Science.gov

Sample records for hydrocarbon source allocation

  1. 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.

  2. 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. PMID:17144278

  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. Bacterial sources for phenylalkane hydrocarbons

    SciTech Connect

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

    1996-10-01

    The presence of phenylalkane hydrocarbons in geochemical samples has been the source of much controversy. Although an anthropogenic input from detergent sources always appears likely, the distribution of phenylalkane hydrocarbons in some cases far exceeding that attributed to detergent input has led to a reappraisal of this view. Indeed, recent work involving analysis of the lipid hydrocarbon extracts from extant Thermoplasma bacteria has revealed the presence of phenylalkane hydrocarbons. The presence of phenylalkane hydrocarbons in sedimentary organic matter may therefore represent potential biological markers for thermophilic bacteria.

  5. 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.

  6. 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.

  7. A bit allocation method for sparse source coding.

    PubMed

    Kaaniche, Mounir; Fraysse, Aurélia; Pesquet-Popescu, Béatrice; Pesquet, Jean-Christophe

    2014-01-01

    In this paper, we develop an efficient bit allocation strategy for subband-based image coding systems. More specifically, our objective is to design a new optimization algorithm based on a rate-distortion optimality criterion. To this end, we consider the uniform scalar quantization of a class of mixed distributed sources following a Bernoulli-generalized Gaussian distribution. This model appears to be particularly well-adapted for image data, which have a sparse representation in a wavelet basis. In this paper, we propose new approximations of the entropy and the distortion functions using piecewise affine and exponential forms, respectively. Because of these approximations, bit allocation is reformulated as a convex optimization problem. Solving the resulting problem allows us to derive the optimal quantization step for each subband. Experimental results show the benefits that can be drawn from the proposed bit allocation method in a typical transform-based coding application.

  8. 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. PMID:24695829

  9. Accounting for Parcel-Allocation Variability in Practice: Combining Sources of Uncertainty and Choosing the Number of Allocations.

    PubMed

    Sterba, Sonya K; Rights, Jason D

    2016-01-01

    Item parceling remains widely used under conditions that can lead to parcel-allocation variability in results. Hence, researchers may be interested in quantifying and accounting for parcel-allocation variability within sample. To do so in practice, three key issues need to be addressed. First, how can we combine sources of uncertainty arising from sampling variability and parcel-allocation variability when drawing inferences about parameters in structural equation models? Second, on what basis can we choose the number of repeated item-to-parcel allocations within sample? Third, how can we diagnose and report proportions of total variability per estimate arising due to parcel-allocation variability versus sampling variability? This article addresses these three methodological issues. Developments are illustrated using simulated and empirical examples, and software for implementing them is provided.

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

    PubMed

    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.

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

    PubMed

    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

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

    DOEpatents

    Miller, David Scott; Uwechue, Uzo Philip

    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.

  14. 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. PMID:25679782

  15. 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

  16. 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.

  17. Expelling of hydrocarbon in undercompacted oil-source rocks

    SciTech Connect

    Zhou, Guojun ); Chen, Fajing )

    1994-08-01

    The clay of source rocks below a certain depth is generally undercompacted. Historical analysis of undercompacted EK2 mudstone in the Huang Hua depression, North China basin, has shown that the peak of the undercompacted zone decreases under a certain depth, mainly due to development of a microfracture caused by abnormally high pressure. Based on the compaction history of mudstones and the hydraulic fracturing condition in this area, the depth of the microfracture developed in the EK2 undercompacted zone is calculated at 2900 m, which is also verified by fluorescence data. Geochemical evidence has also shown that many hydrocarbons are expelled under 2900 m.

  18. 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.

  19. Loss of volatile hydrocarbons from an LNAPL oil source.

    PubMed

    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(10-12)n-alkanes>C(7)-C(9)n-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(9)n-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 29years 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.

  20. 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.

  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. 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. PMID:24569267

  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. Petroleum-specific analytical and interpretive techniques for product identification and source allocation

    SciTech Connect

    Dahlen, D.T.; Uhler, A.D.; Sauer, T.C.; McCarthy, K.J.

    1995-12-31

    As a class, petroleum and refined petroleum products represent the single largest source of contamination to the terrestrial and aquatic environments. Petroleum products including crude oil and a wide spectrum of refined petroleum products are accidentally released by a variety of mechanisms including surface spills, tanker accidents, storage tank leaks, and pipeline ruptures. In many cases, the petroleum and other hydrocarbon products discovered in impacted environments usually cannot be readily linked to a source, because the products are often complex mixtures of various hydrocarbon-based components. The identification of hydrocarbon products in the environment is further confounded by complex physical, chemical, and biological mechanisms that alter the fresh hydrocarbons through processes known collectively as weathering. The dilution, mixing, transport, and weathering of these hydrocarbon materials in the environment renders them very different in composition and appearance from their original source materials. This paper describes the use of EPA methods of analysis that have been modified for measurement of a large suite of petrogenic organic compounds that can be used for sensitive measurement of fresh and degraded petroleum in environmental samples ranging from volatile products such as gasoline to heavy crude oils. Petroleum specific data is reduced using multivariate chemometric techniques including hierarchal cluster analysis (HCA) and principal component analysis to evaluate linkage between the samples and likely petroleum source products. Combined with high quality, petroleum specific data, these analysis techniques offer unparalleled means of identifying materials, differentiating between similar products such as gasolines, and linking contaminated samples to sources. Examples of the use of the methods to deduce sources of gasoline, jet fuel, and diesel to terrestrial spills will be presented.

  6. 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

    2002-04-01

    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. PMID:11932741

  7. 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

    2002-04-01

    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.

  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, 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... monthly data under § 74.20, the opt-in source's opt-in permit may become effective at the beginning of...

  9. [Emission and source characterization of monoaromatic hydrocarbons from coke production].

    PubMed

    He, Qiu-Sheng; Wang, Xin-Ming; Sheng, Guo-Ying; Fu, Jia-Mo

    2005-09-01

    Monoaromatic hydrocarbons (MAHs) from indigenous and industrial coking processes are studied in Shanxi province. They are sampled on the top of coke ovens and in the chimneys using stainless steel canister and determined by GC/MSD after preconcentration with liquid nitrogen. Benzene, toluene and xylene are the main components among MAHs emitted from coking processes. Benzene and the total MAHs concentrations were as high as 3421.0 microg/m3 and 4 865.9 microg/m3 in the air from indigenous coking, 548.7 microg/m3 and 1 054.8 microg/m3 in the oventop air from industrial coking, and 1 376.4 microg/m3 and 1 819.4 microg/m3 in stack gas from industrial coking, respectively. The MAHs concentrations vary greatly during the indigenous coking process, which in the prophase (from firing to 10 days) is obviously higher than in the anaphase (10 days to quenching the coke). In industrial coking the MAHs in the oventop air are highest when charging the coal and next when transferring the hot coke, but in stack gas they are highest when charging coal and lowest when transferring the coke. Benzene, toluene, ethylbenzene and xylene (BTEX) in industrial coking samples show good linearity, indicating that MAHs in industrial coking might come predominantly from coal pyrolysis; but BTEX distribute dispersedly in indigenous coking samples, indicating that its emission might be affected by many factors. In all samples BTEX ratios especially high B/E ratio, is unique among MAHs sources, and might be helpful to characterize pollution from coking.

  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. Peat fires as source of polycyclic aromatic hydrocarbons in soils

    NASA Astrophysics Data System (ADS)

    Tsibart, Anna

    2013-04-01

    Polycyclic aromatic hydrocarbons (PAHs) arrive from pyrogenic sources including volcanism and the combustion of oil products and plant materials. The production of PAHs during the combustion of plant materials was considered in a number of publications, but their results were mainly obtained in laboratory experiments. Insufficient data are available on the hightemperature production of PAHs in environmental objects. For example, natural fires are frequently related to the PAH sources in landscapes, but very little factual data are available on this topic. On Polistovskii reserve (Russia, Pskov region) the soil series were separated depending on the damage to the plants; these series included soils of plots subjected to fires of different intensities, as well as soils of the background plots. The series of organic and organomineral soils significantly differed in their PAH distributions. In this series, the concentration of PAHs in the upper horizons of the peat soils little varied or slightly decreased, but their accumulation occurred at a depth of 5-10 or 10-20 cm in the soils after the fires. For example, in the series of high moor soils, the content of PAHs in the upper horizons remained almost constant; significant differences were observed in the subsurface horizons: from 2 ng/g in the background soil to 70 ng/g after the fire. In the upper horizons of the oligotrophic peat soils under pine forests, the total PAH content also varied only slightly. At the same time, the content of PAHs in the soil series increased from 15 to 90 ng/g with the increasing pyrogenic damage to the plot. No clear trends of the PAH accumulation were recorded in the organomineral soils. The content of PAHs in the soddy-podzolic soil subjected to fire slightly decreased (from 20 to 10 ng/g) compared to the less damaged soil. In peat fires, the access of oxygen to the fire zone is lower than in forest fires. The oxygen deficit acts as a factor of the organic fragments recombination and

  12. 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.

  13. [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.

  14. 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

  15. 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

  16. 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.

  17. Receptor modeling of source contributions to atmospheric hydrocarbons in urban Kaohsiung, Taiwan

    NASA Astrophysics Data System (ADS)

    Lai, C. H.; Chen, K. S.; Ho, Y. T.; Peng, Y. P.; Chou, Youn-Min

    Data of 60 hydrocarbon species in C 2-C 15 from previous measurements in Kaohsiung (Lai et al., 2004. Atmospheric Environment 38, 1997-2011) were analyzed by applying a chemical mass balance receptor model to determine the major source contributions to atmospheric hydrocarbons. Five major source groups were identified using factor analysis, and 11 source profiles were selected based on sensitivity test results to yield best model performance. Chemical mass balance (CMB) receptor model analyses show that motor vehicle exhaust is the primary source of ambient hydrocarbons during the morning (07-10) and evening (18-21) periods corresponding to the rush hours, but drops in the afternoon non-rush-hour (13-16) period. Furthermore, industrial processes and/or organic solvents contribute most to ambient hydrocarbons during non-rush hours. Contributions from boiler combustion and sewage treatment tanks are always minor. Wind direction analyses reveal that a relatively clean sea breeze tends to reduce the afternoon hydrocarbon concentrations below those during any other period of the day.

  18. 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.

  19. 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. PMID:27239691

  20. 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.

  1. 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.

  2. Speciation of non-methane hydrocarbons (NMHCs) from anthropogenic sources in Beirut, Lebanon.

    PubMed

    Salameh, T; Afif, C; Sauvage, S; Borbon, A; Locoge, N

    2014-09-01

    The chemical composition of emissions from the different anthropogenic sources of non-methane hydrocarbons (NMHC) is essential for modeling and source apportionment studies. The speciated profiles of major NMHC sources in Lebanon, including road transport, gasoline vapor, power generation, and solvent use were established. Field sampling have been carried out by canisters in 2012. Around 67 NMHC (C2 to C9) were identified and quantified by using a gas chromatograph equipped with a flame ionization detector. Typical features of the roadway emissions included high percentages of isopentane, butane, toluene, xylenes, ethylene, and ethyne. Gasoline evaporation profiles included high percentage of the C4-C5 saturated hydrocarbons reaching 59 %. The main compounds of the power generator emissions are related to combustion. Toluene and C8-C9 aromatics were the most abundant species in emissions from paint applications. Finally, the impact of the use of region-specific source profile is tackled regarding the implication on air quality. PMID:24833189

  3. 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....

  4. Landscape planning for agricultural nonpoint source pollution reduction I: a geographical allocation framework.

    PubMed

    Diebel, Matthew W; Maxted, Jeffrey T; Nowak, Peter J; Vander Zanden, M Jake

    2008-11-01

    Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin. We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the cumulative aspects of environmental benefits.

  5. 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.

  6. 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).

  7. 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. PMID:27101457

  8. 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.

  9. 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.

  10. Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay.

    PubMed

    Ziyaadini, Morteza; Mehdinia, Ali; Khaleghi, Leila; Nassiri, Mahmoud

    2016-06-15

    The amounts and sources of polycyclic aromatic hydrocarbons (PAHs) and their bioaccumulation factors (BAFs) in the zooplankton community of Chabahar Bay were investigated. The highest amounts of total PAHs (tPAHs) in the water and zooplankton samples were 62.2ngL(-1) and 1478.6ngg(-1) dry weights, in near the Shahid Beheshti Port and desalination, respectively. The greatest amount of BAF (51,780) was obtained in the entry of Bay, and it was related to the phenanthrene accumulation. Using molecular ratio, the results showed that the major input source of PAH compounds in zooplankton of Chabahar Bay was pyrolytic (fuel) source.

  11. 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

  12. Source apportionment of polycyclic aromatic hydrocarbons and their derivatives in indoor air

    SciTech Connect

    Ray, B.; Mitra, S.

    1996-12-31

    The average person spends more than 80% of his time indoors, thus analysis of the sources of airborne pollutants in indoor air is an important issue. In this paper, we use factor analysis and multiple regression to identify and apportion the different sources of select indoor polycyclic aromatic hydrocarbons (PAHs), their derivatives, and nicotine in indoor air, using data gathered in eight homes in Columbus, OH during the winter of 1986/1987. These homes had different indoor PAH sources, namely, environmental tobacco smoke, gas cooking/heating, and electrical cooking stoves. We find that, of all the sources, environmental tobacco smoke appears to have the greatest impact on the total indoor PAH concentrations. In smokers` homes, more than 87% of the total PAH is due to this source. Background sources are the largest contributor to PAHs in nonsmokers` homes. Very little PAH can be attributed to gas or electric appliances in the home. 16 refs., 3 tabs.

  13. Central graben (Norway) - Hydrocarbon distribution related to source rock maturation and pressure regimes

    SciTech Connect

    Chiarelli, A.; Issard, F. )

    1990-05-01

    This study of the Central graben was limited to the north by 57{degree}25'N, to the west by 4{degree}30', and to the east and south by the borders of the United Kingdom and Denmark, respectively. Several fields have been discovered within the Upper Cretaceous, Paleocene, and Jurassic strata for which the source rocks are Jurassic age. The amount and types of hydrocarbons generated from the source rocks have been estimated by accounting for their thickness, their initial potential, and their degree of maturation. The possibilities for hydrocarbon migration have been interpreted through an integration of the structural history and the hydrodynamic framework within the Central graben region. The hydrodynamic framework which appears to be a very important parameter in the study area, has been reconstructed from pressure measurements in the reservoirs, compaction profiles, and numerical modeling. It appears that vertical migration from the Jurassic source rocks toward the Upper Cretaceous and Paleocene reservoirs was mainly dependent on tectonics, salt diapirism and geopressuring. In the Central graben region the understanding of areal distribution and nature of hydrocarbons formed has been greatly improved by the integration of geochemistry and hydrodynamics. This conclusion could be extended to many other sedimentary basins in the world.

  14. 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

  15. 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

  16. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Parinos, C.; Gogou, A.; Bouloubassi, I.; Pedrosa-Pàmies, R.; Hatzianestis, I.; Sanchez-Vidal, A.; Rousakis, G.; Velaoras, D.; Krokos, G.; Lykousis, V.

    2013-09-01

    Surface sediments collected from deep basins (1018-4087 m depth) of the eastern Mediterranean Sea (Ionian Sea, southern Aegean Sea and northwestern Levantine Sea) were analyzed for aliphatic and polycyclic aromatic hydrocarbons as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons, n-alkanes and the unresolved complex mixture (UCM) of aliphatic hydrocarbons varied significantly, ranging from 1.34 to 49.2 μg g-1, 145 to 4810 ng g-1 and 0.73 to 36.7 μg g-1, respectively, while concentrations of total polycyclic aromatic hydrocarbons (PAHs) ranged between 11.6 and 223 ng g-1. Molecular profiles of determined hydrocarbons reflect a mixed contribution from both natural and anthropogenic sources in deep-sea sediments of the eastern Mediterranean Sea, i.e., terrestrial plant waxes, degraded petroleum products, unburned fossil fuels and combustion of grass, wood and coal. Hydrocarbon mixtures display significant variability amongst sub-regions, reflecting differences in the relative importance of inputs from various sources and phase associations/transport pathways of individual hydrocarbons that impact on their overall distribution and fate. Hydrocarbon concentrations correlated significantly with the organic carbon content of sediments, indicating that the latter exerts an important control on their transport and ultimate accumulation in deep basins. Additionally, water masses' circulation characteristics also seem to influence the regional features and distribution patterns of hydrocarbons. Our findings highlight the role of deep basins/canyons as repositories of both natural and anthropogenic chemical species.

  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. [Estimation and allocation of water environmental capacity in nonpoint source polluted river].

    PubMed

    Chen, Ding-jiang; Lü, Jun; Jin, Shu-quan; Shen, Ye-na

    2007-07-01

    Based on the investigation of the application and emission quantities (QAE) of total nitrogen (TN) and total phosphorus (TP) for nonpoint sources in river catchment' s area, included fertilizer applications, livestock and living pollutants emissions, the quantities of TN and TP entered the river were computed by means of export coefficient model in Changle River, southeast China. Self-purification capacities of TN and TP in the reach were also estimated in terms of input-output balance analysis method. According to the provisions of water function planning in the river, the water environment residual capacity (WERC) or the demand for reducing the application and emission (DRAE) of nitrogen and phosphorus in the corresponding catchment were monthly estimated, and WERC and DRAE were respectively allocated among the pollution sources. Results indicated that about 28.8% of TN loads and 51.2% of TP loads could be self-purified respectively in the reach, i. e., purification of 775.9 t a(-1) for TN and 30.9 t a(-1) for TP. Seasonal variations of the self-purification for the pollutants not only resulted from riverine hydrological and ecological conditions, but also affected by the pollution loading. According to the demand of the water quality protection in the reach, about 1581.0 t a(-1) QAE of TN had to reduce in Changle catchment. The maximum demand for the reducing QAE of TN was the fertilizer application (1047.4 t a(-1)), and the highest ratio for the reducing QAE of TN was livestock-poultry breeding (32.4%). There was about 2335.7 t a(-1) WERC for TP in the reach. The largest DRAE of nitrogen was during mid-water season and the least WERC of TP was during higher-water season.

  20. 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. PMID:26428471

  1. Hydrocarbon Source Signatures in Houston, Texas: Influence of the Petrochemical Industry

    SciTech Connect

    Jobson, B Tom T; Berkowitz, Carl M; Kuster, W C; Goldan, P D; Williams, E J; Fesenfeld, F; Apel, Eric; Karl, Thomas G; Lonneman, William A; Riemer, D

    2004-12-22

    Observations of C1-C10 hydrocarbon mixing ratios measured by in-situ instrumentation at the La Porte super site during the TexAQS 2000 field experiment are reported. The La Porte data were compared to a roadway vehicle exhaust signature obtained from canister samples collected in the Houston Washburn tunnel during the same summer to better understand the impact of petrochemical emissions of hydrocarbons at the site. It is shown that the abundance of ethene, propene, 1-butene, C2-C4 alkanes, hexane, cyclohexane, methylcyclohexane, isopropylbenzene, and styrene at La Porte were systematically impacted by petrochemical industry emissions. Coherent power law relationships between frequency distribution widths of hydrocarbon mixing ratios and their local lifetimes clearly identify two major source groups, roadway vehicle emissions and industrial emissions. Distributions of most aromatics and long chain alkanes were consistent with roadway vehicle emissions as the dominant source. Airmass reactivity was generally dominated by C1-C3 aldehydes. Propene and ethene sometimes dominated air mass reactivity with HO loss frequencies often greater than 10 s-1. Ozone mixing ratios near 200 ppbv were observed on two separate occasions and these air masses appear to have been impacted by industrial emissions of alkenes from the Houston Ship Channel. The La Porte data provide evidence of the importance of industrial emissions of ethene and propene on air masses reactivity and ozone formation in Houston.

  2. Controlled-Source Electromagnetic Approaches for Hydrocarbon Exploration and Monitoring on Land

    NASA Astrophysics Data System (ADS)

    Streich, Rita

    2016-01-01

    Electromagnetic methods that utilize controlled sources have been applied for natural resource exploration for more than a century. Nevertheless, concomitant with the recent adoption of marine controlled-source electromagnetics (CSEM) by the hydrocarbon industry, the overall usefulness of CSEM methods on land has been questioned within the industry. Truly, there are few published examples of land CSEM surveys carried out completely analogously to the current marine CSEM standard approach of towing a bipole source across an array of stationary receivers, continuously transmitting a low-frequency signal and interpreting the data in the frequency domain. Rather, different sensitivity properties of different exploration targets in diverse geological settings, gradual advances in theoretical understanding, acquisition and computer technology, and different schools in different parts of the world have resulted in a sometimes confusing multitude of land-based controlled-source EM surveying approaches. Here, I aim to review previous and present-day approaches, and provide reasoning for their diversity. I focus on surface-based techniques while excluding airborne EM and well logging and on applications for hydrocarbon exploration. Attempts at the very demanding task of using onshore controlled-source EM for reservoir monitoring are shown, and the possible future potential of EM monitoring is discussed.

  3. 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

  4. 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).

  5. 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.

  6. 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.

  7. 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.

  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. 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

  10. 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. PMID:17058015

  11. 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. PMID:18403008

  12. 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.

  13. 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.

  14. 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

  15. Harmonic allocation of authorship credit: source-level correction of bibliometric bias assures accurate publication and citation analysis.

    PubMed

    Hagen, Nils T

    2008-01-01

    Authorship credit for multi-authored scientific publications is routinely allocated either by issuing full publication credit repeatedly to all coauthors, or by dividing one credit equally among all coauthors. The ensuing inflationary and equalizing biases distort derived bibliometric measures of merit by systematically benefiting secondary authors at the expense of primary authors. Here I show how harmonic counting, which allocates credit according to authorship rank and the number of coauthors, provides simultaneous source-level correction for both biases as well as accommodating further decoding of byline information. I also demonstrate large and erratic effects of counting bias on the original h-index, and show how the harmonic version of the h-index provides unbiased bibliometric ranking of scientific merit while retaining the original's essential simplicity, transparency and intended fairness. Harmonic decoding of byline information resolves the conundrum of authorship credit allocation by providing a simple recipe for source-level correction of inflationary and equalizing bias. Harmonic counting could also offer unrivalled accuracy in automated assessments of scientific productivity, impact and achievement.

  16. 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. PMID:25310884

  17. 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

  18. Polycyclic aromatic hydrocarbons in the dagang oilfield (china): distribution, sources, and risk assessment.

    PubMed

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

    2015-06-01

    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

  19. Restoration and source identification of polycyclic aromatic hydrocarbons after the Wu Yi San oil spill, Korea.

    PubMed

    Jang, Yu Lee; Lee, Hyo Jin; Jeong, He Jin; Park, Shin Yeong; Yang, Won Ho; Kim, Heung-Yun; Kim, Gi Beum

    2016-10-15

    On January 31, 2014, an oil spill accident occurred in Yeosu, South Korea. A total 800-899kl of oil from the pipeline was spilled into the sea. After the oil spill, the KIOST (Korea Institute of Ocean Science & Technology) researched PAHs (polycyclic aromatic hydrocarbons) in various media, but sedimentary PAHs were not analyzed despite their longer persistency than in other media. Therefore, this study examined PAH levels in intertidal sediments around Gwangyang Bay and identified PAH sources using oil fingerprinting. PAH residual levels showed a dramatic decrease during the four months after the accident and then remained at a relatively constant level. Analysis through regression equations indicate that this study area is likely to be restored to the PAH levels prior to the accident. Furthermore, the source analysis and oil fingerprinting analysis showed that PAH contamination in this study was unlikely to have originated from the spilled oil.

  20. 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

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

    PubMed

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

    2003-04-01

    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

  2. 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

  3. 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%).

  4. 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.

  5. Effect of Polycyclic Aromatic Hydrocarbon Source Materials and Soil Components on Partitioning and Dermal Uptake.

    PubMed

    Xia, Huan; Gomez-Eyles, Jose L; Ghosh, Upal

    2016-04-01

    The bioavailability of polycyclic aromatic hydrocarbons (PAHs) in soils can be influenced by the source material they are emitted within, the properties of the receiving soil, weathering processes, and the concentration of PAHs. In this study 30 contaminated soils were constructed with common PAH sources (fuel oil, soot, coal tar based skeet particles) and direct spike with a solvent added to different types and contents of soil organic matter and minerals to achieve PAH concentrations spanning 4 orders of magnitude. Source material had the greatest impact on PAH partitioning. Soils containing skeet generally exhibited the highest KD values, followed by soot, fuel oil, and solvent spiked soils. Among all soil compositions, the presence of 2% charcoal had the largest enhancement of KD. Partitioning behavior could not be predicted by an organic carbon and black carbon partitioning model. Including independently measured partitioning behavior of the soil components and PAH sources allowed better prediction but still suffered from issues of interaction (oil sorption in peat) and highly nonlinear partitioning with depletion (for skeet). Dermal absorption of PAHs measured using pig skin was directly related to the freely dissolved aqueous concentration in soil and not the total concentration in the soil. Overall, we show that PAH source materials have a dominating influence on partitioning, highlighting the importance of using native field soils in bioavailability and risk assessments. PMID:26964018

  6. Source contributions of Polycyclic Aromatic Hydrocarbons in soils around oilfield in the Brahmaputra Valley.

    PubMed

    Deka, Jinu; Sarma, Kali Prasad; Hoque, Raza Rafiqul

    2016-11-01

    Surface soils from Borholla oilfield in the upper Brahmaputra Valley in India were studied for the USEPA's 16 priority Polycyclic Aromatic Hydrocarbons (PAHs). Analysis of PAHs was carried out by high performance liquid chromatography (HPLC) system equipped with an UV detector. Seasonality in PAHs concentrations was evident and the concentrations were found to be greater in post-monsoon season. There has been a dominance of low molecular weight PAHs (80-90% of total PAHs) indicating recent deposition from combustion sources. The concentration profiles appeared in the decreasing order of 3-ring >2-ring >4-ring >5-ring >6 ring PAHs. The sources of PAHs were identified using isomer pair ratios and Principal Component Analysis-Multiple Linear Regression (PCA-MLR) and Positive Matrix Factorisation (PMF). The ratios of diagnostic pairs indicated for both pyrogenic and petrogenic input of PAHs. The PCA-MLR modelling revealed that the <16% of contribution came from petrogenic origin and the rest 85% was found to be from pyrogenic sources. The PMF model also shown that <19% of PAHs source were petrogenic origin whereas rest from pyrogenic origin. The correlations of black carbon (BC) with PAHs also supported the pyrogenic contribution. The analysis of air mass back trajectories revealed that there has been contribution of both local and distant sources, through long range transport of pollutants, which were deposited to the site. PMID:27479772

  7. 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. PMID:27172982

  8. 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.

  9. Abdominal fat reducing outcome of exercise training: fat burning or hydrocarbon source redistribution?

    PubMed

    Kuo, Chia-Hua; Harris, M Brennan

    2016-07-01

    Fat burning, defined by fatty acid oxidation into carbon dioxide, is the most described hypothesis to explain the actual abdominal fat reducing outcome of exercise training. This hypothesis is strengthened by evidence of increased whole-body lipolysis during exercise. As a result, aerobic training is widely recommended for obesity management. This intuition raises several paradoxes: first, both aerobic and resistance exercise training do not actually elevate 24 h fat oxidation, according to data from chamber-based indirect calorimetry. Second, anaerobic high-intensity intermittent training produces greater abdominal fat reduction than continuous aerobic training at similar amounts of energy expenditure. Third, significant body fat reduction in athletes occurs when oxygen supply decreases to inhibit fat burning during altitude-induced hypoxia exposure at the same training volume. Lack of oxygen increases post-meal blood distribution to human skeletal muscle, suggesting that shifting the postprandial hydrocarbons towards skeletal muscle away from adipose tissue might be more important than fat burning in decreasing abdominal fat. Creating a negative energy balance in fat cells due to competition of skeletal muscle for circulating hydrocarbon sources may be a better model to explain the abdominal fat reducing outcome of exercise than the fat-burning model.

  10. 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

  11. 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

  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. Applications of biomarkers for identifying sources of natural and pollutant hydrocarbons in the marine environment

    SciTech Connect

    Volkman, J.K.; Revill, A.T.

    1996-12-31

    Over the past few years, many thousands of compounds have identified in crude oils using techniques such as capillary gas chromatography-mass spectrometry (GC-MS). Some of these have quite distinctive chemical structures which are closely related to the organic compounds produced by plants, bacteria and algae. These {open_quote}biomarkers{close_quote} have proven to be very useful in petroleum exploration for identifying the likely source rocks from which the oils were derived. They are also very useful in studies of modern day pollution of the marine environment for identifying contamination by crude oil and petroleum-derived products. Although a wide range of hydrocarbons are available for oil spill fingerprinting, most attention has been given to some of the better-studied biomarkers which are readily analyzed using selected ion monitoring GC-MS techniques.

  14. 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.

  15. 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.

  16. 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, 2012 CFR

    2012-04-01

    ...) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Income from Sources Without the United States § 1.904(g)-3 Ordering rules for the allocation of net operating losses, net capital losses, U.S. source losses... operating losses, net capital losses, U.S. source losses, and separate limitation losses, and for...

  17. 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.

  18. Polycyclic aromatic hydrocarbons in urban street dust and surface soil: comparisons of concentration, profile, and source.

    PubMed

    Wang, De-Gao; Yang, Meng; Jia, Hong-Liang; Zhou, Lei; Li, Yi-Fan

    2009-02-01

    Street dust and surface soil samples in urban areas of Dalian, a coastal city in Liaoning Province, China, were collected and analyzed for 25 polycyclic aromatic hydrocarbons (PAHs). The concentrations, distribution, and sources of PAHs in dust and soil were determined. The concentrations of total PAHs in street dust ranged between 1890 and 17,070 ng/g (dry weight), with an average of 7460 ng/g, whereas the concentrations of total PAHs in surface soil varied greatly, from 650 to 28,900 ng/g, with a mean value of 6440 ng/g. Statistical paired t-test confirmed that total PAH concentrations have no significant difference between street dust and surface soil. Mean PAH concentrations in two type samples were much higher at industrial sites than at business/residential or garden sites. PAHs were dominated by higher molecular weight PAH (4- to 6-ring) homologues, which accounted for about 73% and 72% of total PAHs in street dust and surface soil, respectively. Principal component analysis was used in source apportionment of PAHs in dust and soil. Pyrogenic and petrogenic sources contributed 70% and 22.4% of total PAHs in street dusts, and fossil fuel (coal and petroleum) and biomass combustion accounted for 64.4% and 5.6% of total PAHs in pyrogenic sources, respectively. In surface soil, total PAHs were dominated by pyrogenic sources. The diagnostic ratios of benz[a]anthracene/chrysene confirmed that PAHs in street dust and surface soil of a Dalian urban zone might come mostly from the emission of local sources.

  19. Sources and Deposition of Polycyclic Aromatic Hydrocarbons to Western U.S. National Parks

    PubMed Central

    USENKO, SASCHA; MASSEY SIMONICH, STACI L.; HAGEMAN, KIMBERLY J.; SCHRLAU, JILL E.; GEISER, LINDA; CAMPBELL, DON H.; APPLEBY, PETER G.; LANDERS, DIXON H.

    2010-01-01

    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) in order 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 210Pb and 137Cs. The fourteen remote lake catchments ranged from low-latitude catchments (36.6° N) at high elevation (2900 masl) in Sequoia National Park, CA to high-latitude catchments (68.4° N) at low elevation (427 masl) in the Alaskan Arctic. Over 75% of the catchments demonstrated statistically significant temporal trends in ΣPAH sediment flux, depending on catchment proximity to source regions and topographic barriers. The ΣPAH 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. PMID:20465303

  20. 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. PMID:22606062

  1. Concentrations and sources of polycyclic aromatic hydrocarbons in indoor dust in China.

    PubMed

    Qi, Hong; Li, Wen-Long; Zhu, Ning-Zheng; Ma, Wan-Li; Liu, Li-Yan; Zhang, Feng; Li, Yi-Fan

    2014-09-01

    Indoor dust samples were collected across China in the winter of 2010 from 45 private domiciles and 36 public buildings. 16 polycyclic aromatic hydrocarbons (PAHs) were determined by GC-MS. Total concentrations of PAHs ranged from 1.00 μg/g to 470 μg/g with a mean value of 30.9 μg/g. High-molecular weight (HMW) PAHs (4 to 6 rings) are the predominant PAHs found in indoor dust, accounting for 68% of the total PAH concentration in private domiciles, and 84.6% in public buildings. Traffic conditions and cooking methods were the two key factors controlling PAH levels, especially for coal combustion and vehicular traffic emission sources. A significant positive correlation was observed between PAH concentrations in indoor dust and based on location (latitude and longitude). The latitudinal distribution indicated a higher usage of coal for heating in Northern China than in Southern China. The longitudinal distribution indicated that the usage of oil and mineral fuels as well as economic development and population density increased from West China to East China. In addition, diagnostic ratios and principal component analysis (PCA) were used to explore source apportion, as indicated in both the pyrogenic and petrogenic sources of PAHs in indoor dust in China. Furthermore, the BaP equivalent was applied to assess the carcinogenic risk of PAHs, which also indicated that traffic emissions and coal combustion were the two major contributions to carcinogenic risk of PAHs in indoor dust in China.

  2. 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.

  3. 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.

  4. Polycyclic aromatic hydrocarbons (PAHs) in sea sediments of the Turkish Mediterranean coast, composition and sources.

    PubMed

    Tuncel, Semra G; Topal, Tansel

    2015-03-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in 25 surface sediment samples from five sites located at Oludeniz Lagoon of the Turkish Mediterranean coast. The total concentration of the PAHs (1.85 ± 1.39 mg/kg) was lower than the sediments from highly urbanized areas, while it was comparable with the sediments from similar locations. Acenaphthene and chrysene were dominant ones with the concentrations of 0.620 and 0.515 mg/kg, respectively. The isomeric ratios indicated that combustion is the predominant source of PAHs in the sediments. Factor analysis solution supports the same finding with three major factors accounting for 71.7% of the variability in the data. Factor 1 with 43.4% of the total variance identified as a pyrogenic source (coal combustion; 4 rings PAH and traffic related pollution; 5-6 rings PAHs). Factor 2 (explains 39% of the total variance) represents PAHs originating from traffic, and factor 3 (explains 12% of the total variance) represents petrogenic source. Our results suggest that combustion of fossil fuels affects most of the points, followed by combustion of biomass and human activity. PMID:25280504

  5. Sources and risk of polycyclic aromatic hydrocarbons in Baiyangdian Lake, North China.

    PubMed

    Liu, Xinhui; Xu, Mingzhu; Yang, Zhifeng; Sun, Tao; Cui, Baoshan; Wang, Liang; Wu, Dan

    2010-01-01

    The 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in the surface sediments and water of Baiyangdian (BYD) Lake. Total concentration of the 16 PAHs (summation operator 16PAHs) ranges from 229.85 to 1,750.04 microg kg(-1) dry weight for the surface sediments, and varies between 145.10 and 1,311.59 ng l(-1) for the surface water. The PAHs level of BYD Lake is around the midpoint of the global PAHs concentration range. Sources of PAHs in surface sediments were identified by three levels of source identification analysis, which include composition analysis (CA), isomer ratios (IR) and principle component analysis/multiple linear regression (PCA/MLR). Three sources namely coke/coal combustion, diesel emission and vehicle emission were dominant. Their corresponding contributions were 64%, 21% and 15%, respectively. Toxic potency of carcinogenic PAHs in the sediment presents a good relationship with benzo(a)pyrene levels, which indicates benzo(a)pyrene is a good indicator for assessing the potential toxicity of carcinogenic PAHs. The results of risk assessment show that most of the PAHs may not pose unfavourable effects on the aquatic ecosystem. However, it is worthy noting that some of them may exert adverse biological effects.

  6. Sources and risk of polycyclic aromatic hydrocarbons in Baiyangdian Lake, North China.

    PubMed

    Liu, Xinhui; Xu, Mingzhu; Yang, Zhifeng; Sun, Tao; Cui, Baoshan; Wang, Liang; Wu, Dan

    2010-01-01

    The 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in the surface sediments and water of Baiyangdian (BYD) Lake. Total concentration of the 16 PAHs (summation operator 16PAHs) ranges from 229.85 to 1,750.04 microg kg(-1) dry weight for the surface sediments, and varies between 145.10 and 1,311.59 ng l(-1) for the surface water. The PAHs level of BYD Lake is around the midpoint of the global PAHs concentration range. Sources of PAHs in surface sediments were identified by three levels of source identification analysis, which include composition analysis (CA), isomer ratios (IR) and principle component analysis/multiple linear regression (PCA/MLR). Three sources namely coke/coal combustion, diesel emission and vehicle emission were dominant. Their corresponding contributions were 64%, 21% and 15%, respectively. Toxic potency of carcinogenic PAHs in the sediment presents a good relationship with benzo(a)pyrene levels, which indicates benzo(a)pyrene is a good indicator for assessing the potential toxicity of carcinogenic PAHs. The results of risk assessment show that most of the PAHs may not pose unfavourable effects on the aquatic ecosystem. However, it is worthy noting that some of them may exert adverse biological effects. PMID:20390886

  7. 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

  8. 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.

  9. 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. PMID:11516134

  10. 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

  11. Distributions and sources of petroleum, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Bohai Bay and its adjacent river, China.

    PubMed

    Wang, Min; Wang, Chuanyuan; Hu, Xiaoke; Zhang, Haijiang; He, Shijie; Lv, Shuangyan

    2015-01-15

    Surface sediment samples from Bohai Bay and its adjacent river, China, were analyzed for aliphatic hydrocarbon, PAHs and biomarkers in order to determine the distribution, composition and source of organic matter in a coastal environment. Results suggested that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Petroleum contamination, mainly from offshore oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. PAHs were mostly of pyrogenic origin; while some sites in Yellow River Estuary were derived mainly from the petrogenic sources. The toxic assessment suggested that the PAHs in surface sediments will not cause immediately adverse biological effects in sediments from Bohai Bay and its adjacent river, China. PMID:25499964

  12. Distributions and sources of petroleum, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Bohai Bay and its adjacent river, China.

    PubMed

    Wang, Min; Wang, Chuanyuan; Hu, Xiaoke; Zhang, Haijiang; He, Shijie; Lv, Shuangyan

    2015-01-15

    Surface sediment samples from Bohai Bay and its adjacent river, China, were analyzed for aliphatic hydrocarbon, PAHs and biomarkers in order to determine the distribution, composition and source of organic matter in a coastal environment. Results suggested that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Petroleum contamination, mainly from offshore oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. PAHs were mostly of pyrogenic origin; while some sites in Yellow River Estuary were derived mainly from the petrogenic sources. The toxic assessment suggested that the PAHs in surface sediments will not cause immediately adverse biological effects in sediments from Bohai Bay and its adjacent river, China.

  13. 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.

  14. Analysis of persistent halogenated hydrocarbons in fish feeds containing fish oil and other alternative lipid sources.

    PubMed

    You, Jing; Kelley, Rebecca A; Crouse, Curtis C; Trushenski, Jesse T; Lydy, Michael J

    2011-09-15

    A trade-off exists between beneficial n-3 long-chain polyunsaturated acids and toxic persistent halogenated hydrocarbons (PHHs), both of which primarily originate from fish oil commonly used in fish feeds. Alternative lipid sources are being investigated for use in fish feeds to reduce harmful contaminant accumulation, hence, research is needed to evaluate PHHs in fish feeds with various lipid compositions. An analytical method was developed for PHHs including nine organochlorine insecticides (OCPs), 26 polychlorinated biphenyls (PCBs) and seven polybrominated diphenyl ethers (PBDEs) in fish feeds with differing proportions of fish oils and alternative lipid sources by GC-ECD after accelerated solvent extraction, gel permeation chromatography (GPC), and sulfuric acid cleanup. The GPC removed the majority of the neutral lipids and sulfuric acid treatment effectively destroyed the polar lipids. Thus, the combination of the two methods removed approximately 99.7% of the lipids in the extracts. The method detection limits were less than 5 ng/g dry weight (dw) for most PHHs, while recoveries were 75-118%, 67-105%, 69-92%, 63-100% and 94-144% with relative standard deviations of 0.2-39%, 0.3-20%, 0.5-12%, 1.5-18% and 1.5-15% for PHHs in five types of fish feeds made from different lipid sources. Although the source of lipid showed no impact on cleanup efficiency and the developed method worked well for all feeds, fish feeds with 100% fish oil contained background PHHs and more interference than feeds containing alternative lipids.

  15. [Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in urban rainfall runoff].

    PubMed

    Wu, Zi-Lan; Yang, Yi; Liu, Min; Lu, Min; Yu, Ying-Peng; Wang, Qing; Zheng, Xin

    2014-11-01

    Runoff samples were collected from traffic roads, campus, residential road and roof in a typical rain event. Polycyclic aromatic hydrocarbons (PAHs) in both dissolved and particle phases were investigated at impervious surfaces. The PAHs wash-off process at different monitoring sites was analyzed. The scatters of first flush were conducted in a method of fitting power function to quantitatively assess the magnitude of first flush effect (FFE). The sources of PAHs were identified using factor analysis. The results showed that PAHs concentrations in runoff samples varied from 317.21 ng x L(-1) to 10364.3 ng x L(-1) with the maximal and minimal contents of PAHs found on Longwu Road and campus, respectively. The values of event mean concentration ( EMC) varied considerably at different sampling sites. The concentration of washed-off pollutant generally decreased with runoff duration, which showed an obvious attenuation trend. The runoff process indicated the occurrence of FFE at different levels. PAHs mainly came from the incomplete combustion of fossil fuels, oil leakage and coking, and the contribution of each source was different in accordance with various surfaces. PMID:25639088

  16. Source apportionment of polycyclic aromatic hydrocarbons in the Dahuofang Reservoir, Northeast China.

    PubMed

    Lin, Tian; Qin, Yanwen; Zheng, Binghui; Li, Yuanyuan; Chen, Ying; Guo, Zhigang

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) in 24 surface sediments from the Dahuofang Reservoir (DHF), the largest man-made lake in Northeast China, were measured. The results showed that the concentrations of 16 US EPA priority PAHs in the sediments ranged from 323 to 912 ng/g dry weight with a mean concentration of 592 ± 139 ng/g. The PAH source contributions were estimated based on positive matrix factorization model. The coal combustion contributed to 31 % of the measured PAHs, followed by residential emissions (22%), biomass burning (21%), and traffic-related emissions (10%). Pyrogenic sources contributed ~84% of anthropogenic PAHs to the sediments, indicating that energy consumption release was a predominant contribution of PAH pollution in DHF. Compared with the results from the urban atmospheric PAHs in the region, there was a low contribution from traffic-related emissions in the sediments possibly due to the low mobility of the traffic-related derived 5+6-ring PAHs and their rapid deposition close to the urban area. PMID:22454050

  17. 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

  18. Sources of heavy metals and polycyclic aromatic hydrocarbons in urban stormwater runoff.

    PubMed

    Brown, Jeffrey N; Peake, Barrie M

    2006-04-15

    Polycyclic aromatic hydrocarbons (PAHs) and heavy metals were measured in road debris collecting in urban areas and in the suspended sediment (SS) component of runoff from two stormwater catchments in Dunedin, New Zealand. Levels in the road debris ranged from 119-527 microg/g for lead, 50-464 microg/g for copper, 241-1 325 microg/g for zinc and 1.20-11.6 microg/g for sigma16PAH. The SS from the largely rural catchment (20% urban) had similar concentrations to the road debris, indicating that this urban material was the main source of the contaminants measured in the stormwater. Similar PAH fingerprint profiles and isomer ratios indicative of dominant pyrogenic (combustion) sources were also found in these two groups of materials. The SS from the 100% urban catchment contained 2- to 6-fold higher concentrations of metals and 10-fold greater levels of sigma16PAH. The higher levels of lead and copper were probably a result of industrial land uses in this catchment, while the additional zinc was linked to an abundance of zinc-galvanised roofing iron in the catchment's residential suburbs. The PAH profiles and isomer ratios were different for this urban catchment and suggested that a disused gasworks was contributing PAHs to the stormwater runoff. PMID:16014309

  19. 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.

  20. Distributions, Sources, and Backward Trajectories of Atmospheric Polycyclic Aromatic Hydrocarbons at Lake Small Baiyangdian, Northern China

    PubMed Central

    Qin, Ning; Kong, Xiang-Zhen; Zhu, Ying; He, Wei; He, Qi-Shuang; Yang, Bin; Ou-Yang, Hui-Ling; Liu, Wen-Xiu; Wang, Qing-Mei; Xu, Fu-Liu

    2012-01-01

    Air samples were collected seasonally at Lake Small Baiyangdian, a shallow lake in northern China, between October 2007 and September 2008. Gas phase, particulate phase and dust fall concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured using a gas chromatograph-mass spectrometer (GC-MS). The distribution and partitioning of atmospheric PAHs were studied, and the major sources were identified; the backward trajectories of air masses starting from the center of Lake Small Baiyangdian were calculated for the entire year. The following results were obtained: (1) The total concentration of 16 priority controlled PAHs (PAH16) in the gas phase was 417.2 ± 299.8 ng·m−3, in the particulate phase was 150.9 ± 99.2 ng·m−3, and in dust fall was 6930.2 ± 3206.5 ng·g−1. (2) Vehicle emission, coal combustion, and biomass combustion were the major sources in the Small Baiyangdian atmosphere and accounted for 28.9%, 45.1% and 26.0% of the total PAHs, respectively. (3) Winter was dominated by relatively greater PAHs polluted northwesterly air mass pathways. Summer showed a dominant relatively clean southern pathway, whereas the trajectories in autumn and spring might be associated with high pollution from Shanxi or Henan province. PMID:23118612

  1. 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.

  2. [Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in urban rainfall runoff].

    PubMed

    Wu, Zi-Lan; Yang, Yi; Liu, Min; Lu, Min; Yu, Ying-Peng; Wang, Qing; Zheng, Xin

    2014-11-01

    Runoff samples were collected from traffic roads, campus, residential road and roof in a typical rain event. Polycyclic aromatic hydrocarbons (PAHs) in both dissolved and particle phases were investigated at impervious surfaces. The PAHs wash-off process at different monitoring sites was analyzed. The scatters of first flush were conducted in a method of fitting power function to quantitatively assess the magnitude of first flush effect (FFE). The sources of PAHs were identified using factor analysis. The results showed that PAHs concentrations in runoff samples varied from 317.21 ng x L(-1) to 10364.3 ng x L(-1) with the maximal and minimal contents of PAHs found on Longwu Road and campus, respectively. The values of event mean concentration ( EMC) varied considerably at different sampling sites. The concentration of washed-off pollutant generally decreased with runoff duration, which showed an obvious attenuation trend. The runoff process indicated the occurrence of FFE at different levels. PAHs mainly came from the incomplete combustion of fossil fuels, oil leakage and coking, and the contribution of each source was different in accordance with various surfaces.

  3. Source identification of Malaysian atmospheric polycyclic aromatic hydrocarbons nearby forest fires using molecular and isotopic compositions

    NASA Astrophysics Data System (ADS)

    Okuda, Tomoaki; Kumata, Hidetoshi; Zakaria, Mohamad Pauzi; Naraoka, Hiroshi; Ishiwatari, Ryoshi; Takada, Hideshige

    We report measurements of molecular and carbon isotopic compositions of Malaysian atmospheric polycyclic aromatic hydrocarbons (PAHs) in smoke haze from the 1997 Indonesian forest fire. Comparison of the carbon isotopic compositions ( δ13C) of individual PAHs from the smoke haze, with those from other PAHs sources (soot collected from gasoline and diesel vehicle muffler, woodburning smoke), enables us to discriminate among the diverse sources of atmospheric PAHs. Soot PAHs extracted from gasoline and diesel vehicles show heavy isotopic signatures with a large inter-species δ13C variation from -12.9‰ to -26.6‰, compared to soot PAHs extracted from woodburning smoke which are isotopically light, and have a small inter-species δ13C variation from -26.8‰ to -31.6‰. Values from -17.7‰ to -27.9‰ were obtained for the corresponding PAHs extracted from the smoke haze, indicating that they are derived mainly from automotive exhaust. Molecular and isotopic compositions of PAHs extracted from smoke haze were similar to those extracted from non-haze aerosol. Quantitative estimation shows that woodburning contribution to Malaysian atmospheric PAHs ranges from 25% to 35% with no relation to haze intensity, while automotive contribution ranges from 65% to 75%. These results suggest that the major contributor of PAHs in Malaysian air is automotive exhaust whether smoke haze is observed or not.

  4. Deep-sea hydrocarbon seep communities: evidence for energy and nutritional carbon sources

    SciTech Connect

    Brooks, J.M.; Kennicutt, M.C. II; Fisher, C.R.; Macko, S.A.; Cole, K.; Childress, J.J.; Bidigare, R.R.; Vetter, R.D.

    1987-11-20

    Mussels, clams, and tube worms collected in the vicinity of hydrocarbon seeps on the Louisiana slope contain mostly dead carbon, indicating that dietary carbon is largely derived from seeping oil and gas. Enzyme assays, elemental sulfur analysis, and carbon dioxide fixation studies demonstrate that vestimentiferan tube worms and three clam species contain intracellular, autotrophic sulfur bacterial symbionts. Carbon isotopic ratios of 246 individual animal tissues were used to differentiate heterotrophic (delta/sup 14/C = -14 to -20 per mil), sulfur-based (delta/sup 14/C = -30 to -42 per mil), and methane-based (delta/sup 13/C = <-40 per mil) energy sources. Mussels with symbiotic methanotrophic bacteria reflect the carbon isotopic composition of the methane source. Isotopically light nitrogen and sulfur confirm the chemoautotrophic nature of the seep animals. Sulfur-based chemosynthetic animals contain isotopically light sulfur, whereas methane-based symbiotic mussels more closely reflect the heavier oceanic sulfate pool. The nitrogen requirement of some seep animals may be supported by nitrogen-fixing bacteria. Some grazing neogastropods have isotopic values characteristic of chemosynthetic animals, suggesting the transfer of carbon into the background deep-sea fauna.

  5. 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.

  6. Sedimentology and hydrocarbon potential of Yager structural complex--possible paleogene source rocks in Eel River Basin, Northern California

    SciTech Connect

    Underwood, M.B.

    1985-07-01

    The Yager structural complex of coastal northern California is composed of Paleogene mudrocks, turbidites, and related deep marine deposits. The strata are folded but lack the severe and pervasive stratal disruption that characterizes surrounding accreted terranes, such as the Franciscan Coastal belt. Lithofacies associations and depositional cycles define three environmental settings: slope, feeder channel, and restricted basin. The rocks probably represent a sequence of trench-slope and slope-basin deposits that accumulated above a broadly coeval basement of accreted Coastal belt rocks. Yager strata are possible source beds for hydrocarbons within the late Cenozoic Eel River basin. Type III kerogen is dominant, and organic carbon content and hydrocarbon yield are relatively low. Nevertheless, the thermal maturity of Yager shales is well within the window of peak hydrocarbon generation. This level of maturation is attributed to a combination of middle Tertiary thrust faulting and subsequent depositional burial beneath the Neogene Wildcat Group.

  7. 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.

  8. Sources and fate of polycyclic aromatic hydrocarbons in the Antarctic and Southern Ocean atmosphere

    NASA Astrophysics Data System (ADS)

    Cabrerizo, Ana; Galbán-Malagón, Cristóbal; Del Vento, Sabino; Dachs, Jordi

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are a geochemically relevant family of semivolatile compounds originating from fossil fuels, biomass burning, and their incomplete combustion, as well as biogenic sources. Even though PAHs are ubiquitous in the environment, there are no previous studies of their occurrence in the Southern Ocean and Antarctic atmosphere. Here we show the gas and aerosol phase PAHs concentrations obtained from three sampling cruises in the Southern Ocean (Weddell, Bellingshausen, and South Scotia Seas), and two sampling campaigns at Livingston Island (Southern Shetlands). This study shows an important variability of the atmospheric concentrations with higher concentrations in the South Scotia and northern Weddell Seas than in the Bellingshausen Sea. The assessment of the gas-particle partitioning of PAHs suggests that aerosol elemental carbon contribution is modest due to its low concentrations. Over the ocean, the atmospheric concentrations do not show a temperature dependence, which is consistent with an important role of long-range atmospheric transport of PAHs. Conversely, over land at Livingston Island, the PAHs gas phase concentrations increase when the temperature increases, consistently with the presence of local diffusive sources. The use of fugacity samplers allowed the determination of the air-soil and air-snow fugacity ratios of PAHs showing that there is a significant volatilization of lighter molecular weight PAHs from soil and snow during the austral summer. The higher volatilization, observed in correspondence of sites where the organic matter content in soil is higher, suggests that there may be a biogenic source of some PAHs. The volatilization of PAHs from soil and snow is sufficient to support the atmospheric occurrence of PAHs over land but may have a modest regional influence on the atmospheric occurrence of PAHs over the Southern Ocean.

  9. Size- and density-distributions and sources of polycyclic aromatic hydrocarbons in urban road dust.

    PubMed

    Murakami, Michio; Nakajima, Fumiyuki; Furumai, Hiroaki

    2005-11-01

    Polycyclic aromatic hydrocarbons (PAHs) present in size- and density-fractionated road dust were measured to identify the important fractions in urban runoff and to analyse their sources. Road dust was collected from a residential area (Shakujii) and a heavy traffic area (Hongo Street). The sampling of road dust from the residential area was conducted twice in different seasons (autumn and winter). The collected road dust was separated into three or four size-fractions and further fractionated into light (<1.7 g/cm3) and heavy (>1.7 g/cm3) fractions by using cesium chloride solution. Light particles constituted only 4.0+/-1.4%, 0.69+/-0.03% and 3.4+/-1.0% of the road dust by weight for Shakujii (November), Shakujii (February) and Hongo Street, respectively but contained 28+/-10%, 33+/-3% and 44+/-8% of the total PAHs, respectively. The PAH contents in the light fractions were 1-2 orders of magnitude higher than those in the heavy fractions. In the light fractions, the 12PAH contents in February were significantly higher than the 12PAH contents in November (P<0.01), whereas in the heavy fractions, no significant difference was found (P>0.05). Cluster analysis revealed that there was a significant difference in the PAH profiles between locations rather than between size-fractions, density-fractions and sampling times. Multiple regression analysis indicated that asphalt/pavement was the major source of Shakujii road dust, and that tyre and diesel vehicle exhaust were the major sources of finer and coarser fractions collected from Hongo Street road dust, respectively.

  10. 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.

  11. Triacylglyceride Production and Autophagous Responses in Chlamydomonas reinhardtii Depend on Resource Allocation and Carbon Source

    PubMed Central

    Davey, Matthew P.; Horst, Irmtraud; Duong, Giang-Huong; Tomsett, Eleanor V.; Litvinenko, Alexander C. P.; Howe, Christopher J.

    2014-01-01

    To improve the economic viability of microalgal biodiesel, it will be essential to optimize the productivity of fuel molecules such as triacylglyceride (TAG) within the microalgal cell. To understand some of the triggers required for the metabolic switch to TAG production, we studied the effect of the carbon supply (acetate or CO2) in Chlamydomonas reinhardtii (wild type and the starchless sta6 mutant) grown under low N availability. As expected, initial rates of TAG production were much higher when acetate was present than under strictly photosynthetic conditions, particularly for the sta6 mutant, which cannot allocate resources to starch. However, in both strains, TAG production plateaued after a few days in mixotrophic cultures, whereas under autotrophic conditions, TAG levels continued to rise. Moreover, the reduced growth of the sta6 mutant meant that the greatest productivity (measured as mg TAG liter−1 day−1) was found in the wild type growing autotrophically. Wild-type cells responded to low N by autophagy, as shown by degradation of polar (membrane) lipids and loss of photosynthetic pigments, and this was less in cells supplied with acetate. In contrast, little or no autophagy was observed in sta6 mutant cells, regardless of the carbon supply. Instead, very high levels of free fatty acids were observed in the sta6 mutant, suggesting considerable alteration in metabolism. These measurements show the importance of carbon supply and strain selection for lipid productivity. Our findings will be of use for industrial cultivation, where it will be preferable to use fast-growing wild-type strains supplied with gaseous CO2 under autotrophic conditions rather than require an exogenous supply of organic carbon. PMID:24413660

  12. Source characterization of polycyclic aromatic hydrocarbons by using their molecular indices: an overview of possibilities.

    PubMed

    Stogiannidis, Efstathios; Laane, Remi

    2015-01-01

    In recent decades. an exponential increase in the concentration of anthropogenic Polycyclic Aromatic Hydrocarbons (PAHs; see Table I for a li st of PAH abbreviations) has been observed worldwide. Regulators need to know the sources if concentrations are to be reduced and appropriate remediation measures taken. "Source characterization of PAHs" involves linking these contaminants to their sources. Scientists place PAH sources into three classes: pyrogenic, petrogenic. and natural. In this review. we investigate the possibility of using PAH molecular ratios individually or in combination for the purpose of deducing the petrogenic or pyrogenic origin of the contamination in sediments. We do this by reviewing the characteristic PAH patterns of the sources and by taking into account the fate of PAHs in the aquatic environment. Many PAH indicators have been developed for the purpose of discriminating different PAH sources. In Table 4 we summarize the applicability of different PAH ratios and threshold values. The analysis of two- to four-ringed alkylated PAH soilers the possibility to distinguish two or more single sources or categories of pollution in greater detail. For example. the FLO/PYO. the PPI. and PO/AO ratios can be used to discriminate between pyrogenic and petrogcnic sources of contamination. When petrogenic contamination is suspected. chrysenes. PAHs lighter than CO. and in particular. alkylated PAHs can usually be of use. For unburned coal PAHs. The methylphenanthrenic ratios (MP!s). the 1-D I/4- DI. and BbF/BkF are promising, since they are sometimes correlated with vitrinite rellectance (coal ranks). Alkylphenanthrenes can be used to detect biomass combustion. Higher molecular weight parent and alkylated PAHs are appropriate for pyrogenic discriminations. When PAH indices are coupled with discriminant analysis techniques such as PMF (positive matrix factorization),the origin of multiple sources in even the most complex environments can be traced and

  13. Source characterization of polycyclic aromatic hydrocarbons by using their molecular indices: an overview of possibilities.

    PubMed

    Stogiannidis, Efstathios; Laane, Remi

    2015-01-01

    In recent decades. an exponential increase in the concentration of anthropogenic Polycyclic Aromatic Hydrocarbons (PAHs; see Table I for a li st of PAH abbreviations) has been observed worldwide. Regulators need to know the sources if concentrations are to be reduced and appropriate remediation measures taken. "Source characterization of PAHs" involves linking these contaminants to their sources. Scientists place PAH sources into three classes: pyrogenic, petrogenic. and natural. In this review. we investigate the possibility of using PAH molecular ratios individually or in combination for the purpose of deducing the petrogenic or pyrogenic origin of the contamination in sediments. We do this by reviewing the characteristic PAH patterns of the sources and by taking into account the fate of PAHs in the aquatic environment. Many PAH indicators have been developed for the purpose of discriminating different PAH sources. In Table 4 we summarize the applicability of different PAH ratios and threshold values. The analysis of two- to four-ringed alkylated PAH soilers the possibility to distinguish two or more single sources or categories of pollution in greater detail. For example. the FLO/PYO. the PPI. and PO/AO ratios can be used to discriminate between pyrogenic and petrogcnic sources of contamination. When petrogenic contamination is suspected. chrysenes. PAHs lighter than CO. and in particular. alkylated PAHs can usually be of use. For unburned coal PAHs. The methylphenanthrenic ratios (MP!s). the 1-D I/4- DI. and BbF/BkF are promising, since they are sometimes correlated with vitrinite rellectance (coal ranks). Alkylphenanthrenes can be used to detect biomass combustion. Higher molecular weight parent and alkylated PAHs are appropriate for pyrogenic discriminations. When PAH indices are coupled with discriminant analysis techniques such as PMF (positive matrix factorization),the origin of multiple sources in even the most complex environments can be traced and

  14. Gas-Phase Polycyclic Aromatic Hydrocarbons in Absorption toward Protostellar Sources?

    NASA Astrophysics Data System (ADS)

    Bregman, Jesse D.; Temi, Pasquale

    2001-06-01

    One of the major criticisms of identifying the infrared emission bands with polycyclic aromatic hydrocarbon (PAH) molecules has been the lack of a match between laboratory spectra of individual PAHs and the emission features. Part of the difficulty arises from the complexity of modeling the emission mechanism with an a priori unknown mixture of ionized and neutral PAHs. A direct comparison between laboratory spectra of PAHs and astronomical sources is possible for absorption spectra. However, because of poor atmospheric transmission, ground-based spectra of the PAH absorption band in the C-H stretch region are too noisy to make a detailed comparison with laboratory spectra. In this paper we show that ISO Short Wavelength Spectrometer spectra of a few protostars that show a 3.25 μm absorption band can be well matched by laboratory absorption spectra of a mixture of isolated PAHs. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, the Netherlands, and the United Kingdom), with the participation of ISAS and NASA.

  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. Polycyclic aromatic hydrocarbons in dust from computers : one possible indoor source of human exposure

    NASA Astrophysics Data System (ADS)

    Ren, Yu; Cheng, Tiantao; Chen, Jianmin

    Computer is an important part of our usual life and work. The harmful exposure to the radiation of computers has been paid attention broadly. However, chemical pollution related to computers is rarely reported. Here we investigated the levels and sources of EPA 16 priority polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from components and internal walls of computers' boxes (in-computers) in Shanghai, China. Dust samples were collected from 27 computers in different indoor environment: offices, laboratories, and one net bar. The levels of PAHs in dust samples were from 8.22 μg g -1 to 42.04 μg g -1. BbF, BgP, DbA, Chry and BaP were the most abundant PAHs. The levels of PAHs in computers in smoking rooms (mainly in the net bar) were usually 1.35-2.87 times higher than those in nonsmoking rooms, indicating that the indoor environment of different rooms affected the loading of dust PAHs significantly. To study the source of PAHs in computers, six dust samples were collected from windowsills (out-computers) in the corresponding rooms. The results indicated that most PAHs from in-computers were greater than those from out-computers, which indicated that parts of PAHs in computers may be emitted from the heated plastic material out of chips in computers when they are running, and be adsorbed on dust deposited on these components. The potential exposure of PAHs from computers was also evaluated, and our results showed that people maybe exposure particle-phase PAHs up to 2.99 ng m -3 which are just sprayed out with dust from computers.

  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. 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

  19. 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.

  20. 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. PMID:25434473

  1. [Quantities analysis of the infrared diffuse reflection spectrum of hydrocarbon source rocks by OSC-iPLS].

    PubMed

    Song, Ning; Xu, Xiao-Xuan; Wang, Bin; Zhang, Cun-Zhou

    2009-02-01

    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. In order to remove the effects of scattering and noise on multivariate calibration of IR spectral signals, orthogonal signal correction (OSC) was used as a method to preprocess the infrared spectra of the hydrocarbon source rocks to be quantitatively determined, thus to establish the calibration model of hydrocarbon source rocks before and after pretreatment by inetval partial least square (iPLS). Pretreatment was smoother and more orderly array. This indicated that the major information in hydrocarbon source rocks spectra could be reserved while part of noise was removed by OSC method. In this study, pretreatment calibration model was obtained, the model's correlation coefficient is 0.994 04 and RMSE is 0.635 2, but with no pretreatment the calibration model's correlation coefficient is 0.770 9 and RMSE is 3.925 7.

  2. [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.

  3. [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.

  4. [Variation Characteristics and Sources of Polycyclic Aromatic Hydrocarbons in Karst Subterranean River During Rainfall Events].

    PubMed

    Jiang, Ze-li; Sun, Yu-chuan; Wang, Zun-bo; Liang, Zuo-bing; Ren, Kun; Xie, Zheng-lan; Zhang, Mei; Liao, Yu

    2015-11-01

    The water samples were continuously collected at the outlet of Nanshan Laolongdong subterranean river basin, which is located in Chongqing, during the rainfall event in June 2014. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) in water were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The objectives of this study were to reveal the variation characteristics and sources of PAH16 in karst subterranean river during the rainfall event. The results showed that the subterranean river responded promptly to the rainfall, and there were four peaks of the total concentrations of PAH16, two peaks occurred during the flow rise stage, the others were in the maximum flow and flow decline stages. The total concentrations of PAH16 ranged 101-3 624 ng x L(-1), with a mean of 578 ng x L(-1), the total concentrations of 7 carcinogenic PAHs ranged ND-336 ng x L(-1), with a mean of 31.1 ng x L(-1). The PAH compositional profiles were dominated by 2,3-ring compounds, which accounted for 86.17% of the total concentrations of PAH16. The total concentrations of PAH16 were most influenced by the rainfall, through the cleaning of atmospheric pollutants by the rain and the scouring of the surface contaminants by the rainfall runoff. The PAHs in water mainly originated from the incomplete combustion of petroleum products and fossil fuels such as coal, as well as natural digenetic process. Compared to other areas in the world, the concentrations of PAH16 were generally at moderately polluted and heavily polluted levels. PMID:26910994

  5. [Variation Characteristics and Sources of Polycyclic Aromatic Hydrocarbons in Karst Subterranean River During Rainfall Events].

    PubMed

    Jiang, Ze-li; Sun, Yu-chuan; Wang, Zun-bo; Liang, Zuo-bing; Ren, Kun; Xie, Zheng-lan; Zhang, Mei; Liao, Yu

    2015-11-01

    The water samples were continuously collected at the outlet of Nanshan Laolongdong subterranean river basin, which is located in Chongqing, during the rainfall event in June 2014. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) in water were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The objectives of this study were to reveal the variation characteristics and sources of PAH16 in karst subterranean river during the rainfall event. The results showed that the subterranean river responded promptly to the rainfall, and there were four peaks of the total concentrations of PAH16, two peaks occurred during the flow rise stage, the others were in the maximum flow and flow decline stages. The total concentrations of PAH16 ranged 101-3 624 ng x L(-1), with a mean of 578 ng x L(-1), the total concentrations of 7 carcinogenic PAHs ranged ND-336 ng x L(-1), with a mean of 31.1 ng x L(-1). The PAH compositional profiles were dominated by 2,3-ring compounds, which accounted for 86.17% of the total concentrations of PAH16. The total concentrations of PAH16 were most influenced by the rainfall, through the cleaning of atmospheric pollutants by the rain and the scouring of the surface contaminants by the rainfall runoff. The PAHs in water mainly originated from the incomplete combustion of petroleum products and fossil fuels such as coal, as well as natural digenetic process. Compared to other areas in the world, the concentrations of PAH16 were generally at moderately polluted and heavily polluted levels.

  6. 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

  7. [PHAHs levels in soil samples from the E-waste disassembly sites and their sources allocation].

    PubMed

    Zhao, Gao-Feng; Wang, Zi-Jian

    2009-06-15

    Soil samples (each with 3 replicates of - 1 kg, at the top 0-5 cm layer) were collected from each of the e-waste disassembly sites and the control site. Also obtained from each disassembly site were samples (each weighing - 0.2 kg) of cable coating,stuffing powder, and circuit boards chipping. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in soil and in their potential sources, including e-waste residues, were measured using the GC-MS5975B technique. The highest level of PBBs was found in the cable coating among the three e-waste residues, with a concentration of 35.25 ng x g(-1). The contents of low-brominated PBBs (including monobromobiphenyls and dibromobiphenyls) accounted for 38% of the total PBBs concentration observed in cable coating sample. The highest levels of PBDEs and PBDE209 were found in the stuffing powder for electronic component among the collected e-waste residues, with a concentration of 29.71 and 4.19 x 10(3) ng x g(-1). PBDE153 and PBDE183 were the most predominant PBDE congeners, with their concentration accounting for 43% and 24% of the total PBDEs concentration observed in the stuffing powder sample, respectively. Levels of PCBs in cable coating were the highest in these e-waste residues, with a concentration of 680.02 ngx g(-1). The observed values of the three PHAHs in soils from the disassembly site were considerably higher than their corresponding values observed in the control site (p < 0.05), which indicates that these PHAHs from e-waste is the pollution source of local environment. PMID:19662879

  8. [PHAHs levels in soil samples from the E-waste disassembly sites and their sources allocation].

    PubMed

    Zhao, Gao-Feng; Wang, Zi-Jian

    2009-06-15

    Soil samples (each with 3 replicates of - 1 kg, at the top 0-5 cm layer) were collected from each of the e-waste disassembly sites and the control site. Also obtained from each disassembly site were samples (each weighing - 0.2 kg) of cable coating,stuffing powder, and circuit boards chipping. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in soil and in their potential sources, including e-waste residues, were measured using the GC-MS5975B technique. The highest level of PBBs was found in the cable coating among the three e-waste residues, with a concentration of 35.25 ng x g(-1). The contents of low-brominated PBBs (including monobromobiphenyls and dibromobiphenyls) accounted for 38% of the total PBBs concentration observed in cable coating sample. The highest levels of PBDEs and PBDE209 were found in the stuffing powder for electronic component among the collected e-waste residues, with a concentration of 29.71 and 4.19 x 10(3) ng x g(-1). PBDE153 and PBDE183 were the most predominant PBDE congeners, with their concentration accounting for 43% and 24% of the total PBDEs concentration observed in the stuffing powder sample, respectively. Levels of PCBs in cable coating were the highest in these e-waste residues, with a concentration of 680.02 ngx g(-1). The observed values of the three PHAHs in soils from the disassembly site were considerably higher than their corresponding values observed in the control site (p < 0.05), which indicates that these PHAHs from e-waste is the pollution source of local environment.

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

    PubMed

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

    2015-11-01

    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 9mm 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 1-10,000pgμl(-1) and detection limits of <2pgμl(-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 PAH isomers. Using calibration standards, values determined were within 5% of true values over many months. Standard curve r(2) 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±0.84pgμl(-1) with indeno[1,2,3-c,d] pyrene having the lowest LOD at 0.26pgμl(-1) and only two analytes above 2.0pgμl(-1); acenaphthalene (2.33pgμl(-1)) and dibenzo[a,e]pyrene (6.44pgμl(-1)).

  10. 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

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

    PubMed

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

    2015-11-01

    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 9mm 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 1-10,000pgμl(-1) and detection limits of <2pgμl(-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 PAH isomers. Using calibration standards, values determined were within 5% of true values over many months. Standard curve r(2) 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±0.84pgμl(-1) with indeno[1,2,3-c,d] pyrene having the lowest LOD at 0.26pgμl(-1) and only two analytes above 2.0pgμl(-1); acenaphthalene (2.33pgμl(-1)) and dibenzo[a,e]pyrene (6.44pgμl(-1)). PMID:26454790

  12. 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.

  13. 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.

  14. 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.

  15. 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. PMID:15506182

  16. 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.

  17. 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

  18. 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.

  19. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China.

    PubMed

    Liu, Ying; Chen, Ling; Jianfu, Zhao; Qinghui, Huang; Zhiliang, Zhu; Hongwen, Gao

    2008-07-01

    Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust. PMID:18045759

  20. PERSONAL EXPOSURE TO FINE PARTICLE POLYCYCLIC AROMATIC HYDROCARBONS: OUTDOOR SOURCE TRACERS

    EPA Science Inventory


    The most carcinogenic and toxic polycyclic aromatic hydrocarbons (PAH) are the 4-5 ring PAH found preferentially adsorbed to the fine particles (<2.54u in urban ambient air and personal air. Personal exposure to the carcinogenic particle bound PAH is also highly correlated ...

  1. 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...

  2. 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

  3. 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

  4. 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

  5. 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.

  6. Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia.

    PubMed

    Retnam, Ananthy; Zakaria, Mohamad Pauzi; Juahir, Hafizan; Aris, Ahmad Zaharin; Zali, Munirah Abdul; Kasim, Mohd Fadhil

    2013-04-15

    This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841 ng/g with a mean of 363 ng/g dw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores-multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia. PMID:23452623

  7. Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia.

    PubMed

    Retnam, Ananthy; Zakaria, Mohamad Pauzi; Juahir, Hafizan; Aris, Ahmad Zaharin; Zali, Munirah Abdul; Kasim, Mohd Fadhil

    2013-04-15

    This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841 ng/g with a mean of 363 ng/g dw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores-multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia.

  8. Characterization and source identification of hydrocarbons in water samples using multiple analytical techniques.

    PubMed

    Wang, Zhendi; Li, K; Fingas, M; Sigouin, L; Ménard, L

    2002-09-20

    This paper describes a case study in which multiple analytical techniques were used to identify and characterize trace petroleum-related hydrocarbons and other volatile organic compounds in groundwater samples collected in a bedrock aquifer exploited for drinking water purposes. The objective of the study was to confirm the presence of gasoline and other petroleum products or other volatile organic pollutants in those samples in order to assess the respective implication of each of the potentially responsible parties to the contamination of the aquifer. In addition, the degree of contamination at different depths in the aquifer was also of interest. The analytical techniques used for analyses of water samples included gas chromatography-mass spectrometry (GC-MS) and capillary GC with flame-ionization detection, solid-phase microextraction and headspace GC-MS techniques. Chemical characterization results revealed the following: (1) The hydrocarbons in sample A (near-surface groundwater, 0-5 m) were clearly of two types, one being gasoline and the other a heavy petroleum product. The significant distribution of five target petroleum-characteristic alkylkated polycyclic aromatic hydrocarbon homologues and biomarkers confirmed the presence of another heavy petroleum product. The concentrations of the TPHs (total petroleum hydrocarbons) and BTEX (collective name of benzene, toluene, ethylbenzene, and p-, m-, and o-xylenes) were determined to be 1070 and 155 microg/kg of water for sample A, respectively. (2) The deepest groundwater (sample B, collected at a depth ranging between 15 and 60 m) was also contaminated, but to a much lesser degree. The concentrations of the TPH and BTEX were determined to be only 130 and 2.6 microg/kg of water for sample B, respectively. (3) The presence of a variety of volatile chlorinated compounds to the groundwater was also clearly identified. PMID:12350112

  9. Characterization and source identification of hydrocarbons in water samples using multiple analytical techniques.

    PubMed

    Wang, Zhendi; Li, K; Fingas, M; Sigouin, L; Ménard, L

    2002-09-20

    This paper describes a case study in which multiple analytical techniques were used to identify and characterize trace petroleum-related hydrocarbons and other volatile organic compounds in groundwater samples collected in a bedrock aquifer exploited for drinking water purposes. The objective of the study was to confirm the presence of gasoline and other petroleum products or other volatile organic pollutants in those samples in order to assess the respective implication of each of the potentially responsible parties to the contamination of the aquifer. In addition, the degree of contamination at different depths in the aquifer was also of interest. The analytical techniques used for analyses of water samples included gas chromatography-mass spectrometry (GC-MS) and capillary GC with flame-ionization detection, solid-phase microextraction and headspace GC-MS techniques. Chemical characterization results revealed the following: (1) The hydrocarbons in sample A (near-surface groundwater, 0-5 m) were clearly of two types, one being gasoline and the other a heavy petroleum product. The significant distribution of five target petroleum-characteristic alkylkated polycyclic aromatic hydrocarbon homologues and biomarkers confirmed the presence of another heavy petroleum product. The concentrations of the TPHs (total petroleum hydrocarbons) and BTEX (collective name of benzene, toluene, ethylbenzene, and p-, m-, and o-xylenes) were determined to be 1070 and 155 microg/kg of water for sample A, respectively. (2) The deepest groundwater (sample B, collected at a depth ranging between 15 and 60 m) was also contaminated, but to a much lesser degree. The concentrations of the TPH and BTEX were determined to be only 130 and 2.6 microg/kg of water for sample B, respectively. (3) The presence of a variety of volatile chlorinated compounds to the groundwater was also clearly identified.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. An assessment of human influences on sources of polycyclic aromatic hydrocarbons in the estuarine and coastal sediments of China.

    PubMed

    Duan, Xiaoyong; Liu, Jinqing; Zhang, Daolai; Yin, Ping; Li, Yanxia; Li, Xianguo

    2015-08-15

    Sediments collected from the coastal area of China, embracing west coast of Bohai Sea, south coast of Shandong Peninsula, and the Changjiang estuary (listed in order of decreasing north latitude), were analyzed for polycyclic aromatic hydrocarbons (PAHs). ∑PAH (Sixteen US EPA priority PAHs) were 2.7-350.9ng/g. Petroleum residue was the major contributor of PAHs in the coastal sediments of China due to oil leakage from ships and offshore oil fields. The contribution of vehicular emissions in coast of North China was significantly lower than that in the Changjiang Estuary, and the reverse was true for coal combustion. PAH concentrations in the sediment core of the Changjiang estuary steadily increased upward and the variation was primarily due to economic development and severe floods. The impact on PAHs by vehicular emissions (37.2%) and petrogenic sources (45.8%) overwhelmed combustion sources (17.0%).

  15. 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. PMID:27236234

  16. 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.

  17. 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

  18. Method for producing low-cost, high volume hydrogen from hydrocarbon sources

    SciTech Connect

    Bose, Arun C.; Balachandran, Uthamalinga; Kleerfisch, Mark S.; Udovich, Carl A.; Stiegel, Gary J.

    1997-12-01

    A method is described for the conversion of naturally-occurring or biomass-derived lower to higher hydrocarbon (C{sub x}H{sub y},where x may vary from 1--3 and y may vary from 4--8) to low-cost, high-volume hydrogen. In one embodiment, methane, the major component of natural gas, is reacted in a single reaction zone of a mixed-conducting ceramic membrane reactor to form hydrogen via simultaneous partial oxidation and water gas shift reactions at temperatures required for thermal excitations of the mixed-conducting membranes. The hydrogen is produced by catalytically reacting the hydrocarbon with oxygen to form synthesis gas (a mixture of carbon monoxide and hydrogen), followed by a water gas shift (WGS) reaction with steam, wherein both reactions occur in a single reaction zone having a multi-functional catalyst or a combination of catalysts. The hydrogen is separated from other reaction products by membrane-assisted transport or by pressure-swing adsorption technique. Membrane-assisted transport may occur via proton transfer or molecular sieving mechanisms.

  19. 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).

  20. 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.

  1. 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.

  2. Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tokyo Metropolitan area.

    PubMed

    Takada, H; Onda, T; Harada, M; Ogura, N

    1991-09-01

    Molecular distributions of polycyclic aromatic hydrocarbons (PAHs) in street dust samples collected from the Tokyo Metropolitan area were determined by capillary gas chromatography following HPLC fractionation. Three- to six-ring PAHs and sulfur-heterocyclics were detected. PAHs in the dusts were dominated by three and four unsubstituted ring systems with significant amounts of their alkyl homologues. PAHs were widely distributed in the streets, with concentrations (sigma COMB) of a few microgram/g dust. Automobile exhaust, asphalt, gasoline fuel, diesel fuel, tyre particles, automobile crankcase oils, and atmospheric fallout were also analysed. The PAH profile, especially the relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, indicated that PAHs in the street dusts from roads carrying heavy traffic are mainly derived from automobile exhausts; dusts from residential areas have a more significant contribution from atmospheric fallout.

  3. Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tokyo Metropolitan area.

    PubMed

    Takada, H; Onda, T; Harada, M; Ogura, N

    1991-09-01

    Molecular distributions of polycyclic aromatic hydrocarbons (PAHs) in street dust samples collected from the Tokyo Metropolitan area were determined by capillary gas chromatography following HPLC fractionation. Three- to six-ring PAHs and sulfur-heterocyclics were detected. PAHs in the dusts were dominated by three and four unsubstituted ring systems with significant amounts of their alkyl homologues. PAHs were widely distributed in the streets, with concentrations (sigma COMB) of a few microgram/g dust. Automobile exhaust, asphalt, gasoline fuel, diesel fuel, tyre particles, automobile crankcase oils, and atmospheric fallout were also analysed. The PAH profile, especially the relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, indicated that PAHs in the street dusts from roads carrying heavy traffic are mainly derived from automobile exhausts; dusts from residential areas have a more significant contribution from atmospheric fallout. PMID:1785054

  4. 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

  5. Acute childhood leukaemia and environmental exposure to potential sources of benzene and other hydrocarbons; a case-control study

    PubMed Central

    Steffen, C; Auclerc, M; Auvrignon, A; Baruchel, A; Kebaili, K; Lambilliotte, A; Leverger, G; Sommelet, D; Vilmer, E; Hemon, D; Clavel, J

    2004-01-01

    Aim: To analyse the association between potential environmental exposure to hydrocarbons and the risk of acute childhood leukaemia. Methods: A hospital based multicentre case control study, stratified on centre, age, and sex, with 280 leukaemia cases and 285 controls was carried out. Data were collected by a standardised interview of the mothers. Results: No clear association was seen between maternal occupational exposure to hydrocarbons during pregnancy and leukaemia, or between residential traffic density and leukaemia. There was an association between dwellings neighbouring a petrol station or a repair garage during childhood and the risk of childhood leukaemia (OR 4.0, 95% CI 1.5 to 10.3), with a duration trend. The association, which appeared particularly strong for acute non-lymphocytic leukaemia (OR 7.7, 95% CI 1.7 to 34.3), was not altered by adjustment for potential confounding factors. Conclusions: Results showed an association between acute childhood leukaemia and dwellings neighbouring auto repair garages and petrol stations, which are benzene emitting sources. These findings could be due to chance, although the strength of the association and the duration trend are arguments for a causal association. PMID:15317919

  6. Resource Allocation.

    ERIC Educational Resources Information Center

    Stennett, R. G.

    A research allocation formula employed in London, Ontario elementary schools, as well as supporting data on the method, are provided in this report. Attempts to improve on the traditional methods of resource allocation in London's schools were based on two principles: (1) that need for a particular service could and should be determined…

  7. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.

  8. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks. PMID:26771587

  9. 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. PMID:24022101

  10. [Study on degradation of polycyclic aromatic hydrocarbons (PAHs) with different additional carbon sources in aged contaminated soil].

    PubMed

    Yin, Chun-Qin; Jiang, Xin; Wang, Fang; Wang, Cong-Ying

    2012-02-01

    This study was conducted with different additional carbon sources (such as: glucose, DL-malic acid, citrate, urea and ammonium acetate) to elucidate the degradation of polycyclic aromatic hydrocarbons (PAHs) in aged contaminated soil under an indoor simulation experiment. The results showed that the quantity of CO2 emission in different additional carbon sources treatments was obviously much more than that of check treatment in the first week, and the quantity of CO2 emission in DL-malic acid treatment was the largest. The average CO2 production decreased in an order urea > glucose approximately citrate approximately DL-malic acid approximately ammonium acetate > check. Meanwhile, the amount of volatized PAHs in applied carbon sources treatments was significantly less than that in check treatment. The amount of three volatized PAHs decreased in an order phenanthrene > fluoranthene > benzo(b)fluoranthene. Compared with the check treatment, the average degradation rates of the three PAHs were significantly augmented in the supplied carbon sources treatments, in which rates of the three PAHs were much higher in DL-malic acid and urea treatments than those in other treatments. The largest proportion of residual was benzo(b)fluoranthene (from 72% to 81%) among three PAHs compounds, followed by fluoranthene (from 53% to 70% ) and phenanthrene (from 27% to 44%).

  11. Use of diagnostic ratios for studying source apportionment and reactivity of ambient polycyclic aromatic hydrocarbons over Central Europe

    NASA Astrophysics Data System (ADS)

    Dvorská, Alice; Lammel, Gerhard; Klánová, Jana

    2011-01-01

    Ratios of levels of 9 polycyclic aromatic hydrocarbons (PAHs) in air at central European sites during 1996-2008 were used to assess the suitability of 5 commonly used diagnostic ratios (DRs) for PAH source apportionment. DRs derived from a detailed literature study on emission factors were reflected in ambient air samples only at sites located near major sources. A significant seasonality was observed in a long-term time series of ambient DRs at a background site indicating possible capability of this method to reflect changes in source characteristics. The results of a mass balance study suggest that current knowledge of PAH reactivities is insufficient for a source apportionment based on DRs at receptor sites, even when limited to major types of PAH sources. However, DRs could be used to narrow down ozone and hydroxyl radical reaction rate coefficients' uncertainties: k O 3(2) of pyrene and benzo(ghi)perylene in the particulate phase seem to be ≤ 10% of the highest rate coefficient measured using model aerosols in the laboratory and k O 3(2) of indeno(1,2,3-cd)pyrene in the gas phase could be higher than previously estimated by three orders of magnitude. The suitability of DRs for source apportionment at (especially background) receptor sites cannot be expected in the general case. However, measurements carried out close to sources are in accordance with literature data suggesting that the ratios of benzo(a)anthracene/(benzo(a)anthracene + chrysene) and indeno(123cd)pyrene/(indeno(123cd)pyrene + benzo(ghi)perylene) are capable of distinguishing between traffic and residential heating, while the ratio of anthracene/(anthracene + phenanthrene) was the least useful DR due to its low variability.

  12. Source apportionment of polycyclic aromatic hydrocarbons in PM2.5 using positive matrix factorization modeling in Shanghai, China.

    PubMed

    Wang, Fengwen; Lin, Tian; Feng, Jialiang; Fu, Huaiyu; Guo, Zhigang

    2015-01-01

    Providing quantitative information on the sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in urban regions is vital to establish effective abatement strategies for air pollution in a megacity. In this study, based on a year data set from October 2011 to August 2012, the sources of PM2.5-bound 16 USEPA priority PAHs (16 PAHs) in Shanghai, a megacity in China, were apportioned by positive matrix factorization (PMF) modeling. The average concentrations (in ng m(-3)) of 16 PAHs in PM2.5 in the fall, winter, spring and summer were 20.5 ± 18.2, 27.2 ± 24.0, 13.7 ± 7.7 and 6.4 ± 8.1, respectively, with an annual average of 16.9 ± 9.0. The source apportionment by PMF indicated that coal burning (30.5%) and gasoline engine emission (29.0%) were the two major sources of PAHs in the PM2.5 in Shanghai, followed by diesel engine emission (17.5%), air-surface exchange (11.9%) and biomass burning (11.1%). The highest source contributor for PAHs in the fall and winter was gasoline engine emission (36.7%) and coal burning (41.9%), respectively; while in the spring and summer, it was diesel engine emission that contributed the most (52.1% and 43.5%, respectively). It was suggested that there was a higher contribution of PAHs from engine emissions in 2011-2012 compared with those in 2002-2003. The major sources apportioned by PMF complemented well with this of using diagnostic ratios, suggesting a convincing identification of sources for the PM2.5-bound 16 PAHs in a megacity. PMID:25493422

  13. 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. PMID:24530732

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:26806662

  20. 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.

  1. Characteristics and sources of non-methane hydrocarbons and halocarbons in wintertime urban atmosphere of Shanghai, China.

    PubMed

    Song, Ping; Geng, Fu-Hai; Sang, Xue-Fang; Chan, Chuen-Yu; Chan, Lo-Yin; Yu, Qiong

    2012-10-01

    The characteristics and sources of major hydrocarbons and halocarbons in the wintertime ambient air of urban center of Shanghai, a mega city of China, were investigated. Propane, toluene, ethyl acetate, and benzene were the most abundant hydrocarbons. The majority of species showed significant variability in mixing ratios with occasional episodic increases. The more common use of liquefied petroleum gas fuel for taxis and light motorcycles was believed to lead to high levels of ambient propane over the urban center of Shanghai. Correlating with toluene, dichloromethane, and 1,2-dichloroethane (1,2-DCE), abundant chloromethane (up to a daily mean of 1.61 ± 0.99 ppbv and a maximum of 5.34 ppbv) was mainly associated with industrial emissions, although biomass burnings exist widely in east China. The Chinese New Year (CNY) holiday period with no industrial activity over China provides a platform for the study of industrial emissions over the urban atmosphere of Shanghai. The normal weekly cycles were characterized by higher and more variable mixing ratios during weekdays which dropped during weekends. Enhanced mixing ratios were observed in the fortnight before the CNY holidays due to increased industrial emissions as a result of overtime production to make up for the holiday losses. During the CNY holidays, lower level and less variable mixing ratios were observed. A benzene/toluene (B/T) ratio of 0.6 ± 0.4 (mean ± std.) for the morning rush hour samples was identified to be the characteristic ratio of vehicular emissions. However, a B/T ratio of 0.4 ± 0.2 from vehicles and other sources was derived for the ambient air.

  2. 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. PMID:15543735

  3. 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.

  4. Source seasonality of polycyclic aromatic hydrocarbons (PAHs) in a subtropical city, Guangzhou, South China.

    PubMed

    Li, J; Zhang, G; Li, X D; Qi, S H; Liu, G Q; Peng, X Z

    2006-02-15

    Mega-cities are large sources of air pollution on a regional base. Differences in energy structures, geographical settings and regional climate features lead to a large variety of air pollution sources from place to place. To understand the seasonality of air pollution sources is critical to precise emission inventories and a sound protection of human health. Based on a year-round dataset, the sources of PAHs in the air of Guangzhou were drawn by principal factor analysis (PCA) in combination with diagnostic ratios, and the seasonality of these sources were analyzed by PCA/MLR (multiple linear regressions) and discussed. The average total gaseous and particulate PAHs concentrations were 313 and 23.7 ng m(-3), respectively, with a higher concentration of vapor PAHs in summer and particulate PAHs in winter. In addition to vehicle exhaust, which contributed 69% of the particulate PAHs, coal combustion was still an important source and contributed 31% of the particulate PAHs. Relatively constant contribution from coal combustion was found through the year, implying that coal combustion in power plants was not a seasonally dependent source. Evaporation from contaminated ground may be an important source of light PAHs in summer, providing an average contribution of 68% to the total PAHs in this study. By comparing the PAH concentrations and meteorological parameters, we found that higher concentrations of particulate PAHs in winter resulted from enhanced vehicle exhaust under low temperature and accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. It is suggested that the typical subtropical monsoon climate in South China, cool and dry in winter, hot and humid in summer, may play a key role in controlling the source seasonality (by enhancing vehicle exhaust in winter, ground evaporation in summer), and hence the ambient concentrations of PAHs in the air.

  5. 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.

  6. 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.

  7. 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. PMID:25139034

  8. Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution

    PubMed Central

    ZHU, XIANLEI; FAN, ZHIHUA (TINA); WU, XIANGMEI; JUNG, KYUNG HWA; OHMAN-STRICKLAND, PAMELA; BONANNO, LINDA J.; LIOY, PAUL J.

    2014-01-01

    Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ~1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44–96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution. PMID:21364704

  9. Sources of polycyclic aromatic hydrocarbons (PAHs) in street dust in a tropical Asian mega-city, Bangkok, Thailand.

    PubMed

    Boonyatumanond, Ruchaya; Murakami, Michio; Wattayakorn, Gullaya; Togo, Ayako; Takada, Hideshige

    2007-10-01

    We collected samples of roadside air, automobile exhaust soot, tires, asphalt, and used engine oil in a tropical Asian mega-city, Bangkok, Thailand, and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. The concentrations and compositions of PAHs and hopanes were utilized to identify the sources of PAHs in street dust, in which high concentrations of PAHs were reported in our previous study. Weight-based concentrations of total PAHs had the following order: gasoline-powered vehicle soot (2600+/-2900 microg/g; n=4)>diesel-powered vehicle soot (115+/-245 microg/g; n=7) approximately roadside aerosols (101+/-35 microg/g; n=5) approximately used engine oil (97+/-65 microg/g; n=4) approximately tire wear particles (82+/-41 microg/g; n=5)>asphalt (2.3+/-1.6 microg/g; n=3)>street dust (1.1+/-0.8 microg/g; n=10). In cluster analysis, all the source materials fell into different clusters from that in which street dust fell, indicating that multiple source materials contribute to PAHs in the street dust. Multiple regression analysis of PAH profiles and diagnostics of hopane compositions identified tire debris as the major contributor of PAHs to street dust, followed by diesel vehicle exhaust.

  10. 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.

  11. 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. PMID:23623160

  12. Sources and distribution of polycyclic aromatic hydrocarbons in the sediments of Kaoping River and submarine canyon system, Taiwan.

    PubMed

    Fang, Meng-Der; Hsieh, Ping-Chieh; Ko, Fung-Chi; Baker, Joel E; Lee, Chon-Lin

    2007-08-01

    In this study, we measured and analyzed polycyclic aromatic hydrocarbons (PAHs) in surface sediment samples collected from the Kaoping river and submarine canyon (KPSC) system to determine the compositional patterns and characteristic distributions of PAH and to elucidate the transport and fate of these land-derived particles. Concentrations of total PAH (sum of 28 PAH compounds) ranged from 22.6 to 45,100 ngg(-1) dry weight (dw) and the highest concentrations were found in the sediments of Donggang Harbor. The ratio of perylene to sum of penta-aromatic PAH isomers (47-55%) was higher in off-shore stations, suggesting a diagenetic PAH source. Various isomeric ratios also indicated that combustion was a significant source of PAH to the sediment at stations located along the Kaoping river and the north-western shelf of the Kaoping estuary. However, in the south-eastern shelf and some canyon sites, petroleum-derived PAHs were a more significant source of these compounds. Principal component analysis and hierarchical cluster analysis suggest PAHs in the sediments from the north-western shelf, and river and canyon sediments might be a pyrogenic product of coal and diesel-burning vehicles, while those of the south-eastern shelf may be petrogenic. PAH concentrations and compositional patterns are effective tracers of particulate transport in KPSC system. The seaward transport of riverine particulates was found to be mostly directed to NW-shelf and/or canyon. PMID:17574277

  13. Application of radiocarbon analysis and receptor modeling to the source apportionment of PAHs (polycyclic aromatic hydrocarbons) in the atmosphere

    SciTech Connect

    Sheffield, A.E.

    1988-01-01

    The radiocarbon tracer technique was used to demonstrate that polycyclic aromatic hydrocarbons (PAHs) can be used for quantitative receptor modeling of air pollution. Fine-particle samples were collected during December, 1985, in Albuquerque, NM. Motor vehicles (fossil) and residential wood combustion (RWC, modern) were the major PAH-sources. For each sample, the PAH-fraction was solvent-extracted, isolated by liquid chromatography, and analyzed by GC-FID and GC-MS. The PAH-fractions from sixteen samples were analyzed for {sup 14}C by Accelerator Mass Spectrometry. Radiocarbon data were used to calculate the relative RWC contribution (f{sub RWC}) for samples analyzed for {sup 14}C. Normalized concentrations of a prospective motor vehicle tracer, benzo(ghi)perylene (BGP) had a strong, negative correlation with f{sub RWC}. Normalized BGP concentrations were used to apportion sources for samples not analyzed for {sup 14}C. Multiple Linear Regression (MLR) vs. ADCS and BGP was used to estimate source profiles for use in Target Factor Analysis (TFA). Profiles predicted by TFA were used in Chemical Mass Balances (CMBs). For non-volatile, stable PAHs, agreement between observed and predicted concentrations was excellent. The worst fits were observed for the most volatile PAHs and for coronene. The total RWC contributions predicted by CMBs correlated well with the radiocarbon data.

  14. 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.

  15. 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. PMID:27265739

  16. Distribution and sources of the polycyclic aromatic hydrocarbons in the sediments of the Pearl River estuary, China.

    PubMed

    Zhang, Jian-Dong; Wang, You-Shao; Cheng, Hao; Jiang, Zhao-Yu; Sun, Cui-Ci; Wu, Mei-Lin

    2015-10-01

    The Pearl River delta, one of the most prosperous economically region in China, has experienced significant contaminant inputs. However, the dynamics of pollutants in the Pearl River estuary and the adjacent coastal areas are still unclear at present. In the paper, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments of the Pearl River estuary. The total PAHs concentrations ranged from 126.08 to 3828.58 ng/g with a mean value of 563.52 ng/g, whereas the highest PAHs were observed in Guangzhou channel. Among the U.S. Environmental Protection Agency's 16 priority PAHs, PAHs with 3-4 rings exhibited relative higher levels. A positive relationship was found between PAHs and total organic carbon. The source analysis further showed that the major sources of PAHs in the Pearl River estuary were originated from the pyrolytic inputs, reflecting a mixed energy structure such as wood, coal and petroleum combustion. In summary, although PAHs in Lingding Bay and the adjacent coastal areas of the Pearl River estuary exhibited a relatively low pollution level, the relatively high pollution level of PAHs in Guangzhou channel will be attended.

  17. 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.

  18. 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

  19. Source apportionment of polycyclic aromatic hydrocarbon wet and dry deposition at Massachusetts Bay

    NASA Astrophysics Data System (ADS)

    Fisher, George F.

    2001-07-01

    Polycyclic aromatic hydrocarbons (PAHs) result from incomplete combustion of fossil fuels and biomass. They are toxic, mutagenic and carcinogenic. PAHs are transported by winds until they are deposited on land or water or are chemically degraded. Wet deposition occurs when PAHs deposit during precipitation. Dry deposition occurs through direct impingment with the surface or through gas-exchange. An improved, computer controlled deposition collector was designed and developed to specifically collect PAH deposition. Wet deposition falls directly into a funnel while dry deposition is collected on a water surface, simulating deposition onto the ocean. Both samples drain quickly into a sample bottle which prevents sample volatilization and loss. Collected samples were analyzed with a gas chromatograph mass spectrometer (GC/MS). Analysis of backward air parcel trajectories showed the highest wet deposition was associated with trajectories through the northeast urban industrial corridor between Washington, DC and Boston, MA. The degree of industrialization and population along the trajectory route and exposure time affected wet deposition amounts. Dry deposition samples were analyzed using wind roses and local area trajectories. Deposition rates were related to the wind climatology with highest deposition associated with winds from the concentrated commercial and population areas west of the collection site. Increased deposition associated with easterly sectors indicate aircraft operations in those directions may contribute significantly to dry deposition. Deposition roses apportion 26% southeast, 22.9% west, 20.5% northwest, 17.9% north, 8.5% southwest and 4.2% northeast. Trajectory analysis showed that longer exposure times produced higher deposition rates. Both wet and dry deposition showed seasonal trends. Winter recorded the highest deposition due to increased fuel combustion for heating and lower mixing depths. The ability to collect dry deposition only when the

  20. Characteristics and sources of polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu Valley, Nepal.

    PubMed

    Chen, Pengfei; Kang, Shichang; Li, Chaoliu; Rupakheti, Maheswar; Yan, Fangping; Li, Quanlian; Ji, Zhenming; Zhang, Qianggong; Luo, Wei; Sillanpää, Mika

    2015-12-15

    The Kathmandu Valley in the foothills of the Himalayas, where the capital city of Nepal is located, has one of the most serious air pollution problems in the world. In this study, total suspended particle (TSP) samples collected over a year (April 2013-March 2014) in the Kathmandu Valley were analyzed for determining the concentrations of 15 priority particle-bound polycyclic aromatic hydrocarbons (PAHs). The TSP and PAH concentrations were extremely high, with annual average concentration being 199±124μg/m(3) and 155±130ng/m(3), respectively, which are comparable to those observed in Asian cities such as Beijing and Delhi. The TSP and PAH concentrations varied considerably, with the seasonal average concentration being maximal during the post-monsoon season followed by, in descending order, the winter, pre-monsoon, and monsoon seasons. In the winter and pre-monsoon seasons, ambient TSP and PAH concentrations increased because of emissions from brick kilns and the use of numerous small generators. Moreover, in the pre-monsoon season, forest fires in the surrounding regions influenced the TSP and PAH concentrations in the valley. PAHs with 4 to 6 rings constituted a predominant proportion (92.3-93.3%) of the total PAHs throughout the year. Evaluation of diagnostic molecular ratios indicated that the atmospheric PAHs in the Kathmandu Valley originated mainly from diesel and biomass combustion. The toxic equivalent quantity (TEQ) of particle phase PAHs ranged between 2.74 and 81.5ngTEQ/m(3), which is considerably higher than those reported in other South Asian cities, and 2-80 times higher than the World Health Organization guideline (1ngTEQ/m(3)). This suggests that ambient PAH levels in the Kathmandu Valley pose a serious health risk to its approximately 3.5 million residents. PMID:26298251

  1. Sources, fate, and toxic hazards of oxygenated polycyclic aromatic hydrocarbons (PAHs) at PAH-contaminated sites.

    PubMed

    Lundstedt, Staffan; White, Paul A; Lemieux, Christine L; Lynes, Krista D; Lambert, Iain B; Oberg, Lars; Haglund, Peter; Tysklind, Mats

    2007-09-01

    In this paper we show that oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are important cocontaminants that should be taken into account during risk assessment and remediation of sites with high levels of PAHs. The presented data, which have been collected both from our own research and the published literature, demonstrate that oxy-PAHs are abundant but neglected contaminants at these sites. The oxy-PAHs show relatively high persistency and because they are formed through transformation of PAHs, their concentrations in the environment may even increase as the sites are remediated by methods that promote PAH degradation. Furthermore, we show that oxy-PAHs are toxic to both humans and the environment, although the toxicity seems to be manifested through other effects than those known to be important for polycyclic aromatic compounds in general, that is, mutagenicity and carcinogenicity. Finally, we present data that support the hypothesis that oxy-PAHs are more mobile in the environment than PAHs, due to their polarity, and thus have a higher tendency to spread from contaminated sites via surface water and groundwater. We believe that oxy-PAHs should be included in monitoring programs at PAH-contaminated sites, even if a number of other toxicologically relevant compounds that may also be present, such as nitro-PAHs and azaarenes, are not monitored. This is because oxy-PAH levels are difficult to predict from the PAH levels, because their environmental behavior differs substantially from that of PAHs, and oxy-PAHs may be formed as PAHs are degraded.

  2. Distribution and potential sources of polycyclic aromatic hydrocarbons in soils around coal-fired power plants in South Africa.

    PubMed

    Okedeyi, Olumuyiwa O; Nindi, Mathew M; Dube, Simiso; Awofolu, O R

    2013-03-01

    The distribution and potential sources of 15 polycyclic aromatic hydrocarbons (PAHs) in soils in the vicinity of three South African coal-fired power plants were determined by gas chromatography-mass spectrometry. PAH compound ratios such as phenanthrene/phenanthrene + anthracene (Phen/Phen + Anth) were used to provide reliable estimation of emission sources. The total PAH concentration in the soils around three power plants ranged from 9.73 to 61.24 μg g(-1), a range above the Agency for Toxic Substances and Disease Registry levels of 1.0 μg g(-1) for significantly contaminated site. Calculated values of Phen/Phen + Anth ratio were 0.48 ± 0.08, 0.44 ± 0.05, and 0.38 + 0.04 for Matla, Lethabo, and Rooiwal, respectively. Flouranthene/fluoranthene + pyrene (Flan/Flan + Pyr) were found to be 0.49 ± 0.03 for Matla, 0.44 ± 0.05 for Lethabo, and 0.53 ± 0.08 for Rooiwal. Such values indicate a pyrolytic source of PAHs. Higher molecular weight PAHs (five to six rings) were predominant, suggesting coal combustion sources. A good correlation existed between most of the PAHs implying that these compounds were emitted from similar sources. The carcinogenic potency B[a]P equivalent concentration (B[a] Peq) at the three power plants ranged from 3.61 to 25.25 indicating a high carcinogenic burden. The highest (B[a] Peq) was found in samples collected around Matla power station. It can therefore be concluded that the soils were contaminated with PAHs originating from coal-fired power stations. PMID:22661359

  3. Source Attribution of Personal Exposure to Airborne Polycyclic Aromatic Hydrocarbon Mixture Using Concurrent Personal, Indoor, and Outdoor Measurements

    PubMed Central

    Choi, Hyunok; Spengler, John

    2014-01-01

    Objectives Relative importance of multiple indoor and outdoor venues on personal exposure concentrations to pro-carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) remains poorly understood. This is particularly challenging because many c-PAHs share sources and occur as a complex mixture. Accurate and precise apportionment of personal exposure according to exposure venues could aid in understanding of human health effects due to given source. Here, we partitioned indoor and personal exposure concentrations to seven c-PAHs and pyrene according to the indoor- and outdoor- origins. Methods A simultaneous, integrated monitoring of personal, indoor and outdoor concentrations of nine PAHs was conducted in 75 homes for a consecutive 48-hour period across a two-year period in Kraków, Poland. Due to few known indoor sources for chrysene, we used this PAH species as a tracer for infiltration of outdoor PAHs. Personal and indoor concentrations of seven c-PAHs and pyrene were apportioned to home indoor, non-home indoor and outdoor origin. Results Using Chrysenein / Chryseneout as proxy for an infiltration factor, Finf, infiltrated PAHs of outdoor origin are overall higher in concentration than those emitted from the indoor origin. Average contribution by the outdoor sources on B[a]A, B[b]F, and B[k]F were 92%, 79%, and 78% across all seasons. In contrast, in homes where a household members smoked, average contribution by the outdoor sources on B[ghi]P, B[a]P, D[ah]A, and IP were lower (i.e., 67%, 65%, 67%, and 66%, respectively). Season-averaged contribution by the outdoor sources on personal exposure to B[a]A, B[b]F, and B[k]F were 92%, 74%, and 77%, respectively. On the other hand, season-averaged home indoor source contribution on personal exposure to B[a]A, B[b]F, and B[k]F were estimated at 6%, 15%, and 19%, respectively. Similar contributions by season-averaged home indoor sources on personal exposure were estimated at 28% for B[ghi]P, 31% for B[a]P, 25% for D

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

    PubMed

    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.

  5. 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

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

    PubMed

    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

  7. 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.

  8. 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.

  9. 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. PMID:25240101

  10. 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.

  11. 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.

  12. 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. PMID:26636429

  13. 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. PMID:25712884

  14. 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. PMID:25893756

  15. Historical records of polycyclic aromatic hydrocarbon deposition in a shallow eutrophic lake: Impacts of sources and sedimentological conditions.

    PubMed

    Li, Chaocan; Huo, Shouliang; Yu, Zhiqiang; Guo, Wei; Xi, Beidou; He, Zhuoshi; Zeng, Xiangying; Wu, Fengchang

    2016-03-01

    Sediment core samples collected from Lake Chaohu were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) to assess the spatial and temporal distributions of the PAHs during lacustrine sedimentary processes and regional economic development. Assessing the PAH sedimentary records over an approximately 100-year time span, we identified two stages in the PAH inputs and sources (before the 1970s and after the 1970s) in the eastern lake region near a village, whereas three stages (before the 1950s, 1950s-1990s and after the 1990s) were identified in the western lake region near urban and industrial areas. Rapid increases in the PAH depositional fluxes occurred during the second stage due to increased human activities in the Lake Chaohu basin. The composition and isomeric ratios of the PAHs revealed that pyrolysis is the main source of PAHs in this lake. Strong positive relationships between PAH concentration and the total organic carbon concentration, sediment grain size (<4μm), as well as the local population and Gross Domestic Product indicated that the sedimentary conditions impact the depositional characteristics of the PAHs; simultaneously, socioeconomic activities, such as energy consumption and the levels of urban industrialization and civilization, affect both the composition and abundance of the PAHs. PMID:26969073

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. [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.

  2. The Unobtrusive Memory Allocator

    2003-03-31

    This library implements a memory allocator/manager which ask its host program or library for memory refions to manage rather than requesting them from the operating system. This allocator supports multiple distinct heaps within a single executable, each of which may grow either upward or downward in memory. The GNU mmalloc library has been modified in such a way that its allocation algorithms have been preserved, but the manner in which it obtains regions to managemore » has been changed to request memory from the host program or library. Additional modifications allow the allocator to manage each heap as either upward or downward-growing. By allowing the hosting program or library to determine what memory is managed, this package allows a greater degree of control than other memory allocation/management libraries. Additional distinguishing features include the ability to manage multiple distinct heaps with in a single executable, each of which may grow either upward or downward in memory. The most common use of this library is in conjunction with the Berkeley Unified Parallel C (UPC) Runtime Library. This package is a modified version of the LGPL-licensed "mmalloc" allocator from release 5.2 of the "gdb" debugger's source code.« less

  3. 40 CFR 74.26 - Allocation formula.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.26 Allocation formula. (a) The Administrator will calculate the annual allowance allocation for a combustion source based on the data... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Allocation formula. 74.26 Section...

  4. A pulsed photoacoustic system for the spectroscopy and monitoring of hydrocarbon liquids using stimulated Raman scattering in a silica fibre as a near-infrared source

    NASA Astrophysics Data System (ADS)

    Hannigan, J.; Greig, F.; Freeborn, S. S.; MacKenzie, H. A.

    1999-02-01

    Raman scattering in an optical fibre has been utilized as the near-infrared source for a pulsed photoacoustic spectroscopic study of liquid hydrocarbons. An open-cell system is described and the performance criteria for practical photoacoustic instrumentation are discussed. Results show that a typical signal-to-noise ratio of 50 may be achieved, which makes this system suitable for the detection of small concentrations of hydrocarbons in liquids. The photoacoustic system has been used to measure concentrations both of dissolved and of dispersed hydrocarbons and the results of this study indicate the practical potential for novel open-cell photoacoustic instrumentation for the detection of crude oil in water using near-infrared wavelengths in a spectral region for which suitable diode lasers are available.

  5. 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.

  6. 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.

  7. Source, distribution, and health risk assessment of polycyclic aromatic hydrocarbons in urban street dust from Tianjin, China.

    PubMed

    Yu, Binbin; Xie, Xiujie; Ma, Lena Q; Kan, Haidong; Zhou, Qixing

    2014-02-01

    To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents' exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg(-1) to 34.3 mg kg(-1), averaging 7.99 mg kg(-1). According to PCA, the two to three- and four to six-ring PAHs contributed 10.3 and 89.7 % of ∑PAHs, respectively. The ratio of the sum of major combustion specific compounds (ΣCOMB) / ∑PAHs varied from 0.57 to 0.79, averaging 0.64. The ratio of Ant/(Ant + Phe) varied from 0.05 to 0.41, averaging 0.10; Fla/(Fla + Pyr) from 0.40 to 0.68, averaging 0.60; BaA/(BaA + Chry) from 0.29 to 0.51, averaging 0.38; and IcdP/(IcdP + BghiP) from 0.07 to 0.37, averaging 0.22. The biomass combustion, coal combustion, and traffic emission were the main sources of PAHs in urban street dust with the similar proportion. According to the ILCR model, the total cancer risk for children and adults was up to 2.55 × 10(-5) and 9.33 × 10(-5), respectively.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Composition, sources, and potential toxicology of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils in Liaoning, People's Republic of China.

    PubMed

    Cao, Xiu Feng; Liu, Miao; Song, Yu Fang; Ackland, M Leigh

    2013-03-01

    Surface soil (0-20 cm) samples (n = 143) were collected from vegetable, maize, and paddy farmland used for commercial crops in Liaoning, China. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) listed in US Environmental Protection Agency were analyzed by high-performance liquid chromatography using a fluorescence detector. The soil concentrations of the 16 PAH ranged from 50 to 3,309 ng/g with a mean of 388 ng/g. The highest concentration of total PAHs found in soil of the vegetable farmland was 448 ng/g in average, followed by maize and paddy with total PAHs of 391 and 331 ng/g, respectively. Generally, the low molecular weight PAHs were more predominant than the high molecular weight PAHs in most of the soils. The evaluation of soil PAH contamination based on the Canadian criterion indicated that only naphthalene, phenanthrene, and pyrene were over the target values in several sampling sites. Isomer pair ratios and principal component analysis indicated that biomass and coal combustion were the main sources of PAHs in this area. And the average value of total B[a]Peq concentration in vegetable soils was higher than paddy and maize soils. We suggest that biomass burning should be abolished and commercial farming should be carried out far from the highways to ensure the safety of food products derived from commercial farming.

  13. Vehicle Traffic as a Source of Particulate Polycyclic Aromatic Hydrocarbon Exposure in the Mexico City Metropolitan Area

    PubMed Central

    MARR, LINSEY C.; GROGAN, LISA A.; WÖHRNSCHIMMEL, HENRY; MOLINA, LUISAT.; MOLINA, MARIO J.; SMITH, THOMAS J.; GARSHICK, ERIC

    2005-01-01

    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. PMID:15180054

  14. Diurnal variation, vertical distribution and source apportionment of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Chiang-Mai, Thailand.

    PubMed

    Pongpiachan, Siwatt

    2013-01-01

    Diurnal variation of particulate polycyclic aromatic hydrocarbons (PAHs) was investigated by collecting PM10 at three different sampling altitudes using high buildings in the city center of Chiang-Mai, Thailand, during the relatively cold period in late February 2008. At site-1 (12 m above ground level), B[a]P concentrations ranged from 30.3 -1,673 pg m-3 with an average of 506±477 pg m-3, contributing on average, 8.09±8.69% to ?PAHs. Ind and B[b]F concentrations varied from 54.6 to 4,579 pg m-3 and from 80.7 to 2,292 pg m-3 with the highest average of 1,187±1,058 pg m-3 and 963±656 pg m-3, contributing on average, 19.0±19.3% and 15.4±12.0% to ?PAHs, respectively. Morning maxima were predominantly detected in all observatory sites, which can be described by typical diurnal variations of traffic flow in Chiang-Mai City, showing a morning peak between 6 AM. and 9 AM. Despite the fact that most monitoring sites might be subjected to specific-site impacts, it could be seen that PAH profiles in Site-1 and Site-2 were astonishingly homogeneous. The lack of differences suggests that the source signatures of several PAHs become less distinct possibly due to the impacts of traffic and cooking emissions from ground level. PMID:23679286

  15. 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

  16. Polycyclic aromatic hydrocarbons in upstream riverine runoff of the Pearl River Delta, China: an assessment of regional input sources.

    PubMed

    Zhang, Kai; Liang, Bo; Wang, Ji-Zhong; Guan, Yu-Feng; Zeng, Eddy Y

    2012-08-01

    Water samples collected from upstream tributaries of the Pearl River Delta (PRD) and from locations within the PRD (South China) were analyzed for 27 polycyclic aromatic hydrocarbons (PAHs). Average concentrations (aqueous plus particulate) of total 27 PAHs (Σ(27)PAH), 16 priority PAHs designated by the United States Environmental Protection Agency (USEPA) except naphthalene (Σ(15)PAH), and the seven carcinogenic PAHs (Σ(7)PAH) classified by the USEPA were 260 ± 410, 130 ± 310, and 15 ± 12 ng/L, respectively. Riverine PAHs were predominantly generated from coal and vegetation combustion, coke production, vehicle exhausts, and petroleum residues, accounting for 28%, 25%, 22% and 21%, respectively, on average. Upstream riverine fluxes of Σ(27)PAH and Σ(15)PAH amounted to 38.9 and 12.9 tons/year, respectively. The net contributions of Σ(27)PAH and Σ(15)PAH from sources within the PRD were estimated at 21.4 and 21.0 tons/year, respectively.

  17. 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

  18. Polycyclic aromatic hydrocarbons in Haliotis tuberculata (Linnaeus, 1758) (Mollusca, Gastropoda): Considerations on food safety and source investigation.

    PubMed

    Conte, Francesca; Copat, Chiara; Longo, Sabrina; Conti, Gea Oliveri; Grasso, Alfina; Arena, Giovanni; Dimartino, Angela; Brundo, Maria Violetta; Ferrante, Margherita

    2016-08-01

    Polycyclic aromatic hydrocarbons were analyzed in wild specimens of Haliotis tuberculata from three sites of the Sothern Ionian Sea. The species Ht is commonly found at these sites and has significant commercial value. Main results revealed mean values of benzo(a)pyrene higher than the threshold set by Regulation No. 835/2011/EU in all sampling sites and the sum of selected PAHs, expressed as ΣPAH4 by EC Regulation, were below the limit set by the same Regulation in ME and VSG. We found generally higher concentrations than literature finding, especially for low molecular weight PAHs, and results of diagnostic ratios highlighted both pyrolytic and petrogenic sources. The potential human health risks due consumption of Ht by local inhabitants have been assessed by exposure daily intake (EDI), target hazard quotient (THQ) and lifetime cancer risk (CR). EDI values were below the intake range reviewed by EFSA for each class of contaminant. BaP daily intake was below the value of 10 ng/Kg/day, suggested by JFCFA, and CRBaP was slightly higher than the acceptable risk level (ARL) of 1×10(-5). Conversely, target hazard quotient (THQ) resulted always below 1, thus the risk to develop chronic systemic effects due naphthalene, acenaphthene, fluorene, anthracene, fluoranthene and pyrene was low. PMID:27235950

  19. Polycyclic Aromatic Hydrocarbons Bound to PM 2.5 in Urban Coimbatore, India with Emphasis on Source Apportionment

    PubMed Central

    Mohanraj, R.; Dhanakumar, S.; Solaraj, G.

    2012-01-01

    Coimbatore is one of the fast growing industrial cities of Southern India with an urban population of 1.9 million. This study attempts to evaluate the trends of airborne fine particulates (PM 2.5) and polyaromatic hydrocarbons (PAH) on them. The PM 2.5 mass was collected in polytetra fluoroethylene filters using fine particulate sampler at monthly intervals during March 2009 to February 2010. PAHs were extracted from PM 2.5 and estimated by high-performance liquid chromatography. It is alarming to note that PM 2.5 values ranged between 27.85 and 165.75 μg/m3 and exceeded the air quality standards in many sampling events. The sum of 9 PAHs bound to PM 2.5 in a single sampling event ranged from 4.1 to 1632.3 ng/m3. PAH diagnostic ratios and principal component analysis results revealed vehicular emissions and diesel-powered generators as predominant sources of PAH in Coimbatore. PMID:22649329

  20. Polycyclic aromatic hydrocarbons in Haliotis tuberculata (Linnaeus, 1758) (Mollusca, Gastropoda): Considerations on food safety and source investigation.

    PubMed

    Conte, Francesca; Copat, Chiara; Longo, Sabrina; Conti, Gea Oliveri; Grasso, Alfina; Arena, Giovanni; Dimartino, Angela; Brundo, Maria Violetta; Ferrante, Margherita

    2016-08-01

    Polycyclic aromatic hydrocarbons were analyzed in wild specimens of Haliotis tuberculata from three sites of the Sothern Ionian Sea. The species Ht is commonly found at these sites and has significant commercial value. Main results revealed mean values of benzo(a)pyrene higher than the threshold set by Regulation No. 835/2011/EU in all sampling sites and the sum of selected PAHs, expressed as ΣPAH4 by EC Regulation, were below the limit set by the same Regulation in ME and VSG. We found generally higher concentrations than literature finding, especially for low molecular weight PAHs, and results of diagnostic ratios highlighted both pyrolytic and petrogenic sources. The potential human health risks due consumption of Ht by local inhabitants have been assessed by exposure daily intake (EDI), target hazard quotient (THQ) and lifetime cancer risk (CR). EDI values were below the intake range reviewed by EFSA for each class of contaminant. BaP daily intake was below the value of 10 ng/Kg/day, suggested by JFCFA, and CRBaP was slightly higher than the acceptable risk level (ARL) of 1×10(-5). Conversely, target hazard quotient (THQ) resulted always below 1, thus the risk to develop chronic systemic effects due naphthalene, acenaphthene, fluorene, anthracene, fluoranthene and pyrene was low.

  1. Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from Zhanjiang Bay and Leizhou Bay, South China.

    PubMed

    Huang, Weixia; Wang, Zhiyuan; Yan, Wen

    2012-09-01

    The concentrations and spatial distribution of polycyclic aromatic hydrocarbons have been investigated in two adjacent bays of Zhanjiang and Leizhou, China. The total concentrations of the 16 USEPA priority PAHs were ranged from 41.96 to 933.90 ng/g dry weight with an average concentration of 315.98 ng/g and ranged from 21.72 to 319.61 ng/g with an average concentration of 103.91 ng/g in Zhanjiang and Leizhou Bays, respectively. The spatial distribution of PAHs was site-specific and appeared to be somewhat positively correlated with TOC and negatively correlated with sediment grain size in the two bays. The values of Phe/Ant, BaA/228 and InP/276 were higher than 10, less than 0.2, and from 0.2 to 0.5, respectively, indicating that the sources of PAHs in the two bays were mainly from petroleum and its combustion, which predominantly originated from those ships and boats coming and going in the two bays.

  2. 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

  3. 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.

  4. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) into Central Park Lake, New York City, over a century of deposition.

    PubMed

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

    2014-05-01

    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.

  5. Distribution, compositional pattern and sources of polycyclic aromatic hydrocarbons in urban soils of an industrial city, Lanzhou, China.

    PubMed

    Jiang, Yufeng; Yves, Uwamungu J; Sun, Hang; Hu, Xuefei; Zhan, Huiying; Wu, Yingqin

    2016-04-01

    The level, distribution, compositional pattern and possible sources of polycyclic aromatic hydrocarbons (PAHs) in Lanzhou urban soil of Northwest China were investigated in this study. The total level of 22 PAHs ranged from 115 to 12,100 µg kg(-1) and that of 16 priority PAHs from 82.4 to 10,900 µg kg(-1). Seven carcinogenic PAHs generally accounted for 6.18-57.4% of total 22 PAHs. Compared with data from those reported about urban areas, PAH contamination in Lanzhou urban soils was moderate. Among different functional areas, higher level of PAHs was found along roadsides and in the industrial district (p<0.01), while lower levels were detected in the commercial, park and residential districts. The composition of PAHs was characterized by high molecular weight PAHs (≥4 rings), among which fluoranthene, benz[a]anthracene and phenanthrene were the most dominant components. Correlation analysis suggested that low molecular weight PAHs and high molecular weight PAHs originated from different sources and further corroborated that TOC was an important factor in the accumulation of PAHs in soil. Isomer ratios and principal component analysis indicated that PAHs in urban soil derived primarily from emissions resulting from the combustion of biomass, coal and petroleum products. Toxic equivalent concentrations (BaP(eq)) of soil PAHs ranged from 6.12 to 1302 µg BaP(eq) kg(-1), with a mean of 138 µg BaP(eq) kg(-1). The results suggested that human exposure to those soils which polluted by high concentrations of PAHs through direct ingestion or inhalation of suspended soil particles probably poses a significant risk to human health from the carcinogenic effects of PAHs.

  6. 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.

  7. 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. PMID:27314274

  8. 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

  9. Environmental carcinogenic polycyclic aromatic hydrocarbons in soil from Himalayas, India: Implications for spatial distribution, sources apportionment and risk assessment.

    PubMed

    Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra; Shihua, Qi; Dan, Yang; Zhang, Gan; Raha, Priyankar

    2016-02-01

    The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples (n = 69) collected from IHR were analysed for 16 priority polycyclic aromatic hydrocarbons (PAH) listed by USEPA. The ∑16PAH concentration in surface soil ranged from 15.3 to 4762 ngg(-1) (mean 458 ngg(-1)). The sum total of low molecular weight PAH (∑LMW-PAHs) (mean 74.0 ngg(-1)) were relatively lower than the high molecular weight PAH (∑HMW-PAHs) (mean 384 ngg(-1)). The concentration of eight carcinogenic PAHs (BaA, CHR, BbF, BkF, BaP, DahA, IcdP, BghiP) were detected high in mountain soil from IHR and ranged from 0.73 to 2729 ngg(-1) (mean 272 ngg(-1)). Based on spatial distribution map, high concentration of HMW- and LMW-PAHs were detected at GS1 site in Guwahati (615 and 4071 ngg(-1)), and lowest concentration of HMW-PAHs were found at IS6 in Itanagar (5.80 ngg(-1)) and LMW-PAHs at DS2 (17.3 ngg(-1)) in Dibrugarh. Total organic carbon (TOC) in mountain soil was poorly connected with ∑PAHs (r(2) = 0.072) and Car-PAHs (r(2) = 0.048), suggesting the little role of TOC in adsorption of PAHs. Isomeric ratio of PAHs showed the source of PAH contamination in IHR is mixed of petrogenic and pyrogenic origin and was affirmed by PAHs composition profile. These source apportionment results were further confirmed by principal component analysis (PCA). Eco-toxicological analysis showed the calculated TEQ for most carcinogenic PAH were 2-4 times more than the Dutch allowed limit, while TEQ of BaP was 25 times high, suggesting increasing trend of carcinogenicity of surface soil. PMID:26386774

  10. Environmental carcinogenic polycyclic aromatic hydrocarbons in soil from Himalayas, India: Implications for spatial distribution, sources apportionment and risk assessment.

    PubMed

    Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra; Shihua, Qi; Dan, Yang; Zhang, Gan; Raha, Priyankar

    2016-02-01

    The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples (n = 69) collected from IHR were analysed for 16 priority polycyclic aromatic hydrocarbons (PAH) listed by USEPA. The ∑16PAH concentration in surface soil ranged from 15.3 to 4762 ngg(-1) (mean 458 ngg(-1)). The sum total of low molecular weight PAH (∑LMW-PAHs) (mean 74.0 ngg(-1)) were relatively lower than the high molecular weight PAH (∑HMW-PAHs) (mean 384 ngg(-1)). The concentration of eight carcinogenic PAHs (BaA, CHR, BbF, BkF, BaP, DahA, IcdP, BghiP) were detected high in mountain soil from IHR and ranged from 0.73 to 2729 ngg(-1) (mean 272 ngg(-1)). Based on spatial distribution map, high concentration of HMW- and LMW-PAHs were detected at GS1 site in Guwahati (615 and 4071 ngg(-1)), and lowest concentration of HMW-PAHs were found at IS6 in Itanagar (5.80 ngg(-1)) and LMW-PAHs at DS2 (17.3 ngg(-1)) in Dibrugarh. Total organic carbon (TOC) in mountain soil was poorly connected with ∑PAHs (r(2) = 0.072) and Car-PAHs (r(2) = 0.048), suggesting the little role of TOC in adsorption of PAHs. Isomeric ratio of PAHs showed the source of PAH contamination in IHR is mixed of petrogenic and pyrogenic origin and was affirmed by PAHs composition profile. These source apportionment results were further confirmed by principal component analysis (PCA). Eco-toxicological analysis showed the calculated TEQ for most carcinogenic PAH were 2-4 times more than the Dutch allowed limit, while TEQ of BaP was 25 times high, suggesting increasing trend of carcinogenicity of surface soil.

  11. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the Eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Parinos, C.; Gogou, A.; Bouloubassi, I.; Pedrosa-Pàmies, R.; Hatzianestis, I.; Sànchez-Vidal, A.; Rousakis, G.; Velaoras, D.; Krokos, G.; Lykousis, V.

    2012-12-01

    Surface sediments collected from deep basins (22 stations, 1018-4087 m depth) of the Eastern Mediterranean Sea (EMS) were analyzed for aliphatic, triterpenoid and polycyclic aromatic hydrocarbons (PAHs) as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons (TAHC), n-alkanes (NA) and the Unresolved Complex Mixture (UCM) of aliphatic hydrocarbons ranged from 1.34 to 49.2 µg g-1, 145 to 4810 ng g-1 and 0.73 to 36.7 µg g-1, respectively, while total PAHs (TPAH25) concentrations ranged from 11.6 to 223 ng g-1. Molecular profiles of aliphatic hydrocarbons and PAHs reflect the contribution of both natural (epicuticular plant waxes) and anthropogenic (degraded petroleum products, unburned fossil fuels and combustion of petroleum, grass, wood and coal) compounds in deep EMS sediments, with hydrocarbon mixtures displaying significant regional variability. Hydrocarbon concentrations correlated significantly with the Total Organic Carbon (TOC) content of sediments, indicating that organic carbon exerts an important control on their transport and fate in the study area, while strong sub-basin and mesoscale variability of water masses also impact their regional characteristics. Major findings of this study support that deep basins/canyons of the EMS could act as traps of both natural and anthropogenic hydrocarbons.

  12. Polycyclic aromatic hydrocarbons associated with total suspended particles and surface soils in Kunming, China: distribution, possible sources, and cancer risks.

    PubMed

    Yang, Xiaoxia; Ren, Dong; Sun, Wenwen; Li, Xiaoman; Huang, Bin; Chen, Rong; Lin, Chan; Pan, Xuejun

    2015-05-01

    The concentrations, distribution, possible sources, and cancer risks of polycyclic aromatic hydrocarbons (PAHs) in total suspended particles (TSPs) and surface soils collected from the same sampling spots were compared in Kunming, China. The total PAH concentrations were 9.35-75.01 ng/m(3) and 101.64-693.30 ng/g dry weight (d.w.), respectively, in TSPs and surface soils. Fluoranthene (FLA), pyrene (PYR), chrysene (CHR), and phenanthrene (PHE) were the abundant compounds in TSP samples, and phenanthrene (PHE), fluorene (FLO), fluoranthene (FLA), benzo[b]fluoranthene (BbF), and benzo[g,h,i]perylene (BghiP) were the abundant compounds in surface soil samples. The spatial distribution of PAHs in TSPs is closely related to the surrounding environment, which varied significantly as a result of variations in source emission and changes in meteorology. However, the spatial distribution of PAHs in surface soils is supposed to correlate with a city's urbanization history, and high levels of PAHs were always observed in industry district, or central or old district of city. Based on the diagnostic ratios and principal component analysis (PCA), vehicle emissions (especially diesel-powered vehicles) and coal and wood combustion were the main sources of PAHs in TSPs, and the combustion of wood and coal, and spills of unburnt petroleum were the main sources of PAHs in the surface soils. The benzo[a]pyrene equivalent concentration (BaPeq) for the TSPs and surface soil samples were 0.16-2.57 ng/m(3) and 11.44-116.03 ng/g d.w., respectively. The incremental lifetime cancer risk (ILCR) exposed to particulate PAHs ranged from 10(-4) to 10(-3) indicating high potential of carcinogenic risk, and the ILCR exposed to soil PAHs was from 10(-7) to 10(-6) indicating virtual safety. These presented results showed that particle-bound PAHs had higher potential carcinogenic ability for human than soil PAHs. And, the values of cancer risk for children were always higher than for adults, which

  13. Storage and source of polycyclic aromatic hydrocarbons in sediments downstream of a major coal district in France.

    PubMed

    Bertrand, O; Mondamert, L; Grosbois, C; Dhivert, E; Bourrain, X; Labanowski, J; Desmet, M

    2015-12-01

    During the 20th century, the local economy of the Upper Loire Basin (ULB) was essentially based on industrial coal mining extraction. One of the major French coal districts with associated urban/industrial activities and numerous coking/gas plants were developed in the Ondaine-Furan subbasins, two tributaries of the upper Loire main stream. To determine the compositional assemblage, the level and the potential sources of contamination, the historical sedimentary chronicle of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) has been investigated. PAH concentrations were determined using gas chromatography/mass spectrometry (GC/MS) in a dated core, sampled in the Villerest flood-control reservoir located downstream of the Ondaine-Furan corridor (OFC). The most contaminated sediments were deposited prior to 1983 (Σ16PAHs ca. 4429-13,348 ng/g) and during flood events (Σ16PAHs ca. 6380 ng/g - 1996 flood; 5360 ng/g - 2003 flood; 6075 ng/g - 2008 flood), especially in medium and high molecular weight PAHs. Among them, typical pyrogenic PAHs such as FLT, PYR, BbF and BaP were prevalent in most of the core samples. In addition, some PAHs last decade data is available from the Loire Bretagne Water Agency and were analyzed using high-performance liquid chromatography with postcolumn fluorescence derivatization (HPLC/FLD). These results confirm that the most highly contaminated sediments were found downstream of OFC (Σ16PAHs ca. 2264-7460 ng/g). According to the observed molecular distribution, PAHs are originated largely from high-temperature pyrolytic processes. Major sources of pyrogenic PAHs have been emphasized by calculation of specific ratios and by comparison to reported data. Atmospheric deposition of urban and industrial areas, wood combustion and degraded coal tar derived from former factories of coking/gas plants seem to be the major pyrogenic sources. Specifically, particular solid transport conditions that can occur during major flood

  14. Storage and source of polycyclic aromatic hydrocarbons in sediments downstream of a major coal district in France.

    PubMed

    Bertrand, O; Mondamert, L; Grosbois, C; Dhivert, E; Bourrain, X; Labanowski, J; Desmet, M

    2015-12-01

    During the 20th century, the local economy of the Upper Loire Basin (ULB) was essentially based on industrial coal mining extraction. One of the major French coal districts with associated urban/industrial activities and numerous coking/gas plants were developed in the Ondaine-Furan subbasins, two tributaries of the upper Loire main stream. To determine the compositional assemblage, the level and the potential sources of contamination, the historical sedimentary chronicle of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) has been investigated. PAH concentrations were determined using gas chromatography/mass spectrometry (GC/MS) in a dated core, sampled in the Villerest flood-control reservoir located downstream of the Ondaine-Furan corridor (OFC). The most contaminated sediments were deposited prior to 1983 (Σ16PAHs ca. 4429-13,348 ng/g) and during flood events (Σ16PAHs ca. 6380 ng/g - 1996 flood; 5360 ng/g - 2003 flood; 6075 ng/g - 2008 flood), especially in medium and high molecular weight PAHs. Among them, typical pyrogenic PAHs such as FLT, PYR, BbF and BaP were prevalent in most of the core samples. In addition, some PAHs last decade data is available from the Loire Bretagne Water Agency and were analyzed using high-performance liquid chromatography with postcolumn fluorescence derivatization (HPLC/FLD). These results confirm that the most highly contaminated sediments were found downstream of OFC (Σ16PAHs ca. 2264-7460 ng/g). According to the observed molecular distribution, PAHs are originated largely from high-temperature pyrolytic processes. Major sources of pyrogenic PAHs have been emphasized by calculation of specific ratios and by comparison to reported data. Atmospheric deposition of urban and industrial areas, wood combustion and degraded coal tar derived from former factories of coking/gas plants seem to be the major pyrogenic sources. Specifically, particular solid transport conditions that can occur during major flood

  15. 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.

  16. 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. PMID:25604562

  17. Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in urban air particulates and their relationship to emission sources in the Pan-Japan Sea countries

    NASA Astrophysics Data System (ADS)

    Tang, Ning; Hattori, Tetsuyuki; Taga, Rina; Igarashi, Kazuhiko; Yang, Xiaoyang; Tamura, Kenji; Kakimoto, Hitoshi; Mishukov, Vasiliy F.; Toriba, Akira; Kizu, Ryoichi; Hayakawa, Kazuichi

    Airborne particulates were collected in seven cities in the Pan-Japan Sea countries, Shenyang (China), Vladivostok (Russia), Seoul (South Korea), Kitakyushu, Kanazawa, Tokyo and Sapporo (Japan), in winter and summer from 1997 to 2002. In addition, particulates from domestic coal-burning heaters and diesel engine automobiles were collected in Shenyang and Kanazawa, respectively. Nine polycyclic aromatic hydrocarbons (PAHs) and four nitropolycyclic aromatic hydrocarbons (NPAHs) in the extracts from the particulates were analysed by HPLC with fluorescence and chemiluminescence detections, respectively. The PAHs were fluoranthene, pyrene (Pyr), benz[ a]anthracene, chrysene, benzo[ b]fluoranthene, benzo[ k]fluoranthene, benzo[ a]pyrene, benzo[ ghi]perylene and indeno[1,2,3- cd]pyrene, and NPAHs were 1,3-, 1,6-, 1,8-dinitropyrenes, and 1-nitropyrene (1-NP). Mean atmospheric concentrations of PAHs in Shenyang and Vladivostok were substantially higher than those in Seoul, Tokyo, Sapporo, Kitakyushu and Kanazawa. However, the mean atmospheric concentrations of NPAHs were at the same levels in all cities except Kitakyushu. The expected seasonal variations (greater PAH and NPAH concentrations in winter than in summer) were observed in all cities. In order to study the major contributors of atmospheric PAHs and NPAHs, both cluster analysis and factor analysis were used and three large clusters were identified. Furthermore, the concentration ratios of 1-NP to Pyr were significantly smaller in Shenyang, Vladivostok and Kitakyushu and the values were close to those observed in particulates from coal stove exhaust. By contrast, in Seoul, Kanazawa, Tokyo and Sapporo the [1-NP]/[Pyr] ratio reached values similar to those of particulates released from diesel-engine automobiles. The [1-NP]/[Pyr] concentration ratio seemed to be a suitable indicator of the contribution made by diesel-engine vehicles and coal combustion to urban air particulates.

  18. 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. PMID:25173594

  19. 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

  20. Distributions and potential sources of polycyclic aromatic hydrocarbons in surface sediments from an emerging industrial city (Xinxiang).

    PubMed

    Feng, Jinglan; Xi, Nannan; Zhang, Fei; Zhao, Jiahui; Hu, Pengtuan; Sun, Jianhui

    2016-01-01

    To investigate the distributions, degree, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in bed sediments from four rivers of Xinxiang, 18 sediment samples were analyzed. The concentrations ranged from 4.45 × 10(3) to 29.0 × 10(3) ng/g for ∑15PAHs (sum of US Environmental Protection Agency (EPA) priority PAHs apart from naphthalene (Nap)) and 3.37 × 10(3) to 23.5 × 10(3) ng/g for ∑7carPAHs (including benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DBA), and indeno[1,2,3-cd]pyrene (InP)) with average concentrations of 10.7 × 10(3) and 7.99 × 10(3) ng/g, respectively. Compared with those from other rivers in China, sediments from four rivers of Xinxiang were severely polluted with PAHs. Pearson correlation analysis showed that ∑15PAHs concentrations had a significant positive correlation with black carbon content. Four- to six-ring PAHs accounted for 83.4 % of total PAHs, which indicated that the main source of PAHs in the studied area could be pyrogenic contamination. Source apportionment using PCA/MLR and UNMIX revealed that coal and biomass combustion contributed 64.4-67.1 %, gasoline vehicle 23.2-27.2 %, and diesel vehicle 5.70-12.4 % of the total PAHs, respectively. The effects range low/effects range median (ERL/ERM) values showed that there was a high level of toxicity risk for BaA. The ecological risk assessment by mean effects range median quotients (mERMQ) revealed a medium ecological risk of ∑15PAHs in sediments from four rivers of Xinxiang, manifesting that a close attention should be paid to pollution of PAHs in the studied area. PMID:26714501

  1. Application of Radiocarbon Analysis and Receptor Modeling to the Source Apportionment of Pahs (polycyclic Aromatic Hydrocarbons) in the Atmosphere.

    NASA Astrophysics Data System (ADS)

    Sheffield, Ann Elizabeth

    The radiocarbon tracer technique was used to demonstrate that polycyclic aromatic hydrocarbons (PAHs) can be used for quantitative receptor modeling of air pollution. Fine -particle samples were collected during December, 1985, in Albuquerque, NM. Motor vehicles (fossil) and residential wood combustion ("RWC," modern) were the major PAH-sources. For each sample, the PAH-fraction was solvent-extracted, isolated by liquid chromatography, and analyzed by GC-FID and GC -MS. The PAH-fractions from sixteen samples were analyzed for ^{14}C by Accelerator Mass Spectrometry. Samples contained from 37 to 470 mug C. Radiocarbon data were used to calculate the relative RWC contribution (f_{rm RWC} ) for samples analyzed for ^{14 }C. Normalized concentrations of a prospective motor vehicle tracer, benzo(ghi)perylene (BGP) had a strong, negative correlation with f_{rm RWC}. A strong, positive correlation was observed between f_{rm RWC} and the normalized values of "ADCS," defined as the sum of the concentrations of retene and the methyl esters of abietic and dehydroabietic acid. Normalized BGP concentrations were used to apportion sources for samples not analyzed for ^{14 }C. On average, RWC contributed ^ ~79% of the total PAHs observed at night. During the day, RWC contributed 47% of the total PAHs at an intersection site and 63% at a residential site. In a factor analysis of the PAH data, two factors accounted for >95% of the observed variance. Factor one, attributed to RWC, had high loadings of ADCS, 1,7-dimethylphenanthrene, and low-molecular-weight PAHs. Factor two, attributed to motor -vehicle emissions, had high loadings of heavier PAHs, including BGP. When the daytime samples were subjected to a separate factor analysis, a third factor with loadings of volatile PAHs only was observed. Multiple Linear Regression (MLR) vs. ADCS and BGP was used to estimate source profiles for use in Target Factor Analysis (TFA). Profiles predicted by TFA were used in Chemical Mass Balances

  2. 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.

  3. Status, source and health risk assessment of polycyclic aromatic hydrocarbons in street dust of an industrial city, NW China.

    PubMed

    Jiang, Yufeng; Hu, Xuefei; Yves, Uwamungu J; Zhan, Huiying; Wu, Yingqin

    2014-08-01

    The status, source and health risk of street-dust-borne polycyclic aromatic hydrocarbons (PAHs) in Lanzhou of Northwest China were investigated. The total level of the 21 PAHs ranged from 1470 to 13,700 µg kg(-1) and that of the 16 priority PAHs from 1240 to 10,700 µg kg(-1). Higher levels of PAHs were mainly distributed in the Chengguan and Qilihe districts at Lanzhou central areas, and the lower levels were in Anning and Xigu districts. The level of seven potential carcinogenic PAHs generally accounted for 35-40 percent of total PAHs, and the PAHs contained two to four rings, mainly phenanthrene, benzo[b]fluoranthene and fluoranthene. The total level of PAHs increased with the decreasing particle size in the street dust. The correlation analysis suggested that the total organic carbon (TOC) was only slightly affected the PAH accumulation in street dust. The isomer ratios and principal component analysis indicated that the dust-borne PAHs in the dust were derived primarily from the combustion of biomass, coal and petroleum emission. The toxic equivalent concentrations (BaP(eq)) of dust-borne PAHs ranged from 115 to 827 µg BaP(eq) kg(-1), with a mean of 300 µg BaP(eq) kg(-1). The 95 percent upper confidence limit of Incremental Lifetime Cancer Risk due to human exposure to urban surface dust-borne PAHs in Lanzhou urban area was 2.031 × 10(-6) for children and 1.935 × 10(-6) for adults.

  4. 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.

  5. 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.

  6. 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.

  7. Nitrogen availability, local light regime and leaf rank effects on the amount and sources of N allocated within the foliage of young walnut (Juglans nigra x regia) trees.

    PubMed

    Frak, Ela; Le Roux, Xavier; Millard, Peter; Guillaumie, Sabine; Wendler, Renate

    2006-01-01

    Early season leaf growth depends largely on nitrogen (N) provided by remobilization from storage, and many studies have tested the effect of N availability to roots on the amount of N provided for new leaf development by remobilization. Although it is well known that the light regime experienced by a leaf influences the amount of N per unit leaf area (LA), the effect of the local light regime on the amount of N derived either directly from root uptake or from remobilization for early season leaf growth has never been tested at an intra- canopy scale. The objective of this study was to quantify the relative importance of (1) N availability to roots, (2) local light regime experienced by the foliage (at the shoot scale) and (3) leaf rank along the shoot, on the total amount of N allocated to leaves and on the proportions of N provided by remobilization and root uptake. To quantify the importance of N uptake and remobilization as sources of leaf N, potted hybrid walnut trees (Juglans nigra L. x regia L.) were grown outdoors in sand and fed with a labeled ((15)N) nutrient solution. By removing the apical bud, the trees were manipulated to produce only two shoots. The experimental design had two factors: (1) high (HN; 8 mol N m(-3)) and low (LN; 2 mol N m(-3)) N availability; and (2) high (HL; 90% of incident photosynthetically active photon flux (PPF)) and low (LL; 10% of incident PPF) light. Total leaf N per tree was unaffected by either N availability or irradiance. The HN treatment increased the amount of leaf N derived from root uptake at the whole-tree scale (typically around 8 and 2% in the HN and LN treatments, respectively). Nitrogen allocation within foliage of individual trees was controlled by the local light regime, which strongly affected individual leaf characteristics as leaf mass per unit LA and area- based amount of leaf (N(a)). Decreasing the light availability to a branch decreased the amount of N allocated to it, benefiting the less shaded branches

  8. 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

  9. 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.

  10. Integrated magnetic, gravity, and GPR surveys to locate the probable source of hydrocarbon contamination in Sharm El-Sheikh area, south Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Morsy, Mona; Rashed, Mohamed

    2013-01-01

    Sharm El-Sheikh waters were suddenly hit by hydrocarbon spills which created a serious threat to the prosperous tourism industry in and around the city. Analysis of soil samples, water samples, and seabed samples collected in and around the contaminated bay area showed anomalous levels of hydrocarbons. An integrated geophysical investigation, using magnetic, gravity, and ground penetrating radar geophysical tools, was conducted in the headland overlooking the contaminated bay in order to delineate the possible subsurface source of contamination. The results of the geophysical investigations revealed three underground manmade reinforced concrete tanks and a complicated network of buried steel pipes in addition to other unidentified buried objects. The depths and dimensions of the discovered objects were determined. Geophysical investigations also revealed the presence of a north-south oblique slip fault running through the eastern part of the studied area. Excavations, conducted later on, confirmed the presence of one of the tanks delineated by the geophysical surveys.

  11. 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

  12. [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% PMID:27548947

  13. 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 ...

  14. 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...

  15. Combination of Unmix and positive matrix factorization model identifying contributions to carcinogenicity and mutagenicity for polycyclic aromatic hydrocarbons sources in Liaohe delta reed wetland soils, China.

    PubMed

    Lang, Yin-Hai; Li, Guo-Liang; Wang, Xiao-Mei; Peng, Peng; Bai, Jie

    2015-02-01

    Surface soils were collected from Liaohe delta, China, the largest reed wetland in the world dominated by common reed (Phragmites australis). Samples were analyzed for sixteen priority polycyclic aromatic hydrocarbons (PAHs) by GC/MS. The potential source patterns and source contributions to seven carcinogenic PAH congeners were performed by combining of Unmix and positive matrix factorization (PMF) model with the formula of toxic equivalent quantity (TEQ BaP) and mutagenic equivalent quantity (MEQ BaP), respectively. Four source categories, including petrogenic source, biomass burning, diesel emission and coal combustion, were identified by Unmix and PMF models. For both Unmix and PMF model, the mixed sources (gasoline and diesel engine emission) contributed the most to the TEQ BaP and MEQ BaP, while petrogenic source, the largest contributor for PAHs, made lower contribution to TEQ BaP and MEQ BaP. Minor source contribution difference was found between two models, which might be attributed to uncertainties model parameters and species variables. Hence, it is very essential to use combined source apportionment techniques for quantitatively identifying PAHs sources and estimated their carcinogenicity and mutagenicity. PMID:25217882

  16. Combination of Unmix and positive matrix factorization model identifying contributions to carcinogenicity and mutagenicity for polycyclic aromatic hydrocarbons sources in Liaohe delta reed wetland soils, China.

    PubMed

    Lang, Yin-Hai; Li, Guo-Liang; Wang, Xiao-Mei; Peng, Peng; Bai, Jie

    2015-02-01

    Surface soils were collected from Liaohe delta, China, the largest reed wetland in the world dominated by common reed (Phragmites australis). Samples were analyzed for sixteen priority polycyclic aromatic hydrocarbons (PAHs) by GC/MS. The potential source patterns and source contributions to seven carcinogenic PAH congeners were performed by combining of Unmix and positive matrix factorization (PMF) model with the formula of toxic equivalent quantity (TEQ BaP) and mutagenic equivalent quantity (MEQ BaP), respectively. Four source categories, including petrogenic source, biomass burning, diesel emission and coal combustion, were identified by Unmix and PMF models. For both Unmix and PMF model, the mixed sources (gasoline and diesel engine emission) contributed the most to the TEQ BaP and MEQ BaP, while petrogenic source, the largest contributor for PAHs, made lower contribution to TEQ BaP and MEQ BaP. Minor source contribution difference was found between two models, which might be attributed to uncertainties model parameters and species variables. Hence, it is very essential to use combined source apportionment techniques for quantitatively identifying PAHs sources and estimated their carcinogenicity and mutagenicity.

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

    SciTech Connect

    Miller, R.N.

    1990-01-01

    Soil venting is effective for the physical removal of volatile hydrocarbons from unsaturated soils, and is also effective as a source of oxygen for biological degradation of the volatile and non-volatile fractions of hydrocarbons in contaminated soil. Treatment of soil venting off-gas is expensive, constituting a minimum of 50% of soil venting remediation costs. In this research, methods for enhancing biodegradation through soil venting were investigated, with the goal of eliminating the need for expensive off-gas treatment. A seven-month field investigation was conducted at Tyndall Air Force Base (AFB), Florida, where past jet fuel storage had resulted in contamination of a sandy soil. The contaminated area was dewatered to maintain approximately 1.6 meters of unsaturated soil. Soil hydrocarbon concentrations ranged from 30 to 23,000 mg/kg. Contaminated and uncontaminated test plots were vented for 188 days. Venting was interrupted five times during operation to allow for measurement of biological activity (CO{sub 2} production and O{sub 2} consumption) under varying moisture and nutrient conditions.

  18. Nitrogen incorporation in saturated aliphatic C6-C8 hydrocarbons and ethanol in low-pressure nitrogen plasma generated by a hollow cathode discharge ion source.

    PubMed

    Usmanov, Dilshadbek T; Chen, Lee Chuin; Hiraoka, Kenzo; Wada, Hiroshi; Nonami, Hiroshi; Yamabe, Shinichi

    2016-06-01

    Ion/molecule reactions of saturated hydrocarbons (n-hexane, cyclohexane, n-heptane, n-octane and isooctane) in 28-Torr N2 plasma generated by a hollow cathode discharge ion source were investigated using an Orbitrap mass spectrometer. It was found that the ions with [M+14](+) were observed as the major ions (M: sample molecule). The exact mass analysis revealed that the ions are nitrogenated molecules, [M+N](+) formed by the reactions of N3 (+) with M. The reaction, N3 (+) + M → [M+N](+) + N2 , were examined by the density functional theory calculations. It was found that N3 (+) abstracts the H atom from hydrocarbon molecules leading to the formation of protonated imines in the forms of R'R″CNH2 (+) (i.e. C-H bond nitrogenation). This result is in accord with the fact that elimination of NH3 is the major channel for MS/MS of [M+N](+) . That is, nitrogen is incorporated in the C-H bonds of saturated hydrocarbons. No nitrogenation was observed for benzene and acetone, which was ascribed to the formation of stable charge-transfer complexes benzene⋅⋅⋅⋅N3 (+) and acetone⋅⋅⋅⋅N3 (+) revealed by density functional theory calculations. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27270868

  19. Carbon allocation from source to sink leaf tissue in relation to flavonoid biosynthesis in variegated Pelargonium zonale under UV-B radiation and high PAR intensity.

    PubMed

    Vidović, Marija; Morina, Filis; Milić, Sonja; Albert, Andreas; Zechmann, Bernd; Tosti, Tomislav; Winkler, Jana Barbro; Jovanović, Sonja Veljović

    2015-08-01

    We studied the specific effects of high photosynthetically active radiation (PAR, 400-700 nm) and ecologically relevant UV-B radiation (0.90 W m(-2)) on antioxidative and phenolic metabolism by exploiting the green-white leaf variegation of Pelargonium zonale plants. This is a suitable model system for examining "source-sink" interactions within the same leaf. High PAR intensity (1350 μmol m(-2) s(-1)) and UV-B radiation induced different responses in green and white leaf sectors. High PAR intensity had a greater influence on green tissue, triggering the accumulation of phenylpropanoids and flavonoids with strong antioxidative function. Induced phenolics, together with ascorbate, ascorbate peroxidase (APX, EC 1.11.1.11) and catalase (CAT, EC 1.11.1.6) provided efficient defense against potential oxidative pressure. UV-B-induced up-regulation of non-phenolic H2O2 scavengers in green leaf sectors was greater than high PAR-induced changes, indicating a UV-B role in antioxidative defense under light excess; on the contrary, minimal effects were observed in white tissue. However, UV-B radiation had greater influence on phenolics in white leaf sections compared to green ones, inducing accumulation of phenolic glycosides whose function was UV-B screening rather than antioxidative. By stimulation of starch and sucrose breakdown and carbon allocation in the form of soluble sugars from "source" (green) tissue to "sink" (white) tissue, UV-B radiation compensated the absence of photosynthetic activity and phenylpropanoid and flavonoid biosynthesis in white sectors. PMID:25661975

  20. Carbon allocation from source to sink leaf tissue in relation to flavonoid biosynthesis in variegated Pelargonium zonale under UV-B radiation and high PAR intensity.

    PubMed

    Vidović, Marija; Morina, Filis; Milić, Sonja; Albert, Andreas; Zechmann, Bernd; Tosti, Tomislav; Winkler, Jana Barbro; Jovanović, Sonja Veljović

    2015-08-01

    We studied the specific effects of high photosynthetically active radiation (PAR, 400-700 nm) and ecologically relevant UV-B radiation (0.90 W m(-2)) on antioxidative and phenolic metabolism by exploiting the green-white leaf variegation of Pelargonium zonale plants. This is a suitable model system for examining "source-sink" interactions within the same leaf. High PAR intensity (1350 μmol m(-2) s(-1)) and UV-B radiation induced different responses in green and white leaf sectors. High PAR intensity had a greater influence on green tissue, triggering the accumulation of phenylpropanoids and flavonoids with strong antioxidative function. Induced phenolics, together with ascorbate, ascorbate peroxidase (APX, EC 1.11.1.11) and catalase (CAT, EC 1.11.1.6) provided efficient defense against potential oxidative pressure. UV-B-induced up-regulation of non-phenolic H2O2 scavengers in green leaf sectors was greater than high PAR-induced changes, indicating a UV-B role in antioxidative defense under light excess; on the contrary, minimal effects were observed in white tissue. However, UV-B radiation had greater influence on phenolics in white leaf sections compared to green ones, inducing accumulation of phenolic glycosides whose function was UV-B screening rather than antioxidative. By stimulation of starch and sucrose breakdown and carbon allocation in the form of soluble sugars from "source" (green) tissue to "sink" (white) tissue, UV-B radiation compensated the absence of photosynthetic activity and phenylpropanoid and flavonoid biosynthesis in white sectors.

  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. 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

  3. Fatty acid and hydroxy acid adaptation in three gram-negative hydrocarbon-degrading bacteria in relation to carbon source.

    PubMed

    Soltani, Mohamed; Metzger, Pierre; Largeau, Claude

    2005-12-01

    The lipids of three gram-negative bacteria, Acinetobacter calcoaceticus, Marinobacter aquaeolei, and Pseudomonas oleovorans grown on mineral media supplemented with ammonium acetate or hydrocarbons, were isolated, purified, and their structures determined. Three pools of lipids were isolated according to a sequential procedure: unbound lipids extracted with organic solvents, comprising metabolic lipids and the main part of membrane lipids, OH--labile lipids (mainly ester-bound in the lipopolysaccharides, LPS) and H+-labile lipids (mainly amide-bound in the LPS). Unsaturated FA composition gave evidence for an aerobic desaturation pathway for the synthesis of these acids in A. calcoaceticus and M. aquaeolei, a nonclassic route in gram-negative bacteria. Surprisingly, both aerobic and anaerobic pathways are operating in the studied strain of P. oleovorans. The increase of the proportion of saturated FA observed for the strain of P. oleovorans grown on light hydrocarbons would increase the temperature transition of the lipids for maintaining the inner membrane fluidity. An opposite phenomenon occurs in A. calcoaceticus and M. aquaeolei grown on solid or highly viscous C19 hydrocarbons. The increases of FA < C18 when the bacteria were grown on n-nonadecane, or of iso-FA in cultures on isononadecane would decrease the transition temperature of the lipids, to maintain the fluidity of the inner membranes. Moreover, P. oleovorans grown on hydrocarbons greatly decreases the proportion of P-hydroxy acids of LPS, thus likely maintaining the physical properties of the outer membrane. By contrast, no dramatic change in hydroxy acid composition occurred in the other two bacteria. PMID:16477811

  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. Source Apportionment of Polycyclic Aromatic Hydrocarbons in Central European Soils with Compound-Specific Triple Isotopes (δ(13)C, Δ(14)C, and δ(2)H).

    PubMed

    Bosch, Carme; Andersson, August; Kruså, Martin; Bandh, Cecilia; Hovorková, Ivana; Klánová, Jana; Knowles, Timothy D J; Pancost, Richard D; Evershed, Richard P; Gustafsson, Örjan

    2015-07-01

    This paper reports the first study applying a triple-isotope approach for source apportionment of polycyclic aromatic hydrocarbons (PAHs). The (13)C/(12)C, (14)C/(12)C, and (2)H/(1)H isotope ratios of PAHs were determined in forest soils from mountainous areas of the Czech Republic, European Union. Statistical modeling applying a Bayesian Markov chain Monte Carlo (MCMC) framework to the environmental triple isotope PAH data and an end-member PAH isotope database allowed comprehensive accounting of uncertainties and quantitative constraints on the PAH sources among biomass combustion, liquid fossil fuel combustion, and coal combustion at low and high temperatures. The results suggest that PAHs in this central European region had a clear predominance of coal combustion sources (75 ± 6%; uncertainties represent 1 SD), mainly coal pyrolysis at low temperature (∼650 °C; 61 ± 8%). Combustion of liquid fossil fuels and biomass represented 16 ± 3 and 9 ± 3% of the total PAH burden (∑PAH14), respectively. Although some soils were located close to potential PAH point sources, the source distribution was within a narrow range throughout the region. These observation-based top-down constraints on sources of environmental PAHs provide a reference for both improved bottom-up emission inventories and guidance for efforts to mitigate PAH emissions. PMID:26053501

  6. 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. PMID:25981936

  7. 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.

  8. Evaluation of the hydrocarbon source-rock potential of carbonaceous shales; Upper Devonian shales of the Appalachian Basin

    SciTech Connect

    Curtis, J.B. Jr.

    1989-01-01

    This study investigated the organic matter contained in the Lower Huron Member of the Ohio Shale Formation and the Rhinestreet Shale Member of the West Falls Formation (Devonian) in Kentucky, Ohio, West Virginia, and Virginia. The organic matter in these formations is predominantly marine in origin, and was most probably derived from algal organisms. The preservation of the organic matter was apparently controlled by the existence of a set of fault-bounded basins associated with the Rome Trough. These basins were anoxic because of limited oxygen recharge by circulating waters. Preservation of organic matter was also enhanced by periodic blooms of the alga Tasnmanites and similar organisms in the waters above the local basins during both Lower Huron and Rhinestreet times. These blooms created such large concentrations of organic matter that the supply of molecular oxygen was exhausted and the preservation of the algal material was enhanced. The temperature dose measured by the reflectance of vitrinite particles was corrected for depth effects in order to identify areas where the rocks had been heated in excess of the normal geothermal gradient. Corrected Vitrinite Temperatures were used to identify those areas where more localized heat pulses have occurred. These heat pulses may have been caused by hot brines circulating from depth through fractures in the affected rocks. The enhanced permeability of the fractures results in anomalously high, present-day heat flow values, and production of hydrocarbon liquids. A significant negative correlation was identified between the vitrinite reflectance temperature, an integrated measure of the thermal history of a rock, and the hydrogen index, a measure of the remaining hydrocarbon potential of kerogen.

  9. Identifications and seasonal variations of sources of polycyclic aromatic hydrocarbons (PAHs) in the Yangtze River Estuary, China.

    PubMed

    Yu, Wenwen; Liu, Ruimin; Xu, Fei; Men, Comg; Shen, Zhenyao

    2016-03-15

    In this study, positive matrix factorization models (PMFx) were used to analyze the sources of sedimentary PAHs in Yangtze River Estuary (YRE) using 120 data samples from 30 sites collected over four seasons. Three sources were defined for the PAHs: coal and gasoline combustion was the dominant source, accounting for approximately 50%; coke plant emissions and wood or grass combustion each contributed approximately 25%. The coal tar origin was the major source in summer; wood or grass combustion dominated in autumn; coal combustion was the primary source of PAHs in spring and winter. More than 90% of the coke plant emissions were from summer, while pollutants from wood or grass combustion were discharged primarily in autumn. These three sources distributed in different primary regions, the spatial patterns of coal combustion presented an increasing trend in the seaward direction. PMID:26837271

  10. Geologic methane as a source for post-glacial CO[sub 2] increases: The hydrocarbon pump hypothesis

    SciTech Connect

    Loehle, C. )

    1993-07-23

    This paper looks at the question of whether geologic sources of methane could have served as the source for the carbon dioxide increases observed at each of the last two glacial-interglacial periods. Methane clathrates and natural gas emissions could serve as two possible geologic sources. The author looks at whether such sources could possibly produce the CO[sub 2] increases observed, in the time frames they occured in. The rates seem possible. The isotopic composition of the carbon dioxide increases is also examined to see if such sources could be ruled out. At present there appears to be no solid evidence to rule out such a geologic source, but additional research needs to be undertaken to better elucidate this question.

  11. An evaluation of background levels and sources of polycyclic aromatic hydrocarbons in naturally spawned embryos of Pacific herring (Clupea pallasii) from Puget Sound, Washington, USA.

    PubMed

    West, James E; O'Neill, Sandra M; Ylitalo, Gina M; Incardona, John P; Doty, Daniel C; Dutch, Margaret E

    2014-11-15

    Pacific herring embryos spawned in nearshore habitats may be exposed to toxic contaminants as they develop, from exogenous sources in spawning habitats and from maternal transfer. Determining baseline concentrations of these toxic contaminants is important for evaluating the health of this species, especially during this sensitive life stage. In this study we compared concentrations of polycyclic aromatic hydrocarbons, or PAHs, in naturally spawned herring embryos from five spawning areas across Puget Sound. The summed values of 31 PAH analytes (Σ31PAH) in early- to late-stage development embryos ranged from 1.1 to 140 ng/g, wet weight. Σ31PAH concentrations increased with development time in embryos from one spawning area where the greatest concentrations were observed, and the relative abundance of PAH chemicals in late-stage embryos was similar to those in nearby sediments, suggesting accumulation from local environmental sources. PAHs in both sediments and late-stage embryos appeared to exhibit a pyrogenic pattern. Although maternal transfer of PAHs appeared to be a negligible source to embryos in spawning areas with the greatest embryo PAH concentrations, maternal transfer may have been the dominant source in embryos from spawning areas where the lowest levels of embryo-PAHs occurred. Chronic embryo mortality has been reported in spawning habitats where we observed the greatest concentration of PAHs in embryos, and necrotic tissue in herring embryos from one such location was similar in description to phototoxic PAH necrosis reported elsewhere for embryonic zebrafish.

  12. 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.

  13. 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

  14. 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.

  15. Report on Tribal Priority Allocations.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    As part of Bureau of Indian Affairs (BIA) funding, Tribal Priority Allocations (TPA) are the principal source of funds for tribal governments and agency offices at the reservation level. According to their unique needs and circumstances, tribes may prioritize funding among eight general categories: government, human services, education, public…

  16. 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.

  17. Spatial characteristics and major sources of polycyclic aromatic hydrocarbons from soil and respirable particulate matter in a mega-city, China.

    PubMed

    Fu, Shan; Yang, Zhong-Zhi; Li, Ke; Xu, Xiao-Bai

    2010-07-01

    As one of China's great metropolises, Taiyuan is generally recognized to be one of the most polluted cities from polycyclic aromatic hydrocarbons (PAHs) in the world. Therefore, this study was conducted to determine a total of 16 PAH concentrations in various environmental media in Taiyuan. The total PAHs concentration ranged from 1.0 to 26 microg g(-1) in soil, 1.2 x 10(2) to 1.4 x 10(3) ng m(-3) in PM 2.5 and 76 to 1.1 x 10(3) ng m(-3) in PM 10, respectively. Furthermore, the primary source of PAHs was coal combustion, but the samples were also affected to varying degrees by traffic emissions.

  18. 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.

  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. 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

  1. 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.

  2. Reactions of o-benzyne with propargyl and benzyl radicals: potential sources of polycyclic aromatic hydrocarbons in combustion.

    PubMed

    Matsugi, Akira; Miyoshi, Akira

    2012-07-21

    The kinetics and mechanisms of the reactions of o-benzyne with propargyl and benzyl radicals have been investigated computationally. The possible reaction pathways have been explored by quantum chemical calculations at the M06-2X/6-311+G(3df,2p)//B3LYP/6-311G(d,p) level and the mechanisms have been investigated by the Rice-Ramsperger-Kassel-Marcus theory/master-equation calculations. It was found that the o-benzyne associates with the propargyl and benzyl radicals without pronounced barriers and the activated adducts easily isomerize to five-membered ring species. Indenyl radical and fluorene + H were predicted to be dominantly produced by the reactions of o-benzyne with propargyl and benzyl radicals, respectively, with the rate constants close to the high-pressure limits at temperatures below 2000 K. The related reactions on the two potential energy surfaces, namely, the reaction between fulvenallenyl radical and acetylene and the decomposition reactions of indenyl and α-phenylbenzyl radicals were also investigated. The high reactivity of o-benzyne toward the resonance stabilized radicals suggested a potential role of o-benzyne as a precursor of polycyclic aromatic hydrocarbons in combustion.

  3. Daytime resolved analysis of polycyclic aromatic hydrocarbons in urban aerosol samples - impact of sources and meteorological conditions.

    PubMed

    Sklorz, Martin; Schnelle-Kreis, Jürgen; Liu, Yongbo; Orasche, Jürgen; Zimmermann, Ralf

    2007-03-01

    Urban aerosol was collected in a summer and a winter campaign for 7 and 3 days, respectively. Low volume samples were taken with a time resolution of 160 min using a filter/sorption cartridge system extended by an ozone scrubber. Concentrations of mainly particle associated polycyclic aromatic hydrocarbons (PAH) and oxidised PAH (O-PAH) were determined by gas chromatography/high resolution mass spectrometry. The sampling site was located in the city centre of Augsburg, Germany, near major roads with high traffic volume. The daily concentrations and profiles were mainly governed by local emissions from traffic and domestic heating, as well as by the meteorological conditions. During the winter campaign, concentrations were more than 10 fold higher than during the summer campaign. Highest concentrations were found concurrent with low boundary layer heights and low wind speeds. Significant diurnal variation of the PAH profiles was observed. Enhanced influences of traffic related PAH on the PAH profiles were evident during daytime in summer, whereas emissions from hot water generation and domestic heating were obvious during the night time of both seasons. A general idea about the global meteorological situation was acquired using back trajectory calculations (NOAA ARL HYSPLIT4). Due to high local emissions in combination with low air exchange during the two sampling campaigns, effects of mesoscale transport were not clearly observable.

  4. [Pollution characteristics and sources of polycyclic aromatic hydrocarbons in riparian soils along urban rivers of Wenzhou city].

    PubMed

    Zhou, Jie-Cheng; Bi, Chun-Juan; Chen, Zhen-Lou; Wang, Lu; Xu, Shi-Yuan; Pan, Qi

    2012-12-01

    Twenty one riparian soil samples along Jiushanwai River and Shanxia River of Wenzhou city were collected in August 2010 to investigate the pollution characteristics of polycyclic aromatic hydrocarbons (PAHs). The samples were extracted by an accelerated solvent extractor (ASE), purified by a purification column and determined by GC-MS. Results showed that the total concentrations of PAHs in the riparian soils ranged from 60.7 ng x g(-1) to 3 871.3 ng x g(-1), and the concentrations of sigma PAHs in soils along the Shanxia River were significantly lower than the levels along Jiushanwai River. The dominant compounds were 2 to 3 rings in the riparian soils along both rivers, which in average accounted for 62.47% - 72.51% in sigma PAHs. Compared with the PAHs concentrations in soils of other areas in the world, the riparian soils of the studied rivers were moderately polluted by PAHs, but the concentrations of BaP in three soil samples were much higher than the soil standard value of the former Soviet Union, which should be paid more attention. Based on the ratios of Ant/(Ant + Phe) and Fla/(Fla + Pyr) and principal component analysis results, PAHs in riparian soils of the studied rivers were mainly derived from both the petroleum and combustion.

  5. Use of the phenanthrene to benzo(e)pyrene ambient air ratio as an indicator for the source of polycyclic aromatic hydrocarbons

    SciTech Connect

    Germain, A.; Ringuette, S.; Tremblay, J.

    1994-12-31

    Polycyclic aromatic hydrocarbons (PAH) are emitted by many industrial, domestic and natural sources. In 1990, the principal sources of PAH for the Province of Quebec were primary aluminum smelters (858 t), residential heating with wood (162 t), forest fires (148 t) and transportation (33 t). A sampling program was developed to measure PAH levels in ambient air at different locations influenced by these sources. The highest concentrations of PAH in ambient air (470 ng/m{sup 3} geometric mean) were measured near primary aluminum smelters using Horizontal Stud Soederberg technology. Areas influences by wood heating (157 ng/m{sup 3} winter geometric mean) and transportation (80 ng/m{sup 3} geometric mean) had lower total PAH concentrations. Ratios of ambient air concentration for phenanthrene/benzo(e)pyrene were lower in samples collected in the surroundings of the primary aluminum smelters (7--14), whereas high ratios were observed for residential heating with wood and transportation (20--45). The use of this ratio was found to be a good indicator for PAH originating from primary aluminum smelters.

  6. 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

  7. Distribution, sources, and risks of polycyclic aromatic hydrocarbons in the surface sediments from 28 lakes in the middle and lower reaches of the Yangtze River region, China.

    PubMed

    Li, Shanying; Tao, Yuqiang; Yao, Shuchun; Xue, Bin

    2016-03-01

    As the largest polycyclic aromatic hydrocarbons (PAHs) emission country, China is suffering from severe PAHs pollution. Twenty-eight lakes in the middle and lower reaches of the Yangtze River region (MLYR), where numerous lakes are located in and play very important roles in the development of the local economy and society, were selected to investigate the levels and sources of the PAHs in this region and the related influence factors. Concentrations of the 16 PAHs (∑PAHs) in the sediments ranged from 221.0 to 2418.8 ng g(-1) (dry weight). The mean ∑PAHs was higher in the lower reaches than in the middle reaches. ∑PAHs in the sediments was positively correlated with the local gross domestic product (GDP), which implies that GDP was the key factor to affect the PAHs level in the sediments of study area. According to the composition of 16 PAHs, the 28 lakes were grouped into 3 clusters. Major PAHs sources for the three types of lakes were significantly different, which were biomass combustion, coal combustion, and vehicle/coal source, respectively. The total toxic benzo(a)pyrene equivalent (TEQ(carc)) of the carcinogenic PAHs in the sediments varied from 12.9 to 472.9 ng TEQ(carc) g(-1). Benzo(a)pyrene (BaP) and dibenzo(a,h)anthracene (DaA) were the two main contributors to total TEQ(carc).

  8. 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.

  9. [Distribution and sources of polycyclic aromatic hydrocarbons in sediments from rivers of Pearl River Delta and its nearby South China Sea].

    PubMed

    Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian; Zeng, Yong-Ping; Sheng, Guo-Ying; Fu, Jia-Mo

    2005-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are measured in surface sediments from rivers and estuary of Pearl River Delta and its nearby South China Sea. Total PAH concentration varied from 255.9 - 16 670.3 ng/g and a moderate to low level compare to relevant areas worldwide. The order of PAHs concentration in sediments was: rivers of Pearl River Delta > estuary > South China Sea, and the most significant PAH contamination was at Guangzhou channel of Zhujiang river. A decrease trend for PAHs concentration with distance from estuary to open sea can be sees in South China Sea. Coal and biomass combustion is the major source of PAHs in nearshore of South China Sea, and petroleum combustion is the main source of pyrolytic PAHs in rivers and estuary of Pearl River Delta according to PAHs diagnostic ratios. Petroleum PAHs are revealed have a high contribution to PAHs in Xijiang River, estuary and some stations in Zhujiang River. A comparison of data from study in 1997 with data from present study indicates that there is no clear change in the PAH concentration over time but the source of PAHs in Pearl River Delta have been change from a main coal combustion to petroleum combustion and being reflect in the sediments in rivers and estuary of Pearl River Delta where there have high sedimentation rate.

  10. Spatial and temporal distribution and sources of polycyclic aromatic hydrocarbons in sediments of Taihu Lake, eastern China.

    PubMed

    Tang, Zhi; Guo, Jianyang; Liao, Haiqing; Zhao, Xiaoli; Wu, Fengchang; Zhu, Yuanrong; Zhang, Liang; Giesy, John P

    2015-04-01

    Spatial and temporal distributions of concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and dated sediment core from Taihu Lake in eastern China were determined. The sum of concentrations of PAHs (sum of total 16 USEPA priority PAH (∑PAHs)) of the entire Taihu Lake ranged from 2.9 × 10(2) to 8.4 × 10(2) ng/g dry mass (dm). Concentrations of ∑PAHs in surface sediments near more urbanized regions of the lake shore were greater than those in areas more remote from the urban centers. Temporal trends in concentrations of ∑PAHs ranged from 5.1 × 10(2) to 1.5 × 10(3) ng/g dm, increasing from deeper layers to surface sediments with some fluctuations, especially in the past three decades after the inception of China's Reform and Opening Up Policy, in which China's economy and urbanization underwent rapid development. Forensic analysis of surface sediments indicates that PAHs originated primarily from combustion of grass/wood/coal except for the special function water area, which was most likely influenced by petroleum products of traveling vessels. Vertical profiles of relative concentrations of PAHs suggested that the contribution of lesser-molecular-weight PAHs was gradually decreasing, while due to the heavier consumption of petroleum products, the proportion of greater-molecular-weight PAHs was increasing. When assessed by use of the rather conservative, apparent effect threshold method, concentrations of ∑PAHs in sediments from most locations in Taihu Lake are predicted to pose little risk of harm to benthic invertebrates.

  11. 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. PMID:27266522

  12. 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.

  13. 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

  14. Understanding the Impacts of Land Uses on the Source Apportionment of Atmospheric Contamination By Polycyclic Aromatic Hydrocarbons throughout a Small State in the Northeast United States

    NASA Astrophysics Data System (ADS)

    Schifman, L. A.; Boving, T. B.

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous contaminants that enter the environment through combustion processes and are often found in higher concentration of urban areas. However, once released, these compounds can travel long distances via transport through the atmosphere and can be deposited on the landscape far away from their original source. This PAH deposition pattern can slowly lead to the diffuse contamination of whole landscapes. Since most of the air masses entering the northeastern United States originate from the Midwest where coal burning power plants are plentiful, several atmospheric pollutants are introduced to the region in addition to local sources. Here, atmospheric deposition of PAHs in six different locations throughout Rhode Island was measured using passive bulk-deposition samplers for 3 years. The data were analyzed statistically by principal component analysis and factor analysis to identify the source of contamination and respective apportionment. The data clearly show that an urban-to- rural gradient exists where deposition rates are significantly higher in urban areas (up to 12325 ng/d m2 ∑PAH) compared to rural areas (as low as 11 ng/d m2 ∑PAH) and also follow seasonal trends that show higher deposition rates in the fall and winter compared to the summer and spring time. Further, based on PAH source apportionment ratios, contamination origins differ spatially. For example, fossil fuel, coal, and vehicle combustion is present in all samples; however fossil fuel combustion is dominant in urban samples. In Rural areas biomass combustion is much more prevalent and is not as greatly represented in urban or suburban areas. Therefore, even in a small state such as Rhode Island airborne PAH contamination can be fingerprinted readily for different sampling areas, indicating that distant emission sources have a widespread impact on regional air quality.

  15. Polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs and oxygenated PAHs in ambient air of the Marseilles area (South of France): concentrations and sources.

    PubMed

    Albinet, Alexandre; Leoz-Garziandia, Eva; Budzinski, Hélène; Viilenave, Eric

    2007-10-01

    Ambient measurements (gas+particle phases) of 15 polycyclic aromatic hydrocarbons (PAHs), 17 nitrated PAHs (NPAHs) and 9 oxygenated PAHs (OPAHs) were carried out during July 2004 on three different sites (urban, sub-urban and rural) in the region of Marseilles (South of France). Atmospheric concentrations of these classes of polyaromatics are great of interest because of their high potential mutagenicity and carcinogenicity. OPAH concentrations were of the same order of magnitude as those of PAHs while NPAH concentrations were one to two orders lower. 9-Fluorenone and 9,10-anthraquinone were the most abundant OPAHs, accounting for about 60% and 20% of the total OPAH concentration. Respectively 1-and 2-nitronaphthalene were the most abundant NPAHs and were accounting for about 30-50% and 15-30% of the total NPAH concentration. NPAHs and OPAHs concentration levels were consistent with the characteristics of the sampling sites. Study of source specific ratios (2-nitrofluoranthene/1-nitropyrene) clearly showed those primary NPAH sources influence the urban and sub-urban sites whereas production of secondary NPAHs by gas phase reactions was prevalent at the rural site. The study of NPAH and OPAH sources suggested that gasoline engines were an important source of such compounds Whereas the dominant source of 1-nitropyrene, 2-nitrofluorene, 6-nitrochrysene and benz[a]anthracene-7,12-dione seems to be diesel vehicles. Finally, 9,10-anthraquinone presents a double origin: primary diesel emission and photochemical processes. Formation of 9,10-anthraquinone from anthracene ozonation was shown at the rural site. Further investigations will be necessary in order to discriminate when (before or during the sampling) the OPAHs are formed. PMID:17590415

  16. Multimedia fate and source apportionment of polycyclic aromatic hydrocarbons in a coking industry city in Northern China.

    PubMed

    Wang, Y L; Xia, Z H; Liu, D; Qiu, W X; Duan, X L; Wang, R; Liu, W J; Zhang, Y H; Wang, D; Tao, S; Liu, W X

    2013-10-01

    A steady state Level III fate model was established and applied to quantify source-receptor relationship in a coking industry city in Northern China. The local emission inventory of PAHs, as the model input, was acquired based on energy consumption and emission factors. The model estimations were validated by measured data and indicated remarkable variations in the paired isomeric ratios. When a rectification factor, based on the receptor-to-source ratio, was calculated by the fate model, the quantitatively verified molecular diagnostic ratios provided reasonable results of local PAH emission sources. Due to the local ban and measures on small scale coking activities implemented from the beginning of 2004, the model calculations indicated that the local emission amount of PAHs in 2009 decreased considerably compared to that in 2003. PMID:23845769

  17. 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

  18. Distributions and sources of persistent organic pollutants (aliphatic hydrocarbons, PAHs, PCBs and pesticides) in surface sediments of an industrialized urban river (Huveaune), France.

    PubMed

    Kanzari, F; Syakti, A D; Asia, L; Malleret, L; Piram, A; Mille, G; Doumenq, P

    2014-04-15

    Surface sediments from the Huveaune River were analyzed for n-alkanes, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine and organophosphorous pesticides (OCs and OPs) by using gas chromatography-mass spectrometry (GC-MS). Concentrations of total alkanes ranged from 184 to 26,780 μg·kg(-1) sediment dry weight (dw) with a mean concentration of 6,126 ± 8,006 μg·kg(-1)dw, concentrations of total PAHs ranged from 572 to 4,235 μg·kg(-1)dw with a mean concentration of 1966 ± 1,104 μg·kg(-1) dw, concentrations of total PCB ranged from 2.8 to 435 μg·kg(-1)dw with a mean concentration of 148 ± 164 μg·kg(-1)dw and concentrations of total pesticides ranged from 0.07 to 1.25 μg·kg(-1)dw with a mean concentration of 1.23 ± 1.29 μg·kg(-1)dw. The spatial distribution of POPs reveals that pollutant concentration is relatively higher at the mouth of the river. The molecular indices of specific n-alkanes (CPI, NAR and TAR) and molecular indices of PAHs (Ant/(Ant+Phe), Fl/(Fl+Pyr), BaA/(BaA+Chry), IPyr/(Ipyr+BghiP)) were calculated to evaluate the possible sources of hydrocarbons. These molecular indices suggest mainly pyrolytic inputs which are markedly biogenic. All contaminant levels were also compared with Sediments Quality Guidelines (SQG) showing that the contamination levels in all stations were most of the time lower than their respective SQG. While, for PCBs, five stations (H5, H6, H7, H8 and H9) were higher than their effect range median (ERM) values which may indicate high potential toxicity of the sediment with probable adverse effects to the living biota.

  19. 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

  20. 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.

    2015-12-01

    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

  1. Computer Processor Allocator

    2004-03-01

    The Compute Processor Allocator (CPA) provides an efficient and reliable mechanism for managing and allotting processors in a massively parallel (MP) computer. It maintains information in a database on the health. configuration and allocation of each processor. This persistent information is factored in to each allocation decision. The CPA runs in a distributed fashion to avoid a single point of failure.

  2. Source origins, modeled profiles, and apportionments of halogenated hydrocarbons in the greater Pearl River Delta region, southern China

    NASA Astrophysics Data System (ADS)

    Guo, H.; Ding, A. J.; Wang, T.; Simpson, I. J.; Blake, D. R.; Barletta, B.; Meinardi, S.; Rowland, F. S.; Saunders, S. M.; Fu, T. M.; Hung, W. T.; Li, Y. S.

    2009-06-01

    We analyze 16-month data of 13 major halocarbons measured at a southern China coastal site in the greater Pearl River Delta (PRD). A total of 188 canister air samples were collected from August 2001 to December 2002. Overall inspection indicated that CH2Cl2, C2Cl4, and C2HCl3 had similar temporal variations while CFC-11, CFC-12, and CFC-113 showed the same emission patterns during the sampling period. Diurnal variations of halocarbons presented different patterns during ozone episode days, mainly related to emission strength, atmospheric dispersion, and photochemical lifetimes. For further statistics and source appointment, Lagrangian backward particle release simulations were conducted to help understand the potential source regions of all samples and classify them into different categories, including local Hong Kong, inner PRD, continental China, and marine air masses. With the exception of HCFC-142b, the mixing ratios of all halocarbons in marine air were significantly lower than those in urban and regional air (p < 0.01), whereas no significant difference was found between urban Hong Kong and inner PRD regional air, reflecting the dominant impact of the greater PRD regional air on the halocarbon levels. The halocarbon levels in this region were significantly influenced by anthropogenic sources, causing the halocarbon mixing ratios in South China Sea air to be higher than the corresponding background levels, as measured by global surface networks and by airborne missions such as Transport and Chemical Evolution Over the Pacific. Interspecies correlation analysis suggests that CHCl3 is mainly used as a solvent in Hong Kong but mostly as a feedstock for HCFC-22 in the inner PRD. Furthermore, CH3Cl is often used as a refrigerant and emitted from biomass/biofuel burning in the inner PRD. A positive matrix factorization receptor model was applied to the classified halocarbon samples in the greater PRD for source profiles and apportionments. Seven major sources were

  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. Roadside and rooftop measurements of polycyclic aromatic hydrocarbons in PM 2.5 in urban Guangzhou: Evaluation of vehicular and regional combustion source contributions

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Yu, Jian-Zhen; Li, Shu-Xian; Ding, Xiang; He, Quan-Fu; Wang, Xin-Ming

    2011-12-01

    Concurrent sampling of PM 2.5 aerosol at a roadside of heavy traffic (1.2 m above ground) and on a nearby rooftop (50 m above ground) was conducted at a same location in urban Guangzhou in September, October 2006 and January 2007. The samples were analyzed for eighteen polycyclic aromatic hydrocarbons (PAHs), together with major aerosol constituents and certain organic tracers for vehicular emissions (hopanes) and biomass burning (levoglucosan). Elemental carbon (EC) and hopanes were observed to be lower by 21-38% and 28-84%, respectively, at the rooftop than the roadside, confirming vehicular emissions as a significant local PM source. On the other hand, sulfate showed little vertical gradient, consistent with its secondary origin and its regional characteristics. The roadside-rooftop sample pairs have provided an opportunity in evaluating relative contributions of vehicular emissions and regional sources to ambient PAHs in this urban location. Concentrations of the total PAHs were ˜43% lower at rooftop in the September 2006 samples while they were at similar levels between rooftop and roadside in the October 2006 and January 2007 samples. Sources of PAHs were investigated through comparing ambient data of PAH isomer pairs and PAH/EC ratios with relevant source profiles including those of Guangzhou roadway tunnel emissions, rice straw/sugarcane leave combustion, and industrial coal combustion. The 4-ring PAHs such as pyrene and fluoranthene had a shift in their dominating source from vehicular emissions in September and October to regional combustion source in January. A few major 5- and 6-ring PAHs such as benzo[ghi]perylene and indeno[1,2,3-cd]pyrene were likely heavily influenced by regional biomass burning emissions in all three sampling months. Benzo(a)pyrene-equivalent carcinogenic potency (BaP eq) was calculated to evaluate the cancer risk of carcinogenic PAHs on the public. BaP eq levels in PM 2.5 were significantly higher at the roadside than those at

  5. Source apportionment and distribution of polycyclic aromatic hydrocarbons, risk considerations, and management implications for urban stormwater pond sediments in Minnesota, USA.

    PubMed

    Crane, Judy L

    2014-02-01

    High concentrations of polycyclic aromatic hydrocarbons (PAHs) are accumulating in many urban stormwater ponds in Minnesota, resulting in either expensive disposal of the excavated sediment or deferred maintenance by economically challenged municipalities. Fifteen stormwater ponds in the Minneapolis-St. Paul, MN, metropolitan area were studied to determine sources of PAHs to bed sediments through the application of several environmental forensic techniques, including a contaminant mass balance receptor model. The model results were quite robust and indicated that coal tar-based sealant (CT-sealant) particulate washoff and dust sources were the most important sources of PAHs (67.1%), followed by vehicle-related sources (29.5%), and pine wood combustion particles (3.4%). The distribution of 34 parent and alkylated PAHs was also evaluated regarding ancillary measurements of black carbon, total organic carbon, and particle size classes. None of these parameters were significantly different based on major land-use classifications (i.e., residential, commercial, and industrial) for pond watersheds. PAH contamination in three stormwater ponds was high enough to present a risk to benthic invertebrates, whereas nine ponds exceeded human health risk-based benchmarks that would prompt more expensive disposal of dredged sediment. The State of Minnesota has been addressing the broader issue of PAH-contaminated stormwater ponds by encouraging local municipalities to ban CT-sealants (29 in all) and to promote pollution prevention alternatives to businesses and homeowners, such as switching to asphalt-based sealants. A statewide CT-sealant ban was recently enacted. Other local and regional jurisdictions may benefit from using Minnesota's approach where CT-sealants are still used.

  6. 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

  7. 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. PMID:27215984

  8. 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.

  9. Vertical profile, sources, and equivalent toxicity of polycyclic aromatic hydrocarbons in sediment cores from the river mouths of Kaohsiung Harbor, Taiwan.

    PubMed

    Dong, Cheng-Di; Chen, Chih-Feng; Chen, Chiu-Wen

    2014-08-30

    Six sediment cores collected at four contaminated river mouths and two harbor entrances in Kaohsiung Harbor (Taiwan) were analyzed to evaluate the sources and potential toxicity of polycyclic aromatic hydrocarbons (PAHs). PAHs presented the wide variations ranging from 369±656 to 33,772±14,378 ng g(-1) at the six sampling sites. The composition of PAHs presented a uniform profile reflecting the importance of atmospheric input from vehicle exhausts or coal combustion in the river mouths. PAHs diagnostic ratios indicated a stronger influence of coal combustion in the Salt River mouth and the prevalence of petroleum combustion and mixed sources in the other rivers and harbor entrances. PAHs toxicity assessment using the mean effect range-median quotient (m-ERM-q: 0.011-1.804), benzo[a]pyrene-toxicity equivalent (TEQ(carc): 22-2819 ng TEQ g(-1)), and dioxin-toxicity equivalent (TEQ(fish): 37-5129 pg TEQ g(-1)) identified the Salt River mouth near the industrial area of the harbor as the most affected area.

  10. 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. PMID:27234513

  11. 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.

  12. 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.

  13. 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

  14. Evidence for an unrecognized secondary anthropogenic source of organosulfates and sulfonates: gas-phase oxidation of polycyclic aromatic hydrocarbons in the presence of sulfate aerosol.

    PubMed

    Riva, Matthieu; Tomaz, Sophie; Cui, Tianqu; Lin, Ying-Hsuan; Perraudin, Emilie; Gold, Avram; Stone, Elizabeth A; Villenave, Eric; Surratt, Jason D

    2015-06-01

    In the present study, formation of aromatic organosulfates (OSs) from the photo-oxidation of polycyclic aromatic hydrocarbons (PAHs) was investigated. Naphthalene (NAP) and 2-methylnaphthalene (2-MeNAP), two of the most abundant gas-phase PAHs and thought to represent "missing" sources of urban SOA, were photochemically oxidized in an outdoor smog chamber facility in the presence of nonacidified and acidified sulfate seed aerosol. Effects of seed aerosol composition, acidity and relative humidity on OS formation were examined. Chemical characterization of SOA extracts by ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry revealed the formation of OSs and sulfonates from photo-oxidation in the presence of sulfate seed aerosol. Many of the organosulfur compounds identified in the smog chamber extracts were also measured in urban fine aerosol collected at Lahore, Pakistan, and Pasadena, USA, demonstrating that PAH photo-oxidation in the presence of sulfate aerosol is a hitherto unrecognized source of anthropogenic secondary organosulfur compounds, and providing new PAH SOA tracers. PMID:25879928

  15. 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.

  16. 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

    2016-01-01

    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. PMID:27533870

  17. PM 10-bound polycyclic aromatic hydrocarbons: Concentrations, source characterization and estimating their risk in urban, suburban and rural areas in Kandy, Sri Lanka

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, A. P.; Karunaratne, D. G. G. P.; Sivakanesan, R.

    2011-05-01

    Kandy, a world heritage city, is a rapidly urbanized area in Sri Lanka, with a high population density of ˜6000 hab km -2. As it is centrally located in a small valley of 26 km 2 surrounded by high mountains, emissions from the daily flow of >100,000 vehicles, most are old and poorly maintained, get stagnant over the study area with an increased emphasis on the associated health impacts. Particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) are considered to be major pollutants in vehicular emissions; while PAHs account for the majority of mutagenic potency of PM. The purpose of the current study is to determine the 8 h average concentrations of ambient PM 10 PAHs at twenty sites distributed in the urban, suburban and rural Kandy. Samples on glass micro fibre filters were collected with a high volume air sampler from July/2008 to March/2009, prepared through standard procedures and analyzed for PAHs by high performance liquid chromatography with ultraviolet visible detection. Further, the type and strength of possible anthropogenic emission sources that cause major perturbations to the atmosphere were assessed by traffic volume (24 h) counts and firewood mass burnt/d at each sampling site, with the subsequent societal impact through quantitative cancer risk assessment. The results can serve as a base set to assess the PAH sources, pollution levels and human exposure. Mean total concentrations of 16 prioritized PAHs (∑PAHs) ranged from 57.43 to 1246.12 ng m -3 with 695.94 ng m -3 in urban heavy traffic locations (U/HT), 105.55 ng m -3 in urban light traffic locations, 337.45 ng m -3 in suburban heavy traffic stations, 154.36 ng m -3 in suburban light traffic stations, 192.48 ng m -3 in rural high firewood burning area and 100.31 ng m -3 in rural low firewood burning area. The mean PM 10 concentration was 129 μg m -3 (55-221 μg m -3); which is beyond the WHO air quality standards. Polycyclic aromatic hydrocarbon signature and the spatial variation

  18. 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.

  19. 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.

  20. 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.

  1. [Distribution, sources and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Yangtze estuary and Zhejiang coastal areas].

    PubMed

    Mu, Qing-Lin; Fang, Jie; Shao, Jun-Bo; Zhang, Qing-Hong; Wang, Xiao-Hua; Huang, Bei

    2015-03-01

    PAHs contents of surface sediments were tested from 62 sampling sites of the Yangtze River estuary and Zhejiang coastal zone in 2013. The results showed that: 16 kinds of PAHs, which are listed as priority pollutants by EPA, were found in all the samples. The total PAHs level (dry weight) reached 31. 8-384 μg x kg(-1) and the average amount was 131.1 μg x kg(-1). The distribution of PAHs was affected by terrigenous input and point source pollution, the high-value zones were found at 2# sampling site of the Yangtze River estuary and 21# sampling site of Ningbo. Compared with other sea areas, the survey sea area was at a low PAHs pollution level. PAHs were primarily tetracyclic or tricyclic, and source analysis showed that most of PAHs were originated from combustion of wood and coal. Based on the Sediment Quality Guidelines (SQGs), the assessment result showed that the PAHs content of surface sediments from survey sea area was at a relatively low level of ecological risk; While according to the assessment result of the Sediment Quality Standards (SQSs), PAHs pollution of surface sediments from survey sea area displayed an "Obviously negative ecological effect" to some extent, and some countermeasures are required to control and eliminate pollutions. PMID:25929049

  2. 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.

  3. 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.

  4. 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.

  5. [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.

  6. 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

  7. Distribution, Sources, and Potential Ecotoxicological Risk of Polycyclic Aromatic Hydrocarbons in Surface Sediments from Bahía Blanca Estuary, Argentina.

    PubMed

    Oliva, Ana L; Quintas, Pamela Y; La Colla, Noelia S; Arias, Andrés H; Marcovecchio, Jorge E

    2015-08-01

    Thirty-four surface sediment samples were collected from Bahía Blanca Estuary, Argentina, to evaluate polycyclic aromatic hydrocarbon (PAH) contamination and ecotoxicity risk by applying sediment-quality guidelines (SQGs) and toxic equivalent factors (TEQ). Total concentrations of 17 parent PAHs, including the 16 United States Environmental Protection Agency priority PAHs, were measured using gas chromatography-mass spectrometry, and their levels ranged from 19.7 to 30,054.5 ng/g dry weight. The greatest values were found near the urban/industrial core and decreasing as the distance from that site increased. Molecular ratios determined mixed sources of PAHs with a slight imposition of pyrolitic over the petrogenic inputs. The ecotoxicological evaluation, based on the SQG model, showed that some of the individual PAHs were in excess of the effects range low (ERL) and the effects range median's threshold; then, predicted occasional (ERL) and frequent adverse effects over the surrounding biota at the area of study were determined. Total PAH levels were expressed as benzo-a-pyrene TEQ and compared with literature data. PMID:26044929

  8. 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. PMID:20097001

  9. 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. PMID:22695981

  10. 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.

  11. 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

    2015-11-01

    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

  12. Characteristics, sources, and health risk of polycyclic aromatic hydrocarbons in urban surface dust: a case study of the city of Xi'an in Northwest China.

    PubMed

    Wang, Lijun; Wang, Li; Tao, Wendong; Smardon, Richard C; Shi, Xingmin; Lu, Xinwei

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. Urban surface dust is an important carrier of PAHs. To investigate the characteristics, sources, and health risk of PAHs in urban surface dust, this study collected urban surface dust samples from Xi'an, the largest city in Northwest China and one of the cities with severe smog occurrences in China. The total concentration of 16 US EPA priority PAHs (∑16PAHs) ranged from 5.0 to 48 mg/kg, with an average of 14 mg/kg. The seven carcinogenic PAHs accounted for 21 to 65 % of the ∑16PAHs. Higher levels of PAHs were found in its industrial, traffic, and mixed commercial and traffic districts. The PAHs were dominated by four-ring PAHs, and the predominant components were Fla, Phe, Chy, and Pyr. Multivariate statistical analyses showed that the PAHs originated mainly from the combustion of fossil fuel as well as coal and wood, and petroleum emission. The toxic equivalency quantities (TEQs) of urban surface dustborne PAHs ranged from 0.25 to 8.3 mg/kg, with a mean of 1.8 mg/kg. The 95 % upper confidence limit of incremental lifetime cancer risk (ILCR) due to human exposure to urban surface dustborne PAHs was 8.2 × 10(-5) for children and 7.3 × 10(-5) for adults. PMID:27026541

  13. 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.

  14. Polycyclic aromatic hydrocarbon and elemental carbon size distributions in Los Angeles aerosol: Source resolution and deposition velocities

    SciTech Connect

    Venkataraman, C.

    1992-01-01

    Particulate PAH size distributions for several species were measured, for the first time, at three ambient sites in Los Angeles. PAH size distributions in automobile exhaust were also measured by sampling aerosol in two traffic tunnels. A low flow impactor was used to minimize sampling losses in combination with a high resolution analysis method based on HPLC and fluorescence detection. Elemental carbon size distributions were measured using a thermal evolution method and flame ionization detection. Differences in ambient concentrations and size distributions are explained in terms of location within the basin, seasonal variations and differences in species reactivity and volatility. Differences between tunnel and ambient size distributions are explained in terms of gas to particle conversion. A particle morphology study confirmed that the structure of primary particles (0.05-0.5 [mu]m) is similar to soot agglomerates while the accumulation mode particles (0.5-1 [mu]m) are coated with a film of liquid aerosol. PAH profiles were estimated for the automobile source from the traffic tunnel measurements. These were used along with a characteristic PAH profile for meat cooking to apportion ambient aerosol PAH concentrations at Pico Rivera and Upland. Model estimates show that the Pico Rivera site is dominated by auto emissions which account for over 90% of all PAH (exception chrysene, 75%) and CO concentrations measured at the site. 61% of the EC concentration was explained by the model and attributed to auto emissions. In contrast, meat cooking operations contributed significantly (20 to 80%) to the concentrations of 2-4 ring PAH measured at Upland. The 5-ring and larger PAH were attributed to auto emissions at this site as well.

  15. Distribution of polycyclic aromatic hydrocarbons in the coastal region off Macao, China: assessment of input sources and transport pathways using compositional analysis.

    PubMed

    Mai, Bixian; Qi, Shihua; Zeng, Eddy Y; Yang, Qingshu; Zhang, Gan; Fu, Jiamo; Sheng, Guoying; Peng, Pingan; Wang, Zhishi

    2003-11-01

    The coastal region off Macao is a known depositional zone for persistent organic pollutants (POPs) in the Pearl River Delta and Estuary of southern China and an important gateway for the regional contributions of contamination to the globe. This paper presents a comprehensive assessment of the input sources and transport pathways of polycyclic aromatic hydrocarbons (PAHs) found in the coastal sediments of Macao, based on measurements of 48 2-7 ring PAHs and 7 sulfur/oxygenated (S/O) PAH derivatives in 45 sediment, 13 street dust, and 68 aerosol samples. Total sediment PAHs concentrations ranged from 294 to 12741 ng/g, categorized as moderate contamination compared to other regions of Asia and the world. In addition, the PAH compounds appeared to be bound more strongly to aromatics-rich soot particles than to natural organic matter, implying a prevailing atmospheric transport route for PAHs to Macao's coast. Compositional analysis and principal component analysis (PCA) suggested that different classes of PAHs in the coastal sediments of Macao may have been derived from different input sources via various transport pathways. For example, alkylated and S/O PAHs were likely derived from fossil fuel leakage and transported to sediments by both aerosols particles and street runoff. High-molecular-weight parent PAHs were predominantly originated from automobile exhausts and distributed by direct and indirect atmospheric deposition. Low-molecular-weight parent PAHs, on the other hand, may have stemmed from lower temperature combustion and fossil fuel (such as diesel) spillage from ships and boats and were transported to sediments by river runoff or direct discharge as well as by air-water exchange.

  16. 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

  17. Polycyclic aromatic hydrocarbon (PAHs) and hopanes in stranded tar-balls on the coasts of Peninsular Malaysia: applications of biomarkers for identifying sources of oil pollution.

    PubMed

    Zakaria, M P; Okuda, T; Takada, H

    2001-12-01

    Malaysian coasts are subjected to various threats of petroleum pollution including routine and accidental oil spill from tankers, spillage of crude oils from inland and off-shore oil fields, and run-off from land-based human activities. Due to its strategic location, the Straits of Malacca serves as a major shipping lane. This paper expands the utility of biomarker compounds, hopanes, in identifying the source of tar-balls stranded on Malaysian coasts. 20 tar-ball samples collected from the east and west coast were analyzed for hopanes and polycyclic aromatic hydrocarbons (PAHs). Four of the 13 tar-ball samples collected from the west coast of Peninsular Malaysia were identified as the Middle East crude oil (MECO) based on their biomarker signatures, suggesting tanker-derived sources significantly contributing the petroleum pollution in the Straits of Malacca. The tar-balls found on the east coast seem to originate from the offshore oil platforms in the South China Sea. The presence of South East Asian crude oil (SEACO) tar-balls on the west coast carry several plausible explanations. Some of the tar-balls could have been transported via sea currents from the east coast. The tankers carrying SEACO to other countries could have accidentally spilt the oil as well. Furthermore, discharge of tank washings and ballast water from the tankers were suggested based on the abundance in higher molecular weight n-alkanes and the absence of unresolved complex mixture (UCM) in the tar-ball samples. The other possibilities are that the tar-balls may have been originated from the Sumatran oil fields and spillage of domestic oil from oil refineries in Port Dickson and Malacca. The results of PAHs analysis suggest that all the tar-ball samples have undergone various extent of weathering through evaporation, dissolution and photooxidation.

  18. Constraining uncertainties about the sources and magnitude of polycyclic aromatic hydrocarbon (PAH) levels in ambient air: the state of Minnesota as a case study

    NASA Astrophysics Data System (ADS)

    Lobscheid, Agnes B.; McKone, Thomas E.

    2004-10-01

    Emissions data are often lacking or uncertain for many airborne contaminants. 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 (RWC) and motor vehicle (MV) activity, and/or report "total PAH" or particulate organic matter emissions, instead of individual compound emissions. We assess 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 three major sources of PAHs to outdoor air: (1) on-road MVs, including light-duty gasoline vehicles and diesel-powered buses and medium and heavy-duty trucks; (2) RWC; 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 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 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, we increase our confidence about our plausible ranges of emissions and predicted

  19. Nitration of gaseous polycyclic aromatic hydrocarbons in simulated and ambient urban atmospheres: A source of mutagenic nitroarenes

    NASA Astrophysics Data System (ADS)

    Pitts, James N.

    Recent results from field studies in the Los Angeles air basin which focused on the nature and concentrations of mononitroarenes in the gaseous and particulate states in polluted ambient air are reviewed. Relative concentrations in organic extracts of ambient particulate polycyclic organic matter (POM) were found to be, in decreasing order, 2-NO 2-fluoranthene > 1-NO 2-pyrene ≳ 2-NO 2-pyrene; this is in sharp contrast to primary emissions of diesel soot, where 1-NO 2-PY > 3-NO 2-FL > 8-NO 2-FL. Since light and heavy duty diesel motor vehicle emissions are a significant source of sub-μm particles in the Los Angeles area, the relatively high abundance of 2-NO 2-FL suggests that a significant fraction of the 2-NO 2-FL in southern California may be formed via atmospheric reactions. In a wintertime 1986 study of a high-NO x episode ~ 20 km east of the Los Angeles International Airport, high concentrations of 1- and 2-nitronaphthalenes, much of which could have been in the gaseous state, were collected on a polyurethane backup 'plug,' along with lesser amounts of 2-NO 2-FL (and 1- and 2-NO 2-PY) adsorbed on the particles collected by a Hi-vol prefilter. Two gas phase mechanisms are proposed for the formation of adsorbed 2-NO 2-fluoranthene and gaseous 2-NO 2-naphthalene in urban air (a) during daylight, attack on gaseous FL by OH radicals followed by NO 2 addition, loss of H 2O and condensation of 2-NO 2-FL on particle surfaces (b) reaction with N 2O 5 at night under ambient conditions during which the gaseous NO 3 radical and NO 2 are present, in equilibrium with N 2O 5. Chamber experiments with simulated polluted atmospheres support both of these mechanisms for the formation of 2-NO 2-FL and 2-NO 2-naphthalene; only the OH mechanism seems valid for 2-NO 2-PY. Environmental and health implications of these studies are briefly discussed.

  20. Apparatus for hydrocarbon extraction

    SciTech Connect

    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.

  1. 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.

  2. 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.

  3. 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. PMID:24598148

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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. PMID:23553126

  11. 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.

  12. 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

  13. 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

    2015-11-01

    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

  14. 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.

  15. Hydrocarbons from plants and trees

    SciTech Connect

    Calvin, M.

    1982-07-01

    The way energy was used in the US in 1980 was examined. A diagram shows the development of energy from its source to its end use. The following are described: the carbon dioxide problem - the greenhouse effect, sugar cane as an energy source, hydrocarbon-producing plants and trees, and isoprenoids from plants and trees. (MHR)

  16. 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

  17. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary).

    PubMed

    Gireeshkumar, T R; Deepulal, P M; Chandramohanakumar, N

    2015-03-01

    Surface sediments samples from the Cochin estuary were measured for elemental, stable isotopic and molecular biomarkers (aliphatic hydrocarbons and fatty acids) to study the sources and distribution of sedimentary organic matter. Concentrations of total organic carbon (TOC), total nitrogen (TN) and stable isotopic ratios of carbon (δ(13)C) ranged from 0.62 to 2.74 %, 0.09 to 0.25 % and -27.5 to 21.7 ‰, respectively. Sedimentary n-alkanes ranged from 6.03 to 43.23 μg g(-1) with an average of 16.79 μg g(-1), while total fatty acids varied from 22.55 to 440.69 μg g(-1). The TOC/TN ratios and δ(13)C suggest a mixture of marine- and terrestrial-derived organic matter in the surface sediments with increasing contributions from marine-derived organic matter towards the seaward side. Long-chain n-alkanes derived from higher plants predominated the inner part of the estuary, while short-chain n-alkanes derived from planktonic sources predominated the bar mouth region. The even carbon preference of the C12-C22 n-alkanes may refer to the direct biogenic contribution from bacteria, fungi and yeast species and to the potential direct petroleum inputs. The presence of odd mid-chain n-alkanes in the sediments indicates the organic matter inputs from submerged and floating macrophytes (water hyacinth). Various molecular indices such as carbon preference index, terrestrial to aquatic ratio, average chain length and the ratios of mid-chain n-alkanes support the aforementioned inferences. The high contribution of odd and branched chain fatty acids along with very low contribution of polyunsaturated fatty acids, suggest the effective utilisation of algae-derived organic matter by bacteria and the effective recycling of labile organic matter in whole settling and deposition processes. The distributional variability of n-alkanes and fatty acids reveals the preferential utilisation of marine-derived organic matter and the selective preservation of terrestrial

  18. Concentration and source identification of polycyclic aromatic hydrocarbons (PAHs) in PM10 of urban, industrial and semi-urban areas in Malaysia

    NASA Astrophysics Data System (ADS)

    Jamhari, Anas Ahmad; Sahani, Mazrura; Latif, Mohd Talib; Chan, Kok Meng; Tan, Hock Seng; Khan, Md Firoz; Mohd Tahir, Norhayati

    2014-04-01

    Particulate matter (PM10) associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined at two sites within the Klang Valley, Kuala Lumpur (urban, KL) and Petaling Jaya (industrial, PJ), and one site outside the Klang Valley, Bangi (semi-urban, BG). This study aimed to determine the concentration and distribution of PAHs in PM10 and the source of origin through principal component analysis (PCA) and diagnostic ratio analysis. This study also assessed the health risk from exposure to airborne BaPeq. PM10 samples were collected on glass fiber filter paper using a High Volume Sampler (HVS) for 24 h between September 2010 and April 2011. The filter papers with PM10 were extracted using dichloromethane-methanol (3:1), and analysis of 16 USEPA priority PAHs was determined using gas chromatography with mass spectra (GC-MS). Health risk assessment was estimated using toxic equivalency factors (TEFs) and incremental lifetime cancer risk (ILCR) which quantitatively estimate the exposure risk for age specific group. The results showed that the total PAHs concentrations throughout seasonal monsoons for KL, PJ and BG ranged from 1.33 ng m-3 to 2.97 ng m-3, 2.24 ng m-3 to 4.84 ng m-3 and 1.64 ng m-3 to 3.45 ng m-3 respectively. More than 80% of total PAHs consisted of 5-ring and 6-ring PAHs such as benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (IcP), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF) and benzo[g,h,i]perylene (BgP). The presence of benzo[g,h,i]perylene (BgP) with high concentration at all locations suggested a source indicator for traffic emission. PCA and diagnostic ratio analysis also suggested substantial contributions from traffic emission with minimal influence from coal combustion and natural gas emissions. The use of total BaPeq concentration provide a better estimation of carcinogenicity activities, where they contributed to more than 50% of the potential health risk. Health risk assessment showed that the estimated incremental

  19. 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.

  20. 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....

  1. 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...

  2. 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

  3. 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.

  4. Tolerance of Antarctic soil fungi to hydrocarbons.

    PubMed

    Hughes, Kevin A; Bridge, Paul; Clark, Melody S

    2007-01-01

    Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation.

  5. Size distribution and sources of 37 toxic species of particulate polycyclic aromatic hydrocarbons during summer and winter in Baoshan suburban area of Shanghai, China.

    PubMed

    Wang, Qingyue; Kobayashi, Keisuke; Wang, Weiqian; Ruan, Jie; Nakajima, Daisuke; Yagishita, Mayuko; Lu, Senlin; Zhang, Wenchao; Suzuki, Miho; Saitou, Tomoya; Sekiguchi, Kazuhiko; Sankoda, Kenshi; Takao, Yuji; Nagae, Masaki; Terasaki, Masanori

    2016-10-01

    The objectives of this study were to assess the size-segregated distribution and sources of 37 different species of particulate polycyclic aromatic hydrocarbons (PAHs) in a suburban area of Shanghai metropolitan City, China. The ambient particulate sampling was carried out on the rooftop of a five-stories building in Baoshan campus of Shanghai University. An Andersen high-volume air sampler was employed to collect ambient size-segregated particulate matter during summer of August to September and winter of November to December 2015. The high toxic PAHs were determined by a gas chromatography mass spectrometry. The concentrations of total PAHs in suspended particulate matter (SPM) and PM1.1 (suspended particulate matter below 1.1μm in diameter) in the suburban area of Shanghai were 4.58-14.5ng/m(3) and 1.82-8.56ng/m(3), respectively in summer, and 43.6-160ng/m(3) and 23.2-121ng/m(3), separately in winter. 1,8-Naphthalic anhydride (1,8-NA) showed the highest concentration among 37 different species of PAHs in the suburban area of Shanghai. The concentrations of high molecular PAHs (e.g. 5-6 ring PAHs) followed a nearly unimodal size distribution with the highest peaks in PM1.1. The diagnostic ration qualitatively indicated that PAHs in SPM of Shanghai were mainly derived from motor-vehicle or petroleum combustion in summer and from coal and biomass combustion in winter. According to the calculated toxicity equivalency factors based on the methods of Nisbet and Lagoy and the potency equivalency factors (PEF) recommended by U.S. EPA, the highest contributors in the total carcinogenicity of the PAHs in SPM and PM1.1 were dibenzo[a,h]pyrene (46.2% and 45.0% in summer), benzo[a]pyrene (44.4% and 43.8% in winter) and benz[j]aceanthrylene (80.2% and 83.1% in summer and 83.1% and 84.0% in winter), respectively. Therefore, benzo[a]pyrene seemed to be a lower contributor than other carcinogenic PAHs.

  6. Geochemical features and sources of hydrocarbons and fatty acids in soils from the McMurdo Dry Valleys in the Antarctic

    NASA Astrophysics Data System (ADS)

    Matsumoto, Genki I.; Honda, Eisuke; Sonoda, Kazuhiko; Yamamoto, Shuichi; Takemura, Tetsuo

    2010-08-01

    We studied the geochemical features and compound-specific (CS)-δ 13C of hydrocarbons and fatty acids in soil samples from the McMurdo Dry Valleys in the Antarctic to elucidate their source organisms and characteristics of their environments. Total organic carbon contents in soil samples were extremely low reflecting extremely harsh environments for organisms. Normal-alkanes ranging in carbon chain length from n-C 14 to n-C 38 with the predominance of odd-carbon numbers were found, together with n-alkenes ( n-C 23:1 to n-C 27:1). Normal-alkanoic acids ranging in carbon chain length from n-C 10 to n-C 30 with the predominance of even-carbon numbers were detected in the samples, along with small amounts of branched ( iso and anteiso) and n-alkenoic acids. CS-δ 13C values of long-chain n-alkanes ( n-C 20 to n-C 29) ranged from -30.4 to -26.6‰. CS-δ 13C values of n-alkanoic acids with short-chain carbon numbers ( n-C 14 to n-C 19) ranging from -27.7 to -21.7‰ were much higher than those of long-chain carbon numbers ( n-C 20 to n-C 30, -32.5 to -25.3‰). The geochemical features and CS-δ 13C values of long-chain n-alkanes and n-alkanoic acids revealed that they are originated from lichen and/or vascular plant debris from the pre- and inter-glacial periods in this region, whereas short-chain n-alkanoic acids are come from microalgae and cyanobacterial debris. CS-δ 13C values suggest that they are derived from gymnosperms and/or C 4 plants in the cold and dry environments of the pre- and inter-glacial periods of the McMurdo Dry Valleys region.

  7. Size distribution and sources of 37 toxic species of particulate polycyclic aromatic hydrocarbons during summer and winter in Baoshan suburban area of Shanghai, China.

    PubMed

    Wang, Qingyue; Kobayashi, Keisuke; Wang, Weiqian; Ruan, Jie; Nakajima, Daisuke; Yagishita, Mayuko; Lu, Senlin; Zhang, Wenchao; Suzuki, Miho; Saitou, Tomoya; Sekiguchi, Kazuhiko; Sankoda, Kenshi; Takao, Yuji; Nagae, Masaki; Terasaki, Masanori

    2016-10-01

    The objectives of this study were to assess the size-segregated distribution and sources of 37 different species of particulate polycyclic aromatic hydrocarbons (PAHs) in a suburban area of Shanghai metropolitan City, China. The ambient particulate sampling was carried out on the rooftop of a five-stories building in Baoshan campus of Shanghai University. An Andersen high-volume air sampler was employed to collect ambient size-segregated particulate matter during summer of August to September and winter of November to December 2015. The high toxic PAHs were determined by a gas chromatography mass spectrometry. The concentrations of total PAHs in suspended particulate matter (SPM) and PM1.1 (suspended particulate matter below 1.1μm in diameter) in the suburban area of Shanghai were 4.58-14.5ng/m(3) and 1.82-8.56ng/m(3), respectively in summer, and 43.6-160ng/m(3) and 23.2-121ng/m(3), separately in winter. 1,8-Naphthalic anhydride (1,8-NA) showed the highest concentration among 37 different species of PAHs in the suburban area of Shanghai. The concentrations of high molecular PAHs (e.g. 5-6 ring PAHs) followed a nearly unimodal size distribution with the highest peaks in PM1.1. The diagnostic ration qualitatively indicated that PAHs in SPM of Shanghai were mainly derived from motor-vehicle or petroleum combustion in summer and from coal and biomass combustion in winter. According to the calculated toxicity equivalency factors based on the methods of Nisbet and Lagoy and the potency equivalency factors (PEF) recommended by U.S. EPA, the highest contributors in the total carcinogenicity of the PAHs in SPM and PM1.1 were dibenzo[a,h]pyrene (46.2% and 45.0% in summer), benzo[a]pyrene (44.4% and 43.8% in winter) and benz[j]aceanthrylene (80.2% and 83.1% in summer and 83.1% and 84.0% in winter), respectively. Therefore, benzo[a]pyrene seemed to be a lower contributor than other carcinogenic PAHs. PMID:27320739

  8. 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˚? - discharge of

  9. 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...

  10. Multi-scale monitoring of a marine geologic methane source in the Santa Barbara Channel using imaging spectrometry, ARCTAS-CARB in situ sampling and coastal hourly total hydrocarbon measurements

    NASA Astrophysics Data System (ADS)

    Bradley, E. S.; Leifer, I.; Roberts, D.; Dennison, P. E.; Margolis, J.; Moritsch, M.; Diskin, G. S.; Sachse, G. W.

    2009-12-01

    The Coal Oil Point (COP) hydrocarbon seep field off the coast of Santa Barbara, CA is one of the most active and best-studied marine geologic methane sources in the world and contributes to elevated terrestrial methane concentrations downwind. In this study, we investigate the spatiotemporal variability of this local source and the influence of meteorological conditions on transport and concentration. A methane plume emanating from Trilogy Seep was mapped with the Airborne Visible Infrared Imaging Spectrometer at a 7.5 m resolution with a short-wave infrared band ratio technique. This structure agrees with the local wind speed and direction and is orthogonal to the surface currents. ARCTAS-CARB aircraft in situ sampling of lower-troposphere methane is compared to sub-hour total hydrocarbon concentration (THC) measurements from the Santa Barbara Air Pollution Control District (SBAPCD) station located near COP. Hourly SBAPCD THC values from 1980-2008 demonstrate a decrease in seep source strength until the late 1990s, followed by a consistent increase. The occurrence of elevated SBAPCD THC values for onshore wind conditions as well as numerous positive outliers as high as 17 ppm suggests that seep field emissions are both quasi-steady state and transient, direct (bubble) and diffuse (outgassing). As demonstrated for the COP seeps, the combination of imaging spectrometry, aircraft in situ sampling, and ground-based monitoring provides a powerful approach for understanding local methane sources and transport processes.

  11. Atmospheric hydrocarbon chemistry in central Texas

    NASA Astrophysics Data System (ADS)

    Wittig, Ann Elizabeth

    Hydrocarbon chemistry plays a central role in the determination of the concentrations of ozone, nitrogen oxides and particulate matter in the ambient troposphere. Many years of research have led to a preliminary understanding of the complex chemistry of the thousands of hydrocarbons that are emitted into the atmosphere by biogenic and anthropogenic sources. However, much remains unresolved. This thesis will address several of the unresolved issues in the complex hydrocarbon chemistry that occurs in urban atmospheres. The first portion of this thesis reports atmospheric concentrations of hydrocarbons in Central Texas. These concentrations were compared to hydrocarbon concentrations observed in other urban areas. Probable sources of atmospheric hydrocarbons within Central Texas were identified from spatially resolved hydrocarbon emission inventories. These measurements and identified probable sources suggest the second major portion of the thesis: an analysis of one of the most commonly used source resolution tools, the Chemical Mass Balance (CMB) method. CMB uses linear algebra to identify the sources and source strengths of hydrocarbons in ambient air samples. However, there are several assumptions made by the model to accomplish this task, and these assumptions are believed to impair the model's accuracy. Therefore, the second portion of the thesis characterized the uncertainties associated with the accuracy of CMB, particularly when it was applied to ambient data from Southeast Texas. A multistage box model was constructed to simulate ambient hydrocarbon concentrations in Houston. The box model simulated the inputs of hydrocarbon sources into a hypothetical air mass, while accounting for the unique reactivities of each of the modeled hydrocarbons. The CMB tool was then applied to the data generated by the box model and used to estimate source strengths. The source strengths estimated by CMB were compared to the original inputs to the model. The results indicated

  12. 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.

  13. 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

  14. Allocation of Resources. SPEC Kit 31.

    ERIC Educational Resources Information Center

    Association of Research Libraries, Washington, DC. Office of Management Studies.

    This kit on resource allocation in academic and research libraries contains nine primary source documents and a concise summary of a 1976 Association of Research Libraries (ARL) survey on management of fiscal spending activities in ARL libraries. Based on responses from 70 libraries, the summary discusses 3 specific subjects within the general…

  15. 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...

  16. The Allocation of Materials Funds. SPEC Kit 36.

    ERIC Educational Resources Information Center

    Association of Research Libraries, Washington, DC. Office of Management Studies.

    This Association of Research Libraries (ARL) kit contains source documents providing information on the general background, statistics/criteria, formulas, and decision-making processes used in the allocation of materials funds in academic libraries. The kit comprises: (1) a working paper on "Guidelines for the Allocation of Library Materials…

  17. 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…

  18. 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.

  19. A new receptor model-incremental lifetime cancer risk method to quantify the carcinogenic risks associated with sources of particle-bound polycyclic aromatic hydrocarbons from Chengdu in China.

    PubMed

    Liu, Gui-Rong; Peng, Xing; Wang, Rong-Kang; Tian, Ying-Ze; Shi, Guo-Liang; Wu, Jian-Hui; Zhang, Pu; Zhou, Lai-Dong; Feng, Yin-Chang

    2015-01-01

    PM10 and PM2.5 samples were simultaneously collected during a one-year monitoring period in Chengdu. The concentrations of 16 particle-bound polycyclic aromatic hydrocarbons (Σ16PAHs) were measured. Σ16PAHs concentrations varied from 16.85 to 160.24 ng m(-3) and 14.93 to 111.04ngm(-3) for PM10 and PM2.5, respectively. Three receptor models (principal component analysis (PCA), positive matrix factorization (PMF), and Multilinear Engine 2 (ME2)) were applied to investigate the sources and contributions of PAHs. The results obtained from the three receptor models were compared. Diesel emissions, gasoline emissions, and coal and wood combustion were the primary sources. Source apportionment results indicated that these models were able to track the ΣPAHs. For the first time, the cancer risks for each identified source were quantitatively calculated for ingestion and dermal contact routes by combining the incremental lifetime cancer risk (ILCR) values with the estimated source contributions. The results showed that gasoline emissions posed the highest cancer risk, even though it contributed less to Σ16PAHs. The results and method from this work can provide useful information for quantifying the toxicity of source categories and studying human health in the future. PMID:25464284

  20. Hydrocarbon components in carbonaceous meteorites

    NASA Astrophysics Data System (ADS)

    Kissin, Y. V.

    2003-05-01

    Currently, the presence of free n-alkanes and isoprenoid alkanes in carbonaceous meteorites is usually explained either by microbial contamination during the period between the meteorite fall and collection or by contamination from the environment of analytical laboratories and museums. The goal of this research was to repeat analysis of hydrocarbon components in meteorites and to investigate possible meteorite contamination routes discussed in the literature. Experimental analysis of free organic constituents in five carbonaceous meteorites by infrared spectroscopy (IR) and gas chromatographic (GC) methods confirmed the presence of extractable aliphatic components, n-alkanes in the C 15H 32-C 27H 56 range and isoprenoid alkanes (phytane, pristane, and norpristane), in some of these meteorites. The contents of these compounds vary depending on the source. Insoluble organic components of two meteorites (meteorite kerogens) were isolated, and their composition was analyzed by IR and cracking/GC methods. Comparison with the data on several terrestrial contamination sources proposed in the literature shows that the presence of free saturated hydrocarbons in meteorites and the composition of the meteorite kerogen could not be explained either by microbial contamination or by contamination from the laboratory environment. The types of the hydrocarbons in meteorites resemble those typical of ancient terrestrial deposits of organic-rich sediments, except for the absence of lighter hydrocarbons, which apparently slowly evaporated in space, and multi-ring naphthenic compounds of the biologic origin, steranes, terpanes, etc. The prevailing current explanation for the presence of free linear saturated hydrocarbons in carbonaceous meteorites, apart from contamination, is the abiotic route from hydrogen and carbon monoxide. However, the data on the structure of meteorite kerogens require a search for different routes that initially produce complex polymeric structures containing

  1. Foraminiferal biostratigraphy, depositional environments and hydrocarbon source rock potential of sediments from five wells in the western offshore region of the Niger delta, Nigeria

    SciTech Connect

    Adekoya, A.A.

    1987-01-01

    The Tertiary lithostratigraphy of the Niger delta consists of three units: The Akata, Agbada and Benin Formations. The Akata formation is characterized by a uniform development of grey, silty, undercompacted marine shales, containing lenses of abnormally high pressured fine grained sandstones. These pro-delta shales were deposited predominantly under anoxic conditions, on the continental slope. The Akata Formation is of Paleocene to Early Miocene age. The Agbada Formation is of Miocene-Pliocene age, and consists of a paralic sequence of alternating sandstones and shales. These were deposited on the delta front, distributary channels and lower delta plain environments. The Benin Formation consists predominantly of massive, porous, freshwater-bearing sands, with local thin shale interbeds. This formation was deposited in alluvial environments, including the braided stream and meander belt systems of the upper delta plain. Foraminiferal biostratigraphic analyses were made of sediments from the Akata and Agbada Formations in the Okan-74, Mesan-B, Meji-29, ET-1, and EA-5 wells. Index planktonic foraminifera enabled the zonation of the individual stratigraphic sequences. Five benthonic foraminiferal zones and ten biofacies/biofacies complexes are defined and correlated across the study area. Rock evaluation pyrolysis results indicate that the sediments contain adequate organic matter for hydrocarbon generation, while the Tmax data confirm burial to depths corresponding to the oil generation window. The vitrinite reflectance data confirm that some of the sediments are mature, and hydrocarbons (predominantly gas) generation has taken place from the predominant type III kerogens present in the organic matter.

  2. 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.

  3. Synaptic Tagging During Memory Allocation

    PubMed Central

    Rogerson, Thomas; Cai, Denise; Frank, Adam; Sano, Yoshitake; Shobe, Justin; Aranda, Manuel L.; Silva, Alcino J.

    2014-01-01

    There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled. PMID:24496410

  4. 50 CFR 660.323 - Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment. 660.323 Section 660.323 Wildlife and Fisheries FISHERY...) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.323 Pacific whiting...

  5. 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.

  6. Hydrocarbon product stripping

    SciTech Connect

    Harandi, M.N.; Owen, H.; Siuta, M.T.

    1989-04-18

    A method is described for stripping light gasiform components from the liquid effluent of a catalytic hydrodesulfurization process, which comprises separating the liquid effluent containing relatively low boiling hydrocarbon components, relatively high boiling hydrocarbon components, hydrogen, and hydrogen sulfide.

  7. 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.

  8. Hydrocarbon distribution in the Maracaibo Basin

    SciTech Connect

    Scherer, W.

    1996-08-01

    The prolific Maracaibo basin contains the second largest hydrocarbon accumulation in South America; it has been one of the principal oil producers of the world since the beginning of this century. Exploratory efforts in this basin, carried out with new techniques and new ideas, continue today, so it is of interest to determine the trends of hydrocarbon concentrations in terms of resources per unit volume of sediments and to correlate them to stratigraphic, sedimentary-tectonic and geochemical variables. Regional scale maps representing the 24 principal geologic and geochemical variables that are thought to be a function of hydrocarbon generation, migration and accumulation were discretized on a 25 x 25 km grid. Variables used are isopach and Total Organic Carbon (TOC) of source rocks, isopach, sandstone content and grain size parameters of reservoir rocks, isopach of stratigraphic seal and overburden, maximum paleotemperatures (R{sub o} and T{sub max}), tectonic energy (fault length and displacement) and hydrocarbon families. Multivariate analytical statistics was used to obtain the trends of hydrocarbon distributions. The resulting hydrocarbon concentration trend map was quantitatively correlated to known hydrocarbon accumulations and prospective areas, where additional new accumulations might be found, were obtained. It can be shown that the largest known hydrocarbon concentrations correspond to areas of greatest cumulative overburden. The southern Zulia Catatumbo region is the largest prospective area determined by this method.

  9. [Organ allocation. Ethical issues].

    PubMed

    Cattorini, P

    2010-01-01

    The criteria for allocating organs are one of the most debated ethical issue in the transplantation programs. The article examines some rules and principles followed by "Nord Italia Transplant program", summarized in its Principles' Charter and explained in a recent interdisciplinary book. General theories of justice and their application to individual clinical cases are commented and evaluated, in order to foster a public, democratic, transparent debate among professionals and citizens, scientific associations and customers' organizations. Some specific moral dilemmas are focused regarding the concepts of proportionate treatment, unselfish donation by living persons, promotion of local institutions efficiency. PMID:20677677

  10. 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.

  11. 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.

  12. 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

  13. Vertical distribution and source identification of polycyclic aromatic hydrocarbons (PAHs) in southwest of the Caspian Sea: most petrogenic events during the late Little Ice Age.

    PubMed

    Varnosfaderany, Mohammad Nemati; Bakhtiari, Alireza Riyahi; Gu, Zhaoyan; Chu, Guoqiang

    2014-10-15

    In this study, 75 samples of two (210)Pb-dated cores from the southwest of the Caspian Sea were analysed for 30 compounds of polycyclic aromatic hydrocarbons (PAHs). The TPAH29 flux of the last six centuries ranged from 16.3 to 177.3 and 22.3 to 426.2 ng cm(-2)y(-1) in the Rezvanshahr and Anzali core sediments, respectively. Prior to 1840, four distinct maxima in PAH fluxes (61-426.2 ng cm(-2)y(-1)) with a low weathered petrogenic pattern were found in each of the core sediments. Simultaneity of distinct peaks of PAH fluxes before 1840 and Caspian Sea level high-stands during the Little Ice Age (LIA), revealed the high importance of this phenomenon in washing and transport of land-based oil pollution into the Caspian Sea. An overall increase in some diagnostic ratios (Flu/202, IP/276 and BaA/228), especially after 1940, indicated increase of pyrogenic PAHs as a result of industrial development in the catchment area.

  14. 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.

  15. 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.

  16. 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. PMID:23683048

  17. Generalized multidimensional dynamic allocation method.

    PubMed

    Lebowitsch, Jonathan; Ge, Yan; Young, Benjamin; Hu, Feifang

    2012-12-10

    Dynamic allocation has received considerable attention since it was first proposed in the 1970s as an alternative means of allocating treatments in clinical trials which helps to secure the balance of prognostic factors across treatment groups. The purpose of this paper is to present a generalized multidimensional dynamic allocation method that simultaneously balances treatment assignments at three key levels: within the overall study, within each level of each prognostic factor, and within each stratum, that is, combination of levels of different factors Further it offers capabilities for unbalanced and adaptive designs for trials. The treatment balancing performance of the proposed method is investigated through simulations which compare multidimensional dynamic allocation with traditional stratified block randomization and the Pocock-Simon method. On the basis of these results, we conclude that this generalized multidimensional dynamic allocation method is an improvement over conventional dynamic allocation methods and is flexible enough to be applied for most trial settings including Phases I, II and III trials.

  18. Ether and hydrocarbon production

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1991-03-19

    This patent describes a continuous process for converting lower aliphatic alkanol and olefinic hydrocarbon to alkyl tertiary-alkyl ethers and C{sub 5} + gasoline boiling range hydrocarbons. It comprises contacting alkanol and a light olefinic hydrocarbon stream rich in isobutylene and other C{sub 4} isomeric hydrocarbons under iso-olefin etherification conditions in an etherification reaction zone containing acid etherification catalyst; separating etherification effluent to recover a light stream comprising unreacted alkanol and light olefinic hydrocarbon and a liquid product stream containing alkyl tertiary-butyl ether; and contacting the light stream with acidic, medium pore metallosilicate catalyst under alkanol and hydrocarbon conversion conditions whereby C{sub 5} + gasoline boiling range hydrocarbons are produced.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Effects of meteorology on diurnal and nocturnal levels of priority polycyclic aromatic hydrocarbons and elemental and organic carbon in PM 10 at a source and a receptor area in Mexico City

    NASA Astrophysics Data System (ADS)

    Guzmán-Torres, Diana; Eiguren-Fernández, Arantza; Cicero-Fernández, Pablo; Maubert-Franco, Marisela; Retama-Hernández, Armando; Ramos Villegas, Rafael; Miguel, Antonio H.

    PM 10 levels of the 16 US-EPA Priority Pollutant polycyclic aromatic hydrocarbons (PAHs) were measured from March 17 to 31, 2003, in 8-h time bins (morning, afternoon and nighttime) at Merced, a source site dominated by vehicular traffic emissions near the center of Mexico City, and at Pedregal, a receptor area located downwind in a residential area of low traffic. Along with PAH, elemental (EC) and organic carbon (OC), mass, and prevailing meteorological parameters were measured. At the source location, measured concentrations of benzo[ a]pyrene (BAP), an agent suspected of being carcinogenic to humans and of causing oxidative DNA damage, reached concentrations as high as 2.04 and 2.11 ng m -3 during the morning of a weekday and the night period of a holiday. Compared with source dominated areas in Central Los Angeles, the BAP levels found in Central Mexico City are approximately 6 times higher. Benzo[ ghi]perylene (BGP) levels were, in general, the highest among the target PAH, both at the source (7.2 ng m -3) and the receptor site (2.8 ng m -3), suggesting that, at both locations, exhaust emission by light-duty (LD) vehicles is an important contributor to the atmospheric PAH burden. Higher PAH concentrations were observed during the morning period (5:00-13:00 h) at the source and the receptor site. The concentrations of PAHs found predominantly in the particle-phase (MW > 202) correlated well ( r = 0.57-0.71) with the occurrence of surface thermal inversions and with mixing heights ( r = -0.57 to -0.72). Organic and elemental carbon ratios also indicated that Pedregal is impacted by secondary aerosols during the afternoon hours.

  4. 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.

  5. The Principal as Resource Allocator.

    ERIC Educational Resources Information Center

    Peterson, Kent D.

    The effect of political influences on the allocation of personnel, money, facilities, and equipment by elementary school principals is discussed in this paper. The use of Zald's political economy framework as a tool for understanding the principal's role in allocating resources is described by the author. He suggests that the principal occupies a…

  6. 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.

  7. 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.

  8. 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.

  9. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Formula allocation. 92.50 Section... Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation. (a) Jurisdictions eligible for a formula allocation. HUD will provide allocations of funds in amounts determined...

  10. 23 CFR 1240.15 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 1240.15 Section 1240.15 Highways NATIONAL... GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.15 Allocations. (a) Funds allocated under this part shall be available...

  11. Dynamic advance reservation with delayed allocation

    DOEpatents

    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.

  12. 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.

  13. 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.

  14. Aliphatic Hydrocarbons of Cladosporium resinae Cultured on Glucose, Glutamic Acid, and Hydrocarbons

    PubMed Central

    Walker, J. D.; Cooney, J. J.

    1973-01-01

    The carbon source markedly influenced the qualitative and quantitative composition of cellular hydrocarbons in Cladosporium resinae. Total lipid and hydrocarbon content was greater in cells grown on n-alkanes than in cells grown on glucose or glutamic acid. Glucose-grown cells contained a spectrum of aliphatic hydrocarbons from C7 to C36; pristane and n-hexadecane comprised 98% of the total. Cells grown on glutamic acid contained C7 to C23 hydrocarbons; n-tridecane, n-tetradecane, n-hexadecane, and pristane made up 74% of the total. n-Decane-grown cells yielded C8 to C32 compounds, and n-hexadecane (96%) was the major hydrocarbon. Cells grown on individual n-alkanes from C11 to C15 all contained C11 to C28 hydrocarbons, and cells grown on n-hexadecane contained C11 to C32 hydrocarbons. In n-undecane-grown cells, n-hexadecane and pristane made up 92% of the total, but in cells grown on C12 to C16 n-alkanes the major cellular hydrocarbon was the one on which the cells were grown. This suggests that cells cultured on n-alkanes of C12 or longer accumulate n-alkanes prior to oxidizing them. PMID:4762391

  15. Apparatus for heat induced separation of hydrocarbon constituents from coal

    SciTech Connect

    Pine, M.; Johnson, J.R.; Moss, R.E.; Sandoval, R.A.

    1984-09-25

    A method and apparatus is provided for accomplishing thermal separation of various hydrocarbons and other compounds from coal, a hydrocarbon rendering module is provided for the continuous agitation and circulation of coal during the rendering period and utilizes thermal trays having stationary and revolving apparatus to improve heat transfer to coal particles and minimize rendering time. Portions of the rendered hydrocarbon products are recycled to the mechanism as an energy source for continuous operation.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  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. Identification and quantification of mixed sources of oil spills based on distributions and isotope profiles of long-chain n-alkanes.

    PubMed

    Li, Yun; Xiong, Yongqiang

    2009-12-01

    Combined with quantitative determination of concentration and isotopic composition of petroleum hydrocarbons, weathering simulation experiments on artificially mixed oils and their two end-member oils are performed for identification and quantification of mixed sources. The >C(18)n-alkanes show no appreciable losses during a short-term weathering process. An approach based on distribution of long-chain n-alkanes (>C(18)) is suggested for estimating the contribution proportion of each source in mixed oils. Stable carbon isotope profile of individual n-alkanes is a powerful tool to differentiate sources of oil spills, but unavailable to accurately allocate each contribution due to a relatively large analytical error.