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Sample records for environment chlorinated hydrocarbons

  1. Biogenic nanopalladium based remediation of chlorinated hydrocarbons in marine environments.

    Science.gov (United States)

    Hosseinkhani, Baharak; Hennebel, Tom; Van Nevel, Sam; Verschuere, Stephanie; Yakimov, Michail M; Cappello, Simone; Blaghen, Mohamed; Boon, Nico

    2014-01-01

    Biogenic catalysts have been studied over the last 10 years in freshwater and soil environments, but neither their formation nor their application has been explored in marine ecosystems. The objective of this study was to develop a biogenic nanopalladium-based remediation method for reducing chlorinated hydrocarbons from marine environments by employing indigenous marine bacteria. Thirty facultative aerobic marine strains were isolated from two contaminated sites, the Lagoon of Mar Chica, Morocco, and Priolo Gargallo Syracuse, Italy. Eight strains showed concurrent palladium precipitation and biohydrogen production. X-ray diffraction and thin section transmission electron microscopy analysis indicated the presence of metallic Pd nanoparticles of various sizes (5-20 nm) formed either in the cytoplasm, in the periplasmic space, or extracellularly. These biogenic catalysts were used to dechlorinate trichloroethylene in simulated marine environments. Complete dehalogenation of 20 mg L(-1) trichloroethylene was achieved within 1 h using 50 mg L(-1) biogenic nanopalladium. These biogenic nanoparticles are promising developments for future marine bioremediation applications.

  2. Process for Photochemical Chlorination of Hydrocarbons

    Science.gov (United States)

    Beanblossom, W S

    1951-08-28

    A process for chlorination of a major portion of the hydrogen atoms of paraffinic hydrocarbons of five or more carbon atoms may be replaced by subjecting the hydrocarbon to the action of chlorine under active light. The initial chlorination is begun at 25 to 30 deg C with the chlorine diluted with HCl. The later stages may be carried out with undiluted chlorine and the temperature gradually raised to about 129 deg C.

  3. Hydrochloric acid recycling from chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sowieja, D. [Sulzer Escher Wyss GmbH, Ravensburg (Germany); Schaub, M. [Sulzer Chemtech Ltd., Winterthur (Switzerland)

    1993-12-31

    Chlorinated hydrocarbons present a major ecological hazard since most of them are only poorly biodegradable. Incineration is an economical process for their destruction, however the usually recovered sodium or calcium chlorides do not present a value and their disposal may even be very costly. Recovery of hydrochloric acid may therefore present an economical solution, mainly were large quantities of highly chlorinated compounds can be processed (author) 6 refs., 4 figs., 1 tab.

  4. Microbiological aspects of the removal of chlorinated hydrocarbons from air

    NARCIS (Netherlands)

    Dolfing, Jan; Wijngaard, Arjan J. van den; Janssen, Dick B.

    1993-01-01

    Chlorinated hydrocarbons are widely used synthetic chemicals that are frequently present in industrial emissions. Bacterial degradation has been demonstrated for several components of this class of compounds. Structural features that affect the degradability include the number of chlorine atoms and

  5. Riverine input of chlorinated hydrocarbons in the coastal pollution

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Everaarts, J.M.

    of various chlorinated hydrocarbons. It deals with an in-depth analysis of pollution of the coastal ecosystem around the Netherlands, U.K. and Germany due to inputs of contaminants from the rivers namely, Elbe, Weser, Ems Ijssel, Rhine, Meuse, Scheldt, Thames...

  6. Chlorinated hydrocarbons: oxidation in the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Wood, J.M.

    1982-05-01

    The review explores the limitations imposed on the biological oxidation of some synthetic compounds, as determined from recent studies with enzymes which catalyze the oxidation of aromatic compounds. Examples are furnished of ways in which existing metabolic pathways can adapt to degrade, or partially degrade, a number of widely used synthetic chemicals. Special emphasis is given to the problems confronting microorganisms in the oxidative degradation of the most persistant chlorinated aromatic compounds such as PCBs. In addition, the potential application of genetic engineering to the selection of mutants for the purpose of degrading specific pollutants in industrial effluents is discussed. (JMT)

  7. Supported metal nanoparticles for the remediation of chlorinated hydrocarbons

    Science.gov (United States)

    Schrick, Bettina

    Zero valent iron filings are currently being used in pilot scale field studies to dehalogenate toxic chlorinated hydrocarbons from contaminated surface- and groundwater. Iron filings reduce trichloroethylene (TCE), a model contaminant, via two interconnected degradation pathways: (a) reductive beta-elimination and (b) sequential hydrogenolysis, in which each chlorine atom is sequentially replaced by hydrogen. For the latter pathway, problems arise because the dehalogenation rate decreases as the number of chlorine atoms in the molecule decreases. Therefore, some of the products formed, such as vinyl chloride (VC), are more toxic than the parent compound (TCE), and are only slowly reduced by iron. To improve the rate, cost and technique of remediation for chlorinated hydrocarbons, zero valent nickel-iron (Ni-Fe) nanoparticles have been developed. To elucidate the dehalogenation reaction and particularly the product distributions from a mechanistic standpoint, the roles that nickel and iron play in the dehalogenation of TCE were studied. On the bimetallic particles, the reaction occurs by nickel-catalyzed hydrodechlorination. As the iron actively corrodes, the cathodically protected nickel surface chemisorbs hydrogen ions, and TCE adsorbed to the Ni surface is thus hydrogenated. This reaction competes kinetically with the evolution of molecular hydrogen. Hydrogenolysis of the C-Cl bond results in the formation of linear, as well as branched saturated and unsaturated hydrocarbons. Dispersing the nanometals onto high surface area supports, such as hydrophilic carbon or polyacrylic acid (PAA), provides a delivery vehicle for the reactive nanoparticles. The support acts as a nanometal carrier, and may also help preconcentrate the toxins, and provide a conductive pathway for electron transfer. In general, supports are expected to stabilize the nanoparticles and give an increased surface to volume ratio. The carbon- and PAA-supported nanometals form a permanent suspension

  8. Iron-carbon composites for the remediation of chlorinated hydrocarbons

    Science.gov (United States)

    Sunkara, Bhanu Kiran

    This research is focused on engineering submicron spherical carbon particles as effective carriers/supports for nanoscale zerovalent iron (NZVI) particles to address the in situ remediation of soil and groundwater chlorinated contaminants. Chlorinated hydrocarbons such as trichloroethylene (TCE) and tetrachloroethylene (PCE) form a class of dense non-aqueous phase liquid (DNAPL) toxic contaminants in soil and groundwater. The in situ injection of NZVI particles to reduce DNAPLs is a potentially simple, cost-effective, and environmentally benign technology that has become a preferred method in the remediation of these compounds. However, unsupported NZVI particles exhibit ferromagnetism leading to particle aggregation and loss in mobility through the subsurface. This work demonstrates two approaches to prepare carbon supported NZVI (iron-carbon composites) particles. The objective is to establish these iron-carbon composites as extremely useful materials for the environmental remediation of chlorinated hydrocarbons and suitable materials for the in situ injection technology. This research also demonstrates that it is possible to vary the placement of iron nanoparticles either on the external surface or within the interior of carbon microspheres using a one-step aerosol-based process. The simple process of modifying iron placement has significant potential applications in heterogeneous catalysis as both the iron and carbon are widely used catalysts and catalyst supports. Furthermore, the aerosol-based process is applied to prepare new class of supported catalytic materials such as carbon-supported palladium nanoparticles for ex situ remediation of contaminated water. The iron-carbon composites developed in this research have multiple functionalities (a) they are reactive and function effectively in reductive dehalogenation (b) they are highly adsorptive thereby bringing the chlorinated compound to the proximity of the reactive sites and also serving as adsorption

  9. Determinants of the microbial community structure of eutrophic, hyporheic river sediments polluted with chlorinated aliphatic hydrocarbons

    NARCIS (Netherlands)

    Hamonts, K.; Ryngaert, A.; Smidt, H.; Springael, D.; Dejonghe, W.

    2014-01-01

    Chlorinated aliphatic hydrocarbons (CAHs) often discharge into rivers as contaminated groundwater baseflow. As biotransformation of CAHs in the impacted river sediments might be an effective remediation strategy, we investigated the determinants of the microbial community structure of eutrophic,

  10. Reactions of chlorine atoms with a series of aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Lin; Arey, Janet; Atkinson, Roger

    2005-07-15

    Aromatic hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), are present in urban and rural atmospheres. Reactions of PAHs with Cl atoms may occur in the marine boundary layer and in coastal regions. To assess the importance of these reactions and to investigate whether any unique chlorine-containing products are formed from these reactions, we have measured the rate constants for the gas-phase reactions of Cl atoms with toluene-d8, 1,3,5-trimethylbenzene (1,3,5-TMB), naphthalene, 1-methylnaphthalene-d10 (1-MN-d10), 1- and 2-methylnaphthalene (1- and 2-MN), 1- and 2-ethylnaphthalene (1- and 2-EN), and the dimethylnaphthalenes (DMNs) at 296 +/- 2 K. A relative rate technique was used, and, using our measured rate constant forthe reaction of Cl atoms with 1,3,5-TMB of 2.42 x 10(-10) cm3 molecule(-1) s(-1), the rate constants (in units of 10(-10) cm3 molecule(-1) s(-1)) are as follows: naphthalene, isotope effects for the toluene-d8 and 1-MN-d10 reactions indicate that the reactions proceed by initial H- (or D-) atom abstraction. The products identified and quantified from the toluene and 1-MN reactions using gas chromatography and in situ direct air sampling atmospheric pressure ionization tandem mass spectrometry were benzaldehyde (84% +/- 7% yield) and benzyl alcohol (11% +/- 2% yield) from toluene and 1-naphthaldehyde (approximately 36%, lower limit to yield) and 1-naphthyl alcohol (approximately 12%, lower limit to yield) from 1-MN. These products confirm that H-atom abstraction is the dominant, if not sole, reaction pathway for the alkylbenzenes and alkylnaphthalenes, consistent with the 100-fold lower rate constant measured for naphthalene compared to the alkylnaphthalenes and with the measured deuterium isotope effects.

  11. Assimilation of chlorinated alkanes by hydrocarbon-utilizing fungi

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, G.L.; Perry, J.J.

    1984-12-01

    The fatty acid compositions of two filamentous fungi (Cunninghamella elegans and Penicillium zonatum) and a yeast (Candida lipolytica) were determined after the organisms were grown on 1-chlorohexadecane or 1-chlorooctadecane. These organisms utilized the chlorinated alkanes as sole sources of carbon and energy. Analyses of the fatty acids present after growth on the chlorinated alkanes indicated that 60 to 70% of the total fatty acids in C. elegans were chlorinated. Approximately 50% of the fatty acids in C. lipolytica were also chlorinated. P. zonatum contained 20% 1-chlorohexadecanoic acid after growth on either substrate but did not incorporate C/sub 18/ chlorinated fatty acids.

  12. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  13. Heavy metal and chlorinated hydrocarbon residues in California sea loins (Zalophus californianus californianus)

    Energy Technology Data Exchange (ETDEWEB)

    Buhler, D.R.; Claeys, R.R.; Mate, B.R.

    1975-12-01

    Samples of various tissues and organs from healthy California sea lions (Zalophus californianus californianus) and sick animals (apparently with leptospirosis) collected along the central Oregon coast in 1970, 1971, and 1973 were analyzed for total mercury, methylmercury, cadmium, and chlorinated hydrocarbons. Maximum mercury concentrations of 74 to 170 ppM occurred in sea lion liver, but only 1.6 to 3.7 percent of this was present as methylmercury. Cadmium was concentrated primarily in the kidney which contained 7.2 to 12.0 ppM of the metal. Chlorinated hydrocarbon residues in sea lion fat ranged between 253 to 475 ppM DDE, and 21.2 and 34.1 ppM PCB. Although mercury, cadmium, and chlorinated hydrocarbon residues in some of the sick sea lions were significantly higher than those present in healthy animals, it is not possible to relate these differences to the onset of leptospirosis.

  14. Reactions of polynuclear aromatic hydrocarbons with chlorine and chlorine dioxide in coal tar lined pipes

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, T.; Maier, M.; Sacher, F.; Maier, D. [University of Karlsruhe, Karlsruhe (Germany). Engler Bunte Institut

    1997-12-31

    In the presence of disinfectants, PAH are remobilised from the coal tar lining of water distribution mains. Reactions of the PAH with chlorine and chlorine dioxide can lead to chlorinated PAH that might show higher mutagenic effects that the parent PAH. Detection limits in the lower nanogram-per-litre level for the determination of PAH and chlorinated PAH were achieved by using solid phase micro extraction and a gas chromatographic mass spectrometric device. Thus, the reactions of four PAH (anthracene, fluoranthene, fluorene and phenanthrene) with chlorine and chlorine dioxide under conditions and at concentrations of common practice in the drinking water distribution system could be investigated. In batch experiments with demineralised and drinking water at pH 7, the concentrations of fluoranthene, fluorene and phenanthrene remained constant, whereas anthracene reacted quantitatively with both disinfectants. The reaction of anthracene followed by pseudo-first order kinetics. In these reactions no chlorinated products could be detected, only monohydroxyanthracene and anthraquinone were identified. The toxic effect of a set of chlorinated and oxidised PAH was also examined.

  15. Kinetics of Chlorinated Hydrocarbon Degradation by Methylosinus trichosporium OB3b and Toxicity of Trichloroethylene

    NARCIS (Netherlands)

    Oldenhuis, Roelof; Oedzes, Johannes Y.; Waarde, Jacob J. van der; Janssen, Dick B.

    The kinetics of the degradation of trichloroethylene (TCE) and seven other chlorinated aliphatic hydrocarbons by Methylosinus trichosporium OB3b were studied. All experiments were performed with cells grown under copper stress and thus expressing soluble methane monooxygenase. Compounds that were

  16. Application of Pseudomonas sp. strain DCA1 for the removal of chlorinated hydrocarbons

    NARCIS (Netherlands)

    Hage, J.C.

    2004-01-01

    The large-scale application of chlorinated aliphatic hydrocarbons (CAHs) has resulted in many cases of groundwater contamination. Contaminated groundwater can be remediated by pump-and-treat: the groundwater is pumped to the surface and treated. The groundwater can be treated in bioreactors, in

  17. Photodegradation of chlorinated hydrocarbons in the presence and absence of dissolved oxygen in water.

    Science.gov (United States)

    Shirayama, H; Tohezo, Y; Taguchi, S

    2001-06-01

    The photodegradation rates of seven chlorinated hydrocarbons; C2Cl4, C2HCl3, C2H4Cl2, 1,1,1-C2H3Cl3, 1,1,2-C2H3Cl3, CHCl3, CCl4 were investigated under the UV bandwidths of 185 and 254 nm in the presence and absence of dissolved oxygen (DO) in water. These hydrocarbons are possible contaminants of groundwater. This study confirms that the degradation rates of all chlorinated hydrocarbons are elevated in the absence of DO. This was especially apparent for chlorinated methane and ethane. Tetrachloroethylene's rate was the highest among the seven hydrocarbons regardless of the DO levels. It was clear that the concentration of intermediate trichloroethylene produced by photodegradation of tetrachloroethylene in the absence of DO was 1/50th of that in the presence of DO. Photodegradation in the presence of DO resulted in the formation of O3 and hydroxyl radicals. Alternatively, the photodegradation in the absence of DO resulted in the formation of organic radicals and a dissociation of the bond. It is discussed that DO acts as an "inner filter" or "scavenger" that reduces the UV light intensity in the photoreactor. Molecular O2 has absorption bands at 185 and 254 nm, the former being stronger. The processes of degradation depend on the degradation rate relative to the presence and absence of DO.

  18. Persistent pollutants: a brief history of the discovery of the widespread toxicity of chlorinated hydrocarbons.

    Science.gov (United States)

    Rosner, David; Markowitz, Gerald

    2013-01-01

    Rachel Carson's Silent Spring is often depicted as the beginning of a broad societal concern about the dangers of DDT and other pesticides. Attention to the other chlorinated hydrocarbons, specifically PCBs, is seen as an outgrowth of the late 1960s environmental movement. Carson's work was clearly critical in broadening the history to include the environmental impact and set the stage for the path breaking work decades later by Theo Colburn and others on endocrine disruptions associated with other synthetic chemicals. This article reviews the development of the understanding the dangers of the chlorinated hydrocarbons in the decades preceding Carson's book. Although little noticed, Rachel Carson makes this observation herself. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Determination of chlorinated hydrocarbons in water using highly sensitive mid-infrared sensor technology.

    Science.gov (United States)

    Lu, Rui; Mizaikoff, Boris; Li, Wen-Wei; Qian, Chen; Katzir, Abraham; Raichlin, Yosef; Sheng, Guo-Ping; Yu, Han-Qing

    2013-01-01

    Chlorinated aliphatic hydrocarbons and chlorinated aromatic hydrocarbons (CHCs) are toxic and carcinogenic contaminants commonly found in environmental samples, and efficient online detection of these contaminants is still challenging at the present stage. Here, we report an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor for in-situ and simultaneous detection of multiple CHCs, including monochlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, trichloroethylene, perchloroethylene, and chloroform. The polycrystalline silver halide sensor fiber had a unique integrated planar-cylindric geometry, and was coated with an ethylene/propylene copolymer membrane to act as a solid phase extractor, which greatly amplified the analytical signal and contributed to a higher detection sensitivity compared to the previously reported sensors. This system exhibited a high detection sensitivity towards the CHCs mixture at a wide concentration range of 5~700 ppb. The FTIR-ATR sensor described in this study has a high potential to be utilized as a trace-sensitive on-line device for water contamination monitoring.

  20. Evidence for Perchlorates and the Origin of Chlorinated Hydrocarbons Detected by SAM at the Rocknest Aeolian Deposit in Gale Crater

    Science.gov (United States)

    Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.; hide

    2013-01-01

    A single scoop of the Rocknest aeolian deposit was sieved (less than 150 micrometers), and four separate sample portions, each with a mass of approximately 50 mg, were delivered to individual cups inside the Sample Analysis at Mars (SAM) instrument by the Mars Science Laboratory rover's sample acquisition system. The samples were analyzed separately by the SAM pyrolysis evolved gas and gas chromatograph mass spectrometer analysis modes. Several chlorinated hydrocarbons including chloromethane, dichloromethane, trichloromethane, a chloromethylpropene, and chlorobenzene were identified by SAM above background levels with abundances of approximately 0.01 to 2.3 nmol. The evolution of the chloromethanes observed during pyrolysis is coincident with the increase in O2 released from the Rocknest sample and the decomposition of a product of N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), a chemical whose vapors were released from a derivatization cup inside SAM. The best candidate for the oxychlorine compounds in Rocknest is a hydrated calcium perchlorate (Ca(ClO4)2·nH2O), based on the temperature release of O2 that correlates with the release of the chlorinated hydrocarbons measured by SAM, although other chlorine-bearing phases are being considered. Laboratory analog experiments suggest that the reaction of Martian chlorine from perchlorate decomposition with terrestrial organic carbon from MTBSTFA during pyrolysis can explain the presence of three chloromethanes and a chloromethylpropene detected by SAM. Chlorobenzene may be attributed to reactions of Martian chlorine released during pyrolysis with terrestrial benzene or toluene derived from 2,6-diphenylphenylene oxide (Tenax) on the SAM hydrocarbon trap. At this time we do not have definitive evidence to support a nonterrestrial carbon source for these chlorinated hydrocarbons, nor do we exclude the possibility that future SAM analyses will reveal the presence of organic compounds native to the

  1. Chlorinated Hydrocarbon Degradation in Plants: Mechanisms and Enhancement of Phytoremediation of Groundwater Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Strand, Stuart E.

    2002-06-01

    Several varieties of transgenic poplar containing cytochrome P-450 2E1 have been constructed and are undergoing tests. Strategies for improving public acceptance and safety of transgenic poplar for chlorinated hydrocarbon phytoremediation are being developed. We have discovered a unique rhizobium species that lives within the stems of poplar and we are investigating whether this bacterium contributes nitrogen fixed from the air to the plant and whether this endophyte could be used to introduce genes into poplar. Studies of the production of chloride ion from TCE have shown that our present P-450 constructs did not produce chloride more rapidly than wild type plants. Follow-up studies will determine if there are other rate limiting downstream steps in TCE metabolism in plants. Studies of the metabolism of carbon tetrachloride in poplar cells have provided evidence that the native plant metabolism is due to the activity of oxidative enzymes similar to the mammalian cytochrome P-450 2E1.

  2. Role of temperature and hydrochloric acid on the formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons during combustion of paraffin powder, polymers, and newspaper.

    Science.gov (United States)

    Takasuga, Takumi; Umetsu, Norihito; Makino, Tetsuya; Tsubota, Katsuya; Sajwan, Kenneth S; Kumar, Kurunthachalam Senthil

    2007-07-01

    Formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were determined using a laboratory-scale incinerator when combusting materials at different temperatures, different concentrations of hydrochloric acid (HCl), and when combusting various types of polymers/newspaper. Polychlorobenzenes (PCBz), polychlorophenols (PCPhs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and their toxic equivalency (TEQ) and PAHs were highlighted and reported. Our results imply maximum formation of chlorinated hydrocarbons at 400 degrees C in the following order; PCBz>or=PCPhs>PCDFs>PCDDs>TEQ on a parts-per-billion level. Similarly, a maximum concentration of chlorinated hydrocarbons was noticed with an HCl concentration at 1000 ppm with the presence of paraffin powder in the following order; PAHs>PCBz>or=PCPhs>PCDFs>PCDDs>TEQ an a parts-per-billion level. PAHs were not measured at different temperatures. Elevated PAHs were noticed with different HCl concentrations and paraffin powder combustion (range: 27-32 microg/g). While, different polymers and newspaper combusted, nylon and acrylonitrile butadiene styrene (ABS) produced the maximum hydrogen cyanide (HCN) concentration, concentrations of PCDD/FS, dioxin-like polychlorinated biphenyls (DL-PCBs), and TEQ were in a decreasing order: polyvinylchloride (PVC)ABS = blank. Precursors of PCBs were in a decreasing order: PPABSABSABSABS< PET

  3. Volatile Short-chain Chlorinated Hydrocarbons in the Groundwater of the City of Zagreb

    Directory of Open Access Journals (Sweden)

    Marijanović-Rajčić, M.

    2008-01-01

    Full Text Available The aim of the study was to assess the quality of the groundwater sampled from private wells and the public water-supply system in terms of estimating the contamination caused by short-chain chlorinated hydrocarbons, as well as to estimate the exposure of the citizens dwelling in different suburbs to these pollutants of their drinking water (Fig. 1. The aim of the study was also to determine which suburb is supplied through the public water-supply system with water originating from the Sašnak spring that is contaminated with volatile chlorinated short-chain hydrocarbons.Drinking water samples were taken from 3 private wells and 1 public water-supply system situated in 3 Zagreb suburbs - Pešćenica, Trnje, and Trešnjevka. The sampling was carried out during 2003 and was undertaken on a seasonal basis. Short-chain chlorinated hydrocarbons - 1,1,1-trichloroethane, carbon tetrachloride, 1,1,2-trichloroethene and 1,1,2,2-tetrachloroethene - were determined by gas chromatography, following "liquid-liquid extraction" in pentane. For that purpose, we applied the gas chromatograph equipped with an electron-capture detector, thermo-programmable operations, and a suitable capillary column. The technique applied was that of split-injection.The groundwater of the City of Zagreb was found to be contaminated with volatile chlorinated hydrocarbons. The concentration level of 1,1,1-trichloroethane, determined in most of the samples, was found to be low (Fig. 2. On the other hand, 1,1,2-trichloroethene was present in all samples in concentrations of about 1 µg l-1- (Fig. 3. Only the drinking water samples taken from private wells in the suburb of Trnje contained somewhat higher mass concentrations of 1,1,1-trichloroethane, with the peak value of 19.03 µg l-1, measured in the winter season. In the samples taken from private wells in Trnje, the mass concentrations of 1,1,2,2-tetrachloroethene rangedfrom 15.30 µg l-1 to 18.65 µg l-1, as measured in autumn

  4. Evidence for in situ production of chlorinated polycyclic aromatic hydrocarbons on tidal flats: environmental monitoring and laboratory scale experiment.

    Science.gov (United States)

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

    2012-07-01

    This study investigated environmental distributions and production mechanisms of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) in the sediments from some tidal flats located in Asia. Cl-PAHs were found in sediments taken from Arao tidal flat, Kikuchigawa River and Shirakawa River. The range of ∑Cl-PAHs was from 25.5 to 483 pg g(-1) for Kikuchigawa River and Arao tidal flat, respectively. Concentrations of PAHs and Cl-PAHs showed no significant correlations (r=0.134). This result suggests that the origins of these compounds differ. In the identified Cl-PAH isomers, the most abundant Cl-PAH isomer was 9,10-dichloroanthracene (9,10-di-Cl-ANT) in the three sites. In general, concentrations of Cl-ANTs in the coastal environment are about 3-5 orders of magnitude lower than those of anthracene (ANT). However, concentration ratios between Cl-ANTs and ANT (Cl-ANTs/ANT) in the sediments ranged from 4.1% to 24.6%. This result indicated that Cl-PAHs were not generated under industrial processes but the high concentration ratios have resulted from the contribution of photochemical production of Cl-ANTs in the sediments because ANT is known to have high photochemical reactivity. For examining this phenomenon, ANT adsorbed onto glass beads was irradiated with UV under the mimicked field conditions of tidal flats. As a result, it was noticed that, while chlorinated derivatives were negligible in a light-controlled group, production of 2-Cl-ANT, 9-Cl-ANT and 9,10-diCl-ANT on the irradiated surface were found in this study. These results suggest that photochemical reaction of PAHs can be a potential source of the occurrence of Cl-PAHs in the coastal environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Chlorine

    Science.gov (United States)

    ... phosphorus List by Category Chemical-Specific Fact Sheets Toxicology FAQs Case Definitions Toxic Syndrome Descriptions Toxicological Profiles ... cloth, but it is also used to make pesticides (insect killers), rubber, and solvents. Chlorine is used ...

  6. Monitoring of Chlorinated Hydrocarbon Pollution of Meat and Fish in Croatia

    Directory of Open Access Journals (Sweden)

    Jelena Vukušić

    2002-01-01

    Full Text Available Four hundred and sixty-six fatty tissue samples of beef, pork, poultry and fish were assayed by the gas and liquid chromatography between 1992 and 1996 for chlorinated hydrocarbons: hexachlorobenzene (HCB, α-hexachlorocyclohexane (α-HCH, γ-hexachlorocyclohexane (lindane, DDT and metabolites, and total polychlorinated biphenyls (PCBs. Samples were divided into two groups, meat and fish imported to Croatia, and meat from Croatian farms and fish from the Adriatic Sea. In domestic meat, the levels of pollution with the compounds studied were considerably lower than in imported meats. The differences were most noticeable in lindane and DDT levels in beef, and those of DDT in pork. The average level of lindane in domestic and imported beef was 0.004 and 0.020 mg/kg, respectively. Domestic beef contained on the average 0.013 mg/kg and the imported beef 0.059 mg/kg DDT, respectively. While the average amount of DDT in local pork was 0.014 mg/kg, the average for imported pork was 0.041 mg/kg. Poultry lindane also showed significant differences, an average of 0.012 mg/kg in domestic and 0.034 mg/kg in imported poultry. HCB and α-HCH displayed a statistically significant difference in beef. There was an average level of 0.001 mg/kg of HCB and 0.001 mg/kg of α-HCH. However, imported beef had an average of 0.004 mg/kg of HCB and 0.002 mg/kg of α-HCH. A significant difference was also found in HCB content in poultry; domestic and imported poultry contained an average of 0.001 and 0.003 mg/kg, respectively. As regards the pollution of fish with polychlorinated biphenyls, this was considerably higher in the fish of domestic origin (average of 0.046 mg/kg than in imported fish (average level of 0.006 mg/kg. Conversely, in both sample groups the pollution of fish with chlorinated pesticides was similar. Compared with meat and fish of the same origin and standing that were analyzed by our laboratory 10 years ago, the pollution of domestic meat and fish with

  7. Chlorine

    Science.gov (United States)

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical chlorine, produced in small quantities in the laboratory, is presented. The profile summarizes physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  8. Microbial diversity in a hydrocarbon- and chlorinated-solvent- contaminated aquifer undergoing intrinsic bioremediation

    Science.gov (United States)

    Dojka, M.A.; Hugenholtz, P.; Haack, S.K.; Pace, N.R.

    1998-01-01

    A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons (mainly jet fuel) and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes were amplified directly from aquifer material DNA by PCR with universally conserved or Bacteria- or Archaea-specific primers and were cloned. A total of 812 clones were screened by restriction fragment length polymorphisms (RFLP), approximately 50% of which were unique. All RFLP types that occurred more than once in the libraries, as well as many of the unique types, were sequenced. A total of 104 (94 bacterial and 10 archaeal) sequence types were determined. Of the 94 bacterial sequence types, 10 have no phylogenetic association with known taxonomic divisions and are phylogenetically grouped in six novel division level groups (candidate divisions WS1 to WS6); 21 belong to four recently described candidate divisions with no cultivated representatives (OPS, OP8, OP10, and OP11); and 63 are phylogenetically associated with 10 well-recognized divisions. The physiology of two particularly abundant sequence types obtained from the methanogenic zone could be inferred from their phylogenetic association with groups of microorganisms with a consistent phenotype. One of these sequence types is associated with the genus Syntrophus; Syntrophus spp. produce energy from the anaerobic oxidation of organic acids, with the production of acetate and hydrogen. The organism represented by the other sequence type is closely related to Methanosaeta spp., which are known to be capable of energy generation only through aceticlastic methanogenesis. We hypothesize, therefore, that the terminal step of hydrocarbon degradation in the methanogenic zone of the aquifer is aceticlastic methanogenesis and

  9. Treatment of petroleum hydrocarbon polluted environment through bioremediation: a review.

    Science.gov (United States)

    Singh, Kriti; Chandra, Subhash

    2014-01-01

    Bioremediation play key role in the treatment of petroleum hydrocarbon contaminated environment. Exposure of petroleum hydrocarbon into the environment occurs either due to human activities or accidentally and cause environmental pollution. Petroleum hydrocarbon cause many toxic compounds which are potent immunotoxicants and carcinogenic to human being. Remedial methods for the treatment of petroleum contaminated environment include various physiochemical and biological methods. Due to the negative consequences caused by the physiochemical methods, the bioremediation technology is widely adapted and considered as one of the best technology for the treatment of petroleum contaminated environment. Bioremediation utilizes the natural ability of microorganism to degrade the hazardous compound into simpler and non hazardous form. This paper provides a review on the role of bioremediation in the treatment of petroleum contaminated environment, discuss various hazardous effects of petroleum hydrocarbon, various factors influencing biodegradation, role of various enzymes in biodegradation and genetic engineering in bioremediation.

  10. Possible role of reactive chlorine in microbial antagonism and organic matter chlorination in terrestrial environments

    NARCIS (Netherlands)

    Bengtson, P.; Bastviken, D.; De Boer, W.; Öberg, G.

    2009-01-01

    Several studies have demonstrated that extensive formation of organically bound chlorine occurs both in soil and in decaying plant material. Previous studies suggest that enzymatic formation of reactive chlorine outside cells is a major source. However, the ecological role of microbial-induced

  11. Microbiota associated with the migration and transformation of chlorinated aliphatic hydrocarbons in groundwater.

    Science.gov (United States)

    Guan, Xiangyu; Liu, Fei; Xie, Yuxuan; Zhu, Lingling; Han, Bin

    2013-08-01

    Pollution of groundwater with chlorinated aliphatic hydrocarbons (CAHs) is a serious environmental problem which is threatening human health. Microorganisms are the major participants in degrading these contaminants. Here, groundwater contaminated for a decade with CAHs was investigated. Numerical simulation and field measurements were used to track and forecast the migration and transformation of the pollutants. The diversity, abundance, and possible activity of groundwater microbial communities at CAH-polluted sites were characterized by molecular approaches. The number of microorganisms was between 5.65E+05 and 1.49E+08 16S rRNA gene clone numbers per liter according to quantitative real-time PCR analysis. In 16S rRNA gene clone libraries constructed from samples along the groundwater flow, eight phyla were detected, and Proteobacteria were dominant (72.8 %). The microbial communities varied with the composition and concentration of pollutants. Meanwhile, toluene monooxygenases and methane monooxygenases capable of degradation of PCE and TCE were detected, demonstrating the major mechanism for PCE and TCE degradation and possibility for in situ remediation by addition of oxygen in this study.

  12. Speciation of volatile aromatic and chlorinated hydrocarbons in an urban atmosphere using TCT-GC/MS.

    Science.gov (United States)

    Baroja, O; Rodríguez, E; de Balugera, Z Gomez; Goicolea, A; Unceta, N; Sampedro, C; Alonso, A; Barrio, R J

    2005-01-01

    Several aromatic and chlorinated volatile hydrocarbons (VOCs) were measured in Vitoria-Gasteiz City (Spain) throughout the years 1999 and 2002 in order to find out the concentration of these pollutants in urban air. These VOCs were retained in Tenax TA, subsequently desorpted by using a thermal desorption cold trap injector (TCT), and thereafter analyzed by gas chromatography/mass spectrometry (GC/MS). This analytical methodology permits the determination of 42 VOCs at very low concentrations, although only 32 of them were found in the urban air of the city (ranging from 205.51 to 0.01 microg m(-3)), with high reproducibility (%RSD lower than 10%). Twenty-four-hour samples were taken each sampling day to ascertain their total daily concentration, and rigorous quality controls were carried out to check the representativeness of sampling. Results of this exhaustive study show that toluene (T), xylenes (X), ethylbenzene (E), and benzene (B) were, respectively, the most abundant of these VOCs in the urban area during that period. The total concentration of BTEX represented, on average, more than 72.6% of the VOC total concentration, with the highest concentrations being reached in autumn, except for benzene and derived compounds (in winter). Benzene was the minority BTEX pollutant, its yearly mean concentration being less than the maximum established by the European Directive 2000/69/CE (5 microg m(-3)).

  13. Direct immunofluorescence and enzyme-linked immunosorbent assays for evaluating chlorinated hydrocarbon degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.L.; Franck, M.M.; Brey, J.; Fliermans, C.B. [Westinghouse Savannah River, Aiken, SC (United States). Environmental Biotechnology Section; Scott, D.; Lanclos, K. [Medical Coll. of Georgia, Augusta, GA (United States)

    1997-06-01

    Immunological procedures were developed to enumerate chlorinated hydrocarbon degrading bacteria. Polyclonal antibodies (Pabs) were produced by immunizing New Zealand white rabbits against 18 contaminant-degrading bacteria. These included methanotrophic and chlorobenzene (CB) degrading species. An enzyme-linked immunosorbent assay (ELISA) was used to test for specificity and sensitivity of the Pabs. Direct fluorescent antibodies (DFAs) were developed with these Pabs against select methanotrophic bacteria isolated from a trichloroethylene (TCE) contaminated landfill at the Savannah River Site (SRS) and cultures from the American Type Culture Collection (ATCC). Analysis of cross reactivity testing data showed some of the Pabs to be group specific while others were species specific. The threshold of sensitivity for the ELISA is 105 bacteria cells/ml. The DFA can detect as few as one bacterium per ml after concentration. Results from the DFA and ELISA techniques for enumeration of methanotrophic bacteria in groundwater were higher but not significantly different (P < 0.05) compared to indirect microbiological techniques such as MPN. These methods provide useful information on in situ community structure and function for bioremediation applications within 1--4 hours of sampling.

  14. Alterations of phytoplankton assemblages treated with chlorinated hydrocarbons: effects of dominant species sensitivity and initial diversity.

    Science.gov (United States)

    Bácsi, István; Gonda, Sándor; B-Béres, Viktória; Novák, Zoltán; Nagy, Sándor Alex; Vasas, Gábor

    2015-05-01

    Changes in composition of phytoplankton assemblages due to short-chained chlorinated hydrocarbons (tetrachloroethane, tetrachloroethylene and trichloroethylene) were studied in microcosm experiments with different initial diversities. Diversity decreased further during treatments in the less diverse 2011 summer assemblages, dominated by the euglenid Trachelomonas volvocinopsis (its relative abundance was nearly 70 %). Diversity did not change significantly during treatments in the more diverse 2012 summer assemblages, dominated by cryptomonads (their relative abundance was 40 %). The dominant Trachelomonas volvocinopsis in 2011, due to its insensitivity to the treatment and presumably high competition skills, filled released habitats occurring when sensitive species were not detectable any more. In contrast, cryptomonads were extremely sensitive to the treatments, their abundance decreased under detection limit in the treated assemblages, regardless of diversity conditions. Our results showed that population dynamics of dominant species determine the response to the contamination of the entire community, if these species display high resistance or resilience. If the dominant species was highly sensitive and recovered slowly, compensatory growth of rare species maintained high levels of ecosystem performance.

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

    Science.gov (United States)

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

    2016-12-01

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

  16. Chlorinated Hydrocarbon Degradation in Plants: Mechanisms and Enhancement of Phytoremediation of Groundwater Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Strand

    2004-09-27

    The research objectives for this report are: (1) Transform poplar and other tree species to extend and optimize chlorinated hydrocarbon (CHC) oxidative activities. (2) Determine the mechanisms of CHC oxidation in plants. (3) Isolate the genes responsible for CHC oxidation in plants. We have made significant progress toward an understanding of the biochemical mechanism of CHC transformation native to wild-type poplar. We have identified chloral, trichloroethanol, trichloroacetic acid, and dichloroacetic acid as products of TCE metabolism in poplar plants and in tissue cultures of poplar cells.(Newman et al. 1997; Newman et al. 1999) Use of radioactively labeled TCE showed that once taken up and transformed, most of the TCE was incorporated into plant tissue as a non-volatile, unextractable residue.(Shang et al. 2001; Shang and Gordon 2002) An assay for this transformation was developed and validated using TCE transformation by poplar suspension cells. Using this assay, it was shown that two different activities contribute to the fixation of TCE by poplar cells: one associated with cell walls and insoluble residues, the other associated with a high molecular weight, heat labile fraction of the cell extract, a fixation that was apparently catalyzed by plant enzymes.

  17. Influence of Plants on Chlorine Cycling in Terrestrial Environments

    Science.gov (United States)

    Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David

    2016-04-01

    Chlorine (Cl), one of the 20 most abundant elements on Earth, is crucial for life as a regulator of cellular ionic strength and an essential co-factor in photosynthesis. Chlorinated organic compounds (Clorg) molecules are surprisingly abundant in soils, in fact many studies during the last decades show that Clorg typically account for more than 60% of the total soil Cl pool in boreal and temperate forest soils and frequently exceed chloride (Cl-) levels. The natural and primarily biotic formation of this Clorg pool has been confirmed experimentally but the detailed content of the Clorg pool and the reasons for its high abundance remains puzzling and there is a lack of Cl budgets for different ecosystems. Recently, the radioisotope 36Cl has caused concerns because of presence in radioactive waste, a long half-life (301 000 years), potential high mobility, and limited knowledge about Cl residence times, speciation and uptake by organisms in terrestrial environments. The chlorination of organic molecules may influence the pool of available Cl- to organisms and thereby the Cl cycling dynamics. This will prolong residence times of total Cl in the soil-vegetation system, which affects exposure times in radioactive 36Cl isotope risk assessments. We tested to what extent the dominating tree species influences the overall terrestrial Cl cycling and the balance between Cl- and Clorg. Total Cl and Clorg were measured in different tree compartments and soil horizons in the Breuil experimental forest, Bourgogne, established in 1976 and located at Breuil-Chenue in Eastern France. The results from this field experiment show how the dominating tree species affected Cl cycling and accumulation over a time period of 30 years. Cl uptake by trees as well as content of both total Cl and Clorg in soil humus was much higher in experimental plots with coniferous forests compared to deciduous forests. The amounts of Clorg found in plant tissue indicate significant Clorg production inside

  18. Analytical method development using functionalized polysulfone membranes for the determination of chlorinated hydrocarbons in water.

    Science.gov (United States)

    Nuhu, Abdulmumin A; Basheer, Chanbasha; Abu-Thabit, Nedal Y; Alhooshani, Khalid; Al-Arfaj, Abdul Rahman

    2011-12-15

    In this study, functionalized polysulfone membrane has been utilized as a sorbent for the extraction of chlorinated hydrocarbons (CHCs) in water samples. Two different functionalized polysulfones (i) phosphonic acid functionalized polysulfone (PPSU-A) with different forms (cross-linked and non cross-linked) membranes and (ii) phosphonic ester functionalized polysulfone (PPSU-E) with different forms (cross-linked and non cross-linked) were evaluated for the extraction of CHCs in water. A 10 ml of spiked water sample was extracted with 50mg piece of the functionalized membrane. After extraction, the membrane was desorbed by organic solvent and the extract was analyzed by gas chromatography-mass spectrometry. Eight CHCs, 1,3,5-trichlorobenzene (1,3,5-TCB), 1,2,3-trichlorobenzene (1,2,3-TCB), 1,1,2,3,4,4-hexachloro-1,3-butadiene (HCBD), 1,2,4-trichloro-3-methylbenzene (TCMB), 1,2,3,4-tetrachlorobenzene (1,2,3,4-TeCB), 1,2,4,5-tetrachlorobenzene (1,2,4,5-TeCB), pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) were used as model compounds. Experimental parameters such as extraction time, desorption time, types of polymer membrane as well the nature of desorption solvent were optimized. Using optimum extraction conditions calibration curves were linear with coefficients of determination between 0.9954 and 0.9999 over wide range of concentrations (0.05-100 μgl(-1)). The method detection limits (at a signal-to-noise ratio of 3) were in the range of 0.4-3.9 ng l(-1). The proposed method was evaluated for the determination of CHCs in drinking water samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Site-specific probabilistic ecological risk assessment of a volatile chlorinated hydrocarbon-contaminated tidal estuary.

    Science.gov (United States)

    Hunt, James; Birch, Gavin; Warne, Michael St J

    2010-05-01

    Groundwater contaminated with volatile chlorinated hydrocarbons (VCHs) was identified as discharging to Penrhyn Estuary, an intertidal embayment of Botany Bay, New South Wales, Australia. A screening-level hazard assessment of surface water in Penrhyn Estuary identified an unacceptable hazard to marine organisms posed by VCHs. Given the limitations of hazard assessments, the present study conducted a higher-tier, quantitative probabilistic risk assessment using the joint probability curve (JPC) method that accounted for variability in exposure and toxicity profiles to quantify risk (delta). Risk was assessed for 24 scenarios, including four areas of the estuary based on three exposure scenarios (low tide, high tide, and both low and high tides) and two toxicity scenarios (chronic no-observed-effect concentrations [NOEC] and 50% effect concentrations [EC50]). Risk (delta) was greater at low tide than at high tide and varied throughout the tidal cycle. Spatial distributions of risk in the estuary were similar using both NOEC and EC50 data. The exposure scenario including data combined from both tides was considered the most accurate representation of the ecological risk in the estuary. When assessing risk using data across both tides, the greatest risk was identified in the Springvale tributary (delta=25%)-closest to the source area-followed by the inner estuary (delta=4%) and the Floodvale tributary (delta=2%), with the lowest risk in the outer estuary (delta=0.1%), farthest from the source area. Going from the screening level ecological risk assessment (ERA) to the probabilistic ERA changed the risk from unacceptable to acceptable in 50% of exposure scenarios in two of the four areas within the estuary. The probabilistic ERA provided a more realistic assessment of risk than the screening-level hazard assessment. Copyright (c) 2010 SETAC.

  20. Assessment of the chlorinated hydrocarbons residues contamination in edible mushrooms from the North-Eastern part of Poland.

    Science.gov (United States)

    Gałgowska, Michalina; Pietrzak-Fiećko, Renata; Felkner-Poźniakowska, Barbara

    2012-11-01

    The aim of the study was to determine the content of chlorinated hydrocarbon residues in edible mushrooms from the north-eastern part of Poland. Material consisted of two species of fungi: Xerocomus mushrooms (Xerocomus badius), Boletus mushrooms (Boletus edulis). The dried samples (cups and cut-up material) were extracted with Soxhlet method in order to obtain lipid substances. In the fat chlorinated hydrocarbons were determined by Ludwicki et al. (1996) method. The separation and quantitative determination of DDT, DDE, DDD and γ-HCH were conducted with the method of gas chromatography using an electron capture detector - ECD. In all tested samples the presence of γ-HCH, DDT and its metabolites (DDE, DDD) was detected. The higher content of γ-HCH was found in Xerocomus mushrooms (average 0.125 μg/kg of mushrooms); in the Boletus mushrooms -0.11 μg/kg of mushrooms. The content of ΣDDT in cups of Xerocomus mushrooms was more than 2-fold higher than in those of Boletus mushrooms (3.78:1.71 mg/kg of mushrooms). The opposite relationship was observed for cut-up material. The higher concentration of ΣDDT was found in Boletus mushrooms (2.26 mg/kg of mushrooms) while in Xerocomus mushrooms this content was 0.91 mg/kg of mushrooms. Despite the fact that chlorinated hydrocarbons were determined in all samples under study, their contents do not exceed acceptable levels indicating that the consumption of mushrooms does not pose a health risk to consumers from the organochlorine compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Soil bioremediation approaches for petroleum hydrocarbon polluted environments

    Directory of Open Access Journals (Sweden)

    Eman Koshlaf

    2017-01-01

    Full Text Available Increasing industrialisation, continued population growth and heavy demand and reliance on petrochemical products have led to unprecedented economic growth and development. However, inevitably this dependence on fossil fuels has resulted in serious environmental issues over recent decades. The eco-toxicity and the potential health implications that petroleum hydrocarbons pose for both environmental and human health have led to increased interest in developing environmental biotechnology-based methodologies to detoxify environments impacted by petrogenic compounds. Different approaches have been applied for remediating polluted sites with petroleum derivatives. Bioremediation represents an environmentally sustainable and economical emerging technology for maximizing the metabolism of organic pollutants and minimizing the ecological effects of oil spills. Bioremediation relies on microbial metabolic activities in the presence of optimal ecological factors and necessary nutrients to transform organic pollutants such as petrogenic hydrocarbons. Although, biodegradation often takes longer than traditional remediation methods, the complete degradation of the contaminant is often accomplished. Hydrocarbon biodegradation in soil is determined by a number of environmental and biological factors varying from site to site such as the pH of the soil, temperature, oxygen availability and nutrient content, the growth and survival of hydrocarbon-degrading microbes and bioavailability of pollutants to microbial attack. In this review we have attempted to broaden the perspectives of scientists working in bioremediation. We focus on the most common bioremediation technologies currently used for soil remediation and the mechanisms underlying the degradation of petrogenic hydrocarbons by microorganisms.

  2. SIMULATION OF PERFORMANCE OF CHLORINE-FREE FLURORINATED ETHERS AND FLUORINATED HYDROCARBONS TO REPLACE CFC-11 AND CFC-114 IN CHILLERS

    Science.gov (United States)

    The paper discusses simulation of the performance of chlorine-free fluorinated ethers and fluorinated hydrocarbons as potential long-term replacements for CFC-11 and -114. Modeling has been done with in-house refrigeration models based on the Carnahan-Starling-DeSantis Equation o...

  3. A biogeochemical transport model to simulate the attenuation of chlorinated hydrocarbon contaminant fluxes across the groundwater-surface water interface

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Binning, Philip John; Albrechtsen, Hans-Jørgen

    2009-01-01

    Chlorinated hydrocarbons originating from point sources are amongst the most prevalent contaminants of ground water and surface water resources. Riparian zones may play an important role in the attenuation of contaminant concentrations when contaminant plumes flow from groundwater to surface water...... because of the occurrence of redox gradients, strongly reductive conditions and high biological activity. In order to meet the expectations of the EU Water Framework Directive, an evaluation of the impact of such plumes on surface water is needed. The aim of this work is to develop a groundwater transport...... number of geochemical processes, allows the simulation of soil geochemical transformations when microbial by-products are released to surface water, and the consideration of non-linear feedbacks on bacterial growth and pollutant transformations. Sensitivity analysis is performed through Monte Carlo...

  4. Assessing risks of hydrocarbon spills in tropical environments

    Science.gov (United States)

    Makarynskyy, Oleg; Makarynska, Dina; Negri, Andrew

    2017-04-01

    There is a growing pressure of exposure to petroleum hydrocarbons in tropical northern Australia. This is due to increasing population and industrial activities, such as oil and gas extraction, ship traffic, and related planned (e.g. wastewater) and accidental (e.g. spills) discharges. Through close collaboration between AIMS and AECOM, a novel, integrated approach to spill risk assessments has been developed. The approach links outcomes of a semi-quantitative risk assessment methodology to results of spill weathering and trajectory numerical modelling and to emerging tropical toxicological data. The risk assessment is based on triple bottom line concept and uses a multi-disciplinary expert panel to assess the probabilities and consequential impacts associated with potential risk events, such as accidental hydrocarbon spills. The probability assessments of spills are based on the type of operations being assessed and historical spill data available for the area and region. Quantifying the impacts of hydrocarbon spills requires an understanding of the impact extents as well as of the sensitivity of relevant tropical species to both hydrocarbons and dispersants. The quantification of impacts for certain operations and areas may only rely on the known nature of hydrocarbons, while spill volumes and extents of slick propagation are highly variable. Critical ecotoxicity data for tropical environments are scarce. Consequentially, assessments of probabilities and impacts may differ dramatically depending on the ambient conditions taken into consideration, level of understanding of properties of spilled hydrocarbon, and numerical models and techniques employed for simulating oil weathering and slick trajectories and thicknesses, as well as the available ecotoxicology thresholds of affected species. The outcomes of the combined risk and impact assessments for the first time provide industry and regulators with advanced pre-spill information thus vastly improving the

  5. Occurrence, profiles, and toxic equivalents of chlorinated and brominated polycyclic aromatic hydrocarbons in E-waste open burning soils.

    Science.gov (United States)

    Nishimura, Chiya; Horii, Yuichi; Tanaka, Shuhei; Asante, Kwadwo Ansong; Ballesteros, Florencio; Viet, Pham Hung; Itai, Takaaki; Takigami, Hidetaka; Tanabe, Shinsuke; Fujimori, Takashi

    2017-06-01

    We conducted this study to assess the occurrence, profiles, and toxicity of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs) in e-waste open burning soils (EOBS). In this study, concentrations of 15 PAHs, 26 Cl-PAHs and 14 Br-PAHs were analyzed in EOBS samples. We found that e-waste open burning is an important emission source of Cl-PAHs and Br-PAHs as well as PAHs. Concentrations of total Cl-PAHs and Br-PAHs in e-waste open burning soil samples ranged from 21 to 2800 ng/g and from 5.8 to 520 ng/g, respectively. Compared with previous studies, the mean of total Cl-PAH concentrations of the EOBS samples in this study was higher than that of electronic shredder waste, that of bottom ash, and comparable to fly ash from waste incinerators in Korea and Japan. The mean of total Br-PAH concentrations of the EOBS samples was generally three to four orders of magnitude higher than those in incinerator bottom ash and comparable to incinerator fly ash, although the number of Br-PAH congeners measured differed among studies. We also found that the Cl-PAH and Br-PAH profiles were similar among all e-waste open burning soil samples but differed from those in waste incinerator fly ash. The profiles and principal component analysis results suggested a unique mechanism of Cl-PAH and Br-PAH formation in EOBS. In addition, the Cl-PAHs and Br-PAHs showed high toxicities equivalent to PCDD/Fs measured in same EOBS samples when calculated based on their relative potencies to benzo[a]pyrene. Along with chlorinated and brominated dioxins and PAHs, Cl-PAHs and Br-PAHs are important environmental pollutants to investigate in EOBS. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Microbiological investigations on the elimination of volatile chlorinated hydrocarbons. Final report. Mikrobiologische Untersuchungen zur Elimination leichtfluechtiger Chlorkohlenwasserstoffe durch Biofilme. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Scholz-Muramatsu, H.

    1989-03-01

    The anaerobic elimination of 1,1,1-trichloroethane (TCA), trichloroethene (TCE) and tetrachlorethene (PCE) was studied under batch conditions and in a fixed bed reactor (concentrations of the chlorinated compounds 50 to 200 {mu}mol/l). Co-substrates for the anaerobic elimination of the chlorinated hydrocarbons were hydrogen, glucose, and benzoate. With glucose (2 mmol/l) PCE was dehalogenated to DCE (25 {mu}mol/m{sup 2}xh). PCE was eliminated to unchlorinated compounds under batch conditions with hydrogen as co-substrate (5 {mu}mol/lxd). In continuous culture with benzoate (2 to 4 mmol/l) PCE was dechlorinated to low concentrations of DCE or even totally as long as there was active methanogenesis. Under batch conditions TCA was dechlorinated completely with glucose as well as with benzoate (1,5 to 5 {mu}mol/lxd). PCE could be eliminated to DCE by fermenting bacteria without methanogenesis. The inhibiting factors for the elimination of dichloromethane (DCM) by groundwater contaminated with leachate of a laquer sludge landfill were studied. About 50% of the inhibiting substances belonged to the volatile fraction of the ground-water. Selected compounds out of this fraction were examined in regard to there inhibiting effect on the DCM elimination rate. A distinct inhibition was caused by 1,2-dichloroethane, ethylbenzene, and xylene. The DCM elimination was most sensitive against 1,2-dichloroethane. Besides this the leachate contained nonvolatile inhibitors which could not be identified. (orig.) With 42 refs., 12 tabs., 11 figs.

  7. High Molecular Weight Petrogenic and Pyrogenic Hydrocarbons in Aquatic Environments

    Science.gov (United States)

    Abrajano, T. A., Jr.; Yan, B.; O'Malley, V.

    2003-12-01

    Geochemistry is ultimately the study of sources, movement, and fate of chemicals in the geosphere at various spatial and temporal scales. Environmental organic geochemistry focuses such studies on organic compounds of toxicological and ecological concern (e.g., Schwarzenbach et al., 1993, 1998; Eganhouse, 1997). This field emphasizes not only those compounds with potential toxicological properties, but also the geological systems accessible to the biological receptors of those hazards. Hence, the examples presented in this chapter focus on hydrocarbons with known health and ecological concern in accessible shallow, primarily aquatic, environments.Modern society depends on oil for energy and a variety of other daily needs, with present mineral oil consumption throughout the 1990s exceeding 3×109 t yr-1 (NRC, 2002). In the USA, e.g., ˜40% of energy consumed and 97% of transportation fuels are derived from oil. In the process of extraction, refinement, transport, use, and waste production, a small but environmentally significant fraction of raw oil materials, processed products, and waste are released inadvertently or purposefully into the environment. Because their presence and concentration in the shallow environments are often the result of human activities, these organic materials are generally referred to as "environmental contaminants." Although such reference connotes some form of toxicological or ecological hazard, specific health or ecological effects of many organic "environmental contaminants" remain to be demonstrated. Some are, in fact, likely innocuous at the levels that they are found in many systems, and simply adds to the milieu of biogenic organic compounds that naturally cycle through the shallow environment. Indeed, virtually all compounds in crude oil and processed petroleum products have been introduced naturally to the shallow environments as oil and gas seepage for millions of years ( NRC, 2002). Even high molecular weight (HMW) polyaromatic

  8. Microbe-assisted phytoremediation of hydrocarbons in estuarine environments.

    Science.gov (United States)

    Oliveira, Vanessa; Gomes, Newton C M; Almeida, Adelaide; Silva, Artur M S; Silva, Helena; Cunha, Ângela

    2015-01-01

    Estuaries are sinks for various anthropogenic contaminants, such as petroleum hydrocarbons, giving rise to significant environmental concern. The demand for organisms and processes capable of degrading pollutants in a clean, effective, and less expensive process is of great importance. Phytoremedition approaches involving plant/bacteria interactions have been explored as an alternative, and halophyte vegetation has potential for use in phytoremedition of hydrocarbon contamination. Studies with plant species potentially suitable for microbe-assisted phytoremediation are widely represented in scientific literature. However, the in-depth understanding of the biological processes associated with the re-introduction of indigenous bacteria and plants and their performance in the degradation of hydrocarbons is still the limiting step for the application of these bioremediation solutions in a field context. The intent of the present review is to summarize the sources and effects of hydrocarbon contamination in estuarine environments, the strategies currently available for bioremediation (potential and limitations), and the perspectives of the use of halophyte plants in microbe-assisted phytoremediation approaches.

  9. Bacterial oxidation of low-chlorinated compounds under anoxic conditions

    NARCIS (Netherlands)

    Dijk, J.A.

    2005-01-01

    Chlorinated hydrocarbons belong to the most frequently encountered contaminants in soil and groundwater. Many of them were found to be toxic and recalcitrant, which causes a potential threat to the environment. Therefore, it is of great importance that sites contaminated with chlorinated

  10. California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, Mexico, than in California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Del Toro, Ligeia [Universidad Autonoma de Baja California (UABC), Facultad de Ciencias Marinas, Ensenada, Baja California (Mexico); Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico); Heckel, Gisela [Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico) and Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, B.C. Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California 22860 (Mexico)]. E-mail: gheckel@cicese.mx; Camacho-Ibar, Victor F. [Instituto de Investigaciones Oceanologicas, UABC, Apdo. Postal 453, Ensenada, Baja California 22860 (Mexico); Schramm, Yolanda [Universidad Autonoma de Baja California (UABC), Facultad de Ciencias Marinas, Ensenada, Baja California (Mexico); Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico)

    2006-07-15

    Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, Mexico, January 2000-November 2001. {sigma}DDTs were the dominant group (geometric mean 3.8 {mu}g/g lipid weight), followed by polychlorinated biphenyls ({sigma}PCBs, 2.96 {mu}g/g), chlordanes (0.12 {mu}g/g) and hexachlorocyclohexanes (0.06 {mu}g/g). The {sigma}DDTs/{sigma}PCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north. - Results suggest that sea lion prey must also have lower hydrocarbons in Baja California than in California in the USA.

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

    Science.gov (United States)

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

    2013-07-02

    In this study, we hypothesize that natural photochemical reactions of polycyclic aromatic hydrocarbons (PAHs) in tidal flats are responsible for the occurrence of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs). This study aims to survey the impact of photochemical reactions using a combination of field surveys and lab-scale experiments. Concentrations and profiles of PAHs and Cl-PAHs in road dust and sediments collected from seven tunnels and two watersheds, respectively, were determined. In the lab-scale experiments, anthracene was irradiated with ultraviolet (UV) light under various salinity conditions. No detectable Cl-PAHs were found in the road dust. However, Cl-PAHs were detected in the sediments from 700 to 6.1 × 10(3) pg g(-1) and specifically from downstream sites. 2-Monochloroanthracene (2-Cl-ANT) and 9,10-dichloroanthracene (9,10-di-Cl-ANT) were dominant in the sediments. In the Domen River watershed, the ∑Cl-PAHs and the salinity showed a significant positive correlation (p PAHs. 2-Cl-ANT, 9-monochloroanthracene, and 9,10-di-Cl-ANT were identified as transformation products in the UV irradiation experiments. Production of these Cl-PAHs was dependent on the solution salinity. These results support our hypothesis, and we conclude that photochemical reactions significantly contribute to the occurrence of Cl-PAHs in the studied tidal flats.

  12. Natural attenuation of chlorinated-hydrocarbon contamination at Fort Wainwright, Alaska; a hydrogeochemical and microbiological investigation workplan

    Science.gov (United States)

    McCarthy, Kathleen A.; Lilly, Michael R.; Braddock, Joan F.; Hinzman, Larry D.

    1998-01-01

    Natural attenuation processes include biological degradation, by which microorganisms break down contaminants into simpler product compounds; adsorption of contaminants to soil particles, which decreases the mass of contaminants dissolved in ground water; and dispersion, which decreases dissolved contaminant concentrations through dilution. The primary objectives of this study are to (1) assess the degree to which such natural processes are attenuating chlorinated-hydrocarbon contamination in ground water, and (2) evaluate the effects of ground-water/surface-water interactions on natural-attenuation processes in the area of the former East and West Quartermasters Fueling Systems for Fort Wainwright, Alaska. The study will include investigations of the hydrologic, geochemical, and microbiological processes occurring at this site that influence the transport and fate of chlorinated hydrocarbons in ground water. To accomplish these objectives, a data-collection program has been initiated that includes measurements of water-table elevations and the stage of the Chena River; measurements of vertical temperature profiles within the subsurface; characterization of moisture distribution and movement in the unsaturated zone; collection of ground-water samples for determination of both organic and inorganic chemical constituents; and collection of ground-water samples for enumeration of microorganisms and determination of their potential to mineralize contaminants. We will use results from the data-collection program described above to refine our conceptual model of hydrology and contaminant attenuation at this site. Measurements of water-table elevations and river stage will help us to understand the magnitude and direction of ground-water flow and how changes in the stage of the Chena River affect ground-water flow. Because ambient ground water and surface water typically have different temperature characteristics, temperature monitoring will likely provide further insight

  13. Simulation of ground-water flow and transport of chlorinated hydrocarbons at Graces Quarters, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, Frederick J.; Fleck, William B.

    2001-01-01

    Military activity at Graces Quarters, a former open-air chemical-agent facility at Aberdeen Proving Ground, Maryland, has resulted in ground-water contamination by chlorinated hydrocarbons. As part of a ground-water remediation feasibility study, a three-dimensional model was constructed to simulate transport of four chlorinated hydrocarbons (1,1,2,2-tetrachloroethane, trichloroethene, carbon tetrachloride, and chloroform) that are components of a contaminant plume in the surficial and middle aquifers underlying the east-central part of Graces Quarters. The model was calibrated to steady-state hydraulic head at 58 observation wells and to the concentration of 1,1,2,2-tetrachloroethane in 58 observation wells and 101direct-push probe samples from the mid-1990s. Simulations using the same basic model with minor adjustments were then run for each of the other plume constituents. The error statistics between the simulated and measured concentrations of each of the constituents compared favorably to the error statisticst,1,2,2-tetrachloroethane calibration. Model simulations were used in conjunction with contaminant concentration data to examine the sources and degradation of the plume constituents. It was determined from this that mixed contaminant sources with no ambient degradation was the best approach for simulating multi-species solute transport at the site. Forward simulations were run to show potential solute transport 30 years and 100 years into the future with and without source removal. Although forward simulations are subject to uncertainty, they can be useful for illustrating various aspects of the conceptual model and its implementation. The forward simulation with no source removal indicates that contaminants would spread throughout various parts of the surficial and middle aquifers, with the100-year simulation showing potential discharge areas in either the marshes at the end of the Graces Quarters peninsula or just offshore in the estuaries. The

  14. Structures and Nuclear Quadrupole Coupling Tensors of a Series of Chlorine-Containing Hydrocarbons

    Science.gov (United States)

    Dikkumbura, Asela S.; Webster, Erica R.; Dorris, Rachel E.; Peebles, Rebecca A.; Peebles, Sean A.; Seifert, Nathan A.; Pate, Brooks

    2016-06-01

    Rotational spectra for gauche-1,2-dichloroethane (12DCE), gauche-1-chloro-2-fluoroethane (1C2FE) and both anti- and gauche-2,3-dichloropropene (23DCP) have been observed using chirped-pulse Fourier-transform microwave (FTMW) spectroscopy in the 6-18 GHz region. Although the anti conformers for all three species are predicted to be more stable than the gauche forms, they are nonpolar (12DCE) or nearly nonpolar (predicted dipole components for anti-1C2FE: μ_a = 0.11 D, μ_b = 0.02 D and for anti-23DCP: μ_a = 0.25 D, μ_b = 0.02 D); nevertheless, it was also possible to observe and assign the spectrum of anti-23DCP. Assignments of parent spectra and 37Cl and 13C substituted isotopologues utilized predictions at the MP2/6-311++G(2d,2p) level and Pickett's SPCAT/SPFIT programs. For the weak anti-23DCP spectra, additional measurements also utilized a resonant-cavity FTMW spectrometer. Full chlorine nuclear quadrupole coupling tensors for gauche-12DCE and both anti- and gauche-23DCP have been diagonalized to allow comparison of coupling constants. Kraitchman's equations were used to determine r_s coordinates of isotopically substituted atoms and r_0 structures were also deduced for gauche conformers of 12DCE and 1C2FE. Structural details and chlorine nuclear quadrupole coupling constants of all three molecules will be compared, and effects of differing halogen substitution and carbon chain length on molecular properties will be evaluated.

  15. Effect of vegetation in pilot-scale horizontal subsurface flow constructed wetlands treating sulphate rich groundwater contaminated with a low and high chlorinated hydrocarbon.

    Science.gov (United States)

    Chen, Zhongbing; Wu, Shubiao; Braeckevelt, Mareike; Paschke, Heidrun; Kästner, Matthias; Köser, Heinz; Kuschk, Peter

    2012-10-01

    In order to characterize the effect of vegetation on performance of constructed wetlands (CWs) treating low and high chlorinated hydrocarbon, two pilot-scale horizontal subsurface flow (HSSF) CWs (planted with Phragmites australis and unplanted) treating sulphate rich groundwater contaminated with MCB (monochlorobenzene, as a low chlorinated hydrocarbon), (about 10 mg L(-1)), and PCE (perchloroethylene, as a high chlorinated hydrocarbon), (about 2 mg L(-1)), were examined. With mean MCB inflow load of 299 mg m(-2) d(-1), the removal rate was 58 and 208 mg m(-2) d(-1) in the unplanted and planted wetland, respectively, after 4 m from the inlet. PCE was almost completely removed in both wetlands with mean inflow load of 49 mg m(-2) d(-1). However, toxic metabolites cis-1,2-DCE (dichloroethene) and VC (vinyl chloride) accumulated in the unplanted wetland; up to 70% and 25% of PCE was dechlorinated to cis-1,2-DCE and VC after 4 m from the inlet, respectively. Because of high sulphate concentration (around 850 mg L(-1)) in the groundwater, the plant derived organic carbon caused sulphide formation (up to 15 mg L(-1)) in the planted wetland, which impaired the MCB removal but not statistically significant. The results showed significant enhancement of vegetation on the removal of the low chlorinated hydrocarbon MCB, which is probably due to the fact that aerobic MCB degraders are benefited from the oxygen released by plant roots. Vegetation also stimulated completely dechlorination of PCE due to plant derived organic carbon, which is potentially to provide electron donor for dechlorination process. The plant derived organic carbon also stimulated dissimilatory sulphate reduction, which subsequently have negative effect on MCB removal. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  16. Comment on 'inflow, levels and the fate of some persistent chlorinated hydrocarbons in the Rijeka Bay area of the Adriatic Sea by N. Picer and M. Picer'

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    in their methodology pertaining to the extraction of pollutant from the aquatic medium since they have contradicted themselves by reporting that several seawater samples were also analysed by concentrating the pollutant with Amberlite XAD-2 resin. However, they have... the extent of contamination of the region under investigation. (3) Another ambiguity in their methodology is that the retained chlorinated hydrocarbons were eluted with methanol only and re-extracted with pentane which has obviously resulted in significant...

  17. Gas-particle phase partitioning and particle size distribution of chlorinated and brominated polycyclic aromatic hydrocarbons in haze.

    Science.gov (United States)

    Jin, Rong; Zheng, Minghui; Yang, Hongbo; Yang, Lili; Wu, Xiaolin; Xu, Yang; Liu, Guorui

    2017-12-01

    Chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) are emerging semi-volatile organic pollutants in haze-associated particulate matter (PM). Their gas-particle phase partitioning and distribution among PM fractions have not been clarified. Clarification would increase understanding of atmospheric behavior and health risks of Cl/Br-PAHs. In this study, samples of the gas phase and 4 PM phases (aerodynamic diameters (dae) > 10 μm, 2.5-10 μm, 1.0-2.5 μm, and distribution indicated that the Cl/Br-PAHs tended to adhere to fine particles. Over 80% of the Cl-PAHs and 70% of the Br-PAHs were associated with fine PM (dae particle phase partitioning and PM distribution of Cl/Br-PAHs when heating of buildings was required, which was associated with haze events, were obviously different from those when heating was not required. The relationship between the logarithmic geometric mean diameters of the Cl/Br-PAH congeners and reciprocal of the temperature (1/T) suggested that low air temperatures during the heating period could lead to high proportions of Cl/Br-PAHs in the fine particles. Increased coal burning during the heating period also contributed to high Cl/Br-PAH loads in the fine particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Local and seasonal variations in concentrations of chlorinated polycyclic aromatic hydrocarbons associated with particles in a Japanese megacity.

    Science.gov (United States)

    Ohura, Takeshi; Kamiya, Yuta; Ikemori, Fumikazu

    2016-07-15

    Concentrations of particle-bound polycyclic aromatic hydrocarbons (PAHs) and chlorinated PAHs (ClPAHs) were measured in different seasons at five sampling stations in Nagoya, a Japanese megacity. The annual mean total ClPAH and total PAH concentrations were 43.3-92.6pg/m(3) and 5200-8570pg/m(3), respectively. The concentrations of total ClPAHs were significantly variable than those of total PAHs, and both total concentrations through the seasons did not significantly correlate at any of the stations. Principal component analysis was used to characterize the ClPAH sources, resulted that ClPAHs were found to be associated with the sources of high-molecular-weight PAHs in the warmer seasons and of low-molecular-weight PAHs in the colder seasons. These findings suggest that principal sources of particle-bound ClPAHs are present in the local area, and change in the seasons. Toxic equivalent (TEQ) concentrations were estimated to assess the risks associated with exposure to ClPAHs in air. The TEQ concentrations in the samples were 0.05-0.32pg-TEQ/m(3). The TEQ concentrations in summer were approximately half the TEQ concentrations in the other seasons at all of the stations. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Development of a standard reference material containing 22 chlorinated hydrocarbon gases at 1 μmol/mol in nitrogen.

    Science.gov (United States)

    Li, Ning; Du, Jian; Yang, Jing; Fan, Qiang; Tian, Wen

    2017-11-01

    A gas standard mixture containing 22 chlorinated hydrocarbons in high purity nitrogen was prepared using a two-step weighing method and a gasifying apparatus developed in-house. The concentration of each component was determined using a gas chromatograph with flame ionization detection (GC/FID). Linear regression analysis of every component was performed using the gas standard mixture with concentrations ranging from 1 to 10 μmol/mol, showing the complete gasification of volatile organic compound (VOCs) species in a selected cylinder. Repeatability was also examined to ensure the reliability of the preparation method. In addition, no significant difference was observed between domestic treated and imported treated cylinders, which were conducive to reduction of the cost of raw materials. Moreover, the results of stability testing at different pressures and long-term stability tests indicated that the gas standard at 1 μmol/mol level with relative expanded uncertainties of 5% was stable above 2 MPa for a minimum of 12 months. Finally, a quantity comparison was conducted between the gas standard and a commercial gas standard from Scott Specialty Gases (now Air Liquide America Specialty Gases). The excellent agreement of every species suggested the favorable accuracy of our gas standard. Therefore, this reference material can be applied to routine observation of VOCs and for other purposes.

  20. Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

    Science.gov (United States)

    2013-01-01

    Background The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%. PMID:23289764

  1. Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

    Directory of Open Access Journals (Sweden)

    Olek Malgorzata

    2013-01-01

    Full Text Available Abstract Background The process of thermal decomposition of dichloromethane (DCM and chlorobenzene (MCB during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%.

  2. Theoretical modeling of biodegradation and biotransformation of hydrocarbons in subsurface environments.

    Science.gov (United States)

    Corapcioglu, M Y; Hossain, M A

    1990-02-22

    Hydrocarbons such as TCE, PCE, TCA, gasoline and kerosene which are widely used in the industry, enter soils and groundwater from chemical waste disposal sites and from accidents. These types of substances are the most commonly encountered groundwater contaminants nationwide. Biotransformation of dissolved chlorinated hydrocarbons can provide complete mineralization to harmless end products such as CO2. It is the objective of this work to investigate the biodegradation and biotransformation, and transport of hydrocarbons in groundwater. This will be achieved first by defining and identifying relevant physical and biological processes which contribute to the fate of hydrocarbon contaminants in unsaturated/saturated soils, and providing a conceptual framework for incorporating these processes into a mathematical formulation. The conservation principles expressed in terms of quantifications of the physical, chemical and microbial processes described above lead to a system governing the phenomenon which consists of nonlinear partial differential equations. Microbial transformation conducted by both anaerobic and aerobic bacteria are considered.

  3. Reproductive and morphological condition of wild mink (Mustela vison) and river otters (Lutra canadensis) in relation to chlorinated hydrocarbon contamination.

    Science.gov (United States)

    Harding, L E; Harris, M L; Stephen, C R; Elliott, J E

    1999-01-01

    We assessed chlorinated hydrocarbon contamination of mink and river otters on the Columbia and Fraser River systems of northwestern North America, in relation to morphological measures of condition. We obtained carcasses of mink and river otters from commercial trappers during the winters 1994-1995 and 1995-1996. Necropsies included evaluation of the following biological parameters: sex, body mass and length, age, thymus, heart, liver, lung, spleen, pancreas, kidney, gonad, omentum, adrenal gland and baculum masses, baculum length, and stomach contents. Livers were analyzed, individually or in pools, for residues of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans. Contaminant levels were relatively low compared to those documented in other North American populations, although they ranged higher than those detected during an earlier survey (1990-1992) of these regional populations. Body condition varied slightly among collection regions, but showed no relationship with contaminant burden. Mink from the upper Fraser River had less fat stores and also had some of the lowest OC contamination levels observed. Similarly, a few individuals with enlarged livers and kidneys had low contaminant levels. Although a few individual animals with gross abnormalities of reproductive systems did not show high levels of contamination, there was a significant negative correlation between total PCB concentrations (as Aroclor 1260) and baculum length in juvenile mink (r = 0.707; p = 0.033; n = 8). The association of juvenile baculum length with eventual reproductive success is unknown, but further characterization of reproductive organ morphology and relationship to contaminants should be undertaken in a larger subset of these populations. Images Figure 1 Figure 2 Figure 3 PMID:9924010

  4. In Vitro Transformation of Chlorinated Parabens by the Liver S9 Fraction: Kinetics, Metabolite Identification, and Aryl Hydrocarbon Receptor Agonist Activity.

    Science.gov (United States)

    Terasaki, Masanori; Wada, Takeshi; Nagashima, Satoshi; Makino, Masakazu; Yasukawa, Hiro

    2016-01-01

    We investigated the kinetics of in vitro transformation of a dichlorinated propyl paraben (2-propyl 3,5-dichloro-4-hydroxybenzoate; Cl2PP) by the rat liver S9 fraction and assessed the aryl hydrocarbon receptor (AhR) agonist activity of the metabolite products identified in HPLC and GC/MS analysis and by metabolite syntheses. The results indicated that the chlorination of Cl2PP reduced its degradation rate by approximately 40-fold. Two hydroxylated metabolite products showed AhR agonist activity of up to 39% of that of the parent Cl2PP when assessed in a yeast (YCM3) reporter gene assay. The determination of the metabolic properties of paraben bioaccumulation presented here provides further information on the value of risk assessments of chlorinated parabens as a means to ensure human health and environmental safety.

  5. Genetic Engineering of Plants to Improve Phytoremediation of Chlorinated Hydrocarbons in Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Strand, Stuart E.

    2004-12-01

    I. Mechanism of halogenated hydrocarbon oxidation We are using poplar culture cells to determine the pathway of TCE metabolism. In our earlier work, we found that trichloroethanol (TCEOH) is a major early intermediate. Our studies this year have focused on the steps that follow this toxic intermediate. We did several experiments to track the disappearance of TCEOH after the cells were removed from TCE. We could conclude that TCEOH is not an end-product but is rapidly degraded. Six flasks of poplar liquid suspension cells were exposed to a level of 50 {micro}g/ml TCE for three days. Three of the cultures were subjected to MTBE extractions to quantify the levels of TCEOH produced. The cells of the remaining three cultures were then pelleted and resuspended in fresh medium. After three more days, these were also subjected to MTBE extractions. The samples were analyzed by GC-ECD. After the three days of further metabolism, an average of 91% of the trichloroethanol was gone. When similar experiments were done with intact plants and both free and conjugated TCEOH were quantified, a similar rapid decline in both forms was seen (Shang, 2001). Therefore, it seems probable that similar mechanisms are taking place in both poplar suspension cells and whole poplar plants, so we continued to do our studies with the suspension cells. Metabolism of trichloroethanol may go through trichloroacetic acid (TCAA) prior to dehalogenation. To test this possibility, we exposed cells to TCE and analyzed for TCAA over time. The cultures were analyzed after 4, 5, 6, and 14 days from TCE exposure. We did not detect any significant amount of TCAA above the background in undosed cells. To determine if trichloroethanol itself is directly dehalogenated, we analyzed TCE-exposed cells for the presence of dichloroethanol. Undosed cells did not have any of the DCEOH peak but TCE-dosed cells that produced the highest levels of trichloroethanol did have a small DCEOH peak. Cultures that did not produce

  6. Volatile Fuel Hydrocarbons and MTBE in the Environment

    Science.gov (United States)

    Cozzarelli, I. M.; Baehr, A. L.

    2003-12-01

    Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor

  7. Polycyclic aromatic hydrocarbons in the South American environment.

    Science.gov (United States)

    Barra, Ricardo; Castillo, Caroline; Torres, Joao Paulo Machado

    2007-01-01

    Pollution of the environment with polycyclic aromatic hydrocarbons (PAHs) should be a global concern, especially in urbanized areas. In South American countries, where notable increase in urban populations has been observed in the past few years, reliable information about the pollution status of these urban environments is not always easily accessible, and therefore an effort to collect updated information is required. This review attempts to contribute by analyzing the existing information regarding environmental levels of PAHs in some South American countries. A regional trend for environmental PAH information is an uneven contribution, because some countries, such as Bolivia, Peru, Paraguay, and Ecuador, have reported no information at all in the scientific literature, reflecting to a certain extent the different patterns of economic, technical, and scientific development. PAH air monitoring is one of the areas that has received the most attention during the last few years, mainly in Brazil, Chile, and Argentina, where data represent a few geographical areas within the region. PAH levels in air from some urban areas in Argentina, Brazil, and Chile, considered moderate to high (100-1000ng/m3), are probably among the highest values reported in the open literature. Urbanization, vehicle pollution, and wood fires are the principal contributors to the high reported levels. In more temperate areas, a clear distinction is observed between summer and winter levels. PAH monitoring in soils is very limited within the region, with few data available, and most information indicates widespread pollution. In Brazil, values for many representative ecosystems were found. In Chile, data from forestry and agricultural areas indicate in general low concentrations, in spite of a relatively high detection frequency. Pollution levels in soils are highly dependent on their closeness to PAH sources and certain cultural practices (agricultural burnings, forest fires, etc.). Water PAH

  8. Biochar as a sorbent for chlorinated hydrocarbons - sorption and extraction experiments in single and bi-solute systems

    Science.gov (United States)

    Schreiter, Inga J.; Wefer-Roehl, Annette; Graber, Ellen R.; Schüth, Christoph

    2017-04-01

    Biochar (BC) is increasingly deemed a potential sorbent for contaminants in soil and water remediation, and brownfield restoration. In this study, sorption and extraction experiments were performed to assess the potential of three different BCs to sorb and retain the chlorinated hydrocarbons trichloroethylene (TCE) and tetrachloroethylene (PCE). BCs studied were produced from wood chips, grain husk, and cattle manure at 450 °C. A commercially available activated carbon (AC) served as a reference. The sorption behaviour was studied in batch experiments in single solute and bi-solute systems. Resulting isotherms were fitted to the Freundlich model. To assess the desorption behaviour, a five-step extraction scheme (water at 40°C, water at 80°C, methanol at 50°C, toluene at 50°C, and n-hexane at 50°) was developed, utilizing Accelerated Solvent Extraction. Isotherms revealed distinct differences in sorption behaviour depending on BC feedstock. Sorption capacity ranked as follows: wood chip BC > grain husk BC > cattle manure BC for both contaminants. This sequence could be attributable to an increasing specific surface area, an increasing amount of carbon, and a decreasing ash content of the sorbents. It is noteworthy that all three BCs were more effective in adsorbing TCE, which is surprising, given the higher logKow of PCE. The reverse was observed for the AC. Here, sorption is purely driven by the hydrophobicity of the compound rather than sorbent properties. In bi-solute experiments, PCE sorbed as good as or stronger than TCE, yet the total mass of sorbed compounds increased slightly. In contrast, AC showed a significant decrease of TCE sorption and no significant changes in the total mass sorbed. Extraction experiments revealed that for all BCs a large fraction of the contaminants could not be readily desorbed. In all cases, water remobilized < 5 % of the total contaminant mass and up to 70 % could not be extracted by any of the solvents. The findings suggest

  9. Concentrations of chlorinated hydrocarbons and trace elements in marine mammal tissues archived in the U.S. National Biomonitoring Specimen Bank.

    Science.gov (United States)

    Becker, P R; Mackey, E A; Demiralp, R; Schantz, M M; Koster, B J; Wise, S A

    1997-05-01

    The U.S. National Biomonitoring Specimen Bank (NBSB) provides for the long term storage of well documented and preserved specimens representing several types of environmental matrices. A major part of this inventory consists of marine mammal tissues (e.g., blubber, liver, kidney, and muscle). Within the NBSB selected specimens are periodically analyzed for chlorinated hydrocarbons and trace elements. Although only 20% of the 560 marine mammal specimens in the NBSB have been analyzed, the database is of value in evaluating the stability of analytes and sample degradation during storage, for comparing with results from samples collected in the future for long-term monitoring, and for comparing with analytical results from other laboratories on samples collected at the same time for monitoring purposes. The NBSB analytical database contains results for 37 elements, many of which are not analyzed routinely by conventional analytical techniques used in monitoring programs, and the following organic compounds: selected PCB congeners. DDT compounds, alpha- and gamma-HCH, HCB, heptachlor epoxide, oxychlordane, cis-chlordane, trans-chlordane, cis-nonachlor, trans-nonachlor, and dieldrin in 9 marine mammal species: northern fur seal (Callorhinus ursinus), ringed seal (Phoca hispida), spotted seal (P. largha), bearded seal (Erignathus barbatus), pilot whale (Globicephala melas), harbor porpoise (Phocoena phocoena), white-sided dolphin (Lagenorhynchus acutus), beluga whale (Delphinapterus leucas), and bowhead whale (Balaena mysticetus). Analyses of beluga whale blubber for toxaphene and additional chlorinated hydrocarbons are obtained through collaboration with the Department of Fisheries and Oceans Canada.

  10. Recent research activities and future subjects on stable- and radio-isotopes of chlorine in environment

    Energy Technology Data Exchange (ETDEWEB)

    Kushita, Kouhei [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    This report reviews the recent studies on the stable- and radio-isotopes of chlorine from a viewpoint of environmental science, partly including historic references on this element. First, general properties, occurrence, and utilization of chlorine are described. Secondly, current status and research works on chlorine-compounds, which attract special attention in recent years as environmentally hazardous materials, are reported. Thirdly, research works on stable chlorine isotopes, {sup 35}Cl and {sup 37}Cl, are described with a focus laid on the newly-developed techniques; isotopic ratio mass spectrometry (IRMS) and thermal ionization mass spectrometry (TIMS). Fourthly, recent research works on chlorine radioisotopes, {sup 36}Cl etc., are described, focusing on the development of accelerator mass spectrometry (AMS) and its application to geochemistry and others. Finally, taking account of the above-mentioned recent works on Cl isotopes, possible future research subjects are discussed. (author)

  11. Trihalomethanes formation in marine environment in front of Nuweibaa desalination plant as a result of effluents loaded by chlorine residual

    Directory of Open Access Journals (Sweden)

    Mohamed A. Hamed

    2017-03-01

    Full Text Available Trihalomethanes have been identified as the most important disinfection byproducts resulted from using chlorine in desalination plants. Nuweibaa desalination plant was chosen to study their effluents impacts on the marine environment in front of the plant in the coastal area of Gulf of Aqaba. Surface and bottom Water Samples were collected from nine locations in the outfall area of this desalination plant during spring and autumn 2014, and analyzed for water temperature, pH value, Salinity, Dissolved Oxygen, Biological oxygen demand, Oxidizible organic matter, Total, fixed and volatile suspended matter, residual chlorine (free and combined and trihalomethanes. High total chlorine dosage discharged from the desalination plant achieved high levels of trihalomethanes in the receiving seawater of the outfall area. It has been estimated that about 14524.65671 kg of BOD, 74123.4 kg of OOM, 166896.4375 kg of total suspended solids, 623.634 kg of free chlorine, 469.21 kg of combined chlorine, 206.64 kg of chloroform and 76.48 kg of bromoform are discharged annually from this plant into the Gulf of Aqaba affecting the marine ecosystems. The results of THMs showed that the two main forms of THMs formed in the receiving seawater were chloroform and bromoform and ranged between (5.09–156.59, (2.82–566.06 μg/L respectively. High pH and High combined chlorine concentrations favored the formation of high concentrations of chloroform.

  12. Chlorinated hydrocarbons in livers of American mink (Mustela vison) and river otter (Lutra canadensis) from the Columbia and Fraser River Basins, 1990-1992

    Science.gov (United States)

    Elliott, J.E.; Henny, Charles J.; Harris, M.L.; Wilson, L.K.; Norstrom, R.J.

    1999-01-01

    We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990-91 and 1991a??92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978a??79 and 1990a??92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.

  13. The behavior of SiC and Si3N4 ceramics in mixed oxidation/chlorination environments

    Science.gov (United States)

    Marra, John E.; Kreidler, Eric R.; Jacobson, Nathan S.; Fox, Dennis S.

    1989-01-01

    The behavior of silicon-based ceramics in mixed oxidation/chlorination environments was studied. High pressure mass spectrometry was used to quantitatively identify the reaction products. The quantitative identification of the corrosion products was coupled with thermogravimetric analysis and thermodynamic equilibrium calculations run under similar conditions in order to deduce the mechanism of corrosion. Variations in the behavior of the different silicon-based materials are discussed. Direct evidence of the existence of silicon oxychloride compounds is presented.

  14. Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Treatability of volatile chlorinated hydrocarbon-contaminated soils of different textures along a vertical profile by mechanical soil aeration: A laboratory test.

    Science.gov (United States)

    Ma, Yan; Shi, Yi; Hou, Deyi; Zhang, Xi; Chen, Jiaqi; Wang, Zhifen; Xu, Zhu; Li, Fasheng; Du, Xiaoming

    2017-04-01

    Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons (VCHs). Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures (silty, clayey, and sandy soils) along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform (TCM) and trichloroethylene (TCE). Mechanical soil aeration was effective for remediating VCHs (removal efficiency >98%). The volatilization process was described by an exponential kinetic function. In the early stage of treatment (0-7hr), rapid contaminant volatilization followed a pseudo-first order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner. Copyright © 2016. Published by Elsevier B.V.

  16. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment.

    Science.gov (United States)

    Rabus, Ralf; Boll, Matthias; Heider, Johann; Meckenstock, Rainer U; Buckel, Wolfgang; Einsle, Oliver; Ermler, Ulrich; Golding, Bernard T; Gunsalus, Robert P; Kroneck, Peter M H; Krüger, Martin; Lueders, Tillmann; Martins, Berta M; Musat, Florin; Richnow, Hans H; Schink, Bernhard; Seifert, Jana; Szaleniec, Maciej; Treude, Tina; Ullmann, G Matthias; Vogt, Carsten; von Bergen, Martin; Wilkes, Heinz

    2016-01-01

    Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl)succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and

  18. Development of an analysis method for determining chlorinated hydrocarbons in marine sediments and suspended matter giving particular consideration to supercritical fluid extraction; Entwicklung eines Analysenverfahrens zur Bestimmung von chlorierten Kohlenwasserstoffen in marinen Sedimenten und Schwebstoffen unter besonderer Beruecksichtigung der ueberkritischen Fluidextraktion

    Energy Technology Data Exchange (ETDEWEB)

    Sterzenbach, D.

    1997-11-01

    The purpose of the present study was to develop an analysis method for chlorinate hydrocarbons in marine environments using supercritical fluid extraction (SFE) instead of conventional approaches. In order to apply this extraction method the available SFE device had to be extended and all the individual steps of the analysis method had to be optimised and adapted. As chlorinated hydrocarbons only occur at very low concentrations in marine environments (ppm to ppt range) the analysis method had to be extremely sensitive. High sensitivity, in town, is generally associated with a high susceptibility of an analysis method to faults through contamination or losses. This meant that the entire method and all its individual steps had to scrutinised for such weak points and improved where necessary. A method for sampling suspended matter in marine environments had to be developed which permits efficient separation of the smallest possible particles from seawater. The designated purpose of the developed analysis method is to deal with topical aspects of marine chemistry relating to sources, transport, distribution, and the fate of chlorinated hydrocarbons in marine environments. (orig.) [Deutsch] Ziel der vorliegenden Arbeit ist, ein Analysenverfahren fuer chlorierte Kohlenwasserstoffe in der marinen Umwelt zu entwickeln. Dabei soll die ueberkritische Fluidextraktion (SFE) anstelle herkoemmlicher Verfahren eingesetzt werden. Fuer die Anwendung dieser Extraktionsmethode ist es erforderlich, das zur Verfuegung stehende SFE-Geraet zu erweitern und saemtliche Teilschritte des Analysenverfahrens zu optimieren und auf diese Methode abzustimmen. Der Umstand, dass die chlorierten Kohlenwasserstoffe nur in sehr geringen Konzentrationen in der marinen Umwelt vorkommen (ppm- bis ppt-Bereich), erfordert eine sehr hohe Empfindlichkeit des Analysenverfahrens. Eine hohe Empfindlichkeit bedingt eine grosse Stoeranfaelligkeit des Analysenverfahrens durch Kontaminationen oder Verluste. Aus

  19. Investigations on potential bacteria for the bioremediation treatment of environments contaminated with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, I.; Voicu, A.; Dobrota, S.; Stefanescu, M. [Institute of Biology of Romanian Academy, Bucharest (Romania)] [and others

    1995-12-31

    In Romania after more than 135 years of oil production and processing, some severe environmental pollution problems have accumulated. In this context a joint research group from Institute of Biology Bucharest and S.C. Petrostar S.A. Ploiesti became involved in a research project on bioremediation of an environment contaminated with hydrocarbon waste. In the first stage of this project, investigations on microbial communities occurring in environments contaminated with oil were carried out. In the second stage, the hundreds of bacterial strains and populations isolated from soils, slops, and water sites contaminated with waste oil and water waste oil mix were submitted to a screening program, to select a naturally occurring mixed culture with a high ability to degrade hydrocarbons.

  20. Aqueous chlorination of resorcinol

    Science.gov (United States)

    Heasley, V.L.; Burns, M.D.; Kemalyan, N.A.; Mckee, T.C.; Schroeter, H.; Teegarden, B.R.; Whitney, S.E.; Wershaw, R. L.

    1989-01-01

    An investigation of the aqueous chlorination (NaOCl) of resorcinol is reported. The following intermediates were detected in moderate to high yield at different pH values and varying percentages of chlorination: 2-chloro-, 4-chloro-, 2,4-dichloro-, 4,6-dichloro- and 2,4,6-trichlororesorcinol. Only trace amounts of the intermediates were detected when the chlorination was conducted in the presence of phosphate buffer. This result has significant implications since resorcinol in phosphate buffer has been used as a model compound in several recent studies on the formation of chlorinated hydrocarbons during chlorination of drinking water. Relative rates of chlorination were determined for resorcinol and several of the chlorinated resorcinols. Resorcinol was found to chlorinate only three times faster than 2,4,6-trichlororesorcinol. The structure 2,4,6-trichlororesorcinol was established as a monohydrate even after sublimation. A tetrachloro or pentachloro intermediate was not detected, suggesting that the ring-opening step of such an intermediate must be rapid. ?? 1989.

  1. Mercury and persistent chlorinated hydrocarbons in owls Strigiformes and birds of prey Falconiformes collected in Norway during the period 1965-1983

    Energy Technology Data Exchange (ETDEWEB)

    Froeslie, A.; Holt, G.; Norheim, G.

    1986-01-01

    Levels of mercury and persistent chlorinated hydrocarbons were determined in the liver of dead birds of prey (N = 568) and owls (n = 310) collected in Norway in 1965-1983. The highest levels of mercury were found in osprey and white-tailed eagle, with median concentrations of 4.7 and 2.4 ..mu..g Hg g/sup -1/ liver respectively. The levels of DDE and PCB varied considerably, the highest levels of DDE being detected in white-tailed eagle and goshawk which had a median concentration of 2.0 and 1.9 ..mu..g DDEg/sup -1/ liver respectively. Highest levels of PCB were detected in osprey, gyr falcon and white-tailed eagle (5.0 ..mu..g PCBg/sup -1/). With a few exceptions the levels of HCB, ..gamma..-BHC and dieldrin detected were low. Mercury and organochlorine levels were also determined in unhatched eggs (n = 159) of raptorial birds collected in the same period. The levels of mercury were, with a few exceptions, low. The highest levels of DDE were found in eggs of merlin and sparrow hawk with median concentrations of 30 and 19 ..mu..g g/sup -1/ respectively, while the highest levels of PCB were found in eggs of white-tailed eagle and goshawk, with median concentrations of 13.9 and 12.3 ..mu..g PCB/sup -1/, respectively. It was not possible, from the present material, to demonstrate significant changes in contaminant levels over time. Nor was it possible to detect significant geographical differences. Although a very few samples of liver and eggs contained levels of mercury or organochlorines that might be considered toxic, the greater proportion of samples contained levels far below accepted critical limits.

  2. Formation and transformation of nitrated polycyclic aromatic hydrocarbons in the environment

    Directory of Open Access Journals (Sweden)

    Marzena Zaciera

    2014-03-01

    Full Text Available Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs belong to this group of compounds which reveal mutagenic and carcinogenic properties. These compounds are persistent in the environment, and long time exposure even at low concentrations can cause health effect dangerous to a human. The paper describes formation of nitro-PAHs in the air which is a complex process, depending on many factors (weather conditions, presence of other pollutants in the ambient air. The sources of nitro-PAHs formation migration and their transformation in the environment are presented.

  3. Site profiles of low-volatile chlorinated hydrocarbons - cause-oriented monitoring in aquatic media. Vol.2. Low-volatile chlorinated hydrocarbons in surface water, sediments, suspended matter and fish of the Elbe river and its tributaries; Standortprofile schwerfluechtiger chlorierter Kohlenwasserstoffe (SCKW) - ursachenorientiertes Monitoring in aquatischen Medien. Bd. 2. SCKW in Oberflaechenwasser, Sediment, Schwebstoffen und Fischen aus der Elbe und Nebenfluessen

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, E.; Kettrup, A.; Gebefuegi, I.; Martens, D.; Bergheim, W.; Wenzel, S.

    2001-07-01

    Evaluating the primary data from ARGE ELBE, LAU Halle/Saale and the Environmental Specimen Banking (Umweltprobenbank) as well from publications from the Czech Republic (CHMU) the concentrations of the following low volatile chlorinated hydrocarbons were established for surface water, sediment, breams and eels from the rivers Elbe, Schwarze Elster, Mulde and Saale partly from 1989 till 1999: DDT and its metabolites DDE and DDD, partly as 2,4'- and 4,4' isomers; HCH ({alpha}-, {beta}-, {gamma}- and {delta} isomers); chlorinated benzenes with 1-6 Cl atoms and octachlorostyrene. The data evaluated were drawn up into tables - comprehensive in a separate supplement, in short versions within the text - and consolidated into graphs. Aim of the paper was a cause-oriented monitoring. The by far most important emission sources, found from the distance and time profiles as well as from special assessments of the substance patterns, were chemical plants. (orig.) [German] Durch Auswertung von Primaerdaten der ARGE ELBE, des LAU Halle/Saale und der Umweltprobenbank sowie von Publikationen aus Tschechien (CHMU) wurden fuer Oberflaechenwasser, Sediment, Brassen/Bleien und Aale aus der Elbe, Schwarzen Elster, Mulde und Saale fuer die Jahre von z.T. 1989 bis 1999 die Konzentrationen der folgenden schwerfluechtigen Kohlenwasserstoffe (SCKW) ermittelt: DDT und seine Metabolite DDE und DDD, z.T. als 2,4'- und 4,4'-Isomere; HCH ({alpha}-, {beta}-, {gamma}- und {delta}-Isomere); chlorierte Benzole mit 1-6 Cl-Atomen und Octachlorstyrol. Die ausgewerteten Daten wurden zu Tabellen - ausfuehrlich in einem gesonderten Tabellenanhang und verkuerzt im Textteil - zusammengestellt sowie zu Grafiken verdichtet. Ziel der Arbeit war ein ursachenorientiertes Monitoring. Als mit Abstand wesentlichste Emissionsquellen konnten anhand von Streckenprofilen und Zeitrastern sowie durch spezielle Auswertungen der Stoffmusterverteilungen Chemibetriebe ermittelt werden. (orig.)

  4. Chlorine poisoning

    Science.gov (United States)

    Chlorine is a chemical that prevents bacteria from growing. Chlorine poisoning occurs when someone swallows or breathes in (inhales) chlorine. This article is for information only. Do NOT use it to ...

  5. Environmentally acceptable incineration of chlorinated chemical waste : Review of theory and practice

    NARCIS (Netherlands)

    De Zeeuw, M.A.; Lemkowitz, S.M.

    1987-01-01

    Chlorinated hydrocarbons in the form of chemical waste, represent a threat to the environment and public health of the world. Their proper handling, removal and destruction is critical to long term safety. Increasingly strict government legislation is leading to an increase in the quantity of

  6. Simultaneous determination of polycyclic aromatic hydrocarbons and their chlorination by-products in drinking water and the coatings of water pipes by automated solid-phase microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Tillner, Jocelyn; Hollard, Caroline; Bach, Cristina; Rosin, Christophe; Munoz, Jean-François; Dauchy, Xavier

    2013-11-08

    In this study, an automated method for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their chlorination by-products in drinking water was developed based on online solid-phase microextraction-gas chromatography-mass spectrometry. The main focus was the optimisation of the solid-phase microextraction step. The influence of the agitation rate, type of fibre, desorption time, extraction time, extraction temperature, desorption temperature, and solvent addition was examined. The method was developed and validated using a mixture of 17 PAHs, 11 potential chlorination by-products (chlorinated and oxidised PAHs) and 6 deuterated standards. The limit of quantification was 10 ng/L for all target compounds. The validated method was used to analyse drinking water samples from three different drinking water distribution networks and the presumably coal tar-based pipe coatings of two pipe sections. A number of PAHs were detected in all three networks although individual compositions varied. Several PAH chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also found, their presence correlating closely with that of their respective parent compounds. Their concentrations were always below 100 ng/L. In the coatings, all PAHs targeted were detected although concentrations varied between the two coatings (76-12,635 mg/kg and 12-6295 mg/kg, respectively). A number of chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also detected (from 40 to 985 mg/kg), suggesting that the reaction of PAHs with disinfectant agents takes place in the coatings and not in the water phase after migration. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Kinetic Studies of the Cometabolism of 1,4-DIOXANE and Chlorinated Aliphatic Hydrocarbon Mixtures by Rhodococcus Rhodochrous Grown on Isobutane

    Science.gov (United States)

    Rolston, H. M.; Semprini, L.; Thankitkul, S.; Azizian, M.; Hyman, M. R.

    2016-12-01

    1,4-dioxane (1,4-D) is a frequently observed groundwater contaminant due to its use as a stabilizer in commercial solvent formulations. In situ bioremediation could potentially provide a large cost savings for treatment of mixtures of chlorinated aliphatic hydrocarbons (CAHs) that include 1,4-D. Aerobic cometabolism is a particularly attractive option, as microorganisms can be stimulated in situ using specific primary substrates. Results will be presented that show the model isobutane-metabolizing bacteria, Rhodococcus rhodochrous (ATCC 21198), has the ability to transform 14-D at high rates and transformation capacities to concentrations below the drinking water screening level of 0.67 µg L-1. Resting cell transformation tests showed 1,4-D and a broad range of CAHs can be cometabolized by ATCC 21198. The maximum transformation rate (kmax) and the half-substrate coefficient (Ks) were determined for isobutane (the growth substrate), 1,4-D, 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2-trichloroethane (1,1,2-TCA), 1,1-dichloroethane (1,1-DCA); 1,2-dichloroethane ((1,2-DCA) and 1,1-dichloroethene (1,1-DCE). Of the CAHs tested, 1,1-DCA had the highest kmax, approximately 25% of that for isobutane utilization, while 1,1,1-TCA had the lowest kmax, approximately 2% of isobutane's. 1,4-D was rapidly transformed and had a kmax 25% of that of isobutane. ATCC 21198 effectively transformed mixtures of 1,4-D, 1,1-DCE, 1,2-DCA and 1,1,1-TCA, both in the presence and absence isobutane. Model simulations were performed for the simultaneous cometabolism of 1,4-D and CAH mixtures by ATCC 21198, that included inhibition among the contaminants and isobutane , and terms for a limited transformation capacity. A good match to experimental observations was obtaining using the independently measured rate parameters. Results of model simulations will also be presented using a reactive transport model to evaluate conditions of in situ bioremediation using strain ATCC 21198.

  8. The chemical modification and characterization of polypropylene membrane with environment response by in-situ chlorinating graft copolymerization

    Science.gov (United States)

    Zhang, Yue; Liu, Jiankai; Hu, Wenjie; Feng, Ying; Zhao, Jiruo

    2017-08-01

    In this study, a novel chemical surface modification method of polyolefin membranes is applied following the in-situ chlorinating graft copolymerization (ISCGC). Polypropylene (PP)/methyl methacrylate (MMA) system was used as an example. A unique structure was formed by the modification process on the original membrane surface and the product exhibited an environmental response. Chlorine free radicals were generated using ultraviolet and heat and were used to capture the hydrogen in the polymer chains on the substrate surface. The formed macromolecular radicals could react with MMA over 2 h to achieve a high coverage ratio polymer on the PP membrane surface. The graft copolymers were characterized using FTIR, 1H-NMR, DSC, and XPS, which all proved the feasibility of chemically modifying the PP membrane surface by ISCGC. The surface morphology of the grafted PP membrane was characterized using SEM and AFM. The results showed that the grafted product presents a uniform, neat, and dense mastoid structure with an average thickness of 4.44 μm, which was expected to be similar to the brush-like surface structure. The contact angle and AFM tests indicated that the product surface is responsive to solvent and pH. The experimental results showed that the PP membrane surface structure can be reconstructed using ISCGC, a method that can be used for environment-responsive polymer materials. Moreover, the product has the characteristics of polymer interfacial brush.

  9. Medium-chain chlorinated paraffins (MCCPs): a review of bioaccumulation potential in the aquatic environment.

    Science.gov (United States)

    Thompson, Roy; Vaughan, Martin

    2014-01-01

    Chlorinated paraffins (CPs) are high molecular weight organochlorine compounds that have been used in a variety of industrial applications for many years. Medium-chain chlorinated paraffins (MCCPs) (CAS 85535-85-9; Alkanes, C14-17 , chloro) are currently under investigation as potential persistent bioaccumulative toxic (PBT) compounds. In this article, the bioaccumulation potential of MCCPs is assessed using a tiered framework proposed after a recent Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop in 2008. The framework proposes the use of physicochemical properties and modeling assessment, bioconcentration/bioaccumulation (BCF/BAF) assessment, biomagnification (BMF) assessment, and trophic magnification factor (TMF) assessment. It is hoped that use of this framework could harmonize and improve the efficiency and effectiveness of the chemical substance evaluation screening process for PBT properties. When applied to MCCPs, the following conclusions were made: empirical physiochemical data is available negating the use of models; laboratory BCFs range from 1000 to 15 000 (growth-corrected lipid normalized values) for 2 MCCP structures; field BAFs were an order of magnitude higher than the trigger criterion for "B status possible"; although results may not meet acceptance criteria for field studies, laboratory-derived BMFs for a number of C14-17 chlorinated alkanes were less than the trigger value of 1 (based on whole-body concentrations) whereas field-derived BMFs were less than 1 (based on lipid corrected values [generally used for field data] excluding one measure for sculpin, [Cottus cognatus]-Diporeia that was based on only one detectable sample); and finally, TMFs were less than the trigger criterion value of 1, which are considered the most convincing evidence for bioaccumulative properties of a compound and the "Gold Standard" measure of bioaccumulation. This article also discusses the uncertainties surrounding the published data

  10. Sevoflurane as a therapy for acute chlorine gas exposure in an austere healthcare environment: a case report.

    Science.gov (United States)

    Bellenger, Sarah R; Frizzi, James D

    2014-06-01

    Chlorine is a common agent found worldwide in industrial and household applications. This element is found everywhere and anywhere around the globe. Because of its ubiquitous nature in the world, chlorine-injured patients may be expected at all medical facilities, from large-urban to small-community to austere-tent facilities. Chlorine has been used as a chemical weapon since 1915 and has been accidentally released in transport, storage, and use, causing industrial accidents worldwide. A patient with a history of severe chlorine inhalational injury sustained 2 chlorine gas exposures within 48 hours. The patient was treated with intubation, mechanical ventilation, and directed therapies for severe injury by chlorine gas inhalation. Sevoflurane has a role in treating chlorine inhalation injury. Additional therapies are possible, some of which are not available in remote locations.

  11. Gamma radiolysis of chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-01-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  12. Gamma radiolysis of chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-08-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  13. SAM Chlorine Observations at Gale Crater

    Science.gov (United States)

    Conrad, P. G.; Farley, K. A.; Vasconcelos, P. M.; Malespin, C.; Franz, H.; McAdam, A.; Sutter, B.; Stern, J. C.; Clark, B. C.; Atreya, S. K.; Mahaffy, P. R.; Martín-Torres, J.; Zorzano, M. P.

    2014-12-01

    The Sample Analysis at Mars investigation has detected Cl-bearing phases of various oxidation states in its thermally evolved gas measurements of both a wind drift deposit of fines and three different rock samples delivered as sieved drill powders to the instrument suite. In addition to HCl (Leshin et al, 2013; Ming et al, 2013) and chlorinated hydrocarbon detections (Glavin et al, 2013; Freissinet et al, in review), oxygen releases consistent with the decomposition of perchlorate salts are also observed. We have also measured chlorine isotope ratios of the four different solid samples, which yielded variable and more negative δ37Cl than typically observed in SNC meteorite analyses. We summarize our chlorine observations in the context of other gases observed in the SAM solid sample analyses, including water, sulfur- and nitrogen-bearing compounds, and REMS observations of Relative Humidity and Temperature, and compare with knowledge of martian chlorine obtained from the SNC meteorites. Finally, we examine the implications of surface/atmosphere Cl interactions and isotopic ratios for the rise and decline of habitable surface environments on Mars. This research was supported by the National Aeronautics and Space Administration (NASA) Mars Science Laboratory mission.

  14. Mid-IR laser absorption diagnostics for hydrocarbon vapor sensing in harsh environments

    Science.gov (United States)

    Klingbeil, Adam Edgar

    Fuel/air stoichiometry is an important parameter in modern combustion devices because it has a profound influence on efficiency, power, and pollutant formation. As engine technologies continue to advance, diagnostics and sensors are becoming essential for studying fundamental combustion processes and characterizing performance of combustion-based engines. Optical-absorption diagnostics have been used previously to probe various species in these environments and to infer quantities such as concentration, temperature, pressure, and velocity. However, there have been only a limited number of demonstrations of optical diagnostics for hydrocarbon fuels. This thesis describes the development of mid-IR optical-absorption sensors for time-resolved measurements of hydrocarbon species to infer critical parameters such as concentration and temperature. These sensors provide the necessary sensitivity and time resolution for measurements in shock tubes, pulse detonation engines, and internal combustion engines. Different aspects of the research conducted are summarized below. An FTIR spectrometer is used to measure the temperature-dependent absorption spectra of a selection of hydrocarbon species and blended fuels in the ˜3.3 mum region of the fundamental C-H stretching vibration. This spectroscopic library provides the first high-temperature spectral information for many of the species studied and facilitates development of sensitive diagnostics for various applications. This unique database also enables modelling of the absorption spectra of blended fuels such as gasoline. An ethylene and propane diagnostic is designed for measuring fuel concentration in a pulse detonation engine using a fixed-wavelength helium-neon laser. Time-resolved measurements during fired tests of a repetitively pulsed engine reveal non-ideal cycle-to-cycle interactions that cause a substantial amount of fuel to leave the engine unburned. By quantifying the fuel loading and identifying the amount of

  15. Reactions of silicon-based ceramics in mixed oxidation chlorination environments

    Science.gov (United States)

    Marra, John E.; Kreidler, Eric R.; Jacobson, Nathan S.; Fox, Dennis S.

    1988-01-01

    The reaction of silicon-based ceramics with 2 percent Cl2/Ar and 1 percent Cl2/1 percent to 20 percent O2/Ar at 950 C was studied with thermogravimetric analysis and high-pressure mass spectrometry. Pure Si, SiO2, several types of SiC, and Si3N4 were examined. The primary corrosion products were SiCl4(g) and SiO2(s) with smaller amounts of volatile silicon oxychlorides. The reactions appear to occur by chlorine penetration of the SiO2 layer, and gas-phase diffusion of the silicon chlorides away from the sample appears to be rate limiting. Pure SiO2 shows very little reaction with Cl2, SiC with excess Si is more reactive than the other materials with Cl2, whereas SiC with excess carbon is more reactive than the other materials with Cl2/O2. Si3N4 shows very little reaction with Cl2. These differences are explained on the basis of thermodynamic and microstructural factors.

  16. The Influence of Nitrogen Oxides on Chlorine Chemistry in Barrow, Alaska

    Science.gov (United States)

    McNamara, S. M.; Raso, A. R. W.; Wang, S.; Thanekar, S.; Fuentes, J. D.; Shepson, P. B.; Pratt, K.

    2016-12-01

    Active chlorine chemistry in the springtime Arctic boundary layer impacts the fate of atmospheric pollutants and greenhouse gases. Recent field studies have reported high amounts of molecular chlorine (Cl2), up to 400 parts per trillion (ppt), as well as the presence of chlorinated hydrocarbon oxidation products. However, our knowledge of Arctic chlorine chemistry is limited by a paucity of observations. The presence of nitrogen oxides (NOx) may influence the chlorine chemistry in this region. Here, we report chemical ionization mass spectrometry measurements of Cl2, chlorine monoxide (ClO), nitryl chloride (ClNO2), and dinitrogen pentoxide (N2O5), and NOx measurements at Barrow, AK during March-May 2016. To our knowledge, these data represent the first observations of ClNO2 in the Arctic. While the main source of NOx in a pristine Arctic environment is irradiated snow surfaces, anthropogenic sources can significantly enhance local NOx concentrations. The role of NOx in the activation and temporal trends of the reactive chlorine species are examined using a 0-D photochemical model. The prevalence of chlorine chemistry under elevated nitrogen oxide conditions may have significant impacts on the atmospheric composition in an increasingly polluted Arctic.

  17. Microbial transformation of chlorinated aromatics in sediments

    NARCIS (Netherlands)

    Beurskens, J.E.M.

    1995-01-01

    Numerous contaminants like heavy metals, polycyclic aromatic hydrocarbons (PAHs), chlorinated benzenes (CBs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p -dioxins (PCDDs) and polychlorinated furans (PCDFs) are detected in the major rivers in the

  18. Chlorinated paraffins in the environment: A review on their production, fate, levels and trends between 2010 and 2015.

    Science.gov (United States)

    van Mourik, Louise M; Gaus, Caroline; Leonards, Pim E G; de Boer, Jacob

    2016-07-01

    This review provides an update on information regarding the production volumes, regulations, as well as the environmental levels, trends, fate and human exposure to chlorinated paraffin mixtures (CPs). CPs encompas thousands congeners with varying properties and environmental fate. Based on their carbon chain lengths, CPs are divided into short- (SCCPs; C10-13), medium- (MCCPs; C14-17) and long- (LCCPs; C ≥ 18) chained groups. They are high production volume and persistent chemicals, and their cumulative global production already surpasses that of other persistent anthropogenic chemicals (e.g. PCBs). However, international regulations are still curbed by insufficient information on their levels and fate, including bioaccumulation and toxicity potential. An increasing number of studies since 2010 demonstrate that CPs are detected in almost every compartment in the environment, including remote areas. Consensus on the long range transport and high bioaccumulation potential (BCF > 5000 & TMF > 1) has recently been reached for SCCPs, fulfilling criteria under the Stockholm Convention for designation as a persistent organic pollutant; information on their levels is, however, still sparse for many countries. M/LCCPs have received comparatively little attention in the past, but as replacement chemicals for SCCPs, MCCPs are now considered in an increasing number of studies. The limited data to date suggests MCCPs are widely used. Although data on their bioaccumulation and toxicity are still inconclusive, MCCPs and LCCPs with C<20 may also have a bioaccumulation potential. Considering this and their high production volumes, use, and ubiquitous occurrence in the environment, a better understanding on the levels and fate of all CPs is needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Contamination of short-chain chlorinated paraffins to the biotic and abiotic environments in the Bohai Sea.

    Science.gov (United States)

    Jiang, Wanyanhan; Huang, Tao; Chen, Han; Lian, Lulu; Liang, Xiaoxue; Jia, Chenhui; Gao, Hong; Mao, Xiaoxuan; Zhao, Yuan; Ma, Jianmin

    2017-10-20

    Short-chain chlorinated paraffins (SCCPs) have been produced and emitted intensively around the Bohai Sea, potentially causing risks to this unique ecosystem and one of primary fishery resources in China and busiest seaways in the world. Little is known about fate, cycling, and sources of SCCPs in the Bohai Sea biotic and abiotic environment. In this study, we combined a marine food web model with a comprehensive atmospheric transport-multiple phase exchange model to quantify SCCPs in the biotic and abiotic environment in the Bohai Sea. We performed multiple modeling scenario investigations to examine SCCP levels in water, sediment, and phytoplankton. We assessed numerically dry and wet depositions, biomagnification and bioaccumulation of SCCPs in the Bohai Sea marine food web. Results showed declining SCCP levels in water and sediment with increasing distance from the coastline, and so do dry and wet depositions. The net deposition overwhelmed the water-air exchange of SCCPs due to their current use in China, though the diffusive gas deposition fluctuated monthly subject to mean wind speed and temperature. A risk assessment manifests that SCCPs levels in the Bohai Sea fish species are at present not posing risks to the residents in the Bohai Sea Rim region. We identified that the SCCP emission sources in the south of the Bohai Sea made a primary contribution to its loadings to the seawater and fish contamination associated with the East Asian summer monsoon. In contrast, the SCCP emissions from the north and northwest regions of the Bohai Sea were major sources contributing to their loading and contamination to Bohai Sea food web during the wintertime, potentially driven by the East Asian winter monsoon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Lacustrine Environment Reservoir Properties on Sandstone Minerals and Hydrocarbon Content: A Case Study on Doba Basin, Southern Chad

    Science.gov (United States)

    Sumery, N. F. Mohd; Lo, S. Z.; Salim, A. M. A.

    2017-10-01

    The contribution of lacustrine environment as the hydrocarbon reservoir has been widely known. However, despite its growing importance, the lacustrine petroleum geology has received far less attention than marine due to its sedimentological complexity. This study therefore aims in developing an understanding of the unique aspects of lacustrine reservoirs which eventually impacts the future exploration decisions. Hydrocarbon production in Doba Basin, particularly the northern boundary, for instance, has not yet succeeded due to the unawareness of its depositional environment. The drilling results show that the problems were due to the: radioactive sand and waxy oil/formation damage, which all are related to the lacustrine depositional environment. Detailed study of geological and petrophysical integration on wireline logs and petrographic thin sections analysis of this environment helps in distinguishing reservoir and non-reservoir areas and determining the possible mechanism causing the failed DST results. The interpretations show that the correlation of all types> of logs and rho matrix analysis are capable in identifying sand and shale bed despite of the radioactive sand present. The failure of DST results were due to the presence of arkose in sand and waxy oil in reservoir bed. This had been confirmed by the petrographic thin section analysis where the arkose has mineral twinning effect indicate feldspar and waxy oil showing bright colour under fluorescent light. Understanding these special lacustrine environment characteristics and features will lead to a better interpretation of hydrocarbon prospectivity for future exploration.

  1. On the formation of nitrogen-substituted polycyclic aromatic hydrocarbons (NPAHs) in circumstellar and interstellar environments.

    Science.gov (United States)

    Parker, Dorian S N; Kaiser, Ralf I

    2017-01-23

    The chemical evolution of extraterrestrial environments leads to the formation of polycyclic aromatic hydrocarbons (PAHs) via gas phase radical mediated aromatization reactions. We review that these de facto barrierless reactions are capable of forming prebiotic molecules such as nitrogen substituted PAHs (NPAHs), which represent the missing link between nitrogen bearing acyclic molecules and prebiotic nucleobases along with vitamins found in meteorites. Crucial routes leading to the incorporation of nitrogen atoms into the aromatic ring have been exposed. Pyridine can be formed from the reaction of abundant vinyl cyanide and its radical or via cyano radicals reacting with 1,3-butadiene. The NPAHs 1,4-dihydro(iso)quinoline and (iso)quinoline can be synthesized through reaction of pyridyl radicals with 1,3-butadiene or sequentially with two acetylene molecules, respectively. The inclusion of nitrogen into an aromatic system and their growth can fill the mechanistic gaps missing leading from acyclic nitrogen-bearing molecules via pyridine to NPAH-type molecules in the interstellar medium.

  2. Investigating Hydrocarbon Seep Environments with High-Resolution, Three-Dimensional Geographic Visualizations.

    Science.gov (United States)

    Doolittle, D. F.; Gharib, J. J.; Mitchell, G. A.

    2015-12-01

    Detailed photographic imagery and bathymetric maps of the seafloor acquired by deep submergence vehicles such as Autonomous Underwater Vehicles (AUV) and Remotely Operated Vehicles (ROV) are expanding how scientists and the public view and ultimately understand the seafloor and the processes that modify it. Several recently acquired optical and acoustic datasets, collected during ECOGIG (Ecosystem Impacts of Oil and Gas Inputs to the Gulf) and other Gulf of Mexico expeditions using the National Institute for Undersea Science Technology (NIUST) Eagle Ray, and Mola Mola AUVs, have been fused with lower resolution data to create unique three-dimensional geovisualizations. Included in these data are multi-scale and multi-resolution visualizations over hydrocarbon seeps and seep related features. Resolution of the data range from 10s of mm to 10s of m. When multi-resolution data is integrated into a single three-dimensional visual environment, new insights into seafloor and seep processes can be obtained from the intuitive nature of three-dimensional data exploration. We provide examples and demonstrate how integration of multibeam bathymetry, seafloor backscatter data, sub-bottom profiler data, textured photomosaics, and hull-mounted multibeam acoustic midwater imagery are made into a series a three-dimensional geovisualizations of actively seeping sites and associated chemosynthetic communities. From these combined and merged datasets, insights on seep community structure, morphology, ecology, fluid migration dynamics, and process geomorphology can be investigated from new spatial perspectives. Such datasets also promote valuable inter-comparisons of sensor resolution and performance.

  3. Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

    Science.gov (United States)

    Majcher, Emily H.; Phelan, Daniel J.; Lorah, Michelle M.; McGinty, Angela L.

    2007-01-01

    Wetlands act as natural transition zones between ground water and surface water, characterized by the complex interdependency of hydrology, chemical and physical properties, and biotic effects. Although field and laboratory demonstrations have shown efficient natural attenuation processes in the non-seep wetland areas and stream bottom sediments of West Branch Canal Creek, chlorinated volatile organic compounds are present in a freshwater tidal creek at Aberdeen Proving Ground, Maryland. Volatile organic compound concentrations in surface water indicate that in some areas of the wetland, preferential flow paths or seeps allow transport of organic compounds from the contaminated sand aquifer to the overlying surface water without undergoing natural attenuation. From 2002 through 2004, the U.S. Geological Survey, in cooperation with the Environmental Conservation and Restoration Division of the U.S. Army Garrison, Aberdeen Proving Ground, characterized preferential ground-water seepage as part of an ongoing investigation of contaminant distribution and natural attenuation processes in wetlands at this site. Seep areas were discrete and spatially consistent during thermal infrared surveys in 2002, 2003, and 2004 throughout West Branch Canal Creek wetlands. In these seep areas, temperature measurements in shallow pore water and sediment more closely resembled those in ground water than those in nearby surface water. Generally, pore water in seep areas contaminated with chlorinated volatile organic compounds had lower methane and greater volatile organic compound concentrations than pore water in non-seep wetland sediments. The volatile organic compounds detected in shallow pore water in seeps were spatially similar to the dominant volatile organic compounds in the underlying Canal Creek aquifer, with both parent and anaerobic daughter compounds detected. Seep locations characterized as focused seeps contained the highest concentrations of chlorinated parent compounds

  4. On the efficiency of the hybrid and the exact second-order sampling formulations of the EnKF: a reality-inspired 3-D test case for estimating biodegradation rates of chlorinated hydrocarbons at the port of Rotterdam

    KAUST Repository

    El Gharamti, Mohamad

    2016-11-15

    This study considers the assimilation problem of subsurface contaminants at the port of Rotterdam in the Netherlands. It involves the estimation of solute concentrations and biodegradation rates of four different chlorinated solvents. We focus on assessing the efficiency of an adaptive hybrid ensemble Kalman filter and optimal interpolation (EnKF-OI) and the exact second-order sampling formulation (EnKFESOS) for mitigating the undersampling of the estimation and observation errors covariances, respectively. A multi-dimensional and multi-species reactive transport model is coupled to simulate the migration of contaminants within a Pleistocene aquifer layer located around 25 m below mean sea level. The biodegradation chain of chlorinated hydrocarbons starting from tetrachloroethene and ending with vinyl chloride is modeled under anaerobic environmental conditions for 5 decades. Yearly pseudo-concentration data are used to condition the forecast concentration and degradation rates in the presence of model and observational errors. Assimilation results demonstrate the robustness of the hybrid EnKF-OI, for accurately calibrating the uncertain biodegradation rates. When implemented serially, the adaptive hybrid EnKF-OI scheme efficiently adjusts the weights of the involved covariances for each individual measurement. The EnKFESOS is shown to maintain the parameter ensemble spread much better leading to more robust estimates of the states and parameters. On average, a well tuned hybrid EnKF-OI and the EnKFESOS respectively suggest around 48 and 21 % improved concentration estimates, as well as around 70 and 23 % improved anaerobic degradation rates, over the standard EnKF. Incorporating large uncertainties in the flow model degrades the accuracy of the estimates of all schemes. Given that the performance of the hybrid EnKF-OI depends on the quality of the background statistics, satisfactory results were obtained only when the uncertainty imposed on the background

  5. On the efficiency of the hybrid and the exact second-order sampling formulations of the EnKF: a reality-inspired 3-D test case for estimating biodegradation rates of chlorinated hydrocarbons at the port of Rotterdam

    Directory of Open Access Journals (Sweden)

    M. E. Gharamti

    2016-11-01

    Full Text Available This study considers the assimilation problem of subsurface contaminants at the port of Rotterdam in the Netherlands. It involves the estimation of solute concentrations and biodegradation rates of four different chlorinated solvents. We focus on assessing the efficiency of an adaptive hybrid ensemble Kalman filter and optimal interpolation (EnKF-OI and the exact second-order sampling formulation (EnKFESOS for mitigating the undersampling of the estimation and observation errors covariances, respectively. A multi-dimensional and multi-species reactive transport model is coupled to simulate the migration of contaminants within a Pleistocene aquifer layer located around 25 m below mean sea level. The biodegradation chain of chlorinated hydrocarbons starting from tetrachloroethene and ending with vinyl chloride is modeled under anaerobic environmental conditions for 5 decades. Yearly pseudo-concentration data are used to condition the forecast concentration and degradation rates in the presence of model and observational errors. Assimilation results demonstrate the robustness of the hybrid EnKF-OI, for accurately calibrating the uncertain biodegradation rates. When implemented serially, the adaptive hybrid EnKF-OI scheme efficiently adjusts the weights of the involved covariances for each individual measurement. The EnKFESOS is shown to maintain the parameter ensemble spread much better leading to more robust estimates of the states and parameters. On average, a well tuned hybrid EnKF-OI and the EnKFESOS respectively suggest around 48 and 21 % improved concentration estimates, as well as around 70 and 23 % improved anaerobic degradation rates, over the standard EnKF. Incorporating large uncertainties in the flow model degrades the accuracy of the estimates of all schemes. Given that the performance of the hybrid EnKF-OI depends on the quality of the background statistics, satisfactory results were obtained only when the uncertainty imposed on

  6. Chlorinated paraffins in the environment: A review on their production, fate, levels and trends between 2010 and 2015

    NARCIS (Netherlands)

    van Mourik, L.M.; Gaus, P.; Leonards, P.E.G.; de Boer, J.

    2016-01-01

    This review provides an update on information regarding the production volumes, regulations, as well as the environmental levels, trends, fate and human exposure to chlorinated paraffin mixtures (CPs). CPs encompas thousands congeners with varying properties and environmental fate. Based on their

  7. Geochemical interpretation of distribution of aromatic hydrocarbons in components of geologic environment of Pechora, Barents and Kara seas.

    Science.gov (United States)

    Kursheva, Anna; Petrova, Vera; Litvinenko, Ivan; Morgunova, Inna

    2017-04-01

    Information about the hydrocarbons content (including aromatic ones) in components of geologic environment allows to define common factors in distribution and correlation both nature and technogenic component, and also to reveal the sources of contamination. At that, it should be noted, that hydrocarbons are widely spread in lithosphere and create steady geochemical background, variations are caused here by specifics of initial organic matter, conditions of its accumulation and transformation. The basis of the study are the samples of sea water and deep sea sediments (more than 600 stations), collected in western sector of Arctic region (Pechora, Barents and Kara seas) during the scientific-research expeditions of FSBI "VNIIOkeangeologia" for the period 2000-2010. Total content of aromatic hydrocarbons was defined by spectrofluorometric method using analyzer «FLUORAT-Panorama-02». Certification of data was performed on representative samples based on contents and molecule structure of polycyclic aromatic hydrocarbons using GC-MS (Agilent 5973/6850 GC-MS System). Results of spectrofluorometric analysis of lipid fraction of organic matter of bottom sediments allowed to define specific parameters, which characterize various lithofacies groups of sediments. Thus, sandy residues are characterized by low level of aromatic hydrocarbons (ca. 4.3 μg/g) with prevalence of bi- and tri-aromatic compounds (λmax 270-310 nm). This correlates with low sorption capacity of coarse-grained sediments and absence of organic-mineral component, containing the breakdown products of initial organic matter. Tetra- and penta- aromatic structures prevail in clay sediments (ca. 13.0 μg/g), which are typical components of lipid fraction of organic matter of post sedimentation and early diagenetic stages of transformation. At that, changes of spectral characteristic of sediments in stratigraphic sequence completely reflect processes of diagenetic transformation of organic matter, including

  8. PHOTOOXIDATION OF HYDROCARBONS TO PARTIAL OXYGENATES IN AN AQUEOUS ENVIRONMENT [EXHIBIT, POSTER

    Science.gov (United States)

    The USEPA is researching the use of alternative oxidation technologies (AOT's) as a catalytic process for the selective oxidation of hydrocarbon substrates. One AOT currently under investigation is the use of photocatalysis employed with a laminar thin-film falling reactor. Thi...

  9. Candidates for the development of consortia capable of petroleum hydrocarbon degradation in marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    David, J.; Gupta, R.; Mohandass, C.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    Bacteria and yeasts from different niches of the tropical Indian waters were screened for their hydrocarbon degrading potential using 1% w/v in artificial seawater over a period of 6 days. About 20% of the 75 bacterial and 24% of the 27 yeast...

  10. ATR-FTIR sensor development for continuous on-line monitoring of chlorinated aliphatic hydrocarbons in a fixed-bed bioreactor.

    Science.gov (United States)

    Acha, V; Meurens, M; Naveau, H; Agathos, S N

    2000-06-05

    This article describes the continuous on-line monitoring of a dechlorination process by a novel attenuated total reflection-Fourier transform infrared (ATR-FTIR) sensor. This optical sensor was developed to measure noninvasively part-per-million (ppm) concentrations of trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride (CT) in the aqueous effluent of a fixed-bed dechlorinating bioreactor, without any prior sample preparation. The sensor was based on an ATR internal reflection element (IRE) coated with an extracting hydrophobic polymer, which prevented water molecules from interacting with the infrared (IR) radiation. The selective diffusion of chlorinated compound molecules from aqueous solution into the polymer made possible their detection by the IR beam. With the exclusion of water the detection limits were lowered, and measurements in the low ppm level became possible. The best extracting polymer was polyisobutylene (PIB) in the form of a 5.8-microm thick film, which afforded a detection limit of 2, 3, and 2. 5 mg/L (ppm) for TCE, PCE, and CT, respectively. Values of the enrichment factors between the polymer coating and the water matrix of these chloro-organics were determined experimentally and were compared individually with predictions obtained from the slopes of absorbance/concentration curves for the three analytes. Before coupling the ATR-FTIR sensor to the dechlorinating bioreactor, preliminary spectra of the chlorinated compounds were acquired on a laboratory scale configuration in stop-flow and flow-through closed-loop modes. In this way, it was possible to study the behavior and direct response of the optical sensor to any arbitrary concentration change of the analytes. Subsequently, the bioreactor was monitored with the infrared sensor coupled permanently to it. The sensor tracked the progression of the analytes' spectra over time without perturbing the dechlorinating process. To calibrate the ATR-FTIR sensor, a total of 13

  11. Chlorinated, brominated, and perfluorinated compounds, polycyclic aromatic hydrocarbons and trace elements in livers of sea otters from California, Washington, and Alaska (USA), and Kamchatka (Russia).

    Science.gov (United States)

    Kannan, Kurunthachalam; Moon, Hyo-Bang; Yun, Se Hun; Agusa, Tetsuro; Thomas, Nancy J; Tanabe, Shinsuke

    2008-04-01

    Concentrations of organochlorine pesticides (DDTs, HCHs, and chlordanes), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds (PFCs), and 20 trace elements were determined in livers of 3- to 5-year old stranded sea otters collected from the coastal waters of California, Washington, and Alaska (USA) and from Kamchatka (Russia). Concentrations of organochlorine pesticides, PCBs, and PBDEs were high in sea otters collected from the California coast. Concentrations of DDTs were 10-fold higher in California sea otters than in otters from other locations; PCB concentrations were 5-fold higher, and PBDE concentrations were 2-fold higher, in California sea otters than in otters from other locations. Concentrations of PAHs were higher in sea otters from Prince William Sound than in sea otters from other locations. Concentrations of several trace elements were elevated in sea otters collected from California and Prince William Sound. Elevated concentrations of Mn and Zn in sea otters from California and Prince William Sound were indicative of oxidative stress-related injuries in these two populations. Concentrations of all of the target compounds, including trace elements, that were analyzed in sea otters from Kamchatka were lower than those found from the US coastal locations.

  12. Microbial and molecular techniques to evaluate and to implement in-situ biodegradation potential and activity at sites contaminated with aromatic and chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Karg, F. [HPC Envirotec / France and HPC AG (Germany); Henkler, Ch. [Planreal (Switzerland)

    2005-07-01

    (Biochemical Laboratory of the Medical Faculty) the first PBG-SP : 'Pole Biotechnologique et Genetique - Sites Pollues' in France. The modern tools and approaches have been applied successfully at several field sites for the evaluation, implementation and on-going monitoring of the bio-restoration/ attenuation of various aromatic and chlorinated compounds. (authors)

  13. Chlorinated hydrocarbon concentrations in plasma of the Lake Erie water snake (Nerodia sipedon insularum) and northern water snake (Nerodia sipedon sipedon) from the Great Lakes basin in 1998.

    Science.gov (United States)

    Bishop, C A; Rouse, J D

    2000-11-01

    From the Great Lakes basin, concentrations of 59 congener-specific polychlorinated biphenyls (PCBs) and 14 organochlorine pesticides were measured in blood plasma of northern water snake (Nerodia sipedon sipedon) and Lake Erie water snake (Nerodia sipedon insularum), which is endangered in Canada. In 1998, four male adult Lake Erie water snakes were sampled from Pelee Island, western Lake Erie; four male northern water snakes were sampled at Little Lake, about 20 km north of Parry Sound in central Ontario; and four adult gravid female northern water snakes were sampled from Garden Island, eastern Lake Ontario. The blood plasma was pooled by site for a total of three samples analyzed. The Pelee Island sample from male Lake Erie water snakes contained less than half the lipid concentration (0.349%) than samples from the other sites, but it was the most contaminated with PCBs, even on a wet weight basis. Summed concentration of individual PCBs in the Pelee Island sample was 167 ng/g (wet weight), which was 14-fold higher than the next most contaminated sample, which was from Little Lake. The plasma sample from Little Lake contained 12 ng/g (WW) and was four times more contaminated with PCBs than the sample from female snakes from Garden Island, Lake Ontario. Organochlorine pesticide concentrations in plasma were relatively similar among sites. None of the pesticides was found above trace concentrations (0.1-0.9 ng/g) except pp'-DDE, which occurred at 2-5 ng/g among sites. PCB congener patterns in the Lake Erie water snakes were compared to PCB patterns in plasma of common snapping turtle (Chelydra serpentina serpentina) from Lake Ontario, herring gull eggs (Larus argentatus) from western Lake Erie, and mudpuppy eggs (Necturus maculosus) from the Detroit River. The PCB patterns in water snake and herring gull sample were most similar, followed by the pattern in snapping turtle plasma. The presence of more lower-chlorinated chlorobiphenyls in the mudpuppy eggs relative

  14. Enhanced Attenuation of Unsaturated Chlorinated Solvent Source Zones using Direct Hydrogen Delivery

    Science.gov (United States)

    2013-01-01

    Heffner, 1988. Process for in situ biodegradation of hydrocarbon contaminated soil . United States Patent Office, Patent Number 4,765,902, August 28...solvents. This approach for bioremediation of unsaturated soils containing chlorinated solvents was originally proposed in a patent by Hughes et al...requires some type of treatment of chlorinated solvents. This approach for bioremediation of unsaturated soils containing chlorinated solvents was

  15. Depositional environment, organic matter characterization and hydrocarbon potential of Middle Miocene sediments from northeastern Bulgaria (Varna-Balchik Depression

    Directory of Open Access Journals (Sweden)

    Zdravkov Alexander

    2015-10-01

    Full Text Available The depositional environments and hydrocarbon potential of the siliciclastic, clayey and carbonate sediments from the Middle Miocene succession in the Varna-Balchik Depression, located in the south-eastern parts of the Moesian Platform, were studied using core and outcrop samples. Based on the lithology and resistivity log the succession is subdivided from base to top into five units. Siliciclastic sedimentation prevailed in the lower parts of units I and II, whereas their upper parts are dominated by carbonate rocks. Unit III is represented by laminated clays and biodetritic limestone. Units IV and V are represented by aragonitic sediments and biomicritic limestones, correlated with the Upper Miocene Topola and Karvuna Formations, respectively. Biogenic silica in the form of diatom frustules and sponge spicules correlates subunit IIa and unit III to the lower and upper parts of the Middle Miocene Euxinograd Formation. Both (subunits contain organic carbon contents in the order of 1 to 2 wt. % (median: 0.8 for subunit IIa; 1.3 for unit III, locally up to 4 wt. %. Based on Hydrogen Index values (HI and alkane distribution pattern, the kerogen is mainly type II in subunit IIa (average HI= 324 mg HC/g TOC and type III in unit III (average HI ~200 mg HC/g TOC. TOC and Rock Eval data show that subunit IIa holds a fair (to good hydrocarbon generative potential for oil, whereas the upper 5 m of unit III holds a good (to fair potential with the possibility to generate gas and minor oil. The rocks of both units are immature in the study area. Generally low sulphur contents are probably due to deposition in environments with reduced salinity. Normal marine conditions are suggested for unit III. Biomarker composition is typical for mixed marine and terrestrial organic matter and suggests deposition in dysoxic to anoxic environments.

  16. The bacterial community structure of hydrocarbon-polluted marine environments as the basis for the definition of an ecological index of hydrocarbon exposure.

    Science.gov (United States)

    Lozada, Mariana; Marcos, Magalí S; Commendatore, Marta G; Gil, Mónica N; Dionisi, Hebe M

    2014-09-17

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

  17. Chlorine Clues

    Science.gov (United States)

    2004-01-01

    This plot shows that levels of the element chlorine rise dramatically in the deeper rocks lining the walls of the crater dubbed 'Endurance.' The data shown here were taken by the Mars Exploration Rover Opportunity's alpha particle X-ray spectrometer at Endurance and 'Eagle Crater,' the site where Opportunity first landed at Meridiani Planum. Opportunity has been inching down the walls of Endurance Crater, investigating distinct layers of rock as it goes for clues to Mars' buried past. The various Endurance layers have been informally labeled 'A' through 'F.' Targets within these layers are listed on the graph along with previous targets from Eagle Crater. All the rocks listed here were observed after they had been drilled by the rover's rock abrasion tool. The observations indicate that the elements making up the shallow rock layers of Endurance Crater resemble those of Eagle, while the deeper layers of Endurance possess increasingly higher concentrations of the element chlorine. Opportunity will continue to roll deeper into Endurance to see if this puzzling trend continues. Scientists hope the new data will help them figure out how the presence of chlorine fits into the history of water at Endurance Crater.

  18. Products of methotrexate during chlorination.

    Science.gov (United States)

    Yin, Jie; Niu, Yumin; Shao, Bing

    2017-05-01

    Methotrexate (MTX) is a cytotoxic drug widely used in the treatment of tumors, autoimmune diseases and severe asthma. jen00883This drug has been frequently detected in the aquatic environment with concentrations up to μg/L levels. The MTX present in environmental water might be transformed and removed during chlorination disinfection treatment. In this work, the fate of MTX during aqueous chlorination was investigated in laboratory batch experiments, and the transformation products of MTX were identified. Aqueous solutions of MTX (1mg/L) were chlorinated by sodium hypochlorite solution at room temperature under neutral pH conditions. Chlorinated products were pre-concentrated with solid-phase extraction (SPE) cartridges and determined by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The reaction of MTX chlorination exhibited pseudo-first-order kinetics and the half-life time of MTX degradation was calculated to be 1.65min, when the initial chlorine concentration was 2mg/L. Two chlorinated MTX congeners, 4-amino-3-chlorinated-N10-methylpteroylglutamic (monochloro-MTX) and 4-amino-3,5-dichloro-N10-methylpteroylglutamic (dichloro-MTX) were found in the chlorinated solution. Monochloro-MTX was successfully fractionated by high performance liquid chromatography (HPLC) and its structure was further identified using 1H nuclear magnetic resonance (NMR) analysis. The presence of the two products in real hospital wastewater was then examined and both compounds were detected. Finally, the effects of MTX and monochloro-MTX on the cell cycle progression in vitro were evaluated using zebrafish liver cell line. It was found that both compounds could inhibit the proliferation of zebrafish liver cells through S phase arrest and their effects on the cell cycle profile had no significant difference. Copyright © 2016. Published by Elsevier B.V.

  19. The hydrogen concentration as parameter to identify natural attenuation processes of volatile chlorinated hydrocarbons in ground water; Die Wasserstoffkonzentration als Parameter zur Identifizierung des natuerlichen Abbaus von leichtfluechtigen Chlorkohlenwasserstoffen (LCKW) im Grundwasser

    Energy Technology Data Exchange (ETDEWEB)

    Alter, M.D.

    2006-06-15

    In this study, the hydrogen concentration as parameter to identify natural attenuation processes of volatile chlorinated hydrocarbons was investigated. The currently accepted and recommended bubble strip method for hydrogen sampling was optimized, and a storage method for hydrogen samples was developed. Furthermore batch experiments with a dechlorinating mixed culture and pure cultures were carried out to study H{sub 2}-concentrations of competing redox processes. The extraction of hydrogen from ground water was optimized by a reduced inlet diameter of the usually applied gas sampling bulbs, allowing a maximal turbulent ow and gas transfer. With a gas volume of 10 ml and flow rates of 50 to 140 ml/min, the course of extraction almost followed the theoretical course of equilibration. At flow rates > 100 ml/min a equilibrium of 98% was achieved within 20 min. Until recently it was generally accepted that hydrogen samples can be stored only for 2 hours and therefore have to be analyzed immediately in the eld. Here, it was shown that eld samples can be stored for 1-3 days until analysis. For the dechlorination of tetrachloroethene (PCE), a hydrogen threshold concentration of 1-2 nM was found with the dechlorinating mixed culture as well as with a pure culture of Sulfurospirillum multivorans in combination with another pure culture Methanosarcina mazei. No dechlorination was detectable below this concentration. With the dechlorinating mixed culture, this finding is valid for all successive dechlorination steps until ethene. The hydrogen threshold concentration for denitrification were below the detection limit of 0,2 nM with the dechlorinating mixed culture. A threshold concentration of 3,1-3,5 nM was found for sulphate reduction and a threshold of 7-9 nM H{sub 2} for hydrogenotrophic methanogenesis. This implies that the natural dechlorination at contaminated sites is preferred to competing processes like sulphate reduction and methanogenesis. The threshold

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

    Science.gov (United States)

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

    2005-01-01

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

  1. POLYCYCLIC AROMATIC HYDROCARBONS CONCENTRATION AND MUTAGENIC EFFECTS OF DUST IN OUTDOOR ENVIRONMENT IN SILESIAN REGION

    Directory of Open Access Journals (Sweden)

    Agnieszka Kozłowska

    2011-09-01

    Full Text Available Quality and quantity of pollution depend on the combusted fuels and industrial technologies, the season of the year and meteorological conditions. Dust pollution of the air consists of diverse chemical organic and inorganic substances. Polycyclic aromatic hydrocarbon (PAH mixture and their nitric, amin, oxidated and chlorated derivatives, which are found in all dust fractions, are particularly dangerous to human health and exert mutagenic effects. PAHs are measured and analyzed using liquid chromatography, which is one of the most popular technique in analytical chemistry. Standard Ames test on Salmonella strain TA98 and YG1041 was used to assess mutagenic properties of dust. Samples of dust were collected on glass fiber filters by aspiration instrument with air flow 1 m3/min. during the autumn in six cities in Silesian Region. Extraction of pollution was carried out in Soxhlet instrument using dichlorometane in the ventilated chamber. There was majority of indirect mutagenic substances (requiring metabolic activation in studied samples. Mutagenic activity of dust fractions in outdoor air was caused by the PAHs concentrations, and particularly by benzo(apyrene, what was confirmed by HPLC.

  2. Genotype-by-environment interactions for female mate choice of male cuticular hydrocarbons in Drosophila simulans.

    Directory of Open Access Journals (Sweden)

    Fiona C Ingleby

    Full Text Available Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection.

  3. Genotype-by-Environment Interactions for Female Mate Choice of Male Cuticular Hydrocarbons in Drosophila simulans

    Science.gov (United States)

    Ingleby, Fiona C.; Hunt, John; Hosken, David J.

    2013-01-01

    Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E) variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection. PMID:23825675

  4. Sorption of polycyclic aromatic hydrocarbons and polychlorinated biphenyls to soot and soot-like materials in the aqueous environment: Mechanistic considerations

    NARCIS (Netherlands)

    Jonker, M.T.O.; Koelmans, A.A.

    2002-01-01

    Recent studies have shown that sorption of polycyclic aromatic hydrocarbons (PAHs) in soot-water systems is exceptionally strong. As a consequence, soot may fully control the actual fate of PAHs in the aquatic environment. However, sorption has only been characterized for a limited number of PAHs to

  5. Chlorinated volatile organic compounds (Cl-VOCs) in environment - sources, potential human health impacts, and current remediation technologies.

    Science.gov (United States)

    Huang, Binbin; Lei, Chao; Wei, Chaohai; Zeng, Guangming

    2014-10-01

    Chlorinated volatile organic compounds (Cl-VOCs), including polychloromethanes, polychloroethanes and polychloroethylenes, are widely used as solvents, degreasing agents and a variety of commercial products. These compounds belong to a group of ubiquitous contaminants that can be found in contaminated soil, air and any kind of fluvial mediums such as groundwater, rivers and lakes. This review presents a summary of the research concerning the production levels and sources of Cl-VOCs, their potential impacts on human health as well as state-of-the-art remediation technologies. Important sources of Cl-VOCs principally include the emissions from industrial processes, the consumption of Cl-VOC-containing products, the disinfection process, as well as improper storage and disposal methods. Human exposure to Cl-VOCs can occur through different routes, including ingestion, inhalation and dermal contact. The toxicological impacts of these compounds have been carefully assessed, and the results demonstrate the potential associations of cancer incidence with exposure to Cl-VOCs. Most Cl-VOCs thus have been listed as priority pollutants by the Ministry of Environmental Protection (MEP) of China, Environmental Protection Agency of the U.S. (U.S. EPA) and European Commission (EC), and are under close monitor and strict control. Yet, more efforts will be put into the epidemiological studies for the risk of human exposure to Cl-VOCs and the exposure level measurements in contaminated sites in the future. State-of-the-art remediation technologies for Cl-VOCs employ non-destructive methods and destructive methods (e.g. thermal incineration, phytoremediation, biodegradation, advanced oxidation processes (AOPs) and reductive dechlorination), whose advantages, drawbacks and future developments are thoroughly discussed in the later sections. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Thermodynamyc modeling of hydrogenation reactions of aromatic hydrocarbons in various environments

    Directory of Open Access Journals (Sweden)

    A. Gyulmaliev

    2013-09-01

    Full Text Available The hydrogenation of aromatic structures in different environments (molecular hydrogen, H2S, NH3 (NH4OH, CO + H2O, methane + water steam with the active hydrogen formation were investigated by methods of chemical thermodynamics for model compounds of benzene and naphthalene.

  7. On chlorinated hydrocarbons in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    The data available on the distribution of organochlorine compounds such as DDT and its metabolites, aldrin, dieldrin, endrin, isomers of HCH and the PCBs in the sediments, water, zooplankton, fish and seals from the Indian Ocean is reviewed. High...

  8. Community Structure in Methanogenic Enrichments Provides Insight into Syntrophic Interactions in Hydrocarbon-Impacted Environments

    DEFF Research Database (Denmark)

    Fowler, Jane; Toth, Courtney R. A.; Gieg, Lisa M.

    2016-01-01

    -impacted environments. In this study, a methanogenic crude oil-degrading enrichment culture was successively transferred onto the single long chain fatty acids palmitate or stearate followed by their parent alkanes, hexadecane or octadecane, respectively, in order to assess the impact of different substrates......, indicate that many syntrophic interactions are stable over time despite changes in substrate pressure, and show that syntrophic interactions amongst bacteria themselves are as important as interactions between bacteria and methanogens in complex methanogenic communities....

  9. Polycyclic aromatic hydrocarbons (PAHs) enrich their degrading genera and genes in human-impacted aquatic environments.

    Science.gov (United States)

    Yuan, Ke; Chen, Baowei; Qing, Qing; Zou, Shichun; Wang, Xiaowei; Luan, Tiangang

    2017-11-01

    Bacterial degradation is an important clearance pathway for organic contaminants from highly human-impacted environments. However, it is not fully understood how organic contaminants are selected for degradation by bacteria and genes in aquatic environments. In this study, PAH degrading bacterial genera and PAH-degradation-related genes (PAHDGs) in sediments collected from the Pearl River (PR), the Pearl River Estuary (PRE) and the South China Sea (SCS), among which there were distinct differences in anthropogenic impact, were analyzed using metagenomic approaches. The diversity and abundance of PAH degrading genera and PAHDGs in the PR were substantially higher than those in the PRE and the SCS and were significantly correlated with the total PAH concentration. PAHDGs involved with the three key processes of PAH degradation (ring cleavage, side chain and central aromatic processes) were significantly correlated with each other in the sediments. In particular, plasmid-related PAHDGs were abundant in the PR sediments, indicating plasmid-mediated horizontal transfer of these genes between bacteria or the overgrowth of the bacteria containing these plasmids under the stresses of PAHs. Our results suggest that PAH degrading bacteria and genes were rich in PAH-polluted aquatic environments, which could facilitate the removal of PAHs by bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Gene-environment interactions in male reproductive health: special reference to the aryl hydrocarbon receptor signaling pathway

    Directory of Open Access Journals (Sweden)

    Leon J S Brokken

    2014-02-01

    Full Text Available Over the last few decades, there have been numerous reports of adverse effects on the reproductive health of wildlife and laboratory animals caused by exposure to endocrine disrupting chemicals (EDCs. The increasing trends in human male reproductive disorders and the mounting evidence for causative environmental factors have therefore sparked growing interest in the health threat posed to humans by EDCs, which are substances in our food, environment and consumer items that interfere with hormone action, biosynthesis or metabolism, resulting in disrupted tissue homeostasis or reproductive function. The mechanisms of EDCs involve a wide array of actions and pathways. Examples include the estrogenic, androgenic, thyroid and retinoid pathways, in which the EDCs may act directly as agonists or antagonists, or indirectly via other nuclear receptors. Dioxins and dioxin-like EDCs exert their biological and toxicological actions through activation of the aryl hydrocarbon-receptor, which besides inducing transcription of detoxifying enzymes also regulates transcriptional activity of other nuclear receptors. There is increasing evidence that genetic predispositions may modify the susceptibility to adverse effects of toxic chemicals. In this review, potential consequences of hereditary predisposition and EDCs are discussed, with a special focus on the currently available publications on interactions between dioxin and androgen signaling.

  11. Microbial degradation of petroleum hydrocarbons.

    Science.gov (United States)

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Longterm performance of polyolefins in different environments including chlorinated water: antioxidant consumption and migration and polymer degradation

    OpenAIRE

    Lundbäck, Marie

    2005-01-01

    The long-term performance of stabilized polyolefins in different environments was studied with focus on antioxidant consumption and migration. Plaques of linear polyethylene (LPE) and branched polyethylene (BPE) were stabilized with Santonox® R (4,4'-Thiobis(6-tert-butyl-3-methylphenol)), Irganox® 1081 (2,2’-Thiobis(4-methyl-6-tertbutylphenol)), or Lowinox® 22M46 (2,2’-Methylenebis(6-tert-butyl-4-methylphenol)). The samples were aged in water and nitrogen at 75, 90 and 95°C. Antioxidant conce...

  13. Comparative analysis of concentrations of lead, cadmium and mercury in cord blood, maternal blood, and breast milk, as well as persistent chlorinated hydrocarbons in maternal milk samples from Germany and Iran; Vergleichende Untersuchungen ueber die Blei-, Cadmium- und Quecksilberkonzentrationen im Nabelschnurblut, im muetterlichen Blut und in der Frauenmilch sowie ueber einige persistente Organochlorverbindungen in der Milch deutscher und iranischer Muetter

    Energy Technology Data Exchange (ETDEWEB)

    Javanmardi, F.

    2001-07-01

    The concentration of the heavy metals lead, cadmium and mercury in cord blood, maternal blood and breast milk has been studied. Lead and cadmium were analyzed by atomic absorption spectrometry. Mercury was determined using the flow-injection hydride technique. According to the concentrations of heavy metals and chlorinated hydrocarbons we ascertained for the region of Rendsburg, the toxic risk for infants relative to the consumption of contaminated maternal milk can be viewed as very slight. (orig.) [German] Ziel der Arbeit war es, die aktuelle Schwermetallbelastung des Nabelschnurblutes, des muetterlichen Blutes und der Muttermilch zu untersuchen. Die Bestimmung von Blei und Cadmium erfolgte mit Hilfe der Atomabsorptionsspektrometrie. Quecksilber wurde mittels der Fliessinjektions-Hydridtechnik bestimmt. Nach den von uns ermittelten Schwermetall- bzw. Chlorkohlenwasserstoffkonzentrationen fuer die Region Rendsburg kann das mit dem Verzehr kontaminierter Muttermilch verbundene toxische Risiko fuer den Saeugling als sehr gering eingeschaetzt werden. (orig.)

  14. The Chlorination Quandary

    Science.gov (United States)

    Josephson, Julian

    1978-01-01

    Current use of chlorination technology to disinfect water supplies can cause the production of undesirable products, among them chloroform and chlorobenzene. Alternatives to this methodology include the use of ozone, chlorine dioxide, and bromine chloride in place of chlorine. Presently, the methods are feasible in developed countries only. (MA)

  15. Development of a Raman spectroscopy technique to detect alternate transportation fuel hydrocarbon intermediates in complex combustion environments.

    Energy Technology Data Exchange (ETDEWEB)

    Ekoto, Isaac W.; Barlow, Robert S.

    2012-12-01

    Spontaneous Raman spectra for important hydrocarbon fuels and combustion intermediates were recorded over a range of low-to-moderate flame temperatures using the multiscalar measurement facility located at Sandia/CA. Recorded spectra were extrapolated to higher flame temperatures and then converted into empirical spectral libraries that can readily be incorporated into existing post-processing analysis models that account for crosstalk from overlapping hydrocarbon channel signal. Performance testing of the developed libraries and reduction methods was conducted through an examination of results from well-characterized laminar reference flames, and was found to provide good agreement. The diagnostic development allows for temporally and spatially resolved flame measurements of speciated hydrocarbon concentrations whose parent is more chemically complex than methane. Such data are needed to validate increasingly complex flame simulations.

  16. Multi-element isotope fractionation concepts to characterize the biodegradation of hydrocarbons - from enzymes to the environment.

    Science.gov (United States)

    Vogt, Carsten; Dorer, Conrad; Musat, Florin; Richnow, Hans-Hermann

    2016-10-01

    Multi-element compound-specific isotope fractionation (ME-CSIA) has become a state-of-the-art approach for identifying biotransformation reactions. In the last decade, several studies focused on the combined analysis of carbon and hydrogen stable isotopes upon biodegradation of hydrocarbons due to its widespread environmental occurrence as contaminants, often in high concentrations. Most known initial transformation reactions of hydrocarbons have been isotopically characterized in laboratory experiments using model cultures. The data suggest that several of these reactions - especially those occurring under anoxic conditions - can be identified by ME-CSIA, although a number of constraints have been realized which may lead to wrong ME-CSIA data interpretations in field studies. Generally, the applicability of ME-CSIA regarding hydrocarbon biodegradation needs to be corroborated in future field studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Short- and medium-chain chlorinated paraffins in air and soil of subtropical terrestrial environment in the pearl river delta, South China: distribution, composition, atmospheric deposition fluxes, and environmental fate.

    Science.gov (United States)

    Wang, Yan; Li, Jun; Cheng, Zhineng; Li, Qilu; Pan, Xiaohui; Zhang, Ruijie; Liu, Di; Luo, Chunling; Liu, Xiang; Katsoyiannis, Athanasios; Zhang, Gan

    2013-03-19

    Research on the environmental fate of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in highly industrialized subtropical areas is still scarce. Air, soil, and atmospheric deposition process in the Pearl River Delta of South China were investigated, and the average SCCP and MCCP concentrations were 5.2 μg/sampler (17.69 ng/m(3)) and 4.1 μg/sampler for passive air samples, 18.3 and 59.3 ng/g for soil samples, and 5.0 and 5.3 μg/(m(2)d) for deposition samples, respectively. Influenced by primary sources and the properties of chlorinated paraffins (CPs), a gradient trend of concentrations and a fractionation of composition from more to less industrialized areas were discovered. Intense seasonal variations with high levels in summer air and winter deposition samples indicated that the air and deposition CP levels were controlled mainly by the vapor and particle phase, respectively. Complex environmental processes like volatilization and fractionation resulted in different CP profiles in different environment matrixes and sampling locations, with C(10-11) C(l6-7) and C(14) C(l6-7), C(10-12) C(l6-7) and C(14) C(l6-8), and C(11-12) C(l6-8) and C(14) C(l7-8) dominating in air, soil, and atmospheric deposition, respectively. Shorter-chain and less chlorinated congeners were enriched in air in the less industrialized areas, while longer-chain and higher chlorinated congeners were concentrated in soil in the more industrialized areas. This is suggesting that the gaseous transport of CPs is the dominant mechanism responsible for the higher concentrations of lighter and likely more mobile CPs in the rural areas.

  18. Sedimentary hydrocarbons and sterols in a South Atlantic estuarine/shallow continental shelf transitional environment under oil terminal and grain port influences.

    Science.gov (United States)

    Bet, Rafael; Bícego, Marcia C; Martins, César C

    2015-06-15

    Sterols and hydrocarbons were determined in the surface sediments from the transitional environment between Paranaguá Bay and the shallow continental shelf in the South Atlantic to assess the sources of organic matter (OM) and the contamination status of an area exposed to multiple anthropogenic inputs. Total aliphatic hydrocarbon concentrations were less than 10μgg(-1), which is typical of unpolluted sediments, and related to recent inputs from higher terrestrial plants. Total polycyclic aromatic hydrocarbon ranged from

  19. Hydrocarbon degraders establish at the costs of microbial richness, abundance and keystone taxa after crude oil contamination in permafrost environments.

    Science.gov (United States)

    Yang, Sizhong; Wen, Xi; Shi, Yulan; Liebner, Susanne; Jin, Huijun; Perfumo, Amedea

    2016-11-25

    Oil spills from pipeline ruptures are a major source of terrestrial petroleum pollution in cold regions. However, our knowledge of the bacterial response to crude oil contamination in cold regions remains to be further expanded, especially in terms of community shifts and potential development of hydrocarbon degraders. In this study we investigated changes of microbial diversity, population size and keystone taxa in permafrost soils at four different sites along the China-Russia crude oil pipeline prior to and after perturbation with crude oil. We found that crude oil caused a decrease of cell numbers together with a reduction of the species richness and shifts in the dominant phylotypes, while bacterial community diversity was highly site-specific after exposure to crude oil, reflecting different environmental conditions. Keystone taxa that strongly co-occurred were found to form networks based on trophic interactions, that is co-metabolism regarding degradation of hydrocarbons (in contaminated samples) or syntrophic carbon cycling (in uncontaminated samples). With this study we demonstrate that after severe crude oil contamination a rapid establishment of endemic hydrocarbon degrading communities takes place under favorable temperature conditions. Therefore, both endemism and trophic correlations of bacterial degraders need to be considered in order to develop effective cleanup strategies.

  20. Chlorinated pesticide residues in sediments from the Arabian Sea along the Central West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    Environmental contamination by persistent chlorinated pesticides has evoked major concern due to the presence of their residues in the environment. The quantitative distribution of chlorinated pesticides residues in the marine sediments from...

  1. 40 CFR 52.1877 - Control strategy: Photochemical oxidants (hydrocarbons).

    Science.gov (United States)

    2010-07-01

    ... oxidants (hydrocarbons). 52.1877 Section 52.1877 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....1877 Control strategy: Photochemical oxidants (hydrocarbons). (a) The requirements of Subpart G of this... national standard for photochemical oxidants (hydrocarbons) in the Metropolitan Cincinnati interstate...

  2. Evaluating chlorine isotope effects from isotope ratios and mass spectra of polychlorinated molecules.

    Science.gov (United States)

    Elsner, Martin; Hunkeler, Daniel

    2008-06-15

    Compound-specific chlorine isotope analysis receives much interest to assess the fate of chlorinated hydrocarbons in contaminated environments. This paper provides a theoretical basis to calculate isotope ratios and quantify isotope fractionation from ion-current ratios of molecular- and fragment-ion multiplets. Because both (35)Cl and (37)Cl are of high abundance, polychlorinated hydrocarbons consist of molecules containing different numbers of (37)Cl denoted as isotopologues. We show that, during reactions, the changes in isotopologue ratios are proportional to changes in the isotope ratio assuming a nonselective isotope distribution in the initial compound. This proportionality extents even to fragments formed in the ion source of a mass spectrometer such as C 2Cl 2 (double dechlorinated fragment of perchloroethylene, PCE). Fractionation factors and kinetic isotope effects (KIE) may, therefore, be evaluated from isotope, isotopologue or even fragment ratios according to conventional simple equations. The proportionality is exact with symmetric molecules such as dichloroethylene (DCE) and PCE, whereas it is approximately true with molecules containing nonreactive positions such as trichloroethylene (TCE). If in the latter case isotope ratios are derived from dechlorinated fragments, e.g., C 2HCl 2, it is important that fragmentation in the ion source affect all molecular positions alike, as otherwise isotopic changes in reactive positions may be underrepresented.

  3. 40 CFR 90.316 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 90... Equipment Provisions § 90.316 Hydrocarbon analyzer calibration. (a) Calibrate the FID and HFID hydrocarbon... thereafter, adjust the FID and HFID hydrocarbon analyzer for optimum hydrocarbon response as specified in...

  4. 40 CFR 89.319 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 89... Equipment Provisions § 89.319 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon analyzer shall... and at least annually thereafter, adjust the FID hydrocarbon analyzer for optimum hydrocarbon response...

  5. Optimization of environment compatible analysis methods for mineral hydrocarbons in the soil; Optimierung umweltvertraeglicher Analysenverfahren fuer Mineraloelkohlenwasserstoffe im Boden

    Energy Technology Data Exchange (ETDEWEB)

    Flachowsky, J.; Borsdorf, H. [eds.] [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Leipzig (Germany); Loehmannsroeben, H.G.; Roch, T. [Erlangen-Nuernberg Univ., Erlangen (Germany); Leopom, P. [Umweltbundesamt, Berlin (Germany); Reimers, C. [Technische Univ. Hamburg-Harburg, Hamburg (Germany); Matz, G.; Kuebler, J. [MOBILAB GmbH, Hamburg (Germany); Christall, B. [SOFIA GmbH, Berlin (Germany); Hahn, M.; Matschiner, H. [Elektrochemie Halle GmbH (Germany); Baermann, A. [Dr. Baermann und Partner Mikroanalytik, Hamburg (Germany)

    1997-12-31

    This paper describes several analytical methods for the quantitative chemical analysis of mineral oil hydrocarbons in soils. The measuring methods are investigated on accuracy, errors, sample preparation methods, analysis of reference materials and real materials. (SR) [Deutsch] Mit dieser Schrift praesentiert die Deutsche Bundesstiftung Umwelt der Oeffentlichkeit Ergebnisse zu alternativen umweltvertraeglichen Bestimmungsmethoden fuer Mineraloelkohlenwasserstoffe in Boeden. Es war in erster Linie das Ziel aller beteiligten Forscher und Entwickler, die heute noch in der Anwendung befindliche Vorschrift nach DIN 38409 H18 zur Analytik von Mineraloelkohlenwasserstoffen durch eine sowohl umweltfreundliche als auch insgesamt aussagekraeftige Methode zu substituieren. (orig.)

  6. Water Treatment Technology - Chlorination.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on chlorination provides instructional materials for nine competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purpose and process of chlorination, chlorine…

  7. Tetramethylbenzidine method for monitoring the free available chlorine and microbicidal activity of chlorite-based sanitizers under organic-matter-rich environments.

    Science.gov (United States)

    Yamaoka, H; Nakayama-Imaohji, H; Horiuchi, I; Yamasaki, H; Nagao, T; Fujita, Y; Maeda, H; Goda, H; Kuwahara, T

    2016-01-01

    Chlorine is a principal disinfectant for food and environmental sanitation. Monitoring of free available chlorine (FAC) is essential for ensuring the efficacy of food disinfection processes that rely on chlorine. N,N-diethyl-p-phenylenediamine (DPD) is commonly used for FAC monitoring. However, here, we show that upon contact with bovine serum albumin (BSA) or broiler carcasses, chlorite (HClO2 )-based sanitizers acquire a pink colour, which can interfere with measurement of oxidized DPD absorbance at 513-550 nm. Alternatively, the pink colour did not interfere with 3,3',5,5'-tetramethylbenzidine (TMB)-based FAC monitoring. The FAC levels of NaClO and weakly acidified chlorous acid water (WACAW) were first adjusted by the TMB method and the killing activity of these sanitizers towards methicillin-resistant Staphylococcus aureus (MRSA) and feline calicivirus (FCV) was compared in the presence or absence of 0·5% BSA. At 200 ppm FAC, NaClO lost its bactericidal activity against MRSA after 10-min incubation with 0·5% BSA. Meanwhile, under the same conditions WACAW reduced the number of bacteria to below the detection limit. Similar results were obtained with FCV, indicating that the chlorite-based WACAW sanitizer is relatively stable under organic-matter-rich conditions. Moreover, TMB is suitable for in situ FAC monitoring of chlorite-based sanitizers in food and environmental disinfection processes. For practical applications of chlorine in food processing, monitoring of FAC is critical to validate disinfection efficacy. In this study we found that chlorite-based sanitizers acquired a pink colour upon contact with BSA or broiler carcasses. This pink colour interfered with FAC monitoring by methods that measure oxidized N,N-diethyl-p-phenylenediamine absorbance between 513-550 nm. Alternatively, FAC levels of chlorite-based sanitizers could be monitored using the absorbance of 3,3',5,5'-tetramethylbenzidine at 650 nm, which does not overlap with the acquired

  8. Imidazole catalyzes chlorination by unreactive primary chloramines.

    Science.gov (United States)

    Roemeling, Margo D; Williams, Jared; Beckman, Joseph S; Hurst, James K

    2015-05-01

    fluorescein chlorination by HOCl. Time-dependent imidazole-catalyzed HPA chlorination by NH2Cl was also demonstrated by product analyses. Quantitative assessment of the data suggests that physiological levels of histidyl groups will react with primary chloramines to generate a flux of imidazole chloramine sufficient to catalyze biological chlorination via HImCl(+), particularly in environments that generate high concentrations of HOCl such as the neutrophil phagosome. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Chlorine gas; exemptions from the... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance. Chlorine gas is exempted from the requirement of a tolerance when used preharvest or postharvest in solution on...

  10. The fate of petroleum hydrocarbons in the subsurface environment. Transportation and transformation mechanism; Il destino ambientale degli idrocarburi petroliferi nel sottosuolo. Meccanismi di trasporto e di trasformazione

    Energy Technology Data Exchange (ETDEWEB)

    Zerlia, T. [Stazione sperimentale per i combustibili, San Donato Milanese, MI (Italy)

    2000-11-01

    Understanding the fate of petroleum products in the soil systems is the starting point to evaluate and predict pollution migration and to design remedial actions. Several processes and chemical-physical parameters are involved. The key parameters influencing transport and transformation mechanisms of petroleum hydrocarbons in the subsurface environment are considered. [Italian] La comprensione del destino dei prodotti petroliferi nel suolo e nel sottosuolo e' premessa essenziale per valutare e per prevedere la diffusione e le conseguenze dell'inquinamento e per programmare le azioni di contenimento e di bonifica. Molteplici gli aspetti coinvolti. Vengono presi in esame i parametri chiave che influenzano i meccanismi di trasporto e di trasformazione degli idrocarburi petroliferi nel suolo.

  11. Reaction products of chlorine dioxide.

    OpenAIRE

    Stevens, A. A.

    1982-01-01

    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxi...

  12. Formation of isohexyl alkylaromatic hydrocarbons from aromatization-rearrangement of terpenoids in the sedimentary environment: A new class of biomarker

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.; Singh, R.K.; Alexander, R.; Kagi, R.I. [Curtin Univ. of Technology, Perth (Australia)

    1996-12-01

    Seven alkylaromatic hydrocarbons with an isohexyl and a methyl substituent group on adjacent ring carbons have been identified in a suite of crude oils derived from a range of locations, source types, palaeoenvironments, and ages. Hitherto unidentified series of isohexylalkylbenzenes and isohexylalkylnaphthalenes have been observed with concentrations ranging from 10 to 565 {mu}g/g. Isohexy1alkylbenzenes occur in crude oils ranging in age from Cambrian to Tertiary suggesting both a bacterial/ algal and higher plant origin, whereas isohexylalkylnaphthalenes were restricted to crude oils of Permian to Tertiary age and are exclusively associated with specific higher plant precursors. The unique structure of these compounds has been shown to result from rearrangement and A-ring opening of diterpenoid and triterpenoid natural products during aromatization. The structural features that are necessary for this process to occur are a terpenoid A-B ring system with a gem-dimethyl group at C-4 and an angular methyl at C-10. Support for a ring opening process concomitant with aromatization was provided by laboratory experiments involving dehydrogenation of terpenoid natural products. Analysis of these reaction products showed that isohexyl alkylaromatic compounds, along with fully aromatized compounds with intact carbon skeletons were formed. 57 refs., 14 figs., 4 tabs.

  13. Atmospheric reactivity of alcohols, thiols and fluoroalcohols with chlorine atoms

    Science.gov (United States)

    Garzon Ruiz, Andres

    Alcohols, thiols and fluoroalcohols are volatile organic compounds (VOCs) which are emitted to the atmosphere from both natural (vegetation, oceans, volcanoes, etc.) and anthropogenic sources (fuels, solvents, wastewater, incinerators, refrigerants, etc.). These pollutants can be eliminated from the troposphere by deposition on the terrestrial surface, direct photolysis or reaction with different tropospheric oxidants. Reactions of VOCs with tropospheric oxidants are involved in the well-known atmospheric phenomenon of photochemical smog or the production of tropospheric ozone. The oxidation of these VOCs in the troposphere is mainly initiated by reaction with OH radicals during the daytime and with NO radicals at night. However, in recent years, the oxidation by chlorine atoms (Cl) has gained great importance in the study of atmospheric reactions because they may exert some influence in the boundary layer, particularly in marine and coastal environments. In general, Cl atoms are much more reactive species than OH and NO; radicals and therefore low concentrations of Cl may compete with OH and NO3 in hydrocarbon oxidation processes. The main source of tropospheric Cl atoms is believed to be the photolysis of chlorine-containing molecules generated by heterogeneous reactions of sea salt aerosols. It has also been proposed that Cl atoms, produced in the photolysis of Cl2 emitted from industrial processes, may enhance hydrocarbon oxidation rates and ozone production in urban environments. In this work, a kinetic, theoretical and mechanistic study of the reaction of several alcohols, thiols, and fluoroalcohols with Cl atoms has been carried out. Pulsed laser photolysis-fluorescence resonance (PLP-RF) technique was used for the kinetic study as a function of temperature and pressure. An environmental chamber-Fourier transform infrared (FTIR) system was also employed in the kinetic studies. Tropospheric lifetimes of these pollutants were estimated using obtained kinetic

  14. Occurrence and growth potentials of hydrocarbon degrading ...

    African Journals Online (AJOL)

    ... the hydrocarbon occurred between the 8th and 14th day. It was therefore concluded that bacteria with ability to utilize hydrocarbons could be obtained from leaf surfaces. Such organisms could serve as seeds for bioaugmentation during remediation of polluted environments. Keywords: Phylloplane, bacteria, hydrocarbon, ...

  15. Chlorine dioxide as phenol and H2S scavenger - formation of halogenated phenols and subsequent environmental risk

    Energy Technology Data Exchange (ETDEWEB)

    Melbye, Alf G.; Faksness, Liv-Guri; Knudsen, Boerre Leif

    2006-03-15

    Formation of halogenated phenols as side products from treatment of produced water with aqueous chlorine dioxide has been investigated. The literature describes formation of halogenated hydrocarbons in effluent treatment using chlorine, hypochlorite and chlorine dioxide. A new chlorine dioxide product, originally intended as a H2S scavenger in the oil and gas industry, has been tested both as a phenol scavenger and H2S-scavenger for produced water applications. The concern about the possible formation of halogenated by-products initiated laboratory testing of chlorine dioxide as phenol and H2S scavenger for produced water applications. The tests also included synthetic matrixes containing phenols, and the tests show that halogenated phenols, mainly brominated species, are found in produced water after treatment with chlorine dioxide. Due to potential environmental risk from halogenated organic contaminants, the use of chlorine dioxide as phenol and H2S scavenger is not recommended. (Author)

  16. The Eocene Rusayl Formation, Oman, carbonaceous rocks in calcareous shelf sediments: Environment of deposition, alteration and hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Dill, H.G.; Wehner, H.; Kus, J. [Federal Institute for Geosciences and Natural Resources, P.O. Box 510163, D-30631 Hannover (Germany); Botz, R. [University Kiel, Geological-Paleontological Department, Olshausenstrasse 40-60, D-24118 Kiel (Germany); Berner, Z.; Stueben, D. [Technical University Karlsruhe, Institute for Mineralogy and Geochemistry, Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Al-Sayigh, A. [Sultan Qaboos University, Geological Dept. PO Box 36, Al-Khod (Oman)

    2007-10-01

    incursions make up a greater deal of the sedimentary record than mangrove swamps. Terra rossa paleosols mark the end of accumulation of organic material (OM) and herald supratidal conditions at the passage of Rusayl Formation into the overlying Seeb Formation. In the subtidal-supratidal cycles of lithofacies unit VIII the terra rossa horizons are thining upwards and become gradually substituted for by deep-water middle ramp sediments of lithofacies unit IX. Framboidal pyrite, (ferroan) dolomite with very little siderite are indicative of an early diagenetic alteration stage I under rather moderate temperatures of formation. During a subsequent stage II, an increase in the temperature of alteration was partly induced by burial and a high heat flow from the underlying Semail Ophiolite. Type-III kerogen originating from higher plants and, in addition, some marine biota gave rise to the generation of small amounts of soluble organic matter during this stage of diagenesis. The average reflectance of humic particles marks the beginning of the oil window and the production index reveals the existence of free hydrocarbons. Further uplift of the Eocene strata and oxidation during stage IIII caused veins of satin spar to form from organic sulfur and pyrite in the carbonaceous material. Lowering of the pH value of the pore fluid led to the precipitation of jarosite and a set of hydrated aluminum sulfates dependant upon the cations present in the wall rocks. AMD minerals (= acid mine drainage) are not very widespread in this carbonaceous series intercalated among calcareous rocks owing to the buffering effect of carbonate minerals. These carbonate-hosted carbonaceous rocks are below an economic level as far as the mining of coal is concerned, but deserves particular attention as source rocks for hydrocarbons in the Middle East, provided a higher stage of maturity is reached. (author)

  17. Towards field detection of polycyclic aromatic hydrocarbons (PAHs) in environment water using a self-assembled SERS sensor

    Science.gov (United States)

    Yan, Xia; Shi, Xiaofeng; Yang, Jie; Zhang, Xu; Jia, Wenjie; Ma, Jun

    2017-10-01

    A self-assembled surface enhanced Raman scattering (SERS) sensor is reported in this paper. To achieve high sensitivity, a high sensitive SERS substrate and a high efficient self-constructed light path were made. The SERS substrate was composed by gold nanoparticles (AuNPs, pH=13), glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material and syringe filter. The substrate had a good repeatability, and the relative standard deviation (RSD) of the same substrate was less than 5%. The efficiency of the self-constructed light path is about two times better than RPB Y type reflection fiber when the energy density was roughly equal on samples. The size of the SERS sensor is 350×300×180 mm and the weight is 15 kg. Its miniaturization and portable can comply with the requirements of field detection. Besides, it has good sensitivity, stability and selectivity. For lab experiments, strong enhancements of Raman scattering from organic pollutant polycyclic aromatic hydrocarbons (PAHs) molecules were exhibited. The dependences of SERS intensities on concentrations of PAHs were investigated, and the results indicated that they revealed a satisfactory linear relationship in low concentrations. The limits of detection (LODs) of PAHs phenanthrene and fluorene are 8.3×10-10 mol/L and 7.1×10-10 mol/L respectively [signal to noise ratio (S/N) =3]. Based on this SERS sensor, signals of benzo (a) pyrene and pyrene were found in environmental water and the sensor would be an ideal candidate for field detection of PAHs.

  18. Assessment of climate change impact on the fates of polycyclic aromatic hydrocarbons in the multimedia environment based on model prediction.

    Science.gov (United States)

    Cai, Juan Juan; Song, Jee Hey; Lee, Yunah; Lee, Dong Soo

    2014-02-01

    The objective was to quantitatively understand the impacts of climate change (CC) under the A1B scenario on the contamination levels of 11 polycyclic aromatic hydrocarbons (PAHs) from pyrogenic sources in the environmental media based on model prediction. To predict the impacts of CC in South Korea, a revised version of KoEFT-PBTs, a dynamic multimedia model for persistent organic pollutants in South Korea, was used. Simulations were conducted for the period from 2000 to 2049 under the A1B scenario with the emission data for 2009 and the results for Seoul and Kangwon were compared to those under no climate change (NCC) scenario. Due to CC, the average of annual or monthly average concentration changes within a factor of two for the PAHs in air, soil and water. Time dependent comparison indicates that the maximum increase induced by CC in the monthly average concentration ranges from 10 to 10(2) in air and water. Change in advective flux due to wind speed difference between A1B and NCC dictates the change of the atmospheric PAHs levels while wet particle deposition due to rain rate difference contributes to some extent to the change of 5 and 6 ring PAHs. Whether the concentration change is positive or not depends primarily on the emission strength of internal sources relative to those in surrounding areas. The CC induced changes in atmospheric depositions and degradation rate in soil play a leading role in the change of soil concentration. In water, runoff and degradation are the key processes to the CC induced concentration change. Both in soil and water, the relative importance of individual key processes varies with PAHs. The difference between the two scenarios in wind speed and in rain rate shows stronger correlations with the concentration change than the temperature change. © 2013 Elsevier B.V. All rights reserved.

  19. Reaction of hydrocarbons on fly ash with special consideration of the formation of aromatic chlorinated compounds; Umsetzung von Kohlenwasserstoffen an Flugaschen unter besonderer Beruecksichtigung der Bildung von aromatischen Chlorverbindungen

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Leal, P.

    1998-08-01

    This paper deals with the formation of chlorinated organic compounds, especially of polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF), in catalytic reactions on fly ash in incineration plants. The formation of these toxic compounds via de-novo-synthesis (formation from residual carbon, inorganic chloride and oxygen) and from several precursors (n-hexane, naphthaline, benzene, toluene, benzaldehyde, 2-chlorophenol and fluorene) on fly ash and model fly ash was investigated. The results show that in incineration plants PCDD/F can be formed de-novo as well as from precursors. The most efficient precursors of PCDD were benzaldehyde and 2-chlorophenol. The highest yield of PCDF were found for fluorene. The pathways of the formation of PCDD and PCDF are different. Polychlorinated dibenzodioxins are partly formed by reactions between C{sub 6}-precursors, especially by condensation of chlorophenols. Such reactions between C{sub 6}-precursors do not play an important role in the formation of PCDF. These compounds are formed from structures of the residual carbon of the fly ash or from precursors which have two benzene rings bounded. (orig.) [Deutsch] Die vorliegende Arbeit beschaeftigt sich mit der Bildung chlorierter organischer Verbindungen, insbesondere polychlorierter Dibenzodioxine (PCDD) und Dibenzofurane (PCDF) bei katalytischen Reaktionen auf Flugaschen in Muellverbrennungsanlagen. Untersucht wurde die Bildung dieser Schadstoffe bei der de-novo-Synthese (Neubildung aus Restkohlenstoff, anorganischem Chlorid und Sauerstoff), sowie aus verschiedenen Vorlaeuferverbindungen (n-Hexan, Naphthalin, Benzol, Toluol, Benzaldehyd, 2-Chlorphenol und Fluoren) auf Flugaschen und Modellflugaschen. Die Ergebnisse haben gezeigt, dass in Muellverbrennungsanlagen PCDD/F sowohl aus dem Restkohlenstoff als auch aus Vorlaeuferverbindungen gebildet werden koennen. Unter den untersuchten Vorlaeuferverbindungen zeigten Benzaldehyd und 2-Chlorphenol die hoechste Umsetzung in

  20. Reactions of tetracycline antibiotics with chlorine dioxide and free chlorine.

    Science.gov (United States)

    Wang, Pei; He, Yi-Liang; Huang, Ching-Hua

    2011-02-01

    Tetracyclines (TCs) are a group of widely used antibiotics that have been frequently found in the aquatic environment. The potential reactions of TCs with common water disinfection oxidants such as chlorine dioxide (ClO(2)) and free available chlorine (FAC) have not been studied in depth and are the focus of this study. The oxidation kinetics of tetracycline, oxytetracycline, chlorotetracycline and iso-chlorotetracycline by ClO(2) and FAC are very rapid (with large apparent second-order rate constants k(app) = 2.24 × 10(5)-1.26 × 10(6) M(-1) s(-1) with ClO(2) and k(app) = 1.12 × 10(4)-1.78 × 10(6) M(-1) s(-1) with FAC at pH 7.0) and highly dependent on pH. Species-specific rate constants are obtained by kinetic modeling that incorporates pH-speciation of TCs and the oxidants (for FAC), and reveal that TCs primarily react with ClO(2) and FAC by their unprotonated dimethylamino group and deprotonated phenolic-diketone group. The modest difference in reactivity among the four TCs toward the oxidants is consistent with expectation and can be explained by structural influences on the two reactive moieties. Product evaluation shows that oxidation of TCs by ClO(2) leads to (hydr)oxylation and breakage of TC molecules, while oxidation of TCs by FAC leads to chlorinated and (hydr)oxylated products without any substantial ring breakage. Results of this study indicate that rapid transformation of TCs by oxidants such as ClO(2) and FAC under water and wastewater treatment conditions can be expected. © 2010 Elsevier Ltd. All rights reserved.

  1. Modeling chlorine isotope trends during sequential transformation of chlorinated ethenes

    NARCIS (Netherlands)

    Hunkeler, D.; van Breukelen, B.M.; Elsner, M.

    2009-01-01

    There is increasing interest in combined carbon-chlorine compound-specific isotope analysis (CSIA) to differentiate between contaminant sources and to assess transformation processes. However, the significant abundance of polychlorinated molecules with several heavy chlorine isotopes complicates the

  2. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total hydrocarbons...

  3. 40 CFR 86.317-79 - Hydrocarbon analyzer specifications.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer specifications....317-79 Hydrocarbon analyzer specifications. (a) Hydrocarbon measurements are to be made with a heated... measures hydrocarbon emissions on a dry basis is permitted for gasoline-fueled testing; Provided, That...

  4. Development of a Site-Specific Kinetic Model for Chlorine Decay and the Formation of Chlorination By-Products in Seawater

    Directory of Open Access Journals (Sweden)

    Suhur Saeed

    2015-07-01

    Full Text Available Chlorine is used commonly to prevent biofouling in cooling water systems. The addition of chlorine poses environmental risks in natural systems due to its tendency to form chlorination by-products (CBPs when exposed to naturally-occurring organic matter (NOM. Some of these CBPs can pose toxic risks to aquatic and benthic species in the receiving waters. It is, therefore, important to study the fate of residual chlorine and CBPs to fully understand the potential impacts of chlorination to the environment. The goal of this study was to develop improved predictions of how chlorine and CBP concentrations in seawater vary with time, chlorine dose and temperature. In the present study, chlorination of once-through cooling water at Ras Laffan Industrial City (RLIC, Qatar, was studied by collecting unchlorinated seawater from the RLIC cooling water system intake, treating it with chlorine and measuring time series of chlorine and CBP concentrations. Multiple-rate exponential curves were used to represent fast and slow chlorine decay and CBP formation, and site-specific chlorine kinetic relationships were developed. Through extensive analysis of laboratory measurements, it was found that only some of the control parameters identified in the literature were important for predicting residual chlorine and CBP concentrations for this specific location. The new kinetic relationships were able to significantly improve the predictability and validity of Generalized Environmental Modeling System for Surfacewaters (GEMSS-chlorine kinetics module (CKM, a three-dimensional hydrodynamic and chlorine kinetics and transport model when applied for RLIC outfall studies using actual field measurements.

  5. The aromatic polycyclic chlorinated hydrocarbons (HAPC) or ''dioxin'' 30 june 2000; Les hydrocarbures aromatiques polycycliques chlores (HAPC) ou ''dioxines'' 30 juin 2000

    Energy Technology Data Exchange (ETDEWEB)

    Coulombier, D.; Plenel, L.

    2000-06-01

    The authors propose in this paper a pocket-book on the dioxin also called HAPC. It presents the emission sources of the dioxin, the population exposed, the effects on the public health, the risk assessment, the dioxin in the food and the environment and the regulation in the domain. (A.L.B.)

  6. Reaction products of chlorine dioxide.

    Science.gov (United States)

    Stevens, A A

    1982-01-01

    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

  7. Carcinogenic potential, levels and sources of polycyclic aromatic hydrocarbon mixtures in indoor and outdoor environments and their implications for air quality standards.

    Science.gov (United States)

    Delgado-Saborit, Juana Maria; Stark, Christopher; Harrison, Roy M

    2011-02-01

    Both the World Health Organization and the UK Expert Panel on Air Quality Standards (EPAQS) have considered benzo(a)pyrene (BaP) as a marker of the carcinogenic potency of the polycyclic aromatic hydrocarbons (PAH) mixture, when recommending their respective guidelines for PAHs in outdoor air. The aim of this research is to compare the concentrations and relative abundance of individual PAH and their contribution to the overall carcinogenic potential of the PAH mixture in indoor and outdoor environments to assess the suitability of the UK air quality standard derived for outdoor air for use as a guideline for indoor environments. Samples were collected onto filters using active sampling in different indoor and outdoor microenvironments. The ratio of individual compounds to BaP, the BaP equivalent concentrations and the percentage contribution of each individual compound to the total carcinogenic potential of the PAH mixture were calculated. Mean concentrations were generally lower indoors (BaP=0.10 ng/m(3)) than outdoors (BaP=0.19 ng/m(3)), with the exception of indoor environments with wood burners (BaP=2.4 ng/m(3)) or ETS (BaP=0.6 ng/m(3)). The ratio of individual PAHs to BaP showed no significant differences between indoors (e.g. DahA/BaP=0.27) and outdoors (DahA/BaP=0.31). The relative contribution of BaP to the PAH overall carcinogenic potency is similar indoors (49%), outdoors (54%) and in the smelter environment (48%) used by EPAQS to derive the UK Air Quality Standard for ambient air. These results suggest the suitability of BaP as a marker for the carcinogenic potential of the PAH mixture irrespective of the environment. Despite small differences in PAH mixture composition indoors and outdoors, the level of protection afforded by the present EPAQS standard is likely to be similar whether it is applied to indoor or outdoor air. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Nature and sources of particle associated polycyclic aromatic hydrocarbons (PAH) in the atmospheric environment of an urban area.

    Science.gov (United States)

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

    2013-12-01

    The total PAH associated to the airborne particulate matter (PM10) was apportioned by one receptor model based on positive matrix factorization (PMF) in an urban environment (Zaragoza city, Spain) during February 2010-January 2011. Four sources associated with coal combustion, gasoline, vehicular and stationary emissions were identified, allowing a good modelling of the total PAH (R(2) = 0.99). A seasonal behaviour of the four factors was obtained with higher concentrations in the cold season. The NE direction was one of the predominant directions showing the negative impact of industrial parks, a paper factory and a highway located in that direction. Samples were classified according to hierarchical cluster analysis obtaining that, episodes with the most negative impact on human health (the highest lifetime cancer risk concentrations), were produced by a higher contribution of stationary and vehicular emissions in winter season favoured by high relative humidity, low temperature and low wind speed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Geochemical characterization of lower Toarcian source rocks from NW Germany: interpretation of aromatic and saturated hydrocarbons in relation to depositional environment and maturation effects

    Energy Technology Data Exchange (ETDEWEB)

    Radke, M.; Schaefer, R.G. [Institut fuer Erdol und Organische Geochemie, Juelich (Germany); Vriend, S.P. [University of Utrecht (Netherlands). Institute of Earth Sciences

    2001-07-01

    The characterization of crude oils in terms of source rock facies and depositional environment, as well as their maturity and alteration stage, is a crucial element in exploration studies. The present contribution has implications for oil-oil and oil-source rock correlations. In the past, numerous parameters have been used for this purpose most of which are based on the analysis of saturated and aromatic hydrocarbons (including sulphur aromatics) and also on stable isotope signatures and elemental compositions. Recently, molecular indicators based on dibenzothiophene (DBT), phenanthrene (PHE) and their methyl derivatives methyldlbenzothiophene (MDBT) an methylphenanthrene, as well as pristane (PRI) and phytane (PHY), have also been proposed (Hughes et al, 1995). These studies have attempted to infer a crude oil's source rock facies and lithology, and to classify the source rock's depositional environment. In the present study, the above compounds have been quantified by solvent extraction, liquid chromatography and capillary gas chromatography in 98 core samples of the Lower Toarcian Posidonia Shale Formation, a source rock in NW Germany. Most samples cored between depths of 7m and 70 m, came from the Hils Half-Graben in the Lower Saxony Basin. With a few exceptions from on borehole, the samples were unweathered maris or calcareous shales. The rocks contained mainly marine organic matter (Type 1 kerogen), the thermal maturity of which ranged from early mature to postmature (corresponding to 0.48-1.44% mean vitrinite reflectance), therefore encompassing the range over which effective petroleum generation had occurred. We found that the influence of organic matter type and maturity on the molecular distributions of the above compounds were not obvious when interpreted in term of a DBT/PHE vs PRI/PHY diagram. However, Principal Component Analysis (PCA) of our data-set showed that alkylphenanthren concentrations are strongly controlled by maturity, while the

  10. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  11. Rehabilitation of Seven (7) Hydrocarbon Contaminated Sites in a Brackish Water/Lagoon Environment in South Trinidad

    Science.gov (United States)

    Mohammed, Avryl; Ramnath, Kelvin; Dyal, Shyam; Lalla, Francesca; Roopchand, Jaipersad

    2007-12-01

    The Petroleum Company of Trinidad and Tobago Limited operates in a wide diversity of tropical habitats in South Trinidad one of which is a brackish water environment known as the Godineau Swamp. Historically this field was operated by predecessor multinational companies, who at that time employed operational practices based on the absence of legal requirements, that were not environmentally considerate. Following a detailed environmental audit of the field (also known as the Oropouche Field), seven (7) contaminated sites were found, that presented a risk to the lagoon and its associated mangrove swamp ecology. Remediation of the seven (7) sites was done in two (2) phases; phase 1 being sampling and characterization of the waste inclusive of migration and phase 2 the actual on-site soil remediation. Phase 1 conducted during the period December 2004 to February 2005, indicated a total of 19,484 m3 of contaminated material with TPH being the main contaminant. The average concentration of TPH was 3.25%. Phase 2 remediation was initiated in October 2005 and involved the following three (3) aspects to achieve a TPH concentration of less than 1%: ▪ Preparation of waste remediation sites adjacent to contaminated sites and excavation and spreading onto cells ▪ Bioremediation onsite using naturally occurring bacteria and rototilling ▪ Rehabilitation and closure of the site following accepted lab results. The benefits of conducting this project in the petroleum industry are to ensure compliance to the national Sensitive Areas Rules and Draft Waste Management Rules, conformance to ISO 14001 Certification requirements and conservation of biodiversity in the mangrove swamp.

  12. Polycyclic aromatic hydrocarbons (PAHs) in multimedia environment of Heshan coal district, Guangxi: distribution, source diagnosis and health risk assessment.

    Science.gov (United States)

    Huang, Huan-Fang; Xing, Xin-Li; Zhang, Ze-Zhou; Qi, Shi-Hua; Yang, Dan; Yuen, Dave A; Sandy, Edward H; Zhou, Ai-Guo; Li, Xiao-Qian

    2016-10-01

    Mining activities are among the major culprits of the wide occurrences of soil and water pollution by PAHs in coal district, which have resulted in ecological fragilities and health risk for local residents. Sixteen PAHs in multimedia environment from the Heshan coal district of Guangxi, South China, were measured, aiming to investigate the contamination level, distribution and possible sources and to estimate the potential health risks of PAHs. The average concentrations of 16 PAHs in the coal, coal gangue, soil, surface water and groundwater were 5114.56, 4551.10, 1280.12 ng g(-1), 426.98 and 381.20 ng L(-1), respectively. Additionally, higher soil and water PAH concentrations were detected in the vicinities of coal or coal gangue dump. Composition analysis, isomeric ratio, Pearson correlation analysis and principal component analysis were performed to diagnose the potential sources of PAHs in different environmental matrices, suggesting the dominant inputs of PAHs from coal/coal combustion and coal gangue in the soil and water. Soil and water guidelines and the incremental lifetime risk (ICLR) were used to assess the health risk, showing that soil and water were heavily contaminated by PAHs, and mean ICLRcoal/coal-gangue and mean ICLRsoil were both significantly higher than the acceptable levels (1 × 10(-4)), posing high potential carcinogenic risk to residents, especially coal workers. This study highlights the environmental pollution problems and public health concerns of coal mining, particularly the potential occupational health hazards of coal miners exposed in Heshan.

  13. Effect of chlorination condition and permeability of chlorine species on the chlorination of a polyamide membrane.

    Science.gov (United States)

    Gu, Joung-Eun; Jun, Byung-Moon; Kwon, Young-Nam

    2012-10-15

    Most studies on membrane chlorination have been investigated in an unpressurized chlorination mode, even if the polyamide membrane was continuously exposed to chlorine under high operating pressure in real water/wastewater treatment plants. In this study, performance changes due to polyamide membrane chlorination were investigated in both pressurized and unpressurized chlorination modes. Chlorination in an unpressurized mode showed a flux increase at high pH and a flux decline at low pH due to the compaction and swelling of the polyamide chains, respectively. On the other hand, chlorination performed in a pressurized mode decreased the water flux in both acidic and alkaline conditions, showing that compaction is overwhelming compared to swelling. The permeability of HOCl, a dominant species at low pH, through the polyamide membrane was pH independent and almost similar to the system recovery, but the permeability of OCl(-), which is dominant at high pH, was maxima at a neutral pH. The different performance behaviors of membranes chlorinated at various pH conditions in the presence or absence of applied pressure could be explained by the permeability of chlorine species and compaction/swelling of polymer chains after chlorination. The effect of membrane chlorination on the chemical property changes at the two different modes was confirmed using attenuated total reflection Fourier transform infrared analysis, and a conceptual model of performance change was proposed to explain the performance discrepancy between the two chlorination modes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Chlorinated lime poisoning

    Science.gov (United States)

    Chlorinated lime poisoning can cause symptoms in many parts of the body. BLOOD Severe change in the acid level in the blood (pH balance), which leads to damage in all of the body organs EYES, EARS, NOSE, AND THROAT Loss of vision Severe pain ...

  15. Impacts of Water Chlorination

    Science.gov (United States)

    Environmental Science and Technology, 1976

    1976-01-01

    To learn the consequences of one aspect of technology on man and his surroundings, scientists meeting at the Oak Ridge National Laboratory discussed what is known about the impacts of water chlorination. The conference produced state-of-the-art information about the technology and attempted to summarize all the information on the subject. (BT)

  16. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Science.gov (United States)

    2010-07-01

    ... (HCl) and chlorine gas (Cl2) emissions. 266.107 Section 266.107 Protection of Environment ENVIRONMENTAL... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine (Cl2...

  17. Chlorine in Lunar Basalts

    Science.gov (United States)

    Barnes, J. J.; Anand, M.; Franchi, I. A.

    2017-01-01

    In the context of the lunar magma ocean (LMO) model, it is anticipated that chlorine (and other volatiles) should have been concentrated in the late-stage LMO residual melts (i.e., the dregs enriched in incompatible elements such as K, REEs, and P, collectively called KREEP, and in its primitive form - urKREEP, [1]), given its incompatibility in mafic minerals like olivine and pyroxene, which were the dominant phases that crystallized early in the cumulate pile of the LMO (e.g., [2]). When compared to chondritic meteorites and terrestrial rocks (e.g., [3-4]), lunar samples often display heavy chlorine isotope compositions [5-9]. Boyce et al. [8] found a correlation between delta Cl-37 (sub Ap) and bulk-rock incompatible trace elements (ITEs) in lunar basalts, and used this to propose that early degassing of Cl (likely as metal chlorides) from the LMO led to progressive enrichment in remaining LMO melt in Cl-37over Cl-35- the early degassing model. Barnes et al. [9] suggested that relatively late degassing of chlorine from urKREEP (to yield delta Cl-37 (sub urKREEP greater than +25 per mille) followed by variable mixing between KREEPy melts and mantle cumulates (characterized by delta Cl-370 per mille) could explain the majority of Cl isotope data from igneous lunar samples. In order to better understand the processes involved in giving rise to the heavy chlorine isotope compositions of lunar samples, we have performed an in situ study of chlorine isotopes and abundances of volatiles in lunar apatite from a diverse suite of lunar basalts spanning a range of geochemical types.

  18. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Tier I Feed Rate Screening Limits for Total Chlorine II Appendix II to Part 266 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Screening Limits for Total Chlorine Terrain-adjusted effective stack height (m) Noncomplex Terrain Urban (g...

  19. 40 CFR Table 2b to Subpart E of... - Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... Hydrocarbon Solvent Mixtures 2B Table 2B to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Averageboiling point * (degrees F) Criteria Reactivityfactor 1 80-205 Alkanes... + Dry Point) / 2 (b) Aromatic Hydrocarbon Solvents ...

  20. Chlorinated organic compounds in urban river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Soma, Y.; Shiraishi, H.; Inaba, K. [National Inst. of Environmental Studies, Tsukuba, Ibaraki (Japan)

    1995-12-31

    Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

  1. Chlorine Gas Inhalation

    Science.gov (United States)

    White, Carl W.; Martin, James G.

    2010-01-01

    Humans can come into contact with chlorine gas during short-term, high-level exposures due to traffic or rail accidents, spills, or other disasters. By contrast, workplace and public (swimming pools, etc.) exposures are more frequently long-term, low-level exposures, occasionally punctuated by unintentional transient increases. Acute exposures can result in symptoms of acute airway obstruction including wheezing, cough, chest tightness, and/or dyspnea. These findings are fairly nonspecific, and might be present after exposures to a number of inhaled chemical irritants. Clinical signs, including hypoxemia, wheezes, rales, and/or abnormal chest radiographs may be present. More severely affected individuals may suffer acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS). Up to 1% of exposed individuals die. Humidified oxygen and inhaled β-adrenergic agents are appropriate therapies for victims with respiratory symptoms while assessments are underway. Inhaled bicarbonate and systemic or inhaled glucocorticoids also have been reported anecdotally to be beneficial. Chronic sequelae may include increased airways reactivity, which tends to diminish over time. Airways hyperreactivity may be more of a problem among those survivors that are older, have smoked, and/or have pre-existing chronic lung disease. Individuals suffering from irritant-induced asthma (IIA) due to workplace exposures to chlorine also tend to have similar characteristics, such as airways hyperresponsiveness to methacholine, and to be older and to have smoked. Other workplace studies, however, have indicated that workers exposed to chlorine dioxide/sulfur dioxide have tended to have increased risk for chronic bronchitis and/or recurrent wheezing attacks (one or more episodes) but not asthma, while those exposed to ozone have a greater incidence of asthma. Specific biomarkers for acute and chronic exposures to chlorine gas are currently lacking. Animal models for chlorine gas

  2. Reaction kinetics and transformation of antipyrine chlorination with free chlorine.

    Science.gov (United States)

    Cai, Mei-Quan; Feng, Li; Jiang, Jin; Qi, Fei; Zhang, Li-Qiu

    2013-05-15

    Chlorine has been documented that it can effectively remove some pharmaceuticals. Recently, new active oxidants chlorine monoxide and molecular chlorine, which exist as free active chlorine in solution, were reported during pharmaceuticals chlorination. In this study, reaction kinetics, active oxidants, and transformation products during antipyrine chlorination were investigated with batch experiments. The reaction orders in [chlorine] were determined at various pH (6.53-7.62) and ranged from 1.13 ± 0.15 to 1.59 ± 0.08, which indicated that antipyrine chlorination is the concurrent existence of reactions appearing first-order and second-order in [chlorine]. The results by varying solution conditions (solution pH, chloride, ionic strength, and buffer concentration) show that chlorine monoxide and molecular chlorine play significant roles during the process of antipyrine chlorination. With kinetics modeling, the second-order rate constants for hypochlorous acid, chlorine monoxide, and molecular chlorine were obtained at 25 ± 2 °C (units: M(-1) s(-1)): kHOCl = 3.23 × 10(3), kCL2 = 2.86 × 10(7), kCL2O= 8.38 × 10(9) (R(2) = 0.9801). At pH 7, hypochlorous acid and chlorine monoxide are the main contributors to the degradation of antipyrine, about 80% and 20%, respectively (calculated by kHOCl, kCL2 and kCL2O. By applying these rate constants to predict the antipyrine elimination in real water matrixes (surface water, ground water), a good agreement was obtained, particularly in ground water. Moreover, liquid chromatography-tandems mass spectrometry (LC-MS/MS) and gas chromatograph-mass spectrometry (GC-MS) were used for products identification. Two main intermediate products and three stable products were observed during the process of antipyrine chlorination. The possible routes for antipyrine chlorination were proposed, which mainly consisted of halogenations, dealkylations and hydroxylations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from a UH-1H helicopter engine and its impact on the ambient environment

    Science.gov (United States)

    Chen, Yu-Cheng; Lee, Wen-Jhy; Uang, Shi-Nian; Lee, Su-Hsing; Tsai, Perng-Jy

    The objective of this study is to characterize the emissions of polycyclic aromatic hydrocarbons (PAHs) from a UH-1H helicopter turboshaft engine and its impact on the ambient environment. Five power settings of the ground idle (GI), fly idle (FI), beed band check (BBC), inlet guide vane (IGV), and take off (TO) were selected and samples were collected from the exhaust by using an isokinetic sampling system. Twenty-two PAH compounds were analyzed by gas chromatograph (GC)/MS. We found the mean total PAH concentration in the exhaust of the UH-1H engine (843 μg m -3) is 1.05-51.7 times in magnitude higher than those of the heavy-duty diesel (HDD) engine, motor vehicle engine, and F101 aircraft engine. Two- and three-ringed PAHs account for 97.5% of total PAH emissions from the UH-1H engine. The mean total PAH and total BaP eq emission factors for the UH-1H engine (63.4 and 0.309 mg L -1·fuel) is 1.65-23.4 and 1.30-7.54 times in magnitude higher than those for the motor vehicle engine, HDD engine, and F101 aircraft engine. The total emission level of the single PAH compound, BaP, for the UH-1H engine (EL BaP) during one landing and take off (LTO) cycle (2.19 mg LTO -1) was higher than the European Commission standard (1.24 mg LTO -1) suggesting that appropriate measures should be taken to reduce PAH emissions from UH-1H engines in the future.

  4. Biodegradation of gasoline in environment: from total assessment to the case of recalcitrant hydrocarbons; Biodegradabilite de l'essence dans l'environnement: de l'evaluation globale au cas des hydrocarbures recalcitrants

    Energy Technology Data Exchange (ETDEWEB)

    Solano-Serena, F.

    1999-11-26

    Because of their massive utilisation, hydrocarbons are major pollutants of soils and aquifers. Biodegradation is a key aspect of the fate of pollutants in the environment. Such knowledge, concerns in particular the intrinsic biodegradability of the products and the distribution in the environment of competent degradative microflora. In this study, a methodology has been developed to assess the aerobic biodegradability of gasoline. It is based on the direct gas chromatographic analysis of all hydrocarbons, after incubation in optimal conditions, of gasoline fractions and of model mixtures. The results demonstrated first the quasi-total biodegradability of gasoline ({>=} 94%). Concerning the distribution in the environment of degradative capacities, even microflora from non polluted sites exhibited a high performance (total degradation rates at least 85%) but were limited concerning the degradation of trimethyl-alkanes, such as 2,2,4-trimethyl-pentane (iso-octane) and 2,3,4-trimethyl-pentane, and of cyclohexane. Samples of polluted sites exhibited more extensive degradative capacities with total degradation in half of the cases studied. Cyclohexane was always degraded by mutualism and/or co-metabolism. Trimethyl-alkanes with quaternary carbons such as iso-octane and/or alkyl groups on consecutive carbons were degraded by co-metabolism but could also support growth of specialized strains. A strain of Mycobacterium austroafricanum (strain IFP 2173) growing on iso-octane was isolated from a gasoline polluted sample. This strain exhibited the capacity to co-metabolize various hydrocarbons (cyclic and branched alkanes, aromatics) and in particular cyclohexane. M austroafricanum lFP 2173 was also able to use a large spectrum of hydrocarbons (n- and iso-alkanes, aromatics) as sole carbon and energy source. (author)

  5. Biodegradation of gasoline in the environment: from overall assessment to the case of recalcitrant hydrocarbons; Biodegradabilite de l'essence dans l'environnement: de l'evaluation globale au cas des hydrocarbures recalcitrants

    Energy Technology Data Exchange (ETDEWEB)

    Solano-Serena, F.; Marchal, R.; Vandecasteele, J.P. [Institut Francais du Petrole (IFP), Dept. de Microbiologie, 92 - Rueil-Malmaison (France)

    2001-07-01

    Because of their massive utilisation, hydrocarbons are major pollutants of soils and aquifers. Biodegradation is a key aspect of the fate of pollutants in the environment. Such knowledge concerns in particular the intrinsic biodegradability of the products and the distribution in the environment of competent degradative microflora. In this study, a methodology has been developed to assess the aerobic biodegradability of gasoline. It is based on the direct gas chromatographic analysis of all hydrocarbons, after incubation in optimal conditions, of gasoline fractions and of model mixtures. The results first demonstrated the quasi-total biodegradability of gasoline (94%). Concerning the distribution in the environment of degradative capacities, even microflora from non-polluted sites exhibited a high performance (total degradation rate: at least 85%) but were limited concerning the degradation of trimethyl-alkanes, such as 2,2,4-trimethyl-pentane (iso-octane) and 2,3,4-trimethyl-pentane, and of cyclohexane. Samples of polluted sites exhibited more extensive degradative capacities with total degradation in half of the cases studied. Cyclohexane was always degraded by mutualism and/or co-metabolism. Trimethyl-alkanes with quaternary carbons such as iso-octane and/or alkyl groups on consecutive carbons were degraded by co-metabolism but could also support growth of specialized strains. A strain of Mycobacterium austroafricanum (strain IFP 2173) growing on iso-octane was isolated from a gasoline-polluted sample. This strain exhibited the capacity to co-metabolize various hydrocarbons (cyclic and branched alkanes, aromatics) and in particular cyclohexane. M. austroafricanum IFP 2173 was also able to use a large spectrum of hydrocarbons (n- and iso-alkanes, aromatics) as sole carbon and energy source. (authors)

  6. Enhanced Attenuation: Chlorinated Organics

    Science.gov (United States)

    2008-04-01

    permeability of soils overlying a source zone or favorably manipulate the soil water balance so as to limit percolation through a source zone...designs rely on the low permeability of a compacted soil layer to limit percolation (EPA 1989). Alternative covers meanwhile are designed to accommodate...plumes that include chlorinated organics. The flux of organic-rich leachate to underlying aquifers can create favorable conditions for the natural

  7. Tolerance of Antarctic soil fungi to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Kevin A.; Bridge, Paul; Clark, Melody S. [British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET (United Kingdom)

    2007-01-01

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

  8. Ultrafast Third-Order Nonlinear Optical Spectroscopy of Chlorinated Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Napoleon Thantu; Robert S. Schley

    2003-09-01

    Time-resolved Raman induced Kerr effect spectroscopy in the optical heterodyne detection configuration has been employed to investigate intermolecular, intramolecular, and reorientational dynamics in neat trichloroethylene (TCE). The reorientation time constant is directly measured from the time-resolved data, while Fourier transformation of the time-resolved data yields the intermolecular and intramolecular vibrational spectrum. Use of ultrashort, femtosecond pulses enables excitation of depolarized Raman-active transitions between 1 and 500 cm-1. The intramolecular vibrations have been identified using a previous assignment. The limitations imposed by the laser and detector noise, and other nonlinear optical processes that are manifest at high pulse intensities, on the use of this time-domain technique for performing chemical species detection are discussed using carbon tetrachloride as an example.

  9. Studies on degradation of chlorinated aromatic hydrocarbon by ...

    African Journals Online (AJOL)

    SERVER

    2007-06-04

    Jun 4, 2007 ... to develop specific intracellular enzymes which will decompose chlorobenzene to non-toxic substances. Crude cell extracts produced ... ironment with wastewater and exhaust, great numbers are benzene derivatives and other ... Although acute toxicity is uncommon, these substances cause sublethal ...

  10. In situ remediation of chlorinated solvent-contaminated groundwater using ZVI/organic carbon amendment in China: field pilot test and full-scale application.

    Science.gov (United States)

    Yang, Jie; Meng, Liang; Guo, Lin

    2018-02-01

    Chlorinated solvents in groundwater pose threats to human health and the environment due to their carcinogenesis and bioaccumulation. These problems are often more severe in developing countries such as China. Thus, methods for chlorinated solvent-contaminated groundwater remediation are urgently needed. This study presents a technique of in situ remediation via the direct-push amendment injection that enhances the reductive dechlorination of chlorinated solvents in groundwater in the low-permeability aquifer. A field-based pilot test and a following real-world, full-scale application were conducted at an active manufacturing facility in Shanghai, China. The chlorinated solvents found at the clay till site included 1,1,1-trichloroethane (1,1,1-TCA), 1,1-dichloroethane (1,1-DCA), 1,1-dichloroethylene (1,1-DCE), vinyl chloride (VC), and chloroethane (CA). A commercially available amendment (EHC ® , Peroxychem, Philadelphia, PA) combining zero-valent iron and organic carbon was used to treat the above pollutants. Pilot test results showed that direct-push EHC injection efficiently facilitated the in situ reductive remediation of groundwater contaminated with chlorinated solvents. The mean removal rates of 1,1,1-TCA, 1,1-DCA, and 1,1-DCE at 270 days post-injection were 99.6, 99.3, and 73.3%, respectively, which were obviously higher than those of VC and CA (42.3 and 37.1%, respectively). Clear decreases in oxidation-reduction potential and dissolved oxygen concentration, and increases in Fe 2+ and total organic carbon concentration, were also observed during the monitoring period. These indicate that EHC promotes the anaerobic degradation of chlorinated hydrocarbons primarily via long-term biological reductive dechlorination, with instant chemical reductive dechlorination acting as a secondary pathway. The optimal effective time of EHC injection was 0-90 days, and its radius of influence was 1.5 m. In full-scale application, the maximum concentrations of 1,1,1-TCA

  11. Bioaccumulation and cancer risk of polycyclic aromatic hydrocarbons in leafy vegetables grown in soils within automobile repair complex and environ in Uyo, Nigeria.

    Science.gov (United States)

    Inam, Edu; Ibanga, Felicia; Essien, Joseph

    2016-12-01

    Using gas chromatography-mass spectrometry and an incremental lifetime cancer risks (ILCRs) assessment model, the bioaccumulation and cancer risk of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) in leafy vegetables (Vernonia amygdalina and Lasianthera africanum) grown in soils within an automobile repair complex environment in Uyo, Nigeria was studied. The total PAHs concentrations recorded for soils ranged from 0.02 to 1.77 mg/kg. The highest level of 1.77 mg/kg was recorded for soils from the main automobile repair complex (site 1). Low molecular weight (LMW) PAHs were predominant although some high molecular weight (HMW) PAHs suites (0.04 mg/kg of chrysene and 0.04 of benzo[k]fluoranthene) were also found in site 1. The leafy vegetables accumulated PAHs were mostly LMW. Accumulation levels were similar but the extent of PAH uptake in vegetables was species dependent as V. amygdalina accumulated more (0.81 mg/kg). The bioaccumulation factors (BaFs) calculated ranged from 0.22 to 0.63 for L. africanum, and 0.18 to 0.55 for V. amygdalina in site 1 where high PAH levels were recorded in soil. Pearson correlation coefficient analysis revealed a strong positive relation between the PAH content of soil and the amount accumulated by L. africanum (r = 0.5) and V. amygdalina (r = 0.8) at p = 0.05. The vegetable's potential to bioaccumulate PAHs is indicative of their use as good bioindicators for PAH contamination in soil. Only two of the USEPA possible human carcinogenic PAHs were detected, and carcinogenic risk assessment based on occupational exposures to soil particles by adults revealed that the total risk level (7.17 × 10-5) contribution from incidental soil ingestion, dermal contact, and soil particle dust inhalation slightly exceed the USEPA acceptable limits (vegetables grown in and around automobile repair complexes across Nigeria.

  12. Chlorine, Chloramine, Chlorine Dioxide, and Ozone Susceptibility of Mycobacterium avium

    Science.gov (United States)

    Taylor, Robert H.; Falkinham, Joseph O.; Norton, Cheryl D.; LeChevallier, Mark W.

    2000-01-01

    Environmental and patient isolates of Mycobacterium avium were resistant to chlorine, monochloramine, chlorine dioxide, and ozone. For chlorine, the product of the disinfectant concentration (in parts per million) and the time (in minutes) to 99.9% inactivation for five M. avium strains ranged from 51 to 204. Chlorine susceptibility of cells was the same in washed cultures containing aggregates and in reduced aggregate fractions lacking aggregates. Cells of the more slowly growing strains were more resistant to chlorine than were cells of the more rapidly growing strains. Water-grown cells were 10-fold more resistant than medium-grown cells. Disinfectant resistance may be one factor promoting the persistence of M. avium in drinking water. PMID:10742264

  13. Lethality of chlorine, chlorine dioxide, and a commercial produce sanitizer to Bacillus cereus and Pseudomonas in a liquid detergent, on stainless steel, and in biofilm.

    Science.gov (United States)

    Kreske, Audrey C; Ryu, Jee-Hoon; Pettigrew, Charles A; Beuchat, Larry R

    2006-11-01

    Many factors that are not fully understood may influence the effectiveness of sanitizer treatments for eliminating pathogens and spoilage microorganisms in food or detergent residues or in biofilms on food contact surfaces. This study was done to determine the sensitivities of Pseudomonas cells and Bacillus cereus cells and spores suspended in a liquid dishwashing detergent and inoculated onto the surface of stainless steel to treatment with chlorine, chlorine dioxide, and a commercial produce sanitizer (Fit). Cells and spores were incubated in a liquid dishwashing detergent for 16 to 18 h before treatment with sanitizers. At 50 microg/ml, chlorine dioxide killed a significantly higher number of Pseudomonas cells (3.82 log CFU/ml) than did chlorine (a reduction of 1.34 log CFU/ml). Stainless steel coupons were spot inoculated with Pseudomonas cells and B. cereus cells and spores, with water and 5% horse serum as carriers. Chlorine was more effective than chlorine dioxide in killing cells and spores of B. cereus suspended in horse serum. B. cereus biofilm on stainless steel coupons that were treated with chlorine dioxide or chlorine at 200 microg/ml had total population reductions (vegetative cells plus spores) of > or = 4.42 log CFU per coupon; the number of spores was reduced by > or = 3.80 log CFU per coupon. Fit (0.5%) was ineffective for killing spot-inoculated B. cereus and B. cereus in biofilm, but treatment with mixtures of Fit and chlorine dioxide caused greater reductions than did treatment with chlorine dioxide alone. In contrast, when chlorine was combined with Fit, the lethality of chlorine was completely lost. This study provides information on the survival and sanitizer sensitivity of Pseudomonas and B. cereus in a liquid dishwashing detergent, on the surface of stainless steel, and in a biofilm. This information will be useful for developing more effective strategies for cleaning and sanitizing contact surfaces in food preparation and processing

  14. Basic Gas Chlorination Workshop Manual.

    Science.gov (United States)

    Ontario Ministry of the Environment, Toronto.

    This manual was developed for use at workshops designed to introduce treatment plant operators to the safe operation and maintenance of gas chlorination systems employing the variable vacuum gas chlorinator. Each of the lessons in this document has clearly stated behavioral objectives to tell the trainee what he should know or do after completing…

  15. [Combined use of active chlorine and coagulants for drinking water purification and disinfection].

    Science.gov (United States)

    Rakhmanin, Iu A; Zholdakova, Z I; Poliakova, E E; Kir'ianova, L F; Miasnikov, I N; Tul'skaia, E A; Artemova, T Z; Ivanova, L V; Dmitrieva, R A; Doskina, T V

    2004-01-01

    The authors made an experimental study of the efficiency of water purification procedures based on the combined use of active chlorine and coagulants and hygienically evaluated the procedures. The study included the evaluation of water disinfection with various coagulants and active chlorine; the investigation of the processes of production of deleterious organic chlorine compounds; the assessment of the quality of water after its treatment. The coagulants representing aluminum polyoxychloride: RAX-10 (AQUA-AURATE 10) and RAX-18 (AQUA-AURATE 18), and aluminum sulfate, technically pure grade were tested. The treatment of river water with the coagulants RAX-10 and RAX-18, followed by precipitation, filtration, and chlorination under laboratory conditions, was shown to result in water disinfection to the levels complying with the requirements described in SanPiN 2.1.4.1074-01. RAX-18 showed the best disinfecting activity against total and heat-tolerant coliform bacteria, but also to the highly chlorine-resistant microrganisms--the spores of sulfite-reducing Clostridia, phages, and viruses. Since the coagulants have an increased sorptive capacity relative to humus and other organic substances, substitution of primary chlorination for coagulant treatment may induce a reduction in the risk of formation of oncogenically and mutagenically hazardous chlorinated hydrocarbons.

  16. Disinfection kinetics of murine norovirus using chlorine and chlorine dioxide.

    Science.gov (United States)

    Lim, Mi Young; Kim, Ju-Mi; Ko, Gwangpyo

    2010-05-01

    We determined the disinfection efficiency of chlorine and chlorine dioxide (ClO(2)) using murine norovirus (MNV) and coliphage MS2 as surrogates for human norovirus. Experiments were performed in oxidant demand-free buffer (pH 7.2) at 5 degrees C and 20 degrees C. The extent of virus inactivation by a disinfectant was quantified using three different analytical methods: plaque, short template real-time TaqMan reverse transcriptase-polymerase chain reaction (RT-PCR), and long template RT-PCR assays. Rapid inactivation of MNV by both chlorine and chlorine dioxide was observed by the plaque assay. According to the efficiency factor Hom model, Ct values of 0.314mg/Lmin and 0.247mg/Lmin were required for a 4-log reduction of MNV at 5 degrees C by chlorine and chlorine dioxide, respectively. Lower Ct values were required at 20 degrees C. Both long template and short template RT-PCR assays significantly underestimated the virus inactivation compared to the plaque assay. Our study demonstrates that adequate treatment of water with either chlorine or ClO(2) is likely to effectively control the waterborne transmission of human norovirus.

  17. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this section...

  18. 40 CFR 52.777 - Control strategy: photochemical oxidants (hydrocarbons).

    Science.gov (United States)

    2010-07-01

    ... oxidants (hydrocarbons). 52.777 Section 52.777 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Control strategy: photochemical oxidants (hydrocarbons). (a) The requirements of subpart G of this chapter... for photochemical oxidants (hydrocarbons) in the Metropolitan Indianapolis Intrastate Region by May 31...

  19. 40 CFR 721.4365 - Substituted ethoxylated hydrocarbon (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted ethoxylated hydrocarbon... Specific Chemical Substances § 721.4365 Substituted ethoxylated hydrocarbon (generic). (a) Chemical... as Substituted ethoxylated hydrocarbon (PMN P-99-0313) is subject to reporting under this section for...

  20. 40 CFR 86.521-90 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.521-90 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon analyzer shall receive the following initial and periodic calibration. The...

  1. 40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86...-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1221-90 Hydrocarbon analyzer calibration. The FID hydrocarbon analyzer shall receive the following initial and periodic calibrations. (a) Initial and periodic...

  2. 40 CFR 86.331-79 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86....331-79 Hydrocarbon analyzer calibration. The following steps are followed in sequence to calibrate the hydrocarbon analyzer. It is suggested, but not required, that efforts be made to minimize relative response...

  3. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418) is...

  4. Trace Metals and Volatile Aromatic Hydrocarbon Content of ...

    African Journals Online (AJOL)

    Michael Horsfall

    knowledge of this hydrocarbon and non hydrocarbon contents and their behaviour when discharged on shore is very useful in the decontamination and effective management of the affected environment. (Osuji and. Achugasim, 2007). An important group of the hydrocarbon content of crude oil is the Benzene Toluene.

  5. Informative document halogenated hydrocarbon-containing waste

    NARCIS (Netherlands)

    Verhagen H

    1992-01-01

    This "Informative document halogenated hydrocarbon-containing waste" forms part of a series of "Informative documents waste materials". These documents are conducted by RIVM on the instructions of the Directorate General for the Environment, Waste Materials Directorate, in

  6. Monitoring of methotrexate chlorination in water.

    Science.gov (United States)

    Roig, B; Marquenet, B; Delpla, I; Bessonneau, V; Sellier, A; Leder, C; Thomas, O; Bolek, R; Kummerer, K

    2014-06-15

    Anti-cancer drugs are an important class of pharmaceutical products. Methotrexate (MTX) is a folic acid antagonist used in high doses as antimetabolite in anti-cancer treatment as well as in low doses for the treatment of rheumatoid arthritis and adults' psoriasis. In the past, several anti-cancer drugs, including methotrexate, have been found in the environment. Their presence in water, especially if used for the production of drinking water, is even in low concentrations of particular interest, due to the risk to retrieve them in the consumed water and their high activity and grave effects. But prior to usage as drinking water, raw waters are treated and chlorination is a common practice in several countries. As such a treatment can lead to the formation of organochlorine in water, the study of the fate of MTX during chlorination in a batch trial was carried out. The reaction was monitored by dissolved organic carbon (DOC) and by fluorescence and UV spectroscopy. Investigation of by-products formed was done with liquid chromatography/mass spectrometry (LC/MS). Under the given experimental conditions, Methotrexate was eliminated rapidly (t1/2 around 21 min). However, DOC elimination was incomplete. Monitoring with LC-MS showed the formation of a monochlorinated transformation product of MTX. In silico analysis of the proposed transformation products for different carcinogenic, mutagenic and genotoxic endpoints with different software platforms provided no clear evidence that the possible transformation products after chlorination might be more toxic than the parent compound. However, since a number of alerts is altered after chlorination, it cannot be excluded that the toxicity of these transformation products might be modulated compared with the parent compound. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Direct Push Optical Screening Tool for High Resolution, Real-Time Mapping of Chlorinated Solvent DNAPL Architecture

    Science.gov (United States)

    2016-07-01

    is historically used in subsurface environmental assessments it i the natural fluorescence of polycyclic aromatic hydrocarbons (PAHs) found in the...sites impacted by petroleum hydrocarbon fuels, creosotes, and MGP tars. The rapid, high-resolution, real-time nature of LIF technologies described...ER-201121) Direct Push Optical Screening Tool for High- Resolution, Real-Time Mapping of Chlorinated Solvent DNAPL Architecture July 2016 This

  8. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride III Appendix III to Part 266 Protection of Environment... to Part 266—Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride Terrain...

  9. Transformation of cefazolin during chlorination process: products, mechanism and genotoxicity assessment.

    Science.gov (United States)

    Li, Liping; Wei, Dongbin; Wei, Guohua; Du, Yuguo

    2013-11-15

    Large quantities of cephalosporins have entered into aquatic environment in recent years, posing potential adverse effect to human health and ecological safety. In this study, cefazolin, one of widely used cephalosporins, was targeted to explore its transformation behaviors in chlorination disinfection process. With the help of ultra high performance liquid chromatography and high resolution mass spectroscopy, one chlorinated product and four oxidation products were detected in cefazolin chlorination system. The corresponding transformation pathways of cefazolin were proposed. Two kinds of reactions occurred in chlorination system, one was oxidation of thioether-sulfur to sulfoxide and di-sulfoxide, and the other was base-catalyzed electrophilic substitution of alpha-H of amide by chlorine atom. The pH value determined the occurrence of reaction types, and increasing chlorine dose promoted transformation of cefazolin. More importantly, genotoxicity in SOS/umu assay had an elevation after chlorination, which might be attributed to the formation of chlorinated product and sulfoxide during chlorination process. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Colorectal cancers and chlorinated water

    OpenAIRE

    El-Tawil, Ahmed Mahmoud

    2016-01-01

    Published reports have revealed increased risk of colorectal cancers in people exposed to chlorinated drinking water or chemical derivatives of chlorination. Oestrogen plays a dual positive functions for diminishing the possibilities of such risk by reducing the entrance, and increasing the excretion, of these chemicals. In addition, there are supplementary measures that could be employed in order to reduce this risk further, such as boiling the drinking water, revising the standard concentra...

  11. Grundfoss: Chlorination of Swimming Pools

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Hogan, John; Andreassen, Viggo

    1998-01-01

    Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools.......Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools....

  12. Transformation of chlorinated compounds by methanogenic granular sludge

    NARCIS (Netherlands)

    Eekert, van M.H.A.

    1999-01-01

    Chlorinated compounds are an important group of contaminants often found in sediments, groundwater, soils, wastewaters, and off-gasses. Many of these pollutants are found on the EPA list of Priority Pollutants indicating their potential hazard for the environment. Initial degradation can

  13. Chlorination of tramadol: Reaction kinetics, mechanism and genotoxicity evaluation.

    Science.gov (United States)

    Cheng, Hanyang; Song, Dean; Chang, Yangyang; Liu, Huijuan; Qu, Jiuhui

    2015-12-01

    Tramadol (TRA) is one of the most detected analgesics in environmental matrices, and it is of high significance to study the reactivity of TRA during chlorination considering its potential toxicity to the environment. The chlorine/TRA reaction is first order with respect to the TRA concentration, and a combination of first-order and second-order with respect to chlorine concentration. The pH dependence of the observed rate constants (kobs) showed that the TRA oxidation reactivity increased with increasing pH. kobs can be quantitatively described by considering all active species including Cl2, Cl2O and HOCl, and the individual rate constants of HOCl/TRA(0), HOCl/TRAH(+), Cl2/TRA and Cl2O/TRA reactions were calculated to be (2.61±0.29)×10(3)M(-1)s(-1), 14.73±4.17M(-1)s(-1), (3.93±0.34)×10(5)M(-1)s(-1) and (5.66±1.83)×10(6)M(-1)s(-1), respectively. Eleven degradation products were detected with UPLC-Q-TOF-MS, and the corresponding structures of eight products found under various pH conditions were proposed. The amine group was proposed to be the initial attack site under alkaline pH conditions, where reaction of the deprotonated amine group with HOCl is favorable. Under acidic and neutral pH conditions, however, two possible reaction pathways were proposed. One is an electrophilic substitution on the aromatic ring, and another is an electrophilic substitution on the nitrogen, leading to an N-chlorinated intermediate, which can be further oxidized. Finally, the SOS/umu test showed that the genotoxicity of TRA chlorination products increased with increasing dosage of chlorine, which was mostly attributed to the formation of some chlorine substitution products. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

    Directory of Open Access Journals (Sweden)

    Takashi Furukawa

    2017-07-01

    Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

  15. Can chlorination co-select antibiotic-resistance genes?

    Science.gov (United States)

    Lin, Wenfang; Zhang, Menglu; Zhang, Shenghua; Yu, Xin

    2016-08-01

    Selective pressures, such as chemical or heavy metal pollution, may co-select for bacterial antibiotic resistance in the environment. However, whether chlorination in water treatment can co-select antibiotic-resistant bacteria is controversial. In this study, high capacity quantitative polymerase chain reaction (qPCR) analysis was applied to target almost all known antibiotic-resistance genes (ARGs) (282 types) and 13 mobile genetic elements (MGEs) in bacteria detected in secondary effluents from a municipal wastewater treatment plant after chlorination. The results revealed that 125 unique ARGs were detected in non-chlorinated samples, and the number decreased (79-91 types) as the chlorine concentration was increased. Moreover, 7.49 × 10(4)-3.92 × 10(7) copies/100 ml water reduction of ARGs occurred with 4 mg Cl2/l. Considering the relative abundance of ARGs (i.e., ARG copies normalized to 16S rRNA gene copies), 119 ARGs decreased in response to chlorination, whereas only six ARGs, such as dfrA1, tetPB-03, tetPA, ampC-04, tetA-02, and erm(36), were potentially enriched by 10.90-, 10.06-, 8.63-, 6.86-, 3.77-, and 1.09-fold, respectively. Furthermore, the relative abundance of 12 detected MGEs was lower after chlorination. Therefore, chlorination was effective in reducing ARGs and MGEs rather than co-selecting them. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Spatial representation of underground hydrocarbon propagation hazard - application to alluvial environments; Representation spatiale des risques de propagation des pollutions par hydrocarbures en milieu souterrain - application au milieu alluvial

    Energy Technology Data Exchange (ETDEWEB)

    Anker, W.

    1997-11-14

    This PhD-thesis work is intended for the elaboration of a methodology for risk analysis of accidental hydrocarbon pollution. This methodology is based on the integration of modelling tools for complex phenomena of subsurface pollution by LNAPL (Light Non Aqueous Phase Liquids). In unsaturated zone, poly-phase character of hydrocarbon pollution is evident while air, water and oil phases coexist. Modelling of multiphase pollution propagation is limited by numerous uncertainties introduced by phenomena of nonlinearity. Nevertheless, spatial and temporal scale is smaller than in saturated zone. By this, the introduced error for risk estimation of this kind of model is more limited; In saturated zone, pollution is spreading in dissolved form: for this, we use simulation approach hydro-dispersive modelling. In this zone, essential transfer direction is horizontal. By this, necessity is imposed to dispose of a spatial analysis tool for risk estimation. For homogenization of error the whole distance of a pointwise pollution, influence of the scale where dispersities have been determined, has to be taken into account. By Geographic Information System, we introduce spatial parameters into hydrodynamic models. Model results are interpreted by spatial analysis to represent spatio-temporal evolution of pollution propagation. (author)

  17. Recent developments in capabilities for analysing chlorinated paraffins in environmental matrices: A review

    NARCIS (Netherlands)

    van Mourik, L.M.; Leonards, P.E.G.; Gaus, C.; de Boer, J.

    2015-01-01

    Concerns about the high production volumes, persistency, bioaccumulation potential and toxicity of chlorinated paraffin (CP) mixtures, especially short-chain CPs (SCCPs), are rising. However, information on their levels and fate in the environment is still insufficient, impeding international

  18. Petroleum Hydrocarbons, Chlorinated Hydrocarbons, and Metal in Soils and Sediments of Quivira National Wildlife Refuge, 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Numerous oil production facilities were in place when Quivira NWR was purchased, and oil production has continued and some new production facilities have been...

  19. Ships' Ballast Water Treatment by Chlorination Can Generate Toxic Trihalomethanes.

    Science.gov (United States)

    Hernandez, Marco R; Ismail, Nargis; Drouillard, Ken G; MacIsaac, Hugh J

    2017-08-01

    The International Maritime Organization (IMO) will enforce a new abundance-based performance standard for ballast water in September, 2017. Strong oxidants, like chlorine, have been proposed as a method for achieving this standard. However chlorine treatment of ballast water can produce hazardous trihalomethanes. We assessed maximum trihalomethane production from one chlorine dose for three types of ballast water (fresh, brackish and marine) and three levels of total organic carbon (TOC) concentration (natural, filtered, enhanced). While the current standard test considers a 5 day voyage, there is a high possibility of shorter trips and sudden change of plans that will release treated waters in the environment. Water source and TOC significantly affected trihalomethane production, with the highest amounts generated in brackish waters and enhanced TOC concentration. The concentration of brominated trihalomethanes increased from background levels and was highest in brackish water, followed by marine and fresh water.

  20. Transgenic plants and associated bacteria for phytoremediation of chlorinated compounds.

    Science.gov (United States)

    Van Aken, Benoit; Doty, Sharon Lafferty

    2010-01-01

    Phytoremediation is the use of plants for the treatment of environmental pollution, including chlorinated organics. Although conceptually very attractive, removal and biodegradation of chlorinated pollutants by plants is a rather slow and inefficient process resulting in incomplete treatment and potential release of toxic metabolites into the environment. In order to overcome inherent limitations of plant metabolic capabilities, plants have been genetically modified, following a strategy similar to the development of transgenic crops: genes from bacteria, fungi, and mammals involved in the metabolism of organic contaminants, such as cytochrome P-450 and glutathione S-transferase, have been introduced into higher plants, resulting in significant improvement of tolerance, removal, and degradation of pollutants. Recently, plant-associated bacteria have been recognized playing a significant role in phytoremediation, leading to the development of genetically modified rhizospheric and endophytic bacteria with improved biodegradation capabilities. Transgenic plants and associated bacteria constitute a new generation of genetically modified organisms for efficient and environmental-friendly treatment of polluted soil and water. This review focuses on recent advances in the development of transgenic plants and bacteria for the treatment of chlorinated pollutants, including chlorinated solvents, polychlorinated phenols, and chlorinated herbicides.

  1. Bacterial repopulation of drinking water pipe walls after chlorination.

    Science.gov (United States)

    Mathieu, Laurence; Francius, Grégory; El Zein, Racha; Angel, Edith; Block, Jean-Claude

    2016-09-01

    The short-term kinetics of bacterial repopulation were evaluated after chlorination of high-density polyethylene (HDPE) colonized with drinking water biofilms and compared with bare HDPE surfaces. The effect of chlorination was partial as a residual biofilm persisted and was time-limited as repopulation occurred immediately after water resupply. The total number of bacteria reached the same levels on both the bare and chlorinated biofilm-fouled HDPE after a seven-day exposure to drinking water. Due to the presence of a residual biofilm, the hydrophobicity of chlorinated biofilm-fouled surface exhibited much lower adhesion forces (2.1 nN) compared to bare surfaces (8.9 nN). This could explain the rapid repopulation after chlorination, with a twofold faster bacterial accumulation rate on the bare HDPE surface. γ-Proteobacteria dominated the early stages of repopulation of both surfaces and a shift in the dominance occurred over the colonization time. Such observations define a timescale for cleaning frequency in industrial environments and guidelines for a rinsing procedure using drinking water.

  2. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  3. Chemistry of combined residual chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Leao, S.F.; Selleck, R.E.

    1982-01-01

    The decay of the combined chlorine residual was investigated in this work. Recent concerns about the formation of undesirable compounds such as chloroform with free residual chlorination have focused attention on the alternative use of combined residual chlorination. This work investigates the applicability of reactions proposed to describe the transformations and decay of the combined residual with time. Sodium hypochlorite was added to buffered solutions of ammonia with the chlorine residual being monitored over periods extending up to 10 days. The reaction was studied at four initial concentrations of hypochlorite of 100, 50, 25 and 10 mg/L as Cl/sub 2/ with molar application ratios of chlorine to ammonia, defined herein as M ratios, of 0.90, 0.50, 0.25 and 0.05 at each hypochlorite dose. Sixty-eight experiments were conducted at the pH of 6.6 and 7.2. The conclusions are: (1) in the absence of free chlorine, the concentration of NH/sub 3/ does not seem to affect the rate of disappearance of the residual other than through the formation of NHCl/sub 2/ by NH/sub 2/Cl hydrolysis; (2) the reaction between NHCl/sub 2/ and NH/sub 4//sup +/ to form NH/sub 2/Cl is either much slower than reported by Gray et. al. or the mechanism is different with a rate limiting step not involving NH/sub 3/ or NH/sub 4//sup +/; (3) a redox reaction in addition to the first-order decomposition of NHCl/sub 2/ appears necessary. Model simulation results indicated that a reaction of the type NH/sub 2/Cl + NHCl/sub 2/ ..-->.. P added to the first-order NHCl/sub 2/ decomposition can explain the results observed except at the higher chlorine doses.

  4. Field-usable portable analyzer for chlorinated organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, W.J.; Penrose, W.R.; Stetter, J.R. [Transducer Research, Inc., Naperville, IL (United States)

    1995-10-01

    Transducer Research, Inc. (TRI) has been working with the DOE Morgantown Energy Technology Center to develop a new chemical monitor based on a unique sensor which responds selectively to vapors of chlorinated solvents. We are also developing field applications for the monitor in actual DOE cleanup operations. During the initial phase, prototype instruments were built and field tested. Because of the high degree of selectivity that is obtained, no response was observed with common hydrocarbon organic compounds such as BTX (benzene, toluene, xylene) or POLs (petroleum, oil, lubricants), and in fact, no non-halogen-containing chemical has been identified which induces a measurable response. By the end of the Phase I effort, a finished instrument system was developed and test marketed. This instrument, called the RCL MONITOR, was designed to analyze individual samples or monitor an area with automated repetitive analyses. Vapor levels between 0 and 500 ppm can be determined in 90 s with a lower detection limit of 0.2 ppm using the handportable instrument. In addition to the development of the RCL MONITOR, advanced sampler systems are being developed to: (1) extend the dynamic range of the instrument through autodilution of the vapor and (2) allow chemical analyses to be performed on aqueous samples. When interfaced to the samplers, the RCL MONITOR is capable of measuring chlorinated solvent contamination in the vapor phase up to 5000 ppm and in water and other condensed media from 10 to over 10,000 ppb(wt)--without hydrocarbon and other organic interferences.

  5. Petrology, palynology and organic geochemistry of Eocene lignite of Matanomadh, Kutch Basin, western India: Implications to depositional environment and hydrocarbon source potential

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Suryendu; Mathews, Runcie P.; Saraswati, Pratul K.; Banerjee, Santanu [Department of Earth Sciences, Indian Institute of Technology Bombay (India); Singh, Bhagwan D.; Tripathi, Suryakant M.; Singh, Alpana [Birbal Sahni Institute of Palaeobotany, Lucknow (India); Mann, Ulrich [Forschungszentrum Juelich (Germany). Institut fuer chemie und Dynamik der Geosphaere

    2011-01-01

    Petrological, palynological and organic-geochemical investigations were undertaken to determine the source vegetation, depositional conditions and hydrocarbon source potential of Eocene Matanomadh lignites from Kutch Basin, western India. The maceral study reveals that studied lignites are rich in huminite (av. 63%) with sub-ordinate amount of liptinite (av. 19%) and low inertinite (av. 3%), along with low to moderately high associated mineral matters (av. 15%). The overall petrographic composition points to a lagoonal condition for the formation of these lignites. The mean huminite reflectance values (R{sub r}: 0.28-0.34%, av. 0.31%) as well as low Rock-Eval T{sub max} (av. 417 C) values for the seams, suggest brown coal or lignitic stage/rank for the studied lignites. The palynological assemblages, dominated by tropical angiospermic pollen, suggest prevalence of warm humid tropical climate during the deposition of these lignites. The total organic carbon (TOC) content of lignites ranges between 26 and 58 wt.%, whereas the TOC content of the associated carbonaceous shales is around 4 wt.%. The Hydrogen Index (HI) ranging from 23 to 452 mg HC/g TOC indicates that the lignite sequence has the potential to produce mixed oil and gaseous hydrocarbons on maturation. The major pyrolysis products of lignites, derived from Curie point pyrolysis-GC-MS, are straight chain aliphatics, phenols and cadalene-based C{sub 15} bicyclic sesquiterpenoids. The exclusive occurrence of C{sub 15} bicyclic sesquiterpenoids suggests that these compounds are derived from dammar resin of angiosperm plants, belonging to family Dipterocarpaceae. (author)

  6. Chlorination and oxidation of sulfonamides by free chlorine: Identification and behaviour of reaction products by UPLC-MS/MS.

    Science.gov (United States)

    Gaffney, Vanessa de Jesus; Cardoso, Vitor Vale; Benoliel, Maria João; Almeida, Cristina M M

    2016-01-15

    Sulfonamides (SAs) are one class of the most widely used antibiotics around the world and have been frequently detected in municipal wastewater and surface water in recent years. Their transformation in waste water treatment plants (WWTP) and in water treatment plants (WTP), as well as, their fate and transport in the aquatic environment are of concern. The reaction of six sulfonamides (sulfamethoxazole, sulfapyridine, sulfamethazine, sulfamerazine, sulfathiazole and sulfadiazine) with free chlorine was investigated at a laboratory scale in order to identify the main chlorination by-products. A previously validated method, liquid chromatography/mass spectrometry, was used to analyse SAs and their chlorination by-products. At room temperature, pH 6-7, reaction times of up to 2 h and an initial concentration of 2 mg/L of free chlorine, the majority of SAs suffered degradation of around 65%, with the exception of sulfamethoxazole and sulfathiazole (20%). The main reaction of SAs with free chlorine occurred in the first minute. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 40 CFR 52.1486 - Control strategy: Hydrocarbons and ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Hydrocarbons and ozone. 52.1486 Section 52.1486 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... strategy: Hydrocarbons and ozone. (a) The requirements of subpart G of this chapter are not met since the...

  8. 40 CFR 86.221-94 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86.221-94 Section 86.221-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.221-94 Hydrocarbon analyzer...

  9. 40 CFR 52.987 - Control of hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of hydrocarbon emissions. 52.987 Section 52.987 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Louisiana § 52.987 Control of hydrocarbon emissions. (a) Notwithstanding any provisions...

  10. Reactions of aqueous chlorine and chlorine dioxide with model food compounds.

    Science.gov (United States)

    Fukayama, M Y; Tan, H; Wheeler, W B; Wei, C I

    1986-01-01

    Chlorine and chlorine dioxide (ClO2), common disinfecting and bleaching chemicals used in the food industry, are potent oxidizing and chlorinating agents. Unfortunately, little is known about the nature of the reactions of chlorine with organic food constituents. This presentation reviews published information concerning the reactions of chlorine gas (Cl2[g]), aqueous chlorine, and ClO2 with model food compounds, the fate of chlorine during the chlorination of specific food products, and the potential toxicity of the reaction products. Fatty acids and their methyl esters react with chlorine with the degree of incorporation corresponding to their degree of unsaturation. Aqueous chlorine oxidizes and chlorinates lipids and amino acids much more readily than ClO2. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and ClO2 with several food products, including flour and shrimp, have also been characterized. In one model system, 99% of Cl2(g) either reacted with components of flour or was consumed by oxidation/chlorination reactions. The lipids extracted from the chlorinated flour contained significant amounts of chlorine. Exposure of shrimp to hypochlorous acid (HOCl) solution resulted in significant incorporation of chlorine into the edible portion. Although significant quantities of chlorine can be incorporated into specific model compounds and food products, the health risks associated with exposure to chlorinated organic products are unknown. Preliminary studies using the Ames Salmonella/microsome mutagenicity assay indicate that the reaction products from mixtures of aqueous chlorine and various lipids or tryptophan are nonmutagenic. Nevertheless, additional studies are warranted, so that the toxicological significance of these reaction products can be understood more fully. PMID:3545804

  11. Formation of hydrocarbons by bacteria and algae

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G.

    1980-12-01

    A literature review has been performed summarizing studies on hydrocarbon synthesis by microorganisms. Certain algal and bacterial species produce hydrocarbons in large quantities, 70 to 80% of dry cell mass, when in a controlled environment. The nutritional requirements of these organisms are simple: CO/sub 2/ and mineral salts. The studies were initiated to determine whether or not microorganisms played a role in petroleum formation. 90 references. (DMC)

  12. Formation of aryl-chlorinated aromatic acids and precursors for chloroform in chlorination of humic acid

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Leer, E.W.B. de; Galan, L.

    1985-01-01

    The formation of chloroform when humic substances are chlorinated is well known. Other chlorinated products that may be formed are chloral, di- and trichloroacetic acid, chlorinated C-4 diacids, and α-chlorinated aliphatic acids. Several of these compounds are formed in molar yields comparable

  13. Biological airfilter for air quality control of life support systems in closed environments

    Science.gov (United States)

    van der Waarde, J. J.; Team

    Environmental quality assurance and recycling of raw materials are essential elements in manned space craft missions. Indoor air quality plays an important role, since the limited amount of air in the space craft is continuously recycled. Both astronaut activities and materials and equipment onboard the space craft are sources of air contamination. A wide range of volatile organic contaminants has been observed in these closed environments, including aliphatic hydrocarbons, alcohols, aldehydes, aromatic hydrocarbons and chlorinated aliphatic components. Most of these components are biodegradable but the concentrations are usually low (mg/m^3). A biological system to remove these components needs to meet several criteria: active at low concentrations; combined removal of a wide range of organic contaminants; removal to levels below the space maximum allowable concentration (SMAC); stable activity over long periods (months); small volume and low weight; no contact between bacteria and astronauts.

  14. Aqueous secondary formation of brominated, chlorinated, and mixed halogenated pyrene in presence of halide ions.

    Science.gov (United States)

    Sankoda, Kenshi; Toda, Izumi; Sekiguchi, Kazuhiko; Nomiyama, Kei; Shinohara, Ryota

    2017-03-01

    We examined the secondary production of halogenated derivatives of polycyclic aromatic hydrocarbons (PAHs) in surface seawater. Pyrene was selected as the model compound and exposed to UV irradiation in synthetic seawater for various irradiation times. Pyrene underwent rapid photochemical reactions that produced various halogenated derivatives including 1-chloropyrene, 1-bromopyrene, three unidentified dichloropyrenes, and three unidentified bromochloropyrenes. The production of 1-chloropyrene (220-360 nM) was higher than that of 1-bromopyrene (7.3-12 nM), reflecting the high chlorine content of seawater. A pilot field survey was conducted to test the environmental implications of these results, and fresh, brackish, and seawater samples were collected in southwestern Japan. The variation in the concentration ratios between 1-chloropyrene and pyrene implied the presence of a specific source of 1-chloropyrene in coastal water, which can be partly explained by the secondary production observed in our photolysis experiments. In sum, the photochemical reactions of PAHs are a potential secondary source of halogenated PAHs, especially in marine environments heavily contaminated with PAHs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    Science.gov (United States)

    Horváth, Anikó; Futó, István; Palcsu, László

    2014-05-01

    Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

  16. 49 CFR 179.102-2 - Chlorine.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Chlorine. 179.102-2 Section 179.102-2... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must be...

  17. Stable Chlorine Isotope Fractionation

    Science.gov (United States)

    Sharp, Z.

    2006-12-01

    Chlorine isotope partitioning between different phases is not well understood. Pore fluids can have δ37Cl values as low as -8‰, with neoform sediments having strongly positive values. Most strikingly, volcanic gases have δ37Cl values that cover a range in excess of 14‰ (Barnes et al., this meeting). The large range is difficult to explain in terms of equilibrium fractionation, which, although calculated to be very large for Cl in different oxidation states, should be less than 2‰ between chloride species (Schauble et al., 2003, GCA). To address the discrepancy between Nature and theory, we have measured Cl isotope fractionation for selected equilibrium and disequilibrium experiments in order to identify mechanisms that might lead to large fractionations. 1) NaCl (s,l) NaCl (v): NaCl was sealed in an evacuated silica tube and heated at one end, causing vaporization and reprecipitation of NaCl (v) at the cool end of the tube. The fractionation is 0.2‰ at 700°C (halite-vapor) and 0.7‰ at 800°C (liquid-vapor), respectively. The larger fractionation at higher temperature may be related to equilibrium fractionation between liquid and gas vs. `stripping' of the solid in the lower T experiments. 2) Sodalite NaCl(l): Nepheline and excess NaCl were sealed in a Pt crucible at 825°C for 48 hrs producing sodalite. The measured newly-formed sodalite-NaCl fractionation is -0.2‰. 3) Volatilization of HCl: Dry inert gas was bubbled through HCl solutions and the vapor was collected in a downstream water trap. There was no fractionation for 12.4M HCl (HCl fuming) vapor at 25°C. For a 1 M boiling HCl solution, the HCl-vapor fractionation was ~9‰. The difference is probably related to the degree of dissociation in the acid, with HCl dissolved in water for the highly acidic solutions, and dissociated H3O+ and Cl- for lower concentrations. The HCl volatilization experiments are in contrast to earlier vapor-liquid experiments in NaCl-H2O system, where fractionation was

  18. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  19. CYP1A1 genetic polymorphism and polycyclic aromatic hydrocarbons on pulmonary function in the elderly: haplotype-based approach for gene-environment interaction.

    Science.gov (United States)

    Choi, Yoon-Hyeong; Kim, Jin Hee; Hong, Yun-Chul

    2013-08-29

    Lung function may be impaired by environmental pollutants not only acting alone, but working with genetic factors as well. Few epidemiologic studies have been conducted to explore the interplay of polycyclic aromatic hydrocarbons (PAHs) exposure and genetic polymorphism on lung function in the elderly. For genetic polymorphism, haplotype is considered a more informative unit than single nucleotide polymorphism markers. Therefore, we examined the role of haplotype based-CYP1A1 polymorphism in the effect of PAHs exposure on lung function in 422 participants from a community-based panel of elderly adults in Seoul, Korea. Linear mixed effect models were fit to evaluate the association of PAH exposure markers (urinary 1-hydroxypyrene and 2-naphthol) with FVC, FEV₁, FEV₁/FVC, and FEF₂₅₋₇₅, and then the interaction with CYP1A1 haplotype constructed from three single nucleotide polymorphisms of the gene (rs4646421/rs4646422/rs1048943). Urinary 1-hydroxypyrene levels were inversely associated with FEV₁/FVC (ppolymorphisms on lung functions. Our findings suggest that PAH exposure producing 1-hydroxypyrene as a metabolite compromises lung function in the elderly, and that haplotype-based CYP1A1 polymorphism modifies the risk. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Reductive dechlorination of chlorinated ethenes by iron metal and iron sulfide minerals

    Energy Technology Data Exchange (ETDEWEB)

    Sivavec, T.M.; Horney, D.P.; Baghel, S.S. [GE Corporate Research and Development, Schenectady, NY (United States)

    1995-12-31

    Reduced forms of iron and sulfur, such as Fe(II), iron(II) sulfide and hydrogen sulfide, are abundant natural reductants in anaerobic soils and sediments. Redox reactions between these reductants and organic pollutants are often greatly accelerated in natural systems because of microbial mediation or because the electron transfer is mediated by the cycling of Fe(II)/Fe(III). For example, recent studies have shown that surface-bound, reduced iron species play the important role of electron transfer mediator in reductions promoted by iron-reducing bacteria. It has been postulated that the reduction of chlorinated hydrocarbons by iron metal may occur by a reaction of surface-bound Fe(II) at the iron metal-water interface. The surface-bound Fe(II) species at the passive oxide-water interface may serve as mediator for the transfer of electrons from Fe{sup 0} to adsorbed chlorinated hydrocarbon. Fast reduction rates for chlorinated hydrocarbons observed in this system may be attributed to the facile regeneration of reducing surface Fe(II) species due to the close proximity of the bulk reductant (Fe{sup 0}) to the electron carrier, surface-bound Fe(II). Evidence in support of this proposed mechanism is presented.

  1. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What if my system uses chloramines... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system must...

  2. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What if my system uses chloramines... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must also...

  3. Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

    Directory of Open Access Journals (Sweden)

    Adeline, S. Y. Ting

    2009-01-01

    Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

  4. Removal of hazardous chlorinated VOCs from aqueous solutions using novel ZSM-5 loaded PDMS/PVDF composite membrane consisting of three hydrophobic layers.

    Science.gov (United States)

    Ramaiah, K Pattabhi; Satyasri, D; Sridhar, S; Krishnaiah, A

    2013-10-15

    Hydrophobic polymer possesses significant potential for selective separation of volatile organic compounds (VOCs) from their aqueous solutions by pervaporation (PV). In the present study mixed matrix hydrophobic membranes of polydimethylsiloxane (PDMS) supported on polyvinylidenefluoride (PVDF) substrate were synthesized by incorporating hydrophobic inorganic ZSM-5 filler. The indigenous membranes were crosslinked with tetraethylorthosilicate (TEOS) for the extraction of volatile chlorinated hydrocarbons such as dichloromethane (DCM), trichloromethane (TCM), 1,2-dichloroethane (DCE), and 1,1,2,2-tetrachloroethane (TeCE), which pose serious environment threat and health hazard. Thermal stability, crosslinking, crystallinity, surface morphology and swelling characteristics of the indigenously developed membranes were determined by TGA, FTIR, XRD, SEM and sorption studies, respectively. Effect of operating parameters such as feed composition and filler concentration on separation performance in terms of flux and selectivity were determined. Flux of DCM, TCM, DCE and TeCE was found to be 0.166, 0.146, 0.141 and 0.06 kg m(-2)h(-1) with selectivity of 541, 1068, 917 and 15,000, respectively, for 20% ZSM-5 filled PDMS membrane for aqueous feeds containing 1.33% (w/v) DCM, 0.8% (w/v) TCM, 0.84% (w/v) DCE and 0.28% (w/v) TeCE in water. The membrane exhibited considerable feasibility for scale-up with significant potential for removal of hazardous chlorinated VOCs from aqueous solutions. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. A CASE STUDY OF CHLORINE TRANSPORT AND FATE FOLLOWING A LARGE ACCIDENTAL RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.; Werth, D.; Whiteside, M.; Chen, K.; Mazzola, C.

    2012-08-01

    A train derailment that occurred in Graniteville, South Carolina during the early morning hours of 06 January, 2005 resulted in the prompt release of approximately 60 tons of chlorine to the environment. Comprehensive modeling of the transport and fate of this release was performed including the characterization of the initial three-phased chlorine release, a detailed determination of the local atmospheric conditions acting to generate, disperse, and deplete the chlorine vapor cloud, the establishment of physical exchange mechanisms between the airborne vapor and local surface waters, and local aquatic dilution and mixing.

  6. Chlorine Abundances in Martian Meteorites

    Science.gov (United States)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  7. Remobilization of polycyclic aromatic hydrocarbons and organic matter in seawater during sediment resuspension experiments from a polluted coastal environment: Insights from Toulon Bay (France).

    Science.gov (United States)

    Guigue, Catherine; Tedetti, Marc; Dang, Duc Huy; Mullot, Jean-Ulrich; Garnier, Cédric; Goutx, Madeleine

    2017-10-01

    Polycyclic aromatic hydrocarbons (PAHs) and organic matter contents were measured in seawater during resuspension experiments using sediments collected from Toulon Bay (Northwestern Mediterranean Sea, France). The studied sediments were very highly contaminated in PAHs, especially in 4-ring compounds emitted from combustion processes. The sediments used for resuspension experiments were collected at 0-2 cm (diagenetically new organic matter, OM) and 30-32 cm depths (diagenetically transformed OM). They were both mostly composed of fine particles (sediments led to an increase in concentrations of dissolved Σ34 PAHs, dissolved organic carbon (DOC) and dissolved humic- and tryptophan-like fluorophores in seawater up to 10-, 1.3-, 4.4- and 5.7-fold, respectively. The remobilization in seawater was higher for 4-6 ring PAHs, especially benzo(g,h,i)perylene, whose concentration exceeded the threshold values of the European Water Framework Directive. This noted the potential harmful effects of sediment resuspension on marine biota. From these sediment resuspension experiments, we determined OC-normalized partition coefficients of PAHs between sediment and water (Koc) and found that during such events, the transfer of PAHs from sediment particles to seawater was lower than that predicted from octanol-water partition coefficients (Kow) (i.e., measured Koc > Koc predicted from Kow). The results confirmed the sequestration role of sedimentary OC quality and grain size on PAHs; the OM diagenetic state seemed to impact the partition process but in a relatively minor way. Furthermore, differences were observed between 2-4 ring and 5-6 ring PAHs, with the latter displaying a relatively higher mobility towards seawater. These differences may be explained by the distribution of these two PAH pools within different OM moieties, such as humic substances and black carbon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Recovery of Co, Ni, Mo, and V from unroasted spent hydrorefining catalysts by selective chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Gaballah, I.; Djona, M. (Inst. National Polytechnique de Lorraine, Vandoeuvre (France))

    1995-02-01

    Spent hydrorefining catalysts may contain 4 to 6% of CoO and/or NiO, 8 to 16% of MoO[sub 3], and up to 10% of V[sub 2]O[sub 5], generally supported by alumina. They also contain up to 25% of carbon, hydrocarbons, and sulfur. Selective chlorination of raw, unroasted samples with Cl[sub 2] + air, Cl[sub 2] + N[sub 2], and Cl[sub 2] + CO + N[sub 2] gas mixtures have been investigated for the recovery of valuable elements. The fastest chlorination kinetics are obtained using the Cl[sub 2] + CO + N[sub 2] gas mixture, followed by Cl[sub 2] + N[sub 2]. The best selective chlorination of spent hydrorefining catalysts is obtained using a Cl[sub 2] + air gas mixture. At temperatures lower than 600 C, it is possible to recover more than 90% of the Ni and Co, about 99% of the Mo, and up to 75% of the V compounds. Cobalt and Nickel chlorides are extracted from the chlorination residues by their dissolution with water. Molybdenum and vanadium chlorides and/or oxychlorides are recovered by selective condensation from the vapor phase. The chlorination of the catalyst support, Al[sub 2]O[sub 3], can be limited to less than about 6%. A flow sheet is proposed.

  9. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    that thraustochytrids have the capability to utilize a wide range of organic nitrogen and carbon compounds for their nutrition. However, the capability of these protists to degrade hydrocarbons has not been examined so far. Hydrocarbons occur in seawater either... chromatography. (1) Gravimetry: Tarballs were extracted from experimental flasks with 10 ml of carbon tetrachloride, the extract transferred to pre- weighed Petri dish and the solvent allowed to RAIKAR et al.: THRAUSTOCHYTRID PROTISTS DEGRADE HYDROCARBONS...

  10. Chlorination Revisited: Does Cl- Serve as a Catalyst in the Chlorination of Phenols?

    Science.gov (United States)

    Lau, Stephanie S; Abraham, Sonali M; Roberts, A Lynn

    2016-12-20

    The aqueous chlorination of (chloro)phenols is one of the best-studied reactions in the environmental literature. Previous researchers have attributed these reactions to two chlorine species: HOCl (at circum-neutral and high pH) and H2OCl+ (at low pH). In this study, we seek to examine the roles that two largely overlooked chlorine species, Cl2 and Cl2O, may play in the chlorination of (chloro)phenols. Solution pH, chloride concentration, and chlorine dose were systematically varied in order to assess the importance of different chlorine species as chlorinating agents. Our findings indicate that chlorination rates at pH chlorine dose representative of drinking water treatment, Cl2O is predicted to have at best a minor impact on chlorination reactions, whereas Cl2 may contribute more than 80% to the overall chlorination rate depending on the (chloro)phenol identity and chloride concentration. While it is not possible to preclude H2OCl+ as a chlorinating agent, we were able to model our low-pH data by considering Cl2 only. Even traces of chloride can generate sufficient Cl2 to influence chlorination kinetics, highlighting the role of chloride as a catalyst in chlorination reactions.

  11. Polydopamine-reinforced magnetization of zeolitic imidazolate framework ZIF-7 for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from the air-water environment.

    Science.gov (United States)

    Zhang, Suling; Yao, Weixuan; Ying, Jianbo; Zhao, Hongting

    2016-06-24

    Zeolitic imidazolate frameworks (ZIFs) consist of metal nodes connected to imidazolate linkers, having both the properties of metal-organic frameworks (MOFs) and inorganic zeolites, such as controllable pore sizes, high porosity and surface areas, as well as exceptional thermal and chemical stability, thereby making them a class of attractive materials for diverse analytical applications. In this study, we reported a facile magnetization process of ZIF-7 (zinc benzimidazolate) for simultaneous magnetic extraction of polycyclic aromatic hydrocarbons (PAHs) by simply mixing ZIF-7 and polydopamine (PDA)-coated Fe3O4 nanoparticles (PDA@Fe3O4) in solutions. Functional groups (-OH and -NH2), provided by PDA as a highly efficient molecular linker, could attract and anchor ZIF-7 through noncovalent adsorption and covalent cross-link interactions, thereby promoting the complete magnetization of ZIFs and enhancing their stability and reusability. The bridging ligand benzimidazolate, could be bonded with PAHs because of its high surface area, large pores, accessible coordinative unsaturated sites (π-complexation), and π-π stacking action. This ZIF-based magnetic solid-phase extraction (SPE), coupled with gas chromatography/tandem mass spectrometry (GC/MS), was further evaluated for analysis of PAHs from rainwater and air samples of particulate matter less than 2.5μm in diameter (PM2.5). The main effective parameters, including ionic strength, solution pH, extraction time, desorption solvent and desorption time, were investigated, respectively. Under optimized conditions, the developed method based on Fe3O4@PDA/ZIF-7 gave detection limits of 0.71-5.79ng/L, and quantification limits of 2.50-19.2ng/L for PAHs, respectively. The relative standard deviations for intra-day and inter-day analyses were in the range of 3.1-9.1% and 6.1-12.7%, respectively. The PAHs founded in PM2.5 were in the range of 0.40-6.79ng/m(3). Good recoveries (>82%) with low relative standard deviations

  12. 40 CFR 144.21 - Existing Class I, II (except enhanced recovery and hydrocarbon storage) and III wells.

    Science.gov (United States)

    2010-07-01

    ... recovery and hydrocarbon storage) and III wells. 144.21 Section 144.21 Protection of Environment... hydrocarbon storage) and III wells. (a) An existing Class I, II (except enhanced recovery and hydrocarbon... decision; or (9) For Class II wells (except enhanced recovery and hydrocarbon storage), five years after...

  13. Fogging of Chlorine-Based Sporicidal Liquids for the ...

    Science.gov (United States)

    Report The purpose of this investigation was to determine the sporicidal efficacy of a fogging technology using chlorine-based sporicidal liquids for inactivating bacterial spores (Bacillus [B.] atrophaeus, a surrogate for B. anthracis) in an office or indoor environment. The use of fogging technology to disseminate sporicidal solutions via microscopic droplets has the potential to be a less arduous, more economical volumetric decontamination alternative to fumigation.

  14. Aqueous chlorination of acebutolol: kinetics, transformation by-products, and mechanism.

    Science.gov (United States)

    Khalit, Wan Nor Adira Wan; Tay, Kheng Soo

    2016-02-01

    This study investigated the reaction kinetics and the transformation by-products of acebutolol during aqueous chlorination. Acebutolol is one of the commonly used β-blockers for the treatment of cardiovascular diseases. It has been frequently detected in the aquatic environment. In the kinetics study, the second-order rate constant for the reaction between acebutolol and chlorine (k app) was determined at 25 ± 0.1 °C. The degradation of acebutolol by free available chlorine was highly pH dependence. When the pH increased from 6 to 8, it was found that the k app for the reaction between acebutolol and free available chlorine was increased from 1.68 to 11.2 M(-1) min(-1). By comparing with the reported k app values, the reactivity of acebutolol toward free available chlorine was found to be higher than atenolol and metoprolol but lower than nadolol and propranolol. Characterization of the transformation by-products formed during the chlorination of acebutolol was carried out using liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry. Seven major transformation by-products were identified. These transformation by-products were mainly formed through dealkylation, hydroxylation, chlorination, and oxidation reactions.

  15. The effect of chlorine and combined chlorine/UV treatment on coliphages in drinking water disinfection.

    Science.gov (United States)

    Zyara, Alyaa M; Torvinen, Eila; Veijalainen, Anna-Maria; Heinonen-Tanski, Helvi

    2016-08-01

    Chlorine disinfection is a globally used method to ensure the safety of drinking water. However, it has not always been successful against viruses and, therefore, it is important to find new methods to disinfect water. Seventeen different coliphages were isolated from the treated municipal wastewater. These coliphages and MS2 were treated with different dosages of chlorine in drinking water, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method.

  16. UV/chlorine process for ammonia removal and disinfection by-product reduction: comparison with chlorination.

    Science.gov (United States)

    Zhang, Xinran; Li, Weiguang; Blatchley, Ernest R; Wang, Xiaoju; Ren, Pengfei

    2015-01-01

    The combined application of UV irradiation at 254 nm and chlorination (UV/chlorine process) was investigated for ammonia removal in water treatment. The UV/chlorine process led to higher ammonia removal with less chlorine demand, as compared to breakpoint chlorination. Chlorination of NH₃ led to NH₂Cl formation in the first step. The photolysis of NH₂Cl and radical- mediated oxidation of ammonia appeared to represent the main pathways for ammonia removal. The trivalent nitrogen of ammonia was oxidized, presumably by reactions with aminyl radicals and chlorine radicals. Measured products included NO₃⁻and NO₂⁻; it is likely that N₂ and N₂O were also generated. In addition, UV irradiation appeared to have altered the reactivity of NOM toward free chlorine. The UV/chlorine process had lower chlorine demand, less C-DBPs (THMs and HAAs), but more HANs than chlorination. These results indicate that the UV/chlorine process could represent an alternative to conventional breakpoint chlorination for ammonia-containing water, with several advantages in terms of simplicity, short reaction time, and reduced chemical dosage.

  17. Hydrocarbon Spectral Database

    Science.gov (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  18. Plant hydrocarbon recovery process

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-01-26

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

  19. Coal desulfurization by aqueous chlorination

    Science.gov (United States)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K. (Inventor)

    1982-01-01

    A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 C to 500 C to form a non-caking, low-sulfur coal product.

  20. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  1. Characterization of pharmaceuticals and personal care products as N-nitrosodimethylamine precursors during disinfection processes using free chlorine and chlorine dioxide.

    Science.gov (United States)

    Zhang, Ai; Li, Yongmei; Song, Yun; Lv, Juan; Yang, Juan

    2014-07-15

    The worldwide detection of pharmaceuticals and personal care products (PPCPs) in aquatic environment and drinking water has caused wide concern in recent years. The possibility for concurrent formation of N-nitrosodimethylamine (NDMA) during disinfection has become another significant concern for water quality. This study demonstrates that a group of PPCPs containing amine groups can serve as NDMA precursors during free chlorine or chlorine dioxide (ClO2) chlorination processes. Selected PPCPs after screening by NDMA yield were further investigated for NDMA formation conditions. High disinfectant dose and initial PPCP concentration resulted in relatively high NDMA formation potential. Linear kinetic models were developed for NDMA formation during chlorination of selected PPCPs. Although the PPCP precursors were removed significantly during chlorination, they were not completely mineralized based on the total organic carbon (TOC) loss. The existence of another possible pathway for direct formation of NDMA from tertiary amine during chlorination was indicated, in which dimethylamine (DMA) was not involved. It is recommended to control the initial PPCP concentrations prior to disinfection and to shorten the contact time to reduce the NDMA formation. ClO2 is suggested to be a proper disinfectant in order to reduce the NDMA formation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Measuring the EUV-induced contamination rates of TiO2-capped multilayer optics by anticipated production-environment hydrocarbons

    Science.gov (United States)

    Hill, S. B.; Faradzhev, N. S.; Tarrio, C. S.; Lucatorto, T. B.; Bartynski, R. A.; Yakshinskiy, B. V.; Madey, T. E.

    2009-03-01

    The primary, publicly reported cause of optic degradation in pre-production extreme-ultraviolet (EUV) lithography systems is carbon deposition. This results when volatile organics adsorb onto optic surfaces and then are cracked by EUV-induced reactions. Hence the deposition rate depends on the adsorption-desorption kinetics of the molecule-surface system as well as the basic photon-stimulated reaction rates, both of which may vary significantly for different organic species. The goal of our ongoing optics-contamination program is to estimate the contamination rate of species expected in the tool environment by exposing samples to in-band 13.5 nm light from our synchrotron in the presence of fixed partial pressures of admitted gases. Here we report preliminary results of contamination rates on TiO2-capped samples for species observed in resist-outgassing measurements (benzene, isobutene, toluene and tert-butylbenzene) in the pressure range (10-6 to 10-4) Pa which all display an unexpected logarithmic dependence on pressure. This scaling is in agreement with previous EUV exposures of other species at NIST as well as independent measurements of coverage performed at Rutgers University. These results are consistent with a molecular desorption energy that decreases with coverage due to molecular interactions (Temkin model). Use of the proper scaling law is critical when estimating optic lifetimes by extrapolating over the 3-to-6 orders of magnitude between accelerated-testing and tool-environment partial pressures.

  3. Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

    KAUST Repository

    Wadsworth, Andrew

    2017-06-01

    With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

  4. Chlorination or monochloramination: Balancing the regulated trihalomethane formation and microbial inactivation in marine aquaculture waters

    KAUST Repository

    Sanawar, Huma

    2017-08-15

    Disinfection methods like chlorination are increasingly used to sanitize the water, equipment, tools and surfaces in aquaculture facilities. This is to improve water quality, and to maintain a hygienic environment for the well-being of aquatic organisms. However, chlorination can result in formation of regulated disinfection byproducts (DBPs) that can be carcinogenic and toxic. This study aims to evaluate if an optimal balance can be achieved between minimal regulated DBP formation and effective microbial inactivation with either chlorination or monochloramination for application in the Red Sea aquaculture waters. Upon chlorination, the concentration of total trihalomethanes (THMs), primarily bromoform, exceeded the regulatory limit of 80μg/L even at the lowest tested concentration of chlorine (1mg/L) and contact time (1h). Comparatively, regulated THMs concentration was only detectable at 30μg/L level in one of the three sets of monochloraminated marine aquaculture waters. The average log reduction of antibiotic-resistant bacteria (ARB) by chlorine ranged from 2.3-log to 3.2-log with different contact time. The average log reduction of ARB by monochloramine was comparatively lower at 1.9 to 2.9-log. Although viable Staphylococcus aureus was recovered from monochloraminated samples as opposed to chlorinated samples, the abundance of S. aureus was not high enough to result in any significant microbial risks. Both chlorination and monochloramination did not provide any significant improvement in the reduction of antibiotic resistance genes (ARGs). This study demonstrates that a systematic evaluation is needed to determine the optimal disinfectant required to balance both microbial and chemical risks. Compared to chlorine, monochloramine may be a more appropriate disinfection strategy for the treatment of aquaculture effluents prior to discharge or for recirculatory use in the aquaculture facility.

  5. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Microorganisms play diverse roles in biotechnology; one of such roles is ... hydrocarbon polluted sites using vapour phase transfer technique with ... The purified fungal isolates were identified based on .... Cytochrome P450 monooxygenase systems which incorporate molecular .... substrate specificity on marine bacteria.

  6. Support to the identification of potential risks for the environment and human health arising from hydrocarbons operations involving hydraulic fracturing in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Broomfield, L.; Lelland, A.

    2012-09-15

    The potential risks for the environment and human health arising from shale gas production (hydraulic fracturing) in Europe are assessed. As readily accessible oil and gas reserves are becoming progressively limited, the energy supply industry is turning more to unconventional reserves, which were previously too complex or too expensive to extract, like shale gas. There are significant shale gas reserves in Europe. Permission is being sought in many EU Member States for exploratory works and to bring forward projects for hydraulic fracturing and extraction of shale gas. As with any drilling and extraction process, shale gas extraction brings environmental and health risks which need to be understood and addressed. CE Delft conducted the legal assessment on shale gas related EU legislation. Gaps and uncertainties have been addressed, but no real risks within the legislation have been discovered. A large part of the shale gas related legislation is part of the individual member states legislation and not directly addressed by EU legislation.

  7. Efficacy of chlorine dioxide mouthwash against halitosis

    Science.gov (United States)

    Bestari, M. D.; Sunarto, H.; Kemal, Y.

    2017-08-01

    To ascertain the effectiveness of using chlorine dioxide mouthwash in addressing halitosis. Forty people were divided equally into the test group (required to gargle with mouthwash containing chlorine dioxide) and the control group (required to gargle with aquadest). The volatile sulfur compound (VSC) and organoleptic scores were measured before gargling and 30 min, 2 h, 4 h, and 6 h after. The Wilcoxon test analysis showed a significant difference (pChlorine dioxide mouthwash is effective in addressing halitosis.

  8. Chlorine Inactivation of Spores of Encephalitozoon spp.

    OpenAIRE

    Johnson, C. H.; Marshall, M. M.; DeMaria, L. A.; Moffet, J. M.; Korich, D. G.

    2003-01-01

    This report is an extension of a preliminary investigation on the use of chlorine to inactivate spores of Encephalitozoon intestinalis and to investigate the effect of chlorine on two other species, E cuniculi and E. hellem, associated with human infection. The 50% tissue culture infective doses of these three species were also determined. On the basis of the results obtained, it appears that chlorination of water is an effective means of controlling spores of these organisms in the aquatic e...

  9. Novel Photocatalytic Reactor Development for Removal of Hydrocarbons from Water

    Directory of Open Access Journals (Sweden)

    Morgan Adams

    2008-01-01

    Full Text Available Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the removal of hydrocarbons from two waste effluent sources. Two reactor concepts were considered: a simple flat plate immobilised film unit, and a new rotating drum photocatalytic reactor. Both units proved to be effective in removing residual hydrocarbons from the effluent with the drum reactor reducing the hydrocarbon content by 90% under 10 minutes.

  10. Sterilization of hydrogen peroxide resistant bacterial spores with stabilized chlorine dioxide.

    Science.gov (United States)

    Friedline, Anthony; Zachariah, Malcolm; Middaugh, Amy; Heiser, Matt; Khanna, Neeraj; Vaishampayan, Parag; Rice, Charles V

    2015-01-01

    Bacillus pumilus SAFR-032 spores isolated from a clean room environment are known to exhibit enhanced resistance to peroxide, desiccation, UV radiation and chemical disinfection than other spore-forming bacteria. The survival of B. pumilus SAFR-032 spores to standard clean room sterilization practices requires development of more stringent disinfection agents. Here, we report the effects of a stabilized chlorine dioxide-based biocidal agent against spores of B. pumilus SAFR-032 and Bacillus subtilis ATCC 6051. Viability was determined via CFU measurement after exposure. Chlorine dioxide demonstrated efficacy towards sterilization of spores of B. pumilus SAFR-032 equivalent or better than exposure to hydrogen peroxide. These results indicate efficacy of chlorine dioxide delivered through a stabilized chlorine dioxide product as a means of sterilization of peroxide- and UV-resistant spores.

  11. A COMPREHENSIVE ANALYSIS OF CHLORINE TRANSPORT AND FATE FOLLOWING A LARGE ENVIRONMENTAL RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.; Werth, D.; Chen, K.; Whiteside, M.; Mazzola, C.

    2011-05-10

    A train derailment occurred in Graniteville, South Carolina during the early morning of January 6, 2005, and resulted in the release of a large amount of cryogenic pressurized liquid chlorine to the environment in a short time period. A comprehensive evaluation of the transport and fate of the released chlorine was performed, accounting for dilution, diffusion, transport and deposition into the local environment. This involved the characterization of a three-phased chlorine release, a detailed determination of local atmospheric mechanisms acting on the released chlorine, the establishment of atmospheric-hydrological physical exchange mechanisms, and aquatic dilution and mixing. This presentation will provide an overview of the models used in determining the total air-to-water mass transfer estimated to have occurred as a result of the roughly 60 tons of chlorine released into the atmosphere from the train derailment. The assumptions used in the modeling effort will be addressed, along with a comparison with available observational data to validate the model results. Overall, model-estimated chlorine concentrations in the airborne plume compare well with human and animal exposure data collected in the days after the derailment.

  12. The chlorination of cyclopentanone and cyclohexanone

    NARCIS (Netherlands)

    Maatman, Hendrik

    1980-01-01

    In this thesis the results of an investigation of the chlorination of cyclopentanone and cyclohexanone in the solvent carbontetrachloride and catalyzed by hydrogen chloride are described. ... Zie: Summary

  13. Potassium chloride production by microcline chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, San Luis (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina)

    2015-08-10

    Highlights: • Use of chlorination for the KCl production. • The reagents used were microcline, hydromagnesite and chlorine. • Isothermal and non-isothermal assays were performed in Cl{sub 2}–N{sub 2} mixture. • The chlorination generated KCl at 700 °C. • The chlorination products promote KCl formation. - Abstract: The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated.

  14. Hydrocarbon toxicity: A review.

    Science.gov (United States)

    Tormoehlen, L M; Tekulve, K J; Nañagas, K A

    2014-06-01

    Clinical effects of hydrocarbon exposure have been reported since 1897. These substances are ubiquitous, and their exposures are common. The specific hydrocarbon and route of exposure will determine the clinical effect, and an understanding of this is helpful in the care of the hydrocarbon-exposed patient. To complete a comprehensive review of the literature on hydrocarbon toxicity and summarize the findings. Relevant literature was identified through searches of Medline (PubMed/OVID) and Cochrane Library databases (inclusive of years 1975-2013), as well as from multiple toxicology textbooks. Bibliographies of the identified articles were also reviewed. Search terms included combinations of the following: hydrocarbons, inhalants, encephalopathy, coma, cognitive deficits, inhalant abuse, huffing, sudden sniffing death, toluene, renal tubular acidosis, metabolic acidosis, arrhythmia, dermatitis, and aspiration pneumonitis. All pertinent clinical trials, observational studies, and case reports relevant to hydrocarbon exposure and published in English were reviewed. Chronic, occupational hydrocarbon toxicity was not included. Exposure to hydrocarbons occurs through one of the following routes: inhalation, ingestion with or without aspiration, or dermal exposure. Inhalational abuse is associated with central nervous system depression, metabolic acidosis, and arrhythmia. The exact mechanism of the CNS depression is unknown, but experimental evidence suggests effects on NMDA, dopamine, and GABA receptors. Chronic toluene inhalation causes a non-anion gap metabolic acidosis associated with hypokalemia. Halogenated hydrocarbon abuse can cause a fatal malignant arrhythmia, termed "sudden sniffing death". Individuals who regularly abuse hydrocarbons are more likely to be polysubstance users, exhibit criminal or violent behavior, and develop memory and other cognitive deficits. Heavy, long-term use results in cerebellar dysfunction, encephalopathy, weakness, and dementia

  15. Les hydrocarbures aromatiques polycycliques dans l'environnement. Première partie. Propriété, origines, devenir Polycyclic Aromatic Hydrocarbons in the Environment. Part One. Properties, Origins, Fates

    Directory of Open Access Journals (Sweden)

    Bouchez M.

    2006-11-01

    Full Text Available Les hydrocarbures aromatiques polycycliques (HAP sont des contaminants produits notamment dans les processus de combustion. Leur caractère ubiquiste et leur génotoxicité sont à l'origine d'une activité de recherche importante. Après avoir présenté les structures chimiques et les propriétés physico-chimiques et biologiques principales de ces composés, on résume les connaissances actuelles concernant leur présence dans l'environnement. Les critères géochimiques de leurs différentes origines pyrolytique, diagénétique ou pétrolière, sont exposés. On examine la contribution des différentes sources d'émission, le transport et la diffusion dans l'environnement de ces composés, ainsi que les modifications qu'ils subissent et leur sort ultime. La distribution qualitative et quantitative des HAP de combustion dans les sols d'environnements variés est présentée. Polycyclic aromatic hydrocarbons (PAH are environmental contaminants produced in particular in combustion processes. As a consequence of their genotoxicity and ubiquity, they are the subject of an important research activity. After a presentation of the chemical structures and of the main physico-chemical and biological properties of these compounds, the current knowledge regarding their presence in the environment is summarized. The geochernical criteria of the different,origins, pyrolytic, diagenetic and petroleum of PAH are presented. The respective contributions of their various emission sources are discussed , as well as the transfer and diffusion in the environment, the modifications undergone and the ultimate fate of these compounds. The qualitative and quantitative distribution of combustion PAH in soils in different environmental situations is presented.

  16. 40 CFR 180.526 - Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons; tolerances for residues. 180.526 Section 180.526 Protection of Environment ENVIRONMENTAL... FOOD Specific Tolerances § 180.526 Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues. (a) General. Synthetic isoparaffinic petroleum hydrocarbons complying with 21 CFR 172.882 (a) and...

  17. 40 CFR 52.269 - Control strategy and regulations: Photochemical oxidants (hydrocarbons) and carbon monoxide.

    Science.gov (United States)

    2010-07-01

    ...: Photochemical oxidants (hydrocarbons) and carbon monoxide. 52.269 Section 52.269 Protection of Environment... PLANS California § 52.269 Control strategy and regulations: Photochemical oxidants (hydrocarbons) and... provide for attainment and maintenance of the national standards for photochemical oxidants (hydrocarbons...

  18. 40 CFR 144.22 - Existing Class II enhanced recovery and hydrocarbon storage wells.

    Science.gov (United States)

    2010-07-01

    ... and hydrocarbon storage wells. 144.22 Section 144.22 Protection of Environment ENVIRONMENTAL... of Underground Injection by Rule § 144.22 Existing Class II enhanced recovery and hydrocarbon storage wells. (a) An existing Class II enhanced recovery or hydrocarbon storage injection well is authorized by...

  19. Organic amendment optimization for treatment of hydrocarbon ...

    African Journals Online (AJOL)

    Jane

    2010-10-18

    Oct 18, 2010 ... de hidrocarburos en el suelo de playas de presa agua de mina. Texistepec, Veracruz. Tesis de Licenciatura. División Académica de. Ciencias Biológicas. Universidad Juárez Autónoma de Tabasco. p. 51. Atlas RM (1986). Biodegradation of hydrocarbons in the environment,. In: Enviromental biotechnology ...

  20. Remediation of petroleum hydrocarbon polluted systems: Exploiting ...

    African Journals Online (AJOL)

    The irrepressible quest for a cheap source of energy to meet the extensive global industrialization demand has expanded the frontiers of petroleum hydrocarbon exploration. These exploration activities amongst others often result in pollution of the environment, thus creating serious imbalance in the biotic and abiotic ...

  1. Analysis of short-chain chlorinated paraffins: a discussion paper.

    Science.gov (United States)

    Pellizzato, Francesca; Ricci, Marina; Held, Andrea; Emons, Hendrik

    2007-09-01

    Short-chain chlorinated paraffins are a class of organic compounds widely used in many industrial applications, extensively diffused into the environment, persistent, bioaccumulative, and toxic towards aquatic organisms. However, their study and monitoring in the environment are still limited. Because of the enormous number of positional isomers that characterise their mixtures, the analysis of this class of pollutants is very difficult to perform. Beside this, the lack of certified reference materials poses a problem for the assessment of the quality assurance/quality control of any analytical procedure. At present, the scientific community does not agree on any analytical reference method, although the monitoring of short-chain chlorinated paraffins has already started in order to comply with the Water Framework Directive of the European Union on water quality. In this paper the regulatory framework, in which chlorinated paraffins are included, and the status concerning their determination are summarized. The main analytical difficulties still existing are discussed, and the definition of a method-defined parameter as well as the development of a standardised method are suggested as a way to obtain comparable monitoring data.

  2. Chlorine dioxide and by-products in water distribution systems

    OpenAIRE

    Ferreira, Francisco Cardoso

    1991-01-01

    Chlorine dioxide is used as both a pre-oxidant and/or a post-disinfectant in several water treatment plants in the United States. Chlorine dioxide is associated with its byproducts chlorite and chlorate. Chlorine dioxide, chlorine, chlori te and chlorate were sampled in four distribution systems where chlorine dioxide is used for disinfection purposes: Charleston, WV, Columbus, GA, New Castle, PA, and Skagit, WA. The fate of chlorine dioxide and its by-products in dist...

  3. Chlorine gas sensors using one-dimensional tellurium nanostructures.

    Science.gov (United States)

    Sen, Shashwati; Sharma, Madhvi; Kumar, Vivek; Muthe, K P; Satyam, P V; Bhatta, Umananda M; Roy, M; Gaur, N K; Gupta, S K; Yakhmi, J V

    2009-03-15

    Tellurium nanotubes have been grown by physical vapor deposition under inert environment at atmospheric pressure as well as under vacuum conditions. Different techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and optical absorption have been utilized for characterization of grown structures. Films prepared using both types of tellurium nanotubes were characterized for sensitivity to oxidizing and reducing gases and it was found that the relative response to gases depends on the microstructure. Nanotubes prepared at atmospheric pressure (of argon) showed high sensitivity and better selectivity to chlorine gas. Impedance spectroscopy studies showed that the response to chlorine is mainly contributed by grain boundaries and is therefore enhanced for nanotubes prepared under argon atmosphere.

  4. Anaerobic biodegradability and toxicity of wastewaters from chlorine and total chlorine-free bleaching of eucalyptus kraft pulps.

    NARCIS (Netherlands)

    Vidal, G.; Soto, M.; Field, J.; Mendez-Pampin, R.; Lema, J.M.

    1997-01-01

    Chlorine bleaching effluents are problematic for anaerobic wastewater treatment due to their high methanogenic toxicity and low biodegradability. Presently, alternative bleaching processes are being introduced, such as elemental chlorine-free (ECF) and total chlorine-free (TCF) bleaching. The

  5. Ecotoxicologically based environmental risk limits for several volatile aliphatic hydrocarbons

    NARCIS (Netherlands)

    Jong FMW de; Posthuma-Doodeman CJAM; Verbruggen EMJ; SEC

    2007-01-01

    This report describes ecotoxicological environmental risk limits derived for a number of volatile aliphatic hydrocarbons. On the basis of evaluated literature, the National Institute for Public Health and the Environment (RIVM) proposes ecotoxicological environmental risk limits for these compounds

  6. Atmospheric oxidation of hydrocarbons: Formation of hydroperoxides and peroxyacids

    Science.gov (United States)

    Hanst, Philip L.; Gay, Bruch W.

    Hydrocarbons at ppm levels in air have been oxidized in the absence of nitrogen oxides. Chlorine atoms served as initiators of the oxidations. Infrared analysis showed alkyl hydroperoxides to be formed early in the oxidation sequences. Aldehydes and ketones were also formed, followed by the appearance of peroxyacids. Peroxyacetic acid was found to be an especially stable reaction product. Laboratory rate data and recent atmospheric measurements of NO, NO 2 and HO 2 indicate that hydroperoxides and peroxyacids are also formed in the real atmosphere.

  7. Bioaccumulation factors for chlorinated benzenes, chlorinated butadienes and hexachloroethane

    Energy Technology Data Exchange (ETDEWEB)

    Burkhard, L.P. [Environmental Protection Agency, Duluth, MN (United States). National Health and Environmental Effects Research Lab.; Sheedy, B.R. [AScI Corp., Duluth, MN (United States); McCauley, D.J.; DeGraeve, G.M. [Battelle-Great Lakes Environmental Center, Traverse City, MI (United States)

    1997-08-01

    A field study was performed that measured bioaccumulation factors (BAFs) for chlorinated benzenes, chlorinated butadienes, and hexachloroethane in four species, Fundulus heteroclitus (mummichog), Callinectes sapidus (blue crabs), Brevoortia patronus (gulf menhaden), and Micropoganias undulatus (Atlantic croaker). The measured BAFs were not significantly different among the fishes. The measured BAFs for the C. sapidus were in good agreement with those measured for the fishes except for hexachloroethane (HCE), E- and Z-1,1,2,3,4-pentachlorobuta-1,3-diene (E-and Z-PeCBD), and hexachlorobuta-1,3-diene (HCBD). Their measured BAFs were approximately an order of magnitude smaller than those measured for the fishes. The measured BAFs were also in good agreement with BAFs reported/derived from the literature and to BAFs predicted using two methods of the Environmental Protection Agency (EPA) except for HCE, E- and Z-PeCBD, and HCBD in the C. sapidus. These BAFs were much smaller than the reported/derived and predicted BAFs. The smaller BAFs for HCE, E- and Z-PeCBD, and HCBD were consistent with the metabolism abilities for the C. sapidus, and metabolism processes are believed to be the cause for the smaller BAFs. The predicted BAFs were within a factor of five of the measured BAFs for 90% (n = 48) and 94% (n = 32) using the two methods of the EPA.

  8. Selection of Microbes and Conditions that Induced Bio-Cracking of Branched Hydrocarbon Squalane

    OpenAIRE

    Gailiūtė, I.; Grigiškis, S.; Žėkaitė, G.; Čipinytė, V.

    2015-01-01

    Biological oil hydrocarbons degradation is a complicated process, influenced by hydrocarbons properties, microorganisms and environmental conditions. The aim of this work was to select microbial strain, capable of degrading heavy branched hydrocarbons for further application in environment remediation and bio-cracking. Also, it was necessary to select optimal conditions (temperature, pH, concentration and etc.) for selected microbial strain degrading heavy branched hydrocarbons. Since crude o...

  9. Chlorinated Withanolides from Withania somnifera

    OpenAIRE

    Tong, Xiaoqin; Zhang, Huaping; Timmermann, Barbara N.

    2011-01-01

    A chlorinated withanolide, 6α-chloro-5β,17α-dihydroxywithaferin A (1), and nine known withanolides, 6α-chloro-5β-hydroxywithaferin A (2), (22R)-5β-formyl-6β,27-dihydroxy-1-oxo-4-norwith-24-enolide, withaferin A, 2,3-dihydrowithaferin A, 3-methoxy-2,3-dihydrowithaferin A, 2,3-didehydrosomnifericin, withanone, withanoside IV and withanoside X, were isolated from Withania somnifera (Solanaceae). All structures were elucidated on the basis of spectroscopic methods (IR, HRESIMS, 1D/2D NMR). X-ray ...

  10. Chlorination of N-methylacetamide and amide-containing pharmaceuticals. Quantum-chemical study of the reaction mechanism.

    Science.gov (United States)

    Šakić, Davor; Šonjić, Pavica; Tandarić, Tana; Vrček, Valerije

    2014-03-27

    Chlorination of amides is of utmost importance in biochemistry and environmental chemistry. Despite the huge body of data, the mechanism of reaction between amides and hypochlorous acid in aqueous environment remains unclear. In this work, the three different reaction pathways for chlorination of N-methylacetamide by HOCl have been considered: the one-step N-chlorination of the amide, the chlorination via O-chlorinated intermediate, and the N-chlorination of the iminol intermediate. The high-level quantum chemical G3B3 composite procedure, double-hybrid B2-PLYPD, B2K-PLYP methods, and global hybrid M06-2X and BMK methods have been employed. The calculated energy barriers have been compared to the experimental value of ΔG(#)298 ≈ 87 kJ/mol, which corresponds to reaction rate constant k(r) ≈ 0.0036 M(-1) s(-1). Only the mechanism in which the iminol form of N-methylacetamide reacts with HOCl is consistent (ΔG(#)298 = 87.3 kJ/mol at G3B3 level) with experimental results. The analogous reaction mechanism has been calculated as the most favorable pathway in the chlorination of small-sized amides and amide-containing pharmaceuticals: carbamazepine, acetaminophen, and phenytoin. We conclude that the formation of the iminol intermediate followed by its reaction with HOCl is the general mechanism of N-chlorination for a vast array of amides.

  11. Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.

    Science.gov (United States)

    Korich, D G; Mead, J R; Madore, M S; Sinclair, N A; Sterling, C R

    1990-01-01

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water. PMID:2339894

  12. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  13. The Synthesis of Carbon Nanomaterials using Chlorinated ...

    African Journals Online (AJOL)

    The effect of chlorine on the morphology of carbon nanotubes (CNTs) prepared from a Fe-Co/CaCO3 catalyst was investigated using chlorobenzene (CB), dichlorobenzene (DCB), trichlorobenzene (TCB), dichloroethane (DCE), trichloroethane (TCE) and tetrachloroethane (TTCE) as chlorine sources using a catalytic ...

  14. Effectiveness of Chlorinated Water, Sodium Hypochlorite, Sodium ...

    African Journals Online (AJOL)

    This study evaluated the efficacy of chlorinated water, sodium hypochlorite solution, sodium chloride solution and sterile distilled water in eliminating pathogenic bacteria on the surfaces of raw vegetables. Lettuce vegetables were dipped in different concentrations of chlorinated water, sodium hypochlorite solution, sodium ...

  15. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  16. The origin of high hydrocarbon groundwater in shallow Triassic aquifer in Northwest Guizhou, China.

    Science.gov (United States)

    Liu, Shan; Qi, Shihua; Luo, Zhaohui; Liu, Fangzhi; Ding, Yang; Huang, Huanfang; Chen, Zhihua; Cheng, Shenggao

    2018-02-01

    Original high hydrocarbon groundwater represents a kind of groundwater in which hydrocarbon concentration exceeds 0.05 mg/L. The original high hydrocarbon will significantly reduce the environment capacity of hydrocarbon and lead environmental problems. For the past 5 years, we have carried out for a long-term monitoring of groundwater in shallow Triassic aquifer in Northwest Guizhou, China. We found the concentration of petroleum hydrocarbon was always above 0.05 mg/L. The low-level anthropogenic contamination cannot produce high hydrocarbon groundwater in the area. By using hydrocarbon potential, geochemistry and biomarker characteristic in rocks and shallow groundwater, we carried out a comprehensive study in Dalongjing (DLJ) groundwater system to determine the hydrocarbon source. We found a simplex hydrogeology setting, high-level water-rock-hydrocarbon interaction and obviously original hydrocarbon groundwater in DLJ system. The concentration of petroleum hydrocarbon in shallow aquifer was found to increase with the strong water-rock interaction. Higher hydrocarbon potential was found in the upper of Guanling formation (T 2 g 3 ) and upper of Yongningzhen formation (T 1 yn 4 ). Heavily saturated carbon was observed from shallow groundwater, which presented similar distribution to those from rocks, especially from the deeper groundwater. These results indicated that the high concentrations of original hydrocarbon in groundwater could be due to the hydrocarbon release from corrosion and extraction out of strata over time.

  17. Internal chlorination of Ni-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Berztiss, D.; Hennesen, K.; Grabke, H.J. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    1998-12-31

    In contrast to internal oxidation, sulfidation and carburization, very little information is available regarding internal chlorination, especially diffusion of chlorine in metallic alloys. This paper describes results of experiments on Ni-Cr alloys (<10 wt% Cr) exposed in an atmosphere containing radioactive HCl. The diffusion of chlorine in the alloy can be determined by measurement of residual {beta}-activity from the sample surface. Successively thin layers (0.5-10 {mu}m) of the alloy were removed by lapping and the surface activity was measured to obtain a depth profile. Both single and polycrystalline materials were tested. Through this work it should be determined if there is in fact solubility and diffusion of chlorine in Ni-based alloys as some authors have proposed or if the ingress of chlorine is mainly a grain boundary phenomenon. (orig.)

  18. Survival and oxygen consumption of Praunus flexuosus and Neomysis integer, and embryonic development of the latter species, in different temperature and chlorinity combinations

    Energy Technology Data Exchange (ETDEWEB)

    Vlasblom, A.G.; Elgershuizen, J.H.B.W.

    1977-01-01

    Communications of various authors have shown that in natural circumstances Neomysis integer lives in chlorinities ranging between almost 0 to 20% Cl and Praunus flexuosus in the range 2 to 23% Cl. In the Netherlands Neomysis is found in chlorinities of 0.1 to 16.5% Cl and Praunus in chlorinities of 6 to 19% Cl. It is possible that Neomysis inhabits environments of a lower chlorinity range than the related Praunus because of differences in tolerance to temperature and chlorinity. Therefore, experiments have been carried out in search of differences in the survival and oxygen consumption of the adults of both species in different temperature-chlorinity combinations. For Neomysis also the rate of development of the embryos and the numbers hatching were investigated under different conditions.

  19. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    Directory of Open Access Journals (Sweden)

    Angela eSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  20. Detection of sewage organic chlorination products that are resistant to dechlorination with sulfite

    Energy Technology Data Exchange (ETDEWEB)

    MacCrehan, W.A. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Analytical Chemistry Div.; Jensen, J.S.; Helz, G.R. [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry

    1998-11-15

    Most of the 36 billion gal of treated sewage wastewater discharged daily into the environment in the United States is disinfected via chlorination. To minimize toxicity. dechlorination with sulfite or sulfur dioxide is often performed. Although dechlorination is considered instantaneous and complete, several studies have found residual toxicity of chlorinated/dechlorinated effluent to aquatic life. The authors investigated chlorination/dechlorination of the organic nitrogen components of sewage wastewater using both iodometric titration and a novel LC method. For LC, a postcolumn reaction with iodide rendered submicromolar chloramine concentrations detectable with amperometry. Using a gradient-elution LC separation, the retention and dechlorination behavior of a suite of model amines was determined, representing primary and secondary aliphatic, peptide, and protein-N. Chlorination/dechlorination experiments on freshly collected, tertiary-treated wastewater showed a fraction of the organic N-chloramines are dechlorinated slowly by sulfite with half-lives of >20 min. Chromatographic retention and kinetic behavior of the sewage N-chloramines was consistent with the behavior of the model peptides and proteins. Proteolytic hydrolysis markedly increased the peptide fraction observed upon chlorination of the wastewater. These results suggest that peptides and proteins contribute to slow dechlorination of sewage and may be a factor in the toxicity noted for chlorine-disinfected wastewater.

  1. Decontamination of a hospital room using gaseous chlorine dioxide: Bacillus anthracis, Francisella tularensis, and Yersinia pestis.

    Science.gov (United States)

    Lowe, John J; Gibbs, Shawn G; Iwen, Peter C; Smith, Philip W; Hewlett, Angela L

    2013-01-01

    This study assessed the efficacy of gaseous chlorine dioxide for inactivation of Bacillus anthracis, Francisella tularensis, and Yersinia pestis in a hospital patient care suite. Spore and vegetative cells of Bacillus anthracis Sterne 34F2, spores of Bacillus atrophaeus ATCC 9372 and vegetative cells of both Francisella tularensis ATCC 6223 and Yersinia pestis A1122 were exposed to gaseous chlorine dioxide in a patient care suite. Organism inactivation was then assessed by log reduction in viable organisms postexposure to chlorine dioxide gas compared to non-exposed control organism. Hospital room decontamination protocols utilizing chlorine dioxide gas concentrations of 377 to 385 ppm maintained to exposures of 767 ppm-hours with 65% relative humidity consistently achieved complete inactivation of B. anthracis and B. atrophaeus spores, as well as vegetative cells of B. anthracis, F. tularensis, and Y. pestis. Decrease in exposure (ppm-hours) and relative humidity (8 log reductions in organisms. Up to 10-log reductions were achieved in a hospital room with limited impact on adjacent areas, indicating chlorine dioxide concentrations needed for decontamination of highly concentrated (>6 logs) organisms can be achieved throughout a hospital room. This study translates laboratory chlorine dioxide fumigation studies applied in a complex clinical environment.

  2. Effects of Chlorine Stress on Pseudomonas aeruginosa Biofilm and Analysis of Related Gene Expressions.

    Science.gov (United States)

    Kekeç, Özge; Gökalsın, Barış; Karaltı, İskender; Kayhan, Figen Esin; Sesal, Nüzhet Cenk

    2016-08-01

    Chlorine is deployed worldwide to clean waters and prevent water-originated illnesses. However, chlorine has a limited disinfection capacity against biofilms. Microorganisms form biofilms to protect themselves from biological threats such as disinfectant chemicals. Pseudomonas aeruginosa is an opportunistic pathogen and its biofilm form attaches to surfaces, living buried into exopolysaccharides, can be present in all watery environments including tap water and drinking water. This research aimed to study the biofilm trigger mechanism of the opportunistic pathogen P. aeruginosa PAO1 strain, which is known to form biofilm in water supply systems and human body, under chlorine stress levels. In addition to biofilm staining, certain genes that are relevant to the stress condition were selected for gene expression analysis. The bacteria cultures were grown under chlorine stress with concentrations of 0.5, 0.7 and 1 mg/l. Six gene regions were determined related to biofilm and stress response: rpoS, bifA, migA, katB, soxR, and algC. Biofilm formation was analyzed by basic fuchsin staining, and gene expressions were quantified by quantitative real-time PCR. According to the results, highest biofilm production was observed in P. aeruginosa PAO1 wild strain under no stress conditions. Higher biofilm amounts were observed for bacteria under 0.5 and 0.7 mg/l chlorine stress compared to 1 mg/l chlorine stress.

  3. Industrial metabolism of chlorine: a case study of a chlor-alkali industrial chain.

    Science.gov (United States)

    Han, Feng; Li, Wenfeng; Yu, Fei; Cui, Zhaojie

    2014-05-01

    Substance flow analysis (SFA) is applied to a case study of chlorine metabolism in a chlor-alkali industrial chain. A chain-level SFA model is constructed, and eight indices are proposed to analyze and evaluate the metabolic status of elemental chlorine. The primary objectives of this study are to identify low-efficiency links in production processes and to find ways to improve the operational performance of the industrial chain. Five-year in-depth data collection and analysis revealed that system production efficiency and source efficiency continued increasing since 2008, i.e., when the chain was first formed, at average annual growth rates of 21.01 % and 1.01 %, respectively. In 2011, 64.15 % of the total chlorine input was transformed into final products. That is, as high as 98.50 % of the chlorine inputs were utilized when other by-products were counted. Chlorine loss occurred mostly in the form of chloride ions in wastewater, and the system loss rate was 0.54 %. The metabolic efficiency of chlorine in this case was high, and the chain system had minimal impact on the environment. However, from the perspectives of processing depth and economic output, the case study of a chlor-alkali industrial chain still requires expansion.

  4. Chlorination induced damage and recovery in marine diatoms: Assay by SYTOX® Green staining.

    Science.gov (United States)

    Venkatnarayanan, Srinivas; Sriyutha Murthy, P; Nancharaiah, Yarlagadda V; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

    2017-11-30

    Phytoplankton entrained into cooling water systems of coastal power stations are subjected to acute chemical stress due to biocides (chlorine) used for biofouling control. They are subsequently released into the environment, where they may survive/recover or succumb. Experiments were conducted to evaluate the susceptibility of a centric (Chaetoceros lorenzianus) and pennate (Navicula sp.) diatom to in-plant administered concentrations of chlorine (0.2-0.5mg/L, TRO). Viability of cells exposed to chlorine was assessed by SYTOX® Green fluorimetry and was compared with other conventional end points like total cell counts, chlorophyll a content and cellular autofluorescence. Results showed a concentration-dependant reduction in viability, chlorophyll a and autofluorescence. C. lorenzianus cells were more susceptible to chlorine compared to Navicula sp. SYTOX® Green staining appears to be a sensitive method to assess chlorine-induced damages. The data show that in-use levels of chlorination can potentially impact entrained organisms; however, they can recover when returned to coastal waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Chlorine signal attenuation in concrete.

    Science.gov (United States)

    Naqvi, A A; Maslehuddin, M; ur-Rehman, Khateeb; Al-Amoudi, O S B

    2015-11-01

    The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Emissions minimization of chlorinated micropollutants in coal solid waste co-combustion by primary measures

    Energy Technology Data Exchange (ETDEWEB)

    Pandelova, M.; Lenoir, D.; Schramm, K.W. [GSF-Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany)

    2005-07-01

    This study addresses co-combustion of coal-solid waste mixtures in pilot and laboratory-scale combustors, with emphasis on monitoring of toxic chlorinated hydrocarbon emissions like: polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB) and polychlorinated benzenes (PCBz). The objectives of the work are stress on the so-called primary measures technique which cause reduction of the toxic emission prior formation the chlorinated micropollutants. Thermally resistant inorganic compounds were added directly to the fuel. The fuel-types used in this study are lignite coal from Puertollano (CIEMAT, Spain), pre-treated municipal solid waste (Rethmann Plano GmbH) and PVC (waste from ground floor). Two low cost and non- toxic nitrogen- and sulfur-compounds were considered as the most effective inhibitors for PCDD/F formation. That makes them applicable for use in a full scale combustion unit. (orig.)

  7. Analysis of Chlorination & UV Effects on Microplastics Using Raman

    Science.gov (United States)

    Kelkar, Varun

    Microplastics are emerging to be major problem when it comes to water pollution and they pose a great threat to marine life. These materials have the potential to affect a wide range of human population since humans are the major consumers of marine organisms. Microplastics are less than 5 mm in diameter, and can escape from traditional wastewater treatment plant (WWTP) processes and end up in our water sources. Due to their small size, they have a large surface area and can react with chlorine, which it encounters in the final stages of WWTP. After the microplastics accumulate in various bodies of water, they are exposed to sunlight, which contains oxidative ultraviolet (UV) light. Since the microplastics are exposed to oxidants during and after the treatment, there is a strong chance that they will undergo chemical and/or physical changes. The WWTP conditions were replicated in the lab by varying the concentrations of chlorine from 70 to 100 mg/L in increments of 10 mg/L and incubating the samples in chlorine baths for 1-9 days. The chlorinated samples were tested for any structural changes using Raman spectroscopy. High density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP) were treated in chlorine baths and observed for Raman intensity variations, Raman peak shifts, and the formation of new peaks over different exposure times. HDPE responded with a lot of oxidation peaks and shifts of peaks after just one day. For the degradation of semi-crystalline polymers, there was a reduction in crystallinity, as verified by thermal analysis. There was a decrease in the enthalpy of melting as well as the melting temperature with an increase in the exposure time or chlorine concentration, which pointed at the degradation of plastics and bond cleavages. To test the plastic response to ii UV, the samples were exposed to sunlight for up to 210 days and analyzed under Raman spectroscopy. Overall the physical and chemical changes with the polymers are evident and

  8. Formation of chlorinated lipids post-chlorine gas exposure.

    Science.gov (United States)

    Ford, David A; Honavar, Jaideep; Albert, Carolyn J; Duerr, Mark A; Oh, Joo Yeun; Doran, Stephen; Matalon, Sadis; Patel, Rakesh P

    2016-08-01

    Exposure to chlorine (Cl2) gas can occur during accidents and intentional release scenarios. However, biomarkers that specifically indicate Cl2 exposure and Cl2-derived products that mediate postexposure toxicity remain unclear. We hypothesized that chlorinated lipids (Cl-lipids) formed by direct reactions between Cl2 gas and plasmalogens serve as both biomarkers and mediators of post-Cl2 gas exposure toxicities. The 2-chloropalmitaldehyde (2-Cl-Pald), 2-chlorostearaldehyde (2-Cl-Sald), and their oxidized products, free- and esterified 2-chloropalmitic acid (2-Cl-PA) and 2-chlorostearic acid were detected in the lungs and plasma of mouse and rat models of Cl2 gas exposure. Levels of Cl-lipids were highest immediately post-Cl2 gas exposure, and then declined over 72 h with levels remaining 20- to 30-fold higher at 24 h compared with baseline. Glutathione adducts of 2-Cl-Pald and 2-Cl-Sald also increased with levels peaking at 4 h in plasma. Notably, 3-chlorotyrosine also increased after Cl2 gas exposure, but returned to baseline within 24 h. Intranasal administration of 2-Cl-PA or 2-Cl-Pald at doses similar to those formed in the lung after Cl2 gas exposure led to increased distal lung permeability and inflammation and systemic endothelial dysfunction characterized by loss of eNOS-dependent vasodilation. These data suggest that Cl-lipids could serve as biomarkers and mediators for Cl2 gas exposure and toxicity. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  9. Derivation of validated methods of sampling and analysis for intermediate and final products of the anaerobic material utilization of volatile chlorinated hydrocarbons (LCFC) in groundwater in the context of analyses of contaminated soils; Ableitung validierter Probenahme- und Analysenmethoden fuer Zwischen- und Endprodukte der anaeroben Stoffverwertungsprozesse von Leichtfluechtigen Chlorierten Kohlenwasserstoffen (LCKW) im Grundwasser im Rahmen von Altlastenuntersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Dorgerloh, Ute; Becker, Roland; Win, Tin [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Theissen, Hubert [IMAGO GbR (Germany)

    2010-06-17

    The results of the project ''Methods of sampling and analysis of intermediate and final products of the anaerobic degradation of volatile halogenated hydrocarbons in groundwater in frame of analysis of contaminated sites'' of the German Federal States Program ''Water, Soil, Waste'' (Laenderfinanzierungsprogramm ''Wasser, Boden, Luft'') LFP B2.08 are presented in these report. Different methods of sampling and analysis for the determination of hydrogen, methane, ethene and vinyl chloride in groundwater are developed and validated: For the sampling are described and discussed: i. active sampling: purge and sample of water samples and purging of solvated gases in groundwater in gas sampling tubes ii. passive sampling: diffusion sampling in polyethylene diffusion bags (PDB) and plastic syringes as diffusion sampler for solvated gases The use of active (purge and sample, downhole sampler) and passive (diffusion sampling) sampling techniques for the quantification of VOC, ethene, and methane are evaluated from the viewpoint of public authorities and regarding the reproducibility of measurement results. Based on a groundwater contaminated with trichloroethene, 1,2-dichloroethene, and vinyl chloride it is shown that passive sampling is restricted by low groundwater flow and biological activity inside the well casing. Therefore, active sampling is to be preferred in case of unknown or insufficient flow conditions in the aquifer. The methods of chromatography for the determination of the compounds are validated and compared with other appropriate analytical methods: I. Headspace-GC-FID for the determination of methane, ethene and vinyl chloride in water of the purged sample (i) and the water of the PDB (ii) II. Direct injection - GC-PDD for the determination of hydrogen from the collected gas samples of the gas sampling tube (i) and the plastic syringes (ii) The gas chromatographic procedure for vinyl chloride using

  10. Influence of Chlorine Emissions on Ozone Levels in the Troposphere

    Science.gov (United States)

    Chlorine emissions from cooling towers are emitted mainly as hypochlous acid, not as molecular chlorine. Chlorine emissions from cooling towers in electric utilities in the U.S. are estimated to be 4,400 tons per year. Molecular chlorine increases more tropospheric ozone than hyp...

  11. δ³⁷Cl : the geochemistry of chlorine isotopes

    NARCIS (Netherlands)

    Eggenkamp, H.G.M.

    1994-01-01

    In this thesis the geochemistry of the stable isotopes of chlorine will be examined. Chlorine is one of the halogens, the seventh group in the periodic system of elements. This group consists of five elements, fluorine, chlorine, bromine, iodine, and astatine. This thesis presents the first chlorine

  12. Chlorination of Wastewater, Manual of Practice No. 4.

    Science.gov (United States)

    Water Pollution Control Federation, Washington, DC.

    This manual reviews chlorination practices in the treatment and disposal of wastes from the earliest known applications. The application of chlorination for various purposes is described but no attempt has been made to compare chlorination with other methods. Included are chapters on the development and practice of wastewater chlorination,…

  13. Chlorination. Training Module 2.300.2.77.

    Science.gov (United States)

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with chlorine, the reasons for chlorination and safe operation and maintenance of gas chlorine, dry calcium hypochlorite and liquid sodium hypochlorite chlorination systems for water supply and wastewater treatment facilities. Included are…

  14. Toxicity of chlorine to zebrafish embryos

    Science.gov (United States)

    Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

    2014-01-01

    Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

  15. A comparison of the virucidal properties of chlorine, chlorine dioxide, bromine chloride and iodine.

    OpenAIRE

    Taylor, G R; Butler, M.

    1982-01-01

    Chlorine dioxide, bromine chloride and iodine were compared with chlorine as virucidal agents. Under optimal conditions all disinfectants were effective at low concentrations, but each disinfectant responded differently to acidity and alkalinity. Disinfection by chlorine was impaired by the presence of ammonia, but the other disinfectants retained much of their potency. Disinfection of poliovirus by iodine resulted in structural changes in the virions as seen by electron micrroscopy, but the ...

  16. Modeling adsorption of brominated, chlorinated and mixed bromo/chloro-dibenzo-p-dioxins on C60 fullerene using Nano-QSPR

    Directory of Open Access Journals (Sweden)

    Piotr Urbaszek

    2017-03-01

    Full Text Available Many technological implementations in the field of nanotechnology have involved carbon nanomaterials, including fullerenes such as the buckminsterfullerene, C60. The unprecedented properties of such organic nanomaterials (in particular their large surface area gained extensive attention for their potential use as organic pollutant sorbents. Sorption interactions can be very hazardous and useful at the same time. This work investigates the influence of halogenation by bromine and/or chlorine in dibenzo-p-dioxins on their sorption ability on the C60 fullerene surface. Halogenated dibenzo-p-dioxins (PXDDs, where X = Br or Cl are ever-present in the environment and accidently produced in many technological processes in only approximately known quantities. If all combinatorial Br and/or Cl dioxin substitution possibilities are present in the environment, the experimental characterization and investigation of sorbent effectiveness is more than difficult. In this work, we have developed a quantitative structure–property relationship (QSPR model (R2 = 0.998, predicting the adsorption energy [kcal/mol] for 1,701 PXDDs adsorbed on C60 (PXDD@C60. Based on the QSPR model reported herein, we concluded that the lowest energy PXDD@C60 complexes are those that the World Health Organization (WHO considers to be less dangerous with respect to the aryl hydrocarbon receptor (AhR toxicity mechanism. Therefore, the effectiveness of fullerenes as sorbent agents may be underestimated as sorption could be less effective for toxic congeners than previously believed.

  17. Ozone depletion and chlorine loading potentials

    Science.gov (United States)

    Pyle, John A.; Wuebbles, Donald J.; Solomon, Susan; Zvenigorodsky, Sergei; Connell, Peter; Ko, Malcolm K. W.; Fisher, Donald A.; Stordal, Frode; Weisenstein, Debra

    1991-01-01

    The recognition of the roles of chlorine and bromine compounds in ozone depletion has led to the regulation or their source gases. Some source gases are expected to be more damaging to the ozone layer than others, so that scientific guidance regarding their relative impacts is needed for regulatory purposes. Parameters used for this purpose include the steady-state and time-dependent chlorine loading potential (CLP) and the ozone depletion potential (ODP). Chlorine loading potentials depend upon the estimated value and accuracy of atmospheric lifetimes and are subject to significant (approximately 20-50 percent) uncertainties for many gases. Ozone depletion potentials depend on the same factors, as well as the evaluation of the release of reactive chlorine and bromine from each source gas and corresponding ozone destruction within the stratosphere.

  18. Intoxication of 76 children by chlorine gas.

    Science.gov (United States)

    Fleta, J; Calvo, C; Zuñiga, J; Castellano, M; Bueno, M

    1986-03-01

    A collective intoxication with chlorine gas in 76 children (21 males, 55 females; the median age was 9.9 years) is reported. They were treated with a combination of oxygen gas (O2) and corticosteroids until the symptoms disappeared.

  19. Chlorinated drinking water for lightweight laying hens

    National Research Council Canada - National Science Library

    Schneider, A.F; Almeida, D.S; Moraes, A.N; Picinin, L.C.A; Oliveira, V; Gewehr, C.E

    2016-01-01

    ABSTRACT The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia...

  20. Behavior of chlorine during coal pyrolysis

    Science.gov (United States)

    Shao, D.; Hutchinson, E.J.; Cao, H.; Pan, W.-P.; Chou, C.-L.

    1994-01-01

    The behavior of chlorine in Illinois coals during pyrolysis was evaluated by combined thermo-gravimetry-Fourier transform infrared spectroscopy-ion chromatography (TG-FTIR-IC) techniques. It was found that more than 90% of chlorine in Illinois coals (IBC-103, 105, 106, and 109) was liberated as HCl gas during pyrolysis from 300 to 600??C, with the rate reaching a maximum at 440 ??C. Similarity of the HCl and NH3 release profiles during pyrolysis of IBC-109 supports the hypothesis that the chlorine in coal may be associated with nitrogen and the chlorine is probably bonded to the basic nitrogen sites on the inner walls of coal micropores. ?? 1994 American Chemical Society.

  1. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Science.gov (United States)

    2010-04-01

    ... percent in plastic articles prepared from polyvinyl chloride and/or from vinyl chloride copolymers... Chlorine in Vinyl Chloride Polymers and Copolymers,” which is incorporated by reference (Copies may be...

  2. HYDROCARBON PROSPECTING OVE DROCARBON ...

    African Journals Online (AJOL)

    eobe

    e trapping configurations of the faults mbedding shale were presumed to be the creation of multiple reservoir of hydrocarbon bearing formations one horizon to the other and. (Figure 2). The vertical f the major and subsidiary growth t the amount of throw of both major s are small and varied from line to line survey but ...

  3. Kinetics of hematite chlorination with Cl2 and Cl2 + O2: Part I. Chlorination with Cl2

    OpenAIRE

    KANARI, Ndue; Mishra, Devabrata; Filippov, Lev; Diot, Frédéric; Mochón, Javier; Allain, Eric

    2010-01-01

    International audience; Preliminary tests of the chlorination of two iron oxides (wüstite and hematite) in various chlorinating gas mixtures were performed by thermogravimetric analysis (TGA) under non-isothermal conditions. Wüstite started to react with chlorine from about 200 °C generating ferric chloride and hematite as the final reaction products. The presence of a reducing and oxidizing agent in the chlorinating gas mixtures influenced the chlorination reactions of both iron oxides, duri...

  4. Surrogate measurement of chlorine concentration on steel surfaces by alkali element detection via laser-induced breakdown spectroscopy

    Science.gov (United States)

    Xiao, X.; Le Berre, S.; Hartig, K. C.; Motta, A. T.; Jovanovic, I.

    2017-04-01

    Chlorine can play an important role in the process of stress corrosion cracking of dry cask storage canisters for used nuclear fuel, which are frequently located in marine environments. It is of significant interest to determine the surface concentration of chlorine on the stainless steel canister surface, but measurements are often limited by difficult access and challenging conditions, such as high temperature and high radiation fields. Laser-induced breakdown spectroscopy (LIBS) could enable chlorine concentration measurements while meeting the other constraints of this application, but suffers from high excitation energy of chlorine and the interference of the atomic emission lines of iron, thus limiting the sensitivity of detection, especially when LIBS has to be delivered over an optical fiber. We demonstrate that chlorine surface concentrations in the range of 0.5-100 mg/m2 can be inferred by the detection and quantification of sodium contained in chlorine salts if the speciation and neutralization of salts are not of major concern, whereas minor components of sea salt such as magnesium and potassium are less attractive as surrogates for chlorine due to the lower sensitivity of LIBS for their detection and quantification. The limit of detection, measurement accuracy, and other features and limitations of this surrogate measurement approach are discussed.

  5. Uptake, turnover and distribution of chlorinated fatty acids in aquatic biota

    Energy Technology Data Exchange (ETDEWEB)

    Bjoern, Helena

    1999-09-01

    Chlorinated fatty acids (CIFAs) are the major contributors of extractable, organically bound chlorine in fish lipids. A known anthropogenic source of CIFAs is chlorine bleached pulp production. Additional anthropogenic sources may exist, e.g., chlorine-containing discharge from industrial and household waste and they may also occur naturally. CIFAs have a wide geographic distribution. They have, for instance, been identified in fish both from Alaskan and Scandinavian waters. In toxicological studies of CIFAs, the most pronounced effects have been found in reproductive related processes. CIFAs have also been shown to disrupt cell membrane functions. The present study was carried out to further characterise the ecotoxicological properties of CIFAs and their presence in biota. To investigate the biological stability of CIFAs, two experiments were carried out using radiolabelled chlorinated and non-chlorinated fatty acids. In both experiments, CIFAs were taken up from food by fish and assimilated to lipids. From the first experiment it was concluded that the chlorinated fatty acid investigated was turned over in the fish to a lower degree than the non-chlorinated analogue. In the second experiment, the transfer of a chlorinated fatty acid was followed over several trophic levels and the chlorinated fatty acid was transferred to the highest trophic level. In samples with differing loads of persistent organic pollutants (POPs) from both fish and marine mammals, high concentrations and diversity of CIFAs were detected. This was also observed in samples with low POP concentration. Chlorohydroxy fatty acids made up a considerable portion of the CIFAs in certain samples, both from limnic fish and marine mammals. CIFAs in fish were found to be bound in complex lipids such as triacylglycerols (storage lipids) and phospholipids, as well as in acyl sterols (membrane lipids). In the marine mammals investigated, high concentrations of CIFAs were mainly bound in phospholipids. If

  6. Reaction mechanism for chlorination of urea.

    Science.gov (United States)

    Blatchley, Ernest R; Cheng, Mingming

    2010-11-15

    Experiments were conducted to elucidate the mechanism of the reaction between free chlorine and urea. In combination with findings of previous investigations, the results of these experiments indicate a process by which urea undergoes multiple N-chlorination steps. The first of these steps results in the formation of N-chlorourea; this step appears to require Cl₂ to proceed and is the overall rate-limiting step in the reaction for conditions that correspond to most swimming pools. N-Chlorourea then appears to undergo further chlorine substitution; the fully N-chlorinated urea molecule is hypothesized to undergo hydrolysis and additional chlorination to yield NCl₃ as an intermediate. NCl₃ is hydrolyzed to yield NH₂Cl and NHCl₂, with subsequent decay to stable end products, including N₂ and NO₃⁻. Conversion of urea-N to nitrate is pH-dependent. The pattern of nitrate yield is believed to be attributable to the fact that when urea serves as the source of reduced-N, entry into the reactions that describe chlorination of ammoniacal nitrogen is through NCl₃, whereas when NH₃ is the source of reduced-N, entry to these reactions is through NH₂Cl.

  7. Chlorinated drinking water for lightweight laying hens

    Directory of Open Access Journals (Sweden)

    A.F. Schneider

    Full Text Available ABSTRACT The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control, 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation. The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.

  8. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria Reactivityfactor 21 280-290 Aromatic...

  9. New model of chlorine-wall reaction for simulating chlorine concentration in drinking water distribution systems.

    Science.gov (United States)

    Fisher, Ian; Kastl, George; Sathasivan, Arumugam

    2017-11-15

    Accurate modelling of chlorine concentrations throughout a drinking water system needs sound mathematical descriptions of decay mechanisms in bulk water and at pipe walls. Wall-reaction rates along pipelines in three different systems were calculated from differences between field chlorine profiles and accurately modelled bulk decay. Lined pipes with sufficiently large diameters (>500 mm) and higher chlorine concentrations (>0.5 mg/L) had negligible wall-decay rates, compared with bulk-decay rates. Further downstream, wall-reaction rate consistently increased (peaking around 0.15 mg/dm 2 /h) as chlorine concentration decreased, until mass-transport to the wall was controlling wall reaction. These results contradict wall-reaction models, including those incorporated in the EPANET software, which assume wall decay is of either zero-order (constant decay rate) or first-order (wall-decay rate reduces with chlorine concentration). Instead, results are consistent with facilitation of the wall reaction by biofilm activity, rather than surficial chemical reactions. A new model of wall reaction combines the effect of biofilm activity moderated by chlorine concentration and mass-transport limitation. This wall reaction model, with an accurate bulk chlorine decay model, is essential for sufficiently accurate prediction of chlorine residuals towards the end of distribution systems and therefore control of microbial contamination. Implementing this model in EPANET-MSX (or similar) software enables the accurate chlorine modelling required for improving disinfection strategies in drinking water networks. New insight into the effect of chlorine on biofilm can also assist in controlling biofilm to maintain chlorine residuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Aqueous chlorination of fenamic acids: Kinetic study, transformation products identification and toxicity prediction.

    Science.gov (United States)

    Ma, Liyun; Li, Jian; Xu, Li

    2017-05-01

    Fenamic acids, one important type of non-steroidal anti-inflammatory drugs, are ubiquitous in environmental matrices. Thus it is of high significance to know the fate of them during chlorination disinfection considering their potential toxicity to the environment and humans. In the present study, the chlorination kinetics of three fenamic acids, i.e. mefenamic acid (MEF), tolfenamic acid (TOL) and clofenamic acid (CLO), were examined at different pHs, which followed second-order reaction under studied conditions. The studied fenamic acids degraded fast, with the largest apparent second-order rate coefficient (kapp) values of 446.7 M-1 s-1 (pH 7), 393.3 M-1 s-1 (pH 8) and 360.0 M-1 s-1 (pH 6) for MEF, TOL and CLO, respectively. The transformation products (TPs) were identified by solid-phase extraction-liquid chromatography-mass spectrometer and ion-pair liquid-liquid extraction and injection port derivatization-gas chromatography-mass spectrometer. Despite different numbers of TPs were detected for each studied fenamic acid through these two analytical methods, the types of TPs were almost the same; chlorine substitution, oxidation and the joint oxidation with chlorine substitution are transformation reactions involved in chlorination. Moreover, the total toxicity of the TPs was assayed based on luminescent bacteria. Under different pHs, the different types of TPs might form, resulting in the varied total toxicity. The toxicity of all three fenamic acids chlorinated at pH of 8 was greater than those at pHs of 6 and 7. This study provided the information about the kinetics, transformation and toxicity of three fenamic acids during water chlorination, which is important to the drinking water safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Nuclear microprobe analysis of chlorine distribution in the blue-light-exposed rat retina

    Science.gov (United States)

    Chen, Enping; Pallon, Jan; Forslind, Bo

    1995-09-01

    Blue-light exposure is a possible environment factor which causes senile macular degeneration, a prominent cause of visual impairment in elderly. Blue-light exposure causes inner segment edema and photoreceptor degeneration, probably by inhibiting the sodium-potassium pump on the inner segment membrane. Disturbance of the pump function may cause chlorine and sodium redistribution in the inner and outer segments, and edema in the inner segment. In the present study, 11 eyes from 11 Sprague-Dawley rats were used. Six rats were exposed to blue light (404 nm) at a retinal dose of 380 kJ/m 2, five were control. Chlorine and sulphur distribution were measured with the Lund Nuclear Microprobe (beam size: 12 × 12 μm, proton energy: 2.55 MeV, beam density at the target: 10-20 pA/μm 2). The chlorine concentration was calculated using sulphur as reference. The secondary characteristic X-rays were measured with a Kevex Si(Li) detector. The mean chlorine concentration was 0.82 mg/mg sulphur in the control inner segment layer. It was 1.83 and 2.00 mg/mg sulphur, 1 and 12 h after exposure, respectively. The mean chlorine concentration was 2.55 mg/mg sulphur in the control outer segment layer. It was 1.17 and 1.21 mg/mg sulphur, 1 and 12 h after exposure, respectively. The sodium signal is severely attenuated by the detector window, and the sodium distribution is assumed to be indicated by the chlorine distribution since these two elements follow each other closely in the cellular edema caused by metabolic inhibition. An accumulation of chlorine and sodium could be one of the reasons of the inner segment edema after blue-light exposure.

  12. Effect of evaporative weathering and oil-sediment interaction on the fate and behavior of diluted bitumen in marine environments. Part 2. The water accommodated and particle-laden hydrocarbon species and toxicity of the aqueous phase.

    Science.gov (United States)

    Yang, Zeyu; Hua, Yujuan; Mirnaghi, Fatemeh; Hollebone, Bruce P; Jackman, Paula; Brown, Carl E; Yang, Chun; Shah, Keval; Landriault, Mike; Chan, Brian

    2018-01-01

    In this study, the water accommodated and particle-laden hydrocarbon species, and the toxicity of the aqueous phase after oil-sediment interactions by varying the weathering states of diluted bitumen (Cold Lake blend (CLB)), oil type from light to heavy, and sediment type. Compared to the original oils, the sediment-laden total petroleum hydrocarbons (TPH) contained fewer hydrocarbons in the carbon range C34 range. Sediment-laden oil amounts generally decreased with an increased viscosity and asphaltene content of the test oils, as well as with increased sediment particle size. The presence of sediments significantly decreased the oil accommodated in water due to the formation of oil particulate aggregates (OPA) after mixing and settling. Less water accommodated TPH and polycyclic aromatic hydrocarbons (PAHs) were observed for weathered CLB products. However, oil and sediment types did not clearly affect the water accommodated TPH and PAHs. Light molecular PAHs and their alkylated congeners accounted for most of the water accommodated PAH congeners. A microtoxicity test demonstrated that with or without sediment, and regardless of sediment type, the toxicity of the water phase did not change significantly. Light oil of Alberta sweet mixed blend (ASMB) had the highest toxicity, followed by fresh CLB, and then all other oils, suggesting that ASMB and fresh CLB had relatively higher levels of light toxic components dissolved in the water phase compared with the other tested oils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Microbial Hydrocarbon and ToxicPollutant Degradation Method

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Dietrich [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Janabi, Mustafa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); O' Neil, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Budinger, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-08-16

    The goal of this project is to determine optimum conditions for bacterial oxidation of hydrocarbons and long-chain alkanes that are representative of petroleum contamination of the environment. Polycyclic Aromatic Hydrocarbons (PAHs) are of concern because of their toxicity, low volatility, and resistance to microbial degradation, especially under anaerobic conditions. The uniqueness of our approach is to use carbon-11 in lieu of the traditional use of carbon-14.

  14. Effects of chlorine and chlorine dioxide on human rotavirus infectivity and genome stability.

    Science.gov (United States)

    Xue, Bin; Jin, Min; Yang, Dong; Guo, Xuan; Chen, Zhaoli; Shen, Zhiqiang; Wang, Xinwei; Qiu, Zhigang; Wang, Jingfeng; Zhang, Bin; Li, Junwen

    2013-06-15

    Despite the health risks posed by waterborne human rotavirus (HRV), little information is available concerning the effectiveness of chlorine or chlorine dioxide (ClO2), two common disinfectants of public water sources, against HRV and their effects on its genome remain poorly understood. This study investigated the effects of chlorine and ClO2 on purified HRV by using cell culture and RT-PCR to assess virus infectivity and genetic integrity, respectively. The disinfection efficacy of ClO2 was found to be higher than that of chlorine. According to the efficiency factor Hom model, Ct value (mg/L min) ranges required for a 4-log reduction of HRV at 20 °C by chlorine and ClO2 were 5.55-5.59 and 1.21-2.47 mg/L min, respectively. Detection of the 11 HRV genome segments revealed that damage to the 1227-2354 bp of the VP4 gene was associated with the disappearance of viral infectivity by chlorine. However, no complete accordance between culturing and RT-PCR assays was observed after treatment of HRV with ClO2. These results collectively indicate that the current practice of chlorine disinfection may be inadequate to manage the risk of waterborne HRV infection, and offer the potential to monitor the infectivity of HRV adapting PCR-based protocols in chlorine disinfection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Effect of UV irradiation on the proportion of organic chloramines in total chlorine in subsequent chlorination.

    Science.gov (United States)

    Zhang, Tian-Yang; Lin, Yi-Li; Xu, Bin; Xia, Sheng-Ji; Tian, Fu-Xiang; Gao, Nai-Yun

    2016-02-01

    This study investigated the changes of chlorine species and proportion of organic chloramines during the chlorination process after UV irradiation pretreatment in drinking water. It was found that the UV pretreatment could enhance the percentage of organic chloramines by increasing free chlorine consumption in the chlorination of raw waters. The percentage of organic chloramines in total chlorine increased with UV intensity and irradiation time in raw waters. However, for the humic acid synthesized water, the percentage of organic chloramines increased first and then decreased with the increase of UV irradiation time. The value of SUVA declined in both raw and humic acid synthesized waters over the UV irradiation time, which indicated that the decomposition of aromatic organic matter by UV could be a contributor to the increase of free chlorine consumption and organic chloramine proportion. The percentage of organic chloramines during chlorination of raw waters after 30-min UV irradiation pretreatment varied from 20.2% to 41.8%. Total chlorine decreased obviously with the increase of nitrate concentration, but the percentage of organic chloramines increased and was linearly correlated to nitrate concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Organochlorine Turnover in Forest Ecosystems: The Missing Link in the Terrestrial Chlorine Cycle

    Energy Technology Data Exchange (ETDEWEB)

    A Leri; S Myneni

    2011-12-31

    Research in the last 20 years has shown that chlorine undergoes transformations between inorganic and organic forms as part of a complex biogeochemical cycle in terrestrial systems. Natural organochlorine production appears to be associated with the decomposition of plant material on the soil surface, though the chlorine cycle budget implies that a proportion of natural organochlorine enters soil through plant litter and atmospheric deposition as well. Organochlorine compounds may form through biotic and abiotic pathways, but the rates and magnitude of production in the field remain undefined. We have performed a time-dependent trace of chlorine concentration through forest ecosystems, revealing distinct fractions of naturally produced organochlorine in plant biomass. Aliphatic organochlorine constitutes an intrinsic component of healthy leaves that persists through senescence and humification of the plant material, making a substantial contribution to the pool of soil organochlorine. Plant leaves also contain soluble aromatic organochlorine compounds that leach from leaf litter during early decay stages. As decay progresses, high concentrations of insoluble aromatic organochlorine accrue in the humus, through de novo production as well as adsorption. The rates of aromatic organochlorine production and degradation vary seasonally and conversely. This study presents the first unambiguous evidence that there exist multiple pools of chlorinated organic matter in the soil environment and that leaf litter deposition makes a significant and refractory contribution to the soil organochlorine pool, providing key insights into the biogeochemical chlorine cycle.

  17. Cross-Resistance of UV- or Chlorine Dioxide-Resistant Echovirus 11 to Other Disinfectants

    Directory of Open Access Journals (Sweden)

    Qingxia Zhong

    2017-10-01

    Full Text Available The emergence of waterborne viruses with resistance to disinfection has been demonstrated in the laboratory and in the environment. Yet, the implications of such resistance for virus control remain obscure. In this study we investigate if viruses with resistance to a given disinfection method exhibit cross-resistance to other disinfectants. Chlorine dioxide (ClO2- or UV-resistant populations of echovirus 11 were exposed to five inactivating treatments (free chlorine, ClO2, UV radiation, sunlight, and heat, and the extent of cross-resistance was determined. The ClO2-resistant population exhibited cross-resistance to free chlorine, but to none of the other inactivating treatments tested. We furthermore demonstrated that ClO2 and free chlorine act by a similar mechanism, in that they mainly inhibit the binding of echovirus 11 to its host cell. As such, viruses with host binding mechanisms that can withstand ClO2 treatment were also better able to withstand oxidation by free chlorine. Conversely, the UV-resistant population was not significantly cross-resistant to any other disinfection treatment. Overall, our results indicate that viruses with resistance to multiple disinfectants exist, but that they can be controlled by inactivating methods that operate by a distinctly different mechanism. We therefore suggest to utilize two disinfection barriers that act by different mechanisms in order to control disinfection-resistant viruses.

  18. Cross-Resistance of UV- or Chlorine Dioxide-Resistant Echovirus 11 to Other Disinfectants.

    Science.gov (United States)

    Zhong, Qingxia; Carratalà, Anna; Ossola, Rachele; Bachmann, Virginie; Kohn, Tamar

    2017-01-01

    The emergence of waterborne viruses with resistance to disinfection has been demonstrated in the laboratory and in the environment. Yet, the implications of such resistance for virus control remain obscure. In this study we investigate if viruses with resistance to a given disinfection method exhibit cross-resistance to other disinfectants. Chlorine dioxide (ClO2)- or UV-resistant populations of echovirus 11 were exposed to five inactivating treatments (free chlorine, ClO2, UV radiation, sunlight, and heat), and the extent of cross-resistance was determined. The ClO2-resistant population exhibited cross-resistance to free chlorine, but to none of the other inactivating treatments tested. We furthermore demonstrated that ClO2 and free chlorine act by a similar mechanism, in that they mainly inhibit the binding of echovirus 11 to its host cell. As such, viruses with host binding mechanisms that can withstand ClO2 treatment were also better able to withstand oxidation by free chlorine. Conversely, the UV-resistant population was not significantly cross-resistant to any other disinfection treatment. Overall, our results indicate that viruses with resistance to multiple disinfectants exist, but that they can be controlled by inactivating methods that operate by a distinctly different mechanism. We therefore suggest to utilize two disinfection barriers that act by different mechanisms in order to control disinfection-resistant viruses.

  19. Survival and virulence of copper- and chlorine-stressed Yersinia enterocolitica in Experimentally infected mice

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; McFeters, G.A.

    1987-08-01

    The effect of gastric pH on the viability and virulence of Yersinia enterocolitica 0:8 after exposure to sublethal concentrations of copper and chlorine was determined in mice. Viability and injury were assessed with a nonselective TLY agar and two selective media, TLYD agar and CIN agar. Both copper and chlorine caused injury which was manifested by the inability of the cells to grow on selective media. CIN agar was more restrictive to the growth of injured cells than TLYD agar. Injury of the exposed cells was further enhanced in the gastric environment of mice. Besides injury, the low gastric pH caused extensive loss of viability in copper-exposed cells. Lethality in the chlorine-exposed cells was less extensive, and a portion of the inoculum reached the small intestine 5 min postinoculation. No adverse effect on the injured cells was apparent in the small intestine, and a substantial revival of the injury occurred in 3 to 4 h after intraluminal inoculation. The virulence of chlorine-stressed Y. enterocolitica in orally inoculated mice was similar to that of the control culture, but copper-stressed cells showed reduced virulence. Virulence was partly restored by oral administration of sodium bicarbonate before the inoculation of copper-exposed cells. Neutralization of gastric acidity had no effect on the virulence of the control of chlorine-stressed cells.

  20. Aqueous chlorination of mefenamic acid: kinetics, transformation by-products and ecotoxicity assessment.

    Science.gov (United States)

    Adira Wan Khalit, Wan Nor; Tay, Kheng Soo

    2016-05-18

    Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and free available chlorine (FAC) was determined at 25 ± 0.1 °C. The result indicated that the degradation of Mfe by FAC is highly pH-dependent. When the pH was increased from 6 to 8, it was found that the kapp for the reaction between Mfe and FAC was decreased from 16.44 to 4.4 M(-1) s(-1). Characterization of the transformation by-products formed during the chlorination of Mfe was carried out using liquid chromatography-quadrupole time-of-flight accurate mass spectrometry. Four major transformation by-products were identified. These transformation by-products were mainly formed through hydroxylation, chlorination and oxidation reactions. Ecotoxicity assessment revealed that transformation by-products, particularly monohydroxylated Mfe which is more toxic than Mfe, can be formed during aqueous chlorination.

  1. Chlorine decay and trihalomethane formation following ferrate(VI) preoxidation and chlorination of drinking water.

    Science.gov (United States)

    Li, Cong; Luo, Feng; Dong, Feilong; Zhao, Jingguo; Zhang, Tuqiao; He, Guilin; Cizmas, Leslie; Sharma, Virender K

    2017-11-01

    This paper presents the effect of preoxidation with ferrate(VI) (FeVIO42-, Fe(VI)) prior to chlorination on chlorine decay and formation of disinfection by-products in filtered raw water from a full-scale drinking water treatment plant. The rate of chlorine decay became significantly faster as the concentration of ferrate(VI) increased. Chlorine degradation followed two first-order decay reactions with rate constants k1 and k2 for fast and slow decay, respectively. Kinetic modeling established the relationships between k1 and k2 and varying dosages of chlorine and ferrate(VI). When ferrate(VI) was used as a pre-oxidant, the levels of trihalomethanes (trichloromethane (TCM), dichlorobromomethane (DCBM), dibromochloromethane (DBCM), and tribromomethane (TBM)) in water samples decreased as the ferrate(VI) concentration increased. The concentrations of these trihalomethanes followed the order TCM > DCBM ≈ DBCM > TBM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  3. Hydrocarbon Degradation Potentials of Bacteria Isolated from Spent ...

    African Journals Online (AJOL)

    ADOWIE PERE

    environment (Okerentugba and Ezeronye, 2003). Lack of essential nutrients such as nitrogen and phosphorus is one of the major factors affecting biodegradation of hydrocarbon by microorganisms in soil and water environment. In this study, we attempt to identify bacteria which can utilize spent lubricating oil as carbon and ...

  4. The dioxines in environment and health; Les dioxines dans l'environnement et la sante

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-15

    Dioxines and furans are chlorinated polycyclic aromatic hydrocarbons. Their half life in environment are 10 years. their half life in human organism is 7 years. The techniques to measure and identify these components are complex. Dioxines emissions come from incomplete combustion. 60% of dioxines emissions come from domestic wastes incineration. Soils contamination is made by atmospheric particulates deposit. Dioxines are low soluble in water. The principal mode of exposure for man is the food chain (90 to 95% of global exposure). The effects of dioxines are cancer appearance, increase of congenital malformations, decrease of sex ratio at birth (excess of girls ), decrease of fertility, decrease of birth weight, late on sexual maturity and neurological development. Among other toxic effects are an increase of cardio vascular diseases and increase of lipid rate in blood. (N.C.)

  5. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    Energy Technology Data Exchange (ETDEWEB)

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  6. Isomers of nitric acid and chlorine nitrate

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, M.P.; Francl, M.M.; Rowland, F.S.; Hehre, W.J.

    1988-09-22

    Ab initio molecular orbital calculations at the HF/6-31G* and MP2/6-31G* levels have been performed on nitric acid and chlorine nitrate. Equilibrium geometries and electric dipole moments obtained from the MP2/6-31G* calculations are in good agreement with the respective experimental values, normal-mode (harmonic) vibrational frequencies and frequency shifts due to isotopic substitution calculated at this level support the most recent gas-phase infrared assignments for chlorine nitrate but suggest a reversal in the assignment of v/sub 5/ and v/sub 6/ for nitric acid. Calculations at the same levels of theory were also performed on peroxynitrous acid (HOONO) and chlorine peroxynitrite (ClOONO). The former is found to be 35 kcal/mol less stable than nitric acid at the MP2/6-31G* level; chlorine peroxynitrite is 30 kcal/mol higher in energy than chlorine nitrate. The possible role of these high-energy isomers in atmospheric processes is discussed.

  7. Chlorine monoxide (Cl(2)O) and molecular chlorine (Cl(2)) as active chlorinating agents in reaction of dimethenamid with aqueous free chlorine.

    Science.gov (United States)

    Sivey, John D; McCullough, Corey E; Roberts, A Lynn

    2010-05-01

    HOCl is often assumed to represent the active oxidant in solutions of free available chlorine (FAC). We present evidence that Cl(2)O and Cl(2) can play a greater role than HOCl during chlorination of the herbicide dimethenamid. Reaction orders in [FAC] were determined at various solution conditions and ranged from 1.10 +/- 0.13 to 1.78 +/- 0.22, consistent with the concurrent existence of reactions that appear first-order and second-order in [FAC]. Solution pH, [Cl(-)], [FAC], and temperature were systematically varied so that the reactivity and activation parameters of each FAC species could be delineated. Modeling of kinetic data afforded calculation of second-order rate constants (units: M(-1) s(-1)) at 25 degrees C: k(Cl2O) = (1.37 +/- 0.17) x 10(6), k(Cl2) = (1.21 +/- 0.06) x 10(6), and k(HOCl) = 0.18 +/- 0.10. Under conditions typical of drinking water chlorination, Cl(2)O is the predominant chlorinating agent of dimethenamid. To the extent that Cl(2)O represents the active species in reactions with other disinfection byproduct (DBP) precursors, the influence of [FAC] and pH on DBP precursor reaction rates is different than if HOCl were the principal oxidant. Moreover, these findings call into question the validity of apparent rate constants (k(app)) commonly reported in the chlorination literature.

  8. Chlorination of organophosphorus pesticides in natural waters.

    Science.gov (United States)

    Acero, Juan L; Benítez, F Javier; Real, Francisco J; González, Manuel

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 degrees C and pH 7 were determined to be 110.9, 0.004 and 191.6 M(-1) s(-1) for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L(-1) was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.

  9. Chlorination of organophosphorus pesticides in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: jlacero@unex.es; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 {sup o}C and pH 7 were determined to be 110.9, 0.004 and 191.6 M{sup -1} s{sup -1} for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L{sup -1} was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.

  10. Phosphate valorization by dry chlorination route

    Directory of Open Access Journals (Sweden)

    Kanari N.

    2016-01-01

    Full Text Available This work deals with the extraction of phosphorus chlorinated compounds from phosphate materials using chlorination with gaseous chlorine. An industrial sample of dicalcium phosphate dihydrate, after transformation into calcium pyrophosphate (Ca2P2O7, is subjected to reactions with Cl2+CO+N2 and Cl2+C+N2 at temperatures ranging from 625 to 950°C using boat experiments. Gathering results of the thermodynamic predictions and TG/DT analysis with those of SEM and XRD examinations of the chlorinated residues allowed the interpretation of phenomena and reactions mechanism occurring during the calcium pyrophosphate carbochlorination. Reaction rate of Ca2P2O7 by Cl2+CO+N2 at 950°C is slowed down due to the formation of a CaCl2 liquid layer acting as a barrier for the diffusion of the reactive gases and further reaction progress. While, the carbochlorination with Cl2+C+N2 led to almost full chlorination of Ca2P2O7 at 750°C and the process proceeds with an apparent activation energy of about 104 kJ/mol between 625 and 750°C. Carbochlorination technique can be considered as an alternative and selective route for the valorization of low grade phosphates and for the phosphorus extraction from its bearing materials.

  11. The origin of aliphatic hydrocarbons in olive oil.

    Science.gov (United States)

    Pineda, Manuel; Rojas, María; Gálvez-Valdivieso, Gregorio; Aguilar, Miguel

    2017-11-01

    There are many substances that can interfere with olive oil quality. Some of them are well characterized, but many others have an unknown origin. Saturated hydrocarbons make an extraordinary complex family of numerous molecules, some of them present naturally in vegetable oils. When major natural saturated hydrocarbons are analyzed by standard chromatographic methods, this complex mixture of saturated hydrocarbons appears as a hump in the chromatogram and is commonly named as unresolved complex mixture (UCM), whose origin remains unknown. In this work we studied the occurrence and the origin of aliphatic saturated hydrocarbons in olive oil. Hydrocarbons were analyzed in olive oil and along the industrial process of oil extraction. We also analyzed n-alkanes and the UCM fraction of hydrocarbons in leaf, fruit and oil from different varieties and different locations, and we also analyzed the soils at these locations. We conclude that the hydrocarbons present in olive oil do not necessarily have their origin in a contamination during olive oil elaboration; they seem to have a natural origin, as a result of olive tree metabolism and/or as the result of an intake and accumulation by the olive tree directly from the environment during its entire life cycle. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Les hydrocarbures aromatiques polycycliques dans l'environnement : la réhabilitation des anciens sites industriels The Polycyclic Aromatic Hydrocarbons in the Environment : the Former Industrial Sites Remediation

    Directory of Open Access Journals (Sweden)

    Costes J. M.

    2006-12-01

    Full Text Available Les hydrocarbures aromatiques polycycliques ou HAP peuvent être d'origine naturelle mais ils proviennent principalement des processus de pyrolyse. On peut les retrouver dans les sols de certains anciens sites industriels. Cela peut être le cas des sites d'anciennes usines à gaz. Même si aucune conséquence sur la santé humaine n'a été signalée et même si les risques paraissent virtuels, le principe de précaution rend nécessaire de s'occuper des risques liés à ces anciens sites industriels. Gaz de France, propriétaire de 467 sites d'anciennes usines à gaz assume l'héritage industriel dans le cadre d'un protocole signé avec le ministère de l'Environnement. Après une étude des sols, une évaluation des risques est réalisée. En fonction des résultats de cette évaluation des risques et de l'usage du site (actuel et prévu, des solutions de traitement peuvent être mises en Suvre. Parmi les techniques applicables aux sols pollués par des HAP, un intérêt particulier s'est porté sur les traitements biologiques, en pleine évolution, qui offrent une solution économique bien adaptée au traitement de grands volumes de sols souillés par une pollution organique moyennement concentrée. Polycyclic aromatic hydrocarbons (PAHs can be found under natural conditions but they can be produced by pyrolysis processes. They can be found in former industrial sites subsoil, especially on Manufactured Gas Plant sites (MGP sites. Gaz de France has inherited the patrimony of former French gas companies on nationalisation in 1946; consequently, Gaz De France is still the owner of 467 of manufactured gas plants. Even if no impact on human health has been detected and even if the risks seem to be virtual, Gaz de France has to prevent any environmental consequence due to the possible presence of residues in the subsoil of the sites: a protocol has been signed with the French Ministry of Environment. Following the investigations on the site, a

  13. Reductive dechlorination of chlorinated ethenes by iron metal

    Energy Technology Data Exchange (ETDEWEB)

    Sivavec, T.M.; Horney, D.P. [GE Corp. Research and Development, Schenectady, NY (United States)

    1995-12-01

    Reduction of chlorinated ethenes in aqueous solution by iron metal was studied in batch and column systems under anaerobic and mildly aerobic conditions. The goal of this work was to gain a fundamental mechanistic understanding of the reaction chemistry and to determine the factors that affect dechlorination rate and long-term performance in groundwater treatment. Pseudo-first-order TCE, DCE and VC dechlorination rates and product mass balances (chloride ion and C2-C6 hydrocarbons) were measured for greater than twenty-five commercial iron metals. All experimental evidence was found to support a direct reduction mechanism in which electron transfer from Fe{sup o} to the adsorbed chloroethene occurs at the metal/water interface. XPS depth profile analysis was used to correlate Fe{sup o} surface concentration with observed dechlorination rates. A linear dependence of dechlorination rate on iron specific surface area was determined. Other factors that influence dechlorination rates will be discussed, including proton- and anion-promoted dissolution processes that remove surface iron oxides and yield new Fe{sup o} surfaces.

  14. Occupational Exposure to Chlorinated and Petroleum Solvents and Mycosis Fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M; Olsen, Jorn; Villeneuve, Sara

    2013-01-01

    To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF).......To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF)....

  15. Chlorine isotopes potential as geo-chemical tracers

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Pradhan, U.K.; Banerjee, R.

    The potential of chlorine isotopes as tracers of geo-chemical processes of earth and the oceans is highlighted based on systematic studies carried out in understanding the chlorine isotope fractionation mechanism, its constancy in seawater and its...

  16. Blends of caprolactam/caprolactone copolymers and chlorinated polymers

    NARCIS (Netherlands)

    Alberda van Ekenstein, G.O.R.; Deuring, H.; ten Brinke, G.; Ellis, T.S.

    The phase behaviour of blends of chlorinated polyethylene, polyvinyl chloride (PVC) and chlorinated PVC with random copolymers of caprolactone and caprolactam has been investigated and the results correlated with a binary interaction model. The known miscibility of polycaprolactone in the

  17. Effects of aging on chlorinated plasma polymers

    Energy Technology Data Exchange (ETDEWEB)

    Turri, Rafael Gustavo; Amorim, Milena Kowalczuk Manosso; Hadich, Tayan Vieira; Fernandes, Isabela Cristina; Fernandes, Gabriel Ferreira; Rossi, Diego; Rangel, Elidiane Cipriano; Durrant, Steven Frederick, E-mail: steve@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil). Lab. de Plasmas Tecnologicos

    2017-07-15

    Thin films deposited from propanol-chloroform-argon mixtures by plasma enhanced chemical vapor deposition at different partial pressures of chloroform in the feed, C{sub Cl}, were characterized after two years of aging and their characteristics compared with their as-deposited properties. Film thickness decreased and surface roughness increased with aging. Surface contact angles also increased with aging for the chlorinated films. For the film deposited with 40% chloroform in the feed the contact angle increased about 14°. Transmission infrared and Energy dispersive X-ray spectroscopy revealed that the films gain carbonyl and hydroxyl groups and lose chlorine and hydrogen on aging. Chlorination appears to make the films more durable. Delamination was observed for the unchlorinated films. (author)

  18. Chlorine: Undergraduate Research on an Element of Controversy

    Science.gov (United States)

    Chang, Hasok

    2009-04-01

    If chemical elements were people, chlorine would be a celebrity. Although intrinsically no more or less important than any other element, chlorine has had a knack of making headlines. The genre of "object biography" has been quite successful in popular science recently. We took this opportunity to write a "biographical" study of chlorine. Chlorine's wide range of interesting controversies is well suited for attracting and maintaining the enthusiasm of the diverse range of students we teach in our department.

  19. Comparative analysis of metagenomes from three methanogenic hydrocarbon-degrading enrichment cultures with 41 environmental samples

    Science.gov (United States)

    Tan, Boonfei; Jane Fowler, S; Laban, Nidal Abu; Dong, Xiaoli; Sensen, Christoph W; Foght, Julia; Gieg, Lisa M

    2015-01-01

    Methanogenic hydrocarbon metabolism is a key process in subsurface oil reservoirs and hydrocarbon-contaminated environments and thus warrants greater understanding to improve current technologies for fossil fuel extraction and bioremediation. In this study, three hydrocarbon-degrading methanogenic cultures established from two geographically distinct environments and incubated with different hydrocarbon substrates (added as single hydrocarbons or as mixtures) were subjected to metagenomic and 16S rRNA gene pyrosequencing to test whether these differences affect the genetic potential and composition of the communities. Enrichment of different putative hydrocarbon-degrading bacteria in each culture appeared to be substrate dependent, though all cultures contained both acetate- and H2-utilizing methanogens. Despite differing hydrocarbon substrates and inoculum sources, all three cultures harbored genes for hydrocarbon activation by fumarate addition (bssA, assA, nmsA) and carboxylation (abcA, ancA), along with those for associated downstream pathways (bbs, bcr, bam), though the cultures incubated with hydrocarbon mixtures contained a broader diversity of fumarate addition genes. A comparative metagenomic analysis of the three cultures showed that they were functionally redundant despite their enrichment backgrounds, sharing multiple features associated with syntrophic hydrocarbon conversion to methane. In addition, a comparative analysis of the culture metagenomes with those of 41 environmental samples (containing varying proportions of methanogens) showed that the three cultures were functionally most similar to each other but distinct from other environments, including hydrocarbon-impacted environments (for example, oil sands tailings ponds and oil-affected marine sediments). This study provides a basis for understanding key functions and environmental selection in methanogenic hydrocarbon-associated communities. PMID:25734684

  20. Aromatization process of hydrocarbons containing 2 to 4 carbon atoms in the presence of MFI structure zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Alario, F.; Deves, J.M.

    1993-05-21

    The invention describes an aromatization process of hydrocarbons comprising 2 to 4 carbon atoms per molecule in the presence of a composite catalyst which contains: a MFI structure zeolite containing an element chosen among alkaline or alkaline-earth metals, with a structure made of Silicon, Aluminium and / or Gallium; a matrix; platinum metals and additive metal chosen among Stain, Germanium, Indium, Copper, Iron, Molybdenum, Gallium, Thallium, Gold, Silver, Ruthenium, Chrome, Tungsten and Lead at least; an halogen chosen among Fluorine, Chlorine, Bromine and Iodine at least; Gallium and Zinc possibly; alkaline or alkaline-earth metal in the matrix preferentially. The invention describes also catalyst preparation and use for hydrocarbons aromatization reactions.

  1. Determination of chlorine in silicate rocks

    Science.gov (United States)

    Peck, L.C.

    1959-01-01

    In a rapid accurate method for the determination of chlorine in silicate rocks, the rock powder is sintered with a sodium carbonate flux containing zinc oxide and magnesium carbonate. The sinter cake is leached with water, the resulting solution is filtered, and the filtrate is acidified with nitric acid. Chlorine is determined by titrating this solution with mercuric nitrate solution using sodium nitroprusside as the indicator. The titration is made in the dark with a beam of light shining through the solution. The end point of the titration is found by visually comparing the intensity of this beam of light with that of a similar beam of light in a reference solution.

  2. Nontuberculous mycobacteria in the environment.

    Science.gov (United States)

    Falkinham, Joseph O

    2002-09-01

    It is likely that the incidence of infection by environmental opportunistic mycobacteria will continue to rise. Part of the rise will be caused by the increased awareness of these microbes as human pathogens and improvements in methods of detection and culture. Clinicians and microbiologists will continue to be challenged by the introduction of new species to the already long list of mycobacterial opportunists (see Table 3). The incidence of infection will also rise because an increasing proportion of the population is aging or subject to some type of immunosuppression. A second reason for an increase in the incidence of environmental mycobacterial infection is that these microbes are everywhere. They are present in water, biofilms, soil, and aerosols. They are natural inhabitants of the human environment, especially drinking water distribution systems. Thus, it is likely that everyone is exposed on a daily basis. It is likely that certain human activities can lead to selection of mycobacteria. Important lessons have been taught by study of cases of hypersensitivity pneumonitis associated with exposure to metalworking fluid. First, the implicated metalworking fluids contained water, the likely source of the mycobacteria. Second, the metalworking fluids contain hydrocarbons (e.g., pine oils) and biocides (e.g., morpholine) both of which are substrates for the growth of mycobacteria [53,193]. Third, outbreak of disease followed disinfection of the metalworking fluid [136,137]. Although the metalworking fluid was contaminated with microorganisms, it was only after disinfection that symptoms developed in the workers. Because mycobacteria are resistant to disinfectants, it is likely that the recovery of the mycobacteria from the metalworking fluid [137] was caused by their selection. Disinfection may also contribute, in part, to the persistence of M avium and M intracellulare in drinking water distribution systems [33,89,240]. M avium and M intracellulare are many times

  3. Investigating chloroperoxidase-catalyzed formation of chloroform from humic substances using stable chlorine isotope analysis.

    Science.gov (United States)

    Breider, Florian; Hunkeler, Daniel

    2014-01-01

    Chloroperoxidase (CPO) is suspected to play an important role in the biosynthesis of natural chloroform. The aims of the present study are to evaluate the variability of the δ(37)Cl value of naturally produced chloroform and to better understand the reaction steps that control the chlorine isotope signature of chloroform. The isotope analyses have shown that the chlorination of the humic substances (HS) in the presence of high H3O(+) and Cl(-) concentrations induces a large apparent kinetic isotope effect (AKIE = 1.010-1.018) likely associated with the transfer of chlorine between two heavy atoms, whereas in the presence of low H3O(+) and Cl(-) concentrations, the formation of chloroform induces a smaller AKIE (1.005-1.006) likely associated with the formation of an HOCl-ferriprotoporphyrin IX intermediate. As the concentration of H3O(+) and Cl(-) in soils are generally at submillimolar levels, the formation of the HOCl-ferriprotoporphyrin IX intermediate is likely rate-limiting in a terrestrial environment. Given that the δ(37)Cl values of naturally occurring chloride tend to range between -1 and +1‰, the δ(37)Cl value of natural chloroform should vary between -5‰ and -8‰. As the median δ(37)Cl value of industrial chloroform is -3.0‰, the present study suggests that chlorine isotopic composition of chloroform might be used to discriminate industrial and natural sources in the environment.

  4. The chlorination behaviour and environmental fate of the antiretroviral drug nevirapine in South African surface water.

    Science.gov (United States)

    Wood, Timothy Paul; Basson, Adriaan Erasmus; Duvenage, Cornelia; Rohwer, Egmont Richard

    2016-11-01

    The wastewater treatment process, besides discharging pharmaceuticals into the environment, has been found to result in the formation of a variety of undescribed compounds. Here we investigate the laboratory scale chlorination of the commonly used anti-HIV drug Nevirapine, characterise its disinfection transformation products (DTPs), and using liquid chromatography with high resolution mass spectrometry, screen environmental surface water for these DTPs. Chlorination of Nevirapine was scaled up, fractioned by preparative chromatography and the fractions were tested in vitro for toxicity and anti-HIV activity. Nevirapine was found to be resistant to degradation at relevant chlorination levels, which may partially explain its ubiquitous presence in South African surface water. During simulated chlorination, a variety of DTPs with varying properties were formed, some of which were detected in the environment, close to wastewater treatment plants. Interestingly, some of these compounds, although not as toxic as Nevirapine, retained antiviral activity. Further purification and synthesis is required to fully characterise these novel molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Rate of absorption and interfacial area of chlorine into aqueous ...

    African Journals Online (AJOL)

    aghomotsegin

    The rate of absorption predicted from developed model is compared with experimental results. They were in good agreement. ... are chlorine-water, chlorine-aqueous solution of alkaline carbonate, chlorine-aqueous alkaline ... Bulk concentration of an individual chemical species in liquid. Assuming all the reactions are at ...

  6. δ37Cl : the geochemistry of chlorine isotopes

    NARCIS (Netherlands)

    Eggenkamp, H.G.M.

    1994-01-01

    In this thesis the geochemistry of the stable isotopes of chlorine will be examined. Chlorine is one of the halogens, the seventh group in the periodic system of elements. This group consists of five elements, fluorine, chlorine, bromine, iodine, and astatine.

  7. 49 CFR 176.225 - Stowage of chlorine.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must be...

  8. Chlorine inactivation of mixed population versus indicator microorganism (poster)

    NARCIS (Netherlands)

    Peters, M.C.F.M.; Keuten, M.G.A.; Van Loosdrecht, M.C.M.; Rietveld, L.C.

    2013-01-01

    Chlorine is present in most swimming pools as residual disinfectant. In the Netherlands, the chlorine concentration in swimming pools has to be between 0.5-1.5 mg/L free available chlorine, which is based on a 4-log removal of Pseudomonas aeruginosa within 30 seconds. Besides disinfection of

  9. Efficiency of Chlorine Dioxide as a Bactericide1

    Science.gov (United States)

    Benarde, Melvin A.; Israel, Bernard M.; Olivieri, Vincent P.; Granstrom, Marvin L.

    1965-01-01

    We found chlorine dioxide to be a more effective disinfectant than chlorine in sewage effluent at pH 8.5. Chlorine dioxide was also found to be a more stable bactericide in relation to pH in the range studied. Images Fig. 1 PMID:5325940

  10. Effects of chlorine and temperature on yeasts isolatedfrom a soft ...

    African Journals Online (AJOL)

    Yeasts isolated from sugar and filling valves in a bottling process were exposed to different chlorine concentrations and various high temperatures. It was found that growth of yeasts decreased with increase in chlorine concentration. The maximum chlorine concentration that inhibited both types of yeasts was 60mg/l while ...

  11. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    OpenAIRE

    Jones, Robert MD; Wills, Brandon DO; Kang, Christopher MD

    2010-01-01

    Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. [West J Emerg Med. 2010; 11(2):151-156.

  12. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    Directory of Open Access Journals (Sweden)

    Jones, Robert MD

    2010-05-01

    Full Text Available Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. [West J Emerg Med. 2010; 11(2:151-156.

  13. Chlorine isotope effects and composition of naturally produced organochlorines from chloroperoxidases, flavin-dependent halogenases, and in forest soil.

    Science.gov (United States)

    Aeppli, Christoph; Bastviken, David; Andersson, Per; Gustafsson, Orjan

    2013-07-02

    The use of stable chlorine isotopic signatures (δ(37)Cl) of organochlorine compounds has been suggested as a tool to determine both their origins and transformations in the environment. Here we investigated the δ(37)Cl fractionation of two important pathways for enzymatic natural halogenation: chlorination by chloroperoxidase (CPO) and flavin-dependent halogenases (FDH). Phenolic products of CPO were highly (37)Cl depleted (δ(37)Cl = -12.6 ± 0.9‰); significantly more depleted than all known industrially produced organochlorine compounds (δ(37)Cl = -7 to +6‰). In contrast, four FDH products did not exhibit any observable isotopic shifts (δ(37)Cl = -0.3 ± 0.6‰). We attributed the different isotopic effect to the distinctly different chlorination mechanisms employed by the two enzymes. Furthermore, the δ(37)Cl in bulk organochlorines extracted from boreal forest soils were only slightly depleted in (37)Cl relative to inorganic Cl. In contrast to previous suggestions that CPO plays a key role in production of soil organochlorines, this observation points to the additional involvement of either other chlorination pathways, or that dechlorination of naturally produced organochlorines can neutralize δ(37)Cl shifts caused by CPO chlorination. Overall, this study demonstrates that chlorine isotopic signatures are highly useful to understand sources and cycling of organochlorines in nature. Furthermore, this study presents δ(37)Cl values of FDH products as well of bulk organochlorines extracted from pristine forest soil for the first time.

  14. UV/chlorine treatment of carbamazepine: Transformation products and their formation kinetics.

    Science.gov (United States)

    Pan, Yanheng; Cheng, ShuangShuang; Yang, Xin; Ren, Jingyue; Fang, Jingyun; Shang, Chii; Song, Weihua; Lian, Lushi; Zhang, Xinran

    2017-06-01

    Carbamazepine (CBZ) is one of the pharmaceuticals most frequently detected in the aqueous environment. This study investigated the transformation products when CBZ is degraded by chlorine under ultraviolet (UV) irradiation (the UV/chlorine process). Detailed pathways for the degradation of CBZ were elucidated using ultra-high performance liquid chromatography (UHPLC)-quadrupole time-of-flight mass spectrometry (QTOF-MS). CBZ is readily degraded by hydroxyl radicals (HO) and chlorine radicals (Cl) in the UV/chlorine process, and 24 transformation products were identified. The products indicate that the 10,11-double bond and aromatic ring in CBZ are the sites most susceptible to attack by HO and Cl. Subsequent reaction produces hydroxylated and chlorinated aromatic ring products. Four specific products were quantified and their evolution was related with the chlorine dose, pH, and natural organic matter concentration. Their yields showed an increase followed by a decreasing trend with prolonged reaction time. CBZ-10,11-epoxide (I), the main quantified transformation product from HO oxidation, was observed with a peak transformation yield of 3-32% depending on the conditions. The more toxic acridine (IV) was formed involving both HO and Cl with peak transformation yields of 0.4-1%. All four quantified products together amounted to a peak transformation yield of 34.5%. The potential toxicity of the transformation products was assayed by evaluating their inhibition of the bioluminescence of the bacterium Vibrio Fischeri. The inhibition increased at first and the decreased at longer reaction times, which was in parallel with the evolution of transformation products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Inactivation of three genera of dominant fungal spores in groundwater using chlorine dioxide: Effectiveness, influencing factors, and mechanisms.

    Science.gov (United States)

    Wen, Gang; Xu, Xiangqian; Huang, Tinglin; Zhu, Hong; Ma, Jun

    2017-11-15

    Fungi in aquatic environments received more attention recently; therefore, the characteristics of inactivation of fungal spores by widely used disinfectants are quite important. Nonetheless, the inactivation efficacy of fungal spores by chlorine dioxide is poorly known. In this study, the effectiveness of chlorine dioxide at inactivation of three dominant genera of fungal spores isolated from drinking groundwater and the effects of pH, temperature, chlorine dioxide concentration, and humic acid were evaluated. The inactivation mechanisms were explored by analyzing the leakage of intracellular substances, the increase in extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), and proteins as well as the changes in spore morphology. The kinetics of inactivation by chlorine dioxide fitted the Chick-Watson model, and different fungal species showed different resistance to chlorine dioxide inactivation, which was in the following order: Cladosporium sp.>Trichoderma sp. >Penicillium sp., which are much more resistant than Escherichia coli. Regarding the three genera of fungal spores used in this study, chlorine dioxide was more effective at inactivation of fungal spores than chlorine. The effect of disinfectant concentration and temperature was positive, and the impact of pH levels (6.0 and 7.0) was insignificant, whereas the influence of water matrices on the inactivation efficiency was negative. The increased concentration of characteristic extracellular substances and changes of spore morphology were observed after inactivation with chlorine dioxide and were due to cell wall and cell membrane damage in fungal spores, causing the leakage of intracellular substances and death of a fungal spore. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Les hydrocarbures aromatiques polycycliques dans l'environnement. Deuxième partie : La dégradation par voie microbienne Polycyclic Aromatic Hydrocarbons in the Environment. Part Two: Microbial Degradation

    Directory of Open Access Journals (Sweden)

    Bouchez M.

    2006-11-01

    Full Text Available La microbiologie de la dégradation des hydrocarbures aromatiques polycycliques (HAP est un domaine de recherche en plein développement. C'est à la fois le devenir dans l'environnement de ces composés ubiquistes et génotoxiques et l'utilisation de procédés microbiologiques de dépollution des sols industriels contaminés par ces produits qui motivent cet intérêt. On présente ici une synthèse des connaissances actuelles dans ce domaine. Les organismes dégradeurs sont essentiellement les bactéries et les champignons. Le processus de dégradation, aérobie, est initié par des oxygénases. Les bactéries utilisent les HAP de deux à quatre cycles comme substrats de croissance, ce qui conduit à leur minéralisation. Les champignons, lignolytiques et non lignolytiques, attaquent les HAP par cométabolisme, ce que font également les bactéries. L'ensemble des micro-organismes dégradant les HAP, et les voies métaboliques impliquées, sont présentés. Le mode d'accession des micro-organismes à leurs substrats très peu solubles est un point important. Les études menées avec les bactéries ont montré l'existence de deux mécanismes, le transfert par solubilisation dans la phase aqueuse et l'accession interfaciale directe. Un autre aspect présenté est le devenir des HAP, en termes de bilans carbone, lors de la dégradation bactérienne de HAP individuels et de mélanges de HAP. Des taux de minéralisation élevés peuvent être obtenus. Dans le cas des mélanges, ces taux élevés impliquent la mise en oeuvre de microflores complexes où le cométabolisme joue un rôle important. Les progrès accomplis ces dernières années conduisent à ne plus considérer les HAP comme des composés intrinsèquement récalcitrants à la biodégradation. Dans l'environnement, un facteur important limitant la dégradation des HAP est leur accessibilité aux micro-organismes. The microbiology of the degradation of polycyclic aromatic hydrocarbons

  17. Immobilization of chlorine dioxide modified cells for uranium absorption.

    Science.gov (United States)

    He, Shengbin; Ruan, Binbiao; Zheng, Yueping; Zhou, Xiaobin; Xu, Xiaoping

    2014-11-01

    There has been a trend towards the use of microorganisms to recover metals from industrial wastewater, for which various methods have been reported to be used to improve microorganism adsorption characteristics such as absorption capacity, tolerance and reusability. In present study, chlorine dioxide(ClO2), a high-efficiency, low toxicity and environment-benign disinfectant, was first reported to be used for microorganism surface modification. The chlorine dioxide modified cells demonstrated a 10.1% higher uranium adsorption capacity than control ones. FTIR analysis indicated that several cell surface groups are involved in the uranium adsorption and cell surface modification. The modified cells were further immobilized on a carboxymethylcellulose(CMC) matrix to improve their reusability. The cell-immobilized adsorbent could be employed either in a high concentration system to move vast UO2(2+) ions or in a low concentration system to purify UO2(2+) contaminated water thoroughly, and could be repeatedly used in multiple adsorption-desorption cycles with about 90% adsorption capacity maintained after seven cycles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Characterization of the reactivity and chlorinated products of carbazole during aqueous chlorination.

    Science.gov (United States)

    Xu, Xiong; Wang, Donghong; Li, Chunmei; Feng, Hongru; Wang, Zijian

    2017-06-01

    Carbazole in source water is a potential precursor for toxic chlorocarbazoles in drinking water when chlorine is used as a disinfection agent in drinking water treatment plants. However, the reactivity of carbazole and the specific structures and predominant analogues of chlorocarbazoles produced during aqueous chlorination remain unknown. In this study, the aqueous chlorination of carbazole was performed to characterize its reactivity and the chlorinated products. Chlorocarbazoles generated from carbazole were identified by a comprehensive two-dimensional gas chromatography-mass spectrometry method, and their molecular structures were predicted by the Fukui index of electrophilic attack, f-1(r). As a result, the comprehensive chlorination pathway of carbazole was extrapolated with a total of nine chlorocarbazoles identified, including two monochlorocarbazoles (3-chlorocarbazole and 1-chlorocarbazole), four dichlorocarbazoles (3,6-dichlorocarbazole, 1,6-dichlorocarbazole, 1,3-dichlorocarbazole and 1,8-dichlorocarbazole), two trichlorocarbazoles (1,3,6-trichlorocarbazole and 1,3,8-trichlorocarbazole) and one tetrachlorocarbazole (1,3,6,8-tetrachlorocarbazole). The f-1(r) value indicates that the C1, C3, C6 and C8 atoms of carbazole were the favored positions for electrophilic attack, with the C3 and C6 atoms being the predominant sites for chlorine substitution. 3-Chlorocarbazole, 3,6-dichlorocarbazole, 1,3,6-trichlorocarbazole and 1,3,6,8-tetrachlorocarbazole were the major analogues of each chlorocarbazole group; however, the production of minor analogues such as 1-chlorocarbazole and 1,6-dichlorocarbazole should not be overlooked. The chlorination of carbazole was a pseudo first order reaction with a reaction rate of 0.1836 nmol/(L· h) and half-life of 3.77 h (pH = 6.4, Cl2 = 4.7 mg/L), and the chlorination rate of carbazole was approximately 5 times faster than that of an known chlorination precursor pyrene. These results showed that Fukui index was

  19. Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts.

    Science.gov (United States)

    Tsai, Wen-Tien

    2017-09-21

    Among the halogenated hydrocarbons, chloromethanes (i.e., methyl chloride, CH₃Cl; methylene chloride, CH₂Cl₂; chloroform, CHCl₃; and carbon tetrachloride, CCl₄) play a vital role due to their extensive uses as solvents and chemical intermediates. This article aims to review their main chemical/physical properties and commercial/industrial uses, as well as the environment and health hazards posed by them and their toxic decomposition products. The environmental properties (including atmospheric lifetime, radiative efficiency, ozone depletion potential, global warming potential, photochemical ozone creation potential, and surface mixing ratio) of these chlorinated methanes are also reviewed. In addition, this paper further discusses their atmospheric fates and human health implications because they are apt to reside in the lower atmosphere when released into the environment. According to the atmospheric degradation mechanism, their toxic degradation products in the troposphere include hydrogen chloride (HCl), carbon monoxide (CO), chlorine (Cl₂), formyl chloride (HCOCl), carbonyl chloride (COCl₂), and hydrogen peroxide (H₂O₂). Among them, COCl₂ (also called phosgene) is a powerful irritating gas, which is easily hydrolyzed or thermally decomposed to form hydrogen chloride.

  20. CONCERNS OF CONTEMPORARY DISINFECTION: CHLORINE OR STABILIZED LIQUID SOLUTION OF CHLORINE DIOXIDE

    OpenAIRE

    Abdulah Gagić; Selma Selimović; Suad Jukić; Ajla Ališah; Aida Kustura

    2014-01-01

    It is common that experts use routine procedures for disinfection. Every part of the disinfection procedure is routinely done: preparation of the disinfection media, selection of the type of disinfection, protective measures, effect control and environmental issues. This article offers a new insight into the use of stabilized liquid chlorine dioxide as a qualitative alternative disinfectant for wider application by comparing it to the most frequently used chlorine and its compounds. When used...

  1. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  2. Halogenase‐Inspired Oxidative Chlorination Using Flavin Photocatalysis

    Science.gov (United States)

    Hering, Thea; Mühldorf, Bernd

    2016-01-01

    Abstract Chlorine gas or electropositive chlorine reagents are used to prepare chlorinated aromatic compounds, which are found in pharmaceuticals, agrochemicals, and polymers, and serve as synthetic precursors for metal‐catalyzed cross‐couplings. Nature chlorinates with chloride anions, FAD‐dependent halogenases, and O2 as the oxidant. A photocatalytic oxidative chlorination is described based on the organic dye riboflavin tetraacetate mimicking the enzymatic process. The chemical process allows within the suitable arene redox potential window a broader substrate scope compared to the specific activation in the enzymatic binding pocket. PMID:26991557

  3. Turbidity and chlorine demand reduction using alum and moringa flocculation before household chlorination in developing countries.

    Science.gov (United States)

    Preston, Kelsey; Lantagne, Daniele; Kotlarz, Nadine; Jellison, Kristen

    2010-03-01

    Over 1.1 billion people in the world lack access to improved drinking water. Diarrhoeal and other waterborne diseases cause an estimated 1.87 million deaths per year. The Safe Water System (SWS) is a household water treatment intervention that reduces diarrhoeal disease incidence among users in developing countries. Turbid waters pose a particular challenge to implementation of SWS programmes; although research shows that a 3.75 mg l(-1) sodium hypochlorite dose effectively treats turbid waters, users sometimes object to the strong chlorine taste and prefer to drink water that is more aesthetically pleasing. This study investigated the efficacy of two locally available chemical water treatments-alum and Moringa oleifera flocculation-to reduce turbidity and chlorine demand at turbidities of 10, 30, 70, 100 and 300 NTU. Both treatments effectively reduced turbidity (alum flocculation 23.0-91.4%; moringa flocculation 14.2-96.2%). Alum flocculation effectively reduced chlorine demand compared with controls at 30, 70, 100 and 300 NTU (p=0.01-0.06). Moringa flocculation increased chlorine demand to the point where adequate free chlorine residual was not maintained for 24 hours after treatment. Alum pretreatment is recommended in waters>or=30 NTU for optimum water disinfection. Moringa flocculation is not recommended before chlorination.

  4. Chlorinated aromatics from combustion: influence of chlorine, combustion conditions, and catalytic activity.

    Science.gov (United States)

    Oberg, T; Ohrström, T

    2003-09-01

    Research on the formation of chlorinated aromatics in combustion processes has mainly taken place in the laboratory. Previous attempts to correlate observation data from commercial plants have been inconclusive. This study reports on the outcome of an industrial experiment in a full-scale afterburner. The influence of chlorine input, combustion temperature, and catalytic activity was investigated in a factorial design with two blocks. Polychlorinated benzenes, dibenzo-p-dioxins, and dibenzofurans were formed both at combustion temperatures and below 400 degrees C. The results show that all three experimental factors have statistically significant impact on the formation and release of these toxic byproducts. The quantitative dependence between chlorine input and the occurrence of chlorinated aromatics is of particular interest due to previous controversy. The purpose with this study was to ensure that the installation of a boiler for energy recovery would not cause elevated emissions of chlorinated aromatics. The experiment demonstrated that this risk is probably low, since the presence of catalytic material or an increase in chlorine input is required for this to happen. A general conclusion was that industrial experimentation employing the principles of statistical design could improve the validity in recommendations regarding commercial plant operation.

  5. Source Characterization of Polycyclic Aromatic Hydrocarbons by Using Their Molecular Indices: An Overview of Possibilities

    NARCIS (Netherlands)

    Stogiannidis, E.; Laane, R.

    2014-01-01

    The Polycyclic Aromatic Hydrocarbons (PAHs or polyaromatic hydrocarbons) have been extensively studied to understand their distribution, fate and effects in the environment (Haftka 2009; Laane et al. 1999, 2006, 2013; Okuda et al. 2002; Page et al. 1999; Pavlova and Ivanova 2003; Stout et al. 2001a;

  6. Hydrocarbon distribution in the Irati shale oil

    Energy Technology Data Exchange (ETDEWEB)

    Afonso, J.C.; Schmal, M.; Cardoso, J.N. [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)

    1994-03-01

    This work reports a detailed characterization of the various hydrocarbon structures present in a sample of the Irati shale oil (Sao Mateus do Sul, Parana), obtained by the Petrosix Process, by means of a combination of gas chromatography-mass spectrometry (g.c.-m.s.), co-injection with authentic standards, and retention time data of model compounds. Hydrocarbon structures, the main constituents of the shale oil ({approximately} 38 wt%), include: linear, branched and isoprenoidal alkanes, linear and isoprenoidal alkenes, alkycyclopentanes and cyclohexanes, alkylcycloalkenes, hopanes, hopenes and steranes. Linear structures are dominant (43% of the total hydrocarbons), followed by isoprenoidal skeletons. Saturated compounds strongly predominate over their unsaturated counterparts. The use of several maturity parameters attested to the immaturity of the sediment. Data further suggested a predominant algal/microbial origin and a basic lacustrine depositional environment to the Irati shale, probably under a moderate oxidative condition, thus confirming previous conclusions obtained via analysis of the Irati bitumen and the shale rock. Additionally, the data confirmed the usual classification of this shale as containing Type-II kerogen. 34 refs., 2 tabs.

  7. Solo Mycoremediation Impacted by Waste Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Franklin Santos Freire

    2015-06-01

    Full Text Available Oil and its derivatives are the principal means of energy generation for vehicles that transport raw materials and goods produced in developed and developing regions accentuating the risk of accidents by spills in stockpiling, transport, use or discarding. The contamination by total hydrocarbons suggests the elevated propension to mutations and to the formation of carcinogenic tumors, as a consequence of the exposure to human contamination by these products. This work had as aims: a To investigate, in a laboratorial scale, the degrading capacity of autochthonous microbiota in the presence of differing concentrations of hydrocarbons (0%, 2,5%, 5% e 7,5%; b To isolate fungi tolerant to the contaminant; c To quantify and analyze the biodegradation capacity of soil through the microbial biomass and metabolic quotient; and d To set, in laboratory, ideal conditions of biodegradation of the xenobiotic compound. Some parameters of microbial activity have been evaluated, such as: biological (Carbon of microbial biomass, CO2 , qCO2 emission, and fungi growth, chemical (pH, electrical conductivity –EC –, analysis of fertility and total hydrocarbons and physical (physical composition of the soil for analysis and comparisons. The obtained results suggest that the adding of 5% of waste oil in the ground provided ideal condition for the biodegradation of he   contaminant in the environment. From the evaluated parameters, the emission of CO2 and microbial C were considered more indicative of changes in soil microbial activity subject to the addition of hydrocarbons, confirming the possibility of microremediation use.

  8. Sedimentary facies and lithologic characters as main factors controlling hydrocarbon accumulations and their critical conditions

    Directory of Open Access Journals (Sweden)

    Jun-Qing Chen

    2015-10-01

    Full Text Available Taking more than 1000 clastic hydrocarbon reservoirs of Bohai Bay Basin, Tarim Basin and Junggar Basin, China as examples, the paper has studied the main controlling factors of hydrocarbon reservoirs and their critical conditions to reveal the hydrocarbon distribution and to optimize the search for favorable targets. The results indicated that the various sedimentary facies and lithologic characters control the critical conditions of hydrocarbon accumulations, which shows that hydrocarbon is distributed mainly in sedimentary facies formed under conditions of a long-lived and relatively strong hydrodynamic environment; 95% of the hydrocarbon reservoirs and reserves in the three basins is distributed in siltstones, fine sandstones, lithified gravels and pebble-bearing sandstones; moreover, the probability of discovering conventional hydrocarbon reservoirs decreases with the grain size of the clastic rock. The main reason is that the low relative porosity and permeability of fine-grained reservoirs lead to small differences in capillary force compared with surrounding rocks small and insufficiency of dynamic force for hydrocarbon accumulation; the critical condition for hydrocarbon entering reservoir is that the interfacial potential in the surrounding rock (Φn must be more than twice of that in the reservoir (Φs; the probability of hydrocarbon reservoirs distribution decreases in cases where the hydrodynamic force is too high or too low and when the rocks have too coarse or too fine grains.

  9. Insight into heterogeneity in cell-surface hydrophobicity and ability to degrade hydrocarbons among cells of two hydrocarbon-degrading bacterial populations

    Energy Technology Data Exchange (ETDEWEB)

    Obuekwe, C.O.; Al-Jadi, Z.K.; Al-Saleh, E. [Kuwait Univ., Safat (Kuwait). Dept. of Biological Sciences

    2007-02-15

    Petroleum consists of a complex mixture of hydrocarbons and related compounds, of which the physical and chemical characteristics and biodegradability vary considerably. Large amounts of petroleum products are released into the environment from natural sources, production and transport. Because of their hydrophobic nature, the use, and therefore the removal of hydrocarbon contaminants from the environment with microbial activities are prevented by the relative insolubility of hydrocarbons in aqueous systems. Bacterial adherence to hydrocarbons (BATH) and fractionations of bacterial cell suspensions suggest the existence of two basic groups of bacterial variants, namely hydrophobic and hydrophilic. This article presented the results of a study that fractionated the hydrophobic bacterial fraction in order to better understand the heterogeneity of hydrophobic characteristics in a natural population, and determine how such differences affect the ability of variants to use hydrocarbons. The materials and methods used in the study were discussed with reference to the organisms; production of hydrophobic and hydrophilic variants; storage of cultures; cultural techniques; characterization of cell fractions; hydrocarbon degradation; recovery of residual hydrocarbons and analysis; and, identification of organisms. The results of the study were presented in terms of the effects of fractionation of successive generations of hydrophobic bacterial cultures and degradation of hydrocarbon substrates. 29 refs., 1 tab., 5 figs.

  10. Hydrocarbons on harvester ant (Pogonomyrmex barbatus) middens guide foragers to the nest.

    Science.gov (United States)

    Sturgis, Shelby J; Greene, Michael J; Gordon, Deborah M

    2011-05-01

    Colony-specific cuticular hydrocarbons are used by social insects in nestmate recognition. Here, we showed that hydrocarbons found on the mound of Pogonomyrmex barbatus nests facilitate the return of foragers to the nest. Colony-specific hydrocarbons, which ants use to distinguish nestmates from non-nestmates, are found on the midden pebbles placed on the nest mound. Midden hydrocarbons occur in a concentration gradient, growing stronger near the nest entrance, which is in the center of a 1-2 m diameter nest mound. Foraging behavior was disrupted when the gradient of hydrocarbons was altered experimentally. When midden material was diluted with artificial pebbles lacking the colony-specific hydrocarbons, the speed of returning foragers decreased significantly. The chemical environment of the nest mound contributes to the regulation of foraging behavior in harvester ants.

  11. Formation of chlorinated organic compounds in fluidized bed combustion of recycled fuels; Kloorattujen orgaanisten yhdisteiden muodostuminen kierraetyspolttoaineiden leijukerrospoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Vesterinen, R.; Kallio, M.; Kirjalainen, T.; Kolsi, A.; Merta, M. [VTT Energy, Jyvaeskylae (Finland)

    1997-10-01

    Four tests of co-combustion of recycled fuels (REP) with peat and coal in the 15 kW fluidized bed reactor were performed. The recycled fuel was so-called dry fraction in four vessels sampling at Keltinmaeki. In three tests a part of peat energy was replaced with coal. The mixtures were prepared so that in all mixtures 25 % of energy was recycled fuel and 75 % was either peat or the mixture of peat and coal. The concentrations of polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and chlorophenols decreased with increasing part of coal due to the increasing sulphur/chlorine ratio. Principal Component Analysis (PCA) and Partial Least Square regression analysis (PLS) showed that the chlorine, copper and sulphur contents of the fuel effected most on the concentrations of chlorophenols, chlorobenzenes, PCBs and PCDDs/PCDFs. Other variables influencing on a model were the lead concentration and the sulphur/chlorine ratio in fuel and the hydrogen chloride concentration of the flue gas. The concentrations of chlorophenols and chlorobenzenes were also significant for PCDD/PCDF concentrations in flue gas. The sulphur, chlorine, copper and chromium contents in fly ash and the temperature of the reactor influenced on the chlorophenol, chlorobenzene, PCB and PCDD/PCDF concentrations in fly ash. The chlorophenol and chlorobenzene contents in fly ash, the sulphur/chlorine ratio and the lead content in fuel, the sulphur dioxide, hydrogen chloride and carbon monoxide concentrations in flue gas had also influence on PCDD/PCDF concentrations in fly ash

  12. Optimal intervention strategies for cholera outbreak by education and chlorination

    Science.gov (United States)

    Bakhtiar, Toni

    2016-01-01

    This paper discusses the control of infectious diseases in the framework of optimal control approach. A case study on cholera control was studied by considering two control strategies, namely education and chlorination. We distinct the former control into one regarding person-to-person behaviour and another one concerning person-to-environment conduct. Model are divided into two interacted populations: human population which follows an SIR model and pathogen population. Pontryagin maximum principle was applied in deriving a set of differential equations which consists of dynamical and adjoin systems as optimality conditions. Then, the fourth order Runge-Kutta method was exploited to numerically solve the equation system. An illustrative example was provided to assess the effectiveness of the control strategies toward a set of control scenarios.

  13. Compound-specific chlorine isotope analysis of polychlorinated biphenyls isolated from Aroclor and Clophen technical mixtures.

    Science.gov (United States)

    Mandalakis, Manolis; Holmstrand, Henry; Andersson, Per; Gustafsson, Orjan

    2008-03-01

    Compound-specific chlorine isotope analysis (CSIA-Cl) is promising as a novel and powerful method for monitoring in situ degradation of organochlorines in the environment and for source fingerprinting purposes. In order to apply CSIA-Cl in field studies of polychlorinated biphenyls (PCBs), the chlorine isotopic composition (delta(37)Cl) of individual PCB congeners in source materials must be known. In the present study, we determined delta(37)Cl of 18 congeners isolated from three widely produced technical mixtures. All congeners provided delta(37)Cl ranging between -1.9 per thousand and -3.5 per thousand. Although the comparable products Aroclor 1242 (-2.0 per thousand to -2.5 per thousand) and Clophen A30 (-1.9 per thousand to -3.0 per thousand) were synthesized by different industries, they provided similar delta(37)Cl for the same type of congeners. On the contrary, the more chlorinated congeners present in Aroclor 1254 (-2.1 to -3.5 per thousand) were more (37)Cl depleted compared to Aroclor 1242 manufactured by the same company. Overall, delta(37)Cl of PCB congeners decreased by -0.26 per thousand for each additional chlorine atom.

  14. Effects of ozone and chlorine disinfection on VBNC Helicobacter pylori by molecular techniques and FESEM images.

    Science.gov (United States)

    Orta de Velásquez, María Teresa; Yáñez Noguez, Isaura; Casasola Rodríguez, Beatriz; Román Román, Priscila Ivette

    2017-03-01

    Helicobacter pylori is a pathogen bacteria associated with chronic gastritis, peptic ulceration, and gastric carcinoma. H. pylori has a spiral morphology, which under certain conditions of stress becomes a coccoid form. This type of morphology has been linked to a viable but non-culturable (VBNC) state, which is thought to allow its persistence in the environment. Membrane damage in VBNC H. pylori in water as a mechanism for inactivation using ozone (O3) and chlorine disinfection has not been reported in the literature. In this paper, disinfection assays with ozone and chlorine were conducted to evaluate their effects on VBNC H. pylori cells. The use of fluorescent dyes such as propidium monoazide (PMA) coupled with quantitative real-time polymerase chain reactions produced results necessary to assess the viability of the microorganism and demonstrate the effect of each disinfectant on the bacterial count. Applying ozone showed a 5-log bacterial reduction using a disinfectant concentration and exposure time (CT) of 4 mg min/L. Chlorine disinfection for the same 5-log reduction required a higher CT value. Field emission scanning electron microscope images of ozone-treated VBNC H. pylori also showed severe cell damage. The use of PMA revealed that chlorine produced physical damage in the membrane in addition to the known inhibiting effect on cell enzymatic processes. These findings are important for the detection and control of VBNC H. pylori cells in drinking water systems.

  15. Simultaneous Recovery of Hydrogen and Chlorine from Industrial Waste Dilute Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    N. Paidimarri

    2016-01-01

    Full Text Available Recovery of chlorine from byproduct HCl has inevitable commercial importance in industries lately because of insufficient purity or too low concentration to recycle it. Instead it is being neutralized in industries before disposing to meet stringent environmental conditions. Although recovery through catalytic oxidation processes is studied since the 19th century, their high operating conditions combined with sluggish reaction kinetics and low single pass conversions make electrolysis a better alternative. The present motive of this work is to develop a novel electrolysis process which in contrast to traditional processes effectively recovers both hydrogen and chlorine from dilute HCl. For this, an electrolytic cell with an Anionic Exchange Membrane has been designed which only allows the passage of chlorine anions from catholyte to anolyte separating the gasses in a single step. The catholyte can be as low as 3.59 wt% because of fixed anolyte concentration of 1.99 wt% which minimizes oxygen formation. Preliminary results show that the simultaneous recovery of hydrogen and chlorine is possible with high conversion up to 98%. The maximum current density value for 4.96 cm2 membrane surface area (70% active surface area is 2.54 kAm−2, which is comparable with reported commercial processes. This study is expected to be useful for process intensification of the same in a continuous process environment.

  16. Chlorine leak on Mumbai port trust′s Sewri yard: A case study

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Sharma

    2010-01-01

    Full Text Available Chemical emergencies involving hazardous chemicals are not uncommon in India. More than 25 incidents have been identified in National Disaster Management Guidelines - Chemical (Industrial Disaster Management, released in May 2007. In a recent occurrence on the morning of 14 July 2010, nearly at 3:00 a.m., chlorine leak was reported from a gas cylinder referred as turner, weighing about 650 kg, corroding with time at the Haji Bunder hazardous cargo warehouse in Mumbai Port Trust, Sewri, affecting over 120 people in the neighborhood, including students, laborers, port workers and fire fighters, of whom 70 were reported critical. It has been observed to be a blatant case of ignorance and negligence as well as contraventions to the safety and environmental safeguard requirements under existing statues as well as non-maintenance of failsafe conditions at the site requisite for chlorine storage. The analysis revealed significant gaps in the availability of neutralization mechanism and the chlorine stored in open increased the possibility of formation of ingress mixture due to busting of chlorine filled tankers. The Government of India has institutionalized emergency preparedness framework at national, state and district level as envisaged in Disaster Management Act, 2005, to prepare the nation to mitigate such incidences, if all the preventive safety provisions fail. Ministry of Environment and Forests (MoEF is preparing National Action Plan-Chemical (Industrial Disaster Management based on National Guidelines to implement all the mechanisms of capacity development across the country.

  17. Chlorine hazard evaluation for the zinc-chlorine electric vehicle battery. Final technical report. [50 kWh

    Energy Technology Data Exchange (ETDEWEB)

    Zalosh, R. G.; Bajpai, S. N.; Short, T. P.; Tsui, R. K.

    1980-04-01

    Hazards associated with conceivable accidental chlorine releases from zinc-chlorine electric vehicle batteries are evaluated. Since commercial batteries are not yet available, this hazard assessment is based on both theoretical chlorine dispersion models and small-scale and large-scale spill tests with chlorine hydrate (which is the form of chlorine storage in the charged battery). Six spill tests involving the chlorine hydrate equivalent of a 50-kWh battery indicate that the danger zone in which chlorine vapor concentrations intermittently exceed 100 ppM extends at least 23 m directly downwind of a spill onto a warm (30 to 38/sup 0/C) road surface. Other accidental chlorine release scenarios may also cause some distress, but are not expected to produce the type of life-threatening chlorine exposures that can result from large hydrate spills. Chlorine concentration data from the hydrate spill tests compare favorably with calculations based on a quasi-steady area source dispersion model and empirical estimates of the hydrate decomposition rate. The theoretical dispersion model was combined with assumed hydrate spill probabilities and current motor vehicle accident statistics in order to project expected chlorine-induced fatality rates. These calculations indicate that expected chlorine fataility rates are several times higher in a city such as Los Angeles with a warm and calm climate than in a colder and windier city such as Boston. Calculated chlorine-induced fatality rate projections for various climates are presented as a function of hydrate spill probability in order to illustrate the degree of vehicle/battery crashworthiness required to maintain chlorine-induced fatality rates below current vehicle fatality rates due to fires and asphyxiations. 37 figures, 19 tables.

  18. Formation and speciation of haloacetamides and haloacetonitriles for chlorination, chloramination, and chlorination followed by chloramination.

    Science.gov (United States)

    Huang, Huang; Chen, Bo-Yi; Zhu, Zi-Ru

    2017-01-01

    The formation of haloacetamides (HAcAms) and haloacetonitriles (HANs) from a solution containing natural organic matter and a secondary effluent sample was evaluated for disinfection by chlorination, chloramination, and chlorination followed by chloramination (Cl2NH2Cl process). The use of preformed monochloramine (NH2Cl) produced higher concentrations of HAcAms and lower concentrations of HANs than chlorination, while the Cl2NH2Cl process produced the highest concentrations of HAcAms and HANs. These results indicate that the Cl2NH2Cl process, which inhibited the formation of regulated trihalomethanes compared with chlorination, enhanced the formation of HAcAms and HANs. For disinfection in the presence of bromide, brominated dihaloacetamides and dihaloacetonitriles were formed, and the trends were similar to those observed for chlorinated species in the absence of bromide. The degrees of bromine substitution of dihaloacetamides and dihaloacetonitriles were highest for chlorination, followed by the Cl2NH2Cl process and then by the NH2Cl process. For the Cl2NH2Cl process, HAN formation kept gradually increasing with prechlorination time increasing from 0 to 120 min, while HAcAm formation increased only until it reached a maximum at around 10-30 min. These results suggest that the prechlorination time could be reduced to control the formation of HAcAms and HANs. During chloramination, the formation of HAcAms and HANs was lower when using preformed NH2Cl than when chloramines were formed in situ, with higher formation of HAcAms and HANs when chlorine was added before ammonia than vice versa for the secondary effluent; this finding suggests that preformed NH2Cl could be used to inhibit the formation of HAcAms and HANs during chloramination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Quantification of temperature impacts on the dissolution of chlorinated hydrocarbons into groundwater

    Science.gov (United States)

    Koproch, Nicolas; Popp, Steffi; Köber, Ralf; Beyer, Christof; Bauer, Sebastian; Dahmke, Andreas

    2016-04-01

    Shallow thermal energy storage has great potential for heat storage especially in urban and industrial areas. However, frequently existing organic groundwater contaminations in such areas were currently seen as exclusion criteria for thermal use of the shallow subsurface, since increased contaminant discharge is feared as consequence of heating. Contaminant discharge is influenced by a complex interaction of processes and boundary conditions as e.g. solubility, dispersion, viscosity and degradation, where there is still a lack of experimental evidence of the temperature dependent interaction. Even existing studies on basic influencing factors as e.g. temperature dependent solubilities show contradictory results. Such knowledge gaps should be reduced to improve the basis and liability of numerical model simulations and the knowledge base to enable a more differentiated and optimized use of resources. For this purpose batch as well as 1- and 2-dimensional experimental studies concerning the temperature dependent release of TCE (trichloroethylene) from a NAPL (non aqueous phase liquid) source are presented and discussed. In addition, this experimental studies are accompanied by a numerical model verification, where extensions of existing numerical model approaches on basis of this obtained experimental results are developed. Firstly, temperature dependent TCE solubility data were collected using batch experiments with significantly better temperature resolution compared to earlier studies, showing a distinct minimum at 35°C and increased solubility towards 5°C and 70°C. Secondly, heated 1-dimensional stainless steel columns homogenously filled with quartz sand were used to quantify source zone depletion and contaminant discharge at 10-70°C. Cumulative mass discharge curves indicated two blob categories with distinct differences in dissolution kinetics. Increasing the temperature showed here an increase of the amount of fast dissolving blobs indicating higher NAPL-water contact areas. Thirdly, heatable 2D-tanks (40 cm x 25 cm x 10 cm) homogenously filled with quartz sand and percolated by distilled H2O were used to investigate the dissolution behavior and plume development of TCE from a residual source zone (5 cm x 5 cm x 10 cm) at 10-70°C. Using NAPL source zone saturation of 5% (Case A) and 20% (Case B) two exemplary cases of a depleted and a fresh source zone were investigated. TCE outflow concentrations in case A increased continuously with increasing temperature, but were controlled by the temperature-dependent solubility in Case B. The experimental results showed that the TCE mass transfer rate has a minimum at about 40°C, if dissolution is non-rate limited and a continuous increase with increasing temperature for rate-limited systems. Implementation of temperature dependent NAPL dissolution and two different blob categories with different mass transfer rate coefficients in the OpenGeoSys code proved successful in reproducing the experimental results. Acknowledgments: The presented work is part of the ANGUS+ project (03EK3022) funded by the German Ministry of Education and Research (BMBF).

  20. Technical Protocol for Using Soluble Carbohydrates to Enhance Reductive Dechlorination of Chlorinated Aliphatic Hydrocarbons

    Science.gov (United States)

    2002-12-19

    Demonstration USEPA CVOCs Large-Scale Pilot underway 41 Palatine IL Metal Plating Facility Illinois EPA CVOCs and Cr+6 Pilot 1998-1999; Full-Scale...year (3.1 to 21.3 meters per year). The bedrock is primarily fractured along horizontal bedding planes that strike to the northwest with a slight...bedding plane partings that are coincident with the strike of the rock. Groundwater flow is generally south-southeast with the orientation of the

  1. Chlorinated hydrocarbons and polybrominated diphenyl ethers in glaucous gulls (Larus hyperboreus) from Barentsburg (West Spitsbergen)

    Energy Technology Data Exchange (ETDEWEB)

    Savinov, V.; Savinova, T. [Akvaplan-niva Polar Environmental Centre, Tromso (Norway); Muir, D. [National Water Research Inst., Burlington, ON (Canada); Gabrielsen, G.W. [Norwegian Polar Inst., Tromso (Norway); Alexeeva, L. [SPA Typhoon, Obninsk (Russian Federation); Marasaev, S.; Zyryanov, S. [Murmansk Marine Biological Inst., Murmansk (Russian Federation)

    2005-07-01

    Glaucous gulls are vulnerable to contaminant exposure in the Arctic due to their low metabolic activity. This paper provided details of a study that analyzed the tissues of a number of glaucous gulls recently found dead in the Svalbard region. Liver samples were analyzed for organochlorine; polychlorinated biphenyls (PCBs); DDT; chlorobenzenes (CBz); hexachlorohexanes (HCH); chlordane-related compounds (CHL); endosulfanes; endrine; methoxychlor; mirex; toxaphenes; and polybrominated diphenyl ethers (PBDEs). Toxic equivalency factors were used to calculate levels of PCBs. Factor analysis was used to obtain the correlation structure of contaminant concentrations. Lipid base log-transformed contaminant concentrations were used to obtain a Spearman rank order correlation and factor analyses. Results showed that PCBs, DDT, CBz, and CHL were the most abundant persistent contaminants in the hepatic tissues of both male and female glaucous gulls. PBDE hepatic concentrations in female and male glaucous gulls ranged from 3.5 to 100 ng/g ww and 6.1 to 27 ng/g ww. The factor analysis showed that the 4 main contaminants found in the gulls accounted for 75.6 per cent of the total variance found. It was concluded that deca-BDE was the most abundant PBDE congener, which reflected current widespread use of brominated flame retardants in the region. 8 refs., 1 tab., 3 figs.

  2. Penetrometer compatible, fiber-optic sensor for continuous monitoring of chlorinated hydrocarbons -- field test results

    Energy Technology Data Exchange (ETDEWEB)

    Milanovich, F.P.; Brown, S.B.; Colston, B.W. Jr.

    1993-04-01

    We have developed and field tested a fiber optic chemical sensor for use in environmental monitoring and remediation. The principle of detection is colorimetric and is based on an irreversible chemical reaction between a specific reagent and the target compound. The formation of reaction products are monitored remotely with optical fibers. Successive or on-demand measurements are made possible with a reagent reservoir and a miniature pumping system. The sensor has been evaluated against gas chromatography standards and has demonstrated accuracy and sensitivity (>5ppb w/w) sufficient for the environmental monitoring of the contaminants triceoroethlyene (TCE) and chloroform. The sensor system can be used for bench-top analyses or for in-situ measurements such as groundwater and vadose monitoring wells or in Penetrometry mediated placements.

  3. Occurrence and distribution of persistent chlorinated hydrocarbons in the seas around India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    Article deals with an evaluation of the levels of contamination of various organochlorine pesticides such as DDTs, HCHs, aldrin, dieldrin, endrin, and different congeners of polychlorinated biphenyls in different compartment of the ocean (water...

  4. Temperature Dependence of the Inhibition of Positronium by Chlorine- Substituted Hydrocarbons in Non-Polar Liquids

    DEFF Research Database (Denmark)

    Wikander, G.; Mogensen, O.E.; Pedersen, Niels Jørgen

    1984-01-01

    Positron annihilation lifetime spectra were measured for solutions of 1,2,3,5-C6H2Cl4 in hexane, toluene, m-xylene and mesitylene, CCl4 in hexane and toluene, and C2HCl3 in n-hexane for concentrations below 1 M and at various temperatures between −30°C and 67°C. The Ps inhibition by C6H2Cl4 was r...

  5. Persistent synthetic chlorinated hydrocarbons in albatross tissue samples from Midway Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Jones, P.D.; Hannah, D.J.; Buckland, S.J. [ESR:Environmental, Lower Hutt (New Zealand)] [and others

    1996-10-01

    Anthropogenic organic contaminants have been found in even the most remote locations. To assess the global distribution and possible effects of such contaminants, the authors examined the tissues of two species of albatross collected from Midway Atoll in the central North Pacific Ocean. These birds have an extensive feeding range covering much of the subtropical and northern Pacific Ocean. Anthropogenic contaminants were found at relatively great concentrations in these birds. The sum of 19 polychlorinated biphenyl (PCB) congeners ranged from 177 ng/g wet weight in eggs to 2,750 ng/g wet weight in adult fat. Total toxic equivalents (TEQs) derived from polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) ranged from 17.2 to 297 pg/g wet weight in the same tissues, while the inclusion of TEQs from PCBs increased these values to 48.4 and 769 pg/g wet weight, respectively. While contaminant concentrations varied between species and tissues, the contaminant profile was relatively uniform. The profile of contaminants detected was unusual in that much of the TEQs was contributed by two pentachlorinated congeners (2,3,4,7,8-pentachlorinated dibenzo-p-dioxin), and the profiles of PCB congeners did not match known sources. When compared to other studies the concentrations detected in the Midway Atoll samples were near or above the thresholds known to cause adverse effects in other fish-eating bird species.

  6. Push-Pull Tests for Evaluating the Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons: Cost & Performance Report

    National Research Council Canada - National Science Library

    Semprini, Lew

    2006-01-01

    .... Tests were performed at McClellan Air Force Base (McAFB), California, using propane as the cometabolic substrate, and at Fort Lewis Logistics Center, Washington, using toluene as the cometabolic...

  7. BIOAUGMENTATION OF FE(0) FOR REMEDIATION OF CHLORINATED ALIPHATIC HYDROCARBONS. (R825549C044)

    Science.gov (United States)

    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...

  8. BIOAUGMENTATION OF FE(0) FOR REMEDIATION OF CHLORINATED ALIPHATIC HYDROCARBONS. (R825549C053)

    Science.gov (United States)

    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...

  9. Biodegradation of chlorinated unsaturated hydrocarbons in relation to biological waste-gas treatment

    OpenAIRE

    Hartmans, S.

    1993-01-01

    The original goal of the research described in this thesis was to develop a biological process for the removal of vinyl chloride from waste gases. The gaseous and carcinogenic vinyl chloride is used to produce the plastic polyvinyl chloride (PVC). During this production process waste gases containing vinyl chloride are generated. As a microorganism capable of growth on vinyl chloride as the sole carbon and energy source had been isolated it was envisaged that it might be possible to ...

  10. Biodegradation of chlorinated unsaturated hydrocarbons in relation to biological waste-gas treatment

    NARCIS (Netherlands)

    Hartmans, S.

    1993-01-01

    The original goal of the research described in this thesis was to develop a biological process for the removal of vinyl chloride from waste gases. The gaseous and carcinogenic vinyl chloride is used to produce the plastic polyvinyl chloride (PVC). During this production process waste gases

  11. Polycyclic Aromatic Hydrocarbons in Air and their Toxic Potency

    Indian Academy of Sciences (India)

    mental impact assessment, pollution biology, environ- mental chemistry and economics. Keywords ... However, such miniscule levels can have impacts on biological systems on long-term exposure. Some PARs readily ..... 299. 1986. [2] ToxicologicalProfile for Poly-. AromaticHydrocarbons (PA-. Hs) update, US Department.

  12. Isolation and Characterization of Hydrocarbon-utilizing Bacteria from ...

    African Journals Online (AJOL)

    ADOWIE PERE

    crude oil wastes, and leakages due to corrosion of tanks and pipelines as well as vandalization. The release of hydrocarbon pollutants into the environment whether accidentally or due to human error is the main cause of water and soil pollution. Fortunately, microorganisms are highly efficient and versatile in their ability to ...

  13. Removal of crude petroleum hydrocarbons by heterotrophic bacteria ...

    African Journals Online (AJOL)

    SERVER

    2007-07-04

    Jul 4, 2007 ... Lloyd GJ, Lau PCK (1997). Gluthion S – Transferase Encoding Gene as. Potential Probe for Environmental Bacterial Isolates Capable of. Degrading Polycyclic Aromatic Hydrocarbons. Appl. Environ. Microbiol. 63(8): 3286–3290. Murphy HF (1929). Some effects of crude petroleum on nitrate production.

  14. Uptake of crude petroleum hydrocarbons by mudflat bacteria ...

    African Journals Online (AJOL)

    In the Niger delta, due to the large-scale exploration and exploitation of crude petroleum, hydrocarbon spills frequently occur. The adverse impacts of these occurrences have frequently been causes for concerns in the area. However, in open estuarine environments, minor spills have short-term effects due to washout by ...

  15. Hydrocarbon-degrading Bacteria Isolation and Surfactant Influence ...

    African Journals Online (AJOL)

    DR OKARE

    2012-08-07

    Aug 7, 2012 ... 1Department of Epidemiology, Medical Statistics and Environmental Health, Faculty of Public Health, College of. Medicine, University ... hydrocarbon degrading bacteria and to establish the effect of surfactants on the growth of organisms. ... They are released into the soil environment as industrial chemicals.

  16. Degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria

    NARCIS (Netherlands)

    Weelink, S.A.B.

    2008-01-01

    Accidental spills, industrial discharges and gasoline leakage from underground storage tanks have resulted in serious pollution of the environment with monoaromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX). High concentrations of BTEX have been detected in

  17. carcinogenic potency of polycyclic aromatic hydrocarbons in soil

    African Journals Online (AJOL)

    Carcinogenic potency of polycyclic aromatic hydrocarbons (PAHs) in soils obtained from seven different sampling locations in Effurun metropolis and its environs of Niger Delta Area of Nigeria were evaluated. The 16 US EPA priority PAHs were determined with GC-MS. The concentrations of individual PAHs observed were ...

  18. Biodegradation of polycyclic aromatic hydrocarbons in crude oil ...

    African Journals Online (AJOL)

    Release of crude oil and its products into the environment has resulted in many problems that are of global concern. The objective of this study was to determine effect of Composted Market Waste (CMW) on the degradation of Polycyclic Aromatic Hydrocarbons (PAHs) in crude oil-contaminated soil. Pot experiment was ...

  19. Biodegradation of Polycyclic Aromatic Hydrocarbons in Crude oil ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Release of crude oil and its products into the environment has resulted in many problems that are of global concern. The objective of this study was to determine effect of Composted Market Waste (CMW) on the degradation of Polycyclic Aromatic Hydrocarbons (PAHs) in crude oil-contaminated soil.

  20. Effects of Refined Petroleum Hydrocarbon on Soil Physicochemical ...

    African Journals Online (AJOL)

    JASEM ISSN 1 119 - 8362. All rights reserved. J. Appl. Sci. Environ. Mgr. 2002. Vol. 6 (I) 39 a 44. Effects of Refined Petroleum Hydrocarbon on Soil Physicochemical and Bacteriological. Characteristics. *OBIRE, O; NWAUBETA, 0. Department 0/ Biological Sciences, Rivers State University 0F Science and Technology, RM.

  1. Effect of chlorination on the development of marine biofilms dominated by diatoms

    Digital Repository Service at National Institute of Oceanography (India)

    Patil, J.S.; Jagadeesan, V.

    “Biofouling Prevention Technologies for Coastal sensors/Sensor platform”, although further development in this direction is required (ACT report 2003). The antifouling efficiency of UVR in the prevention of marine biofouling has been reported (Patil et al... is minimised and that short pulses of chlorine may prove to be useful in preventing biofilm formation on the sensor heads of the oceanographic instruments, which are deployed in the marine environment for periods of weeks to months in order to capture...

  2. Effect of antecedent growth conditions on sensitivity of Escherichia coli to chlorine dioxide.

    OpenAIRE

    Berg, J D; Matin, A; Roberts, P V

    1982-01-01

    Bacterial resistance to inactivation by antibacterial agents that is induced by the growth environment was studied. Escherichia coli was grown in batch culture and in a chemostat, and the following parameters were varied: type of substrate, growth rate, temperature, and cell density during growth. Low doses (0.75 mg/liter) of chlorine dioxide were used to inactivate the cultures. The results demonstrated that populations grown under conditions that more closely approximated natural aquatic en...

  3. Stability and effectiveness of chlorine disinfectants in water distribution systems.

    Science.gov (United States)

    Olivieri, V P; Snead, M C; Krusé, C W; Kawata, K

    1986-11-01

    A test system for water distribution was used to evaluate the stability and effectiveness of three residual disinfectants--free chlorine, combined chlorine, and chlorine dioxide--when challenged with a sewage contaminant. The test distribution system consisted of the street main and internal plumbing for two barracks at Fort George G. Meade, MD. To the existing pipe network, 152 m (500 ft) of 13-mm (0.5 in.) copper pipe were added for sampling, and 60 m (200 ft) of 2.54-cm (1.0 in.) plastic pipe were added for circulation. The levels of residual disinfectants tested were 0.2 mg/L and 1.0 mg/L as available chlorine. In the absence of a disinfectant residual, microorganisms in the sewage contaminant were consistently recovered at high levels. The presence of any disinfectant residual reduced the microorganism level and frequency of occurrence at the consumer's tap. Free chlorine was the most effective residual disinfectant and may serve as a marker or flag in the distribution network. Free chlorine and chlorine dioxide were the least stable in the pipe network. The loss of disinfectant in the pipe network followed first-order kinetics. The half-life determined in static tests for free chlorine, chlorine dioxide, and combined chlorine was 140, 93, and 1680 min.

  4. Microbial Diversity and Bioremediation of a Hydrocarbon-Contaminated Aquifer (Vega Baja, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Arturo A. Massol-Deyá

    2006-09-01

    Full Text Available Hydrocarbon contamination of groundwater resources has become a major environmental and human health concern in many parts of the world. Our objectives were to employ both culture and culture-independent techniques to characterize the dynamics of microbial community structure within a fluidized bed reactor used to bioremediate a diesel-contaminated groundwater in a tropical environment. Under normal operating conditions, 97 to 99% of total hydrocarbons were removed with only 14 min hydraulic retention time. Over 25 different cultures were isolated from the treatment unit (96% which utilized diesel constituents as sole carbon source. Approximately 20% of the isolates were also capable of complete denitrification to nitrogen gas. Sequence analysis of 16S rDNA demonstrated ample diversity with most belonging to the ∝, β and γ subdivision of the Proteobacteria, Bacilli, and Actinobacteria groups. Moreover, the genetic constitution of the microbial community was examined at multiple time points with a Functional Gene Array (FGA containing over 12,000 probes for genes involved in organic degradation and major biogeochemical cycles. Total community DNA was extracted and amplified using an isothermal φ29 polymerase-based technique, labeled with Cy5 dye, and hybridized to the arrays in 50% formimide overnight at 50°C. Cluster analysis revealed comparable profiles over the course of treatment suggesting the early selection of a very stable microbial community. A total of 270 genes for organic contaminant degradation (including naphthalene, toluene [aerobic and anaerobic], octane, biphenyl, pyrene, xylene, phenanthrene, and benzene; and 333 genes involved in metabolic activities (nitrite and nitrous oxide reductases [nirS, nirK, and nosZ], dissimilatory sulfite reductases [dsrAB], potential metal reducing C-type cytochromes, and methane monooxygenase [pmoA] were repeatedly detected. Genes for degradation of MTBE

  5. UV/chlorine as an advanced oxidation process for the degradation of benzalkonium chloride: Synergistic effect, transformation products and toxicity evaluation.

    Science.gov (United States)

    Huang, Nan; Wang, Ting; Wang, Wen-Long; Wu, Qian-Yuan; Li, Ang; Hu, Hong-Ying

    2017-05-01

    Benzalkonium chlorides (BACs), as typical cationic surfactants and biocides widely applied in household and industrial products, have been frequently detected as micropollutants in many aquatic environments. In this study, the combination of UV irradiation and chlorine (UV/chlorine), a newly interested advanced oxidation process, was used to degrade dodecylbenzyldimethylammonium chloride (DDBAC). UV/chlorine showed synergistic effects on DDBAC degradation comparing to UV irradiation or chlorination alone. Radical quenching experiments indicated that degradation of DDBAC by UV/chlorine involved both UV photolysis and radical species oxidation, which accounted for 48.4% and 51.6%, respectively. Chlorine dosage and pH are essential parameters affecting the treatment efficiency of UV/chlorine. The pseudo first order rate constant (kobs, DDBAC) increased from 0.046 min-1 to 0.123 min-1 in response to chlorine dosage at 0-150 mg/L, and the degradation percentage of DDBAC within 12 min decreased from 81.4% to 56.6% at pH 3.6-9.5. Five main intermediates were identified and semi-quantified using HPLC-MS/MS and a possible degradation pathway was proposed. The degradation mechanisms of DDBAC by UV/chlorine included cleavage of the benzyl-nitrogen bond and hydrogen abstraction of the alkyl chain. Trichloromethane (TCM), chloral hydrate (CH), trichloropropanone (TCP), dichloropropanone (DCP) and dichloroacetonitrile (DCAN) were detected using GC-ECD. The formation of chlorinated products increased rapidly initially, then decreased (TCM, TCP, DCP and DCAN) or remained stable (CH) with extended treatment. The actual formation of TCM peaked at 30 min (50.3 μg/L), while other chlorinated products did not exceed 10 μg/L throughout the process. Based on the luminescent bacterial assay, DDBAC solution underwent almost complete detoxification subjected to UV/chlorine treatment for 120 min, which is more effective than UV irradiation or chlorination alone. Copyright © 2017

  6. A comparison of iodinated trihalomethane formation from chlorine, chlorine dioxide and potassium permanganate oxidation processes.

    Science.gov (United States)

    Zhang, Tian-Yang; Xu, Bin; Hu, Chen-Yan; Lin, Yi-Li; Lin, Lin; Ye, Tao; Tian, Fu-Xiang

    2015-01-01

    This study compared the formation of iodinated trihalomethanes (I-THMs) from iodide-containing raw waters oxidized by chlorine, chlorine dioxide (ClO₂) and potassium permanganate (KMnO₄) at different oxidant concentrations, reaction times, pHs, initial iodide concentrations and bromide to iodide mass ratios. Among the six investigated I-THMs, iodoform was the major species formed during the oxidation using chlorine, ClO₂ and KMnO₄. When oxidant concentration increased from 0.1 to 3.0 mg/L, the formation of I-THMs increased and then decreased for chlorine and ClO₂, but kept increasing for KMnO₄. As the reaction time went by, I-THM concentration increased to a plateau within 10 h (ClO₂ within only 1 h, especially) for all the three oxidants. I-THM formation gradually increased from pH 3.0 to 9.0 and remained stable at pH values higher than 7.5 for chlorine; however, for ClO₂ and KMnO₄ the highest I-THM formation showed at pH 7.0 and 7.5, respectively. As initial iodide concentration increased from 20 to 800 μg/L, the total amount and species of I-THMs increased for the three oxidants. Iodide contributed to I-THM formation much more significantly than bromide.

  7. Chlorine-Free Red-Burning Pyrotechnics.

    Science.gov (United States)

    Sabatini, Jesse J; Koch, Ernst-Christian; Poret, Jay C; Moretti, Jared D; Harbol, Seth M

    2015-09-07

    The development of a red, chlorine-free pyrotechnic illuminant of high luminosity and spectral purity was investigated. Red-light emission based solely on transient SrOH(g) has been achieved by using either 5-amino-1H-tetrazole or hexamine to deoxidize the combustion flame of a Mg/Sr(NO3 )2 /Epon-binder composition and reduce the amount of both condensed and gaseous SrO, which emits undesirable orange-red light. The new formulations were found to possess high thermal onset temperatures. Avoiding chlorine in these formulations eliminates the risk of the formation of PCBs, PCDDs, and PCDFs. This finding, hence, will have a great impact on both military pyrotechnics and commercial firework sectors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Revisiting the thermochemistry of chlorine fluorides.

    Science.gov (United States)

    Sánchez, Hernán R

    2017-08-15

    In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClFn, n = 1-7; Cl2 F and Cl3 F2 ) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. To complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Revisiting the thermochemistry of chlorine fluorides

    CERN Document Server

    Sánchez, H R

    2016-01-01

    In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClF$_n$, n=1--7; Cl$_2$F and Cl$_3$F$_2$) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. In order to complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods.

  10. Silicon Carbide Etching Using Chlorine Trifluoride Gas

    Science.gov (United States)

    Habuka, Hitoshi; Oda, Satoko; Fukai, Yasushi; Fukae, Katsuya; Takeuchi, Takashi; Aihara, Masahiko

    2005-03-01

    The etch rate, chemical reactions and etched surface of β-silicon carbide are studied in detail using chlorine trifluoride gas. The etch rate is greater than 10 μm min-1 at 723 K with a flow rate of 0.1 \\ell min-1 at atmospheric pressure in a horizontal reactor. The maximum etch rate at a substrate temperature of 773 K is 40 μm min-1 with a flow rate of 0.25 \\ell min-1. The step-like pattern that initially exists on the β-silicon carbide surface tends to be smoothed; the root-mean-square surface roughness decreases from its initial value of 5 μm to 1 μm within 15 min; this minimum value is maintained for more than 15 min. Therefore, chlorine trifluoride gas is considered to have a large etch rate for β-silicon carbide associated with making a rough surface smooth.

  11. Identification of intermediates leading to chloroform and C-4 diacids in the chlorination of humic acid

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Leer, E.W.B. de; Erkelens, Corrie; Galan, L.

    1985-01-01

    The chlorination of terrestrial humic acid was studied at pH 7. 2 with varying chlorine to carbon ratios. The principal products are chloroform, di- and trichloroacetic acid, and chlorinated C-4 diacids. At a high chlorine dose many new chlorination products were detected, among them

  12. DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS ...

    African Journals Online (AJOL)

    AMOS

    Scomber scombrus), suya beef and plantain (Musa paradiasca) sold and consumed in Amassoma town were screened for the presence of 15 polycyclic aromatic hydrocarbons (PAHs). Concentration of chromium, lead and cadmium were also ...

  13. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  14. Hydrocarbon Leak Detection Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT is proposing the development of a sensor to detect the presence of hydrocarbons in turbopump Inter-Propellant Seals (IPS). The purpose of the IPS is to prevent...

  15. Chlorine requirement for Japanese laying quails

    Directory of Open Access Journals (Sweden)

    Fernando Guilherme Perazzo Costa

    2012-10-01

    Full Text Available The objective of this study was to determine the chlorine nutritional requirement of Japanese Quails during the laying phase, based on performance and egg quality parameters. A total of 240 Japanese quails were distributed according to a randomized block design, with five treatments and six replicates, with 8 birds each. The experiment lasted 84 days, divided in four cycles of 21 days each. Treatments consisted of a basal diet formulated to meet the nutritional requirements, except for chlorine, and four supplementation levels with ammonium chloride, generating the levels 0.8; 1.6; 2.4; 3.2 and 4.0 g/kg. The parameters evaluated were: feed intake (g/bird/day, egg production (egg/bird/day, egg weight (g, egg mass (g, egg mass conversion (g/g, conversion per dozen eggs (kg/dz, weight of yolk (g/100 g of egg, albumen (g/100g of egg and shell (g/100 g of egg, specific gravity (g/cm³ and shell thickness (mm. As a result of this study, feed intake, egg weight, weights of albumen, yolk, shell and specific gravity were not affected by treatments. There was a quadratic behavior for egg production, egg mass, egg mass conversion, conversion per dozen eggs and shell thickness according to the chlorine levels in the diets, with the requirements for those parameters established at 1.54; 1.37; 1.39 and 2.78 g/kg, respectively. The recommendation is 1.39 g/kg of chlorine and 244.22 mEq/kg of electrolyte balance in diets for Japanese quails.

  16. Effect of Sulfur and Hydrocarbon Fuels on Titanate/Ceria SOFC Anodes

    Energy Technology Data Exchange (ETDEWEB)

    Marina, O.A.; Pedersen, L.R.; Stevenson, J.W.

    2005-01-27

    The purpose of the project is to develop low-cost, high-performance anodes that offer low polarization resistance as well as improved tolerance for nonidealities in anode environment such as redox cycles, sulfur and other poisons, and hydrocarbons.

  17. The Greening of Pesticide–Environment Interactions: Some Personal Observations

    Science.gov (United States)

    2012-01-01

    of many chlorinated hydrocarbons, the development of new biochemical targets, increased reliance on genetically modified crops that reduce the amount and variety of pesticides applied, emphasis on biodegradability and environmental protection, and integrated pest- and pesticide-management systems. PMID:22472325

  18. Alumino-silicate catalyst and use for aromatization of hydrocarbons comprising 5 to 12 carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Alario, F.; Deves, J.M.

    1993-05-21

    The invention describes a composite catalyst which contains: a MFI structure zeolite in the form hydrogen, containing in its structure Silicon, Aluminium and / or Gallium at least; a matrix; platinum metals at least and additive metal chosen among Stain, Germanium, Indium, Copper, Iron, Molybdenum, Gallium, Thallium, Gold, Silver, Ruthenium, Chrome, Tungsten and Lead at least; an halogen chosen among Fluorine, Chlorine, Bromine and Iodine at least; possibly, doping element chosen among Gallium and Zinc and possibly alkaline or alkaline-earth metal in the matrix preferentially. The invention describes also the use of this catalyst for aromatization reactions of hydrocarbons containing 5 to 12 carbon atoms per molecule.

  19. MFI structure catalyst and utilization for aromatization hydrocarbons comprising 5 to 12 carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Alario, F.; Deves, J.M.

    1993-05-21

    The invention describes a composite catalyst which contains: a MFI structure zeolite containing, at least, an element chosen among alkaline or alkaline-earth metals, with a structure made of Silicon, Aluminium and / or Gallium; a matrix; platinum metals and additive metal chosen among Stain, Germanium, Indium, Copper, Iron, Molybdenum, Gallium, Thallium, Gold, Silver, Ruthenium, Chrome, Tungsten and Lead at least; an halogen chosen among Fluorine, Chlorine, Bromine and Iodine at least; Gallium and Zinc possibly; alkaline or alkaline-earth metal in the matrix preferentially. The invention describes also the use of this catalyst for aromatization reactions of hydrocarbons containing 5 to 12 carbon atoms per molecule.

  20. Approaches for the analysis of chlorinated lipids.

    Science.gov (United States)

    Wang, Wen-Yi; Albert, Carolyn J; Ford, David A

    2013-12-15

    Leukocytes are key cellular mediators of human diseases through their role in inflammation. Identifying unique molecules produced by leukocytes may provide new biomarkers and mechanistic insights into the role of leukocytes in disease. Chlorinated lipids are generated as a result of myeloperoxidase-containing leukocyte-derived hypochlorous acid targeting the vinyl ether bond of plasmalogens. The initial product of this reaction is α-chlorofatty aldehyde. α-Chlorofatty aldehyde is both oxidized to α-chlorofatty acid and reduced to α-chlorofatty alcohol by cellular metabolism. This review focuses on the separation techniques and quantitative analysis for these chlorinated lipids. For α-chlorofatty acid, the negative charge of carboxylic acids is exploited to detect the chlorinated lipid species of these acids by electrospray ionization mass spectrometry in the negative ion mode. In contrast, α-chlorofatty aldehyde and α-chlorofatty alcohol are converted to pentafluorobenzyl oxime and pentafluorobenzoyl ester derivatives, which are detected by negative ion chemical ionization mass spectrometry. These two detection methods coupled with the use of stable isotope internal standards and either liquid chromatography or gas chromatography provide highly sensitive analytical approaches to measure these novel lipids. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  2. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  3. Uranium oxide catalysts: environmental applications for treatment of chlorinated organic waste from nuclear industry.

    Science.gov (United States)

    Lazareva, Svetlana; Ismagilov, Zinfer; Kuznetsov, Vadim; Shikina, Nadezhda; Kerzhentsev, Mikhail

    2018-02-05

    Huge amounts of nuclear waste, including depleted uranium, significantly contribute to the adverse environmental situation throughout the world. An approach to the effective use of uranium oxides in catalysts for the deep oxidation of chlorine-containing hydrocarbons is suggested. Investigation of the catalytic activity of the synthesized supported uranium oxide catalysts doped with Cr, Mn and Co transition metals in the chlorobenzene oxidation showed that these catalysts are comparable with conventional commercial ones. Physicochemical properties of the catalysts were studied by X-ray diffraction, temperature-programmed reduction with hydrogen (H 2 -TPR), and Fourier transform infrared spectroscopy. The higher activity of Mn- and Co-containing uranium oxide catalysts in the H 2 -TPR and oxidation of chlorobenzene in comparison with non-uranium catalysts may be related to the formation of a new disperse phase represented by uranates. The study of chlorobenzene adsorption revealed that the surface oxygen is involved in the catalytic process.

  4. Separation of aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Grishchenko, N.F.; Yablochkina, M.N.; Shapiro, L.P.; Rogozkin, V.A.

    1979-01-01

    An optimal system of extraction has been developed making it possible to produce benzene, toluene and xylenes economically and with high efficiency.The raw material used for catalytic reforming consists of narrow-boiling-range gasoline fractiions at 62 to 85, 62 to 105 and 105 to 140/sup 0/C. Processing of the first fraction makes it possible to produce benzene; the second, benzene and toluene; and the third, toluene and xylenes. The addition of reforming extraction units has made it possible to produce aromatic hydrocarbons suitable for any specialized application. At the current time the output of benzene with extraction plants is about 60 percent of the total output, of toluene more than 80 percent and of xylene more than 50 percent. The key technological indicators are given for the processes of extraction with hydrous polyglycols. For new higher-capacity plants, in addition to extraction with tetraethylene glycol, the 'Ekstars' process has been developed for extraction with a hybrid solvent based on propylene carbonate. For eliminating the presence of unsaturated compounds, a process has been developed for the selective hydrogenation of reforming catalysis products. The process is carried out in an additional reactor included in the catalytic reforming system, at 160 to 250/sup 0/C with an aluminoplatinic catalyst in a combined steam and gas mixture flow at a pressure of 1.5 to 3.5 MPa. (JMT)

  5. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  6. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  7. Transformation of acesulfame in chlorination: Kinetics study, identification of byproducts, and toxicity assessment.

    Science.gov (United States)

    Li, Adela Jing; Wu, Pengran; Law, Japhet Cheuk-Fung; Chow, Chi-Hang; Postigo, Cristina; Guo, Ying; Leung, Kelvin Sze-Yin

    2017-06-15

    Acesulfame (ACE) is one of the most commonly used artificial sweeteners. Because it is not metabolized in the human gut, it reaches the aquatic environment unchanged. In the present study, the reactivity of ACE in free chlorine-containing water was investigated for the first time. The degradation of ACE was found to follow pseudo-first-order kinetics. The first-order rate increased with decreasing pH from 9.4 to 4.8 with estimated half-lives from 693 min to 2 min. Structural elucidation of the detected transformation products (TPs) was performed by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Integration of MS/MS fragments, isotopic pattern and exact mass allowed the characterization of up to 5 different TPs in the ultrapure water extracts analyzed, including two proposed new chlorinated compounds reported for the first time. Unexpectedly, several known and regulated disinfection by-products (DBPs) were present in the ACE chlorinated solution. In addition, two of the six DBPs are proposed as N-DBPs. Time-course profiles of ACE and the identified by-products in tap water and wastewater samples were followed in order to simulate the actual disinfection process. Tap water did not significantly affect degradation, but wastewater did; it reacted with the ACE to produce several brominated-DBPs. A preliminary assessment of chlorinated mixtures by luminescence inhibition of Vibrio fischeri showed that these by-products were up to 1.8-fold more toxic than the parent compound. The generation of these DBPs, both regulated and not, representing enhanced toxicity, make chlorine disinfection a controversial treatment for ACE. Further efforts are urgently needed to both assess the consequences of current water treatment processes on ACE and to develop new processes that will safely treat ACE. Human health and the health of our aquatic ecosystems are at stake. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Transformation of avobenzone in conditions of aquatic chlorination and UV-irradiation.

    Science.gov (United States)

    Trebše, Polonca; Polyakova, Olga V; Baranova, Maria; Kralj, Mojca Bavcon; Dolenc, Darko; Sarakha, Mohamed; Kutin, Alexander; Lebedev, Albert T

    2016-09-15

    Emerging contaminants represent a wide group of the most different compounds. They appear in the environment at trace levels due to human activity. Most of these compounds are not yet regulated. Sunscreen UV-filters play an important role among these emerging contaminants. In the present research the reactions of 4-tert-butyl-4'-methoxydibenzoylmethane (avobenzone), the most common UV filter in the formulation of sunscreens, were studied under the combined influence of active chlorine and UV-irradiation. Twenty five compounds were identified by GC/MS as transformation products of avobenzone in reactions of aquatic UV-irradiation and chlorination with sodium hypochlorite. A complete scheme of transformation of avobenzone covering all the semivolatile products is proposed. The identification of the two primary chlorination products (2-chloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione and 2,2-dichloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione) was confirmed by their synthesis and GC/MS and NMR analysis. Although the toxicities of the majority of these products remain unknown substituted chlorinated phenols and acetophenones are known to be rather toxic. Combined action of active chlorine and UV-irradiation results in the formation of some products (chloroanhydrides, chlorophenols) not forming in conditions of separate application of these disinfection methods. Therefore caring for people «well-being» it is of great importance to apply the most appropriate disinfection method. Since the primary transformation products partially resist powerful UV-C irradiation they may be treated as stable and persistent pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Attacks of Asthma due to Chlorinized Water: Case Report

    Directory of Open Access Journals (Sweden)

    Murat Eyup Berdan

    2008-02-01

    Full Text Available The presence of a high prevalence of bronchial hyperresponsiveness and asthma-like symptoms in swimmers has been reported. But, attacks of asthma which is related to chlorinized water is rare. Chlorine, a strong oxidizing agent, is an important toxic gas that the swimmer can breath during swimming and a worker can exposed to chlorine while he or she was using water with chlorine at home. We describe a persistent increase in nonspecific bronchial hyperresponsiveness following chronic exposure to strong respiratory irritant with chlorinized water in two subjects with no past history of asthma or atopy. We conclude that airway hyperresponsiveness can develop or increase after chronic inhalation of high concentrations of irritants such as chlorinized water an indoor irritant factor and that these changes may be prolonged. [TAF Prev Med Bull 2008; 7(1.000: 87-90

  10. Kinetic modelling of chlorination of nitrided ilmenite using MATLAB

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Sivakumar, E-mail: srsivakumar@usm.my; Kwok, Teong Chen, E-mail: ctck@live.com; Hamid, Sheikh Abdul Rezan Sheikh Abdul, E-mail: rezanshk@gmail.com [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300, Nibong Tebal, Penang (Malaysia)

    2016-07-19

    In the present study, chlorination of nitride ilmenite using 2{sup k} factorial design was investigated. The reduction experiments were carried out in a temperature range of 400°C to 500°C, chlorination duration from 1 hour to 3 hours and using different type of carbon reactant. Phases of raw materials and reduced samples were analyzed by X-ray diffraction (XRD). Ilmenite was reduced to TiO{sub x}C{sub y}N{sub z} through carbothermal and nitridation for further chlorination into titanium tetrachloride. The Design of Experiment analysis suggested that the types of carbon reactant contribute most influence to the extent of chlorination of nitride ilmenite. The extent of chlorination was highest at 500°C with 3 hours chlorination time and carbon nanotube as carbon reactant.

  11. Deliberate exposure of humans to chlorine-the aftermath of Ebola in West Africa

    Directory of Open Access Journals (Sweden)

    Shaheen Mehtar

    2016-11-01

    Full Text Available Abstract Background During the recent Ebola outbreak, spraying of the environment and humans, including healthcare workers, with chlorine was wide spread in affected African countries; adverse clinical effects are reported here. Methods A cross sectional survey by interview of 1550 volunteers consisting of 500 healthcare workers (HCW, 550 Ebola survivors (EVD and 500 quarantined asymptomatic Ebola contacts (NEVD was conducted. Demographics, frequency of exposure to chlorine, clinical condition after chlorine exposure particularly eye, respiratory and skin conditions were noted. The length of time HCWs worked in Ebola Treatment Units (ETU, and use of personal protective equipment was recorded. Verbal consent was obtained from all participants and all responses remained anonymous. Permission and assistance from the guardian or parent was sought for those below 18 years of age. Results 493/500 HCW, 550/550 EVD and 477/500 NEVD were sprayed at least once with 0 · 5 % chlorine. Following even a single exposure, an increase in the number of eye (all three groups and respiratory symptoms (in HCW & EVD was reported (p < 0 · 001; after multiple exposure, respiratory and skin symptoms increased. In HCW, multiple vs single exposure was associated with an increase in respiratory (OR = 32 (95 % CI 22 –49 p < 0.001, eyes (OR = 30 (95 % CI 21 –43 p < 0.001 and skin conditions (OR = 22 (95 % CI 15–32 p < 0.001. The available personal protective equipment neither reduced nor prevented the adverse effects of chlorine. Conclusion Reported exposure to chlorine has usually been accidental. Despite the lack of evidence as a recognised outbreak control measure, deliberate exposure of humans to chlorine spray was wide spread in Africa during the Ebola epidemic resulting in serious detrimental health effects on humans. We strongly recommend that this practice be banned and that alternative safer methods be used.

  12. The removal of phenols from oily wastewater by chlorine dioxide

    OpenAIRE

    Hsu, Chung-Jung

    1988-01-01

    Treatability studies were performed on oily wastewaters produced by petroleum and canning industries. Chlorine dioxide was used for the removal of phenolic compounds from these oily wastewaters. Most of phenolic compounds can be destroyed by chlorine dioxide within 15 minutes if CI02-to-phenol ratios of higher than 5.0 are provided. Factors such as pH, temperature, and COD have little effect on phenol removal. The effectiveness of chlorine dioxide treatment depends critic...

  13. Thermal degradation of sucralose: a combination of analytical methods to determine stability and chlorinated byproducts

    Science.gov (United States)

    de Oliveira, Diogo N.; de Menezes, Maico; Catharino, Rodrigo R.

    2015-04-01

    In the late years, much attention has been brought to the scientific community regarding the safety of sucralose and its industrial applications. Although it is the most used artificial sweetener in foods and pharmaceuticals, many questions still arise on its potential to form chlorinated byproducts in high temperatures, as demonstrated by several recent studies. In the present contribution, we use a combination of differential scanning calorimetry and thermogravimetric analysis coupled with infrared spectroscopy (DSC/TGA/IR), Hot-stage microscopy (HSM) and high-resolution mass spectrometry (HRMS) on samples submitted to water bath at mild temperatures to evaluate a broad spectrum of hazardous compounds formed in the degradation of this product. TGA/IR has revealed that there is effective decomposition in form of CO2 along with the formation of hydrogen chloride and other minor compounds. HSM results have provided accurate information, where the melting of the crystals was observed, followed by decomposition. Chlorinated derivatives, including polychlorinated aromatic hydrocarbons (PCAHs) were also confirmed by HRMS. These findings not only corroborate the suspected instability of sucralose to high temperatures, but also indicate that even exposed to mild conditions the formation of hazardous polychlorinated compounds is observed.

  14. Bioremediation of soils contaminated with petroleum hydrocarbons using bioslurry reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Banerji, S.K.; Zappi, M.E.; Teeter, C.L.; Gunnison, D.; Cullinane, M.J.

    1995-10-01

    The Department of Defense has over 12,000 sites contaminated from military activities. This report presents data from two bench-scale and two pilot-scale studies that evaluated the suitability of the bioslurry process to bioremediate soils contaminated by petroleum hydrocarbons. Soils from two contaminated sites were studied. The first soil contained polycyclic aromatic hydrocarbons (PAHs), BTEX (benzene, toluene, ethylbenzene, and xylene) compounds, ketones, and chlorinated ethanes; the second soil contained gasoline and associated compounds. Conceptual designs and costs of bioslurry processes for field applications are also presented. Bench-scale studies were performed in 5-L batch reactors, equipped with aeration and mixing equipment. Various nutrient amendments, surfactants, and selected microbial consortia were evaluated during the bench-scale studies. Several reactors were also operated using only native microbes.

  15. Exposure to polycyclic aromatic hydrocarbons (PAHs) and bladder cancer: evaluation from a gene-environment perspective in a hospital-based case-control study in the Canary Islands (Spain)

    Science.gov (United States)

    Boada, Luis D; Henríquez-Hernández, Luis A; Navarro, Patricio; Zumbado, Manuel; Almeida-González, Maira; Camacho, María; Álvarez-León, Eva E; Valencia-Santana, Jorge A; Luzardo, Octavio P

    2015-01-01

    Background: Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to bladder cancer. Objective: To evaluate the role of PAHs in bladder cancer, PAHs serum levels were measured in patients and controls from a case-control study. Methods: A total of 140 bladder cancer patients and 206 healthy controls were included in the study. Sixteen PAHs were analyzed from the serum of subjects by gas chromatography–mass spectrometry. Results: Serum PAHs did not appear to be related to bladder cancer risk, although the profile of contamination by PAHs was different between patients and controls: pyrene (Pyr) was solely detected in controls and chrysene (Chry) was exclusively detected in the cases. Phenanthrene (Phe) serum levels were inversely associated with bladder cancer (OR = 0·79, 95%CI = 0·64–0·99, P = 0·030), although this effect disappeared when the allelic distribution of glutathione-S-transferase polymorphisms of the population was introduced into the model (multinomial logistic regression test, P = 0·933). Smoking (OR = 3·62, 95%CI = 1·93–6·79, PPAH mixtures may play a relevant role in bladder cancer, although such effect seems to be highly modulated by polymorphisms in genes encoding xenobiotic-metabolizing enzymes. PMID:25291984

  16. UASB reactor effluent disinfection by ozone and chlorine.

    Science.gov (United States)

    Ribeiro da Silva, Gustavo Henrique; Bruning, Harry; Gerrity, Daniel; Daniel, Luiz Antonio

    2015-01-01

    This research studied the sequential ozone and chlorine process with respect to, the inactivation of indicator bacteria and the formation of ozone disinfection byproducts in sanitary wastewater effluent. The applied ozone doses were 5, 8 and 10 mg.O3.L(-1), followed by chlorine doses of 10, 20 and 30 mg.L(-1), respectively. After the sequential ozone/chlorine process, the mean reduction in chemical oxygen demand ranged from 9 to 37%. Total coliform inactivation ranged from 1.59 to 3.73 log10, and E. coli was always chlorine dose (P ≤ 0.05).

  17. Formation of organic chloramines during water disinfection: chlorination versus chloramination.

    Science.gov (United States)

    Lee, Wontae; Westerhoff, Paul

    2009-05-01

    Many of the available studies on formation of organic chloramines during chlorination or chloramination have involved model organic nitrogen compounds (e.g., amino acids), but not naturally occurring organic nitrogen in water. This study assessed organic chloramine formation during chlorination and chloramination of 16 natural organic matter (NOM) solutions and 16 surface waters which contained dissolved organic nitrogen (DON). Chlorination rapidly formed organic chloramines within 10 min, whereas chloramination formed organic chloramination much more slowly, reaching the maximum concentration between 2 and 120 h after the addition of monochloramine into the solutions containing DON. The average organic chloramine formation upon addition of free chlorine and monochloramine into the NOM solutions were 0.78 mg-Cl(2)/mg-DON at 10 min and 0.16 mg-Cl(2)/mg-DON at 24h, respectively. Organic chloramine formation upon chlorination and chloramination increased as the dissolved organic carbon/dissolved organic nitrogen (DOC/DON) ratio decreased (i.e., DON contents increased). Chlorination of molecular weight (10,000 Da) fractionated water showed that molecular weight of DON would not impact the amount of organic chloramines produced. Comparison of three different disinfection schemes at water treatment plants (free chlorine, preformed monochloramine, and chlorine/ammonia additions) indicated organic chloramine formation could lead to a possible overestimation of disinfection capacity in many chloraminated water systems that add chlorine followed by an ammonia addition to form monochloramine.

  18. Hydrocarbon pollutants shape bacterial community assembly of harbor sediments.

    Science.gov (United States)

    Barbato, Marta; Mapelli, Francesca; Magagnini, Mirko; Chouaia, Bessem; Armeni, Monica; Marasco, Ramona; Crotti, Elena; Daffonchio, Daniele; Borin, Sara

    2016-03-15

    Petroleum pollution results in co-contamination by different classes of molecules, entailing the occurrence of marine sediments difficult to remediate, as in the case of the Ancona harbor (Mediterranean Sea, Italy). Autochthonous bioaugmentation (ABA), by exploiting the indigenous microbes of the environment to be treated, could represent a successful bioremediation strategy. In this perspective we aimed to i) identify the main drivers of the bacterial communities' richness in the sediments, ii) establish enrichment cultures with different hydrocarbon pollutants evaluating their effects on the bacterial communities' composition, and iii) obtain a collection of hydrocarbon degrading bacteria potentially exploitable in ABA. The correlation between the selection of different specialized bacterial populations and the type of pollutants was demonstrated by culture-independent analyses, and by establishing a collection of bacteria with different hydrocarbon degradation traits. Our observations indicate that pollution dictates the diversity of sediment bacterial communities and shapes the ABA potential in harbor sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Hydrocarbon pollutants shape bacterial community assembly of harbor sediments

    KAUST Repository

    Barbato, Marta

    2016-02-02

    Petroleum pollution results in co-contamination by different classes of molecules, entailing the occurrence of marine sediments difficult to remediate, as in the case of the Ancona harbor (Mediterranean Sea, Italy). Autochthonous bioaugmentation (ABA), by exploiting the indigenous microbes of the environment to be treated, could represent a successful bioremediation strategy. In this perspective we aimed to i) identify the main drivers of the bacterial communities\\' richness in the sediments, ii) establish enrichment cultures with different hydrocarbon pollutants evaluating their effects on the bacterial communities\\' composition, and iii) obtain a collection of hydrocarbon degrading bacteria potentially exploitable in ABA. The correlation between the selection of different specialized bacterial populations and the type of pollutants was demonstrated by culture-independent analyses, and by establishing a collection of bacteria with different hydrocarbon degradation traits. Our observations indicate that pollution dictates the diversity of sediment bacterial communities and shapes the ABA potential in harbor sediments.

  20. Chlorination of parabens: reaction kinetics and transformation product identification.

    Science.gov (United States)

    Mao, Qianhui; Ji, Feng; Wang, Wei; Wang, Qiquan; Hu, Zhenhu; Yuan, Shoujun

    2016-11-01

    The reactivity and fate of parabens during chlorination were investigated in this work. Chlorination kinetics of methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) were studied in the pH range of 4.0 to 11.0 at 25 ± 1 °C. Apparent rate constants (k app) of 9.65 × 10-3 M-0.614·s-1, 1.77 × 10-2 M-1.019·s-1, 2.98 × 10-2 M-0.851·s-1, and 1.76 × 10-2 M-0.860·s-1 for MeP, EtP, PrP, and BuP, respectively, were obtained at pH 7.0. The rate constants depended on the solution pH, temperature, and NH4+ concentration. The maximum k app was obtained at pH 8.0, and the minimum value was obtained at pH 11.0. The reaction rate constants increased with increasing temperature. When NH4+ was added to the solution, the reaction of parabens was inhibited due to the rapid formation of chloramines. Two main transformation products, 3-chloro-parabens and 3,5-dichloro-parabens, were identified by GC-MS and LCMS-IT-TOF, and a reaction pathway was proposed. Dichlorinated parabens accumulated in solution, which is a threat to human health and the aqueous environment.

  1. Chlorination by-product concentration levels in seawater and fish of an industrialised bay (Gulf of Fos, France) exposed to multiple chlorinated effluents.

    Science.gov (United States)

    Boudjellaba, D; Dron, J; Revenko, G; Démelas, C; Boudenne, J-L

    2016-01-15

    Chlorination is one of the most widely used techniques for biofouling control in large industrial units, leading to the formation of halogenated chlorination by-products (CBPs). This study was carried out to evaluate the distribution and the dispersion of these compounds within an industrialised bay hosting multiple chlorination discharges issued from various industrial processes. The water column was sampled at the surface and at 7 m depth (or bottom) in 24 stations for the analysis of CBPs, and muscle samples from 15 conger eel (Conger conger) were also investigated. Temperature and salinity profiles supported the identification of the chlorination releases, with potentially complex patterns. Chemical analyses showed that bromoform was the most abundant CBP, ranging from 0.5 to 2.2 μg L(-1) away from outlets (up to 10 km distance), and up to 18.6 μg L(-1) in a liquefied natural gas (LNG) regasification plume. However, CBP distributions were not homogeneous, halophenols being prominent in a power station outlet and dibromoacetonitrile in more remote stations. A seasonal effect was identified as fewer stations revealed CBPs in summer, probably due to the air and water temperatures increases favouring volatilisation and reactivity. A simple risk assessment of the 11 identified CBPs showed that 7 compounds concentrations were above the potential risk levels to the local marine environment. Finally, conger eel muscles presented relatively high levels of 2,4,6-tribromophenol, traducing a generalised impregnation of the Gulf of Fos to CBPs and a global bioconcentration factor of 25 was determined for this compound. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. CHLORINE DECAY AND BIOFILM STUDIES IN A PILOT SCALE DRINKING WATER DISTRIBUTION DEAD END PIPE SYSTEM

    Science.gov (United States)

    Chlorine decay experiments using a pilot-scale water distribution dead end pipe system were conducted to define relationships between chlorine decay and environmental factors. These included flow rate, biomass concentration and biofilm density, and initial chlorine concentrations...

  3. DBP formation from degradation of DEET and ibuprofen by UV/chlorine process and subsequent post-chlorination.

    Science.gov (United States)

    Aghdam, Ehsan; Xiang, Yingying; Sun, Jianliang; Shang, Chii; Yang, Xin; Fang, Jingyun

    2017-08-01

    The formation of disinfection by-products (DBPs) from the degradation of N,N-diethyl-3-methyl benzoyl amide (DEET) and ibuprofen (IBP) by the ultraviolet irradiation (UV)/chlorine process and subsequent post-chlorination was investigated and compared with the UV/H2O2 process. The pseudo first-order rate constants of the degradation of DEET and IBP by the UV/chlorine process were 2 and 3.1 times higher than those by the UV/H2O2 process, respectively, under the tested conditions. This was due to the significant contributions of both reactive chlorine species (RCS) and hydroxyl radicals (HO) in the UV/chlorine process. Trichloromethane, 1,1,1-trichloro-2-propanone and dichloroacetic acid were the major known DBPs formed after 90% of both DEET and IBP that were degraded by the UV/chlorine process. Their yields increased by over 50% after subsequent 1-day post-chlorination. The detected DBPs after the degradation of DEET and IBP comprised 13.5% and 19.8% of total organic chlorine (TOCl), respectively, and the proportions increased to 19.8% and 33.9% after subsequent chlorination, respectively. In comparison to the UV/H2O2 process accompanied with post-chlorination, the formation of DBPs and TOCl in the UV/chlorine process together with post-chlorination was 5%-63% higher, likely due to the generation of more DBP precursors from the attack of RCS, in addition to HO. Copyright © 2017. Published by Elsevier B.V.

  4. High atmosphere-ocean exchange of semivolatile aromatic hydrocarbons

    Science.gov (United States)

    González-Gaya, Belén; Fernández-Pinos, María-Carmen; Morales, Laura; Méjanelle, Laurence; Abad, Esteban; Piña, Benjamin; Duarte, Carlos M.; Jiménez, Begoña; Dachs, Jordi

    2016-06-01

    Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 102-103 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr-1, around 15% of the oceanic CO2 uptake.

  5. Determining the Metabolic Footprints of Hydrocarbon Degradation Using Multivariate Analysis

    Science.gov (United States)

    Smith, Renee. J.; Jeffries, Thomas C.; Adetutu, Eric M.; Fairweather, Peter G.; Mitchell, James G.

    2013-01-01

    The functional dynamics of microbial communities are largely responsible for the clean-up of hydrocarbons in the environment. However, knowledge of the distinguishing functional genes, known as the metabolic footprint, present in hydrocarbon-impacted sites is still scarcely understood. Here, we conducted several multivariate analyses to characterise the metabolic footprints present in a variety of hydrocarbon-impacted and non-impacted sediments. Non-metric multi-dimensional scaling (NMDS) and canonical analysis of principal coordinates (CAP) showed a clear distinction between the two groups. A high relative abundance of genes associated with cofactors, virulence, phages and fatty acids were present in the non-impacted sediments, accounting for 45.7 % of the overall dissimilarity. In the hydrocarbon-impacted sites, a high relative abundance of genes associated with iron acquisition and metabolism, dormancy and sporulation, motility, metabolism of aromatic compounds and cell signalling were observed, accounting for 22.3 % of the overall dissimilarity. These results suggest a major shift in functionality has occurred with pathways essential to the degradation of hydrocarbons becoming overrepresented at the expense of other, less essential metabolisms. PMID:24282619

  6. High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons

    KAUST Repository

    González-Gaya, Belén

    2016-05-16

    Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

  7. Influence of chlorine atoms in bay positions of perylene-tetracarboxylic acids on their spectral properties in Langmuir-Blodgett films

    Science.gov (United States)

    Piosik, Emilia; Synak, Anna; Martyński, Tomasz

    2018-01-01

    The influence of chlorine atoms in the bay positions of the perylene-3,4,9,10-tetracarboxylic acids with the different alkyl chains length on their spectral properties in monomolecular films has been studied. The chlorinated (PCln) and for comparison non-chlorinated (Pn) perylene derivatives were deposited onto quartz plates using a Langmuir-Blodgett (LB) technique. The absorption spectra showed that the PCln and Pn dyes form in monolayers the I- and J-type aggregates, respectively. In turn, their steady-state and time-resolved emission spectra revealed presence of two emitter types, which we assigned to monomers and excimers. The luminescence lifetimes of the PCln monomers and excimers determined with a time-correlated single photon counting method (TCSPC) are significantly shorter than these obtained for the same emitter types in the Pn monolayers. In the case of the chlorinated dyes, the contribution of the monomer emission dominates over the excimer emission and is almost independent from the alkyl chain length. By contrast, the share of the Pn monomer emission increases strongly with a number of carbon atoms in their hydrocarbon chains. The luminescence quantum yields (LQY) of the Pn and PCln monolayers measured in an integrating sphere are in the range of 0.06-0.11. The presented results reveal that the PCln dyes exhibit lower tendency for aggregation than the non-chlorinated derivatives. It can be explained by limited intermolecular interaction between neighbouring PCln molecules caused by deformation of the perylene core as a result of strongly electronegative chlorine atoms in the bay positions of these dyes. Moreover, the strong influence of the alkyl chain length on the Pn aggregation contrary to the case of the PCln derivatives was observed.

  8. Spatial and vertical distribution of short chain chlorinated paraffins in soils from wastewater irrigated farmlands.

    Science.gov (United States)

    Zeng, Lixi; Wang, Thanh; Han, Wenya; Yuan, Bo; Liu, Qian; Wang, Yawei; Jiang, Guibin

    2011-03-15

    Chlorinated paraffins (CPs) are one of the most complex groups of halogenated contaminants in the environment. However, studies of short chain CPs (SCCPs) in China are very scarce. In this study, the concentrations and distribution of SCCPs in farm soils from a wastewater irrigated area in China were investigated. SCCPs were detected in all topsoil samples, with the sum of the concentrations (ΣSCCPs) in the range of 159.9-1450 ng/g (dry weight, dw). A noticeable spatial trend and specific congener distribution were observed in the wastewater irrigated farmland. Soil vertical profiles showed that ΣSCCP concentrations below the plowed layer decreased exponentially and had a significant positive relationship (R(2) > 0.83) with total organic carbon in soil cores. Furthermore, soil vertical distributions indicated that lower chlorinated (Cl(5-6)) and shorter chain (C(10-12)) congeners are more prone to migrate to deeper soil layers compared to highly chlorinated and longer chain congeners. This work demonstrated that effluents from sewage treatment plants (STPs) could be a significant source of SCCPs to the ambient environment and wastewater irrigation can lead to higher accumulation of SCCPs in farm soils.

  9. Prevalence of Simkania negevensis in chlorinated water from spa swimming pools and domestic supplies.

    Science.gov (United States)

    Donati, M; Cremonini, E; Di Francesco, A; Dallolio, L; Biondi, R; Muthusamy, R; Leoni, E

    2015-04-01

    This study aimed to investigate the prevalence of Simkania negevensis in the chlorinated water of spa swimming pools and domestic network systems. A total of 10 and 36 samples were collected from two domestic water supplies and four spa facilities, respectively. Simkania negevensis was isolated in Acanthamoeba castellanii monolayers and detected by Gimenez staining and immunofluorescence test. Simkania negevensis DNA, extracted from the positive samples, was confirmed by a nested PCR assay followed by sequencing. Simkania negevensis was detected in 41·3% of samples (domestic water: 50%; untreated spa supply water: 25%; chlorinated spa pool water: 42·9%) from all the examined water systems in successive samplings performed in 1 year. The presence of S. negevensis was not correlated with the counts of Heterotrophic Bacteria and Pseudomonas aeruginosa. Unlike Legionella spp., which were never isolated from the swimming-pool water samples, S. negevensis was also detected in chlorinated spa water. This investigation shows that Simkania is widespread in natural and man-made aquatic environments, which may represent possible sources of infection: in the swimming pools, in particular, the aerosol generated by the water movement could increase the risk of inhalation of infected particles. This study represents the first evidence of the presence of S. negevensis in spa pool water. Sero-epidemiological surveys on spa users could help to clarify its transmission in this environment. © 2015 The Society for Applied Microbiology.

  10. Chlorinated and nitrogenous disinfection by-product formation from ozonation and post-chlorination of natural organic matter surrogates.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Rifai, Omar; Ali, Hussain; Graham, Nigel J D

    2014-09-01

    Ozonation before chlorination is associated with enhanced formation of chloropicrin, a halonitromethane disinfection by-product (DBP), during drinking water treatment. In order to elucidate reasons for this, five natural organic matter (NOM) surrogates were treated using both chlorination and ozonation-chlorination under controlled laboratory conditions. Selected surrogates comprised two phenolic compounds, two free amino acids and one dipeptide; these were resorcinol, 3-aminophenol, L-aspartic acid, β-alanine and ala-ala, respectively. Quantified DBPs included chloropicrin, chloroform, dichloroacetonitrile and trichloroacetonitrile. Relative to chlorination alone, increases in the formation of chloropicrin from ozonation-chlorination varied from 138% for 3-aminophenol to 3740% for ala-ala for the four amine surrogates. This indicates that ozone is more effective than chlorine in mediating a rate-limiting oxidation step in chloropicrin formation, most plausibly involving conversion of an amine group to a nitro group. While both hydrophilic and hydrophobic surrogates acted as chloropicrin precursors, ala-ala was the most reactive precursor following ozonation-chlorination. Since peptides are far commoner in drinking water sources than free amino acids, further research into chemical oxidation of these species by ozone and chlorine is recommended. In contrast, oxidation with ozone prior to chlorination reduced chloroform formation moderately for the two phenolic compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Micellar partitioning and its effects on Henry's law constants of chlorinated solvents in anionic and nonionic surfactant solutions.

    Science.gov (United States)

    Zhang, Chunlong; Zheng, Gang; Nichols, Courtney M

    2006-01-01

    Micellar partitioning of volatile chlorinated hydrocarbons in surfactant solutions and its effects on vapor-liquid equilibrium is fundamental to the overall design and implementation of surfactant-enhanced aquifer remediation. Surfactant micelles greatly enhance contaminant recovery from the subsurface; however, the reduced volatility of organic compounds compromises the aboveground treatment of surfactant-laden wastewaters using air-stripping process. Batch equilibrium tests were performed to acquire micellar partition coefficients (Km) and apparent Henry's law constants (H*) of three prominent groundwater contaminants (tetrachloroethylene, trichloroethylene, cis-dichlorethylene) in the presence of two anionic surfactants (sodium dodecyl sulfate, SDS; sodium dodecylbenzene sulfonate, SDBS) and two nonionic surfactants (Triton X-100 and Tween 80). The H* values were significantly reduced in the presence of all four surfactants over their critical micelle concentrations (cmc's). On a cmc basis, the anionic surfactant SDS had the greatest effect on H*, followed by SDBS, Triton X-100, and Tween 80. Anionic surfactants decreased H* to an order of magnitude lower than nonionic surfactants, although nonionic surfactants decreased the H* at concentrations significantly lower than the anionic surfactants due to their lower cmc's. Nonionic surfactants present higher Km and molar solubilization ratio than anionic surfactants. Tetrachloroethylene has the highest Km values among three chlorinated solvents, which agrees well with the hydrophobicity (Kow) of these chemicals. An empirical correlation between log Km and log Kow is developed on the basis of data from this study and the Km values reported for a number of chlorinated and nonchlorinated hydrocarbons. Equilibrium data were also tested against three sets of models that describe the partitioning of volatile compounds in vapor-water-micelle phases. Applications of these models in experimentally determining Km from batch

  12. Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice

    Science.gov (United States)

    Sasada, Tatsunari; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Takakura, Yuji; Kawaguchi, Yasuo; Sotomaru, Yusuke; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

    2015-01-01

    The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc) knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma—caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc+/flox, abbreviated to CPC;Apc) or microsatellite (CDX2P9.5-G19Cre;Apcflox/flox and CDX2P9.5-G22Cre;Apcflox/flox) instability, respectively—were administered chlorinated (10.0 mg/L chlorine) or tap (0.7 mg/L chlorine) water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apcflox/flox and CDX2P9.5-G22Cre;Apcflox/flox mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to differences in

  13. Aqueous chlorination of carbamazepine: kinetic study and transformation product identification.

    Science.gov (United States)

    Soufan, M; Deborde, M; Delmont, A; Legube, B

    2013-09-15

    Carbamazepine reactivity and fate during chlorination was investigated in this study. From a kinetic standpoint, a third-order reaction (first-order relative to the CBZ concentration and second-order relative to the free chlorine concentration) was observed at neutral and slightly acidic pH, whereas a second-order reaction (first order relative to the CBZ concentration and first order relative to the free chlorine concentration) was noted under alkaline conditions. In order to gain insight into the observed pH-dependence of the reaction order, elementary reactions (i.e. reactions of Cl2, Cl2O, HOCl with CBZ and of ClO(-) with CBZ or of HOCl with the ionized form of CBZ) were highlighted and second order rate constants of each of them were calculated. Close correlations between the experimental and modeled values were obtained under these conditions. Cl2 and Cl2O were the main chlorination agents at neutral and acidic pH. These results indicate that, for a 1 mg/L free chlorine concentration and 1-10 mg/L chloride concentration at pH 7, halflives about 52-69 days can be expected. A low reactivity of chlorine with CBZ could thus occur under the chlorination steps used during water treatment. From a mechanistic viewpoint, several transformation products were observed during carbamazepine chlorination. As previously described for the chlorination of polynuclear aromatic or unsaturated compounds, we proposed monohydroxylated, epoxide, diols or chlorinated alcohol derivatives of CBZ for the chemical structures of these degradation products. Most of these compounds seem to accumulate in solution in the presence of excess chlorine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Skeletal and chlorine effects on 13C-NMR chemical shifts of chlorinated polycyclic systems

    Directory of Open Access Journals (Sweden)

    Costa V.E.U.

    1999-01-01

    Full Text Available In order to establish a comparative analysis of chemical shifts caused by ring compression effects or by the presence of a chlorine atom on strained chlorinated carbons, a series of the chlorinated and dechlorinated polycyclic structures derived from "aldrin" (5 and "isodrin" (14 was studied. Compounds were classified in four different groups, according to their conformation and number of ring such as: endo-exo and endo-endo tetracyclics, pentacyclics and hexacyclics. The 13C chemical shift comparison between the chlorinated and dechlorinated compounds showed that when C-9 and C-10 are olefinic carbons, it occurs a shielding of 0.5-2.4 ppm for endo-endo tetracyclics and of 4.7-7.6 ppm for endo-exo tetracyclic. The chemical shift variation for C-11 reaches 49-53 ppm for endo-exo and endo-endo tetracyclics, 54 ppm for pentacyclic and 56-59 ppm for hexacyclic compounds. From these data, it was possible to observe the influence of ring compression on the chemical shifts.

  15. Cellular Response of the Amoeba Acanthamoeba castellanii to Chlorine, Chlorine Dioxide, and Monochloramine Treatments ▿

    Science.gov (United States)

    Mogoa, Emerancienne; Bodet, Charles; Morel, Franck; Rodier, Marie-Hélène; Legube, Bernard; Héchard, Yann

    2011-01-01

    Acanthamoeba castellanii is a free-living amoebae commonly found in water systems. Free-living amoebae might be pathogenic but are also known to bear phagocytosis-resistant bacteria, protecting these bacteria from water treatments. The mode of action of these treatments is poorly understood, particularly on amoebae. It is important to examine the action of these treatments on amoebae in order to improve them. The cellular response to chlorine, chlorine dioxide, and monochloramine was tested on A. castellanii trophozoites. Doses of disinfectants leading to up to a 3-log reduction were compared by flow cytometry and electron microscopy. Chlorine treatment led to size reduction, permeabilization, and retraction of pseudopods. In addition, treatment with chlorine dioxide led to a vacuolization of the cytoplasm. Monochloramine had a dose-dependent effect. At the highest doses monochloramine treatment resulted in almost no changes in cell size and permeability, as shown by flow cytometry, but the cell surface became smooth and dense, as seen by electron microscopy. We show that these disinfectants globally induced size reduction, membrane permeabilization, and morphological modifications but that they have a different mode of action on A. castellanii. PMID:21602398

  16. Cellular response of the amoeba Acanthamoeba castellanii to chlorine, chlorine dioxide, and monochloramine treatments.

    Science.gov (United States)

    Mogoa, Emerancienne; Bodet, Charles; Morel, Franck; Rodier, Marie-Hélène; Legube, Bernard; Héchard, Yann

    2011-07-01

    Acanthamoeba castellanii is a free-living amoebae commonly found in water systems. Free-living amoebae might be pathogenic but are also known to bear phagocytosis-resistant bacteria, protecting these bacteria from water treatments. The mode of action of these treatments is poorly understood, particularly on amoebae. It is important to examine the action of these treatments on amoebae in order to improve them. The cellular response to chlorine, chlorine dioxide, and monochloramine was tested on A. castellanii trophozoites. Doses of disinfectants leading to up to a 3-log reduction were compared by flow cytometry and electron microscopy. Chlorine treatment led to size reduction, permeabilization, and retraction of pseudopods. In addition, treatment with chlorine dioxide led to a vacuolization of the cytoplasm. Monochloramine had a dose-dependent effect. At the highest doses monochloramine treatment resulted in almost no changes in cell size and permeability, as shown by flow cytometry, but the cell surface became smooth and dense, as seen by electron microscopy. We show that these disinfectants globally induced size reduction, membrane permeabilization, and morphological modifications but that they have a different mode of action on A. castellanii.

  17. Scenarios Evaluation Tool for Chlorinated Solvent MNA

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, Karen; Michael J. Truex; Charles J. Newell; Brian Looney

    2007-02-28

    Over the past three decades, much progress has been made in the remediation of chlorinated solvents from the subsurface. Yet these pervasive contaminants continue to present a significant challenge to the U.S. Department of Energy (DOE), other federal agencies, and other public and private organizations. The physical and chemical properties of chlorinated solvents make it difficult to rapidly reach the low concentrations typically set as regulatory limits. These technical challenges often result in high costs and long remediation time frames. In 2003, the DOE through the Office of Environmental Management funded a science-based technical project that uses the U.S. Environmental Protection Agency's technical protocol (EPA, 1998) and directives (EPA, 1999) on Monitored Natural Attenuation (MNA) as the foundation on which to introduce supporting concepts and new scientific developments that will support remediation of chlorinated solvents based on natural attenuation processes. This project supports the direction in which many site owners want to move to complete the remediation of their site(s), that being to complete the active treatment portion of the remedial effort and transition into MNA. The overarching objective of the effort was to examine environmental remedies that are based on natural processes--remedies such as Monitored Natural Attenuation (MNA) or Enhanced Attenuation (EA). The research program did identify several specific opportunities for advances based on: (1) mass balance as the central framework for attenuation based remedies, (2) scientific advancements and achievements during the past ten years, (3) regulatory and policy development and real-world experience using MNA, and (4) exploration of various ideas for integrating attenuation remedies into a systematic set of ''combined remedies'' for contaminated sites. These opportunities are summarized herein and are addressed in more detail in referenced project documents and

  18. Chlorinated tyrosine derivatives in insect cuticle

    DEFF Research Database (Denmark)

    Andersen, Svend Olav

    2004-01-01

    A method for quantitative measurement of 3-monochlorotyrosine and 3,5-dichlorotyrosine in insect cuticles is described, and it is used for determination of their distribution in various cuticular regions in nymphs and adults of the desert locust, Schistocerca gregaria. The two chlorinated tyrosine...... during sample hydrolysis. Mono- and dichlorotyrosine are also present in cuticular samples from other insect species, such as the beetle, Tenebrio molitor, the moth Hyalophora cecropia, the cockroach Blaberus craniifer, and the bug Rhodnius prolixus, but not in the sclerotized puparial cuticle...

  19. Immunogenic cell death due to a new photodynamic therapy (PDT) with glycoconjugated chlorin (G-chlorin).

    Science.gov (United States)

    Tanaka, Mamoru; Kataoka, Hiromi; Yano, Shigenobu; Sawada, Takuya; Akashi, Haruo; Inoue, Masahiro; Suzuki, Shugo; Inagaki, Yusuke; Hayashi, Noriyuki; Nishie, Hirotada; Shimura, Takaya; Mizoshita, Tsutomu; Mori, Yoshinori; Kubota, Eiji; Tanida, Satoshi; Takahashi, Satoru; Joh, Takashi

    2016-07-26

    Both the pre-apoptotic exposure to calreticulin (CRT) and the post-apoptotic release of high-mobility group box 1 protein (HMGB1) are required for immunogenic cell death. Photodynamic therapy (PDT) uses non-toxic photosensitizers and visible light at a specific wavelength in combination with oxygen to produce cytotoxic reactive oxygen species that kill malignant cells by apoptosis and/or necrosis, shut down the tumor microvasculature, and stimulate the host immune system. We have previously shown that glycoconjugated chlorin (G-chlorin) has superior cancer cell selectivity and effectively suppresses the growth of xenograft tumors. In the present study, we evaluated the immunogenicity of PDT with G-chlorin treatment in colon cancer cells. PDT with G-chlorin suppressed CT26 (mouse colon cancer cells) tumor growth considerably more efficiently in immunocompetent mice (wild-type mice, allograft model) than in immune-deficient mice (nude mice, xenograft model), although control treatments were not different between the two. This treatment also induced CRT translocation and HMGB1 release in cells, as shown by western blot and immunofluorescence staining. To evaluate the use of PDT-treated cells as a tumor vaccine, we employed a syngeneic mouse tumor model (allograft model). Mice inoculated with PDT-treated CT26 cells were significantly protected against a subsequent challenge with live CT26 cells, and this protection was inhibited by siRNA for CRT or HMGB1. In conclusion, PDT with G-chlorin treatment induced immunogenic cell death in a mouse model, where the immunogenicity of this treatment was directed by CRT expression and HMGB1 release.

  20. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang, Dali [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

    2011-11-29

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  1. Process and Kinetic Mechanism of Elimination of Chlorine ...

    African Journals Online (AJOL)

    the parameters controlling the bleaching process are protected as know-how by manufacturers, so the chlorine amount in bleached shellac varies significantly in different products. The chlorine content of bleached shellac prepared by some manufacturers in China is higher than that of the products obtained by importation, ...

  2. Assessment of a chlorine dioxide proprietary product for water and ...

    African Journals Online (AJOL)

    Chlorine on its own is adequate for many, if not most, potable water pre-oxidation and disinfection systems at plants where the application is straightforward. Similarly, most wastewater plants can be disinfected by chlorine in one of its commercially available forms. However, when more intense pre-oxidation is required or ...

  3. UASB reactor effluent disinfection by ozone and chlorine

    NARCIS (Netherlands)

    Ribeiro da Silvia, G.H.; Bruning, H.; Gerrity, D.; Daniel, L.A.

    2015-01-01

    This research studied the sequential ozone and chlorine process with respect to, the inactivation of indicator bacteria and the formation of ozone disinfection byproducts in sanitary wastewater effluent. The applied ozone doses were 5, 8 and 10 mg.O3.L-1, followed by chlorine doses of 10, 20 and 30

  4. Chlorine isotope fractionation between chloride (Cl-) and dichlorine (Cl2)

    Science.gov (United States)

    Giunta, Thomas; Labidi, Jabrane; Eggenkamp, Hans G. M.

    2017-09-01

    The use of chlorine stable isotopes (35Cl and 37Cl) can help to constrain natural processes that involve chlorine species with different oxidation states. Theoretical studies based on thermodynamic and quantum mechanical approaches predict large isotope fractionation during redox reactions but to date, these reactions have not been studied experimentally.

  5. Dense chlorinated solvents and other DNAPLs in groundwater

    DEFF Research Database (Denmark)

    Broholm, K.

    1996-01-01

    Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996......Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996...

  6. Chlorine Dioxide Induced Multiple Chemical Sensitivity: MMPI Validity Problems.

    Science.gov (United States)

    Tentoni, Stuart C.

    This paper discusses Minnesota Multiphasic Personality Inventory (MMPI) data obtained from individuals exposed to chlorine dioxide in the workplace who developed Multiple Chemical Sensitivity Syndrome. The paper explores current research on chlorine dioxide exposed persons who were misdiagnosed on the basis of MMPI interpretations. Difficulties…

  7. Chlorine Analysis - Water. Training Module 5.260.2.77.

    Science.gov (United States)

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with the procedures for chlorine residual analysis. It includes objectives, an instructor guide, and student handouts. The module addresses the determination of combined and free residual chlorine in water supply samples using three…

  8. Quality of Chlorine-Based Antiseptics and Disinfectants Circulating ...

    African Journals Online (AJOL)

    Background: Chlorine-based antiseptics and disinfectants have a stability problem especially when formulated as aqueous solutions. They tend to decompose slowly liberating chlorine on storage. Despite this instability, these products are commonly manufactured and labeled with a long shelf-life. Thus the labeled content ...

  9. Chlorine characterization and thermal behavior in MSW and RDF.

    Science.gov (United States)

    Ma, Wenchao; Hoffmann, Gaston; Schirmer, Mattias; Chen, Guanyi; Rotter, Vera Susanne

    2010-06-15

    Chlorine, as a key element causing high temperature corrosion and low efficiency in waste-to-energy plants, and its thermal behavior has widely drawn attention. In this study, the chlorine content in eight fractions of municipal solid waste (MSW) was quantified and characterized using five analytical methods. The influence of the operating temperature, and fuel additives like sulfur and silica on the volatilization of chlorine in combustion process was also investigated. The results showed: these fractions cover a wide range of chlorine content from 0.1 wt.% in wood to >6 wt.% in non-packaging plastics (dry basis). Polyvinylchloride (PVC) from packaging, electrical wire insulation etc. in plastics and chloride salts (mainly NaCl) in kitchen waste are the main sources of organic and inorganic chlorine. The increase of the operating temperature from 700 degrees C to 1000 degrees C has more influence on the HCl formation for kitchen waste than that for PVC. Sulfur addition leads to 20-40% higher HCl formation rate in most fractions. Silica supports the chlorine release at relatively low temperatures between 700 degrees C and 850 degrees C. These findings enhance to understand the thermal behavior of chlorine in MSW and RDF (refuse derived fuel) in waste-to-energy plants and lead to the suggestions for a fuel management for waste derived fuels in order to avoid chlorine induced corrosion. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Effectiveness of chlorination and ozonation methods on pure ...

    African Journals Online (AJOL)

    2005-01-16

    Jan 16, 2005 ... Chlorination is a very useful control method of filamentous bulking in activated sludge systems; however, it favours forma- tion of undesirable compounds such as trihalomethanes. Other oxidants, such as ozone, could be used for bulking control. In view of the fact that chlorine and ozone are both ...

  11. Hydrochloric Acid and the Chlorine Budget of the Lower Stratosphere

    Science.gov (United States)

    Webster, C.; May, R.; Jaegle, L.; Hu, H.; Sander, S.; Gunson, M.; Toon, G.; Russell, J., III; Stimpfle, R.; Koplow, J.; hide

    1994-01-01

    Concentrations of hc1 measured in the lower stratosphere in 1993 by the ALIAS instrument on the ER-2 aircraft reveal that only 40% of inorganic chlorine (CL sub y, inferred from in situ measurements of organic chlorinated source gases) is present as HC1, significantly lower than model predictions.

  12. Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China); Qiao, Juan, E-mail: qjuan@tsinghua.edu.cn [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Lu, Yun, E-mail: luyun@tsinghua.edu.cn [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China)

    2016-02-13

    Highlights: • Chlorination is effective to reduce the inflammation inducing capacity of LPS in lung. • LAL-detected endotoxin activity is not correlated to the potency of inflammation induction. • Alkyl chain of LPS was chlorinated in chlorination process. • LPS aggregate size decreases after chlorination. - Abstract: Lipopolysaccharide (LPS, also called endotoxin) is a pro-inflammatory constituent of gram negative bacteria and cyanobacteria, which causes a potential health risk in the process of routine urban application of reclaimed water, such as car wash, irrigation, scenic water refilling, etc. Previous studies indicated that the common disinfection treatment, chlorination, has little effect on endotoxin activity removal measured by Limulus amebocyte lysate (LAL) assay. However, in this study, significant decrease of acute inflammatory effects was observed in mouse lung, while LAL assay still presented a moderate increase of endotoxin activity. To explore the possible mechanisms, the nuclear magnetic resonance (NMR) results showed the chlorination happened in alkyl chain of LPS molecules, which could affect the interaction between LPS and LPS-binding protein. Also the size of LPS aggregates was found to drop significantly after treatment, which could be another results of chlorination caused polarity change. In conclusion, our observation demonstrated that chlorination is effective to reduce the LPS induced inflammation in lung, and it is recommended to use health effect-based methods to assess risk removal of water treatment technologies.

  13. 75 FR 23303 - Chlorinated Isocyanurates From China and Spain

    Science.gov (United States)

    2010-05-03

    ... COMMISSION Chlorinated Isocyanurates From China and Spain AGENCY: United States International Trade... isocyanurates from China and Spain. SUMMARY: The Commission hereby gives notice that it has instituted reviews... revocation of the antidumping duty orders on chlorinated isocyanurates from China and Spain would be likely...

  14. 75 FR 51113 - Chlorinated Isocyanurates From China and Spain

    Science.gov (United States)

    2010-08-18

    ... COMMISSION Chlorinated Isocyanurates From China and Spain AGENCY: United States International Trade... chlorinated isocyanurates from China and Spain. SUMMARY: The Commission hereby gives notice of the scheduling... from China and Spain would be likely to lead to continuation or recurrence of material injury within a...

  15. 78 FR 66767 - Chlorinated Isocyanurates From China and Japan

    Science.gov (United States)

    2013-11-06

    ... COMMISSION Chlorinated Isocyanurates From China and Japan Determinations On the basis of the record \\1... injured by reason of imports from China and Japan of chlorinated isocyanurates, provided for in... than fair value (LTFV) from Japan and subsidized by the Government of China.\\2\\ \\1\\ The record is...

  16. Monitoring Residual Chlorine Decay and Coliform Contamination in ...

    African Journals Online (AJOL)

    Michael Horsfall

    by assessing five storage reservoirs and four consumer taps. The aim was to ... using sedimentation, filtration and sterilisation or disinfection. .... Reservoir management (e.g. cleanliness) also contributed to chlorine loss. The residual chlorine concentration pattern in the reservoirs (Figures 1 and 2) are similar to other ...

  17. Experimental and Theoretical Studies of Atmosphereic Inorganic Chlorine Chemistry

    Science.gov (United States)

    Sander, Stanley P.; Friedl, Randall R.

    1993-01-01

    Over the last five years substantial progress has been made in defining the realm of new chlorine chemistry in the polar stratosphere. Application of existing experimental techniques to potentially important chlorine-containing compounds has yielded quantitative kinetic and spectroscopic data as well as qualitative mechanistic insights into the relevant reactions.

  18. Altered UV absorbance and cytotoxicity of chlorinated sunscreen agents.

    Science.gov (United States)

    Sherwood, Vaughn F; Kennedy, Steven; Zhang, Hualin; Purser, Gordon H; Sheaff, Robert J

    2012-12-01

    Sunscreens are widely utilized due to the adverse effects of ultraviolet (UV) radiation on human health. The safety of their active ingredients as well as that of any modified versions generated during use is thus of concern. Chlorine is used as a chemical disinfectant in swimming pools. Its reactivity suggests sunscreen components might be chlorinated, altering their absorptive and/or cytotoxic properties. To test this hypothesis, the UV-filters oxybenzone, dioxybenzone, and sulisobenzone were reacted with chlorinating agents and their UV spectra analyzed. In all cases, a decrease in UV absorbance was observed. Given that chlorinated compounds can be cytotoxic, the effect of modified UV-filters on cell viability was examined. Chlorinated oxybenzone and dioxybenzone caused significantly more cell death than unchlorinated controls. In contrast, chlorination of sulisobenzone actually reduced cytotoxicity of the parent compound. Exposing a commercially available sunscreen product to chlorine also resulted in decreased UV absorbance, loss of UV protection, and enhanced cytotoxicity. These observations show chlorination of sunscreen active ingredients can dramatically decrease UV absorption and generate derivatives with altered biological properties.

  19. Hydrocarbons preserved in a ~2.7 Ga outcrop sample from the Fortescue Group, Pilbara Craton, Western Australia.

    Science.gov (United States)

    Hoshino, Y; Flannery, D T; Walter, M R; George, S C

    2015-03-01

    The hydrocarbons preserved in an Archean rock were extracted, and their composition and distribution in consecutive slices from the outside to the inside of the rock were examined. The 2.7 Ga rock was collected from the Fortescue Group in the Pilbara region, Western Australia. The bitumen I (solvent-extracted rock) and bitumen II (solvent-extracted hydrochloric acid-treated rock) fractions have different hydrocarbon compositions. Bitumen I contains only trace amounts of aliphatic hydrocarbons and virtually no aromatic hydrocarbons. In contrast, bitumen II contains abundant aliphatic and aromatic hydrocarbons. The difference seems to reflect the weathering history and preservational environment of the investigated rock. Aliphatic hydrocarbons in bitumen I are considered to be mainly from later hydrocarbon inputs, after initial deposition and burial, and are therefore not indigenous. The lack of aromatic hydrocarbons in bitumen I suggests a severe weathering environment since uplift and exposure of the rock at the Earth's surface in the Cenozoic. On the other hand, the high abundance of aromatic hydrocarbons in bitumen II suggests that bitumen II hydrocarbons have been physically isolated from removal by their encapsulation within carbonate minerals. The richness of aromatic hydrocarbons and the relative scarcity of aliphatic hydrocarbons may reflect the original compositions of organic materials biosynthesised in ancient organisms in the Archean era, or the high thermal maturity of the rock. Cyanobacterial biomarkers were observed in the surficial slices of the rock, which may indicate that endolithic cyanobacteria inhabited the surface outcrop. The distribution of aliphatic and aromatic hydrocarbons implies a high thermal maturity, which is consistent with the lack of any specific biomarkers, such as hopanes and steranes, and the prehnite-pumpellyite facies metamorphic grade. © 2014 John Wiley & Sons Ltd.

  20. Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach

    Science.gov (United States)

    Cutshall, N. H.; Gilmore, T.; Looney, B. B.; Vangelas, K. M.; Adams, K. M.; Sink, C. H.

    2006-05-01

    Like many US industries and businesses, the Department of Energy (DOE) is responsible for remediation and restoration of soils and ground water contaminated with chlorinated ethenes. Monitored Natural Attenuation (MNA) is an attractive remediation approach and is probably the universal end-stage technology for removing such contamination. Since 2003 we have carried out a multifaceted program at the Savannah River Site designed to advance the state of the art for MNA of chlorinated ethenes in soils and groundwater. Three lines of effort were originally planned: 1) Improving the fundamental science for MNA, 2) Promoting better characterization and monitoring (CM) techniques, and 3) Advancing the regulatory aspects of MNA management. A fourth line, developing enhanced attenuation methods based on sustainable natural processes, was added in order to deal with sites where the initial natural attenuation capacity cannot offset contaminant loading rates. These four lines have been pursued in an integrated and mutually supportive fashion. Many DOE site-cleanup program managers view CM as major expenses, especially for natural attenuation where measuring attenuation is complex and the most critical attenuation mechanisms cannot be determined directly. We have reviewed new and developing approaches to CM for potential application in support of natural attenuation of chlorinated hydrocarbons in ground water at DOE sites (Gilmore, Tyler, et al., 2006 WSRC-TR- 2005-00199). Although our project is focused on chlorinated ethenes, many of the concepts and strategies are also applicable to a wider range of contaminants including radionuclides and metals. The greatest savings in CM are likely to come from new management approaches. New approaches can be based, for example, on conceptual models of attenuation capacity, the ability of a formation to reduce risks caused by contaminants. Using the mass balance concept as a guide, the integrated mass flux of contaminant is compared to