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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

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 ...

3

A freshwater anaerobe coupling acetate oxidation to tetrachloroethylene dehalogenation.  

PubMed Central

Strain TT4B has been isolated from anaerobic sediments known to be contaminated with a variety of organic solvents. It is a gram-negative, rod-shaped bacterium and grew anaerobically with acetate as the electron donor and tetrachloroethylene as the electron acceptor in a mineral medium. cis-Dichloroethylene was the halogenated product. This strain did not grow fermentatively and used only acetate or pyruvate as electron donors. Tetrachloroethylene and trichloroethylene were used as electron acceptors, as were ferric nitriloacetate and fumarate. Nitrogen and sulfur oxyanions were not able to substitute as the electron acceptor for this organism. Modest growth occurred in a two-phase system with 1 ml of hexadecane containing 50 to 200 mM tetrachloroethylene (aqueous concentrations, 25 to 100 microM) and 10 ml of anaerobic mineral solution with Na2S as the reducing agent. Growth was completely inhibited at tetrachloroethylene levels above 100 microM. PMID:8900001

Krumholz, L R; Sharp, R; Fishbain, S S

1996-01-01

4

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. ...

5

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 ...

6

Human Health Effects of Tetrachloroethylene: Key Findings and Scientific Issues  

PubMed Central

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

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

7

Immunotoxicity and hematotoxicity induced by tetrachloroethylene in egyptian dry cleaning workers.  

PubMed

The immune and hematological systems can be a target for environmental contaminants with potential adverse effects, so the purpose of this study is to provide documentation on immunotoxicity and hematotoxicity of tetrachloroethylene, which is widely used in dry cleaning in Egypt. This study was carried out on 80 adult males. Subjects designated as controls (n = 40) were healthy persons and others were tetrachloroethylene-exposed dry-cleaning workers (n = 40). The controls and tetrachloroethylene-exposed workers were then divided into four equal groups (20 individuals/group): group I, control group never smoking; group II, smoking control group; and groups III and IV, tetrachloroethylene-exposed nonsmoking and smoking workers, respectively. Blood level of tetrachloroethylene, complete blood count, immunoglobulins (IgA, IgM, IgG, and IgE), the total numbers of white blood cells (WBC), and leukocyte differential counts, as well as interferon gamma (IFN-gamma) and interleukin-4 (IL-4), were measured. The immunotoxicity of tetrachloroethylene appeared in the form of an increase in serum immunoglobulin E in nonsmoking and smoking tetrachloroethylene-exposed workers, while the serum immunoglobulins A, M, and G levels showed no significant change in all studied groups. In addition, our results demonstrated a significant increase in white cell count, lymphocytes, natural killer (NK; CD3+CD16CD56+) cells, and B (CD19+) lymphocytes. The increase in WBC and lymphocytes may be attributed to allergic reaction. Moreover, serum and lymphocytic interlukin-4 levels were significantly increased in nonsmoking and smoking tetrachloroethylene-exposed workers. Tetrachloroethylene exposure is associated with immunotoxicity, which may lead to the augmentation of allergic diseases or appearance of autoimmune reaction. PMID:20044880

Emara, Ashraf M; Abo El-Noor, Mona M; Hassan, Neven A; Wagih, Ayman A

2010-02-01

8

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...

9

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...

10

Factors influencing tetrachloroethylene concentrations in residences above dry-cleaning establishments  

SciTech Connect

Indoor air quality has been increasingly recognized as a significant public health problem. Proximity to industrial or commercial sources contributes to contamination in homes. Air sampling was conducted at 12 residences in 8 buildings that housed dry cleaners and 6 residential control sites. The authors found that concentrations of tetrachloroethylene, a dry-cleaning solvent, were elevated significantly in residences located in buildings that also housed dry-cleaning establishments relative to their concentrations in control residences. Tetrachloroethylene concentrations remained elevated when the cleaners were closed on weekends. The authors verified that colorimetric detector tubes were a useful screening tool for residences. Also identified were factors that could affect tetrachloroethylene concentrations. The use of exhaust fans and the implementation of required inspection and maintenance requirements by dry cleaners were associated significantly with reduced tetrachloroethylene concentrations in residences. In all cases, tetrachloroethylene concentrations exceeded minimal risk levels posited by the Agency for Toxic Substances Disease Registry for chronic exposure to tetrachloroethylene. Residents who live in buildings that house dry cleaners may be exposed at concentrations that are of public health concern. Measures that might reduce this exposure were also identified.

Garetano, G.; Gochfeld, M.

2000-02-01

11

Indoor tetrachloroethylene levels and determinants in Paris dwellings.  

PubMed

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

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

2013-01-01

12

Electronic transitions in cis- and trans-dichloroethylenes and tetrachloroethylene  

NASA Astrophysics Data System (ADS)

Electronic structures of trans- and cis-dichloroethylenes and tetrachloroethylene were studied using symmetry-adapted cluster configuration interaction theory. Basis sets up to the aug-cc-pVTZ of Dunning, Jr., augmented with appropriate Rydberg functions were used for the calculations. The results derived in the present study show good agreement with the available experimental values. In all cases, the main bright excitation was the ? ??? transition. The other vertical excitations, ? ???, n ???, and n ???, which have not been studied before, were also investigated. First Rydberg series involving transitions from the ? orbitals to one 3s, three 3p, and five 3d orbitals were identified clearly. Several new assignments and reassignments of features in the experimental spectra were suggested. Contrary to earlier prediction, two n-? ? states, along with a ?-? ? state in the dichloroethylenes, were calculated to be located above the main ?-? ? state. Accordingly, crossing between both the n-? ? states with the bright ?-? ? state is highly likely, unlike conclusions made in the earlier studies. This indicates that the photodissociation mechanism proposed by the earlier calculations warrants revision. Several low-lying triplet excited states were also studied. Electronic spectra of trans-1-chloro-2-fluoroethylene and cis-1-chloro-2-fluoroethylene were also calculated. The ? ??? transitions of these haloethylenes are compared and interpreted in terms of the inductive and resonance effects.

Arulmozhiraja, Sundaram; Ehara, Masahiro; Nakatsuji, Hiroshi

2008-11-01

13

Electronic transitions in cis- and trans-dichloroethylenes and tetrachloroethylene.  

PubMed

Electronic structures of trans- and cis-dichloroethylenes and tetrachloroethylene were studied using symmetry-adapted cluster configuration interaction theory. Basis sets up to the aug-cc-pVTZ of Dunning, Jr., augmented with appropriate Rydberg functions were used for the calculations. The results derived in the present study show good agreement with the available experimental values. In all cases, the main bright excitation was the pi-->pi( *) transition. The other vertical excitations, pi-->sigma( *), n-->sigma( *), and n-->pi( *), which have not been studied before, were also investigated. First Rydberg series involving transitions from the pi orbitals to one 3s, three 3p, and five 3d orbitals were identified clearly. Several new assignments and reassignments of features in the experimental spectra were suggested. Contrary to earlier prediction, two n-sigma( *) states, along with a pi-sigma( *) state in the dichloroethylenes, were calculated to be located above the main pi-pi( *) state. Accordingly, crossing between both the n-sigma( *) states with the bright pi-pi( *) state is highly likely, unlike conclusions made in the earlier studies. This indicates that the photodissociation mechanism proposed by the earlier calculations warrants revision. Several low-lying triplet excited states were also studied. Electronic spectra of trans-1-chloro-2-fluoroethylene and cis-1-chloro-2-fluoroethylene were also calculated. The pi-->pi( *) transitions of these haloethylenes are compared and interpreted in terms of the inductive and resonance effects. PMID:19045357

Arulmozhiraja, Sundaram; Ehara, Masahiro; Nakatsuji, Hiroshi

2008-11-01

14

Prenatal and Early Childhood Exposure to Tetrachloroethylene and Adult Vision  

PubMed Central

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

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

15

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

PubMed

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

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

2008-12-01

16

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

PubMed Central

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

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

17

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 ...

18

Dissolution of residual tetrachloroethylene in fractional wettability porous media: correlation development and application  

Microsoft Academic Search

This work explores the dissolution behavior of residual tetrachloroethylene (PCE) in chemically heterogeneous soils. A numerical solute transport simulator, that incorporates rate-limited dissolution and desorption using linear driving force expressions, was developed and applied to analyze soil column dissolution data and to conduct numerical dissolution experiments. Published mass transfer coefficients were unable to accurately predict the observed dissolution of entrapped

Scott A. Bradford; Thomas J. Phelan; Linda M. Abriola

2000-01-01

19

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...

20

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...

21

Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses  

Microsoft Academic Search

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), during surfactant flushing. Batch experiments were performed to determine the equilibrium solubilization capacity of the surfactant, polyoxyethylene (20) sorbitan monooleate (Tween 80), and to measure

Tammy P. Taylor; Kurt D. Pennell; Linda M. Abriola; Jacob H. Dane

2001-01-01

22

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

SciTech Connect

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.

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

2003-01-01

23

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 ...

24

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)...

25

Tetrachloroethylene in Drinking Water and Birth Outcomes at the US Marine Corps Base at Camp Lejeune, North Carolina  

Microsoft Academic Search

A study of mean birth weight, small-for-gestational-age infants, and preterm birth was conducted at the US Marine Corps Base at Camp Lejeune, North Carolina, where drinking water was contaminated with volatile organic compounds. Tetrachloroethylene (PCE) was the predominant contaminant. The authors used multiple linear and logistic regression to analyze 1968-1985 data from 11,798 birth certificates. Overall, at most weak associations

N. Sonnenfeld; I. Hertz-Picciotto; W. E. Kaye

2001-01-01

26

Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses. 1. Experimental studies.  

PubMed

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), during surfactant flushing. Batch experiments were performed to determine the equilibrium solubilization capacity of the surfactant, polyoxyethylene (20) sorbitan monooleate (Tween 80), and to measure fluid viscosity, density and interfacial tension. Results of one-dimensional column studies indicated that micellar solubilization of residual PCE was rate-limited at Darcy velocities ranging from 0.8 to 8.2 cm/h and during periods of flow interruption. Effluent concentration data were used to develop effective mass transfer coefficient (Ke) expressions that were dependent upon the Darcy velocity and duration of flow interruption. To simulate subsurface heterogeneity, 2-D boxes were packed with layers of F-70 Ottawa sand and Wurtsmith aquifer material within 20-30 mesh Ottawa sand. A 4% Tween 80 solution was then flushed through PCE-contaminated boxes at several flow velocities, with periods of flow interruption. Effluent concentration data and visual observations indicated that both rate-limited solubilization and pooling of PCE above the fine layers reduced PCE recovery to levels below those anticipated from batch and column measurements. These experimental results demonstrate the potential impact of both mass transfer limitations and subsurface layering on the recovery of PCE during surfactant enhanced aquifer remediation. PMID:11285937

Taylor, T P; Pennell, K D; Abriola, L M; Dane, J H

2001-04-01

27

Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses. 1. Experimental studies  

NASA Astrophysics Data System (ADS)

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), during surfactant flushing. Batch experiments were performed to determine the equilibrium solubilization capacity of the surfactant, polyoxyethylene (20) sorbitan monooleate (Tween 80), and to measure fluid viscosity, density and interfacial tension. Results of one-dimensional column studies indicated that micellar solubilization of residual PCE was rate-limited at Darcy velocities ranging from 0.8 to 8.2 cm/h and during periods of flow interruption. Effluent concentration data were used to develop effective mass transfer coefficient ( Ke) expressions that were dependent upon the Darcy velocity and duration of flow interruption. To simulate subsurface heterogeneity, 2-D boxes were packed with layers of F-70 Ottawa sand and Wurtsmith aquifer material within 20-30 mesh Ottawa sand. A 4% Tween 80 solution was then flushed through PCE-contaminated boxes at several flow velocities, with periods of flow interruption. Effluent concentration data and visual observations indicated that both rate-limited solubilization and pooling of PCE above the fine layers reduced PCE recovery to levels below those anticipated from batch and column measurements. These experimental results demonstrate the potential impact of both mass transfer limitations and subsurface layering on the recovery of PCE during surfactant enhanced aquifer remediation.

Taylor, Tammy P.; Pennell, Kurt D.; Abriola, Linda M.; Dane, Jacob H.

2001-04-01

28

Dependence of tetrachloroethylene dechlorination on methanogenic substrate consumption by Methanosarcina sp. strain DCM.  

PubMed Central

Tetrachloroethylene (perchloroethylene, PCE) is a suspected carcinogen and a common groundwater contaminant. Although PCE is highly resistant to aerobic biodegradation, it is subject to reductive dechlorination reactions in a variety of anaerobic habitats. The data presented here clearly establish that axenic cultures of Methanosarcina sp. strain DCM dechlorinate PCE to trichloroethylene and that this is a biological reaction. Growth on methanol, acetate, methylamine, and trimethylamine resulted in PCE dechlorination. The reductive dechlorination of PCE occurred only during methanogenesis, and no dechlorination was noted when CH4 production ceased. There was a clear dependence of the extent of PCE dechlorination on the amount of methanogenic substrate (methanol) consumed. The amount of trichloroethylene formed per millimole of CH4 formed remained essentially constant for a 20-fold range of methanol concentrations and for growth on acetate, methylamine, and trimethylamine. These results suggest that the reducing equivalents for PCE dechlorination are derived from CH4 biosynthesis and that the extent of chloroethylene dechlorination can be enhanced by stimulating methanogenesis. It is proposed that electrons transferred during methanogenesis are diverted to PCE by a reduced electron carrier involved in methane formation. Images PMID:3223763

Fathepure, B Z; Boyd, S A

1988-01-01

29

Reductive dechlorination of Tri- and tetrachloroethylenes depends on transition from aerobic to anaerobic conditions.  

PubMed Central

Aerobic enrichment cultures from contaminated groundwaters dechlorinated trichloroethylene (TCE) (14.6 mg/liter; 111 mumol/liter) and tetrachloroethylene (PCE) (16.2 mg/liter; 98 mumol/liter) reductively within 4 days after the transition from aerobic to anaerobic conditions. The transformation products were equimolar amounts of cis-1,2-dichloroethylene and traces of 1,1-dichloroethylene. No other chlorinated product and no methane were detected. The change was accompanied by the release of sulfide, which caused a decrease in the redox potential from 0 to -150 mV. In sterile control experiments, sulfide led to the abiotic formation of traces of 1,1-dichloroethylene without cis-1,2-dichloroethylene production. The reductive dechlorination of PCE via TCE depended on these specific transition conditions after consumption of the electron acceptor oxygen or nitrate. Repeated feeding of TCE or PCE to cultures after the change to anaerobic conditions yielded no further dechlorination. Only aerobic subcultures with an air/liquid ratio of 1:4 maintained dechlorination activities; anaerobic subcultures showed no transformation. Bacteria from noncontaminated sites showed no reduction under the same conditions. PMID:1892393

Kästner, M

1991-01-01

30

Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses. 2. Numerical simulation  

NASA Astrophysics Data System (ADS)

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, batch and column experiments. These parameters included viscosity, density, solubilization capacity, surfactant sorption, interfacial tension, permeability, capillary retention functions, and interphase mass transfer correlations. Model predictive capability was assessed for the evaluation of the micellar solubilization of tetrachloroethylene (PCE) in the two-dimensional systems. Predicted effluent concentrations and mass recovery agreed reasonably well with measured values. Accurate prediction of enhanced solubilization behavior in the sand tanks was found to require the incorporation of pore-scale, system-dependent, interphase mass transfer limitations, including an explicit representation of specific interfacial contact area. Predicted effluent concentrations and mass recovery were also found to depend strongly upon the initial NAPL entrapment configuration. Numerical results collectively indicate that enhanced solubilization processes in heterogeneous, laboratory sand tank systems can be successfully simulated using independently measured soil parameters and column-measured mass transfer coefficients, provided that permeability and NAPL distributions are accurately known. This implies that the accuracy of model predictions at the field scale will be constrained by our ability to quantify soil heterogeneity and NAPL distribution.

Rathfelder, Klaus M.; Abriola, Linda M.; Taylor, Tammy P.; Pennell, Kurt D.

2001-04-01

31

Biological exposure assessment to tetrachloroethylene for workers in the dry cleaning industry  

PubMed Central

Background The purpose of this study was to assess the feasibility of conducting biological tetrachloroethylene (perchloroethylene, PCE) exposure assessments of dry cleaning employees in conjunction with evaluation of possible PCE health effects. Methods Eighteen women from four dry cleaning facilities in southwestern Ohio were monitored in a pilot study of workers with PCE exposure. Personal breathing zone samples were collected from each employee on two consecutive work days. Biological monitoring included a single measurement of PCE in blood and multiple measurements of pre- and post-shift PCE in exhaled breath and trichloroacetic acid (TCA) in urine. Results Post-shift PCE in exhaled breath gradually increased throughout the work week. Statistically significant correlations were observed among the exposure indices. Decreases in PCE in exhaled breath and TCA in urine were observed after two days without exposure to PCE. A mixed-effects model identified statistically significant associations between PCE in exhaled breath and airborne PCE time weighted average (TWA) after adjusting for a random participant effect and fixed effects of time and body mass index. Conclusion Although comprehensive, our sampling strategy was challenging to implement due to fluctuating work schedules and the number (pre- and post-shift on three consecutive days) and multiplicity (air, blood, exhaled breath, and urine) of samples collected. PCE in blood is the preferred biological index to monitor exposures, but may make recruitment difficult. PCE TWA sampling is an appropriate surrogate, although more field intensive. Repeated measures of exposure and mixed-effects modeling may be required for future studies due to high within-subject variability. Workers should be monitored over a long enough period of time to allow the use of a lag term. PMID:18412959

McKernan, Lauralynn T; Ruder, Avima M; Petersen, Martin R; Hein, Misty J; Forrester, Christy L; Sanderson, Wayne T; Ashley, David L; Butler, Mary A

2008-01-01

32

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

PubMed

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

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

2002-07-01

33

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

SciTech Connect

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.

Tuck, D.M.

1999-02-23

34

The effect of low concentrations of tetrachloroethylene on H2 adsorption and activation on Pt in a fuel cell catalyst  

NASA Astrophysics Data System (ADS)

The poisoning effect of tetrachloroethylene (TTCE) on the activity of a Pt fuel cell catalyst for the adsorption and activation of H2 was investigated at 60 °C and 2 atm using hydrogen surface concentration measurements. The impurity was chosen as a model compound for chlorinated cleaning and degreasing agents that may be introduced into a fuel cell as a contaminant at a fueling station and/or during vehicle maintenance. In the presence of only H2, introduction of up to 540 ppm TTCE in H2 to Pt/C resulted in a reduction of available Pt surface atoms (measured by H2 uptake) by ca. 30%, which was not enough to shift the H2-D2 exchange reaction away from being equilibrium limited. Exposure of TTCE to Pt/C in a mixed redox environment (hydrogen + oxygen), similar to that at the cathode of a fuel cell, resulted in a much more significant loss of Pt surface atom availability, suggesting a role in TTCE decomposition and/or Cl poisoning. Regeneration of catalyst activity of poisoned Pt/C showed the highest level of recovery when regenerated in only H2, with much less recovery in H2 + O2 or O2. The results from this study are in good agreement with those found in a fuel cell study by Martínez-Rodríguez et al. [2] and confirm that the majority of the poisoning from TTCE on fuel cell performance is most likely at the cathode, rather than the anode.

Zhang, Jack Z.; Colón-Mercado, Héctor R.; Goodwin, James G.

2011-10-01

35

Reductive dechlorination of tetrachloroethylene and trichloroethylene catalyzed by vitamin B{sub 12} in homogeneous and heterogeneous systems  

SciTech Connect

The reduction of tetrachloroethylene (PCE) and trichloroethylene (TCE) catalyzed by vitamin B{sub 12} was examined in homogeneous and heterogeneous (B{sub 12} bound to agarose) batch systems using titanium(III) citrate as the bulk reductant. The solution and surface-mediated reaction rates at similar B{sub 12} loadings were comparable, indicating that binding vitamin B{sub 12} to a surface did not lower catalytic activity. No loss in PCE reducing activity was observed with repeated usage of surface-bound vitamin B{sub 12}. Carbon mass recoveries were 81-84% for PCE reduction and 89% for TCE reduction, relative to controls. In addition to sequential hydrogenolysis, a second competing reaction mechanism for the reduction of PCE and TCE by B{sub 12}, reductive {beta}-elimination, is proposed to account for the observation of acetylene as a significant reaction intermediate. Reductive {beta}-elimination should be considered as a potential pathway in other reactive systems involving the reduction of vicinal polyhaloethenes. Surface-bound catalysts such as vitamin B{sub 12} may have utility in the engineered degradation of aqueous phase chlorinated ethenes. 19 refs., 6 figs., 1 tab.

Burris, D.R.; Smith, M.H. [Armstrong Lab., Tyndall Air Force Base, FL (United States)] [Armstrong Lab., Tyndall Air Force Base, FL (United States); Delcomyn, C.A. [Applied Research Associates, Inc., Tyndall Air Force Base, FL (United States)] [Applied Research Associates, Inc., Tyndall Air Force Base, FL (United States); Roberts, A.L. [Johns Hopkins Univ., Baltimore, MD (United States)] [Johns Hopkins Univ., Baltimore, MD (United States)

1996-10-01

36

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

PubMed Central

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

Koizumi, A

1989-01-01

37

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

PubMed Central

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

2009-01-01

38

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

PubMed

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

Johnston, Jill E; Gibson, Jacqueline MacDonald

2014-11-01

39

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

PubMed Central

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

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

40

Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes  

PubMed Central

Background From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC) water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE). Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Methods Once aware of the leaching problem and prior to remediation (April-November 1980), Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88) with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. Results The mean and median measured PCE concentrations in the water samples were 66 and 0.5 ?g/L, respectively, and the range extended from non-detectable to 2432 ?g/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p < 0.0001). Correlations were higher in samples taken at taps and spigots vs. hydrants (? = 0.84 vs. 0.34), in areas with simple vs. complex geometry (? = 0.51 vs. 0.38), and near pipes installed in 1973–1976 vs. other years (? = 0.56 vs. 0.42 for 1968–1972 and 0.37 for 1977–1980). Overall, 24% of the variance in measured PCE concentrations was explained by the model-generated concentration estimates (p < 0.0001). Almost half of the water samples had undetectable concentrations of PCE. Undetectable levels were more common in areas with the earliest installed VL/AC pipes, at the beginning and middle of VL/AC pipes, at hydrants, and in complex pipe configurations. Conclusion PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available. PMID:18518975

Spence, Lisa A; Aschengrau, Ann; Gallagher, Lisa E; Webster, Thomas F; Heeren, Timothy C; Ozonoff, David M

2008-01-01

41

Concentration of tetrachloroethylene in indoor air at a former dry cleaner facility as a function of subsurface contamination: a case study.  

PubMed

A field study was performed to evaluate indoor air concentrations and vapor intrusion (VI) of tetrachloroethylene (PCE) and other chlorinated solvents at a commercial retail site in Dallas, TX. The building is approximately 40 yr old and once housed a dry cleaning operation. Results from an initial site characterization were used to select sampling locations for the VI study. The general approach for evaluating VI was to collect time-integrated canister samples for off-site U.S. Environmental Protection Agency Method TO-15 analyses. PCE and other chlorinated solvents were measured in shallow soil gas, subslab soil-gas, indoor air, and ambient air. The subslab soil gas exhibited relatively high values: PCE < or =2,600,000 parts per billion by volume (ppbv) and trichloroethylene < or =170 ppbv. The attenuation factor, the ratio of indoor air and subslab soil-gas concentrations, was unusually low: approximately 5 x 10(-6) based on the maximum subslab soil-gas concentration of PCE and 1.4 x 10(-5) based on average values. PMID:17608009

Eklund, Bart M; Simon, Michelle A

2007-06-01

42

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

PubMed

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

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

2013-01-01

43

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

PubMed Central

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

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

2013-01-01

44

Impact of tetrachloroethylene-contaminated drinking water on the risk of breast cancer: Using a dose model to assess exposure in a case-control study  

PubMed Central

Background A population-based case-control study was undertaken in 1997 to investigate the association between tetrachloroethylene (PCE) exposure from public drinking water and breast cancer among permanent residents of the Cape Cod region of Massachusetts. PCE, a volatile organic chemical, leached from the vinyl lining of certain water distribution pipes into drinking water from the late 1960s through the early 1980s. The measure of exposure in the original study, referred to as the relative delivered dose (RDD), was based on an amount of PCE in the tap water entering the home and estimated with a mathematical model that involved only characteristics of the distribution system. Methods In the current analysis, we constructed a personal delivered dose (PDD) model that included personal information on tap water consumption and bathing habits so that inhalation, ingestion, and dermal absorption were also considered. We reanalyzed the association between PCE and breast cancer and compared the results to the original RDD analysis of subjects with complete data. Results The PDD model produced higher adjusted odds ratios than the RDD model for exposures > 50th and >75th percentile when shorter latency periods were considered, and for exposures < 50th and >90th percentile when longer latency periods were considered. Overall, however, the results from the PDD analysis did not differ greatly from the RDD analysis. Conclusion The inputs that most heavily influenced the PDD model were initial water concentration and duration of exposure. These variables were also included in the RDD model. In this study population, personal factors like bath and shower temperature, bathing frequencies and durations, and water consumption did not differ greatly among subjects, so including this information in the model did not significantly change subjects' exposure classification. PMID:15733317

Vieira, Verónica; Aschengrau, Ann; Ozonoff, David

2005-01-01

45

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

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

2011-01-01

46

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

PubMed Central

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

2011-01-01

47

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

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

Harte, Philip T.

2004-01-01

48

NEUROTOXICITY OF TETRACHLOROETHYLENE (PERCHLOROETHYLENE): DISCUSSION PAPER  

EPA Science Inventory

This paper is a background document for a meeting of neurotoxicity experts to discuss the central nervous system effects of exposure to perchloroethylene (perc). The document reviews the literature on neurological testing of people exposed to perc occupationally in dry cleanin...

49

Tetrachloroethylene Degradation by Dithionite with Ultraviolet Activation  

E-print Network

. This project has conducted research on degrading PCE with an ARP that combines dithionite and ultraviolet activation. The purpose of the project is to provide knowledge for the development of potential wastewater treatment technologies. Several control...

Zhang, Jingyuan

2013-07-30

50

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...

51

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), ...

52

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

Code of Federal Regulations, 2013 CFR

...reporting. (1) The following chemical substance referred to by...notice number and generic chemical name is subject to reporting...against dusts having an air contamination level not less than 0...duration of exposure, associated chemical substances, chemical...

2013-07-01

53

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

Code of Federal Regulations, 2011 CFR

...reporting. (1) The following chemical substance referred to by...notice number and generic chemical name is subject to reporting...against dusts having an air contamination level not less than 0...duration of exposure, associated chemical substances, chemical...

2011-07-01

54

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

Code of Federal Regulations, 2012 CFR

...reporting. (1) The following chemical substance referred to by...notice number and generic chemical name is subject to reporting...against dusts having an air contamination level not less than 0...duration of exposure, associated chemical substances, chemical...

2012-07-01

55

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

Code of Federal Regulations, 2014 CFR

...reporting. (1) The following chemical substance referred to by...notice number and generic chemical name is subject to reporting...against dusts having an air contamination level not less than 0...duration of exposure, associated chemical substances, chemical...

2014-07-01

56

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...

57

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, ...

58

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

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).

Harte, Philip T.

2012-01-01

59

Race, class and environmental equity: s study of disparate cxposure to toxic chemicals in the Commonwealth of Massachusetts.  

E-print Network

??This report compares chemicals (diethylhexylpthalate, chromium, formaldehyde, lead, and tetrachloroethylene) and chemical groups (carcinogens, ""more hazardous chemicals"" organochlorines persistent bio-accumulative toxics, and reproductive toxics) used… (more)

Pritchard, Henderson W.

2009-01-01

60

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...

61

MULTIDISCIPLINARY APPROACH TO TOXICOLOGICAL SCREENING: I. SYSTEMIC TOXICITY  

EPA Science Inventory

The toxicity of 10 chemicals (carbaryl, carbon tetrachloride, chlordane, ethylhexylphthalate, dichloromethane, heptachlor, phenol, tetrachloroethylene, triadimefon, and trichloroethylene were examined in the liver, kidney, spleen, thymus, and adrenal of female F-344 rats. cute le...

62

Does increasing the temperature induce DNAPL migration?  

EPA Science Inventory

Tetrachloroethylene, trichloroethylene, and chlorobenzene have been identified as contaminants in groundwater and are sometimes called Dense Non-Aqueous Phase Liquids (DNAPL). Thermal methods for remediation of contaminated soils and groundwater rely on raising the temperature o...

63

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...

64

EMERGING TECHNOLOGY BULLETIN: TWO-ZONE PCE BIOREMEDIATION SYSTEM - ABB ENVIRONMENTAL SERVICES, INC. - U.S. ENVIRONMENTAL PROTECTION AGENCY  

EPA Science Inventory

ABB Environmental Services, Inc.'s (ABB-ES), research has demonstrated that sequential anaerobic/aerobic biodegradation of tetrachloroethylene (PCE) is feasible if the proper conditions can be established. The anaerobic process can potentially completely dechlorinate PCE. Howeve...

65

Zevenhoven & Kilpinen Halogens, dioxins/furans 17.6.2001 7-1 Chapter 7 Halogens,  

E-print Network

(e.g. tetrachloroethylene), in electronics industry (CCl4), flame/fire retardants (chloroparaffins compound CCl4. Fluorine is mainly found as HF in some fossil fuel-derived gases or when processing glass

Zevenhoven, Ron

66

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...

67

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...

68

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,...

69

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...

70

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...

71

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...

72

Determination of adsorption isotherms of chlorinated hydrocarbons on halloysite adsorbent by inverse gas chromatography.  

PubMed

Inverse gas chromatographic methods of isotherm determination peak maximum (PM) and peak division (PD) were compared. These methods were applied to determine adsorption isotherms of dichloroethylene, trichloroethylene and tetrachloroethylene on acid-activated halloysite and adsorption enthalpy. PMID:23523065

Czech, K; S?omkiewicz, P M

2013-05-01

73

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...

74

BIOTRANSFORMATION OF TRICHLOROETHYLENE IN SOIL  

EPA Science Inventory

The organic contaminants that are most commonly detected in groundwater are low-molecular-weight, chlorinated aliphatic hydrocarbons such as trichloroethylene (TCE), tetrachloroethylene (PCE), 1,1,1-trichloroethane, carbon tetrachloride, and chloroform. The authors exposed unsatu...

75

40 CFR Appendix Viii to Part 261 - Hazardous Constituents  

Code of Federal Regulations, 2013 CFR

...460-19-5 P031Cyanogen bromide Cyanogen bromide (CN)Br506-68-3 U246Cyanogen chloride Cyanogen chloride...79-34-5 U209Tetrachloroethylene Ethene, tetrachloro-127-18-4 U2102,3,4,6-Tetrachlorophenol...

2013-07-01

76

40 CFR Appendix Viii to Part 261 - Hazardous Constituents  

Code of Federal Regulations, 2012 CFR

...460-19-5 P031Cyanogen bromide Cyanogen bromide (CN)Br506-68-3 U246Cyanogen chloride Cyanogen chloride...79-34-5 U209Tetrachloroethylene Ethene, tetrachloro-127-18-4 U2102,3,4,6-Tetrachlorophenol...

2012-07-01

77

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...

78

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...

79

In vivo exposure of female rats to toxicants may affect oocyte quality.  

PubMed

A potential endpoint for female reproductive toxicants is fertilizability of the oocytes. This endpoint has not been adequately examined for mammalian females. The objective of these studies was to evaluate fertilizability of rat oocytes following in vivo exposure to known male reproductive toxicants that exert effects via pathways that do not include endocrine disruption and to 4-vinylcyclohexene diepoxide, known to interfere with early follicular development. Oocytes were obtained from females following exposure and quality assessed by in vitro fertilization rate. One study evaluated fertilizability following 2 weeks exposure of females to inhaled tetrachloroethylene (2h/day, 5 days/week). The remaining studies evaluated fertilizability immediately following 2 weeks exposure via drinking water to tetrachloroethylene, trichloroethylene, the fuel oxidants methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), and a metabolite of the first two ethers 2-methyl-1,2-propanediol (2M2P), and to 4-vinylcyclohexene diepoxide. The percentage of oocytes fertilized was reduced following inhalation exposure to tetrachloroethylene, or consumption of trichloroethylene or TAME. Fertilizability was not altered by exposures to the other reproductive toxicants or to the other fuel oxidants. Consistent with the reduced oocyte fertilizability following exposure to trichloroethylene, oocytes from exposed females had a reduced ability to bind sperm plasma membrane proteins. Female reproductive capability assessed by the endpoint, oocyte fertilizability, was reduced by exposure to trichloroethylene and inhaled tetrachloroethylene. PMID:12759095

Berger, Trish; Horner, Catherine M

2003-01-01

80

3, 54695512, 2003 chlorocarbons over  

E-print Network

and Physics Discussions Measurements of reactive chlorocarbons over the Surinam tropical rain forest the Surinam rainforest. From our measurements, we deduce fluxes from the Surinam rain- forest of 7.6±1.8 µg CH, and tetrachloroethylene mixing ratios, in pristine air masses ad- vected from the Atlantic Ocean toward the central Amazon

Paris-Sud XI, Université de

81

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...

82

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...

83

Volatile halocarbons as tracers of pulp mill effluent plumes  

Microsoft Academic Search

This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloromethane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of

M. E. Comba; V. S. Palabrica; K. L. E. Kaiser

1994-01-01

84

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

Microsoft Academic Search

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

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

2006-01-01

85

Dynamic partitioning of organic chemicals in regional environments: A multimedia screening-level modeling approach  

SciTech Connect

A screening-level spatial-multimedia-compartmental (SMCM) approach to modeling the fate and transport of volatile organic pollutants in regional environments is presented. The SMCM approach, which makes use of both uniform (i.e., well-mixed) and nonuniform (one-dimensional) compartments, incorporates a variety of transport phenomena associated with pollutant transport such as dry deposition, rain scavenging, runoff, infiltration, soil drying, and pollutant diffusion and convection in the vadose zone. The multimedia distributions of trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane in the Los Angeles area, and tetrachloroethylene in the San Diego area, were explored by using the SMCM model. The predicted concentrations were found to be in reasonable agreement with the available field data. The study suggests that the SMCM approach is useful and efficient for rapid screening-level analysis of the steady-state or dynamic multimedia distribution of chemical pollutants.

Cohen, Y.; Tsai, Wangteng; Chetty, S.L.; Mayer, G.J. (Univ. of California, Los Angeles (USA))

1990-10-01

86

Health assessment for Keystone Sanitation Landfill, Union Township, Adams County, Pennsylvania, Region 3. CERCLIS No. PAD054142781. Preliminary report  

SciTech Connect

The Keystone Sanitation Landfill site is a former farm which began receiving municipal waste and industrial construction debris in September 1966. The still active site is situated on a ridge, and runoff leaves the site from all directions. The environmental contamination on-site consists of 1,1,1-trichloroethane, trichloroethylene, vinyl chloride, benzene, 1,1-dichloroethane, 1,1-dichloroethylene, tetrachloroethylene, trans-1,2-dichloroethylene, chromium, lead, and N-nitrosodiphenylamine in groundwater. The environmental contamination off-site consists of tetrachloroethylene, 1,1,1-trichloroethane, 1,1-dichloroethylene, 1,1-dichloroethane, trichloroethylene in surface water; and lead, vinyl chloride, and 1,2-dichloroethylene in private wells. 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 groundwater, soil, and surface water.

Not Available

1988-10-11

87

Critical contaminant/critical pathway analysis - surface water transport for nonradioactive contaminants  

SciTech Connect

The health risks for an individual exposed to contaminants released from SRS outfalls from 1989 to 1995 were estimated. The exposure pathways studied are ingestion of drinking water, ingestion of contaminated fish and dermal contact with contaminants in water while swimming. The estimated incremental risks for an individual developing cancer vary from 3.E-06 to 1.0E-05. The estimated total exposure chronic noncancer hazard indices vary from 6.E-02 to 1.E-01. The critical contaminants were ranked based on their cancer risks and chronic noncarcinogenic hazard quotients. For cancer risks, the critical contaminants released from SRS outfalls are arsenic, tetrachloroethylene, and benzene. For chronic noncarcinogenic risks, the critical contaminants released from srs outfalls are cadmium, arsenic, silver, chromium, mercury, selenium, nitrate, manganese, zinc, nickel, uranium, barium, copper, tetrachloroethylene, cyanide, and phenol. The critical pathways in decreasing risk order are ingestion of contaminated fish, ingestion of drinking water and dermal contact with contaminants in water while swimming.

Chen, Kuo-Fu

1996-11-01

88

Movement of VOCs through the vadose zone  

E-print Network

- and penta-chlorobenzene, methylene chlo- ride, tetrachloroethylene, toluene and vinyl chloride. Petroleum industries produce various hydrocarbons, the most common of which are methane, benzene, xylenes and toluene. This thesis is formatted according... Surface zinc/2 zinc i- 1 i+ 1 I I I I n+1 L Last Cell Lower Boundary Imaginary Cell Fig. 3. L One Dimensional Model 25 8. C. 1. Digusi on The diffusion equation is parabolic in time and elliptic in space, and overall is a parabolic partial...

Patel, Pinakin K.

1989-01-01

89

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

Microsoft Academic Search

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

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

2003-01-01

90

Vibrating pervaporation modules: Effect of module design on performance  

Microsoft Academic Search

A commercial-scale vibrating pervaporation membrane module was fabricated and evaluated for the separation of volatile organic compounds (VOCs) from aqueous solutions. Experiments with surrogate solutions of four hydrophobic VOCs (1,1,1-trichloroethane (TCA), trichloroethylene (TCE), tetrachloroethylene (PCE), and methyl t-butyl ether (MTBE)) were performed. VOC removal performance for this module was compared to published data for two earlier full-scale vibrating modules of

Leland M. Vane; Franklin R. Alvarez

2005-01-01

91

Clastogenicity evaluation of seven chemicals commonly found at hazardous industrial-waste sites  

Microsoft Academic Search

Seven chemicals commonly found at industrial waste sites were tested with the Tradescantia-micronucleus (Trad-MCN) assay to evaluate their clastogenic potential. They were: Aldrin, arsenic trioxide, 1,2-benz(a,h)anthracene, dieldrin, heptachlor, lead tetraacetate, and tetrachloroethylene. Results of repeated tests for clastogenicity yielded the minimum effective dose (MED) of 0.44 ppm for lead tetraacetate, 3.81 ppm for dieldrin, and 1.88 ppm for heptachlor. Arsenic

S. S. Sandhu; T. H. Ma; Y. Peng; X. Zhou

1989-01-01

92

EXTRACTION OF Am FROM NITRIC ACID BY CARBAMOYL-PHOSPHORYL EXTRACTANTS: THE INFLUENCE OF SUBSTITUENTS ON THE SELECTIVITY OF Am OVER Fe AND SELECTED FISSION PRODUCTS  

Microsoft Academic Search

A number of neutral extractants containing the P(0)(CH2)nC(0)N raolety were evaluated for their ability to extract Am from nitric acid and their selectivity for Am over Fe and selected fission products. Extractants containing alkoxy, alkyl, and aryl substltuents were evaluated. Tetrachloroethylene was used as a diluent. Fission products selected for study were Y, Zr, Mo, Tc, Ru, Rh, Pd, La,

E. Philip Horwltz; Kathleen A. Martin; Herbert Diamond; Louis Kaplan

1986-01-01

93

Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons  

DOEpatents

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.

Fliermans, Carl B. (Augusta, GA)

1989-01-01

94

A method for the rapid dechlorination of low molecular weight chlorinated hydrocarbons in water  

Microsoft Academic Search

1,1,2-Trichloroethylene (TCE), 1,1-dichloroethylene, cis and trans-1,2-dichloroethylene and tetrachloroethylene (PCE), at concentrations of 20 ppm in aqueous solutions were rapidly hydrodechlorinated to ethane (in a few minutes), on the surface of palladized iron in batch experiments that were performed in closed vials. No intermediate reaction products such as 1,1-dichloroethylene, 1,2-dichloroethylenes and vinyl chloride were detected at concentrations > 1 ppm either

Rosy Muftikian; Quintus Fernando; Nic Korte

1995-01-01

95

The effect of humic acid on the transport of volatile chlorinated hydrocarbons in soil  

Microsoft Academic Search

Flow-through column experiments were conducted to estimate the change of the concentration of three chlorinated VOCs (chloroform, trichloroethylene and tetrachloroethylene) in two types of soil. The two soils were a terra rosa with organic carbon content of 1.32% and a sandy clay loam with organic carbon content of 0.26%. The experiments took place for 116?g\\/l single solutes in the absence

E Diamadopoulos; D Sakellariadis; E Koukouraki

1998-01-01

96

Environmental risk assessment of airborne trichloroacetic acid--a contribution to the discussion on the significance of anthropogenic and natural sources.  

PubMed

In environmental risk assessments the question has to be answered, whether risk reduction measures are necessary in order to protect the environment. If the combination of natural and anthropogenic sources of a chemical substance leads to an unacceptable risk, the man-made emissions have to be reduced. In this case the proportions of the anthropogenic and natural emissions have to be quantified. Difficulties and possible solutions are discussed in the scope of the OECD- and EU-risk assessments of trichloroacetic acid (TCA) and tetrachloroethylene. In the atmosphere, TCA is formed by photo-oxidative degradation of tetrachloroethylene (PER) and 1,1,1-trichloroethane. The available data on atmospheric chemistry indicate that tetrachloroethylene is the more important pre-cursor. With its high water solubility and low volatility, TCA is adsorbed onto aerosol particles and precipitated during rainfalls. Extended monitoring in rainwater confirmed the global distribution of airborne TCA. TCA reaches soils by dry and wet deposition. In addition formation of TCA from tetrachloroethylene in plants was observed. Consequently, high concentrations were detected in needles, leaves and in forest soil especially in mountain regions. The effect assessment revealed that plants exposed via soil are the most sensitive species compared to other terrestrial organisms. A PNECsoil of 2.4 microg/kg dw was derived from a long-term study with pine and spruce seedlings. When this PNEC is compared with the measured concentrations of TCA in soil, in certain regions a PEC/PNEC ratio >1 is obtained. This clearly indicates a risk to the terrestrial ecosystem, with the consequence that risk reduction measures are deemed necessary. To quantify the causes of the high levels of TCA in certain soils, and to investigate the geographical extent of the problem, intensive and widespread monitoring of soil, air and rainwater for TCA and tetrachloroethylene would be necessary to be able to perform a full mass balance study at an appropriate number of sites. In addition, measurements of the 14C content in TCA isolated from soil could clarify whether a significant proportion of the TCA occurs from natural sources. The possible formation of TCA in soil can also be tested by incubation of isotope enriched inorganic chloride with subsequent mass spectrometry of TCA. PMID:12738278

Ahlers, Jan; Regelmann, Jürgen; Riedhammer, Caroline

2003-07-01

97

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

USGS Publications Warehouse

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.

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

1994-01-01

98

Spectrum of the reductive dehalogenation activity of Desulfitobacterium frappieri PCP-1  

SciTech Connect

Desulfitobacterium frappieri PCP-1 was induced for ortho- and para-dechlorinating activities by different chlorophenols. Dehalogenation rates ranging from 25 to 1,158 nmol/min/mg of cell protein were observed according to the chlorophenol tested and the position of the chlorine removed. D. frappieri shows a broad substrate specificity; in addition to tetrachloroethylene and pentachloropyridine, strain PCP-1 can dehalogenate at ortho, meta, and para positions a large variety of aromatic molecules with substituted hydroxyl or amino groups. Reactions of O demethylation and reduction of nitro to amino substituents on aromatic molecules were also observed.

Dennie, D.; Gladu, I.; Lepine, F.; Villemur, R.; Bisaillon, J.G.; Beaudet, R. [Univ. du Quebec, Ville de Laval, Quebec (Canada). Centre de Recherche en Microbiologie Appliquee

1998-11-01

99

Azo Dyes and Their Interfacial Activity: Implications for Multiphase Flow Experiments  

SciTech Connect

Interfacial effects play an important role in governing multiphase fluid behavior in porous media (Neustadter 1984; Tuck et al. 1988). For instance, several dimensionless numbers have been developed to express important force ratios applicable to multiphase flow in porous media (Morrow and Songkran 1981; Chatzis and Morrow 1984; Wardlaw 1988; Pennell et al. 1996; Dawson and Roberts 1997). These force ratios emphasize the importance of interfacial properties. Our objectives are to provide chemical information regarding the dyes commonly used in multiphase flow visualization studies and to show the surface chemistry effects of the most commonly used dye, Sudan IV, in the tetrachloroethylene (PCE)-water-glass system

Tuck, D.M.

1999-04-21

100

Surfactant enchanced removal of dense nonaqueous phase liquids (DNAPLs) from porous media  

SciTech Connect

Fifteen surfactants were investigated for use in enhanced in-situ removal of residual DNAPLs (dense nonaqueous phase liquids) from sandy aquifer materials. Surfactant performance was primarily evaluated based on the ability of the surfactant to enhance solubilization of the organic liquid at low surfactant concentrations while minimizing reduction of the interfacial tension between the organic liquid and water. Other performances criteria evaluated include carbon tetrachloride, chlorobenzene, 1,2-dichloroethane, tetrachloroethylene, and trichloroethylene. Significant differences in performance were observed among the surfactants and related to surfactant structure and composition, as well as organic liquid properties. A rapid screening test was developed to assess the efficiency of the surfactants for field applications.

Josselyn, L.P.; Dawson, H. [Colorado School of Mines, Golden, CO (United States)

1993-12-31

101

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

SciTech Connect

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.

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

2006-06-21

102

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

SciTech Connect

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.

Thompson, C.Y.

1993-09-01

103

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

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.

Hazen, T.C.

1991-09-18

104

Thermal degradation products of solvents and hydraulic fluids used in mining. Report of investigations/1981  

SciTech Connect

The Bureau of Mines sponsored an investigation of the thermal oxidative degradation characteristics of certain solvents and hydraulic fluids used in underground mining operations. The following halogenated solvents were studied in view of their usefulness and their flame retardant property: tetrachloroethylene, Cl2C = CCl2; 1, 1, 2-trichloroethane, ClH2CCHCl2; and trichloroethylene, Cl2C = CHCl. The hydraulic fluids studied were representative of five groups approved by the Mine Safety and Health Administration for underground operation, namely: glycol-water solutions, mineral oil-water emulsions, synthetics other than phosphate esters, synthetic phosphate esters, and mixtures of phosphate esters with mineral oils and other ingredients.

Christos, T.; Forshey, D.R.

1981-03-01

105

Screening volatile organic compounds (VOCs) emissions from five marine phytoplankton species by head space gas chromatography/mass spectrometry (HS-GC/MS).  

PubMed

Five marine cosmopolitan phytoplankton species namely; Calcidiscus leptoporus, Emiliania huxleyi, Phaeodactylum tricornutum, Chaetoceros neogracilis and Dunaliella tertiolecta were screened for emissions of selected VOCs using head space gas chromatography/mass spectrometry (HS-GC/MS) in single ion mode. The VOCs investigated included isoprene and various halogenated compounds. Among the different algae groups, the two diatoms Ch. neogracilis and P. tricornutum were the strongest emitters of methyl bromide (CH3Br), and Ch. neogracilis was the strongest emitter of isoprene. Furthermore, we present evidence that several chlorinated organic compounds, normally considered as anthropogenic, can be produced from marine phytoplankton (namely chloroform, dichloromethane, trichloroethylene, tetrachloroethylene, chlorobenzene and dichlorobenzene). PMID:18392274

Colomb, Aurélie; Yassaa, Noureddine; Williams, Jonathan; Peeken, Ilka; Lochte, Karin

2008-03-01

106

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

SciTech Connect

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.

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

107

Experimental investigation of hot water and cosolvent flushing for remediation of NAPL-contaminated aquifers  

SciTech Connect

Pump and treat is the most commonly used method for removing contaminants from groundwater but has proven ineffective in the case of nonaqueous phase liquids (NAPLs). Two methods that have been used to enhance recovery of crude oil, hot water and alcohol flooding, were investigated in the laboratory as a means of enhancing the dissolution and recovery of NAPLs in groundwater. A ubiquitous NAPL, tetrachloroethylene (PCE), was chosen for recovery in this investigation. The PCE/methanol/water system was studied to evaluate the effect of methanol concentration on interfacial tension, equilibrium phase composition, and phase density.

Imhoff, P.T.; Miller, C.T.; Frizzell, A.; Vancho, L.A.; Gleyzer, S.N.

1995-01-01

108

TNX area groundwater monitoring report. 1996 Annual report  

SciTech Connect

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.

NONE

1997-04-01

109

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

SciTech Connect

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.

Not Available

1993-09-01

110

Supplemental Technical Data Summary M-Area Groundwater Investigation  

SciTech Connect

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

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

1995-10-01

111

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

SciTech Connect

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.

Not Available

1992-09-01

112

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

SciTech Connect

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.

Not Available

1992-09-01

113

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

SciTech Connect

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.

Not Available

1993-03-01

114

A dechlorination pathway for synthesis of horn shaped carbon nanotubes and its adsorption properties for CO2, CH4, CO and N2.  

PubMed

Using metallic copper as reductant and tetrachloroethylene as carbon precursor, a simple, low temperature solvothermal method for the synthesis of horn shaped carbon nanotubes is reported. The detail study of reaction parameters such as temperature, time, carbon precursor amount, type and catalyst proportion has been carried out to optimize the conditions wherein that the copper metal (10 g) mediated reduction of tetrachloroethylene (25 mL) at 200°C for 5h resulted in the horn shaped carbon nanotubes with high yield and structural selectivity. The adsorption properties of horn shaped carbon nanotubes were investigated for carbon dioxide, methane, carbon monoxide and nitrogen as adsorbate by volumetric measurements up to 850 mm Hg. The prepared horn shaped carbon nanotubes showed good adsorption capacity for CO(2) (45 cm(3)/g) and CO (17 cm(3)/g), at 303 K and 850 mm Hg pressure, with high equilibrium selectivity (73.3 for CO(2) and 110.7 for CO at 318 K) and capacity selectivity (9.1 for CO(2) and 3.1 for CO at 850 mm Hg and 318 K) over nitrogen which provides the tool for the separation of CO(2) from its mixture with nitrogen observed in flue gas of thermal power plants and boilers, as well as with CO such as syngas. PMID:22682801

Sawant, Sandesh Y; Somani, Rajesh S; Bajaj, Hari C; Sharma, Sangita S

2012-08-15

115

In situ measurement of volatile organic compounds in groundwater by methods coupled to the cone penetrometer  

SciTech Connect

The objective of this investigation is to interface an in situ, on-line sparging system with a cone penetrometer to provide direct analysis of volatile organic compounds (VOCS) in groundwater by on-site analysis. Transfer line materials (15 m {times} 0.160--0.216 cm ID) composed of stainless steel, nickel, aluminum and Teflon{reg_sign}PFA, PTFE, and FEP were evaluated for their ability to quantitatively transfer chloroform, 1,1,1-trichloroethane, carbon tetrachloride, tetrachloroethylene, n-hexane, benzene, toluene, and o-xylene in the gas phase. The water content of the gas stream had an insignificant effect on the quantitative transfer of VOCs through Teflon{reg_sign} tubing but was critical to quantitative transfer of the compounds through metal tubing, particularly for nickel. Transfer efficiencies for all 7 analytes in moist gas streams through stainless steel tubing were greater than 95%. Toluene, tetrachloroethylene, and o-xylene were transferred with 93, 81 and 80% efficiency, respectively when drawn through Teflon{reg_sign}PFA tubing at 25 C. The sorption of these VOCs by Teflon{reg_sign} tubing was reversible and their transfer efficiencies improved to 94% when the tubing was flushed with 16 equivalent volumes of air. In general, the retention of the VOCs by Teflon{reg_sign} increased with decreasing aqueous solubility of the analyte. The efficiency at which VOCs were sparged from aqueous standards in Teflon{reg_sign}PFA, Type 304 stainless steel, and glass vessels were similar.

Doskey, P.V.; Aldstadt, J.H.; Kuo, J.M.; Costanza, M.S.; Erickson, M.D. [Argonne National Lab., IL (United States). Environmental Research Div.

1995-03-01

116

Mixed Waste Management Facility groundwater monitoring report. Second quarter 1994  

SciTech Connect

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.

Chase, J.A.

1994-09-01

117

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

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.

Williams, Shannon D.; Aycock, Robert A.

2001-01-01

118

Volatile organic compounds in 600 US homes: major sources of personal exposure  

SciTech Connect

The USEPA carried out the Total Exposure Assessment Methodology (TEAM) Study (1980-85) on 600 subjects in five cities representing a total population of more than 700,000 persons. Personal exposures to all prevalent target compounds exceeded outdoor concentrations. Major sources were smoking (benzene, styrene, xylenes, and octane); using hot water (chloroform); wearing dry-cleaned clothes (tetrachloroethylene); and using moth crystals or room air deodorants (para-dichlorobenzene). Eleven of 14 occupations also showed elevated exposures to one or more chemicals (particularly aromatics). Auto related activities (lengthy commuting, filling gas tanks) were associated with increased exposures to several aromatics. Breath concentrations were significantly associated with personal air exposures but not with outdoor concentrations. Residence in major chemical-manufacturing and petroleum-refining areas did not significantly affect personal exposures.

Wallace, L.; Clayton, C.A.

1987-05-01

119

Mixed Waste Management Facility (MWMF) groundwater monitoring report  

SciTech Connect

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.

Thompson, C.Y.

1992-06-01

120

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

SciTech Connect

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.

Thompson, C.Y.

1992-06-01

121

Mixed Waste Management Facility groundwater monitoring report, First quarter 1994  

SciTech Connect

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.

Not Available

1994-06-01

122

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

SciTech Connect

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.

Not Available

1993-12-01

123

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

SciTech Connect

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.

Butler, C.T.

1994-03-01

124

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

SciTech Connect

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.

NONE

1996-03-01

125

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

SciTech Connect

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.

Not Available

1993-06-01

126

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

SciTech Connect

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.

NONE

1997-03-01

127

Catalytic incineration of chlorocarbons  

SciTech Connect

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.

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

1993-12-31

128

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

SciTech Connect

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.

Not Available

1994-02-01

129

Health assessment for Centre County Kepone, State College, Centre County, Pennsylvania, Region 3. CERCLIS No. PAD000436261. Preliminary report  

SciTech Connect

The Centre County Kepone site is an active chemical manufacturing plant that produced Kepone and Mirex from the 1950s until the 1970s. Wastes were stored in a lagoon and drum storage area. The lagoon waste was chemically stabilized and buried. However, the waste did not solidify properly, and hazardous materials presently are leaching into the groundwater and surface water. The environmental contamination on-site consists of toxaphene, trichloroethylene, benzene, chlorobenzene, carbon tetrachloride, and chrysene in groundwater; and polynuclear aromatic hydrocarbons, including benzo(a)pyrene in sediment. The environmental contamination off-site consists of benzene, chlorobenzene, dichloroethane, trichloroethylene, and tetrachloroethane in surface water; chrysene in drainage ditch sediment; and tetrachloroethylene in groundwater. 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, sediment, soil, and fish.

Not Available

1988-12-02

130

Health assessment for Pinnette's Salvage Yard Site, Washburn, Aroostook County, Maine, Region 1. CERCLIS No. MED980732291. Preliminary report  

SciTech Connect

The Pinette's Salvage Yard Site (PSY) is on the National Priorities List. In 1979, three transformers were dismantled leaking polychlorinated biphenyls (PCB's) and chlorobenzene on-site. Preliminary on-site sampling results have demonstrated 1,3 dichlorobenzene and 1,4 dichlorobenzene in groundwater, and PCB's, 1,2,4-trichlorobenzene, 1,2 dichlorobenzene, toluene, ethylbenzene, chlorobenzene, xylene, and tetrachloroethylene in soil. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of human exposure to hazardous substances. Unauthorized persons having access to the site and/or those having direct contact with on-site soil and sediment are at risk of exposure.

Not Available

1989-04-20

131

Treatment of VOCs in high strength wastes using an anaerobic expanded-bed GAC reactor  

SciTech Connect

The potential of the expanded-bed granular activated carbon (GAC) anaerobic reactor in treating a high strength waste containing RCRA volatile organic compounds (VOCs) was studied. A total of six VOCs, methylene chloride, chlorobenzene, carbon tetrachloride, chloroform, toluene and tetrachloroethylene, were fed to the reactor in a high strength matrix of background solvents. Performance was evaluated. The reactor was found to effect excellent removal of all VOCs (97%). Chloroform, while itself removed at levels in excess of 97%, was found to inhibit the degradation of acetate and acetone, two of the background solvents. Without any source of chloroform in the feed, excellent COD removals were obtained in addition to near-complete removal of all the VOCs.

Narayanian, B.; Suidan, M.T.; Gelderloos, A.B.; Brenner, R.C.

1993-01-01

132

Ambient air sampling with portable gas chromatographs  

SciTech Connect

A Photovac 10S50 portable photoionization gas chromatograph mounted in a small automobile was used to sample air for organic vapors in Richmond and Hopewell, Virginia and in Staten Island, NY. A methylphenylsilicone column of 1.5-micrometer phase thickness was used with no backflush, and a 10 part per billion mixture of tetrachloroethylene in nitrogen was used as a field recalibration standard. Calibrant contamination of the unit was minimal, and background levels of compounds for which the unit was calibrated below 0.5 part per billion could be observed. These compounds were chlorobenzene, ethylbenzene, o-xylene, m-xylene, and bromobenzene. Large releases of benzene, toluene, and several compounds for which the unit had not been calibrated were observed.

Berkley, R.E.

1988-05-01

133

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

SciTech Connect

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.

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

1990-01-01

134

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

SciTech Connect

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.

NONE

1996-09-17

135

FTIR investigation of adsorption and chemical decomposition of CCl4 by high surface-area aluminum oxide.  

PubMed

Chlorinated hydrocarbons are among the most recalcitrant pollutants for control by sorption or catalytic destruction. High surface-area alumina holds promise as a catalytic media as well as a component of other binary catalyst systems. We have prepared an alumina catalyst using the aerogel technique that has a very high surface area of 550 m2/g. This catalyst destroys carbon tetrachloride with an efficiency >99% at 400 degrees C. Its reactivity toward carbon tetrachloride is remarkably higher than that of commercial alumina, which has a surface area of 155 m2/g. Carbon dioxide is the major product. Minor products include hydrogen chloride and tetrachloroethylene along with traces of phosgene. Some of the carbon tetrachloride reacts with the alumina to form aluminum chloride, which vaporizes to reveal a fresh catalytic surface. A mechanism for adsorption and destruction has been developed that involves chemisorption followed by surface to adsorbate oxygen transfer and adsorbate to surface chlorine transfer. PMID:11999074

Khaleel, Abbas; Dellinger, Barry

2002-04-01

136

Bioremediation of contaminated groundwater  

DOEpatents

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.

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

1995-01-01

137

Health assessment for Aerojet-General Corporation, Rancho Cordova, Sac Ramento County, California, Region 9. CERCLIS No. CAD980358832. Preliminary report  

SciTech Connect

The Aerojet-General Corporation site is on the National Priorities List. Since the 1950s, Aerojet-General has manufactured liquid and solid propellent rocket engines for military and commercial applications, and has formulated a number of chemicals. The environmental contamination on-site (maximum concentrations reported) consists of trichloroethylene (12 ppm), toluene (4.2 ppm), chloroform (100 ppm), and methylene chloride (5.9 ppm) in ground water; and 1,1-dichloroethane (1.6 ppm), 1,1,1-trichloroethane (1.8 ppm), carbon tetrachloride (1 ppm), and tetrachloroethylene (0.6 ppm) in surface water. The site is considered to be of potential public health concern because of the risk to human health caused by the likelihood of exposure to hazardous substances via contaminated ground water.

Not Available

1988-12-05

138

Use of a 2-inch, dual screen well to conduct aquifer tests in the upper and lower Lost lake aquifer zones: Western sector, A/M area, SRS  

SciTech Connect

The Western Sector, A/M Area is located just west of the M-Area Settling Basin on an upland area. The area is adjacent to the gently inclined area where the upland drops off to the Savannah River floodplain. Water in the parts of the uppermost aquifers contains dissolved contaminants which originated at the land surface and have leached downward into the groundwater. Subsurface contamination originated in the locality of the M-Area Settling Basin and Lost Lake, which is a Carolina Bay. These locations functioned as disposal sites for industrial solvents during the early years of operation of the Savannah River Site. The primary groundwater contaminants are trichloroethylene (TCE) and tetrachloroethylene (PCE), and groundwater concentrations of TCE are significantly greater than the PCE.

Hiergesell, R.A.; Novick, J.S.

1996-09-01

139

Analysis and evaluation of VOC removal technologies demonstrated at Savannah River  

SciTech Connect

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.

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

140

Method for detecting toxic gases  

DOEpatents

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.

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

1991-10-08

141

TNX-Area groundwater monitoring report. 1993 Annual report  

SciTech Connect

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.

Not Available

1994-05-01

142

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

SciTech Connect

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.

Brigmon, R..L.

2004-01-30

143

Superfund record of decision (EPA Region 10): Teledyne Wah Chang Albany Site, Millersburg, OR, June 1994  

SciTech Connect

This decision document presents the selected remedial actions for the Teledyne Wah Chang Albany Site (Site or TWCA Site), in Millersburg, Linn County, Oregon. The remedial actions described below are the final response actions planned for the groundwater and sediments operable unit at the Site. Teledyne Wah Chang Albany is an active operating facility which primarily manufactures zirconium metal from zircon sands. The processing of the zircon sands generates sludge, waste water, residues and gases as by-products. The cleanup actions described in this ROD address the threats to groundwater and sediment posed by radionuclides, metals, polychlorinated biphenyls (PCBs), methyl isobutyl ketone (MIBK), thrichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, and other contaminants at the Site.

Not Available

1994-06-10

144

Air stripping of volatile organic chlorocarbons: System development, performance, and lessons learned  

SciTech Connect

The Savannah River Site, which has been in operation since the 1950`s, is a 780-square kilometer reservation that produces tritium for the national defense program. As a result of past waste handling practices, the ground water at several locations on the Site has become contaminated with solvents, metals, and radionuclides. In 1981, the ground water located under the Site`s fuel and target rod fabrication area (M-Area) was found to be contaminated with degreasing solvents, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE). In 1983, a program was started to evaluate air stripping and determine its applicability to cleanup of M-Area contamination. Lessons learned regarding the efficiency and effectiveness of air stripping technology are presented.

McKillip, S.T.; Sibley, K.L.; Horvath, J.G.

1991-12-31

145

Characterization of nanocarbons (nanotubes and nanofibers) by Inverse Gas Chromatography  

NASA Astrophysics Data System (ADS)

The adsorption of different alkanes (linear and cyclic), aromatics and chlorohydrocarbons on non-microporous carbons-carbon nanotubes (CNTs) and carbon nanofibres (CNFs)- was studied in this work by inverse gas chromatography (IGC). Capacity of adsorption was derived from the isotherms of adsorption, whereas thermodynamic properties (enthalpy of adsorption, surface free energy characteristics) have been determined from chromatographic retention data. CNTs present the highest adsorption capacity. From surface free energy data, enthalpies of adsorption of polar compounds were divided into dispersive and specific contributions. The interactions of cyclic (benzene and cyclohexane) and chlorinated compounds (trichloroethylene, tetrachloroethylene and chloroform) with the surfaces are mainly dispersive over all the carbons tested, being CNTs the material with the highest dispersive contribution. Adsorption parameters were correlated with morphological and chemical properties of the materials.

Díaz, E.; Ordóñez, S.; Vega, A.

2007-04-01

146

TNX Area 1994 Annual Groundwater Monitoring Report  

SciTech Connect

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.

Chase, J.A.

1995-05-01

147

Analysis of organic compounds (VOC) in the forest air of the Southern Black Forest  

SciTech Connect

The volatile organic compounds of forest air (Kaelbelescheuer, Southern Black Forest) and, for comparison, suburban air (Tuebingen) were qualitatively analyzed by gas chromatographic and mass spectrometric methods. 94 Individual compounds were identified, 6 of them belonged to biogenic monoterpenes (..cap alpha..-pinene, ..delta..3-carene, myrcene, limonene, eucalyptol, camphene). While the monoterpenes were enriched in forest air, a similar collection of the pollution products was observed in both locations. Predominant substances were aromatic compounds (toluene, ethylbenzene, benzene, xylenes, ethyltoluenes, pseudocumene and naphthalene) which can be regarded as constituents of vehicle exhaust fumes and incineration processes. Other important substances in forest air were various solvents, of which butyl acetate, isobutyl acetate, tetrachloroethylene and trichloroethylene, butanol-1, and several ketones were prominent species.

Juettner, F.

1986-01-01

148

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

SciTech Connect

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.

NONE

1995-02-01

149

Transformations of trace halogenated aliphatics in anoxic biofilm columns  

NASA Astrophysics Data System (ADS)

The transformability of trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dibromoethane, tetrachloroethylene, hexachloroethane, and dibromochloropropane was studied under conditions of denitrification, sulfate respiration, and methanogenesis. These compounds at concentrations commonly found in groundwater were continuously administered to anoxic biofilm columns that resembled groundwater environments. Acetate was the primary substrate to support microbial growth. All of the compounds studied were transformed under methanogenesis. Bromoform, bromodichloromethane, carbon tetrachloride, and hexachloroethane were transformed even under the less reducing conditions of denitrification. Some of the compounds were partially mineralized to CO2. However, reductive dehalogenation appeared to be the predominant mechanism for removal. Characterization of the available electron acceptors in the subsurface is important for assessing organic micropollutant biotransformation. Reaction rates observed in the laboratory biofilms indicate that biotransformation could be responsible for significant removals of these halogenated compounds in the subsurface.

Bouwer, Edward J.; Wright, John P.

1988-03-01

150

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

SciTech Connect

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.

Not Available

1994-09-01

151

Intercomparison of sampling techniques for toxic organic compounds in indoor air. Final report, March 1985-September 1986  

SciTech Connect

People spend a major fraction of their time indoors, and there is concern over exposure to volatile organic compounds present in indoor air. The study was initiated to compare several VOC sampling techniques in an indoor environment. The techniques which were compared include distributive air volume sampling, high- and low-rate passive sampling, and whole air collection in canisters. The study focused on ten target compounds: chloroform, 1,1,1-trichloroethane, benzene, bromodichloromethane, trichloroethylene, toluene, tetrachloroethylene, styrene, p-dichlorobenzene, and hexachlorobutadiene. Altogether, ten separate 12-hour sampling experiments were conducted. Two experiments sampled the background air of the residence. For the other eight experiments, the indoor air was spiked with the target compounds. Statistical analysis of the results indicates generally high correlation coefficients (greater than 0.90) between the methods. The most notable exception was benzene, which had lower correlation coefficients. In general, the distributed air volume sampling technique measure concentrations less than or equal to the canister method.

Spicer, C.W.; Holdren, M.W.; Slivon, L.E.; Coutant, R.W.; Shadwick, D.S.

1987-03-01

152

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

SciTech Connect

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.

Not Available

1993-06-01

153

On-line liquid-liquid extraction in a segmented flow directly coupled to on-column injection into a gas chromatograph  

SciTech Connect

A mechanized system for extractive sample workup for gas chromatography coupled on-line to an on-column injector is described. Extraction is performed in a liquid-liquid segmented flow in a glass coil internally coated with a hydrophobic layer. After extraction the phases are separated with the aid of a hydrophobic membrane supported by a screen coated with Teflon. The organic phase is fed to a loop injector. The system is closed from the atmosphere and was proven to provide rapid and precise workup of seawater samples of the determination of the halocarbons chloroform, bromodichloromethane, dibromochloromethane, bromoform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, and 1,1,1-trichloroethane. Compared to manual extraction, smaller volumes of sample and organic phase are needed. Reliability was tested during a 3-week cruise when 350 seawater samples were processed without system failure. Concentrations down to the picogram-per-liter level in water can be determined, using injection volumes up to 130 /sup +/L.

Fogelqvist, E.; Krysell, M.; Danielsson, L.G.

1986-06-01

154

Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. First quarter 1995  

SciTech Connect

During first quarter 1995, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, field measurements, 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). Total organic halogens exceeded its Savannah River Site (SRS) Flag 2 criterion during first quarter 1995 as in fourth quarter 1994. Aluminum, iron, and manganese, which were not analyzed for during fourth quarter 1994, exceeded the Flag 2 criteria in at least two wells each during first quarter 1995. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting the 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.

NONE

1995-06-01

155

Health assessment for Powell Road Landfill, Dayton, Montgomery County, Ohio, Region 5. CERCLIS No. OHD000382663. Preliminary report  

SciTech Connect

The Powell Road Landfill site is listed on the National Priorities List. The 67-acre site began operation in 1959 as a municipal landfill after being used as a gravel pit for an unspecified period of time. The environmental contamination on-site consists of benzidine, benzene (5 ppb), trichloroethylene, trans- 1,2-dichloroethylene (78 ppb), styrene (16 ppb), tetrachloroethylene (29 ppb), ethylbenzene (88 ppb), toluene (757 ppb), xylenes (257 ppb), methylene chloride (14 ppb), chloroethane (28 ppb), phenol (202 ppb), methyl ethyl ketone, chloroform, 1,2-dichloroethane, 1,2-dichlorobenzene (34 ppb), bromodichloromethane, and strontium chromate. Based on the available information, 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 ground water.

Not Available

1989-01-17

156

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

SciTech Connect

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.

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

1994-08-01

157

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

SciTech Connect

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.

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

1998-02-01

158

Health assessment for Olmsted County Sanitary Landfill, Oronoco Township, Minnesota, Region 5. CERCLIS No. MND000874354. Preliminary report  

SciTech Connect

Olmsted County Sanitary Landfill is listed on the National Priorities List. The landfill is in Olmsted County in southeastern Minnesota and was owned and operated by the City of Rochester. The landfill accepted much hazardous material, including electroplating sludge, asbestos, transformers, and paint and solvents. By 1984, ground water under the landfill was heavily contaminated with leachate from the pile. Representative contamination found in the monitoring wells include 1,1,2,2-tetrachloroethylene, trichloroethylene, chloroform, methylene chloride, tetrahydrofuran, methyl ethyl ketone, chloromethane, ethylbenzene, toluene, trans-1,2-dichloroethylene, 1,1-dichloroethylene, 1,2-dichloroethane, dichlorobenzene, benzene, and xylenes. 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 the ground water.

Not Available

1989-06-27

159

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

SciTech Connect

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.

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

2003-08-01

160

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

NASA Astrophysics Data System (ADS)

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.

Glajar, Ioana C.; Moldovan, Z.

2009-08-01

161

Operations Support of Phase 2 Integrated Demonstration In Situ Bioremediation. Volume 1, Final report: Final report text data in tabular form, Disk 1  

SciTech Connect

This project was designed to demonstrate in situ bioremediation of ground water and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade trichlorethylene (TCE), tetrachloroethylene (PCE) 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 (natural gas). 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. This report describes the preliminary results of the demonstration and provides conclusions only for those measures that the Bioremediation Technical Support Group felt were so overwhelmingly convincing that they do not require further analyses. Though this report is necessarily superficial it does intend to provide a basis for further evaluating the technology and for practitioners to immediately apply some parts of the technology.

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

1993-09-01

162

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

NASA Astrophysics Data System (ADS)

Aluminum nitrate activity coefficients obtained by vapor pressure osmometry are compared with activity coefficients derived from nitric acid extraction measurements and Bromley's correlation. This solvent extraction approach was possible because of the poor extraction of Al 3+ (distribution ratio ? 10 3) by the chosen solvents. The solvents compositions were 0.25M CMPO (octyl(phenyl)-N, N-diisobutylcarbamoyl methylphosphine oxide) in tetrachloroethylene (TCE) and 0.25M CMPO with 0.75M tributyl phosphate (TBP) in TCE. In both approaches, nitric acid was used to supress the hydrolysis of Al 3+. At high ionic strengths, the two techniques yielded very similar activity coefficients for Al(NO 3) 3. However, at intermediate and very low ionic strengths, the two procedures produced considerably different activity coefficients.

Chaiko, D. J.; Tasker, I. R.; Fredrickson, D. R.; Difilippo, A. A.; Smidt, S. M.; Vandegrift, G. F.

163

Bioremediation of contaminated groundwater  

DOEpatents

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.

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

1995-01-24

164

Ground-water contamination in East Bay Township, Michigan  

USGS Publications Warehouse

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)

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

1985-01-01

165

Physiological characterization of a broad spectrum reductively dechlorinating consortium  

USGS Publications Warehouse

A wetland sediment-derived microbial consortium (WBC-2) was developed by the US Geological Survey and propagated in vitro to large quantities by SiREM Laboratory for potential use in bioaugmentation applications. On the basis of bench-scale tests, the consortium could completely dechlorinate 1,1,2,2-tetrachloroethylene, tetrachloroethylene, trichloroethylene, 1,1,2-trichloroethane, cis- and trans-1,2-dichoroethylene, 1,1-dichloroethylene, 1,2-dichloroethane, and vinyl chloride in culture medium. Batch microcosms were carried out under anaerobic conditions in culture medium with neutral pH and with pH adjusted from acidic (pH 4, 5, and 6) to alkaline (pH 8 and 9). To evaluate oxygen sensitivity of WBC-2, an aliquot was removed from an anaerobic culture vessel and poured into smaller containers on the bench top where a series of oxygen exposures were applied to the culture by bubbling ambient air through the culture at a rate of ??? 100 mL/min. Chlorinated methanes tended to inhibit activity of a wide range of microorganisms. Although toxicity effects from CT addition were observed with WBC-2 in liquid culture at 3 mg/L concentration, WBC-2 in the columns could maintain degradation of CT and chloroform (CF) and of the chlorinated ethanes and ethylenes at CT and CF concentrations of 10 and 20 mg/L, respectively. This is an abstract of a paper presented at the Proceedings of the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

Lorah, M.M.; Majcher, E.; Jones, E.; Driedger, G.; Dworatzek, S.; Graves, D.

2005-01-01

166

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

SciTech Connect

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.

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

1994-05-01

167

In situ measurement of volatile organic compounds in groundwater by methods coupled to the cone penetrometer  

SciTech Connect

The objective of this investigation was to interface an in situ, on-line sparging system with a cone penetrometer to provide direct analysis of volatile organic compounds (VOCS) in groundwater by on-site analysis. Transfer lines (15 m x 0.160- to 0.216-cm ID) composed of stainless steel, nickel, aluminum and Teflon{reg_sign} PFA, PTFE, and FEP were evaluated for their ability to quantitatively transfer chloroform, 1,1,1-trichloroethane, carbon tetrachloride, tetrachloroethylene, n-hexane, benzene, toluene, and o-xylene in the gas phase at 25 C. The water content of the gas stream had an insignificant effect on the quantitative transfer of VOCs through Teflon{reg_sign} tubing but was critical to efficiently transfer the compounds through metal tubing, particularly nickel. Transfer efficiencies for all eight analytes in moist gas streams through stainless steel tubing were greater than 95%. Toluene, tetrachloroethylene, and o-xylene were transferred with 93, 81, and 80% efficiency, respectively, when they were drawn through Teflon{reg_sign} PFA tubing at 25 C. The sorption of these VOCs by Teflon{reg_sign} tubing was reversible, and their transfer efficiencies improved to 94% when the tubing was flushed with 16 equivalent volumes of air. In general, the retention of the VOCs by Teflon{reg_sign} increased with decreasing aqueous solubility of the analyte. The efficiencies at which VOCs were sparged from aqueous standards in Teflon{reg_sign} PFA, Type 304 stainless steel, and glass vessels were similar.

Doskey, P.V.; Aldstadt, J.H.; Kuo, J.M.; Costanza, M.S.; Erickson, M.D. [Argonne National Lab., IL (United States). Environmental Research Division

1995-12-31

168

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

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

2013-01-01

169

Dodecyl sulfate-hydrotalcite nanocomposites for trapping chlorinated organic pollutants in water.  

PubMed

A series of hybrid organic-inorganic nanocomposite materials was synthesized by three different procedures using sodium dodecyl sulfate (DDS) and magnesium-aluminum layered double hydroxide (Mg/Al LDH with a Mg/Al molar ratio of 2 to 5). Both the pH of the exchange medium (6.5 to 10) and the Mg/Al molar ratio of the LDH affected the basal spacing, the content of DDS retained and the orientation of the DDS chains within the interlamellar space. For LDH with higher charge density (Mg/Al=2 and 3), DDS molecules likely formed a perpendicular monolayer within the LDH interlayer and the solution pH had little effect on the basal spacing, with a mean and standard deviation of 25.5+/-0.4 A. However, for LDH with lower charge density (Mg/Al=4 and 5), DDS molecules more likely formed an interpenetrating bilayer, and the basal spacing significantly increased with increasing pH, with a mean and standard deviation of 32.7+/-5.2 A. Sorption of trichloroethylene and tetrachloroethylene by DDS-LDH varied with synthesis conditions, LDH type and DDS configuration in the interlayer. DDS-Mg(3)Al-LDH had the highest affinity for both trichloroethylene and tetrachloroethylene in water, either comparable to or as much as four times higher than other clay-derived sorbents, followed by DDS-Mg(4)Al-LDH and DDS-Mg(5)Al-LDH. DDS-Mg(2)Al-LDH had the lowest sorption affinity although the highest amount of DDS. The pH of the exchange solution also affected the amount of DDS retained by the LDH as well as the sorption efficiency. Mg(3)Al-LDH has a charge equivalent area of 32.2 A(2)/charge, which allows the formation of optimal DDS configuration within its interlayer, thus resulting in the highest affinity for the chlorinated compounds. The DDS-Mg/Al-LDHs can be easily synthesized either ex situ or in situ at low temperature, indicating the feasibility of practical applications. The results obtained by controlling the synthesis procedure suggest that different arrangements of DDS molecules in the LDH interlayers can be obtained and optimized for the sorption of specific sorbates. PMID:15144837

Zhao, Hongting; Nagy, Kathryn L

2004-06-15

170

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

USGS Publications Warehouse

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.

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

1999-01-01

171

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

PubMed

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

Sutton, Patrick T; Ginn, Timothy R

2014-12-15

172

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

PubMed

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/m(3) 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

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

173

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

NASA Astrophysics Data System (ADS)

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.

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

1986-06-01

174

Inspection and monitoring plan, contaminated groundwater seeps 317/319/ENE Area, Argonne National Laboratory  

SciTech Connect

During the course of completing the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) in the 317/319/East-Northeast (ENE) Area of Argonne National Laboratory-East (ANL-E), groundwater was discovered moving to the surface through a series of groundwater seeps. The seeps are located in a ravine approximately 600 ft south of the ANL-E fence line in Waterfall Glen Forest Preserve. Samples of the seep water were collected and analyzed for selected parameters. Two of the five seeps sampled were found to contain detectable levels of organic contaminants. Three chemical species were identified: chloroform (14--25 {micro}g/L), carbon tetrachloride (56--340 {micro}g/L), and tetrachloroethylene (3--6 {micro}g/L). The other seeps did not contain detectable levels of volatile organics. The nature of the contaminants in the seeps will also be monitored on a regular basis. Samples of surface water flowing through the bottom of the ravine and groundwater emanating from the seeps will be collected and analyzed for chemical and radioactive constituents. The results of the routine sampling will be compared with the concentrations used in the risk assessment. If the concentrations exceed those used in the risk assessment, the risk calculations will be revised by using the higher numbers. This revised analysis will determine if additional actions are warranted.

NONE

1996-10-11

175

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

SciTech Connect

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.

NONE

1996-10-01

176

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

SciTech Connect

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.

Thompson, C.Y.

1993-03-01

177

Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report  

SciTech Connect

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.

Thompson, C.Y.

1993-03-01

178

Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report: First quarter 1992  

SciTech Connect

During first quarter 1992, 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility (Metlab HWMF) at Savannah River Plant were visited for sampling. Groundwater samples were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. This report describes the results that exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) and the Savannah River Site flagging criteria during the quarter. Tetrachloroethylene exceeded the PDWS in wells AMB 4A, 5, and 7A; trichloroethylene exceeded the PDWS in wells AMB 4A, 4B, 4D, 5, and 7A; and total alpha-emitting radium (radium-224 and radium-226) exceeded the PDWS in well AMB 5. Total organic halogens exceeded the Flag 2 criterion in wells AMB 4A, 5, 6, 7A, 7B, and IODD; manganese was elevated in wells AMB 4D and TODD; iron was elevated in well AMB TODD; and pH was elevated in well AMB 10A.

Thompson, C.Y.

1992-06-01

179

Henry's law constants of chlorinated solvents at elevated temperatures.  

PubMed

Henry's law constants for 12 chlorinated volatile organic compounds (CVOCs) were measured as a function of temperature ranging from 8 to 93°C, using the modified equilibrium partitioning in closed system (EPICS) method. The chlorinated compounds include tetrachloroethylene, trichloroethylene, cis-1,2-dichloroethylene, vinyl chloride, 1,1,1-trichloroethane, 1,1-dichloroethane, 1,2-dichloroethane, chloroethane, carbon tetrachloride, chloroform, dichloromethane, and chloromethane. The variation in Henry's constants for these compounds as a function of temperature ranged from around 3-fold (chloroethane) to 30-fold (1,2-dichloroethane). Aqueous solubilities of the pure compounds were measured over the temperature range of 8-75°C. The temperature dependence of Henry's constant was predicted using the ratio of pure vapor pressure to aqueous solubility, both of which are functions of temperature. The calculated Henry's constants are in a reasonable agreement with the measured results. With the improved data on Henry's law constants at high temperatures measured in this study, it will be possible to more accurately model subsurface remediation processes that operate near the boiling point of water. PMID:22071373

Chen, Fei; Freedman, David L; Falta, Ronald W; Murdoch, Lawrence C

2012-01-01

180

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

PubMed

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

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

2015-04-01

181

Neurologic illness associated with occupational exposure to the solvent 1-bromopropane--New Jersey and Pennsylvania, 2007-2008.  

PubMed

1-Bromopropane (1-BP) (n-propyl bromide) is a solvent increasingly used as a substitute for ozone-depleting chloro-fluorocarbons and similar regulated compounds. 1-BP is used in vapor and immersion degreasing operations and other manufacturing processes, and as a solvent in industries using aerosol-applied adhesives. In some states, 1-BP is used as a solvent in dry cleaning because of restrictions on use of perchloroethylene (tetrachloroethylene), a possible human carcinogen. Published studies of workers exposed to 1-BP have raised concerns about occupational health risks associated with exposure. This report describes two cases involving workers exposed to 1-BP and diagnosed with clinical manifestations of neurotoxicity. The cases, when coupled with previously reported studies of workers exposed to 1-BP, illustrate potential health risks of 1-BP exposure. Clinicians and public health professionals should be alert to potential health effects among workers exposed to 1-BP, particularly in dry cleaning and other workplaces where 1-BP use might be increasing, and effective control methods to limit exposure to 1-BP should be implemented at worksites. PMID:19052528

2008-12-01

182

Test plan for single well injection/extraction characterization of DNAPL  

SciTech Connect

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.

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

1995-12-01

183

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

SciTech Connect

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.

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

184

[Rapid detection of chlorinated organic mixture by laser Raman spectroscopy].  

PubMed

In order to realize the rapid, nondestructive detection of organic compounds, a two-dimensional analysis method based on technology of laser Raman spectroscopy was proposed. The results show that using 532 nm laser as excitation light source, the observation of 236.2, 348.9, 449.4 and 513.6 cm(-1), the four vibrational Raman spectra, and the intensity ratio of 6.4 : 1.7: 9.4 : 1.0 can determine the existence of tetrachloroethylene. The observation of 707.5, 1 087.9, 1 175.8 and 3 078.6 cm(-1), the four vibrational Raman spectra, and the intensity ratio of 9.6 : 6.4 : 1.0 : 3.9 can determine the existence of chlorobenzene. In other words, that through the comprehensive study of spectral lines and intensity ratio of some spectral lines, the presence of organic compounds in the mixed solution can be determined quickly. In the aspect of quantitative analysis, using multi-spectral analysis combined with least square fitting method can improve the reliability of the measurement, The accuracy of sample concentration was 98.4%. This spectral measurement method is a potential tool for organic component identification and concentration analysis which has a prosperous application prospects. PMID:25269297

Ma, Jing

2014-07-01

185

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

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.

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

2012-01-01

186

Steam reforming of DOE complex waste simulants  

SciTech Connect

Sandia National Laboratories has worked with Synthetica Technologies and Manufacturing and Technology Conversion International (MTCl) to demonstrate the applicability of their commercial steam reforming technologies for treating DOE low-level mixed wastes. Previously, Synthetica successfully demonstrated destruction of a Sandia formulated lab trash simulant. During November 1994 Synthetica did not adequately process the aqueous halogenated organic liquid mixed waste simulant (MWTP-2110) formulated by the DOE Mixed Waste Integrated Program (MWIP). Testing at MTCl is ongoing and initial results appear to be favorable. Approximately 200 lbs each of the MWIP aqueous halogenated organic liquids (MWTP-2110), and absorbed aqueous and organic liquids (MWTP-3113/3114) simulants have been processed. At 1650{degree}F, destruction efficiencies of greater than 99% were obtained for tetrachloroethylene, toluene, and 1,2 dichlorobenzene. Product cases consisted primarily of H{sub 2}, C0{sub 2}, CO, and CH{sub 4} and had higher heating values of up to 355 BTU/SCF. Conclusions concerning the suitability of the MTCI process for treating DOE mixed wastes will be drawn upon the completion of testing.

Miller, J.E.; Kuehne, P.B.

1995-03-01

187

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

NASA Astrophysics Data System (ADS)

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.

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

2009-05-01

188

An evaluation of employee exposure to volatile organic compounds in three photocopy centers.  

PubMed

Personal and area samples from three copy centres were collected in thermal desorption tubes and analyzed using gas chromatography-mass spectrometry. Real-time personal total volatile organic compounds (TVOC) were measured using a data-logging photoionization detector. Fifty-four different VOCs were detected in the area samples. The maximum concentration measured was 1132.0 ppb (toluene, copy center 3, day 1). Thirty-eight VOCs were detected in the personal samples and concentrations ranged from 0.1 ppb (1,1-biphenyl, p-dichlorobenzene, propylbenzene, styrene, and tetrachloroethylene) to 689.6 ppb (toluene). Real-time TVOC measurements indicated daily fluctuations in exposure, ranging from <71 to 21,300 ppb. The time-weighted average exposures for the photocopier operators on days 1 and 2 were 235 and 266 ppb and 6155 and 3683 ppb, in copy centers 2 and 3, respectively. Personal exposure measurements of individual VOCs were below accepted occupational standards and guidelines. For example, the maximum concentration was 0.3% of the permissible exposure limits (toluene, copy center 3). Exposures were highest in copy center 3; this is likely due to the presence of offset printing presses. It is concluded that photocopiers contribute a wide variety of VOCs to the indoor air of photocopy centers; however, exposures are at least 100 times below established standards. PMID:10856189

Stefaniak, A B; Breysse, P N; Murray, M P; Rooney, B C; Schaefer, J

2000-06-01

189

Synergistic and antagonistic effects on genotoxicity of chemicals commonly found in hazardous waste sites  

SciTech Connect

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. The chemicals were mixed in ratios of 1:1, 1:2 and 2:1 for mixtures of two chemicals and 1:1:1 each for three chemicals. The concentration of stock solution of these chemicals was around the minimum effective dose (MED) or below the MED for these chemicals as reported by Sandhu et al. (1989). Treatments were applied to plant cuttings by hydroponic uptake of the mixed solutions through the stems of the plant for 30 h followed by fixation of the flower buds in aceto-alcohol (1:3 ratio) without a recovery period. Microslides were prepared for scoring MCN frequencies. Results of two series of repeated experiments indicated that all mixtures of LTA/ATO exhibited antagonistic effects. On the other hand, all mixtures of TCE and DED exhibited synergistic effect. These data indicate that for evaluating biological hazards at chemical waste sites, it is prudent to evaluate the genotoxicity of complex chemical mixtures as these exist in nature because the biological effects based on evaluating individual chemicals may not be true predictors of the interactive effects of the pollutants.

Ma, T.H.; Sandhu, S.S.; Peng, Y.; Chen, T.D.; Kim, T.W.

1992-01-01

190

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

SciTech Connect

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.

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

2007-01-10

191

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS  

SciTech Connect

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.

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

2002-06-01

192

Use of sonication for in-well softening of semivolatile organic compounds. 1998 annual progress report  

SciTech Connect

'This project investigates the in-situ degradation of semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) using in-well sonication, in-well vapor stripping, and biodegradation. The project has the primary objectives of developing this integrated system for efficient and economical removal and degradation of SVOCs and VOCs from groundwater. The project has as its goal the partial degradation (softening) of the more recalcitrant organic compounds in order to convert them into compounds that are more amenable to both air sparging and biological treatment. By performing the softening in-well, the treated organics can be reinjected and percolated through the subsurface, thereby enhancing biodegradation by generating organics that are more easily biodegraded. This report summarizes work after nearly 2 years of a 3-year project. Argonne National Laboratory is developing a new technology that combines in-well sonication, in-well vapor stripping, and in-situ biodegradation for removal of SVOCs and VOCs from solution. Bench-scale batch experiments have been performed investigating the separate treatment systems involving stripping and sonication of halogenated organics in groundwater, along with the combined sonication/stripping system. Organic contaminants studied include: trichloroethylene (TCE), carbon tetrachloride (CCl4 ), tetrachloroethylene (PCE), trichloroethane (TCA), and ethylene dibromide (EDB). Initial organic concentrations range from {approximately}10 to {approximately}100 mg/L. Results of the sonication and vapor stripping experiments are available upon request.'

Peters, R.W.; Manning, J.F. [Argonne National Lab., IL (US); Hoffmann, M.R. [California Inst. of Tech., Pasadena, CA (US); Gorelick, S. [Stanford Univ., CA (US)

1998-06-01

193

Use of Sonification for In-Well Softening of Semivolatile Organic Compounds  

SciTech Connect

This study examined an integrated sonication/vapor stripping system's ability to remove/destroy chlorinated organics from groundwater. Chlorinated solvents studied included carbon tetrachloride, trichloroethylene, trichloroethane and tetrachloroethylene. Contaminant concentrations ranged from {approx}1 to {approx}100 mg/L. The sonicator had an ultrasonic frequency of 20 kHz; applied power intensities were 12.3-, 25.3- and 35.8-W/cm2. Batch reactions were operated for up to 10 minutes treatment time, with samples drawn for GC analysis every 2 minutes. Batch experimental results were obtained using sonication, vapor stripping and combined sonication/vapor stripping. For the chlorinated solvents, the first order rate constants were in the range of 0.02 to 0.06 min-1, 0.23 to 0.53 min-1 and 0.34 to 0.90 min-1 for sonication, vapor stripping and combined sonication/vapor stripping. For the chlorinated organics (treatment time {approx}10 min.), the fraction remaining after sonication and vapor stripping ranged from 62% to 82%, while less than 3% remained from the combined sonication/vapor stripping system.

Peters, Robert W.; Manning, John L.; Ayyiliz, Onder; Wilkey, Michael L.

2003-03-26

194

Ultralow temperature synthesis and improved adsorption performance of graphene oxide nanosheets  

NASA Astrophysics Data System (ADS)

In this article, we first report an ultralow temperature (-60 °C) synthesis of graphene oxide nanosheets (GONs), which is achieved via the reduction reaction of tetrachloroethylene (C2Cl4) and potassium in liquid ammonia solution at atmospheric pressure. The as-obtained multilayer GONs with a high quality exhibit a low C/O atomic ratio of approximately 2:1, indicating that GONs are rich in the oxygen-containing functional groups. In order to improve their adsorption property, GONs are reduced at 500 °C for 2 h in flowing N2, which results in the successful preparation of graphene nanosheets (GNs) with a high C/O atomic ratio of approximately 32:1. GNs show high specific surface area (508 m2/g), high adsorption capacity (Qe = 148.36 mg/g, Co = 180 mg/L), and rapid adsorption rate (>96%, 10 min) of organic dye rhodamine B (RhB) from water, suggesting that GNs have potential environmental applications as alternatives to commercial materials in wastewater treatment for the removal of organic dye. Compared with the reported methods to prepare GONs, our techniques have attractive advantages, such as low reaction temperature and being friendly to environment.

Tao, Xiaojun; Wang, Xiaodong; Li, Zhiwei; Zhou, Shaomin

2015-01-01

195

Field test of single well DNAPL characterization using alcohol injection/extraction  

SciTech Connect

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 efficient characterization or removal of DNAPL are not currently proven. The authors performed injection/extraction characterization tests in six existing wells in A/M Area. Water concentrations for TCE and/or PCE in these wells ranged from 0% to 100% of solubility. For each test, small amounts of solubilizing solution were used to try to confirm or deny the presence or absence of DNAPL in the immediate vicinity of the well screen.

Jerome, K.M.; Looney, B.B.; Rhoden, M.L.; Riha, B.; Burdick, S. [Westinghouse Savannah River Co., Aiken, SC (United States)

1996-10-29

196

Factors affecting the adsorption of trichloroethylene onto activated carbons  

NASA Astrophysics Data System (ADS)

In this work, an experimental study aimed at the assessment of the factors affecting the adsorption of trichloroethylene (TCE) from water solutions onto activated carbons is presented. The influence of sorbent properties, such as B.E.T. surface area, micropore volume, chemical composition and acid/basic surface functional groups on TCE adsorption capacity is experimentally assessed by testing a set of 12 sorbents. Moreover, the effect of the presence of other species in solution, such as sodium acetate and tetrachloroethylene (PCE), is studied through parametric TCE adsorption isotherms realization. The experimental results show that the TCE adsorption capacity is promoted by a high B.E.T. surface area, micropore volume and C content and it is significantly affected by the presence of a non-ionic compound of similar structure (PCE), however it does not depend on the presence of an organic salt (sodium acetate). These results confirm that neither TCE-carbon ionic interaction nor sorbent ionization phenomena are involved in the TCE adsorption, since its mechanism is based on dispersion forces (London-Van Der Walls interaction). A thorough analysis of the experimental data set suggests that, in consideration of the TCE adsorption mechanism, the maximization of basal plane extent (as the B.E.T. surface area) and its effective fraction (as the C content) is a valid criterion to select or synthesize a new suitable sorbent for TCE adsorption from waters.

Erto, A.; Andreozzi, R.; Lancia, A.; Musmarra, D.

2010-06-01

197

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

SciTech Connect

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.

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

1996-09-01

198

Review of analytical results from the proposed agent disposal facility site, Aberdeen Proving Ground  

SciTech Connect

Argonne National Laboratory reviewed the analytical results from 57 composite soil samples collected in the Bush River area of Aberdeen Proving Ground, Maryland. A suite of 16 analytical tests involving 11 different SW-846 methods was used to detect a wide range of organic and inorganic contaminants. One method (BTEX) was considered redundant, and two {open_quotes}single-number{close_quotes} methods (TPH and TOX) were found to lack the required specificity to yield unambiguous results, especially in a preliminary investigation. Volatile analytes detected at the site include 1, 1,2,2-tetrachloroethane, trichloroethylene, and tetrachloroethylene, all of which probably represent residual site contamination from past activities. Other volatile analytes detected include toluene, tridecane, methylene chloride, and trichlorofluoromethane. These compounds are probably not associated with site contamination but likely represent cross-contamination or, in the case of tridecane, a naturally occurring material. Semivolatile analytes detected include three different phthalates and low part-per-billion amounts of the pesticide DDT and its degradation product DDE. The pesticide could represent residual site contamination from past activities, and the phthalates are likely due, in part, to cross-contamination during sample handling. A number of high-molecular-weight hydrocarbons and hydrocarbon derivatives were detected and were probably naturally occurring compounds. 4 refs., 1 fig., 8 tabs.

Brubaker, K.L.; Reed, L.L.; Myers, S.W.; Shepard, L.T.; Sydelko, T.G.

1997-09-01

199

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

PubMed

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

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

2014-07-01

200

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

PubMed

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

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

2011-01-01

201

Stoichiometry of Fenton`s reagent in the oxidation of chlorinated aliphatic organic pollutants  

SciTech Connect

The stoichiometry of Fenton`s reagent in the oxidation of dichloroethylene (DCE), trichloroethylene (TCE), tetrachloroethylene (tetra-CE), and dichloroethane (DCEA) by Fenton`s reagent has been investigated. The optimal ratio between H{sub 2}O{sub 2} and Fe{sup 2+} has been theoretically determined to be 11.11. The increasing degree of chlorine content of chlorinated aliphatic compounds results in decreasing oxidation reactivity of the organic compound. At the optimal ratio between H{sub 2}O{sub 2} and Fe{sup 2+} of 5 and optimal pH of 3.5, the amount of H{sub 2}O{sub 2} required for a specific percentage removal of the organic compounds depends upon the initial organic concentration to be oxidized. The accumulation of chloride ion released expressed as the total percentage chloride ion released also depends upon the initial organic concentrations. The typical percentage removal of organic compounds and percentage release of chloride ion have been studied at 100%, 70%, 50%, 40%, 30%, 20%, 10%, and 1%. The amount of H{sub 2}O{sub 2} required to achieve a certain percentage removal follows the order of TCE < Tetra-CE < DCE {much_lt} DCEA. However, the amount of chloride ion detected at the same amount of H{sub 2}O{sub 2} follows the order of DCEA {much_lt} DCE < TCE < Tetra-CE.

Tang, W.Z. [Florida International Univ., Miami, FL (United States). Dept. of Civil and Environmental Engineering; Huang, C.P. [Univ. of Delaware, Newark, DE (United States)

1994-12-31

202

Development of CFC-Free Cleaning Processes at the NASA White Sands Test Facility  

NASA Technical Reports Server (NTRS)

The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-113- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. The presentation will include the findings of investigations of aqueous cleaning and verification processes that are based on a draft of a proposed NASA Kennedy Space Center (KSC) cleaning procedure. Verification testing with known contaminants, such as hydraulic fluid and commonly used oils, established correlations between nonvolatile residue and CFC-113. Recoveries ranged from 35 to 60 percent of theoretical. WSTF is also investigating enhancements to aqueous sampling for organics and particulates. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon-225 (HCFC-225), tert-butylmethylether, and n-Hexane was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC-113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autoignition and liquid oxygen mechanical impact testing.

Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

1995-01-01

203

Use of breath monitoring in assessing exposures to volatile organic solvents  

SciTech Connect

Two techniques were developed to measure volatile organic solvents in exhaled air. The sorbent collector is a hand-held device that concentrates organic vapor(s) from mixed exhaled air on a bed of charcoal. The breath volume is measured with a Wright respirometer and the a adsorbed vapors are analyzed by gas chromatography. The alveolar air monitor is a portable gas chromatograph that collects and analyzes end-exhaled air. A comparison of the two techniques demonstrated a consistent relationship for air concentrations measured from a number of individuals exposed to styrene or tetrachloroethylene (PERC). In a study of dry cleaners, measurements of PERC in mixed exhaled air correlated with simultaneous measurements of PERC in blood and with measurements of exposure. In occupational settings, end-exhaled air measurements correlated well with exposure measurements averaged over a period of 20 minutes. This result was reproduced in chamber studies with highly autocorrelated exposure profiles. However, when the exposure profiles were purely random the relationship between exposure and end-exhaled air was unclear suggesting that breath measurements are of limited value in estimating very short term air exposures. Chamber experiments demonstrated the need for a breath of clean air, prior to end-exhaled air sampling, to eliminate residual styrene released from the lining of the respiratory airways. Inconclusive results were obtained when exhaled air measurements from the field and chamber studies were used to evaluate the physiological damping of the exposure variability at the receptor.

Petreas, Myrtoxeni Xenakis.

1990-01-01

204

Trichloroethylene (TCE) adsorption using sustainable organic mulch.  

PubMed

Soluble substrates (electron donors) have been commonly injected into chlorinated solvent contaminated plume to stimulate reductive dechlorination. Recently, different types of organic mulches with economic advantages and sustainable benefits have received much attention as new supporting materials that can provide long term sources of electron donors for chlorinated solvent bioremediation in engineered biowall systems. However, sorption capacities of organic mulches for chlorinated solvents have not been studied yet. In this study, the physiochemical properties of organic mulches (pine, hardwood and cypress mulches) were measured and their adsorption capacity as a potential media was elucidated. Single, binary and quaternary isotherm tests were conducted with trichloroethylene (TCE), tetrachloroethylene (PCE), trans-dichloroethylene (trans-DCE) and cis-dichloroethylene (cis-DCE). Among the three tested mulches, pine mulch showed the highest sorption capacity for the majority of the tested chemicals in single isotherm test. In binary or quaternary isotherm tests, competition among chemicals appears to diminish the differences in Q(e) for tested mulches. However, pine mulch also showed higher adsorption capacity for most chemicals when compared to hardwood and cypress mulches in the two isotherm tests. Based upon physicochemical properties of the three mulches, higher sorption capacity of pine mulch over hardwood and cypress mulches appears to be attributed to a higher organic carbon content and the lower polarity. PMID:20605328

Wei, Zongsu; Seo, Youngwoo

2010-09-15

205

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

SciTech Connect

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.

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

1997-12-01

206

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

USGS Publications Warehouse

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)

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

1989-01-01

207

Six interaction profiles for simple mixtures.  

PubMed

The Agency for Toxic Substances and Disease Registry (ATSDR) has a program for chemical mixtures that encompasses research on chemical mixtures toxicity, health risk assessment, and development of innovative computational methods. ATSDR prepared a guidance document that instructs users on how to conduct health risk assessment on chemical mixtures (Guidance Manual for the Assessment of Joint Toxic Action of Chemical Mixtures). ATSDR also developed six interaction profiles for chemical mixtures. Two profiles were developed for persistent environmental chemicals that are often found in contaminated fish and also can be detected in human breast milk. The mixture included chlorinated dibenzo-p-dioxins, hexachlorobenzene, dichlorodiphenyl dichloroethane, methyl mercury, and polychlorinated biphenyls. Two profiles each were developed for mixtures of metals and mixtures of volatile organic chemicals (VOCs) that are frequently found at hazardous waste sites. The two metal profiles dealt with (a) lead, manganese, zinc, and copper; and (b) arsenic, cadmium, chromium, and lead; the two VOCs mixtures dealt with (a) 1,1,1-trichloroethane, 1,1-dichloroethane, trichloroethylene, and tetrachloroethylene; and (b) benzene, ethylbenzene, toluene, and xylenes (BTEX). Weight-of-evidence methodology was used to assess the joint toxic action for most of the mixtures. Physiologically based pharmacokinetic modeling was used for BTEX. In most cases, a target-organ toxicity dose modification of the hazard index approach is recommended for conducting exposure-based assessments of noncancer health hazards. PMID:12892681

Pohl, Hana R; Roney, Nickolette; Wilbur, Sharon; Hansen, Hugh; De Rosa, Christopher T

2003-10-01

208

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

SciTech Connect

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.

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

209

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

SciTech Connect

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.

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

210

Determining multifumigants in whole grains and legumes, milled and low-fat grain products, spices, citrus fruit, and beverages.  

PubMed

Whole grain and legumes, milled and low-fat products, spices, citrus fruit, and dry beverage ingredients are leached with purified, acidified acetone-water solutions. Portions of these leachates are then back-extracted with purified isooctane. Liquid beverages are directly extracted with the isooctane. Six to 10 microL of each isooctane extract is then screened for 11 fumigant residues by gas chromatography (GC) using electron-capture and Hall electroconductivity detectors, and dual 20% OV-101 columns. Further confirmation of residue identity is done on 20% OV-225/20% OV-17 (2.5 + 1 mixed-bed) and 10% SP-1000 columns. The analytes determined include methyl bromide, methylene chloride, carbon disulfide, chloroform, ethylene dichloride, methyl chloroform, carbon tetrachloride, trichloroethylene, chloropicrin, ethylene dibromide, and tetrachloroethylene, using mixed-component reference solutions. Average recoveries from fortified grain range from 25 to 85%; methyl bromide and chloropicrin were recovered the least. Recoveries from the other kinds of food samples range from 43 to 111%. Advantages of this procedure are (1) clean sample extracts, (2) ppb detection limits, (3) residue stability, (4) relative speed, quality control, and safety of the analysis, and (5) results which gave an accurate picture of residual fumigants in grain and food products. PMID:3624185

Daft, J

1987-01-01

211

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

PubMed Central

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

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

212

Malignant Tumors of the Female Reproductive System  

PubMed Central

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

Labrèche, France

2012-01-01

213

Isolation of a methanogenic bacterium, Methanosarcina sp. strain FR, for its ability to degrade high concentration of perchloroethylene.  

PubMed

Tetrachloroethylene (PCE) is a toxic compound essentially used as a degreasing and dry-cleaning solvent. A methanogenic and sulfate-reducing consortium that dechlorinates and mineralizes high concentrations of PCE was derived from anaerobically digested sludge obtained from a waste water treatment plant (Bourg-en-Bresse, France). A methanogenic bacterium, strain FR, was isolated from this acclimated consortium. On the basis of morphological and physiological characteristics, strain FR was classified in the genus of Methanosarcina. Phylogeny analysis with the 16S rRNA gene sequence revealed that strain FR is highly related to Methanosarcina mazei and Methanosarcina frisia (99.6 and 99.5% identity, respectively). High concentrations (50-87 microM) of PCE were completely dechlorinated by strain FR cultures at the rate of 76 nM-mg protein(-1).day(-1). PCE dechlorination produced a nonidentified compound. The tracer experiments with [13C]PCE revealed that the product was nonchlorinated. Dechlorination of PCE to trichloroethylene was still active in the presence of boiled cell extract of the strain FR. However, no further dechlorination was observed. This result suggests that a cofactor rather than an enzymatic system is responsible for the first dechlorination of PCE. Dechlorination-active fractions purified from cell extracts on a XAD-4 column revealed the presence of F(420), F(430), and cobamides cofactors. This is the first report of the isolation of a methanogenic bacterium with the ability to dechlorinate high concentrations of PCE to a nonchlorinated product. PMID:10383226

Cabirol, N; Villemur, R; Perrier, J; Jacob, F; Fouillet, B; Chambon, P

1998-12-01

214

Plume and lithologic profiling with surface resistivity and seismic tomography.  

PubMed

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

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

2005-01-01

215

Interfacial tension of chlorinated aliphatic DNAPL mixtures as a function of organic phase composition.  

PubMed

This research evaluates the ability of three models to predict the organic liquid-water interfacial tension (IFT) of chlorinated aliphatic hydrocarbon mixtures that are dense nonaqueous-phase liquids (DNAPLs). Prediction of the IFT is relevantto quantify processes such as DNAPL trapping in soil pores and kinetic interphase mass transfer. Three models are evaluated: the Fu et al. method (FU) [Fu, J.; Buqiang, L.; Zihao, W. Chem. Eng. Sci. 1986,41 (10), 2673-2679]; a modified version of the Apostoluk and Szymanowski method (AS) [Apostoluk, W.; Szymanowski, J. Solvent Extr. Ion Exch. 1996, 14 (4), 635-651], and a simple linear ideal mixing theory (LIMT). The FU and AS methods require knowledge of NAPL-phase mole fractions and mutual solubilities. The LIMT method requires the pure organic liquid IFT and DNAPL-phase mole fraction as model input. Forty chlorinated DNAPL mixtures were used. The mixtures include two-, three-, and four-component DNAPL mixtures of tetrachloroethylene, trichloroethylene, 1,2-cis-dichloroethylene, 1,2-trans-dichloroethylene, and carbon tetrachloride. Measured IFTvaries nearlylinearlywith DNAPL-phase mole fraction for the all the DNAPL mixtures except those that include 1,2-DCE. The FU and LIMT models generally provided acceptable results for all mixtures. The FU model yielded an average relative error in the predicted IFT of 6.4%, while the LIMT model exhibited an average error of 9.3%. The AS method exhibited an average error of 16.4%. PMID:11944683

Seo, Hyeyoung Sophia; McCray, John E

2002-03-15

216

Affinity-based elimination of aromatic VOCs by highly crystalline multi-walled carbon nanotubes.  

PubMed

Carbon nanotubes (CNTs) are capable of adsorbing pollutant chemicals. Their adsorptive capacities and adsorbing mechanisms, however, are not fully understood. As-grown CNTs often contain both crystalline and amorphous carbon, and the ratio of carbon types can affect adsorption. In this study, highly crystalline multi-walled carbon nanotubes (HC-MWCNTs) were used as the adsorbent for volatile organic compounds (VOCs) in contaminated air samples. Air containing 23 added VOCs (1,1-dichloroethylene, dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, chloroform, 1,1,1-trichloroethane, carbon tetrachloride, 1,2-dichloroethane, benzene, trichloroethylene, 1,2-dichloropropane, bromodichloromethane, cis-1,3-dichloropropene, toluene, trans-1,3-dichloropropene, 1,1,2-trichloroethane, tetrachloroethylene, dibromochloromethane, m-xylene, p-xylene, o-xylene, bromoform, and p-dichlorobenzene) was used for model samples. Adsorptive experiments were carried out by passing the air samples through a cartridge packed with HC-MWCNTs. Initial results showing high selectivity and high affinity for adsorbing aromatic VOCs (benzene, toluene, m-xylene, p-xylene, o-xylene, and p-dichlorobenzene) have provided new insight into the adsorption mechanisms. Data suggest that the HC-MWCNTs, unlike conventional carbon materials, adsorb aromatic compounds according to Fukui's frontier theory, which is based on the interactions between the HOMO and LUMO of the aromatic VOCs and those of the HC-MWCNTs. PMID:18371779

Sone, Hiroaki; Fugetsu, Bunshi; Tsukada, Takayuki; Endo, Morinobu

2008-02-15

217

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

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).

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

2013-01-01

218

Is neurotoxicity associated with environmental trichloroethylene (TCE)?  

PubMed

Individuals who lived near 2 electronic manufacturing plants were exposed to odorous chlorinated solvents by inhalation (directly) and by out gassing from well water. An exposure zone was defined by concentrations of trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, and vinyl chloride in groundwater. The author adopted trichloroethylene as a "shorthand" for the exposure designation. Residents complained of impaired recall and concentration, and of dizziness; therefore, the focus of this investigation was brain functions. Neurobehavioral functions, Profile of Mood States, frequencies of 35 symptoms, and questionnaire responses provided by 236 residents from exposure zones were compared with responses provided by 161 unexposed regional referents and by 67 Phoenix residents who lived outside the exposure zone areas. Pulmonary functions were measured with spirometry. Residents of the exposure zones were compared with regional referents, and the former had significantly (p < .05) delayed simple and choice reaction times, impaired balance, delayed blink reflex latency R-1, and abnormal color discrimination. In addition, these individuals had impaired (1) cognitive functions, (2) attention and perceptual motor speed, and (3) recall. Individuals who lived in exposure zones had airway obstructions. Adverse mood state scores and frequencies of 33 of 35 symptoms were elevated. In conclusion, individuals who lived in the exposure zones had neurobehavioral impairments, reduced pulmonary functions, elevated Profile of Mood State scores, and excessive symptom frequencies. PMID:12194155

Kilburn, Kaye H

2002-01-01

219

Replacement Technologies for Precision Cleaning of Aerospace Hardware for Propellant Service  

NASA Technical Reports Server (NTRS)

The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-l13- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. Replacement technologies are being investigated for aerospace hardware and for gauges and instrumentation. This paper includes the findings of investigations of aqueous cleaning and verification of aerospace hardware using known contaminants, such as hydraulic fluid and commonly used oils. The results correlate nonvolatile residue with CFC 113. The studies also include enhancements to aqueous sampling for organic and particulate contamination. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon 225 (HCFC 225), HCFC 141b, HFE 7100(R), and Vertrel MCA(R) was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC 113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autogenous ignition and liquid oxygen mechanical impact testing.

Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

1997-01-01

220

Microwave-swing adsorption to capture and recover vapors from air streams with activated carbon fiber cloth.  

PubMed

Adsorption with regeneration is a desirable means to control the emissions of organic vapors such as hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) from air streams as it allows for capture, recovery, and reuse of those VOCs/HAPS. Integration of activated-carbon fiber-cloth (ACFC) adsorbent with microwave regeneration provides promise as a new adsorption/ regeneration technology. This research investigates the feasibility of using microwaves to regenerate ACFC as part of a process for capture and recovery of organic vapors from gas streams. A bench-scale fixed-bed microwave-swing adsorption (MSA) system was built and tested for adsorption of water vapor, methyl ethyl ketone (MEK), and tetrachloroethylene (PERC) from an airstream and then recovery of those vapors with microwave regeneration. The electromagnetic heating behavior of dry and vapor-saturated ACFC was also characterized. The MSA system successfully adsorbed organic vapors from the airstreams, allowed for rapid regeneration of the ACFC cartridge, and recovered the water and organic vapors as liquids. PMID:16190249

Hashisho, Zaher; Rood, Mark; Botich, Leon

2005-09-01

221

Air purification from TCE and PCE contamination in a hybrid bioreactors and biofilter integrated system.  

PubMed

A two-stage waste air treatment system, consisting of hybrid bioreactors (modified bioscrubbers) and a biofilter, was used to treat waste air containing chlorinated ethenes - trichloroethylene (TCE) and tetrachloroethylene (PCE). The bioreactor was operated with loadings in the range 0.46-5.50gm(-3)h(-1) for TCE and 2.16-9.02gm(-3)h(-1) for PCE. The biofilter loadings were in the range 0.1-0.97gm(-3)h(-1) for TCE and 0.2-2.12gm(-3)h(-1) for PCE. Under low pollutant loadings, the efficiency of TCE elimination was 23-25% in the bioreactor and 54-70% in the biofilter. The efficiency of PCE elimination was 44-60% in the bioreactor and 50-75% in the biofilter. The best results for the bioreactor were observed one week after the pollutant loading was increased. However, the process did not stabilize. In the next seven days contaminant removal efficiency, enzymatic activity and biomass content were all diminished. PMID:24316808

Tabernacka, Agnieszka; Zborowska, Ewa; Lebkowska, Maria; Borawski, Maciej

2014-01-15

222

In situ treatability testing of reductive dechlorination in wetland sediments  

USGS Publications Warehouse

In situ treatability testing was conducted in the discharge wetlands along West Branch Canal Creek at Aberdeen Proving Ground, MD. The potential for stimulating reductive dechlorination of 1,1,2,2-tetrachloroethane, tetrachloroethylene, trichloroethylene, and carbon tetrachloride in areas of preferential discharge or seeps was evaluated. Geological Survey that degrades chlorinated ethanes and ethylenes was tested using MICRO-Trac??? devices. At seep 3-4W, results of the C and BA MICRO-Trac??? treatments showed essentially no biodegradation of chlorinated solvents occurring under natural and bioaugmented conditions. Results of geochemical samples at this site indicated predominantly iron- and sulfate-reducing conditions consistent with the rapid discharge rates previously measured. The biostimulated treatment showed stimulation of methanogenic conditions and partial degradation of the parent chlorinated VOC to intermediate chlorinated compounds. The bioaugmented and bistimulated treatment showed the highest production of methane, the highest removal of parent compounds and intermediate daughter products, and the highest production of the non-chlorinated end product ethylene. This is an abstract of a paper presented at the proceedings of the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

Lorah, M.M.; Majcher, E.; Jones, E.; Driedger, G.; Dworatzek, S.; Graves, D.

2005-01-01

223

Elimination kinetics of volatile organics in humans using breath measurements  

SciTech Connect

During the past decade significant strides have been made toward understanding the sources and factors which lead to volatile organic chemical (VOC) exposure in the general population. Less is known, however, about the impact of low-level environmental exposure on human health. Investigations are underway in a number of laboratories in an effort to determine the uptake, distribution, metabolism, and elimination kinetics for VOCs in humans. We examined the elimination kinetics for the third phase for ten VOCs--1,1,-trichloroethane, trichloroethylene, tetrachloroethylene, benzene, toluene, m,p-xylenes, o-xylene, ethylbenzene, p-dichlorobenzene, and limonene--in human subjects. Subjects were exposed to a variety of common consumer products and breath samples were collected post-exposure while the subjects spent up to 10 hr in a clean air environment. VOCs from breath samples were collected into canisters or onto Tenax GC cartridges and analyzed by gas chromatography-mass spectrometry. Exponential modeling of the decay data was performed to obtain kinetic parameters. The half-lives for trichloroethylene and 1,1,1-trichloroethane were approximately 5 to 8 hr for the four subjects. In general, the magnitude and range of variability was larger for toluene, limonene, and p-dichlorobenzene than for the other VOCs; the elimination rate spanning a few hours to a day or two. Thus, VOCs exhibit relatively short residence times in the body relative to other halo-carbons, such as polychlorinated biphenyls and dioxins.

Pellizzari, E.D.; Wallace, L.A.; Gordon, S.M. (Research Triangle Institute, Research Triangle Park, NC (United States))

1992-07-01

224

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

USGS Publications Warehouse

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.

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

1991-01-01

225

Photochemical pollution at two southern California smog receptor sites  

SciTech Connect

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.

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

1992-06-01

226

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

USGS Publications Warehouse

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.

Zimmerman, Marc J.

2005-01-01

227

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

NASA Astrophysics Data System (ADS)

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.

Sutton, Patrick T.; Ginn, Timothy R.

2014-12-01

228

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

SciTech Connect

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.

Chase, J.

2000-03-13

229

Health assessment for E. I. Dupont Newport Plant Landfill, Newport, Delaware, Region 3. CERCLIS No. DED980555122. Preliminary report  

SciTech Connect

The E.I. Dupont Newport Plant Landfill, a seven acre site located adjacent to the Dupont Pigment Plant in Newport, Delaware, was used to bury paint pigments (heavy metals and chlorinated solvents) and radioactive materials from 1902 to 1975. The site was closed in 1975, the surface covered, graded and vegetated, and groundwater monitoring wells installed on- and off-site. Heavy metals (cadmium, barium, lead, zinc), and chlorinated solvents (trichloroethylene, tetrachloroethylene) have been measured in groundwater on-site. Radiation levels appear to be close to background. 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 groundwater. More information is needed concerning levels of contamination in private wells and the Christina River, the direction of groundwater flow, the size and extent of the groundwater contamination plume, the location of the private wells and the public water supply wells, and the composition of the population down gradient of the site.

Not Available

1988-05-11

230

Addition of Chlorinated Compounds in the Sonochemical Degradation of 2-Chlorophenol  

NASA Astrophysics Data System (ADS)

This paper outlines the research carried out on the sonochemical degradation of 2-chlorophenol in the presence and absence of chlorinated compounds. The degree of enhancement varied according to the characteristics of chlorinated compounds. The higher oxidation states of carbon in chlorinated compounds increase the degradation rate of 2-chlorophenol. When tetrachloroethylene (PCE) and chloroform (CF) have the same oxidation number, PCE is in a fully oxidized state. Therefore, the degradation rate of 2-chlorophenol in PCE is higher than that in CF. Free chlorine was formed from the sonochemical decomposition of chlorinated compounds. This free chlorine was then used for degrading the 2-chlorophenol or chlorinated compound itself. The amount of free chlorine is ordered by oxidation states of carbon in chlorinated compounds. The degradation rates of chlorinated compounds decreased with the co-presence of 2-chlorophenol, which is a result of ultrasonic energy being distributed to both compounds. An increase in time corresponds to a higher concentration of chloride ion. However, the application of the full amount of chlorinated compounds cannot complete dechlorination.

Lim, Myunghee; Son, Younggyu; Yang, Jaekeun; Khim, Jeehyeong

2008-05-01

231

Sanitary Landfill 1991 annual groundwater monitoring report  

SciTech Connect

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.

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

1992-02-01

232

Improved analysis of volatile halogenated hydrocarbons in water by purge-and-trap with gas chromatography and mass spectrometric detection.  

PubMed

An analytical system composed of a purge-and-trap injection system coupled to gas chromatography with mass spectrometric detection (PTI-GC-MS) specific for the analysis of volatile chlorinated hydrocarbons (VCHCs) (chloroform; 1,1,1-trichloroethane; tetrachloromethane; 1,1,2-trichloroethylene; tetrachloroethylene) and trihalomethanes (THMs) (chloroform; bromodichloromethane; dibromochloromethane; bromoform) in water was optimised. Samples were purged and trapped in a cold trap (-100 degrees C) fed with liquid nitrogen (cryo-concentration). In order to make this method suitable also for only slightly contaminated waters, some modifications were made to PTI sample introduction, in order to avoid any air intake into the system. PTI, GC and MS conditions were optimised for halogenated compound analysis and limits of detection (LOD) were evaluated. The proposed method allows analysis of samples whose concentrations range from microg/L to ng/L. It is, therefore, applicable to drinking waters, in analyses required by law, and to slightly contaminated aqueous matrices, such as those found in remote areas, in environmental monitoring. Moreover, by changing cold trap temperature, even sparkling mineral waters can be analysed, thus avoiding CO2 interference during the cryo-concentration phase. Our method has been successfully used on real samples: tap water, mineral water and Antarctic snow. PMID:16001554

Zoccolillo, Lelio; Amendola, Luca; Cafaro, Claudia; Insogna, Susanna

2005-06-10

233

Remedial evaluation of a UST site impacted with chlorinated hydrocarbons  

SciTech Connect

During assessment and remedial planning of an underground storage tank (UST) site, it was discovered that chlorinated hydrocarbons were present. A network of selected wells were sampled for analysis of halogenated volatile organics and volatile organic compounds to determine the extent of constituents not traditionally associated with refined petroleum motor fuel products. The constituents detected included vinyl chloride, tetrachloroethylene (PCE), bromodichloromethane, and 2-chloroethylvinyl ether. These analytical data were evaluated as to what effect the nonpetroleum hydrocarbon constituents may have on the remedial approach utilized the site hydrogeologic properties to its advantage and took into consideration the residential nature of the impacted area. The geometry of the dissolved plume is very flat and broad, emanating from the site and extending downgradient under a residential area situated in a transmissive sand unit. Ground-water pumping was proposed from two areas of the dissolved plume including five wells pumping at a combined rate of 55 gallons per minute (gpm) at a downgradient position, and two wells on-site to remove free product and highly impacted ground water. Also, to assist in remediation of the dissolved plume and to control vapors, a bioventing system was proposed throughout the plume area.

Ilgner, B.; Rainey, E. (Geraghty and Miller, Inc., Oak Ridge, TN (United States)); Ball, M.; Schutt, M.

1993-10-01

234

Sanitary Landfill 1991 annual groundwater monitoring report  

SciTech Connect

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.

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

1992-02-01

235

Volatile halocarbons as tracers of pulp mill effluent plumes  

SciTech Connect

This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloromethane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. In the fall, the colder effluent plume sinks into the hypolimnion and is confined by a bay/lake water-density gradient. In the specific case at hand, the distribution patterns of chloroform and a brominated analog, bromodichloromethane, also suggest the release of chloroform from sediments in the bay.

Comba, M.E.; Palabrica, V.S.; Kaiser, K.L.E. (National Water Research Inst., Burlington, Ontario (Canada). Lakes Research Branch)

1994-07-01

236

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

PubMed

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

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

2009-09-01

237

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

SciTech Connect

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

NONE

1997-02-01

238

Mixed Waste Management Facility groundwater monitoring report: Third quarter 1994  

SciTech Connect

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, herbicides/pesticides, indicator parameters, radionuclides, volatile organic compounds, and other constituents. As in previous quarters, tritium and trichloroethylene were the most widespread elevated constituents during third quarter 1994. Sixty-four (51%) of the 125 monitoring wells contained elevated tritium activities. Trichloroethylene concentrations exceeded the final PDWS in 22 (18%) wells. Chloroethene, 1,1-dichloroethylene, and tetrachloroethylene, elevated in one or more wells during third quarter 1994, also occurred in elevated levels during second quarter 1994. These constituents generally were elevated in the same wells during both quarters. Gross alpha, which was elevated in only one well during second quarter 1994, was elevated again during third quarter. Mercury, which was elevated during first quarter 1994, was elevated again in one well. Dichloromethane was elevated in two wells for the first time in several quarters.

Not Available

1994-12-01

239

Immobilization of proteins on glow discharge treated polymers  

NASA Astrophysics Data System (ADS)

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.

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

240

Risk communication: Health risks associated with environmentally contaminated private wells versus chloroform in a public water supply  

SciTech Connect

During March 1988, 16 private wells in Sault St. Marie, Michigan, were found to be contaminated with one or more environmental contaminants. Risk assessments for carcinogens (benzene, 1,2-dichloroethane, dichloromethane, trichloroethylene, and tetrachloroethylene) were formulated. The maximum concentration of chloroform in the city public water supply was 26 [mu]g/L. The relative health risk from the consumption of chlorinated surface water from the public water supply system would be approximately 4.3 times greater compared to that of consuming groundwater from the contaminated private wells. The affected residents were given three options: (a) continue consumption of bottled water; (b) connection to the existing public water supply system; or (c) construction of deep water wells. The citizens voted for the second option of connecting to the public water supply system and voluntarily accepted the relatively higher health risk. The State of Michigan later proposed to further improve the water purity by upgrading the public water supply system by the incorporation of a filtration plant. The project was completed in August 1993.

Sidhu, K.S.; Chadzynski, L. (Michigan Dept. of Public Health, Lansing, MI (United States))

1994-06-01

241

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

SciTech Connect

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.

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

1995-12-31

242

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

SciTech Connect

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.

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

1995-04-01

243

Desulfitobacterium metallireducens sp. nov., an anaerobic bacterium that couples growth to the reduction of metals and humic acids as well as chlorinated compounds.  

PubMed

Strain 853-15A(T) was enriched and isolated from uranium-contaminated aquifer sediment by its ability to grow under anaerobic conditions via the oxidation of lactate coupled to the reduction of anthraquinone-2,6-disulfonate (AQDS) to anthrahydroquinone-2,6-disulfonate (AHQDS). Lactate was oxidized incompletely to acetate and carbon dioxide according to the reaction CH3CHOHCOO(-)+ 2AQDS+H2O --> CH3COO(-)+ 2AHQDS+CO2. Additional electron donors utilized included formate, ethanol, butanol, butyrate, malate and pyruvate. Lactate also supported growth with Fe(III) citrate, Mn(IV) oxide, humic substances, elemental sulfur, 3-chloro-4-hydroxyphenylacetate, trichloroethylene or tetrachloroethylene serving as the electron acceptor. Growth was not observed with sulfate, sulfite, nitrate or fumarate as the terminal electron acceptor. The temperature optimum for growth was 30 degrees C, but growth was also observed at 20 and 37 degrees C. The pH optimum was approximately 7.0. The 16S rDNA sequence of strain 853-15A(T) suggested that it was most closely related to Desulfitobacterium dehalogenans and closely related to Desulfitobacterium chlororespirans and Desulfitobacterium frappieri. The phylogenetic and physiological properties exhibited by strain 853-15A(T) (= ATCC BAA-636(T)) place it within the genus Desulfitobacterium as the type strain of a novel species, Desulfitobacterium metallireducens sp. nov. PMID:12508850

Finneran, Kevin T; Forbush, Heather M; VanPraagh, Catherine V Gaw; Lovley, Derek R

2002-11-01

244

Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter  

USGS Publications Warehouse

Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure (P/P??), characteristic of the partitioning (dissolution) of the organic compounds in soil humic acid. Polar liquids exhibit markedly greater sorption capacities on soil humic acid than relatively nonpolar liquids, in keeping with the polar nature of the soil humic acid as a partition medium. The limiting sorption (partition) capacities of relatively non-polar liquids are remarkably similar when expressed in terms of volumes per unit weight of soil humic acid. The soil humic acid is found to be about half as effective as soil organic matter in sorption of relatively nonpolar organic compounds. The nearly constant limiting sorption capacity for nonpolar organic liquids with soil humic acid on a volume-to-weight basis and its efficiency in sorption relative to soil organic matter provide a basis for predicting the approximate sorption (partition) coefficients of similar compounds in uptake by soil in aqueous systems.

Chlou, G.T.; Kile, D.E.; Malcolm, R.L.

1988-01-01

245

Crucible melts and bench-scale ISV (in situ vitrification) tests on simulated wastes in INEL (Idaho National Engineering Laboratory) soils  

SciTech Connect

This report summarizes the results of eight crucible melt tests and three bench-scale in situ vitrification (ISV) test that were performed on simulated metals/soils mixtures containing actual site soils from the Idaho National Engineering Laboratory (INEL). The crucible melt and bench-scale ISV tests are a part of efforts by the Pacific Northwest Laboratory (PNL) to assist the INEL in conducting a treatability study on ISV for application to the mixed waste buried at the INEL subsurface disposal area (SDA). The crucible melt tests were performed to evaluate the effect of various chemical additives and metal oxidation techniques on soil melting temperatures, melt viscosities, metals versus electrode oxidation potentials, and metals incorporation in the glass. The bench-scale ISV tests were performed to supplement the existing ISV data base with information on certain hazardous materials that have not been adequately evaluated in previous ISV tests. These materials included five EP toxicity metals, various volatile organic materials fixed in a cementitious matrix (including carbon tetrachloride (CCl{sub 4}), trichloroethylene (TCE), and tetrachloroethylene (PCE)), and asbestos. In addition, the bench-scale test were used to evaluated the effect of the proposed chemical additive on ISV processing performance and product quality. 8 refs., 24 figs., 19 tabs.

Farnsworth, R.K.; Oma, K.H.; Reimus, M.A.H.

1990-05-01

246

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

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.

Thiros, Susan A.

2000-01-01

247

Characterization of anaerobic chloroethene-dehalogenating activity in several subsurface sediments  

SciTech Connect

Anaerobic microcosms of subsurface soils from four locations were used to investigate the separate effects of several electron donors on tetrachloroethylene (PCE) dechlorination activity. The substrates tested were methanol, formate, lactate, acetate, and sucrose. Various levels of sulfate-reducing, acetogenic, fermentative, and methanogenic activity were observed in all sediments. PCE dechlorination was detected in all microcosms, but the amount of dehalogenation varied by several orders of magnitude. Trichloroethylene was the primary dehalogenation product; however, small amounts of cis-1,2-dichloroethylene, 1,1-dichloroethylene, and vinyl chloride were also detected in several microcosms. Lactate-amended microcosms showed large amounts of dehalogenation. in three of the four sediments. One of the two sediments which showed positive activity with lactate also had large amounts of delialogenation with methanol. Sucrose, formate, and acetate also stimulated large amounts of delialogenation in one sediment that showed activity with lactate. These results suggest that lactate may be an appropriate substrate for screening sediments for PCE or TCE delialogenation activity, but that the microbial response is not sufficient for complete in situ bioremediation. A detailed study of the Victoria activity revealed that delialogenation rates were more similar to the Cornell culture than to rates measured for methanogens, or a methanol-enriched sediment culture. This may suggest that these sediments contain a highly efficient delialogenation activity similar to the Cornell culture. This assertion is supported further by the fact that an average of 3% of added reducing equivalents could be diverted to dehalogenation in tests which were conducted using PCE-saturated hexadecane as a constant source of PCE during incubation. Further evidence is needed to confirm this premise. The application of these results to in situ bioremediation of highly contaminated areas are discussed.

Skeen, R.S.; Gao, J.; Hooker, B.S.; Quesenberry, R.D.

1996-11-01

248

Alternative Methods for Assessing Contaminant Transport from the Vadose Zone to Indoor Air  

NASA Astrophysics Data System (ADS)

Vapor intrusion, which is the transport of contaminant vapors from groundwater and the vadose zone to indoor air, has emerged as a significant human health risk near hazardous waste sites. Volatile organic compounds (VOCs) such as trichloroethylene (TCE) and tetrachloroethylene (PCE) can volatilize from groundwater and from residual sources in the vadose zone and enter homes and commercial buildings through cracks in the slab, plumbing conduits, or other preferential pathways. Assessment of the vapor intrusion pathway typically requires collection of groundwater, soil gas, and indoor air samples, a process which can be expensive and time-consuming. We evaluated three alternative vapor intrusion assessment methods, including 1) use of radon as a surrogate for vapor intrusion, 2) use of pressure differential measurements between indoor/outdoor and indoor/subslab to assess the potential for vapor intrusion, and 3) use of passive, longer-duration sorbent methods to measure indoor air VOC concentrations. The primary test site, located approximately 30 miles south of San Francisco, was selected due to the presence of TCE (10 - 300 ug/L) in shallow groundwater (5 to 10 feet bgs). At this test site, we found that radon was not a suitable surrogate to asses vapor intrusion and that pressure differential measurements are challenging to implement and equipment-intensive. More significantly, we found that the passive, longer-duration sorbent methods are easy to deploy and compared well quantitatively with standard indoor air sampling methods. The sorbent technique is less than half the cost of typical indoor air methods, and also provides a longer duration sample, typically 3 to 14 days rather than 8 to 24 hours for standard methods. The passive sorbent methods can be a reliable, cost-effective, and easy way to sample for TCE, PCE and other VOCs as part of a vapor intrusion investigation.

Baylor, K. J.; Lee, A.; Reddy, P.; Plate, M.

2010-12-01

249

Partitioning of non-ionic surfactants between water and non-aqueous phase liquids (NAPLs) of chlorinated organics  

NASA Astrophysics Data System (ADS)

Due to the hydrophobic nature, chlorinated organic compounds penetrate soil and groundwater to form non-aqueous phase liquids (NAPLs). At the sites contaminated with such NAPLs, thus, surfactants are applied to increase the aqueous solubility of chlorinated organics via micellar solubilization. However, a portion of surfactants can be partitioned into NAPL phases by forming reverse micelles within them. Consequently, lesser amounts of surfactants are available for the micellar solubilization of chlorinated organics in the aqueous phase. In this study, we investigated the partitioning behavior of non-ionic surfactants (Tween 20, Tween 40, Tween 80, and Triton X-100) between water and a NAPL phase consisting of tetrachloroethylene (PCE), trichloroethylene (TCE), or chloroform (CF). According to the experimental results, the partitioning of surfactants in the water-NAPL systems was found to follow linear or Langmuir-type isotherms. Regardless of type of surfactants, the partitioning loss of surfactants into NAPLs became greater with the more hydrophilic (i.e., the lower water-NAPL interfacial tension) chlorinated organics: PCE < TCE < CF. Notably, the partitioning of all Tween surfactants into the NAPLs consisting of the least hydrophilic PCE was minimal. The partitioning behavior among different surfactants was somewhat complicated. The partitioning extent into CF-NAPLs increased in the order of Tween 20 < Tween 40 < Tween 80 << Triton X-100, suggesting that the greater partitioning occurred with the more hydrophobic (i.e., the lower hydrophilic-lipophilic balance, HLB) surfactant. Consistent with this postulation, the surfactant partitioning into PCE-NAPLs showed the similar trend. In case of TCE-NAPLs, however, the more hydrophobic Tween 40 was partitioned to a less extent than Tween 20. Therefore, the specific interaction of a NAPL-surfactant pair as well as their individual properties should be considered when selecting an effective surfactant for the remediation of a NAPL-contaminated site.

KANG, S.; Jeong, H. Y.

2013-12-01

250

Field-scale prediction of enhanced DNAPL dissolution based on partitioning tracers  

NASA Astrophysics Data System (ADS)

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a tetrachloroethylene (PCE)-contaminated dry cleaner site, located in Jacksonville, Florida. The EST model is an analytical solution with field-measurable input parameters. Measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ ethanol flood. In addition, a simulated partitioning tracer test from a calibrated, three-dimensional, spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The EST ethanol prediction based on both the field partitioning tracer test and the simulation closely matched the total recovery well field ethanol data with Nash-Sutcliffe efficiency E = 0.96 and 0.90, respectively. The EST PCE predictions showed a peak shift to earlier arrival times for models based on either field-measured or simulated partitioning tracer tests, resulting in poorer matches to the field PCE data in both cases. The peak shifts were concluded to be caused by well screen interval differences between the field tracer test and ethanol flood. Both the EST model and UTCHEM were also used to predict PCE aqueous dissolution under natural gradient conditions, which has a much less complex flow pattern than the forced-gradient double five spot used for the ethanol flood. The natural gradient EST predictions based on parameters determined from tracer tests conducted with a complex flow pattern underestimated the UTCHEM-simulated natural gradient total mass removal by 12% after 170 pore volumes of water flushing indicating that some mass was not detected by the tracers likely due to stagnation zones in the flow field. These findings highlight the important influence of well configuration and the associated flow patterns on dissolution.

Wang, Fang; Annable, Michael D.; Jawitz, James W.

2013-09-01

251

[Organohalogen contamination of a dialysis-water treatment plant].  

PubMed

On March 2001 the regular quality control test of the water used for dialysis in an urban centre using a reverse osmosis system revealed a high level of organo-halogenated contamination. The compounds implicated were: trichloroethylene (trielene) [M.Wt. 131 D], tetrachloroethylene, trichloromethane (chloroform) [M.Wt. 121 D], chlorodibromomethane. The dialysis unit was closed. Water samples were analysed in duplicate. The table shows the values (in ppm or microgram/l) obtained for chloroform at the given times: March 8th, altered sample; March 12th, confirmation sample; March 16th, after osmosis membranes change; March 22nd, after carbon filtration replacement; March 26th, after softener resins substitution. The AAMI doesn't recommend any value for organo-halogenated compounds in dialysis water. In the past, the European Pharmacopoeia and the Italian Health Ministry released some reference values for tap water, values which were extended to water used for dialysis. The values are 1 ppm as reference value, 30 ppm as maximum accepted value for the sum of all organo-halogenated compounds, and 10 ppm as the recommended value. In conclusion, the problem was solved by progressive replacement of the components of the water treatment system, even though the real cause remained undetermined. No clinical symptom was recorded and no level of chloroform or trielene was detected in patients' sera despite the low molecular weight and low protein binding of the compounds. A strict control of the water quality and a more comprehensive and updated reference guide are needed for better and safer dialysis delivery. PMID:12369053

Formica, M; Vallero, A; Forneris, G; Cesano, G; Pozzato, M; Borca, M; Iadarola, G M; Quarello, F

2002-01-01

252

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

PubMed

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

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

2013-10-01

253

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

PubMed

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

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

2015-04-01

254

Design of micellar-enhanced ultrafilters  

SciTech Connect

A systematic calculational procedure is developed for the design of micellar-enhanced ultrafilters to treat aqueous streams contaminated with organic pollutants. Flat plate, spiral wound, hollow fiber, and tubular modules are evaluated for performance and cost. Membranes having a 5,000 molecular weight cutoff (MWCO), which reject all micelles, and 50,000 MWCO membranes, which do not, are used as examples. The surfactant considered is hexadecyl(=cetyl)pyridinium chloride (CPC), and the organic pollutants are chlorobenzene, trichloroethylene, tetrachloroethylene, and toluene. A combined osmotic-pressure and fouling-resistance model quantifies the ultrafiltration permeate flux. Also important are the molar solubilization ratios of the respective organics in aqueous CPC solutions, the osmotic pressure of the surfactant as a function of concentration, and the intrinsic rejection behavior of the membranes for surfactant monomers and micelles. For treatment of 2,000 gal/day of wastewater saturated with chlorobenzene, the optimal design consists of a 3 equilibrium stage system using 18 tubular 50,000 MWCO modules in the first stage operating at 207 kPa, 2 spiral wound 50,000 MWCO modules in the second stage operating at 207 kPa, and 2 spiral wound 5,000 MWCO modules operating at 1,034 kPa in the final stage. The optimum volume concentration ratio is 6; the surfactant concentrate leaves the ultrafilter at 17 kg/m{sup 3}, and the crossflow velocity is 2 m/s in each stage. This design eliminates the need for prefiltration of the total feed and minimizes capital and operating costs.

Markels, J.H.; Lynn, S.; Radke, C.J. [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

1995-07-01

255

Ultrafine metal oxides dismantle chlorinated organics  

SciTech Connect

Researchers at Kansas State University (Manhattan) have developed a low-temperature, noncatalytic process that destroys chlorinated organic compounds without creating harmful byproducts. The process, dubbed destructive adsorption, uses ultrafine particles of several common metal oxides to convert chlorocarbon molecules into metal chlorides and carbon oxides. To date, the process has only been demonstrated for the bench-scale decomposition of carbon tetrachloride (CCl{sub 4}). However, Colorado-based NanTech has recently been awarded a grant to develop the process for commercialization. Certain metal oxides, such as CaO and MgO, react favorably with many of the chlorinated organics commonly found in industrial exhaust streams, and in the organics-laden vapors commonly recovered during soil and groundwater remediation. In the presence of chlorinated compounds such as carbon tetrachloride (CCl{sub 4}), chloroform (CHCl{sub 3}), tetrachloroethylene (C{sub 2}Cl{sub 4}) and chlorobenzene (C{sub 6}H{sub 5}Cl), these metal oxides adsorb chlorine atoms to form metal chlorides (MgCl{sub 2} or CaCl{sub 2}), and their oxygen atoms combine with carbon in the organics to form CO and CO{sub 2}. While these reactions are favorable from a thermodynamic standpoint (all are mildly exothermic), reaction rates are kinetically limited, because they involve solid-gas or solid-liquid reactions. As the metal chloride forms on the surface of the metal oxide, the resulting salt buildup gradually impedes--and eventually prevents--the reaction between the metal oxide and the chlorocarbon compound. To overcome this obstacle, the Kansas State researchers experimented with extremely small particles of metal oxides--less than 25 nanometers dia.--to maximize overall surface area. This increased the reactivity and the capacity of the metal oxide particles.

NONE

1995-07-01

256

Influence of viscous, gravitational, and capillary forces on DNAPL saturation  

SciTech Connect

Four dense nonaqueous phase liquids (DNAPLs) -- bromoform, chlorobenzene, tetrachloroethylene, and trichloroethylene -- were used to investigate the influence of viscous, gravitational, and capillary forces on DNAPL saturation in a natural aquifer sand. The relative magnitudes of these forces are expressed in terms of two dimensionless groups, the Capillary Number (N{sub Ca}), defined as the ratio of the viscous force to capillary force, and the Bond Number (N{sub Bo}), defined as the ratio of the gravitational force to capillary force. Nondimensionalization of the equations governing two-phase flow suggests that DNAPL saturation should be a function of a linear combination of the Capillary and Bond Numbers (N{sub Ca}/k{sub rw} {minus} N{sub Bo}), provided the permeability to water (k{sub rw}) in the presence of discontinuous DNAPL is considered. Experimental studies in which DNAPL saturations were measured over a range of Capillary and Bond Numbers for upward, horizontal, and downward displacement of DNAPL by water corroborate the results of the nondimensionalization. DNAPL saturations generally decreased with increasing Capillary Number and with decreasing Bond Number until N{sub Ca}/k{sub rw} {minus} N{sub Bo} was greater than approximately 1 {times} 10{sup {minus}5}, at which point residual saturation was attained. For the DNAPLs used in this study, with adhesion tensions on the order of 26 dynes/cm and Bond Numbers ranging from 1.3 {times} 10{sup {minus}7} to 2.4 {times} 10{sup {minus}6}, residual saturation was attained at Capillary Numbers greater than approximately 5 {times} 10{sup {minus}5}. These results provide a means of estimating the system conditions under which the DNAPLs studied achieve residual saturation in aquifer material.

Dawson, H.E. [Colorado School of Mines, Golden, CO (United States). Div. of Environmental Science and Engineering; Roberts, P.V. [Stanford Univ., CA (United States). Dept. of Civil Engineering

1997-03-01

257

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

PubMed

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

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

2014-10-18

258

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

PubMed

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

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

2013-08-01

259

Determinants of personal, indoor and outdoor VOC concentrations: An analysis of the RIOPA data  

PubMed Central

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

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

2014-01-01

260

Mechanisms, chemistry and kinetics of the anaerobic biodegradation of cis-dichloroethylene and vinyl chloride. First annual progress report, September 15, 1996--September 14, 1997  

SciTech Connect

'This three-year project is to study the anaerobic biological conversion of cis-1,2- dichloroethene (cDCE) and vinyl Chloride (VC) to ethene. The study is being conducted in three separate phases, the first to better understand the mechanisms involved in cDCE and VC biodegradation, the second to evaluate the chemistry of the processes involved, and the third, to study factors affecting reaction kinetics. Major funding is being provided by the US Department of Energy, but the DuPont Chemical Company has also agreed to directly cost-share on the project at a rate of $75,000 per year for the three year period. Tetrachloroethylene (PCE) and trichloroethylene (TCE) are solvents that are among the most widely occurring organic groundwater contaminants. The biological anaerobic reduction-of chlorinated aliphatic hydrocarbons (CAHs) such as PCE and TCE to cDCE and VC in groundwater was reported in the early 1980s. Further reduction of PCE and its intermediates to ethene was reported in 1989. Several pure cultures of anaerobic bacteria have been found to reductively dehalogenate PCE to cDCE Rates of reduction of PCE and TCE to cDCE are high and the need for electron donor addition for the reactions is small. However, the subsequent reduction of cDCE to VC, and then of VC to the harmless end product, ethene, is much slower and only recently has a pure culture been reported that is capable of reducing cDCE to VC or VC to ethene. There are numerous. reports of such conversions in mixed cultures. The reduction of cDCE and VC to ethene is where basic research is most needed and is the subject of this study.'

McCarty, P.L.; Spormann, A.

1997-01-01

261

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

USGS Publications Warehouse

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.

Harte, Philip T.; Flanagan, Sarah M.

2011-01-01

262

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

USGS Publications Warehouse

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.

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

2011-01-01

263

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

PubMed

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

Makris, Konstantinos C; Andra, Syam S

2014-01-15

264

Microwave-assisted generation of standard gas mixtures.  

PubMed

Microwave heating was employed for preparation of the standard gas of volatile organic compounds (VOCs) and semivolatile organic compounds (semi-VOCs) by using a 1000 W commercial domestic microwave oven and 1 L gas-sampling bulbs. The VOCs investigated were benzene, chloroform, 1,3-dichlorobenzene, tetrachloroethylene, toluene, and 1,1,2-trichloroethane, and the semi-VOCs used were the polychlorinated biphenyls (PCBs) PCB 1016 and PCB 1248. Since these weakly or nonpolar molecules are very poor absorbers of microwave energy, an appropriate amount of water was introduced to accept microwave radiation and act as the thermal source to accelerate their evaporation. The glass bulb may also contribute thermal energy to the VOCs/semi-VOCs by accepting microwave energy to a small degree. For 0.5 microL of liquid VOCs on 10 mg of glass wool, it was shown that 15 microL of H2O and 60 s of microwave heating yielded a very efficient evaporation [97.2-106.4%, compared with a classic method (Muller, L; Gorecki, T.; Pawliszyn, J. Fresenius' J. Anal. Chem. 1999, 364, 610-616)]. For 1 microL of PCB solution (1000 microg/mL in hexane), 15 microL of H2O and 90 s of microwave heating also provided a complete evaporation. The addition of water was particularly significant for microwave-assisted evaporation of PCBs because semi-VOCs are much more difficult to evaporate than VOCs. This developed microwave technique proved to be quite simple, powerful, rapid, accurate, and safe for the preparation of VOC/semi-VOC standard gas. Solid- phase microextraction combined with gas chromatography was used for the gas analysis. PMID:12038774

Xiong, Guohua; Pawliszyn, Janusz

2002-05-15

265

An association between mutagenicity of the Ara test of Salmonella typhimurium and carcinogenicity in rodents for 16 halogenated aliphatic hydrocarbons.  

PubMed

Sixteen halogenated aliphatic hydrocarbons were assayed for genotoxicity using the Ara mutagenicity assay with Salmonella typhimurium. Seven substances (1,2-dibromo-3-chloropropane, 1,2-dibromoethane, 1,2-dichloroethane, vinyl bromide, hexachloro-1,3-butadiene, iodoform and vinilydene chloride) were mutagenic at non-lethal doses. Comparatively, nine compounds (chloroform, carbon tetrachloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, tetrachloroethylene, trichloroethylene, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane and hexachloroethane) were non-mutagenic after being assayed both in the presence and absence of metabolic activation with a rat liver microsomal fraction (S9). All negative compounds (except hexachloroethane) gave a lethal response, which could be an indication that bacteria were adequately exposed. The concordance between mutagenicity in the Ara test and carcinogenicity in rodents for this group of halogenated hydrocarbons was (31%) significantly lower than the concordance (72%) previously found in the Ara test with respect to a wider range of chemical classes. This result is in agreement with data reported for other genotoxicity assays. The presence of non-genotoxic carcinogens versus genotoxic non-carcinogens is discussed as a possible explanation. Five positive compounds (1,2-dibromo-3-chloropropane, 1,2-dibromoethane, 1,2-dichloroethane, vinyl bromide and hexachloro-1,3-butadiene) were analyzed for a quantitative relationship between carcinogenic potency in rats and the potency of response in the Ara mutagenicity test. This was possible because the Ara test, for volatile compounds (such as vinyl bromide), did not require the use of special vaporization techniques, which are difficult to evaluate quantitatively for mutagenic activity. A highly significant correlation was found between the mutagenic efficiencies of the five compounds in the Ara test and their carcinogenic potencies in rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1881351

Roldán-Arjona, T; García-Pedrajas, M D; Luque-Romero, F L; Hera, C; Pueyo, C

1991-05-01

266

Survey of bottled drinking water sold in Canada. Part 2. Selected volatile organic compounds  

SciTech Connect

Selected volatile organic compound (VOC) contaminants were determined in 182 samples of retail bottled waters purchased in Canada. Samples included spring water (86) packaged in containers of polyethylene or in smaller containers of transparent plastic or glass, mineral water (61) packaged only in transparent plastic or glass, and miscellaneous bottled waters (35). Analyses were performed by 3 laboratories, each using headspace sampling and capillary gas chromatography with either mass spectrometric (1 laboratory) or flame ionization detection with mass spectrometric confirmation, if required (2 laboratories). Benzene, the contaminant of primary interest, was detected in only 1 of the 182 samples at 2 {mu}g/kg. Other VOC contaminants detected (number of positive samples, average, and range of positives in {mu}g/kg) included toluene (20, 6.92, 0.5-63), cyclohexane (23, 39.2, 3-108), chloroform (12, 25.8, 3.7-70), and dichloromethane (4, 59, 22-97). Cyclohexane was found in the plastic and as a migrant from the plastic in 20 samples of spring water, but it was found in only 1 of 61 mineral water samples analyzed at only 3 {mu}g/kg/. Chloroform was found almost exclusively in samples that could have been obtained from public water supplies. It was not found in mineral water samples, but it was found in 1 spring water sample at 3.7 {mu}g/kg. The source of the toluene contamination was not known. Other VOCs detected include ethanol and limonene, associated with added flavoring; pentane, as a migrant from a foamed polystyrene cap liner; and 1,1,2,2-tetra-chloroethylene in a sample of demineralized water. 10 refs., 6 tabs.

Page, B.D.; Conacher, H.B.S.; Salminen, J. [Health and Welfare Canada, Ottawa, Ontario (Canada)] [and others

1993-01-01

267

Effects of Daily Precipitation and Evapotranspiration Patterns on Flow and VOC Transport to Groundwater along a Watershed Flow Path  

USGS Publications Warehouse

MTBE and other volatile organic compounds (VOCs) are widely observed in shallow groundwater in the United States, especially in urban areas. Previous studies suggest that the atmosphere and/or nonpoint surficial sources could be responsible for some of those VOCs, especially in areas where there is net recharge to groundwater. However, in semiarid locations where annual potential evapotranspiration can exceed annual precipitation, VOC detections in groundwater can be frequent. VOC transport to groundwater under net discharge conditions has not previously been examined. A numerical model is used here to demonstrate that daily precipitation and evapotranspiration (ET) patterns can have a significant effect on recharge to groundwater, water table elevations, and VOC transport. Ten-year precipitation/ET scenarios from six sites in the United States are examined using both actual daily observed values and "average" pulsed precipitation. MTBE and tetrachloroethylene transport, including gas-phase diffusion, are considered. The effects of the precipitation/ET scenarios on net recharge and groundwater flow are significant and complicated, especially under low-precipitation conditions when pulsed precipitation can significantly underestimate transport to groundwater. In addition to precipitation and evapotranspiration effects, location of VOC entry into the subsurface within the watershed is important for transport in groundwater. This is caused by groundwater hydraulics at the watershed scale as well as variations in ET within the watershed. The model results indicate that it is important to consider both daily precipitation/ET patterns and location within the watershed in order to interpret VOC occurrence in groundwater, especially in low-precipitation settings.

Johnson, R.L.; Thoms, R.B.; Zogorski, J.S.

2003-01-01

268

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

PubMed Central

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

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

2007-01-01

269

Occupation and cancer in Britain  

PubMed Central

Background: Prioritising control measures for occupationally related cancers should be evidence based. We estimated the current burden of cancer in Britain attributable to past occupational exposures for International Agency for Research on Cancer (IARC) group 1 (established) and 2A (probable) carcinogens. Methods: We calculated attributable fractions and numbers for cancer mortality and incidence using risk estimates from the literature and national data sources to estimate proportions exposed. Results: 5.3% (8019) cancer deaths were attributable to occupation in 2005 (men, 8.2% (6362); women, 2.3% (1657)). Attributable incidence estimates are 13?679 (4.0%) cancer registrations (men, 10?063 (5.7%); women, 3616 (2.2%)). Occupational attributable fractions are over 2% for mesothelioma, sinonasal, lung, nasopharynx, breast, non-melanoma skin cancer, bladder, oesophagus, soft tissue sarcoma, larynx and stomach cancers. Asbestos, shift work, mineral oils, solar radiation, silica, diesel engine exhaust, coal tars and pitches, occupation as a painter or welder, dioxins, environmental tobacco smoke, radon, tetrachloroethylene, arsenic and strong inorganic mists each contribute 100 or more registrations. Industries and occupations with high cancer registrations include construction, metal working, personal and household services, mining, land transport, printing/publishing, retail/hotels/restaurants, public administration/defence, farming and several manufacturing sectors. 56% of cancer registrations in men are attributable to work in the construction industry (mainly mesotheliomas, lung, stomach, bladder and non-melanoma skin cancers) and 54% of cancer registrations in women are attributable to shift work (breast cancer). Conclusion: This project is the first to quantify in detail the burden of cancer and mortality due to occupation specifically for Britain. It highlights the impact of occupational exposures, together with the occupational circumstances and industrial areas where exposures to carcinogenic agents occurred in the past, on population cancer morbidity and mortality; this can be compared with the impact of other causes of cancer. Risk reduction strategies should focus on those workplaces where such exposures are still occurring. PMID:20424618

Rushton, L; Bagga, S; Bevan, R; Brown, T P; Cherrie, J W; Holmes, P; Fortunato, L; Slack, R; Van Tongeren, M; Young, C; Hutchings, S J

2010-01-01

270

Occupational cancer burden in Great Britain  

PubMed Central

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

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

271

Occupational cancer burden in Great Britain.  

PubMed

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

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

2012-06-19

272

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

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.

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

273

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

SciTech Connect

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.

Jerome, K.M.

1999-06-08

274

Valiant 'Zero-Valent' Effort Restores Contaminated Grounds  

NASA Technical Reports Server (NTRS)

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.

2005-01-01

275

VOCs in Non-Arid Soils Integrated Demonstration: Technology summary  

SciTech Connect

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.

Not Available

1994-02-01

276

A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States - II) Untreated drinking water sources  

USGS Publications Warehouse

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), ??-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.

Focazio, M.J.; Kolpin, D.W.; Barnes, K.K.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Barber, L.B.; Thurman, M.E.

2008-01-01

277

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

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).

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

278

Analysis of dechlorination kinetics of chlorinated aliphatic hydrocarbons by Fe(II) in cement slurries.  

PubMed

Degradative solidification/stabilization with ferrous iron (DS/S-Fe(II)) has been found to be effective in degrading a number of chlorinated aliphatic hydrocarbons including 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA), tetrachloroethylene (PCE), trichloroethylene (TCE), 1,1-dichloroethylene (1,1-DCE), vinyl chloride (VC), carbon tetrachloride (CT) and chloroform (CF). Previous studies have characterized degradation kinetics in DS/S-Fe(II) systems as affected by Fe(II) dose, pH and initial target organic concentration. The goal of this study is to investigate the importance of various chemical properties on degradation kinetics of DS/S-Fe(II). This was accomplished by first measuring rate constants for degradation of 1,1,1-TCA, 1,1,2,2-TeCA and 1,2-dichloroethane (1,2-DCA) in individual batch experiments. Rate constants developed in these experiments and those obtained from the literature were related to thermodynamic parameters including one-electron reduction potential, two-electron reduction potential, bond dissociation energy and lowest unoccupied molecular orbital energies. Degradation kinetics by Fe(II) in cement slurries were generally represented by a pseudo-first-order rate law. The results showed that the rate constants for chlorinated methanes (e.g. CT, CF) and chlorinated ethanes (e.g. 1,1,1-TCA) were higher than those for chlorinated ethylenes (e.g. PCE, TCE, 1,1-DCE and VC) under similar experimental conditions. The log of the pseudo-first-order rate constant (k) was found to correlate better with lowest unoccupied molecular orbital energies (E(LUMO)) (R2=0.874) than with other thermodynamic parameter descriptors. PMID:17707584

Jung, Bahngmi; Batchelor, Bill

2008-03-21

279

An Assessment of the Interindividual Variability of Internal Dosimetry during Multi-Route Exposure to Drinking Water Contaminants  

PubMed Central

The objective of this study was to evaluate inter-individual variability in absorbed and internal doses after multi-route exposure to drinking water contaminants (DWC) in addition to the corresponding variability in equivalent volumes of ingested water, expressed as liter-equivalents (LEQ). A multi-route PBPK model described previously was used for computing the internal dose metrics in adults, neonates, children, the elderly and pregnant women following a multi-route exposure scenario to chloroform and to tri- and tetra-chloroethylene (TCE and PERC). This scenario included water ingestion as well as inhalation and dermal contact during a 30-min bathroom exposure. Monte Carlo simulations were performed and distributions of internal dose metrics were obtained. The ratio of each of the dose metrics for inhalation, dermal and multi-route exposures to the corresponding dose metrics for the ingestion of drinking water alone allowed computation of LEQ values. Mean BW-adjusted LEQ values based on absorbed doses were greater in neonates regardless of the contaminant considered (0.129–0.134 L/kg BW), but higher absolute LEQ values were obtained in average adults (3.6–4.1 L), elderly (3.7–4.2 L) and PW (4.1–5.6 L). LEQ values based on the parent compound’s AUC were much greater than based on the absorbed dose, while the opposite was true based on metabolite-based dose metrics for chloroform and TCE, but not PERC. The consideration of the 95th percentile values of BW-adjusted LEQ did not significantly change the results suggesting a generally low intra-subpopulation variability during multi-route exposure. Overall, this study pointed out the dependency of the LEQ on the dose metrics, with consideration of both the subpopulation and DWC. PMID:21139873

Valcke, Mathieu; Krishnan, Kannan

2010-01-01

280

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

SciTech Connect

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.

L.A. Johnson, Jr.

2003-06-30

281

Field-scale prediction of enhanced DNAPL dissolution based on partitioning tracers.  

PubMed

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a tetrachloroethylene (PCE)-contaminated dry cleaner site, located in Jacksonville, Florida. The EST model is an analytical solution with field-measurable input parameters. Measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ ethanol flood. In addition, a simulated partitioning tracer test from a calibrated, three-dimensional, spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The EST ethanol prediction based on both the field partitioning tracer test and the simulation closely matched the total recovery well field ethanol data with Nash-Sutcliffe efficiency E=0.96 and 0.90, respectively. The EST PCE predictions showed a peak shift to earlier arrival times for models based on either field-measured or simulated partitioning tracer tests, resulting in poorer matches to the field PCE data in both cases. The peak shifts were concluded to be caused by well screen interval differences between the field tracer test and ethanol flood. Both the EST model and UTCHEM were also used to predict PCE aqueous dissolution under natural gradient conditions, which has a much less complex flow pattern than the forced-gradient double five spot used for the ethanol flood. The natural gradient EST predictions based on parameters determined from tracer tests conducted with a complex flow pattern underestimated the UTCHEM-simulated natural gradient total mass removal by 12% after 170 pore volumes of water flushing indicating that some mass was not detected by the tracers likely due to stagnation zones in the flow field. These findings highlight the important influence of well configuration and the associated flow patterns on dissolution. PMID:23911784

Wang, Fang; Annable, Michael D; Jawitz, James W

2013-09-01

282

Air pollution: assessing total exposure in the United States  

SciTech Connect

In recent years air pollution science has been undergoing two revolutions as the result of shifts of perception in the volumetric scale on which important adverse impacts occur. One revolution has come about because of the realization that some pollutants produce impacts at an extremely large scale. The second revolution is the result of the growing realization that the health impacts of many pollutants can only be understood through careful consideration of such microenvironments as those inside homes, vehicles, and work places. In both cases, the traditional focus of air pollution monitoring and regulation, which has been principally at the intermediate scale of urban outdoor air quality, is no longer adequate. The shift in perception has revealed a whole new set of sources and control needs along with impacts what far-reaching consequences for human well-being. Important changes in perspective result from the shift in focus to air pollution on a small scale. Not only does another set of impacts become apparent but also a new ordering of priorities for affected populations is revealed. A symptom of this second revolution that has frequently come to public attention in recent years is the growing concern with indoor air pollution. The revolution is due to the realization that health-damaging pollutants must be measured where the people are. Part 1 of this series explains the total exposure assessment revolution as it has occurred in the United States. Part 2 extends the discussion to other countries. Attention is focused on benzene, tetrachloroethylene, p-dichlorobenzene, limonene, and particulates.

Smith, K.R.

1988-10-01

283

Phytoremediation of Soils Contaminated by Chlorinnated Hydrocarbons  

NASA Astrophysics Data System (ADS)

In recent years, the possible use of deep rooted plants for phytoremediation of soil contaminants has been offered as a potential alternative for waste management, particularly for in situ remediation of large volumes of contaminated soils. Major objectives of this study are to evaluate the effectiveness of a warm season grass (Eastern Gamagrass) and a cool season prairie grass (Annual Ryegrass) in the phytoremediation of the soil contaminated with volatile organic compounds e.g., trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,1-trichloroethane (TCA) and to determine the main mechanisms of target contaminant dissipation. The preliminary tests and laboratory scale tests were conducted to identify the main mechanisms for phytoremediation of the target contaminants, and to apply the technique in green house application under field conditions. The results of microcosm and bioreactor experiments showed that volatilization can be the dominant pathway of the target contaminant mass losses in soils. Toxicity tests, conducted in nutrient solution in the growth room, and in the greenhouse, showed that both Eastern gamagrass and Annual ryegrass could grow without harmful effects at up to 400 ppm each of all three contaminants together. Preliminary greenhouse experimentw were conducted with the 1.5 m long and 0.3 m diameter PVC columns. Soil gas concentrations monitored and microbial biomass in bulk and rhizosphere soil, root properties, and contaminant concentration in soil after 100 days were analyzed. The results showed that the soil gas concentration of contaminants has rapidly decreased especially in the upper soil and the contaminant concentraitons in soil were also significantly decreased to 0.024, 0.228, and 0.002 of C/Co for TCE, PCE and TCA, respectively. Significant plant effects were not found however showed contaminant loss through volatilization and plant contamination by air.

Cho, C.; Sung, K.; Corapcioglu, M.

2001-12-01

284

Relation of organic contaminant equilibrium sorption and kinetic uptake in plants  

USGS Publications Warehouse

Plant uptake is one of the environmental processes that influence contaminant fate. Understanding the magnitude and rate of plant uptake is critical to assessing potential crop contamination and the development of phytoremediation technologies. We determined (1) the partition-dominated equilibrium sorption of lindane (LDN) and hexachlorobenzene (HCB) by roots and shoots of wheat seedlings, (2) the kinetic uptake of LDN and HCB by roots and shoots of wheat seedlings, (3) the kinetic uptake of HCB, tetrachloroethylene (PCE), and trichloroethylene (TCE) by roots and shoots of ryegrass seedlings, and (4) the lipid, carbohydrate, and water contents of the plants. Although the determined sorption and the plant composition together suggest the predominant role of plant lipids for the sorption of LDN and HCB, the predicted partition with lipids of LDN and HCB using the octanol-water partition coefficients is notably lower than the measured sorption, due presumably to underestimation of the plant lipid contents and to the fact that octanol is less effective as a partition medium than plant lipids. The equilibrium sorption or the estimated partition can be viewed as the kinetic uptake limits. The uptakes of LDN, PCE, and TCE from water at fixed concentrations increased with exposure time in approach to steady states. The uptake of HCB did not reach a plateau within the tested time because of its exceptionally high partition coefficient. In all of the cases, the observed uptakes were lower than their respective limits, due presumably to contaminant dissipation in and limited water transpiration by the plants. ?? 2005 American Chemical Society.

Li, H.; Sheng, G.; Chiou, C.T.; Xu, O.

2005-01-01

285

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

SciTech Connect

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%.

Elmore, B.B.

1993-08-01

286

A purge and trap integrated microGC platform for chemical identification in aqueous samples.  

PubMed

The majority of current micro-scale gas chromatography (?GC) systems focus on air sampling to detect volatile organic compounds (VOCs). However, purging the VOCs from a water sample using microsystems is an unchartered territory. Various organic compounds used in everyday life find their way to water bodies. Some of these water organic compounds (WOCs) persist or degrade slowly, threatening not just human existence but also aquatic life. This article reports the first micro-purge extractor (?PE) chip and its integration with a micro-scale gas chromatography (?GC) system for the extraction and analysis of water organic compounds (WOCs) from aqueous samples. The 2 cm × 3 cm ?PE chip contains two inlet and outlet ports and an etched cavity sealed with a Pyrex cover. The aqueous sample is introduced from the top inlet port while a pure inert gas is supplied from the side inlet to purge WOCs from the ?PE chip. The outlets are assigned for draining water from the chip and for directing purged WOCs to the micro-thermal preconcentrator (?TPC). The trapped compounds are desorbed from the ?TPC by resistive heating using the on-chip heater and temperature sensor, are separated by a 2 m long, 80 ?m wide, and 250 ?m deep polydimethylsiloxane (OV-1) coated ?GC separation column, and are identified using a micro-thermal conductivity detector (?TCD) monolithically integrated with the column. Our experiments indicate that the combined system is capable of providing rapid chromatographic separation (<1.5 min) for quaternary WOCs namely toluene, tetrachloroethylene (PCE), chlorobenzene and ethylbenzene with a minimum detection concentration of 500 parts-per-billion (ppb) in aqueous samples. The proposed method is a promising development towards the future realization of a miniaturized system for sensitive, on-site and real-time field analysis of organic contaminants in water. PMID:24837988

Akbar, Muhammad; Narayanan, Shree; Restaino, Michael; Agah, Masoud

2014-07-01

287

Assessment of soil-gas contamination at three former fuel-dispensing sites, Fort Gordon, Georgia, 2010—2011  

USGS Publications Warehouse

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.

Caldwell, Andral W.; Falls, W. Fred; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

2012-01-01

288

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

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.

Sloto, Ronald A.

2007-01-01

289

Dissolution Coupled Biodegradation of Pce by Inducing In-Situ Biosurfactant Production Under Anaerobic Conditions  

NASA Astrophysics Data System (ADS)

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.

Dominic, J.; Nambi, I. M.

2013-12-01

290

Bedrock geology and outcrop fracture trends in the vicinity of the Savage Municipal Well Superfund site, Milford, New Hampshire  

USGS Publications Warehouse

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.

Burton, William C.; Harte, Philip T.

2013-01-01

291

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

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.

Harte, Philip T.

2013-01-01

292

Final report on CCM key comparison CCM.D-K2: Comparison of liquid density standards  

NASA Astrophysics Data System (ADS)

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).

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

293

Simultaneous determination of bisphenol A and bisphenol B in beverages and powdered infant formula by dispersive liquid-liquid micro-extraction and heart-cutting multidimensional gas chromatography-mass spectrometry.  

PubMed

The purpose of this study was to establish a reliable, cost-effective, fast and simple method to quantify simultaneously both bisphenol A (BPA) and bisphenol B (BPB) in liquid food matrixes such as canned beverages (soft drinks and beers) and powdered infant formula using dispersive liquid-liquid micro-extraction (DLLME) with in-situ derivatisation coupled with heart-cutting gas chromatography-mass spectrometry (GC-MS). For the optimisation of the DLLME procedure different amounts of various extractive and dispersive solvents as well as different amounts of the derivative reagent were compared for their effects on extraction efficiency and yields. The optimised procedure consisted of the injection of a mixture containing tetrachloroethylene (extractant), acetonitrile (dispersant) and acetic anhydride (derivatising reagent) directly into an aliquot of beverage samples or into an aqueous extract of powdered milk samples obtained after a pretreatment of the samples. Given the compatibility of the solvents used, and the low volumes involved, the procedure was easily associated with GC-MS end-point determination, which was accomplished by means of an accurate GC dual column (heart-cutting) technique. Careful optimisation of heart-cutting GC-MS conditions, namely pressure of front and auxiliary inlets, have resulted in a good analytical performance. The linearity of the matrix-matched calibration curves was acceptable, with coefficients of determination (r2) always higher than 0.99. Average recoveries of the BPA and BPB spiked at two concentration levels into beverages and powdered infant formula ranged from 68% to 114% and the relative standard deviation (RSD) was <15%. The limits of detection (LOD) in canned beverages were 5.0 and 2.0 ng l(-1) for BPA and BPB, respectively, whereas LOD in powdered infant formula were 60.0 and 30.0 ng l(-1), respectively. The limits of quantification (LOQ) in canned beverages were 10.0 and 7.0 ng l-1 for BPA and BPB, respectively, whereas LOQ in powdered infant formula were 200.0 and 100.0 ng l(-1), respectively. BPA was detected in 21 of 30 canned beverages (ranging from 0.03 to 4.70 µg l(-1)) and in two of seven powdered infant formula samples (0.23 and 0.40 µg l(-1)) collected in Portugal. BPB was only detected in canned beverages being positive in 15 of 30 samples analysed (ranging from 0.06 to 0.17 µg l(-1)). This is the first report about the presence of BPA and BPB in canned beverages and powdered infant formula in the Portuguese market. PMID:21240700

Cunha, S C; Almeida, C; Mendes, E; Fernandes, J O

2011-04-01

294

Assessing the vulnerability of public-supply wells to contamination—High Plains Aquifer near York, Nebraska  

USGS Publications Warehouse

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program found, in studies from 1991 to 2001, low levels of mixtures of contaminants in ground water near the water table in urban areas across the Nation. Although contaminants were detected less frequently in deeper ground water typically developed for public supply the proximity of contaminant mixtures to underlying public-water-supply sources prompted the NAWQA Program to begin, in 2001, an intensive study to assess the vulnerability of public-supply wells to contamination. As part of this study, the pathways and processes by which contaminants reach public-supply wells in nine aquifer systems across the country are being investigated. In addition to studying the processes that occur below land surface—whereby contaminants are mobilized or attenuated—scientists are also investigating how human activities can affect the vulnerability of public-supply wells to contamination. This fact sheet highlights findings from two reports on the vulnerability study of a single, representative public-supply well in York, Nebraska. The selected high-capacity well typically produces more than 720,000 gallons per day from the upper confined aquifer of the High Plains aquifer. A possible source of contamination to the well is intensive, irrigated agriculture, which can sometimes result in elevated concentrations of nitrate and pesticides in ground water. In addition, a sampling of the selected public-supply well by the USGS in 2002 found low concentrations of the solvents trichloroethylene (TCE), tetrachloroethylene (PCE), and their degradation products, which may be linked to historical chemical use in urban and residential areas of York. Uranium and arsenic (which occur naturally in the sediments that make up the aquifers in the area) also were detected in 2002 at concentrations less than drinking-water standards but still of concern. Overall, the current NAWQA study found that three primary factors affect the movement and fate of contaminants and the vulnerability of the public-supply well in York: (1) timing of water entry (recharge) to the aquifer, (2) short-circuiting of natural flow paths through inactive wells, and (3) natural geochemical conditions of the aquifer. Study findings are intended to help water managers, drinking-water suppliers, policymakers, and scientists to better understand how and why contamination of public-supply wells occurs and whether water quality may improve or degrade. Additionally, study findings may be used to evaluate various pumping, resource-development, and land-management scenarios.

Jagucki, Martha L.; Landon, Matthew K.; Clark, Brian R.; Eberts, Sandra M.

2008-01-01

295

DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS  

SciTech Connect

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.

Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

2012-09-20

296

Development and Application of a 3-Dimensional Finite Element Model for Remediation Wellfield Management at Lawrence Livermore National Laboratory  

NASA Astrophysics Data System (ADS)

Lawrence Livermore National Laboratory (LLNL), which is on the Superfund National Priorities List, is implementing an extensive ground water remediation program. The environmental investigation covers an area of about 2 square miles, and is underlain by a thick sequence of heterogeneous alluvial sediments. These sediments have been subdivided into hydrostratigraphic units (HSUs) bounded by thin confining layers that were identified using a deterministic approach. LLNL currently operates a large ground water extraction system that includes 80 ground water extraction wells connected to 25 separate treatment facilities. These combined facilities treated about 308 million gallons of ground water at an average combined flow rate of 600 gpm, and removed about 270 kg of volatile organic compounds (VOC's). To better manage this large complex remediation system, a 3-dimensional, finite-element numerical model was developed using FEFLOW. The model simulated a 7 square-mile portion of the large Livermore Valley ground water basin. The quality of the input data varied from highly detailed, in the environmental investigation areas, to sparse, near some of the model domain boundaries. These different data sets had to be integrated to obtain the necessary boundary conditions and input parameters for the model. Hydraulic conductivities were averaged from measured lithologic descriptions and hydraulic test data. Boundary conditions were based on a local and regional assessment of groundwater elevation data representative of observed inflow/outflow boundaries. The model was initially calibrated to a set of 8 distinct hydrologic stress periods over 12 years. Initial flow calibration for the model was achieved using the parameter estimation tool PEST. Through successive data analysis and calibration, optimal parameters were established for each HSU and expanded to 35 hydrologic stress periods covering the entire recorded hydrologic history. VOC transport was calibrated to 9 years of historical data for tetrachloroethylene (PCE) and trichloroethylene (TCE). There is good agreement between observed and calculated PCE and TCE plume migration and response to remediation activities. The calibrated model is currently being applied to optimize groundwater remediation efforts by testing wellfield management strategies and to assist with long term budgeting and planning purposes. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Mansoor, K.; Maley, M. P.; Demir, Z.; Noyes, C.

2001-12-01

297

Underestimated public health risks caused by overestimated VOC removal in wastewater treatment processes.  

PubMed

The uncontrolled release of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) and the adverse health effects on the public have been of increasing concern. In this study, a lab-scale bioreactor was prepared to analyze the mass distribution of three aromatic (benzene, toluene, and xylenes) and four chlorinated VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) among the air, water and sludge phases in wastewater treatment processes. The VOC distribution through a full-scale WWTP in northern China was further investigated with respect to the effects of seasonal temperature variations and treatment technologies, followed by the cancer risk assessment using a steady-state Gaussian plume model (Industrial Source Complex) to simulate the atmospheric behaviors of the VOCs emitted from the WWTP. It was found that three aromatic hydrocarbons, notably benzene, were more readily released from the wastewater into the atmosphere, whereas the chlorinated compounds except chloroform were mainly present in the water phase through the treatment processes. The primary clarifier was the technology releasing high levels of VOCs into the atmosphere from the wastewater. The extents of volatilization or biodegradation, two important mechanisms to remove VOCs from wastewater, appeared to be determined by the physicochemical characteristics of the compounds, as the influence of treatment technologies (e.g., aeration) and seasonal temperature variations was rather limited. More importantly, the people living in the areas even more than 4 km away from the WWTP were still potentially exposed to cancer risks exceeding the regulatory threshold limit. The findings described the complex nature of VOC emissions from WWTPs and quantitatively indicated that the associated health impacts on the public near the WWTPs could be severely underestimated, whereas their treatment efficiencies by wastewater treatment technologies were overestimated. Instead of fully controlling the VOC release from WWTPs, the identification and abatement of important VOC species with regard to the atmospheric emission and health concerns is one possible alternative approach to effectively minimize the environmental and public health impacts by VOCs released from this particular source. PMID:24337048

Yang, Junchen; Wang, Kun; Zhao, Qingliang; Huang, Likun; Yuan, Chung-Shin; Chen, Wei-Hsiang; Yang, Wen-Bin

2014-02-01

298

GE/NOMADICS IN-WELL MONITORING SYSTEM FOR VERTICAL PROFILING OF DNAPL CONTAMINANTS  

SciTech Connect

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.

Ronald E. Shaffer; Radislav Potyralio; Joseph Salvo; Timothy Sivavec; Lloyd Salsman

2003-04-01

299

Streambed-material characteristics and surface-water quality, Green Pond Brook and tributaries, Picatinny Arsenal, New Jersey, 1983-90  

USGS Publications Warehouse

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.

Storck, D.A.; Lacombe, Pierre

1996-01-01

300

Cracking of Clay Due to Contact with Waste Chlorinated Solvents  

NASA Astrophysics Data System (ADS)

Clays are known to crack upon desiccation. Desiccation cracks of up to 3 cm wide have been reported in natural soils. This raises the question if a similar behavior is seen when a dense non-aqueous phase liquids (DNAPL) waste is in contact with clay. The contact with organic liquids causes the clay structure to shrink, leading to the formation of cracks. Moreover, DNAPL waste not only contains the organic liquid solvent but also includes surface-active solutes or surfactants. Such solutes can enhance the interaction of the organic solvents with the clay. This research will assess whether or not contact with chlorinated organic waste causes cracking. In order to evaluate the possibility of cracking in the clay, microcosms have been constructed that mimic aquifer systems, consisting of a saturated layer of sand, a saturated layer of bentonite clay and a 2.5 cm layer of either pure chlorinated solvents or DNAPL waste. The onset of cracking for the microcosm with tetrachloroethylene (PCE) waste as the DNAPL layer occurred after ten days of contact. Similarly, at eight days, cracks were observed in a microcosm containing trichloroethylene (TCE) waste . Forty-four days later, the length and number of cracks have grown considerably; with a total crack length of 50 cm on a surface of 80 cm2 in the microcosm containing PCE waste. On the other hand it took approximately 161 days for the clay layer in the microcosm containing pure PCE to crack. To quantity the degree of cracking, crack maps were developed using the image software, Image J. Characteristics like crack length, crack aperture, and the percentage of total length for a range of apertures were calculated using this software. For example, for the PCE waste microcosm, it was calculated that 3.7% of the crack length had an aperture of 100-300 microns, 15.1% of the crack length had an aperture of 300-500 microns, 29.7% of the crack length had an aperture of 500-700 microns, 40.1% of the crack length had an aperture of 700-900 microns, 6.3% had an aperture of 900-1,100 microns and 5.1% had an aperture of over 1,100 microns. These data suggest that aquitards in the field might crack when in contact with the DNAPL waste. Moreover, it is apparent that the waste contains solutes that accelerate the cracking of the clay layer. Thus, models examining the impact of storage in low permeability layers need to consider the possible impact of cracking.

Otero, M.; Ayral, D.; Shipan, J.; Goltz, M. N.; Huang, J.; Demond, A. H.

2012-12-01

301

In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers  

NASA Astrophysics Data System (ADS)

Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the microbial cultures. The microorganisms responsible for biosurfactant production was isolated and identified as Pseudomonas Sp (designated as Pseudomonas Sp ANBIOSURF-1, Gene bank no: FJ930079), Pseudomonas stutzeri (MTCC 10033), Pseudomonas Sp (MTCC 10032) from groundwater, soil and municipal sewage sludge enrichments respectively. This study confirms that biosurfactants can be produced under anaerobic conditions and also in sufficient quantities. The cultures were also able to cometabolically degrade PCE to Ethylene. The isolated microorganisms can be used for remediation of DNAPL contaminated sites by in-situ biosurfactant production.

Albino, J. D.; Nambi, I. M.

2009-12-01

302

Responses of the L5178Y tk+/tk- mouse lymphoma cell forward mutation assay: III. 72 coded chemicals.  

PubMed

Seventy-two chemicals were tested for their mutagenic potential in the L5178Y tk+/- mouse lymphoma cell forward mutation assay, using procedures based upon those described by Clive and Spector (Mutat Res 44:269-278, 1975) and Clive et al. (Mutat Res 59:61-108, 1979). Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 micrograms/ml. The chemicals were tested at least twice. Significant responses were obtained with allyl isothiocyanate, p-benzoquinone dioxime, benzyl acetate, 2-biphenylamine HCl, bis(2-chloro-1-methylethyl)ether, cadmium chloride, chlordane, chlorobenzene, chlorobenzilate, 2-chloroethanol, chlorothalonil, cytarabine.HCl, p,p'-DDE, diazinon, 2,6-dichloro-p-phenylenediamine, N,N-diethylthiourea, diglycidylresorcinol ether, 2,4-dimethoxy aniline.HCl, disperse yellow 3, endosulfan, 1,2-epoxyhexadecane, ethyl acrylate, ethyl benzene, ethylene thiourea, F D and C yellow Number 6, furan, heptachlor, isophorone, mercuric chloride, 4,4'-methylenedianiline.2 HCl, methyl viologen, nickel sulfate.6H2O, 4,4'-oxydianiline, pentachloroethane, piperonyl butoxide, propyl gallate, quinoline, rotenone, 2,4,5,6-tetrachloro-4-nitro-anisole, 1,1,1,2-tetrachloroethane, trichlorfon, 2,4,6-trichlorophenol, 2,4,5-trimethoxybenzaldehyde, 1,1,3-trimethyl-2-thiourea, 1-vinyl-3-cyclopetene dioxide, vinyl toluene, and ziram. Apart from 2-biphenylamine.HCl, 2-chloroethanol, disperse yellow 3, ethylene thiourea, FD and C yellow number 6, phenol, and 1,1,2-tetrachloroethane, rat liver S9 mix was not a requirement for these compounds. Chemicals not identified as mutagens were acid red, 11-aminoudecanoic acid, boric acid, 5-chloro-o-toluidine, coumaphos, cyclohexanone, decabromodiphenyl oxide, di(2-ethylhexyl)adipate, ferric chloride, fluometuron, melamine, monuron, phenesterin, phthalimide, reserpine, sodium dodecyl sulfate, 4,4-sulfonyldianiline, tetrachloroethylene, and zearalenone. The assay was incapable of providing a clear indication of whether some chemicals were mutagens; these were benzyl alcohol, 1,4-dichlorobenzene, phenol, succinic acid-2,2-dimethyl hydrazide, and toluene. PMID:3383842

McGregor, D B; Brown, A; Cattanach, P; Edwards, I; McBride, D; Riach, C; Caspary, W J

1988-01-01

303

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

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.

Holloway, Owen G.; Waddell, Jonathan P.

2008-01-01

304

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

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.

Williams, Shannon D.

2003-01-01

305

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

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.

Harte, Philip T.

2006-01-01

306

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

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.

Harte, Philip T.

2010-01-01

307

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

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.

Sullivan, Daniel J.; Stinson, Troy W.; Crawford, J. Kent; Schmidt, Arthur R.; Colman, John A.

1998-01-01

308

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

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.

Sloto, Ronald A.; Goode, Daniel J.; Frasch, Steven M.

2002-01-01

309

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

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.

Senior, Lisa A.; Goode, Daniel J.

1999-01-01

310

Polymer coated gold nanoparticles for tracing the mobility of engineered nanoparticles in the subsurface  

NASA Astrophysics Data System (ADS)

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.

Uthuppu, Basil; Sidelmann Fjordbøge, Annika; Caspersen, Eva; Broholm, Mette Martina; Havsteen Jakobsen, Mogens

2014-05-01

311

Injection of Emulsified Vegetable Oil for Long-Term Bioreduction of Uranium  

NASA Astrophysics Data System (ADS)

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.

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

312

California GAMA program: ground-water quality data in the San Diego drainages hydrogeologic province, California, 2004  

USGS Publications Warehouse

Because of concerns over ground-water quality, the California State Water Resources Control Board (SWRCB), in collaboration with the U.S. Geological Survey and Lawrence Livermore National Laboratory, has implemented the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. A primary objective of the program is to provide a current assessment of ground-water quality in areas where public supply wells are an important source of drinking water. The San Diego GAMA study unit was the first region of the state where an assessment of ground-water quality was implemented under the GAMA program. The San Diego GAMA study unit covers the entire San Diego Drainages hydrogeologic province, and is broken down into four distinct hydrogeologic study areas: the Temecula Valley study area, the Warner Valley study area, the Alluvial Basins study area, and the Hard Rock study area. A total of 58 ground-water samples were collected from public supply wells in the San Diego GAMA study unit: 19 wells were sampled in the Temecula Valley study area, 9 in the Warner Valley study area, 17 in the Alluvial Basins study area, and 13 in the Hard Rock study area. Over 350 chemical and microbial constituents and water-quality indicators were analyzed for in this study. However, only select wells were measured for all constituents and water-quality indicators. Results of analyses were calculated as detection frequencies by constituent classification and by individual constituents for the entire San Diego GAMA study unit and for the individual study areas. Additionally, concentrations of constituents that are routinely monitored were compared to maximum contaminant levels (MCL) and secondary maximum contaminant levels (SMCL). Concentrations of constituents classified as 'unregulated chemicals for which monitoring is required' (UCMR) were compared to the 'detection level for the purposes of reporting' (DLR). Eighteen of the 88 volatile organic compounds (VOCs) and gasoline oxygenates analyzed for were detected in ground-water samples. Twenty-eight wells sampled in the San Diego GAMA study had at least a single detection of VOCs or gasoline oxygenates. These constituents were most frequently detected in the Alluvial Basin study area (11 of 17 wells), and least frequently detected in the Warner Valley study area (one of nine wells). Trihalomethanes (THMs) were the most frequently detected class of VOCs (18 of 58 wells). The most frequently detected VOCs were chloroform (18 of 58 wells), bromodichloromethane (8 of 58 wells), and methyl tert-butyl ether (MTBE) (7 of 58 wells). Three VOCs were detected at concentrations greater than their MCLs. Tetrachloroethylene (PCE) and trichloroethylene (TCE) were detected in one well in the Hard Rock study area at concentrations of 9.75 and 7.27 micrograms per liter (?g/L), respectively; the MCL for these compounds is 5 ?g/L. MTBE was detected in one well in the Alluvial Basins study area at a concentration of 28.3 ?g/L; the MCL for MTBE is 13 ?g/L. Twenty-one of the 122 pesticides and pesticide degradates analyzed for were detected in ground-water samples. Pesticide or pesticide degradates were detected in 33 of 58 wells sampled, and were most frequently detected in the Temecula Valley study area wells (9 of 14 wells), and least frequently in the Warner Valley study area wells (3 of 9 wells). Herbicides were the most frequently detected class of pesticides (31 of 58 wells), and simazine was the most frequently detected compound (27 of 58 wells), followed by deethylatrazine (14 of 58 wells), prometon (10 of 58 wells), and atrazine (9 of 58 wells). None of the pesticides detected in ground-water samples had concentrations that exceeded MCLs. Eight waste-water indicator compounds were detected in ground-water samples. Twenty-one of 47 wells sampled for waste-water indicator compounds had at least a single detection. Waste-water indicator compounds were detected most frequently in the Allu

Wright, Michael T.; Belitz, Kenneth; Burton, Carmen A.

2005-01-01

313

Reactive hydro- end chlorocarbons in the troposphere and lower stratosphere : sources, distributions, and chemical impact  

NASA Astrophysics Data System (ADS)

The work presented in this thesis focuses on measurements of chemical reactive C2 C7 non-methane hydrocarbons (NMHC) and C1 C2 chlorocarbons with atmospheric lifetimes of a few hours up to about a year. The group of reactive chlorocarbons includes the most abundant atmospheric species with large natural sources, which are chloromethane (CH3Cl), dichloromethane (CH2Cl2), and trichloromethane (CHCl3), and tetrachloroethylene (C2Cl4) with mainly anthropogenic sources. The NMHC and chlorocarbons are present at relatively low quantities in our atmosphere (10-12 10-9 mol mol-1 of air). Nevertheless, they play a key role in atmospheric photochemistry. For example, the oxidation of NMHC plays a dominant role in the formation of ozone in the troposphere, while the photolysis of chlorocarbons contributes to enhanced ozone depletion in the stratosphere. In spite of their important role, however, their global source and sinks budgets are still poorly understood. Hence, this study aims at improving our understanding of the sources, distribution, and chemical role of reactive NMHC and chlorocarbons in the troposphere and lower stratosphere. To meet this aim, a comprehensive data set of selected C2 C7 NMHC and chlorocarbons has been analyzed, derived from six aircraft measurement campaigns with two different jet aircrafts (the Dutch TUD/NLR Cessna Citation PH-LAB, and the German DLR Falcon) conducted between 1995 and 2001 (STREAM 1995 and 1997 and 1998, LBA-CLAIRE 1998, INDOEX 1999, MINOS 2001). The NMHC and chlorocarbons have been detected by gas-chromatography (GC-FID/ECD) in pre-concentrated whole air samples collected in stainless steel canister on-board the measurement aircrafts. The measurement locations include tropical (Maldives/Indian Ocean and Surinam), midlatitude (Western Europe and Canada) and polar regions (Lapland/northern Sweden) between the equator to about 70ºN, covering different seasons and pollution levels in the troposphere and lower stratosphere. Of special interest in this thesis are the tropical regions because they are becoming increasingly important in terms of global anthropogenic pollution and climate change. In addition, natural emissions of hydrocarbons (notably isoprene and terpenes from plants) and reactive chlorocarbons appear to be concentrated in the tropics, where the largest uncertainties exist with respect to source type and source strength. Whenever available, the reactive NMHC and chlorocarbon data have been analyzed with the help of concurrent measurements, which includes ozone (O3), carbon monoxide (CO), nitrogen oxide (NO), total reactive oxidized nitrogen (NOy), nitrous oxide (N2O), carbon dioxide (CO2), methane (CH4), acetone (CH3COCH3), methanol (CH3OH), acetonitrile (CH3CN), the chlorofluorocarbons CFC-11 (CCl3F) and CFC-12 (CCl2F2), the hydrofluorocarbon HFC-134a (CH2FCF3), and the hydrochlorofluorocarbons HCFC-141b (CH3CCl2F) and HCFC-142b (CH3CClF2). These additional measurements provided important information about the air mass origin, pollution sources, and chemical age of the encountered air masses. The STREAM-measurements contribute to the present understanding of the budgets of reactive organic trace species in the mid-latitude lower stratosphere at different seasonal conditions. It was found that during summer and fall, the mean concentrations of reactive NMHC and acetone in the lower stratosphere were a factor of two or more higher than during winter, as a result of more intense and frequent mixing across the tropopause. The role of tropical emissions in the global budget of hydrocarbons and the chlorocarbons CH3Cl, CH2Cl2, CHCl3, and C2Cl4 has been investigated during the LBA/CLAIRE 1998, INDOEX 1999 and MINOS 2001 campaigns. The INDOEX measurements over the Indian Ocean showed that strongly enhanced CH3Cl and related combustion tracers, such as CO, hydrocarbons and CH3CN in polluted air masses from India and Southeast Asia, relate to the extensive use of biofuels (notably the burning of agricultural waste and dung) in households and small industries. During the MINOS campaign

Scheeren, H. A.

2003-09-01

314

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

NASA Astrophysics Data System (ADS)

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 contaminants. As well known, TCE is wisely used industrial activities such as degreasing, metal stripping, chemical manufacturing, pesticide production, coal gasification plants, creosote operation, and also used in automobile service centers, photo shops and laundries as cleaning solvent. Thus, groundwater protection in urban areas is important issue in Korea This study is to understand groundwater quality and contamination characteristics and to estimate risk assessment in Sasang industrial complex, Busan Metropolitan City. Busan Metropolitan City is located on southeastern coast of the Korean peninsula and is the second largest city in South Korea with a population of 3.8 millions. The geology of the study area is composed of andesite, andesitic tuff, biotite granite and alluvium (Kim et al., 1998). However, geology cannot be identified on the surface due to pavement and buildings. According to drill logs in the study area, the geologic section consists in landfill, fine sand, clay, gravelly clay, and biotite granite from the surface. Biotite granite appears 5.5- 6 m depth. Groundwater samples were collected at twenty sites in Sasang industrial complex. The groundwater samples are plotted on Piper's trilinear diagram, which indicates Ca-Cl2 type. The groundwater may be influenced by salt water because Sasang industrial complex is located near the mouse of Nakdong river that flows to the South Sea. The Ca-Cl2 water type may be partly influenced by anthropogenic contamination in the study area, since water type in granite area generally belongs Ca-HCO3 or Na-HCO3 types. TDS (107-14,500 /L), EC (225-25,500 ?S/cm), salinity (100-15,500 /kg), Na+ (13.39-2,866 /L) and Cl- (15.3-7,066 /L) concentrations are also higher than those of general groundwater. This fact indicates that groundwater in study area was polluted by saline water and/or anthropogenic sources. TCE, PCE, 1.1.1-trichloroethane (TCA) were analyzed by Busan Metropolitan City Institute of Health &Environment. PCE and TCA are not detected most of sites, while TCE is detected most of the sites and exceeds drinking water standard of Korea 0.03 /L. It is considered that TCE was derived from variety contamination sources such as car-washing centers, transportation companies, iron molding factories and waste treating companies. Risk assessment to human health and environmental resources by groundwater contamination was conducted. The RBCA Tool Kit for Chemical Releases can be used for the risk assessment at Tier 1 and Tier 2. The risk assessment determines risk-based concentration of constituents of concerns (COCs) that moves through groundwater, soil and air. It also evaluates carcinogenic risk and toxic effect when receptor exposures to the COCs. Tier 1 analysis determines risk-based screening levels (RBSLs) for one-site exposure. Tier 2 analysis evaluates RBSL and/or site-specific target levels (SSTLs) for both on-site and off-site receptor. RBSLs were calculated as 2.2E-2 /L for TCE and as 4.7E-3 /L for PCE at Tier 1 risk assessment. Average concentrations of TCE and PCE from measuring the groundwater samples were 0.15 mg/L and 0.016 mg/L, respectively. The actual measured values are higher than the RBSLs. Carcinogenic risk of TCE to animals was identified as B2 (inadequate or no human evidence but sufficient animal evidence). From this result, we will conduct the further detail risk assessment at Tier 2 level before conducting groundwater remediation. ACKNOWLEDGEMENT The authors wish to acknowledge the financial support of the Korea Science &Engineering Foundation (KOSEF) under the Basic Research Program (grant no: R02-2001-00249).

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

2003-04-01

315

Final Technical Report: Effects of Impurities on Fuel Cell Performance and Durability  

SciTech Connect

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

James G. Goodwin, Jr.; Hector Colon-Mercado; Kitiya Hongsirikarn; and Jack Z. Zhang

2011-11-11