Science.gov

Sample records for chlorinated hydrocarbons

  1. Process for Photochemical Chlorination of Hydrocarbons

    DOEpatents

    Beanblossom, W S

    1951-08-28

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

  2. Chlorinated hydrocarbons in peat

    SciTech Connect

    Rapaport, R.A.

    1985-01-01

    Concentrations (ng/g), accumulation rates (ug/m/sup 2/=yr) and burdens were determined for DDT (1,1,1-trichlorophenyl2-2'bis(p-chlorophenyl)ethane), polychlorinated biphenyls. Toxaphene, hexachlorobenzene (HCB) and a,b,g-hexachlorocyclohexanes (HCHs) in peat cores taken across the mid-latitudes of North America. Because peat bogs are ombrotrophic, thereby receiving all contaminant inputs from the atmosphere and because peat cores were dated, atmospheric input functions were constructed for all of the compounds listed above excepting the HCHs. Compound inventories (burdens) in peat cores of PCBs, HCB, HCHs, Toxaphene, DDT, Pb and Zn were compared, indicating a strong influence from areas proximate to industrial sources and the atmospheric transport from source regions. Untransformed parent DDT (p,p' and o,p'-DDT) in surface peat and in precipitation provides evidence for the long range transport of DDT from neighboring countries where use has increased over the past 10-15 years. Present accumulation rates of DDT in peat are about 10-20% of maximum levels associated with peak use in the US around 1960. The DDT input function that was developed can be used to date peat cores. Transformations of DDT and PCBs were also examined in peat cores. First order transformation rates of DDT (p,p' and o,p') to DDD in anaerobic peat core environments ranged from 0.03 to 0.09 yr/sup -1/ with differences related to temperature. Aerobic transformation of PCB congeners in peat cores and microcosms was rapid for 2,3 and several 4 chlorinated congeners (T/sub 1/2 less than or equal to 0.2 to 3 years) and declined with increasing chlorine number.

  3. Behavioral toxicology, risk assessment, and chlorinated hydrocarbons.

    PubMed Central

    Evangelista de Duffard, A M; Duffard, R

    1996-01-01

    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 changes 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. PMID:9182042

  4. PRODUCTION OF CHLORINE ATOMS FROM THE REACTION OF OH WITH CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Measurements from previous studies have shown that when hydroxyl radicals react with various chlorinated hydrocarbons under atmospheric conditions, free chlorine atoms can be produced. hetechnique described in this study involves scavenging Cl atoms produced by the reaction (usin...

  5. Stable isotope investigations of chlorinated aliphatic hydrocarbons.

    SciTech Connect

    Abrajano, T.; Heraty, L. J.; Holt, B. D.; Huang, L.; Sturchio, N. C.

    1999-06-01

    Stable isotope ratio measurements for carbon (C) and chlorine (Cl) can be used to elucidate the processes affecting transformation and transportation of chlorinated aliphatic hydrocarbons (CAHs) in the environment. Methods recently developed in our laboratory for isotopic analysis of CAHs have been applied to laboratory measurements of the kinetic isotope effects associated with aerobic degradation of dichloromethane (DCM) and with both anaerobic and aerobic cometabolic degradation of trichlomethene (TCE) in batch and column microbial cultures. These experimental determinations of fractionation factors are crucial for understanding the behavior of CAHs in complex natural systems, where the extent of biotransformation can be masked by dispersion and volatilization. We have also performed laboratory investigations of kinetic isotope effects accompanying evaporation of CAHs, as well as field investigations of natural attenuation and in situ remediation of CAHs in a number of contaminated shallow aquifers at sites operated by the federal government and the private sector.

  6. Hydrocarbon and chlorinated hydrocarbon-soluble magnesium dialkoxides

    SciTech Connect

    Kamienski, C.W.

    1988-05-31

    This patent describes a process for the preparation of hydrocarbon or chlorinated hydrocarbon solvent solutions of magnesium dialkoxides, which comprises reacting a suspension of magnesium metal or magnesium amide, or a solution of a dialkyimagnesium compound, in a volatile hydrocarbon or chlorinated hydrocarbon solvent with an alcohol selected from the group of (a) aliphatic, cycloaliphatic and acyclic C/sub 5/-C/sub 18/ beta- and gamma-alkyl-substituted secondary and tertiary monohydric alcohols; or (b) mixtures of the (a) alcohols with C/sub 3/-C/sub 18/ aliphatic or cycloaliphatic beta- and gamma-alkyl-unsubstituted secondary or tertiary alcohols; or (c) mixtures of the (a) alcohols with C/sub 1/-C/sub 18/ aliphatic primary unsubstituted and 2-alkyl-substituted alcohols; the mole ratios of the (a) to the (b), and the (a) to the (c), alcohols being 1 of the (a) alcohols to 0.1 to 2 of the (b) and/or the (c) alcohols.

  7. Biological monitoring of chlorinated hydrocarbon solvents

    SciTech Connect

    Monster, A.C.

    1986-08-01

    The possibility of biological monitoring of exposure to some volatile, halogenated hydrocarbons will be discussed. Most of these agents are widely used as solvents. All agents act on the nervous system as narcotics and differ widely in toxicity. Most of the solvents undergo biotransformation to metabolites. This allows biological assessment of exposure by measurement of the solvent and/or metabolites in exhaled air, blood, and/or urine. However, the same metabolites may occur with exposure to different chlorinated hydrocarbons, eg, trichloroethanol and trichloroacetic acid from exposure to trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane. On the other hand, these agents differ widely in the percentage that is metabolized. There are large gaps in our knowledge, however, and much research will have to be carried out before even tentative data can be established for most of the solvents.

  8. ENZYME-BASED DETECTION OF CHLORINATED HYDROCARBONS IN WATER

    EPA Science Inventory

    An enzyme-based approach for detecting hazardous levels of high molecular weight chlorinated hydrocarbons in natural waters has been explored. An extensive review of the literature indicated that the enzymes, lactate dehydrogenase, carbonic anhydrase, hexokinase, phosphorylase an...

  9. PCB's and chlorinated hydrocarbon pesticides in Antarctic atmosphere and hydrosphere

    SciTech Connect

    Tanabe, S.; Hidaka, H.; Tatsukawa, R.

    1983-01-01

    PCBs and chlorinated hydrocarbon pesticides such as DDTs and HCHs (BHCs) were measured in air, water, ice and snow samples collected around the Japanese research stations in Antarctica and adjacent oceans during December 1980 to March 1982. The atmospheric concentrations of chlorinated hydrocarbons decreased in the transport process from northern lands to Antarctica, but the compositions of PCBs, DDT compounds and HCH isomers were relatively uniform throughout this process. Regional and seasonal variations were found in aerial concentrations of these pollutants at Syowa Station and adjacent seas in Antarctica. Chlorinated hydrocarbons were also detected in snow, ice, lake water and sea water samples, in which rather high concentrations were found in snow and ice samples. This suggests that snow and ice serve as media of supply of these pollutants into Antarctic marine environment.

  10. Influence of humic substances on the formation of chlorinated polycyclic aromatic hydrocarbons during chlorination of polycyclic aromatic hydrocarbon polluted water

    SciTech Connect

    Johnsen, S.; Gribbestad, I.S.

    1988-08-01

    Chlorinated polycyclic aromatic hydrocarbons (PAH) are present at nanogram per liter levels in lake water. Some of these compounds are known to be mutagenic in the Ames Salmonella test. The PAH compounds fluorene, anthracene, fluoranthene, and benzo(a)pyrene were dissolved in lake water with low humus content and in humus water with 9.17 mg of total organic carbon/L, followed by sodium hypochlorite chlorination at different concentrations. Reaction of PAH and formation of chlorinated PAH were measured by cyclohexane extraction of the samples 3 days after chlorination and gas chromatography/mass spectrometry analyses of the extracts. The PAH-chlorine reaction was found to be dependent upon the concentration of free active chlorine in the water, and the presence of humic substances was found to affect the formation of chlorinated PAH. Chlorinated PAH were formed in the lake water samples of fluoranthene and benzo(a)pyrene, but no chlorinated PAH were detected in the presence of humic substances.

  11. Shock-tube pyrolysis of chlorinated hydrocarbons - Formation of soot

    NASA Technical Reports Server (NTRS)

    Frenklach, M.; Hsu, J. P.; Miller, D. L.; Matula, R. A.

    1986-01-01

    Soot formation in pyrolysis of chlorinated methanes, their mixtures with methane, and chlorinated ethylenes were studied behind reflected shock waves by monitoring the attenuation of an He-Ne laser beam. An additional single-pulse shock-tube study was conducted for the pyrolysis of methane, methyl chloride, and dichloromethane. The experiments were performed at temperatures 1300-3000 K, pressures of 0.4-3.6 bar, and total carbon atom concentrations of 1-5 x 10 to the 17th atoms cu cm. The amounts of soot produced in the pyrolysis of chlorinated hydrocarbons are larger than that of their nonchlorinated counterparts. The sooting behavior and product distribution can be generally explained in terms of chlorine-catalyzed chemical reaction mechanisms. The pathway to soot from chlorinated methanes and ethylenes with high H:Cl ratio proceeds via the formation of C2H, C2H2, and C2H3 species. For chlorinated hydrocarbons with low H:Cl ratio, the formation of C2 and its contribution to soot formation at high temperatures becomes significant. There is evidence for the importance of CHCl radical and its reactions in the pyrolysis of dichloromethane.

  12. TURBULENT FLAME REACTOR STUDIES OF CHLORINATED HYDROCARBON DESTRUCTION EFFICIENCY

    EPA Science Inventory

    Four mixtures of C1 and C2 chlorinated hydrocarbons, diluted in heptane, were burned in a Turbulent Flame Reactor (TFR) under high and low oxygen conditions. Emissions of undestroyed feed, stable organic by-products, carbon monoxide, carbon dioxide and oxyg...

  13. USE OF SONOCHEMISTRY IN MONITORING CHLORINATED HYDROCARBONS IN WATER

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has been examining the potential of combining sonication with available measurement technologies for monitoring chlorinated hydrocarbons in water. The chloride ion (C1-) concentration, conductivity, and pH were measured before and af...

  14. Transformation of Chlorinated Hydrocarbons on Synthetic Green Rusts

    EPA Science Inventory

    Green rusts (GRs) are layered double hydroxides that contain both ferrous and ferric ions in their structure. GRs can potentially serve as a chemical reductant for degradation of chlorinated hydrocarbons. GRs are found in zerovalent iron based permeable reactive barriers and in c...

  15. MICROEMULSION FORMATION WITH MIXED CHLORINATED HYDROCARBON LIQUIDS

    EPA Science Inventory

    Mixing rules for water/chlorocarbon/anionic-surfactant systems have been studied. t was found that the behavior of chlorocarbons parallels the ideal mixing rules for hydrocarbons. he polarity of some chlorocarbons prevented a direct determination of electrolyte concentration and ...

  16. SOURCE RECEPTOR METHODOLOGY FOR SOME CHLORINATED HYDROCARBONS

    EPA Science Inventory

    A source-receptor methodology is described that can be used to estimate emission rates of halogenated hydrocarbons from a manufacturing plant when access to the plant is not possible. An inert tracer is released at a known rate from a vehicle traveling back and forth on a road ou...

  17. Estimating The Thermodynamics And Kinetics Of Chlorinated Hydrocarbon Degradation

    SciTech Connect

    Bylaska, Eric J.

    2006-08-01

    Many different degradation reactions of chlorinated hydrocarbons are possible in natural ground waters. In order to identify which degradation reactions are important, a large number of possible reaction pathways must be sorted out. Recent advances in ab initio electronic structure methods have the potential to help identify relevant environmental degradation reactions by characterizing the thermodynamic properties of all relevant contaminant species and intermediates for which experimental data is usually not available, as well as provide activation energies for relevant pathways. In this paper, strategies based on ab initio electronic structure methods for estimating thermochemical and kinetic properties of reactions with chlorinated hydrocarbons are presented. Particular emphasis is placed on strategies that are computationally fast and can be used for large organochlorine compounds such as 4,4?-DDT.

  18. Process for treating liquid chlorinated hydrocarbon wastes containing iron

    SciTech Connect

    Doane, E.P.

    1986-09-30

    A process is described for reducing the ferric chloride content of liquid waste streams comprising higher boiling chlorinated hydrocarbons and containing amounts of ferric chloride. The process consists essentially of contacting the waste stream with an amount of water sufficient to convert ferric chloride contained in the stream to solid ferric chloride hexahydrate, and then removing the solid hexahydrate by filtration or centrifugation from the waste stream.

  19. Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons

    DOEpatents

    Fliermans, Carl B.

    1989-01-01

    A chlorinated aliphatic hydrocarbon-degrading microorganism, having American Type Culture Collection accession numbers ATCC 53570 and 53571, in a biologically pure culture aseptically collected from a deep subsurface habitat and enhanced, mineralizes trichloroethylene and tetrachloroethylene to HCl, H.sub.2 O and Co.sub.2 under aerobic conditions stimulated by methane, acetate, methanol, tryptone-yeast extract, propane and propane-methane.

  20. Iron enhanced abiotic degradation of chlorinated hydrocarbons

    SciTech Connect

    Chen, C.T.

    1995-10-01

    Since the 1970s, several researchers have investigated the ability of certain zero-valent metals or alloys to enhance the degradation of halogenated organic compounds in contaminated water. Iron, zinc, aluminum, brass, copper, and stainless steel have been studied at various times with varying degrees of success. Gillham and O`Hannesin have recently made a literature review and conducted tests on 14 halogenated aliphatic compounds using zero-valent iron as an enhancing agent. The results showed that rapid dehalogenation occurred on all of the compounds tested except dichloromethane. Based on these test results, EnviroMetal Technologies, Inc. proposed to remediate groundwater contaminated with chlorinated organic compounds using this technology. The EPA Superfund Innovative Technology Evaluation (SITE) program has accepted this technology for demonstration. This demonstration project will include two processes, above ground reactor and in situ permeable wall. The demonstration on the above ground reactor is being conducted at a site in Wayne, New Jersey. The main contaminants at this site are tetrachloroethene (PCE) and trichloroethene (TCE). The in situ permeable wall process will be conducted at a site in upstate New York. This site is a shallow sand aquifer containing TCE, dichloroethenes, and 1,1,1-trichloroethane.

  1. Chlorinated hydrocarbons in flatfishes from the Southern California, USA, Bight

    SciTech Connect

    Schiff, K.; Allen, M.J.

    2000-06-01

    Although inputs of chlorinated hydrocarbon compounds to the Southern California Bight (SCB) are presently low, historical deposits represent a source of bioaccumulation potential to sediment-associated fauna. To assess this bioaccumulation potential, 14 chlorinated hydrocarbon classes were measured in livers of three species of flatfish collected from 63 randomly selected sites on the coastal shelf between Point Conception and the United States-Mexico international border. Tissue contamination was widespread throughout the SCB, but was limited to just two chlorinated hydrocarbon classes. Virtually 100% of Pacific sanddab (Citharichthys sordidus) and longfin sanddab (Citharichthys xanthostigma) populations were estimated to be contaminated with dichlorodiphenyltrichloroethane (total DDT = sum of o.p{prime} and p,p{prime} isomers of DDT + dichlorodiphenyldichloroethylene [DDE] + dichlorodiphenyldichloroethane [DDD]) and/or polychlorinated biphenyls (total PCBs). Total DDT also contaminated the majority (64%) of the Dover sole (Microstomus pacificus) population in the SCB. Total PCB measurements in tissues of SCB flatfish were dominated by 12 congeners (52, 66, 87, 101, 105, 118, 128, 138, 153, 170, 180, and 187), which averaged 95% of the combined mass of the 27 congeners analyzed. Sediment concentrations accounted for most of the variability observed in tissue concentrations for 8 of these 12 congeners and total PCBs. Normalized sediment concentrations were also significantly correlated to normalized tissue concentrations for total DDT and p,p{prime}-DDE. Tissue concentrations measured in this study from reference areas of the SCB were compared to tissue concentrations measured form reference areas in studies conducted in 1977 and 1985. Total DDT and total PCB liver concentrations were found to have decreased one to two orders of magnitude in pacific and longfin sanddabs between 1985 and 1994. Total DDT and total PCB liver concentrations decreased 5- to 35-fold in

  2. Supported metal nanoparticles for the remediation of chlorinated hydrocarbons

    NASA Astrophysics Data System (ADS)

    Schrick, Bettina

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

  3. A chemical kinetic modeling study of chlorinated hydrocarbon combustion

    SciTech Connect

    Pitz, W.J.; Westbrook, C.K.

    1990-09-05

    The combustion of chloroethane is modeled as a stirred reactor so that we can study critical emission characteristics of the reactor as a function of residence time. We examine important operating conditions such as pressure, temperature, and equivalence ratio and their influence on destructive efficiency of chloroethane. The model uses a detailed chemical kinetic mechanism that we have developed previously for C{sub 3} hydrocarbons. We have added to this mechanism the chemical kinetic mechanism for C{sub 2} chlorinated hydrocarbons developed by Senkan and coworkers. In the modeling calculations, sensitivity coefficients are determined to find which reaction-rate constants have the largest effect on destructive efficiency. 24 refs., 6 figs., 1 tab.

  4. Carbon and chlorine isotopologue fractionation of chlorinated hydrocarbons during diffusion in water and low permeability sediments

    NASA Astrophysics Data System (ADS)

    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

  5. Electron beam degradation of chlorinated hydrocarbons in air

    NASA Astrophysics Data System (ADS)

    Prager, L.; Langguth, H.; Rummel, S.; Mehnert, R.

    1995-09-01

    Using a low-energy electron accelerator (180 keV, 3 kW) synthetic air polluted with chlorinated hydrocarbons such as cis-dichloro-, trichloro- and perchloroethene was irradiated in a flow system. Already at doses of 2.5 kGy, more than 90 vol% of the initial pollutant concentration (2-50 ppm) could be removed. As main products HCl, CO, chloromethanes, chloroacetyl chlorides and phosgene were identified. After hydrolysis of phosgene and chloroacteyl chlorides in a wet scrubbing system, the chlorine balance shows nearly complete mineralization of the pollutants to HCl, CO and CO2. Less than 5 vol% of chloromethanes and about 0.1 vol% chloroacetic acids were detected after irradiation and hydrolysis. An attempt is made to describe the degradation mechanism as OH radical induced chain reaction. The OH radical adds to the ethene double bond. The resulting adduct releases a chlorine radical. In presence of oxygen a chain reaction is initiated by this radical, which leads to decomposition of the chloroethenes.

  6. Electrochemical SERS detection of chlorinated hydrocarbons in aqueous solutions

    SciTech Connect

    Storey, J.M.E.; Shelton, R.D.; Barber, T.E.; Wachter, E.A. )

    1994-10-01

    An [ital in] [ital situ] method for the determination of trichloroethylene (TCE), perchlorethylene (PCE), chloroform (CHCl[sub 3]) and carbon tetrachloride (CCl[sub 4]) in aqueous solution is described. The method is based on ESERS-a combination of electrochemical methods and surface-enhanced Raman scattering (SERS). Electrochemistry prepares the surface of a copper electrode for SERS and concentrates the analyte on the surface. The formation of common reaction products for chloroalkanes and for chloroalkenes prevents unequivocal differentiation within a specific class of chlorinated hydrocarbons. However, spectroscopic selectivity between the chloroalkane and chloroalkene classes is excellent, while differences in electrochemical response provide a secondary means for differentiating analyte class. Sensitivity was found to be: [lt]1 ppm for TCE; 15 ppm for PCE; 15 ppm for CHCl[sub 3]; and 10 ppm for CCl[sub 4]. Application of the method to groundwater contaminated with TCE has been demonstrated. In combination with a fiber-optic waveguide, the ESERS technique offers potential for remote detection of chlorinated hydrocarbons in groundwater and remediation process streams.

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

    NASA Astrophysics Data System (ADS)

    Sunkara, Bhanu Kiran

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

  8. Effects of chlorinated hydrocarbon insecticides upon quail and pheasants

    USGS Publications Warehouse

    DeWitt, J.B.

    1955-01-01

    Previous studies had shown that heavy or repeated applications of DDT resulted in decreases.in bird populations, but long-range effects of this and other chlorinated hydrocarbon insecticides had not been fully evaluated. Experiments were conducted to determine toxiCitY to quail and pheasants of aldrin, dieldrin, endrin, and strobane, and to determine effects of these compounds upon survival, growth, and reproduction....Feeding of diets containing 0.02% DDT to breeding quail resulted in significant decreases in hatchability of eggs and in viability of chiCks. Similar results were obtained by feeding 0.001% dieldrin, but effects upon reproduct.ion of short-term feeding of aldrin and endrin could not be determined....Aldrin, dieldrin, and endrin were lethal to both male and female quail when fed at levels of 0.0005% in the diets. Female pheasants appeared more resistant than males to the effects of these compounds.

  9. Bioconcentration of chlorinated hydrocarbons from sediment by oligochaetes

    SciTech Connect

    Connell, D.W.; Bowman, M.; Hawker, D.W.

    1988-12-01

    Previously published data on the accumulation of 15 chlorinated hydrocarbons from sediment by oligochaetes have been interpreted on the basis of bioconcentration from interstitial water. Calculation of the interstitial water concentration allowed determination of uptake and clearance rate constants together with bioconcentration factors (KB) for these compounds. These three factors each exhibited a systematic relationship to the octanol/water partition coefficient (KOW). The log KB versus log KOW relationship was roughly linear over the log KOW range from 4.4 to 6.4 and displayed an increasing nonlinear deviation for log KOW values greater than 6.4. These relationships are qualitatively similar to those established for other aquatic organisms where bioconcentration from water was the mechanism involved. This suggests that interstitial water may be the phase from which lipophilic compounds in sediment are bioconcentrated by oligochaetes. An expression relating the bioconcentration factor to the biotic concentration and various sediment characteristics has also been developed.

  10. A New, Rapid, Precise and Sensitive Method for Chlorine Stable Isotope Analysis of Chlorinated Aliphatic Hydrocarbons

    NASA Astrophysics Data System (ADS)

    van Acker, M. R.; Shahar, A.; Young, E. D.; Coleman, M. L.

    2005-12-01

    Chlorinated aliphatic hydrocarbons (CAH) are recognized common groundwater contaminants. Because of their physico-chemical properties, their lifespan in groundwater is in the order of decades (Pankow and Cherry, 1996). Stable isotopes can play a role in determining the rate and extent of CAH attenuation (Slater, 2003). The use of chlorine has been hampered by the current time consuming and insensitive analytical methods. We present a new analytical procedure to measure chlorine stable isotope values using a gas chromatograph coupled to a multi-collector inductively coupled mass spectrometer (GC-MC-ICP-MS). The GC has a Porapack Q packed column. The carrier gas was helium and the temperature was constant at 160°C. The GC was coupled to the MC-ICP-MS by heated stainless steel tubing. Our high resolution spectra showed that 37Cl is free of its main interference 36Ar-H over a range of 0.004 amu. Two pure CAH, trichloroethene (TCE) and tetrachloroethene (PCE), were used for zero enrichment (sample relative to itself) and standard-sample difference measurements. Integrations and background corrections of transient signals were performed using Microsoft Excel after import of the raw data from the MC-ICPMS acquisition software. Zero enrichment tests with TCE and PCE yielded δ37Cl of -0.04±0.16‰ and -0.03±0.17‰, respectively, results for sample injections of 0.12 to 0.02 microliters. Accuracy was tested by injecting 0.24 microliters of a 50/50 mixture of TCE and PCE of known isotopic compositions as the difference between the two solvents was of paramount interest. The δ37Cl(TCE) value of PCE was -1.99±0.16‰. A highly satisfactory comparison with the conventional method is shown by published values for TCE and PCE, -2.04±0.12‰ and -0.30±0.14‰, respectively (Jendrzejewski et al., 2001), giving a δ37Cl(TCE) value for PCE of -2.34±0.18‰. These tests of the GC-MC-ICP-MS method showed that we can obtain reproducible and accurate Cl isotope values using an

  11. Trends in chlorinated hydrocarbon levels in Hudson River basin sediments.

    PubMed Central

    Bopp, R F; Chillrud, S N; Shuster, E L; Simpson, H J; Estabrooks, F D

    1998-01-01

    Analysis of sections from dated sediment cores were used to establish geographic distributions and temporal trends of chlorinated hydrocarbon contaminant levels in sediments from natural waters of the Hudson River basin. Radiometric dating was based primarily on the depth distribution of 137(Cs) in the cores and on the occurrence of detectable levels of 7(Be) in surface sediment samples. Eighteen sampling sites included several along the main stem of the Hudson, its major tributaries, and components of the New York/New Jersey (NY/NJ) harbor complex. Drinking-water reservoirs were sampled to place upper limits on atmospheric inputs. Core sections were analyzed for polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT)-derived compounds, chlordane, and dioxins. Sediment concentrations of most contaminants at most sites have decreased significantly since the mid-1960s. The data provide a basinwide perspective on major point-source inputs of PCBs to the upper Hudson River and of 2,3,7,8-tetrachlorodibenzo-p-dioxin and DDT to the lower Passaic River. Evidence was found for significant but poorly characterized sources of PCBs and chlordane to the western NY/NJ harbor, and of highly chlorinated dioxins to the upstream sites on the main stem of the Hudson. The results indicate that analysis of dated sediment samples is a most effective and efficient monitoring tool for the study of large-scale geographic and temporal trends in levels of particle-associated contaminants. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:9703496

  12. CHLORINATED HYDROCARBON DEGRADATION IN PLANTS: MECHANISMS AND ENHANCEMENT OF PHYTOREMEDIATION OF GROUNDWATER CONTAMINATION

    EPA Science Inventory

    Several varieties of transgenic poplar containing cytochrome P-450 2E1 have been constructed and are undergoing tests. Strategies for improving public acceptance and safety of transgenic poplar for chlorinated hydrocarbon phytoremediation are being developed. We have discovered a...

  13. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 22. METHOD 612-CHLORINATED HYDROCARBONS

    EPA Science Inventory

    An interlaboratory study in which 20 laboratories participated was conducted to provide precision and accuracy statements for the proposed EPA Method 612 - Chlorinated Hydrocarbons for measuring concentrations of the Category 3 chemicals hexachloroethane, hexachlorobutadiene, 2-c...

  14. ANAEROBIC TRANSFORMATION OF CHLORINATED ALIPHATIC HYDROCARBONS IN A SAND AQUIFER BASED ON SPATIAL CHEMICAL DISTRIBUTIONS

    EPA Science Inventory

    We estimated the distribution of chlorinated aliphatic hydrocarbons (CAHs) from groundwater samples collected along three transects in a sand aquifer. richloroethylene (TCE) leaked and contaminated the aquifer probably more than a decade before we collected the measurements. he d...

  15. CHEMICAL DISTRIBUTION AND ANAEROBIC TRANSFORMATION OF CHLORINATED ALIPHATIC HYDROCARBONS IN A SAND AQUIFER

    EPA Science Inventory

    We estimated the distribution of chlorinated aliphatic hydrocarbons (CAHS) from groundwater samples collected along three transects in a sand aquifer. richloroethylene (TCE) leaked and contaminated the aquifer probably more than a decade before we collected the measurements. he d...

  16. Chlorinated hydrocarbons in plant foliage: an indication of the tropospheric contamination level

    SciTech Connect

    Gaggi, C.; Bacci, E.; Calamari, D.; Fanelli, R.

    1985-01-01

    Levels of some chlorinated hydrocarbons in foliage from the Italian peninsula and other countries of the world are reported. The use of plant leaves in monitoring and for a prediction of potential environmental distribution of persistent hydrophobic pollutants is discussed.

  17. RELATIONSHIPS BETWEEN LABORATORY AND PILOT-SCALE COMBUSTION OF SOME CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Factors governing the occurence of trace amounts of residual organic substance emmissions (ROSEs) in full-scale incierators are not fully understood. Pilot-scale spray combustion expereiments involving some liquid chlorinated hydrocarbons (CHCs) and their dilute mixtures with hy...

  18. Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

    DOEpatents

    Knauss, Kevin G.; Copenhaver, Sally C.; Aines, Roger D.

    2000-01-01

    In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

  19. Accumulation and diagenesis of chlorinated hydrocarbons in lacustrine sediments

    USGS Publications Warehouse

    Elsenreich, S.J.; Capel, P.D.; Robbins, J.A.; Bourbonniere, R.

    1989-01-01

    Two sediment cores were taken from the Rochester Basin of eastern Lake Ontario and analyzed for the radionuclides 210Pb and 137Cs and several high molecular weight chlorinated hydrocarbons (CHs). The two sites are geographically proximate but differ in sedimentation rate, permitting sedimentation-dependent processes to be factored out. The 210Pb chronology showed a mixed depth of 3-5 cm and an intrinsic time resolution of 11-14 years. Vertically integrated numbers of deposit-feeding oligochaete worms and burrowing organisms are insufficient to homogenize the sediment on the time scale of CH inputs, which are non steady state. U.S. production and sales of polychlorinated biphenyls (PCBs), DDT, Mirex, and hexachlorobenzene (HCB), as determinants of the shape of the input function, adequately predict the overall shape and, in many cases, details in the sedimentary profile. Sediment focusing factors (FF) inferred from 137Cs and 210Pb inventories averaged 1.17 and 1.74 for cores E-30 and G-32, respectively. This permitted CH accumulation rates to be corrected for focusing. Apparent molecular diffusion coefficients modeled for many of the CHs were about (1-3) ?? 10-9 cm2/s.

  20. Persistence of chlorinated hydrocarbon contamination in a California marine ecosystem

    SciTech Connect

    Young, D.R.; Gossett, R.W.; Heesen, T.C.

    1989-01-01

    Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, U.S.A.) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator (Dover sole, Microstomus pacificus) collected near the submarine outfall. Concentrations of these pollutants in the soft tissues of the mussel Mytilus californianus, collected intertidally well inshore of the highly contaminated bottom sediments, followed much more closely the decreases in the outfall discharges. These observations suggest that contaminated sediments on the seafloor were the principal (although not necessarily direct) cause of the relatively high and persistent concentrations of DDT and PCB residues in tissues. The study indicated that residues of the higher-molecular-weight chlorinated hydrocarbons, such as DDT and PCB, can be highly persistent once released to coastal marine ecosystems and that their accumulation in surficial bottom sediments is the most likely cause of this persistence observed in the biota of the discharge zone.

  1. Hydrocarbon-solvent based cleaners as replacements for chlorinated and CFC solvents

    SciTech Connect

    Schreiner, J.L.; Berlin, E.P.

    1995-12-31

    Chlorinated and CFC solvents have been used for about 30 years to remove various contaminants from products during the manufacturing process. Among the contaminants being removed are oils, greases, and waxes that have petroleum products as the base. Prior to the advent of the chlorinated solvents petroleum distillates were used for these cleaning operations. Processing improvements over the past 30 years now permit production of higher purity hydrocarbons solvents that can be used as replacements for the chlorinated and CFC solvents being phased out. These hydrocarbon solvents are well suited for removal of the various petroleum based contaminants, as one recalls the old adage {open_quotes}like dissolves like.{close_quotes}

  2. Assimilation of chlorinated alkanes by hydrocarbon-utilizing fungi

    SciTech Connect

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

    1984-12-01

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

  3. BIOTRANSFORMATION OF MIXTURES OF CHLORINATED ALIPHATIC HYDROCARBONS BY AN ACETATE-GROWN METHANOGENIC ENRICHMENT CULTURE. (R825549C053)

    EPA Science Inventory

    Biotransformation of chlorinated aliphatic hydrocarbons under anaerobic conditions has received considerable attention due to the prevalence of these compounds as groundwater contaminants. However, information concerning the impact of mixtures of chlorinated compounds on their...

  4. CHEMICAL INDUCTION OF TUMORS IN OYSTERS BY A MIXTURE OF AROMATIC AND CHLORINATED HYDROCARBONS, AMINES, AND METALS

    EPA Science Inventory

    Tumors were induced in eastern oysters (Crassotrea virginica) by a mixture f aromatic hydrocarbons, an aromatic amine, polychlori-nated biphenyls, chlorinated hydrocarbons, a nitrosoamine and heavy metals. idney and nteric tumors developed in oysters following exposure to a mixtu...

  5. Method for removing chlorine compounds from hydrocarbon mixtures

    DOEpatents

    Janoski, E.J.; Hollstein, E.J.

    1984-09-29

    A process for removing halide ions from a hydrocarbon feedstream containing halogenated hydrocarbons wherein the contaminated feedstock is contacted with a solution of a suitable oxidizing acid containing a lanthanide oxide, the acid being present in a concentration of at least about 50 weight percent for a time sufficient to remove substantially all of the halide ion from the hydrocarbon feedstock.

  6. Method for removing chlorine compounds from hydrocarbon mixtures

    DOEpatents

    Janoski, Edward J.; Hollstein, Elmer J.

    1985-12-31

    A process for removing halide ions from a hydrocarbon feedstream containing halogenated hydrocarbons wherein the contaminated feedstock is contacted with a solution of a suitable oxidizing acid containing a lanthanide oxide, the acid being present in a concentration of at least about 50 weight percent for a time sufficient to remove substantially all of the halide ion from the hydrocarbon feedstock.

  7. In-situ demonstration of radio-frequency enhanced chlorinated hydrocarbon remediation

    SciTech Connect

    Kasevich, R.S.; Price, S.L.; Faust, D.L.; Jarosch, T.R.

    1994-06-01

    This paper discusses the results of a successful demonstration of radio frequency (RF) heating for enhanced chlorinated hydrocarbon remediation at the M-Area Seepage Basin of the Department of Energy`s Savannah River Site. RF heating was integrated with soil vapor extraction (SVE) to enhance the release of residual volatile chlorinated hydrocarbons which are concentrated in low permeable clay lenses in the unsaturated zone. Participants in this effort consisted of the Westinghouse Savannah River Technology Center; the Westinghouse Science and Technology Center (Pittsburgh, PA); and KAI Technologies, Inc. which provided the RF technology. Additionally, a better understanding of RF heating technology is gained through a description of the RF heating system.

  8. Formation of stable chlorinated hydrocarbons in weathering plant material

    SciTech Connect

    Myneni, Satish C. B.

    2001-10-01

    Though several chlorinated organic compounds produced by humans are carcinogenic and toxic, some are also produced by the biotic and abiotic processes in the environment. In situ x-ray spectroscopy data indicate that natural organic matter in soils, sediments, and natural waters contain stable, less volatile organic compounds with chlorinated phenolic and aliphatic groups as the principal Cl forms. These compounds are formed at rapid rates from the transformation of inorganic Cl during humification of plant material and, thus, play a critical role in the cycling of Cl and of several major and trace elements in the environment and may influence human health. [References: 19

  9. Determination of PCBs and chlorinated hydrocarbons in marine mammal tissues.

    PubMed

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

    1993-11-01

    Selected tissues (blubber, liver, kidney and muscle) from marine mammals, which were collected as part of the Alaska Marine Mammal Tissue Archival Project (AMMTAP), were analyzed for polychlorinated biphenyl (PCB) congeners and chlorinated pesticides. Concentrations of these compounds in the different tissues were compared and blubber was selected as the primary tissue for organic contaminant analyses for the AMMTAP based on higher levels (1-2 orders of magnitude) in this tissue compared to liver, kidney and muscle. Concentrations for 15 PCB congeners and 12 chlorinated pesticides are reported for 10 different animals of three species (northern fur seal, ringed seal and belukha whale) from five different sites. PMID:8272838

  10. Chlorinated hydrocarbons and eggshell changes in raptorial and fish-eating birds

    USGS Publications Warehouse

    Hickey, J.J.; Anderson, D.W.

    1968-01-01

    Catastrophic declines of three raptorial species in the United States have been accompanied by decreases in eggshell thickness that began in 1947, have amounted to 19 percent or more, and were identical to phenomena reported in Britain. In 1967, shell thickness in herring gull eggs from five states decreased with increases in chlorinated hydrocarbon residues.

  11. Transfer of chlorinated hydrocarbons in the food chain lichen > reindeer > man

    SciTech Connect

    Villeneuve, J.P.; Holm, E.; Cattini, C.

    1985-01-01

    Lichen Caladonia alpestris collected in the Northern part of Sweden were analyzed together with samples of reindeer and wolf living in the same area. From these results one can estimate the annual intake of these compounds by Lapplanders. The amount ingested by lapplanders is far below the maximum permissible limit set for the intake of chlorinated hydrocarbons through food.

  12. Chlorinated hydrocarbons in lichen and moss samples from the Antarctic Peninsula

    SciTech Connect

    Bacci, E.; Calamari, D.; Gaggi, C.; Fanelli, R.; Focardi, S.; Morosini, M.

    1986-01-01

    The concentrations of some chlorinated hydrocarbon residues (HCB, HCH isomers, p,p'DDT and DDE, PCB cogeners) in lichen and moss samples from the Antarctic Peninsula are reported and compared with available data from other parts of the world. The use of these materials as indicators of tropospheric contamination levels in Antarctica is discussed.

  13. Modeling the national chlorinated hydrocarbon supply chain and effects of disruption.

    SciTech Connect

    Sun, Amy Cha-Tien; Downes, Paula Sue; Blair, Angela S.; Welk, Margaret Ellen

    2010-03-01

    Chlorinated hydrocarbons represent the precursors for products ranging from PVC and refrigerants to pharmaceuticals. Natural or manmade disruptions that affect the availability of these products nationally have the potential to affect a wide range of markets, from healthcare to construction. Sandia National Laboratories (Sandia) has developed datasets and models that allow the analysis of the interdependencies within the chlorine chemical supply chain and consequences of disruptions. Combining data on plant locations, transportation, utilities, and the chemical supply chain itself, with modeling tools such as N-ABLE, a Sandia-developed agent based modeling system, allows Sandia to model this complex system dynamically. Sandia has used the N-ABLE technology to simulate a disruption to the chlorinated hydrocarbon supply chain caused by a hurricane striking the Louisiana coast. This paper presents results and conclusions from this analysis.

  14. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    PubMed

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. PMID:26874310

  15. Biodegradation of individual and multiple chlorinated aliphatic hydrocarbons by methane-oxidizing cultures.

    PubMed Central

    Chang, H L; Alvarez-Cohen, L

    1996-01-01

    The microbial degradation of chlorinated and nonchlorinated methanes, ethanes, and ethanes by a mixed methane-oxidizing culture grown under chemostat and batch conditions is evaluated and compared with that by two pure methanotrophic strains: CAC1 (isolated from the mixed culture) and Methylosinus trichosporium OB3b. With the exception of 1,1-dichloroethylene, the transformation capacity (Tc) for each chlorinated aliphatic hydrocarbon was generally found to be in inverse proportion to its chlorine content within each aliphatic group (i.e., methanes, ethanes, and ethenes), whereas similar trends were not observed for degradation rate constants. Tc trends were similar for all methane-oxidizing cultures tested. None of the cultures were able to degrade the fully chlorinated aliphatics such as perchloroethylene and carbon tetrachloride. Of the four cultures tested, the chemostat-grown mixed culture exhibited the highest Tc for trichloroethylene, cis-1,2-dichloroethylene, tetrachloroethane, 1,1,1-trichloroethane, and 1,2-dichloroethane, whereas the pure batch-grown OB3b culture exhibited the highest Tc for all other compounds tested. The product toxicity of chlorinated aliphatic hydrocarbons in a mixture containing multiple compounds was cumulative and predictable when using parameters measured from the degradation of individual compounds. The Tc for each chlorinated aliphatic hydrocarbon in a mixture (Tcmix) and the total Tc for the mixture (sigma Tcmix) are functions of the individual Tc, the initial substrate concentration (S0), and the first-order rate constant (k/Ks) of each compound in the mixture, indicating the importance of identifying the properties and compositions of all potentially degradable compounds in a contaminant mixture. PMID:8795228

  16. Hydrothermal processing of chlorinated hydrocarbons in a titanium reactor

    SciTech Connect

    Foy, B.R.; Waldthausen, K.; Sedillo, M.A.; Buelow, S.J.

    1996-09-01

    Experiments are reported on the oxidative hydrothermal destruction of chlorinated organics in a corrosion-resistant titanium reactor. Oxidation reaction conditions were 250-500 {degree}C near 650 bar and reaction times of 30-100 s in a continuous-flow reactor. Trichloroacetic acid, trichloroethylene, and 1,1,1-trichloroethane behaved similarly. The organic concentration was approximately 1.5 wt%; hydrogen peroxide was the oxidizer; sodium bicarbonate was added to achieve neutral pH. Hydrolysis occurs at low temperature, producing chloride ion and secondary organics. Carbon dioxide is the sole carbon product at 500 {degree}C. Sodium nitrate and sodium nitrite were also found to be effective oxidizers. Corrosion of the titanium was found to be slight (<0.038 mm/yr). The reaction mixture is likely not a single phase at these conditions. The destruction efficiency for trichloroethylene was estimated as 99.96% at 450 {degree}C and 60 s, with <0.02% conversion to volatile chlorinated organic byproducts. 33 refs., 9 figs., 6 tabs.

  17. Chemical kinetic modeling of chlorinated hydrocarbons under stirred-reactor conditions

    SciTech Connect

    Pitz, W.J.; Westbrook, C.K.

    1990-10-04

    The combustin of chloroethane is modeled as a stirred reactor so that we can study critical emission characteristics of the reactor as a function of residence time. We examine important operating conditions such as pressure, temperature, and equivalence ratio and their influence on destructive efficiency of chloroethane and production of other chlorinated products. The model uses a detailed chemical kinetic mechanism that we have developed previously for C{sub 3} hydrocarbons. We have added to this mechanism the chemical kinetic mechanism for C{sub 2} chlorinated hydrocarbons developed by Senkan and coworkers. Some reactions have been added to Senkan's mechanism and some of the reaction-rate expressions have been updated to reflect recent developments in the literature. In the modeling calculations, sensitivity coefficients are determined to find which reaction-rate constants have the largest effect on destructive efficiency. 25 refs., 6 figs., 1 tab.

  18. Reduction of chlorinated hydrocarbons with natural sunlight in a platinum-catalyzed water photolysis system

    SciTech Connect

    Wang, T.C.; Tan, C.K.

    1988-08-01

    Carbon tetrachloride and trichloroethylene in a water photolysis system (Pt colloid/Ru(bipy)/sub 3//sup 2 +//MV/sup 2 +//EDTA) were reduced to methane and/or ethane during solar illumination. This paper demonstrates that solar energy can be used to excite electron-transfer reactions in the system, which results in the cleavage of water to H/sub 2/ and OH/sup -/. Data suggest chlorinated hydrocarbons added to the system can be dechlorinated and subsequently reduced to low molecular weight hydrocarbons.

  19. Radiation induced dechlorination of some chlorinated hydrocarbons in aqueous suspensions of various solid particles

    NASA Astrophysics Data System (ADS)

    Múčka, V.; Buňata, M.; Čuba, V.; Silber, R.; Juha, L.

    2015-07-01

    Radiation induced dechlorination of trichloroethylene (TCE) and tetrachloroethylene (PCE) in aqueous solutions containing the active carbon (AC) or cupric oxide (CuO) as the modifiers was studied. The obtained results were compared to the previously studied dechlorination of polychlorinated biphenyls (PCBs). Both modifiers were found to decrease the efficiency of dechlorination. The AC modifier acts mainly via adsorption of the aliphatic (unlike the aromatic) hydrocarbons and the CuO oxide mainly inhibits the mineralization of the perchloroethylene. The results presented in this paper will be also helpful for the studies of the impact of chlorinated hydrocarbons on the membrane permeability of living cells.

  20. Using trees to remediate groundwaters contaminated with chlorinated hydrocarbons. 1997 annual progress report

    SciTech Connect

    Gordon, M.P.; Newman, L.A.; Strand, S.E.

    1997-01-01

    'Metabolism of Chlorinated Hydrocarbons Laboratory and field tests with poplar in tissue culture, bioreactors, and field sites have shown that, unlike bacteria, these plants are able to carry out complete degradation of fully chlorinated alkanes and alkenes to carbon dioxide and chloride. Carbon dioxide was produced as a product of the degradation of trichloroethylene (TCE), carbon tetrachloride (CT), and perchloroethylene (PCE) when axenic tissue cultures of poplar cells were exposed to radiolabelled compounds. The apparent degradation of PCE and CT, fully chlorinated hydrocarbons, in these aerobic plants is remarkable when contrasted to the lack of comparable aerobic degradation by bacteria. Oxidized metabolites, such as trichloroethanol, and di- and trichloroacetic acid, were detected in cell cultures exposed to TCE, suggesting the involvement of cytochrome P450s or other monooxygenase activities. Mass balance experiments with small poplar plants in laboratory reactors showed that significant TCE and CT was volatilized from the leaves, while a similar fraction of radiolabeled carbon from these chlorinated solvents was retained in the plant tissue.'

  1. Enzyme-based detection of chlorinated hydrocarbons in water. Report for October 1982-July 1983

    SciTech Connect

    Offenhartz, B.H.; Lefko, J.L.

    1985-04-01

    An enzyme-based approach for detecting hazardous levels of high-molecular-weight chlorinated hydrocarbons in natural waters was explored. An extensive review of the literature indicated that the enzymes, lactate dehydrogenase, carbonic anhydrase, hexokinase, phosphorylase and an ATPase are suitable for field method development. Lactate dehydrogenase (LDH) was chosen to develop a method that promises rapid, reliable, and cost-effective detection. The LDH-catalyzed reaction is used to detect chlorinated hydrocarbons, which reduce the rate of the reaction by reversibly inhibiting the enzyme. The analysis uses pH detection and takes 5 minutes. So far, the LDH method has been used to detect aldrin, toxaphene, DDT, PCBs, pentachlorophenol and 2,4,5,-T at the parts per million level. A review of the literature suggests that most organochlorine pesticides, PCBs, polychlorinated phenols and chlorophenoxy derivatives can be detected by the LDH method. Preliminary investigations of potential interferants suggest that the LDH method selectively detects chlorinated hydrocarbons. Work was begun on immobilizing the enzyme for incorporation in water monitor and field detector designs. The LDH method shows potential for use in field devices and for processing extracts of soils and wastes, as well as water samples. These method adaptations are recommended for future work.

  2. Membrane-Extraction Ion Mobility Spectrometry for In-Situ Detection of Chlorinated Hydrocarbons in Water

    SciTech Connect

    Du, Yongzhai; Zhang, Wei; Whitten, William B; Li, Haiyang; Watson, David B; Xu, Jun

    2010-01-01

    Membrane-extraction ion mobility spectrometry (ME-IMS) has been developed for in-situ sampling and analysis of trace chlorinated hydrocarbons in water in a single procedure. The sampling is configured so that aqueous contaminants permeate through a spiral hollow polydimethylsiloxane (PDMS) membrane and are carried away by a vapor flow through the membrane tube. The extracted analyte flows into an atmospheric pressure chemical ionization (APCI) chamber and is analyzed in a home-made IMS analyzer. PDMS membrane is found to effectively extract chlorinated hydrocarbon solvents from liquid phase to vapor. The specialized IMS analyzer has been found to have resolutions of R=33 and 41, respectively, for negative- and positive-modes and is capable of detecting aqueous tetrachloroethylene (PCE) and trichloroethylene (TCE) as low as 80 g/L and 74 g/L in negative ion mode, respectively. The time-dependent characteristics of sampling and detection of TCE are both experimentally and theoretically studied for various concentrations, membrane lengths, and flow rates. These characteristics demonstrate that membrane-extraction IMS is feasible for the continuous monitoring of chlorinated hydrocarbons in water.

  3. Chlorinated hydrocarbon and mercury residues in woodcock in the United States, 1970-71

    USGS Publications Warehouse

    Clark, D.R., Jr.; McLane, M.A.R.

    1974-01-01

    During Late 1970 and early 1971, 229 woodcock (Philohela minor) were collected from 23 Eastern and Midwestern States. Analyses for chlorinated hydrocarbons and mercury in these migratory birds showed generally low levels which are not considered dangerous to human consumers. In this survey, Louisiana woodcock had lower residues of heptachlor epoxide and DDE than those tested in a 1965 survey. PCB levels, however, may have increased. Mirex levels were greatest in Mississipi and Louisiana woodcock. Pooling of birds and averaging of individually analyzed birds did not provide equivalent estimates of equivalent residues; pool values tended to be larger and more variable. Levels of six chlorinated hydrocarbons and mercury were negatively correlated with the latitude of the collection site. However, this relationship seemed weakest for PCB's. Among eight chemical residues, PCB levels were most often correlated with levels of the other seven. Levels of chlorinated hydrocarbons in wings were correlated with levels in breast muscle and in carcass; however, mean levels of certain residues differed significantly among wing, muscle, and carcass even when compared on a lipid basis.

  4. Natural attenuation of chlorinated hydrocarbons in a freshwater wetland

    USGS Publications Warehouse

    Lora, Michelle M.; Olsen, Lisa D.; Smith, Barrett L.

    1997-01-01

    Natural attenuation of chlorinated volatile organic compounds (VOC's) occurs as ground water discharges from a sand aquifer to a freshwater wetland at Aberdeen Proving Ground, Md. Field and laboratory results indicate that biotransformation in the anaerobic wetland sediments is an important attenuation process. Relatively high concentrations of the parent compounds trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (PCA) and low or undetectable concentrations of daughter products were measured in the aquifer. In contrast, relatively high concentrations of the daughter products cis- and trans-1,2-dichloroethylene (12DCE); vinyl chloride (VC); 1,1,2-trichloroethane (112TCA); and 1,2-dichloroethane (12DCA) were measured in ground water in the wetland sediments, although total VOC concentrations decreased upward from about 1 mu mol/L (micromoles per liter) at the base of the wetland sediments to less than 0.2 near the surface. Microcosm experiments showed that 12DCE and VC are produced from anaerobic degradation of both TCE and PCA; PCA degradation also produced 112TCA and 12DCA.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  6. Chlorine-hydrocarbon photochemistry in the marine troposphere and lower stratosphere

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Kasting, J. F.

    1988-01-01

    The role of chlorine atoms in the oxidation of methane and nonmethane hydrocarbons (NMHCs) in the marine troposphere and lower stratosphere was investigated using a one-dimensional photochemical model that incorporated the chemistry of CH4, NMHCs, NO(x), O(x), and HO(x), as well as organic and inorganic halogens in the troposphere and lower stratosphere. The model predicted that chlorine atoms are present in the marine troposphere at the concentrations of about 1000/cu cm, mostly as a product of the reaction between OH and HCl released from sea spray. The results indicate that Cl atoms cause 20 to 40 percent of NMHC oxidation in the troposphere and 40 to 90 percent in the lower stratosphere. At 15 km, the NMHC-Cl reactions account for nearly 80 percent of the PAN produced. Where available, experimental data confirmed the model predictions.

  7. Natural attenuation of chlorinated solvents, petroleum hydrocarbons, and other organic compounds

    SciTech Connect

    Alleman, B.C.; Leeson, A.

    1999-11-01

    The natural attenuation option is getting more attention from site managers and regulators as a viable alternative to more costly engineered site remediation approaches. Natural attenuation was first demonstrated at sites with hydrocarbon contamination, but recent studies at sites contaminated by chlorinated compounds have shown that this approach often has merit for these more challenging contamination problems. Covering natural attenuation in media ranging from deep aquifers to shallow soils, and for contaminants ranging from fuels to solvents to herbicides, this volume offers the reader a comprehensive overview of case studies that represent the current state of the art in natural attenuation approaches to site remediation.

  8. Effect of reduced iron on the degradation of chlorinated hydrocarbons in contaminated soil and ground water: A review of publications

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.

    2014-02-01

    Chlorinated hydrocarbons are among the most hazardous organic pollutants. The traditional remediation technologies, i.e., pumping of contaminated soil- and groundwater and its purification appear to be costly and not very efficient as applied to these pollutants. In the last years, a cheaper method of destroying chlorine-replaced hydrocarbons has been used based on the construction of an artificial permeable barrier, where the process develops with the participation of in situ bacteria activated by zerovalent iron. The forced significant decrease in the redox potential (Eh) down to -750 mV provides the concentration of electrons necessary for the reduction of chlorinated hydrocarbons. A rise in the pH drastically accelerates the dechlorination process. In addition to chlorine-organic compounds, ground water is often contaminated with heavy metals. The influence of the latter on the effect of zerovalent iron may be different: both accelerating its degradation (Cu) and inhibiting it (Cr). Most of the products of zerovalent iron corrosion, i.e., green rust, magnetite, ferrihydrite, hematite, and goethite, weaken the efficiency of the Fe0 barrier by mitigating the dechlorination and complicating the water filtration. However, pyrrhotite FeS, on the contrary, accelerates the dechlorination of chlorine hydrocarbons.

  9. Transport Modeling of Membrane Extraction of Chlorinated Hydrocarbon from Water for Ion Mobility Spectrometry

    SciTech Connect

    Zhang, Wei; Du, Yongzhai; Feng, Zhili; Xu, Jun

    2010-01-01

    Membrane-extraction Ion Mobility Spectrometry (ME-IMS) is a feasible technique for the continuous monitoring of chlorinated hydrocarbons in water. This work studies theoretically the time-dependent characteristics of sampling and detection of trichloroethylene (TCE). The sampling is configured so that aqueous contaminants permeate through a hollow polydimethylsiloxane (PDMS) membrane and are carried away by a transport gas flowing through the membrane tube into IMS analyzer. The theoretical study is based on a two-dimensional transient fluid flow and mass transport model. The model describes the TCE mixing in the water, permeation through the membrane layer, and convective diffusion in the air flow inside membrane tube. The effect of various transport gas flow rates on temporal profiles of IMS signal intensity is investigated. The results show that fast time response and high transport yield can be achieved for ME-IMS by controlling the flow rate in the extraction membrane tube. These modeled time-response profiles are important for determining duty cycles of field-deployable sensors for monitoring chlorinated hydrocarbons in water.

  10. Determination of Chlorinated Hydrocarbons in Water Using Highly Sensitive Mid-Infrared Sensor Technology

    PubMed Central

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

    2013-01-01

    Chlorinated aliphatic hydrocarbons and chlorinated aromatic hydrocarbons (CHCs) are toxic and carcinogenic contaminants commonly found in environmental samples, and efficient online detection of these contaminants is still challenging at the present stage. Here, we report an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor for in-situ and simultaneous detection of multiple CHCs, including monochlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, trichloroethylene, perchloroethylene, and chloroform. The polycrystalline silver halide sensor fiber had a unique integrated planar-cylindric geometry, and was coated with an ethylene/propylene copolymer membrane to act as a solid phase extractor, which greatly amplified the analytical signal and contributed to a higher detection sensitivity compared to the previously reported sensors. This system exhibited a high detection sensitivity towards the CHCs mixture at a wide concentration range of 5~700 ppb. The FTIR-ATR sensor described in this study has a high potential to be utilized as a trace-sensitive on-line device for water contamination monitoring. PMID:23982222

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  12. In situ bioremediation of petroleum hydrocarbons and chlorinated hydrocarbons: Three case studies

    SciTech Connect

    Bost, R.C.; Perry, R.G.; Barber, T.

    1997-06-01

    In situ biodegradation of organic contaminants is one of the most cost-effective means of site remediation. This method has proven successful in soils, ground water, and slurries. Bacteria capable of degrading organic contaminants within an aquifer include many species from a wide spectrum of genera, e.g. Pseudomonas, Corynebacterium, Bacillus, etc. In most cases, a mixture of bacterial strains is required to completely oxidize a complex organic contaminant. Each strain of an organism may target a specific compound, working together with other organisms to ultimately degrade each intermediate until complete degradation, also known as mineralization, occurs. One or more of the following mechanisms are utilized by bacteria for organic chemical degradation: (1) aerobic, (2) anaerobic, and (3) co-metabolic. During aerobic oxidation of organic chemicals, bacteria utilize the pollutant as an electron and hydrogen source and oxygen acts as the electron and hydrogen acceptor, resulting in water. As the bacterial enzymes cleave the compound, oxidized products are produced along with energy for the reaction to proceed. This is the most rapid and widely utilized mechanism. Dehalogenation occurs under aerobic, or perhaps more often, under anoxic conditions. This process occurs in the presence of alternate electron acceptors and replaces chlorine with hydrogen. The mechanism of co-metabolism can be aerobic or anaerobic, but is more often aerobic. This process requires a separate energy source for the bacterial cell because the pollutant is not utilized as an energy source. The role of bioremediation in site remediation is demonstrated below by three case studies: (1) a refinery, (2) a municipal landfill and (3) a pesticide formulation plant.

  13. MONITORING THE SUCCESS OF SEDIMENT REMEDIATION AT A SITE CONTAMINATED WITH CHLORINATED PESTICIDES, POLYNUCLEAR AROMATIC HYDROCARBONS AND ARSENIC

    EPA Science Inventory

    Monitoring the Success of Sediment Remediation at a Site Contaminated with Chlorinated Pesticides, Polynuclear Aromatic Hydrocarbons and Arsenic (Baird & McGuire Superfund Site, Holbrook, MA) Contaminated sediment in the Cochato River adjacent to the Baird & McGuire Superfund Sit...

  14. PERMEABLE REACTIVE SUBSURFACE BARRIERS FOR THE INTERCEPTION AND REMEDIATION OF CHLORINATED HYDROCARBON AND CHROMIUM (VI) PLUMES IN GROUND WATER

    EPA Science Inventory

    This document concerns the use of permeable reactive subsurface barriers for the remediation of plumes of chlorinated hydrocarbons and Cr(VI) species in ground water, using zero-valent iron (Fe0) as the reactive substrate. Such systems have undergone thorough laboratory research,...

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

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.; Cabane, Michel; Coll, Patrice; Conrad, Pamela G.; Coscia, David; Dworkin, Jason P.; Franz, Heather B.; Grotzinger, John P.; Leshin, Laurie A.; Martin, Mildred G.; McKay, Christopher; Ming, Douglas W.; Navarro-Gonzalez, Rafael; Pavlov, Alexander; Steele, Andrew; Summons, Roger E.; Szopa, Cyril; Teinturier, Samuel; Mahaffy, Paul R.

    2013-01-01

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

  16. Evidence for perchlorates and the origin of chlorinated hydrocarbons detected by SAM at the Rocknest aeolian deposit in Gale Crater

    NASA Astrophysics Data System (ADS)

    Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas; Atreya, Sushil K.; Brinckerhoff, William B.; Cabane, Michel; Coll, Patrice; Conrad, Pamela G.; Coscia, David; Dworkin, Jason P.; Franz, Heather B.; Grotzinger, John P.; Leshin, Laurie A.; Martin, Mildred G.; McKay, Christopher; Ming, Douglas W.; Navarro-González, Rafael; Pavlov, Alexander; Steele, Andrew; Summons, Roger E.; Szopa, Cyril; Teinturier, Samuel; Mahaffy, Paul R.

    2013-10-01

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

  17. Role of plant biomass in the global environmental partitioning of chlorinated hydrocarbons

    SciTech Connect

    Calamari, D.; Morosini, M.; Vighi, M. ); Bacci, E.; Focardi, S.; Gaggi, C. )

    1991-08-01

    Plant biomass plays a significant role in the global environmental partitioning phenomena and plants are good indicators of tropospheric contamination levels by chlorinated hydrocarbons. In the present research 300 samples of plants were collected in 265 areas distributed worldwide and analyzed for HCB (hexachlorobenzene), {alpha}-HCH (hexachlorocyclohexane), {gamma}-HCH, p,p{prime}-DDT,o,p{prime}-DDT, and p,p{prime}-DDE (degradation product of DDT). Global HCB distribution is strongly dependent on the temperature, the HCB being present mainly in samples from cold areas. The sum of DDTs show higher concentrations in samples from topical areas, while the sum of HCHs is higher in the plants from the Northern Hemisphere. These results are discussed, taking into account the role of physicochemical properties in determining the global distribution as well as the air age of the contamination.

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

    SciTech Connect

    Strand, Stuart E.

    2002-06-01

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

  19. Using trees to remediate groundwaters contaminated with chlorinated hydrocarbons. 1998 annual progress report

    SciTech Connect

    Strand, S.E.; Gordon, M.P.

    1998-06-01

    'Industrial practices in the past have resulted in contamination of groundwater with chlorinated hydrocarbons (CHCs) at many DOE sites, such as Hanford and Savannah River. Such contamination is a major problem because existing groundwater remediation technologies are expensive and difficult. An inexpensive method for groundwater remediation is greatly needed. Trees could be used to remediate CHC polluted groundwater at minimal cost (phytoremediation). Before phytoremediation can be extensively applied, the authors must determine the range of compounds that are attacked, the effects of metabolic products on the plants and the environment, and the effect of transpiration and concentration of CHC on uptake and metabolism. They will test the ability of hybrid poplar to take up and transform the chlorinated methanes, ethanes and ethylenes. The rate of uptake and transformation by poplar of TCE as a function of concentration in the soil, transpiration rate and illumination level will be determined. Methods will be developed to permit rapid testing of plants from contaminated sites for species able to oxidize and sequester chlorinated compounds. They will identify the nature of the bound residues of TCE metabolism in poplar. They will identify the mechanisms involved in CHC oxidation in poplar and use genetic manipulations to enhance that activity. They will introduce the genes for mammalian cytochrome P-450-IIE1, known to oxidize light CHCs such as TCE to attempt to increase the CHC metabolism capacity of poplar. The results of this research will place phytoremediation of CHCs on a firm scientific footing, allowing a rational assessment of its application to groundwater contamination. This report summarizes the results of the first 1.5 years of work on a three-year project.'

  20. Chlorine

    Integrated Risk Information System (IRIS)

    Chlorine ; CASRN 7782 - 50 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  1. Chlorine

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

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

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

    PubMed

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

    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) microg/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) microg/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. PMID:22783624

  3. Anaerobic biotransformation of chlorinated aliphatic hydrocarbons: Ugly duckling to beautiful swan

    SciTech Connect

    Parkin, G.F.

    1999-10-01

    For many years anaerobic biological processes were reputed to be more sensitive than aerobic processes to toxic substances such as chlorinated aliphatic hydrocarbons (CAH) and thus a poor choice for treating water containing these compounds. This was especially true for water containing perchloroethylene (PCE) or trichloroethylene (TCE) because vinyl chloride, a human carcinogen, is produced when these two compounds are degraded anaerobically. Aerobic treatment with organisms containing oxygenase enzyme systems, which could fortuitously degrade a wide variety of chlorinated aliphatics (but not PCE), was favored. Recently, however, several enrichments and organisms have been isolated that will convert PCE and TCE into ethene and ethane, as shown by field data. Because of this evidence, anaerobic processes are now considered a significant alternative treatment for CAH contamination. Recent work at the University of Iowa, Iowa City, has focused on the effect of mixtures of CAHs on biotransformation of individual organic compounds and the potential for a combined methanogen-iron (Fe(0)) system to improve CAH bioremediation. At the concentration ranges tested, the presence of a mixture of CAHs seems to decrease rate of transformation of individual organics. However, there are important exceptions; in some cases a mixture of CAHs seems to facilitate transformation of an individual organic compound. Combination of an active methanogenic population with Fe(0) increases the rate and extent of transformation of carbon tetrachloride and chloroform. Results with PCE and 1,1,1-trichloroethane are less clear.

  4. Comparative bioaccumulation of chlorinated hydrocarbons from sediment by two infaunal invertebrates

    SciTech Connect

    Meador, J.P.; Adams, N.G.; Casillas, E.; Bolton, J.L.

    1995-12-31

    Bioaccumulation of chlorinated hydrocarbons (CHs) from field-contaminated sediments by two infaunal invertebrates, Rhepoxynius abronius and Armandia brevis was examined in the laboratory. Sediments were selected over a large geographical area of an urban estuary, the Hudson-Raritan, to assess the potential for bioaccumulation. Amphipod and polychaete tissue burdens were highly correlated over sites; however, concentrations of the trichlorobiphenyls in the polychaete were about twice that found in the amphipod and 4 to 8 times higher for the more hydrophobic PCBs. Unlike PAHs from these sediments, concentrations of CHs in IW and sediment indicated that partition coefficients (K{sub oc}) were generally as predicted. K{sub oc} values determined with non-sorbed interstitial water concentrations (IW{sub free}) were much closer to predicted values compared to those based on the total chlorinated compound. As expected, BAF values were highly variable among sites and increased greatly with declining TOC content. The BAF{sub loc} (lipid/organic carbon normalized bioaccumulation factor) for trichlorobiphenyls in the polychaete was similar to that for the amphipod; however the polychaete BAF{sub loc} increased with increasing hydrophobicity and was maximum for the pentachlorobiphenyls and close to the expected maximum. Some evidence for site-specific BAF{sub loc} values was found because of a strong correlation between BAF{sub loc} and sediment concentration; however for some PCBs, this correlation was weak.

  5. Relative induction of a biomarker, P450 RGS, by PAHs and chlorinated hydrocarbons

    SciTech Connect

    Bothner, K.; Anderson, J. |

    1995-12-31

    A reporter gene system (RGS) assay has been engineered from a human liver cancer cell fine so that the induction of CPA gene will result in the production of luciferase (firefly plasmid) instead of cytochrome P450. Induction of this test system by compounds such as polycyclic aromatic hydrocarbons (PAHs) and chlorinated hydrocarbons infers these xenobiotics are present at levels that are potentially toxic, carcinogenic, or mutagenic to organisms. Six well plates with 1.0 {times} 10{sup 6} adhered cells in 2 mLs of media are inoculated with varying volumes of organic solvents containing a reference toxicant (TCDD) and sample extracts. Solvent extracts (EPA 3540) of aquatic sediments, soils, and mussel tissue have been applied directly to this system. Test results show a significant RGS induction from concentrations of PAHs, that if present in a 40 gram sediment sample, would be (in ng/g or ppb): 20 for dibenz(a,h)anthracene; 70 for benz(a)anthracene; 100 for benzo(a)pyrene; and 250 for chrysene. Testing with mixtures of PAHs and environmental samples has shown that levels of 300 to 400 ppb are detected. Results to be presented from P450 RGS testing will show that the estimated health risk (Toxic Equivalent Factors, TEFs) of some of the PAHs may be as great or greater than some of the coplanar PCB.

  6. Chlorine

    SciTech Connect

    Talmage, Sylvia Smith

    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

  7. The effect of fuel and chlorinated hydrocarbons on a vapor phase carbon adsorption system

    SciTech Connect

    Crawford, W.J.; Cheney, J.L.; Taggart, D.B.

    1995-12-31

    A soil vapor extraction (SVE) system installed at the South Tacoma Well 12A Superfund Site was designed to recover 1,2-dichloroethylene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,2,2-tetrachloroethane (1,1,2,2-TCA) from the vadose zone. The basic system consisted of twenty-two extraction wells, three centrifugal blowers, and three carbon adsorbers. The carbon adsorbers were regenerated on site by steam stripping. The mixture of steam and stripped organics was condensed and then decanted to separate the water from the organic phase. The recovered water was air stripped to remove the dissolved organics prior to discharge to the city storm sewer. The recovered organic phase was then shipped off site for thermal destruction. Previous reports described operating difficulties with the decanter, and air strippers. Sampling and analyses were performed which identified the problem as the simultaneous recovery of unexpected fuel hydrocarbons in addition to the solvents. Recovery of fuels resulted in a light phase in the decanter in addition to the water and heavy solvent phases. This required redesign of the decanter to handle the third phase. The effectiveness of desorption of the carbon beds by steam stripping gradually decreased as the remediation progressed into the second year of operation. Samples were collected from the carbon beds to evaluate the effect of the fuel and chlorinated hydrocarbons on the activated carbon. This report describes the results of these analyses. The data indicated that both 1,1,2,2-TCA and fuel hydrocarbons in the C-9 to C-24 range remained in the carbon beds after steam regeneration in sufficient quantities to require replacing the carbon.

  8. Diurnal variability of chlorinated polycyclic aromatic hydrocarbons in urban air, Japan

    NASA Astrophysics Data System (ADS)

    Ohura, Takeshi; Horii, Yuichi; Kojima, Mitsuhiro; Kamiya, Yuta

    2013-12-01

    Concentrations of 3- to 5-ring chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and corresponding PAHs were quantified in 3-h integrated air samples, taken serially over 3-day periods in December 2009 (winter) and August 2010 (summer) in the urban area of Shizuoka, Japan. Twenty species of targeted ClPAHs were detected in both gas and particle phases throughout each campaign. Mean concentrations of total ClPAHs in the winter and summer campaigns were 133 ± 53 pg m-3 and 32 ± 27 pg m-3, respectively. Throughout the campaigns, diurnal variations of total ClPAHs concentrations did not have periodic fluctuation such as decreasing in daytime and increasing in nighttime, observed in PAHs. However, the mean concentrations of particulate ClPAHs trended to be slightly higher in nighttime than in daytime, but not for gaseous ClPAHs. Significant correlations were observed between the concentrations of total ClPAHs and total PAHs in particulate phase, but not in gaseous phase. In addition, for particulate phase, there were significant correlations between the concentrations of individual ClPAHs and corresponding parent PAHs, nitrate, and chlorine in summer, but not in winter. Considering these behaviors of ClPAHs in the air, the emission sources could have features of as follows: (i) specific emission sources emitted both ClPAHs and PAHs in particulate phase could be present in the area; (ii) particulate ClPAHs could be more strongly influenced by local sources and photochemical reactions rather than by transboundary air pollution; (iii) the possible sources could be combustion processes included biomass and fossil fuels.

  9. An assessment of natural biotransformation of petroleum hydrocarbons and chlorinated solvents at an aquifer plume transect.

    PubMed

    Skubal, K L; Barcelona, M J; Adriaens, P

    2001-05-01

    Field biogeochemical characterization and laboratory microcosm studies were performed to assess the potential for future biotransformation of trichloroethylene (TCE) and toluene in a plume containing petroleum hydrocarbons and chlorinated solvents at the former Wurtsmith Air Force Base in Oscoda, MI. In situ terminal electron accepting processes (TEAPs), contaminant composition and microbial phylogeny were studied at a plume transect 100 m downgradient of the source. The presence of reduced electron acceptors, relevant microbial communities, and elevated dissolved methane and carbon dioxide concentrations at the transect, as well as downgradient accumulation of BTEX metabolites and dechlorination products, indicated that past or current reductive dechlorination at the transect was likely driven by BTEX biodegradation in the methanogenic zone. However, TCE and toluene mineralization in sediment-groundwater microcosms without added electron acceptors did not exceed 5% during 300 days of incubation and was nearly invariant with original sediment TEAP, even following amendments of nitrogen and phosphorus. Mineralization rates were on the order of 0.0015-0.03 mumol/g day. After 8 months, microcosms showed evidence of methanogenesis, but CH4 and CO2 production arose from the degradation of contaminants other than toluene. Cis-dichloroethylene was observed in only one methanogenic microcosm after more than 500 days. It appears likely that spatially and temporally dynamic redox zonation at the plume transect will prevent future sustained reductive dehalogenation of highly chlorinated solvents, for during the course of a year, the predominant TEAP at the highly contaminated water table shifted from methanogenesis to iron- and sulfate-reduction. It is recommended that biotransformation studies combine considerations of long-term, spatially relevant changes in redox zonation with laboratory-scale studies of electron donor utilization and cometabolic substrate transformation

  10. Flux of transuranium nuclides and chlorinated hydrocarbons in the northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Fowler, S. W.; Ballestra, S.; Villeneuve, J.-P.

    1990-09-01

    The transuranium nuclides, plutonium and americium, and selected chlorinated hydrocarbon compounds have been measured in sediment trap samples, bottom sediments and waters. These measurements have been used to quantify vertical fluxes and elucidate particulate biogeochemical cycles, of these man-made contaminants in the northwestern Mediterranean. Sediment trap experiments in the Gulf of Lions (Lacaze-Duthiers Canyon) have shown that transuranic fluxes are considerably higher in the Gulf of Lions, than those which have been reported for the northeast Pacific; principally this is due to the relatively high mass fluxes in this region of the Mediterranean. Water, surface sediment and sediment trap data indicate that 241Am is being transported downward (via particle settling) more rapidly than 239+240Pu. From direct flux measurement, residence times for 239+240Pu and 241Am in the upper 300 m were computed to be 2.5 and 0.14 years, respectively. Comparison of 239+240Pu concentrations in the water column, in 1986, with similar measurements made 5-11 years earlier suggests that fallout input to the Mediterranean has decreased by nearly a factor of 2 during the period 1975-1986. Fluxes of PCB, HCB, γ-HCH and DDT residues varied by as much as an order of magnitude, or more, both temporally and with depth. The average fluxes of most of the compounds in the Lacaze-Duthiers Canyon, during 1985-1986, were quite similar to those measured off the coast of Monaco several years earlier. Generally, the increased chlorinated hydrocarbon fluxes observed with depth were a direct result of the much higher mass fluxes which occurred at depth. Demonstrated differences in PCB concentrations in the settling particles, deposited surface sediments and overlying sediment floc indicate that simple bottom sediment resuspension is not a major contributor to the enhanced PCB flux noted at depth. The PCB concentration in sedimenting particulate material collected from deeper waters, is similar to

  11. INTERNATIONAL STUDY OF 'ARTEMIA' VIII. COMPARISON OF THE CHLORINATED HYDROCARBONS AND HEAVY METALS IN FIVE DIFFERENT STRAINS OF NEWLY HATCHED 'ARTEMIA' AND A LABORATORY-REARED MARINE FISH

    EPA Science Inventory

    Newly hatched nauplii of Artemia from Brazil, Australia, Italy, and the United States (Utah and San Pablo Bay, California) were analyzed for chlorinated hydrocarbons. The Brazil and Australia nauplii contained very low levels of PCB and chlorinated insecticides. Italian nauplii c...

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

    USGS Publications Warehouse

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

    1998-01-01

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

  13. Kinetics of chlorinated hydrocarbon degradation by Methylosinus trichosporium OB3b and toxicity of trichloroethylene.

    PubMed Central

    Oldenhuis, R; Oedzes, J Y; van der Waarde, J J; Janssen, D B

    1991-01-01

    The kinetics of the degradation of trichloroethylene (TCE) and seven other chlorinated aliphatic hydrocarbons by Methylosinus trichosporium OB3b were studied. All experiments were performed with cells grown under copper stress and thus expressing soluble methane monooxygenase. Compounds that were readily degraded included chloroform, trans-1,2-dichloroethylene, and TCE, with Vmax values of 550, 330, and 290 nmol min-1 mg of cells-1, respectively. 1,1-Dichloroethylene was a very poor substrate. TCE was found to be toxic for the cells, and this phenomenon was studied in detail. Addition of activated carbon decreased the acute toxicity of high levels of TCE by adsorption, and slow desorption enabled the cells to partially degrade TCE. TCE was also toxic by inactivating the cells during its conversion. The degree of inactivation was proportional to the amount of TCE degraded; maximum degradation occurred at a concentration of 2 mumol of TCE mg of cells-1. During conversion of [14C]TCE, various proteins became radiolabeled, including the alpha-subunit of the hydroxylase component of soluble methane monooxygenase. This indicated that TCE-mediated inactivation of cells was caused by nonspecific covalent binding of degradation products to cellular proteins. Images PMID:2036023

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

    SciTech Connect

    Brigmon, R.L.; Franck, M.M.; Brey, J.; Fliermans, C.B.; Scott, D.; Lanclos, K.

    1997-06-01

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

  15. Structural and dynamical properties of chlorinated hydrocarbons studied with resonant inelastic x-ray scattering.

    PubMed

    Bohinc, R; Žitnik, M; Bučar, K; Kavčič, M; Carniato, S; Journel, L; Guillemin, R; Marchenko, T; Kawerk, E; Simon, M; Cao, W

    2016-04-01

    We present a theoretical and experimental study of resonant inelastic x-ray scattering on a large group of chlorinated hydrocarbons: CH3Cl, CH2Cl2, CHCl3, CCl4, CH3CH2Cl, ClCH2CH2Cl, CH3CHCl2, CH3CCl3, C2H2Cl2-iso, C2H2Cl2-cis, C2H2Cl2-trans, and C6H5Cl. Differences in structural and dynamical properties of the molecules generated by diverse chemical environments are observed in the measured Cl(Kα) spectral maps as well as in the Cl(K) total fluorescence yield spectra. The energy position, relative intensity, and the width of the Franck-Condon distribution of low-lying σ(∗) and π(∗) resonances are extracted by a fitting procedure taking into account the experimental broadening. The theoretical values obtained with the transition potential and Δ Kohn-Sham methods are in good agreement with the experimental parameters indicating subtle differences due to variations in the molecular structure. PMID:27059572

  16. Structural and dynamical properties of chlorinated hydrocarbons studied with resonant inelastic x-ray scattering

    NASA Astrophysics Data System (ADS)

    Bohinc, R.; Žitnik, M.; Bučar, K.; Kavčič, M.; Carniato, S.; Journel, L.; Guillemin, R.; Marchenko, T.; Kawerk, E.; Simon, M.; Cao, W.

    2016-04-01

    We present a theoretical and experimental study of resonant inelastic x-ray scattering on a large group of chlorinated hydrocarbons: CH3Cl, CH2Cl2, CHCl3, CCl4, CH3CH2Cl, ClCH2CH2Cl, CH3CHCl2, CH3CCl3, C2H2Cl2-iso, C2H2Cl2-cis, C2H2Cl2-trans, and C6H5Cl. Differences in structural and dynamical properties of the molecules generated by diverse chemical environments are observed in the measured Cl(Kα) spectral maps as well as in the Cl(K) total fluorescence yield spectra. The energy position, relative intensity, and the width of the Franck-Condon distribution of low-lying σ∗ and π∗ resonances are extracted by a fitting procedure taking into account the experimental broadening. The theoretical values obtained with the transition potential and Δ Kohn-Sham methods are in good agreement with the experimental parameters indicating subtle differences due to variations in the molecular structure.

  17. Contamination of stream fishes with chlorinated hydrocarbons from eggs of Great Lakes salmon

    SciTech Connect

    Merna, J.W.

    1986-01-01

    Pacific salmon Oncorhynchus spp. have been stocked in the Great Lakes where they accumulate body burdens of chlorinated hydrocarbons. The transport of these contaminants to resident communities in spawning streams was studied in two tributaries of Lake Michigan accessible to anadromous spawners and one control tributary blocked to them. No polychlorinated biphenyls (PCBs), DDT, or dieldrin were detected in the sediments or biota of the control stream, or in sediments of the test streams. However, trout Salmo spp. and, to a lesser extent, sculpins Cottus spp. accumulated PCBs and DDT as a result of eating contaminated salmon eggs. Eggs constituted as much as 87% (by weight) of the total stomach contents of trout collected during the salmon spawning season early October to early January. Salmon eggs contained 0.46-9.50 mg PCBs/kg,. and 0.14-1.80 mg DDT/kg. Consumption of eggs varied greatly among individual trout, and there was a strong correlation between numbers of eggs in the stomachs and PCB and DDT concentrations in the fillets.

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

    SciTech Connect

    Stuart Strand

    2004-09-27

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

  19. Strain construction strategies for chlorinated aromatic hydrocarbon-utilizers by multiple chemostat

    SciTech Connect

    Huang, C.M.

    1988-01-01

    A multiple chemostat method was used for the construction of a recombinant bacterium having the ability to degrade chlorinated aromatic hydrocarbons (CAH). This method permits natural genetic exchange between two parental strains and subsequent selection of a novel catabolic genotype in a defined system. Many recombinants which could utilize chlorobenzene (CB) as a sole source of carbon were constructed from several separate experiments in less than one month. Reproducibility is related to several important factors such as dilution rate, growth substrate, and surface attachment. A recombinant strain, Acinetobacter sp. CB15, which could grown on 3-chlorobiphenyl (PCB congener) with the release of inorganic chloride, was constructed by the application of the multiple chemostat method. This represents the first report of a pure culture able to grow on 3-chlorobiphenyl with the release of inorganic chloride. Two metabolites produced by Acinetobacter sp. CB15 grown on 3-chlorobiphenyl were identified as 3-chlorobenzoic acid and 3-chlorocatechol. An unidentified, dead-end, black metabolite with a UV absorption maximum at 255 nm was also produced. Recombinant strain CB15 could also cometabolize, 3,3{prime}-dichlorobiphenyl with the release of inorganic chloride when it was grown on biphenyl as the growth substrate.

  20. Chlorinated hydrocarbon residues in Baikal seal (Phoca sibirica) from Lake Baikal: Levels, patterns, and metabolism

    SciTech Connect

    Nakata, H.; Tanabe, S.; Tatsukawa, R.; Amano, M.; Miyazaki, N.; Petrov, A.

    1995-12-31

    Contamination of chlorinated hydrocarbons such as DDTs (DDT and its metabolites), PCBs (polychlorinated biphenyls), CHLs (chlordane compounds) and HCHs (hexachlorocyclohexanes) was assessed in the blubber of Baikal seal (Phoca sibirica) and their fish diet collected from Lake Baikal in 1992. Higher concentrations of DDTs and PCBs were detected, ranging from 4.9 to 160 {micro}g/g and 3.5 to 64 {micro}g/g on a lipid weight basis, respectively, whereas levels of CHLs and HCHs were approximately one or three orders of magnitude lower than those of DDTs and PCBs. The average of DDTs concentrations in adult male Baikal seals were about an order of magnitude higher than those reported for seals in the North Sea around UK and comparable to grey seal in the Baltic Sea, indicating that Baikal seals are categorized in a highly contaminated group. A positive age dependent accumulation of DDTs, PCBs and CHLs was found in male, while a steady-state was observed in female which attributes to the reproductive transfer, mainly lactation, of these chemicals. On the basis of contaminant burdens in adult seals, it was estimated that adult females transfer about 19% and 14% of their DDT and PCB body burdens to their pups during a reproductive process. Based on the data from isomer specific analysis of PCBs, it can be suggested that Baikal seals have higher capacity to metabolize congeners with vicinal H-atoms in meta, para positions than those of marine mammals.

  1. Gas- and Particle-Phase Products from the Chlorine-Initiated Oxidation of Polycyclic Aromatic Hydrocarbons.

    PubMed

    Riva, Matthieu; Healy, Robert M; Flaud, Pierre-Marie; Perraudin, Emilie; Wenger, John C; Villenave, Eric

    2015-11-12

    The chlorine atom (Cl)-initiated oxidation of three polycyclic aromatic hydrocarbons (PAHs; namely, naphthalene, acenaphthylene, and acenaphthene) was investigated. Experiments were performed in an atmospheric simulation chamber using a proton transfer reaction time-of-flight mass spectrometer (TOF-MS) and an aerosol TOF-MS to characterize the oxidation products in the gas and particle phases, respectively. The major products identified from the reaction of Cl atoms with naphthalene were phthalic anhydride and chloronaphthalene, indicating that H atom abstraction and Cl addition reaction pathways are both important. Acenaphthenone was the principal product arising from reaction of Cl with acenaphthene, while 1,8-naphthalic anhydride, acenaphthenone, acenaphthenequinone, and chloroacenaphthenone were all identified as products of acenaphthylene oxidation, confirming that the cylcopenta-fused ring controls the reactivity of these PAHs toward Cl atoms. Possible reaction mechanisms are proposed for the formation of these products, and favored pathways have been suggested. Large yields of secondary organic aerosol (SOA) were also observed in all experiments, and the major products were found to undergo significant partitioning to the particle-phase. This work suggests that Cl-initiated oxidation could play an important role in SOA formation from PAHs under specific atmospheric conditions where the Cl atom concentration is high, such as the marine boundary layer. PMID:26472257

  2. Investigations of the interaction of Spartina alterniflora loisel. and the chlorinated hydrocarbons, the polychlorinated biphenyls

    SciTech Connect

    Mrozek, E. Jr.

    1981-01-01

    Polychlorinated biphenyls (PCB's) are a class of industrial chlorinated hydrocarbons which are toxic to a broad range of organisms, persistent in the environment, and tend to accumulate in estuaries, where they are available to organisms at all trophic levels. Greenhouse and laboratory studies were initiated to characterize the interaction of Spartina alterniflora Loisel, and the PCB's. Particular areas addressed were: (1) uptake, translocation, and accumulation, (2) selectivity of uptake, (3) effects of uptake and/or exposure of PCB's on S. alterniflora growth, and (4) potential for transfer of PCB's from S. alterniflora and marsh substrate to Uca pugnax (fiddler crab). In a greenhouse study it was concluded that S. alterniflora has the capacity to take up, translocate and accumulate /sup 14/C-radioactivity from sand and marsh mud originally treated with /sup 14/C-PCB's. Fiddler crabs (U. pugnax) were exposed to /sup 14/C-PCB's applied to marsh substrate or S. alterniflora plant material which had been grown in the presence of /sup 14/C-PCB's to determine if marsh substrate-to-organism and plant-to-organism PCB transfer was possible. Results indicate that transfer from both sources occurred but that accumulation of /sup 14/C-radioactivity was only observed with crabs exposed to /sup 14/C-PCB treated substrate.

  3. Variations of volatile chlorinated hydrocarbons in ambient air at industrial areas in Niigata

    SciTech Connect

    Kawata, K.; Mukai, H.; Tanabe, H.; Yasuhara, A.

    1996-07-01

    Typical volatile chlorinated hydrocarbons (VCHs), 1,1,1-trichloroethane (methyl chloroform, MCF), and trichloroethane (trichloroethylene, TCE) are used as degreasers or cleaners at electrical plants and metalworks; tetrachloroethane (perchloroethylene, PCE) as well as MCF is representative solve-its for dry cleaning. Tetrachloromethane (perchloromethane, PCM) utilized as material for chemicals. Some amounts of VCHs are lost in the process and are introduced to the environment by some routes. In particular, direct exhaust of VCHs into air is one of the most serious routes; 60 to 90 percents of the VCHs used at some metalworks and relative factories were estimated to be emitted into air. Previously reported were the concentration levels of the VCHs in ambient air at some areas the atmospheric VCH concentrations at industrial areas were affected with some factories which used the VCHs, whereas those at a suburban area were lower than those at industrial regions. Furthermore, they were higher in winter season than in summer season, which might be caused by -meteorological factors. In this paper, aerial variations of VCH concentrations during two to five years at three individual industrial areas (i.e., a metalware and houseware manufacturing area, a textile and dyeing industrial area and a chemical engineering area) are presented. 14 refs., 2 figs., 2 tabs.

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

    PubMed

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

    2013-08-01

    Pollution of groundwater with chlorinated aliphatic hydrocarbons (CAHs) is a serious environmental problem which is threatening human health. Microorganisms are the major participants in degrading these contaminants. Here, groundwater contaminated for a decade with CAHs was investigated. Numerical simulation and field measurements were used to track and forecast the migration and transformation of the pollutants. The diversity, abundance, and possible activity of groundwater microbial communities at CAH-polluted sites were characterized by molecular approaches. The number of microorganisms was between 5.65E+05 and 1.49E+08 16S rRNA gene clone numbers per liter according to quantitative real-time PCR analysis. In 16S rRNA gene clone libraries constructed from samples along the groundwater flow, eight phyla were detected, and Proteobacteria were dominant (72.8 %). The microbial communities varied with the composition and concentration of pollutants. Meanwhile, toluene monooxygenases and methane monooxygenases capable of degradation of PCE and TCE were detected, demonstrating the major mechanism for PCE and TCE degradation and possibility for in situ remediation by addition of oxygen in this study. PMID:23420483

  5. CHLORINE 'DISINFECTION' CHEMISTRY OF AROMATIC COMPOUNDS. POLYNUCLEAR AROMATIC HYDROCARBONS: RATES, PRODUCTS, AND MECHANISMS

    EPA Science Inventory

    The use of chlorine for water renovation and disinfection has been questioned because of the reaction of active chlorine species with organic compounds present in water to form products that may be biologically harmful. Among the organic species known to be present during chlorin...

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

    PubMed

    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. PMID:24445930

  7. Occurrence and profiles of chlorinated and brominated polycyclic aromatic hydrocarbons in waste incinerators.

    PubMed

    Horii, Yuichi; Ok, Gon; Ohura, Takeshi; Kannanct, Kurunthachalam

    2008-03-15

    Chlorinated polycyclic aromatic hydrocarbons (CIPAHs) have been reported to occur in urban air. Nevertheless, sources of CIPAHs in urban air have not been studied, due to the lack of appropriate analytical methods and standards. In this study, we measured concentrations of 20 CIPAHs and 11 brominated PAHs (BrPAHs) in fly ash and bottom ash from 11 municipal/hazardous/industrial waste incinerators, using analytical standards synthesized in our laboratory. Concentrations of total CIPAHs and BrPAHs in ash samples ranged from <0.06 to 6990 ng/g and from <0.14 to 1235 ng/g, respectively. The concentrations of CIPAHs were approximately 100-fold higher than the concentrations of BrPAHs. 6-CIBaP and 1-CIPyr were the dominant compounds in fly ash samples. The profiles of halogenated PAHs were similar to the profiles reported previously for urban air. 1-BrPyr was the predominant BrPAH in fly ash. Concentrations of 6-CIBaP, 9,10-Cl2Phe, 9-CIAnt, and 6-BrBaP in fly ash were significantly correlated with the corresponding parent PAH concentrations. Significant correlation between sigmaCIPAH and sigmaPAH concentrations suggests that direct chlorination of parent PAHs is the mechanism of formation of CIPAHs during incineration of wastes; nevertheless, a comparable correlation was not found for BrPAHs. There was no significant correlation between the capacity and temperature of an incinerator and the concentrations of sigmaCl-/BrPAHs in ash samples, although lower concentrations of all halogenated PAHs were found in stoker-type incinerators than in fixed grate-type incinerators. Toxicity equivalency quotients (TEQs) for CIPAHs in ash samples were calculated with CIPAH potencies. Average TEQ concentrations of CIPAHs in fly ash and bottom ash were15800 pg-TEQ/g and 67 pg-TEQ/g, respectively. Our results suggest that the extent of dioxin-like toxicity contributed by CIPAHs in ash generated during waste incineration is similar to that reported previously for dioxins. Waste

  8. Quantification of Degradation of Chlorinated Hydrocarbons in Saturated Low Permeability Sediments Using Compound-Specific Isotope Analysis.

    PubMed

    Wanner, Philipp; Parker, Beth L; Chapman, Steven W; Aravena, Ramon; Hunkeler, Daniel

    2016-06-01

    This field and modeling study aims to reveal if degradation of chlorinated hydrocarbons in low permeability sediments can be quantified using compound-specific isotope analysis (CSIA). For that purpose, the well-characterized Borden research site was selected, where an aquifer-aquitard system was artificially contaminated by a three component chlorinated solvent mixture (tetrachloroethene (PCE) 45 vol %, trichloroethene (TCE) 45 vol %, and chloroform (TCM) 10 vol %). Nearly 15 years after the contaminant release, several high-resolution concentration and CSIA profiles were determined for the chlorinated hydrocarbons that had diffused into the clayey aquitard. The CSIA profiles showed large shifts of carbon isotope ratios with depth (up to 24‰) suggesting that degradation occurs in the aquitard despite the small pore sizes. Simulated scenarios without or with uniform degradation failed to reproduce the isotope data, while a scenario with decreasing degradation with depth fit the data well. This suggests that nutrients had diffused into the aquitard favoring stronger degradation close to the aquifer-aquitard interface than with increasing depth. Moreover, the different simulation scenarios showed that CSIA profiles are more sensitive to different degradation conditions compared to concentration profiles highlighting the power of CSIA to constrain degradation activities in aquitards. PMID:27153381

  9. Assessing breeding potential of peregrine falcons based on chlorinated hydrocarbon concentrations in prey.

    PubMed

    Elliott, J E; Miller, M J; Wilson, L K

    2005-03-01

    Peregrine falcons (Falco peregrinus) now breed successfully in most areas of North America from which they were previously extirpated. The loss during the mid-part of the last century of many of the world's peregrine populations was largely a consequence of impaired reproduction caused by the effects of DDE on eggshell quality and embryo hatchability. Population recovery has been attributed to re-introduction efforts, coupled with regulatory restrictions on the use of organochlorine pesticides. Peregrines have not returned to breed in some areas, such as the Okanagan Valley of British Columbia. That region has been extensively planted in fruit orchards which were treated annually with DDT during the early 1950s to the 1970s. Ongoing contamination of avian species, including potential peregrine prey, inhabiting orchards has been documented. In response to an initiative to release peregrines around the city of Kelowna in the Okanagan Valley, we collected potential peregrine prey species and analyzed whole bodies for chlorinated hydrocarbon residues. We used a simple bioaccumulation model to predict concentrations of DDE in peregrine eggs using concentrations in prey and estimates of dietary makeup as input. Peregrines would be expected to breed successfully only if they fed on a diet primarily of doves. Feeding on as little as 10% of other species such as starlings, robins, gulls and magpies would produce DDE concentrations in peregrine eggs greater than the threshold of 15 mg/kg. We also estimated the critical concentration of DDE in total prey to be about 0.5 mg/kg, one half of the previous most conservative criterion for peregrine prey. Concentrations of dieldrin and PCBs in peregrine prey are less than suggested critical levels. PMID:15589662

  10. Eggshell thinning, chlorinated hydrocarbons, and mercury in inland aquatic bird eggs, 1969 and 1970

    USGS Publications Warehouse

    Faber, R.A.; Hickey, J.J.

    1973-01-01

    In the Upper Great Lakes States, 9 out of 13 species of fish-eating birds were found in 1969-70 to have sustained statistically significant decreases in eggshell thickness since 1946. Maximum changes in a thickness index occurred in great blue herons (-25%), red-breasted mergansers (-23%), common mergansers (-15%). and double-crested cormorants (-15%). Heron eggs taken in Louisiana generally displayed a smaller post-'46 change than herons in the Middle West. On a lipid basis, mean PCB- and DDE- residue levels exceeded 100 ppm in 7 out of 13 species in the Great Lakes States, and in 2 of 7 species in Louisiana, the average DDE: PCB ratios in the two regions being 1.25:1 and 3.9:1, respectively. Individual dieldrin values tended 10 be higher in Louisiana (31.6 and 13.95 ppm in heron species from two different locations), although values reached 10.1 and 9.4 ppm in great blue and black-crowned night herons in Wisconsin. BHC averaged 3.01 and 0.39 ppm in the Lake States and Louisiana, respectively. Of eggs examined for mercury. 29% had levels greater than 0.5 ppm, and 9% greater than 1.0 ppm on a wet-weight basis. Mercury levels in a small sample of eggs from Louisiana were consistently low. The differences in mercury levels between the two regions thus were similar to those found for the chlorinated hydrocarbons. While DDE was a prominent factor for most groups, especially herons, in relation to the eggshell thinning observed, dieldrin was also important to two groups even though DDE was present in much higher amounts. PCB's were also important to mergansers, while mercury was positively correlated with thickness index in grebes and negatively correlated in mergansers.

  11. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    USGS Publications Warehouse

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (< 1-34 ng/g). PCBs are first detected in sediment deposited during the 1930's in Richardson Bay, about a decade earlier than the onset of detectable levels of DDTs. PCB inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  12. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

    NASA Astrophysics Data System (ADS)

    Powell, C. L.; Goltz, M. N.; Agrawal, A.

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  13. Effects of Occupational Exposure to Mercury or Chlorinated Hydrocarbons on the Auditory Pathway.

    PubMed

    Moshe, Shlomo; Frenkel, Avraham; Hager, Moshe; Skulsky, Mario; Sulkis, Jacklin; Himelfarbe, Mordechai

    2002-01-01

    The purpose of this study was to examine the effects of industrial exposure to mercury and chlorinated hydrocarbons (CH) on the auditory pathway. To this effect, auditory brainstem responses (ABR) were recorded from 40 workers exposed to mercury, 37 workers exposed to CH and from a control group of 36 subjects that were never exposed to neurotoxic substances. The interpeak latency (IPL) of waves I-III, III-V and I-V were measured. The mean duration of exposure to mercury and CH was 15.5 (+6.4) and 15.8 (+7.2) years respectively. The air sample monitoring of mercury was 0.008 mg/m(3) (0.32 of the Threshold Limit Value - TLV(R) as published by ACGIH 2000). The mean average air sample monitoring was found to be 98 ppm for TCE, 12.7 ppm for PCE and 14.4 ppm for TCA which is respectively between 0.28 - 0.51 of the TLV(R) of CH. The mean blood mercury (B-Hg) levels were found to be 0.5mgr% (+0.3mgr%), which is 0.13 of the upper range of the permitted biologic exposure index (BEI) published by the ACGIH 2000. The mean urine samples levels of trichloroacetic acid were between 0.11-0.2 of the permitted BEI for the CH workers. The percent of workers exposed to mercury and CH workers with abnormal prolongation of IPL I-III was higher than the control group (42.5% and 33.8% vs. 18.0% respectively p<0.02). These results are consistent with other studies and show that ABR may provide a sensitive tool for detecting subclinical central neurotoxicity caused by CH and mercury PMID:12537844

  14. Determination of volatile chlorinated hydrocarbons in water samples by static headspace gas chromatography with electron capture detection.

    PubMed

    Li, Tiejun; Guo, Yuanming; Hu, Hongmei; Zhang, Xiaoning; Jin, Yanjian; Zhang, Xiaojun; Zhang, Yurong

    2016-01-01

    A simple, efficient, solvent-free, and commercial readily available approach for determination of five volatile chlorinated hydrocarbons in water samples using the static headspace sampling and gas chromatography with electron capture detection has been described. The proposed static headspace sampling method was initially optimized and the optimum experimental conditions found were 10 mL water sample containing 20% w/v sodium chloride placed in a 20 mL vial and stirred at 50ºC for 20 min. The linearity of the method was in the range of 1.2-240 μg/L for dichloromethane, 0.2-40 μg/L for trichloromethane, 0.005-1 μg/L for perchloromethane, 0.025-5 μg/L for trichloroethylene, and 0.01-2 μg/L for perchloroethylene, with coefficients of determination ranging between 0.9979 and 0.9990. The limits of detection were in the low μg/L level, ranging between 0.001 and 0.3 μg/L. The relative recoveries of spiked five volatile chlorinated hydrocarbons with external calibration method at different concentration levels in pure, tap, sea water of Jiaojiang Estuary, and sea water of waters of Xiaomendao were in the range of 91-116, 96-105, 86-112, and 80-111%, respectively, and with relative standard deviations of 1.9-3.6, 2.3-3.5, 1.5-2.7, and 2.3-3.7% (n = 5), respectively. The performance of the proposed method was compared with traditional liquid-liquid extraction on the real water samples (i.e., pure, tap, and sea water, etc.) and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of volatile chlorinated hydrocarbons in different water samples. PMID:26805957

  15. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

    PubMed

    Powell, C L; Goltz, M N; Agrawal, A

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds. PMID:25444117

  16. Synergistic degradation of chlorinated hydrocarbons with microorganisms and zero valent iron

    NASA Astrophysics Data System (ADS)

    Schöftner, Philipp; Summer, Dorothea; Leitner, Simon; Watzinger, Andrea; Wimmer, Bernhard; Reichenauer, Thomas

    2016-04-01

    Sites contaminated with chlorinated hydrocarbons (CHC) are located mainly within build-up regions. Therefore in most cases only in-situ technologies without excavation of soil material can be used for remediation. This project examines a novel in-situ remediation method, in which the biotic degradation via bacteria is combined with abiotic degradation via zero-valent iron particles (ZVI). ZVI particles are injected into the aquifer where CHC-molecules are reductively dechlorinated. However Fe0 is also oxidized by reaction with water leading to generation of H2 without any CHC degradation. To achieve biotic degradation often strictly anaerobic strains of the bacteria Dehalococcoides are used. These bacteria can dechlorinate CHC by utilizing H2. By combining these processes the H2, produced during the anaerobic corrosion of Fe0, could be used by bacteria for further CHC degradation. Therefore the amount of used Fe0 and as a consequence also remediation costs could be reduced. Additionally the continuous supply of H2 could make the bacterial degradation more controllable. Different Fe0 particles (nano- and micro-scale) were tested for their perchloroethene (PCE) degradation rate and H2 production rate in microcosms. PCE-degradation rate by different bacterial cultures was investigated in the same microcosm system. In course of these experiments the 13C enrichment factors of the PCE degradation of the different particles and cultures were determined to enable the differentiation of biotic and abiotic degradation. Preliminary results showed, that the nano-scale particles reacted faster with PCE and water than their micro-scaled counterparts. The PCE degradation via micro-scaled particles lead to 13C enrichment factors in the range of -3,6 ‰ ± 0,6 to -9,5 ‰ ± 0,2. With one of the examined bacterial cultures a fast reduction of PCE to ethene was observed. Although PCE and TCE were completely degraded by this culture the metabolites DCE and VC could still be detected

  17. Patterns and trends of chlorinated hydrocarbons in nestling bald eagle (Haliaeetus leucocephalus) plasma in British Columbia and Southern California.

    PubMed

    Cesh, Lillian S; Williams, Tony D; Garcelon, David K; Elliott, John E

    2008-10-01

    Patterns and trends of chlorinated hydrocarbons were assessed in bald eagle nestling plasma from sites along the west coast of North America. Eagle plasma was sampled from four areas in southwestern British Columbia (BC), a reference site in northern BC, and from Santa Catalina Island, off the coast of California. Sites were chosen to reflect variation in contaminant exposure due to differing recent and/or historic anthropogenic activities. Santa Catalina Island had significantly greater mean concentrations of p,p'-DDE, 41.3 microg/kg wet weight (ww), than other sites, and Nanaimo/Crofton, BC had the greatest mean concentration of total PCBs, 28.9 microg/kg ww. Contaminant levels measured in 2003 in BC were compared to levels measured in 1993; over that ten year span, concentrations and patterns of chlorinated hydrocarbons have not significantly changed. There were no significant differences in levels of p,p'-DDE or hexachlorobenzene between 1993 and 2003, but significant decreases were found for trans-nonachlor and PCBs at BC sites. Levels of total PCBs and trans-nonachlor in the central Fraser Valley and Nanaimo/Crofton area have significantly decreased. Mean concentrations of p,p'-DDE measured in bald eagle nestling plasma samples in 2003 exceeded published criteria for effects on bald eagle reproduction at Santa Catalina Island and Barkley Sound, more than 30 years since heavy usage restrictions were imposed. PMID:18253687

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

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.; Cabane, Michael; Coll, Patrice; Conrad, Pamela G.; Coscia, David; Dworkin, Jason P.; Franz, Heather B.; Grotzinger, John P.; Leshin, Laurie A.; Martin, Mildred G.; McKay, Christopher; Ming, Douglas W.; Navarro-Gonzalez, Rafael; Pavlov, Alexander; Steele, Andrew; Summons, Roger E.; Szopa, Cyril; Teinturier, Samuel; Mahaffy, Paul R.

    2013-01-01

    Four individual sample portions from a single scoop of the Rocknest aeolian deposit were sieved ( 150 m) and delivered to the Sample Analysis at Mars (SAM) instrument by the Mars Science Laboratory rover's sample acquisition system. The samples were analyzed separately by the SAM pyrolysis evolved gas and gas chromatography mass spectrometry analysis modes. Several chlorinated hydrocarbons including chloromethane, dichloromethane, trichloromethane, a chloromethylpropene, and chlorobenzene were identified by SAM above background levels with abundances of 0.01 to 2.3 nanomole.The evolution of the chloromethanes observed during pyrolysis is coincident with the increase in O2 released from the Rocknest sample and the decomposition of a product of N-methyl-N- (tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), a chemical that leaked from a derivatization cup inside SAM.The best candidate for the oxychloride phase in Rocknest is a hydrated calcium perchlorate (Ca(ClO4)2nH2O), based on the temperature release of O2 that correlates with the release of the chlorinated species measured by SAM, although other chlorine bearing phases are being considered. Laboratory pyrolysis experiments suggest that reaction of martian chlorine with organic carbon from MTBSTFA can explain the presence of the chloromethanes and a chloromethylpropene also detected by SAM.However, we cannot exclude the possibility that traces of organic carbon of either martian or exogenous origin contributed to some of the chloromethanes measured by SAM. Although the alteration history and exposure age of the Rocknest deposit is unknown, it is possible that oxidative degradation of complex organic matter by ionizing radiation or other chemical processes in Rocknest has occurred.

  19. Polyethylene as a source of artifacts in the paper chromatography of chlorinated hydrocarbon insecticides

    USGS Publications Warehouse

    Van Valin, C.C.; Kallman, B.J.; O'Donnell, J.J, Jr.

    1963-01-01

    The introduction of artifacts from vessels, materials, and chemicals is a serious problem in the study of pesticide residues. It is therefore of interest to record findings that polyethylene wash bottles contain substances soluble in organic solvents and reactive with the silver nitrate chromogenic spray commonly employed in the paper chromatographic analysis of chlorinated organic insecticides.

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

    EPA Science Inventory

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

  1. The indirect determination of chlorine atom concentration in the troposphere from changes in the patterns of non-methane hydrocarbons

    NASA Astrophysics Data System (ADS)

    Rudolph, J.; Ramacher, B.; Plass-Dülmer, C.; Müller, K.-P.; Koppmann, R.

    1997-11-01

    About 200 measurements of C2 C9 hydrocarbons were made during a ship cruise (NATAC 91) in the western Mediterranean Sea, the eastern Mid- and North Atlantic and the North Sea in April and May 1991. The changes in the ratios of several pairs of hydrocarbons are used to investigate the possible impact of Cl-atom reactions on the atmospheric removal processes of hydrocarbons. In order to minimize the potential bias from atmospheric mixing processes, a careful selection of suitable hydrocarbon sets is essential. The NMHC mixing ratios observed during NATAC 91 are generally well above those typical for air in the remote marine background and the observed changes in the hydrocarbon patterns agree very well with those predicted from OH-radical chemistry. No significant evidence for an impact of chlorine atoms could be found in this data set. The best estimate for the average [Cl]/[OH] ratio is in the range of 10-3. However, within the various uncertainties associated with such estimates, this value is not significantly different from zero. The upper limit is in the range of 2 7·10-3. Based on an average OH-radical concentration of 106 cm-3, this corresponds to some 103 Cl-atoms cm-3. This is far below the Cl-atom concentrations found during the tropospheric ozone depletion events in arctic spring. Our values are also far below those derived in some other studies for the marine boundary layer but are still compatible with recent model calculations. Our findings support the conclusion of Rudolph and coworkers that on average, Cl-atoms are of limited importance for the chemistry of the troposphere. It is important that

  2. PLANAR CHLORINATED HYDROCARBONS (PCHS) IN COLONIAL FISH-EATING WATERBIRD EGGS FROM THE GREAT LAKES

    EPA Science Inventory

    Reproductive impairment of double-crested cormorants (Phalacrocorax auritis) and Caspian terns Hydroprogne caspia) has recently been observed in the Great Lakes of North America. lanarchlorinated hydrocarbons (PCHs), which include polychlorinated biphenyls (PCBs), polychlorinated...

  3. Use of tree rings to investigate the onset of contamination of a shallow aquifer by chlorinated hydrocarbons

    USGS Publications Warehouse

    Yanosky, T.M.; Hansen, B.P.; Schening, M.R.

    2001-01-01

    Oaks (Quercus velutina Lam.) growing over a shallow aquifer contaminated by chlorinated hydrocarbons were studied to determine if it was possible to estimate the approximate year that contamination began. The annual rings of some trees downgradient from the contaminant release site contained elevated concentrations of chloride possibly derived from dechlorination of contaminants. Additionally, a radial-growth decline began in these trees at approximately the same time that chloride became elevated. Growth did not decline in trees that contained smaller concentrations of chloride. The source of elevated chloride and the corresponding reductions in tree growth could not be explained by factors other than contamination. On the basis of tree-ring evidence alone, the release occurred in the late 1960s or early 1970s. Contaminant release at a second location apparently occurred in the mid- to late 1970s, suggesting that the area was used for disposal for at least 5 years and possibly longer. Copyright ?? 2001 Elsevier Science B.V.

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

    PubMed

    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. PMID:21128271

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

    PubMed

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

    2013-07-01

    In this study, we hypothesize that natural photochemical reactions of polycyclic aromatic hydrocarbons (PAHs) in tidal flats are responsible for the occurrence of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs). This study aims to survey the impact of photochemical reactions using a combination of field surveys and lab-scale experiments. Concentrations and profiles of PAHs and Cl-PAHs in road dust and sediments collected from seven tunnels and two watersheds, respectively, were determined. In the lab-scale experiments, anthracene was irradiated with ultraviolet (UV) light under various salinity conditions. No detectable Cl-PAHs were found in the road dust. However, Cl-PAHs were detected in the sediments from 700 to 6.1 × 10(3) pg g(-1) and specifically from downstream sites. 2-Monochloroanthracene (2-Cl-ANT) and 9,10-dichloroanthracene (9,10-di-Cl-ANT) were dominant in the sediments. In the Domen River watershed, the ∑Cl-PAHs and the salinity showed a significant positive correlation (p < 0.01) in the sediments, while such a correlation was not found for PAHs. 2-Cl-ANT, 9-monochloroanthracene, and 9,10-di-Cl-ANT were identified as transformation products in the UV irradiation experiments. Production of these Cl-PAHs was dependent on the solution salinity. These results support our hypothesis, and we conclude that photochemical reactions significantly contribute to the occurrence of Cl-PAHs in the studied tidal flats. PMID:23452146

  6. BIOTRANSFORMATION OF MONOAROMATIC AND CHLORINATED HYDROCARBONS AT AN AVIATION GASOLINE SPILL SITE

    EPA Science Inventory

    A shallow water table aquifer under the U.S Coast Guard Air Station at Traverse City, MI, has acclimated to the aerobic and anaerobic transformation of monoaromatic hydrocarbons (BTX) released from an aviation gasoline spill. he aquifer also exhibits reductive dechlorination of a...

  7. TAILORING CATALYSTS FOR HYDRODECHLORINATING CHLORINATED HYDROCARBON CONTAMINANTS IN GROUNDWATER. (R825689C078)

    EPA Science Inventory

    Abstract

    A palladium-on-zeolite catalyst has been optimized for treating groundwater contaminated with halogenated hydrocarbon compounds (HHCs) by hydrodechlorination with dissolved hydrogen. Aqueous sulfite was used as the model poison and the dechlorination of 1,2-di...

  8. TAILORING CATALYSTS FOR HYDRODECHLORINATING CHLORINATED HYDROCARBON CONTAMINANTS IN GROUNDWATER. (R825689C093)

    EPA Science Inventory

    Abstract

    A palladium-on-zeolite catalyst has been optimized for treating groundwater contaminated with halogenated hydrocarbon compounds (HHCs) by hydrodechlorination with dissolved hydrogen. Aqueous sulfite was used as the model poison and the dechlorination of 1,2-di...

  9. BIOTRANSFORMATION OF MONOAROMATIC AND CHLORINATED HYDROCARBONS AT AN AVIATION GASOLINE SPILL SITE

    EPA Science Inventory

    A shallow water table aquifer under the U.S. Coast Guard Air Station at Traverse City, MI, has acclimated to the aerobic and anaerobic transformation of monoaromatic hydrocarbons (BTX) released from an aviation gasoline spill. The aquifer also exhibits reductive dechlorination of...

  10. Chlorinated hydrocarbons in the marine environment. A report prepared by the Panel on Monitoring Persistent Pesticides in the Marine Environment of the Committee on Oceanography

    USGS Publications Warehouse

    Panel on Monitoring Persistent Pesticides in the Marine Environment; Goldberg, E.D.; Butler, P.; Meier, P.; Menzel, D.; Paulik, G.; Risebrough, R.; Stickel, L.F.

    1971-01-01

    SUMMARY AND RECOMMENDATIONS : The oceans are an ultimate accumulation site for the persistent chlorinated hydrocarbons. As much as 25 percent of the DDT compounds produced to date may have been transferred to the sea. The amount of DDT compounds in the marine biota is estimated to be less than 0.1 percent of total production, yet this amount has produced a demonstrable impact upon the marine environment. Populations of fish-eating birds have experienced reproductive failure and decline. With continued accumulations of persistent chlorinated hydrocarbons in the marine ecosystem, additional species will be threatened. Continued release of these pollutants to the environment can only accelerate the accumulation of unacceptable levels of persistent chlorinated hydrocarbons in the tissues of marine food fish. Certain risks in the utilization of chlorinated hydrocarbons are especially hard to quantify, but they require serious consideration. The rate at which such substances degrade to harmless products in the marine system is unknown; the half-lives of some of the more persistent materials are certainly of the order of years, and perhaps even of decades or centuries. If most of the remaining 75 percent of the persistent chlorinated hydrocarbons is now in reservoirs that will in time transfer their contents to the sea, we may expect an increased level of these substances in marine organisms, despite future improvements of manufacturing practices. In fact, if these compounds degrade with half-lives of decades or longer, there will be no opportunity to redress the consequences. The more the problems are studied, the more unexpected effects are identified. In view of the findings of the past decade, our prediction of the potential hazards of chlorinated hydrocarbons in the marine environment may be vastly underestimated. The Panel makes the following recommendations, which will be developed and expanded in the remainder of the report: ? A massive national effort should be

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

    USGS Publications Warehouse

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

    1998-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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. Σ PAH concentrations in air and rainwater ranged from 0.7 to 327.9 ng m-3 and below analytical method detection limit (< MDL) to 2.1 × 103 ng L-1. The concentrations of PCBs and CPs in rainwater were < MDL. Σ PCB and Σ CP concentrations in air ranged from < MDL to 44.6 and < MDL 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 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Chlorinated hydrocarbons in early life stages of the common snapping turtle (Chelydra serpentina serpentina) from a coastal wetland on Lake Ontario, Canada

    SciTech Connect

    Bishop, C.A.; Lean, D.R.S.; Carey, J.H.; Brooks, R.J.; Ng, P.

    1995-03-01

    To assess intra-clutch variation in contaminant concentrations in eggs, and to investigate the dynamics of chlorinated hydrocarbon accumulation in embryos of the common snapping turtle (Chelydra serpentina), concentrations of p,p{prime}-DDE, hexachlorobenzene, trans-nonachlor, cis-chlordane, and six PCB congeners were measured in eggs, embryos, and hatchlings. Samples were collected from Cootes Paradise, a wetland at the western end of Lake Ontario, Ontario, Canada. The intra-clutch variation in chlorinated hydrocarbon concentrations within four snapping turtle clutches was determined by analyzing the first, last, and middle five eggs oviposited in the nest. The first five eggs had the highest mean concentrations of all chlorinated hydrocarbons, wet weight, and egg diameter. On a lipid weight basis, the first five eggs contained the highest concentration of all compounds except total PCBs and cis-chlordane. The concentration of cis-chlordane was the only parameter measured that was significantly different among the three sets of eggs. At hatching, snapping turtles without yolk sacs contained from 55.2 to 90.5% of the absolute amount of organochlorine compounds measured in the egg at oviposition. Eighteen days after hatching, the body burden of PCBs and pesticides decreased to 45.3 to 62.2% of that in the fresh egg. The accumulation of organochlorine chemicals in embryonic turtles peaked at or just before hatching and then declined thereafter, which is consistent with trends reported in developing sea turtles, fish, and birds.

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

    PubMed Central

    2013-01-01

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

  16. Secondary aerosol formation from the oxidation of biogenic hydrocarbons by chlorine atoms

    NASA Astrophysics Data System (ADS)

    Cai, Xuyi; Griffin, Robert J.

    2006-07-01

    The chlorine atom (Cl) is a potential oxidant of volatile organic compounds (VOCs) in the atmosphere and is hypothesized to lead to secondary organic aerosol (SOA) formation in coastal and industrialized areas. The purpose of this paper is to test this hypothesis and to quantify the SOA formation potentials of the common monoterpenes α-pinene, β-pinene, and d-limonene when oxidized by Cl in laboratory chamber experiments. Results indicate that the oxidation of these monoterpenes generates significant amounts of aerosol. The SOA yields of α-pinene, β-pinene, and d-limonene in this study are comparable to those when they are oxidized by ozone, by nitrate radical, and in photooxidation scenarios. For aerosol mass up to 30.0 μg m-3, their yields reach approximately 0.20, 0.20, and 0.30, respectively. For d-limonene, data indicate two yield curves that depend on the initial concentration ratio of Cl precursor to d-limonene. It is argued theoretically that multiple SOA yield curves may be common for VOCs, depending on the initial concentration ratio of oxidant to VOC. SOA formation from the three typical monoterpenes when oxidized by Cl in the marine boundary layer, coastal areas, and inland industrialized areas could be a source of organic aerosol in the early morning.

  17. Optimisation of an integrated optical evanescent wave absorbance sensor for the determination of chlorinated hydrocarbons in water.

    PubMed

    Mayer, J; Bürck, J; Ache, H J

    1996-03-01

    The suitability of an integrated optical chemical sensor for the determination of highly volatile chlorinated hydrocarbons in aqueous solutions has been proven. The analytes are detected by NIR absorption spectrometry in the evanescent field of an integrated optical strip waveguide generated in a BGG31 (Schott, Germany) glass substrate, which is coated with a hydrophobic polymer superstrate as sensing layer. It has been shown that the sensitivity increases when the refractive index of the superstrate is increased from 1.333 up to 1.46. Different UV-cured polysiloxanes with low cross sensitivity to water have been prepared. Due to the good light transmission properties of the IO-sensors prepared by this method, quantitative measurements have been performed with the model system trichloroethene (TCE) in water. A detection limit of 22 ppm has been found and the sensor response times (t(90)-value) are between five and fourteen minutes for a coating thickness of around 30 microm. The sensor response is totally reversible. The analyte desorbes in air within 2 min. The enrichment of trichloroethene in the polysiloxane coating can be described by film diffusion through the aqueous boundary layer as rate determining step. PMID:15048399

  18. Monitoring the effect of poplar trees on petroleum-hydrocarbon and chlorinated-solvent contaminated ground water

    USGS Publications Warehouse

    Landmeyer, J.E.

    2001-01-01

    At contaminated groundwater sites, poplar trees can be used to affect groundwater levels, flow directions, and ultimately total groundwater and contaminant flux to areas downgradient of the trees. The magnitude of the hydrologic changes can be monitored using fundamental concepts of groundwater hydrology, in addition to plant physiology-based approaches, and can be viewed as being almost independent of the contaminant released. The affect of poplar trees on the fate of groundwater contaminants, however, is contaminant dependent. Some petroleum hydrocarbons or chlorinated solvents may be mineralized or transformed to innocuous compounds by rhizospheric bacteria associated with the tree roots, mineralized or transformed by plant tissues in the transpiration stream or leaves after uptake, or passively volatilized and rapidly dispersed or oxidized in the atmosphere. These processes also can be monitored using a combination of physiological- or geochemical-based field or laboratory approaches. When combined, such hydrologic and contaminant monitoring approaches can result in a more accurate assessment of the use of poplar trees to meet regulatory goals at contaminated groundwater sites, verify that these goals continue to be met in the future, and ultimately lead to a consensus on how the performance of plant-based remedial strategies (phytoremediation) is to be assessed.

  19. Impact of carbon, oxygen and sulfur content of microscale zerovalent iron particles on its reactivity towards chlorinated aliphatic hydrocarbons.

    PubMed

    Velimirovic, Milica; Larsson, Per-Olof; Simons, Queenie; Bastiaens, Leen

    2013-11-01

    Zerovalent iron (ZVI) abiotically degrades several chlorinated aliphatic hydrocarbons (CAHs) via reductive dechlorination, which offers perspectives for in situ groundwater remediation applications. The difference in reactivity between ZVI particles is often linked with their specific surface area. However, other parameters may influence the reactivity as well. Earlier, we reported for a set of microscale zerovalent iron (mZVI) particles the disappearance kinetic of different CAHs which were collected under consistent experimental conditions. In the present study, these kinetic data were correlated with the carbon, oxygen and sulfur content of mZVI particles. It was confirmed that not only the specific surface area affects the disappearance kinetic of CAHs, but also the chemical composition of the mZVI particles. The chemical composition, in addition, influences CAHs removal mechanism inducing sorption onto mZVI particles instead of dechlorination. Generally, high disappearance kinetic of CAHs was observed for particles containing less oxygen. A high carbon content, on the other hand, induced nonreactive sorption of the contaminants on the mZVI particles. To obtain efficient remediation of CAHs by mZVI particles, this study suggested that the carbon and oxygen content should not exceed 0.5% and 1% respectively. Finally, the efficiency of the mZVI particles may be improved to some extent by enriching them with sulfur. However, the impact of sulfur content on the reactivity of mZVI particles is less pronounced than that of the carbon and oxygen content. PMID:23962383

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

    PubMed

    Ohura, Takeshi; Kamiya, Yuta; Ikemori, Fumikazu

    2016-07-15

    Concentrations of particle-bound polycyclic aromatic hydrocarbons (PAHs) and chlorinated PAHs (ClPAHs) were measured in different seasons at five sampling stations in Nagoya, a Japanese megacity. The annual mean total ClPAH and total PAH concentrations were 43.3-92.6pg/m(3) and 5200-8570pg/m(3), respectively. The concentrations of total ClPAHs were significantly variable than those of total PAHs, and both total concentrations through the seasons did not significantly correlate at any of the stations. Principal component analysis was used to characterize the ClPAH sources, resulted that ClPAHs were found to be associated with the sources of high-molecular-weight PAHs in the warmer seasons and of low-molecular-weight PAHs in the colder seasons. These findings suggest that principal sources of particle-bound ClPAHs are present in the local area, and change in the seasons. Toxic equivalent (TEQ) concentrations were estimated to assess the risks associated with exposure to ClPAHs in air. The TEQ concentrations in the samples were 0.05-0.32pg-TEQ/m(3). The TEQ concentrations in summer were approximately half the TEQ concentrations in the other seasons at all of the stations. PMID:27037480

  1. Comparison of purge and trap GC/MS and purgeable organic chloride analysis for monitoring volatile chlorinated hydrocarbons

    USGS Publications Warehouse

    Barber, Larry B.; Thurman, E. Michael; Takahashi, Yoshi; Noriega, Mary C.

    1992-01-01

    A combined field and laboratory study was conducted to compare purge and trap gas chromatography/mass spectrometry (PT-GC/MS) and purgeable organic chloride (POCl) analysis for measuring volatile chlorinated hydrocarbons (VCH) in ground water. Distilled-water spike and recovery experiments using 10 VCH indicate that at concentrations greater than 1 ??g/l recovery is more than 80 percent for both methods with relative standard deviations of about 10 percent. Ground-water samples were collected from a site on Cape Cod, Massachusetts, where a shallow unconfined aquifer has been contaminated by VCH, and were analyzed by both methods. Results for PT-GC/MS and POCl analysis of the ground-water samples were not significantly different (alpha = 0.05, paired t-test analysis) and indicated little bias between the two methods. Similar conclusions about concentrations and distributions of VCH in the ground-water contamination plume were drawn from the two data sets. However, only PT-GC/MS analysis identified the individual compounds present and determined their concentrations, which was necessary for toxicological and biogeochemical evaluation of the contaminated ground water. POCl analysis was a complimentary method for use with PT-GC/MS analysis for identifying samples with VCH concentrations below the detection limit or with high VCH concentrations that require dilution. Use of POCl as a complimentary monitoring method for PT-GC/MS can result in more efficient use of analytical resources.

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

    NASA Astrophysics Data System (ADS)

    Alberti, Luca; Lombi, Silvia; Zanini, Andrea

    2011-09-01

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

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

    PubMed

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

    1999-02-01

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

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

    SciTech Connect

    Strand, Stuart E.

    2004-12-01

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

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

    PubMed

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

    2016-01-01

    We investigated the kinetics of in vitro transformation of a dichlorinated propyl paraben (2-propyl 3,5-dichloro-4-hydroxybenzoate; Cl2PP) by the rat liver S9 fraction and assessed the aryl hydrocarbon receptor (AhR) agonist activity of the metabolite products identified in HPLC and GC/MS analysis and by metabolite syntheses. The results indicated that the chlorination of Cl2PP reduced its degradation rate by approximately 40-fold. Two hydroxylated metabolite products showed AhR agonist activity of up to 39% of that of the parent Cl2PP when assessed in a yeast (YCM3) reporter gene assay. The determination of the metabolic properties of paraben bioaccumulation presented here provides further information on the value of risk assessments of chlorinated parabens as a means to ensure human health and environmental safety. PMID:27250800

  6. Environmental analysis of chlorinated and brominated polycyclic aromatic hydrocarbons by comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry.

    PubMed

    Ieda, Teruyo; Ochiai, Nobuo; Miyawaki, Toshifumi; Ohura, Takeshi; Horii, Yuichi

    2011-05-27

    A method for the analysis of chlorinated and brominated polycyclic aromatic hydrocarbon (Cl-/Br-PAHs) congeners in environmental samples, such as a soil extract, by comprehensive two-dimensional gas chromatography coupled to a high resolution time-of-flight mass spectrometry (GC×GC-HRTOF-MS) is described. The GC×GC-HRTOF-MS method allowed highly selective group type analysis in the two-dimensional (2D) mass chromatograms with a very narrow mass window (e.g. 0.02Da), accurate mass measurements for the full mass range (m/z 35-600) in GC×GC mode, and the calculation of the elemental composition for the detected Cl-/Br-PAH congeners in the real-world sample. Thirty Cl-/Br-PAHs including higher chlorinated 10 PAHs (e.g. penta, hexa and hepta substitution) and ClBr-PAHs (without analytical standards) were identified with high probability in the soil extract. To our knowledge, highly chlorinated PAHs, such as C(14)H(3)Cl(7) and C(16)H(3)Cl(7), and ClBr-PAHs, such as C(14)H(7)Cl(2)Br and C(16)H(8)ClBr, were found in the environmental samples for the first time. Other organohalogen compounds; e.g. polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzofurans (PCDFs) were also detected. This technique provides exhaustive analysis and powerful identification for the unknown and unconfirmed Cl-/Br-PAH congeners in environmental samples. PMID:21316690

  7. Distributions and fate of chlorinated pesticides, biomarkers and polycyclic aromatic hydrocarbons in sediments along a contamination gradient from a point-source in San Francisco Bay, California

    USGS Publications Warehouse

    Pereira, W.E.; Hostettler, F.D.; Rapp, J.B.

    1996-01-01

    The distribution and fate of chlorinated pesticides, biomarkers, and polycyclic aromatic hydrocarbons (PAHs) in surficial sediments along a contamination gradient in the Lauritzen Canal and Richmond Harbor in San Francisco Bay was investigated. Compounds were identified and quantified using gas chromatography-ion trap mass spectrometry. Biomarkers and PAHs were derived primarily from weathered petroleum. DDT was reductively dechlorinated under anoxic conditions to DDD and several minor degradation products, DDMU, DDMS, and DDNU. Under aerobic conditions, DDT was dehydrochlorinated to DDE and DBP. Aerobic degradation of DDT was diminished or inhibited in zones of high concentration, and increased significantly in zones of lower concentration: Other chlorinated pesticides identified in sediment included dieldrin and chlordane isomers. Multivariate analysis of the distributions of the DDTs suggested that there are probably two sources of DDD. In addition, DDE and DDMU are probably formed by similar mechanisms, i.e. dehydrochlorination. A steep concentration gradient existed from the Canal to the Outer Richmond Harbor, but higher levels of DDD than those found in the remainder of the Bay indicated that these contaminants are transported on particulates and colloidal organic matter from this source into San Francisco Bay. Chlorinated pesticides and PAHs may pose a potential problem to biota in San Francisco Bay.

  8. Electrochemical continuous decomposition of chloroform and other volatile chlorinated hydrocarbons in water using a column type metal impregnated carbon fiber electrode

    SciTech Connect

    Sonoyama, Noriyuki; Sakata, Tadayoshi

    1999-10-01

    Trihalomethane and other chlorinated hydrocarbons are known to be toxic to human health. However, removal of these compounds from water is not easy. The authors attempted continuous electrochemical decomposition of chloroform that is the main compound of trihalomethanes and some toxic chlorinated hydrocarbons in water using a metal-impregnated CFE, concentration of chloroform in 0.5 M K{sub 2}SO{sub 4} (the supporting electrolyte) solution was decreased from 0.23m mol/L to below the limit of detection of their analysis system (1 ppm) at a flow rate of 1 mL/min. The main product of electrolysis was methane. This high efficiency, determined by the chemical yield, hardly changed at a flow rate of 20 mL/min at a Ag-impregnated CFE. At a flow rate of 1 mL/min, chloroform was degraded with a decomposition efficiency of almost 100% even in the solution without the supporting electrolyte, whereas at a higher flow rate, the efficiency for the decomposition of chloroform decreased with a decrease in the concentration of the supporting electrolyte. Tetrachloroethylene, 1,1,1-trichloroethane, and 1,1,2-trichloroethane were also decomposed at a Ag-impregnated CFE with an efficiency of almost 100%.

  9. Chlorinated hydrocarbons and mercury in sediments, red-winged blackbirds (Agelaius phoeniceus) and tree swallows (Tachycineta bicolor) from wetlands in the Great Lakes-St. Lawrence River basin

    SciTech Connect

    Bishop, C.A.; Koster, M.D.; Chek, A.A.; Hussell, D.J.T.; Jock, K.

    1995-03-01

    In 1991, the authors collected red-winged blackbird (Agelauis phoeniceus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings, and sediment samples from 2 wetland sites in the Great lakes and St. Lawrence River basin. They analyzed for chlorinated hydrocarbons and total mercury and found that biota contained contaminant concentrations which were one to two orders of magnitude above those in sediments. Maximum concentrations of contaminants were found in Akwesasne, St. Lawrence river (PCBs = 18,558.8 ng/g in red-winged blackbird eggs, oxychlordane = 58.8/g and mirex = 40.1 ng/g in tree swallow eggs); Mud Creek, Lake Erie and Cootes Paradise. Despite the migratory habits of red-winged blackbirds and tree swallows, agreement among biota and sediment in geographic variation of contaminant concentrations supports the use of these animals as biomonitors of persistent chemicals. Although chlorinated hydrocarbon concentrations in red-winged blackbird eggs were significantly correlated with sediment contamination, the local nature of the tree swallow chick diet suggests that nestlings would be the best indicator of local contaminant trends.

  10. The Reaction Specificity of Nanoparticles in Solution: Application to the Reaction of Nanoparticulate Iron and Iron-Bimetallic Compounds with Chlorinated Hydrocarbons and Oxyanions

    SciTech Connect

    2005-06-01

    The prospect for better remediation technologies using nanoparticles of iron, iron oxides, and iron with catalytic metals (i.e., bimetallics) has potentially transformative implications for environmental management of DOE sites across the country. Of particular interest is the potential to avoid undesirable products from the degradation of chlorinated solvents by taking advantage of the potential selectivity of nanoparticles to produce environmentally benign products from CCl{sub 4}. Chlorinated solvents are the most frequently reported subsurface contaminants across the whole DOE complex, and carbon tetrachloride (CCl{sub 4}) is the chlorinated solvent that is of greatest concern at Hanford (U. S. Department Energy 2001). In evaluating technologies that might be used at the site, a critical concern will be that CCl{sub 4} reduction usually occurs predominantly by hydrogenolysis to chloroform (CHCl{sub 3}) and methylene chloride (CH{sub 2}Cl{sub 2}), both of which are nearly as problematic as CCl{sub 4} (National Research Council, 1978). Competing reaction pathways produce the more desirable products carbon monoxide (CO) and/or formate (HCOO{sup -}), and possibly CO{sub 2}, but the proportion of reaction that occurs by these pathways is highly variable. Iron-based metallic and oxide nanoparticles have been shown to have enhanced reactivity towards a variety of chemical species, including chlorinated hydrocarbons and reducible oxyanions. Possibly of greater importance is the ability of nanoparticles to select for specific reaction products, potentially facilitating the formation of more environmentally acceptable products. The purpose of this study is to develop a fundamental understanding of the mechanism responsible for the overall particle reactivity and reaction selectivity of reactive metal and oxide nanoparticles. To achieve this objective the project involves the synthesis (using solution and vacuum synthesis methods) and characterization of well

  11. EVALUATION OF FUSED-SILICA CAPILLARY COLUMNS FOR GC/ECD (GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION) ANALYSIS OF CHLORINATED HYDROCARBONS LISTED IN EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD 8120 (JOURNAL VERSION)

    EPA Science Inventory

    Four mega-bore, one wide-bore, and one narrow-bore fused-silica capillary columns were evaluated for their applicability to the GC/ECD analysis of 22 chlorinated hydrocarbons, some of which are currently targeted by EPA Method 8120. No one column can resolve all 22 compounds. Fou...

  12. Experimental and theoretical studies into the formation of C4-C6 products in partially chlorinated hydrocarbon pyrolysis systems: a probabilistic approach to congener-specific yield predictions.

    PubMed

    McIntosh, Grant J; Russell, Douglas K

    2014-09-25

    This work presents a study of the pyrolytic formation of vinylacetylene and benzene congeners formed from chlorinated hydrocarbon precursors, a complex, multipath polymerization system formed in a monomer-rich environment. (Co-)pyrolyses of dichloro- and trichloroethylene yield a rich array of products, and assuming a single dominant underlying growth mechanism, this (on comparing expected and observed products) allows a number of potentially competing channels to C4 and C6 products to be ruled out. Poor congener/isomer descriptions rule out even-carbon radical routes, and the absence of C3 and C5 products rule out odd-carbon processes. Vinylidenes appear unable to describe the increased reactivity of acetylenes with chlorination noted in our experiments, leaving molecular acetylene dimerization processes and, in C6 systems, the closely related Diels-Alder cyclization as the likely reaction mechanism. The feasibility of these routes is further supported by ab initio calculations. However, some of the most persuasive evidence is provided by congener-specific yield predictions enabled by the construction of a probability tree analogue of kinetic modeling. This approach is relatively quick to construct, provides surprisingly accurate predictions, and may be a very useful tool in screening for important reaction channels in poorly understood congener- or isomer-rich reaction systems. PMID:25225996

  13. A comparison of the concentrations of certain chlorinated hydrocarbons and polychlorinated biphenyls in bone marrow and fat tissue of children and their concentrations in breast milk

    SciTech Connect

    Scheele, J.; Teufel, M.; Niessen, K.H.

    1995-12-31

    Chlorinated hydrocarbon (CHC) and polychlorinated biphenyl (PCB) concentrations in the bone marrow of 57 children were compared with the concentrations in adipose tissue of 50 children and the concentrations in breast milk in the Federal Republic of Germany from 1984 to 1991. The concentrations of hexachlorobenzene (HCB), the dichlorodiphenyl-trichlorethane (DDT)-metabolites, and polychlorinated biphenyl (PCB) congeners no. 138 and no. 153 were increased threefold, while the concentrations of several hexachloro-cyclohexane (HCH)-isomers and PCB congener no. 180 were only increased two fold. Because breast feeding is the primary source of CHC and PCB in toddlers and infants we also compared the concentrations in bone marrow of children with the concentrations in breast milk and found approximately fourfold higher concentrations for the most highly chlorinated PCB congener no. 180, but only threefold higher concentrations for PCB 138 and 153 and the DDT-metabolites. The concentrations of {beta}-HCH and HCB were only slightly higher in bone marrow. 15 refs., 2 figs.

  14. Transformation of chlorinated hydrocarbons using aquocobalamin or coenzyme F{sub 430} in combination with zero-valent iron

    SciTech Connect

    Morra, M.J.; Borek, V.; Koolpe, J.

    2000-06-01

    More effective methods are necessary for the remediation of soils, sediments, and ground waters contaminated with halogenated organic compounds. The authors objective was to determine the feasibility and utility of using a tetrapyrrole-Fe(0) mixture for reductive dehalogenation of synthetic organic contaminants. Aquocobalamin or coenzyme F{sub 430} was combined with Fe(0) in aqueous systems containing either a single chlorinated compound or mixtures of chlorinated compounds, and substrate disappearance was monitored using gas chromatography-mass spectrometry (GC-MS). Zero-valent iron effectively dehalogenated CCl{sub 4} at low to neutral pH values, while increases in CCl{sub 4} dehalogenation resulting from inclusion of tetrapyrrole catalysts along with Fe(0) occurred only at basic pH values. Rates of CCl{sub 4} disappearance increased with additional aquocobalamin, but reached a maximum and decreased at higher aquocobalamin concentrations. overall dehalogenation rates may thus be a function of Fe(0)'s limited reactive surface area. There was a trend for both tetrapyrrole catalysts to promote the disappearance of halogenated compounds in a mixed substrate containing 20 compounds. Studies with five individual substrates likewise showed trends for increased substrate removal with F{sub 430} beyond that for Fe(0) alone. This increase is most important for compounds such as 1,2-dichloroethane and 1,4-dichlorobenzene that are not readily dehalogenated by Fe(0). Chloride concentrations in the reaction mixtures indicated that reductive dehalogenation was the dominant process responsible for substrate disappearance. Use of a combination of aquocobalamin or coenzyme F{sub 430} and Fe(0) may effectively promote dehalogenation, thus producing fewer products and more complete dehalogenation of the target substrates than can be achieved using only one of the abiotic reductants alone.

  15. Bugs digest chlorinated organics

    SciTech Connect

    Not Available

    1993-02-01

    This article describes a new bioreactor that uses a consortium of aerobic bacteria to biodegrade chlorinated aromatic hydrocarbons. Methanotrophic bacteria are cultivated for their MMO enzyme. After the MMO enzyme breaks down the chlorinated organics by oxidation, non-methanotrophic bacteria consume the byproducts. Pilot-scale testing has demonstrated successful treatment of groundwater containing coal-tar constituents, toluene, trichloroethylene, vinyl chlorides, chlorobenzene, and methyl methacrylate from three Superfund sites.

  16. Catalytic systems for processes of oxidative systems for processes of oxidative chlorination of hydrocarbons. Communication 4. X-ray diffraction study of formation of catalysts on various classes of supports

    SciTech Connect

    Solomonik, I.G.; Kurlyandskaya, I.I.; Ashavskaya, G.A.; Yakerson, V.I.

    1986-10-10

    It is usually assumed that the salt component in supported catalysts, which may be in the liquid phase, is physically distributed in the system of micropores and macropores of the support. Chemical interaction with various supports, differing in nature and structure, has been observed in catalysts for the oxidative chlorination of hydrocarbons. In this article the authors present results from an x-ray diffraction study of supported copper-containing salt systems. It is shown that in supported copper chloride catalysts for the oxidative chlorination of hydrocarbons, the salt component interacts with the support (metastable aluminum oxides or an amorphous aluminosilicate), this interaction leading to the formation of a complex multiphase system. The structure of the support influences the crystallization of the excess salt component, resulting in oriented growth of the crystals. On an aluminosilicate support, copper hydroxochlorides are formed selectively, so that they constitute a large part of the supported salt component.

  17. Different behavioral effect dose–response profiles in mice exposed to two-carbon chlorinated hydrocarbons: Influence of structural and physical properties

    SciTech Connect

    Umezu, Toyoshi Shibata, Yasuyuki

    2014-09-01

    The present study aimed to clarify whether dose–response profiles of acute behavioral effects of 1,2-dichloroethane (DCE), 1,1,1-trichloroethane (TCE), trichloroethylene (TRIC), and tetrachloroethylene (PERC) differ. A test battery involving 6 behavioral endpoints was applied to evaluate the effects of DCE, TCE, TRIC, and PERC in male ICR strain mice under the same experimental conditions. The behavioral effect dose–response profiles of these compounds differed. Regression analysis was used to evaluate the relationship between the dose–response profiles and structural and physical properties of the compounds. Dose–response profile differences correlated significantly with differences in specific structural and physical properties. These results suggest that differences in specific structural and physical properties of DCE, TCE, TRIC, and PERC are responsible for differences in behavioral effects that lead to a variety of dose–response profiles. - Highlights: • We examine effects of 4 chlorinated hydrocarbons on 6 behavioral endpoints in mice. • The behavioral effect dose–response profiles for the 4 compounds are different. • We utilize regression analysis to clarify probable causes of the different profiles. • The compound's physicochemical properties probably produce the different profiles.

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

    PubMed

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

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. PMID:25433980

  19. An evaluation of the use of an advanced oxidation process to remove chlorinated hydrocarbons from groundwater at the US Department of Energy Kansas City Plant

    SciTech Connect

    Garland, S.B. II; Peyton, G.R.

    1990-10-01

    The Allied-Signal Aerospace Company currently operates a production facility in Kansas City, Missouri, under contract with the US Department of Energy (DOE). Over the years the operation of the DOE Kansas City Plant has resulted in the contamination of groundwater with chlorinated hydrocarbons, including trichloroethene (TCE). One of the plumes of contaminated groundwater, the underground tank farm (UTF) plume, was selected for remediation with an advanced oxidation process (AOP) consisting of simultaneous treatment by ozone (O{sub 3}), ultraviolet (UV) radiation, and hydrogen peroxide (H{sub 2}O{sub 2}). Since the use of AOPs is relatively new for the removal of organics from groundwater, information on design criteria, costs, performance, and operating experience is not well documented in the literature. Therefore, the Oak Ridge National Laboratory (ORNL) was requested to evaluate the treatment process. This report documents the work performed through FY 1989. The results of the initial year of the evaluations, FY 1988, have been published previously, and the evaluation will continue at least through FY 1990. This report first briefly describes the treatment plant and the mechanisms of the treatment process. Next, the methodology and the results from the evaluation are discussed. Finally, conclusions and recommendations are presented. 8 refs., 14 figs., 16 tabs.

  20. Estimating the in situ sediment-porewater distribution of PAHs and chlorinated aromatic hydrocarbons in anthropogenic impacted sediments

    SciTech Connect

    Hans Peter H. Arp; Gijs D. Breedveld; Gerard Cornelissen

    2009-08-15

    It has become increasingly apparent that the in situ sediment-porewater distribution behavior of organic compounds within anthropogenic impacted sediments is quite diverse, and challenging to generalize. Traditional models based on octanol-water partitioning generally overestimate native porewater concentrations, and modern approaches accounting for multiple carbon fractions, including black carbon, appear sediment specific. To assess the diversity of this sorption behavior, we collected all peer-reviewed total organic carbon (TOC)-normalized in situ sediment-porewater distribution coefficients, K{sub TOC}, for impacted sediments. This entailed several hundreds of data for PAHs, PCBs, PCDD/Fs, and chlorinated benzenes, covering a large variety of sediments, locations, and experimental methods. Compound-specific KTOC could range up to over 3 orders of magnitude. Output from various predictive models for individual carbonaceous phases found in impacted sediments, based on peer-reviewed polyparameter linear free energy relationships (PP-LFERs), Raoult's Law, and the SPARC online-calculator, were tested to see if any of the models could consistently predict literature K{sub TOC} values within a factor of 30 (i.e. about 1.5 orders of magnitude, or half the range of K{sub TOC} values). The Raoult's Law model and coal tar PP-LFER achieved the sought-after accuracy for all tested compound classes, and are recommended for general, regional-scale modeling purposes. As impacted sediment-porewater distribution models are unlikely to get more accurate than this, this review underpins that the only way to accurately obtain accurate porewater concentrations is to measure them directly, and not infer them from sediment concentrations. 86 refs., 2 figs., 3 tabs.

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

    PubMed

    Atashgahi, Siavash; Maphosa, Farai; De Vrieze, Jo; Haest, Pieter Jan; Boon, Nico; Smidt, Hauke; Springael, Dirk; Dejonghe, Winnie

    2014-03-01

    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 provide a sustainable electron source for organohalide respiring bacteria. In this study, wood chips, hay, straw, tree bark and shrimp waste, were assessed for their long term applicability as an electron donor for OHR of cis-dichloroethene (cDCE) and vinyl chloride (VC) in sediment microcosms. The initial release of fermentation products, such as acetate, propionate and butyrate led to the onset of extensive methane production especially in microcosms amended with shrimp waste, straw and hay, while no considerable stimulation of VC dechlorination was obtained in any of the SPOM amended microcosms. However, in the longer term, short chain fatty acids accumulation decreased as well as methanogenesis, whereas high dechlorination rates of VC and cDCE were established with concomitant increase of Dehalococcoides mccartyi and vcrA and bvcA gene numbers both in the sediment and on the SPOMs. A numeric simulation indicated that a capping layer of 40 cm with hay, straw, tree bark or shrimp waste is suffice to reduce the groundwater VC concentration below the threshold level of 5 μg/l before discharging into the Zenne River, Belgium. Of all SPOMs, the persistent colonization of tree bark by D. mccartyi combined with the lowest stimulation of methanogenesis singled out tree bark as a long-term electron donor for OHR of cDCE/VC in bioreactive caps. PMID:23955471

  2. Aqueous chlorination of resorcinol

    USGS Publications Warehouse

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

    1989-01-01

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

  3. Chlorinated hydrocarbons and biomarkers of exposure in wading birds and fish of the Lower Rio Grande Valley, Texas

    USGS Publications Warehouse

    Wainwright, S.E.; Mora, M.A.; Sericano, J.L.; Thomas, P.

    2001-01-01

    During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with

  4. Immunoquantitation and microsomal monooxygenase activities of hepatic cytochromes P4501A and P4502B and chlorinated hydrocarbon contaminant levels in polar bear (Ursus maritimus).

    PubMed

    Letcher, R J; Norstrom, R J; Lin, S; Ramsay, M A; Bandiera, S M

    1996-04-01

    Contamination of the Arctic ecosystem by anthropogenic compounds has resulted in exposure of polar bear (Ursus maritimus) to lipophilic chlorinated hydrocarbon contaminants (CHCs) accumulated through the marine food web. Liver samples were collected from 16 adult male polar bears in the Canadian arctic and subjected to chemical analysis for CHCs and metabolites, determination of alkoxyresorufin O-dealkylase activities, and immunoquantitation of cytochrome P450 (CYP) protein levels. We report on the relationships between the hepatic microsomal levels of immunoreactive CYP1A and CYP2B isozymes, catalytic activities, and hepatic CHC and metabolite concentrations in polar bear. We specifically explored the influence of several CHCs on the induction of hepatic CYP in polar bear and the potential use of immunoassay quantitation as a bioindicator of CHC exposure. Polychlorinated biphenyls (PCB) classed as CYP1A and mixed CYP1A/CYP2B inducers accounted for about 25% of the total PCB residues present (18,680 +/- 5053 ng/g lipid). CYP1A protein content correlated strongly with hepatic levels of PCBs, PCDDs (0.032 +/- 0.018 ng/g lipid, and PCDFs (0.011 +/- 0.007 ng/g lipid) and their corresponding toxic equivalents (TEQ, 0.377 +/- 0.182 ng/g lipid). Mono-ortho-CB-156, CB-157, and CB-105 were the predominant TEQ contributors. Correlations between CYP2B protein content and CHC residue levels in polar bear liver suggested that ortho-chlorine-substituted PCBs and chlordanes were the major contributors to CYP2B induction. CYP1A and CYP2B contents were therefore good indicators of CHC exposure in polar bear liver. Ethoxyresorufin, pentoxyresorufin, and benzyloxyresorufin O-dealkylase activities increased with increasing CYP1A protein content up to protein levels of approximately 5 pmol/mg, suggesting that all three activities were primarily CYP1A-mediated. These results were substantiated by antibody inhibition experiments. In summary, immunoquantitated CYP1A and CYP2B isozymes are

  5. RADIO FREQUENCY ENHANCED DECONTAMINATION OF SOILS CONTAMINATED WITH HALOGENATED HYDROCARBONS

    EPA Science Inventory

    There has been considerable effort in the development of innovative treatment technologies for the clean up of sites containing hazardous wastes such as hydrocarbons and chlorinated hydrocarbons. Typical examples of such waste material are: chlorinated solvents, polychlorinated b...

  6. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect

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

    1992-08-01

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

  7. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect

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

    1992-01-01

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

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

    USGS Publications Warehouse

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

    2007-01-01

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

  9. Chlorine dioxide

    Integrated Risk Information System (IRIS)

    Chlorine dioxide ; CASRN 10049 - 04 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  10. Chlorine cyanide

    Integrated Risk Information System (IRIS)

    Chlorine cyanide ; CASRN 506 - 77 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  11. Development of a solid-phase microextraction-based method for sampling of persistent chlorinated hydrocarbons in an urbanized coastal environment.

    PubMed

    Zeng, Eddy Y; Tsukada, David; Diehl, Dario W

    2004-11-01

    Solid-phase microextraction (SPME) has been used as an in situ sampling technique for a wide range of volatile organic chemicals, but SPME field sampling of nonvolatile organic pollutants has not been reported. This paper describes the development of an SPME-based sampling method employing a poly(dimethylsiloxane) (PDMS)-coated (100-microm thickness) fiber as the sorbent phase. The laboratory-calibrated PDMS-coated fibers were used to construct SPME samplers, and field tests were conducted at three coastal locations off southern California to determine the equilibrium sampling time and compare the efficacy of the SPME samplers with that of an Infiltrex 100 water pumping system (Axys Environmental Systems Ltd., Sidney, British Columbia, Canada). p,p'-DDE and o,p'-DDE were the components consistently detected in the SPME samples among 42 polychlorinated biphenyl congeners and 17 chlorinated pesticidestargeted. SPME samplers deployed attwo locations with moderate and high levels of contamination for 18 and 30 d, respectively, attained statistically identical concentrations of p,p'-DDE and o,p'-DDE. In addition, SPME samplers deployed for 23 and 43 d, respectively, at a location of low contamination also contained statistically identical concentrations of p,p'-DDE. These results indicate that equilibrium could be reached within 18 to 23 d. The concentrations of p,p'-DDE, o,p'-DDE, or p,p'-DDD obtained with the SPME samplers and the Infiltrex 100 system were virtually identical. In particular, two water column concentration profiles of p,p'-DDE and o,p'-DDE acquired by the SPME samplers at a highly contaminated site on the Palos Verdes Shelf overlapped with the profiles obtained by the Infiltrex 100 system in 1997. The field tests not only reveal the advantages of the SPME samplers compared to the Infiltrex 100 system and other integrative passive devices but also indicate the need to improve the sensitivity of the SPME-based sampling technique. PMID:15575294

  12. 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)

    USGS Publications Warehouse

    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.

  13. U. S. EPA’S APPROACH FOR CHLORINATED SOLVENTS

    EPA Science Inventory

    The approach for chlorinated solvents is similar to the approach for petroleum hydrocarbons. However, there are more mechanisms of removal, including reductive dechlorination (biotic or abiotic), dehydrochloroelimination (abiotic), and hydrolysis (biotic or abiotic). As a resul...

  14. Chlorine Clues

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This plot shows that levels of the element chlorine rise dramatically in the deeper rocks lining the walls of the crater dubbed 'Endurance.' The data shown here were taken by the Mars Exploration Rover Opportunity's alpha particle X-ray spectrometer at Endurance and 'Eagle Crater,' the site where Opportunity first landed at Meridiani Planum.

    Opportunity has been inching down the walls of Endurance Crater, investigating distinct layers of rock as it goes for clues to Mars' buried past. The various Endurance layers have been informally labeled 'A' through 'F.' Targets within these layers are listed on the graph along with previous targets from Eagle Crater. All the rocks listed here were observed after they had been drilled by the rover's rock abrasion tool.

    The observations indicate that the elements making up the shallow rock layers of Endurance Crater resemble those of Eagle, while the deeper layers of Endurance possess increasingly higher concentrations of the element chlorine.

    Opportunity will continue to roll deeper into Endurance to see if this puzzling trend continues. Scientists hope the new data will help them figure out how the presence of chlorine fits into the history of water at Endurance Crater.

  15. River sediment (S-37)--a new analytical quality control material ensuring comparability of chlorinated hydrocarbon analysis during an international environmental study in China.

    PubMed

    Gawlik, B M; Martens, D; Henkelmann, B; Schramm, K W; Kettrup, A; Muntau, H

    2000-06-01

    A sediment reference material (S-37) was prepared as analytical quality control material to be used within an international project on polychlorinated hydrocarbon analysis in two Chinese rivers. The raw material was sampled during a cruise on Yangtse River and transported afterwards to the JRC Ispra for further processing. The material was treated according to the general principles applicable for candidate reference material production. After a thorough homogeneity study of the bulk the material was bottled. A total of 1,080 bottles each containing 50 g of dry sediment powder was obtained. Final homogeneity and stability testing proved the material to be fit for the purpose. Isotope dilution GC/MS was used to establish target values for pentachlorobenzene (1.17 +/- 0.08 ng/g), hexachlorobenzene (3.60 +/- 0.17 ng/g), octachlorostyrene (0.19 +/- 0.01 ng/g), pentachloroanisole (0.52 +/- 0.02 ng/g), alpha-HCH (0.70 +/- 0.05 ng/g), beta-HCH (1.38 +/- 0.18 ng/g), gamma-HCH (0.83 +/- 038 ng/g), 2,4'-DDT (0.36 +/- 0.04 ng/g), 2,4'-DDE (0.29 +/- 0.02 ng/g), 2,4'-DDD (0.49 +/- 0.02), 4,4'-DDT (3.42 +/- 0.47 ng/g), 4,4'-DDD (1.29 +/- 0.17 ng/g), PCB 28 (0.11 +/- 0.01 ng/g), PCB 52 (0.09 +/- 0.003 ng/g), PCB 101 (0.07 +/- 0.003 ng/g), PCB 138 (0.06 +/- 0.003 ng/g) and PCB 153 (0.06 +/- 0.003 ng/g). Furthermore, indicative values for major and minor constituents as well as for polychlorinated dibenzodioxines and -furanes were measured. PMID:11227450

  16. ELECTROCHEMICAL DEGRADATION OF CHLORINATED CONTAMINANTS IN SEDIMENTS AND GROUNDWATER

    EPA Science Inventory

    Chlorinated aliphatic and aromatic compounds account for much of the contamination found at sediments sites. Chlorinated aliphatic hydrocarbons such as trichloroethylene (TCE) occur as serious contaminants at 358 major hazardous waste sites in the USA. TCE is widely used as a sol...

  17. ENZYME-BASED DETECTION OF CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Recent advances in immobilized enzyme-based analytical methods, e.g., the cholinesterase-based water monitor 'CAM' (cholinesterase antagonsist monitor), have proved useful in the detection of organophosphate and carbamate pesticides. This work has now been extended to the detecti...

  18. Hydrocarbon pneumonia

    MedlinePlus

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

  19. REVIEW OF CHLORINATED PHENOLS

    EPA Science Inventory

    The chlorinated phenols are a group of 19 isomers composed of phenol with substituted chlorines. These chemicals are readily soluble in organic solvents but only slightly soluble in water, except for the chlorophenate salts. Chlorophenols with less than 3 chlorines are not used e...

  20. The Chlorination Quandary

    ERIC Educational Resources Information Center

    Josephson, Julian

    1978-01-01

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

  1. Atomic scale insights on chlorinated gamma-alumina surfaces.

    PubMed

    Digne, Mathieu; Raybaud, Pascal; Sautet, Philippe; Guillaume, Denis; Toulhoat, Hervé

    2008-08-20

    The thermochemistry of chlorinated gamma-alumina surfaces is explored by means of density functional calculations as a function of relevant reaction conditions used in experiments and in high-octane fuel production in the refining industry such as hydrocarbon isomerization and reforming. The role of chlorine as a dope of the Brønsted acidity of gamma-alumina surfaces is investigated at an atomic scale. Combining infrared spectroscopy and density functional theory calculations, the most favorable location of chlorine atoms on the (110), (100) and (111) surfaces of gamma-alumina is found to result either from direct adsorption or from the exchange of basic hydroxyl groups. Moreover, the modification of the hydrogen bond network upon chlorine adsorption is put forward as a key parameter for changing the Brønsted acidity. In a second step, we use a thermodynamic approach based on DFT total energy calculations corrected by the chemical potentials of HCl and H2O to determine the adsorption isotherms of chlorine and the relative surface concentration of hydroxyl groups and chlorine species on the gamma-alumina surfaces. The determination of chlorine content as a function of temperature and partial pressures of H2O and HCl offers new quantitative data required for optimizing the state of the support surface in industrial conditions. The mechanisms of chlorination are also discussed as a function of reaction conditions. PMID:18646849

  2. Development of compound-specific isotope analysis of stable chlorine in sub-µmol quantities of chlorinated organic substances

    NASA Astrophysics Data System (ADS)

    Holmstrand, H.; Andersson, P.; Gustafsson, O.

    2003-04-01

    Chlorinated hydrocarbons is a common class of substances known to be of high ecotoxicity largely due to their persistence and strongly lipophilic properties. This group of chemicals include the semivolatile compounds dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCB), which, together with solvents like trichloroethylene (TCE) and perchloroethylene (PCE), are globally present at detectable levels in all natural environments. Recent reports on the possibility of enzymatic synthesis of chlorinated dioxins and furans, illustrate the need for means to distinguish the naturally produced contribution from anthropogenic input to the environment. Shifts in the chlorine isotope composition due to degradation, or synthesis, of a compound are in the order of a few per mil of the initial isotope ratio. The cause of the kinetic isotope effect (KIE) arises from differences in preferential phase distribution of isotopic species. Compound specific isotope analysis (CSIA) of stable chlorine should accordingly provide knowledge relevant to degradation rates, distribution patterns and reaction pathways for organochlorines. Isotope analysis of chlorine, derived from chlorinated hydrocarbons, can be performed using thermal ionisation mass spectrometry (TIMS) with positive ions. This lowers the limit of determination from about 30 μmol Cl for conventional electron ionisation mass spectrometry (EIMS), to less than 0.3 μmol Cl with a precision of 0.25 ppm (1s) for TIMS. Such a decrease by a factor 100 in the requirements of sample size will enable CSIA of sediment samples collected away from the immediate vicinity of strongly contaminated areas. The aim of this study is to develop a functioning sequence for i) sealed tube combustion with CuO of solid phase chlorinated hydrocarbons equivalent to <0.7 μmol Cl, ii) conversion of formed chloride to CsCl by ion exchange chromatography and iii) analysis of chlorine isotopes in TIMS. The described method can open new

  3. Water Treatment Technology - Chlorination.

    ERIC Educational Resources Information Center

    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…

  4. Inhalation of chlorine gas.

    PubMed

    Williams, J G

    1997-11-01

    The clinical features of acute chlorine gas inhalation, and its management are reviewed. Current medical views on the chronic effects of an acute overwhelming exposure on lung function (reactive airways dysfunction syndrome), and the more controversial field of lung disease secondary to repeated inhalations of lower concentrations of chlorine gas are discussed. PMID:9519180

  5. Laboratory experiments to assess the importance of photochemical transformation during the atmospheric transport of chlorinated aromatic pollutants

    SciTech Connect

    Bunce, N.J.; Landers, J.P.; Langshaw, J.A.; Nakai, J.S. )

    1987-01-01

    Chlorinated aromatic hydrocarbons are widespread and persistent pollutants. The EPA priority pollutant list (1978) mentions chlorobenzene, the three dichlorobenzenes, 1, 2, 4-trichlorobenzenes, hexachlorobenzene, and the polyclorinated biophenyls (PCB's) as examples of priority pollutants. In addition to the many studies of the biological chemistry of these chlorinated hydrocarbons, there have also been numerous photochemical studies. The justification for these photochemical studies has been that because these chlorinated hydrocarbons absorb light in the region of the solar spectrum (although very inefficiently) there may be a chance that sunlight assisted degradation is one of the routes by which these substances disappear from the environment. The authors discuss the validity of this possibility in this paper.

  6. TECHNICAL PROTOCOL FOR EVALUATING NATURAL ATTENUATION OF CHLORINATED SOLVENTS IN GROUND WATER

    EPA Science Inventory

    This Protocol is designed to evaluate the fate in ground water of chlorinated aliphatic hydrocarbons and/or fuel hydrocarbons. Documentation of natural attenuation requires detailed site characterization. The data collected under this protocol can be used to compare the relati...

  7. Evaluation of the Tenax trap in the Sample Analysis at Mars instrument suite on the Curiosity rover as a potential hydrocarbon source for chlorinated organics detected in Gale Crater

    NASA Astrophysics Data System (ADS)

    Miller, Kristen E.; Kotrc, Benjamin; Summons, Roger E.; Belmahdi, Imene; Buch, Arnaud; Eigenbrode, Jennifer L.; Freissinet, Caroline; Glavin, Daniel P.; Szopa, Cyril

    2015-08-01

    The Sample Analysis at Mars (SAM) instrument suite aboard Curiosity has detected chlorinated organic compounds in Martian sediment samples. The chlorine in these molecules is thought to derive from oxychlorine salts in Martian sediments, but the carbon source remains under investigation. To constrain possible carbon sources, we investigated how the composition and concentration of oxychlorine phases in solid samples affect organic molecules released from the Tenax traps on board SAM. We created Mars analogue soils by spiking olivine sand with calcium perchlorate, magnesium perchlorate, or ferric iron chloride and analyzed the volatiles generated during pyrolysis-gas chromatography-mass spectrometry using commercial instruments operated under SAM-like conditions, with and without a Tenax trap. Benzoic acid, phthalic anhydride, high molecular weight aromatics, and chlorobenzenes are produced from the trap in response to volatiles released during Cl salt pyrolysis. Changes in composition or concentration of oxychlorine phases between samples could thus potentially produce an increase in chlorobenzene, as observed between samples from Rocknest and Cumberland. However, in our experiments benzoic acid, phthalic anhydride, and chlorobenzenes increase in proportion with the amount of HCl sent to the trap, while in Cumberland samples the chlorobenzene increase showed no corresponding increase in HCl. Based on our experiments, the Tenax trap is a possible source of the traces of chlorobenzene observed at Rocknest, John Klein, and Confidence Hills. The order-of-magnitude higher chlorobenzene abundances observed at Cumberland cannot be attributed to the Tenax trap. Furthermore, we found no evidence of significant trap degradation after hundreds of experiments with Cl salt-containing analogue soils.

  8. CHLORINATED SOLVENT PLUME CONTROL

    EPA Science Inventory

    This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE).

  9. Breathing with chlorinated solvents

    SciTech Connect

    McCarty, P.L.

    1997-06-06

    Chlorinated solvents are effective cleaners and in the past dirted solvents were dumped into landfills, stored in tanks that often leaked, or spilled. As a result the most common contaminants of organic groundwater at hazardous waste sites are the two major chlorinated solvents - tetrachloroethylene (PCE) and trichloroethylene (TCE). Both are suspected carcinogens and both are highly resistant to biodegradation. Now however, there is a report of a bacterium that can remove all of the chlorine atoms from both by halorespiration to form ethene, an innocuous end product. This article goes on to discuss the background of biodegradation of chlorinated compounds, why it is so difficult, and what the future is in this area. 9 refs., 1 fig.

  10. A LONG-LIFE, LOW-COST SORBENT FOR THE CONVERSION OF HCL TO CHLORINE - PHASE II

    EPA Science Inventory

    The U.S. demand for chlorinated hydrocarbons exceeds 15 million tons annually. The production of these chemicals requires elemental chlorine and unavoidably produces HCl as a byproduct (35 to 50% of input Cl2). A consortium of major chemical companies is developing a sor...

  11. Chlorinated degreasing solvents: Physical-chemical properties affecting aquifer contamination and remediation

    SciTech Connect

    Jackson, R.E.; Dwarakanath, V.

    1999-09-30

    Chlorinated degreasing solvents are multicomponent liquids containing not only the chlorinated hydrocarbons with which their name is associated (e.g., trichloroethylene or [TCE], perchloroethylene or [PCE], 1,1,1-trichloroethane [TCA]) but also a number of organic additives included as corrosion inhibitors and antioxidants. The additives, such as 1,4-dioxane, are likely to be of significant public-health importance as ground water contaminants due to their toxicity, solubility, and mobility. Following their use in vapor degreasing systems by industry, chlorinated degreasing solvents will also contain about 25% solubilized oil and grease. A number of physical-chemical properties become especially important in the light of the multicomponent nature of these solvents. First, the higher aqueous solubility and lower sorption of the additives makes it reasonable to expect that faster moving plumes of these solvent additives will precede plumes of the chlorinated hydrocarbons. Second, due to high losses of chlorinated hydrocarbons by volatilization from vapor degreasers during years in the middle of the century, it is probable that background concentrations of these hydrocarbons are present in ground water flow systems due to their downwind washout. Finally, the solubilized oil and grease may cause profound changes to the wettability of aquifer materials contacted by the solvents during their subsurface migration. It is argued, therefore, that the wettability of aquifer materials contaminated by chlorinated degreasing solvents needs to be experimentally determined before remediation of DNAPL at each site, rather than being simply assumed as water wet.

  12. Review of chlorinated phenols

    SciTech Connect

    Exon, J.H.

    1984-12-01

    The chlorinated phenols are a group of 19 isomers composed of phenol with substituted chlorines. These chemicals are readily soluble in organic solvents but only slightly soluble in water, except for the chlorophenate salts. Chlorophenols with less than 3 chlorines are not used extensively except in the production of higher chlorophenols and chlorophenyloxyacetic acid herbicides. Pentachlorophenol and some tetrachlorophenols are used worldwide, primarily as wood preservatives or fungicides. Residues of chlorophenols have been found worldwide in soil, water and air samples, in food products, and in human and animal tissues and body fluids. Environmental contamination with these chemicals occurs from industrial effluents, agricultural runoff, breakdown of chlorophenyloxyacetic acid herbicides and hexachlorobenzene, and from spontaneous formation following chlorination of water for disinfection and deodorization. The acute toxicity of these chemicals is relatively low and little is known concerning their chronic effects. Chlorophenols have not been shown conclusively to be mutagens, teratogens or carcinogens. However, these compounds may act as promotors or cocarcinogens and the immune system is particularly sensitive to their toxic effects. Transplacental exposure to chlorophenols may result in embryotoxicity and abortion. The major mode of toxic action is as uncouplers of oxidative phosphorylation. The toxicity of chlorophenols decreases with decreasing chlorination. These chemicals are mild hepatotoxins and are stored mainly in hepatic and renal tissues.

  13. Spatial and temporal variability of inorganic chlorine in Northwestern Europe

    NASA Astrophysics Data System (ADS)

    Sommariva, R.; Hollis, L. D. J.; Baker, A. R.; Ball, S. M.; Bell, T. G.; Cordell, R. L.; Fleming, Z.; Gaget, M.; Yang, M. X.; Monks, P. S.

    2015-12-01

    Chlorine is well known to be a strong oxidant in the atmosphere;chlorine reactivity impacts the formation of tropospheric ozone, theoxidation of methane and non-methane hydrocarbons, and the cycling ofnitrogen, sulphur and mercury. An accurate assessment of the roleplayed by chlorine in tropospheric chemical processes is complicatedby the scarce knowledge of its sources, sinks and distribution.We report observations of inorganic chlorine species (Cl2, ClNO2,particulate chloride) taken over the period 2014-2015 at threedifferent locations in Britain: an urban site a hundred kilometersfrom the ocean (Leicester), a coastal site mostly affected by shiptraffic (Penlee Point, Cornwall) and a coastal site experiencingeither clean air from the North Sea or polluted air from inland(Weybourne, Norfolk).This dataset provides a first look into the geographical distributionand seasonal variability of chlorine in Northwestern Europe: theresults suggest that, during the night, ClNO2 is ubiquitous withconcentrations in the range of hundreds to thousands of pptV at alllocations, whereas Cl2 can be observed only at coastal sites, withconcentrations of a few tens of pptV. The implications of thewidespread presence of these forms of inorganic chlorine for ozoneproduction and, in general, for the oxidative processes in the loweratmosphere are discussed with the help of a wide range of supportingmeasurements.

  14. Bioremediation of chlorinated solvents and diesel soils

    SciTech Connect

    Huismann, S.S.; Peterson, M.A.; Jardine, R.J.

    1995-11-01

    The US Army, in a cooperative effort with the Tennessee Valley Authority (TVA) and its cooperator, ENSR, performed an innovative enhanced bioremediation project at Fort Gillem in Atlanta, Georgia. The objective of the project was to remediate six hundred cubic yards of soil affected by a mixture of chlorinated compounds and petroleum hydrocarbons which posed a threat to uppermost groundwater and private drinking water wells. ENSR completed a demonstration project to measure the effects of bioremediation on both chlorinated compounds (primarily TCE) and petroleum hydrocarbons ({number_sign}2 diesel). Contaminated soil was placed on top of a bermed polyethylene liner to construct an ex-situ biovault. Nutrients were added to the soil as it was loaded onto the liner. Contaminated soil was also used to construct a control vault. A methane barrier cover was placed over both piles. The cover was designed to prevent short circuiting of induced airflow in and around the enhanced pile, and to prevent the release of fugitive emissions from either pile.

  15. Chlorine: state of the art.

    PubMed

    Evans, Richard B

    2005-01-01

    Chlorine is a widely used industrial chemical. Individuals can be exposed to chlorine through transportation accidents, industrial exposures or misuse of domestic cleaners. While most exposed individuals recover normal pulmonary function, chlorine can cause a variety of lung injuries including pulmonary edema, restrictive lung disease, and obstructive disease, including Reactive Airways Dysfunction Syndrome. Residual effects of chlorine exposure are a function of intensity of exposure, minute ventilation during exposure, and host characteristics such as cigarette smoking and atopy. This monograph will summarize uses of chlorine, the potential for accidents, the mechanism of chlorine toxicity in the lung, and review acute and chronic effects of chlorine exposure on the lung, as well as systemic effects of massive chlorine exposure. PMID:16078037

  16. Hydrodesulfurization of chlorinized coal

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Rohatgi, N. K. (Inventor)

    1983-01-01

    A method of desulfurization is described in which high sulfur coals are desulfurized by low temperature chlorinolysis of coal in liquid media, preferably water, followed by hydrodesulfurization at a temperature above 500 C. The coals are desulfurized to an extent of up to 90% by weight and simultaneously dechlorinated to a chlorine content below 0.1% by weight. The product coals have lower volatiles loss, lower oxygen and nitrogen content and higher fixed carbon than raw coals treated with hydrogen under the same conditions. Heating the chlorinated coal to a temperature above 500 C. in inert gas such as nitrogen results in significantly less desulfurization.

  17. Reaction products of chlorine dioxide.

    PubMed Central

    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

  18. Chlorination of lanthanum oxide.

    PubMed

    Gaviría, Juan P; Navarro, Lucas G; Bohé, Ana E

    2012-03-01

    The reactive system La(2)O(3)(s)-Cl(2)(g) was studied in the temperature range 260-950 °C. The reaction course was followed by thermogravimetry, and the solids involved were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The results showed that the reaction leads to the formation of solid LaOCl, and for temperatures above 850 °C, the lanthanum oxychloride is chlorinated, producing LaCl(3)(l). The formation of the oxychloride progresses through a nucleation and growth mechanism, and the kinetic analysis showed that at temperatures below 325 °C the system is under chemical control. The influence of diffusive processes on the kinetics of production of LaOCl was evaluated by studying the effect of the reactive gas flow rate, the mass of the sample, and the chlorine diffusion through the boundary layer surrounding the solid sample. The conversion curves were analyzed and fitted according to the Johnson-Mehl-Avrami description, and the reaction order with respect to the chlorine partial pressure was obtained by varying this partial pressure between 10 and 70 kPa. The rate equation was obtained, which includes the influence of the temperature, chlorine partial pressure, and reaction degree. PMID:22280490

  19. Chlorine dioxide and hemodialysis

    SciTech Connect

    Smith, R.P. . 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.

  20. Chlorine Dioxide (Gas)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorine dioxide (ClO2) gas is registered by the U.S. Environmental Protection Agency (EPA) as a sterilant for use in manufacturing, laboratory equipment, medical devices, environmental surfaces, tools and clean rooms. Aqueous ClO2 is registered by the EPA as a surface disinfectant and sanitizer fo...

  1. Influence of Other Contaminants on Natural Attenuation of Chlorinated Solvents

    SciTech Connect

    Kinsall, B.L.; Palumbo, A.V.; Pfiffner, S.M.; Phelps, T.J.; Salpas, P.

    1999-04-19

    Studies at numerous sites have shown high variability in the degradation rates of chlorinated solvents as measured by microcosm studies with 14C labeled contaminants. The ability of nutrient and carbon additions to stimulate degradation can vary widely. Although some of these variations can be related to the structure of the extant microbial community, the presence of other less refractory contaminants may be critical fctors impacting the rate of chlorocarbon mineralization. Relaatively highe rates of TCE degradation have been observed in the DOE K-25 burial grounds with diverse organic loadings as well as in areas that show evidence for hydrocarbon contamination. Similarly, at other sites where there was TCE in the absence of hydrocarbons or other contaminants, the measured degradation rates have often been found to be very low. At various other sites, the intrasite variability in degradation rates appeared to be related to the presence of hydrocarbon contamination. The highest rates were observed at sites with evidence of hydrocarbons. These observations indicated that the viability of natural attenuation as a remediation option for chlorinated solvents might depend in part on the presence co-contaminants such as hydrocarbons or natural matter.

  2. Snapping Turtles (Chelydra serpentina) from Canadian Areas of Concern across the southern Laurentian Great Lakes: Chlorinated and brominated hydrocarbon contaminants and metabolites in relation to circulating concentrations of thyroxine and vitamin A.

    PubMed

    Letcher, Robert J; Lu, Zhe; de Solla, Shane R; Sandau, Courtney D; Fernie, Kimberly J

    2015-11-01

    The metabolites of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), as well as other halogenated phenolic contaminants (HPCs) have been shown to have endocrine-disrupting properties, and have been reported with increasing frequency in the blood of wildlife, and mainly in mammals and birds. However, little is known about the persistence, accumulation and distribution of these contaminants in long-lived freshwater reptiles. In the present study, in addition to a large suite of chlorinated and brominated contaminants, metabolites and HPCs, we assessed and compared hydroxylated (OH) PCBs and OH-PBDEs relative to PCBs and PBDEs, respectively, in the plasma of adult male common snapping turtles (Chelydra serpentina). Blood samples were collected from 62 snapping turtles (2001-2004) at 12 wetland sites between the Detroit River and the St. Lawrence River on the Canadian side of the Laurentian Great Lakes of North America. Turtles were sampled from sites designated as Areas of Concern (AOCs) and from a relatively clean reference site in southern Georgian Bay (Tiny Marsh), Lake Huron. Plasma concentrations of Σ46PCB (10-340 ng/g wet weight (ww)) and Σ28OH-PCB (3-83 ng/g ww) were significantly greater (p<0.05) in turtles from the Turkey Creek and Muddy Creek-Wheatley Harbour sites in Lake Erie compared with the reference site turtles. The HPC, pentachlorophenol (PCP), had a mean concentration of 9.6±1.1 ng/g ww. Of the 28 OH-CB congeners screened for, 4-OH-CB187 (42±7 ng/g ww) was the most concentrated of all HPCs measured. Of the 14 OH-BDE congeners examined, four (4'-OH-BDE17, 3-OH-BDE47, 5-OH-BDE47 and 4'-OH-BDE49) were consistently found in all plasma samples. p,p'-DDE was the most concentrated of the 18 organochlorine pesticides (OCPs) examined. The mean concentrations of circulating total thyroxine (TT4), dehydroretinol and retinol in the plasma of the male snapping turtles regardless of sampling site were 5.4±0.3, 81±4.7 and 291±13

  3. Environmental availability of chlorinated organics, explosives, and metals in soils

    SciTech Connect

    Anderson, W.C.; Loehr, R.C.; Smith, B.P.

    1999-08-01

    Environmental availability is key to defining the extent of remediation required. Nationally recognized experts summarize what is known about the environmental availability of chlorinated organics (Perry McCarty), explosives (Judith Pennington), and metals (Rufus Chaney). It also summarizes the current use of environmental availability to set cleanup goals for petroleum hydrocarbons and identifies essential research needed to expand the knowledge base for environmental availability.

  4. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYPTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. xcystation and mouse infectivity were comparatively evaluated to assess oocyst viability. zone and chlorine dioxide more effectively inactivated oocysts than chlorine an...

  5. Process for converting light alkanes to higher hydrocarbons

    DOEpatents

    Noceti, Richard P.; Taylor, Charles E.

    1988-01-01

    A process is disclosed for the production of aromatic-rich, gasoline boiling range hydrocarbons from the lower alkanes, particularly from methane. The process is carried out in two stages. In the first, alkane is reacted with oxygen and hydrogen chloride over an oxyhydrochlorination catalyst such as copper chloride with minor proportions of potassium chloride and rare earth chloride. This produces an intermediate gaseous mixture containing water and chlorinated alkanes. The chlorinated alkanes are contacted with a crystalline aluminosilicate catalyst in the hydrogen or metal promoted form to produce gasoline range hydrocarbons with a high proportion of aromatics and a small percentage of light hydrocarbons (C.sub.2 -C.sub.4). The light hydrocarbons can be recycled for further processing over the oxyhydrochlorination catalyst.

  6. Influence of chlorine on methane oxidation.

    PubMed

    Chi, Yong; Wang, Bo; Yan, Jianhua; Ni, Mingjiang

    2009-01-01

    Experiments on CH4/Cl2/O2/N2 oxidation were conducted in an atmospheric pressure flow reactor to understand the influence of chlorine on hydrocarbon oxidation in hazardous waste incineration. The reaction temperature varied from 973 to 1273 K and the chlorine to hydrogen mole ratio (Cl/H) of the inlet mixture varied from 0 to 0.44. The species produced in the reaction were measured online with Fourier transform infrared spectroscopy (FT-IR). It was found that the destruction and removal efficiency of CH4 increased with Cl/H mole ratio. Increasing Cl/H favored COCl2 and CO formation and inhibited the CO oxidation process. As Cl/H approached 0.44, the concentrations of CH2Cl2 and CH3Cl first increased, and then declined. Reaction temperature greatly affected the reaction system. Increasing temperatures raised the destruction removal efficiency of CH4 and decreased the concentrations of CH3Cl and CH2Cl2. With a certain ratio of Cl/H, the concentrations of CO and COCl2 first increased and then declined. The CO and COCl2 concentration peak was observed around 1100 K and 1023 K, respectively. When the reaction temperature exceeded 1273 K, carbon in CH4 was mostly converted to CO2. It could be concluded that the presence of chlorine enhanced the destruction of CH4, but resulted in the more toxic incomplete combustion products emission such as COCl2 when the reaction temperature was not high enough. PMID:19999983

  7. 40 CFR 704.45 - Chlorinated terphenyl.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... means the percent by weight of chlorine for each isomer (ortho, meta, and para). (3) Isomeric ratio... chlorinated terphenyl. (4) A description of the isomeric ratio and extent of chlorination of the...

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

    SciTech Connect

    McKaque, A.B.; Reeve, D.W.

    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.

  9. REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE

    EPA Science Inventory

    The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

  10. Tropospheric budget of reactive chlorine

    NASA Astrophysics Data System (ADS)

    Graedel, T. E.; Keene, W. C.

    1995-03-01

    Reactive chlorine in the lower atmosphere (as distinguished from chlorofluorocarbon-derived chlorine in the stratosphere) is important to considerations of precipitation acidity, corrosion, foliar damage, and chemistry of the marine boundary layer. Many of the chlorine-containing gases are difficult to measure, and natural sources appear to dominate anthropogenic sources for some chemical species. As a consequence, no satisfactory budget for reactive chlorine in the lower atmosphere is available. We have reviewed information on sources; source strengths; measurements in gas, aqueous, and aerosol phases; and chemical processes and from those data derive global budgets for nine reactive chlorine species and for reactive chlorine as a whole. The typical background abundance of reactive chlorine in the lower tropospheric is about 1.5 ppbv. The nine species, CH3 Cl, CH3 CCl3, HCl, CHClF2, Cl2* (thought to be HOCl and/or Cl2), CCl2 = CCl2, CH2 Cl2 , COCl2 , and CHCl3, each contribute at least a few percent to that total. The tropospheric reactive chlorine burden of approximately 8.3 Tg Cl is dominated by CH3 Cl (≈45 %) and CH3 CCl3 (≈25 %) and appears to be increasing by several percent per year. By far the most vigorous chlorine cycling appears to occur among seasalt aerosol, HCl, and Cl2*. The principal sources of reactive chlorine are volatilization from seasalt (enhanced by anthropogenically generated reactants), marine algae, volcanoes, and coal combustion (natural sources being thus quite important to the budget). It is anticipated that the concentrations of tropospheric reactive chlorine will continue to increase in the next several decades, particularly near urban areas in the rapidly developing countries.

  11. Chlorine adsorption on Au(111): chlorine overlayer or surface chloride?

    PubMed

    Gao, Weiwei; Baker, Thomas A; Zhou, Ling; Pinnaduwage, Dilini S; Kaxiras, Efthimios; Friend, Cynthia M

    2008-03-19

    We report the first scanning tunneling microscope (STM) investigation, combined with density functional theory calculations, to resolve controversy regarding the bonding and structure of chlorine adsorbed on Au(111). STM experiments are carried out at 120 K to overcome instability caused by mobile species upon chlorine adsorption at room temperature. Chlorine adsorption initially lifts the herringbone reconstruction. At low coverages (<0.33 ML), chlorine binds to the top of Au(111)-(1 x 1) surface and leads to formation of an overlayer with (square root(3) x square root(3))R30 degree structure at 0.33 ML. At higher coverages, packing chlorine into an overlayer structure is no longer favored. Gold atoms incorporate into a complex superlattice of a Au-Cl surface compound. PMID:18290645

  12. Chlorine analysis by diode laser atomic absorption spectrometry.

    PubMed

    Koch, J; Zybin, A; Niemax, K

    2000-04-01

    The general characteristics of Diode Laser Absorption Spectrometry (DLAAS) in low pressure plasmas particularly with respect to the detection of non-metals are comprehensively recapitulated and discussed. Furthermore, a detector, which is based on DLAAS in a microwave-induced low pressure plasma as an alternative technique for halogene-specific analysis of volatile compounds and polymeric matrices is described. The analytical capability of the technique is demonstrated on the chlorine-specific analysis of ablated polymer fragments as well as gas chromatographically separated hydrocarbons. Since the measurements were carried out by means of a balanced-heterodyne detection scheme, different technical noise contributions, such as laser excess and RAM noise could efficiently be suppressed and the registered absorption was limited only by the principal shot noise. Thus, in the case of the polymer analysis a chlorine-specific absolute detection limit of 10 pg could be achieved. Furthermore, fundamental investigations concerning the influence of hydrocarbons on the dissociation capability of the microwave induced plasma were performed. For this purpose, the carbon-, chlorine- and hydrogen-specific stoichiometry of the compounds were empirically determined. Deviations from the expected proportions were found to be insignificant, implying the possibility of internal standardization relative to the response of a reference sample. PMID:12953476

  13. MICROEMULSION FORMATION WITH CHLORINATED HYDROCARBONS OF DIFFERING POLARITY

    EPA Science Inventory

    Winsor Type I (o/w), Type II (w/o), and Type III (middle phase) microemulsions have been produced for water and CC14, water and trichloroethylene (TCE), and water and 1,2-dichlorobenzene (DCB) with anionic surfactants and appropriate electrolytes. ttempts at producing classical p...

  14. PERSISTENCE OF CHLORINATED HYDROCARBON CONTAMINATION IN A CALIFORNIA MARINE ECOSYSTEM

    EPA Science Inventory

    Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, USA) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator ...

  15. Corrosion of aluminum alloys by chlorinated hydrocarbon/methanol mixtures

    NASA Technical Reports Server (NTRS)

    De Forest, W. S.

    1967-01-01

    Laboratory investigations show that water-free mixtures of Freon MF /trichlorofluoromethane/ and methanol vigorously attack aluminum alloys which contain significant amounts of copper. Freon MF alone did not attack the aluminum alloys at room temperature. Pure methanol had only a slight corrosive effect on the alloy.

  16. Biodegradation of chlorinated hydrocarbons in a vapor phase reactor

    SciTech Connect

    Ensley, B.D.

    1992-01-01

    A bench scale gas lift loop reactor was constructed to evaluate the feasibility of trichloroethylene (TCE) degradative microorganisms being used to treat TCE contaminated air. Two different microorganisms were used as biocatalysts in this reactor. After proper operating conditions were established for use of this reactor/biocatalyst combination, both microorganisms could degrade 95% of inlet TCE at air flow rates of up to 3% of the total reactor volume per minute. TCE concentrations of between 300 [mu]g/L (60ppmv) and 3000 [mu]g/L (600 ppmv) were degraded with 95% or better efficiency. Preliminary economic evaluations suggest that bioremediation may be the low cost alternative for treating certain TCE contaminated air streams and field trials of a scaled-up reactor system based on this technology are currently underway.

  17. Assessment of biological effects of chlorinated hydrocarbons in osprey chicks

    USGS Publications Warehouse

    Elliott, J.E.; Wilson, L.K.; Henny, Charles J.; Trudeau, Suzanne F.; Leighton, Frederick A.; Kennedy, Sean W.; Cheng, Kimberly M.

    2001-01-01

    Osprey (Pandion haliaetus) eggs were collected during 1995 and 1996 at seven sites along the Fraser and Columbia River systems of British Columbia, Canada, and Washington and Oregon, USA. Fifty-four eggs were placed into a laboratory incubator. Thirty-eight of the hatched chicks were sacrificed within 24 h. Hatching success did not differ among sites and therefore between treatment and reference areas. Residual yolk sacs of eggs collected downstream of the large bleached-kraft pulp mill at Castlegar contained greater mean concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 2,930 ng/kg lipid) compared with reference sites such as the Nechako River, an upper tributary of the Fraser system (33.7 ng/kg). Total polychlorinated biphenyls (PCBs) in yolk sacs were also higher at Castlegar and in samples from the Columbia River downstream of Portland, Oregon, compared with those from the Nechako River. Concentrations of measured chemicals, including TCDD toxic equivalents (TEQs), total PCBs, p,pa??-dichlorodiphenylethylene (p,pa??-DDE), and other organochlorines were not different in eggs that failed to hatch compared with calculated whole-egg values for hatched eggs. There were significant biochemical responses; a hepatic cytochrome P4501A (CYP1A) cross-reactive protein was detected in all samples tested and correlated positively with ethoxyresorufin o-deethylase (EROD) activity and yolk sac concentrations of TEQs and total PCBs. Tissue concentrations of vitamin A compounds varied among sites and correlated positively with yolk sac concentrations of TEQs and PCBs. Morphological, histological, and other physiological parameters, including chick growth, edema, deformities, and hepatic and renal porphyrin concentrations, neither varied among sites nor showed concentration-related effects.

  18. Chlorinated hydrocarbons in the young of Lake Michigan coho salmon

    USGS Publications Warehouse

    Willford, W.A.; Sills, J.B.; Whealdon, E.W.

    1969-01-01

    Three thousand eyed coho salmon (Oncorhynchus kisutch) eggs from Lake Michigan stock were sent by the Department of Natural Resources to the Fish Control Laboratory, La Crosse, Wis., on January 15, 1969, for use in evaluating candidate fish-cnotrol chemicals.

  19. INVESTIGATION OF THE METABOLISM OF CHLORINATED HYDROCARBONS IN SUBHUMAN SPECIES

    EPA Science Inventory

    The purpose of this research program was to provide metabolic data on four rather common drinking water contaminants. The compounds were 1,2,4-trichlorobenzene (TCB), bromodichloromethane (BDC), bis(2-chloroisopropyl) ether (BCIE) and bis(2-chloroethyl) ether (BCEE). The compound...

  20. PERMEABLE REACTIVE WALL REMEDIATION OF CHLORINATED HYDROCARBONS IN GROUNDWATER

    EPA Science Inventory

    A pilot-scale permeable reactive barrier was installed at Moffett Field in April 1996 and its performance was monitored over the following 16 months on a quarterly basis. The details of this study are described in a technology evaluation report (Battelle, 1998). This document pro...

  1. USING TREES TO REMEDIATE GROUNDWATERS CONTAMINATED WITH CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Phytoremediation has emerged as a treatment alternative that combines the low cost of intrinsic remediation with the more active and adaptable characteristics of conventional remediation. Our lab has shown that fast-growing and deep-rooted hybrid poplar take up and transpire tric...

  2. Apparatus for hydrocarbon extraction

    DOEpatents

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

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

  3. Biological Chlorine Cycling in Arctic Peat Soils

    NASA Astrophysics Data System (ADS)

    Zlamal, J. E.; Raab, T. K.; Lipson, D.

    2014-12-01

    Soils of the Arctic tundra near Barrow, Alaska are waterlogged and anoxic throughout most of the profile due to underlying permafrost. Microbial communities in these soils are adapted for the dominant anaerobic conditions and are capable of a surprising diversity of metabolic pathways. Anaerobic respiration in this environment warrants further study, particularly in the realm of electron cycling involving chlorine, which preliminary data suggest may play an important role in arctic anaerobic soil respiration. For decades, Cl was rarely studied outside of the context of solvent-contaminated sites due to the widely held belief that it is an inert element. However, Cl has increasingly become recognized as a metabolic player in microbial communities and soil cycling processes. Organic chlorinated compounds (Clorg) can be made by various organisms and used metabolically by others, such as serving as electron acceptors for microbes performing organohalide respiration. Sequencing our arctic soil samples has uncovered multiple genera of microorganisms capable of participating in many Cl-cycling processes including organohalide respiration, chlorinated hydrocarbon degradation, and perchlorate reduction. Metagenomic analysis of these soils has revealed genes for key enzymes of Cl-related metabolic processes such as dehalogenases and haloperoxidases, and close matches to genomes of known organohalide respiring microorganisms from the Dehalococcoides, Dechloromonas, Carboxydothermus, and Anaeromyxobacter genera. A TOX-100 Chlorine Analyzer was used to quantify total Cl in arctic soils, and these data were examined further to separate levels of inorganic Cl compounds and Clorg. Levels of Clorg increased with soil organic matter content, although total Cl levels lack this trend. X-ray Absorption Near Edge Structure (XANES) was used to provide information on the structure of Clorg in arctic soils, showing great diversity with Cl bound to both aromatic and alkyl groups

  4. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  5. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  6. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  7. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  8. Zebra mussel mortality with chlorine

    SciTech Connect

    Van Benschoten, J.E.; Jensen, J.N.; Harrington, D.; DeGirolamo, D.J.

    1995-05-01

    The rate of mortality of the zebra mussel in response to chlorine is described by a kinetic model that combines a statistical characterization of mussel mortality with a disinfection-type modeling approach. Parameter estimates were made with nine sets of data from experiments conducted in Niagara River water. From the kinetic model, an operational diagram was constructed that describes the time to 95% mortality as a function of chlorine concentration and temperature. Either the model or the diagram can be used to assist utilities in planning chlorination treatments for controlling zebra mussels.

  9. Leaching of oxidic zinc materials with chlorine and chlorine hydrate

    NASA Astrophysics Data System (ADS)

    Thomas, B. K.; Fray, D. J.

    1981-06-01

    Low grade zinc ores and residues were leached in chlorine water and chlorine hydrate water mixtures. It was found that the rate of leaching Adrar ore and Electric Arc Furnace dust obeyed a shrinking core diffusion model, whereas, the rate of leaching of Turkish ore appeared to be controlled by a surface reaction. In all cases, lead leached with the zinc but the iron oxides remained virtually undissolved.

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

    SciTech Connect

    Gordon, G.; Rosenblatt, A.

    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.

  11. CHLORINATION OF AQUATIC HUMIC SUBSTANCES

    EPA Science Inventory

    This research program was initiated with the overall objective of increasing our understanding of the chemical structures of aquatic humic material and their behavior during chemical oxidation in particular with chlorine. Experimental methods were devised for the isolation of hum...

  12. CHLORINE INACTIVATION OF BACILLUS ENDOSPORES

    EPA Science Inventory

    The possibility of a bioterrorism event resulting in the release of Bacillus anthracis endospores into a drinking water distribution system necessitates research into means by which these endospores can be inactivated. This study was designed to determine the chlorine resistance...

  13. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporiodium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were compareatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlor...

  14. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Ozone, chlorine dioxide, and chloramine are currently popular alternatives to ...

  15. Transformation of iopamidol during chlorination.

    PubMed

    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). PMID:25325766

  16. Application of Chlorine-Assisted Chemical Vapor Deposition of Diamond at Low Temperatures

    NASA Technical Reports Server (NTRS)

    Pan, Chenyu; Altemir, David A.; Margrave, John L.; Hauge, Robert H.

    1994-01-01

    Low temperature deposition of diamond has been achieved by a chlorine-assisted diamond chemical vapor deposition (CA-CVD) process. This method begins with the thermal dissociation of molecular chlorine into atomic chlorine in a resistively heated graphite furnace at temperatures between 1300 and 1500 deg. C. The atomic chlorine, upon mixing, subsequently reacts with molecular hydrogen and hydrocarbons. The rapid exchange reactions between the atomic chlorine, molecular hydrogen, and hydrocarbons give rise to the atomic hydrogen and carbon precursors required for diamond deposition. Homoepitaxial diamond growth on diamond substrates has been studied over the substrate temperature range of 100-950 C. It was found that the diamond growth rates are approximately 0.2 microns/hr in the temperature range between 102 and 300 C and that the growth rates do not decrease significantly with a decrease in substrate temperature. This is unique because the traditional diamond deposition using H2/CH4 systems usually disappears at substrate temperatures below approx. 500 deg. C. This opens up a possible route to the deposition of diamond on low-melting point materials such as aluminum and its alloys.

  17. Cleaning without chlorinated solvents

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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 percent. 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.

  18. Cleaning without chlorinated solvents

    SciTech Connect

    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.

  19. Anaerobic biotransformation of chlorinated alkenes

    SciTech Connect

    Zhuang, P.

    1994-01-01

    Chlorinated alkenes are widely found in contaminated subsurface soil and groundwater. The highly chlorinated alkene (i.e., PCE) is not subject to aerobic biotransformation. The aim of this research was to explore the potential of using anaerobic processes (i.e., denitrification, sulfate-reduction and methanogenesis) for chlorinated alkenes biotransformation. Contaminated soil samples were used throughout this study. Soil microcosms simulating field anoxic conditions with various nutrients amendment, liquid microcosms as well as enrichment liquid cultures were developed to delineate the dechlorination process. The effect of biomass, chlorinated alkenes concentration and site specific conditions (e.g., temperature and pH) on the dechlorination and the primary metabolic process was investigated. The role of sorption and nutritional needs (i.e., electron donor) were also studied. A preliminary study revealed that denitrification was the least affected by low temperatures as compared to sulfate-reduction and methanogenesis. Although dechlorination took place under sequential denitrifying and methanogenic conditions and under sulfate-reducing conditions, further studies concluded that fermentative and methanogenic bacteria were responsible for the observed dechlorination. In most cases, dechlorination of PCE or TCE resulted in the accumulation of cDCE. However, a VC-producing culture was developed from the PCE-contaminated soil. In general, the dechlorination process could be enhanced by increasing electron donor and biomass concentration. At relatively low concentrations, the dechlorination rate was also increased with increasing chlorinated alkene concentration. Dechlorination even proceeded at high chlorinated alkene concentrations when methane production was inhibited. However, as the concentration of the chlorinated alkenes increased, severe toxicity eventually halted the dechlorination process.

  20. Chemistry of combined residual chlorination

    SciTech Connect

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

    1982-01-01

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

  1. Products from laboratory chlorination of fly ash from a municipal incinerator

    SciTech Connect

    Eiceman, G.A.; Rghei, H.O.

    1982-01-01

    Fly ash samples from a municipal incinerator were treated at 200 and 300 /sup 0/C with chlorine gas for 1 h. Changes in composition of organic compounds in the samples were determined by using GC and GC/MS analysis of benzene extracts. Chlorination of fly ash produced a series of highly chlorinated aromatic hydrocarbons including hexachlorobenzene, decachlorobiphenyl, and nonachlorobiphenyl. Tentative identifications are also listed for other compounds with the following proposed molecular formulas: C/sub 7/HOCl/sub 5/, C/sub 6/H/sub 3/O/sub 2/Cl/sub 3/, C/sub 8/Cl/sub 8/, and C/sub 12/H/sub 4/O/sub 3/Cl/sub 6/ (or C/sub 13/H/sub 8/O/sub 2/Cl/sub 6/). Production of some of these compounds is dependent upon chlorination of benzene-soluble-nonvolatile precursor which was present naturally in this fly ash. These results show that fly ash from municipal incinerators may undergo gas phase-particulate reactions under conditions of high temperature with a source of chlorine and that such reactions lead to the production of chlorinated organic compounds at trace concentration levels.

  2. SPME-GC-EC of chlorinated paraffins in water

    SciTech Connect

    Webster, G.R.B.; Sarna, L.P.; Thomas, D.A.

    1995-12-31

    Contamination of aquatic ecosystems with chlorinated organic contaminants is an increasing toxicological problem. Chlorinated paraffins (CPs) are a class of compounds which are used as fire retardants in paints and as high pressure lubricants and are classified as Priority Toxic Substances under the Canadian Environmental Protection Act (CEPA). As the largest group of high molecular weight chlorinated hydrocarbons produced in Western Europe and North America, CPs have recently come under increased regulatory scrutiny in Canada, the USA, and Europe, because of concerns about their environmental persistence, possible adverse effects on terrestrial and aquatic organisms, and potential carcinogenicity to humans. In both the monitoring of such contamination and the determination of the success of remediation methods, straightforward and inexpensive analytical methodology increases the ease of environmental assessment and facilitates regulatory enforcement. CPs have been considered to be incapable of being analyzed by GC. The authors report the solid phase microextraction (SPME) based analysis of CPs by GC using electron capture (EC) detection. Both synthetic C{sub 10} standards and fractionated commercially derived material have been analyzed by this method in water.

  3. Detection of chlorinated aromatic compounds

    DOEpatents

    Ekechukwu, A.A.

    1996-02-06

    A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

  4. Field-usable portable analyzer for chlorinated organic compounds

    SciTech Connect

    Buttner, W.J.; Penrose, W.R.; Stetter, J.R.

    1995-10-01

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

  5. Inactivation of Helicobacter pylori by chlorination.

    PubMed Central

    Johnson, C H; Rice, E W; Reasoner, D J

    1997-01-01

    Three strains of Helicobacter pylori were studied to determine their resistance to chlorination. The organisms were readily inactivated by free chlorine and should therefore be controlled by disinfection practices normally employed in the treatment of drinking water. PMID:9406419

  6. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  7. THE ROLE OF CHLORINE IN DIOXIN FORMATION

    EPA Science Inventory

    There is poor correlation between total chlorine in waste streams and formation of polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/F) during waste combustion. This is because the active chlorine (Cl) species are strongly dependent upon combustion conditions. ...

  8. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  9. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  10. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...