Sample records for tetrachloroethylene

  1. HEALTH ASSESSMENT DOCUMENT FOR TETRACHLOROETHYLENE (PERCHLOROETHYLENE)

    EPA Science Inventory

    Tetrachloroethylene (PERC) is believed to exert its adverse effects upon humans via metabolism by the liver. Concern that PERC is likely to be a human carcinogen is based upon the evidence of the National Cancer Institute bioassay, in which PERC induced a statistically significan...

  2. 40 CFR 721.3560 - Derivative of tetra-chloro-ethy-lene.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Derivative of tetra-chloro-ethy-lene. ...Chemical Substances § 721.3560 Derivative of tetra-chloro-ethy-lene. ...paragraph (a)(2) of this section: Derivative of tetrachloroethylene,...

  3. 40 CFR 721.3560 - Derivative of tetra-chloro-ethy-lene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Derivative of tetra-chloro-ethy-lene. ...Chemical Substances § 721.3560 Derivative of tetra-chloro-ethy-lene. ...paragraph (a)(2) of this section: Derivative of tetrachloroethylene,...

  4. 40 CFR 721.3560 - Derivative of tetra-chloro-ethy-lene.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Derivative of tetra-chloro-ethy-lene. ...Chemical Substances § 721.3560 Derivative of tetra-chloro-ethy-lene. ...paragraph (a)(2) of this section: Derivative of tetrachloroethylene,...

  5. 40 CFR 721.3560 - Derivative of tetra-chloro-ethy-lene.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Derivative of tetra-chloro-ethy-lene. ...Chemical Substances § 721.3560 Derivative of tetra-chloro-ethy-lene. ...paragraph (a)(2) of this section: Derivative of tetrachloroethylene,...

  6. ACUTE TOXICITY OF TETRACHLOROETHYLENE AND TETRACHLOROETHYLENE WITH DIMETHYLFORMAMIDE TO RAINBOW TROUT (SALMO GAIRDNERI)

    EPA Science Inventory

    In this study, two acute toxicity tests were conducted with tetrachloroethylene (TCE) using rainbow trout. DMF was used as an additive in one of the tests and was proportionally diluted with the toxicant. The 96 hr LC50 was 4.99 mg/l in the test without DMF and 5.84 mg/l for DMF ...

  7. Health Assessment Document for Tetrachloroethylene (Perchloroethylene) (Final Report)

    EPA Science Inventory

    Tetrachloroethylene (PCE) is a volatile solvent with important commercial applications. It has been detected in the ambient air of a variety of urban and nonurban areas of the United States. It has less frequently been detected in water but has been monitored generally at levels ...

  8. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    EPA Science Inventory

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product ...

  9. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    EPA Science Inventory

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa and was evaluated in four column experiments. esidual PCE was emplaced by injecting 14 C-labeled PCE into water-saturated soil columns and displacing the free product with water. ...

  10. Surfactant enhanced remediation of soil columns contaminated by residual tetrachloroethylene

    Microsoft Academic Search

    K. D. Pennell; M. Jin; L. M. Abriola; G. A. Pope

    1994-01-01

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting (14)C-labeled PCE into water-saturated soil columns and displacing the free product with water. Miscible displacement experiments were conducted before and after PCE entrapment to determine the influence or residual PCE on column dispersivities. The

  11. Human Health Effects of Tetrachloroethylene: Key Findings and Scientific Issues

    PubMed Central

    Hogan, Karen A.; Scott, Cheryl Siegel; Cooper, Glinda S.; Bale, Ambuja S.; Kopylev, Leonid; Barone, Stanley; Makris, Susan L.; Glenn, Barbara; Subramaniam, Ravi P.; Gwinn, Maureen R.; Dzubow, Rebecca C.; Chiu, Weihsueh A.

    2014-01-01

    Background: The U.S. Environmental Protection Agency (EPA) completed a toxicological review of tetrachloroethylene (perchloroethylene, PCE) in February 2012 in support of the Integrated Risk Information System (IRIS). Objectives: We reviewed key findings and scientific issues regarding the human health effects of PCE described in the U.S. EPA’s Toxicological Review of Tetrachloroethylene (Perchloroethylene). Methods: The updated assessment of PCE synthesized and characterized a substantial database of epidemiological, experimental animal, and mechanistic studies. Key scientific issues were addressed through modeling of PCE toxicokinetics, synthesis of evidence from neurological studies, and analyses of toxicokinetic, mechanistic, and other factors (tumor latency, severity, and background rate) in interpreting experimental animal cancer findings. Considerations in evaluating epidemiological studies included the quality (e.g., specificity) of the exposure assessment methods and other essential design features, and the potential for alternative explanations for observed associations (e.g., bias or confounding). Discussion: Toxicokinetic modeling aided in characterizing the complex metabolism and multiple metabolites that contribute to PCE toxicity. The exposure assessment approach—a key evaluation factor for epidemiological studies of bladder cancer, non-Hodgkin lymphoma, and multiple myeloma—provided suggestive evidence of carcinogenicity. Bioassay data provided conclusive evidence of carcinogenicity in experimental animals. Neurotoxicity was identified as a sensitive noncancer health effect, occurring at low exposures: a conclusion supported by multiple studies. Evidence was integrated from human, experimental animal, and mechanistic data sets in assessing adverse health effects of PCE. Conclusions: PCE is likely to be carcinogenic to humans. Neurotoxicity is a sensitive adverse health effect of PCE. Citation: Guyton KZ, Hogan KA, Scott CS, Cooper GS, Bale AS, Kopylev L, Barone S Jr, Makris SL, Glenn B, Subramaniam RP, Gwinn MR, Dzubow RC, Chiu WA. 2014. Human health effects of tetrachloroethylene: key findings and scientific issues. Environ Health Perspect 122:325–334;?http://dx.doi.org/10.1289/ehp.1307359 PMID:24531164

  12. Systematic Literature Review of Uses and Levels of Occupational Exposure to Tetrachloroethylene

    Microsoft Academic Search

    Laura S. Gold; Anneclaire J. De Roos; Martha Waters; Patricia Stewart

    2008-01-01

    Tetrachloroethylene has been one of the most widely used chlorinated solvents in the United States. This review provides a basis for tetrachloroethylene exposure assessment in population-based case-control studies. We performed literature searches in MEDLINE, TOXLINE, NIOSHTIC, and the NIOSH Health Hazard Evaluation databases using relevant search terms. We calculated weighted arithmetic means from the measurement data and compiled these into

  13. Death due to acute tetrachloroethylene intoxication in a chronic abuser.

    PubMed

    Amadasi, Alberto; Mastroluca, Lavinia; Marasciuolo, Laura; Caligara, Marina; Sironi, Luca; Gentile, Guendalina; Zoja, Riccardo

    2015-05-01

    Volatile substances are used widespread, especially among young people, as a cheap and easily accessible drug. Tetrachloroethylene is one of the solvents exerting effects on the central nervous system with experiences of disinhibition and euphoria. The case presented is that of a 27-year-old female, found dead by her father at home with cotton swabs dipped in the nostrils. She was already known for this type of abuse and previously admitted twice to the hospital for nonfatal acute poisonings. The swabs were still soaked in tetrachloroethylene. Toxicological and histological investigations demonstrated the presence of an overlap between chronic intake of the substance (with high concentrations in sites of accumulation, e.g., the adipose tissue, and contemporary tissue damage, as histologically highlighted) and acute intoxication as final cause of death, with a concentration of 158 mg/L in cardiac blood and 4915 mg/kg in the adipose tissue. No other drugs or medicines were detected in body fluids or tissues, and to our knowledge, this is the highest concentration ever detected in forensic cases. This peculiar case confirms the toxicity of this substance and focuses on the importance of complete histological and toxicological investigations in the distinction between chronic abuse and acute intoxication. PMID:25605280

  14. Dose-excretion relationship in tetrachloroethylene-exposed workers and the effect of tetrachloroethylene co-exposure on trichloroethylene metabolism

    SciTech Connect

    Seiji, K.; Inoue, O.; Jin, C.; Liu, Y.T.; Cai, S.X.; Ohashi, M.; Watanabe, T.; Nakatsuka, H.; Kawai, T.; Ikeda, M. (Tohoku Univ. School of Medicine, Sendai (Japan))

    1989-01-01

    Personal monitoring of 8-hour time-weighted average intensity of exposure with diffuse samplers and analysis of shift-end urine for total trichloro-compounds (TTC) and other metabolites were conducted in two groups of workers in China, one (121 subjects) exposed to tetrachloroethylene (TETRA) alone, and the other (38 subjects) exposed to a mixture of TETRA and trichloroethylene (TRI). Urinalysis was also performed on samples from 103 non-exposed controls. A linear exposure-excretion relationship could be observed in both groups of workers. Comparison of these results with those of Japanese TETRA-workers suggested the presence of ethnic difference in TETRA metabolism. Urinary metabolite levels were markedly lower in the mixed (TETRA + TRI) exposure group as compared to previous findings in a group exposed to TRI alone. The observation indicates that metabolism of TRI is suppressed by the co-exposure to TETRA in humans.

  15. RESPONSE TO ISSUES AND DATA SUBMISSIONS ON THE CARCINOGENICITY OF TETRACHLOROETHYLENE (PERCHLOROETHYLENE)

    EPA Science Inventory

    The scientific debate over the potential carcinogenicity of tetrachloroethylene (perchloroethylene, perc, PCE) spans several years. his document reviews the issues considered by the EPA's Science Advisory Board (SAB) during its review of the Draft Addendum to the Health Assessmen...

  16. SURFACTANT-ENHANCED SOLUBILIZATION OF TETRACHLOROETHYLENE AND DEGRADATION PRODUCTS IN PUMP AND TREAT REMEDIATION

    EPA Science Inventory

    Experiments were conducted to investigate the enhanced solubilization of tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,2-dichloroethylene (DCE) in nonionic surfactant solutions of Triton X-100, Brij-30, Igepal CA-720, and Tergitol NP-10 (alkylpolyoxyethylenes). urfact...

  17. Prenatal and Early Childhood Exposure to Tetrachloroethylene and Adult Vision

    PubMed Central

    Getz, Kelly D.; Janulewicz, Patricia A.; Rowe, Susannah; Weinberg, Janice M.; Winter, Michael R.; Martin, Brett R.; Vieira, Veronica M.; White, Roberta F.

    2012-01-01

    Background: Tetrachloroethylene (PCE; or perchloroethylene) has been implicated in visual impairments among adults with occupational and environmental exposures as well as children born to women with occupational exposure during pregnancy. Objectives: Using a population-based retrospective cohort study, we examined the association between prenatal and early childhood exposure to PCE-contaminated drinking water on Cape Cod, Massachusetts, and deficits in adult color vision and contrast sensitivity. Methods: We estimated the amount of PCE that was delivered to the family residence from participants’ gestation through 5 years of age. We administered to this now adult study population vision tests to assess acuity, contrast sensitivity, and color discrimination. Results: Participants exposed to higher PCE levels exhibited lower contrast sensitivity at intermediate and high spatial frequencies compared with unexposed participants, although the differences were generally not statistically significant. Exposed participants also exhibited poorer color discrimination than unexposed participants. The difference in mean color confusion indices (CCI) was statistically significant for the Farnsworth test but not Lanthony’s D-15d test [Farnsworth CCI mean difference = 0.05, 95% confidence interval (CI): 0.003, 0.10; Lanthony CCI mean difference = 0.07, 95% CI: –0.02, 0.15]. Conclusions: Prenatal and early childhood exposure to PCE-contaminated drinking water may be associated with long-term subclinical visual dysfunction in adulthood, particularly with respect to color discrimination. Further investigation of this association in similarly exposed populations is necessary. PMID:22784657

  18. Indoor tetrachloroethylene levels and determinants in Paris dwellings.

    PubMed

    Roda, Célina; Kousignian, Isabelle; Ramond, Anna; Momas, Isabelle

    2013-01-01

    There is growing public health concern about indoor air quality. Tetrachloroethylene (PERC), a chlorinated volatile organic compound widely used as a solvent in dry cleaning facilities, can be a residential indoor air pollutant. As part of an environmental investigation included in the PARIS (Pollution and asthma Risk: an Infant Study) birth cohort, this study firstly aimed to document domestic PERC levels, and then to identify the factors influencing these levels using standardized questionnaires about housing characteristics and living conditions. Air samples were collected in the child's bedroom over one week using passive devices when infants were 1, 6, 9, and 12 months. PERC was identified and quantified by gas chromatography/mass spectrometry. PERC annual domestic level was calculated by averaging seasonal levels. PERC was omnipresent indoors, annual levels ranged from 0.6 to 124.2 ?g/m3. Multivariate linear and logistic regression models showed that proximity to dry cleaning facilities, do-it-yourself activities (e.g.: photographic development, silverware), presence of air vents, and building construction date (<1945) were responsible for higher domestic levels of PERC. This study, conducted in an urban context, provides helpful information on PERC contamination in dwellings, and identifies parameters influencing this contamination. PMID:23127492

  19. Systematic literature review of uses and levels of occupational exposure to tetrachloroethylene.

    PubMed

    Gold, Laura S; De Roos, Anneclaire J; Waters, Martha; Stewart, Patricia

    2008-12-01

    Tetrachloroethylene has been one of the most widely used chlorinated solvents in the United States. This review provides a basis for tetrachloroethylene exposure assessment in population-based case-control studies. We performed literature searches in MEDLINE, TOXLINE, NIOSHTIC, and the NIOSH Health Hazard Evaluation databases using relevant search terms. We calculated weighted arithmetic means from the measurement data and compiled these into three summary tables by type of operation: (1) dry cleaning, (2) degreasing, and (3) other operations. We identified 258 relevant documents, of which 179 (69%) contained useful descriptive information. Within the dry cleaning industry, the overall arithmetic mean (AM) for personal tetrachloroethylene exposures was 59 ppm (range: 0-4636, n = 1395). Machine operators who transferred wet garments to a dryer had the highest levels (AM = 150 ppm [range: 0-1000, n = 441]) of the jobs in this industry. The AM for personal measurements associated with degreasing was 95 ppm (range: 0-1800, n = 206). In addition, we identified several other sources of substantial tetrachloroethylene exposure, including cleaning mining equipment, testing coal, cleaning animal coats in taxidermy, and cleaning and duplicating film. Exposure assessment in population-based, case-control studies is a complex process requiring substantial resources. Researchers conducting these types of studies will be able to use results of the measurements to quantify tetrachloroethylene exposure levels for various jobs. PMID:18949603

  20. Tetrachloroethylene Exposure and Bladder Cancer Risk: A Meta-Analysis of Dry-Cleaning-Worker Studies

    PubMed Central

    Vlaanderen, Jelle; Straif, Kurt; Ruder, Avima; Blair, Aaron; Hansen, Johnni; Lynge, Elsebeth; Charbotel, Barbara; Loomis, Dana; Kauppinen, Timo; Kyyronen, Pentti; Pukkala, Eero; Weiderpass, Elisabete

    2014-01-01

    Background: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as “probably carcinogenic to humans” based on limited evidence of an increased risk of bladder cancer in dry cleaners. Objectives: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry. Methods: Random-effects meta-analyses were carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure–response data because of the limited number of studies available. Results: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI: 0.82, 1.42; three studies; 463 exposed cases). For employment as a dry cleaner, the overall mRR was 1.47 (95% CI: 1.16, 1.85; seven studies; 139 exposed cases), and for smoking-adjusted studies, the mRR was 1.50 (95% CI: 0.80, 2.84; 4 case–control studies). Conclusions: Our meta-analysis demonstrates an increased risk of bladder cancer in dry cleaners, reported in both cohort and case–control studies, and some evidence for an exposure–response relationship. Although dry cleaners incur mixed exposures, tetrachloroethylene could be responsible for the excess risk of bladder cancer because it is the primary solvent used and it is the only chemical commonly used by dry cleaners that is currently identified as a potential bladder carcinogen. Relatively crude approaches in exposure assessment in the studies of “tetrachloroethylene-exposed workers” may have attenuated the relative risks. Citation: Vlaanderen J, Straif K, Ruder A, Blair A, Hansen J, Lynge E, Charbotel B, Loomis D, Kauppinen T, Kyyronen P, Pukkala E, Weiderpass E, Guha N. 2014. Tetrachloroethylene exposure and bladder cancer risk: a meta-analysis of dry-cleaning-worker studies. Environ Health Perspect 122:661–666;?http://dx.doi.org/10.1289/ehp.1307055 PMID:24659585

  1. Acute and chronic toxicity of some chlorinated benzenes, chlorinated ethanes, and tetrachloroethylene to Daphnia magna

    Microsoft Academic Search

    Joseph E. Richter; Steven F. Peterson; Charles E Kleinert

    1983-01-01

    Chronic effect and no effect concentrations (28 day) and acute toxicity (48 hr, LC50 and EC50) values were determined forDaphnia magna with some chlorinated benzenes, chlorinated ethanes, and tetrachloroethylene. Acute and chronic toxicity generally increased with the degree of chlorine substitution with these chemicals. The 48 hr LC50 values for hexachloroethane, pentachloroethane, 1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane, 1,2-dichloroethane, 1,2,4-trichlorobenzene, 1,3-dichlorobenzene, and tetrachloroethylene were

  2. Kinetics of tetrachloroethylene in volunteers; influence of exposure concentration and work load

    Microsoft Academic Search

    A. C. Monster; G. Boersma; H. Steenweg

    1979-01-01

    Six male volunteers were exposed for 4 h to 72 ppm tetrachloroethylene (PERC) at rest, to 144 ppm PERC at rest, and to 142 ppm PERC at rest combined with work load (2 times 30 min, 100 W). Minute volume and concentrations in exhaled air were measured to estimate the uptake. Concentrations of PERC and trichloroacetic acid (TCA) were determined

  3. SUBCHRONIC TOXICITY OF TETRACHLOROETHYLENE (PERCHLOROETHYLENE) ADMINISTERED IN THE DRINKING WATER OF RATS

    EPA Science Inventory

    The study provides data on the effects of tetrachloroethylene in drinking solutions. The acute oral LD(50) was determined in male and female Charles River rats and found to be 3835 mg/kg for males and 3005 mg/kg for females. Male and female rats received theoretical daily doses o...

  4. ACUTE AND CHRONIC TOXICITY OF SOME CHLORINATED BENZENES, CHLORINATED ETHANES, AND TETRACHLOROETHYLENE TO 'DAPHNIA MAGNA'

    EPA Science Inventory

    Chronic effect and no effect concentrations (28 day) and acute toxicity (48 hr, LC50 and EC50) values were determined for Daphnia magna with some chlorinated benzenes, chlorinated ethanes, and tetrachloroethylene. Acute and chronic toxicity generally increased with the degree of ...

  5. Prenatal Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Adverse Birth Outcomes

    Microsoft Academic Search

    Ann Aschengrau; Janice Weinberg; Sarah Rogers; Lisa Gallagher; Michael Winter; Veronica Vieira; Thomas Webster; David Ozonoff

    2008-01-01

    Background: Prior studies of prenatal exposure to tetrachloroethylene (PCE) have shown mixed results regarding its effect on birth weight and gestational age. Objectives: In this retrospective cohort study we examined whether PCE contamination of public drinking-water supplies in Massachusetts influenced the birth weight and gestational duration of children whose mothers were exposed before the child's delivery. Methods: The study included

  6. EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE (PCE) IN CONTROLLED SPILL EXPERIMENTS

    EPA Science Inventory

    Tetrachloroethylene (PCE), typically used as a dry cleaning solvent, is a predominant contaminant in the subsurface at Superfund Sites. PCE is a dense non-aqueous phase liquid (DNAPL) that migrates downward into the earth, leaving behind areas of residual saturation and free prod...

  7. Continuous Determination of High-Vapor Phase Concentrations of Tetrachloroethylene Using On-Line Mass Spectrometry

    EPA Science Inventory

    A method was developed to determine the vapor concentration of tetrachloroethylene (PCE) at and below its equilibrium vapor phase concentration, 168,000 µg/L (25°C). Vapor samples were drawn by vacuum into a six-port sampling valve and injected through a jet separator into an io...

  8. Photolysis, Sonolysis, and Photosonolysis of Trichloroethane (TCA), Trichloroethylene (TCE), and Tetrachloroethylene (PCE) Without Catalyst

    Microsoft Academic Search

    Chikashi Sato

    2011-01-01

    Photolysis, sonolysis, and photosonolysis of common groundwater contaminants, namely 1,1,1-trichloroethane, trichloroethylene,\\u000a and tetrachloroethylene, were investigated using a flow-through photosono reactor system. Simulated groundwater containing\\u000a the chlorinated volatile organic compounds (VOCs) was exposed to ultraviolet light (UV), ultrasonication (US), and UV and\\u000a US concurrently (UVUS), without a photo catalyst. VOC removal efficiencies of the UV, US, and UVUS treatment processes were

  9. Subchronic toxicity of tetrachloroethylene (perchloroethylene) administered in the drinking water of rats

    SciTech Connect

    Hayes, J.R.; Condie, L.W. Jr.; Borzelleca, J.F.

    1986-07-01

    This study provides data on the effects of tetrachloroethylene in drinking solutions. The acute oral LD50 in male and female Charles River rats was found to be 3835 mg/kg for males and 3005 mg/kg for females. Male and female rats received theoretical daily doses of 14,400, and 1400 mg tetrachloroethylene/kg body wt/day for 90 consecutive days. There were no compound-related deaths. Body weights were significantly lower in male and female rats at the higher doses. There were no consistent dose-related effects on any of the hematological, clinical chemistry, or urinalysis parameters. 5'-Nucleotidase activity was increased in a dose-dependent manner, suggesting possible hepatotoxicity; however, other serum indicators of hepatic function were unaffected by the treatment. There were no gross pathological effects observed. Liver and kidney body weight ratios, but not brain weight ratios, were elevated at the higher doses. There was no other evidence of compound-related toxicity. These data suggest that exposure of humans to reported levels of tetrachloroethylene in drinking water (approximately 1 microgram/liter) does not constitute a serious health hazard.

  10. Use of Mini-Sprinklers to Strip Trichloroethylene and Tetrachloroethylene from Contaminated Ground Water.

    SciTech Connect

    Brerisford, Yvette, C.; Bush, Parshall, B.; Blake, John, I.; Bayer, Cassandra L.

    2003-01-01

    Berisford, Y.C., P.B. Bush, J.I. Blake, and C.L. Bayer. 2003. Use of mini-sprinklers to strip trichloroethylene and tetrachloroethylene from contaminated ground water. J. Env. Qual. 32:801-815. Three low-volume mini-sprinklers were tested for their efficacy to strip trichloroethylene (TCE) and tetrachloroethylene (PCE) from water. Deionized water spiked with TCE and PCE was pumped through a mini-sprinkler supported on top of a 1.8-m-tall. Water was collected in collection vessels at 0.61 and 1.22 m above the ground on support columns that were spaced at 0.61-m intervals from the riser base, and samples were composited per height and distance from the riser. Overall, air-stripping reduced dissolved concentrations of TCE and PCE by 99.1 to 100 and 96.9 to 100%, respectively. Mini-sprinklers offer the advantages of (i) easy setup in series that can be used on practically any terrain; (ii) operation over a long period of time that does not threaten aquifer depletion; (iii) use in small or confined aquifers in which the capacity is too low to support large irrigation or pumping systems; and (iv) use in forests in which the small, low-impact droplets of the mini-sprinklers do not damage bark and in which trees can help manage (via evapotransporation) excess waste water.

  11. ADVANCED OXIDATION PROCESSES FOR TREATING GROUNDWATER CONTAMINATED WITH TCE (TRICHLOROETHYLENE) AND PCE (TETRACHLOROETHYLENE): LABORATORY STUDIES (JOURNAL VERSION)

    EPA Science Inventory

    Oxidation of trichloroethylene (TCE) and tetrachloroethylene (PCE) with various dosages of ozone or ozone plus hydrogen peroxide was studied in laboratory experiments. The results show that hydrogen peroxide accelerates the oxidation of TCE and PCE by ozone. At peroxide-to-ozone ...

  12. Risk of learning and behavioral disorders following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water

    Microsoft Academic Search

    Patricia A. Janulewicz; Roberta F. White; Michael R. Winter; Janice M. Weinberg; Lisa E. Gallagher; Veronica Vieira; Thomas F. Webster; Ann Aschengrau

    2008-01-01

    This population-based retrospective cohort study examined the association between developmental disorders of learning, attention and behavior and prenatal and early postnatal drinking water exposure to tetrachloroethylene (PCE) on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling

  13. Prenatal exposure to tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies: a retrospective cohort study

    Microsoft Academic Search

    Ann Aschengrau; Janice M. Weinberg; Patricia A. Janulewicz; Lisa G. Gallagher; Michael R. Winter; Veronica M. Vieira; Thomas F. Webster; David M. Ozonoff

    2009-01-01

    BACKGROUND: Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. OBJECTIVES: This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception.

  14. SURFACTANT ENHANCED RECOVERY OF TETRACHLOROETHYLENE FROM A POROUS MEDIUM CONTAINING LOW PERMEABILITY LENSES. 1. EXPERIMENTAL STUDIES. (R825409)

    EPA Science Inventory

    Abstract A matrix of batch, column and two-dimensional (2-D) box experiments was conducted to investigate the coupled effects of rate-limited solubilization and layering on the entrapment and subsequent recovery of a representative dense NAPL, tetrachloroethylene (PCE)...

  15. Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Pregnancy Loss

    PubMed Central

    Aschengrau, Ann; Weinberg, Janice M.; Gallagher, Lisa G.; Winter, Michael R.; Vieira, Veronica M.; Webster, Thomas F.; Ozonoff, David M.

    2010-01-01

    There is little information on the impact of solvent-contaminated drinking water on pregnancy outcomes. This retrospective cohort study examined whether maternal exposure to tetrachloroethylene (PCE) - contaminated drinking water in the Cape Cod region of Massachusetts influenced the risk of clinically recognized pregnancy loss. The study identified exposed (n=959) and unexposed (1,087) women who completed a questionnaire on their residential and pregnancy histories, and confounding variables. Exposure was estimated using water distribution system modeling software. No meaningful associations were seen between PCE exposure level and the risk of clinically recognized pregnancy loss at the exposure levels experienced by the study population. Because PCE remains a common water contaminant, it is important to continue monitoring its impact on women and their pregnancies. PMID:20613966

  16. In situ study of tetrachloroethylene bioremediation with different microbial community shifting.

    PubMed

    Bhowmik, Arpita; Asahino, Akane; Shiraki, Takanori; Nakamura, Kohei; Takamizawa, Kazuhiro

    2009-12-14

    In this study, we characterized the microbial community in groundwater contaminated with tetrachloroethylene (PCE) in order to evaluate the intrinsic and enhanced bioremediation of PCE. Variable behaviour of microbes was observed between natural attenuation and biostimulation, where the latter was mediated by the addition of nutrients. Results of denaturing gradient gel electrophoresis (DGGE) of amplified bacterial 16S rDNA in the case of biostimulation showed that the microbial community was dominated by species phylogenetically related to the beta-proteobacteria. With regards to natural attenuation, sequences were found belonging to multiple species of different phyla. Interestingly, we found sequences that matched the species belonging to the Firmicutes, which contains bacteria capable of reductive dehalogenation. These results suggest the possibility of the presence of some Clostridium-like PCE degraders within the microbial community when using bioremediation or biostimulation. PMID:20184006

  17. Difference in uptake, elimination, and metabolism in exposure to trichloroethylene, 1,1,1-trichloroethane and tetrachloroethylene

    Microsoft Academic Search

    A. C. Monster

    1979-01-01

    The relatively high and almost constant absorption\\/min of trichloroethylene (TRI) is explained by the relatively high partition coefficient between blood and air (?b\\/g = 15) combined with the rapid metabolism (75 %). Tetrachloroethylene (PERC) has about the same ?b\\/g as TRI, but the metabolism is insignificant (2 %); therefore, the amount taken up\\/min decreases in the course of exposure. The

  18. A risk-based cleanup criterion for PCE in soil. [Tetrachloroethylene

    SciTech Connect

    Daniels, J.I.; McKone, T.E.; Hall, L.C.

    1990-09-26

    The most important attribute of a chemical contaminant at a hazardous-wastes site for decision makers to consider with regard to its cleanup is the potential risk associated with human exposure. For this reason we have developed a strategy for establishing a risk-based cleanup criterion for chemicals in soil. We describe this strategy by presenting a cleanup criterion for tetrachloroethylene (PCE) in soil associated with a representative California landscape. We being by discussing the environmental fate and transport model, developed at the Lawrence Livermore National Laboratory (LLNL), that we used to predict the equilibrium concentration of PCE in five environmental media from a steady-state source in soil. Next, we explain the concept and application of pathway-exposure factors (PEFs), the hazard index, and cancer-potency factors (CPFs) for translating the predicted concentrations of PCE into estimated potential hazard or risk for hypothetically exposed individuals. Finally, the relationship between concentration and an allowable level of risk is defined and the societal and financial implications are discussed. 22 refs., 6 tabs.

  19. Kinetics of tetrachloroethylene-reductive dechlorination catalyzed by vitamin B{sub 12}

    SciTech Connect

    Burris, D.R. [AFRL/MLQR, Tyndall AFB, FL (United States); Delcomyn, C.A. [Applied Research Associates, Inc., Tyndall AFB, FL (United States); Deng, B. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Mineral and Environmental Engineering; Buck, L.E. [Polytechnic Univ., Brooklyn, NY (United States). Dept. of Civil and Environmental Engineering; Hatfield, K. [Univ. of Florida, Gainesville, FL (United States). Dept. of Civil Engineering

    1998-09-01

    Reductive dechlorination kinetics of tetrachloroethylene (PCE) to ethylene catalyzed by vitamin B{sub 12} using Ti[III] citrate as the bulk reductant was examined in a vapor-water batch system. A kinetic model incorporating substrate-B{sub 12} electron-transfer complex formation and subsequent product release was developed. The model also accounted for the primary reductive dechlorination pathways (hydrogenolysis and reductive {beta} elimination) and vapor/water-phase partitioning. Reaction rate constants were sequentially determined by fitting the model to experimental kinetic data while moving upward through consecutive reaction pathways. The release of product from the complex was found to be second order with respect to substrate concentration for both PCE and acetylene; all other substrates appeared to release by first order. Reductive {beta} elimination was found to be a significant reaction pathway for trichloroethylene (TCE), and chloroacetylene was observed as a reactive intermediate. Acetylene production appears to be primarily due to the reduction of chloroacetylene derived from TCE. The reduction of cis-dichloroethylene (cis-DCE), the primary DCE isomer formed, was extremely slow, leading to a significant buildup of cis-DCE. The kinetics of acetylene and vinyl chloride reduction appeared to be limited by the formation of relatively stable substrate-B{sub 12} complexes. The relatively simple model examined appears to adequately represent the main features of the experimental data.

  20. Adult neuropsychological performance following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water.

    PubMed

    Janulewicz, Patricia A; White, Roberta F; Martin, Brett M; Winter, Michael R; Weinberg, Janice M; Vieira, Veronica; Aschengrau, Ann

    2012-01-01

    This population-based retrospective cohort study examined adult performance on a battery of neuropsychological tests in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Results of crude and multivariate analyses among 35 exposed and 28 unexposed subjects showed no association between prenatal and early postnatal exposure and decrements on tests that assess abilities in the domains of omnibus intelligence, academic achievement or language. The results were suggestive of an association between prenatal and early postnatal PCE exposure and diminished performance on tests that assessed abilities in the domains of visuospatial functioning, learning and memory, motor, attention and mood. Because the sample size was small, most findings were not statistically significant. Future studies with larger sample sizes should be conducted to further define the neuropsychological consequences of early developmental PCE exposure. PMID:22522125

  1. Adult Neuropsychological Performance Following Prenatal and Early Postnatal Exposure to Tetrachloroethylene (PCE)-contaminated Drinking Water

    PubMed Central

    Janulewicz, Patricia A; White, Roberta F; Martin, Brett M; Winter, Michael R; Weinberg, Janice M; Vieira, Veronica; Aschengrau, Ann

    2012-01-01

    This population-based retrospective cohort study examined adult performance on a battery of neuropsychological tests in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Results of crude and multivariate analyses among 35 exposed and 28 unexposed subjects showed no association between prenatal and early postnatal exposure and decrements on tests that assess abilities in the domains of omnibus intelligence, academic achievement or language. The results were suggestive of an association between prenatal and early postnatal PCE exposure and diminished performance on tests that assessed abilities in the domains of visuospatial functioning, learning and memory, motor, attention and mood. Because the sample size was small, most findings were not statistically significant. Future studies with larger sample sizes should be conducted to further define the neuropsychological consequences of early developmental PCE exposure. PMID:22522125

  2. THE EFFECT OF LOW CONCENTRATIONS OF TETRACHLOROETHYLENE ON THE PERFORMANCE OF PEM FUEL CELLS

    SciTech Connect

    COLON-MERCHADO, H.; MARTINEZ-RODRIGUEZ, M.; FOX, E.; RHODES, W.; MCWHORTER, C.; GREENWAY, S.

    2011-04-18

    Polymer electrolyte membrane (PEM) fuel cells use components that are susceptible to contaminants in the fuel stream. To ensure fuel quality, standards are being set to regulate the amount of impurities allowable in fuel. The present study investigates the effect of chlorinated impurities on fuel cell systems using tetrachloroethylene (PCE) as a model compound for cleaning and degreasing agents. Concentrations between 0.05 parts per million (ppm) and 30 ppm were studied. We show how PCE causes rapid drop in cell performances for all concentrations including 0.05 ppm. At concentrations of 1 and 0.05 ppm, PCE poisoned the cell at a rate dependent on the dosage of the contaminant delivered to the cell. PCE appears to affect the cell when the cell potential was over potentials higher than approximately 0.2 V. No effects were observed at voltages around or below 0.2 V and the cells could be recovered from previous poisoning performed at higher potentials. Recoveries at those low voltages could be induced by changing the operating voltage or by purging the system. Poisoning did not appear to affect the membrane conductivity. Measurements with long-path length IR results suggested catalytic decomposition of the PCE by hydrogen over the anode catalyst.

  3. Prenatal Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Adverse Birth Outcomes

    PubMed Central

    Aschengrau, Ann; Weinberg, Janice; Rogers, Sarah; Gallagher, Lisa; Winter, Michael; Vieira, Veronica; Webster, Thomas; Ozonoff, David

    2008-01-01

    Background Prior studies of prenatal exposure to tetrachloroethylene (PCE) have shown mixed results regarding its effect on birth weight and gestational age. Objectives In this retrospective cohort study we examined whether PCE contamination of public drinking-water supplies in Massachusetts influenced the birth weight and gestational duration of children whose mothers were exposed before the child’s delivery. Methods The study included 1,353 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 772 children of unexposed mothers. Birth records were used to identify subjects and provide information on the outcomes. Mothers completed a questionnaire to gather information on residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results We found no meaningful associations between PCE exposure and birth weight or gestational duration. Compared with children whose mothers were unexposed during the year of the last menstrual period (LMP), adjusted mean differences in birth weight were 20.9, 6.2, 30.1, and 15.2 g for children whose mothers’ average monthly exposure during the LMP year ranged from the lowest to highest quartile. Similarly, compared with unexposed children, adjusted mean differences in gestational age were ?0.2, 0.1, ?0.1, and ?0.2 weeks for children whose mothers’ average monthly exposure ranged from the lowest to highest quartile. Similar results were observed for two other measures of prenatal exposure. Conclusions These results suggest that prenatal PCE exposure does not have an adverse effect on these birth outcomes at the exposure levels experienced by this population. PMID:18560539

  4. Toxicity of a Solvent Mixture of 1,1,1-TrichIoroethane and Tetrachloroethylene as Determined by Experiments on Laboratory Animals and Human Subjects

    Microsoft Academic Search

    V. K. Rowe; T. Wujkowski; M. A. Wolf; S. E. Sadek; R. D. Stewart

    1963-01-01

    The toxicological properties of a solvent mixture (Dowclenef EC cleaner) consisting by weight of 75% inhibited 1,1,1-trichloroethane (Chlorothene NU solvent) and 25% tetrachloroethylene were studied on rats, mice, guinea pigs, rabbits, dogs and human subjects. The material was low in oral toxicity, not appreciably irritating to the eyes or skin, not absorbed through the skin to an appreciable extent, and

  5. Apartment residents' and day care workers' exposures to tetrachloroethylene and deficits in visual contrast sensitivity.

    PubMed Central

    Schreiber, Judith S; Hudnell, H Kenneth; Geller, Andrew M; House, Dennis E; Aldous, Kenneth M; Force, Michael S; Langguth, Karyn; Prohonic, Elizabeth J; Parker, Jean C

    2002-01-01

    Tetrachloroethylene (also called perchloroethylene, or perc), a volatile organic compound, has been the predominant solvent used by the dry-cleaning industry for many years. The U.S. Environmental Protection Agency (EPA) classified perc as a hazardous air pollutant because of its potential adverse impact on human health. Several occupational studies have indicated that chronic, airborne perc exposure adversely affects neurobehavioral functions in workers, particularly visual color discrimination and tasks dependent on rapid visual-information processing. A 1995 study by Altmann and colleagues extended these findings, indicating that environmental perc exposure at a mean level of 4,980 microg/m(3) (median=1,360 microg/m(3)) alters neurobehavioral functions in residents living near dry-cleaning facilities. Although the U.S. EPA has not yet set a reference concentration guideline level for environmental exposure to airborne perc, the New York State Department of Health set an air quality guideline of 100 microg/m(3). In the current residential study, we investigated the potential for perc exposure and neurologic effects, using a battery of visual-system function tests, among healthy members of six families living in two apartment buildings in New York City that contained dry-cleaning facilities on the ground floors. In addition, a day care investigation assessed the potential for perc exposure and effects among workers at a day care center located in the same one-story building as a dry-cleaning facility. Results from the residential study showed a mean exposure level of 778 microg/m(3) perc in indoor air for a mean of 5.8 years, and that perc levels in breath, blood, and urine were 1-2 orders of magnitude in excess of background values. Group-mean visual contrast sensitivity (VCS), a measure of the ability to detect visual patterns, was significantly reduced in the 17 exposed study participants relative to unexposed matched-control participants. The groups did not differ in visual acuity, suggesting that the VCS deficit was of neurologic origin. Healthy workers in the day care investigation were chronically exposed to airborne perc at a mean of 2,150 microg/m(3) for a mean of 4.0 years. Again, group-mean VCS, measured 6 weeks after exposure cessation, was significantly reduced in the nine exposed workers relative to matched controls, and the groups did not differ significantly in visual acuity. These results suggested that chronic, environmental exposure to airborne perc adversely affects neurobehavioral function in healthy individuals. Further research is needed to assess the susceptibility of the young and elderly to perc-induced effects, to determine whether persistent solvent-induced VCS deficits are a risk factor for the development of neurologic disease, and to identify the no observable adverse effect level for chronic, environmental, perc exposure in humans. PMID:12117642

  6. Interfacial Properties of a Hydrophobic Dye in the Tetrachloroethylene-Water-Glass Systems

    SciTech Connect

    Tuck, D.M.

    1999-02-23

    Interfacial effects play an important role in governing multiphase fluid behavior in porous media. Strongly hydrophobic organic dyes, used in many experimental studies to facilitate visual observation of the phase distributions, have generally been implicitly assumed to have no influence on the interfacial properties of the various phases in porous media. Sudan IV is the most commonly used dye for non-aqueous phase liquids (NAPLs) in laboratory experiments. It has also been used in at least one field experiment. The effects of this dye on the tetrachloroethylene (PCE)-water-glass system were investigated to test the assumption that the dye does not effect the interfacial properties and therefore PCE mobility. The results indicate that the dye does indeed change the interfacial relationships.The effect of the dye on the interfacial relationships is a complex function of the dye concentration, the solid phase composition, and the dynamic rate of new interface formation. The dye caused a slight (<10 percent) increase in interfacial tension at low concentrations (<0.1 g/L) and high rates of new interface formation. The dye reduced interfacial tension between PCE and water at low rates of new interface formation for all dye concentrations tested (0.00508 to 5.08 g/L). At the highest dye concentration, the PCE-water interfacial tension was significantly reduced regardless of the rate of new interface formation. The apparent interfacial tension increase at low dye concentrations is suspected to be an artifact of a low measured IFT value for the undyed PCE caused by leaching of rubber o-rings by the PCE prior to testing in the final drop-volume configuration.In addition to reducing interfacial tension, the dye was found to significantly alter the wetting relationship between PCE and water on a glass surface at and above the range of reported dye concentrations cited in the literature (1.1 to 1.7 g/L). The wetting relationship was rendered neutral from a water-wet initial condition at the highest dye concentration. The contact angle, measured through the aqueous phase, changed from 58 degrees for undyed PCE to 93 degrees at a dye concentration of 5.08 g/L. Complete reversal of the wettability is likely given the short equilibration time used in this study (approximately five minutes) together with literature indications that hundreds to thousands of hours may be required to reach equilibrium during contact angle measurements. Observations suggesting changing wetting relationships were also noted between PCE, water, and the platinum-iridium surface used in the standard du No/374y ring method for measuring interfacial tension.Observations of the dyed-PCE-water interface behavior during du No/374y ring interfacial tension measurements were similar to observations noted previously during measurements of the interfacial tension between the Savannah River Site (SRS) M-Area Settling Basin DNAPL (M-Area DNAPL) and water. This observation suggests that the M-Area DNAPL may contain surface active components. If this proves to be the case, it would have significant implications for how the M-Area DNAPL is distributed and moves in the SRS subsurface.

  7. Excess molar volumes of 2-(2-alkoxyethoxy)ethanols with trichloroethylene and tetrachloroethylene at 298.15 and 308.15 K

    Microsoft Academic Search

    Amalendu Pal; Wazir Singh

    1995-01-01

    The excess molar volumes for binary liquid mixtures of trichloroethylene, CâClâH and tetrachloroethylene, CâClâ, with 2-(2-methoxyethoxy)ethanol, CHâO(CHâ)âO(CHâ)âOH, 2-(2-ethoxyethoxy)ethanol, CâHâO(CHâ)âO(CHâ)âOH, and 2-(2-butoxyethoxy)ethanol, CâHâO(CHâ)âO(CHâ)âOH, have been measured using a continuous-dilution dilatometer over the entire mole fraction range at 298.15 and 308.15 K. The excess volumes change sign for trichloroethylene and are positive for tetrachloroethylene with 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, and 2-(2-butoxyethoxy)ethanol over the whole

  8. Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment

    Microsoft Academic Search

    Lisa G Gallagher; Veronica M Vieira; David Ozonoff; Thomas F Webster; Ann Aschengrau

    2011-01-01

    Background  Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking\\u000a water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood\\u000a of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of\\u000a breast cancer among women

  9. Remediation of an aquifer polluted with dissolved tetrachloroethylene by an array of wells filled with activated carbon.

    PubMed

    Bortone, I; Di Nardo, A; Di Natale, M; Erto, A; Musmarra, D; Santonastaso, G F

    2013-09-15

    In this work, an array of deep passive wells filled with activated carbon, namely a Discontinuous Permeable Adsorptive Barrier (PAB-D), has been proposed for the remediation of an aquifer contaminated by tetrachloroethylene (PCE). The dynamics of the aquifer in the particular PAB-D configuration chosen, including the contaminant transport in the aquifer and the adsorption onto the barrier material, has been accurately performed by means of a computer code which allows describing all the phenomena occurring in the aquifer, simultaneously. A PAB-D design procedure is presented and the main dimensions of the barrier (number and position of passive wells) have been evaluated. Numerical simulations have been carried out over a long time span to follow the contaminant plume and to assess the effectiveness of the remediation method proposed. The model results show that this PAB-D design allows for a complete remediation of the aquifer under a natural hydraulic gradient, the PCE concentrations flowing out of the barrier being always lower than the corresponding Italian regulation limit. Finally, the results have been compared with those obtained for the design of a more traditional continuous barrier (PAB-C) for the same remediation process. PMID:23876256

  10. Risk of learning and behavioral disorders following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water.

    PubMed

    Janulewicz, Patricia A; White, Roberta F; Winter, Michael R; Weinberg, Janice M; Gallagher, Lisa E; Vieira, Veronica; Webster, Thomas F; Aschengrau, Ann

    2008-01-01

    This population-based retrospective cohort study examined the association between developmental disorders of learning, attention and behavior and prenatal and early postnatal drinking water exposure to tetrachloroethylene (PCE) on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Mothers completed a questionnaire on disorders of attention, learning and behavior in their children and on potential confounding variables. The final cohort consisted of 2086 children. Results of crude and multivariate analyses showed no association between prenatal exposure and receiving tutoring for reading or math, being placed on an Individual Education Plan, or repeating a school grade (adjusted Odds Ratios (OR)=1.0-1.2). There was also no consistent pattern of increased risk for receiving a diagnosis of Attention Deficit Disorder (ADD) or Hyperactive Disorder (HD), special class placement for academic or behavioral problems, or lower educational attainment. Modest associations were observed for the latter outcomes only in the low exposure group (e.g., adjusted ORs for ADD were 1.4 and 1.0 for low and high exposure, respectively). (All ORs are based on an unexposed referent group.) Results for postnatal exposure through age five years were similar to those for prenatal exposure. We conclude that prenatal and early postnatal PCE exposure is not associated with disorders of attention, learning and behavior identified on the basis of questionnaire responses and at the exposure levels experienced by this population. PMID:18353612

  11. Prenatal exposure to tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies: a retrospective cohort study

    PubMed Central

    2009-01-01

    Background Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. Objectives This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception. Methods The study included 1,658 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 2,999 children of unexposed mothers. Mothers completed a self-administered questionnaire to gather information on all of their prior births, including the presence of anomalies, residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results Children whose mothers had high exposure levels around the time of conception had an increased risk of congenital anomalies. The adjusted odds ratio of all anomalies combined among children with prenatal exposure in the uppermost quartile was 1.5 (95% CI: 0.9, 2.5). No meaningful increases in the risk were seen for lower exposure levels. Increases were also observed in the risk of neural tube defects (OR: 3.5, 95% CI: 0.8, 14.0) and oral clefts (OR 3.2, 95% CI: 0.7, 15.0) among offspring with any prenatal exposure. Conclusion The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who are identified by independent records. PMID:19778411

  12. Risk of Learning and Behavioral Disorders Following Prenatal and Early Postnatal Exposure to Tetrachloroethylene (PCE)-contaminated Drinking Water

    PubMed Central

    Janulewicz, Patricia A; White, Roberta F; Winter, Michael R; Weinberg, Janice M; Gallagher, Lisa E; Vieira, Veronica; Webster, Thomas F; Aschengrau, Ann

    2008-01-01

    This population-based retrospective cohort study examined the association between developmental disorders of learning, attention and behavior and prenatal and early postnatal drinking water exposure to tetrachloroethylene (PCE) on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Mothers completed a questionnaire on disorders of attention, learning and behavior in their children and on potential confounding variables. The final cohort consisted of 2,086 children. Results of crude and multivariate analyses showed no association between prenatal exposure and receiving tutoring for reading or math, being placed on an Individual Education Plan, or repeating a school grade (adjusted Odds Ratios (OR)=1.0–1.2). There was also no consistent pattern of increased risk for receiving a diagnosis of Attention Deficit Disorder (ADD) or Hyperactive Disorder (HD), special class placement for academic or behavioral problems, or lower educational attainment. Modest associations were observed for the latter outcomes only in the low exposure group (e.g., adjusted ORs for ADD were 1.4 and 1.0 for low and high exposure, respectively). (All ORs are based on an unexposed referent group.) Results for postnatal exposure through age five years were similar to those for prenatal exposure. We conclude that prenatal and early postnatal PCE exposure is not associated with disorders of attention, learning and behavior identified on the basis of questionnaire responses and at the exposure levels experienced by this population. PMID:18353612

  13. Potential of physiologically based pharmacokinetics to amalgamate kinetic data of trichloroethylene and tetrachloroethylene obtained in rats and man.

    PubMed Central

    Koizumi, A

    1989-01-01

    A physiologically based pharmacokinetic model was used to amalgamate information obtained in rats and man by various routes of exposure to trichloroethylene (TRI) and tetrachloroethylene (TETRA). Since there have been no pharmacokinetic data on drinking water exposure, drinking water exposure to TRI was conducted in rats using 14C-TRI. Several partition coefficients of TRI and TETRA were also determined in the present study. Simulations of the kinetics of TRI and TETRA were made with the unified physiologically based pharmacokinetic model to determine whether reported pharmacokinetic data from different routes of exposure to TRI and TETRA (inhalation, intravenous, drinking water in rats, and inhalation in man) could be simulated. The results indicated that the unified model used in this study successfully simulates the pharmacokinetics of TRI and TETRA irrespective of the routes and exposure intensities. Subsequently, sensitivity analyses were performed. Since both TRI and TETRA require bioactivation to produce their toxicity, the amounts metabolised in the body were used as indicators of toxicity. Vmax (maximum velocity of metabolism in the liver), alveolar ventilation, and the blood/air partition coefficient had a more profound effect than other factors on the amounts of these chemicals metabolised when parameter values were altered. The model was applied to simulate the biologically permissible values of exhaled air concentration and blood concentration of these compounds for monitoring exposure intensities in occupational settings. The simulated maximum permissible values showed good agreement with those obtained by field studies. Finally, the model was applied to the risk assessment of drinking water exposures to TRI and TETRA, assuming that a man weighing 70 kg drinks 2 l of the most contaminated drinking water ever reported in the US; 32 ppb for TRI and 5 ppb for TETRA. The simulated metabolised amounts of TRI and TETRA under steady state condition in man were a fifth of an order of magnitude lower than non-cancer causing metabolised amounts of TRI and TETRA in rats through inhalation. PMID:2713280

  14. Adverse Birth Outcomes and Maternal Exposure to Trichloroethylene and Tetrachloroethylene through Soil Vapor Intrusion in New York State

    PubMed Central

    Lewis-Michl, Elizabeth L.; Gomez, Marta I.

    2011-01-01

    Background: Industrial spills of volatile organic compounds (VOCs) in Endicott, New York (USA), have led to contamination of groundwater, soil, and soil gas. Previous studies have reported an increase in adverse birth outcomes among women exposed to VOCs in drinking water. Objective: We investigated the prevalence of adverse birth outcomes among mothers exposed to trichloroethylene (TCE) and tetrachloroethylene [or perchloroethylene (PCE)] in indoor air contaminated through soil vapor intrusion. Methods: We examined low birth weight (LBW), preterm birth, fetal growth restriction, and birth defects among births to women in Endicott who were exposed to VOCs, compared with births statewide. We used Poisson regression to analyze births and malformations to estimate the association between maternal exposure to VOCs adjusting for sex, mother’s age, race, education, parity, and prenatal care. Two exposure areas were identified based on environmental sampling data: one area was primarily contaminated with TCE, and the other with PCE. Results: In the TCE-contaminated area, adjusted rate ratios (RRs) were significantly elevated for LBW [RR = 1.36; 95% confidence interval (CI): 1.07, 1.73; n = 76], small for gestational age (RR = 1.23; 95% CI: 1.03, 1.48; n = 117), term LBW (RR = 1.68; 95% CI: 1.20, 2.34; n = 37), cardiac defects (RR = 2.15; 95% CI: 1.27, 3.62; n = 15), and conotruncal defects (RR = 4.91; 95% CI: 1.58, 15.24; n = 3). In the PCE-contaminated area, RRs for cardiac defects (five births) were elevated but not significantly. Residual socioeconomic confounding may have contributed to elevations of LBW outcomes. Conclusions: Maternal residence in both areas was associated with cardiac defects. Residence in the TCE area, but not the PCE area, was associated with LBW and fetal growth restriction. PMID:22142966

  15. Tetrachloroethylene-contaminated drinking water in Massachusetts and the risk of colon-rectum, lung, and other cancers.

    PubMed Central

    Paulu, C; Aschengrau, A; Ozonoff, D

    1999-01-01

    We conducted a population-based case-control study to evaluate the relationship between cancer of the colon-rectum (n = 326), lung (n = 252), brain (n = 37), and pancreas (n = 37), and exposure to tetrachloroethylene (PCE) from public drinking water. Subjects were exposed to PCE when it leached from the vinyl lining of drinking-water distribution pipes. Relative delivered dose of PCE was estimated using a model that took into account residential location, years of residence, water flow, and pipe characteristics. Adjusted odds ratios (ORs) for lung cancer were moderately elevated among subjects whose exposure level was above the 90th percentile whether or not a latent period was assumed [ORs and 95% confidence intervals (CIs), 3.7 (1.0-11.7), 3.3 (0.6-13.4), 6.2 (1.1-31.6), and 19.3 (2.5-141.7) for 0, 5, 7, and 9 years of latency, respectively]. The adjusted ORs for colon-rectum cancer were modestly elevated among ever-exposed subjects as more years of latency were assumed [OR and CI, 1.7 (0.8-3.8) and 2.0 (0.6-5.8) for 11 and 13 years of latency, respectively]. These elevated ORs stemmed mainly from associations with rectal cancer. Adjusted ORs for rectal cancer among ever-exposed subjects were more elevated [OR and CI, 2.6 (0. 8-6.7) and 3.1 (0.7-10.9) for 11 and 13 years of latency, respectively] than were corresponding estimates for colon cancer [OR and CI, 1.3 (0.5-3.5) and 1.5 (0.3-5.8) for 11 and 13 years of latency, respectively]. These results provide evidence for an association between PCE-contaminated public drinking water and cancer of the lung and, possibly, cancer of the colon-rectum. PMID:10090704

  16. Spatiotemporal variability of tetrachloroethylene in residential indoor air due to vapor intrusion: a longitudinal, community-based study.

    PubMed

    Johnston, Jill E; Gibson, Jacqueline MacDonald

    2014-11-01

    The migration of volatile contaminants from groundwater and soil into indoor air is a potential health threat at thousands of contaminated sites across the country. This phenomenon, known as vapor intrusion, is characterized by spatial and temporal heterogeneity. This study examined short-term fluctuations in concentrations of tetrachloroethylene (PCE) in the indoor air of residential homes due to vapor intrusion in a community in San Antonio, Texas, that sits atop an extensive, shallow plume of contaminated groundwater. Using a community-based design, we removed potential indoor sources of PCE and then collected twelve 3-day passive indoor air samples in each of the 20 homes. Results demonstrated a one-order-of-magnitude variability in concentration across both space and time among the study homes, although all measured concentrations were below risk-based screening levels. We found that within any given home, indoor concentrations increase with the magnitude of the barometric pressure drop (P=0.048) and humidity (P<0.001), while concentrations decrease as wind speed increases (P<0.001) and also during winter (P=0.001). In a second analysis to examine sources of spatial variability, we found that indoor air PCE concentrations between homes increase with groundwater concentration (P=0.030) and a slab-on-grade (as compared with a crawl space) foundation (P=0.028), whereas concentrations decrease in homes without air conditioners (P=0.015). This study offers insights into the drivers of temporal and spatial variability in vapor intrusion that can inform decisions regarding monitoring and exposure assessment at affected sites. PMID:23549403

  17. Influence of heat treatment conditions on the physicochemical and catalytic properties of a chromium-containing catalyst for tetrachloroethylene hydrofluorination to pentafluoroethane

    Microsoft Academic Search

    L. G. Simonova; A. A. Zirka; S. I. Reshetnikov; T. V. Larina; G. S. Litvak; L. G. Pinaeva; L. A. Isupova

    2011-01-01

    The physicochemical properties of coprecipitated 95% Cr2O3-5% Al2O3 oxide systems obtained by heat treatment of the precursor in nitrogen and air between 110 and 600°C and their influence on\\u000a the catalytic activity in tetrachloroethylene hydrofluorination were studied by thermal and X-ray diffraction analyses, diffuse\\u000a reflectance spectroscopy, and specific surface are measurements. The CrO1.9 compounds are more active than CrO1.5, but

  18. Treatment of tetrachloroethylene-contaminated groundwater by surfactant-enhanced persulfate/BOF slag oxidation--a laboratory feasibility study.

    PubMed

    Tsai, T T; Kao, C M; Hong, A

    2009-11-15

    The main objective of this study was to evaluate the feasibility of remediating tetrachloroethylene (PCE)-contaminated groundwater (with initial PCE concentration of approximately 20 mg L(-1)) via persulfate oxidation activated by basic oxygen furnace slag (S(2)O(8)(2-)/BOF slag) with the addition of biodegradable surfactant (Tween 80). Results indicate that only 15% of PCE can be removed in experiment with the addition of S(2)O(8)(2-) only (S(2)O(8)(2-)/PCE=30/1). PCE removal can be increased to 31% while both S(2)O(8)(2-) and BOF slag (10 g L(-1)) were added. This indicates that BOF slag was able to activate the persulfate oxidation mechanism, and cause the decrease in PCE concentration via oxidation process. Results also reveal that PCE degradation rates increased to 92% with the presence of Tween 80 (S(2)O(8)(2-)/Tween 80/PCE=30/2/1). In the presence of 10 g L(-1) BOF slag, the reaction rate constant (k(obs)) values were found to be 3.1 x 10(-3), 8.7 x 10(-3), 1.6 x 10(-2), and 5.8 x 10(-2)h(-1), as the S(2)O(8)(2-)/Tween 80/PCE molar ratios were 30/0/1, 30/0.5/1, 30/1/1, and 30/2/1, respectively. The reaction rate constant increased as the Tween 80 concentration increased. The significantly increased k(obs) could be caused by the enhanced solubilization of PCE by Tween 80. The increase in initial surfactant concentration would cause the increase in the solubilization of PCE, and thus, enhance the oxidation rate. This was confirmed by the total amount of chloride ions produced after the reaction. Results from this study indicate that BOF slag-activated persulfate oxidation enhanced by surfactant addition is a potential method to efficiently and effectively remediate chlorinated solvents contaminated groundwater. PMID:19586715

  19. Distributions and sea-to-air fluxes of chloroform, trichloroethylene, tetrachloroethylene, chlorodibromomethane and bromoform in the Yellow Sea and the East China Sea during spring.

    PubMed

    He, Zhen; Yang, Gui-Peng; Lu, Xiao-Lan; Zhang, Hong-Hai

    2013-06-01

    Halocarbons including chloroform (CHCl3), trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4), chlorodibromomethane (CHBr2Cl) and bromoform (CHBr3) were measured in the Yellow Sea (YS) and the East China Sea (ECS) during spring 2011. The influences of chlorophyll a, salinity and nutrients on the distributions of these gases were examined. Elevated levels of these gases in the coastal waters were attributed to anthropogenic inputs and biological release by phytoplankton. The vertical distributions of these gases in the water column were controlled by different source strengths and water masses. Using atmospheric concentrations measured in spring 2012 and seawater concentrations obtained from this study, the sea-to-air fluxes of these gases were estimated. Our results showed that the emissions of C2HCl3, C2Cl4, CHBr2Cl, and CHBr3 from the study area could account for 16.5%, 10.5%, 14.6%, and 3.5% of global oceanic emissions, respectively, indicating that the coastal shelf may contribute significantly to the global oceanic emissions of these gases. PMID:23466729

  20. Structural Magnetic Resonance Imaging in an adult cohort following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water.

    PubMed

    Janulewicz, Patricia A; Killiany, Ronald J; White, Roberta F; Martin, Brett M; Winter, Michael R; Weinberg, Janice M; Aschengrau, Ann

    2013-01-01

    This population-based retrospective cohort study examined Structural Magnetic Resonance Imaging (MRI) of the brain in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and Geographic Information System (GIS) methodology. Brain imaging was performed on 26 exposed and 16 unexposed subjects. Scans were acquired on a Philips 3T whole body scanner using the ADNI T1-weighted MP-RAGE scan. The scans were processed by FreeSurfer version 4.3.1 software to obtain measurements of specific brain regions. There were no statistically significant differences between exposed and unexposed subjects on the measures of white matter hypointensities (?: 127.5mm(3), 95% CI: -259.1, 1514.0), white matter volumes (e.g. total cerebral white matter: ?: 21230.0mm(3), 95% CI: -4512.6, 46971.7) or gray matter volumes (e.g. total cerebral gray matter: ?: 11976.0mm(3), 95% CI: -13657.2, 37609.3). The results of this study suggest that exposure to PCE during gestation and early childhood, at the levels observed in this population, is not associated with alterations in the brain structures studied. PMID:23571160

  1. Structural Magnetic Resonance Imaging in an Adult Cohort Following Prenatal and Early Postnatal Exposure to Tetrachloroethylene (PCE)-contaminated Drinking Water

    PubMed Central

    Janulewicz, Patricia A; Killiany, Ronald J; White, Roberta F; Martin, Brett M; Winter, Michael R; Weinberg, Janice M; Aschengrau, Ann

    2013-01-01

    This population-based retrospective cohort study examined Structural Magnetic Resonance Imaging (MRI) of the brain in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and Geographic Information System (GIS) methodology. Brain imaging was performed on 26 exposed and 16 unexposed subjects. Scans were acquired on a Philips 3T whole body scanner using the ADNI T1-weighted MP-RAGE scan. The scans were processed by FreeSurfer version 4.3.1 software to obtain measurements of specific brain regions. There were no statistically significant differences between exposed and unexposed subjects on measures of white matter hypointensities (?: 127.5 mm3, 95% CI: ?259.1, 1514.0), white matter volumes (e.g. total cerebral white matter: ?: 21230.0 mm3, 95% CI: ?4512.6, 46971.7) or gray matter volumes (e.g. total cerebral gray matter: ?: 11976.0 mm3, 95% CI: ?13657.2, 37609.3). The results of this study suggest that exposure to PCE during gestation and early childhood, at the levels observed in this population, is not associated with alterations in the brain structures studied. PMID:23571160

  2. Occurrence of mental illness following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

    PubMed Central

    2012-01-01

    Background While many studies of adults with solvent exposure have shown increased risks of anxiety and depressive disorders, there is little information on the impact of prenatal and early childhood exposure on the subsequent risk of mental illness. This retrospective cohort study examined whether early life exposure to tetrachloroethylene (PCE)-contaminated drinking water influenced the occurrence of depression, bipolar disorder, post-traumatic stress disorder, and schizophrenia among adults from Cape Cod, Massachusetts. Methods A total of 1,512 subjects born between 1969 and 1983 were studied, including 831 subjects with both prenatal and early childhood PCE exposure and 547 unexposed subjects. Participants completed questionnaires to gather information on mental illnesses, demographic and medical characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure originating from the vinyl-liner of water distribution pipes was assessed using water distribution system modeling software that incorporated a leaching and transport algorithm. Results No meaningful increases in risk ratios (RR) for depression were observed among subjects with prenatal and early childhood exposure (RR: 1.1, 95% CI: 0.9-1.4). However, subjects with prenatal and early childhood exposure had a 1.8-fold increased risk of bipolar disorder (N = 36 exposed cases, 95% CI: 0.9-1.4), a 1.5-fold increased risk post-traumatic stress disorder (N = 47 exposed cases, 95% CI: 0.9-2.5), and a 2.1-fold increased risk of schizophrenia (N = 3 exposed cases, 95% CI: 0.2-20.0). Further increases in the risk ratio were observed for bipolar disorder (N = 18 exposed cases, RR; 2.7, 95% CI: 1.3-5.6) and post-traumatic stress disorder (N = 18 exposed cases, RR: 1.7, 95% CI: 0.9-3.2) among subjects with the highest exposure levels. Conclusions The results of this study provide evidence against an impact of early life exposure to PCE on the risk of depression. In contrast, the results provide support for an impact of early life exposure on the risk of bipolar disorder and post-traumatic stress disorder. The number of schizophrenia cases was too small to draw reliable conclusions. These findings should be confirmed in investigations of other similarly exposed populations. PMID:22264316

  3. Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment

    PubMed Central

    2011-01-01

    Background Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment. Methods The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates. Results Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates generated using the prior method (0.54, p < 0.0001). Conclusions The incorporation of sophisticated flow estimates in the exposure assessment method shifted the PCE exposure distribution downward, but did not meaningfully affect the exposure ranking of subjects or the strength of the association with the risk of breast cancer found in earlier analyses. Thus, the current analyses show a slightly elevated breast cancer risk for highly exposed women, with strengthened exposure assessment and minimization of misclassification by using the latest technology. PMID:21600013

  4. Affinity for risky behaviors following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

    PubMed Central

    2011-01-01

    Background Many studies of adults with acute and chronic solvent exposure have shown adverse effects on cognition, behavior and mood. No prior study has investigated the long-term impact of prenatal and early childhood exposure to the solvent tetrachloroethylene (PCE) on the affinity for risky behaviors, defined as smoking, drinking or drug use as a teen or adult. Objectives This retrospective cohort study examined whether early life exposure to PCE-contaminated drinking water influenced the occurrence of cigarette smoking, alcohol consumption, and drug use among adults from Cape Cod, Massachusetts. Methods Eight hundred and thirty-one subjects with prenatal and early childhood PCE exposure and 547 unexposed subjects were studied. Participants completed questionnaires to gather information on risky behaviors as a teenager and young adult, demographic characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure was estimated using the U.S. EPA's water distribution system modeling software (EPANET) that was modified to incorporate a leaching and transport model to estimate PCE exposures from pipe linings. Results Individuals who were highly exposed to PCE-contaminated drinking water during gestation and early childhood experienced 50-60% increases in the risk of using two or more major illicit drugs as a teenager or as an adult (Relative Risk (RR) for teen use = 1.6, 95% CI: 1.2-2.2; and RR for adult use = 1.5, 95% CI: 1.2-1.9). Specific drugs for which increased risks were observed included crack/cocaine, psychedelics/hallucinogens, club/designer drugs, Ritalin without a prescription, and heroin (RRs:1.4-2.1). Thirty to 60% increases in the risk of certain smoking and drinking behaviors were also seen among highly exposed subjects. Conclusions The results of this study suggest that risky behaviors, particularly drug use, are more frequent among adults with high PCE exposure levels during gestation and early childhood. These findings should be confirmed in follow-up investigations of other exposed populations. PMID:22136431

  5. Simulation of solute transport of tetrachloroethylene in ground water of the glacial-drift aquifer at the Savage Municipal Well Superfund Site, Milford, New Hampshire, 1960-2000

    USGS Publications Warehouse

    Harte, Philip T.

    2004-01-01

    The Savage Municipal Well Superfund site, named after the former municipal water-supply well for the town of Milford, is underlain by a 0.5-square mile plume of volatile organic compounds (VOCs), primarily tetrachloroethylene (PCE). The plume occurs mostly within a highly transmissive sand-and-gravel unit, but also extends to an underlying till and bedrock unit. The plume logistically is divided into two areas termed Operable Unit No. 1 (OU1), which contains the primary source area, and Operable Unit No. 2 (OU2), which is the extended plume area. PCE concentrations in excess of 100,000 parts per billion (ppb) had been detected in the OU1 area in 1995, indicating a likely Dense Non-Aqueous Phase Liquid (DNAPL) source. In the fall of 1998, the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA) installed a remedial system in OU1. The OU1 remedial system includes a low-permeability barrier that encircles the highest detected concentrations of PCE, and a series of injection and extraction wells. The barrier primarily sits atop bedrock and penetrates the full thickness of the sand and gravel; and in some places, the full thickness of the underlying basal till. The sand and gravel unit and the till comprise the aquifer termed the Milford-Souhegan glacial-drift aquifer (MSGD). Two-dimensional and three-dimensional finite-difference solute-transport models of the unconsolidated sediments (MSGD aquifer) were constructed to help evaluate solute-transport processes, assess the effectiveness of remedial activities in OU1, and to help design remedial strategies in OU2. The solute-transport models simulate PCE concentrations, and model results were compared to observed concentrations of PCE. Simulations were grouped into the following three time periods: an historical calibration of the distribution of PCE from the initial input (circa 1960) of PCE into the subsurface to the 1990s, a pre-remedial calibration from 1995 to 1998, and a remedial (post-barrier wall) calibration from 1998 to 1999. Model results also were checked against observed PCE concentrations from May and June 2000 as a post-audit of model performance. Results of the simulations of the two-dimensional model for the historical calibration indicate that the model-computed length of the plume is affected by the retardation factor (retardation). Values of retardation greater than 3 caused the longitudinal length of the computed plume to be too short compared to the observed plume. A retardation of 2-2.5 produced a reasonable comparison between computed and observed PCE concentrations. Testing of different starting times and rates of mass input of PCE indicated that the plume reaches a quasi steady-state distribution in about 20 years regardless of the rate of mass input or values of the solute-transport parameters (retardation, dispersion, and irreversible reaction) assigned the model. Results of the simulations of the three-dimensional model for the pre-remedial (1995-98) calibration of PCE for the OU2 area identified some spatial biases in computed concentrations that generally were unaffected by changes in retardation. The computed PCE concentrations exceeded observed concentrations along the northern part of the plume in OU2, where PCE increases were observed in a bedrock well. These results indicate that some PCE in this area may be entering the bedrock, which is not simulated in the model. Conversely, computed PCE concentrations were less than observed concentrations along the southern part of the plume in OU2. Because testing of high (above 4) values of retardation did little to reduce residuals, it is concluded that the low computed PCE concentrations along the southern flank are likely the result of an underestimation of the initial PCE mass in this area or an unaccounted source of PCE. Results of the simulations of the three-dimensional model for the remedial calibration period (1998-99) and po

  6. Tetrachloroethylene Degradation by Dithionite with Ultraviolet Activation

    E-print Network

    Zhang, Jingyuan

    2013-07-30

    experiments (blank control, reagent control and UV control) were conducted to prove the feasibility of applying the dithionite/UV ARP to degrade PCE. ARP degradation of PCE was studied under different pH (5, 7, 8, 9) and light intensities (2, 4, 7.3 mW/cm2...

  7. Arc products of transformer insulating systems containing tetrachloroethylene. Final report

    SciTech Connect

    Baum, B.; Boshart-Mikes, G.; Mikes, F.; Mulak, M.; Peck, W.R.; Mandelcorn, L.; Jones, E.A.; Marshall, G.R.; Studniartz, S.A.

    1986-03-01

    A low current laboratory arc interruption cell was adapted to study the arc products of Wecosol (C/sub 2/Cl/sub 4/) and 75W% C/sub 2/Cl/sub 4/-25W% mineral oil-solid insulation systems for fire resistant transformers to determine the toxicity hazard of arc failures of these transformers. The use of the relatively low current (40 to 50 ampere) arcs was justified on the basis that their maximum temperature was above the chemical reaction temperatures just as in the case of kiloampere arc failures of transformers. Analytical methods were developed to determine arc products, principally for COCl/sub 2/ (phosgene). A relative hazard criterion is presented. The major arc products of the Wecosol systems are Cl/sub 2/, HCl, C/sub 2/Cl/sub 6/ (reaction of Cl/sub 2/ + C/sub 2/Cl/sub 4/) and CCl/sub 4/, and the minor products are COCl/sub 2/, CO and CO/sub 2/. The principal arc failure hazard here would be due to Cl/sub 2/ and HCl, and there is a low probability of COCl/sub 2/ and CO hazards. The major arc products in the 75W% C/sub 2/Cl/sub 4/ + 25W% mineral oil systems are HCl and CCl/sub 4/, and HCl would present the principal arc failure hazard. The minor products include COCl/sub 2/ and H/sub 2/, and COCl/sub 2/ would present a low probability of toxicity hazard. The levels of H/sub 2/ were well below the explosive limits of H/sub 2/ and air. It was concluded that failure arc products from these C/sub 2/Cl/sub 4/ fluid based transformers should not be hazardous in most instances of failure, and that simple precautions would be sufficient to assure safe access and handling. 6 figs., 11 tabs.

  8. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR TETRACHLOROETHYLENE

    EPA Science Inventory

    The known toxic effects of perchloroethylene will be summarized, with citations from current scientific literature. The critical effects will be identified, and from this the RfD and RfC and cancer unit risk factors will be derived. The RfD and RfC are reference doses and air c...

  9. A first French assessment of population exposure to tetrachloroethylene from small dry cleaning facilities

    E-print Network

    Paris-Sud XI, Université de

    buildings housing a dry cleaning facility. These studies involved dry cleaning machines fitted with a Carbon such as the dry cleaning machine technology (fitted or unfitted with a carbon adsorber) and the ventilation (air cleaning establishments in 2002 operating 1 to 2 machines. Because of the lack of national data, a complete

  10. EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE IN CONTROLLED SPILL EXPERIMENTS

    EPA Science Inventory

    This paper presents some of the results of five of the techniques: cross borehole complex resistivity (CR) also referred to as spectral induced polarization (SIP), cross borehole high resolution seismic (HRS), borehole self potential (SP), surface ground penetration radar (GPR), ...

  11. Identification of active agents for tetrachloroethylene degradation in Portland cement slurry containing ferrous iron

    E-print Network

    Ko, Sae Bom

    2006-08-16

    the the important elements that affect degradation activity. Elemental compositions of the mixtures and the conditions affecting solid formation might be the important factors in determining how active solids are formed. Second, instrumental analyses (XRD, SEM, SEM...

  12. KINETICS OF VINYL RADICAL REACTIONS WITH ETHYLENE, TRANS-1,2-DICHLOROETHYLENE, AND TETRACHLOROETHYLENE. (R826167)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. SOLUBILIZATION OF DODECANE, TETRACHLOROETHYLENE, AND 1,2-DICHLOROBENZENE IN MICELLAR SOLUTIONS OF ETHOXYLATED NONIONIC SURFACTANTS

    EPA Science Inventory

    Although surfactants have received considerable attention as a potential means for enhancing the recovery of organic compounds from the subsurface, only limited information is available regarding the micellar solubilization of common groundwater contaminants by nonionic surfactan...

  14. INFLUENCE OF VISCOUS AND BUOYANCY FORCES ON THE MOBILIZATION OF RESIDUAL TETRACHLOROETHYLENE DURING SURFACTANT FLUSHING

    EPA Science Inventory

    The potential for nonaqueous phase liquid (NAPL) mobilization is one of the most important considerations in the development and implementation of surfactant-based remediation technologies. Column experiments were performed to investigate the onset and extent of tetrachloroethyle...

  15. EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE IN CONTROLLED SPILL EXPERIMENTS

    EPA Science Inventory

    The purpose of the work was to determine the capability of various geophysical methods to detect PCE in the subsurface. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This approach provided a clear identification of a...

  16. SURFACTANT ENHANCED RECOVERY OF TETRACHLOROETHYLENE FROM A POROUS MEDIUM CONTAINING LOW PERMEABILITY LENSES. 2. NUMERICAL SIMULATION. (R825409)

    EPA Science Inventory

    Abstract A numerical model of surfactant enhanced solubilization was developed and applied to the simulation of nonaqueous phase liquid recovery in two-dimensional heterogeneous laboratory sand tank systems. Model parameters were derived from independent, small-scale, ...

  17. Abstract Pseudomonas stutzeri OX1 naphthalene-oxi-dation activity is induced 3.0-fold by tetrachloroethylene

    E-print Network

    Wood, Thomas K.

    (PCE) and trichloroethylene (TCE) are suspected carcinogens, regulated to levels of five parts per billion under the Safe Drinking Water Act. These compounds are the most common groundwater pollutants degradation of TCE and PCE (McCarty 1997); VC is a known human carcinogen (McCarty 1997) whereas both VC

  18. Evaluation of modeling for groundwater flow and tetrachloroethylene transport in the Milford-Souhegan glacial-drift aquifer at the Savage Municipal Well Superfund site, Milford, New Hampshire, 2011

    USGS Publications Warehouse

    Harte, Philip T.

    2012-01-01

    The U.S. Geological Survey and the New Hampshire Department of Environmental Services entered into a cooperative agreement to assist in the evaluation of remedy simulations of the MSGD aquifer that are being performed by various parties to track the remedial progress of the PCE plume. This report summarizes findings from this evaluation. Topics covered include description of groundwater flow and transport models used in the study of the Savage Superfund site (section 2), evaluation of models and their results (section 3), testing of several new simulations (section 4), an assessment of the representation of models to simulate field conditions (section 5), and an assessment of models as a tool in remedial operational decision making (section 6).

  19. 75 FR 30401 - National Primary Drinking Water Regulations; Announcement of the Results of EPA's Review of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ...action as candidates for revision (i.e. acrylamide, epichlorohydrin, tetrechloroethylene and trichloroethylene). This information...regulatory revision. These four NPDWRs are acrylamide, epichlorohydrin, tetrachloroethylene, and trichloroethylene. EPA...

  20. 1) Please define and give one example to explain the following terms. (18%) [A] Liebig's law of the minimum [B] Thermal stratification

    E-print Network

    Huang, Haimei

    contains benzene, toluene, ethylbenzene and xylene (BTEX) and tetrachloroethylene(PCE), has been leakage for many years. After sampling and analysis, concentrationsof BTEX and PCE in groundwater directlybeneath

  1. 40 CFR 264.1080 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Tetrachloroethylene; Tetrahydrofuran; Thallium; Toluene; Toluene 2,4 Diisocyanate; Trichloroethylene; Trichloroflouromethane; Vanadium; Vinyl Chloride; Warfarin; Xylene; Zinc. (g) This section applies only to the facility commonly referred to as the...

  2. 40 CFR 265.1080 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Tetrachloroethylene; Tetrahydrofuran; Thallium; Toluene; Toluene 2,4 Diisocyanate; Trichloroethylene; Trichloroflouromethane; Vanadium; Vinyl Chloride; Warfarin; Xylene; Zinc. (g) This section applies only to the facility commonly referred to as the...

  3. EVALUATION OF EMISSION TEST METHODS FOR HALOGENATED HYDROCARBONS. VOLUME I, CC14, C2H4C12, C2C14, AND C2HC13

    EPA Science Inventory

    A test method for halogenated hydrocarbons has been evaluated and information is provided for the user. Four compounds were investigated, carbon tetrachloride, ethylene dichloride, tetrachloroethylene, and trichloroethylene. The subject compounds remained stable in compressed gas...

  4. TEMPERATURE DEPENDENCE OF THE EMISSION OF PERCHLOROETHYLENE FROM DRY CLEANED FABRICS

    EPA Science Inventory

    The article discusses an evaluation of the emission of perchloroethylene (tetrachloroethylene) from freshly dry cleaned fabrics using small environment test chambers. he temperature dependence of the release of perchloroethylene was evaluated over a temperature range of 20 to 45 ...

  5. THE TEMPERATURE DEPENDENCE OF THE EMISSION OF PERCHLORO- ETHYLENE FROM DRY CLEANED FABRICS

    EPA Science Inventory

    A study was conducted to evaluate the emission of perchloroethylene (tetrachloroethylene) from freshly dry cleaned fabrics using small environmental test chambers. The temperature dependence of the release of perchloroethylene was evaluated over a temperature range of 20 to 45°C....

  6. FIELD EVALUATION OF THE SOLVENT EXTRACTION RESIDUAL BIOTREATMENT (SERB) TECHNOLOGY

    EPA Science Inventory

    The Solvent Extraction Residual Biotreatment (SERB) technology was demonstrated at the former Sage's Dry Cleaner site in Jacksonville, FL where an area of PCE (tetrachloroethylene) contamination was identified. The SERB technology is a treatment train approach to complete site...

  7. Applications of Monitored Natural Attenuation in the USA (Presentation)

    EPA Science Inventory

    Monitored Natural Attenuation (MNA) is widely applied in the USA to control the risk associated with ground water contamination from chlorinated solvents such a tetrachloroethylene (PCE) and trichloroethylene (TCE). MNA relies on the natural processes of degradation, sorption an...

  8. Applications of Monitored Natural Attenuation in the USA (Abstract)

    EPA Science Inventory

    Monitored Natural Attenuation (MNA) is widely applied in the USA to control the risk associated with ground water contamination from chlorinated solvents such a tetrachloroethylene (PCE) and trichloroethylene (TCE). MNA relies on the natural processes of degradation, sorption an...

  9. FIELD EVALUATION OF A SIMPLE MICROCOSM SIMULATING THE BEHAVIOR OF VOLATILE ORGANIC COMPOUNDS IN SUBSURFACE MATERIALS

    EPA Science Inventory

    A simple batch microcosm had previously been developed to simulate the behavior of volatile organic compounds in unconsolidated subsurface material. The microcosm was evaluated by comparing the behavior of tetrachloroethylene, bromoform, carbon tetrachloride, 1,2-dichlorobenzene,...

  10. NATURAL GRADIENT EXPERIMENT ON SOLUTE TRANSPORT IN A SAND AQUIFER. 4. SORPTION OF ORGANIC SOLUTES AND ITS INFLUENCE ON MOBILITY

    EPA Science Inventory

    Laboratory investigations were conducted to determine whether the observed field retardation of bromoform, carbon tetrachloride, tetrachloroethylene, 1,2-dichlorobenzene, and hexachloroethane at the Borden field site could be explained by the linear, reversible, equilibrium sorpt...

  11. IN-PLACE REGENERATION OF SVE LOADED GAC USING FENTON'S REAGENTS

    EPA Science Inventory

    Ten out of the 25 most frequently detected groundwater contaminants at hazardous waste sites are chlorinated volatile organic compounds (VOCs) 1. Trichloroethylene (TCE) and tetrachloroethylene (PCE) are among the top three 1. Granular activated carbon (GAC) adsorption is widel...

  12. IN-PLACE REGENERATION OF SVE LOADED GAC USING FENTON'S REAGENTS

    EPA Science Inventory

    Ten out of the 25 most frequently detected groundwater contaminants at hazardous waste sites are chlorinated volatile organic compounds (VOCs) 1 . Trichloroethylene (TCE) and tetrachloroethylene (PCE) are among the top three 1 . Granular activated carbon (GAC) adsorption is w...

  13. EMISSIONS OF PERCHLOROETHYLENE FROM DRY CLEANED FABRICS

    EPA Science Inventory

    A study was conducted to evaluate the emissions of perchloroethylene (tetrachloroethylene) from dry cleaned fabrics to determine: (a) how the introduction of fresh dry cleaning into a home affects the indoor concentration of perchloroethylene, and (b) the effectiveness of ?airing...

  14. EMISSIONS OF PERCHLOROETHYLENE FROM DRY CLEANED FABRICS

    EPA Science Inventory

    The paper gives results of an evaluation of emissions of perchloroethylene (tetrachloroethylene) from dry cleaned fabrics to determine: how introducing fresh dry cleaning into a home affects the indoor concentration of perchloroethylene, and the effectiveness of "airing out" dry ...

  15. DEMONSTRATION BULLETIN: AQUADETOX®/ SVE SYSTEM and AWD Technologies, Inc.

    EPA Science Inventory

    The AWD technology simultaneously treats groundwater and soil-gas contaminated with volatile or ganic compounds (VOC), such as trichloroethylene (TCE) and tetrachloroethylene (PCE). This technology integrates two processes: (1) AquaDetox®, a moderate vacuum (pressure about 50 ...

  16. FIELD APPLICATIONS OF CHEMICAL TIME-SERIES SAMPLING

    EPA Science Inventory

    Two municipal supply wells in Lakewood, Washington, were found to be contaminated with trichloroethylene, transdichloroethylene, and tetrachloroethylene. Sequential samples were taken for chemical analyses, in conjunction with drawdown measurement during aquifer (pump) tests desi...

  17. ANAEROBIC BIOTRANSFORMATIONS OF POLLUTANT CHEMICALS IN AQUIFERS (JOURNAL VERSION)

    EPA Science Inventory

    Anaerobic microbial communities sampled from either a methanogenic or sulfate-reducing aquifer site have been tested for their ability to degrade a variety of groundwater pollutants, including halogenated aromatic compounds, simple alkyl phenols and tetrachloroethylene. The haloa...

  18. CATALYTIC HYDRODEHALOGENATION OF CHLORINATED ETHYLENES USING PALLADIUM AND HYDROGEN FOR THE TREATMENT OF CONTAMINATED WATER. (R825689C054,R825689C060)

    EPA Science Inventory

    Abstract A kinetic model is presented for the catalytic hydrodehalogenation of chlorinated ethylenes using Pd and H2 under water treatment conditions. All five chlorinated ethylenes, including tetrachloroethylene (PCE) and vinyl chloride, were completely rem...

  19. BINARY DESORPTION ISOTHERMS OF TCE AND PCE FROM SILICA GEL AND NATURAL SOLIDS. (R822626)

    EPA Science Inventory

    Binary solute desorption isotherms of trichloroethylene (TCE) and tetrachloroethylene (PCE) at 100% relative humidity from silica gel and two well-characterized natural solids were investigated. Results indicated that the ideal adsorbed solution theory (IAST) was able to descr...

  20. Generalized solution to multispecies transport equations coupled with a first-order reaction network

    E-print Network

    Clement, Prabhakar

    at complex field sites because most field problems involve multiple reactive contaminants. Examples include nuclear waste sites contaminated with radioactive species and their daughter products and hazardous waste sites contaminated with chlorinated solvents such as PCE (tetrachloroethylene) and TCE

  1. BIOVENTING OF CHLORINATED SOLVENTS FOR GROUND-WATER CLEANUP THROUGH BIOREMEDIATION

    EPA Science Inventory

    Chlorinated solvents such as tetrachloroethylene, trichloroethylene, carbon tetrachloride, chloroform, 1,2-dichloroethane, and dichloromethane (methylene chloride) can exist in contaminated subsurface material as (1) the neat oil, (2) a component of a mixed oily waste, (3) a solu...

  2. Some hepatotoxic actions of hexachloroethane and its metabolites in sheep

    PubMed Central

    Fowler, J. S. L.

    1969-01-01

    1. Pentachloroethane and tetrachloroethylene were major metabolites of hexachloroethane in sheep. 2. Concentrations of hexachloroethane, pentachloroethane and tetrachloroethylene were determined by gas-liquid chromatography in blood, bile, faeces, urine and tissues after oral administration of hexachloroethane emulsions to sheep. 3. Increased blood concentrations of sorbitol dehydrogenase, glutamate dehydrogenase, and ornithine carbamoyl transferase were found to follow oral administration of hexachloroethane or pentachloroethane. 4. The rate of bromsulphthalein transfer from liver cells to bile was found to decrease after oral administration of hexachloroethane. PMID:5809742

  3. Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder

    Microsoft Academic Search

    Dong I. Oh; Kyongphile Nam; Jae W. Park; Jee H. Khim; Yong K. Kim; Jae Y. Kim

    2008-01-01

    A series of batch tests were performed and the impacts of environmental conditions and phase change on the sorption of volatile organic compounds (VOCs) were investigated. Benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well demonstrated by a linear-partitioning model. Water–tire partition coefficients of VOCs (not tested in this study) could

  4. OXIDATION OF WATER SUPPLY REFRACTORY SPECIES BY OZONE WITH ULTRAVIOLET RADIATION

    EPA Science Inventory

    The use of ozone with ultraviolet radiation was studied as an advanced treatment process for the removal of micropollutants and trihalomethane precursors from drinking water. The model compounds chloroform, bromo-dichloromethane, tetrachloroethylene and 2,2',4,4',6,6'-hexachlorob...

  5. FIELD MEASUREMENT OF VAPOR INTRUSION RATES AT A PCE SITE (ABSTRACT ONLY)

    EPA Science Inventory

    A field study was performed to evaluate vapor intrusion (VI) of tetrachloroethylene (PCE) and other chlorinated solvents at a commercial retail site in Dallas, TX. The building is approximately 40 years old and once housed a dry cleaning operation. Results from an initial site ch...

  6. SYNERGISTIC AND ANTAGONISTIC EFFECTS ON GENOTOXICITY OF CHEMICALS COMMONLY FOUND IN HAZARDOUS WASTE SITES

    EPA Science Inventory

    Synergistic and antagonistic effects on genotoxicity of mixtures of four chemicals; i.e., lead tetraacetate (LTA), arsenic trioxide (ATO), dieldrin (DED), and tetrachloroethylene (TCE), were evaluated by the Tradescantia-Micronucleus (Trad-MCN) assay. he concentration of stock so...

  7. Thermal desorption of atmospheric organic pollutants enriched on charcoal

    Microsoft Academic Search

    L. Senf; F. Stapf; B. Diisedau; H. Frank

    1988-01-01

    A technique of thermal vacuum desorption of charcoal, used in passive dosimeters to enrich organic pollutants of toxicological importance, is described. It combines the advantages of the classic procedure of using highly active charcoal followed by solvent desorption and the environmental one-step procedure of analyzing the whole thermally desorbed sample. For pollutants such as trichloroethylene, tetrachloroethylene, ether, benzene and ethanol,

  8. ATSDR MEDIA ANNOUNCEMENT Federal Health Agency Completes Analyses of Tarawa Terrace Drinking Water

    E-print Network

    Jacobs, Laurence J.

    ATSDR MEDIA ANNOUNCEMENT Federal Health Agency Completes Analyses of Tarawa Terrace Drinking Water of the Tarawa Terrace drinking water system, at U.S. Marine Corps Base Camp Lejeune, North Carolina, that former 1957 through February 1987, received drinking water contaminated with tetrachloroethylene (PCE

  9. Infrared transmission at the 3.39 micron helium-neon laser wavelength in liquid-core quartz fibers

    NASA Technical Reports Server (NTRS)

    Majumdar, A. K.; Hinkley, E. D.; Menzies, R. T.

    1979-01-01

    Infrared transmission at the 3.39 micron helium-neon laser wavelength has been measured in a tetrachloroethylene-filled fused-quartz fiber. The loss measurements were taken for three different settings of laser light intensity using a series of neutral density filters. The average value of transmission loss at this wavelength was found to be 56 dB/km.

  10. Synthesis and Application of Carbon-Iron Oxide Microspheres' Black Pigments in Electrophoretic Displays

    NASA Astrophysics Data System (ADS)

    Meng, Xianwei; Wen, Ting; Sun, Shiwei; Zheng, Rongbo; Ren, Jun; Tang, Fangqiong

    2010-10-01

    Carbon-iron oxide microspheres’ black pigments (CIOMBs) had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays.

  11. The dependence of nonthermal plasma behavior of VOCs on their chemical structures

    Microsoft Academic Search

    S. Futamura; A. H. Zhang; T. Yamamoto

    1997-01-01

    The dependence of nonthermal plasma behavior of volatile organic compounds (VOCs) on their chemical structures was investigated, using methane, ethane, ethylene, butane, 1,1,2-trichloroethane, trichloroethylene, and tetrachloroethylene as target VOCs. It has been shown that the above VOCs decompose homolytically via their excited states, irrespective of their electron affinities. Efficiencies of energy transfer from hot electrons to the VOCs could be

  12. MEASUREMENT OF PERCHLOROETHYLENE IN AMBIENT AIR

    EPA Science Inventory

    Perchloroethylene (i.e., tetrachloroethylene) is an organic solvent widely used in dry cleaning and industrial metal degreasing operations. Short-term field studies were conducted in each of three major metropolitan areas which were selected on the basis of the number, density an...

  13. Groundwater contamination and risk assessment of industrial complex in Busan Metropolitan City, Korea

    Microsoft Academic Search

    S.-Y. Hamm; S. M. Ryu; J.-Y. Cheong; Y.-J. Woo

    2003-01-01

    In Korea, the potential of groundwater contamination in urban areas is increasing by industrial and domestic waste waters, leakage from oil storage tanks and sewage drains, leachate from municipal landfill sites and so on. Nowadays, chlorinated organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE), which are driving residential area as well as industrial area, are recognized as major hazardous

  14. COMMUNICATION TO THE EDITOR Aerobic Degradation of Mixtures of

    E-print Network

    Wood, Thomas K.

    (TCE) INTRODUCTION Both tetrachloroethylene (PCE) and trichloroethylene (TCE) are suspected carcinogens and are the most common groundwater pollutants at hazardous waste sites (McCarty, 1997). These effective solvents carcinogen (McCarty, 1997). Both VC and cis-DCE are U.S. Environmental Protection Agency priority pollut

  15. Some experiments on ultrasonic cavitation using a pulsed neutron source

    Microsoft Academic Search

    R. Howlett

    1968-01-01

    Experiments on the prompt neutron-induced cavitation effect in tetrachloroethylene are described. Cavitation bubbles were detected by the fast acoustic signals they emit, probably during the collapse phase. Using a pulsed fast-neutron source phase locked to the acoustic field, and a time analyser, information was obtained on the history of bubbles which were nucleated at a known phase of the sound

  16. COMPLETE NATURAL ATTENUATION OF PCE AND TCE WITHOUT VINYL CHLORIDE AND ETHENE ACCUMULATION

    EPA Science Inventory

    A shallow aquifer at the Twin Cities Army Ammunition Plant (TCAAP) was contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE). Cisdichloroethylene (cis-DCE) is found in ground water at the site, indicating that reductive dehalogenation of PCE and TCE is occurrin...

  17. Enhanced reductive dechlorination of PCE DNAPL with TBOS as a slow-release electron donor

    Microsoft Academic Search

    Seungho Yu; Lewis Semprini

    2009-01-01

    Tetrabutoxysilane (TBOS), which yields 1-butanol upon abiotic hydrolysis, was evaluated as a slow-release substrate for the reductive dechlorination of tetrachloroethylene (PCE) as a dense non-aqueous-phase liquid (DNAPL). Dechlorination was achieved using an anaerobic binary mixed (BM) culture, which consisted of the Pt. Mugu (PM) and the Evanite (EV) mixed cultures. In batch reactor experiments, TBOS was mixed with PCE DNAPL

  18. Biodegradation of chlorinated aliphatic hydrocarbon mixtures in a single-pass packed-bed reactor

    Microsoft Academic Search

    L. W. Lackey; T. J. Phelps; P. R. Bienkowski; D. C. White

    1993-01-01

    Aliphatic chlorinated compounds, such as trichloroethylene (TCE) and tetrachloroethylene (PCE), are major contaminants of\\u000a ground water. A single-pass packed-bed bioreactor was utilized to study the biodegradation of organic waste mixtures consisting\\u000a of PCE, TCE, and other short-chain chlorinated organics. The bioreactor consisted of two 1960-mL glass columns joined in a\\u000a series. One column was packed with sand containing a microbial

  19. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin.

  20. H-Area Seepage Basins groundwater monitoring report. Second quarter 1992

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin.

  1. Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons

    DOEpatents

    Fliermans, Carl B. (Augusta, GA)

    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.

  2. In situ air stripping using horizontal wells. Innovative technology summary report

    SciTech Connect

    NONE

    1995-04-01

    In-situ air stripping employs horizontal wells to inject or sparge air into the ground water and vacuum extract VOC`S from vadose zone soils. The horizontal wells provide better access to the subsurface contamination, and the air sparging eliminates the need for surface ground water treatment systems and treats the subsurface in-situ. A full-scale demonstration was conducted at the Savannah River Plant in an area polluted with trichloroethylene and tetrachloroethylene. Results are described.

  3. Experimental Results on the Destruction of PCE using a PhotoChemical Remediation Reactor

    Microsoft Academic Search

    J. J. Lee; K. Y. Lee; J. R. Stencel; J. Khinast

    2001-01-01

    A vapor-phase tetrachloroethylene (PCE) destruction experiment using a newly constructed photo-chemical remediation (PCR) reactor is performed. One of the applications for the PCR reactor is subsurface remediation of volatile organic compounds (VOCs). Ultraviolet (UV) light, when emitted at an effective absorption frequency (primary wavelengths of 185 and 254 nm), cleaves a VOC's carbon-chlorine bond thus reducing harmful contaminants to harmless

  4. Remediation of PCE-contaminated aquifer by an in situ two-layer biobarrier: laboratory batch and column studies

    Microsoft Academic Search

    C. M Kao; S. C Chen; J. Y Wang; Y. L Chen; S. Z Lee

    2003-01-01

    The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop an in situ two-layer biobarrier system consisting of an organic-releasing material layer followed by an oxygen-releasing material layer. The organic-releasing material, which contained sludge cakes from a domestic wastewater treatment plant, is able to release biodegradable

  5. Synthesis and Application of Carbon–Iron Oxide Microspheres’ Black Pigments in Electrophoretic Displays

    PubMed Central

    2010-01-01

    Carbon–iron oxide microspheres’ black pigments (CIOMBs) had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays. PMID:21076669

  6. Reductive dechlorination catalyzed by bacterial transition-metal coenzymes

    Microsoft Academic Search

    Charles J. Gantzer; Lawrence P. Wackett

    1991-01-01

    The bacterial transition-metal coenzymes vitamin Bââ (Co), coenzyme Fâââ (ni), and hematin (Fe) catalyzed the reductive dechlorination of polychlorinated ethylenes and benzenes, whereas the electron-transfer proteins four-iron ferredoxin, two-iron ferredoxin, and azurin (Cu) did not. For vitamin Bââ and coenzyme Fâââ, reductive dechlorination rates for different classes of perchlorinated compounds had the following order: carbon tetrachloride > tetrachloroethylene > hexachlorobenzene.

  7. Computer adaptation of an inverse solution technique to the analytical contaminant transport equation

    E-print Network

    Dale, Timothy Forbes

    1990-01-01

    coordinate requirements for steady and unsteady state well selections. . . . . . . . 51 Listing of: (a) well combinations and best source dimensions; and (b) average source dimensions and standard deviations; for tetrachloroethylene field study.... . . . . . . . . . . (a) Listing of determining governing parameters; and (b) Comparison of inputted versus calculated well concentrations. . . . . . 69 Listing of erf (B) and erfc(B) values for selected Beta values. 79 LIST OF FIGURES Figure page Idealized...

  8. Distribution of selected volatile organic compounds determined with water-to-vapor diffusion samplers at the interface between ground water and surface water, Centredale Manor site, North Providence, Rhode Island, September 1999

    USGS Publications Warehouse

    Church, Peter E.; Lyford, Forest P.; Clifford, Scott

    2000-01-01

    Volatile organic compounds are present in soils and ground water at the Centredale Manor Superfund Site in North Providence, Rhode Island. In September 1999, water-to-vapor diffusion samplers were placed in the bottom sediments of waterways adjacent to the site to identify possible contaminated ground-water discharge areas. The approximate12-acre site is a narrow stretch of land between the eastern bank of the Woonasquatucket River, downstream from the U.S. Route 44 bridge and a former mill raceway. The samplers were placed along a 2,250-foot reach of the Woonasquatucket River, in the former mill raceway several hundred feet to the east and parallel to the river, and in a cross channel between the river and former mill raceway. Volatile organic compounds were detected in 84 of the 104 water-to-vapor diffusion samplers retrieved. Trichloroethylene and tetrachloro-ethylene were the principal volatile organic compounds detected. The highest vapor concentrations measured for these two chemicals were from diffusion samplers located along an approximate 100-foot reach of the Woonasquatucket River about 500 feet downstream of the bridge; here trichloroethylene and tetrachloroethylene vapor concentrations ranged from about 2,000 to 180,000 and 1,600 to 1,400,000 parts per billion by volume, respectively. Upstream and downstream from this reach and along the former mill raceway, trichloroethylene and tetrachloroethylene vapor concentrations from the diffusion samples were generally less than 100 parts per billion by volume. Along the lower reaches of the river and mill raceway, however, and in the cross channel, vapor concentrations of trichloroethylene exceeded 100 parts per billion by volume and tetrachloroethylene exceeded 1,000 parts per billion by volume in several diffusion samples. Although diffusion sample vapor concentrations are higher than water concentrations in surface waters and in ground water, and they should only be interpreted qualitatively as relative values, these values provide important information as to potential discharge areas of contaminants.

  9. Evaluation of the atmosphere as a source of volatile organic compounds in shallow groundwater

    Microsoft Academic Search

    Arthur L. Baehr; Paul E. Stackelberg; Ronald J. Baker

    1999-01-01

    The atmosphere as a source of volatile organic compounds (VOCs) in shallow groundwater was evaluated over an area in southern New Jersey. Chloroform, methyl tertbutyl ether (MTBE), 1,1,1-trichloroethane, tetrachloroethylene (PCE), and carbon disulfide (not a VOC) were detected frequently at low-level concentrations in a network of 78 shallow wells in the surficial Kirkwood-Cohansey aquifer system. The atmosphere was sampled for

  10. H-Area Seepage Basins groundwater monitoring report. First quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, antimony, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Site. This report presents and discusses the groundwater monitoring results in the H-Area for first quarter 1992.

  11. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, antimony, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Site. This report presents and discusses the groundwater monitoring results in the H-Area for first quarter 1992.

  12. Cancer in Persons Working in Dry Cleaning in the Nordic Countries

    PubMed Central

    Lynge, Elsebeth; Andersen, Aage; Rylander, Lars; Tinnerberg, Håkan; Lindbohm, Marja-Liisa; Pukkala, Eero; Romundstad, Pål; Jensen, Per; Clausen, Lene Bjørk; Johansen, Kristina

    2006-01-01

    U.S. studies have reported an increased risk of esophageal and some other cancers in dry cleaners exposed to tetrachloroethylene. We investigated whether the U.S. findings could be reproduced in the Nordic countries using a series of case–control studies nested in cohorts of laundry and dry-cleaning workers identified from the 1970 censuses in Denmark, Norway, Sweden, and Finland. Dry-cleaning work in the Nordic countries during the period when tetrachloroethylene was the dominant solvent was not associated with an increased risk of esophageal cancer [rate ratio (RR) = 0.76; 95% confidence interval (CI), 0.34–1.69], but our study was hampered by some unclassifiable cases. The risks of cancer of the gastric cardia, liver, pancreas, and kidney and non-Hodgkin lymphoma were not significantly increased. Assistants in dry-cleaning shops had a borderline significant excess risk of cervical cancer not found in women directly involved in dry cleaning. We found an excess risk of bladder cancer (RR = 1.44; 95% CI, 1.07–1.93) not associated with length of employment. The finding of no excess risk of esophageal cancer in Nordic dry cleaners differs from U.S. findings. Chance, differences in level of exposure to tetrachloroethylene, and confounding may explain the findings. The overall evidence on bladder cancer in dry cleaners is equivocal. PMID:16451857

  13. Cancer in persons working in dry cleaning in the Nordic countries.

    PubMed

    Lynge, Elsebeth; Andersen, Aage; Rylander, Lars; Tinnerberg, Håkan; Lindbohm, Marja-Liisa; Pukkala, Eero; Romundstad, Pål; Jensen, Per; Clausen, Lene Bjørk; Johansen, Kristina

    2006-02-01

    U.S. studies have reported an increased risk of esophageal and some other cancers in dry cleaners exposed to tetrachloroethylene. We investigated whether the U.S. findings could be reproduced in the Nordic countries using a series of case-control studies nested in cohorts of laundry and dry-cleaning workers identified from the 1970 censuses in Denmark, Norway, Sweden, and Finland. Dry-cleaning work in the Nordic countries during the period when tetrachloroethylene was the dominant solvent was not associated with an increased risk of esophageal cancer [rate ratio (RR) = 0.76; 95% confidence interval (CI), 0.34-1.69], but our study was hampered by some unclassifiable cases. The risks of cancer of the gastric cardia, liver, pancreas, and kidney and non-Hodgkin lymphoma were not significantly increased. Assistants in dry-cleaning shops had a borderline significant excess risk of cervical cancer not found in women directly involved in dry cleaning. We found an excess risk of bladder cancer (RR = 1.44; 95% CI, 1.07-1.93) not associated with length of employment. The finding of no excess risk of esophageal cancer in Nordic dry cleaners differs from U.S. findings. Chance, differences in level of exposure to tetrachloroethylene, and confounding may explain the findings. The overall evidence on bladder cancer in dry cleaners is equivocal. PMID:16451857

  14. Contamination of shallow ground water in the area of building 95, Picatinny Arsenal, New Jersey, 1985-90

    USGS Publications Warehouse

    Sargent, B.P.; Storck, D.A.

    1994-01-01

    A zone of contaminated ground water at Picatinny Arsenal has resulted from the operation of a metal- plating facility in building 95 during 1960-81, and the wastewater-treatment system that is in and adjacent to the building. Thirty-two monitoring wells were installed in 1989 to supplement 12 previously installed wells. All wells were sampled in 1989 and 1990 for analysis of ground water for inorganic constituents, trace elements, volatile organic compounds, and nutrients. Four wells also were sampled for analysis for base/neutral- and acid-extractable compounds and pesticides, and soil gas from the unsaturated zone at eight sites was analyzed for volatile organic compounds. Concentrations of dissolved solids and sulfate in the study area were consistently above the U.S. Environmental Protection Agency's secondary drinking-water regulations. The areal distribution of sulfate differed from that of the volatile organic compounds. Concentrations of trace elements were not elevated downgradient from the source. The estimated average velocity of contaminant movement is 0.1 to 1.1 feet per day. The major organic contaminants identified in the study area are trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane. Trichloroethylene was detected in wells upgradient from the wastewater- treatment site. Tetrachloroethylene and 1,1,1-trichloroethane might originate at tanks in the basement of building 95 rather than at the adjacent wastewater-treatment system. The pre- dominant gas-phase contaminant, 1,1,1- trichloroethane, was detected at a maximum con- centration of 15.7 micrograms per liter. Both trichoroethylene and tetrachloroethylene were detected in concentrations greater than 0.10 micrograms per liter in five of the eight soil- gas samples, indicating that volatilization and diffusion through the unsaturated zone could be a significant mechanism of contaminant loss from the aquifer.

  15. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Second quarter 1993

    SciTech Connect

    Thompson, C.Y.

    1993-09-01

    During second quarter 1993, samples from AMB groundwater monitoring wells at the metallurgical Laboratory Hazardous Waste Management Facility (HWMF) were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS), and pH and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria in one or more of the wells. Dichloromethane (methylene chloride), a common laboratory contaminant which was first compared to its final PDWS during first quarter 1993, was elevated in three wells.

  16. Temperature dependence of the emission of perchloroethylene from dry-cleaned fabrics

    SciTech Connect

    Guo, Z.; Tichenor, B.A.; Mason, M.A.; Plunket, C.M.

    1990-01-01

    The article discusses an evaluation of the emission of perchloroethylene (tetrachloroethylene) from freshly dry cleaned fabrics using small environmental test chambers. The temperature dependence of the release of perchloroethylene was evaluated over a temperature range of 20 to 45 C. A linear relation exists between the logarithm of perchloroethylene retention time and the reciprocal of the absolute temperature. Study results for 100% wool and 55% polyester/45% wool indicate that airing out freshly dry cleaned fabrics at above ambient temperature will increase the rate at which perchloroethylene is emitted from the fabrics.

  17. Supplemental Technical Data Summary M-Area Groundwater Investigation

    SciTech Connect

    Marine, I.W., Bledsoe, H.W. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1995-10-01

    This supplement to the Preliminary Technical Data Summary (TDS) (Gordon, 1982) presents the state of knowledge on the hydrogeology and contaminant plume characteristics in the vicinity of M Area as of October 1984. As discussed in the previous TDS, the contaminants consist of organic solvents used for metal degreasing, namely trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane. Since the issuance of the previous TDS, the groundwater consulting firm of Geraghty & Miller, Inc. has been retained to assist with program strategy, planning, and investigative techniques

  18. Test plan for in situ bioremediation demonstration of the Savannah River Integrated Demonstration Project DOE/OTD TTP No.: SR 0566-01. Revision 3

    SciTech Connect

    Hazen, T.C.

    1991-09-18

    This project is designed to demonstrate in situ bioremediation of groundwater and sediment contaminated with chlorinated solvents. Indigenous microorganisms will be simulated to degrade trichloroethylene (TCE), tetrachloroethylene (PCE) and their daughter products in situ by addition of nutrients to the contaminated zone. in situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency and public and regulatory acceptability. Bioremediation has been found to be among the least costly technologies in applications where it will work.

  19. Intermedia transfer factors for fifteen toxic pollutants released to air basins in California

    SciTech Connect

    McKone, T.E.; Daniels, J.I. [Lawrence Livermore National Lab., CA (United States); Chiao, F.F.; Hsieh, D.P.H. [Univ. of California, Davis, CA (United States)

    1993-10-01

    This report provides a summary definition of the intermedia-transfer factors (ITFs). Methods are discussed for estimating these parameters in the absence of measured values, and the estimation errors inherent in these estimation methods are considered. A detailed summary is provided of measured and estimated ITF values for fifteen air contaminants. They include: 1,3 butadiene; cadmium; cellosolve; cellosolve acetate; chloroform; di-2-ethylhexylphthalate; 1,4-dioxame; hexachlorobenzene; inorganic arsenic; inorganic lead; nickel; tetrachloroethylene; toluene; toluene-2,4-diisocyanate; and 1,3-xylene. Recommendations are made regarding the expected value and variance in these values for use in exposure models.

  20. High charged red pigment nanoparticles for electrophoretic displays

    NASA Astrophysics Data System (ADS)

    Hou, Xin-Yan; Bian, Shu-Guang; Chen, Jian-Feng; Le, Yuan

    2012-12-01

    Organic pigment permanent red F2R nanoparticles were prepared via surface modification to improve the surface charge and dispersion ability in organic medium. Their large surface chargeability is confirmed by ?-potential value of -49.8 mV. The prepared particles exhibited average size of 105 nm and showed very narrow distribution with polydispersity index of 0.068. The sedimentation ratio of the prepared particles in tetrachloroethylene was less than 5% within 12 days. The electrophoretic inks consisting of the prepared red particles with white particles as contrast showed good electrophoretic display, its refresh time was 200 ms.

  1. Desorption Behavior of Trichloroethene and Tetrachloroethene in U.S. Department of Energy Savannah River Site Unconfined Aquifer Sediments

    SciTech Connect

    Riley, Robert G.; Szecsody, Jim E.; Mitroshkov, Alexandre V.; Brown, Christopher F.

    2006-06-21

    The DOE Savannah River Site (SRS) is evaluating the potential applicability of the monitored natural attenuation (MNA) process as a contributor to the understanding of the restoration of its unconfined groundwater aquifer known to be contaminated with the chlorinated hydrocarbon compounds trichloroethylene (TCE) and tetrachloroethylene (PCE). This report discusses the results from aqueous desorption experiments on SRS aquifer sediments from two different locations at the SRS (A/M Area; P-Area) with the objective of providing technically defensible TCE/PCE distribution coefficient (Kd) data and data on TCE/PCE reversible and irreversible sorption behavior needed for further MNA evaluation.

  2. Operations Support of Phase 2 Integrated Demonstration In Situ Bioremediation. Volume 4, Final report: Averaged data in tabular form, Disks 3,4; Averaged data in graphical form, Disks 1,2,3,4

    SciTech Connect

    Hazen, T.C. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1993-09-01

    This report contains experimental data collected during the demonstration of in situ bioremediation at the Savannah River Site. This project was designed to demonstrate in situ bioremediation of ground water and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade trichloroethylene, tetrachloroethylene, and their daughter products in situ by addition of nutrients to the contaminated aquifer and adjacent vadose zone. The principle carbon/energy source nutrient used in this demonstration was methane. In situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency, safety, and public and regulatory acceptability.

  3. TNX area groundwater monitoring report. 1996 Annual report

    SciTech Connect

    NONE

    1997-04-01

    During 1996, samples from selected wells of well cluster P 26 and the TBG, TIR, TNX, TRW, XSB, and YSB well series at the TNX Area of the Savannah River Plant were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Sixteen parameters exceeded the final Primary Drinking Water Standards (PDWS). Trichloroethylene exceeded the final PDWS most frequently. Antimony, arsenic beryllium, carbon tetrachloride, chloroform, chromium, copper, dichloromethane, gross alpha, lead, mercury, nitrate, nitrate-nitrite, tetrachloroethylene, or trichloroethylene were evaluated in one or more wells during the year. Groundwater flow directions and rates in the Unconfined Aquifer were similar from quarter to quarter during the year.

  4. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report: Third quarter 1993

    SciTech Connect

    Not Available

    1993-12-01

    During third quarter 1993, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards; and aluminum, iron, lead, manganese, pH, and total organic halogens exceeded the Savannah River Site Flag 2 criteria in one or more of the wells. Groundwater flow direction and rate in the water-table unit were similar to previous quarters.

  5. Mixed Waste Management Facility (MWMF) groundwater monitoring report. Second quarter 1993

    SciTech Connect

    Not Available

    1993-09-01

    Groundwater monitoring continued at the Savannah River Plant. During second quarter 1993, nine constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility, the Old Burial Ground, the E-Area Vaults, and the proposed Hazardous Waste/Mixed Waste Disposal Vaults. As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Chloroethene (vinyl chloride), dichloromethane (methylene chloride), 1,1-dichloroethylene, gross alpha, lead, nonvolatile beta, or tetrachloroethylene also exceeded standards in one or more wells. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  6. Mixed Waste Management Facility (MWMF) groundwater monitoring report. Fourth quarter 1992 and 1992 summary

    SciTech Connect

    Not Available

    1993-03-01

    During fourth quarter 1992, nine constituents exceeded final Primary Drinking Water Standards (PDWS) in one or more groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Fifty-seven (48%) of the 120 monitoring wells, contained elevated tritium activities, and 23 (19%) contained elevated trichloroethylene concentrations. Total alpha-emitting radium, tetrachloroethylene, chloroethene, cadmium, 1,1-dichloroethylene, lead, or nonvolatile beta levels exceeded standards in one or more wells. During 1992, elevated levels of 13 constituents were found in one or more of 80 of the 120 groundwater monitoring wells (67%) at the MWMF and adjacent facilities. Tritium and trichloroethylene exceeded their final PDWS more frequently and more consistently than did other constituents. Tritium activity exceeded its final PDWS m 67 wells and trichloroethylene was. elevated in 28 wells. Lead, tetrachloroethylene, total alpha-emitting radium, gross alpha, cadmium, chloroethene, 1,1-dichloroethylene 1,2-dichloroethane, mercury, or nitrate exceeded standards in one or more wells during the year. Nonvolatile beta exceeded its drinking water screening level in 3 wells during the year.

  7. Ground-penetrating radar monitoring of a controlled DNAPL release: 200 MHz radar

    SciTech Connect

    Brewster, M.L. (Komex International Ltd., Calgary, Alberta (Canada) Univ. of Waterloo, Ontario (Canada). Waterloo Centre for Groundwater Research); Annan, A.P. (Sensors and Software, Inc., Mississauga, Ontario (Canada) Univ. of Waterloo, Ontario (Canada). Waterloo Centre for Groundwater Research)

    1994-08-01

    A controlled release of tetrachloroethylene was performed in a saturated, natural sandy aquifer to evaluate the effectiveness of various geophysical techniques for detecting and monitoring dense nonaqueous phase liquids (DNAPLs) in the subsurface. Tetrachloroethylene, typical of most DNAPLs, has a low relative dielectric permittivity (2.3), which contrasts with the high relative permittivity (80) of the pore water it displaces, making it a potential target for detection by ground-penetrating radar (GPR). GPR data were acquired using 200 MHz antennas. Radar sections collected at different times over the same spatial location clearly show the changes induced by the movement of DNAPL in the subsurface. Temporal changes can be examined through the evolution of a radar data trace collected at a single spatial location. Normal moveout analysis of common-midpoint (CMP) data demonstrates induced changes in electromagnetic (EM) wave velocities of up to 30% caused by the presence of DNAPL. The distribution of DNAPL can be mapped in three dimensions at different times using a network of 16 radar lines. The 200 MHz GPR proved to be an effective technique for monitoring the movement of DNAPL in the subsurface. Direct detection of DNAPLs by radar is also feasible in this simple environment.

  8. Mixed Waste Management Facility (MWMF) groundwater monitoring report, second quarter 1992

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium (radium-226 and radium-228) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 55 (48%) of the 115 monitored wells contained elevated tritium activities, and 23 (20%) wells exhibited elevated trichloroethylene concentrations. Sixty-three downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB[sub 2] (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained concentrations of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium that exceeded the PDWS during second quarter 1992. Upgradient wells BGO 1D and 2D and HSB 85A, 85B, and 85C did not contain any constituents that exceeded the PDWS.

  9. Mixed Waste Management Facility (MWMF) groundwater monitoring report, second quarter 1992

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium (radium-226 and radium-228) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 55 (48%) of the 115 monitored wells contained elevated tritium activities, and 23 (20%) wells exhibited elevated trichloroethylene concentrations. Sixty-three downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB{sub 2} (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained concentrations of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium that exceeded the PDWS during second quarter 1992. Upgradient wells BGO 1D and 2D and HSB 85A, 85B, and 85C did not contain any constituents that exceeded the PDWS.

  10. Mixed Waste Management Facility groundwater monitoring report. Second quarter 1994

    SciTech Connect

    Chase, J.A.

    1994-09-01

    Currently, 125 wells monitor groundwater quality in the uppermost aquifer beneath the Mixed Waste Management Facility (MWMF) at the Savannah River Site. Samples from the wells are analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. During second quarter 1994, chloroethene (vinyl chloride), 1,1-dichloroethylene, gross alpha, lead, tetrachloroethylene, trichloroethylene, or tritium exceeded final Primary Drinking Water Standards (PDWS) in approximately half of the downgradient wells at the MWMF. Consistent with historical trends, elevated constituent levels were found primarily in Aquifer Zone. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents during second quarter 1994. Sixty-two of the 125 monitoring wells contained elevated tritium activities. Trichloroethylene concentrations exceeded the final PDWS in 23 wells. Chloroethene, 1,1-dichloroethylene, lead, and tetrachloroethylene, elevated in one or more wells during second quarter 1994, also occurred in elevated levels during first quarter 1994. These constituents generally were elevated in the same wells during both quarters. Gross alpha, which was not elevated in any well during first quarter 1994, was elevated in one well during second quarter. Copper, mercury, and nonvolatile beta were elevated during first quarter 1994 but not during second quarter.

  11. Health risk assessment of exposure to selected volatile organic compounds emitted from an integrated iron and steel plant.

    PubMed

    Chang, E-E; Wei-Chi, Wang; Li-Xuan, Zeng; Hung-Lung, Chiang

    2010-12-01

    Workplace air samples from sintering, cokemaking, and hot and cold forming processes in the integrated iron and steel industry were analyzed to determine their volatile organic compound (VOC) concentration. Sixteen VOC species including three paraffins (cyclohexane, n-hexane, methylcyclohexane), five chlorinated VOC species (trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, chlorobenzene, 1,4-dichlorobenzene), and eight aromatics (benzene, ethylbenzene, styrene, toluene, m,p-xylene, o-xylene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene) were selected to measure their noncancer risk for workers. Concentrations of toluene, xylene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, dichlorobenzene, and trichloroethylene were high in all four processes. Carbon tetrachloride and tetrachloroethylene concentrations were high in the hot and cold forming processes. The noncancer risk followed the increasing order: cokemaking > sintering > hot forming > cold forming. 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene contributed 44% to 65% and 13% to 20% of noncancer risk, respectively, for the four processes. Benzene accounted for a high portion of the noncancer risk in cokemaking. The hazard index (HI: 17-108) of the average VOC concentrations suggests that health risks can be reduced by improving workplace air quality and protecting workers. PMID:20828338

  12. Use of history science methods in exposure assessment for occupational health studies

    PubMed Central

    Johansen, K; Tinnerberg, H; Lynge, E

    2005-01-01

    Aims: To show the power of history science methods for exposure assessment in occupational health studies, using the dry cleaning industry in Denmark around 1970 as the example. Methods: Exposure data and other information on exposure status were searched for in unconventional data sources such as the Danish National Archives, the Danish Royal Library, archives of Statistics Denmark, the National Institute of Occupational Health, Denmark, and the Danish Labor Inspection Agency. Individual census forms were retrieved from the Danish National Archives. Results: It was estimated that in total 3267 persons worked in the dry cleaning industry in Denmark in 1970. They typically worked in small shops with an average size of 3.5 persons. Of these, 2645 persons were considered exposed to solvents as they were dry cleaners or worked very close to the dry cleaning process, while 622 persons were office workers, drivers, etc in shops with 10 or more persons. It was estimated that tetrachloroethylene constituted 85% of the dry cleaning solvent used, and that a shop would normally have two machines using 4.6 tons of tetrachloroethylene annually. Conclusion: The history science methods, including retrieval of material from the Danish National Archives and a thorough search in the Royal Library for publications on dry cleaning, turned out to be a very fruitful approach for collection of exposure data on dry cleaning work in Denmark. The history science methods proved to be a useful supplement to the exposure assessment methods normally applied in epidemiological studies. PMID:15961618

  13. Improvement of health risk factors after reduction of VOC concentrations in industrial and urban areas.

    PubMed

    Lerner, Jorge Esteban Colman; Kohajda, Tibor; Aguilar, Myriam Elisabeth; Massolo, Laura Andrea; Sánchez, Erica Yanina; Porta, Atilio Andrés; Opitz, Philipp; Wichmann, Gunnar; Herbarth, Olf; Mueller, Andrea

    2014-08-01

    After reductions of fugitive and diffuse emissions by an industrial complex, a follow-up study was performed to determine the time variability of volatile organic compounds (VOCs) and the lifetime cancer risk (LCR). Passive samplers (3 M monitors) were placed outdoors (n?=?179) and indoors (n?=?75) in industrial, urban, and control areas for 4 weeks. Twenty-five compounds including n-alkanes, cycloalkanes, aromatics, chlorinated hydrocarbons, and terpenes were determined by GC/MS. The results show a significant decrease of all VOCs, especially in the industrial area and to a lesser extent in the urban area. The median outdoor concentration of benzene in the industrial area declined compared to the former study, around 85% and about 50% in the urban area, which in the past was strongly influenced by industrial emissions. Other carcinogenic compounds like styrene and tetrachloroethylene were reduced to approximately 60%. VOC concentrations in control areas remained nearly unchanged. According to the determined BTEX ratios and interspecies correlations, in contrast to the previous study, traffic was identified as the main emission source in the urban and control areas and showed an increased influence in the industrial area. The LCR, calculated for benzene, styrene, and tetrachloroethylene, shows a decrease of one order of magnitude in accordance to the decreased total VOC concentrations and is now acceptable according to values proposed by the World Health Organization. PMID:24788932

  14. Appraisal of ground-water quality in the Bunker Hill Basin of San Bernardino Valley, California

    USGS Publications Warehouse

    Duell, L.F., Jr.; Schroeder, R.A.

    1989-01-01

    Water samples were collected from 47 wells and analyzed for concentration of major inorganic ions, nitrogen species, and volatile (purgeable) organic priority pollutants to assess groundwater quality in the Bunker Hill basin, California. Data were supplemented with additional analysis of nitrate, tetrachloroethylene, and trichloroethylene made by other agencies. The organic quality of groundwater in the basin generally is suitable for most uses, although fluoride concentration exceeded the California public drinking water standard of 1.4 mg/L in water from 5 of 47 wells. Nitrate (as nitrogen) concentration equaled or exceeded the public drinking water standard of 10 mg/L in water from 13 of 47 wells sampled for this study and in an additional 19 of 120 samples analyzed by other agencies. Concentration generally decreased with increasing depth below land surface. Twenty-four of the 33 volatile organic priority pollutants were detected in water from wells sampled during this study. When supplemental data from other agencies are included, tetrachloroethylene concentration exceeded the standard of 5 micrograms/L in water from 49 of 128 wells. No basinwide relation between contamination by these two chemicals and well depth or land use was discerned. A network of 11 observation wells that could be sampled twice a year would enhance the monitoring of changes groundwater quality in the Bunker Hill basin. (USGS)

  15. Ground-water levels and water-quality data for wells in the Spring Creek area near Arnold Air Force Base, Tennessee, April and May 2000

    USGS Publications Warehouse

    Williams, Shannon D.; Aycock, Robert A.

    2001-01-01

    Arnold Air Force Base (AAFB) occupies about 40,000 acres in Coffee and Franklin Counties, Tennessee. Numerous site-specific ground-water contamination investigations have been conducted at designated solid waste management units (SWMU?s) at AAFB. Several synthetic volatile organic compounds (VOC?s), primarily chlorinated solvents, have been identified in groundwater samples collected from monitoring wells near SWMU 8 in the Spring Creek area. During April and May 2000, a study of the groundwater resources in the Spring Creek area was conducted to determine if VOC?s from AAFB have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. The study focused on sampling private wells located within the Spring Creek area that are used as a source of drinking water. Ground-water-flow directions were determined by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 35 private wells and 22 monitoring wells during the period of study. Depths to ground water were determined for 22 of the private wells and all 22 of the monitoring wells. The wells ranged in depth from 21 to 105 feet. Water-level altitudes ranged from 930 to 1,062 feet above sea level. Depths to water ranged from 8 to 83 feet below land surface. Water-quality samples were collected from 29 private wells which draw water from either gravel zones in the upper part of the Manchester aquifer, fractured bedrock in the lower part of the Manchester aquifer, or a combination of these two zones. Concentrations of 50 of the 55 VOC?s analyzed for were less than method detection limits. Chloroform, acetone, chloromethane, 2-butanone, and tetrachloroethylene were detected in concentrations exceeding the method detection limits. Only chloroform and acetone were detected in concentrations equal to or exceeding reporting limits. Chloroform was detected in a sample from one well at a concentration of 1.2 micrograms per liter (?g/L). Acetone was detected in a sample from another well at a concentration of 10 ?g/L. Acetone also was detected in a duplicate sample from the same well at an estimated concentration of 7.2 ?g/L, which is less than the reporting limit for acetone. The only contaminant of concern detected was tetrachloroethylene. Tetrachloroethylene was detected in only one sample, and this detection was at an estimated concentration below the reporting limit. None of the VOC concentrations exceeded drinking water maximum contaminant levels for public water systems.

  16. Dissolving efficacy of different organic solvents on gutta-percha and resilon root canal obturating materials at different immersion time intervals

    PubMed Central

    Mushtaq, Mubashir; Farooq, Riyaz; Ibrahim, Mohammed; Khan, Fayiza Yaqoob

    2012-01-01

    Background Aim: The purpose of this study was to compare and evaluate the dissolving capability of various endodontic solvents used during endodontic retreatment on resilon and gutta-percha at different immersion time intervals. Materials and Methods: 160 ISO no. 40 cones (0.06 taper), 80 each of resilon and gutta-percha were taken as samples for the study. Both resilon and gutta-percha were divided into eight experimental groups of 20 cones (four groups each of resilon and gutta-percha) for immersion in xylene, tetrachloroethylene, refined orange oil and distilled water. Each group was further divided into two equal subgroups (n=10) for 2- and 5-minute immersion time intervals at room temperature to investigate the potential of these solvents for clinical use in dissolving resilon and gutta-percha. Each sample was weighed initially before immersing in the solvent on a digital analytical scale. Distilled water served as a control. Samples were removed from the respective solvents after the specified immersion period and washed in 100 ml of distilled water and allowed to dry for 24 h at 37°C in a humidifier. The samples were then again weighed after immersion in the specific solvent on a digital analytical scale. The extent of gutta-percha or resilon removed from the specimen was calculated from the difference between the original weight of gutta-percha or resilon sample and its final weight. Means and standard deviations of percentage loss of weight were calculated at each time interval for each group of specimens. The values were compared by statistical parametric tests using SPSS 16.0 Software. The data was subjected to paired ‘t‘ test, independent ‘t’ test, one-way ANOVA test and multiple comparisons with Scheffe's test. Results: There was no significance in the amount of gutta-percha dissolved at 2- and 5-minute immersion time intervals in all groups (P>0.05) except the tetrachloroethylene group (P=0.00). There was a very high significance in the amount of resilon dissolved at 2- and 5-minute immersion time intervals in all groups (P=0.00) except the xylene and distilled water (Control) groups (P>0.05). Conclusion: The results showed that xylene, refined orange oil and tetrachloroethylene can be used for softening gutta-percha/resilon during retreatment with various techniques- xylene being the best solvent both for gutta-percha and resilon. PMID:22557812

  17. Neurobehavioural effects of developmental toxicity.

    PubMed

    Grandjean, Philippe; Landrigan, Philip J

    2014-03-01

    Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments, affect millions of children worldwide, and some diagnoses seem to be increasing in frequency. Industrial chemicals that injure the developing brain are among the known causes for this rise in prevalence. In 2006, we did a systematic review and identified five industrial chemicals as developmental neurotoxicants: lead, methylmercury, polychlorinated biphenyls, arsenic, and toluene. Since 2006, epidemiological studies have documented six additional developmental neurotoxicants-manganese, fluoride, chlorpyrifos, dichlorodiphenyltrichloroethane, tetrachloroethylene, and the polybrominated diphenyl ethers. We postulate that even more neurotoxicants remain undiscovered. To control the pandemic of developmental neurotoxicity, we propose a global prevention strategy. Untested chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity. To coordinate these efforts and to accelerate translation of science into prevention, we propose the urgent formation of a new international clearinghouse. PMID:24556010

  18. Mixed Waste Management Facility (MWMF) groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, trichloroethylene, tetrachloroethylene, lead, antimony, I,I-dichloroethylene, 1,2-dichloroethane, gross alpha, mercury, nickel, nitrate, nonvolatile beta, and total alpha-emitting radium (radium-224 and radium-226) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 57 (49%) of the 116 monitored wells contained elevated tritium activities, and 21 (18%) wells exhibited elevated trichloroethylene concentrations Sixty-one downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB[sub 2] (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained constituents that exceeded the PDWS during first quarter 1992. Upgradient wells BGO 1D and HSB 85A, BC, and 85C did not contain any constituents that exceeded the PDWS. Upgradient well BGO 2D contained elevated tritium.

  19. Mixed Waste Management Facility (MWMF) groundwater monitoring report. First quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1992-06-01

    During first quarter 1992, tritium, trichloroethylene, tetrachloroethylene, lead, antimony, I,I-dichloroethylene, 1,2-dichloroethane, gross alpha, mercury, nickel, nitrate, nonvolatile beta, and total alpha-emitting radium (radium-224 and radium-226) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 57 (49%) of the 116 monitored wells contained elevated tritium activities, and 21 (18%) wells exhibited elevated trichloroethylene concentrations Sixty-one downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB{sub 2} (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained constituents that exceeded the PDWS during first quarter 1992. Upgradient wells BGO 1D and HSB 85A, BC, and 85C did not contain any constituents that exceeded the PDWS. Upgradient well BGO 2D contained elevated tritium.

  20. Catalytic incineration of chlorocarbons

    SciTech Connect

    Nguyen, P.; Stern, E.W.; Amundsen, A.R.; Balko, E.N. [Engelhard Corp., Iselin, NJ (United States)

    1993-12-31

    The authors have evaluated the performance of several supported metal and transition metal oxide catalysts for the oxidation of chlorinated hydrocarbons and have developed a proprietary catalyst (VOCat35OHC{sup TM}) which shows excellent activity and stability. Performance data for the oxidative destruction of trichloroethylene (TCE), tetrachloroethylene, methyl chloride, methylene chloride, chlorobenzene and toluene (1000 ppm, 1.5% H{sub 2}O in air, 7500 VHSV) studies show no decrease in activity after 1000 hours at 450{degrees}C and 1000 ppm TCE. Analysis of reactor effluents show formation of CO{sub 2}, HCI and only relatively minor amounts of Cl{sub 2}. Parametric studies using a central composite experimental design produced response surface models for both VOC at and Pt/alumina using mixed streams of TCE and toluene. These allow one to predict conversion levels as well as levels of Cl{sub 2} and CO produced.

  1. Measurements of Al(NO{sub 3}){sub 3} activities in aqueous nitrate solutions

    SciTech Connect

    Chaiko, D.J.; Fredrickson, D.R.; Difilippo, A.A.; Smidt, S.M.; Vandegrift, G.F. [Argonne National Lab., IL (United States); Tasker, I.R. [National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)

    1992-09-01

    Aluminum nitrate activity coefficient obtained by vapor pressure osmometry are compared with activity coefficients derived from nitric acid extraction measurements using Bromley`s correlation. This solvent extraction approach was possible because of the poor extraction of Al{sup 3+}(D{sub Al} {le} 10{sup {minus}3}) by the chosen solvents. The solvent compositions were 0.25M CMPO (octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide) in tetrachloroethylene (TCE) and 0.25M CMPO with 0.75M tributyle phosphate (TBP) in TCE. In both approaches, nitric acid was used to supress the hydrolysis of Al{sup 3+}. At high ionic strengths, the two techniques yielded very similar activity coefficients for Al(NO{sub 3}){sub 3}. However, at intermediate and very low ionic strengths, the two procedures produced activity coefficients which differed considerably from each other. 2 figures, 3 tables, 18 references.

  2. Measurements of Al(NO sub 3 ) sub 3 activities in aqueous nitrate solutions

    SciTech Connect

    Chaiko, D.J.; Fredrickson, D.R.; Difilippo, A.A.; Smidt, S.M.; Vandegrift, G.F. (Argonne National Lab., IL (United States)); Tasker, I.R. (National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States))

    1992-01-01

    Aluminum nitrate activity coefficient obtained by vapor pressure osmometry are compared with activity coefficients derived from nitric acid extraction measurements using Bromley's correlation. This solvent extraction approach was possible because of the poor extraction of Al{sup 3+}(D{sub Al} {le} 10{sup {minus}3}) by the chosen solvents. The solvent compositions were 0.25M CMPO (octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide) in tetrachloroethylene (TCE) and 0.25M CMPO with 0.75M tributyle phosphate (TBP) in TCE. In both approaches, nitric acid was used to supress the hydrolysis of Al{sup 3+}. At high ionic strengths, the two techniques yielded very similar activity coefficients for Al(NO{sub 3}){sub 3}. However, at intermediate and very low ionic strengths, the two procedures produced activity coefficients which differed considerably from each other. 2 figures, 3 tables, 18 references.

  3. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, Terry C. (Augusta, GA); Fliermans, Carl B. (Augusta, GA)

    1995-01-01

    An apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants; an oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth; withholding it periodicially forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene.

  4. TNX Area 1994 Annual Groundwater Monitoring Report

    SciTech Connect

    Chase, J.A.

    1995-05-01

    During 1994, samples from selected wells of well cluster P 26 and the TBG, TNX, XSB, and YSB well series at the TNX Area were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded the final Primary Drinking Water Standards (PDWS). Nitrate and trichloroethylene exceeded the final PDWS most frequently. Five wells in this area currently are part of the Purge Water Containment Program due to high trichloroethylene concentrations. Carbon tetrachloride, gross alpha, nonvolatile beta, and tetrachloroethylene were elevated sporadically in one or more wells during the year. Groundwater flow directions and rates in the Unconfined Aquifer were similar from quarter to quarter during the year.

  5. Transformations of 1- and 2-carbon halogenated aliphatic organic compounds under methanogenic conditions.

    PubMed Central

    Bouwer, E J; McCarty, P L

    1983-01-01

    Several 1- and 2-carbon halogenated aliphatic organic compounds present at low concentrations (less than 100 micrograms/liter) were degraded under methanogenic conditions in batch bacterial cultures and in a continuous-flow methanogenic fixed-film laboratory-scale column. Greater than 90% degradation was observed within a 2-day detention time under continuous-flow methanogenic conditions with acetate as a primary substrate. Carbon-14 measurements indicated that chloroform, carbon tetrachloride, and 1,2-dichloroethane were almost completely oxidized to carbon dioxide, confirming removal by biooxidation. The initial step in the transformations of tetrachloroethylene and 1,1,2,2-tetrachloroethane to nonchlorinated end products appeared to be reductive dechlorination to trichloroethylene and 1,1,2-trichloroethane, respectively. Transformations of the brominated aliphatic compounds appear to be the result of both biological and chemical processes. The data suggest that transformations of halogenated aliphatic compounds can occur under methanogenic conditions in the environment. PMID:6859849

  6. TNX-Area groundwater monitoring report. 1993 Annual report

    SciTech Connect

    Not Available

    1994-05-01

    During 1993, samples from well cluster P 26 and the TBG, TNX, XSB, and YSB well series at the TNX Area were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Seven parameters exceeded the final Primary Drinking Water Standards (PDWS). Dichloromethane (methylene chloride), a common laboratory contaminant, nitrate, and trichloroethylene exceeded PDWS most frequently. Four wells in this area currently are part of the Purge Water Contaminant Program due to high trichloroethylene concentrations. Carbon tetrachloride, gross alpha, lead, and tetrachloroethylene were elevated sporadically in one or more wells during the year. Groundwater flow directions and rates in the Unconfined Aquifer were similar from quarter to quarter during the year.

  7. Thermal decomposition of captan and formation pathways of toxic air pollutants.

    PubMed

    Chen, Kai; Mackie, John C; Kennedy, Eric M; Dlugogorski, Bogdan Z

    2010-06-01

    This study investigates the thermal decomposition of a widely used fungicide, captan, under gas phase conditions, similar to those occurring in fires, cigarette burning, and combustion of biomass treated or contaminated with pesticides. The laboratory-scale apparatus consisted of a plug flow reactor equipped with sampling trains for gaseous, volatile organic compounds (VOC) and condensed products, with analysis performed by Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS), respectively. Under oxidative conditions, the thermal decomposition of captan generated gaseous pollutants including carbon disulfide, thiophosgene, phosgene, and hydrogen cyanide. The VOC analysis revealed the formation of tetrachloroethylene, hexachloroethane, and benzonitrile. Quantum chemical calculations indicated that captan decomposes unimolecularly, via fission of the C-S bond, with the ensuing radicals reacting with O(2). The results of the present study provide an improved understanding of the formation pathways of toxic air pollutants in the accidental or deliberate combustion of captan. PMID:20433167

  8. Mixed Waste Management Facility (MWMF) groundwater monitoring report. Third quarter 1992

    SciTech Connect

    Thompson, C.Y.

    1992-12-01

    During third quarter 1992, 12 constituents exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in one or more groundwater samples from monitoring wells at the Mixed Waste Management Facility and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents: 57 (48%) and 23 (19%) of the 119 monitoring wells contained elevated tritium and trichloroethylene levels, respectively. Elevated constituents were found primarily in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1} (Barnwell/McBean). Elevated constituents also occurred in five Aquifer Unit IIA (Congaree) wells. Upgradient wells BGO 1D and 2D and HSB 85A, 85B, and 85C did not contain any constituents that exceeded the PDWS. Downgradient wells in the three hydrostratigraphic units contained elevated levels of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, gross alpha, lead, nonvolatile beta, thallium, total alpha-emitting radium (radium-224 and radium-226), or cadmium.

  9. Mixed Waste Management Facility (MWMF) groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.

    1992-12-01

    During third quarter 1992, 12 constituents exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in one or more groundwater samples from monitoring wells at the Mixed Waste Management Facility and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents: 57 (48%) and 23 (19%) of the 119 monitoring wells contained elevated tritium and trichloroethylene levels, respectively. Elevated constituents were found primarily in Aquifer Zone IIB[sub 2] (Water Table) and Aquifer Zone IIB[sub 1] (Barnwell/McBean). Elevated constituents also occurred in five Aquifer Unit IIA (Congaree) wells. Upgradient wells BGO 1D and 2D and HSB 85A, 85B, and 85C did not contain any constituents that exceeded the PDWS. Downgradient wells in the three hydrostratigraphic units contained elevated levels of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, gross alpha, lead, nonvolatile beta, thallium, total alpha-emitting radium (radium-224 and radium-226), or cadmium.

  10. Mixed Waste Management Facility (MWMF) groundwater monitoring report. First quarter 1993

    SciTech Connect

    Not Available

    1993-06-01

    During first quarter 1993, eight constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste anagement Facility, the Old Burial Ground, the E-Area Vaults, and the proposed Hazardous Waste/Mixed Waste Disposal Vaults (HWMWDV). As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Tetrachloroethylene, chloroethene, 1,1-dichloroethylene, gross alpha, lead, or nonvolatile beta levels also exceeded standards in one or more wells. The elevated constituents were found primarily in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1}, (Barnwell/McBean) wells. However, several Aquifer Unit IIA (Congaree) wells also contained elevated constituent levels. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to previous quarters.

  11. Mixed Waste Management Facility (MWMF) groundwater monitoring report. Fourth quarter 1993 and 1993 summary

    SciTech Connect

    Butler, C.T.

    1994-03-01

    During fourth quarter 1993, 10 constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility, the Old Burial Ground, the E-Area Vaults, and the proposed Hazardous Waste/Mixed Waste Disposal Vaults. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents. Carbon tetrachloride, chloroform, chloroethane (vinyl chloride), 1,1-dichloroethylene, dichloromethane (methylene chloride), lead, mercury, or tetrachloroethylene also exceeded standards in one or more wells. Elevated constituents were found in numerous Aquifer Zone 2B{sub 2} (Water Table) and Aquifer Zone 2B{sub 1}, (Barnwell/McBean) wells and in two Aquifer Unit 2A (Congaree) wells. The groundwater flow direction and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  12. Method for detecting toxic gases

    DOEpatents

    Stetter, J.R.; Zaromb, S.; Findlay, M.W. Jr.

    1991-10-08

    A method is disclosed which is capable of detecting low concentrations of a pollutant or other component in air or other gas. This method utilizes a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component. An electrochemical sensor responds to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor. 6 figures.

  13. Analysis and evaluation of VOC removal technologies demonstrated at Savannah River

    SciTech Connect

    Chesnut, D.A.; Wagoner, J.; Nitao, J.J.; Boyd, S.; Shaffer, R.J.; Kansa, E.J.; Buscheck, T.A. [Lawrence Livermore National Lab., CA (United States); Pruess, K. [Lawrence Berkeley Lab., CA (United States); Falta, R.W. [Clemson Univ., SC (United States)

    1993-09-01

    Volatile Organic Compounds, or VOCs, are ubiquitous subsurface contaminants at industrial as well as DOE sites. At the Savannah River Plant, the principles VOCs contaminating the subsurface below A-Area and M-Area are Trichloroethylene (C{sub 2}HCl{sub 3}, or TCE) and Tetrachloroethylene (C{sub 2}Cl{sub 4}, or PCE). These compounds were used extensively as degreasing solvents from 1952 until 1979, and the waste solvent which did not evaporate (on the order of 2{times}10{sup 6} pounds) was discharged to a process sewer line leading to the M-Area Seepage Basin (Figure I.2). These compounds infiltrated into the soil and underlying sediments from leaks in the sewer line and elsewhere thereby contaminating the vadose zone between the surface and the water table as well as the aquifer.

  14. Comparison of temporal trends in VOCs as measured with PDB samplers and low-flow sampling methods

    USGS Publications Warehouse

    Harte, P.T.

    2002-01-01

    Analysis of temporal trends in tetrachloroethylene (PCE) concentration determined by two sample techniques showed that passive diffusion bag (pdb) samplers adequately sample the large variation in PCE concentrations at the site. The slopes of the temporal trends in concentrations were comparable between the two techniques, and the pdb sample concentration generally reflected the instantaneous concentration sampled by the low-flow technique. Thus, the pdb samplers provided an appropriate sampling technique for PCE at these wells. One or two wells did not make the case for widespread application of pdb samples at all sites. However, application of pdb samples in some circumstances was appropriate for evaluating temporal and spatial variations in VOC concentrations, thus, should be considered as a useful tool in hydrogeology.

  15. Geohydrology and the occurrence of volatile organic compounds in ground water, Culpeper basin of Prince William County, Virginia

    SciTech Connect

    Nelms, D.L.; Richardson, D.L. (Geological Survey, Richmond, VA (United States))

    1990-01-01

    The Culpeper basin of Prince William County comprises an interbedded sequence of Upper Triassic and Lower Jurassic sedimentary and volcanic rocks. This sequence is intersected by diabase intrusives and thermally metamorphosed rocks. The rocks of the Culpeper basin are highly fractured and overlain by a thin cover of overburden. Groundwater in the Culpeper basin flows generally from the uplands along lineaments to the lowlands or valleys. Pumping from municipal-supply wells has caused two cones of depression in the Manassas-Manassas Park area. Volatile organic compounds have been detected in groundwater in 5 areas of the Culpeper basin in the county. The dominant volatile organic compounds detected are tetrachloroethylene, trichloroethylene, and 1,1,1-trichloroethane. Concentrations of the volatile organic compounds range from 0.1 to 5,300 microg/L. 62 refs., 20 figs., 15 tabs.

  16. NIOSH current intelligence bulletins: summaries

    SciTech Connect

    Not Available

    1988-09-01

    Summaries were offered of the current intelligence bulletins issued from January 20, 1975 to August of 1988. They include information on the following topics: chloroprene, trichloroethylene, ethylene dibromide, chrome pigment, asbestos, hexamethylphosphoric triamide, polychlorinated biphenyls, 4,4'-diaminodiphenylmethane, chloroform, radon daughters, dimethylcarbamoyl chloride, diethylcarbamoyl-chloride, explosive azide hazard, inorganic arsenic, nitrosamines in cutting fluids, metabolic precursors of beta-naphthylamine, 2-nitropropane, acrylonitrile, 2,4-diaminoanisole, tetrachloroethylene, trimellitic anhydride, ethylene thiourea, disulfiram, direct-blue-6, direct-black-38, direct-brown-95, benzidine derived dyes, ethylene dichloride, NIAX catalyst ESN, chloroethanes, vinyl halides, glycidyl ethers, epichlorohydrin, smoking, arsine poisoning, radiofrequency sealers and heaters, formaldehyde, ethylene oxide, silica flour, vibration syndrome, glycol ethers, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,3-butadiene, cadmium, monohalomethanes, dinitrotoluenes, methylene chloride, 4,4'-methylenedianiline, organic solvent neurotoxicity, mechanical power press injuries, and the carcinogenic effects of diesel exhaust.

  17. Current Intelligence Bulletins: summaries, September 1987

    SciTech Connect

    Not Available

    1987-09-01

    Brief summaries of 49 NIOSH Current Intelligence Bulletins were provided in a cumulative listing. Permissible Exposure Limits were included where applicable, and notes were provided with some summaries indicating further action or data since original publication. Topics covered include chloroprene, trichloroethylene, ethylene-dibromide, chrome pigment, asbestos, hexamethylphosphoric-triamide, polychlorinated-biphenyls, 4,4'-diaminodiphenylmethane, chloroform, radon daughters, dimethylcarbamoyl-chloride, diethylcarbamoyl-chloride, explosive azide hazard, arsenic, nitrosamines, metabolic precursors of beta-naphthylamine, 2-nitropropane, acrylonitrile, 2,4-diaminoanisole, tetrachloroethylene, trimellitic-anhydride, ethylene-thiourea, ethylene-dibromide, disulfiram, dyes, ethylene-dichloride, chloroethanes, vinyl halides, glycidyl ethers, epichlorohydrin, smoking, arsine, radiofrequency sealers, formaldehyde, ethylene-oxide, silica flour, vibration syndrome, glycol ethers, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,3-butadiene, cadmium, monohalomethanes, dinitrotoluenes, methylene-chloride, 4,4'-methylenedianiline, organic solvents, and injuries and amputations from working with power presses.

  18. Public health assessment for crossley farm/Hereford groundwater, Hereford township, Berks County, Pennsylvania, Region 3. CERCLIS No. PAD981740061. Preliminary report

    SciTech Connect

    Not Available

    1993-02-01

    The report describes an illegal waste disposal site in east central Pennsylvania and its effect on groundwater in the area surrounding the site. The Crossley Farm (Hereford Groundwater) site is in the Huffs Church community of Hereford Township, Berks County. Illegal waste disposal activities reportedly occurred at the site from the mid-1960's to mid-1970's. About 250 residents live hydrogeological downgradient of the site (within two miles) and another 200 live within one-half mile upgradient of the site. The Pennsylvania Department of Environmental Resources has collected groundwater samples in 1983 and the EPA has collected samples in 1986. The estimated exposures are to substances (trichloroethylene and tetrachloroethylene in particular) in groundwater at concentrations that with long-term exposure can cause adverse health effects to the population.

  19. FY02 Final Report on Phytoremediation of Chlorinated Ethenes in Southern Sector Sediments of the Savannah River Site

    SciTech Connect

    Brigmon, R..L.

    2004-01-30

    This final report details the operations and results of a 3-year Seepline Phytoremediation Project performed adjacent to Tims Branch, which is located in the Southern Sector of the Savannah River Site (SRS) A/M Area. Phytoremediation is a process where interactions between vegetation, associated microorganisms, and the host substrate combine to effectively degrade contaminated soils, sediments, and groundwater. Phytoremediation is a rapidly developing technology that shows promise for the effective and safe cleanup of certain hazardous wastes. It has the potential to remediate numerous volatile organic compounds (VOCs). Extensive characterization work has demonstrated that two VOCs, tetrachloroethylene (PCE) and trichloroethylene (TCE) are the major components of the VOC-contaminated groundwater that is migrating through the Southern Sector and Tims Branch seepline area (WSRC, 1999). The PCE and TCE are chlorinated ethenes (CE), and have been detected in seepline soils and ground water adjacent to the ecologically-sensitive Tims Branch seepline area.

  20. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1994-01-01

    Disclosed is an apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid (NF) is selected to simulated the growth and reproduction of indigenous subsurface microorganisms capable of degrading the contaminants; an oxygenated fluid (OF) is selected to create an aerobic environment with anaerobic pockets. NF is injected periodically while OF is injected continuously and both are extracted so that both are drawn across the plume. NF stimulates microbial colony growth; withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is acceptable. NF can be methane and OF be air, for stimulating production of methanotrophs to break down chlorohydrocarbons, especially TCE and tetrachloroethylene.

  1. Survey of subsurface treatment technologies for environmental restoration sites at Sandia National Laboratories, New Mexico.

    SciTech Connect

    McGrath, Lucas K.; Ho, Clifford Kuofei; Wright, Jerome L.

    2003-08-01

    This report provides a survey of remediation and treatment technologies for contaminants of concern at environmental restoration (ER) sites at Sandia National Laboratories, New Mexico. The sites that were evaluated include the Tijeras Arroyo Groundwater, Technical Area V, and Canyons sites. The primary contaminants of concern at these sites include trichloroethylene (TCE), tetrachloroethylene (PCE), and nitrate in groundwater. Due to the low contaminant concentrations (close to regulatory limits) and significant depths to groundwater ({approx}500 feet) at these sites, few in-situ remediation technologies are applicable. The most applicable treatment technologies include monitored natural attenuation and enhanced bioremediation/denitrification to reduce the concentrations of TCE, PCE, and nitrate in the groundwater. Stripping technologies to remove chlorinated solvents and other volatile organic compounds from the vadose zone can also be implemented, if needed.

  2. Quarterly sampling of the wetlands along the old F-Area effluent ditch: August 1994. Revision 1

    SciTech Connect

    Cummins, C.L.; Dixon, K.L.

    1994-08-01

    In August 1994, well point water and near-surface water samples were collected to further characterize tritium and volatile organic compounds in the Wetlands along the old F-Area effluent ditch south of 643-E at the Savannah River Plant. Well point samples were collected from seven locations and near-surface water samples were collected at four locations. Results of the August 1994 sampling event further support findings that tritium and volatile organic compounds are outcropping in the Wetlands near the old F-area effluent ditch. Four analytes (1,2-dichloroethylene, trichloroethylene, tritium, and vinyl chloride) were detected at least once at concentrations above the primary Drinking Water Standards or the Maximum Contaminant Levels. Five analytes (the above chemicals plus tetrachloroethylene) were detected at least once in the near-surface water samples at concentrations greater than the method detection limit.

  3. Mutagenicity testing of condensates of smoke from titanium dioxide/hexachloroethane and zinc/hexachloroethane pyrotechnic mixtures.

    PubMed

    Karlsson, N; Fängmark, I; Häggqvist, I; Karlsson, B; Rittfeldt, L; Marchner, H

    1991-05-01

    Condensates of smoke from titanium dioxide/hexachloroethane and zinc/hexachloroethane pyrotechnic mixtures were investigated for their potential to produce genetic damage in the tester strains TA98, TA100, TA1535 and TA1537 of Salmonella typhimurium and in the mouse bone marrow micronucleus assay. Both smoke condensates contained several chlorinated hydrocarbons among which tetrachloroethylene, hexachloroethane, hexachlorobutadiene and hexachlorobenzene were identified by GC/MS. Condensate of smoke from titanium dioxide/hexachloroethane showed a dose-related positive response in the Salmonella assay with strains TA98 and TA100 in the absence of metabolic activation from rat liver S9 fraction. Both smoke condensates were negative in the micronucleus assay but produced a small but significant depression of erythropoietic activity. The results indicate that smoke condensate from titanium dioxide/hexachloroethane mixtures contains unidentified compound(s) that may be considered mutagenic in the Salmonella assay. PMID:2027339

  4. Competitive Sorption and Desorption of Chlorinated Organic Solvents (DNAPLs) in Engineered Natural Organic Matter

    SciTech Connect

    Tang, Jixin; Weber, Walter J., Jr.

    2004-03-31

    The effects of artificially accelerated geochemical condensation and maturation of natural organic matter on the sorption and desorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) were studied. The sorption and desorption of TCE in the presence and absence of the competing PCE and 1,2-dichlorobenzene (DCB) were also examined. A sphagnum peat comprising geologically young organic matter was artificially ''aged'' using superheated water, thus increasing the aromaticity and the degree of condensation of its associated organic matter. The sorption of all solutes tested were increased remarkably and their respective desorptions reduced, by the aged peat. The sorption capacities and isotherm nonlinearities of the peat for both TCE and PCE were found to increase as treatment temperature increased. In the competitive sorption studies, both PCE and DCB were found to depress TCE sorption, with PCE having greater effects than DCB, presumably because the molecular structure o f the former is more similar to that of TCE.

  5. Bias in biologic monitoring caused by concomitant medication

    SciTech Connect

    Borm, P.J.; de Barbanson, B.

    1988-03-01

    Medication of the worker with pharmacotherapeutic agents and its meaning for individual pharmacokinetics of the agent(s) to which the worker is exposed is a largely unexplored zone, on the border of both occupational and clinical medicine. Medication and exposure to occupational agents can result in pharmacodynamic and/or pharmacokinetic interactions; the latter type of interactions will be discussed in this paper. Using styrene, toluene, tetrachloroethylene, and 1,1,1-trichloroethane as examples of solvents with various kinetic properties, it is demonstrated in what way concomitant therapy can influence the elimination of the solvent. Major emphasis is laid on the effects on conclusions drawn from biomonitoring studies in exhaled air and venous blood. To achieve this purpose, a physiologic simulation model, run on a 640-kilobyte microcomputer, is used. The simulated variation of several parameters is illustrated with examples from pharmacologic practice. 45 references.

  6. Groundwater contamination by PCE and TCE: ATSDR's approach to evaluating public health hazard

    SciTech Connect

    Weis, B.K.; Susten, A.S.

    1999-07-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) conducts public health assessments and consultations that evaluate the potential health impacts from human exposure to hazardous substances and recommend appropriate actions needed to mitigate or prevent exposures. ATSDR has conducted health evaluations for more than 80 federal facilities. Eighteen sites involve human exposure to tetrachloroethylene (PCE) or trichloroethylene (TCE) in groundwater. ATSDR uses a two-tiered approach to evaluate health hazard or risk from exposure. The first tier of analysis is described as a rote algorithmic determination of risk (RAD) and is used to screen exposure conditions that do not pose a health hazard under conservative assumptions of exposure. The second tier is a weight-of-evidence analysis that incorporates the traditional elements of risk assessment within the broader context of professional and biomedical health hazard for exposure pathways involving groundwater contamination at federal facilities.

  7. Mixed Waste Management Facility groundwater monitoring report, First quarter 1994

    SciTech Connect

    Not Available

    1994-06-01

    During first quarter 1994, nine constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility, the Old Burial Ground, the E-Area Vaults, the proposed Hazardous Waste/Mixed Waste Disposal Vaults, and the F-Area Sewage Sludge Application Site. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents. Chloroethene (vinyl chloride), copper, 1,1-dichloroethylene, lead, mercury, nonvolatile beta, or tetrachloroethylene also exceeded standards in one or more wells. Elevated constituents were found in numerous Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1}, (Barnwell/McBean) wells and in one Aquifer Unit IIA (Congaree) well. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  8. Sanitary landfill groundwater monitoring report. Fourth quarter 1994 and 1994 summary

    SciTech Connect

    NONE

    1995-02-01

    Eighty-nine wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Waste Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Dichloromethane, a common laboratory contaminant, and trichloroethylene were the most widespread constituents exceeding standards during 1994. Benzene, chloroethene (vinyl chloride), 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloropropane, gross alpha, mercury, nonvolatile beta, tetrachloroethylene, and tritium also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 140 ft/year during first and fourth quarters 1994.

  9. Mixed waste management facility groundwater monitoring report. Fourth quarter 1995 and 1995 summary

    SciTech Connect

    NONE

    1996-03-01

    During fourth quarter 1995, seven constituents exceeded final Primary Drinking Water Standards (PDWS) in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility. No constituents exceeded final PDWS in samples from the upgradient monitoring wells. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents. Chloroethene, gross alpha, lead, mercury, and tetrachloroethylene also exceeded final PDWS in one or more wells. Elevated constituents were found in numerous Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1} (Barnwell/McBean) wells and in three Aquifer Unit IIA (Congaree) wells. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  10. Mixed waste management facility groundwater monitoring report. Fourth quarter 1996 and 1996 summary

    SciTech Connect

    NONE

    1997-03-01

    During fourth quarter 1996, nine constituents exceeded final Primary Drinking Water Standards (PDWS) in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility. No constituents exceeded final PDWS in samples from the upgradient monitoring wells. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents. Carbon tetrachloride, chloroethene, chloroform, 1,1-dichloroethylene, dichloromethane, gross alpha, and tetrachloroethylene also exceeded final PDWS in one or more wells. Elevated constituents were found in numerous Aquifer Zone llB2 (Water Table) and Aquifer Zone llB1 (Barnwell/McBean) wells and in six Aquifer Unit IIA (Congaree) wells. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  11. Mixed Waste Management Facility (MWMF) groundwater monitoring report: Third quarter 1993

    SciTech Connect

    Not Available

    1993-12-01

    During third quarter 1993, eight constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility, the Old Burial Ground, the E-Area Vaults, and the proposed Hazardous Waste/Mixed Waste Disposal Vaults. As in previous quarters, tritium and trichloroethylene were the most widespread constituents Chloroethene (vinyl chloride), 1,1-dichloroethylene, dichloromethane (methylene chloride), lead, mercury, or tetrachloroethylene also exceeded standards in one or more wells. The elevated constituents were found in Aquifer Zone IIB{sub 2} (Water Table) and Aquifer Zone IIB{sub 1} (Barnwell/McBean) wells. No elevated constituents were exhibited in Aquifer Unit IIA (Congaree) wells. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  12. Sanitary Landfill groundwater monitoring report. Fourth quarterly report and summary 1993

    SciTech Connect

    Not Available

    1994-02-01

    Fifty-seven wells of the LFW series monitor groundwater quality in Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Waste Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Dichloromethane a common laboratory contaminant, and trichloroethylene were the most widespread constituents exceeding standards during 1993. Benzene, chlorobenzene, chloroethene 1,2 dichloroethane, 1,1-dichloroethylene, 1,2-dichloropropane, gross alpha, lindane, mercury, tetrachloroethylene, and tritium also exceeded standards in one or more wells. No groundwater contaminants were observed in wells screened in the lower section of Steed Pond Aquifer.

  13. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. First quarter 1993

    SciTech Connect

    Not Available

    1993-06-01

    During first quarter 1993, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Nine parameters exceeded standards during the quarter. As in fourth quarter 1992, tetrachloroethylene and trichloroethylene exceeded the final Primary Drinking Water Standards in 4 and 7 wells, respectively. Dichloromethane (methylene chloride), not previously compared to a standard in the Savannah River Site Groundwater Monitoring Program, was elevated in one well. Aluminum, iron, manganese, pH, specific conductance, and total organic halogens exceeded the Savannah River Site Flag 2 criteria; all of these parameters, with the exception of aluminum, were reported as elevated in AMB wells during previous quarters. Groundwater flow directions and rates in the water-table unit and the upper section of the Congaree were similar to previous quarters.

  14. Method for detecting toxic gases

    DOEpatents

    Stetter, Joseph R. (Naperville, IL); Zaromb, Solomon (Hinsdale, IL); Findlay, Jr., Melvin W. (Bolingbrook, IL)

    1991-01-01

    A method capable of detecting low concentrations of a pollutant or other component in air or other gas, utilizing a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component, and an electrochemical sensor responsive to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor.

  15. In-situ radio frequency heating for remediation of soil and groundwater contamination

    SciTech Connect

    Kasevich, R.S.; Price, S.L. [KAI Technologies, Inc., Portsmouth, NH (United States); Wiberg, D.; Johnson, M. [DAHL & Associates, Inc., St Paul, MN (United States)

    1997-12-31

    Results from a field demonstration and a bench-scale study verify Radio Frequency Heating`s (RFH) ability to enhance Soil Vapor Extraction (SVE) and air sparging. During the spring 1996 demonstration in Blaine, Minnesota, at the site of a former gasoline station, a remotely operated, computer-controlled RFH system was used to supply 2,300 kilowatt-hours of RF energy to soil and groundwater over a three-week period, raising temperatures and significantly increasing the removal rate of gasoline constituents (primarily benzene, ethyl benzene, toluene and xylene - BTEX) compared to the baseline (ambient temperature) removal rate. Analysis of data from a bench-scale study which compared removal rates of tetrachloroethylene (PCE) from soil by ambient temperature air flow and by RFH (90{degrees}C soil temperature) air flow also reveals a notable increase in removal rate when RFH is employed.

  16. Photodegradation of the indoor organic pollutants by UV irradiation using TiO2 catalysts

    NASA Astrophysics Data System (ADS)

    Glajar, Ioana C.; Moldovan, Z.

    2009-08-01

    Volatile organic compounds (VOCs) are a major environmental concern, because of their carcinogenic and toxic effects on human health. The most frequent types of VOCs found in indoor air are, according to literature, Choloroform, p-dichlorbenzene, tetrachloroethylene, formaldehyde, NOx. Another VOCs found very often mentioned in the literature are ethanol and acetone or BTEX compounds. The investigated compounds used in this work for studding the photodegradation effect are toluene and cholorobenzene. In the present work were calculated the photodegradation rates of the compounds mentioned above using UV radiation and TiO2, as catalyst. The obtained results are discussed based on comparative values of removal quantities for few time intervals for different types of catalysts based on TiO2 aerogel.

  17. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Second quarter 1994

    SciTech Connect

    Not Available

    1994-09-01

    During second quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Three parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards. Total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria in two of the wells. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to previous quarters. During second quarter 1994, SRS received SCDHEC approval for five point-of-compliance wells and two plume definition wells near the Met Lab HWMF. Field work has begun on this project.

  18. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1995-01-24

    An apparatus and method are described for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants. An oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth. Withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene. 3 figures.

  19. Sanitary Landfill Groundwater Monitoring Report. Fourth Quarter 1997 and 1997 Summary

    SciTech Connect

    Chase, J. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1998-02-01

    A maximum of forty-eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Water Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Chloroethene (vinyl chloride) and trichloroethylene were the most widespread constituents exceeding standards during 1997. Lead (total recoverable), 1,4-dichlorobenzene, mercury, benzene, dichloromethane (methylene chloride), a common laboratory contaminant, tetrachloroethylene, 1,2-dichloroethane, gross alpha, tritium, and 1.2-dichloropropane also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 139 ft/year during first quarter 1997 and 132 ft/year during fourth quarter.

  20. Risk assessment of seeps from the 317 Area of Argonne National Laboratory

    SciTech Connect

    NONE

    1996-09-17

    Chlorinated hydrocarbon contaminants have recently been detected in groundwater seeps on forest preserve property south of the 317 Area at ANL. The 317 Area is near ANL`s southern boundary and is considered the source of the contamination. Five seeps are about 200 m south of the ANL property line and about same distance from the nearest developed trails in the forest preserve. Conservative assumptions were used to assess the possibility of adverse health effects associated with forest preserve seeps impacted by the 317 Area. Results indicate that neither cancer risks nor noncarcinogenic effects associated with exposures to seep contaminants are a concern; thus, the area is safe for all visitors. The ecological impact study found that the presence of the three contaminants (CCl{sub 4}, CHCl{sub 3}, tetrachloroethylene) in the seep water does not pose a risk to biota in the area.

  1. Investigation of the behavior of VOCs in ground water across fine- and coarse-grained geological contacts using a medium-scale physical model

    SciTech Connect

    Hoffman, F.; Chiarappa, M.L.

    1998-03-01

    One of the serious impediments to the remediation of ground water contaminated with volatile organic compounds (VOCs) is that the VOCs are retarded with respect to the movement of the ground water. Although the processes that result in VOC retardation are poorly understood, we have developed a conceptual model that includes several retarding mechanisms. These include adsorption to inorganic surfaces, absorption to organic carbon, and diffusion into areas of immobile waters. This project was designed to evaluate the relative contributions of these mechanisms; by improving our understanding, we hope to inspire new remediation technologies or approaches. Our project consisted of a series of column experiments designed to measure the retardation, in different geological media, of four common ground water VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) which have differing physical and chemical characteristics. It also included a series of diffusion parameters that constrain the model, we compared the data from these experiments to the output of a computational model.

  2. Alloyed steel wastes utilization

    SciTech Connect

    Sokol, I.V. [Russian Academy of Sciences, Khabarovsk (Russian Federation). Inst. of Materials

    1995-12-31

    Alloyed steel chips and swarf formed during metal processing are looked upon as additional raw materials in metallurgical production. This paper presents some new methods for steel waste chips and swarf cleaning. One of them is swarf and steel chips cleaning in tetrachloroethylene with ultrasonic assistance and solvent regeneration. Thermal cleaning of waste chips and swarf provides off gas products utilization. The catalyst influence of the metal surface on the thermal decomposition of liquid hydrocarbons during the cleaning process has been studied. It has been determined that the efficiency of this metal waste cleaning technique depends on the storage time of the swarf. The waste chips and swarf cleaning procedures have been proven to be economically advantageous and environmentally appropriate.

  3. Evaluation of exposure to contaminated drinking water and specific birth defects and childhood cancers at Marine Corps Base Camp Lejeune, North Carolina: a case–control study

    PubMed Central

    2013-01-01

    Background Drinking water supplies at Marine Corps Base Camp Lejeune were contaminated with trichloroethylene, tetrachloroethylene, benzene, vinyl chloride and trans-1,2-dichloroethylene during 1968 through 1985. Methods We conducted a case control study to determine if children born during 1968–1985 to mothers with residential exposure to contaminated drinking water at Camp Lejeune during pregnancy were more likely to have childhood hematopoietic cancers, neural tube defects (NTDs), or oral clefts. For cancers, exposures during the first year of life were also evaluated. Cases and controls were identified through a survey of parents residing on base during pregnancy and confirmed by medical records. Controls were randomly sampled from surveyed participants who had a live birth without a major birth defect or childhood cancer. Groundwater contaminant fate and transport and distribution system models provided estimates of monthly levels of drinking water contaminants at mothers’ residences. Magnitude of odds ratios (ORs) was used to assess associations. Confidence intervals (CIs) were used to indicate precision of ORs. We evaluated parental characteristics and pregnancy history to assess potential confounding. Results Confounding was negligible so unadjusted results were presented. For NTDs and average 1st trimester exposures, ORs for any benzene exposure and for trichloroethylene above 5 parts per billion were 4.1 (95% CI: 1.4-12.0) and 2.4 (95% CI: 0.6-9.6), respectively. For trichloroethylene, a monotonic exposure response relationship was observed. For childhood cancers and average 1st trimester exposures, ORs for any tetrachloroethylene exposure and any vinyl chloride exposure were 1.6 (95% CI: 0.5-4.8), and 1.6 (95% CI: 0.5-4.7), respectively. The study found no evidence suggesting any other associations between outcomes and exposures. Conclusion Although CIs were wide, ORs suggested associations between drinking water contaminants and NTDs. ORs suggested weaker associations with childhood hematopoietic cancers. PMID:24304547

  4. Historical review on development of environmental quality standards and guideline values for air pollutants in Japan.

    PubMed

    Kawamoto, Toshihiro; Pham, Thi-Thu-Phuong; Matsuda, Takayuki; Oyama, Tsunehiro; Tanaka, Masayuki; Yu, Hsu-Sheng; Uchiyama, Iwao

    2011-07-01

    Environmental quality standards (EQSs) have been established as desirable levels to be maintained for protection of human health and the conservation of the living environment by Basic Environment Law. EQSs in ambient air had been set for 10 substances (sulfur dioxide (SO(2)), carbon monoxide (CO), suspended particulate matter (SPM), nitrogen dioxide (NO(2)) and photochemical oxidants (Ox), benzene, tetrachloroethylene, trichloroethylene, dioxins and dichloromethane) and guideline values for 7 (acrylonitorile, vinyl chloride monomer, mercury, nickel compounds, 1,3-butadiene, chloroform and 1,2-dichloromethane) in Japan by 2009. EQSs for the classical (or traditional) air pollutants, SO(2), CO, SPM, NO(2) and Ox, were set according to the minimal requirement to protect human health, based on evidence from epidemiological studies conducted before the 1970s. In 1996, the Central Environment Council designated substances which may be hazardous air pollutants and substances requiring priority action, and adopted the concept of risk assessment to set EQSs and guideline values. A life-long risk level (virtually safe dose) of 10(-5) was used to set EQS for benzene, and guideline values for vinyl chloride monomer, nickel compounds, and 1,3-butadiene. EQSs for trichloroethylene, tetrachloroethylene and dichloromethane, and guideline values for acrylonitorile and mercury were set using uncertain factors and lowest observed adverse effect (LOAEL)/no observed adverse effect level (NOAEL). The results of animal experiments were utilized to set guideline values for chloroform and 1,2-dichloroethane. The benchmark approach and human equivalent concentration (HEC) were adopted for 1,2-dichloroethane. The history of setting EQSs and guideline values for hazardous air pollutants is one of adopting new concepts into risk assessment. PMID:21680244

  5. Biological degradation of VCCs and CFCs under simulated anaerobic landfill conditions in laboratory test digesters.

    PubMed

    Deipser, A; Stegmann, R

    1997-01-01

    The biological degradation of volatile halogenated hydrocarbons (chlorocarbons (VCCs) and chlorofluorocarbons (CFCs)) was investigated under simulated conditions of landfills in laboratory test digesters. Fully halogenated VCCs (tetrachloroethylene, 1,1,1-trichloroethane, tetrachloromethane and dichloromethane) and CFCs (trichlorofluoromethane (R11), dichlorodifluoromethane (R12) and 1,1,2-trichlorotrifluoroethane (R113)) were degraded under anaerobic conditions in addition to the methanogenic bacteria in municipal solid waste (MSW) and organic wastes. These substances showed different degradation reactions in the simulated acid and methanephases of MSW landfills. It is assumed that R11 and R113 could be decomposed completely under methanogenic conditions. Dichlorofluoromethane (R21) was observed as the reductive degradation product of R11 and was further degraded during the methanephase, but hardly at all under acid conditions. Chlorodifluoromerhane (R22) as a degradation product of R12 was not degraded, even not in the methanephase. In the acidphase, R11 was the only CFC to be dechlorinated, although only in small quantities. The degradation products of tetrachloroethylene differed under the various environmental conditions. In the acidphase, 1,1-dichloroethylene was detected as the only dichloroethylene, whereas in particular cis-1,2-dichloroethylene but also trans-1,2-dichloroethylene, 1,1-dichloroethylene and vinyl chloride could be detected as metabolites in the methanephase. Dichloromethane and chloroethane, as metabolites of 1,1,1-trichloroethane, could hardly be degraded at all in the acidphase. The degradation of VCCs and CFCs is largely independent of the substrate used. The investigations have demonstrated that the measured biodegradation rates (0.3-15 mg/m(3) (material vol)./h) cannot be improved considerably since they are limited by the inhibiting effect of the substances and their degradation products. PMID:19005803

  6. Quarterly sampling of the wetlands along the old F-Area effluent ditch: March 1994

    SciTech Connect

    Dixon, K.L.; Cummins, C.L.; Rogers, V.A.

    1994-05-01

    In March 1994, well point water and near surface water (bucket) samples were collected to further characterize tritium and volatile organic compounds (VOC) in the wetlands along the old F-Area effluent ditch south of 643-E (old burial ground). Groundwater flow paths suggest that compounds detected in water table wells around 643-E would migrate towards the old F-Area effluent ditch and Fourmile Branch. Recent analytical results from near surface water sampling in the wetlands that comprise the old F-Area effluent ditch have shown that tritium and small quantities of VOCs are outcropping in the area. Results of the March 1994 sampling event further support findings that tritium and volatile organic compounds originating from 643-E are outcropping in the wetlands near the old F-Area effluent ditch. Six different analytes were detected in the well points at least once at concentrations greater than the method detection limit: d 1,2-dichloroethylene, acetone, methyl ethyl ketone, tetrachloroethylene, trichloroethylene, and tritium. 1,2-dichloroethylene, tetrachloroethylene, trichloroethylene, and tritium were detected at levels above Primary Drinking Water Standards or Maximum Contaminant Levels list. Four analytes, 1,2-dichloroethylene, trichloroethylene, tritium, and vinyl chloride, were detected at least once at concentrations greater than the method detection limit and least once at concentrations above the PDWS or the MCL. Based on differences in tritium concentrations at each location, it was determined that the sampling devices intercepted different groundwater flow paths. This negated direct comparison of analytical results between devices. However, when VOC concentrations measured at each well point and bucket location were normalized, resulting well point and bucket VOC concentrations were comparable in most cases. These results suggest that volatilization losses of VOCs from the buckets were negligible.

  7. Ground-water contamination in East Bay Township, Michigan

    USGS Publications Warehouse

    Twenter, F.R.; Cummings, T.R.; Grannemann, N.G.

    1985-01-01

    Glacial deposits, as much as 360 feet thick, underlie the study area. The upper 29 to 118 feet, a sand and gravel unit, is the aquifer tapped by all wells in the area. This unit is underlain by impermeable clay that is at least 100 feet thick. Ground-water flow is northeastward at an estimated rate of 2 to 5 feet per day. Hydraulic conductivities in the aquifer range from 85 to 250 feet per day; 120 feet per day provided the best match of field data in a ground-water flow model. The depth to water ranged from 1 to 20 feet. Chemical analyses indicate that ground water is contaminated with organic chemicals from near the Hangar/Administration building at the U.S. Coast Guard Air Station at East Bay, about 4,300 feet northeast. The plume, which follows ground-water flow lines, ranges from 180 to 400 feet wide. In the upper reach of the plume, hydrocarbons less dense than water occur at the surface of the water table; they move downward in the aquifer as they move toward east Bay. Maximum concentrations of the major organic compounds include: benzene, 3,390 ug/L; toluene, 55,500 ug/L; xylene, 3,900 ug/L, tetrachloroethylene, 3,410 ug/L; amd bis (2-ethyl hexyl) phthalate, 2,100 ug/L. Soils are generally free of these hydrocarbons; however, in the vicinity of past drum storage, aircraft maintenance operations, and fuel storage and dispensing , as much as 1,100 ug/kg of tetrachloroethylene and 1,500 ug/kg of bis (-ethyl hexyl) phthalate were detected. At a few locations higher molecular weight hydrocarbons, characteristic of petroleum distillates were found. (USGS)

  8. P-Area Reactor 1993 annual groundwater monitoring report

    SciTech Connect

    NONE

    1994-11-01

    Groundwater was sampled and analyzed during 1993 from wells monitoring the water table at the following locations in P Area: well P 24A in the eastern section of P Area, the P-Area Acid/Caustic Basin, the P-Area Coal Pile Runoff Containment Basin, the P-Area Disassembly Basin, the P-Area Burning/Rubble Pit, and the P-Area Seepage Basins. During 1993, pH was above its alkaline standard in well P 24A. Specific conductance was above its standard in one well each from the PAC and PCB series. Lead exceeded its 50 {mu}g/L standard in one well of the PDB series during one quarter. Tetrachloroethylene and trichloroethylene were detected above their final primary drinking water standards in one well of the PRP well series. Tritium was consistently above its DWS in the PDB and PSB series. Also during 1993, radium-228 exceeded the DWS for total radium in three wells of the PAC series and one well of the PCB series; total alpha-emitting radium exceeded the same standard in a different PCB well. These results are fairly consistent with those from previous years. Unlike results from past years, however, no halogenated volatiles other than trichloroethylene and tetrachloroethylene exceeded DWS in the PRP well series although gas chromatographic volatile organic analyses were performed throughout the year. Some of the regulated units in P Area appear to need additional monitoring by new wells because there are insufficient downgradient wells, sometimes because the original well network, installed prior to regulation, included sidegradient rather than downgradient wells. No monitoring wells had been installed through 1993 at one of the RCRA/CERCLA units named in the Federal Facilities Agreement, the Bingham Pump Outage Pits.

  9. The relation between narrow-dispersed microcapsules and surfactants.

    PubMed

    Guo, H L; Zhao, X P; Wang, J P

    2005-12-01

    Electric ink display is one of the prospect technologies in paper-like display. In this paper, electric ink microcapsules are prepared by means of an in situ polymerization and complex coacervation. In order to obtain the microcapsules in a uniform size distribution, this study focused on the inter-facial tension between tetrachloroethylene and water solution, the dispersion of the core droplets and the microencapsulation with different kind of surfactants. By measuring the inter-facial tensions between water and tetrachloroethylene, it is found that urea-formaldehyde (UF) pre-polymer presents certain surface activity due to the inter-facial tension descending from 43 mN m(-1) to 35 mN m(-1). Because the surface activity of pre-polymer is not valid, the water-soluble emulsifiers can occupy on the surface of the droplets and prevent the UF resin depositing there. The analysis of the size distribution shows that the UF microcapsules are multi-dispersed. Furthermore, the influence of anionic surfactant of SDS on the size distribution of the core droplets is also investigated. The average diameters of the core droplets prepared with 0.005 wt% and 0.012 wt% SDS are approximately 50 microm and 28 microm, respectively. That reveals the existence of SDS not only decreases the droplet diameters, but also makes the size distribution centralized. Because the surface of the core droplets is charged due to the absorption of SDS anionic, the Gelatin and Gum Arabic (GA) coacervating layer is easy to form there. The size of the GA microcapsules prepared with 0.003 wt% SDS is approximately 65 microm. Finally; the responsive behaviour of the microcapsules to electric field is also investigated. PMID:16423757

  10. Volatile organic compounds detected in vapor-diffusion samplers placed in sediments along and near the shoreline at Allen Harbor Landfill and Calf Pasture Point, Davisville, Rhode Island, March-April 1998

    USGS Publications Warehouse

    Lyford, F.P.; Kliever, J.D.; Scott, Clifford

    1999-01-01

    Volatile organic compounds are present in ground water at the Allen Harbor Landfill and the Calf Pasture Point sites on the former Naval Construction Battalion Center in Davisville, R.I. Vapor-diffusion samplers were used at the two sites during March-April 1998 to identify possible discharge points for contaminants along the shore of Allen Harbor and in two wetland areas near the shore. Results from vapor-diffusion samplers will be used in conjunction with other site information to evaluate proposed ground-water monitoring programs. Volatile organic compounds were detected in 41 of 115 samplers placed along the shoreline at the Allen Harbor Landfill. Trichloroethylene was the principal volatile organic compound detected of eight target compounds. The highest vapor concentration measured exceeded 300,000 parts per billion by volume in an area where TCE was detected in groundwater from nearby monitoring wells. Other chemicals detected in vapor-diffusion samplers included tetrachloroethylene, toluene, and benzene. Concentrations of individual volatile organic compounds were less than 100 parts per billion by volume in most samplers. Volatile organic compounds, principally trichloroethylene, were detected in 7 of 30 samplers placed along the shoreline at Calf Pasture Point; the highest trichloroethylene concentration was 1,900 parts per billion by volume. A trace concentration of tetrachloroethylene was detected in one of the samplers. One of 24 samplers placed in two wetland areas near the shore (suspected discharge areas for ground-water containing volatile organic compounds) detected trichloroethylene at a vapor concentration of 14 parts per billion by volume.

  11. Evaluation of the atmosphere as a source of volatile organic compounds in shallow groundwater

    USGS Publications Warehouse

    Baehr, A.L.; Stackelberg, P.E.

    1999-01-01

    The atmosphere as a source of volatile organic compounds (VOCs) in shallow groundwater was evaluated over an area in southern New Jersey. Chloroform, methyl tertbutyl ether (MTBE), 1,1,1-trichloroethane, tetrachloroethylene (PCE), and carbon disulfide (not a VOC) were detected frequently at low-level concentrations in a network of 78 shallow wells in the surficial Kirkwood-Cohansey aquifer system. The atmosphere was sampled for these compounds and only MTBE concentrations were high enough to potentially explain frequent detection in shallow groundwater. A mathematical model of reactive transport through the unsaturated zone is presented to explain how variations in unsaturated properties across the study area could explain differences in MTBE concentrations in shallow groundwater given the atmosphere as the source. Even when concentrations of VOCs in groundwater are low compared to regulatory concentration limits, it is critical to know the source. If the VOCs originate from a point source(s), concentrations in groundwater could potentially increase over time to levels of concern as groundwater plumes evolve, whereas if the atmosphere is the source, then groundwater concentrations would be expected to remain at low-level concentrations not exceeding those in equilibrium with atmospheric concentrations. This is the first analysis of VOC occurrence in shallow groundwater involving colocated atmosphere data.The atmosphere as a source of volatile organic compounds (VOCs) in shallow groundwater was evaluated over an area in southern New Jersey. Chloroform, methyl tert-butyl ether (MTBE), 1,1,1-trichloroethane, tetrachloroethylene (PCE), and carbon disulfide (not a VOC) were detected frequently at low-level concentrations in a network of 78 shallow wells in the surficial Kirkwood-Cohansey aquifer system. The atmosphere was sampled for these compounds and only MTBE concentrations were high enough to potentially explain frequent detection in shallow groundwater. A mathematical model of reactive transport through the unsaturated zone is presented to explain how variations in unsaturated properties across the study area could explain differences in MTBE concentrations in shallow groundwater given the atmosphere as the source. Even when concentrations of VOCs in groundwater are low compared to regulatory concentration limits, it is critical to know the source. If the VOCs originate from a point source(s), concentrations in groundwater could potentially increase over time to levels of concern as groundwater plumes evolve, whereas if the atmosphere is the source, then groundwater concentrations would be expected to remain at low-level concentrations not exceeding those in equilibrium with atmospheric concentrations. This is the first analysis of VOC occurrence in shallow groundwater involving collocated atmosphere data.

  12. Measurements of reactive chlorocarbons over the Surinam tropical rain forest: indications for strong biogenic emissions

    NASA Astrophysics Data System (ADS)

    Scheeren, H. A.; Lelieveld, J.; Williams, J.; Fischer, H.; Warneke, C.

    2003-10-01

    Contrary to the understanding of the emissions and chemical behavior of halocarbons from anthropogenic sources (e.g. CFCs and HCFCs), the biogeochemistry of naturally emitted halocarbons is still poorly understood. We present measurements of chloromethane (methyl chloride, CH3Cl), trichloromethane (chloroform, CHCl3), dichloromethane (CH2Cl2), and tetrachloroethylene (C2Cl4) from air samples taken over the Surinam rainforest during the 1998 LBA/CLAIRE campaign. The samples were collected in stainless steel canisters on-board a Cessna Citation jet aircraft and analyzed in the laboratory using a gas chromatograph equipped with FID and ECD. The chlorocarbons we studied have atmospheric lifetimes of ~1 year or less, and appear to have significant emissions from natural sources including oceans, soils and vegetations, as well as biomass burning. These sources are primarily concentrated in the tropics (30º N-30º S). We detected an increase as a function of latitude of methyl chloride, chloroform, and tetrachloroethylene mixing ratios, in pristine air masses advected from the Atlantic Ocean toward the central Amazon. In the absence of significant biomass burning sources, we attribute this increase to biogenic emissions from the Surinam rainforest. From our measurements, we deduce fluxes from the Surinam rainforest of 7.6±1.8 ?g CH3Cl m-2 h-1, 1.11±0.08g CHCl3 ?m-2 h-1, and 0.36±0.07 ?g C2Cl4 m-2 h-1. Extrapolated to a global scale, our emission estimates suggest a large potential source of 2 Tg CH3Cl yr-1 from tropical forests, which could account for the net budget discrepancy (underestimation of sources), as indicated previously. In addition, our estimates suggest a potential emission of 57±17 Gg C2C4 yr-1 from tropical forest soils, equal to half of the currently missing C2Cl4 sources. We hypothesize that the extensive deforestation over the last two decades relates to the observed global downward trend of atmospheric methyl chloride.

  13. A survey of household products for volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Sack, Thomas M.; Steele, David H.; Hammerstrom, Karen; Remmers, Janet

    A total of 1159 common household products were analysed for 31 volatile organic compounds as potential sources of indoor air pollution. The products were distributed among 65 product categories within 8 category classes: automotive products (14.4% of the products); household cleaners/polishes (9.6%); paint-related products (39.9%); fabric and leather treatments (7.9%); cleaners for electronic equipment (6.0%); oils, greases and lubricants (9.6%); adhesive-related products (6.6%); and miscellaneous products (6.1%). The study was conducted in two parts. In the first part, or the original study, the products were reanalysed for methylene chloride and five other chlorocarbons using purge-and-trap gas chromatography/mass spectrometry (GC/MS), and a data base containing the analytical results was developed. Because full mass spectra were taken, the original set of GC/MS data also contained information regarding other volatile chemicals in the products. However, this additional data was not reported at that time. In the second part of the study, the GC/MS data were reanalysed to determine the presence and concentrations of an additional 25 volatile chemicals. The 31 chemicals included in both parts of this study were: carbon tetrachloride; methylene chloride; tetrachloroethylene; 1,1,1-trichloroethane; trichlorethylene; 1,1,2-tricholorotrifluoroethane; acetone; benzene; 2-butanone; chlorobenzene; chloroform; cyclohexane; 1,2-dichloroethane; 1,4-dioxane; ethylbenzene; n-hexane; d-limonene; methylcyclohexane; methylcyclopentane; methyl isobutyl ketone; n-nonane; n-octane; ?-pinene; propylene oxide; styrene; 1,1,2,2-tetrachloroethane; tetrahydrofuran; toluene; m-mxylene; o-xylene; and p-xylene. Of the 31 chemicals, toluene, the xylenes and methylene chloride were found to occur most frequently—in over 40% of the products tested. Chemicals that were typically found in relatively high concentrations in the samples (i.e. greater than 20% w/w) included acetone, 2-butanone, hexane, methylene chloride, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, 1,1,2-trichlorotrifluoroethane and the xylenes. Chlorobenzene, d-limonene, 1,1,2,2-tetrachloroethane, n-nonane and styrene were not found in any of the products at or above the 0.1% level. In all, 935 of the products contained one or more of the target solvents at levels greater than 0.1%. The resulting data base contains information regarding the 1159 products, such as origin, cost, container type, lot number, etc., as well as quantitative information for each of the 31 chemicals. The frequency of occurrence and average concentrations for the target chemicals are summarized for each of the product classes.

  14. Use of fugacity model to analyze temperature-dependent removal of micro-contaminants in sewage treatment plants.

    PubMed

    Thompson, Kelly; Zhang, Jianying; Zhang, Chunlong

    2011-08-01

    Effluents from sewage treatment plants (STPs) are known to contain residual micro-contaminants including endocrine disrupting chemicals (EDCs) despite the utilization of various removal processes. Temperature alters the efficacy of removal processes; however, experimental measurements of EDC removal at various temperatures are limited. Extrapolation of EDC behavior over a wide temperature range is possible using available physicochemical property data followed by the correction of temperature dependency. A level II fugacity-based STP model was employed by inputting parameters obtained from the literature and estimated by the US EPA's Estimations Programs Interface (EPI) including EPI's BIOWIN for temperature-dependent biodegradation half-lives. EDC removals in a three-stage activated sludge system were modeled under various temperatures and hydraulic retention times (HRTs) for representative compounds of various properties. Sensitivity analysis indicates that temperature plays a significant role in the model outcomes. Increasing temperature considerably enhances the removal of ?-estradiol, ethinyestradiol, bisphenol, phenol, and tetrachloroethylene, but not testosterone with the highest biodegradation rate. The shortcomings of BIOWIN were mitigated by the correction of highly temperature-dependent biodegradation rates using the Arrhenius equation. The model predicts well the effects of operating temperature and HRTs on the removal via volatilization, adsorption, and biodegradation. The model also reveals that an impractically long HRT is needed to achieve a high EDC removal. The STP model along with temperature corrections is able to provide some useful insight into the different patterns of STP performance, and useful operational considerations relevant to EDC removal at winter low temperatures. PMID:21600629

  15. The structural and sorptive characteristics of high-surface-area carbonaceous material (HSACM) in soils.

    PubMed

    Huang, Hui-Chen; Lee, Jiunn-Fwu; Lee, Chung-Kung; Chen, Jiunn-Chen

    2006-12-01

    The structural and sorptive characteristics of the high-surface-area carbonaceous material (HSACM) isolated from soils were investigated. The HSACM contents in soils were first identified by the organic petrology method. A novel isolation method using acid demineralization, base extraction, and ZnBr(2) floatation sequential steps was developed to extract the HSACM from soil. The differences in structural and sorptive characteristics with the HSACM and the intact soil were investigated using nitrogen adsorption isotherms and trichloroethylene (TCE) sorption isotherms at low concentrations (0 to about 2 mg/L) both with and without tetrachloroethylene (PCE) as the cosolute. It was found that HSACM possesses a much higher specific surface area and pore volume as well as a smaller pore size than the original soil. Moreover, the sorption of TCE to HSACM is noticeably more nonlinear and competitive than to the original soil. A small amount of highly adsorptive HSACM is largely responsible for the nonlinear soil sorption of a single solute at very low concentrations. PMID:16839670

  16. Role of Vibrational Dynamics in Electronic Relaxation of Cr(acac)3.

    PubMed

    Maçôas, Ermelinda M S; Mustalahti, Satu; Myllyperkiö, Pasi; Kunttu, Henrik; Pettersson, Mika

    2015-03-19

    Ultrafast energy relaxation of Cr(acac)3 dissolved in tetrachloroethylene (TCE) is studied by time-resolved infrared (TRIR) spectroscopy by using electronic and vibrational excitation. After electronic excitation at 400 or 345 nm, the ground state recovers in two time scales: 15 ps (major pathway) and 800 ps (minor pathway), corresponding to fast electronic transition to the ground state and intermediate trapping on the long-lived (2)E state followed by intersystem crossing (ISC) to the ground state. The quantum yield for the fast recovery of the ground state depends on the excitation wavelength, being higher for 345 nm. Vibrational cooling (VC) occurs on the electronic excited states with a time constant of ?7 ps and on the ground electronic state with a time constant of ?12 ps. A kinetic model that explains the observed dynamics is presented. The key point of the model is that the ground-state recovery occurs via thermally activated back-intersystem-crossing (b-ISC) to the quartet manifold presumably via multiple curve crossings that are sampled while the system is vibrationally hot. This underlines the importance of vibrational cooling as a determining factor for the electronic relaxation chain. Vibrational excitation of the ?C?C and ?CO vibrations also revealed a subpicosecond (300-700 fs) intramolecular vibrational redistribution (IVR) process from the localized vibrational states to the bath of vibrational excitations. PMID:25590671

  17. Surface acoustic wave sensors/gas chromatography; and Low quality natural gas sulfur removal and recovery CNG Claus sulfur recovery process

    SciTech Connect

    Klint, B.W.; Dale, P.R.; Stephenson, C.

    1997-12-01

    This topical report consists of the two titled projects. Surface Acoustic Wave/Gas Chromatography (SAW/GC) provides a cost-effective system for collecting real-time field screening data for characterization of vapor streams contaminated with volatile organic compounds (VOCs). The Model 4100 can be used in a field screening mode to produce chromatograms in 10 seconds. This capability will allow a project manager to make immediate decisions and to avoid the long delays and high costs associated with analysis by off-site analytical laboratories. The Model 4100 is currently under evaluation by the California Environmental Protection Agency Technology Certification Program. Initial certification focuses upon the following organics: cis-dichloroethylene, chloroform, carbon tetrachloride, trichlorethylene, tetrachloroethylene, tetrachloroethane, benzene, ethylbenzene, toluene, and o-xylene. In the second study the CNG Claus process is being evaluated for conversion and recovery of elemental sulfur from hydrogen sulfide, especially found in low quality natural gas. This report describes the design, construction and operation of a pilot scale plant built to demonstrate the technical feasibility of the integrated CNG Claus process.

  18. The Wettability of a Multi-Component DNAPL on Quartz and Iron Oxide Sands

    NASA Astrophysics Data System (ADS)

    Molnar, I.; O'Carroll, D.; Gerhard, J.

    2009-05-01

    Dense nonaqueous phase liquids (DNAPLs) released to the subsurface often contain a variety of chemical constituents, via either co-disposal or intentional modification to increase their industrial efficacy. These additional constituents are often surface active compounds (surfactants)that partition to soil surfaces. The role that these surface active compounds that sorb to soil surfaces have on DNAPL migration is still poorly understood despite an increasing amount of work in the area. Most studies have focused on the role surface active chemicals play in altering the wettability of quartz sands. This research aims to extend the understanding of multi-component DNAPL transport to other porous media and under a variety of pH conditions. Specifically, the objective of this study was to compare the changes in the wettability of quartz and iron oxide sands in a tetrachloroethylene (PCE)/water system spiked with dodecylamine, a representative cationic surfactant. Wettability was assessed through: (i) contact angles measured on representative quartz and iron oxide-coated plates as well as (ii) contact angles measured directly on sands using an Axial Drop Symmetrical Analyzer apparatus; and (iii) capillary pressure-saturation relationships obtained via multi-step outflow experiments. In addition, two-dimensional sandbox experiments explored the influences of iron oxide and quartz sands on multicomponent DNAPL migration. Results suggest that quartz and iron oxide-coated sands exhibit different wetting characteristics under similar subsurface conditions.

  19. Spatial distribution characteristics of volatile halogenated hydrocarbons in unsaturated zone of Xiaodian sewage irrigation area, Taiyuan, China.

    PubMed

    Liao, Yuan; Ma, Teng; Cui, Yahui; Qi, Zhichong

    2014-12-01

    Sewage irrigation is one of the best options to reduce the stress on limited fresh water and to meet the nutrient requirement of crops. Environment pollution caused by volatile halogenated hydrocarbons (VHCs) associated with sewage irrigation has received increasing attention due to the toxicological importance in ecosystem. The aim of this study was to discuss the spatial distribution characteristics of VHCs in unsaturated zone under sewage irrigation and their migration in the environment. Soil samples were collected from XiaoDian district of TaiYuan city and measured for the major VHCs including of chloroform (CHCl3), tetrachloromethane (CCl4), trichloroethylene (C(2)HCl(3)), tetrachloroethylene(C(2)Cl(4)), pentachlorobenzene (C(6)HCl(5)), hexachlorobenzene (C(6)Cl(6)). Results showed that VHCs were accumulated in the unsaturated zone with long-term sewage irrigation. The contents of VHCs in the unsaturated zone of the study area were 34, 2, 3, 1.5, 8.3, 4.8 times higher than the background value respectively. Soils with long-term irrigation of sewage showed higher contents of VHCs than that with short-term irrigation of sewage. Not only the irrigation time, soil physical properties (e.g. soil texture) also played an important role on VHCs accumulation in soil. PMID:25193606

  20. Plume and lithologic profiling with surface resistivity and seismic tomography.

    PubMed

    Watson, David B; Doll, William E; Gamey, T Jeffrey; Sheehan, Jacob R; Jardine, Philip M

    2005-01-01

    Improved surface-based geophysical technologies that are commercially available provide a new level of detail that can be used to guide ground water remediation. Surface-based multielectrode resistivity methods and tomographic seismic refraction techniques were used to image to a depth of approximately 30 m below the surface at the Natural and Accelerated Bioremediation Research Field Research Center. The U.S. Department of Energy (DOE) established the research center on the DOE Oak Ridge Reservation in Oak Ridge, Tennessee, to conduct in situ field-scale studies on bioremediation of metals and radionuclides. Bioremediation studies are being conducted on the saprolite, shale bedrock, and ground water at the site that have been contaminated with nitrate, uranium, technetium, tetrachloroethylene, and other contaminants (U.S. DOE 1997). Geophysical methods were effective in imaging the high-ionic strength plume and in defining the transition zone between saprolite and bedrock zones that appears to have a significant influence on contaminant transport. The geophysical data were used to help select the location and depth of investigation for field research plots. Drilling, borehole geophysics, and ground water sampling were used to verify the surface geophysical studies. PMID:15819938

  1. H-Area Seepage Basins: Groundwater quality assessment report, Savannah River Site

    SciTech Connect

    Not Available

    1990-09-01

    During the second quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, nonvolatile beta, mercury, lead, cadmium, trichloroethylene chromium, and arsenic in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the H-Area Seepage Basins. Elevated levels of tritium above the PDWS were exhibited in seventy-seven of the 105 (73%) groundwater monitoring wells. Elevated levels of nitrate in excess of the PDWS were exhibited in forty-four of the 105 (42%) monitoring wells.

  2. H-Area Seepage Basins: Groundwater quality assessment report, Savannah River Site. Second quarter, 1990

    SciTech Connect

    Not Available

    1990-09-01

    During the second quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, nonvolatile beta, mercury, lead, cadmium, trichloroethylene chromium, and arsenic in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the H-Area Seepage Basins. Elevated levels of tritium above the PDWS were exhibited in seventy-seven of the 105 (73%) groundwater monitoring wells. Elevated levels of nitrate in excess of the PDWS were exhibited in forty-four of the 105 (42%) monitoring wells.

  3. Separation of volatile organic compounds from dry and humidified nitrogen using polyurethane membranes

    SciTech Connect

    Ponangi, R.P.; Pintauro, P.N. [Tulane Univ., New Orleans, LA (United States). Dept. of Chemical Engineering] [Tulane Univ., New Orleans, LA (United States). Dept. of Chemical Engineering

    1996-08-01

    Homogeneous polyurethane membranes, containing ether or ester soft segments, were examined for the vapor-phase separation of tetrachloroethylene, carbon tetrachloride, benzene, toluene, p-xylene, hexane, and benzene/toluene/xylene mixtures from nitrogen. Both equilibrium sorption/desorption and organic/N{sub 2} separation experiments were carried out. The membranes performed best with aromatic and chlorine-containing organic compounds, with organic/dry N{sub 2} selectivities ranging from 30 to 210 and pressure-normalized permeabilities as high as 1.25 {times} 10{sup {minus}3} cm{sup 3} (STP)/(cm{sup 2} s cmHg) for saturated organic feeds at 23 C and a downstream pressure of 0.005--0.01 atm. Organic/N{sub 2} selectivities and organic permeabilities were generally higher than those reported in the literature for poly(dimethylsiloxane) and aromatic polyimide membranes. Organic permeabilities in the ether soft segment polyurethane membranes were greater than those measured in the polyester films, due to higher organic solubility coefficients (more polymer swelling). The greater swelling of the polyether membranes increased the nitrogen permeabilities and lowered the organic/N{sub 2} selectivities relative to those for polyester membranes. Water permeabilities in both types of polyurethane membranes were low and independent of the organic feed component. The presence of water vapor in the feed (up to 1.2 vol %) had no effect on transmembrane organic fluxes.

  4. Spatiotemporal changes of CVOC concentrations in karst aquifers: Analysis of three decades of data from Puerto Rico.

    PubMed

    Yu, Xue; Ghasemizadeh, Reza; Padilla, Ingrid; Irizarry, Celys; Kaeli, David; Alshawabkeh, Akram

    2015-04-01

    We studied the spatial and temporal distribution patterns of Chlorinated Volatile Organic Compounds (CVOCs) in the karst aquifers in northern Puerto Rico (1982-2013). Seventeen CVOCs were widely detected across the study area, with the most detected and persistent contaminated CVOCs including trichloroethylene (TCE), tetrachloroethylene (PCE), carbon tetrachloride (CT), chloroform (TCM), and methylene chloride (DCM). Historically, 471 (76%) and 319 (52%) of the 615 sampling sites have CVOC concentrations above the detection limit and maximum contamination level (MCL), respectively. The spatiotemporal patterns of the CVOC concentrations showed two clusters of contaminated areas, one near the Superfund site "Upjohn" and another near "Vega Alta Public Supply Wells." Despite a decreasing trend in concentrations, there is a general northward movement and spreading of contaminants even beyond the extent of known sources of the Superfund and landfill sites. Our analyses suggest that, besides the source conditions, karst characteristics (high heterogeneity, complex hydraulic and biochemical environment) are linked to the long-term spatiotemporal patterns of CVOCs in groundwater. PMID:25522355

  5. Geochemistry of volatile organic compounds in seawater: Mesocosm experiments with 14C-model compounds

    NASA Astrophysics Data System (ADS)

    Wakeham, Stuart G.; Canuel, Elizabeth A.; Doering, Peter H.

    1986-06-01

    A series of ten radiotracer experiments were conducted in controlled experimental ecosystems (mesocosms) to investigate the behavior of volatile organic compounds (VOC) in seawater. Time-series measurements of the redistribution of 14C-activity within several major pools - dissolved, particulate, intermediate metabolite, and CO 2 - in the ecosystem made possible an evaluation of the rates of processes - volatilization, biodegradation, Sorption and sedimentation - acting to remove VOC from seawater in summer. The behavior of the model 14C-VOC fell into three categories. Aromatic hydrocarbons (benzene, toluene, naphthalene) were subject to both volatilization and biodegradation, with mineralization dominating in summer. Chlorinated C 2-hydrocarbons (tetrachloroethylene) and chlorinated benzenes (chlorobenzene, 1,4-dichlorobenzene, and 1,2,4-trichlorobenzene) were affected only by volatilization and were relatively resistant to biodegradation. Of all the model VOC studied, only aliphatic hydrocarbons (decane and octadecane) were sorbed onto suspended paniculate matter; however, the primary route of loss from the water column appeared to be biodegradation rather than sedimentation. The mesocosm-derived removal rate constants were then applied to estimate summer VOC residence times in Narragansett Bay, Rhode Island of about 1 day for aromatic hydrocarbons, 1 week for the chlorinated VOC and about 1 day for aliphatic hydrocarbons. Residence times in winter might be on the order of 1 week for all VOC.

  6. A pilot study for delineation of areas contributing water to wellfields at Jackson, Tennessee

    USGS Publications Warehouse

    Broshears, R.E.; Connell, J.F.; Short, N.C.

    1991-01-01

    The U.S. Geological Survey, in cooperation with the Tennessee Department of Health and Environment, Division of Groundwater Protection, and the Jackson Utility Division, conducted a pilot study to determine data needs and the applicability of four methods for the delineation of wellhead protection areas. Jackson Utility Division in Jackson, Madison County, Tennessee, pumps about 9 million gallons of ground water daily from two municipal wellfields that tap an unconfined sand aquifer. Under natural hydraulic gradients, ground waterflows southward toward the South Wellfield at approximately 2 to 3 feet per day; natural flow toward the North Wellfield from the east at 1 to 2 feet per day. Water quality generally is suitable for most uses. Concentrations of dissolved solids are low, and excessive iron is the only significant naturally occurring water-quality problem. However, trace concentrations of volatile organic compounds have been detected in water pumps from the South Wellfield; the highest concentration of a single compound has been 23 micrograms per liter of tetrachloroethylene. Potential sources of ground-water contamination in the Jackson area include a hazardous-waste site, municipal and industrial landfill, and underground-storage tanks. Some of the four method for delineating wellhead protection areas did not adequately describe zones contributing flow to the wellfields. Calculations based on a uniform flow equation provided a preliminary delineation of zones of contribution for the wellfields and ground-water time-of-travel contours. Limitations of the applied methods motivated the design of a more rigorous hydrogeologic investigation.

  7. Numerical simulation of DNAPL source zone remediation with in situ chemical oxidation (ISCO)

    NASA Astrophysics Data System (ADS)

    West, Michael R.; Kueper, Bernard H.

    2012-08-01

    Numerical simulations were conducted to evaluate the efficacy of in situ field scale chemical oxidation (ISCO) (with permanganate) for trichloroethylene (TCE) and tetrachloroethylene (PCE) DNAPL in eight idealized heterogeneous porous media sites. The goal of this work was to study the effects of DNAPL source zone remediation at the site scale utilizing a high-resolution three-dimensional numerical model. The model results demonstrated that both dissolution (no treatment) and treatment were unable to completely deplete DNAPL mass or boundary mass flux for any of the sites over a 10 year period. Performance was highly variable due to competition with oxidizable organic aquifer materials, manganese dioxide (rind) formation, DNAPL architecture, and geologic characteristics. When compared to dissolution only, DNAPL mass depletion at the end of treatment ranged from adverse impacts to a three-fold improvement, but diminished with post-treatment monitoring. Similarly, the relative reduction in boundary mass flux varied between unity and a factor of two at the termination of treatment, but at 10 years ranged from a 10-fold reduction to adverse impacts. During the post-treatment phase of the simulations, most of the benefits achieved during active treatment were negated due to dissolution tailing.

  8. Concentration rebound following in situ chemical oxidation in fractured clay.

    PubMed

    Mundle, Keely; Reynolds, David A; West, Michael R; Kueper, Bernard H

    2007-01-01

    A two-dimensional, transient-flow, and transport numerical model was developed to simulate in situ chemical oxidation (ISCO) of trichloroethylene and tetrachloroethylene by potassium permanganate in fractured clay. This computer model incorporates dense, nonaqueous phase liquid dissolution, reactive aquifer material, multispecies matrix diffusion, and kinetic formulations for the oxidation reactions. A sensitivity analysis for two types of parameters, hydrogeological and engineering, including matrix porosity, matrix organic carbon, fracture aperture, potassium permanganate dosage, and hydraulic gradient, was conducted. Remediation metrics investigated were the relative rebound concentrations arising from back diffusion and percent mass destroyed. No well-defined correlation was found between the magnitude of rebound concentrations during postremedy monitoring and the amount of contaminant mass destroyed during the application. Results indicate that all investigated parameters affect ISCO remediation in some form. Results indicate that when advective transport through the fracture is dominant relative to diffusive transport into the clay matrix (large System Peclet Number), permanganate is more likely to be flushed out of the system and treatment is not optimal. If the System Peclet Number is too small, indicating that diffusion into the matrix is dominant relative to advection through the fracture, permanganate does not traverse the entire fracture, leading to postremediation concentration rebound. Optimal application of ISCO requires balancing advective transport through the fracture with diffusive transport into the clay matrix. PMID:17973747

  9. Evaluation of geophysical methods for the detection of subsurfacetetracgloroethyene in controlled spill experiments

    SciTech Connect

    Mazzella, Aldo; Majer, Ernest L.

    2006-04-10

    A controlled Tetrachloroethylene (PCE) spill experiment was conducted in a multi-layer formation consisting of sand and clayey-sandlayers. The purpose of the work was to determine the detection limits and capability of various geophysical methods. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This experiment provided a clear identification of any geophysical anomalies associated with the presence of the PCE. During the injection period all the techniques indicated anomalies associated with the PCE. In order to quantify the results and provide an indication of the PCE detection limits of the various geophysical methods, the tank was subsequently excavated and samples of the various layers were analyzed for residual PCE concentration with gas chromatography (GC). This paper presents some of the results of five of the techniques: cross borehole complex resistivity (CR) also referred to as spectral induced polarization (SIP), cross borehole high resolution seismic (HRS), borehole self potential (SP), surface ground penetration radar (GPR), and borehole video (BV).

  10. Malignant Tumors of the Female Reproductive System

    PubMed Central

    Labrèche, France

    2012-01-01

    This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers. PMID:23019529

  11. Uptake and fate of organohalogens from contaminated groundwater in woody plants

    SciTech Connect

    Sytsma, L.; Mulder, J.; Schneider, J. [Argonne National Lab., IL (United States)] [and others

    1997-12-31

    The emerging technology of phytoremediation uses green plants for low-cost, low-tech remediation processes in which selected plants and natural or engineered microorganisms work together to metabolize, convert, absorb, accumulate, sequester, or otherwise render harmless multiple environmental contaminants. For many organic contaminants, such as tricholoroethylene (TCE) and tetrachloroethylene (PCE), there is evidence that plants can degrade a portion of the organohalogen that is taken up to form less volatile compounds, such as trichloroacetic acid (TCAA), which are sequestered in the plant tissue while the remainder is passed out of the leaf tissue with the transpiration stream. Analysis of leaves from trees in uncontaminated areas gives TCAA concentrations that are typically under 100 ng/g TCAA, while in contaminated areas concentrations run as high as 1,000 ng/g. Hybrid poplar plants fed by TCE- and PCE-spiked nutrient solutions in a greenhouse showed elevated TCAA levels in the leaves within a week, as well as evidence for evapotranspiration of the TCE and PCE.

  12. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA.

    PubMed

    Harte, Philip T; Smith, Thor E; Williams, John H; Degnan, James R

    2012-05-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment. PMID:22459605

  13. F-Area seepage basins, groundwater quality assessment report, first quarter 1990

    SciTech Connect

    Not Available

    1990-06-01

    During the first quarter of 1990, wells which make up the F-Area Seepage Basins (F-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, gross alpha, and nonvolatile beta. The primary contaminants observed at wells monitoring the F-Area Seepage Basins are tritium, nitrate, cadmium, lead, total radium, gross alpha, and nonvolatile beta. Concentrations of at least one of the following constituents: tritium, nitrate, total radium, gross alpha, cadmium, lead, tetrachloroethylene, nonvolatile beta, endrin, lindane, barium, fluoride, mercury, and trichlorethylene in excess of the primary drinking water standard (PDWS) were observed in at least one well monitoring the F-Area Seepage Basins. Tritium concentrations above the PDWS occur in forty-four of the fifty-nine (75%) groundwater monitoring wells. Nitrate concentrations above the PDWS occur in thirty-four of the fifty-nine (59%) groundwater wells. The radionuclides, total radium, gross alpha, and nonvolatile beta, exceed the PDWS is over twenty-five percent of the groundwater wells. Heavy metals, cadmium and lead in particular, exceed the PDWS in over twelve percent of the wells. Since 1987, tritium and nitrate concentrations have been steadily declining in a majority of the wells. However, tritium concentrations, from fourth quarter 1989 to first quarter 1990, have increased.

  14. Chlorinated organic compounds in ground water at Roosevelt Field, Nassau County, Long Island, New York

    USGS Publications Warehouse

    Eckhardt, D.A.; Pearsall, K.A.

    1989-01-01

    Trichloroethylene (TCE), 1,2-dichloroethylene (DCE), and tetrachloroethylene (PCE) have been detected in water from five public-supply wells and six cooling-water wells that tap the Magothy aquifer at Roosevelt Field, a 200-acre area that is now a large shopping mall and office-building complex. The cooling water is discharged after use to the water table (upper glacial) aquifer through a nearby recharge basin and a subsurface drain field. Three plumes of TCE in groundwater have been delineated--the source plume, which has penetrated both aquifers , and two more recent plumes emanating from the two discharge sites in the water-table aquifer. Concentrations of inorganic constituents in the three plumes are the same as those in ambient water in the area. The two secondary plumes discharged cooling water extended at least 1,000 ft south-southeastward in the direction of regional groundwater flow. Pumping at wells screened in the middle and basal sections of the Magothy aquifers, where clay layers are absent and sandy zones provide good vertical hydraulic connection within the aquifer system, has increased the rate of downward contaminant advection. The transient increases in downward movement are cumulative over time and have brought TCE to the bottom of the Magothy aquifer, 500 ft below land surface. (USGS)

  15. A paired comparison between human skin and hairless guinea pig skin in vitro permeability and lag time measurements for 6 industrial chemicals.

    PubMed

    Frasch, H Frederick; Barbero, Ana M

    2009-01-01

    The purpose of the present study was to measure and compare permeability coefficients (k(p)) and lag times (tau) in human skin and hairless guinea pig (HGP) skin. Paired experiments employed heat-separated epidermal membranes from human and HGP sources mounted on static in vitro diffusion cells. Infinite-dose, saturated aqueous solutions of 6 industrial chemicals were used as donors: aniline, benzene, 1,2- dichloroethane, diethyl phthalate, naphthalene, and tetrachloroethylene. No significant differences were found between human and HGP skin for either k(p) or tau for any of these chemicals (p >or= .24). HGP vs. human k(p) measurements, and HGP vs. human tau measurements, were highly correlated. For k(p), the slope of the linear correlation was close to unity (1.080 +/- 0.182) and the intercept close to 0 (0.015 +/- 0. 029 cm/h), with a correlation coefficient (r(2)) = 0.898. For tau, the slope was also close to unity (0.818 +/- 0.030) and the intercept close to 0 (-0.014 +/- 0.023 h), with r(2) = 0.994. These results suggest that HGP skin may serve as an excellent surrogate for human skin in in vitro dermal penetration studies. PMID:19552540

  16. Adapting the Brueel and Kjaer Multi-gas Monitor Type 1302 to measure selected volatile organic compounds (VOCs) in soil

    SciTech Connect

    Palausky, M.A.; Waters, L.C.; Counts, R.W.; Jenkins, R.A. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    The Brueel and Kjaer Multi-gas Monitor Type 1302 can simultaneously measure up to five different volatile organic compounds (VOCS) in a single air sample by using optical filters combined with a photo acoustic detector. The monitor has previously been validated to measure VOCs in water, by purging aqueous samples with air into Tedlar bags. The method used to measure VOCs in water has been adapted for use with soil. Soil samples are diluted with water and VOCs are purged with air from the resulting slurry into a Tedlar bag. The contents of the bag are then analyzed with the Multi-gas monitor. Data have been generated for the measurement of chloroform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, and acetone. The method is linear for these VOCs from approximately 1 to at least 128 {micro}g/g of soil (ppm). There is no measurable cross interference of these VOCs when more than one of the compounds is spiked into a single soil sample. Contaminants other than those being measured may interfere with detection of these VOCS, so some prior site characterization is required. The method is easy to perform, rapid, reproducible, and sensitive enough for field screening applications.

  17. Adapting the Bruel and Kjaer Multi-gas Monitor Type 1302 to measure selected volatile organic chemicals (VOCs) in soil

    SciTech Connect

    Palausky, M.A.; Waters, L.C.; Counts, R.W.; Jenkins, R.A.

    1995-04-01

    The Bruel and Kjaer Multi-gas Monitor Type 1302 can simultaneously measure up to five different volatile organic chemicals (VOCS) in a single air sample by using optical filters combined with a photo acoustic detection method. The monitor has previously been validated to measure VOCs in water, by purging aqueous samples into Tedlar{trademark} bags. The method used to measure VOCs in water has been adapted for use with soil. Soil samples are diluted with water and VOCs are purged with air from the resulting slurry into a Tedlar{trademark} bag. The contents of the Tedlar{trademark} bag are then analyzed with the multi-gas monitor. Data have been generated for the measurement of chloroform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, and acetone. The method is linear for these VOCs from approximately 1 to at least 128 {mu}g/g of soil (ppM). There is no measurable cross interference of these VOCs with each other when more than one is present in a single soil sample. Contaminants other than those being measured may interfere with detection of these VOCS, so some prior site characterization is required. The method is easy to perform, rapid, reproducible, and sensitive enough for field screening applications.

  18. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.

    1993-03-01

    During fourth quarter 1992, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded final Primary Drinking Water Standards (PDWS) and the Savannah River Site Flag 2 criteria during the quarter. The results for fourth quarter 1992 are fairly consistent with the rest of the year's data. Tetrachloroethylene exceeded the final PDWS in well AMB 4D only two of the four quarters; in the other three wells in which it was elevated, it was present at similar levels throughout the year. Trichloroethylene consistently exceeded its PDWS in wells AMB 4A, 4B, 4D, 5, and 7A during the year. Trichloroethylene was elevated in well AMB 6 only during third and fourth quarters and in well AMB 7 only during fourth quarter. Total alpha-emitting radium was above the final PDWS for total radium in well AMB 5 at similar levels throughout the year and exceeded the PDWS during one of the three quarters it was analyzed for (third quarter 1992) in well AMB 10B.

  19. Sanitary Landfill 1991 annual groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.; Norrell, G.T.; Bennett, C.B.

    1992-02-01

    The Savannah River Site (SRS) Sanitary Landfill is an approximately seventy acre site located just south of SRS Road C between the Savannah River Site`s B-Area and Upper Three Runs Creek. Results from the first through third quarter 1991 groundwater monitoring date continue to show evidence of elevated levels of several hazardous constituents beneath the Sanitary Landfill: tritium, vinyl chloride, total radium, cadmium, 1,1,1-trichloroethane, 1,2 dichloroethane, 1,4 dichlorobenzene, trichloroethylene (TCE), tetrachloroethylene, and 1,1 dichloroethylene in excess of the primary drinking water standards were observed in at least one well monitoring the Sanitary Landfill during the third quarter of 1991. All of these constituents, except radium, were observed in the lower half of the original thirty-two acre site or the southern expansion site. Trichloroethylene and vinyl chloride are the primary organic contaminants in groundwater beneath the Sanitary Landfill. Vinyl chloride has become the primary contaminant during 1991. Elevated levels of benzene were consistently detected in LFW 7 in the past, but were not present in any LFW wells during the third quarter of 1991. A minor tritium plume is present in the central part of original thirty-two acre landfill. Elevated levels of tritium above the PDWS were consistently present in LFW 10A through 1991. This well has exhibited elevated tritium activities since the second quarter of 1989. Contaminant concentrations in the Sanitary Landfill are presented and discussed in this report.

  20. Sanitary Landfill 1991 annual groundwater monitoring report

    SciTech Connect

    Thompson, C.Y.; Norrell, G.T.; Bennett, C.B.

    1992-02-01

    The Savannah River Site (SRS) Sanitary Landfill is an approximately seventy acre site located just south of SRS Road C between the Savannah River Site's B-Area and Upper Three Runs Creek. Results from the first through third quarter 1991 groundwater monitoring date continue to show evidence of elevated levels of several hazardous constituents beneath the Sanitary Landfill: tritium, vinyl chloride, total radium, cadmium, 1,1,1-trichloroethane, 1,2 dichloroethane, 1,4 dichlorobenzene, trichloroethylene (TCE), tetrachloroethylene, and 1,1 dichloroethylene in excess of the primary drinking water standards were observed in at least one well monitoring the Sanitary Landfill during the third quarter of 1991. All of these constituents, except radium, were observed in the lower half of the original thirty-two acre site or the southern expansion site. Trichloroethylene and vinyl chloride are the primary organic contaminants in groundwater beneath the Sanitary Landfill. Vinyl chloride has become the primary contaminant during 1991. Elevated levels of benzene were consistently detected in LFW 7 in the past, but were not present in any LFW wells during the third quarter of 1991. A minor tritium plume is present in the central part of original thirty-two acre landfill. Elevated levels of tritium above the PDWS were consistently present in LFW 10A through 1991. This well has exhibited elevated tritium activities since the second quarter of 1989. Contaminant concentrations in the Sanitary Landfill are presented and discussed in this report.

  1. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Fourth quarter 1992 and 1992 summary

    SciTech Connect

    Thompson, C.Y.

    1993-03-01

    During fourth quarter 1992, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded final Primary Drinking Water Standards (PDWS) and the Savannah River Site Flag 2 criteria during the quarter. The results for fourth quarter 1992 are fairly consistent with the rest of the year`s data. Tetrachloroethylene exceeded the final PDWS in well AMB 4D only two of the four quarters; in the other three wells in which it was elevated, it was present at similar levels throughout the year. Trichloroethylene consistently exceeded its PDWS in wells AMB 4A, 4B, 4D, 5, and 7A during the year. Trichloroethylene was elevated in well AMB 6 only during third and fourth quarters and in well AMB 7 only during fourth quarter. Total alpha-emitting radium was above the final PDWS for total radium in well AMB 5 at similar levels throughout the year and exceeded the PDWS during one of the three quarters it was analyzed for (third quarter 1992) in well AMB 10B.

  2. DESORPTION BEHAVIOR OF TRICHLOROETHENE AND TETRACHLOROETHENE IN U.S. DEPARTMENT OF ENERGY SAVANNAH RIVER SITE UNCONFINED AQUIFER SEDIMENTS

    SciTech Connect

    Vangelas, K; Robert G. Riley, R; James E. Szecsody, J; A. V. Mitroshkov, A; C. F. Brown, C; Brian02 Looney, B

    2007-01-10

    Sorption is governed by the physico-chemical processes that partition solutes between the aqueous and solid phases in aquifers. For environmental systems, a linear equilibrium relationship between the amount of contaminant in the alternative phases is often assumed. In this traditional approach, the distribution coefficient, or K{sub d}, is a ratio of contaminant associated with the solid phase to the contaminant in the water phase. Recent scientific literature has documented time-dependant behaviors in which more contaminant mass is held in the solid phase than predicted by the standard model. Depending on the specific conceptualization, this has been referred to as nonlinear sorption, time-variable sorption, or ''irreversible sorption''. The potential impact of time-variable sorption may be beneficial or detrimental depending on the specific conditions and remediation goals. Researchers at the Pacific Northwest National Laboratory (PNNL) have been studying this process to evaluate how various soil types will affect this process for sites contaminated with chlorinated solvents. The results described in this report evaluate sorption-desorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) in Savannah River Site (SRS) soils. The results of this study will be combined with ongoing PNNL research to provide a more comprehensive look at this process and its impact on contaminant plume stability and sustainability. Importantly, while the results of the study documented differences in sorption properties between two tested SRS soils, the data indicated that ''irreversible sorption'' is not influencing the sorption-desorption behaviors of TCE and PCE for these soils.

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

    PubMed

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

    2015-05-01

    Changes in composition of phytoplankton assemblages due to short-chained chlorinated hydrocarbons (tetrachloroethane, tetrachloroethylene and trichloroethylene) were studied in microcosm experiments with different initial diversities. Diversity decreased further during treatments in the less diverse 2011 summer assemblages, dominated by the euglenid Trachelomonas volvocinopsis (its relative abundance was nearly 70 %). Diversity did not change significantly during treatments in the more diverse 2012 summer assemblages, dominated by cryptomonads (their relative abundance was 40 %). The dominant Trachelomonas volvocinopsis in 2011, due to its insensitivity to the treatment and presumably high competition skills, filled released habitats occurring when sensitive species were not detectable any more. In contrast, cryptomonads were extremely sensitive to the treatments, their abundance decreased under detection limit in the treated assemblages, regardless of diversity conditions. Our results showed that population dynamics of dominant species determine the response to the contamination of the entire community, if these species display high resistance or resilience. If the dominant species was highly sensitive and recovered slowly, compensatory growth of rare species maintained high levels of ecosystem performance. PMID:25680969

  4. The Site of Oxygen Limitation in Soybean Nodules1

    PubMed Central

    Kuzma, Monika M.; Winter, Heike; Storer, Paul; Oresnik, Ivan; Atkins, Craig A.; Layzell, David B.

    1999-01-01

    In legume nodules the [O2] in the infected cells limits respiration and nitrogenase activity, becoming more severe if nodules are exposed to subambient O2 levels. To identify the site of O2 limitation, adenylate pools were measured in soybean (Glycine max) nodules that were frozen in liquid N2 before being ground, lyophilized, sonicated, and separated on density gradients of nonaqueous solvents (heptane/tetrachloroethylene) to yield fractions enriched in bacteroid or plant components. In nodules maintained in air, the adenylate energy charge (AEC = [ATP + 0.5 ADP]/[ATP + ADP + AMP]) was lower in the plant compartment (0.65 ± 0.04) than in the bacteroids (0.76 ± 0.095), but did not change when the nodulated root system was exposed to 10% O2. In contrast, 10% O2 decreased the bacteroid AEC to 0.56 ± 0.06, leading to the conclusion that they are the primary site of O2 limitation in nodules. To account for the low but unchanged AEC in the plant compartment and for the evidence that mitochondria are localized in O2-enriched microenvironments adjacent to intercellular spaces, we propose that steep adenylate gradients may exist between the site of ATP synthesis (and ADP use) in the mitochondria and the extra-mitochondrial sites of ATP use (and ADP production) throughout the large, infected cells. PMID:9952434

  5. Chemical oxidation of volatile and semi-volatile organic compounds in soil

    SciTech Connect

    Gates, D.D.; Siegrist, R.L.; Cline, S.R.

    1995-06-01

    Subsurface contamination with fuel hydrocarbons or chlorinated hydrocarbons is prevalent throughout the Department of Energy (DOE) complex and in many sites managed by the Environmental Protection Agency (EPA) Superfund program. The most commonly reported chlorinated hydrocarbons (occurring > 50% of DOE contaminated sites) were trichloroethylene (TCE), 1, 1, 1,-trichloroethane (TCA), and tetrachloroethylene (PCE) with concentrations in the range of 0.2 {mu}g/kg to 12,000 mg/kg. The fuel hydrocarbons most frequently reported as being present at DOE sites include aromatic compounds and polyaromatic compounds such as phenanthrene, pyrene, and naphthalene. The primary sources of these semi-volatile organic compounds (SVOCs) are coal waste from coal fired electric power plants used at many of these facilities in the past and gasoline spills and leaks. Dense non-aqueous phase liquids (DNAPLs) can migrate within the subsurface for long periods of time along a variety of pathways including fractures, macropores, and micropores. Diffusion of contaminants in the non-aqueous, aqueous, and vapor phase can occur from the fractures and macropores into the matrix of fine-textured media. As a result of these contamination processes, removal of contaminants from the subsurface and the delivery of treatment agents into and throughout contaminated regions are often hindered, making rapid and extensive remediation difficult.

  6. Seed germination and root elongation as indicators of exposure of wetland seedlings to metals

    SciTech Connect

    Sutton, H.D.; Stokes, S.L.; Hook, D.D.; Klaine, S.J. [Clemson Univ., Pendleton, SC (United States)

    1995-12-31

    Wetland ecosystems have often been impacted by the addition of hazardous waste materials. Methods are needed to evaluate the effect of these substances on wetland ecosystems and the organisms within them. This study evaluates the response of various wetland plant species to representative contaminants (cadmium, nickel, atrazine, anthracene, and tetrachloroethylene). Species tested include Caphalanthus occidentalis (buttonbush), Saururus cernuus (lizard`s tail), Liquidambar styraciflua (sweetgum), Sparganium americanum (bur-reed), and Fraxinus pennsylvanica (green ash). To the authors` knowledge these species have rarely if ever been used in toxicological assays. The endpoints used are germination and root elongation. Preliminary studies using a petri dish system have shown decreased germination at the highest metal concentration (50mg/L) and decreased root elongation in the higher metal concentrations (10, 25, and 50mg/L). Interference from the carrier was observed in the organic tests. Root elongation studies using the metals are being continued using tubes with various sand and vermiculite mixes into which freshly germinated seeds are placed. Species with the best responses will be tested in the field at the Savannah River Site, SC, and also with fuel oil. Lettuce (Lactuca saliva) and radish (Raphanus sativus) are being tested alongside the wetland species as reference organisms for which tests are well established.

  7. Chlorination byproducts induce gender specific autistic-like behaviors in CD-1 mice.

    PubMed

    Guariglia, Sara Rose; Jenkins, Edmund C; Chadman, Kathryn K; Wen, Guang Y

    2011-10-01

    In 2000, the Agency for Toxic Substances and Disease Registry (ATSDR) released a report concerning elevated autism prevalence and the presence water chlorination byproducts in the municipal drinking water supply in Brick Township, New Jersey. The ATSDR concluded that it was unlikely that these chemicals, specifically chloroform, bromoform (Trihalomethanes; THMs) and tetrachloroethylene (Perchloroethylene; PCE) had contributed to the prevalence of autism in this community based upon correlations between timing of exposure and/or concentration of exposure. The ATSDR conclusion may have been premature, as there is no conclusive data evidencing a correlation between a particular developmental time point that would render an individual most susceptible to toxicological insult with the development of autism. Therefore, it was our aim to determine if these chemicals could contribute to autistic like behaviors. We found that males treated with THMs and PCE have a significant reduction in the number of ultrasonic vocalizations (USVs) emitted in response to maternal separation, which are not attributed to deficits in vocal ability to or to lesser maternal care. These same males also show significantly elevated anxiety, an increase in perseverance behavior and a significant reduction in sociability. The sum of our data suggests that male, but not female mice, develop autistic like behaviors after gestational and postnatal exposure to the aforementioned chemical triad via drinking water. We believe development of such aberrant behaviors likely involves GABAergic system development. PMID:21740927

  8. Optimization of a novel procedure for determination of VOCs in water and human urine samples based on SBSE coupled with TD-GC-HRMS.

    PubMed

    Jakubowska, Natalia; Henkelmann, Bernhard; Schramm, Karl-Werner; Namiesnik, Jacek

    2009-09-01

    In this study, stir-bar sorptive extraction and thermal desorption followed by gas chromatography coupled with high resolution mass spectrometry was applied for determination of halo-organic compounds (bromodichloromethane, dibromochloromethane, bromoform, and tetrachloroethylene) in water and human urine samples. Time of extraction and stirring speed were optimized. The results show that the optimum extraction time is 30 min with 600 rpm of stirring speed with Twister of 20 mm in length and 1.0-mm film thickness of PDMS (126 microL). The calibration curves, limits of detection and quantification for all compounds were calculated. This procedure is characterized by very low limits of detection and quantitation: lower than 0.0017 microg/L and good repeatability for all four volatile compounds. This new analytical procedure was identified to be easy, reliable, sensitive, and requires only small amounts of sample. It can constitute a good alternative to well-known procedures based on application of head space and gas chromatography coupled with electron capture detection. PMID:19772746

  9. L-Area Reactor - 1993 annual - groundwater monitoring report

    SciTech Connect

    Chase, J.A.

    1994-09-01

    Groundwater was sampled and analyzed during 1993 from wells monitoring the water table at the following locations in L Area: the L-Area Acid/Caustic Basin (four LAC wells), L-Area Research Wells in the southern portion of the area (outside the fence; three LAW wells), the L-Area Oil and Chemical Basin (four LCO wells), the L-Area Disassembly Basin (two LDB wells), the L-Area Burning/Rubble Pit (four LRP wells), and the L-Area Seepage Basin (four LSB wells). During 1993, tetrachloroethylene was detected above its drinking water standard (DWS) in the LAC, LAW, LCO, and LDB well series. Lead exceeded its 50 {mu}g/L standard in the LAW, LDB, and LRP series, and tritium was above its DWS in the LAW, LCO, and LSB series. Apparently anomalous elevated levels of the common laboratory contaminant bis(2-ethylhexyl)phthalate were reported during first quarter in one well each in the LAC series and LCO series, and during third quarter in a different LCO well. Extensive radionuclide analyses were performed during 1993 in the LAC, LAW, and LCO well series. No radionuclides other than tritium were reported above DWS or Flag 2 criteria.

  10. Ranking the potential carcinogenic hazards to workers from exposures to chemicals that are tumorigenic in rodents.

    PubMed Central

    Gold, L S; Backman, G M; Hooper, N K; Peto, R

    1987-01-01

    For 41 chemicals there exist both reasonable data on carcinogenic potency in experimental animals and also a defined Permissible Exposure Level (PEL), which is the upper limit of legally permissible chronic occupational exposure for U.S. workers. These 41 agents are ranked by an index that compares the permitted chronic human exposure to the chronic dose rate that induces tumors in 50% of laboratory animals. This index, the Permitted Exposure/Rodent Potency index, or PERP, does not estimate absolute risks directly, but rather suggests the relative hazards that such substances may pose. The PERP values for these 41 substances differ by more than 100,000-fold from each other. The PERP does not take into account the actual level of exposure or the number of exposed workers. Nevertheless, it might be reasonable to give priority attention to the reduction of allowable worker exposures to substances that appear most hazardous by this index and that some workers may be exposed to full-time near the PEL. Ranked by PERP, these chemicals are: ethylene dibromide, ethylene dichloride, 1,3-butadiene, tetrachloroethylene, propylene oxide, chloroform, formaldehyde, methylene chloride, dioxane, and benzene. PMID:3447901

  11. Characterization and simulation of fate and transport of selected volatile organic compounds in the vicinities of the Hadnot Point Industrial Area and landfill: Chapter A Supplement 6 in Analyses and historical reconstruction of groundwater flow, contaminant fate and transport, and distribution of drinking water within the service areas of the Hadnot Point and Holcomb Boulevard Water Treatment Plants and vicinities, U.S. Marine Corps Base Camp Lejeune, North Carolina

    USGS Publications Warehouse

    Jones, L. Elliott; Suárez-Soto, René J.; Anderson, Barbara A.; Maslia, Morris L.

    2013-01-01

    This supplement of Chapter A (Supplement 6) describes the reconstruction (i.e. simulation) of historical concentrations of tetrachloroethylene (PCE), trichloroethylene (TCE), and benzene3 in production wells supplying water to the Hadnot Base (USMCB) Camp Lejeune, North Carolina (Figure S6.1). A fate and transport model (i.e., MT3DMS [Zheng and Wang 1999]) was used to simulate contaminant migration from source locations through the groundwater system and to estimate mean contaminant concentrations in water withdrawn from water-supply wells in the vicinity of the Hadnot Point Industrial Area (HPIA) and the Hadnot Point landfill (HPLF) area.4 The reconstructed contaminant concentrations were subsequently input into a flow-weighted, materials mass balance (mixing) model (Masters 1998) to estimate monthly mean concentrations of the contaminant in finished water 5 at the HPWTP (Maslia et al. 2013). The calibrated fate and transport models described herein were based on and used groundwater velocities derived from groundwater-flow models that are described in Suárez-Soto et al. (2013). Information data pertinent to historical operations of water-supply wells are described in Sautner et al. (2013) and Telci et al. (2013).

  12. Sanitary Landfill Groundwater Monitoring Report, Fourth Quarter 1999 and 1999 Summary

    SciTech Connect

    Chase, J.

    2000-03-13

    A maximum of thirty eight-wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill Area at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Water Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Iron (Total Recoverable), Chloroethene (Vinyl Chloride) and 1,1-Dichloroethane were the most widespread constituents exceeding the Final Primary Drinking Water Standards during 1999. Trichloroethylene, 1,1-Dichloroethylene, 1,2-Dichloroethane, 1,4-Dichlorobenzene, Aluminum (Total Recoverable), Benzene, cis-1,2-Dichloroethylene, Dichlorodifluoromethane, Dichloromethane (Methylene Chloride), Gross Alpha, Mercury (Total Recoverable), Nonvolatile Beta, Tetrachloroethylene, Total Organic Halogens, Trichlorofluoromethane, Tritium also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill is to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 144.175 ft/year during first quarter 1999 and 145.27 ft/year during fourth quarter 1999.

  13. Household solvent products: a shelf survey with laboratory analysis. Final report, October 1984-July 1987

    SciTech Connect

    Maklan, D.M.; Steele, D.H.; Dietz, S.K.; Brown, G.L.; Fallah, S.

    1987-07-01

    This study was conducted to provide information on the incidence and concentration of six chlorocarbons in common household products. The objectives of the study were to: (1) determine which categories of consumer products contain the chemical methylene chloride and/or five potential substitute solvents (1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, carbon tetrachloride, and 1,1,2-trichlorotrifluoroethane); and (2) analyze brands representing each product category to determine the concentration of these chemicals in household products. A national sample of household products was selected and laboratory tested to determine the incidence and concentration of the six target chlorocarbons. The following are some of the major findings. Fifty-eight percent of the 67 product categories had at least one brand test positive for one or more of the target analytes. Thirty-four percent of the 1026 brands tested positive for at least one of the six target chlorocarbons. Thirty-four percent of the brands tested positive for methylene chloride, 14% tested positive for 1,1,1-trichloroethane, and less than 4% of the brands were positive on any of the remaining four chlorocarbons. The concentration of analyte varied considerably between brands of the same product category. Only 56% of the brands with chlorocarbons were so labeled.

  14. Mechanism of alternating copolymerization of methyl methacrylate with styrene in the presence of diethylaluminum chloride

    SciTech Connect

    Zubov, V.P.; Lachinov, M.B.; Ignatova, E.V.; Georgiev, G.S.; Golubev, V.B.; Kabanov, V.A.

    1982-03-01

    A kinetic study of the propagation mechanism of the alternating copolymerization of styrene (St) with methyl methacrylate (MMA) in the presence of a complexing agent (diethylaluminum chloride, DEAC) in bulk and in tetrachloroethylene solutions at a molar ratio DEAC/MMA = 0.5 has been carried out. It has been shown that the copolymerization is a chain radical process characterized by a short active-center lifetime, bimolecular termination, and high rate of chain transfer to the complexed MMA. A kinetic scheme has been proposed for the propagation mechanism of alternating copolymerization in the presence of a complexing agent not requiring independent measurements of the equilibrium constant of complexation. It has been found that spontaneous and uv-initiated copolymerizations in the system have different mechanisms of initiation and a common mechanism of propagation. The propagation proceeds by addition of single monomers as well as donor-acceptor complexes of the comonomers to the propagation radicals, with the first mechanism being predominant. Inclusion of the monomers in the complex leads to an increase of the St reactivity and to a decrease of the MMA reactivity in propagation to the corresponding macroradicals in comparison with the reactivity of the free monomers. A number of kinetic and statistical parameters of the propagation reaction have been calculated.

  15. Complete degradation of polychlorinated hydrocarbons by a two-stage biofilm reactor.

    PubMed Central

    Fathepure, B Z; Vogel, T M

    1991-01-01

    A two-stage anaerobic-aerobic biofilm reactor successfully degraded a mixture of chlorinated organic compounds to water-soluble metabolic intermediates and carbon dioxide. Reductive dechlorination of hexachlorobenzene (HCB), tetrachloroethylene (PCE), and chloroform (CF) occurred on all tested primary carbon sources such as glucose, methanol, and acetate. However, the extent of dechlorination was maximum when the anaerobic biofilm column was fed acetate as a primary carbon source. HCB, PCE, and CF were dechlorinated to the levels of tri- and dichlorinated products (99, 80, and 32%, respectively) with acetate in the feed. This is important, since these less-chlorinated compounds can be metabolized by the aerobic biofilm. The effluent from the anaerobic biofilm column was fed directly into the aerobic column. After both columns, the total amount transformed into nonvolatile intermediates and carbon dioxide was 94, 96, and 83% for [14C]HCB, [14C]trichloroethylene, and [14C]CF, respectively. This research shows the potential application of this novel two-stage bioreactor system for treating groundwaters and industrial effluents composed of highly chlorinated aliphatic and aromatic hydrocarbons. PMID:1785918

  16. Test plan for single well injection/extraction characterization of DNAPL

    SciTech Connect

    Looney, B.B.; Jerome, K.M.; Burdick, S.; Rossabi, J.; Jarosch, T.R.; Eddy-Dilek, C.A.

    1995-12-01

    Soils and groundwater beneath an abandoned Process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLS, or dense non aqueous Phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small contained spill sites) is the only ``proven`` cleanup method. New cleanup approaches based on enhanced removal by surfactants and/or alcohols have been proposed and tested at the pilot scale. As described below, carefully designed experiments similar to the enhanced removal methods may provide important characterization information on DNAPLs.

  17. Modelling of sequential groundwater treatment with zero valent iron and granular activated carbon.

    PubMed

    Bayer, Peter; Finkel, Michael

    2005-06-01

    Multiple contaminant mixtures in groundwater may not efficiently be treated by a single technology if contaminants possess rather different properties with respect to sorptivity, solubility, and degradation potential. An obvious choice is to use sequenced units of the generally accepted treatment materials zero valent iron (ZVI) and granular activated carbon (GAC). However, as the results of this modelling study suggest, the required dimensions of both reactor units may strongly differ from those expected on the grounds of a contaminant-specific design. This is revealed by performing an analysis for a broad spectrum of design alternatives through numerical experiments for selected patterns of contaminant mixtures consisting of monochlorobenzene, tetrachloroethylene, trichloroethylene (TCE), cis-1,2-dichloroethylene (cis-DCE), and vinyl chloride (VC). It is shown that efficient treatment can be achieved only if competitive sorption effects in the GAC unit as well as the formation of intermediate products in the ZVI unit are carefully taken into account. Cost-optimal designs turned out to vary extremely depending on the prevailing conditions concerning contaminant concentrations, branching ratios, and unit costs of both reactor materials. Where VC is the critical contaminant, due to high initial concentration or extensive production as an intermediate, two options are cost-effective: an oversized ZVI unit with an oversized GAC unit or a pure GAC reactor. PMID:15949610

  18. Compendium of technical papers on the reductive dechlorination of chlorinated solvents. Final report, August 1993--October 1996

    SciTech Connect

    Gossett, J.M.; Zinder, S.H.

    1997-08-01

    This compendium of technical papers represents three years of work in the investigation of the anaerobic biodegradation of tetrachloroethylene (PCE). Cornell researchers had previously developed a methanol (MeOH)/PCE enrichment culture which dechlorinates high concentrations of PCE and other chlorinated ethenes to ethene (ETH), representing complete detoxification. This culture dechlorinates PCE at unprecedented, high rates with efficient use of MeOH as the electron donor for reductive dechlorination. However, research at Cornell showed that MeOH was not the direct donor for PCE dechlorination, but rather H{sub 2}. MeOH and other reductants found to support dechlorination merely serve as H{sub 2} precursors. Three alternative electron donors (ethanol, butyrate, and lactate) were evaluated to circumvent the problem of methanogenic competition for the supplied donor. The final selected substrate was used in a continuous-flow reactor study with the H{sub 2}/PCE enrichment culture. Engineering studies examined the kinetics of chlorinated ETH utilization with emphasis on vinyl chloride (VC) dechlorination to ETH. Acclimation and induction issues were explored. Microbiological studies towards a better understanding of the nature and the requirements of the dechlorinating organisms were explored. The nutrition of the dechlorinating organisms was examined with the goal of finding and identifying reliable high-potency sources if the nutrients.

  19. Sewer Gas: An Indoor Air Source of PCE to Consider During Vapor Intrusion Investigations

    PubMed Central

    Pennell, Kelly G.; Scammell, Madeleine Kangsen; McClean, Michael D.; Ames, Jennifer; Weldon, Brittany; Friguglietti, Leigh; Suuberg, Eric M.; Shen, Rui; Indeglia, Paul A.; Heiger-Bernays, Wendy J.

    2013-01-01

    The United States Environmental Protection Agency (USEPA) is finalizing its vapor intrusion guidelines. One of the important issues related to vapor intrusion is background concentrations of volatile organic chemicals (VOCs) in indoor air, typically attributed to consumer products and building materials. Background concentrations can exist even in the absence of vapor intrusion and are an important consideration when conducting site assessments. In addition, the development of accurate conceptual models that depict pathways for vapor entry into buildings is important during vapor intrusion site assessments. Sewer gas, either as a contributor to background concentrations or as part of the site conceptual model, is not routinely evaluated during vapor intrusion site assessments. The research described herein identifies an instance where vapors emanating directly from a sanitary sewer pipe within a residence were determined to be a source of tetrachloroethylene (PCE) detected in indoor air. Concentrations of PCE in the bathroom range from 2.1 to 190 ug/m3 and exceed typical indoor air concentrations by orders of magnitude resulting in human health risk classified as an “Imminent Hazard” condition. The results suggest that infiltration of sewer gas resulted in PCE concentrations in indoor air that were nearly two-orders of magnitude higher as compared to when infiltration of sewer gas was not known to be occurring. This previously understudied pathway whereby sewers serve as sources of PCE (and potentially other VOC) vapors is highlighted. Implications for vapor intrusion investigations are also discussed. PMID:23950637

  20. Physiologically-based pharmacokinetic and toxicokinetic models in cancer risk assessment.

    PubMed

    Krishnan, Kannan; Johanson, Gunnar

    2005-01-01

    Physiologically-based pharmacokinetic (PBPK) and toxicokinetic models are increasingly being used for the conduct of high dose to low dose and interspecies extrapolations required in cancer risk assessment. These models, by simulating tissue dose of toxic chemicals, help address the uncertainty associated with the default approaches for interspecies and high dose to low dose extrapolations. The applicability of PBPK models in cancer risk assessment has been demonstrated with a number of chemicals (e.g., acrylonitrile, 2-butoxyethanol, chloroform, 1,4-dioxane, methyl chloroform, methylene chloride, styrene, trichloroethylene, tetrachloroethylene, vinyl chloride, vinyl acetate). Recent advances in PBPK modeling facilitate the consideration of population distribution of parameter values, age-dependent changes in physiology and metabolism, multi-route exposures as well as multichemical interactions for application in cancer risk assessment. Whereas the average values for various input parameters have been used to evaluate the age-dependency of tissue dose, the Markov Chain Monte Carlo technique can be applied to address variability and uncertainty in parameter estimates, thus facilitating a more accurate estimation of cancer risk in the population. The PBPK models also uniquely facilitate the simulation of tissue dose, and thereby cancer risks, associated with multi-route and multichemical exposure situations. Overall, the recent advances reviewed in this article point to the continued enhancement of the scientific basis and applicability of PBPK models in cancer risk assessment. PMID:16291521

  1. Test plan for Geo-Cleanse{reg_sign} demonstration (in situ destruction of dense non-aqueous phase liquid (DNAPL))

    SciTech Connect

    Jerome, K.M.; Looney, B.B.; Accorsi, F.; Dingens, M.; Wilson, J.T.

    1996-09-01

    Soils and groundwater beneath an abandoned process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLs, or dense non-aqueous phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small contained spill sites) is the only proven cleanup method. New cleanup approaches based on destruction of DNAPL either in situ or ex situ have been proposed and tested at the pilot scale. The proposed demonstration, as described in this report will evaluate the applicability to DNAPL plumes of a technology proven for in situ destruction of light non-aqueous phase liquids (LNAPLs) such as oils.

  2. Development of a method for assessing the toxicity of volatile organic contaminants (VOCs) to soil biota

    SciTech Connect

    Cureton, P.M. [Environment Canada, Ottawa, Ontario (Canada). Evaluation and Interpretation Branch; Lintott, D.; Balch, G.; Goudey, S. [HydroQual Labs. Ltd., Calgary, Alberta (Canada)

    1994-12-31

    A method was developed to assess the toxicity of VOCs to plants and earthworms (survival of Eisenia foetida). The procedures followed were based on Greene et al. Gas samples for head space analyses were removed, at test initiation a termination, through a bulkhead fitting in the lid equipped with septa. Treatment levels were prepared, at low temperature to minimize volatilization, by spiking a soil sample with the compound of interest and then serially diluting it with clean soil. Root elongation tests were conducted on filter paper supported by 70 mesh silica sand spiked with the volatile of interest. Soils were then inundated with water, shaken with heating, and the headspace reanalyzed for the total contaminant concentration in the test system (total equals headspace plus adsorbed). Enclosing the seeds and worms in containers did not appear to have detrimental effects. VOCs tested included benzene, xylene, toluene, ethylbenzene, tetrachloroethylene, and 1,1,2-trichloroethylene. Each test was repeated three times with different batches of soil, seed lots and worms from different colonies. Endpoints derived based on nominal and measured concentrations included: NOEC, LOEC, LC{sub 50} and LC{sub 25} for earthworm mortality and EC{sub 50} and EC{sub 25} for emergence and root elongation.

  3. Stress survival of a genetically engineered Pseudomonas in soil slurries: Cytochrome P-450cam-catalyzed dehalogenation of chlorinated hydrocarbons

    SciTech Connect

    Rattan, K.; Shanker, R.; Khanna, P.; Atkins, W.M.

    1999-10-01

    Biological treatment of hazardous chemical wastes has potential as an effective, practical, and economically viable process in above the ground treatment systems that consist of both genetically engineered microorganisms (GEMs) and bioreactors with process control instruments to create ideal conditions for biodegradation. A strain of Pseudomonas putida coexpressing cytochrome P-450cam and luciferase (lux) that provides both the reductive detoxification potential of the hemoprotein and a mechanism for its reduction to survive and remain metabolically competent under nutrient stress in soil slurry microcosms. More than 74% of the cells of engineered Pseudomonas were culturable after 7 days of multiple nutrient (C,N,P) starvation. The diagnostic luminescence and carbon monoxide-difference spectra for the two engineered traits could be detected in a significant fraction of the surviving population. The GEM could be revived after repeated desiccation and starvation using Luria broth, benzoate, or citrate as nutrients. Soil slurries inoculated with the GEM transformed hexachloroethane (HCE) to tetrachloroethylene (tetraCE) 8--10 fold faster than uninoculated slurries. The GEM also transformed the insecticide, {gamma}-HCH ({gamma}-3,4,5,6-hexachlorocyclhexene), to {gamma}-3,4,5,6-tetrachlorocyclohexene ({gamma}tetraCH) in soil slurries under subatmospheric conditions. These results indicate that GEMs can be constructed with broad substrate range detoxification catalysts such as cytochrome P-450 for remediation.

  4. 1996 PAMS hydrocarbon QA studies in EPA Region II: Part II. Trends and insights

    SciTech Connect

    Teitz, A.; Kantz, M. [Environmental Protection Agency, Edison, NJ (United States)

    1997-12-31

    Comparison of ambient air samples between EPA Region II and the PAMS monitoring organizations within the Region, and comparisons among EPA Regions I, II, and III, revealed the following analytical trends: (1) Agreement between laboratories was typically between 10-20% for many of the PAMS analytes found at higher concentrations, i.e., butane, isopentane, benzene, toluene, and m/p-xylene; (2) Nafion dryer systems tended to underestimate the amount of acetylene by 35-50%; (3) Isobutylene co-elution with 1-butene proved difficult to resolve unless a 100 meter DB-1 or a regular length PLOT GC column was used; (4) Organizations that monitor for polar compounds found that co-elution of ethanol/acetone can interfere with the analysis of 1-pentene; (5) Analytical systems capable of polar analyses can have co-elution and/or misidentification of these aldehydes, typically in the styrene/heptanal/o-xylene regions of the chromatogram; and (6) Tetrachloroethylene was found to interfere with octane quantitation in some analyses.

  5. Aerobic/anaerobic/aerobic sequenced biodegradation of a mixture of chlorinated ethenes, ethanes and methanes in batch bioreactors.

    PubMed

    Frascari, Dario; Fraraccio, Serena; Nocentini, Massimo; Pinelli, Davide

    2013-01-01

    A novel aerobic/anaerobic/aerobic treatment was implemented in batch reactors containing aquifer materials from a site contaminated by tetrachloroethylene (PCE), trichloroethylene (TCE), vinyl chloride (VC), 1,1,2-trichloroethane (1,1,2-TCA) and chloroform (CF). Consortia grown aerobically on methane, propane, n-pentane and n-hexane completely biodegraded the chlorinated solvent mixture, via aerobic cometabolism of VC, CF, TCE and 1,1,2-TCA, followed by PCE reductive dechlorination (RD) to 1,2-cis-dichlorothylene (cis-DCE) or TCE, and cis-DCE/TCE cometabolism in a further aerobic phase. n-Hexane was the best substrate. No electron donor was supplied for RD, which likely utilized cellular material produced during the aerobic phase. Chloride release was stoichiometric with chlorinated solvent biodegradation. According to the Lepidium sativum ecotoxicity test, a decreased toxicity was observed with propane, n-pentane and n-hexane, but not methane. A kinetic study of PCE RD allowed to estimate the PCE maximum specific rate (0.57 ± 0.07 mg mg(protein)(-1) day(-1)) and half-saturation constant (6.7 ± 1.5 mg L(-1)). PMID:23201903

  6. Mid-infrared chemical sensors utilizing plasma-deposited fluorocarbon membranes.

    PubMed

    Dobbs, Gary T; Balu, Balamurali; Young, Christina; Kranz, Christine; Hess, Dennis W; Mizaikoff, Boris

    2007-12-15

    In this study, plasma-polymerized films are evaluated as enrichment membranes deposited at the surface of mid-infrared transparent waveguides for liquid-phase chemical sensing utilizing evanescent field absorption spectroscopy. Fluorocarbon films were deposited onto zinc selenide (ZnSe) waveguides from plasma-polymerized pentafluoroethane (CF(3)CHF(2)) vapor. Excellent optical transmission of ZnSe waveguides after plasma deposition confirms compatibility of the infrared transparent substrate with this low-temperature, solvent-free film deposition process. The liquid-phase enrichment characteristics for plasma membranes were investigated via evanescent field absorption spectroscopy of a model analyte (tetrachloroethylene); the limits of detection were below 300 ppb (v/v) in water. Plasma-polymerized films are known for their excellent mechanical and chemical stability, while offering tunable chemical and physical characteristics during the deposition process. Future application of this coating strategy for depositing robust enrichment membranes with tunable batch production capability imparts an attractive route toward application-oriented development of next-generation mid-infrared chemical sensors applicable in harsh environments. PMID:18020310

  7. Advanced oxidation processes. Test of a kinetic model for the oxidation of organic compounds with ozone and hydrogen peroxide in a semibatch reactor

    SciTech Connect

    Glaze, W.H.; Kang, J.W.

    1989-01-01

    Experimental data are presented to test a kinetic model of the OE/H{sub 2}O{sub 2} process in a semibatch reactor. The effect of bicarbonate and carbonate ions is measured and found to be in concurrence with model predictions. The effect of pH in the ozone mass-transfer-limited region was examined in bicarbonate-spiked distilled water. Since the reaction is mass transfer limited, the primary effect above pH 7 is the result of changes in the distribution of inorganic carbon species which are OH-radical scavengers. Below pH 7, there is a lag period during which ozone and peroxide increase until the chain reaction begins. The effects of chloride ion and the concentration of radical scavengers other than carbonate species in ground waters are also measured. The mass-transfer/reaction rate model has been used to estimate rate constants for the reaction of hydroxyl radicals with trichloroethylene, 1,2-dibromoethane, 1,2-dibromo-3-chloropropane, carbon tetrachloride, and two bicyclic alcohols, 2-methylisoborneol and geosmin. While the model developed for the distilled water system was successful in predicting the rate of tetrachloroethylene (PCE) oxidation and the concentration of residual ozone and peroxide in regions I and III, respectively, there are several features of the model that remain unresolved when the matrix is changed to a real surface or ground water. This and subsequent papers will investigate these effects.

  8. By-products of oxidation processes in water and wastewater treatment

    SciTech Connect

    Glaze, H.; Le Lacheur, R.M.; Pullin, J.J. [Univ. of North Carolina, Chapel Hill, NC (United States)] [and others

    1995-12-31

    In a series of papers beginning with the seminal article in Science in 1975, Hoigne and co-workers developed the concept that ozone chemistry in the aqueous phase was fundamentally different from ozone chemistry in non-aqueous solvents or in the gas phase. The distinction is due to the formation of reactive intermediates formed when ozone decomposes in water, a phenomenon which Hoigne et al. also elucidated in subsequent papers. Since this pioneering work, only a few articles have examined ozone reactions with organic or inorganic chemicals in water in sufficient detail to sort out the interplay of ozone versus hydroxyl radical chemistry. Indeed, although the literature is replete with articles on the kinetics of OH reactions, relatively few have examined the detailed chemistry beyond the first step. This paper will describe recent studies in our laboratory which illustrate facets of ozone and OH-radical chemistry that Hoigne anticipated. We will summarize the reaction of ozone with amino acids in aqueous solution, the reaction of OH radicals with a compound (p-chlorobenzoic acid, PCBA) that apparently produces a propagating agent (superoxide) that {open_quotes}promotes{close_quotes} the chain radical decomposition of ozone, the formation of haloaldehydes and haloacetic acids from AOP destruction of tri- and tetrachloroethylene, and preliminary studies on the photolysis and OH radical products from 1,3,5-trinitro-sym-triazacyclohexane (RDX).

  9. Current Intelligence Bulletins: summaries

    SciTech Connect

    Not Available

    1986-07-24

    Summaries are provided for the 47 Current Intelligence Bulletins issued to date by NIOSH; any revisions in NIOSH policy made after a bulletin was issued are included. Subjects of the bulletins include the following: chloroprene; trichloroethylene; ethylene-dibromide; chrome pigment; asbestos exposure; hexamethylphosphoric-triamide; polychlorinated biphenyls; 4,4'-diaminodipheylmethane; chloroform; radon daughters; dimethylcarbamoyl-chloride; diethylcarbamoyl-chloride; explosive azide hazard; inorganic arsenic; nitrosamines; metabolic precursors of beta-naphtylamine; 2-nitropropane; acryonitrile; 2,4-diaminoanisole; tetrachloroethylene; trimellitic-anhydride; ethylene-thiourea; ethylene-dibromide and disulfiram, toxic interaction; direct blue 6, direct black 38, direct brown 95, benzidine derived dyes; ethylene-dichloride; NIAX catalyst ESN; chloroethanes, review of toxicity; vinyl halides, carcinogenicity; glycidyl ethers; epichlorohydrin; smoking and the occupational environment; arsine poisoning in the workplace; radiofrequency sealers and heaters; formaldehyde; ethylene-oxide; silica flour; ethylene-dibromide; vibration syndrome; glycol ethers; 2,3,7,8-tetrachlorodibenzo-p-dioxin; 1,3-butadiene; cadmium; monohalomethanes; dinitrotoluenes; polychlorinated biphenyls in electrical equipment fires or failures; methylene-chloride; and 4,4' methylenedianiline.

  10. Site characterization program at the radioactive waste management complex of the Idaho National Engineering Laboratory

    SciTech Connect

    McElroy, D.L.; Rawson, S.A.; Hubbell, J.M.; Minkin, S.C.; Baca, R.G.; Vigil, M.J.; Bonzon, C.J.; Landon, J.L.; Laney, P.T.

    1989-07-01

    The Radioactive Waste Management Complex (RWMC) Site Characterization Program is a continuation of the Subsurface Investigation Program (SIP). The scope of the SIP has broadened in response to the results of past work that identified hazardous as well as radionuclide contaminants in the subsurface environment and in response to the need to meet regulatory requirements. Two deep boreholes were cored at the RWMC during FY-1988. Selected sediment samples were submitted for Appendix IX of 40 CFR Part 264 and radionuclide analyses. Detailed geologic logging of archived core was initiated. Stratigraphic studies of the unsaturated zone were conducted. Studies to determine hydrologic properties of sediments and basalts were conducted. Geochemical studies and analyses were initiated to evaluate contaminant and radionuclide speciation and migration in the Subsurface Disposal Area (SDA) geochemical environment. Analyses of interbed sediments in boreholes D15 and 8801D did not confirm the presence of radionuclide contamination in the 240-ft interbed. Analyses of subsurface air and groundwater samples identified five volatile organic compounds of concern: carbon tetrachloride, trichloroethylene, 1,1,1-trichloroethane, chloroform, and tetrachloroethylene. 33 refs., 5 figs., 2 tabs.

  11. Preparation and characterization of high contrast electrophoretic display suspension containing charged black-and-white nanoparticles

    NASA Astrophysics Data System (ADS)

    Yao, Xiao-Nan; Wang, Jian-Ping; Zhang, Xing-Xiang; Wang, Xue-Chen

    2009-07-01

    In this study, TiO2 nanoparticles with sizes ranging from 300- 400nm were modified by two-step dispersion polymerization using poly (styrene-co-divinylbenzene)-methyl methacrylate [P (St-co-DVB)-MMA] as shell. And core, carbon black (CB) nanoparticles with size ranging from 30-50nm and polymer shell poly (methacrylic acid) [PMAA] were prepared by grafting polymerization, too. Modified nanoparticles were characterized on structure, mean particle size and size distribution, morphology with FT-IR, TEM, and image analyzer. Furthermore, modified TiO2 as negatively charged electrophoretic particles and CB nanoparticles as cationically charged electrophoretic particles were homodispersed in tetrachloroethylene (TCE) to make the electrophoretic display suspension with Span-80 as dispersant and OLOA 1200 as charge control agent. The zeta potential and mobility of white (TiO2) and black (CB) charged particles were measured to be -61.4 mV, 9.50×10-6 cm2 /V s and 12.8 mV, 1.98×10-6 cm2 /V s by using an electrophoresis test device, respectively. Final, the electric response behaviors of the electrophoretic display suspension were studied under electrostatic field. The black-and-white particles moved quickly and reversibly inside ITO electrodes while the electric field alternated.

  12. Toluidine red nanoparticles and their application in electrophoretic display.

    PubMed

    An, Wu-Wei; Le, Yuan; Chen, Jian-Feng

    2011-12-01

    Toluidine red pigment nanoparticles were prepared by anti-solvent precipitation and were modified by different surfactants aimed to use as the electrophoretic particles. Experimental conditions have been discussed in this paper including the effect of different surfactants, the concentration of surfactants, the reaction temperature and the agitation rate. Binary mixtures of organic solvents have been selected as suspending medium to improve the dispersion stability of the prepared particles. The produced nanoparticles have been characterized by scanning electron microscopy, laser diffractometer and electrophoretic display measuring system. The results indicated that the prepared particles modified by alkyl hydroxy oximido acid are in the average size of 80 nm with a spherical shape within narrow particle size distribution. The optimum content of AHOA, reaction temperature agitation rate are 3.75 g/L, 20 degrees C and 900 rpm, respectively. The prepared nanoparticles exhibit superior electrophoretic properties. Finally, the sedimentation of prepared particles dispersed into binary mixtures of tetrachloroethylene (C2Cl4) and cyclohexane is 4.76% for 2 months. PMID:22409027

  13. Sustainable in-well vapor stripping: A design, analytical model, and pilot study for groundwater remediation

    NASA Astrophysics Data System (ADS)

    Sutton, Patrick T.; Ginn, Timothy R.

    2014-12-01

    A sustainable in-well vapor stripping system is designed as a cost-effective alternative for remediation of shallow chlorinated solvent groundwater plumes. A solar-powered air compressor is used to inject air bubbles into a monitoring well to strip volatile organic compounds from a liquid to vapor phase while simultaneously inducing groundwater circulation around the well screen. An analytical model of the remediation process is developed to estimate contaminant mass flow and removal rates. The model was calibrated based on a one-day pilot study conducted in an existing monitoring well at a former dry cleaning site. According to the model, induced groundwater circulation at the study site increased the contaminant mass flow rate into the well by approximately two orders of magnitude relative to ambient conditions. Modeled estimates for 5 h of pulsed air injection per day at the pilot study site indicated that the average effluent concentrations of dissolved tetrachloroethylene and trichloroethylene can be reduced by over 90% relative to the ambient concentrations. The results indicate that the system could be used cost-effectively as either a single- or multi-well point technology to substantially reduce the mass of dissolved chlorinated solvents in groundwater.

  14. Phase behavior of chlorinated solvent + water + alcohol mixtures with application to alcohol flushing

    SciTech Connect

    Hayden, N.J.; Diebold, J.; Noyes, G. [Univ. of Vermont, Burlington, VT (United States). Dept. of Civil and Environmental Engineering] [Univ. of Vermont, Burlington, VT (United States). Dept. of Civil and Environmental Engineering

    1999-09-01

    Alcohol flushing is a new in-situ remediation technique for the removal of water-immiscible solvents from contaminated soil and groundwater. Understanding the changes in the physical and chemical properties of chlorinated solvents and the aqueous-phase solution during flushing is prerequisite for the successful application of this technology. The overall objectives of these experiments were to characterize the ternary-phase behavior, interfacial tension, viscosity, and density for mixtures containing a chlorinated solvent, water and alcohol. Two chlorinated solvents were used: tetrachloroethylene and trichloroethylene. The alcohols studied included methanol, ethanol, and propan-2-ol. Results showed that the single-phase region of the ternary relationships increased as the molecular weight of the alcohol increased. The interfacial tension between the chlorinated solvents and aqueous solutions decreased with increasing alcohol concentration and increasing molecular weight of the alcohol. Changes in the viscosity of water + alcohol mixtures due to the addition of the solvents were only evident at high alcohol concentrations. Small changes in density were noted for the chlorinated solvents in equilibrium with water + alcohol solutions except in the case of trichloroethylene and propan-2-ol solutions, which exhibited considerable swelling.

  15. Health assessment for Welsh Road/Barkman Landfill, Honey Brook, Chester County, Pennsylvania, Region 3. CERCLIS No. PAD980829527. Preliminary report

    SciTech Connect

    Not Available

    1988-12-02

    The Welsh Road/Barkman Landfill site in Honey Brook, Pennsylvania was an unpermitted residential and commercial refuse disposal facility that operated from 1963 to sometime in the 1980s. After 1977, the landfill continued to operate in defiance of legal action to support a closure plan. Various investigations conducted in the 1980s revealed that industrial and hazardous waste had been accepted by the site. The environmental contamination on-site consists of copper, lead, 1,2-dichloropropane, toluene, chloroform and methylene chloride in drummed wastes; and mercury, toluene, dichlorofluoromethane, methylene chloride, trichlorofluoromethane, 5-methyl-2-hexanone, trichloroethylene, 1,2-dichloroethane, and 1,3,5-cycloheptatriene in groundwater. One time sampling indicated the presence of volatile compounds in air (hydrogen chloride and chloroform). The environmental contamination off-site consists of cadmium in sediment; and chloromethane, chloroform, xylenes, dichlorofluoromethane, 1,1-dichloroethane, tetrachloroethylene, p-cresol, toluene, methyl isobutyl ketone, di-n-butyl phthalate, lead, mercury, and zinc in residential well water. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances via contaminated groundwater, surface water, soil, sediment, and airborne gases, vapors, and particulate.

  16. Savannah River Site A/M Area Southern Sector Characterization Cone Penetrometer Report

    SciTech Connect

    Raabe, B.A. [Westinghouse Savannah River Company, Aiken, SC (United States)

    1993-05-01

    The Savannah River Site (SRS) is located in the Atlantic Coastal Plaingeologic province. This area is characterized by low relief, predominantly unconsolidated sediments of Cretaceous though Tertiary age. A multiple aquifer system underlies the A/M Area and affects the definition and distribution of a contaminant plume. The water table and uppermost confined aquifer (Steed Pond Aquifer) are contaminated with elevated concentrations of trichloroethylene(TCE) and tetrachloroethylene (PCE) and their associated compounds. The deeper aquifers in this area have less widely spread chlorinated hydrocarbon contamination.Cone penetrometer testing was selected as the method of investigation because it is minimally invasive, offers advanced technological capabilities in gathering lithologic data, and offers groundwater sampling capabilities. CPT testing utilizes a hydraulic push tool system. The probe collects real-time data that is processed by computer into soil/lithology classifications. The system can also be used to collect sediment and soil vapor samples although these features were not utilized during this project. Advantages of the CPT system include a small borehole diameter which minimizes cross-contamination of lithologic units, virtual elimination of drill cuttings and fluids that require disposal, collection of various types of undisturbed sediment and water samples and plotting of hydrostratigraphic and lithologic data while in the field.

  17. In planta passive sampling devices for assessing subsurface chlorinated solvents.

    PubMed

    Shetty, Mikhil K; Limmer, Matt A; Waltermire, Kendra; Morrison, Glenn C; Burken, Joel G

    2014-06-01

    Contaminant concentrations in trees have been used to delineate groundwater contaminant plumes (i.e., phytoscreening); however, variability in tree composition hinders accurate measurement of contaminant concentrations in planta, particularly for long-term monitoring. This study investigated in planta passive sampling devices (PSDs), termed solid phase samplers (SPSs) to be used as a surrogate tree core. Characteristics studied for five materials included material-air partitioning coefficients (Kma) for chlorinated solvents, sampler equilibration time and field suitability. The materials investigated were polydimethylsiloxane (PDMS), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyoxymethylene (POM) and plasticized polyvinyl chloride (PVC). Both PDMS and LLDPE samplers demonstrated high partitioning coefficients and diffusivities and were further tested in greenhouse experiments and field trials. While most of the materials could be used for passive sampling, the PDMS SPSs performed best as an in planta sampler. Such a sampler was able to accurately measure trichloroethylene (TCE) and tetrachloroethylene (PCE) concentrations while simultaneously incorporating simple operation and minimal impact to the surrounding property and environment. PMID:24268175

  18. Immobilization of proteins on glow discharge treated polymers

    NASA Astrophysics Data System (ADS)

    Kiaei, D.; Safranj, A.; Chen, J. P.; Johnston, A. B.; Zavala, F.; Deelder, A.; Castelino, J. B.; Markovic, V.; Hoffman, A. S.

    Certain glow discharge-treated surfaces have been shown to enhance retention of adsorbed proteins. On the basis of this phenomenon, we have investigated the possibility of immobilizing (a) albumin for developing thromboresistant and non-fouling surfaces, (b) antibodies for immuno-diagnostic assays and (c) enzymes for various biosensors and industrial bioprocesses. Albumin retention was highest on surfaces treated with tetrafluoroethylene (TFE) compared to untreated surfaces or other glow discharge treatments studied. Preadsorption of albumin on TFE-treated surfaces resulted in low fibrinogen adsorption and platelet adhesion. IgG retention was also highest on TFE-treated surfaces. The lower detection limits of both malaria antigen and circulating anodic antigen of the schistosomiasis worm were enhanced following glow discharge treatment of the assay plates with TFE. Both TFE and tetrachloroethylene (TCE) glow discharge treated surfaces showed high retention of adsorbed horseradish peroxidase (HRP). However, the retained specific activity of HRP after adsorption on TCE-treated surfaces was remarkably higher than on TFE-treated surfaces.

  19. Testing of stack-unit/aquifer sensitivity analysis using contaminant plume distribution in the subsurface of Savannah River Site, South Carolina, USA

    USGS Publications Warehouse

    Rine, J.M.; Shafer, J.M.; Covington, E.; Berg, R.C.

    2006-01-01

    Published information on the correlation and field-testing of the technique of stack-unit/aquifer sensitivity mapping with documented subsurface contaminant plumes is rare. The inherent characteristic of stack-unit mapping, which makes it a superior technique to other analyses that amalgamate data, is the ability to deconstruct the sensitivity analysis on a unit-by-unit basis. An aquifer sensitivity map, delineating the relative sensitivity of the Crouch Branch aquifer of the Administrative/Manufacturing Area (A/M) at the Savannah River Site (SRS) in South Carolina, USA, incorporates six hydrostratigraphic units, surface soil units, and relevant hydrologic data. When this sensitivity map is compared with the distribution of the contaminant tetrachloroethylene (PCE), PCE is present within the Crouch Branch aquifer within an area classified as highly sensitive, even though the PCE was primarily released on the ground surface within areas classified with low aquifer sensitivity. This phenomenon is explained through analysis of the aquifer sensitivity map, the groundwater potentiometric surface maps, and the plume distributions within the area on a unit-by- unit basis. The results of this correlation show how the paths of the PCE plume are influenced by both the geology and the groundwater flow. ?? Springer-Verlag 2006.

  20. Visualization and Time-Series Analysis of Ground-Water Data for C-Area, Savannah River Site, South Carolina, 1984-2004

    USGS Publications Warehouse

    Conrads, Paul A.; Roehl, Edwin A., Jr.; Daamen, Ruby C.; Chapelle, Francis H.; Lowery, Mark A.; Mundry, Uwe H.

    2007-01-01

    In 2004, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, initiated a study of historical ground-water data of C-Area on the Savannah River Site in South Carolina. The soils and ground water at C-Area are contaminated with high concentrations of trichloroethylene and lesser amounts of tetrachloroethylene. The objectives of the investigation were (1) to analyze the historical data to determine if data-mining techniques could be applied to the historical database to ascertain whether natural attenuation of recalcitrant contaminants, such as volatile organic compounds, is occurring and (2) to determine whether inferential (surrogate) analytes could be used for more cost-effective monitoring. Twenty-one years of data (1984-2004) were collected from 396 wells in the study area and converted from record data to time-series data for analysis. A Ground-Water Data Viewer was developed to allow users to spatially and temporally visualize the analyte data. Overall, because the data were temporally and spatially sparse, data analysis was limited to only qualitative descriptions.

  1. On-line analysis of volatile chlorinated hydrocarbons in air by gas chromatography-mass spectrometry Improvements in preconcentration and injection steps.

    PubMed

    Zoccolillo, Lelio; Amendola, Luca; Insogna, Susanna; Pastorini, Elisabetta

    2010-06-11

    An analytical system composed of a cryofocusing trap injector device coupled to a gas chromatograph with mass spectrometric detection (CTI-GC-MS) specific for the on-line analysis in air of volatile chlorinated hydrocarbons (VCHCs) (dichloromethane; chloroform; 1,1,1-trichloroethane; tetrachloromethane; 1,1,2-trichloroethylene; tetrachloroethylene) was developed. The cryofocusing trap injector was the result of appropriate low cost modifications to an original purge-and-trap device to make it suitable for direct air analysis even in the case of only slightly contaminated air samples, such as those from remote zones. The CTI device can rapidly and easily be rearranged into the purge-and-trap allowing water and air analysis with the same apparatus. Air samples, collected in stainless steel canisters, were introduced directly into the CTI-GC-MS system to realize cryo-concentration (at -120 degrees C), thermal desorption (at 200 degrees C) and for the subsequent analysis of volatiles. The operating phases and conditions were customised and optimized. Recovery efficiency was optimized in terms of moisture removal, cold trap temperature and sampling mass flow. The injection of entrapped volatiles was realized through a direct transfer with high chromatographic reliability (capillary column-capillary column). These improvements allowed obtaining limits of detection (LODs) at least one order of magnitude lower than current LODs for the investigated substances. The method was successfully employed on real samples: air from urban and rural areas and air from remote zones such as Antarctica. PMID:20444461

  2. Monitoring polycyclic aromatic hydrocarbons in seawaters and wastewaters using a dispersive liquid-liquid microextraction method.

    PubMed

    Ramos-Dorta, Carmen V; Pino, Verónica; Afonso, Ana M

    2013-01-01

    An evaluation has been made of a dispersive liquid-liquid microextraction (DLLME) procedure for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in different environmental waters including seawaters and wastewaters, using gas-chromatography (GC) with flame-ionization detection (FID). The optimized method requires 18 microL of the extractant solvent tetrachloroethylene (C2Cl4), 1 mL of acetonitrile as dispersive solvent, and 5 mL of aqueous sample. After centrifugation (5 min), 2 microL of the obtained micro-droplet containing the extracted PAHs, which varied from - 15 microL for seawaters to - 9 microL for wastewaters, is directly injected in the GC-FID. The performance of the method is characterized for average extraction efficiencies of 99.0% and 98.1% when analysing real seawaters and wastewaters, respectively, at low spiked levels (3 ng x mL(-1)); and average precision values of 8.4% as relative standard deviation. The performance of the method was also compared with conventional liquid-liquid extraction. The DLLME calibrations have been obtained in different aqueous matrices to thoroughly evaluate the matrix effect. The application of the joint-confidence ellipse F-test showed that seawaters can be simply analysed using DLLME calibrations obtained in the laboratory using deionized water. However, important caution must be taken into account when dealing with wastewater, because of matrix effects. PMID:23837310

  3. Radiolytic and thermal dechlorination of organic chlorides adsorbed on molecular sieve 13X.

    PubMed

    Yamamoto, Y; Tagawa, S

    2001-05-15

    Reductive dechlorination of chlorobenzene (PhCl), trichloroethylene (TCE), tetrachloroethylene (PCE), 1- and 2-chlorobutanes, chloroform, carbon tetrachloride, and 1,1,1- and 1,1,2-trichloroethanes adsorbed on molecular sieve 13X was investigated. The molecular sieve adsorbing the organic chlorides was irradiated with gamma-rays, heated, or allowed to stand at room temperature in a sealed ampule and was then soaked in water. The dechlorination yields were determined from the Cl- concentrations of the supernatant aqueous solutions. It was found that the chlorinated alkanes adsorbed on the molecular sieve are readily dechlorinated on standing at room temperature. The dechlorination at room temperature was limited for TCE and PCE. PhCl was quite stable even at 200 degrees C. gamma-Radiolysis was examined for PhCl, TCE, and PCE at room temperature. The radiation chemical yields of the dechlorination, G(Cl-), were 1.9, 40, and 30 for PhCl, TCE, and PCE, respectively. After 5 h of heating at 200 degrees C, the dechlorination yields for TCE and PCE were 24.5 and 4.3%, respectively. TCE is much more reactive than PCE in the thermal dechlorination, whereas their radiolytic dechlorination yields are comparable. The pH of the supernatant solutions decreased along with the dechlorination. PMID:11393996

  4. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect

    John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

    2002-06-01

    Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

  5. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Fourth quarter 1993 and 1993 summary

    SciTech Connect

    Not Available

    1994-03-01

    The AMB wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) are monitored for selected constituents to comply with the Natural Resources Defense council et al. Consent Decree of May 1988 that identifies the Met Lab HWMF as subject to the Resource Conservation and Recovery Act. In addition, the wells are monitored, as requested, for other constituents as part of the Savannah River Site (SRS) Groundwater Monitoring Program. During the fourth quarter 1993, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded standards during the quarter. As in previous quarters, dichloromethane (methylene chloride), tetrachloroethylene, and trichloroethylene exceeded final Primary Drinking Water Standards; pH, specific conductance, and total organic halogens exceeded the Savannah River Site Flag 2 criteria in one or more of the wells. Groundwater flow direction and rate in the water-table unit were similar to previous quarters.

  6. Sanitary landfill groundwater monitoring report. Fourth quarter 1996 and 1996 summary

    SciTech Connect

    NONE

    1997-02-01

    A maximum of eighty-nine wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Waste Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Dichloromethane, a common laboratory contaminant, and chloroethene (vinyl chloride) were the most widespread constituents exceeding standards during 1996. Benzene, trichloroethylene, 1,4-dichlorobenzene, 1,1-dichloroethylene, lead (total recoverable), gross alpha, mercury (total recoverable), tetrachloroethylene, fluoride, thallium, radium-226, radium-228, and tritium also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 141 ft/year during first quarter 1996 and 132 ft/year during fourth quarter 1996

  7. Biodegradation of chlorinated ethenes by a methane-utilizing mixed culture.

    PubMed Central

    Fogel, M M; Taddeo, A R; Fogel, S

    1986-01-01

    Chlorinated ethenes are toxic substances which are widely distributed groundwater contaminants and are persistent in the subsurface environment. Reports on the biodegradation of these compounds under anaerobic conditions which might occur naturally in groundwater show that these substances degrade very slowly, if at all. Previous attempts to degrade chlorinated ethenes aerobically have produced conflicting results. A mixed culture containing methane-utilizing bacteria was obtained by methane enrichment of a sediment sample. Biodegradation experiments carried out in sealed culture bottles with radioactively labeled trichloroethylene (TCE) showed that approximately half of the radioactive carbon had been converted to 14CO2 and bacterial biomass. In addition to TCE, vinyl chloride and vinylidene chloride could be degraded to products which are not volatile chlorinated substances and are therefore likely to be further degraded to CO2. Two other chlorinated ethenes, cis and trans-1,2-dichloroethylene, were shown to degrade to chlorinated products, which appeared to degrade further. A sixth chlorinated ethene, tetrachloroethylene, was not degraded by the methane-utilizing culture under these conditions. The biodegradation of TCE was inhibited by acetylene, a specific inhibitor of methane oxidation by methanotrophs. This observation supported the hypothesis that a methanotroph is responsible for the observed biodegradations. PMID:3085587

  8. Removal of contaminants in leachate from landfill by waste steel scrap and converter slag.

    PubMed

    Oh, Byung-Taek; Lee, Jai-Young; Yoon, Jeyong

    2007-08-01

    This study may be the first investigation to be performed into the potential benefits of recycling industrial waste in controlling contaminants in leachate. Batch reactors were used to evaluate the efficacy of waste steel scrap and converter slag to treat mixed contaminants using mimic leachate solution. The waste steel scrap was prepared through pre-treatment by an acid-washed step, which retained both zero-valent iron site and iron oxide site. Extensive trichloroethene (TCE) removal (95%) occurred by acid-washed steel scrap within 48 h. In addition, dehalogenation (Cl(-) production) was observed to be above 7.5% of the added TCE on a molar basis for 48 h. The waste steel scrap also removed tetrachloroethylene (PCE) through the dehalogenation process although to a lesser extent than TCE. Heavy metals (Cr, Mn, Cu, Zn, As, Cd, and Pb) were extensively removed by both acid-washed steel scrap and converter slag through the adsorption process. Among salt ions (NH (4)(+) , NO (3)(-) , and PO (4)(3-) ), PO (4)(3-) was removed by both waste steel scrap (100% within 8 h) and converter slag (100% within 20 min), whereas NO (3)(-) and NH (4)(+ ) were removed by waste steel scrap (100% within 7 days) and converter slag (up to 50% within 4 days) respectively. This work suggests that permeable reactive barriers (PRBs) with waste steel scrap and converter slag might be an effective approach to intercepting mixed contaminants in leachate from landfill. PMID:17492478

  9. Analysis of BTEX and chlorinated solvents in meconium by headspace-solid-phase microextraction gas chromatography coupled with mass spectrometry.

    PubMed

    Meyer-Monath, Marie; Beaumont, Jérôme; Morel, Isabelle; Rouget, Florence; Tack, Karine; Lestremau, Francois

    2014-07-01

    Meconium is the earliest stool of newborns, and is a complex matrix that reflects the degree of exposure of the fetus to xenobiotics. To investigate fetal exposure to volatile organic compounds, an analytical method was developed to identify and quantify BTEX (benzene, toluene, ethylbenzene, and o,m,p-xylene) and two chlorinated solvents (trichloroethylene and tetrachloroethylene) in meconium. Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry was selected because it is simple, sensitive, can be automated, and requires no extensive sample preparation. Several extraction variables were optimized (fiber type, incubation time, temperature of fiber, and use of salt). Because meconium is a complex matrix, quantification by SPME was considered carefully because of potential interference, for example competitive adsorption. Calibration in water was compared with calibration in meconium using external and internal methods (with isotope-labeled compounds). In meconium, limits of quantification were determined to be in the range 0.064-0.096 ng g(-1) for the investigated compounds. All target compounds were determined in "real-case" meconium samples. PMID:24838489

  10. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Third quarter, 1994

    SciTech Connect

    Not Available

    1994-12-01

    During third quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Bis(2-ethylhexyl) phthalate exceeded final PDWS in one well. Aluminum, iron, manganese, tin, and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to previous quarters. During second quarter 1994, SRS received South Carolina Department of Health and Environmental Control approval for constructing five point-of-compliance wells and two plume definition wells near the Met Lab HWMF. This project began in July 1994 and is complete; however, analytical data from these wells is not available yet.

  11. Sustainable in-well vapor stripping: A design, analytical model, and pilot study for groundwater remediation.

    PubMed

    Sutton, Patrick T; Ginn, Timothy R

    2014-12-15

    A sustainable in-well vapor stripping system is designed as a cost-effective alternative for remediation of shallow chlorinated solvent groundwater plumes. A solar-powered air compressor is used to inject air bubbles into a monitoring well to strip volatile organic compounds from a liquid to vapor phase while simultaneously inducing groundwater circulation around the well screen. An analytical model of the remediation process is developed to estimate contaminant mass flow and removal rates. The model was calibrated based on a one-day pilot study conducted in an existing monitoring well at a former dry cleaning site. According to the model, induced groundwater circulation at the study site increased the contaminant mass flow rate into the well by approximately two orders of magnitude relative to ambient conditions. Modeled estimates for 5h of pulsed air injection per day at the pilot study site indicated that the average effluent concentrations of dissolved tetrachloroethylene and trichloroethylene can be reduced by over 90% relative to the ambient concentrations. The results indicate that the system could be used cost-effectively as either a single- or multi-well point technology to substantially reduce the mass of dissolved chlorinated solvents in groundwater. PMID:25461885

  12. Research to Support the Determination of Spacecraft Maximum Acceptable Concentrations of Potential Atmospheric Contaminants

    NASA Technical Reports Server (NTRS)

    Orr, John L.

    1997-01-01

    In many ways, the typical approach to the handling of bibliographic material for generating review articles and similar manuscripts has changed little since the use of xerographic reproduction has become widespread. The basic approach is to collect reprints of the relevant material and place it in folders or stacks based on its dominant content. As the amount of information available increases with the passage of time, the viability of this mechanical approach to bibliographic management decreases. The personal computer revolution has changed the way we deal with many familiar tasks. For example, word processing on personal computers has supplanted the typewriter for many applications. Similarly, spreadsheets have not only replaced many routine uses of calculators but have also made possible new applications because the cost of calculation is extremely low. Objective The objective of this research was to use personal computer bibliographic software technology to support the determination of spacecraft maximum acceptable concentration (SMAC) values. Specific Aims The specific aims were to produce draft SMAC documents for hydrogen sulfide and tetrachloroethylene taking maximum advantage of the bibliographic software.

  13. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

    USGS Publications Warehouse

    Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

    2012-01-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

  14. Occurrence of organic wastewater contaminants, pharmaceuticals, and personal care products in selected water supplies, Cape Cod, Massachusetts, June 2004

    USGS Publications Warehouse

    Zimmerman, Marc J.

    2005-01-01

    In June 2004, the U.S. Geological Survey, in cooperation with the Barnstable County Department of Health and Environment, sampled water from 14 wastewater sources and drinking-water supplies on Cape Cod, Massachusetts, for the presence of organic wastewater contaminants, pharmaceuticals, and personal care products. The geographic distribution of sampling locations does not represent the distribution of drinking-water supplies on Cape Cod. The environmental presence of the analyte compounds is mostly unregulated; many of the compounds are suspected of having adverse ecological and human health effects. Of the 85 different organic analyte compounds, 43 were detected, with 13 detected in low concentrations (less than 1 microgram per liter) from drinking-water supplies thought to be affected by wastewater because of previously detected high nitrate concentrations. (Phenol and d-limonene, detected in equipment blanks at unacceptably high concentrations, are not included in counts of detections in this report.) Compounds detected in the drinking-water supplies included the solvent, tetrachloroethylene; the analgesic, acetaminophen; the antibiotic, sulfamethoxazole; and the antidepressant, carbamazapine. Nitrate nitrogen, an indicator of wastewater, was detected in water supplies in concentrations ranging from 0.2 to 8.8 milligrams per liter.

  15. Isolation and properties of a 2-chlorovinylarsonic acid-degrading microorganism.

    PubMed

    Nakamiya, Kunichika; Nakayama, Takashi; Ito, Hiroyasu; Shibata, Yasuyuki; Morita, Masatoshi

    2009-06-15

    2-Chlorovinylarsonic acid (CVAOA) is a stable abiotic metabolite of lewisite 1 that has been identified in lewisite dumps. There have been no reports of microbial degradation of CVAOA, so we isolated and examined CVAOA-degrading microorganisms. CVAOA contains arsine, which is toxic to microbial growth. We therefore used the simple organic chemical, ethylene, as a sole carbon source in initial screening for suitable microbes. We isolated several microorganisms from sewage sludge and soil. Two strains, NK0505 and NK0506, could be grown on CVAOA as the sole carbon source and were identified by 16S rRNA sequencing as Nocardia carnea NK0505 and Rhodococcus opacus NK0506. Because N. carnea NK0505 was slightly more active in degrading CVAOA, we used it for further degradation studies. Strain NK0505 utilized about 90% of CVAOA (50 ppm) within 5 days; at higher concentrations of CVAOA no degradation occurred over a 10-day period. We identified 1-chloro-1,2-dihydroxyethane, ethylene glycol, glycolic acid, and arsenic acid as degradation products of CVAOA. Epoxy formation on alkylarsine was not confirmed. CVAOA is probably further metabolized via these compounds in the tricarboxylic acid cycle. Strain NK0505 could also degrade but-3-enylarsonic acid, trichloroethylene, isoprene, and 1,3-butadiene, but utilization of tetrachloroethylene and acetylene did not occur. PMID:19022568

  16. Preliminary Engineering Report contaminated groundwater seeps 317/319/ENE area

    SciTech Connect

    NONE

    1996-10-01

    When the Resource Conservation and Recovery Act Facility Investigation (RFI) in the 317/319/ENE Area of Argonne National Laboratory-East (ANL-E) was being completed, groundwater was discovered moving to the surface through a series of seeps. The seeps are located approximately 600 ft south of the ANL fence line in Waterfall Glen Forest Preserve. Samples of this water were collected and analyzed for selected parameters. Two of five seeps sampled were found to contain detectable levels of organic contaminants. Three chemical species were identified: chloroform (14-25 {mu}g/L), carbon tetrachloride (56-340 {mu}g/L), and tetrachloroethylene (3-6 {mu}g/L). The other seeps did not contain detectable levels of volatile organic compounds (VOCs). The water issuing from these two contaminated seeps flows into a narrow ravine, where it is visible as a trickle of water flowing through sand and gravel deposits on the floor of the ravine. Approximately 100-ft downstream of the seep area, the contaminated water is no longer visible, having drained back into the soil in the bed of the ravine. Figure 1 shows the location of the 317/319/ENE Area in relation to the ANL-E site and the Waterfall Glen Forest Preserve.

  17. Vapor-phase exchange of perchloroethene between soil and plants

    USGS Publications Warehouse

    Struckhoff, G.C.; Burken, J.G.; Schumacher, J.G.

    2005-01-01

    Tree core concentrations of tetrachloroethylene (perchloroethene, PCE) at the Riverfront Superfund Site in New Haven, MO, were found to mimic the profile of soil phase concentrations. The observed soil-tree core relationship was stronger than that of groundwater PCE to tree core concentrations at the same site. Earlier research has shown a direct, linear relationship between tree core and groundwater concentrations of chlorinated solvents and other organics. Laboratory-scale experiments were performed to elucidate this phenomenon, including determining partitioning coefficients of PCE between plant tissues and air and between plant tissues and water, measured to be 8.1 and 49 L/kg, respectively. The direct relationship of soil to tree core PCE concentrations was hypothesized to be caused by diffusion between tree roots and the soil vapor phase in the subsurface. The central findings of this research are discovering the importance of subsurface vapor-phase transfer for VOCs and uncovering a direct relationship between soil vapor-phase chlorinated solvents and uptake rates that impact contaminant translocation from the subsurface and transfer into the atmosphere. ?? 2005 American Chemical Society.

  18. Evaluation of the atmosphere as a source of volatile organic compounds in shallow groundwater

    NASA Astrophysics Data System (ADS)

    Baehr, Arthur L.; Stackelberg, Paul E.; Baker, Ronald J.

    1999-01-01

    The atmosphere as a source of volatile organic compounds (VOCs) in shallow groundwater was evaluated over an area in southern New Jersey. Chloroform, methyl tertbutyl ether (MTBE), 1,1,1-trichloroethane, tetrachloroethylene (PCE), and carbon disulfide (not a VOC) were detected frequently at low-level concentrations in a network of 78 shallow wells in the surficial Kirkwood-Cohansey aquifer system. The atmosphere was sampled for these compounds and only MTBE concentrations were high enough to potentially explain frequent detection in shallow groundwater. A mathematical model of reactive transport through the unsaturated zone is presented to explain how variations in unsaturated properties across the study area could explain differences in MTBE concentrations in shallow groundwater given the atmosphere as the source. Even when concentrations of VOCs in groundwater are low compared to regulatory concentration limits, it is critical to know the source. If the VOCs originate from a point source((), concentrations in groundwater could potentially increase over time to levels of concern as groundwater plumes evolve, whereas if the atmosphere is the source, then groundwater concentrations would be expected to remain at low-level concentrations not exceeding those in equilibrium with atmospheric concentrations. This is the first analysis of VOC occurrence in shallow groundwater involving colocated atmosphere data.

  19. Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

    NASA Astrophysics Data System (ADS)

    Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

    2012-05-01

    In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

  20. A procedure to design a Permeable Adsorptive Barrier (PAB) for contaminated groundwater remediation.

    PubMed

    Erto, A; Lancia, A; Bortone, I; Di Nardo, A; Di Natale, M; Musmarra, D

    2011-01-01

    A procedure to optimize the design of a Permeable Adsorptive Barrier (PAB) for the remediation of a contaminated aquifer is presented in this paper. A computer code, including different routines that describe the groundwater contaminant transport and the pollutant capture by adsorption in unsteady conditions over the barrier solid surface, has been developed. The complete characterization of the chemical-physical interactions between adsorbing solids and the contaminated water, required by the computer code, has been obtained by experimental measurements. A case study in which the procedure developed has been applied to a tetrachloroethylene (PCE)-contaminated aquifer near a solid waste landfill, in the district of Napoli (Italy), is also presented and the main dimensions of the barrier (length and width) have been evaluated. Model results show that PAB is effective for the remediation of a PCE-contaminated aquifer, since the concentration of PCE flowing out of the barrier is everywhere always lower than the concentration limit provided for in the Italian regulations on groundwater quality. PMID:20846781

  1. Permeable Adsorptive Barrier (PAB) for the remediation of groundwater simultaneously contaminated by some chlorinated organic compounds.

    PubMed

    Erto, A; Bortone, I; Di Nardo, A; Di Natale, M; Musmarra, D

    2014-07-01

    In this paper, a Permeable Reactive Barrier (PRB) made with activated carbon, namely a Permeable Adsorptive Barrier (PAB), is put forward as an effective technique for the remediation of aquifers simultaneously contaminated by some chlorinated organic compounds. A design procedure, based on a computer code and including different routines, is presented as a tool to accurately describe mass transport within the aquifer and adsorption/desorption phenomena occurring inside the barrier. The remediation of a contaminated aquifer near a solid waste landfill in the district of Napoli (Italy), where Tetrachloroethylene (PCE) and Trichloroethylene (TCE) are simultaneously present, is considered as a case study. A complete hydrological and geotechnical site characterization, as well as a number of dedicated adsorption laboratory tests for the determination of activated carbon PCE/TCE adsorption capacity in binary systems, are carried out to support the barrier design. By means of a series of numerical simulations it is possible to determine the optimal barrier location, orientation and dimensions. PABs appear to be an effective remediation tool for the in-situ treatment of an aquifer contaminated by PCE and TCE simultaneously, as the concentration of both compounds flowing out of the barrier is everywhere lower than the regulatory limits on groundwater quality. PMID:24747934

  2. Anionic surfactant remediation of soil columns contaminated by nonaqueous phase liquids

    NASA Astrophysics Data System (ADS)

    Dwarakanath, V.; Kostarelos, K.; Pope, Gary A.; Shotts, Doug; Wade, William H.

    1999-06-01

    A variety of column experiments have been completed for the purpose of selecting and evaluating suitable surfactants for remediation of nonaqueous phase liquids (NAPLs). The various NAPLs tested in the laboratory experiments were tetrachloroethylene (PCE), trichloroethylene (TCE), jet fuel (JP4) and a dense nonaqueous phase liquid from a site at Hill Air Force Base, UT. Both Ottawa sand and Hill field soil were used in these experiments. Surfactant candidates were first screened using phase behavior experiments and only the best ones were selected for the subsequent column experiments. Surfactants which showed high contaminant solubilization, fast coalescence times, and the absence of liquid crystal phases and gels during the phase behavior experiments were tested in soil column experiments. The primary objective of the soil column experiments was to identify surfactants that recovered at least 99% of the contaminant. The secondary objective was to identify surfactants that show low adsorption and little or no loss of hydraulic conductivity during the column experiments. Results demonstrated that up to 99.9% of the contaminants were removed as a result of surfactant flooding of the soil columns. The addition of xanthan gum polymer to the surfactant solution was shown to increase remediation efficiency as a lower volume of surfactant was required for recovering a given volume of NAPL. Based on these experimental results, guidelines for designing highly efficient and robust surfactant floods have been developed and applied to a field demonstration.

  3. Photochemical pollution at two southern California smog receptor sites

    SciTech Connect

    Grosjean, D.; Williams, E.L. II. (DGA, Inc., Ventura, CA (United States))

    1992-06-01

    A one-year survey of air quality has been carried out at two southern California inland locations, Perris and Palm Springs to evaluate transport of photochemical smog from the Los Angeles area and to assess population exposure to toxic air pollutants in the Coachella Valley and eastern Riverside County. Air pollutants measured included formaldehyde, acetaldehyde, nitric acid, and peroxyacetyl nitrate (PAN). Acetic acid was also measured as part of the time-integrated method employed to measure PAN. In addition, intensive studies were carried out at both locations and included measurements of aldehydes, nitric acid, PAN, peroxypropionyl nitrate (PPN), methylchloroform and tetrachloroethylene. Maximum concentrations of HCHO, CH{sub 3}CHO, HNO{sub 3}, PAN, PPN, CH{sub 3}COOH and C{sub 2}Cl{sub 4} were 26, 21, 4.5, 7.6, 0.42, 6.6 and 0.29 ppb in Palm Springs and 15, 30, 6.3, 9.1, 0.73, 7.8 and 0.43 ppb in Perris. Pollutant concentrations measured in Palm Springs and Perris are compared to those measured in the Los Angeles area, and are discussed in terms of formation and removal during transport.

  4. Analysis of nitrate and volatile organic compound data for ground water in the Great Salt Lake Basins, Utah, Idaho, and Wyoming, 1980-98, National Water-Quality Assessment Program

    USGS Publications Warehouse

    Thiros, Susan A.

    2000-01-01

    In 1995, ground water was the source of drinking water to about 52 percent of the population served by public drinking water systems in the Great Salt Lake Basins study unit, which includes parts of Utah, Idaho, and Wyoming. Existing nitrate and volatile organic compound data for ground water collected in the study unit were compiled and summarized as part of the National Water-Quality Assessment Program?s objective to describe water-quality conditions in the Nation?s aquifers. Prerequisites for the inclusion of nitrate and volatile organic compound data into this retrospective analysis are that the data set is available in electronic form, the data were collected during 1980-98, the data set is somewhat regional in coverage, and the locations of the sampled sites are known. Ground-water data stored in the U.S. Geological Survey?s National Water Information Systemand the Idaho and Utah Public DrinkingWater Systems databases were reviewed. Only the most recent analysis was included in the data sets if more than one analysis was available for a site. The National Water Information System data set contained nitrate analyses for water from 480 wells. The median concentration of nitratewas 1.30 milligrams per liter for the 388 values above minimum reporting limits. The maximum contaminant level for nitrate as established by the U.S. Environmental Protection Agency was exceeded in water from 10 of the 200 wells less than or equal to 150 feet deep and in water from3 of 280 wells greater than 150 feet deep. The Public Drinking Water Systems data set contained nitrate analyses for water from 587 wells. The median concentration of nitrate was 1.12 milligrams per liter for the 548 values above minimum reporting limits. The maximum contaminant level for nitrate was exceeded at 1 site and 22 sites had concentrations equal to or greater than 5 milligrams per liter. The types of land use surrounding a well and the well depth were related to measured nitrate concentrations in the sampled ground water. Overall, water sampled from wells in rangeland areas had a lowermedianmeasured nitrate concentration (0.76 milligrams per liter) than water from areas with an agricultural or urban/residential land use (1.41 and 1.20 milligrams per liter, respectively). In the NationalWater Information System data set, the median measured nitrate concentration in water from urban/residential areas varied from 1.00 milligrams per liter for wells greater than 150 feet deep to 1.84 milligrams per liter for wells less than or equal to 150 feet deep. The Public DrinkingWater Systems and the National Water Information System data sets contained analyses for most of the State and Federally regulated volatile organic compounds in water from about 368 and 74 wells, respectively. Fifteen different volatile organic compounds were detected at least once in ground water sampled from the Great Salt Lake Basins study unit. Water from 21 wells contained at least 1 volatile organiccompound at detectable concentrations. About 68 percent of the volatile organic compounds detected were in water sampled from wells in Salt Lake County, Utah. Tetrachloroethylene was the most commonly detected volatile organic compound in ground water sampled from the study unit, present in 8 out of 442 samples. Maximum contaminant levels for tetrachloroethylene and 1,1-dichloroethylene as established by the U.S. Environmental Protection Agency were exceeded in water from one well each.

  5. Measurements of chlorinated volatile organic compounds emitted from office printers and photocopiers.

    PubMed

    Kowalska, Joanna; Szewczy?ska, Ma?gorzata; Po?niak, Ma?gorzata

    2015-04-01

    Office devices can release volatile organic compounds (VOCs) partly generated by toners and inks, as well as particles of paper. The aim of the presented study is to identify indoor emissions of volatile halogenated organic compounds into the office workspace environment. Mixtures of organic pollutants emitted by seven office devices, i.e. printers and copiers, were analyzed by taking samples in laboratory conditions during the operation of these appliances. Tests of volatile organic compound emissions from selected office devices were conducted in a simulated environment (test chamber). Samples of VOCs were collected using three-layered thermal desorption tubes. Separation and identification of organic pollutant emissions were made using thermal desorption combined with gas chromatography coupled to mass spectrometry. Test chamber studies indicated that operation of the office printer and copier would contribute to the significant concentration level of VOCs in typical office indoor air. Among the determined volatile halogenated compounds, only chlorinated organic compounds were identified, inter alia: trichloroethylene - carcinogenic - and tetrachloroethylene - possibly carcinogenic to human. The results show that daily exposure of an office worker to chemical factors released by the tested printing and copying units can be variable in terms of concentrations of VOCs. The highest emissions in the test chamber during printing were measured for ethylbenzene up to 41.3 ?g m(-3), xylenes up to 40.5 ?g m(-3) and in case of halogenated compounds the highest concentration for chlorobenzene was 6.48 ?g m(-3). The study included the comparison of chamber concentrations and unit-specific emission rates of selected VOCs and the identified halogenated compounds. The highest amount of total VOCs was emitted while copying with device D and was rated above 1235 ?g m(-3) and 8400 ?g unit(-1) h(-1) on average. PMID:25323406

  6. Hydrogeologic Setting of A/M Area: Framework for Groundwater Transport. Book 1

    SciTech Connect

    Van Pelt, R.; Lewis, S.E.; Aadland, R.K.

    1994-03-11

    This document includes a brief summary of the regional geology within a 200--mile radius of the A/M Area, a summary of stratigraphy and hydrostratigraphic nomenclature as it applies to the A/M Area, and a summary of stratigraphy and hydrostratigraphy specific to the A/M Area. Five different stratigraphic cross sections show site-specific geology of the Tertiary section of the Upper Atlantic Coastal Plain geologic province within the A/M Area. The Cretaceous section lacks detail because the deepest wells penetrate only the uppermost part of the Upper Cretaceous sediments. Most of the wells are confined to the Tertiary section. The A/M Area is located in the northwestern corner of the Savannah River Site (SRS). The area serves as a main administrative hub for the site. Between 1958 and 1985, approximately 2,000,000 pounds of volatile organic solvents (metal degreasers, primarily trichloroethylene and tetrachloroethylene) were routed to the M Area Settling Basin. Between 1954 and 1958, effluent also was discharged to Tim`s Branch via the A014 Outfall. In the main M Area Solvent Handling/Storage Area, a significant amount of leakage occurred from drums stored during this time period. Extensive quantities of solvents were transported, via the Process Sewer Line, to the M Area Settling Basin, and leaks occurred along this line as well. A smaller source area has been identified and is centered around the Savannah River Laboratory (SRL) (now called the Savannah River Technology Center [SRTC]) Complex. All of these source areas are represented by solvent contamination in the groundwater system. (Abstract Truncated)

  7. Evaluating Dense Non-Aqueous Phase Liquid Dissolution and Chemical Oxidation in a three-dimensional, bench-scale fracture network

    NASA Astrophysics Data System (ADS)

    Christensen, K.; McCray, J. E.; Schaefer, C.

    2011-12-01

    Dense non-aqueous phase liquid (DNAPL) present in fractured bedrock settings at residual saturation introduces remediation challenges that are dramatically different from porous media settings. Evaluating DNAPL distribution in a field-scale setting is generally impractical, yet DNAPL distribution plays a critical role in the DNAPL dissolution kinetics. This research uses a three-dimensional (3-D), bench-scale network comprised of low-porosity, fractured sandstone to evaluate the dissolution kinetics of tetrachloroethylene (PCE) DNAPL at residual saturation. DNAPL dissolution kinetics were evaluated during ambient groundwater conditions as well as during in situ chemical oxidation (ISCO) in the 3-D fractured sandstone experiment. DNAPL dissolution in the fracture network was evaluated and described using an effective parameter, the bulk mass transfer coefficient (KL). Results from dissolution experiments revealed a positive, statistically significant correlation between KL with DNAPL-water interfacial area and KL with DNAPL saturation. Results of ISCO experiments with potassium permanganate (KMnO4) determined that the formation of reaction products (manganese dioxides and carbon dioxide) likely altered the primary flow paths and decreased effectiveness of the ISCO application in the fracture network. The formation of reaction products was believed to cause flow bypassing and reduce the DNAPL-oxidant contact, which reduced mass transfer rates. The effectiveness of ISCO was improved (over dissolution alone) if the ISCO application was discontinued after an initial period of effective mass removal. The findings of this research indicate that DNAPL dissolution and oxidation effectiveness in a fracture network setting are not directly correlated to aperture size, which was unexpected, but appear to be primarily impacted by flow path variability and heterogeneous DNAPL distribution.

  8. Determinants of personal, indoor and outdoor VOC concentrations: an analysis of the RIOPA data.

    PubMed

    Su, Feng-Chiao; Mukherjee, Bhramar; Batterman, Stuart

    2013-10-01

    Community and environmental exposure to volatile organic compounds (VOCs) has been associated with a number of emission sources and activities, e.g., environmental tobacco smoke and pumping gasoline. Such factors have been identified from mostly small studies with relatively limited information regarding influences on VOC levels. This study uses data from the Relationship of Indoor Outdoor and Personal Air (RIOPA) study to investigate environmental, individual and social determinants of VOC concentrations. RIOPA included outdoor, indoor and personal measurements of 18 VOCs from 310 non-smoking households and adults in three cities and two seasons, and collected a wide range of information pertaining to participants, family members, households, and neighborhoods. Exposure determinants were identified using stepwise regressions and linear mixed-effect models. Most VOC exposure (66 to 78% of the total exposure, depending on VOC) occurred indoors, and outdoor VOC sources accounted for 5 (d-limonene) to 81% (carbon tetrachloride) of the total exposure. Personal exposure and indoor measurements had similar determinants, which depended on the VOC. Gasoline-related VOCs (e.g., benzene, methyl tertiary butyl ether) were associated with city, residences with attached garages, self-pumping of gas, wind speed, and house air exchange rate (AER). Odorant and cleaning-related VOCs (e.g., 1,4-dichlorobenzene and chloroform) also were associated with city and AER, and with house size and family members showering. Dry-cleaning and industry-related VOCs (e.g., tetrachloroethylene and trichloroethylene) were associated with city, residence water supply type, and dry-cleaner visits. These and other relationships were significant, explained from 10 to 40% of the variation, and are consistent with known emission sources and the literature. Outdoor concentrations had only two common determinants: city and wind speed. Overall, personal exposure was dominated by the home setting, although a large fraction of VOC concentrations were due to outdoor sources. City, personal activities, household characteristics and meteorology were significant determinants. PMID:24034784

  9. Abiotic reductive dechlorination of chlorinated ethylenes by iron-bearing phyllosilicates.

    PubMed

    Lee, Woojin; Batchelor, Bill

    2004-09-01

    Abiotic reductive dechlorination of chlorinated ethylenes (tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (c-DCE), and vinylchloride (VC)) by iron-bearing phyllosilicates (biotite, vermiculite, and montmorillonite) was characterized to obtain better understanding of the behavior of these contaminants in systems undergoing remediation by natural attenuation and redox manipulation. Batch experiments were conducted to evaluate dechlorination kinetics and some experiments were conducted with addition of Fe(II) to simulate impact of microbial iron reduction. A modified Langmuir-Hinshelwood kinetic model adequately described reductive dechlorination kinetics of target organics by the iron-bearing phyllosilicates. The rate constants stayed between 0.08 (+/-10.4%) and 0.401 (+/-8.1%) day(-1) and the specific initial reductive capacity of iron-bearing phyllosilicates for chlorinated ethylenes stayed between 0.177 (+/-6.1%) and 1.06 (+/-7.1%) microM g(-1). The rate constants for the reductive dechlorination of TCE at reactive biotite surface increased as pH (5.5-8.5) and concentration of sorbed Fe(II) (0-0.15 mM g(-1)) increased. The appropriateness of the model is supported by the fact that the rate constants were independent of solid concentration (0.0085-0.17 g g(-1)) and initial TCE concentration (0.15-0.60 mM). Biotite had the greatest rate constant among the phyllosilicates both with and without Fe(II) addition. The rate constants were increased by a factor of 1.4-2.5 by Fe(II) addition. Between 1.8% and 36% of chlorinated ethylenes removed were partitioned to the phyllosilicates. Chloride was produced as a product of degradation and no chlorinated intermediates were observed throughout the experiment. PMID:15268967

  10. Reductive capacity of natural reductants.

    PubMed

    Lee, Woojin; Batchelor, Bill

    2003-02-01

    Reductive capacities of soil minerals and soil for Cr(VI) and chlorinated ethylenes were measured and characterized to provide basic knowledge for in-situ and ex-situ treatment using these natural reductants. The reductive capacities of iron-bearing sulfide (pyrite), hydroxide (green rust; GR(SO4)), and oxide (magnetite) minerals for Cr(VI) and tetrachloroethylene (PCE) were 1-3 orders of magnitude greater than those of iron-bearing phyllosilicates (biotite, vermiculite, and montmorillonite). The reductive capacities of surface soil collected from the plains of central Texas were similar and slightly greater than those of iron-bearing phyllosilicates. The reductive capacity of iron-bearing soil minerals for Cr(VI) was roughly 3-16 times greater than that for PCE, implying that Cr(VI) is more susceptible to being reduced by soil minerals than is PCE. GR(SO4) has the greatest reductive capacity for both Cr(VI) and PCE followed by magnetite, pyrite, biotite, montmorillonite, and vermiculite. This order was the same for both target compounds, which indicates that the relative reductive capacities of soil minerals are consistent. The reductive capacities of pyrite and GR(SO4) for chlorinated ethylenes decreased in the order: trichloroethylene (TCE) > PCE > cis-dichloroethylene (c-DCE) > vinyl chloride (VC). Fe(II) content in soil minerals was directly proportional to the reductive capacity of soil minerals for Cr(VI) and PCE, suggesting that Fe(II) content is an important factor that significantly affects reductive transformations of target contaminants in natural systems. PMID:12630469

  11. Limited representation of drinking-water contaminants in pregnancy-birth cohorts.

    PubMed

    Makris, Konstantinos C; Andra, Syam S

    2014-01-15

    Water contamination and noise have been consistently the least assessed environmental/lifestyle exposures in pregnancy-birth cohorts (PBC). Water quality surveillance data collected during the past decade within urban drinking-water distribution systems call for re-evaluation of water and health issues in the developed world. The objectives of this scientific commentary were to (i) highlight the extent of appraisal of water contamination in exposure assessment studies of PBC, worldwide, and (ii) propose recommendations to increase awareness of emerging water-related risks through their improved representation into PBC study designs in urban centers. Three scientific literature databases (Scopus, PubMed, and Web of Science) were used for a systematic search on worldwide PBC and their publications that considered water contamination and health outcomes. Publicly-available e-databases (ENRIECO, BIRTHCOHORTS, and CHICOS) were also employed for detailed exploration of existing European Union (EU)-based PBC. Out of the 76 PBC identified in the EU territory, only 12 of them incorporated water contamination into their study designs. Among which only 6 PBC published scientific articles that either included data on water contamination and/or water intake estimates. Trihalomethanes but not other disinfection by-products were mostly studied in the PBC around the globe, while fluoride, atrazine, perfluorinated compounds, tetrachloroethylene, and lead were studied to a lesser extent as water contaminants. It appears that chemical-based water contamination and corresponding human exposures represent a largely underappreciated niche of exposure science pertaining to pregnant mother and children's health in PBC. Future PBC studies should grasp this opportunity to substantially reform elements of water contamination in their exposure assessment protocols and effectively combine them with their epidemiological study designs. PMID:24013514

  12. VOCs in Non-Arid Soils Integrated Demonstration: Technology summary

    SciTech Connect

    Not Available

    1994-02-01

    The Volatile Organic Compounds (VOCs) in Non-Arid Soils Integrated Demonstration (ID) was initiated in 1989. Objectives for the ID were to test the integrated demonstration concept, demonstrate and evaluate innovative technologies/systems for the remediation of VOC contamination in soils and groundwater, and to transfer technologies and systems to internal and external customers for use in fullscale remediation programs. The demonstration brought together technologies from DOE laboratories, other government agencies, and industry for demonstration at a single test bed. The Savannah River Site was chosen as the location for this ID as the result of having soil and groundwater contaminated with VOCS. The primary contaminants, trichlorethylene and tetrachloroethylene, originated from an underground process sewer line servicing a metal fabrication facility at the M-Area. Some of the major technical accomplishments for the ID include the successful demonstration of the following: In situ air stripping coupled with horizontal wells to remediate sites through air injection and vacuum extraction; Crosshole geophysical tomography for mapping moisture content and lithologic properties of the contaminated media; In situ radio frequency and ohmic heating to increase mobility, of the contaminants, thereby speeding recovery and the remedial process; High-energy corona destruction of VOCs in the off-gas of vapor recovery wells; Application of a Brayton cycle heat pump to regenerate carbon adsorption media used to trap VOCs from the offgas of recovery wells; In situ permeable flow sensors and the colloidal borescope to determine groundwater flow; Chemical sensors to rapidly quantify chlorinated solvent contamination in the subsurface; In situ bioremediation through methane/nutrient injection to enhance degradation of contaminants by methanotrophic bateria.

  13. Reproductive risks from contaminants in drinking water.

    PubMed

    Mantovani, A

    1993-01-01

    Reproductive toxicity is a complex subject which, besides birth defects or sterility, includes adverse effects which may be less readily observed but more relevant to chronic low-level exposures (e.g., impaired functional development of target organs or systems, secretion of toxic chemicals in maternal milk). Sodium chlorite, when present at high concentration, may be related to impaired reproduction; among water chlorination by-products, further research is required on the developmental toxicity of chloroacetic acid and dichloro- and trichloro acetonitrile. Among the water pollutants which may pose significant developmental hazards, risk assessments have been performed for nitrates/nitrites, fluorides and lead. Molinate (a herbicide), dibromochloropropane (a nematocide) and the halogenated contaminants ethylene dibromide and epichlorohydrin show an almost selective male reproductive toxicity, although they are likely to pose a risk mainly at occupational exposure conditions. Ethylene thiourea, an environmental metabolite of some fungicides is markedly teratogenic in the rat: however, other toxic effects are induced at levels of exposure significantly lower than the teratogenic ones. Such poorly water-soluble compounds as TCDD or hexachlorobenzene also need to be considered, because of their remarkable potentials for reproductive toxicity. Finally, it should be noted that the data on reproductive toxicity for a number of chemicals do not allow a risk assessment at present: this holds true also for some substances which might pose concerns on the basis of their levels in drinking water (e.g. tetrachloroethylene, nickel). Another area which deserves more attention is the investigation of the possible interactions of several contaminants present together at low levels. PMID:8279723

  14. Distributions and sea-to-air fluxes of volatile halocarbons in the East China Sea in early winter.

    PubMed

    He, Zhen; Yang, Gui-Peng; Lu, Xiao-Lan

    2013-01-01

    The concentrations of six volatile halogenated organic compounds (VHOC)-chloroform (CHCl(3)), trichloroethylene (C(2)HCl(3)), tetrachloroethylene (C(2)Cl(4)), carbon tetrachloride (CCl(4)), methylchloroform (CH(3)CCl(3)), and bromoform (CHBr(3)) in the East China Sea (ECS) in November and December 2010 were measured by a purge and trap system coupled to a gas chromatograph with an electron capture detection (ECD). Mean (range) concentrations of CHCl(3), C(2)HCl(3), C(2)Cl(4), CH(3)CCl(3), CCl(4) and CHBr(3) in the surface water were 16.90 (0.40-62.92), 16.27 (2.78-83.33), 2.40 (0.39-9.33), 32.29 (19.72-57.68), 1.70 (0.39-8.73) and 17.11 (4.33-34.46) pM, respectively. With the exception of C(2)HCl(3), the concentrations of other five kinds of VHOC generally exhibited a decreasing trend with distance from the coast, with the low values found in the open sea. The anthropogenic sources contributed to the elevated levels of CCl(4) and CH(3)CCl(3), whereas a combination of the anthropogenic and biogenic sources might be responsible for the elevated levels of CHCl(3), C(2)HCl(3), C(2)Cl(4) and CHBr(3). In the depth profiles, vertical distributions of the six VHOC in the water column were complicated, with the maxima occurring at 0-100 m depths. The mean sea-to-air fluxes of CHCl(3), C(2)HCl(3), C(2)Cl(4) and CHBr(3) were estimated to be 21.08, 29.94, 2.05 and 35.50 nmol m(-2) d(-1), respectively, indicating that the ECS was a source for the four VHOC in the atmosphere. PMID:23102696

  15. Determination of volatile organic compounds in water by headspace solid-phase microextraction gas chromatography coupled to tandem mass spectrometry with triple quadrupole analyzer.

    PubMed

    Cervera, M I; Beltran, J; Lopez, F J; Hernandez, F

    2011-10-17

    In the present work, a rapid method with little sample handling has been developed for determination of 23 selected volatile organic compounds in environmental and wastewater samples. The method is based on headspace solid-phase microextraction (SPME) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) determination using triple quadrupole analyzer (QqQ) in electron ionization mode. The best conditions for extraction were optimised with a factorial design taking into account the interaction between different parameters and not only individual effects of variables. In the optimized procedure, 4 mL of water sample were extracted using a 10 mL vial and adding 0.4 g NaCl (final NaCl content of 10%). An SPME extraction with carboxen/polydimethylsiloxane 75 ?m fiber for 30 min at 50°C (with 5 min of previous equilibration time) with magnetic stirring was applied. Chromatographic determination was carried out by GC-MS/MS working in Selected Reaction Monitoring (SRM) mode. For most analytes, two MS/MS transitions were acquired, although for a few compounds it was difficult to obtain characteristic abundant fragments. In those cases, a pseudo selected reaction monitoring (pseudo-SRM) with three ions was used instead. The intensity ratio between quantitation (Q) and confirmation (q) signals was used as a confirmatory parameter. The method was validated by means of recovery experiments (n=6) spiking mineral water samples at three concentration levels (0.1, 5 and 50 ?g L(-1)). Recoveries between 70% and 120% were generally obtained with relative standard deviations (RSDs) lower than 20%. The developed method was applied to surface water and wastewater from a wastewater treatment plant and from a municipal solid-waste treatment plant. Several compounds, like chloroform, benzene, trichloroethylene, toluene, tetrachloroethylene, dibromochloromethane, xylenes and bromoform were detected and confirmed in all the samples analyzed. PMID:21907025

  16. Valiant 'Zero-Valent' Effort Restores Contaminated Grounds

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Dense non-aqueous phase liquids (DNAPLs) are chemical compounds that can contaminate soil and groundwater to the point of irreparability. These substances are only slightly soluble in water, and are much denser than water. Because of their solubility, DNAPLs form separate liquid phases in groundwater, and because of their density, DNAPLs sink in aquifers instead of floating at the water table, making it extremely difficult to detect their presence. If left untreated in the ground, they can taint fresh water sources. Common DNAPLs include chlorinated hydrocarbon compounds such as carbon tetrachloride, chloroform, tetrachloroethylene, and trichloroethylene. Trichloroethylene was used during the early days of the Space Program, as a solvent for flushing rocket engines, and for metal cleaning and degreasing of equipment, electronics, and heavy machinery. As a result, areas of Cape Canaveral s Launch Complex 34, the site of several historic Saturn rocket launches occurring from 1959 to 1968, were polluted with chlorinated DNAPLs. Through the direction and guidance of Dr. Jacqueline Quinn, an environmental engineer in the Spaceport Engineering and Technology Directorate at NASA s Kennedy Space Center, a biodegradable environmental cleanup technology was developed to reductively dechlorinate DNAPL sources in polluted water at Launch Complex 34. It was important for Kennedy to nip this problem in the bud, in light of the fact that the Space Center is also a National Wildlife Refuge, home to thousands of shorebirds, endangered sea turtles and eagles, manatees, alligators, and diverse habitats that include brackish marshes and salt water estuaries. The success in remediating this historic launch site has led to numerous commercial applications that are restoring the health of our environmental surroundings.

  17. Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

    SciTech Connect

    Elmore, B.B.

    1993-08-01

    As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

  18. CROWTM PROCESS APPLICATION FOR SITES CONTAMINATED WITH LIGHT NON-AQUEOUS PHASE LIQUIDS AND CHLORINATED HYDROCARBONS

    SciTech Connect

    L.A. Johnson, Jr.

    2003-06-30

    Western Research Institute (WRI) has successfully applied the CROWTM (Contained Recovery of Oily Wastes) process at two former manufactured gas plants (MGPs), and a large wood treatment site. The three CROW process applications have all occurred at sites contaminated with coal tars or fuel oil and pentachlorophenol (PCP) mixtures, which are generally denser than water and are classified as dense non-aqueous phase liquids (DNAPLs). While these types of sites are abundant, there are also many sites contaminated with gasoline, diesel fuel, or fuel oil, which are lighter than water and lie on top of an aquifer. A third site type occurs where chlorinated hydrocarbons have contaminated the aquifer. Unlike the DNAPLs found at MGP and wood treatment sites, chlorinated hydrocarbons are approximately one and a half times more dense than water and have fairly low viscosities. These contaminants tend to accumulate very rapidly at the bottom of an aquifer. Trichloroethylene (TCE) and perchloroethylene, or tetrachloroethylene (PCE), are the major industrial chlorinated solvents that have been found contaminating soils and aquifers. The objective of this program was to demonstrate the effectiveness of applying the CROW process to sites contaminated with light non-aqueous phase liquids (LNAPLs) and chlorinated hydrocarbons. Individual objectives were to determine a range of operating conditions necessary to optimize LNAPL and chlorinated hydrocarbon recovery, to conduct numerical simulations to match the laboratory experiments and determine field-scale recoveries, and determine if chemical addition will increase the process efficiency for LNAPLs. The testing consisted of twelve TCE tests; eight tests with PCE, diesel, and wood treatment waste; and four tests with a fuel oil-diesel blend. Testing was conducted with both vertical and horizontal orientations and with ambient to 211 F (99 C) water or steam. Residual saturations for the horizontal tests ranged from 23.6% PV to 0.3% PV. Also conducted was screening of 13 chemicals to determine their relative effectiveness and the selection of three chemicals for further testing.

  19. Piezo-resistivity electric cone penetration technology investigation of the M-basin at the Savannah River Site, Aiken, South Carolina. Progress report, May 1, 1992--October 31, 1992

    SciTech Connect

    Bowers, B. [Westinghouse Savannah River Co., Aiken, SC (United States); Rossabi, J.; Shinn, J.D. II; Bratton, W.L. [Applied Research Associates, Inc., South Royalton, VT (United States)

    1997-05-01

    This report documents the results of a combined field and laboratory investigation program to: (1) delineate the geologic layering and (2) determine the location of a dense non-aqueous liquid-phase (DNAPL) contaminated plume beneath the M Area Hazardous Waste Management Facility at the Savannah River Plant. During April of 1991, DNAPLs were detected in monitoring well (MSB-3D), located adjacent to the capped M-Area Settling Basin. Solvents in the well consisted mainly of tetrachloroethylene and trichloroethylene, which are also the main solvents found in groundwater in the M Area. In permeable soils, DNAPLs move downward rapidly due to their high density and low viscosity as compared to water. Within the vadose zone, DNAPLs tend to be held by the less permeable clay and silts by capillary force. In the saturated zone, the downward movement is slowed by clays and silts and the DNAPL tends to pool on this layer, then spread laterally. The lateral movement continues until a permeable layer is encountered, which can be a sand lens, fracture or other high conductivity seam. The DNAPL then moves downward, until another low permeability layer is encountered. Applied Research Associates was contracted to conduct a program to: (1) field demonstrate the utility of Cone Penetration Technology to investigate DOE contaminant sites and, (2) conduct a laboratory and field program to evaluate the use of electric resistivity surveys to locate DNAPL contaminated soils. The field program was conducted in the M-Basin and laboratory tests were conducted on samples from the major stratigraphy units as identified in Eddy et. al. Cone Penetration Technology was selected to investigate the M-Basin as it: (1) is minimally invasive, (2) generates minimal waste, (3) is faster and less costly than drilling, (4) provides continuous, detailed in situ characterization data, (5) permits real-time data processing, and (6) can obtain soil, soil gas, and water samples without the need for a boring.

  20. Characterization of the Chronic Risk and Hazard of Hazardous Air Pollutants in the United States Using Ambient Monitoring Data

    PubMed Central

    McCarthy, Michael C.; O’Brien, Theresa E.; Charrier, Jessica G.; Hafner, Hilary R.

    2009-01-01

    Background Ambient measurements of hazardous air pollutants (air toxics) have been used to validate model-predicted concentrations of air toxics but have not been used to perform risk screening at the national level. Objectives We used ambient concentrations of routinely measured air toxics to determine the relative importance of individual air toxics for chronic cancer and noncancer exposures. Methods We compiled 3-year averages for ambient measurement of air toxics collected at monitoring locations in the United States from 2003 through 2005. We then used national distributions of risk-weighted concentrations to identify the air toxics of most concern. Results Concentrations of benzene, carbon tetrachloride, arsenic, 1,3-butadiene, and acetaldehyde were above the 10?6 cancer risk level at most sites nationally with a high degree of confidence. Concentrations of tetrachloroethylene, ethylene oxide, acrylonitrile, and 1,4-dichlorobenzene were also often greater than the 10?6 cancer risk level, but we have less confidence in the estimated risk associated with these pollutants. Formaldehyde and chromium VI concentrations were either above or below the 10?6 cancer risk level, depending on the choice of agency-recommended 10?6 level. The method detection limits of eight additional pollutants were too high to rule out that concentrations were above the 10?6 cancer risk level. Concentrations of 52 compounds compared with chronic noncancer benchmarks indicated that only acrolein concentrations were greater than the noncancer reference concentration at most monitoring sites. Conclusions Most pollutants with national site-level averages greater than health benchmarks were also pollutants of concern identified in modeled national-scale risk assessments. Current monitoring networks need more sensitive ambient measurement techniques to better characterize the air toxics problem in the United States. PMID:19479023

  1. Determination of geosmin and 2-methylisoborneol in water and wine samples by ultrasound-assisted dispersive liquid-liquid microextraction coupled to gas chromatography-mass spectrometry.

    PubMed

    Cortada, Carol; Vidal, Lorena; Canals, Antonio

    2011-01-01

    A fast, simple and environmentally friendly ultrasound-assisted dispersive liquid-liquid microextraction (USADLLME) procedure has been developed to preconcentrate geosmin and 2-methylisoborneol (MIB) from water and wine samples prior to quantification by gas chromatography-mass spectrometry (GC-MS). A two-stage multivariate optimization approach was developed by means of a Plackett-Burman design for screening and selecting the significant variables involved in the USADLLME procedure, which was later optimized by means of a circumscribed central composite design. The optimum conditions were: solvent volume, 8?L; solvent type: tetrachloroethylene; sample volume, 12 mL; centrifugation speed, 2300 rpm; extraction temperature 20 °C; extraction time, 3 min; and centrifugation time, 3 min. Under the optimized experimental conditions the method gave good levels of repeatability with coefficient of variation under 11% (n=10). Limits of detection were 2 and 9 ng L?¹ for geosmin and MIB, respectively. Calculated calibration curves gave high levels of linearity with correlation coefficient values of 0.9988 and 0.9994 for geosmin and MIB, respectively. Finally, the proposed method was applied to the analysis of two water (reservoir and tap) samples and three wine (red, rose and white) samples. The samples were previously analyzed and confirmed free of target analytes. Recovery values ranged between 70 and 113% at two spiking levels (0.25 ?g L?¹ and 30 ng L?¹) showing that the matrix had a negligible effect upon extraction. Only red wine showed a noticeable matrix effect (70-72% recovery). Similar conclusions have been obtained from an uncertainty budget evaluation study. PMID:21112591

  2. Exposure to carcinogens for defined job categories in Norway's offshore petroleum industry, 1970 to 2005

    PubMed Central

    Steinsvåg, Kjersti; Bråtveit, Magne; Moen, Bente E

    2007-01-01

    Objectives To identify and describe the exposure to selected known and suspected carcinogenic agents, mixtures and exposure circumstances for defined job categories in Norway's offshore petroleum industry from 1970 to 2005, in order to provide exposure information for a planned cohort study on cancer. Methods Background information on possible exposure was obtained through company visits, including interviewing key personnel (n?=?83) and collecting monitoring reports (n?=?118) and other relevant documents (n?=?329). On the basis of a previous questionnaire administered to present and former offshore employees in 1998, 27 job categories were defined. Results This study indicated possible exposure to 18 known and suspected carcinogenic agents, mixtures or exposure circumstances. Monitoring reports were obtained on seven agents (benzene, mineral oil mist and vapour, respirable and total dust, asbestos fibres, refractory ceramic fibres, formaldehyde and tetrachloroethylene). The mean exposure level of 367 personal samples of benzene was 0.037?ppm (range: less than the limit of detection to 2.6?ppm). Asbestos fibres were detected (0.03?fibres/cm3) when asbestos?containing brake bands were used in drilling draw work in 1988. Personal samples of formaldehyde in the process area ranged from 0.06 to 0.29?mg/m3. Descriptions of products containing known and suspected carcinogens, exposure sources and processes were extracted from the collected documentation and the interviews of key personnel. Conclusions This study described exposure to 18 known and suspected carcinogenic agents, mixtures and exposure circumstances for 27 job categories in Norway's offshore petroleum industry. For a planned cohort study on cancer, quantitative estimates of exposure to benzene, and mineral oil mist and vapour might be developed. For the other agents, information in the present study can be used for further assessment of exposure, for instance, by expert judgement. More systematic exposure surveillance is needed in this industry. For future studies, new monitoring programmes need to be implemented. PMID:17043075

  3. Dechlorination of chlorinated hydrocarbons by bimetallic Ni/Fe immobilized on polyethylene glycol-grafted microfiltration membranes under anoxic conditions.

    PubMed

    Parshetti, Ganesh K; Doong, Ruey-an

    2012-01-01

    In this study, the dechlorination of chlorinated hydrocarbons including trichloroethylene (TCE), tetrachloroethylene (PCE) and carbon tetrachloride (CT) by bimetallic Ni/Fe nanoparticles immobilized on four different membranes was investigated under anoxic conditions. Effects of several parameters including the nature of membrane, initial concentration, pH value, and reaction temperature on the dechlorination efficiency were examined. The scanning electron microscopic images showed that the Ni/Fe nanoparticles were successfully immobilized inside the four membranes using polyethylene glycol as the cross-linker. The agglomeration of Ni/Fe were observed in poly(vinylidene fluoride), Millex GS and mixed cellulose ester membranes, while a relatively uniform distribution of Ni/Fe was found in nylon-66 membrane because of its hydrophilic nature. The immobilized Ni/Fe nanoparticles exhibited good reactivity towards the dechlorination of chlorinated hydrocarbons, and the pseudo-first-order rate constant for TCE dechlorination by Ni/Fe in nylon-66 were 3.7-11.7 times higher than those in other membranes. In addition, the dechlorination efficiency of chlorinated hydrocarbons followed the order TCE>PCE>CT. Ethane was the only end product for TCE and PCE dechlorination, while dichloromethane and methane were found to be the major products for CT dechlorination, clearly indicating the involvement of reactive hydrogen species in dechlorination. In addition, the initial rate constant for TCE dechlorination increased upon increasing initial TCE concentrations and the activation energy for TCE dechlorination by immobilized Ni/Fe was 34.9 kJ mol(-1), showing that the dechlorination of TCE by membrane-supported Ni/Fe nanoparticles is a surface-mediated reaction. PMID:22115467

  4. Distribution of volatile organic compounds in a New Jersey coastal plain aquifer system

    USGS Publications Warehouse

    Fusillo, T.V.; Hochreiter, J.J., Jr.; Lord, D.G.

    1985-01-01

    Samples for analysis of volatile organic compounds were collected from 315 wells in the Potomac-Raritan-Magothy aquifer system in southwestern New Jersey and a small adjacent area in Pennsylvania during 1980-82. Volatile organic compounds were detected in all three aquifer units of the Potomac-Raritan-Magoth aquifer system in the study area. Most of the contamination appears to be confined to the outcrop area at present. Low levels of contamination, however, were found downdip of the outcrop area in the upper and middle aquifers. Trichloroethylene, tetrachloroethylene, and benzene were the most frequently detected compounds. Differences in the areal distributions of light chlorinated hydrocarbons, such as trichloroethylene, and aromatic hydrocarbons, such as benzene, were noted and are probably due to differences in the uses of the compounds and the distribution patterns of potential contamination sources. The distribution patterns of volatile organic compounds differed greatly among the three aquifer units. The upper aquifer, which crops out mostly in less-developed areas, had the lowest percentage of wells with volatile organic compounds detected (10 percent of wells sampled). The concentrations in most wells in the upper aquifer which had detectable levels were less than 10 ??g/l. In the middle aquifer, which crops out beneath much of the urban and industrial area adjacent to the Delaware River, detectable levels of volatile organic compounds were found in 22 percent of wells sampled, and several wells contained concentrations above 100 ??g/l. The lower aquifer, which is confined beneath much of the outcrop area of the aquifer system, had the highest percentage of wells (28 percent) with detectable levels. This is probably due to (1) vertical leakage of contamination from the middle aquifer, and (2) the high percentage of wells tapping the lower aquifer in the most heavily developed areas of the outcrop.

  5. Characterization Report to Support the Phytoremediation Efforts for Southern Sector, Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Jerome, K.M.

    1999-06-08

    In February, 1999, we conducted a small-scale characterization effort to support future remediation decisions for the Southern Sector of the upper Three Runs watershed. The study concentrated on groundwater adjacent to the seepline at Tim's Branch above and below Steed's Pond. the primary compounds of interest were the volatile organic contaminants (VOCs), trichlorethylene (TCE) and tetrachloroethylene (PCE). Due to the site topography and hydrogeology, samples collected north of Steed's Pond were from the M-Area (water table) aquifer; while those locations south of Steed's Pond provided samples from the Lost Lake aquifer. Results of the study suggest that the leading edge of the A/M Area plume in the Lost Lake aquifer may be approaching the seepline at Tim's Branch below Steed's Pond, south of Road 2. Neither TCE nor PCE were detected int he samples targeting the seepline of the water table aquifer. The concentrations found for both TCE and PCE associated with the Lost Lake aquifer outcrop region were slightly above the detection limit of the analytical instrument used. The findings of this study are consistent with the conceptual model for the organic contaminant plume in the A/M Area of the Savannah River Site (SRS) -- the plume in the Southern Sector is known to be depth discrete and primarily in the Lost lake Aquifer. The sites with detected VOCs are in the most upstream accessible reaches of Tim's Branch where water from the Lost Lake Aquifer crops out. Additional characterization efforts should be directed near this region to confirm the results and to support future planning for the dilute-distal portions of the A/M Area plume. These data, combined with existing groundwater plume data and future characterization results will provide key information to estimate potential contaminant flux to the seepline and to assess the effectiveness of potential clean-up activities such as phytoremediation.

  6. Simultaneous analysis of 28 urinary VOC metabolites using ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI/MSMS).

    PubMed

    Alwis, K Udeni; Blount, Benjamin C; Britt, April S; Patel, Dhrusti; Ashley, David L

    2012-10-31

    Volatile organic compounds (VOCs) are ubiquitous in the environment, originating from many different natural and anthropogenic sources, including tobacco smoke. Long-term exposure to certain VOCs may increase the risk for cancer, birth defects, and neurocognitive impairment. Therefore, VOC exposure is an area of significant public health concern. Urinary VOC metabolites are useful biomarkers for assessing VOC exposure because of non-invasiveness of sampling and longer physiological half-lives of urinary metabolites compared with VOCs in blood and breath. We developed a method using reversed-phase ultra high performance liquid chromatography (UPLC) coupled with electrospray ionization tandem mass spectrometry (ESI/MSMS) to simultaneously quantify 28 urinary VOC metabolites as biomarkers of exposure. We describe a method that monitors metabolites of acrolein, acrylamide, acrylonitrile, benzene, 1-bromopropane, 1,3-butadiene, carbon-disulfide, crotonaldehyde, cyanide, N,N-dimethylformamide, ethylbenzene, ethylene oxide, propylene oxide, styrene, tetrachloroethylene, toluene, trichloroethylene, vinyl chloride and xylene. The method is accurate (mean accuracy for spiked matrix ranged from 84 to 104%), sensitive (limit of detection ranged from 0.5 to 20 ng mL(-1)) and precise (the relative standard deviations ranged from 2.5 to 11%). We applied this method to urine samples collected from 1203 non-smokers and 347 smokers and demonstrated that smokers have significantly elevated levels of tobacco-related biomarkers compared to non-smokers. We found significant (p<0.0001) correlations between serum cotinine and most of the tobacco-related biomarkers measured. These findings confirm that this method can effectively quantify urinary VOC metabolites in a population exposed to volatile organics. PMID:23062436

  7. Spectral Induced Polarization Response of Unconsolidated Saturated Sand and Surfactant Solutions

    NASA Astrophysics Data System (ADS)

    Magill, M. T.; Werkema, D.; Kreamer, D. K.

    2008-12-01

    Dense non-aqueous phase liquids (DNAPL), such as chlorinated solvents, are common groundwater contaminants. Traditional pump-and-treat methods are often not effective at removing residual DNAPL from the subsurface. Surfactant-enhanced aquifer remediation is a promising remediation method that utilizes subsurface surfactant floods to decrease the interfacial tension between the non-aqueous phase and groundwater and increase the contaminant solubility and mobility in water. This remediation method is not widely used because of unknown subsurface distribution and effectiveness. The ability to effectively monitor and perhaps map the spatial distribution of surfactant floods used in remediation could reduce monitoring uncertainty and increase their use. Previous work has shown that surfactants in aqueous solutions significantly alter the solution conductivity, but this work has not investigated the surfactant response in aquifer type materials. In this project, spectral induced polarization measurements of four surfactant aqueous solutions in a sand matrix were evaluated. The frequency range assessed was 0.732 Hz to 187.5 Hz. The surfactants, which are typically used in the remediation of tetrachloroethylene, were Aerosol MA-80-I, Dowfax 8390, and Steol CS-330. These surfactant solutions were injected into a closed system of 20-30 Ottawa silica sand. Resistivity and phase responses were measured. The surfactant treatments altered both phase and resistivity in varying degrees, with Aerosol MA-80-I showing a marked decrease in both, and the Steol CS- 330 exhibiting little change relative to the control column. These results suggest geoelectrical property changes may be an applicable property to map and monitor surfactant floods in the subsurface. Future work will continue to investigate this application.

  8. Three phase biological treatment process for chlorinated compounds in air streams

    SciTech Connect

    Parker, W.J.; Collins, J.; Wells, J.; Kennedy, K.

    1999-07-01

    A combination of experimental and modeling studies were carried out to evaluate the potential for biological treatment of air streams containing chlorinated organics in a hybrid process. The proposed process consists of a scrubbing column for transferring chlorinated compounds from the gas to the liquid phase and a high rate anaerobic reactor for biodegradation of the compounds. Carbon tetrachloride, tetrachloroethylene and dichloromethane were employed as target compounds in this study to assess compounds with a range of chemical, physical and biological properties. Batch tests provided conclusive evidence that the target compounds strongly partition to vegetable oil. Continuous flow test results suggested that high removal efficiencies for all three compounds ({gt}90%) could be obtained with gas-liquid flow ratios less than 200. It was found that the Onda correlations did not fit the experimental data of vegetable oil very well, hence the Onda correlations were modified by assuming that the gas phase resistance was controlling mass transfer. The assumption appeared to be valid for the compounds with lower gas-oil partitioning coefficients (CT and PCE). DCM appeared to have some component of liquid phase control. Experiments were conducted in high rate anaerobic reactors to evaluate the impact of cosubstrate loading and hydraulic retention time on the biodegradation of the target compounds. Removals approached 100% for all three target compounds when the UASB was operated at high values of OLR and HRT. Removals for PCE and DCM decreased when the UASB was run under more strenuous conditions. A hybrid anaerobic reactor that consisted of a liquid-liquid mass transfer zone and an anaerobic biodegradation zone was operated to assess the processes potential to degrade the target compounds when they entered in a vegetable oil matrix.

  9. Application of a new vertical profiling tool (ESASS) for sampling groundwater quality during hollow-stem auger drilling

    USGS Publications Warehouse

    Harte, P.T.; Flanagan, S.M.

    2011-01-01

    A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth-specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305-m long screen auger during hollow-stem auger drilling. With ESASS, the water column in the flights above the screen auger is separated from the water in the screen auger by a specially designed removable plug and collar. The tool fits inside an auger of standard inner diameter (82.55 mm). The novel design of the system constituted by the plug, collar, and A-rod allows the plug to be retrieved using conventional drilling A-rods. After retrieval, standard-diameter (50.8 mm) observation wells can be installed within the hollow-stem augers. Testing of ESASS was conducted at one waste-disposal site with tetrachloroethylene (PCE) contamination and at two reference sites with no known waste-disposal history. All three sites have similar geology and are underlain by glacial, stratified-drift deposits. For the applications tested, ESASS proved to be a useful tool in vertical profiling of groundwater quality. At the waste site, PCE concentrations measured with ESASS profiling at several depths were comparable (relative percent difference <25%) to PCE concentrations sampled from wells. Vertical profiling with ESASS at the reference sites illustrated the vertical resolution achievable in the profile system; shallow groundwater quality varied by a factor of five in concentration of some constituents (nitrate and nitrite) over short (0.61 m) distances. Ground Water Monitoring & Remediation ?? 2011, National Ground Water Association. No claim to original US government works.

  10. Application of a new vertical profiling tool (ESASS) for sampling groundwater quality during hollow-stem auger drilling

    USGS Publications Warehouse

    Harte, Philip T.; Flanagan, Sarah M.

    2011-01-01

    A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth-specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305-m long screen auger during hollow-stem auger drilling. With ESASS, the water column in the flights above the screen auger is separated from the water in the screen auger by a specially designed removable plug and collar. The tool fits inside an auger of standard inner diameter (82.55 mm). The novel design of the system constituted by the plug, collar, and A-rod allows the plug to be retrieved using conventional drilling A-rods. After retrieval, standard-diameter (50.8 mm) observation wells can be installed within the hollow-stem augers. Testing of ESASS was conducted at one waste-disposal site with tetrachloroethylene (PCE) contamination and at two reference sites with no known waste-disposal history. All three sites have similar geology and are underlain by glacial, stratified-drift deposits. For the applications tested, ESASS proved to be a useful tool in vertical profiling of groundwater quality. At the waste site, PCE concentrations measured with ESASS profiling at several depths were comparable (relative percent difference <25%) to PCE concentrations sampled from wells. Vertical profiling with ESASS at the reference sites illustrated the vertical resolution achievable in the profile system; shallow groundwater quality varied by a factor of five in concentration of some constituents (nitrate and nitrite) over short (0.61 m) distances.

  11. Reconnaissance of volatile organic compounds in the subsurface at Rutgers University, Busch Campus, Piscataway Township, New Jersey

    USGS Publications Warehouse

    dePaul, V.T.

    1996-01-01

    During 1991-92, the U.S. Geological Survey conducted a hydrogeologic reconnaissance at a site near the Rutgers University, Busch Campus, Chemical Engineering building, C-Wing. Results of analyses of the soil-gas samples, which were collected at 43 locations, indicated the presence of volatile organic compounds, primarily carbon tetrachloride, near the C-Wing building and about 550 feet downgradient from and southwest of the C-Wing building. Concentrations of the compound in soil-gas samples were highest (2.1 ug/L (micrograms per liter)) along the southwestern wall of the C-Wing building. Ground-water samples were collected at depths as great as 55 feet from five wells and piezometers near the C-Wing building. Samples collected along the southwestern wall of the building also contained the highest concentrations of volatile organic compounds. Concentrations of carbon tetrachloride in the ground-water samples ranged from < 0.35 ug/L to 3,400 ug/L, and concentrations of tetrachloro- ethylene ranged from < 0.28 ug/L to 85 ug/L. Ground-water samples collected at depths of 55 feet or more from two wells located on the Rutgers University Golf Course about 2,400 feet down- gradient from the C-Wing building contained concentrations of tetrachloroethylene as great as 17.7 ug/L. Water levels measured in six wells and six piezometers indicated that the general flow direction in the shallow part of the aquifer is to the southwest of the C-Wing building. An electrical-resistivity survey was conducted by azimuthal resistivity techniques. The results of the survey were consistent with field measurements, and the dominant vertical fractures near the Busch Campus trend northeast. An electromagnetic survey was ineffective as a result of cultural interferences and could not be used to determine the hydrogeologic characteristics of the site.

  12. Ultrasound-assisted dispersive liquid-liquid microextraction plus simultaneous silylation for rapid determination of salicylate and benzophenone-type ultraviolet filters in aqueous samples.

    PubMed

    Wu, Jen-Wen; Chen, Hsin-Chang; Ding, Wang-Hsien

    2013-08-01

    A rapid procedure, using minimal amounts of solvent, for the reliable determination of five salicylate and benzophenone-type ultraviolet (UV) filters: ethylhexyl salicylate (EHS), 3,3,5-trimethyl-cyclohexyl salicylate (HMS), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,4-dihydroxy-benzophenone (BP-1) and 2,2'-dihydroxy-4-methoxybenzophenone (BP-8), in aqueous samples is described. The method involves an ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) plus simultaneous silylation prior to their determination by gas chromatography-mass spectrometry (GC-MS). The parameters affecting the extraction and derivatization efficiency of the target UV filters from aqueous samples were systematically investigated and the conditions optimized. The optimal silylation and extraction conditions involved the rapid injection of a mixture of 750?L of acetone (as a dispersant), 15?L of tetrachloroethylene (as an extractant), and 20?L of BSTFA (as a derivatizing agent) into a 10-mL volume of aqueous samples (pH 7.0) containing 0.5g of sodium chloride in a glass tube with a conical bottom. After ultrasonication for 2.0min and centrifugation at 5000rpm (10min), the sedimented phase 5.0?L was directly introduced into the GC-MS. The limits of quantitation (LOQs) were less than 6ng/L. The precision for these analytes, as indicated by the relative standard deviations (RSDs), was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 74 and 92%. The method was then applied to environmental aqueous samples, using a standard addition method, showing the occurrence of BP-3 in samples of both river water and municipal wastewater treatment plant (MWTP) effluents. PMID:23831000

  13. Occupational cancer burden in Great Britain

    PubMed Central

    Rushton, Lesley; Hutchings, Sally J; Fortunato, Lea; Young, Charlotte; Evans, Gareth S; Brown, Terry; Bevan, Ruth; Slack, Rebecca; Holmes, Phillip; Bagga, Sanjeev; Cherrie, John W; Van Tongeren, Martie

    2012-01-01

    A sound knowledge base is required to target resources to reduce workplace exposure to carcinogens. This project aimed to provide an objective estimate of the burden of cancer in Britain due to occupation. This volume presents extensive analyses for all carcinogens and occupational circumstances defined as definite or probable human occupational carcinogens by the International Agency for Research on Cancer. This article outlines the structure of the supplement – two methodological papers (statistical approach and exposure assessment), eight papers presenting the cancer-specific results grouped by broad anatomical site, a paper giving industry sector results and one discussing work-related cancer-prevention strategies. A brief summary of the methods and an overview of the updated overall results are given in this introductory paper. A general discussion of the overall strengths and limitations of the study is also presented. Overall, 8010 (5.3%) total cancer deaths in Britain and 13,?598 cancer registrations were attributable to occupation in 2005 and 2004, respectively. The importance of cancer sites such as mesothelioma, sinonasal, lung, nasopharynx, breast, non-melanoma skin cancer, bladder, oesophagus, soft tissue sarcoma and stomach cancers are highlighted, as are carcinogens such as asbestos, mineral oils, solar radiation, silica, diesel engine exhaust, coal tars and pitches, dioxins, environmental tobacco smoke, radon, tetrachloroethylene, arsenic and strong inorganic mists, as well as occupational circumstances such as shift work and occupation as a painter or welder. The methods developed for this project are being adapted by other countries and extended to include social and economic impact evaluation. PMID:22710676

  14. The effect of BTEX compounds on aerobic cometabolism of vinyl chloride by ethylene grown enrichment cultures

    SciTech Connect

    Freedman, D.L.; Williamson, A.E.

    1996-12-31

    There is mounting field evidence that groundwater contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE) can be efficiently treated in situ by stimulating anaerobic reductive dechlorination, producing primarily ethylene and/or ethane. However, persistence of vinyl chloride (VC), even at low levels, may result in the need for subsequent aerobic treatment. A recent study by Freedman and Herz (1995) indicated that ethylene and ethane can serve as the primary substrates for aerobic cometabolism of VC, thereby avoiding the need to add an exogenous primary substrate. At many sites where PCE and TCE are found, other organic contaminants are also prevalent in mixtures. Chief among these are BTEX compounds (benzene (BEN), toluene (TOL), ethylbenzene (EBZ) and o-xylene (XYL)). Except for TOL, a limited amount of BTEX biodegradation is typically expected under anaerobic conditions, so most of the BTEX that occurs with PCE and TCE is likely to reach the aerobic zone along with VC, ethylene, and ethane. The objective of this study was to determine the effect of BTEX compounds on aerobic biodegradation of ethylene and VC. In an ethylene-grown enrichment culture, addition of BEN, EBZ, and TOL (6-59 mg/L) inhibited the initial rate of ethylene and VC biodegradation by 75% and 67%, respectively. The lower concentration of XYL added (0.80 mg/L) had a minor effect. As the rate of BEN, EBZ, and TOL biodegradation improved with time, no further inhibition of VC and ethylene consumption was observed. A population of BTEX degrading organisms developed in the ethylene-grown culture, but this did not result in a faster rate of VC or ethylene use. Separately developed BEN- and TOL-grown enrichment cultures confirmed this. Neither aromatic enrichment culture was able to biodegrade VC or ethylene, but both were able to consume all of the other aromatic compounds.

  15. Concentrations, loads and yields of selected water-quality constituents during low flow and storm runoff from three watersheds at Fort Leavenworth, Kansas, May 1994 through September 1996

    USGS Publications Warehouse

    Rasmussen, P.P.

    1998-01-01

    A study of the effects of storm runoff from urban areas on water quality at Fort Leavenworth, Kansas, was conducted from May 1994 through September 1996. The purpose of this report is to present information to assess the current (1994-96) conditions and possible methods for anticipating future water-quality effects from storm runoff and changes in land use. Three sampling sites were established to monitor streamflow and water quality from three watersheds draining the study area. Streamflow was monitored continuously, and water-quality samples were collected during low-flow (12 samples) and storm-runoff (21 samples) conditions to determine mean annual constituent loads. Constituent concentrations for the most part were smallest during low flow with the exception of major ions, dissolved solids, and some nutrients. Concentrations of suspended solids and total recoverable metals at all three sites were much larger in storm-runoff samples than in low-flow samples--typically an order of magnitude larger than low-flow concentrations. Mean low-flow nutrient concentrations were either larger than or smaller than storm-runoff concentrations depending on the watershed. Total chloroform and total tetrachloroethylene were the only two volatile organic compounds detected, and acid-base/neutral organic compounds were not detected in any of the samples collected. Eight pesticides were detected in low-flow samples, and 15 pesticides were detected in storm-runoff samples. The only mean concentrations of the selected constituents in this study that exceeded either the U.S. Environmental Protection Agency's Maximum Contaminant Level or the Secondary Maximum Contaminant Level were dissolved solids and total recoverable iron and manganese.

  16. Attenuation of methane and volatile organic compounds in landfill soil covers.

    PubMed

    Scheutz, Charlotte; Mosbaek, Hans; Kjeldsen, Peter

    2004-01-01

    The potential for natural attenuation of volatile organic compounds (VOCs) in landfill covers was investigated in soil microcosms incubated with methane and air, simulating the gas composition in landfill soil covers. Soil was sampled at Skellingsted Landfill at a location emitting methane. In total, 26 VOCs were investigated, including chlorinated methanes, ethanes, ethenes, fluorinated hydrocarbons, and aromatic hydrocarbons. The soil showed a high capacity for methane oxidation resulting in very high oxidation rates of between 24 and 112 microg CH4 g(-1) h(-1). All lower chlorinated compounds were shown degradable, and the degradation occurred in parallel with the oxidation of methane. In general, the degradation rates of the chlorinated aliphatics were inversely related to the chlorine to carbon ratios. For example, in batch experiments with chlorinated ethylenes, the highest rates were observed for vinyl chloride (VC) and lowest rates for trichloroethylene (TCE), while tetrachloroethylene (PCE) was not degraded. Maximal oxidation rates for the halogenated aliphatic compounds varied between 0.03 and 1.7 microg g(-1) h(-1). Fully halogenated hydrocarbons (PCE, tetrachloromethane [TeCM], chlorofluorocarbon [CFC]-11, CFC-12, and CFC-113) were not degraded in the presence of methane and oxygen. Aromatic hydrocarbons were rapidly degraded giving high maximal oxidation rates (0.17-1.4 microg g(-1) h(-1)). The capacity for methane oxidation was related to the depth of oxygen penetration. The methane oxidizers were very active in oxidizing methane and the selected trace components down to a depth of 50 cm below the surface. Maximal oxidation activity occurred in a zone between 15 and 20 cm below the surface, as this depth allowed sufficient supply of both methane and oxygen. Mass balance calculations using the maximal oxidation rates obtained demonstrated that landfill soil covers have a significant potential for not only methane oxidation but also cometabolic degradation of selected volatile organics, thereby reducing emissions to the atmosphere. PMID:14964359

  17. Ambient air benzene at background sites in China's most developed coastal regions: Exposure levels, source implications and health risks.

    PubMed

    Zhang, Zhou; Wang, Xinming; Zhang, Yanli; Lü, Sujun; Huang, Zhonghui; Huang, Xinyu; Wang, Yuesi

    2015-04-01

    Benzene is a known human carcinogen causing leukemia, yet ambient air quality objectives for benzene are not available in China. The ambient benzene levels at four background sites in China's most developed coastal regions were measured from March 2012 to February 2013. The sites are: SYNECP, in the Northeast China Plain (NECP); YCNCP, in the North China Plain (NCP); THYRD, in the Yangtze River Delta (YRD) and DHPRD, in the Pearl River Delta (PRD). It was found that the mean annual benzene levels (578-1297ppt) at the background sites were alarmingly higher, especially when compared to those of 60-480pptv monitored in 28 cities in the United States. Wintertime benzene levels were significantly elevated at both sites (SYNECP and YCNCP) in northern China due to heating with coal/biofuels. Even at these background sites, the lifetime cancer risks of benzene (1.7-3.7E-05) all exceeded 1E-06 set by USEPA as acceptable for adults. At both sites in northern China, good correlations between benzene and CO or chloromethane, together with much lower toluene/benzene (T/B) ratios, suggested that benzene was largely related to coal combustion and biomass/biofuel burning. At the DHPRD site in the PRD, benzene revealed a highly significant correlation with methyl tert-butyl ether (MTBE), indicating that its source was predominantly from vehicle emissions. At the THYRD site in the YRD, higher T/B ratios and correlations between benzene and tetrachloroethylene, or MTBE, implied that benzene levels were probably affected by both traffic-related and industrial emissions. PMID:25618820

  18. Demonstration of alternatives for vapor degreasers

    SciTech Connect

    Menke, D.; Sawhney, R. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-10-01

    The {open_quotes}Cleaner Technology Demonstrations for the 33/50 Chemicals{close_quotes} is a cooperative agreement project between the Center for Clean Products and Clean Technologies and the U.S. EPA. Though originally designed to support the 33/50 Program, the results of this RREL-funded research will have a broad range of applications within industry and offer pollution prevention benefits beyond the 33/50 goals. The overall objective of this project is to evaluate substitutes of the 33/50 chemicals in order to encourage reductions in their use and release within specified priority use clusters. Priority use clusters, identified in the {open_quotes}Product Side of Pollution Prevention: Evaluating Safe Substitutes for the 33/50 Chemicals{close_quotes} report, are products and/or processes that consume a significant fraction of the 33/50 chemicals. The first evaluation, presented here, focused on the metal and parts degreasing priority use cluster and specifically substitutes for solvent degreasing processes that eliminate the use of the chlorinated degreasing solvent dichloromethane, tetrachloroethylene, 1,1,1-trichloroethane, and trichloroethylene. In this study the Center for Clean Products worked directly with an industry partner to demonstrate substitute feasibility and to gain actual industrial information. Calsonic Manufacturing Corporation (CMC) is aggressively pursuing less polluting alternatives to solvent degreasing and agreed to participate as the Center`s industrial partner to demonstrate solvent degreasing substitutes. CMC manufactures automotive parts included heaters, blowers, cooling units, motor fans, radiators, auxiliary oil coolers, and exhaust systems. Over the past four years, CMC had evaluated and implemented a number of environmental improvements to completely eliminate 1,1,1-trichloroethane (TCA) from their degreasing processes.

  19. Water-Quality Data for Pharmaceuticals and Other Organic Wastewater Contaminants in Ground Water and in Untreated Drinking Water Sources in the United States, 2000-01

    USGS Publications Warehouse

    Barnes, Kimberlee K.; Kolpin, Dana W.; Focazio, Michael J.; Furlong, Edward T.; Meyer, Michael T.; Zaugg, Steven D.; Haack, Sheridan K.; Barber, Larry B.; Thurman, E. Michael

    2008-01-01

    This report presents water-quality data from two nationwide studies on the occurrence and distribution of organic wastewater contaminants. These data are part of the continuing effort of the U.S. Geological Survey Toxic Substances Hydrology Program to collect baseline information on the environmental occurrence of pharmaceuticals and other organic wastewater contaminants. In 2000, samples were collected from 47 ambient ground-water sites (not drinking-water wells) in 18 states and analyzed for 65 organic wastewater contaminants. In the summer of 2001, samples were collected from 74 sources of raw, untreated, drinking water in 25 states and Puerto Rico and analyzed for 100 organic wastewater contaminants. These sources comprise 25 ground-water and 49 surface-water sources of drinking water serving populations ranging from one family to more than 8 million people. Site selection for both studies focused on areas known or suspected to contain sources of animal and/or human wastewater. The five most frequently detected compounds in samples collected from ambient ground-water sites are N,N-diethyltoluamide (35 percent, insect repellant), bisphenol A (30 percent, plasticizer), tri(2-chloroethy) phosphate (30 percent, fire retardant), sulfamethoxazole (23 percent, veterinary and human antibiotic), and 4-octylphenol monoethoxylate (19 percent, detergent metabolite). The five most frequently detected organic wastewater contaminants in samples of untreated drinking water from surface-water sources are cholesterol (59 percent, natural sterol), metolachlor (53 percent, herbicide), cotinine (51 percent, nicotine metabolite), B -sitosterol (37 percent, natural plant sterol), and 1,7-dimethylxanthine (27 percent, caffeine metabolite). The five most frequently detected organic wastewater contaminants in samples of untreated drinking water from ground-water sources are tetrachloroethylene (24 percent, solvent), carbamazepine (20 percent, pharmaceutical), bisphenol A (20 percent, plasticizer), 1,7-dimethylxanthine (16 percent, caffeine metabolite), and tri(2-chloroethyl) phosphate (12 percent, fire retardant).

  20. Semi-analytical Solution of One-dimensional Multispecies Reactive Transport in a Permeable Reactive Barrier-aquifer System

    NASA Astrophysics Data System (ADS)

    Mieles, J. M.; Zhan, H.

    2010-12-01

    Permeable reactive barriers (PRBs) have been accepted by the EPA as an effective groundwater remediation technology. Effective implementation of this in-situ technology requires accurate site characterization to identify the chemicals of concern (COCs) present, their interactions (if any), and their required residence time in the PRB to achieve regulatory concentrations at the point of compliance (POC). Therefore, minimizing performance uncertainties in the design phase is key. Among these uncertainties determining the required PRB thickness is the most important and has been examined in other studies. Less attention, however, has been devoted to developing a practical yet rigorous tool for modeling multi-species reactive transport in the barrier-aquifer system. In this study Park and Zhan’s [2009] mass conservative semi-analytical solution - developed to calculate the required PRB thickness based on the decay of one species - is expanded to four reactive species. For example, the expanded solution could be used to model the degradation pathway from tetrachloroethylene (PCE) to vinyl chloride (VC). The solution is presented in two forms: The steady-state solution programmed into Excel can quickly assist designers in determining the required PRB thickness so that all COCs involved in the degradation pathway achieve regulatory limits at the POC. The second form is the transient solution which is solved by numerically inverting the Laplace transform. The semi-analytical solution presented in this study has several advantages over prior solutions. For example, the influent and effluent boundary conditions of the PRB are mass conservative and both dispersion and decay rate differences between the PRB and aquifer are considered. In addition, the transient solution allows for different retardation factors to be considered in both transport media and for each species.

  1. Aromatic hydrocarbons as ozone precursors before and after outbreak of the 2008 financial crisis in the Pearl River Delta region, south China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanli; Wang, Xinming; Blake, Donald R.; Li, Longfeng; Zhang, Zhou; Wang, Shaoyi; Guo, Hai; Lee, Frank S. C.; Gao, Bo; Chan, Loyin; Wu, Dui; Rowland, F. Sherwood

    2012-08-01

    In the second half of 2008 China's highly industrialized Pearl River Delta (PRD) region was hard-hit by the financial crisis (FC). This study reports volatile organic compounds measured in the PRD during November-December in both 2007 before the FC and 2008 after the FC. While total mixing ratios of non-methane hydrocarbons (NMHCs) on average were only about 7% lower from 40.2 ppbv in 2007 to 37.5 ppbv in 2008, their ozone formation potentials (OFPs) dropped about 30%, resulting from about 55% plummet of aromatic hydrocarbons (AHs) against a greater than 20% increase of total alkanes/alkenes. The elevated alkanes and alkenes in 2008 could be explained by greater emissions from vehicle exhausts and LPG combustion due to rapid increase of vehicle numbers and LPG consumption; the drop of AHs could be explained by reduced emissions from industries using AH-containing solvents due to the influence of the FC, as indicated by much lower ratios of toluene to benzene and of xylenes/trichloroethylene/tetrachloroethylene to carbon monoxide (CO) in 2008. Source apportionment by positive matrix factorization (PMF) also revealed much less contribution of industry solvents to total anthropogenic NMHCs and particularly to toluene and xylenes in 2008 than in 2007. Based on PMF reconstructed source contributions, calculated OFPs by industrial emissions were responsible for 40.8% in 2007 in contrast to 18.4% in 2008. Further investigation into local industry output statistics suggested that the plummet of AHs in 2008 should be attributed to small enterprises, which contributed largely to ambient AHs due to their huge numbers and non-existent emission treatment, but were much more influenced by the FC.

  2. A Modified Light Transmission Visualization Method for DNAPL Saturation Measurements in 2-D Models

    NASA Astrophysics Data System (ADS)

    Bob, M. M.; Brooks, M. C.; Mravik, S. C.; Wood, L.

    2007-12-01

    In this research, a light transmission visualization (LTV) method was used to quantify dense non-aqueous phase liquids (DNAPL) saturation in two-dimensional (2-D), two fluid phase systems. The method is an expansion of earlier LTV methods and takes into account both absorption and refraction light theories. Based on this method, DNAPL and water saturations can rapidly be obtained point wise across sand-packed 2-D flow chambers without the need to develop a calibration curve. The method was applied to measure, for the first time, undyed DNAPL saturation in small 2-D chambers. Known amounts of DNAPL, modeled by tetrachloroethylene (PCE), were added to the chamber and these amounts were compared to results obtained by this LTV method. Strong correlation existed between results obtained based on this method and the known PCE amounts with an R2 value of 0.993. Similar experiments conducted using dyed PCE showed a stronger correlation between results obtained by this LTV method and the known amounts of dyed PCE added to the chamber with an R2 value of 0.999. The method was also used to measure dyed PCE saturation in a large 2-D model following sparging experiments. Results obtained from image analyses following each sparging event were compared to results obtained by two independent techniques, namely gas chromatography-mass spectrometry (GC/MS) analyses and carbon column extraction. There was a good agreement between the results obtained by this LTV method and those obtained by the two independent techniques when experiments were carried out under stable light source conditions, and errors in mass balance were minor. The method presented here can be expanded to measure fluid contents in three fluid phase systems and provide a non-destructive, non-intrusive tool to investigate changes in DNAPL architecture and flow characteristics in laboratory experiments. Disclaimer This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.

  3. A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States--II) untreated drinking water sources.

    PubMed

    Focazio, Michael J; Kolpin, Dana W; Barnes, Kimberlee K; Furlong, Edward T; Meyer, Michael T; Zaugg, Steven D; Barber, Larry B; Thurman, Michael E

    2008-09-01

    Numerous studies have shown that a variety of manufactured and natural organic compounds such as pharmaceuticals, steroids, surfactants, flame retardants, fragrances, plasticizers and other chemicals often associated with wastewaters have been detected in the vicinity of municipal wastewater discharges and livestock agricultural facilities. To provide new data and insights about the environmental presence of some of these chemicals in untreated sources of drinking water in the United States targeted sites were sampled and analyzed for 100 analytes with sub-parts per billion detection capabilities. The sites included 25 ground- and 49 surface-water sources of drinking water serving populations ranging from one family to over 8 million people. Sixty-three of the 100 targeted chemicals were detected in at least one water sample. Interestingly, in spite of the low detection levels 60% of the 36 pharmaceuticals (including prescription drugs and antibiotics) analyzed were not detected in any water sample. The five most frequently detected chemicals targeted in surface water were: cholesterol (59%, natural sterol), metolachlor (53%, herbicide), cotinine (51%, nicotine metabolite), beta-sitosterol (37%, natural plant sterol), and 1,7-dimethylxanthine (27%, caffeine metabolite); and in ground water: tetrachloroethylene (24%, solvent), carbamazepine (20%, pharmaceutical), bisphenol-A (20%, plasticizer), 1,7-dimethylxanthine (16%, caffeine metabolite), and tri (2-chloroethyl) phosphate (12%, fire retardant). A median of 4 compounds were detected per site indicating that the targeted chemicals generally occur in mixtures (commonly near detection levels) in the environment and likely originate from a variety of animal and human uses and waste sources. These data will help prioritize and determine the need, if any, for future occurrence, fate and transport, and health-effects research for subsets of these chemicals and their degradates most likely to be found in water resources used for drinking water in the United States. PMID:18433838

  4. Assessment of soil-gas contamination at three former fuel-dispensing sites, Fort Gordon, Georgia, 2010—2011

    USGS Publications Warehouse

    Caldwell, Andral W.; Falls, W. Fred; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Soil gas was assessed for contaminants at three former fuel-dispensing sites at Fort Gordon, Georgia, from October 2010 to September 2011. The assessment included delineation of organic contaminants using soil-gas samplers collected from the former fuel-dispensing sites at 8th Street, Chamberlain Avenue, and 12th Street. This assessment was conducted to provide environmental contamination data to Fort Gordon personnel pursuant to requirements for the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Soil-gas samplers installed and retrieved during June and August 2011 at the 8th Street site had detections above the method detection level (MDL) for the mass of total petroleum hydrocarbons (TPH), benzene, toluene, ortho-xylene, undecane, tridecane, pentadecane, and chloroform. Total petroleum hydrocarbons soil-gas mass exceeded the MDL of 0.02 microgram in 54 of the 55 soil-gas samplers. The highest detection of TPH soil-gas mass was 146.10 micrograms, located in the central part of the site. Benzene mass exceeded the MDL of 0.01 microgram in 23 soil-gas samplers, whereas toluene was detected in only 10 soil-gas samplers. Ortho-xylene was detected above the MDL in only one soil-gas sampler. The highest soil-gas mass detected for undecane, tridecane, and pentadecane was located in the northeastern corner of the 8th Street site. Chloroform mass greater than the MDL of 0.01 microgram was detected in less than one-third of the soil-gas samplers. Soil-gas masses above the MDL were identified for TPH, gasoline-related compounds, diesel-range alkanes, trimethylbenzenes, naphthalene, 2-methyl-napthalene, octane, and tetrachloroethylene for the July 2011 soil-gas survey at the Chamberlain Avenue site. All 30 of the soil-gas samplers contained TPH mass above the MDL. The highest detection of TPH mass, 426.36 micrograms, was for a soil-gas sampler located near the northern boundary of the site. Gasoline-related compounds and diesel-range alkanes were detected in multiple soil-gas samplers, and the highest detections of these compounds were located near the central part of the site near existing, nonoperational, fuel-dispensing pumps. Trimethylbenzenes were detected in less than half of the soil-gas samplers. Naphthalene soil-gas mass was detected above the MDL in 10 soil-gas samplers, whereas 2-methyl-napthalene was detected above the MDL in half of the soil-gas samplers. Octane mass was detected above the MDL in one soil-gas sampler located near the central part of the site. Tetrachloroethylene soil-gas mass was detected above the MDL in more than half of the soil-gas samplers, and the highest tetrachloroethylene soil-gas mass of 0.90 microgram was located in the northeastern part of the site. Soil-gas samplers collected at the 12th Street site during July 2011 contained soil-gas mass above the MDL for TPH, toluene, undecane, tridecane, and pentadecane (diesel-range alkanes), trichloroethylene, 1,4-dichlorobenzene, chloroform, and 1,2,4-trimethylbenzene. The highest detected TPH mass was 24.37 micrograms in a soil-gas sampler located in the northern part of the site. The highest detection of toluene soil-gas mass was from a soil-gas sampler located near the southern boundary of the site. The diesel-range alkanes were detected above the MDL in five soil-gas samplers; the highest detection of soil-gas diesel mass, 0.65 microgram, was located in the southern part of the site. Trichloroethylene and 1,4-dichlorobenzene were detected above the MDL in the northern part of the site in one soil-gas sampler that also had one of the highest detections of TPH. Chloroform was detected above the MDL in three soil-gas samplers, whereas 1,2,4-trimethylbenzene soil-gas mass was detected above the MDL in two soil-gas samplers.

  5. Effect of urbanization on the water resources of Warminster Township, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Sloto, R.A.; Davis, D.K.

    1982-01-01

    Rapid suburban development occurred in Warminster Township and the surrounding area after World War II, resulting in a large population dependent on ground water. In 1980, approximately 2.7 billion gallons of ground water was pumped by public water suppliers and government facilities. Pumping wells can cause drawdown as far as 2,500 feet undip, downdip, or along strike even if the wells do not penetrate the same strata. Pumping wells have lowered base flow; a stream-gain-and-loss study showed that water lost from Little Neshaminy Creek was about 60 percent of the water pumped from wells near the stream. Net ground-water infiltration to sewers was about 830 million gallons in 1979, a wet year, and about 250 million gallons in 1980, a dry year. Estimated water budgets for 1979 and 1980 indicate evapotranspiration can range from 20 to 26 inches per year (1.0 to 1.2 million gallons per day per square mile) and recharge can range from 8 to 18 inches per year (0.4 to 0.9 million gallons per day per square mile). In a year with average precipitation (45 inches or 2.1 million gallons per day per square mile), evapotranspiration is about 24 inches (1.1 million gallons per day per square mile). Ground-water development in the area influenced by pumping is at its practical limit for years of average recharge, but as much as 1.1 million gallons per day of additional water may be obtained by drilling and pumping wells in areas of Warminster Township not affected by pumping. The concentration of most dissolved constituents increased in water from seven wells, sampled at the onset of urbanization in 1953 and 1956 and again in 1979. Ground-water contamination by volatile organic compounds, especially trichloroethylene and tetrachloroethylene, has made water from some wells unsuitable for public supply. The concentration of lead in 26 samples of ground water ranged from 0 to 55 micrograms per liter, with a median of 17 micrograms per liter; this is above the reported national median and the median in nearby Chester County. High concentrations of sulfate and dissolved solids in ground water are probably caused by restricted gournd-water circulation and may be reduced by long-term pumping, which flushes the aquifer. Effluent from sewage treatment plants has degraded the quality of low streamflow.

  6. Interpretation of Borehole Geophysical Logs, Aquifer-Isolation Tests, and Water-Quality Data for Sites 1, 3, and 5 at the Willow Grove Naval Air Station/Joint Reserve Base, Horsham Township, Montgomery County, Pennsylvania: 2005

    USGS Publications Warehouse

    Sloto, Ronald A.

    2007-01-01

    Borehole geophysical logging, heatpulse-flowmeter measurements, borehole television surveys, and aquifer-isolation tests were conducted in 2005 at the Willow Grove Naval Air Station/Joint Reserve Base (NAS/JRB) in Horsham Township, Montgomery County, Pa. This study was done by the U.S. Geological Survey (USGS) in cooperation with the U.S. Navy in support of hydrogeological investigations to address ground-water contamination. Data collected for this study are valuable for understanding ground-water flow in the Stockton Formation at the local and regional scale. The Willow Grove NAS/JRB is underlain by the Stockton Formation, which consists of sedimentary rocks of Triassic age. The rocks of the Stockton Formation form a complex, heterogeneous aquifer with partially connected zones of high permeability. Borehole geophysical logs, heatpulse-flowmeter measurements, and borehole television surveys made in seven boreholes ranging from 70 to 350 ft deep were used to identify potential water-producing fractures and fracture zones and to select intervals for aquifer-isolation tests. An upward vertical hydraulic gradient was measured in one borehole, a downward vertical hydraulic gradient was measured in four boreholes, both an upward and a downward vertical hydraulic gradient were measured in one borehole, and no flow was measurable in one borehole. The aquifer-isolation tests isolated 30 discrete fractures in the seven boreholes for collection of depth-discrete hydraulic and water-quality data. Of the 30 fractures identified as potentially water producing, 26 fractures (87 percent) produced more than 1 gallon per minute of water. The specific capacity of the isolated intervals producing more than 1 gallon per minute ranged from 0.02 to 5.2 gallons per minute per foot. There was no relation between specific capacity and depth of the fracture. Samples for analysis for volatile organic compounds were collected from each isolated zone. Tetrachloroethylene (PCE) was the most prevalent compound at Site 1; concentrations were as great as 62 ?g/L (micrograms per liter). 1,1-dichloroethane was the most prevalent compound at Site 3; concentrations were as great as 9.3 ?g/L. Toluene was the most prevalent compound at Site 5; concentrations were as great as 77 ?g/L. For five out of the six wells (83 percent) sampled for field determinations of water-quality constituents, the interval with the lowest dissolved oxygen concentration had the highest total VOC concentration.

  7. Acoustically enhanced nonaqueous phase liquid remediation in porous media

    NASA Astrophysics Data System (ADS)

    Vogler, Eric Todd

    Groundwater contamination, caused by the presence of dense nonaqueous phase liquids (DNAPLs), remains a remediation challenge due to their low aqueous solubilities and residual phase immobility. To combat this challenge, the application of acoustic waves for remediation of water saturated porous media contaminated by DNAPL ganglia is proposed and investigated in this study. Experiments are performed to first determine the effects of acoustic waves on the transport of a conservative tracer in a water-saturated column packed with glass beads. From resulting experimental tracer data, the addition of acoustic waves, in the frequency range between 60 to 245 Hz, to a steady background fluid flow (base case) is found to enhance solute transport compared to the base case. Furthermore, the effective velocity of the solute is approximately inversely proportional to the frequency of the acoustic wave. Next, the effects of acoustic waves on the dissolution of trichloroethylene (TCE) DNAPL ganglia in a water saturated column, packed with glass beads are investigated. Acoustic waves with pressure amplitudes ranging from 0 to 1625 Pa and frequencies ranging from 0 to 285 Hz are employed to the interstitial fluid at the inlet of the packed column. Effluent dissolved TCE concentrations are observed to increase in the presence of acoustic pressure waves compared to the case where TCE dissolution without acoustic waves is monitored. The observed effluent dissolved TCE concentration increase is attributed to increased mass flux at the TCE-water interface, caused by acoustic waves. As an extension to the single component ganglia dissolution experiments, the impact of acoustic pressure waves on multicomponent DNAPL ganglia dissolution is also investigated. The multicomponent ganglia was composed of TCE and 1,1,2-trichloroethane (1,1,2-TCA) or TCE, 1,1,2-TCA, and tetrachloroethylene (PCE). Laboratory data from ganglia dissolution experiments with two and three component NAPL mixtures show that the greatest dissolution enhancement in the presence of acoustic waves is associated with the NAPL component having the smallest equilibrium aqueous solubility. Finally, square shaped acoustic waves are shown to lead to greater NAPL dissolution enhancement compared to sinusoidal and triangular acoustic waves. Finally, a pore network consisting of a monolayer of glass beads is used to investigate the effects of acoustic waves on the dissolution and mobilization of perchlorethylene (PCE) ganglia. (Abstract shortened by UMI.)

  8. Design and Operation of a Borehole Straddle Packer for Ground-Water Sampling and Hydraulic Testing of Discrete Intervals at U.S. Air Force Plant 6, Marietta, Georgia

    USGS Publications Warehouse

    Holloway, Owen G.; Waddell, Jonathan P.

    2008-01-01

    A borehole straddle packer was developed and tested by the U.S. Geological Survey to characterize the vertical distribution of contaminants, head, and hydraulic properties in open-borehole wells as part of an ongoing investigation of ground-water contamination at U.S. Air Force Plant 6 (AFP6) in Marietta, Georgia. To better understand contaminant fate and transport in a crystalline bedrock setting and to support remedial activities at AFP6, numerous wells have been constructed that include long open-hole intervals in the crystalline bedrock. These wells can include several discontinuities that produce water, which may contain contaminants. Because of the complexity of ground-water flow and contaminant movement in the crystalline bedrock, it is important to characterize the hydraulic and water-quality characteristics of discrete intervals in these wells. The straddle packer facilitates ground-water sampling and hydraulic testing of discrete intervals, and delivery of fluids including tracer suites and remedial agents into these discontinuities. The straddle packer consists of two inflatable packers, a dual-pump system, a pressure-sensing system, and an aqueous injection system. Tests were conducted to assess the accuracy of the pressure-sensing systems, and water samples were collected for analysis of volatile organic compound (VOCs) concentrations. Pressure-transducer readings matched computed water-column height, with a coefficient of determination of greater than 0.99. The straddle packer incorporates both an air-driven piston pump and a variable-frequency, electronic, submersible pump. Only slight differences were observed between VOC concentrations in samples collected using the two different types of sampling pumps during two sampling events in July and August 2005. A test conducted to assess the effect of stagnation on VOC concentrations in water trapped in the system's pump-tubing reel showed that concentrations were not affected. A comparison was conducted to assess differences between three water-sampling methods - collecting samples from the well by pumping a packer-isolated zone using a submersible pump, by using a grab sampler, and by using a passive diffusion sampler. Concentrations of tetrachloroethylene, trichloroethylene and 1,2-dichloropropane were greatest for samples collected using the submersible pump in the packed-isolated interval, suggesting that the straddle packer yielded the least dilute sample.

  9. GE/NOMADICS IN-WELL MONITORING SYSTEM FOR VERTICAL PROFILING OF DNAPL CONTAMINANTS

    SciTech Connect

    Ronald E. Shaffer; Radislav Potyralio; Joseph Salvo; Timothy Sivavec; Lloyd Salsman

    2003-04-01

    This report describes the Phase I effort to develop an Automated In Well Monitoring System (AIMS) for in situ detection of chlorinated volatile organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE) in groundwater. AIMS is composed of 3 primary components: (a) sensor probe, (b) instrument delivery system, and (c) communication/recharging station. The sensor probe utilizes an array of thickness shear mode (TSM) sensors coated with chemically-sensitive polymer films provides a low-cost, highly sensitive microsensor platform for detection and quantification. The instrument delivery system is used to position the sensor probe in 2 inch or larger groundwater monitoring wells. A communication/recharging station provides wireless battery recharging and communication to enable a fully automated system. A calibration curve for TCE in water was built using data collected in the laboratory. The detection limit of the sensor probe was 6.7 ppb ({micro}g/L) for TCE in water. A preliminary field test was conducted at a GE remediation location and a pilot field test was performed at the DOE Savannah River Site (SRS). The AIMS system was demonstrated in an uncontaminated (i.e., ''clean'') 2-inch well and in a 4-inch well containing 163.5 ppb of TCE. Repeat measurements at the two wells indicated excellent day-to-day reproducibility. Significant differences in the sensor responses were noted between the two types of wells but they did not closely match the laboratory calibration data. The robustness of the system presented numerous challenges for field work and limited the scope of the SRS pilot field test. However, the unique combination of trace detection (detection limits near the MCL, minimum concentration level) and size (operations in 2-inch or larger groundwater wells) is demonstration of the promise of this technology for long-term monitoring (LTM) applications or rapid site characterization. Using the lessons learned from the pilot field test, a number of design changes are proposed to increase the robustness of the system for extended field studies and commercialization.

  10. Final report on CCM key comparison CCM.D-K2: Comparison of liquid density standards

    NASA Astrophysics Data System (ADS)

    Bettin, Horst; Jacques, Claude; Zelenka, Zoltán; Fujii, Ken-ichi; Kuramoto, Naoki; Chang, Kyung-Ho; Lee, Yong Jae; Becerra, Luis Omar; Domostroeva, Natalia

    2013-01-01

    The results are presented of the key comparison CCM.D-K2 that covered the density measurements of four liquids: the density of water at 20 °C, of pentadecane at 15 °C, 20 °C, 40 °C and 60°C, of tetrachloroethlyene at 5 °C and 20 °C and of a viscous oil at 20 °C. Seven national metrology institutes measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards in the time interval from 27 April 2004 to 28 June 2004. Since the participants were asked not to include components for a possible drift or inhomogeneity of the liquid in their uncertainty budget, these uncertainty contributions are investigated for the final evaluation of the data. For this purpose, results of stability and homogeneity measurements of the pilot laboratory are used. The participants decided not to include a possible drift of the liquid's density since no significant drift could be detected, and the influence of the drift and its uncertainty are negligible. Similarly, the inhomogeneity of the water and pentadecane samples is not significant and has no influence on the evaluation. Thus, it was neglected. Only the inhomogeneities of tetrachloroethylene and of the viscous oil were significant. Consequently, they were included in the evaluation. With one or two exceptions, the results show good agreement among the participants. Only in the case of water are the results clearly discrepant. The key comparison reference values were calculated by the weighted mean (taking into account a small correlation between two participants) in the case of consistent results. Otherwise the Procedure B of Cox was used. The expanded uncertainties of all reference densities are below 1 × 10-5 in relative terms. This satisfies the needs of all customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database. The results can be used to link regional comparisons to this CCM key comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  11. Induced Polarization with Electromagnetic Coupling: 3D Spectral Imaging Theory, EMSP Project No. 73836

    SciTech Connect

    Morgan, F. Dale; Sogade, John

    2004-12-14

    This project was designed as a broad foundational study of spectral induced polarization (SIP) for characterization of contaminated sites. It encompassed laboratory studies of the effects of chemistry on induced polarization, development of 3D forward modeling and inversion codes, and investigations of inductive and capacitive coupling problems. In the laboratory part of the project a physico-chemical model developed in this project was used to invert laboratory IP spectra for the grain size and the effective grain size distribution of the sedimentary rocks as well as the formation factor, porosity, specific surface area, and the apparent fractal dimension. Furthermore, it was established that the IP response changed with the solution chemistry, the concentration of a given solution chemistry, valence of the constituent ions, and ionic radius. In the field part of the project, a 3D complex forward and inverse model was developed. It was used to process data acquired at two frequencies (1/16 Hz and 1/ 4Hz) in a cross-borehole configuration at the A-14 outfall area of the Savannah River Site (SRS) during March 2003 and June 2004. The chosen SRS site was contaminated with Tetrachloroethylene (TCE) and Trichloroethylene (PCE) that were disposed in this area for several decades till the 1980s. The imaginary conductivity produced from the inverted 2003 data correlated very well with the log10 (PCE) concentration derived from point sampling at 1 ft spacing in five ground-truth boreholes drilled after the data acquisition. The equivalent result for the 2004 data revealed that there were significant contaminant movements during the period March 2003 and June 2004, probably related to ground-truth activities and nearby remediation activities. Therefore SIP was successfully used to develop conceptual models of volume distributions of PCE/TCE contamination. In addition, the project developed non-polarizing electrodes that can be deployed in boreholes for years. A total of 28 of these electrodes were deployed at the SRS site in September of 2002. The project found that (1) currently available field instrumentation need to be faster by an order of magnitude for full SIP to be engaged for broadband characterization in the field, (2) some aspects of the capacitive coupling problem in borehole geometries can be solved by use of a high impedance receiver, (3) a careful investigation of ways to adequately compare inversion results to ground-truth data is warranted, (4) more laboratory studies should be directed to understand the influence of micro-organisms and long residence time of contaminants (aging) on spectral IP properties.

  12. Global Concentrations of Selected Halocarbons, 1988-1992

    NASA Astrophysics Data System (ADS)

    Wang, Jia-Lin Charlie

    During a period of 5 years, 1988 to 1992, 15 field sampling trips have been completed in an effort to continue monitoring background atmospheric concentrations of 6 man -made halocarbons, i.e., CCl_2F _2 (CFC-12), CCl_3F (CFC-11), CCl_2FCClF_2 (CFC-113), CH_3CCl _3, CCl_4, and C _2Cl_4. Approximately 70 to 90 flask air samples were collected 3 to 4 times a year from remote surface locations in the Pacific, ranging between latitudes 72^ circN and 47^circS. The samples were analyzed in the laboratory at University of California, Irvine employing cryogenic sample preconcentration, gas chromatographic separation and electron capture detection. Diluted air mixtures made from pure halocarbons were rigorously formulated to the part per trillion by volume levels (x10^{-12}) and were employed to calibrate the absolute halocarbon concentrations of a whole air sample used as a working standard in our sample analysis. The absolute calibrations performed on three chlorofluorocarbons (CFCs) yielded winter -1992 averaged global concentrations of 80, 498, and 266 pptv for CFC-11, CFC-12, and CFC-113, respectively. Among the halocarbons measured CFC-11, CFC-12, and CFC-113 have been studied in detail including the changes in their temporal trends, north-to-south gradients, rates of increase, etc., at a time when their emissions have been slowly cut back as required by the Montreal Protocol and its amendments. In general, the background concentrations of these CFCs all showed a substantial decrease in their rate of growth in the atmosphere in recent years compared to earlier years. The rates of increase for winter 1992 are 3, 9, and 2.5 pptv/yr compared to 11, 20, and 8 in 1988, for CFC-11, CFC-12, and CFC-113, respectively. Seasonal variation in global concentrations for a hydroxy-radical reactive species, tetrachloroethylene (CCl_2=CCl_2) has also been studied. This variation is driven by the abundance of tropspheric hydroxyl radicals, which is controlled by the variation of its source strength. The lifetime for CCl_2=CCl_2 has been determined to be 4-5 months based on its emission data and rate constant comparison with another hydroxyl -radical reactive species, i.e, CH_3CCl _3, with a known tropospheric lifetime of 5.7 years.

  13. Streambed-material characteristics and surface-water quality, Green Pond Brook and tributaries, Picatinny Arsenal, New Jersey, 1983-90

    USGS Publications Warehouse

    Storck, D.A.; Lacombe, Pierre

    1996-01-01

    This report presents the results of a study designed to determine whether Green Pond Brook and its tributaries contain contaminated streambed sediments and to characterize the quaity of water in the brook. Results of previous investigations at Picatinny Arsenal, Morris County, New Jersey, indicate that significant contamination of ground water, surface water, and soil is present at the arsenal. Forty-five streambed-material samples were collected for analysis to determine whether contaminants have migrated to the brook from the surrounding area. Samples were analyzed for trace elements, base/neutral- and acid-etractable compounds, insecticides, and other constituents. Results of an electromagnetic-conductivity and natural-gamma-ray survey were used to describe the distribution of particle sizes in streambed and substreambed sediments. Historical results of analyses of streambed-material and surface-water samples also are presented. Samples of streambed material from three areas in Green Pond Brook and its tributaries contained organic and (or) inorganic constituents in concentrations greater than those typically found at the arsenal. These areas are Green Pond Brook, from the area near the outflow of Picatinny Lake downstream to Farley Avenue; Bear Swamp Brook, from the area near building 241 downstream to the confluence with Green Pond Brook; and Green Pond Brook, from the open burning area downstream to the dam near building 1178. Contaminants identified include trace elements, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine insecticides. Surface water in Green Pond Brook contained several volatile organic compounds, including trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene, at maximum concen- trations of 3.8, 4.6, and 11 micrograms per liter, respectively. Volatilization is expected to remove volatile organic compounds in the steep, fast- flowing reaches of the brook. No organic or inorganic constituents were detected in surface- water samples in concentrations greater than the U.S. Environmental Protection Agency primary drinking-water regulations. Only two constituents, iron and manganese, were detected in concen- trations greater than the U.S. Environmental Protection Agency secondary drinking-water regulations.

  14. Ground-Water Levels and Water-Quality Data for Wells in the Crumpton Creek Area near Arnold Air Force Base, Tennessee, November 2001 to January 2002

    USGS Publications Warehouse

    Williams, Shannon D.

    2003-01-01

    From November 2001 to January 2002, a study of the ground-water resources in the Crumpton Creek area of Middle Tennessee was conducted to determine whether volatile organic compounds (VOCs) from Arnold Air Force Base (AAFB) have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. VOC samples were collected from private wells that were not included in previous sampling efforts conducted in the Crumpton Creek area near AAFB. Ground-water-flow directions were investigated by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 68 private wells, 82 monitoring wells, and 1 cave during the period of study. Ground-water levels were determined for 42 of the private wells and for all 82 monitoring wells. Of the 82 monitoring wells, 81 withdraw water from the Manchester aquifer and 1 well withdraws water from the overlying shallow aquifer. The Manchester aquifer wells range in depth from 20 to 150 feet. Water-level altitudes for the Manchester aquifer ranged from 956 to 1,064 feet above the National Geodetic Vertical Datum of 1929. Water levels ranged from approximately 6 feet above land surface to 94 feet below land surface. Water-quality samples were collected from all 68 private wells, 8 of the monitoring wells, and the 1 cave. Of the 55 VOCs analyzed, 42 were not detected. Thirteen VOCs were detected; however, only tetrachloroethylene (PCE), methylene chloride, and toluene were detected at concentrations equal to or above reporting levels for the analytical method used. PCE was detected in water samples from 15 private wells and was the only VOC that exceeded drinking water maximum contaminant levels for public water systems. PCE concentrations in samples from five of the wells were below the reporting level and ranged from estimated concentrations of 0.46 to 0.80 microgram per liter (?g/L). Samples from 10 wells contained concentrations equal to or greater than the analytical reporting level of 1 ?g/L for PCE. Samples from one of these wells contained PCE concentrations (12 ?g/L and 11 ?g/L) exceeding the drinking water maximum contaminant level of 5 ?g/L for PCE. The spatial distribution of PCE detections and the relative concentrations of PCE and trichloroethylene suggest that the PCE detections are associated with a small and localized ground-water contamination plume unrelated to AAFB ground-water contamination.

  15. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected VOC soil gas concentrations during ASVE. Five (5) SVE wells that were located closest to the air injection wells were used as monitoring points during the air sparging tests. The air sparging tests lasted 48 hours. Soil gas sample results indicate that sparging did not affect VOC concentrations in four of the five sparging wells, while results from one test did show an increase in soil gas concentrations.

  16. Inorganic and organic ground-water chemistry in the Canal Creek area of Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Lorah, M.M.; Vroblesky, D.A.

    1989-01-01

    Groundwater chemical data were collected from November 1986 through April 1987 in the first phase of a 5-year study to assess the possibility of groundwater contamination in the Canal Creek area of Aberdeen Proving Ground, Maryland. Water samples were collected from 87 observation wells screened in Coastal Plain sediments; 59 samples were collected from the Canal Creek aquifer, 18 from the overlying surficial aquifer, and 10 from the lower confined aquifer. Dissolved solids, chloride, iron, manganese, fluoride, mercury, and chromium are present in concentrations that exceed the Federal maximum contaminant levels for drinking water. Elevated chloride and dissolved-solids concentrations appear to be related from contaminant plumes but also could result from brackish-water intrusion. Excessive concentrations of iron and manganese were the most extensive water quality problems found among the inorganic constituents and are derived from natural dissolution of minerals and oxide coatings in the aquifer sediments. Volatile organic compounds are present in the Canal Creek and surficial aquifers, but samples from the lower confined aquifer do not show any evidence of contamination by inorganic or organic chemicals. The volatile organic contaminants detected in the groundwater and their maximum concentrations (in micrograms/L) include 1,1,2,2- tetrachloroethane (9,000); carbon tetrachloride (480); chloroform (460); 1,1,2-trichloroethane (80); 1,2-dichloroethane (990); 1,1-dichloroethane (3.1); tetrachloroethylene (100); trichloroethylene (1,800); 1,2-trans- dichloroethylene (1,200); 1,1-dichloroethylene (4.4); vinyl chloride (140); benzene (70); and chlorobenzene (39). On the basis of information on past activities in the study area, some sources of the volatile organic compounds include: (1) decontaminants and degreasers; (2) clothing-impregnating operations; (3) the manufacture of impregnite material; (4) the manufacture of tear gas; and (5) fuels used in garages and at the air-field. The high density of most of the detected organic compounds in free-product form would have aided their movement into the aquifers by vertical sinking. The outcrop area of the upper confining unit and an area cut by a paleochannel are most susceptible to contamination because a near-surface impermeable layer is not present. (USGS)

  17. Asthma symptoms in Hispanic children and daily ambient exposures to toxic and criteria air pollutants.

    PubMed Central

    Delfino, Ralph J; Gong, Henry; Linn, William S; Pellizzari, Edo D; Hu, Ye

    2003-01-01

    Although acute adverse effects on asthma have been frequently found for the U.S. Environmental Protection Agency's principal criteria air pollutants, there is little epidemiologic information on specific hydrocarbons from toxic emission sources. We conducted a panel study of 22 Hispanic children with asthma who were 10-16 years old and living in a Los Angeles community with high traffic density. Subjects filled out symptom diaries daily for up to 3 months (November 1999 through January 2000). Pollutants included ambient hourly values of ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide and 24-hr values of volatile organic compounds (VOCs), particulate matter with aerodynamic diameter < 10 microm (PM10, and elemental carbon (EC) and organic carbon (OC) PM10 fractions. Asthma symptom severity was regressed on pollutants using generalized estimating equations, and peak expiratory flow (PEF) was regressed on pollutants using mixed models. We found positive associations of symptoms with criteria air pollutants (O3, NO2, SO2, PM10), EC-OC, and VOCs (benzene, ethylbenzene, formaldehyde, acetaldehyde, acetone, 1,3-butadiene, tetrachloroethylene, toluene, m,p-xylene, and o-xylene). Selected adjusted odds ratios for bothersome or more severe asthma symptoms from interquartile range increases in pollutants were, for 1.4 ppb 8-hr NO2, 1.27 [95% confidence interval (CI), 1.05-1.54]; 1.00 ppb benzene, 1.23 (95% CI, 1.02-1.48); 3.16 ppb formaldehyde, 1.37 (95% CI, 1.04-1.80); 37 microg/m3 PM10, 1.45 (95% CI, 1.11-1.90); 2.91 microg/m3 EC, 1.85 (95% CI, 1.11-3.08); and 4.64 microg/m3 OC, 1.88 (95% CI, 1.12-3.17). Two-pollutant models of EC or OC with PM10 showed little change in odds ratios for EC (to 1.83) or OC (to 1.89), but PM10 decreased from 1.45 to 1.0. There were no significant associations with PEF. Findings support the view that air toxins in the pollutant mix from traffic and industrial sources may have adverse effects on asthma in children. PMID:12676630

  18. Activity of horseradish peroxide adsorbed on radio frequency glow discharge-treated polymers.

    PubMed

    Chen, J P; Kiaei, D; Hoffman, A S

    1993-01-01

    Horseradish peroxidase (HRP) has been used as a model enzyme in this study of its physical adsorption and residual enzyme activity on radio frequency glow discharge (RFGD)-treated polymers. The specific enzymatic activity of HRP adsorbed on different surfaces was assumed to be an indication of the extent of its conformational alterations on the surfaces. The surfaces studied were poly (ethylene terephthalate) (PET), polytetrafluoroethylene (PTFE), and tetrachloroethylene and tetrafluoroethylene glow discharge-treated PET, abbreviated as TCE/PET and TFE/PET. All surfaces were characterized by electron spectroscopy for chemical analysis (ESCA) and liquid contact angles in air. HRP adsorbs more strongly onto the two discharge-treated surfaces than onto the untreated polymers, as evidenced by the lower amount of HRP eluted by sodium dodecyl sulfate (SDS) from the treated polymers. For example, seventy percent of the HRP adsorbed on TCE/PET or TFE/PET remains on the surface after overnight elution with a 1% solution of SDS. In contrast, untreated PET and PTFE each retains only c. 20% of the absorbed enzyme. The enzymatic activity of HRP adsorbed on the different surfaces was studied using hydrogen peroxide (H2O2) as the substrate. HRP adsorbed on the higher energy surfaces, PET and TCE/PET, retains significantly more activity than the HRP adsorbed on the lower energy surfaces, PTFE and TFE/PET which appear to destroy rapidly almost all of the activity of HRP after it adsorbs. HRP adsorbed on TCE/PET is relatively more stable over time than HRP adsorbed on PET or free HRP in solution. (For example, only 45% of the specific enzymatic activity of HRP adsorbed on TCE/PET was lost after 3 h of storage in phosphate buffer at 37 degrees C, while 70% of that adsorbed on PET was lost.) In summary, when HRP is adsorbed on TCE/PET, it is very tightly bound, and yet it maintains a significant fraction of its initial specific activity and also retains this activity for 3 h in phosphate buffer at 37 degrees C. Thus, tenacious physical adsorption of proteins such as enzymes on TCE glow discharge-treated surfaces may have potential as a new method of immobilization of such molecules, for uses in biosensors, diagnostics, bioseparations, cell culture and bioreactors. PMID:8297829

  19. Bedrock geology and outcrop fracture trends in the vicinity of the Savage Municipal Well Superfund site, Milford, New Hampshire

    USGS Publications Warehouse

    Burton, William C.; Harte, Philip T.

    2013-01-01

    The Savage Municipal Well Superfund site consists of an eastward-directed plume of volatile organic compounds, principally tetrachloroethylene (PCE), in alluvium and glacial sand and gravel in the Souhegan River valley, just south of the river and about 4 kilometers west of the town of Milford, New Hampshire. Sampling of monitoring wells at the site has helped delineate the extent of the plume and has determined that some contaminant has migrated into the underlying crystalline bedrock, including bedrock north of the river within 200 meters of a nearby residential development that was constructed in 1999. Borehole geophysical logging has identified a northeast preferential trend for bedrock fractures, which may provide a pathway for the migration of contaminant under and north of the Souhegan River. The current study investigates the bedrock geologic setting for the site, including its position relative to known regional geologic structures, and compiles new strike and dip measurements of joints in exposed bedrock to determine if there are dominant trends in orientation similar to what was found in the boreholes. The site is located on the northwestern limb of a northeast-trending regional anticlinorium that is southeast of the Campbell Hill fault zone. The Campbell Hill fault zone defines the contact between granite and gneiss of the anticlinorium and granite and schist to the northwest and is locally marked by lenses of massive vein quartz, minor faults, and fracture zones that could potentially affect plume migration. The fault zone was apparently not intercepted by any of the boreholes that were drilled to delineate the contaminant plume and therefore passes to the north of the northernmost borehole in the vicinity of the new residential area. Joints measured in surface exposures indicate a strong preferred direction of strike to the north-northeast corroborating the borehole data and previous outcrop and geophysical studies. The north-northeast preferred direction matches the direction of elongation of the cone of depression formed during a pump test of the bedrock wells and could explain a potential pathway for the migration of contaminant north of the river.

  20. Dissolution Coupled Biodegradation of Pce by Inducing In-Situ Biosurfactant Production Under Anaerobic Conditions

    NASA Astrophysics Data System (ADS)

    Dominic, J.; Nambi, I. M.

    2013-12-01

    Biosurfactants have proven to enhance the bioavailability and thereby elevate the rate of degradation of Light Non Aqueous Phase Liquids (LNAPLs) such as crude oil and petroleum derivatives. In spite of their superior characteristics, use of these biomolecules for remediation of Dense Non Aqueous Phase Liquids (DNAPLs) such as chlorinated solvents is still not clearly understood. In this present study, we have investigated the fate of tetrachloroethylene (PCE) by inducing in-situ biosurfactants production, a sustainable option which hypothesizes increase in bioavailability of LNAPLs. In order to understand the effect of biosurfactants on dissolution and biodegradation under the inducement of in-situ biosurfactant production, batch experiments were conducted in pure liquid media. The individual influence of each process such as biosurfactant production, dissolution of PCE and biodegradation of PCE were studied separately for getting insights on the synergistic effect of each process on the fate of PCE. Finally the dissolution coupled biodegradation of non aqueous phase PCE was studied in conditions where biosurfactant production was induced by nitrate limitation. The effect of biosurfactants was differentiated by repeating the same experiments were the biosurfactant production was retarded. The overall effect of in-situ biosurfactant production process was evaluated by use of a mathematical model. The process of microbial growth, biosurfactant production, dissolution and biodegradation of PCE were translated as ordinary differential equations. The modelling exercise was mainly performed to get insight on the combined effects of various processes that determine the concentration of PCE in its aqueous and non-aqueous phases. Model simulated profiles of PCE with the kinetic coefficients evaluated earlier from individual experiments were compared with parameters fitted for observations in experiments with dissolution coupled biodegradation process using optimization routines. Complete disappearance of PCE from DNAPL and aqueous phase was observed in a span of 14 days in systems triggered with biosurfactant production through enhanced dissolution and biodegradation. Synergistic effect of dissolution process towards biodegradation was observed as bioavailability of PCE was increased by 3.1 times in systems with biosurfactant production. Modelling studies illustrate that biodegradation on the other hand synergistically enhanced dissolution by elevating the dissolution rates by 1.4 times. This study also suggests a mass transfer phenomenon is greatly influenced not only by surface active molecules but by microbes as well.

  1. Long-term ground penetrating radar monitoring of a small volume DNAPL release in a natural groundwater flow field.

    PubMed

    Hwang, Yong Keun; Endres, Anthony L; Piggott, Scott D; Parker, Beth L

    2008-04-01

    An earlier field experiment at Canadian Forces Base Borden by Brewster and Annan [Geophysics 59 (1994) 1211] clearly demonstrated the capability of ground penetrating radar (GPR) reflection profiling to detect and monitor the formation of DNAPL layers in the subsurface. Their experiment involved a large volume release (770 L) of tetrachloroethylene into a portion of the sand aquifer that was hydraulically isolated from groundwater flow by sheet pile walls. In this study, we evaluated the ability of GPR profiling to detect and monitor much smaller volume releases (50 L). No subsurface confining structure was used in this experiment; hence, the DNAPL impacted zone was subjected to the natural groundwater flow regime. This condition allowed us to geophysically monitor the DNAPL mass loss over a 66 month period. Reflectivity variations on the GPR profiles were used to infer the presence and evolution of the solvent layers. GPR imaging found significant reflectivity increases due to solvent layer formation during the two week period immediately after the release. These results demonstrated the capacity of GPR profiling for the detection and monitoring of lesser volume DNAPL releases that are more representative of small-scale industrial spills. The GPR imaged solvent layers subsequently reduced in both areal extent and reflectivity after 29 months and almost completely disappeared by the end of the 66 month monitoring period. Total DNAPL mass estimates based on GPR profiling data indicated that the solvent mass was reduced to 34%-36% of its maximum value after 29 months; only 4%-9% of the solvent mass remained in the study area after 66 months. These results are consistent with independent hydrogeological estimates of remaining DNAPL mass based on the downgradient monitoring of the dissolved solvent phase. Hence, we have concluded that the long-term GPR reflectivity changes of the DNAPL layers are likely the result from the dissolution of chlorinated solvents residing in those layers. The long-term monitoring results demonstrated that GPR profiling is a promising non-invasive method for use at DNAPL contaminated sites in sandy aquifers where temporal information about immiscible contaminant mass depletion due to either natural flow or remediation is needed. However, our results also indicated that the GPR signature of older DNAPL impacted zones may not differ greatly from the uncontaminated background if significant mass reduction due to dissolution has occurred. PMID:18258330

  2. Dispersive liquid-liquid microextraction combined with semi-automated in-syringe back extraction as a new approach for the sample preparation of ionizable organic compounds prior to liquid chromatography.

    PubMed

    Melwanki, Mahaveer B; Fuh, Ming-Ren

    2008-07-11

    Dispersive liquid-liquid microextraction (DLLME) followed by a newly designed semi-automated in-syringe back extraction technique has been developed as an extraction methodology for the extraction of polar organic compounds prior to liquid chromatography (LC) measurement. The method is based on the formation of tiny droplets of the extractant in the sample solution using water-immiscible organic solvent (extractant) dissolved in a water-miscible organic dispersive solvent. Extraction of the analytes from aqueous sample into the dispersed organic droplets took place. The extracting organic phase was separated by centrifuging and the sedimented phase was withdrawn into a syringe. Then in-syringe back extraction was utilized to extract the analytes into an aqueous solution prior to LC analysis. Clenbuterol (CB), a basic organic compound used as a model, was extracted from a basified aqueous sample using 25 microL tetrachloroethylene (TCE, extraction solvent) dissolved in 500 microL acetone (as a dispersive solvent). After separation of the organic extracting phase by centrifuging, CB enriched in TCE phase was back extracted into 10 microL of 1% aqueous formic acid (FA) within the syringe. Back extraction was facilitated by repeatedly moving the plunger back and forth within the barrel of syringe, assisted by a syringe pump. Due to the plunger movement, a thin organic film is formed on the inner layer of the syringe that comes in contact with the acidic aqueous phase. Here, CB, a basic analyte, will be protonated and back extracted into FA. Various parameters affecting the extraction efficiency, viz., choice of extraction and dispersive solvent, salt effect, speed of syringe pump, back extraction time period, effect of concentration of base and acid, were evaluated. Under optimum conditions, precision, linearity (correlation coefficient, r(2)=0.9966 over the concentration range of 10-1000 ng mL(-1) CB), detection limit (4.9 ng mL(-1)), enrichment factor (175), relative recovery (97%) had been obtained. The applicability of this newly developed method was investigated for the analysis of CB in the water samples from river, lake and stream water. PMID:18513730

  3. Global concentrations of selected halocarbons, 1988-1992

    SciTech Connect

    Wang, J.L.C.

    1993-12-31

    During a period of 5 years, 1988 to 1992, 15 field sampling trips have been completed in an effort to continue monitoring background atmospheric concentration of 6 man-made halocarbons, i.e., CCl{sub 2}F{sub 2} (CFC-12), CCl{sub 3}F (CFC-11), CCl{sub 2}FCClF{sub 2} (CFC-113), CH{sub 3}CCl{sub 3}, CCl{sub 4}, and C{sub 2}Cl{sub 4}. Approximately 70 to 90 flask air samples were collected 3 to 4 times a year from remote surface locations in the Pacific, ranging between latitudes 72{degrees}N and 47{degrees}S. The samples were analyzed in the laboratory at University of California, Irvine employing cryogenic sample preconcentration, gas chromatographic separation and electron capture detection. Diluted air mixtures made from pure halocarbons were rigorously formulated to the part per trillion by volume levels (x10{sup {minus}12}) and were employed to calibrate the absolute halocarbon concentrations of a whole air sample used as a working standard in the sample analysis. The absolute calibrations performed on three chlorofluorocarbons (CFCs) yielded winter-1992 averaged global concentrations of 80, 498, and 266 pptv for CFC-11, CFC-12, and CFC-113, respectively. Among the halocarbons measured CFC-11, CFC-12, and CFC-113 have been studied in detail including the changes in their temporal trends, north-to-south gradients, rates of increase, etc, at a time when their emissions have been slowly cut back as required by the Montreal Protocol and its amendments. In general, the background concentrations of these CFCs all showed a substantial decrease in their rate of growth in the atmosphere in recent years compared to earlier years. The rates of increase for winter 1992 are 3, 9, and 2.5 pptv/yr compared to 11, 20, and 8 in 1988, for CFC-11, CFC-12, and CFC-113, respectively. Seasonal variation in global concentrations for a hydroxy-radical reactive species, tetrachloroethylene (CCl{sub 2}{double_bond}CCl{sub 2}) has also been studied.

  4. Geochemical, isotopic, and dissolved gas characteristics of groundwater in a fractured crystalline-rock aquifer, Savage Municipal Well Superfund site, Milford, New Hampshire, 2011

    USGS Publications Warehouse

    Harte, Philip T.

    2013-01-01

    Tetrachloroethylene (PCE), a volatile organic compound, was detected in groundwater from deep (more than (>) 300 feet (ft) below land surface) fractures in monitoring wells tapping a crystalline-rock aquifer beneath operable unit 1 (OU1) of the Savage Municipal Well Superfund site (Weston, Inc., 2010). Operable units define remedial areas of contaminant concern. PCE contamination within the fractured-rock aquifer has been designated as a separate operable unit, operable unit 3 (OU3; Weston, Inc., 2010). PCE contamination was previously detected in the overlying glacial sand and gravel deposits and basal till, hereafter termed the Milford-Souhegan glacial-drift (MSGD) aquifer (Harte, 2004, 2006). Operable units 1 and 2 encompass areas within the MSGD aquifer, whereas the extent of the underlying OU3 has yet to be defined. The primary original source of contamination has been identified as a former manufacturing facility—the OK Tool manufacturing facility; hence OU1 sometimes has been referred to as the OK Tool Source Area (New Hampshire Department of Environmental Services, undated). A residential neighborhood of 30 to 40 houses is located in close proximity (one-quarter of a mile) from the PCE-contaminated monitoring wells. Each house has its own water-supply well installed in similar rocks as those of the monitoring wells, as indicated by the New Hampshire State geologic map (Lyons and others, 1997). An investigation was initiated in 2010 by the U.S. Environmental Protection Agency (USEPA) region 1, and the New Hampshire Department of Environmental Services (NHDES) to assess the potential for PCE transport from known contaminant locations (monitoring wells) to the residential wells. The U.S. Geological Survey (USGS) and the NHDES entered into a cooperative agreement in 2011 to assist in the evaluation of PCE transport in the fractured-rock aquifer. Periodic sampling over the last decade by the USEPA and NHDES has yet to detect PCE in groundwater from the residential-supply wells (as of 2012). However, part of assessing the potential for PCE transport involves understanding the origin of the groundwater in the monitoring and residential wells. One of the tools in delineating the movement of groundwater to wells, particularly in complex, highly heterogeneous fractured-rock aquifers, is the understanding of the geochemical and isotopic composition of groundwater (Lipfert and Reeve, 2004; Harte and others, 2012). This report summarizes findings from analyses of geochemical, isotopic, and dissolved gas characteristics of groundwater. Samples of groundwater were collected in 2011 from monitoring wells and nearby residential-supply wells in proximity to OU1.

  5. A modified light transmission visualization method for DNAPL saturation measurements in 2-D models

    NASA Astrophysics Data System (ADS)

    Bob, Mustafa M.; Brooks, Michael C.; Mravik, Susan C.; Wood, A. Lynn

    2008-05-01

    In this research, a light transmission visualization (LTV) method was used to quantify dense non-aqueous phase liquids (DNAPL) saturation in two-dimensional (2-D), two fluid phase systems. The method is an expansion of earlier LTV methods and takes into account both absorption and refraction light theories. Based on this method, DNAPL and water saturations can rapidly be obtained point wise across sand-packed 2-D flow chambers without the need to develop a calibration curve. A single point calibration step is, however, needed when dyed DNAPL is used to account for the change in the transmission factor at the dyed DNAPL-water interface. The method was applied to measure, for the first time, undyed DNAPL saturation in small 2-D chambers. Known amounts of DNAPL, modeled by tetrachloroethylene (PCE), were added to the chamber and these amounts were compared to results obtained by this LTV method. Strong correlation existed between results obtained based on this method and the known PCE amounts with an R2 value of 0.993. Similar experiments conducted using dyed PCE showed a stronger correlation between results obtained by this LTV method and the known amounts of dyed PCE added to the chamber with an R2 value of 0.999. The method was also used to measure dyed PCE saturation in a large 2-D model following sparging experiments. Results obtained from image analyses following each sparging event were compared to results obtained by two independent techniques, namely gas chromatography-mass spectrometry (GC/MS) analyses and carbon column extraction. There was a good agreement between the results obtained by this LTV method and those obtained by the two independent techniques when experiments were carried out under stable light source conditions and errors in mass balance were minor. The method presented here can be expanded to measure fluid contents in three fluid phase systems and provide a non-destructive, non-intrusive tool to investigate changes in DNAPL architecture and flow characteristics in laboratory experiments.

  6. Nonaqueous Phase Liquid Dissolution in Porous Media: Multi-Scale Effects of Multi-Component Dissolution Kinetics on Cleanup Time

    SciTech Connect

    McNab, W; Ezzedine, S; Detwiler, R

    2007-02-26

    Industrial organic solvents such as trichloroethylene (TCE) and tetrachloroethylene (PCE) constitute a principal class of groundwater contaminants. Cleanup of groundwater plume source areas associated with these compounds is problematic, in part, because the compounds often exist in the subsurface as dense nonaqueous phase liquids (DNAPLs). Ganglia (or 'blobs') of DNAPL serve as persistent sources of contaminants that are difficult to locate and remediate (e.g. Fenwick and Blunt, 1998). Current understanding of the physical and chemical processes associated with dissolution of DNAPLs in the subsurface is incomplete and yet is critical for evaluating long-term behavior of contaminant migration, groundwater cleanup, and the efficacy of source area cleanup technologies. As such, a goal of this project has been to contribute to this critical understanding by investigating the multi-phase, multi-component physics of DNAPL dissolution using state-of-the-art experimental and computational techniques. Through this research, we have explored efficient and accurate conceptual and numerical models for source area contaminant transport that can be used to better inform the modeling of source area contaminants, including those at the LLNL Superfund sites, to re-evaluate existing remediation technologies, and to inspire or develop new remediation strategies. The problem of DNAPL dissolution in natural porous media must be viewed in the context of several scales (Khachikian and Harmon, 2000), including the microscopic level at which capillary forces, viscous forces, and gravity/buoyancy forces are manifested at the scale of individual pores (Wilson and Conrad, 1984; Chatzis et al., 1988), the mesoscale where dissolution rates are strongly influenced by the local hydrodynamics, and the field-scale. Historically, the physico-chemical processes associated with DNAPL dissolution have been addressed through the use of lumped mass transfer coefficients which attempt to quantify the dissolution rate in response to local dissolved-phase concentrations distributed across the source area using a volume-averaging approach (Figure 1). The fundamental problem with the lumped mass transfer parameter is that its value is typically derived empirically through column-scale experiments that combine the effects of pore-scale flow, diffusion, and pore-scale geometry in a manner that does not provide a robust theoretical basis for upscaling. In our view, upscaling processes from the pore-scale to the field-scale requires new computational approaches (Held and Celia, 2001) that are directly linked to experimental studies of dissolution at the pore scale. As such, our investigation has been multi-pronged, combining theory, experiments, numerical modeling, new data analysis approaches, and a synthesis of previous studies (e.g. Glass et al, 2001; Keller et al., 2002) aimed at quantifying how the mechanisms controlling dissolution at the pore-scale control the long-term dissolution of source areas at larger scales.

  7. Interpretation of borehole geophysical logs, aquifer-isolation tests, and water quality, supply wells 1 and 2, Willow Grove Naval Air Station/Joint Reserve Base, Horsham Township, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.; Goode, Daniel J.; Frasch, Steven M.

    2002-01-01

    Ground water pumped from supply wells 1 and 2 on the Willow Grove Naval Air Station/Joint Reserve Base (NAS/JRB) provides water for use at the base, including potable water for drinking. The supply wells have been contaminated by volatile organic compounds (VOC?s), particularly trichloroethylene (TCE) and tetrachloroethylene (PCE), and the water is treated to remove the VOC?s. The Willow Grove NAS/JRB and surrounding area are underlain by sedimentary rocks of the Triassic-age Stockton Formation, which form a complex, heterogeneous aquifer. The ground-water-flow system for the supply wells was characterized by use of borehole geophysical logs and heatpulse-flowmeter measurements. The heatpulse-flowmeter measurements showed upward and downward borehole flow under nonpumping conditions in both wells. The hydraulic and chemical properties of discrete water-bearing fractures in the supply wells were characterized by isolating each water-bearing fracture with straddle packers. Eight fractures in supply well 1 and five fractures in supply well 2 were selected for testing on the basis of the borehole geophysical logs and borehole television surveys. Water samples were collected from each isolated fracture and analyzed for VOC?s and inorganic constituents. Fractures at 50?59, 79?80, 196, 124?152, 182, 241, 256, and 350?354 ft btoc (feet below top of casing) were isolated in supply well 1. Specific capacities ranged from 0.26 to 5.7 (gal/min)/ft (gallons per minute per foot) of drawdown. The highest specific capacity was for the fracture isolated at 179.8?188 ft btoc. Specific capacity and depth of fracture were not related in either supply well. The highest concentrations of PCE were in water samples collected from fractures isolated at 236.8?245 and 249.8?258 ft btoc, which are hydraulically connected. The concentration of PCE generally increased with depth to a maximum of 39 mg/L (micrograms per liter) at a depth of 249.8? 258 ft btoc and then decreased to 21 mg/L at a depth of 345.3?389 ft btoc. Fractures at 68?74, 115, 162, 182, 205, and 314 ft btoc were isolated in supply well 2. Specific capacities ranged from 0.08 to less than 2.9 (gal/ min)/ft. The highest specific capacity was for the fracture isolated at 157?165.2 ft btoc. Concentrations of detected VOC?s in water samples were 3.6 mg/L or less. Lithologic units penetrated by both supply wells were determined by correlating naturalgamma and single-point-resistance borehole geophysical logs. All lithologic units are not continuous water-bearing units because water-bearing fractures are not necessarily present in the same lithologic units in each well. Although the wells penetrate the same lithologic units, the lithologic location of only three water-bearing fractures are common to both wells. The same lithologic unit may have different hydraulic properties in each well. A regional ground-water divide is southeast of the supply wells. From this divide, ground water flows northwest toward Park Creek, a tributary to Little Neshaminy Creek. Potentiometric-surface maps were prepared from water levels measured in shallow and deep wells. For both depth intervals, the direction of ground-water flow is toward the northwest. For most well clusters, the vertical head gradient is downward from the shallow to the deeper part of the aquifer. Pumping of the supply wells at times can cause the vertical flow direction to reverse.

  8. Development and evaluation of a harmonized physiologically based pharmacokinetic (PBPK) model for perchloroethylene toxicokinetics in mice, rats, and humans

    SciTech Connect

    Chiu, Weihsueh A., E-mail: chiu.weihsueh@epa.gov [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington, DC 20460 (United States); Ginsberg, Gary L., E-mail: gary.ginsberg@ct.gov [Connecticut Department of Public Health, Hartford, CT 06106 (United States)

    2011-06-15

    This article reports on the development of a 'harmonized' PBPK model for the toxicokinetics of perchloroethylene (tetrachloroethylene or perc) in mice, rats, and humans that includes both oxidation and glutathione (GSH) conjugation of perc, the internal kinetics of the oxidative metabolite trichloroacetic acid (TCA), and the urinary excretion kinetics of the GSH conjugation metabolites N-Acetylated trichlorovinyl cysteine and dichloroacetic acid. The model utilizes a wider range of in vitro and in vivo data than any previous analysis alone, with in vitro data used for initial, or 'baseline,' parameter estimates, and in vivo datasets separated into those used for 'calibration' and those used for 'evaluation.' Parameter calibration utilizes a limited Bayesian analysis involving flat priors and making inferences only using posterior modes obtained via Markov chain Monte Carlo (MCMC). As expected, the major route of elimination of absorbed perc is predicted to be exhalation as parent compound, with metabolism accounting for less than 20% of intake except in the case of mice exposed orally, in which metabolism is predicted to be slightly over 50% at lower exposures. In all three species, the concentration of perc in blood, the extent of perc oxidation, and the amount of TCA production is well-estimated, with residual uncertainties of {approx} 2-fold. However, the resulting range of estimates for the amount of GSH conjugation is quite wide in humans ({approx} 3000-fold) and mice ({approx} 60-fold). While even high-end estimates of GSH conjugation in mice are lower than estimates of oxidation, in humans the estimated rates range from much lower to much higher than rates for perc oxidation. It is unclear to what extent this range reflects uncertainty, variability, or a combination. Importantly, by separating total perc metabolism into separate oxidative and conjugative pathways, an approach also recommended in a recent National Research Council review, this analysis reconciles the disparity between those previously published PBPK models that concluded low perc metabolism in humans and those that predicted high perc metabolism in humans. In essence, both conclusions are consistent with the data if augmented with some additional qualifications: in humans, oxidative metabolism is low, while GSH conjugation metabolism may be high or low, with uncertainty and/or interindividual variability spanning three orders of magnitude. More direct data on the internal kinetics of perc GSH conjugation, such as trichlorovinyl glutathione or tricholorvinyl cysteine in blood and/or tissues, would be needed to better characterize the uncertainty and variability in GSH conjugation in humans. - Research Highlights: >We analyze perchloroethylene (perc) toxicokinetics with a physiological model. >Results from previous analyses lumping metabolic pathways are inconsistent. >Separately tracking oxidation and conjugation pathways reconciles these results. >Available data are adequate for predicting perc blood levels and oxidation by P450. >High uncertainty remains for human conjugation of perc with glutathione.

  9. Ground-water system, estimation of aquifer hydraulic properties, and effects of pumping on ground-water flow in Triassic sedimentary rocks in and near Lansdale, Pennsylvania

    USGS Publications Warehouse

    Senior, Lisa A.; Goode, Daniel J.

    1999-01-01

    Ground water in Triassic-age sedimentary fractured-rock aquifers in the area of Lansdale, Pa., is used as drinking water and for industrial supply. In 1979, ground water in the Lansdale area was found to be contaminated with trichloroethylene, tetrachloroethylene, and other man-made organic compounds, and in 1989, the area was placed on the U.S. Environmental Protection Agency's (USEPA) National Priority List as the North Penn Area 6 site. To assist the USEPA in the hydrogeological assessment of the site, the U.S. Geological Survey began a study in 1995 to describe the ground-water system and to determine the effects of changes in the well pumping patterns on the direction of ground-water flow in the Lansdale area. This determination is based on hydrologic and geophysical data collected from 1995-98 and on results of the simulation of the regional ground-water-flow system by use of a numerical model.Correlation of natural-gamma logs indicate that the sedimentary rock beds strike generally northeast and dip at angles less than 30 degrees to the northwest. The ground-water system is confined or semi-confined, even at shallow depths; depth to bedrock commonly is less than 20 feet (6 meters); and depth to water commonly is about 15 to 60 feet (5 to 18 meters) below land surface. Single-well, aquifer-interval-isolation (packer) tests indicate that vertical permeability of the sedimentary rocks is low. Multiple-well aquifer tests indicate that the system is heterogeneous and that flow appears primarily in discrete zones parallel to bedding. Preferred horizontal flow along strike was not observed in the aquifer tests for wells open to the pumped interval. Water levels in wells that are open to the pumped interval, as projected along the dipping stratigraphy, are drawn down more than water levels in wells that do not intersect the pumped interval. A regional potentiometric map based on measured water levels indicates that ground water flows from Lansdale towards discharge areas in three drainages, the Wissahickon, Towamencin, and Neshaminy Creeks.Ground-water flow was simulated for different pumping patterns representing past and current conditions. The three-dimensional numerical flow model (MODFLOW) was automatically calibrated by use of a parameter estimation program (MODFLOWP). Steady-state conditions were assumed for the calibration period of 1996. Model calibration indicates that estimated recharge is 8.2 inches (208 millimeters) and the regional anisotropy ratio for the sedimentary-rock aquifer is about 11 to 1, with permeability greatest along strike. The regional anisotropy is caused by up- and down-dip termination of high-permeability bed-oriented features, which were not explicitly simulated in the regional-scale model. The calibrated flow model was used to compare flow directions and capture zones in Lansdale for conditions corresponding to relatively high pumping rates in 1994 and to lower pumping rates in 1997. Comparison of the 1994 and 1997 simulations indicates that wells pumped at the lower 1997 rates captured less ground water from known sites of contamination than wells pumped at the 1994 rates. Ground-water flow rates away from Lansdale increased as pumpage decreased in 1997.A preliminary evaluation of the relation between ground-water chemistry and conditions favorable for the degradation of chlorinated solvents was based on measurements of dissolved-oxygen concentration and other chemical constituents in water samples from 92 wells. About 18 percent of the samples contained less than or equal to 5 milligrams per liter dissolved oxygen, a concentration that indicates reducing conditions favorable for degradation of chlorinated solvents.

  10. Injection of Emulsified Vegetable Oil for Long-Term Bioreduction of Uranium

    NASA Astrophysics Data System (ADS)

    Brooks, S. C.; Watson, D. B.; Schadt, C. W.; Jardine, P. M.; Gihring, T. M.; Zhang, G.; Mehlhorn, T.; Lowe, K.; Phillips, J.; Earles, J.; Wu, W.; Criddle, C. S.; Kemner, K. M.; Boyanov, M.

    2011-12-01

    In situ bioremediation of a uranium and nitrate-contaminated aquifer with the slow-release electron donor, emulsified vegetable oil (EVO), was tested at the US DOE Subsurface Biogeochemical Research Program (SBR) Integrated Field Research Challenge (IFRC) site, in Oak Ridge, TN. The EVO injection took place in Area 2 of the IFRC located about 300 m downgradient of the former S-3 disposal ponds. Liquid wastes, disposed in the ponds from 1951 to 1983, were primarily composed of nitric acid, plating wastes containing various metals (Cr, Ni) radionuclides (U, Tc), inorganics (nitrate, sulfate) and organic contaminants (tetrachloroethylene, acetone). Prior pond closure in 1987, large volumes of waste fluids migrated into the subsurface, down Bear Creek Valley and into Bear Creek. Contaminants detected at Area 2 were transported through a high permeability gravelly fill that is considered a preferred transport pathway for U to Bear Creek. Groundwater in the gravelly fill is contaminated with U (1-3 mg/L), sulfate (95-130 mg/L), and nitrate (20-40 mg/L) and 500 mg/kg or higher U has been detected on the solid phase of the fill material. The objective of this study is to investigate the feasibility and long-term sustainability of U(VI) reduction and immobilization, and nitrate degradation in the high permeability, high flow gravel fill using EVO as the electron donor. A one-time EVO injection was conducted over a 2 hour period in the highly permeable gravel (hydraulic conductivity 0.08 cm/sec) in the well instrumented IFRC Area 2 field plot. Extensive monitoring of geochemical parameters, dissolved gases and microbial populations were conducted during the test. A bromide tracer test was conducted prior to the injection of the EVO to assess transport pathways and rates. Geochemical analysis of site groundwater demonstrated the sequential bioreduction of oxygen, nitrate, Mn(IV), Fe(III) and sulfate. Transient accumulation of acetate was observed as an intermediate in the oil degradation. Reduction and removal of U and nitrate from groundwater was observed in all wells in hydraulic connection to the injection wells after 2-4 weeks. U concentrations in groundwater were reduced to below 30 ppb (US EPA drinking water standard) at some well locations and nitrate was reduced to below detectable levels. Rebound of U in groundwater was observed together with the rebound of sulfate concentrations as the EVO was consumed. The flux of U and nitrate contamination from groundwater to the surface water receptor (Bear Creek) was significantly reduced by the EVO injection over a one year period. Uranium (VI) reduction to U(IV) in the field tests was confirmed by X-ray absorption near-edge spectroscopy (XANES) analysis. The reduced U(IV) was determined by X-ray absorption fine structure (XAFS) to be in an Fe-U complex, not uraninite. The activities of major Fe(III)- and sulfate-reducing bacteria with U(VI)-reducing capability as well as methanogens was stimulated after injection of the oil.

  11. Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

    USGS Publications Warehouse

    Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler

    2005-01-01

    The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water. Trihalomethanes (THMs) were detected less frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples. The THMs that were detected in the Mojave River Basin were detected more frequently in the floodplain aquifer than in the regional aquifer and sewered subset. Solvents were detected more frequently in the Mojave River samples than in the Antelope Valley samples. In the Mojave River Basin samples, solvents were detected less frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Benzene, toluene, ethylbenzene and xylene (BTEX) were not detected in either study area. Methyl tert-butyl ether (MTBE) was detected in one sample from both the Mojave River and Antelope Valley Basins. The most frequently detected compound (detected in more than 10 percent of the wells) in the Mojave River Basin was chloroform. The two most frequently detected compounds in the Antelope Valley Basin were chloroform and tetrachloroethylene (PCE). In the Mojave River Basin, aquifer type and land use within 1,640 ft (500 m) of the well head were not statistically correlated with the number of VOCs detected, although VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Depth to the top of the perforations was an explanatory factor for the number of VOCs detected in the Mojave River Basin; the detection frequency was greater for shallow wells than for deep wells. In the Antelope Valley Basin, neither aquifer type, depth to the top of the perforations, nor land use within 1,640 ft of the well head were explanatory factors for the number of VOCs detected. Although aquifer type and depth to top of the perforations did explain the presence of tritium in the Mojave River Basin, land use within 1,640 ft of the well head was not a statistically significant explanatory factor for the presence of tritium in this basin. Aquifer type, depth to the top of the perfora

  12. Hydrogeology, Chemical Characteristics, and Transport Processes in the Zone of Contribution of a Public-Supply Well in York, Nebraska

    USGS Publications Warehouse

    Landon, Matthew K.; Clark, Brian R.; McMahon, Peter B.; McGuire, Virginia L.; Turco, Michael J.

    2008-01-01

    In 2001, the U.S. Geological Survey, as part of the National Water Quality Assessment (NAWQA) Program, initiated a topical study of Transport of Anthropogenic and Natural Contaminants (TANC) to PSW (public-supply wells). Local-scale and regional-scale TANC study areas were delineated within selected NAWQA study units for intensive study of processes effecting transport of contaminants to PSWs. This report describes results from a local-scale TANC study area at York, Nebraska, within the High Plains aquifer, including the hydrogeology and geochemistry of a 108-square-kilometer study area that contains the zone of contribution to a PSW selected for study (study PSW), and describes factors controlling the transport of selected anthropogenic and natural contaminants to PSWs. Within the local-scale TANC study area, the High Plains aquifer is approximately 75 m (meter) thick, and includes an unconfined aquifer, an upper confining unit, an upper confined aquifer, and a lower confining unit with lower confined sand lenses (units below the upper confining unit are referred to as confined aquifers) in unconsolidated alluvial and glacial deposits overlain by loess and underlain by Cretaceous shale. From northwest to southeast, land use in the local-scale TANC study area changes from predominantly irrigated agricultural land to residential and commercial land in the small community of York (population approximately 8,100). For the purposes of comparing water chemistry, wells were classified by degree of aquifer confinement (unconfined and confined), depth in the unconfined aquifer (shallow and deep), land use (urban and agricultural), and extent of mixing in wells in the confined aquifer with water from the unconfined aquifer (mixed and unmixed). Oxygen (delta 18O) and hydrogen (delta D) stable isotopic values indicated a clear isotopic contrast between shallow wells in the unconfined aquifer (hereinafter, unconfined shallow wells) and most monitoring wells in the confined aquifers (hereinafter, confined unmixed wells). Delta 18O and delta D values for a minority of wells in the confined aquifers were intermediate between those for the unconfined shallow wells and those for the confined unmixed wells. These intermediate values were consistent with mixing of water from unconfined and confined aquifers (hereinafter, confined mixed wells). Oxidation-reduction conditions were primarily oxic in the unconfined aquifer and variably reducing in the confined aquifers. Trace amounts of volatile organic compounds (VOC), particularly tetrachloroethylene (PCE) and trichloroethylene (TCE), were widely detected in unconfined shallow urban wells and indicated the presence of young urban recharge waters in most confined mixed wells. The presence of degradation products of agricultural pesticides (acetochlor and alachlor) in some confined mixed wells suggests that some fraction of the water in these wells also was the result of recharge in agricultural areas. In the unconfined aquifer, age-tracer data (chlorofluorocarbon and sulfur hexafluoride data, and tritium to helium-3 ratios) fit a piston-flow model, with apparent recharge ages ranging from 7 to 48 years and generally increasing with depth. Age-tracer data for the confined aquifers were consistent with mixing of 'old' water, not containing modern tracers recharged in the last 60 years, and exponentially-mixed 'young' water with modern tracers. Confined unmixed wells contained less than (=) 97% of old water. Confined mixed wells contained >30% young water and mean ages ranged from 12 to 14 years. Median concentrations of nitrate (as nitrogen, hereinafter, nitrate-N) were 17.3 and 16.0 mg/L (milligram per liter) in unconfined shallow urban and agricultural wells, respectively, indicating a range of likely nitrate sources. Septic systems are most numerous near the edge of the urban area and appear to be

  13. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    SciTech Connect

    Peace, Gerald L.; Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2005-11-01

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses. At least one-hundred realizations were simulated for each scenario defined in the performance assessment. Conservative values and assumptions were used to define values and distributions of uncertain input parameters when site data were not available. Results showed that exposure to tritium via the air pathway exceeded the regulatory metric of 10 mrem/year in about 2% of the simulated realizations when the receptor was located at the MWL (continuously exposed to the air directly above the MWL). Simulations showed that peak radon gas fluxes exceeded the design standard of 20 pCi/m{sup 2}/s in about 3% of the realizations if up to 1% of the containers of sealed radium-226 sources were assumed to completely degrade in the future. If up to 100% of the containers of radium-226 sources were assumed to completely degrade, 30% of the realizations yielded radon surface fluxes that exceeded the design standard. For the groundwater pathway, simulations showed that none of the radionuclides or heavy metals (lead and cadmium) reached the groundwater during the 1,000-year evaluation period. Tetrachloroethylene (PCE) was used as a proxy for other VOCs because of its mobility and potential to exceed maximum contaminant levels in the groundwater relative to other VOCs. Simulations showed that PCE reached the groundwater, but only 1% of the realizations yielded aquifer concentrations that exceeded the regulatory metric of 5 {micro}g/L. Based on these results, monitoring triggers have been proposed for the air, surface soil, vadose zone, and groundwater at the MWL. Specific triggers include numerical thresholds for radon concentrations in the air, tritium concentrations in surface soil, infiltration through the vadose zone, and uranium and select VOC concentrations in groundwater. The proposed triggers are based on U.S. Environmental Protection Agency and Department of Energy regulatory standards. If a trigger is exceeded, then a trigger evaluation process will be initiated which will allow sufficient data to be collected to assess trends and recommend corrective actions, if necessary.

  14. Hanford Site Groundwater Monitoring for Fiscal Year 1998

    SciTech Connect

    Hartman, M.J. [and others

    1999-03-24

    This report presents the results of groundwater and vadose-zone monitoring and remediation for fiscal year (FY) 1998 on the Word Site, Washington. Soil-vapor extraction in the 200-West Area removed 777 kg of carbon tetrachloride in FY 1998, for a total of 75,490 kg removed since remediation began in 1992. Spectral gamma logging and evaluation of historical gross gamma logs near tank farms and liquid-disposal sites in the 200 Areas provided information on movement of contaminants in the vadose zone. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1997 and June 1998. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of technetium-99, uranium, strontium-90, and carbon-14 also exceeded drinking water standards in smaller plumes. Plutonium and cesium-137 exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in U.S. Department of Energy Order 5400.5 were exceeded for tritium, uranium, strontium-90, and plutonium in small plumes or single wells. One well completed in the basalt-confined aquifer beneath the 200-East Area exceeded the drinking water standard for technetium-99. Nitrate is the most extensive chemical contaminant. Carbon tetrachloride, chloroform, chromium, cis-l, Z-dichloroethylene, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Cyanide concentrations were elevated in one area but were below the maximum contaminant level. Tetrachloroethylene exceeded its maximum contaminant level in several wells in the 300 Area for the first time since the 1980s. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels in filtered samples from numerous wells; they are believed to represent natural components of groundwater. Resource Conservation and Recovery Act of 1976 groundwater monitoring continued at 25 waste management areas during FY 1998: 17 under detection programs and data indicate that they are not adversely affecting groundwater, 6 under interim-status groundwater-quality-assessment programs to assess possible contamination, and 2 under final-status corrective-action programs. Groundwater remediation in the 100 Areas continued to reduce the amount of strontium-90 (100-N) and chromium (100-K, D, and H) reaching the Columbia River. Two systems in the 200-West Area operated to prevent the spread of carbon tetrachloride and technetide uranium plumes. Groundwater monitoring continued at these sites and at other sites where there is no active remediation. A three-dimensional, numerical groundwater model was applied to simulate radionuclide movement from sources in the 200 Areas following site closure in 2050. Contaminants will continue to move toward the southeast and north (through Gable Gap), but the areas with levels exceeding drinking water standards will diminish.

  15. Surface-water-quality assessment of the upper Illinois River Basin in Illinois, Indiana, and Wisconsin; pesticides and other synthetic organic compounds in water, sediment, and biota, 1975-90

    USGS Publications Warehouse

    Sullivan, Daniel J.; Stinson, Troy W.; Crawford, J. Kent; Schmidt, Arthur R.; Colman, John A.

    1998-01-01

    The distribution of pesticides and other synthetic organic compounds in water, sediment, and biota in the upper Illinois River Basin in Illinois, Indiana, and Wisconsin was examined from 1987 through 1990 as part of the pilot National Water-Quality Assesssment Program conducted by the U.S. Geological Survey. Historical data for water and sediment collected from 1975 through 1986 were similar to data collected from 1987 through 1990. Some compounds were detected in concentrations that exceed U.S. Environmental Protection Agency water-quality criteria. Results from pesticide sampling at four stations in 1988 and 1989 identified several agricultural pesticides that were detected more frequently and at higher concentrations in urban areas than in agricultural areas. Results from herbicide sampling at 17 stations in the Kankakee and Iroquois River Basins in 1990 indicated that atrazine concentrations exceeded the U.S. Environmental Protection Agency's maximum contaminant level for drinking water during runoff periods. Results from sampling for volatile and semivolatile organic compounds in water indicate that, with one exception, all stations at which more than one compound was detected were within 2 miles downstream from the nearest point source. Detections at two stations in the Chicago urban area accounted for 37 percent of the total number of detections. Concentrations of tetrachloroethylene, trichloroethylene, and 1,2-dichlorethane from stations in the Des Plaines River Basin exceeded the U.S. Environmental Protection Agency's maximum contaminant level for drinking water in one and two samples from the two stations in the Chicago area. Phenols and pentachlorophenols were detected most frequently in the Des Plaines River Basin where point-source discharges were common. Phenol concentrations were significantly different among the Des Plaines, Kankakee, and Fox River Basins. Phenols and pentachlorophenols never exceeded the general use and secondary contact standards. Results from a 1989 synoptic survey of semivolatile organic compounds in sediment indicate that these compounds were detected most frequently at sites in the Chicago urban area. Of the 17 stations at which 10 or more compounds were detected, 14 were located in the Des Plaines River subbasin, and 1 was on the Illinois River mainstem. As was the case with organic compounds in water, each of these sites was located within 2 miles downstream from point sources. Biota samples were collected and analyzed for organochlorines and polynuclear aromatic hydrocarbons in 1989 and 1990. The most commonly detected compound in both years was p,p'-DDE. National Academy of Science recommendations for chlordane and dieldrin for protection of predators were exceeded in 19 and 10 samples, respectively, when the 1989 and 1990 data were combined. In the nine fish-fillet samples collected in 1989, concentrations exceeded U.S. Environmental Protection Agency fish-tissue criteria in nine fillets for p,p'-DDE and five fillets for dieldrin.

  16. Polymer coated gold nanoparticles for tracing the mobility of engineered nanoparticles in the subsurface

    NASA Astrophysics Data System (ADS)

    Uthuppu, Basil; Sidelmann Fjordbøge, Annika; Caspersen, Eva; Broholm, Mette Martina; Havsteen Jakobsen, Mogens

    2014-05-01

    Nanoparticles (NPs) are manufactured for their specific properties providing possibilities for new and improved products and applications. The use of engineered nanoparticles (ENPs) has therefore brought significant innovation and advances to society, including benefits for human health and the environment. At the same time, little is known about the potential risk associated with the inevitable release of these new materials to the environment, and their new properties are poorly understood . Suspensions of ENPs are not very stable, as they tend to aggregate thereby losing their properties as single particles. Coatings, including a large variety of natural and synthetic polymers, are used to enhance the colloid stability in high concentrations . However, increasing the stability of these materials may lead to unintended effects, such as enhancing their mobility in surface water and groundwater leading to inadvertent impacts on aquatic ecosystems and human health. Detection of ENPs in natural water systems, however, has proved very challenging. Hence, there is a need for tracing of ENP behaviour in the environment. We suggest a possibility of introducing inert gold NPs with the same mobility as the reactive NPs, as tracer particles. Colloidal gold has been of great interest for centuries due to its vibrant colors produced by the interaction with visible light. The unusual optical-electronic properties, high chemical stability and relatively low toxicity have made them the model system of choice in this context. Also, the natural occurrence of these particles in the proposed environment is very rare. Laboratory based experiments conducted in sand columns show that stable aqueous suspensions of gold NPs coated with amphiphilic block co polymers (PVP-VA and PVA-COOH) are extremely mobile (retardation factors of 1.0-1.2) with high recovery values (50-95 %). The specific retardation and recovery depends on the coating type, concentration and grafting method. The NPs also show significant partitioning to organic phases such as tetrachloroethylene (PCE) and trichloroethylene (TCE), which are considered as potential ground water pollutants accumulated in the subsurface as DNAPLs (dense non-aqueous phase liquids). Being a noble metal, nanogold is to be detected by nondestructive optical methods at a concentration of at least 1000 fold lower than ENPs. Using conventional spectrophotometric technique equipped with liquid waveguide capillary cell (LWCC), nanogold is detected at very low concentration range (1 ppm - 62.5 ppb). Compared to uncoated particles, surface modified nanogold with polymers retains the plasmonic peaks at 520 nm when diluted with artificial ground water. Acknowledgement: The low level detection of nanogold using LWCC was done at the department of nuclear and quantum engineering, KAIST (Korea Advance Institute of Science and Technology), 291 Daehak-ro, (373-1, Guseong-dong), Yuseong-gu, Daejeon 305-701, Republic of KOREA. We acknowledge Prof. Woojin Lee, Prof. Jong-Il Yun, Kim A Young and Tae Hyeong Kim for the same.

  17. Effects of a remedial system and its operation on volatile organic compound-contaminated ground water, Operable Unit 1, Savage Municipal Well Superfund Site, Milford, New Hampshire, 1998-2004

    USGS Publications Warehouse

    Harte, Philip T.

    2006-01-01

    The Savage Municipal Well Superfund site in the Town of Milford, N.H., is underlain by a 0.5-square mile plume of volatile organic compounds (VOCs), mostly tetrachloroethylene (PCE). The plume occurs mostly within a highly transmissive sand and gravel layer, but also extends into underlying till and bedrock. The plume has been divided into two areas called Operable Unit 1 (OU1), which contains the primary source area, and Operable Unit 2 (OU2), which is defined as the extended plume area. PCE concentrations in excess of 100,000 parts per billion (ppb) had been detected in the OU1 area in 1995, indicating a likely Dense Non-Aqueous Phase Liquid (DNAPL) source. In the fall of 1998, the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA) installed a remedial system in OU1 to contain and capture the dissolved VOC plume. The OU1 remedial system includes a low-permeability barrier wall that encircles the highest detected concentrations of PCE, and a series of injection and extraction wells to contain and remove contaminants. The barrier wall likely penetrates the full thickness of the sand and gravel; in most places, it also penetrates the full thickness of the underlying basal till and sits atop bedrock. Remedial injection and extraction wells have been operating since the spring of 1999 and include a series of interior (inside the barrier wall) injection and extractions wells and exterior (outside the barrier wall) injection and extraction wells. A recharge gallery outside the barrier wall receives the bulk of the treated water and reinjects it into the shallow aquifer. From 1998 to 2004, PCE concentrations decreased by an average of 80 percent at most wells outside the barrier wall. This decrease indicates (1) the barrier wall and interior extraction effectively contained high PCE concentrations inside the wall, (2) other sources of PCE did not appear to be outside of the wall, and (3) ambient ground-water flow in conjunction with the exterior remedial wells effectively remediated most of the dissolved PCE plume outside the wall. The overburden at middle depths (40 to 70 ft below land surface) downgradient from exterior extraction wells showed relatively slow decreases in PCE concentrations compared to other areas outside the barrier wall. Numerical simulation shows extraction caused the formation of a small downgradient slow-velocity zone. Because the ambient ground-water velocities are high (approximately 1 foot per day), temporary termination of extraction at the exterior wells may increase dilution downgradient from the exterior extraction wells. Extraction can also be optimized on the basis of seasonal hydrologic conditions to facilitate exterior well capture from upgradient areas outside of the barrier wall where PCE concentrations are highest. Reductions in concentrations of PCE inside the barrier wall from 1998 to 2003 were minimal near suspected source areas, indicating that the operation of interior remedial wells had not been effective in remediating dissolved PCE or the DNAPL source. Capture of the dissolved PCE plume within the barrier wall by interior extraction wells could be enhanced if operation (injection rates) increased at underutilized interior injection wells, thereby increasing hydraulic gradients.

  18. Hydrostratigraphic Mapping of the Milford-Souhegan Glacial Drift Aquifer, and Effects of Hydrostratigraphy on Transport of PCE, Operable Unit 1, Savage Superfund Site, Milford, New Hampshire

    USGS Publications Warehouse

    Harte, Philip T.

    2010-01-01

    The Savage Municipal Well Superfund site in the Town of Milford, New Hampshire, was underlain by a 0.5-square mile plume (as mapped in 1994) of volatile organic compounds (VOCs), most of which consisted of tetrachloroethylene (PCE). The plume occurs mostly within highly transmissive stratified-drift deposits but also extends into underlying till and bedrock. The plume has been divided into two areas called Operable Unit 1 (OU1), which contains the primary source area, and Operable Unit 2 (OU2), which is defined as the extended plume area outside of OU1. The OU1 remedial system includes a low-permeability barrier wall that encircles the highest detected concentrations of PCE and a series of injection and extraction wells to contain and remove contaminants. The barrier wall likely penetrates the full thickness of the sand and gravel; in many places, it also penetrates the full thickness of the underlying basal till and sits atop bedrock. From 1998 to 2004, PCE concentrations decreased by an average of 80 percent at most wells outside the barrier wall. However, inside the barrier, PCE concentrations greater than 10,000 micrograms per liter (ug/L) still exist (2008). The remediation of these areas of recalcitrant PCE presents challenges to successful remediation. The U.S. Geological Survey (USGS), in cooperation with the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA), Region 1, is studying the solute transport of VOCs (primarily PCE) in contaminated groundwater in the unconsolidated sediments (overburden) of the Savage site and specifically assisting in the evaluation of the effectiveness of remedial operations in the OU1 area. As part of this effort, the USGS analyzed the subsurface stratigraphy to help understand hydrostratigraphic controls on remediation. A combination of lithologic, borehole natural gamma-ray and electromagnetic (EM) induction logging, and test drilling has identified 11 primary hydrostratigraphic units in OU1. These 11 units consist of several well-sorted sandy layers with some gravel that are separated by poorly sorted cobble layers with a fine-grained matrix. Collectively these units represent glacial sediments deposited by localized ice-margin fluctuations. For the most part, the units are semi-planar, particularly the cobble units, and truncated by an undulating bedrock surface. The lowermost unit is a basal till that ranges in thickness from zero to greater than 10 feet and mantles the bedrock surface. The 11 units have different lithologic and hydraulic characteristics. The hydraulic conductivity of the well-sorted sand and gravel units is typically greater than the conductivity of the poorly sorted cobble units and the basal till. The hydraulic conductivity ranges from 5 to greater than 500 feet per day. Lateral and vertical variation in lithology and hydraulic conductivity are inferred by variations in borehole natural gamma-ray counts and estimates of hydraulic conductivity. The comparison of hydrostratigraphic units with the spatial distribution of PCE concentrations suggests that solute transport away from source areas is primarily lateral within the permeable sandy units in the middle to lower parts of the aquifer. Along the centerline of the interior barrier area, highest PCE concentrations are in the sandy units to the east of suspected source areas.

  19. Final Technical Report: Effects of Impurities on Fuel Cell Performance and Durability

    SciTech Connect

    James G. Goodwin, Jr.; Hector Colon-Mercado; Kitiya Hongsirikarn; and Jack Z. Zhang

    2011-11-11

    The main objectives of this project were to investigate the effect of a series of potential impurities on fuel cell operation and on the particular components of the fuel cell MEA, to propose (where possible) mechanism(s) by which these impurities affected fuel cell performance, and to suggest strategies for minimizing these impurity effects. The negative effect on Pt/C was to decrease hydrogen surface coverage and hydrogen activation at fuel cell conditions. The negative effect on Nafion components was to decrease proton conductivity, primarily by replacing/reacting with the protons on the Bronsted acid sites of the Nafion. Even though already well known as fuel cell poisons, the effects of CO and NH3 were studied in great detail early on in the project in order to develop methodology for evaluating poisoning effects in general, to help establish reproducibility of results among a number of laboratories in the U.S. investigating impurity effects, and to help establish lower limit standards for impurities during hydrogen production for fuel cell utilization. New methodologies developed included (1) a means to measure hydrogen surface concentration on the Pt catalyst (HDSAP) before and after exposure to impurities, (2) a way to predict conductivity of a Nafion membranes exposed to impurities using a characteristic acid catalyzed reaction (methanol esterification of acetic acid), and, more importantly, (3) application of the latter technique to predict conductivity on Nafion in the catalyst layer of the MEA. H2-D2 exchange was found to be suitable for predicting hydrogen activation of Pt catalysts. The Nafion (ca. 30 wt%) on the Pt/C catalyst resides primarily on the external surface of the C support where it blocks significant numbers of micropores, but only partially blocks the pore openings of the meso- and macro-pores wherein lie the small Pt particles (crystallites). For this reason, even with 30 wt% Nafion on the Pt/C, few Pt sites are blocked and, hence, are accessible for hydrogen activation. Of the impurities studied, CO, NH3, perchloroethylene (also known as tetrachloroethylene), tetrahydrofuran, diborane, and metal cations had significant negative effects on the components in a fuel cell. While CO has no effect on the Nafion, it significantly poisons the Pt catalyst by adsorbing and blocking hydrogen activation. The effect can be reversed with time once the flow of CO is stopped. NH3 has no effect on the Pt catalyst at fuel cell conditions; it poisons the proton sites on Nafion (by forming NH4+ cations), decreasing drastically the proton conductivity of Nafion. This poisoning can slowly be reversed once the flow of NH3 is stopped. Perchloroethylene has a major effect on fuel cell performance. Since it has little/no effect on Nafion conductivity, its poisoning effect is on the Pt catalyst. However, this effect takes place primarily for the Pt catalyst at the cathode, since the presence of oxygen is very important for this poisoning effect. Tetrahydrofuran was shown not to impact Nafion conductivity; however, it does affect fuel cell performance. Therefore, its primary effect is on the Pt catalyst. The effect of THF on fuel cell performance is reversible. Diborane also can significant affect fuel cell performance. This effect is reversible once diborane is removed from the inlet streams. H2O2 is not an impurity usually present in the hydrogen or oxygen streams to a fuel cell. However, it is generated during fuel cell operation. The presence of Fe cations in the Nafion due to system corrosion and/or arising from MEA production act to catalyze the severe degradation of the Nafion by H2O2. Finally, the presence of metal cation impurities (Na+, Ca 2+, Fe3+) in Nafion from MEA preparation or from corrosion significantly impacts its proton conductivity due to replacement of proton sites. This effect is not reversible. Hydrocarbons, such as ethylene, might be expected to affect Pt or Nafion but do not at a typical fuel cell temperature of 80oC. In the presence of large quantities of hydrogen on the anode side, ethylene i

  20. Application of health-based screening levels to ground-water quality data in a state-scale pilot effort

    USGS Publications Warehouse

    Toccalino, Patricia L.; Norman, Julia E.; Phillips, Robyn H.; Kauffman, Leon J.; Stackelberg, Paul E.; Nowell, Lisa H.; Krietzman, Sandra J.; Post, Gloria B.

    2004-01-01

    A state-scale pilot effort was conducted to evaluate a Health-Based Screening Level (HBSL) approach developed for communicating findings from the U.S. Geological Survey (USGS) National Water-Quality Assessment Program in a human-health context. Many aquifers sampled by USGS are used as drinking-water sources, and water-quality conditions historically have been assessed by comparing measured contaminant concentrations to established drinking-water standards and guidelines. Because drinking-water standards and guidelines do not exist for many analyzed contaminants, HBSL values were developed collaboratively by the USGS, U.S. Environmental Protection Agency (USEPA), New Jersey Department of Environmental Protection, and Oregon Health & Science University, using USEPA toxicity values and USEPA Office of Water methodologies. The main objective of this report is to demonstrate the use of HBSL approach as a tool for communicating water-quality data in a human-health context by conducting a retrospective analysis of ground-water quality data from New Jersey. Another important objective is to provide guidance on the use and interpretation of HBSL values and other human-health benchmarks in the analyses of water-quality data in a human-health context. Ground-water samples collected during 1996-98 from 30 public-supply, 82 domestic, and 108 monitoring wells were analyzed for 97 pesticides and 85 volatile organic compounds (VOCs). The occurrence of individual pesticides and VOCs was evaluated in a human-health context by calculating Benchmark Quotients (BQs), defined as ratios of measured concentrations of regulated compounds (that is, compounds with Federal or state drinking-water standards) to Maximum Contaminant Level (MCL) values and ratios of measured concentrations of unregulated compounds to HBSL values. Contaminants were identified as being of potential human-health concern if maximum detected concentrations were within a factor of 10 of the associated MCL or HBSL (that is, maximum BQ value (BQmax) greater than or equal to 0.1) in any well type (public supply, domestic, monitoring). Most (57 of 77) pesticides and VOCs with human-health benchmarks were detected at concentrations well below these levels (BQmax less than 0.1) for all three well types; however, BQmax values ranged from 0.1 to 3,000 for 6 pesticides and 14 VOCs. Of these 20 contaminants, one pesticide (dieldrin) and three VOCs (1,2-dibromoethane, tetrachloroethylene, and trichloroethylene) both (1) were measured at concentrations that met or exceeded MCL or HBSL values, and (2) were detected in more than 10 percent of samples collected from raw ground water used as sources of drinking water (public-supply and (or) domestic wells) and, therefore, are particularly relevant to human health. The occurrence of multiple pesticides and VOCs in individual wells also was evaluated in a human-health context because at least 53 different contaminants were detected in each of the three well types. To assess the relative human-health importance of the occurrence of multiple contaminants in different wells, the BQ values for all contaminants in a given well were summed. The median ratio of the maximum BQ to the sum of all BQ values for each well ranged from 0.83 to 0.93 for all well types, indicating that the maximum BQ makes up the majority of the sum for most wells. Maximum and summed BQ values were statistically greater for individual public-supply wells than for individual domestic and monitoring wells. The HBSL approach is an effective tool for placing water-quality data in a human-health context. For 79 of the 182 compounds analyzed in this study, no USEPA drinking-water standards or guidelines exist, but new HBSL values were calculated for 39 of these 79 compounds. The new HBSL values increased the number of detected pesticides and VOCs with human-health benchmarks from 65 to 77 (of 97 detected compounds), thereby expanding the basis for interpreting contaminant-occu

  1. Changes in Groundwater Flow and Volatile Organic Compound Concentrations at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1993-2009

    USGS Publications Warehouse

    Sloto, Ronald A.

    2010-01-01

    The 38-acre Fischer and Porter Company Superfund Site is in Warminster Township, Bucks County, Pa. Historically, as part of the manufacturing process, trichloroethylene (TCE) degreasers were used for parts cleaning. In 1979, the Bucks County Health Department detected TCE and other volatile organic compounds (VOCs) in water from the Fischer and Porter on-site supply wells and nearby public-supply wells. The Fischer and Porter Site was designated as a Superfund Site and placed on the National Priorities List in September 1983. A 1984 Record of Decision for the site required the Fischer and Porter Company to pump and treat groundwater contaminated by VOCs from three on-site wells at a combined rate of 75 gallons per minute to contain groundwater contamination on the property. Additionally, the Record of Decision recognized the need for treatment of the water from two nearby privately owned supply wells operated by the Warminster Heights Home Ownership Association. In 2004, the Warminster Heights Home Ownership Association sold its water distribution system, and both wells were taken out of service. The report describes changes in groundwater levels and contaminant concentrations and migration caused by the shutdown of the Warminster Heights supply wells and presents a delineation of the off-site groundwater-contamination plume. The U.S. Geological Survey (USGS) conducted this study (2006-09) in cooperation with the U.S. Environmental Protection Agency (USEPA). The Fischer and Porter Site and surrounding area are underlain by sedimentary rocks of the Stockton Formation of Late Triassic age. The rocks are chiefly interbedded arkosic sandstone and siltstone. The Stockton aquifer system is comprised of a series of gently dipping lithologic units with different hydraulic properties. A three-dimensional lithostratigraphic model was developed for the site on the basis of rock cores and borehole geophysical logs. The model was simplified by combining individual lithologic units into generalized units representing upward fining sedimentary cycles capped by a siltstone bed. These cycles were labeled units 1 through 8 and are called stratigraphic units in this report. Groundwater in the unweathered zone mainly moves through a network of interconnecting secondary openings--bedding-plane fractures and joints. Groundwater generally is unconfined in the shallower part of the aquifer and confined or semiconfined in the deeper part of the aquifer. The migration of VOCs from the Fischer and Porter Site source area is influenced by geologic and hydrologic controls. The hydrologic controls have changed with time. Stratigraphic units 2 and 3 crop out beneath the former Fischer and Porter plant. VOCs originating at the plant source area entered these stratigraphic units and moved downdip to the northwest. When the wells at and in the vicinity of the site were initially sampled in 1979-80, three public-supply wells (BK-366, BK-367, MG-946) and three industrial-supply wells (BK-368, BK-370, and BK-371) were pumping. Groundwater contaminated with VOCs flowed downdip and then northeast along strike toward well BK-366, downdip toward well BK-368, and downdip and then west along strike toward well MG-946. The long axis of the TCE plume is oriented about N. 18? W. in the direction of dip. In 1979-80, the leading edge of the plume was about 3,500 feet wide. With the cessation of pumping of the supply wells in 2004, the size of the plume has decreased. In 2007-09, the plume was approximately 2,000 feet long and 2,000 feet wide at the leading edge. On the western side of the site, TCE and tetrachloroethylene (PCE) appear to be moving downdip though stratigraphic unit 3. The downdip extent of TCE and PCE migration extended approximately 550 feet off-site to the northwest and 750 feet off-site to the north. TCE concentrations in water samples from wells at the western site boundary increased from 1996 to 2007. On the northern side of the site, TCE and P

  2. Hydrogeologic framework, ground-water quality, and simulation of ground-water flow at the Fair Lawn Well Field Superfund site, Bergen County, New Jersey

    USGS Publications Warehouse

    Lewis-Brown, Jean C.; Rice, Donald E.; Rosman, Robert; Smith, Nicholas P.

    2005-01-01

    Production wells in the Westmoreland well field, Fair Lawn, Bergen County, New Jersey (the 'Fair Lawn well field Superfund site'), are contaminated with volatile organic compounds, particularly trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane. In 1983, the U.S. Environmental Protection Agency (USEPA) placed the Westmoreland well field on its National Priority List of Superfund sites. In an effort to determine ground-water flow directions, contaminant-plume boundaries, and contributing areas to production wells in Fair Lawn, and to evaluate the effect of present pump-and-treat systems on flowpaths of contaminated ground water, the U.S. Geological Survey (USGS), in cooperation with the USEPA, developed a conceptual hydrogeologic framework and ground-water flow model of the study area. MODFLOW-2000, the USGS three-dimensional finite-difference model, was used to delineate contributing areas to production wells in Fair Lawn and to compute flowpaths of contaminated ground water from three potential contaminant sources to the Westmoreland well field. Straddle-packer tests were used to determine the hydrologic framework of, distribution of contaminants in, and hydrologic properties of water-bearing and confining units that make up the fractured-rock aquifer underlying the study area. The study area consists of about 15 square miles in and near Fair Lawn. The area is underlain by 6 to 100 feet of glacial deposits and alluvium that, in turn, are underlain by the Passaic Formation. In the study area, the Passaic Formation consists of brownish-red pebble conglomerate, medium- to coarse-grained feldspathic sandstone, and micaceous siltstone. The bedrock strata strike N. 9o E. and dip 6.5o to the northwest. The bedrock consists of alternating layers of densely fractured rocks and sparsely fractured rocks, forming a fractured-rock aquifer. Ground-water flow in the fractured-rock aquifer is anisotropic as a result of the interlayering of dipping water-bearing and confining units. Wells of similar depth aligned along the strike of the bedding intersect the same water-bearing units, but wells aligned along the dip of the bedding may intersect different water-bearing units. Consequently, wells aligned along strike are in greater hydraulic connection than wells aligned along dip. The Borough of Fair Lawn pumps approximately 770 million gallons per year from 13 production wells. Hydrographs from six observation wells ranging in depth from 162 to 505 feet in Fair Lawn show that water levels in much of the study area are affected by pumping. Straddle packers were used to isolate discrete intervals within six open-hole observation wells owned by the Fair Lawn Water Department. Transmissivity, water-quality, and static-water-level data were obtained from the isolated intervals. Measured transmissivity ranged from near 0 to 8,900 feet squared per day. The broad range in measured transmissivity is a result of the heterogeneity of the fractured-rock aquifer. Eight water-bearing units and eight confining units were identified in the study area on the basis of transmissivity. The water-bearing units range in thickness from 21 to 95 feet; the mean thickness is 50 feet. The confining units range in thickness from 22 to 248 feet; the mean thickness is 83 feet. Water-level and water-quality data indicate effective separation of water-bearing units by the confining units. Water-quality samples were collected from the six observation wells at 16 depth intervals isolated by the straddle packers in 2000 and 2001. Concentrations of volatile organic compounds generally were low in samples from four of the wells, but were higher in samples from a well in Fair Lawn Industrial Park and in a well in the Westmoreland well field. The digital ground-water flow model was used to simulate steady-state scenarios representing conditions in the study area in 1991 and 2000. These years were chosen because during the intervening period,

  3. NTP technical report on the toxicity studies of a Chemical Mixture of 25 Groundwater Contaminants Administered in Drinking Water to F344/N Rats and B6C3F(1) Mice.

    PubMed

    Yang, R.

    1993-08-01

    Toxicity studies were performed with a chemically defined mixture of 25 groundwater contaminants, using dose levels considered to have environmental relevance. The mixture contained 19 organic compounds and six metals (shown below); the selection of these compounds was based primarily on the frequency of their occurrence in United States Environmental Protection Agency surveys of groundwater contamination in the vicinity of hazardous waste disposal sites. This report focuses primarily on 26-week drinking water toxicity studies with male and female F344/N rats and B6C3F(1) mice. The endpoints evaluated included histopathology, clinical pathology, neurobehavioral studies, and reproductive toxicity. Additional studies using this same chemical mixture are briefly reviewed in this report and include an evaluation of spermatogenesis in B6C3F(1) mice exposed to the chemical mixture for 13 weeks, a continuous breeding study with Sprague-Dawley rats and CD-1(R) Swiss mice, studies of myelotoxicity in B6C3F(1) mice exposed to the chemical mixture for up to 31.5 weeks, studies of immunosuppression in B6C3F(1) mice exposed for up to 13 weeks, in vitro mutagenicity assays in Salmonella typhimurium and Escherichia coli, and measures of genetic damage in bone marrow and peripheral blood of F344/N rats and B6C3F(1) mice in 2-week drinking water studies. In a 26-week drinking water study in which rats were administered the chemical mixture at composite contaminant concentrations of 0, 11, 38, 113, or 378 ppm, no deaths occurred and the body weight gain of high-dose males was slightly less than that of the controls. Water consumption decreased with dose and was 24% to 28% less than that of the controls at the highest concentration. Changes in organ weights occurred primarily in high-dose rats and included increased absolute and relative liver and kidney weights in females, increased relative kidney weight in males, and decreased absolute and relative thymus weights in males and females. Hematologic assessments indicated that rats receiving 378 ppm developed a microcytic anemia consistent with that accompanying iron depletion. Multiple foci of inflammation occurred in the liver of exposed rats. In high-dose females, these liver lesions were especially prominent and included bile duct and oval cell hyperplasia. Inflammation also occurred in the mesenteric lymph nodes, the adrenal gland, and the spleen. The amount of hemosiderin in the spleens of rats receiving the higher concentrations of the chemical mixture was less than normal. Components of a chemical mixture of 25 groundwater contaminants include acetone, aroclor 1260, arsenic, benzene, cadmium, carbon tetrachloride, chlorobenzene, chloroform, chromium, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-trans-dichloroethylene, di(2-ethylhexyl) phthalate, ethylbenzene, lead, mercury, methylene chloride, nickel, phenol, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, xylenes. In a 26-week study in which mice were exposed to the chemical mixture at concentrations of 0, 11, 38, 113, and 378 ppm in drinking water, there were no clear adverse effects noted in survival, weight gain, clinical pathology parameters, or histopathologic evaluations. Water consumption decreased with increasing dose, and water consumption by high-dose mice was approximately 40% less than that by the controls. In neurobehavioral assessments, no clear treatment-related effects were observed in measures of forelimb and hindlimb grip strength, hindlimb footsplay, motor activity, response to a thermal stimulus, or startle response in rats or mice evaluated at 6-week intervals throughout the 26- week drinking water studies. There were no effects on sperm morphology or motility or on estrous cycle length in rats or mice receiving the chemical mixture during the 26-week studies. Sperm concentration was decreased in F(1) CD-1(R) Swiss mice during continuous breeding studies, although there were no clear adverse effects on the fertility of Sprague-Dawley rats or CD-1(R) Swiss mice in th