Science.gov

Sample records for hydrocarbon source allocation

  1. Source allocation by least-squares hydrocarbon fingerprint matching.

    PubMed

    Burns, William A; Mudge, Stephen M; Bence, A Edward; Boehm, Paul D; Brown, John S; Page, David S; Parker, Keith R

    2006-11-01

    There has been much controversy regarding the origins of the natural polycyclic aromatic hydrocarbon (PAH) and chemical biomarker background in Prince William Sound (PWS), Alaska, site of the 1989 Exxon Valdez oil spill. Different authors have attributed the sources to various proportions of coal, natural seep oil, shales, and stream sediments. The different probable bioavailabilities of hydrocarbons from these various sources can affect environmental damage assessments from the spill. This study compares two different approaches to source apportionment with the same data (136 PAHs and biomarkers) and investigate whether increasing the number of coal source samples from one to six increases coal attributions. The constrained least-squares (CLS) source allocation method that fits concentrations meets geologic and chemical constraints better than partial least-squares (PLS) which predicts variance. The field data set was expanded to include coal samples reported by others, and CLS fits confirm earlier findings of low coal contributions to PWS.

  2. Source allocation by least-squares hydrocarbon fingerprint matching

    SciTech Connect

    William A. Burns; Stephen M. Mudge; A. Edward Bence; Paul D. Boehm; John S. Brown; David S. Page; Keith R. Parker

    2006-11-01

    There has been much controversy regarding the origins of the natural polycyclic aromatic hydrocarbon (PAH) and chemical biomarker background in Prince William Sound (PWS), Alaska, site of the 1989 Exxon Valdez oil spill. Different authors have attributed the sources to various proportions of coal, natural seep oil, shales, and stream sediments. The different probable bioavailabilities of hydrocarbons from these various sources can affect environmental damage assessments from the spill. This study compares two different approaches to source apportionment with the same data (136 PAHs and biomarkers) and investigate whether increasing the number of coal source samples from one to six increases coal attributions. The constrained least-squares (CLS) source allocation method that fits concentrations meets geologic and chemical constraints better than partial least-squares (PLS) which predicts variance. The field data set was expanded to include coal samples reported by others, and CLS fits confirm earlier findings of low coal contributions to PWS. 15 refs., 5 figs.

  3. A principal-component and least-squares method for allocating polycyclic aromatic hydrocarbons in sediment to multiple sources

    SciTech Connect

    Burns, W.A.; Mankiewicz, P.J.; Bence, A.E.; Page, D.S.; Parker, K.R.

    1997-06-01

    A method was developed to allocate polycyclic aromatic hydrocarbons (PAHs) in sediment samples to the PAH sources from which they came. The method uses principal-component analysis to identify possible sources and a least-squares model to find the source mix that gives the best fit of 36 PAH analytes in each sample. The method identified 18 possible PAH sources in a large set of field data collected in Prince William Sound, Alaska, USA, after the 1989 Exxon Valdez oil spill, including diesel oil, diesel soot, spilled crude oil in various weathering states, natural background, creosote, and combustion products from human activities and forest fires. Spill oil was generally found to be a small increment of the natural background in subtidal sediments, whereas combustion products were often the predominant sources for subtidal PAHs near sites of past or present human activity. The method appears to be applicable to other situations, including other spills.

  4. Biological sources for phenylalkane hydrocarbons

    SciTech Connect

    Ellis, L.; Winans, R.E.; Langworthy, T.A.; Langworthy, T.A.

    1996-12-31

    Linear alkylbenzenes (phenylalkanes) represent an important class of molecular compounds used widely in today`s society as building blocks for detergent manufacture, indeed, the almost universal widespread use and acceptance of detergents has been reflected by the fact that detergent chemical components can be found in and around almost every location around the globe where human settlements exist. This being the case, detergent chemical components represent a well recognized indicator of pollution in the lakes, rivers, and coastal water systems of the world. The identification of phenylalkane hydrocarbons in ancient sedimentary organic matter has been the subject of much controversy and concern, owing to the ubiquitous presence of phenylalkanes in today`s society. The finding of these components in the trace analytical analyses of petroleum sediments and crude oils has always implied {open_quotes}detergent contamination{close_quotes}. New evidence, however, suggests that the finding of phenylalkanes in ancient geological materials may actually represent an input from ancient algae and/or bacteria which contributed to the organic biomass from which the sediment or crude oil was derived. Moreover, the finding also of phenylalkane hydrocarbons in the lipids extracts of thermophilic bacteria still living today has revealed the first evidence of a natural system producing these compounds.

  5. Atmospheric distribution and sources of nonmethane hydrocarbons

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Zimmerman, Patrick B.

    1992-01-01

    The paper discusses the atmospheric distribution of natural and man-made nonmethane hydrocarbons (NMHCs), the major species of airborne NMHCs, and their sources and sinks. Particular attention is given to the techniques for measuring atmospheric NMHCs; diurnal and seasonal variations of atmospheric NMHCs and differences between rural, urban, and marine environments; latitudinal and vertical distributions; and available stratospheric NMHC measurements. A formula defining the atmospheric lifetime of a NMHC from its reaction rates with OH and O3 is presented.

  6. Hydrocarbon source potential in Brazilian margin basins

    SciTech Connect

    Mello, M.R.; Estrella, G.D.O.; Gaglianone, P.C.

    1984-04-01

    Twenty thousand samples from the Brazilian continental shelf basins were analyzed to characterize and evaluate the hydrocarbon source potential of the areas. The geochemical evaluation of the rock and oil samples was performed by organic carbon determinations, Rock-Eval pyrolysis, vitrinite reflectance, thermal alteration index, liquid and gas chromatographies, gas chromatography-mass spectrometry, and carbon isotope analyses. Three source rock systems have been identified: lower Neocomian shales deposited in a continental environment, upper Neocomian shales grading from continental to lagoonal environment, and Aptian shales related to evaporitic and lacustrine sequences. Upper Cretaceous and Tertiary open marine slope sediments are not considered as source rocks. Locally, these sediments present high organic carbon content but show an extremely poor hydrocarbon yield. Anoxic depositional conditions, nevertheless, can be traced locally along some levels of the Santonian to Cenomanian shales and marls. These sediments are generally immature in the Brazilian margin basins and no oil was generated from this section. Three oil families were distinguished through oil-to-oil and oil-to-source rock correlations: the lower Neocomian continental type, the upper Neocomian continental to lagoonal type, and the Aptian evaporitic to lacustrine related sequences. The geochemical studies, together with geologic and geophysical data, provided the basis to display some models for the migration pathways and habitat of oils in the Brazilian margin basins.

  7. Dynamic state allocation for MEG source reconstruction.

    PubMed

    Woolrich, Mark W; Baker, Adam; Luckhoo, Henry; Mohseni, Hamid; Barnes, Gareth; Brookes, Matthew; Rezek, Iead

    2013-08-15

    Our understanding of the dynamics of neuronal activity in the human brain remains limited, due in part to a lack of adequate methods for reconstructing neuronal activity from noninvasive electrophysiological data. Here, we present a novel adaptive time-varying approach to source reconstruction that can be applied to magnetoencephalography (MEG) and electroencephalography (EEG) data. The method is underpinned by a Hidden Markov Model (HMM), which infers the points in time when particular states re-occur in the sensor space data. HMM inference finds short-lived states on the scale of 100ms. Intriguingly, this is on the same timescale as EEG microstates. The resulting state time courses can be used to intelligently pool data over these distinct and short-lived periods in time. This is used to compute time-varying data covariance matrices for use in beamforming, resulting in a source reconstruction approach that can tune its spatial filtering properties to those required at different points in time. Proof of principle is demonstrated with simulated data, and we demonstrate improvements when the method is applied to MEG.

  8. Joint source-channel rate allocation in parallel channels.

    PubMed

    Pu, Lingling; Marcellin, Michael W; Djordjevic, Ivan; Vasic, Bane; Bilgin, Ali

    2007-08-01

    A fast rate-optimal rate allocation algorithm is proposed for parallel transmission of scalable images in multichannel systems. Scalable images are transmitted via fixed-length packets. The proposed algorithm selects a subchannel, as well as a channel code rate for each packet, based on the signal-to-noise ratios (SNRs) of the subchannels. The resulting scheme provides unequal error protection of source bits and significant gains are obtained over equal error protection schemes. An application of the proposed algorithm to JPEG2000 transmission shows the advantages of exploiting differences in SNRs between subchannels. Multiplexing of multiple sources is also considered, and additional gains are achieved by exploiting information diversity among the sources.

  9. Sources and resources: importance of nutrients, resource allocation, and ecology in microalgal cultivation for lipid accumulation.

    PubMed

    Fields, Matthew W; Hise, Adam; Lohman, Egan J; Bell, Tisza; Gardner, Rob D; Corredor, Luisa; Moll, Karen; Peyton, Brent M; Characklis, Gregory W; Gerlach, Robin

    2014-06-01

    Regardless of current market conditions and availability of conventional petroleum sources, alternatives are needed to circumvent future economic and environmental impacts from continued exploration and harvesting of conventional hydrocarbons. Diatoms and green algae (microalgae) are eukaryotic photoautotrophs that can utilize inorganic carbon (e.g., CO2) as a carbon source and sunlight as an energy source, and many microalgae can store carbon and energy in the form of neutral lipids. In addition to accumulating useful precursors for biofuels and chemical feed stocks, the use of autotrophic microorganisms can further contribute to reduced CO2 emissions through utilization of atmospheric CO2. Because of the inherent connection between carbon, nitrogen, and phosphorus in biological systems, macronutrient deprivation has been proven to significantly enhance lipid accumulation in different diatom and algae species. However, much work is needed to understand the link between carbon, nitrogen, and phosphorus in controlling resource allocation at different levels of biological resolution (cellular versus ecological). An improved understanding of the relationship between the effects of N, P, and micronutrient availability on carbon resource allocation (cell growth versus lipid storage) in microalgae is needed in conjunction with life cycle analysis. This mini-review will briefly discuss the current literature on the use of nutrient deprivation and other conditions to control and optimize microalgal growth in the context of cell and lipid accumulation for scale-up processes.

  10. Role of metabolite transporters in source-sink carbon allocation

    PubMed Central

    Ludewig, Frank; Flügge, Ulf-Ingo

    2013-01-01

    Plants assimilate carbon dioxide during photosynthesis in chloroplasts. Assimilated carbon is subsequently allocated throughout the plant. Generally, two types of organs can be distinguished, mature green source leaves as net photoassimilate exporters, and net importers, the sinks, e.g., roots, flowers, small leaves, and storage organs like tubers. Within these organs, different tissue types developed according to their respective function, and cells of either tissue type are highly compartmentalized. Photoassimilates are allocated to distinct compartments of these tissues in all organs, requiring a set of metabolite transporters mediating this intercompartmental transfer. The general route of photoassimilates can be briefly described as follows. Upon fixation of carbon dioxide in chloroplasts of mesophyll cells, triose phosphates either enter the cytosol for mainly sucrose formation or remain in the stroma to form transiently stored starch which is degraded during the night and enters the cytosol as maltose or glucose to be further metabolized to sucrose. In both cases, sucrose enters the phloem for long distance transport or is transiently stored in the vacuole, or can be degraded to hexoses which also can be stored in the vacuole. In the majority of plant species, sucrose is actively loaded into the phloem via the apoplast. Following long distance transport, it is released into sink organs, where it enters cells as source of carbon and energy. In storage organs, sucrose can be stored, or carbon derived from sucrose can be stored as starch in plastids, or as oil in oil bodies, or – in combination with nitrogen – as protein in protein storage vacuoles and protein bodies. Here, we focus on transport proteins known for either of these steps, and discuss the implications for yield increase in plants upon genetic engineering of respective transporters. PMID:23847636

  11. Irregular spacing of heat sources for treating hydrocarbon containing formations

    DOEpatents

    Miller, David Scott [Katy, TX; Uwechue, Uzo Philip [Houston, TX

    2012-06-12

    A method for treating a hydrocarbon containing formation includes providing heat input to a first section of the formation from one or more heat sources located in the first section. Fluids are produced from the first section through a production well located at or near the center of the first section. The heat sources are configured such that the average heat input per volume of formation in the first section increases with distance from the production well.

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

    PubMed

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

    2015-01-01

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

  13. Accumulation, Allocation, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Soil-Brassica chinensis System

    PubMed Central

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

    2015-01-01

    Farmland soil and leafy vegetables accumulate more polycyclic aromatic hydrocarbons (PAHs) in suburban sites. In this study, 13 sampling areas were selected from vegetable fields in the outskirts of Xi’an, the largest city in northwestern China. The similarity of PAH composition in soil and vegetation was investigated through principal components analysis and redundancy analysis (RDA), rather than discrimination of PAH congeners from various sources. The toxic equivalent quantity of PAHs in soil ranged from 7 to 202 μg/kg d.w., with an average of 41 μg/kg d.w., which exceeded the agricultural/horticultural soil acceptance criteria for New Zealand. However, the cancer risk level posed by combined direct ingestion, dermal contact, inhalation of soil particles, and inhalation of surface soil vapor met the rigorous international criteria (1×10−6). The concentration of total PAHs was (1052±73) μg/kg d.w. in vegetation (mean±standard error). The cancer risks posed by ingestion of vegetation ranged from 2×10−5 to 2×10−4 with an average of 1.66×10−4, which was higher than international excess lifetime risk limits for carcinogens (1×10−4). The geochemical indices indicated that the PAHs in soil and vegetables were mainly from vehicle and crude oil combustion. Both the total PAHs in vegetation and bioconcentration factor for total PAHs (the ratio of total PAHs in vegetation to total PAHs in soil) increased with increasing pH as well as decreasing sand in soil. The total variation in distribution of PAHs in vegetation explained by those in soil reached 98% in RDA, which was statistically significant based on Monte Carlo permutation. Common pollution source and notable effects of soil contamination on vegetation would result in highly similar distribution of PAHs in soil and vegetation. PMID:25679782

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

    PubMed

    Sanches, S; Leitão, C; Penetra, A; Cardoso, V V; Ferreira, E; Benoliel, M J; Crespo, M T Barreto; Pereira, V J

    2011-09-15

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

  15. A Method for Source-load Allocation of Nutrients in Agricultural Watersheds

    NASA Astrophysics Data System (ADS)

    Burkart, M. R.; James, D. E.

    2001-12-01

    Identification of pollutant sources is critical to solving water resource contamination problems. Non-point sources of agricultural pollution provide substantial challenges to quantifying and allocating the sources of contaminants to streams. A method is presented for identifying the spatial variability of nitrogen and phosphorus sources and allocating proportional responsibility for source-reduction. The method is applied to data at scales ranging from hydrologic regions (2-digit hydrologic accounting units) of the Mississippi drainage basin to the public land survey grid in two small (14-digit) watersheds. A mass balance of nutrient sources and losses is estimated using georeferenced data derived from national to local digital data bases. Nitrogen excess is estimated by balancing sources associated with inorganic fertilizer, manure, crop fixation, mineralization of organic matter, and atmospheric redeposition of ammonia with losses from crop harvest, plant senescence, denitrification, and volatilization of manure and inorganic fertilizer. Phosphorus sources from inorganic fertilizer and manure are balanced with losses due to crop harvest. Allocation in regional units allows targeting of major pollutant source areas while smaller aggregation areas define greater ranges of source-loads useful for specific allocation. Manure sources control the distribution of excess nutrients at many scales, particularly in watersheds with uniform cropping systems. Absolute values of excess N sources provide substantially different allocation patterns than proportional values of total source-loads. Selection of aggregation scale is critical to source-load allocation needed to define TMDLs, monitor loads, and establish water-quality remediation strategies. >http://www.nstl.gov/pubs/burkart/trends/index.html

  16. Loss of volatile hydrocarbons from an LNAPL oil source

    USGS Publications Warehouse

    Baedecker, M.J.; Eganhouse, R.P.; Bekins, B.A.; Delin, G.N.

    2011-01-01

    The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period were analyzed for 25 VHCs. Compared to the composition of oil from the pipeline source, VHCs identified in oil from wells sampled in 2008 were 13 to 64% depleted. The magnitude of loss for the VHCs analyzed was toluene ≫ o-xylene, benzene, C6 and C10–12n-alkanes > C7–C9n-alkanes > m-xylene, cyclohexane, and 1- and 2-methylnaphthalene > 1,2,4-trimethylbenzene and ethylbenzene. Other VHCs including p-xylene, 1,3,5- and 1,2,3-trimethylbenzenes, the tetramethylbenzenes, methyl- and ethyl-cyclohexane, and naphthalene were not depleted during the time of the study. Water–oil and air–water batch equilibration simulations indicate that volatilization and biodegradation is most important for the C6–C9n-alkanes and cyclohexanes; dissolution and biodegradation is important for most of the other hydrocarbons. Depletion of the hydrocarbons in the oil pool is controlled by: the lack of oxygen and nutrients, differing rates of recharge, and the spatial distribution of oil in the aquifer. The mass loss of these VHCs in the 5 wells is between 1.6 and 7.4% in 29 years or an average annual loss of 0.06–0.26%/year. The present study shows that the composition of LNAPL changes over time and that these changes are spatially variable. This highlights the importance of characterizing the temporal and spatial variabilities of the source term in solute-transport models.

  17. Loss of volatile hydrocarbons from an LNAPL oil source

    NASA Astrophysics Data System (ADS)

    Baedecker, Mary Jo; Eganhouse, Robert P.; Bekins, Barbara A.; Delin, Geoffrey N.

    2011-11-01

    The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period were analyzed for 25 VHCs. Compared to the composition of oil from the pipeline source, VHCs identified in oil from wells sampled in 2008 were 13 to 64% depleted. The magnitude of loss for the VHCs analyzed was toluene ≫ o-xylene, benzene, C 6 and C 10-12n-alkanes > C 7-C 9n-alkanes > m-xylene, cyclohexane, and 1- and 2-methylnaphthalene > 1,2,4-trimethylbenzene and ethylbenzene. Other VHCs including p-xylene, 1,3,5- and 1,2,3-trimethylbenzenes, the tetramethylbenzenes, methyl- and ethyl-cyclohexane, and naphthalene were not depleted during the time of the study. Water-oil and air-water batch equilibration simulations indicate that volatilization and biodegradation is most important for the C 6-C 9n-alkanes and cyclohexanes; dissolution and biodegradation is important for most of the other hydrocarbons. Depletion of the hydrocarbons in the oil pool is controlled by: the lack of oxygen and nutrients, differing rates of recharge, and the spatial distribution of oil in the aquifer. The mass loss of these VHCs in the 5 wells is between 1.6 and 7.4% in 29 years or an average annual loss of 0.06-0.26%/year. The present study shows that the composition of LNAPL changes over time and that these changes are spatially variable. This highlights the importance of characterizing the temporal and spatial variabilities of the source term in solute-transport models.

  18. Receptor model source apportionment of nonmethane hydrocarbons in Mexico City.

    PubMed

    Mugica, V; Watson, J; Vega, E; Reyes, E; Ruiz, M E; Chow, J

    2002-03-29

    With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC) to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas), asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

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

    PubMed

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

    2013-06-01

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

  20. Sources of polycyclic aromatic hydrocarbons to the Hudson River Airshed

    NASA Astrophysics Data System (ADS)

    Lee, Jong Hoon; Gigliotti, Cari L.; Offenberg, John H.; Eisenreich, Steven J.; Turpin, Barbara J.

    2004-11-01

    Sources of polycyclic aromatic hydrocarbons (PAHs) to the Hudson River Estuary Airshed were investigated using positive matrix factorization (PMF). A three-city dataset was used to obtain common factor profiles. The contributions of each factor on each sampling day and site were then determined, and a sensitivity analysis was conducted. A stable eight-factor solution was identified. PMF was able to identify a factor associated with air-surface exchange. This factor contains low-molecular weight PAHs and was a dominant contributor to the measured PAHs concentrations. Factors linked to motor vehicle use (diesel and gasoline vehicle emissions and evaporative/uncombusted petroleum) and natural gas combustion were also major contributors. Motor vehicle combustion and oil combustion factors were the predominant contributors to particle-phase PAHs, while natural gas combustion, air-surface exchange, and evaporative/uncombusted petroleum factors made substantial contributions to gas-phase PAH concentrations. In contrast to fine particulate matter (PM2.5), which is dominated by regional transport, spatial variations in PAH concentrations suggest that PAH concentrations in the Hudson River Estuary Airshed are dominated by sources within the New York-New Jersey urban-industrial complex.

  1. Factors limiting potential of evaporites as hydrocarbon source rocks

    SciTech Connect

    Katz, B.J.; Bissada, K.K.; Wood, J.W.

    1987-05-01

    It is well established that evaporite-bearing sequences account for a substantial proportion of petroleum occurrences. Examples can be cited from the Mesozoic of the Middle East, the Cretaceous of Latin America, and many others. An examination of effective source rocks within these provinces reveals that carbonate facies generate the bulk of the hydrocarbons. The higher evaporites (gypsum, anhydrate, halite, etc) seldom contribute to the resource base. Geochemical analyses of the higher evaporites reveal low organic carbon contents and imperceptible pyrolysis yields. These observations are not consistent with many of the current concepts of organic matter accumulation in evaporite environments, which suggests that hypersalinity should be especially favorable because abundant nutrient supply enhances primary productivity and elevated salt content enhances preservation efficiency. Their recent studies on oxidation of labile phytoplankton remains and relative sedimentation rates of organic and inorganic constituents in hypersaline brines suggest that three factors contribute to the observed low concentrations of hydrogen-enriched organic matter in the higher evaporites: (1) the density contrast between hypersaline brines and suspended organic matter retards the settling rate of the organic matter and prolongs its exposure to oxidative processes; (2) high concentrations of sulfates, and possibly nitrates, provide a secondary oxidizer for labile phytoplankton remains; and (3) high precipitation rates of the evaporite minerals dilute any organic matter which reaches the sediment-water interface. This paper will examine these factors in the modern and ancient record and discuss their influence on source-bed distribution through time and space.

  2. Fate of hydrocarbon pollutants in source and non-source control sustainable drainage systems.

    PubMed

    Roinas, Georgios; Mant, Cath; Williams, John B

    2014-01-01

    Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of > 17,000 μg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.

  3. Calotropis procera as a source of plant hydrocarbons

    SciTech Connect

    Erdman, M.D.; Erdman, B.A.

    1981-01-01

    Hexane-Soxhlet extractions of oven-dried whole plants, stems, leaves and pods (less than or equal to 6 mo of age) yielded 4.35, 3.83, 5.13, and 9.37 weight % of hexane extract (HE), respectively The HE from whole plants had a density of 0.9299 g/cubic cm; 0.71% total ash; 9973.4 cal/g; and 78.03, 11.22, and 10.71% C, H, and O respectively. Similar values were obtained from stems, leaves, and pods when analyzed separately. MeOH-Soxhlet extractions of residues previously extracted with hexane yielded 16.14, 18.50, 12.15, and 20.98 weight % MeOH extract (ME) from whole plants, stems, leaves, and pods, respectively. The ME from whole-plant residues had a density of 1.2267 g/cubic cm; 12.05% total ash; 4647.4 cal/g; and 40.88, 6.86, and 30.05% C, H, and O respectively. Similar values were obtained from stems, leaves and pods when analyzed separately. Calotropis procera can be used as a renewable source of hydrocarbon fuels and intermediate energy resources.

  4. POLYCYCLIC AROMATIC HYDROCARBON CLUSTERS AS SOURCES OF INTERSTELLAR INFRARED EMISSION

    SciTech Connect

    Roser, J. E.; Ricca, A.

    2015-03-10

    Polycyclic aromatic hydrocarbons (or PAHs) have been the subject of astrochemical research for several decades as principal sources of the interstellar aromatic infrared emission bands. PAH clusters could possibly contribute to these emission bands, but a lack of data on their infrared properties has made this hypothesis difficult to evaluate. Here we investigate homogeneous neutral PAH clusters by measuring the mid-infrared absorption spectra of the five nonlinear PAH molecules phenanthrene, chrysene, pyrene, perylene, and benzo[ghi]perylene within solid argon ice at a fixed temperature of 5 K. We attribute observed spectral shifts in their principal absorption bands as a function of argon/PAH ratio to clustering of the PAH molecules within the argon matrix. These shifts are related to the cluster structures forming in the matrix and the topology of the monomer PAH molecule. We predict that interstellar PAH molecules that are relatively large (no fewer than 50 carbon atoms per molecule) and compact will have clusters that contribute to the asymmetrically red-shaded profile of the interstellar 11.2 μm emission band.

  5. Abiogenic formation of alkanes in the Earth's crust as a minor source for global hydrocarbon reservoirs.

    PubMed

    Sherwood Lollar, B; Westgate, T D; Ward, J A; Slater, G F; Lacrampe-Couloume, G

    2002-04-04

    Natural hydrocarbons are largely formed by the thermal decomposition of organic matter (thermogenesis) or by microbial processes (bacteriogenesis). But the discovery of methane at an East Pacific Rise hydrothermal vent and in other crustal fluids supports the occurrence of an abiogenic source of hydrocarbons. These abiogenic hydrocarbons are generally formed by the reduction of carbon dioxide, a process which is thought to occur during magma cooling and-more commonly-in hydrothermal systems during water-rock interactions, for example involving Fischer-Tropsch reactions and the serpentinization of ultramafic rocks. Suggestions that abiogenic hydrocarbons make a significant contribution to economic hydrocarbon reservoirs have been difficult to resolve, in part owing to uncertainty in the carbon isotopic signatures for abiogenic versus thermogenic hydrocarbons. Here, using carbon and hydrogen isotope analyses of abiogenic methane and higher hydrocarbons in crystalline rocks of the Canadian shield, we show a clear distinction between abiogenic and thermogenic hydrocarbons. The progressive isotopic trends for the series of C1-C4 alkanes indicate that hydrocarbon formation occurs by way of polymerization of methane precursors. Given that these trends are not observed in the isotopic signatures of economic gas reservoirs, we can now rule out the presence of a globally significant abiogenic source of hydrocarbons.

  6. Abiogenic formation of alkanes in the Earth's crust as a minor source for global hydrocarbon reservoirs

    NASA Astrophysics Data System (ADS)

    Sherwood Lollar, B.; Westgate, T. D.; Ward, J. A.; Slater, G. F.; Lacrampe-Couloume, G.

    2002-04-01

    Natural hydrocarbons are largely formed by the thermal decomposition of organic matter (thermogenesis) or by microbial processes (bacteriogenesis). But the discovery of methane at an East Pacific Rise hydrothermal vent and in other crustal fluids supports the occurrence of an abiogenic source of hydrocarbons. These abiogenic hydrocarbons are generally formed by the reduction of carbon dioxide, a process which is thought to occur during magma cooling and-more commonly-in hydrothermal systems during water-rock interactions, for example involving Fischer-Tropsch reactions and the serpentinization of ultramafic rocks. Suggestions that abiogenic hydrocarbons make a significant contribution to economic hydrocarbon reservoirs have been difficult to resolve, in part owing to uncertainty in the carbon isotopic signatures for abiogenic versus thermogenic hydrocarbons. Here, using carbon and hydrogen isotope analyses of abiogenic methane and higher hydrocarbons in crystalline rocks of the Canadian shield, we show a clear distinction between abiogenic and thermogenic hydrocarbons. The progressive isotopic trends for the series of C1-C4 alkanes indicate that hydrocarbon formation occurs by way of polymerization of methane precursors. Given that these trends are not observed in the isotopic signatures of economic gas reservoirs, we can now rule out the presence of a globally significant abiogenic source of hydrocarbons.

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

    PubMed Central

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

    2013-01-01

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

  8. 40 CFR 74.28 - Allowance allocation for combustion sources becoming opt-in sources on a date other than January 1.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Allowance allocation for combustion... Allowance Calculations for Combustion Sources § 74.28 Allowance allocation for combustion sources becoming... by Calendar Quarter. Where a combustion source's opt-in permit becomes effective on April 1, July...

  9. 40 CFR 74.28 - Allowance allocation for combustion sources becoming opt-in sources on a date other than January 1.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Allowance allocation for combustion... Allowance Calculations for Combustion Sources § 74.28 Allowance allocation for combustion sources becoming... by Calendar Quarter. Where a combustion source's opt-in permit becomes effective on April 1, July...

  10. Optimizing Irrigation Water Allocation under Multiple Sources of Uncertainty in an Arid River Basin

    NASA Astrophysics Data System (ADS)

    Wei, Y.; Tang, D.; Gao, H.; Ding, Y.

    2015-12-01

    Population growth and climate change add additional pressures affecting water resources management strategies for meeting demands from different economic sectors. It is especially challenging in arid regions where fresh water is limited. For instance, in the Tailanhe River Basin (Xinjiang, China), a compromise must be made between water suppliers and users during drought years. This study presents a multi-objective irrigation water allocation model to cope with water scarcity in arid river basins. To deal with the uncertainties from multiple sources in the water allocation system (e.g., variations of available water amount, crop yield, crop prices, and water price), the model employs a interval linear programming approach. The multi-objective optimization model developed from this study is characterized by integrating eco-system service theory into water-saving measures. For evaluation purposes, the model is used to construct an optimal allocation system for irrigation areas fed by the Tailan River (Xinjiang Province, China). The objective functions to be optimized are formulated based on these irrigation areas' economic, social, and ecological benefits. The optimal irrigation water allocation plans are made under different hydroclimate conditions (wet year, normal year, and dry year), with multiple sources of uncertainty represented. The modeling tool and results are valuable for advising decision making by the local water authority—and the agricultural community—especially on measures for coping with water scarcity (by incorporating uncertain factors associated with crop production planning).

  11. Study on source apportionment of Non-Methane Hydrocarbon Compounds (NMHC) in Dagang Oil Field

    SciTech Connect

    Zhu Tan; Lin Tao; Bai Zhipeng

    1996-12-31

    To identify the sources of non-methane total hydrocarbon in atmosphere in the region of Dagang Oil Field, 35 samples were collected and 10 hydrocarbon compounds were analyzed with GC/FID. Then, the Chemical Mass Balance Receptor Model was set up and the source contributions and standard errors were determined with the effective variance weighted least squares estimation method. The sources of the non-methane total hydrocarbon in this region includes crude oil, gasoline, natural gas, liquefied petroleum gas and motor exhaust, whose contributions are 46.64%, 8.56%, 20.05%, 18.17% and 6.08% respectively. Upon these analyses, the major sources of regional non-methane total hydrocarbon are crude oil, natural gas and liquefied petroleum gas.

  12. Source Rock (shales) Pore Space Transformation during Hydrocarbon Generation

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.; Sudin, V. V.

    2015-12-01

    The main objective of this investigations is to study the factors controlling changes in rock structure during catagenetic transformation of organic matter. Hydrocarbon generation and primary migration can be controlled by numerous parameters; the most important are temperature, pressure, hydrocarbon composition, and organic matter type and content. Several experimental studies focused on the influence of these main parameters. However few dedicated works investigated how the primary structure characteristic and organic matter content affects the pore space transformation of rocks. For this purpose we simulated the primary migration processes in laboratory conditions (pyrolises and CT scanning) in order to observe the dynamics of pore space transformation. Our experiments demonstrate that after each stage of heating the rocks change their original morphology with the formation of new pores and conduits connecting the primary voids. The samples with relatively low content in organic matter revealed fewer changes in pore space morphology, in contrast to rocks rich in organic content. Our results also highlight that the newly formed pore structures are directly related with the original structure of the unaltered rocks and the primary connectivity of the organics. Most of the structural changes were observed during the sequential heating between 260 - 430 ° C; within this interval also occur the most intense reactions for hydrocarbons formation.

  13. Optimization of NANOGrav's time allocation for maximum sensitivity to single sources

    SciTech Connect

    Christy, Brian; Anella, Ryan; Lommen, Andrea; Camuccio, Richard; Handzo, Emma; Finn, Lee Samuel

    2014-10-20

    Pulsar timing arrays (PTAs) are a collection of precisely timed millisecond pulsars (MSPs) that can search for gravitational waves (GWs) in the nanohertz frequency range by observing characteristic signatures in the timing residuals. The sensitivity of a PTA depends on the direction of the propagating GW source, the timing accuracy of the pulsars, and the allocation of the available observing time. The goal of this paper is to determine the optimal time allocation strategy among the MSPs in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for a single source of GW under a particular set of assumptions. We consider both an isotropic distribution of sources across the sky and a specific source in the Virgo cluster. This work improves on previous efforts by modeling the effect of intrinsic spin noise for each pulsar. We find that, in general, the array is optimized by maximizing time spent on the best-timed pulsars, with sensitivity improvements typically ranging from a factor of 1.5 to 4.

  14. [The evaluation of hydrocarbon potential generation for source rocks by near-infrared diffuse reflection spectra].

    PubMed

    Zhang, Yu-Jia; Xu, Xiao-Xuan; Song, Ning; Wu, Zhong-Chen; Zhou, Xiang; Chen, Jin; Cao, Xue-Wei; Wang, Bin

    2011-04-01

    Near-infrared (NIR) and mid-infrared (MIR) diffuse reflection spectra were compared and evaluated for hydrocarbon potential generation of source rocks. Near-infrared diffuse reflectance often exhibits significant differences in the spectra due to the non-homogeneous distribution of the particles, so the signal-to-noise ratio of NIR is much lower than MIR It is too difficult to get accurate results by NIR without using a strong spectral preprocessing method to remove systematic noise such as base-line variation and multiplicative scatter effects. In the present paper, orthogonal signal correction (OSC) and an improved algorithm of it, i.e. direct orthogonal signal correction (DOSC), are used as different methods to preprocess both the NIR and MIR spectra of the hydrocarbon source rocks. Another algorithm, wavelet multi-scale direct orthogonal signal correction (WMDOSC), which is a combination of discrete wavelet transform (DWT) and DOSC, is also used as a preprocessing method. Then, the calibration model of hydrocarbon source rocks before and after pretreatment was established by interval partial least square (iPLS). The experimental results show that WMDOSC is more successfully applied to preprocess the NIR spectra data of the hydrocarbon source rocks than other two algorithms, and NIR performed as good as MIR in the analysis of hydrocarbon potential generation of source rocks with WMDOSC-iPLS pretreatment calibration model.

  15. One century of air deposition of hydrocarbons recorded in travertine in North Tibetan Plateau, China: Sources and evolution.

    PubMed

    Yuan, Guo-Li; Wu, Ming-Zhe; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

    2016-08-01

    The characteristic distribution patterns of hydrocarbons have been used for fingerprinting to identify their sources. The historical air depositions of hydrocarbons recorded in natural media help to understand the evolution of the air environment. Travertine is a natural acceptor of air deposition that settles on the ground layer by layer. To reconstruct the historical air environment of hydrocarbons in the North Tibetan Plateau (NTP), a unique background region, twenty-seven travertine samples were collected systematically from a travertine column according to its precipitated year. For each sample, the precipitated year was dated while n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were determined. Based on source identification, the air environment of hydrocarbons in the past century was studied for the region of NTP. Before World War II, the anthropogenic sources of hydrocarbons showed little influence on the air environment. During World War II and China's War of Liberation, hydrocarbons increased significantly, mainly from the use of fossil fuels. Between 1954 and 1963, hydrocarbons in the air decreased significantly because the sources of petroleum combustion decreased. From the mid-1960s through the end of the 1990s, air hydrocarbons, which mainly originated from biomass burning, increased gradually because agriculture and animal husbandry were developing steadily in Tibet and China. From the late 1990s, hydrocarbons in the atmosphere increased rapidly due to the rapid increase of tourism activities, which might increase hydrocarbon emissions from traffic. The reconstruction of the historical air hydrocarbons in NTP clearly reflects the evolution of the region and global development.

  16. Spatial, temporal, and source variations of hydrocarbons in marine sediments from Baffin Bay, Eastern Canadian Arctic.

    PubMed

    Foster, Karen L; Stern, Gary A; Carrie, Jesse; Bailey, Joscelyn N-L; Outridge, Peter M; Sanei, Hamed; Macdonald, Robie W

    2015-02-15

    With declining sea ice conditions in Arctic regions owing to changing climate, the large prospective reservoirs of oil and gas in Baffin Bay and Davis Strait are increasingly accessible, and the interest in offshore exploration and shipping through these regions has increased. Both of these activities are associated with the risk of hydrocarbon releases into the marine ecosystem. However, hydrocarbons are also present naturally in marine environments, in some cases deriving from oil seeps. We have analyzed hydrocarbon concentrations in eleven sediment cores collected from northern Baffin Bay during 2008 and 2009 Amundsen expeditions and have examined the hydrocarbon compositions in both pre- and post-industrial periods (i.e., before and after 1900) to assess the sources of hydrocarbons, and their temporal and spatial variabilities. Concentrations of ΣPAHs ranged from 341 to 2693 ng g(-1) dw, with concentrations in cores from sites within the North Water (NOW) Polynya generally higher. Individual PAH concentrations did not exceed concentrations of concern for marine aquatic life, with one exception found in a core collected within the NOW (one of the seven sediment core samples). Hydrocarbon biomarkers, including alkane profiles, OEP (odd-to-even preference), and TAR (terrigenous/aquatic ratios) values indicated that organic carbon at all sites is derived from both terrigenous higher plants and marine algae, the former being of greater significance at coastal sites, and the latter at the deepest sites at the southern boundary of the NOW. Biomarker ratios and chemical profiles indicate that petrogenic sources dominate over combustion sources, and thus long-range atmospheric transport is less significant than inputs from weathering. Present-day and historic pre-1900 hydrocarbon concentrations exhibited less than an order of magnitude difference for most compounds at all sites. The dataset presented here provides a baseline record of hydrocarbon concentrations in

  17. Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments from the Neuquen River, Argentine Patagonia.

    PubMed

    Monza, Liliana B; Loewy, Ruth M; Savini, Mónica C; Pechen de d'Angelo, Ana M

    2013-01-01

    Spatial distribution and probable sources of aliphatic and polyaromatic hydrocarbons (AHs, PAHs) were investigated in surface sediments collected along the bank of the Neuquen River, Argentina. Total concentrations of aliphatic hydrocarbons ranged between 0.41 and 125 μg/g dw. Six stations presented low values of resolved aliphatic hydrocarbons and the n-alkane distribution indexes applied suggested a clear biogenic source. These values can be considered the baseline levels of aliphatic hydrocarbons for the river sediments. This constitutes important information for the assessment of future impacts since a strong impulse in the exploitation of shale gas and shale oil in these zones is nowadays undergoing. For the other 11 stations, a mixture of aliphatic hydrocarbons of petrogenic and biogenic origin was observed. The spatial distribution reflects local inputs of these pollutants with a significant increase in concentrations in the lower course, where two major cities are located. The highest values of total aliphatic hydrocarbons were found in this sector which, in turn, was the only one where individual PAHs were detected.

  18. Sources of hydrocarbons in urban road dust: Identification, quantification and prediction.

    PubMed

    Mummullage, Sandya; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

    2016-09-01

    Among urban stormwater pollutants, hydrocarbons are a significant environmental concern due to their toxicity and relatively stable chemical structure. This study focused on the identification of hydrocarbon contributing sources to urban road dust and approaches for the quantification of pollutant loads to enhance the design of source control measures. The study confirmed the validity of the use of mathematical techniques of principal component analysis (PCA) and hierarchical cluster analysis (HCA) for source identification and principal component analysis/absolute principal component scores (PCA/APCS) receptor model for pollutant load quantification. Study outcomes identified non-combusted lubrication oils, non-combusted diesel fuels and tyre and asphalt wear as the three most critical urban hydrocarbon sources. The site specific variabilities of contributions from sources were replicated using three mathematical models. The models employed predictor variables of daily traffic volume (DTV), road surface texture depth (TD), slope of the road section (SLP), effective population (EPOP) and effective impervious fraction (EIF), which can be considered as the five governing parameters of pollutant generation, deposition and redistribution. Models were developed such that they can be applicable in determining hydrocarbon contributions from urban sites enabling effective design of source control measures.

  19. Using integrated noble gas and hydrocarbon geochemistry to constrain the source of hydrocarbon gases in shallow aquifers in the northern Appalachian Basin

    EPA Pesticide Factsheets

    Rising demands for domestic energy sources, mandates for cleaner burning fuels for electricity generation, and the approach of peak global hydrocarbon production are driving the transformation from coal to natural gas from unconventional energy resources.

  20. Characterization of Biosurfactant Produced during Degradation of Hydrocarbons Using Crude Oil As Sole Source of Carbon

    PubMed Central

    Patowary, Kaustuvmani; Patowary, Rupshikha; Kalita, Mohan C.; Deka, Suresh

    2017-01-01

    Production and spillage of petroleum hydrocarbons which is the most versatile energy resource causes disastrous environmental pollution. Elevated oil degrading performance from microorganisms is demanded for successful microbial remediation of those toxic pollutants. The employment of biosurfactant-producing and hydrocarbon-utilizing microbes enhances the effectiveness of bioremediation as biosurfactant plays a key role by making hydrocarbons bio-available for degradation. The present study aimed the isolation of a potent biosurfactant producing indigenous bacteria which can be employed for crude oil remediation, along with the characterization of the biosurfactant produced during crude oil biodegradation. A potent bacterial strain Pseudomonas aeruginosa PG1 (identified by 16s rDNA sequencing) was isolated from hydrocarbon contaminated soil that could efficiently produce biosurfactant by utilizing crude oil components as the carbon source, thereby leading to the enhanced degradation of the petroleum hydrocarbons. Strain PG1 could degrade 81.8% of total petroleum hydrocarbons (TPH) after 5 weeks of culture when grown in mineral salt media (MSM) supplemented with 2% (v/v) crude oil as the sole carbon source. GCMS analysis of the treated crude oil samples revealed that P. aeruginosa PG1 could potentially degrade various hydrocarbon contents including various PAHs present in the crude oil. Biosurfactant produced by strain PG1 in the course of crude oil degradation, promotes the reduction of surface tension (ST) of the culture medium from 51.8 to 29.6 mN m−1, with the critical micelle concentration (CMC) of 56 mg L−1. FTIR, LC-MS, and SEM-EDS studies revealed that the biosurfactant is a rhamnolipid comprising of both mono and di rhamnolipid congeners. The biosurfactant did not exhibit any cytotoxic effect to mouse L292 fibroblastic cell line, however, strong antibiotic activity against some pathogenic bacteria and fungus was observed. PMID:28275373

  1. Characterization of Biosurfactant Produced during Degradation of Hydrocarbons Using Crude Oil As Sole Source of Carbon.

    PubMed

    Patowary, Kaustuvmani; Patowary, Rupshikha; Kalita, Mohan C; Deka, Suresh

    2017-01-01

    Production and spillage of petroleum hydrocarbons which is the most versatile energy resource causes disastrous environmental pollution. Elevated oil degrading performance from microorganisms is demanded for successful microbial remediation of those toxic pollutants. The employment of biosurfactant-producing and hydrocarbon-utilizing microbes enhances the effectiveness of bioremediation as biosurfactant plays a key role by making hydrocarbons bio-available for degradation. The present study aimed the isolation of a potent biosurfactant producing indigenous bacteria which can be employed for crude oil remediation, along with the characterization of the biosurfactant produced during crude oil biodegradation. A potent bacterial strain Pseudomonas aeruginosa PG1 (identified by 16s rDNA sequencing) was isolated from hydrocarbon contaminated soil that could efficiently produce biosurfactant by utilizing crude oil components as the carbon source, thereby leading to the enhanced degradation of the petroleum hydrocarbons. Strain PG1 could degrade 81.8% of total petroleum hydrocarbons (TPH) after 5 weeks of culture when grown in mineral salt media (MSM) supplemented with 2% (v/v) crude oil as the sole carbon source. GCMS analysis of the treated crude oil samples revealed that P. aeruginosa PG1 could potentially degrade various hydrocarbon contents including various PAHs present in the crude oil. Biosurfactant produced by strain PG1 in the course of crude oil degradation, promotes the reduction of surface tension (ST) of the culture medium from 51.8 to 29.6 mN m(-1), with the critical micelle concentration (CMC) of 56 mg L(-1). FTIR, LC-MS, and SEM-EDS studies revealed that the biosurfactant is a rhamnolipid comprising of both mono and di rhamnolipid congeners. The biosurfactant did not exhibit any cytotoxic effect to mouse L292 fibroblastic cell line, however, strong antibiotic activity against some pathogenic bacteria and fungus was observed.

  2. Hydrocarbon status of soils under atmospheric pollution from a local industrial source

    NASA Astrophysics Data System (ADS)

    Gennadiev, A. N.; Zhidkin, A. P.; Pikovskii, Yu. I.; Kovach, R. G.; Koshovskii, T. S.; Khlynina, N. I.

    2016-09-01

    Contents and compositions of bitumoids, polycyclic aromatic hydrocarbons (PAHs), and free and retained hydrocarbon gases in soils along a transect at different distances from the local industrial source of atmospheric pollution with soot emissions have been studied. The reserves of PAHs progressively decrease when the distance from the source increases. Among the individual PAHs, the most significant decrease is observed for benzo[ a]pyrene, tetraphene, pyrene, chrysene, and anthracene. On plowlands, the share of heavy PAHs—benzo[ ghi]perylene, benzo[ a]pyrene, perylene, etc.—is lower than in the forest soils. In automorphic soils of the park zone adjacent to the industrial zone, the penetration depth of four-, five-, and sixring PAHs from the atmosphere is no more than 25 cm. In soils under natural forest vegetation, heavy PAHs do not penetrate deeper than 5 cm; in tilled soils, their penetration depth coincides with the lower boundary of plow horizons. Analysis of free gases in the soil air revealed hydrocarbons only under forest. From the quantitative and qualitative parameters of the content, reserves, and compositions of different hydrocarbons, the following modification types of hydrocarbon status in the studied soils were revealed: injection, atmosedimentation-injection, atmosedimentation-impact, atmosedimentation-distant, and biogeochemical types.

  3. Analyzing hydrocarbons in sewer to help in PAH source apportionment in sewage sludges.

    PubMed

    Mansuy-Huault, Laurence; Regier, Annette; Faure, Pierre

    2009-05-01

    A multi-molecular approach for polycyclic aromatic hydrocarbons (PAH) source apportionment in sewage sludge was tested. Three simple catchment areas with corresponding wastewater treatment plants (WWTP) were chosen. Sewage sludges of these WWTPs chronically exceeded the French guide values for PAHs. Aliphatic and aromatic hydrocarbons were quantified in sediments or wastewater suspended particulate matter sampled in different locations of the sewer as well as in sewage sludge. Various molecular indices including PAH ratios were calculated. The results showed that the ratios calculated from sewage sludge analyses provided a rather unspecific hydrocarbon fingerprint where combustion input appear as the main PAH sources. The complexity of the inputs as well as degradation occurring during wastewater treatment prevent any detailed diagnosis. Coupled to the analyses of samples collected in the sewer, the multi-molecular approach becomes more efficient especially for the identification of specific petroleum inputs such as fuel or used lubricating oils which can be important PAH sources. Indeed, the sampling in the sewer allows a spatial screening of the hydrocarbon inputs and facilitates the PAH source apportionment by avoiding the dilution of specific inputs with the whole wastewater inputs and by limiting the degradation of the molecular fingerprint that could occur during transfer and treatment in the WWTP. Then, the combination of PAH ratios and aliphatic distribution analyses is a very valuable approach that can help in sewer and WWTP management.

  4. Hydrocarbon potential of hydrocarbon source rocks of the New Siberian Islands, Russian Arctic

    NASA Astrophysics Data System (ADS)

    Gaedicke, Christoph; Sobolev, Peter; Franke, Dieter; Piepjohn, Karsten; Brandes, Christian; Kus, Jolanta; Scheeder, Georg

    2016-04-01

    The New Siberian Islands are bridging the Laptev Sea with the East Siberian Sea. The Laptev and East Siberian Seas cover large areas of the continental margin of northeastern Arctic Russia. The East Siberian Shelf encompassing an area of 935.000 km2 is still virtually unexplored and most of the geological models for this shelf are extrapolations of the geology of the New Siberian Islands, the Wrangel Island and the northeast Siberian landmass. Apart from few seismic reflection lines, airborne magnetic data were the primary means of deciphering the structural pattern of the East Siberian Shelf. The Laptev Shelf covers an area of about 66.000 km2 and occupies a shelf region, where the active mid-oceanic spreading ridge of the Eurasian Basin hits the slope of the continental margin. During the joint VSEGEI/BGR field expedition CASE 13 (Circum Arctic Structural Events) in summer 2011 we sampled outcrops from the New Siberian Archipelago including the De Long Islands. 102 samples were collected and the Upper Palaeozoic to Lower Cenozoic units are found to be punctuated by several organic-rich intervals. Lithology varies from continental dominated clastic sedimentary rocks with coal seams to shallow marine carbonates and deep marine black shales. Rock-Eval pyrolysis, gas chromatography/mass spectrometry and organic petrography studies were performed to estimate organic matter contents, composition, source, and thermal maturity. According to the results of our analyses, samples from several intervals may be regarded as potential petroleum source rocks. The Lower Devonian shales have the highest source rock potential of all Paleozoic units. Triassic samples have a good natural gas potential. Cretaceous and Cenozoic low-rank coals, lignites, and coal-bearing sandstones display some gas potential. The kerogen of type III (humic, gas-prone) dominates. Most of the samples (except some of Cretaceous and Paleogene age) reached the oil generation window.

  5. Using Geophysical Signatures to Investigate Temporal Changes Due to Source Reduction in the Subsurface Contaminated with Hydrocarbons

    EPA Science Inventory

    We investigated the geophysical response to subsurface hydrocarbon contamination source removal. Source removal by natural attenuation or by engineered bioremediation is expected to change the biological, chemical, and physical environment associated with the contaminated matrix....

  6. Distribution and Sources of Petroleum Hydrocarbons in Recent Sediments of the Imo River, SE Nigeria.

    PubMed

    Oyo-Ita, Inyang O; Oyo-Ita, Orok E; Dosunmu, Miranda I; Domínguez, Carmen; Bayona, Josep M; Albaigés, Joan

    2016-02-01

    The distribution of aliphatic and aromatic hydrocarbons in surface sediments of the lower course of the Imo River (Nigeria) was investigated to determine the sources and fate of these compounds. The aliphatic fraction is characterized by a widespread contribution of highly weathered/biodegraded hydrocarbon residues (reflected in the absence of prominent n-alkane peaks coupled with the presence of 17α(H),21β(H)-25-norhopane, an indicator of heavy hydrocarbon biodegradation) of Nigerian crude oils (confirmed by the occurrence of 18α(H)-oleanane, a compound characteristic of oils of deltaic origin). The concentrations of polycyclic aromatic hydrocarbons (PAHs) ranging from 48 to 117 ng/g dry weight (dw; ∑13PAHs) indicate a moderate pollution, possibly lowered by the sandy lithology and low organic carbon (OC) content of the sediments. Concentrations slightly decrease towards the estuary of the river, probably due to the fact that these stations are affected by tidal flushing of pollutants adsorbed on sediment particles and carried away by occasional storm to the Atlantic Ocean. A number of PAH ratios, including parent/alkylated and isomeric compounds, indicates a predominance of petrogenic sources, with a low contribution of pyrolytic inputs, particularly of fossil fuel combustion. On the basis of OC/ON (>10) and Per/ΣPAHpenta- (>10) values, a diagenetic terrigenous OC was proposed as a source of perylene to the river.

  7. The use of exposure source allocation factor in the risk assessment of drinking-water contaminants.

    PubMed

    Krishnan, Kannan; Carrier, Richard

    2013-01-01

    In the risk assessment process, the reference dose, tolerable intake, or acceptable daily intake (RfD, TDI, ADI) is apportioned to specific exposure sources on the basis of a source allocation factor (AF) or relative source contribution (RSC). The U.S. Environmental Protection Agency (EPA) published an exposure decision tree framework in 2000 to guide the determination of AF (or RSC) of drinking-water contaminants (DWC). Besides that, there has not been any systematic analysis of the basis of the use of AF in DWC risk assessments. This article therefore critically reviews and integrates current knowledge and approaches for the development of AF, while focusing on its consistent use in DWC risk assessments based on consideration of (i) risk assessment endpoint, (ii) existing guidelines, (iii) exposure estimates, (iv) usage pattern and environmental fate information, (v) physicochemical properties, (vi) bounds of AF, (vii) multiroute exposures, and (viii) target population characteristics. Accordingly, for a DWC for which drinking water is not a major source of exposure and for which there is documented evidence of widespread presence in one or more of the other media (i.e., air, food, soil, or consumer products), the use of an AF value of 0.2 is suggested. For DWC for which drinking water represents nearly the single major source of exposure, a ceiling AF value of 0.8 is suggested. For other situations, chemical- and context-specific AF values can be developed based on exposure data or models, which should in turn be bounded by the floor and ceiling AF values as originally described by the U.S. EPA (i.e., 0.2-0.8). Future studies need to focus on improvements in methods for deriving AF, by basing it on the consideration of bioavailability, target tissue dose, and extent of route-specific absorption, as well as improvement in the modeling of dose received via direct/voluntary exposure through consumer products and at workplaces.

  8. Bioaccumulation of hydrocarbons derived from terrestrial and anthropogenic sources in the Asian clam, Potamocorbula amurensis, in San Francisco Bay estuary

    USGS Publications Warehouse

    Pereira, Wilfred E.; Hostettler, Frances D.; Rapp, John B.

    1992-01-01

    An assessment was made in Suisun Bay, California, of the distributions of hydrocarbons in estuarine bed and suspended sediments and in the recently introduced asian clam, Potamocorbula amurensis. Sediments and clams were contaminated with hydrocarbons derived from petrogenic and pyrogenic sources. Distributions of alkanes and of hopane and sterane biomarkers in sediments and clams were similar, indicating that petroleum hydrocarbons associated with sediments are bioavailable to Potamocorbula amurensis. Polycyclic aromatic hydrocarbons in the sediments and clams were derived mainly from combustion sources. Potamocorbula amurensis is therefore a useful bioindicator of hydrocarbon contamination, and may be used as a biomonitor of hydrocarbon pollution in San Francisco Bay.

  9. Forensic source differentiation of petrogenic, pyrogenic, and biogenic hydrocarbons in Canadian oil sands environmental samples.

    PubMed

    Wang, Zhendi; Yang, C; Parrott, J L; Frank, R A; Yang, Z; Brown, C E; Hollebone, B P; Landriault, M; Fieldhouse, B; Liu, Y; Zhang, G; Hewitt, L M

    2014-04-30

    To facilitate monitoring efforts, a forensic chemical fingerprinting methodology has been applied to characterize and differentiate pyrogenic (combustion derived) and biogenic (organism derived) hydrocarbons from petrogenic (petroleum derived) hydrocarbons in environmental samples from the Canadian oil sands region. Between 2009 and 2012, hundreds of oil sands environmental samples including water (snowmelt water, river water, and tailings pond water) and sediments (from river beds and tailings ponds) have been analyzed. These samples were taken from sites where assessments of wild fish health, invertebrate communities, toxicology and detailed chemistry are being conducted as part of the Canada-Alberta Joint Oil Sands Monitoring Plan (JOSMP). This study describes the distribution patterns and potential sources of PAHs from these integrated JOSMP study sites, and findings will be linked to responses in laboratory bioassays and in wild organisms collected from these same sites. It was determined that hydrocarbons in Athabasca River sediments and waters were most likely from four sources: (1) petrogenic heavy oil sands bitumen; (2) biogenic compounds; (3) petrogenic hydrocarbons of other lighter fuel oils; and (4) pyrogenic PAHs. PAHs and biomarkers detected in snowmelt water samples collected near mining operations imply that these materials are derived from oil sands particulates (from open pit mines, stacks and coke piles).

  10. Environmental forensics evaluation of sources of sediment hydrocarbon contamination in Milford Haven Waterway.

    PubMed

    Little, David I; Galperin, Yakov; Bullimore, Blaise; Camplin, Mike

    2015-02-01

    Current and historic petroleum-related activities in Milford Haven Waterway (MHW; Wales, UK) contribute to hydrocarbon contamination of surficial sediments. Three main hydrocarbon components of sediments were analyzed: (1) aliphatic hydrocarbons of predominantly biogenic origin, representing about 5-15% of total hydrocarbons (THC); (2) polycyclic aromatic hydrocarbons (PAHs) from recent petrogenic and mainly older pyrogenic sources, representing about 2-6% of THC; (3) unresolved complex mixture from spill-related and heavily-weathered petrogenic sources, representing as much as 70-85% of THC. Environmental forensics evaluation of the data demonstrate that although 72,000 tonnes (t) crude oil spilled from the Sea Empress in 1996, the Forties blend cargo was not identified in 2010. However, using biomarkers, heavy fuel oil (HFO) from Sea Empress' bunkers (480 t spilled) was detected further upstream and more widely than previously. Iranian crude (100 t) spilled by the El Omar in 1988 and fuel (130,000 t) lost during bombing in 1940 also were tentatively identified. The PAH source ratios demonstrate that the historic pyrogenic PAHs come mainly from biomass and coal combustion. The distribution pattern of PAHs appeared more pyrogenic in 2012 than in 1996, as if recovering from the more petrogenic signature, in places, of the Sea Empress. The heavier PAH distributions were pyrogenic at most stations, and similar to those in sediments from oil terminal berths up to 2006, when dredging operations peaked. Partly as a result of this, in 2007 the concentrations of PAHs peaked throughout the waterway. Apart from effluent, atmospheric and runoff inputs, most of the identified inputs to the surficial sediments are historic. Therefore, likely processes include disturbance by construction (e.g. pile-driving) and dredging of contaminants sequestered in sediments, followed by their wide redistribution via suspended sediment transport.

  11. Joint source-channel rate allocation and client clustering for scalable multistream IPTV.

    PubMed

    Chakareski, Jacob

    2015-08-01

    We design a system framework for streaming scalable internet protocol television (IPTV) content to heterogenous clients. The backbone bandwidth is optimally allocated between source and parity data layers that are delivered to the client population. The assignment of stream layers to clients is done based on their access link data rate and packet loss characteristics, and is part of the optimization. We design three techniques for jointly computing the optimal number of multicast sessions, their respective source and parity rates, and client membership, either exactly or approximatively, at lower complexity. The latter is achieved via an iterative coordinate descent algorithm that only marginally underperforms relative to the exact analytic solution. Through experiments, we study the advantages of our framework over common IPTV systems that deliver the same source and parity streams to every client. We observe substantial gains in video quality in terms of both its average value and standard deviation over the client population. In addition, for energy efficiency, we propose to move the parity data generation part to the edge of the backbone network, where each client connects to its IPTV stream. We analytically study the conditions under which such an approach delivers energy savings relative to the conventional case of source and parity data generation at the IPTV streaming server. Finally, we demonstrate that our system enables more consistent streaming performance, when the clients' access link packet loss distribution is varied, relative to the two baseline methods used in our investigation, and maintains the same performance as an ideal system that serves each client independently.

  12. Assessment of hydrocarbon source rock potential of Polish bituminous coals and carbonaceous shales

    USGS Publications Warehouse

    Kotarba, M.J.; Clayton, J.L.; Rice, D.D.; Wagner, M.

    2002-01-01

    We analyzed 40 coal samples and 45 carbonaceous shale samples of varying thermal maturity (vitrinite reflectance 0.59% to 4.28%) from the Upper Carboniferous coal-bearing strata of the Upper Silesian, Lower Silesian, and Lublin basins, Poland, to evaluate their potential for generation and expulsion of gaseous and liquid hydrocarbons. We evaluated source rock potential based on Rock-Eval pyrolysis yield, elemental composition (atomic H/C and O/C), and solvent extraction yields of bitumen. An attempt was made to relate maceral composition to these source rock parameters and to composition of the organic matter and likely biological precursors. A few carbonaceous shale samples contain sufficient generation potential (pyrolysis assay and elemental composition) to be considered potential source rocks, although the extractable hydrocarbon and bitumen yields are lower than those reported in previous studies for effective Type III source rocks. Most samples analysed contain insufficient capacity for generation of hydrocarbons to reach thresholds required for expulsion (primary migration) to occur. In view of these findings, it is improbable that any of the coals or carbonaceous shales at the sites sampled in our study would be capable of expelling commercial amounts of oil. Inasmuch as a few samples contained sufficient generation capacity to be considered potential source rocks, it is possible that some locations or stratigraphic zones within the coals and shales could have favourable potential, but could not be clearly delimited with the number of samples analysed in our study. Because of their high heteroatomic content and high amount of asphaltenes, the bitumens contained in the coals are less capable of generating hydrocarbons even under optimal thermal conditions than their counterpart bitumens in the shales which have a lower heteroatomic content. Published by Elsevier Science B.V.

  13. Novel techniques for characterization of hydrocarbon emission sources in the Barnett Shale

    NASA Astrophysics Data System (ADS)

    Nathan, Brian Joseph

    Changes in ambient atmospheric hydrocarbon concentrations can have both short-term and long-term effects on the atmosphere and on human health. Thus, accurate characterization of emissions sources is critically important. The recent boom in shale gas production has led to an increase in hydrocarbon emissions from associated processes, though the exact extent is uncertain. As an original quantification technique, a model airplane equipped with a specially-designed, open-path methane sensor was flown multiple times over a natural gas compressor station in the Barnett Shale in October 2013. A linear optimization was introduced to a standard Gaussian plume model in an effort to determine the most probable emission rate coming from the station. This is shown to be a suitable approach given an ideal source with a single, central plume. Separately, an analysis was performed to characterize the nonmethane hydrocarbons in the Barnett during the same period. Starting with ambient hourly concentration measurements of forty-six hydrocarbon species, Lagrangian air parcel trajectories were implemented in a meteorological model to extend the resolution of these measurements and achieve domain-fillings of the region for the period of interest. A self-organizing map (a type of unsupervised classification) was then utilized to reduce the dimensionality of the total multivariate set of grids into characteristic one-dimensional signatures. By also introducing a self-organizing map classification of the contemporary wind measurements, the spatial hydrocarbon characterizations are analyzed for periods with similar wind conditions. The accuracy of the classification is verified through assessment of observed spatial mixing ratio enhancements of key species, through site-comparisons with a related long-term study, and through a random forest analysis (an ensemble learning method of supervised classification) to determine the most important species for defining key classes. The hydrocarbon

  14. Sources, fates, and effects of aromatic hydrocarbons in the Alaskan marine environment with recommendations for monitoring strategies

    SciTech Connect

    Anderson, J.W.; Neff, J.M.; Boehm, P.D.

    1986-03-01

    Information about polycyclic aromatic hydrocarbons in the Alaskan marine environment is relatively sparse. About 300 references were reviewed to create an assessment of the current state of knowledge on sources, fates and effects of oil-derived polycyclic aromatic hydrocarbons in cold marine waters. The objective of the report is to critically review what is known about the sources, fates and effects of polycyclic aromatic hydrocarbons (PAH) in the Alaskan marine environment. The specific areas reviewed are (1) the natural and anthropogenic sources of aromatic hydrocarbons in the Alaskan marine environment, (2) the physical, chemical and biochemical fates of these compounds in marine ecosystems, and (3) the bioaccumulation and biological effects of aromatic hydrocarbons in marine organisms.

  15. Source apportionment of sediment-associated aliphatic hydrocarbon in a eutrophicated shallow lake, China.

    PubMed

    Wang, Ji-Zhong; Yang, Ze-Yu; Chen, Tian-Hu

    2012-11-01

    Chaohu Lake, one of the most eutrophicated lakes in China, has been suffering from long-term outside pollution, urban sewage, river outflows, and agricultural runoff which expectedly have been the main contributors of hydrocarbons. However, the contributions from these various sources have not been specified. The present study is aimed at identifying the potential sources of hydrocarbons in surface sediment around the whole lake and assessing the relative contributions using principal components analysis-multiple linear regression (PCA-MLR). Sixty-one surface sediments covering the whole Chaohu Lake and three main estuaries of inflowing rivers were collected, dried, extracted, and analyzed for 27 normal alkanes (n-alkanes, from C(12) to C(38), defined Σ(27)AH) and unresolved complex mixture (UCM) by GC/MS. Diagnostic ratios and PCA-MLR were utilized to apportion their sources. The concentrations of Σ(27)AH and UCM ranged from 434 to 3,870 ng/g and 11.9 to 325 μg/g dry weight, respectively, for all samples. The concentrations of Σ(27)AH in western region and estuary of Nanfei River were slightly higher but without statistical significance than those from eastern region and estuaries of Yuxi River and Hangbu River. The concentration of UCM from western region was significantly higher than that obtained from eastern region. These results reflect the importance of input of urban runoff by Nanfei River and serious eutrophication in western region. Aliphatic hydrocarbons in Chaohu Lake were mainly derived from high plant wax with mixed sources of phytoplankton and petroleum. Weak microbial decomposition of n-alkanes would be expected to occur from the low ratios of isoprenoid hydrocarbons pristine (pri) and phytane (phy) to n-C(17) and n-C(18), respectively. Higher plant, fossil combustion, petroleum residue, and phytoplankton were proposed as the main origines of aliphatic hydrocarbons by PCA while the contributions of individual n-alkane homologues, pri and phy

  16. Hydrocarbon Source Rocks in the Deep River and Dan River Triassic Basins, North Carolina

    USGS Publications Warehouse

    Reid, Jeffrey C.; Milici, Robert C.

    2008-01-01

    This report presents an interpretation of the hydrocarbon source rock potential of the Triassic sedimentary rocks of the Deep River and Dan River basins, North Carolina, based on previously unpublished organic geochemistry data. The organic geochemical data, 87 samples from 28 drill holes, are from the Sanford sub-basin (Cumnock Formation) of the Deep River basin, and from the Dan River basin (Cow Branch Formation). The available organic geochemical data are biased, however, because many of the samples collected for analyses by industry were from drill holes that contained intrusive diabase dikes, sills, and sheets of early Mesozoic age. These intrusive rocks heated and metamorphosed the surrounding sediments and organic matter in the black shale and coal bed source rocks and, thus, masked the source rock potential that they would have had in an unaltered state. In places, heat from the intrusives generated over-mature vitrinite reflectance (%Ro) profiles and metamorphosed the coals to semi-anthracite, anthracite, and coke. The maximum burial depth of these coal beds is unknown, and depth of burial may also have contributed to elevated thermal maturation profiles. The organic geochemistry data show that potential source rocks exist in the Sanford sub-basin and Dan River basin and that the sediments are gas prone rather than oil prone, although both types of hydrocarbons were generated. Total organic carbon (TOC) data for 56 of the samples are greater than the conservative 1.4% TOC threshold necessary for hydrocarbon expulsion. Both the Cow Branch Formation (Dan River basin) and the Cumnock Formation (Deep River basin, Sanford sub-basin) contain potential source rocks for oil, but they are more likely to have yielded natural gas. The organic material in these formations was derived primarily from terrestrial Type III woody (coaly) material and secondarily from lacustrine Type I (algal) material. Both the thermal alteration index (TAI) and vitrinite reflectance data

  17. Hydrocarbon potential evaluation of the source rocks from the Abu Gabra Formation in the Sufyan Sag, Muglad Basin, Sudan

    NASA Astrophysics Data System (ADS)

    Qiao, Jinqi; Liu, Luofu; An, Fuli; Xiao, Fei; Wang, Ying; Wu, Kangjun; Zhao, Yuanyuan

    2016-06-01

    The Sufyan Sag is one of the low-exploration areas in the Muglad Basin (Sudan), and hydrocarbon potential evaluation of source rocks is the basis for its further exploration. The Abu Gabra Formation consisting of three members (AG3, AG2 and AG1 from bottom to top) was thought to be the main source rock formation, but detailed studies on its petroleum geology and geochemical characteristics are still insufficient. Through systematic analysis on distribution, organic matter abundance, organic matter type, organic matter maturity and characteristics of hydrocarbon generation and expulsion of the source rocks from the Abu Gabra Formation, the main source rock members were determined and the petroleum resource extent was estimated in the study area. The results show that dark mudstones are the thickest in the AG2 member while the thinnest in the AG1 member, and the thickness of the AG3 dark mudstone is not small either. The AG3 member have developed good-excellent source rock mainly with Type I kerogen. In the Southern Sub-sag, the AG3 source rock began to generate hydrocarbons in the middle period of Bentiu. In the early period of Darfur, it reached the hydrocarbon generation and expulsion peak. It is in late mature stage currently. The AG2 member developed good-excellent source rock mainly with Types II1 and I kerogen, and has lower organic matter abundance than the AG3 member. In the Southern Sub-sag, the AG2 source rock began to generate hydrocarbons in the late period of Bentiu. In the late period of Darfur, it reached the peak of hydrocarbon generation and its expulsion. It is in middle mature stage currently. The AG1 member developed fair-good source rock mainly with Types II and III kerogen. Throughout the geological evolution history, the AG1 source rock has no effective hydrocarbon generation or expulsion processes. Combined with basin modeling results, we have concluded that the AG3 and AG2 members are the main source rock layers and the Southern Sub-sag is

  18. A comparison of hydrocarbon gases from natural sources in the northwestern United States

    SciTech Connect

    Lorenson, T.D.; Kvenvolden, K.A. )

    1993-01-01

    The northwestern United States hosts a remarkable quantity and variety of thermal springs, seeps, and other natural-gas sources. Although many studies have dealt with the liquids and nonhydrocarbon gases emanating from these sources, few have focused on hydrocarbon gases. Of these gases, methane in particular is now recognized as an important reactive trace gas in the Earth's atmosphere that plays a significant role in global warming because of its greenhouse properties. To understand better the magnitude and occurrence of emissions of hydrocarbons from natural sources to the atmosphere, we have begun a survey of these gases throughout the northwestern United States. This area encompasses a number of different tectonic provinces: The Yellowstone hot spot, the northern Basin and Range Province, the Cascade volcanic arc, and the Cascadia subduction complex. Each province hosts springs and seeps with some unique compositions owing to the geological processes operating there. Methane is present in each area at concentration levels ranging from about 2 parts per million by volume (ppm-v) to 95.6 percent (by volume). Hydrothermal activity in the Yellowstone area produces spring gases containing less than 4 percent methane, with carbon dioxide as the balance gas. The Grand Teton National Park area, immediately to the south, has a wide variety of gas compositions with either methane, carbon dioxide, or nitrogen as the primary gas component. Where methane is abundant, higher molecular weight hydrocarbon gases (ethane, ethene, propane, propene, isobutane, and n-butane) are also found in ppm-v concentrations. In the northern Great Basin, thermal springs and seeps typically occur along fault zones at the base of mountain ranges. Methane concentrations range from 0.2 to 47 percent, with higher molecular weight hydrocarbon concentrations from 0 to 3,100 ppm-v. 47 refs., 8 figs., 4 tabs.

  19. Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment.

    PubMed

    Mishra, Nitika; Ayoko, Godwin A; Morawska, Lidia

    2016-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas.

  20. Hydrocarbons in intertidal sediments and mussels from Prince William Sound, Alaska, 1977-1980: Characterization and probable sources. Technical memo

    SciTech Connect

    Karinen, J.F.; Babcock, M.M.; Brown, D.W.; MacLeod, W.D.; Ramos, L.S.

    1993-01-01

    The oil spill that resulted from the March 1989 grounding of the oil tanker vessel Exxon Valdez provides a unique opportunity for the study of marine oil pollution effects because the spilled crude oil polluted a large geographic area that was previously considered pristine. The only sources of confounding hydrocarbons in the areas of Prince William Sound, Alaska, impacted by the spill are naturally occurring hydrocarbons and anthropogenic hydrocarbons from occasional boating activity in the Sound or due to long-range atmospheric transport. The authors' objectives were to determine the levels, intra-annual variability, and interannual variability of selected alkane hydrocarbons and PAHs in intertidal sediments and in M. trossulus tissues at a network of sampling stations over the 4-year sampling period, and if possible to identify the likely sources of hydrocarbons found.

  1. Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

    PubMed

    Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

    2014-01-01

    Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

  2. Polycyclic Aromatic Hydrocarbons in Coastal Sediment of Klang Strait, Malaysia: Distribution Pattern, Risk Assessment and Sources

    PubMed Central

    Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

    2014-01-01

    Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait. PMID:24747349

  3. The influence of metal source uncertainty on cost-effective allocation of mine water pollution abatement in catchments.

    PubMed

    Baresel, Christian; Destouni, Georgia; Gren, Ing-Marie

    2006-01-01

    In mine water pollution abatement, it is commonly assumed that known mine waste sites are the major pollution sources, thus neglecting the possibility of significant contribution from other old and diffuse sources within a catchment. We investigate the influence of different types of pollution source uncertainty on cost-effective allocation of abatement measures for mine water pollution. A catchment-scale cost-minimization model is developed and applied to the catchment of the river Dalälven, Sweden, in order to exemplify important effects of such source uncertainty. Results indicate that, if the pollution distribution between point and diffuse sources is partly unknown, downstream abatement measures, such as constructed wetlands, at given compliance boundaries are often cost-effective. If downstream abatement measures are not practically feasible, the pollution source distribution between point and diffuse mine water sources is critical for cost-effective solutions to abatement measure allocation in catchments. In contrast, cost-effective solutions are relatively insensitive to uncertainty in total pollutant discharge from mine water sources.

  4. Compilation of a source profile database for hydrocarbon and OVOC emissions in China

    NASA Astrophysics Data System (ADS)

    Mo, Ziwei; Shao, Min; Lu, Sihua

    2016-10-01

    Source profiles are essential for quantifying the role of volatile organic compound (VOC) emissions in air pollution. This study compiled a database of VOC source profiles in China, with 75 species drawn from five major categories: transportation, solvent use, biomass burning, fossil fuel burning, and industrial processes. Source profiles were updated for diesel vehicles, biomass burning, and residential coal burning by measuring both hydrocarbons and oxygenated VOCs (OVOCs), while other source profiles were derived from the available literature. The OVOCs contributed 53.8% of total VOCs in the profiles of heavy - duty diesel vehicle exhaust and 12.4%-46.3% in biomass and residential coal burning, which indicated the importance of primary OVOCs emissions from combustion-related sources. Taking the national emission inventory from 2008 as an example, we established an approach for assigning source profiles to develop a speciation-specific VOC and OVOC emission inventory. The results showed that aromatics contributed 30% of the total 26 Tg VOCs, followed by alkanes (24%), alkenes (19%) and OVOCs (12%). Aromatics (7.9 Tg) were much higher than in previous results (1.1 Tg and 3.4 Tg), while OVOCs (3.1 Tg) were comparable with the 3.3 Tg and 4.3 Tg reported in studies using profiles from the US. The current emission inventories were built based on emission factors from non-methane hydrocarbon measurements, and therefore the proportions from OVOC emissions was neglected, leading to up to 30% underestimation of total VOC emissions. As a result, there is a need to deploy appropriate emission factors and source profiles that include OVOC measurements to reduce the uncertainty of estimated emissions and chemical reactivity potential.

  5. Hydrocarbon source-rock evaluation - Solor Church Formation (middle Proterozoic, Keweenawan Supergroup), southeastern Minnesota

    USGS Publications Warehouse

    Hatch, J.R.; Morey, G.B.

    1984-01-01

    In the type section (Lonsdale 65-1 core, Rice County, Minnesota) the Solor Church Formation (Middle Proterozoic, Keweenawan Supergroup) consists primarily of reddish-brown mudstone and siltstone and pale reddish-brown sandstone. The sandstone and siltstone are texturally and mineralogically immature. Hydrocarbon source-rock evaluation of bluish-gray, greenish-gray and medium-dark-gray to grayish-black beds, which primarily occur in the lower 104 m (340 ft) of this core, shows: (1) the rocks have low organic carbon contents (<0.5 percent for 22 of 25 samples); (2) the organic matter is thermally very mature (Tmax = 494°C, sample 19) and is probably near the transition between the wet gas phase of catagenesis and metagenesis (dry gas zone); and (3) the rocks have minimal potential for producing additional hydrocarbons (genetic potential <0.30 mgHC/gm rock). Although no direct evidence exists from which to determine maximum depths of burial, the observed thermal maturity of the organic matter requires significantly greater depths of burial and(or) higher geothermal gradients. It is likely, at least on the St. Croix horst, that thermal alteration of the organic matter in the Solor Church took place relatively early, and that any hydrocarbons generated during this early thermal alteration were probably lost prior to deposition of the overlying Fond du Lac Formation (Middle Proterozoic, Keweenawan Supergroup).

  6. Determination of the Possible Source of Chlorinated Hydrocarbons Detected By SAM during MSL Mission

    NASA Astrophysics Data System (ADS)

    Buch, A.; Belmahdi, I.; Szopa, C.; Freissinet, C.; Glavin, D. P.; Francois, P.; Coll, P. J.; Miller, K.; Eigenbrode, J. L.; Stern, J. C.; Navarro-Gonzalez, R.; McAdam, A.; Teinturier, S.; Bonnet, J. Y.; Summons, R. E.; Millan, M.; Dequaire, T.; Cabane, M.; Mahaffy, P. R.

    2014-12-01

    The SAM GC-MS instrument on the Curiosity rover allows to analyze volatile compounds from the atmosphere or volatile compounds from the Martian regolith and refractory compounds in the regolith after sample treatment using wet chemistry. One portion of the wet chemistry experiment is composed of MTBSTFA (N-methyl-N-tert-butyldimethylsilyltrifluoroacetamide) / DMF (dimethylformamide). Abundant chlorinated hydrocarbons have been detected with SAM when analyzing samples collected in several sites explored by Curiosity rover. Some of these chlorohydrocarbons are produced during pyrolysis by the reaction of Martian oxychlorine compounds in the samples with terrestrial carbon from a derivatization agent (MTBSTFA) used in SAM (1, 2). Chlorobenzene cannot be formed by the direct reaction of MTBSTFA and DMF when heated in the presence of fused silica and perchlorates under SAM-like conditions (1)) therefore two other reaction pathways for chlorobenzene were proposed : (1) reactions between the volatile thermal degradation products of perchlorates (e.g. O2, Cl2 and HCl) and Tenax® and (2) the interaction of perchlorates with organic material from the martian regolith such as benzenecarboxylates (3, 4). This study investigates several propositions for chlorinated hydrocarbon formation by looking for: (1) all products coming from the interaction of Tenax® (which is part of the SAM hydrocarbon trap) and perchlorates, (2) also between some soil sample and perchlorates in the presence or absence of MTBSTFA and (c) sources of chlorinated hydrocarbon precursors. References: 1. D. P. Glavin et al.(2013) JGR 118, 1955-1973. 2. L. a Leshin et al. (2013) Science 341, 1238937. 3. C. Freissinet et al. (2014) LPSC XXXXV Abstract 2796. 4. D. Glavin et al. (2014) LPSC XXXV Abstract #1157.

  7. Parsing pyrogenic polycyclic aromatic hydrocarbons: forensic chemistry, receptor models, and source control policy.

    PubMed

    O'Reilly, Kirk T; Pietari, Jaana; Boehm, Paul D

    2014-04-01

    A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple-lines-of-evidence approach. Atmospheric receptor models, such as the US Environmental Protection Agency (USEPA)'s chemical mass balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in sediments. This paper describes the assumptions underlying receptor models and discusses challenges in complying with these assumptions in practice. Given the variability within, and the similarity among, pyrogenic PAH source types, model outputs are sensitive to specific inputs, and parsing among some source types may not be possible. Although still useful for identifying potential sources, the technical specialist applying these methods must describe both the results and their inherent uncertainties in a way that is understandable to nontechnical policy makers. The authors present an example case study concerning an investigation of a class of parking-lot sealers as a significant source of PAHs in urban sediment. Principal component analysis is used to evaluate published CMB model inputs and outputs. Targeted analyses of 2 areas where bans have been implemented are included. The results do not support the claim that parking-lot sealers are a significant source of PAHs in urban sediments.

  8. Source identification of aromatic hydrocarbons in sediments using GC/MS

    SciTech Connect

    Sporstoel, S.; Gjos, N.; Lichtenthaler, R.G.; Gustavsen, K.O.; Urdal, K.; Oreld, F.; Skel, J.

    1983-01-01

    A method that may distinguish between input of polycyclic aromatic hydrocarbons (PAH) from petroleum and combustion sources is demonstrated on sediment samples. Selected series of aromatics (unsubstituted compounds and their C/sub 1/-C/sub 3/ alkyl homologues) are quantified by computerized GC/MS. The alkyl homologue distribution (AHD) within each series and the sum of components in each series relative to the sum of all components measured (relative amount of each aromatic series (RAA)) are graphically visualized. In combination these parameters give a first-order indication of the PAH source. Pyrene/fluoranthene AHD series appear to be especially sensitive as an indicator for detecting PAH from combustion sources. Interestingly the dibenzothiophene AHD series does not discriminate between crude oil and soot samples. The method is demonstrated on sediments from the North Sea and from Norwegian and Swedish fjords.

  9. Parking lot sealcoat: an unrecognized source of urban polycyclic aromatic hydrocarbons

    SciTech Connect

    Barbara J. Mahler; Peter C. Van Metre; Thomas J. Bashara; Jennifer T. Wilson; David A. Johns

    2005-08-01

    Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. The authors show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealed lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads. 35 refs., 6 figs., 2 tabs.

  10. Parking lot sealcoat: An unrecognized source of urban polycyclic aromatic hydrocarbons

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Bashara, T.J.; Wilson, J.T.; Johns, D.A.

    2005-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. We show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealed lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads. ?? 2005 American Chemical Society.

  11. Aromatic hydrocarbons in the atmospheric environment: Part I. Indoor versus outdoor sources, the influence of traffic

    NASA Astrophysics Data System (ADS)

    Ilgen, Elke; Karfich, Natascha; Levsen, Karsten; Angerer, Jürgen; Schneider, Peter; Heinrich, Joachim; Wichmann, H.-Erich; Dunemann, Lothar; Begerow, Jutta

    Six aromatic hydrocarbons (benzene, toluene, ethylbenzene and the three isomeric xylenes) were monitored in the indoor and outdoor air of 115 private non-smoker homes (˜380 rooms), about half of which were located in two city streets in Hannover (Northern Germany) with high traffic density, the other half in rural areas with hardly any traffic at all. This environmental monitoring was complemented by human biomonitoring (i.e. the determination of aromatic hydrocarbons in blood and exhaled air). Particular attention was paid to benzene as a result of its carcinogenicity. In the city streets with high traffic density, an average benzene concentration of 3.1 μg m -3 and in the rural areas of 1.8 μg m -3 was found in these non-smoker homes (all data=geometric means), which reflects the influence of the traffic (automobile exhaust) on the benzene level found indoors. Source identification is also possible by determining the indoor/outdoor ( I/ O) concentration ratio. For the rooms facing the city street, this I/ O ratio is close to 1 for all aromatic hydrocarbons studied with the exception of toluene ( I/ O=3.5), while in the rural areas I/ O ratios for the individual compounds ranging in 6-9 were determined, with the exception of benzene where the I/ O ratio is only 1.5. These I/ O ratios in the city street with high traffic density indicate that an equilibrium between indoor and outdoor air is almost reached. Indoor sources prevail only in the case of toluene. In contrast, in the rural area, indoor sources dominate for all aromatic hydrocarbons except benzene, the indoor level of which is mainly influenced by the outdoor air even in areas of very low traffic density. However, weak indoor sources must exist also for this compound even in non-smoker homes. The internal exposure of the non-smoking inhabitants of these homes to benzene is very low. Depending on the living area, mean values of 61-67 ng l -1 benzene in blood and 0.9-1.2 μg m -3 in the exhaled air were

  12. Source apportionment of chlorinated polycyclic aromatic hydrocarbons associated with ambient particles in a Japanese megacity

    PubMed Central

    Kamiya, Yuta; Iijima, Akihiro; Ikemori, Fumikazu; Okuda, Tomoaki; Ohura, Takeshi

    2016-01-01

    Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are novel species of environmental contaminants whose possible sources remain unclear. The occurrence of ClPAHs within total suspended particles (TSP) is compared with weekly air samples at two sites of differing characteristics (industrial and residential) in the megacity of Nagoya, Japan. Samples were collected over 12 months during 2011–2012. All 24 species of targeted ClPAHs were detected at both industrial and residential sites, where mean concentrations of total ClPAHs in TSP were 20.7 and 14.1 pg/m3, respectively. High concentrations at the industrial site were frequently observed during winter, suggesting potent seasonal ClPAH sources there. Positive matrix factorization modeling of particulate ClPAH source identification and apportioning were conducted for datasets including ClPAHs, PAHs, elements and ions, plus elemental carbons in TSP. Eight factors were identified as possible ClPAH sources, with estimates that the dominant one was a specific source of ClPAH emission (31%), followed by traffic (23%), photodegradable and semi-volatile species (18%), long-range transport (11%), and industry and oil combustion (10%). Source contributions of ClPAHs differed substantially from those of PAHs. This suggests specific and/or potent ClPAH sources in the local area, and that the production mechanisms between ClPAHs and PAHs are substantially different. PMID:27922081

  13. Source apportionment of chlorinated polycyclic aromatic hydrocarbons associated with ambient particles in a Japanese megacity

    NASA Astrophysics Data System (ADS)

    Kamiya, Yuta; Iijima, Akihiro; Ikemori, Fumikazu; Okuda, Tomoaki; Ohura, Takeshi

    2016-12-01

    Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are novel species of environmental contaminants whose possible sources remain unclear. The occurrence of ClPAHs within total suspended particles (TSP) is compared with weekly air samples at two sites of differing characteristics (industrial and residential) in the megacity of Nagoya, Japan. Samples were collected over 12 months during 2011–2012. All 24 species of targeted ClPAHs were detected at both industrial and residential sites, where mean concentrations of total ClPAHs in TSP were 20.7 and 14.1 pg/m3, respectively. High concentrations at the industrial site were frequently observed during winter, suggesting potent seasonal ClPAH sources there. Positive matrix factorization modeling of particulate ClPAH source identification and apportioning were conducted for datasets including ClPAHs, PAHs, elements and ions, plus elemental carbons in TSP. Eight factors were identified as possible ClPAH sources, with estimates that the dominant one was a specific source of ClPAH emission (31%), followed by traffic (23%), photodegradable and semi-volatile species (18%), long-range transport (11%), and industry and oil combustion (10%). Source contributions of ClPAHs differed substantially from those of PAHs. This suggests specific and/or potent ClPAH sources in the local area, and that the production mechanisms between ClPAHs and PAHs are substantially different.

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

    NASA Astrophysics Data System (ADS)

    Liu, Jihua; Hu, Ningjing; Shi, Xuefa

    2015-04-01

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

  15. Evaluation of bioavailable hydrocarbon sources and their induction potential in Prince William Sound, Alaska.

    PubMed

    Springman, Kathrine R; Short, Jeffrey W; Lindeberg, Mandy; Rice, Stanley D

    2008-07-01

    To realistically evaluate the consequences of exposure to a complex mixture, we modified a passive sampler technology, the semipermeable membrane device (SPMD), which absorbs the bioavailable hydrophobic organic compounds present in an environment. These samplers were deployed in Prince William Sound (PWS), Alaska, at locations selected as potential sites of hydrocarbon deposition, as well as in random sites for regional assessment. Some of these sites were affected by previous human activity, such as canneries and salmon hatcheries, while others were sites of oil discharge as a consequence of the 1964 earthquake or the oil spill of T/V Exxon Valdez in 1989. The SPMDs were deployed for 27-28 d, processed, and then split, with one aliquot dedicated to chemical analysis and the other injected into juvenile rainbow trout (Oncorhynchus mykiss), along with the proper controls including a solvent control, field blank, and positive control. Trout fry were sacrificed after 2 or 7d, and their livers assayed for CYP1A induction by the standard bioassay for hydrocarbon exposure, the ethoxyresorufin-o-deethylase (EROD) assay. The results of this study were consistent and reproducible and showed that oil, whether deposited in 1964 or 1989, is still bioavailable as it can elicit as sustained response. Also, the same oil deposited in different sites of the same region has degraded differently, which is demonstrated by this method. Other putative sources of hydrocarbons, such as oil seeps, were dismissed as regional sources of induction agents as the responses following injection of modified SPMD extract from those sites did not differ significantly from the solvent control. This is a flexible, sensitive method that assesses the response to site-specific bioavailable contaminants and does so within the normal physiological response range of the target.

  16. The distribution and sources of polycyclic aromatic hydrocarbons in surface sediments along the Egyptian Mediterranean coast.

    PubMed

    El Nemr, Ahmed; Said, Tarek O; Khaled, Azza; El-Sikaily, Amany; Abd-Allah, Aly M A

    2007-01-01

    Coastal marine sediment samples were collected from 31 sampling stations along the Egyptian Mediterranean Sea coast. All sediment samples were analyzed to determine aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total concentrations of 16 EPA-PAHs in the sediments were varied from 88 to 6338 ng g(-1) with an average value of 154 ng g(-1) (dry weight). However, the concentrations of total aliphatic were varied from 1.3 to 69.9 ng g(-1) with an average value of 15.6 ng g(-1) (dry weight). The highest contents of PAHs were found in the Eastern harbor (6338 ng g(-1)), Manzala (5206 ng g(-1)) and El-Jamil East (4895 ng g(-1)) locations. Good correlations observed between a certain numbers of PAH concentrations allowed to identify its origin. The average total organic carbon (TOC) percent was varied from 0.91 to 4.54%. Higher concentration of total pyrolytic hydrocarbons ( summation operatorCOMB) than total fossil hydrocarbons ( summation operatorPHE) declared that atmospheric fall-out is the significant source of PAHs to marine sediments of the Egyptian Mediterranean coast. The selected marked compounds, a principal component analysis (PCA) and special PAHs compound ratios (phenanthrene/anthracene vs fluoranthene/pyrene; summation operatorCOMB/ summation operatorEPA-PAHs) suggest the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in most locations. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed in the harbors due to petroleum products deliveries and fuel combustion emissions from the ships staying alongside the quays.

  17. Biodiesel presence in the source zone hinders aromatic hydrocarbons attenuation in a B20-contaminated groundwater.

    PubMed

    Ramos, Débora Toledo; Lazzarin, Helen Simone Chiaranda; Alvarez, Pedro J J; Vogel, Timothy M; Fernandes, Marilda; do Rosário, Mário; Corseuil, Henry Xavier

    2016-10-01

    The behavior of biodiesel blend spills have received limited attention in spite of the increasing and widespread introduction of biodiesel to the transportation fuel matrix. In this work, a controlled field release of biodiesel B20 (100L of 20:80 v/v soybean biodiesel and diesel) was monitored over 6.2years to assess the behavior and natural attenuation of constituents of major concern (e.g., BTEX (benzene, toluene, ethyl-benzene and xylenes) and PAHs (polycyclic aromatic hydrocarbons)) in a sandy aquifer material. Biodiesel was preferentially biodegraded compared to diesel aromatic compounds with a concomitant increase in acetate, methane (near saturation limit (≈22mgL(-1))) and dissolved BTEX and PAH concentrations in the source zone during the first 1.5 to 2.0years after the release. Benzene and benzo(a)pyrene concentrations remained above regulatory limits in the source zone until the end of the experiment (6.2years after the release). Compared to a previous adjacent 100-L release of ethanol-amended gasoline, biodiesel/diesel blend release resulted in a shorter BTEX plume, but with higher residual dissolved hydrocarbon concentrations near the source zone. This was attributed to greater persistence of viscous (and less mobile) biodiesel than the highly-soluble and mobile ethanol in the source zone. This persistence of biodiesel/diesel NAPL at the source zone slowed BTEX and PAH biodegradation (by the establishment of an anaerobic zone) but reduced the plume length by reducing mobility. This is the first field study to assess biodiesel/diesel blend (B20) behavior in groundwater and its effects on the biodegradation and plume length of priority groundwater pollutants.

  18. Biodiesel presence in the source zone hinders aromatic hydrocarbons attenuation in a B20-contaminated groundwater

    NASA Astrophysics Data System (ADS)

    Ramos, Débora Toledo; Lazzarin, Helen Simone Chiaranda; Alvarez, Pedro J. J.; Vogel, Timothy M.; Fernandes, Marilda; do Rosário, Mário; Corseuil, Henry Xavier

    2016-10-01

    The behavior of biodiesel blend spills have received limited attention in spite of the increasing and widespread introduction of biodiesel to the transportation fuel matrix. In this work, a controlled field release of biodiesel B20 (100 L of 20:80 v/v soybean biodiesel and diesel) was monitored over 6.2 years to assess the behavior and natural attenuation of constituents of major concern (e.g., BTEX (benzene, toluene, ethyl-benzene and xylenes) and PAHs (polycyclic aromatic hydrocarbons)) in a sandy aquifer material. Biodiesel was preferentially biodegraded compared to diesel aromatic compounds with a concomitant increase in acetate, methane (near saturation limit (≈ 22 mg L- 1)) and dissolved BTEX and PAH concentrations in the source zone during the first 1.5 to 2.0 years after the release. Benzene and benzo(a)pyrene concentrations remained above regulatory limits in the source zone until the end of the experiment (6.2 years after the release). Compared to a previous adjacent 100-L release of ethanol-amended gasoline, biodiesel/diesel blend release resulted in a shorter BTEX plume, but with higher residual dissolved hydrocarbon concentrations near the source zone. This was attributed to greater persistence of viscous (and less mobile) biodiesel than the highly-soluble and mobile ethanol in the source zone. This persistence of biodiesel/diesel NAPL at the source zone slowed BTEX and PAH biodegradation (by the establishment of an anaerobic zone) but reduced the plume length by reducing mobility. This is the first field study to assess biodiesel/diesel blend (B20) behavior in groundwater and its effects on the biodegradation and plume length of priority groundwater pollutants.

  19. Top-down emission estimation of European sources of halogenated hydrocarbons using a Kalman-filter based inversion

    NASA Astrophysics Data System (ADS)

    Brunner, Dominik; Henne, Stephan; Keller, Christoph A.; Reimann, Stefan; Vollmer, Martin K.; O'Doherty, Simon

    2010-05-01

    Halogenated hydrocarbons in the atmosphere are mostly synthetic products of the chemical industry designed for a wide range of applications. The first generation of compounds, the bromine- and chlorine-containing halons and chlorofluorocarbons (CFCs), were shown to be harmful to the stratospheric ozone layer. This motivated the international community to initiate the Montreal Protocol in 1987 to phase out their production globally. In the industrialized countries CFCs were consequently replaced by the shorter-lived hydrochlorofluorocarbons (HCFCs) during the 1990s and thereafter by the completely chlorine-free HFCs. Although not harmful to the ozone layer anymore, some of the HFCs are potent greenhouse gases and are therefore regulated under the Kyoto Protocol. The high-alpine station Jungfraujoch and the coastal station Mace Head are two of only four sites of the European SOGE network (System for Observation of Halogenated Greenhouse Gases in Europe) with high-frequency measurements of halogenated compounds. Based on observations at these two sites, we here present a combined measurement - model analysis of the distribution of European emissions for a selection of compounds, and trace their evolution with time since measurements started in 2000. For the spatial allocation of sources, the measurements were combined with detailed transport simulations. For a qualitative allocation of sources in Europe we employed the trajectory statistics method of Seibert et al. (1994) and Stohl (1996). For Mace Head trajectories were computed with the FLEXPART model driven by ECMWF analyzed winds at 1°x1° resolution. For the station Jungfraujoch, however, we used the model COSMO-TRAJ driven by high-resolution wind fields (7 km x 7 km) of the weather forecast model COSMO of MeteoSwiss in order to better represent the transport in complex topography over the Alps. The method allows identifying the major source regions of the different compounds in Western and Central Europe. The

  20. Polycyclic Aromatic Hydrocarbons in the Dagang Oilfield (China): Distribution, Sources, and Risk Assessment

    PubMed Central

    Jiao, Haihua; Rui, Xiaoping; Wu, Shanghua; Bai, Zhihui; Zhuang, Xuliang; Huang, Zhanbin

    2015-01-01

    The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 27 upper layer (0–25 cm) soil samples collected from the Dagang Oilfield (China) in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs) varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1), to oil well areas (mean of 627.3 µg·kg−1), to urban and residential zones (mean of 1856 µg·kg−1). Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B) or not classified/non-carcinogenic (NB). The total concentrations of carcinogenic PAHs (∑BPAHs) varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk. PMID:26016436

  1. The qualitative and quantitative source apportionments of polycyclic aromatic hydrocarbons in size dependent road deposited sediment.

    PubMed

    Zhang, Jin; Wang, Jing; Hua, Pei; Krebs, Peter

    2015-02-01

    This study showcases the qualitative and quantitative source apportionments of size-dependent polycyclic aromatic hydrocarbons (PAHs) in road deposited sediment by means of molecular diagnostic ratio (MDR) and positive matrix factorisation (PMF) approaches. The MDR was initially used to narrow the PAH source candidates. PMF modelling was subsequently used to provide more precise source apportionment with the assistance of a multiple linear regression analysis. Through a combined qualitative and quantitative source apportionment, different potential source contributors were identified at different size fractions. Explicitly, three major contributors to sorption at the size fraction of 1000-400 μm were tentatively identified as incineration (26%), coal combustion (53%) and gasoline-powered vehicle (20%). Four major contributors to the size fraction of 400-100 μm were identified as gasoline-powered vehicle (25%), surface pavement (15%), diesel-powered vehicle (37%) and industrial boiler (24%). Four major contributors to the size fraction of 100-63 μm were identified as cogeneration emission (13%), diesel-powered vehicle (28%), tire debris (45%) and wood combustion (14%). The potential contributors in the size fraction 63-0.45 μm were identified as diesel-powered vehicle (21%), heterogeneous sources (41%) and biomass burning (38%). In addition, the highest ∑16PAH concentration was found in the smallest size fraction of 63-0.45 μm, which is also where the highest BaPE and TEF values for potential risk assessment occurred.

  2. Emission of polycyclic aromatic hydrocarbons and their carcinogenic potencies from cooking sources to the urban atmosphere.

    PubMed Central

    Li, Chun-The; Lin, Yuan-Chung; Lee, Wen-Jhy; Tsai, Perng-Jy

    2003-01-01

    Traffic has long been recognized as the major contributor to polycyclic aromatic hydrocarbon (PAH) concentrations. However, this does not consider the contribution of cooking sources of PAHs. This study set out, first, to assess the characteristics of PAHs and their corresponding benzo[a]pyrene equivalent (B[a]Peq) emissions from cooking sources to the urban atmosphere. To illustrate the importance of cooking sources, PAH emissions from traffic sources were then calculated and compared. The entire study was conducted on a city located in southern Taiwan. PAH samples were collected from the exhaust stacks of four types of restaurant: Chinese, Western, fast food, and Japanese. For total PAHs, results show that the fractions of gaseous PAHs (range, 75.9-89.9%) were consistently higher than the fractions of particulate PAHs (range, 10.1-24.1%) in emissions from the four types of restaurant. But for total B[a]Peq, we found that the contributions of gaseous PAHs (range, 15.7-21.9%) were consistently lower than the contributions of particulate PAHs (range, 78.1-84.3%). For emission rates of both total PAHs and total B[a]Peq, a consistent trend was found for the four types of restaurant: Chinese (2,038 and 154 kg/year, respectively) > Western (258 and 20.4 kg/year, respectively) > fast food (31.4 and 0.104 kg/year, respectively) > Japanese (5.11 and 0.014 kg/year, respectively). By directly adapting the emission data obtained from Chinese restaurants, we found that emission rates on total PAHs and total B[a]Peq for home kitchen sources were 6,639 and 501 kg/year, respectively. By combining both restaurant sources and home kitchen sources, this study yielded emission rates of total PAHs and total B[a]Peq from cooking sources of the studied city of 8,973 and 675 kg/year, respectively. Compared with PAH emissions from traffic sources in the same city, we found that although the emission rates of total PAHs for cooking sources were significantly less than those for traffic

  3. A chemical and thermodynamic model of oil generation in hydrocarbon source rocks

    NASA Astrophysics Data System (ADS)

    Helgeson, Harold C.; Richard, Laurent; McKenzie, William F.; Norton, Denis L.; Schmitt, Alexandra

    2009-02-01

    Thermodynamic calculations and Gibbs free energy minimization computer experiments strongly support the hypothesis that kerogen maturation and oil generation are inevitable consequences of oxidation/reduction disproportionation reactions caused by prograde metamorphism of hydrocarbon source rocks with increasing depth of burial.These experiments indicate that oxygen and hydrogen are conserved in the process.Accordingly, if water is stable and present in the source rock at temperatures ≳25 but ≲100 °C along a typical US Gulf Coast geotherm, immature (reduced) kerogen with a given atomic hydrogen to carbon ratio (H/C) melts incongruently with increasing temperature and depth of burial to produce a metastable equilibrium phase assemblage consisting of naphthenic/biomarker-rich crude oil, a type-II/III kerogen with an atomic hydrogen/carbon ratio (H/C) of ˜1, and water. Hence, this incongruent melting process promotes diagenetic reaction of detritus in the source rock to form authigenic mineral assemblages.However, in the water-absent region of the system CHO (which is extensive), any water initially present or subsequently entering the source rock is consumed by reaction with the most mature kerogen with the lowest H/C it encounters to form CO 2 gas and a new kerogen with higher H/C and O/C, both of which are in metastable equilibrium with one another.This hydrolytic disproportionation process progressively increases both the concentration of the solute in the aqueous phase, and the oil generation potential of the source rock; i.e., the new kerogen can then produce more crude oil.Petroleum is generated with increasing temperature and depth of burial of hydrocarbon source rocks in which water is not stable in the system CHO by a series of irreversible disproportionation reactions in which kerogens with higher (H/C)s melt incongruently to produce metastable equilibrium assemblages consisting of crude oil, CO 2 gas, and a more mature (oxidized) kerogen with a lower

  4. Source Identification of Polycyclic Aromatic Hydrocarbons by Diagnostic Ratios and Positive Matrix Factorization

    NASA Astrophysics Data System (ADS)

    Dvorska, A.; Jarkovsky, J.; Lammel, G.; Klanova, J.

    2009-04-01

    Although polycyclic aromatic hydrocarbons (PAHs) are also of natural origin, in many regions their environmental concentrations have strongly increased due to human activities. These semivolatile organic compounds are generally formed during incomplete combustion. Other sources include volatilization from unburned petroleum or tire abrasion in road traffic. Among all pollutants PAHs pose the highest human health hazard in Europe (WHO, 2003). A multivariate statistical method, positive matrix factorization (PMF; Paatero, 1997), and diagnostic ratios of individual PAHs (e.g. Yunker et al., 2002) are used for PAH source identification in central Europe. To minimise confounding factors such as differences in volatility, water solubility, adsorption etc., diagnostic ratios should be restricted to PAHs of similar molecular mass (Readman et al., 1987). Furthermore, different reactivities are limiting. Nevertheless, the application of PAH diagnostic ratios is often inconclusive, because substance patterns (profiles) have not been reported for all sources and ranges for various sources overlap. The complete profiles are made use of by statistical methods such as factor analysis, UNMIX and PMF (Tauler et al., 2006). However, these methods can be unreliable, because of incomplete knowledge of source profiles and the analysis' sensitivity to the data distribution. A unique 12-year data set of concentrations of PAHs (16 individual substances, 2 phases, weekly) in air, measured at the regional observatory Košetice, Czech Republic, is examined, together with shorter time series from Leipzig (urban background) and Schwartenberg (subalpine mountain background), Germany. Also, retene and coronene as specific source markers measured in Košetice from 2006 on are included into the analysis. An extensive literature search on PAH emission profiles was conducted. This data set was accomplished by measurements at sites in the Zlínsko region, Czech Republic, which are strongly dominated

  5. Investigation of sources of atmospheric polycyclic aromatic hydrocarbons at Mount Lushan in southern China

    NASA Astrophysics Data System (ADS)

    Li, Haiyan; Wang, Yan; Li, Hongli; Zhu, Chen; Mao, Huiting; Yang, Minmin; Wang, Ruixia; Wang, Wenxing

    2016-03-01

    Gaseous and particulate samples of polycyclic aromatic hydrocarbons (PAHs) were collected at the summit of Mount Lushan (29.58°N, 115.98°E, 1165 m asl) in southern China from August to September of 2011 and March to May of 2012 except special meteorological conditions such as rainy or very foggy days. The concentration of PAHs in total (gaseous and particulate PAHs) ranged from 15.79 to 160.53 ng m-3 (mean 41.67 ng m-3). Observed logarithmic values of particulate mass fraction (log θ) and partitioning coefficient (log Kp) were all higher than values calculated by the three gas-particle partitioning models, presenting higher fraction of particulate PAHs, indicating continual contribution of gaseous PAHs to particulate PAHs concentrations during long-range transport of air masses. Identified potential source regions using potential source contribution function analysis suggested significant contributions of emissions from coking, thermal power, and steel plants. The sources of PAHs levels at Mount Lushan that were identified using positive matrix factorization included diesel vehicles (43%), coal-fired boiler combustion (33%), coke oven source (17%), and incineration source (7%).

  6. Hydrocarbon emissions and characterization of methane sources in the Barnett Shale

    NASA Astrophysics Data System (ADS)

    Marrero, J. E.; Townsend-Small, A.; Meinardi, S.; Blake, D. R.

    2014-12-01

    As energy demand and costs continue to rise worldwide, so does the development of energy from natural gas. The United States in particular has expanded its natural gas industry, becoming one of the world's top gas producing countries. The Barnett Shale of northern Texas is one of the most developed and productive natural gas shale plays in the United States. However, emissions from the many oil and gas system components in the region have not been fully characterized. An extensive list of volatile organic compounds (VOCs) was measured from 120 whole air canisters collected throughout the Barnett shale in October 2013. Known methane sources were targeted and included oil and natural gas well pads, compressor stations, distribution pipelines and city gates, cattle feedlots and landfills. C1-C5 alkanes were elevated throughout the region and were similar to or greater than concentrations in major U.S. cities. The VOC source signature for oil and gas operations was distinguished from biogenic sources. Average ethane content relative to methane was calculated for each of the source types, and ranged from 0.7 to 12.8%. For the whole region, the ethane content was 7.2±6.1%, illustrating the high variability and effect of the various hydrocarbon sources on the local air.

  7. Urban rivers as conveyors of hydrocarbons to sediments of estuarine areas: source characterization, flow rates and mass accumulation.

    PubMed

    Mauad, Cristiane R; Wagener, Angela de L R; Massone, Carlos G; Aniceto, Mayara da S; Lazzari, Letícia; Carreira, Renato S; Farias, Cássia de O

    2015-02-15

    Aliphatic (n-C12-n-C40, unresolved complex mixture, resolved peaks) and aromatic hydrocarbons (46 PAH) were investigated in suspended particulate matter (SPM) sampled over eleven months in six of the major rivers and two channels of the Guanabara Bay Basin. PAH flow rates of the most contaminated rivers, the contribution to the PAH sediment load of the receiving bay, and the main sources of hydrocarbons were determined. PAH (38) ranged from 28 ng L(-1) to 11,514 ng L(-1). Hydrocarbon typology and statistical evaluation demonstrated contribution of distinct sources in different regions and allowed quantification of these contributions. Total flow rate for the five major rivers amounts to 3 t year(-1) and responds for 30% of the total PAH annual input into the northern area of the Guanabara Bay. For the first time PAH mass deposited in the bay sediments has been estimated and shall serve as base for decision making and source abatement.

  8. Distribution and sources of oxygenated non-hydrocarbons in topsoil of Beijing, China.

    PubMed

    Zhang, Zhihuan; Wan, Tiantian; Peng, Xuyang; He, Guangxiu; Liu, Yu; Zeng, Li

    2016-08-01

    The oxygenated non-hydrocarbon compounds are widely distributed in soil. To investigate the distribution and origin of these compounds in topsoil of Beijing, their contents and compositions were measured in topsoil from 62 sites in Beijing. The research results showed that oxygenated non-hydrocarbons were composed primarily of C6∼C28 n-fatty acids, C12∼C28 n-fatty alcohols, n-fatty acid methyl esters, phthalates, sterols, and dehydroabietic acid in the topsoil of Beijing. The contents and compositions of these compounds varied with the sampling site. The concentrations of n-fatty acids and phthalate esters were the highest at all sites, followed by sterols, n-fatty acid methyl esters, fatty alcohols, and dehydroabietic acid in order. The n-fatty acids had a main peak of C16, followed by C18. An odd or even carbon number predominance was not observed in the low-molecular-weight n-fatty acids, indicating a fossil fuel or organic matter source. However, some high-molecular-weight n-fatty acids with an even carbon predominance may derive from a biomass. The n-fatty alcohols showed a main peak of C22 and were predominated by an even carbon number, suggesting plant, microbial, or other natural origins. Phthalates, including diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and dimethylphthalate (DMP), were detected. The content of phthalate esters was higher in the samples collected from dense human activity areas. The concentrations of DBP, DEHP, and DIBP were relatively high, indicating an anthropogenic source. The sterols (predominantly β-sitosterol) originated from biological sources, especially plants. The n-fatty acid methyl esters and dehydroabietic acid in topsoil showed apparent even carbon predominance with the former mainly derived from microorganisms or plants and the latter from cork combustion products.

  9. Hydrocarbon migration and accumulation in the Upper Cretaceous Qingshankou Formation, Changling Sag, southern Songliao Basin: Insights from integrated analyses of fluid inclusion, oil source correlation and basin modelling

    NASA Astrophysics Data System (ADS)

    Dong, Tian; He, Sheng; Wang, Dexi; Hou, Yuguang

    2014-08-01

    The Upper Cretaceous Qingshankou Formation acts as both the source and reservoir sequence in the Changling Sag, situated in the southern end of the Songliao Basin, northeast China. An integrated approach involving determination of hydrocarbon charging history, oil source correlation and hydrocarbon generation dynamic modeling was used to investigate hydrocarbon migration processes and further predict the favorable targets of hydrocarbon accumulations in the Qingshankou Formation. The hydrocarbon generation and charge history was investigated using fluid inclusion analysis, in combination with stratigraphic burial and thermal modeling. The source rocks began to generate hydrocarbons at around 82 Ma and the hydrocarbon charge event occurred from approximately 78 Ma to the end of Cretaceous (65.5 Ma) when a large tectonic uplift took place. Correlation of stable carbon isotopes of oils and extracts of source rocks indicates that oil was generated mainly from the first member of Qingshankou Formation (K2qn1), suggesting that hydrocarbon may have migrated vertically. Three dimensional (3D) petroleum system modeling was used to evaluate the processes of secondary hydrocarbon migration in the Qingshankou Formation since the latest Cretaceous. During the Late Cretaceous, hydrocarbon, mainly originated from the Qianan depression, migrated laterally to adjacent structural highs. Subsequent tectonic inversion, defined as the late Yanshan Orogeny, significantly changed hydrocarbon migration patterns, probably causing redistribution of primary hydrocarbon reservoirs. In the Tertiary, the Heidimiao depression was buried much deeper than the Qianan depression and became the main source kitchen. Hydrocarbon migration was primarily controlled by fluid potential and generally migrated from relatively high potential areas to low potential areas. Structural highs and lithologic transitions are potential traps for current oil and gas exploration. Finally, several preferred hydrocarbon

  10. Source apportionment of sedimentary hydrocarbons in the Segara Anakan Nature Reserve, Indonesia.

    PubMed

    Syakti, Agung Dhamar; Hidayati, Nuning Vita; Hilmi, Endang; Piram, Anne; Doumenq, Pierre

    2013-09-15

    The study aimed to determine the spatial distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Segara Anakan nature reserve and their potential origins using gas chromatography-mass spectrometry. Total alkane concentrations ranged from 3755 to 129,027 μg kg(-1), and the concentrations of 16 PAHs ranged from 375 to 29,517 μg kg(-1). The ratios of specific n-alkanes (e.g., CPI(24-34), WaxC(n), and Paq), including a new proposed index, terrestrial-marine discriminant (TMD), as well as the ratios of selected PAHs (e.g., Ant/∑178, Fl/∑202, BaAnt/∑228, and IPyr/∑276), showed that the sources of hydrocarbons in the sediments were generally biogenic, including both terrigenous and marine, with an anthropogenic pyrolytic contribution (petrogenic and biogenic combustion). For the environmental risk assessment, a sediment quality guideline (SQGs) comparison indicated that the station risk levels ranged from low to medium-low, except for R6, which has a greater impact on the ecological risk for marine organisms.

  11. Factors affecting the pore space transformation during hydrocarbon generation in source rock (shales): laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.

    2014-12-01

    Oil and gas generation is a set of processes which taking place in the interior, the processes can't be observable in nature. In the process of dumping the source rock, organic matter is transformed into a complex of high-molecular compounds - precursors of oil and gas (kerogen). Entering of a source column for specific thermobaric conditions, triggers the formation of low molecular weight hydrocarbon compounds. Generation of sufficient quantities of hydrocarbons leads to the primary fluid migration within the source rock. For the experiment were selected mainly siliceous-carbonate composition rocks from Domanic horizon South-Tatar arch. The main aim of experiment was heating the rocks in the pyrolyzer to temperatures which correspond katagenes stages. For monitoring changes in the morphology of the pore space X-ray microtomography method was used. As a result, when was made a study of the composition of mineral and organic content of the rocks, as well as textural and structural features, have been identified that the majority of the rock samples within the selected collection are identical. However, characteristics such as organic content and texture of rocks are different. Thus, the experiment was divided into two parts: 1) the study of the influence of organic matter content on the morphology of the rock in the process of thermal effects; 2) study the effect of texture on the primary migration processes for the same values of organic matter. Also, an additional experiment was conducted to study the dynamics of changes in the structure of the pore space. At each stage of the experiment morphology of altered rocks characterized by the formation of new pores and channels connecting the primary voids. However, it was noted that the samples with a relatively low content of the organic matter had less changes in pore space morphology, in contrast to rocks with a high organic content. At the second stage of the research also revealed that the conversion of the pore

  12. Multi-source apportionment of polycyclic aromatic hydrocarbons using simultaneous linear equations

    NASA Astrophysics Data System (ADS)

    Marinaite, Irina; Semenov, Mikhail

    2014-05-01

    A new approach to identify multiple sources of polycyclic aromatic hydrocarbons (PAHs) and to evaluate the source contributions to atmospheric deposition of particulate PAHs is proposed. The approach is based on differences in concentrations of sums of PAHs with the same molecular weight among the sources. The data on PAHs accumulation in snow as well as the source profiles were used for calculations. Contributions of aluminum production plant, oil-fired central heating boilers, and residential wood and coal combustion were calculated using the linear mixing models. The concentrations of PAH pairs such as Benzo[b]fluorantene + Benzo[k]fluorantene and Benzo[g,h,i]perylene + Indeno[1,2,3-c,d]pyrene normalized to Benzo[a]antracene + Chrysene were used as tracers in mixing equations. The results obtained using ratios of sums of PAHs were compared with those obtained using molecular diagnostic ratios such as Benzo[a]antracene/Chrysene and Benzo[g,h,i]perylene/Indeno[1,2,3-c,d]pyrene. It was shown that the results obtained using diagnostic ratios as tracers are less reliable than results obtained using ratios of sums of PAHs. Funding was provided by Siberian Branch of Russian Academy of Sciences grant No. 8 (2012-2014).

  13. Toxicity evaluation and source apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) at three stations in Istanbul, Turkey.

    PubMed

    Hanedar, Asude; Alp, Kadir; Kaynak, Burçak; Avşar, Edip

    2014-08-01

    This paper focuses on the toxicity evaluation and source apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in three monitoring stations in Istanbul, Turkey. A total of 326 airborne samples were collected and analyzed for 16 PAHs and Total Suspended Particles (TSP) for the period of September 2006-December 2007. The total average PAH concentrations were 100.7±61.3, 84.6±46.7 and 25.1±13.3 ng m(-3) and the TSP concentrations were 101.2±53.2, 152.3±99.1, 49.8±18.6 μg m(-3) for URB1, URB2 and RUR stations, respectively. Benzo(a)Pyren (BaP) toxic equivalency factors to PAH concentration values were calculated indicating that the health risk of BaP and DiBenz(a,h)Anthracene (markers of traffic emissions) have the highest contribution compared to all of the other species measured at the sampling sites. In order to determine PAH sources, two different source apportionment techniques were applied to the measurements; diagnostic ratios (DR) and Positive Matrix Factorization (PMF). The results of the two applications were compatible indicating the vehicle emissions - especially diesel engines - as the major source for urban stations.

  14. Sources and distribution of aliphatic and polyaromatic hydrocarbons in coastal sediments from the Ushuaia Bay (Tierra del Fuego, Patagonia, Argentina).

    PubMed

    Commendatore, Marta G; Nievas, Marina L; Amin, Oscar; Esteves, José L

    2012-03-01

    The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 μg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation.

  15. Biomass burning sources of nitrogen oxides, carbon monoxide, and non-methane hydrocarbons

    SciTech Connect

    Atherton, C.S.

    1995-11-01

    Biomass burning is an important source of many key tropospheric species, including aerosols, carbon dioxide (CO{sub 2}), nitrogen oxides (NO{sub {times}}=NO+NO{sub 2}), carbon monoxide (CO), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), methyl bromide (CH{sub 3}Br), ammonia (NH{sub 3}), non-methane hydrocarbons (NMHCs) and other species. These emissions and their subsequent products act as pollutants and affect greenhouse warming of the atmosphere. One important by-product of biomass burning is tropospheric ozone, which is a pollutant that also absorbs infrared radiation. Ozone is formed when CO, CH{sub 4}, and NMHCs react in the presence of NO{sub {times}} and sunlight. Ozone concentrations in tropical regions (where the bulk of biomass burning occurs) may increase due to biomass burning. Additionally, biomass burning can increase the concentration of nitric acid (HNO{sub 3}), a key component of acid rain.

  16. [Contamination and source of polycyclic aromatic hydrocarbons in epikarst spring water].

    PubMed

    Sun, Yu-Chuan; Shen, Li-Cheng; Yuan, Dao-Xian

    2014-06-01

    The water samples were collected from four typical epikarst springs in Nanchuan District, Chongqing Municipality between October 2010 and October 2011. Sixteen priority polycyclic aromatic hydrocarbons in epikarst spring waters were quantitatively analyzed by the gas chromatography-mass spectrometer (GC-MS). The objectives of this study were to investigate the seasonal variations of polycyclic aromatic hydrocarbons' concentration, composition, source and contamination characterization in epikarst springs water. The results showed that the detection ratios of 16 PAHs in four springs were 100%. The total concentrations of 16 PAHs fluctuated greatly in epikarst spring water during one year observation, and the concentration ranged from 341 to 4 968 ng x L(-1), with a mean value of 1772 ng x L(-1). The total concentrations of 7 carcinogenic PAHs in rain season were all higher than those in dry season in four epikarst springs. The PAHs profiles were dominated by (2-3) rings PAHs in spring water, which accounted for more than 50% of 16 PAHs. The PAHs in spring water mainly originated from the combustion of coal, biomass and petroleum, and during June to October 2011, PAHs originated from the combustion of coal and biomass had a larger contribution. The ratios of Ant/( Ant + Phe) and Fla/( Fla + Pyr) changing with seasons showed that Ant, Phe, Fla and Pyr were easy to migrate in epikarst soils. In 4 isomeric ratios, the ratios of Fla/(Fla + Pyr) were more sensitive to reflect the information of sources. Compared to other areas in the world, the concentration of 16 PAHs in epikarst spring water is at a higher level, which shows the epikarst spring water has been suffered the PAHs pollution.

  17. Urinary metabolites of polycyclic aromatic hydrocarbons in Saudi Arabian schoolchildren in relation to sources of exposure.

    PubMed

    Alghamdi, Mansour A; Alam, Mohammed S; Stark, Christopher; Mohammed, Nuredin; Harrison, Roy M; Shamy, Magdy; Khoder, Mamdouh I; Shabbaj, Ibrahim I; Göen, Thomas

    2015-07-01

    Polycyclic aromatic hydrocarbons contain a number of known carcinogenic compounds, and urinary biomarkers have been widely used as a measure of exposure but quantitative relationships with exposure variables have proved elusive. This study aimed to quantify the relationship between exposures to phenanthrene and pyrene from atmospheric and dietary sources with the excretion of 1-hydroxypyrene and hydroxyphenanthrenes in urine as biomarkers of exposure. The study population consisted of 204 male schoolchildren attending three schools in different parts of Jeddah, Saudi Arabia who provided urine samples on each of three consecutive days. Outdoor air measurements of polycyclic aromatic hydrocarbons were made at the schools and the children provided information on diet, exposure to environmental tobacco smoke and incense, and various lifestyle factors through a questionnaire. Mixed models with random effects for subjects nested within site were fitted in order to examine the relationship between exposure variables and urinary PAH metabolites. A unit increase (1 ng m(-3)) in ambient pyrene (particulate plus gaseous phase) was associated with a 3.5% (95% CI: 1.01%, 5.13%) increase in urinary 1-hydroxypyrene concentration. A unit increase in ambient phenanthrene was associated with a 1.01% (95% CI: 0.03%, 2.02%) increase in total hydroxyphenanthrene concentrations. Consumption of chargrilled food increased the 1-hydroxypyrene and hydroxyphenanthrene concentrations by 24% (95% CI: 11%, 37%) and 17% (95% CI: 8%, 26%) respectively. We did not find evidence of association for environmental tobacco smoke exposure or incense burning. It is concluded that both respiratory exposure and consumption of chargrilled food are considerable sources of PAH exposure in this population as reflected by concentrations of urinary biomarkers.

  18. Road-network-Based spatial allocation of on-road mobile source emissions in the Pearl River Delta region, China, and comparisons with population-based approach.

    PubMed

    Zheng, Junyu; Che, Wenwei; Wang, Xuemei; Louie, Peter; Zhong, Liuju

    2009-12-01

    Gridded air pollutant emission inventories are prerequisites for using air quality models to assess air pollution control strategies and predict air quality. A precise gridded emission inventory will help improve the accuracy of air quality simulation. Mobile source emissions are one of the major contributors to volatile organic compound (VOC) and nitrogen oxide (NOx) pollutants, the precursors of ozone formation. However, because of the complexity of road networks and variations in traffic flows at different road types and locations, spatial allocation of emissions from mobile sources into grid cells is challenging. This paper proposes a new methodological framework, named as "the road-network-based approach," for spatially allocating regional mobile source emission inventories. The new approach utilizes the Geographic Information System (GIS)-based road network information and road-types-based traffic flow data to provide spatial surrogates for allocating Pearl River Delta (PRD) regional mobile source emission inventories. The results show that the new approach provides reasonable spatial distributions of mobile source emissions, and the distributions are in good agreement with PRD regional on-road emission line sources. Comparisons between using the population-based and the new road-network-based approaches are made. The air quality modeling results indicate that the new approach can obviously improve model predictions with increasing accuracy in mobile source emission allocations. Means of choosing appropriate approaches for spatially allocating regional mobile source emissions are discussed.

  19. Sources and deposition of polycyclic aromatic hydrocarbons to Western U.S. national parks.

    PubMed

    Usenko, Sascha; Simonich, Staci L Massey; Hageman, Kimberly J; Schrlau, Jill E; Geiser, Linda; Campbell, Don H; Appleby, Peter G; Landers, Dixon H

    2010-06-15

    Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) to determine their current and historical deposition, as well as to identify their potential sources. Seasonal snowpack was measured to determine the current wintertime atmospheric PAH deposition; lichens were measured to determine the long-term, year around deposition; and the temporal PAH deposition trends were reconstructed using lake sediment cores dated using (210)Pb and (137)Cs. The fourteen remote lake catchments ranged from low-latitude catchments (36.6 degrees N) at high elevation (2900 masl) in Sequoia National Park, CA to high-latitude catchments (68.4 degrees N) at low elevation (427 masl) in the Alaskan Arctic. Over 75% of the catchments demonstrated statistically significant temporal trends in SigmaPAH sediment flux, depending on catchment proximity to source regions and topographic barriers. The SigmaPAH concentrations and fluxes in seasonal snowpack, lichens, and surficial sediment were 3.6 to 60,000 times greater in the Snyder Lake catchment of Glacier National Park than the other 13 lake catchments. The PAH ratios measured in snow, lichen, and sediment were used to identify a local aluminum smelter as a major source of PAHs to the Snyder Lake catchment. These results suggest that topographic barriers influence the atmospheric transport and deposition of PAHs in high-elevation ecosystems and that PAH sources to these national park ecosystems range from local point sources to diffuse regional and global sources.

  20. Source and sink carbon dynamics and carbon allocation in the Amazon basin

    NASA Astrophysics Data System (ADS)

    Doughty, Christopher E.; Metcalfe, D. B.; Girardin, C. A. J.; Amezquita, F. F.; Durand, L.; Huaraca Huasco, W.; Silva-Espejo, J. E.; Araujo-Murakami, A.; Costa, M. C.; Costa, A. C. L.; Rocha, W.; Meir, P.; Galbraith, D.; Malhi, Y.

    2015-05-01

    Changes to the carbon cycle in tropical forests could affect global climate, but predicting such changes has been previously limited by lack of field-based data. Here we show seasonal cycles of the complete carbon cycle for 14, 1 ha intensive carbon cycling plots which we separate into three regions: humid lowland, highlands, and dry lowlands. Our data highlight three trends: (1) there is differing seasonality of total net primary productivity (NPP) with the highlands and dry lowlands peaking in the dry season and the humid lowland sites peaking in the wet season, (2) seasonal reductions in wood NPP are not driven by reductions in total NPP but by carbon during the dry season being preferentially allocated toward either roots or canopy NPP, and (3) there is a temporal decoupling between total photosynthesis and total carbon usage (plant carbon expenditure). This decoupling indicates the presence of nonstructural carbohydrates which may allow growth and carbon to be allocated when it is most ecologically beneficial rather than when it is most environmentally available.

  1. A source study of atmospheric polycyclic aromatic hydrocarbons in Shenzhen, South China.

    PubMed

    Liu, Guoqing; Tong, Yongpeng; Luong, John H T; Zhang, Hong; Sun, Huibin

    2010-04-01

    Air pollution has become a serious problem in the Pearl River Delta, South China, particularly in winter due to the local micrometeorology. In this study, atmospheric polycyclic aromatic hydrocarbons (PAHs) were monitored weekly in Shenzhen during the winter of 2006. Results indicated that the detected PAHs were mainly of vapor phase compounds with phenanthrene dominant. The average vapor phase and particle phase PAHs concentration in Shenzhen was 101.3 and 26.7 ng m( - 3), respectively. Meteorological conditions showed great effect on PAH concentrations. The higher PAHs concentrations observed during haze episode might result from the accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. The sources of PAHs in the air were estimated by principal component analysis in combination with diagnostic ratios. Vehicle exhaust was the major PAHs source in Shenzhen, accounting for 50.0% of the total PAHs emissions, whereas coal combustion and solid waste incineration contributed to 29.4% and 20.6% of the total PAHs concentration, respectively. The results clearly indicated that the increasing solid waste incinerators have become a new important PAHs source in this region.

  2. 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.

  3. Hydrocarbon source apportionment in Mexico City using the chemical mass balance receptor model

    NASA Astrophysics Data System (ADS)

    Vega, Elizabeth; Mugica, Violeta; Carmona, Rocío.; Valencia, Edgar

    A field study was conducted in Mexico City during May-November 1997 to determine non-methane hydrocarbons (NMHC) species emitted from different sources: application of slow curing asphalt pavement, liquefied petroleum gas (vapour phase), dry cleaning, graphic arts, landfill, emissions of motor vehicle exhaust inside a tunnel, hot soak, whole gasoline, painting operations and degreasing. Forty-five ambient air samples of NMHC were simultaneously collected from 6:00 to 9:00 a.m. at three different sites, Xalostoc, Pedregal and La Merced, denominated receptors, during the spring and fall of 1996. In both cases samples were collected in stainless-steel canisters and analysed by gas chromatography with flame ionisation detection system. Based on these measurements the chemical mass receptor model (CMB) was applied to estimate the contribution of the different NMHC source to ambient pollution. The average results for the two sampling periods showed that the major sources of NMHC for the three sites were: motor vehicle exhaust with an average contribution of 54.9, 57.4 and 63.8% for Xalostoc, Pedregal and La Merced, respectively, followed by handling and distribution of liquefied petroleum gas with 28.5% in Xalostoc, 20.0% in Pedregal and 24.0% in La Merced.

  4. Source Apportionment of Particle Bound Polycyclic Aromatic Hydrocarbons at an Industrial Location in Agra, India

    PubMed Central

    Lakhani, Anita

    2012-01-01

    16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were quantified in total suspended ambient particulate matter (TSPM) collected from an industrial site in Agra (India) using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline. PMID:22606062

  5. Polycyclic aromatic hydrocarbons in surface sediment from Yangpu Bay, China: Distribution, sources and risk assessment.

    PubMed

    Li, Ping; Diao, Xiaoping; Zhang, Yu; Xie, Yanli; Yang, Fei; Zhou, Hailong; Han, Qian; Wang, Fuqiang; Cheng, Huamin; Wang, Haihua

    2015-10-15

    The study investigated the occurrence of polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from eleven sites in Yangpu Bay, China in December 2013 (winter) and July 2014 (summer). The 16 US EPA priority PAHs were found in the range of 1583.2-5701.7 ng/g dry weights with an average of 3134.7 ± 1241.3 ng/g in winter and ranged from 2161.8 to 4527.2 ng/g with an average of 3016.6 ± 748.0 ng/g in summer, respectively. The concentrations of the PAHs tended to be relatively high in comparison with other areas from the literatures. The identification using molecular indices analysis indicated that the PAHs originated mainly from pyrogenic and petrogenic sources in most of the sites. According to principle component analysis-multiple linear regression (PCA/MLR) for their source apportionment, the main sources of PAHs were vehicle emissions, petroleum products and biomass combustion. The risk assessment using international sediments quality guidelines and sediments quality criteria indicated that several PAHs, such as Nap, Flu, Phe, Ace, Acy and BghiP in most of the sites would potentially affect organisms in Yangpu Bay.

  6. Polycyclic aromatic hydrocarbons in urban street dust: sources and health risk assessment.

    PubMed

    Wang, Xue Song

    2017-02-09

    Urban street dust samples from 49 sampling sites in Xuzhou (China) were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) using gas chromatography/mass spectrometry. The organic matter and total carbon contents were also determined. The results showed that total PAHs concentrations varied from 2174 to 24,499 ng/g with a mean value of 6616 ng/g, organic matter content varied from 3.1 to 8.7% with a mean value of 5.8%, total carbon content varied from 13.2 to 24.2%, with a mean value of 19.9%. Total carbon content was found to show a significant correlation with total PAHs concentration, but such a relationship with total PAHs concentration was only weakly identified for organic matter content. Source Apportionment Techniques indicated pyrogenic sources were the main source of PAHs in urban street dust. The total incremental lifetime cancer risk, including dermal contact, ingestion and inhalation exposure pathways, was estimated to be 4.12 × 10(-6) and 3.98 × 10(-6) for children and adults, respectively.

  7. Source apportionment of particle bound polycyclic aromatic hydrocarbons at an industrial location in Agra, India.

    PubMed

    Lakhani, Anita

    2012-01-01

    16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) were quantified in total suspended ambient particulate matter (TSPM) collected from an industrial site in Agra (India) using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m(-3). Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline.

  8. Polycyclic aromatic hydrocarbons in surface sediments from drinking water sources of Taihu Lake, China: sources, partitioning and toxicological risk.

    PubMed

    Tao, Yuqiang; Yao, Shuchun; Xue, Bin; Deng, Jiancai; Wang, Xiaolong; Feng, Muhua; Hu, Weiping

    2010-12-01

    Sources, partitioning and toxicological risk of 15 priority polycyclic aromatic hydrocarbons (PAHs) in surface sediments from drinking water sources of Taihu Lake, with an area of 2428 km(2) located in the most developed and populated area of China, were studied, and the results were compared with those in other lakes of China and the USA. Concentrations of the 15 PAHs in sediments ranged from 436.6 to 1334.9 ng g(-1) (dw). Gasoline combustion, coal combustion, diesel combustion from shipping and spillage of petroleum were apportioned to be the main sources of PAHs in this area by principal component analysis, which contributed 35.19%, 26.43%, 25.41% and 12.97% to the PAH sources estimated by further multiple linear regression. Levels of PAHs in sediments were negatively correlated with contents of clay and fine silt (<16 μm), while positively with contents of medium silt, coarse silt and sand (>16 μm). Humin with size larger than 16 μm contained the largest part of the burden of PAHs in sediments, but the specific partitioning domain (bound humic acid, lipid or insoluble residue) depended on properties of organic matter reflected by optical absorbance at 465 and 665 nm. Total toxic benzo[a]pyrene equivalent (TEQ(carc)) of the carcinogenic PAHs in sediments varied from 31.8 to 209.3 ngTEQ(carc) g(-1). Benzo[a]pyrene and dibenzo[a,h]anthracene contributed 45.36 and 25.31% to total TEQ(carc), posing high toxicological risk to this area.

  9. Evaluating the time and source of hydrocarbon additions to soils using lead isotopes and historical changes in industrial lead sources

    SciTech Connect

    Hurst, R.W. California State Univ., Los Angeles, CA )

    1994-04-01

    Isotopic analysis of anthropogenic Pb in well-dated, southern California coastal sediments have been integrated with historical changes in ore Pb sources to produce calibration curves (206Pb/207Pb vs. time) that allow us to model the time anthropogenic Pb was added to a soil horizon. The major, historical sources of anthropogenic Pb in southern California are fossil fuels (e.g. gasoline). Hence, Pb model ages (LABILE model; Los Angeles Borderland Industrial Lead) provide time constraints on Pb deposition from fossil fuel combustion via airborne deposition, runoff, and/or sewage outfall in this region. The correlation between the LABILE model age and known times of anthropogenic Pb additions at 17 specific sites is good (r = 0.978); the accuracy of the method ranges from one to five years in the post-1960 time interval. Factors influencing accuracy include analytical uncertainties in Pb isotopic measurements ([<=]0.1%), the scatter in isotopic ratios of anthropogenic Pb (circa 0.2%), and the uncertainty in the sediment age used to calibrate the method (0-15 yr). At one site three statistically distinguishable events were identified; they correlate with residential development (1968), airborne vehicular Pb deposition (1983), and site remediation (1991). Gasoline incursions at two tests sites have been dated accurately ([+-] 1 yr). The limitations of the LABILE model (geographic, age, types of hydrocarbons, and industry to which it applies) are now under investigation.

  10. Source Contribution Analysis of Surface Particulate Polycyclic Aromatic Hydrocarbon Concentrations in Northeastern Asia by Source-receptor Relationships

    SciTech Connect

    Inomata, Yayoi; Kajino, Mizuo; Sato, Keiichi; Ohara, Toshimasa; Kurokawa, Jun-Ichi; Ueda, Hiromasa; Tang, Ning; Hayakawa, Kazuichi; Ohizumi, Tsuyoshi; Akimoto, Hajime

    2013-11-01

    We analyzed the sourceereceptor relationships for particulate polycyclic aromatic hydrocarbon (PAH) concentrations in northeastern Asia using an aerosol chemical transport model. The model successfully simulated the observed concentrations. In Beijing (China) benzo[a]pyren (BaP) concentrations are due to emissions from its own domain. In Noto, Oki and Tsushima (Japan), transboundary transport from northern China (>40°N, 40-60%) and central China (30-40°N, 10-40%) largely influences BaP concentrations from winter to spring, whereas the relative contribution from central China is dominant (90%) in Hedo. In the summer, the contribution from Japanese domestic sources increases (40-80%) at the 4 sites. Contributions from Japan and Russia are additional source of BaP over the northwestern Pacific Ocean in summer. The contribution rates for the concentrations from each domain are different among PAH species depending on their particulate phase oxidation rates. Reaction with O3 on particulate surfaces may be an important component of the PAH oxidation processes.

  11. Hydrocarbon source apportionment for the 1996 Paso del Norte Ozone Study.

    PubMed

    Fujita, E M

    2001-08-10

    The 1996 Paso del Norte (PdN) ozone study was conducted to improve current understanding of the significant meteorological and air quality processes that lead to high concentrations of ozone in El Paso, Texas (USA) and Ciudad Juárez, Chihuahua (Mexico). Two-hour canister samples were collected five times daily at 05.00-07.00 h, 07.00-09.00 h, 09.00-11.00 h, 11.00-13.00 h, and 15.00-17.00 h MST during intensive study periods at one urban and one rural site on each side of the border. An automated gas chromatograph was operated at one site in central El Paso. Source profiles (the fractional chemical composition of emissions) from motor vehicles, gasoline, liquefied petroleum gas, and commercial natural gas were combined with source profiles from other studies for input to the Chemical Mass Balance (CMB) receptor model to apportion the measured non-methane hydrocarbons (NMHC) to sources. On-road vehicle emissions accounted for one-half to two-thirds of the NMHC in Ciudad Juárez and El Paso with the highest contributions occurring during the morning and afternoon commute periods. Emissions from diesel exhaust contributed approximately 2-3% of NMHC in Ciudad Juárez and less than 2% in El Paso. The average sum of liquid gasoline and gasoline vapor increased during the day in Ciudad Juárez from 2% at 06.00 h to approximately 12% at 16.00 h. Diurnal and day-of-the-week patterns in the liquid gasoline contributions are essentially identical to the corresponding patterns for motor vehicle exhaust, which suggest that a large fraction of the liquid gasoline contribution may be associated with tailpipe emissions rather than evaporative emissions from motor vehicles or industrial sources. Including the sum of the two sources put the upper limit for tailpipe contributions at 60-70% of NMHC.

  12. Sources, distribution, and water column processes of aliphatic and polycyclic aromatic hydrocarbons in the northwestern Black Sea water

    SciTech Connect

    Maldonado, C.; Bayona, J.M.; Bodineau, L.

    1999-08-15

    Aliphatic and aromatic hydrocarbons have been determined in suspended particulate matter collected at subsurficial seawater and three vertical profiles in a transect from the continental shelf, slope, and deep basin of the western Black Sea. The dissolved phase was collected at subsurficial and in the redoxcline. The highest concentrations of hydrocarbons were detected in the Danube, Dnieper, and Dniester River Estuaries and other point sources of pollution located offshore Romania and Bulgaria where oil production and refining is carried out. Concentrations of hydrocarbons decreased with increasing distance from the coast, but relatively high concentrations were found at the open stations where the particulate organic carbon (POC) is higher. Fossil PAHs are predominant in the coastal stations, and the unresolved complex mixture (UCM) of aliphatic hydrocarbons is predominantly of a fossil common origin according to the hopane and sterane distribution. The fossil to pyrolytic PAH ratio decreases with source distance attributable to a deposition of pyrolytic PAHs. The spatial distribution of PAHs found in the dissolved phase is evenly distributed. The unresolved complex mixture/alkane ratio is higher in the dissolved phase and can be attributable to a faster degradation of labile n-alkanes in this phase. Vertical profiles of hydrocarbons in suspended particles show two submaxima located in the biomass maximum abundance and at the redoxcline where there is an enrichment referred to POC due to phytoplankton or bacteria uptake, respectively.

  13. Source identification of hydrocarbon contaminants and their transportation over the Zonguldak shelf, Turkish Black Sea

    NASA Astrophysics Data System (ADS)

    Unlu, S.; Alpar, B.

    2009-04-01

    Under great anthropogenic pressure due to the substantial freshwater input from the surrounding industrial and agricultural areas, especially central and middle-Eastern Europe, the Black Sea basin is ranked among the most ecologically threatened water bodies of the world. Oil levels are unacceptable in many coastal areas perilously close to polluted harbors and many river mouths; the places presenting the highest levels of bio-diversity and having a high socio-economic importance due to human use of coastal resources. There are about sixty sources of pollution which resulted in "hot spots" having disastrous impacts on sensitive marine and coastal areas and needing immediate priorities for action. Beyond such land-based sources, trans-boundary pollution sources from Black Sea riparian countries, heavy maritime traffic, particularly involving petroleum transports and fishing boats, and the improper disposal of ballast and bilge waters and solid waste are also important marine sources of pollution. Found in fossil fuels such as Polycyclic Aromatic Hydrocarbons are generated by incomplete combustion of organic matter. In order to estimate their distribution in sediment and their sources, they were monitored from the bottom samples offshore the Zonguldak industry region, one of the most polluted spots in the Turkish Black Sea. There the budget of pollutants via rivers is not precisely known due to an evident lack of data on chemical and granulometric composition of the river runoff and their fluxes. Therefore the marine sediments, essential components of marine ecosystems, are very important in our estimating the degree of the damage given to the ecosystem by such inputs. Realization of the sources and transport of these contaminants will be a critical tool for future management of the Zonguldak industry region and its watershed. The sea bottom in study area is composed of mainly sand and silt mixtures with small amount of clay. Geochemical analyses have shown that oil

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  16. [Pollution characteristics and sources of polycyclic aromatic hydrocarbons in urban rivers of Wenzhou city].

    PubMed

    Zhou, Jie-Cheng; Chen, Zhen-Lou; Bi, Chun-Juan; Lü, Jin-Gang; Xu, Shi-Yuan; Pan, Qi

    2012-12-01

    Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) in water and surface sediments collected from the urban rivers of Wenzhou city in spring and summer were measured by GC-MS. The results showed that the total PAHs concentrations in water and sediments of the studied rivers varied in ranges of 146.74-3 047.89 ng x L(-1) and 21.01-11 990.48 ng x g(-1), respectively. Higher concentrations occurred in spring. The low and middle rings of 2-4-ring were dominant in both water and sediments, but the concentrations of 5-ring and 6-ring PAHs in sediments were relatively higher than those in water. The EBaP values of PAHs in water of the studied rivers in spring and summer were 1.69-51.95 ng x L(-1) and 0-3.03 ng x L(-1), respectively. Eighty percent of water samples in spring surpassed the limits of BaP in surface water of China. The concentrations of sigma PAHs in the sediments both in spring and summer were lower than the ERM value, but part of the components of PAHs had values higher than the ERM, suggesting possible toxic effect on living organisms. Based on the PAHs molecule ratios and principal component analysis, a mixed PAHs source of petroleum and combustion in water and sediments was diagnosed, while sediments showed a greater proportion of combustion sources.

  17. Organic composition of atmospheric urban aerosol: Variations and sources of aliphatic and polycyclic aromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Mazquiarán, Miguel A. Barrero; Cantón Ortiz de Pinedo, Lourdes

    2007-09-01

    The non-polar organic composition of airborne particulate matter was analysed over a two year period in an urban area under oceanic climate conditions (Errenteria, Basque Country, Spain). In addition, the distribution of polycyclic aromatic hydrocarbons (PAH) among different aerosol particle sizes was determined. Clues as to the origin of various particle types were gained by using scanning electron microscopy to view the morphology of the particulates in each size fraction. Samples were collected on glass fibre filters and analysed by means of soxhlet extraction and gas chromatography (either with a flame ionization detector or coupled to a mass spectrometry). In general, total PAH levels were moderate (0.96-50 ng m - 3 ) as compared to other studies conducted in Europe, and showed clear seasonal variation with maxima in winter and minima in summer. Vehicular traffic was identified as a major source of PAHs in the study area. Regarding particle size, a bimodal distribution was observed. The large sized particles exhibited an apparent seasonal variation with higher concentrations in winter than in summer. The dependences between particle size, PAH distribution and meteorological variables were studied with multivariate statistics. Three main sources of organic compounds were identified: combustion, vegetation, and atmospheric oxidation.

  18. Parking lot sealcoat: a major source of polycyclic aromatic hydrocarbons (PAHs) in urban and suburban environments

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.; Scoggins, Mateo; Hamilton, Pixie A.

    2005-01-01

    Collaborative studies by the City of Austin and the U. S. Geological Survey (USGS) have identified coal-tar based sealcoat—the black, shiny emulsion painted or sprayed on asphalt pavement such as parking lots—as a major and previously unrecognized source of polycyclic aromatic hydrocarbon (PAH) contamination. Several PAHs are suspected human carcinogens and are toxic to aquatic life. Studies in Austin, Texas, showed that particles in runoff from coal-tar based sealcoated parking lots had concentrations of PAHs that were about 65 times higher than concentrations in particles washed off parking lots that had not been sealcoated. Biological studies, conducted by the City of Austin in the field and in the laboratory, indicated that PAH levels in sediment contaminated with abraded sealcoat were toxic to aquatic life and were degrading aquatic communities, as indicated by loss of species and decreased numbers of organisms. Identification of this source of PAHs may help to improve future strategies for controlling these compounds in urban water bodies across the Nation where parking lot sealcoat is used.

  19. Polystyrene plastic: a source and sink for polycyclic aromatic hydrocarbons in the marine environment

    PubMed Central

    Rochman, Chelsea M.; Manzano, Carlos; Hentschel, Brian T.; Massey Simonich, Staci L.; Hoh, Eunha

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) on virgin polystyrene (PS) and PS marine debris led us to examine PS as a source and sink for PAHs in the marine environment. At two locations in San Diego Bay, we measured sorption of PAHs to PS pellets, sampling at 0, 1, 3, 6, 9 and 12 months. We detected 25 PAHs using a new analytical method with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. Several congeners were detected on samples before deployment. After deployment, some concentrations decreased (1,3-dimethylnaphthalene and 2,6-methylnaphthalene) while most increased (2-methylanthracene and all parent PAHs (PPAHs) except fluorene and fluoranthene), suggesting PS debris is a source and sink for PAHs. When comparing sorbed concentrations of PPAHs on PS to the five most common polymers (polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP)), PS sorbed greater concentrations than PP, PET and PVC, similar to HDPE and LDPE. Most strikingly, at 0 months, PPAHs on PS ranged from 8-200 times greater than on PET, HDPE, PVC, LDPE, and PP. The combination of greater PAHs in virgin pellets and large sorption suggests that PS may pose a greater risk of exposure to PAHs upon ingestion. PMID:24341360

  20. Searching ingredients polluted by polycyclic aromatic hydrocarbons in feeds due to atmospheric or pyrolytic sources.

    PubMed

    Yebra-Pimentel, Iria; Fernández-González, Ricardo; Martínez Carballo, Elena; Simal-Gándara, Jesús

    2012-12-01

    The primary aim of the proposed work is to propose the potential sources of pollution by polycyclic aromatic hydrocarbons (PAHs) in feeds and ingredients. To reach this propose the development of a simple, fast, quantitative and economic method for determining PAHs using liquid-liquid extraction (LLE), clean-up and detection by liquid chromatography with fluorescence detection (LC-FD) in polluting feeds and ingredients was developed. The overall method quantification limits range from 0.020 to 4.0μg/kg and analyte recoveries are between 70% and 105% with relative standard deviations (RSD) lower than 20%. Molecular patterns of PAHs were used to study their distribution in the selected samples by cluster analysis, separating them in two groups: contaminated by atmospheric or pyrolytic sources. In order to find a relationship between the nutritional composition (protein, fibre, ash and fat content), and the hypothetical toxicity of selected feeds, a partial least squared (PLS) analysis was used, showing that fibre was a major contributor. Moreover, the complete data set of 27 feed samples and 25 feed ingredients x 13 PAH concentrations were analysed by PCA to find out what ingredients were controlling PAH pollution.

  1. Hydrocarbon potential of Cretaceous sediments in the Lower and Middle Benue Trough, Nigeria: Insights from new source rock facies evaluation

    NASA Astrophysics Data System (ADS)

    Akande, Samuel O.; Egenhoff, Sven O.; Obaje, Nuhu G.; Ojo, Olusola J.; Adekeye, Olabisi A.; Erdtmann, Bernd D.

    2012-02-01

    The Nigerian Benue Trough is an intracratonic rift structure which evolution is related to the Early Cretaceous opening of the South Atlantic Ocean and the Gulf of Guinea. Previous hydrocarbon potential assessments of the successions in the trough revealed a number of organic rich intervals capable of yielding significant quantities of hydrocarbons in the Cretaceous sections. Stratigraphic continuity of these intervals suggests their potentials for hydrocarbons if thermally mature and both oil and gas can be generated. The present study have expanded on some previously reported source rock data of the Cretaceous formations in the Benue Trough by detailed mapping of the stratigraphic intervals with source rock potentials on the basis of their structural setting, lithologic characteristics, and depositional environments. Further characterization of the organic matter within the Cenomanian to Coniacian on one hand and the Campanian to Maastrichtian intervals were carried out to determine the geochemical character of the organic rich zones, their maturity and effectiveness to generate and expel hydrocarbons. In the Lower Benue Trough, mature facies of the Cenomanian to Turonian Eze-Aku Formation with a predominance of Types II and III kerogen, the Turonian to Coniacian Type III dominated Awgu Formation and the Type III dominated Lower Maastrichtian sub-bituminous coals of the Mamu Formation have proven potentials as oil and gas source rocks. In the Middle Benue Basin, the preserved mature intervals of the Awgu Formation shales and coals are good gas source rocks with some oil prone units in view of the predominating Type III kerogen. Targets for hydrocarbons generated by these source rock intervals should focus on the non-emergent Cretaceous reservoirs within the pre-Santonian successions whereas, the mature equivalents of the sub-bituminous coal facies would generate and charge both Upper Cretaceous reservoirs and possibly the sub-Niger Delta successions in the sub-surface.

  2. HYDROCARBON SOURCE ROCK EVALUATION OF MIDDLE PROTEROZOIC SOLOR CHURCH FORMATION, NORTH AMERICAN MID-CONTINENT RIFT SYSTEM, RICE COUNTY, MINNESOTA.

    USGS Publications Warehouse

    Hatch, J.R.; Morey, G.B.

    1985-01-01

    Hydrocarbon source rock evaluation of the Middle Proterozoic Solor Church Formation (Keweenawan Supergroup) as sampled in the Lonsdale 65-1 well, Rice County, shows that: the rocks are organic matter lean; the organic matter is thermally post-mature, probably near the transition between the wet gas phase of catagenesis and metagenesis; and the rocks have minimal potential for producing additional hydrocarbons. The observed thermal maturity of the organic matter requires significantly greater burial depths, a higher geothermal gradient, or both. It is likely, that thermal maturation of the organic matter in the Solor Church took place relatively early, and that any hydrocarbons generated during this early phase were probably lost prior to deposition of the overlying formation.

  3. Effect of increased CO sub 2 and decreased O sub 2 on photosynthesis, and carbon allocation in source leaves

    SciTech Connect

    Fondy, B.R. ); Geiger, D.R.; Shieh, W.-J. )

    1990-05-01

    The effect of raising the rate of photosynthesis on the allocation of carbon between sucrose and starch was studied by means of steady-state radiolabeling. Sugar beet source leaves on intact plants were exposed to ambient levels of CO{sub 2} and O{sub 2} for 3 hrs. Next CO{sub 2} was raised to 600 {mu}LL{sup {minus}3} for 3 hrs then O{sub 2} was decreased to 2% for 3 hrs. Rates of net carbon exchange (NCE), export, and starch and sucrose synthesis were measured. NCER increased by 30% under the combined treatments and the proportion of photosynthate allocated to starch and to sucrose did not change. When O{sub 2} concentration was lowered, NCER increased but export did not and sucrose accumulated. This observation, and our earlier conclusion that export rate usually equals sucrose synthesis rate, lead us to conclude that low O{sub 2} directly inhibited export. Low O{sub 2} treatment causes sucrose to accumulate in a sugar beet leaf which usually accumulates little sucrose.

  4. Source- and region-specific distribution of polycyclic aromatic hydrocarbons in sediments from Jinhae Bay, Korea.

    PubMed

    Yim, Un Hyuk; Hong, Sang Hee; Ha, Sung Yong; Han, Gi Myung; An, Joon Geon; Kim, Nam Sook; Lim, Dhong-Il; Choi, Hyun-Woo; Shim, Won Joon

    2014-02-01

    This study surveyed polycyclic aromatic hydrocarbons (PAHs) at 80 sites in sediment from Jinhae Bay, which consists of Masan Bay (MSB), Haengam Bay (HAB), Bay Proper (JBP), Wonmoon Bay (WMB), and Gohyun Bay (GHB). Levels of the EPA 16 priority PAHs, 5 groups of alkylated PAH homologues and 2 biogenic PAHs were determined. Total PAHs (sum of all target PAHs) ranged from 37.0 ng/g to 3,110 ng/g with a mean of 339 ng/g. WMB had the highest concentration (473 ± 665 ng/g: average ± standard deviation) followed by GHB (214 ± 141 ng/g), MSB (175 ± 358 ng/g), JBP (133 ± 86.0 ng/g) and HAB (118 ± 129 ng/g). A tiered-source identification approach using the pyrogenic index, PAH isomer ratios and alkylated PAH double ratios found that both pyrogenic and petrogenic PAHs were dominant, and identified three different source- and region-specific groups. Input pathway tracers, such as butyltins, nonylphenols and dibenzothiophenes, were used to track the main input pathways. A shipyard and urban runoff were identified as the major input pathways of PAHs into GHB, and urban runoff was identified as a major pathway into MSB and WMB. Used crankcase oil, diesel exhaust, tyre debris and asphalt were considered to be the dominant PAH sources in urban runoff. Several PAH compounds exceeded the interim marine sediment quality guidelines for the protection of aquatic environments, among which dibenz[a,h]anthracene exceeded the guidelines in 16% of surveyed sites. Current PAH levels in MSB indicated an improving situation following the implementation of a total pollutant load management system (TPLMS); this is in accordance with other studies. WMB was recognised as an area of concern within this bay, suggesting the update of the TPLMS in this region.

  5. Characteristics, sources, and cytotoxicity of atmospheric polycyclic aromatic hydrocarbons in urban roadside areas of Hangzhou, China.

    PubMed

    Bai, Hongzhen; Zhang, Hongjian

    2017-03-21

    The primary objective of this study is to understand the profiles, sources and cytotoxic effects of atmospheric polycyclic aromatic hydrocarbons (PAHs), which are closely related to urban air contamination and public health, in urban roadside environments. On-road sampling campaigns were conducted from 2014 to 2015 at three urban road sites in Hangzhou, China. Sixteen gaseous and particulate matter (PM) 2.5-bound PAHs were identified and quantified using gas chromatography-mass spectrometry (GC-MS). The total PAH concentrations at the three sites ranged from 750 to1142 ng/m(3) and 1050 to 1483 ng/m(3) in summer and winter, respectively. Low molecular weight PAHs were the most abundant compounds (77-86%) and primarily existed in gas phase. The concentrations and phase distributions of high molecular weight PAHs were varied at three sites due to the differences in traffic volume, vehicle composition, engine loading, and nearby artificial activity. Diagnostic ratios of the principal mass (m/z,178, 202, 228 and 276) parent PAHs were statistically described to determine the PAH sources to urban roadsides; principal component analysis (PCA) was applied to apportion the sources. The results indicated that high- and low-temperature fuel processes, as well as residential and industrial emissions, were major contributors to roadside PAHs. The cytotoxic potential of the roadside PAHs was evaluated using a human epithelial lung cell line (A549). Cell viability was measured after a direct exposure to PAH extract. The results reflected the profiles of roadside PAHs at the three sites. The cytotoxicity of reference PAHs was evaluated to provide further insights into the cytotoxic potential of PAHs. We found that low molecular weight PAHs, which are less cytotoxic compounds, synergistically promoted the lethal effect of cytotoxic compounds, posing a potential threat to public health.

  6. PAH refractory index as a source discriminant of hydrocarbon input from crude oil and coal in Prince William Sound, Alaska

    USGS Publications Warehouse

    Hostettler, F.D.; Rosenbauer, R.J.; Kvenvolden, K.A.

    1999-01-01

    Geochemical correlation and differentiation of hydrocarbons from crude oils and coals is difficult. The complex mixture of the hydrocarbon constituents and the dynamic nature of these constituents in the environment as they weather contribute to this difficulty A new parameter, the polycyclic aromatic hydrocarbon (PAH) refractory index, is defined here to help in this correlation. The PAH refractory index is a ratio of two of the most refractory constituents of most crude oils, namely triaromatic steranes and monomethylchrysenes. These are among the most persistent compounds in oil after deposition in the environment and thus retain reliably the signature of the original petroleum input. This index is utilized in Prince William Sound (PWS) to differentiate three different oils, as well as to provide evidence that coal, not oil, is the dominant source of the PAHs which are prominent constituents of marine sediments from PWS and the Gulf of Alaska.Geochemical correlation and differentiation of hydrocarbons from crude oils and coals is difficult. The complex mixture of the hydrocarbon constituents and the dynamic nature of these constituents in the environment as they weather contribute to this difficulty. A new parameter, the polycyclic aromatic hydrocarbon (PAH) refractory index, is defined here to help in this correlation. The PAH refractory index is a ratio of two of the most refractory constituents of most crude oils, namely triaromatic steranes and monomethylchrysenes. These are among the most persistent compounds in oil after deposition in the environment and thus retain reliably the signature of the original petroleum input. This index is utilized in Prince William Sound (PWS) to differentiate three different oils, as well as to provide evidence that coal, not oil, is the dominant source of the PAHs which are prominent constituents of marine sediments from PWS and the Gulf of Alaska.

  7. Compounds and methods for the production of long chain hydrocarbons from biological sources

    DOEpatents

    Gordon, John Cameron; Silks, Louis A; Sutton, Andrew D; Wu, Ruilian; Schlaf, Marcel; Waldie, Fraser; West, Ryan; Collias, Dimitris Ioannis

    2016-08-23

    The present invention is directed to the preparation of oxygenated, unsaturated hydrocarbon compounds, such as derivatives of furfural or hydroxymethyl furfural produced by aldol condensation with a ketone or a ketoester, as well as methods of deoxidatively reducing those compounds with hydrogen under acidic conditions to provide saturated hydrocarbons useful as fuels.

  8. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation

    NASA Astrophysics Data System (ADS)

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  9. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation.

    PubMed

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  10. [Vertical distribution and possible sources of polycyclic aromatic hydrocarbon in sewage area soil].

    PubMed

    Yao, Lin-Lin; Zhang, Cai-Xiang; Li, Jia-Le; Liao, Xiao-Ping; Wang, Yan-Xin

    2013-04-01

    Nine profile soil samples were collected from Xiaodian sewage irrigation area, Taiyuan city, China. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography equipped with a mass spectrometry detector (GC/ MS). The rank order of the average concentrations of PAHs in the 0-10 cm upper soil layer was background area < swamp area < groundwater irrigation area < sewage irrigation area. The concentrations of PAHs in most profile soils decreased with the increase of depth, and the PAHs were mainly accumulated in the surface soil layer (0-40 cm). 4-6 rings of PAHs were mainly accumulated in the 0-50 cm soil layer, and the accumulation capacity in groundwater-irrigation area was better than that in sewage irrigation area. The correlation between different rings of PAHs and TOC was positive (r(max) = 0.791, P = 0), and the same situation was found for PAHs and sand (r(max) = 0. 882, P = 0). The correlation between PAHs and pH was negative (r(min) = -0.1, P = 0.702). The main source of PAHs in the surface soil layer (0-40 cm) of study area was coal combustion. There were two pollution ways of PAHs in soil, one was settled into soil directly, the other was first settled into water and absorbed on the surface of solid particles, and then got enrichment in soil as irrigation water flew.

  11. Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution▿

    PubMed Central

    Gomes, Newton C. Marcial; Borges, Ludmila R.; Paranhos, Rodolfo; Pinto, Fernando N.; Krögerrecklenfort, Ellen; Mendonça-Hagler, Leda C. S.; Smalla, Kornelia

    2007-01-01

    Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which had characteristic compositions and levels of PAH compounds in the sediments were selected. The diversity and relative abundance of ndo genes in total community DNA were assessed by a newly developed ndo denaturing gradient gel electrophoresis (DGGE) approach and by PCR amplification with primers targeting ndo genes with subsequent Southern blot hybridization analyses. Bacterial populations inhabiting sediments of urban mangroves under the impact of different sources of PAH contamination harbor distinct ndo genotypes. Sequencing of cloned ndo amplicons comigrating with dominant DGGE bands revealed new ndo genotypes. PCR-Southern blot analysis and ndo DGGE showed that the frequently studied nah and phn genotypes were not detected as dominant ndo types in the mangrove sediments. However, ndo genotypes related to nagAc-like genes were detected, but only in oil-contaminated mangrove sediments. The long-term impact of PAH contamination, together with the specific environmental conditions at each site, may have affected the abundance and diversity of ndo genes in sediments of urban mangroves. PMID:17905873

  12. Historical record and sources of polycyclic aromatic hydrocarbons in core sediments from the Yangtze Estuary, China.

    PubMed

    Liu, M; Baugh, P J; Hutchinson, S M; Yu, L; Xu, S

    2000-11-01

    Polycyclic aromatic hydrocarbons (PAHs) in a sediment core taken from intertidal flat in the Yangtze Estuary were determined by gas chromatography-mass spectrometry. The results indicate that the total concentration of PAHs ranged from 0.08 to 11.74 microg/g. The concentration levels of total and individual PAHs changed dramatically with depth. The concentrations of PAHs were relatively high above 35 cm depth and remained constantly low below this depth. The historical record of PAHs in the core shows subsurface maximum (one or more peak values), followed by decreased levels to the surface and with depth. And, PAH sediment record in the core profile is in agreement with historically sewage discharge events during the 1980s to 1990s. The distribution of target molecule acenephthene, the fluoranthene/pyrene ratio, the proportion of 2-3-ring and 4-5-ring PAHs, and alkylated naphthalene to parent naphthalene in the core profile show that the sources in this area are characterized by petroleum-derived PAH contamination (mainly sewage discharge and the river runoff) and the incorporation of atmospheric inputs. Studies indicate the PAH profile pattern in this site in comparison with other regions appear to reflect its particular local position (near the sewage outlet). Moreover, physico-chemical conditions and sedimentation rate as well as biodegradation also affect the PAH concentration levels in the core sediments.

  13. Geochemical surface anomaly distribution above active hydrocarbon source beds: Anadarko Deep example

    SciTech Connect

    Harnett, R.A.

    1991-08-01

    Surface geochemical surveys were run on all available county roads across the deep part of the Anadarko basin in Caddo, Custer, and Washita Counties, Oklahoma. In the Anadarko Deep there are three major mature petroleum source horizons: Woodford, Springer-Morrow, and Middle-Upper Pennsylvanian marine shales. In most of the area surveyed, the Woodford is post mature. However, the Springer-Morrow and Middle-Upper Pennsylvanian horizons are currently in the oil and/or thermal gas-generating windows. Surface gamma-ray surveys were run over 1,708 mi in T8-9N, R13-19W to see if there were areas of discrete detectable microseep alteration (anomalies) or whether the entire generating area would be without anomalous contrast. Data were analyzed and anomalies were noted. The anomalies were then plotted against the position of major structural elements and drilling results. Discrete areas of anomalies were noted, many coincident with established production. More importantly, large areas were seen to be without anomalies. It is most probable that the detectable microseeps at the surface are associated with gathered concentrations of hydrocarbons at depth since the entire area was not found to be anomalous.

  14. Non-methane hydrocarbons source apportionment at different sites in Mexico City during 2002-2003

    NASA Astrophysics Data System (ADS)

    Vega, E.; Sanchez, G.; Molina, L.

    2007-09-01

    The atmospheric concentrations of a variety of non-methane hydrocarbons (NMHC) collected at different sites, representing urban and rural environments within Mexico City Metropolitan Area (MCMA) during 1997, 2002 and 2003 field campaigns, were compared and used as an input for the Chemical Mass Balance (CMB) receptor model to determine the source contribution of NMHC to the atmosphere. A common feature at all the locations was the dominance of alkenes (59%), aromatics (16%) and olefins (9%) in the average NMHC burden. At the urban sites the interquartile range of NMHC concentrations showed stabilization over this period with a slight increase in the concentrations of propane and butanes in the southwest site of the MCMA in 2003 due to the increased use of liquefied petroleum gas (LPG). The receptor model CMB version 8.0 was used to apportion the NMHC sources at six locations within the MCMA, representing the heavily industrialized, commercial, residential and rural areas. For the 2003 field campaign, the contribution of vehicular emissions dominated the NMHC concentrations (19.7%±7.1% for gasoline vehicles and 35.4%±17.5% for diesel vehicles) followed by the emissions of marketing and handling of LPG (29.9%±8.0%). The NMHC concentrations showed a weekly cycle with the highest levels towards the end of the week and lowest at weekend and beginning of the week, suggesting that both emissions and accumulations process play a key role in building up NMHC levels. The toluene to benzene ratio was used to determine photochemical ageing of the air samples during the 2003 field campaign. The database was divided into periods with similar wind circulation pattern; the results suggest that ageing process within the MCMA is generally suppressed by the amount of fresh emissions.

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

    PubMed

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

    2012-12-01

    Contamination by polycyclic aromatic hydrocarbons (PAHs) of historic wastewater-irrigated agricultural topsoil (0-5 cm) and the contribution of groundwater irrigation and atmospheric deposition to soil PAHs were studied in a typical agricultural region, i.e. Hunpu region, Liaoning, China. Concentrations of total PAHs ranged from 0.43 to 2.64 mg kg⁻¹ in topsoil, being lower than those found in other wastewater-irrigated areas. The levels of PAHs in soil declined as the distance from a water source increased. Concentrations of individual PAHs were generally higher in upland than in paddy topsoils. The calculated nemerow composite index showed that agricultural soil in the region was "polluted" by PAHs. A human health risk assessment based on the total toxic equivalent concentration showed that the presence of elevated concentrations of PAHs in the soil might pose a great threat to the health of local residents. Ratios of pairs of PAHs and principal component analysis (PCA) showed that pyrogenesis, such as coal combustion, was the main source of PAHs, while petroleum, to some extent, also had a strong influence on PAHs contamination in upland soil. The distribution patterns of individual PAHs and composition of PAHs differed between irrigation groundwater and topsoil, but were similar between atmospheric deposition and topsoil. There were significant linear correlations (r = 0.90; p < 0.01) between atmospheric deposition rates and average concentrations of the 16 individual PAHs in soils, while no significant relationships were observed between irrigation groundwater and topsoil in levels of PAHs. These suggested that PAHs in agricultural soils were mainly introduced from atmospheric deposition, rather than from groundwater irrigation after the phasing out of wastewater irrigation in the region since 2002. This study provides a reference to ensure agricultural product safety, pollution control, and proper soil management.

  16. Sources of polycyclic hydrocarbons and pesticides in soluble fraction of deposition samples in Kocaeli, Turkey.

    PubMed

    Binici, Burcu; Yenisoy-Karakaş, Serpil; Bilsel, Mine; Durmaz-Hilmioğlu, Nilüfer

    2014-02-01

    A wet-dry deposition sampler was located at The Scientific and Technological Research Council of Turkey-National Metrology Institute (TUBITAK-UME) station, and a bulk deposition sampler was placed at the Kadıllı village to determine the atmospheric deposition flux of polycyclic aromatic hydrocarbons (PAHs) and pesticides (organochlorine and organophosphorus) in soluble fraction of samples in Kocaeli, Turkey. The 28 samples for each wet, dry, and total deposition were collected weekly from March 2006 to March 2007. Gas chromatography-tandem mass spectrometry was used to analyze the samples which were prepared by using solid-phase extraction (SPE) method. The sum of volume weighted mean of deposition fluxes was obtained as 7.43 μg m(-2) day(-1) for wet deposition, 0.28 μg m(-2) day(-1) for dry deposition and 0.54 μg m(-2) day(-1) for bulk deposition samples for PAHs and 9.88 μg m(-2) day(-1) for wet deposition, 4.49 μg m(-2) day(-1) for dry deposition, and 3.29 μg m(-2) day(-1) for bulk deposition samples for pesticides. While benzo(a)anthracene had the highest fluxes among PAH compounds for all types of depositions, guthion and phosphamidon had the highest deposition flux compared with the other pesticides. Benzo(ghi)perylene, dibenz(a,h)anthracene, indeno(1,2,3-c,d)pyrene, benzo(a)pyrene, and acenaphthene were not detected in any of the samples. Beta-HCH, gamma-HCH, and endrin aldehyde were the only compounds among 18 organochlorine pesticides to be detected in all deposition samples. The main sources of pesticides were the high number of greenhouses around the sampling stations. However, all of the organophosphorus pesticides were detected in all deposition samples. The pollution sources were identified as coal and natural gas combustion, petrogenic sources, and traffic for TUBITAK-UME station whereas coal and natural gas combustion and traffic were the main sources for Kadıllı station by considering the results of factor analysis, ratios, and wind

  17. Seasonal effect and source apportionment of polycyclic aromatic hydrocarbons in PM2.5

    NASA Astrophysics Data System (ADS)

    Khan, Md Firoz; Latif, Mohd Talib; Lim, Chee Hou; Amil, Norhaniza; Jaafar, Shoffian Amin; Dominick, Doreena; Mohd Nadzir, Mohd Shahrul; Sahani, Mazrura; Tahir, Norhayati Mohd

    2015-04-01

    This study aims to investigate distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) bound to fine particulate matter (PM2.5) captured in a semi-urban area in Malaysia during different seasons, and to assess their health risks. PM2.5 samples were collected using a high volume air sampler on quartz filter paper at a flow rate of 1 m3 min-1 for 24 h. PAHs on the filter paper were extracted with dichloromethane (DCM) using an ultrasonic centrifuge solid-phase extraction method and measured by gas chromatography-mass spectroscopy. The results showed that the range of PAHs concentrations in the study period was between 0.21 and 12.08 ng m-3. The concentrations of PAHs were higher during the south-west monsoon (0.21-12.08 ng m-3) compared to the north-east monsoon (0.68-3.80 ng m-3). The high molecular weight (HMW) PAHs (≥5 ring) are significantly prominent (>70%) compared to the low molecular weight (LMW) PAHs (≤4 ring) in PM2.5. The Spearman correlation indicates that the LMW and HMW PAHs correlate strongly among themselves. The diagnostic ratios (DRs) of I[c]P/I[c]P + BgP and B[a]P/B[g]P suggest that the HMW PAHs originated from fuel combustion sources. The source apportionment analysis of PAHs was resolved using DRs-positive matrix factorization (PMF)-multiple linear regression (MLR). The main sources identified were (a) gasoline combustion (65%), (b) diesel and heavy oil combustion (19%) and (c) natural gas and coal burning (15%). The health risk evaluation, by means of the lifetime lung cancer risk (LLCR), showed no potential carcinogenic risk from the airborne BaPeq (which represents total PAHs at the present study area in Malaysia). The seasonal LLCR showed that the carcinogenic risk of total PAHs were two fold higher during south-westerly monsoon compared to north-easterly monsoon.

  18. Hydrocarbon transfer pathways from Smackover source rocks to younger reservoir traps in the Monroe gas field, NE Louisiana

    SciTech Connect

    Zimmerman, R.K. )

    1993-09-01

    The Monroe gas field contained more than 7 tcf of gas in its virgin state. Much of the original gas reserves have been produced through wells penetrating the Upper Cretaceous Monroe Gas Rock Formation reservoir. Other secondary reservoirs in the field area are Eocene Wilcox, the Upper Cretaceous Arkadelphia, Nacatoch, Ozan, Lower Cretaceous, Hosston, Jurassic Schuler, and Smackover. As producing zones, these secondary producing zones reservoirs have contributed an insignificant amount gas to the field. The source of much of this gas appears to have been in the lower part of the Jurassic Smackover Formation. Maturation and migration of the hydrocarbons from a Smackover source into Upper Cretaceous traps was enhanced and helped by igneous activity, and wrench faults/unconformity conduits, respectively. are present in the pre-Paleocene section. Hydrocarbon transfer pathways appear to be more vertically direct in the Jurassic and Lower Cretaceous section than the complex pattern present in the Upper Cretaceous section.

  19. Chemical Formation of Methanol and Hydrocarbon ("Organic") Derivatives from CO2 and H2-Carbon Sources for Subsequent Biological Cell Evolution and Life's Origin.

    PubMed

    Olah, George A; Mathew, Thomas; Prakash, G K Surya

    2017-01-18

    Formation of methanol and hydrocarbon derivatives from CO2 and H2, their simplest molecular building blocks, under biocompatible conditions is proposed. Alternate panspermia of similar extraterrestrially formed and observed hydrocarbons to earth is also discussed. The simple molecular building blocks derived from CO2 and H2 are carbon sources in the initial stage of biological evolution of cells leading to life's origin.

  20. Polycyclic Aromatic Hydrocarbon and Polychlorinated Biphenyl Trends and Source Apportionment in Europe Using Back Trajectories

    NASA Astrophysics Data System (ADS)

    Reimer, E.; Lammel, G.; Jarkovský, J.; Dvorská, A.

    2009-04-01

    Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are classes of organic substances with most of the individual substances being semivolatile and to some degree resisting degradation in the environment (persistent), hence, undergo long-range transport and reach pristine areas in high altitudes and latitudes. PCBs and even more so PAHs pose significant human health hazards in Europe (WHO, 2003). PAHs are emitted especially in incomplete combustion processes in both the gaseous and particulate phases (sorbed to soot). PCBs have been banned from most uses, such that re-emission and volatilization from old urban and industrial materials are prevailing atmospheric sources. As a consequence of fuel, combustion technology and legislative changes sources are changing in strength, substance pattern, and geographic distribution. Monitoring data in air at a central European continental background station, Košetice, Czech Republic, of 1997-2007 (Holoubek et al., 2007) were used in combination with back-trajectories to localize sources of selected PAHs and PCBs in central, western, eastern and southeastern Europe. The trajectory scheme uses the isentropic coordinate with some diabatic components and a special boundary layer modelling (Reimer & Scherer, 1992). Areal contact matrices over Europe are obtained by integration in time of the contacts of the backward trajectories with the ground (1x1 km2 grid) and weighting by the observed concentrations (or fictive concentrations of factors). Positive matrix factorization (Paatero, 1997) was used to infer the substance patterns of the sources (so-called factors) which most significantly contributed to PAH levels at Košetice and a second site, Leipzig, Germany. The interpretation of the results is based on matrices of transport to up to three receptor sites in central Europe. Potential source distributions are presented and discussed. The analysis of air pollution in Košetice in the periods 1997-99 and

  1. [DWT-iPLS applied in the infrared diffuse reflection spectrum of hydrocarbon source rocks].

    PubMed

    Song, Ning; Xu, Xiao-xuan; Wu, Zhong-chen; Zhang, Cun-zhou; Wang, Bin

    2008-08-01

    Infrared spectroscopy is useful to monitor the quality of products on-line, or to quality multivariate properties simultaneously. The IR spectrometer satisfies the requirements of users who want to have quantitative product information in real-time because the instrument provides the information promptly and easily. However, Samples that are measured using diffuse reflectance often exhibit significant differences in the spectra due to the non-homogeneous distribution of the particles. In fact, multiple spectral measurements of the same sample can look completely different. In many cases, the scattering can be an overpowering contributor to the spectrum, sometimes accounting for most of the variance in the data. Although the degree of scattering is dependent on the wavelength of the light that is used and the particle size and refractive index of the sample, the scattering is not uniform throughout the spectrum. Typically, this appears as a baseline shift, tilt and sometimes curvature, where the degree of influence is more pronounced at the longer-wavelength end of the spectrum. The diffuse reflection spectrum is unsatisfactory and the calibration may provide unsatisfactory prediction results. So we must use some methods to remove the effects of the scattering for multivariate calibration of IR spectral signals. Discrete wavelet transform (DWT) is a good method to remove the effects of the scattering for multivariate calibration of IR spectral signals. By using DWT on individual signals as a preprocessing method in regression modeling on IR spectra, good compression is achieved with almost no loss of information, the low-frequency varying background and the high-frequency noise be removed simultaneously. In this report, we use the iPLS method to establish the calibration models of hydrocarbon source rocks. iPLS is a new regression method and the authors can get better results by using DTW- iPLS.

  2. [Size distribution of particle and polycyclic aromatic hydrocarbons in particle emissions from simulated emission sources].

    PubMed

    Fu, Hai-Huan; Tian, Na; Shang, Hui-Bin; Zhang, Bin; Ye, Su-Fen; Chen, Xiao-Qiu; Wu, Shui-Ping

    2014-01-01

    Particles from cooking lampblack, biomass and plastics burning smoke, gasoline vehicular exhausts and gasoline generator exhausts were prepared in a resuspension test chamber and collected using a cascade MOUDI impactor. A total of 18 polycyclic aromatic hydrocarbons (PAHs) associated with particles were analyzed by GC-MS. The results showed that there were two peaks in the range of 0.44-1.0 microm and 2.5-10 microm for cooking lampblack, and only one peak in the range of 0.44-1.0 microm for straw and wood burning smoke. But there were no clear peak for plastics burning smoke. The peak for gasoline vehicular exhausts was found in the range of 2.5-10 microm due to the influence of water vapor associated with particles, while the particles from gasoline generator exhausts were mainly in the range of < or = 2.5 microm (accounting for 93% of the total mass). The peak in 2.5-10 microm was clear for cooking lampblack and gasoline vehicular exhausts. The peak in the range of 0.44-1.0 microm became more and more apparent with the increase of PAHs molecular weight. The fraction of PAH on particles less than 1.0 microm to that on the total particles increased along with PAH's molecular weight. Phenanthrene was the dominant compound for cooking lampblack and combustion smoke, while gasoline vehicular exhausts and generator exhausts were characterized with significantly high levels of naphthalene and benzo[g, h, i] perylene, respectively. The distribution of source characteristic ratios indicated that PAHs from cooking lampblack and biomass burning were close and they were different from those of vehicular exhausts and generator exhausts.

  3. Background concentrations and source apportionment of polycyclic aromatic hydrocarbons in south-eastern Finland

    NASA Astrophysics Data System (ADS)

    Vestenius, Mika; Leppänen, Sirkka; Anttila, Pia; Kyllönen, Katriina; Hatakka, Juha; Hellén, Heidi; Hyvärinen, Antti-Pekka; Hakola, Hannele

    2011-07-01

    Polycyclic aromatic hydrocarbons (PAH compounds) were measured in the PM 10 fraction [from ambient air] at Virolahti, Finland. The sampling site is located in a rural area in the south-eastern corner of Finland, near the Russian border. Altogether, 51 daily and 85 weekly filter samples were collected in 2007-2008. The yearly average concentration of benzo(a)pyrene at Virolahti in 2007 was 0.21 ng m -3, which is well below the annual target value of 1 ng m -3 set by the European Union. The positive matrix factorization (PMF) method was applied in source apportionment for daily PAH data combined with other pollutant data. A three-factor solution of the PMF analysis with 28 components was chosen. These three factors were identified as long-range transported secondary particles (F1), combustion (F2) and a sea-salt factor (F3). The conditional probability function (CPF) was used to combine wind direction sectors with the PMF factors. In cases F1 and F2, pollutants mainly originated from the south-east, whereas pollutants in F3 came from the south-western sector. PAHs entered into the combustion factor 2 together with SO 2, NO x, black carbon and potassium. This suggests that the PAHs at Virolahti originated from traffic and industrial pollution, as well as biomass burning. Elevated concentrations occurred throughout the winter period and most frequently originated from the south-eastern sector between 90°-135°. This sector includes, among other transboundary areas, the metropolis of St. Petersburg at a distance of 160 km.

  4. Sources and Transport of Particulate Hydrocarbons in the Meso-tidal Changjiang Estuary

    NASA Astrophysics Data System (ADS)

    Sicre, M.-A.; Broyelle, I.; Lorre, A.; Saliot, A.

    1993-12-01

    n-Alkanes and polyaromatic hydrocarbons (PAHs) were analysed on suspended particles from surface waters of the Changjiang Estuary to assess the sources and fate of river-borne material in a meso-tidal riverine system. The n -alkane and PAH assemblages indicated prevailing terrestrial and anthropogenic inputs. Measurements performed at several stations within the estuary showed lower concentrations in the North than in the South Channel. These observations were in agreement with the dynamics and flow pattern of the Changjiang in this part of the estuary. Concentrations measured at a tidal series station over two tidal cycles exhibited a significant increase in flooding of more saline waters. Total suspended particles were also higher, reaching their maximum value (1·9 g l -1) at high tide during the first flood. These findings were attributed to the landwards transport of the turbidity maximum zone from the outer estuary, as the Taiwan Warm Current funnels into the Changjiang River mouth. Saltier and less turbid waters with a more pronounced marine character could reach the tidal series site at the final stage of the second flood. During the ebb, suspended n-alkane and PAH concentrations were lower but their compositional features remained similar to those during the flood. A high total suspended particle concentration was observed during the ebb, presumably due to the Huang Pu waters flushing. The n -alkane and PAH content of the particles during such an event pointed out stronger contamination of the waters after crossing the highly populated and industrialized area of Shanghai. Flux calculations based on current meter data indicated significant differences between flood and ebb transports.

  5. Modified ion source triple quadrupole mass spectrometer gas chromatograph for polycyclic aromatic hydrocarbon analyses

    PubMed Central

    Anderson, Kim A.; Szelewski, Michael J.; Wilson, Glenn; Quimby, Bruce D.; Hoffman, Peter D.

    2015-01-01

    We describe modified gas chromatography electron-impact/triple-quadrupole mass spectrometry (GC–EI/MS/MS) utilizing a newly developed hydrogen-injected self-cleaning ion source and modified 9 mm extractor lens. This instrument, with optimized parameters, achieves quantitative separation of 62 polycyclic aromatic hydrocarbons (PAHs). Existing methods historically limited rigorous identification and quantification to a small subset, such as the 16 PAHs the US EPA has defined as priority pollutants. Without the critical source and extractor lens modifications, the off-the-shelf GC–EI/MS/MS system was unsuitable for complex PAH analysis. Separations were enhanced by increased gas flow, a complex GC temperature profile incorporating multiple isothermal periods, specific ramp rates, and a PAH-optimized column. Typical determinations with our refined GC–EI/MS/MS have a large linear range of 1–10,000 pg μl−1 and detection limits of <2 pg μl−1. Included in the 62 PAHs, multiple-reaction-monitoring (MRM) mode enabled GC-EI/MS/MS identification and quantitation of several constituents of the MW 302 PAHs isomers. Using calibration standards, values determined were within 5% of true values over many months. Standard curve r2 values were typically >0.998, exceptional for compounds which are archetypally difficult. With this method benzo[a]fluorene, benzo[b]fluorene, benzo[c]fluorene were fully separated as was benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[j]fluoranthene. Chrysene and triphenylene, were sufficiently separated to allow accurate quantitation. Mean limits of detection (LODs) across all PAHs were 1.02 ± 0.84 pg μl−1 with indeno[1,2,3-c,d] pyrene having the lowest LOD at 0.26 pg μl−1 and only two analytes above 2.0 pg μl−1; acenaphthalene (2.33 pg μl−1) and dibenzo[a,e]pyrene (6.44 pg μl−1). PMID:26454790

  6. 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

  7. Polycyclic aromatic hydrocarbons in soils of the central Tibetan Plateau, China: Distribution, sources, transport and contribution in global cycling.

    PubMed

    Yuan, Guo-Li; Wu, Li-Juan; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

    2015-08-01

    Forty-four soil samples were collected across the central Tibetan Plateau (CTP) at altitudes between 3711 m and 5352 m, and their polycyclic aromatic hydrocarbons (PAHs) contents were measured to be from 0.43 to 26.66 ng/g. The main sources of PAHs were identified for each of four sub-areas, and their concentrations in soils were determined to be mainly influenced by local sources. Along a 600 km sampling trajectory from Lhasa, which served as the biggest local source, the concentrations of PAHs decreased logarithmically with increasing distances from the source. Meanwhile, the fractional proportions of PAHs were observed to change logarithmically according to the transport distances. Conclusively, PAHs from local sources were transported within the CTP and dominated PAHs concentrations in the soils, but few of them were transported outside the CTP. In global cycling, the soils in the CTP mainly serve as background and a "sink" for PAHs.

  8. Patterns and sources of particle-phase aliphatic and polycyclic aromatic hydrocarbons in urban and rural sites of western Greece

    NASA Astrophysics Data System (ADS)

    Kalaitzoglou, Maria; Terzi, Eleni; Samara, Constantini

    Particle-bound aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs, respectively) were determined in the ambient air of the Eordea basin, in western Greece, where intensive coal burning for power generation takes place. Thirteen PAHs, n-alkanes (C 14-C 35), hopanes, and isoprenoid hydrocarbons (pristane and phytane) were determined in the total suspended particles collected from the atmosphere of four sites within the basin receiving potential impacts from various sources, such as fly ash, coal mining, automobile traffic, domestic heating, and agricultural or refuse burning. The same organic species were also determined in the fly ash generated in power stations, and in particulate emissions from open burning of biomass (dry corn leaves) and refuse burning. Organic particle sources were resolved using concentration diagnostic ratios and factor analysis (FA). A multivariate statistical receptor model (Absolute Principal Component Analysis, APCA) was finally employed to estimate the contribution of identified sources to the measured concentrations of organic pollutants. Four major sources for ambient PAHs and AHs were identified displaying variable contribution in different sites: (a) fossil fuel combustion, (b) biogenic emissions, (c) refuse burning, and (d) oil residues. Fuel combustion was the major source of ambient PAHs and an important source of n-alkanes in the range C 21-C 28. Oil residues were found to be the major source of low molecular weight n-alkanes (particularly the C 14-C 16), and an important source of pristane, phytane and UCM. Biogenic sources were primarily responsible for the high molecular weight n-alkanes explaining almost the entire concentration levels of homologues >C 32. Biomass burning was particularly important for the C 23-C 26n-alkanes. Despite the vicinity of certain sampling sites to power stations, coal fly ash was not identifiable as a source for ambient PAHs and AHs.

  9. Field-scale investigation of enhanced petroleum hydrocarbon biodegradation in the vadose zone combining soil venting as an oxygen source with moisture and nutrient addition. Appendices. Doctoral thesis

    SciTech Connect

    Miller, R.N.

    1990-01-01

    This document contains appendices regarding a reprint on a field scale investigation of enhanced petroleum hydrocarbon biodegradation in the vadose zone combining soil venting as a oxygen source with moisture and nutrient addition.

  10. A suggestion to assess spilled hydrocarbons as a greenhouse gas source

    SciTech Connect

    McAlexander, Benjamin L.

    2014-11-15

    Petroleum-contaminated site management typically counts destruction of hydrocarbons by either natural or engineered processes as a beneficial component of remediation. While such oxidation of spilled hydrocarbons is often necessary for achieving risk reduction for nearby human and ecological receptors, site assessments tend to neglect that this also means that the pollutants are converted to greenhouse gases and emitted to the atmosphere. This article presents a suggestion that the current and long term greenhouse gas emissions from spilled hydrocarbons be incorporated to petroleum site assessments. This would provide a more complete picture of pollutant effects that could then be incorporated to remedial objectives. At some sites, this additional information may affect remedy selection. Possible examples include a shift in emphasis to remedial technologies that reduce pollutant greenhouse gas effects (e.g., by conversion of methane to carbon dioxide in the subsurface), and a more holistic context for considering remedial technologies with low emission footprints.

  11. Emergency Department Visit Forecasting and Dynamic Nursing Staff Allocation Using Machine Learning Techniques With Readily Available Open-Source Software.

    PubMed

    Zlotnik, Alexander; Gallardo-Antolín, Ascensión; Cuchí Alfaro, Miguel; Pérez Pérez, María Carmen; Montero Martínez, Juan Manuel

    2015-08-01

    Although emergency department visit forecasting can be of use for nurse staff planning, previous research has focused on models that lacked sufficient resolution and realistic error metrics for these predictions to be applied in practice. Using data from a 1100-bed specialized care hospital with 553,000 patients assigned to its healthcare area, forecasts with different prediction horizons, from 2 to 24 weeks ahead, with an 8-hour granularity, using support vector regression, M5P, and stratified average time-series models were generated with an open-source software package. As overstaffing and understaffing errors have different implications, error metrics and potential personnel monetary savings were calculated with a custom validation scheme, which simulated subsequent generation of predictions during a 4-year period. Results were then compared with a generalized estimating equation regression. Support vector regression and M5P models were found to be superior to the stratified average model with a 95% confidence interval. Our findings suggest that medium and severe understaffing situations could be reduced in more than an order of magnitude and average yearly savings of up to €683,500 could be achieved if dynamic nursing staff allocation was performed with support vector regression instead of the static staffing levels currently in use.

  12. Fungal nutrient allocation in common mycorrhizal networks is regulated by the carbon source strength of individual host plants.

    PubMed

    Fellbaum, Carl R; Mensah, Jerry A; Cloos, Adam J; Strahan, Gary E; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2014-07-01

    Common mycorrhizal networks (CMNs) of arbuscular mycorrhizal (AM) fungi in the soil simultaneously provide multiple host plants with nutrients, but the mechanisms by which the nutrient transport to individual host plants within one CMN is controlled are unknown. Using radioactive and stable isotopes, we followed the transport of phosphorus (P) and nitrogen (N) in the CMNs of two fungal species to plants that differed in their carbon (C) source strength, and correlated the transport to the expression of mycorrhiza-inducible plant P (MtPt4) and ammonium (1723.m00046) transporters in mycorrhizal roots. AM fungi discriminated between host plants that shared a CMN and preferentially allocated nutrients to high-quality (nonshaded) hosts. However, the fungus also supplied low-quality (shaded) hosts with nutrients and maintained a high colonization rate in these plants. Fungal P transport was correlated to the expression of MtPt4. The expression of the putative ammonium transporter 1723.m00046 was dependent on the fungal nutrient supply and was induced when the CMN had access to N. Biological market theory has emerged as a tool with which the strategic investment of competing partners in trading networks can be studied. Our work demonstrates how fungal partners are able to retain bargaining power, despite being obligately dependent on their hosts.

  13. Polycyclic aromatic hydrocarbon sources related to biomarker levels in fish from Prince William Sound and the Gulf of Alaska.

    PubMed

    Page, David S; Huggett, Robert J; Stegeman, John J; Parker, Keith R; Woodin, Bruce; Brown, John S; Bence, A Edward

    2004-10-01

    Seafloor sediments in Prince William Sound (PWS) and the eastern Gulf of Alaska (GOA) have a substantial regional hydrocarbon background from natural sources including oil seeps and eroding sedimentary rocks along the eastern GOA coast. Polycyclic aromatic hydrocarbons (PAH) from that background appear to be bioavailable to fish. Fish collected from PWS and the GOA in a 1999--2000 biomarker study (bile fluorescent aromatic contaminants and liver ethoxyresorufin O-deethylase) show evidence of exposure to low levels of PAH at all categories of sites sampled. Seafloor sediments at fish sampling sites in the GOA east of PWS and at three PWS site categories (nonspill path, spill path oiled, and spill path not oiled) contain hydrocarbons from four principal sources: regional background, combustion products, residues from the 1989 Exxon Valdez oil spill (EVOS), and Monterey (CA) petroleum residues. GOA sediments between PWS and Yakutat Bay, approximately 350 km to the east, are dominated by regional petrogenic background hydrocarbons (total PAH (TPAH) range approximately 60-3400 ng/g) that are the probable cause of low biomarker levels measured in halibut from this area. PWS sediments contain varying proportions of regional background, combustion products, Monterey residues, and EVOS residues at some spill path sites. Rockfish caught in PWS embayments in 1999 have liver EROD activities that correlate positively with the pyrogenic PAH indicator ratio (FI+Py)/C24Ph. Although traces (<5-100 ng/g TPAH) of EVOS residues were detected in seafloor sediments at some nearshore spill path sites, biomarker levels in fish from those sites are not elevated relative to other sites in PWS.

  14. Pore-space alteration in source rock (shales) during hydrocarbons generation: laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.; Nadezhkin, D. V.

    2013-12-01

    Hydrocarbons (HC) are generated from solid organic matter (kerogen) due to thermocatalytic reactions. The rate of such reactions shows direct correlation with temperature and depends on the depth of source rock burial. Burial of sedimentary rock is also inevitably accompanied by its structural alteration owing to compaction, dehydration and re-crystallization. Processes of HC generation, primary migration and structural changes are inaccessible for direct observation in nature, but they can be studied in laboratory experiments. Experiment was carried out with a clayey-carbonate rock sample of the Domanik Horizon taken from boreholes drilled in the northeastern part of the south Tatar arch. The rock chosen fits the very essential requirements - high organic matter content and its low metamorphic grade. Our work aimed at laboratory modeling of HC generation in an undisturbed rock sample by its heating in nitrogen atmosphere based on a specified temperature regime and monitoring alterations in the pore space structure. Observations were carried out with a SkyScan-1172 X-ray microtomography scanner (resulting scan resolution of 1 μm). A cylinder, 44 mm in diameter, was prepared from the rock sample for the pyrolitic and microtomographic analyses. Scanning procedures were carried out in 5 runs. Temperature interval for each run had to match the most important stage of HC generation in the source rock, namely: (1) original structure; (2) 100-300°C - discharge of free and adsorbed HC and water; (3) 300-400°C - initial stage of HC formation owing to high-temperature pyrolysis of the solid organic matter and discharge of the chemically bound water; (4) 400-470°C - temperature interval fitting the most intense stage of HC formation; (5) 470-510°C - final stage of HC formation. Maximum sample heating in the experiment was determined as temperature of the onset of active decomposition of carbonates, i.e., in essence, irreversible metamorphism of the rock. Additional

  15. Development of a web GIS application for emissions inventory spatial allocation based on open source software tools

    NASA Astrophysics Data System (ADS)

    Gkatzoflias, Dimitrios; Mellios, Giorgos; Samaras, Zissis

    2013-03-01

    Combining emission inventory methods and geographic information systems (GIS) remains a key issue for environmental modelling and management purposes. This paper examines the development of a web GIS application as part of an emission inventory system that produces maps and files with spatial allocated emissions in a grid format. The study is not confined in the maps produced but also presents the features and capabilities of a web application that can be used by every user even without any prior knowledge of the GIS field. The development of the application was based on open source software tools such as MapServer for the GIS functions, PostgreSQL and PostGIS for the data management and HTML, PHP and JavaScript as programming languages. In addition, background processes are used in an innovative manner to handle the time consuming and computational costly procedures of the application. Furthermore, a web map service was created to provide maps to other clients such as the Google Maps API v3 that is used as part of the user interface. The output of the application includes maps in vector and raster format, maps with temporal resolution on daily and hourly basis, grid files that can be used by air quality management systems and grid files consistent with the European Monitoring and Evaluation Programme Grid. Although the system was developed and validated for the Republic of Cyprus covering a remarkable wide range of pollutant and emissions sources, it can be easily customized for use in other countries or smaller areas, as long as geospatial and activity data are available.

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

    EPA Science Inventory

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

  17. Level, potential sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in Naples

    NASA Astrophysics Data System (ADS)

    Di Vaio, Paola; Cocozziello, Beatrice; Corvino, Angela; Fiorino, Ferdinando; Frecentese, Francesco; Magli, Elisa; Onorati, Giuseppe; Saccone, Irene; Santagada, Vincenzo; Settimo, Gaetano; Severino, Beatrice; Perissutti, Elisa

    2016-03-01

    In Naples, particulate matter PM10 associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined in urban background (NA01) and urban traffic (NA02) sites. The principal objective of the study was to determine the concentration and distribution of PAHs in PM10 for identification of their possible sources (through diagnostic ratio - DR and principal component analysis - PCA) and an estimation of the human health risk (from exposure to airborne TEQ). Airborne PM10 samples were collected on quartz filters using a Low Volume Sampler (LVS) for 24 h with seasonal samples (autumn, winter, spring and summer) of about 15 days each between October 2012 and July 2013. The PM10 mass was gravimetrically determined. The PM10 levels, in all seasons, were significantly higher (P < 0.001) in the urban-traffic site (NA02) than in the urban-background site (NA01). The filters were then extracted with dichloromethane using an ultrasonicator (SONICA) to perform a detailed characterization of 12 priority PAHs proposed by the USEPA, by gas chromatography-mass spectrometer (GC-MS) analysis. The concentration of Benzo[a]Pyrene, BaP (EU and National limit value: 1 ng m-3 in PM10), varied from 0.065 ng m-3 during autumn time to 0.872 ng m-3 in spring time (NA01) and from 0.120 ng m-3 during autumn time to 1.48 ng m-3 of winter time (NA02) with four overshoots. In NA02 the trend of Σ12 PAHs was comparable to NA01 but were observed higher values than NA01. In fact, the mean concentration of Σ12 PAHs, in urban-traffic site was generally 2 times greater than in urban-background site in all the campaigns. PAHs with 5 and 6 ring, many of which are suspected carcinogens or genotoxic agents, (i.e Benzo[a]Pyrene, Indeno[1,2,3-cd]Pyrene, Benzo[b]Fluoranthene, Benzo[k]Fluoranthene and Benzo[g,h,i]Perylene), had a large contribution (∼50-55%) of total PAHs concentration in PM10 in two sites and in each of the campaigns. Diagnostic ratio analysis and PCA suggested a

  18. The dynamic of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-02-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will condition the response of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study is to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). Combining field measurements and process-based simulations at 49 sites (931 site-years), we assessed the stand biomass growth dependences at both inter-site and inter-annual scales. Specifically, the relative influence of forest C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in stand C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual stand woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. We provide an evaluation of the spatio-temporal dynamics of annual carbon allocation to wood in European forests. Our study supports the premise that European forest growth is under a complex control including both source and sink limitations. The relative influences of the different growth drivers strongly vary across years and spatial ecological gradients. We suggest a

  19. Carbon allocation, source-sink relations and plant growth: do we need to revise our carbon centric concepts?

    NASA Astrophysics Data System (ADS)

    Körner, Christian

    2014-05-01

    Since the discovery that plants 'eat air' 215 years ago, carbon supply was considered the largely unquestioned top driver of plant growth. The ease at which CO2 uptake (C source activity) can be measured, and the elegant algorithms that describe the responses of photosynthesis to light, temperature and CO2 concentration, explain why carbon driven growth and productivity became the starting point of all process based vegetation models. Most of these models, nowadays adopt other environmental drivers, such as nutrient availability, as modulating co-controls, but the carbon priority is retained. Yet, if we believe in the basic rules of stoichometry of all life, there is an inevitable need of 25-30 elements other then carbon, oxygen and hydrogen to build a healthy plant body. Plants compete for most of these elements, and their availability (except for N) is finite per unit land area. Hence, by pure plausibility, it is a highly unlikely situation that carbon plays the rate limiting role of growth under natural conditions, except in deep shade or on exceptionally fertile soils. Furthermore, water shortage and low temperature, both act directly upon tissue formation (meristems) long before photosynthetic limitations come into play. Hence, plants will incorporate C only to the extent other environmental drivers permit. In the case of nutrients and mature ecosystems, this sink control of plant growth may be masked in the short term by a tight, almost closed nutrient cycle or by widening the C to other element ratio. Because source and sink activity must match in the long term, it is not possible to identify the hierarchy of growth controls without manipulating the environment. Dry matter allocation to C rich structures and reserves may provide some stoichimetric leeway or periodic escapes from the more fundamental, long-term environmental controls of growth and productivity. I will explain why carbon centric explanations of growth are limited or arrive at plausible answers

  20. The source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the topsoil in Xiaodian sewage irrigation area, North of China.

    PubMed

    Li, Jia-Le; Wang, Yan-Xin; Zhang, Cai-Xiang; Dong, Yi-Hui; Du, Bin; Liao, Xiao-Ping

    2014-12-01

    31 topsoil samples were collected by grid method in Xiaodian sewage irrigation area, Taiyuan City, North of China. The concentrations of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatograph coupled with mass spectrum. Generally speaking, the distribution order of PAHs in the area is: those with five and six rings > those with four rings > those with two and three rings. Source apportionment shows a significant zonation of the source of PAHs: the civil coal pollution occurred in the north part, the local and far factory pollution happened in the middle area and the mixed pollution sources from coal and wood combustion, automotive emission, presented in the south area. The distribution of PAHs has a definite relationship with the sewage water flow and soil adsorption. The related coefficient between PAHs and physicochemical property showed there was a negative correlation between pH, silt, clay and PAHs while there was a positive correlation between total organic carbon, sand and PAHs.

  1. Hydrocarbons in sediments along a tropical estuary-shelf transition area: Sources and spatial distribution.

    PubMed

    Maciel, Daniele Claudino; de Souza, José Roberto Botelho; Taniguchi, Satie; Bícego, Márcia Caruso; Schettini, Carlos Augusto França; Zanardi-Lamardo, Eliete

    2016-12-15

    Estuaries generally act as sediment traps and may retain a range of contaminants associated to this matrix. Aliphatic hydrocarbons (AHs) were investigated in Capibaribe Estuarine System and adjacent shelf, Northeast of Brazil, to evaluate the contamination and to better understand its functionality related to the coast. Fourteen sediment samples were analyzed, using gas chromatography with flame ionization detection. Total AHs concentrations ranged from 7.5 to 190.3μgg(-1) and n-alkanes ranged from below detection limit (hydrocarbons. The concentration decrease (about 90%) towards the adjacent shelf suggested an estuarine high retention capacity but dilution and degradation processes cannot be neglected. Similar AHs characteristics reported in sediments from the adjacent shelf suggested that this system may also export contaminants.

  2. Environmental Hydrocarbon Harvesting for Micro-Scale Power Sources using Thermopower Waves

    DTIC Science & Technology

    2015-04-06

    AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Department of Chemical ...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Department of Chemical Engineering, Massachusetts Institute of Technology Room 66-570B, 77 Massachusetts...enabling hydrocarbon energy harvesting in a novel pulsed reactor design. 4) We have studied the scaling of thermopower wave devices to gain more

  3. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in ambient air of an industrial region in Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Yagmur Meltem; Kara, Melik; Dumanoglu, Yetkin; Odabasi, Mustafa; Elbir, Tolga

    2014-11-01

    Source apportionment is generally applied to a time series of data collected at a single site. However, in a complex airshed containing several different sources, it may be helpful to collect samples from multiple sites to ensure that some of them have low contributions from specific sources, thus the boundaries can be properly defined. Ambient air polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyls (PCB) samples (n = 160) were collected at 40 sites during four seasons (summer, fall, winter, and spring) between July 2009 and April 2010 in the heavily industrialized Aliaga region in Turkey to investigate their spatial, seasonal variations and to identify possible PAH and PCB sources. The newest version of EPA PMF (V5.0) having the capability of handling multiple site data was used for source apportionment. Five PAH sources were identified as biomass and coal combustion, iron-steel production, unburned crude oil and petroleum products, and diesel and gasoline exhaust emissions with contributions of 40, 27, 27, 3, and 3%, respectively. The sources of PCBs were identified as iron-steel production (consisting of steel-making and ship breaking activities), coal and wood combustion, and evaporative emissions from technical PCB mixtures with contributions of 57, 31, and 12%, respectively.

  4. Source identification of polycyclic aromatic hydrocarbons in different ecological wetland components of the Qinkenpao Wetland in Northeast China.

    PubMed

    Zhang, Yonggen; Liu, Mingzhu; Chen, Honghan; Hou, Guohua

    2014-04-01

    To determine the distribution and sources of polycyclic aromatic hydrocarbon (PAH), sixteen common PAHs were measured in various wetland components, including groundwater, surface water, sediments and soils collected from the Qinkenpao Wetland of Daqing City in Northeast China. High levels of PAHs were observed in the wetland due to the discharge of industrial wastewater including petrochemical products, such as petroleum and carbolic acid, which can be traced back for nearly three decades. Diagnostic ratios of selected PAH compounds showed that PAHs were generated by a number of mixed sources dominated by petrogenic products. Factor analysis with nonnegative constraints (FA-NNC) was combined with Latin Hypercube Sampling (LHS) simulation, which is effective for using a relatively small sample size while preserving the desirable probabilistic features of simple random sampling, to quantitatively identify sources, source contribution, and uncertainty of PAH contamination. The profiles derived from FA-NNC coupled with LHS were compared with source fingerprints, which were modified based on the first order degradation reaction in different wetland components. Premium gasoline (high-octane) was found to be the largest contributor of PAHs in surface water, groundwater, and sediments (96.0 percent, 61.6 percent and 53.1 percent, correspondingly), while regular gasoline was the dominant source of PAHs in soils (49.0 percent). The results were in agreement with the area׳s environmental data and diagnostic ratio results. Diagnostic ratios and FA-NNC were shown to be an effective methodology for source identification of PAHs in different wetland components.

  5. Identification of hydrocarbon sources in the benthic sediments of Prince William Sound and the Gulf of Alaska following the Exxon Valdez oil spill

    SciTech Connect

    Page, D.S.; Boehm, P.D.; Douglas, G.S.; Bence, A.E.

    1995-12-31

    Advanced hydrocarbon fingerprinting methods and improved analytical methods make possible the quantitative discrimination of the multiple sources of hydrocarbons in the benthic sediments of Prince William Sound (PWS) and the Gulf of Alaska. These methods measure an extensive range of polycyclic aromatic hydrocarbons (PAH) at detection levels that are as much as two orders of magnitude lower than those obtained by standard Environmental Protection Agency methods. Nineteen hundred thirty six subtidal sediment samples collected in the sound and the eastern Gulf of Alaska in 1989, 1990, and 1991 were analyzed. Fingerprint analyses of gas chromatography-mass spectrometry data reveal a natural background of petrogenic and biogenic PAH. Exxon Valdez crude, its weathering products, and diesel fuel refined from Alaska North Slope crude are readily distinguished from the natural seep petroleum background and from each other because of their distinctive PAH distributions. Mixing models were developed to calculate the PAH contributions from each source to each sediment sample. These calculations show that most of the seafloor in PWS contains no detectable hydrocarbons from the Exxon Valdez spill, although elevated concentrations of PAH from seep sources are widespread. In those areas where they were detected, spill hydrocarbons were generally a small increment to the natural petroleum hydrocarbon background. Low levels of Exxon Valdez crude residue were present in 1989 and again in 1990 in nearshore subtidal sediments off some shorelines that had been heavily oiled. By 1991 these crude residues were heavily degraded and even more sporadically distributed. 58 refs., 18 figs., 5 tabs.

  6. Numerical modelling on fate and transport of petroleum hydrocarbons in an unsaturated subsurface system for varying source scenario

    NASA Astrophysics Data System (ADS)

    Berlin, M.; Vasudevan, M.; Kumar, G. Suresh; Nambi, Indumathi M.

    2015-04-01

    The vertical transport of petroleum hydrocarbons from a surface spill through an unsaturated subsurface system is of major concern in assessing the vulnerability of groundwater contamination. A realistic representation on fate and transport of volatile organic compounds at different periods after spill is quite challenging due to the variation in the source behaviour at the surface of spill as well as the variation in the hydrodynamic parameters and the associated inter-phase partitioning coefficients within the subsurface. In the present study, a one dimensional numerical model is developed to simulate the transport of benzene in an unsaturated subsurface system considering the effect of volatilization, dissolution, adsorption and microbial degradation of benzene for (i) constant continuous source, (ii) continuous decaying source, and (iii) residual source. The numerical results suggest that volatilization is the important sink for contaminant removal considering the soil air migration within the unsaturated zone. It is also observed that the coupled effect of dissolution and volatilization is important for the decaying source at the surface immediately after the spill, whereas rate-limited dissolution from residually entrapped source is responsible for the extended contamination towards later period.

  7. Radiocarbon apportionment of fossil versus biofuel combustion sources of polycyclic aromatic hydrocarbons in the Stockholm metropolitan area.

    PubMed

    Mandalakis, Manolis; Gustafsson, Orjan; Reddy, Christopher M; Xu, Li

    2004-10-15

    Source-diagnostic markers and the isotopic composition of polycyclic aromatic hydrocarbons (PAHs) were examined in surface sediments from the greater Stockholm waterways to deduce the contribution from biomass sources to the environmental PAH load. The summed concentration of 20 PAHs ranged from 0.8 to 45.1 microg/g (dry weight) and exhibited a steep decline with increasing distance from the city center evidencing that sources within the metropolitan area of Stockholm dominate its PAH burden. Several diagnostic PAH ratios indicated an overwhelming predominance of pyrogenic sources over the petrogenic ones, while retene and 1,7-dimethylphenanthrene were unable to correctly evaluate the contribution from biomass combustion. The stable carbon isotope composition (delta13C) of individual PAHs ranged from -24.8 to -27.0% but also was proved inefficient to discriminate between different types of fuels due to the overlapping signals in various sources. The delta14C values of PAHs ranged between -550.4 and -934.1%, indicating a clear predominance of fossil fuel sources. By using an isotopic mass balance approach, we estimated that on average 17+/-9% of PAHs derived from biomass combustion. This radiocarbon apportionment, in conjunction with detailed energy statistics for the Stockholm region, revealed that the ambient PAH burden is roughly similar, per unit energy produced, from fossil fuels and biofuels. Societies' shifting energy policies toward a larger reliance on biofuels may thus not lead to further deterioration of air quality and respiratory ailments for the urban population.

  8. Determination of the Sources of Chlorinated Hydrocarbons Detected During MSL Missions

    NASA Astrophysics Data System (ADS)

    Buch, Arnaud; Belmahdi, Imène; Szopa, Cyril; Freissinet, Caroline; Glavin, Danny P.; Miller, Kirsten; Summons, Roger; Francois, Pascaline; Coll, Patrice; Eigenbrode, Jennifer; Teinturier, Samuel; Navarro-Gonzalez, Rafael; Stern, Jennifer; McAdam, Amy; Dequaire, Tristan; Millan, Maeva; Bonnet, Jean Yves; Coscia, David; Cabane, Michel; Mahaffy, Paul

    2015-04-01

    Sample Analysis at Mars (SAM) is one of the instruments of the MSL mission. Three analytical instruments composed SAM: the Tunable Laser Spectrometer (TLS), the Gas Chromatography (GC) and the Mass Spectrometer (QMS). It includes a sample preparation and gas processing system implemented with a pyrolysis system, wet chemistry (MTBSTFA and TMAH) and the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G), employed to concentrate volatiles released from the sample prior to GC-MS analysis [1]. This study investigates several propositions for chlorinated hydrocarbon formation, detected by SAM. Here we report on the detection of chlorohydrocarbon compounds and their potential origin. To date, SAM has detected a range of diverse chlorinated hydrocarbons from GCMS analysis of samples collected at the several locations explored by Curiosity (Rocknest, John Klein, Cumberland and Confidence Hill). Some of these chlorohydrocarbons are produced during pyrolysis by the reaction of Martian oxychlorine compounds in the samples with terrestrial carbon from a derivatization agent (MTBSTFA) present in SAM [2, 3]. Chlorobenzene cannot be formed by the reaction of MTBSTFA and perchlorates (2) and two other reaction pathways were therefore proposed : (i) reactions between the volatile thermal degradation products of perchlorates (e.g. O2, Cl2 and HCl) and Tenax® and (ii) the interaction of perchlorates (T > 200 °C) with OM from Martian soil such as benzenecarboxylates [4, 5]. References: 1. P. R. Mahaffy et al. (2012) Space Sci. Rev. 170, 401-478. 2. D. P. Glavin et al.(2013) JGR 118, 1955-1973. 3. L. a Leshin et al. (2013) Science 341, 1238937. 4. C. Freissinet et al. (2014) LPSC XXXXV Abstract 2796. 5. H. Steininger et al. (2012) Planet. Space Sci. 71, 9-17.

  9. Polycyclic aromatic hydrocarbons in surface sediments from the Coast of Weihai, China: Spatial distribution, sources and ecotoxicological risks.

    PubMed

    Zhang, Daolai; Liu, Jinqing; Yin, Ping; Lin, Xuehui; Liu, Na; Meng, Xianwei

    2016-08-15

    This study was conducted to measure the polycyclic aromatic hydrocarbon (PAH) concentrations and evaluate the distribution, sources in surface sediments from various coastal sites in Weihai, which create good conditions for rapid development because of their excellent geographical location and abundant marine resources. The results indicated that the total PAHs contents in the sediments of Weihai ranged from 2.69 to 166.50ngg(-1), with an average of 67.44ngg(-1). Phenanthrene, Fluoranthene, Benzo(b)fluoranthene, Chrysene, and Pyrene were dominant in sediments, primarily as a result of high temperature combustion and biomass. Molecular ratios suggested that these PAHs in the sediments of Weihai were predominantly from pyrogenic sources such as grass, wood and charcoal combustion, as well as engine exhaust which is similar to the result of the study of the Yellow River Delta, China. The result of probability risk assessment additionally elucidated low PAH ecological risk in the surface sediments of Weihai, China.

  10. Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Nantong Coast, China.

    PubMed

    Liu, Na; Li, Xian; Zhang, Daolai; Liu, Qiang; Xiang, Lihui; Liu, Ke; Yan, Dongyun; Li, Yue

    2017-01-15

    The distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Nantong coast in China were investigated. The results indicated that the total concentrations of the 16 PAHs in the surface sediments from the study area ranged from 1.4 to 87.1ngg(-1) dw (mean value 19.9ngg(-1) dw), which were generally low compared to the adjacent offshore area and other coastal zones around the world. The selected PAH ratios and the principal components analysis for each site showed that petroleum combustion and petrogenic pollution (mainly caused by petroleum spills) were the dominant PAHs sources in the surface sediments of the coast. The ecological risk assessment indicated that most of the individual PAHs had few negative effects in this area.

  11. Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): sources and depositional history.

    PubMed

    Martins, César C; Bícego, Márcia C; Mahiques, Michel M; Figueira, Rubens C L; Tessler, Moyses G; Montone, Rosalinda C

    2011-01-01

    Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatão industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.

  12. Low-maturity Kulthieth Formation coal: A possible source of polycyclic aromatic hydrocarbons in benthic sediment of the northern Gulf of Alaska

    USGS Publications Warehouse

    Van Kooten, G. K.; Short, J.W.; Kolak, J.J.

    2002-01-01

    The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low - i.e. the coals are over mature - to be consistent with GOA sediments. We present evidence here that native coal may have been prematurely dismissed, because BRCF coals do not adequately represent the geochemical signatures of coals elsewhere in the Kulthieth Formation. Contrary to previous thought, Kulthieth Formation coals east of the BRCF have much higher PAH: TOC ratios, and the patterns of labile hydrocarbons in these low thermal maturity coals suggest a possible genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analyses of low-maturity Kulthieth Formation coal indicate the low maturity coal is a significant source of PAH. Source apportionment models that neglect this source will underestimate the contribution of native coals to the regional background hydrocarbon signature. ?? Published by Elsevier Science Ltd. on behalf of AEHS.

  13. Developing receptor-oriented methods for non-methane hydrocarbon characterisation in urban air. Part II: source apportionment

    NASA Astrophysics Data System (ADS)

    Borbon, Agnès; Fontaine, Hervé; Locoge, Nadine; Veillerot, Marc; Galloo, J. C.

    The methods and the results of non-methane hydrocarbon (NMHC) source apportionment are described at urban scale on a spatial and temporal basis. Here, hourly ambient concentrations of nearly 40 C 2-C 9 NMHC are used. Methods are based on the knowledge of the wintertime NMHC vehicle-exhaust emission ratio generally determined by simple regression analysis taking acetylene, ethylene, propene and 1,3-butadiene as auto-exhaust tracers. The RSD of the estimated source contributions is lower than 20%; the developed receptor-oriented methods are flexible and easily transposable to other areas. In winter, vehicle-exhaust emissions explain 100% of the NMHC majority levels and even isoprene. From May to November, our models revealed the temperature-dependent contribution of additional sources (0.71< r<0.90). On the one hand, the evaporation of fuel and solvent affects the whole C 4-C 9 NMHC fraction, and fluctuates between 20% and 50%, even for a northern France urban area. On the other hand, both vehicle-exhaust and biogenic emissions control the highly photoreactive isoprene distribution whatever the site; the traffic is responsible for a third of its levels in summer. Finally, the particular behaviour of the C 2-C 4 compounds pointed out dominant contributions, generally other than traffic. Suspected sources are numerous: natural gas leakage for ethane and propane, wintertime fuel evaporation for butanes and butenes, non-automotive combustion for ethylene and acetylene. Ethane and propane also showed that long-range advective transport, responsible for background concentrations, could significantly contribute to the hydrocarbon levels with a high atmospheric residence time (from 20% to 50%).

  14. Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

    PubMed Central

    2014-01-01

    Background Coastal sediments in the northern Gulf of Mexico have a high potential of being contaminated by petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), due to extensive petroleum exploration and transportation activities. In this study we evaluated the spatial distribution and contamination sources of PAHs, as well as the bioavailable fraction in the bulk PAH pool, in surface marsh and shelf sediments (top 5 cm) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g−1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the lowest concentrations in shelf sediments. The PAH concentrations correlated positively with atomic C/N ratios of sedimentary organic matter (OM), suggesting that terrestrial OM preferentially sorbs PAHs relative to marine OM. PAHs with 2 rings were more abundant than those with 5–6 rings in continental shelf sediments, while the opposite was found in marsh sediments. This distribution pattern suggests different contamination sources between shelf and marsh sediments. Based on diagnostic ratios of PAH isomers and principal component analysis, shelf sediment PAHs were petrogenic and those from marsh sediments were pyrogenic. The proportions of bioavailable PAHs in total PAHs were low, ranging from 0.02% to 0.06%, with higher fractions found in marsh than shelf sediments. Conclusion PAH distribution and composition differences between marsh and shelf sediments were influenced by grain size, contamination sources, and the types of organic matter associated with PAHs. Concentrations of PAHs in the study area were below effects low-range, suggesting a low risk to organisms and limited transfer of PAHs into food web. From the source analysis, PAHs in shelf sediments mainly originated from direct petroleum contamination, while those in marsh sediments were from combustion of fossil fuels. PMID:24641695

  15. Distribution and source apportionment of polycyclic aromatic hydrocarbons in surface sediments from Zhoushan Archipelago and Xiangshan Harbor, East China Sea.

    PubMed

    Wang, Xiaoyan; Xu, Huanzhi; Zhou, Yongdong; Wu, Changwen; Kanchanopas-Barnette, Praparsiri

    2015-12-30

    Zhoushan Archipelago and the adjacent Xiangshan Harbor are important commercial, tourism, fishing, and mariculture areas. Considering the concern on the effects of anthropogenic activities on the environment, the level and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments were investigated. The sum of 16 PAH (∑16 PAH) concentrations in the Zhoushan Archipelago ranged from 3.67 to 31.30 ng g(-1) d.w., with a mean of 15.01 ± 1.21 ng g(-1) d.w., and that in Xiangshan Harbor varied from 11.58 to 481.44 ng g(-1) d.w., with a mean of 62.52 ± 32.85 ng g(-1) d.w. Diagnostic ratios and factor analysis were performed to identify PAH sources. Results show that PAHs have mixed origins (i.e., traffic-related sources, coal combustion, petrogenic sources, and biomass burning), with pyrolytic-related pollution as the dominant source. This study provided a baseline to promote environmental protection and pollution episode monitoring in the East China Sea.

  16. Polycyclic Aromatic Hydrocarbons in the Coastal Sediments of Southwestern Taiwan: an Appraisal of Diagnostic Ratios in Source Recognition

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Lee, C.; Fang, M.; Liu, J.

    2008-12-01

    Fifty seven surface sediment samples along the coast of southwestern Taiwan were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs). Concentrations of total PAH (sum of 28 PAH compounds) ranged from15 to 907 ng/g dry weight (dw). Diagnostic ratios revealed petroleum origin PAHs was a significant source to the sediments at Gao-ping estuary stations. However, sediments of Kaohsiung coast might be a combustion-derived PAHs of petroleum, coal, and vehicles. The result of perylene/penta-aromatic PAHs ratio was higher in Tainan coast, Hsinda harbour coast, and some off-shore stations of Kaohsiung coast, suggesting a diagenetic PAH source. A comprehensive appraisal suggested that certain diagnostic ratios are much useful in tracing the distribution of PAHs from specific sources in southwestern Taiwan. P/A (phenanthrene/anthracene) ratio is a better indicator than MP/P (methylphenanthrenes/phenanthrene) ratio in tracing petrogenic PAHs. Moreover, BaA/Chr (benzo(a)anthracene/chrysene) and IP/BghiP (indeno(1,2,3- c,d)pyrene/benzo(g,h,i)perylene) ratios can provide more appropriate assignments than BaP/BeP (benzo(a)pyrene/benzo(e)pyrene) and BbF/BkF (benzo(b)fluoranthcene/benzo(k)fluoranthcene) in distinguishing PAHs from various pyrogenic sources in this study. More specifically, automobile and coal sources were found dominant in stations of pyrogenic group delineated by principal component analysis (PCA).

  17. A novel approach for apportionment between primary and secondary sources of airborne nitrated polycyclic aromatic hydrocarbons (NPAHs)

    NASA Astrophysics Data System (ADS)

    Lin, Yan; Qiu, Xinghua; Ma, Yiqiu; Wang, Junxia; Wu, Yusheng; Zeng, Limin; Hu, Min; Zhu, Tong; Zhu, Yifang

    2016-08-01

    Nitrated polycyclic aromatic hydrocarbons (NPAHs) are strong environmental mutagens and carcinogens originating from both primary emissions and secondary reactions in the atmosphere. The sources and the toxicity of different NPAH species could vary greatly; therefore a specie-specific source apportionment is essential to evaluate their health risks and to formulate controlling regulations. However, few studies have reported source apportionment of NPAHs species to date. In this study, we developed an easy-to-perform method for the apportionment of primary versus secondary sources of airborne NPAHs based on the relationship between NPAHs and NO2. After log-transformation of both NPAHs and NO2 concentrations, a slope of β between these two variables was obtained by the linear regression. When β is significantly smaller than 1, it indicates primary emissions while β significantly greater than 1 suggests secondary formation. We have validated this method with data previously collected in Beijing. A good correlation, with R value of 0.57, was observed between results produced by this new method and by Positive Matrix Factorization (PMF). The correlation could be further improved (R = 0.71) if the gas/particle partition of NPAHs is taken into consideration. This developed method enables the source apportionment for individual NPAHs species and could be used to validate the results of other receptor models.

  18. The emerging source of polycyclic aromatic hydrocarbons from mining in the Tibetan Plateau: Distributions and contributions in background soils.

    PubMed

    Li, Jun; Yuan, Guo-Li; Li, Ping; Sun, Yong; Yu, Hong-Hui; Wang, Gen-Hou

    2017-04-15

    The Tibetan Plateau (TP) serves as the background for persistent organic pollutants around the world. In addition to outside sources, local sources greatly contribute to the environment of the TP in recent decades. Mining activity could serve as an emerging source of polycyclic aromatic hydrocarbons (PAHs), although this issue has been neglected in the TP until now. To investigate the distributions and contributions of PAHs transported from mining activity, forty-one surface soil samples along six sampling directions were collected at a regular distance from the Jiama mining area (JMA) of the TP at altitudes between 3726 and 4863m. The total concentration of 16 PAHs was 52.34±22.58ng/g. The result of the source identification suggested that mining activity represented the primary source for heavy molecular weight (HMW) PAHs in soils, while light molecular weight (LMW) and middle molecular weight (MMW) PAHs were contributed by multiple sources. For HMW PAHs, the concentrations and proportions decreased logarithmically with transport distance from the JMA. Furthermore, the transport distance of HMW PAHs was found to be affected by the prevailing wind direction. In addition to transport from the source area, the distributions of LMW and MMW PAHs were also influenced by the altitude. In the impact area of Jiama mining activity, the soil mass inventory was estimated to be 6.4±0.8tons for HMW PAHs. In future decades, HMW PAHs emitted from Jiama mining activity are projected to exceed 5% of the annual local emission in the TP. Our study evidenced that Tibetan mining activity serves as an important emerging source of PAHs, which would be transported within the TP and threaten the fragile ecosystem of the TP.

  19. Mineralogy And Geochemistry Of Mud From Andaman Mud Volcanoes And Its Potential As A Hydrocarbon Source

    NASA Astrophysics Data System (ADS)

    Datta, S.; Bhattacharyya, C. R.

    2007-12-01

    Mud volcanoes are a common feature, reported by several workers, in the Baratang Island of Middle Andamans, India. The association of methane gas and adsorbed hydrocarbons in the mud has been cited well by scientists working in Andamans and also by others working on other eruption areas around the world. Our intended work centres around delineating the nature of such mud volcanoes in the above terrain, their chemical composition with special reference to the clay minerals formed under this sedimentary volcanism environment and exploiting such volcanic deposits towards potential hydrocarbon reserves (if any). The analysis so far suggests that, at any instant of time, gas vents at variable rates in different gas channels at the same site, and that the compositional differences in these vent gases are nearly as large as can be produced by hydrate crystallization. Our hypothesis is compatible with geologic generalizations that venting evolves from fast (mud volcano), to intermediate (hydrate crystallization), to slow (carbonate precipitation) if venting organized into more discrete vents with time. The most realistic agent that explains the observed effects is a rapid local emission of mud and/or water. Powder XRD of bulk mud samples enable identification of the complete suite of minerals, in addition to the clay minerals. Variability in modal mineralogy is tracked using Rietveld Method of crystal structure refinement. In addition, micro- XRD of sample cores in situ provide mineral identification as well as textural information such as grain size and distribution (e.g. fine-grained polycrystalline versus larger crystals) as well as preferred orientation (e.g. due to flow layering or strain). Stable isotopes of the separated clay minerals (smectite- and illite-rich extruded mud) from the mud volcanoes will be utilized towards the knowledge of nature of volcanism in the Andaman areas. The most likely mechanism believed is re-hydration of shales by both hydrocarbons and a

  20. [Tobacco smoking as a source of exposure of pregnant women and newborn on polycyclic aromatic hydrocarbons].

    PubMed

    Piekoszewski, Wojciech; Florek, Ewa; Breborowicz, Grzegorz H

    2006-01-01

    An essential problem related to tobacco smoking is exposure of children in the foetal period and early childhood to toxic compounds. The aim of this paper was to assess the exposure of pregnant women and their newborns to polycyclic aromatic hydrocarbons as a consequence of tobacco smoking. The exposure to tobacco smoke was determined through surveys and cotinine measurement in the urine of pregnant women and newborns, and the exposure to polycyclic aromatic hydrocarbons has been determined by measure of 1-hydroxypyrene in the same biological material. The cotinine concentration in the urine of smoking women and their newborns was respectively 416.0 +/- 319.9 ng/mg of creatinine and 46.5 +/- 37.2 ng/mg of creatinine. In case of non-smoking as well as non-exposed patients and their newborns, the concentration of cotinine was 0. The correlation between the concentration of cotinine in the urine of smoking women and their newborns was shown. The mean concentration of 1-hydroxypyrene in the urine of smoking patients was 0.65 +/- 0.45 ng/mg of creatinine, whereas in the urine of newborns, it was 0.46 +/- 0.41 ng/mg of creatinine. The concentration of 1-hydroxypyrene in the urine of smokers was increased together with the increase of cotinine, and the correlation factor was 0.5128. Such dependence was not indicated for concentrations of these compounds in the urine of newborns of these women. Within the group of non-smoking women, the concentration of 1-hydroxypyene urine of women was 0.25 +/- 0.29 ng/mg of creatinine, whereas among children 0.20 +/- 0.23 ng/mg of creatinine. In both examined group (smoking and non-smoking women) there is a dependence between the concentration of 1-hydroxypyrene in the urine of women and their newborns. The research concerning the assessment of exposure of pregnant women and their newborns to polycyclic aromatic hydrocarbons was conducted, and at the same time it was proven, that the placenta does not constitute a barrier for these

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

    PubMed

    Nielsen, T; Jørgensen, H E; Larsen, J C; Poulsen, M

    1996-10-28

    The presence of polycyclic aromatic hydrocarbons (PAH), mutagens and other air pollutants was investigated in a busy street in central Copenhagen and in a park area adjacent to the street. The winter concentration of benzo(a)pyrene was 4.4 +/- 1.2 ng/m3 in the street air and 1.4 +/- 0.6 ng/m3 in the city park. The atmospheric concentrations of PAH decreased in the order of: street > city background air approximately suburbs > village > open land. The traffic contribution of PAH to street air was estimated to be 90% on working days and 60% during weekends and its contribution to city background air was estimated to be 40%. Four different approaches to evaluate the health effects are discussed. The direct effect of PAH air pollution, and other mutagens, is considered to be a maximum of five lung cancer cases each year out of one million people.

  2. Distribution and sources of hydrocarbons in surface sediments of Gemlik Bay (Marmara Sea, Turkey).

    PubMed

    Unlü, Selma; Alpar, Bedri

    2006-07-01

    Seabottom sediments from Gemlik Bay, one of the most polluted spots in SW Marmara Sea, were analyzed for parent polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry. The concentration of 14 PAH compounds in sediment samples collected from 61 locations are distributed in a broad spectrum from low to very high concentration levels (50.8-13482 ng g-1). No significant correlation was found between summation operatorPAHs and organic carbon content while summation operatorPAHs increase slightly with silt/clay ratio. Therefore the distribution and concentrations of PAHs would be determined more by direct input, rather than by the type of sediment found locally. The most polluted areas are distributed nearshore eastern (Gemlik) and southern (Kursunlu, Mudanya and Trilye) coasts which are mainly influenced by rapid ecotourism development, direct discharges from rivers, surface run-off and drainage from port areas, domestic and industrial effluent discharges through outfalls and various contaminants from ships. Special PAH compound ratios, such as Phe/Anth, Flu/Py, B[a]A/Chry; LMWPAH/HMWPAH; Per/; Per/summation operatorPAH; Per/summation operator(penta-aromatics) and Flu/(Py+Flu), were calculated to evaluate different hydrocarbon origins and their relative importance. Pyrolytic activity is dominant along the highly-populated eastern and southern coasts. Meanwhile, petrogenic activity mixed with pyrolytic activity is a matter of fact in front of the main industrial-tourism ports and anchoring areas as well. Higher concentration of perylene are distributed along the mostly polluted eastern and southern coastal areas, however, the concentrations of perylene relative to the penta-aromatic isomers are dominant especially in the northern and deepest sectors of the bay, indicating diagenetic origin for the presence of perylene.

  3. Temperature and injection water source influence microbial community structure in four Alaskan North Slope hydrocarbon reservoirs

    PubMed Central

    Piceno, Yvette M.; Reid, Francine C.; Tom, Lauren M.; Conrad, Mark E.; Bill, Markus; Hubbard, Christopher G.; Fouke, Bruce W.; Graff, Craig J.; Han, Jiabin; Stringfellow, William T.; Hanlon, Jeremy S.; Hu, Ping; Hazen, Terry C.; Andersen, Gary L.

    2014-01-01

    A fundamental knowledge of microbial community structure in petroleum reservoirs can improve predictive modeling of these environments. We used hydrocarbon profiles, stable isotopes, and high-density DNA microarray analysis to characterize microbial communities in produced water from four Alaskan North Slope hydrocarbon reservoirs. Produced fluids from Schrader Bluff (24–27°C), Kuparuk (47–70°C), Sag River (80°C), and Ivishak (80–83°C) reservoirs were collected, with paired soured/non-soured wells sampled from Kuparuk and Ivishak. Chemical and stable isotope data suggested Schrader Bluff had substantial biogenic methane, whereas methane was mostly thermogenic in deeper reservoirs. Acetoclastic methanogens (Methanosaeta) were most prominent in Schrader Bluff samples, and the combined δD and δ13C values of methane also indicated acetoclastic methanogenesis could be a primary route for biogenic methane. Conversely, hydrogenotrophic methanogens (e.g., Methanobacteriaceae) and sulfide-producing Archaeoglobus and Thermococcus were more prominent in Kuparuk samples. Sulfide-producing microbes were detected in all reservoirs, uncoupled from souring status (e.g., the non-soured Kuparuk samples had higher relative abundances of many sulfate-reducers compared to the soured sample, suggesting sulfate-reducers may be living fermentatively/syntrophically when sulfate is limited). Sulfate abundance via long-term seawater injection resulted in greater relative abundances of Desulfonauticus, Desulfomicrobium, and Desulfuromonas in the soured Ivishak well compared to the non-soured well. In the non-soured Ivishak sample, several taxa affiliated with Thermoanaerobacter and Halomonas predominated. Archaea were not detected in the deepest reservoirs. Functional group taxa differed in relative abundance among reservoirs, likely reflecting differing thermal and/or geochemical influences. PMID:25147549

  4. Emission inventory and sources of polycyclic aromatic hydrocarbons in the atmosphere at a suburban area in Taiwan.

    PubMed

    Yang, Hsi-Hsien; Chen, Chia-Mei

    2004-09-01

    The application of a chemical mass balance air pollution model to ambient measurements of polycyclic aromatic hydrocarbons (PAHs) is presented. Sixteen air samples were collected at seven sites in a suburban area in Taiwan and analyzed for the concentration of 21 compounds between July 2001 and September 2001. Each ambient sample was evaluated for the PAH contribution from six sources (heavy oil combustion, natural gas combustion, coal combustion, diesel combustion, vehicles and municipal solid waste incinerator). Average predictions agree well with the emission inventory. By this method, the average contributions are 49%, 14%, 22%, 12%, and 2% from vehicles, heavy oil combustion, natural gas combustion, coal combustion and diesel combustion at these seven receptors. By far, vehicles are the major PAH emission sources and municipal solid waste incinerator is a minor contributor. The calculated result of particulate PAHs is compared with that of total (gaseous and particulate) PAHs. The estimate based on total PAHs is better than the estimate based on particulate PAHs only. Contributions of eight low reactive PAHs for the same emission sources and receptors were calculated. Atmospheric reactivity seems not a problem for source apportionment in this study.

  5. Source apportionment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) associated to airborne PM10 by a PMF model.

    PubMed

    Callén, M S; Iturmendi, A; López, J M; Mastral, A M

    2014-02-01

    In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001-2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 x 10(-5) per ng/m(3) BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies.

  6. Concentrations of polycyclic aromatic hydrocarbons in New York City community garden soils: Potential sources and influential factors.

    PubMed

    Marquez-Bravo, Lydia G; Briggs, Dean; Shayler, Hannah; McBride, Murray; Lopp, Donna; Stone, Edie; Ferenz, Gretchen; Bogdan, Kenneth G; Mitchell, Rebecca G; Spliethoff, Henry M

    2016-02-01

    A total of 69 soil samples from 20 community gardens in New York City (New York, USA) were collected and analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) and black carbon. For each garden, samples were collected from nongrowing areas (non-bed) and from vegetable-growing beds, including beds with and without visible sources of PAHs. The sum of the US Environmental Protection Agency's 16 priority PAHs ranged up to 150 mg/kg, and the median (5.4 mg/kg) and mean (14.2 mg/kg) were similar to those previously reported for urban areas in the northeast United States. Isomer ratios indicated that the main sources of PAHs were petroleum, coal, and wood combustion. The PAH concentrations were significantly and positively associated with black carbon and with modeled air PAH concentrations, suggesting a consistent relationship between historical deposition of atmospheric carbon-adsorbed PAHs and current PAH soil concentrations. Median PAH soil concentration from non-bed areas was higher (7.4 mg/kg) than median concentration from beds in the same garden (4.0 mg/kg), and significantly higher than the median from beds without visible sources of PAHs (3.5 mg/kg). Median PAH concentration in beds from gardens with records of soil amendments was 58% lower compared with beds from gardens without those records. These results suggest that gardening practices in garden beds without visible sources of PAHs contribute to reduce PAH soil concentrations.

  7. The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrene, E.; Francois, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-05-01

    The extent to which wood growth is limited by carbon (C) supply (i.e. source control) or by cambial activity (i.e. sink control) will strongly determine the responses of trees to global changes. Nevertheless, the physiological processes that are responsible for limiting forest growth are still a matter of debate. The aim of this study was to evaluate the key determinants of the annual C allocation to wood along large soil and climate regional gradients over France. The study was conducted for five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). The drivers of stand biomass growth were assessed on both inter-site and inter-annual scales. Our data set comprised field measurements performed at 49 sites (931 site-years) that included biometric measurements and a variety of stand characteristics (e.g. soil water holding capacity, leaf area index). It was complemented with process-based simulations when possible explanatory variables could not be directly measured (e.g. annual and seasonal tree C balance, bioclimatic water stress indices). Specifically, the relative influences of tree C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in the stand C allocation to wood was predominantly driven by age-related decline. The direct effects of temperature and water stress on sink activity (i.e. effects independent from their effects on the C supply) exerted a strong influence on the annual stand wood growth in all of the species considered, including deciduous temperate species. The lagged effect of the past environmental conditions (e.g. the previous year's water stress and low C uptake) significantly affected the annual C allocation to wood. The C supply

  8. The dynamics of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth.

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas K.; Dufrêne, Eric; François, Christophe; Soudani, Kamel; Ourcival, Jean-Marc; Leadley, Paul; Delpierre, Nicolas

    2015-04-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >10000 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  9. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments from the Bering Sea and western Arctic Ocean.

    PubMed

    Zhao, Mengwei; Wang, Weiguo; Liu, Yanguang; Dong, Linsen; Jiao, Liping; Hu, Limin; Fan, Dejiang

    2016-03-15

    To analyze the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) and evaluate their potential ecological risks, the concentrations of 16 PAHs were measured in 43 surface sediment samples from the Bering Sea and western Arctic Ocean. Total PAH (tPAH) concentrations ranged from 36.95 to 150.21 ng/g (dry weight). In descending order, the surface sediment tPAH concentrations were as follows: Canada Basin>northern Chukchi Sea>Chukchi Basin>southern Chukchi Sea>Aleutian Basin>Makarov Basin>Bering Sea shelf. The Bering Sea and western Arctic Ocean mainly received PAHs of pyrogenic origin due to pollution caused by the incomplete combustion of fossil fuels. The concentrations of PAHs in the sediments of the study areas did not exceed effects range low (ERL) values.

  10. Analysis and Sources of Polycyclic Aromatic Hydrocarbons in Soil and Plant Samples of a Coal Mining Area in Nigeria.

    PubMed

    Ugwu, K E; Ukoha, P O

    2016-03-01

    This study analysed coal, plant and soil samples collected from the vicinity of Okobo coal mine in Nigeria for Polycyclic aromatic hydrocarbons (PAHs) and evaluated the sources of the PAH contamination in the environmental samples. The environmental samples were extracted by sonication using a ternary solvent system and analysed for 16 PAHs by gas chromatography-mass spectrometry (GC-MS). The results of the analysis of the samples identified some of the target PAHs. The ranges of total concentrations (in mg/kg) of PAHs in the coal, plant and soil samples were, 0.00-0.04, 0.00-0.16 and 0.00-0.01 respectively. The evaluation of the results of the PAH analysis of the environmental samples using diagnostic ratios revealed that the PAHs in the soil samples were mainly of petrogenic origin, while those in plant samples indicated mixture of petrogenic and pyrolytic origins.

  11. Sources and pathways of polycyclic aromatic and saturated hydrocarbons in the Arkona Basin (Southern Baltic Sea, Central Europe)

    SciTech Connect

    Schulz, H.M.

    1996-12-31

    The Baltic Sea (Central Europe) is surrounded by coastal regions with long histories of industrialization. The heavy metal profiles in the sediments in the center of the Arkona Basin, one of the depressions of the southern Baltic Sea area, clearly reflect the historical anthropogenic influence. The Arkona Basin-is the final sink for materials derived from the Oder river which drains a highly polluted industrial area of Eastern Europe. Surficial muddy sediments from a close-meshed field of sampling-points were analyzed for distribution patterns of aliphatics and quantities and ratios of selected polycyclic aromatic hydrocarbons (PAH). These compounds are thought to reflect anthropogenic pollution related to emissions from traffic, heating, etc. We use these marker substances to test if the basin sediments reflect riverine input, and if additional sources can be identified.

  12. Spatiotemporal patterns and source implications of aromatic hydrocarbons at six rural sites across China's developed coastal regions

    NASA Astrophysics Data System (ADS)

    Zhang, Zhou; Zhang, Yanli; Wang, Xinming; Lü, Sujun; Huang, Zhonghui; Huang, Xinyu; Yang, Weiqiang; Wang, Yuesi; Zhang, Qiang

    2016-06-01

    Aromatic hydrocarbons are important anthropogenic precursors of tropospheric ozone and secondary organic aerosols. Here we measured ambient aromatic hydrocarbons from March 2012 to February 2014 at six rural sites in China's developed coastal regions. On average, benzene (B) comprised > 50% of total benzene (B), toluene (T), ethylbenzene (E), and xylenes (X) (BTEX) at sites in the Northeast China Plain (NECP) or in the North China Plain (NCP), whereas T, E, and X accounted for > 77% of total BTEX at sites in the Yangtze River Delta (YRD) and the Pearl River Delta in the south. BTEX at the northern sites was significantly correlated (p < 0.01) with combustion tracer-carbon monoxide (CO) but weakly correlated with traffic marker-methyl tert-butyl ether (MTBE), suggesting that their main sources were coal and biofuel/biomass burning with substantially elevated B levels during the winter heating period. In contrast, BTEX at the southern sites originated mainly from traffic-related and/or industrial emission sources, as indicated by the poor correlations with CO but highly significant (p < 0.01) correlations with MTBE and tetrachloroethylene, an industrial emission tracer. The B/CO emission ratios from measurement agreed within a factor of 2 with that of a previous widely used emission inventory of China, but the T/CO ratio at the NECP site and the o-X/CO ratio at the NCP site were 29% and 38% of that in the inventory, respectively; the E/CO and X/CO ratios at the YRD site were 3.2-3.5 fold that in the emission inventory.

  13. Contributions and source identification of biogenic and anthropogenic hydrocarbons to secondary organic aerosols at Mt. Tai in 2014.

    PubMed

    Zhu, Yanhong; Yang, Lingxiao; Kawamura, Kimitaka; Chen, Jianmin; Ono, Kaori; Wang, Xinfeng; Xue, Likun; Wang, Wenxing

    2017-01-01

    Ambient fine particulate matter (PM2.5) and volatile organic compounds (VOCs) collected at Mt. Tai in summer 2014 were analysed and the data were used to identify the contribution of biogenic and anthropogenic hydrocarbons to secondary organic aerosols (SOA) and their sources and potential source areas in high mountain regions. Compared with those in 2006, the 2014 anthropogenic SOA tracers in PM2.5 aerosols and VOC species related to vehicular emissions exhibited higher concentrations, whereas the levels of biogenic SOA tracers were lower, possibly due to decreased biomass burning. Using the SOA tracer and parameterisation method, we estimated the contributions from biogenic and anthropogenic VOCs, respectively. The results showed that the average concentration of biogenic SOA was 1.08 ± 0.51 μg m(-3), among which isoprene SOA tracers were dominant. The anthropogenic VOC-derived SOA were 7.03 ± 1.21 μg m(-3) and 1.92 ± 1.34 μg m(-3) under low- and high-NOx conditions, respectively, and aromatics made the greatest contribution. However, the sum of biogenic and anthropogenic SOA only contributed 18.1-49.1% of the total SOA. Source apportionment by positive matrix factorisation (PMF) revealed that secondary oxidation and biomass burning were the major sources of biogenic SOA tracers. Anthropogenic aromatics mainly came from solvent use, fuel and plastics combustion and vehicular emissions. However, for > C6 alkanes and cycloalkanes, vehicular emissions and fuel and plastics combustion were the most important contributors. The potential source contribution function (PSCF) identified the Bohai Sea Region (BSR) as the major source area for organic aerosol compounds and VOC species at Mt. Tai.

  14. Distribution and source apportionment of polycyclic aromatic hydrocarbons in soils and leaves from high-altitude mountains in southwestern china.

    PubMed

    Shi, Bingfang; Wu, Qilin; Ouyang, Huixiang; Liu, Xixiang; Ma, Bo; Zuo, Weiyuan; Chen, Shengyu

    2014-11-01

    Several studies have investigated the distribution patterns and geographic sources of polycyclic aromatic hydrocarbons (PAHs) in mountainous areas. Little is known about how different sources contribute to PAH concentrations at different elevations along mountain slopes. To estimate the distribution and sources of PAHs at different altitudes in mountainous areas of southwestern China, samples of soils and leaves from trees were collected from 1000 to 1500 m asl in the Dawangling forest and analyzed for PAHs. Total PAH concentrations ranged from 93.9 to 802.3 ng g (average, 252.3 ng g) in soils and from 4.1 to 100.9 ng g (average, 23.1 ng g) in leaves. Our results suggest that soil PAH levels in the study area could be classified as "weakly contaminated." The PAH levels in leaves from the Dawangling forest were lower than those found in Himalayan spruce needles from the central Himalayas in China and from an agricultural station in southern England. Total PAHs in the Dawangling forest soils increased with elevation, primarily due to the low-molecular-weight PAHs, which accumulated in samples from higher altitudes. In contrast, high-molecular-weight PAHs were inversely related to or unrelated to elevation. The PAH profiles were similar in soils and leaves from all mountainous regions. Diagnostic ratios showed that the PAHs in soils at different altitudes were from different pollution emission sources; therefore, PAHs in the entire study area were probably derived from mixed sources. Cluster analyses confirmed that liquefied petroleum gas, coal/wood combustion, and petroleum combustion were likely the predominant PAH sources in this region.

  15. Historical record and source apportionment of polycyclic aromatic hydrocarbons in the Lianhuan Lake sediments.

    PubMed

    Sun, Li; Zang, Shuying; Xiao, Haifeng

    2011-07-01

    Polycyclic aromatic hydrocarbons (PAHs) in a sediment core from the north Lianhuan Lake were collected to investigate its historical changes in the last one hundred years and its possible influence on ecological system in the lake. GC-MS was used to determine the concentrations of PAHs, and sediment chronological age was examined by (137)Cs dating approach. The concentrations of 16 different kinds of PAHs in the sediment samples ranged from 297 to 1,327 ng g(-1), and the low molecular weight (LMW) were predominant. The intensification of industrial and anthropogenic activities in the Daqing oil field may play the key role in the increase of PAHs concentrations in the late 1950s. To the early 1980s, the PAHs concentrations significantly decreased due to the grain size coarsening in the sediment samples, which was confirmed by the precipitation information. The 5-6 rings PAHs concentrations increased in the early 1980s may be attributed to the consumption of petroleum, coal and wood. The results showed that both the PAHs historical record and current concentrations may cause some influence on the Lianhuan Lake ecological system. The toxicology research on this ecological system should be done in the further investigations for determining the PAHs damage on human and ecological system health.

  16. Sources and Variability of Petroleum Hydrocarbon Residues in Sediments of Chilika Lagoon, East Coast of India.

    PubMed

    Mohanty, Bita; Muduli, Pradipta R; Cooper, Gregory; Barik, Saroja K; Mahapatro, Debasish; Behera, Alaya T; Pattnaik, Ajit K

    2017-03-14

    The spatio-temporal distribution and the controlling factors of petroleum hydrocarbons (PHCs) in sediments of Chilika lagoon was investigated. Samples were collected during three seasons and quantified using UV-fluorescence spectroscopy. Concentrations of PHCs in surface sediments varies from 0.18 to 12.13 ppm (mean 3.71 ± 3.94 ppm). Compared to the lagoon, the monitoring stations adjacent to jetties with high boating activities tend to have higher PHC concentrations, suggesting that the contribution is likely to be from fossil fuel combustion and accidental seepage. The sediment organic matter (OM) of Chilika ranges from 0.26% to 6.23%. PHC maintains a positive correlation with OM (p < 0.05; f = 0.334), indicating the long term deposition of PHC as sediment OM. However, there is no significant relation between PHC and sediment texture, indicating its negligible control over PHC. The recorded PHC concentrations are below the threshold limit (70 ppm) as classified by United States (US) National Academy of Sciences (NAS) and also lower than those reported from similar ecosystems in India and overseas. Since the long term deposition and the bioaccumulation of PHC cannot be avoided, it is essential to monitor these parameters periodically.

  17. Effects of pollution sources and soil properties on distribution of polycyclic aromatic hydrocarbons and risk assessment.

    PubMed

    Zhang, Juan; Yang, Jun-cheng; Wang, Ren-qing; Hou, Hong; Du, Xiao-ming; Fan, Shu-kai; Liu, Jiang-sheng; Dai, Jiu-lan

    2013-10-01

    In this study, the concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil profiles and the soil properties were analyzed in Hunpu, a typical wastewater irrigation area, northeast of China. The total concentrations of 16 priority control PAHs ranged from 7.88 to 2,231.42 μg/kg. Among 16 PAHs, the most abundant was Phenanthrene and the 3- or 4- ring PAHs were predominant. The PAH concentrations were higher in the upland fields near the oil wells, whereas leaching of PAH into the groundwater caused low concentrations in the paddy fields. The geochemical indices and the results from the principal component analysis of all 16 PAHs indicated that PAHs were mainly from atmospheric dusts in the top soil in I-1P/I-3P/I-7P and through soil profiles in I-4U/I-5P/I-8U, whereas those in the bottom layers were mainly from petroleum production and wastewater irrigation in I-1P/I-3P/I-7P and through soil profiles in I-2U and I-6U. In the redundancy analysis, PAHs exhibited negative correlation with pH, depth, silt, and clay, but had positive correlation with sand and organic matter. Finally, total toxic equivalent in the soil profiles and the calculated health risk of PAHs in the surface soil using contaminated land exposure assessment model elucidated the cancer risk that PAHs pose on human health in the Hunpu region.

  18. Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in soils from typical oil-sewage irrigation area, Northeast China.

    PubMed

    Li, Xiaojun; Li, Peijun; Lin, Xin; Gong, Zongqiang; Fan, Shuxiu; Zheng, Le; Verkhozina, E A

    2008-08-01

    Spatial distribution and sources of 16 priority polycyclic aromatic hydrocarbons (16 EPA-PAHs) in soils were studied in Shenfu Irrigation Area (SIA) located at northeast of China. SIA (1.3 x 10(4) ha) was an important agricultural farmland irrigated with oil-sewage since the 1960s. Soil profiles at 91 sites controlling all SIA were sampled. The results demonstrated that four- and five-ring PAHs accounted for 71.2% and 73.0% of the total PAHs in surface (0-20 cm) and subsurface (20-30 cm) soil, respectively. Phenanthrene (Phe), Fluoranthene (Fla), Pyrene (Pyr), Benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP) were identified as five dominant individual PAHs. Generally, there was a decreasing trend in concentrations of 16 EPA-PAHs from upper to lower reaches (by distance away from source) within 0.6-12.36 mg kg(-1) and 0.04-4.99 mg kg(-1) in surface and subsurface soil, respectively. The concentrations of 16 EPA-PAHs in the surface soil were threefold higher than those in the subsurface soil. A combination of grass, wood or coal combustion and petroleum combustion in surface soil and a combination of grass, wood or coal combustion and petroleum sources in subsurface soil might be the most significant contributors of 16 EPA-PAHs in SIA, indicating different pollution periods.

  19. Probabilistic ecological risk assessment and source apportionment of polycyclic aromatic hydrocarbons in surface sediments from Yellow Sea.

    PubMed

    Liu, Ai-Xia; Lang, Yin-Hai; Xue, Li-Dong; Liao, Shu-Lin; Zhou, Hong

    2009-11-01

    Based on the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 12 surface sediment samples from Yellow sea, the relative risk of 9 PAHs was investigated using joint risk probability distribution curves and overlapping area, which were generated based on the distributions of exposure and acute toxicity data (LC(50)), and the sources of PAHs were apportioned using principal component analysis. It was found that joint probability curve and overlapping area indicated the acceptable ecological risk of individual PAHs, only a small fraction of the benthic organisms was affected. Among the nine PAHs studied, the overall risk of pyrene was the highest, with that of naphthalene the lowest. For lower exposure levels at which the percentage of species affected was less than 10%, the risk associated with phenanthrene and fluorene were clearly higher than that of the other seven PAHs. It was indicated that PAHs in surface sediments mainly originated from vehicular emissions, coal combustion sources, coke oven emission and wood combustion, petroleum origin made little influence on sources of PAHs by PCA.

  20. Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

    PubMed Central

    Wang, Wentao; Massey Simonich, Staci L.; Xue, Miao; Zhao, Jingyu; Zhang, Na; Wang, Rong; Cao, Jun; Tao, Shu

    2013-01-01

    The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote–rural village–urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources. PMID:20199833

  1. Distribution, sources and ecological risk assessment of polycyclic aromatic hydrocarbons in water and sediments from Tiber River and estuary, Italy.

    PubMed

    Montuori, Paolo; Aurino, Sara; Garzonio, Fatima; Sarnacchiaro, Pasquale; Nardone, Antonio; Triassi, Maria

    2016-10-01

    The concentration, source and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. The 16 priority PAHs were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments collected from 21 sites in four different seasons. Total concentrations of PAHs ranged from 10.3 to 951.6ngL(-1) and from 36.2 to 545.6ngg(-1) in water (sum of DP and SPM) and in sediment samples, respectively. The compositions of PAHs showed that 2- to 4-ring PAHs were abundant in DP, 4- to 6-ring PAHs were predominant in SPM samples, and 4- to 5-ring PAHs were abundant in sediments. The diagnostic ratio analysis indicated that the PAHs mainly had a pyrolytic source. The toxic equivalent concentration of carcinogenic PAHs was 45.3ngTEQg(-1), suggesting low carcinogenic risk for Tiber River. Total PAHs loads into the sea were calculated in about 3161.7kgyear(-1) showing that this river is one of the main contribution sources of these contaminants to the Tyrrhenian Sea.

  2. Probabilistic ecological risk assessment and source apportionment of polycyclic aromatic hydrocarbons in surface sediments from Yellow Sea

    SciTech Connect

    Liu, A.X.; Lang, Y.H.; Xue, L.D.; Liao, S.L.; Zhou, H.

    2009-11-15

    Based on the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 12 surface sediment samples from Yellow Sea, the relative risk of 9 PAHs was investigated using joint risk probability distribution curves and overlapping area, which were generated based on the distributions of exposure and acute toxicity data (LC50), and the sources of PAHs were apportioned using principal component analysis. It was found that joint probability curve and overlapping area indicated the acceptable ecological risk of individual PAHs, only a small fraction of the benthic organisms was affected. Among the nine PAHs studied, the overall risk of pyrene was the highest, with that of naphthalene the lowest. For lower exposure levels at which the percentage of species affected was less than 10%, the risk associated with phenanthrene and fluorene were clearly higher than that of the other seven PAHs. It was indicated that PAHs in surface sediments mainly originated from vehicular emissions, coal combustion sources, coke oven emission and wood combustion, petroleum origin made little influence on sources of PAHs by PCA.

  3. Identifying sources of chlorinated aliphatic hydrocarbons in a residential area in Italy using the integral pumping test method

    NASA Astrophysics Data System (ADS)

    Alberti, Luca; Lombi, Silvia; Zanini, Andrea

    2011-09-01

    The results of integral pumping tests (IPTs) performed in the city of Fabriano, Italy, are presented. The IPT methodology was developed by the European Union project INCORE, as a tool for groundwater investigation and source localization in contaminated areas. This methodology consists of a multiple-well pumping test in which the wells are positioned along a control plane downstream of suspected contaminant source zones and perpendicular to the mean groundwater flow direction. During the pumping, concentration time series of target contaminants are measured. In Fabriano, two control planes were realized to identify a chlorinated aliphatic hydrocarbon plume, to estimate the mass fluxes and draw up a ranked list of the main contamination sources. A numerical flow model was implemented to support the IPT design and to interpret the results. This study revealed low-level trichloroethylene contamination (concentration below 8 μg/l), tetrachloroethylene contamination (mean concentration up to 500 μg/l) and a mass flow rate of about 300 g/day. Through the application of the IPT method, the mean contaminant concentrations, the spatial distribution of concentration values along the control planes, and the total contaminant mass flow rates were evaluated, and the investigation area was reduced for further and deeper investigation activities.

  4. Source Apportionment of PM10-Bound Polycyclic Aromatic Hydrocarbons by Positive Matrix Factorization in Córdoba City, Argentina.

    PubMed

    Amarillo, Ana C; Mateos, Ana C; Carreras, Hebe

    2017-04-01

    The composition and concentration of polycyclic aromatic hydrocarbons (PAHs) adsorbed on particles smaller than 10 microns (PM10) were analyzed in an urban area during a 2-year period from August 2011 to August 2013. Diagnostic ratios (DR) and positive matrix factorization (PMF) were employed to assess emission sources. To discount weather influence, a multiple linear regression model was generated and also a photodecomposition index was calculated for each sample. Despite the fact that mean PM10 levels showed a similar pattern all around the year, majority of PAHs showed higher concentrations during the cold than the warm period, indicating a strong seasonal variation. A 38% of PAHs variation could be explained by meteorological variables, with wind speed, wind direction, and dew point being the significant regressor variables in the model. The source apportionment of PAHs was performed using PMF although they are photosensitive compounds. The sampling period was separated in warm and cold seasons according to a photodecomposition index and cold period was used. Also, DR were calculated. DR as well as PMF analysis suggested that both gasoline and diesel vehicular emissions are the main PAHs emission sources in this urban area.

  5. Sources of polycyclic aromatic hydrocarbons in marine sediments from southern and northern areas of the Norwegian continental shelf.

    PubMed

    Boitsov, Stepan; Petrova, Vera; Jensen, Henning K B; Kursheva, Anna; Litvinenko, Ivan; Klungsøyr, Jarle

    2013-01-01

    Variability in levels and sources of polycyclic aromatic hydrocarbons (PAH) in sediments from one large sea area off the coast of northern Norway ("North area", NA) have been compared to similar data from another large area off the coast of southern Norway ("South area", SA). Samples from NA were collected at the Norwegian continental shelf in south-western Barents Sea and north-eastern Norwegian Sea. Samples from SA were from the Norwegian Trench and the Skagerrak. Sediment cores have been dated, characterised by grain size distribution (GS) and organic carbon content (TOC), and the composition of PAH and geochemical biomarkers (alkanes and triterpanes) studied to provide an insight into the different sources of PAH. Generally, PAH levels are higher in sediments from SA compared to NA. A mixture of pyrogenic and petrogenic sources contribute to PAH levels in SA, while the contents of petrogenic PAH is negligible in surface sediments in NA. At some locations in NA, petrogenic PAH levels are elevated in the deepest sediment layers from pre-industrial times, indicating a natural input of petroleum through seepage. Occurrence of elevated levels of microbial hopanoids (hopenes) in the deepest sediment layers at some locations both in the north and the south indicate the presence of petroleum.

  6. Source attributions of hazardous aromatic hydrocarbons in urban, suburban and rural areas in the Pearl River Delta (PRD) region.

    PubMed

    Zhang, Yanli; Wang, Xinming; Barletta, Barbara; Simpson, Isobel J; Blake, Donald R; Fu, Xiaoxin; Zhang, Zhou; He, Quanfu; Liu, Tengyu; Zhao, Xiuying; Ding, Xiang

    2013-04-15

    Aromatic hydrocarbons (AHs) are both hazardous air pollutants and important precursors to ozone and secondary organic aerosols. Here we investigated 14 C6-C9 AHs at one urban, one suburban and two rural sites in the Pearl River Delta region during November-December 2009. The ratios of individual aromatics to acetylene were compared among these contrasting sites to indicate their difference in source contributions from solvent use and vehicle emissions. Ratios of toluene to benzene (T/B) in urban (1.8) and suburban (1.6) were near that of vehicle emissions. Higher T/B of 2.5 at the rural site downwind the industry zones reflected substantial contribution of solvent use while T/B of 0.8 at the upwind rural site reflected the impact of biomass burning. Source apportionment by positive matrix factorization (PMF) revealed that solvent use, vehicle exhaust and biomass burning altogether accounted for 89-94% of observed AHs. Vehicle exhaust was the major source for benzene with a share of 43-70% and biomass burning in particular contributed 30% to benzene in the upwind rural site; toluene, C8-aromatics and C9-aromatics, however, were mainly from solvent use, with contribution percentages of 47-59%, 52-59% and 41-64%, respectively.

  7. Polycyclic Aromatic Hydrocarbon Contamination in Soils of San Mateo Ixtatán, Guatemala: Occurrence, Sources, and Health Risk Assessment.

    PubMed

    Kasaraneni, Varun K; Oyanedel-Craver, Vinka

    2016-09-01

    Exposure to high concentrations of carcinogenic pollutants in soils and sediments can result in increased health risks. Determining the levels and sources of contamination in developing communities is important for helping to reduce pollution and mitigate the risk of exposure. In the Mayan community of San Mateo Ixtatán, Guatemala, 24 samples of topsoil from urban, peri-urban, and agricultural sites and six samples of river sediment were collected and analyzed for 17 polycyclic aromatic hydrocarbons (PAHs). The sum of the concentrations of these PAHs at the urban and peri-urban sites ranged from 460 to 3251 μg kg (mean, 1401 μg kg), whereas at agricultural sites the range was 350 to 2087 μg kg (mean, 1038 μg kg). Analysis to identify and apportion the source showed that the PAHs emitted from wood stoves contributed 71 and 76% of the total PAHs in urban and agricultural areas soils, respectively. The calculated incremental lifetime cancer risk due to the ingestion of soil, dermal contact, and dietary intake through corn consumption was greater than the acceptable level of 10 established by the USEPA. Our findings suggest that the residents of rural communities can be at increased cancer risk despite little or no industrial activity in the local area. Alternate domestic fuel sources should be considered to reduce the health risk in local communities.

  8. Sources and distribution of polycyclic aromatic hydrocarbons in street dust from the Chang-Zhu-Tan Region, Hunan, China.

    PubMed

    Long, Yongzhen; Dai, Tagen; Wu, Qianhong

    2013-02-01

    Street dusts collected from 20 locations in the Chang-Zhu-Tan (Changsha, Zhuzhou, and Xiangtan) region, Hunan, China, in May to July 2006, were investigated for sources of polycylic aromatic hydrocarbons (PAHs). The individual PAH concentrations were in the range of 10-4316 ng g(-1), and ∑PAHs(16) levels were in the range of 3,515-24,488 ng g(-1), with a mean of 8,760 ng g(-1). The high-molecular-weight PAHs (four to six rings), ranging from 47.51 to 82.11 %, with a mean of 74.79 %, were the dominant PAH compounds in almost all of the dusts. The isomer ratios suggested a rather uniform mixture of coal combustion and petroleum PAH sources. Factor analysis and multiple linear regression analysis indicate that the main sources of the 16 PAHs were coal combustion/vehicle exhaust, coking/petroleum, and plant combustion, with contribution rates of 50.9, 35.01, and 14.08, respectively. The spatial distributions of PAH concentrations were significantly related to the distribution of industries, traffic circulation, and farmland in this region.

  9. Source apportionment of polycyclic aromatic hydrocarbons in urban air using positive matrix factorization and spatial distribution analysis

    NASA Astrophysics Data System (ADS)

    Jang, Eunhwa; Alam, Mohammed S.; Harrison, Roy M.

    2013-11-01

    Polycyclic aromatic hydrocarbons (PAH) are currently generating a great deal of interest because of their recognised toxicity, including carcinogenicity. In this study, source apportionment (SA) has been carried out using Positive Matrix Factorisation (PMF) with a dataset of 29 individual PAH (sum of vapour and particulate forms) collected by the UK National Network between 2002 and 2006. Analysis of data from 14 urban sites revealed four major source categories corresponding to unburned petroleum, diesel combustion, wood combustion and coal combustion. When a separate set of sites known to be influenced by local industrial sources was analysed, three source categories were identified corresponding to the unburned petroleum, diesel combustion and coal combustion seen in the full data analysis. When SA data were applied to the individual sites, the estimated apportionment could be explained in terms of local emission characteristics. Unburned petroleum showed the highest contribution to the sum of PAH, averaging 51.9% across the network, but benzo(a)pyrene (BaP) was more influenced by the coal combustion source which contributed 59.5% across the entire network. At the subset of sites with local industrial influence, industry was both the main contributor to the sum of PAH (accounting for 48.4% of PAH mass) and of BaP (67.9% of mass). A spatial analysis was also conducted in which the traffic source was evaluated by the difference between a roadside and a nearby urban background site, the urban source by difference between urban background and a rural site, and the industrial source by difference between a site close to a major steelworks subtracting data from a local urban background site. This showed considerable similarity between the net urban contribution and the road traffic factor, and between the net industrial contribution and the PMF coal factor profile. In both cases the congener profiles corresponded fairly well to UK national emissions inventory data

  10. shiftNMFk 1.1: Robust Nonnegative matrix factorization with kmeans clustering and signal shift, for allocation of unknown physical sources, toy version for open sourcing with publications

    SciTech Connect

    Alexandrov, Boian S.; Lliev, Filip L.; Stanev, Valentin G.; Vesselinov, Velimir V.

    2016-07-19

    This code is a toy (short) version of CODE-2016-83. From a general perspective, the code represents an unsupervised adaptive machine learning algorithm that allows efficient and high performance de-mixing and feature extraction of a multitude of non-negative signals mixed and recorded by a network of uncorrelated sensor arrays. The code identifies the number of the mixed original signals and their locations. Further, the code also allows deciphering of signals that have been delayed in regards to the mixing process in each sensor. This code is high customizable and it can be efficiently used for a fast macro-analyses of data. The code is applicable to a plethora of distinct problems: chemical decomposition, pressure transient decomposition, unknown sources/signal allocation, EM signal decomposition. An additional procedure for allocation of the unknown sources is incorporated in the code.

  11. Estimating population exposure to ambient polycyclic aromatic hydrocarbon in the United States - Part II: Source apportionment and cancer risk assessment.

    PubMed

    Zhang, Jie; Wang, Peng; Li, Jingyi; Mendola, Pauline; Sherman, Seth; Ying, Qi

    2016-12-01

    A revised Community Multiscale Air Quality (CMAQ) model was developed to simulate the emission, reactions, transport, deposition and gas-to-particle partitioning processes of 16 priority polycyclic aromatic hydrocarbons (PAHs), as described in Part I of the two-part series. The updated CMAQ model was applied in this study to quantify the contributions of different emission sources to the predicted PAH concentrations and excess cancer risk in the United States (US) in 2011. The cancer risk in the continental US due to inhalation exposure of outdoor naphthalene (NAPH) and seven larger carcinogenic PAHs (cPAHs) was predicted to be significant. The incremental lifetime cancer risk (ILCR) exceeds 1×10(-5) in many urban and industrial areas. Exposure to PAHs was estimated to result in 5704 (608-10,800) excess lifetime cancer cases. Point sources not related with energy generation and the oil and gas processes account for approximately 31% of the excess cancer cases, followed by non-road engines with 18.6% contributions. Contributions of residential wood combustion (16.2%) are similar to that of transportation-related sources (mostly motor vehicles with small contributions from railway and marine vessels; 13.4%). The oil and gas industry emissions, although large contributors to high concentrations of cPAHs regionally, are only responsible of 4.3% of the excess cancer cases, which is similar to the contributions of non-US sources (6.8%) and non-point sources (7.2%). The power generation units pose the most minimal impact on excess cancer risk, with contributions of approximately 2.3%.

  12. Increased health risk in Bangkok children exposed to polycyclic aromatic hydrocarbons from traffic-related sources.

    PubMed

    Tuntawiroon, Jantamas; Mahidol, Chulabhorn; Navasumrit, Panida; Autrup, Herman; Ruchirawat, Mathuros

    2007-04-01

    The aim of this study is to assess potential health risk of exposure to particle-associated polycyclic aromatic hydrocarbons (PAHs) in children living in a megacity with traffic congestion such as Bangkok. The study population comprised 184 Thai schoolboys (aged 8-13 years) attending schools adjacent to high-density traffic areas in Bangkok and schools located in the provincial area of Chonburi. The ambient concentration of total PAHs at roadsides in proximity to the Bangkok schools was 30-fold greater than at roadsides in proximity to the provincial schools (30.39 +/- 5.80 versus 1.50 +/- 0.28 ng/m(3); P < 0.001). Benzo(g,h,i)perylene (BghiP), an indicator of automobile exhaust emission, was the predominant PAH. Personal exposure to total PAHs and the corresponding benzo(a)pyrene (BaP) equivalent concentrations in Bangkok schoolchildren were 3.5-fold higher than in provincial schoolchildren (4.13 +/- 0.21 versus 1.18 +/- 0.09 ng/m(3); P < 0.001 and 1.50 +/- 0.12 versus 0.43 +/- 0.05 ng/m(3); P < 0.001, respectively). The concentration of urinary 1-hydroxypyrene (1-HOP) was significantly higher in Bangkok schoolchildren. Bulky carcinogen-DNA adduct levels in peripheral lymphocytes were also significantly higher (0.45 +/- 0.03 versus 0.09 +/- 0.00 adducts/10(8) nt; P < 0.001). Finally, a significantly higher level of DNA strand breaks and a significantly lower level of DNA repair capacity were observed in Bangkok schoolchildren (P < 0.001). This study indicates that Bangkok schoolchildren exposed to a high level of genotoxic PAHs in ambient air may be more vulnerable to the health impacts associated with the exposure to genotoxic pollutants than children in provincial areas and may have increased health risks for the development of certain diseases such as cancer.

  13. Hydrocarbon pneumonia

    MedlinePlus

    Pneumonia - hydrocarbon ... Coughing Fever Shortness of breath Smell of a hydrocarbon product on the breath Stupor (decreased level of ... Most children who drink or inhale hydrocarbon products and develop ... hydrocarbons may lead to rapid respiratory failure and death.

  14. The use of conditional probability functions and potential source contribution functions to identify source regions and advection pathways of hydrocarbon emissions in Houston, Texas

    NASA Astrophysics Data System (ADS)

    Xie, Yulong; Berkowitz, Carl M.

    In this study, we demonstrate the utility of conditional probability functions (CPFs), potential source contribution functions (PSCFs), and hierarchical clustering analysis (HAC) to identify the source region and transport pathways of hydrocarbons measured at five photochemical assessment monitoring stations (PAMS) near the Houston Ship Channel from June to October 2003. In contrast to scatter plots, which only show the pair-wise correlation of species, commonality in CPF figures shows both correlation and information on the source region of the species in question. In this study, we use over 50 hourly volatile organic compound (VOC) concentrations and surface wind observations to show that VOCs with similar CPF patterns likely have common transport pathways. This was established with the multivariate technique, which uses the hierarchical clustering analysis to define clusters of VOCs having similar CPF patterns. This method revealed that alkenes, and in particular those with geometric isomers such as cis-/ trans-2-butene and cis-/ trans-2-pentene, have similar CPF patterns and hence, a common area of origin. The alkane isomers often show CPF patterns among themselves, and similarly, aromatic compounds often show similar patterns. We also show how calculated trajectory information can be used in the PSCF analysis to produce a graphic picture that identifies specific geographic areas associated with a given VOC (or other pollutant). The use of these techniques in the chemically and meteorologically complex environment of Houston, Texas, suggests its further utility in other areas with relatively simpler conditions.

  15. Concentrations, sources and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in soils of Liaohe estuarine wetland.

    PubMed

    Wang, Nannan; Lang, Yinhai; Cheng, Fangfang; Wang, Minjie

    2011-10-01

    Concentration, source, and risk of PAHs were investigated in 31 sites from surface soils of Liaohe estuarine wetland. Total PAHs concentrations ranged from 293.4 to 1735.9 ng/g with a mean of 675.4 ng/g. The 3- and 4-ring PAHs were the dominant species. The ratios of high-molecular weight PAHs to low-molecular weight PAHs and anthracene/(anthracene+phenanthrene) were calculated to apportion sources of PAHs. It was found that both pyrogenic and petrogenic PAHs sources were important. Effect range low and effect range median showed that the PAHs would occasionally cause adverse effects. The nemerow composite index revealed that about 41.9% soil sampling sites were safety; about 58.1% sites had different grades of PAHs pollution.

  16. Biosurfactant production from marine hydrocarbon-degrading consortia and pure bacterial strains using crude oil as carbon source

    PubMed Central

    Antoniou, Eleftheria; Fodelianakis, Stilianos; Korkakaki, Emmanouela; Kalogerakis, Nicolas

    2015-01-01

    Biosurfactants (BSs) are “green” amphiphilic molecules produced by microorganisms during biodegradation, increasing the bioavailability of organic pollutants. In this work, the BS production yield of marine hydrocarbon degraders isolated from Elefsina bay in Eastern Mediterranean Sea has been investigated. The drop collapse test was used as a preliminary screening test to confirm BS producing strains or mixed consortia. The community structure of the best consortia based on the drop collapse test was determined by 16S-rDNA pyrotag screening. Subsequently, the effect of incubation time, temperature, substrate and supplementation with inorganic nutrients, on BS production, was examined. Two types of BS – lipid mixtures were extracted from the culture broth; the low molecular weight BS Rhamnolipids and Sophorolipids. Crude extracts were purified by silica gel column chromatography and then identified by thin layer chromatography and Fourier transform infrared spectroscopy. Results indicate that BS production yield remains constant and low while it is independent of the total culture biomass, carbon source, and temperature. A constant BS concentration in a culture broth with continuous degradation of crude oil (CO) implies that the BS producing microbes generate no more than the required amount of BSs that enables biodegradation of the CO. Isolated pure strains were found to have higher specific production yields than the complex microbial marine community-consortia. The heavy oil fraction of CO has emerged as a promising substrate for BS production (by marine BS producers) with fewer impurities in the final product. Furthermore, a particular strain isolated from sediments, Paracoccus marcusii, may be an optimal choice for bioremediation purposes as its biomass remains trapped in the hydrocarbon phase, not suffering from potential dilution effects by sea currents. PMID:25904907

  17. Identifying Hydrocarbon Source Region Emission Signatures for Oil and Gas Facilities and Beyond Using Ambient Concentration Measurements

    NASA Astrophysics Data System (ADS)

    Nathan, B.; Lary, D. J.

    2014-12-01

    The Texas Commission on Environmental Quality (TCEQ) has fourteen stations in the Barnett Shale that take ambient concentration measurements of forty-six non-methane hydrocarbons. We gathered all measurements for the period of October 16-31, 2013, and applied Lagrangian trajectories to each air parcel that was measured, to achieve a domain filling of the Barnett region. Regular grids of concentration values for each VOC at each hour were constructed, then implemented into an unsupervised machine learning classification. This self-organizing map assigned classification numbers to each grid cell in each hourly grid, where a class number essentially corresponded with a signature of representative concentration values for all forty-six hydrocarbons. Two hundred was determined to be an appropriate number of classes for this classification. Similarly, we applied a self-organizing map to the wind speed and resultant direction measurements recorded at each station. This classification grouped together the hours in our time frame into six distinct wind regimes. Concentration class numbers were analyzed for different wind regimes, and for the whole time period. A grouping of classes with numbers in the middle-to-upper forties was discovered near and downwind of oil and gas facilities. The validity and accuracy of this method was confirmed by performing a site-by-site comparison against an independent study which analyzed the VOC concentrations at three TCEQ stations. This opened the door to expand the dataset to include other ground-based measurements of both non-methane VOC and methane concentrations, to further trace back emission sources.

  18. Identifying sediment sources and delivery mechanisms using background level polycyclic aromatic hydrocarbons in the Waiapu River watershed, New Zealand

    NASA Astrophysics Data System (ADS)

    Thompson, C. E.; Nichols, E. G.; Johnson, G.; Blair, N. E.; Leithold, E. L.; Palmer, A. S.; Baisden, W. T.

    2009-12-01

    The significant contribution of small mountainous river systems to the global fluvial sediment supply motivates investigation into the processes that influence the composition of the organic carbon that they carry. Organic matter preserved in continental margin sediments originates from terrestrial sources, such as kerogen and fresh and aged soil carbon, as well as marine sources. The identification of specific terrestrial fractions buried can facilitate interpretation of the organic geochemical record and enable reconstruction of watershed history. Carbon isotopic analyses have been used to apportion terrestrial carbon fractions preserved in marine environments; however, they have been generally limited to resolving modern C and kerogen. In this study, the use of polycyclic aromatic hydrocarbons (PAHs) to examine sediment production in the Waiapu watershed, New Zealand has been investigated. A suite of 42 alkylated and non-alkylated PAH concentrations establish chemical fingerprints for likely terrestrial sources of organic matter feeding the river and margin. Principal component analysis reveals chemical similarity between source and sink based on the degree of weathering and the relative inputs of petrogenic and pyrogenic PAHs. The primary sources of terrestrial organic matter buried over recent history on the continental shelf are Cretaceous bedrock, raw riverbank soils, and pastoral topsoils. Polytopic vector analysis of marine sediment establishes PAH end-member profiles, allowing sedimentary carbon on the shelf to be apportioned to contributing sources. These end-member model profiles confirm the PCA results, corresponding to PAH fingerprints of potential terrestrial sources including (1) bedrock composed of ancient kerogen, (2) soils from riverbank profiles that are composed of mixtures of ancient, aged, and modern carbon, and (3) topsoils typically composed of modern carbon from plant or fire-derived organic matter. Resolution of these sources suggests

  19. Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)

    NASA Astrophysics Data System (ADS)

    Kosakowski, Paweł; Wróbel, Magdalena

    2012-08-01

    Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.

  20. Atmospheric polycyclic aromatic hydrocarbon profiles and sources in pine needles and particulate matter in Dayton, Ohio, USA

    NASA Astrophysics Data System (ADS)

    Tomashuk, Timothy A.; Truong, Triet M.; Mantha, Madhavi; McGowin, Audrey E.

    2012-05-01

    Polycyclic aromatic hydrocarbons (PAHs) were measured in pine needles (passive sampling) and on high-volume particulate matter (PM) filters (active sampling) over a period of eight to ten months at two separate sites in the Dayton, Ohio, USA metropolitan area: Moraine and Yellow Springs. Total PAH concentrations for PM ranged from 77.4 μg g-1 to 837 μg g-1 (dry wt.) at both sites with high molecular weight PAHs being the predominant form that tended to be higher in concentration during the colder months. Total PAH concentrations for pine needles varied by tree species and location. With an average concentration of 4187 ng g-1, Austrian pine (Pinus nigra) needles in Moraine ranged from 2543 ng g-1to 6111 ng g-1 (dry wt.) with the lowest and highest concentrations occurring in October and August, respectively. The amount of phenanthrene was extremely high for August, 4200 ± 112, which could have resulted from the close proximity of the tree to the parking lot at a firehouse. White pine (Pinus strobus) needles in Yellow Springs had an average concentration of 384 ng g-1and ranged from 127 ng g-1 to 589 ng g-1 (dry wt.) with September and November, respectively, having the lowest and highest PAH concentrations. The 2- and 3-ring PAHs were the predominant form in P. nigra, while the 4-ring PAHs predominated in P. strobus. Total PAH concentrations in P. nigra were an order of magnitude greater than for P. strobus. A bivariate plot of BaA/(BaA + Chry) versus Flt(Flt + Pyr) allowed the PM and pine needle data to be included in the same source analysis and indicated sources of PM at both sites were biomass and/or coal combustion. This plot also suggested PAHs in Yellow Springs P. strobus originated from petroleum combustion sources, whereas PAHs in Moraine P. nigra originated from petroleum combustion with some sources more aged or remote.

  1. Physically constrained source apportionment (PCSA) for polycyclic aromatic hydrocarbon using the Multilinear Engine 2-species ratios (ME2-SR) method.

    PubMed

    Liu, Gui-Rong; Shi, Guo-Liang; Tian, Ying-Ze; Wang, Yi-Nan; Zhang, Cai-Yan; Feng, Yin-Chang

    2015-01-01

    An improved physically constrained source apportionment (PCSA) technology using the Multilinear Engine 2-species ratios (ME2-SR) method was proposed and applied to quantify the sources of PM10- and PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) from Chengdu in winter time. Sixteen priority PAH compounds were detected with mean ΣPAH concentrations (sum of 16 PAHs) ranging from 70.65 ng/m(3) to 209.58 ng/m(3) and from 59.17 ng/m(3) to 170.64 ng/m(3) for the PM10 and PM2.5 samples, respectively. The ME2-SR and positive matrix factorization (PMF) models were employed to estimate the source contributions of PAHs, and these estimates agreed with the experimental results. For the PMF model, the highest contributor to the ΣPAHs was vehicular emission (81.69% for PM10, 82.06% for PM2.5), followed by coal combustion (12.68%, 12.11%), wood combustion (5.65%, 4.45%) and oil combustion (0.72%, 0.88%). For the ME2-SR method, the highest contributions were from diesel (43.19% for PM10, 47.17% for PM2.5) and gasoline exhaust (34.94%, 32.44%), followed by wood combustion (8.79%, 6.37%), coal combustion (12.46%, 12.37%) and oil combustion (0.80%, 1.22%). However, the PAH ratios calculated for the factors extracted by ME2-SR were closer to the values from actual source profiles, implying that the results obtained from ME2-SR might be physically constrained and satisfactory.

  2. Spatial distribution, potential risk assessment, and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments of Lake Chaohu, China.

    PubMed

    Li, Chaocan; Huo, Shouliang; Yu, Zhiqiang; Xi, Beidou; Zeng, Xiangying; Wu, Fengchang

    2014-10-01

    Twenty-nine sediment samples were collected from Lake Chaohu, a shallow eutrophic lake in Eastern China, and were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) to determine the spatial distribution and exposure risks of PAHs. Three receptor models, the principal component analysis-multiple linear regression (PCA-MLR) model, the positive matrix factorization (PMF) model, and the Unmix model, were used in combination with the PAHs diagnostic ratios to investigate the potential source apportionment of PAHs. A clear gradient in the spatial distribution and the potential toxicity of PAHs was observed from west to east in the sediments of Lake Chaohu. ∑15PAH concentrations and the TEQ were in the range of 80.82-30 365.01 ng g(-1) d.w. and 40.77-614.03, respectively. The highest values of the aforementioned variables were attributed to urban-industrial pollution sources in the west lake region, and the levels decreased away from the river inlets. The three different models yielded excellent correlation coefficients between the predicted and measured levels of the 15 PAH compounds. Similarly, source apportionment results were derived from the three receptor models and the PAH diagnostic ratios, suggesting that the highest contribution to the PAHs was from coal combustion and wood combustion, followed by vehicular emissions. The PMF model yielded the following contributions to the PAHs from gasoline combustion, diesel combustion, unburned petroleum emissions, and wood combustion: 34.49, 24.61, 16.11, 13.01, and 11.78 %, respectively. The PMF model produced more detailed source apportionment results for the PAHs than the PCA-MLR and Unmix models.

  3. Ordovician petroleum source rocks and aspects of hydrocarbon generation in Canadian portion of Williston basin

    SciTech Connect

    Osadetz, K.G.; Snowdon, L.R.

    1988-07-01

    Accumulation of rich petroleum source rocks - starved bituminous mudrocks in both the Winnipeg Formation (Middle Ordovician) and Bighorn Group (Upper Ordovician) - is controlled by cyclical deepening events with a frequency of approximately 2 m.y. Tectonics control both this frequency and the location of starved subbasins of source rock accumulation. Deepening cycles initiated starvation of offshore portions of the inner detrital and medial carbonate facies belts. Persistence of starved offshore settings was aided by marginal onlap and strandline migration in the inner detrital facies belt, and by low carbonate productivity in the medial carbonate facies belt. Low carbonate productivity was accompanied by high rates of planktonic productivity. Periodic anoxia, as a consequence of high rates of planktonic organic productivity accompanying wind-driven equatorial upwellings, is the preferred mechanism for suppressing carbonate productivity within the epeiric sea. The planktonic, although problematic, form Gloecapsamorpha prisca Zalesskey 1917 is the main contributing organism to source rock alginites. A long-ranging alga (Cambrian to Silurian), it forms kukersites in Middle and Upper Ordovician rocks of the Williston basin as a consequence of environmental controls - starvation and periodic anoxia. Source rocks composed of this organic matter type generate oils of distinctive composition at relatively high levels of thermal maturity (transformation ratio = 10% at 0.78% R/sub o/). In the Canadian portion of the Williston basin, such levels of thermal maturity occur at present depths greater than 2950 m within a region of geothermal gradient anomalies associated with the Nesson anticline. Approximately 193 million bbl (30.7 x 10/sup 6/ m/sup 3/) of oil has been expelled into secondary migration pathways from thermally mature source rocks in the Canadian portion of the basin.

  4. Identification and quantification of biomarkers and polycyclic aromatic hydrocarbons (PAHs) in an aged mixed contaminated site: from source to soil.

    PubMed

    Kao, Nien-Hsin; Su, Ming-Chien; Fan, Jheng-Rong; Chung, Ying-Yung

    2015-05-01

    The sources of the spill and the contaminated soils of an aged oil spill contaminated site with unknown mixed pollutants were investigated by using a set of developed forensic chemical procedures which include analysis of oil products, site investigation, gas chromatography/mass spectrometry (GC/MS) screening, biomarker identification, and finally, the confirmation of pollutants. Adamantanes (17 compounds), 10 bicyclic sesquiterpanes, 6 newly detected compounds, 16 polycyclic aromatic hydrocarbons, and 10 alkylated naphthalenes compounds in several gasoline, diesel oil samples, and contaminated soil samples were examined and quantified. GC/MS method, retention indices, relative response factors, and diagnostic ratio were used to identify and quantify pollutant compounds. The study revealed the key factors for distinguishing among gasoline and diesel oil products in the market, created a new set of retention indices for 10 bicyclic sesquiterpane compounds, and discovered 6 quantifiable compounds in analysis of fresh oil products. The suggested diagnostic ratios for BSs and the new compounds in the analysis of the biomarker show the differences among diesel products, link between the source of pollutants with contaminated soil, and the recognition of the signs of an aged spill, and the indications of weathering effects.

  5. Compound-specific stable carbon isotopic composition of petroleum hydrocarbons as a tool for tracing the source of oil spills.

    PubMed

    Li, Yun; Xiong, Yongqiang; Yang, Wanying; Xie, Yueliang; Li, Siyuan; Sun, Yongge

    2009-01-01

    With the increasing demand for and consumption of crude oils, oil spill accidents happen frequently during the transportation of crude oils and oil products, and the environmental hazard they pose has become increasingly serious in China. The exact identification of the source of spilled oil can act as forensic evidence in the investigation and handling of oil spill accidents. In this study, a weathering simulation experiment demonstrates that the mass loss of crude oils caused by short-term weathering mainly occurs within the first 24h after a spill, and is dominated by the depletion of low-molecular weight hydrocarbons (source of an oil spill, particularly for weathered oils or those with a relatively low concentration or absence of sterane and terpane biomarkers.

  6. Sources, distribution and risk assessment of polycyclic aromatic hydrocarbons in the mangrove sediments of Thane Creek, Maharashtra, India.

    PubMed

    Sukhdhane, K S; Pandey, P K; Vennila, A; Purushothaman, C S; Ajima, M N O

    2015-05-01

    The sources, distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) were investigated in the mangrove sediments of Trombay and Vashi, along the Thane Creek, Maharashtra, India, for a period of 6 months. The results showed that the concentration of Ʃ15 PAHs ranged from 902.58 to 1643.60 and from 930.69 to 1158.30 ng g(-1) in Trombay and Vashi, respectively. Trombay showed significantly higher PAH concentration (p < 0.05) than Vashi. The four carcinogenic PAHs, (benzo(b)fluorathene, benzo(k)fluorathene, Indeno(1,2,3-cd)pyrene and dibenz(a,h)anthracene) accounted for maximum concentration of the total PAHs. Specific PAH diagnostic indices and the molecular index indicated the presence of both pyrolytic and petrogenic sources with the predominance of pyrolytic origin. A positive correlation (r = 0.736, p < 0.05) existed between the benzo(k)fluorathene level and total PAHs, suggesting the use of this compound as a potential molecular marker for PAH pollution in mangrove sediment. Assessments of potential environmental risks associated with PAHs in this study revealed that the sediment was moderately polluted with high molecular weight PAHs. The study reports the baseline data that can be used for regular monitoring of contamination level considering the heavy industrialization and urbanization along the creek and its coastal region.

  7. Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition

    NASA Astrophysics Data System (ADS)

    Lv, Yan; Li, Xiang; Xu, Ting Ting; Cheng, Tian Tao; Yang, Xin; Chen, Jian Min; Iinuma, Yoshiteru; Herrmann, Hartmut

    2016-03-01

    In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012-2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4-2.1 µm) and another mode peak in the coarse-particle size range (3.3-9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above -1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h-1. The highest lifetime cancer risk (LCR) was estimated at 1.5 × 10-6, which exceeded the unit risk of 10-6. The LCR values presented here were mainly influenced by accumulation mode PAHs which came from biomass burning (24 %), coal combustion (25 %), and vehicular emission (27 %). The present study provides us with a mechanistic understanding of the particle size distribution of PAHs and their transport in the human respiratory system, which can help develop better source control strategies.

  8. Source analysis of particulate-phase polycyclic aromatic hydrocarbons in an urban atmosphere of a Northern City in China

    SciTech Connect

    Yinchang Feng; Guoliang Shi; Jianhui Wu; Yuqiu Wang; Tan Zhu; Shugui Dai; Yiqiang Pei

    2007-02-15

    Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at six sampling sites in the heating (February to March 2001) and nonheating (August to September 2001) periods in an industrial city in Northern China. Thirteen PAHs were measured. The total average concentrations (nanograms per meter cubed) of PAHs ranged between 78.93 and 214.63 during the heating period and from 31.48 to 102.26 in the nonheating period. Benzo(a)pyrene occurred at the highest level at a site near an industrial area but occurred at low concentrations far from the city center and industrial areas. In addition, ambient PAH profiles were studied. The five and six-ring species occurred in high fractions at the sampling site. By diagnostic ratio analysis, the major source at each sampling site in the city was coal combustion in the heating period; in the nonheating period, the major sources were relatively complex. Finally, the similarities among the six regions were assessed by principal component analysis, cluster analysis, and coefficient of divergence. These multivariate statistical analyses produced similar results, which agreed with the results from the diagnostic ratio analysis. 47 refs. 5 figs., 3 tabs.

  9. Source identification and health risk of polycyclic aromatic hydrocarbons associated with electronic dismantling in Guiyu town, South China.

    PubMed

    Zhang, Delin; An, Taicheng; Qiao, Meng; Loganathan, Bommanna G; Zeng, Xiangying; Sheng, Guoying; Fu, Jiamo

    2011-08-15

    In this study the concentrations and distribution of sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated in gas and total suspended particle (TSP) samples collected during daytime and night time. The sampling locations included an electronic waste dismantling workshop (EW), a plastic recycling workshop (PW) and a waste incineration field (WF) in Guiyu, China. A large residential area (RA) in this region was used as a control site. In the daytime, the highest concentration was found at WF (1041 ng m(-3)); while in the night time the highest concentration was found outside of EW (744 ng m(-3)). Comparison between work hours (daytime) and rest hours (night time) displayed that the total PAHs (gas+particulate phase) concentrations and the percentages of PAHs associated with TSP were higher at night than those in the daytime in all sampling workshops except WF. Source diagnostic-ratio analysis revealed that unwanted materials and smoldering honeycomb coals were the main sources of PAHs in EW, WF and PW. Benzo[a]pyrene equivalent [BaPeq] concentrations calculated by using the toxic equivalent factors [TEFs] suggested that the occupational exposure levels were not significantly high when compared with other occupational exposure. Additionally, our study suggested that the smoldering of unwanted materials could produce much more toxic PAHs compounds.

  10. Occurrence and Source Appraisal of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Waters of the Almendares River, Cuba.

    PubMed

    Santana, Jorge Luis; Massone, Carlos German; Valdés, Michel; Vazquez, Rene; Lima, Lázaro Antonio; Olivares-Rieumont, Susana

    2015-08-01

    In this work, 14 polycyclic aromatic hydrocarbons (PAHs) included in the United States Environmental Protection Agency pollutant priority list were analyzed in the surface water of the upper urbanized part of Almendares River, the most important water course in Havana, Cuba. Surface water from five sampling sites was collected at the end of dry season and analyzed by high-performance liquid chromatography-fluorescence detection method after solid phase extraction procedure. Total PAHs concentrations varied from 836 to 15 811 ng L(-1) with a geometric mean value of 2512 ng L(-1). PAH typology was dominated by low molecular-weight PAHs (2- to 3-ring components). Pollutant source appraisal was determined by diagnostic ratios method in five sampling sites. Factor analysis of normalized samples was used to concentration identified two factors as the main significant pollutant sources and to cluster similar sampling sites corresponding to petrogenic and combustion inputs, respectively. Ecological risks were considered. For animal aquatic life, acute toxicity values exceed the permissible values in the more-polluted sampling sites.

  11. Aliphatic and polycyclic aromatic hydrocarbons (PAHs) in soils of the northwest Qinling Mountains: Patterns, potential risk and an appraisal of the PAH ratios to infer their source.

    PubMed

    Liu, Yanhong; Wu, Yingqin; Xia, Yanqing; Lei, Tianzhu; Tian, Chuntao; Hou, Xiaohuan

    2017-03-21

    Surface soils from the tourist areas of the northwest Qinling Mountains were analyzed to determine the concentrations, probable sources and potential risks of hydrocarbons. Concentrations of aliphatic and aromatic hydrocarbons ranged from 4.18 to 3240 ng g(-1) and 0.0462 to 101 ng g(-1) dry weight, respectively. The extent of soil contamination by hydrocarbons was generally typified by unpolluted to slightly polluted levels. The incremental lifetime cancer risks (ILCRs) for exposure to soil-borne PAHs indicated complete safety for tourists. Early diagenesis of natural products, bacteria activities and petroleum were the three main sources of aliphatic hydrocarbons, while the transport of air pollutants from pyrolytic processes was the main origin of PAHs. Because the photochemical reaction of PAHs in the atmosphere would produce lower ratios for Ant/(Ant + Phe), BaA/(BaA + Chr) and IcdP/(IcdP + BghiP), but a higher ratio for Fla/(Fla + Pyr), the source classification highly depended on the diagnostic ratios chosen. The plot of ΣCOM/Σ13PAH vs. ΣLMW/ΣHMWPAH provide additional information to distinguish the origins of PAHs, and it showed a cluster of pyrogenic sources except for sample JFS-8. Four sources were resolved by principal component analysis: (1) a low temperature pyrogenic process related to the use of fossil fuel and biomass, such as charcoal, straw and wood, which contributes 63.1% of the measured PAHs; (2) the potential contribution of diagenetic processes, contributing 18.4%; (3) traffic emissions, contributing 9.27%; and (4) bioconversion/bacterial action, contributing 5.82%. Additionally, there was a good exponential relationship (r(2) = 0.969) between the natural n-alkanes ratio (NAR) and carbon preference index for C23-C35 (CPI23-35) for all samples, which is of great use for the determination of the origins of aliphatic hydrocarbon.

  12. Global prediction of continuous hydrocarbon accumulations in self-sourced reservoirs

    USGS Publications Warehouse

    Eoff, Jennifer D.

    2012-01-01

    This report was first presented as an abstract in poster format at the American Association of Petroleum Geologists (AAPG) 2012 Annual Convention and Exhibition, April 22-25, Long Beach, Calif., as Search and Discovery Article no. 90142. Shale resource plays occur in predictable tectonic settings within similar orders of magnitude of eustatic events. A conceptual model for predicting the presence of resource-quality shales is essential for evaluating components of continuous petroleum systems. Basin geometry often distinguishes self-sourced resource plays from conventional plays. Intracratonic or intrashelf foreland basins at active margins are the predominant depositional settings among those explored for the development of self-sourced continuous accumulations, whereas source rocks associated with conventional accumulations typically were deposited in rifted passive margin settings (or other cratonic environments). Generally, the former are associated with the assembly of supercontinents, and the latter often resulted during or subsequent to the breakup of landmasses. Spreading rates, climate, and eustasy are influenced by these global tectonic events, such that deposition of self-sourced reservoirs occurred during periods characterized by rapid plate reconfiguration, predominantly greenhouse climate conditions, and in areas adjacent to extensive carbonate sedimentation. Combined tectonic histories, eustatic curves, and paleogeographic reconstructions may be useful in global predictions of organic-rich shale accumulations suitable for continuous resource development. Accumulation of marine organic material is attributed to upwellings that enhance productivity and oxygen-minimum bottom waters that prevent destruction of organic matter. The accumulation of potential self-sourced resources can be attributed to slow sedimentation rates in rapidly subsiding (incipient, flexural) foreland basins, while flooding of adjacent carbonate platforms and other cratonic highs

  13. [Contamination characteristics and source analysis of polycyclic aromatic hydrocarbons in multimedium in karst underground river].

    PubMed

    Lu, Li; Wang, Zhe; Pei, Jian-Guo

    2015-03-01

    In order to understand the contamination characteristics of PAHs in different environmental mediums of karst underground river, the authors chose the Qingshuiquan underground river as the study object. Based on the data of air, groundwater, sediment and soil samples collected during the same period from 2013 to 2014, contrastive analysis was conducted in light of the component spectra, the distribution features and the characteristic ratios as well as the chemical and physical properties of 16 kinds of PAHs. The results showed that 3 kinds of PAHs with 2-3 rings (naphthalenes, phenanthrene and fluoranthene) were dominant in the air and underground river water, which accounted for 71.66% and 54.84% of the total PAHs. And PAHs with 4-6 rings were dominant in the soil and sediment of the underground river, which accounted for 54.26% and 65.06% of the total .PAHs. The distribution of PAHs in environmental mediums along the underground river indicated that the mean concentration PAHs in upstream area was less than that of midstream, and that of midstream was less than that of downstream, because of pollution discharge and absorption. The ratios of specific PAHs indicated that the PAHs sources in upstream rural area mainly came from the combustion of grassy, wood and coal, the PAHs sources in Ganhuai village were mainly originated from petroleum, and the PAHs sources in the outlet of the underground river mainly came from both petroleum and its combustion.

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

    PubMed Central

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

    2009-01-01

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

  15. Depositional setting and hydrocarbon source potential of the Miocene Gulf of Suez syn-rift evaporites

    SciTech Connect

    Richardson, M.; Arthur, M.A.; Quinn, J.S.; Whelan, J.K.; Katz, B.J. )

    1988-08-01

    The Red Sea rift basin and its northern continuation, the Gulf of Suez, has experienced continuous deposition of marine evaporites throughout much of its development from the early Miocene to the Pliocene resulting in the accumulation of up to 5 km of evaporite strata in the rift. In this paper, the geologic history of these evaporites are discussed, along with their petroleum source rock potential. The authors hypothesize that rapid deposition of organic matter occurred during episodic storms and freshening events in which a less saline surface layer developed.

  16. Sources of C₂-C₄ alkenes, the most important ozone nonmethane hydrocarbon precursors in the Pearl River Delta region.

    PubMed

    Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Huang, Zhonghui; Li, Longfeng

    2015-01-01

    Surface ozone is becoming an increasing concern in China's megacities such as the urban centers located in the highly industrialized and densely populated Pearl River Delta (PRD) region, where previous studies suggested that ozone production is sensitive to VOC emissions with alkenes being important precursors. However, little was known about sources of alkenes. Here we present our monitoring of ambient volatile organic compounds at four representative urban, suburban and rural sites in the PRD region during November-December 2009, which experienced frequent ozone episodes. C2-C4 alkenes, whose total mixing ratios were 11-20% of non-methane hydrocarbons (NMHCs) quantified, accounted for 38-64% of ozone formation potentials (OFPs) and 30-50% of the total hydroxyl radical (OH) reactivity by NMHCs. Ethylene was the most abundant alkene, accounting for 8-15% in total mixing ratios of NMHCs and contributed 25-46% of OFPs. Correlations between C2-C4 alkenes and typical source tracers suggested that ethylene might be largely related to vehicle exhausts and industry activities, while propene and butenes were much more LPG-related. Positive Matrix Factorization (PMF) confirmed that vehicle exhaust and liquefied petroleum gas (LPG) were two major sources that altogether accounted for 52-62%, 58-77%, 73-83%, 68-79% and 73-84% for ethylene, propene, 1-butene, trans-2-butene and cis-2-butene, respectively. Vehicle exhausts alone contributed 32-49% ethylene and 35-41% propene. Industry activities contributed 13-23% ethylene and 7-20% propene. LPG instead contributed the most to butenes (38-65%) and substantially to propene (23-36%). Extensive tests confirmed high fractions of propene and butenes in LPG then used in Guangzhou and in LPG combustion plumes; therefore, limiting alkene contents in LPG would benefit regional ozone control.

  17. Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in Shanghai: the spatio-temporal variation and source identification

    NASA Astrophysics Data System (ADS)

    Cheng, Chen; Bi, Chunjuan; Wang, Dongqi; Yu, Zhongjie; Chen, Zhenlou

    2017-01-01

    This study investigated the dry and wet deposition fluxes of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Shanghai, China. The flux sources were traced based on composition and spatio-temporal variation. The results show that wet deposition concentrations of PAHs ranged from 0.07 to 0.67 mg·L-1 and were correlated with temperature (P<0.05). Dry deposition of PAHs concentrations ranged from 3.60-92.15 mg·L-1 and were higher in winter and spring than in summer and autumn. The annual PAH average fluxes were 0.631 mg·m-2·d-1 and 4.06 mg·m-2·d-1 for wet and dry deposition, respectively. The highest wet deposition of PAH fluxes was observed in summer, while dry deposition fluxes were higher in winter and spring. Atmospheric PAHs were deposited as dry deposition in spring and winter, yet wet deposition was the dominant pathway during summer. Total atmospheric PAH fluxes were higher in the northern areas than in the southern areas of Shanghai, and were also observed to be higher in winter and spring. Annual deposition of atmospheric PAHs was about 10.8 t in across all of Shanghai. Wet deposition of PAHs was primarily composed of two, three, or four rings, while dry deposition of PAHs was composed of four, five, or six rings. The atmospheric PAHs, composed of four, five, or six rings, primarily existed in the form of particulates. Coal combustion and vehicle emissions were the dominant sources of PAH in the observed area of downtown Shanghai. In suburban areas, industrial pollution, from sources such as coke oven, incinerator, and oil fired power plant, was as significant as vehicle emissions in contributing to the deposition of PAHs.

  18. Sources of polycyclic aromatic hydrocarbons in sediments of the Bharalu River, a tributary of the River Brahmaputra in Guwahati, India.

    PubMed

    Hussain, Karishma; Balachandran, S; Rafiqul Hoque, Raza

    2015-12-01

    Analysis of riverine sediments offers important information regarding anthropogenic activities in the adjacent watershed. In this study, we provide polycyclic aromatic hydrocarbon (PAH) levels, their possible sources and potential hazards in the Bharalu tributary of the Brahmaputra River flowing through Guwahati city in India. The USEPA's 16 priority PAHs were determined in river bank sediments during two distinct seasons viz. pre- and post-monsoon. The ∑PAHs concentrations varied between 338 and 23,100 ng g(-1) during post-monsoon and between 609 and 8620 ng g(-1) during pre-monsoon. Mean benzo(a)pyrene (BaP) levels were between 17.8 ± 12 and 21.9 ± 27 ng g(-1) during post- and pre-monsoon seasons respectively. Spatial variations were observed. Interestingly, bank sediment samples from the sites near the confluence of the Bharalu River with the Brahmaputra River were found to have maximum concentrations of PAHs during post-monsoon season. The profile of the PAHs was dominated by 3-, 4- and 6-ring compounds. We estimated hazards of PAHs as RQ∑PAHs, which showed seasonal variation: 3 times higher during post-monsoon than pre-monsoon. 3-and 4-ring PAHs were the major PAHs of concern. The Bharalu River sediment was found to pose medium to high hazards to ecosystem. The individual PAHs including Acy, Phen and Pyr were observed with RQ(MPCs) value >1 indicating severe hazards during post-monsoon and pre-monsoon season. A very high percentage of coefficient of variation (CV) for PAHs during post-monsoon also revealed great variation in hazards and sources in this season. The diagnostic ratios indicated both petrogenic and pyrogenic origin of the PAHs. The pyrogenic contributions were mainly attributed to emissions from diesel, gasoline and wood combustion which are mainly from anthropogenic sources.

  19. Characterization and source assessment of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in sediments of the Fosu lagoon, Ghana

    SciTech Connect

    Gilbert, E.; Dodoo, D.K.; Okai-Sam, F.; Essuman, K.; Quagraine, E.K.

    2006-12-15

    The first results ever obtained on polycyclic aromatic hydrocarbon (PAHs) concentrations in the Fosu lagoon surface sediments are presented together with corresponding heavy metal (Fe, Mn, Cd, Zn and Ni) concentrations. Samples collected on a monthly basis from November 2003-April 2004 (heavy metals) and December 2003-January 2004 (PAHs) at 8 locations, representing different anthropogenic sources of contamination to the lagoon, were analyzed. Concentrations of Cd and Ni in the lagoon sediment suggest greater contamination to the lagoon from industrial activities in the vicinity of the lagoon; 50% of the sediment samples exceeded some established sediment Cd guidelines for the protection of aquatic lives. Then, 15 PAHs were detected among the sediments from the different locations and the compositional pattern in decreasing order was 3-ring {gt} 5-ring {gt} 4-ring {gt} 6-ring {gt} 2-ring PAH compounds. {Sigma} PAH concentrations in the sediment samples ranged from 254 to 558 mg/kg, with a mean of 359.4 mg/kg. Two distinct areas were identified to be a major source of anthropogenic load of both heavy metals and PAH; the mechanical shop in the northeastern sector of the lagoon is the main location for the input of Cd and it's associated PAH compounds (e.g., acenapthylene, acenaphthene, naphthalene and benzo(a)fluoranthene) and to a lesser extent Ni. Both combustion and petroleum sources may account for PAH loads from this area. The residential area in the northern sector is responsible for high loads of Mn and its associated PAH compounds (e.g., phenanthrene, benzo(a)pyrene and anthracene). These chemicals seem to enter the lagoon mainly by the combustion of especially wood or coal.

  20. Apportionment of polycyclic aromatic hydrocarbon sources in lower Fox River, USA, sediments by a chemical mass balance model

    SciTech Connect

    Su, M.C.; Christensen, E.R.; Karls, J.F.; Kosuru, S.; Imamoglu, I.

    2000-06-01

    Four sediment cores were collected from the lower Fox River, Wisconsin, USA, to identify possible sources of polycyclic aromatic hydrocarbons (PAHs) using a chemical mass balance model. The cores, which were obtained in 1995 from areas close to Green Bay, Wisconsin, USA, had total PAH concentrations between 19.3 and 0.34 ppm. To determine historical trends of PAH inputs, {sup 210}Pb and {sup 137}Cs dating was used, and elemental carbon particle analysis was done to characterize particles from the combustion of coal, wood, and petroleum. Source fingerprints were taken from the literature. Their results indicate that coke oven emissions, highway dust, coal gasification, and wood burning are likely sources of PAHs in the lower Fox River. Coke oven emissions are in the range of 40 to 90% of total PAHs, and this fraction decreases from 1930 to 1990, except in core Fox River-A (FR-A). The overall highway dust (HWY) contribution is between 10 and 75%, and this fraction increases from 1930 to present, except in core FR-A. The wood burning (WB) contribution is less than 7% in cores FR-B, FR-C, and FR-D. In core FR-A, a maximum ({approximately}23%) is found around 1960. The contribution of wood burning has changed from less than 6% in 1950 to between 3 and 10% in 1995. Evidence of aerobic biodegradation or photolysis in the sediment of phenanthrene, with a half-life of approximately 0.5 years has been found at the site of core FR-D, which is the shallowest (1.1 m) of the four core sites.

  1. Identifying source correlation parameters for hydrocarbon wastes using compound-specific isotope analysis.

    PubMed

    Hough, Rupert L; Whittaker, Martin; Fallick, Anthony E; Preston, Tom; Farmer, John G; Pollard, Simon J T

    2006-10-01

    A preliminary evaluation of compound-specific isotope analysis (CSIA) as a novel, alternative method for identifying source correlation compounds in soils contaminated with residual heavy or weathered petroleum wastes is presented. Oil-contaminated soil microcosms were established using soil (sandy-loam, non-carbonaceous cley) amended with ballast-, crude- or No.6 fuel oil. Microcosms were periodically sampled over 256 days and delta(13)C values (which express the ratio of (13)C to (12)C) determined at each time point for five n-alkanes and the isoprenoid norpristane using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Although some temporal variation was observed, no significant temporal shifts in the delta(13)C values for the five n-alkanes were measured in all three oils. Isoprenoid isotope ratios (delta(13)C) appeared to be least affected by biotransformation, especially in the No.6 fuel oil. The research suggests that the delta(13)C of isoprenoids such as norpristane, may be of use as source correlation parameters.

  2. Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis.

    PubMed

    Deng, Wei; Li, Xian Guo; Li, Sheng Yong; Ma, Yan Yan; Zhang, Da Hai

    2013-05-15

    Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) have been quantified for surface sediments collected from the East China Sea (ECS). Our results showed that relatively high levels of PAHs and AHs occurred in both the inner and outer mud areas, while their concentrations at the control site were much lower. AHs for all samples were dominated by the unresolved complex mixture (UCM). Results from diagnostic ratios revealed that sedimentary PAHs were mainly originated from mixed combustion residues of biomass, coal, and petroleum. Combustion residues of petroleum and oil were responsible for the presence of high AHs concentrations. We also conducted factor analysis (FA) to further characterize the PAH and AH sources. Four factors were identified based on the loading of components and attributed to coal and wood combustion (Factor 1), traffic-related sources (Factor 2), petrogenic source (Factor 3) and natural gas combustion (Factor 4).

  3. Hydrocarbon source potential of the Santiago Formation, Oriente Basin, SE of Ecuador

    NASA Astrophysics Data System (ADS)

    Gaibor, J.; Hochuli, J. P. A.; Winkler, W.; Toro, J.

    2008-03-01

    The Santiago Formation (Late Hettangian-Sinemurian), described in the area of Santiago in the Oriente Basin of eastern Ecuador, consists of three distinct sedimentary members. The Santiago River Member is composed of limestones and calcareous sandstones. The Yuquianza Member is a monotonous sequence of black shales. The Patuca Member consists of a sequence of sandstones, greywackes, and shales, intercalated with lava flows and dikes. The fine-grained sediments of the three members are characterized by a high content of particulate organic matter (POM). Palynofacies and rock-eval analyses indicate the predominance of kerogen types II and III, with HI values that indicate a moderate to low source potential. At the type locality, the organic matter is thermally mature and locally overmatures.

  4. Constraining the source of chlorinated hydrocarbons detected on Mars with the SAM experiment onboard Curiosity

    NASA Astrophysics Data System (ADS)

    Belmahdi, I.; Buch, A.; Szopa, C.; Freissinet, C.; Glavin, D.; François, P.; Coll, P.; Eigenbrode, J.; Navarro-Gonzalez, A. R.; Dequaire, T.; Millan, M.; Tenturier, S.; Bonnet, J. Y.; Mahaffy, P.; Cabane, M.

    2015-10-01

    Organic molecules have been at the origin of the prebiotic chemistry that led to the emergence of life on Earth. Therefore, they are one of the key ingredients required to assess the habitability in environments of the solar system. On Mars, no endogenous organics were found until very recently (1) whereas they are expected to be present in the soil, either because they were kept safe in rocks since the early history of the planet, or because they are still brought to the Mars surface by exogenous sources. Because of their importance for astrobiology, efforts are still ongoing to search for these species in the Gale crater by the Curiosity rover, and especially the SAM experiment on its board.

  5. Polycyclic aromatic hydrocarbons (PAHs) associated with fine particulate matters in Nanjing, China: Distributions, sources and meteorological influences

    NASA Astrophysics Data System (ADS)

    He, Jiabao; Fan, Shuxian; Meng, Qingzi; Sun, Yu; Zhang, Jian; Zu, Fan

    2014-06-01

    A study of 16 polycyclic aromatic hydrocarbons (PAHs) associated with fine particulate matters at suburban and urban sites in Nanjing was carried out each season from November 2009 to July 2010. At the suburban and urban sites, the concentrations of total PAHs (T-PAHs) were in the ranges of 30.76-102.26 ng/m3 and 25.92-90.80 ng/m3, respectively. This paper elucidates the distributions, sources of PAHs and meteorological influences: 1) PAHs concentrations at the two sites were close to each other and similarity between PAHs profiles of the two sites indicated they had common sources, which were attributed to the combined effect of regional transport and local emission. 2) At both sites, the profiles displayed obvious seasonal variations, as a result of the seasonality of sources and meteorological influences. The T-PAHs concentrations were in the order of winter > spring > autumn > summer. 3) Source apportionment showed vehicle exhaust (72.93-87.24%) was the greatest contributor in all seasons. The coal combustion and coke production (coal/coke) (10.02-18.63%) were identified in all but summer seasons, because of the low collection efficiency of PAHs markers of coal/coke under high temperature. For autumn, biomass burning (10.58%) was an extra contributor. 4) Regarding meteorological parameters, a negative effect of temperature over PAHs was confirmed, with a correlation coefficient of -0.51 (p < 0.05). Precipitation could remove PAHs to some extent. Both positive and negative correlations between PAHs concentration and wind speed in each season were analyzed in combination with air mass back-trajectories so as to evaluate the effects of regional air transport. The results showed that polluted air from ENE-S and NNW-NE brought in outside sources to the study area and played a major role in the accumulation of fine-particulate PAHs in spring and winter respectively, while clean air from southwest contributed to the dilution in summer.

  6. Source identification and sedimentary record of polycyclic aromatic hydrocarbons in Lake Bled (NW Slovenia) using stable carbon isotopes.

    PubMed

    Petrišič, Marinka Gams; Muri, Gregor; Ogrinc, Nives

    2013-02-05

    A combination of molecular and stable isotope analyses was used to trace and identify the sources of polycyclic aromatic hydrocarbons (PAH) in sediments of Lake Bled (NW Slovenia). Sediment samples were taken from two locations with contrasting depositional regimes: Zaka Bay, with permanently oxic bottom and station D, where anoxic conditions prevail throughout the year. The concentrations of PAH in surface sediments at the two locations were comparable and higher than in previous studies, reaching 4230 and 4380 ng g(-1), respectively. It was found that retene (Re) and perylene (Per) are both mainly of natural origin in Zaka Bay while, at station D, the value of δ(13)C determined at a depth of 12-14 cm in the 1950s indicated that Re was of pyrolytic origin. The distribution of δ(13)C values of other individual PAH showed that PAH input to lake sediments was of pyrolytic origin, likely dominated by coal and later in 1950s also by wood burning. PAH from vehicular emissions could also contribute to the overall isotope signatures at the depth of 12-14 cm at station D and Zaka Bay corresponding to the period 1953-1961.

  7. Measurements and source apportionment of particle-associated polycyclic aromatic hydrocarbons in ambient air in Riyadh, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Bian, Qijing; Alharbi, Badr; Collett, Jeffrey; Kreidenweis, Sonia; Pasha, Mohammad J.

    2016-07-01

    Ambient air samples were obtained in Riyadh, the capital and largest city of Saudi Arabia, during two measurement campaigns spanning September 2011 to September 2012. Sixteen particle-phase polycyclic aromatic hydrocarbons (PAH) were quantified in 167 samples. Pyrene and fluoranthene were the most abundant PAH, with average of 3.37 ± 14.01 ng m-3 and 8.00 ± 44.09 ng m-3, respectively. A dominant contribution from low molecular weight (LMW) PAH (MW < 228) suggested a large influence of industrial emissions on PAH concentrations. Monte Carlo source apportionment using diagnostic ratios showed that 80 ± 10% of the average LMW PAH concentrations were contributed by petroleum vapor emissions, while 53 ± 19% of high molecular weight (HMW) PAH were from solid fuel combustion emissions. The positive matrix factorization model estimated that oil combustion emissions dominated total PAH concentrations, accounting for on average 96%, likely due to widespread use of oil fuels in energy production (power plants and industries). Our results demonstrate the significant influence of petroleum product production and consumption on particulate-phase PAH concentrations in Riyadh, but also point to the importance of traffic and solid fuel burning, including coke burning and seasonal biomass burning, especially as they contribute to the ambient levels of HMW PAH.

  8. Concentrations and sources apportionment of polycyclic aromatic hydrocarbons in sediments from the Uganda side of Lake Victoria.

    PubMed

    Kerebba, Nasifu; Ssebugere, Patrick; Kwetegyeka, Justus; Arinaitwe, Kenneth; Wasswa, John

    2017-03-16

    This study presents the levels and possible sources of selected polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Napoleon Gulf and Murchison Bay of Lake Victoria. Sediment samples were extracted and cleaned up for PAHs using UNEP, 1992, and EPA method 3630C protocols. The analysis of sample extracts was carried out using a gas chromatograph coupled to a mass spectrometer. Fifteen congeners, mostly the high molecular weight PAHs (HPAHs) (4-6 rings) were detected. Total (∑) concentrations varied from 44.2 to 80.2 ng g(-1) dry weight (d.w.) at the Napoleon Gulf, while those at the Murchison Bay ranged from 17.0 to 55.0 ng g(-1) d.w. Statistical analysis showed no significant difference in the concentrations of PAHs among sites (p < 0.05, ANOVA). It was noted that the concentrations for most sampling sites were far below the lowest effect levels based on the Sediment Quality Guidelines, except for one station at the Napoleon Gulf. Principal component analysis and diagnostic ratios indicated that PAHs of combustion and petroleum origin were dominant and brought about mainly by atmospheric deposition.

  9. Distribution and sources of polycyclic aromatic hydrocarbons in intertidal flat surface sediments from the Yangtze estuary, China

    NASA Astrophysics Data System (ADS)

    Liu, M.; Hou, L. J.; Yang, Y.; Zou, H.; Lu, J.; Wang, X.

    2001-11-01

    Polycyclic aromatic hydrocarbons (PAHs) in surface sediments taken from intertidal flats in the Yangtze estuary and adjacent coastal areas were determined by GC-MS. The results have shown that total PAH concentration ranged from 0.263-6.372 mg/kg in tidal flat surface sediments from the study area. Mean concentration level is 1.662 mg/kg. The concentration levels of total PAHs varied dramatically with in the region. They are characteristically at maximum near sewage discharge points. Petroleum-derived contamination may be a dominant source in the study area based on the distributions of Flu/Pyr and two and three-ringed and four-ringed congeners in surface sediments. A pyrolytic origin was responsible for higher PAH concentration levels at three sampling sites. The degree of sediment contamination by PAHs in the study area is low to moderate in comparison with other estuarine and tidal flat surface sediments elsewhere. However, anthracene and fluorene exceed the effects of low range (ER-L) values, showing a primary potential impact for the Yangtze estuarine tidal flat ecosystem.

  10. Vehicle traffic as a source of particulate polycyclic aromatic hydrocarbon exposure in the Mexico City metropolitan area.

    PubMed

    Marr, Linsey C; Grogan, Lisa A; Wöhrnschimmel, Henry; Molina, Luisa T; Molina, Mario J; Smith, Thomas J; Garshick, Eric

    2004-05-01

    Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City's roadways range from 60 to 910 ng m(-3), averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elemental carbon (EC) concentrations are correlated because they both originate during the combustion process. Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging. These results indicate that exposure to vehicle-related PAH emissions on Mexico City's roadways may present an important public health risk.

  11. Concentrations, Source and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soils from Midway Atoll, North Pacific Ocean

    PubMed Central

    Yang, Yuyi; Woodward, Lee Ann; Li, Qing X.; Wang, Jun

    2014-01-01

    This study was designed to determine concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil samples collected from Midway Atoll and evaluate their potential risks to human health. The total concentrations of 16 PAHs ranged from 3.55 to 3200 µg kg−1 with a mean concentration of 198 µg kg−1. Higher molecular weight PAHs (4–6 ring PAHs) dominated the PAH profiles, accounting for 83.3% of total PAH mass. PAH diagnostic ratio analysis indicated that primary sources of PAHs in Midway Atoll could be combustion. The benzo[a]pyrene equivalent concentration (BaPeq) in most of the study area (86.5%) was less than 40 µg kg−1 BaPeq and total incremental lifetime cancer risks of PAHs ranged from 1.00×10−10 to 9.20×10−6 with a median value of 1.24×10−7, indicating a minor carcinogenic risk of PAHs in Midway Atoll. PMID:24466100

  12. Polycyclic Aromatic Hydrocarbons (PAHs) in Indoor Dusts of Guizhou, Southwest of China: Status, Sources and Potential Human Health Risk

    PubMed Central

    Li, Baizhan

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed for 136 indoor dust samples collected from Guizhou province, southwest of China. The ∑18PAHs concentrations ranged from 2.18 μg•g-1 to 14.20 μg•g-1 with the mean value of 6.78 μg•g-1. The highest Σ18PAHs concentration was found in dust samples from orefields, followed by city, town and village. Moreover, the mean concentration of Σ18PAHs in indoor dust was at least 10% higher than that of outdoors. The 4–6 rings PAHs, contributing more than 70% of ∑18PAHs, were the dominant species. PAHs ratios, principal component analysis with multiple linear regression (PCA-MLR) and hierarchical clustering analysis (HCA) were applied to evaluate the possible sources. Two major origins of PAHs in indoor dust were identified as vehicle emissions and coal combustion. The mean incremental lifetime cancer risk (ILCR) due to human exposure to indoor dust PAHs in city, town, village and orefield of Guizhou province, China was 6.14×10−6, 5.00×10−6, 3.08×10−6, 6.02×10−6 for children and 5.92×10−6, 4.83×10−6, 2.97×10−6, 5.81×10−6 for adults, respectively. PMID:25719362

  13. Distribution characteristics and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the Liao River drainage basin, northeast China.

    PubMed

    Hu, Jian; Liu, Congqiang; Zhang, Guoping; Zhang, Yanlin; Li, Siliang; Zhao, Zhiqi; Liu, Baojian; Guo, Qinjun

    2016-04-01

    The Liao River drainage basin, which is one of China's seven major rivers basins, is located in northeast China. This region is characterized by important industrial bases including steel factories and oil and chemical plants, all of which have the potential to contribute pollutants to the drainage basin. In this study, 16 polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM) in the major rivers of the Liao River drainage basin were identified and quantified by gas chromatography mass spectrometry (GC/MS). The total PAH concentrations ranged from 0.4 to 76.5 μg/g (dry weight) in SPM and 32.6 to 108 ng/L in surface water, respectively. Low-ring PAHs (including two- and three-ring PAHs) were dominant in all PAH samples, and the level of low-ring PAHs in surface water was higher than that in SPM. The proportion of two-ring PAHs was the highest, accounting for an average of 68.2 % of the total PAHs in surface water, while the level of three-ring PAHs was the highest in SPM, with an average of 66.3 %. When compared with other river systems, the concentrations of PAHs in the Liao River drainage basin were lower. Identification of the emission sources based on diagnostic ratios suggested petroleum and fossil fuel combustion were important contribution to PAHs in the study area.

  14. Polycyclic aromatic hydrocarbons (PAHs) in indoor dusts of Guizhou, southwest of China: status, sources and potential human health risk.

    PubMed

    Yang, Qin; Chen, Huaguo; Li, Baizhan

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed for 136 indoor dust samples collected from Guizhou province, southwest of China. The ∑18PAHs concentrations ranged from 2.18 μg•g-1 to 14.20 μg•g-1 with the mean value of 6.78 μg•g-1. The highest Σ18PAHs concentration was found in dust samples from orefields, followed by city, town and village. Moreover, the mean concentration of Σ18PAHs in indoor dust was at least 10% higher than that of outdoors. The 4-6 rings PAHs, contributing more than 70% of ∑18PAHs, were the dominant species. PAHs ratios, principal component analysis with multiple linear regression (PCA-MLR) and hierarchical clustering analysis (HCA) were applied to evaluate the possible sources. Two major origins of PAHs in indoor dust were identified as vehicle emissions and coal combustion. The mean incremental lifetime cancer risk (ILCR) due to human exposure to indoor dust PAHs in city, town, village and orefield of Guizhou province, China was 6.14×10-6, 5.00×10-6, 3.08×10-6, 6.02×10-6 for children and 5.92×10-6, 4.83×10-6, 2.97×10-6, 5.81×10-6 for adults, respectively.

  15. Nine years of global hydrocarbon emissions based on source inversion of OMI formaldehyde observations

    NASA Astrophysics Data System (ADS)

    Bauwens, Maite; Stavrakou, Trissevgeni; Müller, Jean-François; De Smedt, Isabelle; Van Roozendael, Michel; van der Werf, Guido R.; Wiedinmyer, Christine; Kaiser, Johannes W.; Sindelarova, Katerina; Guenther, Alex

    2016-08-01

    As formaldehyde (HCHO) is a high-yield product in the oxidation of most volatile organic compounds (VOCs) emitted by fires, vegetation, and anthropogenic activities, satellite observations of HCHO are well-suited to inform us on the spatial and temporal variability of the underlying VOC sources. The long record of space-based HCHO column observations from the Ozone Monitoring Instrument (OMI) is used to infer emission flux estimates from pyrogenic and biogenic volatile organic compounds (VOCs) on the global scale over 2005-2013. This is realized through the method of source inverse modeling, which consists in the optimization of emissions in a chemistry-transport model (CTM) in order to minimize the discrepancy between the observed and modeled HCHO columns. The top-down fluxes are derived in the global CTM IMAGESv2 by an iterative minimization algorithm based on the full adjoint of IMAGESv2, starting from a priori emission estimates provided by the newly released GFED4s (Global Fire Emission Database, version 4s) inventory for fires, and by the MEGAN-MOHYCAN inventory for isoprene emissions. The top-down fluxes are compared to two independent inventories for fire (GFAS and FINNv1.5) and isoprene emissions (MEGAN-MACC and GUESS-ES). The inversion indicates a moderate decrease (ca. 20 %) in the average annual global fire and isoprene emissions, from 2028 Tg C in the a priori to 1653 Tg C for burned biomass, and from 343 to 272 Tg for isoprene fluxes. Those estimates are acknowledged to depend on the accuracy of formaldehyde data, as well as on the assumed fire emission factors and the oxidation mechanisms leading to HCHO production. Strongly decreased top-down fire fluxes (30-50 %) are inferred in the peak fire season in Africa and during years with strong a priori fluxes associated with forest fires in Amazonia (in 2005, 2007, and 2010), bushfires in Australia (in 2006 and 2011), and peat burning in Indonesia (in 2006 and 2009), whereas generally increased fluxes

  16. Spatial and temporal variations and mobile source emissions of polycyclic aromatic hydrocarbons in Quito, Ecuador

    PubMed Central

    Brachtl, Megan V.; Durant, John L.; Perez, Carlos Paez; Oviedo, Jorge; Sempertegui, Fernando; Naumova, Elena N.; Griffiths, Jeffrey K.

    2009-01-01

    Motor vehicles are a major source of air pollution in Quito, Ecuador; however, little work has been done to characterize spatial and temporal variations in traffic-related pollutants, or to measure pollutants in vehicle emissions. We measured PAH continuously for one year at two residential sites in Quito, and PAH and traffic patterns for one week near a busy roadway. Morning rush-hour traffic and temperature inversions caused daily PAH maxima between 06:00 and 08:00. SO2, NOx, CO, and PM2.5 behaved similarly. At the residential sites PAH levels during inversions were 2–3-fold higher than during the afternoon, and 10–16-fold higher than 02:00–03:00 when levels were lowest. In contrast, at the near-roadway site, PAH concentrations were 3–6-fold higher than at the residential sites, and the effects of inversions were less pronounced. Cars and buses accounted for >95% of PAH at the near-roadway site. Near-roadway PAH concentrations were comparable to other polluted cities. PMID:19004535

  17. SOURCE APPORTIONMENT OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) INTO CENTRAL PARK LAKE, NEW YORK CITY, OVER A CENTURY OF DEPOSITION

    PubMed Central

    Yan, Beizhan; Bopp, Richard F.; Abrajano, Teofilo A.; Chaky, Damon; Chillrud, Steven N.

    2014-01-01

    Relative contributions of polycyclic aromatic hydrocarbons (PAHs) from combustion sources of wood, petroleum, and coal were computed in sediments from Central Park Lake in New York City (NY, USA) by chemical mass balance based on several reliable source indicators. These indicators are the ratio of retene to the sum of retene and chrysene, the ratio of 1,7-dimethylphenanthrene (DMP) to 1,7-DMP and 2,6-DMP, and the ratio of fluroanthene to fluroanthene and pyrene. The authors found that petroleum combustion–derived PAH fluxes generally followed the historical consumption data of New York State. Coal combustion-derived PAH flux peaked approximately in the late 1910s, remained at a relatively high level over the next 3 decades, then rapidly declined from the 1950s to the 1960s; according to historical New York State coal consumption data, however, there was a 2-peak trend, with peaks around the early 1920s and the mid-1940s. The 1940s peak was not observed in Central Park Lake, most likely because of the well-documented shift from coal to oil as the major residential heating fuel in New York City during the late 1930s. It was widely believed that the decreased PAH concentrations and fluxes in global sediments during the last century resulted from a major energy shift from coal to petroleum. The data, however, show that this shift occurred from 1945 through the 1960s and did not result in an obvious decline. The sharpest decrease, which occurred in the 1970s was not predominantly related to coal usage but rather was the result of multiple factors, including a decline in petroleum usage largely, the introduction of low sulfur–content fuel in New York City, and the introduction of emission-control technologies. PMID:24375577

  18. Source apportionment of particle-bound polycyclic aromatic hydrocarbons in Lumbini, Nepal by using the positive matrix factorization receptor model

    NASA Astrophysics Data System (ADS)

    Chen, Pengfei; Li, Chaoliu; Kang, Shichang; Yan, Fangping; Zhang, Qianggong; Ji, Zhengming; Tripathee, Lekhendra; Rupakheti, Dipesh; Rupakheti, Maheswar; Qu, Bin; Sillanpää, Mika

    2016-12-01

    Indo-Gangetic Plain (IGP) is one of the most polluted regions in the world. Despite numbers of studies conducted at urban site, few data are available at rural area. In this study, characteristics of 15 particle-bound priority polycyclic aromatic hydrocarbons (PAHs) of total suspended particles (TSPs) collected at a typical rural area (Lumbini) of IGP from April 2013 to March 2014 were reported. The results showed that annual average TSP and PAH concentrations were 209 ± 123 μg/m3 and 94.8 ± 54.6 ng/m3, respectively, which were similar to those of large cities such as Agra and Delhi in the upwind adjacent regions. Clear seasonal variation of TSP and PAH concentrations was observed, with the highest average concentration occurring in winter followed by the pre-monsoon, post-monsoon, and monsoon seasons, reflecting combined influence of source strength and monsoon circulation on PAH concentrations of Lumbini. Positive matrix factorization analysis showed that biomass combustion (50.6%) and vehicular emissions (30.4%) were first two sources of PAHs, followed by coal combustion (11.6%) and air-soil exchange (7.4%), in line with that of diagnostic molecular ratios results. Because of extensive agro-residue burning, intensive forest fires, and conducive weather conditions, contribution of biomass burning during non-monsoon season (55.7%) was higher than that of monsoon season (42.1%). The total BaP equivalent concentration (BaPeq) of particulate PAHs ranged between 2.51 and 47.3 ng/m3, was 2-40 times higher than the WHO guideline (1 ng/m3), implying local residents were at risk for adverse health effects.

  19. Concentrations of polycyclic aromatic hydrocarbons: Their potential health risks and sources at three non-urban sites in Japan.

    PubMed

    Jadoon, Waqar A; Sakugawa, Hiroshi

    2016-09-18

    This investigation was undertaken to monitor particulate polycyclic aromatic hydrocarbons (PAHs) concentrations in order to determine their emission sources and potential human health risks in remote and rural areas of Japan. Seventeen PAHs in aerosol samples collected in remote (Kamihaya), coastal (Hiki) and inland (Higashi-Hiroshima) areas of Japan during 2013-2014 were analyzed using gas chromatography/mass spectrometry. Total PAH (Σ17PAH) concentrations in aerosol samples were in the range of 0.08-6.51 ng m(-3), 0.09-4.74 ng m(-3), and 0.21-6.53 ng m(-3) at Kamihaya, Hiki, and Higashi-Hiroshima sites, with mean concentrations of 1.63, 1.18, and 2.43 ng m(-3), respectively. Significant seasonal variation in concentrations occurred at Hiki and Higashi-Hiroshima, while no significant variation occurred at Kamihaya. Ambient air temperature greatly affected PAH concentrations in Higashi-Hiroshima, but had only moderate effects in Kamihaya and Hiki. Wind direction also influenced the concentrations of PAHs. Vehicle exhaust, industrial emissions, biomass combustion, and domestic heating and cooking were identified as the main PAH emission sources using principal component analysis. Backward trajectory calculations showed that domestically generated PAHs were significant in Kamihaya and Hiki, while in Higashi-Hiroshima concentrations were mainly influenced by long-range transport. The incremental lifetime lung cancer risk had values of 3.38 × 10(-5) and 1.84 × 10(-5) at Higashi-Hiroshima and Hiki, which are greater than the US EPA acceptable level (10(-6)). Typically, 5-6-ring PAHs contributed 95% to this overall health risk, of which benzo(a)pyrene was the largest contributor, followed by dibenz(a,h)anthracene at both residential sites. Clearly, stricter guidelines for PAHs need to be implemented at these sites to protect the population.

  20. Source analysis of particulate matter associated polycyclic aromatic hydrocarbons (PAHs) in an industrial city in northeastern China.

    PubMed

    Han, Bin; Ding, Xiao; Bai, Zhipeng; Kong, Shaofei; Guo, Guanghuan

    2011-09-01

    Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at eight sampling sites during cold periods where heating is used (heating period) (February to March, 2005) and warm periods where heating is not required (non-heating periods) (August to September 2006) in the urban area of Anshan, an iron and steel city in northeastern China. Eleven PAH species were measured using GC-MS. The total average concentrations of PAHs ranged from 46.14 to 385.60 ng m(-3) in the heating period and from 5.28 to 146.40 ng m(-3) in the non-heating period. The lowest concentration of ∑PAHs was observed at Qianshan, a monitoring site far from the city and industrial area, and the highest concentration occurred in the site located at the factory area of Anshan Iron and Steel Incorporation. Moreover, ambient PAH profiles were studied and high molecular weight PAH (including 4-6 rings) species occurred in the high fractions. Toxic equivalent factors analysis gave the potential carcinogenic risks in Anshan. For the heating sampling period, BaP equivalent concentration is in the range of 41.98 to 220.83 ng m(-3), and 9.23 to 126.00 ng m(-3) for the non-heating sampling period. By diagnostic ratio analysis, traffic emission and combustion (coal or biomass) were potential sources for PAHs in Anshan. Finally, PCA results indicated the major sources were vehicle emission, steel industry emission, and coal combustion for both heating and non-heating seasons, which agreed with the results from the diagnostic ratio analysis.

  1. Determination and source identification of priority polycyclic aromatic hydrocarbons in PM2.5 in Taiyuan, China

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Xie, Jingfang; Wang, Zhentao; Zhao, Lijuan; Zhang, Hong; Li, Meng

    2016-09-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) present in PM2. 5 were analyzed in 2012 in Taiyuan (China) using high performance liquid chromatography (HPLC) with fluorescence and ultraviolet detectors. The average daily mass concentrations of ΣPAHs in different seasons ranged from 10.36 ng/m3 to 215.93 ng/m3 and had strong seasonal variation, with highest values in winter and lowest in summer. Over the whole year, PAHs appeared in the following order of frequency: 4-ring > 6-ring > 5-ring > 3-ring; in winter, the percentage of 4-ring PAHs was the highest (62.68%), while in summer, the percentages of 5-ring and 6-ring PAHs (cumulative total of 50.57%) were higher. The ratio method was employed to investigate potential source categories of PAHs in PM2.5 in Taiyuan, with data suggesting that the main PAH sources are coal and wood combustion and vehicle emissions. Finally, a risk assessment of PAHs was performed based on benzo(a)pyrene equivalent (BaPeq) values and individual cancer risk ratios, with results suggesting that the toxicity of PAHs was high during winter and spring time in Taiyuan. The values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure(Ri) for all age groups were larger than 10- 6 in spring and winter, while Ri values for male and female adults in summer and autumn were also larger than 10- 6, indicating high potential carcinogenic risk. During the same season, the ILCR of adults was greater than that of other age groups and that of females was a little higher than of males. With respect to the season, the ranking of ILCR in decreasing order was as follows: winter, spring, autumn, and summer.

  2. Distributions and source apportionment of sediment-associated polycyclic aromatic hydrocarbons (PAHs) and hopanes in rivers and estuaries of Peninsular Malaysia.

    PubMed

    Keshavarzifard, Mehrzad; Zakaria, Mohamad Pauzi; Hwai, Tan Shau; Yusuff, Ferdius Mohamat; Mustafa, Shuhaimi

    2015-06-01

    In this study, the distributions and sources of sediment-associated polycyclic aromatic hydrocarbons (PAHs) and hopanes in the Malaysian rivers and estuaries were evaluated. The concentrations of 16 USEPA PAHs varied from 225.5 to 293.9 (Perlis River), 195.2 to 481.2 (Kedah River), 791.2 to 1995.4 (Merbok River), 231.2 to 426.7 (Perak River), and 3803.2 to 7442.7 ng g(-1) (Klang River) dry weight. PAHs can be classified as moderate in the Perlis, Kedah, and Perak Rivers, moderate to high in the Merbok River, and high to very high in the Klang River. The comparison of PAHs with sediment quality guidelines (SQGs) indicates that occasionally adverse biological effects may occur from total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs at stations 1, 2, and 3 of the Klang River and from total PAHs at station 2 of the Merbok River. The diagnostic ratios of individual PAHs indicate both petrogenic and pyrogenic origin PAHs with significant dominance of pyrogenic sources in the study areas. The results suggest that Malaysian sediments had hopane ratios (C29/C30) similar to MECO suggesting MECO as a major source of the petroleum hydrocarbons found in the sediments, which is consistent with results reported in previous studies. These findings demonstrate that effective and improved environmental regulations in Malaysia have shifted the source of petroleum hydrocarbons from petrogenic to pyrogenic origin.

  3. Baseline distributions and sources of Polycyclic Aromatic Hydrocarbons (PAHs) in the surface sediments from the Prai and Malacca Rivers, Peninsular Malaysia.

    PubMed

    Keshavarzifard, Mehrzad; Zakaria, Mohamad Pauzi; Hwai, Tan Shau; Yusuff, Ferdius Ferdius Mohamat; Mustafa, Shuhaimi; Vaezzadeh, Vahab; Magam, Sami M; Masood, Najat; Alkhadher, Sadeq A A; Abootalebi-Jahromi, Fatemeh

    2014-11-15

    In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.

  4. Determination of microbial carbon sources and cycling during remediation of petroleum hydrocarbon impacted soil using natural abundance (14)C analysis of PLFA.

    PubMed

    Cowie, Benjamin R; Greenberg, Bruce M; Slater, Gregory F

    2010-04-01

    In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study

  5. Compound specific radiocarbon analysis as a tool to quantitatively apportion modern and fossil sources of polycyclic aromatic hydrocarbons in environmental matrices

    SciTech Connect

    Eglinton, T.I.: Pearson, A.; McNichol, A.P.

    1996-12-31

    The quantitative apportionment of multiple sources of toxic compounds in natural systems has been of substantial interest in recent years. Polycyclic aromatic hydrocarbons (PAHs), which represent one of the largest classes of suspected chemical carcinogens/mutagens, are one such example. The biogeochemistry of PAHs in the environment is extremely complex as a result of the multitude of potential sources (both anthropogenic and natural), differing reactivities and solubilities, and transport and depositional processes that control their provenance. PAHs sources can be broadly divided into two categories: (a) {open_quotes}Pyrogenic{close_quotes} PAHs from high-temperature processes (i.e., incomplete combustion (pyrolysis) of organic materials); (b) PAHs from lower temperature processes (i.e. uncombusted petroleum contamination). Pyrogenic PAHs can be further separated into fossil fuel (coal and petroleum) combustion sources, and biomass combustion sources (charcoal burning; cigarette smoking, forest/grass fires, barbeques etc.). Although a variety of criteria may be used to distinguish petroleum from combustion sources of polycyclic aromatic hydrocarbons (PAHs) in environmental samples, it is much more difficult to distinguish PAHs derived from modem (e.g. residential wood combustion) versus fossil fuel (e.g. coal combustion) pyrogenic sources. This paper describes results of isotope dating of a coal tar extract and and air particulate sample.

  6. Biomass fuels and coke plants are important sources of human exposure to polycyclic aromatic hydrocarbons, benzene and toluene.

    PubMed

    Fan, Ruifang; Li, Junnan; Chen, Laiguo; Xu, Zhencheng; He, Dechun; Zhou, Yuanxiu; Zhu, Yuanyuan; Wei, Fusheng; Li, Jihua

    2014-11-01

    Large amounts of carcinogenic polycyclic aromatic hydrocarbons (PAHs), benzene and toluene (BT) might be emitted from incomplete combustion reactions in both coal tar factories and biomass fuels in rural China. The health effects arising from exposure to PAHs and BT are a concern for residents of rural areas close to coal tar plants. To assess the environmental risk and major exposure sources, 100 coke plant workers and 25 farmers in Qujing, China were recruited. The levels of 10 mono-hydroxylated PAHs (OH-PAHs), four BT metabolites and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the urine collected from the subjects were measured. The 8-OHdG levels in the urine were determined to evaluate the oxidative DNA damage induced by the PAHs and BT. The results showed that the levels of the OH-PAHs, particularly those of 1-hydroxynathalene and 1-hydroxypyrene, in the farmers were 1-7 times higher than those in the workers. The concentrations of the BT metabolites were comparable between the workers and farmers. Although the exact work location within a coke oven plant might affect the levels of the OH-PAHs, one-way ANOVA revealed no significant differences for either the OH-PAHs levels or the BT concentrations among the three groups working at different work sites. The geometric mean concentration (9.17 µg/g creatinine) of 8-OHdG was significantly higher in the farmers than in the plant workers (6.27 µg/g creatinine). The levels of 8-OHdG did not correlate with the total concentrations of OH-PAHs and the total levels of BT metabolites. Incompletely combusted biomass fuels might be the major exposure source, contributing more PAHs and BT to the local residents of Qujing. The estimated daily intakes (EDIs) of naphthalene and fluorene for all of the workers and most of the farmers were below the reference doses (RfDs) recommended by the U.S. Environmental Protection Agency (EPA), except for the pyrene levels in two farmers. However, the EDIs of benzene in the workers and local

  7. Opposing seasonal trends for polycyclic aromatic hydrocarbons and PM10: Health risk and sources in southwest Mexico City

    NASA Astrophysics Data System (ADS)

    Amador-Muñoz, Omar; Bazán-Torija, S.; Villa-Ferreira, S. A.; Villalobos-Pietrini, Rafael; Bravo-Cabrera, José Luis; Munive-Colín, Zenaida; Hernández-Mena, Leonel; Saldarriaga-Noreña, H.; Murillo-Tovar, M. A.

    2013-03-01

    This study reports the measurement of polycyclic aromatic hydrocarbons (PAHs) in airborne particles ≤ 10 μm (PM10) during four years. Seasonal variation was observed for PM10 and PAH in southwest Mexico City, with major mass concentrations during the dry season (November-April). A non linear decreasing trend of PM10 was observed during this period, while a linear increase (in the four years) was obtained for benzo[a]pyrene (88 pg m- 3), phenanthrene (29 pg m- 3), fluoranthene (88 pg m- 3), and benzo[ghi]perylene (438 pg m- 3). Coronene also showed an increasing trend but it was nonlinear. This suggests that air control strategies implemented by the government contributed to maintaining PM10 under the 24 h maximum limit and resulted in a decreasing trend during this period. However, these strategies did not result in controlling some organic constituents with mutagenic and/or carcinogenic properties as it is the case of benzo[a]pyrene. The annual average of this PAH exceeded the UK recommendation. It was estimated a median (10th-90th) lifetime health risk of 7.6 (3.4-17.2) additional cases of cancer per 10 million people in this zone exists and the health risk of PAH is almost three times greater in dry seasons than it is in rainy seasons. Specific humidity, temperature and wind speed acted as cleaners for PM10 and PAH from the atmosphere. PAH diagnostic ratios and correlation and principal component analyses suggest incomplete combustion from gasoline and diesel engines as the main contributor to PAH found in southwest Mexico City, where factor 1 grouped all PAH emitted from gasoline engines during first three years. During last year, factor 1 only grouped PAH markers of diesel engines. This suggests a change of emission amounts between gasoline and diesel combustion sources or a contribution of other source(s) which changed the PAH profiles. During four years retene was always separated from factors which grouped the rest of PAH, due to its wood combustion

  8. Isotopic characterization of Polycyclic Aromatic Hydrocarbons for identification of sources and transfer mechanisms in Ile de France.

    NASA Astrophysics Data System (ADS)

    Fauches, Raphaël; Moreau-Guigon, Elodie; Alliot, Fabrice; Mendez, Mercedes; Chevreuil, Marc

    2015-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants that accumulate in the environment as mainly a result of human processes in anthropic environment. Emission of PAHs in Ile de France region is a major environmental and public health problem. Seventy percent of the Seine Watershed Rivers do not respect the requirement of the 2012 European Water Framework Directive for good chemical status due to PAHs. We study the 16 PAHs selected by the United States Environmental Protection Agency. The measurement of the ratio of stable Carbon (δ13C) and hydrogen (δ2H) isotopes may be used as a means to identify the source of PAHs. Two samplings campaign in the Seine watershed was conducted in summer and in winter during dry periods and one during rainy periods. Water and sediment were sampled from 12 locations along the Orge River (France) and classified in three categories: urban, peri-urban and rural. Extraction and purification methods have been developed and tested. This method consists on a liquid-liquid extraction and sonication extraction. The Aromatic fraction is purified and isolated on silica/alumina column before performing thin purification by using a semi-preparative High Performance Liquid Chromatography (HPLC). HPLC is used for separation of each PAH one by one. Moreover, this fractionation reduces background noise generated in part by unwanted compounds like alkanes and allows the isotopic analysis of PAH. The purity of each fraction was verified by Mass-Spectrometry Gas Chromatography in scan mode. The mean recovery of the method for all PAHs was around 80%. Isotopic analysis for carbon 13 and deuterium by Gas Chromatography-Combustion- Isotope-ratio mass spectrometry are ongoing. Beside the sampling campaign, biodegradation, hydrolysis and photolysis tests were performed. In addition, combustion testing of gasoline and diesel on an experimental device are provided to estimate the isotopic ratio of motorized vehicles in the Ile de France region.

  9. Polycyclic aromatic hydrocarbons (PAHs) concentration levels, pattern, source identification and soil toxicity assessment in urban traffic soil of Dhanbad, India.

    PubMed

    Suman, Swapnil; Sinha, Alok; Tarafdar, Abhrajyoti

    2016-03-01

    Present study was carried out to assess and understand potential health risk and to examine the impact of vehicular traffic on the contamination status of urban traffic soils in Dhanbad City with respect to polycyclic aromatic hydrocarbons (PAHs). Eight urban traffic sites and two control/rural site surface soils were analyzed and the contents of 13 priority PAHs was determined. Total PAH concentration at traffic sites ranged from 1.019 μg g(-1) to 10.856 μg g(-1) with an average value of 3.488 μg g(-1). At control/rural site, average concentration of total PAHs was found to be 0.640 μg g(-1). PAH pattern was dominated by four- and five-ring PAHs (contributing >50% to the total PAHs) at all the eight traffic sites. On the other hand, rural soil showed a predominance of low molecular weight three-ring PAHs (contributing >30% to the total PAHs). Indeno[123-cd]pyrene/benz[ghi]perylene (IP/BgP) ratio indicated that PAH load at the traffic sites is predominated by the gasoline-driven vehicles. The ratio of Ant/(Ant+Phe) varied from 0.03 to 0.44, averaging 0.10; Fla/(Fla+Pyr) from 0.39 to 0.954, averaging 0.52; BaA/(BaA+Chry) from 0.156 to 0.60, averaging 0.44; and IP/(IP+BgP) from 0.176 to 0.811, averaging 0.286. The results indicated that vehicular emission was the major source for PAHs contamination with moderate effect of coal combustion and biomass combustion. Carcinogenic potency of PAH load in traffic soil was nearly 6.15 times higher as compared to the control/rural soil.

  10. [Estimation inventory of polycyclic aromatic hydrocarbons (PAHs) from anthropogenic sources and its impacts within the Yanghe Watershed, an important water-source site of Beijing, China].

    PubMed

    Gao, Jia-Jia; Luo, Wei; Xi, Xiao-Xia

    2014-12-01

    The Yanghe Watershed, situated at the upwind of Beijing, is an important water-source site and ecologic protection barrier for Beijing and Zhangjiakou cities. The Yanghe Watershed is also a farming-pastoral transitional area and an ecologically vulnerable and sensitive region, as well as the place applying for Winter Olympic Game in 2022. Establishment of atmospheric emissions inventory of polycyclic aromatic hydrocarbons (PAHs) and identification of its sources within the Yanghe Watershed and its possible transportation paths to Beijing can help us get a better understanding of regional environmental pollution (especially air environmental pollution) in Beijing-Zhangjiakou area. In the present study, PAHs emission from different counties and cities within the Yanghe Watershed in 2012 was calculated based on the statistical data of local industries, agriculture and resident living while PAHs emission factors were estimated. According to the cluster analysis for air transport trajectories, main categories of air masses were obtained. Results indicated that total emission of PAHs in 2012 was 4.4 x 10(2) t. Coal combustion and crop-straw burning were the most important emission sources of PAHs, accounting for 76% and 16% of total emission of PAHs, respectively. Xuanhua county had the greatest emission of PAHs (49 t), followed by Xinghe (36 t), Tianzhen (32 t), Huailai (24 t) and Wanquan (15 t). In emission of 16 isomers of PAHs, the emission of high molecular weight isomers containing 4-6 rings was approximate to that of low molecular weight isomers containing 2-3 rings, accounting for approximately 50% of total emission of PAHs. Emission of PAHs had positive correlations with gross industrial production (GIP) (r = 0.96, P < 0.05) and resident income (RI) (r = 0.94, P < 0.05) and population density (PD) (r = 0.92, P < 0.05), but negatively correlated with land area (LA) (r = - 0.9, P < 0.05) and no significant correlationship with gross output value of agriculture

  11. Hydrocarbons and energy from plants: Final report, 1984-1987

    SciTech Connect

    Calvin, M.; Otvos, J.; Taylor, S.E.; Nemethy, E.K.; Skrukrud, C.L.; Hawkins, D.R.; Lago, R.

    1988-08-01

    Plant hydrocarbon (isoprenoid) production was investigated as an alternative source to fossil fuels. Because of their high triterpenoid (hydrocarbon) content of 4--8%, Euphorbia lathyris plants were used as a model system for this study. The structure of the E. lathyris triterpenoids was determined, and triterpenoid biosynthesis studied to better understand the metabolic regulation of isoprenoid production. Triterpenoid biosynthesis occurs in two distinct tissue types in E. lathyris plants: in the latex of the laticifer cells; and in the mesophyll cells of the leaf and stem. The latex has been fractionated by centrifugation, and it has been determined that the later steps of isoprenoid biosynthesis, the conversion of mevalonic acid to the triterpenes, are compartmentized within a vacuole. Also identified was the conversion of hydroxymethyl glutaryl-CoA to mevalonic acid, catalyzed by the enzyme Hydroxymethyl glutaryl-CoA Reductase, as a key rate limiting step in isoprenoid biosynthesis. At least two isozymes of this enzyme, one in the latex and another in the leaf plastids, have been identified. Environmental stress has been applied to plants to study changes in carbon allocation. Salinity stress caused a large decrease in growth, smaller decreases in photosynthesis, resulting in a larger allocation of carbon to both hydrocarbon and sugar production. An increase in Hydroxymethyl glutaryl-CoA Reductase activity was also observed when isoprenoid production increased. Other species where also screened for the production of hydrogen rich products such as isoprenoids and glycerides, and their hydrocarbon composition was determined.

  12. Genesis of oil and hydrocarbon gases within Mars and carbonaceous chondrites from our solar system: organic origin (source rocks or direct biogenic sink?)

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Prasanta K.

    2011-10-01

    The petroleum hydrocarbons (oil and gas) and kerogen macromolecules are abundant within the extraterrestrial atmospheric particles. These hydrocarbons occur as reservoir of lakes and oceans or in hydrate forms on various planets (Earth, Mars, moons of Saturn and Jupiter), asteroid belts, carbonaceous chondrites, and as solid residue within the planets or moons in the Solar System and beyond. The abundance of PAHs in the outer Solar System may indicate that the genesis of these primitive biomarker hydrocarbons may have formed abiogenically much earlier (> 5Ga) than the formation of our Solar System (~ 5 Ga). However, the origin of petroleum on Earth is overwhelmingly connected to the biogenic organic matter that is related to source rocks (thermal degradation of macromolecular kerogen). This may show a similar genesis of the kerogen macromolecules and petroleum hydrocarbons (oil and gas) within the carbonaceous chondrites (CCs), Mars, and selected moons from Saturn and Jupiter. They may be biologically and genetically related. Recent evidence of the possible presence of source rocks (organic rich black carbonaceous rocks) and associated petroleum system elements within Eberswalde and Holden areas of Mars may indicate similar terrestrial associations. Similarly, studies of Carbonaceous Chondrites using biological, petrological, SEM/EDS, and petroleum geochemical methods may also indicate the presence of source rock macromolecule within the CCs. These studies pointed out two new issues: (1) approximately, the major part of the CCs possibly originated from archaea, bacteria, and primitive algal remains; and (2) three types of temperature events affecting the petroleum generation within these carbonaceous chondrites: (i) lower temperature events (<200oC) in comets and cooler asteroids or planets (examples: Murchison, Tagish Lake, Orgueil); (ii) intermediate temperature events (200 - 300oC) as associated within the deeper section of the comets, asteroids or planets

  13. Spatial distribution and sources of heavy metals and petroleum hydrocarbon in the sand flats of Shuangtaizi Estuary, Bohai Sea of China.

    PubMed

    Yang, Xiaolong; Yuan, Xiutang; Zhang, Anguo; Mao, Yuze; Li, Qiang; Zong, Humin; Wang, Lijun; Li, Xiaodong

    2015-06-15

    The concentrations of heavy metals and petroleum hydrocarbons (PHCs) in surface sediments were investigated in the sand flats of Shuangtaizi Estuary, Bohai Sea of China in May, 2013. Ecological risk assessment indicated that most heavy metals cause low ecological risk to the estuarine environment, with the exception of Cd and Hg (considerable and moderate risk, respectively). Principal component analysis in combination with correlation analysis among heavy metals, PHCs and geological factors (e.g., granularity) was used to identify possible sources of pollutants in Shuangtaizi Estuary. Results showed that the main pollution sources of the area come from anthropogenic factors, such as sewage discharge and oil exploitation.

  14. Using Video to Communicate Scientific Findings -- Parking lot sealcoat as a source of polycyclic aromatic hydrocarbon contamination

    NASA Astrophysics Data System (ADS)

    Harned, D. A.; Moorman, M.; Van Metre, P. C.; Mahler, B. J.

    2012-12-01

    The U.S Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) provides information about (1) water-quality conditions and how those conditions vary locally, regionally, and nationally, (2) water-quality trends, and (3) factors that affect those trends and conditions. Video is one tool being used to communicate the relevance of scientific findings of the NAWQA program to general audiences, such as resource managers, educational groups, public officials, and the general public. One hundred twenty scientists and educators attending the 2010 and 2011 Fall meetings of the American Geophysical Union and the 2012 meeting of the National Monitoring Council viewed USGS videos and answered surveys using Likert response-scaling to identify the important elements of science videos. The most important elements identified from the surveys were style, including strong visuals and an engaging story with a simple message, as well as elements of substance including a take-home message, clarity, and believability. Deemed least important were journalistic elements showing different points of view and obstacles overcome. Viewers also identified the inclusion of the hypothesis statement and study methods as unimportant to include in a science video. As part of the NAWQA assessment of water-quality conditions and the factors that affect those conditions, parking-lot sealcoat is being studied as a source of polycyclic aromatic hydrocarbon (PAH) contamination. A film documenting a study to quantify the transport of PAHs from a parking-lot area coated with coal-tar sealcoat aims to make the study understandable to a lay audience. The film, titled "Paint it Black," documents the experimental site preparation, sealcoat application, and air and water sampling, with commentary by the principal scientists. Methods for sampling are described and shown in the video, and results from previous coal-tar sealcoat studies are summarized. The film provides a website address with

  15. [Distribution Characteristics and Source Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Dust of Xi'an City, China].

    PubMed

    Wang, Li; Wang, Li-jun; Shi, Xing-min; Lu, Xin-wei

    2016-04-15

    A total of 58 surface dust samples were collected from Xi'an city. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography with a flame ionization detector (GC-FID). At the same time, the distribution and sources of PAHs in surface dust were studied. The results showed that the concentrations of individual PAH ranged from 14.69 to 6370. 48 microg x kg(-1), and the total concentrations of 16 PAHs (∑16 PAHs) ranged from 5039.67 to 47,738.50 microg x kg(-1), with a mean of 13,845.82 microg x kg(-1). Compared to the Y PAHs levels of other cities, the ∑16 PAHs in surface dust of Xi'an belonged to a relatively higher level. PAHs in surface dust were mainly dominated by high molecular weight PAHs with 4-6 rings and the concentration of 7 carcinogenic PAHs (1 CPAHs) accounted for 46.08% of 3 16PAHs. The mean of ∑16 PAHs in surface dust had the highest concentration at industrial area; followed by the educational area, traffic area, business and traffic area; residential area and parks showed relatively lower concentration. The average content of ∑16 PAHs in surface dust presented an increasing trend along the main urban area--the second ring road--the third ring road. ∑16 PAHs in surface dust had higher concentrations at the industrial areas of the east and west suburbs of Xi'an, the south suburb and the north section of the second ring road; ∑16 PAHs concentrations in the main urban area, north suburb and southeast part of Xi'an were relatively lower. The results of ratio, cluster analysis and principal component analysis showed that PAHs in surface dust were mainly originated from the combustion of fossil fuels and coal combustion. Among them, diesel combustion reached 36.07%, gasoline combustion accounted for 32.31%, and coal combustion was resposbe for 23.40%

  16. Organic pollutants in the coastal environment off San Diego, California. 1: Source identification and assessment by compositional indices of polycyclic aromatic hydrocarbons

    SciTech Connect

    Zeng, E.Y.; Vista, C.L.

    1997-02-01

    Samples collected in January and June 1994 from the Point Loma Wastewater Treatment Plant (PLWTP) effluent, Tijuana River runoff, and microlayer, sediment trap, and surface sediment at several locations adjacent to the PLWTP outfall, mouth of the Tijuana River, and San Diego Bay were analyzed in an attempt to identify and assess the sources of hydrocarbon inputs into the coastal marine environment off San Diego. Several compositional indices of polycyclic aromatic hydrocarbons (PAHs), for example, alkyl homologue distributions, parent compound distributions, and other individual PAH ratios, were used to identify the sources of PAHs. Partially due to the decline of PAH emission from the PLWTP outfall, PAHs found in the sea surface microlayer, sediments, and water column particulates near the PLWTP outfall were predominantly derived from nonpoint sources. The sea microlayer near the mouth of the Tijuana River appeared to accumulate enhanced amounts of PAHs and total organic carbon and total nitrogen, probably discharged from the river, although they were in extremely low abundance in the sediments at the same location. Surprisingly, PAHs detected in the microlayer and sediments in San Diego Bay were mainly derived from combustion sources rather than oil spills, despite the heavy shipping activities in the area.

  17. RECOMMENDED OPERATING PROCEDURE NO. 2.3: SAMPLING AND ANALYSIS OF TOTAL HYDROCARBONS FROM SOURCES BY CONTINUOUS EMISSION MONITOR

    EPA Science Inventory

    The report is a recommended operating procedure (ROP) prepared for use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). he described method is applicable to the continuous measurement of total hydrocarbons (THCs), also known as tot...

  18. ROLE OF SOURCE MATRIX IN THE BIOAVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS TO DEPOSIT-FEEDING BENTHIC INVERTEBRATES

    EPA Science Inventory

    The bioavailability of polycyclic aromatic hydrocarbons (PAHs) to benthic organisms is complicated by the variety of ways that they are introduced to coastal waters (dissolved, as nonaqueous phase liquids, and tightly bound to soot, coal, tire rubber, and eroded shale). In order ...

  19. Plant hydrocarbon recovery process

    SciTech Connect

    Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

    1982-01-26

    A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

  20. Non-methane hydrocarbons in the atmosphere of a Metropolitan City and a background site in South Korea: Sources and health risk potentials

    NASA Astrophysics Data System (ADS)

    Choi, Eunhwa; Choi, Kyungho; Yi, Seung-Muk

    2011-12-01

    Hourly concentrations of non-methane hydrocarbons (NMHCs) were collected at a background monitoring site between April of 2004 and March of 2005 and at suburban and urban sites between March and December of 2006. The sources of NMHCs were identified and associated health risks through the inhalation pathway were evaluated. Positive matrix factorization (PMF) results showed that solvent sources account for the largest portion of the total NMHCs at suburban and urban areas in South Korea, and the risk assessment combined with the PMF results indicated that risk-weighted contributions of solvent sources were enhanced compared to the absolute contribution (from 52% to 68% in suburban areas and from 47% to 80% in urban areas). Carcinogenic risk due to benzene exposure exceeded the one-in-a-million (i.e., 10 -6) cancer benchmark at all three study sites, and the fractions of the population with greater than the benchmark level were 87%, 99%, and 98% in the background, suburban, and urban sites, respectively. Common benzene sources of three study sites were predicted to be Shandong in China based on the 120 h potential source contribution function (PSCF) analysis. To prioritize management options for NMHC sources, risk term may give more meaningful information than amount term. This study suggests that controlling solvent sources would be better option for the mitigation of non-carcinogenic health risk from airborne NMHCs. In addition, the identification of benzene sources using PSCF can be used to assist policymakers in developing regional measures to reduce benzene.

  1. Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/absolute principal component scores (PCA/APCS) receptor model.

    PubMed

    Guo, H; Wang, T; Louie, P K K

    2004-06-01

    Receptor-oriented source apportionment models are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS model was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor model indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS model was applicable for estimation

  2. Identifying the source of petroleum pollution in sediment cores of southwest of the Caspian Sea using chemical fingerprinting of aliphatic and alicyclic hydrocarbons.

    PubMed

    Shirneshan, Golshan; Bakhtiari, Alireza Riyahi; Memariani, Mahmoud

    2017-02-15

    In this study, the concentration and sources of aliphatic and petroleum markers were investigated in 105 samples of Anzali, Rezvanshahr and Astara cores from the southwest of Caspian Sea. Petroleum importation was diagnosed as a main source in most depths of cores by the results of unresolved complex mixture, carbon preference index and hopanes and steranes. From the chemical diagnostic parameters, petroleum inputs in sediment of cores were determined to be different during years and the sources of hydrocarbons in some sections differed than Anzali and Turkmenistan and Azerbaijan oils. Diagenic ratios in most sediments of upper and middle sections in Astara core were determined to be highly similar to those of Azerbaijan oil, while the presence of Turkmenistan and Anzali oils were detected in a few sections of Anzali and Rezvanshahr cores and only five layers of downer section in Anzali core, respectively.

  3. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Rizhao coastal area (China) using diagnostic ratios and factor analysis with nonnegative constraints.

    PubMed

    Chen, Hai-yang; Teng, Yan-guo; Wang, Jin-sheng

    2012-01-01

    In this study, sources of polycyclic aromatic hydrocarbons (PAHs) found in surface sediments of the Rizhao coastal area (China) were apportioned using diagnostic ratios and factor analysis with nonnegative constraints (FA-NNC). Bivariate plots of selected diagnostic ratios showed that the sources of PAHs identified in surface sediments seemed to be mixed sources dominated by petroleum-related. Literature PAH source profiles were modified based on the first-order degradation reaction in the atmosphere and sediments, and were considered as comparison for source identification. Five significant factors were determined with the diagnostic tools including coefficient of determination, cumulative percent variance and Exner function. By visually comparing PAH patterns and from the sum of squares of differences between modeled and modified literature PAH profiles, the potential sources were apportioned with the FA-NNC. The main contribution sources of PAHs originated from diesel engine (27.22%), followed by traffic emission (25.03%), gasoline engine (18.95%), coal power plant (14.77%) and coal residential (14.03%). Energy consumption was the predominant reason for PAH pollution in that region.

  4. Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

    NASA Astrophysics Data System (ADS)

    Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

    2012-11-01

    The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.

  5. Establishing Total Maximum Daily Load (TMDL) Wasteload Allocations (WLAs) for Storm Water Sources and NPDES Permit Requirements Based on Those WLAs

    EPA Pesticide Factsheets

    The memoranda clarify existing EPA regulatory requirements for, and provide guidance on, establishing wasteload allocations (WLAs) for storm water discharges in total maximum daily loads (TMDLs) approved or established by EPA.

  6. Dynamic Channel Allocation

    DTIC Science & Technology

    2003-09-01

    7 1 . Fixed Channel Allocation (FCA) ........................................................7 2. Dynamic Channel ...19 7. CSMA/CD-Based Multiple Network Lines .....................................20 8. Hybrid Channel Allocation in Wireless Networks...28 1 . Channel Allocation

  7. A quantitative assessment of source contributions to fine particulate matter (PM2.5)-bound polycyclic aromatic hydrocarbons (PAHs) and their nitrated and hydroxylated derivatives in Hong Kong.

    PubMed

    Ma, Yiqiu; Cheng, Yubo; Qiu, Xinghua; Lin, Yan; Cao, Jing; Hu, Di

    2016-12-01

    Atmospheric polycyclic aromatic hydrocarbons (PAHs) and their derivatives are of great concern due to their adverse health effects. However, source identification and apportionment of these compounds, particularly their nitrated and hydroxylated derivatives (i.e., NPAHs and OHPAHs), in fine particulate matter (PM2.5) in Hong Kong are still lacking. In this study, we conducted a 1-year observation at an urban site in Hong Kong. PM2.5-bound PAHs and their derivatives were measured, with median concentrations of 4590, 44.4 and 31.6 pg m(-3) for ∑21PAHs, ∑13NPAHs, and ∑12OHPAHs, respectively. Higher levels were observed on regional pollution days than on long regional transport (LRT) or local emission days. Based on positive matrix factorization analysis, four sources were determined: marine vessels, vehicle emissions, biomass burning, and a mixed source of coal combustion and NPAHs secondary formation. Coal combustion and biomass burning were the major sources of PAHs, contributing over 85% of PAHs on regional and LRT days. Biomass burning was the predominant source of OHPAHs throughout the year, while NPAHs mainly originated from secondary formation and fuel combustion. For benzo[a]pyrene (BaP)-based PM2.5 toxicity, the mixed source of coal combustion and NPAHs secondary formation was the major contributor, followed by biomass burning and vehicle emissions.

  8. Assessment of polycyclic aromatic hydrocarbons in Lates niloticus, Oreochromis niloticus and Rastrineobola argentea as sources of human exposure in Kisumu Bay, Winam Gulf of Lake Victoria.

    PubMed

    Onyango, Alice A; Lalah, Joseph O; Wandiga, Shem O; Gichuki, John

    2012-05-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) in Lates niloticus, Oreochromis niloticus and Rastrineobola argentea from three beaches were assessed to establish whether they are sources of human exposure in Kisumu Bay, Winam Gulf, Lake Victoria, Kenya. O. niloticus had 12 PAHs detected (TPAH 3.93 μg/kg); L. niloticus had 11 (TPAH 3.17 μg/kg). In both cases, the highest and lowest concentrations were Pyrene and Indeno(1,2,3-cd)pyrene, respectively, and the TPAHs were greater than the 2 μg/kg limit allowed by the European Commission although individually they were lower. R. argentea had 2 PAHs (TPAH 0.035 μg/kg). PAH pollution in the Winam Gulf, a potential source of exposure to human through contaminated fish, should be mitigated and safe management practices that reduce PAH levels should be adopted.

  9. Occurrence and source of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) in tidal flats of the Ariake Bay, Japan.

    PubMed

    Sankoda, Kenshi; Kuribayashi, Tomonori; Nomiyama, Kei; Shinohara, Ryota

    2013-07-02

    In this study, we hypothesize that natural photochemical reactions of polycyclic aromatic hydrocarbons (PAHs) in tidal flats are responsible for the occurrence of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs). This study aims to survey the impact of photochemical reactions using a combination of field surveys and lab-scale experiments. Concentrations and profiles of PAHs and Cl-PAHs in road dust and sediments collected from seven tunnels and two watersheds, respectively, were determined. In the lab-scale experiments, anthracene was irradiated with ultraviolet (UV) light under various salinity conditions. No detectable Cl-PAHs were found in the road dust. However, Cl-PAHs were detected in the sediments from 700 to 6.1 × 10(3) pg g(-1) and specifically from downstream sites. 2-Monochloroanthracene (2-Cl-ANT) and 9,10-dichloroanthracene (9,10-di-Cl-ANT) were dominant in the sediments. In the Domen River watershed, the ∑Cl-PAHs and the salinity showed a significant positive correlation (p < 0.01) in the sediments, while such a correlation was not found for PAHs. 2-Cl-ANT, 9-monochloroanthracene, and 9,10-di-Cl-ANT were identified as transformation products in the UV irradiation experiments. Production of these Cl-PAHs was dependent on the solution salinity. These results support our hypothesis, and we conclude that photochemical reactions significantly contribute to the occurrence of Cl-PAHs in the studied tidal flats.

  10. Polycyclic aromatic hydrocarbons in soils from urban to rural areas in Nanjing: Concentration, source, spatial distribution, and potential human health risk.

    PubMed

    Wang, Chunhui; Wu, Shaohua; Zhou, Sheng Lu; Wang, Hui; Li, Baojie; Chen, Hao; Yu, Yanna; Shi, Yaxing

    2015-09-15

    Polycyclic aromatic hydrocarbons (PAHs) have become a major type of pollutant in urban areas and their degree of pollution and characteristics of spatial distribution differ between various regions. We conducted a comprehensive study about the concentration, source, spatial distribution, and health risk of 16 PAHs from urban to rural soils in Nanjing. The mean total concentrations of 16 PAHs (∑16PAHs) were 3330 ng g(-1) for urban soils, 1680 ng g(-1) for suburban soils, and 1060 ng g(-1) for rural soils. Five sources in urban, suburban, and rural areas of Nanjing were identified by positive matrix factorization. Their relative contributions of sources to the total soil PAH burden in descending order was coal combustion, vehicle emissions, biomass burning, coke tar, and oil in urban areas; in suburban areas the main sources of soil PAHs were gasoline engine and diesel engine, whereas in rural areas the main sources were creosote and biomass burning. The spatial distribution of soil PAH concentrations shows that old urban districts and commercial centers were the most contaminated of all areas in Nanjing. The distribution pattern of heavier PAHs was in accordance with ∑16PAHs, whereas lighter PAHs show some special characteristics. Health risk assessment based on toxic equivalency factors of benzo[a]pyrene indicated a low concentration of PAHs in most areas in Nanjing, but some sensitive sites should draw considerable attention. We conclude that urbanization has accelerated the accumulation of soil PAHs and increased the environmental risk for urban residents.

  11. Tracer-based source apportionment of polycyclic aromatic hydrocarbons in PM2.5 in Guangzhou, southern China, using positive matrix factorization (PMF).

    PubMed

    Gao, Bo; Guo, Hai; Wang, Xin-Ming; Zhao, Xiu-Ying; Ling, Zhen-Hao; Zhang, Zhou; Liu, Teng-Yu

    2013-04-01

    From 28 November to 23 December 2009, 24-h PM2.5 samples were collected simultaneously at six sites in Guangzhou. Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) together with certain molecular tracers for vehicular emissions (i.e., hopanes and elemental carbon), coal combustion (i.e., picene), and biomass burning (i.e., levoglucosan) were determined. Positive matrix factorization (PMF) receptor model combined with tracer data was applied to explore the source contributions to PAHs. Three sources were identified by both inspecting the dominant tracer(s) in each factor and comparing source profiles derived from PMF with determined profiles in Guangzhou or in the Pearl River Delta region. The three sources identified were vehicular emissions (VE), biomass burning (BB), and coal combustion (CC), accounting for 11 ± 2%, 31 ± 4%, and 58 ± 4% of the total PAHs, respectively. CC replaced VE to become the most important source of PAHs in Guangzhou, reflecting the effective control of VE in recent years. The three sources had different contributions to PAHs with different ring sizes, with higher BB contributions (75 ± 3%) to four-ring PAHs such as pyrene and higher CC contributions (57 ± 4%) to six-ring PAHs such as benzo[ghi]perylene. Temporal variations of VE and CC contributions were probably caused by the change of weather conditions, while temporal variations of BB contributions were additionally influenced by the fluctuation of BB emissions. Source contributions also showed some spatial variations, probably due to the source emission variations near the sampling sites.

  12. Attributing risk burden of PM2.5-bound polycyclic aromatic hydrocarbons to major emission sources: Case study in Guangzhou, south China

    NASA Astrophysics Data System (ADS)

    Yu, Qingqing; Gao, Bo; Li, Guanghui; Zhang, Yanli; He, Quanfu; Deng, Wei; Huang, Zhonghui; Ding, Xiang; Hu, Qihou; Huang, Zuzhao; Wang, Yujun; Bi, Xinhui; Wang, Xinming

    2016-10-01

    Polycyclic aromatic hydrocarbons (PAHs) have attracted an increasing concern in China's megacities. However, rare information is available on the spatial and seasonal variations of inhalation cancer risk (ICR) due to PAH exposure and their relations to specific sources. In this study, year-round PM2.5 samples were collected from 2013 to 2014 by high-volume samplers at four sites (one urban, two rural and one roadside station) in Guangzhou in the highly industrialized and densely populated Pearl River Delta (PRD) region and analyzed for 26 polycyclic aromatic hydrocarbons (PAHs) together with molecular tracers including levoglucosan, hopanes and elemental carbon. Higher molecular weight PAHs (5-ring or above) accounted for 64.3-87.5% of total PAHs. Estimated annual averages of benzo(a)pyrene-equivalent carcinogenic potency (BaPeq) were 1.37, 2.31 and 1.56 ng/m3 at urban SZ, rural JL and rural WQS, respectively, much higher than that at the roadside station YJ in an urban street canyon. ICR of PAHs in wintertime reached 2.2 × 10-4, nearly 3 times that in summer; and cancer risk of PAHs was surprisingly higher at the rural site than at other sites. Source contributions by positive matrix factorization (PMF) in the aid of molecular tracers revealed that overall coal combustion and biomass burning altogether contributed 73.8% of total PAHs and 85.2% of BaPeq, and particularly in winter biomass burning became the most significant source of total PAHs and BaPeq (51.8% and 52.5%), followed by coal combustion (32.0% and 39.1%) and vehicle emission (16.2% and 8.4%). The findings of this work suggest that even in China's megacities like Guangzhou, limiting biomass burning may benefit PAHs pollution control and cancer risk reduction.

  13. Polycyclic aromatic hydrocarbons (PAHs) in wild marine organisms from South China Sea: Occurrence, sources, and human health implications.

    PubMed

    Ke, Chang-Liang; Gu, Yang-Guang; Liu, Qi; Li, Liu-Dong; Huang, Hong-Hui; Cai, Nan; Sun, Zhi-Wei

    2017-04-15

    Concentrations of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured in 15 marine wild organism species from South China Sea. The concentration (dry weight) of 16 PAHs ranged from 94.88 to 557.87ng/g, with a mean of 289.86ng/g. The concentrations of BaP in marine species were no detectable. The composition of PAHs was characterized by the 2- and 3-ring PAHs in marine species, and NA, PHE and FA were the dominant constituents. PAHs isomeric ratios indicated PAHs mainly originated from grass, wood and coal combustion, and petroleum. The human health risk assessment based on the excess cancer risk (ECR) suggested the probability of PAHs posing carcinogenic risk to human beings with consumption of marine organisms were negligible (probability<1×10(-6)).

  14. Estimation of sources and inflow of dioxins and polycyclic aromatic hydrocarbons from the sediment core of Lake Suwa, Japan.

    PubMed

    Ikenaka, Yoshinori; Eun, Heesoo; Watanabe, Eiki; Kumon, Fujio; Miyabara, Yuichi

    2005-12-01

    To elucidate the historical changes in polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), coplanar polychlorinated biphenyl (co-PCB), and polycyclic aromatic hydrocarbon (PAH) inflows in Lake Suwa, their concentrations in the sediment core were analyzed in 5 cm interval. The maximum concentrations (depth cm) of PCDDs/DFs, co-PCBs, and PAHs were 25.2 ng/g dry (30-35 cm), 19.0 ng/g dry (30-35 cm), and 738, 795 ng/g dry (50-55 cm, 30-35 cm), respectively. Age and sedimentation rate of the sediment were estimated from the vertical changes in apparent density. Deposition rate of dioxins and PAHs were calculated from the concentration and sedimentation rate of the sediment. The results indicate that large amounts of dioxins and PAHs flowed into the lake in flood stage compared to normal stage.

  15. Role of source matrix in the bioavailability of polycyclic aromatic hydrocarbons to deposit-feeding benthic invertebrates.

    PubMed

    Rust, Aaron J; Burgess, Robert M; McElroy, Anne E; Cantwell, Mark G; Brownawell, Bruce J

    2004-11-01

    The bioavailability of polycyclic aromatic hydrocarbons (PAHs) to benthic organisms is complicated by the variety of ways that they are introduced to coastal waters (dissolved, as nonaqueous phase liquids, and tightly bound to soot, coal, tire rubber, and eroded shale). In order to better understand the controlling variables that affect chemical and biological availability of PAHs, a study was conducted in which three deposit-feeding infaunal benthic invertebrate species (Cirriformia grandis, Clymenella torquata, and Macoma balthica) were exposed to sediments amended with PAH-rich materials (coal dust, tire rubber, diesel soot, creosote, crude oil, and fuel oil). Lipid and organic carbon normalized bioaccumulation factors (BAF(1oc)s) were calculated after 20 d of exposure and PAH bioavailability from the different treatments was assessed. Bioaccumulation of coal-derived PAHs usually was too low to be measured, though PAHs associated with soot and tire rubber showed significant accumulation in organism tissues. Polycyclic aromatic hydrocarbons from the fuel oil, creosote, and crude oil treatments were more bioavailable than PAHs bound in solid carbonaceous matrices (soot, coal, and tire rubber). Desorption of PAHs from the amended sediments into seawater also was measured using XAD resin. As was observed with bioaccumulation, PAHs in coal were desorbed the least; tire rubber and diesel soot were intermediate; and creosote, fuel oil, and crude oil desorbed to the greatest extent. In only one out of the three species evaluated was PAH bioaccumulation related to extent of desorption after 20 d. Decoupling between biological and chemical availability may be due to species-specific factors such as surfactant-mediated solubilization in the guts of some deposit-feeding organisms. A significant finding of this work was the demonstration that PAHs associated with soot and tire rubber in their native state (rather than experimentally added) are available to some benthic biota.

  16. Bioavailability of Polycyclic Aromatic Hydrocarbons and their Potential Application in Eco-risk Assessment and Source Apportionment in Urban River Sediment

    NASA Astrophysics Data System (ADS)

    Yang, Xunan; Yu, Liuqian; Chen, Zefang; Xu, Meiying

    2016-03-01

    Traditional risk assessment and source apportionment of sediments based on bulk polycyclic aromatic hydrocarbons (PAHs) can introduce biases due to unknown aging effects in various sediments. We used a mild solvent (hydroxypropyl-β-cyclodextrin) to extract the bioavailable fraction of PAHs (a-PAHs) from sediment samples collected in Pearl River, southern China. We investigated the potential application of this technique for ecological risk assessments and source apportionment. We found that the distribution of PAHs was associated with human activities and that the a-PAHs accounted for a wide range (4.7%–21.2%) of total-PAHs (t-PAHs), and high risk sites were associated with lower t-PAHs but higher a-PAHs. The correlation between a-PAHs and the sediment toxicity assessed using tubificid worms (r = ‑0.654, P = 0.021) was greater than that from t-PAH-based risk assessment (r = ‑0.230, P = 0.472). Moreover, the insignificant correlation between a-PAH content and mPEC-Q of low molecular weight PAHs implied the potiential bias of t-PAH-based risk assessment. The source apportionment from mild extracted fractions was consistent across different indicators and was in accordance with typical pollution sources. Our results suggested that mild extraction-based approaches reduce the potential error from aging effects because the mild extracted PAHs provide a more direct indicator of bioavailability and fresher fractions in sediments.

  17. Exploring hydrocarbon-bearing shale formations with multi-component seismic technology and evaluating direct shear modes produced by vertical-force sources

    NASA Astrophysics Data System (ADS)

    Alkan, Engin

    It is essential to understand natural fracture systems embedded in shale-gas reservoirs and the stress fields that influence how induced fractures form in targeted shale units. Multicomponent seismic technology and elastic seismic stratigraphy allow geologic formations to be better images through analysis of different S-wave modes as well as the P-wave mode. Significant amounts of energy produced by P-wave sources radiate through the Earth as downgoing SV-wave energy. A vertical-force source is an effective source for direct SV radiation and provides a pure shear-wave mode (SV-SV) that should reveal crucial information about geologic surfaces located in anisotropic media. SV-SV shear wave modes should carry important information about petrophysical characteristics of hydrocarbon systems that cannot be obtained using other elastic-wave modes. Regardless of the difficulties of extracting good-quality SV-SV signal, direct shear waves as well as direct P and converted S energy should be accounted for in 3C seismic studies. Acquisition of full-azimuth seismic data and sampling data at small intervals over long offsets are required for detailed anisotropy analysis. If 3C3D data can be acquired with improved signal-to-noise ratio, more uniform illumination of targets, increased lateral resolution, more accurate amplitude attributes, and better multiple attenuation, such data will have strong interest by the industry. The objectives of this research are: (1) determine the feasibility of extracting direct SV-SV common-mid-point sections from 3-C seismic surveys, (2) improve the exploration for stratigraphic traps by developing systematic relationship between petrophysical properties and combinations of P and S wave modes, (3) create compelling examples illustrating how hydrocarbon-bearing reservoirs in low-permeable rocks (particularly anisotropic shale formations) can be better characterized using different Swave modes (P-SV, SV-SV) in addition to the conventional P

  18. Concentrations and sources of non-methane hydrocarbons (NMHCs) from 2005 to 2013 in Hong Kong: A multi-year real-time data analysis

    NASA Astrophysics Data System (ADS)

    Ou, Jiamin; Guo, Hai; Zheng, Junyu; Cheung, Kalam; Louie, Peter K. K.; Ling, Zhenhao; Wang, Dawei

    2015-02-01

    To understand the long-term variations of nonmethane hydrocarbons (NMHCs) and their emission sources, real-time speciated NMHCs have been monitored in Hong Kong since 2005. Data analysis showed that the concentrations of C3-C5 and C6-C7 alkanes slightly increased from 2005 to 2013 at a rate of 0.0015 and 0.0005 μg m-3 yr-1 (p < 0.05), respectively, while aromatics decreased at a rate of 0.006 μg m-3 yr-1 (p < 0.05). Positive Matrix Factorization (PMF) model was applied to identify and quantify the NMHC sources. Vehicular exhaust, gasoline evaporation and liquefied petroleum gas (LPG) usage, consumer product and printing, architectural paints, and biogenic emissions were identified and on average accounted for 20.2 ± 6.2%, 25.4 ± 6.3%, 32.6 ± 5.8%, 21.5 ± 4.5%, and 3.3 ± 1.5% of the ambient NMHC concentrations, respectively. From 2005 to 2013, the contributions of both traffic-related sources and solvent-related sources showed no significant changes, different from the trends in emission inventory. On O3 episode days dominated by local air masses, the increase ratio of NMHC species from non-episode to episode days was found to be a natural function of the reactivity of NMHC species, suggesting that photochemical reaction would significantly change the NMHCs composition between emission sources and the receptors. Effect of photochemical reaction loss on receptor-oriented source apportionment analysis needs to be quantified in order to identify the NMHCs emission sources on O3 episode days.

  19. Levels, composition profiles and sources of polycyclic aromatic hydrocarbons in surface sediments from Nan'ao Island, a representative mariculture base in South China.

    PubMed

    Gu, Yang-Guang; Lin, Qin; Lu, Teng-Teng; Ke, Chang-Liang; Sun, Run-Xia; Du, Fei-Yan

    2013-10-15

    Levels, composition profiles and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Nan'ao Island, one of the largest mariculture bases in South China were investigated. The total PAHs concentrations ranged from 265.49 to 951.27 ng/g (dry weight) with a mean of 515.90 ng/g, and seven possible carcinogenic PAHs accounted for 76.94% of total PAHs. Among various mariculture sections, the highest PAHs level was found in the large seaweed culture; while the lowest concentration was detected in the abandoned culture. The composition of PAHs was characterized by low molecular weight PAHs, and Phe Ant and Pyr were the dominant constituent. PAHs may be mainly originated from petroleum and combustion of biomass and coal. Risk assessments suggested that the probability of adverse effect was lower than 25% and PAHs exposure was moderately carcinogenic.

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

    PubMed

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

    2016-05-01

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

  1. Characterization of coal-derived hydrocarbons and source-rock potential of coal beds, San Juan Basin, New Mexico and Colorado, U.S.A.

    USGS Publications Warehouse

    Rice, D.D.; Clayton, J.L.; Pawlewicz, M.J.

    1989-01-01

    .5 ppt), are chemically wetter (C1/C1-5 values range from 0.85 to 0.95), and contain less CO2 (< 2%). These gases are interpreted to have been derived from type III kerogen dispersed in marine shales of the underlying Lewis Shale and nonmarine shales of the Fruitland Formation. In the underlying Upper Cretaceous Dakota Sandstone and Tocito Sandstone Lentil of the Mancos Shale, another gas type is produced. This gas is associated with oil at intermediate stages of thermal maturity and is isotopically lighter and chemically wetter at the intermediate stage of thermal maturity as compared with gases derived from dispersed type III kerogen and coal; this gas type is interpreted to have been generated from type II kerogen. Organic matter contained in coal beds and carbonaceous shales of the Fruitland Formation has hydrogen indexes from Rock-Eval pyrolysis between 100 and 350, and atomic H:C ratios between 0.8 and 1.2. Oxygen indexes and atomic O:C values are less than 24 and 0.3, respectively. Extractable hydrocarbon yields are as high as 7,000 ppm. These values indicate that the coal beds and carbonaceous shales have good potential for the generation of liquid hydrocarbons. Voids in the coal filled with a fluorescent material that is probably bitumen is evidence that liquid hydrocarbon generation has taken place. Preliminary oil-source rock correlations based on gas chromatography and stable carbon isotope ratios of C15+ hydrocarbons indicate that the coals and (or) carbonaceous shales in the Fruitland Formation may be the source of minor amounts of condensate produced from the coal beds at relatively low levelsof thermal maturity (Rm=0.7). ?? 1989.

  2. The nutrient, total petroleum hydrocarbon and heavy metal contents in the seawater of Bohai Bay, China: Temporal-spatial variations, sources, pollution statuses, and ecological risks.

    PubMed

    Peng, Shitao

    2015-06-15

    Seawater samples collected between 2007 and 2012 were determined the concentrations of nutrient (DIN and DIP), total petroleum hydrocarbon (TPH), and six different heavy metals (As, Cu, Zn, Pb, Cd and Hg). The DIN, DIP, TPH, Pb, and Cd concentrations decreased from 2007 to 2009 or 2010 and increased after 2010. However, the Hg and Cu concentrations increased from 2007 to 2012. In contrast, the As and Zn gradually decreased during the study period. All of the pollutant concentrations gradually decreased from the shoreline to the offshore sites. PCA result showed that urban and port areas, agriculture, and atmospheric deposition were the main sources of pollutants in the bay. Although most of the pollutants were present at concentrations bellow the highest seawater quality standards in China, eutrophication was a risk in Bohai Bay. In addition, DIN was the main pollutant and was responsible for the eutrophication risk in Bohai Bay.

  3. Kerogen maturation and incipient graphitization of hydrocarbon source rocks in the Arkoma Basin, Oklahoma and Arkansas: A combined petrographic and Raman spectrometric study

    USGS Publications Warehouse

    Spotl, C.; Houseknecht, D.W.; Jaques, R.C.

    1998-01-01

    Dispersed kerogen of the Woodford-Chattanooga and Atoka Formations from the subsurface of the Arkoma Basin show a wide range of thermal maturities (0.38 to 6.1% R(o)) indicating thermal conditions ranging from diagenesis to incipient rock metamorphism. Raman spectral analysis reveals systematic changes of both the first- and second-order spectrum with increasing thermal maturity. These changes include a pronounced increase in the D/O peak height ratio accompanied by a narrowing of the D peak, a gradual decrease in the D/O peak width ratio, and a shift of both peaks toward higher wave numbers. Second-order Raman peaks, though less intensive, also show systematic peak shifting as a function of R(o). These empirical results underscore the high potential of Raman spectrometry as a fast and reliable geothermometer of mature to supermature hydrocarbon source rocks, and as an indicator of thermal maturity levels within the anchizone.Dispersed kerogen of the Woodford-Chattanooga and Atoka Formations from the subsurface of the Arkoma Basin show a wide range of thermal maturities (0.38 to 6.1% Ro) indicating thermal conditions ranging from diagenesis to incipient rock metamorphism. Raman spectral analysis reveals systematic changes of both the first- and second-order spectrum with increasing thermal maturity. These changes include a pronounced increase in the D/O peak height ratio accompanied by a narrowing of the D peak, a gradual decrease in the D/O peak width ratio, and a shift of both peaks toward higher wave numbers. Second-order Raman peaks, though less intensive, also show systematic peak shifting as a function of Ro. These empirical results underscore the high potential of Raman spectrometry as a fast and reliable geothermometer of mature to supermature hydrocarbon source rocks, and as an indicator of thermal maturity levels within the anchizone.

  4. Geochemical monitoring of the bottom sediments of the Barents Sea - exogenous and endogenous sources of polyaromatic hydrocarbons.

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Detailed organic geochemical study of the immersed bottom sediments of the Northern and North-Western parts of the Barents Sea region indicated the significant difference in the group and molecular composition of the dispersed organic matter (DOM). Hydrocarbons (HCs) distribution anomalies were identified in the western part of the Svalbard Island shelf, the area around the Shtokman gas condensate field and the Kola-Kanin Monocline shelf zone. The studied sediments (9 cores, up to 2 m length) were collected during scientific research cruises of "VNIIOkeangeology named after I.S. Gramberg" (Saint-Petersburg, Russia) to the Barents Sea between 1992-2006. Analytical procedure included the determination of elementary (TOC, Ccarb), group and molecular composition of DOM soluble part using preparative liquid chromatography and GC-MS analysis with the Agilent Technologies 6850/5973 GC System. The studied samples are generally represented by low carbonate homogeneous pelites and aleuropelites (Ccarb≤0.8% in sed.). The total organic carbon slightly varies through the sediment section and regularly decreases with depth, not exceeding 2% in the upper layer of sediments for the region. The maximum of chloroform bitumoid "a" was detected in the Svalbard shelf area (up to 0.04% in sed.). The molecular composition and ratio of PAHs in the Svalbard samples points to the high level of OM transformation (MPI1≥0.6), that along with the lack of biogenic structures (perylene, cadalene, rethene) and increased concentrations of naphthidogenic PAHs (phenanthrene, alkyl-phenanthrenes), indicates the genetic association with the shore coal deposits. The Shtockman and Kola-Kanin Monocline sediments revealed other general trends in PAHs distribution. They are distinguished by a lower maturity level (MPI1<0.5), halving of naphthidogenic components and the great increase of biogenic structures (mainly perylene) relatively the Svalbard shelf zone. In the case of the Shtokman gas

  5. Source apportionment vs. emission inventories of non-methane hydrocarbons (NMHC) in an urban area of the Middle East: local and global perspectives

    NASA Astrophysics Data System (ADS)

    Salameh, Thérèse; Sauvage, Stéphane; Afif, Charbel; Borbon, Agnès; Locoge, Nadine

    2016-03-01

    We applied the positive matrix factorization model to two large data sets collected during two intensive measurement campaigns (summer 2011 and winter 2012) at a sub-urban site in Beirut, Lebanon, in order to identify NMHC (non-methane hydrocarbons) sources and quantify their contribution to ambient levels. Six factors were identified in winter and five factors in summer. PMF-resolved source profiles were consistent with source profiles established by near-field measurements. The major sources were traffic-related emissions (combustion and gasoline evaporation) in winter and in summer accounting for 51 and 74 wt %, respectively, in agreement with the national emission inventory. The gasoline evaporation related to traffic source had a significant contribution regardless of the season (22 wt % in winter and 30 wt % in summer). The NMHC emissions from road transport are estimated from observations and PMF results, and compared to local and global emission inventories. The PMF analysis finds reasonable differences on emission rates, of 20-39 % higher than the national road transport inventory. However, global inventories (ACCMIP, EDGAR, MACCity) underestimate the emissions up to a factor of 10 for the transportation sector. When combining emission inventory to our results, there is strong evidence that control measures in Lebanon should be targeted on mitigating the NMHC emissions from the traffic-related sources. From a global perspective, an assessment of VOC (volatile organic compounds) anthropogenic emission inventories for the Middle East region as a whole seems necessary as these emissions could be much higher than expected at least from the road transport sector.

  6. Long-range atmospheric transport of polycyclic aromatic hydrocarbons: a global 3-D model analysis including evaluation of Arctic sources.

    PubMed

    Friedman, Carey L; Selin, Noelle E

    2012-09-04

    We use the global 3-D chemical transport model GEOS-Chem to simulate long-range atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). To evaluate the model's ability to simulate PAHs with different volatilities, we conduct analyses for phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP). GEOS-Chem captures observed seasonal trends with no statistically significant difference between simulated and measured mean annual concentrations. GEOS-Chem also captures variability in observed concentrations at nonurban sites (r = 0.64, 0.72, and 0.74, for PHE, PYR, and BaP). Sensitivity simulations suggest snow/ice scavenging is important for gas-phase PAHs, and on-particle oxidation and temperature-dependency of gas-particle partitioning have greater effects on transport than irreversible partitioning or increased particle concentrations. GEOS-Chem estimates mean atmospheric lifetimes of <1 day for all three PAHs. Though corresponding half-lives are lower than the 2-day screening criterion for international policy action, we simulate concentrations at the high-Arctic station of Spitsbergen within four times observed concentrations with strong correlation (r = 0.70, 0.68, and 0.70 for PHE, PYR, and BaP). European and Russian emissions combined account for ~80% of episodic high-concentration events at Spitsbergen.

  7. Polycyclic aromatic hydrocarbons (PAHs) in water and sediment from a river basin: sediment-water partitioning, source identification and environmental health risk assessment.

    PubMed

    Sun, Caiyun; Zhang, Jiquan; Ma, Qiyun; Chen, Yanan; Ju, Hanyu

    2017-02-01

    The information on concentration levels, partitioning and sources of pollutants in aquatic environment is quite necessary for pollution treatment and quality criteria. In this work, sixteen priority polycyclic aromatic hydrocarbons (PAHs) recommended by U.S. Environmental Protection Agency in the water and sediment of Yinma River Basin were firstly investigated. Among 16 individual PAHs, naphthalene was the highest average concentration in water samples as well as in sediment samples, 67.2 ng/L and 825.06 ng/g, respectively, whereas benzo(g,h,i)perylene was undetected in water samples nor in sediment samples. For three PAH compositional patterns, concentrations of light (2-3 ring) PAHs were dominant in water and sediment, accounting for 71.69 and 86.98 % respectively. The PAH partitioning in the sediment-water system was studied, results showed that PAH partitioning was in an unsteady state and tended to accumulate in the sediment. The possible sources of PAHs in water and sediment were both identified as a mixed source of petroleum and combustion. The benzo(a)pyrene equivalents (EBaP) values for PAHs in the water and sediment in some sites were relatively higher, suggesting the existence of environmental health risk.

  8. Occurrences, composition profiles and source identifications of polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments.

    PubMed

    Su, Peng-Hao; Lv, Bao-Yi; Tomy, Gregg T; Xu, Jin-Xiang; Tian, Wen; Hou, Chun-Yan; Yin, Fang; Li, Yi-Fan; Feng, Dao-Lun

    2017-02-01

    The aim of this study was to investigate the levels of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments. The ballast sediment samples were collected from six merchant ships docked in 2015 in Jiangyin City, China. Ballast sediments represent a potential vector for the transport of POPs and invasive species between marine environments. An attempt was also made to determine the sources of these compounds in the ballast sediment. The results indicated ballast sediments generally contain greater amounts of BDE-209 and comparable amounts of PAHs, PBDEs (exclusive of BDE-209) and PCBs compared to those in marine surface sediments. Based on the sediment quality guidelines, PAHs and PCBs in ballast sediments were estimated to have median or high potential of posing ecological risks, respectively, to marine life if ballast sediments were disposed without specific treatment. POPs in ballast sediments were derived from multiple sources with atmospheric deposition being an important origin. Ship activities including diesel exhaust and illegal oil sewage discharge were considerable contributors of certain individual POPs to ballast sediments. Our study is important because it represents the first report on levels, health risk assessment and source apportionments of POPs in ballast sediments and is a first step in the implementation of specific ballast sediment management measures.

  9. Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in forest soils from urban to rural areas in the Pearl River Delta of Southern China.

    PubMed

    Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

    2014-03-04

    The upper layer of forest soils (0-20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban-suburban-rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area.

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

    PubMed

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

    2011-12-01

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

  11. Population inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk in Beijing region: Contributions of indoor and outdoor sources and exposures

    NASA Astrophysics Data System (ADS)

    Zhou, Bin; Zhao, Bin

    2012-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. Efforts in assessing population inhalation exposure to PAHs, and its contribution to lung cancer risk for Chinese residents, have been limited due to insufficient data on measured indoor concentrations. A mass-balance model to predict indoor PAH concentrations was developed, along with estimated exposures and attributable lung cancer risks for residents in the Beijing region in 2006, with a 2-stage Monte Carlo simulation framework. The exposures and risks were split into three parts, based on the sources and places of exposure, to estimate the contributions of indoor and outdoor PAH sources and exposures, in order to better understand the source and place pattern of PAH exposure. PAHs bring considerable lung cancer risk to the population of Beijing region. The population attributable fraction (PAF) of lung cancer for Beijing's overall population is 2.99% [95% confidence interval (CI): 1.71%-4.26%]. Median contribution of indoor exposure to outdoor-originated PAHs (OUT-in) is 78% (CI: 73%-81%) in the overall population, for 97% (CI: 94%-99%) of whom OUT-in is the largest contributor. Rural residents are facing considerable exposure to indoor-originated PAHs (IN-in), which dominates the total exposure in 12% (CI: 2%-24%) of the rural population. This model framework could be used in quantitative comparison of different interventions on exposure to PAHs as well as other airborne pollutants.

  12. The spatial distribution and potential sources of polycyclic aromatic hydrocarbons (PAHs) over the Asian marginal seas and the Indian and Atlantic Oceans

    NASA Astrophysics Data System (ADS)

    Xu, Yue; Zhang, Yan-Lin; Li, Jun; Gioia, Rosalinda; Zhang, Gan; Li, Xiang-Dong; Spiro, Baruch; Bhatia, Ravinder S.; Jones, Kevin C.

    2012-04-01

    Gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed in air samples taken on a voyage of the Scholar Ship from January 16th to March 14th, 2008. Samples were taken from the Asian marginal seas and the Indian and Atlantic Oceans, providing an opportunity to assess spatial trends and potential sources of atmospheric PAHs over those oceans. The results show that continental sources were still responsible for some high concentrations of PAHs measured over the oceans. The Σ15PAHs in the gaseous phase were elevated on the approach to China and India, while the highest Σ15PAHs in the particulate phase were found at Chennai Harbor and close to Guinea. The high proportion of fluorene in the gas phase over the East and South China Sea could be a marker of coal and coke related combustion emission from Mainland China. The elevated high-molecular-weight PAHs in particles close to Guinea might be related to biomass burning in Africa. These results are consistent with previous PAH emission inventories and highlight the potential impact of continental PAH sources in China, India and Africa on the adjacent marine atmosphere.

  13. Occurrence, distribution, environmental risk assessment and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of the Liaohe River Basin, China.

    PubMed

    Bai, Yangwei; Meng, Wei; Xu, Jian; Zhang, Yuan; Guo, Changsheng; Lv, Jiapei; Wan, Jun

    2014-12-01

    The occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments in Liaohe River Basin. The total PAH concentrations ranged from 111.9 to 2,931.6 ng/L in water and from 92.2 to 295,635.2 ng/g dry weight (dw) in sediments. The PAHs in water were dominated by 2-, 3- and 4-ring PAHs, which accounted for 42.8 %, 39.4 % and 14.2 % of the total PAHs, respectively, while in sediment PAHs were dominated by 3-, 4- and 5-ring PAHs, which accounted for 26.5 %, 44.2 % and 17.4 % of the total PAHs, respectively. The benzo[a]pyrene equivalents for water samples showed that in 37 out of 50 sites the values were greater than the national standard, and the environmental risk assessment indicated that high environmental risk of PAHs existed in sediments. Using the molecular ratio method for the source identification it was concluded that PAHs were determined to be from mixed sources (petroleum and combustion) in Liaohe River system and combustion sources in Daliao River system.

  14. Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

    PubMed Central

    Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

    2014-01-01

    The upper layer of forest soils (0–20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area. PMID:24599040

  15. Hydrocarbon source potential of the Tanezzuft Formation, Murzuq Basin, south-west Libya: An organic geochemical approach

    NASA Astrophysics Data System (ADS)

    El Diasty, W. Sh.; El Beialy, S. Y.; Anwari, T. A.; Batten, D. J.

    2017-06-01

    A detailed organic geochemical study of 20 core and cuttings samples collected from the Silurian Tanezzuft Formation, Murzuq Basin, in the south-western part of Libya has demonstrated the advantages of pyrolysis geochemical methods for evaluating the source-rock potential of this geological unit. Rock-Eval pyrolysis results indicate a wide variation in source richness and quality. The basal Hot Shale samples proved to contain abundant immature to early mature kerogen type II/III (oil-gas prone) that had been deposited in a marine environment under terrigenous influence, implying good to excellent source rocks. Strata above the Hot Shale yielded a mixture of terrigenous and marine type III/II kerogen (gas-oil prone) at the same maturity level as the Hot Shale, indicating the presence of only poor to fair source rocks.

  16. Polycyclic aromatic hydrocarbons (PAHs) in sediments from lake Lille Lungegårdsvannet in Bergen, western Norway; appraising pollution sources from the urban history.

    PubMed

    Andersson, Malin; Klug, Martin; Eggen, Ola Anfin; Ottesen, Rolf Tore

    2014-02-01

    This study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Bergen and determine the effect of specific point sources, as well as diffuse sources, and also help assess the risk of remediation plans. By using several organic compounds, metals and cyanide, we demonstrate the more accurate timing of sedimentation. The PAH results display very low concentrations in pre-industrial times, followed by a general increase that is punctuated by a few significant concentration increases. These most probably correspond to urban fires, domestic heating, gaswork activity and most recently due to traffic pollution. At the same depth as a significant rise in concentration from background levels occurred, the high relative occurrence of low-molecular-weight PAH-compounds, such as naphthalene, were replaced by heavier compounds, thus indicating a permanent change in source. The general observation, using ratios, is that the sources have shifted from pre-industrial pure wood and coal combustion towards mixed and petrogenic sources in more recent times. The (14)C dating provides evidence that the sedimentation rate stayed more-or-less constant for 4,500 years (from 7200 to 2700 calibrated years before present (calyr BP)), before isostatic uplift isolated the water body and the sedimentation rate decreased or sediments were eroded. The sediment input increased again when habitation and industrial activities encroached on the lake. The (14)C dating does not provide consistent data in that period, possibly due to the fact that the lake has been used as a waste site throughout the history of Bergen city. Therefore, results from (14)C dating from anthropogenically influenced sediments should be used with caution.

  17. The Dynamic of Annual Carbon Allocation to Wood in European Forests Is Consistent with a Combined Source-Sink Limitation of Growth: Implications on Growth Simulations in a Terrestrial Biosphere Model

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Leadley, P.; Delpierre, N.

    2014-12-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >103 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  18. Polycyclic aromatic hydrocarbons and black carbon in intertidal sediments of China coastal zones: Concentration, ecological risk, source and their relationship.

    PubMed

    Li, Xiaofei; Hou, Lijun; Li, Ye; Liu, Min; Lin, Xianbiao; Cheng, Lv

    2016-10-01

    Polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) have attracted many attentions, especially in the coastal environments. In this study, spatiotemporal distributions of PAHs and BC, and the correlations between BC and PAHs were investigated in the intertidal sediments of China coastal zones. BC in sediments was measured through dichromate oxidation (BCCr) and thermal oxidation (BCCTO). The concentrations of BCCr in the intertidal sediments ranged between 0.61 and 6.32mgg(-1), while BCCTO ranged between 0.57 and 4.76mgg(-1). Spatial variations of δ(13)C signatures in TOC and BC were observed, varying from -21.13‰ to -24.87‰ and from -23.53‰ to -16.78‰, respectively. PAH contents of sediments ranged from 195.9 to 4610.2ngg(-1) in winter and 98.2 to 2796.5ngg(-1) in summer, and significantly seasonal variations were observed at most sampling sites. However, the results of potential toxicity assessment indicated low ecological risk in the intertidal sediments of China coastal zones. Greater concentrations of PAHs measured in the sediments of estuarine environments indicated that rivers runoff may have been responsible for the higher PAH pollution levels in the intertidal sediments of China coastal zones. Pearson's correlation analysis suggested that pyrogenic compounds of PAH were significantly related to BC, due to that both BC and these compounds derived mainly from the combustion process of fossil fuels and biomass. Overall, increasing energy consumptions caused by anthropogenic activities can contribute more emissions of BC as well as PAHs and thus improve the importance of BC in indicating pyrogenic compounds of PAHs in the intertidal sediments of China coastal zones.

  19. Geochemical analysis of selected hydrocarbon samples in the Douala basin, Cameroon: Implications for an oil-prone source rock

    SciTech Connect

    Ackerman, W.C.; Boatwright, D.C. ); Burwood, R.; Mycke, B.; Van Lerberche, D. ); Bondjo, E.; Tamfu, S.; Ovono, D. )

    1993-09-01

    Several oil seeps from the onshore Douala basin in southwest Cameroon have been analyzed by GC/MS, PY/GC, and PY/GC/MS to determine the nature and quality of their source rocks. Geochemical data indicate oil-prone source rocks exist in the Upper Cretaceous to middle Tertiary passive margin sedimentary section. Paleoenvironmental indicators suggest these source rocks were deposited in paralic/deltaic to hypersaline marine settings. In conjunction with existing geological data, two geochemical models are proposed. (1) The oils were derived from a kerogen facies, which grades from a hypersaline marine environment in the Albian to a marine facies in the Cenomanian Maastrichtian. (2) The oils were derived from a hypersaline marine facies in the Albian and a second marine facies deposited during the Oligocene. Although previous work by other authors has shown the Upper Cretaceous/lower Tertiary source rocks from wells in the Logbaba gas field to be gas prone (type III), data from the present study provide evidence that at least one mature oil-prone source rock exists within this interval elsewhere in the basin.

  20. Structural factors affecting pore space transformation during hydrocarbon generation in source rock (shales): laboratory experiments and X-ray microtomography/SEM study

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, Dina; Korost, Dmitry; Gerke, Kirill

    2015-04-01

    Oil and gas generation is a complex superposition of processes which take place in the interiors and are not readily observable in nature in human life time-frames. During burial of the source rocks organic matter is transformed into a mixture of high-molecular compounds - precursors of oil and gas (kerogen). Specific thermobaric conditions trigger formation of low molecular weight hydrocarbon compounds. Generation of sufficient quantities of hydrocarbons leads to the primary fluid migration. For series of our experiments we selected mainly siliceous-carbonate composition shale rocks from Domanic horizon of South-Tatar arch. Rock samples were heated in the pyrolyzer to temperatures closely corresponding to different catagenesis stages. X-ray microtomography method was used to monitor changes in the morphology of the pore space within studied shale rocks. By routine measurements we made sure that all samples (10 in total) had similar composition of organic and mineral phases. All samples in the collection were grouped according to initial structure and amount of organics and processed separately to: 1) study the influence of organic matter content on the changing morphology of the rock under thermal effects; 2) study the effect of initial structure on the primary migration processes for samples with similar organic matter content. An additional experiment was conducted to study the dynamics of changes in the structure of the pore space and prove the validity of our approach. At each stage of heating the morphology of altered rocks was characterized by formation of new pores and channels connecting primary voids. However, it was noted that the samples with a relatively low content of the organic matter had less changes in pore space morphology, in contrast to rocks with a high organic content. Second part of the study also revealed significant differences in resulting pore structures depending on initial structure of the unaltered rocks and connectivity of original

  1. Sources and distribution of polycyclic aromatic hydrocarbons in a an urbanized tropical estuary and adjacent shelf, Northeast of Brazil.

    PubMed

    Maciel, Daniele Claudino; de Souza, José Roberto Botelho; Taniguchi, Satie; Bícego, Márcia Caruso; Zanardi-Lamardo, Eliete

    2015-12-15

    Located in Northeastern Brazil, the Capibaribe Estuarine System is an important ecosystem that supplies food and protection for nursery of several species with ecological and economic importance. It is located inside an urbanized area, receives untreated domestic and industrial effluents, and houses some marinas and the Harbor of Recife, which are very important to national and international communities. The distribution and sources of PAHs were investigated in sediments from CES and adjacent shelf. Total PAH concentrations ranged from non-detectable to 497.6 μg g(-1). Pyrolytic sources predominated in most of sites, but petrogenic PAHs were also recorded. The concentration decrease of PAHs toward adjacent shelf suggests that the main source of these compounds is in the upper portion of estuary, where there is an intense discharge of sewage, but atmospheric input also seems to be relevant to the area. The results reinforce the important role of an estuary in contaminant retention.

  2. Hydrocarbon prospectivity in the Hellenic trench system: organic geochemistry and source rock potential of upper Miocene-lower Pliocene successions in the eastern Crete Island, Greece

    NASA Astrophysics Data System (ADS)

    Zelilidis, A.; Tserolas, P.; Chamilaki, E.; Pasadakis, N.; Kostopoulou, S.; Maravelis, A. G.

    2016-09-01

    Results of the current and already published studies suggest that the Tortonian in age deposits could serve a major source rocks (for both oil and gas) beneath the Messinian evaporites in the Hellenic trench system. Additionally, the strong terrestrial input in Pliocene deposits could lead to the production of biogenic gas, similar to the Po basin in Adriatic Sea (Italy). In the current study, fourteen samples from late Miocene Faneromeni section and twelve samples from the early Pliocene Makrilia section in eastern Crete were collected in order to evaluate their hydrocarbon generation potential. For this purpose, Rock-Eval analysis and characterization of the organic matter were performed. The results document a clear distinction between the two sections. Faneromeni section contains organic matter of kerogen type III, whereas the Makrilia section contains organic matter of kerogen type IV. The HI/TOC plot diagram, in both sections, indicates poor oil generating potential, with the exception of several samples showing fair to good gas and oil potential. Although thermal maturities of the samples from the two successions are similar, according to the T max values, samples from Faneromeni succession exhibit higher hydrogen index values, indicating a better quality of organic matter in terms of hydrocarbon generation. Very low obtained concentrations of bitumen (mg/g of rock), as well as the predominance of NSO compounds, compared to the saturates and aromatics, indicate low maturation level. The n-alkanes profiles exhibit a bimodal distribution, indicating a mixed origin (marine and terrestrial) of the organic matter in both areas. Terrestrial organic matter input is more pronounced in Makrilia section. The analysis of saturated biomarkers indicates that Faneromeni deposits were accumulated under constant organic matter input in an environment influenced by cyclic changes (from marine to lagoon origin and vice versa). Faneromeni section corresponds to a restricted

  3. Emission and profile characteristic of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from stationary sources based on dilution sampling

    NASA Astrophysics Data System (ADS)

    Kong, Shaofei; Ji, Yaqin; Li, Zhiyong; Lu, Bing; Bai, Zhipeng

    2013-10-01

    The mass concentrations and profile characteristic for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 from stack gases for six types of stationary sources in Shandong Province, China were studied by a dilution sampling system and GC-MS analysis method from February to March in 2010. The mass concentrations of PM2.5 and PM10 from the six types of stationary sources varied in 8.2-79.4 mg m-3 and 23.3-156.7 mg m-3, respectively. The total mass concentrations of analyzed PAHs in PM2.5 and PM10 were in the ranges of 0.40-94.35 μg m-3 and 9.16-122.91 μg m-3. The most toxic ashes were from sinter and coke oven for both PM2.5 and PM10 with high carcinogenic PAHs concentrations. BbF, Phe, NaP, BghiP, Pyr, BaP and BeP were abundant which was different from formers and one of the key reasons may be the differences of sampling methods. Diversities in PAHs compositions existed between fly ashes within PM2.5 and PM10 fractions for coke oven according to coefficient of divergence (CD) values. PAHs profiles for PM10 emitted from coke oven were different from those of other stationary sources (with CD values higher than 0.35) and for PM2.5, it was the same for sinter (with most CD values close to 0.30). There existed similar PAHs markers for fine particles emitted from stationary sources excepted for the sinter. For PM10, PAHs markers were primary 3-ring PAHs except for the coke oven with BbF, IND and BghiP as its signatures. Diagnostic ratios of BaA/(BaA + Chr), Flu/(Flu + Pyr), BaP/(BaP + BeP), BeP/BghiP and IND/(IND + BghiP) could be not well distinguished for the six types of stationary sources with the maximum/minimum ratios lower than 2 for both PM2.5 and PM10 of fly ashes which should be not used for source identification studies. The mass concentrations and source profiles of PAHs should be updated timely for size-differentiated fly ashes from various stationary sources by dilution sampling method.

  4. Bioavailability of Polycyclic Aromatic Hydrocarbons and their Potential Application in Eco-risk Assessment and Source Apportionment in Urban River Sediment

    PubMed Central

    Yang, Xunan; Yu, Liuqian; Chen, Zefang; Xu, Meiying

    2016-01-01

    Traditional risk assessment and source apportionment of sediments based on bulk polycyclic aromatic hydrocarbons (PAHs) can introduce biases due to unknown aging effects in various sediments. We used a mild solvent (hydroxypropyl-β-cyclodextrin) to extract the bioavailable fraction of PAHs (a-PAHs) from sediment samples collected in Pearl River, southern China. We investigated the potential application of this technique for ecological risk assessments and source apportionment. We found that the distribution of PAHs was associated with human activities and that the a-PAHs accounted for a wide range (4.7%–21.2%) of total-PAHs (t-PAHs), and high risk sites were associated with lower t-PAHs but higher a-PAHs. The correlation between a-PAHs and the sediment toxicity assessed using tubificid worms (r = −0.654, P = 0.021) was greater than that from t-PAH-based risk assessment (r = −0.230, P = 0.472). Moreover, the insignificant correlation between a-PAH content and mPEC-Q of low molecular weight PAHs implied the potiential bias of t-PAH-based risk assessment. The source apportionment from mild extracted fractions was consistent across different indicators and was in accordance with typical pollution sources. Our results suggested that mild extraction-based approaches reduce the potential error from aging effects because the mild extracted PAHs provide a more direct indicator of bioavailability and fresher fractions in sediments. PMID:26976450

  5. Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in the water and suspended sediments from the middle and lower reaches of the Yangtze River, China.

    PubMed

    Wang, Chenglong; Zou, Xinqing; Zhao, Yifei; Li, Baojie; Song, Qiaochu; Li, Yali; Yu, Wenwen

    2016-09-01

    Samples were collected from the middle and lower reaches of the Yangtze River, China, to study the concentrations, distributions, and compositions of 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM). We also evaluated sources of the PAHs and their potential toxicity. Total concentrations of the PAHs (ΣPAHs) in water ranged from 17.33 to 77.12 ng L(-1), and in SPM, the levels ranged from 595.91 to 2473.74 ng g(-1). Total concentrations of seven carcinogenic PAHs (ΣCPAHs) ranged from 7.63 to 13.02 ng L(-1) in water and 276.55 to 1216.89 ng g(-1) in SPM. PAH levels in water samples were relatively low, and those in the lower reaches were higher than in the middle reaches. SPM samples had higher levels of PAHs, especially in the lower reaches and in Dongting Lake and Poyang Lake. Principal component analysis (PCA) with multiple linear regression analysis (MLR) was performed to quantitatively characterize the PAH sources. Two factors and their contributions were identified from water samples. Coal and wood combustion accounted for 74.1 % of the PAHs, and petroleum emissions explained 25.9 % of the PAHs. Three source factors were identified from SPM samples: these were vehicular emissions (46.3 % of PAHs), wood and coal combustion (40.4 % of PAHs), and petrogenic sources (13.3 %). Ecological risk assessment indicated that a moderate undesirable impact will be caused by PAHs, and some control measures and remedial actions should be conducted.

  6. Polycyclic aromatic hydrocarbons in road-deposited sediments, water sediments, and soils in Sydney, Australia: Comparisons of concentration distribution, sources and potential toxicity.

    PubMed

    Nguyen, Thuy Chung; Loganathan, Paripurnanda; Nguyen, Tien Vinh; Vigneswaran, Saravanamuthu; Kandasamy, Jaya; Slee, Danny; Stevenson, Gavin; Naidu, Ravi

    2014-06-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) considered as priority environmental pollutants were analysed in surface natural soils (NS), road-deposited sediments (RDS), and water sediments (WS) at Kogarah in Sydney, Australia. Comparisons were made of their concentration distributions, likely sources and potential toxicities. The concentrations (mg/kg) in NS, RDS, and WS ranged from 0.40 to 7.49 (mean 2.80), 1.65 to 4.00 (mean 2.91), and 0.49 to 5.19 (mean 1.76), respectively. PAHs were dominated by relatively high molecular weight compounds with more than three fused benzene rings, indicating that high temperature combustion processes were their predominant sources. The proportions of high molecular weight PAHs with five or six fused benzene rings were higher in NS than in RDS, whereas the low molecular weight PAHs were higher in RDS. Concentrations of all PAHs compounds were observed to be the lowest in WS. The concentrations of most of the high molecular weight PAHs significantly correlated with each other in RDS and WS. All PAHs (except naphthalene) were significantly correlated in NS suggesting a common PAH source. Ratios for individual diagnostic PAHs demonstrated that the primary source of PAHs in WS and NS was of pyrogenic origin (combustion of petroleum (vehicle exhaust), grass, and wood) while in RDS it was petrogenic (i.e. unburned or leaked fuel and oil, road asphalt, and tyre particles) as well as pyrogenic. The potential toxicities of PAHs calculated using a toxicity equivalent quotient (TEQ) were all low but higher for NS compared to WS and RDS.

  7. Effects of urbanization on gaseous and particulate polycyclic aromatic hydrocarbons and polychlorinated biphenyls in a coastal city, China: levels, sources, and health risks.

    PubMed

    Hong, Youwei; Chen, Jinsheng; Zhang, Fuwang; Zhang, Han; Xu, Lingling; Yin, Liqian; Chen, Yanting

    2015-10-01

    Gas/particle distributions of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured in Xiamen from May 2009 to March 2010 to evaluate the impacts of urbanization on the fate of persistent organic pollutants (POPs) in the atmospheric environment. In a newly developing area (NDA), the concentrations of 16 PAHs (gas + particle) were significantly higher than that a historically urbanized area (HUA) (p value <0.05), while the trend of 28 PCBs was reversed. Diagnostic ratios and principle component analysis (PCA) implied that atmospheric PAHs in the NDA were mainly derived from petrogenic combustion, including mixed sources of vehicle emissions, biomass burning and oil combustion, while pyrogenic combustion (e.g., traffic and coal combustion) was considered the major source of PAHs in the HUA. Atmospheric PCBs in both HUA and NDA were dominated by TriCBs and PeCBs related to the use of commercial mixtures (Aroclors 1242 and 1254). Based on the toxicological equivalent factor (TEF) approach, total benzo[a]pyrene equivalent values in the HUA and NDA were 1.12 and 2.02 ng m(-3), respectively, exceeding the standard threshold values (1.0 ng m(-3)) of China and WHO. Average daily intake of dioxin-like compounds was 0.2 pg kg(-1) day(-1) in the HUA, which are below the WHO tolerable daily intake level. The results showed that the contribution to the toxic equivalency (TEQ) was dominated by PCB169, PCB105, and PCB81.

  8. Distribution, Sources, and Association of Polycyclic Aromatic Hydrocarbons, Black Carbon, and Total Organic Carbon in Size-Segregated Soil Samples Along a Background–Urban–Rural Transect

    PubMed Central

    Ray, Sharmila; Khillare, Pandit Sudan; Kim, Ki-Hyun; Brown, Richard J.C.

    2012-01-01

    Abstract Soil samples were collected over a year-long period along a background–urban–rural transect in Delhi, India for the analysis of polycyclic aromatic hydrocarbons (PAHs), black carbon (BC), and total organic carbon (TOC) in five grain size fractions, x, in μm of 0≤x<53 (I), 53≤x<250 (II), 250≤x<500 (III), 500≤x<2000 (IV), and their sum (total: T). Maximum concentrations of PAH, BC, and TOC were observed in the smallest fraction (I) comprising silt and clay, irrespective of site or season. Results of the molecular diagnostic ratios and principal component analysis (PCA) identified coal, wood, biomass burning, and vehicular emissions as major sources of PAHs at all the three sites, while BC/TOC ratios pointed toward biomass combustion as the chief source of carbonaceous species. This work presents the first such rural-urban transect study considering PAH, BC, and TOC in soil. PMID:23133309

  9. Temporal and spatial distribution, sources, and potential health risks of ambient polycyclic aromatic hydrocarbons in the Yangtze River Delta (YRD) of eastern China.

    PubMed

    Niu, Shan; Dong, Liang; Zhang, Lifei; Zhu, Chaofei; Hai, Reti; Huang, Yeru

    2017-04-01

    In this study, from July 2011 to June 2012, 31 sampling sites were identified in order to investigate the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs), as well as to evaluate their potential health risks in the cities of Suzhou, Wuxi, and Nantong, which are located in the Yangtze River Delta (YRD). The samples were collected by means of passive air sampling (PAS), and the contents of 15 PAHs were detected by gas chromatography-mass spectrometry. The ∑15PAHs concentrations were found to range from 6.48 to 154 ng m(-3), with an average value of 56.8 ± 14.8 ng m(-3). The pollution levels in Suzhou and Nantong were higher than those in Wuxi. Furthermore, the concentrations of the PAHs in the urban sites were determined to be higher than those in the suburban sites for ambient air. The seasonal average contents were found to be at a maximum in autumn, with concentrations reaching 74.1 ng m(-3). Vehicle emissions and coal/biomass combustion were the dominant sources of the PAHs in the ambient air, with the contributions of 48% and 46%, respectively. The BaP TEQ (0.88 ng m(-3)) was found to have surpassed the Chinese and Japanese dioxin emission limit, and in doing so, may have caused a certain degree of risk to human health.

  10. Distributions and fate of chlorinated pesticides, biomarkers and polycyclic aromatic hydrocarbons in sediments along a contamination gradient from a point-source in San Francisco Bay, California

    USGS Publications Warehouse

    Pereira, W.E.; Hostettler, F.D.; Rapp, J.B.

    1996-01-01

    The distribution and fate of chlorinated pesticides, biomarkers, and polycyclic aromatic hydrocarbons (PAHs) in surficial sediments along a contamination gradient in the Lauritzen Canal and Richmond Harbor in San Francisco Bay was investigated. Compounds were identified and quantified using gas chromatography-ion trap mass spectrometry. Biomarkers and PAHs were derived primarily from weathered petroleum. DDT was reductively dechlorinated under anoxic conditions to DDD and several minor degradation products, DDMU, DDMS, and DDNU. Under aerobic conditions, DDT was dehydrochlorinated to DDE and DBP. Aerobic degradation of DDT was diminished or inhibited in zones of high concentration, and increased significantly in zones of lower concentration: Other chlorinated pesticides identified in sediment included dieldrin and chlordane isomers. Multivariate analysis of the distributions of the DDTs suggested that there are probably two sources of DDD. In addition, DDE and DDMU are probably formed by similar mechanisms, i.e. dehydrochlorination. A steep concentration gradient existed from the Canal to the Outer Richmond Harbor, but higher levels of DDD than those found in the remainder of the Bay indicated that these contaminants are transported on particulates and colloidal organic matter from this source into San Francisco Bay. Chlorinated pesticides and PAHs may pose a potential problem to biota in San Francisco Bay.

  11. Influence of urban activities on polycyclic aromatic hydrocarbons in precipitation: distribution, sources and depositional flux in a developing metropolis, Fortaleza, Brazil.

    PubMed

    Cavalcante, Rivelino M; Sousa, Francisco W; Nascimento, Ronaldo F; Silveira, Edilberto R; Viana, Rommel B

    2012-01-01

    We measured polycyclic aromatic hydrocarbons (PAHs) in bulk precipitation in the Fortaleza metropolitan area, Ceará, Brazil, for the first time. Because little information is available concerning PAHs in tropical climatic regions, we assessed their spatial distribution and possible sources and the influence of urban activities on the depositional fluxes of PAHs in bulk precipitation. The concentrations of individual and total PAHs (Σ(PAHs)) in bulk precipitation ranged from undetectable to 133.9 ng.L(-1) and from 202.6 to 674.8 ng.L(-1), respectively. The plume of highest concentrations was most intense in a zone with heavy automobile traffic and favorable topography for the concentration of emitted pollutants. The depositional fluxes of PAHs in bulk precipitation calculated in this study (undetectable to 0.87 μg.m(-2).month(-1)) are 4 to 27 times smaller than those reported from tourist sites and industrial and urban areas in the Northern Hemisphere. Diagnostic ratio analyses of PAH samples showed that the major source of emissions is gasoline exhaust, with a small percentage originating from diesel fuel. Contributions from coal and wood combustion were also found. Major economic activities appear to contribute to pollutant emissions.

  12. Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the intertidal zone of Bohai Bay, Northeast China: Spatial distribution, composition, sources and ecological risk assessment.

    PubMed

    Qian, Xiao; Liang, Baocui; Fu, Wenjun; Liu, Xinhui; Cui, Baoshan

    2016-11-15

    Polycyclic aromatic hydrocarbons (PAHs) can enter intertidal zones by various pathways and pose potential threats to intertidal ecosystem. We investigated distribution, composition, sources and risk assessment of PAHs in intertidal surface sediments of Bohai Bay. Total PAH concentrations ranged from 37.2ng·g(-1) to 206.6ng·g(-1), among which high values occurred near Nanpaishuihe River Estuary and Haihe River Estuary. The composition patterns of PAHs were characterized by the predominance of 3-ring and 4-ring PAHs, and acenaphthylene was the most dominant component. Diagnostic ratios and principal component analysis have confirmed that PAH contaminants originated from mixed sources, and the major was local combustion. The mean benzo(a)pyrene equivalent concentration of total PAHs in intertidal sediments was 15.67ng·g(-1), which was mostly contributed by seven carcinogenic PAHs. According to ecological risk assessment, negative effects related to acenaphthylene would occur occasionally in partial survey regions of the study.

  13. 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.

  14. Polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from urban and industrial areas of Asaluyeh Harbor, Iran: distribution, potential source and ecological risk assessment.

    PubMed

    Raeisi, Alireza; Arfaeinia, Hossein; Seifi, Morteza; Shirzad-Siboni, Mehdi; Keshtkar, Mozhgan; Dobaradaran, Sina

    The distribution and toxicity levels of 16 EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) in the sediments of Asaluyeh shore, Iran were investigated. The total concentrations of the PAHs in surface sediments ranged from 1,054 to 17,448 ng/g dry weights with a mean concentration of 8,067 ng/g. The spatial distribution of PAHs showed that PAH levels are much higher in the industrial areas in comparison with urban areas. Based on diagnostic ratios, pyrogenic activities were dominant sources of PAHs pollution in sediments comparing petroleum sources. The toxic equivalent concentrations (TEQ Carc) of PAHs ranged from 172 to 2,235 ng TEQ/g with mean value of 997.9. Toxicity levels were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Samples were collected from industrial and urban stations in Asaluyeh shores. According to SQGs, ΣPAHs concentrations in sediments of urban areas were below the ERL (effects range low), but the industrial samples had ΣPAHs concentrations between ERL and ERM (effects range median). Furthermore, ΣHPAHs (heavy PAHs) and some individual PAHs in some industrial stations exceeded ERM, indicating adverse ecological risk effects frequently occur. Findings demonstrate that the surface sediment from Asaluyeh shore is highly to very highly contaminated with PAHs.

  15. Characterizations, relationship, and potential sources of outdoor and indoor particulate matter bound polycyclic aromatic hydrocarbons (PAHs) in a community of Tianjin, Northern China.

    PubMed

    Han, B; Bai, Z; Liu, Y; You, Y; Xu, J; Zhou, J; Zhang, J; Niu, C; Zhang, N; He, F; Ding, X

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs.

  16. Alternative energy sources II; Proceedings of the Second Miami International Conference, Miami Beach, Fla., December 10-13, 1979. Volume 7 - Hydrocarbon conversion

    NASA Astrophysics Data System (ADS)

    Veziroglu, T. N.

    Consideration is given to such topics as coal gasification and liquefaction, the combustion of alcohol fuels, hydrocarbon upgrading and combustion technology, novel engines using hydrocarbon fuel, and hydrocarbons economics and planning. Particular papers are presented on the role of high-Btu coal gasification technology, ethanol from municipal cellulosic wastes, the fluidized bed combustion of coal, the behavior of gas distribution equipment in hydrogen service, and the economics of advanced technologies for electricity generation from coal.

  17. Preliminary hydrocarbon source rock assessment of the Paleozoic and Mesozoic formations of the western Black Sea region of Turkey

    SciTech Connect

    Harput, B.O.; Demirel, I.H.; Karayigit, A.I.; Aydin, M.; Sahintuerk, O.; Bustin, R.M.

    1999-12-01

    Source rock maturity and potential of Paleozoic and Mesozoic formations in the Eregli, Zonguldak, Bartin, Ulus, and Eflani subregions of the western Black Sea region (WBSR), have been investigated by rock-eval pyrolysis, reflected-light microscopy, and palynofacies analyses. The % Ro values of dispersed organic matter of the Paleozoic formations primarily range from 0.72 to 1.8%, but values as high as 2.6% occur locally in the Silurian Findikli Formation in the Eregli subregion. The % Ro values of Namurian-Westphalian coal seams in the K20/H well drilled in the Zonguldak subregion range from 0.87 to 1.52%, with increasing depth consistent with sedimentary depth of burial. Most Cretaceous age samples have reflectance values ranging from 0.44 to 1.6% Ro that indicates they are marginally mature to mature with respect to the oil window. Rock-eval pyrolysis demonstrates that the Paleozoic formations have limited oil-generation potential (HI values {le} 200 mg HC/g C{sub org}), but good gas potential (TOC values up to 3%). Cretaceous formations have better petroleum source rock characteristics, but they too are primarily gas prone. Variations in the source rock maturity probably reflect variable burial histories in different localities of the WBSR.

  18. Concentration, distribution and source apportionment of atmospheric polycyclic aromatic hydrocarbons in the southeast suburb of Beijing, China.

    PubMed

    Zhang, Shucai; Zhang, Wei; Wang, Kaiyan; Shen, Yating; Hu, Lianwu; Wang, Xuejun

    2009-04-01

    Total suspended particle samples and gas phase samples were collected at three representative sampling sites in the southeastern suburb of Beijing from March 2005 to January 2006. The samples were analyzed for 16 US EPA priority PAHs using GC/MS. Concentrations of Sigma PAHs in particle and gas phases were 0.21-1.18 x 10(3) ng m(-3) and 9.5 x 10(2) ng-1.03 x 10(5) ng m(-3), respectively. PAH concentrations displayed seasonal variation in the order of winter>spring>autumn>summer for particle phase, and winter>autumn>summer>spring for gas phase. Partial correlation analysis indicates that PAH concentrations in particle phase are negatively correlated with temperature and positively correlated with air pollution index of SO(2). No significant correlation is observed between gas phase PAHs and the auxiliary parameters. Sources of PAH are identified through principal component analysis, and source contributions are estimated through multiple linear regression. Major sources of atmospheric PAHs in the study area include coal combustion, coke industry, vehicular emission and natural gas combustion.

  19. Polycyclic aromatic hydrocarbons (PAHs) in urban soils of the megacity Shanghai: occurrence, source apportionment and potential human health risk.

    PubMed

    Wang, Xue-Tong; Miao, Yi; Zhang, Yuan; Li, Yuan-Cheng; Wu, Ming-Hong; Yu, Gang

    2013-03-01

    A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8,650 ng g for ΣPAHs and 83.3 to 7,220 ng g for ΣPAHs, with mean values of 2420 and 1,970 ng g, respectively. DBalP and DBaeP may serve as markers for diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from diesel emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular emissions, respectively. The benzo[a]pyrene equivalent (BaP) concentrations ranged from 48.9-2,580 ng g for ΣPAHs, 7.02-869 ng g for ΣPAHs and 35.7-1,990 ng g for ΣDBPs. The BaP concentrations of ΣDBPs made up 72% of ΣPAHs. Nearly half of the soil samples showed concentrations above the safe BaP value of 600 ng g. Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.

  20. Sources and mass inventory of sedimentary polycyclic aromatic hydrocarbons in the Gulf of Thailand: Implications for pathways and energy structure in SE Asia.

    PubMed

    Hu, Limin; Shi, Xuefa; Qiao, Shuqing; Lin, Tian; Li, Yuanyuan; Bai, Yazhi; Wu, Bin; Liu, Shengfa; Kornkanitnan, Narumol; Khokiattiwong, Somkiat

    2017-01-01

    Surface sediments obtained from a matrix of 92 sample sites in the Gulf of Thailand (GOT) were analyzed for a comprehensive study of the distribution, sources, and mass inventory of polycyclic aromatic hydrocarbons (PAHs) to assess their input pathways and impacts of the regional land-based energy structure on the deposition of PAHs on the adjacent continental margins. The concentration of 16 PAHs in the GOT ranged from 2.6 to 78.1ng/g (dry weight), and the mean concentration was 19.4±15.1ng/g. The spatial distribution pattern of 16 PAH was generally consistent with that of sediment grain size, suggesting the influence of regional hydrodynamic conditions. Correlation and principal component analysis of the PAHs indicated that direct land-based inputs were dominantly responsible for the occurrence of PAHs in the upper GOT and the low molecular weight (LMW) PAHs in the coastal region could be from petrogenic sources. A positive matrix factorization (PMF) model apportioned five contributors: petroleum residues (~44%), biomass burning (~13%), vehicular emissions (~11%), coal combustion (~6%), and air-water exchange (~25%). Gas absorption may be a significant external input pathway for the volatile PAHs in the open GOT, which further implies that atmospheric loading could be important for the sink of PAHs in the open sea of the Southeast Asia (SE Asia). The different PAH source patterns obtained and a significant disparity of PAH mass inventory in the sediments along the East and Southeast Asia continental margins can be ascribed mainly to different land-based PAH emission features under the varied regional energy structure in addition to the depositional environment and climatic conditions.

  1. Distribution, sources, and potential risk of polycyclic aromatic hydrocarbons (PAHs) in drinking water resources from Henan Province in middle of China.

    PubMed

    Ma, Ying-ge; Cheng, Jin-ping; Jiao, Fei; Duo, Ke-xin; Rong, Zheng; Li, Ming; Wang, Wen-hua

    2008-11-01

    Distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in drinking water resources have been carried out for the first time in Henan Province, China. Water samples collected from four river systems and their tributaries, as well as groundwater resources, were analyzed according to EPA method 525.2. Total of 68 water samples were collected in 18 cities in Henan province in May, August and November, 2001. Concentrations of sum of 16 priority PAHs in water samples ranged from 15 to 844 ng/L with a mean value of 178 +/- 210 ng/L (n = 68). The spatial and temporal distribution of PAHs showed that the Huanghe and the Huaihe river systems had relatively higher concentrations of total PAHs. Higher concentrations of total PAHs were observed in August and November than in May, with respective mean values of 262, 232 and 33.6 ng/L. Ratios of Ant/(Ant + Phe) and Flur/(Flur + Pyr) were calculated to evaluate the possible sources of PAH contamination, which indicated that the coal combustion sources were the main contributors to PAHs in most drinking water resources. Some petrogenic (or pyrolytic) sources of PAHs were also found. The toxic equivalency factors (TEFs) were used to calculate benzo[a]pyrene equivalents (BaPE) for water samples. The average value of BaPE was 0.6 ng/L. The values in most stations were much lower than the guideline values in drinking water of Chinese Environmental Protection Agency (CEPA, 2.8 ng/L) and the US Environmental Protection Agency (US EPA, 200 ng/L). Overall, the drinking water resources in Henan province showed some carcinogenic potential.

  2. Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in the reservoir sediments after impoundment of Manwan Dam in the middle of Lancang River, China.

    PubMed

    An, NanNan; Liu, Shiliang; Yin, Yijie; Cheng, Fangyan; Dong, Shikui; Wu, Xiaoyu

    2016-08-01

    Polycyclic aromatic hydrocarbons (PAHs) have received increasing attentions owing to their carcinogenicity, teratogenicity and environmental toxicity. The studies on the spatial variations, sources identification and potential ecological risk assessment of PAHs in the reservoir sediments after dam construction are becoming new hotpots. Sixteen PAHs contamination levels were investigated from 15 sample sections in the sediments of Manwan Reservoir in the middle of Lancang River, China. Total concentrations of 16 PAHs ranged from 14.4 to 137.7 ng g(-1) dw with a mean concentration of 70.68 ng g(-1) dw. The areas with residential settlement at large tributaries and near dam had higher PAHs concentrations. In the sight of classification of PAHs pollution levels, the sediments of Manwan Reservoir could be considered as low to moderate PAHs polluted levels. One-way analysis of variance for spatial analysis revealed that there were no significant differences (P < 0.05) for 16 PAHs at the reservoir head, centre and tail. Moreover, no significant differences (P < 0.05) were found for most individual PAH at the mainstream and tributaries except that BaP showed significant differences (P < 0.05) in the mainstream and tributaries. According to the diagnostic ratios, the possible pollution sources of PAHs in Manwan Reservoir might be mixed, primarily including the petroleum source and coal combustion. As compared with sediment quality guidelines, the observed concentrations of PAHs in all sample sections did not exceed the effects range low (ERL) and the threshold effect level (TEL) values, suggesting that there were little harmful biological toxic effects on the aquatic organisms in Manwan Reservoir. The study provided a comprehensive overview on the PAHs contaminations on the reservoir sediments in the middle Lancang River, which may have an important significances on the international river management.

  3. Particulate polycyclic aromatic hydrocarbons in the Atlantic and Indian Ocean atmospheres during the Indian Ocean Experiment and Aerosols99: Continental sources to the marine atmosphere

    NASA Astrophysics Data System (ADS)

    Crimmins, Bernard S.; Dickerson, Russell R.; Doddridge, Bruce G.; Baker, Joel E.

    2004-03-01

    Polycyclic aromatic hydrocarbons (PAHs), mutagenic compounds predominantly derived from combustion, have been used as markers of combustion sources to the atmosphere. Marine aerosol collected aboard the NOAA R/V Ronald Brown during the Aerosols99 and the Indian Ocean Experiment (INDOEX) projects was analyzed for PAHs to assess the continental impact of combustion-derived particulate matter on the Atlantic and Indian Ocean atmospheres. PAH concentrations in the Atlantic and southern Indian Ocean atmospheres were consistent and low, ranging from <0.45 pg/m3 for coronene to 30 pg/m3 for 9, 10-dimethylanthracene. PAH concentrations increased ten fold as the ship crossed the Intertropical Convergence Zone (ITCZ) into the northern Indian Ocean, indicating an increased anthropogenic influence. PAH concentrations over the northern Indian Ocean atmosphere were approximately an order of magnitude greater than those in the northern Atlantic Ocean atmosphere. PAH composition profiles over the northern Indian Ocean were specific to wind regimes and influenced by a combination of biomass and fossil fuel combustion. This was supported by significant correlations between select PAHs and organic carbon (OC), elemental carbon (EC), SO4-2 and K+ for particular wind regimes. Indeno[1,2,3-cd]pyrene/EC ratios used as a combustion source marker suggest that fossil fuel combustion, rather than biomass burning, is the predominant source of PAHs to the Northern Hemisphere Indian Ocean atmosphere. Interestingly, fossil fuel consumption in the Indian sub-continent is a fraction of that in Europe and the United States but the soot and PAH levels in the adjacent Northern Indian Ocean atmosphere are significantly greater than those in the Northern Atlantic atmosphere.

  4. Relative source allocation of TDI to drinking water for derivation of a criterion for chloroform: a Monte-Carlo and multi-exposure assessment.

    PubMed

    Niizuma, Shun; Matsui, Yoshihiko; Ohno, Koichi; Itoh, Sadahiko; Matsushita, Taku; Shirasaki, Nobutaka

    2013-10-01

    Drinking water quality standard (DWQS) criteria for chemicals for which there is a threshold for toxicity are derived by allocating a fraction of tolerable daily intake (TDI) to exposure from drinking water. We conducted physiologically based pharmacokinetic model simulations for chloroform and have proposed an equation for total oral-equivalent potential intake via three routes (oral ingestion, inhalation, and dermal exposures), the biologically effective doses of which were converted to oral-equivalent potential intakes. The probability distributions of total oral-equivalent potential intake in Japanese people were estimated by Monte Carlo simulations. Even when the chloroform concentration in drinking water equaled the current DWQS criterion, there was sufficient margin between the intake and the TDI: the probability that the intake exceeded TDI was below 0.1%. If a criterion that the 95th percentile estimate equals the TDI is regarded as both providing protection to highly exposed persons and leaving a reasonable margin of exposure relative to the TDI, then the chloroform drinking water criterion could be a concentration of 0.11mg/L. This implies a daily intake equal to 34% of the TDI allocated to the oral intake (2L/d) of drinking water for typical adults. For the highly exposed persons, inhalation exposure via evaporation from water contributed 53% of the total intake, whereas dermal absorption contributed only 3%.

  5. A Field Scale Investigation of Enhanced Petroleum Hydrocarbon Biodegradation in the Vadose Zone Combining Soil Venting as an Oxygen Source with Moisture and Nutrient Addition

    DTIC Science & Technology

    1990-01-01

    AND SUBTITLF A Field Scale Investigation of Enhanced 5. FUNDING NUMBERS Petroleum Hydrocarbon Biodegradation in the Vadose Zone Combining Soil Venting...24 Enhanced Biodegradation Through Soil Venting ...................... 30 MATERIALS AND METHODS...378 ABSTRACT xx’ A Field Scale Investigation of Enhanced Petroleum Hydrocarbon Biodegradation in the Vadose Zone Combining Soil Venting as an

  6. Mesozoic hydrocarbon source rock studies of north Tarim, south Junggar, and Turpan basins, Xinjiang Uygur autonomous region, northwestern China

    SciTech Connect

    Hendrix, M.S.; Xiao, Z.; Liang, Y.; Graham, S.A.; Carroll, A.R.; Chu, J.; McKnight, C.

    1989-03-01

    Ongoing outcrop and accompanying pyrolysis studies of Mesozoic strata of the north Tarim, south Junggar, and Turpan retroarc foreland basins, northwestern China, have demonstrated the existence of potential oil-prone and gas-prone petroleum source rocks. Lithologies include Jurassic coals from all three basins and Triassic coals from Tarim. Jurassic coals collected from the Mesozoic depocenters of the Junggar and Tarim basins are oil prone, yielding S/sub 2//S/sub 2+3/ values that range from 0.80 to 0.99 and average 0.96, hydrogen index (HI) values that range from 117.9 to 213.4 and average 150.8, and oxygen index (OI) values that range from 1.1 to 31.6 and average 7.67. In contrast, Triassic coals of Tarim and Jurassic coals of Turpan contain more conventional type III gas-prone kerogens and yield S/sub 2//S/sub 2+3/ values ranging from 0.04 to 0.52 and averaging 0.22, HI values ranging from 3.2 to 130.2 with a mean of 33.6, and OI values ranging from 30.9 to 223.7 and averaging 115.9. Coals of all three basins are slightly immature to mature with respect to oil generation, as indicated by T/sub max/ values ranging from 425/degrees/ to 449/degrees/C (average = 343/degrees/C) and vitrinite reflectance values ranging from 0.51 to 0.64 (average = 0.57). Thus, given the widespread abundance and significant thicknesses of Mesozoic and especially Jurassic coals in all three basins, it is very likely that Mesozoic contributions to Xinjiang's oil and gas reserves are significant. This is particularly important in the north Tarim basin, where recent Chinese oil and gas discoveries have been made and the existence of significant pre-Mesozoic source beds remains unproven.

  7. Polycyclic aromatic hydrocarbons (PAHs) in multimedia environment of Heshan coal district, Guangxi: distribution, source diagnosis and health risk assessment.

    PubMed

    Huang, Huan-Fang; Xing, Xin-Li; Zhang, Ze-Zhou; Qi, Shi-Hua; Yang, Dan; Yuen, Dave A; Sandy, Edward H; Zhou, Ai-Guo; Li, Xiao-Qian

    2016-10-01

    Mining activities are among the major culprits of the wide occurrences of soil and water pollution by PAHs in coal district, which have resulted in ecological fragilities and health risk for local residents. Sixteen PAHs in multimedia environment from the Heshan coal district of Guangxi, South China, were measured, aiming to investigate the contamination level, distribution and possible sources and to estimate the potential health risks of PAHs. The average concentrations of 16 PAHs in the coal, coal gangue, soil, surface water and groundwater were 5114.56, 4551.10, 1280.12 ng g(-1), 426.98 and 381.20 ng L(-1), respectively. Additionally, higher soil and water PAH concentrations were detected in the vicinities of coal or coal gangue dump. Composition analysis, isomeric ratio, Pearson correlation analysis and principal component analysis were performed to diagnose the potential sources of PAHs in different environmental matrices, suggesting the dominant inputs of PAHs from coal/coal combustion and coal gangue in the soil and water. Soil and water guidelines and the incremental lifetime risk (ICLR) were used to assess the health risk, showing that soil and water were heavily contaminated by PAHs, and mean ICLRcoal/coal-gangue and mean ICLRsoil were both significantly higher than the acceptable levels (1 × 10(-4)), posing high potential carcinogenic risk to residents, especially coal workers. This study highlights the environmental pollution problems and public health concerns of coal mining, particularly the potential occupational health hazards of coal miners exposed in Heshan.

  8. Concentrations of heavy metals and polycyclic aromatic hydrocarbons in needles of Masson pine (Pinus massoniana L.) growing nearby different industrial sources.

    PubMed

    Sun, Fangfang; Wen, Dazhi; Kuang, Yuanwen; Li, Jiong; Li, Jianli; Zuo, Weidong

    2010-01-01

    Emissions from industrial activities pose a serious threat to human health and impose the need for monitoring both inorganic and organic pollutants in industrial areas. We selected Masson pine (Pinus massoniana L.) as potential biomonitor and collected the current (C) and previous year (C+1) needles from three industrial sites dominated by petrochemical, ceramics manufacturing, and iron and steel smelting plants and one remote site to determine heavy metals (Cu, Cd, Pb, Zn, Cr, Ni and Co) and polycyclic aromatic hydrocarbons (PAHs) in unwashed and water-washed needles. Both unwashed and washed C+1 needles showed generally higher concentrations of heavy metals and PAHs than C needles, although the washed needles more clearly spotlighted the accumulation effect of PAHs over exposure time. Water-washing resulted in a significant decrease in needle PAH concentrations with more significant effects shown in C needles. By contrast, needle heavy metal concentrations were much less affected by washing. Although heavy metals and PAHs might differ in adsorption and uptake strategies, their higher concentrations in the needles at the industrial sites indicated conspicuous contamination due to industrial emissions there. The PAH distribution patterns in pine needles accorded with the real types of energy consumption in the study sites and were efficiently used for pinpointing local pollutant sources.

  9. Polycyclic aromatic hydrocarbons in urban soils of different land uses in Beijing, China: distribution, sources and their correlation with the city's urbanization history.

    PubMed

    Liu, Shaoda; Xia, Xinghui; Yang, Lingyan; Shen, Mohai; Liu, Ruimin

    2010-05-15

    A total of 127 surface soil samples (0-20 cm) were collected from Beijing's urban district and determined for 16 polycyclic aromatic hydrocarbons (PAHs). The mean concentration of summation SigmaPAHs was 1802.6 ng g(-1) with a standard deviation of 1824.2 ng g(-1). Average summation SigmaPAHs concentration and the percentage of high-molecular weight PAHs (4-6-rings) decreased from inner city to exterior areas. This correlated with the urbanization history of Beijing's urban district and inferred an increasing trend of soil PAHs with accumulation time and age of the urban area. summation SigmaPAHs in different land uses decreased in an order as: culture and education area (CEA)>classical garden (CG), business area (BA)>residential area (RA), roadside area (RSA)>public green space (PGS). PAHs in CEA mainly came from coal combustion, while soils of RSA exhibited clear traffic emission characteristics. PAHs in other land uses came from mixed sources. Principle component analysis followed by multivariate linear regression indicated that coal combustion and vehicle emission contributed about 46.0% and 54.0% to PAHs in Beijing's urban soils, respectively. Risk assessment based on the Canadian soil criterion indicated a low contamination level of PAHs. However, higher contents in some sensitive land uses such as CEA and CG should draw enough attention.

  10. 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

  11. Distribution and sources of polycyclic aromatic hydrocarbons in sediments of the Mai Po Inner Deep Bay Ramsar Site in Hong Kong.

    PubMed

    Zhao, Zhen-Ye; Chu, Yan-ling; Gu, Ji-Dong

    2012-08-01

    The concentration of total polycyclic aromatic hydrocarbons (∑PAHs) and the 16 US EPA priority individual PAH compounds were analyzed in surface sediments from the Mai Po Inner Deep Bay, Ramsar Site of Hong Kong from December 2001 to Jun 2005, to investigate the spatial variability of anthropogenic pollutants. ∑PAHs concentrations ranged from 36.5 to 256.3 ng g(-1) dry weight with an average of 148.9 ng g(-1), comparable to other urbanized areas of the world, and there was little difference among different sampling times from December 2001 to June 2005. Based on comparison to the results from earlier study, it appears that a decrease of total PAHs concentration has occurred since 1992. Meanwhile, the concentrations of ∑PAHs were positive correlated with total organic carbon contents except sites F and G, suggesting the characteristics of the sediment influences the distribution and concentration of PAHs. There was relatively a good relationship among the individual PAHs and the compounds of fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]pyrene and indeno[cd]pyrene yielded a good correlation (r(2) > 0.5) with total PAHs. Principal component analysis and specific PAHs compound ratios (Phe/Ant vs. Flt/Pyr) indicate the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in the Mai Po Inner Deep Bay Nature Reserve.

  12. Coke industry and steel metallurgy as the source of soil contamination by technogenic magnetic particles, heavy metals and polycyclic aromatic hydrocarbons.

    PubMed

    Rachwał, Marzena; Magiera, Tadeusz; Wawer, Małgorzata

    2015-11-01

    Application of integrated magnetic, geochemical and mineralogical methods for qualitative and quantitative assessment of forest topsoils exposed to the industrial emissions was the objective of this manuscript. Volume magnetic susceptibility (κ) in three areas of southern Poland close to the coke and metallurgical plants was measured directly in the field. Representative topsoil samples were collected for further chemical and mineralogical analyses. Topsoil magnetic susceptibility in the studied areas depended mainly on the content of technogenic magnetic particles (TMPs) and decreased downwind at increasing distance from the emitters. In the vicinity of coking plants a high amount of polycyclic aromatic hydrocarbons (PAHs) was observed, especially the most carcinogenic ones with four- and five-member rings. No significant concentration of TMPs (estimated on the base of κ values) and heavy metals (HM) was observed in area where the coke plant was the only pollution source. In areas with both coke and metallurgical industry, higher amounts of TMPs, PAHs and HM were detected. Morphological and mineralogical analyses of TMPs separated from contaminated soil samples revealed their high heterogeneity in respect of morphology, grain size, mineral and chemical constitution. Pollution load index and toxicity equivalent concentration of PAHs used for soil quality assessment indicated its high level of pollution.

  13. Distribution and source recognition of polycyclic aromatic hydrocarbons in the sediments of Hsin-ta Harbour and adjacent coastal areas, Taiwan.

    PubMed

    Fang, Meng-Der; Lee, Chon-Lin; Yu, Chia-Shun

    2003-08-01

    Thirty-three sediment samples from Hsin-ta Harbour and neighboring coastal areas were analyzed by GC-MS for polycyclic aromatic hydrocarbons (PAHs). Total concentrations of 30 analyzed parental and alkylated PAHs ( summation operator PAH) varied from 98.1 to 3382 ng/g dry weight. MP/P (methylphenanthrenes/phenanthrene) values larger than 2 coincided with very low P/A (phenanthrene/anthracene) values at inner harbour stations, revealing that a significant portion of low molecular weight PAHs are probably from petrogenic pollution sources, specifically, illegal disposal of used motor oil. The 4,6-dimethyldibenzothiophene/3,6-dimethylphenanthrene (4,6-C(2)D/3,6-C(2)P) ratio is found to be more useful than the MP/P ratio in tracing petrogenic PAHs from the inner harbour area to the adjacent coastal environment. In addition, according to hierarchical cluster analysis, collected sediments cluster in three major groups, Off-shore Group, Near-shore Group and Inner Harbour Group. Three diagnostic ratios, 4,6-C(2)D/3,6-C(2)P, PER/ summation operator PAH (perylene to summation operator PAH) and BaA/CHR (benzo(a)anthracene/chrysene), representing petrogenic, biogenic and pyrogenic origins, are found to be effective in differentiating and characterizing sediments among the groups in this study. Enrichment of pyrogenic and petrogenic PAHs in sediments collected exhibits mixing or dilution, spatially, by biogenic (or natural) PAHs.

  14. [PUF passive air sampling of polycyclic aromatic hydrocarbons in atmosphere of the Yangtze River Delta, China: spatio-temporal distribution and potential sources].

    PubMed

    Zhang, Li-fei; Yang, Wen-long; Dong, Liang; Shi, Shuang-xin; Zhou, Li; Zhang, Xiu-lan; Li, Ling-ling; Niu, Shan; Huang, Ye-ru

    2013-09-01

    Atmosphere is regarded to be an important media in the environmental pollution research area. Passive air sampling was one of the effective complementary sampling techniques for the active high volume air sampler in recent decades. A regional scale investigation on the atmospheric polycyclic aromatic hydrocarbons (PAHs) was conducted in the Yangtze River Delta (YRD). Polyurethane foam based passive air samplers were used to collect the atmospheric PAHs from 31 sampling sites in this area. PAHs concentrations ranged from 10.1 ng x m(-1) to 367 ng x m(-3) in this study. The annual average concentration of benzo [a] pyrene (BaP) reached 2.25 ng x m(-3), which was two times higher exceeding the national standard, GB 3095-2012. The atmospheric PAHs during four seasons decreased in the following order: autumn > winter > spring > summer. Larger BaP excessive areas were found in autumn and winter than other seasons. Moreover, an obvious emission of BaP was confirmed during the winter time. Traffic related petroleum combustion, coal and biomass burning, and coke oven were identified as potential sources of atmospheric PAHs, contributing 38.1%, 42.4%, and 19.5%, respectively.

  15. Stable carbon isotopic ratio measurement of polycyclic aromatic hydrocarbons as a tool for source identification and apportionment--a review of analytical methodologies.

    PubMed

    Buczyńska, A J; Geypens, B; Van Grieken, R; De Wael, K

    2013-02-15

    The measurement of the ratio of stable isotopes of carbon ((13)C/(12)C expressed as a δ(13)C) in the individual components of a sample may be used as a means to identify the origin of these components. This article reviews the approaches and reports on the successes and failures of source identification and apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) with the use of compound-specific isotope analysis (CSIA). One of the conditions for a precise and accurate analysis of isotope ratios with the use of GC-C-IRMS is the need for well separated peaks, with no co-elutions, and reduced unresolved complex mixture (UCM). Additionally, special care needs to be taken for an investigation of possible isotope fractionation effects introduced during the analytical treatment of samples. With the above-mentioned problems in mind, this review discusses in detail and compares current laboratory methodologies, mainly in the extraction and subsequent clean-up techniques used for environmental samples (air particulate matter, soil and sediments). Sampling strategies, the use of isotopic internal standards and the ranges for precision and accuracy are also reported and discussed.

  16. Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends.

    PubMed

    Viñas, Lucía; Angeles Franco, M; Antonio Soriano, J; José González, J; Pon, Jordi; Albaigés, Joan

    2010-05-01

    The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (Sigma13 parent components) were in the range of 22-47528 mug/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC.

  17. Possible late middle Ordovician organic carbon isotope excursion: evidence from Ordovician oils and hydrocarbon source rocks, Mid-Continent and east-central United States

    SciTech Connect

    Hatch, J.R.; Jacobson, S.R.; Witzke, B.J.; Risatti, J.B.; Anders, D.E.; Watney, W.L.; Newell, K.D.; Vuletich, A.K.

    1987-11-01

    A possible coeval excursion in organic-matter delta/sup 13/C is recognized in different late Middle Ordovician lithologic facies over a distance of 480 mi (770 km), perhaps 930 mi (1500 km), in the Mid-Continent and east-central US. The large variability in the carbon isotope compositions of Ordovician oils from the Mid-Continent and east-central US is a direct result of the variable carbon isotope composition of organic matter in the Middle Ordovician hydrocarbon source rocks. The excursion in organic-matter delta/sup 13/C in late Middle Ordovician rocks may reflect significantly increased organic matter productivity and/or preservation. The excursion is not directly related to maceral composition of the organic matter. Limited dissolved CO/sub 2/ availability, possibly a result of continued high organic matter productivity, and limited circulation in the Middle Ordovician seas may have increased the size of the excursion in organic matter delta/sup 13/C. 5 figures, 4 tables.

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

    PubMed

    Chen, Yuyun; Jia, Rui; Yang, Shengke

    2015-11-06

    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.

  19. Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface water in industrial affected areas of the Three Gorges Reservoir, China.

    PubMed

    Zheng, Binghui; Ma, Yingqun; Qin, Yanwen; Zhang, Lei; Zhao, Yanmin; Cao, Wei; Yang, Chenchen; Han, Chaonan

    2016-12-01

    Water samples were collected from wastewater treatment plant (WWTP), drain water (DW), major tributaries (MT), and main course of the Yangtze River (MY) in areas of three industrial parks (IPs) in Chongqing city in the Three Gorges Reservoir (TGR). Sixteen EPA priority polycyclic aromatic hydrocarbon (PAH) pollutants were quantified to identify the effects of industrial activities on water quality of the TGR. The results showed that 11 individual PAHs were quantified and 5 PAHs (naphthalene (Nap), acenaphthylene (Acy), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd]pyrene (InP), and benzo[g,h,i]perylene (BgP)) were under detection limits in all of the water samples. Three-ring and four-ring PAHs were the most detected PAHs. Concentrations of individual PAHs were in the range of not detected (nd) to 24.3 ng/L. Total PAH concentrations for each site ranged from nd to 42.9 ng/L and were lower compared to those in other studies. The mean PAH concentrations for sites WWTP, DW, MT, and MY showed as follows: DW (25.9 ng/L) > MY (15.5 ng/L) > MT (14.0 ng/L) > WWTP (9.3 ng/L), and DW contains the highest PAH concentrations. Source identification ratios showed that petroleum and combustion of biomass coal and petroleum were the main sources of PAHs. The results of potential ecosystem risk assessment indicated that, although PAH concentrations in MT and MY are likely harmless to ecosystem, contaminations of PAHs in DW were listed as middle levels and some management strategies and remediation actions, like strengthen clean production processes and banning illegal sewage discharging activities, etc., should be taken to lighten the ecosystem risk caused by PAHs especially risks caused by water discharging drains.

  20. Constraining uncertainties about the sources and magnitude of ambient air exposures to polycyclic aromatic hydrocarbons (PAHs): The state of Minnesota as a case study

    SciTech Connect

    Lobscheid, Agnes B.; McKone, Thomas E.

    2004-02-01

    Emissions data are often lacking or uncertain for many airborne contaminants. Chemicals, such as polycyclic aromatic hydrocarbons (PAHs), emitted from combustion sources, fall into this category. Currently available ambient-air emission inventories of PAHs either fail to account for population-based activities (such as residential wood combustion and motor vehicle activity) and/or report ''total PAH'' or particulate organic matter emissions instead of individual compounds. We measure the degree of overlap between predicted concentrations from estimated emissions with measured concentrations. Our analysis is, based on probabilistic analysis of measured outdoor air concentrations with those predicted from mass-balance models. Based on available information, we estimate the relative magnitude of emissions from four major sources of PAHs to outdoor air- (1) on-road motor vehicles, including light-duty gasoline vehicles and diesel-powered buses and medium and heavy duty trucks; (2) residential wood combustion; and (3) power generation from external combustion boilers. We use the CalTOX regional multimedia mass-balance model to evaluate our emissions estimates in rural and urban regions of the state of Minnesota, USA. We compare model estimates of outdoor PAH airborne concentrations with those reported by the Minnesota Children's Pesticide Exposure Study (MNCPES). With these measured concentrations we probabilistically evaluate our emissions and interpret the reliability of our emissions estimates for specific PAHs. The median estimates of our predicted outdoor air concentrations agree within an order of magnitude of measured concentrations. For four representative PAHs, we were able to obtain a reasonable degree of overlap between empirical and predicted distributions of outdoor air concentrations. Our combination of models, emissions estimates, and empirical concentration data estimate exposure in a manner that is more reliable than any of these tools alone. Thereby

  1. Occurrence, sources, and potential human health risks of polycyclic aromatic hydrocarbons in agricultural soils of the coal production area surrounding Xinzhou, China.

    PubMed

    Zhao, Long; Hou, Hong; Shangguan, Yuxian; Cheng, Bin; Xu, Yafei; Zhao, Ruifen; Zhang, Yigong; Hua, Xiaozan; Huo, Xiaolan; Zhao, Xiufeng

    2014-10-01

    A comprehensive investigation of the levels, distribution patterns, and sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils of the coal production area surrounding Xinzhou, China, was conducted, and the potential human health risks associated with the levels observed were addressed. A total of 247 samples collected from agricultural soils from the area were analyzed for sixteen PAHs, including highly carcinogenic isomers. The PAH concentrations had a range of n.d. to 782ngg(-1), with a mean value of 202ngg(-1). The two-three ring PAHs were the dominant species, making up 60 percent of total PAHs. Compared with the pollution levels and carcinogenic potential risks reported in other studies, the soil PAH concentrations in the study area were in the low to intermediate range. A positive matrix factorization model indicates that coal/biomass combustion, coal and oil combustion, and coke ovens are the primary PAH sources, accounting for 33 percent, 26 percent, and 24 percent of total PAHs, respectively. The benzo[a]pyrene equivalent (BaPeq) concentrations had a range of n.d. to 476ngg(-1) for PAH7c, with a mean value of 34ngg(-1). The BaPeq concentrations of PAH7c accounted for more than 99 percent of the ∑PAH16, which suggests that seven PAHs were major carcinogenic contributors of ∑PAH16. According to the Canadian Soil Quality Guidelines, only six of the soil samples had concentrations above the safe BaPeq value of 600ngg(-1); the elevated concentrations observed at these sites can be attributed to coal combustion and industrial activities. Exposure to these soils through direct contact probably poses a significant risk to human health as a result of the carcinogenic effects of PAHs.

  2. Discrimination between induced, triggered, and natural earthquakes close to hydrocarbon reservoirs: A probabilistic approach based on the modeling of depletion-induced stress changes and seismological source parameters

    NASA Astrophysics Data System (ADS)

    Dahm, Torsten; Cesca, Simone; Hainzl, Sebastian; Braun, Thomas; Krüger, Frank

    2015-04-01

    Earthquakes occurring close to hydrocarbon fields under production are often under critical view of being induced or triggered. However, clear and testable rules to discriminate the different events have rarely been developed and tested. The unresolved scientific problem may lead to lengthy public disputes with unpredictable impact on the local acceptance of the exploitation and field operations. We propose a quantitative approach to discriminate induced, triggered, and natural earthquakes, which is based on testable input parameters. Maxima of occurrence probabilities are compared for the cases under question, and a single probability of being triggered or induced is reported. The uncertainties of earthquake location and other input parameters are considered in terms of the integration over probability density functions. The probability that events have been human triggered/induced is derived from the modeling of Coulomb stress changes and a rate and state-dependent seismicity model. In our case a 3-D boundary element method has been adapted for the nuclei of strain approach to estimate the stress changes outside the reservoir, which are related to pore pressure changes in the field formation. The predicted rate of natural earthquakes is either derived from the background seismicity or, in case of rare events, from an estimate of the tectonic stress rate. Instrumentally derived seismological information on the event location, source mechanism, and the size of the rupture plane is of advantage for the method. If the rupture plane has been estimated, the discrimination between induced or only triggered events is theoretically possible if probability functions are convolved with a rupture fault filter. We apply the approach to three recent main shock events: (1) the Mw 4.3 Ekofisk 2001, North Sea, earthquake close to the Ekofisk oil field; (2) the Mw 4.4 Rotenburg 2004, Northern Germany, earthquake in the vicinity of the Söhlingen gas field; and (3) the Mw 6

  3. Occurrence, sources and health risk assessment of polycyclic aromatic hydrocarbons in urban (Pudong) and suburban soils from Shanghai in China.

    PubMed

    Wang, Xue-Tong; Chen, Lei; Wang, Xi-Kui; Lei, Bing-Li; Sun, Yan-Feng; Zhou, Jun; Wu, Ming-Hong

    2015-01-01

    A comprehensive investigation was conducted to the urban (Pudong) and suburban soils in Shanghai. A total of 154 soil samples were analyzed for 26 PAHs including highly carcinogenic dibenzopyrenes (DBPs). The total concentrations ranged from 25.8 to 7380 μg kg(-1) for Σ26PAHs and 18.8 to 6320 μg kg(-1) for 16 USEPA priority PAHs (Σ16PAHs), respectively. The BaP toxic equivalent (BaPeq) concentrations were between 6.41 and 2880 μg kg(-1) for Σ24PAHs, 1.11 and 620 μg kg(-1) for Σ16PAHs and 2.72 and 2250 μg kg(-1) for Σ4DBPs. The high PAH contamination in green land soils might originate mainly from local road traffic and industrial activities, and sewage sludge application or waste water irrigation for soil. Seven sources of soil PAHs in Shanghai were identified by positive matrix factorization (PMF) model. The mean risk quotient (m-RQ) values indicated that there were medium to high ecological risks in 9.10% of soil samples, pyrene (Pyr), benzo[b]fluoranthene (BbF) and benz[a]anthracene (BaA) were the major ecological risk drivers under agricultural use. The cancer risk (CR) values were within the acceptable range at 35.7%, 35.1% and 31.2% of sampling sites for children, youths and adults, respectively. The total lifetime carcinogenic risk (TLCR) values at 57.8% of sampling sites were within the acceptable range. Overall, cancer risks of soil PAHs in all sampling sites in the studied area were below the highest acceptable risk, suggesting that soil PAHs are unlikely to pose a significant cancer risk for population based on ingestion, dermal contact and inhalation exposure pathways.

  4. Apparatus for hydrocarbon extraction

    DOEpatents

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  5. Dynamic Allocation of Sugars in Barley

    NASA Astrophysics Data System (ADS)

    Cumberbatch, L. C.; Crowell, A. S.; Fallin, B. A.; Howell, C. R.; Reid, C. D.; Weisenberger, A. G.; Lee, S. J.; McKisson, J. E.

    2014-03-01

    Allocation of carbon and nitrogen is a key factor for plant productivity. Measurements are carried out by tracing 11C-tagged sugars using positron emission tomography and coincidence counting. We study the mechanisms of carbon allocation and transport from carbohydrate sources (leaves) to sinks (stem, shoot, roots) under various environmental conditions such as soil nutrient levels and atmospheric CO2 concentration. The data are analyzed using a transfer function analysis technique to model transport and allocation in barley plants. The experimental technique will be described and preliminary results presented. This work was supported in part by USDOE Grant No. DE-FG02-97-ER41033 and DE-SC0005057.

  6. Concentration profiles, source apportionment and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in dumpsite soils from Agbogbloshie e-waste dismantling site, Accra, Ghana.

    PubMed

    Daso, Adegbenro P; Akortia, Eric; Okonkwo, Jonathan O

    2016-06-01

    The concentrations of eighteen (18) polycyclic aromatic hydrocarbons (PAHs), including the 16 USEPA's priority PAHs as well as two alkyl-substituted naphthalenes were determined in dumpsite soils collected from different sampling sites within the Agbogbloshie e-waste dismantling site in Accra, Ghana. Following their isolation with ultrasonic-assisted extraction technique, the concentrations of the PAHs were determined by gas chromatography mass spectrometry (GC-MS). Loss-on-ignition (LOI) method was employed for the determination of total organic carbon (TOC) of the soil samples. The mean Σ18PAHs obtained were 3006, 5627, 3046, 5555, and 7199 ng g(-1) dry weight (dw) for sampling sites A (mosque), B (dismantling site), C (residential house/police station), D (personal computer repairers' shop) and E (e-waste open burning area), respectively. In all cases, the prevalence of phenanthrene, fluoranthene and pyrene was generally observed across the sampling sites. In this study, PAHs with two to three rings and four to six rings exhibited strong positive correlations, whereas BbF and BkF showed weak positive and negative correlations with other PAHs investigated. With the exception of BbF and BkF, all the PAHs had moderate to strong positive correlations with the TOC. Benzo[a]pyrene equivalent (BaPeq) concentration is a useful indicator of the carcinogenic potency of environmental matrices and these ranged between 111 and 454 ng g(-1), which are generally below the 'safe' level of 600 ng g(-1) established for the protection of the environment and human health. Interestingly, the seven carcinogenic PAHs were the major contributors to the BaPeq concentrations accounting between 97.7 and 98.3 %. Despite the minimal risk to cancer via exposure to the investigated dumpsite soil as indicated in the present study, the prolonged exposure to these pollutants via various exposure pathways may result in increased risk to cancer over time. The application of several

  7. Oxygenated, nitrated, methyl and parent polycyclic aromatic hydrocarbons in rivers of Haihe River System, China: occurrence, possible formation, and source and fate in a water-shortage area.

    PubMed

    Qiao, Meng; Qi, Weixiao; Liu, Huijuan; Qu, Jiuhui

    2014-05-15

    Substituted polycyclic aromatic hydrocarbons (SPAHs) occur ubiquitously in the whole global environment as a result of their persistence and widely-spread sources. Some SPAHs show higher toxicities and levels than the corresponding PAHs. Three types of most frequently existing SPAHs, oxygenated-PAHs (OPAHs), nitrated-PAHs (NPAHs), and methyl-PAHs (MPAHs), as well as the 16 priority PAHs were investigated in this study. The purpose was to identify the occurrence, possible transformation, and source and fate of these target compounds in a water shortage area of North China. We took a river system in the water-shortage area in China, the Haihe River System (HRS), as a typical case. The rivers are used for irrigating the farmland in the North of China, which probably introduce these pollutants to the farmland of this area. The MPAHs (0.02-0.40 μg/L in dissolved phase; 0.32-16.54 μg/g in particulate phase), OPAHs (0.06-0.19 μg/L; 0.41-17.98 μg/g), and PAHs (0.16-1.20 μg/L; 1.56-79.38 μg/g) were found in the water samples, but no NPAHs were detected. The concentrations of OPAHs were higher than that of the corresponding PAHs. Seasonal comparison results indicated that the OPAHs, such as anthraquinone and 2-methylanthraquinone, were possibly transformed from the PAHs, particularly at higher temperature. Wastewater treatment plant (WWTP) effluent was deemed to be the major source for the MPAHs (contributing 62.3% and 87.6% to the receiving river in the two seasons), PAHs (68.5% and 89.4%), and especially OPAHs (80.3% and 93.2%) in the rivers. Additionally, the majority of MPAHs (12.4 kg, 80.0% of the total input), OPAHs (16.2 kg, 83.5%), and PAHs (65.9 kg, 93.3%) in the studied months entered the farmland through irrigation.

  8. Direct hydrocarbon fuel cells

    DOEpatents

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  9. Human Health and Ecological Risk Assessment of 16 Polycyclic Aromatic Hydrocarbons in Drinking Source Water from a Large Mixed-Use Reservoir.

    PubMed

    Sun, Caiyun; Zhang, Jiquan; Ma, Qiyun; Chen, Yanan

    2015-10-30

    Reservoirs play an important role in living water supply and irrigation of farmlands, thus the water quality is closely related to public health. However, studies regarding human health and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the waters of reservoirs are very few. In this study, Shitou Koumen Reservoir which supplies drinking water to 8 million people was investigated. Sixteen priority PAHs were analyzed in a total of 12 water samples. In terms of the individual PAHs, the average concentration of Fla, which was 5.66 × 10(-1) μg/L, was the highest, while dibenz(a,h)anthracene which was undetected in any of the water samples was the lowest. Among three PAH compositional patterns, the concentration of low-molecular-weight and 4-ring PAHs was dominant, accounting for 94%, and the concentration of the total of 16 PAHs was elevated in constructed-wetland and fish-farming areas. According to the calculated risk quotients, little or no adverse effects were posed by individual and complex PAHs in the water on the aquatic ecosystem. In addition, the results of hazard quotients for non-carcinogenic risk also showed little or no negative impacts on the health of local residents. However, it could be concluded from the carcinogenic risk results that chrysene and complex PAHs in water might pose a potential carcinogenic risk to local residents. Moreover, the possible sources of PAHs were identified as oil spills and vehicular emissions, as well as the burning of biomass and coal.

  10. Human Health and Ecological Risk Assessment of 16 Polycyclic Aromatic Hydrocarbons in Drinking Source Water from a Large Mixed-Use Reservoir

    PubMed Central

    Sun, Caiyun; Zhang, Jiquan; Ma, Qiyun; Chen, Yanan

    2015-01-01

    Reservoirs play an important role in living water supply and irrigation of farmlands, thus the water quality is closely related to public health. However, studies regarding human health and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the waters of reservoirs are very few. In this study, Shitou Koumen Reservoir which supplies drinking water to 8 million people was investigated. Sixteen priority PAHs were analyzed in a total of 12 water samples. In terms of the individual PAHs, the average concentration of Fla, which was 5.66 × 10−1 μg/L, was the highest, while dibenz(a,h)anthracene which was undetected in any of the water samples was the lowest. Among three PAH compositional patterns, the concentration of low-molecular-weight and 4-ring PAHs was dominant, accounting for 94%, and the concentration of the total of 16 PAHs was elevated in constructed-wetland and fish-farming areas. According to the calculated risk quotients, little or no adverse effects were posed by individual and complex PAHs in the water on the aquatic ecosystem. In addition, the results of hazard quotients for non-carcinogenic risk also showed little or no negative impacts on the health of local residents. However, it could be concluded from the carcinogenic risk results that chrysene and complex PAHs in water might pose a potential carcinogenic risk to local residents. Moreover, the possible sources of PAHs were identified as oil spills and vehicular emissions, as well as the burning of biomass and coal. PMID:26529001

  11. HZSM-5/MCM-41 composite molecular sieves for the catalytic cracking of endothermic hydrocarbon fuels: nano-ZSM-5 zeolites as the source

    NASA Astrophysics Data System (ADS)

    Sang, Yu; Jiao, Qingze; Li, Hansheng; Wu, Qin; Zhao, Yun; Sun, Kening

    2014-12-01

    A series of HZSM-5/MCM-41 composite molecular sieves (HZM-Ns ( x)) were prepared by employing nano-ZSM-5 zeolites with the SiO2/Al2O3 ratios ( x) of 50, 100 and 150 as the source. These materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, N2 adsorption-desorption measurement, and NH3 temperature-programmed desorption. The catalytic cracking of endothermic hydrocarbon fuels over the HZM-Ns with n-decane as model was evaluated at atmospheric pressure and 500 °C. The effect of the parent zeolite, mesopore and SiO2/Al2O3 ratio on the structure, acidity, and catalytic performance of HZM-Ns was investigated. The HZM-Ns exhibited a skeletal matrix with nano-sized HZSM-5 particles (200-300 nm) with a controllable acidity well dispersed in and microporous-mesoporous hierarchical pores. The mesoporous structure improved the diffusion of the reactants and products in the pores, and the HZSM-5 nanoparticles uniformly dispersed in the MCM-41 matrix supplied a proper acidity, shorter channels, and a higher specific surface area for reaction. These resulted in a high catalytic activity, a high selectivity to light olefins and a long lifetime for n-decane catalytic cracking. The HZM-N (150) exhibited the excellent conversion, a high selectivity to light olefins and a long lifetime due to low diffusion resistance, high specific surface area, and appropriate acid distribution and strength, with the increasing SiO2/Al2O3 ratio.

  12. Discrimination between induced, triggered and natural earthquakes close to hydrocarbon reservoirs: A probabilistic approach based on the modeling of depletion-induced stress changes and seismological source parameters

    NASA Astrophysics Data System (ADS)

    Dahm, T.; Cesca, S.; Hainzl, S.; Krueger, F.

    2011-12-01

    Earthquakes occurring close to hydrocarbon fields under production are often under critical view of being induced or triggered. However, clear and testable rules to discriminate the different events have rarely been developed and tested. The unresolved scientific problem may lead to lengthy public disputes with unpredictable impact on the local acceptance of the exploitation and field operations. We propose a quantitative approach to discriminate induced, triggered and natural earthquakes, which is based on testable input parameters. Maxima of occurrence probability distributions (PdF) are compared for the cases under question, and a single probability of being induced is reported. The uncertainties of earthquake location and seismicity rate is considered in terms of joint probabilities. The PdF of induced events is derived from the modeling of Coulomb stress changes and a rate and state dependent seismicity model. In our case a 3D boundary element method has been modified to estimate the stress changes outside the reservoir, which are related to pore pressure changes in the field formation. The predicted rate of natural earthquakes is either derived from the background seismicity or, in case of rare events, from an estimate of the tectonic loading. Instrumentally derived, seismological information on the event location, source mechanism and the size of the rupture plane is of advantage for the method. If the rupture plane has been estimated, the discrimination between induced or only triggered events is theoretically possible if joint PdF's are integrated over the rupture plane. We apply the approach to two recent events: (1) the Mw 4.3 Ekofisk 2002, North Sea earthquake close to the Ekofisk oil field, and the 2004 Mw 4.4 Rotenburg, Northern Germany earthquake in the vicinity of the Soehlingen gas field. While one event was clearly triggered and induced, the other is possibly only triggered.

  13. Polycyclic aromatic hydrocarbons and organochlorine pesticides in rice hull from a typical e-waste recycling area in southeast China: temporal trend, source, and exposure assessment.

    PubMed

    Liu, Fang; Liao, Chunyang; Fu, Jianjie; Lv, Jungang; Xue, Qinzhao; Jiang, Guibin

    2014-02-01

    The residue levels of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and 16 selected organochlorine pesticides (OCPs) in rice and rice hull collected from a typical e-waste recycling area in southeast China were investigated from 2005 to 2007. PAHs and OCPs also were measured in ten mollusk species (soft tissues) collected in an adjacent bay in 2007. Individual PAHs were frequently found in the entire sample set (including the rice, hull, and mollusk samples) with a detection rate of 73 %. The total concentrations of 16 PAHs (ΣPAHs) and 16 OCPs (ΣOCPs) were in the range of 40.8-432 ng/g dry weight (mean: 171 ng/g) and 2.35-925 ng/g (122 ng/g), respectively, which were comparable or higher than those reported in some polluted areas. Statistical comparisons suggested that the concentrations of contaminants in hull gradually decreased from 2005 to 2007 and the residue levels were generally in the order of mollusk, hull, and rice, on a dry weight basis. Principal component analysis in combination with diagnostic ratios implied that combustion of coal, wood, and plastic wastes that are closely associated with crude e-waste recycling activities is the main source of PAHs. The finding of decreasing trend of concentrations of PAHs in this area is consistent with the efforts of local authorities to strengthen regulations on illegal e-waste recycling activities. Composition analysis suggested that there is a recent usage or discharge of hexachlorocyclohexane and dichlorodiphenyltrichloroethane into the tested area. The estimated daily intake (EDI) of ΣPAHs and ΣOCPs (calculated from mean concentrations) through rice and mollusk consumption was 0.411 and 0.921 μg/kg body weight (bw)/day, respectively.

  14. Airborne particulate polycyclic aromatic hydrocarbon (PAH) pollution in a background site in the North China Plain: concentration, size distribution, toxicity and sources.

    PubMed

    Zhu, Yanhong; Yang, Lingxiao; Yuan, Qi; Yan, Chao; Dong, Can; Meng, Chuanping; Sui, Xiao; Yao, Lan; Yang, Fei; Lu, Yaling; Wang, Wenxing

    2014-01-01

    The size-fractionated characteristics of particulate polycyclic aromatic hydrocarbons (PAHs) were studied from January 2011 to October 2011 using a Micro-orifice Uniform Deposit Impactor (MOUDI) at the Yellow River Delta National Nature Reserve (YRDNNR), a background site located in the North China Plain. The average annual concentration of total PAHs in the YRDNNR (18.95 ± 16.51 ng/m(3)) was lower than that in the urban areas of China; however, it was much higher than that in other rural or remote sites in developed countries. The dominant PAHs, which were found in each season, were fluorene (5.93%-26.80%), phenanthrene (8.17%-26.52%), fluoranthene (15.23%-27.12%) and pyrene (9.23%-16.31%). A bimodal distribution was found for 3-ring PAHs with peaks at approximately 1.0-1.8 μm and 3.2-5.6 μm; however, 4-6 ring PAHs followed a nearly unimodal distribution, with the highest peak in the 1.0-1.8 μm range. The mass median diameter (MMD) values for the total PAHs averaged 1.404, 1.467, 1.218 and 0.931 μm in spring, summer, autumn and winter, respectively. The toxicity analysis indicated that the carcinogenic potency of particulate PAHs existed primarily in the <1.8 μm size range. Diagnostic ratios and PCA analysis indicated that the PAHs in aerosol particles were mainly derived from coal combustion. In addition, back-trajectory calculations demonstrated that atmospheric PAHs were produced primarily by local anthropogenic sources.

  15. Sources appointment and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in sediments of Erhai Lake, a low-latitude and high-altitude lake in southwest China.

    PubMed

    Hezhong, Yuan; Enlou, Zhang; Qi, Lin; Rong, Wang; Enfeng, Liu

    2016-03-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) were analyzed from the surficial sediments in Erhai Lake, a plateau lake in China. The results showed that except for acenaphthylene (Ace) Ace and Dibenz(a,h)anthracene (DBA), the central region contained individual PAHs at concentrations lower than those in other lake regions. Total concentration of the PAHs (ΣPAHs) in the sediments from Erhai Lake ranged from 32.42 to 558.53 mg/kg with a mean value of 256.70 mg/kg. The maximum value of ΣPAHs was observed in the north region of the lake and more than 10-fold higher than the minimum values. Moreover, high molecular weight (HMW) PAHs, especially 5-ring PAHs, accounted for higher ratios up to 76 % relative to other PAHs compound in almost all sampling sites. Molecular diagnostic ratios including anthtacene (Ant)/(Ant + phenanthrene (Phe)), fluoranthene (Flt)/(Flt + pyrene (Pyr)), benz(a)anthracene (BaA)/(BaA + chrysene (Chr)), and indeno(1,2,3-cd)pyrene (IPY)/(IPY + benz(g,h,i)perylene (BPE)) were recorded at all sampling sites and indicated that the origin of PAHs in Erhai Lake was predominately pyrolytic. Furthermore, principal component analysis with component dominating by HMW PAHs showed that combustion origins were the primary contamination sources of PAHs in the sediments of Erhai Lake. Finally, ecological risk assessment indicated that the sediments from Erhai Lake are exposed to potential low risk for ΣPAHs, and the ecological risk decreases in the order of northern region > southern region > central region.

  16. Optrode for sensing hydrocarbons

    DOEpatents

    Miller, Holly; Milanovich, Fred P.; Hirschfeld, Tomas B.; Miller, Fred S.

    1988-01-01

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons.

  17. Optrode for sensing hydrocarbons

    DOEpatents

    Miller, Holly; Milanovich, Fred P.; Hirschfeld, Tomas B.; Miller, Fred S.

    1987-01-01

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons.

  18. Optrode for sensing hydrocarbons

    DOEpatents

    Miller, H.; Milanovich, F.P.; Hirschfeld, T.B.; Miller, F.S.

    1987-05-19

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons. 6 figs.

  19. Optrode for sensing hydrocarbons

    DOEpatents

    Miller, H.; Milanovich, F.P.; Hirschfeld, T.B.; Miller, F.S.

    1988-09-13

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons. 5 figs.

  20. Channel Allocation Options.

    ERIC Educational Resources Information Center

    Powers, Robert S.

    The Frequency Allocation Subcommittee of the Coordinating Committee for Cable Communication Systems, Institute of Electrical and Electronic Engineers, was formed to produce a background report on the general problems of frequency allocation and assignments in cable television. The present paper, based on the subcommittee's interim report,…

  1. Carbon allocation and accumulation in conifers

    SciTech Connect

    Gower, S.T.; Isebrands, J.G.; Sheriff, D.W.

    1995-07-01

    Forests cover approximately 33% of the land surface of the earth, yet they are responsible for 65% of the annual carbon (C) accumulated by all terrestrial biomes. In general, total C content and net primary production rates are greater for forests than for other biomes, but C budgets differ greatly among forests. Despite several decades of research on forest C budgets, there is still an incomplete understanding of the factors controlling C allocation. Yet, if we are to understand how changing global events such as land use, climate change, atmospheric N deposition, ozone, and elevated atmospheric CO{sub 2} affect the global C budget, a mechanistic understanding of C assimilation, partitioning, and allocation is necessary. The objective of this chapter is to review the major factors that influence C allocation and accumulation in conifer trees and forests. In keeping with the theme of this book, we will focus primarily on evergreen conifers. However, even among evergreen conifers, leaf, canopy, and stand-level C and nutrient allocation patterns differ, often as a function of leaf development and longevity. The terminology related to C allocation literature is often inconsistent, confusing and inadequate for understanding and integrating past and current research. For example, terms often used synonymously to describe C flow or movement include translocation, transport, distribution, allocation, partitioning, apportionment, and biomass allocation. A common terminology is needed because different terms have different meanings to readers. In this paper we use C allocation, partitioning, and accumulation according to the definitions of Dickson and Isebrands (1993). Partitioning is the process of C flow into and among different chemical, storage, and transport pools. Allocation is the distribution of C to different plant parts within the plant (i.e., source to sink). Accumulation is the end product of the process of C allocation.

  2. Biological sources for phenylalkane hydrocarbons

    SciTech Connect

    Ellis, L.; Winans, R.E.; Langworthy, T.A.

    1996-08-01

    Linear alkylbenzenes (phenylalkanes) represent an important class of molecular compounds used widely in today`s society as building blocks for detergent manufacture. Evidence is presented to support the proposition in that phenylalkanes in some Australian crude oils and sediments are of geochemical origin rather than resulting from contamination from byproducts of the petrochemical synthesis of surfactants. Evidence presented shows: (1) an unexposed sediment core was found to contain phenylalkanes; (2) the molecular weight range of phenylalkanes in sediments and crude oils is usually wider than that found in surfactants, extending in some cases beyond C{sub 35}; and (3) phenylalkanes were found in the neutral lipid extract of extant {ital Thermoplasma} bacteria. {ital Thermoplasma acidophilum} is an obligate acidiphilic (pH 2) and thermophilic (60{degrees}C), cell wall-less archaeobacterium originally isolated from self-heating coal refuse piles enriched in pyritic materials.

  3. An evaluation of petrogenic hydrocarbons in northern Gulf of Alaska continental shelf sediments - The role of coastal oil seep inputs

    USGS Publications Warehouse

    Short, J.W.; Kolak, J.J.; Payne, J.R.; Van Kooten, G. K.

    2007-01-01

    the Yakutat terrane. We therefore conclude that previous investigations relying on source allocation models have considerably overestimated oil seeps as a hydrocarbon source to the Gulf of Alaska. ?? 2006 Elsevier Ltd. All rights reserved.

  4. 26 CFR 1.904(g)-3T - Ordering rules for the allocation of net operating losses, net capital losses, U.S. source losses...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...(g)-3T Section 1.904(g)-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Income from Sources Without the United States § 1.904(g)-3T.... The rules must be applied in the order set forth in paragraphs (b) through (g) of this section....

  5. 26 CFR 1.904(g)-3 - Ordering rules for the allocation of net operating losses, net capital losses, U.S. source losses...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of separate limitation losses, overall foreign losses, and overall domestic losses. 1.904(g)-3 Section 1.904(g)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Income from Sources Without the United States § 1.904(g)-3...

  6. PM10-bound polycyclic aromatic hydrocarbons in Chiang Mai (Thailand): Seasonal variations, source identification, health risk assessment and their relationship to air-mass movement

    NASA Astrophysics Data System (ADS)

    Wiriya, Wan; Prapamontol, Tippawan; Chantara, Somporn

    2013-04-01

    This study aims to analyze the seasonal variations of PM10-bound polycyclic aromatic hydrocarbons (PAHs) for an estimation of the human health risk and identification of their possible sources. Ninety four PM10 samples were collected during the dry and wet seasons of 2010 and the dry season of 2011 in Chiang Mai, Thailand, and analyzed for 16 PAHs by gas chromatography-mass spectrometry. The average PM10 concentrations were 104.91 ± 32.70, 13.28 ± 11.34 and 36.24 ± 19.16 μg/m3 in dry season of 2010, wet season of 2010 and dry season of 2011, respectively, while the average 16-PAHs concentrations were 25.87 ± 10.13, 3.12 ± 2.18 and 4.58 ± 2.18 ng/m3, respectively. Correlations of PM10 and total PAHs concentrations were relatively high during all seasons (r > 0.796). In addition, PM10 concentrations were highly correlated with carcinogenic PAHs (r = 0.927) during the dry season of 2010, indicating that carcinogenic compounds were dominant in the particulate PAHs and could be generated from open burning, usually conducted in the dry season. The average PM10 concentration in the dry season of 2011 was much lower than that in 2010 and lower than the annual average of the past 12 years (48.17 μg/m3) because of the unusually high amount of rain precipitation and low open burning activity in this year. According to the accumulated number of hot spots occurring in northern part of Thailand, approximately 19,000 spots were found in the dry season of 2010, while only 6,600 spots were found in the dry season of 2011. It can be seen that larger scale open burning activities were performed in the dry season of 2010 than in the dry season of 2011. The value of toxicity equivalent concentration from PAHs in the dry season of 2010 was higher than that of the wet season of 2010 and the dry season of 2011. This is obviously related to concentrations of PM10 and PAHs. Diagnostic ratio and principal component analysis were used to find out the sources of PM10-bound PAHs. It was

  7. Ustilago maydis Infection Strongly Alters Organic Nitrogen Allocation in Maize and Stimulates Productivity of Systemic Source Leaves1[W][OA

    PubMed Central

    Horst, Robin J.; Doehlemann, Gunther; Wahl, Ramon; Hofmann, Jörg; Schmiedl, Alfred; Kahmann, Regine; Kämper, Jörg; Sonnewald, Uwe; Voll, Lars M.

    2010-01-01

    The basidiomycete Ustilago maydis is the causal agent of corn smut disease and induces tumor formation during biotrophic growth in its host maize (Zea mays). We have conducted a combined metabolome and transcriptome survey of infected leaves between 1 d post infection (dpi) and 8 dpi, representing infected leaf primordia and fully developed tumors, respectively. At 4 and 8 dpi, we observed a substantial increase in contents of the nitrogen-rich amino acids glutamine and asparagine, while the activities of enzymes involved in primary nitrogen assimilation and the content of ammonia and nitrate were reduced by 50% in tumors compared with mock controls. Employing stable isotope labeling, we could demonstrate that U. maydis-induced tumors show a reduced assimilation of soil-derived 15NO3− and represent strong sinks for nitrogen. Specific labeling of the free amino acid pool of systemic source leaves with [15N]urea revealed an increased import of organic nitrogen from systemic leaves to tumor tissue, indicating that organic nitrogen provision supports the formation of U. maydis-induced tumors. In turn, amino acid export from systemic source leaves was doubled in infected plants. The analysis of the phloem amino acid pool revealed that glutamine and asparagine are not transported to the tumor tissue, although these two amino acids were found to accumulate within the tumor. Photosynthesis was increased and senescence was delayed in systemic source leaves upon tumor development on infected plants, indicating that the elevated sink demand for nitrogen could determine photosynthetic rates in source leaves. PMID:19923237

  8. Hydrocarbon bioremediation -- An overview

    SciTech Connect

    Reisinger, H.J.

    1995-12-31

    Bioremediation is the process that transforms xenobiotics introduced into the environment to a less toxic or innocuous form, or mineralizes them to inorganic species. The processes can be carried out through either aerobic or anaerobic pathways by indigenous heterotrophs or by specially engineered organisms. For some xenobiotics, the process can also be carried out by cometabolic processes, which use another compound as the carbon and energy source. This technique can be applied either in situ or ex situ. An overview is presented of real-world applications of a variety of hydrocarbon bioremediation approaches, including biopiling, bioventing, bioslurping, landfarming, electrobioreclamation, and biovertical circulation wells. Problems in translating laboratory and field-scale pilot test data to full-scale operating systems are discussed. Such issues include biodegradation enhancement, nutrient and electron acceptor delivery, alternative electron acceptors, and integration of biological, chemical, and physical approaches to hydrocarbon remediation.

  9. Pore-space alteration in source rock (shales) during hydrocarbons generation: X-ray microtomography and pore-scale modelling study

    NASA Astrophysics Data System (ADS)

    Korost, Dmitry; Gerke, Kirill; Akhmanov, Grigory; Vasilyev, Roman; Čapek, Pavel; Karsanina, Marina; Nadezhkin, Dmitry

    2013-04-01

    Hydrocarbons (HC) are generated from solid organic matter (kerogen) due to thermocatalytic reactions. The rate of such reactions shows direct correlation with temperature and depends on the depth of source rock burial. Burial of sedimentary rock is also inevitably accompanied by its structural alteration owing to compaction, dehydration and re-crystallization. Processes of HC generation, primary migration and structural changes are inaccessible for direct observation in nature, but they can be studied in laboratory experiments. Modern technical facilities of laboratories make it possible to carry out experiments on HC generation from the organic-rich rocks at a completely new level (Kobchenko et al., 2011). Some new technologies, including X-ray microtomography and pore-scale modeling, allow us to carry out a step-by-step description of such processes and their development, and to study their reflection in alterations of rock structure. Experiments were carried out with a clayey-carbonate rock sample of the Domanic Formaition taken at a depth of 1939 m from borehole drilled in the central part of the Melekes depression (West Tatar arch, Russia). The rock chosen fits the very essential requirements for studying HC generation under laboratory conditions - high organic matter content and its low metamorphic grade. Our work aimed such a study in an undisturbed rock sample by heating it in nitrogen atmosphere based on a specified temperature regime in a RockEval6 analyzer and monitoring alterations in the pore space structure. Observations were carried out with a SkyScan-1172 X-ray microtomography scanner (resulting scan resolution of 1 µm). A cylinder, 4 mm in diameter, was prepared from the rock sample for the pyrolitic and microtomographic analyses. Scanning procedures were carried out in 5 runs. Temperature interval for each run had to match the most important stage of HC generation in the source rock, namely: (1) original structure; (2) 100-300

  10. [Contamination levels and source analysis of polycyclic aromatic hydrocarbons and organochlorine pesticides in soils and grasses from lake catchments in the Tibetan Plateau].

    PubMed

    Xie, Ting; Zhang, Shu-Juan; Yang, Rui-Qiang

    2014-07-01

    Soils and grasses samples were collected from 6 typical lake catchments in the central and northern Tibetan Plateau (TP) in August 2007 and analyzed for polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs, including HCHs and DDTs). The concentrations of sigma16 PAHs, sigma HCHs and sigma DDTs in soil samples were in the range of 60.6-614 ng x g(-1) (mean 194 ng x g(-1)), 0.06-0.74 ng x g(-1) (mean 0.31 ng x g(-1)) and N. D. -0.17 ng x g(-1) (mean 0.07 ng x g(-1)) while those of sigma15 PAHs (excluding NAP), sigma HCHs and sigma DDTs in grasses were in the range of 262-519 ng x g(-1) (mean 327 ng x g(-1)), 0.55-3.92 ng x g(-1) (mean 2.17 ng x g(-1)) and 0.20-2.19 ng x g(-1) (mean 0.92 ng x g(-1)), respectively. All compounds were significantly lower than those in European high mountains. The biological concentration effect of grasses to soils was notable with the values of BCF ranging from 4.2 to 19.3. No significant correlations were observed between the concentrations of POPs and the content of OM/lipid, or the altitude of the sampling sites. The PAHs profile was dominated by lighter constituents (2 & 3-ring PAHs accounted for higher than 80%). The special diagnostic ratios of PAHs suggested that PAHs in the TP were mainly produced by low-temperature combustion of biomass and fossil fuels, and the relatively low ratios of alpha/gamma-HCH and high ratios of o,p'-DDT/p,p'-DDT implied that the wide applications of lindane and dicofol contributed to the OCPs contamination in the TP. According to the backward airmass trajectory models, it was deduced that the westerly wind was the main source for both central and northern sites in the TP during winter. During summer, pollutants in the central sites of the TP were mainly from the Indian subcontinent while the northern sites were also affected by Chinese inland provinces.

  11. CORONA-INDUCED PHOTOXIDATION OF ALCOHOLS AND HYDROCARBONS OVER TIO2 IN THE ABSENCE OF A UV LIGHT SOURCE - A NOVEL AND ENVIRONMENTALLY FRIENDLY METHOD FOR OXIDATION

    EPA Science Inventory

    Corona-induced photooxidation is a novel oxidation methodology for the efficient oxidation of alcohols and hydrocarbons utilizing the advantage of both the high oxidizing power of ozone formed in the reactor as well as the photooxidation capability of the UV light generated durin...

  12. On-site analysis of d13C- and dD-CH4 by laser spectroscopy for the allocation of source processes

    NASA Astrophysics Data System (ADS)

    Eyer, Simon; Tuzson, Béla; Popa, Elena; van der Veen, Carina; Röckmann, Thomas; Brand, Willi A.; Fisher, Rebecca; Lowry, David; Nisbet, Euan G.; Brennwald, Matthias S.; Harris, Eliza; Emmenegger, Lukas; Fischer, Hubertus; Mohn, Joachim

    2015-04-01

    Analysis of the most abundant methane isotopologues 12CH4, 13CH4 and 12CH3D can be used to disentangle source/sink processes (Fischer et al. 2008) and to develop target oriented reduction strategies. Isotopic analysis of CH4 is accomplished by isotope-ratio mass-spectrometry (IRMS) and more recently by mid-infrared laser spectroscopy. For high precision measurements in ambient air, however, both techniques rely on preconcentration of the target gas (Eyer et al. 2014). We developed a field-deployable analyser for real-time, on-site analysis of CH4 isotopologues which is based on a dual quantum cascade laser absorption spectrometer (QCLAS) in combination with an innovative preconcentration technique named trace gas extractor (TREX). The core part of the 19 ″ rack-mounted preconcentration unit is a highly efficient adsorbent trap attached to the cold end of a Stirling cooler. The system achieves preconcentration factors >500. For fast desorption and optimal heat management, the trap is decoupled from the cooler during desorption. The QCLAS has been developed based on a previously described instrument (Tuzson 2010). It comprises two cw-QC laser sources combined and coupled into an astigmatic multipass absorption cell with 76 m optical path. The developed technique reaches an unsurpassed precision of 0.1‰ for d13C-CH4 and <0.5‰ for dD-CH4 at 600 s spectral averaging. The potential of the new analytical system for field applications has been shown in June 2014, where the system has achieved an overall repeatability of 0.19‰ for d13C and 1.7‰ for dD-CH4 for repeated target gas measurements. Compatibility of TREX - QCLAS with flask sampling - IRMS for analysis of ambient CH4 fulfilled the extended WMO/GAW compatibility goals of 0.2‰ for d13C-CH4 and 5‰ for dD-CH4. References: Fischer, H., Behrens, M., Bock, M., Richter, U., Schmitt, J., Loulergue, L., Chappellaz, J., Spahni, R., Blunier, T., Leuenberger, M., Stocker, T. F. (2008) Nature 452: 864-867. Eyer, S

  13. Nox reduction system utilizing pulsed hydrocarbon injection

    DOEpatents

    Brusasco, Raymond M.; Penetrante, Bernardino M.; Vogtlin, George E.; Merritt, Bernard T.

    2001-01-01

    Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

  14. GENERATING SOPHISTICATED SPATIAL SURROGATES USING THE MIMS SPATIAL ALLOCATOR

    EPA Science Inventory

    The Multimedia Integrated Modeling System (MIMS) Spatial Allocator is open-source software for generating spatial surrogates for emissions modeling, changing the map projection of Shapefiles, and performing other types of spatial allocation that does not require the use of a comm...

  15. Approaches to Resource Allocation

    ERIC Educational Resources Information Center

    Dressel, Paul; Simon, Lou Anna Kimsey

    1976-01-01

    Various budgeting patterns and strategies are currently in use, each with its own particular strengths and weaknesses. Neither cost-benefit analysis nor cost-effectiveness analysis offers any better solution to the allocation problem than do the unsupported contentions of departments or the historical unit costs. An operable model that performs…

  16. Production of hydrocarbons by Aspergillus carbonarius ITEM 5010.

    PubMed

    Sinha, Malavika; Sørensen, Annette; Ahamed, Aftab; Ahring, Birgitte Kiær

    2015-04-01

    The filamentous fungus, Asperigillus carbonarius, is able to produce a series of hydrocarbons in liquid culture using lignocellulosic biomasses, such as corn stover and switch grass as carbon source. The hydrocarbons produced by the fungus show similarity to jet fuel composition and might have industrial application. The production of hydrocarbons was found to be dependent on type of media used. Therefore, ten different carbon sources (oat meal, wheat bran, glucose, carboxymethyl cellulose, avicel, xylan, corn stover, switch grass, pretreated corn stover, and pretreated switch grass) were tested to identify the maximum number and quantity of hydrocarbons produced. Several hydrocarbons were produced include undecane, dodecane, tetradecane, hexadecane 2,4-dimethylhexane, 4-methylheptane, 3-methyl-1-butanol, ethyl benzene, o-xylene. Oatmeal was found to be the carbon source resulting in the largest amounts of hydrocarbon products. The production of fungal hydrocarbons, especially from lignocellulosic biomasses, holds a great potential for future biofuel production whenever our knowledge on regulators and pathways increases.

  17. Compatibility of Direct Sugar to Hydrocarbon (DSH-76) with Combined Contaminated Fuel Detector

    DTIC Science & Technology

    2013-05-31

    produced from the direct sugar to hydrocarbon (DSH) production process. Petroleum sourced F-76, alternative fuel source DSH-76 and 70/30 & 50/50...of the CCFD with the renewable aviation and marine diesel fuels. The Direct Sugar to Hydrocarbon (DSH) production pathway produces fuels made...from direct fermentation of sugar into olefinic hydrocarbons. The olefinic hydrocarbons are hydroprocessed to produce an iso-paraffinic hydrocarbon

  18. Hydrocarbons in soils: Origin, composition, and behavior (Review)

    NASA Astrophysics Data System (ADS)

    Gennadiev, A. N.; Pikovskii, Yu. I.; Tsibart, A. S.; Smirnova, M. A.

    2015-10-01

    It has been shown that a large body of evidence on the sources, transformation, and migration of hydrocarbons in soils has been acquired by different researchers. Available data about the origin and behavior of hydrocarbon gases, total petroleum hydrocarbons, polycyclic aromatic hydrocarbons, alkanes, and other compounds have been considered successively. A wide range of natural and anthropogenic factors affecting the transformation and migration of hydrocarbons in soils have been analyzed. The indicative value of these compounds has been explained. At the same time, many problems related to hydrocarbons in soils are still insufficiently understood. Sparse and fragmentary data are available in the literature on the interaction of different hydrocarbon groups in the soil. Few data refer to the features of hydrocarbons in background zonal soils; there are almost no interzonal comparisons. The behavior of hydrocarbons in soils of different landscape-geographical positions is characterized in isolated publications. The hydrocarbon status of soils as an integral complex of interrelated hydrocarbons is almost not analyzed. Hydrocarbons of a single class (polycyclic aromatic hydrocarbons, hydrocarbon gases, n-alkanes, etc.) are usually characterized in each publication.

  19. Constrained control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne C.

    1992-01-01

    This paper addresses the problem of the allocation of several flight controls to the generation of specified body-axis moments. The number of controls is greater than the number of moments being controlled, and the ranges of the controls are constrained to certain limits. The controls are assumed to be individually linear in their effect throughout their ranges of motion, and independent of one another in their effects. The geometries of the subset of the constrained controls and of its image in moment space are examined. A direct method of allocating these several controls is presented, that guarantees the maximum possible moment is generated within the constraints of the controls. The results are illustrated by an example problem involving three controls and two moments.

  20. Myrmics Memory Allocator

    SciTech Connect

    Lymperis, S.

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  1. Source identification of petroleum hydrocarbons in soil and sediments from Iguaçu River Watershed, Paraná, Brazil using the CHEMSIC method (CHEMometric analysis of Selected Ion Chromatograms).

    PubMed

    Gallotta, Fabiana D C; Christensen, Jan H

    2012-04-27

    A chemometric method based on principal component analysis (PCA) of pre-processed and combined sections of selected ion chromatograms (SICs) is used to characterise the hydrocarbon profiles in soil and sediment from Araucária, Guajuvira, General Lúcio and Balsa Nova Municipalities (Iguaçu River Watershed, Paraná, Brazil) and to indicate the main sources of hydrocarbon pollution. The study includes 38 SICs of polycyclic aromatic compounds (PACs) and four of petroleum biomarkers in two separate analyses. The most contaminated samples are inside the Presidente Getúlio Vargas Refinery area. These samples represent a petrogenic pattern and different weathering degrees. Samples from outside the refinery area are either less or not contaminated, or contain mixtures of diagenetic, pyrogenic and petrogenic inputs where different proportions predominate. The locations farthest away from industrial activity (Balsa Nova) contains the lowest levels of PAC contamination. There are no evidences to conclude positive matches between the samples from outside the refinery area and the Cusiana spilled oil.

  2. Determination of benzo[a]pyrene levels in ambient air and the source of polycyclic aromatic hydrocarbons using a diagnostic ratio method in Ghana.

    PubMed

    Bortey-Sam, Nesta; Akoto, Osei; Ikenaka, Yoshinori; Nakayama, Shouta M M; Ishizuka, Mayumi

    2013-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants produced from incomplete combustion of fuel or vegetation fires. Their presence in air deserves attention because they can produce carcinogenic and mutagenic effects. As an industrialized and economically significant city in Ghana, Kumasi has been subject to heavy anthropogenic influences due to rapid economic development and urbanization leading to a greater fuel combustion rate. Airborne particulate samples were collected on filters using a Sibata air sampler and analyzed by gas chromatography-mass spectrometry (GC-MS). Our results indicated that air from the city center can be classified as highly polluted with benzo[a] pyrene (B[a]P). The diagnostic ratios of the results showed that PAHs in the air samples were mainly from fuel combustion.

  3. Assessment of undiscovered hydrocarbon resources of sub-Saharan Africa

    USGS Publications Warehouse

    Brownfield, Michael E.

    2016-01-01

    The assessment was geology-based and used the total petroleum system (TPS) concept. The geologic elements of a TPS are hydrocarbon source rocks (source rock maturation and hydrocarbon generation and migration), reservoir rocks (quality and distribution), and traps where hydrocarbon accumulates. Using these geologic criteria, 16 conventional total petroleum systems and 18 assessment units in the 13 provinces were defined. The undiscovered, technically recoverable oil and gas resources were assessed for all assessment units.

  4. Liquid hydrocarbons probable under Ross Sea

    USGS Publications Warehouse

    Cooper, A. K.; Davey, F.J.; Hinz, K.

    1988-01-01

    Thick glacial strata, which have no source-rock potential, cover the Ross Sea. If these strata persist to great depths, then hydrocarbon-generation prospects will be poor. Deeply buried strata within Ross Sea rift-grabens, if like other Gondwana rift-deposits, could have good potential for hydrocarbon generation. Current hydrocarbon assessments of the Ross Sea and adjacent areas must be considered highly speculative because the deeply buried rift(?) strata have not been sampled in situ. The assessment of the Ross Sea relies on geophysical/geologic data, two-stage rift models, and data from formerly nearby Gondwana rift-basins. We conclude that conditions favorable for hydrocarbon generation and entrapment are likely throughout the Ross Sea, and especially in the Victoria Land basin, if adequate source beds exist. -Authors

  5. Carbon and hydrogen isotopic composition of methane and C2+ alkanes in electrical spark discharge: implications for identifying sources of hydrocarbons in terrestrial and extraterrestrial settings.

    PubMed

    Telling, Jon; Lacrampe-Couloume, Georges; Sherwood Lollar, Barbara

    2013-05-01

    The low-molecular-weight alkanes--methane, ethane, propane, and butane--are found in a wide range of terrestrial and extraterrestrial settings. The development of robust criteria for distinguishing abiogenic from biogenic alkanes is essential for current investigations of Mars' atmosphere and for future exobiology missions to other planets and moons. Here, we show that alkanes synthesized during gas-phase radical recombination reactions in electrical discharge experiments have values of δ(2)H(methane)>δ(2)H(ethane)>δ(2)H(propane), similar to those of the carbon isotopes. The distribution of hydrogen isotopes in gas-phase radical reactions is likely due to kinetic fractionations either (i) from the preferential incorporation of (1)H into longer-chain alkanes due to the more rapid rate of collisions of the smaller (1)H-containing molecules or (ii) by secondary ion effects. Similar δ(13)C(C1-C2+) and δ(2)H(C1-C2+) patterns may be expected in a range of extraterrestrial environments where gas-phase radical reactions dominate, including interstellar space, the atmosphere and liquid hydrocarbon lakes of Saturn's moon Titan, and the outer atmospheres of Jupiter, Saturn, Neptune, and Uranus. Radical recombination reactions at high temperatures and pressures may provide an explanation for the combined reversed δ(13)C(C1-C2+) and δ(2)H(C1-C2+) patterns of terrestrial alkanes documented at a number of high-temperature/pressure crustal sites.

  6. Size-distribution of airborne polycyclic aromatic hydrocarbons and other organic source markers in the surroundings of a cement plant powered with alternative fuels.

    PubMed

    Sánchez-Soberón, Francisco; van Drooge, Barend L; Rovira, Joaquim; Grimalt, Joan O; Nadal, Martí; Domingo, José L; Schuhmacher, Marta

    2016-04-15

    The distributions of polycyclic aromatic hydrocarbons (PAHs) and molecular tracer organic compounds for biomass combustion, traffic emissions, soil dust, and secondary aerosol processing have been studied in three fractions of ambient air particulate matter (PM10, 2.5, and 1) collected in the vicinity of a cement plant. PAH concentrations were used to estimate the carcinogenic risks in humans. Combustion related compounds, including PAHs, and those from secondary aerosol processing, predominated in the finest (PM<1) fraction, while saccharides related to organic soil dust predominated in the coarse fraction (2.5

  7. Hydrocarbon source potential and maturation in eocene New Zealand vitrinite-rich coals: Insights from traditional coal analyses, and Rock-Eval and biomarker studies

    USGS Publications Warehouse

    Newman, J.; Price, L.C.; Johnston, J.H.

    1997-01-01

    The results of traditional methods of coal characterisation (proximate, specific energy, and ultimate analyses) for 28 Eocene coal samples from the West Coast of New Zealand correspond well with biomarker ratios and Rock-Eval analyses. Isorank variations in vitrinite fluorescence and reflectance recorded for these samples are closely related to their volatile-matter content, and therefore indicate that the original vitrinite chemistry is a key controlling factor. By contrast, the mineral-matter content and the proportion of coal macerals present appear to have had only a minor influence on the coal samples' properties. Our analyses indicate that a number of triterpane biomarker ratios show peak maturities by high volatile bituminous A rank; apparent maturities are then reversed and decline at the higher medium volatile bituminous rank. The Rock-Eval S1 +S2 yield also maximizes by high volatile bituminous A rank, and then declines; however, this decline is retarded in samples with the most hydrogen-rich (perhydrous) vitrinites. These Rock-Eval and biomarker trends, as well as trends in traditional coal analyses, are used to define the rank at which expulsion of gas and oil occurs from the majority of the coals. This expulsion commences at high volatile A bituminous rank, and persists up to the threshold of medium volatile bituminous rank (c. 1.1% Ro ran. or 1.2% Ro max in this sample set), where marked hydrocarbon expulsion from perhydrous vitrinites begins to take place.

  8. In vitro digestive fluid extraction as a measure of the bioavailability of sediment-associated polycyclic aromatic hydrocarbons: Sources of variation and implications for partitioning models

    SciTech Connect

    Weston, D.P.; Mayer, L.M.

    1998-05-01

    In vitro extraction of contaminated sediments using the digestive fluid of a deposit-feeding polychaete has recently been proposed to study contaminant bioaccumulation mechanisms and perhaps to better quantify the bioavailable contaminant fraction. This approach was evaluated using digestive fluid from the polychaete Arenicola brasiliensis and six marine sediments containing both spiked radiolabeled polycyclic aromatic hydrocarbons (PAHs) and in situ-contaminated unlabeled PAHs. The proportion of total contaminant extracted by digestive fluid from each sediment varied from 22 to 71% and 13 to 52%, for phenanthrene and benzo[a]pyrene, respectively. The proportions of contaminant solubilized were inversely correlated with the sediments` organic carbon content. The extent of PAH solubilization among sediments by A. brasiliensis digestive fluid was highly correlated with that of digestive fluid from the echiuran Urechis caupo and appears to be a consequence of surfactant properties of the fluids rather than of their enzymatic activity. The proportion of PAHs solubilized in vitro was similar to in vivo measurements of solubilization for contaminant exposures lasting about 24 h. However, with continued exposure, in vivo PAH concentrations in the digestive fluid increased fivefold, suggesting that digestive fluid is retained in the gut longer than sediment and thus accumulates PAHs through sequential digestion of many gut volumes. This phenomenon may enhance contaminant fugacity in the gut and increase the potential for bioaccumulation or toxicity.

  9. Biodegradation of hydrocarbons vapors: Comparison of laboratory studies and field investigations in the vadose zone at the emplaced fuel source experiment, Airbase Vaerløse, Denmark.

    PubMed

    Höhener, Patrick; Dakhel, Nathalie; Christophersen, Mette; Broholm, Mette; Kjeldsen, Peter

    2006-12-15

    The natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone can only be predicted when information about microbial biodegradation rates and kinetics are known. This study aimed at determining first-order rate coefficients for the aerobic biodegradation of 13 volatile petroleum hydrocarbons which were artificially emplaced as a liquid mixture during a field experiment in an unsaturated sandy soil. Apparent first-order biodegradation rate coefficients were estimated by comparing the spatial evolution of the resulting vapor plumes to an analytical reactive transport model. Two independent reactive numerical model approaches have been used to simulate the diffusive migration of VOC vapors and to estimate degradation rate coefficients. Supplementary laboratory column and microcosm experiments were performed with the sandy soil at room temperature under aerobic conditions. First-order kinetics adequately matched the lab column profiles for most of the compounds. Consistent compound-specific apparent first-order rate coefficients were obtained by the three models and the lab column experiment, except for benzene. Laboratory microcosm experiments lacked of sensitivity for slowly degrading compounds and underestimated degradation rates by up to a factor of 5. Addition of NH3 vapor was shown to increase the degradation rates for some VOCs in the laboratory microcosms. All field models suggested a significantly higher degradation rate for benzene than the rates measured in the lab, suggesting that the field microbial community was superior in developing benzene degrading activity.

  10. Synthesis of waste interception and allocation networks

    SciTech Connect

    El-Halwagi, M.M.; Hamad, A.A.; Garrison, G.W.

    1996-11-01

    This article introduces the novel concept of synthesizing waste-interception networks (WINs) and incorporates it within a mass-integration framework for the global allocation of pollutants. The essence of this notion is to provide selective interception and rerouting of undesirable species at the heart of the process instead of dealing with the pollutants in the terminal waste streams. It also provides a unified framework for simultaneously tackling gaseous and liquid pollution. Several tools are developed to track the pollutant throughout the process and determine the optimal interception policies. The problem is formulated as an optimization program that seeks to determine the optimum locations for interception the pollutants, extent of separation, and separating agents to carry out the interception tasks. Furthermore, the WINs can be used within a mass-integration scheme for the global allocation of species throughout the plant. These new concepts and associated mathematical formulation are demonstrated using a case study on the removal of a chlorinated hydrocarbon. This approach has benefits over conventional recycle/reuse (such as MEN synthesis).

  11. Characterization, ecological risk assessment and source diagnostics of polycyclic aromatic hydrocarbons in water column of the Yellow River Delta, one of the most plenty biodiversity zones in the world.

    PubMed

    Wang, Lili; Yang, Zhifeng; Niu, Junfeng; Wang, Jingyi

    2009-09-30

    As one of the most active regions of land-ocean interaction among the large river deltas in the world, the Yellow River Delta (YRD) gains increasing concern on its ecological and environmental conditions. However, few studies on polycyclic aromatic hydrocarbons (PAHs) have been reported for this area. In this study, the distribution characteristics, probabilistic risk and possible sources of PAHs were investigated in the water column of the YRD. The PAH concentrations were found to be at relatively low or medium levels (121.3 ng L(-1) in water and 209.1n g g(-1) in suspended particulate matter (SPM) on average), and the result of probability risk assessment additionally elucidated low PAH ecological risk in the YRD. The PAH composition showed that low and moderate molecular PAHs were the major species in water phase, whereas the SPM showed a different proportion of each PAH composition. An interesting result was found that low-ring PAHs and salinity in this land-ocean interaction area had a positive relationship (R=0.609). For PAH source identification, both diagnostic ratios of selected PAHs and principal component analysis (PCA) with multiple linear regression (MLR) analysis were studied, suggesting mixed sources of pyrogenic and petrogenic deriving PAHs in the YRD.

  12. Computationally efficient control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne (Inventor)

    2001-01-01

    A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

  13. Evaluation of hydrocarbon potential

    SciTech Connect

    Cashman, P.H.; Trexler, J.H. Jr.

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  14. Impact of oxidation and biodegradation on the most commonly used polycyclic aromatic hydrocarbon (PAH) diagnostic ratios: Implications for the source identifications.

    PubMed

    Biache, Coralie; Mansuy-Huault, Laurence; Faure, Pierre

    2014-02-28

    Based on the isomer stability during their formation, PAH diagnostic ratios have been extensively used to determine PAH contamination origin. Nevertheless, it is known that these isomers do not present the same physicochemical properties and that reactions occurring during the transport from an atmospheric source induce changes in the diagnostic ratios. Yet, little is known about reactions occurring in soils contaminated by other sources such as coal tar and coal. Innovative batch experiments of abiotic oxidation and microbial incubations were performed to discriminate independently the influence of these two major processes occurring in soils on the diagnostic ratios of major PAH sources. Three samples were studied, a coking plant soil and two major PAH sources in this soil, namely coal and coal tar. The combustion signature of the coking plant soil showed the major influence of coal tar in the soil sample composition. Some of these ratios were drastically affected by oxidation and biodegradation processes inducing a change in the source signature. The coal tar signature changed to petrogenic source after oxidation with the anthracene/(anthracene+phenanthrene) ratio. According to this ratio, the initial petrogenic signature of the coal changed to a combustion signature after the biodegradation experiment.

  15. Occurrence and implications of methyl tert-butyl ether and gasoline hydrocarbons in ground water and source water in the United States and in drinking water in 12 Northeast and Mid-Atlantic States, 1993-2002

    USGS Publications Warehouse

    Moran, Michael J.; Zogorski, John S.; Squillace, Paul J.

    2004-01-01

    The occurrence and implications of methyl tert-butyl ether (MTBE) and gasoline hydrocarbons were examined in three surveys of water quality conducted by the U.S. Geological Survey?one national-scale survey of ground water, one national-scale survey of source water from ground water, and one regional-scale survey of drinking water from ground water. The overall detection frequency of MTBE in all three surveys was similar to the detection frequencies of some other volatile organic compounds (VOCs) that have much longer production and use histories in the United States. The detection frequency of MTBE was higher in drinking water and lower in source water and ground water. However, when the data for ground water and source water were limited to the same geographic extent as drinking-water data, the detection frequencies of MTBE were comparable to the detection frequency of MTBE in drinking water. In all three surveys, the detection frequency of any gasoline hydrocarbon was less than the detection frequency of MTBE. No concentration of MTBE in source water exceeded the lower limit of U.S. Environmental Protection Agency's Drinking-Water Advisory of 20 ?g/L (micrograms per liter). One concentration of MTBE in ground water exceeded 20 ?g/L, and 0.9 percent of drinking-water samples exceeded 20 ?g/L. The overall detection frequency of MTBE relative to other widely used VOCs indicates that MTBE is an important concern with respect to ground-water management. The probability of detecting MTBE was strongly associated with population density, use of MTBE in gasoline, and recharge, and weakly associated with density of leaking underground storage tanks, soil permeability, and aquifer consolidation. Only concentrations of MTBE above 0.5 ?g/L were associated with dissolved oxygen. Ground water underlying areas with high population density, ground water underlying areas where MTBE is used as a gasoline oxygenate, and ground water underlying areas with high recharge has a greater

  16. Research on allocation efficiency of the daisy chain allocation algorithm

    NASA Astrophysics Data System (ADS)

    Shi, Jingping; Zhang, Weiguo

    2013-03-01

    With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

  17. Hydrocarbon release investigations in Missouri

    SciTech Connect

    Fels, J.B.

    1996-09-01

    Hydrocarbon releases are among the most common environmental problems in Missouri, as well as across the country. Old, unprotected underground storage tanks and buried piping from the tanks to pumps are notorious sources of petroleum contamination at LUST (leaking underground storage tank) sites. Missouri has an estimated 5000 LUST sites across the state with the majority being simple spills into clay-rich soils or into a shallow perched water system. However, in the southern half of the state, where residual soils and karst bedrock are not conducive to trapping such releases, significant groundwater supplies are at risk. This article discusses the process used to identify the source of contamination.

  18. Pollution assessment and source identifications of polycyclic aromatic hydrocarbons in sediments of the Yellow River Delta, a newly born wetland in China.

    PubMed

    Yang, Zhifeng; Wang, Lili; Niu, Junfeng; Wang, Jingyi; Shen, Zhenyao

    2009-11-01

    The levels and possible sources of 16 priority polycyclic aromatic carbons (PAHs) in the sediments from the Yellow River Delta (YRD) were investigated. The total PAH concentrations ranged from 23.9 to 520.6 microg kg(-1) with a mean value of 150.9 microg kg(-1), indicating low or medium levels compared with reported values of other deltas. The concentrations of the 16 individual PAHs presented varied profiles among different regions. The ecological risk assessment of PAHs showed that adverse effects would rarely occur in the sediments of the YRD based on the effect range-low quotients and the probability risk assessment. The PAH compositions and the principal component analysis (PCA) with multiple linear regression (MLR) uniformly presumed the mixed sources of pyrogenic- and petrogenic-deriving PAHs in the YRD. By PCA with MLR, the contributions of major sources were quantified as 36.4% from oil burning, 33.1% from biomass combustion, and 30.5% from diesel emission sources.

  19. Hydrocarbons in coastal sediments from the Mediterranean sea (Gulf of Fos area, France).

    PubMed

    Mille, Gilbert; Asia, Laurence; Guiliano, Michel; Malleret, Laure; Doumenq, Pierre

    2007-05-01

    Sedimentary hydrocarbons have been studied quantitatively and qualitatively in 11 coastal stations located in the Gulf of Fos (French Mediterranean coast). Hydrocarbon levels ranged from 10 to 260 mg kg(-1) sed. dry weight. A new parameter "NAR" (Natural n-alkane ratio) is proposed to evaluate the contribution of terrestrial inputs of hydrocarbons in the sediments. The origins of hydrocarbons are multiple: terrestrial inputs, biogenic, pyrolytic (industry emissions mainly steel and iron industries, ship and road traffic). Generally, the main source of contamination is not petroleum. Several ratios between parent polycyclic aromatic hydrocarbons show that the sources of hydrocarbons in the sediments are generally much more pyrolytic than petrogenic.

  20. Anthropogenic non-methane volatile hydrocarbons at Mt. Cimone (2165 m a.s.l., Italy): Impact of sources and transport on atmospheric composition

    NASA Astrophysics Data System (ADS)

    Lo Vullo, Eleonora; Furlani, Francesco; Arduini, Jgor; Giostra, Umberto; Graziosi, Francesco; Cristofanelli, Paolo; Williams, Martin L.; Maione, Michela

    2016-09-01

    To advance our understanding of the factors that affect pollution in mountainous areas, long-term, high frequency measurements of thirteen Non Methane Volatile Organic Compounds (NMVOCs) have been carried out at the atmospheric observatory on the top of Mt. Cimone (2165 m a.s.l.), whose location is ideal for sampling both aged air masses representing the regional background and polluted air masses coming from nearby sources of anthropogenic pollution. An analysis of the NMVOC time series available at Mt. Cimone during 2010-2014 was used to examine the influence of transport processes on NMVOC atmospheric composition and to derive information on the emission sources. We performed a multifactor principal component analysis whose results allowed us to identify the source categories emitting the NMVOCs measured at Mt. Cimone as well as to assess transport ranges in winter and summer. Aged air masses, due to long-range transport and related to vehicular traffic exhaust emissions accounted for 78% of the NMVOC variability in winter and 62% in summer, whereas evaporative emissions, likely to be associated with fresh emissions from nearby sources, accounted for 12% of the NMVOC variability and 24% in winter and summer, respectively. Such results have been confirmed by a further analysis in which the NMVOC variability as a function of their atmospheric lifetimes has been evaluated. The ratios of alkane isomers potentially provides a metric to investigate seasonal changes in NMVOCs composition and in the emission fields of butanes and pentanes, suggesting that during the summer the butanes are originating mainly from the European domain and that for pentanes non-anthropogenic sources may be contributing to the measured concentrations.

  1. Ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Changhua County, central Taiwan: Seasonal variation, source apportionment and cancer risk assessment.

    PubMed

    Chen, Yu-Cheng; Chiang, Hung-Che; Hsu, Chin-Yu; Yang, Tzu-Ting; Lin, Tzu-Yu; Chen, Mu-Jean; Chen, Nai-Tzu; Wu, Yuh-Shen

    2016-11-01

    This study investigates PM2.5-bound PAHs for rural sites (Dacheng and Fangyuan) positioned close to heavy air-polluting industries in Changhua County, central Taiwan. A total of 113 PM2.5 samples with 22 PAHs collected from 2014 to 2015 were analyzed, and Positive Matrix Factorization (PMF) and diagnostic ratios of PAHs were applied to quantify potential PAH sources. The influences of local and regional sources were also explored using the conditional probability function (CPF) and potential source contribution function (PSCF) with PMF-modeled results, respectively. Annual mean concentrations of total PAHs were 2.91 ± 1.34 and 3.04 ± 1.40 ng/m(3) for Dacheng and Fangyuan, respectively, and their corresponding BaPeq were measured at 0.534 ± 0.255 and 0.563 ± 0.273 ng/m(3) in concentration. Seasonal variations with higher PAHs found for the winter than for the spring and summer were observed for both sites. The lifetime excess cancer risk (ECR) from inhalation exposure to PAHs was recorded as 4.7 × 10(-5) overall. Potential sources of PM2.5-bound PAHs include unburned petroleum and traffic emissions (42%), steel industry and coal combustion (31%), and petroleum and oil burning (27%), and unburned petroleum and traffic emission could contribute the highest ECR (2.4 × 10(-5)). The CPF results show that directional apportionment patterns were consistent with the actual locations of local PAH sources. The PSCF results indicate that mainly northeastern regions of China have contributed elevated PM2.5-bound PAHs from long-range transports.

  2. Hydrocarbon potential of Morocco

    SciTech Connect

    Achnin, H.; Nairn, A.E.M.

    1988-08-01

    Morocco lies at the junction of the African and Eurasian plates and carries a record of their movements since the end of the Precambrian. Four structural regions with basins and troughs can be identified: Saharan (Tarfaya-Ayoun and Tindouf basins); Anti-Atlas (Souss and Ouarzazate troughs and Boudnib basin); the Essaouria, Doukkala, Tadla, Missour, High Plateau, and Guercif basins; and Meseta and Rif (Rharb and Pre-Rif basins). The targets in the Tindouf basin are Paleozoic, Cambrian, Ordovician (clastics), Devonian (limestones), and Carboniferous reservoirs sourced primarily by Silurian shales. In the remaining basins, excluding the Rharb, the reservoirs are Triassic detritals, limestones at the base of the Lias and Dogger, Malm detritals, and sandy horizons in the Cretaceous. In addition to the Silurian, potential source rocks include the Carboniferous and Permo-Carboniferous shales and clays; Jurassic shales, marls, and carbonates; and Cretaceous clays. In the Rharb basin, the objectives are sand lenses within the Miocene marls. The maturation level of the organic matter generally corresponds to oil and gas. The traps are stratigraphic (lenses and reefs) and structural (horsts and folds). The seals in the pre-Jurassic rocks are shales and evaporites; in the younger rocks, shales and marl. Hydrocarbon accumulations have been found in Paleozoic, Triassic, Liassic, Malm, and Miocene rocks.

  3. Polycyclic aromatic hydrocarbons in sediments from the Old Yellow River Estuary, China: occurrence, sources, characterization and correlation with the relocation history of the Yellow River.

    PubMed

    Yuan, Zijiao; Liu, Guijian; Wang, Ruwei; Da, Chunnian

    2014-11-01

    The levels of 16 USEPA priority PAHs were determined in surface sediments and one dated sediment core from the abandoned Old Yellow River Estuary, China. Total PAH concentrations in the surface sediments ranged from 100.4 to 197.3 ng g(-1) dry weight and the total toxic equivalent quantity (TEQ(carc)) values of the carcinogenic PAHs were very low. An evaluation of PAH sources based on diagnostic ratios and principal component analysis suggested that PAHs in the surface sediments mainly derived from combustion sources. The total PAH concentrations altered significantly with year of deposition and showed quite different patterns of change compared with other studies: it is hypothesized that the principal cause of these changes is the relocation of the course of the Yellow River to the sea in 1976 and 1996.

  4. Distribution and sources of polycyclic aromatic hydrocarbons in size-differentiated re-suspended dust on building surfaces in an oilfield city, China

    NASA Astrophysics Data System (ADS)

    Kong, Shaofei; Lu, Bing; Ji, Yaqin; Bai, Zhipeng; Xu, Yonghai; Liu, Yong; Jiang, Hua

    2012-08-01

    Thirty re-suspended dust samples were collected from building surfaces in an oilfield city, re-suspended and sampled through PM2.5, PM10 and PM100 inlets and analyzed for 18 PAHs by GC-MS technique. PAHs concentrations, toxicity and profiles characteristic for different districts and size were studied. PAHs sources were identified by diagnostic ratios and primary component analysis. Results showed that the total amounts of analyzed PAHs in re-suspended dust in Dongying were 45.29, 23.79 and 11.41 μg g-1 for PM2.5, PM10 and PM100, respectively. PAHs tended to concentrate in finer particles with mass ratios of PM2.5/PM10 and PM10/PM100 as 1.96 ± 0.86 and 2.53 ± 1.57. The old district with more human activities and long oil exploitation history exhibited higher concentrations of PAHs from both combustion and non-combustion sources. BaP-based toxic equivalent factor and BaP-based equivalent carcinogenic power exhibited decreasing sequence as PM2.5 > PM10 > PM100 suggesting that the finer the particles, the more toxic of the dust. NaP, Phe, Flu, Pyr, BbF and BghiP were the abundant species. Coefficient of divergence analysis implied that PAHs in different districts and size fractions had common sources. Coal combustion, industrial sources, vehicle emission and petroleum were probably the main contributions according to the principal component analysis result.

  5. Historical records and sources of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in sediment from a representative plateau lake, China.

    PubMed

    Yuan, Hezhong; Liu, Enfeng; Zhang, Enlou; Luo, Wenlei; Chen, Liang; Wang, Cheng; Lin, Qi

    2017-04-01

    The PAH and OCP concentrations in sediment cores collected from a deep lake were measured and evaluated chronologically. The results indicated that the PAH and OCP concentrations significantly increased from the 1950s to the 1990s and subsequently decreased to recent years. Integrated molecular diagnostic ratios indicated that the predominant petrogenic sources occurred from the 1950s-1980s. Petroleum and fuel combustion dominated the source of contamination more recently as a result of energy structure changes in this region. Additionally, HCHs and DDTs were the dominant OCP compounds, making up a majority of the total OCPs present (>85%). HCHs accounted for a larger ratio of the OCPs between the 1950s and 1980s, suggesting that HCHs were the dominant POPs in this period. DDTs then became dominant in the 1980s and later. High α/γ-HCH ratios suggested that the emission and conversion of local technical HCHs were the predominant HCHs source. The ratios of (DDE + p,p'-DDD)/DDTs and p,p'-DDT/DDTs indicated that the DDTs mainly originated from historical input. In addition, the dramatic decrease since the 1980s may be the result of China's banning of DDTs. However, DDTs were still present in the 1990s, suggesting DDTs were still used in this region and beyond.

  6. Source apportionment of atmospheric PM2.5-bound polycyclic aromatic hydrocarbons by a PMF receptor model. Assessment of potential risk for human health.

    PubMed

    Callén, María Soledad; Iturmendi, Amaia; López, José Manuel

    2014-12-01

    One year sampling (2011-2012) campaign of airborne PM2.5-bound PAH was performed in Zaragoza, Spain. A source apportionment of total PAH by Positive Matrix Factorization (PMF) was applied in order to quantify potential PAH pollution sources. Four sources were apportioned: coal combustion, vehicular emissions, stationary emissions and unburned/evaporative emissions. Although Directive 2004/107/EC was fulfilled regarding benzo(a)pyrene (BaP), episodes exceeding the limit value of PM2.5 according to Directive 2008/50/EC were found. These episodes of high negative potential for human health were studied, obtaining a different pattern for the exceedances of PM2.5 and the lower assessment threshold of BaP (LATBaP). In both cases, stationary emissions contributed majority to total PAH. Lifetime cancer risk exceeded the unit risk recommended by the World Health Organization for those episodes exceeding the LATBaP and the PM2.5 exceedances for the warm season. For the cold season, the risk was higher for the LATBaP than for the PM2.5 exceedances.

  7. Dynamic advance reservation with delayed allocation

    SciTech Connect

    Vokkarane, Vinod; Somani, Arun

    2014-12-02

    A method of scheduling data transmissions from a source to a destination, includes the steps of: providing a communication system having a number of channels and a number of paths, each of the channels having a plurality of designated time slots; receiving two or more data transmission requests; provisioning the transmission of the data; receiving data corresponding to at least one of the two or more data transmission requests; waiting until an earliest requested start time T.sub.s; allocating at the current time each of the two or more data transmission requests; transmitting the data; and repeating the steps of waiting, allocating, and transmitting until each of the two or more data transmission requests that have been provisioned for a transmission of data is satisfied. A system to perform the method of scheduling data transmissions is also described.

  8. Innovative Approach for Developing Spacecraft Interior Acoustic Requirement Allocation

    NASA Technical Reports Server (NTRS)

    Chu, S. Reynold; Dandaroy, Indranil; Allen, Christopher S.

    2016-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) is an American spacecraft for carrying four astronauts during deep space missions. This paper describes an innovative application of Power Injection Method (PIM) for allocating Orion cabin continuous noise Sound Pressure Level (SPL) limits to the sound power level (PWL) limits of major noise sources in the Environmental Control and Life Support System (ECLSS) during all mission phases. PIM is simulated using both Statistical Energy Analysis (SEA) and Hybrid Statistical Energy Analysis-Finite Element (SEA-FE) models of the Orion MPCV to obtain the transfer matrix from the PWL of the noise sources to the acoustic energies of the receivers, i.e., the cavities associated with the cabin habitable volume. The goal of the allocation strategy is to control the total energy of cabin habitable volume for maintaining the required SPL limits. Simulations are used to demonstrate that applying the allocated PWLs to the noise sources in the models indeed reproduces the SPL limits in the habitable volume. The effects of Noise Control Treatment (NCT) on allocated noise source PWLs are investigated. The measurement of source PWLs of involved fan and pump development units are also discussed as it is related to some case-specific details of the allocation strategy discussed here.

  9. Resource Balancing Control Allocation

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Bodson, Marc

    2010-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the control effort. The paper discusses the alternative choice of using the l1 norm for minimization of the tracking error and a normalized l(infinity) norm, or sup norm, for minimization of the control effort. The algorithm computes the norm of the actuator deflections scaled by the actuator limits. Minimization of the control effort then translates into the minimization of the maximum actuator deflection as a percentage of its range of motion. The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are investigated through examples. In particular, the min-max criterion results in a type of resource balancing, where the resources are the control surfaces and the algorithm balances these resources to achieve the desired command. A study of the sensitivity of the algorithms to the data is presented, which shows that the normalized l(infinity) algorithm has the lowest sensitivity, although high sensitivities are observed whenever the limits of performance are reached.

  10. Concentration and sources of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in surface soil near a municipal solid waste (MSW) landfill.

    PubMed

    Melnyk, A; Dettlaff, A; Kuklińska, K; Namieśnik, J; Wolska, L

    2015-10-15

    Due to a continuous demand of land for infrastructural and residential development there is a public concern about the condition of surface soil near municipal solid waste landfills. A total of 12 surface (0-20 cm) soil samples from a territory near a landfill were collected and the concentration of 16 PAHs and 7 PCB congeners were investigated in these samples. Limits of detection were in the range of 0.038-1.2 μg/kg for PAHs and 0.025-0.041 μg/kg for PCBs. The total concentration of ∑ PAHs ranged from 892 to 3514 μg/kg with a mean of 1974 μg/kg. The total concentration of ∑ PCBs ranged from 2.5 to 12 μg/kg with a mean of 4.5 μg/kg. Data analyses allowed to state that the PAHs in surface soils near a landfill were principally from pyrogenic sources. Due to air transport, PAHs forming at the landfill are transported outside the landfill. PCB origin is not connected with the landfill. Aroclor 1242 can be the source of PCBs in several samples.

  11. Patch Network for Power Allocation and Distribution in Smart Materials

    NASA Technical Reports Server (NTRS)

    Golembiewski, Walter T.

    2000-01-01

    The power allocation and distribution (PAD) circuitry is capable of allocating and distributing a single or multiple sources of power over multi-elements of a power user grid system. The purpose of this invention is to allocate and distribute power that is collected by individual patch rectennas to a region of specific power-user devices, such as actuators. The patch rectenna converts microwave power into DC power. Then this DC power is used to drive actuator devices. However, the power from patch rectennas is not sufficient to drive actuators unless all the collected power is effectively used to drive another group by allocation and distribution. The power allocation and distribution (PAD) circuitry solves the shortfall of power for devices in a large array. The PAD concept is based on the networked power control in which power collected over the whole array of rectennas is allocated to a sub domain where a group of devices is required to be activated for operation. Then the allocated power is distributed to individual element of power-devices in the sub domain according to a selected run-mode.

  12. An Approach that Uses the Concentrations of Hydrocarbon Compounds in Soil Gas at the Source of Contamination to Evaluate the Potential for Intrusion of Petroleum Vapors into Buildings (PVI)

    EPA Science Inventory

    If motor fuels are spilled from underground storage tanks, petroleum hydrocarbons can vaporize from the spill and move as a vapor through the unsaturated zone. If a building is sited above or near the spill, the hydrocarbons may intrude into the air space of the building. This ...

  13. Resource allocation using risk analysis

    SciTech Connect

    Bott, T. F.; Eisenhawer, S. W.

    2003-01-01

    Allocating limited resources among competing priorities is an important problem in management. In this paper we describe an approach to resource allocation using risk as a metric. We call this approach the Logic-Evolved Decision (LED) approach because we use logic-models to generate an exhaustive set of competing options and to describe the often highly complex model used for evaluating the risk reduction achieved by different resource allocations among these options. The risk evaluation then proceeds using probabilistic or linguistic input data.

  14. Zinc allocation and re-allocation in rice

    PubMed Central

    Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

    2014-01-01

    Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

  15. Hydrocarbon Spectral Database

    National Institute of Standards and Technology Data Gateway

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  16. Oxygenated Derivatives of Hydrocarbons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  17. Recovering hydrocarbons from hydrocarbon-containing vapors

    DOEpatents

    Mirza, Zia I.; Knell, Everett W.; Winter, Bruce L.

    1980-09-30

    Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

  18. Variation of polycyclic aromatic hydrocarbons in atmospheric PM2.5 during winter haze period around 2014 Chinese Spring Festival at Nanjing: Insights of source changes, air mass direction and firework particle injection.

    PubMed

    Kong, Shaofei; Li, Xuxu; Li, Li; Yin, Yan; Chen, Kui; Yuan, Liang; Zhang, Yingjie; Shan, Yunpeng; Ji, Yaqin

    2015-07-01

    Daily PM2.5 samples were collected at a suburban site of Nanjing around 2014 Chinese Spring Festival (SF) and analyzed for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) by GC-MS. Comparison of PAH concentrations during different periods, with different air mass origins and under different pollution situations was done. Sources were analyzed by diagnostics ratios and principal component analysis (PCA). The threat of PAHs was assessed by BaP equivalent concentrations (BaPeq) and incremental lifetime cancer risk (ILCR). The averaged PAHs for pre-SF, SF and after SF periods were 50.6, 17.2 and 29 ng m(-3), indicating the variations of PAH sources, with reduced traffic, industrial and construction activities during SF and gradually re-starting of them after-SF. According to PAH mass concentrations, their relative abundance to particles, ratio of PAHs (3-ring+4-ring)/PAHs(5-ring+6-ring), mass concentrations of combustion-derived and carcinogenic PAHs, fireworks burning is an important source for PAHs during SF. The ILCR values for Chinese New Year day were 0.68 and 3.3 per 100,000 exposed children and adults. It suggested the necessity of controlling fireworks burning during Chinese SF period which was always companied with serious regional haze pollution. PAH concentrations exhibited decreasing trend when air masses coming from the following directions as North China Plain (63.9 ng m(-3))>Central China (53.0 ng m(-3))>Shandong Peninsula (46.6 ng m(-3))>Northwest China (18.8 ng m(-3))>Sea (15.8 ng m(-3)). For different pollution situations, they decreased as haze (44.5 ng m(-3))>fog-haze (28.4 ng m(-3))>clear (12.2 ng m(-3))>fog day (9.2 ng m(-3)). Coal combustion, traffic emission, industrial processes and petroleum (only for non-SF holiday periodss) were the main sources of PM2.5 associated PAHs. Fireworks burning contributed 14.0% of PAHs during SF period. Directly measurement of PAHs from fireworks burning is urgently needed for source apportionment studies in

  19. Molecular carbon isotopic evidence for the origin of geothermal hydrocarbons

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.; Donchin, J. H.; Nehring, N. L.; Truesdell, A. H.

    1981-01-01

    Isotopic measurements of individual geothermal hydrocarbons that are, as a group, of higher molecular weight than methane are reported. It is believed in light of this data that the principal source of hydrocarbons in four geothermal areas in western North America is the thermal decomposition of sedimentary or groundwater organic matter.

  20. Polycyclic aromatic hydrocarbons in the coastal sea water, the surface sediment and Mudskipper Boleophthalmus dussumieri from coastal areas of the Persian Gulf: source investigation, composition pattern and spatial distribution

    PubMed Central

    2014-01-01

    Background Persian Gulf is an exposed and stressed area as a result of oil pollution and other fossil fuels containing PAHs. The susceptibility of using mudskippers to monitor marine pollution, like PAHs, points to the fact that mudskippers are able to accumulate and record the PAHs presented in the coastal environments. Methods Polycyclic aromatic hydrocarbons (PAHs) were examined in the coastal waters, the sediments and biota (i.e., Boleophthalmus dussumieri) along the coast of the Persian Gulf. PAHs concentrations were measured with HPLC method. Results Total PAH concentrations in the sea water, the sediments, the liver and the gill tissues ranged between 0.80-18.34 μg/l, 113.50-3384.34 ng g-1 (d w), 3.99-46.64 ng g-1 (d w) and 3.11-17.76 ng g-1 (d w), respectively. PAHs distribution patterns in the sediment and the liver tissue samples were dominated by three-and four-ring structures whereas two-and three-rings were dominated in the water and the gill. Conclusions This finding revealed a negative eco-risk effects occasionally occur in this area. The higher presence of low condensate ring structures reflected a predominant origin of petrogenic and some cases of pyrolitic sources. PMID:24612928

  1. Collaborative Resource Allocation

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Raymond; Baldwin, John; Borden, Chester

    2007-01-01

    Collaborative Resource Allocation Networking Environment (CRANE) Version 0.5 is a prototype created to prove the newest concept of using a distributed environment to schedule Deep Space Network (DSN) antenna times in a collaborative fashion. This program is for all space-flight and terrestrial science project users and DSN schedulers to perform scheduling activities and conflict resolution, both synchronously and asynchronously. Project schedulers can, for the first time, participate directly in scheduling their tracking times into the official DSN schedule, and negotiate directly with other projects in an integrated scheduling system. A master schedule covers long-range, mid-range, near-real-time, and real-time scheduling time frames all in one, rather than the current method of separate functions that are supported by different processes and tools. CRANE also provides private workspaces (both dynamic and static), data sharing, scenario management, user control, rapid messaging (based on Java Message Service), data/time synchronization, workflow management, notification (including emails), conflict checking, and a linkage to a schedule generation engine. The data structure with corresponding database design combines object trees with multiple associated mortal instances and relational database to provide unprecedented traceability and simplify the existing DSN XML schedule representation. These technologies are used to provide traceability, schedule negotiation, conflict resolution, and load forecasting from real-time operations to long-range loading analysis up to 20 years in the future. CRANE includes a database, a stored procedure layer, an agent-based middle tier, a Web service wrapper, a Windows Integrated Analysis Environment (IAE), a Java application, and a Web page interface.

  2. Subsea hydrocarbon sensor system

    SciTech Connect

    Marosko, R.J.; Warren, W.B.

    1981-08-04

    A hydrocarbon detection system is provided for use in a subsea hydrocarbon production installation which includes production tree assemblies, an electro-hydraulic control module located on the sea floor and remote from the production trees, cable assemblies interconnecting the control module with the production trees through magnetic coupling devices. A pair of inductive elements are electrically coupled by the surrounding sea water. Displacement of the conductive sea water by escaping hydrocarbons affects the coupling between the inductive elements to produce a hydrocarbon-presence-responsive output signal. The inductive elements are resonated within a selected frequency range by capacitors coupled with a primary inductor coil by auxiliary windings on a common core element. An excitation signal sweeps over the selected frequency range at a rate effective to produce a peak detected signal at the resonant frequency. The peak output signal is then monitored to form a control signal functionally related to the presence or absence of hydrocarbons in the sea water.

  3. Methods for natural gas and heavy hydrocarbon co-conversion

    DOEpatents

    Kong, Peter C.; Nelson, Lee O.; Detering, Brent A.

    2009-02-24

    A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.

  4. 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.

  5. Changes in atmospheric concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls between the 1990s and 2010s in an Australian city and the role of bushfires as a source.

    PubMed

    Wang, Xianyu; Thai, Phong K; Li, Yan; Li, Qingbo; Wainwright, David; Hawker, Darryl W; Mueller, Jochen F

    2016-06-01

    Over recent decades, efforts have been made to reduce human exposure to atmospheric pollutants including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) through emission control and abatement. Along with the potential changes in their concentrations resulting from these efforts, profiles of emission sources may have also changed over such extended timeframes. However relevant data are quite limited in the Southern Hemisphere. We revisited two sampling sites in an Australian city, where the concentration data in 1994/5 for atmospheric PAHs and PCBs were available. Monthly air samples from July 2013 to June 2014 at the two sites were collected and analysed for these compounds, using similar protocols to the original study. A prominent seasonal pattern was observed for PAHs with elevated concentrations in cooler months whereas PCB levels showed little seasonal variation. Compared to two decades ago, atmospheric concentrations of ∑13 PAHs (gaseous + particle-associated) in this city have decreased by approximately one order of magnitude and the apparent halving time (t1/2) was estimated as 6.2 ± 0.56 years. ∑6iPCBs concentrations (median value; gaseous + particle-associated) have decreased by 80% with an estimated t1/2 of 11 ± 2.9 years. These trends and values are similar to those reported for comparable sites in the Northern Hemisphere. To characterise emission source profiles, samples were also collected from a bushfire event and within a vehicular tunnel. Emissions from bushfires are suggested to be an important contributor to the current atmospheric concentrations of PAHs in this city. This contribution is more important in cooler months, i.e. June, July and August, and its importance may have increased over the last two decades.

  6. Polycyclic aromatic hydrocarbons (PAHs) in wetland soils under different land uses in a coastal estuary: toxic levels, sources and relationships with soil organic matter and water-stable aggregates.

    PubMed

    Xiao, Rong; Bai, Junhong; Wang, Junjing; Lu, Qiongqiong; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

    2014-09-01

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the soils from industrial, wharf, cropland, milldam and natural wetland sites to characterize their distributions, toxic levels and possible sources in the Pearl River Estuary and identify their relationships with soil organic matter (SOM) and water-stable aggregates (WSAs). Our results indicate that the average concentration of total PAHs in this region reached a moderate pollution level, which was higher than that in other larger estuaries in Asia. The average level of total PAHs in industrial soils was 1.2, 1.5, 1.6 and 2.3 times higher than those in soils from wharf, cropland, milldam and natural wetland sites, respectively. Greater accumulation of PAHs occurred in the middle and/or bottom soil layers where 3-ring PAHs were dominant. Industrial soils also exhibited the highest toxic levels with the highest toxic equivalent concentrations of PAHs, followed by wharf and milldam soils, and the cropland and wetland soils had the lowest toxicity. The diagnostic ratios suggested that PAHs primarily originated from biomass and coal combustion at industrial and milldam sites, and petroleum combustion was determined to be the primary source of PAHs at the wharf, cropland and wetland sites. Both 3-ring and 4-ring PAHs in the milldam and wharf soils were significantly positively correlated with the SOM, whereas the 4,5,6-ring PAHs and total PAHs in industrial soils and the 2-ring PAHs in cropland soils were significantly negatively correlated with the SOM. In addition, large WSAs also exhibited a significant positive correlation with PAHs.

  7. Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle.

    PubMed

    Lea-Smith, David J; Biller, Steven J; Davey, Matthew P; Cotton, Charles A R; Perez Sepulveda, Blanca M; Turchyn, Alexandra V; Scanlan, David J; Smith, Alison G; Chisholm, Sallie W; Howe, Christopher J

    2015-11-03

    Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2-540 pg alkanes per mL per day, which translates into a global ocean yield of ∼ 308-771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities.

  8. Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle

    PubMed Central

    Lea-Smith, David J.; Biller, Steven J.; Davey, Matthew P.; Cotton, Charles A. R.; Perez Sepulveda, Blanca M.; Turchyn, Alexandra V.; Scanlan, David J.; Smith, Alison G.; Chisholm, Sallie W.; Howe, Christopher J.

    2015-01-01

    Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2–540 pg alkanes per mL per day, which translates into a global ocean yield of ∼308–771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities. PMID:26438854

  9. Task 8: Evaluation of hydrocarbon potential

    SciTech Connect

    Cashman, P.H.; Trexler, J.H. Jr.

    1994-12-31

    Our studies focus on the stratigraphy of Late Devonian to early Pennsylvanian rocks at the NTS, because these are the best potential hydrocarbon source rocks in the vicinity of Yucca Mountain. In the last year, our stratigraphic studies have broadened to include the regional context for both the Chainman and the Eleana formations. New age data based on biostratigraphy constrain the age ranges of both Chainman and Eleana; accurate and reliable ages are essential for regional correlation and for regional paleogeographic reconstructions. Source rock analyses throughout the Chainman establish whether these rocks contained adequate organic material to generate hydrocarbons. Maturation analyses of samples from the Chainman determine whether the temperature history has been suitable for the generation of liquid hydrocarbons. Structural studies are aimed at defining the deformation histories and present position of the different packages of Devonian - Pennsylvanian rocks. This report summarizes new results of our structural, stratigraphic and hydrocarbon source rock potential studies at the Nevada Test Site and vicinity. Stratigraphy is considered first, with the Chainman Shale and Eleana Formation discussed separately. New biostratigraphic results are included in this section. New results from our structural studies are summarized next, followed by source rock and maturation analyses of the Chainman Shale. Directions for future work are included where appropriate.

  10. Plasma Processing Of Hydrocarbon

    SciTech Connect

    Grandy, Jon D; Peter C. Kong; Brent A. Detering; Larry D. Zuck

    2007-05-01

    The Idaho National Laboratory (INL) developed several patented plasma technologies for hydrocarbon processing. The INL patents include nonthermal and thermal plasma technologies for direct natural gas to liquid conversion, upgrading low value heavy oil to synthetic light crude, and to convert refinery bottom heavy streams directly to transportation fuel products. Proof of concepts has been demonstrated with bench scale plasma processes and systems to convert heavy and light hydrocarbons to higher market value products. This paper provides an overview of three selected INL patented plasma technologies for hydrocarbon conversion or upgrade.

  11. Assessment of plant-derived hydrocarbons. Final report

    SciTech Connect

    McFadden, K.; Nelson, S.H.

    1981-09-30

    A number of hydrocarbon producing plants are evaluated as possi