomarkers of large PAHs are rarely detectable in asphalt workers, attention has focused upon urinary levels of the more volatile and abundant two-ring and three-ring PAHs as potential biomarkers of PAH exposure. Here, we compare levels of particulate polycyclic aromatic compounds (P-PACs, a group of aromatic hydrocarbons containing PAHs and heterocyclic compounds with four or more rings) in air and dermal patch samples from 20 road pavers to the corresponding urinary levels of naphthalene (U-Nap) (two rings), phenanthrene (U-Phe) (three rings), monohydroxylated metabolites of naphthalene (OH-Nap) and phenanthrene (OH-Phe), and 1-hydroxypyrene (OH-Pyr) (four rings), the most widely used biomarker of PAH exposure. For each worker, daily breathing-zone air (n = 55) and dermal patch samples (n = 56) were collected on three consecutive workdays along with postshift, bedtime, and morning urine samples (n = 149). Measured levels of P-PACs and the urinary analytes were used to statistically model exposure–biomarker relationships while controlling for urinary creatinine, smoking status, age, body mass index, and the timing of urine sampling. Levels of OH-Phe in urine collected postshift, at bedtime, and the following morning were all significantly associated with levels of P-PACs in air and dermal patch samples. For U-Nap, U-Phe, and OH-Pyr, both air and dermal patch measurements of P-PACs were significant predictors of postshift urine levels, and dermal patch measurements were significant predictors of bedtime urine levels (all three analytes) and morning urine levels (U-Nap and OH-Pyr only). Significant effects of creatinine concentration were observed for all analytes, and modest effects of smoking status and body mass index were observed for U-Phe and OH-Pyr, respectively. Levels of OH-Nap were not associated with P-PAC measurements in air or dermal patch samples but were significantly affected by smoking status, age, day of sample collection, and urinary creatinine. We conclude that U-Nap, U-Phe, OH-Phe, and OH-Pyr can be used as biomarkers of exposure to particulate asphalt emissions, with OH-Phe being the most promising candidate. Indications that levels of U-Nap, U-Phe, and OH-Pyr were significantly associated with dermal patch measurements well into the evening after a given work shift, combined with the small ratios of within-person variance components to between-person variance components at bedtime, suggest that bedtime measurements may be useful for investigating dermal PAH exposures. PMID:19602502

Polycyclic aromatic hydrocarbons and their derivatives in indoor and outdoor air in an eight-home study

NASA Astrophysics Data System (ADS)

Chuang, Jane C.; Mack, Gregory A.; Kuhlman, Michael R.; Wilson, Nancy K.

A pilot field study was performed in Columbus, OH, during the winter of 1986/1987. The objectives were to determine the feasibility of the use of a newly developed quiet sampler in indoor air sampling for particles and semivolatile organic compounds (SVOC) and to measure the concentrations of polycyclic aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in air in selected residences. Eight homes were chosen for sampling on the basis of these characteristics: electric/gas heating system, electric/gas cooking appliances, and the absence/presence of environmental tobacco smoke (ETS). The indoor sampler was equipped with a quartz-fiber filter to collect particles followed by XAD-4 resin to trap SVOC. A PS-1 sampler with a similar sampling module was used outdoors. The indoor air was sampled in the kitchen and living room areas over two consecutive 8-h periods. The outdoor air was sampled concurrently with the indoor samples over a 16-h period. Fifteen PAH, five nitro-PAH, five oxygenated PAH, and three nitrogen heterocyclic compounds were determined in these samples. The most abundant PAH found indoors was naphthalene. The indoor concentrations of PAH derivatives were lower than those of their parent compounds. Average concentrations of all but three target compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) were higher indoors than outdoors. Environmental tobacco smoke was the most significant influence on indoor pollutant levels. Homes with gas heating systems had higher indoor pollutant levels than homes with electric heating systems. However, the true effects of heating and cooking systems were not characterized as accurately as the effects of ETS because of the small sample sizes and the lack of statistical significance for most pollutant differences in the absence of ETS. The concentrations of PAH marker compounds (phenanthrene, fluoranthene, and pyrene) correlated well with the concentrations of other target compounds. Quinoline and isoquinoline can be used to indicate indoor levels of ETS.

Barium alginate caged Fe3O4@C18 magnetic nanoparticles for the pre-concentration of polycyclic aromatic hydrocarbons and phthalate esters from environmental water samples.

PubMed

Zhang, Shengxiao; Niu, Hongyun; Cai, Yaqi; Shi, Yali

2010-04-30

The hydrophobic octadecyl (C(18)) functionalized Fe(3)O(4) magnetic nanoparticles (Fe(3)O(4)@C(18)) were caged into hydrophilic barium alginate (Ba(2+)-ALG) polymers to obtain a novel type of solid-phase extraction (SPE) sorbents, and the sorbents were applied to the pre-concentration of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) pollutants from environmental water samples. The hydrophilicity of the Ba(2+)-ALG cage enhances the dispersibility of sorbents in water samples, and the superparamagnetism of the Fe(3)O(4) core facilitates magnetic separation. With the magnetic SPE technique based on the Fe(3)O(4)@C(18)@Ba(2+)-ALG sorbents, it requires only 30 min to extract trace levels of analytes from 500 mL water samples. After the eluate is condensed to 0.5 mL, concentration factors for both phenanthrene and di-n-propyl-phthalate are over 500, while for other analytes are about 1000. The recoveries of target compounds are independent of salinity and solution pH under testing conditions. Under optimized conditions, the detection limits for phenanthrene, pyrene, benzo[a]anthracene, and benzo[a]pyrene are 5, 5, 3, and 2 ng L(-1), and for di-n-propyl-phthalate, di-n-butyl-phthalate, di-cyclohexyl-phthalate, and di-n-octyl-phthalate are 36, 59, 19, and 36 ng L(-1), respectively. The spiked recoveries of several real water samples for PAHs and PAEs are in the range of 72-108% with relative standard deviations varying from 1% to 9%, showing good accuracy of the method. The advantages of the new SPE method include high extraction efficiency, short analysis time and convenient extraction procedure. To the best of our knowledge, it is unprecedented that hydrophilic Ba(2+)-ALG polymer caged Fe(3)O(4)@C(18) magnetic nanomaterial is used to extract organic pollutants from large volumes of water samples. Copyright 2010 Elsevier B.V. All rights reserved.

Long-term reproductive and behavioral toxicity of anthracene to fish in the presence of solar ultraviolet radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, A.T.; Oris, J.T.

1994-12-31

The long-term, low-level effects of anthracene in the presence of solar ultraviolet radiation (SUVR) were examined in the fathead minnow (Pimephales promelas). Adult fish exposed to anthracene exhibited reduced egg laying capacity, with altered oocyte maturation as a potential mechanism of action. Eggs and larvae maternally exposed to anthracene exhibited reduced hatching success and severe developmental abnormalities when incubated under SUVR. The combination of reduced egg output and developmental effects resulted in an inhibition in reproductive capacity in the range of 70--100%. Maternal transfer of anthracene to eggs was efficient; the BCF was 717 for maternally exposed eggs. However, anthracenemore » deputation from eggs after oviposition with only maternal PAH exposure was rapid; anthracene half-life from eggs equaled 1.3 days. Exposure to anthracene under SUVR altered locomotor activity patterns in fathead minnows by inducing hyperactivity or hypoactivity during the light or dark phases of the photoperiod, respectively. Altered activity patterns indicated potential effects of anthracene on the nervous system and/or pineal gland. These alterations disrupted normal activity patterns and reproductive behaviors, and thus have major implications on a fish`s ability to survive and reproduce. Anthracene, a model phototoxic PAH, has many potential sites of toxic action, and any organism exposed to such contaminants will be an considerable SUVR-enhanced risk in the environment.« less

Characterization of a photoproduct of 7,12-dimethylbenz[alpha]anthracene and its effects on chick-embryo cells in culture.

PubMed Central

Warshawsky, D; Kerns, E; Bissell, M J; Calvin, M

1977-01-01

A common impurity of 7,12-dimethylbenz[alpha]anthracene was more effective than 7,12-dimethylbenz[alpha]anthracene in inducing morphological alterations, and in causing an increase in glucose uptake, DNA synthesis and cell number in chick-embryo fibroblasts. Gradual morphological transformation follows the increase in DNA synthesis after 2 days when either primary or secondary cultures are treated with 3 microgram of the compound/ml. The compound, isolated from 7,12-dimethylbenz[alpha]anthracene by alumina column chromatography, was characterized by t.l.c., mass spectroscopy, carbon-hydrogen analysis, u.v. and nuclear-magnetic-resonance spectroscopy and thermal decomposition. It was the photo-oxidation product of 7,12-dimethylbenz[alpha]anthracene, 7,12-epidioxy-7,12-dimethylbenz[alpha]anthracene. It is suggested that some of the biological effects observed after treatment of cultures with 7,12-dimethylbenz[alpha]anthracene may be due in part to the presence of the photo-oxidation product. PMID:407902

Turbulent Coagulation of Particles Smaller Than the Length Scales of Turbulence and Equilibrium Sorption of Phenanthrene to Clay: Implications for Pollutant Transport in the Estuarine Water Column

DTIC Science & Technology

1997-05-01

estuaries was modeled using phenanthrene, bacterial extracellular polymer and kaolinite clay as surrogates for a hydrophobic organic pollutant...coefficients obtained for phenanthrene sorption to kaolinite and bentonite in the presence of varying amounts of DOM represented by alginic acid and tannic...acid. 333 Table B.3: Literature values for sorption between phenanthrene, humic acid and kaolinite for [DOM]a = 10 mg/L 334 Table E.1: Sample output data

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparative transcriptomic evidence for Tween80-enhanced biodegradation of phenanthrene by Sphingomonas sp. GY2B.

PubMed

Liu, Shasha; Guo, Chuling; Lin, Weijia; Wu, Fengji; Lu, Guining; Lu, Jing; Dang, Zhi

2017-12-31

Previous study of the effects of surfactants on the biodegradation of phenanthrene focused on investigating alterations of the cell characteristics of Sphingomonas sp. GY2B. However, genes regulation associated with biodegradation and biological processes in response to the presence of surfactants, remains unclear. In this study, comparative transcriptome analysis was conducted to observe the gene expression of GY2B during phenanthrene biodegradation in the presence and absence of Tween80. A diverse set of genes was regulated by Tween80, leading to increased biodegradation of phenanthrene by GY2B: (i) Tween80 increased expression of genes related to H + transport in the plasma membrane to provide a driving force (i.e., ATP) for accelerating transmembrane transport of phenanthrene with increasing Tween80 concentrations, thereby enhancing the uptake and degradation of phenanthrene by GY2B; (ii) Tween80 (1 and 8 CMC) promoted intracellular biodegradation of phenanthrene by stimulating expression of genes encoding dioxygenases and monooxygenase, increasing expression of genes involved in intracellular metabolic processes (e.g., TCA cycle); and (iii) Tween80 likely increased GY2B vitality and growth by inducing expression of genes associated with ABC transporters and protein transport, regulating genes involved in other biological processes (e.g., transcription, translation). Copyright © 2017. Published by Elsevier B.V.

Inoculation of a phenanthrene-degrading endophytic bacterium reduces the phenanthrene level and alters the bacterial community structure in wheat.

PubMed

Liu, Juan; Xiang, Yanbing; Zhang, Zhiming; Ling, Wanting; Gao, Yanzheng

2017-06-01

Colonization by polycyclic aromatic hydrocarbon (PAH)-degrading endophytic bacteria (PAHDEB) can reduce the PAH contamination risk in plant. However, little information is available on the impact of PAHDEB colonization on the endophytic bacterial community of inner plant tissues. A phenanthrene-degrading endophytic bacterium (PDEB), Massilia sp. Pn2, was inoculated onto the roots of wheat and subjected to greenhouse container experiments. The endophytic bacterial community structure in wheat was investigated using high-throughput sequencing technology. The majority of endophytic bacteria in wheat were Proteobacteria, and the dominant genus was Pseudomonas. Phenanthrene contamination clearly increased the diversity of endophytic bacteria in wheat. The cultivable endophytic bacteria counts in wheat decreased with increasing the level of phenanthrene contamination; the endophytic bacterial community structure changed correspondingly, and the bacterial richness first increased and then decreased. Inoculation of strain Pn2 reduced the phenanthrene contamination in wheat, enlarged the biomass of wheat roots, changed the bacterial community structure and enhanced the cell counts, diversity and richness of endophytic bacteria in phenanthrene-contaminated wheat in a contamination level-dependent manner. The findings of this investigation provide insight into the responses of endophytic bacterial community in plant to external PAH contamination and PAHDEB colonization.

Lentinus (Panus) tigrinus augmentation of a historically contaminated soil: matrix decontamination and structure and function of the resident bacterial community.

PubMed

Federici, E; Giubilei, M A; Cajthaml, T; Petruccioli, M; D'Annibale, A

2011-02-28

The ability of Lentinus tigrinus to grow and to degrade persistent aromatic hydrocarbons in aged contaminated soil was assessed in this study. L. tigrinus extensively colonized the soil; its degradation activity after 60 d incubation at 28°C, however, was mostly limited to dichloroaniline isomers, polychlorinated benzenes and diphenyl ether while the fungus was unable to deplete 9,10-anthracenedione and 7-H-benz[DE]anthracene-7-one which were the major soil contaminants. Although clean-up levels were limited, both density of cultivable heterotrophic bacteria and richness of the resident bacterial community in L. tigrinus microcosms (LtM) increased over time to a significantly larger extent than the respective amended incubation controls (1.9×10(9) CFU g(-1) vs. 1.0×10(9) CFU g(-1) and 37 vs. 16, respectively). Naphthalene- and catechol 2,3-dioxygenase gene copy numbers, however, decreased over time at a higher rate in LtM than in incubation controls likely due to a higher stimulation on heterotrophs than xenobiotics-degrading community members. Copyright © 2010 Elsevier B.V. All rights reserved.

Optical band gaps of organic semiconductor materials

NASA Astrophysics Data System (ADS)

Costa, José C. S.; Taveira, Ricardo J. S.; Lima, Carlos F. R. A. C.; Mendes, Adélio; Santos, Luís M. N. B. F.

2016-08-01

UV-Vis can be used as an easy and forthright technique to accurately estimate the band gap energy of organic π-conjugated materials, widely used as thin films/composites in organic and hybrid electronic devices such as OLEDs, OPVs and OFETs. The electronic and optical properties, including HOMO-LUMO energy gaps of π-conjugated systems were evaluated by UV-Vis spectroscopy in CHCl3 solution for a large number of relevant π-conjugated systems: tris-8-hydroxyquinolinatos (Alq3, Gaq3, Inq3, Al(qNO2)3, Al(qCl)3, Al(qBr)3, In(qNO2)3, In(qCl)3 and In(qBr)3); triphenylamine derivatives (DDP, p-TTP, TPB, TPD, TDAB, m-MTDAB, NPB, α-NPD); oligoacenes (naphthalene, anthracene, tetracene and rubrene); oligothiophenes (α-2T, β-2T, α-3T, β-3T, α-4T and α-5T). Additionally, some electronic properties were also explored by quantum chemical calculations. The experimental UV-Vis data are in accordance with the DFT predictions and indicate that the band gap energies of the OSCs dissolved in CHCl3 solution are consistent with the values presented for thin films.

Removal of polycyclic aromatic hydrocarbons from soil: a comparison between bioremoval and supercritical fluids extraction.

PubMed

Amezcua-Allieri, M A; Ávila-Chávez, M A; Trejo, A; Meléndez-Estrada, J

2012-03-01

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic substances which are resistant to environmental degradation due to their highly hydrophobic nature. Soils contaminated with PAHs pose potential risks to human and ecological health, therefore concern over their adverse effects have resulted in extensive studies on their removal from contaminated soils. The main purpose of this study was to compare experimental results of PAHs removal, from a natural certified soil polluted with PAHs, by biological methods (using bioaugmentation and biostimulation in a solid-state culture) with those from supercritical fluid extraction (SFE), using supercritical ethane as solvent. The comparison of results between the two methods showed that maximal removal of naphthalene, acenaphthene, fluorene, and chrysene was performed using bioremediation; however, for the rest of the PAHs considered (fluoranthene, pyrene, and benz(a)anthracene) SFE resulted more efficient. Although bioremediation achieved higher removal ratios for certain hydrocarbons and takes advantage of the increased rate of natural biological processes, it takes longer time (i.e. 36 d vs. half an hour) than SFE and it is best for 2-3 PAHs rings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Seasonal variation, sources and gas/particle partitioning of polycyclic aromatic hydrocarbons in Guangzhou, China.

PubMed

Yang, Yunyun; Guo, Pengran; Zhang, Qian; Li, Deliang; Zhao, Lan; Mu, Dehai

2010-05-15

Air samples were collected weekly at an urban site and a suburban site in Guangzhou City, China, from April 2005 to March 2006, to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs) in the ambient air and study their seasonal variations, gas/particle partitioning, origins and sources. The concentrations of summation Sigma16-PAHs (particle+gas) were 129.9+/-73.1 ng m(-)(3) at the urban site and 120.4+/-48.5 ng m(-)(3) at the suburban site, respectively. It was found that there was no significant difference in PAH concentrations between the urban and suburban sites. Seasonal variations of PAH concentrations at the two sampling sites were similar, with higher levels in the winter that gradually decreased to the lowest levels in the summer. The average concentrations of summation Sigma16-PAHs in the winter samples were approximately three times higher than those of the summer samples because in the summer local emissions dominated, and in the winter the contribution from outside sources or transported PAHs is increased. The plot of logK(p) versus logP(L)(0) for the data sets of summer and winter season samples had significantly different slopes at both sampling sites. The slopes for the winter samples were steeper than those for the summer samples. It was also observed that gas/particle partitioning of PAHs showed different characteristics depending on air parcel trajectories. Steeper slopes were obtained for an air parcel that traveled across the continent to the sampling site from the northern or northeastern sector, whereas shallower slopes were obtained for air masses that traveled across the sea from the southern or eastern sector. Diagnostic ratio analytical results imply that the origins of PAHs were mainly from petroleum combustion and coal/biomass burning. The anthracene/phenanthrene and benzo[a]anthracene/chrysene ratios in the winter were significantly lower than those in the summer, which indicate that there might be long-range transported PAH input to Guangzhou in the winter. Copyright 2010 Elsevier B.V. All rights reserved.

Sediment contamination of residential streams in the metropolitan kansas city area, USA: Part I. distribution of polycyclic aromatic hydrocarbon and pesticide-related compounds

USGS Publications Warehouse

Tao, J.; Huggins, D.; Welker, G.; Dias, J.R.; Ingersoll, C.G.; Murowchick, J.B.

2010-01-01

This is the first part of a study that evaluates the influence of nonpoint-source contaminants on the sediment quality of five streams within the metropolitan Kansas City area, central United States. Surficial sediment was collected in 2003 from 29 sites along five streams with watersheds that extend from the core of the metropolitan area to its development fringe. Sediment was analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), 3 common polychlorinated biphenyl mixtures (Aroclors), and 25 pesticide-related compounds of eight chemical classes. Multiple PAHs were detected at more than 50% of the sites, and concentrations of total PAHs ranged from 290 to 82,150 ??g/kg (dry weight). The concentration and frequency of detection of PAHs increased with increasing urbanization of the residential watersheds. Four- and five-ring PAH compounds predominated the PAH composition (73-100%), especially fluoranthene and pyrene. The PAH composition profiles along with the diagnostic isomer ratios [e.g., anthracene/(anthracene + phenanthrene), 0.16 ?? 0.03; fluoranthene/(fluoranthene + pyrene), 0.55 ?? 0.01)] indicate that pyrogenic sources (i.e., coal-tar-related operations or materials and traffic-related particles) may be common PAH contributors to these residential streams. Historical-use organochlorine insecticides and their degradates dominated the occurrences of pesticide-related compounds, with chlordane and dieldrin detected in over or nearly 50% of the samples. The occurrence of these historical organic compounds was associated with past urban applications, which may continue to be nonpoint sources replenishing local streams. Concentrations of low molecular weight (LMW; two or three rings) and high molecular weight (HMW; four to six rings) PAHs covaried along individual streams but showed dissimilar distribution patterns between the streams, while the historical pesticide-related compounds generally increased in concentration downstream. Correlations were noted between LMW and HMW PAHs for most of the streams and between historical-use organochlorine compounds and total organic carbon and clay content of sediments for one of the streams (Brush Creek). Stormwater runoff transport modes are proposed to describe how the two groups of contaminants migrated and distributed in the streambed. ?? 2010 Springer Science+Business Media, LLC.

SYNTHESIS OF p-TRIFLUOROMETHYL-TOLUENE AND 3,6-BIS(TRIFLUOROMETHYL) PHENANTHRENE USING SULFUR TETRAFLUORIDE

DTIC Science & Technology

studies on the soxhlet extractors showed promise that separation and isolation is possible. Corrosion data gathered during the course of the p-toluic...production of 3, 6-bis(trifluoromethyl) phenanthrene based on a 20% conversion to 3,6- bis(trifluoromethyl) phenanthrene plus an additional 30% yield of

Fate of phenanthrene and mineralization of its non-extractable residues in an oxic soil.

PubMed

Wang, Yongfeng; Xu, Jun; Shan, Jun; Ma, Yini; Ji, Rong

2017-05-01

The fate of organic pollutants in the environment, especially the formation and stability of non-extractable (i.e., bound) residues (NERs) determines their environmental risk. Using 14 C-tracers, we studied the fate of the carcinogen phenanthrene in active or sterilized oxic loamy soil in the absence and presence of the geophagous earthworm Metaphire guillelmi and characterized the NERs derived from phenanthrene. After incubation of 14 C-phenanthrene in active soil for 28 days, 40 ± 3.1% of the initial amount was mineralized and 70.1 ± 1.9% was converted to NERs. Most of the NERs (>92%) were bound to soil humin. Silylation of the humin-bound residues released 45.3 ± 5.3% of these residues, which indicated that they were physically entrapped, whereas the remainder of the residues were chemically bound or biogenic. By contrast, in sterilized soil, only 43.4 ± 12.6% of the phenanthrene was converted to NERs and all of these residues were completely released upon silylation, which underlines the essential role of microbial activity in NER formation. The presence of M. guillelmi in active soil significantly inhibited phenanthrene mineralization (24.4 ± 2.6% mineralized), but NER formation was not significantly affected. Only a small amount of phenanthrene-derived residues (1.9-5.3% of the initial amount) accumulated in the earthworm body. When humin-bound residues were mixed with fresh soil, 33.9% (humin recovered from active soils) and 12.4% (humin recovered from sterilized soils) of the residues were mineralized after 75 days of incubation, respectively, which indicated a high bioavailability of NERs, albeit lower than the initial addition of phenanthrene. Our results indicated that many phenanthrene-derived NERs, especially those physically entrapped, are still bioavailable and may pose a toxic threat to soil organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling collision energy transfer in APCI/CID mass spectra of PAHs using thermal-like post-collision internal energy distributions

NASA Astrophysics Data System (ADS)

Solano, Eduardo A.; Mohamed, Sabria; Mayer, Paul M.

2016-10-01

The internal energy transferred when projectile molecular ions of naphthalene collide with argon gas atoms was extracted from the APCI-CID (atmospheric-pressure chemical ionization collision-induced dissociation) mass spectra acquired as a function of collision energy. Ion abundances were calculated by microcanonical integration of the differential rate equations using the Rice-Ramsperger-Kassel-Marcus rate constants derived from a UB3LYP/6-311G+(3df,2p)//UB3LYP/6-31G(d) fragmentation mechanism and thermal-like vibrational energy distributions p M (" separators=" E , T char ) . The mean vibrational energy excess of the ions was characterized by the parameter Tchar ("characteristic temperature"), determined by fitting the theoretical ion abundances to the experimental breakdown graph (a plot of relative abundances of the ions as a function of kinetic energy) of activated naphthalene ions. According to these results, the APCI ion source produces species below Tchar = 1457 K, corresponding to 3.26 eV above the vibrational ground state. Subsequent collisions heat the ions up further, giving rise to a sigmoid curve of Tchar as a function of Ecom (center-of-mass-frame kinetic energy). The differential internal energy absorption per kinetic energy unit (dEvib/dEcom) changes with Ecom according to a symmetric bell-shaped function with a maximum at 6.38 ± 0.32 eV (corresponding to 6.51 ± 0.27 eV of vibrational energy excess), and a half-height full width of 6.30 ± 1.15 eV. This function imposes restrictions on the amount of energy that can be transferred by collisions, such that a maximum is reached as kinetic energy is increased. This behavior suggests that the collisional energy transfer exhibits a pronounced increase around some specific value of energy. Finally, the model is tested against the CID mass spectra of anthracene and pyrene ions and the corresponding results are discussed.

Modeling collision energy transfer in APCI/CID mass spectra of PAHs using thermal-like post-collision internal energy distributions.

PubMed

Solano, Eduardo A; Mohamed, Sabria; Mayer, Paul M

2016-10-28

The internal energy transferred when projectile molecular ions of naphthalene collide with argon gas atoms was extracted from the APCI-CID (atmospheric-pressure chemical ionization collision-induced dissociation) mass spectra acquired as a function of collision energy. Ion abundances were calculated by microcanonical integration of the differential rate equations using the Rice-Ramsperger-Kassel-Marcus rate constants derived from a UB3LYP/6-311G+(3df,2p)//UB3LYP/6-31G(d) fragmentation mechanism and thermal-like vibrational energy distributions p M E,T char . The mean vibrational energy excess of the ions was characterized by the parameter T char ("characteristic temperature"), determined by fitting the theoretical ion abundances to the experimental breakdown graph (a plot of relative abundances of the ions as a function of kinetic energy) of activated naphthalene ions. According to these results, the APCI ion source produces species below T char = 1457 K, corresponding to 3.26 eV above the vibrational ground state. Subsequent collisions heat the ions up further, giving rise to a sigmoid curve of T char as a function of E com (center-of-mass-frame kinetic energy). The differential internal energy absorption per kinetic energy unit (dE vib /dE com ) changes with E com according to a symmetric bell-shaped function with a maximum at 6.38 ± 0.32 eV (corresponding to 6.51 ± 0.27 eV of vibrational energy excess), and a half-height full width of 6.30 ± 1.15 eV. This function imposes restrictions on the amount of energy that can be transferred by collisions, such that a maximum is reached as kinetic energy is increased. This behavior suggests that the collisional energy transfer exhibits a pronounced increase around some specific value of energy. Finally, the model is tested against the CID mass spectra of anthracene and pyrene ions and the corresponding results are discussed.

Kinetics of sorption of polyaromatic hydrocarbons onto granular activated carbon and Macronet hyper-cross-linked polymers (MN200).

PubMed

Valderrama, C; Cortina, J L; Farran, A; Gamisans, X; Lao, C

2007-06-01

Polymeric supports are presented as an alternative to granular activated carbon (GAC) for organic contaminant removal from groundwater using permeable reactive barriers (PRB). The search for suitable polymeric sorbents for hydrocarbon extraction from aqueous streams has prompted the synthesis of new resins incorporating new functionalities or modifying the polymer network properties that solve many of the existing problems. Between them, the new type of polymeric sorbents Macronet Hypersol containing a styrene-divinylbenzene macroporous hyperreticulated network has been evaluated. Because of their potential sorptive properties, tests were conducted to determine the feasibility of using them as a low-cost reactive material for groundwater applications. The present work describes the sorption of six polycyclic hydrocarbons (PAHs) from aqueous solution onto both Macronet polymeric sorbent MN200 and granular activated carbon. Batch experiments were performed to determine loading rates of a family of PAHs (naphthalene, fluorene, anthracene, acenaphthene, pyrene, and fluoranthene), from a simple two-rings PAH (naphthalene) up to a four-ring PAH (pyrene). The behavior of a non-functionalized Macronet support (MN200) was compared with the behavior of a recognized material, granular activated carbon (GAC). Analyses of the respective rate data with three theoretical models (pseudo-first- and pseudo-second-order reaction models and the Elovich model) were used to describe the PAH sorption kinetics. Sorption rate constants were determined by graphical analysis of the proposed models. The study showed that sorption systems followed a pseudo-first-order reaction model, although the pseudo-second-order reaction model provides an acceptable description of the sorption process. Graphical analysis showed that the sorption process with activated carbon is a more complex process than the one observed for hyper-cross-linked polymers (MN200). A simulation of the barrier thickness needed to treat a PAH-polluted plume showed that 0.1-1 m of sorption media is enough even for high water fluxes such as 0.1-2 m(3)/m(2)/day for both sorbents.

The onset of anthracene phototoxicity to Lemna gibba and the protective effects of humic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gensemer, R.W.; Dixon, D.G.; Greenberg, B.M.

1994-12-31

The toxicity of anthracene to the freshwater duckweed Lemna gibba is strongly photo-induced in the presence of light containing natural levels of ultraviolet (UV) radiation. This was demonstrated using 8-day static renewal bioassays at an anthracene concentration of 2 mg-L{sup {minus}1}. Plants were incubated under simulated solar radiation (SSR) which mimics UV levels found in natural sunlight at a visible:UV-A:UV-B ratio of 100:10:1. Anthracene phototoxicity was expressed as inhibition of population growth and fluorescence induction decreases in chlorophyll content, and changes in low-temperature chlorophyll fluorescence emission scans. Furthermore, adding 6.2 mg-L-1 of an artificial humic acid ameliorated anthracene phototoxicity evenmore » though HA is also photo modified by UV light. However, anthracene inhibited photosynthesis days before the endpoint assays were performed. Therefore, the authors repeated these experiments at short time intervals following exposure to both light and chemical. Anthracene phototoxicity occurred after only 1 hour as detected by chlorophyll fluorescence induction, whereas chlorophyll contents and low-temperature fluorescence emission scans were not affected until 24--48 hours, respectively. Humic acid again ameliorated anthracene toxicity by delaying the negative physiological events by approximately 24 hours.« less

Degradation of anthracene by laccase of Trametes versicolor in the presence of different mediator compounds.

PubMed

Johannes, C; Majcherczyk, A; Hüttermann, A

1996-10-01

Laccase of Trametes versicolor was generally able to oxidize anthracene in vitro. After 72 h incubation about 35% of the anthracene was transformed stoichiometrically to 9,10-anthraquinone. Transformation of anthracene increased rapidly in the presence of different mediators that readily generate stable radicals: 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 1-hydroxybenzotriazole. For the reaction, the presence of both the laccase and the mediator was necessary. In the presence of 0.005 mM 1-hydroxybenzotriazole this conversion had removed 47% of the anthracene after 72 h; 75% of the substrate was oxidized during this period when ABTS (1 mM) was used as mediator. In contrast to reactions without or with only low concentrations of a mediator, there was a discrepancy between the disappearance of anthracene and the formation of 9,10-anthraquinone in mediator-forced reactions. Coupling-products of mediators with anthracene degradation products were found. Anthracene disappeared nearly completely after incubation for 72 h with laccase in a 0.1 mM solution of 1-hydroxybenzotriazole and was transformed to 9,10-anthraquinone in about 80% yield; 90% of the substrate was transformed in the presence of ABTS (2.0 mM) resulting again in 80% quinone. Phenothiazine was not effective in this system.

Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character

PubMed Central

Rice, James W.; Fu, Jinxia; Suuberg, Eric M.

2010-01-01

To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x1 = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x1 < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x1 of 0.03 and 0.14. Additionally, mixtures at x1 = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x2 = 0.01 in the crystal structure. PMID:21116474

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 g g⁻¹ phenanthrene using a quantitati...

Proteomic analysis of plasma membrane proteins in wheat roots exposed to phenanthrene.

PubMed

Shen, Yu; Du, Jiangxue; Yue, Le; Zhan, Xinhua

2016-06-01

Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and toxic to humans through ingestion of contaminated food crops. PAHs can enter crop roots through proton/PAH symporters; however, to date, the symporter remains unclear. Here we reveal, for the first time, the plasma membrane proteome of Triticum aestivum seedling roots in response to phenanthrene (a model PAH) exposure. Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF-MS and protein database search engines were employed to analyze and identify phenanthrene-responsive proteins. Over 192 protein spots are reproducibly detected in each gel, while 8 spots are differentially expressed under phenanthrene treatment. Phenanthrene induces five up-regulated proteins distinguished as 5-methyltetrahydropteroyltriglutamate-homocysteine methyltransferase 2, enolase, heat shock protein 80-2, probable mediator of RNA polymerase II transcription subunit 37e (heat shock 70-kDa protein 1), and lactoylglutathione lyase. Three proteins identified as adenosine kinase 2, 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1c, and glyceraldehyde-3-phosphate dehydrogenase 3 are down-regulated under exposure to phenanthrene. The up-regulated proteins are related to plant defense response, antioxidant system, and glycolysis. The down-regulated proteins involve the metabolism of high-energy compounds and plant growth. Magnesium, which is able to bind to enolase, can enhance the transport of phenanthrene into wheat roots. Therefore, it is concluded that phenanthrene can induce differential expression of proteins in relation to carbohydrate metabolism, self-defense, and plant growth on wheat root plasma membrane. This study not only provides novel insights into PAH uptake by plant roots and PAH stress responses, but is also a good starting point for further determination and analyses of their functions using genetic and other approaches.

Synthesis and solar-cell applications of novel furanyl-substituted anthracene derivatives

NASA Astrophysics Data System (ADS)

Kivrak, Arif; Er, Ömer Faruk; Kivrak, Hilal; Topal, Yasemin; Kuş, Mahmut; Çamlısoy, Yesim

2017-11-01

At present, novel furanyl-substituted anthracene derivatives; namely 9,10-di(furan-2-yl)anthracene (DFA), 5,5‧-(anthracene-9,10-diyl)bis(furan-2-carbaldehyde) (DAFA) and 2,2‧-((5,5‧-(anthracene-9,10-diyl)bis(furan-5,2-diyl))bis(methanylylidene))dimalononitrile (DCNFA) were designed and synthesized successfully by employing Stille Cross-Coupling, Vilsmeier-Haack and Knoevenagel condensation reactions, respectively. This methodology provides a practical new route for the synthesis of furanyl-substituted anthracene derivatives bearing strong electron-withdrawing groups. The electrochemical and electro-optical properties of these novel furanyl-substituted anthracene derivatives were also examined with strong acceptor-π-donor-π-acceptor interactions. Furthermore, Highest occupied molecular orbital (HOMO), Lowest Unoccupied molecular orbital (LUMO), and band gap (Eg) values were investigated by using spectroscopic methods. Electrochemical and electro-optical properties were calculated and compared to DFA, DAFA and DCNFA. Eg was found as 2.85, 2.71, and 2.33 eV, respectively. Consequently, Organic Solar Cells (OSC) were fabricated to investigate their solar cell performances. The strong electron withdrawing groups did not increase the solar cell performance of furanyl-anthracenes. Surprisingly, DFA was found to exhibit the best OSCs performance (Efficiency = 3.36). As a result, one could note that these novel furanyl-substituted anthracene derivatives are good candidate for the applications of the OSCs. Our results might help in the development of new materials with important electrochemical functions by giving the advantage of designing and further derivatization of new generation small organic molecules for photovoltaic device applications.

Advances of naphthalene degradation in Pseudomonas putida ND6

NASA Astrophysics Data System (ADS)

Song, Fu; Shi, Yifei; Jia, Shiru; Tan, Zhilei; Zhao, Huabing

2018-03-01

Naphthalene is one of the most common and simple polycyclic aromatic hydrocarbons. Degradation of naphthalene has been greatly concerned due to its economic, free-pollution and its fine effect in Pseudomonas putida ND6. This review summarizes the development history of naphthalene degradation, the research progress of naphthalene degrading gene and naphthalene degradation pathway of Pseudomonas putida ND6, and the researching path of this strain. Although the study of naphthalene degradation is not consummate in Pseudomonas putida ND6, there is a potential capability for Pseudomonas putida ND6 to degrade the naphthalene in the further research.

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

PubMed Central

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

2014-01-01

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. PMID:24964867

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

Assessing the environmental impact of phenanthrene in different types of land use based on the binding characteristics with dissolved organic matter.

PubMed

Chen, Xiao-Meng; Zhao, Yue; Ma, Ying-Ying; Zhu, Long-Ji; Yang, Tian-Xue; Wei, Zi-Min; Dong, Ying-Li; Wei, Qing-Bin

2018-01-01

The binding characteristics of phenanthrene with dissolved organic matter (DOM) were studied by the excitation emission matrix fluorescence spectroscopy with parallel factor analysis in four types of land use which derived from forest (F), meadow (M), cropland (C), and greenhouse (G). The results showed that the humification degree and binding characteristics of phenanthrene with DOM were distinct differences in the four soils. The binding capacities of humic-like components with phenanthrene were stronger than those of protein-like components. The log K derived from the Stern-Volmer equation significantly correlated with the humification degree of DOM (p < 0.05) in different types of land use. Besides, correlation analysis demonstrated that the potential binding index (Fk) obtained from the modified Stern-Volmer model was a more accurate parameter to describe the combination degree of DOM with phenanthrene than log K, which presented a decrease order of C > F > M > G. Therefore, the environmental impact of phenanthrene in different types of land use could be assessed deeply based on the Fk and DOM concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of linear alkyl benzene sulfonates (LAS) on the fate of phenanthrene in a model ecosystem (water-lava-plant-air).

PubMed

Jiang, Xia; Jin, Xiang-can; Yan, Chang-zhou; Yediler, Ayfer; Ou, Zi-qing; Kettrup, Antonius

2004-01-01

Advanced closed chamber system was used to study the fate of phenanthrene (3-rings PAHs) in the presence of linear alkylbenzene sulphonates (LAS). The results showed mineralization and metabolism of phenanthrene are fast in the "culture solution-lava-plant-air" model ecological system. The distribution proportions of applied 14C-activity in this simulative ecological system were 41%-45%, 14% to 10% and 1% in plant, lava and culture solution respectively, and 18% to 29%, 11% to 8% recovered in the forms of VOCs and CO2. Main parts of the applied 14C-activity exist in two forms, one is polar metabolites (25%) which mainly distribute in the root (23%), the other is unextractable part (23%) which have been constructed into plant root (8.98%), shoot (0.53%) or bonded to lava (13.2%). The main metabolites of phenanthrene were polar compounds (25% of applied 14C-activity), and small portion of 14C-activity was identified as non-polar metabolites (6% of applied 14C-activity) and apparent phenanthrene (1.91% of applied 14C-activity). Phenanthrene and its metabolites can be taken up through plant roots and translocated to plant shoots. The presence of LAS significantly increased the the concentration of 14C-activity in the plant and production of VOCs, at the same time it decreased the phenanthrene level in the plant and the production of CO2 at the concentration of 200 mg/L.

Spatial Distribution of Bacterial Communities and Phenanthrene Degradation in the Rhizosphere of Lolium perenne L.

PubMed Central

Corgié, S. C.; Beguiristain, T.; Leyval, C.

2004-01-01

Rhizodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is based on the effect of root-produced compounds, known as exudates. These exudates constitute an important and constant carbon source that selects microbial populations in the plant rhizosphere, modifying global as well as specific microbial activities. We conducted an experiment in two-compartment devices to show the selection of bacterial communities by root exudates and phenanthrene as a function of distance to roots. Using direct DNA extraction, PCR amplification, and thermal gradient gel electrophoresis screening, bacterial population profiles were analyzed in parallel to bacterial counts and quantification of phenanthrene biodegradation in three layers (0 to 3, 3 to 6, and 6 to 9 mm from root mat) of unplanted-polluted (phenanthrene), planted-polluted, and planted-unpolluted treatments. Bacterial community differed as a function of the distance to roots, in both the presence and the absence of phenanthrene. In the planted and polluted treatment, biodegradation rates showed a strong gradient with higher values near the roots. In the nonplanted treatment, bacterial communities were comparable in the three layers and phenanthrene biodegradation was high. Surprisingly, no biodegradation was detected in the section of planted polluted treatment farthest from the roots, where the bacterial community structure was similar to those of the nonplanted treatment. We conclude that root exudates and phenanthrene induce modifications of bacterial communities in polluted environments and spatially modify the activity of degrading bacteria. PMID:15184156

Concentration and source identification of polycyclic aromatic hydrocarbons and phthalic acid esters in the surface water of the Yangtze River Delta, China.

PubMed

Zhang, Lifei; Dong, Liang; Ren, Lijun; Shi, Shuangxin; Zhou, Li; Zhang, Ting; Huang, Yeru

2012-01-01

The pollution from polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in the surface water of the rapidly urbanized Yangtze River Delta region was investigated. Fourteen surface water samples were collected in June 2010. Water samples were liquid-liquid extracted using methylene chloride and analyzed by gas chromatography-mass spectrometry. Concentrations of PAHs and PAEs ranged 12.9-638.1 ng/L and 61-28550 ng/L, respectively. Fluoranthene, naphthalene, pyrene, phenanthrene, di-2-ethylhexyl phthalate, and di-n-butyl phthalate were the most abundant compounds in the samples. The water samples were moderately polluted with benzo[a]pyrene according to China's environmental quality standard for surface water. The two highest concentrations of PAHs and PAEs occurred in samples from Taihu Lake, Wuxi City and the western section of Yangchenghu Lake. Potential sources of pollution at S7 were petroleum combustion and the plastics industry, and at Yangchenghu Lake were petroleum combustion and domestic waste. Pollution in samples from the Beijing-Hangzhou Grand Canal originated from diesel engines. There were no obvious sources of pollution for the other water samples. These results can be used as reference levels for future monitoring programs of pollution from PAHs and PAEs.

Chemometric assessment of enhanced bioremediation of oil contaminated soils.

PubMed

Soleimani, Mohsen; Farhoudi, Majid; Christensen, Jan H

2013-06-15

Bioremediation is a promising technique for reclamation of oil polluted soils. In this study, six methods for enhancing bioremediation were tested on oil contaminated soils from three refinery areas in Iran (Isfahan, Arak, and Tehran). The methods included bacterial enrichment, planting, and addition of nitrogen and phosphorous, molasses, hydrogen peroxide, and a surfactant (Tween 80). Total petroleum hydrocarbon (TPH) concentrations and CHEMometric analysis of Selected Ion Chromatograms (SIC) termed CHEMSIC method of petroleum biomarkers including terpanes, regular, diaromatic and triaromatic steranes were used for determining the level and type of hydrocarbon contamination. The same methods were used to study oil weathering of 2 to 6 ring polycyclic aromatic compounds (PACs). Results demonstrated that bacterial enrichment and addition of nutrients were most efficient with 50% to 62% removal of TPH. Furthermore, the CHEMSIC results demonstrated that the bacterial enrichment was more efficient in degradation of n-alkanes and low molecular weight PACs as well as alkylated PACs (e.g. C₃-C₄ naphthalenes, C₂ phenanthrenes and C₂-C₃ dibenzothiophenes), while nutrient addition led to a larger relative removal of isoprenoids (e.g. norpristane, pristane and phytane). It is concluded that the CHEMSIC method is a valuable tool for assessing bioremediation efficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2017-01-01

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

New Findings on Aromatic Compounds' Degradation and Their Metabolic Pathways, the Biosurfactant Production and Motility of the Halophilic Bacterium Halomonas sp. KHS3.

PubMed

Corti Monzón, Georgina; Nisenbaum, Melina; Herrera Seitz, M Karina; Murialdo, Silvia E

2018-04-24

The study of the aromatic compounds' degrading ability by halophilic bacteria became an interesting research topic, because of the increasing use of halophiles in bioremediation of saline habitats and effluents. In this work, we focused on the study of aromatic compounds' degradation potential of Halomonas sp. KHS3, a moderately halophilic bacterium isolated from hydrocarbon-contaminated seawater of the Mar del Plata harbour. We demonstrated that H. sp. KHS3 is able to grow using different monoaromatic (salicylic acid, benzoic acid, 4-hydroxybenzoic acid, phthalate) and polyaromatic (naphthalene, fluorene, and phenanthrene) substrates. The ability to degrade benzoic acid and 4-hydroxybenzoic acid was analytically corroborated, and Monod kinetic parameters and yield coefficients for degradation were estimated. Strategies that may enhance substrate bioavailability such as surfactant production and chemotactic responses toward aromatic compounds were confirmed. Genomic sequence analysis of this strain allowed us to identify several genes putatively related to the metabolism of aromatic compounds, being the catechol and protocatechuate branches of β-ketoadipate pathway completely represented. These features suggest that the broad-spectrum xenobiotic degrader H. sp. KHS3 could be employed as a useful biotechnological tool for the cleanup of aromatic compounds-polluted saline habitats or effluents.

Adsorption of polycyclic aromatic hydrocarbons by graphene and graphene oxide nanosheets.

PubMed

Wang, Jun; Chen, Zaiming; Chen, Baoliang

2014-05-06

The adsorption of naphthalene, phenanthrene, and pyrene onto graphene (GNS) and graphene oxide (GO) nanosheets was investigated to probe the potential adsorptive sites and molecular mechanisms. The microstructure and morphology of GNS and GO were characterized by elemental analysis, XPS, FTIR, Raman, SEM, and TEM. Graphene displayed high affinity to the polycyclic aromatic hydrocarbons (PAHs), whereas GO adsorption was significantly reduced after oxygen-containing groups were attached to GNS surfaces. An unexpected peak was found in the curve of adsorption coefficients (Kd) with the PAH equilibrium concentrations. The hydrophobic properties and molecular sizes of the PAHs affected the adsorption of G and GO. The high affinities of the PAHs to GNS are dominated by π-π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS surfaces. In contrast, the adsorptive sites of GO changed to the carboxyl groups attaching to the edges of GO because the groove regions disappeared and the polar nanosheet surfaces limited the π-π interactions. The TEM and SEM images initially revealed that after loading with PAH, the conformation and aggregation of GNS and GO nanosheets dramatically changed, which explained the observations that the potential adsorption sites of GNS and GO were unusually altered during the adsorption process.

Levels of PAHs in the Waters, Sediments, and Shrimps of Estero de Urias, an Estuary in Mexico, and Their Toxicological Effects

PubMed Central

Jaward, Foday M.; Alegria, Henry A.; Galindo Reyes, Jose G.; Hoare, Armando

2012-01-01

PAHs were measured in water, sediment, and shrimps of Estero de Urias, an estuary in Sinaloa, Mexico, during the rainy and dry seasons, and analyzed for eleven PAHs routinely detected in samples. Phenanthrene was the most dominant congener in the water, sediment, and shrimp samples comprising about 38, 24, and 25%, respectively, of the eleven PAHs detected, followed by pyrene and naphthalene in water and sediment samples, and pyrene and fluorine in the shrimp samples. Total PAH concentrations ranged from 9 to 347 ng/L in water, 27 to 418 ng/g in sediments, and 36 to 498 ng/g in shrimps. The sources of contamination are closely related to human activities such as domestic and industrial discharge, automobile exhausts, and street runoff. High concentrations were also measured during the rainy season and during the first quarter of the year. Toxicity tests were also carried out, exposing fish embryos and juvenile shrimps to some of these PAHs. Fish embryos exposed to PAHs showed exogastrulation, while juvenile shrimps showed significantly lower growth rates than controls. DNA and protein alterations were also observed. These toxicity tests indicate that PAH concentrations measured could be dangerous to some aquatic organisms, particularly during early stages of development. PMID:22997501

Determination of polycyclic aromatic hydrocarbons by four-way parallel factor analysis in presence of humic acid.

PubMed

Yang, Ruifang; Zhao, Nanjing; Xiao, Xue; Yu, Shaohui; Liu, Jianguo; Liu, Wenqing

2016-01-05

There is not effective method to solve the quenching effect of quencher in fluorescence spectra measurement and recognition of polycyclic aromatic hydrocarbons in aquatic environment. In this work, a four-way dataset combined with four-way parallel factor analysis is used to identify and quantify polycyclic aromatic hydrocarbons in the presence of humic acid, a fluorescent quencher and an ubiquitous substance in aquatic system, through modeling the quenching effect of humic acid by decomposing the four-way dataset into four loading matrices corresponding to relative concentration, excitation spectra, emission spectra and fluorescence quantum yield, respectively. It is found that Phenanthrene, pyrene, anthracene and fluorene can be recognized simultaneously with the similarities all above 0.980 between resolved spectra and reference spectra. Moreover, the concentrations of them ranging from 0 to 8μgL(-1) in the test samples prepared with river water could also be predicted successfully with recovery rate of each polycyclic aromatic hydrocarbon between 100% and 120%, which were higher than those of three-way PARAFAC. These results demonstrate that the combination of four-way dataset with four-way parallel factor analysis could be a promising method to recognize the fluorescence spectra of polycyclic aromatic hydrocarbons in the presence of fluorescent quencher from both qualitative and quantitative perspective. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrence and Risk Assessment of PAHs in Surface Sediments from Western Arctic and Subarctic Oceans

PubMed Central

Lin, Yan; Cai, Minggang; Zhang, Jingjing; Zhang, Yuanbiao; Kuang, Weiming; Liu, Lin; Huang, Peng; Ke, Hongwei

2018-01-01

In the fourth Chinese National Arctic Research Expedition (from July to September, 2010), 14 surface sediment samples were collected from the Bering Sea, Chukchi Sea, and Canadian Basin to examine the spatial distributions, potential sources, as well as ecological and health risk assessment of polycyclic aromatic hydrocarbons (PAHs). The ∑PAH (refers to the sum of 16 priority PAHs) concentration range from 27.66 ng/g to 167.48 ng/g (dry weight, d.w.). Additionally, the concentrations of ∑PAH were highest in the margin edges of the Canadian Basin, which may originate from coal combustion with an accumulation of Canadian point sources and river runoff due to the surface ocean currents. The lowest levels occurred in the northern of Canadian Basin, and the levels of ∑PAH in the Chukchi Sea were slightly higher than those in the Being Sea. Three isomer ratios of PAHs (Phenanthrene/Anthracene, BaA/(BaA+Chy), and LMW/HMW) were used to investigate the potential sources of PAHs, which showed the main source of combustion combined with weaker petroleum contribution. Compared with four sediment quality guidelines, the concentrations of PAH are much lower, indicating a low potential ecological risk. All TEQPAH also showed a low risk to human health. Our study revealed the important role of the ocean current on the redistribution of PAHs in the Arctic. PMID:29649142

Numerical evaluation of bioaccumulation and depuration kinetics of PAHs in Mytilus galloprovincialis.

PubMed

Yakan, S D; Focks, A; Klasmeier, J; Okay, O S

2017-01-01

Polycyclic aromatic hydrocarbons (PAHs) are important organic pollutants in the aquatic environment due to their persistence and bioaccumulation potential both in organisms and in sediments. Benzo(a)anthracene (BaA) and phenanthrene (PHE), which are in the priority pollutant list of the U.S. EPA (Environmental Protection Agency), are selected as model compounds of the present study. Bioaccumulation and depuration experiments with local Mediterranean mussel species, Mytilus galloprovincialis were used as the basis of the study. Mussels were selected as bioindicator organisms due to their broad geographic distribution, immobility and low enzyme activity. Bioaccumulation and depuration kinetics of selected PAHs in Mytilus galloprovincialis were described using first order kinetic equations in a three compartment model. The compartments were defined as: (1) biota (mussel), (2) surrounding environment (seawater), and (3) algae (Phaeodactylum tricornutum) as food source of the mussels. Experimental study had been performed for three different concentrations. Middle concentration of the experimental data was used as the model input in order to represent other high and low concentrations of selected PAHs. Correlations of the experiment and model data revealed that they are in good agreement. Accumulation and depuration trend of PAHs in mussels regarding also the durations can be estimated effectively with the present study. Thus, this study can be evaluated as a supportive tool for risk assessment in addition to monitoring studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Hecht, Stephen S; Berg, Jeannette Zinggeler; Hochalter, J Bradley

2009-03-16

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 the 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 microM 8, 24 h 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 nonmutagenic/carcinogenic, these results, if generalizable to other PAH, do not support the widely held assumption that glutathione-S-transferases are important in the detoxification of PAH in humans.

Naphthalene distributions and human exposure in Southern California

NASA Astrophysics Data System (ADS)

Lu, Rong; Wu, Jun; Turco, Richard P.; Winer, Arthur M.; Atkinson, Roger; Arey, Janet; Paulson, Suzanne E.; Lurmann, Fred W.; Miguel, Antonio H.; Eiguren-Fernandez, Arantzazu

The regional distribution of, and human exposure to, naphthalene are investigated for Southern California. A comprehensive approach is taken in which advanced models are linked for the first time to quantify population exposure to the emissions of naphthalene throughout Southern California. Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons found in polluted urban environments, and has been detected in both outdoor and indoor air samples. Exposure to high concentrations of naphthalene may have adverse health effects, possibly causing cancer in humans. Among the significant emission sources are volatilization from naphthalene-containing products, petroleum refining, and combustion of fossil fuels and wood. Gasoline and diesel engine exhaust, with related vaporization from fuels, are found to contribute roughly half of the daily total naphthalene burden in Southern California. As part of this study, the emission inventory for naphthalene has been verified against new field measurements of the naphthalene-to-benzene ratio in a busy traffic tunnel in Los Angeles, supporting the modeling work carried out here. The Surface Meteorology and Ozone Generation (SMOG) airshed model is used to compute the spatial and temporal distributions of naphthalene and its photooxidation products in Southern California. The present simulations reveal a high degree of spatial variability in the concentrations of naphthalene-related species, with large diurnal and seasonal variations as well. Peak naphthalene concentrations are estimated to occur in the early morning hours in the winter season. The naphthalene concentration estimates obtained from the SMOG model are employed in the Regional Human Exposure (REHEX) model to calculate population exposure statistics. Results show average hourly naphthalene exposures in Southern California under summer and winter conditions of 270 and 430 ng m -3, respectively. Exposure to significantly higher concentrations may occur for individuals close to local sources, or in naphthalene "hotspots" revealed by simulations and observations. Such levels of naphthalene exposure may be used to gauge the potential health impacts of long-term naphthalene exposure. Results are also given for the distributions of 1,4-naphthoquinone, a naphthalene reaction product that may have significant health effects.

[Feasibility of using laser-induced fluorescence to detect directly polycyclic aromatic hydrocarbons in soil].

PubMed

Yang, Ren-Jie; Shang, Li-Ping; Bao, Zhen-Bo; He, Jun; Deng, Hu; Liu, Yu-Le

2011-08-01

Abstract In the present paper, a technique of laser-induced fluorescence(LIF)for direct assay of polycyclic aromatic hydrocarbons(PAH) in soil was put forward. The research objective of this article is anthracene. The possibility of using LIF spectra to detect directly anthracene in soil was studied. Anthracene was detected in soil by AvaSpec-3648 Fiber Optic Spectrometer of thermoelectric refrigeration. The authors drew a conclusion that in the range of certain anthracene concentration(0.000 005-0.001 g x g(-1)), the intensity of LIF fluorescence is linear with anthracene concentration in soil, with a regression coefficient of 0. 929. This showed that direct assay of anthracene in soil was feasible by laser-induced fluorescence. The study is important to developing a new analytical technique of quantitative fluorescence detector which can be applied to the analysis of PAH in soil without pretreatment, and is significant to realization of real-time, in-line, in-situ measurement of PAH in soil.

[Effects of naphthalene on soil respiration, nutrients and enzyme activities in the subalpine forest of western Sichuan, China].

PubMed

Yang, Fan; Yang, Wan Qin; Wu, Fu Zhong; Wang, Hui; Lan, Li Ying; Liu, Yu Wei; Guo, Cai Hong; Tan, Bo

2017-06-18

As a biocide to reduce soil and litter faunal populations in field experiments, naphthalene has been widely used in the study of ecological functions of soil fauna, but the non-target effects of naphthalene bring about enormous uncertainty to its application. In order to understand whether there were non-target effects of naphthalene in subalpine forest soil, soil in the subalpine forests of west Qinghai-Tibet Plateau was taken as study object. The short-term responses of soil respiration rate, nutrient content and enzyme activity to naphthalene were studied in microcosms. The results showed that soil respiration rate was significantly suppressed by application of naphthalene within 0-10 days, and then showed a significant promotion effect. Naphthalene significantly affected the dynamics of soil NH 4 + -N and NO 3 - -N contents. With application of naphthalene, the highest contents of NH 4 + -N and NO 3 - -N occurred at the 3rd and 7th day, respectively. But they were observed at the 45th and 52nd day with no-naphthalene, respectively. Moreover, soil dissolved carbon content in the naphthalene microcosms showed a sharp increase and then decrease dynamic at the 3rd day, while small change was detected in the no-naphthalene microcosms. Dissolved nitrogen content in both the naphthalene and no-naphthalene microcosms showed an increase at first and then decreased subsequently during the study period. Similar dynamics were found for the soil enzyme activities in both the naphthalene and no-naphthalene microcosms. The highest activities of urease, nitrate reductase and nitrite reductase in both the naphthalene and no-naphthalene microcosms were at the 45th, 38th and 10th day, respectively. In addition, the interaction of naphthalene treatment and sampling time had significant effects on soil respiration rate, the contents of NH 4 + -N, NO 3 - -N and dissolved nitrogen, but had no significant effects on soil dissolved carbon content, and the activities of invertase, nitrate reductase and nitrite reductase. In a short time, the non-target effect of naphthalene as a biocide to reduce soil fauna abundance might have an important influence on the soil nitrogen cycling in subalpine forest of western Sichuan.

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.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phenanthrene binding by humic acid-protein complexes as studied by passive dosing technique.

PubMed

Zhao, Jian; Wang, Zhenyu; Ghosh, Saikat; Xing, Baoshan

2014-01-01

This work investigated the binding behavior of phenanthrene by humic acids (HA-2 and HA-5), proteins (bovine serum albumin (BSA)), lysozyme and pepsin), and their complexes using a passive dosing technique. All sorption isotherms were fitted well with Freundlich model and the binding capability followed an order of HA-5 > HA-2 > BSA > pepsin > lysozyme. In NaCl solution, phenanthrene binding to HA-BSA complexes was much higher than the sum of binding to individual HA and BSA, while there was no enhancement for HA-pepsin. Positively charged lysozyme slightly lowered phenanthrene binding on both HAs due to strong aggregation of HA-lysozyme complexes, leading to reduction in the number of binding sites. The binding enhancement by HA-BSA was observed under all tested ion species and ionic strengths. This enhancement can be explained by unfolding of protein, reduction of aggregate size and formation of HA-BSA complexes with favorable conformations for binding phenanthrene. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative proteomics reveal the mechanism of Tween80 enhanced phenanthrene biodegradation by Sphingomonas sp. GY2B.

PubMed

Liu, Shasha; Guo, Chuling; Dang, Zhi; Liang, Xujun

2017-03-01

Previous study concerning the effects of surfactants on phenanthrene biodegradation focused on observing the changes of cell characteristics of Sphingomonas sp. GY2B. However, the impact of surfactants on the expression of bacterial proteins, controlling phenanthrene transport and catabolism, remains obscure. To overcome the knowledge gap, comparative proteomic approaches were used to investigate protein expressions of Sphingomonas sp. GY2B during phenanthrene biodegradation in the presence and absence of a nonionic surfactant, Tween80. A total of 23 up-regulated and 19 down-regulated proteins were detected upon Tween80 treatment. Tween80 could regulate ion transport (e.g. H + ) in cell membrane to provide driving force (ATP) for the transmembrane transport of phenanthrene thus increasing its uptake and biodegradation by GY2B. Moreover, Tween80 probably increased GY2B vitality and growth by inducing the expression of peptidylprolyl isomerase to stabilize cell membrane, increasing the abundances of proteins involved in intracellular metabolic pathways (e.g. TCA cycle), as well as decreasing the abundances of translation/transcription-related proteins and cysteine desulfurase, thereby facilitating phenanthrene biodegradation. This study may facilitate a better understanding of the mechanisms that regulate surfactants-enhanced biodegradation of PAHs at the proteomic level. Copyright © 2016 Elsevier Inc. All rights reserved.

Theoretical investigation on the mechanism of NO3 radical-initiated atmospheric reactions of phenanthrene

NASA Astrophysics Data System (ADS)

Zhao, Nan; Shi, Xiangli; Xu, Fei; Zhang, Qingzhu; Wang, Wenxing

2017-07-01

Phenanthrene is a polycyclic aromatic hydrocarbon from fossil fuel combustion with toxic properties. The products arising from atmospheric reaction can be more mutagenic and carcinogenic compared to unmodified phenanthrene, and are therefore important to be studied. The products of the specific NO3-radical reactions with phenanthrene where therefore investigated in this study by means of Density Functional Theory (DFT). The results show that the main products are proposed to be 10-(nitrooxy)-10-hydro-phenanthrene-9-one, 2,2‧-diformylbiphenyl, 9,10-phenanthrenequinone, 9-fluorenone and dibenzopyranone. 10-(nitrooxy)-10-hydro-phenanthrene-9-one and 2,2‧-diformylbiphenyl are classified as first-generation products which are subject to secondary reactions to produce 9,10-phenanthrenequinone, 9-fluorenone and dibenzopyranone. The rate constants of elementary reactions were assessed by Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The atmospheric lifetime of Phe determined by the gas-phase reaction with NO3 is estimated to be 1.8 h, based on the calculated overall rate constant of 3.04 × 10-13 cm3 molecule-1 s-1 at 298 K and 1 atm. Combined with available experimental observation, this work should help to clarify the transformation and potential health risk of Phe in the atmosphere.

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. Copyright © 2010 Elsevier B.V. All rights reserved.

Isolation and Characterization of Phenanthrene Degrading Bacteria from Diesel Fuel-Contaminated Antarctic Soils

PubMed Central

Gran-Scheuch, Alejandro; Fuentes, Edwar; Bravo, Denisse M.; Jiménez, Juan Cristobal; Pérez-Donoso, José M.

2017-01-01

Antarctica is an attractive target for human exploration and scientific investigation, however the negative effects of human activity on this continent are long lasting and can have serious consequences on the native ecosystem. Various areas of Antarctica have been contaminated with diesel fuel, which contains harmful compounds such as heavy metals and polycyclic aromatic hydrocarbons (PAH). Bioremediation of PAHs by the activity of microorganisms is an ecological, economical, and safe decontamination approach. Since the introduction of foreign organisms into the Antarctica is prohibited, it is key to discover native bacteria that can be used for diesel bioremediation. By following the degradation of the PAH phenanthrene, we isolated 53 PAH metabolizing bacteria from diesel contaminated Antarctic soil samples, with three of these isolates exhibiting a high phenanthrene degrading capacity. In particular, the Sphingobium xenophagum D43FB isolate showed the highest phenanthrene degradation ability, generating up to 95% degradation of initial phenanthrene. D43FB can also degrade phenanthrene in the presence of its usual co-pollutant, the heavy metal cadmium, and showed the ability to grow using diesel-fuel as a sole carbon source. Microtiter plate assays and SEM analysis revealed that S. xenophagum D43FB exhibits the ability to form biofilms and can directly adhere to phenanthrene crystals. Genome sequencing analysis also revealed the presence of several genes involved in PAH degradation and heavy metal resistance in the D43FB genome. Altogether, these results demonstrate that S. xenophagum D43FB shows promising potential for its application in the bioremediation of diesel fuel contaminated-Antarctic ecosystems. PMID:28894442

Fungal biodegradation of anthracene-polluted cork: A comparative study.

PubMed

Jové, Patrícia; Olivella, Maria À; Camarero, Susana; Caixach, Josep; Planas, Carles; Cano, Laura; De Las Heras, Francesc X

2016-01-01

The efficiency of cork waste in adsorbing aqueous polycyclic aromatic hydrocarbons (PAHs) has been previously reported. Biodegradation of contaminated cork using filamentous fungi could be a good alternative for detoxifying cork to facilitate its final processing. For this purpose, the degradation efficiency of anthracene by three ligninolytic white-rot fungi (Phanerochaete chrysosporium, Irpex lacteus and Pleurotus ostreatus) and three non-ligninolytic fungi which are found in the cork itself (Aspergillus niger, Penicillium simplicissimum and Mucor racemosus) are compared. Anthracene degradation by all fungi was examined in solid-phase cultures after 0, 16, 30 and 61 days. The degradation products of anthracene by P. simplicissimum and I. lacteus were also identified by GC-MS and a metabolic pathway was proposed for P. simplicissimum. Results show that all the fungi tested degraded anthracene. After 61 days of incubation, approximately 86%, 40%, and 38% of the initial concentration of anthracene (i.e., 100 µM) was degraded by P. simplicissimum, P. chrysosporium and I. lacteus, respectively. The rest of the fungi degraded anthracene to a lesser extent (<30%). As a final remark, the results obtained in this study indicate that P. simplicissimum, a non-ligninolytic fungi characteristic of cork itself, could be used as an efficient degrader of PAH-contaminated cork.

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 complex interactions in soils for bioremediation applications.

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 complex interactions in soils for bioremediation applications. PMID:25222697

Enrichment and identification of naphthalene-degrading bacteria from the Persian Gulf.

PubMed

Hassanshahian, Mehdi; Boroujeni, Negar Amini

2016-06-15

Naphthalene is a ubiquitous pollutant of the marine environment, and naphthalene biodegradation has been receiving constant scientific consideration. For cleanup of aromatic contaminated sites, bioremediation methods are considered as economical and safe approaches for the marine environment. The aims of this research are isolation and characterization of naphthalene-degrading bacteria from some marine samples of the Persian Gulf. Fifty four naphthalene-degrading bacteria were isolated from marine samples (sediment and seawater) that are enriched in ONR7a medium with naphthalene as the only carbon source. Some screening tests such as growth at high concentration of naphthalene, bioemulsifier production and surface hydrophobicity were done to select the best and prevalent strains for naphthalene degradation. Determination of the nucleotide sequence of the gene encoding for 16S rRNA shows that these isolated strains belong to these genera: Shewanella, Salegentibacter, Halomonas, Marinobacter, Oceanicola, Idiomarina and Thalassospira. These strains can degrade half of the percentage of naphthalene in 10days of incubation. This research is the first report on isolation of these genera from the Persian Gulf as naphthalene-degrader. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

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.

Synthesis and photophysical characterizations of thermal-stable naphthalene benzimidazoles.

PubMed

Erten-Ela, Sule; Ozcelik, Serdar; Eren, Esin

2011-07-01

Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence quantum yields. Fluorophore-solvent interactions are also investigated using Lippert-Mataga equation for naphthalimides and naphthalene benzimidazoles. Thermal stabilities of naphthalene benzimidazoles are better than naphthalimides due to increased aromaticity. The experimental E(LUMO) levels of naphthalene benzimidazoles are found to be between 3.15 and 3.28 eV. Therefore, naphthalene benzimidazole derivatives consisting of anchoring groups are promising materials in organic dye sensitized solar cells. © Springer Science+Business Media, LLC 2011

Acute intravascular hemolysis and methemoglobinemia following naphthalene ball poisoning.

PubMed

Kapoor, Rajan; Suresh, P; Barki, Satish; Mishra, Mayank; Garg, M K

2014-09-01

Naphthalene (C10H8) is a natural component of fossil fuels such as petroleum, diesel and coal. The common consumer products made from naphthalene are moth repellents, in the form of mothballs or crystals, and toilet deodorant blocks. Major toxic effects of naphthalene are due to precipitation of acute intravascular hemolysis. Very few cases of naphthalene poisoning and its effects have been reported from India. We report a case of accidental naphthalene poisoning, who presented with intravascular hemolysis and methemoglobinemia.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bu, Lintao; Nimlos, Mark R.; Robichaud, David J.

Hierarchical mesoporous zeolites exhibit higher catalytic activities and longer lifetime compared to the traditional microporous zeolites due to improved diffusivity of substrate molecules and their enhanced access to the zeolite active sites. Understanding diffusion of biomass pyrolysis vapors and their upgraded products in such materials is fundamentally important during catalytic fast pyrolysis (CFP) of lignocellulosic biomass, since diffusion makes major contribution to determine shape selectivity and product distribution. However, diffusivities of biomass relevant species in hierarchical mesoporous zeolites are poorly characterized, primarily due to the limitations of the available experimental technology. In this work, molecular dynamics (MD) simulations are utilizedmore » to investigate the diffusivities of several selected coke precursor molecules, benzene, naphthalene, and anthracene, in hierarchical mesoporous H-ZSM-5 zeolite. The effects of temperature and size of mesopores on the diffusivity of the chosen model compounds are examined. The simulation results demonstrate that diffusion within the microspores as well as on the external surface of mesoporous H-ZSM-5 dominates only at low temperature. At pyrolysis relevant temperatures, mass transfer is essentially conducted via diffusion along the mesopores. Additionally, the results illustrate the heuristic diffusion model, such as the extensively used Knudsen diffusion, overestimates the diffusion of bulky molecules in the mesopores, thus making MD simulation a powerful and compulsory approach to explore diffusion in zeolites.« less

Mechanical Properties of Stable Glasses Using Nanoindentation

NASA Astrophysics Data System (ADS)

Wolf, Sarah; Liu, Tianyi; Jiang, Yijie; Ablajan, Keyume; Zhang, Yue; Walsh, Patrick; Turner, Kevin; Fakhraai, Zahra

Glasses with enhanced stability over ordinary, liquid quenched glasses have been formed via the process of Physical Vapor Deposition (PVD) by using a sufficiently slow deposition rate and a substrate temperature slightly below the glass transition temperature. These stable glasses have been shown to exhibit higher density, lower enthalpy, and better kinetic stability over ordinary glass, and are typically optically birefringent, due to packing and orientational anisotropy. Given these exceptional properties, it is of interest to further investigate how the properties of stable glasses compare to those of ordinary glass. In particular, the mechanical properties of stable glasses remain relatively under-investigated. While the speed of sound and elastic moduli have been shown to increase with increased stability, little is known about their hardness and fracture toughness compared to ordinary glasses. In this study, glasses of 9-(3,5-di(naphthalen-1-yl)phenyl)anthracene were deposited at varying temperatures relative to their glass transition temperature, and their mechanical properties measured by nanoindentation. Hardness and elastic modulus of the glasses were compared across substrate temperatures. After indentation, the topography of these films were studied using Atomic Force Microscopy (AFM) in order to further compare the relationship between thermodynamic and kinetic stability and mechanical failure. Z.F. and P.W. acknowledge funding from NSF(DMREF-1628407).

Adsorption of polycyclic aromatic hydrocarbons on graphene oxides and reduced graphene oxides.

PubMed

Sun, Yubing; Yang, Shubin; Zhao, Guixia; Wang, Qi; Wang, Xiangke

2013-11-01

Graphene has attracted increasing attention in multidisciplinary studies because of its unique physical and chemical properties. Herein, the adsorption of polycyclic aromatic hydrocarbons (PAHs), such as naphthalene (NAP), anthracene (ANT), and pyrene (PYR), on reduced graphene oxides (rGOs) and graphene oxides (GOs) as a function of pH, humic acid (HA), and temperature were elucidated by means of a batch technique. For comparison, nonpolar and nonporous graphite were also employed in this study. The increasing of pH from 2 to 11 did not influence the adsorption of PAHs on rGOs, whereas the suppressed adsorption of NAP on rGOs was observed both in the presence of HA and under high-temperature conditions. Adsorption isotherms of PAHs on rGOs were in accordance with the Polanyi-Dubinin-Ashtahhov (PDA) model, providing evidence that pore filling and flat surface adsorption were involved. The saturated adsorbed capacities (in mmol g(-1)) of rGOs for PAHs calculated from the PDA model significantly decreased in the order of NAP>PYR>ANT, which was comparable to the results of theoretical calculations. The pore-filling mechanism dominates the adsorption of NAP on rGOs, but the adsorption mechanisms of ANT and PYR on rGOs are flat surface adsorption. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, photophysical properties, and computational studies of four-coordinate copper(I) complexes based on benzimidazolylidene N-heterocyclic carbene (NHC) ligands bearing aryl substituents

NASA Astrophysics Data System (ADS)

Xu, Shengxian; Wang, Jinglan; Liu, Shaobo; Zhao, Feng; Xia, Hongying; Wang, Yibo

2018-02-01

Three four-coordinate N-heterocyclic carbene (NHC) copper(I) complexes, [Cu(Ph-BenIm-Py)(POP)]PF6 (1), [Cu(Naph-BenIm-Py)(POP)]PF6 (2), and [Cu(Anthr-BenIm-Py)(POP)]PF6 (3) (Ph-BenIm-Py = 3-benzyl-1-(pyridin-2-yl)-1H-benzimidazolylidene, Naph-BenIm-Py = 3-(naphthalen-2-yl-1-(pyridin-2-yl)-1H- benzimidazolylidene, Anthr-BenIm-Py = 3-(anthracen-9-yl)-1-(pyridin-2-yl)-1H-benzimidazolylidene, and POP = bis[2-diphenylphosphino]-phenyl)ether) have been synthesized and characterized. The different aryl substituents (phenyl, naphthyl, and anthracyl groups) were introduced into NHC ligands and the corresponding photophysical properties of the complexes were systematically investigated. The absorption spectra of all NHCsbnd Cu(I) complexes show a characteristic feature of metal-to-ligand charge transfer (MLCT) in the lower-energy region. Complex 1 exhibited good photoluminescence (PL) properties companying with the high quantum yields and long excited-state lifetimes, whereas 2 and 3 with naphthyl and anthracyl groups show the low PL efficiency caused by the strong π-π stacking interactions. Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were employed to rationalize the photophysical properties of the NHCsbnd Cu(I) complexes.

Elaborately Tuning Intramolecular Electron Transfer Through Varying Oligoacene Linkers in the Bis(diarylamino) Systems

PubMed Central

Zhang, Jing; Chen, Zhao; Yang, Lan; Pan, Fang-Fang; Yu, Guang-Ao; Yin, Jun; Liu, Sheng Hua

2016-01-01

The research efforts on oligoacene systems are still relatively limited mainly due to the synthetic challenge and the extreme instability of longer acenes. Herein, these two issues have been overcome through elaborative modification and the stable pentacene species has been successfully synthesized. Additionally, a series of bis(diarylamino) compounds linked by variable-length oligoacene bridges ranging from one to five fused rings (benzene (1a), naphthalene (1b), anthracene (1c), tetracene (1d) and pentacene (1e)) have been prepared to probe the effect of the extent of π-conjugation on the electron transfer properties. Compound 1c exhibits a high planarity between the anthracyl bridge and the two nitrogen cores and the molecular packing shows a two-dimensional herringbone characteristic. Combined studies based on electrochemistry and spectroelectrochemistry demonstrate that (i) the electronic coupling across the oligoacene linkers between two diarylamine termini exponentially decrease with a moderate attenuation constant (β) of 0.14 Å−1 in these length-modulated systems and (ii) the associated radical cations [1a]+–[1e]+ are classified as the class II Robin–Day mixed-valence systems. Furthermore, density functional theory (DFT) calculations have been conducted to gain insight into the nature of electron transfer processes in these oligoacene systems. PMID:27805023

Raman and surface enhanced Raman scattering study of the orientation of cruciform 9,10-anthracene thiophene and furan derivatives deposited on a gold colloidal surface

NASA Astrophysics Data System (ADS)

Muñoz-Pérez, J.; Leyton, P.; Paipa, C.; Soto, J. P.; Brunet, J.; Gómez-Jeria, J. S.; Campos-Vallette, M. M.

2016-10-01

The 9,10-di(thiophen-2-yl)anthracene (TAT), 9,10-di(furan-2-yl)anthracene (FAF) and 2-[(10-(thiophen-2-yl)anthracen-9-yl)]furan (TAF) cruciform molecular systems were synthesized using one-step coupling reactions and structurally characterized via Raman, infrared, 1H NMR, 13C NMR and mass spectroscopies. The orientation of the analytes on a gold colloidal surface was inferred from a surface-enhanced Raman scattering (SERS) study. The metal surface interaction was driven by the S and O atoms of the thiophene and furan α-substituents, and the plane of the anthracene fragment remained parallel to the surface. Theoretical calculations based on a simplified molecular model for the analyte-surface interaction provide a good representation of the experimental data.

Biodegradability of nonaqueous-phase liquids affects the mineralization of phenanthrene in soil because of microbial competition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrison, D.E.; Alexander, M.

1997-08-01

A study was conducted to determine the effects of biodegradability of nonaqueous-phase liquids (NAPLs) and microbial competition on the biodegradation in soil of a constituent of the NAPLs. The rates of mineralization of phenanthrene dissolved in 8 mg of 2,2,4,4,6,8,8-heptamethylnonane (HMN), di(2-ethylhexyl) phthalate (DEHP), or pristane per g of soil were faster than the rates when the compound was dissolved in hexadecane or dodecane. Addition of inorganic N and P to the soil increased the mineralization rate in the first two but not the last two NAPLs. N and P addition did not enhance mineralization of phenanthrene when added inmore » 500 {micro}g of hexadecane, pristane, or HMN per g of soil. Hexadecane was rapidly degraded, pristane was slowly metabolized, DEHP was still slower, and HMN was not mineralized in the test period. Mixing the soil stimulated mineralization of phenanthrene dissolved in HMN but not in hexadecane. Mineralization of phenanthrene dissolved in HMN was the same if the gas phase contained 21%, 2.1%, or traces of O{sub 2}. In contrast, the biodegradation of phenanthrene dissolved in hexadecane, although the same at 21 and 2.1% O{sub 2}, was not observed if traces of O{sub 2} were present. The mineralization was slower in unshaken soil-water mixtures if phenanthrene was added in hexadecane than in HMN or pristane, but the rates with the 3 NAPLs were increased by shaking the suspensions. The authors suggest that the biodegradability of major components of NAPLs and microbial competition for N, P, or O{sub 2} will have a major impact on the rate of transformation of minor constituents of NAPLs.« less

Molecular modelling investigations on the possibility of phenanthrene dimers to be the primary nuclei of soot

NASA Astrophysics Data System (ADS)

Wei, Mingrui; Wu, Sheng; Li, Fan; Zhang, Dongju; Zhang, Tingting; Guo, Guanlun

2017-11-01

Pyrene dimerisation was successfully used to model the beginning of soot nucleation in some simulation models. However, the quantum mechanics (QM) calculations proved that the binding energy of a PAH dimer with three six-member rings was similar to that of a pyrene dimer. Meanwhile, the high concentration of phenanthrene at flame conditions indicated high probability of collisions among them. The small difference of the binding energy and high concentration indicated that PAHs structurally smaller than pyrene also could be involved in soot inception. Hence, binary collisions of phenanthrene were simulated to find out whether phenanthrene dimers can serve as soot primary nuclei or not by using non-equilibrium molecular dynamics (MD). Three temperatures, six collision orientations and 155 initial translational velocities (ITVs) were considered. The results indicated that the number of dimers with lifetime over 10 ps which can serve as soot nuclei decreased from 52 at 1000 K to 17 at 1600 K, and further to 6 at 2400 K, which means that low temperature was more favourable for phenanthrene to form soot nuclei. Meanwhile, no soot nuclei were formed at the high velocity region (HVR), compared to 43 and 9 at low and middle velocity regions (LVR and MVR), respectively, when temperature was 1000 K. Also, no soot nuclei were formed at HVR when the temperature was raised to 1600 K and 2400 K. This indicated that HVR was unfavourable for phenanthrene to form soot nuclei. The results computationally further illustrated that small PAHs such as phenanthrene could serve as soot primary nuclei, since they have similar mole fractions in some flames. This may be useful for future soot simulation models.

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. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic absorption spectroscopy of matrix-isolated polycyclic aromatic hydrocarbon cations. II. The phenanthrene cation (C14H10+) and its 1-methyl derivative

NASA Technical Reports Server (NTRS)

Salama, F.; Joblin, C.; Allamandola, L. J.

1994-01-01

The ultraviolet, visible, and near infrared absorption spectra of phenanthrene (C14H10), 1-methylphenanthrene [(CH3)C14H9], and their radical ions [C14H10+; (CH3)C14H9+], formed by vacuum-ultraviolet irradiation, were measured in neon matrices at 4.2 K. The associated vibronic band systems and their spectroscopic assignments are discussed. The oscillator strengths were calculated for the phenanthrene ion and found lower than the theoretical predictions. This study presents the first spectroscopic data for phenanthrene and its methyl derivative trapped in a neon matrix where the perturbation of the isolated species by its environment is minimum; a condition crucial to astrophysical applications.

An In Silico Study on the Isomers of Pentacene: The Case for Air-Stable and Alternative C22H14 Acenes for Organic Electronics.

PubMed

Jones, Leighton; Lin, Long

2017-04-13

Pentacene is one of the most investigated candidates for organic thin film transistor (OTFT) applications over the last few decades even though it unstable in air (E g = 1.80 eV), owing in part to its planar nature and high charge-transfer mobilities as both a single crystal (35 cm 2 V -1 s -1 ) and as a thin-film (3.0 cm 2 V -1 s -1 ). Until now, picene is the only isomer of pentacene to be investigated for organic electronic applications, due to its greater stability (E g = 4.21 eV) and high-charge transfer mobility (3.0 cm 2 V -1 s -1 ); even benefiting from oxygen doping. In the present study, a total of 12 fused-ring isomers (including pentacene, picene and ten other structures) of the formula C 22 H 14 were analyzed and investigated for their electronic and optical properties for worth in OTFT applications. We screened several pure and hybrid DFT functionals against the experimental frontier molecular orbitals (FMOs) of pentacene, then deployed Marcus Theory, Koopmans' Theorem and Green's function with the P3 electron propagator variant, for the internal hole reorganization energy, the hole transfer integral (via the "splitting-in-dimer method" at d = 3.0, 3.5, and 4.0 Å), the charge transfer rate constant, and vertical ionization energies. Using these as a basis, we studied pentacene's isomers and found that the four nonplanar structures, namely, benzo[g]chrysene (3), naphtho[c]phenanthrene (7), benzo[c]chrysene (11) and dibenzo[c,c']phenthrene (12), are (I) more stable than pentacene, by up to 2 eV, and (II) have relatively similar ionization energies (7.5-7.6 eV) to those of picene's experimental value (7.51 eV). The largest charge transfer rates at 3.5 Å dimer separations were given by the isomers benzo[b]chrysene 4, naphtha[c]phenanthrene 7, dibenzo[a,c]anthracene 8 and benzo[a]tetracene 10 and found to be 2.92, 1.72, 1.30, and 3.09 × 10 14 s -1 respectively. In comparison to that of pentacene (K CT = 3.97 × 10 14 s -1 ), these unusual isomers are thus promising air-stable and alternative candidates for organic electronic applications.

Sulfate-Reducing Naphthalene Degraders Are Picky Eaters.

PubMed

Wolfson, Sarah J; Porter, Abigail W; Kerkhof, Lee J; McGuinness, Lora M; Prince, Roger C; Young, Lily Y

2018-06-25

Polycyclic aromatic hydrocarbons (PAHs) are common organic contaminants found in anoxic environments. The capacity for PAH biodegradation in unimpacted environments, however, has been understudied. Here we investigate the enrichment, selection, and sustainability of a microbial community from a pristine environment on naphthalene as the only amended carbon source. Pristine coastal sediments were obtained from the Jacques Cousteau National Estuarine Research Reserve in Tuckerton, New Jersey, an ecological reserve which has no direct input or source of hydrocarbons. After an initial exposure to naphthalene, primary anaerobic transfer cultures completely degraded 500 µM naphthalene within 139 days. Subsequent transfer cultures mineralized naphthalene within 21 days with stoichiometric sulfate loss. Enriched cultures efficiently utilized only naphthalene and 2-methylnaphthalene from the hydrocarbon mixtures in crude oil. To determine the microorganisms responsible for naphthalene degradation, stable isotope probing was utilized on cultures amended with fully labeled 13 C-naphthalene as substrate. Three organisms were found to unambiguously synthesize 13 C-DNA from 13 C-naphthalene within 7 days. Phylogenetic analysis revealed that 16S rRNA genes from two of these organisms are closely related to the known naphthalene degrading isolates NaphS2 and NaphS3 from PAH-contaminated sites. A third 16S rRNA gene was only distantly related to its closest relative and may represent a novel naphthalene degrading microbe from this environment.

Biochemical and genotoxic response of naphthalene to fingerlings of milkfish Chanos chanos.

PubMed

Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M

2013-09-01

The present study investigated the acute toxicity, sub-lethal toxicity and biochemical response of naphthalene in fingerlings of milkfish Chanos chanos. The 96 h acute toxicity LC50 values for C. chanos exposed to naphthalene was 5.18 μg l(-1). The estimated no observed effect concentration and lowest observed effect concentration values for naphthalene in C. chanos were 0.42 and 0.69 μg l(-1) respectively for 30 days. The estimated maximum allowable toxicant concentration for naphthalene was 0.53 μg l(-1). Biochemical enzyme markers such as lipid peroxidation, catalase, glutathione S transferase and reduced glutathione were measured in gills and liver tissues of C. chanos exposed to sub-lethal concentrations of naphthalene. Fluctuation in lipid peroxidation and catalase level suggests that naphthalene concentrations play a vital role in induction of oxidative stress in fish. Induction of reduced glutathione level and inhibition of glutathione S-transferase level was observed in naphthalene exposed C. chanos suggesting that there may be enhanced oxidative damage due to free radicals. Increasing concentration increases in number of nuclear abnormalities. The formation of micronuclei and binucleated micronuclei induction by naphthalene confirm its genotoxic potential. The highest levels of DNA damage (% tail length) were observed at 1.24 μg l(-1) of naphthalene. The study suggests that biochemical enzymes, nuclear abnormalities and DNA damage index can serve as a biological marker for naphthalene contamination.

Naphthalene and Naphthoquinone: Distributions and Human Exposure in the Los Angeles Basin

NASA Astrophysics Data System (ADS)

Lu, R.; Wu, J.; Turco, R.; Winer, A. M.; Atkinson, R.; Paulson, S.; Arey, J.; Lurmann, F.

2003-12-01

Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons (PAHs). Naphthalene is found primarily in the gas-phase and has been detected in both outdoor and indoor samples. Evaporation from naphthalene-containing products (including gasoline), and during refining operations, are important sources of naphthalene in air. Naphthalene is also emitted during the combustion of fossil fuels and wood, and is a component of vehicle exhaust. Exposure to high concentrations of naphthalene can damage or destroy red blood cells, causing hemolytic anemia. If inhaled over a long period of time, naphthalene may cause kidney and liver damage, skin allergy and dermatitis, cataracts and retinal damage, as well as attack the central nervous system. Naphthalene has been found to cause cancer as a result of inhalation in animal tests. Naphthoquinones are photooxidation products of naphthalene and the potential health effects of exposure to these quinones are a current focus of research. We are developing and applying models that can be used to assess human exposure to naphthalene and its photooxidation products in major air basins such as California South Coast Air Basin (SoCAB). The work utilizes the Surface Meteorology and Ozone Generation (SMOG) airshed model, and the REgional Human EXposure (REHEX) model, including an analysis of individual exposure. We will present and discuss simulations of basin-wide distributions of, and human exposures to, naphthalene and naphthoquinone, with emphasis on the uncertainties in these estimates of atmospheric concentrations and human exposure. Regional modeling of pollutant sources and exposures can lead to cost-effective and optimally health-protective emission control strategies.

High levels of PAH-metabolites in urine of e-waste recycling workers from Agbogbloshie, Ghana.

PubMed

Feldt, Torsten; Fobil, Julius N; Wittsiepe, Jürgen; Wilhelm, Michael; Till, Holger; Zoufaly, Alexander; Burchard, Gerd; Göen, Thomas

2014-01-01

The informal recycling of electronic waste (e-waste) is an emerging source of environmental pollution in Africa. Among other toxins, polycyclic aromatic hydrocarbons (PAHs) are a major health concern for exposed individuals. In a cross-sectional study, the levels of PAH metabolites in the urine of individuals working on one of the largest e-waste recycling sites of Africa, and in controls from a suburb of Accra without direct exposure to e-waste recycling activities, were investigated. Socioeconomic data, basic health data and urine samples were collected from 72 exposed individuals and 40 controls. In the urine samples, concentrations of the hydroxylate PAH metabolites (OH-PAH) 1-hydroxyphenanthrene (1-OH-phenanthrene), the sum of 2- and 9-hydroxyphenanthrene (2-/9-OH-phenanthrene), 3-hydroxyphenanthrene (3-OH-phenanthrene), 4-hydroxyphenanthrene (4-OH-phenanthrene) and 1-hydroxypyrene (1-OH-pyrene), as well as cotinine and creatinine, were determined. In the exposed group, median urinary concentrations were 0.85 μg/g creatinine for 1-OH-phenanthrene, 0.54 μg/g creatinine for 2-/9-OH-phenanthrene, 0.99 μg/g creatinine for 3-OH-phenanthrene, 0.22 μg/g creatinine for 4-OH-phenanthrene, and 1.33 μg/g creatinine for 1-OH-pyrene, all being significantly higher compared to the control group (0.55, 0.37, 0.63, 0.11 and 0.54 μg/g creatinine, respectively). Using a multivariate linear regression analysis including sex, cotinine and tobacco smoking as covariates, exposure to e-waste recycling activities was the most important determinant for PAH exposure. On physical examination, pathological findings were rare, but about two thirds of exposed individuals complained about cough, and one quarter about chest pain. In conclusion, we observed significantly higher urinary PAH metabolite concentrations in individuals who were exposed to e-waste recycling compared to controls who were not exposed to e-waste recycling activities. The impact of e-waste recycling on exposure to environmental toxins and health of individuals living in the surroundings of e-waste recycling sites warrant further investigation. © 2013 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schachtl, Eva; Yoo, Jong Suk; Gutiérrez, Oliver Y.

The reaction network and elementary steps of the hydrogenation of phenanthrene are explored on parent and Ni-promoted MoS2/c-Al2O3. Two pathways were identified, i.e., Path 1: Phenanthrene _ 9,10-dihydrophenanthrene (DiHPhe)?1,2,3,4,4a,9,10,10a-octahydro-phenanthrene (asymOHPhe), and Path 2: Phenanthrene ?1,2,3,4-tetrahydrophenanthrene (TetHPhe)?1,2,3,4,5,6,7,8-octahydrophenan threne. The steps TetHPhe?asymOHPhe (hydrogenation), and DiHPhe?TetHPhe (hydrogenationisomerization) become notable at phenanthrene conversions above 20%. The reaction preferentially proceeds via Path 1 (90% selectivity) on MoS2/Al2O3. Ni promotion (Ni/(Ni + Mo) molar ratio of 0.3 at the edges on MoS2) increases the hydrogenation activity per active edge twofold and leads to 50% selectivity to both pathways. The reaction orders in H2 vary from _0.8more » on MoS2/Al2O3 to _1.2 on Ni-MoS2/Al2O3, whereas the reaction orders in phenanthrene (_0.6) hardly depend on Ni promotion. The reaction orders in H2S are zero on MoS2/Al2O3 and slightly negative on Ni-MoS2/Al2O3. DFT calculations indicate that phenanthrene is preferentially adsorbed parallel to the basal planes, while H is located at the edges perpendicular to the basal planes. Theory also suggests that Ni atoms, incorporated preferentially on the S-edges, increase the stability of hydrogenated intermediates. Hydrogenation of phenanthrene proceeds through quasi-equilibrated adsorption of the reactants followed by consecutive addition of hydrogen pairs to the adsorbed hydrocarbon. The rate determining steps for the formation of DiHPhe and TetHPhe are the addition of the first and second hydrogen pair, respectively. The concentration of SH groups (activated H at the edges) increases with Ni promotion linearly correlating the rates of Path 1 and Path 2, albeit with different functions. The enhancing effect of Ni on Path 2 is attributed to accelerated hydrogen addition to adsorbed hydrocarbons without important changes in their coverages.« less

Modeling the preferred shapes of polyamine transporter ligands and dihydromotuporamine-C mimics: shovel versus hoe.

PubMed

Breitbeil, Fred; Kaur, Navneet; Delcros, Jean-Guy; Martin, Bénédicte; Abboud, Khalil A; Phanstiel, Otto

2006-04-20

Preferred conformers generated from motuporamine and anthracene-polyamine derivatives provided insight into the shapes associated with polyamine transporter (PAT) recognition and potentially dihydromotuporamine C (4a) bioactivity. Molecular modeling revealed that N(1)-(anthracen-9-ylmethyl)-3,3-triamine (6a), N(1)-(anthracen-9-ylmethyl)-4,4-triamine (6b), N(1)-(anthracen-9-ylmethyl)-N(1)-ethyl-3,3-triamine (7a), N(1)-(anthracen-9-ylmethyl)-N(1)-ethyl-4,4-triamine (7b), and 4a all preferred a hoe motif. This hoe shape was defined by the all-anti polyamine shaft extending above the relatively flat, appended ring system. The hoe geometry was also inferred by the (1)H NMR spectrum of the free amine of 7a (CDCl(3)), which showed a strong shielding effect of the anthracene ring on the chemical shifts associated with the appended polyamine chain. This shielding effect was found to be independent over a broad concentration range of 7a, which also supported an intramolecular phenomenon. The degree of substitution at the N(1)-position seems to be an important determinant of both the molecular shape preferences and biological activity of anthracenylmethyl-polyamine conjugates.

Fabrication and characterization of anthracene thin films for wide-scale organic optoelectronic applications based on linear/nonlinear analyzed optical dispersion parameters

NASA Astrophysics Data System (ADS)

Nawar, Ahmed M.; Yahia, I. S.

2017-08-01

This research work is devoted to studying the linear and nonlinear optical properties of anthracene thin films. For the first time, the fabrication of nanocrystalline anthracene films is presented by using the thermal evaporation conventional technique. All the studied anthracene films exhibit monoclinic crystal structure with dominant preferred orientation along the (001) plane in accordance with X-ray diffraction analysis. The average crystalline size and the strain parameter were calculated and found to be ≈ 14 nm and 42 lines2. nm, respectively. The transparency of the fabricated anthracene films is high (>80%) from the end of the visible to the near-infrared region at 1500 nm, after that; it reaches to 87%. The characteristic behavior, analysis of refractive index and absorption coefficient based on the measured spectrophotometric data of the transmittance and reflectance spectra. The transition is allowed one and the evaluated optical band gap ∼3.1 eV with energy tail ∼105 meV. The dispersion curves of the refractive index were found to follow the Wemple-DiDomenico model. The static optical dielectric constant was found to be 2.592. The molecular polarizability of anthracene thin films presented and its value ∼56.58 (Å)3. A simple spectroscopic method is used to characterize and estimate the nonlinear optical susceptibilities. Thermal evaporation technology could be useful to fabricate blue OLED and window film in photodetector devices based-anthracene films.

Construction of energy transfer pathways self-assembled from DNA-templated stacks of anthracene.

PubMed

Iwaura, Rika; Yui, Hiroharu; Someya, Yuu; Ohnishi-Kameyama, Mayumi

2014-01-05

We describe optical properties of anthracene stacks formed from single-component self-assembly of thymidylic acid-appended anthracene 2,6-bis[5-(3'-thymidylic acid)pentyloxy] anthracene (TACT) and the binary self-assembly of TACT and complementary 20-meric oligoadenylic acid (TACT/dA20) in an aqueous buffer. UV-Vis and emission spectra for the single-component self-assembly of TACT and the binary self-assembly of TACT/dA20 were very consistent with stacked acene moieties in both self-assemblies. Interestingly, time-resolved fluorescence spectra from anthracene stacks exhibited very different features of the single-component and binary self-assemblies. In the single-component self-assembly of TACT, a dynamic Stokes shift (DSS) and relatively short fluorescence lifetime (τ=0.35ns) observed at around 450nm suggested that the anthracene moieties were flexible. Moreover, a broad emission at 530nm suggested the formation of an excited dimer (excimer). In the binary self-assembly of TACT/dA20, we detected a broad, red-shifted emission component at 534nm with a lifetime (τ=0.4ns) shorter than that observed in the TACT single-component self-assembly. Combining these results with the emission spectrum of the binary self-assembly of TACT/5'-HEX dA20, we concluded that the energy transfer pathway was constructed by columnar anthracene stacks formed from the DNA-templated self-assembly of TACT. Copyright © 2013 Elsevier B.V. All rights reserved.

Biochemical response of anthracene and benzo [a] pyrene in milkfish Chanos chanos.

PubMed

Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M; Anand, M

2012-01-01

Polycyclic aromatic hydrocarbons (PAHs) are common toxic pollutants found in the aquatic environment, and the assessment of their impact on biota is of considerable concern. The aim of the present research was to study the acute toxicity, bioaccumulation and biochemical response of milkfish Chanos chanos (Forsskal) to two selected PAHs: anthracene and benzo [a] pyrene. Acute toxicity test results were evaluated by the Probit analysis method and 96h LC(50) values for C. chanos exposed to anthracene was 0.030mgl(-1) and 0.014mgl(-1) for benzo [a] pyrene. Bioaccumulation concentration of anthracene was high when compared to benzo [a] pyrene. Biomarkers indicative of neurotoxicity (acetylcholinesterase, AchE), oxidative stress (lipid peroxidation, LPO and catalase, CAT) and phase II biotransformation of xenobiotics (glutathione S transferase, GST and reduced glutathione, GSH) were measured to assess effects of selected PAHs. Anthracene and benzo [a] pyrene increase LPO and CAT level of C. chanos suggesting that these PAHs may induce oxidative stress. Both the PAHs inhibited AchE indicating that they have at least one mechanism of neurotoxicity in common: the disruption of cholinergic transmission by inhibition of AChE. An induction of C. chanos glutathione S-transferase (GST) activity was found in fish exposed to benzo [a] pyrene, while an inhibition was observed after exposure to anthracene. These results suggest that GST is involved in the detoxification of benzo [a] pyrene, but not of anthracene. Copyright © 2011 Elsevier Inc. All rights reserved.

40 CFR 704.43 - Chlorinated naphthalenes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chlorinated naphthalenes. 704.43... § 704.43 Chlorinated naphthalenes. (a) Definitions. (1) Extent of chlorination means the percent by... means the relative amounts of each isomeric chlorinated naphthalene that composes the chemical substance...

40 CFR 704.43 - Chlorinated naphthalenes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Chlorinated naphthalenes. 704.43... § 704.43 Chlorinated naphthalenes. (a) Definitions. (1) Extent of chlorination means the percent by... means the relative amounts of each isomeric chlorinated naphthalene that composes the chemical substance...

Removal of phenanthrene from soil by co-cultures of bacteria and fungi pregrown on sugarcane bagasse pith.

PubMed

Chávez-Gómez, B; Quintero, R; Esparza-García, F; Mesta-Howard, A M; Zavala Díaz de la Serna, F J; Hernández-Rodríguez, C H; Gillén, T; Poggi-Varaldo, H M; Barrera-Cortés, J; Rodríguez-Vázquez, R

2003-09-01

Sixteen co-cultures composed of four bacteria and four fungi grown on sugarcane bagasse pith were tested for phenanthrene degradation in soil. The four bacteria were identified as Pseudomonas aeruginose, Ralstonia pickettii, Pseudomonas sp. and Pseudomonas cepacea. The four fungi were identified as: Penicillium sp., Trichoderma viride, Alternaria tenuis and Aspergillus terrus that were previously isolated from different hydrocarbon-contaminated soils. Fungi had a statistically significant positive (0.0001

Microbial Degradation of Phenanthrene in Pristine and Contaminated Sandy Soils.

PubMed

Schwarz, Alexandra; Adetutu, Eric M; Juhasz, Albert L; Aburto-Medina, Arturo; Ball, Andrew S; Shahsavari, Esmaeil

2018-05-01

Phenanthrene mineralisation studies in both pristine and contaminated sandy soils were undertaken through detailed assessment of the activity and diversity of the microbial community. Stable isotope probing (SIP) was used to assess and identify active 13 C-labelled phenanthrene degraders. Baseline profiling indicated that there was little difference in fungal diversity but a significant difference in bacterial diversity dependent on contamination history. Identification of dominant fungal and bacterial species highlighted the presence of organisms capable of degrading various petroleum-based compounds together with other anthropogenic compounds, regardless of contamination history. Community response following a simulated contamination event ( 14 C-phenanthrene) showed that the microbial community in deep pristine and shallow contaminated soils adapted most to the presence of phenanthrene. The similarity in microbial community structure of well-adapted soils demonstrated that a highly adaptable fungal community in these soils enabled a rapid response to the introduction of a contaminant. Ten fungal and 15 bacterial species were identified as active degraders of phenanthrene. The fungal degraders were dominated by the phylum Basidiomycota including the genus Crypotococcus, Cladosporium and Tremellales. Bacterial degraders included the genera Alcanivorax, Marinobacter and Enterococcus. There was little synergy between dominant baseline microbes, predicted degraders and those that were determined to be actually degrading the contaminant. Overall, assessment of baseline microbial community in contaminated soils provides useful information; however, additional laboratory assessment of the microbial community's ability to degrade pollutants allows for better prediction of the bioremediation potential of a soil.

Potential of Endophytic Bacterium Paenibacillus sp. PHE-3 Isolated from Plantago asiatica L. for Reduction of PAH Contamination in Plant Tissues

PubMed Central

Zhu, Xuezhu; Jin, Li; Sun, Kai; Li, Shuang; Ling, Wanting; Li, Xuelin

2016-01-01

Endophytes are ubiquitous in plants, and they may have a natural capacity to biodegrade polycyclic aromatic hydrocarbons (PAHs). In our study, a phenanthrene-degrading endophytic Paenibacillus sp. PHE-3 was isolated from P. asiatica L. grown in a PAH-contaminated site. The effects of environmental variables on phenanthrene biodegradation by strain PHE-3 were studied, and the ability of strain PHE-3 to use high molecular weight PAH (HMW-PAH) as a sole carbon source was also evaluated. Our results indicated that pH value of 4.0–8.0, temperature of 30 °C–42 °C, initial phenanthrene concentration less than 100 mg·L−1, and some additional nutrients are favorable for the biodegradation of phenanthrene by strain PHE-3. The maximum biodegradation efficiency of phenanthrene was achieved at 99.9% after 84 h cultivation with additional glutamate. Moreover, the phenanthrene biodegradation by strain PHE-3 was positively correlated with the catechol 2,3-dioxygenase activity (ρ = 0.981, p < 0.05), suggesting that strain PHE-3 had the capability of degrading HMW-PAHs. In the presence of other 2-, 3-ringed PAHs, strain PHE-3 effectively degraded HMW-PAHs through co-metabolism. The results of this study are beneficial in that the re-colonization potential and PAH degradation performance of endophytic Paenibacillus sp. PHE-3 may be applied towards reducing PAH contamination in plants. PMID:27347988

Changes in the Bacterial Community Structure of Remediated Anthracene-Contaminated Soils

PubMed Central

Delgado-Balbuena, Laura; Bello-López, Juan M.; Navarro-Noya, Yendi E.; Rodríguez-Valentín, Analine; Luna-Guido, Marco L.; Dendooven, Luc

2016-01-01

Mixing soil or adding earthworms (Eisenia fetida (Savigny, 1826)) accelerated the removal of anthracene, a polycyclic aromatic hydrocarbon, from a pasture and an arable soil, while a non-ionic surfactant (Surfynol® 485) inhibited the removal of the contaminant compared to the untreated soil. It was unclear if the treatments affected the soil bacterial community and consequently the removal of anthracene. Therefore, the bacterial community structure was monitored by means of 454 pyrosequencing of the 16S rRNA gene in the pasture and arable soil mixed weekly, amended with Surfynol® 485, E. fetida or organic material that served as food for the earthworms for 56 days. In both soils, the removal of anthracene was in the order: mixing soil weekly (100%) > earthworms applied (92%) > organic material applied (77%) > untreated soil (57%) > surfactant applied (34%) after 56 days. There was no clear link between removal of anthracene from soil and changes in the bacterial community structure. On the one hand, application of earthworms removed most of the contaminant from the arable soil and had a strong effect on the bacterial community structure, i.e. a decrease in the relative abundance of the Acidobacteria, Chloroflexi and Gemmatimonadetes, and an increase in that of the Proteobacteria compared to the unamended soil. Mixing the soil weekly removed all anthracene from the arable soil, but had little or no effect on the bacterial community structure. On the other hand, application of the surfactant inhibited the removal of anthracene from the arable soil compared to the untreated soil, but had a strong effect on the bacterial community structure, i.e. a decrease in the relative abundance of Cytophagia (Bacteroidetes), Chloroflexi, Gemmatimonadetes and Planctomycetes and an increase in that of the Flavobacteria (Bacteroidetes) and Proteobacteria. Additionally, the removal of anthracene was similar in the different treatments of both the arable and pasture soil, but the effect of application of carrot residue, earthworms or the surfactant on the bacterial community structure was more accentuated in the arable soil than in the pasture soil. It was found that removal of anthracene was not linked to changes in the bacterial community structure. PMID:27727277

Does a concomitant exposure to lead influence unfavorably the naphthalene subchronic toxicity and toxicokinetics?

PubMed

Katsnelson, Boris A; Minigaliyeva, Ilzira A; Degtyareva, Tamara D; Privalova, Larisa I; Beresneva, Tatyana A

2014-01-01

Rats were given 20 times during 40 d either naphthalene per gavage or the same and lead acetate intraperitoneally in single doses corresponding to 5% of the respective 50% lethal doses. The concomitant exposure to lead not only added some typical indicators of lead toxicity to the moderate naphthalene intoxication picture but also exaggerated some less specific indices for intoxication. However, a number of such indices testified to attenuation of naphthalene's adverse effects under the impact of lead. Lead also lowered urinary excretion of both total and conjugated naphthalene, while the free- to total naphthalene ratio in urine sharply increased. These results corroborate implicitly the initial hypothesis that lead, being an inhibitor of cytochrome P450, hinders phase I of the naphthalene biotransformation and, thus, the formation of derivates which can be more toxic but are capable of entering into reactions of conjugation with resulting detoxication and elimination of naphthalene from the body. © 2013 SETAC.

Changes in oxygen consumption and respiratory enzymes as stress indicators in an estuarine edible crab Scylla serrata exposed to naphthalene.

PubMed

Vijayavel, K; Balasubramanian, M P

2006-06-01

The sublethal effect of naphthalene was studied on the physiology of a mud crab Scylla serrata. The 96 h acute toxicity of naphthalene was determined and found to be 28 mg 1(-1) (LC100), 18 mg 1(-1) (LC50), 10 mg 1(-1) (LC0) respectively. The 30 days sublethal effect (LC0) 9 mg 1(-1), 8 mg 1(-1), 10 mg 1(-1), of naphthalene was investigated in the crab S. serrata with reference to oxygen consumption and changes in the activity of respiratory enzymes. The results indicated that naphthalene caused disturbance in the normal physiology of the crab. The bioaccumulation of naphthalene was also investigated in gills, hepatopancreas, haemolymph and ovary. The consumption of oxygen increased in the naphthalene medium when compared with that of the crabs exposed to naphthalene free medium. A decreased trend in the activity of respiratory enzymes such as lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), alpha-ketoglutarate dehydrogenase (alpha-KDH) and glutathione (GSH) were recorded in the hepatopancreas, ovary and gills of S. serrata for all the tested concentrations of naphthalene and the results were analyzed for their significance.

16S metagenomic analysis reveals adaptability of a mixed-PAH-degrading consortium isolated from crude oil-contaminated seawater to changing environmental conditions.

PubMed

Muangchinda, Chanokporn; Rungsihiranrut, Adisan; Prombutara, Pinidphon; Soonglerdsongpha, Suwat; Pinyakong, Onruthai

2018-05-29

A bacterial consortium, named SWO, was enriched from crude oil-contaminated seawater from Phrao Bay in Rayong Province, Thailand, after a large oil spill in 2013. The bacterial consortium degraded a polycyclic aromatic hydrocarbon (PAH) mixture consisting of phenanthrene, anthracene, fluoranthene, and pyrene (50 mg L -1 each) by approximately 73%, 69%, 52%, and 48%, respectively, within 21 days. This consortium exhibited excellent adaptation to a wide range of environmental conditions. It could degrade a mixture of four PAHs under a range of pH values (4.0-9.0), temperatures (25 °C-37 °C), and salinities (0-10 g L -1 with NaCl). In addition, this consortium degraded 20-30% of benzo[a]pyrene and perylene (10 mg L -1 each), high molecular weight PAHs, in the presence of other PAHs within 35 days, and degraded 40% of 2% (v/v) crude oil within 20 days. The 16S rRNA gene amplicon sequencing analysis demonstrated that Pseudomonas and Methylophaga were the dominant genera of consortium SWO in almost all treatments, while Pseudidiomarina, Thalassospira and Alcanivorax were predominant under higher salt concentrations. Moreover, Pseudomonas and Alcanivorax were dominant in the crude oil-degradation treatment. Our results suggest that the consortium SWO maintained its biodegradation ability by altering the bacterial community profile upon encountering changes in the environmental conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Areal distribution and concentrations of contaminants of concern in surficial streambed and lakebed sediments, Lake Erie-Lake Saint Clair Drainages, 1990-97

USGS Publications Warehouse

Rheaume, S.J.; Button, D.T.; Myers, Donna N.; Hubbell, D.L.

2001-01-01

Concerns about elevated concentrations of contaminants such as polychlorinated biphenyls and mercury in aquatic bed sediments throughout the Great Lakes Basin have resulted in a need for better understanding of the scope and severity of the problem. Various organochlorine pesticides, polychlorinated biphenyls, trace metals, and polycyclic aromatic hydrocarbons are a concern because of their ability to persist and accumulate in aquatic sediments and their association with adverse aquatic biological effects. The areal distribution and concentrations in surficial bed sediments of 20 contaminants of concern with established bed-sediment-toxicity guidelines were examined in relation to their potential effects on freshwater aquatic biota. Contaminants at more than 800 sampling locations are characterized in this report. Surficial bed-sediment-quality data collected from 1990 to 1997 in the Lake Erie?Lake Saint Clair Drainages were evaluated to reflect recent conditions. In descending order, concentrations of total polycyclic aromatic hydrocarbons, phenanthrene, total polychlorinated biphenyls, chrysene, benz[a]anthracene, benzo[a]pyrene, cadmium, lead, zinc, arsenic, and mercury were the contaminants that most commonly exceeded levels associated with probable adverse effects on aquatic benthic organisms. The highest concentrations of most of these contaminants in aquatic bed sediments are confined to the 12 specific geographic Areas of Concern identified in the 1987 Revisions to the Great Lakes Water Quality Agreement of 1972. An exception is arsenic, which was detected at concentrations exceeding threshold effect levels at many locations outside Areas of Concern.

A detailed kinetic modeling study of toluene oxidation in a premixed laminar flame

PubMed Central

Tian, Zhenyu; Pitz, William J.; Fournet, René; Glaude, Pierre-Alexander; Battin-Leclerc, Frédérique

2013-01-01

An improved chemical kinetic model for the toluene oxidation based on experimental data obtained in a premixed laminar low-pressure flame with vacuum ultraviolet (VUV) photoionization and molecular beam mass spectrometry (MBMS) techniques has been proposed. The present mechanism consists of 273 species up to chrysene and 1740 reactions. The rate constants of reactions of toluene decomposition, reaction with oxygen, ipso-additions and metatheses with abstraction of phenylic H-atom are updated; new pathways of C4 + C2 species giving benzene and fulvene are added. Based on the experimental observations, combustion intermediates such as fulvenallene, naphtol, methylnaphthalene, acenaphthylene, 2-ethynylnaphthalene, phenanthrene, anthracene, 1-methylphenanthrene, pyrene and chrysene are involved in the present mechanism. The final toluene model leads to an overall satisfactory agreement between the experimentally observed and predicted mole fraction profiles for the major products and most combustion intermediates. The toluene depletion is governed by metathese giving benzyl radicals, ipso-addition forming benzene and metatheses leading to C6H4CH3 radicals. A sensitivity analysis indicates that the unimolecular decomposition via the cleavage of a methyl C-H bond has a strong inhibiting effect, while decomposition via C-C bond breaking, ipso-addition of H-atom to toluene, decomposition of benzyl radicals and reactions related to C6H4CH3 radicals have promoting effect for the consumption of toluene. Moreover, flow rate analysis is performed to illustrate the formation pathways of mono- and polycyclic aromatics. PMID:23762016

Phytoremediation of Polycyclic Aromatic Hydrocarbons in Soils Artificially Polluted Using Plant-Associated-Endophytic Bacteria and Dactylis glomerata as the Bioremediation Plant.

PubMed

Gałązka, Ann; Gałązka, Rafał

2015-01-01

The reaction of soil microorganisms to the contamination of soil artificially polluted with polycyclic aromatic hydrocarbons (PAHs) was evaluated in pot experiments. The plant used in the tests was cock's foot (Dactylis glomerata). Three different soils artificially contaminated with PAHs were applied in the studies. Three selected PAHs (anthracene, phenanthrene, and pyrene) were used at the doses of 100, 500, and 1000 mg/kg d.m. of soil and diesel fuel at the doses of 100, 500, and 1000 mg/kg d.m. of soil. For evaluation of the synergistic effect of nitrogen fixing bacteria, the following strains were selected: associative Azospirillum spp. and Pseudomonas stutzerii. Additionally, in the bioremediation process, the inoculation of plants with a mixture of the bacterial strains in the amount of 1 ml suspension per 500 g of soil was used. Chamber pot-tests were carried out in controlled conditions during four weeks of plant growth period. The basic physical, microbiological and biochemical properties in contaminated soils were determined. The obtained results showed a statistically important increase in the physical properties of soils polluted with PAHs and diesel fuel compared with the control and also an important decrease in the content of PAHs and heavy metals in soils inoculated with Azospirillum spp. and P. stutzeri after cock's foot grass growth. The bioremediation processes were especially intensive in calcareous rendzina soil artificially polluted with PAHs.

Polycyclic aromatic hydrocarbons (PAHs) in soils and vegetation near an e-waste recycling site in South China: concentration, distribution, source, and risk assessment.

PubMed

Wang, Yan; Tian, Zhongjing; Zhu, Haolin; Cheng, Zhineng; Kang, Meiling; Luo, Chunling; Li, Jun; Zhang, Gan

2012-11-15

This study determined the concentrations of PAHs generated from e-waste recycling activities and their potential impacts on soil, vegetation, and human health. The total PAH concentrations in soils and plants ranged from 127 to 10,600 and 199 to 2420 ng/g, respectively. Samples from an e-waste burning site had higher PAH concentrations than samples from adjacent locations. The PAHs in plants varied with plant species and tissue, and Lactuca sativa L. contained the highest PAHs of all the vegetable species. Various land use types showed different PAH concentrations in soils, with vegetable fields showing higher concentrations than paddy fields. Low molecular weight PAHs, such as phenanthrene, were the predominant congeners in soils, whereas high molecular weight PAHs, such as fluoranthene, pyrene, and benzo[a]anthracene, were enriched in plants relative to soils. Dissimilar PAH profiles in soil and the corresponding vegetation indicated that the uptake of PAHs by plants was selective. A source analysis showed that the contamination by PAHs originated primarily from the open burning of e-waste. The total daily intakes of PAHs and carcinogenic PAHs through vegetables at the e-waste dismantling site were estimated to be 279 and 108 ng/kg/d, respectively, indicating that the consumption of vegetables grown near e-waste recycling sites is risky and should be completely avoided. Copyright © 2012 Elsevier B.V. All rights reserved.

Two-liquid-phase system: A promising technique for predicting bioavailability of polycyclic aromatic hydrocarbons in long-term contaminated soils.

PubMed

Wang, Congying; Wang, Ziyu; Li, Zengbo; Ahmad, Riaz

2017-02-01

A two-liquid-phase system (TLPS), which consisted of soil slurry and silicone oil, was employed to extract polycyclic aromatic hydrocarbons (PAHs) in four long-term contaminated soils in order to assess the bioavailability of PAHs. Extraction kinetics of six PAHs viz. phenanthrene, fluoranthene, pyrene, benzo(a)anthracene, benzo(a)pyrene, dibenzo(a,h)anthrancene were selected to investigate as they covered the susceptible and recalcitrant PAHs in soil. A parallel experiments were also carried out on the microbial degradation of these PAHs in soil with and without biostimulation (by adding (NH 4 ) 2 HPO 4 ). The rapidly desorbed fraction of fluoranthene, as indicated by the two-fraction model, was found the highest, ranging from 21.4% to 37.4%, whereas dibenzo(a,h)anthrancene was the lowest, ranging from 8.9% to 20.5%. The rapid desorption of selected PAHs was found to be finished within 24 h. The rapidly desorbed fraction of PAHs investigated using TLPS, was significantly correlated (R 2  = 0.95) with that degraded by microorganisms in biostimulation treatment. This suggested that the TLPS-assisted extraction could be a promising technique in determining the bioavailability of aged PAHs in contaminated soils. It also suggested that applying sufficient nutrients in bioremediation of field contaminated soils is crucial. Further work is required to test its application to more hydrophobic organic pollutants in long-term contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cyclodextrin-functionalized mesostructured silica nanoparticles for removal of polycyclic aromatic hydrocarbons.

PubMed

Topuz, Fuat; Uyar, Tamer

2017-07-01

Polycyclic aromatic hydrocarbons (PAHs) are the byproducts of the incomplete combustion of carbon-based fuels, and have high affinity towards DNA strands, ultimately exerting their carcinogenic effects. They are ubiquitousenvironmental contaminants,and can accumulate on tissues due to their lipophilic nature. In this article, we describe a novel concept for PAH removal from aqueous solutions using cyclodextrin-functionalized mesostructured silica nanoparticles (CDMSNs) and pristine mesostructured silica nanoparticles (MSNs). The adsorption applications of MSNs are greatly restricted due to the absence of surface functional groups on such particles. In this regard, cyclodextrins can serve as ideal functional molecules with their toroidal, cone-type structure, capable of inclusion-complex formation with many hydrophobic molecules, including genotoxic PAHs. The CDMSNs were synthesized by the surfactant-templated, NaOH-catalyzed condensation reactions of tetraethyl orthosilicate (TEOS) in the presence of two different types of cyclodextrin (i.e. hydroxypropyl-β-cyclodextrin (HP-β-CD) and native β-cyclodextrin (β-CD)). The physical incorporation of CD moieties was supported by XPS, FT-IR, NMR, TGA and solid-state 13 C NMR. The CDMSNs were treated with aqueous solutions of five different PAHs (e.g. pyrene, anthracene, phenanthrene, fluorene and fluoranthene). The functionalization of MSNs with cyclodextrin moieties significantly boosted the sorption capacity (q) of the MSNs up to ∼2-fold, and the q ranged between 0.3 and 1.65mg per gram CDMSNs, of which the performance was comparable to that of the activated carbon. Copyright © 2017 Elsevier Inc. All rights reserved.

Biotechnological procedures to select white rot fungi for the degradation of PAHs.

PubMed

Lee, Hwanhwi; Jang, Yeongseon; Choi, Yong-Seok; Kim, Min-Ji; Lee, Jaejung; Lee, Hanbyul; Hong, Joo-Hyun; Lee, Young Min; Kim, Gyu-Hyeok; Kim, Jae-Jin

2014-02-01

White rot fungi are essential in forest ecology and are deeply involved in wood decomposition and the biodegradation of various xenobiotics. The fungal ligninolytic enzymes involved in these processes have recently become the focus of much attention for their possible biotechnological applications. Successful bioremediation requires the selection of species with desirable characteristics. In this study, 150 taxonomically and physiologically diverse white rot fungi, including 55 species, were investigated for their performance in a variety of biotechnological procedures, such as dye decolorization, gallic acid reaction, ligninolytic enzymes, and tolerance to four PAHs, phenanthrene, anthracene, fluoranthene, and pyrene. Among these fungi, six isolates showed the highest (>90%) tolerance to both individual PAH and mixed PAHs. And six isolates oxidized gallic acid with dark brown color and they rapidly decolorized RBBR within ten days. These fungi revealed various profiles when evaluated for their biotechnological performance to compare the capability of degradation of PAHs between two groups selected. As the results demonstrated the six best species selected from gallic acid more greatly degraded four PAHs than the other isolates selected via tolerance test. It provided that gallic acid reaction test can be performed to rank the fungi by their ability to degrade the PAHs. Most of all, Peniophora incarnata KUC8836 and Phlebia brevispora KUC9033 significantly degraded the four PAHs and can be considered prime candidates for the degradation of xenobiotic compounds in environmental settings. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of PAHs uptake by selected Monocotyledones and Dicotyledones from municipal and industrial sewage sludge.

PubMed

Gworek, Barbara; Klimczak, Katarzyna; Kijeńska, Marta; Gozdowski, Dariusz

2016-10-01

The study was focused on two goals: (i) the confirmation of the existence of a general relation between the content of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and in plants growing in it, regardless of the type and content of sewage sludge, and (ii) if so, the answer to the question whether the uptake of PAHs by plants depends on their type. To realize the set aims, the contents of PAHs in four differentiated plant species were measured, two belonging to the Monocotyledones and two belonging to Dicotyledones group, growing in municipal and industrial sewage sludge in two locations. All the investigations were carried out during the period of 3 years. The results clearly demonstrated that the uptake of PAHs by a plant depended on polyaromatic hydrocarbon concentration in the sewage sludge. The relation between accumulation coefficient of PAHs in plant material vs. the content of PAH in sewage sludge was of exponential character. The results indicate that in case of four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, regardless of the type and origin of sewage sludge and the type of plant. For three-ring PAHs, we can assume for Monocotyledones that the root uptake mechanism occurs because we observe a significant correlation between the content of fluorene, phenanthrene, and anthracene in plant material and in the sewage sludge. For Dicotyledones, the correlation is insignificant, and in this case probably two mechanisms occur-the uptake by roots and by leaves.

Polycyclic aromatic hydrocarbons in the leaves of twelve plant species along an urbanization gradient in Shanghai, China.

PubMed

Liang, Jing; Fang, Hailan; Zhang, Taolin; Wang, Xingxiang

2017-04-01

Plants, particularly their leaves, play an important role in filtering both gas-phase and particle-phase polycyclic aromatic hydrocarbons (PAHs). However, many studies have focused on the accumulation and adsorption functions of plant leaves, possibly underestimating the effects that plants have on air quality. Therefore, eight tree species from different locations in Shanghai were selected to assess PAH filtering (via adsorption and capture) using washed and unwashed plant leaves. The differences in the total PAH contents in the washed leaves were constant for the different species across the different sampling sites. The PAH levels decreased in the following order: industrial areas > traffic areas > urban areas > background area. The PAH compositions in the different plant leaves were dominated by fluorene (Fle), phenanthrene (Phe), anthracene (Ant), chrysene (Chr), fluoranthene (Flu), and pyrene (Pyr); notably, Phe accounted for 49.4-76.7% of the total PAHs. By comparing the PAH contents in the washed leaves with the PAH contents in the unwashed leaves, Pittosporum tobira (P. tobira), Ginkgo biloba (G. biloba), and Platanus acerifolia (P. acerifolia) were found to be efficient species for adsorbing PAHs, while Osmanthus fragrans (O. fragrans), Magnolia grandiflora (M. grandiflora), and Prunus cerasifera Ehrh. (P. cerasifera Ehrh.) were efficient species for capturing PAHs. The efficiencies of the plant leaves for the removal of PAHs from air occurred in the order of low molecular weight > medium molecular weight > high molecular weight PAHs.

Reinforced microextraction of polycyclic aromatic hydrocarbons from polluted soil samples using an in-needle coated fiber with polypyrrole/graphene oxide nanocomposite.

PubMed

Behfar, Mina; Ghiasvand, Ali Reza; Yazdankhah, Fatemeh

2017-07-01

The surface of a stainless-steel wire was platinized using electrophoretic deposition method to create a high-surface-area with porous and cohesive substrate. The platinized fiber was coated by the polypyrrole/graphene oxide nanocomposite by electropolymerization and accommodated into a stainless-steel needle to fabricate an in-needle coated fiber. The developed setup was coupled to gas chromatography with flame ionization detection and applied to extract and determine polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene, and pyrene) in complicated solid matrices, along with reinforcement of the extraction by cooling the sorbent, using liquid carbon dioxide. To obtain the best extraction efficiency, the important experimental variables including extraction temperature and time, temperature of cooled sorbent, sampling flow rate, and desorption condition were studied. Under the optimal condition, limits of detection for five studied analytes were in the range of 0.2-0.8 pg/g. Linear dynamic ranges for the calibration curves were found to be in the range of 0.001-1000 ng/g. Relative standard deviations obtained for six replicated analyses of 1 ng/g of analytes were 4.9-13.5%. The reinforced in-needle coated fiber method was successfully applied for the analysis of polycyclic aromatic hydrocarbons in contaminated soil samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Levels and sources of PAHs in selected sites from Portugal: biomonitoring with Pinus pinea and Pinus pinaster needles.

PubMed

Ratola, Nuno; Amigo, José Manuel; Alves, Arminda

2010-04-01

Pine needle samples from two pine species (Pinus pinaster Ait. and Pinus pinea L.) were collected at 29 sites scattered throughout Portugal, in order to biomonitor the levels and trends of 16 polycyclic aromatic hydrocarbons (PAHs). The values obtained for the sum of all PAHs ranged from 76 to 1944 ng/g [dry weight (dw)]. Despite the apparent matrix similarities between both pine species, P. pinaster needles revealed higher mean entrapment levels than P. pinea (748 and 399 ng/g (dw) per site, respectively). The urban and industrial sites have the highest average of PAH incidence [for P. pinea, 465 and 433 ng/g (dw) per site, respectively, and for P. pinaster, 1147 and 915 ng/g (dw)], followed by the rural sites [233 ng/g and 711 ng/g (dw) per site, for P. pinea and P. pinaster, respectively]. The remote sites, both from P. pinaster needles, show the least contamination, with 77 ng/g (dw) per site. A predominance of 3-ring and 4-ring PAHs was observed in most samples, with phenanthrene having 30.1% of the total. Naphthalene prevailed in remote sites. Rainfall had no influence on the PAHs levels, but there was a relationship between higher wind speeds and lower concentrations. PAH molecular ratios revealed the influence of both petrogenic and pyrogenic sources.

Sequence-based screening for self-sufficient P450 monooxygenase from a metagenome library.

PubMed

Kim, B S; Kim, S Y; Park, J; Park, W; Hwang, K Y; Yoon, Y J; Oh, W K; Kim, B Y; Ahn, J S

2007-05-01

Cytochrome P450 monooxygenases (CYPs) are useful catalysts for oxidation reactions. Self-sufficient CYPs harbour a reductive domain covalently connected to a P450 domain and are known for their robust catalytic activity with great potential as biocatalysts. In an effort to expand genetic sources of self-sufficient CYPs, we devised a sequence-based screening system to identify them in a soil metagenome. We constructed a soil metagenome library and performed sequence-based screening for self-sufficient CYP genes. A new CYP gene, syk181, was identified from the metagenome library. Phylogenetic analysis revealed that SYK181 formed a distinct phylogenic line with 46% amino-acid-sequence identity to CYP102A1 which has been extensively studied as a fatty acid hydroxylase. The heterologously expressed SYK181 showed significant hydroxylase activity towards naphthalene and phenanthrene as well as towards fatty acids. Sequence-based screening of metagenome libraries is expected to be a useful approach for searching self-sufficient CYP genes. The translated product of syk181 shows self-sufficient hydroxylase activity towards fatty acids and aromatic compounds. SYK181 is the first self-sufficient CYP obtained directly from a metagenome library. The genetic and biochemical information on SYK181 are expected to be helpful for engineering self-sufficient CYPs with broader catalytic activities towards various substrates, which would be useful for bioconversion of natural products and biodegradation of organic chemicals.

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. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Evidence for a pore-filling mechanism in the adsorption of aromatic hydrocarbons to a natural wood char.

PubMed

Nguyen, Thanh H; Cho, Hyun-Hee; Poster, Dianne L; Ball, William P

2007-02-15

Sorption isotherms for five aromatic hydrocarbons were obtained with a natural wood char (NC1) and its residue after solvent extraction (ENC1). Substantial isotherm nonlinearity was observed in all cases. ENC1 showed higher BET surface area, higher nitrogen-accessible micropore volume, and lower mass of extractable organic chemicals, including quantifiable polycyclic aromatic hydrocarbons (PAHs),while the two chars showed identical surface oxygen/ carbon (O/C) ratio. For two chlorinated benzenes that normally condense as liquids at the temperatures used, sorption isotherms with NC1 and ENC1 were found to be statistically identical. For the solid-phase compounds (1,4-dichlorobenzene (1,4-DCB) and two PAHs), sorption was statistically higher with ENC1, thus demonstrating sorption effects due to both (1) authigenic organic content in the sorbentand (2)the sorbate's condensed state. Polanyi-based isotherm modeling, pore size measurements, and comparisons with activated carbon showthe relative importance of adsorptive pore filling and help explain results. With both chars, maximum sorption increased in the order of decreasing molecular diameter: phenanthrene < naphthalene < 1,2-dichlorobenzene/1,2,4-trichlorobenzene < 1,4-DCB. Comparison of 1,4- and 1,2-DCB shows that the critical molecular diameter was apparently more important than the condensed state, suggesting that 1,4-DCB sorbed in the liquid state for ENC1.

Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units.

PubMed

Schmidt, Stine N; Holmstrup, Martin; Smith, Kilian E C; Mayer, Philipp

2013-07-02

A 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects were linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑C(lipid eq.)), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LC(lipid eq 50)) of 133 mmol kg(-1) lipid in good correspondence with the lethal membrane burden for baseline toxicity (40-160 mmol kg(-1) lipid). Finally, the effective lethal toxic unit (LTU50) of 1.20 was rather close to the expected value of 1. Altogether, passive dosing provided tightly controlled mixture exposure in terms of both level and composition, while ∑a, ∑C(lipid eq.), and ∑TU allowed baseline toxicity to be linked to mixture exposure.

H/C atomic ratio as a smart linkage between pyrolytic temperatures, aromatic clusters and sorption properties of biochars derived from diverse precursory materials

PubMed Central

Xiao, Xin; Chen, Zaiming; Chen, Baoliang

2016-01-01

Biochar is increasingly gaining attention due to multifunctional roles in soil amelioration, pollution mitigation and carbon sequestration. It is a significant challenge to compare the reported results from world-wide labs regarding the structure and sorption of biochars derived from various precursors under different pyrolytic conditions due to a lack of a simple linkage. By combining the published works on various biochars, we established a quantitative relationship between H/C atomic ratio and pyrolytic temperature (T), aromatic structure, and sorption properties for naphthalene and phenanthrene. A reverse sigmoid shape between T and the H/C ratio was observed, which was independent of the precursors of biochars, including the ash contents. Linear correlations of Freundlich parameters (N, log Kf) and sorption amount (log Qe, log QA) with H/C ratios were found. A rectangle-like model was proposed to predict the aromatic cluster sizes of biochars from their H/C ratios, and then a good structure-sorption relationship was derived. These quantitative relationships indicate that the H/C atomic ratio is a universal linkage to predict pyrolytic temperatures, aromatic cluster sizes, and sorption characteristics. This study would guide the global study of biochars toward being comparable, and then the development of the structure-sorption relationships will benefit the structural design and environmental application of biochars. PMID:26940984

Pseudomonas diversity in crude-oil-contaminated intertidal sand samples obtained after the Prestige oil spill.

PubMed

Mulet, Magdalena; David, Zoyla; Nogales, Balbina; Bosch, Rafael; Lalucat, Jorge; García-Valdés, Elena

2011-02-01

The Galicia seashore, in northwestern Spain, was one of the shorelines affected by the Prestige oil spill in November 2002. The diversity of autochthonous Pseudomonas populations present at two beaches (Carnota municipality) was analyzed using culture-independent and culture-dependent methods. The first analysis involved the screening of an rpoD gene library. The second involved the isolation of 94 Pseudomonas strains that were able to grow on selective media by direct plating or after serial enrichments on several carbon sources: biphenyl, gentisate, hexadecane, methylnaphthalene, naphthalene, phenanthrene, salicylate, xylene, and succinate. Eight denitrifying Pseudomonas strains were also isolated by their ability to grow anaerobically with nitrate. The calculated coverage index for Pseudomonas species was 89% when clones and isolates were considered together, and there were 29 phylospecies detected. The most abundant were members of the species P. stutzeri, P. putida, P. anguilliseptica, and P. oleovorans. Thirty-one isolates could not be identified at the species level and were considered representatives of 16 putative novel Pseudomonas species. One isolate was considered representative of a novel P. stutzeri genomovar. Concordant results were obtained when the diversities of the cloned DNA library and the cultured strains were compared. The clone library obtained by the rpoD PCR method was a useful tool for evaluating Pseudomonas communities and also for microdiversity studies of Pseudomonas populations.

Ultra preconcentration of polycyclic aromatic hydrocarbons in smoked bacon by a combination of SPE and DLLME.

PubMed

Liu, Xiaofang; Zhou, Shu; Zhu, Quanfei; Ye, Yong; Chen, Huaixia

2014-09-01

A sample pretreatment method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was established for the sensitive determination of polycyclic aromatic hydrocarbons (PAHs) in smoked bacon samples. In the SPE-DLLME process, three PAHs including naphthalene (Naph), phenanthrene (Phen) and pyrene (Pyr) were extracted from samples and transferred into C18 SPE cartridge. The target analytes were subsequently eluted with 1.2 ml of acetonitrile-dichloromethane (5:1, v/v) mixture solution. The eluent was injected directly into the 5.0 ml ultrapure water in the subsequent DLLME procedure. The sedimented phase was concentrated under a gentle nitrogen flow to 120.0 µl. Finally, the analytes in the extraction solvent were determined by high-performance liquid chromatography with a ultra-violet detector. Some important extraction parameters affecting the performance, such as the sample solution flow rate, breakthrough volume, salt addition as well as the type and volume of the elution solvent were optimized. The developed method provided an ultra enrichment factors for PAHs ranged from 3478 to 3824. The method was applied for the selective extraction and sensitive determination of PAHs in smoked bacon samples. The limits of detection (S/N = 3) were 0.05, 0.01, 0.02 μg kg(-1) for Naph, Phen, Pyr, respectively. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Toxic effects of combined effects of anthracene and UV radiation on Brachionus plicatilis

NASA Astrophysics Data System (ADS)

Gao, Ceng; Zhang, Xinxin; Xu, Ningning; Tang, Xuexi

2017-05-01

Anthracene is a typical polycyclic aromatic hydrocarbon, with photo activity, can absorb ultraviolet light a series of chemical reactions, aquatic organisms in the ecosystem has a potential light induced toxicity. In this paper, the effects of anthracene and UV radiation on the light-induced toxicity of Brachionus plicatilis were studied. The main methods and experimental results were as follows: (1) The semi-lethal concentration of anthracene in UV light was much lower than that in normal light, The rotifers have significant light-induced acute toxicity. (2) Under UV irradiation, anthracene could induce the increase of ROS and MDA content in B. plicatilis, and the activity of antioxidant enzymes in B. plicatilis significantly changed, Where SOD, GPx activity was induced within 24 hours of the beginning of the experiment. And the content of GPX and CAT was inhibited after 48 hours. Therefore, the anthracite stress induced by UV radiation could more strongly interfere with the ant oxidative metabolism of B. plicatilis, and more seriously cause oxidative damage, significant light-induced toxicity.

21 CFR 172.824 - Sodium mono- and dimethyl naphthalene sulfonates.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium mono- and dimethyl naphthalene sulfonates... sulfonates. The food additive sodium mono- and dimethyl naphthalene sulfonates may be safely used in... statement declaring the presence of sodium mono- and dimethyl naphthalene sulfonates. [42 FR 14491, Mar. 15...

Assigning ecological roles to the populations belonging to a phenanthrene-degrading bacterial consortium using omic approaches

PubMed Central

Coppotelli, Bibiana Marina; Madueño, Laura; Loviso, Claudia Lorena; Macchi, Marianela; Neme Tauil, Ricardo Martin; Valacco, María Pía; Morelli, Irma Susana

2017-01-01

The present study describes the behavior of a natural phenanthrene-degrading consortium (CON), a synthetic consortium (constructed with isolated strains from CON) and an isolated strain form CON (Sphingobium sp. AM) in phenanthrene cultures to understand the interactions among the microorganisms present in the natural consortium during phenanthrene degradation as a sole carbon and energy source in liquid cultures. In the contaminant degradation assay, the defined consortium not only achieved a major phenanthrene degradation percentage (> 95%) but also showed a more efficient elimination of the intermediate metabolite. The opposite behavior occurred in the CON culture where the lowest phenanthrene degradation and the highest HNA accumulation were observed, which suggests the presence of positive and also negative interaction in CON. To consider the uncultured bacteria present in CON, a metagenomic library was constructed with total CON DNA. One of the resulting scaffolds (S1P3) was affiliated with the Betaproteobacteria class and resulted in a significant similarity with a genome fragment from Burkholderia sp. HB1 chromosome 1. A complete gene cluster, which is related to one of the lower pathways (meta-cleavage of catechol) involved in PAH degradation (ORF 31–43), mobile genetic elements and associated proteins, was found. These results suggest the presence of at least one other microorganism in CON besides Sphingobium sp. AM, which is capable of degrading PAH through the meta-cleavage pathway. Burkholderiales order was further found, along with Sphingomonadales order, by a metaproteomic approach, which indicated that both orders were metabolically active in CON. Our results show the presence of negative interactions between bacterial populations found in a natural consortium selected by enrichment techniques; moreover, the synthetic syntrophic processing chain with only one microorganism with the capability of degrading phenanthrene was more efficient in contaminant and intermediate metabolite degradation than a generalist strain (Sphingobium sp. AM). PMID:28886166

POLYMERIZATION AND COPOLYMERIZATION OF TETRACYANOETHYLENE UNDER THE EFFECT OF POLYMERS WITH A CONJUGATED SYSTEM,

DTIC Science & Technology

reactivity monomers such as tetracyanoethylene (I), anthracene, naphthacene and pentacene . I was polymerized alone or copolymerized with anthracene...naphthacene, or pentacene . Soluble fractions of polyphenylene or polyanthryl were used as the catalyst in various concentrations so as to vary the...magnitude as high as that of anthracene, and had an activation energy of 8-11 kcal/mol. Naphthacene, pentacene , and polyphenylene also copolymerized

Data on synthesis and thermo-mechanical properties of stimuli-responsive rubber materials bearing pendant anthracene groups.

PubMed

Manhart, Jakob; Ayalur-Karunakaran, Santhosh; Radl, Simone; Oesterreicher, Andreas; Moser, Andreas; Ganser, Christian; Teichert, Christian; Pinter, Gerald; Kern, Wolfgang; Griesser, Thomas; Schlögl, Sandra

2016-12-01

The photo-reversible [4πs+4πs] cycloaddition reaction of pendant anthracene moieties represents a convenient strategy to impart wavelength dependent properties into hydrogenated carboxylated nitrile butadiene rubber (HXNBR) networks. The present article provides the 1 H NMR data on the reaction kinetics of the side chain functionalization of HXNBR. 2-(Anthracene-9-yl)oxirane with reactive epoxy groups is covalently attached to the polymer side chain of HXNBR via ring opening reaction between the epoxy and the carboxylic groups. Along with the identification, 1 H NMR data on the quantification of the attached functional groups are shown in dependence on reaction time and concentration of 2-(anthracene-9-yl)oxirane. Changes in the modification yield are reflected in the mechanical properties and DMA data of photo-responsive elastomers are illustrated in dependence on the number of attached anthracene groups. DMA curves over repeated cycles of UV induced crosslinking ( λ >300 nm) and UV induced cleavage ( λ =254 nm) are further depicted, demonstrating the photo-reversibility of the thermo-mechanical properties. Interpretation and discussion of the data are provided in "Design and application of photo-reversible elastomer networks by using the [4πs+4πs] cycloaddition reaction of pendant anthracene groups" (Manhart et al., 2016) [1].

An integrated biomarker response index for the mussel Mytilus edulis based on laboratory exposure to anthracene and field transplantation experiments

NASA Astrophysics Data System (ADS)

Yuan, Mengqi; Wang, You; Zhou, Bin; Jian, Xiaoyang; Dong, Wenlong; Tang, Xuexi

2017-09-01

Organic pollution is a serious environmental problem in coastal areas and it is important to establish quantitative methods for monitoring this pollution. This study screened a series of sensitive biomarkers to construct an integrated biomarker response (IBR) index using Mytilus edulis. Mussels were exposed to the polycyclic aromatic hydrocarbon anthracene under controlled laboratory conditions and the activities of components of the glutathione antioxidant system, and the concentrations of oxidative-damage markers, were measured in the gills and digestive glands. Anthracene exposure resulted in increased levels of malondialdehyde (MDA) and superoxide radicals (O 2 • ), indicating that oxidative damage had occurred. Correspondingly, anthracene exposure induced increased activities of glutathione S-transferase (GST), glutathione peroxidase (GPx) and reduced glutathione (GSH) in digestive glands, and GPx and glutathione reductase (GR) in gills, consistent with stimulation of the antioxidant system. A field experiment was set up, in which mussels from a relatively clean area were transplanted to a contaminated site. One month later, the activities of GST, GPx and GR had increased in several tissues, particularly in the digestive glands. Based on the laboratory experiment, an IBR, which showed a positive relationship with anthracene exposure, was constructed. The IBR is suggested to be a potentially useful tool for assessing anthracene pollution.

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

Longitudinal Study of [D10]Phenanthrene Metabolism by the Diol Epoxide Pathway in Smokers

PubMed Central

Hecht, Stephen S.; Hochalter, J. Bradley; Carmella, Steven G.; Zhang, Yan; Rauch, Diane M.; Fujioka, Naomi; Jensen, Joni; Hatsukami, Dorothy K.

2013-01-01

The extent of metabolism of [D10]phenanthrene to [D10]r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetradeuterophenanthrene ([D10]PheT) could be a biomarker of human metabolic activation of carcinogenic polycyclic aromatic hydrocarbons, leading to identification of smokers particularly susceptible to lung cancer. The longitudinal stability of [D10]PheT was evaluated in 24 cigarette smokers given 7 – 8 oral doses of [D10]phenanthrene (10 μg) over 5.5 months. [D10]PheT in 6 h urine was quantified after each dose. The overall coefficient of variation for 24 subjects was (mean ± S.D.) 27.4 ± 8.83%. Thus, a single administration of [D10]phenanthrene is likely sufficient to determine a smoker’s ability to metabolize it to [D10]PheT. PMID:23336104

Analyses of polycyclic aromatic hydrocarbon (PAH) and chiral-PAH analogues-methyl-β-cyclodextrin guest-host inclusion complexes by fluorescence spectrophotometry and multivariate regression analysis.

PubMed

Greene, LaVana; Elzey, Brianda; Franklin, Mariah; Fakayode, Sayo O

2017-03-05

The negative health impact of polycyclic aromatic hydrocarbons (PAHs) and differences in pharmacological activity of enantiomers of chiral molecules in humans highlights the need for analysis of PAHs and their chiral analogue molecules in humans. Herein, the first use of cyclodextrin guest-host inclusion complexation, fluorescence spectrophotometry, and chemometric approach to PAH (anthracene) and chiral-PAH analogue derivatives (1-(9-anthryl)-2,2,2-triflouroethanol (TFE)) analyses are reported. The binding constants (K b ), stoichiometry (n), and thermodynamic properties (Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS)) of anthracene and enantiomers of TFE-methyl-β-cyclodextrin (Me-β-CD) guest-host complexes were also determined. Chemometric partial-least-square (PLS) regression analysis of emission spectra data of Me-β-CD-guest-host inclusion complexes was used for the determination of anthracene and TFE enantiomer concentrations in Me-β-CD-guest-host inclusion complex samples. The values of calculated K b and negative ΔG suggest the thermodynamic favorability of anthracene-Me-β-CD and enantiomeric of TFE-Me-β-CD inclusion complexation reactions. However, anthracene-Me-β-CD and enantiomer TFE-Me-β-CD inclusion complexations showed notable differences in the binding affinity behaviors and thermodynamic properties. The PLS regression analysis resulted in square-correlation-coefficients of 0.997530 or better and a low LOD of 3.81×10 -7 M for anthracene and 3.48×10 -8 M for TFE enantiomers at physiological conditions. Most importantly, PLS regression accurately determined the anthracene and TFE enantiomer concentrations with an average low error of 2.31% for anthracene, 4.44% for R-TFE and 3.60% for S-TFE. The results of the study are highly significant because of its high sensitivity and accuracy for analysis of PAH and chiral PAH analogue derivatives without the need of an expensive chiral column, enantiomeric resolution, or use of a polarized light. Published by Elsevier B.V.

Effects of oil dispersants on photodegradation of parent and alkylated anthracene in seawater.

PubMed

Cai, Zhengqing; Liu, Wen; Fu, Jie; O'Reilly, S E; Zhao, Dongye

2017-10-01

This study investigated effects of three model oil dispersants on photodegradation of two model PAHs (anthracene and 9,10-dimethyanthracene (9,10-DMA)) under simulated sunlight. All three dispersants, i.e. Corexit EC9500A, Corexit EC9527A and SPC 1000, promoted the photolysis rate of 9,10-DMA, following the order of Corexit EC9500A > Corexit EC9527A > SPC 1000. The photodegradation rate was well interpreted by a two-stage, first-order kinetic law with a faster initial photolysis rate in the presence of the dispersants. Span 80, Tween 85 and kerosene were found as the key dispersant components, of which Span 80 and Tween 85 promoted the photodegradation by boosting absorbance of solar irradiation while kerosene by dispersing more PAHs in the upper layer of the water column. Dissolved oxygen (DO) inhibited photolysis of anthracene regardless of dispersant resulting from quenching the excited states of the PAH, while DO facilitated photolysis of 9,10-DMA due to the formation singlet oxygen ( 1 O 2 ) radicals in the presence of oil dispersants. The other ROS, i.e. •O 2 - and •OH, played a negligible role on the photodegradation of anthracene and 9,10-DMA. Fluorescence analysis showed that more anthracene was associated with dispersant than 9,10-DMA, which favored the direct transfer of energy to anthracene, while energy is more likely transferred to oxygen to form 1 O 2 in the case of 9,10-DMA. Direct photolysis dominated the photodegradation of anthracene and 9,10-DMA. Both direct ionization of anthracene and the electron transfer from excited 9,10-DMA to oxygen can lead to formation of the corresponding PAH radical cations. Overall, the oil dispersants accelerated the photolysis rates of the PAHs without altering the degradation pathway. The findings are useful for understanding photochemical weathering of dispersed oil components in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

2-(Naphthalen-1-yl)-4-(naphthalen-1-yl­methyl­idene)-1,3-oxazol-5(4H)-one

PubMed Central

Gündoğdu, Cevher; Alp, Serap; Ergün, Yavuz; Tercan, Barış; Hökelek, Tuncer

2011-01-01

In the title compound, C24H15NO2, the oxazole ring is oriented at dihedral angles of 10.09 (4) and 6.04 (4)° with respect to the mean planes of the naphthalene ring systems, while the two naphthalene ring systems make a dihedral angle of 4.32 (3)°. Intra­molecular C—H⋯N hydrogen bonds link the oxazole N atom to the naphthalene ring systems. In the crystal, inter­molecular weak C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. π–π contacts between the oxazole and naphthalene rings and between the naphthalene ring systems [centroid–centroid distances = 3.5947 (9) and 3.7981 (9) Å] may further stabilize the crystal structure. Three weak C—H⋯π inter­actions also occur. PMID:21754548

Effects of nano bamboo charcoal on PAHs-degrading strain Sphingomonas sp. GY2B.

PubMed

She, Bojia; Tao, Xueqin; Huang, Ting; Lu, Guining; Zhou, Zhili; Guo, Chuling; Dang, Zhi

2016-03-01

Nano bamboo charcoal (NBC) has been commonly used in the production of textiles, plastics, paint, etc. However, little is known regarding their effects towards the microorganisms. The effects of NBC on phenanthrene degrading strain Sphingomonas sp. GY2B were investigated in the present study. Results showed that the addition of NBC could improve the phenanthrene removal by Sphingomonas sp. GY2B, with removal efficiencies increased by 10.29-18.56% in comparison to the control at 24h, and phenanthrene was almost completely removed at 48h. With the presence of low dose of NBC (20 and 50mgL(-1)), strain GY2B displayed a better growth at 6h, suggesting that NBC was beneficial to the growth of GY2B and thus resulting in the quick removal of phenanthrene from water. However, the growth of strain GY2B in high dose of NBC (200mgL(-1)) was inhibited at 6h, and the inhibition could be attenuated and eliminated after 12h. NBC-effected phenanthrene solubility experiment suggested that NBC makes a negligible contribution to the solubilization of phenanthrene in water. Results of electronic microscopy analysis (SEM and TEM) indicated NBC may interact with the cell membrane, causing the enhanced membrane permeability and then NBC adsorbed on the membrane would enter into the cells. The findings of this work would provide important information for the future usage and long-term environmental risk assessment of NBC. Copyright © 2015 Elsevier Inc. All rights reserved.

STABILITY OF HEMOGLOBIN AND ALBUMIN ADDUCTS OF NAPHTHALENE OXIDE, 1,2-NAPHTHOQUINONE, AND 1,4-NAPHTHOQUINONE

EPA Science Inventory

Naphthalene is an important industrial chemical, which has recently been shown to cause tumors of the respiratory tract in rodents. It is thought that one or more reactive metabolites of naphthalene, namely, naphthalene-1,2-oxide (NPO), 1,2-naphthoquinone (1,2-NPQ), and 1,4-na...

[Degradation characteristics of naphthalene with a Pseudomonas aeruginosa strain isolated from soil contaminated by diesel].

PubMed

Liu, Wen-Chao; Wu, Bin-Bin; Li, Xiao-Sen; Lu, Dian-Nan; Liu, Yong-Min

2015-02-01

Abstract: A naphthalene-degrading bacterium (referred as HD-5) was isolated from the diesel-contaminated soil and was assigned to Pseudomonas aeruginosa according to 16S rDNA sequences analysis. Gene nah, which encodes naphthalene dioxygenase, was identified from strain HD-5 by PCR amplification. Different bioremediation approaches, including nature attenuation, bioaugmentation with strain Pseudomonas aeruginosa, biostimulation, and an integrated degradation by bioaugmentation and biostimulation, were evaluated for their effectiveness in the remediating soil containing 5% naphthalene. The degradation rates of naphthalene in the soil were compared among the different bioremediation approaches, the FDA and dehydrogenase activity in bioremediation process were measured, and the gene copy number of 16S rRNA and nah in soil were dynamically monitored using real-time PCR. It was shown that the naphthalene removal rate reached 71.94%, 62.22% and 83.14% in approaches of bioaugmentation (B), biostimulation(S) and integrated degradation composed of bioaugmentation and biostimulation (BS), respectively. The highest removal rate of naphthalene was achieved by using BS protocol, which also gives the highest FDA and dehydrogenase activity. The gene copy number of 16S rRNA and nah in soil increased by about 2.67 x 10(11) g(-1) and 8.67 x 10(8) g(-1) after 31 days treatment using BS protocol. Above-mentioned results also demonstrated that the screened bacterium, Pseudomonas aeruginosa, could grow well in naphthalene-contaminated soil and effectively degrade naphthalene, which is of fundamental importance for bioremediation of naphthalene-contaminated soil.

Use of antioxidant enzymes of clam Ruditapes philippinarum as biomarker to polycyclic aromatic hydrocarbon pollution

NASA Astrophysics Data System (ADS)

Zhu, Lin; Tang, Xuexi; Wang, Ying; Sui, Yadong; Xiao, Hui

2016-03-01

The typical organic pollutant polycyclic aromatic hydrocarbon (PAH) anthracene was selected as a contaminant to investigate its effects on the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the clam Ruditapes philippinarum. The results show that SOD, CAT and GSH-Px had diff erent induction and inhibition reactions to anthracene stress, and that three diff erent organs in R. philippinarum (visceral mass, muscle tissue and mantle) had diff erent sensitivities to anthracene stress. This study suggest that SOD activities of the visceral mass, CAT activitities of the mantle and the visceral mass, and GSH-Px activity of the muscle tissue could be used as sensitive indicators of anthracene stress in R. philippinarum.

Changes in bacterial community of anthracene bioremediation in municipal solid waste composting soil*

PubMed Central

Zhang, Shu-ying; Wang, Qing-feng; Wan, Rui; Xie, Shu-guang

2011-01-01

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in a municipal solid waste (MSW) composting site. Knowledge of changes in microbial structure is useful to identify particular PAH degraders. However, the microbial community in the MSW composting soil and its change associated with prolonged exposure to PAHs and subsequent biodegradation remain largely unknown. In this study, anthracene was selected as a model compound. The bacterial community structure was investigated using terminal restriction fragment length polymorphism (TRFLP) and 16S rRNA gene clone library analysis. The two bimolecular tools revealed a large shift of bacterial community structure after anthracene amendment and subsequent biodegradation. Genera Methylophilus, Mesorhizobium, and Terrimonas had potential links to anthracene biodegradation, suggesting a consortium playing an active role. PMID:21887852

Partition characteristics of polycyclic aromatic hydrocarbons on soils and sediments

USGS Publications Warehouse

Chiou, C.T.; Mcgroddy, S.E.; Kile, D.E.

1998-01-01

The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., K(oc) values) are relatively invariant either for the 'clean' (uncontaminated) soils or for the clean sediments; however, the mean K(oc) values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in K(oc) are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher K(oc) values. At given K(ow) values (octanol-water), the PAHs exhibit much higher K(oc) values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower K(ow) values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log K(oc) and log K(ow) for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., Koc values) are relatively invariant either for the `clean' (uncontaminated) soils or for the clean sediments; however, the mean Koc values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in Koc are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher Koc values. At given Kow values (octanol-water), the PAHs exhibit much higher Koc values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower Kow values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log Koc and log Kow for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure

PubMed Central

Kang-Sickel, Juei-Chuan C.; Butler, Mary Ann; Frame, Lynn; Serdar, Berrin; Chao, Yi-Chun E.; Egeghy, Peter; Rappaport, Stephen M.; Toennis, Christine A.; Li, Wang; Borisova, Tatyana; French, John E.; Nylander-French, Leena A.

2014-01-01

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+−) genotypes were associated with a decrease in urine naphthalene level (p < 0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure. PMID:21961652

Preservation of commonly applied fluorescent tracers in complex water samples

NASA Astrophysics Data System (ADS)

Cao, Viet; Schaffer, Mario; Jin, Yulan; Licha, Tobias

2017-06-01

Water sample preservation and pre-treatment are important steps for achieving accurate and reproductive results from tracer tests. However, this is particularly challenging for complex water mixtures prior to fluorescence analysis. In this study, the interference of iron and calcium precipitation with nine commonly applied conservative tracers, uranine, eosin, 1-naphthalene sulfonate, 1,5-naphthalene disulfonate, 2,6-naphthalene disulfonate, 4-amino-1-naphthalene sulfonate, 6-hydroxy-2-naphthalene sulfonate, 1,3,6-naphthalene trisulfonate, and 1,3,6,8-pyrene tetrasulfonate, was investigated in batch experiments. In general, the observed results are influenced by precipitates. A technique consisting of pH adjustment and centrifugation is described for preserving samples and avoiding the impact of these precipitates on the tracer test results.

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure.

PubMed

Kang-Sickel, Juei-Chuan C; Butler, Mary Ann; Frame, Lynn; Serdar, Berrin; Chao, Yi-Chun E; Egeghy, Peter; Rappaport, Stephen M; Toennis, Christine A; Li, Wang; Borisova, Tatyana; French, John E; Nylander-French, Leena A

2011-11-01

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+-) genotypes were associated with a decrease in urine naphthalene level (p < 0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure.

Comparison between Soil- and Biochar-Derived Humic Acids: Composition, Conformation, and Phenanthrene Sorption.

PubMed

Jin, Jie; Sun, Ke; Yang, Yan; Wang, Ziying; Han, Lanfang; Wang, Xiangke; Wu, Fengchang; Xing, Baoshan

2018-02-20

Biochar-derived organic matter (BDOM) plays an important role in determining biochar's application potential in soil remediation. However, little is known about the physicochemical properties of BDOM and its sorption of hydrophobic organic compounds (HOCs). Humic acids (HAs) were extracted from oxidized biochars produced from plant straws and animal manures at 450 °C, and their sorption of phenanthrene, a representative of HOCs, was investigated. The organic carbon recovery of biochar-derived HAs (BDHAs) was 13.9-69.3%. The 13 C NMR spectra of BDHAs mainly consisted of aromatic and carboxylic C, while those of soil-derived HAs (SDHAs) contained abundant signals in aliphatic region. BDHAs and SDHAs had comparable CO 2 cumulative surface areas. BDHAs were found to exhibit higher phenanthrene sorption than SDHAs. After the removal of amorphous aromatic components, the logK oc values of BDHAs were significantly decreased, implying that amorphous aromatic C regulated phenanthrene sorption by BDHAs. In contrast, aliphatic moieties dominated phenanthrene sorption by SDHAs, as evidenced by the enhanced sorption after the removal of amorphous aromatics. This study clearly demonstrated the contrasting characteristics and sorption behaviors of BDHA and SDHA, indicating that biochar addition and subsequent weathering could greatly affect native organic matter properties and the fate of HOCs in biochar-amended soils.

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

Time trends of polycyclic aromatic hydrocarbon exposure in New York City from 2001 to 2012: assessed by repeat air and urine samples.

PubMed

Jung, Kyung Hwa; Liu, Bian; Lovinsky-Desir, Stephanie; Yan, Beizhan; Camann, David; Sjodin, Andreas; Li, Zheng; Perera, Frederica; Kinney, Patrick; Chillrud, Steven; Miller, Rachel L

2014-05-01

Exposure to air pollutants including polycyclic aromatic hydrocarbons (PAH), and specifically pyrene from combustion of fuel oil, coal, traffic and indoor sources, has been associated with adverse respiratory health outcomes. However, time trends of airborne PAH and metabolite levels detected via repeat measures over time have not yet been characterized. We hypothesized that PAH levels, measured repeatedly from residential indoor and outdoor monitors, and children׳s urinary concentrations of PAH metabolites, would decrease following policy interventions to reduce traffic-related air pollution. Indoor PAH (particle- and gas-phase) were collected for two weeks prenatally (n=98), at age 5/6 years (n=397) and age 9/10 years (n=198) since 2001 and at all three age-points (n=27). Other traffic-related air pollutants (black carbon and PM2.5) were monitored indoors simultaneous with PAH monitoring at ages 5/6 (n=403) and 9/10 (n=257) between 2005 and 2012. One third of the homes were selected across seasons for outdoor PAH, BC and PM2.5 sampling. Using the same sampling method, ambient PAH, BC and PM2.5 also were monitored every two weeks at a central site between 2007 and 2012. PAH were analyzed as semivolatile PAH (e.g., pyrene; MW 178-206) (∑8PAH(semivolatile): Including pyrene (PYR), phenanthrene (PHEN), 1-methylphenanthrene (1-MEPH), 2-methylphenanthrene (2-MEPH), 3-methylphenanthrene (3-MEPH), 9-methylphenanthrene (9-MEPH), 1,7-dimethylphenanthrene (1,7-DMEPH), and 3,6-dimethylphenanthrene (3,6-DMEPH)) and the sum of eight nonvolatile PAH (∑8PAH(nonvolatile): Including benzo[a]anthracene (BaA), chrysene/iso-chrysene (Chry), benzo[b]fluoranthene (BbFA), benzo[k]fluoranthene (BkFA), benzo[a]pyrene (BaP), indeno[1,2,3-c,d]pyrene (IP), dibenzo[a,h]anthracene (DahA), and benzo[g,h,i]perylene (BghiP); MW 228-278). A spot urine sample was collected from children at child ages 3, 5, 7 and 9 between 2001 and 2012 and analyzed for 10 PAH metabolites. Modest declines were detected in indoor BC and PM2.5 levels between 2005 and 2012 (Annual percent change [APC]=-2.08% [p=0.010] and -2.18% [p=0.059] for BC and PM2.5, respectively), while a trend of increasing pyrene levels was observed in indoor and outdoor samples, and at the central site during the comparable time periods (APC=4.81%, 3.77% and 7.90%, respectively; p<0.05 for all). No significant time trend was observed in indoor ∑8PAH(nonvolatile) levels between 2005 and 2012; however, significant opposite trends were detected when analyzed seasonally (APC=-8.06% [p<0.01], 3.87% [p<0.05] for nonheating and heating season, respectively). Similarly, heating season also affected the annual trends (2005-2012) of other air pollutants: the decreasing BC trend (in indoor/outdoor air) was observed only in the nonheating season, consistent with dominating traffic sources that decreased with time; the increasing pyrene trend was more apparent in the heating season. Outdoor PM2.5 levels persistently decreased over time across the seasons. With the analyses of data collected over a longer period of time (2001-2012), a decreasing trend was observed in pyrene (APC=-2.76%; p<0.01), mostly driven by measures from the nonheating season (APC=-3.54%; p<0.01). In contrast, levels of pyrene and naphthalene metabolites, 1-hydroxypyrene and 2-naphthol, increased from 2001 to 2012 (APC=6.29% and 7.90% for 1-hydroxypyrene and 2-naphthol, respectively; p<0.01 for both). Multiple NYC legislative regulations targeting traffic-related air pollution may have led to decreases in ∑8PAH(nonvolatile) and BC, especially in the nonheating season. Despite the overall decrease in pyrene over the 2001-2012 periods, a rise in pyrene levels in recent years (2005-2012), that was particularly evident for measures collected during the heating season, and 2-naphthol, indicates the contribution of heating oil combustion and other indoor sources to airborne pyrene and urinary 2-naphthol. Copyright © 2014 Elsevier Inc. All rights reserved.