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Sample records for coal tar allergy

  1. Centrifuge treatment of coal tar

    SciTech Connect

    L.A. Kazak; V.Z. Kaidalov; L.F. Syrova; O.S. Miroshnichenko; A.S. Minakov

    2009-07-15

    New technology is required for the removal of water and heavy fractions from regular coal tar. Centrifuges offer the best option. Purification of coal tar by means of centrifuges at OAO NLMK permits the production of pitch coke or electrode pitch that complies with current standards.

  2. Coal tar phototherapy for psoriasis reevaluated: erythemogenic versus suberythemogenic ultraviolet with a tar extract in oil and crude coal tar

    SciTech Connect

    Lowe, N.J.; Wortzman, M.S.; Breeding, J.; Koudsi, H.; Taylor, L.

    1983-06-01

    Recent studies have questioned the therapeutic value of coal tar versus ultraviolet (UV) radiation and their relative necessity in phototherapy for psoriasis. In this investigation, different aspects of tar phototherapy have been studied in single-blind bilateral paired comparison studies. The effects of 1% crude coal tar were compared with those of petrolatum in conjunction with erythemogenic and suberythemogenic doses of ultraviolet light (UVB) using a FS72 sunlamp tubed cabinet. Crude coal tar was clinically superior to petrolatum with suberythemogenic ultraviolet. With the erythemogenic UVB, petrolatum was equal in efficacy to crude coal tar. Suberythemogenic UVB was also used adjunctively to compare the effects of a 5% concentration of a tar extract in an oil base to 5% crude coal tar in petrolatum or the oil base without tar. The tar extract in oil plus suberythemogenic UVB produced significantly more rapid improvement than the oil base plus UVB. The direct bilateral comparison of equal concentrations of tar extract in oil base versus crude coal tar in petrolatum in a suberythemogenic UV photo regimen revealed no statistical differences between treatments. In a study comparing tar extract in oil and the oil base without ultraviolet radiation, the tar extract in oil side responded more rapidly.

  3. Higher temperature coal tar enamel fights corrosion

    SciTech Connect

    Johnson, J.R.; Henegar, S.; Roder, B.

    1996-10-01

    High temperatures create new challenges for pipeline coatings. Cracking, adhesion breakdown and electrochemical corrosion are accelerated by higher service temperatures. A new epoxy primer/coal tar pipeline coating system utilizes the latent heat of the coal tar application to fully cure the newly developed primer to achieve outstanding bonding integrity and high temperature cathodic disbondment resistance. A key reason for this overall high performance is the marriage of a newly developed epoxy primer that provides outstanding adhesion with coal tar enamel, which provides excellent long-term water resistance. The paper describes experimental studies, pilot plant application, cathodic disbondment testing, and results from hot water soak tests and the low temperature cracking test.

  4. 40 CFR 721.10532 - Tar, brown coal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tar, brown coal. 721.10532 Section 721... Tar, brown coal. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as tar, brown coal (PMN P-12-167, CAS No. 101316-83-0) is subject...

  5. 40 CFR 721.10532 - Tar, brown coal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tar, brown coal. 721.10532 Section 721... Tar, brown coal. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as tar, brown coal (PMN P-12-167, CAS No. 101316-83-0) is subject...

  6. Investigation of coal tar mobility at a former MGP site

    SciTech Connect

    Moo-Young, H.K.; Mo, X.H.; Waterman, R.; Coleman, A.; Saroff, S.

    2009-11-15

    The presence of coal tar in the subsurface of former manufactured gas plant sites poses an environmental hazard and a potential threat to public health. Coal tar can release various chemical compounds that are transported into the groundwater. Before any efforts can be made to remove coal tar from contaminated subsurface soils, it is recommended to characterize coal tar properties and composition and to delineate the residual saturation point between mobile and immobile coal tar. This paper presents a new innovative field device, the Res-SAT field tool, and laboratory procedures that can be used to determine the saturation-capillary pressure relationship for a soil-water coal-tar system and the critical pressure for coal tar mobility.

  7. Final safety assessment of Coal Tar as used in cosmetics.

    PubMed

    2008-01-01

    Coal Tar is a semisolid by-product obtained in the destructive distillation of bituminous coal, which functions in cosmetic products as a cosmetic biocide and denaturant--antidandruff agent is also listed as a function, but this is considered an over-the-counter (OTC) drug use. Coal Tar is a nearly black, viscous liquid, heavier than water, with a naphthalene-like odor and a sharp burning taste, produced in cooking ovens as a by-product in the manufacture of coke. Crude Coal Tar is composed of 48% hydrocarbons, 42% carbon, and 10% water. In 2002, Coal Tar was reported to the Food and Drug Administration (FDA) to be used in four formulations, all of which appear to be OTC drug products. Coal Tar is monographed by the FDA as Category I (safe and effective) OTC drug ingredient for use in the treatment of dandruff, seborrhoea, and psoriasis. Coal Tar is absorbed through the skin of animals and humans and is systemically distributed. In short-term studies, mice fed a diet containing Coal Tar found it unpalatable, but no adverse effects were reported other than weight loss; rats injected with Coal Tar experienced malaise in one study and decreased water intake and increased liver weights in another; rabbits injected with Coal Tar residue experienced eating avoidance, respiratory difficulty, sneezing, and weight loss. In a subchronic neurotoxicity study using mice, a mixture of phenols, cresols, and xylenols at concentrations approximately equal to those expected in Coal Tar extracts produced regionally selective effects, with a rank order of corpus striatum > cerebellum > cerebral cortex. Coal Tar applied to the backs of guinea pigs increases epidermal thickness. Painting female rabbits with tar decreases the absolute and relative weights of the ovaries and decreased the number of interstitial cells in the ovary. Four therapeutic Coal Tar preparations used in the treatment of psoriasis were mutagenic in the Ames assay. Urine and blood from patients treated with Coal Tar

  8. Manufacture of road paving asphalt using coal tar

    SciTech Connect

    Yan, T.Y.

    1986-09-01

    Coal tar is a ready source of asphaltenes needed in asphalt production. Coal tar pitch itself, however, is unsuitable for making road-paving asphalt, since the resulting material has low ductility, high temperature sensitivity, and low resistance to wear. For this reason, in England, where replacing imported petroleum with local products was important 10 to 20 years ago, it was required that no more than 10 to 20 percent coal tar pitch be incorporated in road pavement. At higher concentrations, the pitch separates from the petroleum-derived asphalt, causing brittleness and cracking. To make a good asphalt from coal tar pitch, chemical modification or blending with additives appears necessary. In this study, the potentials are for producing road-paving asphalt from coal tar and available inexpensive petroleum fractions are explored. The objective of the study is to develop new uses of coal tar for asphalt production and to free the petroleum residue for upgrading to gasoline and diesel fuels.

  9. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    SciTech Connect

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  10. Centralized treatment of a wide fraction of coal tar

    SciTech Connect

    Markus, G.A.; Gurzhii, N.I.

    1984-01-01

    A plan is proposed for centralizing treatment of coal tar and raw benzene in certain areas of Russia to ensure the increasing effectiveness of recovery of valuable materials from the coal tar and raw benzene. The treatment of tar in the Donetsk and Pridneprovsk regions is proposed to be carried out at a plant in Fenol. The plan proposed for the Fenol plant is outlined and discussed briefly. The centralized treatment ensures an increase in the production of naphthalene, phenols, pyridine and quinoline bases, indenecoumarone tars, and benzine hydrocarbons.

  11. Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs.

    PubMed

    Peng, Libin; Wang, Li; Hu, Xingting; Wu, Peihui; Wang, Xueqing; Huang, Chumei; Wang, Xiangyang; Deng, Dayi

    2016-11-15

    The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability.

  12. Simultaneous upgrading of tar sand bitumen and coal by corefining

    SciTech Connect

    Hsich, C.R.; Donaldson, W.I.

    1988-08-16

    A continuous process is described for simultaneously corefining a mixture of comminuted coal and tar sand bitumen to form a liquid refinery feed stock, having improved hydrocarbon content and viscosity and reduced organo-metallic and metal components, which process comprises: (a) combining bitumen substantially separated from tar sands with comminuted raw coal at a coal to liquid weight ratio of from about 1:2 to about 1 to 50 to form a slurry mixture; (b) subjecting the slurry mixture resulting from step (a) to hydrocracking conditions in the absence of added catalyst to produce off-gases and a mixture of co-refined bitumen and coal liquid and coal ash residues; and (c) recovering the corefined improve coal-bitumen liquid as a refinery feedstock.

  13. Biodegradation of naphthalene from coal tar. Research progress report

    SciTech Connect

    Ghoshal, S.; Ramaswami, A.; Luthy, R.G.

    1994-02-07

    Biodegradation experiments were conducted to evaluate the mineralization of naphthalene released from coal tar entrapped in microporous silica media. Tests were performed with two coal tars recovered from former manufactured gas plant sites. Results from these tests showed that the degradation end point for naphthalene was significantly lower than the total amount of naphthalene present in coal tar. The role of physico-chemical and biological processes on the rate of biotransformation of naphthalene was evaluated. Mass transfer rates for dissolution of naphthalene from entrapped coal tar were measured in batch, flow-through systems. The rate of naphthalene mass transfer from the coal tar was found to be significantly greater than the rate of naphthalene biomineralization in batch slurry reactors. This implied that the rate acting factor for the biodegradation process was related to biokinetic phenomena rather than mass transfer processes. Further tests indicated that conditions inhibitory to bacteria limited the biodegradation of naphthalene, and in some cases the inhibition was reversible upon dilution of the reactor contents.

  14. Feasibility of coal tar biodegradation by land treatment. Final report

    SciTech Connect

    Fogel, S.

    1987-09-01

    Coal tar, a by-product of coal gasification, contains monoaromatic and polycyclic aromatic hydrocarbons (PAH) which have been identified as carcinogens. Billions of gallons of this waste have been disposed of at numerous gas manufacturing facilities in the United States. The treatment of tar-contaminated soil by bacterial degradation has shown great promise, since one-, two-, and three-ring PAH can be readily degraded by bacteria. Research was carried out to establish whether 4- and 5-ring PAH could also be degraded by bacteria. The data indicated that 4-ring PAH could degrade when dissolved in a hydrocarbon carrier or when applied to soil as a component of coal tar. Experiments to stimulate the bacterial degradation of benzo(a)pyrene, a 5-ring PAH, were unsuccessful.

  15. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 6 2013-07-01 2013-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  16. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 6 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  17. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 6 2014-07-01 2013-07-01 true Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  18. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  19. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 6 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  20. Raoult's law-based method for determination of coal tar average molecular weight

    SciTech Connect

    Brown, D.G.; Gupta, L.; Horace, H.K.; Coleman, A.J.

    2005-08-01

    A Raoult's law-based method for determining the number average molecular weight of coal tars is presented. The method requires data from two-phase coal tar/water equilibrium experiments, which readily are performed in environmental laboratories. An advantage of this method for environmental samples is that it is not impacted by the small amount of inert debris often present in coal tar samples obtained from contaminated sites. Results are presented for 10 coal tars from nine former manufactured gas plants located in the eastern United States. Vapor pressure osmometry (VPO) analysis provided similar average molecular weights to those determined with the Raoult's law-based method, except for one highly viscous coal tar sample. Use of the VPO-based average molecular weight for this coal tar resulted in underprediction of the coal tar constituents' aqueous concentrations. Additionally, one other coal tar was not completely soluble in solvents used for VPO analysis. The results indicate that the Raoult's law-based method is able to provide an average molecular weight that is consistent with the intended application of the data (e.g., modeling the dissolution of coal tar constituents into surrounding waters), and this method can be applied to coal tars that may be incompatible with other commonly used methods for determining average molecular weight, such as vapor pressure osmometry.

  1. Coal tar-containing asphalt - resource or hazardous waste?

    SciTech Connect

    Andersson-Skold, Y.; Andersson, K.; Lind, B.; Claesson, A.; Larsson, L.; Suer, P.; Jacobson, T.

    2007-09-30

    Coal tar was used in Sweden for the production of asphalt and for the drenching of stabilization gravel until 1973. The tar has high concentrations of polycyclic aromatic hydrocarbons (PAH), some of which may be strongly carcinogenic. Approximately 20 million tonnes of tar-containing asphalt is present in the public roads in Sweden. Used asphalt from rebuilding can be classified as hazardous waste according to the Swedish Waste Act. The cost of treating the material removed as hazardous waste can be very high due to the large amount that has to be treated, and the total environmental benefit is unclear. The transport of used asphalt to landfill or combustion will affect other environmental targets. The present project, based on three case studies of road projects in Sweden, evaluates the consequences of four scenarios for handling the material: reuse, landfill, biological treatment, and incineration. The results show that reuse of the coal tar-containing materials in new road construction is the most favorable alternative in terms of cost, material use, land use, energy consumption, and air emissions.

  2. Low solids content, coal tar based impregnating pitch

    SciTech Connect

    Chu, A.S.; Bart, E.F.; Cook, G.R.; Horbachewski, D.M.

    1987-05-12

    A method is described of obtaining a coal tar based impregnant pitch characterized by having a sulfur content of less than 0.5 weight percent and a quinoline insoluble, QI, content of less than about 0.5 percent and enhanced impregnation property. This method comprises: selecting coal tar oil feedstock having: (1) a distillation residue at 355/sup 0/C > 30 weight percent; and (2) a QI < 0.5 weight percent; heating the feedstock to a temperature of between about 150/sup 0/C and 390/sup 0/C; and oxidizing and stripping the feedstock until: an ASTM D-3104-77 softening point between about 90/sup 0/C and 150/sup 0/C; a coking value of at least 45 weight percent according to ASTM D-2416-73; and a flashpoint of at least 200/sup 0/C according to ASTM D92-72 are obtained.

  3. Characterization of Graphitization in Coal Tar and Petroleum Pitches.

    DTIC Science & Technology

    1985-08-01

    range, impurities (mainly nitrogen, sulfur , and hydrogen) are burned off. Shrinkage of the pitch matrix occurs in the 1300-1800*C range. Temperatures are...softening -..-. S.1 7 point, per cent of benzene insolubles and quinoline insolubles, coking value, ash content, specific gravity, and sulfur content (5...Table II gives the chemical analyses for coal-tar and petroleum pitch listing carbon, hydrogen, oxygen, nitrogen, and sulfur content (6,7). Pitch

  4. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  5. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  6. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  7. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  8. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  9. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  10. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  11. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  12. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  13. PAHs and organic matter partitioning and mass transfer from coal tar particles to water.

    PubMed

    Benhabib, Karim; Simonnot, Marie-Odile; Sardin, Michel

    2006-10-01

    The coal tar found in contaminated soils of former manufactured gas plants and coking plants acts as a long-term source of PAHs. Organic carbon and PAH transfer from coal tar particles to water was investigated with closed-looped laboratory column experiments run at various particle sizes and temperatures. Two models were derived. The first one represented the extraction process at equilibrium and was based on a linear partitioning of TOC and PAHs between coal tar and water. The partition coefficient was derived as well as the mass of extractable organic matter in the particles. The second model dealt with mass transfer. Particle diffusion was the limiting step; organic matter diffusivity in the coal tar was then computed in the different conditions. A good consistency was obtained between experimental and computed results. Hence, the modeling of PAH migration in contaminated soils at the field scale requires taking into account coal tar as the source-term for PAH release.

  14. Beach tar accumulation, transport mechanisms, and sources of variability at Coal Oil Point, California.

    PubMed

    Del Sontro, Tonya S; Leifer, Ira; Luyendyk, Bruce P; Broitman, Bernardo R

    2007-09-01

    A new field method for tar quantification was used at Coal Oil Point (COP), California to study the mechanisms transporting oil/tar from the nearby COP natural marine hydrocarbon seep field. This method segregates tar pieces into six size classes and assigns them an average mass based on laboratory or direct field measurements. Tar accumulation on the 19,927m(2) survey area was well resolved spatially by recording tar mass along twelve transects segmented into 4-m(2) blocks and then integrating over the survey area. A seasonal trend was apparent in total tar in which summer accumulations were an order of magnitude higher than winter accumulations. Based on multiple regression analyses between environmental data and tar accumulation, 34% of tar variability is explained by a combination of onshore advection via wind and low swell height inhibiting slick dispersion.

  15. Coal tar induces AHR-dependent skin barrier repair in atopic dermatitis

    PubMed Central

    van den Bogaard, Ellen H.; Bergboer, Judith G.M.; Vonk-Bergers, Mieke; van Vlijmen-Willems, Ivonne M.J.J.; Hato, Stanleyson V.; van der Valk, Pieter G.M.; Schröder, Jens Michael; Joosten, Irma; Zeeuwen, Patrick L.J.M.; Schalkwijk, Joost

    2013-01-01

    Topical application of coal tar is one of the oldest therapies for atopic dermatitis (AD), a T helper 2 (Th2) lymphocyte–mediated skin disease associated with loss-of-function mutations in the skin barrier gene, filaggrin (FLG). Despite its longstanding clinical use and efficacy, the molecular mechanism of coal tar therapy is unknown. Using organotypic skin models with primary keratinocytes from AD patients and controls, we found that coal tar activated the aryl hydrocarbon receptor (AHR), resulting in induction of epidermal differentiation. AHR knockdown by siRNA completely abrogated this effect. Coal tar restored filaggrin expression in FLG-haploinsufficient keratinocytes to wild-type levels, and counteracted Th2 cytokine–mediated downregulation of skin barrier proteins. In AD patients, coal tar completely restored expression of major skin barrier proteins, including filaggrin. Using organotypic skin models stimulated with Th2 cytokines IL-4 and IL-13, we found coal tar to diminish spongiosis, apoptosis, and CCL26 expression, all AD hallmarks. Coal tar interfered with Th2 cytokine signaling via dephosphorylation of STAT6, most likely due to AHR-regulated activation of the NRF2 antioxidative stress pathway. The therapeutic effect of AHR activation herein described opens a new avenue to reconsider AHR as a pharmacological target and could lead to the development of mechanism-based drugs for AD. PMID:23348739

  16. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    SciTech Connect

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  17. Coal-tar-based pavement sealcoat—Potential concerns for human health and aquatic life

    USGS Publications Warehouse

    Mahler, Barbara J.; Woodside, Michael D.; Van Metre, Peter C.

    2016-04-20

    Aquatic Life Concerns—Runoff from coal-tar-sealcoated pavement, even runoff collected more than 3 months after sealcoat application, is acutely toxic to fathead minnows and water fleas, two species commonly used to assess toxicity to aquatic life. Exposure to even highly diluted runoff from coal-tar-sealcoated pavement can cause DNA damage and impair DNA repair. These findings demonstrate that coal-tar-sealcoat runoff can remain a risk to aquatic life for months after application.

  18. Criteria for Coal Tar Seal Coats on Airport Pavements. Volume 1. State of the Art

    DTIC Science & Technology

    1987-03-01

    subject of extensive technical discussions as have other bituminous products. Major companies discontinued marketing coal tar emulsions during the oil ...through the effects of oxidation and sunlight, whereas coal tar appears to weather through the evaporation of oils . Reference (13) reports some of the...gal) (gal) (gal) (lb/gal coal tar) 1 WC No 2 Yes 100 80 8.2 latex with silicone 13 2 WC No I Yes 100 80 8.2 latex with silicone 13 3 WC Poly oil 2

  19. Coal tar creosote abuse by vapour inhalation presenting with renal impairment and neurotoxicity: a case report.

    PubMed

    Hiemstra, Thomas F; Bellamy, Christopher Oc; Hughes, Jeremy H

    2007-09-24

    A 56 year old aromatherapist presented with advanced renal failure following chronic coal tar creosote vapour inhalation, and a chronic tubulo-interstitial nephritis was identified on renal biopsy. Following dialysis dependence occult inhalation continued, resulting in seizures, ataxia, cognitive impairment and marked generalised cerebral atrophy. We describe for the first time a case of creosote abuse by chronic vapour inhalation, resulting in significant morbidity. Use of the polycyclic aromatic hydrocarbon-containing wood preservative coal tar creosote is restricted by many countries due to concerns over environmental contamination and carcinogenicity. This case demonstrates additional toxicities not previously reported with coal tar creosote, and emphasizes the health risks of polycyclic aromatic hydrocarbon exposure.

  20. A feasibility study to use coal tar contaminated soil in asphalt cement mixture production

    SciTech Connect

    Dulam, C.S.; Hoag, G.E.; Dahmani, A.; Nadim, F.

    1996-11-01

    Coal tars are the residues produced during the gasification of coal. Traditionally, coal tars were buried onsite at the power plants or left as residuals in the bottom of gas holders. Currently, there are more than 1,500 such historic sites which will undergo site assessment in the near future. The use of coal tar residuals in asphalt-based products could result in greatly reduced disposal costs, in comparison to current methods of disposal. Present disposal practice of coal tar contaminated residuals includes disposal in hazardous waste landfills or incineration. Treatment and disposal costs are reported to be as much as $1,000/ton for current coal tar contaminated residuals disposal options. This feasibility study was performed to determine the use of coal tar contaminated soil (CTCS) in bituminous materials to produce hot asphalt mix. Mixtures of varying composition of CTCS and bituminous material were produced to perform TCLP. The air emissions during the mixing process were captured and analyzed. In this study, a bench scale investigation was performed to identify and quantify the emissions from heating the CTCS at the mixer temperature. The pilot scale investigations were performed by replacing reclaimable asphalt pavement (RAP) with CTCS during the hot asphalt mix production. The investigations were performed on two types of mixtures; using CTCS as the direct additive in the first type, and using SS-1 (slow setting asphalt emulsion) stabilized CTCS as an additive in the second type.

  1. Coal tar, material used in soil improvement for use in road engineering

    NASA Astrophysics Data System (ADS)

    Ochoa Díaz, R.; Montañez, A.; Cuentas, J.

    2016-02-01

    Coal tar is a by-product of coal distillation in the absence of oxygen to obtain metallurgical coke; its colour varies from dark coffee to black, slightly viscous and its density is greater than that of water. Taking into account the previous characteristics, this document presents a study of the feasibility of using coal tar for the improvement of physical properties, mechanics and dynamics of materials used in road engineering. In this way, the origin, characteristics, and properties of tar are first described. Next, its combination with which granular-based material is evaluated through the CBR test procedure to determine its resistance and to compare it with the non-stabilized material. Finally, the behaviour of the material when subjected to dead loads by means of resistant modules found with the NAT (Nottingham Asphalt Tester) is explored. As a result, the option of using coal tar as a stabilizer was identified due to its use under specific conditions.

  2. Relation Between PAHs and Coal-Tar-Based Pavement Sealant in Urban Environments (Invited)

    NASA Astrophysics Data System (ADS)

    Mahler, B. J.; van Metre, P. C.

    2010-12-01

    Since 2003, coal-tar-based sealant products have come under increased scrutiny as a source of PAHs in urban environments. Sealant (or sealcoat) is the black, shiny substance often applied to asphalt pavement, in particular parking lots and driveways, for esthetic and maintenance purposes. Coal-tar-based sealant, one of the two primary pavement sealant types on the market, typically is 20-35 percent coal-tar pitch, a known carcinogen that is more than 50 percent polycyclic aromatic hydrocarbons (PAHs). The PAH content of the coal-tar-based sealant product is about 1,000 times that of a similar, asphalt-based product, on average. This difference is reflected in regional differences in sealant use and PAH concentrations in pavement dust. In the central and eastern U.S., where the coal-tar-based formulation is prevalent, ΣPAH in mobile particles from sealed pavement have been shown to be about 1,000 times higher than in the western U.S., where the asphalt-based formulation is prevalent (the median ΣPAH concentrations are 2,200 mg/kg in the central and eastern U.S. and 2.1 mg/kg in the western U.S.). Source apportionment modeling indicates that, in the central and eastern U.S., particles from sealed pavement are contributing the majority of the PAHs in recently deposited (post-1990) lake sediment, with implications for ecological health, and that coal-tar-based sealant is the primary cause of upward trends in PAHs in U.S. urban lakes. From the standpoint of human health, research indicates that mobile particles from parking lots with coal-tar-based sealant are tracked indoors, resulting in elevated PAH concentrations in house dust. Coal-tar-based sealcoat being applied to an asphalt parking lot at the University of Texas Pickle Research Center.

  3. Toxicity of coal-tar pavement sealants and ultraviolet radiation to Ambystoma Maculatum.

    PubMed

    Bommarito, Thomas; Sparling, Donald W; Halbrook, Richard S

    2010-08-01

    Polycyclic aromatic hydrocarbons (PAHs) can affect amphibians in lethal and many sublethal ways. There are many natural and anthropogenic sources of PAHs in aquatic environments. One potentially significant source is run off from surfaces of parking lots and roads that are protected with coal tar sealants. Coal tar is 50% or more PAH by wet weight and is used in emulsions to treat these surfaces. Break down of sealants can result in contamination of nearby waters. The toxicity of PAHs can be greatly altered by simultaneous exposure to ultraviolet radiation. This study exposes larvae of the spotted salamander (Ambystoma maculatum) to determine if coal tar sealant can have negative effects on aquatic amphibians and if coal tar toxicity is influenced by ultraviolet radiation. Spotted salamanders were exposed to 0, 60, 280 and 1500 mg coal tar sealant/kg sediment for 28 days. Half of the animals were exposed to conventional fluorescent lighting only and half were exposed to fluorescent lighting plus ultraviolet radiation. No significant mortality occurred during the experiment. Exposure to sealants resulted in slower rates of growth, and diminished ability to swim in a dose-dependent fashion. Exposure to ultraviolet radiation affected the frequencies of leukocytes and increased the incidence of micronucleated erythrocytes. There was an interactive effect of sealant and radiation on swimming behavior. We conclude that coal-tar sealant and ultraviolet radiation increased sublethal effects in salamanders, and may be a risk to salamanders under field conditions.

  4. Flood-induced transport of PAHs from streambed coal tar deposits.

    PubMed

    Vulava, Vijay M; Vaughn, D Syreeta; McKay, Larry D; Driese, Steven G; Cooper, Lee W; Menn, Fu-Min; Levine, Norman S; Sayler, Gary S

    2017-01-01

    We assessed whether coal tar present in contaminated streambed sediments can be mobilized by flood events and be re-deposited in an adjacent floodplain. The study was conducted within a contaminated urban stream where coal tar wastes were released into a 4-km reach from a coke plant in Chattanooga, Tennessee, USA. Sediments containing visible amounts of coal tar were dredged from the streambed in 1997-98 and 2007 as part of a cleanup effort. However, post-dredging sampling indicated that very high concentrations of polycyclic aromatic hydrocarbons (PAHs) remained in streambed sediments. Sampling of sediments in the floodplain at two sites downstream of the coke plant indicated that high concentrations of PAHs were also present in the floodplain, even though no coal tar was observed in the samples. Age-dating of the floodplain sediments using (137)Cs indicated that peak PAH concentrations were contemporary with coke plant operations. While there was little or any direct contamination of the floodplain sediments by coal tar, sediment contamination was likely a result of deposition of suspended streambed sediments containing sorbed PAHs. A flood model developed to delineate the extent of flooding in various flood recurrence scenarios confirmed the potential for contaminated streambed sediments to be transported into the adjacent floodplain. It was hypothesized that coal tar, which was visibly "sticky" during dredging-based stream cleanup, may act as a binding agent for streambed sediments, decreasing mobility and transport in the stream. Therefore, coal tar is likely to remain a persistent contaminant source for downstream reaches of the stream and the adjacent floodplain during flood events. This study also showed that even after excavation of tar-rich streambed sediments, PAH contaminated non-tarry sediments may be a source of flood-related contamination in the adjacent flood plain. A conceptual framework was developed to delineate specific mechanisms that can

  5. Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene

    SciTech Connect

    Gaylor, D.W.; Culp, S.J.; Goldstein, L.S.; Beland, F.A.

    2000-02-01

    Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk < 1.03 x 10{sup {minus}4} (ppm coal tar in total diet) + 240 x 10{sup {minus}4} (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk < 2.55 x 10{sup {minus}4} (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10{sup {minus}3} per {micro}g per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10{sup {minus}3} per {micro}g per kg body weight per day listed in the US EPA Integrated Risk Information System.

  6. Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene.

    PubMed

    Gaylor, D W; Culp, S J; Goldstein, L S; Beland, F A

    2000-02-01

    Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk < 1.03 x 10(-4) (ppm coal tar in total diet) + 240 x 10(-4) (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk < 2.55 x 10(-4) (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10(-3) per microgram per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10(-3) per microgram per kg body weight per day listed in the U.S. EPA Integrated Risk Information System.

  7. [The effect of occupational exposure to coal tar pitch workers' health].

    PubMed

    Sun, X C; Zhang, F; Zhang, W; Lu, C D; Zhang, Z H; Feng, B; Wei, H Y; Meng, X; Chen, X L; Shao, H; Wang, Z X

    2016-11-20

    Objective: To investigate the effect of occupational exposure to coal tar pitch on workers' health and metabolism. Methods: 805 workers exposed to coal tar pitch were selected as exposure group from the produce and em-ploy factory. Other people handle administrative and logistical affairs who not exposed to coal tar pitch were selected as control group. Fix-point sample of air were collected to detect the concentration of coal tar pitch. Do physical examination and questionnaire to collect workers' basic and healthy information. To detect the metabolic product of urine samples in laboratory. Results: Anomaly detection rate of the skin in exposure group is 10.61. The lung function indices (FEV1.0%) in exposure group were significantly lower than control group (P<0.05) . The monocyte count and monocyte rate in expo-sure group were significantly higher than control group (P<0.05) . The metabolic product content of PAHS in urine sam-ples is significantly higher in exposed group than control group (P<0.05) . Conclusion: The metabolic product content of polycyclic aromatic hydrocarbon is higher in exposed workers. Coal tar pitch damage workers' skin and lung function. It can cause pruritus chromatodermatosis and so on.

  8. PAHs and organic matter partitioning and mass transfer from coal tar particles to water

    SciTech Connect

    Karim Benhabib; Marie-Odile Simonnot; Michel Sardin

    2006-10-01

    The coal tar found in contaminated soils of former manufactured gas plants and coking plants acts as a long-term source of PAHs. Organic carbon and PAH transfer from coal tar particles to water was investigated with closed-looped laboratory column experiments run at various particle sizes and temperatures. Two models were derived. The first one represented the extraction process at equilibrium and was based on a linear partitioning of TOC and PAHs between coal tar and water. The partition coefficient was derived as well as the mass of extractable organic matter in the particles. The second model dealt with mass transfer. Particle diffusion was the limiting step; organic matter diffusivity in the coal tar was then computed in the different conditions. A good consistency was obtained between experimental and computed results. Hence, the modeling of PAH migration in contaminated soils at the field scale requires taking into account coal tar as the source-term for PAH release. 28 refs., 5 figs., 3 tabs.

  9. Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens.

    PubMed

    Bommarito, Thomas; Sparling, Donald W; Halbrook, Richard S

    2010-09-01

    Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg(-1), much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg(-1) to 1500 mg kg(-1) under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

  10. Partition behavior of polycyclic aromatic hydrocarbons between aged coal tar and water

    SciTech Connect

    Liu, L.H.; Endo, S.; Eberhardt, C.; Grathwohl, P.; Schmidt, T.C.

    2009-08-15

    Coal tar aged in a large-scale, artificial aquifer experiment for five years was subsequently investigated for leaching behavior of polycyclic aromatic hydrocarbons (PAHs). After five years, the initially liquid coal tar had solidified and formed segregated particles with a grain size similar to that of the sandy aquifer material. The composition of the aged coal tar (ACT) with regard to PAHs was remarkably different from that of the original bulk coal tar (BCT), because most of the low-molecular-weight compounds had been depleted. Equilibrium aqueous-phase concentrations of 17 PAHs leaching from the aquifer material containing the ACT were measured from consecutive equilibration steps at increasing temperatures of between 25 and 100 {sup o}C using accelerated solvent extraction. The results showed 2-to 5,000-fold lower concentrations than those from BCT, indicating dramatic changes of dissolution behavior of PAHs from coal tar after the five-year aging period. Predictions based on Raoult's law with the subcooled liquid solubilities substantially overestimated the equilibrium aqueous-phase concentrations of the PAHs from ACT, whereas the estimations were reasonable if the solid solubilities were employed instead. The enthalpies of phase transfer from ACT to water were determined based on the van't Hoff equation. The resulting values agreed with the dissolution enthalpies of pure solid rather than subcooled liquid PAHs.

  11. A photographic method for estimating wear of coal tar sealcoat from parking lots

    SciTech Connect

    Mateo Scoggins; Tom Ennis; Nathan Parker; Chris Herrington

    2009-07-01

    Coal-tar-based sealcoat has been recognized as an important source of PAHs to the environment through wear and transport via stormwater runoff. Sealcoat removal rates have not been measured or even estimated in the literature due to the complex array of physical and chemical process involved. A photographic study was conducted that incorporates all sources of wear using 10 coal tar-sealed parking lots in Austin, Texas, with sealcoat age ranging from 0 to 5 years. Randomly located photographs from each parking lot were analyzed digitally to quantify black sealed areas versus lighter colored unsealed areas at the pixel level. The results indicate that coal tar sealcoat wears off of the driving areas of parking lots at a rate of approximately 4.7% per year, and from the parking areas of the lots at a rate of approximately 1.4% per year. The overall annual loss of sealcoat was calculated at 2.4%. This results in an annual delivery to the environment of 0.51 g of PAHs per m{sup 2} of coal tar-sealed parking lot. These values provide a more robust and much higher estimate of loading of PAHs from coal tar sealcoated parking lots when compared to other available measures. 20 refs., 6 figs.

  12. A photographic method for estimating wear of coal tar sealcoat from parking lots.

    PubMed

    Scoggins, Mateo; Ennis, Tom; Parker, Nathan; Herrington, Chris

    2009-07-01

    Coal-tar-based sealcoat has been recognized as an important source of PAHs to the environment through wear and transport via stormwater runoff. Sealcoat removal rates have not been measured or even estimated in the literature due to the complex array of physical and chemical process involved. A photographic study was conducted that incorporates all sources of wear using 10 coal tar-sealed parking lots in Austin, Texas, with sealcoat age ranging from 0 to 5 years. Randomly located photographs from each parking lot were analyzed digitally to quantify black sealed areas vs lighter colored unsealed areas at the pixel level. The results indicate that coal tar sealcoat wears off of the driving areas of parking lots at a rate of approximately 4.7% per year, and from the parking areas of the lots at a rate of approximately 1.4% per year. The overall annual loss of sealcoat was calculated at 2.4%. This results in an annual delivery to the environment of 0.51 g of PAHs per m2 of coal tar-sealed parking lot. These values provide a more robust and much higher estimate of loading of PAHs from coal tar sealcoated parking lots when compared to other available measures.

  13. Biogeochemical characterisation of a coal tar distillate plume.

    PubMed

    Williams, G M; Pickup, R W; Thornton, S F; Lerner, D N; Mallinson, H E; Moore, Y; White, C

    2001-12-15

    The distillation of acidified coal tars for up to 50 years has given rise to a phenol plume approximately 500 m long, 50 m deep and containing up to 15 g l(-1) dissolved organic carbon (DOC) in the Triassic Sandstones aquifer. A conceptual biogeochemical model based on chemical and microbiological analysis of groundwater samples has been developed as a preliminary to more detailed studies of the controls on natural attenuation. While the development of redox zones and the production of methane and carbon dioxide provide evidence of natural attenuation, it appears that degradation is slow. The existence of sulphate in the plume indicates that this electron acceptor has not been depleted and that consequently methanogenesis is probably limited. Based on a simple estimate of sulphate input concentration, a half-life of about 15 years has been estimated for sulphate reduction. Geochemical modelling predicts that increased alkalinity within the plume has not led to carbonate precipitation, and thus within the limits of accuracy of the measurement, alkalinity may reflect the degree of biodegradation. This implies a loss of around 18% of the DOC over a 30-year period. Despite limited degradation, microbial studies show that there are diverse microbial communities in the aquifer with the potential for both anaerobic and aerobic biodegradation. Microbial activity was found to be greatest at the leading edge of the plume where DOC concentrations are 60 mg l(-1) or less, but activity could still be observed in more contaminated samples even though cells could not be cultured. The study suggests that degradation may be limited by the high phenol concentrations within the core of the plume, but that once diluted by dispersion, natural attenuation may proceed. More detailed studies to confirm these initial findings are identified and form the basis of associated papers.

  14. Analysis of coal tar pitch and smoke extract components and their cytotoxicity on human bronchial epithelial cells.

    PubMed

    Li, Zhitao; Wu, Yongjun; Zhao, Yong; Wang, Lixia; Zhu, Hansong; Qin, Lijuan; Feng, Feifei; Wang, Wei; Wu, Yiming

    2011-02-28

    Coal tar pitch and its smoke are considered hazardous by-products and common pollutant generated from coal industry processing. In this study, coal tar pitch and its smoke extracts were characterized by gas chromatography/mass spectrometry (GC/MS) with dimethylsulfoxide. We identified only 0.3025% of components in the total coal tar pitch using GC/MS. Among 18 identified compounds, polycyclic aromatic hydrocarbons (PAHs) has the highest relative abundance (0.19%). The remaining components were composed of monocyclic aromatic hydrocarbons, heterocyclic compounds and alkenes. In contrast, among 38 coal tar pitch smoke extract constituents that have been profiled, 87.91% were PAHs, and the remaining 12.09% were composed of monocyclic aromatic hydrocarbons, heterocyclic compounds and alkenes. The cytotoxic effect of coal tar pitch and its smoke extracts on BEAS-2B cells were also evaluated by MTT assay. BEAS-2B cells exposed to coal tar pitch showed a non dose-dependent U-shaped cytotoxicity with a dosage for maximal inhibitory of 3.75 mg/L. In contrast, BEAS-2B cells exposed to coal tar pitch smoke extracts showed a dose dependent cytotoxicity with a LC(50) of 8.64 mg/L. Our study demonstrated the significant different composition and cytotoxicity of coal tar pitch and its extracts, suggesting two different underlying mechanisms that are pending future investigation.

  15. Technology for the production of Zero Q.I pitch from coal tar

    NASA Astrophysics Data System (ADS)

    Karthik, K.; Kumar, K. Rajesh; Rao, C. V. Nageswara; Kumar, B. Vinod; Murty, J. V. S.

    2013-06-01

    Zero Quinoline Insolubles (Q.I) pitch is a special type of pitch obtained from pre-treatment of coal tar, which is converted into pitch. This is used for impregnation of electrodes for improving the strength, electrical properties and also used as a pre-cursor for Mesophase pitch for producing Mesophase pitch based carbon fibers, carbon foam, and Meso carbon micro beads. This paper discusses the technology of Q.I separation from Coal Tar by using decantation of Coal Tar mixed with Heavy Creosote Oil (HC Oil) at different temperatures. By this method we were able to produce the Zero Q.I pitch with a Q.I value of 0.1%.

  16. Coal tar creosote abuse by vapour inhalation presenting with renal impairment and neurotoxicity: a case report

    PubMed Central

    Hiemstra, Thomas F; Bellamy, Christopher OC; Hughes, Jeremy H

    2007-01-01

    A 56 year old aromatherapist presented with advanced renal failure following chronic coal tar creosote vapour inhalation, and a chronic tubulo-interstitial nephritis was identified on renal biopsy. Following dialysis dependence occult inhalation continued, resulting in seizures, ataxia, cognitive impairment and marked generalised cerebral atrophy. We describe for the first time a case of creosote abuse by chronic vapour inhalation, resulting in significant morbidity. Use of the polycyclic aromatic hydrocarbon-containing wood preservative coal tar creosote is restricted by many countries due to concerns over environmental contamination and carcinogenicity. This case demonstrates additional toxicities not previously reported with coal tar creosote, and emphasizes the health risks of polycyclic aromatic hydrocarbon exposure. PMID:17892538

  17. Feasibility for the use of coal tar as a new material for road surfaces (pavement) construction

    NASA Astrophysics Data System (ADS)

    Romero Farfán, M. A.; Murillo Vega, H. E.; Trujillo Pinto, F. A.

    2016-02-01

    The stabilization products often used to improve the support of granular layers in the construction of road surfaces may be expensive and difficult to get. Therefore, it is necessary to test different materials, which are cheap and easy to obtain, and which will enhance the physical and mechanical properties of pavement layers. This document evaluates the use of coal tar, as a stabilizer for granular subbase. Initially, with a description of tar properties, determining the optimal conditions for the granular subbase material compaction, by means of modified proctor tests and the calculation of the resistance of the unaltered material by using CBR lab tests (California Bearing Ratio). Afterwards, with the design and development of granular material mixes with different percentages of coal tar and determining its CBR as comparative parameter with that of the unaltered material. Finally, by calculating the optimal coal tar percentage in order to stabilize the subbase granular, the results showed an improvement in the resistance of the granular material and a decrease in its expansion due to the use of coal tar.

  18. Effects of model coal tar components on adhesion strength of polyurethane coating on steel plate

    SciTech Connect

    Yokoyama, N.; Fujino, K.

    2005-04-15

    In order to study the effects of coal tar components on the adhesion strength of a heavy duty anticorrosive coating formed with tar-urethane resin oil on a steel plate, polyurethane coatings that were compounded with 15 kinds of polycyclic aromatic compounds as model coal tar components were prepared. In the model coal tar, components, naphthalene, quinoline, 2-naphthol, and phenanthrene showed good compatibility with polyurethane. To test their heavy duty anticorrosive properties, tensile adhesion strength of the cured coatings prepared with the compatible model coal tar components was measured, and the change in tensile adhesion strength as a function of time during salt-water spray treatment was measured. We found that the systems compounded with naphthalene, 2-naphthol, and phenanthrene showed good properties in an ordinary state for adhesion strength. However, only the system with 2-naphthol was found to have good properties in the change of tensile adhesion strength as a function or time during salt-water spray treatment. The curing time of the system with 2-naphthol was slower than that or the others, i.e., we found an inverse proportion between curing speed and adhesion durability. We also measured the dynamic viscoelasticity of cured coatings.

  19. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, July 1--September 30, 1995

    SciTech Connect

    Suuberg, E.M.

    1995-12-31

    There is significant current interest in general area of coal pyrolysis, particularly because of the central role of pyrolysis in all thermally driven coal conversion processes-gasification, combustion, liquefaction, mild gasification, or thermal beneficiation. There remain several key data needs in these application areas. Among them is a need for more reliable correlation for prediction of vapor pressure of heavy, primary coal tars. The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. A significant amount of time has been devoted during this quarter to extending the work on measurements of vapor pressures of tars. For this purpose, cellulose tar and cellulose tar related compounds have been selected as model systems. Cellulose tar has a much narrower distribution of molecular weight than does coal tar, and it is much more homogeneous. Thus it is better to develop the methods to be used for coal tars on this simpler model system first.

  20. Skin cancer in patients with psoriasis treated with coal tar. A 25-year follow-up study

    SciTech Connect

    Pittelkow, M.R.; Perry, H.O.; Muller, S.A.; Maughan, W.Z.; O'Brien, P.C.

    1981-08-01

    For many years, crude coal tar has been used for the treatment of psoriasis. The possible carcinogenic effect of crude coal tar and ultraviolet (UV) radiation (Goeckerman regimen), considered individually or in combination, has been of some concern to physicians. A 25-year follow-up study was completed on 280 patients with psoriasis who were hospitalized and treated with crude coal tar and UV radiation at the Mayo Clinic, Rochester, Minn, during the years 1950 through 1954. The results of this study suggest that the incidence of skin cancer is not appreciably increased above the expected incidence for the general population when patients are treated with coal tar ointments. It seems that the Goeckerman regimen (topical crude coal tar combined with UV radiation) can be used with minimal risk for skin cancer in the treatment of psoriasis.

  1. Coal tar phototoxicity: characteristics of the smarting reaction

    SciTech Connect

    Diette, K.M.; Gange, R.W.; Stern, R.S.; Arndt, K.A.; Parrish, J.A.

    1985-04-01

    The properties and ultraviolet exposure parameters of tar smarts were examined in an effort to elucidate the mechanisms involved. It was show that irradiation with 1 minimal smarting dose (MSD) of UVA immediately following tar removal lowered the MSD for 6 h, demonstrated by subsequent challenge with UVA. Following 3 MSDs this memory effect was demonstrable for 24 h. The smarting reaction was area dependent--smaller areas of exposure require higher doses of UVA to induce smarting. Smarting followed reciprocity over a 6-fold range of irradiances (2-12.5 mW/cm2) but higher irradiances required higher doses of UVA, perhaps due to a delay in the recognition and reporting of smarting. The smarting reaction and delayed erythema due to UVA and tar were equally blocked by sunscreen.

  2. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, July 1 - September 31, 1996

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1996-12-31

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude. This project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal; (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars; and (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. During this quarter we have extended the work on measurements of vapor pressures of coal tars, using the continuous Knudsen effusion technique. These results need further analysis and therefore in this report we describe only the general idea behind the technique, and also show some typical results.

  3. Analysis of the use of coal tar as a binder in bituminous mixtures, using Marshall and Ramcodes methodologies

    NASA Astrophysics Data System (ADS)

    Ochoa-Díaz, R.

    2013-11-01

    This paper presents an alternative use of coal tar, a by-product of the steel industry, given the problems of accumulation and negative environmental impact. Therefore, it is necessary to analyze the incorporation of coal tar as a binder in paving mixtures. First, this paper presents the origin, description of the main characteristics, and properties of tar. Then, this paper evaluates the mix of coal tar by means of the RAMCODES and Marshall methodologies to determine its resistance. The results of the tests explain the physical and mechanical properties of the mix. Taking into account the results of both methods, this paper makes a comparison to determine the suitability of the RAMCODES methodology in the mix design. Finally, it analyzes the alternatives to coal tar that can be used as binders in bituminous mixes for pavement and the advantages of their uses under some specific conditions.

  4. PAHs underfoot: Contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    USGS Publications Warehouse

    Van Metre, P.C.; Mahler, B.J.; Wilson, J.T.

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U. S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat Dust was swept from parking lots in six cities in the central and eastern U. S., where coal-tar-based sealcoat dominates use, and three cities in the western U. S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2. 1 and 0. 8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  5. Time scales of organic contaminant dissolution from complex source zones: coal tar pools vs. blobs

    NASA Astrophysics Data System (ADS)

    Eberhardt, Christina; Grathwohl, Peter

    2002-11-01

    Groundwater contamination due to complex organic mixtures such as coal tar, creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal tar pool and 0.5 m long (smear) zone containing coal tar blobs distributed in a coarse sand. The results indicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3-5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (<0.1 mm), the transverse vertical dispersivity dominates the pool dissolution processes. Typical time scales for removal of the pollutants from the blob zone and the pool are in the order of a few weeks to more than 10,000 years, respectively.

  6. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing any...

  7. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing any...

  8. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing any...

  9. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing any...

  10. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing any...

  11. Coal tar residues produce both DNA adducts and oxidative DNA damage in human mammary epithelial cells.

    PubMed

    Leadon, S A; Sumerel, J; Minton, T A; Tischler, A

    1995-12-01

    In the present study we compare the metabolic activation of coal tar, as measured by the production of both DNA adducts and oxidative DNA damage, with that of a single carcinogen that is a constituent of this complex mixture in human mammary epithelial cells (HMEC). We find that a significant level of DNA adducts, detected by 32P-postlabeling, are formed in HMEC following exposure to coal tar residues. This treatment also results in the generation of high levels of oxidative DNA damage, as measured by the production of one type of oxidative base modification, thymine glycols. The amounts of both DNA adducts and thymine varied considerably between the various coal tar residues and did not correlate with either the total amount of polycyclic aromatic hydrocarbons (PAH) or the amount of benzo[a]pyrene (B[a]P) present in the residue. Fractionating the residue from one of the sites by sequential extraction with organic solvents indicated that while the ability to produce both types of DNA damage was contained mostly in a hexane-soluble fraction, a benzene-soluble fraction produced high levels of reactive oxygens relative to the number of total DNA adducts. We find that the total amount of PAH or B[a]P present in the coal tars from the various sites was not a predictor of the level of total DNA damage formed.

  12. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  13. Extraction of coal tar pitch using a mixture of compressed CO[sub 2] and toluene

    SciTech Connect

    White, K.L.; Knutson, B.L.; Kimber, G. )

    1999-09-01

    The removal of low-molecular-weight components from commercial pitches is a critical step in the production of suitable precursors for isotropic carbon fiber formation. A unique extraction process employing a one-phase binary mixture of carbon dioxide and toluene has been developed to remove low-molecular-weight components from coal tar pitch, with an ultimate goal of increasing the softening point of the pitch. The mass fraction of coal tar pitch extracted was determined as a function of extraction temperature (25--75 C), pressure (8.7--14.9 MPa), and extractive solvent composition (40--70 wt % toluene) using a factorial experimental design. As much as 44 wt % of the coal tar pitch was removed at these extraction conditions, and softening points greater than 250 C were achieved. The separation is controlled by the temperature and composition of the extractant solvent. This compressed gas/organic solvent extraction process removes low-molecular-weight material from the coal tar pitch using significantly milder solvents and reduced temperatures relative to traditional extractive processes.

  14. Extraction of coal tar pitch using a mixture of compressed CO{sub 2} and toluene

    SciTech Connect

    White, K.L.; Knutson, B.L.; Kimber, G.

    1999-09-01

    The removal of low-molecular-weight components from commercial pitches is a critical step in the production of suitable precursors for isotropic carbon fiber formation. A unique extraction process employing a one-phase binary mixture of carbon dioxide and toluene has been developed to remove low-molecular-weight components from coal tar pitch, with an ultimate goal of increasing the softening point of the pitch. The mass fraction of coal tar pitch extracted was determined as a function of extraction temperature (25--75 C), pressure (8.7--14.9 MPa), and extractive solvent composition (40--70 wt % toluene) using a factorial experimental design. As much as 44 wt % of the coal tar pitch was removed at these extraction conditions, and softening points greater than 250 C were achieved. The separation is controlled by the temperature and composition of the extractant solvent. This compressed gas/organic solvent extraction process removes low-molecular-weight material from the coal tar pitch using significantly milder solvents and reduced temperatures relative to traditional extractive processes.

  15. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    SciTech Connect

    Peter C. Van Metre; Barbara J. Mahler; Jennifer T. Wilson

    2009-01-15

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of {Sigma}PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo(a)pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. 30 refs., 4 figs., 2 tabs.

  16. Implication of Coal Tar and Asphalt on Black Carbon Quantification in Urban Watersheds

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Werth, C. J.; Ligouis, B.; Razzaque, M.

    2008-12-01

    Sorption to black carbon (BC) is an important process that controls the transport and fate of persistent organic pollutants in aquatic environments. Efforts have been made to measure BC in different environmental matrices including aerosols, soils, and sediments; however, few studies have attempted to evaluate BC in dust from urban streets or parking lots, which can be an important BC source in urban lake sediments. Methods to quantify BC in soils and sediments usually involve the removal of non-BC carbonaceous materials with chemical and/or thermal oxidation followed by elemental analysis. The presence of coal tar pitch and asphalt in urban pavement dust is hypothesized to potentially result in an overestimate of BC. The primary objectives of this research are to identify the distribution of BC in a small urban watershed and to investigate the potential interference from coal tar and asphalt on BC quantification by method intercomparison. Samples were collected from the Lake Como watershed in Fort Worth, Texas. They include dust from coal-tar-sealed and unsealed parking lots and residential streets, soils from residential and commercial areas, stream bed sediments, and lake sediment cores. After density separation, samples were subjected to sequential chemical treatments and thermal treatment. Commercial coal tar pitch and asphalt products were subjected to these same treatments for comparison. BC contents quantified with chemical treatment and chemo-thermal oxidation at 375°C (CTO-375) were compared with those characterized using organic petrography. The chemical treatment predicted greater BC contents than organic petrography in all samples, and the greatest difference is in the sealed parking lot dust. CTO-375 method also predicted greater BC content in this sample than organic petrography. Commercial coal tar pitch was resistant to thermal oxidation and both coal tar pitch and asphalt were resistant to the chemical treatment. These results indicate that

  17. Potential contributions of asphalt and coal tar to black carbon quantification in urban dust, soils, and sediments

    USGS Publications Warehouse

    Yang, Y.; Mahler, B.J.; Van Metre, P.C.; Ligouis, B.; Werth, C.J.

    2010-01-01

    Measurements of black carbon (BC) using either chemical or thermal oxidation methods are generally thought to indicate the amount of char and/or soot present in a sample. In urban environments, however, asphalt and coal-tar particles worn from pavement are ubiquitous and, because of their pyrogenic origin, could contribute to measurements of BC. Here we explored the effect of the presence of asphalt and coal-tar particles on the quantification of BC in a range of urban environmental sample types, and evaluated biases in the different methods used for quantifying BC. Samples evaluated were pavement dust, residential and commercial area soils, lake sediments from a small urban watershed, and reference materials of asphalt and coal tar. Total BC was quantified using chemical treatment through acid dichromate (Cr2O7) oxidation and chemo-thermal oxidation at 375??C (CTO-375). BC species, including soot and char/charcoal, asphalt, and coal tar, were quantified with organic petrographic analysis. Comparison of results by the two oxidation methods and organic petrography indicates that both coal tar and asphalt contribute to BC quantified by Cr2O7 oxidation, and that coal tar contributes to BC quantified by CTO-375. These results are supported by treatment of asphalt and coal-tar reference samples with Cr2O7 oxidation and CTO-375. The reference asphalt is resistant to Cr2O7 oxidation but not to CTO-375, and the reference coal tar is resistant to both Cr2O7 oxidation and CTO-375. These results indicate that coal tar and/or asphalt can contribute to BC measurements in samples from urban areas using Cr2O7 oxidation or CTO-375, and caution is advised when interpreting BC measurements made with these methods. ?? 2010 Elsevier Ltd.

  18. Potential contributions of asphalt and coal tar to black carbon quantification in urban dust, soils, and sediments

    NASA Astrophysics Data System (ADS)

    Yang, Yaning; Mahler, Barbara J.; Van Metre, Peter C.; Ligouis, Bertrand; Werth, Charles J.

    2010-12-01

    Measurements of black carbon (BC) using either chemical or thermal oxidation methods are generally thought to indicate the amount of char and/or soot present in a sample. In urban environments, however, asphalt and coal-tar particles worn from pavement are ubiquitous and, because of their pyrogenic origin, could contribute to measurements of BC. Here we explored the effect of the presence of asphalt and coal-tar particles on the quantification of BC in a range of urban environmental sample types, and evaluated biases in the different methods used for quantifying BC. Samples evaluated were pavement dust, residential and commercial area soils, lake sediments from a small urban watershed, and reference materials of asphalt and coal tar. Total BC was quantified using chemical treatment through acid dichromate (Cr 2O 7) oxidation and chemo-thermal oxidation at 375 °C (CTO-375). BC species, including soot and char/charcoal, asphalt, and coal tar, were quantified with organic petrographic analysis. Comparison of results by the two oxidation methods and organic petrography indicates that both coal tar and asphalt contribute to BC quantified by Cr 2O 7 oxidation, and that coal tar contributes to BC quantified by CTO-375. These results are supported by treatment of asphalt and coal-tar reference samples with Cr 2O 7 oxidation and CTO-375. The reference asphalt is resistant to Cr 2O 7 oxidation but not to CTO-375, and the reference coal tar is resistant to both Cr 2O 7 oxidation and CTO-375. These results indicate that coal tar and/or asphalt can contribute to BC measurements in samples from urban areas using Cr 2O 7 oxidation or CTO-375, and caution is advised when interpreting BC measurements made with these methods.

  19. Thermal oxidation purification of gaseous emissions to remove tar vapor and coal dust

    SciTech Connect

    Zhilina, N.B.; Andreikov, E.I.

    1983-01-01

    In the production of molded coke one source of emissions of toxic substances is the excess heat carrier gas (640 m/sup 3/ per ton of charge). In addition to the gaseous components, it contains, g/m/sup 3/: water 360, tar vapor 3-5, coal dust 2-6. The goal of the present article was to evaluate the possibility of purifying this gas by thermal oxidation. The investigations were conducted on a laboratory apparatus with a quartz reactor (length 200 mm, diameter 14 mm), heated by a tube furnace. The tar is injected by a plunger metering pump into a gas mixture, where it is evaporated at 150/sup 0/C in a current of gas; then the tar vapors enter the reactor. The tar for oxidation was obtained in the low-temperature (600/sup 0/C) semicoking of coal; in the experiments a fraction (70 wt.% tar) with a boiling point up to 360/sup 0/C was used. The fraction contained 8% bases, 35% phenols, and 57% neutral part, consisting of paraffins, naphthenes, alkyl-substituted aromatic hydrocarbons and neutral oxygen-containing compounds.

  20. Effect of the bioemulsifier emulsan on naphthalene mineralization from coal tar in aqueous systems

    SciTech Connect

    Skubal, K.L.; Luthy, R.G.

    1994-09-01

    Coal tar in aerobic aqueous systems was treated with purified emulsan, the anionic heteropolysaccharide bioemulsifier produced by Acinetobacter calcoaceticus RAG-1; with inocula of various concentrations of stationary phase RAG-1 cells; or with cell-free broth from stationary phase RAG-1 cultures. Naphthalene mineralization by a mixed PAH-degrading population was measured by recovering {sup 14}CO{sub 2} evolved during biotransformation of the [{sup 14}C]naphthalene-labeled coal tar. There was no evidence of naphthalene mineralization by RAG- 1 cells alone. The addition of emulsan, RAG-1 inocula, or cell-free broth to systems containing the PAH-degrading population did not significantly affect naphthalene mineralization in any of the systems tested. Coal tar in these experiments was present either as a free dense nonaqueous phase liquid (DNAPL), or as DNAPL imbibed into microporous silica particles. Emulsification of the tar was not observed in either case. The presence or absence of microporous silica did not affect the extent or rate of naphthalene mineralization, nor did the concentration of RAG-1 inocula or the amount of broth added. The addition of cell-free broth, emulsan, or RAG-1 cells late in the experiments did not yield significantly different results compared to initial addition of these substances. Thus, emulsan and related fractions from RAG-1 cultures were ineffective in altering naphthalene mineralization in this study.

  1. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, April 1--June 30, 1995

    SciTech Connect

    Suuberg, E.M.

    1995-10-01

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. Both the gas saturation method and the Knudsen effusion method are being used. Results are presented for anthracene, naphthacene, pentacene, and a mixture of anthracene and perylene obtained using the effusion method.

  2. Preparation of Organic Light-Emitting Diode Using Coal Tar Pitch, a Low-Cost Material, for Printable Devices

    PubMed Central

    Yamaoka, Miki; Asami, Shun-suke; Funaki, Nayuta; Kimura, Sho; Yingjie, Liao; Fukuda, Takeshi; Yamashita, Makoto

    2013-01-01

    We have identified coal tar pitch, a very cheap organic material made from coal during the iron-making process, as a source from which could be obtained emissive molecules for organic light-emitting diodes. Coal tar pitch was separated by simple dissolution in organic solvent, and subsequent separation by preparative thin-layer chromatography was used to obtain emissive organic molecules. The retardation factor of preparative thin-layer chromatography played a major role in deciding the emission characteristics of the solution as photoluminescence spectra and emission-excitation matrix spectra could be controlled by modifying the solution preparation method. In addition, the device characteristics could be improved by modifying the solution preparation method. Two rounds of preparative thin-layer chromatography separation could improve the luminance of organic light-emitting diodes with coal tar pitch, indicating that less polar components are favorable for enhancing the luminance and device performance. By appropriate choice of the solvent, the photoluminescence peak wavelength of separated coal tar pitch could be shifted from 429 nm (cyclohexane) to 550 nm (chloroform), and consequently, the optical properties of the coal tar pitch solution could be easily tuned. Hence, the use of such multicomponent materials is advantageous for fine-tuning the net properties at a low cost. Furthermore, an indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/coal tar pitch/LiF/Al system, in which the emissive layer was formed by spin-coating a tetrahydrofuran solution of coal tar pitch on the substrate, showed a luminance of 176 cd/m2. In addition, the emission spectrum of coal tar pitch was narrowed after the preparative thin-layer chromatography process by removing the excess emissive molecules. PMID:23667539

  3. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States.

    PubMed

    Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer T

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dustfrom coal-tarsealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  4. Toxic and teratogenic effects of chemical class fractions of a coal-gasification electrostatic precipitator tar.

    PubMed

    Schultz, T W; Dumont, J N; Buchanan, M V

    1983-12-01

    Dimethyl sulfoxide slurries of a coal gasifier electrostatic precipitator tar and its chemical class fractions were assayed for their toxicity and teratogenicity using early embryos of the frog Xenopus laevis. Of the 5 tar fractions the ether-soluble base and polyaromatic were found to be the most teratogenic and the ether-soluble acid and ether-soluble base were the most toxic. The teratogenic effects of the raw tar suggest synergism. The toxic effects to newly metamorphosed froglets is 1-2 orders of magnitude less than those observed for embryos. Chemical analysis shows dihydroxybenzenes and organonitrogen compounds to be the major components of the acid and base fractions, respectively. The neutral fractions contain mainly alkyl-substituted two-ring hydrocarbons.

  5. Use of coal tar pitch and petroleum bitumen in the production of thermally expanded graphite (Short Communication)

    SciTech Connect

    T.P. Miloshenko; O.Yu. Fetisova; M.L. Shchipko; B.N. Kuznetsov

    2008-06-15

    The applicability of coal tar pitch and petroleum bitumen to the production of thermally expanded graphite was studied. The dependence of the coefficient of thermal expansion and the specific surface area on the amount of added substances was examined.

  6. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    EPA Science Inventory

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  7. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    EPA Science Inventory

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  8. Effect of cavitation on the properties of coal-tar pitch as studied by gas-liquid chromatography

    SciTech Connect

    M.I. Baikenov; T.B. Omarbekov; S.K. Amerkhanova

    2008-02-15

    The applicability of the cavitation-wave effect to coal-tar pitch processing is considered. The results of the GLC analysis of the test material before and after rotor-pulsation cavitation treatment are given. The organic matter of coal-tar pitch was found to degrade upon cavitation; as a result of this, the yields of light and medium fractions considerably increased. 5 refs., 2 figs., 4 tabs.

  9. Groundwater contamination by organic bases derived from coal-tar wastes

    USGS Publications Warehouse

    Pereira, W.E.; Rostad, C.E.; Garbarino, J.R.; Hult, M.F.

    1983-01-01

    A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed. ?? 1983.

  10. Ground-water contamination by organic bases derived from coal-tar wastes

    USGS Publications Warehouse

    Pereira, Wilfred E.; Rostad, Colleen E.; Garbarino, John R.; Hult, Marc F.

    1983-01-01

    A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed.

  11. Study of coal tar pitch microstructure by using spin probe technique

    SciTech Connect

    Shklyaev, A.A.; Ugay, M.Y.

    1994-12-31

    One of the copper porphyrin complexes has been adopted as a spin probe in order to provide insight into the nature of paramagnetic species of coal tar pitch. It was found that there are three kinds of nonequivalent radical centers displaying a different sensitivity to the spin probes. The majority of radical centers in original coal tar pitch cannot be detected in E.S.R. spectra due to considerable broadening of its lines. These invisible centers give rise to sudden broadening of E.S.R. signals of complex dissolved in the pitch heated over 400 C. The questions regarding the nature of radical states and the reason of abrupt high temperature broadening of pitch signals are discussed.

  12. Coal-tar pavement sealants might substantially increase children's PAH exposures

    USGS Publications Warehouse

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Dietary ingestion has been identified repeatedly as the primary route of human exposure to polycyclic aromatic hydrocarbons (PAHs), seven of which are classified as probable human carcinogens (B2 PAHs) by the U.S. EPA. Humans are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air, and absorption through skin. Although PAH sources are ubiquitous in the environment, one recently identified PAH source stands out: Coal-tar-based pavement sealant—a product applied to many parking lots, driveways, and even playgrounds primarily in the central, southern, and eastern U.S.—has PAH concentrations 100–1000 times greater than most other PAH sources. It was reported recently that PAH concentrations in house dust in residences adjacent to parking lots with coal-tar-based sealant were 25 times higher than in residences adjacent to unsealed asphalt parking lots.

  13. Fluoranthene, a volatile mutagenic compound, present in creosote and coal tar.

    PubMed

    Bos, R P; Prinsen, W J; van Rooy, J G; Jongeneelen, F J; Theuws, J L; Henderson, P T

    1987-03-01

    Creosote, a coal-tar distillation product, contains mutagens which are volatile at 37 degrees C. After distillation of creosote we found that these volatile mutagens were present in the distillation fraction with the highest boiling range (greater than 360 degrees C). The "volatile mutagenic activity" was connected with the presence of fluoranthene, a polycyclic aromatic hydrocarbon. Commercially available fluoranthene was positive in the so-called "taped-plate assay" (the test system used for the detection of volatile mutagens) towards the strains TA98 and TA100 in the presence of S9 mix. The tested creosote and coal tar contained fluoranthene in concentrations of 5.2 and 2.2%, respectively.

  14. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement

    USGS Publications Warehouse

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

  15. Remediation of Coal Tar by STAR: Self-Sustaining Propagation Across Clean Gaps

    NASA Astrophysics Data System (ADS)

    Gerhard, J.; Brown, J.; Torero, J. L.; Grant, G.

    2016-12-01

    Self-sustaining Treatment for Active Remediation (STAR) is an emerging remediation technique which utilizes a subsurface smouldering reaction to destroy non-aqueous phase liquids (NAPL) in situ. The reaction is self-sustaining in that, once ignited, the destructive smouldering front will propagate outwards using only the energy embedded in the contaminant. However, it is known that coal tar can occur as both a continuous pool as well as in distinct seams separated by clean intervals. This study evaluated the hypothesis that the smouldering reaction can cross or `jump' clean gaps by transferring enough heat through the gap to re-ignite the reaction in the contaminated region beyond. Column and 2D box experiments were performed at two scales to determine the maximum clean gap which could be jumped vertically and horizontally. Once the maximum gap had been determined, sensitivity to various in situ and engineering control parameters were explored including: coal tar layer thickness, soil permeability, moisture content, NAPL saturation, and air injection flowrate. High resolution thermocouples informed the progress of the reaction, continuous gas emissions analysis revealed when the reaction was active and dormant, and detailed excavation mapped the extent of remediation and whether gaps were successfully jumped. The work demonstrated that substantial clean gaps, approaching the limit of the laboratory scale, can be jumped by the smouldering reaction using convective heat transfer. Also observed in some cases was the mobilization of pre-heated coal tar into the clean gaps and the reaction's ability to propagate through and destroy coal tar both adjacent to and within the gaps. This work is providing new insights into the robust nature of the technology for in situ applications, and indicating how extreme the heterogeneity has to be before the reaction is interrupted and a new ignition location would be required.

  16. Importance of heterocylic aromatic compounds in monitored natural attenuation for coal tar contaminated aquifers: A review

    NASA Astrophysics Data System (ADS)

    Blum, Philipp; Sagner, Anne; Tiehm, Andreas; Martus, Peter; Wendel, Thomas; Grathwohl, Peter

    2011-11-01

    NSO heterocycles (HET) are typical constituents of coal tars. However, HET are not yet routinely monitored, although HET are relatively toxic coal tar constituents. The main objectives of the study is therefore to review previous studies and to analyse HET at coal tar polluted sites in order to assess the relevance of HET as part of monitored natural attenuation (MNA) or any other long-term monitoring programme. Hence, natural attenuation of typical HET (indole, quinoline, carbazole, acridine, methylquinolines, thiophene, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, methylbenzofurans, dimethylbenzofurans and xanthene) were studied at three different field sites in Germany. Compound-specific plume lengths were determined for all main contaminant groups (BTEX, PAH and HET). The results show that the observed plume lengths are site-specific and are above 250 m, but less than 1000 m. The latter, i.e. the upper limit, however mainly depends on the level of investigation, the considered compound, the lowest measured concentration and/or the achieved compound-specific detection limit and therefore cannot be unequivocally defined. All downstream contaminant plumes exhibited HET concentrations above typical PAH concentrations indicating that some HET are generally persistent towards biodegradation compared to other coal tar constituents, which results in comparatively increased field-derived half-lives of HET. Additionally, this study provides a review on physicochemical and toxicological parameters of HET. For three well investigated sites in Germany, the biodegradation of HET is quantified using the centre line method (CLM) for the evaluation of bulk attenuation rate constants. The results of the present and previous studies suggest that implementation of a comprehensive monitoring programme for heterocyclic aromatic compounds is relevant at sites, if MNA is considered in risk assessment and for remediation.

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

    NASA Astrophysics Data System (ADS)

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

    2000-11-01

    The mobility of the most water-soluble polynuclear aromatic hydrocarbons (PAHs) such as naphthalene in contaminated soils from manufactured gas plant (MGP) sites or other similar sites is influenced not only by the naturally occurring soil organic matter (SOM) but also, and in many cases mostly, by the nature and concentration of coal tar xenobiotic organic matter (XOM) and other PAH molecules present in the medium under various physical states. The objective of the present study was to quantify the effects of these factors using batch experiments, in order to simulate naphthalene transport in soil-tar-water systems using column experiments. Naphthalene sorption was studied in the presence of (i) solid coal tar particles, (ii) phenanthrene supplied as pure crystals, in the aqueous solution or already sorbed onto the soil, (iii) fluoranthene as pure crystals, and (iv) an aqueous solution of organic molecules extracted from a liquid tar. All experiments were conducted under abiotic conditions using short naphthalene/sorbent contact times of 24-60 h. Although these tests do not reflect true equilibrium conditions which usually take more time to establish, they were used to segregate relatively rapid sorption phenomena ("pseudo equilibrium") from slow sorption and other aging phenomena. For longer contact times, published data have shown that experimental biases due to progressive changes in the characteristics of the soil and the solution may drastically modify the affinity of the solutes for the soil. Slow diffusion in the microporosity and in dense organic phases may also become significant over the long term, along with some irreversible aging phenomena which have not been addressed in this work. Results showed that PAHs had no effect on naphthalene sorption when present in the aqueous solution or as pure crystals, due to their low solubility in water. Adsorbed phenanthrene was found to reduce naphthalene adsorption only when present at relatively high

  18. The effects of coal tar based pavement sealer on amphibian development and metamorphosis.

    PubMed

    Bryer, Pamela J; Elliott, Jan N; Willingham, Emily J

    2006-04-01

    Coal tar based pavement sealers are applied regularly to parking lots and contain significant levels of polycyclic aromatic hydrocarbons (PAHs). Recently a connection between elevated levels of PAHs in streams and storm water runoff from parking lots has been identified. We tested the hypothesis that coal tar based pavement sealers could alter the survival, growth, and development of amphibians using a model species, Xenopus laevis. Ten fertilized individuals were placed singly into containers containing one of four treatment groups: control, low, medium, and high (respective nominal concentrations 0, 3, 30, and 300 ppm TPAH). All of the individuals in the high exposure group died by the sixth day of exposure. By day 14 there were significant patterns of stunted growth (p<0.0001) and slower development (p=0.006) in the medium and high exposure groups relative to the control and low treatment groups. When the experiment ended on day 52 the control and low-dose individuals had achieved more advanced developmental stages than the medium group (p=0.0007). These data indicate that these commonly used coal tar based pavement sealers may potentially affect the amphibian taxa living in areas that receive storm water runoff.

  19. Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement

    USGS Publications Warehouse

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10–4, as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10–5. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0–6 years of age).

  20. Mass transfer in stirred tank for phenolic extraction from coal tar

    NASA Astrophysics Data System (ADS)

    Fardhyanti, Dewi Selvia; Wibowo, Bahy; Rafiqi, Muhammad

    2017-01-01

    Coal production in Indonesia on 2014 reached 368.9 million tons. The used of coal utilization using pyrolysis process to produce coal tar is 15.8% by weight. Coal tar solution containing phenol as much as 8.06% (v / v) were extracted using a solvent of 80 % methanol. Time extraction is conducted for 30 minutes by making every 5 minutes. Samples are then separated to form two layers so that become layer of extract and raffinate. Extract and raffinate layer was then tested by using UV - Vis sektrofotometer so that the data obtained experimental results.The reserach about phenomenon and models of mass transfering and taking the phenol compound from coal tir is less. The result shows, the highest extracted of concentration phenol in 40°C, tank diameter 9cm, stirrer diameter 3,5cm, stirring speed of 250rpm and at 20 minutes extraction time got 2,35% concentration of phenol. Thus, the increasing temperature and stirred velocity will increase phenol concentration. In other hand, decreasing tank diameter will increase phenol concentration.

  1. Oil shale, tar sand, coal research, advanced exploratory process technology jointly sponsored research

    SciTech Connect

    Not Available

    1992-01-01

    Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced recovery techniques; and menu driven access to the WDEQ Hydrologic Data Management Systems.

  2. Mass Transfer Coefficientin Stirred Tank for p-Cresol Extraction Process from Coal Tar

    NASA Astrophysics Data System (ADS)

    Fardhyanti, D. S.; Tyaningsih, D. S.; Afifah, S. N.

    2017-04-01

    Indonesia is a country that has a lot of coal resources. The Indonesian coal has a low caloric value. Pyrolysis is one of the process to increase the caloric value. One of the by-product of the pyrolysis process is coal tar. It contains a lot of aliphatic or aromatic compounds such asp-cresol (11% v/v). It is widely used as a disinfectant. Extractionof p-Cresol increases the economic value of waste of coal. The aim of this research isto study about mass tranfer coefficient in the baffled stirred tank for p-Cresolextraction from coal tar. Mass transfer coefficient is useful for design and scale up of industrial equipment. Extraction is conducted inthe baffled stirred tank equipped with a four-bladed axial impeller placed vertically in the vessel. Sample for each time processing (5, 10, 15, 20, 25 and 30minutes) was poured into a separating funnel, settled for an hour and separated into two phases. Then the two phases were weighed. The extract phases and raffinate phases were analyzed by Spectronic UV-Vis. The result showed that mixing speed of p-Cresol extraction increasesthe yield of p-Cresol and the mass transfer coefficient. The highest yield of p-Cresol is 49.32% and the highest mass transfer coefficient is 4.757 x 10-6kg/m2s.

  3. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research

    SciTech Connect

    Speight, J.G.

    1992-01-01

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  4. Determination of the forms of nitrogen released in coal tar during rapid devolatilization

    SciTech Connect

    Fletcher, T.H.

    1996-10-31

    The primary objective of this work is determined the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (10{sup 4} to 10{sup 5} K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. the forms of nitrogen in coal, char, and tar samples will be analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques will be preformed in collaboration with other research at BYU, the University of Utah, and industrial organizations. Coals will be obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HiPPS (high Performance Power Systems) and LEBS (Low-Emission Boiler Systems) program. Anticipated results from the proposed research will be (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HiPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  5. DETERMINATION OF THE FORMS OF NITROGEN RELEASED IN COAL TAR DURING RAPID DEVOLATILIZATION

    SciTech Connect

    1998-10-30

    The primary objective of this work is to determine the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (10 4 to 10 5 K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. The forms of nitrogen in coal, char, and tar samples are analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-Ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques are being performed in collaboration with other researchers at BYU, the University of Utah, and industrial organizations. Coals have been obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HiPPS (High Performance Power Systems) and LEBS (Low-Emission Boiler Systems) programs. Results from the proposed research are (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HiPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  6. Carcinogenic effects in A/J mice of particulate of a coal tar paint used in potable water systems.

    PubMed

    Robinson, M; Laurie, R D; Bull, R J; Stober, J A

    1987-01-01

    Coal tar paints are among the products used as inside coatings for water pipes and storage tanks to retard corrosion in potable water supply systems. Four different formulations of these paints were tested in earlier work by this laboratory in the Ames mutagenesis and the mouse skin carcinogenesis bioassays. The paint most active in these assays were then tested in a particulate form in the lung adenoma assay with A/J mice. The paint was applied to clean glass plates, cured, collected and homogenized in 2% Emulphor. Doses of this coal tar suspension were administered by gavage at 1.0, 10.0 and 55.0 mg in 0.2 ml per mouse 3X weekly for 8 weeks. The total doses of coal tar paint were 24, 240, and 1320 mg/mouse. Benzo[a]pyrene (BaP), administered in a parallel schedule to a total dose of 6 mg/mouse, served as positive control. A negative control group received an equivalent volume of 2% Emulphor. Animals were killed at 9 months of age (8 months after first dose) and lung adenomas counted. A dose-related response, in the average number of lung tumors per mouse, was observed with the coal tar particulate. There were also squamous cell tumors of the forestomach in 42% of the mice receiving 55.0 mg coal tar paint per application.

  7. Tar yields from low-temperature carbonization of coal facies from the Powder River Basin, Wyoming, USA

    USGS Publications Warehouse

    Stanton, R.W.; Warwick, P.D.; Swanson, S.M.

    2005-01-01

    Tar yields from low-temperature carbonization correlate with the amount of crypto-eugelinite in samples selected to represent petrographically distinct coal facies of the Wyodak-Anderson coal zone. Tar yields from Fischer Assay range from <1 to 11 wt.% on a dry basis and correspond (r = 0.72) to crypto-eugelinite contents of the coal that range from 15 to 60 vol.%. Core and highwall samples were obtained from active surface mines in the Gillette field, Powder River Basin, Wyoming. Because the rank of the samples is essentially the same, differences in low-temperature carbonization yields are interpreted from compositional differences, particularly the crypto-eugelinite content. In the Wyodak-Anderson coal zone, crypto-eugelinite probably was derived from degraded humic matter which absorbed decomposition products from algae, fungi, bacteria, and liptinitic plant parts (materials possibly high in hydrogen). Previous modeling of the distribution of crypto-eugelinite in the discontinuous Wyodak-Anderson coal zone indicated that tar yields should be greater from coal composing the upper part and interior areas than from coal composing the lower parts and margins of the individual coal bodies. It is possible that hydrocarbon yields from natural coalification processes would be similar to yields obtained from laboratory pyrolysis. If so, the amount of crypto-eugelinite may also be an important characteristic when evaluating coal as source rock for migrated hydrocarbons.

  8. Implications of Use of Coal-Tar-Based Pavement Sealcoat on Urban Water Quality

    NASA Astrophysics Data System (ADS)

    Van Metre, P. C.

    2015-12-01

    Coal-tar-based (CT) sealcoat is used to protect and improve the appearance of asphalt pavement of driveways and parking lots primarily in the central and eastern U.S. and in Canada. CT sealcoat typically is 20 to 35% crude coal tar or coal-tar pitch and contains from 50,000 to 100,000 mg/kg polycyclic aromatic hydrocarbons (PAH), about 1,000 times more than asphalt-based (AS) sealcoat or asphalt itself. Tires and snowplows abrade the friable sealcoat surface into fine particles—median total PAH concentrations in dust from CT-sealcoated pavement are 2,200 mg/kg compared to a median concentration of 11 mg/kg for dust from unsealed pavement. Use of CT sealcoat has several implications for urban streams and lakes. Source apportionment modeling has indicated that, in regions where CT sealcoat is prevalent, particles from sealcoated pavement are contributing the majority of the PAHs to recently deposited lake sediment, often resulting in sediment concentrations above toxicity thresholds based on effects-based sediment quality guidelines. Acute 2-day laboratory toxicity testing of simulated runoff from CT-sealcoated pavement to a cladoceran (Ceriodaphnia dubia) and fathead minnows (Pimephales promelas) demonstrated that toxicity continues for samples collected for weeks or months following sealcoat application and that toxicity is enhanced by exposure to UV light. Using the fish-liver cell line RTL-W1, runoff collected as much as 36 days following CT-sealcoat application has been demonstrated to cause DNA damage and impair DNA repair capacity. These results demonstrate that CT runoff is a potential hazard to aquatic ecosystems and that exposure to sunlight can enhance toxicity and genetic damage. Recent research has provided direct evidence that restricting use of CT sealcoat in a watershed can lead to a substantial reduction in PAH concentrations in receiving water bodies.

  9. Prostaglandin precursors in plasma phospholipids of patients with psoriasis: effects of treatment with coal tar.

    PubMed

    Strong, A M; Horrobin, D F; Manku, M S; Huang, Y S

    1984-05-01

    Plasma phospholipids of patients with psoriasis have significantly reduced levels of dihomogammalinolenic acid (20:3n-6), arachidonic acid (20:4n-6) and adrenic acid (22:4n-6), the precursors of the 1, 2 and homo-2 series of prostaglandins (PGs). Concentrations of the 3 series PG precursor, eicosapentaenoic acid (20:5n-3) were normal. Hospital treatment with a coal tar regime produced a rise in 20:3n-6 to levels which were significantly above normal.

  10. PAH volatilization following application of coal-tar-based pavement sealant

    USGS Publications Warehouse

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  11. A study on the effect of heat treatment temperature on mesophase development in coal tar pitch

    NASA Astrophysics Data System (ADS)

    Soni, Neha; Shah, Raviraj K.; Shrivastava, Rakesh; Datar, Manoj

    2013-06-01

    In the present study, a zero quinoline insoluble (QI) isotropic coal tar pitch was taken for the preparation of mesophase pitch. The pitch was heated in inert atmosphere at different heat treatment temperatures keeping same heating rate and soaking time to study the formation, growth and coalescence of mesophase spheres in the pitch. Such pitches were characterized for insoluble content (QI & TI), mesophase content, sulphur content, weight loss in inert atmosphere, softening point, coking value (CVC), C/H ratio etc. Results show that the insoluble content (QI & TI) and mesophase content of pitch increase with increase of heat treatment temperature.

  12. Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report

    SciTech Connect

    Prausnitz, J.M.

    1980-05-01

    This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

  13. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    SciTech Connect

    Boyer, N.W.; Taylor, R.S.

    1980-10-28

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  14. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    DOEpatents

    Taylor, Robert S.; Boyer, Norman W.

    1980-01-01

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of Borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% Borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  15. Isolation of a highly mutagenic aminophenanthrene from a coal gasification process tar.

    PubMed

    Haugen, D A; Stamoudis, V C; Peak, M J; Boparai, A S

    1986-02-01

    A major portion of the mutagenic activity associated with products and by-products of coal conversion can be ascribed to nitrogen-containing bases. We improved the extraction efficiencies for three- to five-ring aromatic bases by extracting them with a mixture of methanol and aqueous HCl, rather than with aqueous HCl alone. A complex mutagenic basic fraction of a coal gasification process tar was successively fractionated using cation exchange and reversed phase high-performance liquid chromatography. The fractions were assayed for mutagenic activity and were chemically analyzed by gas chromatography and gas chromatography-mass spectrometry. Aminophenanthrenes were identified as major contributors to the mutagenicity of the basic fraction. Aminonaphthalenes, aminobiphenyls, and their alkyl homologs were also present but were not detected as principal mutagens.

  16. Severe Coal Tar Sealcoat Runoff Toxicity to Fish Is Prevented by Bioretention Filtration.

    PubMed

    McIntyre, Jenifer K; Edmunds, Richard C; Anulacion, Bernadita F; Davis, Jay W; Incardona, John P; Stark, John D; Scholz, Nathaniel L

    2016-02-02

    Coal tar sealcoats applied to asphalt surfaces in North America, east of the Continental Divide, are enriched in petroleum-derived compounds, including polycyclic aromatic hydrocarbons (PAHs). The release of PAHs and other chemicals from sealcoat has the potential to contaminate nearby water bodies, reducing the resiliency of aquatic communities. Despite this, relatively little is known about the aquatic toxicology of sealcoat-derived contaminants. We assessed the impacts of stormwater runoff from sealcoated asphalt on juvenile coho salmon (Oncorhynchus kisutch) and embryo-larval zebrafish (Danio rerio). We furthermore evaluated the effectiveness of bioretention as a green stormwater method to remove PAHs and reduce lethal and sublethal toxicity in both species. We applied a coal tar sealcoat to conventional asphalt and collected runoff from simulated rainfall events up to 7 months postapplication. Whereas sealcoat runoff was more acutely lethal to salmon, a spectrum of cardiovascular abnormalities was consistently evident in early life stage zebrafish. Soil bioretention effectively reduced PAH concentrations by an order of magnitude, prevented mortality in juvenile salmon, and significantly reduced cardiotoxicity in zebrafish. Our findings show that inexpensive bioretention methods can markedly improve stormwater quality and protect fish health.

  17. Microporous Organic Polymers Based on Hyper-Crosslinked Coal Tar: Preparation and Application for Gas Adsorption.

    PubMed

    Gao, Hui; Ding, Lei; Bai, Hua; Li, Lei

    2017-02-08

    Hyper-crosslinked polymers (HCPs) are promising materials for gas capture and storage, but high cost and complicated preparation limit their practical application. In this paper, a new type of HCPs (CTHPs) was synthesized through a one-step mild Friedel-Crafts reaction with low-cost coal tar as the starting material. Chloroform was utilized as both solvent and crosslinker to generate a three-dimensional crosslinked network with abundant micropores. The maximum BET surface area of the prepared CTHPs could reach up to 929 m(2)  g(-1) . Owing to the high affinity between the heteroatoms on the coal-tar building blocks and the CO2 molecules, the adsorption capacity of CTHPs towards CO2 reached up to 14.2 wt % (1.0 bar, 273 K) with a high selectivity (CO2 /N2 =32.3). Furthermore, the obtained CTHPs could adsorb 1.27 wt % H2 at 1.0 bar and 77.3 K, and also showed capacity for the capture of high organic vapors at room temperature. In comparison with other reported porous organic polymers, CTHPs have the advantages of low-cost, easy preparation, and high gas-adsorption performance, making them suitable for mass production and practical use in the future.

  18. Coal-tar-based parking lot sealcoat: an unrecognized source of PAH to settled house dust.

    PubMed

    Mahler, Barbara J; Metre, Peter C Van; Wilson, Jennifer T; Musgrove, Marylynn; Burbank, Teresa L; Ennis, Thomas E; Bashara, Thomas J

    2010-02-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 microg/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 microg/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 microg/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 microg/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant.

  19. Smoldering Remediation of Coal-Tar-Contaminated Soil: Pilot Field Tests of STAR.

    PubMed

    Scholes, Grant C; Gerhard, Jason I; Grant, Gavin P; Major, David W; Vidumsky, John E; Switzer, Christine; Torero, Jose L

    2015-12-15

    Self-sustaining treatment for active remediation (STAR) is an emerging, smoldering-based technology for nonaqueous-phase liquid (NAPL) remediation. This work presents the first in situ field evaluation of STAR. Pilot field tests were performed at 3.0 m (shallow test) and 7.9 m (deep test) below ground surface within distinct lithological units contaminated with coal tar at a former industrial facility. Self-sustained smoldering (i.e., after the in-well ignition heater was terminated) was demonstrated below the water table for the first time. The outward propagation of a NAPL smoldering front was mapped, and the NAPL destruction rate was quantified in real time. A total of 3700 kg of coal tar over 12 days in the shallow test and 860 kg over 11 days in the deep test was destroyed; less than 2% of total mass removed was volatilized. Self-sustaining propagation was relatively uniform radially outward in the deep test, achieving a radius of influence of 3.7 m; strong permeability contrasts and installed barriers influenced the front propagation geometry in the shallow test. Reductions in soil hydrocarbon concentrations of 99.3% and 97.3% were achieved in the shallow and deep tests, respectively. Overall, this provides the first field evaluation of STAR and demonstrates that it is effective in situ and under a variety of conditions and provides the information necessary for designing the full-scale site treatment.

  20. Coal-Tar-Based Parking Lot Sealcoat: An Unrecognized Source of PAH to Settled House Dust

    PubMed Central

    2010-01-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 μg/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 μg/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 μg/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 μg/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. PMID:20063893

  1. Coal-tar-based sealcoated pavement: a major PAH source to urban stream sediments.

    PubMed

    Witter, Amy E; Nguyen, Minh H; Baidar, Sunil; Sak, Peter B

    2014-02-01

    We used land-use analysis, PAH concentrations and assemblages, and multivariate statistics to identify sediment PAH sources in a small (~1303 km(2)) urbanizing watershed located in South-Central, Pennsylvania, USA. A geographic information system (GIS) was employed to quantify land-use features that may serve as PAH sources. Urban PAH concentrations were three times higher than rural levels, and were significantly and highly correlated with combined residential/commercial/industrial land use. Principal components analysis (PCA) was used to group sediments with similar PAH assemblages, and correlation analysis compared PAH sediment assemblages to common PAH sources. The strongest correlations were observed between rural sediments (n = 7) and coke-oven emissions sources (r = 0.69-0.78, n = 5), and between urban sediments (n = 22) and coal-tar-based sealcoat dust (r = 0.94, n = 47) suggesting that coal-tar-based sealcoat is an important urban PAH source in this watershed linked to residential and commercial/industrial land use.

  2. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research

    SciTech Connect

    Not Available

    1992-01-01

    Progress made in five research programs is described. The subtasks in oil shale study include oil shale process studies and unconventional applications and markets for western oil shale.The tar sand study is on recycle oil pyrolysis and extraction (ROPE) process. Four tasks are described in coal research: underground coal gasification; coal combustion; integrated coal processing concepts; and sold waste management. Advanced exploratory process technology includes: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research covers: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; shallow oil production using horizontal wells with enhanced oil recovery techniques; NMR analysis of sample from the ocean drilling program; and menu driven access to the WDEQ hydrologic data management system.

  3. Evolution of dissolved organic matter during abiotic oxidation of coal tar--comparison with contaminated soils under natural attenuation.

    PubMed

    Hanser, Ogier; Biache, Coralie; Boulangé, Marine; Parant, Stéphane; Lorgeoux, Catherine; Billet, David; Michels, Raymond; Faure, Pierre

    2015-01-01

    In former coal transformation plants (coking and gas ones), the major organic contamination of soils is coal tar, mainly composed of polycyclic aromatic compounds (PACs). Air oxidation of a fresh coal tar was chosen to simulate the abiotic natural attenuation impact on PAC-contaminated soils. Water-leaching experiments were subsequently performed on fresh and oxidized coal tars to study the influence of oxidation on dissolved organic matter (DOM) quality and quantity. The characterization of the DOM was performed using a combination of molecular and spectroscopic techniques (high-performance liquid chromatography-size-exclusion chromatography (HPLC-SEC), 3D fluorescence, and gas chromatography coupled with mass spectrometry (GC-MS)) and compared with the DOM from contaminated soils sampled on the field exposed to natural attenuation for several decades. An increase in the oxygenated polycyclic aromatic compound concentrations was observed with abiotic oxidation both in the coal tar and the associated DOM. Polycyclic aromatic hydrocarbon concentrations in the leachates exceeded pure water solubility limits, suggesting that co-solvation with other soluble organic compounds occurred. Furthermore, emission excitation matrix analysis combined with synchronous fluorescence spectra interpretation and size-exclusion chromatography suggests that oxidation induced condensation reactions which were responsible for the formation of higher-molecular weight compounds and potentially mobilized by water. Thus, the current composition of the DOM in aged soils may at least partly result from (1) a depletion in lower-molecular weight compounds of the initial contamination stock and (2) an oxidative condensation leading to the formation of a higher-molecular weight fraction. Abiotic oxidation and water leaching may therefore be a significant combination contributing to the evolution of coal tar-contaminated soils under natural attenuation.

  4. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 January 1996--31 March 1996

    SciTech Connect

    Suuberg, E.M.

    1996-09-01

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do not lend themselves well for application to very complex, poorly characterized coal tars. The methods based upon more global types of characterizations have not yet dealt much with the question of oxygenated functional groups. In short, only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well- established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. A significant amount of time has been devoted during this quarter to developing techniques for measurements of vapor pressures of coal tar related compounds, and mixtures, in a ``continuous`` mode, using the effusion technique.

  5. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management

    USGS Publications Warehouse

    Mahler, Barbara J.; Van Metre, Peter C.; Crane, Judy L.; Watts, Alison W.; Scoggins, Mateo; Williams, E. Spencer

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  6. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management.

    PubMed

    Mahler, Barbara J; Metre, Peter C Van; Crane, Judy L; Watts, Alison W; Scoggins, Mateo; Williams, E Spencer

    2012-03-20

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments-including stormwater runoff, lake sediment, soil, house dust, and most recently, air-contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  7. Effect of addition of coal-tar pitches on adhesive properties of copolymer of ethylene with vinyl acetate

    SciTech Connect

    Chernikov, O.I.; Mironov, V.A.; Mitrokhina, L.L.; Kuznetsova, L.S.; Nepomnyashchaya, A.S.; Kachan, A.A.

    1984-08-01

    Results of studies of the effect of the addition of coal-tar pitches on the water resistance and adhesive properties of the copolymer of ethylene with vinyl acetate (CEVA) used as an adhesive layer in polymer films for protection of oil and gas pipelines against corrosion are presented. The dependence of the adhesive strength of CEVA with 12% vinyl acetate (VA) on the concentration of coal-tar pitch additives with softening temperatures of 70, 85, and 107/sup 0/C was found to be extreme with maximum adhesive strength in the concentration range of 0.8-1.4%. This increase in adhesive strength at low concentrations is thought to be due to improvement in the wetability of the melt. After long exposure (30h) to boiling water, the water resistance of the adhesive joints was improved by the addition of coal-tar pitches; but in the initial period of boiling, a decrease in water resistance was produced by the addition of coal-tar pitches. Films with pitch additives with a softening temperature of 70/sup 0/C were noted to have the highest hydrophobicity at low concentrations of the pitch additive.

  8. Mass transfer and biodegradation of PAH compounds from coal tar. Quarterly technical report, January--March 1993

    SciTech Connect

    Ramaswami, A.; Ghoshal, S.; Luthy, R.G.

    1994-09-01

    This study examines the role of physico-chemical mass transfer processes on the rate of biotransformation of polycyclic aromatic hydrocarbon (PAH) compounds released from non-aqueous phase liquid (NAPL) coal tar present at residual saturation within a microporous medium. A simplified coupled dissolution-degradation model is developed that describes the concurrent mass transfer and biokinetic processes occurring in the system. Model results indicate that a dimensionless Damkohler number can be utilized to distinguish between systems that are mass transfer limited, and those that are limited by biological phenomena. The Damkohler number is estimated from independent laboratory experiments that measure the rates of aqueous phase dissolution and biodegradation of naphthalene from coal tar. Experimental data for Stroudsburg coal tar imbibed within 236 {mu}m diameter silica particles yield Damkohler numbers smaller than unity, indicating, for the particular system under study, that the overall rate of biotransformation of naphthalene is not limited by the mass transfer of naphthalene from coal tar to the bulk aqueous phase. There is a need for investigation of mass transfer for larger particles and/or other PAH compounds, and study of microbial rate-limiting phenomena including toxicity, inhibition and competitive substrate utilization.

  9. Coal-Tar-Based Pavement Sealcoat and PAHs: Implications for the Environment, Human Health, and Stormwater Management

    PubMed Central

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20−35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them. PMID:22296333

  10. You're standing on it! Coal-tar-based pavement sealcoat and environmental and human health

    USGS Publications Warehouse

    Mahler, Barbara J.; Van Metre, Peter C.

    2013-01-01

    Results from a new study by researchers from Baylor University and the USGS indicate that living adjacent to a coal-tar-sealed pavement is associated with significant increases in estimated excess lifetime cancer risk, and that much of the increased risk occurs during early childhood.

  11. Mass transfer and biodegradation of PAH compounds from coal tar. Quarterly technical report, April--June 1993

    SciTech Connect

    Ramaswami, A.; Ghoshal, S.; Luthy, R.G.

    1994-09-01

    This study, examines the role of physico-chemical mass transfer processes on the rate of biotransformation of polycyclic aromatic hydrocarbon (PAH) compounds released from non-aqueous phase liquid (NAPL) coal tar present at residual saturation within a microporous medium. A simplified coupled dissolution-degradation model is developed that describes the concurrent mass transfer and biokinetic processes occurring in the system. Model results indicate that a dimensionless Damkohler number can be utilized to distinguish between systems that are mass transfer limited, and those that are limited by biological phenomena. The Damkohler number is estimated from independent laboratory experiments that measure the rates of aqueous phase dissolution and biodegradation of naphthalene from coal tar. Experimental data for Stroudsburg coal tar imbibed within 236 {mu}m diameter silica particles yield Damkohler numbers smaller than unity, indicating, for the particular system under study, that the overall rate of biotransformation of naphthalene is not limited by the mass transfer of naphthalene from coal tar to the bulk aqueous phase. There is a need for investigation of mass transfer for larger particles and/or other PAH compounds, and study, of microbial rate-limiting phenomena including toxicity, inhibition and competitive substrate utilization.

  12. Catalytic pyrolysis of coal tar and the dynamics of gases sorbed in polymers probed by NMR

    SciTech Connect

    Cain, E.J.

    1989-01-01

    The pyrolysis of a bituminous coal tar in a fixed bed reactor, was investigated. Potential catalysts and the effect of temperature and residence time on tar conversion was also investigated. The observed temperature dependence of tar conversion was then used to model the kinetics of these reactions by applying a lumped parameter approach. The strongest catalytic activity was displayed by large pore synthetic zeolites while both synthetic and naturally occurring small pore zeolites were much less effective. The mineral clays, kaolinite and montmorillonite and the diatomaceous earth, kieselguhr, were similar to the small pore zeolites in their activity. In part two, the spin relaxation of {sup 13}CO{sub 2} sorbed in poly(dimethyl siloxane), PDMS; polyisobutylene, PIB; and bisphenol-A polycarbonate, BPA-PC, and of {sup 129}Xe sorbed in BPA-PC were investigated. Spin-lattice, T{sub 1}, and spin-spin, T{sub 2}, relaxation times and the nuclear Overhauser enhancements, NOE, were determined as a function of temperature and static magnetic field strength. For CO{sub 2} in both PDMS and BPA-PC, short T{sub 2}'s and low NOE values relative to that predicted by the correlation time associated with the T{sub 1}'s were observed. This is interpreted in terms of a distribution of motional states and, for CO{sub 2} sorbed in BPA-PC, we test a special case distribution, a dual mode model, wherein two distinct species, each with its own set of correlation times are assumed. For {sup 129}Xe in BPA-PC, the less than expected NOE suggests either a distribution of correlation times or relaxation arising out of an induced chemical shift.

  13. Meta-analysis of lung cancer in asphalt roofing and paving workers with external adjustment for confounding by coal tar

    SciTech Connect

    Fayerweather, W.E.

    2007-07-01

    The study's objectives were to update Partanen's and Boffetta's 1994 meta-analysis of lung cancer among roofing and paving asphalt workers and explore the role of coal tar in explaining the statistical heterogeneity among these studies. Information retrieval strategies and eligibility criteria were defined for identifying the epidemiologic studies to be included in the analysis. The relative risk ratio (RR) for lung cancer was selected as the effect measure of interest. Coal tar bias factors were developed and used to externally adjust each eligible study's published RR for confounding by coal tar. The meta-Relative Risk (meta-RR) and its variance were estimated by general variance-based methods. Heterogeneity of the RRs was assessed by heterogeneity chi-square and I{sup 2} tests. The results from this update were similar to those in Partanen's and Boffetta's original meta-analysis. Although the meta-RRs for the roofers and the pavers were no longer statistically significantly different from one another, significant heterogeneity remained within each of the coal tar-adjusted sectors. Meta-analysis of non-experimental epidemiologic studies is subject to significant uncertainties as is externally correcting studies for confounding. Given these uncertainties, the specific quantitative estimates in this (or any similar) analysis must be viewed with caution. Nevertheless, this analysis provides support for the hypothesis proposed by several major reviewers that confounding by coal tar-related PAH exposures may explain most or all of the lung cancer risks found in the epidemiologic literature on asphalt roofing and paving workers.

  14. Comparative carcinogenic and mutagenic activity of coal tar and petroleum asphalt paints used in potable water supply systems.

    PubMed

    Robinson, M; Bull, R J; Munch, J; Meier, J

    1984-02-01

    Coal tar and petroleum asphalt paints are among the products used as coatings for water pipes and storage tanks to retard corrosion. Formulations of these coatings were tested in the Ames mutagenesis and the mouse skin carcinogenesis bioassays. To test the mutagenicity of the paints, six doses ranging from 0.005 to 10 microliters per plate were assayed. In the mouse skin bioassay, doses of the coal tar paints ranging from 0.2 to 200 microliters were administered topically to 30 SENCAR mice per group. These initiating doses were followed by applications of 1.0 micrograms of 12-o-tetradecanoyl-phorbol-13-acetate (TPA) in 0.2 ml acetone topically, three times weekly for 20 weeks. Petroleum asphalt paints were tested in groups of 40 animals at 200 and 600 microliters doses. All coal tar paints showed mutagenic activity after metabolic activation with S-9, with the highest response being in strains TA 98 and TA 100. None of the petroleum asphalt paints gave mutagenic responses. Both types of coatings resulted in positive responses in the initiation/promotion study. The coal tar paints gave rise to 1000-1800 times the tumor response observed with petroleum asphalt products. One coal tar product was positive when tested as a complete carcinogen in the mouse at 2 microliters per application once weekly for 30 weeks, whereas the asphalt paint was negative at 100 times the dose. The biological responses to the products were greater than expected from their polycyclic aromatic hydrocarbon (PAH) content. These findings suggest that the hazard posed by these coatings may not be fully explained by their PAH contents.

  15. Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system

    USGS Publications Warehouse

    Rostad, C.E.; Pereira, W.E.; Hult, M.F.

    1985-01-01

    Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or mutagens. Groundwater contamination by these toxic compounds may pose an environmental health hazard in nearby public water-supply wells. Fluid samples from this aquifer developed two phases upon settling: an upper aqueous phase, and a lower oily-tar phase. After separating the phases, polycyclic aromatic compounds in each phase were isolated using complexation with N-methyl-2-pyrrolidone and identified by fused-silica capillary gas chromatography/mass spectrometry. Thirty-one of the polycyclic aromatic compounds were chosen for further study from four different classes: 12 polycyclic aromatic hydrocarbons, 10 nitrogen heterocycles, 5 sulfur heterocycles, and 4 oxygen heterocycles. Within each compound class, the tar/water partition coefficients of these compounds were reasonably comparable with the respective n-octanol/water partition coefficient.

  16. Kinetic study of the catalytic carbonization of coal tar pitch-petroleum coke mixtures

    SciTech Connect

    Xue, J.; Oeye, H.A.; Soerlie, M.

    1996-10-01

    The rate of carbonization has important impacts on the energy consumption and the productivity in baking process of reduction anodes. In the present work the carbonization of coal tar pitch-petroleum coke mixtures with catalysts, such as S, AlCl{sub 3}, AlF{sub 3}, and Fe{sub 2}Cp{sub 2}(CO){sub 4}, was investigated by thermogravimetry (TG) and kinetic analysis of the data. It was found that the pyrolysis temperature for non-coking volatiles decreased with catalysts, and that the coke yield of pitch binder increased. Almost all the sulfur and most of the iron from the additives can be removed during heat treatment, while the remaining aluminum in the residues may not be harmful.

  17. Porous carbon nanosheets from coal tar for high-performance supercapacitors

    NASA Astrophysics Data System (ADS)

    He, Xiaojun; Ma, Hao; Wang, Jingxian; Xie, Yuanyang; Xiao, Nan; Qiu, Jieshan

    2017-07-01

    A hydroxide-template strategy coupled with in-situ chemical activation is reported for the first time to fabricate porous carbon nanosheets (PCNSs) from coal tar. The thin PCNSs feature abundant short pores accessible for fast ion transport and high specific surface area up to 3235 m2 g-1 for ion adsorption. As electrodes for supercapacitors, the PCNSs show a high capacitance of 296.2 F g-1 at 0.05 A g-1 in 6 M KOH electrolyte, an excellent rate performance with a capacitance of 220.7 F g-1 at 20 A g-1 and a superior cycle stability with over 97.2% capacitance retention after 11000 charge-discharge cycles at 3.5 A g-1. This work paves a new way for efficient fabrication of sheet-like carbon materials with tuned porous structure from polycyclic aromatic hydrocarbons for high performance supercapacitors.

  18. Study of the composition of tars produced from blends of coal and polyethylene wastes using high-performance liquid chromatography.

    PubMed

    Díez, M A; Alvarez, R; Gayo, F; Barriocanal, C; Moinelo, S R

    2002-02-01

    Tars produced at semi-industrial scale in a coke oven of 6 x 10(3) kg capacity were used to investigate the effect of using polyethylene waste as an additive in the carbonization process with coal. The polyethylene wastes used were low-density polyethylene from the agriculture greenhouses and high-density polyethylene from domestic sources. The high-performance liquid chromatography analysis of the soluble fractions in toluene and carbon disulfide, using two polystyrene-divinylbenzene columns and a mixture of dichloromethane-methanol as a mobile phase, provides useful information on the composition of tars and their derived pitches in terms of the substitution and molecular topology of polynuclear aromatic compounds (PACs). Differences in composition of tars produced with polyethylene waste at 1% (w/w) have been found to be negligible, while a higher amount of the waste (3%, w/w) promoted the formation of peri-condensed PACs at the expense of the substituted cata-condensed PACs. This behaviour is due to more extensive secondary reactions of tar precursors via dealkylation and aromatic condensation taking place during the carbonization process as a consequence of a more viscous co-carbonizing system. Changes in tar composition caused by this amount of polyethylene waste addition were comparable to those promoted by an increase in the carbonization temperature at semi-industrial and industrial ovens and by the coal preheating before the carbonization process. The characteristic features in tar composition were also found for the derived pitches from tars obtained with the polyethylene waste addition.

  19. Natural selection of PAH-degrading bacterial guilds at coal-tar disposal sites

    SciTech Connect

    Ghiorse, W.C.; Herrick, J.B.; Sandoli, R.L.; Madsen, E.L.

    1995-06-01

    Microbial activity patterns at buried coal-tar disposal sites have been under investigation for several years to determine the response of naturally occurring microflora to polycyclic aromatic hydrocarbons (PAHs) at the sites. At one site in upstate New York, data have shown enrichment of PAH-degrading bacteria in subsurface contaminated zones but not in uncontaminated zones. Similar work at a Midwestern site showed that the same trends existed in a heterogeneous disposal site except that a borehole outside the plume showed some PAH-mineralization activity. Polymerase chain reaction amplification of DNA extracted from sediment samples from the New York site indicated the presence of naphthalene metabolism genes nahAc and nahR, similar to those found on the NAH7 plasmid of Pseudomonas putida G7. Significant sequence polymorphism was observed in amplified nahAc products, indicating that divergent homologs of nahAc were present in the native community. Protozoan numbers were elevated in sediment samples displaying relatively high PAH-degrading activity, suggesting that a food chain was established based on PAH-degrading bacteria. Removal of the coal-tar source at the site occurred in 1991. In 1992, sampling of three key borehole stations revealed that mixing and backfilling operations had introduced soil microorganisms into the source area and introduced 14C-PAH-mineralization activity into the previously inactive pristine area. Thus removal of the source of the contaminants and restoration at the site have altered the microbial activity patterns outside the contaminant plume as well as in the source area. 15 refs., 3 figs.

  20. The nature and molecular basis of cutaneous photosensitivity reactions to psoralens and coal tar

    SciTech Connect

    Pathak, M.A.; Joshi, P.C.

    1983-06-01

    The basic aspects of cutaneous photosensitization reactions and the mode of therapeutic effectiveness of psoralens and coal tar, the two groups of photosensitizing agents used extensively in the photochemotherapy of psoriasis, have been reviewed. Psoralen-induced skin photosensitization and the therapeutic action of psoralens involve two distinct types of reactions, and these two reactions occur independently of each other and concurrently when the psoralen-treated skin (oral or topical) is exposed to 320 to 400 nm of radiation. The first, type I, is an oxygen-independent reaction and primarily involves photoreaction with DNA; the second, type II, is a sensitized reaction dependent on oxygen and involves the formation of singlet oxygen (1O2). The photoreactive form of psoralen is its triplet state, and the sites of reaction are (1) the cell membrane of the epidermal, dermal, and endothelial cells; (2) the cytoplasmic constituents, such as enzymes, RNA, lysosomes, etc.; (3) the cell nuclei (DNA and chromatin); and (4) the sensitized production of 1O2, which is responsible for cell-membrane damage and vasodilation. The major damage would be initiated by a type I reaction and would be seen in the form of nuclear damage to DNA resulting from the interaction of psoralen with DNA and to a lesser extent with RNA. The skin photosensitization response (erythema, edema, membrane damage, etc.) would result from a type II reaction involving the generation of 1O2. Crude coal tar (CCT), widely used in the Goeckerman therapy for psoriasis, also produces type I and type II reactions. The therapeutic and photosensitizing actions of CCT are due to (1) the photoconjugation of the photoreactive ingredients of CCT with DNA, causing interstrand cross-links; and (2) the production of 1O2. CCT is an efficient producer of 1O2, more so than 8-methoxypsoralen, and is responsible for cell-membrane damage and cellular edema.

  1. Pharmacological coal tar induces G:C to T:A transversion mutations in the skin of muta mouse.

    PubMed

    Vogel, U; Thein, N; Møller, P; Wallin, H

    2001-07-01

    Coal tar is a by-product of the distillation of coal. It consists of a complex chemical mixture of aromatic and aliphatic hydrocabons, with high concentrations of polycyclic aromatic hydrocarbons such as benzo[a]pyrene. We have previously shown that single painting on skin of mice increases the mutation frequency 16 times in murine epidermis cells (Thein et al. 2000). Here, we have determined the mutations by DNA sequencing. Coal tar was found to primarily induce G:C to T:A transversions and one-base pair deletions of G:C base pairs. More than half of the mutations were at CpG sites. The mutational spectrum is in agreement with that of benzo[a]pyrene and other polycyclic aromatic hydrocarbon mixtures.

  2. Environmental Forensics : Compound Specific Isotope Analysis Of PAHs. Study Of A Former Coal Tar Plant.

    NASA Astrophysics Data System (ADS)

    Assal, A.; Doherty, R.; Dickson, K.; Kalin, R. M.

    2008-12-01

    Stable carbon isotopic fingerprints of PAHs obtained by GC-IRMS have often been used in source apportionment studies. The use of PAHs in environmental forensics relies on the assumption that carbon isotopic fractionation caused by microbial degradation is less significant for these heavy molecular weight compounds than for lighter molecules such as chlorinated solvents or BTEX. Carbon isotopic fractionation of PAHs during degradation is still not well understood. The aim of this study was to assess the potential of CSIA of PAHs for environmental forensics applications at a complex (hydrogeology affected by tidal fluxes) former coal tar plant. In this work, soil samples from a tar works site were analyzed. The tar works operated on the site over a period of sixty years. A source apportionment study was first carried out based on 90 target PAHs quantified by GC-MS. These results were then compared to carbon isotope fingerprints. The separation of compounds of interest from co-extracted interfering peaks is a crucial prerequisite of CSIA by GC-IRMS. Hence, a sample preparation method which allowed the determination of precise carbon isotope signatures for up to 35 compounds per soil extract was developed, validated and applied to the samples previously analyzed by GC- MS. Although most soil samples were shown to be related to the point source tar contamination, PAHs ratios and principal component analysis of abundances highlighted some samples with unusual patterns, suggesting the input of a second source of contaminants. However, no statistically significant variation of the isotopic fingerprints of heavy molecular weight PAHs of these samples was observed. This was inconsistent with the first diagnosis. Since evidence was provided that most samples were only affected by a single source of contaminants, carbon isotopic fractionation was investigated in-situ. Importantly, naphthalene and 2- and 1- methylnaphthalenes isotopic fractionation was observed in a vertical

  3. Removal of phenol by powdered activated carbon prepared from coal gasification tar residue.

    PubMed

    Wang, Xiong-Lei; Shen, Jun; Niu, Yan-Xia; Wang, Yu-Gao; Liu, Gang; Sheng, Qing-Tao

    2017-04-10

    Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m(2)/g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater.

  4. Role of weathered coal tar pitch in the partitioning of polycyclic aromatic hydrocarbons in manufactured gas plant site sediments.

    PubMed

    Khalil, Muhammad F; Ghosh, Upal; Kreitinger, Joseph P

    2006-09-15

    Polycyclic aromatic hydrocarbons (PAHs) in manufactured gas plant (MGP) site sediments are often associated with carbonaceous particles that reduce contaminant bioavailability. Although black carbon inclusive partitioning models have been proposed to describe elevated PAH partitioning behavior, questions remain on the true loading and association of PAHs in different particle types in industrially impacted sediments. In the studied MGP sediments, the light density organic particles (coal, coke, wood, and coal tar pitch) comprised 10-20% of the total mass and 70-95% of the PAHs. The remainder of the PAHs in sediment was associated with the heavy density particles (i.e., sand, silt, and clays). Among the different particle types, coal tar pitch (quantified by a quinoline extraction method) contributed the most to the bulk sediment PAH concentration. Aqueous partition coefficients for PAHs measured using a weathered pitch sample from the field were generally an order of magnitude higher than reported for natural organic matter partitioning, and match well with theoretical predictions based on a coal tar-water partitioning model. A pitch-partitioning inclusive model is proposed that gives better estimates of the measured site-specific PAH aqueous equilibrium values than standard estimation based on natural organic matter partitioning only. Thus, for MGP impacted sediments containing weathered pitch particles, the partitioning behavior may be dominated by the sorption characteristics of pitch and not by natural organic matter or black carbon.

  5. Role of weathered coal tar pitch in the partitioning of polycyclic aromatic hydrocarbons in manufactured gas plant site sediments

    SciTech Connect

    Muhammad F. Khalil; Upal Ghosh; Joseph P. Kreitinger

    2006-09-15

    Polycyclic aromatic hydrocarbons (PAHs) in manufactured gas plant (MGP) site sediments are often associated with carbonaceous particles that reduce contaminant bioavailability. Although black carbon inclusive partitioning models have been proposed to describe elevated PAH partitioning behavior, questions remain on the true loading and association of PAHs in different particle types in industrially impacted sediments. In the studied MGP sediments, the light density organic particles (coal, coke, wood, and coal tar pitch) comprised 10-20% of the total mass and 70-95% of the PAHs. The remainder of the PAHs in sediment was associated with the heavy density particles (i.e., sand, silt, and clays). Among the different particle types, coal tar pitch (quantified by a quinoline extraction method) contributed the most to the bulk sediment PAH concentration. Aqueous partition coefficients for PAHs measured using a weathered pitch sample from the field were generally an order of magnitude higher than reported for natural organic matter partitioning, and match well with theoretical predictions based on a coal tar-water partitioning model. A pitch-partitioning inclusive model is proposed that gives better estimates of the measured site-specific PAH aqueous equilibrium values than standard estimation based on natural organic matter partitioning only. Thus, for MGP impacted sediments containing weathered pitch particles, the partitioning behavior may be dominated by the sorption characteristics of pitch and not by natural organic matter or black carbon. 25 refs., 5 figs., 1 tab.

  6. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, October 1, 1995--December 31, 1995

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1996-06-01

    As the world continues to deplete its petroleum reserves, lower quality fossil fuels will play an increasingly important role in energy production. Heavy crude oil, coal liquids, and other heavy fossil fuels may be required to meet world energy needs. Heavy fossil fuels are generally higher in molecular weight, more aromatic, and contain more heteroatoms than higher quality petroleum. There will be an increasing need to deal with such low quality feedstocks, and therefore, an incentive to learn more about their properties. There is also significant current interest in the general area of coal pyrolysis, particularly with respect to comprehensive models of this complicated phenomenon. This interest derives from the central role of pyrolysis in all thermally driven coal conversion processes - gasification, combustion, liquefaction, mild gasification, or thermal beneficiation. There remain several key data needs in these application areas. Among them is a need for more reliable correlations for predicting vapor pressures of heavy, primary coal tars. Such information is important in design of all coal conversion processes, in which the volatility of tarry products is of major concern. This work presents results on vapor pressures and vaporization heat of polycyclic aromatic hydrocarbons and mixtures found in coal tar.

  7. Evaluation of some reports on risks to health from exposure to coal-tar-based wood preservatives

    SciTech Connect

    Jacobsen, M.

    1985-11-01

    This report reviews evidence about health risks that may arise in people exposed to coal-tar-based wood preservatives. The limited information available that is relevant directly to possible effects in humans is assessed critically, from an epidemiological point of view. It is concluded that body contact with this class of materials can produce inflammatory skin conditions and benign tumors. The need for effective action to reduce the incidence of this kind of response is emphasized because there is fairly strong evidence that, under adverse conditions, such benign skin lesions may be precursors for skin cancer. There is no evidence that coal-tar distillate fractions with boiling points below 360 C (the main part of the mixtures used in timber preservation) can themselves give rise to skin cancer in man.

  8. Migration and natural fate of a coal tar creosote plume. 2. Mass balance and biodegradation indicators

    NASA Astrophysics Data System (ADS)

    King, Mark W. G.; Barker, James F.; Devlin, John F.; Butler, Barbara J.

    1999-10-01

    A source of coal tar creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. A mass balance indicated that ongoing transformation occurred for seven study compounds. Phenol migrated as a discrete slug plume and almost completely disappeared after 2 years, after being completely leached from the source early in the study. The m-xylene plume migrated outward to a maximum distance at approximately 2 years, and then receded back towards the source as the rate of mass flux out of the source decreased to below the overall rate of plume transformation. Carbazole showed similar behaviour, although the reversal in plume development occurred more slowly. The dibenzofuran plume remained relatively constant in extent and mass over the last 2 years of monitoring, despite constant source input over this period, providing evidence that the dibenzofuran plume was at steady state. Meanwhile, the naphthalene and 1-methylnaphthalene plumes continued to advance and increase in mass over the observation period, although at a decreasing rate. The phenanthrene plume was also subject to transformation, although measurement of the rate was less conclusive due to the higher proportion of sorbed mass for this compound. Three lines of evidence are presented to evaluate whether the observed plume mass loss was due to microbial biodegradation. Measurement of redox-sensitive parameters in the vicinity of the plume showed the types of changes that would be expected to occur due to plume biodegradation: dissolved oxygen and SO 42- decreased in groundwater within the plume while significant increases were noted for Fe 2+, Mn 2+ and methane. Further evidence that plume mass loss was microbially-mediated was provided by the accumulation of aromatic acids within the plume. Measurements of phospholipid fatty acids (PLFA) in aquifer material indicated that microbial biomass and turnover rate were greater within the plume

  9. Separation of nitrogen heterocyclic compounds from model coal tar fraction by solvent extraction

    SciTech Connect

    Kim, S.J.; Chun, Y.J.

    2005-07-01

    The separation of four kinds of nitrogen heterocyclic compounds (NHCs) from a model mixture comprising NHCs (indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)), three kinds of bicyclic aromatic compounds (BACs; 1-methyl-naphthalene (IMN), 2-methyl naphthalene (2MN), dimethylnaphthalene (DMN)), biphenyl (Bp) and phenyl ether (Pe) was examined by a solvent extraction. The model mixture used as a raw material of this work was prepared according to the components and compositions contained in coal tar fraction (the temperature ranges of fraction: 240-265{sup o}C). An aqueous solution of methanol, ethanol, iso-propyl alcohol, N,N-dimethyl acetamide, DMF, formamide, N-methylformamide/methanol, and formamide/methanol were used as solvents. An aqueous solution of formamide was found suitable for separating NHCs contained in coal tar fraction based on distribution coefficient and selectivity. The effect of operation factors on separating NHCs was investigated by the distribution equilibrium using an aqueous solution of formamide. Increasing the operation temperature and the volume ratio of solvent to feed at initial (S/F)(o) resulted in improving the distribution coefficients of each NHC, but increasing the volume fraction of water in the solvent at initial (y(w,O)) resulted in deteriorating the distribution coefficients of each NHC. With increasing y(w,O) and (S/F)(o), the selectivities of each NHC in reference to DMN increased. Increase in operation temperature resulted in decrease in selectivities of each NHC in reference to DMN. At an experimental condition fixed, the sequence of the distribution coefficient and selectivity in reference to DMN for each NHC was In {gt} iQ {gt} Q {gt} Qu, and also the sequence of the distribution coefficient for each BAC was IMN {gt} 2MN {gt} DMN. The sequence of the distribution coefficient for entire compounds analyzed by this work was In {gt} iQ {gt} Q {gt} Qu {gt} BP {gt} 1MN {gt} 2MN {gt} Pe {gt} DMN.

  10. Tumors and DNA adducts in mice exposed to benzo[a]pyrene and coal tars: implications for risk assessment.

    PubMed Central

    Goldstein, L S; Weyand, E H; Safe, S; Steinberg, M; Culp, S J; Gaylor, D W; Beland, F A; Rodriguez, L V

    1998-01-01

    Current methods to estimate the quantitative cancer risk of complex mixtures of polycyclic aromatic hydrocarbons (PAH) such as coal tar assume that overall potency can be derived from knowledge of the concentration of a few carcinogenic components such as benzo[a]pyrene (B[a]P). Genotoxic damage, such as DNA adducts, is thought to be an essential aspect of PAH-induced tumorigenesis and could be a biomarker for exposure useful for estimating risk. However, the role of B[a]P and the relationship of adduct formation in tumorigenesis have not been tested rigorously in models appropriate for human health risk assessment. Therefore, we directly compared tumor induction and adduct formation by B[a]P and coal tars in several experimental protocols, including one broadly accepted and used by regulators. We found that B[a]P content did not account for tumor incidences after exposure to coal tars. DNA adducts were found in both tumors and tumor-free tissue and tumor outcomes were not predicted by either quantitation of total DNA adducts or by the DNA adduct formed by B[a]P. These data suggest that risk assessments based on B[a]P content may not predict accurately risk to human health posed by environmental PAH. PMID:9860888

  11. Allergies

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Allergies Share Tweet Linkedin Pin it More sharing options ... clear up within a week. Learn More about Allergies Food Allergies: What You Need to Know Environmental ...

  12. Allergies

    MedlinePlus

    ... treat some allergies using medicines and allergy shots. Avoidance In some cases, as with food allergies, avoiding ... that might contain even tiny traces of them. Avoidance can help protect people against non-food or ...

  13. Allergy

    MedlinePlus

    ... use skin and blood tests to diagnose allergies. Treatments include medicines, allergy shots, and avoiding the substances that cause the reactions. NIH: National Institute of Allergy and Infectious Diseases

  14. Formation of DNA adducts in the skin of psoriasis patients, in human skin in organ culture, and in mouse skin and lung following topical application of coal-tar and juniper tar.

    PubMed

    Schoket, B; Horkay, I; Kósa, A; Páldeák, L; Hewer, A; Grover, P L; Phillips, D H

    1990-02-01

    Preparations of coal-tar and juniper tar (cade oil) that are used in the treatment of psoriasis are known to contain numerous potentially carcinogenic polycyclic aromatic hydrocarbons (PAH). Evidence of covalent binding to DNA by components of these mixtures was sought in a) human skin biopsy samples from 12 psoriasis patients receiving therapy with these agents, b) human skin explants maintained in organ culture and treated topically with the tars, and c) the skin and lungs of mice treated with repeated doses of the formulations following the regimen used in the clinic. DNA was isolated from the human and mouse tissues and digested enzymically to mononucleotides. 32P-Post-labeling analysis revealed the presence of aromatic DNA adducts in the biopsy samples at levels of up to 0.4 fmol total adducts/microgram DNA. Treatment of human skin in organ culture produced similar levels of adducts, while treatment with dithranol, a non-mutagenic therapeutic agent, resulted in chromatograms indistinguishable from those from untreated controls. In mouse skin, coal-tar ointment and juniper tar gave similar DNA adduct levels, with a similar time-course of removal: maximum levels (0.5 fmol/microgram DNA) at 24 h after the final treatment declined rapidly to 0.05 fmol/microgram at 7 d, thereafter declining slowly over the succeeding 25 d. However, while coal-tar ointment produced only very low levels of adducts in mouse lung (less than 0.03 fmol/microgram DNA), juniper tar produced adducts at a high level (0.7 fmol/microgram DNA) that were persistent in this tissue. These results provide direct evidence for the formation of potentially carcinogenic DNA damage in human and mouse tissue by components of these therapeutic tar preparations.

  15. Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Burbank, T.L.; Ennis, T.E.; Bashara, T.J.

    2010-01-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coaltar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ??g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ??g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ??g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ??g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. ?? 2010 American Chemical Society.

  16. Determination of coal tar and creosote constituents in the aquatic environment.

    PubMed

    Hale, R C; Aneiro, K M

    1997-07-11

    Creosote and its parent material, coal tar, are complex mixtures. Upon release their components fractionate into the air, water, soil/sediment and biota; as a function of their physical and chemical properties. Therefore, assessment of their fate and concentrations in the environment must consider a wide variety of both compounds and matrices. Analyses are typically complicated, consisting of sample extraction, purification and chromatography-based final characterization steps. Several new techniques have been introduced to reduce or simplify the number of steps, solvent and time required. Recently developed extraction methods include supercritical fluid, accelerated solvent, microwave and solid-phase microextraction. On-line purification and coupling of extraction and chromatography have also emerged. HPLC and GC remain the major tools for performing the final separations. Application of mass spectrometry has increased as more reliable, versatile and less expensive units have become available, such as the ion trap and mass selective detectors. Fluorescence and diode array UV, in concert with HPLC, and C-, S- and N-selective gas chromatographic detectors are also being applied.

  17. Influence of laminar flow on preorientation of coal tar pitch structural units: Raman microspectroscopic study

    NASA Astrophysics Data System (ADS)

    Urban, O.; Jehlička, J.; Pokorný, J.; Rouzaud, J. N.

    2003-08-01

    In order to estimate the role of laminar flow of viscous, aromatic matter of carbonaceous precursor on microtextural preorientation in pregraphitization stage, we performed experiments with coal tar pitch (CTP). The principal hypothesis of preorientation of basic structural units (BSUs) in the case of laminar flow (pressure impregnation of CTP into porous matrix) and secondary release of volatiles during carbonization were studied. Glass microplates, planar porous medium with average distance between single microplates 5 μm were used as suitable porous matrix. Samples of CTP were carbonized up to 2500 °C. Optical microscopy reveals large flow domains in the sample of cokes carbonized between glass microplates. Raman microspectroscopy and high resolution transmission electron microscopy (HRTEM) show that at nanometric scale, the samples do not support the proposed hypotheses. With increasing temperature of pyrolysis, the graphitization of CTP impregnated into porous matrix proceeds to lower degree of structural ordering in comparison with single pyrolyzed CTP. This is explained by the release of volatile matter during carbonization in geometrically restricted spaces. More evident structural changes were discovered with the sample of single coke, where parts of fine grain mosaics, relicts of 'so called QI parts', reveal higher structural organization, in comparison with large and prolonged flow domains, similar to flow domains of cokes from microplates.

  18. Embryotoxic and teratogenic effects of aqueous extracts of tar from a coal gasification electrostatic precipitator.

    PubMed

    Schultz, T W; Dumont, J N; Clark, B R; Buchanan, M V

    1982-01-01

    Aqueous extracts of tar from a coal gasification electrostatic precipitator were tested for its toxic and teratogenic potential in vitro on embryos of the amphibian Xenopus laevis. The 96-h LC50 and EC50 were determined to be 0.83% and 0.48%, respectively. The developmental stage of normal-appearing exposed embryos is not affected by increasing concentrations of the extract. Embryo growth, however, is significantly reduced at concentrations as low as 0.25%. Motility and pigmentation were effectively reduced relative to controls by extract concentrations of 0.5% and greater. Exposed embryos are shorter and stockier than controls. Malformations of head, eyes, viscera, and spine are common, and cartilage formation is abnormal. The epidermis is often hyperplastic, and large blisters occur over the somatic surface. The severity of abnormal development is directly related to the concentration of the toxicant to which the embryos are exposed. Chemical analysis shows that the aqueous extracts contain phenols, furans, monoaromatic and diaromatic hydrocarbons, and mono- and diazaarenes and/or monoaromatic amines.

  19. Evolution of bacterial community during bioremediation of PAHs in a coal tar contaminated soil.

    PubMed

    Lors, Christine; Ryngaert, Annemie; Périé, Frédéric; Diels, Ludo; Damidot, Denis

    2010-11-01

    The monitoring of a windrow treatment applied to soil contaminated by mostly 2-, 3- and 4-ring PAHs produced by coal tar distillation was performed by following the evolution of both PAH concentration and the bacterial community. Total and PAH-degrading bacterial community structures were followed by 16S rRNA PCR-DGGE in parallel with quantification by bacterial counts and 16 PAH measurements. Six months of biological treatment led to a strong decrease in 2-, 3- and 4-ring PAH concentrations (98, 97 and 82% respectively). This result was associated with the activity of bacterial PAH-degraders belonging mainly to the Gamma-proteobacteria, in particular, the Enterobacteria and Pseudomonas genera, which were detected over the course of the treatment. This group was considered to be a good bioindicator to determine the potential PAH biodegradation of contaminated soil. Conversely, other species, like the Beta-proteobacteria, were detected after 3months, when 2-, 3- and 4-ring PAHs were almost completely degraded. Thus, presence of the Beta-proteobacteria group could be considered a good candidate indicator to estimate the endpoint of biotreatment of this type of PAH-contaminated soil.

  20. Basics of compounding with tars.

    PubMed

    Allen, Loyd V

    2013-01-01

    Tar has been used throughout history for numerous purposes; from sealing the hulls of ships to sealing roofs of dwellings and even for medical purposes. Produced by destructive distillation, commonly used tars are prepared from coal and wood. Coal tar, juniper tar, and pine tar are used for various medical purposes as described in the article. Also presented are the various characteristics and uses of each tar, along with commercial products and numerous compounding formulas. Techniques used to compound with tars are also presented.

  1. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 July 1993--30 September 1993

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1993-12-31

    There is significant current interest in general area of coal pyrolysis, particularly with respect to comprehensive models of this complicated phenomenon. This interest derives from the central role of pyrolysis in all thermally driven coal conversion processes -- gasification, combustion, liquefaction, mild gasification, or thermal benefication. There remain several key data needs in these application areas. Among them is a need for more reliable correlation for prediction of vapor pressure of heavy, primary coal tars. Such information is important in design of all coal conversion processes, in which the volatility of tarry products is of major concern. Only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. Results of the literature survey are compiled. The experimental tasks have been concerned with setup and calibration.

  2. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 January 1995--31 March 1995

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1995-08-01

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do not lend themselves well for application to very complex, poorly characterized coal tars. The methods based upon more global types of characterizations have not yet dealt much with the question of oxygenated functional groups. In short, only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. A significant amount of time has been devoted during this quarter to testing the equipment for measurements by the Knudsen effusion method. The basic technique was described in the 9th Quarterly Report how the performance of the apparatus was checked by measuring, as a function of temperature, the vapor pressures of anthracene between 25 and 130{degrees}C, pyrene between 35 and 125{degrees}C, and coronene between 145 and 235{degrees}C.

  3. Effect of tar fractions from coal gasification on nickel-yttria stabilized zirconia and nickel-gadolinium doped ceria solid oxide fuel cell anode materials

    NASA Astrophysics Data System (ADS)

    Lorente, E.; Berrueco, C.; Millan, M.; Brandon, N. P.

    2013-11-01

    The allowable tar content in gasification syngas is one of the key questions for the exploitation of the full potential of fuel cell concepts with integrated gasification systems. A better understanding of the interaction between tars and the SOFC anodes which leads to carbon formation and deposition is needed in order to design systems where the extent of gas cleaning operations is minimized. Model tar compounds (toluene, benzene, naphthalene) have been used in experimental studies to represent those arising from biomass/coal gasification. However, the use of toluene as a model tar overestimates the negative impact of a real gasification tar on SOFC anode degradation associated with carbon formation. In the present work, the effect of a gasification tar and its distillation fractions on two commercially available fuel cell anodes, Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium doped ceria), is reported. A higher impact of the lighter tar fractions was observed, in terms of more carbon formation on the anodes, in comparison with the whole tar sample. The characterization of the recovered tars after contact with the anode materials revealed a shift towards a heavier molecular weight distribution, reinforcing the view that these fractions have reacted on the anode.

  4. Fast remediation of coal-tar-related compounds in biofilm bioreactors.

    PubMed

    Guieysse, B; Mattiasson, B

    1999-10-01

    The biological degradation of complex mixtures of recalcitrant substances is still a major challenge in environmental biotechnology and the remediation of coal-tar constitutes one such problem area. Biofilm bioreactors offer many advantages and may be successfully used for this purpose. Two stirred-tank reactors and one packed-bed reactor were tested in a continuous mode. Continuous cultivation allows microbial selection to take place whilst adhesive growth provides a high degradation capacity and process stability. The reactors were inoculated with mixed microbial populations to favour complete metabolism and to prevent metabolite accumulation and substrate inhibition effects. Phenol, o-cresol, quinoline, dibenzofuran, acenaphthene and phenanthrene were used as model contaminants and constituted the sole energy and carbon sources. The hydraulic retention time (HRT) was initially set to 2.5 days for a period of several months to allow the establishment of a stable biofilm and was then gradually decreased. All the compounds were found to be degraded by more than 90% at HRT of 3 h or more. Neither substrate inhibition nor metabolite accumulation effects were observed. The stirred-tank configuration was found to be the most efficient for use with high loads. No improvement in the degradation capacity could be achieved by increasing the biofilm surface in these reactors, illustrating that the limiting factor may be the mass transfer limitations rather than the availability of the biofilm surface. Finally, anaerobic treatment was successfully achieved, confirming the potential for remediation of contaminated sites under anaerobic conditions, providing that alternative electron acceptors are present.

  5. Response of microbial activities and diversity to PAHs contamination at coal tar contaminated land

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaohui; Sun, Yujiao; Ding, Aizhong; Zhang, Dan; Zhang, Dayi

    2015-04-01

    Coal tar is one of the most hazardous and concerned organic pollutants and the main hazards are polycyclic aromatic hydrocarbons (PAHs). The indigenous microorganisms in soils are capable to degrade PAHs, with essential roles in biochemical process for PAHs natural attenuation. This study investigated 48 soil samples (from 8 depths of 6 boreholes) in Beijing coking and chemistry plant (China) and revealed the correlation between PAHs contamination, soil enzyme activities and microbial community structure, by 16S rRNA denaturing gradient gel electrophoresis (DGGE). At the site, the key contaminants were identified as naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene, and the total PAHs concentration ranged from 0.1 to 923.9 mg/kg dry soil. The total PAHs contamination level was positively correlated (p<0.05) with the bacteria count (0.9×107-14.2×107 CFU/mL), catalase activities (0.554-6.230 mL 0.02 M KMnO4/g•h) and dehydrogenase activities (1.9-30.4 TF μg/g•h soil), showing the significant response of microbial population and degrading functions to the organic contamination in soils. The PAHs contamination stimulated the PAHs degrading microbes and promoted their biochemical roles in situ. The positive relationship between bacteria count and dehydrogenase activities (p<0.05) suggested the dominancy of PAHs degrading bacteria in the microbial community. More interestingly, the microbial community deterioration was uncovered via the decline of microbial biodiversity (richness from 16S rRNA DGGE) against total PAHs concentration (p<0.05). Our research described the spatial profiles of PAHs contamination and soil microbial functions at the PAHs heavily contaminated sites, offering deeper understanding on the roles of indigenous microbial community in natural attenuation process.

  6. Benzene Degradation by a Variovorax Species within a Coal Tar-Contaminated Groundwater Microbial Community.

    PubMed

    Posman, Kevin M; DeRito, Christopher M; Madsen, Eugene L

    2017-02-15

    Investigations of environmental microbial communities are crucial for the discovery of populations capable of degrading hazardous compounds and may lead to improved bioremediation strategies. The goal of this study was to identify microorganisms responsible for aerobic benzene degradation in coal tar-contaminated groundwater. Benzene degradation was monitored in laboratory incubations of well waters using gas chromatography mass spectrometry (GC-MS). Stable isotope probing (SIP) experiments using [(13)C]benzene enabled us to obtain (13)C-labled community DNA. From this, 16S rRNA clone libraries identified Gammaproteobacteria and Betaproteobacteria as the active benzene-metabolizing microbial populations. Subsequent cultivation experiments yielded nine bacterial isolates that grew in the presence of benzene; five were confirmed in laboratory cultures to grow on benzene. The isolated benzene-degrading organisms were genotypically similar (>97% 16S rRNA gene nucleotide identities) to the organisms identified in SIP experiments. One isolate, Variovorax MAK3, was further investigated for the expression of a putative aromatic ring-hydroxylating dioxygenase (RHD) hypothesized to be involved in benzene degradation. Microcosm experiments using Variovorax MAK3 revealed a 10-fold increase in RHD (Vapar_5383) expression, establishing a link between this gene and benzene degradation. Furthermore, the addition of Variovorax MAK3 to microcosms prepared from site waters accelerated community benzene degradation and correspondingly increased RHD gene expression. In microcosms using uninoculated groundwater, quantitative (q)PCR assays (with 16S rRNA and RDH genes) showed that Variovorax was present and responsive to added benzene. These data demonstrate how the convergence of cultivation-dependent and -independent techniques can boost understandings of active populations and functional genes in complex benzene-degrading microbial communities.

  7. PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.

    2013-01-01

    Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998–2005 to 2006–2014 (means of 7980 and 4500 μg kg–1, respectively), and by 2012–2014, the decline was about 58% (mean of 3320 μg kg–1). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959–1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

  8. Modeling the long-term and transient evolution of biogeochemical and isotopic signatures in coal tar-contaminated aquifers

    NASA Astrophysics Data System (ADS)

    D'Affonseca, Fernando Mazo; Prommer, Henning; Finkel, Michael; Blum, Philipp; Grathwohl, Peter

    2011-05-01

    Reactive transport modeling is a critical element in assessing the potential of natural attenuation of groundwater pollutants. In the present study, we developed a comprehensive quantitative model that incorporates the key processes affecting the long-term fate of complex organic compound mixtures released from coal tar-type dense nonaqueous phase liquid sources. The model framework addresses the simulation of the long-term dynamics of source zone depletion, the fate of the released compounds during reactive transport in the groundwater, the evolution of the aquifer's biogeochemical response, in particular its redox conditions, and the redox-dependent carbon isotope fractionation of selected organic compounds. The modeling framework was applied for the interpretation of observed biogeochemical and isotopic data from a well-characterized coal tar-contaminated site in northern Germany. The simulations highlight the diversity of fates of the individual compounds, which result from their widely varying physicochemical characteristics, and also how complex interactions develop over the lifetime of the contamination. The highly transient release of contaminants from the coal tar as pool and as heterogeneously distributed blobs in the source zone triggers continuously changing biogeochemical conditions and isotope signatures. The modeling results illustrate how difficult and uncertain the assessment of contaminant fate can be if the collected data cover only a small time window relative to the transport time scale. This emphasizes the need for a holistic understanding of the governing processes that control the effectiveness of monitored natural attenuation before it is implemented as a passive remediation strategy at nonaqueous phase liquid-contaminated sites.

  9. PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas.

    PubMed

    Van Metre, Peter C; Mahler, Barbara J

    2014-07-01

    Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin's ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998-2005 to 2006-2014 (means of 7980 and 4500 μg kg(-1), respectively), and by 2012-2014, the decline was about 58% (mean of 3320 μg kg(-1)). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959-1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

  10. Pyridine and other coal tar constituents as inhibitors of potato polyphenol oxidase: a non-animal model for neurochemical studies.

    PubMed

    Henderson, H M; Eskin, N A; Pinsky, C; Bose, R; Ashique, A M

    1992-01-01

    Potato polyphenol oxidase activity was strongly and noncompetitively inhibited by the "Perov mixture" of coal tar components and by pyridine alone, while phenol competitively inhibited the enzyme. These two inhibitors are structural components of the parkinsonogenic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By extension, dopamine and neuromelanin synthesis in the brain may be influenced by the inhibitory effects of such compounds upon the copper-dependent steps of tyrosine metabolism. The non-animal model used in this study may represent an alternative to the use of animal tissues in neurodegenerative disease research.

  11. Charge/discharge characteristics of the coal-tar pitch carbon as negative electrode in Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Sik

    The charge/discharge characteristics were studied for the coal-tar pitch-based carbon (CTPC), which was pyrolyzed under the condition to form anisotropic mesophase pitch and then heat treated at temperatures ranging from 500 to 1300°C in N 2 atmosphere. As the heat treatment temperature increased, the reversible capacity for the CTPC increased progressively up to 1000°C, while the irreversible capacity decreased continuously. Carbons synthesized through the extraction of anisotropic mesophases showed higher reversible and lower irreversible capacities than the directly pyrolyzed ones.

  12. Pyridine and other coal tar constituents as inhibitors of potato polyphenol oxidase: A non-animal model for neurochemical studies

    SciTech Connect

    Henderson, H.M.; Eskin, N.A.M.; Pinsky, C.; Bose, R.; Ashique, A.M. )

    1992-01-01

    Potato polyphenol oxidase activity was strongly and noncompetitively inhibited by the 'Perov mixture' of coal tar components and by pyridine alone, while phenol competitively inhibited the enzyme. These two inhibitors are structural components of the parkinsonogenic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By extension, dopamine and neuromelanin synthesis in the brain may be influenced by the inhibitory effects of such compounds upon the copper-dependent steps of tyrosine metabolism. The non-animal model used in this study may represent an alternative to the use of animal tissues in neurodegenerative disease research.

  13. Coal occurrence and characteristics as related to environment of deposition in Cerro Negro area of Orinoco Tar Sands, Venezuela

    SciTech Connect

    Rodriguez, A.

    1983-03-01

    Sedimentological analysis of cores taken in the Cerro Negro area of the Orinoco Tar Sands have provided lithological, textural, mineralogical, and paleontological data which have enabled facies identification. These facies have been interpreted as belonging from an upper delta plain to a semi-restricted shallow marine environment of deposition. Coal beds occur in all the wells analyzed. These occurrences are closely associated with specific facies, such as the back-barrier lagoonal facies of the semirestricted environment of deposition and the backswamp facies of the delta plain. More importantly these coal beds present very distinguishable characteristics, such as variation in thickness from few inches in the back-barrier facies to 5 ft (1.5 m) in the delta plain facies. Their organic composition also ranges from micrite/atrinite to vitrinite and exinite in different proportions. Therefore, it is believed that variations in thickness and perhaps in organic composition are related to facies changes.

  14. PAH Concentrations Decline Following 2006 Ban on Coal-Tar-Based Pavement Sealants in Austin, Texas

    NASA Astrophysics Data System (ADS)

    Van Metre, P. C.; Mahler, B. J.

    2013-12-01

    Recent studies have concluded that coal-tar-based pavement sealants (CT sealants) are a major source of polycyclic aromatic hydrocarbons (PAHs) in non-industrial urban settings in the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of CT sealants. We evaluated PAH concentrations following the ban by analyzing sediment cores collected from Lady Bird Lake in 2012; Lady Bird Lake impounds the Colorado River in central Austin and receives runoff from much of the greater Austin area. The mean sum concentration of the 16 U.S. Environmental Protection Agency Priority Pollutant PAHs (∑PAH16) in one of two 2012 sediment cores analyzed for PAHs declined 75% from before 2006 (mean of 4 samples=8,090 μg kg-1) to 2012 (mean of 2 samples=2,030 μg kg-1), reversing a 40-year (1959-1999) upward trend in PAH concentrations that was previously documented. The downward trend in PAH concentrations in the seven uppermost 1 cm sampling intervals in the first 2012 core was statistically significant (r=0.93, p-value=0.002). Post-2008 PAH trends in the second 2012 core were similar (significant downward trend in the six uppermost 1 cm sampling intervals and mean 2012 ∑PAH16 of 2,390 μg kg-1); however, pre-2007 sediment did not appear to have been preserved in this core likely because of the effects of flooding on sediment deposition and mixing at this site--the largest flood on the Colorado River in Austin in 20 years was in 2007. On the basis of a comparison of lake-sediment PAH profiles to 22 PAH source profiles, the PAH loading to lake sediment continues to be dominated by CT sealants. The continued dominance of proportional PAH loading by CT sealants in spite of decreased concentrations since 2006 might be because legacy CT sealant and contaminated soils and sediments continue to yield PAHs to runoff. A previous study using source-receptor modeling concluded that CT sealants were the largest PAH source to 40 urban lakes studied in the

  15. Benzene Degradation by a Variovorax Species within a Coal Tar-Contaminated Groundwater Microbial Community

    PubMed Central

    Posman, Kevin M.; DeRito, Christopher M.

    2016-01-01

    ABSTRACT Investigations of environmental microbial communities are crucial for the discovery of populations capable of degrading hazardous compounds and may lead to improved bioremediation strategies. The goal of this study was to identify microorganisms responsible for aerobic benzene degradation in coal tar-contaminated groundwater. Benzene degradation was monitored in laboratory incubations of well waters using gas chromatography mass spectrometry (GC-MS). Stable isotope probing (SIP) experiments using [13C]benzene enabled us to obtain 13C-labled community DNA. From this, 16S rRNA clone libraries identified Gammaproteobacteria and Betaproteobacteria as the active benzene-metabolizing microbial populations. Subsequent cultivation experiments yielded nine bacterial isolates that grew in the presence of benzene; five were confirmed in laboratory cultures to grow on benzene. The isolated benzene-degrading organisms were genotypically similar (>97% 16S rRNA gene nucleotide identities) to the organisms identified in SIP experiments. One isolate, Variovorax MAK3, was further investigated for the expression of a putative aromatic ring-hydroxylating dioxygenase (RHD) hypothesized to be involved in benzene degradation. Microcosm experiments using Variovorax MAK3 revealed a 10-fold increase in RHD (Vapar_5383) expression, establishing a link between this gene and benzene degradation. Furthermore, the addition of Variovorax MAK3 to microcosms prepared from site waters accelerated community benzene degradation and correspondingly increased RHD gene expression. In microcosms using uninoculated groundwater, quantitative (q)PCR assays (with 16S rRNA and RDH genes) showed that Variovorax was present and responsive to added benzene. These data demonstrate how the convergence of cultivation-dependent and -independent techniques can boost understandings of active populations and functional genes in complex benzene-degrading microbial communities. IMPORTANCE Benzene is a human

  16. Airborne concentrations, skin contamination, and urinary metabolite excretion of polycyclic aromatic hydrocarbons among paving workers exposed to coal tar derived road tars

    SciTech Connect

    Jongeneelen, F.J.; Scheepers, P.T.; Groenendijk, A.; Van Aerts, L.A.; Anzion, R.B.; Bos, R.P.; Veenstra, S.J.

    1988-12-01

    The exposure of surface dressing workers to polycyclic aromatic hydrocarbons (PAH) was studied. Four different paving sites, at which coal tar-containing binders were applied, were selected as work sites with high exposure levels of PAH. Breathing zone airborne particulates, contamination of the skin with PAH, and 1-hydroxypyrene in urine of the workers involved in chip sealing were determined. Substantial concentrations of cyclohexane-soluble airborne particulate matter were found (GM = 0.2 mg/m3, n = 28). Skin contamination was determined using two different methods: with exposure pads and by hand washing. Pads were mounted on several parts of the body: wrist, elbow, neck, shoulder, and ankle. The pads located on the wrist appeared to be the most contaminated (pyrene: GM = 22 ng/1.77 cm2, n = 40). The end-of-shift hand washing showed that the hands of the workers were contaminated with PAH (pyrene: GM = 70 micrograms, n = 35). Preshift hand washing showed far lower, but detectable, quantities of PAH on workers' hands (pyrene: GM = 5 micrograms, n = 35). Enhanced levels of urinary 1-hydroxypyrene among the workers were found. The highest levels were found in the end-of-shift urine samples. Correlations between the pyrene exposure variables were studied. Significant positive correlations were found between pyrene on the wrist pad versus end-of-shift urinary 1-hydroxypyrene; between pyrene on the hands versus end-of-shift urinary 1-hydroxypyrene; and between the two different skin contamination variables.

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

    USGS Publications Warehouse

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

    2014-01-01

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

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

    PubMed

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

    2014-05-01

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

  19. Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    USGS Publications Warehouse

    Hult, Marc F.; Schoenberg, Michael

    1981-01-01

    Operation of a coal-tar distillation and wood preserving plant for 1918-72 in St. Louis Park, Minnesota, resulted in ground-water contamination. This report presents the results of the first year (1979) of an ongoing study. By 1932, water in the Prairie du Chien-Jordan aquifer, the region 's major source of ground water, was contaminated 3,500 feet from the plant. The hydraulic characteristics of the Prairie du Chien-Jordan aquifer , its long contamination history, and fluctuating pumpage combine to creat a complex distribution of coal-tar derivatives observed in the aquifer. The Prairie du Chien-Jordan aquifer underlies the area at depths of 250 to 500 feet and is overlain by two bedrock aquifers (Platteville and St. Peter), two confining beds (Glenwood and basal part of St. Peter), and 70 to 100 feet of glacial drift. Multiaquifer wells in the area have permitted contaminated water from near-surface aquifers to flow downward into the Prairie du Chien-Jordan aquifer. Flow rates of 20 to 150 gallons per minute from the shallower aquifers into the Prairie du Chien-Jordan aquifer were observed in five wells. In the drift, a hydrocarbon fluid phase is moving vertically downward relative to the aqueous phase. Dissolved constituents in the drift and Platteville aquifer, the uppermost bedrock unit over most of the area, have moved at least 4,000 feet. Low-molecular-weight compounds are moving preferentially through the drift and Platteville aquifer system. (USGS)

  20. Potential consolidation-induced NAPL migration from coal tar impacted river sediment under a remedial sand cap.

    PubMed

    Kim, Yong Sang; Jafvert, Chad T; Yoon, Sungmin; Hyun, Seunghun; Johnson, Brian

    2009-03-15

    Subaqueous sediment, if capped for remediation purposes, may undergo consolidation due to the increased effective weight of the capping material. The standard Atterberg limits test and a modified drained three-dimensional consolidation test (DTCT) were performed on sediment collected from a river adjacent to a former manufactured gas plant site that contains high concentrations of coal tar. The plastic limit of five sediment samples ranged between 72 and 89%, and the liquid limit ranged between 123 and 194%. The plasticity index ranged from 51 to 122%, with the values among the sediments correlating with the coal tar content (r(2)=0.93). DTCT experiment was performed on 5 cm sediment overlain with 5 cm sand to a maximum applied effective cell pressure of 41.4 kPa. Consolidation increased almost linearly at lower pressures (<13.8 kPa); however, as higher pressures were imposed, the ratio of consolidation per applied pressure decreased. The results of this study suggest that porewater advection, resulting from sediment consolidation, will occur from the sediment to the capping material. Because this water will contain numerous polycyclic aromatic hydrocarbons, measures, such as adding sorptive materials, should be taken to reduce the flux of these compounds.

  1. Influence of coal-tar sealcoat and other carbonaceous materials on polycyclic aromatic hydrocarbon loading in an urban watershed

    USGS Publications Warehouse

    Yang, Y.; Van Metre, P.C.; Mahler, B.J.; Wilson, J.T.; Ligouis, B.; Razzaque, M.; Schaeffer, D.J.; Werth, C.J.

    2010-01-01

    Carbonaceous material (CM) particles are the principal vectors transporting polycyclic aromatic hydrocarbons (PAHs) into urban waters via runoff; however, characteristics of CM particles in urban watersheds and their relative contributions to PAH contamination remain unclear. Our objectives were to identify the sources and distribution of CM particles in an urban watershed and to determine the types of CMs that were the dominant sources of PAHs in the lake and stream sediments. Samples of soils, parking lot and street dust, and streambed and lake sediment were collected from the Lake Como watershed in Fort Worth, Texas. Characteristics of CM particles determined by organic petrography and a significant correlation between PAH concentrations and organic carbon in coal tar, asphalt, and soot indicate that these three CM particle types are the major sources and carriers of PAHs in the watershed. Estimates of the distribution of PAHs in CM particles indicate that coal-tar pitch, usedinsomepavementsealcoats, isadominant source of PAHs in the watershed, and contributes as much as 99% of the PAHs in sealed parking lot dust, 92% in unsealed parking lot dust, 88% in commercial area soil, 71% in streambed sediment, and 84% in surficial lake sediment. ?? 2010 American Chemical Society.

  2. Influence of coal-tar sealcoat and other carbonaceous materials on polycyclic aromatic hydrocarbon loading in an urban watershed.

    PubMed

    Yang, Yaning; Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer T; Ligouis, Bertrand; Razzaque, M D Muhit; Schaeffer, David J; Werth, Charles J

    2010-02-15

    Carbonaceous material (CM) particles are the principal vectors transporting polycyclic aromatic hydrocarbons (PAHs) into urban waters via runoff; however, characteristics of CM particles in urban watersheds and their relative contributions to PAH contamination remain unclear. Our objectives were to identify the sources and distribution of CM particles in an urban watershed and to determine the types of CMs that were the dominant sources of PAHs in the lake and stream sediments. Samples of soils, parking lot and street dust, and streambed and lake sediment were collected from the Lake Como watershed in Fort Worth, Texas. Characteristics of CM particles determined by organic petrography and a significant correlation between PAH concentrations and organic carbon in coal tar, asphalt, and soot indicate that these three CM particle types are the major sources and carriers of PAHs in the watershed. Estimates of the distribution of PAHs in CM particles indicate that coal-tar pitch, used in some pavement sealcoats, is a dominant source of PAHs in the watershed, and contributes as much as 99% of the PAHs in sealed parking lot dust, 92% in unsealed parking lot dust, 88% in commercial area soil, 71% in streambed sediment, and 84% in surficial lake sediment.

  3. Fabrication method and microstructural characteristics of coal-tar-pitch-based 2D carbon/carbon composites

    NASA Astrophysics Data System (ADS)

    Esmaeeli, Mohammad; Khosravi, Hamed; Mirhabibi, Alireza

    2015-02-01

    The lignin-cellulosic texture of wood was used to produce two-dimensional (2D) carbon/carbon (C/C) composites using coal tar pitch. Ash content tests were conducted to select two samples among the different kinds of woods present in Iran, including walnut, white poplar, cherry, willow, buttonwood, apricots, berry, and blue wood. Walnut and white poplar with ash contents of 1.994wt% and 0.351wt%, respectively, were selected. The behavior of these woods during pyrolysis was investigated by differential thermal analysis (DTA) and thermo gravimetric (TG) analysis. The bulk density and open porosity were measured after carbonization and densification. The microstructural characteristics of samples were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. The results indicate that the density of both the walnut and white poplar is increased, and the open porosity is decreased with the increasing number of carbonization cycles. The XRD patterns of the wood charcoal change gradually with increasing pyrolysis temperature, possibly as a result of the ultra-structural changes in the charcoal or the presence of carbonized coal tar pitch in the composite's body.

  4. Mortality among workers exposed to coal tar pitch volatiles and welding emissions: an exercise in epidemiologic triage.

    PubMed Central

    Silverstein, M; Maizlish, N; Park, R; Mirer, F

    1985-01-01

    The United Automobile Workers International Union has established a system of epidemiologic triage to evaluate patterns of mortality among groups of union members. In response to worker concerns, the Union examined mortality at a metal stamping plant, using a method which linked pension records with the State of Michigan computerized death registry. The observed proportion of malignant neoplasms was nearly twice that expected (95% Confidence Limits 1.36, 2.62). Two- to five-fold excess proportional mortality from cancer of the digestive organs, lung cancer, and leukemia accounted for most of the overall excess. Strong associations were found between lung and digestive organ cancer and employment as maintenance welders or millwrights in the plant (odds ratios greater than 10). High levels of six polycyclic aromatic hydrocarbons with mutagenic and carcinogenic properties were found during hot coal tar application to wood block floors, work conducted by the high-risk groups. These levels were substantially reduced following the purchase of new tar pots. The example demonstrates that epidemiologic tools can play a valuable role in occupational health decision making, but care must be taken to avoid mechanical reliance on quantitative testing and to acknowledge the important role of social and political value judgments in the establishment of responsible public policy. PMID:4051064

  5. Mortality among workers exposed to coal tar pitch volatiles and welding emissions: an exercise in epidemiologic triage

    SciTech Connect

    Silverstein, M.; Maizlish, N.; Park, R.; Mirer, F.

    1985-11-01

    The United Automobile Workers International Union has established a system of epidemiologic triage to evaluate patterns of mortality among groups of union members. In response to worker concerns, the Union examined mortality at a metal stamping plant, using a method which linked pension records with the State of Michigan computerized death registry. The observed proportion of malignant neoplasms was nearly twice that expected. Two- to five-fold excess proportional mortality from cancer of the digestive organs, lung cancer, and leukemia accounted for most of the overall excess. Strong associations were found between lung and digestive organ cancer and employment as maintenance welders or millwrights in the plant. High levels of six polycyclic aromatic hydrocarbons with mutagenic and carcinogenic properties were found during hot coal tar application to wood block floors, work conducted by the high-risk groups. These levels were substantially reduced following the purchase of new tar pots. The example demonstrates that epidemiologic tools can play a valuable role in occupational health decision making, but care must be taken to avoid mechanical reliance on quantitative testing and to acknowledge the important role of social and political value judgments in the establishment of responsible public policy.

  6. Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    USGS Publications Warehouse

    Hult, Marc F.; Schoenberg, Michael E.

    1984-01-01

    Drift materials on and south of the site have been contaminated by surface spills and by infiltration of contaminated process water. Near the contamination source, a hydrocarbon fluid phase is moving vertically downward relative to movement of the aqueous phase. Fluid pumped from an observation well in this area contained 6,000 milligrams per liter total organic carbon. Dissolved coal-tar constituents in the drift and the uppermost bedrock unit over most of the area, the Platteville aquifer, have moved at least 4,000 feet downgradient to a drift-filled bedrock valley. At the valley, it seems that the Platteville aquifer and the Glenwood confining bed have been removed by erosion and that contaminants with a concentration of approximately 2 milligrams per liter dissolved organic carbon are entering the underlying St. Peter aquifer. Chemical analyses of fluid pumped from observation wells suggest that soluble, low-molecular-weight compounds are moving preferentially through the drift and the Platteville aquifer.

  7. Allergies

    MedlinePlus Videos and Cool Tools

    ... respond by producing antibodies. These antibodies attach to mast cells, which are white blood cells containing the chemical ... As more antibodies are produced, they cause the mast cells to release histamine. Histamine then produces allergy symptoms. ...

  8. Using a battery of bioassays, benthic phytoplankton and the AUSRIVAS method to monitor long-term coal tar contaminated sediment in the Cache la Poudre River, Colorado.

    PubMed

    Oberholster, P J; Botha, A-M; Cloete, T E

    2005-12-01

    This survey provides information on sediment toxicity and structural characteristics of the macroinvertebrates and benthic phytoplankton at 10 locations in the Cache la Poudre River after long-term exposure to coal tar residue. The application of the Australian river bioassessment system (AUSRIVAS) as well as a biotest battery was used to evaluate the river 'health' condition. Coal tar is a dense nonaqueous-phase liquid of significant environmental concern due to its toxicity and persistence in the subsurface. Organisms like Selenastrum capricornutum, Daphnia magna and Chironomus tentans, representing different complexities in the biosphere, were selected as test systems for ecotoxicological studies. The results obtained in this study indicate that a biotest battery, macroinvertebrate and benthic phytoplankton communities are in principle suitable biological tools for evaluation of toxic oil and coal-derived substances in long-term contaminated river sediment.

  9. [The rabbit ear model as an acnegenicity test. 2. Effect of coal tar on follicle and sebaceous gland epithelium tumor induction].

    PubMed

    Zimmermann, R

    1989-01-01

    Tar produced from hard coal was found to be acanthogenic to the interfollicular epiderm of rabbit ear skin and comedogenic to follicular epithelium in short-term (two weeks) and long-term (12 weeks) tests. Histological and autoradiographic experiments revealed a hyperproliferative effect in all cases in long-term tests. This contrasts with the atrophying effects reported by other authors. Tar application reduced the sebaceous gland area per follicle. Benignant epidermal tumours consisting of papillomas with a striking degree of sebaceous gland proliferation appeared on the rabbit ear skin after 8 weeks at the earliest.

  10. Characterisation of dense non-aqueous phase liquids of coal tar using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry.

    NASA Astrophysics Data System (ADS)

    Gauchotte-Lindsay, Caroline; McGregor, Laura; Richards, Phil; Kerr, Stephanie; Glenn, Aliyssa; Thomas, Russell; Kalin, Robert

    2013-04-01

    Comprehensive two-dimensional gas chromatography (GCxGC) is a recently developed analytical technique in which two capillary columns with different stationary phases are placed in series enabling planar resolution of the analytes. The resolution power of GCxGC is one order of magnitude higher than that of one dimension gas chromatography. Because of its high resolution capacity, the use of GCxGC for complex environmental samples such as crude oils, petroleum derivatives and polychlorinated biphenyls mixtures has rapidly grown in recent years. We developed a one-step method for the forensic analysis of coal tar dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plant (FMGP) sites. Coal tar is the by-product of the gasification of coal for heating and lighting and it is composed of thousands of organic and inorganic compounds. Before the boom of natural gases and oils, most towns and cities had one or several manufactured gas plants that have, in many cases, left a devastating environmental print due to coal tar contamination. The fate of coal tar DNAPLs, which can persist in the environment for more than a hundred years, is therefore of crucial interest. The presented analytical method consists of a unique clean-up/ extraction stage by pressurized liquid extraction and a single analysis of its organic chemical composition using GCxGC coupled with time of flight mass spectrometry (TOFMS). The chemical fingerprinting is further improved by derivatisation by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) of the tar compounds containing -OH functions such as alcohols and carboxylic acids. We present here how, using the logical order of elution in GCxGC-TOFMS system, 1) the identification of never before observed -OH containing compounds is possible and 2) the isomeric selectivity of an oxidation reaction on a DNAPL sample can be revealed. Using samples collected at various FMGP sites, we demonstrate how this GCxGC method enables the simultaneous

  11. Potentiation of 2,6-dinitrotoluene genotoxicity in Fischer 344 rats by pretreatment with coal tar creosote.

    PubMed

    Chadwick, R W; George, S E; Kohan, M J; Williams, R W; Allison, J C; Talley, D L; Hayes, Y O; Chang, J

    1995-03-01

    Pretreatment of male Fischer 344 rats for 5 wk with coal tar creosote, a coal distillation product that is widely used as a wood preservative, potentiated the excretion of urinary mutagens in 2,6-dinitrotoluene (DNT) treated rats. Creosote increased the bioactivation of DNT to significantly greater levels of urinary genotoxic metabolites and/or formed DNA adducts in the liver. A significant increase in the excretion of mutagenic DNT metabolites was observed after the first week of creosote treatment, peaked at wk 3, and then decreased by 33% after 5 wk of treatment. Nevertheless, there was a significant increase (66%) in the formation of DNT-derived DNA adducts in the livers of rats treated with DNT plus creosote at wk 5. Increased cecal beta-glucuronidase activity and reduced small intestinal nitroreductase activity may play roles in the bioactivation of DNT. The excretion of mutagenic DNT metabolites supplies useful information about the bioactivation of DNT; it does not provide a useful index of DNT-derived hepatic DNA adduct formation. Such interactions could be important to predictive risk assessment because the overall cancer risk of such chemical mixtures may exceed the sum of the component risks.

  12. Correlation between structure and fluidity of coal tar pitch fractions studied by ambient {sup 13}C and high temperature in-situ {sup 1}H nuclear magnetic resonance

    SciTech Connect

    Andresen, J.M.; Schober, H.H.; Rusinko, F.J. Jr.

    1999-07-01

    The unique properties of coal tar pitches have resulted in numerous applications for carbon products, such as binders for carbon artifacts. However, as the number of by-product coke ovens is diminishing, the design of superior binders from alternative materials or processes is sought by the carbon industry. Accordingly, structural characterization of coal tar pitches and their solvent fractions, using quantitative analytical techniques is required to successfully obtain this goal. Quantitative solid state {sup 13}C NMR has previously been shown to be a powerful technique to study the overall aromatic ring-size for coal tar pitches and their toluene insoluble (TI) fractions. The TI fraction can further be separated into its quinoline soluble part (beta-resin) and insoluble fraction (QI). Both these fractions affect the overall coking yield and especially the fluidity of the pitches. The assessment of fluidity interactions between coal tar pitch solvent fractions during heating is therefore important for the future design of pitches from untraditional sources or processes. High temperature {sup 1}H NMR is a useful technique to investigate the fluid and rigid components of pitches, especially with its interaction with coal and to quantify mesophase. However, very little work has been performed to correlate the overall fluidity behavior of pitch with the mobility of its different solubility fractions and their structure. Accordingly, this paper addresses the fluidity interactions between different pitch solvent fractions (TS, beta-resin and QI) by high temperature {sup 1}H NMR. Particularly, the fluidity studies on the beta-resin alone can verify whether this fraction becomes plastic during heating.

  13. Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.

    2010-01-01

    Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) has increased in the United States during the past 40 years. We evaluated sources of PAHs in post-1990 sediments in cores from 40 lakes in urban areas across the United States using a contaminant mass-balance receptor model and including as a potential source coal-tar-based (CT) sealcoat, a recently recognized source of urban PAH. Other PAH sources considered included several coal- and vehicle-related sources, wood combustion, and fuel-oil combustion. The four best modeling scenarios all indicate CT sealcoat is the largest PAH source when averaged across all 40 lakes, contributing about one-half of PAH in sediment, followed by vehicle-related sources and coal combustion. PAH concentrations in the lakes were highly correlated with PAH loading from CT sealcoat (Spearman's rho=0.98), and the mean proportional PAH profile for the 40 lakes was highly correlated with the PAH profile for dust from CT-sealed pavement (r=0.95). PAH concentrations and mass and fractional loading from CT sealcoat were significantly greater in the central and eastern United States than in the western United States, reflecting regional differences in use of different sealcoat product types. The model was used to calculate temporal trends in PAH source contributions during the last 40 to 100 years to eight of the 40 lakes. In seven of the lakes, CT sealcoat has been the largest source of PAHs since the 1960s, and in six of those lakes PAH trends are upward. Traffic is the largest source to the eighth lake, located in southern California where use of CT sealcoat is rare.

  14. Concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and Azaarenes in Runoff from Freshly Applied Coal-Tar-Based Pavement Sealcoat

    NASA Astrophysics Data System (ADS)

    Mahler, B. J.; Van Metre, P. C.

    2013-12-01

    Coal-tar-based sealcoat (CT-sealcoat) is extensively applied to asphalt parking lots and driveways in the U.S. and Canada. Toxicity to fish and invertebrates of runoff from pavement to which CT-sealcoat has been freshly applied has been reported, but relatively little is known about how concentrations of chemicals in runoff change in the hours to days following sealcoat application. We measured the concentrations of 16 U.S. Environmental Protection Agency Priority Pollutant polycyclic aromatic hydrocarbons (PAHs) and 7 azaarenes in 9 samples of simulated runoff from a coal-tar-sealed test plot collected at increasing intervals from 5 hours to 16 weeks following application. Azaarenes, several of which are common constituents in coal-tar pitch, and their oxidized derivatives, azaarones, are an emerging group of little-studied heterocyclic chemicals. Runoff samples were collected by spraying 25 L of a diluted groundwater to 10 m2 on sealed pavement and retrieving the runoff downgradient where the runoff pooled against spill berms. Unfiltered samples were analyzed by GC/MS following liquid-liquid extraction. In the first sample (t=5 hr), phenanthrene had the highest concentration (130 μg/L) among the 16 PAHs. Concentrations of the lower molecular weight (LMW) PAHs (2 and 3 ring) decreased during the 16 weeks following application, and concentrations of the higher molecular weight (HMW) PAHs (4 to 6 ring) increased, coincident with an increase in the concentration of suspended particulates. In the final sample (t=16 weeks), fluoranthene had the highest concentration (36 μg/L) among the 16 PAHs. Of the azaarenes measured, concentrations of acridine and carbazole (107 and 750 μg/L, respectively) in the initial sample exceeded those of any of the PAHs measured except phenanthrene; acridine and carbazole concentrations decreased over the 5 weeks to <5% of their initial values. Samples of dried sealcoat were analyzed the day of application and 5 weeks later. Samples were

  15. Oil shale, tar sand, coal research, advanced exploratory process technology jointly sponsored research. Quarterly technical progress report, April--June 1992

    SciTech Connect

    Not Available

    1992-12-01

    Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced recovery techniques; and menu driven access to the WDEQ Hydrologic Data Management Systems.

  16. Task 1.15 - Enhanced Bioremediation of Coal Tar-Contaminated Soil

    SciTech Connect

    John R. Gallagher

    1998-02-01

    The remediation of sites where soils have been contaminated with hydrophobic organic compounds is a major problem. This is especially true for manufactured gas plants (MGP) and similar industries. Gasification of fossil fuels has resulted in the production of tars that contain polyaromatic hydrocarbons (PAHs). PAHs are of concern because they are persistent in the environment and because many of them are carcinogenic. When soils contain very high concentrations of PAHs and other tar components, it is generally most feasible to use a chemical-physical remediation technique such as incineration. However, when the contaminant concentrations are medium to low, the most inexpensive technology is generally biological treatment. Biological treatment is an environmentally acceptable method of remediation that is relatively low-cost for many organic contaminants. PAHs and similar hydrophobic compounds, however, present major challenges to the microbial methods. These problems can be broken down into two related areas: mass transfer and bioavailability. The water volubility of most PAW is very small, and they have very low vapor pressures. As a result the diffkion of the sorbed PAHs to a location where a biodegrading microorganism can encounter it is often limiting. Complicating this is that especially in aged samples, the PAHs are bound so strongly to soil components, they are not available for the microorganisms. These two phenomena can be better understood by examination of a typical biodegradation curve, such as might be observed for mixed PAHs. In Figure 1, there are three phases of the biodegradation process plotted with respect to time. In the first phase, concentrations are changing only slowly as the microbes adapt to the conditions, grow to a larger population, and begin to biodegrade the PAHs. The second phase is the phase of rapid, often logarithmic, biodegradation. The third and last phase is that period when available concentrations of PAHs are dropping so that

  17. Size-exclusion chromatography of large molecules from coal liquids, petroleum residues, soots, biomass tars and humic substances.

    PubMed

    Herod, Alan A; Zhuo, Yuqun; Kandiyoti, Rafael

    2003-06-30

    Size-exclusion chromatography (SEC) using 1-methyl-2-pyrrolidinone (NMP) as eluent has been calibrated using various standard polymers and model compounds and applied to the analysis of extracts of coal, petroleum and kerogens, to petroleum vacuum residues, soots, biomass tars and humic substances. Three separate columns of different molecular mass (MM) ranges were used, with detection by UV absorption; an evaporative light scattering detector was used for samples with no UV absorption. Fractionation was useful to separate signal from the less abundant high-mass material, which was normally masked by the strong signal from the more abundant low-mass material in the absence of fractionation. Fractionation methods used to isolate high-mass materials before SEC analysis included planar chromatography, column chromatography and solvent solubility. The apparently large molecules were concentrated into the fractions not soluble in common solvents and were relatively immobile in planar chromatography. All samples and fractions contained some material excluded from the column porosity. Evidence from other techniques suggests that the excluded material is of different structures from that of the resolved material rather than consisting of aggregates of small molecules. We speculate that the excluded material may elute early because the structures of this material are three-dimensional rather than planar or near planar.

  18. Determination and genotoxicity of high molecular mass polycyclic aromatic hydrocarbons isolated from coal-tar-contaminated sediment

    SciTech Connect

    Marvin, C.H.; Lundrigan, J.A.; McCarry, B.E.; Bryant, D.W.

    1995-12-01

    A bioassay-directed chemical fractionation methodology was used to identify the principal mutagenic compounds in an organic solvent extract of coal-tar-contaminated sediment from Sydney Harbor, Nova Scotia. Biological assays with Salmonella typhimurium bacteria with the addition of oxidative metabolism indicated that the majority of the mutagenic activity observed in the sediment extract was associated with the higher molecular mass polycyclic aromatic hydrocarbons (PAHs). A normal phase high-performance liquid chromatography (HPLC) technique was developed to separate the PAH-rich solvent extracts into fractions containing isomeric PAHs of a single benzologue class. These fractions were analyzed by probe mass spectrometry and gas chromatography-mass spectrometry (GC-MS), and subjected to biological assays using strain YG1025 with the addition of oxidative metabolism (4% and 10% S9). Fractions containing compounds of molecular weights 252, 276, 278, and 302 amu exhibited mutagenic activities of 930 {+-} 125, 510 {+-} 100, 250 {+-} 40, and 370 {+-} 140 rev/mg sediment, respectively. The molecular weight 252 and 276 amu fractions were further analyzed using reversed-phase HPLC and GC-MS to identify the individual PAHs responsible for the observed biological activity. High molecular mass PAHs including benzo[a]pyrene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and compounds of molecular weight 302 amu were found to be responsible for the majority of the mutagenic activity displayed by this complex environmental mixture.

  19. Human peripheral blood lymphocytes as a cell model to evaluate the genotoxic effect of coal tar treatment.

    PubMed Central

    Pavanello, S; Levis, A G

    1994-01-01

    Peripheral blood lymphocytes (PBL) from psoriatic patients therapeutically exposed to polycyclic aromatic hydrocarbons (PAH) during coal tar (CT) treatment were used to evaluate the in vivo formation of benzo[a]pyrene diol epoxide(BaPDE)-DNA adducts by an ELISA technique and by the 32P-postlabeling method. Moreover, we controlled if the pretreatment with CT influences the formation of BaP-DNA adducts and the BaP metabolism in the PBL obtained from psoriatic patients, treated in vitro with BaP. Our data did not show any significant influence of the CT treatment on the levels of PAH-DNA adducts. Moreover, the use of PBL from psoriatic patients, treated in vitro with BaP, did not allow to detect significant modifications of the metabolic activation of BaP and of the ability of its metabolites to bind to DNA, before and after CT treatment. Thus, PBL do not seem to represent an useful cell model to evaluate the possible genotoxic effect of the exposure through the skin of psoriatic patients to the PAH contained in CT. PMID:7698093

  20. Correlation of mutagenic potencies of various petroleum oils and oil coal tar mixtures with DNA adduct levels in vitro.

    PubMed

    Reddy, M V; Blackburn, G R; Schreiner, C A; Mackerer, C R

    1997-08-01

    An in vitro system was utilized to measure DNA adduct-forming ability of petroleum oils and oil coal tar mixtures to define correlations between DNA adduct levels and their mutagenic potencies. The system consisted of reaction of dimethyl sulfoxide extracts of oils with calf thymus DNA in the presence of Aroclor-induced hamster liver microsomes for 30 min. Following DNA extraction, DNA adducts were measured by the nuclease P1-enhanced postlabeling assay coupled with two-dimensional polyethyleneimine (PEI)-cellulose TLC. Thin layer plates showed putative aromatic DNA adducts, with levels ranging from 60 to 1400 adducts per 10(9) DNA nucleotides. TLC mobilities suggested adducts to be aromatic compounds containing 4 or more rings. A good correlation (coefficient of correlation = 0.91) was observed between DNA adduct levels and Salmonella mutagenicity for 19 oils. All 19 samples tested produced DNA adducts. To expedite the TLC procedure, adducts were resolved by one-dimensional TLC and the radioactivity measured using a mechanical scanner. Results were comparable to those obtained by two-dimensional TLC and quantification after scraping. Our data show that the in vitro incubation system coupled with the postlabeling adduct assay is a useful screening method to identify mutagenic and potentially carcinogenic oils.

  1. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, January--March 1993

    SciTech Connect

    Not Available

    1993-09-01

    Accomplishments for the past quarter are briefly described for the following areas of research: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale and tar sand researches cover processing studies. Coal research includes: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology covers: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW{sup TM} field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid-state NMR analysis of Mesaverde Group, Greater Green River Basin tight gas sands; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; oil field waste cleanup using tank bottom recovery process; remote chemical sensor development; in situ treatment of manufactured gas plant contaminated soils demonstration program; solid-state NMR analysis of naturally and artificially matured kerogens; and development of an effective method for the clean-up of natural gas.

  2. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, October--December 1992

    SciTech Connect

    Speight, J.G.

    1992-12-31

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  3. Topical tar: Back to the future

    SciTech Connect

    Paghdal, K.V.; Schwartz, R.A.

    2009-08-15

    The use of medicinal tar for dermatologic disorders dates back to the ancient times. Although coal tar is utilized more frequently in modern dermatology, wood tars have also been widely employed. Tar is used mainly in the treatment of chronic stable plaque psoriasis, scalp psoriasis, atopic dermatitis, and seborrheic dermatitis, either alone or in combination therapy with other medications, phototherapy, or both. Many modifications have been made to tar preparations to increase their acceptability, as some dislike its odor, messy application, and staining of clothing. One should consider a tried and true treatment with tar that has led to clearing of lesions and prolonged remission times. Occupational studies have demonstrated the carcinogenicity of tar; however, epidemiologic studies do not confirm similar outcomes when used topically. This article will review the pharmacology, formulations, efficacy, and adverse effects of crude coal tar and other tars in the treatment of selected dermatologic conditions.

  4. Determination of the Forms of Nitrogen Released in Coal Tar During Rapid Devolatilization. Semi-annual report, May 1-October 31, 1997

    SciTech Connect

    Fletcher, T.H., Goldberg, P.

    1997-10-31

    The primary objective of this work is to determine the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (104 to 105 K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. The forms of nitrogen in coal, char, and tar samples are analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-Ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques are being performed in collaboration with other researchers at BYU, the University of Utah, and industrial organizations. Coals have been obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HIPPS (High Performance Power Systems) and LEBS (Low- Emission Boiler Systems) programs. Anticipated results from the proposed research are (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HIPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  5. Biological monitoring as a useful tool for the detection of a coal-tar contamination in bitumen-exposed workers.

    PubMed

    Raulf-Heimsoth, Monika; Angerer, Jürgen; Pesch, Beate; Marczynski, Boleslaw; Hahn, Jens Uwe; Spickenheuer, Anne; Preuss, Ralf; Rühl, Reinhold; Rode, Peter; Brüning, Thomas

    2008-01-01

    In our research project entitled "Chemical irritative and/or genotoxic effect of fumes of bitumen under high processing temperatures on the airways," 73 mastic asphalt workers exposed to fumes of bitumen and 49 construction nonexposed workers were analyzed and compared with respect to polycyclic aromatic hydrocarbons (PAHs) exposure and exposure-related health effects. In order to assess the internal exposure the monohydroxylated metabolites of pyrene, 1- hydroxypyrene (1-OHP), and phenanthrene, 1-, 2- and 9-, and 3- and 4-hydroxyphenanthrene (OHPH) were determined in pre- and post-shift urinary samples. Significantly higher concentrations 1-OHP and OHPH were detected in the post-shift urine samples of 7 mastic asphalt workers working on the same construction site compared to the reference workers and all other 66 mastic asphalt workers. The adjusted mean OHPH in the reference, 66 mastic worker, and 7 worker subgroups was 1022, 1544, and 12919 ng/g creatinine (crn) respectively, indicating a marked rise in the 7 worker subgroup. In addition, there was a more than 12-fold increase of PAH metabolites from pre- to post-shift in these 7 workers, whereas in the other mastic asphalt workers there was only a twofold rise in PAH-metabolite concentration between pre- and post-shift values. The analysis of a drilling core from the construction site of the seven workers led to the detection of the source for this marked PAH exposure during the working shift as being coal tar plates, which were, without knowledge of the workers and coordinators, the underground material of the mastic asphalt layer. The evaluation of the stationary workplace concentration showed enhanced levels of phenanthrene, pyrene, fluorene, anthracene, and acenaphthene during working shifts at the construction site of these seven workers. Our study shows that biological monitoring is also a useful tool for the detection of unrecognized sources with high PAH concentrations.

  6. PAH concentration gradients and fluxes through sand cap test cells installed in situ over river sediments containing coal tar.

    PubMed

    Kim, Yong Sang; Nyberg, Leila M; Jenkinson, Byron; Jafvert, Chad T

    2013-08-01

    Short-term performance of permeable sand cap test cells, installed over sediment containing liquid coal tar was monitored on the Grand Calumet River (Hammond, Indiana, USA). The sand cap test cells included two sand-only cells, two test cells containing a sand/peat mixed layer, two test cells containing a sand/organoclay mixed layer, and two sediment control cells. In each test cell, six monocyclic and twelve polycyclic aromatic hydrocarbons (MAHs and PAHs) were monitored over an 18 month period, and interfacial water flow was monitored periodically. Seepage velocities ranged from 3.8 cm per day into the sediments to 3.2 cm per day out of the sediments, with discharge out of the sediments being observed more often. A ferric iron test indicated that stratified oxic-anaerobic layers were formed in the caps. Within the sand caps, concentrations of MAHs and PAHs fluctuated with time, and this fluctuation was more significant near the bottom. Near the top, most of the MAHs and PAHs were attenuated above 95% in the first year of the study, but their attenuation rates decreased in the second year due to recontamination of the surface of the caps by the surrounding sediments. Functional genes involved in PAH degradation were detected by polymerase chain reaction (PCR) in upper and lower sections of the caps for each of the three treatments. Bacterial communities were characterized by PCR amplification of 16s rRNA genes and denaturing gradient gel electrophoresis (DGGE). The results indicate that the rate and direction of sediment porewater flow is an important factor for properly designing any remedial sand cap, and that biodegradation of many of the MAH and PAH compounds was likely a major removal mechanism leading to attenuation through the test cells.

  7. Effects of temperature, pressure, and carrier gas on the cracking of coal tar over a char-dolomite mixtures and calcined dolomite in a fixed-bed reactor

    SciTech Connect

    Seshadri, K.; Shamsi, A.

    1998-10-01

    A distillation fraction of a coal-derived liquid (tar) was cracked over a char-dolomite mixture, calcined dolomite, and silicon carbide in a fixed-bed reactor. The char-dolomite mixture (FWC) was produced from Pittsburgh No. 8 coal and dolomite in a Foster Wheeler carbonizer. The experiments were conducted under nitrogen and simulated coal gas (SCG), which was a mixture of CO, CO{sub 2}, H{sub 2}S, CH{sub 4}, N{sub 2}, and steam, at 1 and 17 atm. The conversion over these materials under nitrogen was much higher at 17 atm than at 1 atm. At higher pressures, tar molecules were trapped in the pores of the bed material and underwent secondary reactions, resulting in the formation of excess char. However, when nitrogen was replaced by SCG, the reactions that induce char formation were suppressed, thus increasing the yield of gaseous products. The analysis of the gaseous products and the spent bed materials for organic and inorganic carbons suggested that the product distribution can be altered by changing the carrier gas, temperature, and pressure.

  8. Dandruff, seborrheic dermatitis, and psoriasis drug products containing coal tar and menthol for over-the-counter human use; amendment to the monograph. Final rule

    SciTech Connect

    2006-03-15

    The Food and Drug Administration (FDA) is issuing a final rule amending the final monograph (FM) for over-the-counter (OTC) dandruff, seborrheic dermatitis, and psoriasis drug products to include the combination of 1.8 percent coal tar solution and 1.5 percent menthol in a shampoo drug product to control dandruff. FDA did not receive any comments or data in response to its previously proposed rule to include this combination. This final rule is part of FDA's ongoing review of OTC drug products.

  9. Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil

    SciTech Connect

    Totsche, K.U.; Jann, S.; Kogel-Knabner, I.

    2007-05-15

    Mobile colloidal and suspended matter is likely to affect the mobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturated soil zone at contaminated sites. We studied the release of mobile particles and dissolved organic matter as a function of variable climatic boundary conditions, and their effect on the export of PAHs at a coal tar-contaminated site using zero-tension lysimeters. Seepage water samples were analyzed for dissolved organic carbon (DOC), pH, electrical conductivity, turbidity, and particles larger than 0.7 {mu}m. The 16 Environmental Protection Agency PAHs were analyzed in the filtrate < 0.7 m and in the particle fraction. Our results show that extended no-flow periods that are followed by high-intensity rain events, such as thunderstorms, promote the mobilization of particles in the size 0.7 to 200 m. Mobilization is enforced by extended drying during summer. High particle concentrations are also associated with freezing and thawing cycles followed by either rain or snowmelt events. The export of PAHs is strongly connected to the release of particles in the 0.7- to 200-{mu}m size fraction. During the 2-yr monitoring period, up to 0.418 {mu}g kg{sup -1} PAHs were mobilized in the. ltrate (< 0.7 m) while the eightfold mass, 3.36 {mu}g kg{sup -1}, was exported with the retentate (0.7-200 {mu}m). Equilibrium dissolution of PAHs and transport in the dissolved phase seem to be of minor importance for the materials studied. Extreme singular-release events occurred in January 2003 and January 2004, when up to 55 {mu}g L{sup -1} PAHs per one single seepage event were observed within the retentate. Freezing and thawing cycles affect the PAH source materials, that is, the remnants of the nonaqueous phase liquid (NAPL). High mechanical strain during freezing results in the formation of particles. At the onset of the thawing and following rain or snowmelt events, PAHs associated with these particles are then exported from the lysimeter.

  10. Retinoic acid antagonizes basal as well as coal tar and glucocorticoid-induced cytochrome P4501A1 expression in human skin.

    PubMed

    Li, X Y; Aström, A; Duell, E A; Qin, L; Griffiths, C E; Voorhees, J J

    1995-03-01

    Cytochrome P4501A1 is known to be expressed in skin and thus has been implicated in the pathogenesis of skin cancer due to certain environmental carcinogens. Retinoic acid (RA) has been used in chemoprevention of certain skin and other epithelial cancers. Therefore, we used Northern and Western analysis to determine the effect of externally applied RA on basal P4501A1 expression. RA reduced basal levels of P4501A1 mRNA and protein by 68 (n = 14, P = 0.005) and 75% (n = 7, P = 0.04) respectively. RA application also reduced basal levels of P4501A2 (another P4501A1 subfamily member) mRNA by 93% (n = 7, P = 0.001) as determined by reverse transcription-polymerase chain reaction. Interestingly, P4501A1 mRNA expression induced by coal tar or glucocorticoid (clobetasol) was reduced 46 (n = 10, P = 0.003) and 69% (n = 5, P < 0.05) respectively by RA co-application. Downregulation of basal P4501A1 expression and antagonism of coal tar mediated P4501A1 induction by RA may be a mechanism involved in chemo-prevention of skin and other epithelial cancer by RA.

  11. The influence of psoriatic plaques pretreatment with crude coal tar vs. petrolatum on the efficacy of narrow-band ultraviolet B: a half-vs.-half intra-individual double-blinded comparative study.

    PubMed

    Abdallah, Marwa A; El-Khateeb, Ekramy Ahmed; Abdel-Rahman, Shereen H

    2011-10-01

    The value of psoriatic plaques pretreatment with specific topical preparations in the setting of NB-ultraviolet-B (UVB) therapy is debatable. It may be clarified through a comparative assessment between crude coal tar and petrolatum as pretreatment candidates. A prospective study included 40 patients with plaque psoriasis undergoing NB-UVB therapy. We compared among three treatment regimens: NB-UVB alone (control group; n=20) as well as NB-UVB preceded by crude coal tar 3% on one side and petrolatum on the other side (cases group I and II; n=20). Tar and petrolatum were topically applied thrice/day the day before NB-UVB exposure. Applications were removed using olive oil directly before NB-UVB exposure. Regimens' frequency was thrice/week and the clinical outcome was assessed, through both psoriasis area and severity index (PASI) and physician global assessment (PGA) scores, at baseline and 3 months later. There were significant (P<0.01) decreases in both PASI and PGA scores in all the groups. In comparison with the controls, cases revealed significantly (P<0.05) higher improvement percentages in both PASI and PGA scores for both tar and petrolatum. This influence, through the PGA score, was significantly (P<0.05) in favor of petrolatum. The pretreatment of psoriatic plaques with either petrolatum or crude coal tar may enhance the therapeutic outcome of NB-UVB, which appeared to favor petrolatum. © 2011 John Wiley & Sons A/S.

  12. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, July--September 1992

    SciTech Connect

    Not Available

    1992-12-31

    Progress made in five research programs is described. The subtasks in oil shale study include oil shale process studies and unconventional applications and markets for western oil shale.The tar sand study is on recycle oil pyrolysis and extraction (ROPE) process. Four tasks are described in coal research: underground coal gasification; coal combustion; integrated coal processing concepts; and sold waste management. Advanced exploratory process technology includes: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research covers: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO{sub 2} HUFF-N-PUFF process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; shallow oil production using horizontal wells with enhanced oil recovery techniques; NMR analysis of sample from the ocean drilling program; and menu driven access to the WDEQ hydrologic data management system.

  13. Determination of the forms of nitrogen released in coal tar during rapid devolatilization. Semi-annual report, November 1, 1995--April 30, 1996

    SciTech Connect

    Fletcher, T.H.

    1996-04-30

    Control of emissions of nitrogen oxides (NO{sub x}) from coal combustion systems is becoming a major design and retrofit consideration. Most NO{sub x} in coal combustion systems comes from nitrogen in the fuel, rather than from nitrogen in the air. Practical emission control strategies include burner design strategies (e.g., low NO{sub x} burners), overfire air, reburning, selective non-catalytic reduction (SNCR) using reduction agents such as NH{sub 3} or urea, and selective catalytic reduction (SCR). The order listed also reflects the order of increasing costs for implementation. It is therefore most economically desirable to perform burner modifications to reduce NO{sub x} emissions rather than other control measures. Low-NO{sub x} burners work on the principle that devolatilized nitrogen species will form N{sub 2} rather than NO{sub x} under locally fuel-rich conditions with sufficient residence time at appropriate temperatures. The amount and form of nitrogen released during devolatilization influence the degree of NO{sub x} reduction attainable using burner design strategies for a given coal. Nitrogen in the char following devolatilization is released by heterogeneous oxidation, and may not be controlled by aerodynamic burner modifications. The objectives of this work are to perform detailed chemical measurements of the nitrogen in coal, tar, and char.

  14. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 1 -- Base program. Final report, October 1986--September 1993

    SciTech Connect

    Smith, V.E.

    1994-05-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  15. Optimization of {sup 1}H and {sup 13}C NMR methods for structural characterization of acetone and pyridine soluble/insoluble fractions of a coal tar pitch

    SciTech Connect

    Trevor J. Morgan; Anthe George; David B. Davis; Alan A. Herod; Rafael Kandiyoti

    2008-05-15

    {sup 1}H and {sup 13}C high-resolution liquid-state NMR methods were used for the quantitative characterization of different molecular weight fractions of a coal tar pitch (CTP). Three fractions were studied: pitch acetone solubles (PAS), pitch pyridine soluble-acetone insolubles (PPS), and pitch pyridine insolubles (PPI). Standard liquid-state NMR methods were modified and calibrated for use with undeuterated quinoline or undeuterated 1-methyl-2-pyrrolidinone (NMP) as the solvent. This made it possible to calculate the average structural parameters for the higher molecular weight (MW) fractions of the coal tar pitch. Quantitative comparisons of structural differences between the solubility-separated fractions of the pitch are reported. The aromaticity and the average number of aromatic rings per polynuclear aromatic structure were both found to decrease with increasing solubility. Similarly, pericondensed and all other quaternary carbon species were found to decrease with increasing solubility. This suggests that 'continental' type structures become more dominant as the solvent solubility of these coal derived fractions diminishes. The estimated average number of aromatic rings ranged from 1 to 2 rings in the PAS fraction, 4 to 21 rings in the PPS fraction, and 11 to 210 rings in the PPI fraction. These ring-numbers were directly related to the number average molecular mass (M{sub n}) assigned to the particular fraction in the average structural parameter (ASP) calculations. The lower-limit of the M{sub n} values was derived from the ASP calculations as 200, 450, and 6200 u for the PAS, PPS, and PPI fractions, respectively. 66 refs., 7 figs., 15 tabs.

  16. An Open Label Prospective Randomized Trial to Compare the Efficacy of Coal Tar-Salicylic Acid Ointment Versus Calcipotriol/Betamethasone Dipropionate Ointment in the Treatment of Limited Chronic Plaque Psoriasis

    PubMed Central

    Khandpur, Sujay; Sahni, Kanika

    2014-01-01

    Background: Chronic plaque psoriasis is a common papulosquamous skin disorder, for which a number of topical agents are being used including coal tar, topical steroids and more recently topical calcipotriol/betamethasone dipropionate. There is no study comparing purified coal tar preparation with calcipotriol/betamethasone dipropionate ointment in limited chronic plaque psoriasis. Aims and Objectives: A prospective randomized open label controlled trial to compare the efficacy and safety of topical application of coal tar-salicylic acid ointment with calcipotriol/betamethasone dipropionate ointment applied once at night for 12 weeks for the treatment of limited chronic plaque psoriasis. Materials and Methods: A total of 62 patients of limited chronic plaque psoriasis (body surface area <10%) were randomized into two treatment groups: Group A received topical application of 6% coal tar with 3% salicylic acid ointment and Group B received calcipotriol/betamethasone dipropionate, once at night for 12 weeks. Results were assessed based on psoriasis area severity index (PASI) scores and patient global assessment (PGA) at each visit. Results: Mean PASI was significantly lower at week 2 (P = 0.01) and week 4 follow-up (P = 0.05) and the mean reduction in PASI was significantly higher at week 2 (P = 0.02) with calcipotriol/betamethasone than coal tar-salicylic acid, but this difference was not sustained at subsequent follow-up visits. Similarly, PGA scores at weeks 2 and 4 were significantly lower with calcipotriol/betamethasone dipropionate ointment (P = 0.003 and P = 0.007 respectively). There was no significant difference in any parameter during subsequent follow-up visits or at the end of the treatment phase (12 weeks). Conclusion: Topical nightly application of calcipotriol/betamethasone dipropionate ointment leads to an initial, more rapid reduction in disease severity, but the overall outcome parameters are comparable in the two treatment groups. PMID:25484388

  17. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, April--June 1993

    SciTech Connect

    Not Available

    1993-09-01

    Progress made in five areas of research is described briefly. The subtask in oil shale research is on oil shale process studies. For tar sand the subtask reported is on process development. Coal research includes the following subtasks: Coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes the following: Advanced process concepts; advanced mitigation concepts; oil and gas technology. Jointly sponsored research includes: Organic and inorganic hazardous waste stabilization; CROW{sup TM} field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sup 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid-state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; characterization of petroleum residua; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process;NMR analysis of samples from the ocean drilling program; oil field waste cleanup using tank bottom recovery process; remote chemical sensor development; in situ treatment of manufactured gas plant contaminated soils demonstration program; solid-state NMR analysis of Mowry formation shale from different sedimentary basins; solid-state NMR analysis of naturally and artificially matured kerogens; and development of effective method for the clean-up of natural gas.

  18. Process for hydrogenation of hydrocarbon tars

    DOEpatents

    Dolbear, Geoffrey E.

    1978-07-18

    Hydrocarbon tars of high asphaltene content such as tars obtained from pyrolysis of coal are dissolved in a solvent formed from the hydrogenation of the coal tars, and the resultant mixture hydrogenated in the presence of a catalyst at a pressure from about 1500 to 5000 psig at a temperature from about 500.degree. F to about the critical temperature of the solvent to form a light hydrocarbon as a solvent for the tars. Hydrogen content is at least three times the amount of hydrogen consumed.

  19. Kentucky tar sand project

    SciTech Connect

    Kelley, M.N.; Jones, H.D. II; Lewis, F.W.

    1985-03-01

    Engineering details and pilot-plant results from a pioneering investigation based on a Kentucky tar-sand reserve are presented. The tar sand deposits of Kentucky are generally situated in the southeastern rim of the Illinois Basin along the southern boundary of the Western Coal Field region. In a recent study of US tar sand reserves, it was reported that over 3.4 billion barrels of oil are in Kentucky tar sand deposits alone. In the 22,000 acres, estimated reserves are over 100 million barrels of recoverable heavy oil. The oil-impregnated section of the deposit ranges in heavy oil content from five gallons per ton to over fifteen gallons per ton. The ore body is up to thirty-five feet thick and the overall stripping ratio for a commercial plant is estimated to be one cubic yard of undisturbed overburden material per ton of tar sand ore. A shovel and truck-type strip mining operation would be used to provide feedstock to the plant.

  20. Oxygen consumption and filtering rate of Daphnia Pulex after exposure to water-soluble fractions of naphthalene, phenanthrene, No. 2 fuel oil, and coal-tar creosote

    SciTech Connect

    Geiger, J.G.; Buikema, A.L.

    1981-12-01

    The effects of short-term exposure to water-soluble fractions (WSF) of naphthalene, phenanthrene, No. 2 fuel oil, and coal-tar creosote upon oxygen consumption and filtering rates of Daphnia pulex are examined. Approximately 60 young Daphnia were exposed to test solutions of LC20 and LC30 concentrations of WSF for at least three molt cycles. Oxygen consumption was determined by the azide modification of the Winkler Method (American Public Health Association et al. 1975). Algal counts were made for experimental and control bottles using an Electrozone electronic particle counter interfaced with a PDP-11 minicomputer. Filtering rates were computed and expressed as ml/Daphnia/day. Results indicate no significant differences in oxygen consumption rates. However, changes in filtering rates may be a sensitive indicator of sublethal stress. 3 tables (JMT)

  1. Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant

    SciTech Connect

    Venier, P.; Clonfero, E.; Cottica, D.; Gava, C.; Zordan, M.; Pozzoli, L.; Levis, A.G.

    1985-05-01

    The mutagenicity of urinary extracts and the excretion of PAH from workers occupationally exposed to coal tar pitch volatiles in an anode plant were analyzed. Mutagenicity of the urinary extracts was measured by means of the plate test using S. typhimurium strain TA 98. After concentration, hydrolysis and reduction of the urine samples, PAH levels were measured by high resolution gas chromatography/mass spectrometry. No significant difference was found in the mutagenicity of the urinary extracts of non-smokers occupationally exposed to PAH as compared with the controls. Low PAH concentrations were found in the urine of the exposed subjects, which lends further support to the negative results obtained with the Ames test. The increase of urinary PAH excretion, in relation to occupational exposure, was mainly due to the less mutagenic, low molecular weight compounds.

  2. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line.

    PubMed

    Kienzler, Aude; Mahler, Barbara J; Van Metre, Peter C; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-07-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    USGS Publications Warehouse

    Kienzler, Aude; Mahler, Barbara J.; Van Metre, Peter C.; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-01-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

  4. A proposed procedure for derivation of regulatory values for carcinogenic airborne polycyclic aromatic hydrocarbons (PAHs) based on coal tar pitch (CTP) volatiles.

    SciTech Connect

    Foureman, G.L.; Smith, R.L.

    1999-07-01

    A procedure for estimating upper bound lifetime human cancer risk from air levels of six common carcinogenic polycyclic aromatic hydrocarbons (PAHs), termed APAHs of concern, is proposed. These PAHs are benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-c,d)pyrene, and chrysene. In application, this proposed procedure would regard any given air level obtained for a APAH of concern to originate from a standard mixture of coal tar pitch (CTP). The given air level for the APAHs of concern is then related to a corresponding air level of CTP and thence, to an inhalation unit cancer risk calculated for CTP. Reference values for the procedure are the relative and absolute PAH composition of a CTP standard (SRM-1597) and the inhalation unit cancer risk. Qualitative characterization of the results are a vital part of the procedure especially when more than one APAH of concern{at} is being considered. Toxic equivalency factors (TEFs) may be used as an evaluative tool in characterization of the procedure and outcome. Limitations of this proposed procedure include the uneven database for the reference values and the inability to consider air samples inclusive of another common carcinogenic PAH, dibenz(a,h)anthracene, due to its lack of documentation in CTP and high TEF

  5. Laboratory differential simulation design method of pressure absorbers for carbonization of phenolate solution by carbon dioxide in coal-tar processing

    SciTech Connect

    Linek, V.; Sinkule, J.; Moucha, T.; Rejl, J.F.

    2009-01-15

    A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and toluene is added. These conditions have the following favourable effects: (I) significant size reduction of the columns, (ii) it is possible to process more concentrated solutions without danger of silting the columns by crystallization of NaHCO{sub 3} on the packing. (iii) small amount of inert gas is released, (iv) lower alkalinity and better separability of the organic phase (phenols with toluene) from water phase (soda or bicarbonate solution) in separators.

  6. Identification and Quantification of Six-Ring C26H16 Cata-Condensed Polycyclic Aromatic Hydrocarbons in a Complex Mixture of Polycyclic Aromatic Hydrocarbons from Coal Tar

    PubMed Central

    Oña-Ruales, Jorge O.; Sharma, Arun K.; Wise, Stephen A.

    2015-01-01

    We applied a combination of normal-phase liquid chromatography (NPLC) with ultraviolet-visible spectroscopy and gas chromatography with mass spectrometry (GC/MS) for the fractionation, identification, and quantification of six ring C26H16 cata-condensed polycyclic aromatic hydrocarbons, PAHs, in the Standard Reference Material 1597a, Complex Mixture of PAHs from Coal Tar. For the characterization analysis, we calculated the GC retention indices of 17 C26H16 PAH authentic reference standards using the Rxi-PAH and DB-5 GC columns. Then, we used NPLC with ultraviolet-visible spectroscopy to isolate the fractions containing the C26H16 PAHs, and subsequently, we used GC/MS to establish the identity and quantity of the C26H16 PAHs using authentic reference standards. Following this procedure, 12 C26H16 cata-condensed PAHs benzo[c]pentaphene, dibenzo[f,k]tetraphene, benzo[h]pentaphene, dibenzo[a,l]tetracene, dibenzo[c,k]tetraphene, naphtho[2,3-c]tetraphene, dibenzo[a,c]tetracene, benzo[b]picene, dibenzo[a,j]tetracene, naphtho[2,1-a]tetracene, dibenzo[c,p]chrysene, and dibenzo[a,f]tetraphene were identified and quantified for the first time, and benzo[c]picene was quantified for the first time in an environmental combustion sample. PMID:26449848

  7. Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by native microflora and combinations of white-rot fungi in a coal-tar contaminated soil.

    PubMed

    Canet, R; Birnstingl, J G; Malcolm, D G; Lopez-Real, J M; Beck, A J

    2001-01-01

    Four white-rot fungi (Phanerochaete chrysosporium IMI 232175, Pleurotus ostreatus from the University of Alberta Microfungus Collection IMI 341687, Coriolus versicolor IMI 210866 and Wye isolate #7) and all possible combinations of two or more of these fungi, were incubated in microcosms containing wheat straw and non-sterile coal-tar contaminated soil to determine their potential to degrade polycyclic aromatic hydrocarbons (PAHs). Biotic and abiotic controls were prepared similarly and PAH concentrations remaining in each microcosm were determined after 8, 16 and 32 weeks by GC-MS following extraction with dichloromethane. The greatest PAH losses were in the biotic control, compared to small or negligible differences in microcosms inoculated with one or more fungi. These results suggest that in the biotic control native microorganisms colonised the straw added as organic substrate and degraded PAH as an indirect consequence of their metabolism. By contrast, in other microcosms, colonisation of straw by the natural microflora was inhibited because the straw was previously inoculated with fungi. Soil cultures prepared at the end of the experiment showed that though introduced fungi were still alive, they were unable to thrive and degrade PAH in such a highly contaminated soil and remained in a metabolically inactive form.

  8. Assessment of intrinsic bioremediation of a coal-tar-affected aquifer using two-dimensional reactive transport and biogeochemical mass balance approaches

    SciTech Connect

    Rogers, S.W.; Ong, S.K.; Stenback, G.A.; Golchin, J.; Kjartanson, B.H.

    2007-01-15

    Expedited site characterization and groundwater monitoring using direct-push technology and conventional monitoring wells were conducted at a former manufactured gas plant site. Biogeochemical data and heterotrophic plate counts support the presence of microbially mediated remediation. By superimposing solutions of a two-dimensional reactive transport analytical model, first-order degradation rate coefficients (day{sup -1}) of various compounds for the dissolved-phase plume were estimated (i.e., benzene (0.0084), naphthalene (0.0058), and acenaphthene (0.0011)). The total mass transformed by aerobic respiration, nitrate reduction, and sulfate reduction around the free-phase coal-tar dense-nonaqueous-phase-liquid region and in the plume was estimated to be approximately 4.5 kg/y using a biogeochemical mass-balance approach. The total mass transformed using the degradation rate coefficients was estimated to be approximately 3.6 kg/y. Results showed that a simple two-dimensional analytical model and a biochemical mass balance with geochemical data from expedited site characterization can be useful for rapid estimation of mass-transformation rates.

  9. Removal and recovery of nitrogen and sulfur compounds from coal tar fractions using supported alminium sulfate under supercritical CO{sub 2} conditions

    SciTech Connect

    Sakanishi, K.; Obata, H.; Mochida, I.

    1994-12-31

    Removal and recovery of nitrogen and sulfur compounds from coal tar fractions such as crude naphthalene and methylnaphthalene oils are examined using 10 wt% Al{sub 2}(SO{sub 4}){sub 3}/SiO{sub 2} as a solid acid under atmospheric or supercritical CO{sub 2} (50{degrees}C, 80 atm) conditions. Repeated use of the solid acid is achieved by purging adsorbed nitrogen compounds with higher pressure (150 atm) CO{sub 2} and methanol as an entrainer solvent, recovering effectively quinoline bases as well as purifying methymaphthalenes. Benzothiophene (BT) is dimerized over Al{sub 2}(SO{sub 4}){sub 3}/SiO{sub 2} catalyst under supercritical CO{sub 2} conditions in order to separate BT from crude naphthalene as well as to purify naphthalene. BT was more selectively dimerized under supercritical CO{sub 2} conditions (100{degrees}C, 100 atm) than in atmospheric n-octane solution at 100{degrees}C, allowing its selective dimerization and adsorption on the solid acid with selective extraction of naphthalene. Effects of supercritical CO{sub 2} conditions on the above adsorptions and reactions are discussed based on the analysis of recovered fractions and products.

  10. ZnO template strategy for the synthesis of 3D interconnected graphene nanocapsules from coal tar pitch as supercapacitor electrode materials

    NASA Astrophysics Data System (ADS)

    He, Xiaojun; Li, Xiaojing; Ma, Hao; Han, Jiufeng; Zhang, Hao; Yu, Chang; Xiao, Nan; Qiu, Jieshan

    2017-02-01

    3D interconnected graphene nanocapsules (GNCs) were prepared from diverse aromatic hydrocarbons by a nano-ZnO-template strategy coupled with in-situ KOH activation technique. The as-made graphene networks feature thin carbonaceous shells with well-balanced micropores and mesopores. Such 3D porous networks provide freeways for good electron conduction, short pores for ion fast transport, and abundant micropores for ion adsorption. As the electrodes in supercapacitors, the unique 3D GNCs show a high capacitance of 277 F g-1 at 0.05 A g-1, a good rate performance of 194 F g-1 at 20 A g-1, and an excellent cycle stability with over 97.4% capacitance retention after 15000 cycles in 6 M KOH electrolyte. This synthesis strategy paves a universal way for mass production of 3D graphene materials from diverse aromatic hydrocarbon sources including coal tar pitch and petroleum pitch for high performance supercapacitors as well as support and sorbent.

  11. Investigation of organic matter dynamics during in-vessel composting of an aged coal-tar contaminated soil using fluorescence excitation-emission spectroscopy.

    PubMed

    Antízar-Ladislao, Blanca; Lopez-Real, Joe; Beck, Angus James

    2006-07-01

    In-vessel composting of an aged coal-tar contaminated soil from a manufactured gas plant site was investigated over 98days using laboratory-scale in-vessel composting reactors. The composting reactors were operated at 18 different operational conditions using a logistic three-factor factorial design with three temperatures (T=38, 55 and 70 degrees C), four soil to green waste ratios (S:GW; 0.6:1, 0.7:1, 0.8:1 and 0.9:1 on a dry weight basis) and three moisture contents (MC; 40%, 60% and 80%). Excitation-emission matrix (EEM) fluorescence spectroscopy was used to investigate organic matter dynamics in the composting mixture. The results of this investigation indicated that formation of humic substances can be monitored by fluorescence excitation-emission matrix, and provided evidence of progressive mineralization or humification of the composting mixture. Peak excitation wavelength shifts and peak fluorescence intensity can both be used as indicators to monitor the humification or maturation of compost. Finally, the fluorescence index can be applied to investigate the origin of humic substances and fulvic acids, and the humification or maturation of compost.

  12. Mortality and cancer experience of Quebec aluminum reduction plant workers. Part I: The reduction plants and coal tar pitch volatile (CTPV) exposure assessment

    SciTech Connect

    Lavoue, J.; Gerin, M.; Cote, J.; Lapointe, R.

    2007-09-15

    This paper presents the exposure assessment and job-exposure matrix (JEM) used to estimate coal tar pitch volatile (CTPV) exposure for a study of mortality and cancer incidence in aluminum smelter workers in Quebec, Canada. Historical CTPV exposure was assessed by estimating benzene-soluble material (BSM) and benzo(a)pyrene (B(a)P) levels for combinations of job and time period. Estimates were derived by using several procedures including averaging measurement data, a deterministic mathematical model using process-related correction factors, and expert-based extrapolation. The JEM comprised 28,910 jobs, covering 7 facilities from 1916 to 1999. Estimated exposures ranged from 0.01 {mu} g/m{sup 3} to 68.08 {mu} g/m{sup 3} (B(a)P) and 0.01 mg/m{sup 3} to 3.64 mg/m{sup 3} (BSW) and were lowest before 1940 and after 1980. This methodology constitutes an improvement compared with methods used for previous studies of the Quebec cohort.

  13. Recent government efforts regarding tar sands

    SciTech Connect

    Pumphrey, D.

    1980-12-01

    Conclusions from a workshop on tar sands are discussed. The workshop participants came to 3 conclusions: any oil-impregnated rock that is mined or quarried and then processed on the surface should be considered tar sands; some physical parameter should be used to differentiate tar sands from heavy oils, e.g., viscosity; and the dividing line between tar sands and heavy oil should be a point above which there is not currently significant commercial production. The resulting definition states that tar sand is any consolidated or unconsolidated rock other than coal, oil shale, or gilsonite, that contains a hydrocarbonaceous material with a gas-free viscosity, measured at reservoir temperature, greater than 10,000 cp, or contains a hydrocarbonaceous material that is extracted from the mined or quarried rock. Some consideration of resuming tar sands leasing also is discussed.

  14. Refining Lurgi tar acids

    SciTech Connect

    Greco, N.P.

    1984-04-17

    There is disclosed a process for removing tar bases and neutral oils from the Lurgi tar acids by treating the tar acids with aqueous sodium bisulfate to change the tar bases to salts and to hydrolyze the neutral oils to hydrolysis products and distilling the tar acids to obtain refined tar acid as the distillate while the tar base salts and neutral oil hydrolysis products remain as residue.

  15. Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

    SciTech Connect

    Mahadevan, B.; Marston, C.P.; Luch, A.; Dashwood, W.M.; Brooks, E.; Pereira, C.; Doehmer, J.; Baird, W.M.

    2007-03-15

    A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealed that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.

  16. DNA adducts in skin biopsies and 1-hydroxypyrene in urine of psoriasis patients and healthy volunteers following treatment with coal tar.

    PubMed

    Roelofzen, J H J; van der Valk, P G M; Godschalk, R; Dettbarn, G; Seidel, A; Golsteijn, L; Anzion, R; Aben, K K H; van Schooten, F J; Kiemeney, L A L M; Scheepers, P T J

    2012-08-13

    Coal tar ointments (CTO) are frequently used in the treatment of psoriasis and eczema, but CTO contain carcinogenic polycyclic aromatic hydrocarbons (PAH). PAH are absorbed and metabolized in the skin. In psoriasis, the skin barrier is altered and therefore, absorption and metabolism of PAH may differ from healthy skin. In this study, levels of urinary 1-hydroxypyrene and PAH-DNA adducts in the skin were studied in psoriatic patients and healthy volunteers. Three punch biopsies were taken from the lower back of 10 male volunteers and from a psoriatic plaque in 10 male patients. A surface of 6.25 cm(2) was treated with CTO. After 96 h CTO was removed and another three skin biopsies were collected from the treated area. DNA was isolated from skin biopsies and urine was collected during and after the exposure period. After 24h, a twofold lower 1-hydroxypyrene urinary excretion was observed in patients compared to healthy volunteers and after 48 h, this difference reached statistical significance (p<0.05). Over 96 h the median level of the sum of PAH-DNA adducts, analyzed by (32)P-post-labeling, increased from 3.5 before CTO administration to 21.1 adducts per 10(8) nucleotides in volunteers, and from 1.0 to 3.6 adducts per 10(8) nucleotides in patients. At 96 h, PAH-DNA levels were higher in healthy volunteers than in patients (p<0.05). Biomarkers for uptake, bioavailability and bioactivation of PAH were lower in patients compared to volunteers. These data suggest a lower risk of carcinogenic effects of CTO in psoriatic skin compared to healthy skin. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Abundance of Dioxygenase Genes Similar to Ralstonia sp. Strain U2 nagAc Is Correlated with Naphthalene Concentrations in Coal Tar-Contaminated Freshwater Sediments

    PubMed Central

    Dionisi, Hebe M.; Chewning, Christopher S.; Morgan, Katherine H.; Menn, Fu-Min; Easter, James P.; Sayler, Gary S.

    2004-01-01

    We designed a real-time PCR assay able to recognize dioxygenase large-subunit gene sequences with more than 90% similarity to the Ralstonia sp. strain U2 nagAc gene (nagAc-like gene sequences) in order to study the importance of organisms carrying these genes in the biodegradation of naphthalene. Sequencing of PCR products indicated that this real-time PCR assay was specific and able to detect a variety of nagAc-like gene sequences. One to 100 ng of contaminated-sediment total DNA in 25-μl reaction mixtures produced an amplification efficiency of 0.97 without evident PCR inhibition. The assay was applied to surficial freshwater sediment samples obtained in or in close proximity to a coal tar-contaminated Superfund site. Naphthalene concentrations in the analyzed samples varied between 0.18 and 106 mg/kg of dry weight sediment. The assay for nagAc-like sequences indicated the presence of (4.1 ± 0.7) × 103 to (2.9 ± 0.3) × 105 copies of nagAc-like dioxygenase genes per μg of DNA extracted from sediment samples. These values corresponded to (1.2 ± 0.6) × 105 to (5.4 ± 0.4) × 107 copies of this target per g of dry weight sediment when losses of DNA during extraction were taken into account. There was a positive correlation between naphthalene concentrations and nagAc-like gene copies per microgram of DNA (r = 0.89) and per gram of dry weight sediment (r = 0.77). These results provide evidence of the ecological significance of organisms carrying nagAc-like genes in the biodegradation of naphthalene. PMID:15240274

  18. Comparative quantitative prevalence of Mycobacteria and functionally abundant nidA, nahAc, and nagAc dioxygenase genes in coal tar contaminated sediments.

    PubMed

    Debruyn, Jennifer M; Chewning, Christopher S; Sayler, Gary S

    2007-08-01

    The Chattanooga Creek Superfund site is heavily contaminated with metals, pesticides, and coal tar with sediments exhibiting high concentrations of polycyclic aromatic hydrocarbons (PAHs). High molecular weight PAHs are of concern because of their toxicity and recalcitrance in the environment; as such, there is great interest in microbes, such as fast-growing Mycobacterium spp., capable of degradation of these compounds. Real-time quantitative PCR assays were developed targeting multiple dioxygenase genes to assess the ecology and functional diversity of PAH-degrading communities. These assays target the Mycobacterium nidA, beta-proteobacteria nagAc, and gamma-proteobacteria nahAc with the specific goal of testing the hypothesis that Mycobacteria catabolic genes are enriched and may be functionally associated with high molecular weight PAH biodegradation in Chattanooga Creek. Dioxygenase gene abundances were quantitatively compared to naphthalene and pyrene mineralization, and temporal and spatial PAH concentrations. nidA abundances ranged from 5.69 x 10(4) to 4.92 x 10(6) copies per gram sediment; nagAc from 2.42 x 10(3) to 1.21 x 10(7), and nahAc from below detection to 4.01 x 10(6) copies per gram sediment. There was a significantly greater abundance of nidA and nagAc at sites with the greatest concentrations of PAHs. In addition, nidA and nagAc were significantly positively correlated (r = 0.76), indicating a coexistence of organisms carrying these genes. A positive relationship was also observed between nidA and nagAc and pyrene mineralization indicating that these genes serve as biomarkers for pyrene degradation. A 16S rDNA clone library of fast-growing Mycobacteria indicated that the population is very diverse and likely plays an important role in attenuation of high molecular weight PAHs from Chattanooga Creek.

  19. Characterization and organic electric-double-layer-capacitor application of KOH activated coal-tar-pitch-based carbons: Effect of carbonization temperature

    NASA Astrophysics Data System (ADS)

    Choi, Poo Reum; Lee, Eunji; Kwon, Soon Hyung; Jung, Ji Chul; Kim, Myung-Soo

    2015-12-01

    The present study reports the influence of pre-carbonization on the properties of KOH-activated coal tar pitch (CTP). The change of crystallinity and pore structure of pre-carbonized CTPs as well as their activated carbons (ACs) as function of pre-carbonization temperature are investigated. The crystallinity of pre-carbonized CTPs increases with increasing the carbonization temperature up to 600 °C, but a disorder occurs during the carbonization around 700 °C and an order happens gradually with increasing the carbonization temperatures in range of 800-1000 °C. The CTPs pre-carbonized at high temperatures are more difficult to be activated with KOH than those pre-carbonized at low temperatures due to the increase of micro-crystalline size and the decrease of surface functional groups. The micro-pores and meso-pores are well developed at around 1.0 nm and 2.4 nm, respectively, as the ACs are pre-carbonized at temperatures of 500-600 °C, exhibiting high specific capacitances as electrode materials for electric double layer capacitor (EDLC). Although the specific surface area (SSA) and pore volume of ACs pre-carbonized at temperatures of 900-1000 °C are extraordinary low (non-porous) as compared to those of AC pre-carbonized at 600 °C, their specific capacitances are comparable to each other. The large specific capacitances with low SSA ACs can be attributed to the structural change resulting from the electrochemical activation during the 1st charge above 2.0 V.

  20. Comparative quantitative prevalence of mycobacteria and functionally abundant nidA, nahAc, and nagAc Dioxygenase genes in coal tar contaminated sediments

    SciTech Connect

    Jennifer M. DeBruyn; Christopher S. Chewning; Gary S. Sayler

    2007-08-01

    The Chattanooga Creek Superfund site is heavily contaminated with metals, pesticides, and coal tar with sediments exhibiting high concentrations of polycyclic aromatic hydrocarbons (PAHs). High molecular weight PAHs are of concern because of their toxicity and recalcitrance in the environment; as such, there is great interest in microbes, such as fast-growing Mycobacterium spp., capable of degradation of these compounds. Real-time quantitative PCR assays were developed targeting multiple dioxygenase genes to assess the ecology and functional diversity of PAH-degrading communities. These assays target the Mycobacterium nidA, {beta}-proteobacteria nagAc, and {gamma}-proteobacteria nahAc with the specific goal of testing the hypothesis that Mycobacteria catabolic genes are enriched and may be functionally associated with high molecular weight PAH biodegradation in Chattanooga Creek. Dioxygenase gene abundances were quantitatively compared to naphthalene and pyrene mineralization, and temporal and spatial PAH concentrations. nidA abundances ranged from 5.69 x 10{sup 4} to 4.92 x 10{sup 6} copies per gram sediment; nagAc from 2.42 x 10{sup 3} to 1.21 x 10{sup 7}, and nahAc from below detection to 4.01 x 10{sup 6} copies per gram sediment. There was a significantly greater abundance of nidA and nagAc at sites with the greatest concentrations of PAHs. In addition, nidA and nagAc were significantly positively correlated, indicating a coexistence of organisms carrying these genes. A positive relationship was also observed between nidA and nagAc and pyrene mineralization indicating that these genes serve as biomarkers for pyrene degradation. A 16S rDNA clone library of fast-growing Mycobacteria indicated that the population is very diverse and likely plays an important role in attenuation of high molecular weight PAHs from Chattanooga Creek. 35 refs., 5 figs., 1 tab.

  1. Tar sand

    SciTech Connect

    McLendon, T.R.; Bartke, T.C.

    1990-01-01

    Research on tar sand is briefly discussed. The research program supported by the US Department of Energy (DOE) includes a variety of surface extraction schemes. The University of Utah has process development units (PDU) employing fluidized bed, hot, water-assisted, and fluidized-bed/heat-pipe, coupled combustor technology. Considerable process variable test data have been gathered on these systems: (1) a rotary kiln unit has been built recently; (2) solvent extraction processing is being examined; and (3) an advanced hydrogenation upgrading scheme (hydropyrolysis) has been developed. The University of Arkansas, in collaboration with Diversified Petroleum, Inc., has been working on a fatty acid, solvent extraction process. Oleic acid is the solvent/surfactant. Solvent is recovered by adjusting processing fluid concentrations to separate without expensive operations. Western Research Institute has a PDU-scale scheme called the Recycle Oil Pyrolysis and Extraction (ROPE) process, which combines solvent (hot recycle bitumen) and pyrolytic extraction. 14 refs., 19 figs.

  2. Macrophages Facilitate Coal Tar Pitch Extract-Induced Tumorigenic Transformation of Human Bronchial Epithelial Cells Mediated by NF-κB

    PubMed Central

    Feng, Feifei; Wu, Yiming; Zhang, Shaofeng; Liu, Yu; Qin, Lijuan; Wu, Yongjun; Yan, Zhen; Wu, Weidong

    2012-01-01

    Objective Chronic respiratory inflammation has been associated with lung cancer. Tumor-associated macrophages (TAMs) play a critical role in the formation of inflammation microenvironment. We sought to characterize the role of TAMs in coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells and the underlying mechanisms. Methods The expression of TAMs-specific CD68 in lung cancer tissues and paired adjacent tissues from cancer patients was determined using immunostaining. Co-culture of human bronchial epithelial cells (BEAS-2B) and macrophage-like THP-1 cells were conducted to evaluate the promotive effect of macrophages on CTPE-induced tumorigenic transformation of BEAS-2B cells. BEAS-2B cells were first treated with 2.4 µg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured either with or without THP-1 cells and passaged using trypsin-EDTA. Alterations of cell cycle, karyotype, colony formation in soft agar and tumor xenograft growth in nude mice of BEAS-2B cells at passages 10, 20 and 30, indicative of tumorigenecity, were determined, respectively. In addition, mRNA and protein levels of NF-κB in BEAS-2B cells were measured with RT-PCR and western blot, respectively. B(a)P was used as the positive control. Results The over-expression of TAMs-specific CD68 around lung tumor tissues was detected and associated with lung cancer progression. The tumorigenic alterations of BEAS-2B cells including increase in cell growth rate, number of cells with aneuploidy, clonogenicity in soft agar, and tumor size in nude mice in vivo occurred at passage 10, becoming significant at passages 20 and 30 of the co-culture following CTPE removal in compared to BEAS-2B cells alone. In addition, the expression levels of NF-κB in BEAS-2B cells were positively correlated to the malignancy of BEAS-2B cells under different conditions of treatment. Conclusion The presence of macrophages facilitated CTPE

  3. Coal-Tar-Sealcoated Parking Lots: "Hot spots" of PAHs and N-heterocycles to Urban Streams and Lakes Result in "Hot Moments" of Toxicity

    NASA Astrophysics Data System (ADS)

    Mahler, B. J.; Van Metre, P. C.; Ingersoll, C.; Kunz, J. L.

    2014-12-01

    Coal-tar (CT) sealcoat, a potent source of polycyclic aromatic hydrocarbons (PAHs) and N-heterocycles, is applied to asphalt pavement of parking lots and driveways in many parts of the U.S. and Canada every 1 to 5 years. We measured the chemistry and toxicity of unfiltered runoff resulting from rain events simulated from 5 hours to 111 days after application of CT or asphalt (AS) sealcoat. PAHs and N-heterocycles were measured by GC/EIMS. Toxicity tests were done with Ceriodaphnia dubia and Pimephales promelas exposed 48 hours to undiluted and diluted (1 part runoff 9 parts control water) runoff under ambient lighting. Organisms were then transferred to fresh control water and subjected to a 4-hour pulse of ultraviolet radiation (UVR). Concentrations of 2- and 3-ringed PAHs and N-heterocycles in CT runoff, initially high (sum of 6 PAHs, 220 μg/L; sum of 7 N-heterocycles, 904 μg/L), decreased rapidly, whereas concentrations of 4-, 5- and 6-ringed PAHs more than doubled by 7 days after application (sum of 9 PAHs, 378 μg/L) and remained elevated 111 days after application (sum of 9 PAHs, 283 μg/L). Concentrations of PAHs and N-heterocycles in AS sealcoated runoff followed a similar pattern, but were ~10 times lower than those in CT runoff; concentrations in a sample of runoff from unsealed asphalt pavement were near or less than the detection limit. Organisms exposed to samples of undiluted CT-runoff collected during the 36 days following CT sealcoat application (no UVR exposure) experienced 100% mortality. Mortality (as much as 100%) of organisms exposed to the 10% dilution of CT runoff or to undiluted AS runoff occurred only with UVR; mortality of organisms exposed to the 10% solution of AS runoff and UVR was minimal. Results demonstrate that freshly CT-sealed parking lots and driveways are "hot spots" of PAH and N-heterocycle contamination and that prolonged "hot moments" of toxicity follow CT sealcoat application.

  4. The influence of different temperature programmes on the bioremediation of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated soil by in-vessel composting.

    PubMed

    Antizar-Ladislao, Blanca; Beck, Angus J; Spanova, Katarina; Lopez-Real, Joe; Russell, Nicholas J

    2007-06-01

    The biodegradation of 16 US. EPA-listed polycyclic aromatic hydrocarbons (sigma PAHs), with accompanying humification and microbial community structure changes during simulated in-vessel composting-bioremediation of an aged coal-tar-contaminated soil amended with green waste were studied over 56 days. The experimental design compared one constant temperature profile (TC=38 degrees C) with three variable temperature profiles (TP1, TP2 and TP3), including treatment at 70 degrees C to comply with regulatory requirements. Greatest sigma PAHs removal (75.4+/-0.1%; k(1)=0.026 day(-1), R(2)=0.98) occurred at TC=38 degrees C compared to all variable temperature profiles TP1 (62.1+/-11.0%; k(1)=0.016 day(-1), R(2)=0.93), TP2 (71.8+/-8.2%; k(1)=0.021 day(-1), R(2)=0.95) and TP3 (45.3+/-9.7%; k(1)=0.010 day(-1), R(2)=0.91). This study proved that using thermophilic temperatures (70 degrees C) towards the end of in-vessel composting processes (TP2) resulted in greater sigma PAHs removal than using other variable temperature profiles (TP1, TP3), as long as the increase was stepwise via an intermediate temperature (55 degrees C). Phospholipid fatty acid (PLFA) signatures indicated that use of thermophilic temperatures towards the end of the in-vessel composting-bioremediation (TP2) resulted in a higher fungal to bacterial PLFA ratio and a lower Gram-positive to Gram-negative (G(+)/G(-)) bacterial ratio. Fluorescence excitation-emission matrix (EEM) showed the presence of peaks typical of humic-like (Ex/Em wavelength pair approximately 340/460 nm) and fulvic-acid-like (Ex/Em wavelength pair approximately 245/460 nm) substances, indicating mineralization and/or maturation of the compost. Varying the temperature during in-vessel composting to comply with regulatory requirements for pathogen control, promoted contaminant biodegradation, microbial activity and compost maturation.

  5. Oxidative damage to nucleic acids and benzo(a)pyrene-7,8-diol-9,10-epoxide-DNA adducts and chromosomal aberration in children with psoriasis repeatedly exposed to crude coal tar ointment and UV radiation.

    PubMed

    Borska, Lenka; Andrys, Ctirad; Krejsek, Jan; Palicka, Vladimir; Chmelarova, Marcela; Hamakova, Kvetoslava; Kremlacek, Jan; Fiala, Zdenek

    2014-01-01

    The paper presents a prospective cohort study. Observed group was formed of children with plaque psoriasis (n=19) treated by Goeckerman therapy (GT). The study describes adverse (side) effects associated with application of GT (combined exposure of 3% crude coal tar ointment and UV radiation). After GT we found significantly increased markers of oxidative stress (8-hydroxy-2'-deoxyguanosine, 8-hydroxyguanosine, and 8-hydroxyguanine), significantly increased levels of benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) DNA adducts (BPDE-DNA), and significantly increased levels of total number of chromosomal aberrations in peripheral lymphocytes. We found significant relationship between (1) time of UV exposure and total number of aberrated cells and (2) daily topical application of 3% crude coal tar ointment (% of body surface) and level of BPDE-DNA adducts. The findings indicated increased hazard of oxidative stress and genotoxic effects related to the treatment. However, it must be noted that the oxidized guanine species and BPDE-DNA adducts also reflect individual variations in metabolic enzyme activity (different extent of bioactivation of benzo[a]pyrene to BPDE) and overall efficiency of DNA/RNA repair system. The study confirmed good effectiveness of the GT (significantly decreased PASI score).

  6. Advanced Thermally Stable Coal Based Jet Fuels

    DTIC Science & Technology

    2009-09-30

    commercially available so that tests could be run through pilot-plant scale were derivatives of coal tar from the metallurgical coke industry. The specific...end" for the coal-based jet fuel production. Options include direct liquefaction, tars from coal carbonization ( coking ), solvent extracts, coker...liquids from coking coal/petroleum blends, or by-product tars from fixed-bed coal gasification. Provided that any of these materials is suitably

  7. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 2 -- Jointly sponsored research program. Final report, October 1986--September 1993

    SciTech Connect

    Smith, V.E.

    1994-09-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  8. Process for detoxifying coal tars

    DOEpatents

    Longwell, John P.; Peters, William A.

    1983-01-01

    A process for treating liquid hydrocarbons to remove toxic, mutagenic and/or carcinogenic aromatic hydrocarbons comprises feeding the hydrocarbons into a reactor where vapors are thermally treated in contact with a catalyst consisting essentially of calcium oxide or a calcium oxide containing mineral. Thermally treating liquid hydrocarbons in contact with calcium oxide preferentially increases the cracking of aromatics thus producing a product having a reduced amount of aromatic compounds.

  9. Investigation of the rank dependence of tar evolution

    SciTech Connect

    Freihaut, J.D.; Proscia, W.M.

    1990-01-01

    The objectives of this study are to develop an improved understanding of the process of coal tar evolution, its relationship to the structural characteristics of the parent coal, and the dependence of the chemical and physical properties of the tar products on the conditions of devolatilization. Data from this study are expected to allow hypothesis testing and refinements of coal devolatilization models relevant to the pulverized coal combustion process. The program is divided into seven major technical areas: tar evolution rates in rapid heating conditions; molecular weight and vapor pressure characteristics of tars; chemical structure and calorific values of tars; influence of interphase mass transport phenomena; gas phase secondary reactions of primary'' tars; parent coal nitrogen evolution during devolatilization; and model hypothesis testing. A range of coal ranks, from a Texas lignite to a Pennsylvania anthracite, are employed in the investigation. In addition, a high temperature polymer, a polyimide, is utilized as an additional reference case. The polyimide serves as a truly polymeric reference material for examining the nitrogen evolution behavior of coal. The samples are subjected to elemental composition determination, infrared absorbance characteristics, calorific value, high temperature ash analysis, and maceral composition. Consideration is being given to NMR analysis as well as tetrahydrofuran (THF) solubility. Results are discussed. 4 refs., 27 figs., 4 tabs.

  10. Investigation of the rank dependence of tar evolution

    SciTech Connect

    Freihaut, J.D.; Proscia, W.M.

    1990-01-01

    The objective of this study are to develop an improved understanding of the process of coal tar evolution, its relationship to the structural characteristics of the parent coal, and the dependence of the chemical and physical properties of the tar products on the conditions of devolatilization. Data from this study are expected to allow hypothesis testing and refinements of coal devolatilization models relevant to the pulverized coal combustion process. A range of coal ranks, from a Texas lignite to a Pennsylvania anthracite, are employed in the investigation. In addition, a high temperature polymer, a polyimide, is utilized as an additional reference case. The polyimide serves as a truly polymeric reference material for examining the nitrogen evolution behavior of coal. The samples are subjected to elemental composition determination, infrared absorbance characterization, calorific value measurement, high temperature ash analysis, and maceral composition. Potential tar yields are determined by long hold time heated grid investigations of each coal at a final temperature and heating rate observed to maximize tar yields for the reference coal. Relative tar evolution kinetic behavior is determined by zero hold time heated grid investigations of each coal. 4 refs., 13 figs., 2 tabs.

  11. A coke oven model including thermal decomposition kinetics of tar

    SciTech Connect

    Munekane, Fuminori; Yamaguchi, Yukio; Tanioka, Seiichi

    1997-12-31

    A new one-dimensional coke oven model has been developed for simulating the amount and the characteristics of by-products such as tar and gas as well as coke. This model consists of both heat transfer and chemical kinetics including thermal decomposition of coal and tar. The chemical kinetics constants are obtained by estimation based on the results of experiments conducted to investigate the thermal decomposition of both coal and tar. The calculation results using the new model are in good agreement with experimental ones.

  12. Food Allergies

    MedlinePlus

    ... food allergy reactions: milk eggs peanuts soy wheat tree nuts (such as walnuts and cashews) fish shellfish ( ... peanut allergy and about 10% of kids with tree nut allergy outgrow their allergy. Fish and shellfish ...

  13. Food Allergies

    MedlinePlus

    ... de los dientes Video: Getting an X-ray Food Allergies KidsHealth > For Kids > Food Allergies Print A ... cow's milk eggs soy wheat What Is a Food Allergy? Food allergies happen when the immune system ...

  14. Coal: Its Structure and Some of Its Uses.

    ERIC Educational Resources Information Center

    Phillips, P. S.

    1981-01-01

    Describes the formation, chemical structure, and several uses of coal. The history of coal usage, production processes, coal tar products, and production of petroleum and other hydrocarbons from coal are also described. (DS)

  15. Coal: Its Structure and Some of Its Uses.

    ERIC Educational Resources Information Center

    Phillips, P. S.

    1981-01-01

    Describes the formation, chemical structure, and several uses of coal. The history of coal usage, production processes, coal tar products, and production of petroleum and other hydrocarbons from coal are also described. (DS)

  16. Environmental stability of PAH source indices in pyrogenic tars

    SciTech Connect

    Uhler, A.D.; Emsbo-Mattingly, S.D.

    2006-04-15

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants found in soil, sediments, and airborne particulates. The majority of PAHs found in modern soils and sediments arise from myriad anthropogenic petrogenic and pyrogenic sources. Tars and tar products such as creosote produced from the industrial pyrolysis of coal or oil at former manufactured gas plants (MGPs) or in coking retorts are viscous, oily substances that contain significant concentrations of PAH, usually in excess of 30% w/w. Pyrogenic tars and tar products have unique PAH patterns (source signatures) that are a function of their industrial production. Among pyrogenic materials, certain diagnostic ratios of environmentally recalcitrant 4-, 5- and 6-ring PAHs have been identified as useful environmental markers for tracking the signature of tars and petroleum in the environment. The use of selected PAH source ratios is based on the concept that PAHs with similar properties (i.e., molecular weight, partial pressure, solubility, partition coefficients, and biotic/abiotic degradation) will weather at similar rates in the environment thereby yielding stable ratios. The stability of more than 30 high molecular weight PAH ratios is evaluated during controlled studies of tar evaporation and aerobic biodegradation. The starting materials in these experiments consisted of relatively unweathered tars derived from coal and petroleum, respectively. The PAH ratios from these laboratory studies are compared to those measured in PAH residues found in tar-contaminated soils at a former MGP that operated with a carburetted water gas process.

  17. Latex Allergy

    MedlinePlus

    ... Allergic contact dermatitis. This reaction to the chemical additives used during manufacturing produces signs and symptoms — usually ... they're common in your family. Connection between food allergy and latex allergy Latex allergy also is ...

  18. Drug Allergy

    MedlinePlus

    ... Seizure Loss of consciousness Other conditions resulting from drug allergy Less common drug allergy reactions occur days ... occur the first time you take the drug. Drugs commonly linked to allergies Although any drug can ...

  19. Soy Allergy

    MedlinePlus

    ... Clinic Staff Allergy to soy, a product of soybeans, is a common food allergy. Often, soy allergy ... broth and vegetable starch Besides "soy," "soya" and "soybeans," other words on food labels may indicate that ...

  20. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: (1) Sales where the delivery is made by railroad car or cargo vessel. (2) Sales in a carload quantity... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use...

  1. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: (1) Sales where the delivery is made by railroad car or cargo vessel. (2) Sales in a carload quantity... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use...

  2. Coal.

    ERIC Educational Resources Information Center

    Brant, Russell A.; Glass, Gary B.

    1983-01-01

    Principle work of 23 state geological surveys is summarized. Work includes mapping/estimating coal resources, centralizing data in National Coal Resources Data System through cooperative programs, exploration drilling, and others. Comments on U.S. Geological Survey activities, coal-related conferences/meetings, and industry research activities are…

  3. Coal.

    ERIC Educational Resources Information Center

    Brant, Russell A.; Glass, Gary B.

    1983-01-01

    Principle work of 23 state geological surveys is summarized. Work includes mapping/estimating coal resources, centralizing data in National Coal Resources Data System through cooperative programs, exploration drilling, and others. Comments on U.S. Geological Survey activities, coal-related conferences/meetings, and industry research activities are…

  4. Topical pine tar: History, properties and use as a treatment for common skin conditions.

    PubMed

    Barnes, Tanya M; Greive, Kerryn A

    2016-01-20

    Pine tar is the end product of pine wood carbonisation following distillation using extreme heat. An extensive literature search was conducted back to the 1950s for this review. Pine tar has been used in medicine for more than 2000 years to treat a range of skin conditions because of its soothing and antiseptic properties. Pine tar should not be confused with coal tar, which has been produced from coal for approximately a hundred years. Pine tar is thought to exert its effect by reducing DNA synthesis and mitotic activity, which promotes a return to normal keratinisation. In addition, pine tar has been shown to be antipruritic, anti-inflammatory, antibacterial and antifungal. These properties make pine tar suitable for the topical treatment of eczema, psoriasis, seborrhoeic dermatitis and other dry, itchy, flaky or inflamed skin conditions. Topical products available over-the-counter in Australia today contain up to 2.3% pine tar, and come in several different formulations that can be used on the entire body, including the face. Modern day pine tar is manufactured with increased purity to eliminate toxic phenol and carcinogenic components, which have been of concern in the past. Primary irritation is uncommon. In conclusion, the long experience with topical pine tar therapy and its worldwide usage, together with the evidence presented in this review, suggests that pine tar is an effective treatment with minimal safety risk.

  5. Advanced Thermally Stable Coal-Based Jet Fuels

    DTIC Science & Technology

    2009-09-30

    through pilot-plant scale were derivatives of coal tar from the metallurgical coke industry. The specific coal tar product selected was refined...production. Options 3 include direct liquefaction, tars from coal carbonization ( coking ), solvent extracts, coker liquids from coking coal/petroleum...route was needed to obtain good yields of a product having the same chemical characteristics as refined chemical oil but one not requiring a coke

  6. Banded TARs in Iapygia

    NASA Image and Video Library

    2014-09-10

    The tropics of Mars are commonly littered with small bright ripples that were somehow shaped by the wind. NASA Mars Reconnaissance Orbiter might provide a valuable clue to the formation of transverse aeolian ridges TARs elsewhere on Mars.

  7. Comprehensive database of Manufactured Gas Plant tars. Part B. Aliphatic and aromatic compounds.

    PubMed

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were produced as a by-product from the manufactured gas and coke making industries. The composition of the tar produced varies depending on many factors; these include the temperature of production and the type of retort used. As different production processes produce different tars, a comprehensive database of the compounds present within coal tars from different production processes is a valuable resource. Such a database would help to understand how their chemical properties differ and what hazards the compounds present within these tars might pose. This study focuses on the aliphatic and aromatic compounds present in a database of 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 198 individual aliphatic and 951 individual aromatic compounds were detected within 16 tar samples produced by five different production processes. The polycyclic aromatic hydrocarbon (PAH) content of coal tars varies greatly depending on the production process used to obtain the tars and this is clearly demonstrated within the results. The aliphatic composition of the tars provided an important piece of analytical information that would have otherwise been missed with the detection of petrogenic compounds such as alkyl cyclohexanes. The aromatic compositions of the tar samples varied greatly between the different production processes investigated and useful analytical information was obtained about the individual production process groups. Alkyl cyclohexanes were detected in all samples from sites known to operate Carbureted Water Gas plants and not detected in

  8. Determination of high-molecular weight polycyclic aromatic hydrocarbons in high performance liquid chromatography fractions of coal tar standard reference material 1597a via solid-phase nanoextraction and laser-excited time-resolved Shpol'skii spectroscopy.

    PubMed

    Wilson, Walter B; Alfarhani, Bassam; Moore, Anthony F T; Bisson, Cristina; Wise, Stephen A; Campiglia, Andres D

    2016-02-01

    This article presents an alternative approach for the analysis of high molecular weight - polycyclic aromatic hydrocarbons (HMW-PAHs) with molecular mass 302 Da in complex environmental samples. This is not a trivial task due to the large number of molecular mass 302 Da isomers with very similar chromatographic elution times and similar, possibly even virtually identical, mass fragmentation patterns. The method presented here is based on 4.2K laser-excited time-resolved Shpol'skii spectroscopy, a high resolution spectroscopic technique with the appropriate selectivity for the unambiguous determination of PAHs with the same molecular mass. The potential of this approach is demonstrated here with the analysis of a coal tar standard reference material (SRM) 1597a. Liquid chromatography fractions were submitted to the spectroscopic analysis of five targeted isomers, namely dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, naphtho[2,3-a]pyrene and dibenzo[a,h]pyrene. Prior to analyte determination, the liquid chromatographic fractions were pre-concentrated with gold nanoparticles. Complete analysis was possible with microliters of chromatographic fractions and organic solvents. The limits of detection varied from 0.05 (dibenzo[a,l]pyrene) to 0.24 µg L(-1) (dibenzo[a,e]pyrene). The excellent analytical figures of merit associated to its non-destructive nature, which provides ample opportunity for further analysis with other instrumental methods, makes this approach an attractive alternative for the determination of PAH isomers in complex environmental samples.

  9. Identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons in a complex mixture of polycyclic aromatic hydrocarbons from coal tar.

    PubMed

    Oña-Ruales, Jorge O; Ruiz-Morales, Yosadara; Wise, Stephen A

    2016-04-15

    A methodology for the characterization of groups of polycyclic aromatic hydrocarbons (PAHs) using a combination of normal phase liquid chromatography with ultraviolet-visible spectroscopy (NPLC/UV-vis) and gas chromatography with mass spectrometry (GC/MS) was used for the identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons, PAHs, in standard reference material (SRM) 1597a, complex mixture of PAHs from coal tar. The NPLC/UV-vis isolated the fractions based on the number of aromatic carbons and the GC/MS allowed the identification and quantification of five of the nine C26H14 PAH isomers; naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene using a retention time comparison with authentic reference standards. For the other four benzenoid isomers with no available reference standards the following two approaches were used. First, the annellation theory was used to achieve the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene, and second, the elution distribution in the GC fractions was used to support the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene and to reach the tentative identifications of dibenzo[a,ghi]perylene, naphtho[7,8,1,2,3-pqrst]pentaphene, and anthra[2,1,9,8-opqra]naphthacene. It is the first time that naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene are quantified, and the first time that benzo[qr]naphtho[3,2,1,8-defg]chrysene is potentially identified, in any sample, in any context.

  10. Determination of high-molecular weight polycyclic aromatic hydrocarbons in high performance liquid chromatography fractions of coal tar standard reference material 1597a via solid-phase nanoextraction and laser-excited time-resolved Shpol'skii spectroscopy

    PubMed Central

    Wilson, Walter B.; Alfarhani, Bassam; Moore, Anthony F. T.; Bisson, Cristina; Wise, Stephen A.; Campiglia, Andres D.

    2016-01-01

    This article presents an alternative approach for the analysis of high molecular weight – polycyclic aromatic hydrocarbons (HMW-PAHs) with molecular mass 302 Da in complex environmental samples. This is not a trivial task due to the large number of molecular mass 302 Da isomers with very similar chromatographic elution times and similar, possibly even virtually identical, mass fragmentation patterns. The method presented here is based on 4.2 K laser-excited time-resolved Shpol'skii spectroscopy, a high resolution spectroscopic technique with the appropriate selectivity for the unambiguous determination of PAHs with the same molecular mass. The potential of this approach is demonstrated here with the analysis of a coal tar standard reference material (SRM) 1597a. Liquid chromatography fractions were submitted to the spectroscopic analysis of five targeted isomers, namely dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, naphtho[2,3-a]pyrene and dibenzo[a,h]pyrene. Prior to analyte determination, the liquid chromatographic fractions were pre-concentrated with gold nanoparticles. Complete analysis was possible with microliters of chromatographic fractions and organic solvents. The limits of detection varied from 0.05 (dibenzo[a,l]pyrene) to 0.24 μg L−1 (dibenzo[a,e]pyrene). The excellent analytical figures of merit associated to its non-destructive nature, which provides ample opportunity for further analysis with other instrumental methods, makes this approach an attractive alternative for the determination of PAH isomers in complex environmental samples. PMID:26653471

  11. Food Allergies

    MedlinePlus

    ... of food, most food allergies are caused by tree nuts, peanuts, milk, eggs, soy, wheat, fish and ... all do. People rarely outgrow allergies to peanuts, tree nuts, fish and shellfish QuestionsQuestions to Ask Your ...

  12. Mold Allergy

    MedlinePlus

    ... Albuterol in Schools Access to Medications Clean Air Climate and Health Epinephrine in Schools Healthy Settings Food ... Allergy Capitals Anaphylaxis in America Extreme Allergies and Climate Change Access to Pseudoephedrine Consensus Study on Food ...

  13. Milk Allergy

    MedlinePlus

    ... can cause anaphylaxis — a severe, life-threatening reaction. Avoidance is the primary treatment for milk allergy. Fortunately, ... the symptoms, such as allergy medication or milk avoidance? What, if anything, appears to worsen the symptoms? ...

  14. Allergies - overview

    MedlinePlus

    ... that are caused by allergies (such as asthma, hay fever, and eczema) may need other treatments. Medicines that ... shots are most effective when used to treat hay fever and insect sting allergies. They are not used ...

  15. Eye Allergies

    MedlinePlus

    ... Sep. 01, 2016 Eye allergies, also called allergic conjunctivitis, are quite common. They occur when the eyes ... can tear and burn. Unlike other kinds of conjunctivitis, eye allergies are not spread from person to ...

  16. Food Allergy

    MedlinePlus

    ... in allergy and immunology to epidemiological and observational studies to identify risk factors and to clinical trials that are testing new strategies to prevent and treat food allergy. Read on ...

  17. Kids with Food Allergies

    MedlinePlus

    ... Us Living With Food Allergies Allergens Peanut Allergy Tree Nut Allergy Milk Allergy Egg Allergy Soy Allergy ... Gluten Substitutions for Soy Substitutions for Peanuts and Tree Nuts Substitutions for Corn Menu Planning for the ...

  18. Food Allergy

    MedlinePlus

    ... the Library View All » Allergy-Free Recipes » Allergy-Free Play Dough Recipes » Anaphylaxis Action Plan » Anaphylaxis Wallet Card » ... D and Food Allergy » When Should Children and Adolescents Assume Responsibility for Self-Treatment of ... Free Zone » Peanut Free Zone » Information ...

  19. Extracting Oil From Tar Sands

    NASA Technical Reports Server (NTRS)

    Ford, L. B.; Daly, D.

    1984-01-01

    Recovery of oil from tar sands possible by batch process, using steam produced by solar heater. In extraction process, solar heater provides steam for heating solvent boiler. Boiling solvent removes oil from tar sands in Soxhlet extractor.

  20. EXPERIMENTAL PRODUCTION AND TRANSMISSION OF TAR SARCOMAS IN CHICKENS

    PubMed Central

    Murphy, James B.; Landsteiner, Karl

    1925-01-01

    Two spindle cell sarcomas have developed as the result, of injection of coal tar into induced embryomas in chickens. One of these, transplanted to other chickens for eleven generations, is highly invasive in character, and metastasizes freely. Attempts to transmit this neoplasm by a filtrate or desiccate of the tumor have failed of success. PMID:19869028

  1. Drying low rank coal and retarding spontaneous ignition

    SciTech Connect

    Bellow, E.J. Jr.; Bixel, J.C.; Heaney, W.F.; Yan, T.Y.

    1989-05-09

    A method is described of passivating and cooling heated dried coal comprising: (a) heating particulate coal to a temperature between about 190 and about 230/sup 0/F to dry to the desired level: and (b) coating the resulting heated particulate coal with an aqueous emulsion of a hydrocarbon selected from the group consisting of petroleum resid, light cycle oil, heavy cycle oil, clarified slurry oil, durene, asphaltenes, coal tar and coal tar pitch.

  2. Tar burns in the southwest.

    PubMed

    Schiller, W R

    1983-07-01

    The burns which result from contact of human skin with hot tar may be quite serious in proportion to the body surface area involved. Although tending toward partial thickness burns, patchy areas of full thickness skin loss are commonly observed. The use of petrolatum-based ointments on the burn initially to dissolve the tar into the dressings seems like the most efficient and humane method of tar removal. Subsequently, care of the wound is like that of any other burn. Tar burns involving greater than 10 per cent of the body surface area are likely to be the most serious and require intravenous fluid resuscitation. Many tar burns appear to be preventable.

  3. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse

    SciTech Connect

    Siddens, Lisbeth K.; Bunde, Kristi L.; Harper, Tod A.; McQuistan, Tammie J.; Löhr, Christiane V.; Bramer, Lisa M.; Waters, Katrina M.; Tilton, Susan C.; Krueger, Sharon K.; and others

    2015-09-01

    FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.

  4. Survey of European technology developments of SO/sub x//NO/sub x/ flue gas clean up for coal-fired boilers, also free piston stirling engines and coal tar burning diesel engines

    SciTech Connect

    Not Available

    1980-10-01

    In an effort to identify advanced RD and D projects as candidates for joint ventures and/or introduction to the US, European technology developments in the area of flue gas cleanup were surveyed. This survey covers both wet and dry scrubbers for coal-fired boilers and includes advanced systems for removal of SO/sub x/ or combined SO/sub x//NO/sub x/ removal. Information on lime/limestone scrubbers is limited to a tabulation of commercial sized installations. Emphasis is based on demonstrations and suggestions are provided as to why the particular projects are considered to be in advance of US technology. Areas of Europe covered are Austria, Belgium, Denmark, France, Germany, Italy, Netherlands, Norway and Sweden. With a lower priority, Austria, Spain, and Switzerland were screened for the existence of relevant work. This survey allows the following tentative conclusions: (1) the most relevant work is performed in Germany and Scandinavia (Denmark, Norway and Sweden). Work of some relevance was identified in the Netherlands and Italy; and (2) except for Germany, where FGD is applied commercially, no coal-fired lime/limestone scrubbers are operating commercially in the surveyed countries. (Outside Germany, the only operating lime/limestone scrubber is a 35 MW oil-fired unit in Stockholm). Four processes examined in Germany are described in some detail.

  5. Comprehensive database of Manufactured Gas Plant tars. Part A. Database.

    PubMed

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. Different manufacturing processes have resulted in the production of distinctly different tar compositions. This study presents a comprehensive database of compounds produced using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS), analysing 16 tar samples produced by five distinct production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 16 tar samples originating from five different production processes: Low Temperature Horizontal Retorts, Horizontal Retorts, Vertical Retorts, Carbureted Water Gas and Coke Ovens, were analysed. A total of 2369 unique compounds were detected with 948 aromatic compounds, 196 aliphatic compounds, 380 sulfur-containing compounds, 209 oxygen-containing compounds, 262 nitrogen-containing compounds and 15 mixed heterocycles. Derivatisation allowed the detection of 359 unique compounds, the majority in the form of hydroxylated polycyclic aromatic hydrocarbons, many of which would not have been detected without derivatisation. Of the 2369 unique compounds detected, 173 were found to be present within all samples. A unique comprehensive database of compounds detected within 16 tar samples from five different production processes was produced. The 173 compounds identified within every sample may be of particular importance from a regulatory standpoint. This initial study indicates that different production processes produce tars with different chemical signatures and it can be further expanded upon by in-depth analysis of the different compound

  6. Food Allergies.

    PubMed

    Grief, Samuel N

    2016-09-01

    Food allergies are common and seem to be increasing in prevalence. Preventive measures have become far more evident in the public arena (schools, camps, sports venues, and so forth). Evaluation and management of food allergies has evolved such that primary care practitioners may choose to provide initial diagnostic and treatment care or refer to allergists for similar care. Food allergies, once considered incurable, are now being diminished in intensity by new strategies.

  7. Food Allergy.

    PubMed

    Sathe, Shridhar K; Liu, Changqi; Zaffran, Valerie D

    2016-01-01

    Food allergy is receiving increased attention in recent years. Because there is currently no known cure for food allergy, avoiding the offending food is the best defense for sensitive individuals. Type I food allergy is mediated by food proteins, and thus, theoretically, any food protein is a potential allergen. Variability of an individual's immune system further complicates attempts to understand allergen-antibody interaction. In this article, we briefly review food allergy occurrence, prevalence, mechanisms, and detection. Efforts aimed at reducing/eliminating allergens through food processing are discussed. Future research needs are addressed.

  8. Drug allergies

    MedlinePlus

    Allergic reaction - drug (medication); Drug hypersensitivity; Medication hypersensitivity ... A drug allergy involves an immune response in the body that produces an allergic reaction to a medicine. The ...

  9. Allergy Skin Tests

    MedlinePlus

    ... allergic rhinitis) Allergic asthma Dermatitis (eczema) Food allergies Penicillin allergy Bee venom allergy Latex allergy Skin tests are ... may recommend this test to check for an allergy to insect venom or penicillin. Patch test Patch testing is generally done to ...

  10. Do Allergies Cause Asthma?

    MedlinePlus

    ... Healthy Habits for TV, Video Games, and the Internet Do Allergies Cause Asthma? ... Allergies Cause Asthma? Allergies don't cause asthma. But kids who have allergies , or a family history of allergies, are more likely to get asthma ...

  11. Characterization of acid tars.

    PubMed

    Leonard, Sunday A; Stegemann, Julia A; Roy, Amitava

    2010-03-15

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain. (c) 2009 Elsevier B.V. All rights reserved.

  12. Food allergy

    PubMed Central

    Watson, J. B. G.; Timmins, J.

    1979-01-01

    Two children with food allergy could not be successfully managed on dietary restriction alone. There was a good response to treatment with oral sodium cromoglycate but none to placebo treatment. The use of sodium cromoglycate in the management of food allergy should be studied further. PMID:105671

  13. Allergy shots

    MedlinePlus

    ... sensitivity Eczema , a skin condition that a dust mite allergy can make worse Allergy shots are effective for common allergens such as: Weed and tree pollen Grass Mold or fungus Animal dander Dust mites Insect stings Adults (including the older people) as ...

  14. Juniper tar poisoning.

    PubMed

    Koruk, Suda Tekin; Ozyilkan, Esin; Kaya, Pinar; Colak, Dilsen; Donderici, Omer; Cesaretli, Yildirim

    2005-01-01

    Juniper tar (cade oil) is distilled from the branches and wood of Juniperus oxycedrus. It contains etheric oils, triterpene and phenols, and is used for many purposes in folk medicine. A case is reported of a previously healthy man who ingested a spoonful of home-made extract of Juniperus oxycedrus. The poisoning caused fever, severe hypotension, renal failure, hepatotoxicity, and severe cutaneous burns on the face. After supportive and symptomatic treatment, the patient improved and was discharged in a good condition on the eleventh day.

  15. American College of Allergy, Asthma & Immunology

    MedlinePlus

    ... Why Anaphylaxis Types of Allergies: Ragweed Allergy Pine Tree Allergy Hives (Urticaria) Food Allergy Types of Food ... Fish Allergy Eosinophilic Esophagitis Egg Allergy Corn Allergy Tree Nut Allergy Food Allergy Diagnosis Food Allergy Avoidance ...

  16. Task 3.9 -- Catalytic tar cracking. Semi-annual report, January 1--June 30, 1995

    SciTech Connect

    Young, B.C.; Timpe, R.C.

    1995-12-31

    Tar produced in the gasification of coal is deleterious to the operation of downstream equipment including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure swing adsorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means to remove these tars from gas streams and, in the process, generate useful products, e.g., methane gas, which is crucial to the operation of molten carbonate fuel cells. The objectives of this project are to investigate whether gasification tars can be cracked by synthetic nickel-substituted micamontmorillonite, zeolite, or dolomite material; and whether the tars can be cracked selectively by these catalysts to produce a desired liquid and/or gas stream. Results to date are presented in the cited papers.

  17. Comprehensive database of Manufactured Gas Plant tars. Part C. Heterocyclic and hydroxylated polycyclic aromatic hydrocarbons.

    PubMed

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatized post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatized samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 865 heterocyclic compounds and 359 hydroxylated polycyclic aromatic hydrocarbons (PAHs) were detected in 16 tar samples produced by five different processes. The contents of both heterocyclic and hydroxylated PAHs varied greatly with the production process used, with the heterocyclic compounds giving information about the feedstock used. Of the 359 hydroxylated PAHs detected the majority would not have been be detected without the use of derivatization. Coal tars produced using different production processes and feedstocks yielded tars with significantly different heterocyclic and hydroxylated contents. The concentrations of the individual heterocyclic compounds varied greatly even within the different production processes and provided information about the feedstock used to produce the tars. The hydroxylated PAH content of the samples provided important analytical information that would otherwise not have been obtained without the use of derivatization and GCxGC/TOFMS. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Food allergy

    MedlinePlus

    ... people of all ages) Soy (mostly in children) Tree nuts (people of all ages) Wheat (people of ... Allergies to peanuts, tree nuts, and shellfish tend to last a lifetime. Avoiding the problem foods may be easy if the food is ...

  19. Latex Allergy

    MedlinePlus

    ... gloves are coated with cornstarch powder, latex protein particles can stick to the cornstarch and fly into ... removed frequently, the air may contain many latex particles. SymptomsWhat are the symptoms of latex allergy?Latex ...

  20. Fish Allergy

    MedlinePlus

    ... can react to touching fish or breathing in vapors from cooking fish. A fish allergy can cause ... hives red spots swelling a drop in blood pressure , causing lightheadedness or loss of consciousness Your child ...

  1. Shellfish Allergy

    MedlinePlus

    ... can react to touching shellfish or breathing in vapors from cooking shellfish. Shellfish allergy can develop at ... hives red spots swelling a drop in blood pressure causing lightheadedness or loss of consciousness Your child ...

  2. Allergy Testing

    MedlinePlus

    ... Academy of Allergy, Asthma & Immunology. All Rights Reserved. Legal Notices | Site Map | Contact Us Social navigation Facebook Twitter Mobile navigation Home Conditions & Treatments Education & Training Practice Resources About AAAAI Search navigation Find ...

  3. Sun Allergy

    MedlinePlus

    ... occurs on skin that has been exposed to sunlight. The most common form of sun allergy is ... have unusual, bothersome skin reactions after exposure to sunlight. For severe or persistent symptoms, you may need ...

  4. Shellfish Allergy

    MedlinePlus

    ... been diagnosed with a shellfish allergy, keep injectable epinephrine on hand in case of a severe reaction. ... mouth or throat or difficulty breathing, give the epinephrine auto-injector right away. Every second counts in ...

  5. Fish Allergy

    MedlinePlus

    ... been diagnosed with a fish allergy, keep injectable epinephrine on hand in case of a severe reaction. ... mouth or throat or difficulty breathing, give the epinephrine auto-injector right away. Every second counts in ...

  6. Egg Allergy

    MedlinePlus

    ... some people are allergic to certain foods, like peanuts or shrimp. When a person has a food ... are meat, poultry, fish, and legumes (beans and peanuts). If you have more than one food allergy, ...

  7. [Ocular allergies].

    PubMed

    Messmer, E M

    2005-05-01

    Recent developments indicate that ocular allergy is more than an IgE-mediated allergic conjunctivitis. Ocular allergy is a disease affecting the entire ocular surface including conjunctiva, lids, cornea, lacrimal gland and tear film. Besides an IgE-mediated reaction, a complex chronic inflammation is involved in the pathogenesis of many ocular allergies. According to their pathogenesis and clinical picture, ocular allergies are classified into mild forms, such as seasonal and perennial allergic conjunctivitis as well as giant papillary conjunctivitis, and chronic, potentially blinding forms such as atopic keratoconjunctivitis and vernal keratoconjunctivitis. New therapeutics act on the entire inflammatory process or try to modulate the allergic reaction early and specifically. The association with non-ocular allergic symptoms requires an interdisciplinary approach.

  8. Penicillin Allergy

    MedlinePlus

    ... reactions cannot be detected by skin tests. Graded challenge If the diagnosis of a penicillin allergy is ... he or she may recommend a graded drug challenge. With this procedure, you receive four to five ...

  9. Kiwifruit allergies.

    PubMed

    Bublin, Merima

    2013-01-01

    While kiwifruit has a high nutritive and health value, a small proportion of the world's population appears to be allergic to the fruit. IgE-mediated kiwifruit allergy is often associated with birch and grass pollinosis as well as with latex allergy. Isolated allergy to kiwifruit is also relatively common and often severe. Eleven green kiwifruit (Actinidia deliciosa cv. Hayward) allergens recognized to date are termed as Act d 1 through Act d 11. Bet v 1 homologue (Act d 8) and profilin (Act d 9) are important allergens in polysensitized subjects, whereas actinidin (Act d 1) is important in kiwifruit monosensitized subjects. Differences in allergenicity have been found among kiwifruit cultivars. Allergy sufferers might benefit from the selection and breeding of low-allergenic kiwifruit cultivars.

  10. [Peanut allergy].

    PubMed

    Turcanu, Victor

    2010-01-01

    Peanut allergy currently affects around 1% of the UK and US paediatric population and represents a major healthcare concern because it is outgrown in less than 20% of cases and is a major cause of anaphylaxis. Its main symptoms, triggered by peanut ingestion, are cutaneous (urticaria, erythema, angioedema), gastrointestinal (abdominal pain, vomiting, diarrhoea), respiratory (wheezing, dyspnoea) and cardiovascular (hypotension, arrhythmia, shock). The usual onset of symptoms occurs soon after peanut ingestion (minutes to hours); however some patients have biphasic reactions, with exacerbations occurring up to 8 hours later. Peanut allergy diagnostic is based mainly upon the medical history (preferably including a diet diary and elimination diets), skin testing, peanut-specific IgE measurement and ideally a peanut oral challenge. Peanut allergy management includes monitorisation and education for avoiding peanut-containing foods and for recognising and treating anaphylactic episodes (self-injectable adrenalin and rapid-acting antihistamines). In the past, anti-IgE antibodies were shown to decrease the risk of anaphylaxis by reducing the allergic patients' reactivity to peanuts. Recent investigations, driven by the need to develop efficient treatment and prevention strategies for peanut allergy, suggest that oral immunotherapy with peanuts, although exposing the patients to significant risk, may represent a promising therapeutic approach. Furthermore, contrary to the general view that peanut avoidance in infants could prevent peanut allergy, a recent study shows that the opposite may be true as early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy.

  11. Medication/Drug Allergy

    MedlinePlus

    ... Science Education & Training Home Conditions Medication/Drug Allergy Medication/Drug Allergy Make an Appointment Find a Doctor ... immediate or delayed. What Is an Allergy to Medication/Drugs? Allergies to drugs/medications are complicated, because ...

  12. Asthma and allergy - resources

    MedlinePlus

    Resources - asthma and allergy ... The following organizations are good resources for information on asthma and allergies : Allergy and Asthma Network -- www.allergyasthmanetwork.org American Academy of Allergy Asthma and Immunology -- www. ...

  13. Relationship Between the Composition and Interfacial Tension of Former Manufactured Gas Plant Tars

    NASA Astrophysics Data System (ADS)

    Hauswirth, S.; Birak, P. S.; Miller, C. T.

    2011-12-01

    Former manufactured gas plant (FMGP) tars pose significant environmental hazards and present a challenge to regulators and industry professionals. The tars, which were produced as a byproduct of the gas manufacturing process, were frequently released into the environment through improper disposal or leaks in plant infrastructure. The interfacial tension (IFT) is a primary factor controlling the mobility of tars in porous media, and is therefore important to understand for both predicting the migration of tars and designing remediation strategies. In this study, we characterized nine field-collected FMGP tars and a commercially available coal tar by means of chemical extractions (asphaltenes, resins, acids, and bases), gas chromatography-mass spectrometry (GC-MS), and Fourier transform infrared (FTIR) spectroscopy. Additionally, the IFT and contact angle of each tar was determined for a pH range of 3-11. The IFT was found to be similar for all tars at pH 5 and 7 regardless of composition. Slight decreases in IFT at lower pH were correlated with higher concentrations of extractable bases, which consisted primarily of nitrogen-containing heterocyclic aromatic compounds. Much greater reductions of IFT were observed at high pH. These reductions were found to be associated with the presence of carbonyl or carboxyl groups in the asphaltenes. It is likely that the larger size of the asphaltene molecules (as compared to the extractable compounds) resulted in species with greater surface activity when ionized.

  14. TAR syndrome with orofacial clefting.

    PubMed

    Midro, A; Hubert, E; Preferansow, J; Iwaszkiewicz-Pawłowska, A

    1993-01-01

    A case of TAR syndrome with bilateral cleft lip and palate is presented. Bilateral symmetric focomelia, normal thumbs among five fingers of hands, synostosis of IVth and Vth metacarpal bones and some defects of lower limbs with associated thrombocytopenia were noted. Dysmorphic facial features included hypertelorism, epicanthus, blue sclerae, broad nasal root, micrognathia, low-set ears, sparse blond hair. To our knowledge this patient represents an unusual association of TAR syndrome with orofacial clefting. A common background of TAR and Roberts/SC syndrome is suggested.

  15. Latex allergy.

    PubMed

    Gawchik, Sandra M

    2011-01-01

    Allergy to natural rubber latex is an important clinical condition that occurred after the institution of universal precautions to protect healthcare workers. A rapid increase and production of both examination and surgical gloves resulted in an epidemic of allergy to latex protein. Healthcare workers in both the medical and dental environments, as well as specific groups of individuals including those with spina bifida, myelodysplasia, and food allergies (banana, kiwi, avocado, and others), were at increased risk of sensitization. Clinical symptoms in the latex allergic individual ranged from type I hypersensitivity reaction including rhinoconjunctivitis, asthma, and systemic reaction to type IV hypersensitivity reaction, which occur from the chemicals added during the manufacturing process. Diagnosis of latex allergy is based on a clinical history that correlates the development of symptoms in relationship to exposure. In the United States there are no skin tests approved by the Food and Drug Administration. Therefore a combination of clinical judgment and serologic testing such as ImmunoCAP and Immulite is helpful. The primary treatment of latex allergy is avoidance of exposure to the latex protein.

  16. Macrolides allergy.

    PubMed

    Araújo, Luis; Demoly, Pascal

    2008-01-01

    Macrolides are characterised by their basic structure which is made up of a lactonic cycle with 2 osidic chains. They are classified according to the number of carbon atoms in the cycle : 14 membered macrolides (erythromicin, roxithromycin, dirithromycin, clarithromycin), 15 membered (azithromycin) and 16 membered (spiramycin, josamycin, midecamycin) macrolides. Epidemiological studies show that macrolides are amongst the safest antibiotics, but in these series, no drug allergy work up was performed. An immediate IgE dependent hypersensitivity has been shown with erythromycin in some cases. The mechanism is unknown and the skin tests are negative in most other cases. It would appear that the macrolide allergies are unlikely to be class allergies. Eviction is the treatment of choice. Desensitization has been successful in a few cases.

  17. [Drug allergy].

    PubMed

    Pichler, W J

    1994-01-01

    Drug allergies can cause a great variety of symptoms and can thus imitate various diseases, like in previous times the lues. Drug allergies can be classified into three subgroups, which differ in their pathophysiology and require different diagnostic steps: firstly, classical drug allergies which are directed to the drug itself, a reactive compound of it or some contamination of the drug; secondly, pseudoallergic reactions which are caused by nonimmune mediated degranulation of mast cells and basophils; and thirdly, autoimmune reactions in which the drug elicits an immune reaction to autologous structures. A very detailed (criminalistic) history has the highest priority for the clarification of a suspected drug-allergic reaction; in addition, skin tests, serological tests and the lymphocyte transformation test might be useful. One should differentiate between tests which imitate the drug-elicited allergic reaction (i.e. Coombs test in drug induced hemolytic anemia) and tests which solely indicate a sensitization, these tests should be interpreted accordingly.

  18. [Respiratory allergies].

    PubMed

    Chiriac, Anca Mirela; Demoly, Pascal

    2013-04-01

    Respiratory allergies represent a global and public health problem, due to their prevalence (still increasing), morbidity, impact on the quality of life and costs for the society. They mainly concern rhinitis (or rhinoconjunctivitis) and asthma. The diagnosis of allergy is dependent on a history of symptoms on exposure to an allergen together with the detection of allergen-specific IgE. Accurate diagnosis of allergies opens up therapeutic options that are otherwise not appropriate, such as allergen immunotherapy and allergen avoidance, that are prescribed following a stepwise approach. It has been a century since the first trial in specific immunotherapy was performed and this still remains the only disease modifying treatment for allergic individuals. In terms of route of administration, sublingual immunotherapy represents a good alternative to subcutaneous immunotherapy, considering its proven efficacy and better safety profile.

  19. Braided TARs in Syrtis Major

    NASA Image and Video Library

    2014-12-03

    Transverse aeolian ridges TARs are commonly found throughout the Martian tropics, including rocky regions such as Syrtis Major that are largely devoid of dust as seen by NASA Mars Reconnaissance Orbiter.

  20. Shellfish Allergy

    MedlinePlus

    ... on the Food Allergy Research and Education website. Reading Food Labels Makers of foods sold in the ... outside of KidsHealth's control. About TeensHealth Nemours.org Reading BrightStart! Contact Us Partners Editorial Policy Privacy Policy & ...

  1. Food Allergies

    MedlinePlus

    ... delicious dessert, but then you see the crushed peanuts on top. Darn! You're allergic to peanuts. Maybe just one little bite? Nope. If you ... alone. These foods cause the most food allergies: peanuts and other nuts seafood, such as shrimp milk, ...

  2. Investigation of the rank dependence of tar evolution

    SciTech Connect

    Freihaut, J.D.; Proscia, W.M.

    1990-01-01

    Despite its high nitrogen concentration levels relative to the parent coal samples, 7.2% vs. 1.4 - 2.0%, little volatile nitrogen evolution is observed until decomposition temperatures of 600[degree]C or greater are obtained. Due to the lack of decomposition via tar evolution and as contrasted to parent coals, no significant bound nitrogen is evolved with heavy hydrocarbons at particle temperatures less than 600[degree]C. Similar to virgin'' chars and tars formed during rapid devolatilization, the polyimide samples begin to evolve significant fractions of bound nitrogen as IR-active light gases at particle temperatures between 650 and 750[degree]C. Unlike coal samples, however, relatively large fractions of the light gases are observed to be ammonia. The IR-active, nitrogen-containing light gas evolution rapidly declines at polyimide char temperatures greater than 750[degree]C, again in contrast to observed behavior in virgin coal char samples. It is not certain if the nitrogen evolution kinetics changes from selectively forming ammonia and hydrogen cyanide to benzonitriles or free nitrogen at these temperatures. The light gas evolution pattern with decomposition temperature of polymide could contribute to our understanding of the low conversion efficiencies observed for bound nitrogen to NO[sub x] conversion in the char combustion phase of pfc combustion.

  3. Investigation of the devolatilization of coal under combustion conditions. Seventh quarterly report, 1 April-30 June, 1980

    SciTech Connect

    Seery, D.J.

    1980-04-01

    This report describes progress during the seventh quarter of a two year contract to study pyrolysis of coal under combustion conditions. Major accomplishments of this quarter have been the infrared analysis of two new coals, heated grid devolatilization of these coals over the entire available temperature range, quantitative measurements of tar and char nitrogen contents, measurements of NO formation during early phase of combustion of coal, high speed photography of tar release from a Pittsburgh bituminous coal, relating the early tar release of the bituminous coal to its voltatiles combustion behavior.

  4. Impact of Asphaltenes and Resins on the Wetting Characteristics of Tars at Former Manufactured Gas Plants

    NASA Astrophysics Data System (ADS)

    Hauswirth, S. C.; Birak, P. S.; Rylander, S.; Pedit, J. A.; Miller, C. T.

    2008-12-01

    Tars produced as a byproduct of coal and oil gasification at manufactured gas plants (MGPs) during the 19th and early 20th centuries were often released into the environment through poor disposal practices or leaks in holding tanks and piping. These tars are persistent contaminants, leaching polycyclic aromatic hydrocarbons (PAHs) into groundwater and posing a significant risk to human and ecological health. MGP tars also have several properties that make them notoriously difficult to remediate. They are denser than water, so they can migrate to depths which make direct removal difficult or impossible, and their relatively high viscosities and ability to alter the wetting characteristics of porous media result in inefficient removal by traditional pump-and-treat methods. In this study, we investigate the last of these properties. Previous studies have linked wetting changes to asphaltenes---polar, high molecular weight compounds present in the tars. However, we have conducted qualitative bottle tests for tar samples collected from two former MGPs which indicate that there is no direct correlation between asphaltene concentration and the tendency to alter wetting characteristics of porous media. To better understand the factors controlling wetting behavior, we isolate asphaltenes and resins, another class of polar compounds, from a tar sample and recombine them with the remaining PAH mixture to create a series of tars of varying composition. We assess the relative impact of each of the fractions on wettability through contact angle measurements conducted at three different pHs.

  5. [Study on Microwave Co-Pyrolysis of Low Rank Coal and Circulating Coal Gas].

    PubMed

    Zhou, Jun; Yang, Zhe; Liu, Xiao-feng; Wu, Lei; Tian, Yu-hong; Zhao, Xi-cheng

    2016-02-01

    The pyrolysis of low rank coal to produce bluecoke, coal tar and gas is considered to be the optimal method to realize its clean and efficient utilization. However, the current mainstream pyrolysis production technology generally has a certain particle size requirements for raw coal, resulting in lower yield and poorer quality of coal tar, lower content of effective components in coal gas such as H₂, CH₄, CO, etc. To further improve the yield of coal tar obtained from the pyrolysis of low rank coal and explore systematically the effect of microwave power, pyrolysis time and particle size of coal samples on the yield and composition of microwave pyrolysis products of low rank coal through the analysis and characterization of products with FTIR and GC-MS, introducing microwave pyrolysis of low rank coal into the microwave pyrolysis reactor circularly was suggested to carry out the co-pyrolysis experiment of the low rank coal and coal gas generated by the pyrolysis of low rank coal. The results indicated that the yield of the bluecoke and liquid products were up to 62.2% and 26.8% respectively when the optimal pyrolysis process conditions with the microwave power of 800W, pyrolysis time of 40 min, coal samples particle size of 5-10 mm and circulating coal gas flow rate of 0.4 L · min⁻¹ were selected. The infrared spectrogram of the bluecoke under different microwave power and pyrolysis time overlapped roughly. The content of functional groups with -OH, C==O, C==C and C−O from the bluecoke through the pyrolysis of particle size coal samples had a larger difference. To improve microwave power, prolonging pyrolysis time and reducing particle size of coal samples were conducive to converting heavy component to light one into coal tar.

  6. Bioventing PAH contamination at the Reilly Tar Site

    SciTech Connect

    Alleman, B.C.; Hinchee, R.E.; Brenner, R.C.; McCauley, P.T.

    1995-12-31

    A pilot-scale bioventing demonstration has been in progress since November 1992 to determine if bioventing is an effective remediation treatment for polycyclic aromatic hydrocarbons (PAHs). The Reilly Tar and Chemical Corporation site in St. Louis Park, Minnesota, was selected for this demonstration. The location is the site of a former coal tar refinery and wood-preserving facility at which creosote in mineral oil served as the primary preservative. The goal of the project is to achieve 10% greater PAH removal over background degradation for each year of the 3-year study. Respiration measurements were made to estimate PAH biodegradation as a means of monitoring the progress of the technology. These measurements indicated that 13.4% and 17.3% degradation of the total PAH was possible during the first year and second year, respectively. Although not all of the respiration can be attributed conclusively to PAH metabolism, strong correlations were found between the PAH concentration and biodegradation rates.

  7. Nut and Peanut Allergy

    MedlinePlus

    ... Video: Getting an X-ray Nut and Peanut Allergy KidsHealth > For Kids > Nut and Peanut Allergy Print ... previous continue How Is a Nut or Peanut Allergy Diagnosed? If your doctor thinks you might have ...

  8. Allergy Shots (For Parents)

    MedlinePlus

    ... 5 years old. Allergy shots, which are given year-round, work better against some substances than others. Generally, ... peak allergy season. But many kids battle allergies year-round, and some can't control their symptoms with ...

  9. Do Allergies Cause Asthma?

    MedlinePlus

    ... or Too Short All About Puberty Do Allergies Cause Asthma? KidsHealth > For Kids > Do Allergies Cause Asthma? ... a tight feeling in the chest. Do Allergies Cause YOUR Asthma? If you have asthma, it's a ...

  10. Nut and Peanut Allergy

    MedlinePlus

    ... What Happens in the Operating Room? Nut and Peanut Allergy KidsHealth > For Kids > Nut and Peanut Allergy ... worse. previous continue How Is a Nut or Peanut Allergy Diagnosed? If your doctor thinks you might ...

  11. Allergy testing - skin

    MedlinePlus

    ... may order allergy skin tests if you have: Hay fever ( allergic rhinitis ) and asthma symptoms that are not ... team. Related MedlinePlus Health Topics Allergy Food Allergy Hay Fever Browse the Encyclopedia A.D.A.M., Inc. ...

  12. Treating tar sands formations with karsted zones

    SciTech Connect

    Vinegar, Harold J.; Karanikas, John Michael

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  13. Environmental benefits of underground coal gasification.

    PubMed

    Liu, Shu-qin; Liu, Jun-hua; Yu, Li

    2002-04-01

    Environmental benefits of underground coal gasification are evaluated. The results showed that through underground coal gasification, gangue discharge is eliminated, sulfur emission is reduced, and the amount of ash, mercury, and tar discharge are decreased. Moreover, effect of underground gasification on underground water is analyzed and CO2 disposal method is put forward.

  14. Pyrolysis of sunnyside (Utah) tar sand: Characterization of volatile compound evolution

    SciTech Connect

    Reynolds, J.G.; Crawford, R.W.

    1988-06-01

    Tar sand is defined as any sand or rock which is impregnated with heavy oil or bitumen. (This excludes coal, oil shale, and Gilsonite). In the United States alone, there are an estimated 60 billion barrels of bitumen in tar sand, some of which is recoverable. The Sunnyside deposit in Utah accounts for approximately 4.4 billion barrels of recoverable bitumen, making it an attractive deposit for recovery processing. Several commercial concerns have had financial interest in the development of recovery processing, including in-situ thermal (Shell Oil), steam flooding (Signal Oil and Gas), and solvent extraction (AMOCO). Laboratory pyrolysis of a given tar sand is useful in pyrolysis type recovery research, both in-situ and surface. Several laboratory studies have been performed on Sunnyside tar sand, to elucidate its performance - fluidized-bed and fixed-bed pyrolysis, hydropryolysis, hot water and solvent extraction. This paper summarizes the authors' initial efforts in the laboratory pyrolysis of Sunnyside tar sand, and compares the results to the pyrolysis of other domestic tar sands (Asphalt Ridge from Utah and Big Clifty from Kentucky) studied under the same conditions.

  15. Solubilities of heavy fossil fuels in compressed gases. Calculation of dew points in tar-containing gas streams

    SciTech Connect

    Monge, A.; Prausnitz, J.M.

    1984-04-01

    A molecular-thermodynamic model is used to establish a correlation for solubilities of heavy fossil fuels in dense gases (such as those from a coal gasifier) in the region from ambient to 100 bar and 600 K. This model is then applied to calculate dew points in tar-containing gas streams. Experimental solubility measurements have been made for 2 Lurgi coal-tar fractions in dry and moist methane. Calculated and experimental solubilities agree well. The correlation is used to establish a design-oriented computer program such as can be used for the design of a continuous-flow heat exchanger.

  16. Tar loads on Omani beaches

    SciTech Connect

    Badawy, M.I.; Al-Harthy, F.T. )

    1991-11-01

    Owing to Oman's geographic position and long coastal line, the coastal areas of Oman are particularly vulnerable to oil pollution from normal tanker operations, illegal discharges, and accidental spills as well as local sources of oil input. UNEP carried out a survey on the coasts of Oman to determine the major sources of oil pollution and concluded that the major shoreline pollution problems in Oman arose from operational discharges of oil from passing vessels traffic. The oil, because of the high sea and air temperatures in the area, was subjected to relatively high rates of evaporation and photo-oxidation and tended to arrive at the coast as heavy petroleum particulate residues (tar balls). The aim of the present study was to measure the loads of tar balls in Omani coastal areas and to identify the source of oil pollutants on beaches.

  17. Cockroach allergy.

    PubMed

    Katial, Rohit K

    2003-08-01

    The ubiquitous existence of cockroaches and the large-scale domestic infestation seen in inner cities make cockroach proteins a significant indoor allergen and a risk factor for asthma among inner-city residents. Studies have shown that early exposure to high levels of allergen may lead to the development of asthma in individuals with a genetic predisposition to asthma. Although field trials at cockroach abatement do not yield promising results, integrated pest management still remains the best control strategy. In highly susceptible or symptomatic patients, allergen-specific immunotherapy may be beneficial, although data are limited. As molecular techniques improve and recombinant allergens are developed, a more novel form of T-cell-specific immunotherapy may prove to be efficacious without the anaphylactic side effects seen with traditional allergy vaccines.

  18. Fundamental studies of coal liquefaction

    SciTech Connect

    Not Available

    1995-01-01

    The authors have examined the pyrolysis of Argonne samples of Wyodak and Illinois No. 6 coal in argon, undecane, Tetralin, and water. The effects of the pyrolysis on individual particles of coal were monitored visually in a cell with diamond windows capable of operation to temperature and pressures in excess of 500{degrees}C and 3000 psi. The changes in the particles from ambient to 460{degrees}C were recorded in real time on video tape, and images were then taken from the tape record and analyzed. The study showed that in argon both coals developed tars at 350{degrees}-370{degrees}C. The tars then quickly evaporated, leaving core particles remarkably similar in size and shape to the initial particles. These observations suggest that coal does not melt nor become fully liquid when heated. Nor does the softened coal undergo crosslinking to generate coke. Rather the simple loss of volatiles leaves behind the core residue as coke. Contrary to the common view, there appears to be no link between the bond-breaking processes yielding tar and the interaction of the coal with H-donors leading to liquefaction. Water as a medium was surprising in its effect. Both coals began to shrink at 300{degrees}-350{degrees}C, with the effect appearing to be more of an erosion rather than a uniform loss of substance as seen in Tetralin. The Wyodak continued to shrink to 460{degrees}C to about half its initial size. With the Illinois No. 6 coal, however, the process reversed at around 420{degrees}C, and the particles appeared to grow with the evolution of a tar, continuing to 460{degrees}C. The authors submit that this final observation is evidence for hydrothermal synthesis of hydrocarbons at these conditions.

  19. Allergy prevention.

    PubMed

    Muche-Borowski, Cathleen; Kopp, Matthias; Reese, Imke; Sitter, Helmut; Werfel, Thomas; Schäfer, Torsten

    2010-09-01

    The further increase of allergies in industrialized countries demands evidence-based measures of primary prevention. The recommendations as published in the guideline of 2004 were updated and consented on the basis of a systematic literature search. Evidence from the period February 2003-May 2008 was searched in the electronic databases Cochrane and MEDLINE as well as in reference lists of recent reviews and by contacting experts. The retrieved citations were screened for relevance first by title and abstract and in a second step as full paper. Levels of evidence were assigned to each included study and the methodological quality of the studies was assessed as high or low. Finally the revised recommendations were formally consented (nominal group process) by representatives of relevant societies and organizations including a self-help group. Of originally 4556 hits, 217 studies (4 Cochrane Reviews, 14 meta-analyses, 19 randomized controlled trials, 135 cohort and 45 case-control studies) were included and critically appraised. Grossly unchanged remained the recommendations on avoiding environmental tobacco smoke, breast-feeding over 4 months (alternatively hypoallergenic formulas for children at risk), avoiding a mold-promoting indoor climate, vaccination according to current recommendations, and avoidance of furry pets (especially cats) in children at risk. The recommendation on reducing the house dust mite allergen exposure as a measure of primary prevention was omitted and the impact of a delayed introduction of supplementary food was reduced. New recommendations were adopted concerning fish consumption (during pregnancy / breast-feeding and as supplementary food in the first year), avoidance of overweight, and reducing the exposure to indoor and outdoor air pollutants. The revision of this guideline on a profound evidence basis led to (1) a confirmation of existing recommendations, (2) substantial revisions, and (3) new recommendations. Thereby it is possible

  20. Oil recovery from tar sands

    SciTech Connect

    Boesiger, D.D.; Siefkin, J.M.

    1983-01-11

    A process for recovering oil from oil wet and particularly from oil-wet, acidic tar sands is described in which these sands are subjected to vigorous fluidization in the presence of water, air and a surfactant but in the absence of an extraneous hydrocarbon solvent. This step produces a multiphase mixture including an oil containing froth enabling gravity separation, E.G. In hydrocyclone.

  1. Seasonal Allergy Research at NIH

    MedlinePlus

    ... this page please turn Javascript on. Feature: Managing Allergies Seasonal Allergy Research at NIH Past Issues / Spring 2013 Table of Contents To Find Out More MedlinePlus: Allergy medlineplus.gov/allergy.html MedlinePlus: Hay Fever medlineplus. ...

  2. Latex allergies - for hospital patients

    MedlinePlus

    ... Allergy Association; American College of Allergy, Asthma and Immunology. Guidelines for the Management of Latex Allergies. Updated 2016. latexallergyresources.org/articles/guidelines-management-latex-allergies . Accessed April 7, 2016.

  3. Inhalant allergies in children.

    PubMed

    Mims, James W; Veling, Maria C

    2011-06-01

    Children with chronic or recurrent upper respiratory inflammatory disease (rhinitis) should be considered for inhalant allergies. Risk factors for inhalant allergies in children include a first-degree relative with allergies, food allergy in infancy, and atopic dermatitis. Although inhalant allergies are rare in infancy, inhalant allergies are common in older children and impair quality of life and productivity. Differentiating between viral and allergic rhinitis can be challenging in children, but the child's age, history, and risk factors can provide helpful information. Allergic rhinitis is a risk factor for asthma, and if one is present, medical consideration of the other is warranted. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Analysis of tars produced in biomass gasification

    SciTech Connect

    Zhou, J.; Wang, Y.; Kinoshita, C.M.

    1993-12-31

    Parametric tests on tar formation, varying temperature, equivalence ratio, and residence time, are performed on a bench-scale, indirectly-heated fluidized bed gasifier. Prepared tar samples are analyzed in a gas chromatograph (GC) with a flame ionization detector, using a capillary column. Standards containing dominant tar species have been prepared for GC calibration. The identified peaks include single-ring hydrocarbons, such as benzene, to five-ring hydrocarbons, such as perylene; depending on the gasification conditions, the identified species represent about 70 to 90% (mass basis) of the tar constituents. Under all conditions tested, benzene and naphthalene were the most dominant species. Temperature and equivalence ratio have significant effect on tar yield and tar composition. Tar yield decreases with increasing temperature or equivalence ratio. The test results suggest that lower temperature favors the formation of more aromatic tar species with diversified substituent groups, while higher temperature favors the formation of fewer aromatic tar species without substituent groups. Higher temperature or equivalence ratio favors the formation of polyaromatic compounds. Oxygen-containing compounds exist in significant quantities only at temperature below 800{degrees}C and decrease with increasing temperature, equivalence ratio, or residence time.

  5. Skin Allergy Quiz

    MedlinePlus

    ... time. Some common medications that can cause skin allergy include penicillin, sulfa drugs, barbiturates and anticonvulsants just to mention a few. Some of the symptoms from drug allergies might be hives, skin rash, itchy skin or ...

  6. Tree Nut Allergies

    MedlinePlus

    ... Luncheon Registration Create Your Own Events Educational Events Tree Nut Allergies Tree nut allergy is one of ... with tree nuts during manufacturing and processing. Avoiding Tree Nuts The federal Food Allergen Labeling and Consumer ...

  7. Vaccines for allergy

    PubMed Central

    Linhart, Birgit; Valenta, Rudolf

    2012-01-01

    Vaccines aim to establish or strengthen immune responses but are also effective for the treatment of allergy. The latter is surprising because allergy represents a hyper-immune response based on immunoglobulin E production against harmless environmental antigens, i.e., allergens. Nevertheless, vaccination with allergens, termed allergen-specific immunotherapy is the only disease-modifying therapy of allergy with long-lasting effects. New forms of allergy diagnosis and allergy vaccines based on recombinant allergen-derivatives, peptides and allergen genes have emerged through molecular allergen characterization. The molecular allergy vaccines allow sophisticated targeting of the immune system and may eliminate side effects which so far have limited the use of traditional allergen extract-based vaccines. Successful clinical trials performed with the new vaccines indicate that broad allergy vaccination is on the horizon and may help to control the allergy pandemic. PMID:22521141

  8. Dust Mite Allergy

    MedlinePlus

    ... in dust mite allergy. What causes the allergic reaction Allergies occur when your immune system reacts to ... nurse observes your skin for signs of allergic reactions after 15 minutes. If you're allergic to ...

  9. Do Allergies Cause Asthma?

    MedlinePlus

    ... triggered by an allergy to something (called an allergen ). In these people, the symptoms of asthma like ... breathing are often brought on by being around allergens. Allergies have a lot to do with your ...

  10. Learning about Allergies

    MedlinePlus

    ... Well, you and your dad might have allergies. Chain Reaction An allergy (say: AL-ur-jee) is your immune system's reaction to certain plants, animals, foods, insect bites , or other things. Your immune system ...

  11. Sorting Out Seasonal Allergies

    MedlinePlus

    ... Close ‹ Back to Healthy Living Sorting Out Seasonal Allergies Sneezing, runny nose, nasal congestion. Symptoms of the ... How do I know if I have seasonal allergies? According to Dr. Georgeson, the best way to ...

  12. Allergy - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Allergy URL of this page: https://medlineplus.gov/languages/allergy.html Other topics A-Z Expand Section ...

  13. Inclined fluidized bed system for drying fine coal

    DOEpatents

    Cha, Chang Y.; Merriam, Norman W.; Boysen, John E.

    1992-02-11

    Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

  14. Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

    SciTech Connect

    Zhang, Lingzhi; Wei, Wei; Manke, Jeff; Vazquez, Arturo; Thompson, Jeff; Thompson, Mark

    2011-05-28

    Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical

  15. Allergies: The Hidden Hazard.

    ERIC Educational Resources Information Center

    Rapp, Doris J.

    1990-01-01

    Children can suffer from allergies that can markedly affect their behavior and school performance. Once an allergy is suspected, teachers and principals can consider allergens inside the school, outside the school, and related to problem foods or chemicals. A sidebar lists some allergy clues to watch for. Includes nine references. (MLH)

  16. Addressing Food Allergies

    ERIC Educational Resources Information Center

    DeVoe, Jeanne Jackson

    2008-01-01

    Since 1960, the incidence of food allergies in children has grown fivefold, from 1 in 100 children to 1 in 20 children, according to the Food Allergy Initiative. Food allergies cause anaphylactic shock, the most severe type of allergic reaction, which can lead to death within minutes if left untreated. While there are no standard guidelines from…

  17. Coconut Allergy Revisited.

    PubMed

    Anagnostou, Katherine

    2017-09-29

    Despite concerns voiced often by food-allergic patients, allergy to coconut is rare, not directly associated with nut allergy and few cases are reported so far in the literature. We present an interesting case of coconut allergy in a child that was previously tolerant to coconut and regularly exposed via both the skin and gastrointestinal route.

  18. Antihistamines for allergies

    MedlinePlus

    ... allergy symptoms, such as a pet or certain plants For many people with allergies, symptoms are the worst around 4 a.m. to 6 a.m. Taking an antihistamine at bedtime may help you or your child feel better in the morning during allergy season.

  19. Milk Allergy in Infants

    MedlinePlus

    ... Habits for TV, Video Games, and the Internet Milk Allergy in Infants KidsHealth > For Parents > Milk Allergy ... español Alergia a la leche en bebés About Milk Allergy People of any age can have a ...

  20. Do Allergies Cause Asthma?

    MedlinePlus

    ... Week of Healthy Breakfasts Shyness Do Allergies Cause Asthma? KidsHealth > For Teens > Do Allergies Cause Asthma? Print A A A en español ¿Las alergias provocan asma? Do allergies cause asthma? The answer to that question is: yes and ...

  1. Do Allergies Cause Asthma?

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Do Allergies Cause Asthma? KidsHealth > For Teens > Do Allergies Cause Asthma? A A A en español ¿Las alergias provocan asma? Do allergies cause asthma? The answer to that question is: ...

  2. Diversity of Food Allergy.

    PubMed

    Moriyama, Tatsuya

    2015-01-01

    Food allergy is defined as an immune system-mediated adverse reaction to food components. Food allergic reactions are mostly IgE mediated and also known as immediate type hypersensitivity (type I reaction). There are several characteristic clinical types of food allergy, such as Anaphylaxis, Food-dependent exercise-induced anaphylaxis (FDEIA), and Oral allergy syndrome (OAS). In addition, food allergy is also classified into two types (class 1 and class 2) based on the pathophysiological mechanism. In the class 2 food allergy, pollen allergy causes plant food allergy; therefore this type of allergy is sometimes called Pollen-food allergy syndrome (PFAS). The risk of food allergy (allergenicity) may vary with the treatment of the food allergens. The formation or status of the causative food affects its allergenicity. Class 1 food allergens are generally heat-, enzyme-, and low pH-resistant glycoproteins ranging in size from 10 to 70 kD. Class 1 food allergens induce allergic sensitization via the gastrointestinal tract and are responsible for systemic reactions. Class 2 food allergens are generally heat-labile, susceptible to digestion, and highly homologous with pollen allergens. Taken together, it may be important to consider the diversity of food allergy in order to fight against food allergy.

  3. [Latex allergy in children].

    PubMed

    Mavale-Manuel, S; Paty, E; Scheinmann, P; de Blic, J

    2003-08-01

    The aim of our study was to determine the prevalence of latex allergy and the clinical features of children with latex allergy. We prospectively investigated 243 children consulting in our allergy out-patients unit during 1 year. Parents answered a questionnaire, and children underwent skin prick tests with common allergens and latex. Latex-specific serum immunoglobulin E was determined by CAP test in children with latex sensitization. The results were compared in children with and without latex allergy. The prevalence of latex allergy was 1.3%. A family history of atopy (75%) and a personal history of previous surgery was associated with latex allergy (P < 0.0001). In children with latex allergy, the frequency of sensitization to inhaled and food allergens, atopic dermatitis, rhinitis and conjunctivitis was higher than in children without latex allergy (P < 0.05). Avocado allergy was the food allergy most commonly associated with clinical symptoms. Balloon was the most common latex product causing symptoms (60%). Due to its potential severe consequences, latex allergy should be investigated in children who had undergone multiple surgical procedures and in the children with pollen-food allergy syndrome. Avoidance of latex is an important preventive measure.

  4. Addressing Food Allergies

    ERIC Educational Resources Information Center

    DeVoe, Jeanne Jackson

    2008-01-01

    Since 1960, the incidence of food allergies in children has grown fivefold, from 1 in 100 children to 1 in 20 children, according to the Food Allergy Initiative. Food allergies cause anaphylactic shock, the most severe type of allergic reaction, which can lead to death within minutes if left untreated. While there are no standard guidelines from…

  5. Allergies: The Hidden Hazard.

    ERIC Educational Resources Information Center

    Rapp, Doris J.

    1990-01-01

    Children can suffer from allergies that can markedly affect their behavior and school performance. Once an allergy is suspected, teachers and principals can consider allergens inside the school, outside the school, and related to problem foods or chemicals. A sidebar lists some allergy clues to watch for. Includes nine references. (MLH)

  6. Site clean up of coal gasification residues

    SciTech Connect

    Wilson, J.W.; Ding, Y.

    1995-12-31

    The coal gasification plant residues tested in this research consists of various particle sizes of rock, gravel, tar-sand agglomerates, fine sand and soil. Most of the soils particles were tar free. One of the fractions examined contained over 3000 ppM polyaromatic hydrocarbons (PAHs). The residues were subjected to high pressure water jet washing, float and sink tests, and soil washing. Subsequent PAH analyses found less than 1 ppM PAHs in the water jet washing water. Soils washed with pure water lowered PAH concentrations to 276 ppM; the use of surfactants decreased PAHs to 47, 200, and 240 ppM for different test conditions. In the 47 ppM test, the surfactant temperature had been increased to 80 C, suggesting that surfactant washing efficiency can be greatly improved by increasing the solution temperature. The coal tar particles were not extracted by the surfactants used. Coke and tar-sand agglomerates collected from the float and sink gravimetric separation were tested for heating value. The tar exhibited a very high heating value, while the coke had a heating value close to that of bituminous coal. These processes are believed to have the potential to clean up coal gasification plant residues at a fairly low cost, pending pilot-scale testing and a feasibility study.

  7. Hydrothermal pretreatment of coal

    SciTech Connect

    Ross, D.S.

    1989-12-21

    We have examined changes in Argonne Premium samples of Wyodak coal following 30 min treatment in liquid water at autogenous pressures at 150{degrees}, 250{degrees}, and 350{degrees}C. In most runs the coal was initially dried at 60{degrees}C/1 torr/20 hr. The changes were monitored by pyrolysis field ionization mass spectrometry (py-FIMS) operating at 2.5{degrees}C/min from ambient to 500{degrees}C. We recorded the volatility patterns of the coal tars evolved over that temperature range, and in all cases the tar yields were 25%--30% of the starting coal on mass basis. There was essentially no change after the 150{degrees}C treatment. Small increases in volatility were seen following the 250{degrees}C treatment, but major effects were seen in the 350{degrees} work. The tar quantity remained unchanged; however, the volatility increased so the temperature of half volatility for the as-received coal of 400{degrees}C was reduced to 340{degrees}C. Control runs with no water showed some thermal effect, but the net effect from the presence of liquid water was clearly evident. The composition was unchanged after the 150{degrees} and 250{degrees}C treatments, but the 350{degrees} treatment brought about a 30% loss of oxygen. The change corresponded to loss of the elements of water, although loss of OH'' seemed to fit the analysis data somewhat better. The water loss takes place both in the presence and in the absence of added water, but it is noteworthy that the loss in the hydrothermal runs occurs at p(H{sub 2}O) = 160 atm. We conclude that the process must involve the dehydration solely of chemically bound elements of water, the dehydration of catechol is a specific, likely candidate.

  8. Sydney Tar Ponds Remediation: Experience to China

    ERIC Educational Resources Information Center

    Liu, Fan; Bryson, Ken A.

    2009-01-01

    The infamous "Sydney Tar Ponds" are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief…

  9. Sydney Tar Ponds Remediation: Experience to China

    ERIC Educational Resources Information Center

    Liu, Fan; Bryson, Ken A.

    2009-01-01

    The infamous "Sydney Tar Ponds" are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief…

  10. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    SciTech Connect

    Dady Dadyburjor; Philip R. Biedler; Chong Chen; L. Mitchell Clendenin; Manoj Katakdaunde; Elliot B. Kennel; Nathan D. King; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2004-08-31

    This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon foam and carbon fibers. The focus of this effort was on development of lower cost solvents, milder hydrogenation conditions and improved yield in order to enable practical production of these products. This technology is needed because of the long-term decline in production of domestic feedstocks such as petroleum pitch and coal tar pitch. Currently, carbon products represents a market of roughly 5 million tons domestically, and 19 million tons worldwide. Carbon products are mainly derived from feedstocks such as petroleum pitch and coal tar pitch. The domestic supply of petroleum pitch is declining because of the rising price of liquid fuels, which has caused US refineries to maximize liquid fuel production. As a consequence, the long term trend has a decline in production of petroleum pitch over the past 20 years. The production of coal tar pitch, as in the case of petroleum pitch, has likewise declined significantly over the past two decades. Coal tar pitch is a byproduct of metallurgical grade coke (metcoke) production. In this industry, modern metcoke facilities are recycling coal tar as fuel in order to enhance energy efficiency and minimize environmental emissions. Metcoke production itself is dependent upon the production requirements for domestic steel. Hence, several metcoke ovens have been decommissioned over the past two decades and have not been replaced. As a consequence sources of coal tar are being taken off line and are not being replaced. The long-term trend is a reduction in coal tar pitch production. Thus import of feedstocks, mainly from Eastern Europe and China, is on the rise despite the relatively large transportation cost. To reverse this trend, a new process for producing carbon products is needed. The process must be

  11. An engineering model for coal devolatilization

    SciTech Connect

    Hickerson, J. . Pittsburgh Energy Technology Center)

    1990-01-01

    This research program aims for an engineering model for the evolution of volatile products from coal during pulverized coal combustion. The performance specifications include: (1) compatibility with the computational constraints of large-scale combustor simulators; (2) reliable predictions of the yields of noncondensible gases, tar, char, and unreacted coal for arbitrary thermal histories and ambient conditions; (3) predictions of the tar molecular weight distribution and aromaticity throughout the technological operating domain; and (4) a mathematical framework for the influence of coal type. The program is organized into four tasks. The objective of Task 1 is an engineering model to account for the influence of ambient pressure on the yields and tar molecular weight distributions, including an evaluation against reported devolatilization studies. While the engineering model does not explicitly account for variations in coal type, the theory developed in Task 2 aims for a theoretical framework to handle them. It describes the complete distributions of molecular fragments from a depolymerizing macromolecular network, the reintegration of nonvolatile fragments into a char lattice, and the simultaneous evolution of volatiles by flash distillation. In Task 3, the engineering model is supplemented with descriptions of the chemistry, heat and mass transport in the vicinity of individual coal particles, to model the initial stages of the combustion of entrained coal particles. Task 4 emphasizes heuristic treatments of coal type effects developed from the full depolymerization scheme (Task 2), and their evaluation against data. 14 refs., 8 figs., 2 tabs.

  12. ICON: food allergy.

    PubMed

    Burks, A Wesley; Tang, Mimi; Sicherer, Scott; Muraro, Antonella; Eigenmann, Philippe A; Ebisawa, Motohiro; Fiocchi, Alessandro; Chiang, Wen; Beyer, Kirsten; Wood, Robert; Hourihane, Jonathan; Jones, Stacie M; Lack, Gideon; Sampson, Hugh A

    2012-04-01

    Food allergies can result in life-threatening reactions and diminish quality of life. In the last several decades, the prevalence of food allergies has increased in several regions throughout the world. Although more than 170 foods have been identified as being potentially allergenic, a minority of these foods cause the majority of reactions, and common food allergens vary between geographic regions. Treatment of food allergy involves strict avoidance of the trigger food. Medications manage symptoms of disease, but currently, there is no cure for food allergy. In light of the increasing burden of allergic diseases, the American Academy of Allergy, Asthma & Immunology; European Academy of Allergy and Clinical Immunology; World Allergy Organization; and American College of Allergy, Asthma & Immunology have come together to increase the communication of information about allergies and asthma at a global level. Within the framework of this collaboration, termed the International Collaboration in Asthma, Allergy and Immunology, a series of consensus documents called International Consensus ON (ICON) are being developed to serve as an important resource and support physicians in managing different allergic diseases. An author group was formed to describe the natural history, prevalence, diagnosis, and treatment of food allergies in the context of the global community.

  13. Pulse dipolar ESR of doubly labeled mini TAR DNA and its annealing to mini TAR RNA.

    PubMed

    Sun, Yan; Borbat, Peter P; Grigoryants, Vladimir M; Myers, William K; Freed, Jack H; Scholes, Charles P

    2015-02-17

    Pulse dipolar electron-spin resonance in the form of double electron electron resonance was applied to strategically placed, site-specifically attached pairs of nitroxide spin labels to monitor changes in the mini TAR DNA stem-loop structure brought on by the HIV-1 nucleocapsid protein NCp7. The biophysical structural evidence was at Ångstrom-level resolution under solution conditions not amenable to crystallography or NMR. In the absence of complementary TAR RNA, double labels located in both the upper and the lower stem of mini TAR DNA showed in the presence of NCp7 a broadened distance distribution between the points of attachment, and there was evidence for several conformers. Next, when equimolar amounts of mini TAR DNA and complementary mini TAR RNA were present, NCp7 enhanced the annealing of their stem-loop structures to form duplex DNA-RNA. When duplex TAR DNA-TAR RNA formed, double labels initially located 27.5 Å apart at the 3'- and 5'-termini of the 27-base mini TAR DNA relocated to opposite ends of a 27 bp RNA-DNA duplex with 76.5 Å between labels, a distance which was consistent with the distance between the two labels in a thermally annealed 27-bp TAR DNA-TAR RNA duplex. Different sets of double labels initially located 26-27 Å apart in the mini TAR DNA upper stem, appropriately altered their interlabel distance to ~35 Å when a 27 bp TAR DNA-TAR RNA duplex formed, where the formation was caused either through NCp7-induced annealing or by thermal annealing. In summary, clear structural evidence was obtained for the fraying and destabilization brought on by NCp7 in its biochemical function as an annealing agent and for the detailed structural change from stem-loop to duplex RNA-DNA when complementary RNA was present. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Characteristics of Pyrolytic Topping in Fluidized Bed for Different Volatile Coals

    NASA Astrophysics Data System (ADS)

    Xiong, R.; Dong, L.; Xu, G. W.

    Coal is generally combusted or gasified directly to destroy completely the chemical structures, such as aromatic rings containing in volatile coals including bituminite and lignite. Coal topping refers to a process that extracts chemicals with aromatic rings from such volatile coals in advance of combustion or gasification and thereby takes advantage of the value of coal as a kind of chemical structure resource. CFB boiler is the coal utilization facility that can be easily retrofitted to implement coal topping. A critical issue for performing coal topping is the choice of the pyrolytic reactor that can be different types. The present study concerns fluidized bed reactor that has rarely been tested for use in coal topping. Two different types of coals, one being Xiaolongtan (XLT) lignite and the other Shanxi (SX) bituminous, were tested to clarify the yield and composition of pyrolysis liquid and gas under conditions simulating actual operations. The results showed that XLT lignite coals had the maximum tar yield in 823-873K and SX bituminite realized its highest tar yield in 873-923K. Overall, lignite produced lower tar yield than bituminous coal. The pyrolysis gas from lignite coals contained more CO and CO2 and less CH4, H2 and C2+C3 (C2H4, C2H6, C3H6, C3H8) components comparing to that from bituminous coal. TG-FTIR analysis of tars demonstrated that for different coals there are different amounts of typical chemical species. Using coal ash of CFB boiler, instead of quartz sand, as the fluidized particles decreased the yields of both tar and gas for all the tested coals. Besides, pyrolysis in a reaction atmosphere simulating the pyrolysis gas (instead of N2) resulted also in higher production of pyrolysis liquid.

  15. Horizontal oil shale and tar sands retort

    SciTech Connect

    Thomas, D.D.

    1982-08-31

    A horizontal retorting apparatus and method are disclosed designed to pyrolyze tar sands and oil shale, which are often found together in naturally occurring deposits. The retort is based on a horizontal retorting tube defining a horizontal retort zone having an upstream and a downstream end. Inlet means are provided for introducing the combined tar sands and oil shale into the upstream end of the retort. A screw conveyor horizontally conveys tar sands and oil shale from the upstream end of the retort zone to the downstream end of the retort zone while simultaneously mixing the tar sands and oil shale to insure full release of product gases. A firebox defining a heating zone surrounds the horizontal retort is provided for heating the tar sands and oil shale to pyrolysis temperatures. Spent shale and tar sands residue are passed horizontally beneath the retort tube with any carbonaceous residue thereon being combusted to provide a portion of the heat necessary for pyrolysis. Hot waste solids resulting from combustion of spent shale and tar sands residue are also passed horizontally beneath the retort tube whereby residual heat is radiated upward to provide a portion of the pyrolysis heat. Hot gas inlet holes are provided in the retort tube so that a portion of the hot gases produced in the heating zone are passed into the retort zone for contacting and directly heating the tar sands and oil shale. Auxiliary heating means are provided to supplement the heat generated from spent shale and tar sands residue combustion in order to insure adequate pyrolysis of the raw materials with varying residual carbonaceous material.

  16. Reduction of tar, nicotine and carbon monoxide intake in low tar smokers.

    PubMed Central

    Russell, M A; Jarvis, M J; Feyerabend, C; Saloojee, Y

    1986-01-01

    Blood nicotine, cotinine, and carboxyhaemoglobin (COHb) concentrations were measured in 392 smokers (255 women and 137 men) of "middle tar" (17-22 mg), "low to middle" (11-16 mg), and "low tar" (less than 11 mg) cigarettes. Since tar intake cannot yet be measured directly, we devised an index to estimate it based on the use of measured levels of an intake marker (eg, blood nicotine) and the ratio of the tar to marker yields of the cigarettes. This approach was validated by its ability to enhance the prediction of levels of one marker by use of another. In a practical test, using COHb and the CO/nicotine yield ratio of the cigarettes, the mean blood nicotine concentration of the low tar smokers was predicted to be 31.9 ng/ml compared with the measured mean of 31.8 ng/ml. Our main findings were that despite substantial compensatory increases in inhalation, the low tar smokers took in about 25% less tar, about 15% less nicotine, and about 10% less carbon monoxide than smokers of middle and low to middle tar cigarettes. These results indicate that low tar cigarettes of the type available in Britain since the late 1970s are likely to prove less harmful than other brands. Monitoring of smoke intakes could supplement epidemiological approaches and provide earlier evidence of whether changing cigarette designs lead to any significant dosage reduction that could affect the risk of disease. PMID:3711773

  17. [SEAFOOD ALLERGY IN ISRAEL].

    PubMed

    Rottem, Menachem

    2015-10-01

    Allergy to seafood such as shrimps, crab, lobster and fish eggs is relatively infrequent in Israel compared to fish allergies and allergies to other foods. This is mainly due to the fact that most of the population and restaurants preserve and maintain Kosher food. Changes in the population eating habits, partly due to immigration, were followed by increased frequency of such sensitivities in recent years. We describe three typical cases that illustrate the characteristics of allergy to sea foods. Allergy to seafood can present as a single sensitivity or be part of an allergic tendency, atopy, with other allergic manifestations. Diagnosis by allergy skin test or laboratory evaluation by specific IgE is available for most sea foods but not for fish eggs. The current therapeutic approach is strict avoidance and all patients should be provided with and carry with them an epinephrine auto-injector.

  18. Food allergy: an overview.

    PubMed

    Kagan, Rhoda Sheryl

    2003-02-01

    Food allergy affects between 5% and 7.5% of children and between 1% and 2% of adults. The greater prevalence of food allergy in children reflects both the increased predisposition of children to develop food allergies and the development of immunologic tolerance to certain foods over time. Immunoglobulin (Ig) E-mediated food allergies can be classified as those that persist indefinitely and those that are predominantly transient. Although there is overlap between the two groups, certain foods are more likely than others to be tolerated in late childhood and adulthood. The diagnosis of food allergy rests with the detection of food-specific IgE in the context of a convincing history of type I hypersensitivity-mediated symptoms after ingestion of the suspected food or by eliciting IgE-mediated symptoms after controlled administration of the suspected food. Presently, the only available treatment of food allergies is dietary vigilance and administration of self-injectable epinephrine.

  19. Treating tar sands formations with dolomite

    DOEpatents

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  20. Laboratory evaluation of selected tar sand asphalts

    SciTech Connect

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  1. Natural rubber latex allergy.

    PubMed

    Deval, Ravi; Ramesh, V; Prasad, G B K S; Jain, Arun Kumar

    2008-01-01

    Natural rubber latex (NRL) is a ubiquitous allergen as it is a component of > 40,000 products in everyday life. Latex allergy might be attributed to skin contact or inhalation of latex particles. Latex allergy is an IgE-mediated hypersensitivity to NRL, presenting a wide range of clinical symptoms such as angioedema, swelling, cough, asthma, and anaphylactic reactions. Until 1979, latex allergy appeared only as type IV delayed hypersensitivity; subsequently, the proportion of different allergy types drifted towards type IV contact allergy reactions. Several risk factors for sensitization to NRL are already known and well documented. Some authors have established a positive correlation between a history of multiple surgical interventions, atopy, spina bifida malformation, and latex allergy incidence. We suspect an increase in latex allergy incidence in association with increased atopy and sensitivity to environmental allergens in the industrial population. It is often postulated in literature that the groups of workers at risk for this allergy are essentially workers in the latex industry and healthcare professionals. In this population, direct internal and mucosal contact with NRL medical devices may be the route of sensitization as factors such as the number of procedures and use of NRL materials (catheters and tubes) were associated with increased risk of latex sensitization and allergy.

  2. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    SciTech Connect

    Elliot B. Kennel; Chong Chen; Dady Dadyburjor; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-07-13

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. The Hydrotreatment Facility is being prepared for trials with coal liquids. Raw coal tar distillate trials have been carried out by heating coal tar in the holding tank in the Hydrotreatment Facility. The liquids are centrifuged to warm the system up in preparation for the coal liquids. The coal tar distillate is then recycled to keep the centrifuge hot. In this way, the product has been distilled such that a softening point of approximately 110 C is reached. Then an ash test is conducted.

  3. Synthesis of isotropic carbon fibers from coal extracts

    SciTech Connect

    Kimber, G.M.; Vego, A.; Rantell, T.D.; Fowler, C.; Johnson, A.; Derbyshire, F.J.

    1996-12-31

    General Purpose Carbon Fibers (GPCF) are produced commercially from isotropic petroleum and coal-tar pitch precursors. Their lower cost makes them more attractive than high performance PAN (polyacrylonitrile) based or mesophase pitch-based fibers for applications where ultra-high strength or stiffness is not required. In recent years there has also been a growing interest in the use of activated carbon fibers in environmental and gas separation applications. Potentially low cost fiber precursors could be produced from coals by solvent extraction. Such extracts can be obtained in much higher yields than coal tar pitch (e.g., >50 wt.% versus <5 wt.% of coal). There is also the opportunity to widely vary the coal extract properties by control of reaction conditions (e.g., coal rank, type of solvent, reactant gas, heat treatment temperature and time) and thus alter the conditions required for fiber synthesis and the properties of the carbonized and activated fiber products.

  4. Dominant role of the 5' TAR bulge in dimerization of HIV-1 genomic RNA, but no evidence of TAR-TAR kissing during in vivo virus assembly.

    PubMed

    Jalalirad, Mohammad; Saadatmand, Jenan; Laughrea, Michael

    2012-05-08

    The 5' untranslated region of HIV-1 genomic RNA (gRNA) contains two stem-loop structures that appear to be equally important for gRNA dimerization: the 57-nucleotide 5' TAR, at the very 5' end, and the 35-nucleotide SL1 (nucleotides 243-277). SL1 is well-known for containing the dimerization initiation site (DIS) in its apical loop. The DIS is a six-nucleotide palindrome. Here, we investigated the mechanism of TAR-directed gRNA dimerization. We found that the trinucleotide bulge (UCU24) of the 5' TAR has dominant impacts on both formation of HIV-1 RNA dimers and maturation of the formed dimers. The ΔUCU trinucleotide deletion strongly inhibited the first process and blocked the other, thus impairing gRNA dimerization as severely as deletion of the entire 5' TAR, and more severely than deletion of the DIS, inactivation of the viral protease, or most severe mutations in the nucleocapsid protein. The apical loop of TAR contains a 10-nucleotide palindrome that has been postulated to stimulate gRNA dimerization by a TAR-TAR kissing mechanism analogous to the one used by SL1 to stimulate dimerization. Using mutations that strongly destabilize formation of the TAR palindrome duplex, as well as compensatory mutations that restore duplex formation to a wild-type-like level, we found no evidence of TAR-TAR kissing, even though mutations nullifying the kissing potential of the TAR palindrome could impair dimerization by a mechanism other than hindering of SL1. However, nullifying the kissing potential of TAR had much less severe effects than ΔUCU. By not uncovering a dimerization mechanism intrinsic to TAR, our data suggest that TAR mutations exert their effect 3' of TAR, yet not on SL1, because TAR and SL1 mutations have synergistic effects on gRNA dimerization.

  5. Characteristics of PAH tar oil contaminated soils-Black particles, resins and implications for treatment strategies.

    PubMed

    Trellu, Clément; Miltner, Anja; Gallo, Rosita; Huguenot, David; van Hullebusch, Eric D; Esposito, Giovanni; Oturan, Mehmet A; Kästner, Matthias

    2017-04-05

    Tar oil contamination is a major environmental concern due to health impacts of polycyclic aromatic hydrocarbons (PAH) and the difficulty of reaching acceptable remediation end-points. Six tar oil-contaminated soils with different industrial histories were compared to investigate contamination characteristics by black particles. Here we provide a simple method tested on 6 soils to visualize and identify large amounts of black particles (BP) as either solid aggregates of resinified and weathered tar oil or various wood/coke/coal-like materials derived from the contamination history. These materials contain 2-10 times higher PAH concentrations than the average soil and were dominantly found in the sand fraction containing 42-86% of the total PAH. The PAH contamination in the different granulometric fractions was directly proportional to the respective total organic carbon content, since the PAH were associated to the carbonaceous particulate materials. Significantly lower (bio)availability of PAH associated to these carbonaceous phases is widely recognized, thus limiting the efficiency of remediation techniques. We provide a conceptual model of the limited mass transfer of PAH from resinated tar oil phases to the water phase and emphasize the options to physically separate BP based on their lower bulk density and slower settling velocity.

  6. Fighting Allergies at School

    ERIC Educational Resources Information Center

    Taylor, Kelley R.

    2008-01-01

    In the last decade, the number of children diagnosed with food allergies has increased significantly--to an estimated 3 million affected in the United States alone (Food Allergy and Anaphylaxis Network, n.d.). As that number increases, so do the articles, legislation, and policies that are designed to address how to best deal with peanut allergies…

  7. Medication/Drug Allergy

    MedlinePlus

    ... every time after the offending medication is taken. Penicillin and other antibiotics are the medication that most commonly cause allergic reactions. Women appear to have an increased risk for adverse reactions to medications. Facts about Allergies The tendency to develop allergies may be inherited. ...

  8. Nut and Peanut Allergy

    MedlinePlus

    ... like a restaurant or bar) where lots of peanuts are being cracked from their shells. The person inhales and then swallows the protein, and this can lead to a reaction when the protein gets digested. Although ... and wheat allergies), peanut and tree nut allergies are lifelong in many ...

  9. Food allergy: current concerns

    SciTech Connect

    Fries, J.H.

    1981-05-01

    This commentary focuses on the author's concerns with various aspects of food allergy. Strict criteria should be applied to the definition of food allergy and its diagnostic techniques. Industrial inhalational exposures, food contaminations and cross-sensitization all are important influences which demand studious attention.

  10. Fighting Allergies at School

    ERIC Educational Resources Information Center

    Taylor, Kelley R.

    2008-01-01

    In the last decade, the number of children diagnosed with food allergies has increased significantly--to an estimated 3 million affected in the United States alone (Food Allergy and Anaphylaxis Network, n.d.). As that number increases, so do the articles, legislation, and policies that are designed to address how to best deal with peanut allergies…

  11. Zero VOC, Coal Tar Free Splash Zone Coating (SZC)

    DTIC Science & Technology

    2010-12-01

    solvents. Early uses included heavy-duty industrial paints and structural adhesives in the aircraft industry . Today, epoxy resin compounds are...Report for the project entitled “Demonstration/Validation of a Zero-VOC Waterborne Polyurethane Topcoat” as highlighted below: • The payback (in...Kevin J. Kovaleski. 2003. Demonstration/Validation of a Zero-VOC Waterborne Polyurethane Topcoat. ESTCP Cost and Performance Report. PP-9802

  12. Zero VOC, Coal Tar Free Splash Zone Coating (SZC)

    DTIC Science & Technology

    2011-09-01

    alkalis, and solvents. Early uses included heavy-duty industrial paints and structural adhesives in the aircraft industry . Today, epoxy resin ...Validation of a Zero-VOC Waterborne Polyurethane Topcoat. ESTCP Cost and Performance Report. PP-9802. January 2003. 17. The Society for...Figure 2. Co-reaction of polysulfides with epoxy resins ........................................................ 8 Figure 3. Demonstration site at NAS

  13. ASSESSING MULTICOMPONENT DNAPL BIOSTABILIZATION: COAL TAR. (R825961)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Creosote and coal tar (non-wood): decision document

    SciTech Connect

    Not Available

    1985-10-02

    The Position Document addresses the risks and benefits of pesticide products containing the subject active ingredient. The Agency has determined that the use of products containing the subject active ingredient may meet or exceed a risk criterion described in 40 CFR Part 154. Potential hazards will be examined further to determine the nature and extent of the risk, and considering the benefits of the subject active ingredient, whether such risks cause unreasonable adverse effects on the environment.

  15. ASSESSING MULTICOMPONENT DNAPL BIOSTABILIZATION: COAL TAR. (R825961)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. Allergy immunotherapy: the future of allergy treatment.

    PubMed

    Larsen, Jørgen Nedergaard; Broge, Louise; Jacobi, Henrik

    2016-01-01

    Allergic respiratory disease represents a significant and expanding health problem worldwide. Allergic symptoms, such as asthma and hay fever, cause sleep impairment and reduce school and work performance. The cost to society is substantial. Allergen avoidance and pharmacotherapy cannot control the disease. Only allergy immunotherapy has disease-modifying potential and should be included in optimal treatment strategies. Allergy immunotherapy was first administered as subcutaneous injections and has been practiced for the past 100 years or so. Recently, tablet-based sublingual allergy immunotherapy (SLIT) was introduced with comprehensive clinical documentation. SLIT tablets represent a more patient-friendly concept because they can be used for self-treatment at home. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. [Allergy in cosmetology].

    PubMed

    Blondeel, A

    1983-01-01

    The computer analysis of a sample collecting 2,028 patients suffering from an eczematous dermatitis and subordinated to epicutaneous tests allowed us to analyze the rather difficult question of cosmetic allergy. This allergy is observed only in 2 p. 100 of the cases, if one considers the cosmetic allergy isolated; it reaches 5 p. 100 if it is associated with allergens coming from other origins (drugs of professional). However, in a more selected population of 91 patients suffering from a face dermatitis, these levels reach respectively 25 and 43 p. 100. The respective role of topic drugs and cosmetics is studied as well as main allergens associated with cosmetic allergy. The good tolerance of cosmetics encountered in patients allergic to one of their presumed components seems paradoxical. A prevention model of cosmetic allergy is presented, with an hypoallergenic variety of lanolin.

  18. Shellfish allergy in children.

    PubMed

    Kandyil, Roshni M; Davis, Carla M

    2009-08-01

    Food allergies affect approximately 3.5-4.0% of the world's population and can range from a mere inconvenience to a life-threatening condition. Over 90% of food allergies in childhood are caused by eight foods: cow's milk, hen's egg, soy, peanuts, tree nuts, wheat, fish, and shellfish. Shellfish allergy is known to be common and persistent in adults, and is an important cause of food induced anaphylaxis around the world for both children and adults. Most shellfish-allergic children have sensitivity to dust mite and cockroach allergens. Diagnostic cut-off levels for skin prick testing in children with shrimp allergy exist but there are no diagnostic serum-specific immunoglobulin E (IgE) values. All patients with symptoms of IgE-mediated reactions to shellfish should receive epinephrine autoinjectors, even if the initial symptoms are mild. In this study, we review three cases of clinical presentations of shellfish allergy in children.

  19. [Food allergy in childhood].

    PubMed

    Beyer, Kirsten; Niggemann, Bodo

    2016-06-01

    IgE-mediated immediate type reactions are the most common form of food allergy in childhood. Primary (often in early childhood) and secondary (often pollen-associated) allergies can be distinguished by their level of severity. Hen's egg, cow's milk and peanut are the most common elicitors of primary food allergy. Tolerance development in hen's egg and cow's milk allergy happens frequently whereas peanut allergy tends toward a lifelong disease. For the diagnostic patient history, detection of sensitization and (in many cases) oral food challenges are necessary. Especially in peanut and hazelnut allergy component-resolves diagnostic (measurement of specific IgE to individual allergens, e. g. Ara h 2) seem to be helpful. In regard to therapy elimination diet is still the only approved approach. Patient education through dieticians is extremely helpful in this regard. Patients at risk for anaphylactic reactions need to carry emergency medications including an adrenaline auto-injector. Instruction on the usage of the adrenaline auto-injector should take place and a written management plan handed to the patient. Moreover, patients or caregivers should be encouraged to attending a structured educational intervention on knowledge and emergency management. In parallel, causal therapeutic options such as oral, sublingual or epicutaneous immunotherapies are currently under development. In regard to prevention of food allergy current guidelines no longer advise to avoid highly allergenic foods. Current intervention studies are investigating wether early introduction of highly allergic foods is effective and safe to prevent food allergy. It was recently shown that peanut introduction between 4 and 11  months of age in infants with severe atopic dermatitis and/or hen's egg allergy (if they are not already peanut allergic) prevents peanut allergy in a country with high prevalence.

  20. [Food allergy in adulthood].

    PubMed

    Werfel, Thomas

    2016-06-01

    Food allergies can newly arise in adulthood or persist following a food allergy occurring in childhood. The prevalence of primary food allergy is basically higher in children than in adults; however, in the routine practice food allergies in adulthood appear to be increasing and after all a prevalence in Germany of 3.7 % has been published. The clinical spectrum of manifestations of food allergies in adulthood is broad. Allergy symptoms of the immediate type can be observed as well as symptoms occurring after a delay, such as indigestion, triggering of hematogenous contact eczema or flares of atopic dermatitis. The same principles for diagnostics apply in this group as in childhood. In addition to the anamnesis, skin tests and in vitro tests, as a rule elimination diets and in particular provocation tests are employed. Molecular allergy diagnostics represent a major step forward, which allow a better assessment of the risk of systemic reactions to certain foodstuffs (e.g. peanuts) and detection of cross-reactions in cases of apparently multiple sensitivities. Current German and European guidelines from 2015 are available for the practical approach to clarification of food allergies. The most frequent food allergies in adults are nuts, fruit and vegetables, which can cross-react with pollen as well as wheat, shellfish and crustaceans. The therapy of allergies involves a consistent avoidance of the allogen. Detailed dietary plans are available with avoidance strategies and instructions for suitable food substitutes. A detailed counseling of affected patients by specially trained personnel is necessary especially in order to avoid nutritional deficiencies and to enable patients to enjoy a good quality of life.

  1. Pulse Dipolar ESR of Doubly Labeled Mini TAR DNA and Its Annealing to Mini TAR RNA

    PubMed Central

    Sun, Yan; Borbat, Peter P.; Grigoryants, Vladimir M.; Myers, William K.; Freed, Jack H.; Scholes, Charles P.

    2015-01-01

    Pulse dipolar electron-spin resonance in the form of double electron electron resonance was applied to strategically placed, site-specifically attached pairs of nitroxide spin labels to monitor changes in the mini TAR DNA stem-loop structure brought on by the HIV-1 nucleocapsid protein NCp7. The biophysical structural evidence was at Ångstrom-level resolution under solution conditions not amenable to crystallography or NMR. In the absence of complementary TAR RNA, double labels located in both the upper and the lower stem of mini TAR DNA showed in the presence of NCp7 a broadened distance distribution between the points of attachment, and there was evidence for several conformers. Next, when equimolar amounts of mini TAR DNA and complementary mini TAR RNA were present, NCp7 enhanced the annealing of their stem-loop structures to form duplex DNA-RNA. When duplex TAR DNA-TAR RNA formed, double labels initially located 27.5 Å apart at the 3′- and 5′-termini of the 27-base mini TAR DNA relocated to opposite ends of a 27 bp RNA-DNA duplex with 76.5 Å between labels, a distance which was consistent with the distance between the two labels in a thermally annealed 27-bp TAR DNA-TAR RNA duplex. Different sets of double labels initially located 26–27 Å apart in the mini TAR DNA upper stem, appropriately altered their interlabel distance to ∼35 Å when a 27 bp TAR DNA-TAR RNA duplex formed, where the formation was caused either through NCp7-induced annealing or by thermal annealing. In summary, clear structural evidence was obtained for the fraying and destabilization brought on by NCp7 in its biochemical function as an annealing agent and for the detailed structural change from stem-loop to duplex RNA-DNA when complementary RNA was present. PMID:25692594

  2. Thermodynamic properties of pulverized coal during rapid heating devolatilization processes. Quarterly progress report, January--March 1994

    SciTech Connect

    Proscia, W.M.; Freihaut, J.D.

    1994-06-01

    Knowledge of the thermodynamic and morphological properties of coal associated with rapid heating decomposition pathways is essential to progress in coal utilization technology. Specifically, knowledge of the heat of devolatilization, surface area and density of coal as a function of rank characteristics, temperature and extent of devolatilization in the context of rapid heating conditions is required both, for the fundamental determination of kinetic parameters of coal devolatilization, and to refine existing devolatilization sub-models used in comprehensive coal combustion codes. The objective of this research is to obtain data on the thermodynamic properties and morphology of coal under conditions of rapid heating. Specifically, the total heat of devolatilization, external surface area, BET surface area and true density will be measured for representative coal samples. In addition, for one coal, the contribution of each of the following components to the overall heat of devolatilization will be measured: the specific heat of coal/char during devolatilization, the heat of thermal decompose ion of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Progress reports are presented for the following tasks: heat of devoltalization of voltaile coal samples; specific heat and heat of fusion of tars; heat of vaporization of tars from rapid heating; and morphological characterization of coal/char samples as a function of extent of devoltalization.

  3. Tar Management and Recycling in Biomass Gasification and Syngas Purification

    NASA Astrophysics Data System (ADS)

    McCaffrey, Zach

    Removal of tars is critical to the design and operation of biomass gasification systems as most syngas utilization processing equipment (e.g. internal combustion engines, gas turbines, fuel cells, and liquid fuel synthesis reactors) have a low tolerance for tar. Capturing and disposal of tar is expensive due to equipment costs, high hazardous waste disposal costs where direct uses cannot be found, and system energy losses incurred. Water scrubbing is an existing technique commonly used in gasification plants to remove contaminants and tar; however using water as the absorbent is non-ideal as tar compounds have low or no water solubility. Hydrophobic solvents can improve scrubber performance and this study evaluated tar solubility in selected solvents using slip-streams of untreated syngas from a laboratory fluidized bed reactor operated on almond composite feedstock using both air and steam gasification. Tar solubility was compared with Hansen's solubility theory to examine the extent to which the tar removal can be predicted. As collection of tar without utilization leads to a hazardous waste problem, the study investigated the effects of recycling tars back into the gasifier for destruction. Prior to experiments conducted on tar capture and recycle, characterizations of the air and steam gasification of the almond composite mix were made. This work aims to provide a better understanding of tar collection and solvent selection for wet scrubbers, and to provide information for designing improved tar management systems for biomass gasification.

  4. Development of Catalytic Tar Decomposition in an Internally Circulating Fluidized-Bed Gasifier

    NASA Astrophysics Data System (ADS)

    Xiao, Xianbin; Le, Due Dung; Morishita, Kayoko; Li, Liuyun; Takarada, Takayuki

    Biomass gasification in an Internally Circulating Fluidized-bed Gasifier (ICFG) using Ni/Ah03 as tar cracking catalyst is studied at low temperature. Reaction conditions of the catalyst bed are discussed, including catalytic temperature and steam ratio. High energy efficiency and hydrogen-rich, low-tar product gas can be achieved in a properly designed multi-stage gasification process, together with high-performance catalyst. In addition, considering the economical feasibility, a newly-developed Ni-loaded brown coal char is developed and evaluated as catalyst in a lab-scale fluidized bed gasifier with catalyst fixed bed. The new catalyst shows a good ability and a hopeful prospect oftar decomposition, gas quality improvement and catalytic stability.

  5. Metal allergy in Singapore.

    PubMed

    Goon, Anthony T J; Goh, C L

    2005-03-01

    This is a clinical epidemiologic study to determine the frequency of metal allergy among patch-tested patients in the years 2001-2003. The results are compared with those of previous studies. All patients diagnosed as having allergic contact dermatitis in the National Skin Centre, Singapore, from January 2001 to December 2003 were studied retrospectively. The frequency of positive patch tests to the following metals were nickel 19.9%, chromate 5.6%, cobalt 8.2% and gold 8.3%. The frequency of nickel allergy has been steadily rising over the last 20 years. The most common sources of nickel allergy are costume jewelry, belt buckles, wrist watches and spectacle frames. After declining from 1984 to 1990, chromate and cobalt allergies have also been steadily increasing subsequently. The most common sources of chromate allergy were cement, leather and metal objects. Most positive patch tests to cobalt are regarded as co-sensitization due to primary nickel or chromate allergies. There has been a steep increase in positive patch tests to gold from 2001 to 2003, which is difficult to explain because the relevance and sources of such positive patch tests can rarely be determined with certainty. There has been an overall rise in the frequency of metal allergy in the last 20 years.

  6. DEVELOPMENT OF CARBON PRODUCTS FROM LOW-RANK COALS

    SciTech Connect

    Edwin S. Olson

    2001-07-01

    The goal of this project is to facilitate the production of carbon fibers from low-rank coal (LRC) tars. To this end, the effect of demineralization on the tar yields and composition was investigated using high-sodium and high-calcium lignites commonly mined in North Dakota. These coals were demineralized by ion exchange with ammonium acetate and by cation dissolution with nitric acid. Two types of thermal processing were investigated for obtaining suitable precursors for pitch and fiber production. Initially, tars were produced by simple pyrolysis of the set of samples at 650 C. Since these experiments produced little usable material from any of the samples, the coals were heated at moderate temperatures (380 and 400 C) in tetralin solvent to form and extract the plastic material (metaplast) that forms at these temperatures.

  7. Drug and vaccine allergy.

    PubMed

    Kelso, John M

    2015-02-01

    Most children with a history of penicillin allergy are labeled allergic and denied treatment with penicillin and sometimes other beta-lactam antibiotics. Most of these children never were or are no longer allergic to penicillin. Penicillin skin testing and oral challenge can identify patients who are not currently allergic, allowing them to be treated with penicillin. Children with egg allergy are often denied influenza vaccination, because the vaccine contains a small amount of egg protein. However, recent studies have demonstrated that children with even severe egg allergy can safely receive the vaccine, reducing their risk of the morbidity and mortality associated with influenza.

  8. Creating fluid injectivity in tar sands formations

    DOEpatents

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2010-06-08

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

  9. Creating fluid injectivity in tar sands formations

    DOEpatents

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2012-06-05

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons including mobilized hydrocarbons are produced from the portion.

  10. Co-pyrolysis of coal/biomass and coal/sewage sludge mixtures

    SciTech Connect

    Storm, C.; Ruediger, H.; Spliethoff, H.; Hein, K.R.G.

    1999-01-01

    Biomass and sewage sludge are attracting increasing interest in power plant technology as a source of carbon-dioxide-neutral fuels. A new way to reduce the consumption of fossil fuels could be the co-combustion or co-gasification of coal and biomass or coal and sewage sludge. In both cases, pyrolysis is the first step in the technical process. In order to obtain detailed information about the pyrolysis of coal/biomass and coal/sewage sludge mixtures as well as unblended fuels, the Institut fuer Verfahrenstechnik and Dampfkesselwesen (IVD) at the University of Stuttgart has carried out investigations using an electrically heated entrained flow reactor. The test runs provided information about fuel conversion efficiency, pyrolysis gas and tar yield, and composition of pyrolysis gas and tar. Besides gas and tar analysis investigations regarding the path of trace elements, like heavy metals, alkali, chlorine and nitrogen components, during the pyrolysis process varying different parameters have been carried out. The fuel nitrogen distribution between pyrolysis gas, tar, and char has been analyzed, as well as the ash composition, and, thus, the release of mineral components during pyrolysis.

  11. Direct use of methane in coal liquefaction

    DOEpatents

    Sundaram, M.S.; Steinberg, M.

    1985-06-19

    This invention relates to a process for converting solid carbonaceous material, such as coal, to liquid and gaseous hydrocarbons utilizing methane, generally at a residence time of about 20 to 120 minutes at a temperature of 250 to 750/sup 0/C, preferably 350 to 450/sup 0/C, pressurized up to 6000 psi, and preferably in the 1000 to 2500 psi range, preferably directly utilizing methane 50 to 100% by volume in a mix of methane and hydrogen. A hydrogen donor solvent or liquid vehicle such as tetralin, tetrahydroquinoline, piperidine, and pyrolidine may be used in a slurry mix where the solvent feed is 0 to 100% by weight of the coal or carbonaceous feed. Carbonaceous feed material can either be natural, such as coal, wood, oil shale, petroleum, tar sands, etc., or man-made residual oils, tars, and heavy hydrocarbon residues from other processing systems. 1 fig.

  12. Direct use of methane in coal liquefaction

    DOEpatents

    Sundaram, Muthu S.; Steinberg, Meyer

    1987-01-01

    This invention relates to a process for converting solid carbonaceous material, such as coal, to liquid and gaseous hydrocarbons utilizing methane, generally at a residence time of about 20-120 minutes at a temperature of 250.degree.-750.degree. C., preferably 350.degree.-450.degree. C., pressurized up to 6000 psi, and preferably in the 1000-2500 psi range, preferably directly utilizing methane 50-100% by volume in a mix of methane and hydrogen. A hydrogen donor solvent or liquid vehicle such as tetralin, tetrahydroquinoline, piperidine, and pyrolidine may be used in a slurry mix where the solvent feed is 0-100% by weight of the coal or carbonaceous feed. Carbonaceous feed material can either be natural, such as coal, wood, oil shale, petroleum, tar sands, etc., or man-made residual oils, tars, and heavy hydrocarbon residues from other processing systems.

  13. Itching for Allergy Relief?

    MedlinePlus

    ... Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Archived Content The content on ... National Allergy Bureau More in Consumer Updates Animal & Veterinary Children's Health Cosmetics Dietary Supplements Drugs Food Medical ...

  14. Dust Mite Allergy

    MedlinePlus

    ... mite allergy symptoms caused by inflammation of nasal passages include: Sneezing Runny nose Itchy, red or watery ... system produces an inflammatory response in your nasal passages or lungs. Prolonged or regular exposure to the ...

  15. Food allergies (image)

    MedlinePlus

    ... upon subsequent exposure to the substance. An actual food allergy, as opposed to simple intolerance due to the lack of digesting enzymes, is indicated by the production of antibodies to the food allergen, and by the release of histamines and ...

  16. Allergies and Hay Fever

    MedlinePlus

    ... Flowering plants rarely cause allergy symptoms. Often fragrant flowers are blamed for the uncomfortable symptoms, yet they ... you should talk to your ENT doctor to make sure they are safe. Some patients do better ...

  17. Ready for Spring Allergies?

    MedlinePlus

    ... to manage symptoms that come with a high pollen count, allergists say To use the sharing features ... seasonal allergies how they prepared for the high pollen counts that come with warmer weather. The survey ...

  18. Fire Ant Allergy

    MedlinePlus

    ... Serious Reaction For people with fire ant allergy, stings may cause a life-threatening reaction called anaphylaxis ( ... Fire ants bite with their jaws while they sting. This allows them to pull the stinger out, ...

  19. NICKEL ALLERGY: Surgeons Beware.

    PubMed

    Axe, Jeremie M; Sinz, Nathan J; Axe, Michael J

    2015-06-01

    When performing an orthopaedic device implantation, it should be routine practice for the surgeon to ask the patient if he or she has a metal allergy, and more specifically a nickel allergy. Ask the patient about costume jewelry or button reactions. If it is an elective surgery, obtain a confirmatory test with the aid of a dermatologist or allergist. It is recommended to use a non-nickel implant if the surgery is urgent, the patient has a confirmed allergy, or the patient does not want to undergo testing, as these implants are readily available in 2015. Finally, if the patient has a painful joint arthroplasty and all other causes have been ruled out, order a metal allergy test to aid in diagnosis.

  20. 7 CFR 3201.76 - Asphalt and tar removers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

  1. 7 CFR 3201.76 - Asphalt and tar removers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

  2. Food Allergy in Children

    PubMed Central

    Shenassa, M. Medhi

    1988-01-01

    The purpose of this review is to establish a rational approach to the assessment of children with food allergy related to an immunologic state in which alteration of response to antigenic material has developed after repeated exposure. The author offers a practical approach to the problem of food allergy in children, dispels some of the myths surrounding the disorder, and discusses some of the popular but unproven and controversial practices relating to its management. PMID:21253178

  3. Allergy in severe asthma.

    PubMed

    Del Giacco, S R; Bakirtas, A; Bel, E; Custovic, A; Diamant, Z; Hamelmann, E; Heffler, E; Kalayci, Ö; Saglani, S; Sergejeva, S; Seys, S; Simpson, A; Bjermer, L

    2017-02-01

    It is well recognized that atopic sensitization is an important risk factor for asthma, both in adults and in children. However, the role of allergy in severe asthma is still under debate. The term 'Severe Asthma' encompasses a highly heterogeneous group of patients who require treatment on steps 4-5 of GINA guidelines to prevent their asthma from becoming 'uncontrolled', or whose disease remains 'uncontrolled' despite this therapy. Epidemiological studies on emergency room visits and hospital admissions for asthma suggest the important role of allergy in asthma exacerbations. In addition, allergic asthma in childhood is often associated with severe asthma in adulthood. A strong association exists between asthma exacerbations and respiratory viral infections, and interaction between viruses and allergy further increases the risk of asthma exacerbations. Furthermore, fungal allergy has been shown to play an important role in severe asthma. Other contributing factors include smoking, pollution and work-related exposures. The 'Allergy and Asthma Severity' EAACI Task Force examined the current evidence and produced this position document on the role of allergy in severe asthma. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Biological detoxification of tar-water.

    PubMed

    Jansen, J la C; Jönsson, K; Hagman, M

    2002-01-01

    Gasification is an important option for the swift implementation of biomass combined heat and power processes in the Danish energy supply system. Tar-water produced by the gas-cleaning system of gasifiers may contain substances toxic to nitrifying bacteria. As the gasification plants are small and often located in the catchment area of small wastewater treatment plants, discharge of the tar-water may be critical for wastewater treatment plants operated with nitrogen removal. Tar-water from a full-scale updraft gasifier has been thoroughly examined with respect to inhibition of nitrification and the toxicity for nitrifying bacteria has been evaluated for the dominating constituents in the tar-water. Simple organic substances make up the dominating part of the organic matter but phenol and phenolic compounds are also present in significant concentrations. The identified substances are biologically degradable and it has been demonstrated that most of the organic matter together with the toxicity can be eliminated in an aerobic activated sludge process.

  5. Treating Allergies, Hay Fever, and Hives

    MedlinePlus

    ... other allergies. Newer drugs include Allegra, Claritin, Clarinex, Zyrtec, and Xyzal. They are available as generics and ... drugs (Benadryl Allergy, Chlor-Trimeton Allergy, Dimetapp Allergy). Cetirizine tablets Loratadine tablets, dissolving tablets, and liquid • The ...

  6. Not all shellfish "allergy" is allergy!

    PubMed Central

    2011-01-01

    The popularity of shellfish has been increasing worldwide, with a consequent increase in adverse reactions that can be allergic or toxic. The approximate prevalence of shellfish allergy is estimated at 0.5-2.5% of the general population, depending on degree of consumption by age and geographic regions. The manifestations of shellfish allergy vary widely, but it tends to be more severe than most other food allergens. Tropomyosin is the major allergen and is responsible for cross-reactivity between members of the shellfish family, particularly among the crustacea. Newly described allergens and subtle differences in the structures of tropomyosin between different species of shellfish could account for the discrepancy between in vitro cross-antigenicity and clinical cross-allergenicity. The diagnosis requires a thorough medical history supported by skin testing or measurement of specific IgE level, and confirmed by appropriate oral challenge testing unless the reaction was life-threatening. Management of shellfish allergy is basically strict elimination, which in highly allergic subjects may include avoidance of touching or smelling and the availability of self-administered epinephrine. Specific immunotherapy is not currently available and requires the development of safe and effective protocols. PMID:22410209

  7. Kiwi fruit allergy: a review.

    PubMed

    Lucas, Jane S A; Lewis, Stella A; Hourihane, Jonathan O'B

    2003-12-01

    Allergy to kiwi fruit was first described in 1981, and there have since been reports of the allergy presenting with a wide range of symptoms from localized oral allergy syndrome (OAS) to life-threatening anaphylaxis. The article reviews the available information concerning the clinical features of kiwi fruit allergy and the role of clinical investigations for diagnosis. Work identifying the major allergens in kiwi fruit has resulted in conflicting results, the possible reasons for which are discussed. The clinical associations of kiwi fruit allergy with allergies to pollens or latex are reviewed.

  8. Forensic assessment of polycyclic aromatic hydrocarbons at the former Sydney Tar Ponds and surrounding environment using fingerprint techniques.

    PubMed

    MacAskill, N Devin; Walker, Tony R; Oakes, Ken; Walsh, Margaret

    2016-05-01

    Polycyclic aromatic hydrocarbons (PAHs) were assessed spatially and temporally within and adjacent to a former coking and steel manufacturing facility in Sydney, Nova Scotia, Canada. Concentrations of PAHs were measured in surface soils, marine and estuary sediments prior to and during remediation of the Sydney Tar Ponds (STPs) site which was contaminated by nearly a century of coking and steel production. Previous studies identified PAHs in surficial marine sediments within Sydney Harbour, which were considered to be derived from STP discharges. Numerous PAH fingerprint techniques (diagnostic ratios, principal component analysis, quantitative and qualitative analysis) were applied to soil and sediment samples from the STPs and surrounding area to identify common source apportionment of PAHs. Results indicate coal combustion (from historical residential, commercial and industrial uses) and coal handling (from historic on-site stockpiling and current coal transfer and shipment facilities) are likely the principal source of PAHs found in urban soils and marine sediments, consistent with current and historical activities near these sites. However, PAH fingerprints associated with STP sediments correlated poorly with those of urban soils and marine sediments, but were similar to coal tar, historically consistent with by-products produced by the former coking operations. This study suggests PAH contamination of Sydney Harbour sediments and urban soils is largely unrelated to historic coking operations or recent remediation of the STPs site, but rather a legacy of extensive use of coal for a variety of activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Atmospheric tar balls: aged primary droplets from biomass burning?

    NASA Astrophysics Data System (ADS)

    Tóth, A.; Hoffer, A.; Nyirő-Kósa, I.; Pósfai, M.; Gelencsér, A.

    2013-12-01

    Atmospheric tar balls are particles of special morphology and composition that are abundant in the plumes of biomass smoke. These particles form a specific subset of brown carbon (BrC) which has been shown to play a significant role in atmospheric shortwave absorption and thus climate forcing. Formerly tar balls were hypothesized to be formed in secondary processes in the atmosphere from lignin pyrolysis products. Based on their typical size distributions, morphology, chemical characteristics and other features we now suggest that tar balls are initially produced by the emission of primary tar droplets upon biomass burning. To verify our hypothesis tar balls were produced under laboratory conditions with the total exclusion of flame processes. An all-glass apparatus was designed and tar ball particles were generated from liquid tar obtained previously by dry distillation of wood. The size range, morphology and the chemical composition of the laboratory-generated tar ball particles were similar to those observed in biomass smoke plumes or elsewhere in the atmosphere. Based on our results and the chemical and physical characteristics of tar we suggest that tar balls can be formed by the chemical transformation of emitted primary tar droplets.

  10. Allergy and orthodontics

    PubMed Central

    Chakravarthi, Sunitha; Padmanabhan, Sridevi; Chitharanjan, Arun B.

    2012-01-01

    The aim of this paper is to review the current literature on allergy in orthodontics and to identify the predisposing factors and the implications of the allergic reaction in the management of patients during orthodontic treatment. A computerized literature search was conducted in PubMed for articles published on allergy in relation to orthodontics. The MeSH term used was allergy and orthodontics. Allergic response to alloys in orthodontics, particularly nickel, has been extensively studied and several case reports of nickel-induced contact dermatitis have been documented. Current evidence suggests that the most common allergic reaction reported in orthodontics is related to nickel in orthodontic appliances and allergic response is more common in women due to a previous sensitizing exposure from nickel in jewellery. Studies have implicated allergy in the etiology of hypo-dontia. It has also been considered as a high-risk factor for development of extensive root resorption during the course of orthodontic treatment. This review discusses the relationship and implications of allergy in orthodontics. PMID:24987632

  11. Milk and Soy Allergy

    PubMed Central

    Kattan, Jacob D.; Cocco, Renata R.; Järvinen, Kirsi M.

    2011-01-01

    SYNOPSIS Cow’s milk allergy (CMA) affects 2% to 3% of young children and presents with a wide range of immunoglobulin E (IgE-) and non-IgE-mediated clinical syndromes, which have a significant economic and lifestyle impact. Definitive diagnosis is based on a supervised oral food challenge (OFC), but convincing clinical history, skin prick testing, and measurement of cow’s milk (CM)-specific IgE can aid in the diagnosis of IgE-mediated CMA and occasionally eliminate the need for OFCs. It is logical that a review of CMA would be linked to a review of soy allergy, as soy formula is often an alternative source of nutrition for infants who do not tolerate cow’s milk. The close resemblance between the proteins from soy and other related plants like peanut, and the resulting cross-reactivity and lack of predictive values for clinical reactivity, often make the diagnosis of soy allergy far more challenging. This review examines the epidemiology, pathogenesis, clinical features, natural history and diagnosis of cow’s milk and soy allergy. Cross-reactivity and management of milk allergy are also discussed. PMID:21453810

  12. Lettuce contact allergy.

    PubMed

    Paulsen, Evy; Andersen, Klaus E

    2016-02-01

    Lettuce (Lactuca sativa L.) and its varieties are important vegetable crops worldwide. They are also well-known, rarely reported, causes of contact allergy. As lettuce allergens and extracts are not commercially available, the allergy may be underdiagnosed. The aims of this article are to present new data on lettuce contact allergy and review the literature. Lettuce is weakly allergenic, and occupational cases are mainly reported. Using aimed patch testing in Compositae-allergic patients, two recent Danish studies showed prevalence rates of positive lettuce reactions of 11% and 22%. The majority of cases are non-occupational, and may partly be caused by cross-reactivity. The sesquiterpene lactone mix seems to be a poor screening agent for lettuce contact allergy, as the prevalence of positive reactions is significantly higher in non-occupationally sensitized patients. Because of the easy degradability of lettuce allergens, it is recommended to patch test with freshly cut lettuce stem and supplement this with Compositae mix. As contact urticaria and protein contact dermatitis may present as dermatitis, it is important to perform prick-to-prick tests, and possibly scratch patch tests as well. Any person who is occupationally exposed to lettuce for longer periods, especially atopics, amateur gardeners, and persons keeping lettuce-eating pets, is potentially at risk of developing lettuce contact allergy. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Fish allergy: in review.

    PubMed

    Sharp, Michael F; Lopata, Andreas L

    2014-06-01

    Globally, the rising consumption of fish and its derivatives, due to its nutritional value and divergence of international cuisines, has led to an increase in reports of adverse reactions to fish. Reactions to fish are not only mediated by the immune system causing allergies, but are often caused by various toxins and parasites including ciguatera and Anisakis. Allergic reactions to fish can be serious and life threatening and children usually do not outgrow this type of food allergy. The route of exposure is not only restricted to ingestion but include manual handling and inhalation of cooking vapors in the domestic and occupational environment. Prevalence rates of self-reported fish allergy range from 0.2 to 2.29 % in the general population, but can reach up to 8 % among fish processing workers. Fish allergy seems to vary with geographical eating habits, type of fish processing, and fish species exposure. The major fish allergen characterized is parvalbumin in addition to several less well-known allergens. This contemporary review discusses interesting and new findings in the area of fish allergy including demographics, novel allergens identified, immunological mechanisms of sensitization, and innovative approaches in diagnosing and managing this life-long disease.

  14. Allergies and Hyperactivity (and sugar)

    MedlinePlus

    ... AAP Find a Pediatrician Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions ... Vaccine Preventable Diseases Healthy Children > Health Issues > Conditions > ADHD > Allergies and Hyperactivity Health Issues Listen Español Text ...

  15. Seasonal Allergies: Diagnosis, Treatment & Research

    MedlinePlus

    ... turn JavaScript on. Feature: Seasonal Allergies Diagnosis, Treatment & Research Past Issues / Spring 2015 Table of Contents Diagnosis ... Asthma exacerbation Sinus infection Asthma exacerbation Seasonal Allergy Research at NIH Asthma and Allergic Diseases Cooperative Research ...

  16. Allergy and Asthma Health Magazine

    MedlinePlus

    ... Of Age Older Adults Allergy and Asthma Health Magazine Women Infant, Children and Teenagers Living With Lung ... written by Respiratory Experts Like no other health magazine, Allergy & Asthma Health Magazine is published by people ...

  17. Strength of pitch-bonded coal briquets as influenced by the preparation method

    SciTech Connect

    Zorina, E.I.; Romanov, Yu.A.; Glushankov, S.L.

    1992-05-20

    Briquetting technology is widely used in metallurgical production, fuel-based energetic, coal-tar chemistry, and commercial production of activated carbons. Strong, dense molded materials with comparatively low contents of molden binder can be obtained by pressing at relatively low pressures. As objects of investigation the authors selected coals from the Kuznetsk Basin, representing different stages of metamorphism and a medium-temperature coal-tar pitch (MTP) from the Nizhnii Tagil Metallurgical Combine (ring-and-ball softening point 72{degrees}C). 6 refs., 4 figs., 1 tab.

  18. Thermodynamic properties of pulverized coal during rapid heating devolatilization processes

    SciTech Connect

    Proscia, W.M.; Freihaut, J.D.

    1993-03-01

    Knowledge of the thermodynamic and morphological properties of coal associated with rapid heating decomposition pathways is essential to progress in coal utilization technology. Specifically, knowledge of the heat of devolatilization, surface area and density of coal as a function of rank characteristics, temperature and extent of devolatilization in the context of rapid heating conditions is required both, for the fundamental determination of kinetic parameters of coal devolatilization, and to refine existing devolatilization sub-models used in comprehensive coal combustion codes. The objective of this research is to obtain data on the thermodynamic properties and morphology of coal under conditions of rapid heating. Specifically, the total heat of devolatilization, external surface area, BET surface area and true density will be measured for representative coal samples. In addition, for one coal, the contribution of each of the following components to the overall heat of devolatilization will be measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Calibration of the heated grid calorimeter (Task 2) was completed this reporting period. Several refinements to the heated grid apparatus have been implemented which allow quantitative determination of sample heat capacity at high heating rates.

  19. Peanut allergy and anaphylaxis

    PubMed Central

    Finkelman, Fred D.

    2010-01-01

    Summary Peanuts are a frequent cause of food allergy and the most common cause of fatal food-induced anaphylaxis in the U.S. Advances during the past two years have promoted our understanding of peanut allergens and peanut allergy prevalence, etiology, diagnosis and therapy. The advances highlighted in this review include evidence that the peanut allergens most important in disease differ in different parts of the world, that early oral exposure to peanuts may decrease the frequency of peanut allergy, while early non-oral exposure may have the opposite effect, that complement activation by peanut constituents appears to promote peanut-induced anaphylaxis and that oral immunotherapy, anti-IgE antibody and an herbal formulation are promising approaches for treatment of this disorder. PMID:21051210

  20. Determinants of Food Allergy

    PubMed Central

    Masilamani, Madhan; Commins, Scott; Shreffler, Wayne

    2012-01-01

    SUMMARY Much has been learned by identifying the molecules that can be recognized by IgE from patients with allergies. Increasingly, by correlating patterns of sensitization with clinical features, it has become possible to distinguish molecules responsible for primary sensitization (complete allergens) from those that are more likely cross-reactive targets. In the case of animal allergens, evolutionary distance seems to be an important factor in determining allergenicity. However, until more is understood regarding the mechanistic details of primary sensitization, including the participation of molecules that stimulate innate immune responses and the repertoire of T-cell antigens, molecules that may or may not themselves be important B-cell antigens, we will not be able to explain fundamental questions, such as why peanut allergy is more severe than soy allergy or why tick exposure is associated with clinically relevant sensitization to a carbohydrate epitope. PMID:22244230

  1. Viral infections and allergies.

    PubMed

    Xepapadaki, Paraskevi; Papadopoulos, Nikolaos G

    2007-01-01

    Respiratory viral infections have been implicated in the origin of, protection from and exacerbation of allergy-related symptoms in a variety of ways. Viral infections are closely linked to infantile wheezing. Severe bronchiolitis in early infancy may predispose to chronic childhood asthma as well as allergic sensitization; alternatively it could represent a marker of susceptible individuals. In contrast, repeated mild infections in early life may have a protective role in the development of asthma or atopy by driving the immune system towards Th1 responses. However, evidence on this hypothesis is not consistent as far as respiratory viruses are concerned. Several factors, including the presence of an atopic environment, timing of exposure and severity of the infection, interactively contribute to the allergy-infection relationship. In the present report, recent data on the role of viral infections in the development and progression of allergy and asthma are reviewed.

  2. [Atopic dermatitis and allergy].

    PubMed

    Karila, C

    2013-08-01

    Atopic dermatitis (AD) is a very common chronic inflammatory skin disease in childhood, often the first step in the atopic march. It seems justified to look for a food or a respiratory allergy, being worsening or responsible for the AD. At infant age, some clinical features are consistent with a food allergy: a severe AD, with an early onset, uncontrolled by topical corticosteroids, and a history of immediate-type reactions. As sensitization to food allergens is very common (positive skin prick-test, atopy patch-test or specific IgE), the role of food allergens in worsening AD is difficult to affirm. So, it could be necessary to ask the advice of an allergist, to avoid unnecessary elimination diets. At older age, exposure to aeroallergens cans worsen AD. Looking for an aeroallergen allergy can help to choose the specific immunotherapy, which clinical efficacy on AD seems interesting.

  3. Food allergy in children.

    PubMed

    Baral, V R; Hourihane, J O'B

    2005-11-01

    Food allergy is being increasingly recognised with the highest prevalence being in preschool children. Pathogenesis varies so diagnosis rests on careful history and clinical examination, appropriate use of skin prick and serum-specific IgE testing, food challenge, and supervised elimination diets. A double blind placebo controlled food challenge is the gold standard diagnostic test. Avoidance of the allergenic food is the key towards successful management. IgE mediated food allergy may present as a potentially fatal anaphylactic reaction, and management consists of the appropriate use of adrenaline (epinephrine) and supportive measures. Sensitisation remains a key target for intervention. Disease modifying agents are currently under trial for managing difficult allergies. Management requires a multidisciplinary approach and follow up.

  4. All about Allergies (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old All About Allergies KidsHealth > For Parents > All About Allergies A A A What's in this ... children might have allergies doesn't mean that all of your kids will definitely get them, too. ...

  5. Physician Requirements-1990. For Allergy.

    ERIC Educational Resources Information Center

    Thorner, Robert N.; Rudzinski, Karen

    Professional requirements for physicians specializing in allergy were estimated to assist policymakers in developing guidelines for graduate medical education. In estimating service requirements for allergy, an allergy Delphi panel reviewed reference and incidence-prevalence and utilization data for 21 conditions that affect the ambulatory care…

  6. Nigeria to step up tar sands activity

    SciTech Connect

    Not Available

    1987-03-01

    The Nigerian government has directed its Ministry of Mines, Power and Steel to assume responsibility for the exploration and exploitation of tar sands deposits in Bendel, Ondo and Oyo States. The directive resulted from a survey report by the University of Ife's geological consultancy unit on bituminous sand deposits in the area. The statement said the government was satisfied that there were large commercial quantities of the sands in the three states. The survey had reported that Nigeria could recover between 31 and 40 billion barrels of heavy crude from the tar sand deposits. Exploration for hydrocarbons is currently going on in Anambra and Lake Chad basins as well as the Benue Trough. Apart from the Nigerian National Petroleum Corporation, Shell Petroleum and Gulf Oil have begun exploration activities in the Ondo area. Meanwhile, Nigeria has had to import heavy crude from Venezuela, for processing at the Kaduna refinery.

  7. Indoor and Outdoor Allergies.

    PubMed

    Singh, Madhavi; Hays, Amy

    2016-09-01

    In last 30 to 40 years there has been a significant increase in the incidence of allergy. This increase cannot be explained by genetic factors alone. Increasing air pollution and its interaction with biological allergens along with changing lifestyles are contributing factors. Dust mites, molds, and animal allergens contribute to most of the sensitization in the indoor setting. Tree and grass pollens are the leading allergens in the outdoor setting. Worsening air pollution and increasing particulate matter worsen allergy symptoms and associated morbidity. Cross-sensitization of allergens is common. Treatment involves avoidance of allergens, modifying lifestyle, medical treatment, and immunotherapy.

  8. [About animal allergy].

    PubMed

    Haahtela, Tari

    2016-01-01

    Although the opinions about animals and animal allergies may be extreme, animals can even be indispensable for the well-being of humans. The immune tolerance of many modern city dwellers is insufficiently developed, predisposing the skin and mucous membranes to allergic inflammation. There is no need in infancy to avoid animals, and animal contacts in early childhood rather protect from the development of allergies. Pet allergens are present in small amounts everywhere, not only in places where they live. General instructions on avoidance do not exist. New forms of desensitization therapy may in the future bring relief for those having strong symptoms.

  9. Aspects of tar sands development in Nigeria

    SciTech Connect

    Adewusi, V.A. )

    1992-07-01

    Development of Nigerian massive reserves of crude bitumen and associated heavy oil is imminent in view of the impacts that the huge importation of these materials and their products have on the nation's economy, coupled with the depleting reserves of Nigeria and highlights the appropriate production technology options and their environmental implications. The utilization potentials of these resources are also enumerated, as well as the government's role in achieving accelerated, long-term tar sands development in the country.

  10. Effects of biodegradation upon porphyrin biomarkers in Upper Mississippian tar sands and related oils, southern Oklahoma

    SciTech Connect

    Michael, G.E.

    1987-05-01

    Organic molecules present in oils which show a structural relationship to their biological precursors are referred to as biomarkers. These compounds are becoming widely used in oil exploration for making oil-oil, oil-source rock correlations and undertaking maturation and migration studies in basin analysis. Treibs first discovered the presence of porphyrins in oils, shales, and coals over 50 years ago. Porphyrins are predominantly derived from chlorophyll precursors present in plants and bacteria. Studies of changes in porphyrin distributions with increasing maturation due to the effects of increased time of burial and temperature have been performed. However, little is known as to how their distributions change with migration, biodegradation, or water washing of oils. In the present study, 16 tar sand samples were extracted from drill core at depths ranging from 16 to 256 ft obtained from a tar sand quarry in the Ardmore basin, Carter County, Oklahoma. Surrounding oil samples and possible source rocks have also been analyzed to determine the source of the oil in the tar sands. The effects of biodegradation on the porphyrin distributions can be discerned from the effects of migration and maturation by comparing other biomarker distributions within the sands, related oils, and suspected source rocks. Biodegradation of the tar sand samples can be observed within the alkane and other biomarker distributions. The relative effects of biodegradation on biomarkers such as alkanes, steranes, and terpanes have been well documented. By using this information, it is possible to determine the extent of biodegradation or water washing necessary to alter the porphyrin distributions.

  11. Mineralogy and geochemistry of a uraniferous coal from the Red Desert Area, Sweetwater County, Wyoming

    USGS Publications Warehouse

    Breger, Irving A.; Deul, Maurice; Meyrowitz, Robert; Rubinstein, Samuel

    1953-01-01

    A sample of subbituminous uraniferous coal from the Red Desert, Sweetwater County, Wyo., was studied mineralogically. The coal contains gypsum (6 percent), kaolinite (1 percent), quartz (0.3 percent), calcite (trace), and limonite (trace). This suite of minerals and the absence of pyrite show that the coal has been subjected to weathering and oxidation. No uranium minerals have been found; mechanical fractionation has indicated that the uranium is associated with the organic constituents of the coal. The minerals that have been isolated contain 0.0006 percent uranium, a content which is to be expected for nonuraniferous sedimentary rocks. The organic components of the coal contain approximately 0.002 percent uranium. On the basis of material balance calculations, the organic components carry 98 percent of the uranium in the coal. Fischer assays of this weathered coal from the Red Desert indicate a yield of 16.7 gallons of tar per ton on low-temperature retorting. In view of the large reserve of subbituminous coal in the Red Desert, its probable ease of mining, and its tar yield, it may be desirable to carry out further evaluation of the coal as a fuel or raw material for the manufacture of tar or chemicals. If economic factors permit utilization of the coal, the uranium, although present in small percentages, could be recovered as a byproduct.

  12. Molecular Mechanisms of Nickel Allergy

    PubMed Central

    Saito, Masako; Arakaki, Rieko; Yamada, Akiko; Tsunematsu, Takaaki; Kudo, Yasusei; Ishimaru, Naozumi

    2016-01-01

    Allergic contact hypersensitivity to metals is a delayed-type allergy. Although various metals are known to produce an allergic reaction, nickel is the most frequent cause of metal allergy. Researchers have attempted to elucidate the mechanisms of metal allergy using animal models and human patients. Here, the immunological and molecular mechanisms of metal allergy are described based on the findings of previous studies, including those that were recently published. In addition, the adsorption and excretion of various metals, in particular nickel, is discussed to further understand the pathogenesis of metal allergy. PMID:26848658

  13. Allergy-Friendly Gardening

    MedlinePlus

    ... gardening may also help reduce symptoms. Certain flowers, trees and grasses are better suited for the gardens ... people with outdoor allergies. These include: • Cactus • Cherry tree • Dahlia • Daisy • Geranium • Hibiscus • Iris • Magnolia • Roses • Snapdragon • ...

  14. [Immunology of contact allergy].

    PubMed

    Martin, S F

    2011-10-01

    Contact allergy is a skin disease that is caused by the reaction of the immune system to low molecular weight chemicals. A hallmark of contact allergens is their chemical reactivity, which is not exhibited by toxic irritants. Covalent binding of contact allergens to or complex formation with proteins is essential for the activation of the immune system. As a consequence antigenic epitopes are formed, which are recognized by contact allergen-specific T cells. The generation of effector and memory T cells causes the high antigen specificity and the repeated antigen-specific skin reaction of contact allergy. New findings reveal that the less specific reaction of the innate immune system to contact allergens closely resembles the reaction to an infection. Therefore, contact allergy can be viewed as an immunologic misunderstanding since the skin contact with chemical allergens is interpreted as an infection. The growing understanding of the molecular and cellular pathologic mechanisms of contact allergy can aid the development of specific therapies and of in vitro alternatives to animal testing for the identification of contact allergens.

  15. Going Nuts over Allergies

    ERIC Educational Resources Information Center

    Munoz-Furlong, Anne

    2006-01-01

    Some 600,000 children in the US are allergic to peanuts. Of 400 elementary school nurses, 44% cite increased food-allergic students in the past five years. Peanut allergy doubled in children from 1997 to 2002, and yet peanuts are only one of six foods most often causing allergic reactions in children, including milk, eggs, wheat, soy, and tree…

  16. Going Nuts over Allergies

    ERIC Educational Resources Information Center

    Munoz-Furlong, Anne

    2006-01-01

    Some 600,000 children in the US are allergic to peanuts. Of 400 elementary school nurses, 44% cite increased food-allergic students in the past five years. Peanut allergy doubled in children from 1997 to 2002, and yet peanuts are only one of six foods most often causing allergic reactions in children, including milk, eggs, wheat, soy, and tree…

  17. Absorptive removal of biomass tar using water and oily materials.

    PubMed

    Phuphuakrat, Thana; Namioka, Tomoaki; Yoshikawa, Kunio

    2011-01-01

    Water is the most common choice of absorption medium selected in many gasification systems. Because of poor solubility of tar in water, hydrophobic absorbents (diesel fuel, biodiesel fuel, vegetable oil, and engine oil) were studied on their absorption efficiency of biomass tar and compared with water. The results showed that only 31.8% of gravimetric tar was removed by the water scrubber, whereas the highest removal of gravimetric tar was obtained by a vegetable oil scrubber with a removal efficiency of 60.4%. When focusing on light PAH tar removal, the absorption efficiency can be ranked in the following order; diesel fuel>vegetable oil>biodiesel fuel>engine oil>water. On the other hand, an increase in gravimetric tar was observed for diesel fuel and biodiesel fuel scrubbers because of their easy evaporation. Therefore, the vegetable oil is recommended as the best absorbent to be used in gasification systems.

  18. Catalytic destruction of tars in biomass-derived gases

    SciTech Connect

    Mudge, L K; Baker, E G; Brown, M D; Wilcox, W A

    1988-02-01

    The Biomass and Municipal Waste Technology Division of the US Department of Energy is sponsoring studies at the Pacific Northwest Laboratory on catalytic destruction of condensible hydrocarbons (tars) in biomass-derived gases. Currently gasifiers generate a significant amount of tars in the product gases. These tars create problems with plugging in downstream equipment and with wastewater treatment. Partial oxidation of the gas stream in a secondary fluid bed of catalyst destroys the tars in biomass-derived gases while increasing the energy content of the product gas by over 20%. Catalysts that remain active for tar destruction are used in the secondary reactor which is specially designed to promote destruction of tars and minimize oxidation of combustible gases such as CO and H/sub 2/. Results of studies with different catalysts which have been tested for this application are described.

  19. Investigation of the rank dependence of tar evolution. Quarterly report, 1 July 1990--30 September 1990

    SciTech Connect

    Freihaut, J.D.; Proscia, W.M.

    1990-12-31

    Despite its high nitrogen concentration levels relative to the parent coal samples, 7.2% vs. 1.4 - 2.0%, little volatile nitrogen evolution is observed until decomposition temperatures of 600{degree}C or greater are obtained. Due to the lack of decomposition via tar evolution and as contrasted to parent coals, no significant bound nitrogen is evolved with heavy hydrocarbons at particle temperatures less than 600{degree}C. Similar to ``virgin`` chars and tars formed during rapid devolatilization, the polyimide samples begin to evolve significant fractions of bound nitrogen as IR-active light gases at particle temperatures between 650 and 750{degree}C. Unlike coal samples, however, relatively large fractions of the light gases are observed to be ammonia. The IR-active, nitrogen-containing light gas evolution rapidly declines at polyimide char temperatures greater than 750{degree}C, again in contrast to observed behavior in virgin coal char samples. It is not certain if the nitrogen evolution kinetics changes from selectively forming ammonia and hydrogen cyanide to benzonitriles or free nitrogen at these temperatures. The light gas evolution pattern with decomposition temperature of polymide could contribute to our understanding of the low conversion efficiencies observed for bound nitrogen to NO{sub x} conversion in the char combustion phase of pfc combustion.

  20. Environmentally Friendly Cleaners for Removing Tar from Metal Surfaces

    DTIC Science & Technology

    2009-04-01

    724) 656-0757 info@eacochem.com C-Tar Melt Petroleum Hydrocarbon, Ethylene glycol n-butyl ether Safe for wood, metal, masonry 10 EcoLink...Remover Petroleum Distillates, Ethylene Glycol Monobutyl-Ether Removes tar from vehicles. 16 Petroferm, Inc. 2416 Lynndale Road · Fernandina Beach...MN 55432 800-373-0633 Fax 763-571-1819 Sentinel 700 Refined Petroleum Solvents Ethylene Glycol Monobutyl Ether Removes tar & asphalt from met- als

  1. Probiotics and allergy.

    PubMed

    Furrie, Elizabeth

    2005-11-01

    Allergy is caused by an immune reaction that is out of all proportion to the antigenic stimuli. Classical allergy is a type I hypersensitivity reaction mediated by the interaction of mast cells (and eosinophils) coated with allergen-specific IgE and a cross-linking allergen. The physiological outcome is inflammation commonly displayed by urticaria, rhinitis, vomiting and diarrhoea, depending on the route of allergen entry. In extreme reactions anaphylactic shock can result that may lead to death. Chronic allergic responses most commonly present themselves as asthma and eczema. All these symptoms are the consequence of an imbalanced immune system making an unsuitable response to an environmental or food antigen. On bacterial colonisation of the colon after birth the appropriate microbiological stimuli is essential to redress the balance of the skewed T-helper 2 immune response present in the newborn. This normal interaction between baby and microbes is thought to be compromised in the Western world, with a reduction in bifidobacteria and an increase in clostridial species, particularly in bottle-fed infants. The use of probiotic therapy to prevent allergic disease has been demonstrated in two studies using a probiotic Lactobacillus rhamnosus GG in neonates. A long-term reduction in allergy has been shown in the test group, with lactobacillus reducing the incidence of atopic eczema. Management of allergy through probiotics has also been demonstrated in infants, using lactobacilli to control atopic eczema and cow's milk allergy. Unfortunately, these positive results have not been repeated in studies with older children and young adults.

  2. Mobilization of Manufactured Gas Plant Tar with Alkaline Flushing Solutions

    PubMed Central

    Hauswirth, Scott C.; Birak, Pamela Schultz; Rylander, Seth C.; Miller, Cass T.

    2011-01-01

    This experimental study investigates the use of alkaline and alkaline-polymer solutions for the mobilization of former manufactured gas plant (FMGP) tars. Tar-aqueous interfacial tensions (IFTs) and contact angles were measured, and column flushing experiments were conducted. NaOH solutions (0.01–1 wt.%) were found to significantly reduce tar-aqueous IFT. Contact angles indicated a shift to strongly water-wet, then to tar-wet conditions as NaOH concentration increased. Column experiments were conducted with flushing solutions containing 0.2, 0.35, and 0.5% NaOH, both with and without xanthan gum (XG). Between 10 and 44% of the residual tar was removed by solutions containing only NaOH, while solutions containing both NaOH and XG removed 81–93% of the tar with final tar saturations as low as 0.018. The mechanism responsible for the tar removal is likely a combination of reduced IFT, a favorable viscosity ratio, and tar bank formation. Such an approach may have practical applications and would be significantly less expensive than surfactant-based methods. PMID:22091957

  3. Evaluation of surfactant flushing for remediating EDC-tar contamination

    NASA Astrophysics Data System (ADS)

    Liang, Chenju; Hsieh, Cheng-Lin

    2015-06-01

    Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater.

  4. Evaluation of surfactant flushing for remediating EDC-tar contamination.

    PubMed

    Liang, Chenju; Hsieh, Cheng-Lin

    2015-01-01

    Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Process for clean-burning fuel from low-rank coal

    DOEpatents

    Merriam, Norman W.; Sethi, Vijay; Brecher, Lee E.

    1994-01-01

    A process for upgrading and stabilizing low-rank coal involving the sequential processing of the coal through three fluidized beds; first a dryer, then a pyrolyzer, and finally a cooler. The fluidizing gas for the cooler is the exit gas from the pyrolyzer with the addition of water for cooling. Overhead gas from pyrolyzing is likely burned to furnish the energy for the process. The product coal exits with a tar-like pitch sealant to enhance its safety during storage.

  6. Thermodynamic properties of pulverized coal during rapid heating devolatilization processes. Quarterly progress report, October--December 1993

    SciTech Connect

    Proscia, W.M.; Freihaut, J.D.

    1994-03-01

    The objective of this research is to obtain data on the thermodynamic properties and morphology of coal under conditions of rapid heating. Specifically, the total heat of devolatilization, external surface area, BET surface area and true density will be measured for representative coal samples. The coal ranks to be investigated will include a high volatile A bituminous (PSOC 1451D) and a low volatile bituminous (PSOC 1516D). An anthracite (PSOC 1468) will be used as a non-volatile coal reference. In addition, for one coal, the contribution of each of the following components to the overall heat of devolatilization will be measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars.

  7. Acid Tar Lagoons: Management and Recovery

    NASA Astrophysics Data System (ADS)

    Bohers, Anna; Hroncová, Emília; Ladomerský, Juraj

    2017-04-01

    This contribution presents the issue with possibility of definitive removal of dangerous environmental burden in Slovakia - serious historical problem of two acid tar lagoons. In relation to their removal, no technology has been found so far - technologically and economically suitable, what caused problems with its management. Locality Predajná is well known in Slovakia by its character of contrasts: it is situated in the picturesque landscape of National Park buffer zone of Nízke Tatry, on the other site it is contaminated by 229 211m3 of acid tar with its characteristics of toxicity, carcinogenicity, teratogenicity, mutagenicity and toxicity especially for animals and plants. Acid tar in two landfills with depth of 1m in case of the first lagoon and 9,5m in case of the second lagoon is a waste product derived from operation of Petrochema Dubová - refinery and petrochemical plant whose activity was to process the crude oil through processes of sulfonation and adsorption technology for producing lubricating and special oils, synthetic detergents and special white oils for cosmetic and medical purposes. A part of acid tar was incinerated in two incineration plats. Concentration of SO2 in combustion gases was too high and it was not possible to decrease it under the value of 2000 mg.mn-3 [LADOMERSKÝ, J. - SAMEŠOVÁ, D.: Reduction in sulfur dioxide emissions waste gases of incineration plant. Acta facultatis ecologiae. 1999, p. 217-223]. That is why it was necessary to put them out of operation. Later, because of public opposition it was not possible to build a new incineration plat corresponding to the state of the art. Even though actual Slovak and European legislative for protection of environment against such impacts, neither of tried methods - bio or non-biologic treatment methods - was proved as suitable for processing or for recovery in the reason of different factors admission: i.e. strong aggressivity, difficulty with handling because of its sludgy and

  8. [Cypress pollen allergy].

    PubMed

    Charpin, D; Calleja, M; Pichot, C; Penel, V; Hugues, B; Poncet, P

    2013-12-01

    Cypress belongs to the Cupressaceae family, which includes 140 species with non-deciduous foliage. The most important genera in allergic diseases are Cupressus sempervirens or Green cypress, Cupressus arizonica or Blue cypress, Juniperus oxycedrus, Juniperus communis and Thuya. Because J. oxycedrus pollinates in October, C. sempervirens in January and February, C. arizonica in February and March, J. communis in April, the symptomatic period is long-lasting. Because of global warming, the pollination period is tending to last longer and Cupressaceae species are becoming established further the north. In Mediterranean countries, cypress is by far the most important pollinating species, accounting for half of the total pollination. The major allergens belong to group 1. The other allergens from cypress and Juniper share 75 to 97 % structural homology with group 1 major allergens. The prevalence of cypress allergy in the general population ranges from 5 % to 13 %, according to exposure to the pollen. Among outpatients consulting an allergist, between 9 and 35 %, according to different studies, are sensitized to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy. Risk factors include a genetic predisposition and/or a strong exposure to pollen, but air pollutants could play a synergistic role. The study of the natural history of cypress allergy allows the identification of a subgroup of patients who have no personal or family history of atopy, whose disease began later in life, with low total IgE and often monosensitization to cypress pollen. In these patients, the disease is allergic than rather atopic. In the clinical picture, rhinitis is the most prevalent symptom but conjunctivitis the most disabling. A cross-reactivity between cypress and peach allergy has been demonstrated. The pharmacological treatment of cypress allergy is not different from

  9. The Australian tar derby: the origins and fate of a low tar harm reduction programme.

    PubMed

    King, W; Carter, S M; Borland, R; Chapman, S; Gray, N

    2003-12-01

    To document the development of the low tar harm reduction programme in Australia, including tobacco industry responses. Tobacco industry documents, retail tobacco journals, newspapers, medical journals, and Anti-Cancer Council of Victoria (ACCV) newsletters and archival records. Documents on the strategies and knowledge bases of the ACCV, other Australian health authorities, and the tobacco industry. The ACCV built a durable system for measuring and publicising the tar and nicotine yields of Australian cigarettes and influencing their development. The tobacco industry initially sought to block the development of this system but later appeared to cooperate with it, as is evidenced by the current market dominance of low tar brands. However, behind the scenes, the industry used its substantial knowledge advantage regarding compensatory smoking and its ability to re-engineer cigarettes to gain effective control of the system and subvert the ACCV's objectives. Replacement of the low tar programme with new means of minimising the harms from cigarette smoking should be a policy priority for the Australian government. This will require regulation, rather than further voluntary agreements, and stringent monitoring of successor programmes will be necessary.

  10. The Australian tar derby: the origins and fate of a low tar harm reduction programme

    PubMed Central

    King, W; Carter, S; Borland, R; Chapman, S; Gray, N

    2003-01-01

    Objective: To document the development of the low tar harm reduction programme in Australia, including tobacco industry responses. Data sources: Tobacco industry documents, retail tobacco journals, newspapers, medical journals, and Anti-Cancer Council of Victoria (ACCV) newsletters and archival records. Study selection: Documents on the strategies and knowledge bases of the ACCV, other Australian health authorities, and the tobacco industry. Results: The ACCV built a durable system for measuring and publicising the tar and nicotine yields of Australian cigarettes and influencing their development. The tobacco industry initially sought to block the development of this system but later appeared to cooperate with it, as is evidenced by the current market dominance of low tar brands. However, behind the scenes, the industry used its substantial knowledge advantage regarding compensatory smoking and its ability to re-engineer cigarettes to gain effective control of the system and subvert the ACCV's objectives. Conclusions: Replacement of the low tar programme with new means of minimising the harms from cigarette smoking should be a policy priority for the Australian government. This will require regulation, rather than further voluntary agreements, and stringent monitoring of successor programmes will be necessary. PMID:14645950

  11. Solvent extraction of Southern US tar sands

    SciTech Connect

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  12. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2 Prelease exploration within Special Tar Sand Areas. ...

  13. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2 Prelease exploration within Special Tar Sand Areas. ...

  14. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2 Prelease exploration within Special Tar Sand Areas. ...

  15. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2 Prelease exploration within Special Tar Sand Areas. ...

  16. The use of carbon and sulfur isotopes as correlation parameters for the source identification of beach tar in the southern California borderland

    NASA Astrophysics Data System (ADS)

    Hartman, Blayne; Hammond, Douglas E.

    1981-03-01

    Carbon and sulfur isotope ratios and total sulfur content are used to correlate beach tars depositing near Los Angeles with their probable sources. Analysis is confined strictly to the asphaltene fraction of petroleum owing to the insensitivity of this fraction to weathering processes. The δ 13C, δ 34S and % S of the asphaltene fraction of natural offshore seep oils range from -22.51 to -23.20%., +7.75 to + 15.01%. and 4.45 to 8.27%, respectively. Values for local offshore production wells overlapped those for the natural seepage, ranging from -22.10 to -22.85%., -2.96 to 13.90%., and 0.81 to 8.00%. Analytical values for these parameters show that tanker crudes imported into the area are not similar to the California oils. Analysis of the same parameters in beach tars collected during 1976-1977 indicates a close match with the potential source oils, thus it is concluded that these parameters are useful for identifying petroleum sources, even after 2-4 weeks of weathering. Results indicate that 55% of the tars in Santa Monica Bay are derived from natural oil seepage 150km to the northwest at Coal Oil Point, 26% are derived from natural oil seepage in Santa Monica Bay, and 19% are derived from unknown sources. Models of tar transport are inferred which are consistent with the seasonal deposition pattern. Tar from Coal Oil Point natural oil seeps is transported southward in the southern California gyre during the spring, summer and fall seasons, but probably undergoes northward transport during the winter season due to the surfacing of the Davidson Current. Tar from the Santa Monica Bay natural oil seeps moves onshore, but deposition rate seems to depend on seepage flow rate.

  17. Heating tar sands formations while controlling pressure

    DOEpatents

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  18. Heating tar sands formations to visbreaking temperatures

    DOEpatents

    Karanikas, John Michael; Colmenares, Tulio Rafael; Zhang, Etuan; Marino, Marian; Roes, Augustinus Wilhelmus Maria; Ryan, Robert Charles; Beer, Gary Lee; Dombrowski, Robert James; Jaiswal, Namit

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  19. Fractionation of aqueous cigarette tar extracts: fractions that contain the tar radical cause DNA damage.

    PubMed

    Pryor, W A; Stone, K; Zang, L Y; Bermúdez, E

    1998-05-01

    Previously, we have shown that aqueous cigarette tar (ACT) extracts contain a long-lived tar radical that associates with DNA in isolated rat alveolar macrophages and causes DNA damage in isolated rat thymocytes. These ACT solutions reduce oxygen to produce superoxide and, ultimately, hydrogen peroxide. In this study, we report the fractionation of ACT solutions prepared from the tar from five cigarettes using Sephadex columns. The fractions were analyzed by UV and electron paramagnetic resonance (EPR) spectroscopy and gas chromatography/mass spectrometry (GC/MS). The fractions containing polyphenolic species (principally catechol and hydroquinone, as determined by MS) caused most of the observed DNA damage in rat thymocytes. These DNA-damaging fractions produced superoxide, H2O2, and hydroxyl radicals. Stable free radicals were identified as o- and p-benzosemiquinone radicals by EPR spectroscopy. Hydroxyl radicals were detected by EPR spin-trapping with 5, 5-dimethyl-1-pyrroline N-oxide (DMPO). Catalase inhibited the EPR signal of the DMPO-OH adduct, indicating that H2O2 is the precursor of the hydroxyl radical spin adduct. The Sephadex separation resulted in a 90-fold concentration of the hydrogen peroxide-generating capacity of the fractions that contained polyphenols, relative to the unfractionated ACT solution. Another fraction, which contained nicotine, caused some DNA damage, but this damage was 28-fold less than the damage caused by the most damaging phenolic fraction. These results support our hypothesis that the tar radical system is an equilibrium mixture of semiquinones, hydroquinones, and quinones. The tar radical associates with DNA, causes DNA damage, and very likely is involved in the toxicity associated with cigarette smoking.

  20. [Birch pollen allergy].

    PubMed

    Lavaud, F; Fore, M; Fontaine, J-F; Pérotin, J M; de Blay, F

    2014-02-01

    In the North-East of France, birch is the main tree responsible of spring pollen allergy. However, the epidemiology of sensitization to birch pollen remains unclear. Monosensitization to birch pollen seems rare because of the frequency of cross-reactions with other pollens of the same botanical family via the major allergen Bet v 1. Around one third of patients with allergic rhinoconjunctivitis due to birch pollen are also asthmatics and a half suffer from a food allergy, essentially an oral syndrome due to rosaceae fruits eaten raw. The molecular allergens of birch pollen are well-known and have been cloned. They are available for use in in vitro diagnostic tests and also in clinical trials of specific immunotherapy.

  1. Immunotherapy in food allergy.

    PubMed

    Kamdar, Toral; Bryce, Paul J

    2010-05-01

    Food allergies are caused by immune responses to food proteins and represent a breakdown of oral tolerance. They can range from mild pruritus to life-threatening anaphylaxis. The only current consensus for treatment is food avoidance, which is fraught with compliance issues. For this reason, there has been recent interest in immunotherapy, which may induce desensitization and possibly even tolerance. Through these effects, immunotherapy may decrease the potential for adverse serious reactions with accidental ingestions while potentially leading to an overall health benefit. In this review, we discuss the mechanisms of food allergy and give an overview of the various immunotherapeutic options and current supporting evidence, as well as look towards the future of potential novel therapeutic modalities.

  2. Immunotherapy in food allergy

    PubMed Central

    Kamdar, Toral; Bryce, Paul J

    2010-01-01

    Food allergies are caused by immune responses to food proteins and represent a breakdown of oral tolerance. They can range from mild pruritis to life-threatening anaphylaxis. The only current consensus for treatment is food avoidance, which is fraught with compliance issues. For this reason, there has been recent interest in immunotherapy, which may induce desensitization and possibly even tolerance. Through these effects, immunotherapy may decrease the potential for adverse serious reactions with accidental ingestions while potentially leading to an overall health benefit. In this review, we discuss the mechanisms of food allergy and give an overview of the various immunotherapeutic options and current supporting evidence, as well as look towards the future of potential novel therapeutic modalities. PMID:20543886

  3. Mechanisms of food allergy.

    PubMed

    Helm, R M; Burks, A W

    2000-12-01

    The prevalence of food allergy continues to rise, particularly in 'westernized' societies; it has been linked to the 'hygiene hypothesis' and the increased diversity of food consumption worldwide. The pathogenic mechanisms and Th1/Th2 paradigm are being closely examined with respect to the occurrence of inflammatory and injury/repair responses at different mucosal sites. Genetically modified plants as potential food sources and allergenicity are current topics of controversy.

  4. Probiotics and food allergy.

    PubMed

    Castellazzi, Anna Maria; Valsecchi, Chiara; Caimmi, Silvia; Licari, Amelia; Marseglia, Alessia; Leoni, Maria Chiara; Caimmi, Davide; Miraglia del Giudice, Michele; Leonardi, Salvatore; La Rosa, Mario; Marseglia, Gian Luigi

    2013-07-29

    The exact prevalence of food allergy in the general population is unknown, but almost 12% of pediatric population refers a suspicion of food allergy. IgE mediated reactions to food are actually the best-characterized types of allergy, and they might be particularly harmful especially in children. According to the "hygiene hypothesis" low or no exposure to exogenous antigens in early life may increase the risk of allergic diseases by both delaying the development of the immune tolerance and limiting the Th2/Th1 switch. The critical role of intestinal microbiota in the development of immune tolerance improved recently the interest on probiotics, prebiotics, antioxidants, polyunsaturated fatty acid, folate and vitamins, which seem to have positive effects on the immune functions.Probiotics consist in bacteria or yeast, able to re-colonize and restore microflora symbiosis in intestinal tract. One of the most important characteristics of probiotics is their safety for human health. Thanks to their ability to adhere to intestinal epithelial cells and to modulate and stabilize the composition of gut microflora, probiotics bacteria may play an important role in the regulation of intestinal and systemic immunity. They actually seem capable of restoring the intestinal microbic equilibrium and modulating the activation of immune cells.Several studies have been recently conducted on the role of probiotics in preventing and/or treating allergic disorders, but the results are often quite contradictory, probably because of the heterogeneity of strains, the duration of therapy and the doses administered to patients. Therefore, new studies are needed in order to clarify the functions and the utility of probiotics in food allergies and ion other types of allergic disorders.

  5. Gastrointestinal food allergies.

    PubMed

    Heine, Ralf G

    2015-01-01

    Gastrointestinal food allergies present during early childhood with a diverse range of symptoms. Cow's milk, soy and wheat are the three most common gastrointestinal food allergens. Several clinical syndromes have been described, including food protein-induced enteropathy, proctocolitis and enterocolitis. In contrast with immediate, IgE-mediated food allergies, the onset of gastrointestinal symptoms is delayed for at least 1-2 hours after ingestion in non-IgE-mediated allergic disorders. The pathophysiology of these non-IgE-mediated allergic disorders is poorly understood, and useful in vitro markers are lacking. The results of the skin prick test or measurement of the food-specific serum IgE level is generally negative, although low-positive results may occur. Diagnosis therefore relies on the recognition of a particular clinical phenotype as well as the demonstration of clear clinical improvement after food allergen elimination and the re-emergence of symptoms upon challenge. There is a significant clinical overlap between non-IgE-mediated food allergy and several common paediatric gastroenterological conditions, which may lead to diagnostic confusion. The treatment of gastrointestinal food allergies requires the strict elimination of offending food allergens until tolerance has developed. In breast-fed infants, a maternal elimination diet is often sufficient to control symptoms. In formula-fed infants, treatment usually involves the use an extensively hydrolysed or amino acid-based formula. Apart from the use of hypoallergenic formulae, the solid diets of these children also need to be kept free of specific food allergens, as clinically indicated. The nutritional progress of infants and young children should be carefully monitored, and they should undergo ongoing, regular food protein elimination reassessments by cautious food challenges to monitor for possible tolerance development.

  6. [Stress and allergy].

    PubMed

    Radosević-Vidacek, Biserka; Macan, Jelena; Kosćec, Adrijana

    2004-06-01

    Stress is one of the components in the complex interaction of environmental, genetic, physiological, psychological, behavioural and social factors that can influence the body's ability to remain healthy or become healthy, to resist or overcome a disease. Stress can alter neuroendocrine and immune mechanisms of health and disease through various psychosocial processes. In addition, it can affect health through the impact on health-impairing behaviours and on compliance with medical regimens. At the same time, the relationship between stress and health is not unidirectional but bi-directional. Current views on the relation between stress and allergy vary from the denial of any relationship that could fundamentally help in allergy treatment to the widespread opinion that psychological stress can exacerbate some skin symptoms and precipitate asthma. The role of stress in the genesis, incidence and symptomatology of allergy still remains a controversial issue since the mechanisms of that relationship are not well understood. Starting from the biopsychosocial model of disease, we introduced the Social Readjustment Rating Scale which measures stressful life events, and the WHOQOL-BREF which measures subjective quality of life, into an extensive multidisciplinary study of immunotoxic effects of indoor bioaerosols and lifestyle. This paper describes the characteristics of those two questionnaires and discusses the relationship between stress and various domains of the quality of life. The Social Readjustment Rating Scale proved to be a reliable predictor for quality of life in the domains of physical health and environment. Future analyses will examine the role of stress and subjective quality of life in allergy.

  7. Overview of penicillin allergy.

    PubMed

    Chang, Christopher; Mahmood, Mubashar M; Teuber, Suzanne S; Gershwin, M Eric

    2012-08-01

    Allergy to penicillin is the most commonly reported antibiotic allergy. However, most patients who report a positive history of a prior reaction to penicillin are not found to be allergic to penicillin upon skin testing. Often, this history is vague or based on a parent's recollection of an event that occurred in the distant past. Avoidance of penicillin based on self-reported allergic history alone often leads to the use of an alternate antibiotic with greater cost or side effect profile. Patients with a negative skin test to both major and minor determinants may generally be given penicillin, with a statistical risk of developing an allergic reaction similar to that observed in the general population. A more cautious approach in these cases where the degree of suspicion is low, an allergic etiology is unproven, or there is a negative skin test, is to do a graded challenge. If the skin test is positive, an alternate antibiotic should be used. If, however, an alternate antibiotic is not available, then desensitization may be performed, but there are limitations to desensitization as well, and tolerance is not permanent. Avoidance of cephalosporins may be recommended in cases of penicillin allergy, but newer generation cephalosporins have demonstrate less cross-reactivity to penicillin than earlier generation ones. Desensitization protocols for cephalosporins are available but not standardized. The mechanisms of antibiotic sensitization are not clearly understood.

  8. Occupational allergies and asthma.

    PubMed Central

    Tarlo, S. M.

    1999-01-01

    OBJECTIVE: To review aspects of occupational allergies and asthma for primary care physicians recognizing, diagnosing, and managing patients with these conditions. QUALITY OF EVIDENCE: Studies in the medical literature mainly provide level 2 evidence, that is, from at least one well-designed clinical trial without randomization, from cohort or case-control analytical studies, from multiple time series, or from dramatic results in uncontrolled experiments. MAIN MESSAGE: Occupational allergies and asthma have the best prognosis with an early, accurate diagnosis and subsequent avoidance of exposure to the relevant sensitizer. These diagnoses can normally be suspected from the clinical history. Primary care physicians can also initiate investigations to make an objective diagnosis, can assess workplace exposure agents from the history, and can review appropriate data sheets on material safety. Specialist evaluation is likely to be needed for skin tests, however, and for other specialized tests (such as pulmonary function assessments at work and off work or specific challenges with the suspected workplace agent). Patients with a confirmed diagnosis need appropriate medical management of their allergic manifestations or asthma, but also often require psychosocial support during the period of investigation and management, especially in relation to required changes in their work and to compensation or insurance claims. CONCLUSIONS: Consider workplace exposure as a source of patients' allergies or asthma and aim to make an early, accurate diagnosis. PMID:10386216

  9. Allergy and cancer.

    PubMed

    Lindelöf, B; Granath, F; Tengvall-Linder, M; Ekbom, A

    2005-09-01

    Conflicting results have provided support for two distinct and contradictory hypotheses: (i) allergy has a protective effect against cancer by enhanced immune surveillance, and (ii) allergy is associated with an increased risk of cancer by chronic immune stimulation. We therefore aimed us to perform a large epidemiological study with a defined allergic disease cohort. During the years 1988-2000, 70 136 patients tested for total serum immunoglobulin E (IgE) and 57 815 tested with Phadiatop for diagnosing allergic disease at Karolinska University Hospital, Stockholm, Sweden, were linked with the Swedish Cancer Registry for a virtually complete follow up with regard to cancer. The total number of observed cancers was normal in the total serum IgE-cohort; standardized incidence ratio (SIR) = 0.98 (95% CI: 0.92-1.04) and in the Phadiatop-cohort: SIR = 0.99 (0.92-1.06) independent of the level of IgE and positive or negative Phadiatop. Specific analysis was done for cancer of the lung, cervix, pancreas, lymphoma, and nonmelanoma skin cancer. None of these forms of cancer had increased risks. The study does not support the hypothesis that allergy has a protective effect against cancer, nor does it support an increased risk.

  10. Latex allergy in children.

    PubMed

    Niggemann, B; Breiteneder, H

    2000-02-01

    Natural rubber is a component of the latex of the tropical Hevea brasiliensis tree which is widely used in the manufacturing of medical devices and a large variety of articles for everyday use. Over a dozen allergens have been identified in the latex of H. brasiliensis. The allergens Hev b 1, Hev b 3, Hev b 6, and Hev b 7 are proteins that are involved in the biosynthesis of rubber or the coagulation of latex. Allergens that are part of the plant's defense system are represented by Hev b 2 and class I endochitinases. The allergens Hev b 4, Hev b 5, and Hev b 8-10 were classified as either structural or housekeeping proteins. Immediate-type hypersensitivity reactions to proteins present in Hevea latex were first described in 1927. Since then, natural rubber latex (NRL) allergy has become an important medical problem for an increasing number of individuals. Sensitization mainly occurs by wound or mucosal contact with NRL devices during surgery or by inhalation of airborne allergens released from powdered latex gloves. The number of surgical interventions and an atopic disposition are the most important risk factors for developing latex allergy, especially in children with spina bifida. Exposure to NRL products should be carefully avoided for individuals who belong to high-risk groups. Initial studies on establishing a latex-free environment for surgery in all spina bifida patients have reported on a decrease in sensitization and allergy to NRL.

  11. Immunotherapy for mold allergy.

    PubMed

    Coop, Christopher A

    2014-12-01

    The objective of this article is to review the available studies regarding mold immunotherapy. A literature search was conducted in MEDLINE to identify peer-reviewed articles related to mold immunotherapy using the following keywords: mold, allergy, asthma, and immunotherapy. In addition, references cited within these articles were also reviewed. Articles were selected based on their relevance to the topic. Allergic responses to inhaled mold antigens are a recognized factor in allergic rhinitis and asthma. There are significant problems with respect to the production of relevant allergen material for the diagnosis and treatment of mold allergy with immunotherapy. Mold allergens contain proteases and should not be mixed with other allergens for immunotherapy. Most of the immunotherapy studies focus on two molds, Alternaria and Cladosporium. There is a lack of randomized placebo-controlled trials when evaluating the efficacy of mold immunotherapy with trials only focusing on immunotherapy to Alternaria and Cladosporium. Additional studies are needed regarding mold allergy and immunotherapy focusing on which molds are important for causing allergic disease.

  12. Globalisation and allergy.

    PubMed

    Castelain, Michel

    2011-01-01

    Globalisation brings patients more and more into contact with products or food from other cultures or countries. Europeans may be confronted with allergens not yet known in Europe - such as dimethylfumarate - responsible for contact allergy epidemics. Moreover, "low cost" goods, not always legally imported into Europe, sometimes may lead to European legislation being circumvented and thus bring our patients into contact with components that have been banned from manufacturing processes or strongly regulated, such as nickel in jewelry or telephones, some colouring agents in clothes or preservatives in cosmetics. Disinfection measures for freight containers arriving from other continents into our harbours lead to fumigants and other toxic products contaminating the air and the transported products or goods. Globalisation can not only elicit contact allergy but also airborne contact dermatitis or food allergy. The aim of this paper is not to make an exhaustive review of cutaneous allergic problems elicited by globalisation, but to illustrate this new worldwide problem with a few meaningful examples.

  13. [Allergy to macadamia nut].

    PubMed

    Inaba, Yasuko; Yagami, Akiko; Suzuki, Kayoko; Matsunaga, Kayoko

    2007-07-01

    The patient was a 23-year-old female with a history of atopic dermatitis, allergic rhinitis, and allergic conjunctivitis. In her fourth year of primary school, she ate macadamia nuts and developed oral discomfort and generalized uticaria. In her second year of junior high school, she ate macadamia nuts and developed oral and pharyngeal discomfort, followed by generalized uticaria and dyspnea. At the age of 20 years, she also developed oral discomfort after eating vegetables in a Chinese dish containing macadamia nuts and visited our department for close examination. A scratch test of extract oil (concentration, as is) was positive, and a diagnosis of immediate allergy due to macadamia nuts was made. Thereafter, she avoided macadamia nuts completely and had no further recurrence. This patient developed oral allergy syndrome (OAS) after eating macadamia nuts. However, she was negative for Bet v1 and Bet v2 as allergens in white birch pollinosis, in which OAS has been most frequently reported. She had Japanese cedar pollinosis, but its onset was when she was in her second year of high school. Therefore, it is unlikely that Japanese cedar pollen is a sensitization antigen for macadamia nut allergy.

  14. The extraction of bitumen from western tar sands. Annual report

    SciTech Connect

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  15. The extraction of bitumen from western tar sands

    SciTech Connect

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  16. 48 CFR Appendix to Part 1252 - Tar Matrix

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Tar Matrix Appendix to Part 1252 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Pt. 1252, App. Appendix to Part 1252—Tar Matrix...

  17. 33 CFR 117.831 - Pamlico and Tar Rivers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pamlico and Tar Rivers. 117.831... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.831 Pamlico and Tar Rivers. The... Grimesland, shall open on signal if at least 24 hours notice is given. The bridge owners shall...

  18. 33 CFR 117.831 - Pamlico and Tar Rivers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pamlico and Tar Rivers. 117.831... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.831 Pamlico and Tar Rivers. The... Grimesland, shall open on signal if at least 24 hours notice is given. The bridge owners shall...

  19. 33 CFR 117.831 - Pamlico and Tar Rivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pamlico and Tar Rivers. 117.831... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.831 Pamlico and Tar Rivers. The... Grimesland, shall open on signal if at least 24 hours notice is given. The bridge owners shall...

  20. 33 CFR 117.831 - Pamlico and Tar Rivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pamlico and Tar Rivers. 117.831... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.831 Pamlico and Tar Rivers. The... Grimesland, shall open on signal if at least 24 hours notice is given. The bridge owners shall...