WorldWideScience

Sample records for chlorinated aromatic pollutants

  1. 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 Netherl

  2. Mass transfer properties of chlorinated aromatic polyamide reverse osmosis membranes

    OpenAIRE

    Ettori, Axel; Gaudichet-Maurin, Emmanuelle; Aimar, Pierre; Causserand, Christel

    2012-01-01

    International audience; Water (A) and solute (B) permeability of aromatic polyamide (PA) reverse osmosis membranes (RO) were monitored under varying applied pressure, solute nature and concentration to assess their evolution after exposure of the membrane to free chlorine. Above a threshold value of 400 ppm h HOCl water permeability was influenced by permeation conditions during both filtration of ultrapure water (UP water) and reverse osmosis of salts performed sequentially. Water permeabili...

  3. Safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water

    Energy Technology Data Exchange (ETDEWEB)

    Taymaz, K.; Williams, D.T.; Benoit, F.M.

    1979-01-01

    The safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water and industrial wastewaters in the US was studied by observing the reactions of naphthalene and methylnaphthalenes in essentially chlorine-free, aqueous chlorine dioxide solutions. Naphthalene and methylnaphthalenes yielded chlorinated derivatives and oxidation products. Further research is recommended.

  4. Atmospheric chlorinated polycyclic aromatic hydrocarbons in East Asia.

    Science.gov (United States)

    Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Hayakawa, Kazuichi; Toriba, Akira

    2014-09-01

    This study estimates atmospheric concentrations of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and polycyclic aromatic hydrocarbons (PAHs) in East Asia using a Gas Chromatograph with High Resolution Mass Spectrometer (GC-HRMS). ClPAHs are ubiquitously generated from PAHs through substitution, and some ClPAHs show higher aryl hydrocarbon receptor (AhR)-mediated activities than their parent PAHs. Atmospheric particles were collected using a high-volume air sampler equipped with a quartz-fiber filter. We determined the ClPAH concentrations of atmospheric particles collected in Japan (Sapporo, Sagamihara, Kanazawa, and Kitakyushu), Korea (Busan), and China (Beijing). The concentrations of ClPAHs were highest in the winter Beijing sample, where the total mean concentration was approximately 15-70 times higher than in the winter samples from Japan and Korea. The concentrations of Σ19ClPAHs and Σ9PAHs were significantly correlated in the Kanazawa and the Busan samples. This indicates that within those cities ClPAHs and PAHs share the same origin, implying direct chlorination of parent PAHs. Toxic equivalent concentrations (TEQs) of the total ClPAHs and PAHs were lowest in Kanazawa in the summer, reaching 1.18 and 2610fg-TEQm(-3) respectively, and highest in Beijing in the winter, reaching 627 and 4240000fg-TEQm(-3) respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Chlorinated paraffins: properties, uses, and pollution potential

    National Research Council Canada - National Science Library

    Zitko, V; Arsenault, E

    1974-01-01

    The chemistry and applications of high molecular weight paraffins (C10-C30, 20-70% chlorine) are reviewed and data on solvent partitioning, thin layer chromatography and biodegredation of chlorinated paraffins are presented...

  6. Size Distribution of Chlorinated Polycyclic Aromatic Hydrocarbons in Atmospheric Particles.

    Science.gov (United States)

    Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Nakano, Takeshi; Hata, Mitsuhiko; Furuuchi, Masami; Tang, Ning; Hayakawa, Kazuichi; Toriba, Akira

    2017-01-01

    The particle size distribution of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) in particulate matter (PM) in Japan is examined for the first time. PM was collected using a PM0.1 air sampler with a six-stage filter. PM was collected in October 2014 and January 2015 to observe potential seasonal variation in the atmospheric behavior and size of PM, including polycyclic aromatic hydrocarbons (PAHs) and ClPAHs. We found that the concentration of PAHs and ClPAHs between 0.5-1.0 μm and 1.0-2.5 μm markedly increase in January (i.e., the winter season). Among the ClPAHs, 1-ClPyrene and 6-ClBenzo[a]Pyrene were the most commonly occurring compounds; further, approximately 15% of ClPAHs were in the nanoparticle phase (<0.1 μm). The relatively high presence of nanoparticles is a potential human health concern because these particles can easily be deposited in the lung periphery. Lastly, we evaluated the aryl hydrocarbon receptor (AhR) ligand activity of PM extracts in each size fraction. The result indicates that PM < 2.5 μm has the strong AhR ligand activity.

  7. Potential of non-ligninolytic fungi in bioremediation of chlorinated and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Marco-Urrea, Ernest; García-Romera, Inmaculada; Aranda, Elisabet

    2015-12-25

    In previous decades, white-rot fungi as bioremediation agents have been the subjects of scientific research due to the potential use of their unspecific oxidative enzymes. However, some non-white-rot fungi, mainly belonging to the Ascomycota and Zygomycota phylum, have demonstrated their potential in the enzymatic transformation of environmental pollutants, thus overcoming some of the limitations observed in white-rot fungi with respect to growth in neutral pH, resistance to adverse conditions and the capacity to surpass autochthonous microorganisms. Despite their presence in so many soil and water environments, little information exists on the enzymatic mechanisms and degradation pathways involved in the transformation of hydrocarbons by these fungi. This review describes the bioremediation potential of non-ligninolytic fungi with respect to chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) and also shows known conversion pathways and the prospects for future research.

  8. Sonochemical Treatment of Water Polluted by Chlorinated Organocompounds. A Review

    Directory of Open Access Journals (Sweden)

    Olivier Louisnard

    2010-02-01

    Full Text Available As one of several types of pollutants in water, chlorinated compounds have been routinely subjected to sonochemical analysis to check the environmental applications of this technology. In this review, an extensive study of the influence of the initial concentration, ultrasonic intensity and frequency on the kinetics, degradation efficiency and mechanism has been analyzed. The sonochemical degradation follows a radical mechanism which yields a very wide range of chlorinated compounds in very low concentrations. Special attention has been paid to the mass balance comparing the results from several analytical techniques. As a conclusion, sonochemical degradation alone is not an efficient treatment to reduce the organic pollutant level in waste water.

  9. 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...

  10. Chlorinated aromatic compounds in a thermal process promoted by oxychlorination of ferric chloride.

    Science.gov (United States)

    Fujimori, Takashi; Takaoka, Masaki; Morisawa, Shinsuke

    2010-03-15

    The relationship between the formation of chlorinated aromatic (aromatic-Cl) compounds and ferric chloride in the solid phase during a thermal process motivated us to study the chemical characteristics of iron in a model solid sample, a mixture of FeCl(3) x 6H(2)O, activated carbon, and boron nitride, with increasing temperature. Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed drastic changes in the chemical form of amorphous iron, consistent with other analytical methods, such as X-ray diffraction using synchrotron radiation (SR-XRD) and Fourier-transform infrared (FT-IR) spectroscopy. Atomic-scale evidence of the chlorination of aromatic carbon was detected by Cl-K X-ray absorption near edge structure (XANES) spectroscopy. These results showed the thermal formation mechanism of aromatic-Cl compounds in the solid phase with ferric chloride. We attribute the formation of aromatic-Cl compounds to the chlorination of carbon, based on the oxychlorination reaction of FeCl(3) at temperatures in excess of ca. 300 degrees C, when the carbon matrix is activated by carbon gasification, catalyzed by Fe(2)O(3), and surface oxygen complexes (SOC) generated by a catalytic cycle of FeCl(2) and FeOCl. Chemical changes of trace iron in a thermal process may offer the potential to generate aromatic-Cl compounds in the solid phase.

  11. 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.

  12. Contrasting effects of sulfur dioxide on cupric oxide and chloride during thermochemical formation of chlorinated aromatics.

    Science.gov (United States)

    Fujimori, Takashi; Nishimoto, Yoshihiro; Shiota, Kenji; Takaoka, Masaki

    2014-12-01

    Sulfur dioxide (SO2) gas has been reported to be an inhibitor of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation in fly ash. However, other research has suggested little or no inhibitory effect of SO2 gas. Although these studies focused on reactions between SO2 gas and gas-phase chlorine (Cl) species, no attention was paid to thermochemical gas-solid reactions. In this study, we found contrasting effects of SO2 gas depending on the chemical form of copper (CuO vs CuCl2) with a solid-phase inorganic Cl source (KCl). Chlorinated aromatics (PCDD/Fs, polychlorinated biphenyls, and chlorobenzenes) increased and decreased in model fly ash containing CuO + KCl and CuCl2 + KCl, respectively, with increased SO2 injection. According to in situ Cu K-edge and S K-edge X-ray absorption spectroscopy, Cl gas and CuCl2 were generated and then promoted the formation of highly chlorinated aromatics after thermochemical reactions of SO2 gas with the solid-phase CuO + KCl system. In contrast, the decrease in aromatic-Cls in a CuCl2 + KCl system with SO2 gas was caused mainly by the partial sulfation of the Cu. The chemical form of Cu (especially the oxide/chloride ratio) may be a critical factor in controlling the formation of chlorinated aromatics using SO2 gas.

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

    African Journals Online (AJOL)

    SERVER

    2007-06-04

    Jun 4, 2007 ... that 93 to 95 percentage of chlorobenzene can be decomposed with in 10 min. The immobilized crude ... rmanikandan1968@yahoo.com. sole source of carbon ... Microbial degradation of chloro-substituted aromatics such as ...

  14. Degradation of Chlorinated Aromatic Compounds in UASB Reactors

    DEFF Research Database (Denmark)

    Christiansen, Nina; Hendriksen, Hanne Vang; Järvinen, Kimmo T.;

    1995-01-01

    Data on anaerobic degradation of chloroaromatic compounds in Upflow Anaerobic Sludge Blanket Reactors (UASB-reactor) are presented and compared. Special attention is given to the metabolic pathways for degradation of chlorinated phenols by granular sludge. Results indicate that PCP can be degraded...

  15. Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Wang, Xianli; Kang, Haiyan; Wu, Junfeng

    2016-05-01

    Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water.

  16. Polynuclear aromatic and chlorinated hydrocarbons in mussels from the coastal zone of Ushuaia, Tierra del Fuego, Argentina.

    Science.gov (United States)

    Amin, Oscar A; Comoglio, Laura I; Sericano, José L

    2011-03-01

    Mussels (Mytilus edulis chilensis) were collected from 12 coastal locations in Ushuaia Bay, Argentina, and the surrounding area in October 1999 and again in October 2003. Concentrations of polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and selected chlorinated pesticides were determined to assess the impact of a fast-growing population in the area. Total PAH concentrations ranged from 2.24 to an extremely high concentration of 2,420 µg/g lipid measured in mussels collected near an oil jetty used to discharge to shore storage tanks. The composition of PAHs in these samples indicates that the source of these compounds inside Ushuaia Bay is predominantly petrogenic, with some pyrogenic background, whereas mostly pyrogenic-related PAHs were evident in areas outside the bay. Total concentrations of PCBs ranged between 12.8 and 8,210 ng/g lipid, with the highest concentration, detected inside Ushuaia harbor, representing a 10-fold increase when compared with historical data. Chlorinated pesticides were detected at comparatively lower concentrations, with 4-4'- 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene being the most common. The aggressive increase in population and related activities observed in the city of Ushuaia over the last two decades might have affected the environmental quality of the local bay. Moreover, the oceanographic and atmospheric conditions existing in Ushuaia Bay and surrounding areas may favor the accumulation and long-term presence of these organic pollutants in all compartments of this fragile environment. Copyright © 2011 SETAC.

  17. 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.

  18. Evidence for strong, widespread chlorine radical chemistry associated with pollution outflow from continental Asia

    Science.gov (United States)

    Baker, Angela K.; Sauvage, Carina; Thorenz, Ute R.; van Velthoven, Peter; Oram, David E.; Zahn, Andreas; Brenninkmeijer, Carl A. M.; Williams, Jonathan

    2016-11-01

    The chlorine radical is a potent atmospheric oxidant, capable of perturbing tropospheric oxidative cycles normally controlled by the hydroxyl radical. Significantly faster reaction rates allow chlorine radicals to expedite oxidation of hydrocarbons, including methane, and in polluted environments, to enhance ozone production. Here we present evidence, from the CARIBIC airborne dataset, for extensive chlorine radical chemistry associated with Asian pollution outflow, from airborne observations made over the Malaysian Peninsula in winter. This region is known for persistent convection that regularly delivers surface air to higher altitudes and serves as a major transport pathway into the stratosphere. Oxidant ratios inferred from hydrocarbon relationships show that chlorine radicals were regionally more important than hydroxyl radicals for alkane oxidation and were also important for methane and alkene oxidation (>10%). Our observations reveal pollution-related chlorine chemistry that is both widespread and recurrent, and has implications for tropospheric oxidizing capacity, stratospheric composition and ozone chemistry.

  19. Sorption- and diffusion-associated isotope effects for chlorinated and non chlorinated aromatic hydrocarbons in a sediment pore water diffusion sampler

    Science.gov (United States)

    Passeport, E.; Chu, K.; Lacrampe Couloume, G.; Landis, R.; Lutz, E. J.; Mack, E. E.; West, K.; Sherwood Lollar, B.

    2013-12-01

    Compound Specific Isotope Analysis (CSIA) has gained prominence for evaluation of microbial and abiotic degradation processes governing the fate of organic contaminants in groundwater. At the sediment pore water interface, in wetland or river bottom sediments, variations in oxidation-reduction conditions can affect reaction mechanisms and hence the contaminant mass flux discharged to surface waters. Carbon isotope fractionation has been shown to be an important tool in identifying the effects of degradation and differentiating between different degradation pathways. To date, while passive diffusion samplers (commonly called 'peepers') have provided a powerful tool for high spatial resolution sampling for dissolved VOC across the sediment water interface, peepers' compatibility with CSIA has never been evaluated. The operating principle of peepers involves compound diffusion from the sediment pore water to the peeper chambers via a membrane. In this study, we evaluated the isotope effects of diffusion through, and possible adsorption to a polysulfone membrane for priority groundwater contaminants including chlorinated and non-chlorinated aromatic hydrocarbons. Chlorinated benzenes tend to accumulate in the food web and therefore represent a significant threat to water resources. This is due to their larger sorption coefficients (Koc) and higher hydrophobicity properties (logKow) compared to other commonly-studied compounds (e.g., chlorinated ethenes). Application of CSIA to BTEX and chlorinated ethenes has demonstrated that non-degradative processes (e.g., sorption, volatilization, diffusion) typically result in smaller carbon isotope fractionation compared to degradative processes that involve breaking bonds. The large sorption properties of chlorinated benzenes preclude a direct extrapolation to these compounds of existing data on sorption-associated isotope effects obtained on other compounds. To date, similar studies have not been done for chlorinated aromatics

  20. Microbial degradation of xenobiotic, aromatic pollutants in humic water.

    OpenAIRE

    Larsson, P.; Okla, L; Tranvik, L.

    1988-01-01

    The microbial degradation of a number of 14C-labeled, recalcitrant, aromatic pollutants, including trichloroguaiacol and di-, tri-, and pentachlorophenol, was investigated in aquatic model systems in the laboratory. Natural, mixed cultures of microorganisms in the water from a brown-water lake with a high content of humic compounds mineralized all of the tested substances to a higher degree than did microorganisms in the water from a clear-water lake. Dichlorophenol was the most rapidly degra...

  1. Technogenic pollution of pine forests by polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    O. V. Kalugina

    2015-08-01

    Full Text Available Anthropogenic pollution of boreal forests by polycyclic aromatic hydrocarbons was assessed by polycyclic aromatic hydrocarbon (PAH concentrations in needles of Scots pine (Pinus sylvestris L. trees growing in the vicinity of the Bratsk aluminium smelter – one of the largest aluminium smelters in the world. The fieldwork was performed in 2012–2013 on 34 index plots, set in mixed herb and sedge-mixed herb pine forests (mostly site class III. It is shown that the total accumulation of PAHs reaches its highest level (more than 6000 ng/g in pine needle samples collected at sites up to 3 km from the aluminium smelter. PAH total quantity decreases with increasing the distance from the pollution source and at a distance of 50 km reaches values close to background ones. The highest concentrations of PAHs were detected in needle samples collected at plots located from the plant in a direction corresponding to the prevailing emissions transfer. There was also detected a significant difference in compositions of individual PAHs: there were 18 compounds identified in samples collected near the aluminium smelter whereas only 6 compounds were identified in samples collected on the background territories. Among the PAHs accumulated in pine trees assimilation organs the substances with 3–4 aromatic rings (phenanthrene, fluoranthene, pyrene, chrysene were dominant with their total number reaching 90 % of the total. Compound with 5–6 aromatic rings (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[e]pyrene, perylene, indeno[1,2,3-c,d]pyrene, benzo[g, h, i]perylene, dibenz[a, h]anthracene.comprises a smaller proportion (from 6 to 27 % in total PAHs content. High concentrations of benzo[a]pyrene and perylene in needle samples collected in the vicinity of the aluminum smelter indicate technogenic character of forest pollution.

  2. Chlorinated Persistent Organic Pollutants, Obesity, and Type 2 Diabetes

    Science.gov (United States)

    Porta, Miquel; Jacobs, David R.; Vandenberg, Laura N.

    2014-01-01

    Persistent organic pollutants (POPs) are lipophilic compounds that travel with lipids and accumulate mainly in adipose tissue. Recent human evidence links low-dose POPs to an increased risk of type 2 diabetes (T2D). Because humans are contaminated by POP mixtures and POPs possibly have nonmonotonic dose-response relations with T2D, critical methodological issues arise in evaluating human findings. This review summarizes epidemiological results on chlorinated POPs and T2D, and relevant experimental evidence. It also discusses how features of POPs can affect inferences in humans. The evidence as a whole suggests that, rather than a few individual POPs, background exposure to POP mixtures—including organochlorine pesticides and polychlorinated biphenyls—can increase T2D risk in humans. Inconsistent statistical significance for individual POPs may arise due to distributional differences in POP mixtures among populations. Differences in the observed shape of the dose-response curves among human studies may reflect an inverted U-shaped association secondary to mitochondrial dysfunction or endocrine disruption. Finally, we examine the relationship between POPs and obesity. There is evidence in animal studies that low-dose POP mixtures are obesogenic. However, relationships between POPs and obesity in humans have been inconsistent. Adipose tissue plays a dual role of promoting T2D and providing a relatively safe place to store POPs. Large prospective studies with serial measurements of a broad range of POPs, adiposity, and clinically relevant biomarkers are needed to disentangle the interrelationships among POPs, obesity, and the development of T2D. Also needed are laboratory experiments that more closely mimic real-world POP doses, mixtures, and exposure duration in humans. PMID:24483949

  3. Photolysis of aromatic pollutants in clean and dirty ice

    Science.gov (United States)

    Kahan, T.; Malley, P.; Stathis, A.

    2015-12-01

    Anthropogenic aromatic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and substituted benzenes often become more toxic following atmospheric oxidation. Photolysis of these pollutants in ice can be much faster than that in aqueous solution, which might lead to higher carcinogenic loadings in snow-covered regions. In this work we investigate two things. First, we investigate whether toluene, which has been detected at very elevated concentrations near hydraulic fracturing operations, can undergo photolysis at ice surfaces. Toluene in aqueous solution does not absorb sunlight, so photolysis has not been considered a potential atmospheric fate. However, benzene was recently demonstrated to undergo a significant red shift in its absorbance at ice surfaces, leading to photolysis under environmentally-relevant conditions. Here we show that toluene also undergoes photolysis at ice surfaces. In a second set of experiments, we have investigated the effects of organic matter on the photolysis kinetics ofPAHs in ice and at ice surfaces. We found that very small loadings of hydrophobic organics such as octanol can significantly suppress PAH photolysis kinetics in ice, but that the primary effect of the more soluble fulvic acid is competitive photon absorption. Our results show that photochemistry of anthropogenic pollutants can follow very different mechanisms and kinetics in ice than in aqueous solution, and that the photochemical fate of these pollutants depends strongly on the composition of the snow. These results have implications for pollutant fate and human health in a wide range of snow-covered environments including remote areas, cities, and regions near gas and oil extraction operations.

  4. Ambient air pollution by aromatic hydrocarbons in Algiers

    Science.gov (United States)

    Kerbachi, Rabah; Boughedaoui, Ménouèr; Bounoua, Lahouari; Keddam, Malika

    The analysis of the C 6-C 16 semi-volatile organic compounds reveals the presence of numerous aromatic hydrocarbons in the ambient air of Algiers. Three representative sites were chosen for sample collection at roadside, urban background and semi-rural areas. The following major monocyclic aromatic hydrocarbons were found: benzene, toluene, ethylbenzene, ( m, p)- and o-xylene, also referred to as BTEX. Near the road traffic, benzene and toluene mean concentrations were 27 and 39 μg m -3, respectively, with benzene concentration values higher than 40 μg m -3 often observed. At the urban site, the benzene concentration often exceeds the European regulatory limit of 10 μg m -3 while the compositional ratios of toluene to benzene and ( m- p) xylene to ethylbenzene are within the typical range of values observed in urban atmospheres worldwide. The seasonal variation indicates a decrease in concentration during summer of the reactive o-xylene compound. It is suggested that Algiers' source of high-level air pollution by aromatic hydrocarbons is related to car traffic emissions.

  5. Synergetic inhibition of thermochemical formation of chlorinated aromatics by sulfur and nitrogen derived from thiourea: Multielement characterizations.

    Science.gov (United States)

    Fujimori, Takashi; Nakamura, Madoka; Takaoka, Masaki; Shiota, Kenji; Kitajima, Yoshinori

    2016-07-01

    Nitrogen and sulfur (N/S)-containing compounds inhibit the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in thermal processes. However, few studies have examined the inhibition mechanisms of N/S-containing compounds. In the present study, we focused on thiourea [(NH2)2CS] as such a compound and investigated its inhibition effects and mechanisms. The production of PCDD/Fs, polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs) were inhibited by >99% in the model fly ash in the presence of 1.0% thiourea after heating at 300 °C. Experimental results using real fly ash series were indicative of the thermal destruction of these chlorinated aromatics by thiourea. Multielement characterization using K-edge X-ray absorption fine structures of copper, chlorine, sulfur, nitrogen, and carbon revealed three possible inhibition paths, namely, (a) sulfidization of the copper catalyst to CuS, Cu2S, and CuSO4; (b) blocking the chlorination of carbon via the reaction of chlorine with N-containing compounds to generate ammonium chloride and other minor compounds; and (c) changing the carbon frame involved in attacking the carbon matrix by sulfur and nitrogen. Thus, thiourea plays a role as a sulfur and nitrogen donor to achieve multiple and synergistic inhibition of chlorinated aromatics. Our results suggest that other N/S-containing inhibitors function based on similar mechanisms.

  6. Efficient oxidative dechlorination and aromatic ring cleavage of chlorinated phenols catalyzed by iron sulfophthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Sorokin, A.; Meunier, B. [Laboratoire de Chimie de Coordination du CNRS, Toulouse (France); Seris, J.L. [Elf-Aquitaine, Artix (France)

    1995-05-26

    An efficient method has been developed for the catalytic oxidation of pollutants that are not easily degraded. The products of the hydrogen peroxide (H{sub 2}O{sub 2}) oxidation of 2,4,6-trichlorophenol (TCP) catalyzed by the iron complex 2,9,16,23-tetrasulfophthalocyanine (FePcS) were observed to be chloromaleic, chlorofumaric, maleic, and fumaric acids from dechlorination and aromatic cycle cleavage, as well as additional products that resulted from oxidative coupling. Quantitative analysis of the TCP oxidation reaction revealed that up to two chloride ions were released per TCP molecule. This chemical system, consisting of an environmentally safe oxidant (H{sub 2}O{sub 2}) and an easily accessible catalyst (FePcS), can perform several key steps in the oxidative mineralization of TCP, a paradigm of recalcitrant pollutants. 20 refs., 4 figs., 2 tabs.

  7. Rush-hour aromatic and chlorinated hydrocarbons in selected subway stations of Shanghai, China

    Institute of Scientific and Technical Information of China (English)

    Yanli Zhang; Chunlei Li; Xinming Wang; Hai Guo; Yanli Feng; Jianmin Chen

    2012-01-01

    Air samples were collected simultaneously at platform,mezzanine and outdoor in five typical stations of subway system in Shanghai,China using stainless steel canisters and analyzed by gas chromatography-mass selective detector (GC-MSD) after cryogenic preconcentration.Benzene,toluene,ethylbenzene and xylenes (BTEX) at the platforms and mezzanines inside the stations averaged (10.3± 2.1),(38.7 ± 9.0),(19.4 ± 10.1) and (30.0 ± 11.1) μg/m3,respectively; while trichloroethylene (TrCE),tetrachloroethylene (TeCE)and para-dichlorobenzene (pDCB),vinyl chloride and carbon tetrachloride were the most abundant chlorinated hydrocarbons inside the stations with average levels of (3.6 ± 1.3),(1.3 ± 0.5),(4.1 ± 1.1),(2.2 ± 1.1) and (1.2 ± 0.3) μg/m3,respectively.Mean levels of major aromatic and chlorinated hydrocarbons were higher indoor (platforms and mezzanines) than outdoor with average indoor/outdoor (I/O)ratios of 1.1-9.5,whereas no significant indoor/outdoor differences were found except for benzene and TrCE.The highly significant mutual correlations (p < 0.01) for BTEX between indoor and outdoor and their significant correlation (p < 0.05) with methyl tert-butyl ether (MTBE),a marker of traffic-related emission without other indoor and outdoor sources,indicated that BTEX were introduced into the subway stations from indoor/outdoor air exchange and traffic emission should be their dominant source.TrCE and pDCB were mainly from indoor emission and TeCE might have both indoor emission sources and contribution from outdoor air,especially in the mezzanines.

  8. In situ microbial metabolism of aromatic-hydrocarbon environmental pollutants.

    Science.gov (United States)

    Jeon, Che Ok; Madsen, Eugene L

    2013-06-01

    Microbial processes that eliminate organic environmental contamination are important. Progress in the biotechnology of biodegradation relies upon the underlying sciences of environmental microbiology and analytical geochemistry. Recent key discoveries advancing knowledge of biodegradation (in general) and the aromatic-hydrocarbon biodegradation (in particular) have relied upon characterization of microorganisms: pure-culture isolates, laboratory enrichment cultures, and in contaminated field sites. New analytical and molecular tools (ranging from sequencing the DNA of biodegrading microorganisms to assessing changes in the isotopic ratios of 13C to 12C and 2H to 1H in contaminant pools in field sites) have deepened our insights into the mechanisms (how), the occurrence (what), and the identity (who) of active players that effect biodegradation of organic environmental pollutants.

  9. Chlorine

    Science.gov (United States)

    ... but it is also used to make pesticides (insect killers), rubber, and solvents. Chlorine is used in ... the following signs and symptoms may develop: Blurred vision Burning pain, redness, and blisters on the skin ...

  10. Simulating stable carbon and chlorine isotope ratios in dissolved chlorinated groundwater pollutants with BIOCHLOR-ISO

    Science.gov (United States)

    Höhener, Patrick

    2016-12-01

    BIOCHLOR is a well-known simple tool for evaluating the transport of dissolved chlorinated solvents in groundwater, ideal for rapid screening and teaching. This work extends the BIOCHLOR model for the calculation of stable isotope ratios of carbon and chlorine isotopes in chloroethenes. An exact solution for the three-dimensional reactive transport of a chain of degrading compounds including sorption is provided in a spreadsheet and applied for modeling the transport of individual isotopes 12C, 13C, 35Cl, 37Cl from a constant source. The model can consider secondary isotope effects that can occur in the breaking of Csbnd Cl bonds. The model is correctly reproducing results for δ13C and δ37Cl modeled by a previously published 1-D numerical model without secondary isotope effects, and is also reproducing results from a microcosm experiment with secondary chlorine isotope effects. Two applications of the model using field data from literature are further given and discussed. The new BIOCHLOR-ISO model is distributed as a spreadsheet (MS EXCEL) along with this publication.

  11. Suppression of chlorinated aromatics by nitrogen and sulphur inhibitors in iron ore sintering.

    Science.gov (United States)

    Zhang, Yadi; Buekens, Alfons; Liu, Lina; Zhang, Yibo; Zeng, Xiaolan; Sun, Yifei

    2016-07-01

    Dioxins generated by iron and steel industry account for the majority of industrial dioxins emissions. This study compares the performance of different additives (including calcium sulphate dehydrate CaSO4·2H2O; calcium polysulphide CaSx; ammonium sulphate (NH4)2SO4; 4-methylthiosemicarbazide H3C-SC(NH)2NH2 and thiourea H2NCSNH2) as suppressant of chlorinated aromatics in iron ore sintering. The formation of chlorobenzenes (CBz) and polychlorinated biphenyls (PCBs), used as surrogates for dioxins, was suppressed significantly in the present of various inhibitors (1 wt%) except for CaSO4·2H2O. Moreover, a larger molar ratio of (S + N)/Cl leads to a higher suppression efficiency, so that the inhibition capacity of (NH4)2SO4 on both CBz and PCBs was weaker than H2NCSNH2. The generation of dioxin-like PCBs (Co- or dl-PCB) was also analysed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Chlorine

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, Sylvia Smith [ORNL

    2009-01-01

    Following a brief description of the use of chlorine as a chemical warfare agent in World War I, this chapter summarizes physical and chemical data and recent clinical and controlled laboratory studies on the irritant and lethal effects of chlorine. The mechanism of toxicity for both irritation and lethal effects is described. The mathematical relationship between concentration and exposure duration for a set endpoint is given for both an irritancy response and mortality. This information can be used to assist in time-scaling for the set endpoint to other exposure durations. Risk assessment addresses the potential for greater effects in sensitive populations such as asthmatics. A concentration of 0.5 ppm for up to 8 hours is a no-adverse-effect concentration in most sensitive subjects; whereas, a concentration of 1.0 ppm induces some sensory irritation and transient changes in respiratory tract airflow parameters. Treatment and intervention of exposed individuals is dependent upon symptoms

  14. Persistent organic pollutants and polycyclic aromatic hydrocarbons in penguins of the genus Pygoscelis in Admiralty Bay - An Antarctic specially managed area.

    Science.gov (United States)

    Montone, Rosalinda C; Taniguchi, Satie; Colabuono, Fernanda I; Martins, César C; Cipro, Caio Vinícius Z; Barroso, Hileia S; da Silva, Josilene; Bícego, Márcia C; Weber, Rolf R

    2016-05-15

    Persistent organic pollutants were assessed in fat samples of the Gentoo (Pygoscelis papua), Chinstrap (Pygoscelis antarcticus) and Adélie (Pygoscelis adeliae) penguins collected during the austral summers of 2005/06 and 2006/07 in Admiralty Bay, King George Island, Antarctica. The predominant organic pollutants were PCB (114 to 1115), polycyclic aromatic hydrocarbons (PAHs) (60.1 to 238.7), HCB (organic pollutants were similar among the three species of penguins. Chicks of all three species showed similar profiles of PCB congeners, with predominance of lower chlorinated compounds. The distribution of PAHs was similar in all birds, with a predominance of naphthalene and alkyl-naphthalene, which are the main constituents of arctic diesel fuel. These data contribute to the monitoring of the continued exposure to organic pollutants in the Antarctic biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Enhanced utilization of oxidants for in situ chemical oxidation of chlorinated and aromatic hydrocarbons

    Science.gov (United States)

    Kang, Namgoo

    Potentially viable strategies were sought for enhanced utilization of potassium permanganate (KMnO4) and Fenton's reagent during in situ chemical oxidation (ISCO). An innovative concept of controlled release of oxidant was introduced and organic-coated, completely or partially microencapsulated KMnO4 (MEPP) particles (874 +/- 377 mum) were created to serve a material that can be specifically targeted to a contaminant source zone. Paraffin wax was employed as the coating material because it is biodegradable, inert to KMnO4, insoluble in water and yet soluble in hydrophobic contaminants such as perchloroethylene (PCE). KMnO4 was released very slowly into water, but the oxidant was rapidly released into PCE. The estimated times for 90% release of the oxidant were 1.6 months, 19.3 years, and 472 years for paraffin wax to KMnO4 mass ratios of 1:1, 2:1 and 5:1, respectively. The MEPP particles preferentially accumulated at the PCE-water interface, and the KMnO4 was rapidly released into PCE (contaminant and the locally high concentrations of KMnO 4 could be achieved at the interfacial region between PCE and water. Fenton's oxidative destruction was investigated for aromatic hydrocarbons (benzene, toluene, ethylbenzene, and o-xylene; BTEX) present as dissolved and adsorbed phases, and chlorinated hydrocarbon (PCE) present mostly as dense non-aqueous phase liquid (DNAPL) (>93% of total PCE mass) in batch reactors (soil: solution = 1 g/L). An enhanced mass removal was observed by combining 300 mM H2O2, 2 mM Fe(III) and 2 mM N-(2-hydroxyethyl)iminodiacetic acid (HEIDA) at near-neutral pH. The PCE degradation was maximal at 600 mM H2O2, 5 mM Fe(III) and 5 mM HEIDA at pH 3. The observed BTEX mass removal rate constants (3.6--7.8 x 10-4 s-1) were compared to the estimated ones (4.1--10.1 x 10-3 s-1) using a semi-quantitative kinetic model. The model sensitivity analyses indicate that iron oxides and soil organic matter could play important roles in the non-specific losses of

  16. Unintentional production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes.

    Science.gov (United States)

    Li, Sumei; Liu, Guorui; Zheng, Minghui; Liu, Wenbin; Li, Jinhui; Wang, Mei; Li, Changliang; Chen, Yuan

    2017-06-05

    Iron ore sintering (SNT) processes are major sources of unintentionally produced chlorinated persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). However, few studies of emissions of brominated POPs, such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), during SNT have been performed. Stack gas and fly ash samples from six typical SNT plants in China were collected and analyzed to determine the concentrations and profiles of PCDD/Fs, PCBs, PCNs, PBDD/Fs, and PBDEs, as well as any correlations among these compounds. The PCDD/F, PCB, PCN, PBDD/F, and PBDE emission factors were 2.47, 0.61, 552, 0.32, and 107μgt(-1), respectively (109, 4.07, 10.4, 4.41 and 0.02ng toxic equivalents t(-1), respectively). PCBs were the most abundant compounds by mass, while PCNs were the next most abundant, contributing 51% and 42% to the total POP concentration, respectively. However, PCDD/Fs were the dominant contributors to the chlorinated and brominated POP toxic equivalent concentrations, contributing 89% to the total toxic equivalent concentration. The PCDD/F and other chlorinated and brominated POP concentrations were positively correlated, indicating that chlorinated and brominated POP emissions could be synergistically decreased using the best available technologies/best environmental practices already developed for PCDD/Fs. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Molecular comparison of cultivable protozoa from a pristine and a polycyclic aromatic hydrocarbon polluted site

    DEFF Research Database (Denmark)

    Lara, E; Berney, C; Ekelund, Flemming

    2007-01-01

    We compared the abundance and diversity of cultivable protozoa (flagellates and amoebae) in a polycyclic aromatic hydrocarbon (PAH) polluted soil and an unpolluted control, by isolating and cultivating clonal strains. The number of cultivable protozoa was higher in the polluted soil; however...

  18. From organic pollutants to bioplastics: insights into the bioremediation of aromatic compounds by Cupriavidus necator.

    Science.gov (United States)

    Berezina, Nathalie; Yada, Bopha; Lefebvre, Rodrigue

    2015-01-25

    Organic pollution by aromatic compounds is of increasing concern to our environment. Therefore, the transformation of aromatic pollutants into valuable aliphatic and biodegradable bioplastics was studied. Since benzoic acid was found to be the key compound for such bioremediation processes, its transformation, and metabolic pathways of digestion, by Cupriavidus necator were specifically analysed. It was found that the degradation of aromatic compounds follows the 2,3-dioxygenase pathway in this strain and that the batch transformations of benzoic acid with either fresh or adapted cells were limited to an initial concentration of 2.5 g/L of pollutant. The repeated fed-batch with partial withdrawal process, however, showed a 17.5-fold improvement, thus allowing the transformation of a total of 43.7 g/L in 12 weeks.

  19. Influence of Cu, Fe, Pb, and Zn chlorides and oxides on formation of chlorinated aromatic compounds in MSWI fly ash.

    Science.gov (United States)

    Fujimori, Takashi; Takaoka, Masaki; Takeda, Nobuo

    2009-11-01

    Model fly ashes containing admixed Cu, Fe, Pb, and Zn chlorides and oxides were heated at a temperature corresponding to the postcombustion zone of a municipal solid waste incinerator (MSWI), resulting in the formation of chlorinated aromatic compounds, including polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs), polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs). The concentrations of these compounds were measured and compared with those occurring in real fly ash. The order with respect generative capacity of each metal additive was calculated from principal component analysis of the concentrations of the different chlorinated aromatic compounds as CuCl(2)*2H(2)O > Cu(2)(OH)(3)Cl > FeCl(3)*6H(2)O > FeCl(2)*4H(2)O > CuO > Fe(2)O(3) > PbCl(2) > blank (no metal added) > ZnCl(2) > PbO > ZnO. From hierarchical cluster analysis of the concentrations and congener distribution patterns of the PCDDs, PCDFs, PCBs, and CBzs, the metallic compounds were divided into five groups: Group A (CuCl(2)*2H(2)O and Cu(2)(OH)(3)Cl), B (FeCl(3)*6H(2)O and FeCl(2)*4H(2)O), C (CuO and PbCl(2)), D (Fe(2)O(3), blank, and ZnCl(2)), and E (PbO and ZnO). Cluster analysis showed the congener distribution patterns of model fly ashes to be similar to the pattern of real MSWI fly ash. The formation of PCDDs was influenced mainly by group B, blank, and PbO; PCDFs, mainly by CuO, Fe(2)O(3) and ZnCl(2); PCBs, mainly by groups B and C; and CBzs, mainly by groups A and B. Thus, the multiple promotion of chlorinated aromatic compound formation by metallic chlorides and oxides in the fly ashes of MSWIs and other thermal processes has considerable importance for the environment.

  20. Reaction of bromine and chlorine with phenolic compounds and natural organic matter extracts--Electrophilic aromatic substitution and oxidation.

    Science.gov (United States)

    Criquet, Justine; Rodriguez, Eva M; Allard, Sebastien; Wellauer, Sven; Salhi, Elisabeth; Joll, Cynthia A; von Gunten, Urs

    2015-11-15

    Phenolic compounds are known structural moieties of natural organic matter (NOM), and their reactivity is a key parameter for understanding the reactivity of NOM and the disinfection by-product formation during oxidative water treatment. In this study, species-specific and/or apparent second order rate constants and mechanisms for the reactions of bromine and chlorine have been determined for various phenolic compounds (phenol, resorcinol, catechol, hydroquinone, phloroglucinol, bisphenol A, p-hydroxybenzoic acid, gallic acid, hesperetin and tannic acid) and flavone. The reactivity of bromine with phenolic compounds is very high, with apparent second order rate constants at pH 7 in the range of 10(4) to 10(7) M(-1) s(-1). The highest value was recorded for the reaction between HOBr and the fully deprotonated resorcinol (k = 2.1 × 10(9) M(-1) s(-1)). The reactivity of phenolic compounds is enhanced by the activating character of the phenolic substituents, e.g. further hydroxyl groups. With the data set from this study, the ratio between the species-specific rate constants for the reactions of chlorine versus bromine with phenolic compounds was confirmed to be about 3000. Phenolic compounds react with bromine or chlorine either by oxidation (electron transfer, ET) or electrophilic aromatic substitution (EAS) processes. The dominant process mainly depends on the relative position of the hydroxyl substituents and the possibility of quinone formation. While phenol, p-hydroxybenzoic acid and bisphenol A undergo EAS, hydroquinone, catechol, gallic acid and tannic acid, with hydroxyl substituents in ortho or para positions, react with bromine by ET leading to quantitative formation of the corresponding quinones. Some compounds (e.g. phloroglucinol) show both partial oxidation and partial electrophilic aromatic substitution and the ratio observed for the pathways depends on the pH. For the reaction of six NOM extracts with bromine, electrophilic aromatic substitution

  1. Intrinsic and enhanced bioremediation in aquifers contaminated with chlorinated and aromatic hydrocarbons in The Netherlands

    NARCIS (Netherlands)

    Rijnaarts, H.H.M.; Aalst-van Leeuwen, M.A. van; Heiningen, E. van; Buyzen, H. van; Sinke, A.; Liere, H.C. van; Harkes, M.; Baartmans, R.; Bosma, T.N.P.; Doddema, H.J.

    1998-01-01

    The feasibility of intrinsic and enhanced bioremediation approaches for 16 contaminated sites in the Netherlands are discussed. At at least five out of 10 chlorinated solvent sites, natural attenuation can be used as one of the tools to prevent further dispersion of the plume. At two sites stimulati

  2. 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.

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

    DEFF Research Database (Denmark)

    Nielsen, T.; Ejsing Jørgensen, Hans; Larsen, J.C.

    1996-01-01

    The presence of polycyclic aromatic hydrocarbons (PAH), mutagens and other air pollutants was investigated in a busy street in central Copenhagen and in a park area adjacent to the street. The winter concentration of benzo(a)pyrene was 4.4+/-1.2 ng/m(3) in the street air and 1.4+/-0.6 ng/m(3...

  4. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil

    DEFF Research Database (Denmark)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J

    2006-01-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63...... for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.......) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several...

  5. In Situ and Laboratory Studies on the Fate of Specific Organic Compounds in an Anerobic Landfill Leachate Plume, 2. Fate of Aromatic and Chlorinated Aliphatic Compounds

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Bjarnadóttir, Helga; Winter, Pia L.

    1995-01-01

    and laboratory batch microcosm experiments performed focusing on redox conditions, microbiology and the fate of 7 phenolic compounds. In this paper we present the results on the fate of 8 aromatic compounds and 4 chlorinated aliphatic compounds. Nitrobenzene was transformed at all distances from the landfill...... the landfill in Fe(IIl)-reducing conditions but not in NO3-reducing conditions at 350 m from the landfill. Abiotic processes apparently contributed to the transformation of tetrachloromethane. A local variation in the transformation of the chlorinated aliphatic hydrocarbons was observed at 2 m from...

  6. Evaluation of the Pollution of surface waters in the basin of west Algeria by Organo chlorine and Organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Hadjel, M.; Berkok, N.

    2009-07-01

    The pollutants are pesticides which cover a whole range of chemicals designed to protect plants from pests and destroy unwanted plants. There are a very large number of pesticides and we do here that some of the major families (organo chlorine insecticides, organophosphates, carbamates, pyrethroids, phenylcyclohexyl, herbicides. (Author)

  7. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated pesticides in background air in central Europe - investigating parameters affecting wet scavenging of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Shahpoury, P.; Lammel, G.; Holubová Šmejkalová, A.; Klánová, J.; Přibylová, P.; Váňa, M.

    2015-02-01

    Concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and chlorinated pesticides (CPs) were measured in air and precipitation at a background site in central Europe. ∑ PAH concentrations in air and rainwater ranged from 0.7 to 327.9 ng m-3 and below limit of quantification (< LOQ) to 2.1 × 103 ng L-1. The concentrations of PCBs and CPs in rainwater were < LOQ. ∑ PCB and ∑ CP concentrations in air ranged from < LOQ to 44.6 and < LOQ to 351.7 pg m-3, respectively. The potential relationships between PAH wet scavenging and particulate matter and rainwater properties were investigated. The concentrations of ionic species in particulate matter and rainwater were significantly correlated, highlighting the importance of particle scavenging process. Overall, higher scavenging efficiencies were found for relatively less volatile PAHs, underlining the effect of analyte gas-particle partitioning on scavenging process. The particulate matter removal by rain, and consequently PAH wet scavenging, was more effective when the concentrations of ionic species were high. In addition, the elemental and organic carbon contents of the particulate matter were found to influence the PAH scavenging.

  8. 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

  9. The enhanced dissolution of some chlorinated hydrocarbons and monocyclic aromatic hydrocarbons in rainwater collected in Yokohama, Japan

    Science.gov (United States)

    Okochi, Hiroshi; Sugimoto, Daisuke; Igawa, Manabu

    By simultaneous sequential sampling of gas and rainwater from 1999 to 2000 in the campus of Kanagawa University in Yokohama, Japan, we investigated the wet-scavenging process of volatile organic compounds, some chlorinated hydrocarbons (CHs) and monocyclic aromatic hydrocarbons (MAHs), via rain droplets. Their volume-weighted mean concentrations in 125 rainwater were 4.98 nM for dichloromethane, 3.71 nM for toluene, 2.00 nM for benzene, 0.93 nM for 1,2-dichloroethane, 0.62 nM for o-xylene, 0.57 nM for m, p-xylene, 0.51 nM for p-dichlorobenzene, and 0.35 nM for trichloromethylene. Their rainwater concentrations did not depend on the rainfall intensity, and the temporal variation of their concentrations was similar to that of gas-phase concentrations. The dissolution of CHs and MAHs into rainwater, however, was larger than expected from their gas-phase concentrations at the ground and their temperature-corrected Henry's law constants. A simple below-cloud scavenging model, which was developed by Levine and Schwartz (Atmos. Environ. 16 (1982) 1725) could explain the independence of the rainfall intensity but not explain their enhanced dissolution in rainwater. The results of this study indicate the estimated concentrations, which were based on the Henry's law equilibrium, considerably underestimate the wet-deposition fluxes of CHs and MAHs onto the ground.

  10. In situ sensing of subsurface contamination--part I: near-infrared spectral characterization of alkanes, aromatics, and chlorinated hydrocarbons.

    Science.gov (United States)

    Klavarioti, Maria; Kostarelos, Konstantinos; Pourjabbar, Anahita; Ghandehari, Masoud

    2014-05-01

    There is an imperative need for a chemical sensor capable of remote, in situ, long-term monitoring of chemical species at sites containing toxic chemical spills, specifically at chemical waste dumps, landfills, and locations with underground storage tanks. In the current research, a series of experiments were conducted measuring the near-infrared optical absorption of alkanes, aromatics, and chlorinated hydrocarbons. A spectral library was then developed to characterize the optical spectra of liquid hydrocarbons. Near-infrared analysis was chosen due to compatibility with optical fibers. The goal was to differentiate between classes of hydrocarbons and to also discriminate between compounds within a class of similar molecular structures. It was observed that unique absorption spectra can be obtained for each hydrocarbon, and this uniqueness can be used to discriminate between hydrocarbons from different families. Statistical analyses, namely, principal component analysis (PCA) and correlation coefficient (Spearman and Pearson methods), were attempted to match absorption spectra from an unknown hydrocarbon with the database with limited success. An algorithm was subsequently written to identify the characteristic peaks of each hydrocarbon that could be used to match data from an unknown chemical species with the database.

  11. Biological risk and pollution history of polycyclic aromatic hydrocarbons (PAHs) in Nansha mangrove, South China.

    Science.gov (United States)

    Wu, Qihang; Leung, Jonathan Y S; Tam, Nora F Y; Chen, Shejun; Mai, Bixian; Zhou, Xizhen; Xia, Lihua; Geng, Xinhua

    2014-08-15

    Chinese government has taken various measures to alleviate pollution caused by polycyclic aromatic hydrocarbons (PAHs) in the region of Pearl River Delta since the economic reform in 1978, but the effectiveness of these measures remains largely unknown. This study aimed to elucidate the biological risk and pollution history of PAHs by measuring the concentrations of 28 PAHs in the surface and core sediments, respectively, in Nansha mangrove. Results found that the biological risk of PAHs was low without obvious spatial variation. The PAH concentration along the depth gradient indicated that PAH pollution was stabilized since the early 1990s while the source of PAHs has gradually changed from combustion of coal to petroleum products. This implied that the mitigation measures taken by the Chinese government were effective. Compared to marine bottom sediment, we propose that using mangrove sediment can provide a more accurate and precise estimate of pollution history of PAHs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach.

    Science.gov (United States)

    Zheng, Yi; Lin, Zhongrong; Li, Hao; Ge, Yan; Zhang, Wei; Ye, Youbin; Wang, Xuejun

    2014-05-15

    Urban stormwater runoff delivers a significant amount of polycyclic aromatic hydrocarbons (PAHs), mostly of atmospheric origin, to receiving water bodies. The PAH pollution of urban stormwater runoff poses serious risk to aquatic life and human health, but has been overlooked by environmental modeling and management. This study proposed a dynamic modeling approach for assessing the PAH pollution and its associated environmental risk. A variable time-step model was developed to simulate the continuous cycles of pollutant buildup and washoff. To reflect the complex interaction among different environmental media (i.e. atmosphere, dust and stormwater), the dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. Long-term simulations of the model can be efficiently performed, and probabilistic features of the pollution level and its risk can be easily determined. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. The results showed that Beijing's PAH pollution of road runoff is relatively severe, and its associated risk exhibits notable seasonal variation. The current sweeping practice is effective in mitigating the pollution, but the effectiveness is both weather-dependent and compound-dependent. The proposed modeling approach can help identify critical timing and major pollutants for monitoring, assessing and controlling efforts to be focused on. The approach is extendable to other urban areas, as well as to other contaminants with similar fate and transport as PAHs.

  13. Application of nanoporous silicas as adsorbents for chlorinated aromatic compounds. A comparative study.

    Science.gov (United States)

    Moritz, Michał; Geszke-Moritz, Małgorzata

    2014-08-01

    The removal of two selected environmental pollutants such as 2,4-dichlorophenoxyacetic acid (2,4-D) and Triclosan (TC) was examined by adsorption experiments on the modified SBA-15 and MCF mesoporous silicas. Mesoporous adsorbents were modified by a grafting process with (3-aminopropyl)triethoxysilane (APTES) and 1-[3-(trimethoxysilyl)propyl]urea (TMSPU). Mesoporous materials were synthesized and characterized by N2 adsorption-desorption experiment, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and adsorption studies. The results show that both APTES-functionalized SBA-15 and MCF nanoporous carriers are potentially good adsorbents for the removal of 2,4-D in a wide range of concentrations from 0.1 to 4 mg/cm(3). Maximum adsorption capacity of as-modified adsorbents for 2,4-D estimated from the Langmuir model was ~280 mg/g. The ionic interaction between the adsorbent and 2,4-D seems to play a key role in the adsorption process of the pollutant on APTES-modified siliceous matrices. The efficiency of TC sorption onto all prepared mesoporous adsorbents was significantly lower as compared to the entrapment of 2,4-D. Experimental data were best fitted by the Langmuir isotherm model. The results of this study suggest that mesoporous silica-based materials are promising adsorbents for the removal of selected organic pollutants.

  14. Application of nanoporous silicas as adsorbents for chlorinated aromatic compounds. A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Moritz, Michał, E-mail: michal.moritz@put.poznan.pl [Poznan University of Technology, Faculty of Chemical Technology, Institute of Chemistry and Technical Electrochemistry, Piotrowo 3, 60-965 Poznań (Poland); Adam Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznań (Poland); Geszke-Moritz, Małgorzata, E-mail: Malgorzata.Geszke-Moritz@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2014-08-01

    The removal of two selected environmental pollutants such as 2,4-dichlorophenoxyacetic acid (2,4-D) and Triclosan (TC) was examined by adsorption experiments on the modified SBA-15 and MCF mesoporous silicas. Mesoporous adsorbents were modified by a grafting process with (3-aminopropyl)triethoxysilane (APTES) and 1-[3-(trimethoxysilyl)propyl]urea (TMSPU). Mesoporous materials were synthesized and characterized by N{sub 2} adsorption–desorption experiment, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and adsorption studies. The results show that both APTES-functionalized SBA-15 and MCF nanoporous carriers are potentially good adsorbents for the removal of 2,4-D in a wide range of concentrations from 0.1 to 4 mg/cm{sup 3}. Maximum adsorption capacity of as-modified adsorbents for 2,4-D estimated from the Langmuir model was ∼ 280 mg/g. The ionic interaction between the adsorbent and 2,4-D seems to play a key role in the adsorption process of the pollutant on APTES-modified siliceous matrices. The efficiency of TC sorption onto all prepared mesoporous adsorbents was significantly lower as compared to the entrapment of 2,4-D. Experimental data were best fitted by the Langmuir isotherm model. The results of this study suggest that mesoporous silica-based materials are promising adsorbents for the removal of selected organic pollutants. - Graphical abstract: Adsorption of 2,4-dichlorophenoxyacetic acid and Triclosan inside 3-amino-functionalized mesoporous channel.

  15. 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)

  16. Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Bacteria Isolated from Light Oil Polluted Soils

    Science.gov (United States)

    Ohnuma, T.; Suto, K.; Inoue, C.

    2007-03-01

    Polycyclic aromatic hydrocarbons (PAHs) have polluted soil and groundwater widely and for long term because of their low solubility at normal temperature. Several microorganisms, such as Pseudomonas sp., Sphigomonas sp., a white-rot fungus and so on, being able to decompose PAHs, have been isolated and researched. This study reported to investigate biodegradation of low molecule PAH by isolated bacteria from light oil polluted soil. 12 isolates were obtained from a light oil polluted soil using naphthalene, fluorene and anthracene as sole carbon source, of which 4 isolates grew with naphthalene, 4 isolates did with fluorene and 4 isolates did with anthracene. Among them 3 isolates showed the ability to degrade phenanthrene additionally. These phenanthrene degradation and growth rates were almost same as that of S. yanoikuyae (DSM6900), which is the typical bacteria of PAHs degrader. Therefore, the isolate seemed to have an expectation for PAHs degradation.

  17. Chlorinated pollutants in blood of White stork nestlings (Ciconia ciconia) in different colonies in Spain.

    Science.gov (United States)

    de la Casa-Resino, Irene; Hernández-Moreno, David; Castellano, Antonio; Pérez-López, Marcos; Soler, Francisco

    2015-01-01

    The aim of this study was to investigate the levels of persistent chlorinated pollutants (POPs) in wild birds. The concentrations of multiple POPs, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in plasma of White stork nestlings. Blood samples were collected from three breeding colonies located in the West of Spain that were exposed to different environmental conditions and human activities. The concentrations of PCBs were below the limit of detection in all samples. The OCPs Heptaclor, 4,4′-DDE, endosulfan and aldrin were detected most frequently in plasma from White stork nestlings. From these four compounds, 4,4′-DDE and Heptaclor were found in high abundance. OCPs could not be detected in the colony breading nearby a landfill and an intensive agricultural area, indicating that these banned compounds are not taken up by crops growing in this area. However, birds from the colony breading next to a landfill exhibited the highest OCPs levels. These high levels might be due to exposure of the mothers to OCPs during their migration to Africa and subsequent transfer to their eggs.

  18. Coexistence of Cu, Fe, Pb, and Zn oxides and chlorides as a determinant of chlorinated aromatics generation in municipal solid waste incinerator fly ash.

    Science.gov (United States)

    Fujimori, Takashi; Tanino, Yuta; Takaoka, Masaki

    2014-01-01

    We investigated chemical determinants of the generation of chlorinated aromatic compounds (aromatic-Cls), such as polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs), in fly ash from municipal solid waste incineration. The influences of the following on aromatic-Cls formation in model fly ash (MFA) were systematically examined quantitatively and statistically: (i) inorganic chlorides (KCl, NaCl, CaCl2), (ii) base materials (SiO2, Al2O3, CaCO3), (iii) metal oxides (CuO, Fe2O3, PbO, ZnO), (iv) metal chlorides (CuCl2, FeCl3, PbCl2, ZnCl2), and (v) "coexisting multi-models." On the basis of aromatic-Cls concentrations, the ∑CBzs/∑PCBs ratio, and the similarity between distribution patterns, MFAs were categorized into six groups. The results and analysis indicated that the formation of aromatic-Cls depended strongly on the "coexistence condition", namely multimodels composed of not only metal chlorides, but also of metal oxides. The precise replication of metal chloride to oxide ratios, such as the precise ratios of Cu-, Fe-, Pb-, and Zn-chlorides and oxides, may be an essential factor in changing the thermochemical formation patterns of aromatic-Cls. Although CuCl2 acted as a promoter of aromatic-Cls generation, statistical analyses implied that FeCl3 also largely influenced the generation of aromatic-Cls under mixture conditions. Various additional components of fly ash were also comprehensively analyzed.

  19. CORAL: QSPR modeling of rate constants of reactions between organic aromatic pollutants and hydroxyl radical.

    Science.gov (United States)

    Toropov, A A; Toropova, A P; Rasulev, B F; Benfenati, E; Gini, G; Leszczynska, D; Leszczynski, J

    2012-09-05

    The rate constants (K(OH)) of reactions between 78 organic aromatic pollutants and hydroxyl radical were examined. Simplified molecular input line entry system was used as representation of the molecular structure of the pollutants. Quantitative structure-property relationships was developed using CORAL software (http://www.insilico.eu/CORAL) for four random splits of the data into the subtraining, calibration, and test sets. The obtained results reveal good predictive potential of the applied approach: correlation coefficients (r(2)) for the test sets of the four random splits are 0.75, 0.91, 0.84, and 0.80. Using the Monte Carlo method CORAL software generated the optimal descriptors for one-variable models. The reproducibility of each model was tested performing three runs of the Monte Carlo optimization. The current data were compared to previous results and discussed. Copyright © 2012 Wiley Periodicals, Inc.

  20. 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)newspapernewspapernewspaper newspapernewspaper

  1. Recalcitrance of polycyclic aromatic hydrocarbons in soil contributes to background pollution

    Energy Technology Data Exchange (ETDEWEB)

    Posada-Baquero, Rosa [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain); Ortega-Calvo, Jose-Julio, E-mail: jjortega@irnase.csic.es [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain)

    2011-12-15

    The microbial accessibility of native phenanthrene and pyrene was determined in soils representing background scenarios for pollution by polycyclic aromatic hydrocarbons (PAHs). The soils were selected to cover a wide range of concentrations of organic matter (1.7-10.0%) and total PAHs (85-952 {mu}g/kg). The experiments included radiorespirometry determinations of biodegradation with {sup 14}C-labeled phenanthrene and pyrene and chemical analyses to determine the residual concentrations of the native compounds. Part of the tests relied on the spontaneous biodegradation of the chemicals by native microorganisms; another part also involved inoculation with PAH-degrading bacteria. The results showed the recalcitrance of PAHs already present in the soils. Even after extensive mineralization of the added {sup 14}C-PAHs, the concentrations of native phenanthrene and pyrene did not significantly decrease. We suggest that aging processes operating at background concentrations may contribute to recalcitrance and, therefore, to ubiquitous pollution by PAHs in soils. - Highlights: > Background PAHs in soils are highly resistant to biodegradation. > Recalcitrance occurs even after inoculation with specialized microorganisms. > Recalcitrance is caused by a low bioaccessibility and aging. > Time (aging) seems a relevant factor causing recalcitrance. > Recalcitrance can explain ubiquitous PAH background pollution. - Background soil PAHs are highly resistant to biodegradation.

  2. Distribution of chlorinated organic pollutants in harbor sediments of Livorno (Italy): a multivariate approach to evaluate dredging sediments.

    Science.gov (United States)

    Cicero, A M; Mecozzi, M; Morlino, R; Pellegrini, D; Veschetti, E

    2001-10-01

    Dredging is a very important procedure for harbor management. In Italy the guidelines for the offshore dumping of dredged materials are issued by the Ministry of Environment. They described a few steps of dredging activities, such as the sampling strategy, but do not deal with limits or guide-values for the chemical, physical and biological composition of the resulting sediments. The quality of dredged materials is mainly dependent on the presence of inorganic and organic pollutants. In particular, polychlorinated biphenyls (PCBs) and organo-chlorinated pesticides are seen as a high priority in marine environment by international organizations because of their persistence, toxicity and bioaccumulation capacity. In this article the presence of some PCBs and organo-chlorinated pesticides in sediment samples collected from the harbor of Livorno (Northern Tyrrhenian Sea) was investigated. The concentration of HCHs, Aldrin, Chlordanes, DDEs, DDTs, and PCBs in 12 representative sites ranged between <1 microg kg(-1) and 95, 19, 32, 35, 107, and 111 microg kg(-1), respectively. The application of univariate and multivariate statistical techniques, such as linear regression analysis and principal component analysis, to the experimental data showed a different distribution of PCBs in the two sediment layers. On the contrary, the vertical distribution of the other investigated pollutants was more homogeneous and affected by random variability. The multivariate approach was an important tool to establish more rational criteria for the management of dredged materials.

  3. Use of antioxidant enzymes of clam Ruditapes philippinarum as biomarker to polycyclic aromatic hydrocarbon pollution

    Science.gov (United States)

    Zhu, Lin; Tang, Xuexi; Wang, Ying; Sui, Yadong; Xiao, Hui

    2016-03-01

    The typical organic pollutant polycyclic aromatic hydrocarbon (PAH) anthracene was selected as a contaminant to investigate its effects on the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the clam Ruditapes philippinarum. The results show that SOD, CAT and GSH-Px had diff erent induction and inhibition reactions to anthracene stress, and that three diff erent organs in R. philippinarum (visceral mass, muscle tissue and mantle) had diff erent sensitivities to anthracene stress. This study suggest that SOD activities of the visceral mass, CAT activitities of the mantle and the visceral mass, and GSH-Px activity of the muscle tissue could be used as sensitive indicators of anthracene stress in R. philippinarum.

  4. Comparison of polycyclic aromatic hydrocarbon pollution in Chinese and Japanese residential air

    Institute of Scientific and Technical Information of China (English)

    Hao Lu; Takashi Amagai; Takeshi Ohura

    2011-01-01

    Comparative studies on polycyclic aromatic hydrocarbon (PAH) pollution in residential air of Hangzhou (China) and Shizuoka (Japan) were conducted in summer (August,2006) and winter (January,2007).Total concentrations of 8 PAHs ranged from 7.1 to 320ng/m3 and 0.15 to 35 ng/m3 in residential air of Hangzhou and Shizuoka,respectively.Air PAH concentrations in smoking houses were higher than that in nonsmoking houses.In nonsmoking houses,mothball emission and cooking practice were the emission sources of 2- and 3-ring PAHs in Hangzhou,respectively.The 2- and 3-ring PAHs were from use of insect repellent,kerosene heating and outdoor environment in nonsmoking houses in Shizuoka.The 5- and 6-ring PAHs in residential air were mainly from outdoor environment in both cities.Toxicity potencies of PAHs in residential air of Hangzhou were much higher than that in Shizuoka.

  5. Titania Nanotubes Grown on Carbon Fibers for Photocatalytic Decomposition of Gas-Phase Aromatic Pollutants

    Directory of Open Access Journals (Sweden)

    Wan-Kuen Jo

    2014-03-01

    Full Text Available This study aimed to prepare titania (TiO2 nanotube (TNT arrays grown on un-activated carbon fibers (UCFs, with the application of different TiO2 loadings based on the coating-hydrothermal process, and to evaluate their photocatalytic activity for the degradation of sub-ppm levels of aromatic pollutants (benzene, toluene, ethyl benzene, and o-xylene (BTEX using a plug-flow photocatalytic reactor. The characteristics of the prepared photocatalysts were determined by scanning electron microscopy (SEM, energy-dispersive X-ray (EDX, transmission electron microscopy (TEM, UV-visible absorption spectroscopy (UV-Vis and X-ray diffraction (XRD analyses. Spectral analysis showed that the prepared photocatalysts were closely associated with the characteristics of one-dimensional nanostructured TiO2 nanotubes for TNTUCFs and spherical shapes for TiO2-coated UCF (TUCF. The photocatalytic activities of BTEX obtained from TNTUCFs were higher than those obtained from a reference photocatalyst, TUCF. Specifically, the average degradation efficiencies of BTEX observed for TNTUCF-10 were 81%, 97%, 99%, and 99%, respectively, while those observed for TUCF were 14%, 42%, 52%, and 79%, respectively. Moreover, the photocatalytic activities obtained for TNTUCFs suggested that the degradation efficiencies of BTEX varied with changes in TiO2 loadings, allowing for the optimization of TiO2 loading. Another important finding was that input concentrations and air flow rates could be important parameters for the treatment of BTEX, which should be considered for the optimization of TNTUCFs application. Taken together, TNTUCFs can be applied to effectively degrade sub-ppm levels of gas-phase aromatic pollutants through the optimization of operational conditions.

  6. Biodegradation, bioaccessibility, and genotoxicity of diffuse polycyclic aromatic hydrocarbon (PAH) pollution at a motorway site.

    Science.gov (United States)

    Johnsen, Anders R; De Lipthay, Julia R; Reichenberg, Fredrik; Sørensen, Søren J; Andersen, Ole; Christensen, Peter; Binderup, Mona-lise; Jacobsen, Carsten S

    2006-05-15

    Diffuse pollution of surface soil with polycyclic aromatic hydrocarbons (PAHs) is problematic in terms of the large areas and volumes of polluted soil. The levels and effects of diffuse PAH pollution at a motorway site were investigated. Surface soil was sampled with increasing distance from the asphalt pavement and tested for total amounts of PAHs, amounts of bioaccessible PAHs, total bacterial populations, PAH degrader populations, the potential for mineralization of 14C-PAHs, and mutagenicity. Elevated PAH concentrations were found in the samples taken 1-8 m from the pavement. Soil sampled at greater distances (12-24 m) contained only background levels of PAHs. The total bacterial populations (CFU and numbers of 16S rDNA genes) were similar for all soil samples, whereas the microbial degrader populations (culturable PAH degraders and numbers of PAH dioxygenase genes) were most abundant in the most polluted samples close to the pavement. Hydroxypropyl-beta-cyclodextrin extraction of soil PAHs, as a direct estimate of the bioaccessibility, indicated that only 1-5% of the PAHs were accessible to soil bacteria. This low bioaccessibility is suggested to be due to sorption to traffic soot particles. The increased PAH level close to the pavement was reflected in slightly increased mutagenic activity (1 m, 0.32 +/- 0.08 revertants g(-1) soil; background/ 24 m: 0.08 +/- 0.04), determined by the Salmonella/ microsome assay of total extractable PAHs activated by liver enzymes. The potential for lighter molecular weight PAH degradation in combination with low bioaccessibility of heavier PAHs is proposed to lead to a likely increase in concentration of heavier PAHs over time. These residues are, however, likely to be of low biological significance.

  7. Dissipation of polycyclic aromatic hydrocarbons in mixed polluted soils; Dissipation des hydrocarbures aromatiques polycycliques dans les sols a pollution multiple

    Energy Technology Data Exchange (ETDEWEB)

    Saison, C.

    2001-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are toxic organic compounds that are harmful for the environment and to human health. PAHs are the major pollutants in soils of former coking plants. Dissipation decreases their concentration in soils and is a preliminary condition for remediation. In this thesis, the effect of metals on the mineralization, availability and transport in water of two labeled PAHs, {sup 14}C-benzo(a)pyrene and {sup 14}C-phenanthrene, were studied under controlled conditions (microcosms and micro-lysimeter). The natural attenuation of PAHs in planted or regularly tilled soil was also examined under natural climatic conditions. Results demonstrated that the degradation and transfer of benzo(a)pyrene, in the aqueous phase, was low and, as a result, the molecule was persistent in soil. Only 8% of phenanthrene was degraded in 110 days and, after 18 months, 15% of the residues had been leached from the soils. Bio-available metals severely inhibited the mineralization of phenanthrene, but the metabolites remained in an extractable form. Soluble organic matter was found to bind PAHs in solution and ease their transport in circulating water. Metals decreased this association and lysimeter studies confirmed the low leachability of these molecules. It was concluded that PAHs have a long residence time in these soils and that tillage practices or plants have a negligible effect on the dissipation of PAHs over this time scale. Nonetheless, plants can decrease their toxicity in soils. (author)

  8. Diversity of ndo genes in mangrove sediments exposed to different sources of polycyclic aromatic hydrocarbon pollution.

    Science.gov (United States)

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

    2007-11-01

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

  9. Electrochemical oxidation of the polycyclic aromatic hydrocarbons in polluted concrete of the residential buildings.

    Science.gov (United States)

    Aćimović, Danka D; Karić, Slavko D; Nikolić, Željka M; Brdarić, Tanja P; Tasić, Gvozden S; Marčeta Kaninski, Milica P; Nikolić, Vladimir M

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAH) have been listed by the United States Environmental Protection Agency (US EPA) and by the European Community as priority environmental pollutants. The removal of PAHs from soils, sediments and waste water has attracted attention of scientists and engineers for several decades. Electrochemical oxidation of PAH compounds in water, is receiving increasing attention, due to its convenience and simplicity. In this study we performed electrochemical oxidation of 16 EPA PAHs mixture in 10% NaCl aqueous solution in potentiostatic conditions, at voltage 1 V. Decrease of concentration of some individual PAHs, up to 70% referred to their starting concentration, after 60 min of electrolysis, was confirmed by UPLC/PDA analysis. In further work investigation was extrapolated to in situ removal of PAHs from concrete, as the medium where, to our knowledge, such way of PAH removal has not been investigated before. High concentrations of PAH contamination occurred in the concrete structure of the residential buildings in Belgrade in 2014. Application of DC voltage of 50 V between nickel and stainless steel electrodes packed in the concrete wall, moisturized with the 10% NaCl solution, led to considerable removal of the pollutants by oxidation process throughout the concrete. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. The chemokine CXCL13 in lung cancers associated with environmental polycyclic aromatic hydrocarbons pollution.

    Science.gov (United States)

    Wang, Gui-Zhen; Cheng, Xin; Zhou, Bo; Wen, Zhe-Sheng; Huang, Yun-Chao; Chen, Hao-Bin; Li, Gao-Feng; Huang, Zhi-Liang; Zhou, Yong-Chun; Feng, Lin; Wei, Ming-Ming; Qu, Li-Wei; Cao, Yi; Zhou, Guang-Biao

    2015-11-13

    More than 90% of lung cancers are caused by cigarette smoke and air pollution, with polycyclic aromatic hydrocarbons (PAHs) as key carcinogens. In Xuanwei City of Yunnan Province, the lung cancer incidence is among the highest in China, attributed to smoky coal combustion-generated PAH pollution. Here, we screened for abnormal inflammatory factors in non-small cell lung cancers (NSCLCs) from Xuanwei and control regions (CR) where smoky coal was not used, and found that a chemokine CXCL13 was overexpressed in 63/70 (90%) of Xuanwei NSCLCs and 44/71 (62%) of smoker and 27/60 (45%) of non-smoker CR patients. CXCL13 overexpression was associated with the region Xuanwei and cigarette smoke. The key carcinogen benzo(a)pyrene (BaP) induced CXCL13 production in lung epithelial cells and in mice prior to development of detectable lung cancer. Deficiency in Cxcl13 or its receptor, Cxcr5, significantly attenuated BaP-induced lung cancer in mice, demonstrating CXCL13's critical role in PAH-induced lung carcinogenesis.

  11. Polycyclic aromatic hydrocarbons pollution effect on soil biological activity in the anthropogenic contaminated area

    Science.gov (United States)

    Batukaev, Abdulmalik; Sushkova, Svetlana; Minkina, Tatiana; Antonenko, Elena; Salamova, Anzhelika; Gimp, Alina; Deryabkina, Irina

    2017-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are one of the most significant environmental contaminants with mutagenic and carcinogenic properties to all living organisms. The changes in microbial community structure in technogenic polluted soil may be used as tools for predicting and monitoring natural degradation and for search the most effective and appropriate pathways of bioremediation. The present study is aimed to research the biological activity of the soil in the emission zone of Novocherkassk Power station (NPs) (Russia) polluted by PAHs in 2015. The NPs is one of the largest thermal power stations in the south of Russia burning low-quality coal appurtenant the enterprises of I hazardous class. Monitoring plots were located on virgin or no-till fallow areas and not subject to the sanitary-protection zone of the NPs. Soil samples were taken from a depth of 0- to 20-cm, because the major part of PAHs are accumulated in the surface soil layer. The soils of the plots mainly include Chernozems Calcic (plots 1, 4, 5, 7, 9 and 10), Phaeozems Haplic (plots 3, 6, 8 and 11) Fluvisols Umbric (plots 2 and 12). In the soil of 12 monitoring plots located around NPs there were determined the main enzymes, abundance of soil bacteria and 17 priority PAHs. PAHs extraction from soil was performed by new developed ecologically clean method of subcritical water extraction without organic solvents (Sushkova et al., 2015). The level of PAHs around NPs is high at the nearest to factory monitoring plots situated at distance 1,0-1,2 km and reaches from 1600,1±14,7 up to 373,6±7,1 mkg/kg in the 20-cm soil layer. Gradually decrease of PAHs contamination is observed while increasing the distance from the NPs. The level of highmolecular PAHs (4-6 aromatic rings) exceeds the level of lowmolecular (2-3 aromatic rings) PAHs in all monitoring plots situated though the prevailing wind direction from NPs. The close correlations were found between PAHs content and biological activity parameters

  12. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil.

    Science.gov (United States)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J; Ekelund, Flemming; Christensen, Peter; Andersen, Ole; Karlson, Ulrich; Jacobsen, Carsten S

    2006-03-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several levels: by slowly diminishing PAH-concentrations, increased mineralization of 14C-PAHs, increasing numbers of PAH degraders and increased prevalence of nah and pdo1 PAH degradation genes, i.e. the microbial communities quickly adapted to PAH degradation. Three- and 4-ring PAHs from the street dust were biodegraded to some extent (10-20%), but 5- and 6-ring PAHs were not biodegraded in spite of frequent soil mixing and high PAH degradation potentials. In addition to biodegradation, leaching of 2-, 3- and 4-ring PAHs from the A-horizon to the C-horizon seems to reduce PAH-levels in surface soil. Over time, levels of 2-, 3- and 4-ring PAHs in surface soil may reach equilibrium between input and the combination of biodegradation and leaching. However, levels of the environmentally critical 5- and 6-ring PAHs will probably continue to rise. We presume that sorption to black carbon particles is responsible for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.

  13. Interaction mechanisms of Ionizable Organic Pollutants with Aromatized Biochar: Adsorption Experiments and DFT Calculations

    Science.gov (United States)

    Zhang, Kun; Chen, Baoliang

    2017-04-01

    The molecular interaction between biochars and ionizable organic pollutants (IOPs) are of great concern in natural environments, however the underlying mechanisms and their quantification under different pH range are not vivid. The adsorption of IOPs onto high temperature biochars derived from bamboo wood biomass (BW700) was conducted to quantify the various interactions between sorbent surface and IOPs under different pH conditions. The aromatized surface of BW700 were characterized by Fourier Transformed Infrared spectroscopy (FT-IR), Brunauer-Emmet-Teller (BET) specific surface area with N2 and CHN elemental compositions. Seven IOPs were selected as model sorbates, and batch sorption experiments were conducted to quantify the ratio of π-π interactions and hydrogen bonding interactions. The pH-dependent adsorption curves and the adsorption isotherms not only indicated that the adsorption capacity was related with species of IOPs, but also showed the presence of adsorbing peak owing some of the other mechanisms when taking the ice-like adlayer into consideration. Finally, density functional theory (DFT) calculations provided a possible structure of the complex combined with ice-like adlayer with aromatic substrate of BW700, and indicated that the formation of extra adsorption sites originated from the X-H ... O-H ... π interactions. The contribution of π-π interactions, hydrogen bonding interactions and X-H ... O-H ... π interactions were distinguished by the pKa value of IOPs owing to their species. Our findings provide new insight for distinction and quantification of various interactions under different pH conditions, and it is the first time to put forward the X-H ... O-H ... π interactions for the interaction mechanism of IOPs with biochar.

  14. Dehalogenation of aromatics by nucleophilic aromatic substitution.

    Science.gov (United States)

    Sadowsky, Daniel; McNeill, Kristopher; Cramer, Christopher J

    2014-09-16

    Nucleophilic aromatic substitution has been implicated as a mechanism for both the biotic and abiotic hydrodehalogenation of aromatics. Two mechanisms for the aqueous dehalogenation of aromatics involving nucleophilic aromatic substitution with hydride as a nucleophile are investigated using a validated density functional and continuum solvation protocol. For chlorinated and brominated aromatics, nucleophilic addition ortho to carbon-halogen bonds via an anionic intermediate is predicted to be the preferred mechanism in the majority of cases, while concerted substitution is predicted to be preferred for most fluorinated aromatics. Nucleophilic aromatic substitution reactions with the hydroxide and hydrosulfide anions as nucleophiles are also investigated and compared.

  15. Removal and fate of polycyclic aromatic hydrocarbon pollutants in an urban stormwater bioretention facility.

    Science.gov (United States)

    DiBlasi, Catherine J; Li, Houng; Davis, Allen P; Ghosh, Upal

    2009-01-15

    This research investigated the removal and fate of 16 USEPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) from urban stormwater runoff through a bioretention cell. Bioretention is an infiltration/filtration practice containing a mixed layer of about 90 cm of soil, sand, and organic matter, planted with appropriate vegetation. Field water quality monitoring and bioretention media core analyses were performed. The results indicate that bioretention is a promising management practice to control runoff PAH pollutants. The PAH event mean concentration (EMC) reduction ranged from 31 to 99%, with a mean discharge EMC of 0.22 microg/L. The mass load decreased from a mean value of 0.0180 kg/ha yr to 0.0025 kg/ha yr, suggesting an average PAH mass load reduction of 87% to the discharging watershed. The most dominant PAH species monitored were fluoranthene and pyrene. Influent PAHs indicated strong affiliation with runoff total suspended solids (TSS). As such, PAH removal positively correlated with TSS removal. Low rainfall depth was associated with high influent PAH concentration and resulted in favorable PAH removal. Source investigation suggested that the PAHs measured in the monitored cell were from pyrogenic sources, likely resulting from vehicle combustion processes. Sealers used in parking lots and driveway coatings were also a possible source of PAHs. Media core analyses indicated that the intercepted PAH compounds transported only a few centimeters vertically in the soil media near the runoff entrance location, suggesting that a shallow cell design may be adequate for systems focusing on PAH removal.

  16. Remediation of Groundwater Polluted by Aromatic Compounds by Means of Adsorption

    Directory of Open Access Journals (Sweden)

    Silvana Canzano

    2014-07-01

    Full Text Available In this work, an experimental and modeling analysis of the adsorption of four aromatic compounds (i.e., toluene, naphthalene, o-xylene and ethylbenzene onto a commercial activated carbon is carried out. The aim is to assess the suitability of the adsorption process for the treatment of polluted groundwater, also when a multiple contamination is detected. Batch adsorption tests from simulated polluted groundwater are performed in single-compound systems and in two binary systems (i.e., toluene + naphthalene and o-xylene + ethylbenzene, at constant temperature (20 °C and pH (7. Experimental results in single-compound systems reveal that all of the analytes are significantly adsorbed on the tested activated carbon. In particular, toluene and naphthalene adsorption capacities are the highest and of similar value, while for o-xylene and ethylbenzene, the performances are lower. The adsorption of these compounds seems to be influenced by a combined effect of several parameters, such as hydrophobicity, molecule size, structure of the molecule, etc. Experimental results in binary systems show a different behavior of the two systems, which confirms their complexity and explains the interest in these complex adsorption systems. In particular, toluene and naphthalene are mutually competitive, while in the case of o-xylene + ethylbenzene, only the former undergoes competitive effects. The analysis of the entire experimental data set is integrated with a dedicated modeling analysis using the extended Langmuir model. For both single-compound and binary systems, this model provides acceptable results, in particular for low equilibrium concentrations, like those more commonly found in groundwater, and for the compounds involved in adsorptive competitive effects.

  17. Aromatic compound emissions from municipal solid waste landfill: Emission factors and their impact on air pollution

    Science.gov (United States)

    Liu, Yanjun; Lu, Wenjing; Guo, Hanwen; Ming, Zhongyuan; Wang, Chi; Xu, Sai; Liu, Yanting; Wang, Hongtao

    2016-08-01

    Aromatic compounds (ACs) are major components of volatile organic compounds emitted from municipal solid waste (MSW) landfills. The ACs emissions from the working face of a landfill in Beijing were studied from 2014 to 2015 using a modified wind tunnel system. Emission factors (EFs) of fugitive ACs emissions from the working face of the landfill were proposed according to statistical analyses to cope with their uncertainty. And their impacts on air quality were assessed for the first time. Toluene was the dominant AC with an average emission rate of 38.8 ± 43.0 μg m-2 s-1 (at a sweeping velocity of 0.26 m s-1). An increasing trend in AC emission rates was observed from 12:00 to 18:00 and then peaked at 21:00 (314.3 μg m-2 s-1). The probability density functions (PDFs) of AC emission rates could be classified into three distributions: Gaussian, log-normal, and logistic. EFs of ACs from the working face of the landfill were proposed according to the 95th percentile cumulative emission rates and the wind effects on ACs emissions. The annual ozone formation and secondary organic aerosol formation potential caused by AC emissions from landfills in Beijing were estimated to be 8.86 × 105 kg year-1 and 3.46 × 104 kg year-1, respectively. Toluene, m + p-xylene, and 1,3,5-trimethylbenzene were the most significant contributors to air pollution. Although ACs pollutions from landfills accounts for less percentage (∼0.1%) compared with other anthropogenic sources, their fugitive emissions which cannot be controlled efficiently deserve more attention and further investigation.

  18. Runoff pollution impacts of polycyclic aromatic hydrocarbons in street dusts from a stream network town.

    Science.gov (United States)

    Zhao, Hongtao; Yin, Chengqing; Chen, Meixue; Wang, Weidong

    2008-01-01

    Runoff with contaminated street dusts has an environmental risk to the aquatic environment. An assessment of the diffuse pollution of polycyclic aromatic hydrocarbons (PAHs) from a small town and their risks to the township stream network was conducted at Yangtze River delta. This assessment is based on measurements of 16 PAHs from the US EPA priority list by GC-MS in stream water during rainy and dry season, street dusts with different particle sizes, river sediments and suspended solids of urban runoff. The maximum level of PAHs in the stream water (2,323-4,948 ng L(-1)) were found during rainy season, while significantly lower PAHs concentrations (242-998 ng L(-1)) were measured during dry season. The total PAHs ranged from 1,629 to 8,986 microg kg(-1) in the street dusts. Approximately 55% of the total PAHs were associated with street dust particles of diameters less than 250 microm and these accounted for 40% of the total. The town reaches sediments were rich in PAHs and it was suggested as the sink of street dusts. The research findings suggested that size of street dusts, the topographical and hydrological features of the landscape in the stream network were the important factors influencing PAH emitted to the receiving water. The contribution of urban surface runoff could significantly influence PAHs concentration in the stream water. To reduce the pollution of street dust into the stream network, the buffer zone along the hydrological pathway is suggested and the existing street cleaning methods should also be improved.

  19. Biotransformation of Trichoderma spp. and their tolerance to aromatic amines, a major class of pollutants.

    Science.gov (United States)

    Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Dairou, Julien

    2013-08-01

    Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.

  20. Global atmospheric emissions and transport of polycyclic aromatic hydrocarbons: Evaluation of modeling and transboundary pollution

    Science.gov (United States)

    Shen, Huizhong; Tao, Shu

    2014-05-01

    Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimated country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1° × 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). MOZART-4 (The Model for Ozone and Related Chemical Tracers, version 4) was applied to simulate the global tropospheric transport of Benzo(a)pyrene, one of the high molecular weight carcinogenic PAHs, at a horizontal resolution of 1.875° (longitude) × 1.8947° (latitude). The reaction with OH radical, gas/particle partitioning, wet deposition, dry deposition, and dynamic soil/ocean-air exchange of PAHs were considered. The simulation was validated by observations at both background and non-background sites, including Alert site in Canadian High Arctic, EMEP sites in Europe, and other 254 urban/rural sites reported from literatures. Key factors effecting long-range transport of BaP were addressed, and transboundary pollution was discussed.

  1. Optimization of purification processes to remove polycyclic aromatic hydrocarbons (PAHs) in polluted raw fish oils.

    Science.gov (United States)

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

    2014-02-01

    Fish oils are one of the main sources of health promoting nutrients such as n-3 fatty acids in animal and human diet. Nevertheless, they could be an important source of persistent organic pollutants (POPs). Different strategies of decontamination processes to reduce polycyclic aromatic hydrocarbon (PAH) levels in fish oils, such as solvent extraction (ethanol) and adsorbent extraction using commercially available (activated carbon) and sustainable adsorbents (mussel shell and wood ashes), were compared. Adsorption conditions were evaluated and optimized by an experimental design and the experimental results were adjusted to response surfaces. In this way, PAH removals increased with increasing of individual PAH molecular weight and they range from 80% to 100% using activated carbon and from 10% to 100% using wood ashes. Pine wood ashes showed similar removal rates to activated carbon (87%-100%) excluding F (51%) and P (42%). No PAH removal was observed using mussel shell ashes. Ethanol extraction was also optimized and showed a good performance in the extraction of PAHs. However, it does affect their ω-3 fatty acid contents. Finally, real oil samples from different fishing areas: Spain, South America, and North Europe were selected for the decontamination experiments under experimental conditions previously optimized.

  2. Decontamination of metals and polycyclic aromatic hydrocarbons from slag-polluted soil.

    Science.gov (United States)

    Bisone, Sara; Mercier, Guy; Blais, Jean-François

    2013-01-01

    Metallurgy is an industrial activity that is one of the largest contributors to soil contamination by metals. This contamination is often associated with organic compound contamination; however, little research has been aimed at the development of simultaneous processes for decontamination as opposed to treatments to heavy metals or organic compounds alone. This paper presents an efficient process to decontaminate the soils polluted with smelting by-products rich in Cu, Zn and polycyclic aromatic hydrocarbons (PAHs). A simultaneous treatment for metals and PAHs was also tested. The process is mainly based on physical techniques, such as crushing, gravimetric separation and attrition. For the finest particle size fractions, an acid extraction with H2SO4 was used to remove metals. The PAH removal was enhanced by adding surfactant during attrition. The total metal removals varied from 49% to 73% for Cu and from 43% to 63% for Zn, whereas a removal yield of 92% was measured for total PAHs. Finally, a technical-economic evaluation was done for the two processes tested.

  3. Heavy metals and polycyclic aromatic hydrocarbons: pollution and ecological risk assessment in street dust of Tehran.

    Science.gov (United States)

    Saeedi, Mohsen; Li, Loretta Y; Salmanzadeh, Mahdiyeh

    2012-08-15

    50 street dust samples from four major streets in eastern and southern Tehran, the capital of Iran, were analyzed for metal pollution (Cu, Cr, Pb, Ni, Cd, Zn, Fe, Mn and Li). Hakanson's method was used to determine the Risk Index (RI) and ecological risks. Amongst these samples, 21 were also analyzed for polycyclic aromatic hydrocarbons (PAHs). Correlation, cluster and principal component analyses identified probable natural and anthropogenic sources of contaminants. The dust had elevated concentrations of Pb, Cd, Cu, Cr, Ni, Zn, Fe and PAHs. Enrichment factors of Cu, Pb, Cd and Zn showed that the dust is extremely enriched in these metals. Multivariate statistical analyses revealed that Cu, Pb, Zn, Fe and PAHs and, to a lesser extent, Cr and Ni have common anthropogenic sources. While Mn and Li were identified to have natural sources, Cd may have different anthropogenic origins. All samples demonstrated high ecological risk. Traffic and related activities, petrogenic and pyrogenic sources are likely to be the main anthropogenic sources of heavy metals and PAHs in Tehran dust.

  4. Chlorine-functionalized carbon dots for highly efficient photodegradation of pollutants under visible-light irradiation

    Science.gov (United States)

    Hu, Shengliang; Ding, Yanli; Chang, Qing; Yang, Jinlong; Lin, Kui

    2015-11-01

    Chlorine-functionalized carbon dots (Cl-CDs) were prepared by the substitution reaction between Cl radicals into thionyl chloride molecules and carbon dots with containing OH/COOH groups at their surface (O-CDs). The obtained Cl-CDs with a size of 2-5 nm contain 2-3% Cl atoms and emit blue light. Compared with amine-functionalzed carbon dots (N-CDs) and O-CDs, Cl-CDs exhibit much higher photocatalytic activity under visible-light irradiation. The thermally and chemically stable phthalocyanine can be even degraded quickly through Cl-CDs. This work suggests that surface engineering of carbon dots with heteroatoms can be used to enhance their photochemical properties.

  5. Biosynthesis of gold nanoparticles by Aspergillum sp. WL-Au for degradation of aromatic pollutants

    Science.gov (United States)

    Qu, Yuanyuan; Pei, Xiaofang; Shen, Wenli; Zhang, Xuwang; Wang, Jingwei; Zhang, Zhaojing; Li, Shuzhen; You, Shengnan; Ma, Fang; Zhou, Jiti

    2017-04-01

    A simple method for synthesis of gold nanoparticles (AuNPs) using Aspergillum sp. WL-Au was presented in this study. According to UV-vis spectra and transmission electron microscopy images, the shape and size of AuNPs were affected by different parameters, including buffer solution, pH, biomass and HAuCl4 concentrations. Phosphate sodium buffer was more suitable for extracellular synthesis of AuNPs, and the optimal conditions for AuNPs synthesis were pH 7.0, biomass 100 mg/mL and HAuCl4 3 mM, leading to the production of spherical and pseudo-spherical nanoparticles. The biosynthesized AuNPs possessed excellent catalytic activities for the reduction of 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, o-nitroaniline and m-nitroaniline in the presence of NaBH4, and the catalytic rate constants were calculated to be 6.3×10-3 s-1, 5.5×10-3 s-1, 10.6×10-3 s-1, 8.4×10-3 s-1 and 13.8×10-3 s-1, respectively. The AuNPs were also able to catalyze the decolorization of various azo dyes (e.g. Cationic Red X-GRL, Acid Orange II and Acid scarlet GR) using NaBH4 as the reductant, and the decolorization rates reached 91.0-96.4% within 7 min. The present study should provide a potential candidate for green synthesis of AuNPs, which could serve as efficient catalysts for aromatic pollutants degradation.

  6. The Lagrange Street story: the prevention of aromatics air pollution during the last nine years in a European city

    Energy Technology Data Exchange (ETDEWEB)

    Bono, R.; Bugliosi, E.H.; Schiliro, T.; Gilli, G. [Torino Univ. (Italy). Dept. of Public Health and Microbiology

    2001-01-01

    Benzene, toluene and xylenes (BTX) air pollution is a very important topic for environmental health, due to the toxicity and/or mutagenic or carcinogenic properties of these aromatics and the commercialisation of the unleaded gasoline containing amount of BTX. We measured BTX in the air of Turin city, the capital of Piedmont region (north-western Italy), during 10 years, from 1989 to 1998. The sampling site selected was Lagrange Street (LS), an 'urban canyon' placed in the centre of the city. The behaviour of BTX in LS was conditioned by some local and national legislative measures enforced during 1990s for the reduction of automotive traffic and BTX air pollution, respectively. Taking into account the existence of similar measures undertaken also in several cities in the developed countries, largely described but never discussed, the aim of this study was to verify in LS the preventive effects of these regulatory actions by means of a longitudinal survey extended over 10 years. Results obtained in Lagrange Street highlight seasonal trends, typical of this kind of pollutants, and an important reduction (from 42.6 to 15.9ppbv) of aromatic hydrocarbons (sum of benzene, toluene and xylenes) in atmospheric air from 1990 to 1997. In particular, the annual level of benzene in air showed a mean from 9.2ppbv in 1990 to 2.0ppbv in 1997, almost half of the 3.1ppbv imposed by law since 31 December 1998. In conclusion, the present findings induce a consistent optimism about the usefulness and the effectiveness of these types of regulatory actions enforced to reduce the human exposure to BTX, which could be extended also to other trafficated sites where the aromatics air pollution has to be reduced. (Author)

  7. Seawater Polluted with Highly Concentrated Polycyclic Aromatic Hydrocarbons Suppresses Osteoblastic Activity in the Scales of Goldfish, Carassius auratus.

    Science.gov (United States)

    Suzuki, Nobuo; Sato, Masayuki; Nassar, Hossam F; Abdel-Gawad, Fagr Kh; Bassem, Samah M; Yachiguchi, Koji; Tabuchi, Yoshiaki; Endo, Masato; Sekiguchi, Toshio; Urata, Makoto; Hattori, Atsuhiko; Mishima, Hiroyuki; Shimasaki, Youhei; Oshima, Yuji; Hong, Chun-Sang; Makino, Fumiya; Tang, Ning; Toriba, Akira; Hayakawa, Kazuichi

    2016-08-01

    We have developed an original in vitro bioassay using teleost scale, that has osteoclasts, osteoblasts, and bone matrix as each marker: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Using this scale in vitro bioassay, we examined the effects of seawater polluted with highly concentrated polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) on osteoblastic and osteoclastic activities in the present study. Polluted seawater was collected from two sites (the Alexandria site on the Mediterranean Sea and the Suez Canal site on the Red Sea). Total levels of PAHs in the seawater from the Alexandria and Suez Canal sites were 1364.59 and 992.56 ng/l, respectively. We were able to detect NPAHs in both seawater samples. Total levels of NPAHs were detected in the seawater of the Alexandria site (12.749 ng/l) and the Suez Canal site (3.914 ng/l). Each sample of polluted seawater was added to culture medium at dilution rates of 50, 100, and 500, and incubated with the goldfish scales for 6 hrs. Thereafter, ALP and TRAP activities were measured. ALP activity was significantly suppressed by both polluted seawater samples diluted at least 500 times, but TRAP activity did not change. In addition, mRNA expressions of osteoblastic markers (ALP, osteocalcin, and the receptor activator of the NF-κB ligand) decreased significantly, as did the ALP enzyme activity. In fact, ALP activity decreased on treatment with PAHs and NPAHs. We conclude that seawater polluted with highly concentrated PAHs and NPAHs influences bone metabolism in teleosts.

  8. Bioaccumulation of heavy metals, metalloids, and chlorine in ectomycorrhizae from smelter-polluted area.

    Science.gov (United States)

    Cejpková, Jaroslava; Gryndler, Milan; Hršelová, Hana; Kotrba, Pavel; Řanda, Zdeněk; Synková, Iva; Borovička, Jan

    2016-11-01

    Ectomycorrhizal (ECM) fungi contribute to the survival of host trees on metal-rich soils by reducing the transfer of toxic metals into roots. However, little is known about the ability of ECM fungi to accumulate elements in ectomycorrhizae (ECMs). Here we report Ag, As, Cd, Cl, Cu, Sb, V, and Zn contents in wild-grown Norway spruce ECMs collected in a smelter-polluted area at Lhota near Příbram, Czech Republic. The ECMs data were compared with the element concentrations determined in the corresponding non-mycorrhizal fine roots, soils, and soil extracts. Bioaccumulation factors were calculated to differentiate the element accumulation ability of ECMs inhabited by different mycobionts, which were identified by ITS rDNA sequencing. Among the target elements, the highest contents were observed for Ag, Cl, Cd, and Zn; Imleria badia ECMs showed the highest capability to accumulate these elements. ECMs of Amanita muscaria, but not of other species, accumulated V. The analysis of the proportions of I. badia and A. muscaria mycelia in ECMs by using species-specific quantitative real-time PCR revealed variable extent of the colonization of roots, with median values close to 5% (w/w). Calculated Ag, Cd, Zn and Cl concentrations in the mycelium of I. badia ECMs were 1 680, 1 510, 2 670, and 37,100 mg kg(-1) dry weight, respectively, indicating substantial element accumulation capacity of hyphae of this species in ECMs. Our data strengthen the idea of an active role of ECM fungi in soil-fungal-plant interactions in polluted environments.

  9. Urban air pollution and health risks of parent and nitrated polycyclic aromatic hydrocarbons in two megacities, southwest China

    Science.gov (United States)

    Zhuo, Shaojie; Du, Wei; Shen, Guofeng; Wang, Rui; Pan, Xuelian; Li, Tongchao; Han, Yang; Li, Yungui; Pan, Bo; Peng, Xing; Cheng, Hefa; Wang, Xilong; Shi, Guoliang; Xing, Baoshan; Tao, Shu

    2017-10-01

    Ambient air pollution in China has a significant spatial variation due to the uneven development and different energy structures. This study characterized ambient pollution of parent and nitrated polycyclic aromatic hydrocarbons (PAHs) through a 1-year measurement in two megacities in southwest China where regional PM2.5 levels were considerably lower than other regions. Though the annual average BaP levels in both two cities were below the national standard of 1.0 ng/m3, however, by taking other PAHs into account, PAHs pollution were serious as indicated by high BaP equivalent concentrations (BaPEQ) of 3.8 ± 2.6 and 4.4 ± 1.9 ng/m3, respectively. Risk assessment would be underestimated by nearly an order of magnitude if only using BaP in risk assessment compared to the estimation based on 26 PAHs including 16 priority and 10 non-priority isomers targeted in this study. Estimated incremental lifetime cancer risks (ILCR) were comparable at two cities, at about 330-380 persons per one million, even though the mass concentrations were significantly different. Nitrated PAHs showed distinct temporal and site differences compared to the parent PAHs. High cancer risks due to inhalation exposure of PAHs and their polar derivatives in the low PM2.5-pollution southwest China suggest essential and effective controls on ambient PAHs pollution in the region, and controls should take potential health risks into account instead of solely mass concentration.

  10. Effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Chlorine content and position of chlorinated phenols have many significant effects on the reactivity of oxido-reduction. The effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate were evaluated through different kinetics studies. Since chlorine was an electron withdrawing atom, the substitution of chlorine on the aromatic ring decreased the oxidation rate constant by σ-electron withdrawing conductive effect; at the same time, the substitution of chlorine at ortho or para position on the aromatic ring increased the oxidation rate constant by π-electron donating conjugative effect, and the conjugative effect could counteract the negative impact of the conductive effect to some extent. On the other hand, the substitution of chlorine at ortho position on the aromatic ring decreased the oxidation rate constant by steric hindrance effect. The oxidation rate constants of phenol and chlorinated phenols studied decreased as follow order: 4-chlorophenol>2,4-dichlorophenol>phenol>2,6-dichlorophenol.

  11. Chlorinated and parent polycyclic aromatic hydrocarbons in environmental samples from an electronic waste recycling facility and a chemical industrial complex in China.

    Science.gov (United States)

    Ma, Jing; Horii, Yuichi; Cheng, Jinping; Wang, Wenhua; Wu, Qian; Ohura, Takeshi; Kannan, Kurunthachalam

    2009-02-01

    Chlorinated polycyclic aromatic hydrocarbons (CIPAHs) are a class of halogenated contaminants found in the urban atmosphere; they have toxic potential similar to that of dioxins. Information on the sources of CIPAHs is limited. In this study, concentrations of 20 CIPAHs and 16 parent PAHs were measured in electronic wastes, workshop-floor dust, vegetation, and surface soil collected from the vicinity of an electronic waste (e-waste) recycling facility and in surface soil from a chemical industrial complex (comprising a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant), and agricultural areas in central and eastern China. High concentrations of SigmaCIPAHs were found in floor dust (mean, 103 ng/g dry wt), followed in order of decreasing concentration by leaves (87.5 ng/g drywt), electronic shredder waste (59.1 ng/g dry wt), and soil (26.8 ng/g dry wt) from an e-waste recycling facility in Taizhou. The mean concentration of SigmaCIPAHs in soil from the chemical industrial complex (88 ng/g dry wt) was approximately 3-fold higher than the concentration in soil from e-waste recycling facilities. The soils from e-waste sites and industrial areas contained mean concentrations of SigmaCIPAHs 2 to 3 orders of magnitude higher than the concentrations in agricultural soils (ND-0.76 ng/g), suggesting that e-waste recycling and chlorine-chemical industries are potential emission sources of CIPAHs. The profiles of CIPAHs in soil and dust were similar to a profile that has been reported previously for fly ash from municipal solid waste incinerators (6-CIBaP was the predominant compound), but the profiles in vegetation and electronic shredder waste were different from those found in fly ash. Concentrations of 16 parent PAHs were high (150-49,700 ng/g) in samples collected from the e-waste recycling facility. Significant correlation between SigmaCIPAH and SigmaPAH concentrations suggests that direct chlorination of parent PAHs is the major pathway of formation of

  12. Polycyclic aromatic hydrocarbon-polluted dredged peat sediments and earthworms: a mutual interference

    NARCIS (Netherlands)

    Eijsackers, H.J.P.; Jonge, de S.; Muijs, B.; Slijkerman, D.; Gestel, van C.A.M.

    2001-01-01

    In lowland areas of the Netherlands, any peat sediments will gradually become enriched with anthropogenically derived Polycyclic Aromatic Hydrocarbons. Due to Dutch policy standards these (anaerobic) sediments are not allowed to be dredged and placed onto land. Under aerobic conditions, however, bio

  13. Monitoring polycyclic aromatic hydrocarbon pollution in the marine environment after the Prestige oil spill by means of seabird blood analysis.

    Science.gov (United States)

    Pérez, Cristóbal; Velando, Alberto; Munilla, Ignacio; López-Alonso, Marta; Oro, Daniel

    2008-02-01

    In this study we tested the use of seabird blood as a bioindicator of polycyclic aromatic hydrocarbon (PAH) pollution in the marine environment. Blood cells of breeding yellow-legged gulls (Larus michahellis) were able to track spatial and temporal changes consistent with the massive oil pollution pulse that resulted from the Prestige oil spill. Thus, in 2004, blood samples from yellow-legged gulls breeding in colonies that were in the trajectory of the spill doubled in theirtotal PAH concentrations when compared to samples from unoiled colonies. Furthermore, PAH levels in gulls from an oiled colony decreased by nearly a third in two consecutive breeding seasons (2004 and 2005). Experimental evidence was gathered by means of an oil-ingestion field experiment. The total concentration of PAHs in the blood of gulls given oil supplements was 30% higher compared to controls. This strongly suggested that measures of PAHs in the blood of gulls are sensitive to the ingestion of small quantities of oil. Our study provides evidence that seabirds were exposed to residual Prestige oil 17 months after the spill commenced and gives support to the nondestructive use of seabirds as biomonitors of oil pollution in marine environments.

  14. Knitting aromatic polymers for efficient solid-phase microextraction of trace organic pollutants.

    Science.gov (United States)

    Liu, Shuqin; Hu, Qingkun; Zheng, Juan; Xie, Lijun; Wei, Songbo; Jiang, Ruifen; Zhu, Fang; Liu, Yuan; Ouyang, Gangfeng

    2016-06-10

    A series of knitting aromatic polymers (KAPs) were successfully synthesized using a simple one-step Friedel-Crafts alkylation of aromatic monomers and were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Then, as-synthesized KAPs with large surface areas, unique pore structures and high thermal stability were prepared as solid-phase microextraction (SPME) coatings that exhibited good extraction abilities for a series of benzene compounds (i.e., benzene, toluene, ethylbenzene and m-xylene, which are referred to as BTEX) and polycyclic aromatic hydrocarbons (PAHs). Under the optimized conditions, the methodologies established for the determination of BTEX and PAHs using the KAPs-triPB and KAPs-B coatings, respectively, possessed wide linear ranges, low limits of detection (LODs, 0.10-1.13ngL(-1) for BTEX and 0.05-0.49ngL(-1) for PAHs) and good reproducibility. Finally, the proposed methods were successfully applied to the determination of BTEX and PAHs in environmental water samples, and satisfactory recoveries (93.6-124.2% for BTEX and 77.2-113.3% for PAHs) were achieved. This study provides a benchmark for exploiting novel microporous organic polymers (MOPs) for SPME applications.

  15. 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.

  16. Pollution and pollution tolerance in the case of polycyclic aromatic hydrocarbons (PAH); Belastung durch Polyzyklische aromatische Kohlenwasserstoffe (PAK)

    Energy Technology Data Exchange (ETDEWEB)

    Renger, M.; Mekiffer, B. [Technische Univ. Berlin (Germany). Inst. fuer Oekologie-Bodenkunde

    1997-12-31

    The purpose of the present follow-up project was to examine the contamination with polycyclic aromatic hydrocarbons (PAH) of different anthropogenic urban soils including clay soils containing demolition waste, household waste, ash, and residues from a coking plant. A further task was to analyse, or infer from other part-projects, standard soil parameters such as organic carbon content, pH, and anion levels in order to clarify any relationships between PAH contamination and the more easily determinable soil characteristics. Furthermore, the sorption behaviour for PAH of selected anthropogenic urban soils was to be characterised by means of batch experiments. [Deutsch] Im Rahmen des Anschlussvorhabens sollte die Kontamination von anthropogenen Stadtboeden- darunter Truemmerschutt-, Hausmuell-, Asche- sowie Kokereilehmboden- durch polyzyklische aromatische Kohlenwasserstoffe (PAK) untersucht werden. Zusaetzlich sollten die bodenkundlichen Standardparameter Corg, pH-Wert, Anionengehalte und KAKpot analysiert bzw. von den anderen Teilvorhaben uebernommen werden, um Zusammenhaenge zwischen der PAK-Kontamination und relativ leicht zu bestimmenden bodenkundlichen Kennwerten klaeren zu koennen. Das Sorptionsverhalten ausgewaehlter anthropogener Stadtboeden fuer PAK sollte durch Batchversuche charakterisiert werden. (orig./SR)

  17. Pollution characteristics of polycyclic aromatic hydrocarbons (PAHs) in oily sludge from the Zhongyuan Oilfield and its peripheral soils

    Institute of Scientific and Technical Information of China (English)

    KUANG Shaoping; XU Zhong

    2009-01-01

    The purpose of this study is to determine the degree of contamination caused by polycyclic aromatic hydrocarbons (PAHs) in oily sludge and soils around it in the Zhongyuan Oilfield. The contents of polycyclic aromatic hydrocarbons in oily sludge samples were determined with HPLC. The contents of PAHs of oily sludge from three different oil production plants vary from high to low in the order of the Wenming oily sludge dumping site of No. 3 Oil Production Plant (3W)>the Mazhai oily sludge dumping site of No. 3 Oil Production Plant (3M)>the Wen'er oily sludge dumping site of No. 4 Oil Production Plant (4W). Naphthalene, acenaphthylene, acenaphthene, fluorine and phenanthrene are the major pollutants of PAHs in oily sludge. The contents of PAHs in soil samples around the oily sludge dumping sites vary widely from 434.49 to 2408.8 ng/g. Naphthalene, acenaphthene, fluorine, phenanthrene and pyrene are the characteristic factors of PAHs in soil samples of 3M and 3W, and naphthalene, acenaphthene, fluorine and phenanthrene are the characteristic factors of PAHs in soil samples of 4W. According to these data and the ratios of Fl/Py, PAHs in oily sludge samples come mainly from petrogenic sources, and soil samples are divided into petrogenic soil samples and mixed-source soil samples, and both petrogenic and pyrogenic soil samples in terms of the sources of PAHs. The classification by Nemero index P indicates that soils around the oily sludge dumping sites have been seriously polluted.

  18. Air pollution from a large steel factory: polycyclic aromatic hydrocarbon emissions from coke-oven batteries.

    Science.gov (United States)

    Liberti, Lorenzo; Notarnicola, Michele; Primerano, Roberto; Zannetti, Paolo

    2006-03-01

    A systematic investigation of solid and gaseous atmospheric emissions from some coke-oven batteries of one of Europe's largest integrated steel factory (Taranto, Italy) has been carried out. In air monitoring samples, polycyclic aromatic hydrocarbons (PAHs) were consistently detected at concentrations largely exceeding threshold limit values. By means of PAHs speciation profile and benzo(a)pyrene (BaP) equivalent dispersion modeling from diffuse sources, the study indicated that serious health risks exist not only in working areas, but also in a densely populated residential district near the factory.

  19. Pollution sources identification of polycyclic aromatic hydrocarbons of soils in Tianjin area, China

    Energy Technology Data Exchange (ETDEWEB)

    Ye, B.X.; Zhang, Z.H.; Mao, T. [University of Petroleum, Beijing (China). Faculty of Natural Resources & Information Technology

    2006-07-15

    A total of 188 surface soil samples were collected from different types of utilization soils in Tianjin area. Factor analysis and scatter point surface tension spine function interpolation were used to analyze types and spatial distributions of PAH sources of surface soils in Tianjin area. The results showed that most pollution sources were mixed sources including coal burning and petroleum spill. Mixed sources occupied 56.12%, 58.96%, 46.45% and 59.50% in farmland of wastewater irrigation, common farmland, wild land and city green-belt, respectively. Other pollution sources such as vehicle emission, biogenic conversion, wood burning and natural gas combustion were also significant. The spatial distributions of pollution sources were closely related to geographic location, geographic condition and living habit of indigenes.

  20. A Novel Method for Analyzing Chlorine Isotope Fractionation for Source and Fate Assessment of Organochlorine Soil and Groundwater Pollutants

    Science.gov (United States)

    Aeppli, Christoph; Wiegert, Charline; Holmstrand, Henry; Andersson, Per; Gustafsson, Örjan

    2010-05-01

    We developed a simple and accurate analytical method for compound-specific determination of chlorine isotopic composition (δ37Cl) or organochlorines based on GC/MS analysis and standard isotope bracketing. Good accuracy (comparison with off-line thermal ionization mass spectrometry) and a precision comparable to other on-line δ37Cl-methods (0.6 permil vs SMOC) were achieved. We applied this method to assess biodegradation of polychlorinated phenols used for wood preservation at a former sawmill site in northern Sweden. To come up with a δ37Cl-based estimation of the importance of on-going aerobic microbial degradation, we analyzed 37Cl-enrichment during enzymatic dechlorination of polychlorinated phenols in laboratory experiments. We also investigated δ37Cl fingerprints of chloroperoxidase-mediated chlorinated phenols, which can be used for apportionment of natural and anthropogenic sources of chlorophenols in boreal soils. Furthermore, we investigated natural attenuation of chlorinated ethenes in a contaminated aquifer in the Czech Republic. At this site, the extent of naturally occurring reductive tetrachloroethene (PCE) dechlorination was estimated based on PCE-δ37Cl. Overall, our laboratory and field studies demonstrate the potential of using compound-specific chlorine isotope analysis for assessing the source and fate of organochlorine groundwater and soil contaminants.

  1. Polycyclic aromatic hydrocarbon pollution in the surface water and sediments of Chabahar Bay, Oman Sea.

    Science.gov (United States)

    Agah, Homira; Mehdinia, Ali; Bastami, Kazem Darvish; Rahmanpour, Shirin

    2017-02-15

    In the present study, the concentrations and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in the water and surface sediments from the Chabahar Bay, Oman Sea, were investigated in May (premonsoon) and December (postmonsoon) 2012. The concentrations of PAHs in the surface water samples ranged from 1.7 to 2.8ngl(-1) and from 0.04 to 59.6ngl(-1) in pre- and postmonsoon, respectively. In general, the PAH levels of the water samples from Chabahar Bay were higher in postmonsoon than in premonsoon (p<0.05). The concentrations of PAHs in the sediment samples varied from undetectable levels to 92.8ngg(-1) d.w. in both seasons. The seasonal comparison of the results in sediment samples showed that the overall concentration of PAH compounds was higher in the postmonsoon season (p<0.05).

  2. Radiation degradation of aromatic pollutants exit in wastewater and ph dependence

    CERN Document Server

    Takriti, S

    2002-01-01

    The effect of gamma radiation on the degradation of phenol (hydroxybenzene), resorcinol (1,3 dihydroxybenzen) and hydroquinone (1,4 dihydroxybenzen) exit in waste water was investigated. The concentrations of these pollutants as well as the irradiated solution ph were studied. The results showed that the phenol is very resistance against the radiation doses comparing the other phenol compounds. Phenol was also a product of radiolysis of resorcinol and hydroquinone. On the other hand, the acid phase of the irradiation sample increased the degradation rate of pollutants. Spectrophotometer (UV-VIS) and chromatography (HPLC) were used to monitor the analysis of the radiation product solution. The results illustrated the existing of many substances such as organic alcohol, aldehyde, ketone and acidic functional groups as a final radiation products. The degradation of benzene, monochlorobenzene (CB) and 1,2 dichlorobenzene (1,2 DCB) exit in waste water by gamma irradiation was investigated. The effect of the irradi...

  3. The assessment of daily dietary intake reveals the existence of a different pattern of bioaccumulation of chlorinated pollutants between domestic dogs and cats.

    Science.gov (United States)

    Ruiz-Suárez, Norberto; Camacho, María; Boada, Luis D; Henríquez-Hernández, Luis A; Rial, Cristian; Valerón, Pilar F; Zumbado, Manuel; González, Maira Almeida; Luzardo, Octavio P

    2015-10-15

    Pet dogs and cats have been proposed as sentinel species to assess environmental contamination and human exposure to a variety of pollutants, including POPs. However, some authors have reported that dogs but not cats exhibit intriguingly low levels of some of the most commonly detected POPs, such as DDT and its metabolites. This research was designed to explore these differences between dogs and cats. Thus, we first determined the concentrations of 53 persistent and semi-persistent pollutants (16 polycyclic aromatic hydrocarbons (PAHs), 18 polychlorinated biphenyls (PCBs) and 19 organochlorine pesticides (OCPs)) in samples of the most consumed brands of commercial feed for dogs and cats, and we calculated the daily dietary intake of these pollutants in both species. Higher levels of pollutants were found in dog food and our results showed that the median values of intake were about twice higher in dogs than in cats for all the three groups of pollutants (ΣPAHs: 274.8 vs. 141.8; ΣOCPs: 233.1 vs. 83; ΣPCBs: 101.8 vs. 43.8 (ng/kg bw/day); respectively). Additionally, we determined the plasma levels of the same pollutants in 42 and 35 pet dogs and cats, respectively. All these animals lived indoors and were fed on the commercial brands of feed analyzed. As expected (considering the intake), the plasma levels of PAHs were higher in dogs than in cats. However, for organochlorines (OCPs and PCBs) the plasma levels were much higher in cats than in dogs (as much as 23 times higher for DDTs), in spite of the higher intake in dogs. This reveals a lower capacity of bioaccumulation of some pollutants in dogs, which is probably related with higher metabolizing capabilities in this species. Copyright © 2015. Published by Elsevier B.V.

  4. Severe aromatic hydrocarbon pollution in the Arctic town of Longyearbyen (Svalbard) caused by snowmobile emissions.

    Science.gov (United States)

    Reimann, Stefan; Kallenborn, Roland; Schmidbauer, Norbert

    2009-07-01

    The aromatic hydrocarbons benzene, toluene and C2-benzenes (ethyl benzene and m,p,o-xylene) (BTEX) were measured during a 2-month monitoring campaign in 2007 in the Arctic town of Longyearbyen (Spitsbergen, Svalbard). Reflecting the remoteness of the location, very low mixing ratios were observed during night and in windy conditions. In late spring (April-May), however, the high frequency of guided snowmobile tours resulted in "rush-hour" maximum values of more than 10 ppb of BTEX. These concentration levels are comparable to those in European towns and are caused predominately by the outdated 2-stroke engines, which are still used by approximately 30% of the snowmobiles in Longyearbyen. During summer, peak events were about a factor of 100 lower compared to those during the snowmobile season. Emissions in summer were mainly caused by diesel-fueled heavy duty vehicles (HDVs), permanently used for coal transport from the adjacent coal mines. The documented high BTEX mixing ratios from snowmobiles in the Arctic provide an obvious incentive to change the regulation practice to a cleaner engine technology.

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

    Science.gov (United States)

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

    2012-12-01

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

  6. Soil pollution by polycyclic aromatic hydrocarbons: A comparison of two Chinese cities

    Institute of Scientific and Technical Information of China (English)

    Jin Ma; Yongzhang Zhou

    2011-01-01

    Soil samples from Huizhou and Zhanjiang,China were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) with harmonized sampling,sample extraction and analysis quantification methods.The concentrations and sources of PAHs in soil samples of the two cities were compared.Almost all of the PAH components were detectable in 103 soil samples.The concentrations of ΣPAHs ranged from 35.40 to 534.5 μg/kg in soil samples from Huizhou,and ranged from 9.50 to 6618.00 μg/kg in samples from Zhanjiang.Evident differences of concentrations,compositions and sources of PAHs in soils were observed between the two cities.The average concentrations of individual component and the sum of a group of PAHs in soil samples from Zhanjiang were significantly higher than those in Huizhou (P < 0.05).Phe,Flu,Pyr,Bbf and Ban were the dominant PAH components both in soil samples from Huizhou and Zhanjiang.Except for these five components,Bap,Ilp,Daa and Bgp were also the dominant PAH components in soil samples from Zhanjiang.Coal combustion and liquid fossil fuel combustion were the same sources of PAHs in the two cities with different contributions,and petroleum played a key role in PAHs release in Zhanjiang.

  7. The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

    Science.gov (United States)

    Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

    2009-02-01

    Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

  8. Pattern of polycyclic aromatic hydrocarbons (PAHs) pollution in communication air of Hangzhou, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nine PAHs were surveyed in communication air of Hangzhou. The results indicated that the PAHs pollution is very serious and the total sum of 9 PAHs, on the average are 3.39- 13.82 μg/m3. The PAHs signatures for all streets are similar to each other. Multivariate statistical techniques were used to investigate source apportionment for PAHs. A factor analysis/multiple regression model was successfully applied to the study. The most important three PAHs sources in communication air are diesel emission, gasoline engine emission, coal-burning accounting for 61. 1 ± 6.4%, 19.9± 8.3%, 10.8 ± 10.8% of total PAHs, respectively. The relationship for three source tracers and total PAHsis: [PAHs] =1.471(±0.155)[Phen] + 2.538 (±2.522)[1-Mepy] +2.254 (±0.943)[Chry] + 1.022 (± 1.767).

  9. Biodegradation, bioaccessibility, and genotoxicity of diffuse polycyclic aromatic hydrocarbon (PAH) pollution at a motorway site

    DEFF Research Database (Denmark)

    Johnsen, A.R.; de Lipthay, J.R.; Reichenberg, F.

    2006-01-01

    at greater distances (12-24 m) contained only background levels of PAHs. The total bacterial populations (CFU and numbers of 16S rDNA genes) were similar for all soil samples, whereas the microbial degrader populations (culturable PAH degraders and numbers of PAH dioxygenase genes) were most abundant...... in the most polluted samples close to the pavement. Hydroxypropyl-beta-cyclodextrin extraction of soil PAHs, as a direct estimate of the bioaccessibility, indicated that only 1-5% of the PAHs were accessible to soil bacteria. This low bioaccessibility is suggested to be due to sorption to traffic soot...... particles. The increased PAH level close to the pavement was reflected in slightly increased mutagenic activity (1 m, 0.32 +/- 0.08 revertants g(-1) soil; background/24 m: 0.08 +/- 0.04), determined by the Salmonella/microsome assay of total extractable PAHs activated by liver enzymes. The potential...

  10. [Pollution characteristics and distribution of polycyclic aromatic hydrocarbons and organochlorine pesticides in groundwater at Xiaodian Sewage Irrigation Area, Taiyuan City].

    Science.gov (United States)

    Li, Jia-le; Zhang, Cai-xiang; Wang, Yan-xin; Liao, Xiao-ping; Yao, Lin-lin; Liu, Min; Xu, Liang

    2015-01-01

    Sewage irrigation has been widely used in areas of water shortage in northern China, and it may introduce organic contaminants into groundwater. To characterize the organic contaminants in groundwater in sewage irrigation area, the Xiaodian sewage irrigation area in Shanxi Province was chosen as the case study area. A total of 16 groundwater samples (13 from shallow aquifer, 3 from deep aquifer) were collected. Polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS) and organochlorine pesticides (OCPs) were ainalyzed by gas chromatography-electron capture detection (GC-ECD). The results showed that the concentrations of PAHs ranged from 13.98 to 505.89 ng x L(-1) with an average concentration of 115.67 ng x (L)(-1). The 2 and 3 ring-PAHs were the main components, while naphthalene and phenanthrene were most frequently detected. The concentrations of OCPs were in the range of 13.91-103.23 ng x L(-1) with an average concentration of 40.99 ng x L(-1), while alpha-HCH, delta-HCH, o,p'-DDD, Aldrin, Endosulfan-sulfate and HCB were most frequently detected. Overall, shallow aquifers appeared more contaminated with these pollutants than deep aquifers. In the area, the order of the organic contaminants concentration in groundwater was: East Main Channel groundwater was influenced by the sewage irrigation.

  11. Application of a Novel Semiconductor Catalyst, CT, in Degradation of Aromatic Pollutants in Wastewater: Phenol and Catechol

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2014-01-01

    Full Text Available Water-soluble phenol and phenolic compounds were generally removed via advanced oxidation processes. A novel semiconductor catalyst, CT, was the first-time employed in the present study to degrade phenol and catechol. The phenolic compounds (initial concentration of 88 mg L−1 were completely mineralized by the CT catalytic nanoparticles (1% within 15 days, under acidic condition and with the presence of mild UV radiation (15 w, the emitted wavelength is 254 nm and the light intensity <26 μw/cm2. Under the same reaction condition, 1% TiO2 (mixture of rutile and anatase, nanopowder, <100 nm and H2O2 had lower removal efficiency (phenol: <42%; catechol: <60%, whereas the control (without addition of catalysts/H2O2 only showed <12% removal. The processes of phenol/catechol removal by CT followed pseudo-zero-order kinetics. The aromatic structures absorbed the UV energy and passed to an excited state, which the CT worked on. The pollutants were adsorbed on the CT’s surface and oxidized via charge-transfer and hydroxyl radical generation by CT. Given low initial concentrations, a circumstance encountered in wastewater polishing, the current set-up should be an efficient and less energy- and chemical-consumptive treatment method.

  12. Graphene-coated materials using silica particles as a framework for highly efficient removal of aromatic pollutants in water

    Science.gov (United States)

    Yang, Kaijie; Chen, Baoliang; Zhu, Lizhong

    2015-01-01

    The substantial aggregation of pristine graphene nanosheets decreases its powerful adsorption capacity and diminishes its practical applications. To overcome this shortcoming, graphene-coated materials (GCMs) were prepared by loading graphene onto silica nanoparticles (SiO2). With the support of SiO2, the stacked interlamination of graphene was held open to expose the powerful adsorption sites in the interlayers. The adsorption of phenanthrene, a model aromatic pollutant, onto the loaded graphene nanosheets increased up to 100 fold compared with pristine graphene at the same level. The adsorption of GCMs increased with the loading amount of the graphene nanosheets and dramatically decreased with the introduction of oxygen-containing groups in the graphene nanosheets. The highly hydrophobic effect and the strong π-π stacking interactions of the exposed graphene nanosheets contributed to their superior adsorption of GCMs. An unusual GCM peak adsorption coefficient (Kd) was observed with the increase in sorbate concentration. The sorbate concentration at peak Kd shifted to lower values for the reduced graphene oxide and graphene relative to the graphene oxide. Therefore, the replacement of water nanodroplets attached to the graphene nanosheets through weak non-hydrogen bonding with phenanthrene molecules via strong π-π stacking interactions is hypothesized to be an additional adsorption mechanism for GCMs. PMID:26119007

  13. Graphene-coated materials using silica particles as a framework for highly efficient removal of aromatic pollutants in water.

    Science.gov (United States)

    Yang, Kaijie; Chen, Baoliang; Zhu, Lizhong

    2015-06-29

    The substantial aggregation of pristine graphene nanosheets decreases its powerful adsorption capacity and diminishes its practical applications. To overcome this shortcoming, graphene-coated materials (GCMs) were prepared by loading graphene onto silica nanoparticles (SiO2). With the support of SiO2, the stacked interlamination of graphene was held open to expose the powerful adsorption sites in the interlayers. The adsorption of phenanthrene, a model aromatic pollutant, onto the loaded graphene nanosheets increased up to 100 fold compared with pristine graphene at the same level. The adsorption of GCMs increased with the loading amount of the graphene nanosheets and dramatically decreased with the introduction of oxygen-containing groups in the graphene nanosheets. The highly hydrophobic effect and the strong π-π stacking interactions of the exposed graphene nanosheets contributed to their superior adsorption of GCMs. An unusual GCM peak adsorption coefficient (Kd) was observed with the increase in sorbate concentration. The sorbate concentration at peak Kd shifted to lower values for the reduced graphene oxide and graphene relative to the graphene oxide. Therefore, the replacement of water nanodroplets attached to the graphene nanosheets through weak non-hydrogen bonding with phenanthrene molecules via strong π-π stacking interactions is hypothesized to be an additional adsorption mechanism for GCMs.

  14. Development of an attached-growth process for the on-site bioremediation of an aquifer polluted by chlorinated solvents.

    Science.gov (United States)

    Frascari, Dario; Bucchi, Giacomo; Doria, Francesco; Rosato, Antonella; Tavanaie, Nasrin; Salviulo, Raffaele; Ciavarelli, Roberta; Pinelli, Davide; Fraraccio, Serena; Zanaroli, Giulio; Fava, Fabio

    2014-06-01

    A procedure for the design of an aerobic cometabolic process for the on-site degradation of chlorinated solvents in a packed bed reactor was developed using groundwater from an aquifer contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The work led to the selection of butane among five tested growth substrates, and to the development and characterization from the site's indigenous biomass of a suspended-cell consortium capable to degrade TCE (first order constant: 96 L gprotein(-1) day(-1) at 30 °C and 4.3 L gprotein(-1) day(-1) at 15 °C) with a 90 % mineralization of the organic chlorine. The consortium immobilization had strong effects on the butane and TCE degradation rates. The microbial community structure was slightly changed by a temperature shift from 30 to 15 °C, but remarkably affected by biomass adhesion. Given the higher TCE normalized degradation rate (0.59 day(-1) at 15 °C) and attached biomass concentration (0.13 gprotein Lbioreactor(-1) at 15 °C) attained, the porous ceramic carrier Biomax was selected as the best option for the packed bed reactor process. The low TeCA degradation rate exhibited by the developed consortium suggested the inclusion of a chemical pre-treatment based on the TeCA to TCE conversion via β-elimination, a very fast reaction at alkaline pH. To the best of the authors' knowledge, this represents the first attempt to develop a procedure for the development of a packed bed reactor process for the aerobic cometabolism of chlorinated solvents.

  15. The assessment of daily dietary intake reveals the existence of a different pattern of bioaccumulation of chlorinated pollutants between domestic dogs and cats

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Suárez, Norberto; Camacho, María; Boada, Luis D.; Henríquez-Hernández, Luis A.; Rial, Cristian; Valerón, Pilar F.; Zumbado, Manuel; González, Maira Almeida; Luzardo, Octavio P., E-mail: octavio.perez@ulpgc.es

    2015-10-15

    Pet dogs and cats have been proposed as sentinel species to assess environmental contamination and human exposure to a variety of pollutants, including POPs. However, some authors have reported that dogs but not cats exhibit intriguingly low levels of some of the most commonly detected POPs, such as DDT and its metabolites. This research was designed to explore these differences between dogs and cats. Thus, we first determined the concentrations of 53 persistent and semi-persistent pollutants (16 polycyclic aromatic hydrocarbons (PAHs), 18 polychlorinated biphenyls (PCBs) and 19 organochlorine pesticides (OCPs)) in samples of the most consumed brands of commercial feed for dogs and cats, and we calculated the daily dietary intake of these pollutants in both species. Higher levels of pollutants were found in dog food and our results showed that the median values of intake were about twice higher in dogs than in cats for all the three groups of pollutants (ΣPAHs: 274.8 vs. 141.8; ΣOCPs: 233.1 vs. 83; ΣPCBs: 101.8 vs. 43.8 (ng/kg bw/day); respectively). Additionally, we determined the plasma levels of the same pollutants in 42 and 35 pet dogs and cats, respectively. All these animals lived indoors and were fed on the commercial brands of feed analyzed. As expected (considering the intake), the plasma levels of PAHs were higher in dogs than in cats. However, for organochlorines (OCPs and PCBs) the plasma levels were much higher in cats than in dogs (as much as 23 times higher for DDTs), in spite of the higher intake in dogs. This reveals a lower capacity of bioaccumulation of some pollutants in dogs, which is probably related with higher metabolizing capabilities in this species. - Highlights: • First assessment of the dietary intake of POPs in pet animals. • Intake levels of pollutants are more than double in dogs than in cats. • Proportionality between intake of PAHs and their plasma levels in both species. • Lower levels of organochlorines in dog plasma

  16. Formation of disinfection byproducts upon chlorine dioxide preoxidation followed by chlorination or chloramination of natural organic matter.

    Science.gov (United States)

    Yang, Xin; Guo, Wanhong; Lee, Wontae

    2013-06-01

    Chlorine dioxide (ClO2) is often used as an oxidant to remove taste, odor and color during water treatment. Due to the concerns of the chlorite formation, chlorination or chloramination is often applied after ClO2 preoxidation. We investigated the formation of regulated and emerging disinfection byproducts (DBPs) in sequential ClO2-chlorination and ClO2-chloramination processes. To clarify the relationship between the formation of DBPs and the characteristics of natural organic matter (NOM), changes in the properties of NOM before and after ClO2 oxidation were characterized by fluorescence, Fourier transform infrared spectroscopy (FTIR), and size and resin fractionation techniques. ClO2 preoxidation destroyed the aromatic and conjugated structures of NOM and transformed large aromatic and long aliphatic chain organics to small and hydrophilic organics. Treatment with ClO2 alone did not produce significant amount of trihalomethanes (THMs) and haloacetic acids (HAAs), but produced chlorite. ClO2 preoxidation reduced THMs, HAAs, haloacetonitriles (HANs) and chloral hydrate (CH) during subsequent chlorination, but no reduction of THMs was observed during chloramination. Increasing ClO2 doses enhanced the reduction of most DBPs except halonitromethanes (HNMs) and haloketones (HKs). The presence of bromide increased the formation of total amount of DBPs and also shifted DBPs to more brominated ones. Bromine incorporation was higher in ClO2 treated samples. The results indicated that ClO2 preoxidation prior to chlorination is applicable for control of THM, HAA and HAN in both pristine and polluted waters, but chlorite formation is a concern and HNMs and HKs are not effectively controlled by ClO2 preoxidation.

  17. Vehicle fleet emissions of black carbon, polycyclic aromatic hydrocarbons, and other pollutants measured by a mobile laboratory in Mexico City

    Directory of Open Access Journals (Sweden)

    M. Jiang

    2005-01-01

    Full Text Available Black carbon (BC and polycyclic aromatic hydrocarbons (PAHs are of concern due to their effects on climate and health. The main goal of this research is to provide the first estimate of emissions of BC and particle-phase PAHs (PPAHs from motor vehicles in Mexico City. The emissions of other pollutants including carbon monoxide (CO, oxides of nitrogen (NOx, volatile organic compounds (VOCs, and particulate matter of diameter 2.5 μm and less (PM2.5 are also estimated. As a part of the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003, a mobile laboratory was driven throughout the city. The laboratory was equipped with a comprehensive suite of gas and particle analyzers, including an aethalometer that measured BC and a photoionization aerosol sensor that measured PPAHs. While driving through traffic, the mobile lab continuously sampled exhaust plumes from the vehicles around it. We have developed a method of automatically identifying exhaust plumes, which are then used as the basis for calculation of fleet-average emissions. In the approximately 75 h of on-road sampling during the field campaign, we have identified ~30 000 exhaust measurement points that represent a variety of vehicle types and driving conditions. The large sample provides a basis for estimating fleet-average emission factors and thus the emission inventory. Motor vehicles in the Mexico City area are estimated to emit 1700±200 metric tons BC, 57±6 tons PPAHs, 1 190 000±40 000 tons CO, 120 000±3000 tons NOx, 240 000±50 000 tons VOCs, and 4400±400 tons PM2.5 per year, not including cold start emissions. The estimates for CO, NOx, and PPAHs may be low by up to 10% due to the slower response time of analyzers used to measure these species. Compared to the government's official motor vehicle emission inventory for the year 2002, the estimates for CO, NOx, VOCs, and PM2.5 are 38% lower, 23% lower, 27% higher, and 25% higher, respectively. The

  18. Household air pollution and personal exposure risk of polycyclic aromatic hydrocarbons among rural residents in Shanxi, China.

    Science.gov (United States)

    Chen, Y; Shen, G; Huang, Y; Zhang, Y; Han, Y; Wang, R; Shen, H; Su, S; Lin, N; Zhu, D; Pei, L; Zheng, X; Wu, J; Wang, X; Liu, W; Wong, M; Tao, S

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants of widespread concerns. Gaseous and size-segregated particulate-phase PAHs were collected in indoor and outdoor air in rural households. Personal exposure was measured and compared to the ingestion exposure. The average concentrations of 28 parent PAHs and benzo(a)pyrene (BaP) were 9000 ± 8390 and 131 ± 236 ng/m(3) for kitchen, 2590 ± 2270 and 43 ± 95 ng/m(3) for living room, and 2800 ± 3890 and 1.6 ± 0.7 ng/m(3) for outdoor air, respectively. The mass percent of high molecular weight (HMW) compounds with 5-6 rings contributed 1.3% to total 28 parent PAHs. Relatively higher fractions of HMW PAHs were found in indoor air compared to outdoor air. Majorities of particle-bound PAHs were found in the finest PM0.25 , and the highest levels of fine PM0.25 -bound PAHs were in the kitchen using peat and wood as energy sources. The 24-h personal PAH exposure concentration was 2100 ± 1300 ng/m(3) . Considering energies, exposures to those using wood were the highest. The PAH inhalation exposure comprised up to about 30% in total PAH exposure through food ingestion and inhalation, and the population attributable fraction (PAF) for lung cancer in the region was 0.85%. The risks for inhaled and ingested intakes of PAHs were 1.0 × 10(-5) and 1.1 × 10(-5) , respectively.

  19. Pollution status of polycyclic aromatic hydrocarbons in surface sediments from the Yangtze River Estuary and its adjacent coastal zone.

    Science.gov (United States)

    Wang, Chenglong; Zou, Xinqing; Gao, Jianhua; Zhao, Yifei; Yu, Wenwen; Li, Yali; Song, Qiaochu

    2016-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by incomplete combustion and are used as indicators of anthropogenic activities on the environment. This study analyses the PAHs level in the Yangtze River Estuary (YRE), an important component of Yangtze River and a developed and populated region in China. Surface sediments were collected from 77 sites at the YRE and its adjacent coastal zone (IACZ) for a comprehensive study of PAHs. Kriging interpolation technology and Positive matrix factorization (PMF) model were applied to explore the spatial distribution and sources of PAHs. Concentrations of 16 PAHs (ΣPAHs) varied from 27.2 ng g(-1) to 621.6 ng g(-1) dry weight, with an average value of 158.2 ng g(-1). Spatially, ΣPAHs exhibited wide fluctuation and exhibited an increasing tendency from north to south. In addition, ΣPAHs exhibited a decreasing trend with increasing distance between the estuary and IACZ. The deposition flux of PAHs indicated that more than 107.8 t a(-1) PAHs was deposited in the study area annually. The results of the PMF model revealed that anthropogenic activities were the main sources of PAHs in the study area. Vehicle emissions and marine engines were the most important sources and accounted for 40.9% of the pollution. Coal combustion, petrogenic sources, and wood combustion were other sources that contributed 23.9%, 23.6%, and 11.5%, respectively. The distribution patterns of PAHs in the YRE and IACZ were influenced by many complicated factors such as sediment grain size, hydrodynamics and so on. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Assessment and source identification of pollution risk for touristic ports: Heavy metals and polycyclic aromatic hydrocarbons in sediments of 4 marinas of the Apulia region (Italy).

    Science.gov (United States)

    Mali, Matilda; Dell'Anna, Maria Michela; Mastrorilli, Piero; Damiani, Leonardo; Piccinni, Alberto Ferruccio

    2017-01-30

    The Apulia region in Italy has the longest Adriatic coastline; thus, maritime tourism is the driving force for its economic development. Pollution risk for four representative touristic ports of the region was assessed by determining the concentrations of 10 metals, 16 polycyclic aromatic hydrocarbons (PAHs) congeners, and the main nutrients. The cumulative mean Effects Range-Median quotient (mERMq) was used to assess the hazard degree, while the distribution patterns and content ratios of different PAH sediment concentrations were investigated to identify the pollution sources. Principal component analyses indicated an anomalous pollution trend for one of the small touristic ports assessed; this trend emerged from contamination by heavy metals and PAHs to a larger extent than expected, considering the main activity in this port, especially in its inner basin. The reason of this anomaly is thought to be the hydrodynamic and/or other stress factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Electrochemical dehalogenation of chlorinated aromatic hydrocarbons with nickel(II) complexes as mediators in methanol; Elektrochemische Enthalogenierung chlorierter Aromaten mittels Nickel(II)-Komplexen als Mediatoren in Methanol

    Energy Technology Data Exchange (ETDEWEB)

    Nuennecke, D.

    2000-07-01

    The dissertation investigates the electrochemical dechlorination of persistent organic chlorine compounds. An alternative to high-temperature combustion will be developed. The electrochemical dehalogenation reaction was to be made more selective with the aid of so-called mediator substances. A flow cell model was developed for continuous electrolytic cells. [German] Die vorliegende Arbeit beschaeftigt sich mit der elektrochemischen Dechlorierung von persistenten chlororganischen Verbindungen. Es soll eine Alternative zur Hochtemperatureverbrennung erarbeitet werden. Aufgabenstellung der Arbeit war die Erhoehung der Selektivitaet der elektrochemischen Enthalogenierung mithilfe von sog. Mediatoren. Fuer kontinuierlich arbeitenden Elektrolysezellen wurde ein Modell fuer eine Durchflusszelle entwickelt.(uke)

  2. Construction of a plant-microbe phytoremediation system: combination of vetiver grass with a functional endophytic bacterium, Achromobacter xylosoxidans F3B, for aromatic pollutants removal.

    Science.gov (United States)

    Ho, Ying-Ning; Hsieh, Ju-Liang; Huang, Chieh-Chen

    2013-10-01

    The endophytic bacterial strain Achromobacter xylosoxidans F3B, which was able to utilize aromatic compounds as a sole carbon source, was inoculated into vetiver grass in this study. A real-time PCR detection method has been developed for confirming the stability of F3B in plants and DGGE profiles were conducted for examining the diversity of endophytes during the remediation process. These results showed that the endophytic bacteria strain F3B could maintain a stable population in plant roots without largely interfering with the diversity of native endophytes. Furthermore, the strain F3B could protect plants against toluene stress and maintain chlorophyll content of leaves, and a 30% reduction of evapotranspiration through vetiver leaves was observed. Our results demonstrate the potential to improve phytoremediation of aromatic pollutants by inoculating functional endophytic bacterial strains. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Metabolic reconstruction of aromatic compounds degradation from the genome of the amazing pollutant-degrading bacterium Cupriavidus necator JMP134.

    Science.gov (United States)

    Pérez-Pantoja, Danilo; De la Iglesia, Rodrigo; Pieper, Dietmar H; González, Bernardo

    2008-08-01

    Cupriavidus necator JMP134 is a model for chloroaromatics biodegradation, capable of mineralizing 2,4-D, halobenzoates, chlorophenols and nitrophenols, among other aromatic compounds. We performed the metabolic reconstruction of aromatics degradation, linking the catabolic abilities predicted in silico from the complete genome sequence with the range of compounds that support growth of this bacterium. Of the 140 aromatic compounds tested, 60 serve as a sole carbon and energy source for this strain, strongly correlating with those catabolic abilities predicted from genomic data. Almost all the main ring-cleavage pathways for aromatic compounds are found in C. necator: the beta-ketoadipate pathway, with its catechol, chlorocatechol, methylcatechol and protocatechuate ortho ring-cleavage branches; the (methyl)catechol meta ring-cleavage pathway; the gentisate pathway; the homogentisate pathway; the 2,3-dihydroxyphenylpropionate pathway; the (chloro)hydroxyquinol pathway; the (amino)hydroquinone pathway; the phenylacetyl-CoA pathway; the 2-aminobenzoyl-CoA pathway; the benzoyl-CoA pathway and the 3-hydroxyanthranilate pathway. A broad spectrum of peripheral reactions channel substituted aromatics into these ring cleavage pathways. Gene redundancy seems to play a significant role in the catabolic potential of this bacterium. The literature on the biochemistry and genetics of aromatic compounds degradation is reviewed based on the genomic data. The findings on aromatic compounds biodegradation in C. necator reviewed here can easily be extrapolated to other environmentally relevant bacteria, whose genomes also possess a significant proportion of catabolic genes.

  4. Review on Short-chain Chlorinated Paraffins Pollution in Water%水体中短链氯化石蜡污染研究进展

    Institute of Scientific and Technical Information of China (English)

    周浩郎; 邢永泽; 阎冰

    2016-01-01

    Short-chain chlorinated paraffins (SCCPs),as a candidate of persistent organic pol-lutants in “Stockholm Convention”,have potential hazard to ecological environment and peo-ple health,which becomes a new hotspot in field of environmental science worldwide.The water is an important destination of SCCPs.The distribution of SCCPs in different environ-mental media and the potential threaten of SCCPs to aquatic animals were critically reviewed in this paper.Meanwhile,the research progress and trend of SCCPs were also reviewed.%短链氯化石蜡(SCCPs)拟列入“斯德哥尔摩公约”禁止使用的一类持久性有机污染物,对生态环境和人体健康具有极大的潜在危害,已成为国际环境科学领域的一个研究热点。水体是 SCCPs 重要的“汇”,本文着重综述了水生态系统中沉积物、水、生物体等不同环境介质中 SCCPs 的含量分布及对水生生物的危害,并对SCCPs 的研究重点和前景进行展望。

  5. Chlorinated, brominated, and fluorinated organic pollutants in Nile crocodile eggs from the Kruger National Park, South Africa.

    Science.gov (United States)

    Bouwman, Hindrik; Booyens, Paul; Govender, Danny; Pienaar, Danie; Polder, Anuschka

    2014-06-01

    Repeated annual episodes of Nile crocodile deaths in two isolated areas of the Kruger National Park prompted the investigation of possible organohalogen pollutant involvement. Crocodile eggs were collected close to one of the mortality sites (Gorge) as well as from a crocodile farm (CF) as reference. ∑DDT was significantly higher in Gorge (450ng/g wm) than in CF eggs (85ng/g wet mass). Percentage DDT of ∑DDT was significantly higher in CF (14 per cent) than in Gorge eggs (5 per cent). Mean ∑DDT was almost 70 times higher than mean ∑PCB in Gorge eggs. HCB, β-HCH, mirex, brominated flame retardants (BFRs), and perfluorinated compounds (PFCs) occurred at lower concentrations. We believe that the BFR and PFCs data represent the first published results for any crocodile egg. Thickening of the outer eggshell layer of Gorge eggs was significantly associated with higher concentrations of ∑DDT. Concentrations of ∑DDT and other pollutants were in the same range as eggs from elsewhere, where there were no mortalities. Concentrations of ∑DDT in eggs from healthy Australian crocodiles were of the same orders of magnitude as the current study, making it highly unlikely that the concentrations of pollutants measured in the present study would have caused or substantially contributed towards the mortalities observed. Concerns about reproduction and behaviour remain. As large predators, crocodilians are at the apex of the freshwater aquatic food web. More research is needed to guide measures to manage African freshwater systems so that it will also sustainably accommodate these large, long-lived animals.

  6. Brominated flame retardants and related chlorinated persistent organic pollutants in fish from river Elbe and its main tributary Vltava.

    Science.gov (United States)

    Hajslová, Jana; Pulkrabová, Jana; Poustka, Jan; Cajka, Tomás; Randák, Tomás

    2007-10-01

    Brominated flame retardants (BFRs) are widely used industrial chemicals, residues of which can be nowadays found in all environmental compartments. The widespread presence of BFRs in various environmental compartments and food chain is a consequence of both their broad application area and physico-chemical properties, such as resistance to degradation and high lipophilicity. Alike in the case of other halogenated persistent organic pollutants (POPs), fish can be used as a bioindicator of aquatic environment pollution. In presented study, conducted in the year 2005, altogether 80 samples representing the most abundant fresh water fish species, viz. chub (Leuciscus cephalus), bream (Abramis brama), and perch (Perca fluviatilis) collected in 11 sampling sites located at Elbe and Vltava (Moldau) rivers were examined for levels of major BFRs. Without any exception, BFRs were detected in all fish samples. BDE 47 was the dominating congener in all fish species. This fact was not surprising, since it used to be the main component in various kinds of technical mixtures. With regard to relatively high levels of BDE 47 in fish tissue, as compared to other BFRs, and considering strong correlation with the total PBDEs content, simplified laboratory examination and, consequently, increased samples throughput can be obtained when only this congener is monitored. The potential of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS), to provide more comprehensive information on the bioaccumulating chemicals occurring in fish samples, has been demonstrated in this study.

  7. Peroxisome proliferation and antioxidant enzymes in transplanted mussels of four basque estuaries with different levels of polycyclic aromatic hydrocarbon and polychlorinated biphenyl pollution.

    Science.gov (United States)

    Orbea, Amaia; Cajaraville, Miren P

    2006-06-01

    We aimed to determine the effects of changes in polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyl (PCB) bioavailability on peroxisome proliferation and antioxidant enzymes to assess their potential use as pollution biomarkers. For this, mussels (Mytilus galloprovincialis) were sampled in Txatxarramendi and transplanted to Arriluze, Muskiz, and Plentzia (northern Spain), and vice versa. Arriluze was the most heavily polluted site, followed by Plentzia, Txatxarramendi, and Muskiz. Animals transplanted from a polluted station to a cleaner station lost contaminant load in three to six weeks, and when transplanted to a more polluted station, they accumulated PAHs and PCBs accordingly. Peroxisomal acyl-A oxidase (AOX) activity was the highest in animals from Arriluze, and animals transplanted to Arriluze showed increased AOX activity, reaching the levels of native mussels. Mussels from Txatxarramendi showed the lowest peroxisomal volume density (Vvp). Among mussels from Txatxarramendi, only those transplanted to Plentzia showed increased Vvp, whereas animals from Arriluze and Muskiz transplanted to Txatxarramendi after 2 d and six weeks, respectively, had decreased Vvp. Two days after transplant, superoxide dismutase and glutathione peroxidase activities were significantly lower in mussels from Arriluze and Muskiz, respectively, than in those from Txatxarramendi and than in animals transplanted to Txatxarramendi from these stations. In conclusion, transplant experiments with mussels are useful to assess the effects of pollution. Peroxisome proliferation, measured as induction of AOX or increased Vvp, shows great potential as a biomarker of pollution to be included in pollution monitoring programs. In the present work, we have demonstrated that peroxisome proliferation is a reversible phenomenon in mussels.

  8. Analysis of the microbial gene landscape and transcriptome for aromatic pollutants and alkane degradation using a novel internally calibrated microarray system.

    Science.gov (United States)

    Vilchez-Vargas, Ramiro; Geffers, Robert; Suárez-Diez, María; Conte, Ianina; Waliczek, Agnes; Kaser, Vanessa Sabrina; Kralova, Monika; Junca, Howard; Pieper, Dietmar H

    2013-04-01

    Despite various efforts to develop tools to detect and compare the catabolic potential and activity for pollutant degradation in environmental samples, there is still a need for an open-source, curated and reliable array method. We developed a custom array system including a novel normalization strategy that can be applied to any microarray design, allowing the calculation of the reliability of signals and make cross-experimental comparisons. Array probes, which are fully available to the scientific community, were designed from knowledge-based curated databases for key aromatic catabolic gene families and key alkane degradation genes. This design assigns signals to the respective protein subfamilies, thus directly inferring function and substrate specificity. Experimental procedures were optimized using DNA of four genome sequenced biodegradation strains and reliability of signals assessed through a novel normalization procedure, where a plasmid containing four artificial targets in increased copy numbers and co-amplified with the environmental DNA served as an internal calibration curve. The array system was applied to assess the catabolic gene landscape and transcriptome of aromatic contaminated environmental samples, confirming the abundance of catabolic gene subfamilies previously detected by functional metagenomics but also revealing the presence of previously undetected catabolic groups and specifically their expression under pollutant stress.

  9. Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.

    Science.gov (United States)

    Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

    2014-07-01

    Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (ΣAH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (ΣPAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, β-hexachlorocyclohexane (β-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (ΣPCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases.

  10. pH is the primary determinant of the bacterial community structure in agricultural soils impacted by polycyclic aromatic hydrocarbon pollution

    Science.gov (United States)

    Wu, Yucheng; Zeng, Jun; Zhu, Qinghe; Zhang, Zhenfa; Lin, Xiangui

    2017-01-01

    Acidification and pollution are two major threats to agricultural ecosystems; however, microbial community responses to co-existed soil acidification and pollution remain less explored. In this study, arable soils of broad pH (4.26–8.43) and polycyclic aromatic hydrocarbon (PAH) gradients (0.18–20.68 mg kg‑1) were collected from vegetable farmlands. Bacterial community characteristics including abundance, diversity and composition were revealed by quantitative PCR and high-throughput sequencing. The bacterial 16S rRNA gene copies significantly correlated with soil carbon and nitrogen contents, suggesting the control of nutrients accessibility on bacterial abundance. The bacterial diversity was strongly related to soil pH, with higher diversity in neutral samples and lower in acidic samples. Soil pH was also identified by an ordination analysis as important factor shaping bacterial community composition. The relative abundances of some dominant phyla varied along the pH gradient, and the enrichment of a few phylotypes suggested their adaptation to low pH condition. In contrast, at the current pollution level, PAH showed marginal effects on soil bacterial community. Overall, these findings suggest pH was the primary determinant of bacterial community in these arable soils, indicative of a more substantial influence of acidification than PAH pollution on bacteria driven ecological processes.

  11. 大气颗粒物中多环芳烃污染特征及防治对策%Pollution Characteristics and Prevention and Control Measures of Polycyclic Aromatic Hydrocarbons in Atmospheric Participate Matters

    Institute of Scientific and Technical Information of China (English)

    刘树保; 邓秀芬

    2012-01-01

    介绍了大港油田大气颗粒物和多环芳烃的污染现状,并对大港油田地区大气特征构成及大气颗粒物中多环芳烃的污染特征作了初步分析,得出大港油田地区大气颗粒物中多环芳烃污染类型为燃油型,并据此提出了防治多环芳烃污染的相应对策.%This article introduces the pollution status of atmospheric participate matter and polycyclic aromatic hydrocarbons. After analyzing the atmospheric composition and pollution characteristics of the polycyclic aromatic hydrocarbons in the atmospheric matter in Dagang Oilfield, it reaches the conclusions that the polycyclic aromatic hydrocarbons in the atmospheric matter in Dagang Oilfield are fuel type. According to the pollution type of polycyclic aromatic hydrocarbons, it proposes the corresponding countermeasures to prevent and control the pollution of polycyclic aromatic hydrocarbons.

  12. Pollution

    NARCIS (Netherlands)

    Dürr, E.; Jaffe, R.; Nonini, D.M.

    2014-01-01

    This essay points to the role of pollution in understanding the social construction of hierarchies and urban space. Conceptualizations of pollution and approaches to waste management always reflect the Zeitgeist and tend to be politically charged. We argue that an ethnographic approach to pollution

  13. Pollution

    NARCIS (Netherlands)

    Dürr, E.; Jaffe, R.; Nonini, D.M.

    2014-01-01

    This essay points to the role of pollution in understanding the social construction of hierarchies and urban space. Conceptualizations of pollution and approaches to waste management always reflect the Zeitgeist and tend to be politically charged. We argue that an ethnographic approach to pollution

  14. Electrochemical reduction characteristics and the mechanism of chlorinated hydrocarbons at the copper electrode

    Institute of Scientific and Technical Information of China (English)

    XU Wenying; GAO Tingyao; ZHOU Rongfeng; MA Lumin

    2007-01-01

    The electrochemical reduction characteristies of chlorinated hyrdrocarbons were investigated by cyclic voltammetry technique.The reduction mechanism and activity of the chlorinated hydrocarbons at the copper electrode were explored.The relationship between the structure of chlorinated hydrocarbons and their reductive activity were discussed.The experimental results showed that chlorinated alkanes and a portion of chlorinated aromatic hydrocarbons could be reduced directly at the copper electrode.However,chlorinated aromatic hydrocarbons were not easy to reduce at the copper electrode.The results provided a theoretical basis for the catalyzed iron inner electrolysis method.

  15. USE OF FLUORESCENT POLYCYLIC AROMATIC HYDROCARBON PROBES IN STUDYING THE IMPACT OF COLLOIDS ON POLLUTANT TRANSPORT IN GROUNDWATER

    Science.gov (United States)

    A fluorescence-quenching method was developed to assess the hydrophobic organic pollutant binding potential of organic colloids (OC) in unaltered natural waters. This method allows (1) direct assessment of the importance of OC-enhanced pollutant transport for environmental sam- p...

  16. 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, K.; Moon, H.-B.; Yun, S.-H.; Agusa, T.; Thomas, N.J.; Tanabe, S.

    2008-01-01

    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. ?? The Royal Society of Chemistry.

  17. Phytoremediation of Polycyclic Aromatic Hydrocarbons in Soils Artificially Polluted Using Plant-Associated-Endophytic Bacteria and Dactylis glomerata as the Bioremediation Plant.

    Science.gov (United States)

    Gałązka, Ann; Gałązka, Rafał

    2015-01-01

    The reaction of soil microorganisms to the contamination of soil artificially polluted with polycyclic aromatic hydrocarbons (PAHs) was evaluated in pot experiments. The plant used in the tests was cock's foot (Dactylis glomerata). Three different soils artificially contaminated with PAHs were applied in the studies. Three selected PAHs (anthracene, phenanthrene, and pyrene) were used at the doses of 100, 500, and 1000 mg/kg d.m. of soil and diesel fuel at the doses of 100, 500, and 1000 mg/kg d.m. of soil. For evaluation of the synergistic effect of nitrogen fixing bacteria, the following strains were selected: associative Azospirillum spp. and Pseudomonas stutzerii. Additionally, in the bioremediation process, the inoculation of plants with a mixture of the bacterial strains in the amount of 1 ml suspension per 500 g of soil was used. Chamber pot-tests were carried out in controlled conditions during four weeks of plant growth period. The basic physical, microbiological and biochemical properties in contaminated soils were determined. The obtained results showed a statistically important increase in the physical properties of soils polluted with PAHs and diesel fuel compared with the control and also an important decrease in the content of PAHs and heavy metals in soils inoculated with Azospirillum spp. and P. stutzeri after cock's foot grass growth. The bioremediation processes were especially intensive in calcareous rendzina soil artificially polluted with PAHs.

  18. Polycyclic Aromatic Hydrocarbons (PAHs) and Hopanes in Plastic Resin Pellets as Markers of Oil Pollution via International Pellet Watch Monitoring.

    Science.gov (United States)

    Yeo, Bee Geok; Takada, Hideshige; Hosoda, Junki; Kondo, Atsuko; Yamashita, Rei; Saha, Mahua; Maes, Thomas

    2017-08-01

    Oil pollution in the marine environment is an unavoidable problem due to chronic input from local sources, particularly in urban areas and oil spills. Oil pollution not only causes immediate physical damages to surrounding wildlife but also some components, including higher molecular weight PAHs, can persist in the environment for many years and pose insidious threats to the ecosystem. Long-term and nontargeted monitoring of oil pollution is important. This paper examines the ability of International Pellet Watch (IPW) for initial identification and monitoring of oil pollution by analysing PAHs and hopanes in plastic pellet samples collected globally by volunteers. PAH concentrations with the sum of 28 parent and methyl PAHs vary geographically, ranging from 0.035 to 24.4 µg/g-pellet, in line with the presence or absence of local oil pollution sources, such as oil refineries or oil spill sites. This suggests that PAHs can be used to monitor petroleum pollution in IPW. A colour-coded categorization for PAH concentrations within IPW monitoring also is established to facilitate data presentation and understanding. PAH concentrations are generally higher in Western Europe, especially around the North Sea shorelines, moderate in East Asia and North America, and lower in South East Asia, Oceania, South America, and Africa. Hopane concentrations, with a smaller spatial variation (1.7-101 µg/g-pellet), showed no spatial pattern. This result and the poor correlation between hopanes and PAHs suggest that hopane concentrations alone are unsuited to identify petroleum pollution. However, hopane compositions can be used for fingerprinting sources of oil pollution. Thus, both PAHs and hopanes in IPW allow for low cost, remote monitoring of global oil pollution.

  19. 冲击氯消毒控制建筑供水管道二次污染%Effect of Shock Chlorine Disinfection on Secondary Pollution in Building Water Supply System

    Institute of Scientific and Technical Information of China (English)

    王帅; 杨艳玲; 相坤; 李星; 赵锂; 陈永

    2016-01-01

    针对建筑小区的供水管道存在的生物作用等二次污染问题,研究了冲击氯消毒技术对DOC降解和硝化作用的控制效果以及对副产物溴酸盐的影响.结果表明,冲击氯消毒可有效控制DOC降解和硝化作用,生物降解作用明显减弱,可显著降低微生物超标的风险和威胁.停止冲击氯消毒后DOC降解和硝化作用逐步恢复,在冲击氯消毒后的第52 ~ 80天,DOC降解和硝化作用基本恢复到原有水平,因此有必要进行定期冲击氯消毒.冲击消毒后,BrO;浓度总体呈现增加的趋势,但在冲击氯消毒第80天后,供水管道的生物作用限制了BrO3-的生成,因此在进行冲击氯消毒时,应考虑供水管道中相关消毒副产物的变化趋势以及可能造成的化学安全性风险.%Aimed at solving the problem of secondary pollution in building water supply system,the effects of shock chlorine disinfection on dissolved organic carbon (DOC) biodegradation and biological nitrification as well as the existing bromate were investigated.The results showed that the shock chlorine disinfection was effective in controlling the DOC biodegradation and biological nitrification in the building water supply system.Meanwhile,the shock chlorine disinfection could significantly reduce the risk of bacteriological index.However,the biodegradation of DOC and biological nitrification could be restored to the original level on the 52nd to 80th day after chlorination.Therefore,the shock chlorine disinfection was required again.After shock chlorine disinfection,BrO3-concentrations showed an increase trend,and the biodegradation restricted the production of BrO3-concentration on the 80th day.Consequently,there should be paid more attention to the tendency of disinfection by-products and the risk of chemical safety during the shock chlorine disinfection.

  20. Diagnosis of soils polluted by aromatic hydrocarbons; Diagnostic de sols pollues par des hydrocarbures aromatiques polycycliques (HAP) a l'aide de la spectrophotometrie UV

    Energy Technology Data Exchange (ETDEWEB)

    Crone, M.

    2000-01-28

    Polycyclic aromatic hydrocarbons (PAHs) were produced by many pyrolytic or combustion processes. They were found in soils, often in high concentrations. Remediation of industrial sites contaminated by PAHs requires an initial diagnosis of the pollution. In this perspective, an analytical procedure based on UV spectrophotometry was developed and validated with about 80 soil samples. Different exploitation methods of the samples UV spectra enable to develop simple and rapid characterisation tools. A PAH UV index is proposed for the estimation of global PAH concentration. A more accurate exploitation of the spectra gives an indication on the presence or the absence of some individual PAH like benzo[a]pyrene. A maturity index based on a two wavelength approach constitutes an indicator of the potential evolution of soil contamination in natural conditions. Laboratory methodology was adapted to field analyses and a test kit was designed for this purpose. The test duration is 20 minutes. (author)

  1. Pollution characteristics of volatile organic compounds, polycyclic aromatic hydrocarbons and phthalate esters emitted from plastic wastes recycling granulation plants in Xingtan Town, South China

    Science.gov (United States)

    Huang, De-Yin; Zhou, Shun-Gui; Hong, Wei; Feng, Wei-Feng; Tao, Liang

    2013-06-01

    With the aim to investigate the main pollution characteristics of exhaust gases emitted from plastic waste recycling granulation plants, mainly volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) were analyzed in Xingtan Town, the largest distribution center of plastic waste recycling in China. Both inside and outside the plants, the total concentrations of volatile monocyclic aromatic hydrocarbons (MAHs), PAHs and PAEs ranged from 2000 to 3000 μg m-3, 450 to 1200 ng m-3, and 200 to 1200 ng m-3, respectively. Their concentration levels inside the plants were higher than those outside the plants, and PAHs and PAEs were mainly distributed in the gas-phase. Notably, highly toxic benzo[a]pyrene (BaP) could be detected inside the plants, and harmful PAEs could be detected not only inside but also outside the plants, although PAEs are non-volatile. The exhaust gas composition and concentration were related to the plastic feedstock and granulation temperature.

  2. Halogenase-Inspired Oxidative Chlorination Using Flavin Photocatalysis.

    Science.gov (United States)

    Hering, Thea; Mühldorf, Bernd; Wolf, Robert; König, Burkhard

    2016-04-18

    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.

  3. A wintertime study of PM2.5-bound polycyclic aromatic hydrocarbons in Taiyuan during 2009-2013: Assessment of pollution control strategy in a typical basin region

    Science.gov (United States)

    Li, Hongyan; Guo, Lili; Cao, Runfang; Gao, Bo; Yan, Yulong; He, Qiusheng

    2016-09-01

    Taiyuan city in Shanxi province, China has been one of the top heavily polluted cities in the world for a long time with large industrial emissions and high disease burden. Many pollution control strategies have been implemented forcefully by the government in recent years in Taiyuan. To better understand the effect of the strategies and related influence factors, we studied polycyclic aromatic hydrocarbons (PAHs) in fine particulate matter (PM2.5) during heating seasons in Taiyuan from 2009 to 2013. The results showed that the concentrations of PM2.5 (70.7-477.9 μg/m3) and related total PAHs (T-PAHs, 128.7-1840.2 ng/m3) far exceeded the air quality standards issued by the Ministry of Environmental Protection of China (MEP) and were higher than those in many domestic and foreign cities in spite of the pollution control. Source apportionment by the diagnostic ratio analysis and PMF model found that coal consumption contributed the most (52.1%) to the total PM2.5-bound PAHs followed by the coking industry (27.3%) and traffic exhausts (20.6%). Significant decreases in PM2.5 and PAHs levels were found in 2013, which was probably due to the large abatement of residential coal consumption and favorable meteorological factors. Being located in the north of Taiyuan basin, the pollution in Taiyuan could be aggravated by the regional transport of coal combustion- and coking-related pollutants from other industrial development zones in the south-western basin as found by the analysis of meteorological influence and back trajectory. Although the PAHs were the lowest in 2013, the BaPeq or ILCR were the highest in that year. This should be related to the increasing vehicle numbers in Taiyuan, because vehicle exhaust tends to enrich in higher molecular weight and more toxic PAHs. Our results provided useful guidance for solving the air pollution problem for cities in a semi- or total-closed basin with coal as the major energy source such as Taiyuan.

  4. Synthetic fuel combustion: pollutant formation. Soot initiation mechanisms in burning aromatics. First quarterly report, 19 September-31 December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Rawlins, W. T.; Tanzawa, T.

    1981-01-01

    Although considerable progress has been made in recent years in understanding the phenomenology of soot formation in the combustion of hydrocarbon fuels, relatively little attention has been focused upon aromatic fuels of the types commonly found in coal liquids. In particular, the effects of gas-phase free radicals, formed during combustion, on the kinetics of formation of incipient soot particles have not been characterized. Accordingly, an experimental investigation of the detailed kinetics of incipient soot formation in the combustion and pyrolysis of aromatic fuels of the benzene, anisole, phenol, and pyrrole families has been initiated in order to determine soot formation mechanisms and rate parameters. The experiments will be performed in a shock tube over the temperature range 1300 to 2500 K, using multiple ultraviolet, visible, and infrared diagnostics to monitor the kinetic behavior of free radicals (such as OH), incipient soot particles, and combustion products. Experiments will be conducted with artificially enhanced concentrations of free radicals such as OH and O to determine their effects on the kinetics of soot and soot precursors. The experimental work will be supported and directed by a parallel analytical effort using a detailed mechanistic model of the chemical kinetics and dynamics of the reacting systems. In this report, the design and configuration of the experimental apparatus are described, the details of the kinetic model are outlined, and possible reaction pathways are discussed.

  5. Changes in indoor pollutants since the 1950s

    DEFF Research Database (Denmark)

    Weschler, Charles J.

    2009-01-01

    Over the past half-century there have been major changes in building materials and consumer products used indoors. Composite-wood, synthetic carpets. polymeric flooring, foam Cushioning, plastic items and scented cleaning agents have become ubiquitous. The same is true for mechanical and electrical...... appliances such as washer/dryers, TVs and Computers. These materials and products emit an array of chemicals including solvents. unreacted monomers, and additives. The consequent changes in emission profiles for indoor pollutants have been accompanied by modifications in building operations. Residences...... changed. Taken together, these changes have altered the kind and concentrations of chemicals that occupants are exposed to in their homes, workplaces and schools. Since the 1950s, levels of certain indoor Pollutants (e.g., formaldehyde, aromatic and chlorinated solvents, chlorinated pesticides, PCBs) have...

  6. Development of eukaryotic zoospores within polycyclic aromatic hydrocarbon (PAH)-polluted environments: a set of behaviors that are relevant for bioremediation.

    Science.gov (United States)

    Sungthong, Rungroch; van West, Pieter; Cantos, Manuel; Ortega-Calvo, Jose Julio

    2015-04-01

    In this study, we assessed the development (formation, taxis and settlement) of eukaryotic zoospores under different regimes of exposure to polycyclic aromatic hydrocarbons (PAHs), which imitated environmental scenarios of pollution and bioremediation. With this aim, we used an oomycete, Pythium aphanidermatum, as a source of zoospores and two PAH-degrading bacteria (Mycobacterium gilvum VM552 and Pseudomonas putida G7). The oomycete and both bacteria were not antagonistic, and zoospore formation was diminished only in the presence of the highest bacterial cell density (10(8)-10(10) colony-forming units mL(-1)). A negative influence of PAHs on zoospore formation and taxis was observed when PAHs were exposed in combination with organic solutions and polar solvents. Co-exposure of PAHs with non-polar solvents [hexadecane (HD) and 2,2,4,4,6,8,8-heptamethylnonane (HMN)] did not affect zoospore settlement at the interfaces of the organic solvents and water. However, zoospores settled and created mycelial networks only at HD-water interfaces. Both bacteria diminished the toxic influence of PAHs on zoospore formation and taxis, and they did not interrupt zoospore settlement. The results suggest that zoospore development could be applicable for toxicity assessment of PAHs and enhancement of their bioavailability. Microbial interactions during both swimming modes and community formation at pollutant interfaces were revealed as major factors that have potential relevance to bioremediation.

  7. Chlorination of lignin by ubiquitous fungi has a likely role in global organochlorine production

    Science.gov (United States)

    Patricia Ortiz-Bermudez; Kolby C. Hirth; Ewald Srebotnik; Kenneth E. Hammel

    2007-01-01

    Soils and decayed plant litter contain significant quantities of chlorinated aromatic polymers that have a natural but largely unknown origin. We used cupric oxide ligninolysis coupled with gas chromatography/mass spectrometry to show that Curvularia inaequalis, a widely distributed litter ascomycete, chlorinated the aromatic rings of lignin in wood that it was...

  8. [Electrochemical reduction characteristics and mechanism of chlorinated hydrocarbon at the copper electrode].

    Science.gov (United States)

    Xu, Wen-Ying; Gao, Ting-Yao; Zhou, Rong-Feng; Ma, Lu-Ming

    2005-07-01

    The electrochemical reduction characteristics of chlorinated hydrocarbons were investigated by applying cyclic voltammetry technique. The reduction mechanism and reactivity of the chlorinated hydrocarbons at the copper electrodes were explored. The relation between the reductive reactivity at the copper electrode and the structures of this kind of compounds was discussed. The experimental results show that chlorinated paraffin hydrocarbons and a portion of chlorinated aromatic hydrocarbons could be reduced directly at the copper electrode; however, chlorinated aromatic hydrocarbons aren't easy to reduced directly at the copper electrode. The results provide a theoretical basis for the catalyzed iron inner electrolysis method.

  9. Geostatistical characterization of soil pollution at industrial sites Case of polycyclic aromatic hydrocarbons at former coking plants; Caracterisation geostatistique de pollutions industrielles de sols cas des hydrocarbures aromatiques polycycliques sur d'anciens sites de cokeries

    Energy Technology Data Exchange (ETDEWEB)

    Jeannee, N.

    2001-05-15

    Estimating polycyclic aromatic hydrocarbons concentrations in soil at former industrial sites poses several practical problems on account of the properties of the contaminants and the history of site: 1)collection and preparation of samples from highly heterogeneous material, 2) high short scale variability, particularly in presence of backfill, 3) highly contrasted grades making the vario-gram inference complicated. The sampling strategy generally adopted for contaminated sites is based on the historical information. Systematic sampling recommended for geostatistical estimation is often considered to be excessive and unnecessary. Two former coking plants are used as test cases for comparing several geostatistical methods for estimating (i) in situ concentrations and (ii) the probability that they are above a pollution threshold. Several practical and methodological questions are considered: 1) the properties of various estimators of the experimental vario-gram and the validity of the results; 2) the use of soft data, such as historical information, organoleptic observations and semi-quantitative methods, with a view to improve the precision of the estimates; 3) the comparison of standard sampling strategies, taking into account vertical repartition of grades and the history of the site. Multiple analyses of the same sample give an approximation of the sampling error. Short scale sampling shows the difficulty of selecting soils in the absence of a spatial structure. Sensitivity studies are carried out to assess how densely sampled soft data can improve estimates. By using mainly existing models, this work aims at giving practical recommendations for the characterization of soil pollution. (author)

  10. Comparison of Soxhlet and Shake Extraction of Polycyclic Aromatic Hydrocarbons from Coal Tar Polluted Soils Sampled in the Field

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Holst, Helle; Christensen, Thomas Højlund

    1994-01-01

    This study compares three extraction methods for PAHs in coal tar polluted soil: 3-times repeated shaking of the soil with dichloromethane-methanol (1:1), Soxhlet extraction with dichloromethane, and Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol....... The extraction efficiencies were determined for ten selected PAHs in triplicate samples of six soils sampled at former gasworks sites. The samples covered a wide range of PAH concentrations, from 0.6 to 397 mg/kg soil. Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol...

  11. Leaching of polycyclic aromatic hydrocarbons from power plant lignite ash--influence of parameters important for environmental pollution.

    Science.gov (United States)

    Pergal, Miodrag M; Relić, Dubravka; Tešić, Zivoslav Lj; Popović, Aleksandar R

    2014-03-01

    Nikola Tesla B power plant (TENT B), located at the Sava River, in Obrenovac, 50 km west from the Serbian's capital, Belgrade, is the second largest coal-fired power plant in the country, consisting of two blocks, each of 620 MW capacity. In order to investigate the threat polycyclic aromatic hydrocarbons (PAHs) from deposited coal ash, obtained by coal combustion in this power plant, can represent for the surrounding environment, samples of coal ash were submitted to extraction with river water used for transport of coal ash to the dump, as well as with water of different ionic strength and acidity. It was found that, out of 16 EPA priority PAHs, only naphthalene, acenaphthylene, fluorene, phenantrene, fluoranthene, and pyrene were found in measurable concentrations in the different extracts. Their combined concentration was around 0.1 μg/L, so they do not, in terms of leached concentrations, represent serious danger for the surrounding environment. In all cases of established (and leached) PAH compounds, changes of ionic strength, acidity, or the presence of organic compounds in river water may to some extent influence the leached concentrations. However, under the examined conditions, similar to those present in the environment, leached concentrations were not more than 50 % greater than the concentrations leached by distilled water. Therefore, water desorption is likely the most important mechanism responsible for leaching of PAH compounds from filter coal ash.

  12. Mechanistic Studies of TiO2 Photocatalysis and Fenton Degradation of Hydrophobic Aromatic Pollutants in Water.

    Science.gov (United States)

    Gong, Yuanzheng; Yang, Chun; Ji, Hongwei; Chen, Chuncheng; Ma, Wanhong; Zhao, Jincai

    2016-12-19

    HO-adduct radicals have been investigated and confirmed as the common initial intermediates in TiO2 photocatalysis and Fenton degradations of water-insoluble aromatics. However, the evolution of HO-adduct radicals to phenols has not been completely clarified. When 4-d-toluene and p-xylene were degraded by TiO2 photocatalysis and Fenton reactions, respectively, a portion of the 4-deuterium or 4-CH3 group (18-100 %) at the attacked ipso position shifted to the adjacent position of the ring in the formed phenols (NIH shift; NIH is short for the National Institutes of Health, to honor the place where this phenomenon was first discovered). The results, combined with the observation of a key dienyl cationic intermediate by in situ attenuated total reflectance FTIR spectroscopy, indicate that, for the evolution of HO-adduct radicals, a mixed mechanism of both the carbocation intermediate pathway and O2 -capturing pathway occurs in both aqueous TiO2 photocatalysis and aqueous Fenton reactions.

  13. Polycyclic aromatic hydrocarbons and halogenated persistent organic pollutants in canned fish and seafood products: smoked versus non-smoked products.

    Science.gov (United States)

    Drabova, Lucie; Pulkrabova, Jana; Kalachova, Kamila; Tomaniova, Monika; Kocourek, Vladimir; Hajslova, Jana

    2013-01-01

    In this study, levels of several groups of environmental contaminants represented by PAHs, PCBs, organochlorine pesticides and polybrominated diphenyl ethers were determined in various types of canned smoked and non-smoked fish and seafood products (54 samples) obtained from the Czech market. PAHs were detected in all of the studied samples, and at least one of the target halogenated persistent organic pollutants was present above the LOQ in 85% of the samples. The levels of PAHs, PCBs, organochlorine pesticides (mainly DDTs) and polybrominated diphenyl ethers found in the canned products varied in the range of 1.4-116 µg kg(-1), 0.6-59.6 µg kg(-1), 0.6-82.7 µg kg(-1) and 0.1-2.1 µg kg(-1) can content, respectively. Smoked sprats were the most contaminated fish product (n = 12) in which the highest levels of both PAHs and persistent organic pollutants were found. In 67% of the samples of smoked sprats in oil, the level of benzo[a]pyrene exceeded the maximum level of 5 µg kg(-1) established for smoked fish by European Union legislation. The distribution of target analytes between oil and fish fractions was also assessed. Significantly higher levels of PAHs were measured in the oil fraction.

  14. Bioremediation of multi-polluted soil by spent mushroom (Agaricus bisporus) substrate: Polycyclic aromatic hydrocarbons degradation and Pb availability.

    Science.gov (United States)

    García-Delgado, Carlos; Yunta, Felipe; Eymar, Enrique

    2015-12-30

    This study investigates the effect of three spent Agaricus bisporus substrate (SAS) application methods on bioremediation of soil multi-polluted with Pb and PAH from close to a shooting range with respect natural attenuation (SM). The remediation treatments involve (i) use of sterilized SAS to biostimulate the inherent soil microbiota (SSAS) and two bioaugmentation possibilities (ii) its use without previous treatment to inoculate A. bisporus and inherent microbiota (SAS) or (iii) SAS sterilization and further A. bisporus re-inoculation (Abisp). The efficiency of each bioremediation microcosm was evaluated by: fungal activity, heterotrophic and PAH-degrading bacterial population, PAH removal, Pb mobility and soil eco-toxicity. Biostimulation of the native soil microbiology (SSAS) achieved similar levels of PAH biodegradation as SM and poor soil detoxification. Bioaugmented microcosms produced higher PAH removal and eco-toxicity reduction via different routes. SAS increased the PAH-degrading bacterial population, but lowered fungal activity. Abisp was a good inoculum carrier for A. bisporus exhibiting high levels of ligninolytic activity, the total and PAH-degrading bacteria population increased with incubation time. The three SAS applications produced slight Pb mobilization (bisporus re-inoculation (Abisp) proved the best application method to remove PAH, mainly BaP, and detoxify the multi-polluted soil.

  15. Pollution level, phase distribution and health risk of polycyclic aromatic hydrocarbons in indoor air at public places of Hangzhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: luhaozju@163.com; Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: zlz@zju.edu.cn; Chen Shuguang [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: chenshuguang@zju.edu.cn

    2008-04-15

    PAHs pollution survey in air of public places was conducted in Hangzhou, China. The most serious PAHs pollution was observed in indoor air of shopping centers and the slightest was in train stations. The molecular weight of chrysene (MW 228) appeared to be the dividing line for the PAHs with a larger or smaller distribution in the vapor or particulate phase. Concentrations of 15 PAHs on PM{sub 2.5} accounted for 71.3% of total particulate PAHs, and followed by PM{sub 2.5-10} fraction (17.6%) and >PM{sub 10} fraction (11.1%). In shopping centers and supermarkets, emission of 2-4 rings PAHs occurred from indoor sources, whereas 5-6 rings PAHs predominantly originated from transport of outdoor air. In temples, PAHs in indoor air mainly originated from incense burning. Health risks associated with the inhalation of PAHs were assessed, and naphthalene made the greatest contribution (62.4%) to the total health risks. - Concentrations of PAHs in the air of selected public places in Hangzhou correspond to 10{sup -3} life-time lung cancer risk.

  16. Catalysts for the abatement of chlorine aromatics VOCs, part 1: complete screening of supported transition metal oxides catalysts; Catalyseurs pour l'abattement des COVs aromatiques chlores, Partie 1: screening complet des catalyseurs a base d'oxydes de metaux de transition supportes

    Energy Technology Data Exchange (ETDEWEB)

    Bertinchamps, F.; Gregoire, C.; Gaigneaux, E.M. [Universite Catholique de Louvain (UCL), Unite de catalyse et chimie des materiaux divises, Louvain-la-Neuve (Belgium)

    2004-07-01

    The aim of this work is to find the best catalyst for the oxidation of chlorine aromatics VOCs. 10 transition metals oxides (VO{sub x}, CrO{sub x}, MnO{sub x}, ZrO{sub x}, NbO{sub x}, MoO{sub x}, SnO{sub x}, TaO{sub x}, WO{sub x}, BiO{sub x}) impregnated on 4 supports (Al{sub 2}O{sub 3}, SiO{sub 2}, TiO{sub 2} and sulfated TiO{sub 2}) have been tested for the deep oxidation of benzene. This step has revealed the very good activity of the VO{sub x}, CrO{sub x} and MnO{sub x} catalysts and the favourable effect of the use of the TiO{sub 2} support. The active phases have been identified by XRD and XPS. Tests on chloro-benzene have then been carried out in order to study the resistance of the VO{sub x}, CrO{sub x} and Mn{sub 3}O{sub 4} phases on chlorine compounds. This step has revealed the resistance of VO{sub x}, the low deactivation of CrO{sub x} and the strong deactivation of Mn{sub 3}O{sub 4} when the chlorine atom is present. The chlorine compound which deactivates the catalyst has been identified and the reversibility of the deactivation revealed. In conclusion, it can be said that the surface species VO{sub x} supported on TiO{sub 2} show the best activity for the destruction of the dioxines. (O.M.)

  17. Aspects of phytoremediation of organic pollutants

    DEFF Research Database (Denmark)

    Trapp, Stefan; Karlson, U.

    2001-01-01

    Phytoremediation is a quite novel technique to clean polluted soils using plants. In theory, phytoremediation methods are cheap, are accepted by the public and, compared to physical or chemical approaches, are ecologically advantageous. Until today, however, there are only a few examples...... of successful applications. One reason is that the processes involved are complex, and a full clean up may require many years. Plants affect the water balance of a site, they change redox potential and pH, and stimulate microbial activity of the soil. These indirect influences may accelerate degradation...... and phytodegradation, pump and tree, land farming, phytovolatilisation, hydraulic control and more. Already in use are plants (and here willow, poplar and grass) for the degradation of petroleum products, aromatic hydrocarbons (BTEX), chlorinated solvents, explosives and cyanides. However, phytotoxicity and pollutant...

  18. 土壤中 6 种氯代多环芳烃测定方法的建立及应用%Method Development and Application for the Determination of Chlorinated Polycyclic Aromatic Hydrocarbons in Soil

    Institute of Scientific and Technical Information of China (English)

    原文婷; 高占啟; 孙成

    2015-01-01

    建立了加速溶剂萃取、凝胶渗透色谱( GPC)与气相色谱-质谱联用测定土壤中6种氯代多环芳烃的分析方法. 研究证实该法的最佳萃取条件为:10.34 MPa压力,100 ℃萃取温度下,以1:1(V/V)的正己烷/二氯甲烷为萃取溶剂,静态萃取10 min,循环4次. GPC净化过程用乙酸乙酯和环己烷的混合液1:1(V/V)做洗脱液,目标物的收集时间为25~35 min.方法对Cl-PAHs在1~500 μg/L范围内线性良好,相关系数R2 为0.998 4~0.999 7;LOD和LOQ分别为2.6~25.1 pg/g和8.7~83.6 pg/g;各目标物的低浓度回收率为64.1%~117.6%,RSD<12.05%;高浓度回收率为59.1%~105.3%,RSD<9.81%. 研究证实该法满足定量分析的要求,并应用该法对某化工园进行了氯代多环芳烃的检测.%A method was developed for the determination of 6 chlorinated polycyclic aromatic hydrocarbons ( Cl-PAHs) in soil by accelerated solvent extraction ( ASE) , gel permeation chromatography ( GPC) coupled with GC-MS.The optimal ASE efficiency was obtained when using 1:1 ( V:V) dichloromethane/n-hexane as the extraction solvent , and performing the static extraction under 10.34 MPa pressure for 10 min at 100 ℃for four times repeatedly .The obtained extract was passed through GPC to clean up and eluted with 1:1 ( V:V) cyclohexane/ethyl acetate .The fraction was collected between 25 and 35 min.Good linearity was observed in the range of 1 to 500μg/L of Cl-PAHs, with correlation coefficients varying from 0.9984 to 0.9997.The limits of detection and limits of quantification were 2.6~25 pg/g and 8.7~83.6 pg/g, respectively.The recoveries for the studied Cl-PAHs ranged from 64.1%to 117.6%with the relative standard deviations less than 12.05%when the spiked concentration was low .When the spiked concentration was high , the recoveries ranged from 59.1%to 105.3%with the relative standard deviations less than 9.81%.This method was shown to meet the requirement for quantification analysis .It was applied in the determination

  19. Dechlorination of chlorinated phenols by subnanoscale Pd{sup 0}/Fe{sup 0} intercalated in smectite: pathway, reactivity, and selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hanzhong; Wang, Chuanyi, E-mail: jiahz0143@aliyun.com

    2015-12-30

    Graphical abstract: Dechlorination process of pentachlorophenol (PCP) by smectite-templated Pd{sup 0}/Fe{sup 0}. - Highlights: • Smectite was employed as templated matrix to prepare subnanoscale Pd{sup 0}/Fe{sup 0} particles. • Dechlorination rate depends linearly on the Pd content as its loadings <0.065 wt.%. • Dechlorination rates correlate with the total charge of C on chlorinated phenols. • The dechlorination selectivity relies on charges of individual C in aromatic ring. - Abstract: Smectite clay was employed as templated matrix to prepare subnanoscale Pd{sup 0}/Fe{sup 0} particles, and their components as well as intercalated architectures were well characterized by X-ray energy dispersive spectroscopy (X-EDS) and X-ray diffraction (XRD). Furthermore, as-prepared Pd{sup 0}/Fe{sup 0} subnanoscale nanoparticles were evaluated for their dechlorination effect using chlorinated phenols as model molecules. As a result, pentachlorophenol (PCP) is selectively transformed to phenol in a stepwise dechlorination pathway within 6 h, and the dechlorination rate constants show linearly relationship with contents of Pd as its loadings <0.065%. Comparing with PCP, other chlorinated phenols display similar degradation pattern but within much shorter time frame. The dechlorination rate of chlorinated phenols increases with decreasing in number of -Cl attached to aromatic ring, which can be predicted by the total charge of the aromatic ring, exhibiting an inversely linear relationship with the dechlorination rates. While the selectivity of dechlorination depends on the charges associated with the individual aromatic carbon. Chloro-functional groups at the ortho-position are easier to be dechlorinated than that at meta- and para- positions yielding primarily 3,4,5-TCP as intermediate from PCP, further to phenol. The effective dechlorination warrants their potential utilizations in development of in-situ remediation technologies for organic pollutants in contaminated

  20. Implications of polluted soil biostimulation and bioaugmentation with spent mushroom substrate (Agaricus bisporus) on the microbial community and polycyclic aromatic hydrocarbons biodegradation.

    Science.gov (United States)

    García-Delgado, Carlos; D'Annibale, Alessandro; Pesciaroli, Lorena; Yunta, Felipe; Crognale, Silvia; Petruccioli, Maurizio; Eymar, Enrique

    2015-03-01

    Different applications of spent Agaricus bisporus substrate (SAS), a widespread agro-industrial waste, were investigated with respect to the remediation of a historically polluted soil with Polycyclic Aromatic Hydrocarbons (PAH). In one treatment, the waste was sterilized (SSAS) prior to its application in order to assess its ability to biostimulate, as an organic amendment, the resident soil microbiota and ensuing contaminant degradation. For the other treatments, two bioaugmentation approaches were investigated; the first involved the use of the waste itself and thus implied the application of A. bisporus and the inherent microbiota of the waste. In the second treatment, SAS was sterilized and inoculated again with the fungus to assess its ability to act as a fungal carrier. All these treatments were compared with natural attenuation in terms of their impact on soil heterotrophic and PAH-degrading bacteria, fungal growth, biodiversity of soil microbiota and ability to affect PAH bioavailability and ensuing degradation and detoxification. Results clearly showed that historically PAH contaminated soil was not amenable to natural attenuation. Conversely, the addition of sterilized spent A. bisporus substrate to the soil stimulated resident soil bacteria with ensuing high removals of 3-ring PAH. Both augmentation treatments were more effective in removing highly condensed PAH, some of which known to possess a significant carcinogenic activity. Regardless of the mode of application, the present results strongly support the adequacy of SAS for environmental remediation purposes and open the way to an attractive recycling option of this waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Iron-impregnated titania composites for the decomposition of low-concentration aromatic organic pollutants under UV and visible light irradiation

    Institute of Scientific and Technical Information of China (English)

    Wan-Kuen Jo; Joon Yeob Lee

    2013-01-01

    Fe-TiO2 photocatalysts with different ratios of Fe to Ti were prepared by a sol-gel process using tetra-n-butyl titanium and iron(III) nitrate as Ti and Fe sources, respectively. The photocatalytic function of the prepared composites was examined for the decomposition of low-concentration (0.1 ppm) airborne benzene, toluene, ethyl benzene, and o-xylene (BTEX). The Fe-TiO2 composites were characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy. The time-series ratios of outlet to inlet concentrations of toluene, ethyl benzene, and o-xylene target chemicals, as determined by the Fe-TiO2 composites under visible light exposure, were lower than or similar to those of the reference TiO2 photocatalyst. Moreover, the time-series ratios of outlet to inlet concentrations of the three compounds, as deter-mined for the Fe-TiO2 composites, increased as the ratio of Fe to Ti increased from 0.001 to 0.010. In contrast, under UV exposure, the time-series ratios of outlet to inlet concentrations of BTEX, deter-mined for the Fe-TiO2 composites, were similar to or higher than those obtained from the reference TiO2 photocatalyst. Fe-TiO2 composites with an optimal Fe to Ti ratio could effectively be applied for the purification of low-concentration aromatic organic pollutants.

  2. Distribution of persistent organic pollutants, polycyclic aromatic hydrocarbons and trace elements in soil and vegetation following a large scale landfill fire in northern Greece.

    Science.gov (United States)

    Chrysikou, Loukia; Gemenetzis, Panagiotis; Kouras, Athanasios; Manoli, Evangelia; Terzi, Eleni; Samara, Constantini

    2008-02-01

    Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), including hexaclorocyclohexanes (HCHs) and DDTs, as well as trace elements were determined in soil and vegetation samples collected from the surrounding area of the landfill "Tagarades", the biggest in northern Greece, following a large scale fire involving approximately 50,000 tons of municipal waste. High concentrations of total PAHs, PCBs and heavy metals were found inside the landfill (1475 microg kg(-1) dw, 399 microg kg(-1) dw and 29.8 mg kg(-1) dw, respectively), whereas concentrations in the surrounding soils were by far lower ranging between 11.2-28.1 microg kg(-1) dw for PAHs, 4.02-11.2 microg kg(-1) dw for PCBs and 575-1207 mg kg(-1) dw for heavy metals. The distribution of HCHs and DDTs were quite different since certain soils exhibited equal or higher concentrations than the landfill. In vegetation, the concentrations of PAHs, PCBs, HCHs and DDTs ranged from 14.1-34.7, 3.64-25.9, 1.41-32.1 and 0.61-4.03 microg kg(-1) dw, respectively, while those of heavy metals from 81 to 159 mg kg(-1) dw. The results of the study indicated soil and vegetation pollution levels in the surroundings of the landfill comparable to those reported for other Greek locations. The impact from the landfill fire was not evident partially due to the presence of recent and past inputs from other activities (agriculture, vehicular transport, earlier landfill fires).

  3. Effects of prenatal exposure to air pollutants (polycyclic aromatic hydrocarbons) on the development of brain white matter, cognition, and behavior in later childhood.

    Science.gov (United States)

    Peterson, Bradley S; Rauh, Virginia A; Bansal, Ravi; Hao, Xuejun; Toth, Zachary; Nati, Giancarlo; Walsh, Kirwan; Miller, Rachel L; Arias, Franchesca; Semanek, David; Perera, Frederica

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and neurotoxic environmental contaminants. Prenatal PAH exposure is associated with subsequent cognitive and behavioral disturbances in childhood. To identify the effects of prenatal PAH exposure on brain structure and to assess the cognitive and behavioral correlates of those abnormalities in school-age children. Cross-sectional imaging study in a representative community-based cohort followed up prospectively from the fetal period to ages 7 to 9 years. The setting was urban community residences and an academic imaging center. Participants included a sample of 40 minority urban youth born to Latina (Dominican) or African American women. They were recruited between February 2, 1998, and March 17, 2006. Morphological measures that index local volumes of the surface of the brain and of the white matter surface after cortical gray matter was removed. We detected a dose-response relationship between increased prenatal PAH exposure (measured in the third trimester but thought to index exposure for all of gestation) and reductions of the white matter surface in later childhood that were confined almost exclusively to the left hemisphere of the brain and that involved almost its entire surface. Reduced left hemisphere white matter was associated with slower information processing speed during intelligence testing and with more severe externalizing behavioral problems, including attention-deficit/hyperactivity disorder symptoms and conduct disorder problems. The magnitude of left hemisphere white matter disturbances mediated the significant association of PAH exposure with slower processing speed. In addition, measures of postnatal PAH exposure correlated with white matter surface measures in dorsal prefrontal regions bilaterally when controlling for prenatal PAH. Our findings suggest that prenatal exposure to PAH air pollutants contributes to slower processing speed, attention-deficit/hyperactivity disorder symptoms

  4. Polycyclic aromatic hydrocarbons (PAHs) in sediments from lake Lille Lungegårdsvannet in Bergen, western Norway; appraising pollution sources from the urban history.

    Science.gov (United States)

    Andersson, Malin; Klug, Martin; Eggen, Ola Anfin; Ottesen, Rolf Tore

    2014-02-01

    This study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Bergen and determine the effect of specific point sources, as well as diffuse sources, and also help assess the risk of remediation plans. By using several organic compounds, metals and cyanide, we demonstrate the more accurate timing of sedimentation. The PAH results display very low concentrations in pre-industrial times, followed by a general increase that is punctuated by a few significant concentration increases. These most probably correspond to urban fires, domestic heating, gaswork activity and most recently due to traffic pollution. At the same depth as a significant rise in concentration from background levels occurred, the high relative occurrence of low-molecular-weight PAH-compounds, such as naphthalene, were replaced by heavier compounds, thus indicating a permanent change in source. The general observation, using ratios, is that the sources have shifted from pre-industrial pure wood and coal combustion towards mixed and petrogenic sources in more recent times. The (14)C dating provides evidence that the sedimentation rate stayed more-or-less constant for 4,500 years (from 7200 to 2700 calibrated years before present (calyr BP)), before isostatic uplift isolated the water body and the sedimentation rate decreased or sediments were eroded. The sediment input increased again when habitation and industrial activities encroached on the lake. The (14)C dating does not provide consistent data in that period, possibly due to the fact that the lake has been used as a waste site throughout the history of Bergen city. Therefore, results from (14)C dating from anthropogenically influenced sediments should be used with caution.

  5. Characterization of EPA's 16 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in tank bottom solids and associated contaminated soils at oil exploration and production sites in Texas.

    Science.gov (United States)

    Bojes, Heidi K; Pope, Peter G

    2007-04-01

    The purpose of this study was to determine the concentration and types of polycyclic aromatic hydrocarbons (PAHs), a group of environmentally toxic and persistent chemicals, at contaminated oil exploration and production (E&P) sites located in environmentally sensitive and geographically distinct areas throughout Texas. Samples of tank bottom solids, the oily sediment that collects at the bottom of the tanks, were collected from inactive crude oil storage tanks at E&P sites and hydrocarbon contaminated soil samples were collected from the area surrounding each tank that was sampled. All samples were analyzed for the 16 PAH priority pollutant listed by US EPA and for total petroleum hydrocarbons (TPH). The results demonstrate that overall average PAH concentrations were significantly higher in tank bottom solids than in contaminated soils. Total PAH concentrations decreased predictably with diminishing hydrocarbon concentrations; but the percent fraction of carcinogenic PAHs per total measured PAH content increased from approximately 12% in tank bottom solids to about 46% in the contaminated soils. These results suggest that the PAH content found in tank bottom solids cannot reliably be used to predict the PAH content in associated contaminated soil. Comparison of PAHs to conservative risk-based screening levels for direct exposure to soil and leaching from soil to groundwater indicate that PAHs are not likely to exceed default risk-based thresholds in soils containing TPH of 1% (10,000mg/kg) or less. These results show that the magnitude of TPH concentration may be a useful indicator of potential risk from PAHs in crude oil-contaminated soils. The results also provide credibility to the 1% (10,000mg/kg) TPH cleanup level, used in Texas as a default management level at E&P sites located in non-sensitive areas, with respect to PAH toxicity.

  6. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

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

  7. Efficient dechlorination of chlorinated solvent pollutants under UV irradiation by using the synthesized TiO2 nano-sheets in aqueous phase.

    Science.gov (United States)

    Ndong, Landry Biyoghe Bi; Ibondou, Murielle Primaelle; Miao, Zhouwei; Gu, Xiaogang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Mbadinga, Serge Maurice

    2014-05-01

    Titanium dioxide (TiO2), which is the widely used photo-catalyst, has been synthesized by simple hydrothermal solution containing tetrabutyl titanate and hydrofluoric acid. The synthesized product has been applied to photo-degradation in aqueous phase of chlorinated solvents, namely tetrachloroethene (PCE), trichloroethene (TCE) and 1,1,1-trichloroethane (TCA). The photo-degradation results revealed that the degradation of these harmful chemicals was better in UV/synthesized TiO2 system compared to UV/commercial P25 system and UV only system. The photo-catalytic efficiency of the synthesized TiO2 was 1.4, 1.8 and 3.0 folds higher compared to the commercial P25 for TCA, TCE and PCE degradation, respectively. Moreover, using nitrobenzene (NB) as a probe of hydroxyl radical (·OH), the degradation rate was better over UV/synthesized TiO2, suggesting the high concentration of ·OH generated in UV/synthesized TiO2 system. In addition, ·OH concentration was confirmed by the strong peak displayed in EPR analysis over UV/synthesized TiO2 system. The characterization result using XRD and TEM showed that the synthesized TiO2 was in anatase form and consisted of well-defined sheet-shaped structures having a rectangular outline with a thickness of 4 nm, side length of 50 nm and width of 33 nm and a surface 90.3 m(2)/g. XPS analysis revealed that ≡Ti-F bond was formed on the surface of the synthesized TiO2. The above results on both photocatalytic activity and the surface analysis demonstrated the good applicability of the synthesized TiO2 nano-sheets for the remediation of chlorinated solvent contaminated groundwater.

  8. The role of natural chlorinated hydroquinone metabolites in ligninolytic fungi

    NARCIS (Netherlands)

    Teunissen, P.J.M.

    1999-01-01

    Ligninolytic Basidiomycetes have been reported to produce a wide variety of chloroaromatic compounds as secondary metabolites, which are structurally similar to environmental pollutants. Among these are chlorinated hydroquinone metabolites (CHM), such as 2-chloro-1,4-dimethoxybenzene

  9. Bromoform production in tropical open-ocean waters: OTEC chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, E.O.; Valentine, R.

    1981-09-01

    The bromoform, and other volatile organics produced while chlorinating both the evaporator and condenser seawater during operation of the one megawatt (1 MW) OTEC-1 test facility are reported. Although many halogenated compounds might be produced as a result of chlorination, the quantitative analyses in this study focused on volatile EPA priority pollutants. Bromoform is the compound specifically recognized as a potential pollutant. Its concentration may be indicative of other halogenated species.

  10. Strong Impact on the Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Community of a PAH-Polluted Soil but Marginal Effect on PAH Degradation when Priming with Bioremediated Soil Dominated by Mycobacteria

    DEFF Research Database (Denmark)

    Johnsen, Anders R.; Schmidt, Stine; Hybholdt, Trine K.;

    2007-01-01

    Bioaugmentation of soil polluted with polycyclic aromatic hydrocarbons (PAHs) is often disappointing because of the low survival rate and low activity of the introduced degrader bacteria. We therefore investigated the possibility of priming PAH degradation in soil by adding 2% of bioremediated soil...... with a high capacity for PAH degradation. The culturable PAH-degrading community of the bioremediated primer soil was dominated by Mycobacterium spp. A microcosm containing pristine soil artificially polluted with PAHs and primed with bioremediated soil showed a fast, 100- to 1,000-fold increase in numbers...... of culturable phenanthrene-, pyrene-, and fluoranthene degraders and a 160-fold increase in copy numbers of the mycobacterial PAH dioxygenase gene pdo1. A nonpolluted microcosm primed with bioremediated soil showed a high rate of survival of the introduced degrader community during the 112 days of incubation...

  11. Primary investigation of the pollution status of polycyclic aromatic hydrocarbons (PAHs) in water and soil of Xuanwei and Fuyuan, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    LU JunGang; XU RenJi; ZHANG QingHua; LIU JiYan; LIAO ChunYang; WEI FuSheng

    2009-01-01

    Lung cancer incidence in Xuanwei and Fuyuan is extremely high. The air pollution, especially indoor airborne PAHs generated by burning smoky coals, has been considered as the most probable reason. The air pollution may affect drinking water and soil through dry and wet deposition. In this study, the concentrations of PAHs in water and soil samples from Xuanwei and Fuyuan were monitored to investigate the influence of atmospheric PAHs pollution on water and soil. No obvious PAHs pollution in water was found in these two areas, indicating that airborne PAHs have no apparent effect on the drinking water (well water). The smoky coal combustion from household and industry, such as the activities related to power plants, coking plants and chemical industries, is responsible for the soil PAHs pollution in these two areas. The soil pollution might be the reemission source and would pose long-term threat to the local environment and health of residents.

  12. Aqueous reactions of chlorine dioxide with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Rav-Acha, C.; Choshen, E.

    1987-11-01

    In contrast to mechanisms proposed earlier in the literature, according to which chlorine dioxide (ClO/sub 2/) reacts with various hydrocarbons in aqueous media by abstracting allylic or benzylic hydrogens, it is shown that ClO/sub 2/ reacts with olefins through initial electron transfer. Hydrocarbons that can undergo facile oxidation, such as polycyclic aromatic hydrocarbons (PAH) and some olefins, react with ClO/sub 2/ quite rapidly, while saturated aliphatic hydrocarbons, some aromatic hydrocarbons, and olefins substituted with electron-withdrawing groups remain unreactive. This was substantiated by comparing the reactivities toward ClO/sub 2/ of a variety of hydrocarbons, including aliphatic and aromatic hydrocarbons, saturated and unsaturated acids, PAH, or cyclic and acyclic olefins. The results were supported by a detailed kinetic and product study of the reaction between ClO/sub 2/ and some model compounds.

  13. Polycyclic aromatic hydrocarbon exposure in household air pollution from solid fuel combustion among the female population of Xuanwei and Fuyuan counties, China

    NARCIS (Netherlands)

    Downward, George S.; Hu, Wei; Rothman, Nat; Reiss, Boris; Wu, Guoping; Wei, Fusheng; Chapman, Robert S.; Portengen, Lutzen; Qing, Lan; Vermeulen, Roel

    2014-01-01

    Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning "smoky" (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source an

  14. Polycyclic aromatic hydrocarbon exposure in household air pollution from solid fuel combustion among the female population of Xuanwei and Fuyuan counties, China

    NARCIS (Netherlands)

    Downward, George S.|info:eu-repo/dai/nl/412435667; Hu, Wei; Rothman, Nat; Reiss, Boris|info:eu-repo/dai/nl/314119205; Wu, Guoping; Wei, Fusheng; Chapman, Robert S.; Portengen, Lutzen|info:eu-repo/dai/nl/269224742; Qing, Lan; Vermeulen, Roel|info:eu-repo/dai/nl/216532620

    2014-01-01

    Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning "smoky" (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source

  15. Effect of water-washing on the co-removal of chlorine and heavy metals in air pollution control residue from MSW incineration.

    Science.gov (United States)

    Yang, Zhenzhou; Tian, Sicong; Ji, Ru; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2017-06-24

    The present study systemically investigated the effect of a water-washing process on the removal of harmful chlorides, sulfates, and heavy metals in the air pollution control (APC) residue from municipal solid wastes incineration (MSWI), for sake of a better reuse and disposal of this kind of waste. In addition, the kinetic study was conducted to reveal the releasing mechanism of relevant element in the residue. The results show that, over 70wt.% of chlorides and nearly 25wt.% of sulfates in the residue could be removed by water washing. Based on an economical consideration, the optimal operation conditions for water washing of APC residue was at liquid/solid (L/S) ratio of 3mL:1g and extracting time of 5min. As expected, the concentrations of Co, Cr, Fe, Ni, V and Cu in the washing effluent increased with time during the washing process. However, the extracting regime differs among different heavy metals. The concentrations of Ba and Mn increased firstly but declined afterwards, and concentrations of Pb and Zn gradually declined while Cd and As kept constant with the increase of extracting time. It is worth mentioning that the bubbling of CO2 into the washing effluent is promisingly effective for a further removal of Pb, Cu and Zn. Furthermore, kinetic study of the water washing process reveals that the extracting of heavy metals during water washing follows a second-order model. Copyright © 2017. Published by Elsevier Ltd.

  16. Thermochemical properties and phase behavior of halogenated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Fu, Jinxia; Suuberg, Eric M

    2012-03-01

    Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene, and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464 K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared with parent compounds but does not necessarily increase the enthalpy of sublimation. Furthermore, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared with single halogen-substituted polycyclic aromatic hydrocarbons. In addition, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis.

  17. 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 occur via d

  18. Application of a biofilm formed by a mixture of yeasts isolated in Vietnam to degrade aromatic hydrocarbon polluted wastewater collected from petroleum storage.

    Science.gov (United States)

    Nhi Cong, Le Thi; Ngoc Mai, Cung Thi; Thanh, Vu Thi; Nga, Le Phi; Minh, Nghiem Ngoc

    2014-01-01

    In this study, three good biofilm-forming yeast strains, including Candida viswanathii TH1, Candida tropicalis TH4 and Trichosporon asahii B1, were isolated from oil-contaminated water and sediment samples collected in coastal zones of Vietnam. These strains were registered in the GenBank database with the accession numbers JX129175, JX129176 and KC139404 for strain TH1, TH4 and B1, respectively. The biofilm formed by a mixture of these organisms degraded 90, 85, 82 and 67% of phenol, naphthalene, anthracene and pyrene, respectively, after a 7-day incubation period using an initial concentration of 600 ppm phenol and 200 ppm of each of the other compounds. In addition, this biofilm completely degraded these aromatic compounds, which were from wastewater collected from petroleum tanks in Do Xa, Hanoi after 14 days of incubation based on gas chromatography mass spectrometry analysis. To the best of our knowledge, reports on polycyclic aromatic hydrocarbon and phenol degradation by biofilm-forming yeasts are limited. The results obtained indicate that the biofilm formed by multiple yeast strains may considerably increase the degradation efficiency of aromatic hydrocarbon compounds, and may lead to a new approach for eliminating petroleum oil-contaminated water in Vietnam.

  19. 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.

  20. 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…

  1. Aspects of phytoremediation of organic pollutants

    DEFF Research Database (Denmark)

    Trapp, Stefan; Karlson, U.

    2001-01-01

    Phytoremediation is a quite novel technique to clean polluted soils using plants. In theory, phytoremediation methods are cheap, are accepted by the public and, compared to physical or chemical approaches, are ecologically advantageous. Until today, however, there are only a few examples of succe......Phytoremediation is a quite novel technique to clean polluted soils using plants. In theory, phytoremediation methods are cheap, are accepted by the public and, compared to physical or chemical approaches, are ecologically advantageous. Until today, however, there are only a few examples...... of successful applications. One reason is that the processes involved are complex, and a full clean up may require many years. Plants affect the water balance of a site, they change redox potential and pH, and stimulate microbial activity of the soil. These indirect influences may accelerate degradation...... and phytodegradation, pump and tree, land farming, phytovolatilisation, hydraulic control and more. Already in use are plants (and here willow, poplar and grass) for the degradation of petroleum products, aromatic hydrocarbons (BTEX), chlorinated solvents, explosives and cyanides. However, phytotoxicity and pollutant...

  2. Assessing Polycyclic Aromatic Hydrocarbons (PAHs) using passive air sampling in the atmosphere of one of the most wood-smoke-polluted cities in Chile: The case study of Temuco.

    Science.gov (United States)

    Pozo, Karla; Estellano, Victor H; Harner, Tom; Diaz-Robles, Luis; Cereceda-Balic, Francisco; Etcharren, Pablo; Pozo, Katerine; Vidal, Victor; Guerrero, Fabián; Vergara-Fernández, Alberto

    2015-09-01

    This study addresses human health concerns in the city of Temuco that are attributed to wood smoke and related pollutants associated with wood burning activities that are prevalent in Temuco. Polycyclic Aromatic Hydrocarbons (PAHs) were measured in air across urban and rural sites over three seasons in Temuco using polyurethane foam (PUF) disk passive air samplers (PUF-PAS). Concentrations of ΣPAHs (15 congeners) in air ranged from BDL to ∼70 ng m(-3) and were highest during the winter season, which is attributed to emissions from residential heating by wood combustion. The results for all three seasons showed that the PAH plume was widespread across all sites including rural sites on the outskirts of Temuco. Some interesting variations were observed between seasons in the composition of PAHs, which were attributed to differences in seasonal point sources. A comparison of the PAH composition in the passive samples with active samples (gas+particle phase) from the same site revealed similar congener profiles. Overall, the study demonstrated that the PUF disk passive air sampler provides a simple approach for measuring PAHs in air and for tracking effectiveness of pollution control measures in urban areas in order to improve public health.

  3. Influence of pollution of boron chlorinity ratio

    Digital Repository Service at National Institute of Oceanography (India)

    Narvekar, P.V.; Zingde, M.D.

    Presence of boron in domestic wastewater has resulted in high B/CI ratio at some locations in the coastal water around Bombay. A widest range (0.215-0.281) of B/CI was observed at a location with high influence of wastewater release. The mean B...

  4. Effects of oil pollution at Kuwait's greater Al-Burgan oil field on polycyclic aromatic hydrocarbon concentrations in the tissues of the desert lizard Acanthodactylus scutellatus and their ant prey.

    Science.gov (United States)

    Al-Hashem, Mona A; Brain, Paul F; Omar, Samira A

    2007-11-01

    Using indicator species to monitor the effects of oil pollution was thought to be useful to assess whether local desert reptiles and their insect prey could fulfill such a role in an area damaged in the second Gulf War (1990). Polluted sites with apparently different degrees of contamination (namely tar mat, soot, and clear sites) located at Kuwait's Greater Al-Burgan oil field were compared with control areas outside this region in study conducted in 2002. Five Acanthodactylus scutellatus lizards from each study and control site were humanely killed and stored in a freezer at -20 degrees C until analysis. Ants from the same sites were also collected and treated in a similar manner. Lizard and ant whole body tissues were subjected to gas chromatography-mass spectrometry (GC-MS) to determine concentrations of petroleum hydrocarbons (HCs). The study concentrated on sixteen polycyclic aromatic hydrocarbons (PAHs), EPA priority pollutants used as indicators of petrogenic HC contamination. There were significantly different concentrations of total PAHs in lizards and ants among all four study sites. Of the 16 PAHs, phenanthrene, fluoranthene, and benzo[a]anthracene were present in both lizard and ant samples from the Greater Al-Burgan oil field sites irrespective of the apparent degree of pollution but were undetectable in materials from the control sites. The range of total PAHs in lizards was 26.5-301 ng g(-1) and it was 6.7-82.1 ng g(-1) in ants. Concentrations increased progressively along an expected contamination gradient. Total PAHs were detected in biota even in an area (clear site) that did not appear, virtually, to contain petroleum soil pollution which supports the value of indicator biota species. For all three sites where PAHs were found in biota, the ratio of total PAHs in ants to lizards was consistently 3.3-3.4. These data show that, although 12 years have passed since the Kuwait oil spill catastrophe, all sites are still contaminated with PAHs. Use of

  5. 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...

  6. 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...

  7. Development of a system for "in situ" determination of chlorinated hydrocarbons in groundwater

    OpenAIRE

    Boutsiadou, Xanthippe; Hunkeler, Daniel

    2012-01-01

    Volatile organic compounds (VOCs), and especially chlorinated hydrocarbons, are common groundwater contaminants. Efficient monitoring that can be conducted directly in the field is needed to detect a possible pollution by organic contaminants such as chlorinated hydrocarbons. The general aim of this project is to develop a portable instrument for the in situ measurement of chlorinated hydrocarbons in groundwater. The instrument relies on the transfer of volatile organic compounds to the gas p...

  8. A kinetic study of several aromatic compounds oxidation: applied to pollutants formation in car engines; Etude cinetique de l'oxydation de composes aromatiques: application a la formation de polluants dans les moteurs automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Pengloan, G.

    2001-12-15

    Commercial fuels contain a multitude of chemical compounds. Their incomplete combustion in car engines leads to pollutants emission. The aim of this study is to improve our knowledge of oxidation kinetic mechanisms at high temperature for aromatic hydrocarbons because of their importance in fuels composition. Kinetics of benzene, toluene, ethyl-benzene and styrene combustion was studied, at equivalence ratio in the range 0.5 to 1.5, by means of two experimental apparatus: a jet-stirred reactor (JSR) and a shock tube (ST). In the JSR, reactive mixtures, diluted by N{sub 2}, were oxidized at atmospheric pressure in the temperature range 950 to 1400 K. Concentration profiles of sampled stable species were measured, at a steady residence time, by gas chromatography (GC/MS, GC/FID/TCD). In the ST, temperature and pressure ranges were higher: 1300 < T(K) < 2000, 1 < P(bar) < 20. Ignition delays were measured by recording OH emission profiles at 306 nm. A detailed kinetic reaction mechanism for the oxidation of aromatic hydrocarbons at high temperature was proposed. This mechanism includes 936 reactions and 125 species. It's based on the kinetic scheme of Ristori et al. (2001),It was further validated in the present work by modeling the ignition of benzene and toluene. Ethyl-benzene and styrene sub-mechanisms were developed. The agreement between the simulations and JSR experimental data is satisfactory. The ignition delays are well simulated. However, the modeling of concentration profiles needs improvements: defaults in the mechanism of benzene have repercussions on the predicted reactivity of ethyl-benzene and styrene which is higher than observed in the experiments. (author)

  9. PCDD/F Formation mechanism: effect of surface composition on chlorination and condensation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, S.; Nath, P.

    2002-07-01

    The post-combustion zone immediately following the incineration (flame) zone is a potential pollutant formation zone as it contains excess O{sub 2} (3-9%), sufficient residence time (from sub seconds to minutes) and catalytically active fly ash particles. This is an ideal reaction environment for the C{sub 1} and C{sub 2} compounds exiting the flame zone to undergo condensation and chlorination reactions. Heterogeneous reactions of short-chain aliphatic and chlorinated aliphatic combustion products in both high-temperature and low-temperature post-combustion zones can be important in the formation of larger organic pollutants (e. g. polychlorinated biphenyls, polychlorianted dibenzo-p-dioxins/dibenzofurans, chlorohenols, chlorobenzenes, etc). Fly ash formed in the combustion process provides the active surface for chlorination/condensation reactions in the post-combustion zone. The presence of several metals in flay ashes give rise to the question whether there is one specific metal or a complex of metals that is responsoble for the chlorination. Although fly ash contains many metallic species, most researchers investigations the PCDD/F formation mechanisms have used copper as the catalytic surface in their pollutant formation studies because copper is a known commercial oxychloriantion catalyst. The specific catalytic effects of various copper compounds in the formation of PCDD/F from aliphatica and aromatic compounds have been examined by us and a number of other investigators. In limited studies, iron compounds have also been used as PCDD/F formation catalysts, although these iron studies have produced contradictory results. Review of commercially important polymerization reactions shows that at varying temperatures and pressures, c and C{sub 4} olefinic polymerization reactions may be catalyzed by HCI-activated Al{sub 2}O{sub 3} SiO{sub 2} (aromatization also observed), aluminosilicates (1% Al{sub 2}O{sub 3} in SiO{sub 2}), and Fe oxides on aluminosilicates

  10. Aromatic graphene

    Science.gov (United States)

    Das, D. K.; Sahoo, S.

    2016-04-01

    In recent years graphene attracts the scientific and engineering communities due to its outstanding electronic, thermal, mechanical and optical properties and many potential applications. Recently, Popov et al. [1] have studied the properties of graphene and proved that it is aromatic but without fragrance. In this paper, we present a theory to prepare graphene with fragrance. This can be used as scented pencils, perfumes, room and car fresheners, cosmetics and many other useful household substances.

  11. Aromatic graphene

    Energy Technology Data Exchange (ETDEWEB)

    Das, D. K., E-mail: gour.netai@gmail.com [Department of Metallurgical and Material Science Engineering, National Institute of Technology Durgapur-713209, West Bengal (India); Sahoo, S., E-mail: sukadevsahoo@yahoo.com [Department of Physics, National Institute of Technology Durgapur-713209, West Bengal (India)

    2016-04-13

    In recent years graphene attracts the scientific and engineering communities due to its outstanding electronic, thermal, mechanical and optical properties and many potential applications. Recently, Popov et al. [1] have studied the properties of graphene and proved that it is aromatic but without fragrance. In this paper, we present a theory to prepare graphene with fragrance. This can be used as scented pencils, perfumes, room and car fresheners, cosmetics and many other useful household substances.

  12. Experimental infrared measurements for hydrocarbon pollutant determination in subterranean waters

    NARCIS (Netherlands)

    Lay-Ekuakille, A.; Palamara, I.; Caratelli, D.; Morabito, F.C.

    2013-01-01

    Subterranean waters are often polluted by industrial and anthropic effluents that are drained in subsoil. To prevent and control pollution, legislations of different developed countries require an online monitoring measurement, especially for detecting organic solvents (chlorinated and unchlorinated

  13. [Formation mechanism and chemical safety of nonintentional chemical substances present in chlorinated drinking water and wastewater].

    Science.gov (United States)

    Onodera, Sukeo

    2010-09-01

    This paper reviews the formation mechanism and chemical safety of nonintentional chemical substances (NICS) present in chlorine-treated water containing organic contaminants. Undesirable compounds, i.e., NICS, may be formed under certain conditions when chlorine reacts with organic matter. The rate and extent of chlorine consumption with organics are strongly dependent on their chemical structures, particularly whether double bonds or sulfur and nitrogen atoms occur in the molecules. Organothiophosphorus pesticides (P=S type) are easily oxidized to their phosphorus compounds (P=O type) in chlorinated water containing HOCl as little as 0.5 mg/l, resulting in an increase in cholinesterase-inhibitory activity. Chlorination of phenols in water also produces a series of highly chlorinated compounds, including chlorophenols, chloroquinones, chlorinated carboxylic acids, and polychlorinated phenoxyphenols (PCPPs). In some of these chloroquinones, 2,6-dichloroalkylsemiquinones exhibit a strong mutagenic response as do positive controls used in the Ames test. 2-phenoxyphenols in these PCPPs are particularly interesting, as they are present in the chlorine-treated phenol solution and they are also precursors (predioxins) of the highly toxic chlorinated dioxins. Polynuclear aromatic hydrocarbons (PAHs) were found to undergo chemical changes due to hypochlorite reactions to give chloro-substituted PAHs, oxygenated (quinones) and hydroxylated (phenols) compounds, but they exhibit a lower mutagenic response. In addition, field work was performed in river water and drinking water to obtain information on chemical distribution and their safety, and the results are compared with those obtained in the model chlorination experiments.

  14. Seasonal Variations in Health Hazards from Polycyclic Aromatic Hydrocarbons Bound to Submicrometer Particles at Three Characteristic Sites in the Heavily Polluted Polish Region

    Directory of Open Access Journals (Sweden)

    Barbara Kozielska

    2014-12-01

    Full Text Available Suspended particles with aerodynamic diameters not greater than 1 μm (PM1 were sampled at the urban background; regional background; and urban traffic points in southern Poland. In total, 120 samples were collected between 2 August 2009 and 27 December 2010. Sixteen polycyclic aromatic hydrocarbons (PAHs were determined in each sample. The samples were collected with a high volume sampler (Digitel. Afterwards, they were chemically analyzed with a gas chromatograph equipped with a flame ionization detector (Perkin Elmer Clarus 500. The mean concentration values of the PAH sum (ΣPAH and particular PAHs; the percentages of carcinogenic PAHs in total PAHs (ΣPAHcarc/ΣPAH; carcinogenic equivalent (CEQ; mutagenic equivalent (MEQ; and TCDD-toxic equivalent (TEQ were much higher in the winter (heating season than in the summer (non-heating one. For both periods, the resulting average values obtained were significantly higher (a few; and sometimes a several dozen times higher in the researched Polish region than the values observed in other areas of the world. Such results indicate the importance of health hazards resulting from PM1 and PM1-bound PAHs in this Polish area.

  15. Polycyclic aromatic hydrocarbon exposure in household air pollution from solid fuel combustion among the female population of Xuanwei and Fuyuan counties, China.

    Science.gov (United States)

    Downward, George S; Hu, Wei; Rothman, Nat; Reiss, Boris; Wu, Guoping; Wei, Fusheng; Chapman, Robert S; Portengen, Lutzen; Qing, Lan; Vermeulen, Roel

    2014-12-16

    Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning "smoky" (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source and stove design affects exposure. Indoor and personal PAH exposure resulting from solid fuel combustion in Xuanwei and Fuyuan was investigated using repeated 24 h particle bound and gas-phase PAH measurements, which were collected from 163 female residents of Xuanwei and Fuyuan. 549 particle bound (283 indoor and 266 personal) and 193 gas phase (all personal) PAH measurements were collected. Mixed effect models indicated that PAH exposure was up to 6 times higher when burning smoky coal than smokeless coal and varied by up to a factor of 3 between different smoky coal geographic sources. PAH measurements from unventilated firepits were up to 5 times that of ventilated stoves. Exposure also varied between different room sizes and season of measurement. These findings indicate that PAH exposure is modulated by a variety of factors, including fuel type, coal source, and stove design. These findings may provide valuable insight into potential causes of lung cancer in the area.

  16. Pollution assessment and source identifications of polycyclic aromatic hydrocarbons in sediments of the Yellow River Delta, a newly born wetland in China.

    Science.gov (United States)

    Yang, Zhifeng; Wang, Lili; Niu, Junfeng; Wang, Jingyi; Shen, Zhenyao

    2009-11-01

    The levels and possible sources of 16 priority polycyclic aromatic carbons (PAHs) in the sediments from the Yellow River Delta (YRD) were investigated. The total PAH concentrations ranged from 23.9 to 520.6 microg kg(-1) with a mean value of 150.9 microg kg(-1), indicating low or medium levels compared with reported values of other deltas. The concentrations of the 16 individual PAHs presented varied profiles among different regions. The ecological risk assessment of PAHs showed that adverse effects would rarely occur in the sediments of the YRD based on the effect range-low quotients and the probability risk assessment. The PAH compositions and the principal component analysis (PCA) with multiple linear regression (MLR) uniformly presumed the mixed sources of pyrogenic- and petrogenic-deriving PAHs in the YRD. By PCA with MLR, the contributions of major sources were quantified as 36.4% from oil burning, 33.1% from biomass combustion, and 30.5% from diesel emission sources.

  17. A novel approach for characterization of polycyclic aromatic hydrocarbon (PAH) pollution patterns in sediments from Guanabara Bay, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Christensen, Jan H; Tomasi, Giorgio; de Lemos Scofield, Arthur; de Fatima Guadalupe Meniconi, Maria

    2010-10-01

    A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio São João de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene).

  18. Formation and detoxification of reactive intermediates in the metabolism of chlorinated ethenes

    NARCIS (Netherlands)

    Vlieg, JETV; Janssen, DB; Hylckama Vlieg, Johan E.T. van

    2001-01-01

    Short-chain halogenated aliphatics, such as chlorinated ethenes, constitute a large group of priority pollutants. This paper gives an overview on the chemical and physical properties of chlorinated aliphatics that are critical in determining their toxicological characteristics and recalcitrance to b

  19. Facile Formation of Redox-Active Totally Organic Nanoparticles in Water by In Situ Reduction of Organic Precursors Stabilized through Aromatic-Aromatic Interactions by Aromatic Polyelectrolytes.

    Science.gov (United States)

    Flores, Mario E; Garcés-Jerez, Pablo; Fernández, Daniel; Aros-Perez, Gustavo; González-Cabrera, Diego; Álvarez, Eduardo; Cañas, Ignacio; Oyarzun-Ampuero, Felipe; Moreno-Villoslada, Ignacio

    2016-11-01

    The formation of redox-active, totally organic nanoparticles in water is achieved following a strategy similar to that used to form metal nanoparticles. It is based on two fundamental concepts: i) complexation through aromatic-aromatic interactions of a water-soluble precursor aromatic molecule with polyelectrolytes bearing complementary charged aromatic rings, and ii) reduction of the precursor molecule to achieve stabilized nanoparticles. Thus, formazan nanoparticles are synthesized by reduction of a tetrazolium salt with ascorbic acid using polyelectrolytes bearing benzene sulfonate residues of high linear aromatic density, but cannot be formed in the presence of nonaromatic polyelectrolytes. The red colored nanoparticles are efficiently encapsulated in calcium alginate beads, showing macroscopic homogeneity. Bleaching kinetics with chlorine show linear rates on the order of tenths of milli-meters per minute. A linear behavior of the dependence of the rate of bleaching on the chlorine concentration is found, showing the potential of the nanoparticles for chlorine sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Synthesis and evaluation of aromaticity and tautomerization of pyrazolopyridazin(on)es

    Indian Academy of Sciences (India)

    NURETT˙IN MENGES; ˙ISHAK BILDIRICI

    2017-06-01

    Aromaticity of pyrazolopyridazin(on)es was investigated using NICS(0), NICS(1), NICSzz(1), FIPC-NICS and HOMA aromaticity indexes and it was observed that aromaticity of pyridazin(on)es was amenable to aromaticity of pyrazole and vice versa. Some tautomeric forms of pyridazinone were analyzedand the localized orbital locator maps, electron density maps, Fuzzy, Laplacian, and Mayer bond order methods showed dominant form. Different substituents, amine, chlorine, phenyl, methyl, hydrogen, substituted-phenyl, etc. on both the rings were chosen to search out the substituent effect. Aromaticity of pyrazolopyridazin(on)es was searched out in detail for the first time.

  1. Biodegradation Rates of Aromatic Contaminants in Biofilm Reactors

    DEFF Research Database (Denmark)

    Arcangeli, Jean-Pierre; Arvin, Erik

    1995-01-01

    This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols, chlorophe......This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols...

  2. Changes in indoor pollutants since the 1950s

    Science.gov (United States)

    Weschler, Charles J.

    Over the past half-century there have been major changes in building materials and consumer products used indoors. Composite-wood, synthetic carpets, polymeric flooring, foam cushioning, plastic items and scented cleaning agents have become ubiquitous. The same is true for mechanical and electrical appliances such as washer/dryers, TVs and computers. These materials and products emit an array of chemicals including solvents, unreacted monomers, and additives. The consequent changes in emission profiles for indoor pollutants have been accompanied by modifications in building operations. Residences and non-residences are less ventilated than they were decades ago. Air-conditioned buildings are more numerous, especially in certain parts of the world. Most of these recirculate a high fraction of their air. The personal habits of building occupants, including the fraction who smoke indoors, have also changed. Taken together, these changes have altered the kind and concentrations of chemicals that occupants are exposed to in their homes, workplaces and schools. Since the 1950s, levels of certain indoor pollutants (e.g., formaldehyde, aromatic and chlorinated solvents, chlorinated pesticides, PCBs) have increased and then decreased. Levels of other indoor pollutants have increased and remain high (e.g., phthalate esters, brominated flame-retardants, nonionic surfactants and their degradation products). Many of the chemicals presently found in indoor environments, as well as in the blood and urine of occupants, were not present 50 years ago. Given the public's exposure to such species, there would be exceptional value in monitoring networks that provided cross-sectional and longitudinal information regarding pollutants found in representative buildings.

  3. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Wang, Juan [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhang, Yahe; Shi, Quan [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhang, Haifeng; Zhang, Yu [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Yang, Min, E-mail: yangmin@rcees.ac.cn [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-06-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AI{sub mod}), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water. - Highlights: • The formulas of 206 iodinated DBPs in chloraminated drinking water were proposed. • More than 68% of the I-DBPs might have aromatic or polycyclic aromatic structures. • Precursors with high aromaticity is preferential to form iodinated DBPs.

  4. The BIOZO process--a biofilm system combined with ozonation: occurrence of xenobiotic organic micro-pollutants in and removal of polycyclic aromatic hydrocarbons and nitrogen from landfill leachate.

    Science.gov (United States)

    Plósz, Benedek G Y; Vogelsang, Christian; Macrae, Kenneth; Heiaas, Harald H; Lopez, Antonio; Liltved, Helge; Langford, Katherine H

    2010-01-01

    We present an assessment of xenobiotic organic micro-pollutants (XOM) occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) in a novel biofilm system combined with ozonation, the BIOZO concept, treating partly stabilised landfill leachate. A novel, staged moving-bed biofilm reactor (SMBBR) design was implemented in laboratory- and pilot-scale, and the PAHs removal efficiency of controlled ozonation was assessed installing the ozonation step in the nitrate recirculation line (Position 1) or between the pre-anoxic and aerobic zones (Position 2). COD removal in a laboratory- and in a pilot-scale SMBBR system with and without ozonation is additionally addressed. Results obtained in a screening study (GC-ToF-MS) were used to compile a priority list of XOMs in leachate based on relative occurrence, showing PAHs as the predominant fraction. Biological treatment is shown to be an effective means to remove PAHs detected in the aqueous phase. PAH removal takes in most part place in the pre-anoxic zone, thereby decreasing toxicity exhibited by PAH on autotrophic nitrifier bacteria in the aerobic zone. Ozonation installed in Position 2 is shown to be superior over Position I in terms of COD, PAH and nitrogen removal efficiencies. We additionally demonstrate the potential of intermittent sludge ozonation as a means to decrease PAH concentrations in sludge wasted and to improve nitrogen removal in the BIOZO system.

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

    OpenAIRE

    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 wer...

  6. Emissions of polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, and dibenzofurans from incineration of nanomaterials.

    Science.gov (United States)

    Vejerano, Eric P; Holder, Amara L; Marr, Linsey C

    2013-05-07

    Disposal of some nanomaterial-laden waste through incineration is inevitable, and nanomaterials' influence on combustion byproduct formation under high-temperature, oxidative conditions is not well understood. This work reports the formation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated-dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from incineration of paper and plastic waste containing various nanomaterials, including titania, nickel oxide, silver, ceria, iron oxide, quantum dots, and C60-fullerene, in a laboratory-scale furnace. The presence of nanomaterials in the waste stream resulted in higher emissions of some PAH species and lower emissions of others, depending on the type of waste. The major PAH species formed were phenanthrene and anthracene, and emissions were sensitive to the amount of nanomaterials in the waste. Generally, there were no significant differences in emission factors for the larger PAH species when nanomaterials were added to the waste. The total PAH emission factors were on average ~6 times higher for waste spiked with nanomaterials v. their bulk counterparts. Emissions of chlorinated dioxins from poly(vinyl chloride) (PVC) waste were not detected; however, chlorinated furans were formed at elevated concentrations with wastes containing silver and titania nanomaterials, and toxicity was attributable mainly to 2,3,4,7,8-pentachlorodibenzofuran. The combination of high specific surface area and catalytic, including electrocatalytic, properties of nanomaterials might be responsible for affecting the formation of toxic pollutants during incineration.

  7. Oxidation of synthetic phenolic antioxidants during water chlorination.

    Science.gov (United States)

    Rodil, Rosario; Quintana, José Benito; Cela, Rafael

    2012-01-15

    The degradation of seven phenolic antioxidants and metabolites during chlorination was investigated. Under strong chlorination conditions (10 mg L(-1) chlorine, 24h), five of the target compounds were significantly degraded, while only BHT-Q (2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione) and BHT-CHO (3,5-di-tert-butyl-4-hydroxybenzaldehyde) were stable. The effect of the presence of bromide to the sample was only significant for BHA (butylated hydroxyanisole) resulting in increased disappearance rate as it is increased. Moreover, the disappearance kinetics were investigated at different concentrations of chlorine and pH of sample using a factorial experimental design. It was observed that the pH of the sample was a significant factor for BHT (butylated hydroxytoluene) and BHA, and chlorine concentration was significant for BHT, resulting in increased disappearance kinetics as they are increased. The degradation of these compounds has revealed two main processes: hydroxylation and oxidation of the aromatic system. The hydroxylated derivatives in some cases (e.g. from BHT-OH (2,6-di-tert-butyl-4-(hydroxymethyl)phenol) and BHT-COOH (3,5-di-tert-butyl-4-hydroxybenzoic acid)) are formed via the chlorinated and/or brominated intermediate. Moreover, the oxidation of the aromatic system leads to the quinone derivatives. The investigation of these by-products in real samples by solid-phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS) showed that derivatives of BHT, BHT-OH and/or BHT-COOH occurred in wastewater and drinking water samples analysed. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Reactions of chlorine with inorganic and organic compounds during water treatment-Kinetics and mechanisms: a critical review.

    Science.gov (United States)

    Deborde, Marie; von Gunten, Urs

    2008-01-01

    Numerous inorganic and organic micropollutants can undergo reactions with chlorine. However, for certain compounds, the expected chlorine reactivity is low and only small modifications in the parent compound's structure are expected under typical water treatment conditions. To better understand/predict chlorine reactions with micropollutants, the kinetic and mechanistic information on chlorine reactivity available in literature was critically reviewed. For most micropollutants, HOCl is the major reactive chlorine species during chlorination processes. In the case of inorganic compounds, a fast reaction of ammonia, halides (Br(-) and I(-)), SO(3)(2-), CN(-), NO(2)(-), As(III) and Fe(II) with HOCl is reported (10(3)-10(9)M(-1)s(-1)) whereas low chlorine reaction rates with Mn(II) were shown in homogeneous systems. Chlorine reactivity usually results from an initial electrophilic attack of HOCl on inorganic compounds. In the case of organic compounds, second-order rate constants for chlorination vary over 10 orders of magnitude (i.e. organic compounds are possible pathways. However, from a kinetic point of view, usually only electrophilic attack is significant. Chlorine reactivity limited to particular sites (mainly amines, reduced sulfur moieties or activated aromatic systems) is commonly observed during chlorination processes and small modifications in the parent compound's structure are expected for the primary attack. Linear structure-activity relationships can be used to make predictions/estimates of the reactivity of functional groups based on structural analogy. Furthermore, comparison of chlorine to ozone reactivity towards aromatic compounds (electrophilic attack) shows a good correlation, with chlorine rate constants being about four orders of magnitude smaller than those for ozone.

  9. 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

  10. Chlorine dioxide and hemodialysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.P. (Dartmouth Coll., Hanover, NH (USA). Dept. of Pharmacology and Toxicology)

    1989-05-01

    Because it has little or no tendency to generate carcinogenic trihalomethanes such as chloroform, chlorine dioxide is an attractive alternative to chlorine for drinking water disinfection. There are, however, concerns about its acute toxicity, and the toxic effects of its by-products, chlorite and chlorate. The human experience with chlorine dioxide in both controlled, prospective studies and in actual use situations in community water supplies have as yet failed to reveal adverse health effects. The EPA has recommended standards of 0.06 mg/L for chlorine dioxide and standards of 0.007 mg/L for chlorite and chlorate in drinking water. Among groups who may be at special risk from oxychlorines in drinking water are patients who must undergro chronic extracorporeal hemodialysis. Although even units for home hemodialysis are supposed to be equipped with devices which effectively remove oxychlorines, there is a always a possibility of operator error or equipment failure. When the equipment is adequately maintained, it is likely that dialysis patients will have more intensive exposures from drinking water than from dialysis fluids despite the much larger volumes of water that are involved in dialysis. This paper discusses a hemodialysis and the standards and effects of oxychlorines. 90 refs., 2 tabs.

  11. 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.

  12. Ex-situ bioremediation of polycyclic aromatic hydrocarbons in sewage sludge

    DEFF Research Database (Denmark)

    Larsen, Sille Bendix; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAH) are regarded as environmental pollutants. A promising approach to reduce PAH pollution is based on the implementation of the natural potential of some microorganisms to utilize hydrocarbons. In this study Proteiniphilum acetatigenes was used for bioaugmentat...

  13. Formation of halogenated organic byproducts during medium-pressure UV and chlorine coexposure of model compounds, NOM and bromide.

    Science.gov (United States)

    Zhao, Quan; Shang, Chii; Zhang, Xiangru; Ding, Guoyu; Yang, Xin

    2011-12-01

    When chlorine is applied before or during UV disinfection of bromide-containing water, interactions between chlorine, bromide and UV light are inevitable. Formation of halogenated organic byproducts was studied during medium-pressure UV (MPUV) and chlorine coexposure of phenol, nitrobenzene and benzoic acid and maleic acid, chosen to represent electron-donating aromatics, electron-withdrawing aromatics, and aliphatic structures in natural organic matter (NOM), respectively. All were evaluated in the presence and absence of bromide. MPUV and chlorine coexposure of phenol produced less total organic halogen (TOX, a collective parameter for halogenated organic byproducts) than chlorination in the dark, and more haloacetic acids instead of halophenols. Increases in TOX were found in the coexposure of nitrobenzene and benzoic acid, but maleic acid was rather inert during coexposure. The presence of bromide increased the formation of brominated TOX but did not significantly affect total TOX formation, in spite of the fact that it reduced hydroxyl radical levels. MPUV and chlorine coexposure of NOM gave a higher differential UV absorbance of NOM and a larger shift to lower molecular weight compounds than chlorination in the dark. However, TOX formation with NOM remained similar to that observed from dark chlorination.

  14. [Comparison of the quality and toxicity of wastewater after chlorine and chlorine dioxide disinfections].

    Science.gov (United States)

    Wang, Li-sha; Zhang, Tong; Hu, Hong-ying

    2005-11-01

    The effects of chlorine and chlorine dioxide disinfections on quality and toxicity of wastewater were compared. The experiment results showed that chlorine disinfection had no obvious effect on wastewater color, while chlorine dioxide disinfection decreased wastewater color observably. The DOC of wastewater did not change much after chlorine and chlorine dioxide disinfections. Chlorine disinfection significantly increased UV230 of wastewater and chlorine dioxide disinfection slightly decreased UV230 of wastewater. When the disinfectants dosage was 30 mg/L, UV230 increased about 0.7 cm(-1) after chlorine disinfection and decreased about 0.05 cm(-1) after chlorine dioxide disinfection. The acute toxicity of wastewater increased with increasing disinfectants dosage for both chlorine and chlorine dioxide disinfections and the acute toxicity after chlorine disinfection is much stronger than that after chlorine dioxide disinfection. The genotoxicity of wastewater increased slightly after chlorine disinfection and decreased slightly after chlorine dioxide disinfection.

  15. Why Does 2,3,5,6-Tetrachlorophenol Generate the Strongest Intrinsic Chemiluminescence among All Nineteen Chlorophenolic Persistent Organic Pollutants during Environmentally-friendly Advanced Oxidation Process?

    Science.gov (United States)

    Gao, Hui-Ying; Mao, Li; Shao, Bo; Huang, Chun-Hua; Zhu, Ben-Zhan

    2016-10-01

    We found recently that intrinsic chemiluminescence (CL) could be produced by all 19 chlorophenolic persistent organic pollutants during environmentally-friendly advanced oxidation processes. Interestingly and unexpectedly, the strongest CL was produced not by the most-highly chlorinated pentachlorophenol (PCP), but rather by the less chlorinated 2,3,5,6-tetrachlorophenol (2,3,5,6-TeCP), one of the three tetrachlorophenol (TeCPs) isomers. However, it remains unclear what is the underlying molecular mechanism. Here we show that not only chlorinated quinoid intermediates, but more interestingly, semiquinone radicals were produced during the degradation of the three TeCPs and PCP by Fenton reagents, and the type and yield of which were found to be well correlated with CL generation. We propose that hydroxyl radical-dependent formation of more tetrachlorinated quinoids, quinone-dioxetanes and electronically excited carbonyl species might be responsible for the exceptionally strong CL production by 2,3,5,6-TeCP as compared to PCP and its two isomers. This is the first report showing the critical role of quinoid intermediates and semiquinone radicals in CL generation from polychlorinated phenols and Fenton system. These new findings may have broad chemical and environmental implications for future studies on remediation of other halogenated persistent aromatic pollutants by advanced oxidation processes.

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

    OpenAIRE

    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 ...

  17. Electrochemical decomposition of chlorinated hydrocarbons

    OpenAIRE

    McGee, Gerard Anthony

    1993-01-01

    This work involves the characterisation of the electrochemical decomposition of chlorinated hydrocarbons. A variety of methods were employed involving the use of catalytic reagents to enhance the rate at which chlorinated organic compounds are reduced. The first reagent used was oxygen which was electrochemically reduced to superoxide in nonaqueous solvents. Superoxide is a reactive intermediate and decomposes chlorinated hydrocarbons. However it was found that since the rate of reaction betw...

  18. Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons

    NARCIS (Netherlands)

    Atashgahi, S.; Maphosa, F.; Vrieze, de J.; Haest, P.J.; Boon, N.; Smidt, H.; Springael, D.; Dejonghe, W.

    2014-01-01

    In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that

  19. Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons

    NARCIS (Netherlands)

    Atashgahi, S.; Maphosa, F.; Vrieze, de J.; Haest, P.J.; Boon, N.; Smidt, H.; Springael, D.; Dejonghe, W.

    2014-01-01

    In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that

  20. Molecular size distribution of dissolved organic matter in water of the Pearl River and trihalomethane formation characteristics with chlorine and chlorine dioxide treatments.

    Science.gov (United States)

    Zhao, Zhen-Ye; Gu, Ji-Dong; Fan, Xiao-Jun; Li, Hai-Bo

    2006-06-30

    River water sample was collected from Guangzhou section of the Pearl River to investigate soluble organic fractions and formation of trihalomethane (THMs) after chlorine and chlorine dioxide treatments. The water sample was passed through Amicon YC-05, YM-1, YM-3, YM-10, YM-30, YM-100 and ZM-500 series membranes after a pre-treatment. The molecular weight distribution and the specific ultra-violet absorbance (SUVA(254)) of each fraction obtained from membrane were analyzed, and these fractions were further disinfected with chlorine and chlorine dioxide. The results showed that reverse osmosis (RO) fraction contained mainly dissolved organic matter (DOM) from the water sample, suggesting that the water has been highly contaminated by anthropogenic activities. Meanwhile, the THMs concentration and SUVA(254) increased gradually as the molecular weight of the obtained fractions reduced, indicating that the low molecular weight DOM was the major THMs precursor in the disinfection process with chlorine and chlorine dioxide. The results suggest that THMs in source water of Pearl River could be effectively reduced when pollution of human activity is greatly controlled. Between the two disinfection processes tested, chlorine dioxide produced less THMs than chlorine in this study.

  1. A comparison of chlorinated organic material produced by chlorine and chlorine dioxide bleaching

    Energy Technology Data Exchange (ETDEWEB)

    McKaque, A.B.; Reeve, D.W. [Univ. of Toronto (Canada)

    1995-12-31

    Chlorine and chlorine dioxide react differently with pulp during bleaching and produce different types of organic by-products. The main differences are the large reduction in the amount of AOX (adsorbable organic halogen) in the effluent and EOX (extractable organic halogen) in the pulp. This talk reviews the differences in the amounts and types of chlorinated organic by-products produced by the two different bleaching agents.

  2. 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

  3. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    Energy Technology Data Exchange (ETDEWEB)

    Vacchi, Francine Inforcato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil); Ormond, Alexandra B.; Freeman, Harold S. [Department of Textile Engineering, Chemistry, and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Zocolo, Guilherme Juliao; Zanoni, Maria Valnice Boldrin [Departamento de Quimica Analitica, Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Quimica de Araraquara, Araraquara, SP 14801-970 (Brazil); Umbuzeiro, Gisela, E-mail: giselau@ft.unicamp.br [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil)

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: Black-Right-Pointing-Pointer Aqueous solutions of Disperse Red 1 were treated with chlorine. Black-Right-Pointing-Pointer The chlorination products of Disperse Red 1 were identified using LC-ESI-MS/MS. Black-Right-Pointing-Pointer Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. Black-Right-Pointing-Pointer The chlorinated dye was more mutagenic

  4. Fungal Unspecific Peroxygenases Oxidize the Majority of Organic EPA Priority Pollutants

    Directory of Open Access Journals (Sweden)

    Alexander Karich

    2017-08-01

    Full Text Available Unspecific peroxygenases (UPOs are secreted fungal enzymes with promiscuity for oxygen transfer and oxidation reactions. Functionally, they represent hybrids of P450 monooxygenases and heme peroxidases; phylogenetically they belong to the family of heme-thiolate peroxidases. Two UPOs from the basidiomycetous fungi Agrocybe aegerita (AaeUPO and Marasmius rotula (MroUPO converted 35 out of 40 compounds listed as EPA priority pollutants, including chlorinated benzenes and their derivatives, halogenated biphenyl ethers, nitroaromatic compounds, polycyclic aromatic hydrocarbons (PAHs and phthalic acid derivatives. These oxygenations and oxidations resulted in diverse products and—if at all—were limited for three reasons: (i steric hindrance caused by multiple substitutions or bulkiness of the compound as such (e.g., hexachlorobenzene or large PAHs, (ii strong inactivation of aromatic rings (e.g., nitrobenzene, and (iii low water solubility (e.g., complex arenes. The general outcome of our study is that UPOs can be considered as extracellular counterparts of intracellular monooxygenases, both with respect to catalyzed reactions and catalytic versatility. Therefore, they should be taken into consideration as a relevant biocatalytic detoxification and biodegradation tool used by fungi when confronted with toxins, xenobiotics and pollutants in their natural environments.

  5. 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.

  6. Inactivation of Chironomid Larvae with Chlorine Dioxide and Chlorine

    Institute of Scientific and Technical Information of China (English)

    SUN Xin-bin; CUI Fu-yi

    2008-01-01

    Chironomid larvae propagate prolifically in eutrophic water body and they cannot be exterminated by conventional disinfection process.The inactivation effects of chlorine and chlorine dioxide on Chironomid larvae were investigated and some boundary values in practice were determined under conditions of various oxidant dosage,organic precursor concentration and pH value.In addition,removal effect of differmt pre-oxidation combined with coagulation process on Chironomid larvae in law water was evaluated.It was found that chlorine dioxide possessed better inactivation effect than chlorine.Complete inactivation of Chironomid larvae in raw water was resulted by 1.5mg/L of chlorine dioxide with 30min of contact time. Additionally,the ocgallic precursor concentration,pH value had little influence on the inactivation effect.The coagulation jar test showed that Chironomid larvae in the raw water could be completely ronxwed by chlorine dioxide pre-oxidation in combination with the omgulation process at chlorine dioxide dosage of 0.8 mg/L.

  7. Degradation of natural organic matter by UV/chlorine oxidation: Molecular decomposition, formation of oxidation byproducts and cytotoxicity.

    Science.gov (United States)

    Wang, Wen-Long; Zhang, Xue; Wu, Qian-Yuan; Du, Ye; Hu, Hong-Ying

    2017-11-01

    The degradation of natural organic matters (NOMs) by the combination of UV and chlorine (UV/chlorine) was investigated in this study. UV/chlorine oxidation can effectively degrade NOMs, with the degradation of chromophores (∼80%) and fluorophores (76.4-80.8%) being more efficient than that of DOC (15.1-18.6%). This effect was attributed to the chromophores and fluorophores (double bonds, aromatic groups and phenolic groups) being preferentially degraded by UV/chlorine oxidation, particularly reactive groups with high electron donating capacity. Radical species •OH and •Cl were generated during UV/chlorine oxidation, with the contribution of •OH 1.4 times as high as that of •Cl. The degradation kinetics of different molecular weight (MW) fractions suggests that UV/chlorine oxidation degrades high MW fractions into low MW fractions, with the degradation rates of high MW fractions (>3000 Da) 4.5 times of those of medium MW fractions (1000-3000 Da). In comparison with chlorination alone, UV/chlorine oxidation did not increase the formation (30 min) and formation potential (24 h) of trihalomethanes, but instead promoted the formation and formation potential of haloacetic acids and chloral hydrate. Adsorbable organic halogen (AOX) formed from UV/chlorine oxidation of NOM were 0.8 times higher than those formed from chlorination. Cytotoxicity studies indicated that the cytotoxicity of NOM increased after both chlorination and UV/chlorine oxidation, which may be due to the formation of AOX. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. ELECTROCHEMICAL DEGRADATION OF PERSISTANCE POLLUTANTS IN GROUNDWATER AND SEDIMENTS

    Science.gov (United States)

    Electrochemical Degradation (ECD) utilizes redox potential at the anode and the cathode to oxidize and/or reduce organic contaminants. ECD of environmentally persistence pollutants such chlorinate solvents, PCBs, and PAHs, although theoretically possible, has not been experimenta...

  9. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry.

    Science.gov (United States)

    Wang, Xin; Wang, Juan; Zhang, Yahe; Shi, Quan; Zhang, Haifeng; Zhang, Yu; Yang, Min

    2016-06-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AImod), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water.

  10. Recent analytical methods for atmospheric polycyclic aromatic hydrocarbons and their derivatives.

    Science.gov (United States)

    Hayakawa, Kazuichi; Tang, Ning; Toriba, Akira

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are ubiquitous environmental pollutants. Moreover, some oxidative metabolites of these pollutants, such as hydroxylated and epoxide PAHs, cause endocrine disruption or produce reactive oxygen species. These compounds have become a large concern from the viewpoint of particulate matter (PM2.5 ) pollution. This report deals with recent studies concerning analytical methods for PAHs, NPAHs and related compounds in atmospheric and biological samples.

  11. Influence of organic pollutants in source water on formation of chlorinated disinfection byproducts in drinking water%源水中有机污染物对饮用水氯化消毒副产物形成的影响研究

    Institute of Scientific and Technical Information of China (English)

    李谦; 樊文明; 黄伟; 梅玉琴; 廖青; 刘天洁

    2013-01-01

    Objective:To discuss the influence of organic pollutants in source water on the formation of chlorinated disinfection byproducts in drinking water.Methods:Trihalomethanes,haloacetic acids and potassium permanganate oxygen consumption in finished water and peripheral water of the 36 waterworks in Zigong were determined by gas chromatograph and colorimeter.Results:The disinfection byproducts were detected in defferent degrees in all of the 36 waterworks.Conclusion:The influencing factors of disinfection byproducts in water were consisted of the type of source water and organic pollution,the disinfection byproducts increased in the water of river and the source water with high oxygen consumption.%目的:研究源水中有机物污染对饮用水中氯化消毒副产物形成的影响.方法:采用安捷伦7890A气相色谱仪、ECD检测器,对自贡市36家自来水厂出厂水管网末梢水中的三卤甲烷、卤乙酸、高锰酸钾耗氧量进行测定.结果:36家自来水厂的出厂水管网末梢水不同程度检出氯化消毒副产物三卤甲烷(三氯甲烷、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷),卤乙酸(二氯乙酸、三氯乙酸).结论:水源水种类、有机物污染是影响消毒副产物生成的因素,江河水、耗氧量高的源水消毒副产物较多.

  12. Reactions of Chlorine Gas on Benzaldehyde-di-n-alkyl Acetals

    Directory of Open Access Journals (Sweden)

    A. Edwin Vasu

    2008-01-01

    Full Text Available Reactions of chlorine gas on six aromatic acetals, the benzaldehyde di-n-alkyl acetals, C6H4-CH(OR2 where R=ethyl (1a, n-propyl (2a, n-butyl (3a, isobutyl (4a, n-amyl (5a and isoamyl (6a were studied. The products were analyzed by IR and 1H NMR spectroscopic techniques and were found to be ring chlorinated alkyl benzoates. A plausible mechanism has been proposed based on the experimental observations and the effect of the alkyl groups on the product yield.

  13. Gaseous, chlorine-free chlorine dioxide for drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, G. [Miami Univ., Oxford, OH (United States); Rosenblatt, A. [CDG Technology Inc., New York, NY (United States)

    1996-11-01

    The benefits of applying chlorine dioxide (ClO{sub 2}) for the oxidative treatment of drinking water are well established. Chlorine dioxide treated finished water typically has substantially lower trihalomethane (THM) levels because ClO{sub 2} will not form chlorinated organic species as a by-product of disinfection. The THMs that are formed are probably due to chlorine from the generator or chlorine used to maintain a post-disinfection residual. An emerging regulatory issue concerning the formation of disinfection by-products (DBPs) is causing the water industry to set standards for the generation and delivery of ClO{sub 2}. The Federal Register (11 February 1994) contains language developed to limit the production of the unwanted inorganic by-products chlorite (ClO{sub 2}{sup -}), chlorate (ClO{sub 3}{sup -}), and bromate (BrO{sub 3}{sup -}) ions by requiring utilities to maintain high (95%) generation efficiencies and by limiting the amount of excess Cl{sub 2} that can be used during the generation process. The efficiency and excess Cl{sub 2} regulations may be problematic for utilities that over-chlorinate to attain chlorine dioxide high yields. Many utilities will have to decide either to reduce the amount of Cl{sub 2} used to react with sodium chlorite (NaClO{sub 2}), thereby increasing the ClO{sub 2}{sup -} residual in finished water, or over-chlorinate to increase yields and surpass the excess Cl{sub 2} limits.

  14. Improved method generates more chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, R.W.; Kosinski, A.J.; Baker, R.J.

    1980-10-01

    The addition of acid can greatly improve the chlorine-chlorite process and enhance the use of chlorine dioxide as an alternative to chlorine for disinfection. The process is economical for use in taste and odor control, and for manganese, oxidation. The maximum yield is obtained using no excess chlorine, and the amount of unreacted sodium chlorite and chlorine in the product stream is reduced. (1 diagram, 4 graphs, 9 references)

  15. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  16. Biodegradation Rates of Aromatic Contaminants in Biofilm Reactors

    DEFF Research Database (Denmark)

    Arcangeli, Jean-Pierre; Arvin, Erik

    1995-01-01

    This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols, chlorophe......This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols......-reducing conditions, toluene was easily biodegraded. The xylenes and ethylbenzene were degraded cometabolically if toluene was used as a primary carbon source; their removal was influenced by competitive inhibition with toluene. These interaction phenomena are discussed in this paper and a kinetic model taking...

  17. 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....

  18. 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....

  19. A DFT study of the interaction between large PAHs and atomic chlorine or hydrogen chloride molecule: Toward a modelling of the influence of chlorinated species on the trapping of water by soot

    Science.gov (United States)

    Garcia-Fernandez, C.; Radola, B.; Martin-Gondre, L.; Picaud, S.; Rayez, M. T.; Rayez, J. C.; Ouf, F. X.; Rubayo-Soneira, J.

    2017-02-01

    First-principle calculations have been performed to characterize the interaction of chlorinated species (HCl and Cl) with large polycyclic aromatic hydrocarbon (PAH) molecules and radicals. Whereas the characterization of the interaction process on the face of the PAH molecules requires taking into account long-range dispersion interactions in the calculations, trapping at the edge of PAH radicals involves stronger interactions that lead to the dissociation of the HCl molecule. Then, the first steps of water adsorption on the corresponding chlorinated species has been characterized, showing that chlorine may act as an efficient nucleation center for water molecules on such aromatic systems mimicking part of the carbonaceous surfaces that are likely present in soot. These results represent a first but necessary step for a better understanding of soot behavior in industrial or domestic fire situations.

  20. Transformation of iopamidol during chlorination.

    Science.gov (United States)

    Wendel, Friedrich M; Lütke Eversloh, Christian; Machek, Edward J; Duirk, Stephen E; Plewa, Michael J; Richardson, Susan D; Ternes, Thomas A

    2014-11-01

    The transformation of the iodinated X-ray contrast media (ICM) iopamidol, iopromide, iohexol, iomeprol, and diatrizoate was examined in purified water over the pH range from 6.5 to 8.5 in the presence of sodium hypochlorite, monochloramine, and chlorine dioxide. In the presence of aqueous chlorine, only iopamidol was transformed. All other ICM did not show significant reactivity, regardless of the oxidant used. Chlorination of iopamidol followed a second order reaction, with an observed rate constant of up to 0.87 M(-1) s(-1) (±0.021 M(-1) s(-1)) at pH 8.5. The hypochlorite anion was identified to be the reactive chlorine species. Iodine was released during the transformation of iopamidol, and was mainly oxidized to iodate. Only a small percentage (less than 2% after 24 h) was transformed to known organic iodinated disinfection byproducts (DBPs) of low molecular weight. Some of the iodine was still present in high-molecular weight DBPs. The chemical structures of these DBPs were elucidated via MSn fragmentation and NMR. Side chain cleavage was observed as well as the exchange of iodine by chlorine. An overall transformation pathway was proposed for the degradation of iopamidol. CHO cell chronic cytotoxicity tests indicate that chlorination of iopamidol generates a toxic mixture of high molecular weight DBPs (LC50 332 ng/μL).

  1. Chlorination of Pyridinium Compounds

    Science.gov (United States)

    Daumer, Kathleen M.; Khan, Ahsan U.; Steinbeck, Marla J.

    2010-01-01

    Reactive oxygen species produced by activated neutrophils and monocytes are thought to be involved in mediating the loss of collagen and other matrix proteins at sites of inflammation. To evaluate their potential to oxidize the pyridinoline (Pyd) cross-links found in collagen types I and II, we reacted hydrogen peroxide (H2O2), hypochlorous acid/hypochlorite (HOCl/OCl−), and singlet oxygen (O2(1Δg)) with the Pyd substitutes, pyridoxamine dihydrochloride and vitamin B6, which share the same chemical structure and spectral properties of Pyd cross-links. Neither H2O2 (125–500 µm) nor O2(1Δg) (10–25 µm) significantly changed the spectral properties of pyridoxamine or vitamin B6. Reaction of HOCl/OCl− (12.5–50 µm) with pyridoxamine at pH 7.2 resulted in a concentration-dependent appearance of two new absorbance peaks and a decrease in fluorescence at 400 nm (excitation 325 nm). The new absorbance peaks correlated with the formation of an N-chloramine and the product of its subsequent reaction with pyridoxamine. In contrast, the extent to which HOCl reacted with vitamin B6, which lacks a primary amine group, was variable at this pH. At lysosomal pH 5.5, Cl2/HOCl/OCl− reacted with both pyridoxamine and vitamin B6. Four of the chlorinated products of this reaction were identified by gas chromatography-mass spectrometry and included 3-chloropyridinium, an aldehyde, and several chlorinated products with disrupted rings. To evaluate the effects of Cl2/HOCl/OCl− on Pyd cross-links in collagen, we exposed bone collagen type I and articular cartilage type II to HOCl. Treatment of either collagen type with HOCl at pH 5.0 or 7.2 resulted in the oxidation of amine groups and, for collagen type II, the specific decrease in Pyd cross-link fluorescence, suggesting that during inflammation both oxidations may be used by neutrophils and monocytes to promote the loss of matrix integrity. PMID:10940296

  2. In situ aerobic cometabolism of chlorinated solvents: a review.

    Science.gov (United States)

    Frascari, Dario; Zanaroli, Giulio; Danko, Anthony S

    2015-01-01

    The possible approaches for in situ aerobic cometabolism of aquifers and vadose zones contaminated by chlorinated solvents are critically evaluated. Bioaugmentation of resting-cells previously grown in a fermenter and in-well addition of oxygen and growth substrate appear to be the most promising approaches for aquifer bioremediation. Other solutions involving the sparging of air lead to satisfactory pollutant removals, but must be integrated by the extraction and subsequent treatment of vapors to avoid the dispersion of volatile chlorinated solvents in the atmosphere. Cometabolic bioventing is the only possible approach for the aerobic cometabolic bioremediation of the vadose zone. The examined studies indicate that in situ aerobic cometabolism leads to the biodegradation of a wide range of chlorinated solvents within remediation times that vary between 1 and 17 months. Numerous studies include a simulation of the experimental field data. The modeling of the process attained a high reliability, and represents a crucial tool for the elaboration of field data obtained in pilot tests and for the design of the full-scale systems. Further research is needed to attain higher concentrations of chlorinated solvent degrading microbes and more reliable cost estimates. Lastly, a procedure for the design of full-scale in situ aerobic cometabolic bioremediation processes is proposed.

  3. Cleaning without chlorinated solvents

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.M.; Simandl, R.F.

    1994-12-31

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

  4. Aromater i drikkevand

    DEFF Research Database (Denmark)

    Nyeland, B. A.; Hansen, A. B.

    DMU har den 10. Juni 1997 afholdt en præstationsprøvning: Aromater i drikkevand. Der deltog 21 laboratorier i præstationsprøvningen. Prøvningen omfattede 6 vandige prøver og 6 ampuller indeholdende 6 aromater. Laboratorierne spikede de tilsendte vandprøver med indholdet fra ampullerne...

  5. Biomarkers of genotoxicity of urban air pollution. Overview and descriptive data from a molecular epidemiology study on populations exposed to moderate-to-low levels of polycyclic aromatic hydrocarbons: the AULIS project

    DEFF Research Database (Denmark)

    Kyrtopoulos, S.A.; Georgiadis, P.; Autrup, H.

    2001-01-01

    inconclusive results, partly because of the absence of adequate data on personal exposure, covering a time-window which is appropriate for the biomarkers being examined, as well as a battery of biomarkers reflecting different stages of the carcinogenic process. In the present paper, the potential of biomarker......-bound polycyclic aromatic hydrocarbons (PAHs), no simple correlation with biomarkers of genotoxicity existed and suggest that additional factors made a significant contribution to the overall genotoxic burden....

  6. 短链氯化石蜡及其环境污染现状与毒性效应研究%THE RESEARCH OF ENVIRONMENTAL POLLUTIONS AND TOXIC EFFECT OF SHORT CHAIN CHLORINATED PARAFFINS

    Institute of Scientific and Technical Information of China (English)

    王亚(韦华); 傅建捷; 江桂斌

    2009-01-01

    短链氯化石蜡是碳链长度为10至13个碳原子的正构烷烃经氯化衍生而成的复杂混合物.作为增列持久性有机污染物(persistent organic pollutants,POPs)中的一类化合物,2008年10月在瑞典日内瓦召开的联合国环境规划署POPs审查委员会的第四次会议上,委员会对短链氯化石蜡进行了公约附件E关于其终点的危害评估进行了审核.而目前我国对短链氯化石蜡没有任何关于毒性研究和环境污染现状的数据,本文针对短链氯化石蜡的研究现状、进展及目前存在的问题进行了总结,以便为我国在此方面开展研究提供参考.

  7. Advances of Application of Stationary Phases to GC Separation of Polycyclic Aromatic Compounds in Environmental Pollutants%气相色谱分离多环芳香环境污染物用固定相的应用进展

    Institute of Scientific and Technical Information of China (English)

    滕爽; 吴波; 高尧华; 牛妍妍

    2012-01-01

    A review on application of various kinds of stationary phases in the GC separation of environmental pollutants,[including polycyclic aromatic hydrocarbons(PAHs),polycyclic aromatic compounds(PACs) and polychlorinated biphenyls(PCBs)] was reported.The main kinds of stationary phases were listed such as polysiloxane,liquid crystal,crown ether,cyclodextrin,ionic liquids and fibrous.A forecast for the future application of these stationary phases was also given(64 ref.cited).%综述了几种气相色谱固定相包括聚硅氧烷、液晶、冠醚、环糊精、离子液体及纤维填充固定相,在分离多环芳香烃(PAHs)、多环芳香化合物(PACs)及多氯联苯(PCBs)等环境污染物中的应用进展,展望了此类固定相的应用前景(引用文献64篇)。

  8. Effect of odd hydrogen on ozone depletion by chlorine reactions

    Science.gov (United States)

    Donahue, T. M.; Cicerone, R. J.; Liu, S. C.; Chameides, W. L.

    1976-01-01

    The present paper discusses how the shape of the ozone layer changes under the influence of injected ClX for several choices of two key HOx reaction rates. The two HOx reactions are: OH + HO2 yields H2O + O2 and O + HO2 yields OH + O2. Results of calculations are presented which show that the two reaction rates determine the stratospheric concentrations of OH and HO2, and that these concentrations regulate the amount by which the stratospheric ozone column can be reduced due to injections of odd chlorine. It is concluded that the amount of ozone reduction by a given mixing ratio of ClX will remain very uncertain until the significance of several possible feedback effects involving HOx in a chlorine-polluted atmosphere are determined and measurements of the reaction rates and HOx concentrations are made at the relevant temperatures.

  9. Enzymatic chlorination and bromination.

    Science.gov (United States)

    van Pée, Karl-Heinz

    2012-01-01

    Our knowledge about the enzymes catalyzing the incorporation of halide ions during the biosynthesis of halometabolites has increased tremendously during the last 15 years. Between 1960 and 1995, haloperoxidases were the only halogenating enzymes known. However, absolute proof for the connection of haloperoxidases to the biosynthesis of halometabolites is still missing. In 1997, FADH(2)-dependent halogenases were identified as the type of halogenating enzymes responsible for the incorporation of chloride and bromide atoms into aromatic and aliphatic compounds activated for electrophilic attack. FADH(2)-dependent halogenases are two-component systems consisting of a flavin reductase providing the FADH(2) required by the halogenase. Elucidation of the three-dimensional structure of FADH(2)-dependent halogenases led to the understanding of the reaction mechanism, which involves the formation of hypohalous acids. Unactivated carbon atoms were found to be halogenated by nonheme iron, α-ketoglutarate- and O(2)-dependent halogenases. The reaction mechanism of this type of halogenase was shown to involve the formation of a substrate radical. These two types of halogenating enzymes, together with the much less common fluorinases, are the major types of halogenating enzymes. However, the existence of other types of halogenating enzymes, yet not detected, cannot be completely ruled out. Here, we describe the detection, purification, characterization, and reaction mechanisms of flavin-dependent halogenases and of nonheme iron, α-ketoglutarate- and O(2)-dependent halogenases.

  10. Pollutant Types

    Science.gov (United States)

    Describes the types of air pollutants, including common or criteria pollutants, and hazardous air pollutants and links to additional information. Also links to resources on other air pollution issues.

  11. 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

  12. Aromatic VOCs global influence in the ozone production

    Science.gov (United States)

    Cabrera-Perez, David; Pozzer, Andrea

    2016-04-01

    Aromatic hydrocarbons are a subgroup of Volatile Organic Compounds (VOCs) of special interest in the atmosphere of urban and semi-urban areas. Aromatics form a high fraction of VOCs, are highly reactive and upon oxidation they are an important source of ozone. These group of VOCs are released to the atmosphere by processes related to biomass burning and fossil fuel consumption, while they are removed from the atmosphere primarily by OH reaction and by dry deposition. In addition, a branch of aromatics (ortho-nitrophenols) produce HONO upon photolysis, which is responsible of certain amount of the OH recycling. Despite their importance in the atmosphere in anthropogenic polluted areas, the influence of aromatics in the ozone production remains largely unknown. This is of particular relevance, being ozone a pollutant with severe side effects on air quality, health and climate. In this work the atmospheric impacts at global scale of the most emitted aromatic VOCs in the gas phase (benzene, toluene, xylenes, ethylbenzene, styrene, phenol, benzaldehyde and trimethylbenzenes) are analysed and assessed. Specifically, the impact on ozone due to aromatic oxidation is estimated, as this is of great interest in large urban areas and can be helpful for developing air pollution control strategies. Further targets are the quantification of the NOx loss and the OH recycling due to aromatic oxidation. In order to investigate these processes, two simulations were performed with the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The simulations compare two cases, one with ozone concentrations when aromatics are present or the second one when they are missing. Finally, model simulated ozone is compared against a global set of observations in order to better constrain the model accuracy.

  13. Colorectal cancers and chlorinated water

    Institute of Scientific and Technical Information of China (English)

    Ahmed Mahmoud El-Tawil

    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 concentrations of calcium, magnesium and iron in the public drinking water and prescribing oestrogen in susceptible individuals. Hypo-methylation of genomic DNA could be used as a biological marker for screening for the potential development of colorectal cancers.

  14. Increased formation of halomethanes during chlorination of chloramphenicol in drinking water by UV irradiation, persulfate oxidation, and combined UV/persulfate pre-treatments.

    Science.gov (United States)

    Wenhai, Chu; Tengfei, Chu; Erdeng, Du; Deng, Yang; Yingqing, Guo; Naiyun, Gao

    2016-02-01

    Ultraviolet/persulfate (UV/PS) has been widely used to generate sulfate radicals for degradation of water organic pollutants in previous studies. However, its impacts on disinfection byproduct formation during post-chlorination of degraded compounds is unclear. The objective of this study was to evaluate the impacts of UV irradiation, PS oxidation, and the combined UV/PS advanced oxidation process (AOP) pre-treatments on halomethane formation during the following chlorination of chloramphenicol (CAP), a model antibiotic commonly found in wastewater-impacted water. Results showed that CAP could be transformed to more trichloromethane (TCM) than monochloromethane (MCM) and dichloromethane (DCM) in the presence of excess chlorine. UV photolysis, PS oxidation and UV/PS AOP all directly decomposed CAP to produce halomethanes (HMs) before post-chlorination. Moreover, UV and UV/PS pre-treatments both enhanced the formation of all the HMs in the subsequent chlorination. PS pre-oxidation decreased the TCM formation during post-chlorination, but increased the yields of MCM, DCM and total HMs. UV pre-irradiation significantly increased the bromide utilization of HMs, whereas UV/PS pre-oxidation decreased the bromine incorporation and utilization of HMs from the chlorination of CAP in a low-bromide water. UV irradiation, PS oxidation, and UV/PS AOP can inactivate pathogens and degrade organic pollutants, but this benefit should be weighed against a potential risk of the increased halomethane formation from degraded organic pollutants with and without post-chlorination.

  15. Ex-situ bioremediation of polycyclic aromatic hydrocarbons in sewage sludge

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Larsen, S.B.; Karakashev, Dimitar Borisov

    2008-01-01

    Polycyclic aromatic hydrocarbons (PAH) are naturally occurring organic compounds. As a result of anthropogenic activities, PAH concentration has increased in the environment considerably. PAH are regarded as environmental pollutants because they have toxic, mutagenic and carcinogenic effects on l...

  16. Characterization of aerobic polycyclic aromatic hydrocarbon‐degrading bacteria from Bizerte lagoon sediments, Tunisia

    National Research Council Canada - National Science Library

    Ben Said, O; Goñi‐Urriza, M.S; El Bour, M; Dellali, M; Aissa, P; Duran, R

    2008-01-01

    Aims:  To characterize polycyclic aromatic hydrocarbon (PAH)‐degrading bacteria from sediments of the Bizerte lagoon, and to determine their ability to resist other pollutants such as antibiotics and heavy metals...

  17. High Speed Liquid Chromatographic Determination of Total Aromatics in Enamel and Lacquer Solvents.

    Science.gov (United States)

    Esposito, G. G.

    Aromatic solvents possess the strongest solvency of the hydrogen types, but various air pollution control districts have established maximum limits on the amount that may be present in organic coatings. In the proposed procedure, high efficiency liquid chromatography is used to determine total aromatics in enamels and lacquer thinners, their…

  18. High Speed Liquid Chromatographic Determination of Total Aromatics in Enamel and Lacquer Solvents.

    Science.gov (United States)

    Esposito, G. G.

    Aromatic solvents possess the strongest solvency of the hydrogen types, but various air pollution control districts have established maximum limits on the amount that may be present in organic coatings. In the proposed procedure, high efficiency liquid chromatography is used to determine total aromatics in enamels and lacquer thinners, their…

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

    OpenAIRE

    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% inactiv...

  20. Disinfectants: Chlorine and chlorine dioxide. (Latest citations from the Life Sciences Collection database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    The bibliography contains citations concerning the antimicrobial properties of chlorine and chlorine dioxide. The use of chlorine for the inactivation of viruses, bacteria, and fungi in wastewater treatment plants is discussed, including the mode of action and factors influencing inactivation. The use of chlorine dioxide as an alternative to chlorine disinfection in swimming pools and water supplies, and possible adverse effects are also discussed. (Contains a minimum of 157 citations and includes a subject term index and title list.)

  1. SHORT COMMUNICATION POLYCYCLIC AROMATIC ...

    African Journals Online (AJOL)

    a

    *Corresponding author. E-mail: omotayosharafdeen@yahoo.com ... The levels of isolated polycyclic aromatic hydrocarbons (PAH) in ash residues of .... PAH standards, PAH recoveries and percentage recoveries are given in Table 2. In all the ...

  2. Trimerization of aromatic nitriles

    Science.gov (United States)

    Hsu, L. C. (Inventor)

    1977-01-01

    Triazine compounds and cross-linked polymer compositions were made by heating aromatic nitriles to a temperature in the range of about 100 C to about 700 C, in the presence of a catalyst or mixture of catalysts. Aromatic nitrile-modified (terminated and/or appended) imide, benzimidazole, imidazopyrrolone, quinoxaline, and other condensation type prepolymers or their precopolymers were made which were trimerized with or without a filler by the aforementioned catalytic trimerization process.

  3. Pre-chlorination contact time and the removal and control of Microcystis aeroginosa in coagulation

    Science.gov (United States)

    Lapsongpon, T.; Leungprasert, S.; Yoshimura, C.

    2017-05-01

    The use of pre-oxidation is known to improve algae removal by coagulation and control the growth of algae. The contact time between oxidants and algae in pre-oxidation stage has been found as important parameter. This study investigated the effect of pre-chlorination contact time on the control and removal of cyanobacteria Microcystis aeruginosa by coagulation. The results showed that when the alum dose was sufficient, increasing contact time showed an improvement in algae removal by coagulation in case of high chlorine dose. The algae removal ratio at high chlorine dose, 3 mg L-1 increased when contact time increased and it decreased after 30 minutes of contact time. In contrast, the result from chlorine dose, 2 mg L-1, showed an unclear trend when contact time increased. Adding 2 mg L-1 of pre-chlorination with 10 minutes of contact time was enough to control the regrowth of M. aeruginosa. In addition, dissolve organic carbon (DOC) and UV absorbance at 254 nm, which particulary indicates aromatic compounds, tended to increase when the contact time increased. The increased of DOC and UV 254 indicated the release of intracellular organic matter (IOM) from M. aeruginosa. High level of DOC, 0.68 mg L-1 in this study showed negative effect on M. aeruginosa removal by coagulation and could not be removed by coagulation process.

  4. Atmospheric Chemistry and Air Pollution

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Gaffney

    2003-01-01

    Full Text Available Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozone and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.

  5. Combined toxicity effects of chlorine, ammonia, and temperature on marine plankton. Progress report, February 1, 1975--September 15, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.; Goldman, J. C.

    1975-10-01

    Research on the combined effects of chlorine, ammonia, and temperature on marine plankton have been carried out for 7/sup 1///sub 2/ months. Continuous-flow bioassay units have been constructed for larval species, juvenile fish, and phytoplankton. A detailed study on lobster (Homarus americanus) larvae and other studies on killifish (Fundulus heteroclitus) larvae and juveniles, and juvenile scup (Stenotomus versicolor) and winter flounder (Pseudopleuronectes americanus) have been performed. Results to date indicate that there is an apparent and, as yet undetermined, chlorine demand of seawater; there is a differential toxic effect of chlorine and chloramines--lobsters were more sensitive to chloramines, whereas the fish species were more affected by free chlorine; respiration results indicate that significant stress occurs at toxicant levels below the onset of mortality, thus raising questions regarding the applicability of standard bioassay data; temperature elevation exerts a strong synergistic effect on chlorine-chloramine toxicity; and effects of exposure to halogen toxicity appear irreversible as revealed by persistent reductions in metabolic activity. It appears that chlorine toxicity to marine biota can occur even though chlorine residuals cannot be detected by current analytical techniques. These results support the findings of others that chlorine toxicity is a serious environmental pollutant. (auth)

  6. Purification of highly chlorinated dioxins degrading enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, K.; Furuichi, T.; Koike, K.; Kuboshima, M. [Hokkaido Univ. (Japan). Division of Environment Resource Engineering, Graduate School of Engineering

    2004-09-15

    Soil contamination caused by dioxins in and around sites of incinerators for municipal solid waste (MSW) is a concern in Japan. For example, scattering wastewater from a wet gas scrubber at an MSW incinerator facility in Nose, Osaka caused soil and surface water contamination. The concentration of dioxins in the soil was about 8,000 pg-TEQ/g. Other contamination sites include soils on which fly ash has been placed directly or improperly stored and landfill sites that have received bottom and fly ash over a long period. Some countermeasures are required immediately at these dioxins-contaminated sites. We have previously developed bioreactor systems for dioxin-contaminated water and soil. We have shown that a fungus, Pseudallescheria boydii (P. boydii), isolated from activated sludge treating wastewater that contained dioxins, has the ability to degrade highly chlorinated dioxins. A reaction product of octachlorinated dibenzo-p-dioxin (OCDD) was identified as heptachlorinated dibenzo-p-dioxin. Therefore, one of the pathways for degradation of OCDD by this fungus was predicted to be as follows: OCDD is transformed by dechlorination and then one of the remaining aromatic rings is oxidized. To apply P. boydii to on-site technologies (e.g., bioreactor systems), as well as in situ technologies, enzyme treatment using a dioxin-degrading enzyme from P. boydii needs to be developed because P. boydii is a weak pathogenic fungus, known to cause opportunistic infection. As a result, we have studied enzyme purification of nonchlorinated dioxin, namely, dibenzo-pdioxin (DD). However, we did not try to identify enzymes capable of degrading highly chlorinated dioxins. This study has elucidated a method of enzyme assay for measuring OCDD-degrading activity, and has attempted to purify OCDD-degrading enzymes from P. boydii using enzyme assay. In addition, as first step toward purifying 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), 2,3,7,8-TCDD degradation tests were carried out

  7. Reactions of phenylurea compounds with aqueous chlorine: Implications for herbicide transformation during drinking water disinfection.

    Science.gov (United States)

    Chusaksri, Sarinma; Sutthivaiyakit, Somyote; Sedlak, David L; Sutthivaiyakit, Pakawadee

    2012-03-30

    Phenylurea herbicides have been known to contaminate surface waters serving as potable supplies. To access the potential for transformation of these compounds during drinking water treatment, reactions of phenylurea compounds with aqueous chlorine at different pHs were investigated. The effect of substitution at the amino-N on the rate of transformation depends upon pH. Under acidic conditions, all of the phenylurea studied except 3,4-dichloro-3'-N-methylphenylurea (3,4-DCMPU) exhibited third-order kinetics, second order with respect to chlorine and first order with respect to phenylurea, while the reactions of 3,4-DCMPU were first order with respect to both chlorine and the organic compound. Under neutral and alkaline conditions, all compounds exhibited second-order kinetics that was first order with respect to chlorine and the organic compound. Apparent second-order rate constants at 25°C and pH 7 were 0.76 ± 0.16, 0.52 ± 0.11, 0.39 ± 0.02, 0.27 ± 0.04 and 0.23 ± 0.05 M(-1)s(-1) for phenylurea, 3, 4-dichlorophenylurea, 3, 4-DCMPU, metoxuron and monuron, respectively. Studies of the chlorination products, monitored by LC/MS/MS, under different pH values indicated the reaction to take place at both N atoms and also at ortho- and para- positions of the phenylurea aromatic group. The main chlorinating species were found to be different in different pH ranges. Under conditions typically encountered in drinking water treatment systems, transformation of these compounds by chlorine will be incomplete.

  8. Environmental factors regulating soil organic matter chlorination

    Science.gov (United States)

    Svensson, Teresia; Montelius, Malin; Reyier, Henrik; Rietz, Karolina; Karlsson, Susanne; Lindberg, Cecilia; Andersson, Malin; Danielsson, Åsa; Bastviken, David

    2016-04-01

    Natural chlorination of organic matter is common in soils. Despite the widespread abundance of soil chlorinated soil organic matter (SOM), frequently exceeding soil chloride abundance in surface soils, and a common ability of microorganisms to produce chlorinated SOM, we lack fundamental knowledge about dominating processes and organisms responsible for the chlorination. To take one step towards resolving the terrestrial chlorine (Cl) puzzle, this study aims to analyse how environmental factors influence chlorination of SOM. Four factors were chosen for this study: soil moisture (W), nitrogen (N), chloride (Cl) and organic matter quality (C). These factors are all known to be important for soil processes. Laboratory incubations with 36Cl as a Cl tracer were performed in a two soil incubation experiments. It was found that addition of chloride and nitrogen seem to hamper the chlorination. For the C treatment, on the other hand, the results show that chlorination is enhanced by increased availability of labile organic matter (glucose and maltose). Even higher chlorination was observed when nitrogen and water were added in combination with labile organic matter. The effect that more labile organic matter strongly stimulated the chlorination rates was confirmed by the second separate experiment. These results indicate that chlorination was not primarily a way to cut refractory organic matter into digestible molecules, representing one previous hypothesis, but is related with microbial metabolism in other ways that will be further discussed in our presentation.

  9. Assessment of the spatial and temporal distribution of persistent organic pollutants (POPs) in the Nordic atmosphere

    Science.gov (United States)

    Anttila, Pia; Brorström-Lundén, Eva; Hansson, Katarina; Hakola, Hannele; Vestenius, Mika

    2016-09-01

    Long-term atmospheric monitoring data (1994-2011) of persistent organic pollutants (POPs) were assembled from a rural site in southern Sweden, Råö, and a remote, sub-Arctic site in Finland, Pallas. The concentration levels, congener profiles, seasonal and temporal trends, and projections were evaluated in order to assess the status of POPs in the Scandinavian atmosphere. Our data include atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), altogether comprising a selection of 27 different compounds. The atmospheric POP levels were generally higher in the south, closer to the sources (primary emissions) of the pollutants. The levels of low-chlorinated PCBs and chlordanes were equal at the two sites, and one of the studied POPs, α-HCH, showed higher levels in the north than in the south. Declining temporal trends in the atmospheric concentrations for the legacy POPs - PCBs (2-4% per year), HCHs (6-7% per year), chlordanes (3-4% per year) and DTTs (2-5% per year) - were identified both along Sweden's west coast and in the sub-Arctic area of northern Finland. Most of PAHs did not show any significant long-term trends. The future projections for POP concentrations suggest that in Scandinavia, low-chlorinated PCBs and p,p‧-DDE will remain in the atmospheric compartment the longest (beyond 2030). HCH's and PCB180 will be depleted from the Nordic atmosphere first, before 2020, whereas chlordanes and rest of the PCBs will be depleted between the years 2020 and 2025. PCBs tend to deplete sooner and chlordanes later from the sub-Arctic compared to the south of Sweden. This study demonstrates that the international bans on legacy POPs have successfully reduced the concentrations of these particular substances in the Nordic atmosphere. However, the most long-lived compounds may continue in the atmospheric cycle for another couple of decades.

  10. Spatial variability in persistent organic pollutants and polycyclic aromatic hydrocarbons found in beach-stranded pellets along the coast of the state of São Paulo, southeastern Brazil.

    Science.gov (United States)

    Taniguchi, Satie; Colabuono, Fernanda I; Dias, Patrick S; Oliveira, Renato; Fisner, Mara; Turra, Alexander; Izar, Gabriel M; Abessa, Denis M S; Saha, Mahua; Hosoda, Junki; Yamashita, Rei; Takada, Hideshige; Lourenço, Rafael A; Magalhães, Caio A; Bícego, Márcia C; Montone, Rosalinda C

    2016-05-15

    High spatial variability in polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides, such as DDTs, and polybrominated diphenylethers was observed in plastic pellets collected randomly from 41 beaches (15 cities) in 2010 from the coast of state of São Paulo, southeastern Brazil. The highest concentrations ranged, in ng g(-1), from 192 to 13,708, 3.41 to 7554 and <0.11 to 840 for PAHs, PCBs and DDTs, respectively. Similar distribution pattern was presented, with lower concentrations on the relatively less urbanized and industrialized southern coast, and the highest values in the central portion of the coastline, which is affected by both waste disposal and large port and industrial complex. Additional samples were collected in this central area and PCB concentrations, in ngg(-)(1), were much higher in 2012 (1569 to 10,504) than in 2009/2010 (173 to 309) and 2014 (411), which is likely related to leakages of the PCB commercial mixture.

  11. The indoor and outdoor concentrations of particulate air-pollution and PAHs in different size fractions and assessment of exposure and health impacts in the Copenhagen population[Polycyclic Aromatic Hydrocarbons; Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Alstrup Jensen, K.; Kofoed-Soerensen, V.; Clausen, Per Axel [Arbejdsmiljoeinstituttet (Denmark)

    2005-07-01

    Fifteen one-week samples of PM{sub 1}, PM{sub 2.5}, inhalable dust (PM{sub inh}) and 16 polyclyclic aromatic hydrocarbons (PAHs) were collected inside and outside of an uninhabited 4th floor apartment at the Jagtvej street canyon in central Copenhagen during winter, spring and summer in 2002. Similar urban background samples were collected at a 2 km distant 4th floor high rooftop. PAHs in PM{sub 1} and PM{sub inh} were collected on glass fibre filters only. PAHs in PM{sub 2.5} were collected on glass fibre filters followed by adsorbent sample and backup tubes containing Tenax. PM was determined by filter weighing. The following by high performance liquid chromatography with UV and fluorescence detection. (au)

  12. Multiphase hydrodechlorination of polychlorinated aromatics - Towards scale-up.

    Science.gov (United States)

    Perosa, Alvise; Selva, Maurizio; Maschmeyer, Thomas

    2017-04-01

    We describe a chemical technology for the reductive catalytic multiphase hydrodechlorination (HDC) of chlorinated aromatics to greatly reduce their toxicity and aid the disposal of such species. The system requires no solvent and the catalyst displays a high recycling efficiency. In the present case, 1,3-dichlorobenzene (1,3-DCB) was used as a model compound, and was quantitatively hydrodechlorinated to benzene with hydrogen, in a tri-phasic liquid system consisting of the chlorinated aromatic itself as the top organic phase, an aqueous sodium hydroxide bottom phase (that neutralises acids formed), and an Aliquat(®)336 (A336) intermediate phase containing a Pd/C catalyst. Once the reaction was complete the top phase (now just benzene) and the bottom phase (now principally aqueous NaCl) were removed and the remaining catalytic A336/(Pd/C) phase recycled. This model study was conducted on a multi-gram scale with a view of demonstrating its applicability to the detoxification of PCBs. Comparison of the Mass Intensity (MI) and turnover frequency (TOF) of our model reaction with three examples of published procedures for the HDC of DCB, indicated that the MI for our system (MI = 6.33) was lower by an order of magnitude or more than that of the others (MI = 27.9, 64.6, 96016), and that TOFs were comparable. A preliminary cost analysis indicates approximately 2000 €/tonne to treat tonne-scale amounts of chlorinated aromatics, making the system in principle useful for industrial implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Bioavailability of Polycyclic Aromatic Hydrocarbons in Soils and Sediments

    NARCIS (Netherlands)

    Cuypers, M.P.

    2001-01-01

    Polycyclic aromatic hydrocarbons (PAHs) constitute a group of priority pollutants which are of increasing environmental concern because of their adverse effects on humans, animals, and plants. Soils and sediments generally serve as a sink for PAHs, which leads to the accumulation of PAHs at contamin

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

    African Journals Online (AJOL)

    Michael Horsfall

    done with a view to assessing the level of attenuation of this particular group of crude hydrocarbons and the changes. /effects of some trace metals in the impacted soils. The aromatic hydrocarbon ... Nigeria has had its fair share of crude oil pollution. This problem is ... disintegration of natural organometalic plant metabolites.

  15. Synthesis and antifungal activity of halogenated aromatic bis-γ-lactones analogous to avenaciolide

    Directory of Open Access Journals (Sweden)

    Pedro A. Castelo-Branco

    2012-01-01

    Full Text Available Here we describe the total syntheses and characterization by elemental analyses, infrared and NMR spectroscopy of three new compounds analogous to avenaciolide, a bis-γ-lactone isolated from Aspergillus avenaceus that possesses antifungal activity, where the octyl group of the natural product was replaced by aromatic groups containing chlorine and fluorine atoms. The effects of the avenaciolide, the novel compounds and their synthetic precursors on mycelia development and conidia germination of Colletotrichum gloeosporioides and Fusarium solani were evaluated in vitro. The title compounds were almost as active as avenaciolide. The absolute structures of the chlorinated analogs were determined by X-ray diffraction analysis.

  16. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  17. Epoxy Coenzyme A Thioester pathways for degradation of aromatic compounds.

    Science.gov (United States)

    Ismail, Wael; Gescher, Johannes

    2012-08-01

    Aromatic compounds (biogenic and anthropogenic) are abundant in the biosphere. Some of them are well-known environmental pollutants. Although the aromatic nucleus is relatively recalcitrant, microorganisms have developed various catabolic routes that enable complete biodegradation of aromatic compounds. The adopted degradation pathways depend on the availability of oxygen. Under oxic conditions, microorganisms utilize oxygen as a cosubstrate to activate and cleave the aromatic ring. In contrast, under anoxic conditions, the aromatic compounds are transformed to coenzyme A (CoA) thioesters followed by energy-consuming reduction of the ring. Eventually, the dearomatized ring is opened via a hydrolytic mechanism. Recently, novel catabolic pathways for the aerobic degradation of aromatic compounds were elucidated that differ significantly from the established catabolic routes. The new pathways were investigated in detail for the aerobic bacterial degradation of benzoate and phenylacetate. In both cases, the pathway is initiated by transforming the substrate to a CoA thioester and all the intermediates are bound by CoA. The subsequent reactions involve epoxidation of the aromatic ring followed by hydrolytic ring cleavage. Here we discuss the novel pathways, with a particular focus on their unique features and occurrence as well as ecological significance.

  18. 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.

  19. Controlling the reactivity of chlorinated ethylenes with flavin mononucleotide hydroquinone.

    Science.gov (United States)

    Ciptadjaya, Christopher G E; Guo, Wen; Angeli, Jayni M; Obare, Sherine O

    2009-03-01

    Reduction rate constants of the chlorinated ethylenes cis-1,2-dichloroethylene (cis-DCE), trichloroethylene (TCE), and tetrachloroethylene (PCE) reacted with flavin mononucleotide hydroquinone (FMNH2) under anoxic conditions were investigated. FMNH2 was produced in methanol solvent by the photoreduction of FMN. In aqueous solution, FMN was not fully reduced to FMNH2 but instead yielded the semiquinone radical FMNH*. However, when FMN was anchored to nanocrystalline TiO2, band gap irradiation resulted in electron transfer from the TiO2 conduction band to FMN, thus yielding FMNH2. The FMNH2 generated in aqueous solution on the TiO2 surface was a stronger reductant toward chlorinated ethylenes, relative to FMNH2 in solution. Furthermore, by combining the reactivity of the TiO2 conduction band electrons [TiO2(e-(CB)] with FMNH2, reduction rate constants for the chlorinated ethylenes increased by 2 orders of magnitude relative to FMNH2 alone. The results show how biological molecules such as FMNH2 could have significant effects toward the remediation of organic pollutants.

  20. Amide Link Scission in the Polyamide Active Layers of Thin-Film Composite Membranes upon Exposure to Free Chlorine: Kinetics and Mechanisms.

    Science.gov (United States)

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2015-10-20

    The volume-averaged amide link scission in the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine was quantified at a variety of free chlorine exposure times, concentrations, and pH and rinsing conditions. The results showed that (i) hydroxyl ions are needed for scission to occur, (ii) hydroxide-induced amide link scission is a strong function of exposure to hypochlorous acid, (iii) the ratio between amide links broken and chlorine atoms taken up increased with the chlorination pH and reached a maximum of ∼25%, (iv) polyamide disintegration occurs when high free chlorine concentrations, alkaline conditions, and high exposure times are combined, (v) amide link scission promotes further chlorine uptake, and (vi) scission at the membrane surface is unrepresentative of volume-averaged scission in the active layer. Our observations are consistent with previously proposed mechanisms describing amide link scission as a result of the hydrolysis of the N-chlorinated amidic N-C bond due to nucleophilic attack by hydroxyl ions. This study increases the understanding of the physicochemical changes that could occur for membranes in treatment plants using chlorine as an upstream disinfectant and the extent and rate at which those changes would occur.

  1. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  2. Water Pollution

    Science.gov (United States)

    Bowen, H. J. M.

    1975-01-01

    Deals with water pollution in the following categories: a global view, self purification, local pollution, difficulties in chemical analysis, and remedies for water pollution. Emphasizes the extent to which man's activities have modified the cycles of certain elements. (GS)

  3. Water Pollution

    Science.gov (United States)

    Bowen, H. J. M.

    1975-01-01

    Deals with water pollution in the following categories: a global view, self purification, local pollution, difficulties in chemical analysis, and remedies for water pollution. Emphasizes the extent to which man's activities have modified the cycles of certain elements. (GS)

  4. "De Novo"-synthesis of chlorinated biphenyls, dibenzofurans and dibenzo-p-dioxins in the fly ash catalyzed reaction of toluene with hydrochloric acid

    NARCIS (Netherlands)

    Leer, E.W.B. de; Lexmond, R.J.; Zeeuw, M.A. de

    1989-01-01

    Toluene is converted into benzaldehyde and halogenated aromatic oxidation products in an air atmosphere at 425 °C with fly ash from a municipal waste incineration plant as the catalyst. Several halogenated products such as chlorinated and brominated benzenes, biphenyls and traces of PCDDs/PCDFs coul

  5. "De Novo"-synthesis of chlorinated biphenyls, dibenzofurans and dibenzo-p-dioxins in the fly ash catalyzed reaction of toluene with hydrochloric acid

    NARCIS (Netherlands)

    Leer, E.W.B. de; Lexmond, R.J.; Zeeuw, M.A. de

    1989-01-01

    Toluene is converted into benzaldehyde and halogenated aromatic oxidation products in an air atmosphere at 425 °C with fly ash from a municipal waste incineration plant as the catalyst. Several halogenated products such as chlorinated and brominated benzenes, biphenyls and traces of PCDDs/PCDFs

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-11-01

    This presentation reviews published information concerning the reactions of chlorine gas (CL/sub 2/(g)), aqueous chlorine, and ClO/sub 2/ 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 ClO/sub 2/. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and ClO/sub 2/ with several food products, including flour and shrimp, have also been characterized. 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.

  8. 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.

  9. Chlorine bleaches - A significant long term source of mercury pollution

    Science.gov (United States)

    Siegel, S. M.; Eshleman, A.

    1975-01-01

    Products of industrial electrolysis of brine - NaOCl-based bleaches and NaOH - yielded 17 to 1290 ppb of Hg upon flameless atomic absorption analysis. Compared with current U.S. rejection value of 5 ppb for potable waters, the above levels seem sufficiently high to be a matter of environmental concern.

  10. Biomarkers of genotoxicity of urban air pollution. Overview and descriptive data from a molecular epidemiology study on populations exposed to moderate-to-low levels of polycyclic aromatic hydrocarbons: the AULIS project

    DEFF Research Database (Denmark)

    Kyrtopoulos, S.A.; Georgiadis, P.; Autrup, H.

    2001-01-01

    -based population studies to aid the assessment of the genotoxic and carcinogenic effects of urban air pollution is reviewed by reference to the achievements and limitations of earlier reported studies. The design and methodology adopted in a recently completed large-scale population study, carried out...... in the context of the European Union Environment and Climate Programme, known by the short name of AULIS project, is discussed and descriptive statistics of the main findings of the project are presented. These findings indicate that for cohorts suffering moderate-to-low exposures to airborne particulate...

  11. Microbial degradation of monocyclic and polycyclic aromatic hydrocarbons in case of limited pollutant availability with nitrate as a potential electron acceptor; Der mikrobielle Abbau mono- und polyzyklischer aromatischer Kohlenwasserstoffe bei einer begrenzten Schadstoffverfuegbarkeit mit Nitrat als potentiellem Elektronenakzeptor

    Energy Technology Data Exchange (ETDEWEB)

    Linke, C.

    2001-07-01

    The possibility of using natural degradation processes for long-term remediation of tar oil contaminated sites was investigated. Field studies have shown that microbial decomposition of pollutants does take place in many sites but that it is limited by limited availability of pollutants and oxygen in soil. The investigations focused on the activation of BTEX and PAH degradation in situ by nitrate in the absence or in the presence of oxygen. Tensides should be used in order to enhance the availability of pollutants in water, especially in the case of hardly water-soluble PAH. A large-scale experiment was carried out on tar oil contaminated terrain; it was found that the availability of oxygen and not of PAH is the limiting factor so that adding of surfactants will not improve pollutant degradation. In contrast, the adding of tensides would mean even higher concentrations of oxygen-depleting substances in soil. [German] In der vorliegenden Arbeit wurden im Hinblick auf langfristige Sanierungsstrategien fuer teeroelkontaminierte Standorte Moeglichkeiten der Nutzung natuerlicher Abbauvorgaenge untersucht. Zahlreiche Feldstudien belegen, dass ein mikrobieller Schadstoffabbau an vielen Standorten stattfindet, dieser jedoch sowohl durch eine begrenzte Schadstoffverfuegbarkeit als auch durch den im Untergrund nur begrenzt zur Verfuegung stehenden Sauerstoff limitiert wird. Ziel dieser Arbeit war es abzuklaeren, inwiefern ein BTEX- und PAK-Abbau in situ auch in Abwesenheit von Sauerstoff durch Nitrat allein oder durch Nitrat in Kombination mit Sauerstoff aktiviert werden kann. Um insbesondere fuer die schlecht wasserloeslichen PAK eine ausreichende Schadstoffverfuegbarkeit zu gewaehrleisten, sollten auch Tenside zur Erhoehung der im Wasser vorliegenden Schadstoffmenge eingesetzt werden. Aufbauend auf die Laboruntersuchungen wurde im Rahmen von VEGAS{sup ix} ein Grossversuch zum mikrobiellen PAK-Abbau im Abstrom einer simulierten Teeroelkontamination durchgefuehrt

  12. Chlorine dioxide reaction with selected amino acids in water

    Energy Technology Data Exchange (ETDEWEB)

    Navalon, Sergio; Alvaro, Mercedes [Department of Chemistry, Universidad Politecnica de Valencia, Camino de Vera S/N, 46022 Valencia (Spain); Garcia, Hermenegildo, E-mail: hgarcia@qim.upv.es [Department of Chemistry, Universidad Politecnica de Valencia, Camino de Vera S/N, 46022 Valencia (Spain)

    2009-05-30

    Chlorine dioxide is a hypochlorite alternative disinfectant agent. In this context, we have determined the products formed in the reaction of ClO{sub 2} with selected amino acids as model compounds that can be present in natural waters. The reaction of tryptophane, histidine and tyrosine (10 ppm each) with ClO{sub 2} were studied at molar ratios ranging from 0.25 to 4 in the presence or absence of oxygen. It was found that in the absence of oxygen adding substoichiometric amounts of ClO{sub 2} creates products that are structurally similar to the starting amino acids. Through a series of cascade reactions the initial product distribution gradually evolves toward simple, small carbon chain products that are far from the starting amino acid. The reaction product distribution revealed that chlorine dioxide can attack the electron-rich aromatic moieties as well as the nitrogen atom lone electron pair. Our study is relevant to gain knowledge on the reaction mechanism of ClO{sub 2} with ubiquitous amino acids present in natural waters.

  13. Toluene-Degrading Bacteria Are Chemotactic towards the Environmental Pollutants Benzene, Toluene, and Trichloroethylene

    Science.gov (United States)

    Parales, Rebecca E.; Ditty, Jayna L.; Harwood, Caroline S.

    2000-01-01

    The bioremediation of polluted groundwater and toxic waste sites requires that bacteria come into close physical contact with pollutants. This can be accomplished by chemotaxis. Five motile strains of bacteria that use five different pathways to degrade toluene were tested for their ability to detect and swim towards this pollutant. Three of the five strains (Pseudomonas putida F1, Ralstonia pickettii PKO1, and Burkholderia cepacia G4) were attracted to toluene. In each case, the response was dependent on induction by growth with toluene. Pseudomonas mendocina KR1 and P. putida PaW15 did not show a convincing response. The chemotactic responses of P. putida F1 to a variety of toxic aromatic hydrocarbons and chlorinated aliphatic compounds were examined. Compounds that are growth substrates for P. putida F1, including benzene and ethylbenzene, were chemoattractants. P. putida F1 was also attracted to trichloroethylene (TCE), which is not a growth substrate but is dechlorinated and detoxified by P. putida F1. Mutant strains of P. putida F1 that do not oxidize toluene were attracted to toluene, indicating that toluene itself and not a metabolite was the compound detected. The two-component response regulator pair TodS and TodT, which control expression of the toluene degradation genes in P. putida F1, were required for the response. This demonstration that soil bacteria can sense and swim towards the toxic compounds toluene, benzene, TCE, and related chemicals suggests that the introduction of chemotactic bacteria into selected polluted sites may accelerate bioremediation processes. PMID:10966434

  14. Catalytic hydrogen-chlorine exchange between chlorinated hydrocarbons under oxygen-free conditions

    NARCIS (Netherlands)

    van der Heijden, A.W.A.M.; Podkolzin, S.G.; Jones, M.E.; Bitter, J.H.; Weckhuysen, B.M.

    2008-01-01

    Chlorinated hydrocarbons (CHCs) remain important industrial chemical intermediates and solvents, especially for the exploration of the potential of La-based materials for the conversion of chlorinated waste compounds.[1] The production of industrially important CHCs frequently occurs with concurrent

  15. Determination of Chlorinated Persistent Organic Pollutants in Infant Hair by Gas Chromatography_High Resolution Mass Spectrometry%气相色谱高分辨质谱测定婴儿胎发中含氯持久性有机污染物

    Institute of Scientific and Technical Information of China (English)

    宋淑玲; 胡小健; 祁鹏; 李松; 佟玲; 田芹; 马晓东

    2015-01-01

    Infant hair is a good medium to assess the cumulative exposure level of infant in the mother ' s body. Chlorinated persistent organic pollutants were ubiquitous and with the highest volume concentration in the human body. In this experiment, 20 infant hairs were collected from Beijing. The sample was overnight incubated in HCl, extracted with the mixture of hexane and dichloromethane, and cleaned up by a cartridge filled with alumina and acidified silica. The final eluate was concentrated, and 16 kinds of typical chlorinated persistent organic pollutants were detected with gas chromatography_high resolution mass spectrometry ( HRGC_MS). The results showed that the detection limit of the target compounds in sample was 1. 00-2. 50 μg/kg, the recovery of surrogate in all samples was more than 67 . 6%, and the range of recoveries for target compounds in spiked sample was 62. 5%-92. 3%. The positive rate is 100% for hexachlorobenzene,β_HCH and p, pˊ_DDE, 85% for γ_HCH, 50% for PCB28, and 40% for PCB52. The concentrations of Hexachlorobenzene, HCHs, DDTs and PCBs were 5. 48-8. 40 μg/kg, 3. 86-27. 1 μg/kg, 1. 16-18. 3 μg/kg and 2. 20-22. 1 μg/kg, respectively. The average concentrations were 7. 84 μg/kg for hexachlorobenzene, 6. 93 μg/kg for HCHs, 5. 53 μg/kg for DDTs, and 3. 44 μg/kg for PCBs. The method and the analysis results can be used to evaluate the accumulation level and cumulative exposure level of 16 target compounds for fetal in motherˊs body.%婴儿的胎发是评价婴儿在母体环境中污染物累积暴露水平的良好介质。含氯持久性有机污染物是人体中残留浓度最高的持久性有机污染物。本研究依次采用HCl酸化、正己烷/二氯甲烷混合溶液萃取、硅胶和氧化铝混合填充小柱净化,以及气相色谱高分辨质谱法检测了北京20个婴儿胎发中的16种典型含氯持久性有机污染物。结果表明,16种目标物的检出限可达到1.0~2.5μg/kg,替代物五氯硝基苯

  16. 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.

  17. Chemical oxidation of dissolved organic matter by chlorine dioxide, chlorine, and ozone: effects on its optical and antioxidant properties.

    Science.gov (United States)

    Wenk, Jannis; Aeschbacher, Michael; Salhi, Elisabeth; Canonica, Silvio; von Gunten, Urs; Sander, Michael

    2013-10-01

    In water treatment dissolved organic matter (DOM) is typically the major sink for chemical oxidants. The resulting changes in DOM, such as its optical properties have been measured to follow the oxidation processes. However, such measurements contain only limited information on the changes in the oxidation states of and the reactive moieties in the DOM. In this study, we used mediated electrochemical oxidation to quantify changes in the electron donating capacities (EDCs), and hence the redox states, of three different types of DOM during oxidation with chlorine dioxide (ClO2), chlorine (as HOCl/OCl(-)), and ozone (O3). Treatment with ClO2 and HOCl resulted in comparable and prominent decreases in EDCs, while the UV light absorbances of the DOM decreased only slightly. Conversely, ozonation resulted in only small decreases of the EDCs but pronounced absorbance losses of the DOM. These results suggest that ClO2 and HOCl primarily reacted as oxidants by accepting electrons from electron-rich phenolic and hydroquinone moieties in the DOM, while O3 reacted via electrophilic addition to aromatic moieties, followed by ring cleavage. This study highlights the potential of combined EDC-UV measurements to monitor chemical oxidation of DOM, to assess the nature of the reactive moieties and to study the underlying reaction pathways.

  18. 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.

  19. 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

  20. Residential exposure to chlorinated hydrocarbons from groundwater contamination and the impairment of renal function-An ecological study

    Science.gov (United States)

    Chen, Hui-Ming; Wu, Ming-Tsang

    2017-01-01

    Groundwater pollution from the petrochemical industry causes serious deterioration of soil and groundwater quality and impacts on human health worldwide. However, few studies have examined the effect of residential exposure to petrochemical chlorinated hydrocarbon-contaminated groundwater on renal function impairment in humans. We conducted an ecological study to investigate the two. A polyvinyl chloride (PVC) plant was located in one of the six villages, the study area, in Kaohsiung city of southwestern Taiwan. Based on the direction of groundwater flow and previous groundwater measurements of chlorinated hydrocarbons from Taiwan Environmental Protection Bureau, we divided the six villages into highly-polluted villages, moderately-polluted villages, and a non-polluted village. All inhabitants in those six villages were invited to receive free health examinations between May-June, 2010. In total, 4,432 study subjects ≥18 yrs old were analyzed. Compared to those in the non-polluted village, subjects in highly-polluted villages had 1.89- and 1.46-fold the risk of impaired estimated glomerular filtration rate (eGFR) and proteinuria (95% CI = 1.15–1.85 and 1.09–3.28, respectively) after adjusting for other covariates. Given this relative large sample size, we found that groundwater chlorinated hydrocarbon pollution can cause kidney damage in adults. PMID:28067285

  1. Residential exposure to chlorinated hydrocarbons from groundwater contamination and the impairment of renal function-An ecological study

    Science.gov (United States)

    Chen, Hui-Ming; Wu, Ming-Tsang

    2017-01-01

    Groundwater pollution from the petrochemical industry causes serious deterioration of soil and groundwater quality and impacts on human health worldwide. However, few studies have examined the effect of residential exposure to petrochemical chlorinated hydrocarbon-contaminated groundwater on renal function impairment in humans. We conducted an ecological study to investigate the two. A polyvinyl chloride (PVC) plant was located in one of the six villages, the study area, in Kaohsiung city of southwestern Taiwan. Based on the direction of groundwater flow and previous groundwater measurements of chlorinated hydrocarbons from Taiwan Environmental Protection Bureau, we divided the six villages into highly-polluted villages, moderately-polluted villages, and a non-polluted village. All inhabitants in those six villages were invited to receive free health examinations between May-June, 2010. In total, 4,432 study subjects ≥18 yrs old were analyzed. Compared to those in the non-polluted village, subjects in highly-polluted villages had 1.89- and 1.46-fold the risk of impaired estimated glomerular filtration rate (eGFR) and proteinuria (95% CI = 1.15–1.85 and 1.09–3.28, respectively) after adjusting for other covariates. Given this relative large sample size, we found that groundwater chlorinated hydrocarbon pollution can cause kidney damage in adults.

  2. High resolution spectrophotometry for identification of chlorine dioxide in concentrated chlorine solutions.

    Science.gov (United States)

    Gauw, R D; Emmert, G L; Bubnis, B; Gordon, G

    1999-12-06

    Electrolyzed salt brine generators hold great promise for water disinfection in small communities and remote locations. Electrolysis cell liquors have been reported to contain chlorine, chlorine dioxide and ozone. High resolution spectrophotometry was used to observe the presence (or absence) of a unique spectral absorbance pattern present in solutions containing 1-2 mg/l chlorine dioxide.

  3. Pollution Probe.

    Science.gov (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  4. Reactions of phenylurea compounds with aqueous chlorine: Implications for herbicide transformation during drinking water disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Chusaksri, Sarinma [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Kasetsart, Bangkok 10900 (Thailand); Sutthivaiyakit, Somyote [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240 (Thailand); Sedlak, David L., E-mail: sedlak@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Sutthivaiyakit, Pakawadee, E-mail: fscipws@ku.ac.th [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Kasetsart, Bangkok 10900 (Thailand)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Mechanism of chlorine reaction with phenylurea compounds has been studied. Black-Right-Pointing-Pointer It depends on both chlorinating species and substitutents on the compounds. Black-Right-Pointing-Pointer Main products were identified using LC-MS/MS and authentic standards. Black-Right-Pointing-Pointer Their transformation under normal drinking water disinfection was predicted. - Abstract: Phenylurea herbicides have been known to contaminate surface waters serving as potable supplies. To access the potential for transformation of these compounds during drinking water treatment, reactions of phenylurea compounds with aqueous chlorine at different pHs were investigated. The effect of substitution at the amino-N on the rate of transformation depends upon pH. Under acidic conditions, all of the phenylurea studied except 3,4-dichloro-3 Prime -N-methylphenylurea (3,4-DCMPU) exhibited third-order kinetics, second order with respect to chlorine and first order with respect to phenylurea, while the reactions of 3,4-DCMPU were first order with respect to both chlorine and the organic compound. Under neutral and alkaline conditions, all compounds exhibited second-order kinetics that was first order with respect to chlorine and the organic compound. Apparent second-order rate constants at 25 Degree-Sign C and pH 7 were 0.76 {+-} 0.16, 0.52 {+-} 0.11, 0.39 {+-} 0.02, 0.27 {+-} 0.04 and 0.23 {+-} 0.05 M{sup -1} s{sup -1} for phenylurea, 3, 4-dichlorophenylurea, 3, 4-DCMPU, metoxuron and monuron, respectively. Studies of the chlorination products, monitored by LC/MS/MS, under different pH values indicated the reaction to take place at both N atoms and also at ortho- and para- positions of the phenylurea aromatic group. The main chlorinating species were found to be different in different pH ranges. Under conditions typically encountered in drinking water treatment systems, transformation of these compounds by chlorine will be

  5. 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.

  6. Laser atomic emission analysis of airborne pollution of green stands by deicing agents

    Science.gov (United States)

    Bel'Kov, M. V.; Burakov, V. S.; Kiris, V. V.; Maksimova, I. A.; Raikov, S. N.; Sudnik, A. V.

    2010-05-01

    We present the results of analysis of airborne pollution of green stands along the Minsk Beltway by components of deicing agents (chlorine). We used laser spectral analysis for rapid determination of chlorine. Comparison of the analysis results for accumulation of salt components in samples collected from trees along the Minsk Beltway with control samples showed that the chlorine content is 3.7-5.5 times higher than the control values. The degree of pollution depends on the position of the trees on the forest edge relative to the highway, which is confirmed by reliable correlation coefficients.

  7. 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...

  8. Urban air pollution climates throughout the world

    DEFF Research Database (Denmark)

    Hertel, Ole; Goodsite, Michael Evan

    2009-01-01

    as well as the transport in and out of the city area. The building obstacles play a crucial role in causing generally high pollutant levels in the urban environment, especially inside street canyons where the canyon vortex flow governs the pollution distribution. Of the pollutants dominating urban air......The extent of the urban area, the local emission density, and the temporal pattern in the releases govern the local contribution to air pollution levels in urban environments. However, meteorological conditions also heavily affect the actual pollution levels as they govern the dispersion conditions...... pollution climates, particulate pollution in general together with gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) and heavy metals are those where further field measurements, characterization and laboratory studies are urgently needed in order to fully assess the health impact on the urban...

  9. Inactivation of simian rotavirus SA11 by chlorine, chlorine dioxide, and monochloramine.

    OpenAIRE

    Berman, D; Hoff, J C

    1984-01-01

    The kinetics of inactivation of simian rotavirus SA11 by chlorine, chlorine dioxide, and monochloramine were studied at 5 degrees C with a purified preparation of single virions and a preparation of cell-associated virions. Inactivation of the virus preparations with chlorine and chlorine dioxide was studied at pH 6 and 10. The monochloramine studies were done at pH 8. With 0.5 mg of chlorine per liter at pH 6, more than 4 logs (99.99%) of the single virions were inactivated in less than 15 s...

  10. 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.

  11. Monitoring of pollution in sediments

    Directory of Open Access Journals (Sweden)

    Renee I. Abdallah

    2016-03-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs and aliphatic hydrocarbons (AHs were analyzed in surface sediments collected from Suez till Hurgharda coasts to establish baseline levels for various types of organic pollutants before the anticipated identification of anthropogenic activities, petrogenic and biogenic. AHs for all samples were dominated by unresolved complex mixture (UCM, and petrogenic mixed with biogenic sources. Results also revealed that sedimentary PAHs mainly originated from pyrolysis sources.

  12. The photoreactivity of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Vaida, V. [Univ. of Colorado, Boulder, CO (United States); Simon, J.D. [Univ. of California, San Diego, La Jolla, CA (United States)

    1995-06-09

    Determining the detailed photoreactivity of radicals that are of importance in atmospheric processes requires information from both laboratory and field measurements and theoretical calculations. Laboratory experiments and quantum calculations have been used to develop a comprehensive understanding of the photoreactivity of chlorine dioxide (OClO). The photoreactivity is strongly dependent on the medium (gas phase, liquid solution, or cryogenic matrix). These data reveal details of the complex chemistry of OClO. The potential role of this radical in stratospheric ozone depletion is discussed in accord with these laboratory measurements. 53 refs., 4 figs.

  13. In Situ Bioremediation of Chlorinated Ethenes in Hydraulically-Tight Sediments: Challenges and Limitations

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2011-12-01

    Chlorinated ethenes, like perchloroethene (PCE) and trichloroethene (TCE), have been widely used by many industries, especially in developed countries like Japan. Because of their wide applications, lack of proper regulation, poor handing, storage and disposal practices in the past, chlorinated ethenes have become a type of the most prevalent contaminants for soils and groundwater pollution. For the sake of their degradability, bioremediation has been considered as a potentially cost-effective and environmentally friendly approach for cleanup of chlorinated ethenes in situ. In this presentation, we briefly overview the status of soil and groundwater pollution, the recent amendment of the Soil Contamination Countermeasures Act in Japan, comparison between the bioremediation and other techniques like pump and treat, and the mechanisms of reductive dechlorination, direct oxidation and co-metabolism of chlorinated ethenes. We then introduce and discuss some recent challenges and advancements in in-situ bioremediation including technologies for accelerating bio-degradation of chlorinated ethenes, technologies for assessing diffusive properties of dissolved hydrogen in hydraulically-tight soil samples, and combination of bioremediation with other techniques like electro-kinetic approach. Limiting factors that may cause incomplete remediation and/or ineffectiveness of bioremediation are examined from biochemical, geochemical and hydro-geological aspects. This study reconfirmed and illustrated that: 1) The key factor for an effective bioremediation is how to disperse a proper accelerating agent throughout the polluted strata, 2) The effective diffusion coefficient of dissolved hydrogen in geologic media is relatively big and is almost independent on their permeability, and 3) To effectively design and perform an accelerated bioremediation, a combination of natural migration with pressurized injection and/or other approaches, like electro-migration, for stimulating mass

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Korich, D.G.; Mead, J.R.; Madore, M.S.; Sinclair, N.A.; Sterling, C.R. (Univ. of Arizona, Tucson (USA))

    1990-05-01

    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.

  16. 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

  17. 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.

  18. Mutagenic compounds from chlorination of humic substances

    Science.gov (United States)

    Holmbom, Bjarne

    Chlorination of natural humic substances, as well as of lignin, produces a myriad of non-chlorinated and chlorinated compounds. The identification of an important class of strongly mutagenic compounds is reviewed. The most important Ames mutagen in chlorinated drinking waters of various origin is the compound 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone ("MX"). This compound occurs at neutral pH in the acyclic form, i.e. in the form of Z-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid. Its E-isomer (E-MX) is present in chlorinated drinking waters at a similar concentration, but is less mutagenic in Ames test. Both oxidised and reduced forms of MX and E-MX are also present in chlorinated waters. The present knowledge of the chemistry and toxicology of these mutagens is examined. The formation and possible elimination of the chlorination mutagens is discussed. The need of understanding the mechanisms of formation of these mutagens from humic substances during drinking water chlorination is emphasized.

  19. Chlorination products: emerging links with allergic diseases.

    Science.gov (United States)

    Bernard, A

    2007-01-01

    Exposure of the human population to chlorination products has considerably increased during the 20(th) century especially after the 1960s with the development of public and leisure pools. The present article summarizes current knowledge regarding the human exposure to chlorination products and reviews studies suggesting that these chemicals might be involved in the development or exacerbation of allergic diseases. Populations regularly in contact with chlorination products such as swimmers, lifeguards or workers using chlorine as cleaning or bleaching agent show increased risks of allergic diseases or of respiratory disorders frequently associated with allergy. Experimental evidence suggests that chlorination products promote allergic sensitization by compromising the permeability or the immunoregulatory function of epithelial barriers. These findings led to the chlorine hypothesis proposing that the rise of allergic diseases could result less from the declining exposure to microbial agents (the hygiene hypothesis) than from the increasing and largely uncontrolled exposure to products of chlorination, the most widely used method to achieve hygiene in the developed world. Giving the increasing popularity of water recreational areas, there is an obvious need to assess the effects of chlorine-based oxidants on human health and their possible implication in the epidemic of allergic diseases.

  20. ACUTE STUDIES OF INHALED CHLORINE IN F344 RATS SUGGEST ALTERNATIVE TO HABER'S RULE FOR RISK EXTRAPOLATIONS

    Science.gov (United States)

    Chlorine (CI2), a high-production volume air pollutant, is an irritant of interest to homeland security. Risk assessment approaches to establish egress or re-entry levels typically use an assumption based on Haber's Rule and apply a concentration times duration ("C x t") adjustme...

  1. Investigation of the genotoxic effects of chlorine bleach and dishwashing detergent on Guppy (Poecillia reticulata Peters, 1859) by using the micronucleus test

    OpenAIRE

    ARSLAN, Pınar; DALGIÇ, Mehmet Ali; SARIÇAKMAK, Sedanur; SARIGİL, Necla; ÜLKER, Şeyma; MEMMİ, Burcu KOÇAK

    2011-01-01

    In this study, the potential genotoxic effects of dishwashing detergent and chlorine bleach, which pollute aquatic ecosystems due to domestic, industrial and general uses were investigated on the standard test organism Guppy (Poecillia reticulata Peters, 1859) by using the fish erythrocyte micronucleus test. The fish were exposed to dishwashing detergent and chlorine bleach at 15 μl/L concentration for 96 hours and blood samples were taken after 96 hours from Poecillia reticulata. M...

  2. 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.)

  3. Report: New reliable method for the measurement of chlorine in refuse-derived fuels through combustion experiments in a pilot plant.

    Science.gov (United States)

    Schröer, Ramona; Urban, A I

    2010-02-01

    The calorific values and the chlorine contents of refuse-derived fuels were measured in the pilot combustion plant (PCP) by means of combustion experiments followed by mass and energy balancing. This plant reaches an increased precision by measuring the integrated values throughout the whole experimental period of three hours, based on a fuel capacity of 10 kg per test, allowing a more reliable measurement of pollutants than for experimental analysis of only a few grams of the sample. The combustion experiments are shown for the verification of the quality of the chlorine balancing in the PCP. The test evaluation was carried out by balancing the inputs and outputs of chlorine in the mass streams, and the recovery rates for chlorine were determined. An emission pattern for the chlorine is described by the transfer coefficients and via the temporal fluctuation of the hydrogen chloride concentration in the flue gas. The results of the combustion experiments prove that the balancing via combustion experiments in the PCP provides reliable data on the chlorine concentrations in the fuels, and is a new and reliable method for measuring polluting chlorine in refuse-derived fuels.

  4. FIGAERO ToF CIMS measurements of chlorine photochemical activation by nitryl chloride chemistry at a semi-rural site in Beijing

    Science.gov (United States)

    Le Breton, Michael; Hallquist, Åsa M.; Kant Pathak, Ravi; Simpson, David; Wang, Yujue; Zheng, Jing; Yang, Yudong; Shang, Dongjie; Wang, Haichao; Lu, Keding; Guo, Song; Hu, Min; Hallquist, Mattias

    2017-04-01

    Severe pollution events across China pose a major threat to air quality and climate through the direct emission of pollutants, but also via the production of photochemically induced secondary pollutants. Nitryl chloride (ClNO2), produced from heterogeneous reactions of dinitrogen pentoxide (N2O5) and aerosols containing chloride, is photolysed rapidly in sunlight and activates chlorine. Subsequent daytime oxidation via the chlorine atom can proceed orders of magnitude faster than that of the hydroxyl radical and therefore significantly perturb radical budgets and concentrations of ozone and secondary pollutants. Knowledge of the formation pathways, abundance and fate of these secondary pollutants, which can depend on ClNO2 abundance, is not fully understood but is necessary to support abatement strategies which will efficiently account for both primary and secondary pollutants. A Time of Flight Chemical Ionisation Mass Spectrometer (ToF CIMS) utilising the Filter Inlet for Gases and AEROsols (FIGAERO) was deployed in Changping, Beijing, during June and July, 2016 as part of an intercollaborative project to assess the photochemical smog in China. Concentrations of ClNO2 regularly exceeded 500 ppt throughout the campaign and reached a maximum concentration of 2.8 ppb, whereas relatively low N2O5 concentrations were observed, indicating a rapid heterogeneous production of ClNO2. Correlation of particulate chloride and carbon monoxide during the campaign suggests an anthropogenic chlorine source, also supported by high daytime Cl2 concentrations. Observations of ClNO2 desorptions using the FIGAERO suggest a possible unaccounted particulate reservoir of active chlorine in highly polluted regions. The persistence of ClNO2 several hours passed sunrise significantly increases the atomic chlorine production rate throughout the day further perturbing standard daytime oxidation processes. Simultaneous ToF CIMS measurements of Cl2, ClNO2, HCl, HOCl, OClO and ClONO2 were

  5. Profiles and inventories of organic pollutants in sediments from the central Beibu Gulf and its coastal mangroves.

    Science.gov (United States)

    Kaiser, David; Schulz-Bull, Detlef E; Waniek, Joanna J

    2016-06-01

    Sediment cores from the central Beibu Gulf and its northern coastal mangroves were analyzed for polycyclic aromatic hydrocarbons (PAH), the organo-chlorine pesticides dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), and polychlorinated biphenyls (PCB), to reconstruct the organic pollution history of developing south-west China. Reflecting regional development, in the gulf ∑PAH (38-74 ng g(-1)) decreased towards the surface after peak concentrations near 10 cm, while ∑DDT (ND - 0.5 ng g(-1)) increased due to fresh inputs, and HCB (ND - 0.04 ng g(-1)) occurred only in surface sediments. Profiles in mangrove sediments showed a continuing local scale increase in ∑PAH (29-438 ng g(-1)) as well as ∑DDT (0.2-41.0 ng g(-1)) and HCB (0.01-1.01 ng g(-1)) pollution, despite some variability. No trend was evident for ∑PCB (ND - 0.22 ng g(-1)), which was not detected in the central gulf. Calculated loads estimate that 2816 ng cm(-2) PAHs and 7 ng cm(-2) DDTs are stored in depositional areas of the Beibu Gulf. Mangrove sediments, threatened by land-use-change, contain 1400-4600 ng cm(-2) PAHs and 34-39 ng cm(-2) DDTs.

  6. Bioaccumulation of metallic trace elements and organic pollutants in marine sponges from the South Brittany Coast, France.

    Science.gov (United States)

    Gentric, Charline; Rehel, Karine; Dufour, Alain; Sauleau, Pierre

    2016-01-01

    The purpose of this study was to compare the accumulation of metallic and organic pollutants in marine sponges with the oyster Crassostrea gigas used as sentinel species. The concentrations of 12 Metallic Trace Elements (MTEs), 16 Polycyclic Aromatic Hydrocarbons (PAHs), 7 PolyChlorinated Biphenyls (PCBs), and 3 organotin derivatives were measured in 7 marine sponges collected in the Etel River (South Brittany, France). Results indicated Al, Co, Cr, Fe, Pb, and Ti particularly accumulated in marine sponges such as Hymeniacidon perlevis and Raspailia ramosa at higher levels compared to oysters. At the opposite, Cu and Zn accumulated significantly at higher concentrations in oysters. Among PAHs analyzed, benzo(a)pyrene bioaccumulated in H. perlevis at levels up to 17-fold higher than in oysters. In contrast, PCBs bioaccumulated preferentially in oysters. Significant differences exist in the abilities of marine phyla and sponge species to accumulate organic and metallic pollutants however, among the few sponge species studied, H. perlevis showed impressive bioaccumulation properties. The use of this species as bioindicator and/or bioremediator near shellfish farming areas is also discussed.

  7. Environmental pollutants and skin cancer.

    Science.gov (United States)

    Baudouin, C; Charveron, M; Tarroux, R; Gall, Y

    2002-01-01

    We are increasingly exposed to environmental pollution. Pollutants can be inhaled, ingested or come into contact with the skin depending on the form in which they occur. On metabolization, activation, or accumulation, pollutants can become extremely toxic for the vital organs and this is often related to a strong genotoxic effect. Since the skin acts as a barrier between the organism and the environment, it is frequently directly exposed to pollution. It is very often degraded by polluting agents and acts as an inlet toward other tissues. Numerous studies in man recognize and demonstrate the carcinogenic power of certain pollutants in the digestive and respiratory tracts. The "pollutants" that react most specifically with the skin are: ultraviolet radiation, polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene), volatile organic compounds (e.g., benzene), heavy metals, and ozone. Ultraviolet radiation, a "physical" pollutant, has been described as being the factor responsible for most skin cancers in man. The genotoxicity of UV light is well documented (type of lesion or mutation, etc.) and its carcinogenic effect is clearly demonstrated in vivo in man. A few epidemiological studies describe the carcinogenicity of certain pollutants such as arsenic or lead on the skin. However, most of the evidence for the role of pollutants in skin cancers comes from in vivo animal studies or from in vitro studies (e.g., PAHs). In this report, different studies are presented to illustrate the research strategies developed to investigate the mechanism of action of "chemical" pollutants and their potential role in human skin pathology. All the study models and the associated techniques of investigation are tools for a better understanding and thus more efficient prevention of the deleterious effects caused by the environment.

  8. Enviormental Pollution

    Directory of Open Access Journals (Sweden)

    Kanika Saini

    2016-06-01

    Full Text Available Environment Pollution is one of the greatest problems today which is increasing with every passing year and causing crucial and severe damage to the earth. It has become a real problem since the beginning of the industrial revolution. It is the contamination of physical and biological components of the Earth / atmosphere system to such an extent that normal environmental processes are harmed. Pollution of the environment consists of five main types of pollution, namely air, water, soil, noise and light. Development activities such as construction, transport and manufacturing not only deplete natural resources, but also produce large quantities of waste which leads to air pollution, water, soil and the oceans; global warming and acid rain. This paper provides the insight view about the affects of environment pollution in the perspective of air pollution, water and land/ soil waste pollution on human and also provide the ways to save the environment with all these pollution.

  9. Water pollution

    OpenAIRE

    Institute, Marine

    2013-01-01

    Students will learn about what causes water pollution and how to be environmentally aware. *Note: Students should understand the concept of the water cycle before moving onto water pollution (see Lesson Plan “Oceans all Around Us”).

  10. Aromaticity Competition in Differentially Fused Borepin-Containing Polycyclic Aromatics.

    Science.gov (United States)

    Messersmith, Reid E; Siegler, Maxime A; Tovar, John D

    2016-07-01

    This report describes the synthesis and characterization of a series of borepin-based polycyclic aromatics bearing two different arene fusions. The borepin synthesis features streamlined Ti-mediated alkyne reduction, leading to Z-olefins, followed by direct lithiation and borepin formation. These molecules allow for an assessment of aromatic competition between the fused rings and the central borepin core. Crystallographic, magnetic, and computational studies yielded insights about the aromaticity of novel, differentially fused [b,f]borepins and allowed for comparison to literature compounds. Multiple borepin motifs were also incorporated into polycyclic aromatics with five or six rings in the main backbone, and their properties were also evaluated.

  11. Edge chlorination of hexa-peri-hexabenzocoronene investigated by density functional theory and vibrational spectroscopy.

    Science.gov (United States)

    Maghsoumi, Ali; Narita, Akimitsu; Dong, Renhao; Feng, Xinliang; Castiglioni, Chiara; Müllen, Klaus; Tommasini, Matteo

    2016-04-28

    We investigate the molecular structure and vibrational properties of perchlorinated hexa-peri-hexabenzocoronene (HBC-Cl) by density functional theory (DFT) calculations and IR and Raman spectroscopy, in comparison to the parent HBC. The theoretical and experimental IR and Raman spectra demonstrated very good agreement, elucidating a number of vibrational modes corresponding to the observed peaks. Compared with the parent HBC, the edge chlorination significantly alters the planarity of the molecule. Nevertheless, the results indicated that such structural distortion does not significantly impair the π-conjugation of such polycyclic aromatic hydrocarbons.

  12. Determination of chlorinated polycyclic aromatic hydrocarbons in dust by solid-phase extract(SPE) and gas chromatofraphy-mass spectrometry%固相萃取/气相色谱质谱法测定灰尘中的氯代多环芳烃

    Institute of Scientific and Technical Information of China (English)

    郑继三; 马静; Yuichi Horii; Kurunthachalam Kannan; Takeshi Ohura; 徐刚; 吴明红

    2012-01-01

    A method was developed for the detection of 20 chlorinated polycyclic hydrocarbons(ClPAHs) in dust samples by solid-phase extract(SPE) and gas chromatography-mass spectrometry(GC/MS).The samples were Soxhlet extracted with dichloromethane-hexane mixture for more than 16 h.The extracts were purified through activated silica gel glass column,and then the SPE column self-packed with activated carbon-blended silica gel mixture.After cleanup,the extracts were analyzed by GC/MS in SIM mode,using characteristic ions for quantification.The SPE packed with a 0.2 g mixture of activated carbon-blended silica gel(1 ∶ 40,W/W) was found to have a good selectivity in separating ClPAHs from interference.And it reduced the toxic eluate when the SPE column was back-flushed after the sample extracts were loaded.The linear range,recovery and MDLs of 20 ClPAHs were examined.The recoveries of ClPAHs ranged from 60.4% to 120.1%,and the correlation coefficient was more than 0.99.The pretreatment procedure of this method is easy,and the quantification is sensitive and accurate.The method can be used to detect ClPAHs in many ambient media.%建立了固相萃取(SPE)/气相色谱质谱(GC/MS)联用检测灰尘中氯代多环芳烃(ClPAHs)的方法.以正己烷和二氯甲烷混合液为提取溶剂,索氏提取灰尘样品中的20种ClPAHs,活性硅胶层析柱与活性炭混合硅胶SPE柱协同净化.净化后的提取液采用GC/MS测定,SIM模式扫描,并用质谱特征离子定量分析.结果表明,填充量为0.2 g(W(活性炭)∶W(硅胶)=1∶40)的活性炭混合硅胶SPE小柱能有效地将ClPAHs分离出来,载样后采用反向溶剂洗脱,既提高了回收率又减少了洗脱剂甲苯的用量,净化效果好.处理灰尘样品后检测分析,20种ClPAHs的平均回收率稳定在60.4%—120.1%,相关系数〉0.99,检出限为0.04—0.17 ng.g-1,相对标准偏差为1.6%—10.2%.本方法前处理简单,定性、定量准确可靠,

  13. Air Pollution.

    Science.gov (United States)

    Barker, K.; And Others

    Pollution of the general environment, which exposes an entire population group for an indeterminate period of time, certainly constitutes a problem in public health. Serious aid pollution episodes have resulted in increased mortality and a possible relationship between chronic exposure to a polluted atmosphere and certain diseases has been…

  14. Microorganic pollutants in the outskirts of Rome.

    Science.gov (United States)

    Sbrilli, Andrea; Guerriero, Ettore; Bianchini, Massimo; Rotatori, Mauro; Cecinato, Angelo

    2003-01-01

    A short field campaign was performed in the outskirts of Rome at four sites located pretty along the four rose wind directions to city centre. Both chlorinated (PCB and PCDD/F) and non-chlorinated (n-alkanes, PAH, nitrated-PAH, n-alkanoic acids) organic micropollutants were investigated for their contents in the atmosphere. Concentrations reached by these pollutants in the outskirts were compared to those found in downtown Rome, both inside and outside of its largest city garden. Although concentrations of organic pollutants found in the outskirts were quite low, however they seemed enough high to induce some health risk in humans. Rural sites were less affected than industrial and waste disposal/treatment areas.

  15. Isotope Fractionation of chlorine in Aqueous System: One Study on Anion-Exchange Chromatography.

    Science.gov (United States)

    Musashi, M.; Oi, T.; Eggenkamp, H.; Van Cappellen, P.

    2001-05-01

    Stable chlorine isotopes such as 37Cl and 35Cl have been paid attention as useful tool identifying the source, and monitoring the transport process and natural fate of chlorinated organic pollutants in air and groundwater. However, it is not established yet whether any isotope effects accompany biodegradation or reductive dehalogenation of the pollutants (Clark and Fritz, 1997). Here we first present an experimental determination of isotope fractionation factor of chlorine in aqueous system by using anion-exchange chromatographic technique. Into the Cl-free anion exchange resin (Muromac, OH- form) packed in a 30 cm long pyrex glass column and controlled temperature at 25 oC, hydrochloric solution was fed with controlling the flow rate constant. Effluent from the column was recovered by an automatic fraction collector and prepared for Cl isotope analysis. The Cl isotope ratio (δ 37Cl vs. SMOC) was measured by IR-MS at the Utrecht University with precision of 0.06 per-mil. Magnitude of the factor obtained was 1.00035 at 25 oC. The result indicates that the lighter isotope (35Cl) was preferably fractionated into the resin phase, while the heavier one (37Cl) was enriched into the aqueous phase. This trend suggests that molecular structure of hydrolysis with Cl in aqueous phase may be more stable than that of Cl ionically bonding with the resin. This result may offer physico-chemical insights into behavior and fate of the pollutants.

  16. Exposure to polycyclic aromatic hydrocarbons with special focus on cancer

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2015-03-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are a group of compounds consisting of two or more fused aromatic rings. Most of them are formed during incomplete combustion of organic materials such as wood and fossil fuels, petroleum products, and coal. The composition of PAH mixtures varies with the source and is also affected by selective weathering effects in the environment. PAHs are ubiquitous pollutants frequently found in a variety of environments such as fresh water and marine sediments, the atmosphere, and ice. Due to their widespread distribution, the environmental pollution due to PAHs has aroused global concern. Many PAHs and their epoxides are highly toxic, mutagenic and/or carcinogenic to microorganisms as well as to higher forms of life including humans. The main aim of this review is to provide contemporary information on PAH sources, route of exposure, worldwide emission rate, and adverse effects on humans, especially with reference to cancer.

  17. Air Pollution and the skin

    Directory of Open Access Journals (Sweden)

    Eleni eDrakaki

    2014-05-01

    Full Text Available The increase of air pollution over the years has major effects on the human skin. The skin is exposed to ultraviolet radiation (UVR and environmental air pollutants such as polycyclic aromatic hydrocarbons (PAHs, volatile organic compounds (VOCs, oxides, particulate matter (PM, ozone (O3 and cigarette smoke. Although human skin acts as a biological shield against pro-oxidative chemical and physical air pollutants, the prolonged or repetitive exposure to high levels of these pollutants may have profound negative effects on the skin. Exposure of the skin to air pollutants has been associated with skin aging and inflammatory or allergic skin conditions such as atopic dermatitis, eczema, psoriasis or acne, while skin cancer is among the most serious effects. On the other hand, some air pollutants (ie, ozone, nitrogen dioxide, and sulfur dioxide and scattering particulates (clouds and soot in the troposphere reduce the effects of shorter wavelength UVR and significant reductions in UV irradiance have been observed in polluted urban areas.

  18. Contorted polycyclic aromatics.

    Science.gov (United States)

    Ball, Melissa; Zhong, Yu; Wu, Ying; Schenck, Christine; Ng, Fay; Steigerwald, Michael; Xiao, Shengxiong; Nuckolls, Colin

    2015-02-17

    CONSPECTUS: This Account describes a body of research in the design, synthesis, and assembly of molecular materials made from strained polycyclic aromatic molecules. The strain in the molecular subunits severely distorts the aromatic molecules away from planarity. We coined the term "contorted aromatics" to describe this class of molecules. Using these molecules, we demonstrate that the curved pi-surfaces are useful as subunits to make self-assembled electronic materials. We have created and continue to study two broad classes of these "contorted aromatics": discs and ribbons. The figure that accompanies this conspectus displays the three-dimensional surfaces of a selection of these "contorted aromatics". The disc-shaped contorted molecules have well-defined conformations that create concave pi-surfaces. When these disc-shaped molecules are substituted with hydrocarbon side chains, they self-assemble into columnar superstructures. Depending on the hydrocarbon substitution, they form either liquid crystalline films or macroscopic cables. In both cases, the columnar structures are photoconductive and form p-type, hole- transporting materials in field effect transistor devices. This columnar motif is robust, allowing us to form monolayers of these columns attached to the surface of dielectrics such as silicon oxide. We use ultrathin point contacts made from individual single-walled carbon nanotubes that are separated by a few nanometers to probe the electronic properties of short stacks of a few contorted discs. We find that these materials have high mobility and can sense electron-deficient aromatic molecules. The concave surfaces of these disc-shaped contorted molecules form ideal receptors for the molecular recognition and assembly with spherical molecules such as fullerenes. These interfaces resemble ball-and-socket joints, where the fullerene nests itself in the concave surface of the contorted disc. The tightness of the binding between the two partners can be

  19. Sorption capacities of graphitzed carbon black in determination of chlorinate pesticide traces in water

    Energy Technology Data Exchange (ETDEWEB)

    Bacaloni, A.; Goretti, G.; Lagana, A.; Petronio, B.M.; Rotatori, M.

    1980-11-01

    The use of graphitized carbon black (GCB) to extract trace organic pollutants from water is analyzed. Adsorbent materials such as GCB or Tenax can be used to determine low concentrations of organic pollutants in water. The adsorption ability of GCB vs. that of Tenax was tested with 51 different compounds including alcohols, acids, phenols, ethers, hydrocarbons,and PCB's at concentrations ranging from 5 ppb to 200 ppb. Chlorinated pesticides were among the compounds that were entirely adsorbed. Although the adsorbent efficiences depend on the nature of other substances in the water samples, GCB proves to be better than Tenax for pesticide determinations. (6 graphs, 17 references, 4 tables)

  20. 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,…

  1. Fluorinated aromatic diamine

    Science.gov (United States)

    Jones, Robert J. (Inventor); O'Rell, Michael K. (Inventor); Hom, Jim M. (Inventor)

    1980-01-01

    This invention relates to a novel aromatic diamine and more particularly to the use of said diamine for the preparation of thermally stable high-molecular weight polymers including, for example, polyamides, polyamideimides, polyimides, and the like. This diamine is obtained by reacting a stoichometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloronitrobenzene to obtain an intermediate, 2,2-bis[4-(4-nitrophenoxy)phenyl] hexafluoropropane, which is reduced to the corresponding 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane.

  2. Petrochemistry - Aromatics; Petrochimie - Aromatiques

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-09-01

    The assignment of Unipetrol chemical activities to the Czech group Agrofert by the Polish PKN Orlen is suspended and would be renegotiated. Oman Oil Company (OOC) is joining in the Korean LG International and in its subsidiary company Oman Refinery Company (ORC) for the construction of its new aromatics complex on its site of Sohar (Oman). This plan represents an investment of one milliard of dollars; it will produce 800000 t/year of para-xylene and 210000 t/year of benzene. The unit would be operational at the third trimester 2008. (O.M.)

  3. Electron affinity of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Babcock, L.M.; Pentecost, T.; Koppenol, W.H. (Louisiana State Univ., Baton Rouge (USA))

    1989-12-14

    The flowing afterglow technique was used to determine the electron affinity of chlorine dioxide. A value of 2.37 {plus minus} 0.10 eV was found by bracketing between the electron affinities of HS* and SF{sub 4} as a lower limit and that of NO{sub 2} as an upper limit. This value is in excellent agreement with 2.32 eV predicted from a simple thermodynamic cycle involving the reduction potential of the ClO{sub 2}/ClO{sub 2}{sup {minus}} couple and a Gibbs hydration energy identical with that of SO{sub 2}{sup {sm bullet}{minus}}.

  4. Petroleum hydrocarbons, fluorescent aromatic compounds in fish bile and organochlorine pesticides from areas surrounding the spill of the Kab121 well, in the Southern Gulf of Mexico: a case study.

    Science.gov (United States)

    Gold-Bouchot, G; Ceja-Moreno, V; Chan-Cocom, E; Zapata-Perez, O

    2014-01-01

    In October 2007, a light crude oil spill took place in the off shore Kab121 oil well, 32 km north of the mouth of the Grijalva River, Tabasco, Mexico. In order to estimate the possible effects of oil spill on the biota in the area surrounding the spilled well, the level of different fractions of petroleum hydrocarbons were measured in fish, as well as the concentration of some chlorinated hydrocarbons and PCBs. The organisms examined were cat fish (Ariopsis felis), in addition fluorescent aromatic compounds in bile, the contaminants above mentioned and their relationship with cyotochrome P-450 and Ethoxyresorufin-O-deethylase, Glutathion-S-Transferase and catalase activities in liver were determined. The concentration of most pollutants were low, except PAHs. Spatial distribution of these compounds, as well as most biomarkers, reflected the highest exposure of fish to pollutants in the area adjacent to well, as well as in the proximity of rivers. The profile of exposure to this environment was chronic in nature and not temporary.

  5. Polycyclic Aromatic Hydrocarbons and Heavy Metals in Kostrena Coastal Area

    OpenAIRE

    Tomić Linšak, Dijana; Linšak, Željko; Bešić, Denis; Vojčić, Nina; Teležar, Mirna; Čoklo, Miran; Šušnić, Saša; Mićović, Vladimir

    2011-01-01

    The aim of this study was to determine pollution by polycyclic aromatic hydrocarbons (PAH) and heavy metals in seawater and sediment in Kostrena coastal area, as well as their toxicity using bioluminescence based tests. Total PAH concentration in seawater ranged 1.7-155.3 ng/L. The share of carcinogenetic PAH was relatively high, ranging 22–48.3%. Nickel concentrations in seawater were beyond detection limits (

  6. Solvent extraction of chlorinated compounds from soils and hydrodechlorination of the extract phase.

    Science.gov (United States)

    Murena, Fabio; Gioia, Francesco

    2009-03-15

    The remediation of soils contaminated with chlorinated compounds was investigated. The process consists of solvent extraction followed by catalytic hydroprocessing (hydrodechlorination) of the extract phase. A mixture of ethylacetate-acetone-water (E-A-W) was adopted as solvent in the extraction process. Tests of extraction of chlorobenzene from a model contaminated soil were carried out and the Langmuir adsorption equation was characterized. The solvent, contaminated with different chlorinated compounds was then hydrotreated with a Pd/C catalyst. The chlorinated compounds tested are: chlorobenzene, hexachlorobenzene and hexachloroethane at various initial concentrations. The reaction runs were carried out at room temperature and at a hydrogen pressure of 1bar. Hydrotreating of these compounds takes place according to a Langmuir-Hinshelwood mechanism whose kinetic parameters were determined. The experiments show that high destruction efficiencies may be reached in reasonably short times, particularly for hexachloroethane. Longer times are necessary for the aromatic compounds (chlorobenzene and hexachlorobenzene) for which the CCl bond is much stronger than that in the aliphatic compound. Time for a 95% destruction efficiency for all experimental runs was determined. A noteworthy finding is that ethylacetate and acetone do not undergo any reaction during hydrotreating. Thus the treated extract solution may be recycled inasmuch as it conserves its full extracting capacity towards chlorinated compounds. A limitation in recycling is the inhibiting effect of benzene on the HDCl rate: benzene produced by HDCl of chlorinated compounds, accumulates in the solvent mixture in the event of recycling. Simulation of the process with the recycling of the solvent was carried out, accounting for the inhibiting effect of benzene.

  7. Phosphate valorization by dry chlorination route

    OpenAIRE

    Kanari N.; Menad N.; Diot F.; Allain E.; Yvon J.

    2016-01-01

    International audience; 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 (Ca 2 P 2 O 7), is subjected to reactions with Cl 2 +CO+N 2 and Cl 2 +C+N 2 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 ...

  8. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    Directory of Open Access Journals (Sweden)

    Farai eMaphosa

    2012-10-01

    Full Text Available Organohalide compounds such as chloroethenes, chloroethanes and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides and petroleum derivatives. Microbial bioremediation of contaminated sites, has become commonplace whereby key processes involved in bioremediation include anaerobic degradation and transformation of these organohalides by organohalide respiring bacteria and also via hydrolytic, oxygenic and reductive mechanisms by aerobic bacteria. Microbial ecogenomics has enabled us to not only study the microbiology involved in these complex processes but also develop tools to better monitor and assess these sites during bioremediation. Microbial ecogenomics have capitalized on recent advances in high-throughput and -output genomics technologies in combination with microbial physiology studies to address these complex bioremediation problems at a system level. Advances in environmental metagenomics, transcriptomics and proteomics have provided insights into key genes and their regulation in the environment. They have also given us clues into microbial community structures, dynamics and functions at contaminated sites. These techniques have not only aided us in understanding the lifestyles of common organohalide respirers, for example Dehalococcoides, Dehalobacter and Desulfitobacterium, but also provided insights into novel and yet uncultured microorganisms found in organohalide respiring consortia. In this paper we look at how ecogenomic studies have aided us to understand the microbial structures and functions in response to environmental stimuli such as the presence of chlorinated pollutants.

  9. 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 ...

  10. 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 ...

  11. Degradation of aromatic compounds in plants grown under aseptic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mithaishvili, T.; Ugrekhelidze, D.; Tsereteli, B.; Sadunishvili, T.; Kvesitadze, G. [Durmishidze Inst. of Biochemistry and Biotechnology, Academy of Sciences of Georgia, Tbilisi (Georgia); Scalla, R. [Lab. des Xenobiotiques, INRA, Toulouse (France)

    2005-02-01

    The aim of the work is to investigate the ability of higher plants to absorb and detoxify environmental pollutants - aromatic compounds via aromatic ring cleavage. Transformation of {sup 14}C specifically labelled benzene derivatives, [1-6-{sup 14}C]-nitrobenzene, [1-6-{sup 14}C]-aniline, [1-{sup 14}C]- and [7-{sup 14}C]-benzoic acid, in axenic seedlings of maize (Zea mays L.), kidney bean (Phaseolus vulgaris L.), pea (Pisum sativum L.) and pumpkin (Cucurbita pepo L.) were studied. After penetration in plants, the above xenobiotics are transformed by oxidative or reductive reactions, conjugation with cell endogenous compounds, and binding to biopolymers. The initial stage of oxidative degradation consists in hydroxylation reactions. The aromatic ring can then be cleaved and degraded into organic acids of the Krebs cycle. Ring cleavage is accompanied by {sup 14}CO{sub 2} evolution. Aromatic ring cleavage in plants has thus been demonstrated for different xenobiotics carrying different substitutions on their benzene ring. Conjugation with low molecular peptides is the main pathway of aromatic xenobiotics detoxification. Peptide conjugates are formed both by the initial xenobiotics (except nitrobenzene) and by intermediate transformation products. The chemical nature of the radioactive fragment and the amino acid composition of peptides participating in conjugation were identified. (orig.)

  12. "Carbo-aromaticity" and novel carbo-aromatic compounds.

    Science.gov (United States)

    Cocq, Kévin; Lepetit, Christine; Maraval, Valérie; Chauvin, Remi

    2015-09-21

    While the concept of aromaticity is being more and more precisely delineated, the category of "aromatic compounds" is being more and more expanded. This is illustrated by an introductory highlight of the various types of "aromaticity" previously invoked, and by a focus on the recently proposed "aromatic character" of the "two-membered rings" of the acetylene and butatriene molecules. This serves as a general foundation for the definition of "carbo-aromaticity", the relevance of which is surveyed through recent results in the synthetic, physical, and theoretical chemistry of carbo-mers and in particular macrocyclic-polycyclic representatives constituting a natural family of "novel aromatic compounds". With respect to their parent molecules, carbo-mers are constitutionally defined as "carbon-enriched", and can also be functionally regarded as "π-electron-enriched". This is exemplified by recent experimental and theoretical results on functional, aromatic, rigid, σ,π-macrocyclic carbo-benzene archetypes of various substitution patterns, with emphasis on the quadrupolar pattern. For the purpose of comparison, several types of non-aromatic references of carbo-benzenes are then considered, i.e. freely rotating σ,π-acyclic carbo-n-butadienes and flexible σ-cyclic, π-acyclic carbo-cyclohexadienes, and to "pro-aromatic" congeners, i.e. rigid σ,π-macrocyclic carbo-quinoids. It is shown that functional carbo-mers are entering the field of "molecular materials" for properties such as linear or nonlinear optical properties (e.g. dichromism and two-photon absorption) and single molecule conductivity. Since total or partial carbo-mers of aromatic carbon-allotropes of infinite size such as graphene (graphynes and graphdiynes) and graphite ("graphitynes") have long been addressed at the theoretical or conceptual level, recent predictive advances on the electrical, optical and mechanical properties of such carbo-materials are surveyed. Very preliminary experimental results

  13. Inhibitory effects of polycyclic aromatic hydrocarbons (PAHs) on photosynthetic performance are not related to their aromaticity.

    Science.gov (United States)

    Jajoo, Anjana; Mekala, Nageswara Rao; Tomar, Rupal Singh; Grieco, Michele; Tikkanen, Mikko; Aro, Eva-Mari

    2014-08-01

    Polycyclic aromatic hydrocarbons (PAHs) are very toxic and highly persistent environmental pollutants which accumulate in soil and affect growth of the plants adversely. This study aims to investigate inhibitory effects of 3 major PAH particularly on photosynthetic processes in Arabidopsis thaliana grown in soil treated with PAH. The 3 PAH chosen differ from each other in aromaticity (number of rings) comprising their structure (2 rings: naphthalene, 3 rings: anthracene and 4 rings: pyrene). Several growth parameters and Chlorophyll a fluorescence was monitored in PAH treated plants. BN-PAGe analysis was done in order to get information about change in the protein conformation. PAH treatment led to increased value of Fo which collaborated with increase in the amount of free LHC as seen through BN-Page analysis. Thus PAH were found to inhibit PS II photochemistry and caused distinct change in pigment composition. However the results led us to infer that 3-ring anthracence is more inhibitory as compared to 2-ring naphthalene and 4-ring pyrene. This indicates that aromaticity of PAH is unrelated to their response on photosynthetic processes.

  14. Influence of long-range atmospheric transportation (LRAT) on mono-to octa-chlorinated PCDD/Fs levels and distributions in soil around Qinghai Lake, China

    DEFF Research Database (Denmark)

    Han, Ying; Liu, Wenbin; Hansen, Hans Chr. Bruun

    2016-01-01

    Long-range atmospheric transportation (LRAT) of persistent organic pollutants followed by their deposition in cold, arid regions is of wide concern. This problem occurs at Qinghai Lake in the northeastern Tibetan Plateau, a sparsely populated area with extreme weather conditions and little current...... or historical anthropogenic pollution. The concentrations and distribution patterns of the mono-to octa-chlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) congeners in surface soil samples collected from around Qinghai Lake were quantified. Concentration differences between low-(mono-to tri-) chlorinated...

  15. 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.

  16. 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.

  17. Chlorine Salts at the Phoenix Landing Site

    Science.gov (United States)

    Hanley, J.; Horgan, B.

    2016-09-01

    Although chlorine salts (perchlorates, chlorides) are known to exist at the Phoenix landing site, their distribution and type have not been positively identified yet. We look for these salts through a novel NIR remote sensing technique.

  18. Phytoremediation: a technology using green plants to remove contaminants from polluted areas.

    Science.gov (United States)

    Garbisu, Carlos; Hernández-Allica, Javier; Barrutia, Oihana; Alkorta, Itziar; Becerril, José M

    2002-01-01

    Phytoremediation is an emerging cost-effective, non-intrusive, esthetically pleasing, and low cost technology using the remarkable ability of plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues. Phytoremediation technology is applicable to a broad range of contaminants, including metals and radionuclides, as well as organic compounds like chlorinated solvents, polychlorobiphenyls, polycyclic aromatic hydrocarbons, pesticides/insecticides, explosives, and surfactants. The use of plants to transport and concentrate metals from the soil into the harvestable parts of roots and above-ground shoots, usually called 'phytoextraction', has appeared on the scene as a valid alternative to traditional physicochemical remediation methods that do not provide acceptable solutions for the removal of metals from soils. Positive results are becoming available regarding the ability of plants to degrade certain organic compounds. Nonetheless, despite the firm establishment of phytoremediation technology in the literature and in extensive research study and in small-scale demonstrations, full-scale applications are currently limited to a small number of projects. At present, the phytoremediation of metal pollutants from the environment could be approaching commercialization.

  19. Electric arc furnaces for steel-making: hot spots for persistent organic pollutants.

    Science.gov (United States)

    Odabasi, Mustafa; Bayram, Abdurrahman; Elbir, Tolga; Seyfioglu, Remzi; Dumanoglu, Yetkin; Bozlaker, Ayse; Demircioglu, Hulusi; Altiok, Hasan; Yatkin, Sinan; Cetin, Banu

    2009-07-15

    Persistent organic pollutant (POP) concentrations were measured in stack-gases of ferrous scrap processing steel plants with electric arc furnaces (EAFs) (n = 5) in Aliaga, Izmir, Turkey and in air (n = 11) at a site near those plants. Measured stack-gas concentrations for the four plants without scrap preheating (611 +/- 311, 165,000 +/- 285,000, and 33 +/- 3 ng m(-3), average +/- SD for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively) indicated that they are significant sources for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). POP emissions from the plant with scrap preheating were significantly higher (13 500, 445 000, and 91 ng m(-3) for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively). It was also shown that the steel plants emit considerable amounts of fugitive POPs in particle-phase. Estimated emissions using the emission factors generated in this study and the production amounts suggested that the steel plants with EAFs may significantly contribute to local and global PAH, PCB, and PBDE emissions. Several other compounds (aromatic and aliphatic hydrocarbons, oxygen, sulfur, nitrogen, and chlorine-containing organic compounds, n = 49) were identified and determined semiquantitatively in the stack-gas and ambient air samples. Ambient air concentrations (62 +/- 35, 320 +/- 134 ng m(-3), 1451 +/- 954 pg m(-3), for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively) were significantly higher than those measured previously around the world and in the region, further confirming that the steel plants with EAFs are "hot spots" for POPs.

  20. Modeling Trihalomethane Formation Potential from Wastewater Chlorination

    Science.gov (United States)

    1994-09-01

    chemically with each other, and with living organisms, particularly bacteria ( Manahan , 1991:435). To ensure effective disinfection, to meet the CWA...halogens are strong oxidants and are highly reactive ( Manahan , 1991:504). Chlorine is never found uncombined in nature, it exists only as the...HOCI) according to the following reaction: Cl2 (gas) + H20 =• HOC1 + H+ + Cl The hydrogen is oxidized and the chlorine gas is reduced ( Manahan , 1991

  1. 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.

  2. 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.

  3. Enviormental Pollution

    OpenAIRE

    Kanika Saini; Dr. Sona Malhotra

    2016-01-01

    Environment Pollution is one of the greatest problems today which is increasing with every passing year and causing crucial and severe damage to the earth. It has become a real problem since the beginning of the industrial revolution. It is the contamination of physical and biological components of the Earth / atmosphere system to such an extent that normal environmental processes are harmed. Pollution of the environment consists of five main types of pollution, namely air, water,...

  4. Initial microbial degradation of polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Milić Jelena

    2016-01-01

    Full Text Available The group of polycyclic aromatic hydrocarbons (PAHs are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas. [Projekat Ministarstva nauke Republike Srbije, br. III43004

  5. A new kind of Molotov? Gasoline-pool chlorinator mixtures.

    Science.gov (United States)

    Hutches, Katherine; Lord, James

    2012-07-01

    This paper investigates the reaction between pool chlorinators and gasoline. In particular, the propensity for self-ignition and the resulting chemical products were studied. An organic pool chlorinator was combined with gasoline in varying proportions in an attempt to form a hypergolic mixture. None of the combinations resulted in self-ignition, but larger quantities of chlorinator produced vigorous light-colored smoke and a solid mass containing isocyanuric acid and copper chloride. Additionally, the chlorinating abilities of different commercially available pool chlorinators were explored. When Ca(ClO)(2) and sodium dichloro-s-triazinetrione-based chlorinators were used, the presence of gasoline was still visible after 10 days, despite limited chlorination. The trichloro-s-triazinetrione-based chlorinator, however, caused efficient chlorination of the C(2)- and C(3)-alkylbenzenes, making gasoline no longer identifiable.

  6. [Chlorination byproducts formation potentials of typical nitrogenous organic compounds in water].

    Science.gov (United States)

    Xu, Qian; Xu, Bin; Qin, Cao; Xia, Sheng-Ji; Gao, Nai-Yun; Tian, Fu-Xiang; Li, Da-Peng

    2011-07-01

    Twelve typical nitrogenous organic compounds including herbicides, pesticides, amino acids, industrial products etc in polluted raw water were selected to investigate formation of typical carbonaceous and nitrogenous DBPs during chlorination and chloramination. To indentify the formation mechanism of carbonaceous and nitrogenous disinfection byproducts from nitrogenous chemicals, chlorination and chloroamination of urea herbicides, triazine herbicides, amino acid, and other compounds were investigated. As a result, the potential precursors for different DBPs were defined as well. It has been identified that widely used urea herbicides could produce as many as 9 specific DBPs. The chlorotoluron shows highest reactivity and yields chloroform (CF), monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), 1,1-dichloro-acetone (1,1-DCP), 1,1,1-trichloro-acetone (1,1,1-TCP), chloropicrin (NTCM), dichloro-acetonitrile (DCAN), dimethylnitrosamine (NDMA). The results indicated that aldicarb and dinoseb are important precursors of CF, DCAA, MCAA, NTCM as well. High concentrations of CF and DCAA were found during L-tryptophan chlorination. Furthermore, DBPs formation pathways and mechanisms were suggested during chlorination and chloramination of chlorotoluron, ametryn, dinoseb L-tryptophan.

  7. Maxillofacial prostheses of chlorinated polyethylene.

    Science.gov (United States)

    May, P D

    1978-05-01

    There is clearly a need for maxillofacial prosthetic materials with improved properties. The chlorinated polyethylenes are thermoplastic elastomers which have particularly promising properties, and were used by us to prepare improved maxillofacial prostheses. Suitable CPE resins were compounded with other polymers and with pigments on a heated rubber mill to form thin sheets in a variety of shades. These were heated at 190 degrees C for 10 min and placed between heated linotype mold halves. The prosthesis was formed in a hand press. Sometimes heating and pressing were repeated. After cooling in water, the prosthesis was removed and hand-shaded with oil-soluble dyes. Physical properties were evaluated using standard techniques; skin irritation studies were conducted by 14-day insult patch tests on rabbits. Clinical evaluations were conducted on human volunteers. Parallel evaluations were conducted on commerically available materials for comparison. The CPE was superior to all of the three commerical materials in most properties, and comparable to the better of the three in the remaining properties. On balance, CPE was significantly superior. Early results indicate that the materials and techniques required are easily handled in the dental lab and that the final prosthesis has excellent aesthetic and patient acceptability.

  8. Chlorine Abundances in Cool Stars

    CERN Document Server

    Maas, Z G; Hinkle, K

    2016-01-01

    Chlorine abundances are reported in 15 evolved giants and one M dwarf in the solar neighborhood. The Cl abundance was measured using the vibration-rotation 1-0 P8 line of H$^{35}$Cl at 3.69851 $\\mu$m. The high resolution L-band spectra were observed using the Phoenix infrared spectrometer on the Kitt Peak Mayall 4m telescope. The average [$^{35}$Cl/Fe] abundance in stars with --0.72$<$[Fe/H]$<$0.20 is [$^{35}$Cl/Fe]=(--0.10$\\pm$0.15) dex. The mean difference between the [$^{35}$Cl/Fe] ratios measured in our stars and chemical evolution model values is (0.16$\\pm$0.15) dex. The [$^{35}$Cl/Ca] ratio has an offset of $\\sim$0.35 dex above model predictions suggesting chemical evolution models are under producing Cl at the high metallicity range. Abundances of C, N, O, Si, and Ca were also measured in our spectral region and are consistent with F and G dwarfs. The Cl versus O abundances from our sample match Cl abundances measured in planetary nebula and \\ion{H}{2} regions. In one star where both H$^{35}$Cl a...

  9. Rapeseed lecithin hydroxylation by chlorine replacing with hydroxyl groups in chlorinated phospholipids.

    Science.gov (United States)

    Górecki, Michał; Sosada, Marian; Boryczka, Monika; Fraś, Pawel; Pasker, Beata

    2012-01-01

    Rapeseed lecithin ethanol soluble fraction (LESF) was hydroxylated with 30% hydrogen peroxide in the presence of acetic acid. The product was compared to the one obtained by method based on nucleophilic substitution reaction of phospholipids chlorine derivatives. In this approach, hydrogen chloride was added to double bonds in unsaturated acyl groups of phospholipids. Next, chlorine was replaced with hydroxyl groups via the alkaline hydrolysis of chlorine derivatives. The surface active properties of the products obtained with the usage of two methods of rapeseed LESF hydroxylation were determined. The minimal surface tension (eta(min), mN/m) and the critical micelle concentration (CMC, g/L) of LESF hydroxylated with hydrogen peroxide (20.2 mN/m, 6.0 g/L) and obtained by chlorine replacing with hydroxyl groups in chlorinated phospholipids (25.0 mN/m, 9.8 g/L) were compared to LESF (31.8 mN/m, 17.8 g/L). Hydroxylated LESF obtained by lecithin chlorination and chlorine replacing with hydroxyl groups in the chlorine derivatives has no peroxides and the good surface active properties. The product as an effective emulsifier can be used in pharmacy and cosmetics.

  10. Bromate ion formation in dark chlorination and ultraviolet/chlorination processes for bromide-containing water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Bormate (BrO3-) is a carcinogenic chemical produced in ozonation or chlorination of bromide-containing water. Although its formation in seawater with or without sunlight has been previously investigated, the formation of bromate in dilute solutions,particularly raw water for water treatment plant, is unknown. In this article, the results of bench scale tests to measure the formation rates of bromate formation in dilute solutions, including de-ionized water and raw water from Yangtze River, were presented in dark chlorination and ultraviolet (UV)/chlorination processes. And the effects of initial pH, initial concentration of NaOCl, and UV light intensity on bromate formation in UV/chlorination of the diluted solutions were investigated. Detectable bromate was formed in dark chlorination of the two water samples with a relatively slow production rate. Under routine disinfecting conditions, the amount of formed bromate is not likely to exceed the national standards (10 μg/L). UV irradiation enhanced the decay of free chlorine, and,simultaneously, 6.6%-32% of Br- was oxidized to BrO3-. And the formation of bromate exhibited three stages: rapid stage, slow stage and plateau. Under the experimental conditions (pH = 4.41-11.07, CCl2= 1.23-4.50 mg/L), low pH and high chlorine concentration favored the generation of bromate. High light intensity promoted the production rate of bromate, but decreased its total generation amount due to acceleration of chlorine decomposition.

  11. 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.

  12. 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 extra

  13. On Pollution

    Institute of Scientific and Technical Information of China (English)

    刘磊

    2005-01-01

    Long long ago,our world was very beautiful, there were trees, flowers,rivers ... they were very clean and tidy.But now, the hillsarenrt green, the rivers aren't clean,the fish has died. Pollution is becoming more and more serious all over the world. We are living in a polluted environment which is bad forour health.

  14. Advances towards aromatic oligoamide foldamers

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Plesner, Malene; Dissing, Mette Marie

    2014-01-01

    -ray crystallographic analysis of two of these dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a comparatively more closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation with a more open, extended structure...... of the surrounding aromatic backbone. Investigation of the X-ray structures of two arylopeptoid dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation...

  15. Chlorine dioxide treatment for zebra mussel control

    Energy Technology Data Exchange (ETDEWEB)

    Rybarik, D. [Dairyland Power Cooperative, La Crosse, WI (United States); Byron, J. [Nalco Chemical Company, Naperville, IL (United States); Germer, M. [Rio Linda Chemical Company, Sacramento, CA (United States)

    1995-06-01

    Chlorine is recognized and commonly used biocide for power plant cooling water and service water treatment programs, including the control of zebra mussels. Chlorine dioxide has recently become a popular method of zebra mussel control because of its economy, safety, environmental acceptability, and effectiveness when compared to other mussel control methods. This control technique was recently demonstrated at Dairyland Power Cooperative`s Alma Generating Station on the east bank of the upper Mississippi River in Alma, Wisconsin. The project was assisted with EPRI Tailored Collaboration Program funds. The Dairyland Power Alam Generating Station consists of five generating units that utilize raw, untreated Mississippi River water for condenser, circulating, and service water supplies. The first units were built in 1947, with the final and largest unit being completed in 1960. Total station generating capacity is 200 MW. Because of recent increases in the zebra mussel density at the station intake, Dairyland Power selected the team of Nalco and Rio Linda to perform a chlorine dioxide treatment of the station`s new water systems to eradicate and control the mussels before their presence created operational difficulties. This paper will present the results of the treatment including treatment theory, design and construction of the treatment system, the method of chlorine dioxide generation, treatment concentration, analytical methods o monitoring chlorine dioxide generation, residuals and trihalomethane (THM) concentrations, protocol for monitoring treatment mortality, and the effects of chlorine dioxide and detoxification on other water chemistry parameters and equipment materials. The goal of this paper is to inform and assist users with establishing consistent and uniform practices for safely utilizing and monitoring chlorine dioxide in the eradication and control of zebra mussels.

  16. Key Factors Controlling the Applicability and Efficiency of Bioremediation of Chlorinated Ethenes In Situ

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2012-12-01

    Bioremediation has been considered as one of environmentally friendly and cost effective approaches for cleaning up the sites polluted by organic contaminants, such as chlorinated ethenes. Although bioremediation, in its widest sense, is not new, and many researches have been performed on bioremediation of different kinds of pollutants, an effective design and implication of in situ bioremediation still remains a challenging problem because of the complexity. Many factors may affect the applicability and efficiency of bioremediation of chlorinated ethenes in situ, which include the type and concentration of contaminants, biological, geological and hydro-geological conditions of the site, physical and chemical characteristics of groundwater and soils to be treated, as well as the constraints in engineering. In this presentation, an overview together with a detailed discussion on each factor will be provided. The influences of individual factors are discussed using the data obtained or cited from different sites and experiments, and thus under different environmental conditions. The results of this study illustrated that 1) the establishment of microbial consortium is of crucial importance for a complete degradation of chlorinated ethenes, 2) in situ control of favorable conditions for increasing microbial activities for bio-degradation through a designed pathway is the key to success, 3) the focus of a successful remediation system is to design an effective delivery process that is capable of producing adequate amendment mixing of contaminant-degrading bacteria, appropriate concentrations of electron acceptors, electron donors, and microbial nutrients in the subsurface treatment area.

  17. Influencing factors and degradation products of antipyrine chlorination in water with free chlorine

    Institute of Scientific and Technical Information of China (English)

    Meiquan Cai; Liqiu Zhang; Fei Qi; Li Feng

    2013-01-01

    Owing to its low cost,free chlorine is one of the most common disinfectants for wastewater and drinking water treatment.However,the formation of disinfection byproducts has been found to occur after free chlorine disinfection in recent decades.Antipyrine (ANT),an anti-inflammatory analgesic,has been frequently detected in the aquatic environment.In this work.the removal efficiency of ANT by free chlorine oxidation in ultrapure water was investigated with batch experiments.The influencing factors on the removal of ANT were explored at initial concentrations of ANT from 0.04 to 0.64 mg/L,free chlorine dosage from 0.30 to 1.31 mg/L,and pH from 1.5 to 9.0.The main degradation products were identified by solid phase extraction-gas chromatography-mass spectrometry.The results showed that ANT reacted rapidly with free chlorine in ultrapure water systems and up to 90.6% removal efficiency of ANT was achieved after 25 sec (initial free chlorine 1 mg/L,ANT 0.5 mg/L,pH 7.0).Higher oxidant dosage,lower ANT initial concentration and low pH favor the ANT removal.The main degradation product in ANT chlorination was a monochlorine substitution product (4-chloro-l,2-dihydro1,5-dimethyl-2-phenyl-3H-pyrazol-3-one),which can be further chlorinated by free chlorine.In addition,the total organic carbon result indicated that ANT is difficult to be mineralized using chlorine.

  18. Influencing factors and degradation products of antipyrine chlorination in water with free chlorine.

    Science.gov (United States)

    Cai, Meiquan; Zhang, Liqiu; Qi, Fei; Feng, Li

    2013-01-01

    Owing to its low cost, free chlorine is one of the most common disinfectants for wastewater and drinking water treatment. However, the formation of disinfection byproducts has been found to occur after free chlorine disinfection in recent decades. Antipyrine (ANT), an anti-inflammatory analgesic, has been frequently detected in the aquatic environment. In this work, the removal efficiency of ANT by free chlorine oxidation in ultrapure water was investigated with batch experiments. The influencing factors on the removal of ANT were explored at initial concentrations of ANT from 0.04 to 0.64 mg/L, free chlorine dosage from 0.30 to 1.31 mg/L, and pH from 1.5 to 9.0. The main degradation products were identified by solid phase extraction-gas chromatography-mass spectrometry. The results showed that ANT reacted rapidly with free chlorine in ultrapure water systems and up to 90.6% removal efficiency of ANT was achieved after 25 sec (initial free chlorine 1 mg/L, ANT 0.5 mg/L, pH 7.0). Higher oxidant dosage, lower ANT initial concentration and low pH favor the ANT removal. The main degradation product in ANT chlorination was a monochlorine substitution product (4-chloro-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one), which can be further chlorinated by free chlorine. In addition, the total organic carbon result indicated that ANT is difficult to be mineralized using chlorine.

  19. Degradation of sulfamethoxazole using ozone and chlorine dioxide - Compound-specific stable isotope analysis, transformation product analysis and mechanistic aspects.

    Science.gov (United States)

    Willach, Sarah; Lutze, Holger V; Eckey, Kevin; Löppenberg, Katja; Lüling, Michelle; Terhalle, Jens; Wolbert, Jens-Benjamin; Jochmann, Maik A; Karst, Uwe; Schmidt, Torsten C

    2017-10-01

    The sulfonamide antibiotic sulfamethoxazole (SMX) is a widely detected micropollutant in surface and groundwaters. Oxidative treatment with e.g. ozone or chlorine dioxide is regularly applied for disinfection purposes at the same time exhibiting a high potential for removal of micropollutants. Especially for nitrogen containing compounds such as SMX, the related reaction mechanisms are largely unknown. In this study, we systematically investigated reaction stoichiometry, product formation and reaction mechanisms in reactions of SMX with ozone and chlorine dioxide. To this end, the neutral and anionic SMX species, which may occur at typical pH-values of water treatment were studied. Two moles of chlorine dioxide and approximately three moles of ozone were consumed per mole SMX degraded. Oxidation of SMX with ozone and chlorine dioxide leads in both cases to six major transformation products (TPs) as revealed by high-resolution mass spectrometry (HRMS). Tentatively formulated TP structures from other studies could partly be confirmed by compound-specific stable isotope analysis (CSIA). However, for one TP, a hydroxylated SMX, it was not possible by HRMS alone to identify whether hydroxylation occurred at the aromatic ring, as suggested in literature before, or at the anilinic nitrogen. By means of CSIA and an analytical standard it was possible to identify sulfamethoxazole hydroxylamine unequivocally as one of the TPs of the reaction of SMX with ozone as well as with chlorine dioxide. H-abstraction and electron transfer at the anilinic nitrogen are suggested as likely initial reactions of ozone and chlorine dioxide, respectively, leading to its formation. Oxidation of anionic SMX with ozone did not show any significant isotopic fractionation whereas the other reactions studied resulted in a significant carbon isotope fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Potent inhibition of estrogen sulfotransferase by hydroxylated metabolites of polyhalogenated aromatic hydrocarbons reveals alternative mechanism for estrogenic activity of endocrine disrupters

    NARCIS (Netherlands)

    M.H.A. Kester (Monique); T.J. Visser (Theo); S. Bulduk; H. van Toor (Hans); D. Tibboel (Dick); W. Meinl; H. Glatt; C.N. Falany; M.W. Coughtrie; A.G. Schuur; A. Brouwer (Abraham)

    2002-01-01

    textabstractPolyhalogenated aromatic hydrocarbons (PHAHs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenylethers, and bisphenol A derivatives are persistent environmental pollutants, which are capable of interfering with reproductive and endocri

  1. Activated carbon adsorption-advanced electro-oxidative regeneration for the treatment of biorefractory organic pollutants

    Institute of Scientific and Technical Information of China (English)

    ZHOU Minghua; DAI Qizhou; LEI Lecheng; WANG Dahui

    2005-01-01

    The wastewater containing toxic and biorefractory pollutants such as aromatic compounds cannot be treated by conventional action due to their toxicity and structure stability, which has been one of the key technical difficulties in wastewater treatment in China.

  2. Lands pollution; Pollution des sols

    Energy Technology Data Exchange (ETDEWEB)

    Hillewaere, J.P. [Direction regionale de l`industrie, de la recherche et de l`environnement, (DRIRE), Pas-de-Calais, 62 (France); Sauvalle, B. [Ministere de l`Amenagement du Territoire et de l`Environnement, 75 - Paris (France). Direction de la Prevention des Pollutions et des Risques; Llauro, D. [Rhone-Poulenc Industrialisation (France)] [and others

    1998-12-31

    This book reviews point by point all the pollution risks in terms of polluted land typology, regulations...It indicates too the methods to carry out for a simplified assessment, the treatment possibilities by bio-technologies, the eco-toxicity tests in the risk analysis. (O.M.)

  3. 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.

  4. Temporal Decrease in Upper Atmospheric Chlorine

    Science.gov (United States)

    Froidevaux, L.; Livesey, N. J.; Read, W. G.; Salawitch, R. J.; Waters, J. W.; Drouin, B.; MacKenzie, I. A.; Pumphrey, H. C.; Bernath, P.; Boone, C.; hide

    2006-01-01

    We report a steady decrease in the upper stratospheric and lower mesospheric abundances of hydrogen chloride (HCl) from August 2004 through January 2006, as measured by the Microwave Limb Sounder (MLS) aboard the Aura satellite. For 60(deg)S to 60(deg)N zonal means, the average yearly change in the 0.7 to 0.1 hPa (approx.50 to 65 km) region is -27 +/- 3 pptv/year, or -0.78 +/- 0.08 percent/year. This is consistent with surface abundance decrease rates (about 6 to 7 years earlier) in chlorine source gases. The MLS data confirm that international agreements to reduce global emissions of ozone-depleting industrial gases are leading to global decreases in the total gaseous chlorine burden. Tracking stratospheric HCl variations on a seasonal basis is now possible with MLS data. Inferred stratospheric total chlorine (CITOT) has a value of 3.60 ppbv at the beginning of 2006, with a (2-sigma) accuracy estimate of 7%; the stratospheric chlorine loading has decreased by about 43 pptv in the 18-month period studied here. We discuss the MLS HCl measurements in the context of other satellite-based HCl data, as well as expectations from surface chlorine data. A mean age of air of approx. 5.5 years and an age spectrum width of 2 years or less provide a fairly good fit to the ensemble of measurements.

  5. 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.

  6. Anaerobic microbial degradation of organic pollutants with chlorate as electron acceptor

    NARCIS (Netherlands)

    Mehboob, F.

    2010-01-01

    Aliphatic and aromatic hydrocarbons are two groups of compounds that are widespread pollutants. The aerobic microbial degradation of aliphatic and aromatic hydrocarbons proceeds in general fast and has been widely studied, while the biodegradation in anoxic environments is often incomplete, proceeds

  7. Surface Modification of Commercial Aromatic Polyamide Reverse Osmosis Membranes by Crosslinking Treatments

    Institute of Scientific and Technical Information of China (English)

    WEI Xinyu; WANG Zhi; XU Jun; WANG Jixiao; WANG Shichang

    2013-01-01

    Crosslinking treatments for a commercially available aromatic polyamide reverse osmosis membrane were carried out to improve its chlorine resistance.The crosslinking agents including 1,6-hexanediol diglycidyl ether,adipoyl dichloride and hexamethylene diisocyanate ester with long flexible aliphatic chains and high reactivity with N-H groups were used in the experiments.Attenuated total reflective Fourier transform infrared spectra verified the successful preparation of highly crosslinked membranes by crosslinking treatments.It was suggested that the crosslinking agents were connected to membrane surface through the reactions with amine and amide Ⅱ groups,which is confirmed by surface charge measurements.Based on contact angle measurements,crosslinking treatments decreased membrane hydrophilicity by introducing methylene groups to membrane surface.With increasing amount of crosslinking agent molecules connected to membrane surface,the hydrolysis of unconnected functional groups of crosslinking agent produced polar groups and increased membrane hydrophilicity.The highly crosslinked membranes showed higher salt rejections and lower water fluxes as compared with the raw membrane.Since the active sites (N-H groups) vulnerable to free chlorine on membrane surface were eliminated by crosslinking treatments,the chlorine resistances of the highly crosslinked membranes were significantly improved by slighter changes in both water fluxes and salt rejections after chlorination.

  8. 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.

  9. Emissions of Parent, Nitro, and Oxygenated Polycyclic Aromatic Hydrocarbons from Residential Wood Combustion in Rural China

    OpenAIRE

    SHEN, Guofeng; TAO, SHU; WEI, Siye; ZHANG, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; HUANG, YE; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wang, Xilong; Liu, Wenxin

    2012-01-01

    Residential wood combustion is one of the important sources of air pollution in developing countries. Among the pollutants emitted, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives, including nitrated and oxygenated PAHs (nPAHs and oPAHs), are of concern because of their mutagenic and carcinogenic effects. In order to evaluate their impacts on regional air quality and human health, emission inventories, based on realistic emission factors (EFs), are needed. In this study,...

  10. Changes in the contents of selected polycyclic aromatic hydrocarbons in soils of various types

    OpenAIRE

    Banach-Szott, Magdalena; Debska, Bozena; Wisniewska, Alicja; Pakula, Jaroslaw

    2015-01-01

    The aim of the paper was to determine the stability and the decomposition intensity of selected polycyclic aromatic hydrocarbons (fluorene, anthracene, pyrene, and chrysene) in soils that are under agricultural use. Soil was sampled from the arable layer that is representative of the Kujawy and Pomorze Provinces, which are located in the northwestern part of Poland. The soil samples were polluted with selected PAHs at an amount corresponding to 10?mg PAHs/kg. PAH-polluted soil samples were in...

  11. [Distribution of various polycyclic aromatic hydrocarbons in reservoir water of Estonia].

    Science.gov (United States)

    Veldre, I A; Itra, A R; Paal'me, L P; Urbas, E R

    1985-01-01

    The paper presents experimental data on different polycyclic aromatic hydrocarbons (PAH) in water, bottom sediments and algae as well as evidence available in literature on their content in exhausts of automobiles, oil shale industry and power station. Attempts are made to reveal differences in sources of the environment pollution with allowance for different PAH/benzo(a)pyrene percentage ratio, but as the PAH ratios are relatively similar in different pollution sources this attempt was a failure.

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

    OpenAIRE

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

    2007-01-01

    Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which had characteristic compositions and levels of PAH compo...

  13. A potential source of organic pollutants into the northeastern Atlantic: the outflow of the Mediterranean deep-lying waters through the Gibraltar Strait.

    Science.gov (United States)

    Martí, S; Bayona, J M; Albaigés, J

    2001-07-01

    Small and large-size particles were collected in the water column (50-3000 m) of a Northeastern Atlantic area where deep Mediterranean waters, outflowing through the Strait of Gibraltar, are incorporated at mid-depth. Particles collected by water filtration (0.7 micron pore size) and by vertical hauls of a neuston net (50 microns mesh size) were analyzed for organic pollutants, namely aliphatic and aromatic hydrocarbons, and organochlorine compounds. Small-size particles represented the largest bulk of particulate organic carbon as well as of hydrophobic organic pollutants. Surface concentrations of n-alkanes [C14-C35), aromatic hydrocarbons (12 parent compounds), PCBs (7 congeners), and DDTs (DDT + DDE) were, respectively, in the range of 50-63 ng/L, 23-68 pg/L, 8-13 pg/L, and 0.05-1.7 pg/L. These concentrations showed a general decrease with depth, particularly significant in the upper 200 m, consistently with the POC contents. Compositional changes with depth were also evident in small-size particles and included the depletion of low molecular weight n-alkanes and low chlorinated PCB congeners as well as a decrease of the fossil to pyrolytic PAHs ratio. Unusual increases of concentrations were observed at mid-depths (900-1100 m), indicating additional particle inputs, either by in-situ formation or by advective transport from the Mediterranean. The latter was recognized because small-size particles within these water veins exhibited distribution patterns out of the vertical sequence and similar to those of deep Mediterranean waters. An input of 8 and 0.5 tons per year of the above PAH and PCB compounds, respectively, has tentatively been calculated as the contribution of these Mediterranean waters to the Northeastern Atlantic.

  14. Predicting toxicity of aromatic ternary mixtures to algae

    Institute of Scientific and Technical Information of China (English)

    LU GuangHua; WANG Chao; WANG PeiFang; YANG ChengZhi

    2009-01-01

    Aquatic ecosystems are often polluted with more than one type of contaminant, and information on the combined toxic effects of mixed pollutants on aquatic organisms is scarce at present. Acute toxicity of aromatic compounds and their ternary mixtures to the alga (Scenedesmus obliquus) was determined by the algae growth inhibition test. The median effective concentration (EC_(50)) value for a single aromatic compound and EC_(50mix) values for mixtures were obtained, the logarithm of n-octanol/water partition coefficient (logP_(mix)) and the frontier orbital energy gap (△E_(mix) for mixtures were calculated. Based on the quantitative structure-activity relationship model for single chemical toxicity log(1/EC_(50)) =0.426logP-1.150△E+12.61 (n=15, R~2=0.917 and Q~2=0.878), the following two-descriptor model was developed for the ternary mixture toxicity of aromatic compounds: log(1/EC_(50mix))=O.68210gP_(mix)-O.367△E_(mix)+ 4.971 (n=44, R~2-0.869 and Q~2=0.843). This model can be used to predict the combined toxicity of mixtures containing toxicants with different mechanisms of action.

  15. Microbial degradation of petrochemical waste-polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Fulekar, M H

    2017-01-01

    Petrochemical industry is one of the fastest growing industries. This industry has immense importance in the growth of economy and manufacture of large varieties of chemicals. The petrochemical industry is a hazardous group of industry generating hazardous waste containing organic and inorganic compounds. In spite of the present treatment process, the hazardous waste compounds are found untreated to the acceptable level and found discharged at soil-water environment resulting into the persistent organic-inorganic pollutant into the environment. The bioremediation will be the innovative techniques to remove the persistent pollutants in the environment. Petrochemical contaminated site was found to be a rich source of microbial consortium degrading polycyclic aromatic hydrocarbons. Indigenous microbial consortiums were identified and used for bioremediation of polycyclic aromatic hydrocarbons (naphthalene and anthracene) at the concentrations of 250, 500, and 750 ppm. The potential microorganism was also identified for naphthalene and anthracene, and their bioremediation was studied at varying concentrations. The bioremediation with consortium was found to be comparatively more effective than the potential microorganism used for bioremediation of each compound. Pseudomonas aeruginosa a potential organism was identified by 16S rRNA and further studied for the gene responsible for the PAH compounds. Indigenous microorganism as a consortium has been found effective and efficient source for remediation of organic compound-Polycyclic aromatic hydrocarbon and this will also be applicable to remediate the toxic compounds to clean up the environment.

  16. Effects of gasoline aromatic content on emissions of volatile organic compounds and aldehydes from a four-stroke motorcycle.

    Science.gov (United States)

    Yao, Yung-Chen; Tsai, Jiun-Horng

    2013-01-01

    A new four-stroke carburettor motorcycle engine without any engine adjustments was used to study the impact of fuel aromatic content on the exhaust emissions of organic air pollutants (volatile organic compounds and carbonyls). Three levels of aromatic content, i.e. 15, 25, and 50% (vol.) aromatics mixed with gasoline were tested. The emissions of aromatic fuel were compared with those of commercial unleaded gasoline. The results indicated that the A 15 (15 vol% aromatics in gasoline) fuel exhibited the greatest total organic emission improvement among these three aromatic fuels as compared with commercial gasoline, reaching 59%. The highest emission factors of alkanes, alkenes, and carbonyl groups appeared in the reference fuel (RF) among all of the test fuels. A 15 showed the highest emission reduction in alkanes (73%), aromatics (36%), and carbonyls (28%), as compared to those of the RF. The highest emission reduction ofalkenes was observed when using A25 as fuel. A reduction in fuel aromatic content from 50 to 25 and 15 vol% in gasoline decreased benzene and toluene emissions, but increased the aldehyde emissions. In general, the results showed that the highest emission reductions for the most of measured organic pollutants appeared when using A 15 as the fuel.

  17. Evidence of Reactive Aromatics As a Major Source of Peroxy Acetyl Nitrate over China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhen; Wang, Yuhang; Gu, Dasa; Zhao, Chun; Huey, L. G.; Stickel, Robert; Liao, Jin; Shao, Min; Zhu, T.; Zeng, Limin; Liu, Shaw C.; Chang, Chih-Chung; Amoroso, Antonio; Costabile, Francesa

    2010-09-15

    We analyze the observations of near-surface peroxy acetyl nitrate (PAN) and its precursors in Beijing, China in August of 2007. The levels of PAN are remarkably high (up to 14 ppbv), surpassing those measured over other urban regions in recent years. Analyses employing a 1-D version of a chemical transport model (Regional chEmical and trAnsport Model, REAM) indicate that aromatic non-methane hydrocarbons (NMHCs) are the dominant (55-75%) PAN source. The major oxidation product of aromatics that produces acetyl peroxy radicals is methylglyoxal (MGLY). PAN and O3 in the observations are correlated at daytime; aromatic NMHCs appear to play an important role in O3 photochemistry. Previous NMHC measurements indicate the presence of reactive aromatics at high levels over broad polluted regions of China. Aromatics are often ignored in global and (to a lesser degree) regional 3D photochemical transport models; their emissions over China as well as photochemistry are quite uncertain.Our findings suggest that critical assessments of aromatics emissions and chemistry (such as the yields of MGLY) are necessary to understand and assess ozone photochemistry and regional pollution export in China.

  18. The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, W.E. Jr. [Alabama Power Co./GSC No. 8, Birmingham, AL (United States); Laylor, M.M. [Univ. of Alabama, Birmingham, AL (United States)

    1995-06-01

    Continuous chlorination has been successfully used for the control of Corbicula at a nuclear power plant located on the Chattahoochee River in southeastern Alabama, since 1986. The purpose of this study was to investigate further minimization of chlorine usage and determine if chlorine dioxide is a feasible alternative. Four continuous biocide treatments were evaluated for macro and microfouling control effectiveness, operational feasibility, and environmental acceptability. One semi-continuous chlorination treatment was also evaluated for macrofouling control effectiveness. Higher treatment residuals were possible with chlorine dioxide than with chlorination due to the river discharge limitations. At the levels tested, continuous chlorine dioxide was significantly more effective in providing both macro and microfouling control. Semi-continuous chlorination was just as effective as continuous chlorination for controlling macrofouling. The Corbicula treatment programs that were tested should all provide sufficient control for zebra mussels. Chlorine dioxide was not as cost effective as chlorination for providing macrofouling control. The semi-continuous treatment save 50% on chemical usage and will allow for the simultaneous treatment of two service water systems. Chlorite levels produced during the chlorine dioxide treatments were found to be environmentally acceptable. Levels of trihalomethanes in the chlorinated service water were less than the maximum levels allowed in drinking water.

  19. 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...

  20. Occupational exposure to chlorinated and petroleum solvents and mycosis fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M; Olsen, Jørn; 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)....

  1. 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

  2. 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

  3. 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 chlorinated aro

  4. Air Pollution

    Science.gov (United States)

    ... to view this content or go to source URL . What NIEHS is Doing on Air Pollution Who ... Junction Last Reviewed: February 06, 2017 This page URL: NIEHS website: https://www.niehs.nih.gov/ Email ...

  5. Water Pollution

    Science.gov (United States)

    ... Home Page Brochures & Fact Sheets Environmental Health Topics Science Education Kids Environment | Kids Health Research Home Page At NIEHS ... Agents Water Pollution Environmental Science Basics Population Research Science Education Kids Environment | Kids Health Research Home Research At NIEHS ...

  6. 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.

  7. Diurnal variation of stratospheric chlorine monoxide - A critical test of chlorine chemistry in the ozone layer

    Science.gov (United States)

    Solomon, P. M.; De Zafra, R.; Parrish, A.; Barrett, J. W.

    1984-01-01

    Ground-based observations of a mm-wave spectral line at 278 GHz have yielded stratospheric chlorine monoxide column density diurnal variation records which indicate that the mixing ratio and column density of this compound above 30 km are about 20 percent lower than model predictions based on 2.1 parts/billion of total stratospheric chlorine. The observed day-to-night variation is, however, in good agreement with recent model predictions, both confirming the existence of a nighttime reservoir for chlorine and verifying the predicted general rate of its storage and retrieval.

  8. 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.

  9. 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.

  10. DISTRIBUTION AND CHARACTERIZATION OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN AIRBORNE PARTICULATES OF EAST ASIA

    Institute of Scientific and Technical Information of China (English)

    Yan Liu; Libin Liu; Jin-Ming Lin; Ning Tang; Kazuichi Hayakawa

    2006-01-01

    A review is presented on the distribution and characterization of polycyclic aromatic hydrocarbons (PAHs)and their derivatives, including nitro-PAHs and hydro-PAHs, on atmospheric particulates of East Asia. Generally, PAH compounds with two or three aromatic rings are released mainly into the gas phase, while those containing three or more aromatic rings are associated with particulate matter (PM) emission. Particle-associated PAHs are primarily adsorbed on fine particles, and little associated with coarse particles. Investigation into the concentration level of PAHs in different areas can serve not only to reflect the pollutant status and sources but also to lead to the formulation of control strategies.The results of the present study show that China has more severe PAH pollution than such East Asian countries as Japan and Korea.

  11. Potent reversible inhibition of myeloperoxidase by aromatic hydroxamates.

    Science.gov (United States)

    Forbes, Louisa V; Sjögren, Tove; Auchère, Françoise; Jenkins, David W; Thong, Bob; Laughton, David; Hemsley, Paul; Pairaudeau, Garry; Turner, Rufus; Eriksson, Håkan; Unitt, John F; Kettle, Anthony J

    2013-12-20

    The neutrophil enzyme myeloperoxidase (MPO) promotes oxidative stress in numerous inflammatory pathologies by producing hypohalous acids. Its inadvertent activity is a prime target for pharmacological control. Previously, salicylhydroxamic acid was reported to be a weak reversible inhibitor of MPO. We aimed to identify related hydroxamates that are good inhibitors of the enzyme. We report on three hydroxamates as the first potent reversible inhibitors of MPO. The chlorination activity of purified MPO was inhibited by 50% by a 5 nm concentration of a trifluoromethyl-substituted aromatic hydroxamate, HX1. The hydroxamates were specific for MPO in neutrophils and more potent toward MPO compared with a broad range of redox enzymes and alternative targets. Surface plasmon resonance measurements showed that the strength of binding of hydroxamates to MPO correlated with the degree of enzyme inhibition. The crystal structure of MPO-HX1 revealed that the inhibitor was bound within the active site cavity above the heme and blocked the substrate channel. HX1 was a mixed-type inhibitor of the halogenation activity of MPO with respect to both hydrogen peroxide and halide. Spectral analyses demonstrated that hydroxamates can act variably as substrates for MPO and convert the enzyme to a nitrosyl ferrous intermediate. This property was unrelated to their ability to inhibit MPO. We propose that aromatic hydroxamates bind tightly to the active site of MPO and prevent it from producing hypohalous acids. This mode of reversible inhibition has potential for blocking the activity of MPO and limiting oxidative stress during inflammation.

  12. [Formation of disinfection by-products by Microcystis aeruginosa intracellular organic matter: comparison between chlorination and bromination].

    Science.gov (United States)

    Tian, Chuan; Guo, Ting-Ting; Liu, Rui-Ping; Jefferson, William; Liu, Hui-Juan; Qu, Jiu-Hui

    2013-11-01

    In order to illustrate the effects of released algal organic matter in cyanobacteria blooms on raw water quality and water treatment process, intracellular organic matter (IOM) of Microcystis aeruginosa, which is the dominant species in cyanobacteria blooms, was chosen as a precursor and characterized. In addition, the transformation of IOM and the formation of disinfection byproducts were evaluated at different pH of 6.5, 7.1 and 8.4 after chlorination or bromination, with subsequent correlation analysis. The results indicated that IOM was primarily composed of macromolecular matter, i. e. , the species with relative molecular weight of > 30 x 10(3), constituting 68.8% of dissolved organic carbon (DOC). Fluorescence excitation-emission matrix indicated that IOM was mainly composed of aromatic protein-like matter with an intensity of 92.6 AU x L x mg(-1). After reaction with chlorine or bromine, the intensity of aromatic protein-like peaks decreased sharply by 76.6% - 93.3%, and its reduction correlated well with the formation of trihalomethane (THMs, R2 = 0.81) and haloacetic acid (HAAs, R2 = 0.77). The formation of THMs and HAAs increased with the increase in pH. Compared with chlorine, bromine formed more THMs and HAAs, and tended to form highly halogenated HAAs. However, with increasing pH, the reactivity with IOM between chlorine and bromine was closer, i.e, k(OBr-IOM)/k(OCl-(IOM) < k(HOBr-IOM/k(HOCl-IOM).

  13. 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

  14. Effect of three polycyclic aromatic hydrocarbons on nodulation of Rhizobium tropici CIAT 899 on Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Paredes, Y.; Ferrera-Cerrato, R.; Alarcon, A.

    2009-07-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous organic pollutants that are considered toxic and carcinogenic compounds to living organisms. There us scarce information about the effect of PAH on symbiotic systems such as Azolla-Anabaena, arbuscular mycorrhizal fungi-plants, or legume-rhizobia. (Author)

  15. Isolation and screening of black fungi as degraders of volatile aromatic hydrocarbons

    NARCIS (Netherlands)

    Isola, D.; Selbmann, L.; de Hoog, G.S.; Fenice, M.; Onofri, S.; Prenafeta-Boldu, F.X.; Zucconi, L.

    2013-01-01

    Black fungi reported as degraders of volatile aromatic compounds were isolated from hydrocarbon-polluted sites and indoor environments. Several of the species encountered are known opportunistic pathogens or are closely related to pathogenic species causing severe mycoses, among which are

  16. POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL

    Science.gov (United States)

    Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

  17. [Effects of soil PAHs pollution on plant ecophysiology].

    Science.gov (United States)

    Xu, Sheng; Wang, Hui; Chen, Wei; He, Xing-Yuan; Su, Dao-Yan; Li, Bo; Li, Mei

    2013-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are the ubiquitous organic persistent pollutants in natural environments (especially in soil), giving serious potential risks to the eco-environment, plants, and human beings. At present, the remediation of PAHs-polluted soil is one of the hot topics in the research fields of soil and environment. Phytoremediation is one of the environmental restoration techniques with most potentiality. This paper reviewed the newest progress in the researches of the effects of soil PAHs pollution and its combined stress with other pollutants on the plant growth, morphological structure, photosynthesis, and antioxidant system, and prospected the important fields and hotspots of related researches in the future.

  18. ROLE OF ENTRAINERS IN SUPERCRITICAL FLUID EXTRACTION OF CHLORINATED AROMATICS FROM SOILS. (R825549C011)

    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...

  19. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  20. Distribution, possible sources, and health risk assessment of SVOC pollution in small streams in Pearl River Delta, China.

    Science.gov (United States)

    Sun, Hongwei; An, Taicheng; Li, Guiying; Qiao, Meng; Wei, Dongbin

    2014-09-01

    The pollution levels of typical semivolatile organic compounds (SVOCs) consisting of 15 polycyclic aromatic hydrocarbons (PAHs), 20 organic chlorinated pesticides (OCPs), and 15 phthalate esters (PAEs) were investigated in small rivers running through the flourishing cities in Pearl River Delta region, China. The concentrations of ∑15PAHs were 2.0-48 ng/L and 29-1.2 × 10(3) ng/g in the water and sediment samples, respectively. The ∑20OCPs were 6.6-57 ng/L and 9.3-6.0 × 10(2) ng/g in the water and sediment samples, respectively. The concentrations of ∑15PAEs were much higher both in the water and sediments. The partition process of the detected SVOCs between the water and sediment did not reach the equilibrium state at most of the sites when sampling. The combustion of petroleum products and coal was the major source of the detected PAHs. The OCPs were mainly historical residue, whereas the new inputs of dichlorodiphenyltrichloroethane (DDT), chlordane, and endosulfan were possible at several sites. The industrial and domestic sewage were the major source for the PAEs; storm water runoff accelerated the input of PAEs. No chronic risk of the SVOCs was identified by a health risk assessment through daily water consumption, except for the ∑20OCPs that might cause cancer at several sites. Nevertheless, the integrated health risk of the SVOCs should not be neglected and need intensive investigations.

  1. A study of chlorinated solvent contamination of the aquifers of an industrial area in central Italy: a possibility of bioremediation

    OpenAIRE

    FEDERICA eMATTEUCCI; CLAUDIA eERCOLE; MADDALENA eDEL GALLO

    2015-01-01

    Perchloroethene, Trichloroethene, and other chlorinated solvents are widespread groundwater pollutants. They form Dense Non Aqueous Phase Liquids (DNAPLs) that sink through permeable groundwater aquifers until non-permeable zone is reached. In Italy there are many situations of serious contamination of groundwater that might compromise their use in industry, agriculture, private, as the critical case of a Central Italy valley located in the province of Teramo (Val Vibrata), characterized by a...

  2. Chlorination of nickel ore by gaseous chlorine in the presence of active additives

    Directory of Open Access Journals (Sweden)

    Ilić Ilija B.

    2003-01-01

    Full Text Available Paper presents a thermodynamic analysis of chemical reactions occurring during chlorination with and without additives for both nickel oxides and nickel ferrites, which are component parts of nickel ore. The experimental research investigated the influence of temperature in the range from 600 up to 1000 °C and time (up to 3 h on the chlorination degree of nickel ores with and without additives. It was found that the introduction of additives such as C, S, BaS and NaCl intensified the chlorination of nickel ore. The results can be applied and may help determine the optimal conditions for the chlorination of low-grade ferrous nickel ores.

  3. Synthesis of functional aromatic multisulfonyl chlorides and their masked precursors.

    Science.gov (United States)

    Percec, V; Bera, T K; De, B B; Sanai, Y; Smith, J; Holerca, M N; Barboiu, B; Grubbs, R B; Fréchet, J M

    2001-03-23

    The synthesis of functional aromatic bis(sulfonyl chlorides) containing an acetophenone and two sulfonyl chloride groups, i.e., 3,5-bis[4-(chlorosulfonyl)phenyl]-1-acetophenone (16), 3,5-bis(chlorosulfonyl)-1-acetophenone (17), and 3,5-bis(4-(chlorosulfonyl)phenyloxy)-1-acetophenone (18) via a sequence of reactions, involving in the last step the quantitative oxidative chlorination of S-(aryl)- N,N'-diethylthiocarbamate, alkyl- or benzyl thiophenyl groups as masked nonreactive precursors to sulfonyl chlorides is described. A related sequence of reactions was used for the synthesis of the aromatic trisulfonyl chloride 1,1,1-tris(4-chlorosulfonylphenyl)ethane (24). 4-(Chlorosulfonyl)phenoxyacetic acid, 2,2-bis[[[4-(chlorosulfonyl)phenoxyacetyl]oxy]methyl]-1,3-propanediyl ester (27), 5,11,17,23-tetrakis(chlorosulfonyl)-25,26,27,28-tetrakis(ethoxycarbonylmethoxy)calix[4]arene (38), 5,11,17,23,29,35-hexakis(chlorosulfonyl)-37,38,39,40,41,42-hexakis(ethoxycarbonylmethoxy)calix[6]arene (39), 5,11,17,23,29,35,41,47-octakis(chlorosulfonyl)-49,50,51,52,53,54,55,56-octakis(ethoxycarbonylmethoxy)calix[8]arene (40), 5,11,17,23-tetrakis(tert-butyl)-25,26,27,28-tetrakis(chlorosulfonyl phenoxyacetoxy)calix[4]arene (44), 5,11,17,23,29,35-hexakis(tert-butyl)-37,38,39,40,41,42-hexakis(chlorosulfonylphenoxyacetoxy)calix[6]arene (45), and 5,11,17,23,29,35,41,47-octakis(tert-butyl)-49,40,51,52,53,54,55,56-octakis(chlorosulfonylphenoxyacetoxy)calix[8]arene (46) were synthesized by two different multistep reaction procedures, the last step of both methods consisting of the chlorosulfonation of compounds containing suitable activated aromatic positions. 2,4,6-Tris(chlorosulfonyl)aniline (47) was obtained by the chlorosulfonation of aniline. The conformation of two series of multisulfonyl chlorides i.e., 38, 39, 40 and 44, 45, 46, was investigated by (1)H NMR spectroscopy. The masked nonreactive precursor states of the functional aromatic multisulfonyl chlorides and the aromatic

  4. Monitoring of pollution in Egyptian Red Sea

    Directory of Open Access Journals (Sweden)

    Renee I. Abdallah

    2015-03-01

    Full Text Available The level of the Egyptian Red Sea water pollution by oil was studied to assess the general pattern of oil pollutants and to evaluate the hydrocarbon origin (anthropogenic, petrogenic or biogenic with emphasis on the poly aromatic hydrocarbons in surface water. The oil extracted from the samples was analyzed by gas chromatography to determine the concentrations and distribution of aliphatic and alicyclic n-alkanes. Results obtained indicate that most of the organic species present in water samples consist of petrogenic hydrocarbons with additional biogenic types. High performance liquid chromatography (HPLC technique was used to study the poly aromatic hydrocarbons (PAHs fingerprints of the studied water samples. The results obtained indicate the presence of PAHs of both pyrogenic and petrogenic origins.

  5. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-05-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the

  6. Risk assessment of metals and organic pollutants for herbivorous and carnivorous small mammal food chains in a polluted floodplain (Biesbosch, The Netherlands)

    NARCIS (Netherlands)

    Hamers, T.H.M.; Berg, van den J.H.J.; Gestel, van C.A.M.; Schooten, van F.J.; Murk, A.J.

    2006-01-01

    A risk assessment was made for a carnivorous and a herbivorous food chain in a heavily polluted natural estuary (Biesbosch), by determining the most critical pollutants and the food chain most at risk. Exposure of food chains to metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated

  7. Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, Appavu; Deepa, Mohan [Molecular Biophysics Unit, Indian Institute of Sciences-Bangalore, Karnataka (India); Govindaraju, Munisamy [Bio-Spatial Technology Research Unit, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India)

    2016-02-26

    While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”.

  8. Cellular Response of the Amoeba Acanthamoeba castellanii to Chlorine, Chlorine Dioxide, and Monochloramine Treatments ▿

    OpenAIRE

    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 o...

  9. Urban pollution.

    Science.gov (United States)

    Sancini, Angela; Tomei, Francesco; Tomei, Gianfranco; Caciari, Tiziana; Di Giorgio, Valeria; André, Jean-Claude; Palermo, Paola; Andreozzi, Giorgia; Nardone, Nadia; Schifano, Maria Pia; Fiaschetti, Maria; Cetica, Carlotta; Ciarrocca, Manuela

    2012-01-01

    Air pollution represents a health risk for people living in urban environment. Urban air consists in a complex mixture of chemicals and carcinogens and its effects on health can be summarized in acute respiratory effects, neoplastic nonneoplastic (e.g. chronic bronchitis) chronic respiratory effects, and effects on other organs and systems. Air pollution may be defined according to origin of the phenomena that determine it: natural causes (natural fumes, decomposition, volcanic ash) or anthropogenic causes which are the result of human activities (industrial and civil emissions). Transport is the sector that more than others contributes to the deterioration of air quality in cities. In this context, in recent years, governments of the territory were asked to advance policies aimed at solving problems related to pollution. In consideration of the many effects on health caused by pollution it becomes necessary to know the risks from exposure to various environmental pollutants and to limit and control their effects. Many are the categories of "outdoor" workers, who daily serve the in urban environment: police, drivers, newsagents, etc.

  10. FISH CANCER DEVELOPED BY ENVIRONMENTAL POLLUTANTS

    Directory of Open Access Journals (Sweden)

    Madhuri S.

    2012-10-01

    Full Text Available The pollution of rivers and streams with chemical contaminants has become one of the most critical environmental problems. Fish living in a polluted water reservoir use the contaminated water to rinse their gills; this results in the deposition of polycyclic aromatic hydrocarbons (PAHs in the fish body. Contamination of foodstuffs by heavy metals such as arsenic, cadmium, chromium, nickel and lead has poses a potential carcinogenic threat to humans. Arsenic and cadmium appear to be the most harmful to the fish. Several cancers in fish appear to be the result of exposure to different environmental pollutants/chemicals. High frequencies of liver and skin cancers in brown bullheads are associated with high concentrations of PAHs and some metals in the environmental sediments. Taking these facts in view, the present article gives the emphasis on the fish cancer caused by various environmental pollutants, suggesting that fish species are truly suffer from different cancers/tumours.

  11. Method and apparatus for producing chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Santillie, P.W.; Ramras, D.M.

    1984-05-29

    A continuous method and apparatus are described for the efficient production of gaseous chlorine dioxide by the reaction between gaseous sulfur dioxide and an aqueous solution of a metallic chlorate. The chlorate solution and a highly concentrated sulfur dioxide gas are introduced into a packed columnar chamber at closely adjacent locations at the bottom of the chamber so as to flood the chamber and maximize both the contact area and contact time of the two reactants. Throughout the reaction the chamber is subjected to high vacuum imposed by an eductor which exhausts the chlorine dioxide gas and spent reactants. For use of the chlorine dioxide to produce potable water or treat foodstuffs, the chlorine dioxide and spent reactants are exhausted from the chamber separately by respective eductors substantially balanced with respect to each other to impose comparable vacuums upon the chamber. Because of the high efficency of the reaction, substantial heat is generated therefrom which is absorbed by a coolant flowing through a jacket surrounding the chamber. The flow rate of the coolant and flow rate of the reactants into the chamber are porportional due to the dependency of the reactant flow rate on the coolant flow rate.

  12. Photoabsorption and photoionization of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Flesch, R.; Ruehl, E.; Hottmann, K.; Baumgaertel, H. (Freie Universitaet Berlin (Germany))

    1993-01-28

    Photoprocesses of chlorine dioxide in the near-UV have become highly important for stratospheric photoprocesses at high latitudes, especially in Antarctica. Chlorine dioxide has been identified among other absorbers because of its specific absorption cross section in the near-UV. Possible contributions of chlorine dioxide photochemistry to polar ozone depletion have been discussed recently. The high-resolution He I photoelectron spectrum and the absolute (vacuum-UV) absorption cross section (6-25 eV) as well as the ionic fragmentation of chlorine dioxide (OCIO) are reported. The photoelectron spectrum is interpreted in terms of exchange splitting effects of the various singlet and triplet cation states as well as by comparison to chemically related molecules. The vacuum-UV absorption spectrum shows different Rydberg series converging to the cation states. These Rydberg series and their vibrational progressions are assigned by term value arguments, dipole selection rules, and comparison with the photoelectron spectrum. Photoionization mass spectrometry is used for measurements of the ionization and fragmentation threshold of OCIO. The major fragment is ClO[sup +] which occurs above 13.4 eV. Thermomechanical data such as heats of formation and bond dissociation energies are derived. No evidence for isomerization of OClO[sup +] is found, as observed for the electronically excited neutral molecule. 54 refs., 6 figs., 7 tabs.

  13. Inhibitor treatment program for chlorine dioxide corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Edmondson, J.G.; Holder, E.P.

    1991-11-12

    This patent describes a method of inhibiting corrosion by chlorine dioxide in oil field waterflood systems by adding a sufficient amount of a corrosion inhibiting composition. It comprises a phosphonate, a copolymer consisting of repeating units of acrylic acid/allyl hydroxy propyl sulfonate ether, and a permangante.

  14. 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.

  15. Modelling Of Chlorine Inductive Discharges

    Science.gov (United States)

    Chabert P.; Despiau-Pujo, E.

    2010-07-01

    .02, which is much lower than the value predicted for stainless steel walls (? = 0.6). This is consistent with reactor wall contaminations classi- cally observed in such discharges. The plasma electronegativity decreases with RF power and increases with Cl2 content. At high pressure, the power absorption and distribution of charged particles become more localized below the quartz window. Although the experi- mental trends are well reproduced by the model, the calculated charged particle densities are systematically overestimated by a factor of 3-5. The reasons for this discrepancy are discussed in the paper. Experimental studies have also shown that low-pressure inductive discharges operating with electronegative gases are subject to instabilities near the transition between capacitive (E) and inductive (H) modes. A global model, consisting of two particle balance equations and one energy balance equation, has been previously proposed to describe the instability mechanism in SF6/ArSF6 (Lieberman et al. 1999). This model, which agrees qualitatively well with experimental observations, leaves significant quantitative differences. In this work, this global model is revisited with Cl2 as the feedstock gas (Despiau-Pujo and Chabert 2009). An alternative treatment of the inductive power deposition is evaluated and chlorine chemistry is included. Old and new models are systematically compared. The alternative inductive coupling description slightly modifies the results. The effect of gas chemistry is even more pronounced. The instability window is smaller in pressure and larger in absorbed power, the frequency is higher and the amplitudes of oscillations are reduced. The feedstock gas is weakly dissociated (~16%) and Cl2+ is the dominant positive ion, which is consistent with the moderate electron density during the instability cycle.

  16. Removal of endocrine disruptors and non-steroidal anti-inflammatory drugs through wastewater chlorination: the effect of pH, total suspended solids and humic acids and identification of degradation by-products.

    Science.gov (United States)

    Noutsopoulos, Constantinos; Koumaki, Elena; Mamais, Daniel; Nika, Maria-Christina; Bletsou, Anna A; Thomaidis, Nikolaos S

    2015-01-01

    Endocrine disrupting chemicals (EDCs) and non-steroidal anti-inflammatory drugs (NSAIDs) are two groups of emerging pollutants the significance of which rests on their persistent detection in the aquatic environment and their possible adverse effects. Wastewater treatment plants are one of the major ways for transporting such chemicals in the aquatic environment. Chlorination is usually the last stage of treatment before wastewater being disposed to the aquatic environment. This work focuses on the evaluation of the effect of chlorine dose and specific wastewater characteristics (pH, total suspended solids and humic acids) on the removal of target EDCs and NSAIDs through chlorination. Another objective of this study is the identification of chlorination by-products of specific EDCs and NSAIDs and their dependence on contact time. Based on the results it is concluded that the effect of chlorine dose and humic acids concentration on the degradation of target compounds during chlorination is minimal. On the contrary, pH is a critical parameter which highly affects process performance. Moreover, it is concluded that not only the free available chlorine species, but also the properties of EDCs and NSAIDs under different pH conditions can affect chlorination process performance. The effect of TSS on the degradation of the target compounds during chlorination is more profound for chemicals with high Kow values and therefore higher affinity to partition to the particulate phase (i.e. nonylphenols, triclosan). Several degradation by-products were identified through chlorination of nonylphenol, bisphenol A and diclofenac. The dependence of these by-products on chlorination contact time is also demonstrated. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Kinetic models and pathways of ronidazole degradation by chlorination, UV irradiation and UV/chlorine processes.

    Science.gov (United States)

    Qin, Lang; Lin, Yi-Li; Xu, Bin; Hu, Chen-Yan; Tian, Fu-Xiang; Zhang, Tian-Yang; Zhu, Wen-Qian; Huang, He; Gao, Nai-Yun

    2014-11-15

    Degradation kinetics and pathways of ronidazole (RNZ) by chlorination (Cl2), UV irradiation and combined UV/chlorine processes were investigated in this paper. The degradation kinetics of RNZ chlorination followed a second-order behavior with the rate constants calculated as (2.13 ± 0.15) × 10(2) M(-2) s(-1), (0.82 ± 0.52) × 10(-2) M(-1) s(-1) and (2.06 ± 0.09) × 10(-1) M(-1) s(-1) for the acid-catalyzed reaction, as well as the reactions of RNZ with HOCl and OCl(-), respectively. Although UV irradiation degraded RNZ more effectively than chlorination did, very low quantum yield of RNZ at 254 nm was obtained as 1.02 × 10(-3) mol E(-1). RNZ could be efficiently degraded and mineralized in the UV/chlorine process due to the generation of hydroxyl radicals. The second-order rate constant between RNZ and hydroxyl radical was determined as (2.92 ± 0.05) × 10(9) M(-1) s(-1). The degradation intermediates of RNZ during the three processes were identified with Ultra Performance Liquid Chromatography - Electrospray Ionization - mass spectrometry and the degradation pathways were then proposed. Moreover, the variation of chloropicrin (TCNM) and chloroform (CF) formation after the three processes were further evaluated. Enhanced formation of CF and TCNM precursors during UV/chlorine process deserves extensive attention in drinking water treatment.

  19. 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

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

    OpenAIRE

    Marijanović-Rajčić, M.; Senta, A.

    2008-01-01

    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 Sašna...

  1. Light Naphtha Aromatization(LNA) Process for Aromatics Production

    National Research Council Canada - National Science Library

    KATO, Koichi; FUKASE, Satoshi

    1994-01-01

    .... The coke deposit on the catalyst was found to be increased at higher pressure. The long-cycle-time stability of zinc-aluminosilicates resulted in the design of a new process of light naphtha aromatization using a conventional fixed bed unit...

  2. Aromaticity of group 14 organometallics: experimental aspects.

    Science.gov (United States)

    Lee, Vladimir Ya; Sekiguchi, Akira

    2007-01-01

    The long story of aromatic compounds has extended over almost two centuries, since the discovery by Faraday of "bicarburet of hydrogen", or C(6)H(6), now called benzene. Since then, the chemistry of aromatic compounds has been developed extensively; this is reflected in the synthesis of novel classes of aromatic derivatives including charged species, nonclassical (Möbius, three-dimensional, homo-, metalla-) aromatics, and fullerenes. The theory of aromaticity has also undergone a spectacular evolution since the first definition of aromaticity by Hückel; the classification of aromaticity now requires the consideration of versatile criteria: energetic, structural, magnetic, among others. In this Review, we discuss the current state of affairs in the chemistry of aromatic compounds of the heavier Group 14 elements, the latest experimental achievements, as well as future prospects in the field.

  3. Water Pollution

    Science.gov (United States)

    We all need clean water. People need it to grow crops and to operate factories, and for drinking and recreation. Fish and wildlife depend on ... and phosphorus make algae grow and can turn water green. Bacteria, often from sewage spills, can pollute ...

  4. SOURCE, FORMATION, POLLUTION AND ITSCOUNTERMEASURE OF DIOXIN IN PAPERMAKING INDUSTRY

    Institute of Scientific and Technical Information of China (English)

    HuiLi; YoumingLi; MingliFu; yanjinBi

    2004-01-01

    Dioxins are believed the most poisonous compounds in the world. Dioxin pollution is a strategic problem in papermaking industry which must be solved. Dioxin not only exists in pulp, paper products, but also in the volatile of woods, hips or other non-wood fiber material which are treated with PCP, even in the exhaust gas of chemical recovery system. So there are great needs to know what is dioxin, the channel and mechanism of the formation of it in papermaking industry. With these understanding, herein those are discussed as follows, the harness measure of dioxin: dioxin in wastewater, in exhaust gas, from raw material. And some countermeasure to decrease the content of dioxin. Furthermore, several novel treatment technologies ofdioxin in China and abroad were introduced. The fundamental measure to eliminate the pollution ofdioxin is presented with the aim to control the origin, decrease the use of bleachercontaining chlorine or without the use of chlorine. Elemental Chlorine Free and Total Chlorine Free bleaching are advocated.

  5. Oxidative elimination of cyanotoxins: comparison of ozone, chlorine, chlorine dioxide and permanganate.

    Science.gov (United States)

    Rodríguez, Eva; Onstad, Gretchen D; Kull, Tomas P J; Metcalf, James S; Acero, Juan L; von Gunten, Urs

    2007-08-01

    As the World Health Organization (WHO) progresses with provisional Drinking Water Guidelines of 1 microg/L for microcystin-LR and a proposed Guideline of 1 microg/L for cylindrospermopsin, efficient treatment strategies are needed to prevent cyanotoxins such as these from reaching consumers. A kinetic database has been compiled for the oxidative treatment of three cyanotoxins: microcystin-LR (MC-LR), cylindrospermopsin (CYN), and anatoxin-a (ANTX) with ozone, chlorine, chlorine dioxide and permanganate. This kinetic database contains rate constants not previously reported and determined in the present work (e.g. for permanganate oxidation of ANTX and chlorine dioxide oxidation of CYN and ANTX), together with previously published rate constants for the remaining oxidation processes. Second-order rate constants measured in pure aqueous solutions of these toxins could be used in a kinetic model to predict the toxin oxidation efficiency of ozone, chlorine, chlorine dioxide and permanganate when applied to natural waters. Oxidants were applied to water from a eutrophic Swiss lake (Lake Greifensee) in static-dose testing and dynamic time-resolved experiments to confirm predictions from the kinetic database, and to investigate the effects of a natural matrix on toxin oxidation and by-product formation. Overall, permanganate can effectively oxidize ANTX and MC-LR, while chlorine will oxidize CYN and MC-LR and ozone is capable of oxidizing all three toxins with the highest rate. The formation of trihalomethanes (THMs) in the treated water may be a restriction to the application of sufficiently high-chlorine doses.

  6. [Contamination characteristics of short-chain chlorinated paraffins in edible fish of Shanghai].

    Science.gov (United States)

    Jiang, Guo; Chen, Lai-guo; He, Qiu-sheng; Meng, Xiang-zhou; Feng, Yong-bin; Huang, Yu-mei; Tang, Cai-ming

    2013-09-01

    According to the local habit of eating fish, in a total of 68 samples, 8 kinds of different trophic levels of edible fish collected in Shanghai were determined in terms of concentration and distribution profile of short chain chlorinated paraffin (SCCPs) in muscles to investigate the pollution status of SCCPs in edible fish from the Yangtze River Delta region. The results indicated that the concentrations (dw) of SCCPs in edible fish were in the range of 36-801 ng x g(-1). With the increase in carbon chain length, the concentration of SCCPs decreased. In addition, lower chlorinated (Cl6-Cl8) and shorter chain (Cl10, C11) congeners were the dominant chlorine and carbon homologues groups, respectively, contributing a total relative abundance of 61.46%-82.50% to the total abundance of SCCPs. The levels of SCCPs in fish of Shanghai were in the medium level worldwide, and the distribution pattern was in line with those of the domestic and foreign studies.

  7. 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.

  8. Evaluation of the Most Current and Effective Methods in the Analysis of Chlorinated Dioxins in Ground Beef

    Directory of Open Access Journals (Sweden)

    Ebere C. Anyanwu

    2003-01-01

    Full Text Available Chlorinated dioxins are the group of environmental pollutants consisting of 210 chlorinated dibenzo-p-dioxins and dibenzofurans. They are highly toxic and persistent. They are lipophilic and can easily biomagnify in the food chain, hence posing a serious threat to human health. The daily consumption of low-level contaminated food, mainly of animal origin, leads to the accumulation of dioxins in the human body. The exposures of the general human population to dioxins and the specific issues of a risk assessment of dioxin pose serious concerns in public environmental and nutritional health. This paper reviews the analysis of chlorinated dioxins in ground beef. The sources of contamination of chlorinated dioxins in ground beef are first reviewed to form a basis for a clear understanding of the health implications of chlorinated dioxins in the human food chain and why it is necessary to monitor the level of dioxins in animal food products, especially ground beef. The methods of collection, sampling, and processing of ground beef, and the methods of sample clean up prior to the analysis, are reviewed. Emphasis is laid on the new techniques that are available and that might be effective in the analysis of chlorinated dioxins in ground beef. Among these new methods and techniques are: the synergistic combination of ELISA/GC/MS, direct sample introduction to /GC/MS-MS, automated clean-up method, and the supercritical fluid extraction methods. The possible treatments of results from each method and technique are discussed and their respective efficiencies are compared. Finally, quality control and quality assurance parameters are evaluated for levels of accuracy, reproducibility, and precision.

  9. Comparative efficacy of chlorine and chlorine dioxide regimes for condenser slime control in seawater cooled heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, P.S.; Veeramani, P.; Ershath, M.; Rajamohan, R.; Harinath, Y.V.; Mohan, T.V.K.; Venugopalan, V.P. [BARC Facilities, Water and Steam Chemistry Div., Kalpakkam, Tamil nadu (India)

    2010-07-01

    Chlorination has long been used as an effective and economic biocide for biofouling control in seawater cooling systems. However, the efficacy of chlorine is reduced in the presence of organic content of seawater and the inability of chlorine to effectively penetrate biofilms. Chlorine dioxide is being projected as a possible alternative to chlorine. Experiments were carried out with the help of a seawater circulating facility, in which direct comparison of the efficacy of the two biocides was possible using test condenser tube assemblies. The test condenser tubes made of titanium, SS 316L and Cu-Ni 90/10 were dosed with chlorine and chlorine dioxide. Each dose was evaluated for 30 days. Continuous and intermittent additions of chlorine (0.38 - 0.45 mg L{sup -1} TRO) and chlorine dioxide (0.4 - 0.5 mg L{sup -1}) were used, along with control. The flow velocity in the tubes was maintained at 1.5 m/s. Results of the study showed that the efficacy of the biocide to control biofilms depended on the biocide and the material. Continuous chlorination resulted in 75% reduction of viable counts on titanium, followed by 24% reduction on CuNi and 6% reduction on SS 316L surfaces, as compared to the control. When compared to continuous chlorination, increase in bacterial density in the tubes was observed at different regimes of intermittent chlorination. On SS 316L and Cu-Ni surfaces, intermittent chlorination for 1h, once every 3 h, appeared to give adequate protection. Continuous addition of chlorine dioxide resulted in 99% reduction of viable counts on titanium surfaces, followed by 28% reduction on SS 316 L surfaces and 52% reduction on Cu-Ni surfaces, as compared to the controls. The data indicate that the efficacy of biocides to control biofilms depend on not only the biocide and its frequency of application but also the material of construction. (author)

  10. 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.

  11. Polycyclic aromatic hydrocarbons in sediments of China Sea.

    Science.gov (United States)

    Li, Yanxia; Duan, Xiaoyong

    2015-10-01

    Increasing pollution pressures were placed in the coastal and estuarine ecosystems in China because of the elevated pollutants discharged from various sources. Polycyclic aromatic hydrocarbons (PAHs) in the environment were closely linked to human activities, which have been intensively studied for their geochemical interest as markers. In this review, the status of PAH contamination in China Sea was assessed by comprehensive reviews of the concentrations, sources, and fates of PAHs in sediments of China Sea. PAH concentrations in China Sea sediments decreased from north to south due to the higher emissions in North China. Atmosphere was probably the main carrier of PAHs in the north due to the higher contents of atmospheric fine particles and higher wind speeds. However, riverine inputs were probably the most important sources of PAHs in the coastal sediments of South China due to higher rainfall.

  12. Chlorine and carbon isotope measurements can help assessing the effectivenes of a zero valent iron barrier

    Science.gov (United States)

    Cretnik, S.; Audi, C.; Bernstein, A.; Palau, J.; Soler, A.; Elsner, M.

    2012-04-01

    Chlorinated aliphatic hydrocarbons (CAH's) such as trichloroethene (TCE), cis-dichloroethene (cis-DCE) and vinylchloride (VC) are extensively used in industrial applications. One of the most promising remediation techniques for CAH's in groundwater is their removal via abiotic reductive dechlorination using Zero Valent Iron (ZVI). This is applied for the treatment of contaminated sites by installing permeable reactive barriers (PRB). In this study, isotope fractionation of chlorinated ethylenes in transformation by cast iron has been investigated, because such types of iron are commonly used in PRBs. Batch experiments have been carried out in closed flasks, containing cast iron with aqueous solutions of TCE, cDCE and VC. These substrates and their respective products have been monitored by headspace samplings for their concentration (by GC-FID) and isotope fractionation of carbon and chlorine (by GC-IRMS). A decreasing reactivity trend was observed when compounds contain less chlorine atoms, with differences in rate constants of about one order of magnitude between each of the substances TCE > cDCE > VC. This resulted in the accumulation of products with fewer chlorine atoms. Therefore a similar observation can be expected if degradation in the field is incomplete, for example in the case of aged or improperly designed PRB. Pronounced carbon and chlorine isotope fractionation was measured for each of the compounds, and characteristic dual isotope plots (C, Cl) were obtained for TCE and cDCE. These results may serve as an important reference for the interpretation of isotope data from field sites, since stable isotope fractionation is widely recognized as robust indicator for such pollutant transformations. However, carbon isotope fractionation in a given parent compound may be caused by either abiotic or biotic degradation. In the field, it can therefore be difficult to delineate the contribution of abiotic transformation by PRB in the presence of ongoing

  13. 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.

  14. Behavioral toxicology, risk assessment, and chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Evangelista de Duffard, A.M.; Duffard, R. [Laboratorio de Toxicologia Experimental, Santa Fe (Argentina)

    1996-04-01

    Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a wide variety of chemicals including polychlorinated biphenyls, clioquinol, trichloroethylene, hexachlorophene, organochlorine insecticides (DDT, dicofol, chlordecone, dieldrin, and lindane), and phenoxyherbicides. Each of these chemicals has effects on motor, sensory, or cognitive function that are detectable using functional measures such as behavior. Furthermore, there is evidence that if exposure occurs during critical periods of development, many of the chlorinated hydrocarbons are developmental neurotoxicants. Developmental neurotoxicity is frequently expressed as alterations in motor function or cognitive abilities or charges in the ontogeny of sensorimotor reflexes. Neurotoxicity risk assessment should include assessments of the full range of possible neurotoxicological effects, including both structural and functional indicators of neurotoxicity. 121 refs., 1 tab.

  15. 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.

  16. 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

    2017-08-19

    This paper presents the effect of preoxidation with ferrate(VI) (Fe(VI)O4(2-), 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.

  17. Thermal diffusion of chlorine in uranium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Pipon, Y.; Toulhoat, N.; Moncoffre, N.; Jaffrezic, H.; Gavarini, S. [Inst. de Physique Nucleaire de Lyon (IPNL), Villeurbanne (France); Martin, P. [Commissariat a l' Energie Atomique (CEA), Centre de Cadarache, DEN/DEC/SESC/LLCC, Saint-Paul lez Durance (France); Raimbault, L. [Centre d' Informatique Geologique (CIG), Ecole des Mines, Fontainebleau (France); Scheidegger, A.M. [Lab. for Waste Management, Nuclear Energy and Safety Dept. (NES), Paul Scherrer Inst. Villigen PSI (Switzerland)

    2006-07-01

    In a nuclear reactor, isotopes such as {sup 35}Cl present as impurities in the nuclear fuel are activated by thermal neutron capture. During interim storage or geological disposal of nuclear fuel, the activation products such as {sup 36}Cl may be released from the fuel to the geo/biosphere and contribute to the ''instant release fraction'' as they are likely to migrate in defects and grain boundaries. In order to differentiate diffusion mechanisms due to ''athermal'' processes during irradiation from thermally activated diffusion, both irradiation and thermal effects must be assessed. This work concerns the measurement of the thermal diffusion coefficient of chlorine in UO{sub 2}. {sup 37}Cl was implanted at a 10{sup 13} at/cm{sup 2} fluence in depleted UO{sub 2} samples which were then annealed in the 900-1200 C temperature range and finally analyzed by secondary ion mass spectrometry (SIMS) to obtain {sup 37}Cl depth profiles. The migration process appears to be rather complex, involving mechanisms such as atomic, grain boundary, directed diffusion along preferential patterns as well as trapping into sinks before successive effusion. However, using a diffusion model based on general equation of transport, apparent diffusion coefficients could be calculated for 1000 and 1100 C and a mean activation energy of 4.3 eV is proposed. This value is one of the lowest values compared to those found in literature for other radionuclides pointing out a great ability of chlorine to migrate in UO{sub 2} at relatively low temperatures. In order to unequivocally determine the diffusion behaviour of both implanted and pristine chlorine before and after thermal annealing, the structural environment of chlorine in UO{sub 2} was examined using micro X-ray fluorescence (micro-XRF) and micro X-ray absorption spectroscopy (micro-XAS). (orig.)

  18. Report on the chlorine solar neutrino experiment.

    Science.gov (United States)

    Davis, R., Jr.; Lande, K.; Cleveland, B. T.; Ullman, J.; Rowley, J. K.

    New results from the chlorine solar neutrino experiment are presented. Observations of the solar neutrino flux over the period 1970 to 1988 show an average 37Ar production rate of 2.33±0.25 SNU. The 37Ar production rate exhibits an apparent anti-correlation with the solar activity cycle. The current measurements (1986 - 1988) made during minimum solar activity give an 37Ar production rate of 4.2±0.8 SNU.

  19. The gas phase chlorination of ethane

    Energy Technology Data Exchange (ETDEWEB)

    Olsbye, Unni; Myhrvold, Elisabeth M.; Slagtern, Aase; Dahl, Ivar M. [SINTEF Applied Chemistry, Oslo (Norway)

    1999-07-01

    Light alkanes are dehydrogenated to their corresponding olefins before further reactions to more valuable chemicals. The conversion of ethane to ethene in a steam cracker requires the addition of a substantial amount of heat (90 kJ/mol). Oxidative processes for ethane dehydrogenation could in principle be carried out adiabatically, however, the oxidation selectivity towards hydrogen is too low in existing systems, which leads to low ethene selectivities. This paper discusses the potential for light alkane derivatization through chlorination.

  20. The Internet Pollution

    Institute of Scientific and Technical Information of China (English)

    唐宁宁

    2005-01-01

    Life today has brought new problems. As we know, there are fourterrible pollutions in the world: water pollution, noise pollution, air pol-lution and rubbish pollution. Water pollution kills our fish and pollutesour drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution makes us hold our breath longer and be badto all living things in the world. Rubbish pollution often makes our livingenvironment much dirtier. But I think that the Internet pollution is anothernew pollution in the world.

  1. Hydraulic fracturing with chlorine dioxide cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D.A.; Newlove, J.C.; Horton, R.L.

    1990-10-23

    This patent describes a method for fracturing a subterranean formation penetrated by a wellbore. It comprises: injecting a fracturing fluid into the formation to form a vertical fracture therein, the fracturing fluid being gelled with a polymer selected from guar, guar derivatives, acrylamide, acrylamide derivatives, cellulose, cellulose derivatives, and mixtures thereof and crosslinked with an organometallic crosslinking compound and having temperature stability above about 175{degrees} F.; packing the fracture with particulate propping agent; backflowing fluids from the formation through the propped fracture to remove a portion of the polymer; injecting at matrix rates sufficient aqueous solution of chlorine dioxide down the wellbore and into the propped fracture to penetrate at least 60 feet of the propped fracture length and contact polymer in the fracturing fluid and polymer residue in the propped fracture and on the fracture walls, the amount of the chlorine dioxide in the aqueous medium being sufficient to degrade polymer in the fracturing fluid and polymer residue; permitting the chlorine dioxide to remain in contact with the polymer in the fracturing fluid and with the polymer residue on the fracture walls and in the fracture for sufficient time to degrade the polymer thereby reducing the fracturing fluid viscosity and dissolving portions of the polymer residue; and flowing formation fluid from the formation through the propped fracture and into the wellbore to remove substantial portions of the polymer and degraded polymer from the fracture.

  2. Chlorine Monoxide in the Antarctic Spring Stratosphere.

    Science.gov (United States)

    Jaramillo-Ayerbe, Mauricio

    1988-06-01

    A series of observations of stratospheric chlorine monoxide (ClO) were carried out during the austral springs of 1986 and 1987 in McMurdo Station, Antarctica, as part of two experimental campaigns sent to investigate the seasonal decrease in ozone over the antarctic continent (the ozone "hole"). Measurements of the vertical distribution of ClO were obtained by high resolution ground-based emission spectroscopy at 278 GHz, using the Stony Brook mm-wave receiver. They show the presence of an anomalous layer of lower stratospheric ClO which is not observed at other latitudes. This anomalous layer is centered at ~20 km altitude and exhibits a pronounced diurnal variation, reaching a maximum at midday and disappearing at night. During the period of Sep. 20-24, 1987, the lower-stratospheric ClO had a maximum volume mixing ratio of 1.8_sp{+0cdot5}{ -0cdot9} ppbv. A normal ClO layer centered at ~36 km was also observed, with concentrations and diurnal behavior similar to those seen in tropical latitudes. These findings are evidence of anomalous chlorine chemistry taking place in the lower stratosphere during the antarctic spring, and indicate that increasing anthropogenic chlorine is a prime causative agent in the formation of the ozone hole.

  3. Chlorine activation in the dark polar vortices

    Science.gov (United States)

    Grooß, Jens-Uwe; Spang, Reinhold; Wegner, Tobias; Rolf, Müller

    2017-04-01

    Simulations of polar stratospheric chemistry have been performed with the state-of-the-art Lagrangian Chemistry Transport Model CLaMS for both Antarctic and Arctic winters. CLaMS includes a Lagrangian sedimentation scheme that is able to successfully simulate the vertical NOy redistribution due to the sedimentation of large NAT particles. In general, observations of stratospheric trace species are very well reproduced by the model. However, during the time of the onset of chlorine activation, the simulations significantly over-estimate the HCl mixing ratio inside the polar vortex core where little sunlight is available. This discrepancy is seen in both hemispheres and points to some unrecognized process in stratospheric chemistry. The spatial and temporal development of the discrepancy is investigated in detail in order to search for possible processes missing in the model. HCl depletion rates derived from MLS observations correlate well with ice PSC detections derived from MIPAS. Possible reasons for this discrepancy in chlorine activation will be discussed. Since the discrepancy is mainly seen during the beginning of the chlorine activation period where the ozone loss rates are low, the impact on the overall ozone loss over the course of the winter and spring is rather low.

  4. Study on biodegradable aromatic/aliphatic copolyesters

    Energy Technology Data Exchange (ETDEWEB)

    Yiwang Chen; Licheng Tan; Lie Chen; Yan, Yang; Xiaofeng Wang [Nanchang University, Nanchang (China). School of Materials Science and Engineering. Inst. of Polymer Materials]. E-mail: ywchen@ncu.edu.cn

    2008-04-15

    Progress on biodegradable aromatic/aliphatic copolyesters based on aliphatic and aromatic diacids, diols and ester monomers was reviewed. The aromatic/aliphatic copolyesters combined excellent mechanical properties with biodegradability. Physical properties and biodegradability of copolyesters varied with chain length of the aliphatic polyester segment and atacticity of copolyesters. The process ability of copolyesters could be improved significantly after incorporating a stiff chain segment through copolymerization of aliphatic polyesters with an aromatic liquid crystal element. The aromatic/aliphatic copolyesters as a new type of biodegradable materials could replace some general plastics in certain applications, namely biomedical and environmental friendly fields. (author)

  5. Study on biodegradable aromatic/aliphatic copolyesters

    Directory of Open Access Journals (Sweden)

    Yiwang Chen

    2008-06-01

    Full Text Available Progress on biodegradable aromatic/aliphatic copolyesters based on aliphatic and aromatic diacids, diols and ester monomers was reviewed. The aromatic/aliphatic copolyesters combined excellent mechanical properties with biodegradability. Physical properties and biodegradability of copolyesters varied with chain length of the aliphatic polyester segment and atacticity of copolyesters. The processability of copolyesters could be improved significantly after incorporating a stiff chain segment through copolymerization of aliphatic polyesters with an aromatic liquid crystal element. The aromatic/aliphatic copolyesters as a new type of biodegradable materials could replace some general plastics in certain applications, namely biomedical and environmental friendly fields.

  6. Oxidation of diclofenac by aqueous chlorine dioxide: identification of major disinfection byproducts and toxicity evaluation.

    Science.gov (United States)

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai

    2014-03-01

    Diclofenac (DCF), a synthetic non-steroidal anti-inflammatory drug, is one of the most frequently detected pharmaceuticals in the aquatic environment. In this work, the mechanism and toxicity of DCF degradation by ClO2 under simulated water disinfection conditions were investigated. Experimental results indicate that rapid and significant oxidation of DCF occurred within the first few minutes; however, its mineralization process was longer than its degradation process. UPLC-MS and (1)H NMR spectroscopy were performed to identify major disinfection byproducts that were generated in three tentative degradation routes. The two main routes were based on initial decarboxylation of DCF on the aliphatic chain and hydroxylation of the phenylacetic acid moiety at the C-4 position. Subsequently, the formed aldehyde intermediates were the starting point for further multistep degradation involving decarboxylation, hydroxylation, and oxidation reactions of CN bond cleavage. The third route was based on transient preservation of chlorinated derivatives resulting from electrophilic attack by chlorine on the aromatic ring, which similarly underwent CN bond cleavage. Microtox bioassay was employed to evaluate the cytotoxicity of solutions treated by ClO2. The formation of more toxic mid-byproducts during the ClO2 disinfection process poses a potential risk to consumers.

  7. 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.

  8. Correlation between SUVA and DBP formation during chlorination and chloramination of NOM fractions from different sources.

    Science.gov (United States)

    Hua, Guanghui; Reckhow, David A; Abusallout, Ibrahim

    2015-07-01

    Natural organic matter (NOM) is the major precursor to the formation of disinfection byproducts (DBPs) during drinking water treatment. Specific ultraviolet absorbance (SUVA) is a widely used surrogate parameter to characterize NOM and predict its DBP formation potential. The objective of this study was to determine the relationships between SUVA and different classes of DBPs formed by NOM fractions from different sources. Three natural waters with a wide SUVA range were fractionated into differing hydrophobicity and molecular weight groups using XAD-4 and XAD-8 resins and ultrafiltration membranes. Each NOM fraction was treated with chlorine and monochloramine under controlled laboratory conditions. Different classes of DBPs showed different relationships with SUVA. SUVA correlated strongly with trihaloacetic acids (THAAs) and unknown total organic halogen (UTOX) yields whereas weak correlations were observed between SUVA and trihalomethane (THM) and dihaloacetic acid (DHAA) yields during chlorination. These results reinforce the hypothesis that DHAAs and THAAs form through different precursors and reaction pathways. Strong correlation between SUVA and UTOX was also observed during chloramination. However, no significant relationship was observed between SUVA and chloramination THMs and DHAAs. Overall, SUVA is a good indicator for the formation of unknown DBPs. This indicates that UV absorbing compounds and aromatic carbon within NOM are the primary sources of precursors for unknown DBPs.

  9. [Distribution and sources of oxygen and sulfur heterocyclic aromatic compounds in surface soil of Beijing, China].

    Science.gov (United States)

    He, Guang-Xiu; Zhang, Zhi-Huan; Peng, Xu-Yang; Zhu, Lei; Lu, Ling

    2011-11-01

    62 surface soil samples were collected from different environmental function zones in Beijing. Sulfur and oxygen heterocyclic aromatic compounds were detected by GC/MS. The objectives of this study were to identify the composition and distribution of these compounds, and discuss their sources. The results showed that the oxygen and sulfur heterocyclic aromatic compounds in the surface soils mainly contained dibenzofuran, methyl- and C2-dibenzofuran series, dibenzothiophene, methyl-, C2- and C3-dibenzothiophene series and benzonaphthothiophene series. The composition and distribution of the oxygen and sulfur heterocyclic aromatic compounds in the surface soil samples varied in the different environmental function zones, of which some factories and the urban area received oxygen and sulfur heterocyclic aromatic compounds most seriously. In Beijing, the degree of contamination by oxygen and sulfur heterocyclic aromatic compounds in the north surface soil was higher than that in the south. There were preferable linear correlations between the concentration of dibenzofuran series and fluorene series, as well as the concentration of dibenzothiophene series and dibenzofuran series. The oxygen and sulfur heterocyclic aromatic compounds in the surface soil were mainly derived from combustion products of oil and coal and direct input of mineral oil, etc. There were some variations in pollution sources of different environmental function zones.

  10. Water Pollution. Project COMPSEP.

    Science.gov (United States)

    Lantz, H. B., Jr.

    This is an introductory program on water pollution. Examined are the cause and effect relationships of water pollution, sources of water pollution, and possible alternatives to effect solutions from our water pollution problems. Included is background information on water pollution, a glossary of pollution terminology, a script for a slide script…

  11. Electric plasma discharge combustion synthesis of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Dotson, R. L.; Geren, G. W.

    1984-09-18

    A process for the production of chlorine dioxide comprises feeding an inert gas to a reaction zone and applying an electrical discharge to the inert gas to produce a high temperature plasma. Chlorine gas and oxygen gas are supplied simultaneously to the reaction zone and reacted in the plasma to produce a gaseous mixture comprised of chlorine dioxide, chlorine, oxygen and inert gas, the molar ratio of oxygen to chlorine in the reaction zone being at least about 2.5;1. The gaseous mixture is recovered from the reaction zone. Chlorine dioxide, which may be recovered as a gas or reacted to produce an alkali metal chlorite, is employed as a bleaching agent and a water treatment agent.

  12. Exposure to polycyclic aromatic hydrocarbons with special focus on cancer

    Institute of Scientific and Technical Information of China (English)

    Thamaraiselvan; Rengarajan; Peramaiyan; Rajendran; Natarajan; Nandakumar; Boopathy; Lokeshkumar; Palaniswami; Rajendran; Ikuo; Nishigaki

    2015-01-01

    Polycyclie aromatic hydrocarbons(PAHs) are a group of compounds consisting of two or more fused aromatic rings.Most of them are formed during incomplete combustion of organic materials such as wood and fossil fuels,petroleum products,and coal.The composition of PAH mixtures varies with the source and is also affected by selective weathering effects in the environment.PAHs are ubiquitous pollutants frequently found in a variety of environments such as fresh water and marine sediments,the atmosphere,and ice.Due to their widespread distribution,the environmental pollution due to PAHs has aroused global concern.Many PAHs and their epoxides are highly toxic,mutagenic and/or carcinogenic to microorganisms as well as to higher forms of life including humans.The main aim of this review is to provide contemporary information on PAH sources,route of exposure,worldwide emission rate,and adverse effects on humans,especially with reference to cancer.

  13. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part A-Monocyclic and Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-08-01

    Present study focused on the screening of bacterial consortium for biodegradation of monocyclic aromatic hydrocarbon (MAH) and polycyclic aromatic hydrocarbons (PAHs). Target compounds in the present study were naphthalene, acenaphthene, phenanthrene (PAHs), and benzene (MAH). Microbial consortia enriched with the above target compounds were used in screening experiments. Naphthalene-enriched consortium was found to be the most efficient consortium, based on its substrate degradation rate and its ability to degrade other aromatic pollutants with significantly high efficiency. Substrate degradation rate with naphthalene-enriched culture followed the order benzene > naphthalene > acenaphthene > phenanthrene. Chryseobacterium and Rhodobacter were discerned as the predominant species in naphthalene-enriched culture. They are closely associated to the type strain Chryseobacterium arthrosphaerae and Rhodobacter maris, respectively. Single substrate biodegradation studies with naphthalene (PAH) and benzene (MAH) were carried out using naphthalene-enriched microbial consortium (NAPH). Phenol and 2-hydroxybenzaldehyde were identified as the predominant intermediates during benzene and naphthalene degradation, respectively. Biodegradation of toluene, ethyl benzene, xylene, phenol, and indole by NAPH was also investigated. Monod inhibition model was able to simulate biodegradation kinetics for benzene, whereas multiple substrate biodegradation model was able to simulate biodegradation kinetics for naphthalene.

  14. A global model of tropospheric chlorine chemistry: Organic versus inorganic sources and impact on methane oxidation

    Science.gov (United States)

    Hossaini, Ryan; Chipperfield, Martyn P.; Saiz-Lopez, Alfonso; Fernandez, Rafael; Monks, Sarah; Feng, Wuhu; Brauer, Peter; Glasow, Roland

    2016-12-01

    Chlorine atoms (Cl) are highly reactive toward hydrocarbons in the Earth's troposphere, including the greenhouse gas methane (CH4). However, the regional and global CH4 sink from Cl is poorly quantified as tropospheric Cl concentrations ([Cl]) are uncertain by 2 orders of magnitude. Here we describe the addition of a detailed tropospheric chlorine scheme to the TOMCAT chemical transport model. The model includes several sources of tropospheric inorganic chlorine (Cly), including (i) the oxidation of chlorocarbons of natural (CH3Cl, CHBr2Cl, CH2BrCl, and CHBrCl2) and anthropogenic (CH2Cl2, CHCl3, C2Cl4, C2HCl3, and CH2ClCH2Cl) origin and (ii) sea-salt aerosol dechlorination. Simulations were performed to quantify tropospheric [Cl], with a focus on the marine boundary layer, and quantify the global significance of Cl atom CH4 oxidation. In agreement with observations, simulated surface levels of hydrogen chloride (HCl), the most abundant Cly reservoir, reach several parts per billion (ppb) over polluted coastal/continental regions, with sub-ppb levels typical in more remote regions. Modeled annual mean surface [Cl] exhibits large spatial variability with the largest levels, typically in the range of 1-5 × 104 atoms cm-3, in the polluted northern hemisphere. Chlorocarbon oxidation provides a tropospheric Cly source of up to 4320 Gg Cl/yr, sustaining a background surface [Cl] of methane sink of 12-13 Tg CH4/yr due the CH4 + Cl reaction ( 2.5% of total CH4 oxidation). Larger regional effects are predicted, with Cl accounting for 10 to >20% of total boundary layer CH4 oxidation in some locations.

  15. Low-temperature formation and degradation of chlorinated benzenes, PCDD and PCDF in dust from steel production.

    Science.gov (United States)

    Oberg, Tomas

    2007-08-15

    Dust from thermal processes may catalytically enhance the formation of chlorinated aromatic compounds under oxygen-rich conditions. The activities of two dust samples from electric arc furnaces and one from iron ore-based steelmaking (oxygen converter) were investigated in a laboratory experiment. The dust samples were heated at 300 degrees C for 2 h in an air atmosphere. The concentrations of chlorinated benzenes did not change greatly upon heating, while the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans decreased. The addition of copper in parallel runs resulted in a substantial increase in the concentration of chlorinated benzenes, thus indicating that the experimental setup was suitable for the evaluation of low-temperature catalysis. The outcome of the experiment seems to suggest that results cannot easily be extrapolated between different thermal and metallurgical processes. Some measures to reduce emissions, such as inhibition of catalytic activity and rapid cooling, could possibly be counterproductive when applied to off-gases from the steelmaking processes investigated here.

  16. Haloacetic acid and trihalomethane formation from the chlorination and bromination of aliphatic beta-dicarbonyl acid model compounds.

    Science.gov (United States)

    Dickenson, Eric R V; Summers, R Scott; Croué, Jean-Philippe; Gallard, Hervé

    2008-05-01

    While it is known that resorcinol- and phenol-type aromatic structures within natural organic matter (NOM) react during drinking water chlorination to form trihalomethanes (THMs), limited studies have examined aliphatic-type structures as THM and haloacetic acid (HAA) precursors. A suite of aliphatic acid model compounds were chlorinated and brominated separately in controlled laboratory-scale batch experiments. Four and two beta-dicarbonyl acid compounds were found to be important precursors for the formation of THMs (chloroform and bromoform (71-91% mol/mol)), and dihaloacetic acids (DXAAs) (dichloroacetic acid and dibromoacetic acid (5-68% mol/mol)), respectively, after 24 h at pH 8. Based upon adsorbable organic halide formation, THMs and DXAAs, and to a lesser extent mono and trihaloacetic acids, were the majority (> 80%) of the byproducts produced for most of the aliphatic beta-dicarbonyl acid compounds. Aliphatic beta-diketone-acid-type and beta-keto-acid-type structures could be possible fast- and slow-reacting THM precursors, respectively, and aliphatic beta-keto-acid-type structures are possible slow-reacting DXAA precursors. Aliphatic beta-dicarbonyl acid moieties in natural organic matter, particularly in the hydrophilic fraction, could contribute to the significant formation of THMs and DXAAs observed after chlorination of natural waters.

  17. Identification and characterization of phenylacetonitrile as a nitrogenous disinfection byproduct derived from chlorination of phenylalanine in drinking water.

    Science.gov (United States)

    Ma, Xiaoyan; Deng, Jing; Feng, Jiao; Shanaiah, Narasimhamurthy; Smiley, Elizabeth; Dietrich, Andrea M

    2016-10-01

    Unregulated disinfection byproducts (DBPs), including nitrogenous disinfection byproducts (N-DBPs), originating from chlorination of the precursor amino acid phenylalanine in aqueous systems, were identified in laboratory reactions and distributed tap. The major N-DBP identified was phenylacetonitrile, and minor DBPs of benzyl chloride, phenylacetaldehyde, 2-chlorobenzyl cyanide, and 2, 6-diphenylpyridine were also formed. Phenylacetonitrile was generated through decarboxylation, dechlorination and/or hydrolysis processes. With an aromatic structure, phenylacetonitrile has an unpleasant odor of various descriptors and an odor threshold concentration of 0.2 ppt-v as measured through gas chromatography-olfactometry. The half-life of phenylacetonitrile in reagent water and chlorinated water at 19 °C were 121 h and 792 h, respectively. The occurrence of phenylacetonitrile as an N-DBP in tap water was investigated for the first time; the results revealed that μg/L concentrations were present in nine different distributed drinking waters in China and the United States. Phenylacetonitrile deteriorates the aesthetic quality of drinking water and may present risk due to its prolonged existence in drinking water, especially in the presence of residual chlorine.

  18. Effects of air pollution on plants

    Energy Technology Data Exchange (ETDEWEB)

    Seidman, G.

    1965-01-01

    Weather, automobile exhaust, waste dumps and industrial activities are major factors in the creation of air pollution problems. The first indication of an air pollution problem is often the injury that appears on comparatively sensitive vegetation. Sulfur dioxide causes both acute and chronic plant injury. Plants especially sensitive to SO/sub 2/ are alfalfa, cosmos, sweet pea, bachelor's button, and blackberry. Fluoride causes characteristic injury on plants. Plants sensitive to fluoride injury are gladiolus, azalea, tulip, and young needles of pine. Ethylene damage to plants was initially noted in greenhouses using artificial gas for heating. Orchids and carnations are sensitive to ethylene. Ozone is highly reactive and causes typical spotting injury to the upper surface of leaves. PAN causes injury to vegetation, especially petunia and lettuce. Other pollutants also cause plant injury. Mercury vapor, chlorine gas, ammonia, H/sub 2/S, CO, and nitrogen oxides are minor hazards. Susceptibility of vegetation to air pollution depends on various things such as variety of plants, amount of moisture available to the plants, temperature, and amount of sunlight during the period of air pollution. 8 references.

  19. Method of improving formation permeability using chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McDougall, L.A.; Williams, D.A.

    1991-07-16

    This patent describes a method of treating a sandstone formation containing clays or silicates. It comprises injection a treating liquid into the formation comprising an aqueous solution of: from 50 to 4,200 ppm chlorine dioxide and from 1 to 85 volume percent of carbon dioxide; permitting the chlorine dioxide to react with material in the formation; and thereafter injecting into the formation an acid solution capable of dissolving the reaction products of chlorine dioxide and the clays and silicates.

  20. 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...

  1. Treatment of algae-induced tastes and odors by chlorine, chlorine dioxide and permanganate

    OpenAIRE

    Buffin, Lisa Webster

    1992-01-01

    Chlorine (C12(sq»' chlorine dioxide (Cl02 ) and potassium permanganate (KMn04) were evaluated as oxidants for the removal of grassy and cucumber odors associated with the pure compounds, cis-3-hexenol and trans-2, cis-6-nonadienal, respectively, and for the removal of fishy odors associated with a culture of an alga, Synura petersenii. The effects of the oxidants on the pure compounds were assessed both by Flavor Profile Analysis (FPA) and gas chromatography/mass spectrometry (GC/MS). The ef...

  2. Cyclopalladated Ferrocenylimine Catalyzed Chlorination of 2-Arylbenzoxazoles%Cyclopalladated Ferrocenylimine Catalyzed Chlorination of 2-Arylbenzoxazoles

    Institute of Scientific and Technical Information of China (English)

    冷瑜婷; 杨帆; 吴养洁; 李克

    2011-01-01

    An efficient and facile protocol for palladacycle-catalyzed chlorination of 2-arylbenzoxazoles was developed. The results represent the first examples involving the palladacycle as the catalyst for such chlorination. This chlori- nation was not a ligand-directed ortho-C--H activation, but an electrophilic substitution process at the para-position of the nitrogen atom in the benzo ring of benzoxazole moiety, the regiochemistry of which had been confirmed by HMBC spectral analysis. The catalytic system could tolerate various halogen atoms, such as F, Cl and Br, affording the corresponding products in moderate to excellent yields.

  3. Carbon and chlorine isotopologue fractionation of chlorinated hydrocarbons during diffusion in water and low permeability sediments

    Science.gov (United States)

    Wanner, Philipp; Hunkeler, Daniel

    2015-05-01

    To identify reactive processes in diffusion dominated water-saturated systems using compound-specific isotope analysis (CSIA), the effect of the diffusive transport process on isotope ratios needs to be known. This study aims to quantify the magnitude of carbon and chlorine isotopologue fractionation of two chlorinated hydrocarbons (trichloroethene (TCE) and 1,2-dichloroethane (1,2-DCA)) during diffusion in the aqueous phase and to relate for the first time laboratory with field results. Diffusion coefficient ratios in the aqueous phase were experimentally quantified with a modified Stokes diffusion cell. The experiment revealed a significant shift of carbon and chlorine isotopologue ratios of TCE and 1,2-DCA during diffusion. For both TCE and 1,2-DCA, the magnitude of the shift of chlorine isotopologue ratios was larger (TCE: D132/D130 = 0.99963 ± 0.00003; 1,2-DCA: D102/D100 = 0.99939 ± 0.00003) in comparison to carbon isotopologue ratios (TCE: D131/D130 = 0.99978 ± 0.00006; 1,2-DCA: D101/D100 = 0.99977 ± 0.00004), which is consistent with the larger mass difference between stable chlorine compared to carbon isotopes. Determined diffusion coefficients for carbon and chlorine isotopologues of TCE and 1,2-DCA follow an inverse power law form (D ∝m-β) with β < 0.5 revealing that the magnitude of isotopologue fractionation of TCE and 1,2-DCA is lower than in the previously postulated kinetic theory (D ∝m-0.5). To relate laboratory with field results, a water-saturated clay core from a VOC contaminated site was retrieved and subsampled as a function of depth to assess possible shifts in isotopologue ratios during downward diffusion of VOCs into the low permeable clay. Observed small shifts of TCE carbon and chlorine isotopologue ratio profiles were consistent with laboratory determined diffusion coefficient ratios, demonstrated by a 1D-diffusion model. Further 1D-simulations for shorter diffusion periods (5-10 years) than observed in the retrieved clay core

  4. Alkylation of organic aromatic compounds

    Science.gov (United States)

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  5. Nucleophilic fluorination of aromatic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Satyamurthy, Nagichettiar; Barrio, Jorge R

    2014-03-18

    Iodylbenzene derivatives substituted with electron donating as well as electron withdrawing groups on the aromatic ring are used as precursors in aromatic nucleophilic substitution reactions. The iodyl group (IO.sub.2) is regiospecifically substituted by nucleophilic fluoride to provide the corresponding fluoroaryl derivatives. No-carrier-added [F-18]fluoride ion derived from anhydrous [F-18](F/Kryptofix, [F-18]CsF or a quaternary ammonium fluoride (e.g., Me.sub.4NF, Et.sub.4NF, n-Bu.sub.4NF, (PhCH.sub.2).sub.4NF) exclusively substitutes the iodyl moiety in these derivatives and provides high specific activity F-18 labeled fluoroaryl analogs. Iodyl derivatives of a benzothiazole analog and 6-iodyl-L-dopa derivatives have been synthesized as precursors and have been used in the preparation of no-carrier-added [F-18]fluorobenzothiazole as well as 6-[F-18]fluoro-L-dopa.

  6. Mechanisms of inactivation of poliovirus by chlorine dioxide and iodine.

    OpenAIRE

    Alvarez, M.E.; O'Brien, R.T.

    1982-01-01

    Chlorine dioxide and iodine inactivated poliovirus more efficiently at pH 10.0 than at pH 6.0. Sedimentation analyses of viruses inactivated by chlorine dioxide and iodine at pH 10.9 showed that viral RNA separated from the capsids, resulting in the conversion of virions from 156S structures to 80S particles. The RNAs release from both chlorine dioxide- and iodine-inactivated viruses cosedimented with intact 35S viral RNA. Both chlorine dioxide and iodine reacted with the capsid proteins of p...

  7. High levels of molecular chlorine in the Arctic atmosphere

    Science.gov (United States)

    Liao, Jin; Huey, L. Gregory; Liu, Zhen; Tanner, David J.; Cantrell, Chris A.; Orlando, John J.; Flocke, Frank M.; Shepson, Paul B.; Weinheimer, Andrew J.; Hall, Samuel R.; Ullmann, Kirk; Beine, Harry J.; Wang, Yuhang; Ingall, Ellery D.; Stephens, Chelsea R.; Hornbrook, Rebecca S.; Apel, Eric C.; Riemer, Daniel; Fried, Alan; Mauldin, Roy L.; Smith, James N.; Staebler, Ralf M.; Neuman, J. Andrew; Nowak, John B.

    2014-02-01

    Chlorine radicals can function as a strong atmospheric oxidant, particularly in polar regions, where levels of hydroxyl radicals are low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone, and the oxidation of mercury to more toxic forms. Here we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We report high levels of molecular chlorine, of up to 400 pptv. Concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimate that the chlorine radicals produced from the photolysis of molecular chlorine oxidized more methane than hydroxyl radicals, on average, and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyses mercury oxidation and the breakdown of tropospheric ozone. We therefore suggest that molecular chlorine exerts a significant effect on the atmospheric chemistry of the Arctic.

  8. Accumulation of Pollutants in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    This PhD study deals with issues related to water and pollutant transport from highway surfaces caused by rain. It is essential in the study to apply methods and models in which improvements in relation to removal of pollutants can be identified and to be able to predict the yearly discharges...... of heavy metals and polycyclic aromatic hydrocarbons from an arbitrary detention pond to the natural environment. The present thesis is a part of a co-operation between the Danish Road Directorate (Vejdirektoratet) and Aalborg University and is founded in the Danish construction act for new highways...... single rain event. From the hindcast results it is possible to calculate mean water and pollutant loads. This method is commonly used in urban drainage systems for capacity analysis or for prediction of CSO's. The challenge is to develop a simplified and still accurate description of flow and transport...

  9. Persistent organic pollutants in the great lakes

    Energy Technology Data Exchange (ETDEWEB)

    Hites, R.A. (ed.) [Indiana Univ., Bloomington, IN (United States). School of Public and Environmental Affairs

    2006-07-01

    The environment around the Laurentian Great Lakes region has been adversely affected by agricultural runoff, urban waste, industrial discharge, landfill leachate, and atmospheric deposition. Although there have been some improvements over the last 20 years, persistent toxic organic pollutants are now a serious problem. This book brings together what is known about the major classes of these pollutants in the Great Lakes. Each chapter reviews our knowledge of the extent of contamination of the various parts of the Great Lakes ecosystem (air, water, sediment, fishes, birds, etc.), what is known about the trends over time of this contamination, and knowledge about the mechanisms by which these pollutants are mobilized in the lakes. Detailed information is presented on polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, pesticides, toxaphene, polychlorinated naphthalenes, polycyclic aromatic hydrocarbons, brominated flame retardants, and perfluoroalkyl acids. These reviews make this volume an invaluable resource for all those involved in environmental research, measurements, and decision making. (orig.)

  10. Atmospheric behaviors of particulate-bound polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in Beijing, China from 2004 to 2010

    Science.gov (United States)

    Tang, Ning; Suzuki, Genki; Morisaki, Hiroshi; Tokuda, Takahiro; Yang, Xiaoyang; Zhao, Lixia; Lin, Jinming; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

    2017-03-01

    Airborne particulates were collected at an urban site (site 1) from 2004 to 2010 and at a suburban site (site 2) in 2010 in Beijing. Nine polycyclic aromatic hydrocarbons (PAHs) and five nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The concentrations of PAHs and NPAHs were higher in heating season than in non-heating season at the two sites. Both the concentrations of PAHs and NPAHs decreased in the non-heating season but only the concentrations of NPAHs decreased in heating season at site 1, from 2004 to 2010. These findings suggest that source control measures implemented by the city of Beijing helped to reduce air pollution in Beijing. The concentrations of PAHs increased at site 1 in 2010, possibly because of the transport of emissions from windward other areas, such as Shanxi province. Several diagnostic ratios of PAHs and NPAHs showed that the different sources contributed to Beijing's air pollution, although coal combustion was the main source in the heating season and vehicle emission was the main source in the non-heating season. An analysis of physical parameters at Beijing showed that high wind speed can remove atmospheric PAHs and NPAHs in the heating season and that high relative humidity can remove them in the non-heating season.

  11. Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles.

    Science.gov (United States)

    Wang, Xue-Tong; Zhang, Yuan; Miao, Yi; Ma, Ling-Ling; Li, Yuan-Cheng; Chang, Yue-Ya; Wu, Ming-Hong

    2013-07-01

    Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C10 to C13 and chlorine content between 49 and 70%. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng g(-1), with a median of 9.6 ng g(-1). The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil-air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C13- and C11-congeners were predominant in most soils and C10- and C12-congeners dominated in the remaining soils. Cl7- and Cl8-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.

  12. Approaches to the Assessment of the Efficiency of Remediation of Oil-Polluted Soils

    Science.gov (United States)

    Anchugova, E. M.; Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.

    2016-02-01

    Indices characterizing the enzymatic activity of soils and the contents of aliphatic and polycyclic aromatic hydrocarbons have been applied for estimating the efficiency of remediation of oil-polluted soils in the north of European Russia. Oil-polluted test plots treated with the Universal and Roder biopreparations and subjected to the agrochemical reclamation have been examined. The suggested indices can be used to diagnose and monitor the oil-polluted soils and to assess the efficiency of their remediation.

  13. The History of Petroleum Pollution in Malaysia; Urgent Need for Integrated Prevention Approach

    OpenAIRE

    Mahyar Sakari

    2010-01-01

    Petroleum pollution is known as point and non-point source of contaminations in the environment. A major class of petroleum contaminant is groups of compounds consist of two or more fused benzene rings called polycyclic aromatic hydrocarbons (PAHs) that are carcinogenic, mutagenic and toxic. Source identification of petroleum pollution is necessary to prevent pollution entry into the environment. Eight sedimentary cores were obtained from developed and developing areas around Peninsular Malay...

  14. Deuterated polycyclic aromatic hydrocarbons: Revisited

    CERN Document Server

    Doney, Kirstin D; Mori, Tamami; Onaka, Takashi; Tielens, A G G M

    2016-01-01

    The amount of deuterium locked up in polycyclic aromatic hydrocarbons (PAHs) has to date been an uncertain value. We present a near-infrared (NIR) spectroscopic survey of HII regions in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC) obtained with AKARI, which aims to search for features indicative of deuterated PAHs (PAD or Dn-PAH) to better constrain the D/H ratio of PAHs. Fifty-three HII regions were observed in the NIR (2.5-5 {\\mu}m), using the Infrared Camera (IRC) on board the AKARI satellite. Through comparison of the observed spectra with a theoretical model of deuterated PAH vibrational modes, the aromatic and (a)symmetric aliphatic C-D stretch modes were identified. We see emission features between 4.4-4.8 {\\mu}m, which could be unambiguously attributed to deuterated PAHs in only six of the observed sources, all of which are located in the Milky Way. In all cases, the aromatic C-D stretching feature is weaker than the aliphatic C-D stretching feature, and, in the case o...

  15. The direct aromatization of methane

    Energy Technology Data Exchange (ETDEWEB)

    Marcelin, G.; Oukaci, R.; Migone, R.A.; Kazi, A.M. [Altamira Instruments, Pittsburgh, PA (United States)

    1995-12-31

    The thermal decomposition of methane shows significant potential as a process for the production of higher unsaturated and aromatic hydrocarbons when the extent of the reaction is limited. Thermodynamic calculations have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that cooling the product and reacting gases as the reaction proceeds can significantly reduce or eliminate the formation of solid carbon and heavier (C{sub 10+}) materials. Much work remains to be done in optimizing the quenching process and this is one of the goals of this program. Means to lower the temperature of the reaction are being studied as this result in a more feasible commercial process due to savings realized in energy and material of construction costs. The use of free-radical generators and catalysts will be investigated as a means of lowering the reaction temperature thus allowing faster quenching. It is highly likely that such studies will lead to a successful direct methane to higher hydrocarbon process.

  16. Persistent organic pollutants in shallow percolated water of the Alps Karst system (Zugspitze summit, Germany).

    Science.gov (United States)

    Levy, Walkiria; Pandelova, Marchela; Henkelmann, Bernhard; Bernhöft, Silke; Fischer, Norbert; Antritter, Felix; Schramm, Karl-Werner

    2017-02-01

    In the German Calcareous Alps at the Zugspitze, percolated water close to a permafrost bedrock in a tunnel system was monitored long-term for polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), and 28 organochlorine pesticides (OCP). Semi-permeable membrane devices (SPMD) were deployed in a temporary surface water system at the Zugspitze plateau and analysed for PCB, PAH, and OCP. The high-volume water sampling was successfully implemented and all compounds were identified in the water percolated through the Karst system. However, the percentage distribution of contaminants in the percolated water differed significantly from that found in surface waters. The highest chlorinated PCDD homologues were the predominant compounds of the PCDD/F family, whereas percentages of PCB #52 increased in percolated water. Toxic equivalent values (TEQ) of samples ranged from 2.0 to 4.2pgTEQ/m(3) and from 0.017 to 0.069pgTEQ/m(3) for PCDD/F and PCB, respectively. Low and intermediate molecular weight PAH were the prevailing compounds in the samples. Endosulfan sulfate, endrin, and cis-heptachlor epoxide were enhanced after water percolation through the Karst system in comparison with the surface waters (wet deposition). The relative enrichment on these pesticides was related to the environmental bedrock conditions and glacier melting sources. In summary, the Karst system highly influenced the fate of organic persistent pollutants generating different chemical patterns in their percolated waters than those found at the surface systems.

  17. Environmental Behaviors and Toxicities of Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Hayakawa, Kazuichi

    2016-01-01

    Airborne particulate matter (PM) has been collected at four cities in Japan starting in the late 1990s, at five or more major cities in China, Korea and Russia starting in 2001 and at the Noto Peninsula starting in 2004. Nine polycyclic aromatic hydrocarbons (PAHs) and eleven nitropolycyclic aromatic hydrocarbons (NPAHs) were determined by HPLC with fluorescence and chemiluminescence detections, respectively. Annual concentrations of PAHs and NPAHs were in the order, China>Russia≫Korea=Japan, with seasonal change (winter>summer). During the observation period, concentrations of PAHs and NPAHs in Japanese cities significantly decreased but the increases in the PAH concentration were observed in Chinese and Russian cities. Concentrations of PAHs and NPAHs were higher in the Northern China than those in the Southern China. At the Noto peninsula, which is in the main path of winter northwest winds and a year-round jet stream that blow from the Asian continent to Japan, the concentrations were high in winter and low in summer every year. A cluster analysis and back trajectory analysis indicated that PAHs and NPAHs were long-range transported from Northeastern China, where coal burning systems such as coal-heating boilers are considered to be the major contributors of PAHs and NPAHs. A dramatic change in atmospheric concentrations of PAHs and NPAHs in East Asia suggests the rapid and large change of PM2.5 pollution in East Asia. Considering the adverse health effects of PM2.5, continuous monitoring of atmospheric PAHs and NPAHs is necessary in this area.

  18. Noncomparative scaling of aromaticity through electron itinerancy

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Satadal [Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India); Darjeeling Polytechnic, Kurseong, Darjeeling 734203, West Bengal (India); Goswami, Tamal; Misra, Anirban, E-mail: anirbanmisra@yahoo.com [Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India)

    2015-10-15

    Aromaticity is a multidimensional concept and not a directly observable. These facts have always stood in the way of developing an appropriate theoretical framework for scaling of aromaticity. In the present work, a quantitative account of aromaticity is developed on the basis of cyclic delocalization of π-electrons, which is the phenomenon leading to unique features of aromatic molecules. The stabilization in molecular energy, caused by delocalization of π-electrons is obtained as a second order perturbation energy for archetypal aromatic systems. The final expression parameterizes the aromatic stabilization energy in terms of atom to atom charge transfer integral, onsite repulsion energy and the population of spin orbitals at each site in the delocalized π-electrons. An appropriate computational platform is framed to compute each and individual parameter in the derived equation. The numerical values of aromatic stabilization energies obtained for various aromatic molecules are found to be in close agreement with available theoretical and experimental reports. Thus the reliable estimate of aromaticity through the proposed formalism renders it as a useful tool for the direct assessment of aromaticity, which has been a long standing problem in chemistry.

  19. [Study on the corn stover lignin oxidized by chlorine dioxide and modified by furfuryl alcohol].

    Science.gov (United States)

    Sun, Yong; Zhang, Jin-ping; Yang, Gang; Li, Zuo-hu

    2007-10-01

    The Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Visible), nuclear magnetic resonance spectroscopy (1H NMR) and TG analysis were used to study the oxidation of corn stover lignin by chloride dioxide and subsequently modified by furfuryl alcohol. The results were as following: The selective oxidation of lignin by chlorine dioxide was obtained by spectroscopy study. FTIR showed that the characteristic absorbance peaks of aromatic units were decreased after chloride dioxide oxidation. The increased absorbance for the band around 1720 cm(-1) corresponding to carbonyl stretching was achieved in the oxidized lignin and the lignin modified with furfuryl alcohol. The ultraviolet-visible spectroscopy showed that the absorbance around 280 nm was largely reduced after the lignin was oxidized. The 1H NMR spectroscopy also showed the decrease of aromatic units and methoxyl group in the oxidized lignin. All these indicated the formation of muconic acid and ester, or quinone derivatives when the lignin was selectively oxidized by chloride dioxide. The modification by furfuryl alcohol made the oxidized lignin more thermally stable.

  20. 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.