Note: This page contains sample records for the topic hydrocarbon contaminated subsurface from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Presence of Actinobacterial and Fungal Communities in Clean and Petroleum Hydrocarbon Contaminated Subsurface Soil  

PubMed Central

Relatively little is known about the microbial communities adapted to soil environments contaminated with aged complex hydrocarbon mixtures, especially in the subsurface soil layers. In this work we studied the microbial communities in two different soil profiles down to the depth of 7 m which originated from a 30-year-old site contaminated with petroleum hydrocarbons (PHCs) and from a clean site next to the contaminated site. The concentration of oxygen in the contaminated soil profile was strongly reduced in soil layers below 1 m depth but not in the clean soil profile. Total microbial biomass and community composition was analyzed by phospholipid fatty acid (PLFA) measurements. The diversity of fungi and actinobacteria was investigated more in detail by construction of rDNA-based clone libraries. The results revealed that there was a significant and diverse microbial community in subsoils at depth below 2 m, also in conditions where oxygen was limiting. The diversity of actinobacteria was different in the two soil profiles; the contaminated soil profile was dominated by Mycobacterium -related sequences whereas sequences from the clean soil samples were related to other, generally uncultured organisms, some of which may represent two new subclasses of actinobacteria. One dominating fungal sequence which matched with the ascomycotes Acremonium sp. and Paecilomyces sp. was identified both in clean and in contaminated soil profiles. Thus, although the relative amounts of fungi and actinobacteria in these microbial communities were highest in the upper soil layers, many representatives from these groups were found in hydrocarbon contaminated subsoils even under oxygen limited conditions.

Bjorklof, Katarina; Karlsson, Sanja; Frostegard, Asa; J?rgensen, Kirsten S

2009-01-01

2

Intrinsic Anaerobic Bioremediation of Hydrocarbons in Contaminated Subsurface Plumes and Marine Sediments  

NASA Astrophysics Data System (ADS)

In recent years, several classes of petroleum hydrocarbons contaminating subsurface and marine environments have been found susceptible to anaerobic biodegradation using novel mechanisms entirely distinct from aerobic metabolic pathways. For example, the anaerobic decay of toluene can be initiated by the addition of the aryl methyl group to the double bond of fumarate, resulting in a benzylsuccinic acid metabolite. Our work has shown that an analogous mechanism also occurs with ethylbenzene and the xylene isomers, yielding 3-phenyl-1,2-butane dicarboxylic acid and methylbenzylsuccinic acid, respectively. Moreover, these metabolites have been detected in contaminated environments. Most recently, we have identified metabolites resulting from the initial attack of H26- or D26-n-dodecane during degradation by a sulfate-reducing bacterial culture. Using GC-MS, these metabolites were identified as fatty acids that result from C-H or C-D addition across the double bond of fumarate to give dodecylsuccinic acids in which all 26 protons or deuteriums of the parent alkane were retained. Further, when this enrichment culture was challenged with hexane or decane, hexylsuccinic acid or decylsuccinic acid were identified as resulting metabolites. Similarly, the study of an ethylcyclopentane-degrading sulfate-reducing enrichment produced a metabolite, which is consistent with the addition of fumarate to the parent substrate. These novel anaerobic addition products are characterized by similar, distinctive mass spectral (MS) features (ions specific to the succinic acid portion of the molecule) that can potentially be used to probe contaminated environments for evidence of intrinsic remediation of hydrocarbons. Indeed, analyses of water extracts from two gas condensate-contaminated sites resulted in the tentative detection of alkyl- and cycloalkylsuccinic acids ranging from C3 to C9, including ethylcyclopentyl-succinic acid. In water extracts collected from an area underlying a petroleum production plant, MS profiles consistent with the addition products of methylcycloalkenes were observed. This work helps attests to: 1) the extrapolatability of laboratory results to the field, 2) the unifying metabolic features for the anaerobic destruction of diverse types of hydrocarbons, and 3) how this information can be used to assess the intrinsic bioremediation processes in petroleum-contaminated environments.

Nanny, M. A.; Nanny, M. A.; Suflita, J. M.; Suflita, J. M.; Davidova, I.; Kropp, K.; Caldwell, M.; Philp, R.; Gieg, L.; Rios-Hernandez, L. A.

2001-05-01

3

Contamination of polycyclic aromatic hydrocarbons (PAHs) in microlayer and subsurface waters along Alexandria coast, Egypt  

Microsoft Academic Search

The residues of seven polycyclic aromatic hydrocarbons (PAHs) pollutants in microlayer and subsurface seawater samples collected from Alexandria coast, Egypt, were analyzed by gas chromatography–electron-impact mass spectrometry-selected ion monitoring mode (GC–MS-SIM). The pollutants studied were, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene and benzo[a]pyrene. Total PAH levels in microlayer ranged from 103 to 523 ng\\/l, while it ranged in subsurface samples

Ahmed El Nemr; Aly M. A. Abd-Allah

2003-01-01

4

Microbial biomass and activities associated with subsurface environments contaminated with chlorinated hydrocarbons  

SciTech Connect

Soil microcosms and enrichment cultures from subsurface sediments and ground waters contaminated with trichloroethylene (TCE) were examined. Total lipids, (1-C{sub 14})acetate incorporation into lipids, and (Me{sup 3}H)thymidine incorporation into DNA were determined in these subsurface environments. In heavily TCE-contaminated zones radioisotopes were not incorporated into lipids or DNA. Radioisotope incorporation occurred in sediments both above and below the TCE plume. Phospholipid fatty acids (PLFA) were not detected, i.e., < 0.5 pmol/L in heavily contaminated groundwater samples. In less contaminated waters, extracted PLFA concentrations were greater than 100 pmol/L and microbial isolates were readily obtained. Degradation of 30-100 mg/L TCE was observed when sediments were amended with a variety of energy sources. Microorganisms in these subsurface sediments have adapted to degrade TCE at concentrations greater than 50 mg/L. 34 refs., 4 figs., 4 tabs.

Phelps, T.J.; Ringelberg, D.; Hedrick, D.; Davis, J.; Fliermans, C.B. (Univ. of Tennessee, Knoxville (USA))

1988-01-01

5

Contamination of polycyclic aromatic hydrocarbons (PAHs) in microlayer and subsurface waters along Alexandria coast, Egypt.  

PubMed

The residues of seven polycyclic aromatic hydrocarbons (PAHs) pollutants in microlayer and subsurface seawater samples collected from Alexandria coast, Egypt, were analyzed by gas chromatography-electron-impact mass spectrometry-selected ion monitoring mode (GC-MS-SIM). The pollutants studied were, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene and benzo[a]pyrene. Total PAH levels in microlayer ranged from 103 to 523 ng/l, while it ranged in subsurface samples from 13 to 120 ng/l. The Western Harbor location recorded the highest level of PAHs pollutant over all the other location for both subsurface and microlayer waters. The two major PAHs in microlayer water at the Western Harbor were fluorene and phenanthrene, making up 27% and 20% of the total PAHs, while the two major PAHs in subsurface water at the Eastern Harbor were phenanthrene and fluoranthene recording up 21% each of the total PAHs. The total PAH levels were generally in the nano-gram per liter for microlayer and subsurface seawater samples. The dominant PAHs in both subsurface and microlayer samples were fluoranthene, pyrene and benzo[a]pyrene. The microlayer enrichment factor at Alexandria's Mediterranean coast was ranged from 29 for fluorene to 3 for phenanthrene and benzo[a]pyrene which showed PAHs concentration in the microlayer with an average of five times more than the total PAH in the subsurface samples. PMID:12871738

El Nemr, Ahmed; Abd-Allah, Aly M A

2003-09-01

6

Use of dissolved and vapor-phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface  

NASA Astrophysics Data System (ADS)

At many sites contaminated with petroleum hydrocarbons, methanogenesis is a significant degradation pathway. Techniques to estimate CH4 production, consumption, and transport processes are needed to understand the geochemical system, provide a complete carbon mass balance, and quantify the hydrocarbon degradation rate. Dissolved and vapor-phase gas data collected at a petroleum hydrocarbon contaminated site near Bemidji, Minnesota, demonstrate that naturally occurring nonreactive or relatively inert gases such as Ar and N2 can be effectively used to better understand and quantify physical and chemical processes related to methanogenic activity in the subsurface. In the vadose zone, regions of Ar and N2 depletion and enrichment are indicative of methanogenic and methanotrophic zones, and concentration gradients between the regions suggest that reaction-induced advection can be an important gas transport process. In the saturated zone, dissolved Ar and N2 concentrations are used to quantify degassing driven by methanogenesis and also suggest that attenuation of methane along the flow path, into the downgradient aquifer, is largely controlled by physical processes. Slight but discernable preferential depletion of N2 over Ar, in both the saturated and unsaturated zones near the free-phase oil, suggests reactivity of N2 and is consistent with other evidence indicating that nitrogen fixation by microbial activity is taking place at this site.

Amos, Richard T.; Mayer, K. Ulrich; Bekins, Barbara A.; Delin, Geoffrey N.; Williams, Randi L.

2005-02-01

7

Subsurface Contamination Control.  

National Technical Information Service (NTIS)

There are two objectives of this report. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second ...

Y. Yuan

2001-01-01

8

Use of dissolved and vapor-phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface  

Microsoft Academic Search

At many sites contaminated with petroleum hydrocarbons, methanogenesis is a significant degradation pathway. Techniques to estimate CH4 production, consumption, and transport processes are needed to understand the geochemical system, provide a complete carbon mass balance, and quantify the hydrocarbon degradation rate. Dissolved and vapor-phase gas data collected at a petroleum hydrocarbon contaminated site near Bemidji, Minnesota, demonstrate that naturally occurring

Richard T. Amos; K. Ulrich Mayer; Barbara A. Bekins; Geoffrey N. Delin; Randi L. Williams

2005-01-01

9

Subsurface Contamination Control  

SciTech Connect

There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of the subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the subsurface repository; (2) provides a table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.

Y. Yuan

2001-12-12

10

Subsurface contaminants focus area  

SciTech Connect

The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

NONE

1996-08-01

11

Delineation of subsurface hydrocarbon contamination at a former hydrogenation plant using spectral induced polarization imaging  

NASA Astrophysics Data System (ADS)

Broadband spectral induced polarization (SIP) measurements were conducted at a former hydrogenation plant in Zeitz (NE Germany) to investigate the potential of SIP imaging to delineate areas with different BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations. Conductivity images reveal a poor correlation with the distribution of contaminants; whereas phase images exhibit two main anomalies: low phase shift values (< 5 mrad) for locations with high BTEX concentrations, including the occurrence of free-phase product (BTEX concentrations > 1.7 g/l), and higher phase values for lower BTEX concentrations. Moreover, the spectral response of the areas with high BTEX concentration and free-phase products reveals a flattened spectrum in the low frequencies (< 40 Hz), while areas with lower BTEX concentrations exhibit a response characterized by a frequency peak. The SIP response was modelled using a Debye decomposition to compute images of the median relaxation-time. Consistent with laboratory studies, we observed an increase in the relaxation-time associated with an increase in BTEX concentrations. Measurements were also collected in the time domain (TDIP), revealing imaging results consistent with those obtained for frequency domain (SIP) measurements. Results presented here demonstrate the potential of the SIP imaging method to discriminate source and plume of dissolved contaminants at BTEX contaminated sites.

Flores Orozco, Adrián; Kemna, Andreas; Oberdörster, Christoph; Zschornack, Ludwig; Leven, Carsten; Dietrich, Peter; Weiss, Holger

2012-08-01

12

EXPOSURE ASSESSMENT MODELING FOR HYDROCARBON SPILLS INTO THE SUBSURFACE  

EPA Science Inventory

Hydrocarbons which enter the subsurface through spills or leaks may create serious, long-lived ground-water contamination problems. onventional finite difference and finite element models of multiphase, multicomponent flow often have extreme requirements for both computer time an...

13

Containment of subsurface contaminants  

DOEpatents

A barrier for reducing the spread of a plume of subsurface contaminants. The apparatus includes a well system for injecting a fluid, such as air, just outside and below the periphery of the plume. The fluid is injected at a pressure sufficient to lower the hydraulic conductivity of the soil from the point of injection to the surface thus establishing a curtain-like barrier to groundwater movement. The barrier is established upgradient of the plume to divert groundwater away, or preferably completely around the plume to reduce the flow of groundwater into or out of the plume. The barrier enables the remediation of the confined contamination and then, when the injection of the fluid is halted, the barrier quickly dissipates.

Corey, John C. (Aiken, SC)

1994-01-01

14

Understanding the fate of petroleum hydrocarbons in the subsurface environment  

SciTech Connect

To achieve effective remediation of subsurface petroleum hydrocarbon contamination, definite scientific and technical knowledge of their fate after they are spilled onto the ground surface or leaked from underground storage tanks is essential. The paper provides extensive details of the parameters that affect the fate of petroleum products in the underground environment. These include: the character of the subsurface environment; the composition, physical and chemical properties of petroleum products; and the mechanisms of their mobilization, immobilization and transformation in the subsurface. Data on the physical and chemical properties of soil, groundwater and petroleum hydrocarbons are identified. The mechanisms that affect the fate of these contaminants in the subsurface include vaporization and condensation, diffusion, advection, dispersion, dissolution, adsorption, biodegradation, and abiotic reactions. The relation between these mechanisms and the properties of soil, groundwater and petroleum hydrocarbons is described. The distribution of the contaminated petroleum products in the subsurface as affected by these parameters and principles is also described.

Chen, C.T.

1992-01-01

15

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

PubMed

In order to characterize the effect of vegetation on performance of constructed wetlands (CWs) treating low and high chlorinated hydrocarbon, two pilot-scale horizontal subsurface flow (HSSF) CWs (planted with Phragmites australis and unplanted) treating sulphate rich groundwater contaminated with MCB (monochlorobenzene, as a low chlorinated hydrocarbon), (about 10 mg L(-1)), and PCE (perchloroethylene, as a high chlorinated hydrocarbon), (about 2 mg L(-1)), were examined. With mean MCB inflow load of 299 mg m(-2) d(-1), the removal rate was 58 and 208 mg m(-2) d(-1) in the unplanted and planted wetland, respectively, after 4 m from the inlet. PCE was almost completely removed in both wetlands with mean inflow load of 49 mg m(-2) d(-1). However, toxic metabolites cis-1,2-DCE (dichloroethene) and VC (vinyl chloride) accumulated in the unplanted wetland; up to 70% and 25% of PCE was dechlorinated to cis-1,2-DCE and VC after 4 m from the inlet, respectively. Because of high sulphate concentration (around 850 mg L(-1)) in the groundwater, the plant derived organic carbon caused sulphide formation (up to 15 mg L(-1)) in the planted wetland, which impaired the MCB removal but not statistically significant. The results showed significant enhancement of vegetation on the removal of the low chlorinated hydrocarbon MCB, which is probably due to the fact that aerobic MCB degraders are benefited from the oxygen released by plant roots. Vegetation also stimulated completely dechlorination of PCE due to plant derived organic carbon, which is potentially to provide electron donor for dechlorination process. The plant derived organic carbon also stimulated dissimilatory sulphate reduction, which subsequently have negative effect on MCB removal. PMID:22832338

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

2012-07-23

16

Dual aquafer electrical heating of subsurface hydrocarbons  

Microsoft Academic Search

A method is described of electrically heating a viscous hydrocarbon-bearing subsurface formation which consists of: a. applying an electric voltage to a first electrode well extending into a subsurface first aquifer. The first aquifer contains flowable mobile water and having sufficiently high permeability to permit water to be flowed into and out of the first aquifer. The first aquifer extends

Segalman

1986-01-01

17

Dual aquafer electrical heating of subsurface hydrocarbons  

SciTech Connect

A method is described of electrically heating a viscous hydrocarbon-bearing subsurface formation which consists of: a. applying an electric voltage to a first electrode well extending into a subsurface first aquifer. The first aquifer contains flowable mobile water and having sufficiently high permeability to permit water to be flowed into and out of the first aquifer. The first aquifer extends laterally more than 100 feet from the first electrode well in at least one direction and overlaying the viscous hydrocarbon-bearing subsurface formation; b. applying an electric voltage to a second electrode well extending into a subsurface second aquifer, the second aquifer containing flowable mobile water and having sufficiently high permeability to permit water to be flowed into and out of the second aquifer, the second aquifer extending laterally more than 100 feet from the second electrode well in at least one direction and underlaying the viscous hydrocarbon-bearing subsurface formation; and c. causing electric current to flow between the first and second electrode wells and through the viscous hydrocarbon subsurface formation.

Segalman, D.J.

1986-09-23

18

Modeling subsurface contamination at Fernald  

SciTech Connect

The Department of Energy`s Fernald site is located about 20 miles northwest of Cincinnati. Fernald produced refined uranium metal products from ores between 1953 and 1989. The pure uranium was sent to other DOE sites in South Carolina, Tennessee, Colorado,and Washington in support of the nation`s strategic defense programs. Over the years of large-scale uranium production, contamination of the site`s soil and groundwater occurred.The contamination is of particular concern because the Fernald site is located over the Great Miami Aquifer, a designated sole-source drinking water aquifer. Contamination of the aquifer with uranium was found beneath the site, and migration of the contamination had occurred well beyond the site`s southern boundary. As a result, Fernald was placed on the National Priorities (CERCLA/Superfund) List in 1989. Uranium production at the site ended in 1989,and Fernald`s mission has been changed to one of environmental restoration. This paper presents information about computerized modeling of subsurface contamination used for the environmental restoration project at Fernald.

Jones, B.W.; Flinn, J.C.; Ruwe, P.R.

1994-09-13

19

A bioenhancement process for rapid remediation of multiphase subsurface contamination  

SciTech Connect

The presence of petroleum hydrocarbons, distillates, and chlorinated solvents in subsurface environments frequently occurs from inadvertent discharges or unlawful release, and can pose a serious threat to human health and the environment. Due to strict environmental regulations, many industries are faced with significant financial and, potentially, criminal penalties associated with releases of these chemicals. In recent years, responsible industries have intensified efforts to remediate subsurface contamination. However, the excessive cost and lack of timely success of traditional remedial options have diminished many industries' willingness to proactively engage in necessary cleanup efforts because the expense of doing so may be prohibitive to the sustained economic health of the industry. A new technology that addresses each aspect of subsurface contamination by volatile organic compounds (VOCs) has been developed to minimize the duration and cost of remedial efforts. The Subsurface Voltilization and Ventilation System[sup [trademark

Mayotte, T.J. (Brown Root Environmental, Holt, MI (United States))

1994-08-01

20

Subsurface Contaminants Focus Area annual report 1997  

SciTech Connect

In support of its vision for technological excellence, the Subsurface Contaminants Focus Area (SCFA) has identified three strategic goals. The three goals of the SCFA are: Contain and/or stabilize contamination sources that pose an imminent threat to surface and ground waters; Delineate DNAPL contamination in the subsurface and remediate DNAPL-contaminated soils and ground water; and Remove a full range of metal and radionuclide contamination in soils and ground water. To meet the challenges of remediating subsurface contaminants in soils and ground water, SCFA funded more than 40 technologies in fiscal year 1997. These technologies are grouped according to the following product lines: Dense Nonaqueous-Phase Liquids; Metals and Radionuclides; Source Term Containment; and Source Term Remediation. This report briefly describes the SCFA 1997 technologies and showcases a few key technologies in each product line.

NONE

1997-12-31

21

Apparatus for passive removal of subsurface contaminants  

DOEpatents

An apparatus is provided which passively removes contaminated gases from a subsurface. The apparatus includes a riser pipe extending into a subsurface which has an exterior end in fluid communication with a valve. When well pressure is greater than atmospheric pressure, the valve opens to release contaminants into the atmosphere, and when well pressure is less than atmospheric pressure, the valve closes to prevent flow of air into the well. The valve assembly of the invention comprises a lightweight ball which is lifted from its valve seat with a slight pressure drop between the well and the atmosphere. 7 figs.

Pemberton, B.E.; May, C.P.; Rossabi, J.

1997-06-24

22

Clean up hydrocarbon contamination effectively  

SciTech Connect

Hydrocarbon contamination of soil and groundwater is a serious health and environmental issue. Typical contamination sites include manufacturing plants, petroleum refineries, fuel and chemical storage facilities, gasoline service stations, and vehicle depots. Effective remediation of a site contaminated with hydrocarbons requires a sound understanding of regulatory issues, technology options, and the site's hydrogeology. Many treatment options exist, but none is a panacea. The optimal solution for a site is based on a thorough site-specific characterization, followed by a feasibility study that evaluates treatment alternatives. The outcome will be a cost-effective solution that combines treatment alternatives best suited to the site. This article outlines the technologies available for soil and groundwater remediation and how to select an appropriate technology from among them. The paper begins with a discussion on regulatory considerations, dealing with light non-aqueous phase liquids, remediating groundwater, and remediating soils before discussing the following technologies: soil washing, air stripping, carbon adsorption, soil vapor extraction, saturated zone bioremediation, unsaturated zone bioremediation, catalytic combustion, incineration, thermal desorption, in situ chemical oxidation, and UV-enhanced oxidation.

Long, G.M.

1993-05-01

23

In situ respirometry: Field methods and implications for hydrocarbon biodegradation in subsurface soils  

SciTech Connect

Using soil ventilation to promote in situ biodegradation is a promising technology for remediation of unsaturated, hydrocarbon-contaminated, subsurface soils. Evaluating in situ hydrocarbon biodegradation rates and levels is a critical part of this approach and determining changes in subsurface O{sub 2} and/or CO{sub 2} levels is a convenient method for monitoring this process because repetitive, noninvasive measurements can be made. In this study, two rapid field procedures for gas analysis, using either liquid- or solid-phase absorption of O{sub 2} and CO{sub 2}, were compared and the implications of these gas measurements for evaluating in situ hydrocarbon biodegradation considered. Air samples were taken from 5 vadose zone piezometers in a gasoline-contaminated soil under treatment by a soil vapor extraction system and one piezometer in a noncontaminated background area. Similar rates and levels of O{sub 2} consumption and CO{sub 2} production were obtained by both techniques during the 20-d study: thus, the method of choice will depend on factors such as cost, air sample volume limitations, or the need for contaminant vapor analyses in the field. While these techniques were good assays for relative microbial activity levels, significant descrepancies between predicted and measured CO{sub 2} levels raised questions concerning the validity of basing hydrocarbon biodegradation estimates solely in O{sub 2} consumption data. To improve the reliability of in situ fuel biodegradation estimates based on O{sub 2} measurements, the relationship(s) between metabolic activities of microbial populations in hydrocarbon-contaminated soils, and changes in subsurface O{sub 2} and CO{sub 2} levels should be clarified. 14 refs., 3 figs., 3 tabs.

Hickey, W.J. [Univ. of Wisconsin, Madison, WI (United States)

1995-07-01

24

Anaerobic hydrocarbon biodegradation in deep subsurface oil reservoirs.  

PubMed

Biodegradation of crude oil in subsurface petroleum reservoirs is an important alteration process with major economic consequences. Aerobic degradation of petroleum hydrocarbons at the surface is well documented and it has long been thought that the flow of oxygen- and nutrient-bearing meteoric waters into reservoirs was necessary for in-reservoir petroleum biodegradation. The occurrence of biodegraded oils in reservoirs where aerobic conditions are unlikely, together with the identification of several anaerobic microorganisms in oil fields and the discovery of anaerobic hydrocarbon biodegradation mechanisms, suggests that anaerobic degradation processes could also be responsible. The extent of anaerobic hydrocarbon degradation processes in the world's deep petroleum reservoirs, however, remains strongly contested. Moreover, no organism has yet been isolated that has been shown to degrade hydrocarbons under the conditions found in deep petroleum reservoirs. Here we report the isolation of metabolites indicative of anaerobic hydrocarbon degradation from a large fraction of 77 degraded oil samples from both marine and lacustrine sources from around the world, including the volumetrically important Canadian tar sands. Our results therefore suggest that anaerobic hydrocarbon degradation is a common process in biodegraded subsurface oil reservoirs. PMID:15372028

Aitken, Carolyn M; Jones, D M; Larter, S R

2004-09-16

25

Chemical contaminants on DOE lands and selection of contaminant mixtures for subsurface science research  

SciTech Connect

This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE's Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research on important mixed contaminants that are likely to be long-term problems at DOE sites and that will require cleanup or remediation. The report provides information on the frequency of associations among different chemicals and compound classes at DOE waste sites that require remediation.

Riley, R.G.; Zachara, J.M. (Pacific Northwest Lab., Richland, WA (United States))

1992-04-01

26

Microbiological indicators of subsurface hydrocarbon accumulations  

SciTech Connect

The measurement of toxin tolerance in the microbial communities present in stream sediments has been demonstrated to be an effective exploration tool. The technique relies on the fact that metals of, or associated with, ore deposits often represent toxins to microbial communities. The microbes adapt to the presence of these toxins by genetic mutation of replicon structures called plasmids that then carry the coding that allows survival in their presence. The level of tolerance developed is proportional to the concentration of toxin present and shows measurable, statistically meaningful variance at levels normally below the detection thresholds of standard inorganic techniques. Hydrocarbons reaching the surface by macro- and microseepage, the metals adsorbed to them, and the geochemical changes they bring about in the near-surface environment also represent toxins or stresses to microbial communities that they must adapt to. Adaptation is again accomplished by genetic mutation and is measured by collecting a sediment sample, separating the microbial population from it, and exposing splits of the sample to several discrete concentrations of the hydrocarbon or metal being used as a seepage indicator. Tolerance to higher levels of toxin is interpreted to be indicative of the strength or volume of hydrocarbon seepage. The authors have undertaken this work using marine samples from the Gulf of Mexico because that setting has fewer surface geochemical variables than subaerial settings. Both gas and oil accumulations can be measured by this technique, and evidence for both macro- and microseepage has been found. Examples from the Mississippi Canyon area will be used to illustrate the efficacy of the technique.

Riese, W.C. (ARCO Oil and Gas Co., Bakersfield, CA (United States)); Michaels, G.B. (Western State College, Gunnison, CO (United States))

1991-03-01

27

MAPPING OF SUBSURFACE CONTAMINANT PROFILES BY NEURAL NETWORKS  

Microsoft Academic Search

Determining the extent of contamination is a frequently encountered problem for private industry and governmental agencies. Numerous groundwater contaminant transport models have been developed involving mathematical relationships based on an understanding of the physical, chemical and microbiological processes that are thought to affect transport of contaminants in subsurface environments. This paper presents the application of neural networks for groundwater contaminant

CLAIRE JORDAHL Project Engineer

1999-01-01

28

Bioremediation of hydrocarbon-contaminated polar soils  

Microsoft Academic Search

Bioremediation is increasingly viewed as an appropriate remediation technology for hydrocarbon-contaminated polar soils. As for all soils, the successful application of bioremediation depends on appropriate biodegradative microbes and environmental conditions in situ. Laboratory studies have confirmed that hydrocarbon-degrading bacteria typically assigned to the genera Rhodococcus, Sphingomonas or Pseudomonas are present in contaminated polar soils. However, as indicated by the persistence

Jackie Aislabie; David J. Saul; Julia M. Foght

2006-01-01

29

Methanogenic degradation of petroleum hydrocarbons in subsurface environments remediation, heavy oil formation, and energy recovery.  

PubMed

Hydrocarbons are common constituents of surface, shallow, and deep-subsurface environments. Under anaerobic conditions, hydrocarbons can be degraded to methane by methanogenic microbial consortia. This degradation process is widespread in the geosphere. In comparison with other anaerobic processes, methanogenic hydrocarbon degradation is more sustainable over geological time scales because replenishment of an exogenous electron acceptor is not required. As a consequence, this process has been responsible for the formation of the world's vast deposits of heavy oil, which far exceed conventional oil assets such as those found in the Middle East. Methanogenic degradation is also a potentially important component of attenuation in hydrocarbon contamination plumes. Studies of the organisms, syntrophic partnerships, mechanisms, and geochemical signatures associated with methanogenic hydrocarbon degradation have identified common themes and diagnostic markers for this process in the subsurface. These studies have also identified the potential to engineer methanogenic processes to enhance the recovery of energy assets as biogenic methane from residual oils stranded in petroleum systems. PMID:20602990

Gray, N D; Sherry, A; Hubert, C; Dolfing, J; Head, I M

2010-01-01

30

Bioventing soils contaminated with petroleum hydrocarbons  

Microsoft Academic Search

Summary Bioventing combines the capabilities of soil venting and enhanced bioremediation to cost-effectively remove light and middle distillate hydrocarbons from vadose zone soils and the groundwater table. Soil venting removes the more volatile fuel components from unsaturated soil and promotes aerobic biodegradation by driving large volumes of air into the subsurface. In theory, air is several thousand times more effective

Ronald E. Hoeppel; Robert E. Hinchee; Mick F. Arthur

1991-01-01

31

Bioremediation of Petroleum Hydrocarbon Contaminated Sites.  

National Technical Information Service (NTIS)

Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and ty...

P. Fallgren

2009-01-01

32

Effects of Subsurface Microbial Ecology on Geochemical Evolution of a Crude-Oil Contaminated Aquifer  

NASA Astrophysics Data System (ADS)

We have identified several subsurface habitats for microorganisms in a crude oil contaminated located near Bemidji, Minnesota. These aquifer habitats include: 1) the unsaturated zone contaminated by hydrocarbon vapors, 2) the zones containing separate-phase crude oil, and 3) the aqueous-phase contaminant plume. The surficial glacial outwash aquifer was contaminated when a crude oil pipeline burst in 1979. We analyzed sediment samples from the contaminated aquifer for the most probable numbers of aerobes, iron reducers, fermenters, and three types of methanogens. The microbial data were then related to gas, water, and oil chemistry, sediment extractable iron, and permeability. The microbial populations in the various contaminated subsurface habitats each have special characteristics and these affect the aquifer and contaminant chemistry. In the eight-meter-thick, vapor-contaminated vadose zone, a substantial aerobic population has developed that is supported by hydrocarbon vapors and methane. Microbial numbers peak in locations where access to both hydrocarbons and nutrients infiltrating from the surface is maximized. The activity of this population prevents hydrocarbon vapors from reaching the land surface. In the zone where separate-phase crude oil is present, a consortium of methanogens and fermenters dominates the populations both above and below the water table. Moreover, gas concentration data indicate that methane production has been active in the oily zone since at least 1986. Analyses of the extracted separate-phase oil show that substantial degradation of C15 -C35 n-alkanes has occurred since 1983, raising the possibility that significant degradation of C15 and higher n-alkanes has occurred under methanogenic conditions. However, lab and field data suggest that toxic inhibition by crude oil results in fewer acetate-utilizing methanogens within and adjacent to the separate-phase oil. Data from this and other sites indicate that toxic inhibition of acetoclastic methanogenesis in the proximity of separate phase contaminant sources may result in build-up of acetate in contaminant plumes. Within the aqueous-phase contaminant plume steep vertical hydrocarbon concentration gradients are associated with sharp transitions in the dominant microbial population. In the 20 years since the aquifer became contaminated, sediment iron oxides have been depleted and the dominant physiologic type has changed in areas of high contaminant flux from iron reducing to methanogenic. Thus, methanogens are found in high permeability horizons down gradient from the oil while iron reducers persist in low permeability zones. Expansion of the methanogenic zone over time has resulted in a concomitant increase in the aquifer volume contaminated with the highest concentrations of benzene and ethylbenzene.

Bekins, B. A.; Cozzarelli, I. M.; Godsy, E. M.; Warren, E.; Hostettler, F. D.

2001-12-01

33

IMPACT OF REDOX DISEQUILIBRIA ON CONTAMINANT TRANSPORT AND REMEDIATION IN SUBSURFACE SYSTEMS  

EPA Science Inventory

Partitioning to mineral surfaces exerts significant control on inorganic contaminant transport in subsurface systems. Remedial technologies for in-situ treatment of subsurface contamination are frequently designed to optimize the efficiency of contaminant partitioning to solid s...

34

Subsurface Contamination Focus Area technical requirements. Volume 1: Requirements summary  

SciTech Connect

This document summarizes functions and requirements for remediation of source term and plume sites identified by the Subsurface Contamination Focus Area. Included are detailed requirements and supporting information for source term and plume containment, stabilization, retrieval, and selective retrieval remedial activities. This information will be useful both to the decision-makers within the Subsurface Contamination Focus Area (SCFA) and to the technology providers who are developing and demonstrating technologies and systems. Requirements are often expressed as graphs or charts, which reflect the site-specific nature of the functions that must be performed. Many of the tradeoff studies associated with cost savings are identified in the text.

Nickelson, D.; Nonte, J.; Richardson, J.

1996-10-01

35

ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS  

EPA Science Inventory

An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

36

MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE: APPLICATIONS  

EPA Science Inventory

In recent years there has been increasing interest in the application of passive technologies to reduce or remove contaminants from the subsurface environment including soil and ground water. In most cases, the impetus for this interest lies in a perceived savings compared with...

37

IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS  

EPA Science Inventory

An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. nderstanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of the...

38

The Stimulation of Hydrocarbon Reservoirs with Subsurface Nuclear Explosions  

SciTech Connect

Between 1965 and 1979 there were five documented and one or more inferred attempts to stimulate the production from hydrocarbon reservoirs by detonating nuclear devices in reservoir strata. Of the five documented tests, three were carried out by the US in low-permeability, natural-gas bearing, sandstone-shale formations, and two were done in the USSR within oil-bearing carbonates. The objectives of the US stimulation efforts were to increase porosity and permeability in a reservoir around a specific well by creating a chimney of rock rubble with fractures extending beyond it, and to connect superimposed reservoir layers. In the USSR, the intent was to extensively fracture an existing reservoir in the more general vicinity of producing wells, again increasing overall permeability and porosity. In both countries, the ultimate goals were to increase production rates and ultimate recovery from the reservoirs. Subsurface explosive devices ranging from 2.3 to about 100 kilotons were used at depths ranging from 1208 m (3963 ft) to 2568 m (8427 ft). Post-shot problems were encountered, including smaller-than-calculated fracture zones, formation damage, radioactivity of the product, and dilution of the BTU value of tie natural gas with inflammable gases created by the explosion. Reports also suggest that production-enhancement factors from these tests fell short of expectations. Ultimately, the enhanced-production benefits of the tests were insufficient to support continuation of the pro-grams within increasingly adversarial political, economic, and social climates, and attempts to stimulate hydrocarbon reservoirs with nuclear devices have been terminated in both countries.

LORENZ,JOHN C.

2000-12-08

39

Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel  

SciTech Connect

Fuel hydrocarbons are known to be readily biodegraded and protozoa may be associated with this process. The objective of this study is to determine whether protozoa are numerous enough in the contaminated areas of the subsurface to play a significant role in the microbial community. The results indicate that protozoa can become very numerous in the subsurface at fuel-contaminated sites with the greatest abundance of protozoa in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and slightly beneath the floating fuel on the water table. In contrast, bacteria seemed to adapt to local conditions and showed less change in numbers in different parts of the profile than protozoa. Bioremediation of subsurface sediments is dependent on a sufficient hydraulic conductivity to permit pumping nutrients through the affected area. Bacteria have been known to cause large reductions in hydraulic conductivity. At the study area this reduction was not noted in spite of large concentrations of bacteria. The authors conclude that this may indicate a role for protozoa in maintaining hydraulic conductivity during biotreatment of readily degraded organic contaminants.

Sinclair, J.L.; Kampbell, D.H.; Cook, M.L.; Wilson, J.T. (Robert S. Kerr Environmental Research Lab., Ada, OK (United States))

1993-02-01

40

Physical and chemical factors affecting microbial biomass and activity in contaminated subsurface riverine sediments.  

PubMed

Over 80 years of direct discharge of industrial effluents into the Mahoning River, located in northeastern Ohio, USA, has led to the accumulation of a wide variety of pollutants within its sediments. This study examined the physical and chemical parameters, including lipophilic pollutants, affecting microbial activity and biomass in subsurface (10-40 cm horizon) sediments. Microbial biomass was higher in anthropogenically contaminated sediments, and step-wise linear regression showed that approximately 82% of the variation in microbial biomass could be explained by total hexane extractable hydrocarbons, sediment particle size, and water content. There was no correlation between microbial activity and biomass. Independent variables influencing anaerobic activity were temperature and water holding capacity. The results of this study indicate that freshwater, sedimentary anaerobic microbial communities respond to a range of environmental parameters, many of which influence subsurface river sediments, and that lipophilic pollutants, when present, can cause increases in total microbial biomass. PMID:16699563

Mosher, Jennifer J; Findlay, Robert H; Johnston, Carl G

2006-05-01

41

Subsurface sediment contamination during borehole drilling with an air-actuated down-hole hammer.  

PubMed

Drilling methods can severely alter physical, chemical, and biological properties of aquifers, thereby influencing the reliability of water samples collected from groundwater monitoring wells. Because of their fast drilling rate, air-actuated hammers are increasingly used for the installation of groundwater monitoring wells in unconsolidated sediments. However, oil entrained in the air stream to lubricate the hammer-actuating device can contaminate subsurface sediments. Concentrations of total hydrocarbons, heavy metals (Cu, Ni, Cr, Zn, Pb, and Cd), and nutrients (particulate organic carbon, nitrogen, and phosphorus) were measured in continuous sediment cores recovered during the completion of a 26-m deep borehole drilled with a down-hole hammer in glaciofluvial deposits. Total hydrocarbons, Cu, Ni, Cr and particulate organic carbon (POC) were all measured at concentrations far exceeding background levels in most sediment cores. Hydrocarbon concentration averaged 124 +/- 118 mg kg(-1) dry sediment (n = 78 samples) with peaks at depths of 8, 14, and 20 m below the soil surface (maximum concentration: 606 mg kg(-1)). The concentrations of hydrocarbons, Cu, Ni, Cr, and POC were positively correlated and exhibited a highly irregular vertical pattern, that probably reflected variations in air loss within glaciofluvial deposits during drilling. Because the penetration of contaminated air into the formation is unpreventable, the representativeness of groundwater samples collected may be questioned. It is concluded that air percussion drilling has strong limitations for well installation in groundwater quality monitoring surveys. PMID:16091299

Malard, Florian; Datry, Thibault; Gibert, Janine

2005-08-08

42

Subsurface sediment contamination during borehole drilling with an air-actuated down-hole hammer  

NASA Astrophysics Data System (ADS)

Drilling methods can severely alter physical, chemical, and biological properties of aquifers, thereby influencing the reliability of water samples collected from groundwater monitoring wells. Because of their fast drilling rate, air-actuated hammers are increasingly used for the installation of groundwater monitoring wells in unconsolidated sediments. However, oil entrained in the air stream to lubricate the hammer-actuating device can contaminate subsurface sediments. Concentrations of total hydrocarbons, heavy metals (Cu, Ni, Cr, Zn, Pb, and Cd), and nutrients (particulate organic carbon, nitrogen, and phosphorus) were measured in continuous sediment cores recovered during the completion of a 26-m deep borehole drilled with a down-hole hammer in glaciofluvial deposits. Total hydrocarbons, Cu, Ni, Cr and particulate organic carbon (POC) were all measured at concentrations far exceeding background levels in most sediment cores. Hydrocarbon concentration averaged 124 ± 118 mg kg- 1 dry sediment (n = 78 samples) with peaks at depths of 8, 14, and 20 m below the soil surface (maximum concentration: 606 mg kg- 1). The concentrations of hydrocarbons, Cu, Ni, Cr, and POC were positively correlated and exhibited a highly irregular vertical pattern, that probably reflected variations in air loss within glaciofluvial deposits during drilling. Because the penetration of contaminated air into the formation is unpreventable, the representativeness of groundwater samples collected may be questioned. It is concluded that air percussion drilling has strong limitations for well installation in groundwater quality monitoring surveys.

Malard, Florian; Datry, Thibault; Gibert, Janine

2005-10-01

43

Subsurface Flow and Contaminant Transport Documentation and User's Guide  

SciTech Connect

This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogeneous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally, 1-D and 2-D (in Cartesian coordinates) problems are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates.

Aleman, S.E.

1999-07-28

44

Contaminant Transport Through Subsurface Material from the DOE Hanford Reservation  

SciTech Connect

Accelerated migration of contaminants in the vadose zone has been observed beneath tank farms at the U.S. Department of Energy's Hanford Reservation. This paper focuses on the geochemical processes controlling the fate and transport of contaminants in the sediments beneath the Hanford tank farms. Laboratory scale batch sorption experiments and saturated transport experiments were conducted using reactive tracers U(VI), Sr, Cs, Co and Cr(VI) to investigate geochemical processes controlling the rates and mechanisms of sorption to Hanford subsurface material. Results indicate that the rate of sorption is influenced by changes in solution chemistry such as ionic strength, pH and presence of competing cations. Sediment characteristics such as mineralogy, iron content and cation/anion exchange capacity coupled with the dynamics of flow impact the number of sites available for sorption. Investigative approaches using a combination of batch and transport experiments will contribute to the conceptual and Hanford vadose zone.

Pace, M.N.; Mayes, M.A.; Jardine, P.M.; Fendorf, S.E.; Nehlhorn, T.L.; Yin, X.P.; Ladd, J.; Teerlink, J.; Zachara, J.M.

2003-03-26

45

Modeling subsurface contaminant reactions and transport at the watershed scale  

SciTech Connect

The objectives of this research are: (1) to numerically examine the multiscale effects of physical and chemical mass transfer processes on watershed scale, variably saturated subsurface contaminant transport, and (2) to conduct numerical simulations on watershed scale reactive solute transport and evaluate their implications to uncertainty characterization and cost benefit analysis. Concurrent physical and chemical nonequilibrium caused by inter aggregate gradients of pressure head and solute concentration and intra-aggregate geochemical and microbiological processes, respectively, may arise at various scales and flowpaths. To this date, experimental investigations of these complex processes at watershed scale remain a challenge and numerical studies are often needed for guidance of water resources management and decision making. This research integrates the knowledge bases developed during previous experimental and numerical investigations at a proposed waste disposal site at the Oak Ridge National Laboratory to study the concurrent effects of physical and chemical nonequilibrium. Comparison of numerical results with field data indicates that: (1) multiregion, preferential flow and solute transport exist under partially saturated condition and can be confirmed theoretically, and that (2) mass transfer between pore regions is an important process influencing contaminant movement in the subsurface. Simulations of watershed scale, multi species reactive solute transport suggest that dominance of geochemistry and hydrodynamics may occur simultaneously at different locales and influence the movement of one species relative to another. Execution times on the simulations of the reactive solute transport model also indicate that the model is ready to assist the selection of important parameters for site characterization.

Gwo, J.P.; Jardine, P.M.; D`Azevedo, E.F. [Oak Ridge National Lab., TN (United States); Wilson, G.V. [Desert Research Inst., Las Vegas, NV (United States). Water Resources Center

1997-12-01

46

Kinetics of Degradation of Hydrocarbons in the Contaminated Soil Layer  

Microsoft Academic Search

This work presents kinetic parameters of the removal of hydrocarbons in the course of bioremediation of the soil contaminated with crude and oil derivatives, with special emphasis paid to polycyclic aromatic hydrocarbons. Bioremediation was carried out on a laboratory scale, with continuous and discontinuous recirculation of water through the soil column inoculated with the adapted bacterial population. Biodegradation of hydrocarbons

S. Roncevic ´; B. Dalmacija; I Ivan?ev-Tumbas; J Tri?kovi?; O Petrovi?; M Klašnja; J Agbaba

2005-01-01

47

Intrinsic bioremediation of petroleum hydrocarbons in a gas condensate-contaminated aquifer  

SciTech Connect

A study was designed to determine if the intrinsic bioremediation of gas condensate hydrocarbons represented an important fate process in a shallow aquifer underlying a natural gas production site. For over 4 yr, changes in the groundwater, sediment, and vadose zone chemistry in the contaminated portion of the aquifer were interpreted relative to a background zone. Changes included decreased dissolved oxygen and sulfate levels and increased alkalinity, Fe(II), and methane concentrations in the contaminated groundwater, suggesting that aerobic heterotrophic respiration depleted oxygen reserves leaving anaerobic conditions in the hydrocarbon-impacted subsurface. Dissolved hydrogen levels in the contaminated groundwater indicated that sulfate reduction and methanogenesis were predominant biological processes, corroborating the geochemical findings. Furthermore, 10--1000-fold higher numbers of sulfate reducers and methanogens were enumerated in the contaminated sediment relative to background. Putative metabolites were also detected in the contaminated groundwater, including methylbenzylsuccinic acid, a signature intermediate of anaerobic xylene decay. Laboratory incubations showed that benzene, toluene, ethylbenzene, and each of the xylene isomers were biodegraded under sulfate-reducing conditions as was toluene under methanogenic conditions. These results coupled with a decrease in hydrocarbon concentrations in contaminated sediment confirm that intrinsic bioremediation contributes to the attenuation of hydrocarbons in this aquifer.

Gieg, L.M.; McInerney; Tanner, R.S.; Harris, S.H. Jr.; Sublette, K.L.; Suflita, J.M. (Univ. of Oklahoma, Norman, OK (United States)); Kolhatkar, R.V. (Univ. of Tulsa, OK (United States). Center for Environmental Research and Technology)

1999-08-01

48

Microbial community structure in a shallow hydrocarbon-contaminated aquifer associated with high electrical conductivity  

NASA Astrophysics Data System (ADS)

Little is known about the complex interactions between microbial communities and electrical properties in contaminated aquifers. In order to investigate possible connections between these parameters a study was undertaken to investigate the hypothesis that the degradation of hydrocarbons by resident microbial communities causes a local increase in organic acid concentrations, which in turn cause an increase in native mineral weathering and a concurrent increase in the bulk electrical conductivity of soil. Microbial community structure was analyzed using a 96-well most probable number (MPN) method and rDNA intergenic spacer region analysis (RISA). Microbial community structure was found to change in the presence of hydrocarbon contaminants and these changes were consistently observed in regions of high electrical conductivity. We infer from this relationship that geophysical methods for monitoring the subsurface are a promising new technology for monitoring changes in microbial community structure and simultaneous changes in geochemistry that are associated with hydrocarbon degradation.

Duris, J. W.; Rossbach, S.; Atekwana, E. A.; Werkema, D., Jr.

2003-04-01

49

FIELD TRAPPING OF SUBSURFACE VAPOR PHASE PETROLEUM HYDROCARBONS  

EPA Science Inventory

Soil gas samples from intact soil cores were collected on adsorbents at a field site, then thermally desorbed and analyzed by laboratory gas chromatography (GC). ertical concentration profiles of predominant vapor phase petroleum hydrocarbons under ambient conditions were obtaine...

50

The stability and utility of diagnostic ratio hydrocarbon fingerprinting for soils contaminated with petroleum hydrocarbons  

Microsoft Academic Search

In order to recover costs for oil spill cleanup and restoration regulatory agencies and trustees of natural resources are interested in identifying parties responsible for hydrocarbon releases, and for associated environmental damages. Chemical analyses of contaminated soil and groundwater samples are currently used to identify the sources of contamination in soil and groundwater systems. However, conventional hydrocarbon fingerprinting approaches such

G. S. Douglas; Sara McMillen

1996-01-01

51

Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout  

Microsoft Academic Search

Hydrocarbons released following the Deepwater Horizon (DH) blowout were found in deep, subsurface horizontal intrusions, yet there has been little discussion about how these intrusions formed. We have combined measured (or estimated) observations from the DH release with empirical relationships developed from previous lab experiments to identify the mechanisms responsible for intrusion formation and to characterize the DH plume. Results

Scott A. Socolofsky; E. Eric Adams; Christopher R. Sherwood

2011-01-01

52

Potential for aerobic and anaerobic biodegradation of petroleum hydrocarbons in boreal subsurface.  

PubMed

We studied the role of aerobic and anaerobic petroleum hydrocarbon degradation at a boreal, light-weight fuel and lubrication oil contaminated site undergoing natural attenuation. At the site, anoxic conditions prevailed with high concentrations of CH4 (up to 25% v/v) and CO2 (up to 18% v/v) in the soil gas throughout the year. Subsurface samples were obtained mainly from the anoxic parts of the site and they represented both the unsaturated and saturated zone. The samples were incubated in microcosms at near in situ conditions (i.e. in situ temperature 8 degrees C, aerobic and anaerobic conditions, no nutrient amendments) resulting in the removal of mineral oil (as determined by gas chromatography) aerobically as well as anaerobically. In the aerobic microcosms on average 31% and 27% of the initial mineral oil was removed during a 3- and 4-month incubation, respectively. In the anaerobic microcosms, on average 44% and 15% of the initial mineral oil was removed during a 12- and 10-month anaerobic incubation, respectively, and e.g. n-alkanes from C11 to C15 were removed. A methane production rate of up to 2.5 microg CH4 h(-1) g(-1) dwt was recorded in these microcosms. In the aerobic as well as anaerobic microcosms, typically 90% of the mineral oil degraded belonged to the mineral oil fraction that eluted from the gas chromatograph after C10 and before C15, while 10% belonged to the fraction that eluted after C15 and before C40. Our results suggest that anaerobic petroleum hydrocarbon degradation, including n-alkane degradation, under methanogenic conditions plays a significant role in the natural attenuation in boreal conditions. PMID:14971855

Salminen, Jani M; Tuomi, Pirjo M; Suortti, Anna-Mari; Jørgensen, Kirsten S

2004-02-01

53

Polycyclic aromatic hydrocarbons in fuel-oil contaminated soils, Antarctica  

Microsoft Academic Search

Where fuel oil spills have occurred on Antarctic soils polycyclic aromatic hydrocarbons (PAH) may accumulate. Surface and subsurface soil samples were collected from fuel spill sites up to 30 years old, and from nearby control sites, and analysed for the 16 PAHs on the USEPA priority pollutants list, as well as for two methyl substituted naphthalenes, 1-methylnaphthalene and 2-methylnaphthalene. PAH

Jackie Aislabie; Megan Balks; Norma Astori; Gavin Stevenson; Robert Symons

1999-01-01

54

The abundance of nahAc genes correlates with the 14C-naphthalene mineralization potential in petroleum hydrocarbon-contaminated oxic soil layers  

Microsoft Academic Search

In this study, we evaluated whether the abundance of the functional gene nahAc reflects aerobic naphthalene degradation potential in subsurface and surface samples taken from three petroleum hydrocarbon contaminated sites in southern Finland. The type of the contamination at the sites varied from lightweight diesel oil to high molecular weight residuals of crude oil. Samples were collected from both oxic

Pirjo M. Tuomi; Jani M. Salminen; Kirsten S. Jørgensen

2004-01-01

55

Speciation of subsurface contaminants by cone penetrometry gas chromatography/mass spectrometry  

SciTech Connect

A thermal extraction cone penetrometry gas chromatography/mass spectrometry system (TECP GC/MS) has been developed to detect subsurface contaminants in situ. The TECP can collect soil-bound organics up to depths of 30 m. In contrast to traditional cone penetrometer sample collectors, the TECP extracts organics from soil without bringing the soil to the surface or into a collection chamber. Results show that polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), chlorinated pesticides, and explosives can be recovered (60--95%) from wet or dry soil, with extraction efficiency compound-specific. The data are in remarkable agreement with closed cell thermal desorption (TD) experiments, where no organics are lost to the environment during heating. ECP GC/MS results also compare favorably with solvent-extracted GC/MS analyses and can be used to delineate the presence and extent of contamination at hazardous waste sites. Data illustrating TECP dependence on probe temperature and soil moisture as well as carrier gas liner velocity and volume (modified Reynolds number) are shown along with sample analysis data from two hazardous waste sites. The total ion and reconstructed ion current chromatograms are shown for PAHs collected by TECP from a coal tar contaminated soil obtained at a manufactured gas plant in Massachusetts. TECP and TD results are within 15% for nonvolatile PAHs and within 50% of the solvent-extracted data.

Gorshteyn, A.; Smarason, S.; Robbat, A. Jr. (Tufts Univ., Medford, MA (United States))

1999-07-15

56

Fate and transport of petroleum hydrocarbons in the subsurface near Cass Lake, Minnesota  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) investigated the natural attenuation of subsurface petroleum hydrocarbons leaked over an unknown number of years from an oil pipeline under the Enbridge Energy Limited Partnership South Cass Lake Pumping Station, in Cass Lake, Minnesota. Three weeks of field work conducted between May 2007 and July 2008 delineated a dissolved plume of aromatic hydrocarbons and characterized the biodegradation processes of the petroleum. Field activities included installing monitoring wells, collecting sediment cores, sampling water from wells, and measuring water-table elevations. Geochemical measurements included concentrations of constituents in both spilled and pipeline oil, dissolved alkylbenzenes and redox constituents, sediment bioavailable iron, and aquifer microbial populations. Groundwater in this area flows east-southeast at approximately 26 meters per year. Results from the oil analyses indicate a high degree of biodegradation, characterized by nearly complete absence of n-alkanes. Cass Lake oil samples were more degraded than two oil samples collected in 2008 from the similarly contaminated USGS Bemidji, Minnesota, research site 40 kilometers away. Based on 19 ratios developed for comparing oil sources, the conclusion is that the oils at the two sites appear to be from the same hydrocarbon source. In the Cass Lake groundwater plume, benzene concentrations decrease by three orders of magnitude within 150 meters (m) downgradient from the oil body floating on the water table (between well MW-10 and USGS-4 well nest). The depths of the highest benzene concentrations increase with distance downgradient from the oil, a condition typical of plumes in shallow, unconfined aquifers. Background groundwater, which is nearly saturated with oxygen, becomes almost entirely anaerobic in the plume. As at the Bemidji site, the most important biodegradation processes are anaerobic and dominated by iron reduction. The similarity between the Cass Lake and Bemidji benzene degradation rates, redox conditions, and aquifer material all support a hypothesis that the Cass Lake plume, like the Bemidji plume, is decades old. As concentrations of alkylbenzenes in the oil decrease over time, the benzene concentrations in the groundwater plume will also decrease and the plume is expected to shrink. The Fox Creek wetland, about 250 m south of the Cass Lake site, is the nearest receptor to the south.

Drennan, Dina M.; Bekins, Barbara A.; Warren, Ean; Cozzarelli, Isabelle M.; Baedecker, Mary Jo; Herkelrath, William N.; Delin, Geoffrey N.; Rosenbauer, Robert J.; Campbell, Pamela L.

2010-01-01

57

Reactive Membrane Barriers for Containment of Subsurface Contamination  

SciTech Connect

The overall goal of this project was to develop reactive membrane barriers--a new and flexible technique to contain and stabilize subsurface contaminants. Polymer membranes will leak once a contaminant is able to diffuse through the membrane. By incorporating a reactive material in the polymer, however, the contaminant is degraded or immobilized within the membrane. These processes increase the time for contaminants to breakthrough the barrier (i.e. the lag time) and can dramatically extend barrier lifetimes. In this work, reactive barrier membranes containing zero-valent iron (Fe{sup 0}) or crystalline silicotitanate (CST) were developed to prevent the migration of chlorinated solvents and cesium-137, respectively. These studies were complemented by the development of models quantifying the leakage/kill time of reactive membranes and describing the behavior of products produced via the reactions within the membranes. First, poly(vinyl alcohol) (PVA) membranes containing Fe{sup 0} and CST were prepared and tested. Although PVA is not useful in practical applications, it allows experiments to be performed rapidly and the results to be compared to theory. For copper ions (Cu{sup 2+}) and carbon tetrachloride, the barrier was effective, increasing the time to breakthrough over 300 times. Even better performance was expected, and the percentage of the iron used in the reaction with the contaminants was determined. For cesium, the CST laden membranes increased lag times more than 30 times, and performed better than theoretical predictions. A modified theory was developed for ion exchangers in reactive membranes to explain this result. With the PVA membranes, the effect of a groundwater matrix on barrier performance was tested. Using Hanford groundwater, the performance of Fe{sup 0} barriers decreased compared to solutions containing a pH buffer and high levels of chloride (both of which promote iron reactivity). For the CST bearing membrane, performance improved by a factor of three when groundwater was used in place of deionized water. The performance of high density polyethylene (HDPE) membranes containing Fe{sup 0} was then evaluating using carbon tetrachloride as the target contaminant. Only with a hydrophilic additive (glycerol), was the iron able to extend lag times. Lag times were increased by a factor of 15, but only 2-3% of the iron was used, likely due to formation of oxide precipitates on the iron surface, which slowed the reaction. With thicker membranes and lower carbon tetrachloride concentrations, it is expected that performance will improve. Previous models for reactive membranes were also extended. The lag time is a measurement of when the barrier is breached, but contaminants do slowly leak through prior to the lag time. Thus, two parameters, the leakage and the kill time, were developed to determine when a certain amount of pollutant has escaped (the kill time) or when a given exposure (concentration x time) occurs (the leakage). Finally, a model was developed to explain the behavior of mobile reaction products in reactive barrier membranes. Although the goal of the technology is to avoid such products, it is important to be able to predict how these products will behave. Interestingly, calculations show that for any mobile reaction products, one half of the mass will diffuse into the containment area and one half will escape, assuming that the volumes of the containment area and the surrounding environment are much larger than the barrier membrane. These parameters/models will aid in the effective design of barrier membranes.

William A. Arnold; Edward L. Cussler

2007-02-26

58

Subsurface contamination focus area technical requirements. Volume II  

SciTech Connect

This is our vision, a vision that replaces the ad hoc or {open_quotes}delphi{close_quotes} method which is to get a group of {open_quotes}experts{close_quotes} together and make decisions based upon opinion. To fulfill our vision for the Subsurface Contaminants Focus Area (SCFA), it is necessary to generate technical requirements or performance measures which are quantitative or measurable. Decisions can be supported if they are based upon requirements or performance measures which can be traced to the origin (documented) and are verifiable, i.e., prove that requirements are satisfied by inspection (show me), demonstration, analysis, monitoring, or test. The data from which these requirements are derived must also reflect the characteristics of individual landfills or plumes so that technologies that meet these requirements will necessarily work at specific sites. Other subjective factors, such as stakeholder concerns, do influence decisions. Using the requirements as a basic approach, the SCFA can depend upon objective criteria to help influence the areas of subjectivity, like the stakeholders. In the past, traceable requirements were not generated, probably because it seemed too difficult to do so. There are risks that the requirements approach will not be accepted because it is new and represents a departure from the historical paradigm.

Nickelson, D.; Nonte, J.; Richardson, J.

1996-10-01

59

The microbiology of hydrocarbon degradation in subsurface petroleum reservoirs: perspectives and prospects.  

PubMed

The majority of the Earth's petroleum resource is partly biodegraded. This is of considerable practical significance and can limit economic exploitation of petroleum reserves and lead to problems during petroleum production. Knowledge of the microorganisms present in petroleum reservoirs, their physiological properties and the biochemical potential for hydrocarbon degradation benefits successful petroleum exploration. Anaerobic conditions prevail in petroleum reservoirs and biological hydrocarbon degradation is apparently inhibited at temperatures above 80-90 degrees C. We summarise available knowledge and conjecture on the dominant biological processes active during subsurface petroleum biodegradation. PMID:12837507

Röling, Wilfred F M; Head, Ian M; Larter, Steve R

2003-06-01

60

Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site  

NASA Astrophysics Data System (ADS)

Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m, with highest intensities close to the wellhead and decreasing intensities with increasing distance from the wellhead. Gas chromatography/mass spectrometry (GC/MS) analyses of water samples coinciding with the deep fluorescence and beam attenuation anomalies confirmed the presence of polycyclic aromatic hydrocarbons (PAH) at concentrations reaching 189 ?g L-1 (ppb). Subsurface exposure to PAH at levels considered to be toxic to marine organisms would have occurred in discrete depth layers between 1000 and 1400 m in the region southwest of the wellhead site and extending at least as far as 13 km.

Diercks, Arne-R.; Highsmith, Raymond C.; Asper, Vernon L.; Joung, DongJoo; Zhou, Zhengzhen; Guo, Laodong; Shiller, Alan M.; Joye, Samantha B.; Teske, Andreas P.; Guinasso, Norman; Wade, Terry L.; Lohrenz, Steven E.

2010-10-01

61

Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout  

NASA Astrophysics Data System (ADS)

Hydrocarbons released following the Deepwater Horizon (DH) blowout were found in deep, subsurface horizontal intrusions, yet there has been little discussion about how these intrusions formed. We have combined measured (or estimated) observations from the DH release with empirical relationships developed from previous lab experiments to identify the mechanisms responsible for intrusion formation and to characterize the DH plume. Results indicate that the intrusions originate from a stratification-dominated multiphase plume characterized by multiple subsurface intrusions containing dissolved gas and oil along with small droplets of liquid oil. Unlike earlier lab measurements, where the potential density in ambient water decreased linearly with elevation, at the DH site it varied quadratically. We have modified our method for estimating intrusion elevation under these conditions and the resulting estimates agree with observations that the majority of the hydrocarbons were found between 800 and 1200 m.

Socolofsky, Scott A.; Adams, E. Eric; Sherwood, Christopher R.

2011-05-01

62

FACT (Version 2.0) - Subsurface Flow and Contaminant Transport Documentation and User's Guide  

SciTech Connect

This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media.

Aleman, S.E.

2000-05-05

63

GEOCHEMISTRY OF SUBSURFACE REACTIVE BARRIERS FOR REMEDIATION OF CONTAMINATED GROUND WATER  

EPA Science Inventory

Reactive barriers that couple subsurface fluid flow with a passive chemical treatment zone are emerging, cost effective approaches for in-situ remediation of contaminated groundwater. Factors such as the build-up of surface precipitates, bio-fouling, and changes in subsurface tr...

64

Soil ventilation: Effects on microbial populations in gasoline-contaminated subsurface soils  

Microsoft Academic Search

Short- and long-term effects of vapor extraction (VE) in an unsaturated subsurface soil and in situ biodegradation of gasoline were evaluated in a field study. Subsurface temperature, moisture, solid- and gas-phase contaminant levels, atmospheric gases, nutrient levels, and microbial population densities were measured during and after soil VE for 462 d. Microbial activity, based on in situ Oâ consumption rates,

W. J. Hickey

1995-01-01

65

Isolation and Physiology of Bacteria from Contaminated Subsurface Sediments? †  

PubMed Central

The majority of environmental microorganisms cannot be grown by traditional techniques. Here we employed, and contrasted with conventional plating, an alternative approach based on cultivation of microorganisms inside diffusion chambers incubated within natural samples, followed by subculturing in petri dishes. Using this approach, we isolated microorganisms from subsurface sediments from the Field Research Center (FRC) in Oak Ridge, TN. The sediments were acidic and highly contaminated with uranium, heavy metals, nitrate, and organic pollutants. Phylogenetic analysis of 16S rRNA gene sequences revealed clear differences between diversity of isolates obtained by the diffusion chamber approach and those obtained by conventional plating. The latter approach led to isolation of members of the Alpha- and Gammaproteobacteria, Actinobacteria, and Verrucomicrobia. Isolates obtained via the diffusion chamber approach represented the Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. Notably, one-third of the isolates obtained by the new method were closely related to species known from previous molecular surveys conducted in the FRC area. Since the initial growth of microorganisms inside diffusion chambers occurred in the presence of the environmental stress factors, we expected the isolates we obtained to be tolerant of these factors. We investigated the physiologies of selected isolates and discovered that the majority were indeed capable of growth under low pH and/or high concentrations of heavy metals and nitrate. This indicated that in contrast to conventional isolation, the diffusion chamber-based approach leads to isolation of species that are novel, exhibit tolerance to extant environmental conditions, and match some of the species previously discovered by molecular methods.

Bollmann, Annette; Palumbo, Anthony V.; Lewis, Kim; Epstein, Slava S.

2010-01-01

66

Biogeochemical Processes In Ethanol Stimulated Uranium Contaminated Subsurface Sediments  

SciTech Connect

A laboratory incubation experiment was conducted with uranium contaminated subsurface sediment to assess the geochemical and microbial community response to ethanol amendment. A classical sequence of TEAPs was observed in ethanol-amended slurries, with NO3- reduction, Fe(III) reduction, SO4 2- reduction, and CH4 production proceeding in sequence until all of the added 13C-ethanol (9 mM) was consumed. Approximately 60% of the U(VI) content of the sediment was reduced during the period of Fe(III) reduction. No additional U(VI) reduction took place during the sulfate-reducing and methanogenic phases of the experiment. Only gradual reduction of NO3 -, and no reduction of U(VI), took place in ethanol-free slurries. Stimulation of additional Fe(III) or SO4 2- reduction in the ethanol-amended slurries failed to promote further U(VI) reduction. Reverse transcribed 16S rRNA clone libraries revealed major increases in the abundance of organisms related to Dechloromonas, Geobacter, and Oxalobacter in the ethanolamended slurries. PLFAs indicative of Geobacter showed a distinct increase in the amended slurries, and analysis of PLFA 13C/12C ratios confirmed the incorporation of ethanol into these PLFAs. A increase in the abundance of 13C-labeled PLFAs indicative of Desulfobacter, Desulfotomaculum, and Desulfovibrio took place during the brief period of sulfate reduction which followed the Fe(III) reduction phase. Our results show that major redox processes in ethanol-amended sediments can be reliably interpreted in terms of standard conceptual models of TEAPs in sediments. However, the redox speciation of uranium is complex and cannot be explained based on simplified thermodynamic considerations.

Mohanty, Santosh R.; Kollah, Bharati; Hedrick, David B.; Peacock, Aaron D.; Kukkadapu, Ravi K.; Roden, Eric E.

2008-06-15

67

Isolation and physiology of bacteria from contaminated subsurface sediments.  

PubMed

The majority of environmental microorganisms cannot be grown by traditional techniques. Here we employed, and contrasted with conventional plating, an alternative approach based on cultivation of microorganisms inside diffusion chambers incubated within natural samples, followed by subculturing in petri dishes. Using this approach, we isolated microorganisms from subsurface sediments from the Field Research Center (FRC) in Oak Ridge, TN. The sediments were acidic and highly contaminated with uranium, heavy metals, nitrate, and organic pollutants. Phylogenetic analysis of 16S rRNA gene sequences revealed clear differences between diversity of isolates obtained by the diffusion chamber approach and those obtained by conventional plating. The latter approach led to isolation of members of the Alpha- and Gammaproteobacteria, Actinobacteria, and Verrucomicrobia. Isolates obtained via the diffusion chamber approach represented the Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. Notably, one-third of the isolates obtained by the new method were closely related to species known from previous molecular surveys conducted in the FRC area. Since the initial growth of microorganisms inside diffusion chambers occurred in the presence of the environmental stress factors, we expected the isolates we obtained to be tolerant of these factors. We investigated the physiologies of selected isolates and discovered that the majority were indeed capable of growth under low pH and/or high concentrations of heavy metals and nitrate. This indicated that in contrast to conventional isolation, the diffusion chamber-based approach leads to isolation of species that are novel, exhibit tolerance to extant environmental conditions, and match some of the species previously discovered by molecular methods. PMID:20870785

Bollmann, Annette; Palumbo, Anthony V; Lewis, Kim; Epstein, Slava S

2010-09-24

68

Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface  

Microsoft Academic Search

Dissimilatory Fe(III)-reducing microorganisms have the ability to destroy organic contaminants under anaerobic conditions by oxidizing them to carbon dioxide. Some Fe(III)-reducing microorganisms can also reductively dechlorinate chlorinated contaminants. Fe(III)-reducing microorganisms can reduce a variety of contaminant metals and convert them from soluble forms to forms that are likely to be immobilized in the subsurface. Studies in petroleum-contaminated aquifers have demonstrated

Derek R. Lovley; Robert T. Anderson

2000-01-01

69

Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface  

NASA Astrophysics Data System (ADS)

Dissimilatory Fe(III)-reducing microorganisms have the ability to destroy organic contaminants under anaerobic conditions by oxidizing them to carbon dioxide. Some Fe(III)-reducing microorganisms can also reductively dechlorinate chlorinated contaminants. Fe(III)-reducing microorganisms can reduce a variety of contaminant metals and convert them from soluble forms to forms that are likely to be immobilized in the subsurface. Studies in petroleum-contaminated aquifers have demonstrated that Fe(III)-reducing microorganisms can be effective agents in removing aromatic hydrocarbons from groundwater under anaerobic conditions. Laboratory studies have demonstrated the potential for Fe(III)-reducing microorganisms to remove uranium from contaminated groundwaters. The activity of Fe(III)-reducing microorganisms can be stimulated in several ways to enhance organic contaminant oxidation and metal reduction. Molecular analyses in both field and laboratory studies have demonstrated that microorganisms of the genus Geobacter become dominant members of the microbial community when Fe(III)-reducing conditions develop as the result of organic contamination, or when Fe(III) reduction is artificially stimulated. These results suggest that further understanding of the ecophysiology of Geobacter species would aid in better prediction of the natural attenuation of organic contaminants under anaerobic conditions and in the design of strategies for the bioremediation of subsurface metal contamination. Des micro-organismes simulant la réduction du fer ont la capacité de détruire des polluants organiques dans des conditions anérobies en les oxydant en dioxyde de carbone. Certains micro-organismes réducteurs de fer peuvent aussi dé-chlorer par réduction des polluants chlorés. Des micro-organismes réducteurs de fer peuvent réduire tout un ensemble de métaux polluants et les faire passer de formes solubles à des formes qui sont susceptibles d'être immobilisées dans le milieu souterrain. Des études d'aquifères pollués par du pétrole ont montré que des micro-organismes réducteurs de fer peuvent être des agents efficaces pour éliminer les hydrocarbures aromatiques des eaux souterraines dans des conditions anérobies. Des études en laboratoire ont montré que des micro-organismes réducteurs de fer avaient la capacité d'éliminer l'uranium d'eaux souterraines polluées. L'activité de micro-organismes réducteurs de fer peut être stimulée de différentes manières pour augmenter l'oxydation de polluants organiques et la réduction de métaux. Des analyses moléculaires concernant des études de terrain et de laboratoire ont montré que des micro-organismes du genre Geobacter deviennent les membres dominants de la communauté microbienne quand les conditions de réduction en Fe(III) sont réalisées à la suite d'une pollution organique, ou lorsque la réduction en Fe(III) est stimulée artificiellement. Ces résultats laissent penser que des connaissances supplémentaires sur l'écophysiologie des espèces Geobacter devraient aider à une meilleure prédiction de la diminution naturelle des teneurs en polluants organiques dans des conditions anérobies, ainsi qu'à la définition de stratégies de dépollution biologique de pollutions souterraines par les métaux. Algunos microorganismos Fe(III)-reductores son capaces de destruir selectivamente determinados contaminantes orgánicos en condiciones anaerobias, oxidándolos a dióxido de carbono. Otros de estos microorganismos Fe(III)-reductores pueden reducir, bien compuestos clorados, bien una gran variedad de metales, que dejan de ser solubles y se inmovilizan en el subsuelo. Estudios realizados en acuéferos contaminados por petróleo muestran que los microorganismos Fe(III)-reductores pueden ser unos agentes muy eficientes para eliminar los hidrocarburos aromáticos de las aguas subterráneas en condiciones anaerobias, mientras que estudios de laboratorio muestran el potencial de estos microorganismos para eliminar uranio. La actividad de los microorganismos Fe(III)-reductor

Lovley, Derek R.; Anderson, Robert T.

70

Hydrocarbon conversion of sulfur contaminated feed stock  

SciTech Connect

In the alkylation of aromatic hydrocarbons a method is described which consists of passing a feedstream of an alkylating agent and an aromatic substrate and containing sulfur in an amount greater than two ppm to a reaction zone containing a crystalline silica polymorph silicalite catalyst under conditions providing for the alkylation of the aromatic substrate.

Forward, C.H.; Butler, J.R.; Licht, W.P.

1986-05-06

71

Does historical exposure to hydrocarbon contamination alter the response of benthic communities to diesel contamination?  

Microsoft Academic Search

A microcosm experiment was used to compare the influence of diesel contamination on two benthic salt-marsh communities, one chronically exposed to petroleum hydrocarbons for decades (Louisiana [LA]) and the other relatively uncontaminated (Mississippi [MS]). Initial meiofaunal community composition of the two sites was similar. Higher organic content of MS sediments should have reduced bioavailability, and thus the toxicity of hydrocarbons

K. R. Carman; J. W. Fleeger; S. M. Pomarico

2000-01-01

72

Viscosity of high-alcohol content fuel blends with water: Subsurface contaminant transport implications  

Microsoft Academic Search

In the United States, a gasoline fuel blend with alcohol volume fractions of 85% or more is considered (among other fuels) an alternative fuel. As the popularity and usage of high-alcohol content gasoline fuel blends increase, subsurface contamination from these fuels will be of great environmental concern. An important parameter governing the movement of these contaminants in unsaturated porous media

Kenneth Y. Lee

2008-01-01

73

Contaminant Removal Processes in Subsurface-Flow Constructed Wetlands: A Review  

Microsoft Academic Search

The main contaminant removal processes occurring in subsurface-flow constructed wetlands treating wastewater are reviewed. Redox conditions prevailing in the wetlands are analyzed and linked to contaminant removal mechanisms. The removal of organic matter and its accumulation in the granular medium of the wetlands are evaluated with regard to particulate and dissolved components and clogging processes. The main biological processes linked

JOAN GARCÍA; DIEDERIK P. L. ROUSSEAU; JORDI MORATÓ; ELS LESAGE; VICTOR MATAMOROS; JOSEP M. BAYONA

2010-01-01

74

Geochemical and isotopic characteristics associated with high electrical conductivities in a shallow hydrocarbon-contaminated aquifer  

NASA Astrophysics Data System (ADS)

Data collected from a network of in-situ vertical resistivity probes (VRPs) deployed within a hydrocarbon contaminated aquifer showed high soil conductivities associated with zones where residual and dissolved phase hydrocarbons (RDH) occur and zones where these phases coexist with free phase hydrocarbons (RDFH). Bulk soil conductivities were highest (12 to 30 mS/m) in the RDFH zone compared to the RDH zone (10 to 25 mS/m). Groundwater from closely spaced multi-level piezometers (MLPs) installed in the aquifer was analyzed to investigate the role of mineral weathering as the source of ions responsible for the high soil conductivity. Evidence for mineral weathering in the aquifer was assessed using major inorganic ions, dissolved inorganic carbon (DIC), stable carbon isotope ratio of DIC (?13CDIC), and bulk soil conductivity. The link between bulk soil conductivity and ?13CDIC in contaminant plumes has never been reported in the literature. The results show higher Na, Ca, and Mg in the contaminated zone compared to background. The higher TDS in the contaminated zones is consistent with the weathering of carbonates and Na and Ca feldspars, the dominant minerals in the aquifer. Higher TDS at the contaminated locations was also coincident with higher DIC. The ?13CDIC values of 16.9 to 9.5 ppm suggest that DIC evolution within this zone is controlled by carbonate dissolution through enhanced CO_2 production related to microbial hydrocarbon degradation. Within the range of ?13CDIC values reported for groundwater at the RDH locations, the more positive ?13CDIC values were observed in zones where reduction of NO_3, Mn(IV), Fe(III), and SO_4 was occurring and was coincident with higher bulk soil conductivity. Within the portion of the aquifer with RDFH, ?13CDIC ranged from +6.5 to 4.4 ppm, suggesting that methanogenesis is the dominant redox process at this location. High DIC within the methanogenic zone is also coincident with higher bulk soil conductivity. Thus the subsurface expression of microbial hydrocarbon mineralization is recorded in the TDS, DIC, ?13CDIC, and bulk soil conductivity. It also appears that the bulk soil conductivity records an integrated summary of process-driven biogeochemical changes reflected in the changing pattern of redox zonation. This suggests that high soil conductivities measured at hydrocarbon-contaminated sites could be used to assess the potential for natural attenuation and to monitor intrinsic bioremediation at these sites.

Legall, F.; Atekwana, E.; Atekwana, E.; Krishnamurthy, R.; Sauck, W.

2003-04-01

75

INFLUENCE OF COUPLED PROCESSES ON CONTAMINANT FATE AND TRANSPORT IN SUBSURFACE ENVIRONMENTS  

SciTech Connect

The following chapter emphasizes subsurface environmental research investigations over the past 10 to 15 years that couple hydrological, geochemical, and biological processes as related to contaminant fate and transport. An attempt is made to focus on field-scale studies with possible reference to laboratory-scale endeavors. Much of the research discussed reflects investigations of the influence of coupled processes on the fate and transport of inorganic, radionuclide, and organic contaminants in subsurface environments as a result of natural processes or energy and weapons production endeavors that required waste disposal. The chapter provides on overview of the interaction between hydro-bio-geochemical processes in structured, heterogeneous subsurface environments and how these interactions control contaminant fate and transport, followed by experimental and numerical subsurface science research and case studies involving specific classes of inorganic and organic contaminants. Lastly, thought provoking insights are highlighted on why the study of subsurface coupled processes is paramount to understanding potential future contaminant fate and transport issues of global concern.

Jardine, Philip M [ORNL

2008-01-01

76

Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer  

SciTech Connect

Current efforts to remediate subsurface contamination have spurred research in the application of in situ bioremediation. In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with {sup 14}C-labeled organic compounds, and the evolution of {sup 14}CO{sub 2} was measured over time. Gas chromatographic analyses were used to monitor CO{sub 2} production and O{sub 2} consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. {sup 14}CO{sub 2} was measured from ({sup 14}C)glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total ({sup 14}C)glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of {sup 14}C label. ({sup 14}C)benzene and ({sup 14}C)toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO{sub 3}, CO{sub 2} production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rte of 0.099 {mu}mol g{sup {minus}1} (dry weight) day{sup {minus}1} while oxygen concentration decreased at a rate of 0.124 {mu}mol g{sup {minus}1} (dry weight) day{sup {minus}1}. With no added nitrate, CO{sub 2} production was not different from that in metabolically inhibited control vials. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific. Also, the community is strongly nitrogen limited, and nitrogen additions may be required to significantly enhance hydrocarbon biodegradation.

Aelion, C.M.; Bradley, P.M. (U.S. Geological Survey, Columbia, SC (USA) Univ. of South Carolina, Columbia (USA))

1991-01-01

77

Review of Geophysical Techniques to Define the Spatial Distribution of Subsurface Properties or Contaminants  

SciTech Connect

This is a letter report to Fluor Hanford, Inc. The purpose of this report is to summarize state-of-the-art, minimally intrusive geophysical techniques that can be used to clarify subsurface geology, structure, moisture, and chemical composition. The technology review focused on geophysical characterization techniques that provide two- or three-dimensional information about the spatial distribution of subsurface properties and/or contaminants.

Murray, Christopher J.; Last, George V.; Truex, Michael J.

2005-08-22

78

Apparatus for removing hydrocarbon contaminants from solid materials  

DOEpatents

A system is described for removing hydrocarbons from solid materials. Contaminated solids are combined with a solvent (preferably terpene based) to produce a mixture. The mixture is washed with water to generate a purified solid product (which is removed from the system) and a drainage product. The drainage product is separated into a first fraction (consisting mostly of contaminated solvent) and a second fraction (containing solids and water). The first fraction is separated into a third fraction (consisting mostly of contaminated solvent) and a fourth fraction (containing residual solids and water). The fourth fraction is combined with the second fraction to produce a sludge which is separated into a fifth fraction (containing water which is ultimately reused) and a sixth fraction (containing solids). The third fraction is then separated into a seventh fraction (consisting of recovered solvent which is ultimately reused) and an eighth fraction (containing hydrocarbon waste). 4 figs.

Bala, G.A.; Thomas, C.P.

1996-02-13

79

Monitoring Contamination of the subsurface with Quasi-Static Deformation  

Microsoft Academic Search

Data from a field experiment suggest that we can detect the infiltration of contaminated water (contaminated with 150 ppm of a biosurfactant, Rhamnolipid) into the vadose zone with tilt meters. Three sets of instruments were installed in the vicinity of a 50m x 50m field, which was instrumented and could be irrigated in a controlled manner. Each set consisted of

H. Spetzler; R. Snieder; J. Zhang

2005-01-01

80

Uranium Contamination in the Subsurface Beneath the 300 Area, Hanford Site, Washington  

SciTech Connect

This report provides a description of uranium contamination in the subsurface at the Hanford Site's 300 Area. The principal focus is a persistence plume in groundwater, which has not attenuated as predicted by earlier remedial investigations. Included in the report are chapters on current conditions, hydrogeologic framework, groundwater flow modeling, and geochemical considerations. The report is intended to describe what is known or inferred about the uranium contamination for the purpose of making remedial action decisions.

Peterson, Robert E.; Rockhold, Mark L.; Serne, R. Jeffrey; Thorne, Paul D.; Williams, Mark D.

2008-02-29

81

Characterization of Metal-Reducing Microbial Communities from Acidic Subsurface Sediments Contaminated with Uranium(VI)  

Microsoft Academic Search

Extraction and processing of uranium ore during the Cold-War era have left many sites around the world contaminated with uranium. Leaching of uranium into the groundwater is of major concern because oxidized uranium, U(VI), is toxic, soluble, and therefore mobile in subsurface environments where the majority of contamination resides. Uranium [U(VI)] can be immobilized from water by its reduction from

Ellen McLain Edwards

2004-01-01

82

Computational methods for multiphase flow and reactive transport problems arising in subsurface contaminant remediation  

Microsoft Academic Search

A mathematical formulation and some numerical approximation techniques are described for a system of coupled partial differential and algebraic equations describing multiphase flow, transport and interactions of chemical species in the subsurface. A parallel simulator PARSIM has been developed based on these approximation techniques and is being used to study contaminant remediation strategies. Numerical results for a highly complex geochemistry

Todd Arbogast; Steve Bryant; Clint Dawson; Fredrik Saaf; Chong Wang; Mary Wheeler

1996-01-01

83

SPECIATION OF SUBSURFACE CONTAMINANTS BY CONE PENETROMETRY GAS CHROMATOGRAPHY/MASS SPECTROMETRY. (R826184)  

EPA Science Inventory

A thermal extraction cone penetrometry gas chroma tography/mass spectrometry system (TECP GC/MS) has been developed to detect subsurface contaminants in situ. The TECP can collect soil-bound organics up to depths of 30 m. In contrast to traditional cone penetrometer sample collec...

84

Remediation of DNAPL-contaminated subsurface systems using density-motivated mobilization  

Microsoft Academic Search

Dense nonaqueous phase liquids (DNAPLs), especially when present as trapped free-phase pools, are long-lived in the subsurface environment and extremely difficult to remove. Despite vigorous research efforts over the last two decades, all current DNAPL pool remediation strategies suffer from a combination of inefficiency, increased risk of contaminant spreading due to uncontrolled mobilization, and or high treatment costs. This work

C. T. Miller; E. H. Hill; M. Moutier

2000-01-01

85

Transport of Contaminants in the Subsurface: The Role of Organic and Inorganic Colloidal Particles: Summary Report.  

National Technical Information Service (NTIS)

Current knowledge was reviewed about the role played by colloids on the mobility of contaminants in the subsurface environment, and to identify important long-term research needs in this area. Recent findings on the occurrence and nature of colloidal mate...

1986-01-01

86

Closure End States for Facilities, Waste Sites, and Subsurface Contamination  

SciTech Connect

The United States (U.S.) Department of Energy (DOE) manages the largest groundwater and soil cleanup effort in the world. DOE’s Office of Environmental Management (EM) has made significant progress in its restoration efforts at sites such as Fernald and Rocky Flats. However, remaining sites, such as Savannah River Site, Oak Ridge Site, Hanford Site, Los Alamos, Paducah Gaseous Diffusion Plant, Portsmouth Gaseous Diffusion Plant, and West Valley Demonstration Project possess the most complex challenges ever encountered by the technical community and represent a challenge that will face DOE for the next decade. Closure of the remaining 18 sites in the DOE EM Program requires remediation of 75 million cubic yards of contaminated soil and 1.7 trillion gallons of contaminated groundwater, deactivation & decommissioning (D&D) of over 3000 contaminated facilities and thousands of miles of contaminated piping, removal and disposition of millions of cubic yards of legacy materials, treatment of millions of gallons of high level tank waste and disposition of hundreds of contaminated tanks. The financial obligation required to remediate this volume of contaminated environment is estimated to cost more than 7% of the to-go life-cycle cost. Critical in meeting this goal within the current life-cycle cost projections is defining technically achievable end states that formally acknowledge that remedial goals will not be achieved for a long time and that residual contamination will be managed in the interim in ways that are protective of human health and environment. Formally acknowledging the long timeframe needed for remediation can be a basis for establishing common expectations for remedy performance, thereby minimizing the risk of re-evaluating the selected remedy at a later time. Once the expectations for long-term management are in place, remedial efforts can be directed towards near-term objectives (e.g., reducing the risk of exposure to residual contamination) instead of focusing on long-term cleanup requirements. An acknowledgement of the long timeframe for complete restoration and the need for long-term management can also help a site transition from the process of pilot testing different remedial strategies to selecting a final remedy and establishing a long-term management and monitoring approach. This approach has led to cost savings and the more efficient use of resources across the Department of Defense complex and at numerous industrial sites across the U.S. Defensible end states provide numerous benefits for the DOE environmental remediation programs including cost-effective, sustainable long-term monitoring strategies, remediation and site transition decision support, and long-term management of closure sites.

Gerdes, Kurt D.; Chamberlain, Grover S.; Wellman, Dawn M.; Deeb, Rula A.; Hawley, Elizabeth L.; Whitehurst, Latrincy; Marble, Justin

2012-11-21

87

Subsurface ecosystem resilience: long-term attenuation of subsurface contaminants supports a dynamic microbial community  

Microsoft Academic Search

The propensity for groundwater ecosystems to recover from contamination by organic chemicals (in this case, coal-tar waste) is of vital concern for scientists and engineers who manage polluted sites. The microbially mediated cleanup processes are also of interest to ecologists because they are an important mechanism for the resilience of ecosystems. In this study we establish the long-term dynamic nature

Jane M Yagi; Edward F Neuhauser; John A Ripp; David M Mauro; Eugene L Madsen

2010-01-01

88

Unraveling contaminated subsurface complex and dynamic behavior: A scale-dependent perspective  

NASA Astrophysics Data System (ADS)

The uranium plumes present at the United States Department of Energy's (DOE) Hanford site (WA) and Rifle site (CO), have not attenuated as previously expected and predicted due, most likely, to subsurface complex behavior and multiple sources of contaminant uranium. At the Rifle site, both oxidized and naturally reduced zones are present in the subsurface. The naturally reduced zones usually contain high U concentrations, and are likely significant contributors to the groundwater contamination. We have conducted hypothesis driven research to generate the necessary scientific information needed to: 1. Understand and overcome the physical and mineralogical subsurface heterogeneities; 2. Unravel mineral - fluid interface complexity and dynamics by identifying and estimating the role of key geochemical and hydrological reactions and processes controlling contaminant uranium behavior under a variety of conditions; 3. Develop conceptual models and apply predictive models of contaminant behavior to support development, implementation and monitoring of effective and sustainable remediation approaches. In this talk, results from research efforts, such as wet chemical extractions of different types, as well as, batch and hydraulically saturated and unsaturated column experiments of different types, will be presented. These results were combined with those of a variety of techniques such as XRD, µ-XRD, SEM-EDS, SEM-FIB, TEM-SAED, Mössbauer spectroscopy, EMPA, µXRF and XANES. Collectively, these results provided information about the extent and rates of geochemical (sorption/desorption, dissolution/precipitation and redox) and hydrological reactions and processes which control and/or significantly affect the fate of uranium and other co-contaminants that are present in these contaminated subsurface media.

Qafoku, N.

2012-04-01

89

Surface and subsurface characterization of uranium contamination at the Fernald environmental management site  

SciTech Connect

The past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils, and the three-dimensional distribution of the uranium at these sites must be thoroughly characterized before any effective remedial protocols can be established. To this end, Pacific Northwest Laboratory (PNL) has been tasked by the DOE`s Office of Technology Development with adapting, developing, and demonstrating technologies for the measurement of uranium in surface and subsurface soils at the Fernald Uranium in Soils Integrated Demonstration site. These studies are detailed in this report.

Schilk, A.J.; Perkins, R.W.; Abel, K.H.; Brodzinski, R.L.

1993-04-01

90

The stability and utility of diagnostic ratio hydrocarbon fingerprinting for soils contaminated with petroleum hydrocarbons  

SciTech Connect

In order to recover costs for oil spill cleanup and restoration regulatory agencies and trustees of natural resources are interested in identifying parties responsible for hydrocarbon releases, and for associated environmental damages. Chemical analyses of contaminated soil and groundwater samples are currently used to identify the sources of contamination in soil and groundwater systems. However, conventional hydrocarbon fingerprinting approaches such as EPA Method 8015, EPA Method 8270, and ASTM Method 3328-91 afford a low resolution fingerprint that is easily degraded in the environment. The challenge to the hydrocarbon chemist is to develop an analytical approach that minimizes the impact of environmental weathering and biodegradation on the oil signature and improves the accuracy of oil source identification. An advanced chemical fingerprinting strategy is presented that combines sensitive and hydrocarbon specific analytical methods with a detailed interpretive strategy designed to minimize the impacts of environmental weathering and biodegradation. Data will be presented from a series of oil biodegradation studies in soil that clearly demonstrate the utility and stability of source ratio analysis over a wide range of oil degradation states and oil types. Using principal component analysis, stable source ratios of C[sub 3]-dibenzothiophenes/C[sub 3]-phenanthrenes, and C[sub 2]-dibenzothiophenes/C[sub 2]-phenanthrenes were identified and evaluated. These source ratios retain their characteristic source ratio signature even after 95 percent of the PAH and dibenzothiophene target analytes and 70 percent of the total oil has been biodegraded.

Douglas, G.S.; Sara McMillen

1996-01-01

91

Hydrocarbon contamination decreases mating success in a marine planktonic copepod.  

PubMed

The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1%) impacts (i) the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii) the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF) significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics. PMID:22053187

Seuront, Laurent

2011-10-28

92

Hydrocarbon Contamination Decreases Mating Success in a Marine Planktonic Copepod  

PubMed Central

The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1%) impacts (i) the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii) the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF) significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics.

Seuront, Laurent

2011-01-01

93

Subsurface biobarrier formation by microorganism injection for contaminant plume control.  

PubMed

The concept of an in situ mixture of residual soil and aerobic microorganisms as a biobarrier for controlling contaminant plume was evaluated in this study. Azotobacter chroococcum was inoculated into soil with oxygen as the electron acceptor and appropriate substrate to induce biofilm clog soil pores. The hydraulic conductivity of soil decreased by 1/8000 while substrate and oxygen were provided to the injected microorganism, and increased by 400% when no substrate was provided. A series of column experiments were carried out to measure the hydraulic conductivity of soil specimens. The results showed that the highest hydraulic conductivity reduction occurred when the substrate and electron acceptors were first introduced, and this reduction increased toward the outlet of the column. The substrate was consumed mostly at the inlet and was distributed with time. The analysis of volatile substances after the test showed that the inlet had a high organic content and the outlet had a low organic content. PMID:16569610

Kim, Geonha; Lee, Seungbong; Kim, Younguk

2006-02-01

94

Scale-dependent desorption of uranium from contaminated subsurface sediments  

SciTech Connect

Column experiments were performed to investigate the scale-dependent desorption of uranyl [U(VI)] from a contaminated sediment collected from the Hanford 300 Area at the US Department of Energy (DOE) Hanford Site, Washington. The sediment was a coarse-textured alluvial flood deposit containing significant mass percentage of river cobble. U(VI) was, however, only associated with its minor, fine-grained (< 2mm) mass fraction. U(VI) desorption was investigated both from the field-textured sediment using a large column (80 cm length by 15 cm inner diameter), and from its < 2mm, U(VI)-associated mass fraction using a small column (10 cm length by 3.4 cm inner diameter). Dynamic advection conditions with intermittent flow and stop-flow events of variable durations were employed to investigate U(VI) desorption kinetics and its scale dependence. A multi-component kinetic model that integrated a distributed rate expression with surface complexation reactions successfully described U(VI) release from the fine-grained, U(VI)-associated materials. The field-textured sediment in the large column displayed dual domain, tracer-dependent mass transfer properties that affected the breakthrough curves of bromide, pentafluorobenzoic acid (PFBA), and tritium. The tritium breakthrough curve showed stronger non-equilibrium behavior than did PFBA and bromide, and required a larger immobile porosity to describe. The dual domain mass transfer properties were then used to scale the kinetic model of U(VI) desorption developed for the fine-grained materials to describe U(VI) release and reactive transport in the field-textured sediment. Numerical simulations indicated that the kinetic model that was integrated with the dual domain properties determined from tracer PFBA and Br best described the experimental results. The kinetic model without consideration of the dual domain properties over-predicted effluent U(VI) concentrations, while the model based on tritium mass transfer under-predicted the rate of U(VI) release. Overall, our results indicated that the kinetics of U(VI) release from the field-textured sediment were different from that of its fine-grained, U(VI)-associated mass fraction. However, the desorption kinetics measured on the U(VI)-containing mass fraction could be scaled to describe U(VI) reactive transport in the contaminated field-textured sediment after proper consideration of the physical transport properties of the sediment. The research also demonstrated a modeling approach to integrate geochemical processes into field scale reactive transport models.

Liu, Chongxuan; Zachara, John M.; Qafoku, Nik; Wang, Zheming

2008-08-08

95

Magnetic properties changes due to hydrocarbon contaminated groundwater table fluctuations  

NASA Astrophysics Data System (ADS)

This study aims to understand the mechanisms and conditions which control the formation and transformation of ferro(i)magnetic minerals caused by hydrocarbon contaminated groundwater, in particular in the zone of fluctuating water levels. The work extends previous studies conducted at the same site. The study area is a former military air base at Hrad?any, Czech Republic (50°37'22.71"N, 14°45'2.24"E). The site was heavily contaminated with petroleum hydrocarbons, due to leaks in petroleum storage tanks and jet fuelling stations over years of active use by the Soviet Union, which closed the base in 1991. The site is one of the most important sources of high quality groundwater in the Czech Republic. In a previous study, Rijal et al. (2010) concluded that the contaminants could be flushed into the sediments as the water level rose due to remediation processes leading to new formation of magnetite. In this previous study three different locations were investigated; however, from each location only one core was obtained. In order to recognize significant magnetic signatures versus depth three cores from each of these three locations were drilled in early 2012, penetrating the unsaturated zone, the groundwater fluctuation (GWF) zone and extending to about one meter below the groundwater level (~2.3 m depth at the time of sampling). Magnetic susceptibility (MS) profiles combined with other magnetic properties were analyzed to obtain a significant depth distribution of the ferro(i)magnetic concentration. Sediment properties, hydrocarbon content and bacterial activity were additionally studied. The results show that the highest ferrimagnetic mineral concentrations exist between 1.4-1.9 m depth from the baseline which is interpreted as the top of the GWF zone. Spikes of MS detected in the previous studies turned out to represent small-scale isolated features, but the trend of increasing MS values from the lowermost position of the groundwater table upward was verified. Mineral magnetic parameters indicate that magnetite is responsible for the MS signal which confirms the previous results (Rijal et al., 2010). The so far existing uncertainty of the groundwater level position could be solved. Bacterial activity is studied at particular depth horizons as it is assumed to be responsible for iron mineralogy changes. References: Rijal M.L., Appel E., Petrovský E. and Blaha U., 2010. Change of magnetic properties due to fluctuations of hydrocarbon contaminated groundwater in unconsolidated sediments. Environ.Pollut., 158, 1756-1762.

Ameen, Nawrass

2013-04-01

96

Bioremediation of uranium-contaminated groundwater: a systems approach to subsurface biogeochemistry.  

PubMed

Adding organic electron donors to stimulate microbial reduction of highly soluble U(VI) to less soluble U(IV) is a promising strategy for immobilizing uranium in contaminated subsurface environments. Studies suggest that diagnosing the in situ physiological status of the subsurface community during uranium bioremediation with environmental transcriptomic and proteomic techniques can identify factors potentially limiting U(VI) reduction activity. Models which couple genome-scale in silico representations of the metabolism of key microbial populations with geochemical and hydrological models may be able to predict the outcome of bioremediation strategies and aid in the development of new approaches. Concerns remain about the long-term stability of sequestered U(IV) minerals and the release of co-contaminants associated with Fe(III) oxides, which might be overcome through targeted delivery of electrons to select microorganisms using in situ electrodes. PMID:23159488

Williams, Kenneth H; Bargar, John R; Lloyd, Jonathan R; Lovley, Derek R

2012-11-16

97

Historical Perspective on Subsurface Contaminants Focus Area (SCFA) Success: Counting the Things That Really Count  

SciTech Connect

The Subsurface Contaminants Focus Area, (SCFA) is committed to, and has been accountable for, identifying and providing solutions for the most pressing subsurface contamination problems in the DOE Complex. The SCFA program is a DOE end user focused and problem driven organization that provides the best technical solutions for the highest priority problems. This paper will discuss in some detail specific examples of the most successful, innovative technical solutions and the DOE sites where they were deployed or demonstrated. These solutions exhibited outstanding performance in FY 2000/2001 and appear poised to achieve significant success in saving end users money and time. They also provide a reduction in risk to the environment, workers, and the public while expediting environmental clean up of the sites.

Wright, J. A. Jr.; Middleman, L. I.

2002-02-27

98

A physically-based integrated numerical model for flow, upland erosion, and contaminant transport in surface-subsurface systems  

Microsoft Academic Search

This paper presents a physically-based integrated hydrologic model that can simulate the rainfall-induced 2D surface water\\u000a flow, 3D variably saturated subsurface flow, upland soil erosion and transport, and contaminant transport in the surface-subsurface\\u000a system of a watershed. The model couples surface and subsurface flows based on the assumption of continuity conditions of\\u000a pressure head and exchange flux at the ground,

ZhiGuo He; WeiMing Wu

2009-01-01

99

CsI(Tl) with photodiodes for identifying subsurface radionuclide contamination  

Microsoft Academic Search

A cylindrical (15×61 mm) CsI(Tl) scintillation detector with two side-mounted photodiodes has been developed to collect spectral gamma-ray data in subsurface contaminated formations at the US Department of Energy's Hanford Site. It operates inside small-diameter, thick-wall steel pipes pushed into the ground to depths up to 20 m by a cone penetrometer system. The detector provides a rugged, efficient, magnetic-field-insensitive

J. E. Meisner; W. F. Nicaise; D. C. Stromswold

1995-01-01

100

CsI(Tl) with photodiodes for identifying subsurface radionuclide contamination  

Microsoft Academic Search

A cylindrical (15×61 mm) CsI(Tl) scintillation detector with two side-mounted photodiodes has been developed to collect spectral gamma-ray data in subsurface contaminated formations at the US Department of Energy's Hanford Site. It operates inside small-diameter, thick-wall steel pipes pushed into the ground to depths up to 20 m by a cone penetrometer system. The detector provides a rugged, efficient, magnetic-field-insensitive

J. E. Meisner; W. F. Nicaise; D. C. Stromswold

1994-01-01

101

Phytosiderophore effects on subsurface actinide contaminants: potential for phytostabilization and phytoextraction  

Microsoft Academic Search

In recognition of the need for a safe, effective technology for long term Pu\\/Th\\/Actinide stabilization or removal from soils, we have begun an investigation of the potential for phytoremediation (phytostabilization and\\/or phytoextraction) of Pu and other actinide soil contaminants at DOE sites using phytosiderophore producing plants, and are investigating the contribution of phytosiderophores to actinide mobility in the subsurface environment.

C. E. Ruggiero; S. N. Twary; E. Deladurantaye

2003-01-01

102

Use of solvent extraction to remediate soils contaminated with hydrocarbons.  

PubMed

The main objective of this research is to exploit the possibility of using an ex situ solvent extraction technique for the remediation of soils contaminated with semi-volatile petroleum hydrocarbons. The composition of the organic phase was chosen in order to form a single phase mixture with an aqueous phase and simultaneously not being disturbed (forming stable emulsions) by the soil particles hauling the contaminants. It should also permit a regeneration of the organic solvent phase. As first, we studied the miscibility domain of the chosen ternary systems constituted by ethyl acetate-acetone-water. This system proved to satisfy the previous requirements allowing for the formation of a single liquid phase mixture within a large spectrum of compositions, and also allowing for an intimate contact with the soil. Contaminants in the diesel range within different functional groups were selected: xylene, naphthalene and hexadecane. The analytical control was done by gas chromatography with FID detector. The kinetics of the extractions proved to be fast, leading to equilibrium after 10 min. The effect of the solid-liquid ratio on the extraction efficiency was studied. Lower S/L ratios (1:8, w/v) proved to be more efficient, reaching recoveries in the order of 95%. The option of extraction in multiple contacts did not improve the recovery in relation to a single contact. The solvent can be regenerated by distillation with a loss around 10%. The contaminants are not evaporated and they remain in the non-volatile phase. The global results show that the ex situ solvent extraction is technically a feasible option for the remediation of semi-volatile aromatic, polyaromatic and linear hydrocarbons. PMID:16006033

Silva, Aurora; Delerue-Matos, Cristina; Fiúza, A

2005-09-30

103

Technical Targets - A Tool to Support Strategic Planning in the Subsurface Contaminants Focus Area  

SciTech Connect

The Subsurface Contaminants Focus Area (SCFA) is supported by a lead laboratory consisting of technical representatives from DOE laboratories across the country. This broadly representative scientific group has developed and implemented a process to define Technical Targets to assist the SCFA in strategic planning and in managing their environmental research and development portfolio. At an initial meeting in Golden Colorado, an initial set of Technical Targets was identified using a rapid consensus based technical triage process. Thirteen Technical Targets were identified and described. Vital scientific and technical objectives were generated for each target. The targets generally fall into one of the following five strategic investment categories: Enhancing Environmental Stewardship, Eliminating Contaminant Sources, Isolating Contaminants, Controlling Contaminant Plumes, Enabling DOEs CleanUp Efforts. The resulting targets and the detail they comprise on what is, and what is not, needed to meet Environmental Management needs provide a comprehensive technically-based framework to assist in prioritizing future work and in managing the SCFA program.

Looney, B.B.

2002-02-11

104

ASSESSING UST CORRECTIVE ACTION TECHNOLOGY: A SCIENTIFIC EVALUATION OF THE MOBILITY AND DEGRADABILITY OF ORGANIC CONTAMINANTS IN SUBSURFACE ENVIRONMENTS  

EPA Science Inventory

The problems associated with leakage of motor fuels and organic chemicals from underground storage tanks (USTs) are compounded by a general lack of understanding of the partitioning, retention, transformation, and transport of these contaminants in the subsurface environment. he ...

105

FIELD SCREENING OF POLYCYCLIC HYDROCARBON CONTAMINATION IN SOIL USING A PORTABLE SYNCHRONOUS SCANNING SPECTROFLUOROMETER  

EPA Science Inventory

Polycyclic aromatic hydrocarbon (PAH) contamination is a considerable problem at various hazardous waste sites. sources of PAH contamination include: incomplete combustion processes, wood preservatives, and the fuel industry. he development of rapid, cost-effective field screenin...

106

Characterization of aliphatic hydrocarbons in deep subsurface soils near the outskirts of Beijing, China.  

PubMed

Thirty-nine deep subsurface soils (150-180 cm depth) near the outskirts of Beijing were investagated. The concentrations including n-alkanes from C13 to C36, pristane and phytane were in the range of 0.60 to 170.10 microg/g, with a median value of 4.26. Carbon preference index values for n-alkanes ranged from 1.08 to 2.98, with a median value of 1.48. The percentage contribution of "wax" n-alkanes was in the range of 6.03%--46.22%. A predominance of odd/even carbon n-alkanes and unresolved complex mixtures with different shapes and ranges were frequently observed. Factor analysis reduced the data set into three principal components and confirming contributions from low (19.58%), medium (20.49%) molecular weight species and long-chain n-alkanes (43.41%), respectively. Molecular biomarkers such as pristane, phytane, hopanes and steranes were detected. Based on the principal component analysis, the concentration profiles and molecular markers, it was found that the aliphatic hydrocarbons were from both biogenic and anthropogenic sources. PMID:16083103

Zhu, You-Feng; Liu, Hui; Xi, Zhi-Qun; Cheng, Hang-Xin; Xu, Xiao-Bai

2005-01-01

107

Subsurface Biofilm Barriers: An Emerging Technology For Containment and Remediation of Contaminated Groundwater  

NASA Astrophysics Data System (ADS)

This paper will summarize emerging biotechnology methods for manipulating microbial processes in the subsurface with the aim of developing improved remediation strategies for dissolved contaminants. Specific topics will include: 1) novel methods for controlling (i.e. enhancing) subsurface transport of injected bacteria for bioaugmentation, and 2) methods for manipulating growth of microbial biofilms to form subsurface biofilm barriers for the containment and bioremediation of contaminant plumes. Starvation of bacteria (for periods of several weeks) has been shown to improve bacterial transport through porous media and thereby provides a useful method for controlling subsurface transport of injected bacteria for bioaugmentation. Injection and resuscitation of starved bacteria has led to successful field testing of a technology which uses microbial biofilms to form subsurface barriers for the containment and bioremediation of contaminant plumes. A field demonstration of biofilm barrier technology was conducted at the MSE facility in Butte, Montana, USA to develop a comprehensive data set for evaluation of biofilm barrier performance. the test bed consisted of a 130 foot wide, 180 foot long, 20 foot deep lysimeter. A flow field was established across the lysimeter by injecting supply water at the up-gradient, while simultaneously pumping from recovery wells located down-gradient. The goal of the field test was to build a denitrifying biofilm barrier which reduces media hydraulic conductivity by at least two orders of magnitude. Maintaining barrier integrity was also a priority. Bacteria capable of producing large quantities of extracellular polymeric substances (eps) were injected into the subsurface, along with an inexpensive nutrient solution. The resulting microbial biomass substantially decreased the free pore space in the formation, thereby reducing the hydraulic conductivity by up to 97%. Because the biofilm inoculum chosen was a denitrifying species the biofilm barrier also represented a potential means for in_situ denitrification. After the barrier was in place a sustained concentration of 100 mg/l nitrate nitrogen, along with a 100 mg/l concentration of conservative (chloride) tracer, was added to the test cell influent over a 6 month period. At the test cell effluent the concentration of chloride gradually increased over the test period while the nitrate concentration remained relative low (less that 10 mg/l), indicating removal of nitrate by the biofilm barrier.

Cunningham, A.

2002-05-01

108

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site  

SciTech Connect

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site's microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog [reg sign] evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog[reg sign] activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

1992-01-01

109

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site  

SciTech Connect

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site`s microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog {reg_sign} evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog{reg_sign} activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

1992-12-31

110

Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation  

NASA Astrophysics Data System (ADS)

A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

Verginelli, Iason; Baciocchi, Renato

2011-11-01

111

Subsurface Contaminant Focus Area: Monitored Natural Attenuation (MNA)--Programmatic, Technical, and Regulatory Issues  

SciTech Connect

Natural attenuation processes are commonly used for remediation of contaminated sites. A variety of natural processes occur without human intervention at all sites to varying rates and degrees of effectiveness to attenuate (decrease) the mass, toxicity, mobility, volume, or concentration of organic and inorganic contaminants in soil, groundwater, and surface water systems. The objective of this review is to identify potential technical investments to be incorporated in the Subsurface Contaminant Focus Area Strategic Plan for monitored natural attenuation. When implemented, the technical investments will help evaluate and implement monitored natural attenuation as a remediation option at DOE sites. The outcome of this review is a set of conclusions and general recommendations regarding research needs, programmatic guidance, and stakeholder issues pertaining to monitored natural attenuation for the DOE complex.

Krupka, Kenneth M.; Martin, Wayne J.

2001-07-23

112

Extraction of hydrocarbon contamination from soils using accelerated solvent extraction.  

PubMed

Accelerated solvent extraction was studied as a method for the extraction of hydrocarbon contamination from wet and dry soils. Temperatures from 125 to 200 degrees C and six different solvents were investigated. Nonpolar solvents could not achieve complete recovery from wet soils at the temperatures studied. Optimum conditions were found to be 175 degrees C with dichloromethane-acetone (1:1, v/v) with 8 min heat-up time and 5 min static time. Quantitative recoveries for diesel range organics (DROs) and waste oil organics (WOOs) were obtained using the optimized conditions. The recovery of DROs and WOOs from three matrices at two concentrations (5 and 2000 mg/kg) averaged 115%. These results show that accelerated solvent extraction can generate results comparable to those obtained using Soxhlet or sonication. PMID:10817360

Richter, B E

2000-04-01

113

Denitrifying Bacteria Isolated from Terrestrial Subsurface Sediments Exposed to Mixed-Waste Contamination? †  

PubMed Central

In terrestrial subsurface environments where nitrate is a critical groundwater contaminant, few cultivated representatives are available to verify the metabolism of organisms that catalyze denitrification. In this study, five species of denitrifying bacteria from three phyla were isolated from subsurface sediments exposed to metal radionuclide and nitrate contamination as part of the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge (OR-IFRC). Isolates belonged to the genera Afipia and Hyphomicrobium (Alphaproteobacteria), Rhodanobacter (Gammaproteobacteria), Intrasporangium (Actinobacteria), and Bacillus (Firmicutes). Isolates from the phylum Proteobacteria were complete denitrifiers, whereas the Gram-positive isolates reduced nitrate to nitrous oxide. rRNA gene analyses coupled with physiological and genomic analyses suggest that bacteria from the genus Rhodanobacter are a diverse population of denitrifiers that are circumneutral to moderately acidophilic, with a high relative abundance in areas of the acidic source zone at the OR-IFRC site. Based on genome analysis, Rhodanobacter species contain two nitrite reductase genes and have not been detected in functional-gene surveys of denitrifying bacteria at the OR-IFRC site. Nitrite and nitrous oxide reductase gene sequences were recovered from the isolates and from the terrestrial subsurface by designing primer sets mined from genomic and metagenomic data and from draft genomes of two of the isolates. We demonstrate that a combination of cultivation and genomic and metagenomic data is essential to the in situ characterization of denitrifiers and that current PCR-based approaches are not suitable for deep coverage of denitrifiers. Our results indicate that the diversity of denitrifiers is significantly underestimated in the terrestrial subsurface.

Green, Stefan J.; Prakash, Om; Gihring, Thomas M.; Akob, Denise M.; Jasrotia, Puja; Jardine, Philip M.; Watson, David B.; Brown, Steven D.; Palumbo, Anthony V.; Kostka, Joel E.

2010-01-01

114

Denitrifying bacteria isolated from terrestrial subsurface sediments exposed to mixed-waste contamination.  

PubMed

In terrestrial subsurface environments where nitrate is a critical groundwater contaminant, few cultivated representatives are available to verify the metabolism of organisms that catalyze denitrification. In this study, five species of denitrifying bacteria from three phyla were isolated from subsurface sediments exposed to metal radionuclide and nitrate contamination as part of the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge (OR-IFRC). Isolates belonged to the genera Afipia and Hyphomicrobium (Alphaproteobacteria), Rhodanobacter (Gammaproteobacteria), Intrasporangium (Actinobacteria), and Bacillus (Firmicutes). Isolates from the phylum Proteobacteria were complete denitrifiers, whereas the Gram-positive isolates reduced nitrate to nitrous oxide. rRNA gene analyses coupled with physiological and genomic analyses suggest that bacteria from the genus Rhodanobacter are a diverse population of denitrifiers that are circumneutral to moderately acidophilic, with a high relative abundance in areas of the acidic source zone at the OR-IFRC site. Based on genome analysis, Rhodanobacter species contain two nitrite reductase genes and have not been detected in functional-gene surveys of denitrifying bacteria at the OR-IFRC site. Nitrite and nitrous oxide reductase gene sequences were recovered from the isolates and from the terrestrial subsurface by designing primer sets mined from genomic and metagenomic data and from draft genomes of two of the isolates. We demonstrate that a combination of cultivation and genomic and metagenomic data is essential to the in situ characterization of denitrifiers and that current PCR-based approaches are not suitable for deep coverage of denitrifiers. Our results indicate that the diversity of denitrifiers is significantly underestimated in the terrestrial subsurface. PMID:20305024

Green, Stefan J; Prakash, Om; Gihring, Thomas M; Akob, Denise M; Jasrotia, Puja; Jardine, Philip M; Watson, David B; Brown, Steven D; Palumbo, Anthony V; Kostka, Joel E

2010-03-19

115

Phytosiderophore Effects on Subsurface Actinide Contaminants: Potential for Phytostabilization and Phytoextraction  

SciTech Connect

This project seeks to understand the influence of phytosiderophore-producing plants (grasses, including crops such as wheat and barley) on the biogeochemistry of actinide and other metal contaminants in the subsurface environment, and to determine the potential of phytosiderophoreproducing plants for phytostabilization and phytoextraction of actinides and some metal soil contaminants. Phytosiderophores are secreted by graminaceous plants such as barley and wheat for the solubilization, mobilization and uptake of Fe and other essential nutrients from soils. The ability for these phytosiderophores to chelate and absorb actinides using the same uptake system, as for Fe is being investigated though characterization of actinide-phytosiderophore complexes (independently of plants), and characterization of plant uptake of such complexes. We may also show possible harm caused by increased chelation of actinides, which may increase actinide mobilization & migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or can be used to develop plant-based soil stabilization/remediation technologies. Such technologies could be the low-cost, low risk solution to many DOE actinide contamination problems.

Ruggiero, Christy

2004-06-01

116

Phytosiderophore Effects on Subsurface Actinide Contaminants: Potential for Phytostabilization and Phytoextraction  

SciTech Connect

This project seeks to understand the influence of phytosiderophore-producing plants (grasses, including crops such as wheat and barley) on the biogeochemistry of actinide and other metal contaminants in the subsurface environment, and to determine the potential of phytosiderophore-producing plants for phytostabilization and phytoextraction of actinides and some metal soil contaminants. Phytosiderophores are secreted by graminaceous plants such as barley and wheat for the solubilization, mobilization and uptake of Fe and other essential nutrients from soils. The ability for these phytosiderophores to chelate and absorb actinides using the same uptake system as for Fe is being investigated though characterization of actinide-phytosiderophore complexes (independently of plants), and characterization of plant uptake of such complexes. We may also show possible harm caused by these plants through increased chelation of actinides that increase in actinide mobilization & migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or can be used to develop plant-based soil stabilization/remediation technologies. Such technologies could be the low-cost, low risk solution to many DOE actinide contamination problems.

Ruggiero, Christy

2005-06-01

117

AN EVALUATION OF HANFORD SITE TANK FARM SUBSURFACE CONTAMINATION FY2007  

SciTech Connect

The Tank Farm Vadose Zone (TFVZ) Project conducts activities to characterize and analyze the long-term environmental and human health impacts from tank waste releases to the vadose zone. The project also implements interim measures to mitigate impacts, and plans the remediation of waste releases from tank farms and associated facilities. The scope of this document is to report data needs that are important to estimating long-term human health and environmental risks. The scope does not include technologies needed to remediate contaminated soils and facilities, technologies needed to close tank farms, or management and regulatory decisions that will impact remediation and closure. This document is an update of ''A Summary and Evaluation of Hanford Site Tank Farm Subsurface Contamination''. That 1998 document summarized knowledge of subsurface contamination beneath the tank farms at the time. It included a preliminary conceptual model for migration of tank wastes through the vadose zone and an assessment of data and analysis gaps needed to update the conceptual model. This document provides a status of the data and analysis gaps previously defined and discussion of the gaps and needs that currently exist to support the stated mission of the TFVZ Project. The first data-gaps document provided the basis for TFVZ Project activities over the previous eight years. Fourteen of the nineteen knowledge gaps identified in the previous document have been investigated to the point that the project defines the current status as acceptable. In the process of filling these gaps, significant accomplishments were made in field work and characterization, laboratory investigations, modeling, and implementation of interim measures. The current data gaps are organized in groups that reflect Components of the tank farm vadose zone conceptual model: inventory, release, recharge, geohydrology, geochemistry, and modeling. The inventory and release components address residual wastes that will remain in the tanks and tank-farm infrastructure after closure and potential losses from leaks during waste retrieval. Recharge addresses the impacts of current conditions in the tank farms (i.e. gravel covers that affect infiltration and recharge) as well as the impacts of surface barriers. The geohydrology and geochemistry components address the extent of the existing subsurface contaminant inventory and drivers and pathways for contaminants to be transported through the vadose zone and groundwater. Geochemistry addresses the mobility of key reactive contaminants such as uranium. Modeling addresses conceptual models and how they are simulated in computers. The data gaps will be used to provide input to planning (including the upcoming C Farm Data Quality Objective meetings scheduled this year).

MANN, F.M.

2007-07-10

118

Persistence of chlorinated hydrocarbon contamination in a California marine ecosystem  

SciTech Connect

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

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

1989-01-01

119

Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel  

SciTech Connect

Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gasoline source area undergoing H2O2 biotreatment. Protozoa were found to occur in elevated numbers in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and below the layer of floating fuel, where uncontaminated groundwater came into contact with fuel. Numbers of protozoa in some contaminated areas equalled or exceeded those found in surface soil. The abundance of protozoa in the biotreatment area was high enough that it would be expected to significantly reduce the bacterial community that was degrading the fuel.

Sinclair, J.L.; Kampbell, D.H.; Cook, M.L.; Wilson, J.T.

1993-01-01

120

Viscosity of high-alcohol content fuel blends with water: subsurface contaminant transport implications.  

PubMed

In the United States, a gasoline fuel blend with alcohol volume fractions of 85% or more is considered (among other fuels) an alternative fuel. As the popularity and usage of high-alcohol content gasoline fuel blends increase, subsurface contamination from these fuels will be of great environmental concern. An important parameter governing the movement of these contaminants in unsaturated porous media is the liquid viscosity. In this study, five sets of experiments are conducted to determine viscosity variations of (a) blends of 15% gasoline with various alcohol mixtures, and (b) mixtures of high-alcohol content gasoline fuel blends with various volume fractions of water. The three alcohols considered in this study are ethanol, methanol, and isopropanol. The viscosity of each liquid mixture is observed using a modified falling-ball viscometer. PMID:18403108

Lee, Kenneth Y

2008-03-04

121

Exposure of Fish Larvae to Hydrocarbon Concentration Fields Generated by Subsurface Blowouts  

Microsoft Academic Search

As the oil activity outside the Norwegian coast moves towards north, the potential for conflict with the fishing industry increases. Reasons for this are the presence of spawning areas for important fish stocks like herring and cod, and also the technical development of subsurface solutions for the oil exploration, increasing the risks for the occurrence of subsurface blowouts.The paper explains

Henrik Rye; Øistein Johansen; Mark Reed; Narve Ekrol; Xiong Deqi

2000-01-01

122

Processes affecting the fate of monoaromatic hydrocarbons in an aquifer contaminated by crude oil  

Microsoft Academic Search

Crude oil spilled from a subsurface pipeline in north-central Minnesota has dissolved in the groundwater, resulting in the formation of a plume of aliphatic, aromatic, and alicyclic hydrocarbons. Comparison of paired oil and groundwater samples collected along the central axis of the residual oil body shows that the trailing edge of the oil is depleted in the more soluble aromatic

Robert P. Eganhouse; Thomas F. Dorsey; Curtis S. Phinney; Alvin M. Westcott

1996-01-01

123

CsI(Tl) with photodiodes for identifying subsurface radionuclide contamination  

SciTech Connect

At the US Department of Energy`s Hanford Site near Richland, Washington, underground radioactive contamination exists as the result of leaks, spills, and intentional disposal of waste products from plutonium-production operations. Characterizing these contaminants in preparation for environmental remediation is a major effort now in progress. In this paper, a cylindrical (15 {times} 61 mm) CsI(Tl) scintillation detector with two side-mounted photodiodes has been developed to collect spectral gamma-ray data in subsurface contaminated formations at the U.S. Department of Energy`s Hanford Site. It operates inside small-diameter, thick-wall steel pipes pushed into the ground to depths up to 20 m by a cone penetrometer. The detector provides a rugged, efficient, magnetic-field-insensitive means for identifying gamma-ray-emitting contaminants (mainly {sup 137}Cs and {sup 60}Co). Mounting two 3 x 30-mm photodiodes end-to-end on a flat area along the detector`s side provides efficient light collection over the length of the detector.

Stromswold, D.C. [Pacific Northwest Lab., Richland, WA (United States); Meisner, J.E.; Nicaise, W.F. [Westinghouse Hanford Co., Richland, WA (United States)

1994-10-01

124

Subsurface contaminant monitoring by laser excitation-emission matrix/cone penetrometer  

NASA Astrophysics Data System (ADS)

We have recently developed instrumentation capable of quickly characterizing or monitoring a site using laser-induced fluorescence (LIF) measurements made through a sapphire window near the tip of a cone penetrometer (CPT) probe as it advances through the subsurface. By incorporating ten laser wavelengths simultaneously and collecting a full three-dimensional fingerprint of the soil sample at a vertical resolution of approximately 2 cm, we have made advances in site characterization using this technique, which enjoys all the advantages of in situ measurements: no exposure to, handling, custody or generation of hazardous waste is involved, and results are available in near real time. This report presents the results of recent work at Otis Air National Guard Base. First, a simple one-dimensional measure of the fluorescence fingerprints was correlated with laboratory results for total petroleum hydrocarbons (TPH), as a potentially convenient way for an operator of our instrument to monitor the results of the LIF measurements in real time, as the probe advances. Second, and more importantly, results are presented to demonstrate the potential of the instrumentation to identify individual target species and to quantify their concentrations approximately. The samples collected on site for conventional laboratory analysis were also measured by LIF and the resulting excitation-emission matrices (EEMs) were analyzed for ten target polycyclic aromatic hydrocarbons (PAHs). Qualitative and semi-quantitative agreement between these two sets of results was obtained. The agreements were extended to the in situ LIF data taken 2 - 3 feet away.

Pepper, Jane W.; Chen, Yu-Min M.; Wright, Andrew O.; Kenny, Jonathan E.

1999-02-01

125

Polycyclic aromatic hydrocarbon contamination in the Italian diet.  

PubMed

The content of total and carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Italian foods was measured. The highest levels of PAHs were found in pizza baked in wood-burning ovens and barbecued beef and pork. Relatively high levels were also found in beet greens and squash, apples and bread, fried beef, pork and rabbit, cured meats and chocolate. Conversely low levels were detected in potatoes and cooked fish, beverages and eggs. The daily intake of total and carcinogenic PAHs also was calculated by multiplying the average consumption of each food by its mean concentration of PAHs. Cereal and milk products, meat, vegetables and fruits were the highest contributors to total PAH intake, since these products are the most important dietary components in Italy. The calculated total dietary PAH intake was 3 micrograms/day per person. The calculated intake of carcinogenic PAHs was 1.4 microgram/day per person. The dietary intake of PAHs was high compared with the calculated respiratory intake (370 ng/day) owing to polluted city air in Italy. These results confirm that food is the major source of human exposure to PAHs, due in particular to the high consumption of contaminated cereal products. PMID:8522036

Lodovici, M; Dolara, P; Casalini, C; Ciappellano, S; Testolin, G

126

STUDIES ON BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SEDIMENTS: BIOAVAILABILITY, BIODEGRADABILITY, AND TOXICITY ISSUES  

EPA Science Inventory

The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes, on which the bioavailability and the toxicity of PAHs often have a significant impact. This research investigated the biode...

127

FINAL REPORT. ENVIRONMENTAL ANALYSIS OF ENDOCRINE DISRUPTING EFFECTS FROM HYDROCARBON CONTAMINANTS IN THE ECOSYSTEM  

EPA Science Inventory

The objective of this project was to determine how environmental contaminants, namely hydrocarbons, act as hormones or anti- hormones in different species present in aquatic ecosystems. The three major components of the research included: 1)a biotechnology based screening system ...

128

Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1998 annual progress report.  

National Technical Information Service (NTIS)

The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones (i.e., environmental hormones) in different species present in aquatic ecosystems. Species of particular focus are thos...

J. McLachlan

1998-01-01

129

Environmental Effects of Dredging. Regulatory Identification of Hydrocarbon Contaminants in Dredged Material.  

National Technical Information Service (NTIS)

This note summarizes the findings of a workshop convened to assist Corps regulators in the evaluation of hydrocarbon contamination in dredged material. The workshop participants suggested a list of 15 compounds to be used in a tiered testing approach. The...

1987-01-01

130

Characterization of Hydrocarbon-Degrading Microbial Populations in Contaminated and Pristine Alpine Soils  

Microsoft Academic Search

Biodegradation of petroleum hydrocarbons in cold environments, including Alpine soils, is a result of indigenous cold-adapted microorganisms able to degrade these contaminants. In the present study, the prevalence of seven genotypes involved in the degradation of n-alkanes (Pseudomonas putida GPo1 alkB; Acinetobacter spp. alkM; Rhodococcus spp. alkB1, and Rhodococcus spp. alkB2), aromatic hydrocarbons (P. putida xylE), and polycyclic aromatic hydrocarbons

R. Margesin; D. Labbe; F. Schinner; C. W. Greer; L. G. Whyte

2003-01-01

131

Subsurface Organics in Aseptic Cores From the MARTE Robotic Drilling Experiment: Ground truth and Contamination Issues  

NASA Astrophysics Data System (ADS)

The subsurface is the key environment for searching for life on planets lacking surface life. This includes the search for past/present life on Mars where possible subsurface life could exist [1]. The Mars-Analog-Rio-Tinto-Experiment (MARTE) performed a simulation of a Mars robotic drilling at the RT Borehole#7 Site ~6.07m, atop a massive-pyrite deposit from the Iberian Pyritic Belt. The RT site is considered an important analog of Sinus Meridiani on Mars, an ideal model analog for a subsurface Martian setting [2], and a relevant example of deep subsurface microbial community including aerobic and anaerobic chemoautotrophs [4-5]. Searching for microbes or bulk organics of biological origin in a subsurface sample from a planet is a key scientific objective of Robotic drilling missions. During the 2005 Field experiment 28 minicores were robotically handled and subsampled for life detection experiments under anti-contamination protocols. Ground truth included visual observation of cores and lab based Elemental and Isotope Ratios Mass Spectrometry analysis (EA-IRMS) of bulk organics in Hematite and Gohetite-rich gossanized tuffs, gossan and clay layers within 0-6m-depth. C-org and N-tot vary up to four orders of magnitude among the litter (~11Wt%, 0-1cm) and the mineralized (~3Wt%, 1-3cm) layers, and the first 6 m-depth (C-org=0.02-0.38Wt%). Overall, the distribution/ preservation of plant and soil-derived organics (d13C-org = 26 per mil to 24 per mil) is ten times higher (C-org=0.33Wt%) that in hematite-poor clays, or where rootlets are present, than in hematite- rich samples (C-org=<0.01Wt%). This is consistent with ATP assay (Lightning-MVP, Biocontrol) for total biomass in subsurface (Borehole#7 ~6.07m, ~avg. 153RLU) vs. surface soil samples (~1,500-81,449RLU) [5]. However, the in-situ ATP assay failed in detecting presence of roots during the in-situ life detection experiment. Furthermore, cm-sized roots were overlooked during remote observations. Finally, ATP Luminometry provided insights for potential contamination from core-handling and environmental dust loadings on cleaned/sterilized control surfaces (e.g., 6,782-36,243RLU/cm2). Cleanliness/sterility can be maintained by applying a simple sterile protocol under field conditions. Science results from this research will support future Astrobiology driven drilling mission planned on Mars. Specifically, ground truth offers relevant insights to assess strengths and limits of in-situ/remote observations vs. laboratory measurements. Results from this experiment will also aid the debate on advantages/ disadvantages of manned vs. robotic drilling missions on Mars or other planets. [1] Boston et al., 1997; [2] http://marte.arc.nasa.gov; [3] Stoker, C., et al., 2006 AbSciCon, [4] Stoker et al., submitted; [5] Bonaccorsi., et al., 2006 AbSciCon.

Bonaccorsi, R.; Stoker, C. R.

2006-12-01

132

Verification and Sensitivity of the Calculational Methods Used in the PATHRAE Code to Predict Subsurface Contaminant Transport for Risk Assessments of SRP (Savannah River Plant) Waste Sites.  

National Technical Information Service (NTIS)

Presented in this report are an independent verification of the subsurface contaminant transport calculations contained in the code and an assessment of the sensitivity of predicted contaminant concentrations to uncertainties in transport parameters. The ...

R. A. Fjeld A. W. Elzerman T. J. Overcamp N. Giannopoulos S. Crider

1986-01-01

133

Organochlorine contaminants in fish and polycyclic aromatic hydrocarbons in sediments from the Barents Sea  

Microsoft Academic Search

Stange, K., and Klungsøyr, J. 1997. Organochlorine contaminants in fish and poly- cyclic aromatic hydrocarbons in sediments from the Barents Sea. - ICES Journal of Marine Science, 54: 318-332. Sediment samples from 140 locations in the Barents Sea were analysed for diaromatic and polyaromatic hydrocarbons (PAHs). The concentrations found were lower than typical levels found at more southern latitudes such

Kari Stange; Jarle Klungsøyr

1997-01-01

134

Petroleum hydrocarbon contamination of ground water in Tiverton, Rhode Island, USA  

NASA Astrophysics Data System (ADS)

Ground water samples from several private wells serving individual homes in Tiverton, Rhode Island were analyzed for petroleum contamination over a 19-month period. The hydrocarbon concentrations initially ranged from 68 to 2350 ppb and then gradually decreased to lower values, ranging from 6 to 1650 ppb, at the end of the study. Samples from the well with the highest hydrocarbon concentration (2350 to 1650 ppb) were investigated in some detail because this was considered a possible source of the petroleum contamination in the area. These studies indicated that most of the hydrocarbons were in the dissolved phase (<1.0 ?m) of the ground water and that it contained large amounts of naphthalene, methyl and dimethyl naphthalenes, and ethyl naphthalenes. In addition, the qualitative distribution of hydrocarbons changed as the concentration decreased over the course of the investigation. There appeared to be preferential loss of the more volatile and easily degraded components relative to the higher molecular weight and more refractory hydrocarbons. Some of the wells at this location are contaminated with at least two different petroleum products, i.e. gasoline and fuel oil. The exact nature and source of the contaminant is not known; it may be spilled or leaking petroleum products, or other materials containing petroleum hydrocarbons (e.g. commercial or industrial cleaning solutions). Based on differences in the qualitative distribution of components, some of the wells contain hydrocarbons that have been environmentally altered or that originate from a source other than the most contaminated well

Zheng, Jinshu; Quinn, James G.

1988-12-01

135

Subsurface microbial community structure correlates with uranium redox phases during in situ field manipulation in a contaminated aquifer  

SciTech Connect

Long-term field manipulation experiments investigating the effects of subsurface redox conditions on the fate and transport of soluble uranium(VI) were conducted over a 3 year period at the Oak Ridge Integrated Field Research Center (OR-IFRC) in Oak Ridge, TN. In the highly contaminated source zone, introduction of ethanol to the subsurface stimulated native denitrifying, sulfate-reducing, iron-reducing and fermentative microorganisms and reduced U to below 0.03 mg/L. Subsequently, oxygen and nitrate were experimentally re-introduced into the subsurface to examine the potential for re-oxidation and re-mobilization of U(IV). Introduction of oxygen or nitrate caused changes in subsurface geochemistry and re-oxidation of U. After reoxidation, the subsurface experienced several months of starvation conditions before ethanol injection was restored to reduce the treatment zone. Subsurface microorganisms were characterized by community fingerprinting, targeted population analyses, and quantitative PCR of key functional groups in 50 samples taken during multiple phases of field manipulation. Statistical analysis confirmed the hypothesis that the microbial community would co-vary with the shifts in the subsurface geochemistry. The level of hydraulic connectivity of sampling wells to the injection well was readily tracked by microbial community analysis. We demonstrate quantitatively that specific populations, especially Desulfosporosinus, are heavily influenced by geochemical conditions and positively correlate with the immobilization of uranium. Following nitrate reoxidation, populations of Fe(II)-oxidizing, nitrate reducing organisms (Thiobacillus) showed an increase in relative abundance.

Kostka, Joel [Florida State University; Green, Stefan [Florida State University, Tallahassee; Wu, Wei-min [Stanford University; Criddle, Craig [Stanford University; Watson, David B [ORNL; Jardine, Philip M [ORNL

2009-07-01

136

Field results from the SCAPS laser-induced fluorescence (LIF) sensor for in-situ subsurface detection of petroleum hydrocarbons  

NASA Astrophysics Data System (ADS)

Laser induced fluorescence (LIF) is a powerful technique for in-situ detection of subsurface contamination due to petroleum products. This paper describes the Site Characterization and Analysis Penetrometer System (SCAPS) LIF sensor which combines an LIF spectroscopic system with a cone penetrometer truck, and presents field results from a recent site characterization of a diesel fuel contaminated site. In addition to the LIF sensor measurements performed at the site, 130 soil samples were collected by hollow stem auger with split-spoon sampling and analyzed by EPA approved laboratory methods to validate the fluorescence sensor. The LIF sensor showed 96% agreement with the laboratory analysis on a detect/non- detect basis. Quantitative comparison of the fluorescence and analytical data show a strong correlation, suggesting that the fluorescence sensor may be capable of quantifying the contaminant concentration given a small number of soil samples for calibration.

Knowles, David S.; Lieberman, Stephen H.

1995-10-01

137

Immobilization or recovery of chlorinated hydrocarbons from contaminated groundwater using clathrate hydrates: A proof-of-concept  

SciTech Connect

The objective of this study was to evaluate whether the formation of solid clathrate hydrates by certain chlorinated hydrocarbon compounds and water would be amenable to in-situ immobilization and ex-situ recovery of these contaminants from groundwater. Using help gases to enhance the formation of the solids, the melting points of clathrate hydrates of CCl-4, 1,1-DCE, PCE, and TCE were measured at 1 atm pressure. CCl-4 hydrates had melting points between 16 and 20 C; 1,1-DCE hydrates had lower melting points of between 11 and 13 C. TCE and PCE hydrates could not be formed unless crystallizing seed material was introduced into the system. Concentrations of CCl-4 and 1,1-DCE in the hydrate phase and the aqueous phase after hydrate formation were determined from experiments in which the chlorinated hydrocarbon compounds existed as a separate dense non-aqueous phase liquid (DNAPL) or as dissolved species in water. Enrichment factors (C{sup H}/C{sup A}, where C is the concentration of the organic in the hydrate[H] and aqueous[A] phase) were between 200 and 500 for 1,1-DCE and CCl-4, respectively. These experiments provided a proof-of-concept suggesting that the in-situ immobilization or ex-situ recovery of some common hydrophobic groundwater contaminants may be possible in a wide range of subsurface environments.

Bontha, Jagannadha R. (BATTELLE (PACIFIC NW LAB)); Kaplan, Daniel I. (BATTELLE (PACIFIC NW LAB))

1998-12-01

138

Immobilization or recovery of chlorinated hydrocarbons from contaminated groundwater using clathrate hydrates: A proof-of-concept  

SciTech Connect

The objective of this study was to evaluate whether the formation of solid clathrate hydrates by certain chlorinated hydrocarbon compounds and water would be amenable to in situ immobilization and ex situ recovery of these contaminants from groundwater. Using help gases to enhance the formation of the solids, the melting points of clathrate hydrates of CCl{sub 4}, 1,1-DCE, PCE, and TCE were measured at 1 atm pressure. CCl{sub 4} hydrates had melting points between 16 and 20 C; 1,1-DCE hydrates had lower melting points of between 11 and 13 C. TCE and PCE hydrates could not be formed unless crystallizing seed material was introduced into the system. Concentrations of CCl{sub 4} and 1,1-DEC in the hydrate phase and the aqueous phase after hydrate formation were determined from experiments in which the chlorinated hydrocarbon compounds existed as a separate dense nonaqueous phase liquid (DNAPL) or as dissolved species in water. Enrichment factors (C{sup H}/C{sup A}, where C is the concentration of the organic in the hydrate [H] and aqueous [A] phase) were between 200 and 500 for 1,1-DCE and CCl{sub 4}, respectively. These experiments provided a proof-of-concept suggesting that the in situ immobilization or ex situ recovery of some common hydrophobic groundwater contaminants may be possible in a wide range of subsurface environments.

Bontha, J.R.; Kaplan, D.I. [Pacific Northwest National Lab., Richland, WA (United States)

1999-04-01

139

Looking For a Needle in the Haystack: Deciphering Indigenous 1.79 km Deep Subsurface Microbial Communities from Drilling Mud Contaminants Using 454 Pyrotag Sequencing  

Microsoft Academic Search

Knowledge of the composition, structure and activity of microbial communities that live in deeply buried sedimentary rocks is fundamental to the future of subsurface biosphere stewardship as it relates to hydrocarbon exploration and extraction, carbon sequestration, gas storage and groundwater management. However, the study of indigenous subsurface microorganisms has been limited by the technical challenges of collecting deep formation water

Y. Dong; I. Cann; R. Mackie; N. Price; T. M. Flynn; R. Sanford; P. Miller; N. Chia; C. G. Kumar; P. Kim; M. Sivaguru; B. W. Fouke

2010-01-01

140

Competitive sorption and multiple-species subsurface transport of nitro-aromatic explosives: implications for their mobility at contaminated sites  

Microsoft Academic Search

Subsurface contamination with nitro-aromatic explosives and related compounds has become a problem at many ordnance and ammunition facilities. Results of our column experiments demonstrate that competition for sorption sites at phyllosilicates may substantially enhance the mobility of individual nitro-aromatic compounds (NACs) in porous media when present in mixtures. Competitive sorption of NACs in mixtures is controlled by two major factors:

CLAUDIA FESCH; STEFAN B. HADERLEIN

141

A STUDY TO DETERMINE THE FEASIBILITY OF USING A GROUND-PENETRATING RADAR FOR MORE EFFECTIVE REMEDIATION OF SUBSURFACE CONTAMINATION  

EPA Science Inventory

A study was conducted (1) to assess the capability of groundpenetrating radar (GPR) to identify natural subsurface features, detect man-made objects burled in the soil, and both detect and define the extent of contaminated soil or ground water due to a toxic spill, and (2) to det...

142

Genome Sequences for Three Denitrifying Bacterial Strains Isolated from a Uranium- and Nitrate-Contaminated Subsurface Environment  

PubMed Central

Genome sequences for three strains of denitrifying bacteria (Alphaproteobacteria—Afipia sp. strain 1NLS2 and Hyphomicrobium denitrificans strain 1NES1; Firmicutes—Bacillus sp. strain 1NLA3E) isolated from the nitrate- and uranium-contaminated subsurface of the Oak Ridge Integrated Field Research Challenge (ORIFRC) site, Oak Ridge Reservation, TN, are reported.

Venkatramanan, Raghavee; Prakash, Om; Woyke, Tanja; Chain, Patrick; Goodwin, Lynne A.; Watson, David; Brooks, Scott; Kostka, Joel E.

2013-01-01

143

Genome sequences for three denitrifying bacterial strains isolated from a uranium- and nitrate-contaminated subsurface environment.  

PubMed

Genome sequences for three strains of denitrifying bacteria (Alphaproteobacteria-Afipia sp. strain 1NLS2 and Hyphomicrobium denitrificans strain 1NES1; Firmicutes-Bacillus sp. strain 1NLA3E) isolated from the nitrate- and uranium-contaminated subsurface of the Oak Ridge Integrated Field Research Challenge (ORIFRC) site, Oak Ridge Reservation, TN, are reported. PMID:23833140

Venkatramanan, Raghavee; Prakash, Om; Woyke, Tanja; Chain, Patrick; Goodwin, Lynne A; Watson, David; Brooks, Scott; Kostka, Joel E; Green, Stefan J

2013-07-05

144

Multiple influences of nitrate on uranium solubility during bioremediation of uranium-contaminated subsurface sediments.  

PubMed

Microbiological reduction of soluble U(VI) to insoluble U(IV) has been proposed as a remediation strategy for uranium-contaminated groundwater. Nitrate is a common co-contaminant with uranium. Nitrate inhibited U(VI) reduction in acetate-amended aquifer sediments collected from a uranium-contaminated site in New Mexico. Once nitrate was depleted, both U(VI) and Fe(III) were reduced concurrently. When nitrate was added to sediments in which U(VI) had been reduced, U(VI) reappeared in solution. Parallel studies with the dissimilatory Fe(III)-, U(VI)- and nitrate-reducing microorganism, Geobacter metallireducens, demonstrated that nitrate inhibited reduction of Fe(III) and U(VI) in cell suspensions of cells that had been grown with nitrate as the electron acceptor, but not in Fe(III)-grown cells. Suspensions of nitrate-grown G. metallireducens oxidized Fe(II) and U(IV) with nitrate as the electron acceptor. U(IV) oxidation was accelerated when Fe(II) was also added, presumably due to the Fe(III) being formed abiotically oxidizing U(IV). These studies demonstrate that although the presence of nitrate is not likely to be an impediment to the bioremediation of uranium contamination with microbial U(VI) reduction, it is necessary to reduce nitrate before U(VI) can be reduced. These results also suggest that anaerobic oxidation of U(IV) to U(VI) with nitrate serving as the electron acceptor may provide a novel strategy for solubilizing and extracting microbial U(IV) precipitates from the subsurface. PMID:12220407

Finneran, Kevin T; Housewright, Meghan E; Lovley, Derek R

2002-09-01

145

Enumeration and Characterization of Iron(III)-Reducing Microbial Communities from Acidic Subsurface Sediments Contaminated with Uranium(VI)  

PubMed Central

Iron(III)-reducing bacteria have been demonstrated to rapidly catalyze the reduction and immobilization of uranium(VI) from contaminated subsurface sediments. Thus, these organisms may aid in the development of bioremediation strategies for uranium contamination, which is prevalent in acidic subsurface sediments at U.S. government facilities. Iron(III)-reducing enrichment cultures were initiated from pristine and contaminated (high in uranium, nitrate; low pH) subsurface sediments at pH 7 and pH 4 to 5. Enumeration of Fe(III)-reducing bacteria yielded cell counts of up to 240 cells ml?1 for the contaminated and background sediments at both pHs with a range of different carbon sources (glycerol, acetate, lactate, and glucose). In enrichments where nitrate contamination was removed from the sediment by washing, MPN counts of Fe(III)-reducing bacteria increased substantially. Sediments of lower pH typically yielded lower counts of Fe(III)-reducing bacteria in lactate- and acetate-amended enrichments, but higher counts were observed when glucose was used as an electron donor in acidic enrichments. Phylogenetic analysis of 16S rRNA gene sequences extracted from the highest positive MPN dilutions revealed that the predominant members of Fe(III)-reducing consortia from background sediments were closely related to members of the Geobacteraceae family, whereas a recently characterized Fe(III) reducer (Anaeromyxobacter sp.) and organisms not previously shown to reduce Fe(III) (Paenibacillus and Brevibacillus spp.) predominated in the Fe(III)-reducing consortia of contaminated sediments. Analysis of enrichment cultures by terminal restriction fragment length polymorphism (T-RFLP) strongly supported the cloning and sequencing results. Dominant members of the Fe(III)-reducing consortia were observed to be stable over several enrichment culture transfers by T-RFLP in conjunction with measurements of Fe(III) reduction activity and carbon substrate utilization. Enrichment cultures from contaminated sites were also shown to rapidly reduce millimolar amounts of U(VI) in comparison to killed controls. With DNA extracted directly from subsurface sediments, quantitative analysis of 16S rRNA gene sequences with MPN-PCR indicated that Geobacteraceae sequences were more abundant in pristine compared to contaminated environments,whereas Anaeromyxobacter sequences were more abundant in contaminated sediments. Thus, results from a combination of cultivation-based and cultivation-independent approaches indicate that the abundance/community composition of Fe(III)-reducing consortia in subsurface sediments is dependent upon geochemical parameters (pH, nitrate concentration) and that microorganisms capable of producing spores (gram positive) or spore-like bodies (Anaeromyxobacter) were representative of acidic subsurface environments.

Petrie, Lainie; North, Nadia N.; Dollhopf, Sherry L.; Balkwill, David L.; Kostka, Joel E.

2003-01-01

146

Geophysical Responses of Hydrocarbon-impacted Zones at the Various Contamination Conditions  

NASA Astrophysics Data System (ADS)

One controlled experiment and two field surveys were conducted to investigate the geoelectrical responses of hydrocarbon-contaminated zones, so called smeared zone, on the geophysical data at the hydrocarbon- contaminated sites with various conditions. One controlled physical model experiment with GPR using fresh gasoline and two different 3-D electrical resistivity investigations at the aged sites. One field site (former military facilities for arms maintenance) was mainly contaminated with lubricating oils and the other (former gas station) was contaminated with gasoline and diesel, respectively. The results from the physical model experiment show that GPR signals were enhanced when LNAPL was present as a residual saturation in the water-saturated system due to less attenuation of the electromagnetic energy through the soil medium of the hydrocarbon-impacted zone (no biodegradation), compared to when the medium was saturated with only water (no hydrocarbon impaction). In the former gas station site, 3-D resistivity results demonstrate that the highly contaminated zones were imaged with low resistivity anomalies since the biodegradation of petroleum hydrocarbons has been undergone for many years, causing the drastic increase in the TDS at the hydrocarbon-impacted zones. Finally, 3-D resistivity data obtained from the former military maintenance site show that the hydrocarbon-contaminated zones show high resistivity anomalies since the hydrocarbons such as lubricating oils at the contaminated soils were not greatly influenced by microbial degradation and has relatively well kept their original physical properties of high electrical resistivity. The results of the study illustrated that the hydrocarbon-impacted zones under various contamination conditions yielded various geophysical responses which include (1) enhanced GPR amplitudes at the fresh LNAPL (Gasoline to middle distillates) spill sites, (2) low electrical resistivity anomalies due to biodegradation at the aged LNAPL- impacted sites, and (3) high electrical resistivity anomalies at the fresh or aged sites contaminated with residual products of crude oils (lubricating oils). The study results also show that the geophysical methods, as a non-invasive sounding technique, can be effectively applied to mapping hydrocarbon-contaminated zones.

Kim, C.; Ko, K.; Son, J.; Kim, J.

2008-12-01

147

Occurrence and Phylogenetic Diversity of Sphingomonas Strains in Soils Contaminated with Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Bacterial strains of the genus Sphingomonas are often isolated from contaminated soils for their ability to use polycyclic aromatic hydrocarbons (PAH) as the sole source of carbon and energy. The direct detection of Sphingomonas strains in contaminated soils, either indigenous or inoculated, is, as such, of interest for bioremediation purposes. In this study, a culture-independent PCR-based detection method using specific

Natalie M. E. J. Leys; Annemie Ryngaert; Leen Bastiaens; Willy Verstraete; Eva M. Top; Dirk Springael

2004-01-01

148

Remediation of hydrocarbon contaminated soils in the Canadian Arctic by landfarming  

Microsoft Academic Search

One of the preferred methods for the remediation of fuel contaminated soil today is landfarming. This is particularly true for remote sites because the method requires minimal equipment and is therefore by far the lowest cost option. The term landfarming generally refers to the process whereby hydrocarbon contaminated soils are spread out in a layer about half a meter thick,

Krysta Paudyn; Allison Rutter; R. Kerry Rowe; John S. Poland

2008-01-01

149

On site bioremediation of hydrocarbon-contaminated Arctic tundra soils in inoculated biopiles  

Microsoft Academic Search

There is a need to develop technology to allow the remediation of soil in polar regions that have been contaminated by hydrocarbon fuel spills. Bioremediation is potentially useful for this purpose, but has not been well demonstrated in polar regions. We investigated biopiles for on-site bioremediation of soil contaminated with Arctic diesel fuel in two independent small-scale field experiments at

W. W. Mohn; C. Z. Radziminski; M.-C. Fortin; K. Reimer

2001-01-01

150

Bioremediation of Poly-Aromatic Hydrocarbon (PAH)Contaminated Soil by Composting  

Microsoft Academic Search

This paper presents a comprehensive and critical review of research on different co-composting approaches to bioremediate hydrocarbon contaminated soil, organisms that have been found to degrade PAHs, and PAH breakdown products. Advantages and limitations of using certain groups of organisms and recommended areas of further research effort are identified. Studies investigating the use of composting techniques to treat contaminated soil

Nadine Loick; Phil J. Hobbs; Mike D. C. Hale; Davey L. Jones

2009-01-01

151

ENVIRONMENTAL ANALYSIS OF ENDOCRINE DISRUPTING EFFECTS FROM HYDROCARBON CONTAMINANTS IN THE ECOSYSTEM  

EPA Science Inventory

The objective of this basic research is to characterize the potential of common hydrocarbon contaminants in ecosystems to act as endocrine disrupters. Although the endocrine disrupting effects of contaminants such as dioxin and PCBs have been well characterized in both animals an...

152

Biodegradation and mineral weathering controls on bulk electrical conductivity in a shallow hydrocarbon contaminated aquifer  

Microsoft Academic Search

Geochemical and stable carbon isotope data from closely spaced vertical intervals in a hydrocarbon-impacted aquifer were used to assess the relationship between biodegradation, mineral weathering, and enhanced bulk conductivity zones. The results show that depth zones of enhanced bulk conductivity in the contaminated aquifer had higher total dissolved solids (TDS) compared to background groundwater. The higher TDS in contaminated groundwater

Eliot A. Atekwana; Estella Atekwana; Franklyn D. Legall; R. V. Krishnamurthy

2005-01-01

153

Denitrifying Bacteria from the Genus Rhodanobacter Dominate Bacterial Communities in the Highly Contaminated Subsurface of a Nuclear Legacy Waste Site  

PubMed Central

The effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of rRNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure and that denitrifying bacteria from the genus Rhodanobacter (class Gammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower-pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as the concentration of nitrogen species, oxygen level, and sampling season, did not appear to strongly influence the distribution of Rhodanobacter bacteria. The results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.

Green, Stefan J.; Prakash, Om; Jasrotia, Puja; Overholt, Will A.; Cardenas, Erick; Hubbard, Daniela; Tiedje, James M.; Watson, David B.; Schadt, Christopher W.; Brooks, Scott C.

2012-01-01

154

Hydrocarbon  

NASA Astrophysics Data System (ADS)

Gas hydrates in permafrost regions are believed to be a significant high-latitude reservoir for hydrocarbon gases, including methane which is a ``greenhouse" gas that may play a significant role in global climate warming. Melting permafrost and associated gas hydrates may contribute hydrocarbon ``greenhouse" gases to the atmosphere, however, little is known about the composition or distribution of the natural gases within permafrost. The primary objective of this presentation is to document and compare the composition and source of the hydrocarbon gases associated with gas hydrates both within and immediately below the zone of permafrost in the Prudhoe Bay-Kuparuk River area of northern Alaska. This study included two major geochemical sampling programs in northern Alaska. In the first program the in-situ composition of the gas within and below the zone of permafrost in the Prudhoe Bay-Kuparuk River area was determined, and in the second, a series of surficial geochemical surveys were made over the area of known surficial gas seepage. Geochemical analyses of drill cuttings collected from 11 petroleum industry wells indicate that methane is the principal hydrocarbon gas in the near-surface (0-1,500 m) strata of the North Slope. Stable methane-carbon isotopic analyses of gaseous drill cuttings from several wells suggest that the methane within the permafrost zone is from both microbial and thermogenic sources. To further examine shallow subsurface gas migration and potential atmospheric methane fluxes from permafrost regions, we analyzed the molecular and methane-carbon isotopic composition of the gas from 105 shallow (<2 m) permafrost cores collected across the Eileen fault zone, an area of known surficial gas seepage and more deeply buried gas hydrate occurrence in the Prudhoe Bay-Kuparuk River area. Analyses of these samples yielded high concentrations of methane and other hydrocarbon gases over the surface trace of the Eileen fault zone. Isotopic analysis of methane in the samples collected near the main fault yielded evidence of thermogenic gas. The data from shallow cores, together with the subsurface geochemical data obtained from northern Alaska, confirm that permafrost does control the distribution, volume, and composition of hydrocarbon gases in Arctic regions. In some areas the hydrocarbon gases in ice-bonded permafrost are exclusively microbial in origin, whereas thermogenic gases only occur beneath the ice-bonded interval. In such cases the base of ice-bonded permafrost may act as a trap for free gas accumulations. In other areas, where unique geologic conditions such as faulting occur, thermogenic gases originating from deep hydrocarbon reservoirs may occur within permafrost even at shallow depths. The abundance of both microbial- and thermogenic-sourced gases and their apparent mobility suggests that the melting of permafrost and associated gas hydrate accumulations could release significant volumes of hydrocarbon ``greenhouse" gases to the atmosphere.

Collett, T. S.; Lorenson, T. D.

2005-12-01

155

Occurrence of atrazine and degradates as contaminants of subsurface drainage and shallow groundwater  

SciTech Connect

Atrazine is a commonly used herbicide in corn (Zea mays L.) growing areas of the USA. Because of its heavy usage, moderate persistence, and mobility in soil, monitoring of atrazine movement under field conditions is essential to assess its potential to contaminate groundwater. Concentrations of atrazine, deisopropylatrazine (DIA), and deethlatraaine (DEA) were measured in subsurface drainage and shallow groundwater beneath continuous, no-till corn. Water samples were collected from the subsurface drain (tile) outlets and suction lysimeters in the growing seasons of 1990 and 1991, and analyzed for atrazine and two principle degradates won solid-phase extraction and HPLC. In 1990, atrazine concentration ranged from 1.3 to 5.1{mu}g L{sup -1} in tile-drain water and from 0.5 to 20.5 {mu}g L{sup -1} in lysimeter water. In general, concentrations of parent and degradates in solution were atrazine > DEA > DIA. Lesser levels of atrazine were measured in 1991 from Plots 2 and 4; however, greater concentrations of atrazine (6.0-8.4 {mu}g L{sup -1}) were measured from plot 5. Throughout the two growing seasons, atrazine concentration in Plot 5 tile-drain water was greater than that of Plots 2 and 4, suggesting a preferential movement of atrazine. Concentrations of DIA and DEA ranged from 0.1 to 2.2 and 0.9 to 3.2 {mu}g L{sup -1} respectively, indicating that the degradation products by themselves or in combination with parent atrazine can exceed the maximum contaminant level (mcl) of 3 {mu}g L{sup -1} even though atrazine by itself may be <3 {mu}g L{sup -1}. The deethylatrazine-to-atrazine ratio (DAR) is an indicator of residence time in soil during transport of atrazine to groundwater. In Plots 2 and 4, DAR values for tile-drain water ranged from 0.43 to 2.70 and 0.50 to 2.66 respectively. By comparison, a DAR of 0.38 to 0.60 was observed in Plot 5, suggesting less residence time in the soil. 38 refs., 5 figs., 4 tabs.

Jayachandran, K.; Steinheimer, T.R.; Moorman, T.B. [National Soil Tilth Lab., Ames, IA (United States)

1994-03-01

156

Hydrocarbon degradation in relation to cell-surface hydrophobicity among bacterial hydrocarbon degraders from petroleum-contaminated Kuwait desert environment  

Microsoft Academic Search

Forty six bacterial isolates able to grow on crude oil were isolated from various hydrocarbon-contaminated sites in Kuwait. The extent of crude oil degradation varied over a wide range (1–87%) among the isolates. Isolates were predominantly Gram-positive bacteria (79% of total isolates) belonging to the genera Bacillus (93%) and Paenibacillus (7%). Among the few Gram-negative isolates were from the genera

Christian O. Obuekwe; Zamya K. Al-Jadi; Esmaeil S. Al-Saleh

2009-01-01

157

Geophysical and geochemical evidence for subsurface hydrocarbon leakage in southern Bering Sea, Alaska  

Microsoft Academic Search

Geophysical and geochemical surveys were conducted in the southern Bering Sea to investigate whether hydrocarbons found in the surficial sediments, particularly in association with certain geophysical events, indicate the presence and nature of more deeply reservoirs oil and gas deposits. Surface sediment samples were obtained at 1000 sites where high-resolution seismic data indicated the presence of gas, active seepage, and\\/or

Michael A. Abrams

1989-01-01

158

Hydrocarbon precombusting catalyst survey and optimization for perfluorocarbon tracer analysis in subsurface tracer applications  

Microsoft Academic Search

The extension of the perfluorocarbon tracer (PFT) technology, as developed for atmospheric dispersion and transport studies to petroleum reservoir characterization studies, required the development of a more robust catalyst to remove analysis interferents caused by the adsorption of 5 liter hydrocarbon reservoir gas samples containing PFT onto carbonaceous adsorbent samplers. Two approaches were studied: (1) replacement of the present internal

G. I. Senum; E. A. Cote; T. W. DOttavio; R. N. Dietz

1989-01-01

159

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

160

Effects of Heterogeneities, Sampling Frequencies, Tools and Methods on Uncertainties in Subsurface Contaminant Concentration Measurements  

NASA Astrophysics Data System (ADS)

Long-term monitoring (LTM) is particularly important for contaminants which are mitigated by natural processes of dilution, dispersion, and degradation. At many sites, LTM can require decades of expensive sampling at tens or even hundreds of existing monitoring wells, resulting in hundreds of thousands, or millions of dollars per year for sampling and data management. Therefore, contaminant sampling tools, methods and frequencies are chosen to minimize waste and data management costs while ensuring a reliable and informative time-history of contaminant measurement for regulatory compliance. The interplay play between cause (i.e. subsurface heterogeneities, sampling techniques, measurement frequencies) and effect (unreliable data and measurements gap) has been overlooked in many field applications which can lead to inconsistencies in time- histories of contaminant samples. In this study we address the relationship between cause and effect for different hydrogeological sampling settings: porous and fractured media. A numerical model has been developed using AMR-FEM to solve the physicochemical processes that take place in the aquifer and the monitoring well. In the latter, the flow is governed by the Navier-Stokes equations while in the former the flow is governed by the diffusivity equation; both are fully coupled to mimic stressed conditions and to assess the effect of dynamic sampling tool on the formation surrounding the monitoring well. First of all, different sampling tools (i.e., Easy Pump, Snapper Grab Sampler) were simulated in a monitoring well screened in different homogeneous layered aquifers to assess their effect on the sampling measurements. Secondly, in order to make the computer runs more CPU efficient the flow in the monitoring well was replaced by its counterpart flow in porous media with infinite permeability and the new model was used to simulate the effect of heterogeneities, sampling depth, sampling tool and sampling frequencies on the uncertainties in the concentration measurements. Finally, the models and results were abstracted using a simple mixed-tank approach to further simplify the models and make them more accessible to field hydrogeologists. During the abstraction process a novel method was developed for mapping streamlines in the fractures as well within the monitoring well to illustrate mixing and mixing zones. Applications will be demonstrated for both sampling in porous and fractured media. 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.

Ezzedine, S. M.; McNab, W. W.

2007-12-01

161

Subsurface screening of petroleum hydrocarbons in soils via laser-induced fluorometry over optical fibers with a cone penetrometer system  

NASA Astrophysics Data System (ADS)

A novel field screening method is described that couples a fiber optic based chemical sensor system to a truck mounted cone penetrometer. The system provides the capability for real- time, in situ measurement of petroleum hydrocarbon contamination and soil type to depths of 50 m. The technique uses a hydraulic ram in a truck with a 20 ton reaction mass to push an instrumented probe into the ground. Fluorescence is excited through a sapphire window in the probe by 337 nm light from a pulsed nitrogen laser. The excitation pulse is transmitted down the probe over a 100 m silica clad silica optical fiber. The resulting fluorescence from aromatic hydrocarbons in the soil is returned to the surface over a second fiber, dispersed with a spectrograph, and quantified with an intensified linear photodiode array. Field test data is presented that demonstrates how the system can be used for rapid three-dimensional delineation of a POL (Petroleum-Oil-Lubricant) contaminant plume at a hazardous waste site. Fluorescent fingerprints from 14 samples of 9 fuel types are used to show how spectral differences can be used for identifying contaminant sources. The effects of volatilization of different fuel types on the measured fluorescent signal are discussed.

Lieberman, Stephen H.; Apitz, Sabine E.; Borbridge, Lisa M.; Theriault, Gregory A.

1993-03-01

162

Effect of salt on aerobic biodegradation of petroleum hydrocarbons in contaminated groundwater  

Microsoft Academic Search

Hydrocarbon-contaminated soil and groundwater at oil and gas production sites may be additionally impacted by salts due to\\u000a release of produced waters. However, little is known about the effect of salt on the in-situ biodegradation of hydrocarbons\\u000a by terrestrial microbes, especially at low temperatures. To study this effect, we prepared a groundwater-soil slurry from\\u000a two sites in Canada: a former

Ania C. Ulrich; Selma E. Guigard; Julia M. Foght; Kathleen M. Semple; Kathryn Pooley; James E. Armstrong; Kevin W. Biggar

2009-01-01

163

Bioremediation of Contaminated Soils: Effects of Bioaugmentation and Biostimulation on Enhancing Biodegradation of Oil Hydrocarbons  

Microsoft Academic Search

\\u000a Contamination of soils with oil hydrocarbons is currently an important worldwide issue. Among all the available remediation\\u000a methods, bioremediation is widely considered to be a cost-effective and environmentally friendly approach. For bioremediation\\u000a to be effective, the overall rate of intrinsic biodegradation and subsequent removal of hydrocarbons must be accelerated,\\u000a which can be done through biostimulation and bioaugmentation. A variety of

Iwona Zawierucha; Grzegorz Malina

164

Amanzi and Akuna: Two New Community Codes for Subsurface Contaminant Flow and Transport  

NASA Astrophysics Data System (ADS)

The Advanced Simulation Capability for Environmental Management (ASCEM) program is developing a modular and extensible open-source set of tools for understanding the fate and transport of contaminants in natural and engineered systems. These tools not only support a fundamental shift toward standardized assessments of performance and risk for the Department of Energy Office of Environmental Management (DOE-EM) cleanup and closure decisions, but establish a modern high-quality code base for a growing interdisciplinary community. Specifically, ASCEM is leveraging advances and expertise from applied mathematics, computer and computational sciences, and the geosciences, in this new development. A toolset named Akuna will provide capabilities for data management, visualization, conceptual model development, uncertainty quantification, parameter estimation, risk analysis, and decision support. Akuna will integrate with Amanzi, a flexible high performance computing simulator, which is designed to leverage the growing parallelism in modern systems. This talk will describe the approach that we have taken to develop this new open-source capability, including issues of intellectual property, licensing, the developers tool chain, and the users tool chain. The modular and extensible design will be discussed, highlighting the potential for collaboration and inclusion of recent modeling and algorithmic advances. In addition, it will discuss the advantages and challenges of relying on an open-source model that leverages a wide variety of open-source efforts from other programs. Results from early prototype development will be presented to highlight the potential of these new tools to contaminated subsurface environments, including calculations for variably saturated flow, advection of non-reactive species and the reactive-transport of 17 different chemical species on both structured and unstructured meshes.

Dixon, P. R.; Moulton, J. D.; Gorton, I.; Meza, J.; Freshley, M.

2011-12-01

165

Measurement of Microbially Induced Transformation of Magnetic Iron Minerals in Soils Allows Localization of Hydrocarbon Contamination  

NASA Astrophysics Data System (ADS)

Soil contamination by crude oil and other hydrocarbons represents a severe environmental problem, but often the location and extent of contamination is not known. Hydrocarbons, or their degradation products, can stimulate iron-metabolizing microorganisms, leading to the formation or dissolution of (magnetic) iron minerals and an associated change of soil magnetic properties. Therefore, the screening of soil magnetic properties has the potential to serve as an efficient and inexpensive tool to localize such contaminations. In order to identify the influence of different biogeochemical factors on the microbially influenced changes of magnetic iron minerals after hydrocarbon contamination, oil spills were simulated in laboratory batch experiments. The parameters tested in these experiments included soils with different bedrocks, type and amount of added hydrocarbon, and microbiological parameters (sterile and autochthonous microorganisms). In order to follow the changes of the soil magnetic properties, the magnetic susceptibility of the samples was measured weekly. First results show that changes in the magnetic mineralogy are caused by microbial activity, as sterile samples showed no changes. In the microbially active set-ups, the magnetic susceptibility increased or decreased up to 10% in comparison to the initial magnetic susceptibility within a few weeks. In one iron-rich soil even a decrease of the magnetic susceptibility of ~40% was observed. Although the amount and type of hydrocarbons did not effect the changes in magnetic susceptibility, DGGE fingerprints revealed that they influenced microbial communities. These results show that the magnetic susceptibility changes in the presence of hydrocarbons and that this change is microbially induced. This suggests that the screening of soil magnetic properties can be applied to localize and assess hydrocarbon contamination. In order to understand the biogeochemical processes better, the change of the iron mineralogy will be followed by Moessbauer spectroscopy in future batch experiments. Furthermore, iron-metabolizing microorganisms are currently isolated and identified.

Kappler, A.; Porsch, K.; Rijal, M.; Appel, E.

2007-12-01

166

Treatment of hydrocarbon contamination under flow through conditions by using magnetite catalyzed chemical oxidation.  

PubMed

Soil pollution by hydrocarbons (aromatic and aliphatic hydrocarbons) is a major environmental issue. Various treatments have been used to remove them from contaminated soils. In our previous studies, the ability of magnetite has been successfully explored to catalyze chemical oxidation for hydrocarbon remediation in batch slurry system. In the present laboratory study, column experiments were performed to evaluate the efficiency of magnetite catalyzed Fenton-like (FL) and activated persulfate (AP) oxidation for hydrocarbon degradation. Flow-through column experiments are intended to provide a better representation of field conditions. Organic extracts isolated from three different soils (an oil-contaminated soil from petrochemical industrial site and two soils polluted by polycyclic aromatic hydrocarbon (PAH) originating from coking plant sites) were spiked on sand. After solvent evaporation, spiked sand was packed in column and was subjected to oxidation using magnetite as catalyst. Oxidant solution was injected at a flow rate of 0.1 mL min(-1) under water-saturated conditions. Organic analyses were performed by GC-mass spectrometry, GC-flame ionization detector, and micro-Fourier transform infrared spectroscopy. Significant abatement of both types of hydrocarbons (60-70 %) was achieved after chemical oxidation (FL and AP) of organic extracts. No significant by-products were formed during oxidation experiment, underscoring the complete degradation of hydrocarbons. No selective degradation was observed for FL with almost similar efficiency towards all hydrocarbons. However, AP showed less reactivity towards higher molecular weight PAHs and aromatic oxygenated compounds. Results of this study demonstrated that magnetite-catalyzed chemical oxidation can effectively degrade both aromatic and aliphatic hydrocarbons (enhanced available contaminants) under flow-through conditions. PMID:22684901

Usman, M; Faure, P; Lorgeoux, C; Ruby, C; Hanna, K

2012-06-09

167

Techniques for Assessing the Performance of In Situ Bioreduction and Immobilization of Metals and Radionuclides in Contaminated Subsurface Environments  

NASA Astrophysics Data System (ADS)

Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this presentation is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed monitoring of coupled hydrological, geochemical/geophysical, and microbial processes. In the following presentation we will (1) discuss contaminant fate and transport problems in humid regimes, (2) efforts to immobilize metals and radionuclides in situ via bioremediation, and (3) state-of -the-art techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides. These included (a) in situ solution and solid phase monitoring, (b) in situ and laboratory microbial community analysis, (c) noninvasive geophysical methods, and (d) solid phase speciation via high resolution spectroscopy.

Watson, D. B.; Jardine, P. M.

2005-05-01

168

Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments  

SciTech Connect

Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed monitoring of coupled hydrological, geochemical/geophysical, and microbial processes. In the following manuscript we will (1) discuss contaminant fate and transport problems in humid regimes, (2) efforts to immobilize metals and radionuclides in situ via bioremediation, and (3) state-of-the-art techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides. These included (a) in situ solution and solid phase monitoring, (b) in situ and laboratory microbial community analysis, (c) noninvasive geophysical methods, and (d) solid phase speciation via high resolution spectroscopy.

Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

2004-11-14

169

Venting Remediation of Unsaturated Soil Contaminated by Diesel Hydrocarbon  

Microsoft Academic Search

The petroleum pollution was one of the main environmental problems to the soil and groundwater safety. Efficient remediation of contaminant soil has significance to the organic pollution control of soil and groundwater. The remediation efficiency of pulse soil venting with low air flow to the soil contaminated with diesel fuel for a long time was studied through indoor sandbox test.

Wei He; Honghan Chen; Fei Liu; Jinfeng Yang; Yanying Sun

2009-01-01

170

Polycyclic aromatic hydrocarbons in Estonian soil: contamination and profiles  

Microsoft Academic Search

The distribution and accumulation of polycyclic aromatic hydrocarbons (PAH) in soil as well as PAH profiles have been investigated in areas with different anthropogenic pollution such as the city of Tallinn, the towns of Pärnu and Kohtla-Järve and some rural areas. PAH were identified in 147 soil samples (0–10 cm upper layer) collected in September 1996. The typical ? PAH

M Trapido

1999-01-01

171

Hydrocarbon solvent recovery in the presence of resin contaminants  

Microsoft Academic Search

A system was developed to recover acetone from an air stream in which epoxy resin particles were suspended. This recovery problem is encountered in the manufacture of fiber glass reinforced plastic pipe. It is representative of numerous other industrial situations which require the recovery of hydrocarbon solvents from a gaseous stream containing resin particles in order to eliminate atmospheric pollution.

Turpin

1984-01-01

172

Hydrocarbon Contamination Decreases Mating Success in a Marine Planktonic Copepod  

Microsoft Academic Search

The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil

Laurent Seuront

2011-01-01

173

Polycyclic aromatic hydrocarbon contamination in the Italian diet  

Microsoft Academic Search

The content of total and carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Italian foods was measured. The highest levels of PAHs were found in pizza baked in wood?burning ovens and barbecued beef and pork. Relatively high levels were also found in beet greens and squash, apples and bread, fried beef, pork and rabbit, cured meats and chocolate. Conversely low levels were

M. Lodovici; P. Dolara; C. Casalini; S. Ciappellano; G. Testolin

1995-01-01

174

Acidobacteria Phylum Sequences in Uranium-Contaminated Subsurface Sediments Greatly Expand the Known Diversity within the Phylum  

Microsoft Academic Search

The abundance and composition of bacteria of the phylum Acidobacteria were surveyed in subsurface sediments from uranium-contaminated sites using amplification of 16S rRNA genes followed by clone\\/sequence analysis. Analysis of sequences from this study and public databases produced a revised and greatly expanded phylogeny of the Acidobacteria phylum consisting of 26 subgroups. Bacteria in the Acidobacteria phylum have been detected

Susan M. Barns; Elizabeth C. Cain; Leslie Sommerville; Cheryl R. Kuske

2007-01-01

175

Numerical Assessment of Indoor Air Exposure Risk from Subsurface NAPL Contamination under Hydrologic Uncertainties  

NASA Astrophysics Data System (ADS)

Understanding the risk of indoor air exposure to residual contaminants in the subsurface following the redevelopment of contaminated land redevelopment project is a central issue at many brownfield sites. In this study, we examine various mechanisms controlling vapor phase intrusion into the indoor air of a typical residential dwelling from a NAPL source located below the water table, and consequently assess the indoor air exposure risk under multiple hydrologic uncertainties. For this purpose, a multi-phase multi-component numerical model, CompFlow Bio is used to simulate the evolution of a TCE source zone and dissolved plume in a variably saturated heterogeneous aquifer, along with the transport of dissolved TCE upwards through the capillary fringe with subsequent migration of TCE vapors in the vadose zone subject to barometric pressure fluctuations. The TCE vapors then enter the basement of the residential dwelling through a crack in the foundation slab, driven by a slight vacuum within the basement relative to the ambient atmosphere as well as the barometric pressure fluctuations. Hydrologic uncertainties affecting the indoor air concentration of TCE include the vacuum in the basement, the aperture of the crack in the foundation slab, the heterogeneous permeability field, the thickness of the capillary fringe, barometric fluctuations, recharge rates and the location of the TCE source zone. CompFlow Bio is then used to determine the future concentration of TCE into the basement as a consequence of imperfect knowledge in the various hydrologic parameters, and to evaluate the effectiveness of alternative remedial and foundation design options to minimize the exposure risk to the indoor air conditional upon the available data collected at the site. The outcome of this approach is two-fold. First, the owner of the site can reasonably evaluate the future indoor air exposure risk following the redevelopment of a formerly contaminated site following remediation activities. Second, the owner/developer of the site can then effectively price the risk that some residential dwellings will exceed an indoor air exposure regulatory limit assuming that the owner/developer of the site takes immediate actions to repurchase the residential dwelling where the regulatory limit was exceeded. Consequently, appropriate financial products (such as insurance or building a contingency fund) can be developed to enable the owner/developer to effectively hedge their risk and ensure solvency.

Unger, A.; Yu, S.

2007-12-01

176

Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream  

DOEpatents

This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced.

Kansa, Edward J. (Livermore, CA); Anderson, Brian L. (Lodi, CA); Wijesinghe, Ananda M. (Tracy, CA); Viani, Brian E. (Oakland, CA)

1999-01-01

177

Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream  

DOEpatents

This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced. 3 figs.

Kansa, E.J.; Anderson, B.L.; Wijesinghe, A.M.; Viani, B.E.

1999-05-25

178

Effects of breathing air containing contaminants such as CO/sub 2/, CO and hydrocarbons at 1 and 5 atmospheres  

SciTech Connect

The neural and behavioral effects of air contaminants such as CO/sub 2/, CO, and hydrocarbons are reviewed. Each contaminant or contaminant class is reviewed separately and then an attempt is made to estimate effects of combinations of contaminants. The effects are reviewed for both normobaric and hyperbaric conditions. Rough dose-effects curves were constructed from data found in the literature.

Benignus, V.A.

1987-11-01

179

Response of a benthic food web to hydrocarbon contamination  

Microsoft Academic Search

Direct and indirect effects of diesel-contaminated sediment on microalgae, meiofauna, and meiofauna-microalgae trophic interactions were examined in a microcosm study of the sediment community from a Spartina aZterniJora salt marsh. Microcosms of natural sediment were given small daily doses of contaminated sediment over a 28-d period, creating low-, medium-, and high-diesel treatment concentrations of -0.5, 5.5, and 55 ppm PAH,

Kevin R. Carman; John W. Fleeger; Steven M. Pomarico

180

Horizontal Gene Transfer of PIB-Type ATPases among Bacteria Isolated from Radionuclide- and Metal-Contaminated Subsurface Soils  

PubMed Central

Aerobic heterotrophs were isolated from subsurface soil samples obtained from the U.S. Department of Energy's (DOE) Field Research Center (FRC) located at Oak Ridge, Tenn. The FRC represents a unique, extreme environment consisting of highly acidic soils with cooccurring heavy metals, radionuclides, and high nitrate concentrations. Four hundred isolates obtained from contaminated soil were assayed for heavy metal resistance, and a smaller subset was assayed for tolerance to uranium. The vast majority of the isolates were gram-positive bacteria and belonged to the high-G+C- and low-G+C-content genera Arthrobacter and Bacillus, respectively. Genomic DNA from a randomly chosen subset of 50 Pb-resistant (Pbr) isolates was amplified with PCR primers specific for PIB-type ATPases (i.e., pbrA/cadA/zntA). A total of 10 pbrA/cadA/zntA loci exhibited evidence of acquisition by horizontal gene transfer. A remarkable dissemination of the horizontally acquired PIB-type ATPases was supported by unusual DNA base compositions and phylogenetic incongruence. Numerous Pbr PIB-type ATPase-positive FRC isolates belonging to the genus Arthrobacter tolerated toxic concentrations of soluble U(VI) (UO22+) at pH 4. These unrelated, yet synergistic, physiological traits observed in Arthrobacter isolates residing in the contaminated FRC subsurface may contribute to the survival of the organisms in such an extreme environment. This study is, to the best of our knowledge, the first study to report broad horizontal transfer of PIB-type ATPases in contaminated subsurface soils and is among the first studies to report uranium tolerance of aerobic heterotrophs obtained from the acidic subsurface at the DOE FRC.

Martinez, Robert J.; Wang, Yanling; Raimondo, Melanie A.; Coombs, Jonna M.; Barkay, Tamar; Sobecky, Patricia A.

2006-01-01

181

Mobilization of trace elements in aquifers by biodegradation of hydrocarbon contaminants. Master Thesis  

Microsoft Academic Search

This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals

Kearney

1997-01-01

182

BIOGEOCHEMICAL EVIDENCE FOR MICROBIAL COMMUNITY CHANGE IN A JET FUEL HYDROCARBONS-CONTAMINATED AQUIFER  

EPA Science Inventory

A glacio-fluvial aquifer located at Wurtsmith Air Force Base, Michigan, had been contaminated with JP-4 fuel hydrocarbons released after the crash of a tanker aircraft in October of 1988 Microbial biomass and community structure, associated with the aquifer sediments, were chara...

183

Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer  

Microsoft Academic Search

We characterized bacteria from contaminated aquifers for their ability to utilize aromatic hydrocarbons under hypoxic (oxygen-limiting) conditions (initial dissolved oxygen concentration about 2 mg\\/l) with nitrate as an alternate electron acceptor. This is relevant to current intense efforts to establish favorable conditions forin situ bioremediation. Using samples of granular activated carbon slurries from an operating groundwater treatment system, we isolated

Mark D. Mikesell; Jerome J. Kukor; Ronald H. Olsen

1993-01-01

184

USE OF CRUDE COFFEE GRAIN FOR TREATMENT OF PETROLEUM HYDROCARBON-CONTAMINATED SOIL  

Microsoft Academic Search

The environmental pollution caused by toxic compounds is a global problem. In Mexico, a number of diverse technological options in biological processes have been tested for the restoration of sites contami- nated with hydrocarbons. One of these processes is the addition of organic bulking agents to improve the characteristics of soil and to enhance the removal of the contaminant. The

G. A. Roldán-Martín; R. Rodríguez-Vázquez

185

STABLE CARBON ISOTOPE BIOGEOCHEMISTRY OF A SHALLOW SAND AQUIFER CONTAMINATED WITH FUEL HYDROCARBONS  

EPA Science Inventory

Ground-water chemistry and the stable C isotope composition ( 13CDIC) of dissolved C (DIC) were measured in a sand aquifer contaminated with JP-4 fuel hydrocarbons. Results show that ground water in the upgradient zone was characterized by DIC content of 14-20 mg C/L and 13CDIC...

186

Microbial contamination of stored hydrocarbon fuels and its control  

Microsoft Academic Search

The major microbial problem in the petroleum refining industry is contamination of stored products, which can lead to loss of product quality, formation of sludge and deterioration of pipework and storage tanks, both in the refinery and at the end-user. Three major classes of fuel are discussed in this article - gasoline, aviation kerosene and diesel, corresponding to increasingly heavy

Christine C. Gaylarde; Fátima M. Bento; Joan Kelley

1999-01-01

187

Mobile hydrocarbon microspheres from >2-billion-year-old carbon-bearing seams in the South African deep subsurface.  

PubMed

By ~2.9 Ga, the time of the deposition of the Witwatersrand Supergroup, life is believed to have been well established on Earth. Carbon remnants of the microbial biosphere from this time period are evident in sediments from around the world. In the Witwatersrand Supergroup, the carbonaceous material is often concentrated in seams, closely associated with the gold deposits and may have been a mobile phase 2 billion years ago. Whereas today the carbon in the Witwatersrand Supergroup is presumed to be immobile, hollow hydrocarbon spheres ranging in size from <1 ?m to >50 ?m were discovered emanating from a borehole drilled through the carbon-bearing seams suggesting that a portion of the carbon may still be mobile in the deep subsurface. ToF-SIMS and STXM analyses revealed that these spheres contain a suite of alkane, alkenes, and aromatic compounds consistent with the described organic-rich carbon seams within the Witwatersrand Supergroup's auriferous reef horizons. Analysis by electron microscopy and ToF-SIMS, however, revealed that these spheres, although most likely composed of biogenic carbon and resembling biological organisms, do not retain any true structural, that is, fossil, information and were formed by an abiogenic process. PMID:22901282

Wanger, G; Moser, D; Hay, M; Myneni, S; Onstott, T C; Southam, G

2012-08-20

188

Bioremediation of soils contaminated with petroleum hydrocarbons using bioslurry reactors. Final report  

SciTech Connect

The Department of Defense has over 12,000 sites contaminated from military activities. This report presents data from two bench-scale and two pilot-scale studies that evaluated the suitability of the bioslurry process to bioremediate soils contaminated by petroleum hydrocarbons. Soils from two contaminated sites were studied. The first soil contained polycyclic aromatic hydrocarbons (PAHs), BTEX (benzene, toluene, ethylbenzene, and xylene) compounds, ketones, and chlorinated ethanes; the second soil contained gasoline and associated compounds. Conceptual designs and costs of bioslurry processes for field applications are also presented. Bench-scale studies were performed in 5-L batch reactors, equipped with aeration and mixing equipment. Various nutrient amendments, surfactants, and selected microbial consortia were evaluated during the bench-scale studies. Several reactors were also operated using only native microbes.

Banerji, S.K.; Zappi, M.E.; Teeter, C.L.; Gunnison, D.; Cullinane, M.J.

1995-10-01

189

Ambivalent role of water in thermodesorption of hydrocarbons from contaminated soil.  

PubMed

Thermodesorption studies with soil samples from a former filling station for light crude oil contaminated with mineral oil hydrocarbons (mainly benzene, toluene, ethylbenzene, xylenes, naphthalene, alkylnaphthalenes, and C(10) to C(14) alkanes) have revealed an ambivalent influence of water on desorption rates. Particularly, the influences of soil moisture content, humidity of the purge gas, temperature, and content of soil organic matter (SOM) were studied. At low temperature, purge gas humidity strongly affected the mobility of hydrocarbons in the soil organic matter (SOM) leading to an enhanced release of contaminants at higher moisture contents. Heating resulted in a decrease of thermodesorption when connected with desiccation of soil, in spite of the strong temperature impact on the vapor pressure of contaminants. At high water content of the SOM, the transfer of the pollutant molecules into the gas phase was found to be markedly hindered by the formation of water films or pore-filling by bulk water, both acting as diffusion barriers. PMID:21133366

Roland, Ulf; Holzer, Frank; Kopinke, Frank-Dieter

2010-12-06

190

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

191

Biomarkers for Great Lakes priority contaminants: halogenated aromatic hydrocarbons.  

PubMed Central

One of the major goals of the Great Lakes Action Plan is to actively accumulate and assess toxicological information on persistent toxic substances found in the Great Lakes basin. As part of Health Canada's commitment to this plan, a review of biomarkers for the environmental contaminants polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs) was conducted. In general, while food consumption was identified as the major source of human exposure to both contaminant groups, certain commodities, such as fish, milk and dairy products, and meat, were found to predominate. Due to the ubiquitous nature of these environmental contaminants and their propensity to bioaccumulate, all humans will have detectable body burdens, which in certain cases can be positively associated with the consumption of particular foods (i.e., PCBs and freshwater fish from the Great Lakes). When dealing with environmental exposure only, relating specific effect biomarkers to contaminant exposure or tissue levels was difficult, due in part to the complex nature of the exposure and the nonspecific nature of the effect. For PCBs, the most likely biomarkers of effect included some form of alteration in lipid metabolism (serum triglyceride/cholesterol levels) and elevation of hepatic-related enzymes, aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT). Cross-species extrapolation also indicates the potential for neurotoxicologic effects to occur in humans. For PCDDs/PCDFs, dermatologic lesions (chloracne) and indications of hepatic enzyme induction have been documented, but primarily due to occupational or high acute accidental exposures. Recent evidence suggests that neonates may represent a potential at-risk population due to relatively high exposure to PCDDs/PCDFs, as with PCBs, during breast feeding as compared to standard adult dietary intake. Future areas of potential benefit for biomarker development include immunologic and endocrine effects, primarily based on biologic plausibility from experimental animal research.

Feeley, M M

1995-01-01

192

Prediction of ecotoxicity of hydrocarbon-contaminated soils using physicochemical parameters  

SciTech Connect

The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.

Wong, D.C.L.; Chai, E.Y.; Chu, K.K.; Dorn, P.B.

1999-11-01

193

Microbial communities along biogeochemical gradients in a hydrocarbon-contaminated aquifer.  

PubMed

Micro-organisms are known to degrade a wide range of toxic substances. How the environment shapes microbial communities in polluted ecosystems and thus influences degradation capabilities is not yet fully understood. In this study, we investigated microbial communities in a highly complex environment: the capillary fringe and subjacent sediments in a hydrocarbon-contaminated aquifer. Sixty sediment sections were analysed using terminal restriction fragment length polymorphism (T-RFLP) fingerprinting, cloning and sequencing of bacterial and archaeal 16S rRNA genes, complemented by chemical analyses of petroleum hydrocarbons, methane, oxygen and alternative terminal electron acceptors. Multivariate statistics revealed concentrations of contaminants and the position of the water table as significant factors shaping the microbial community composition. Micro-organisms with highest T-RFLP abundances were related to sulphate reducers belonging to the genus Desulfosporosinus, fermenting bacteria of the genera Sedimentibacter and Smithella, and aerobic hydrocarbon degraders of the genus Acidovorax. Furthermore, the acetoclastic methanogens Methanosaeta, and hydrogenotrophic methanogens Methanocella and Methanoregula were detected. Whereas sulphate and sulphate reducers prevail at the contamination source, the detection of methane, fermenting bacteria and methanogenic archaea further downstream points towards syntrophic hydrocarbon degradation. PMID:23809669

Tischer, Karolin; Kleinsteuber, Sabine; Schleinitz, Kathleen M; Fetzer, Ingo; Spott, Oliver; Stange, Florian; Lohse, Ute; Franz, Janett; Neumann, Franziska; Gerling, Sarah; Schmidt, Christian; Hasselwander, Eyk; Harms, Hauke; Wendeberg, Annelie

2013-07-01

194

Mobilization of trace elements in aquifers by biodegradation of hydrocarbon contaminants. Master Thesis  

SciTech Connect

This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals are present at petroleum hydrocarbon sites where metals would not generally be expected. Of the metals with drinking water maximum contaminant levels (MCLs), mercury and silver were detected the least frequently. Barium and copper were detected at the sites, but fewer than 2.5 percent of the samples exceeded their MCLs. All other metals exceeded their MCLs in at least 2.5 percent of the samples, with antimony and lead exceeding their MCLs in 19 percent and 10 percent of samples, respectively. Higher concentrations of barium and manganese were most strongly correlated with petroleum hydrocarbon contamination, and relatively strong correlations also existed for aluminum, arsenic, iron, and lead. Major cations such as calcium, magnesium, sodium and potassium were least affected by petroleum hydrocarbons concentrations.

Kearney, S.L.

1997-12-01

195

The Subsurface Contaminant Focus Area (SCFA) Plans Strategic Objectives Through Roadmaps  

SciTech Connect

The Subsurface Contaminant Focus Area (SCFA) has historically worked with individual Department of Energy (DOE) sites to identify needs and develop technologies to solve those with the most immediate and high payoff. This approach has led to successful deployments and strong technical assistance. The current DOE site technical needs collection method yielded over 300 needs in fiscal year (FY) 2001 and requires a means to help focus development. With a desire to improve program support, SCFA has defined specific strategic objectives and wishes to perform specific development to accomplish these objectives. The SCFA has developed this improved approach for technical and strategic management by identifying and describing the site needs using a smaller number of technical targets, which individually work to solve many of the site needs. The targets have elements of near-term and long-term thrusts that can be used to balance the investments for science and applied R&D. SCFA is also developing ''mini roadmaps'' for each technical target to outline specific performance requirements, where improvements are needed, when the improvements are needed, and the significance to the DOE programs. The technical targets were evaluated for complexity and potential benefits to prioritize the order that they would be roadmapped. Four technical targets were identified as the first candidates for roadmapping and will be completed in the January-March 2002 time. The technical community within SCFA will develop the potential targeted improvements and the end-users will help describe the potential impact of these improvements to their programs. The end product from these ''mini roadmaps'' will include the target's technical objectives with a definition of the performance objectives and potential impacts. This paper will summarize the progress to date in roadmapping the SCFA technical targets selected to be completed first. The first four roadmaps will be used to test how the mini-roadmapping process can strengthen the strategic planning and portfolio management within the SCFA. The paper will focus on the identification and discussion of the mini-roadmapping process adaptations required to roadmap program objectives within a focus area where broad and crosscutting development is needed and customers are unique and spread out. The timely lessons learned and insights will be valuable to other programs desiring to roadmap large amounts of workscope but unsure how to successfully complete it.

Murphy, J. A.

2002-02-28

196

Key players and team play: anaerobic microbial communities in hydrocarbon-contaminated aquifers.  

PubMed

Biodegradation of anthropogenic pollutants in shallow aquifers is an important microbial ecosystem service which is mainly brought about by indigenous anaerobic microorganisms. For the management of contaminated sites, risk assessment and control of natural attenuation, the assessment of in situ biodegradation and the underlying microbial processes is essential. The development of novel molecular methods, "omics" approaches, and high-throughput techniques has revealed new insight into complex microbial communities and their functions in anoxic environmental systems. This review summarizes recent advances in the application of molecular methods to study anaerobic microbial communities in contaminated terrestrial subsurface ecosystems. We focus on current approaches to analyze composition, dynamics, and functional diversity of subsurface communities, to link identity to activity and metabolic function, and to identify the ecophysiological role of not yet cultured microbes and syntrophic consortia. We discuss recent molecular surveys of contaminated sites from an ecological viewpoint regarding degrader ecotypes, abiotic factors shaping anaerobic communities, and biotic interactions underpinning the importance of microbial cooperation for microbial ecosystem services such as contaminant degradation. PMID:22476263

Kleinsteuber, Sabine; Schleinitz, Kathleen M; Vogt, Carsten

2012-04-04

197

Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill  

Microsoft Academic Search

The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10m×10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days

L Ke; Teresa W. Y Wong; Y. S Wong; Nora F. Y Tam

2002-01-01

198

Metabolic and bacterial diversity in soils historically contaminated by heavy metals and hydrocarbons.  

PubMed

The aim of this study was to characterize soils contaminated by different levels of heavy metals and hydrocarbons (Madonna Dell'Acqua, Pisa, Italy). The soils were chemically and biochemically analysed by measuring the standard chemical properties and some enzyme activities related to microbial activity (dehydrogenase activity) and the soil carbon cycle (total and extracellular beta-glucosidase activities). The metabolic capacities of soil microorganisms to degrade hydrocarbons through catechol 2,3-dioxygenase were also described. The microbial diversity of contaminated and uncontaminated soils was estimated by denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA sequences. The PCR/single-strand conformation polymorphism (PCR/SSCP) method was used to estimate the genetic diversity of PAH-degrading genes in both contaminated and uncontaminated soils. A greater bacterial diversity and lower catechol 2,3-dioxygenase activity was detected in unpolluted soils. The complexity of the microbial community (Shannon and Simpson indices) as well as the dehydrogenase soil activity negatively correlated with contamination levels. The greatest PAH-degrading gene diversity and the most intense catechol 2,3-dioxygenase activity were found in the soils with the highest levels of hydrocarbons. Heavy metals and hydrocarbon pollution has caused a genetic and metabolic alteration in microbial communities, corresponding to a reduction in microbial activity. A multi-technique approach combining traditional biochemical methods with molecular-based techniques, along with some methodological improvements, may represent an important tool to expand our knowledge of the role of microbial diversity in contaminated soil. PMID:18974897

Vivas, Astrid; Moreno, Beatriz; del Val, Coral; Macci, Cristina; Masciandaro, Grazia; Benitez, Emilio

2008-10-03

199

Characterizing marine hydrocarbons with in-situ mass spectrometry  

Microsoft Academic Search

Identification and tracking of hydrocarbons in the marine environment is challenging. State of the art systems typically rely on surface slicks to identify hydrocarbon contamination such as oil spills. Subsurface detection remains challenging. This paper describes the TETHYS in-situ mass spectrometer and results of real-world deployments. TETHYS is a small, self contained mass spectrometer capable of operation to 5000 meters

R. Camilli; A. Duryea

2007-01-01

200

Relative hopane content confirming the mineral origin of hydrocarbons contaminating foods and human milk.  

PubMed

Hopanes, triterpenoid hydrocarbons formed under geological conditions, were analysed to confirm the mineral origin of the unresolved complex mixtures of hydrocarbons observed in the gas chromatography with flame ionization detection chromatograms of human milk and certain foodstuffs. The 'relative hopane content' (RHC) is introduced, i.e. it is the area ratio of the sum of the hopanes and the paraffins in the same segment of the chromatogram. The RHC in various mineral oil products (motor oils, hydraulic oils, lubricating oils, Vaseline) was 3.4%, with a relative standard deviation of 19%. The RHC determined in samples of vegetable oils, mussels and clams as well as of human milk containing an unresolved complex mixture of hydrocarbons was in the same range, confirming that these samples were contaminated by mineral oil material. PMID:15666983

Populin, T; Biedermann, M; Grob, K; Moret, S; Conte, L

2004-09-01

201

Bioremediation of contaminated groundwater  

DOEpatents

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

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

1994-01-01

202

Selection of Biosurfactan/Bioemulsifier-Producing Bacteria From Hydrocarbon-Contaminated Soil  

PubMed Central

Petroleum-derived hydrocarbons are among the most persistent soil contaminants, and some hydrocarbon-degrading microorganisms can produce biosurfactants to increase bioavailability and degradation. The aim of this work was to identify biosurfactant-producing bacterial strains isolated from hydrocarbon-contaminated sites, and to evaluate their biosurfactant properties. The drop-collapse method and minimal agar added with a layer of combustoleo were used for screening, and positive strains were grown in liquid medium, and surface tension and emulsification index were determined in cell-free supernantant and cell suspension. A total of 324 bacterial strains were tested, and 17 were positive for the drop-collapse and hydrocarbon-layer agar methods. Most of the strains were Pseudomonas, except for three strains (Acinetobacter, Bacillus, Rhodococcus). Surface tension was similar in cell-free and cell suspension measurements, with values in the range of 58 to 26 (mN/m), and all formed stable emulsions with motor oil (76-93% E24). Considering the variety of molecular structures among microbial biosurfactants, they have different chemical properties that can be exploited commercially, for applications as diverse as bioremediation or degradable detergents.

Viramontes-Ramos, Sabina; Cristina Portillo-Ruiz, Martha; Ballinas-Casarrubias, Maria de Lourdes; Torres-Munoz, Jose Vinicio; Rivera-Chavira, Blanca Estela; Nevarez-Moorillon, Guadalupe Virginia

2010-01-01

203

Detection of heavy metal and hydrocarbon contamination using a miniature resistivity probe.  

PubMed

The usefulness of the electrical resistivity method for characterization of contaminated sites has been studied in many ways. The most commonly used device is a cone penetrometer that utilizes two or four electrodes to measure electrical resistivity (or conductivity) during a cone penetration test (CPT) along a vertical or horizontal alignment. This paper introduces a new miniature resistivity probe (MRP) that can potentially be deployed from a sampling platform to detect contaminant plumes prior to collecting soil samples. Following bench-scale tests aimed at quantifying the sensitivity of the MRP to various operating and environmental parameters, the response of the MRP in sandy soil containing various concentrations of tour heavy metals (Cu, Zn, Pb and Ni) and two hydrocarbons (phenol and gasoline) is evaluated. The test data revealed that the MRP has the potential to serve as an indexing tool for rapidly delineating contaminant plumes where heavy metals are present. The results for hydrocarbons were less conclusive, ranging from moderate ability to differentiate contaminated and non-contaminated soils for phenol to poor differentiation ability for gasoline. PMID:17624110

Ahn, T; Allouche, E N; Yanful, E K

2007-06-01

204

Iron reduction in the sediments of a hydrocarbon-contaminated aquifer  

USGS Publications Warehouse

Sediments sampled at a hydrocarbon-contaminated, glacial-outwash, sandy aquifer near Bemidji, Minnesota, were analyzed for sediment-associated Fe with several techniques. Extraction with 0.5 M HCl dissolved poorly crystalline Fe oxides and small amounts of Fe in crystalline Fe oxides, and extracted Fe from phyllosilicates. Use of Ti-citrate-EDTA-bicarbonate results in more complete removal of crystalline Fe oxides. The average HCl-extractable Fe(III) concentration in the sediments closest to the crude-oil contamination (16.2 ??mol/g) has been reduced by up to 30% from background values (23.8 ??mol/g) as a result of Fe(III) reduction in contaminated anoxic groundwater. Iron(II) concentrations are elevated in sediments within an anoxic plume in the aquifer. Iron(II) values under the oil body (19.2 ??mol/g) are as much as 4 times those in the background sediments (4.6 ??mol/g), indicating incorporation of reduced Fe in the contaminated sediments. A 70% increase in total extractable Fe at the anoxic/oxic transition zone indicates reoxidation and precipitation of Fe mobilized from sediment in the anoxic plume. Scanning electron microscopy detected authigenic ferroan calcite in the anoxic sediments and confirmed abundant Fe(III) oxyhydroxides at the anoxic/oxic boundary. The redox biogeochemistry of Fe in this system is coupled to contaminant degradation and is important in predicting processes of hydrocarbon degradation.

Tuccillo, M. E.; Cozzarelli, I. M.; Herman, J. S.

1999-01-01

205

Bioremediation of a soil contaminated by hydrocarbon mixtures: the residual concentration problem  

Microsoft Academic Search

The phenomenon of residual concentration was investigated in the aerobic biodegradation of three different petroleum commercial products (i.e., kerosene, diesel fuel and a lubricating mineral oil) in static microcosms. Two different soils exhibiting different physical-chemical characteristics were used (i.e., a biologically treated hydrocarbon-contaminated soil and a pristine soil). Residual concentrations were observed and a simple way to take this phenomenon

M Nocentini; D Pinelli; F Fava

2000-01-01

206

Degradation of naturally contaminated polycyclic aromatic hydrocarbons in municipal sewage sludge by electron beam irradiation.  

PubMed

This study was to evaluate the degradation efficiency of naturally contaminated polycyclic aromatic hydrocarbons in sewage sludge by using electron beam irradiation as a function of the absorbed dose. Degradation efficiency of PAHs was near to 90% at the absorbed doses 5 kGy. The degradation of PAHs was "first order" reaction rates with respect to absorbed dose. The electron beam irradiation was found effective in means of removing PAHs in domestic wastewater. PMID:18491024

Chung, B Y; Cho, J Y; Song, C H; Park, B J

2008-05-20

207

Degradation of Naturally Contaminated Polycyclic Aromatic Hydrocarbons in Municipal Sewage Sludge by Electron Beam Irradiation  

Microsoft Academic Search

This study was to evaluate the degradation efficiency of naturally contaminated polycyclic aromatic hydrocarbons in sewage\\u000a sludge by using electron beam irradiation as a function of the absorbed dose. Degradation efficiency of PAHs was near to 90%\\u000a at the absorbed doses 5 kGy. The degradation of PAHs was “first order” reaction rates with respect to absorbed dose. The electron\\u000a beam irradiation

B. Y. Chung; J. Y. Cho; C. H. Song; B. J. Park

2008-01-01

208

Effect of Nutrient Amendments on Indigenous Hydrocarbon Biodegradation in Oil-Contaminated Beach Sediments  

Microsoft Academic Search

Three strategies of nutrient application are generally used for bioremediation purposes: Nutrient amendment to oil-contaminated beach sediments is a criti- cal factor for the enhancement of indigenous microbial activity andAddition of soluble mineral nutrients. Venosa et biodegradation of petroleum hydrocarbons in the intertidal marine al. (1996, 1997) showed that approximately 1.5 mg environment. In this study, we investigated the stimulatory

Ran Xu; Jeffrey P. Obbard

2003-01-01

209

Activity and Diversity of Methanogens in a Petroleum Hydrocarbon-Contaminated Aquifer  

Microsoft Academic Search

Methanogenic activity was investigated in a petroleum hydrocarbon-contaminated aquifer by using a series of four push-pull tests with acetate, formate, H2 plus CO2, or methanol to target different groups of me- thanogenic Archaea. Furthermore, the community composition of methanogens in water and aquifer material was explored by molecular analyses, i.e., fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE)

Jutta Kleikemper; Silvina A. Pombo; Martin H. Schroth; William V. Sigler; Manuel Pesaro; Josef Zeyer

2005-01-01

210

Cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and phenols in contaminated soil slurries  

Microsoft Academic Search

This work aimed to evaluate the relative contribution of soil catabolic activity, contaminant bioaccessibility, and nutrient levels on the biodegradation of field-aged polycyclic aromatic hydrocarbons and phenolic compounds in three municipal gas plant site soils. Extents of biodegradation achieved, in 6 week-long soil slurry assays, under the following conditions were compared: (i) with inoculation of catabolically active PAH and phenol-degrading

Ian J. Allan; Kirk T. Semple; Rina Hare; Brian J. Reid

2007-01-01

211

Predicting the Efficacy of Polycyclic Aromatic Hydrocarbon Bioremediation in Creosote-Contaminated Soil Using Bioavailability Assays  

Microsoft Academic Search

Nonexhaustive extraction (propanol, butanol, hydroxypropyl-?-cyclodextrin [HPCD]), persulfate oxidation and biodegradability assays were employed to determine the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in creosote-contaminated soil. After 16 weeks incubation, greater than 89% of three-ring compounds (acenaphthene, anthracene, fluorene, and phenanthrene) and 21% to 79% of four-ring compounds (benz[a]anthracene, chrysene, fluoranthene, and pyrene) were degraded by the indigenous microorganisms under biopile

Albert L. Juhasz; Natasha Waller; Richard Stewart

2005-01-01

212

Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1998 annual progress report  

Microsoft Academic Search

'The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones (i.e., environmental hormones) in different species present in aquatic ecosystems. Species of particular focus are those which can serve as sentinel species (e.g., amphibians) and, thus, provide early warning signals for more widespread impacts on an ecosystem and its wildlife and

McLachlan

1998-01-01

213

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

Microsoft Academic Search

A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes were amplified directly from aquifer material DNA by PCR with universally conserved or Bacteria- or Archaea-specific

MICHAEL A. DOJKA; PHILIP HUGENHOLTZ; N. R. Pace; S. K. Haack

1998-01-01

214

Leaching and microbial treatment of a soil contaminated by sulphide ore ashes and aromatic hydrocarbons  

Microsoft Academic Search

Contaminated soil from a historical industrial site and containing sulfide ore ashes and aromatic hydrocarbons underwent sequential\\u000a leaching by 0.5 M citrate and microbial treatments. Heavy metals leaching was with the following efficiency scale: Cu (58.7%)\\u000a > Pb (55.1%) > Zn (44.5%) > Cd (42.9%) > Cr (26.4%) > Ni (17.7%) > Co (14.0%) > As (12.4%) > Fe (5.3%) >

Alessandro D’Annibale; Vanessa Leonardi; Ermanno Federici; Franco Baldi; Fulvio Zecchini; Maurizio Petruccioli

2007-01-01

215

Analyses of polycyclic aromatic hydrocarbon-degrading bacteria isolated from contaminated soils  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria isolated from PAH-contaminated soils were analyzed genotypically and phenotypically for their capacity for metabolism of naphthalene and other PAH substrates. The methods used for the analyses were DNA hybridization using NAH7-derived gene probes, PAH spray plate assays, 14C-PAH mineralization assays, and dioxygenase activity assays. The results of the analyses showed a dominant number of PAH-degrading

Yeonghee Ahn; John Sanseverino; Gary S. Sayler

1999-01-01

216

Subsurface contaminant transport in the presence of colloids: Effect of nonlinear and nonequilibrium interactions  

Microsoft Academic Search

The effect of kinetic nonlinear sorption of contaminants in the presence of colloids is the focus of this study. Different sorption isotherms are considered where contaminant sorption and colloid deposition are assumed to be linear or nonlinear (Freundlich), and contaminant attachment to mobile and immobile colloids is assumed to follow either linear or Langmuir isotherms. Varying combinations accounting for different

Hesham M. Bekhit; Ahmed E. Hassan

2007-01-01

217

Evaluation of deep subsurface sampling procedures using serendipitous microbial contaminants as tracer organisms  

Microsoft Academic Search

Surface microbiological investigations are critically dependent on the procedures used to collect samples for study. It can be difficult to distinguish between indigenous organisms and those encountered as contaminants during the drilling process. We found that coliform bacteria contaminated drilling mud slurries. These bacteria proved useful as tracer organisms in evaluating the degree of microbial contamination accidentally encountered while drilling

Ralph E. Beeman; Joseph M. Suflita

1989-01-01

218

Modeling discrete gas bubble formation and mobilization during subsurface heating of contaminated zones  

Microsoft Academic Search

During thermal remediation the increase in subsurface temperature can lead to bubble formation and mobilization. In order to investigate the effect of gas formation on resulting aqueous concentrations, a 2D finite difference flow and mass transport model was developed which incorporates a macroscopic invasion percolation (MIP) model to simulate bubble expansion and movement. The model was used to simulate three

Magdalena M. Krol; Kevin G. Mumford; Richard L. Johnson; Brent E. Sleep

2011-01-01

219

Effect of temperature on the development of anaerobic cultures from a contaminated subsurface soil  

Microsoft Academic Search

Sulfats reduction, methanogenesis, and denitrification were successfully initiated with subsurface soil inocula from a hazardouz waste site. The metabolic rates of all three processes were increased by raising the incubation ‘temperature from 5 to 20'C. Methanogenesis and to a lesser degree sulfate reduction were significantly affected by reduced temperatures (i.e., below 10°C). Denitri fication proceeded much faster than the other

S. G. Pavlostathis; P. Zhuang

1991-01-01

220

Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments  

SciTech Connect

There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants

Holmes, Dawn; O'Neil, Regina; Vrionis, Helen A.; N'guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll, Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

2007-12-01

221

COMPARISON OF IMMUNOASSAY AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY FOR MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN CONTAMINATED SOIL  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are frequently encountered in the environment and may pose health concerns due to their carcinogenicity. A commercial enzyme-linked immunosorbent assay (ELISA), was evaluated as a screening method for monitoring PAHs at contaminated site...

222

PILOT-SCALE SUBCRITICAL WATER REMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON- AND PESTICIDE-CONTAMINATED SOIL. (R825394)  

EPA Science Inventory

Subcritical water (hot water under enough pressure to maintain the liquid state) was used to remove polycyclic aromatic hydrocarbons (PAHs) and pesticides from highly contaminated soils. Laboratory-scale (8 g of soil) experiments were used to determine conditions f...

223

RESEARCH PROJECT -- NITRATE AS AN ALTERNATE ELECTRON ACCEPTOR FOR BIOREMEDIATION OF FUEL-CONTAMINATED AQUIFERS (SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)  

EPA Science Inventory

For the past several years, an extensive investigation has been conducted into the feasibility of using nitrate as an alternate electron acceptor for stimulating anaerobic biodegradation of petroleum hydrocarbons for in situ bioremediation of contaminated aquifers. This has invo...

224

Development of Radon as a Natural Tracer for Monitoring the Remediation of NAPL Contamination in the Subsurface  

SciTech Connect

Dense non-aqueous phase liquids (DNAPLs) such as trichloroethene (TCE) and perchloroethene (PCE) present long-term challenges in terms of quantification in the subsurface at many DOE facilities. Over the past year we have continued investigating a potentially lower cost method for quantifying DNAPLs in the subsurface using naturally occurring, in situ dissolved radon as a partitioning tracer. Radon can be used as a partitioning tracer in both static (i.e., no flow) and dynamic methodologies (Semprini et al., 1993; Semprini et al., 1998; Semprini et al., 2000). The static radon method involves obtaining radon samples from DNAPL-contaminated and non-contaminated portions of the aquifer and using the change in radon concentrations to locate and quantify DNAPL saturation in the aquifer. The dynamic radon method incorporates single-well injection withdrawal (i.e., push-pull) tests to estimate radon retardation and DNAPL saturation. These methods have the potential to provide a robust method for DNAPL saturation quantification while decreasing the costs associated with these activities.

Davis, Brian M.; Semprini, Lewis and Istok, Jonathan

2002-06-01

225

Treatment Of Groundwater Contaminated With PAHs, Gasoline Hydrocarbons, And Methyl Tert -Butyl Ether In A Laboratory Biomass-Retaining Bioreactor  

EPA Science Inventory

In this study, we investigated the treatability of co-mingled groundwater contaminated with polycyclic aromatic hydrocarbons (PAHs), gasoline hydrocarbons, and methyl tert -butyl ether (MtBE) using an ex-situ aerobic biotreatment system. The PAHs of interest were nap...

226

RESEARCH PROJECT -- IN SITU CO-OXIDATION OF CHLORINATED SOLVENTS DURING BIOVENTING OF PETROLEUM HYDROCARBONS (SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)  

EPA Science Inventory

There are a large number of sites containing both petroleum hydrocarbons and chlorinated solvents. Fire training pits at military bases are the most common example. These were often used to dispose of waste oils and solvents. Incomplete burning resulted in releases of contamin...

227

Potential benefit of surfactants in a hydrocarbon contaminated soil washing process: fluorescence spectroscopy based assessment.  

PubMed

Soil washing is an ex situ soil remediation treatment process. The purpose of soil washing is to clean the major gravel and sand fractions, concentrating contamination into the fine silt and clay fractions. The addition of surfactants can improve the efficiency of this method. Here we report the use of UV fluorescence spectroscopy to assess the hydrocarbon cleaning process as a rapid and cost effective alternative to gas chromatography. Three wash solutions were tested on a total petroleum hydrocarbon contaminated soil: water, Sea Power 101 (SP101) at 1% (v/v) and Tween80 at 0.5% (w/v). The most effective to wash the gravel and sand was SP101 (54 and 65% improvement over the water only wash, respectively) which moved contamination to the silt fraction (94% of contaminants). Tween80 appeared not to enhance TPH removal efficiency from the gravel and sand fractions but did concentrate TPH in the effluent (95% more than water wash). In addition to TPH removal from gravel and sand, SP101 also showed potential benefit in the soil washing sedimentation process, enhancing sludge/water volume separation by 10% over the water only wash. In summary, fluorescence spectroscopy proved an effective technique to compare TPH removal efficiencies as part of soil washing laboratory based treatability testing. PMID:22503218

Uhmann, Amandine; Aspray, Thomas J

2012-04-03

228

Ecotoxicological and analytical assessment of hydrocarbon-contaminated soils and application to ecological risk assessment  

SciTech Connect

Ecotoxicological assessments of contaminated soil aim to understand the effect of introduced chemicals on the soil flora and fauna. Ecotoxicity test methods were developed and conducted on hydrocarbon-contaminated soils and on adjacent uncontaminated control soils from eight field locations. Tests included 7-d, 14-d, and chronic survival tests and reproduction assays for the earthworm (Eisenia fetida) and seed germination, root length, and plant growth assays for corn, lettuce, mustard, and wheat. Species-specific responses were observed with no-observed effect concentrations (NOECs) ranging from <1 to 100% contaminated soil. The 14-d earthworm survival NOEC was equal to or greater than the reproduction NOEC values for numbers of cocoons and juveniles, which were similar to one another. Cocoon and juvenile production varied among the control soils. Germination and root length NOECs for mustard and lettuce were less than NOECs for corn and wheat. Root length NOECs were similar to or less than seed germination NOECs. Statistically significant correlations for earthworm survival and seed germination as a function of hydrocarbon measurements were found. The 14-d earthworm survival and the seed germination tests are recommended for use in the context of a risk-based framework for the ecological assessment of contaminated sites.

Saterbak, A.; Toy, R.J.; Wong, D.C.L.; McMain, B.J.; Williams, M.P.; Dorn, P.B.; Brzuzy, L.P.; Chai, E.Y.; Salanitro, J.P.

1999-07-01

229

Comparison of Methods to Determine Oxygen Demand for Bioremediation of a Fuel Contaminated Aquifer.  

National Technical Information Service (NTIS)

Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. The methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with...

R. M. Powell R. W. Callaway J. T. Michalowski S. A. Vandegrift M. V. White

1988-01-01

230

COMPARISON OF METHODS TO DETERMINE OXYGEN DEMAND FOR BIOREMEDIATION OF A FUEL CONTAMINATED AQUIFER  

EPA Science Inventory

Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. The methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with a gas chromatographic te...

231

COMPARISON OF METHODS TO DETERMINE OXYGEN DEMAND FOR BIOREMEDIATION OF A FUEL CONTAMINATED AQUIFER  

EPA Science Inventory

Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. he methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with a gas chromatographic tec...

232

Polycyclic aromatic hydrocarbon contamination in stormwater detention pond sediments in coastal South Carolina.  

PubMed

The purpose of this study was to characterize the polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of stormwater detention ponds in coastal South Carolina. Levels of the sum of PAH analytes were significantly higher in the sediments of commercial ponds compared to that of reference, golf course, low-density residential, and high-density residential ponds. Isomer ratio analysis suggested that the predominant source of PAHs were pyrogenic; however, many ponds had a PAH signature consistent with mixed uncombusted and combusted PAH sources. PAH levels in these sediments could be modeled using both pond drainage area and pond surface area. These results demonstrate that the sediment from most commercial ponds, and a few residential and golf course ponds, were moderately contaminated with PAHs. PAH levels in these contaminated ponds exceeded between 42% and 75% of the ecological screening values for individual PAH analytes established by US EPA Region IV, suggesting that they may pose a toxicological risk to wildlife. PMID:19229645

Weinstein, John E; Crawford, Kevin D; Garner, Thomas R

2009-02-20

233

MODELING THE BIODEGRADATION OF ORGANIC CONTAMINANTS WITH TMVOCBIO  

Microsoft Academic Search

The contamination of soil and groundwater by organic contaminants, such as hydrocarbons and solvents, represents a potential risk for human health and for the environment. It has been observed in natural systems and verified by laboratory experiences that organic contaminants are actively degraded by naturally occurring micro-organisms living in the subsurface, which can use them as substrates for their metabolic

Alfredo Battistelli

234

[Biological treatments for contaminated soils: hydrocarbon contamination. Fungal applications in bioremediation treatment].  

PubMed

Bioremediation is a spontaneous or controlled process in which biological, mainly microbiological, methods are used to degrade or transform contaminants to non or less toxic products, reducing the environmental pollution. The most important parameters to define a contaminated site are: biodegradability, contaminant distribution, lixiviation grade, chemical reactivity of the contaminants, soil type and properties, oxygen availability and occurrence of inhibitory substances. Biological treatments of organic contaminations are based on the degradative abilities of the microorganisms. Therefore the knowledge on the physiology and ecology of the biological species or consortia involved as well as the characteristics of the polluted sites are decisive factors to select an adequate biorremediation protocol. Basidiomycetes which cause white rot decay of wood are able to degrade lignin and a variety of environmentally persistent pollutants. Thus, white rot fungi and their enzymes are thought to be useful not only in some industrial process like biopulping and biobleaching but also in bioremediation. This paper provides a review of different aspects of bioremediation technologies and recent advances on ligninolytic metabolism research. PMID:15709784

Martín Moreno, Carmen; González Becerra, Aldo; Blanco Santos, María José

2004-09-01

235

Deployment of Smart 3D Subsurface Contaminant Characterization at the Brookhaven Graphite Research Reactor  

Microsoft Academic Search

The Brookhaven Graphite Research Reactor (BGRR) Historical Site Assessment (BNL 1999) identified contamination inside the Below Grade Ducts (BGD) resulting from the deposition of fission and activation products from the pile on the inner carbon steel liner during reactor operations. Due to partial flooding of the BGD since shutdown, some of this contamination may have leaked out of the ducts

Terrence Sullivan; John Heiser; Paul Kalb; Lawrence Milian; Clyde Newson; Manny Lilimpakas; Tom Daniels

2002-01-01

236

MODELING THE REBOUNDING OF CONTAMINANT CONCENTRATIONS IN SUBSURFACE GASEOUS PHASE DURING INTERMITTENT SOIL VAPOR EXTRACTION OPERATION  

Microsoft Academic Search

Soil vapor extraction (SVE) process for contaminated soil remediation often shows a tailing of the breakthrough concentration in the contaminant plume and rebounding of gaseous phase concentration after a pause of the extraction operation. These phenomena are believed to have something to do with the limitation of mass transfer between mobile fluid and some stagnant aggregates or clay lens. An

Mei-Sheue Wang; Shian-Chee Wu; Chun-Wei Kuo

2007-01-01

237

Field screening of polycyclic hydrocarbons contamination in soil using a portable synchronous scanning spectrofluorometer  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAH) contamination is a considerable problem at various hazardous waste sites. Sources of PAH contamination include incomplete combustion processes, wood preservatives, and the fuel industry. The development of rapid, cost-effective field screening techniques to qualitate or quantitate potential PAH contamination could result in improved remediation efficiency. We have recently developed a portable spectrofluorometer for screening potential PAH contaminants at field sites using the synchronous fluorescence approach. Synchronous fluorescence differs from the more conventional excitation or emission fluorescence as both monochromators are scanned simultaneously with a constant wavelength offset ((Delta) (lambda) ) between the two. The portable spectrofluorometer was developed at Oak Ridge National Laboratory (ORNL) for the U.S. Environmental Protection Agency (EPA), National Exposure Research Laboratory, and recently field tested at the American Creosote Works Superfund Site in Jackson, Tennessee. In this paper, the portable spectrofluorometer was used to field screen several contaminated soil areas located at the Morristown Industrial Site in Morristown, Tennessee using the synchronous fluorescence technique. An attempt to quantify PAH contamination was performed using the NIST 1647a priority pollutant standard to generate a calibration curve. Representative samples were subsequently related to the results obtained from standard laboratory measurements.

Alarie, Jean P.; Watts, Wendi; Miller, Don; Hyfantis, George; Peeler, George; Engelmann, William H.; Vo-Dinh, Tuan

1995-10-01

238

Plant performance, dioxygenase-expressing rhizosphere bacteria, and biodegradation of weathered hydrocarbons in contaminated soil.  

PubMed

Two greenhouse pot experiments were conducted to investigate the potential of 13 plant species (grasses, cruciferes, legumes, herbs) to thrive in a long-term contaminated soil from a former manufactured gas plant (MGP) site, to promote the proliferation of total and aromatic ring dioxygenase-expressing bacteria (ARDB) in the root zone, and to foster the biodegradation of petrol hydrocarbons (PHCs) and polycyclic aromatic hydrocarbons (PAHs). PHCs at 23200 mg kg(-1) and PAHs at 2194 mg kg(-1) reduced seed germination, plant survival, and shoot yields for most plants. Total bacteria and ARDB were generally more abundant in contaminated soil and were most numerous in the rhizosphere of mustard. During 68 d, the loss of total petrol hydrocarbons (TPHs) and total US EPA priority PAHs (TPAHs) was greatest in soil planted with hemp and mustard. Pea, cress, and pansy increased the amounts of PAHs extracted from soil, including an almost 60% increase for dibenzo(ah)anthracene. Plants may enhance the chemical extractability and perhaps biological availability of initially unextractable molecules. PMID:15996713

Liste, Hans-Holger; Prutz, Ines

2005-07-05

239

A new risk and stochastic analysis of monitoring and remediation in subsurface contamination  

NASA Astrophysics Data System (ADS)

Sanitary landfills constitute the most widely used management approach for the disposal of solid wastes because of their simplicity and cost effectiveness. However, historical records indicate that landfills exhibit a high failure rate of groundwater contamination. Successful detection of aquifer contamination via monitoring wells is a complicated problem with many factors, such as the heterogeneity of the geologic environment, the dispersion of contamination into the geologic medium, the quantity and nature of the contaminants, the number and location of the monitoring wells, and the frequency of sampling, all contributing to the uncertainty of early detection. Detection of contaminants, of course, is of value if remedial actions follow as soon as possible, so that the volume of contaminated groundwater to be treated is minimized. Practically, there is always a time lag between contaminant detection and remedial action response. Administrative decisions and arrangements with local contractors initiate remedial procedures introduces a time lag between detection and remediation time. During this time lag a plume continues to move into an aquifer contaminating larger groundwater volumes. In the present study these issues are addressed by investigating the case of instantaneous leakage from a landfill facility into a heterogeneous aquifer. The stochastic Monte Carlo framework was used to address, in two dimensions, the problem of evaluating the effectiveness of contaminant detection in heterogeneous aquifers by linear networks of monitoring wells. Numerical experiments based on the random-walk tracking-particle method were conducted to determine the detection probabilities and to calculate contaminated areas at different time steps. Several cases were studied assuming different levels of geologic heterogeneity, contamination dispersion, detectable contamination limits and monitoring wells' sampling frequencies. A new perspective is introduced for the correction of risk analyses; contemporary risk analyses consider the cost of alternative remediation procedures by assuming that the contamination area to be remediated coincides with the area calculated at the time of detection. However, there is always a considerable lag between the time that a plume is detected and the time when remediation commences. This time lag constitutes a random variable that depends on available resources and technologies, as well as efficiency of administration decision-making. An expression is proposed that accounts for the delay between detection and remedial action in order to provide a correction to decision analyses that evaluate the economic worth of well monitoring. This expression illustrates that delays over 3 years are equivalent to reducing the monitoring performance of 12 wells to that of a much lower number of wells, or equally, having to consider higher failure costs than those assumed in current risk analyses.

Papapetridis, K.; Paleologos, E.

2012-04-01

240

In situ biogeochemical reduction of hydrocarbon contamination of ground water by injecting hydrogen peroxide: A case study in a Montana aquifer contaminated by wood preservatives  

SciTech Connect

The site is an active lumber mill that has been contaminated by long-term releases of creosote and pentachlorophenol. Two aquifers underlying the site have become contaminated, and large contaminant plumes have developed. The shallower (upper) aquifer poses the greatest risk to public and environmental health, and was a focus of restoration investigations. Among the restoration options for upper aquifer remediation was in situ bioremediation. This option involves enhancement of subsurface biogeochemical (primarily microbial) processes to produce contaminant destruction, and offers a number of potential benefits, including rapid aquifer restoration, low economic impact, and minimal site disruption. Biogeochemical parameters in the groundwater were examined in wells along a transect that extended into the contaminant plume. A pilot-scale study was initiated in July 1987, in which a source of oxygen (hydrogen peroxide) was continuously injected into a contaminated region of the upper aquifer. This study is the first field-verification that hydrogen peroxide injection into a contaminated aquifer can create large-scale oxic conditions in groundwater. Oxygen supplementation resulted in significant reductions in contaminated concentrations within the contaminant plume via enhancement of subsurfaces microbial activity, indicating that this approach can be effective for aquifer restoration.

Piotrowski, M.R.

1989-01-01

241

Quantitative assessment of hydrocarbon contamination in soil using reflectance spectroscopy: a "multipath" approach.  

PubMed

Petroleum hydrocarbons are contaminants of great significance. The commonly used analytic method for assessing total petroleum hydrocarbons (TPH) in soil samples is based on extraction with 1,1,2-Trichlorotrifluoroethane (Freon 113), a substance prohibited to use by the Environmental Protection Agency. During the past 20 years, a new quantitative methodology that uses the reflected radiation of solids has been widely adopted. By using this approach, the reflectance radiation across the visible, near infrared-shortwave infrared region (400-2500 nm) is modeled against constituents determined using traditional analytic chemistry methods and then used to predict unknown samples. This technology is environmentally friendly and permits rapid and cost-effective measurements of large numbers of samples. Thus, this method dramatically reduces chemical analytical costs and secondary pollution, enabling a new dimension of environmental monitoring. In this study we adapted this approach and developed effective steps in which hydrocarbon contamination in soils can be determined rapidly, accurately, and cost effectively solely from reflectance spectroscopy. Artificial contaminated samples were analyzed chemically and spectrally to form a database of five soils contaminated with three types of petroleum hydrocarbons (PHCs), creating 15 datasets of 48 samples each at contamination levels of 50-5000 wt% ppm (parts per million). A brute force preprocessing approach was used by combining eight different preprocessing techniques with all possible datasets, resulting in 120 different mutations for each dataset. The brute force was done based on an innovative computing system developed for this study. A new parameter for evaluating model performance scoring (MPS) is proposed based on a combination of several common statistical parameters. The effect of dividing the data into training validation and test sets on modeling accuracy is also discussed. The results of this study clearly show that predicting TPH levels at low concentrations in selected soils at high precision levels is viable. Dividing a dataset into training, validation, and test groups affects the modeling process, and different preprocessing methods, alone or in combination, need to be selected based on soil type and PHC type. MPS was found to be a better parameter for selecting the best performing model than ratio of prediction to deviation, yielding models with the same performance but less complicated and more stable. The use of the "all possibilities" system proved to be mandatory for efficient optimal modeling of reflectance spectroscopy data. PMID:24160885

Schwartz, Guy; Ben-Dor, Eyal; Eshel, Gil

2013-11-01

242

Research on the degradation of petroleum hydrocarbons on the effect of microbial activity in oil-contaminated sites  

Microsoft Academic Search

Microbe is the principal part of microbial biodegradation of soil petroleum hydrocarbons, so how to adjust the environmental conditions of the contaminated site and enhance its activity is the key to improving the efficiency of oil degradation. By collecting the original oil-contaminated soil taken in an oil deposit in Northeast and measuring soil microbial activity and indicators of environmental factors,

Jianchao Han; Yuesuo Yang

2011-01-01

243

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

EPA Science Inventory

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

244

Hydrocarbons in sediments of a chronically contaminated bay: the challenge of source assignment.  

PubMed

Aliphatic hydrocarbons and 39 PAH (parental and alkylated homologs) determined in ca. 100 sediment samples from the Guanabara Bay, Rio de Janeiro, were evaluated for source discrimination using new approaches. Concentrations of total PAH were in the range of 96-135,000 ?g kg(-1) similar to other coastal urbanized embayment. Traditional diagnostic ratios were not as efficient PAH source indicators, e.g. biomass combustion was assigned as the major source of the pyrolytic PAH although the hydrographic basin is highly industrialized and urbanized. It is proved petrogenic imprint cannot be detected if only the 16 USEPA PAH are determined. The high production in the eutrophic system is not apparent in the aliphatic fraction dominated by land derived n-alkanes due to the effectiveness of microbial degradation. The present work demonstrates the complexity of hydrocarbon forensics when applied to chronically contaminated environments. PMID:22178011

Wagener, Angela de L R; Meniconi, Maria de Fátima G; Hamacher, Claudia; Farias, Cassia O; da Silva, Gilson C; Gabardo, Irene T; Scofield, Arthur de L

2011-12-16

245

Innovative Technology Summary Report: In Situ Gaseous Reduction System. Subsurface Contaminants Focus Area.  

National Technical Information Service (NTIS)

The goal of this project is the in situ immobilization and detoxification of specific metal contaminants by changing their chemical state. The injection of a gas mixture containing low concentrations of hydrogen sulfide into soil can change the oxidation ...

2000-01-01

246

CsI(Tl) with photodiodes for identifying subsurface radionuclide contamination.  

National Technical Information Service (NTIS)

At the US Department of Energy's Hanford Site near Richland, Washington, underground radioactive contamination exists as the result of leaks, spills, and intentional disposal of waste products from plutonium-production operations. Characterizing these con...

D. C. Stromswold J. E. Meisner W. F. Nicaise

1994-01-01

247

Assessment of petroleum-hydrocarbon contamination in the surficial sediments and ground water at three former underground storage tank locations, Fort Jackson, South Carolina, 1995  

USGS Publications Warehouse

Ground-water and sediment contamination by petroleum hydrocarbons resulting from leaks and overfills was detected during tank removal activities at three former underground storage tank locations at Fort Jackson, near Columbia, South Carolina. Investigations were initiated to assess the effect of contamination to the surficial aquifer at Sites 1062, 2438, and 2444. These investigations involved the installation of permanent monitoring wells and the collection and analysis of sediment and ground-water samples at the three sites. Water-level data were collected at all sites to determine hydraulic gradients and the direction of ground-water flow. In addition, aquifer tests were made at Site 1062 to determine the hydraulic conductivity of the surficial aquifer at that site. Sediment borings were made at the three sites to collect subsurface-sediment samples for lithologic description and laboratory analyses, and for the installation of ground-water monitoring wells. Laboratory analyses of sediment samples collected from boreholes at Site 1062 indicated elevated concentrations of petroleum hydrocarbons at three locations. Total Petroleum Hydrocarbons - Diesel Range Organics were detected at one borehole at a concentration of 388,000 micrograms per kilogram. Total benzene, toluene, ethylbenzene, and xylene concentrations in sediment from the site ranged from less than 350 to over 100,000 micrograms per kilogram. Total lead was detected at concentrations ranging from 2,900 to 5,900 micrograms per kilogram. Petroleum hydrocarbons were detected at Site 2438 in one borehole at a trace concentration of 112 micrograms per kilogram of para- and meta-xylenes. No concentrations exceeding the detection limits were reported for petroleum hydrocarbons in sediment samples collected from Site 2444; however, total lead was detected in sediment samples from two boreholes, each at concentrations of 600 micrograms per kilogram. Ground-water samples were collected from each site for laboratory analysis and field-property determinations. Petroleum hydrocarbons and lead were detected at concentrations exceeding regulatory limits for drinking water in ground water from Site 1062 only. Petroleum hydrocarbons were detected in ground water from three wells at Site 1062, with the highest concentrations occurring in the area of the former underground storage tanks. Benzene was detected at concentrations as much as 28 micrograms per liter; toluene as much as 558 micrograms per liter; para- and meta-xylenes as much as 993 micrograms per liter; and naphthalene as much as 236 micrograms per liter. Ethylbenzene and ortho-xylene were detected in one well at concentrations of 70 and 6 micrograms per liter, respectively. Dissolved lead was detected in ground water from four wells at concentrations from 5 to 152 micrograms per liter. Analysis of ground-water samples collected from Sites 2438 and 2444 showed little evidence of petroleum-hydrocarbon contamination. Petroleum hydrocarbons were not detected in any of the ground-water samples collected from Site 2438. With the exception of a low concentration of naphthalene (11 micrograms per liter) detected in ground water from one well, petroleum hydrocarbons and lead were not detected in ground water collected from Site 2444.

Robertson, J. F.

1996-01-01

248

Transport of contaminants from energy-process-waste leachates through subsurface soils and soil components: laboratory experiments  

SciTech Connect

The subsurface transport and attenuation of inorganic contaminants common to a variety of energy process waste leachates are being studied using laboratory column methods. Anionic species currently being emphasized are As, B, Mo, and Se. Transport of the cations Cd and Ni is also being studied. The solid adsorbents consist of three soil mineral components (silica sand, kaolinite, and goethite), and four subsurface soils (a dunal sand, an oxidic sandy clay loam, an acidic clay loam, and an alkaline clay loam). Breakthrough patterns of these species from packed soil columns are followed by monitoring eluent concentrations vs time under carefully controlled laboratory conditions. This report describes the experimental methods being used, the results of preliminary batch adsorption studies, and the results of column experiments completed through calendar year 1981. Using column influent concentrations of about 10 mg/l, adsorption (mmoles/100 g) has been determined from the eluent volume corresponding to 50% breakthrough. On silica sand, kaolinite, dunal sand, and goethite, respectively, these are 2.0 x 10/sup -4/, 0.020, 0.013, and 0.31 for cadmium, 4.4 x 10/sup -4/, 0.039, 0.020, and 0.98 for nickel. On kaolinite, dunal sand, and goethite, respectively, adsorption values (mmoles/100 g) are As (0.24, 0.019, and 20.5), B (0.041, 0.0019, and 1.77), Mo (0.048, 0.0010, and 5.93), and Se (0.029, 0.00048, and 1.30). Arsenic is the most highly adsorbed contaminant species and goethite has the largest adsorption capacity of the adsorbents.

Wangen, L.E.; Stallings, E.A.; Walker, R.D.

1982-08-01

249

Coupled modeling of hydrogeochemical and electrical resistivity data for exploring the impact of recharge on subsurface contamination  

SciTech Connect

The application of geophysical methods, in particular, electrical resistivity measurements, may be useful for monitoring subsurface contamination. However, interpreting geophysical data without additional data and without considering the associated hydrogeochemical processes is challenging since the geophysical response is sensitive to not only heterogeneity in rock properties but also to the saturation and chemical composition of pore fluids. We present an inverse modeling framework that incorporates the simulation of hydrogeochemical processes and time-lapse electrical resistivity data and apply it to various borehole and cross-borehole data sets collected in 2008 near the S-3 Ponds at the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge site, where efforts are underway to better understand freshwater recharge and associated contaminant dilution. Our goal is to show that the coupled hydrogeochemical-geophysical modeling framework can be used to (1) develop a model that honors all the available data sets, (2) help understand the response of the geophysical data to subsurface properties and processes at the site, and (3) allow for the estimation of petrophysical parameters needed for interpreting the geophysical data. We present a series of cases involving different data sets and increasingly complex models and find that the approach provides useful information about soil properties, recharge-related transport processes, and the geophysical response. Spatial heterogeneity of the petrophysical model can be described sufficiently with two layers, and its parameters can be estimated concurrently with the hydrogeochemical parameters. For successful application of the approach, the parameters of interest must be sensitive to the available data, and the experimental conditions must be carefully modeled.

Kowalsky, Mike [Lawrence Berkeley National Laboratory (LBNL); Gasperikova, E. [Lawrence Berkeley National Laboratory (LBNL); Finsterle, S. [Lawrence Berkeley National Laboratory (LBNL); Watson, David B [ORNL; Baker, Gregory S. [University of Tennessee, Knoxville (UTK); Hubbard, Susan S [Lawrence Berkeley National Laboratory (LBNL)

2011-01-01

250

Bioremediation of poly-aromatic hydrocarbon (PAH)-contaminated soil by composting  

SciTech Connect

This paper presents a comprehensive and critical review of research on different co-composting approaches to bioremediate hydrocarbon contaminated soil, organisms that have been found to degrade PAHs, and PAH breakdown products. Advantages and limitations of using certain groups of organisms and recommended areas of further research effort are identified. Studies investigating the use of composting techniques to treat contaminated soil are broad ranging and differ in many respects, which makes comparison of the different approaches very difficult. Many studies have investigated the use of specific bio-additives in the form of bacteria or fungi with the aim of accelerating contaminant removal; however, few have employed microbial consortia containing organisms from both kingdoms despite knowledge suggesting synergistic relationships exist between them in contaminant removal. Recommendations suggest that further studies should attempt to systemize the investigations of composting approaches to bio-remediate PAH-contaminated soil, to focus on harnessing the biodegradative capacity of both bacteria and fungi to create a cooperative environment for PAH degradation, and to further investigate the array of PAHs that can be lost during the composting process by either leaching or volatilization.

Loick, N.; Hobbs, P.J.; Hale, M.D.C.; Jones, D.L. [University of Wales, Bangor (United Kingdom). School of Environmental & Natural Resources

2009-07-01

251

PROGRESS REPORT. FIXATION MECHANISMS AND DESORPTION RATES OF SORBED CS IN HIGH-LEVEL WASTE CONTAMINATED SUBSURFACE SEDIMENTS: IMPLICATIONS TO FUTURE BEHAVIOR AND IN-GROUND STABILITY  

EPA Science Inventory

This project is focused on defining the in-ground geochemistry of sorbed 137Cs released from high-level waste tanks, so that better future projections can be made of Cs mobility in the vadose zone. The project will study Cs-contaminated subsurface sediments from various Hanford t...

252

Homogeneous Reactor Experiment (HRE) Pond cryogenic barrier technology demonstration: Pre-barrier subsurface hydrology and contaminant transport investigation  

SciTech Connect

The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes that has since been drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by a tributary that empties into Melton Branch Creek and that contains significant concentrations of radioactive contaminants, primarily {sup 90}Sr. Because of the proximity of the tributary to the HRE disposal site and the probable flow of groundwater from the site to the tributary, it is hypothesized that the HRE Pond is a source of contamination to he creek. As a means for temporary containment of contaminants within the impoundment, a cryogenic barrier technology demonstration was initiated in FY96 with a background hydrologic investigation that continued through FY97. Cryogenic equipment installation was completed in FY97, and freezing was initiated in September of 1997. This report documents the results of a hydrologic and geologic investigation of the HRE Pond/cryogenic barrier site. The purpose of this investigation is to evaluate the hydrologic conditions within and around the impoundment in order to meet the following objectives: (1) to provide a pre-barrier subsurface hydrologic baseline for post-barrier performance assessment; (2) to confirm that the impoundment is hydraulically connected to the surrounding sediments; and (3) to determine the likely contaminant exit pathways from the impoundment. The methods of investigation included water level and temperature monitoring in a network of wells and standpipes in and surrounding the impoundment, a helium tracer test conducted under ambient flow conditions, and geologic logging during the drilling of boreholes for installation of cryogenic probes and temperature monitoring wells.

Moline, G.R.

1998-03-01

253

Influence of Microbial Iron and Nitrate Reduction on Subsurface Iron Biogeochemistry and Contaminant Metal Mobilization  

SciTech Connect

Although toxic metal and radionuclide contaminants can not be destroyed, their toxicity and mobility can be dramatically altered by microbial activity. In addition to toxic metals, many contaminated sites contain both iron-containing minerals and co-contaminants such as nitrate NO{sub 3}{sup -}. Successful implementation of metal and radionuclide bioremediation strategies in such environments requires an understanding of the complex microbial and geochemical interactions that influence the redox speciation and mobility of toxic metals. Our specific objectives have been to (1) determine the effect of iron oxide mineral reduction on the mobility of sorbed, representative toxic metals (Zn{sup 2+}), (2) study the biogeochemical interactions that may occur during microbial reduction of NO{sub 3}{sup -} and iron oxide minerals, and (3) evaluate the kinetics of NO{sub 3}{sup -}-dependent, microbial oxidation of ferrous iron (Fe{sup 2+}).

Flynn W. Picardal

2002-04-10

254

Acute toxicity of PAH (polycyclic aromatic hydrocarbons) contaminated sediments to the estuarine fish, Leiostomus xanthurus  

SciTech Connect

High concentrations of polycyclic aromatic hydrocarbons (PAH) have been found in the Elizabeth River, Virginia, especially in the Southern Branch near a former creosote wood preservation plant. Although acute mortality of fish directly attributable to high PAH concentrations in sediment and water is unreported in the Elizabeth River, fish of several species often exhibit fin erosion and other external lesions. During previous laboratory experiments with spot (Leiostomus xanthurus) exposed to naturally contaminated sediments from Elizabeth River Station 217 the authors observed acute mortalities within 8 days as well as fin erosion, ulceration of the lateral body surface, and several types of lesions of internal organs. Exposure to effluent from primary exposure tanks resulted in ulcerations and cataracts, but no mortalities. The present study was conducted to determine (1) the concentration of contaminated sediment causing an acute lethal effect on L. xanthurus exposed either to sediment or to water which had been in contact with sediment.

Roberts, M.H. Jr.; Hargis, W.J. Jr.; Strobel, C.J.; De Lisle, P.F.

1989-01-01

255

[Petroleum hydrocarbon contamination and impact on soil characteristics from oilfield Momoge Wetland].  

PubMed

Momoge Wetland is an important international wetland. Crude oil exploration and production have been the largest anthropogenic factor contributing to the degradation of Momoge Wetland, China. To study the effects of crude oil residuals on wetland soils, the total petroleum hydrocarbon (TPH), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) were examined, as well as for pH and electricity conductivity (EC) from oilfield and uncontaminated area in Momoge Wetland. All contaminated areas had significantly higher (p < 0.05) contents of TPH than those of the uncontaminated areas. For 5 a, 10 a and 20 a oil wells, the TPH were 30-fold, 60-fold, and 111-fold of the control sites. Soils from 10 a or over 10 a oil wells in oilfield were the major petroleum contamination area with values ranging from 16,885 mg x kg(-1) to 31,230 mg x kg(-1). There was a significantly positive correlation between TOC and TPH contents in oilfield(r = 0.88, p < 0.05). Oil residuals in soil caused the decrease of TN and TP and the maximum of decline were 33% and 28%, respectively. Contaminated sites also exhibited significantly higher (p < 0.05) pH values, C:N and C:P ratios. These trends became progressively obvious with the length of time the oil well was in production. Soil petroleum contamination also resulted the increase of the EC, however the impact of TPH on EC were not significant(p > 0.05). Collectively, petroleum hydrocarbon pollution has caused some major changes in soil properties in Momoge Wetland. PMID:19799307

Wang, Xiao-yu; Feng, Jiang; Wang, Jing

2009-08-15

256

Modelling of spatial contaminant probabilities of occurrence of chlorinated hydrocarbons in an urban aquifer.  

PubMed

In this study, a 3D urban groundwater model is presented which serves for calculation of multispecies contaminant transport in the subsurface on the regional scale. The total model consists of two submodels, the groundwater flow and reactive transport model, and is validated against field data. The model equations are solved applying finite element method. A sensitivity analysis is carried out to perform parameter identification of flow, transport and reaction processes. Coming from the latter, stochastic variation of flow, transport, and reaction input parameters and Monte Carlo simulation are used in calculating probabilities of pollutant occurrence in the domain. These probabilities could be part of determining future spots of contamination and their measure of damages. Application and validation is exemplarily shown for a contaminated site in Braunschweig (Germany), where a vast plume of chlorinated ethenes pollutes the groundwater. With respect to field application, the methods used for modelling reveal feasible and helpful tools to assess natural attenuation (MNA) and the risk that might be reduced by remediation actions. PMID:21858434

Greis, Tillman; Helmholz, Kathrin; Schöniger, Hans Matthias; Haarstrick, Andreas

2011-08-20

257

Biodegradation of polycyclic aromatic hydrocarbons in oil-contaminated beach sediments treated with nutrient amendments.  

PubMed

Microbial biodegradation of polycyclic aromatic hydrocarbons (PAHs) during the process of bioremediation can be constrained by lack of nutrients, low bioavailability of the contaminants, or scarcity of PAH-biodegrading microorganisms. This study focused on addressing the limitation of nutrient availability for PAH biodegradation in oil-contaminated beach sediments. In our previous study, three nutrient sources including inorganic soluble nutrients, the slow-release fertilizer Osmocote (Os; Scotts, Marysville, OH) and Inipol EAP-22 (Ip; ATOFINA Chemicals, Philadelphia, PA), as well as their combinations, were applied to beach sediments contaminated with an Arabian light crude oil. Osmocote was the most effective nutrient source for aliphatic biodegradation. This study presents data on PAH biodegradation in the oil-spiked beach sediments amended with the three nutrients. Biodegradation of total target PAHs (two- to six-ring) in all treatments followed a first-order biodegradation model. The biodegradation rates of total target PAHs in the sediments treated with Os were significantly higher than those without. On Day 45, approximately 9.3% of total target PAHs remained in the sediments amended with Os alone, significantly lower than the 54.2 to 58.0% remaining in sediment treatments without Os. Amendment with Inipol or soluble nutrients alone, or in combination, did not stimulate biodegradation rates of PAHs with a ring number higher than 2. The slow-release fertilizer (Os) is therefore recommended as an effective nutrient amendment for intrinsic biodegradation of PAHs in oil-contaminated beach sediments. PMID:15224921

Xu, Ran; Obbard, Jeffrey P

258

Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil  

SciTech Connect

The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.

Lemieux, C.L.; Lambert, A.B.; Lundstedt, S.; Tysklind, M.; White, P.A. [Health Canada, Ottawa, ON (Canada). Safe Environment Program

2008-04-15

259

Bioremediation of hydrocarbon-contaminated soils and groundwater in northern climates  

SciTech Connect

A field demonstration and research project was conducted in Fairbanks, Alaska, to demonstrate, evaluate, and document the construction and operation of three selected bioremediation technologies-landfarming, recirculating leachbeds, and infiltration galleries. Landfarming involves adding water and nutrients to contaminated soil to stimulate microbial activity and contaminant degradation. Infiltration galleries are dynamic in-situ treatment systems designed to stimulate microbial activity and subsequent hydrocarbon degradation by circulating nutrient and oxygen-amended water through petroleum-contaminated soil. Recirculating leachbeds, in a way similar to slurry reactors, aerate and mix nutrients with contaminated soil, and can be built as on-site bioreactors. Estimated biotreatment costs in the landfarm were between $20 to $30 per cubic yard ($15 to $23 per cubic meter). Nutrient placement has been demonstrated to be a critical factor, even though the site is tilled and mixed frequently. Success of the infiltration gallery was more difficult to document. Benzene was detected at less than 2 ppb and BTEX levels were less than 5 ppb for water extracted from the pumping well during 1992, which is significantly lower than the 1991 levels. Problems were encountered during the brief operation of the recirculating leach bed, but a similar system has performed well. Relatively simple, low-cost techniques provided significant potential for improving degradation rates.

Reynolds, C.M.; Braely, W.A.; Travis, M.D.; Perry, L.B.; Iskandar, I.K.

1998-03-01

260

Microbial Transformation of Polycyclic Aromatic Hydrocarbons in Pristine and Petroleum-Contaminated Sediments †  

PubMed Central

To determine rates of microbial transformation of polycyclic aromatic hydrocarbons (PAH) in freshwater sediments, 14C-labeled PAH were incubated with samples from both pristine and petroleum-contaminated streams. Evolved 14CO2 was trapped in KOH, unaltered PAH and polar metabolic intermediate fractions were quantitated after sediment extraction and column chromatography, and bound cellular 14C was measured in sediment residues. Large fractions of 14C were incorporated into microbial cellular material; therefore, measurement of rates of 14CO2 evolution alone would seriously underestimate transformation rates of [14C]naphthalene and [14C]anthracene. PAH compound turnover times in petroleum-contaminated sediment increased from 7.1 h for naphthalene to 400 h for anthracene, 10,000 h for benz(a)anthracene, and more than 30,000 h for benz(a)pyrene. Turnover times in uncontaminated stream sediment were 10 to 400 times greater than in contaminated samples, while absolute rates of PAH transformation (micrograms of PAH per gram of sediment per hour) were 3,000 to 125,000 times greater in contaminated sediment. The data indicate that four- and five-ring PAH compounds, several of which are carcinogenic, may persist even in sediments that have received chronic PAH inputs and that support microbial populations capable of transforming two- and three-ring PAH compounds.

Herbes, S. E.; Schwall, L. R.

1978-01-01

261

Effect of nutrient amendments on indigenous hydrocarbon biodegradation in oil-contaminated beach sediments.  

PubMed

Nutrient amendment to oil-contaminated beach sediments is a critical factor for the enhancement of indigenous microbial activity and biodegradation of petroleum hydrocarbons in the intertidal marine environment. In this study, we investigated the stimulatory effect of the slow-release fertilizers Osmocote (Os; Scotts, Marysville, OH) and Inipol EAP-22 (Ip; ATOFINA Chemicals, Philadelphia, PA) combined with inorganic nutrients on the bioremediation of oil-spiked beach sediments using an open irrigation system with artificial seawater over a 45-d period. Osmocote is comprised of a semipermeable membrane surrounding water-soluble inorganic N, P, and K. Inipol, which contains organic N and P, has been used for oil cleanup on beach substrate. Nutrient concentrations and microbial activity in sediments were monitored by analyzing sediment leachates and metabolic dehydrogenase activity of the microbial biomass, respectively. Loss of aliphatics (n-C12 to n-C33, pristane, and phytane) was significantly greater (total loss between 95 and 97%) in oil-spiked sediments treated with Os alone or in combination with other nutrient amendments, compared with an unamended oil-spiked control (26% loss) or sediments treated with the other nutrient amendments (28-65% loss). A combination of Os and soluble nutrients (SN) was favorable for the rapid metabolic stimulation of the indigenous microbial biomass, the sustained release of nutrients, and the enhanced biodegradation of petroleum hydrocarbons in leached, oil-contaminated sediments. PMID:12931877

Xu, Ran; Obbard, Jeffrey P

262

Hydraulic conductivity dependency of biodegradation of fuel hydrocarbon contaminants in a natural attenuation field site  

NASA Astrophysics Data System (ADS)

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene(B), toluene (T), ethyl benzene (E), and xylene(X). The second, a pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rates associated with each of the K zones. In both the mass loss model and the pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distribution is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.

Lu, G.; Zheng, C.

2003-12-01

263

Characterization of the relationship between microbial degradation processes at a hydrocarbon contaminated site using isotopic methods  

NASA Astrophysics Data System (ADS)

Decisions to employ monitored natural attenuation (MNA) as a remediation strategy at contaminated field sites require a comprehensive characterization of the site-specific biodegradation processes. In the present study, compound-specific carbon and hydrogen isotope analysis (CSIA) was used to investigate intrinsic biodegradation of benzene and ethylbenzene in an aquifer with high levels of aromatic and aliphatic hydrocarbon contamination. Hydrochemical data and isotope fractionation analysis of sulfate and methane was used complementarily to elucidate microbial degradation processes over the course of a three year period, consisting of six sampling campaigns, in the industrial area of Weißandt-Gölzau (Saxony-Anhalt, Germany).Enrichment of 13C and 2H isotopes in the residual benzene and ethylbenzene pool downgradient from the pollution sources provided evidence of biodegradation of BTEX compounds at this site, targeting both compounds as the key contaminants of concern. The enrichment of heavy sulfur isotopes accompanied by decreasing sulfate concentrations and the accumulation of isotopically light methane suggested that sulfate-reducing and methanogenic processes are the major contributors to overall biodegradation in this aquifer. Along the contaminant plume, the oxidation of methane with ?13CCH4 values of up to + 17.5‰ was detected. This demonstrates that methane formed in the contaminant source can be transported along groundwater flow paths and be oxidized in areas with higher redox potentials, thereby competing directly with the pollutants for electron acceptors. Hydrochemical and isotope data was summarized in a conceptual model to assess whether MNA can be used as viable remediation strategy in Weißandt-Gölzau. The presented results demonstrate the benefits of combining different isotopic methods and hydrochemical approaches to evaluate the fate of organic pollutants in contaminated aquifers.

Feisthauer, Stefan; Seidel, Martin; Bombach, Petra; Traube, Sebastian; Knöller, Kay; Wange, Martin; Fachmann, Stefan; Richnow, Hans H.

2012-05-01

264

Factors affecting indoor air concentrations of volatile organic compounds at a site of subsurface gasoline contamination  

Microsoft Academic Search

We report a field study of soil-gas transport of volatile organic compounds (VOCs) into a building at a site contaminated with gasoline. High VOC concentrations (30-60 g m⁻³) were measured in a soil gas 0.7 m below the building. Measured indoor air concentrations were nearly 10⁶ lower due to a sharp gradient in soil-gas VOC concentrations between 0.1 and 0.7

Marc L. Fischer; Abra J. Bentley; A. T. Hodgson; R. G. Sextro; J. M. Daisey; K. A. Dunkin; W. W. Nazaroff

1996-01-01

265

Rigorous Modeling of Contaminant Removal from the Subsurface by Soil Heating  

Microsoft Academic Search

Fully compositional and nonisothermal numerical simulators have found their way into Environmental Engineering. The research codes in use, e.g., Berkeley's Multicomponent Multiphase Nonisothermal Organics Transport Simulator, M2NOTS, are still user-hostile and, therefore, difficult to use by the uninitiated. Nevertheless, such codes are quite general and robust, and make it possible to model rigorously transport of several contaminants which can flow

Tadeus W. Patzek

1996-01-01

266

Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer.  

PubMed Central

In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with 14C-labeled organic compounds, and the evolution of 14CO2 was measured over time. Gas chromatographic analyses were used to monitor CO2 production and O2 consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. 14CO2 was measured from [14C]glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total [14C]glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of 14C label. [14C]benzene and [14C]toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO3, CO2 production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rate of 0.099 mumol g-1 (dry weight) day-1 while oxygen concentration decreased at a rate of 0.124 mumol g-1 (dry weight) day-1. With no added nitrate, CO2 production was not different from that in metabolically inhibited control vials. From the examination of selected components of JP-4, the n-alkane hexane appeared to be degraded as opposed to the branched alkanes of similar molecular weight. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Aelion, C M; Bradley, P M

1991-01-01

267

The plume fringe concept - Biodegradation of organic contaminants in subsurface ecosystems  

NASA Astrophysics Data System (ADS)

The biodegradation of organic pollutants in groundwater systems may be limited by the depletion of essential nutrients or the low number of degraders. However, the main problem seems to be the insufficient mixing of e-donors and e-acceptors. Main degradation activities in contaminant plumes are therefore located at their fringes. In order to investigate the ecology of pollutant-degrading microbes, experiments are carried out (1) in 2D-aquifer model systems and (2) sediment cores were drilled at a former gasworks site and a novel high-resolution multilevel sampling well was installed. (1) To assess the importance of individual abiotic (e.g. mixing, toxicity, nutrients) and biotic (e.g. cell distribution and activity, redox tolerance) parameters for biodegradation under well controlled lab conditions, contaminant plumes are generated in 2D-model systems and subsequently inoculated with aerobic and/or anaerobic bacterial strains to investigate biodegradation in a spatially resolved manner. (2) To recognize limitations of biodegradation in a PAH-contaminated aquifer, sediment cores were taken and, at the same site, a high-resolution multilevel well was installed for frequent groundwater sampling with varying spatial resolution (from cm to m range). In both systems, degradation of contaminants is followed by vertically resolved concentration measurements, compound-specific stable isotope (D/H, 13C/12C) analysis and the identification of signature metabolites. Physical-chemical gradients are resolved by means of microsensors and geochemical sediment and water analysis. The spatial distribution of microbial biomass, individual groups of microbes and the presence of functional genes coding for potential degradation activities are investigated using molecular tools. First results of the work, which is embedded in two current projects, will be discussed.

Meckenstock, R. U.; Griebler, C.; Anneser, B.; Winderl, C.; Bauer, R.; Lüders, T.; Kellermann, C.; Selesi, D.

2005-12-01

268

Fingerprinting of Gasoline and Coal Tar NAPL Volatile Hydrocarbons Dissolved in Groundwater  

Microsoft Academic Search

Accidental spills and chronic leaks of fuel oil or other hydrocarbon material (e.g., coal tar) often result in subsurface accumulation of nonaqueous phase liquid (NAPL), which can be a subsequent source of contamination in groundwater. Linking hydrocarbons in groundwater to a source NAPL has been difficult when using standard target analytes (e.g., BTEX) because of differences in partitioning properties of

Ted C. Sauer; Helder J. Costa

2003-01-01

269

Temporal and spatial changes of terminal electron-accepting processes in a petroleum hydrocarbon-contaminated aquifer and the significance for contaminant biodegradation  

Microsoft Academic Search

Identifying the predominant terminal electron-accepting processes (TEAPs) in contaminated groundwater is an important step in determining the fate of contaminants. Although petroleum hydrocarbons are most readily degraded under aerobic conditions it is apparent that degradation also occures on methanogenic, sulfate-reducing, ferric iron-reducing, and nitrate reducing conditions. Further, there is evidence that biodegradation rates depend on TEAPs. This paper examines the

Don A. Vroblesky; Francis H. Chapelle

1994-01-01

270

Radon in groundwater contaminated by dissolved hydrocarbons in Santa Bárbara d'Oeste, São Paulo State, Brazil.  

PubMed

This investigation reported the (222)Rn activity concentration and dissolved hydrocarbon content in groundwater collected in three gas stations where occurred tanks leaks, in Santa Barbara d'Oeste, São Paulo State, Brazil. The results indicated a tendency of correlation between the radon and BTEX, suggesting that the presence of dissolved hydrocarbons increase the radon concentration in water, due to the preferential partition at this phase. The radiometric data are useful for the detection of residual contamination and dissolved hydrocarbon plumes in groundwater, reinforcing the findings of previous studies held elsewhere. PMID:22885393

Galhardi, J A; Bonotto, D M

2012-07-14

271

Microbial Diversity and Bioremediation of a Hydrocarbon-Contaminated Aquifer (Vega Baja, Puerto Rico)  

SciTech Connect

Hydrocarbon contamination of groundwater resources has become a major environmental and human health concern in many parts of the world. Our objectives were to employ both culture and culture-independent techniques to characterize the dynamics of microbial community structure within a fluidized bed reactor used to bioremediate a diesel-contaminated groundwater in a tropical environment. Under normal operating conditions, 97 to 99% of total hydrocarbons were removed with only 14 min hydraulic retention time. Over 25 different cultures were isolated from the treatment unit (96% which utilized diesel constituents as sole carbon source). Approximately 20% of the isolates were also capable of complete denitrification to nitrogen gas. Sequence analysis of 16S rDNA demonstrated ample diversity with most belonging to the {infinity}, {beta} and {gamma} subdivision of the Proteobacteria, Bacilli, and Actinobacteria groups. Moreover, the genetic constitution of the microbial community was examined at multiple time points with a Functional Gene Array (FGA) containing over 12,000 probes for genes involved in organic degradation and major biogeochemical cycles. Total community DNA was extracted and amplified using an isothermal {phi}29 polymerase-based technique, labeled with Cy5 dye, and hybridized to the arrays in 50% formimide overnight at 50 C. Cluster analysis revealed comparable profiles over the course of treatment suggesting the early selection of a very stable microbial community. A total of 270 genes for organic contaminant degradation (including naphthalene, toluene [aerobic and anaerobic], octane, biphenyl, pyrene, xylene, phenanthrene, and benzene); and 333 genes involved in metabolic activities (nitrite and nitrous oxide reductases [nirS, nirK, and nosZ], dissimilatory sulfite reductases [dsrAB], potential metal reducing C-type cytochromes, and methane monooxygenase [pmoA]) were repeatedly detected. Genes for degradation of MTBE, nitroaromatics and chlorinated compounds were also present, indicating a broad catabolic potential of the treatment unit. FGA's demonstrated the early establishment of a diverse community with concurrent aerobic and anaerobic processes contributing to the bioremediation process.

Rodriguez-Martinex, Enid M. [University of Puerto Rico; Perez, Ernie [University of Puerto Rico; Schadt, Christopher Warren [ORNL; Zhou, Jizhong [University of Oklahoma; Massol-Deya, Arturo A. [University of Puerto Rico

2006-01-01

272

Microbial Diversity and Bioremediation of a Hydrocarbon-Contaminated Aquifer (Vega Baja, Puerto Rico)  

PubMed Central

Hydrocarbon contamination of groundwater resources has become a major environmental and human health concern in many parts of the world. Our objectives were to employ both culture and culture-independent techniques to characterize the dynamics of microbial community structure within a fluidized bed reactor used to bioremediate a diesel-contaminated groundwater in a tropical environment. Under normal operating conditions, 97 to 99% of total hydrocarbons were removed with only 14 min hydraulic retention time. Over 25 different cultures were isolated from the treatment unit (96% which utilized diesel constituents as sole carbon source). Approximately 20% of the isolates were also capable of complete denitrification to nitrogen gas. Sequence analysis of 16S rDNA demonstrated ample diversity with most belonging to the ?, ? and ? subdivision of the Proteobacteria, Bacilli, and Actinobacteria groups. Moreover, the genetic constitution of the microbial community was examined at multiple time points with a Functional Gene Array (FGA) containing over 12,000 probes for genes involved in organic degradation and major biogeochemical cycles. Total community DNA was extracted and amplified using an isothermal ?29 polymerase-based technique, labeled with Cy5 dye, and hybridized to the arrays in 50% formimide overnight at 50°C. Cluster analysis revealed comparable profiles over the course of treatment suggesting the early selection of a very stable microbial community. A total of 270 genes for organic contaminant degradation (including naphthalene, toluene [aerobic and anaerobic], octane, biphenyl, pyrene, xylene, phenanthrene, and benzene); and 333 genes involved in metabolic activities (nitrite and nitrous oxide reductases [nirS, nirK, and nosZ], dissimilatory sulfite reductases [dsrAB], potential metal reducing C-type cytochromes, and methane monooxygenase [pmoA]) were repeatedly detected. Genes for degradation of MTBE, nitroaromatics and chlorinated compounds were also present, indicating a broad catabolic potential of the treatment unit. FGA’s demonstrated the early establishment of a diverse community with concurrent aerobic and anaerobic processes contributing to the bioremediation process.

Rodriguez-Martinez, Enid M.; Perez, Ernie X.; Schadt, Christopher W.; Zhou, Jizhong; Massol-Deya, Arturo A.

2006-01-01

273

Microbial Diversity and Bioremediation of aHydrocarbon-Contaminated Aquifer (Vega Baja, Puerto Rico)  

SciTech Connect

Hydrocarbon contamination of groundwater resources hasbecome a major environmental and human health concern in many parts ofthe world. Our objectives were to employ both culture andculture-independent techniques to characterize the dynamics of microbialcommunity structure within a fluidized bed reactor used to bioremediate adiesel-contaminated groundwater in a tropical environment. Under normaloperating conditions, 97 to 99 percent of total hydrocarbons were removedwith only 14 min hydraulic retention time. Over 25 different cultureswere isolated from the treatment unit (96 percent which utilized dieselconstituents as sole carbon source). Approximately 20 percent of theisolates were also capable of complete denitrification to nitrogen gas.Sequence analysis of 16S rDNA demonstrated ample diversity with mostbelonging to the infinity, beta and gamma subdivision of theProteobacteria, Bacilli, and Actinobacteria groups. Moreover, the geneticconstitution of the microbial community was examined at multiple timepoints with a Functional Gene Array (FGA) containing over 12,000 probesfor genes involved in organic degradation and major biogeochemicalcycles. Total community DNA was extracted and amplified using anisothermal phi29 polymerase-based technique, labeled with Cy5 dye, andhybridized to the arrays in 50 percent formimide overnight at 50 degreesC. Cluster analysis revealed comparable profiles over the course oftreatment suggesting the early selection of a very stable microbialcommunity. A total of 270 genes for organic contaminant degradation(including naphthalene, toluene [aerobic and anaerobic], octane,biphenyl, pyrene, xylene, phenanthrene, and benzene); and 333 genesinvolved in metabolic activities (nitrite and nitrous oxide reductases[nirS, nirK, and nosZ], dissimilatory sulfite reductases [dsrAB],potential metal reducing C-type cytochromes, and methane monooxygenase[pmoA]) were repeatedly detected. Genes for degradation of MTBE,nitroaromatics and chlorinated compounds werealso present, indicating abroad catabolic potential of the treatment unit. FGA's demonstrated theearly establishment of a diverse community with concurrent aerobic andanaerobic processes contributing to the bioremediationprocess.

Rodriguez-Martinez, E.M.; Perez, Ernie X.; Schadt, ChristopherW.; Zhou, Jizhong; Massol-Deya, Arturo A.

2006-09-30

274

SMART 3D SUBSURFACE CONTAMINANT CHARACTERIZATION AT THE BGRR DEC OMMISSIONING PROJECT.  

SciTech Connect

The Brookhaven Graphite Research Reactor is currently on an accelerated decommissioning schedule with a completion date projected for 2005. The accelerated schedule combines characterization with removal actions for the various systems and structures. A major project issue involves characterization of the soils beneath contaminated Below Grade Ducts (BGD), the main air ducts connecting the exhaust plenums with the Fan House. The air plenums experienced water intrusion during BGRR operations and after shutdown. The water intrusions were attributed to rainwater leaks into degraded parts of the system, and to internal cooling water system leaks. If the characterization could provide enough information to show that soil contamination surrounding the BGD is either below cleanup guidelines or is very localized and can be ''surgically removed'' at a reasonable cost, the ducts may be decontaminated and left in place. This will provide significant savings compared to breaking up the 170-ft. long concrete duct, shipping the projected 9,000 m{sup 3} of waste off-site and disposing of it in an approved site. The focus of this Department of Energy Accelerated Site Technology Deployment (DOE ASTD) project was to determine the extent (location, type, and level) of soil contamination surrounding the BGD. A suite of innovative characterization tools was used to complete the characterization of the soil surrounding the BGD in a cost-effective and timely fashion and in a manner acceptable to the stakeholders. A state-of-the-art perfluorocarbon tracer (PFT) technology was used to screen the BGD for existing leak pathways and thus focus the characterization on potential contamination ''hot spots.'' Once pathways were identified, the sampling and analysis plan was designed to emphasize the leaking areas of the duct and perform only confirmatory checks in areas shown to be leak-free. A small-footprint Geoprobe{reg_sign} was used obtain core samples and allowed sampling in areas surrounding the BGD that were difficult to access. Two novel, field-deployed, radiological analysis systems (ISOCS and BetaScint{trademark}) were used to analyze the core samples and a three-dimensional (3-D) visualization system facilitated data analysis/interpretation for the stakeholders. All of the technologies performed as well or better than expected and the characterization could not have been completed in the same time or at the same cost without using this approach. A total of 904 BGD soil samples were taken, evaluated, and modeled. Results indicated that contamination was primarily located in discrete areas near several expansion joints and underground structures (bustles), but that much of the soil beneath and surrounding the BGD was clean of any radiological contamination. One-year project cost savings are calculated to be $1,254K. Life cycle cost savings, resulting from reduction in the number of samples and the cost of sample analysis, are estimated to be $2,162K. When added to potential cost savings associated with decontaminating and leaving the BGD in place ($7.1 to 8.1M), far greater overall savings may be realized.

HEISER,J.; KALB,P.; SULLIVAN,T.; MILIAN,L.

2002-08-04

275

Phytosiderophore Effects on Subsurface Actinide Contaminants: Potential for Phytostabilization and Phytoextraction  

SciTech Connect

This project seeks to determine the potential of phytosiderophore-producing plants for phytostabilization and phytoextraction of actinides and some metal soil contaminants. Phytosiderophores are secreted by graminaceous plants such as barley and wheat for the solubilization, mobilization and uptake of Fe and other essential nutrients from soils. The ability for these phytosiderophores to chelate and absorb actinides using the same uptake system as for Fe is hereby investigated though characterization of actinide-phytosiderophore complexes (independently of plants), and characterization of plant uptake of such complexes.

Ruggiero, Christy

2003-06-01

276

Polyphenol oxidase activity in subcellular fractions of tall fescue contaminated by polycyclic aromatic hydrocarbons.  

PubMed

Understanding enzyme responses to contamination with persistent organic pollutants (POPs) is a key step in the elucidation of POP metabolic mechanisms in plants. However, there is little information available on enzyme activity in subcellular fractions of POP-contaminated plants. To our knowledge, this is the first study to investigate the activities of polyphenol oxidase (PPO) in cell fractions of plants under contamination stress from polycyclic aromatic hydrocarbons (PAHs) using a greenhouse batch technique. Three parameters, E(cell), E(cell-n), and P(cell), denoting the amount of PPO activity, cell fraction content-normalized PPO activity, and proportion of PPO activity in each cell fraction, respectively, were used in this study. Contamination with phenanthrene, as a representative PAH, at a relatively high level (>0.23 mg L?¹) in culture solution generally stimulated PPO activity in tall fescue (Festuca arundinacea Schreb.) roots and shoots and their cellular fractions. The amount and distribution proportion of PPO activity in each cell fraction of phenanthrene-contaminated roots and shoots were (in descending order): cell solution > > cell wall > cell organelles. Cell solution was the dominant storage domain of PPO activity and contributed 84.0 and 82.8% of PPO activity in roots and shoots, respectively. The cell wall had the highest density of PPO activity in roots and shoots, based on the highest cell fraction content normalized PPO activity in this cell fraction. Our results provide new information on enzyme responses in plant intracellular fractions to xenobiotic POPs and fundamental information on within-plant POP metabolic mechanisms. PMID:22565262

Ling, Wanting; Lu, Xiaodan; Gao, Yanzheng; Liu, Juan; Sun, Yandi

277

In situ detection of anaerobic alkane metabolites in subsurface environments.  

PubMed

Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments. PMID:23761789

Agrawal, Akhil; Gieg, Lisa M

2013-06-04

278

The effect of subsurface military detonations on vadose zone hydraulic conductivity, contaminant transport and aquifer recharge.  

PubMed

Live fire military training involves the detonation of explosive warheads on training ranges. The purpose of this experiment is to evaluate the hydrogeological changes to the vadose zone caused by military training with high explosive ammunition. In particular, this study investigates artillery ammunition which penetrates underground prior to exploding, either by design or by defective fuze mechanisms. A 105 mm artillery round was detonated 2.6 m underground, and hydraulic conductivity measurements were taken before and after the explosion. A total of 114 hydraulic conductivity measurements were obtained within a radius of 3m from the detonation point, at four different depths and at three different time periods separated by 18months. This data was used to produce a three dimensional numerical model of the soil affected by the exploding artillery round. This model was then used to investigate potential changes to aquifer recharge and contaminant transport caused by the detonating round. The results indicate that an exploding artillery round can strongly affect the hydraulic conductivity in the vadose zone, increasing it locally by over an order of magnitude. These variations, however, appear to cause relatively small changes to both local groundwater recharge and contaminant transport. PMID:23353636

Lewis, Jeffrey; Burman, Jan; Edlund, Christina; Simonsson, Louise; Berglind, Rune; Leffler, Per; Qvarfort, Ulf; Thiboutot, Sonia; Ampleman, Guy; Meuken, Denise; Duvalois, Willem; Martel, Richard; Sjöström, Jan

2012-12-30

279

Phototoxic response of Lumbriculus variegatus to sediments contaminated by polycyclic aromatic hydrocarbons  

SciTech Connect

The toxicity of certain polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms can be greatly increased upon exposure of the organisms to ultraviolet (UV) radiation present in sunlight. The phenomenon of photoactivation of PAHs had received some attention in the laboratory; however, evaluation of the photoinduced toxicity of PAHs in field settings has been limited. In these studies, in situ chambers made from Pyrex{reg_sign} glass tubes were used to evaluate the phototoxic response of laboratory-cultured oligochaetes (Lumbriculus variegatus) in sediments contaminated with PAHs. These experiments were conducted using both sunlight-exposed and shaded test chambers. In addition to the PAH-contaminated site, a reference site lacking PAHs was tested as a control. Survival of L. variegatus at the PAH-contaminated site was significantly less in chambers exposed to sunlight than in chambers held in the dark, or chambers from the reference site. Concurrent laboratory studies with sediment collected from the two sites and an artificial source of UV light corroborated observations made in the field. Although a number of PAHs were present at elevated concentrations in the test sample, further work is required to determine exactly which were responsible for the observed phototoxicity.

Monson, P.D. [Univ. of Wisconsin-Superior, Duluth, MN (United States); Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States); Kosian, P.A. [Integrated Lab. Systems, Duluth, MN (United States)

1995-05-01

280

Evidence for syntrophic butyrate metabolism under sulfate-reducing conditions in a hydrocarbon-contaminated aquifer.  

PubMed

The importance of syntrophy in the degradation of butyrate in an aquifer where sulfate reduction was shown to be an important terminal electron-accepting process was assessed. Hydrocarbon-contaminated aquifer sediments coupled butyrate degradation to sulfate reduction and methane production. Butyrate degradation in methanogenic microcosms was inhibited by the addition of 2-bromoethanesulfonic acid, and was restored by the addition of 10 mM sulfate and a hydrogen- and formate-using sulfate reducer, but not by the addition of 10 mM sulfate alone. Molybdate addition inhibited butyrate degradation in sulfate-reducing microcosms. The addition of CO, which inhibits hydrogenases, to sulfate-reducing microcosms inhibited butyrate metabolism and caused the hydrogen partial pressure to increase to levels that would make syntrophic butyrate degradation via sulfate reduction energetically unfavorable (-5 to +3 kJ mol(-1) ). DNA extracted from the most probable number cultures and contaminated sediments contained sequences related to members of the families Syntrophomonadaceae and Syntrophaceae, whose members are known to syntrophically degrade fatty acids, as well as sequences related to uncultured Firmicutes, Desulfobulbaceae, Desulfobacteriaceae, and Desulfovibrionaceae. These data show that contaminated sediments degraded butyrate syntrophically coupled to methane production and sulfate reduction. PMID:21223338

Struchtemeyer, Christopher G; Duncan, Kathleen E; McInerney, Michael J

2011-02-01

281

Role of Autochthonous Filamentous Fungi in Bioremediation of a Soil Historically Contaminated with Aromatic Hydrocarbons  

PubMed Central

Nine fungal strains isolated from an aged and heavily contaminated soil were identified and screened to assess their degradative potential. Among them, Allescheriella sp. strain DABAC 1, Stachybotrys sp. strain DABAC 3, and Phlebia sp. strain DABAC 9 were selected for remediation trials on the basis of Poly R-478 decolorization associated with lignin-modifying enzyme (LME) production. These autochthonous fungi were tested for the abilities to grow under nonsterile conditions and to degrade various aromatic hydrocarbons in the same contaminated soil. After 30 days, fungal colonization was clearly visible and was confirmed by ergosterol determination. In spite of subalkaline pH conditions and the presence of heavy metals, the autochthonous fungi produced laccase and Mn and lignin peroxidases. No LME activities were detected in control microcosms. All of the isolates led to a marked removal of naphthalene, dichloroaniline isomers, o-hydroxybiphenyl, and 1,1?-binaphthalene. Stachybotrys sp. strain DABAC 3 was the most effective isolate due to its ability to partially deplete the predominant contaminants 9,10-anthracenedione and 7H-benz[DE]anthracen-7-one. A release of chloride ions was observed in soil treated with either Allescheriella sp. strain DABAC 1 or Stachybotrys sp. strain DABAC 3, suggesting the occurrence of oxidative dehalogenation. The autochthonous fungi led to a significant decrease in soil toxicity, as assessed by both the Lepidium sativum L. germination test and the Collembola mortality test.

D'Annibale, A.; Rosetto, F.; Leonardi, V.; Federici, F.; Petruccioli, M.

2006-01-01

282

Biological remediation of polynuclear aromatic hydrocarbon contaminated soils using Acinetobacter sp.  

SciTech Connect

Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites has been attempted using various methods such as solvent washing, air stripping, incineration, composting, electrokinetic remediation, and supercritical extraction. However, applicability of these physical, chemical, and biological treatment methods or their combination is critically dependent on soil characteristics, nature and level of contamination, site specifications, and economic feasibility, to name a few. Present research is aimed at studying the applicability of biological treatment for decontamination of industrial soil containing PAHs. The current preliminary study included soil analysis, contaminant characterization, and soil treatment using Acinetobacter sp. The soil treatment over a 5-week period, with minimal supplemental nutrient addition, showed removal efficiencies of 80% and more. The effect of initial microbial population in soil on the removal efficiency over a 5-week treatment period was studied. Experiments were designed to compare the removal efficiencies occurring in packed beds versus continuously-stirred tank reactor (CSTR)-type fermentation conditions. This also estimated a conservative range of decontamination efficiencies achievable using minimal control.

Joshi, M.M.; Lee, S. [Univ. of Akron, OH (United States)

1996-03-01

283

Determination of leaching behaviour of polycyclic aromatic hydrocarbons from contaminated soil by column leaching test.  

PubMed

Column leaching tests become increasingly important for assessing the risk of release of pollutants from a wide variety of solid materials into water. In this study a column leaching test was designed to provide insight into the fate of selected polycyclic aromatic hydrocarbons (PAHs) in soils and their leaching behaviour. The results showed relatively high initial concentrations of naphthalene, anthracene, and pyrene for column B2. Two proportions of contaminated soil (5 and 20%) used in the columns yielded different leaching behaviour. Different contact time applied in columns B1 and B2 affected the initial amounts of leached PAHs. Results indicated that the distribution pattern of PAH compounds in solid phase considerably affected leached concentrations of PAHs. Released amounts of PAH compounds decreased with increasing molecular size, or rather the hydrophobicity of the compound. The effect of dissolved organic carbon on PAH leaching was also investigated in this study. The mobilization of colloids did not show any significant effect on leached concentrations of PAH compounds. Approximately 4.6 and 2.2% of the total initial amounts of studied PAHs in the soil were leached in columns B1 and B2, respectively. Therefore high PAH concentrations in the solid phase does not imply serious groundwater contamination risk during a leaching event (e.g. raining) and significant amount of contaminants may stay in the soil layer for a long time and do not leach down into groundwater. PMID:19942646

Zand, Ali Daryabeigi; Grathwohl, Peter; Nabibidhendi, Gholamreza; Mehrdadi, Nasser

2009-11-26

284

Chemical Fate of Contaminants in the Environment: Chlorinated Hydrocarbons in the Groundwater  

SciTech Connect

Chlorinated hydrocarbons (CHCs) are the most common contaminant found at hazardous waste sites and are the most prevalent contaminants on U.S. Department of Energy (DOE) weapons production sites. Many of the CHCs are either known or suspected carcinogens and thus pose health risks to the public and/or site workers. Unlike simple hydrocarbons, CHCs are resistant to biodegradation, but can degrade by abiotic processes such as hydrolysis, nucleophilic substitution, and dehydrochlorination. Unfortunately, few studies of the reactions of chlorinated hydrocarbons have been reported in literature, and disagreement still exists about the mechanisms and rates of many of the key reactions. In this work, we modeled the reactions involved in the degradation of CHCs in the groundwater. The goals of the research proposed are: • development of a computational approach that will allow reaction pathways and rate constants to be accurately calculated • development of more approximate approaches, evaluated against the more accurate approach, which will lay the groundwork for exploratory studies of more complex CHCs • application of these approaches to study the degradation pathways of CHCs in aqueous liquids • application of the more approximate approaches to study the mechanism of forming complex CHC polychlorinated benzene compounds and dioxins. We examined elementary reactions involved in the aqueous-phase chemistry of chlorinated methanes and ethylenes in an attempt to obtain a detailed understanding of the abiotic processes involved in the degradation of this important class of contaminants. We began by studying the reactions of CHnCl(4-n) and C2HnCl(4-n) with OH¯, as these are thought to be the dominant processes involved in the degradation of these chlorinated species. We used state-of-the-art theoretical techniques to model the elementary reactions of CHCs important in the groundwater. We employed high-accuracy electronic structure methods (e.g., perturbation theory and coupled cluster methods with correlation-consistent basis sets) to determine the energies of the various stable species, intermediates, and transition states involved in the elementary reactions of CHCs. Effects of solvation on the reaction energetics were studied by including small numbers of solvent molecules (microsolvation). Our own N-layered molecular orbital + molecular mechanics (ONIOM) method was used because it allows the number of solvent molecules to be increased, and hybrid quantum mechanical/molecular mechanics (QM/MM) methods and continuum solvation models were used to estimate the effects of bulk solvation. Rate constants for the gas-phase, microsolvated, and bulk-phase reactions were computed using variational transition state theory (VTST).

Truhlar, Donald G.; Cramer, Christopher; Gao, Jiali; Garrett, Bruce C.; Dupuis, Michel; Straatsma, TP; Morokuma, Keiji; Dunning, Thomas H.; Borisov, Yurii A.; Arcia, Edgar E.; Thompson, Jacob S.

2006-09-21

285

Methods for characterizing subsurface volatile contaminants using in-situ sensors  

DOEpatents

An inverse analysis method for characterizing diffusion of vapor from an underground source of volatile contaminant using data taken by an in-situ sensor. The method uses one-dimensional solutions to the diffusion equation in Cartesian, cylindrical, or spherical coordinates for isotropic and homogenous media. If the effective vapor diffusion coefficient is known, then the distance from the source to the in-situ sensor can be estimated by comparing the shape of the predicted time-dependent vapor concentration response curve to the measured response curve. Alternatively, if the source distance is known, then the effective vapor diffusion coefficient can be estimated using the same inverse analysis method. A triangulation technique can be used with multiple sensors to locate the source in two or three dimensions. The in-situ sensor can contain one or more chemiresistor elements housed in a waterproof enclosure with a gas permeable membrane.

Ho, Clifford K. (Albuquerque, NM)

2006-02-21

286

Comparison of Fenton's Reagent and Ozone Oxidation of Polycyclic Aromatic Hydrocarbons in Aged Contaminated Soils (7 pp)  

Microsoft Academic Search

Background, Aim and Scope  \\u000a Polycyclic aromatic hydrocarbons (PAHs) are formed as a result of incomplete combustion and are among the most frequently\\u000a occurring contaminants in soils and sediments. PAHs are of great environmental concern due to their ubiquitous nature and\\u000a toxicological properties. Consequently, extensive research has been conducted into the development of methods to remediate\\u000a soils contaminated with PAHs. Fenton's

Bert van Bavel; Ylva Persson; Sofia Frankki; Staffan Lundstedt; Peter Haglund; Mats Tysklind

2006-01-01

287

Biological degradation of selected hydrocarbons in an old PAH\\/creosote contaminated soil from a gas work site  

Microsoft Academic Search

An old PAH\\/creosote contaminated soil (total ?300??g PAH\\/g soil) from a former gas work site in Stockholm, Sweden, has been\\u000a treated at 20?°C with the addition of various nutrients and inoculated with bacteria (isolated from the soil) to enhance the\\u000a degradation of selected hydrocarbons. Microcosm studies showed that the soil consisted of two contaminant fractions: one available,\\u000a easily degraded fraction

M. Eriksson; G. Dalhammar; A.-K. Borg-Karlson

2000-01-01

288

Method for determining the presence of hydrocarbons in subsurface geological formations by comparative assessment of compressional and shear wave reflection data  

SciTech Connect

This paper describes a method for determining the presence of hydrocarbons in subsurface geological formations by comparative assessment of acquired compressional wave reflection information and pseudoshear wave reflection information estimated from acquired compressional wave reflection information. It comprises the steps of: generating descending acoustic compressional waves from a plurality of acoustic wave sources and receiving and recording at a plurality of receivers ascending compressional wave reflection information produced at a subsurface interface; gathering the recorded compressional wave reflection information into sets of different source-receiver offsets having a common reflection boundary; correcting gathered compressional wave reflection information for normal moveout; measuring amplitudes of gathered compressional wave reflection information at given points in time for different source-receiver offset value; determining directly from the measured amplitude offset values pseudoshear wave reflection information, selecting compressional wave reflection information; selecting produced pseudoshear wave reflection information; combining selected compressional wave reflection information and selected pseudoshear wave reflection information according to the relation R/sub s/-R/sub s/, where R/sub p/ is the selected compressional wave reflection information and Rs is the selected pseudoshear wave reflection information; and comparing the combined wave reflection information to the selected compressional wave reflection information.

Goins, N.R.

1989-08-15

289

Petroleum hydrocarbon contamination in Nelson Lagoon, Alaska, sampling three different matrices.  

PubMed

Polycyclic aromatic hydrocarbon (PAH) levels were measured in sediments, bivalves and semi-permeable membrane devices (SPMDs) in the relatively pristine marine environment of Nelson Lagoon, Alaska. Most PAH levels in Nelson Lagoon were low, and similar to global background concentrations. Sampling media type can significantly influence conclusions of PAH contamination in the environment. Concentration of a broad size range of PAHs was observed in the tissues of blue mussels (Mytilus edulis). SPMDs collected some two- to three-ring PAHs from the dissolved water phase, while sediments collected five- to six-ring PAHs that were likely adsorbed onto particulate matter. Benzo(a)pyrene, a potent carcinogen, was found in mussels at levels similar to more industrialized harbors in Alaska. PMID:22901960

Lance, Ellen W; Matz, Angela C; Reeves, Mari K; Verbrugge, Lori A

2012-08-14

290

Contaminated soil phytoremediation by Cyperus laxus Lam. cytochrome p450 EROD-activity induced by hydrocarbons in roots.  

PubMed

Laboratory and greenhouse experiments with Cyperus laxus Lam were conducted to determine the rate and extent of phytoremediation and the effect of hydrocarbons on the cytochrome P450 EROD (7-ethoxyresorufin-O-deethylase) enzymatic activity in roots. Plants were cultivated on hydrocarbon-contaminated soil (HCS) and spiked perlite. Phytoremediation was evaluated using 6.5 kg HCS (173 +/- 15 mg total petroleum hydrocarbons [TPH] g(-1) of dry soil) pots at different moisture contents; the average removal rate was 3.46-0.25 mg TPH g(-1) dry soil month(-1) and 48% was removed when moisture was kept at 60%. The aromatic hydrocarbon fraction was the mostly removed, 60%; aliphatic, 51%; and polar 24% after 24-month experiments. In unplanted pots, TPH concentration did not exhibit significant differences with respect to the initial concentration. We confirmed that the presence of hydrocarbons induced ERODactivity up to 6.5-fold. Moreover, short-term experiments (up to 13 d) with spiked perlite demonstrated that two EROD activities in roots contributed to the total detected; 60% was found in the cytosolic and 40% in the microsomal fraction. To our knowledge, this is the first work that tries to build links between the hydrocarbon-inducible character of ERODactivity in roots and the phytoremediation ability of C. laxus in highly contaminated soils. PMID:19260214

López-Martínez, S; Gallegos-Martínez, M E; Pérez-Flores, L J; Gutiérrez-Rojas, M

291

Changes in toxicity during in situ bioremediation of weathered drill wastes contaminated with petroleum hydrocarbons.  

PubMed

Bioremediation of weathered drill wastes severely contaminated with total petroleum hydrocarbons (TPH) (90,000-170,000 mg kg(-1)) and BTEX (51.2-95.5 mg kg(-1)) to soil standards was achieved over a 3-year period in three phases: initial remediation, basic bioremediation and inoculation with a biopreparation. Fourteen non-pathogenic indigenous bacteria species belonging mainly to the Actinomycetales were identified and shown to be able to degrade 63-75% of nC(9)-nC(20), 36-51% of nC(21)-nC(36), 36% of BTEX and 20% of PAHs (polycyclic aromatic hydrocarbons). Addition of five non-pathogenic fungi species to the bacterial consortium allowed degradation of 69-89% of nC(9)-nC(20), 47-80% of nC(21)-nC(36), 76% of BTEX, and 68% of PAHs. Microtox, Ostacodtoxkit, Phytotoxkit and Ames tests indicated that changes in toxicity were not connected with the decrease in TPH contents, possibly due to the formation of toxic indirect metabolites during bioremediation. No toxicity was found in the soil after bioremediation. PMID:23018157

Steliga, Teresa; Jakubowicz, Piotr; Kapusta, Piotr

2012-09-05

292

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

SciTech Connect

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

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

1998-06-01

293

Factors Affecting Indoor Air Concentrations of Volatile Organic Compounds at a Site of Subsurface Gasoline Contamination  

SciTech Connect

We report a field study of soil gas transport of volatile organic compounds (VOCs) into a slab-on-grade building found at a site contaminated with gasoline. Although the high VOC concentrations (30-60 g m{sup -3}) measured in the soil gas at depths of 0.7 m below the building suggest a potential for high levels of indoor VOC, the measured indoor air concentrations were lower than those in the soil gas by approximately six orders of magnitude ({approx} 0.03 mg m{sup -3}). This large ratio is explained by (1) the expected dilution of soil gas entering the building via ambient building ventilation (a factor of {approx}1000), and (2) an unexpectedly sharp gradient in soil gas VOC concentration between the depths of 0.1 and 0.7 m (a factor of {approx}1000). Measurements of the soil physical and biological characteristics indicate that a partial physical barrier to vertical transport in combination with microbial degradation provides a likely explanation for this gradient. These factors are likely to be important to varying degrees at other sites.

Fischer, M.L.; Bentley, A.J.; Dunkin, K.A.; Hodgson, A.T.; Nazaroff, W.W.; Sextro, R.G.; Daisey, J.M.

1995-11-01

294

Environmental effects of dredging. Literature review for residue-effects relationships with hydrocarbon contaminants in marine organisms. Technical note  

SciTech Connect

The purpose of this literature review was to identify potential residue-effects relationships involving hydrocarbon contaminants which are described in the scientific literature. That information will be used to develop guidance for interpreting the results of bioaccumulation experiments conducted in the regulatory evaluation of dredged material.

NONE

1990-12-01

295

Polycyclic aromatic hydrocarbons in agricultural soils in Poland: preliminary proposals for criteria to evaluate the level of soil contamination  

Microsoft Academic Search

The contamination of agricultural soils in the Upper Silesia region of Poland with polycyclic aromatic hydrocarbons (PAH) was evaluated on the basis of three criteria: the sum of PAH content; the number of exceeded reference values for individual PAH (according Dutch regulations); the author's preliminary proposals for agricultural lands in Poland (the sum of PAH content normalized to “average soil”

Barbara Maliszewska-Kordybach

1996-01-01

296

Effect of soil structure on the bioavailability of polycyclic aromatic hydrocarbons within aggregates of a contaminated soil  

Microsoft Academic Search

Biodegradation of polycyclic aromatic hydrocarbon (PAH) was investigated in the whole matrix and in the different aggregate size fractions of a sandy soil contaminated by a mixture of 8 PAHs and incubated at water holding capacity. The distribution of PAHs and of phenanthrene-degrading bacteria were determined in the bulk soil and in 4 size aggregate fractions corresponding to sand, coarse

N Amellal; J.-M Portal; J Berthelin

2001-01-01

297

Bioremediation and Biodegradation Biodegradation of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Beach Sediments Treated with Nutrient Amendments  

Microsoft Academic Search

dition, PAHs are thermodynamically stable since they are derivatives of the benzene ring with large negative Microbial biodegradation of polycyclic aromatic hydrocarbons resonance energies (Mueller et al., 1996). As a result, (PAHs) during the process of bioremediation can be constrained by PAHs are recalcitrant in the environment and are often lack of nutrients, low bioavailability of the contaminants, or scarcity

Ran Xu; Jeffrey P. Obbard

298

Chlorinated Hydrocarbon Contamination in Osprey Eggs and Nestlings from the Canadian Great Lakes Basin, 1991–1995  

Microsoft Academic Search

Populations of osprey (Pandion haliaetus) in the Great Lakes basin declined dramatically during the 1950s–1970s due largely to adverse effects of persistent chlorinated hydrocarbons, ingested in their fish prey, on eggshell thickness and adult survival. Nevertheless, these contaminants were not measured in osprey tissues during the decades of decline on the Canadian Great Lakes. Between 1991 and 1995, we monitored

Pamela A. Martin; Shane R. De Solla; Peter Ewins

2003-01-01

299

The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon  

Microsoft Academic Search

A recent conceptual model links higher bulk conductivities at hydrocarbon impacted sites to higher total dissolved solids (TDS) resulting from enhanced mineral weathering due to acids produced during biodegradation. In this study, we evaluated the above model by investigating the vertical distribution of bulk conductivity, TDS, and specific conductance in groundwater. The results showed higher TDS at contaminated locations consistent

Eliot A. Atekwana; Estella A. Atekwana; Rebecca S. Rowe; D. Dale Werkema; Franklyn D. Legall

2004-01-01

300

The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon  

Microsoft Academic Search

A recent conceptual model links higher bulk conductivities at hydrocarbon impacted sites to higher total dissolved solids (TDS) resulting from enhanced mineral weathering due to acids produced during biodegradation. In this study, we evaluated the above model by investigating the vertical distribution of bulk conductivity, TDS, and specific conductance in groundwater. The results showed higher TDS at contaminated locations consistent

Eliot A. Atekwanaa; Estella A. Atekwanaa; Rebecca S. Roweb; D. Dale; Franklyn D. Legalld

301

The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon  

Microsoft Academic Search

Abstract A recent conceptual model links higher bulk conductivities at hydrocarbon,impacted sites to higher total dissolved solids (TDS) resulting from enhanced mineral weathering due to acids produced during biodegradation. In this study, we evaluated the above model by investigating the vertical distribution of bulk conductivity, TDS, and specific conductance in groundwater. The results showed higher TDS at contaminated locations consistent

Eliot A. Atekwana; Estella A. Atekwana; Rebecca S. Rowe; D. Dale Werkema; Franklyn D. Legall

2004-01-01

302

Role of plasmid in diesel oil degradation by yeast species isolated from petroleum hydrocarbon-contaminated soil  

Microsoft Academic Search

Five yeast species, namely Candida tropicalis, Cryptococcus laurentii, Trichosporon asahii, Rhodotorula mucilaginosa and Candida rugosa isolated from hydrocarbon-contaminated soil were found to be potent degraders of diesel oil. These microorganisms showed the presence of enzymes cytochrome P450, NADPH cytochrome c reductase, aminopyrine N demethylase, alcohol dehydrogenase, aldehyde dehydrogenase, naphthalene dioxygenase, catalase and glutathione S transferase when the cells were incubated

Preethy Chandran; Nilanjana Das

2012-01-01

303

Role of plasmid in diesel oil degradation by yeast species isolated from petroleum hydrocarbon-contaminated soil  

Microsoft Academic Search

Five yeast species, namely Candida tropicalis, Cryptococcus laurentii, Trichosporon asahii, Rhodotorula mucilaginosa and Candida rugosa isolated from hydrocarbon-contaminated soil were found to be potent degraders of diesel oil. These microorganisms showed the presence of enzymes cytochrome P450, NADPH cytochrome c reductase, aminopyrine N demethylase, alcohol dehydrogenase, aldehyde dehydrogenase, naphthalene dioxygenase, catalase and glutathione S transferase when the cells were incubated

Preethy Chandran; Nilanjana Das

2011-01-01

304

Investigation of microbes in the rhizosphere of selected trees for the rhizoremediation of hydrocarbon-contaminated soils.  

PubMed

Hydrocarbon-degrading microorganisms (HDMs), associated with the rhizosphere of Conocarpus lancifolius and Ficus infectoria trees grown in bioremediated soil, were isolated under controlled laboratory conditions. The selected trees were used to phytoremediate oil-contaminated soil for three successive growing seasons. At the end of the phytoremediation experiment, 85.7% of measurable total petroleum hydrocarbon was degraded in the rhizosphere soil associated with Conocarpus lancifolius compared to 78.6% in the rhizosphere of Ficus infectoria. The detectable concentrations of some polyaromatic hydrocarbons were less than 0.02 ppm. The HDM isolation process was conducted at 35 degrees C under aerobic conditions. The isolated HDMs were identified using 16S rRNA gene sequencing and fatty acid methyl ester analysis. Differences in the genera of the isolated HDMs and their assessed efficiency in degrading a mixture of hydrocarbon compounds between the two trees were noted. PMID:19260216

Yateem, A; Al-Sharrah, T; Bin-Haji, A

305

Development of a multistrain bacterial bioreporter platform for the monitoring of hydrocarbon contaminants in marine environments.  

PubMed

Petroleum hydrocarbons are common contaminants in marine and freshwater aquatic habitats, often occurring as a result of oil spillage. Rapid and reliable on-site tools for measuring the bioavailable hydrocarbon fractions, i.e., those that are most likely to cause toxic effects or are available for biodegradation, would assist in assessing potential ecological damage and following the progress of cleanup operations. Here we examined the suitability of a set of different rapid bioassays (2-3 h) using bacteria expressing the LuxAB luciferase to measure the presence of short-chain linear alkanes, monoaromatic and polyaromatic compounds, biphenyls, and DNA-damaging agents in seawater after a laboratory-scale oil spill. Five independent spills of 20 mL of NSO-1 crude oil with 2 L of seawater (North Sea or Mediterranean Sea) were carried out in 5 L glass flasks for periods of up to 10 days. Bioassays readily detected ephemeral concentrations of short-chain alkanes and BTEX (i.e., benzene, toluene, ethylbenzene, and xylenes) in the seawater within minutes to hours after the spill, increasing to a maximum of up to 80 muM within 6-24 h, after which they decreased to low or undetectable levels. The strong decrease in short-chain alkanes and BTEX may have been due to their volatilization or biodegradation, which was supported by changes in the microbial community composition. Two- and three-ring PAHs appeared in the seawater phase after 24 h with a concentration up to 1 muM naphthalene equivalents and remained above 0.5 muM for the duration of the experiment. DNA-damage-sensitive bioreporters did not produce any signal with the oil-spilled aqueous-phase samples, whereas bioassays for (hydroxy)biphenyls showed occasional responses. Chemical analysis for alkanes and PAHs in contaminated seawater samples supported the bioassay data, but did not show the typical ephemeral peaks observed with the bioassays. We conclude that bacterium-based bioassays can be a suitable alternative for rapid on-site quantitative measurement of hydrocarbons in seawater. PMID:20000678

Tecon, Robin; Beggah, Siham; Czechowska, Kamila; Sentchilo, Vladimir; Chronopoulou, Panagiota-Myrsini; McGenity, Terry J; van der Meer, Jan Roelof

2010-02-01

306

Activity and Diversity of Methanogens in a Petroleum Hydrocarbon-Contaminated Aquifer  

PubMed Central

Methanogenic activity was investigated in a petroleum hydrocarbon-contaminated aquifer by using a series of four push-pull tests with acetate, formate, H2 plus CO2, or methanol to target different groups of methanogenic Archaea. Furthermore, the community composition of methanogens in water and aquifer material was explored by molecular analyses, i.e., fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes amplified with the Archaea-specific primer set ARCH915 and UNI-b-rev, and sequencing of DNA from dominant DGGE bands. Molecular analyses were subsequently compared with push-pull test data. Methane was produced in all tests except for a separate test where 2-bromoethanesulfonate, a specific inhibitor of methanogens, was added. Substrate consumption rates were 0.11 mM day?1 for methanol, 0.38 mM day?1 for acetate, 0.90 mM day?1 for H2, and 1.85 mM day?1 for formate. Substrate consumption and CH4 production during all tests suggested that at least three different physiologic types of methanogens were present: H2 plus CO2 or formate, acetate, and methanol utilizers. The presence of 15 to 20 bands in DGGE profiles indicated a diverse archaeal population. High H2 and formate consumption rates agreed with a high diversity of methanogenic Archaea consuming these substrates (16S rRNA gene sequences related to several members of the Methanomicrobiaceae) and the detection of Methanomicrobiaceae by using FISH (1.4% of total DAPI [4?,6-diamidino-2-phenylindole]-stained microorganisms in one water sample; probe MG1200). Considerable acetate consumption agreed with the presence of sequences related to the obligate acetate degrader Methanosaeata concilii and the detection of this species by FISH (5 to 22% of total microorganisms; probe Rotcl1). The results suggest that both aceticlastic and CO2-type substrate-consuming methanogens are likely involved in the terminal step of hydrocarbon degradation, while methanogenesis from methanol plays a minor role. DGGE profiles further indicate similar archaeal community compositions in water and aquifer material. The combination of hydrogeological and molecular methods employed in this study provide improved information on the community and the potential activity of methanogens in a petroleum hydrocarbon-contaminated aquifer.

Kleikemper, Jutta; Pombo, Silvina A.; Schroth, Martin H.; Sigler, William V.; Pesaro, Manuel; Zeyer, Josef

2005-01-01

307

Bioavailability of polycyclic aromatic hydrocarbons from a historically contaminated sediment core  

SciTech Connect

To determine changes in bioavailability of selected polycyclic aromatic hydrocarbons (PAHs) with sediment aging, Lumbriculus variegatus were exposed for 4 weeks to sediment core sections taken from a contaminated lake. Core depths included surficial (0 to 4 cm), 4- to 8-, 12- to 16-, 28- to 32-, and 44- to 48-cm sections deposited for approximately 1899 to 1993, and were known to be historically contaminated with PAHs. Bioaccumulation was maximal at the 12- to 16-cm depth (circa 1967) where sediment PAH concentrations were greatest. Accumulation was generally below detection limits in the 0- to 4-cm depths, even though sediment concentrations of some compounds were comparable to those at the 12- to 16-cm depth where accumulation was great enough to generate accurate kinetics curves. Accumulation peaked at about 96 h, then declined over the remainder of the study for the lower-molecular-weight PAHs. For most higher-molecular-weight PAHs, accumulation peaked at about 2 weeks, then declined only slightly after 4 weeks. The differential bioavailability observed between surficial and at-depth core sections raises questions concerning the adequacy of results generated from toxicity and bioaccumulation tests routinely conducted surficial sediments.

Harkey, G.A.; Van Hoof, P.L.; Landrum, P.F. [Great Lakes Environmental Research Lab., Ann Arbor, MI (United States)

1995-09-01

308

Application of aqueous saponin on the remediation of polycyclic aromatic hydrocarbons-contaminated soil.  

PubMed

The aim of this research was to evaluate the feasibility of aqueous saponin for the removal and biodegradation of polycyclic aromatic hydrocarbons (PAHs) from contaminated soil. Dissolution test confirmed the ability of saponin to increase the apparent solubility of the tested 3-5 rings PAH above the critical micelle concentration (approximately 1000 mg/L). Microbial test with pure culture of Sphingomonas sp. showed that saponin significantly enhanced the degradation of pyrene. For example, the percent degradation was 2.1 times higher in the presence of 2500 mg/L saponin than that of control without saponin after 60 hours incubation at around 10(8) CFU/mL initial cell loading. These results suggest that the binding of pyrene with saponin does not pose a serious constraint to bacterial uptake. Contrary to pyrene, saponin was chemically stable against the PAHs degrader. It is also not toxic to the cell at least up to 2500 mg/L. Finally, using a spiked soil sample, extraction tests with 10,000 mg/L of saponin showed that around 52.7% and 0.3% of pyrene was removed from low and high organic spiked soils, respectively. The results from this study indicate that aqueous saponin is appropriate as a washing agent as well as biodegradation enhancer for the detoxification of PAHs-contaminated low organic carbon soil. PMID:22506706

Kobayashi, Takayuki; Kaminaga, Hirohisa; Navarro, Ronald R; Iimura, Yosuke

2012-01-01

309

Polycyclic aromatic hydrocarbon contamination in marine sediments near Kitimat, British Columbia  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs), like many other hydrophobic organic contaminants, are rapidly sorbed to particles and incorporated within sediments in aquatic systems. The PAH composition within the sediments reflects the source(s) from which the PAHs were derived. However, the ``source signature`` may be altered by postdepositional weathering or biodegradation. In the present study, variation in PAH composition was investigated in size-fractionated sediments and depth-fractionated sediments collected from a Canadian fjord contaminated with aluminum smelter derived PAHs. Multivariate analyses of PAH compositional data consistently showed that different sampling sites could be discriminated on the basis of their PAH composition, but smaller versus larger size fractions within a site could not. The composition of unsubstituted and alkyl-substituted PAHs in a sediment core primarily showed changes with depth that were attributable to enhancement of anthropogenic inputs in the upper core segments. No trends with sediment depth, associated with compound-specific weathering or biotransformation, were noted in the composition of anthropogenically generated PAHs. This may indicate a limited chemical and biological availability of the aluminum smelter derived PAHs.

Simpson, C.D.; Harrington, C.F.; Cullen, W.R. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Chemistry Dept.; Bright, D.A.; Reimer, K.J. [Royal Roads Military College, Victoria, British Columbia (Canada). Environmental Sciences Group

1998-11-01

310

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

SciTech Connect

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

Merna, J.W.

1986-01-01

311

Stimulating the anaerobic degradation of aromatic hydrocarbons in contaminated sediments by providing an electrode as the electron acceptor.  

PubMed

The possibility that electrodes might serve as an electron acceptor to simulate the degradation of aromatic hydrocarbons in anaerobic contaminated sediments was investigated. Initial studies with Geobacter metallireducens demonstrated that although toluene was rapidly adsorbed onto the graphite electrodes it was rapidly oxidized to carbon dioxide with the electrode serving as the sole electron acceptor. Providing graphite electrodes as an electron acceptor in hydrocarbon-contaminated sediments significantly stimulated the removal of added toluene and benzene. Rates of toluene and benzene removal accelerated with continued additions of toluene and benzene. [(14)C]-Toluene and [(14)C]-benzene were quantitatively recovered as [(14)C]-CO(2), demonstrating that even though the graphite adsorbed toluene and benzene they were degraded. Introducing an electrode as an electron acceptor also accelerated the loss of added naphthalene and [(14)C]-naphthalene was converted to [(14)C]-CO(2). The results suggest that graphite electrodes can serve as an electron acceptor for the degradation of aromatic hydrocarbon contaminants in sediments, co-localizing the contaminants, the degradative organisms and the electron acceptor. Once in position, they provide a permanent, low-maintenance source of electron acceptor. Thus, graphite electrodes may offer an attractive alternative for enhancing contaminant degradation in anoxic environments. PMID:20105223

Zhang, Tian; Gannon, Sarah M; Nevin, Kelly P; Franks, Ashley E; Lovley, Derek R

2010-01-26

312

Cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and phenols in contaminated soil slurries  

SciTech Connect

This work aimed to evaluate the relative contribution of soil catabolic activity, contaminant bioaccessibility, and nutrient levels on the biodegradation of field-aged polycyclic aromatic hydrocarbons and phenolic compounds in three municipal gas plant site soils. Extents of biodegradation achieved, in 6 week-long soil slurry assays, under the following conditions were compared: (i) with inoculation of catabolically active PAH and phenol-degrading microorganisms, (ii) with and without hydroxypropyl-{beta}-cyclodextrin supplementation (HPCD; 100 g L{sup -1}), and finally (iii) with the provision of additional inorganic nutrients in combination with HPCD. Results indicated no significant (p {lt} 0.05) differences between biodegradation endpoints attained in treatments inoculated with catabolically active microorganisms as compared with the uninoculated control. Amendments with HPCD significantly (p {lt} 0.05) lowered biodegradation endpoints for most PAHs and phenolic compounds. Only in one soil did the combination of HPCD and nutrients consistently achieve better bioremediation endpoints with respect to the HPCD-only treatments. Thus, for most compounds, biodegradation was not limited by the catabolic activity of the indigenous microorganisms but rather by processes resulting in limited availability of contaminants to degraders. It is therefore suggested that the bioremediation of PAH and phenol impacted soils could be enhanced through HPCD amendments. In addition, the biodegradability of in situ and spiked (deuterated analogues) PAHs following 120 days aging of the soils suggested that this contact time was not sufficient to obtain similar partitions to that observed for field-aged contaminants; with the spiked compounds being significantly (p {lt} 0.05) more available for biodegradation. 42 refs., 5 figs., 2 tabs.

Ian J. Allan; Kirk T. Semple; Rina Hare; Brian J. Reid [University of East Anglia (United Kingdom). School of Environmental Sciences

2007-08-01

313

Genotypic and phenotypic responses of a riverine microbial community to polycyclic aromatic hydrocarbon contamination  

SciTech Connect

The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site was the Little Scioto River, a highly impacted, channelized riverine system located in central Ohio. This study site is a unique lotic system, with all sampling stations having similar flow and sediment characteristics both upstream and downstream from the source of contamination. These characteristics allowed for the specific analysis of PAH impact on the microbial community. PAH concentrations in impacted sediments ranged from 22 to 217 {micro}g g(dry weight) of sediment{sup {minus}1}, while PAH concentrations in ambient sediments ranged from below detection levels to 1.5 {micro}g g (dry weight) of sediment{sup {minus}1}. Total microbial biomass measured by phospholipid phosphate (PLP) analysis ranged from 95 to 345 nmol of PLP g(dry weight) of sediment{sup {minus}1}. Nucleic acid analysis showed the presence of PAH-degradative genes at all sites, although observed frequencies were typically higher at contaminated sites. Principal component analysis of PLFA profiles indicated that moderate to high PAH concentrations altered microbial community structure and that seasonal changes were comparable in magnitude to the effects of PAH pollution. These data indicate that this community responded to PAH contamination at both the phenotypic and the genotypic level.

Langworthy, D.E.; Findlay, R.H. [Miami Univ., Oxford, OH (United States). Dept. of Microbiology; Stapleton, R.D.; Sayler, G.S. [Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology

1998-09-01

314

Genotypic and Phenotypic Responses of a Riverine Microbial Community to Polycyclic Aromatic Hydrocarbon Contamination  

PubMed Central

The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated (22 to 217 ?g g [dry weight] of sediment?1) levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site was the Little Scioto River, a highly impacted, channelized riverine system located in central Ohio. This study site is a unique lotic system, with all sampling stations having similar flow and sediment characteristics both upstream and downstream from the source of contamination. These characteristics allowed for the specific analysis of PAH impact on the microbial community. PAH concentrations in impacted sediments ranged from 22 to 217 ?g g (dry weight) of sediment?1, while PAH concentrations in ambient sediments ranged from below detection levels to 1.5 ?g g (dry weight) of sediment?1. Total microbial biomass measured by phospholipid phosphate (PLP) analysis ranged from 95 to 345 nmol of PLP g (dry weight) of sediment?1. Nucleic acid analysis showed the presence of PAH-degradative genes at all sites, although observed frequencies were typically higher at contaminated sites. Principal component analysis of PLFA profiles indicated that moderate to high PAH concentrations altered microbial community structure and that seasonal changes were comparable in magnitude to the effects of PAH pollution. These data indicate that this community responded to PAH contamination at both the phenotypic and the genotypic level.

Langworthy, Donald E.; Stapleton, Raymond D.; Sayler, Gary S.; Findlay, Robert H.

1998-01-01

315

Bacterial communities of surface and deep hydrocarbon-contaminated waters of the Deepwater Horizon oil spill  

NASA Astrophysics Data System (ADS)

We performed a 16S rRNA gene sequencing survey of bacterial communities within oil-contaminated surface water, deep hydrocarbon plume water, and deep water samples above and below the plume to determine spatial and temporal patterns of oil-degrading bacteria growing in response to the Deepwater Horizon oil leak. In addition, we are reporting 16S rRNA sequencing results from time series incubation, enrichment and cultivation experiments. Surface oil slick samples were collected 3 nautical miles from ground zero, (5/6/10, RV Pelican) and were added to uncontaminated surface water (collected within a 30 nautical mile radius of ground zero, 5/6/10 - 5/9/10, RV Pelican). This mixture was incubated for 20 days in a rolling bottle at 25°C. 16S rRNA clone libraries from marine snow-like microbial flocs that had formed during the incubation yielded a highly diverse bacterial community, predominately composed of the Alpha- and Gammaproteobacteria, and a smaller number of Planktomycetes and other bacterial lineages. The most frequently recovered proteobacterial sequences were closely related to cultured species of the genus Cycloclasticus, specialists in aerobic oxidation of aromatic hydrocarbons. These time series incubation results will be compared to the microbial community structure of contaminated surface water, sampled on the same cruise with RV Pelican (5/6/10-5/9/10) and frozen immediately. Stable isotope probing (SIP) experiments with C13-labelled alkanes and polycyclic aromatic substrates and gulf water samples have yielded different enrichments. With naphthalene, predominantly Alteromonas-related clones and a smaller share of Cycloclasticus clones were recovered; phenanthrene yielded predominantly clones related to Cycloclasticus, and diverse other Gamma- and Alphaproteobacteria. Analyses of SIP experiments with hexadecane are in progress. The microbial community composition of the deep hydrocarbon plume was characterized using water column profile samples taken with RV Walton Smith on May 30, at station WS 46 near the leak (28°N659.35; 88°W.43498). Water was collected and filtered from above the plume (800 m), within the plume (1170 m and 1210 m) and below the plume (1320 m) as indicated by Color Dissolved Organic Matter (CDOM) measurements. Clone libraries of both plume samples were dominated by a cluster of closely related 16S rRNA clones within the Oceanospirillales. The closest relatives were aerobic alkane oxidizers of the genera Oleispira and Thalassolituus. In contrast, the water samples above and below the plume showed distinct, diverse bacterial communities that lacked the characteristic clones of the hydrocarbon plume. Analysis of additional water samples from different locations and time points will further resolve spatial and temporal dynamics of oil degrading microbes in the water column. Thus far, our results indicate a stratified bacterial community in the oil-polluted water column with distinct types of oil-degrading bacteria in surface oil slicks and finely dispersed deepwater plumes.

Yang, T.; Nigro, L. M.; McKay, L.; Ziervogel, K.; Gutierrez, T.; Teske, A.

2010-12-01

316

Microbial Diversity in a Hydrocarbon- and Chlorinated-Solvent-Contaminated Aquifer Undergoing Intrinsic Bioremediation  

PubMed Central

A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons (mainly jet fuel) and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes were amplified directly from aquifer material DNA by PCR with universally conserved or Bacteria- or Archaea-specific primers and were cloned. A total of 812 clones were screened by restriction fragment length polymorphisms (RFLP), approximately 50% of which were unique. All RFLP types that occurred more than once in the libraries, as well as many of the unique types, were sequenced. A total of 104 (94 bacterial and 10 archaeal) sequence types were determined. Of the 94 bacterial sequence types, 10 have no phylogenetic association with known taxonomic divisions and are phylogenetically grouped in six novel division level groups (candidate divisions WS1 to WS6); 21 belong to four recently described candidate divisions with no cultivated representatives (OP5, OP8, OP10, and OP11); and 63 are phylogenetically associated with 10 well-recognized divisions. The physiology of two particularly abundant sequence types obtained from the methanogenic zone could be inferred from their phylogenetic association with groups of microorganisms with a consistent phenotype. One of these sequence types is associated with the genus Syntrophus; Syntrophus spp. produce energy from the anaerobic oxidation of organic acids, with the production of acetate and hydrogen. The organism represented by the other sequence type is closely related to Methanosaeta spp., which are known to be capable of energy generation only through aceticlastic methanogenesis. We hypothesize, therefore, that the terminal step of hydrocarbon degradation in the methanogenic zone of the aquifer is aceticlastic methanogenesis and that the microorganisms represented by these two sequence types occur in syntrophic association.

Dojka, Michael A.; Hugenholtz, Philip; Haack, Sheridan K.; Pace, Norman R.

1998-01-01

317

Bacterial Community Dynamics and Polycyclic Aromatic Hydrocarbon Degradation during Bioremediation of Heavily Creosote-Contaminated Soil  

PubMed Central

Bacterial community dynamics and biodegradation processes were examined in a highly creosote-contaminated soil undergoing a range of laboratory-based bioremediation treatments. The dynamics of the eubacterial community, the number of heterotrophs and polycyclic aromatic hydrocarbon (PAH) degraders, and the total petroleum hydrocarbon (TPH) and PAH concentrations were monitored during the bioremediation process. TPH and PAHs were significantly degraded in all treatments (72 to 79% and 83 to 87%, respectively), and the biodegradation values were higher when nutrients were not added, especially for benzo(a)anthracene and chrysene. The moisture content and aeration were determined to be the key factors associated with PAH bioremediation. Neither biosurfactant addition, bioaugmentation, nor ferric octate addition led to differences in PAH or TPH biodegradation compared to biodegradation with nutrient treatment. All treatments resulted in a high first-order degradation rate during the first 45 days, which was markedly reduced after 90 days. A sharp increase in the size of the heterotrophic and PAH-degrading microbial populations was observed, which coincided with the highest rates of TPH and PAH biodegradation. At the end of the incubation period, PAH degraders were more prevalent in samples to which nutrients had not been added. Denaturing gradient gel electrophoresis analysis and principal-component analysis confirmed that there was a remarkable shift in the composition of the bacterial community due to both the biodegradation process and the addition of nutrients. At early stages of biodegradation, the ?-Proteobacteria group (genera Sphingomonas and Azospirillum) was the dominant group in all treatments. At later stages, the ?-Proteobacteria group (genus Xanthomonas), the ?-Proteobacteria group (genus Sphingomonas), and the Cytophaga-Flexibacter-Bacteroides group (Bacteroidetes) were the dominant groups in the nonnutrient treatment, while the ?-Proteobacteria group (genus Xathomonas), the ?-Proteobacteria group (genera Alcaligenes and Achromobacter), and the ?-Proteobacteria group (genus Sphingomonas) were the dominant groups in the nutrient treatment. This study shows that specific bacterial phylotypes are associated both with different phases of PAH degradation and with nutrient addition in a preadapted PAH-contaminated soil. Our findings also suggest that there are complex interactions between bacterial species and medium conditions that influence the biodegradation capacity of the microbial communities involved in bioremediation processes.

Vinas, Marc; Sabate, Jordi; Espuny, Maria Jose; Solanas, Anna M.

2005-01-01

318

Intrinsic bioremediation of MTBE-contaminated groundwater at a petroleum-hydrocarbon spill site  

NASA Astrophysics Data System (ADS)

An oil-refining plant site located in southern Taiwan has been identified as a petroleum-hydrocarbon [mainly methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylenes (BTEX)] spill site. In this study, groundwater samples collected from the site were analyzed to assess the occurrence of intrinsic MTBE biodegradation. Microcosm experiments were conducted to evaluate the feasibility of biodegrading MTBE by indigenous microorganisms under aerobic, cometabolic, iron reducing, and methanogenic conditions. Results from the field investigation and microbial enumeration indicate that the intrinsic biodegradation of MTBE and BTEX is occurring and causing the decrease in MTBE and BTEX concentrations. Microcosm results show that the indigenous microorganisms were able to biodegrade MTBE under aerobic conditions using MTBE as the sole primary substrate. The detected biodegradation byproduct, tri-butyl alcohol (TBA), can also be biodegraded by the indigenous microorganisms. In addition, microcosms with site groundwater as the medium solution show higher MTBE biodegradation rate. This indicates that the site groundwater might contain some trace minerals or organics, which could enhance the MTBE biodegradation. Results show that the addition of BTEX at low levels could also enhance the MTBE removal. No MTBE removal was detected in iron reducing and methanogenic microcosms. This might be due to the effects of low dissolved oxygen (approximately 0.3 mg/L) within the plume. The low iron reducers and methanogens (<1.8×103 cell/g of soil) observed in the aquifer also indicate that the iron reduction and methanogenesis are not the dominant biodegradation patterns in the contaminant plume. Results from the microcosm study reveal that preliminary laboratory study is required to determine the appropriate substrates and oxidation-reduction conditions to enhance the biodegradation of MTBE. Results suggest that in situ or on-site aerobic bioremediation using indigenous microorganisms would be a feasible technology to clean up this MTBE-contaminated site.

Chen, K. F.; Kao, C. M.; Chen, T. Y.; Weng, C. H.; Tsai, C. T.

2006-06-01

319

Residual indoor contamination from world trade center rubble fires as indicated by polycyclic aromatic hydrocarbon profiles.  

PubMed

The catastrophic destruction of the World Trade Center (WTC) on Sept. 11, 2001 (9/11) created an immense dust cloud followed by fires that emitted smoke and soot into the air of New York City (NYC) well into December. Outdoor pollutant levels in lower Manhattan returned to urban background levels after about 200 days as the fires were put out and the debris cleanup was completed. However, particulate matter (PM) from the original collapse and fires also penetrated into commercial and residential buildings. This has created public concern because WTC dust is thought to cause adverse pulmonary symptoms including "WTC cough" and reduced lung capacity. Additionally, some recent studies have suggested a possible link between exposure to WTC contamination and other adverse health effects. Distinguishing between normal urban pollutant infiltration and residual WTC dust remaining in interior spaces is difficult; efforts are underway to develop such discriminator methods. Some progress has been made in identifying WTC dust by the content of fibers believed to be associated with the initial building collapse. There are also contaminants created by the fires that burned for 100 days in the debris piles of the building rubble. Using WTC ambient air samples, we have developed indicators for fire related PM based on the relative amounts of specific particle bound polycyclic aromatic hydrocarbons (PAHs) and the mass fraction of PAHs per mass of PM. These two parameters are combined, and we show a graphical method for discriminating between fire sources and urban particulate sources as applied to samples of settled dusts. We found that our PAHs based discriminator method can distinguish fire source contributions to WTC related particulate matter and dusts. Other major building fires or large open burn events could have similar PAHs characteristics. We found that random samples collected approximately 3.5 years after the WTC event from occupied indoor spaces (primarily residential) in the New York area are not statistically distinguishable from contemporary city background. PMID:16572771

Pleil, Joachim D; Funk, William E; Rappaport, Stephen M

2006-02-15

320

Development of Radon as a Natural Tracer for Monitoring the Remediation of NAPL Contamination in the Subsurface. Annual Report 2002.  

National Technical Information Service (NTIS)

Dense non-aqueous phase liquids (DNAPLs) such as trichloroethene (TCE) and perchloroethene (PCE) present long-term challenges in terms of quantification in the subsurface at many DOE facilities. Over the past year we have continued investigating a potenti...

B. M. Davis L. Semprini J. Istok

2002-01-01

321

Coupling in Silico Microbial Models with Reactive Transport Models to predict the Fate of Contaminants in the Subsurface.  

National Technical Information Service (NTIS)

This project successfully accomplished its goal of coupling genome-scale metabolic models with hydrological and geochemical models to predict the activity of subsurface microorganisms during uranium bioremediation. Furthermore, it was demonstrated how thi...

D. R. Lovley

2011-01-01

322

Use of slow-release fertilizer and biopolymers for stimulating hydrocarbon biodegradation in oil-contaminated beach sediments.  

PubMed

Nutrient concentration and hydrocarbon bioavailability are key factors affecting biodegradation rates of oil in contaminated beach sediments. The effect of a slow-release fertilizer, Osmocote, as well as two biopolymers, chitin and chitosan, on the bioremediation of oil-spiked beach sediments was investigated using an open irrigation system over a 56-day period under laboratory conditions. Osmocote was effective in sustaining a high level of nutrients in leached sediments, as well as elevated levels of microbial activity and rates of hydrocarbon biodegradation. Chitin was more biodegradable than chitosan and gradually released nitrogen into the sediment. The addition of chitin or chitosan to the Osmocote amended sediments enhanced biodegradation rates of the alkanes relative to the presence of Osmocote alone, where chitosan was more effective than chitin due to its greater oil sorption capacity. Furthermore, chitosan significantly enhanced the biodegradation rates of all target polycyclic aromatic hydrocarbons. PMID:16291209

Xu, Ran; Yong, Li Ching; Lim, Yong Giak; Obbard, Jeffrey Philip

2005-04-01

323

Analysis of the Impact of Subsurface Contaminant Plumes on Stream Water Quality Under Natural and Managed Conditions  

NASA Astrophysics Data System (ADS)

The Integrated Hydrology Model (InHM) is a fully-integrated 3D control-volume finite element model which can simulate water flow and solute transport on the two-dimensional land surface and in the three-dimensional dual-continua subsurface under variably-saturated conditions. Full coupling of the surface and subsurface flow regimes is accomplished by simultaneously solving one system of nonlinear discrete equations for overland flow rates and water depths, stream flow rates, subsurface pressure heads, saturations and velocities, as well as water fluxes between continua. The numerical solution of the coupled advection-dispersion equations describing solute transport in the surface and subsurface flow domains is achieved in an analogous manner. High-resolution 3D numerical experiments performed with the model evaluate the downstream surface-water and stream-bottom sediment quality arising from a subsurface solute plume discharging into a stream under natural conditions. These simulations are compared with cases where the plume is intercepted by pumping wells near point of discharge. Comparisons are made for low (baseflow) and high (precipitation-event driven) stream flow rates for each case. A sensitivity analysis involving different surface-subsurface and transport parameters and plume capture scenarios will also be presented.

Keizer, J. P.; Sudicky, E. A.

2001-12-01

324

Assessment of diesel contamination in groundwater using electromagnetic induction geophysical techniques  

SciTech Connect

Determining hydrocarbon plumes in groundwater is typically accomplished through the installation of extensive monitoring wells. Issues of scale and site heterogeneities tend to introduce errors in delineating the extent of contamination and environmental impact. In this study, electromagnetic induction survey was investigated as an alternative technique for mapping petroleum contaminants in the subsurface. The surveys were conducted at a coal mining site near Gillette, Wyoming, using the EM34-XL ground conductivity meter. Data from this survey were validated with known concentrations of diesel compounds detected in groundwater from the study site. Groundwater data correlated well with the electromagnetic survey data, which was used to generate a site model to identify subsurface diesel plumes. To our knowledge, this is one of the first studies to use electromagnetic survey techniques for mapping hydrocarbon contamination in groundwater. Results from this study indicate that this geophysical technique can be an effective tool for assessing subsurface petroleum hydrocarbon sources and plumes at contaminated sites.

Jin, S.; Fallgren, P.; Cooper, J.; Morris, J; . Urynowicz, M. [Western Research Institute, Laramie, WY (United States)

2008-07-01

325

Influence of ultraviolet light on the toxicity of sediments contaminated with polycyclic aromatic hydrocarbons  

SciTech Connect

Standard 10-d toxicity tests were conducted with freshwater benthic invertebrates using sediments containing a range of concentrations of polycyclic aromatic hydrocarbons (PAHs). The assays were performed both under normal laboratory fluorescent light and ultraviolet (UV) light, which mimicked wavelengths present in sunlight, at about 10% of ambient solar intensity. In sediments with elevated PAH concentrations, tests conducted with UV light resulted in significantly greater mortality of Hyalella azteca (amphipods) and Lumbriculus variegatus (oligochaetes) than tests performed under otherwise comparable conditions with fluorescent light. There also was increased mortality of these two species, relative to controls, when surviving organisms from the 10-d exposures to the PAH-contaminated sediments were placed in clean water under UV light for 2 h. These results suggest that the organisms accumulated PAHs from the test sediments, which were subsequently photoactivated by UV light to excited states more toxic than the ground-state molecules. The phenomenon of photoactivation has been examined for pelagic species exposed to PAHs, but not for benthic organisms exposed to sediment-associated PAHs. The results suggest that failure to consider photoactivation of PAHs by sunlight could result in sediment toxicity test methods or criteria that are underprotective of benthic organisms.

Ankley, G.T.; Collyard, S.A. (Environmental Protection Agency, Duluth, MN (United States)); Monson, P.D. (Univ. of Wisconsin, Superior, WI (United States)); Kosian, P.A. (Integrated Lab. Systems, Research Triangle Park, NC (United States))

1994-11-01

326

Using discriminant analysis to assess polycyclic aromatic hydrocarbons contamination in Yongding New River.  

PubMed

Yongding New River has been polluted by polycyclic aromatic hydrocarbons (PAHs) which are carcinogenic and mutagenic. In three periods (the abundant water period, mean water period, dry water period), ten sites (totally 30 samples) in Yongding New River were clustered into four categories by hierarchical cluster analysis (hierarchical CA). In the same cluster, the samples had the same approximate contamination situation. In order to eliminate the dimensional differences, the data in each sample, containing 16 kinds of PAHs, were standardized with normal standardization and maximum difference standardization. According to the results of the cubic clustering criterion, pseudo F, and pseudo t (2) (PST2), the proper number of clustering for the 30 samples is 4. Before conducting hierarchical CA and K-means cluster analysis on the samples, we used principal component analysis to obtain another group data set. This data set was composed of the principal component scores which are uncorrelated variables. Hierarchical CA and K-means cluster analysis were used to classify the two data sets into four categories. With the classification results of hierarchical CA and K-means cluster analysis, discriminant analysis is applied to determine which method was better for normalization of the original data and which one was proper to cluster the samples and establish discriminant functions so that a new sample can be grouped into the right categories. PMID:23657734

Wang, Xiaojing; Zou, Zhihong; Zou, Hui

2013-05-09

327

Pyrosequence analysis of bacterial communities in aerobic bioreactors treating polycyclic aromatic hydrocarbon-contaminated soil  

PubMed Central

Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified PAHs, including high-molecular-weight compounds, were removed to a greater extent in the weekly-fed bioreactor, which achieved total PAH removal of 76%. Molecular analyses, including pyrosequencing of 16S rRNA genes, revealed significant shifts in the soil bacterial communities after introduction to the bioreactors and differences in the abundance and types of bacteria in each of the bioreactors. The weekly-fed bioreactor displayed a more stable bacterial community with gradual changes over time, whereas the monthly-fed bioreactor community was less consistent and may have been more strongly influenced by the influx of untreated soil during feeding. Phylogenetic groups containing known PAH-degrading bacteria previously identified through stable-isotope probing of the untreated soil were differentially affected by bioreactor conditions. Sequences from members of the Acidovorax and Sphingomonas genera, as well as the uncultivated ‘‘Pyrene Group 2’’ were abundant in the bioreactors. However, the relative abundances of sequences from the Pseudomonas, Sphingobium, and Pseudoxanthomonas genera, as well as from a group of unclassified anthracene degraders, were much lower in the bioreactors compared to the untreated soil.

Richardson, Stephen D.; Aitken, Michael D.

2011-01-01

328

Determination of polycyclic aromatic hydrocarbons in contaminated water and soil samples by immunological and chromatographic methods  

SciTech Connect

An immunoassay was developed that can be used for the detection of polycyclic aromatic hydrocarbons (PAHs) in water, landfill leachate, and soil. As test format an indirect competitive microtiter plate ELISA (enzyme-linked immunosorbent assay) was applied. While groundwater samples from a former manufactured gas plant site could be analyzed directly, soil and landfill leachate had to be extracted and required at least a 100-fold dilution prior to immunochemical measurement. PAHs could be recovered from fortified reference soils as well as aged field samples with high yield using 1-h ultrasonication with acetonitrile. Extraction efficiency was comparable to Soxhlet extraction and ultrasonication with tetrahydrogurane. Recovery was lower with agitation but would still be acceptable for use in an on-site field test to provide rapid, semiquantitative, and reliable test results for making environmental decisions such as identifying hot spots, site mapping, monitoring of remediation processes, and selecting site samples for laboratory analysis. Classification of ELISA data showed that it was possible to estimate the PAH contamination in soils with about 5% false positive and 5% false negative results that may have arisen from heterogeneity of samples, cross-reactivity of compounds with a similar structure, humic acids, or unknown interferences.

Knopp, D.; Seifert, M.; Vaeaenaenen, V.; Niessner, R.

2000-05-15

329

Influence of the bioaccessible fraction of polycyclic aromatic hydrocarbons on the ecotoxicity of historically contaminated soils.  

PubMed

Sequential supercritical fluid extraction together with a two-site desorption model were employed to estimate the bioaccessible fraction of polycyclic aromatic hydrocarbons (PAHs) in four historically contaminated soils. The ecotoxicity of the soils was assayed by four different contact tests. The same soils were exposed to exhaustive extraction and the extracts were returned to the soils to ensure total 100% bioaccessibility of the pollutants. Then the soils were assayed again. Statistical evaluation revealed that the predicted bioaccessible PAHs generally correlated with the ecotoxicity responses of the tests. The estimated bioaccessible fractions varied from 10 to 98%. This value increased for PAHs with higher lipophilicity and showed no correlation with the organic carbon content in the soils. The ecotoxicity tests in the study indicated different sensitivity toward PAHs and the tests employing Heterocypris incongruens and Eisenia fetida were found to be more suitable than Lemna minor and Vibrio fischeri. Mortality and growth inhibition of ostracods correlated with all the types of PAHs and earthworm growth inhibition and mortality were preferentially sensitive to PAHs with only 3-4 aromatic rings. Determination of the biota-soil accumulation factors indicated that the earthworm growth inhibition corresponded to increased accumulation of PAHs in the earthworm tissue. PMID:23611796

?van?arová, Monika; K?esinová, Zdena; Cajthaml, Tomáš

2013-04-02

330

Cancer risk assessments of Hong Kong soils contaminated by polycyclic aromatic hydrocarbons.  

PubMed

The aim of this study was to evaluate soils from 12 different land use types on human cancer risks, with the main focus being on human cancer risks related to polycyclic aromatic hydrocarbons (PAHs). Fifty-five locations were selected to represent 12 different types of land use (electronic waste dismantling workshop (EW (DW)); open burning site (OBS); car dismantling workshop (CDW) etc.). The total concentrations of 16 PAHs in terms of total burden and their bioaccessibility were analysed using GC/MS. The PAHs concentrations were subsequently used to establish cancer risks in humans via three exposure pathways, namely, accident ingestion of soil, dermal contact soil and inhalation of soil particles. When the 95th centile values of total PAH concentrations were used to derive ingestion and dermal cancer risk probabilities on humans, the CDW land use type indicated a moderate potential for cancerous development (244×10(-6) and 209×10(-6), respectively). Bioaccessible PAHs content in soil samples from CDW (3.60×10(-6)) were also classified as low cancer risk. CDW soil possessed a higher carcinogenic risk based on PAH concentrations. Bioremediation is recommended to treat the contaminated soil. PMID:23465409

Man, Yu Bon; Kang, Yuan; Wang, Hong Sheng; Lau, Winifred; Li, Hui; Sun, Xiao Lin; Giesy, John P; Chow, Ka Lai; Wong, Ming Hung

2013-02-01

331

Trimethylbenzoic acids as metabolite signatures in the biogeochemical evolution of an aquifer contaminated with jet fuel hydrocarbons.  

PubMed

Evolution of trimethylbenzoic acids in the KC-135 aquifer at the former Wurtsmith Air Force Base (WAFB), Oscoda, MI was examined to determine the functionality of trimethylbenzoic acids as key metabolite signatures in the biogeochemical evolution of an aquifer contaminated with JP-4 fuel hydrocarbons. Changes in the composition of trimethylbenzoic acids and the distribution and concentration profiles exhibited by 2,4,6- and 2,3,5-trimethylbenzoic acids temporally and between multilevel wells reflect processes indicative of an actively evolving contaminant plume. The concentration levels of trimethylbenzoic acids were 3-10 orders higher than their tetramethylbenzene precursors, a condition attributed to slow metabolite turnover under sulfidogenic conditions. The observed degradation of tetramethylbenzenes into trimethylbenzoic acids obviates the use of these alkylbenzenes as non-labile tracers for other degradable aromatic hydrocarbons, but provides rare field evidence on the range of high molecular weight alkylbenzenes and isomeric assemblages amenable to anaerobic degradation in situ. The coupling of actual tetramethylbenzene loss with trimethylbenzoic acid production and the general decline in the concentrations of these compounds demonstrate the role of microbially mediated processes in the natural attenuation of hydrocarbons and may be a key indicator in the overall rate of hydrocarbon degradation and the biogeochemical evolution of the KC-135 aquifer. PMID:14607476

Namocatcat, J A; Fang, J; Barcelona, M J; Quibuyen, A T O; Abrajano, T A

2003-12-01

332

Biodegradation of an alicyclic hydrocarbon by a sulfate-reducing enrichment from a gas condensate-contaminated aquifer.  

PubMed

We used ethylcyclopentane (ECP) as a model alicyclic hydrocarbon and investigated its metabolism by a sulfate-reducing bacterial enrichment obtained from a gas condensate-contaminated aquifer. The enrichment coupled the consumption of ECP with the stoichiometrically expected amount of sulfate reduced. During ECP biodegradation, we observed the transient accumulation of metabolite peaks by gas chromatography-mass spectrometry, three of which had identical mass spectrometry profiles. Mass-spectral similarities to analogous authentic standards allowed us to identify these metabolites as ethylcyclopentylsuccinic acids, ethylcyclopentylpropionic acid, ethylcyclopentylcarboxylic acid, and ethylsuccinic acid. Based on these findings, we propose a pathway for the degradation of this alicyclic hydrocarbon. Furthermore, a putative metabolite similar to ethylcyclopentylsuccinic acid was also found in samples of contaminated groundwater from the aquifer. However, no such finding was evident for samples collected from wells located upgradient of the gas condensate spill. Microbial community analysis of the ECP-degrading enrichment by denaturing gradient gel electrophoresis revealed the presence of at least three different organisms using universal eubacterial primers targeting 550 bp of the 16S rRNA gene. Based on sequence analysis, these organisms are phylogenetically related to the genera Syntrophobacter and Desulfotomaculum as well as a member of the Cytophaga-Flexibacter-Bacteroides group. The evidence suggests that alicyclic hydrocarbons such as ECP can be anaerobically activated by the addition to the double bond of fumarate to form alkylsuccinate derivatives under sulfate-reducing conditions and that the reaction occurs in the laboratory and in hydrocarbon-impacted environments. PMID:12514025

Rios-Hernandez, Luis A; Gieg, Lisa M; Suflita, Joseph M

2003-01-01

333

Polycyclic aromatic hydrocarbons and trace metal contamination of coastal sediment and biota from Togo.  

PubMed

The state of contamination of tropical environments, particularly in Africa, remains a relatively under explored subject. Here, we determined polycyclic aromatic hydrocarbon (PAH) and trace metal concentrations in coastal sediment and biota samples (fish and mussels) from Togo (West Africa). In the sediments, the ?21 PAH concentrations ranged from <4 ng g(-1) to 257 ng g(-1), averaging 92 ng g(-1). Concentration ratios of low molecular weight PAHs (2-3 rings) versus high molecular weight PAHs (?4 rings) were always lower than 1 (ranging from 0.08 to 0.46) indicating that high molecular weight PAHs were dominant in all sediment samples, and that PAHs originated mainly from anthropogenic combustion activities. The sediments were also analyzed for major elements and a total of 15 trace metals, which were found in elevated concentrations. The calculated enrichment factor (EF) values relative to the Earth's crust show that the contamination is extremely severe for Cd (EF = 191), severe for Cr (EF = 18) and U (EF = 17.8), moderately severe for Zr (EF = 8.8), for Ni (EF = 6.8), Sr (EF = 5.9) and Ba (EF = 5.4), and moderate for V (EF = 3.6) and Zn (EF = 3.4). Sediments sampled in areas affected by the dumping of phosphorite mine tailings showed particularly high concentrations of trace metals. Overall, concentrations of both PAHs and trace metals in sediment tend to increase from the coastline to the open sea (2 km offshore). This is attributable to the increasingly finer texture of coastal sediment found offshore, which has a terrigenous origin and appears loaded with various contaminants through adsorption processes. Such high loads of trace metals were also found in the biota (fish and mussels). The ratio of measured trace metal concentrations in biota to threshold limits set by the World Health Organization herein defined as relative health factor (RHF) was high. Average RHF values in fish were highest for Se (470), As (250), Ag (97), Ni (78), Mn (63), Fe (53), Pb (36), Cd (10), and Cr (7) while lowest for Cu (0.08) and Zn (0.03). Cd and Al did not bioaccumulate in the analyzed fish species. In mussels, the RHF values were highest for Fe (9,108), As (295), Pb (276), Se (273), Mn (186), Ni (71), Ag (70), Cd (14), and Cu (4). PMID:21655572

Gnandi, Kissao; Musa Bandowe, Benjamin A; Deheyn, Dimitri D; Porrachia, Magali; Kersten, Michael; Wilcke, Wolfgang

2011-06-08

334

Activity and Diversity of Sulfate-Reducing Bacteria in a Petroleum Hydrocarbon-Contaminated Aquifer  

PubMed Central

Microbial sulfate reduction is an important metabolic activity in petroleum hydrocarbon (PHC)-contaminated aquifers. We quantified carbon source-enhanced microbial SO42? reduction in a PHC-contaminated aquifer by using single-well push-pull tests and related the consumption of sulfate and added carbon sources to the presence of certain genera of sulfate-reducing bacteria (SRB). We also used molecular methods to assess suspended SRB diversity. In four consecutive tests, we injected anoxic test solutions (1,000 liters) containing bromide as a conservative tracer, sulfate, and either propionate, butyrate, lactate, or acetate as reactants into an existing monitoring well. After an initial incubation period, 1,000 liters of test solution-groundwater mixture was extracted from the same well. Average total test duration was 71 h. We measured concentrations of bromide, sulfate, and carbon sources in native groundwater as well as in injection and extraction phase samples and characterized the SRB population by using fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE). Enhanced sulfate reduction concomitant with carbon source degradation was observed in all tests. Computed first-order rate coefficients ranged from 0.19 to 0.32 day?1 for sulfate reduction and from 0.13 to 0.60 day?1 for carbon source degradation. Sulfur isotope fractionation in unconsumed sulfate indicated that sulfate reduction was microbially mediated. Enhancement of sulfate reduction due to carbon source additions in all tests and variability of rate coefficients suggested the presence of specific SRB genera and a high diversity of SRB. We confirmed this by using FISH and DGGE. A large fraction of suspended bacteria hybridized with SRB-targeting probes SRB385 plus SRB385-Db (11 to 24% of total cells). FISH results showed that the activity of these bacteria was enhanced by addition of sulfate and carbon sources during push-pull tests. However, DGGE profiles indicated that the bacterial community structure of the dominant species did not change during the tests. Thus, the combination of push-pull tests with molecular methods provided valuable insights into microbial processes, activities, and diversity in the sulfate-reducing zone of a PHC-contaminated aquifer.

Kleikemper, Jutta; Schroth, Martin H.; Sigler, William V.; Schmucki, Martina; Bernasconi, Stefano M.; Zeyer, Josef

2002-01-01

335

Use of slow-release fertilizer and biopolymers for stimulating hydrocarbon biodegradation in oil-contaminated beach sediments  

Microsoft Academic Search

Nutrient concentration and hydrocarbon bioavailability are key factors affecting biodegradation rates of oil in contaminated beach sediments. The effect of a slow-release fertilizer, Osmocote, as well as two biopolymers, chitin and chitosan, on the bioremediation of oil-spiked beach sediments was investigated using an open irrigation system over a 56-day period under laboratory conditions. Osmocote was effective in sustaining a high

Ran Xu; Li Ching Yong; Yong Giak Lim; Jeffrey Philip Obbard

2005-01-01

336

Chlorinated hydrocarbon contaminants and metabolites in polar bears ( Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996?2002  

Microsoft Academic Search

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO2) PCB and p,p?-dichlorodiphenyldichloroethylene (p,p?-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The

Jonathan Verreault; Derek C. G. Muir; Ross J. Norstrom; Ian Stirling; Aaron T. Fisk; Geir W. Gabrielsen; Andrew E. Derocher; Thomas J. Evans; Rune Dietz; Christian Sonne; Gregory M. Sandala; Wouter Gebbink; Frank F. Riget; Erik W. Born; Mitch K. Taylor; John Nagy; Robert J. Letcher

2005-01-01

337

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 19962002  

Microsoft Academic Search

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO2) PCB and p,pV-dichlorodiphenyldichloroethylene (p,pV-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The

Jonathan Verreault; Derek C. G. Muir; Ross J. Norstrom; Ian Stirling; Aaron T. Fisk; Geir W. Gabrielsen; Andrew E. Derocher; Thomas J. Evans; Rune Dietz; Gregory M. Sandala; Wouter Gebbink; Frank F. Riget; Erik W. Born; Mitch K. Taylor; John Nagy; Robert J. Letcher

2005-01-01

338

Trimethylbenzoic acids as metabolite signatures in the biogeochemical evolution of an aquifer contaminated with jet fuel hydrocarbons  

Microsoft Academic Search

Evolution of trimethylbenzoic acids in the KC-135 aquifer at the former Wurtsmith Air Force Base (WAFB), Oscoda, MI was examined to determine the functionality of trimethylbenzoic acids as key metabolite signatures in the biogeochemical evolution of an aquifer contaminated with JP-4 fuel hydrocarbons. Changes in the composition of trimethylbenzoic acids and the distribution and concentration profiles exhibited by 2,4,6- and

J. A. Namocatcat; J. Fang; M. J. Barcelona; A. T. O. Quibuyen; T. A. Abrajano

2003-01-01

339

Metabolic and phylogenetic analysis of microbial communities during phytoremediation of soil contaminated with weathered hydrocarbons and heavy metals  

Microsoft Academic Search

In the current study, the microbial ecology of weathered hydrocarbon and heavy metal contaminated soil undergoing phytoremediation\\u000a was studied. The relationship of functional diversity, measured as carbon source utilisation in Biolog plates and extracellular\\u000a enzymatic activities, and genetic diversity of bacteria was evaluated. Denaturing gradient gel electrophoresis was used for\\u000a community analyses at the species level. Bulk soil and rhizosphere

Marja R. T. Palmroth; Perttu E. P. Koskinen; Anna H. Kaksonen; Uwe Münster; John Pichtel; Jaakko A. Puhakka

2007-01-01

340

Emerging organic contaminant removal depending on primary treatment and operational strategy in horizontal subsurface flow constructed wetlands: influence of redox.  

PubMed

This study aimed at assessing the influence of primary treatment (hydrolytic upflow sludge blanket (HUSB) reactor vs. conventional settling) and operational strategy (alternation of saturated/unsaturated phases vs. permanently saturated) on the removal of various emerging organic contaminants (i.e. ibuprofen, diclofenac, acetaminophen, tonalide, oxybenzone, bisphenol A) in horizontal subsurface flow constructed wetlands. For that purpose, a continuous injection experiment was carried out in an experimental treatment plant for 26 days. The plant had 3 treatment lines: a control line (settler-wetland permanently saturated), a batch line (settler-wetland operated with saturate/unsaturated phases) and an anaerobic line (HUSB reactor-wetland permanently saturated). In each line, wetlands had a surface area of 2.95 m(2), a water depth of 25 cm and a granular medium D(60) = 7.3 mm, and were planted with common reed. During the study period the wetlands were operated at a hydraulic and organic load of 25 mm/d and about 4.7 g BOD/m(2)d, respectively. The injection experiment delivered very robust results that show how the occurrence of higher redox potentials within the wetland bed promotes the elimination of conventional quality parameters as well as emerging microcontaminants. Overall, removal efficiencies were always greater for the batch line than for the control and anaerobic lines, and to this respect statistically significantly differences were found for ibuprofen, diclofenac, oxybenzone and bisphenol A. As an example, ibuprofen, whose major removal mechanism has been reported to be biodegradation under aerobic conditions, showed a higher removal in the batch line (85%) than in the control (63%) and anaerobic (52%) lines. Bisphenol A showed also a great dependence on the redox status of the wetlands, finding an 89% removal rate for the batch line, as opposed to the control and anaerobic lines (79 and 65%, respectively). Furthermore, diclofenac showed a greater removal under a higher redox status (70, 48 and 32% in the batch, control and anaerobic lines). Average removal efficiencies of acetaminophen, oxybenzone and tonalide were almost >90% for the 3 treatment lines. The results of this study indicate that the efficiency of horizontal flow constructed wetland systems can be improved by using a batch operation strategy. Furthermore, we tentatively identified 4-hydroxy-diclofenac and carboxy-bisphenol A as intermediate degradation products. The higher abundance of the latter under the batch operation strategy reinforced biodegradation as a relevant bisphenol A removal pathway under higher redox conditions. PMID:23123085

Avila, Cristina; Reyes, Carolina; Bayona, Josep María; García, Joan

2012-10-23

341

Enumeration and characterization of the soil microflora from hydrocarbon-contaminated soil sites able to mineralize polycyclic aromatic hydrocarbons (PAH)  

Microsoft Academic Search

The use of a plate screening technique allowed the direct isolation and quantification of polycylic aromatic hydrocarbon (PAH)-degrading bacteria from different soil sites. Bacteria that were able to grow on anthracene, phenanthrene, fluoranthene or pyrene as a sole carbon source were found with numbers between 103 and 105 colony-forming units (cfu)\\/g of soil dry weight, but only in samples that

M. Kästner; M. Breuer-Jammali; B. Mahro

1994-01-01

342

Hydrocarbon Gases in Hydrogeologically Isolated Fractures in Au Mines of the Witwatersrand Basin, South Africa: Potential Substrates for Deep Subsurface Microorganisms  

NASA Astrophysics Data System (ADS)

Deep subsurface microbial communities are the subject of a multi-disciplinary study in the Witwatersrand Basin, of South Africa. Hydrocarbon and H2 gases found in the mines were investigated to determine their origin and role as potential substrates for long-term survival of microorganisms. Large quantities of gas (up to 30L/min/borehole) are released when sealed fracture systems are opened by exploration drilling. Two compositionally and isotopically distinct types of gases have been identified in the Witwatersrand and Ventersdorp sequences beneath the Transvaal Sequence. Group 1 gases correspond to major fault intersections within the Witwatersrand Supergroup and contain methane that is isotopically depleted in 13C (-43.5 to -59.4 permil), and enriched in 2H (-162 to -214 permil) consistent with either bacteriogenic and/or thermogenic orgins. Group 2 gases discharges in association with saline fissure waters from fractures within the andesitic lava of the Ventersdorp Sequence. They are isotopically depleted in 2H (to -327 permil), and enriched in 13C (to -34.4 permil) falling outside the conventional bacteriogenic or thermogenic isotopic fields. Group 2 gases do however resemble those reported from Precambrian Shield mines in Canada for which an abiogenic origin has been suggested. Differences in the microbial communities associated with these different gas types and geologic strata are under investigation.

Ward, J. A.; Slater, G. F.; Lacrampe-Couloume, G.; Hall, J.; Moser, D.; Lin, L.; Lippmann, J.; Davidson, M.; Onstott, T.; Sherwood Lollar, B.

2001-12-01

343

Ecohydrological Linkage Between Surface-Derived Dissolved Organic Matter and Subsurface Carrying Capacity for Unattached Subsurface Bacterial Populations: Implications for Biodegradation in Contaminated Groundwater Environments  

NASA Astrophysics Data System (ADS)

Degradation by aquifer microbial populations of dissolved organic matter (DOM) transported from the surface environment exerts strong controls on the concentration, composition, and reactivity of DOM as it is transported in ground water. In turn, the quantity of readily degradable DOM may be a major control of the carrying capacity for bacteria in groundwater and, consequently, would affect the fate of lower levels of organic contaminants being advected through the same sediments. For a 5-km long plume of groundwater organic contaminants in a sandy aquifer at Cape Cod, Massachusetts, the partitioning of bacteria between solution and grain surfaces increased with decreasing distance downgradient from the source. In general, the unattached bacterial populations were particularly sensitive to the level of DOM present. Approximately 2/3 of the spatial variability for unattached bacteria within the upgradient 3 km of the contaminant plume can be explained statistically simply by the abundance of the more degradable (non alkyl benzene surfactant [ABS]) DOM, even though predation by groundwater nanoflagellates (protists) and sorptive-filtration of unattached bacteria both vary spatially. However, distance downgradient from the contaminant source, which directly correlates with both the age and abundance of the DOM, could explain ~98% of the variability of unattached bacteria along the longitudinal axis of the plume. Down-well incubations (USGS well site F513) were performed using membrane (100K Dalton cutoff) chambers (initially seeded with undifferentiated, laboratory-grown aquifer bacteria at abundances of 1 x 105 or of 1 x 107 bacteria/mL) that come to chemical equilibrium with surrounding groundwater within ~1 day. Following a 7-day down-well incubation, numbers of unattached bacteria within the chambers converged on a final abundance value of 2.0 ± 0.6 x 106 bacteria per mL, consistent with the in-situ bacterial abundance within that part of the plume (typically between 1.0 x 106 and 2.0 x 106/mL). Incubation for a longer (21 day) period resulted in final bacterial abundances that were not statistically different than those observed for the shorter (7-day) incubations. Results from the Cape Cod study suggests the carrying capacity of the system for unattached groundwater bacteria that are advecting downgradient with specific organic contaminants may be determined by the more degradable fraction of the DOM.

Harvey, R. W.; Gruden, C. L.; Aiken, G. R.; Metge, D. W.; Kinner, N. E.

2004-12-01

344

Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models  

DOEpatents

A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management. 20 figs.

He, W.; Anderson, R.N.

1998-08-25

345

Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models  

DOEpatents

A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management.

He, Wei (New Milford, NJ); Anderson, Roger N. (New York, NY)

1998-01-01

346

A comprehensive inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the INEL RWMC during the years 1984-2003, Volume 2  

SciTech Connect

This is the second volume of this comprehensive report of the inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the Idaho National Engineering Laboratory. Appendix B contains a complete printout of contaminant inventory and other information from the CIDRA Database and is presented in volumes 2 and 3 of the report.

NONE

1995-05-01

347

A comprehensive inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the INEL RWMC during the years 1984-2003, Volume 3  

SciTech Connect

This is the third volume of this comprehensive report of the inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the Idaho National Engineering Laboratory. Appendix B contains a complete printout of contaminant inventory and other information from the CIDRA Database and is presented in volumes 2 and 3 of the report.

NONE

1995-05-01

348

Millimeter-scale concentration gradients of hydrocarbons in Archean shales: Live-oil escape or fingerprint of contamination?  

NASA Astrophysics Data System (ADS)

Archean shales from the Pilbara in Western Australia contain biomarkers that have been interpreted as evidence for the existence of cyanobacteria and eukaryotes 2.7 billion years (Ga) ago, with far reaching implications for the evolution of Earth's early biosphere. To re-evaluate the provenance of the biomarkers, this study determined the spatial distribution of hydrocarbons in the original drill core material. Rock samples were cut into millimeter-thick slices, and the molecular content of each slice was analyzed. In core from the Hamersley Group (˜2.5 Ga), C <13 alkanes had gradually increasing concentrations from the surfaces to the center of the rock while the abundance of steranes, hopanes and C 15+ alkanes decreased with distance from the outer surfaces. In samples from the Fortescue Group (˜2.7 Ga), hydrocarbons were overwhelmingly concentrated on rock surfaces. Two mechanisms are proposed that may have caused the inhomogeneous distribution: diffusion of petroleum products into the rock (contamination model), and leaching of indigenous hydrocarbons out of host shales driven by pressure release after drilling ('live-oil' effect). To test these models, the hydrocarbon distributions in the Archean shales are compared with artificially contaminated rocks as well as younger mudstones where leaching of live-oil had been observed. The results show that chromatographic phenomena associated with live-oil escape and contaminant diffusion have strong effects on molecular ratios and maturity parameters, potentially with broad implications for oil-source rock correlation studies and paleoenvironmental interpretations. For the Archean shales, the live-oil effect is consistent with some of the observed patterns, but only the contamination model fully explains the complex chromatographic fingerprints. Therefore, the biomarkers in the Pilbara samples have an anthropogenic origin, and previous conclusions about the origin of eukaryotes and oxygenic photosynthesis based on these samples are not valid. However, the study also identified indigenous molecules. The spatial distribution of particular aromatic hydrocarbons suggests they are syngenetic. Although devoid of biological information, these aromatics now represent the oldest known clearly-indigenous terrestrial liquid hydrocarbons.

Brocks, Jochen J.

2011-06-01

349

Assessing the correlation between anaerobic toluene degradation activity and bssA concentrations in hydrocarbon-contaminated aquifer material.  

PubMed

The assessment of biodegradation activity in contaminated aquifers is critical to demonstrate the performance of bioremediation and natural attenuation and to parameterize models of contaminant plume dynamics. Real time quantitative PCR (qPCR) was used to target the catabolic bssA gene (coding for benzylsuccinate synthase) and a 16S rDNA phylogenetic gene (for total Bacteria) as potential biomarkers to infer on anaerobic toluene degradation rates. A significant correlation (P = 0.0003) was found over a wide range of initial toluene concentrations (1-100 mg/l) between toluene degradation rates and bssA concentrations in anaerobic microcosms prepared with aquifer material from a hydrocarbon contaminated site. In contrast, the correlation between toluene degradation activity and total Bacteria concentrations was not significant (P = 0.1125). This suggests that qPCR targeting of functional genes might offer a simple approach to estimate in situ biodegradation activity, which would enhance site investigation and modeling of natural attenuation at hydrocarbon-contaminated sites. PMID:20204467

Kazy, Sufia K; Monier, Amy L; Alvarez, Pedro J J

2010-03-04

350

Cyclodextrin-enhanced in situ bioremediation of polyaromatic hydrocarbons-contaminated soils and plant uptake  

Microsoft Academic Search

In situ bioremediation of polycyclic aromatic hydrocarbons (PAH) polluted soils can be improved by the augmentation of degrading\\u000a microbial populations and by the increase of hydrocarbon bioavailability. ?-cyclodextrin (?-CD) significantly accelerate the\\u000a induction of hydrocarbon biodegradation, but it is not still clear its effectiveness during final, slower stages of degradation.\\u000a Moreover, it is yet not known if the PAH uptake

L. Bardi; C. Martini; F. Opsi; E. Bertolone; S. Belviso; G. Masoero; M. Marzona; F. Ajmone Marsan

2007-01-01

351

Supercritical carbon dioxide extraction of polycyclic aromatic hydrocarbons from contaminated soil  

SciTech Connect

Supercritical fluids (SCFs) can achieve high efficiencies in the extraction of organic contaminants from soil due the unique properties of a fluid in the vicinity of its critical point. However, the adsorptive interactions between a complex matrix such as soil, nonpolar organic species, and nonpolar SCFs are not well understood. The adsorptive behavior of several polycyclic aromatic hydrocarbons (PAHs) from supercritical carbon dioxide (SC CO[sub 2]) onto a sandy loam soil was characterized. Solubility and adsorption measurements were carried out in a novel apparatus which incorporated on-line sampling of high-pressure SC CO[sub 2] circulating through a fixed bed extractor. Data for solubility of phenanthrene, anthracene, triphenylene, chrysene and perylene in SC CO[sub 2] at temperatures ranging from 25 to 70C and fluid densities of 0.7 to 0.9 g/mL demonstrates a relationship between solubility and carbon number/angularity of the ring structure. PAH solubility follows a van't Hoff type functionality, with heats of solution, [Delta]H[sub sol], obtained from linear plots of ln [solubility] versus 1/T. Magnitudes of [Delta]H[sub sol], comprised of additive contributions of fusion and dilution, ranged from 9 to 11 kcal/mole, consistent with weak van der Waals solute/solvent interactions. Solubilities are enhanced by addition of a polar modifier. A solubility model, based on Scatchard-Hildebrand Regular Solution Theory, was developed to describe the P-T behavior of PAH solubility. Soil adsorption isotherms for these compounds are non-linear, and were described using Freundlich and Brunauer-Emmett-Teller adsorption models.

Andrews, A.T.

1990-01-01

352

Mutagenicity and genotoxicity of Hong Kong soils contaminated by polycyclic aromatic hydrocarbons and dioxins/furans.  

PubMed

The aim of this study was to evaluate mutagenicity and genotoxicity of soils from 12 different land use types such as electronic waste dismantling workshop, open burning site and car dismantling workshop (CDW), based on soil concentrations of polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs). Soils of CDW contained the sum of 10 PAHs level (94392?g/kg) exceeded The New Dutch List (Dutch Intervention Value (40000?g/kg)), dominated by high molecular PAHs (99.6%) and benzo(a)pyrene (82.6%), indicating its potential carcinogenic risks. In addition, Ames test and SOS Chromotest further manifested that soil of CDW had a significantly higher mutagenic potency (MP) of 13.8 and 7.43 on both strains of TA98 and TA100 with S9 mix, respectively, and a relatively higher genotoxicity with S9 mix (SOS inducing potency=1.16), amongst the 12 different soil types. BaP TEQ PAHs in soils were significantly correlated with MP of TA98, with and without S9 mix (r=0.858 and r=0.976 at p<0.01); MP of TA100 with and without S9 mix (r=0.666 at p<0.05 and r=0.819 at p<0.01); and SOSIP of Escherichia coli PQ 37 with S9 mix (r=0.693 at p<0.05), accordingly. Soils of CDW possessed a higher carcinogenic risk (mutagenicity and genotoxicity), based on PAHs concentrations. Bioremediation is recommended to treat the contaminated soils. PMID:23391780

Man, Yu Bon; Chow, Ka Lai; Kang, Yuan; Wong, Ming Hung

2013-02-04

353

Enhancement and inhibition of microbial activity in hydrocarbon- contaminated arctic soils: Implications for nutrient-amended bioremediation  

USGS Publications Warehouse

Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (<1%) end low moisture (1-3%) contents. We examined the effects of nutrient additions on microorganisms in contaminated soil from this site in laboratory microcosms and in mesocosms incubated for 6 weeks in the field. Nitrogen was the major limiting nutrient in this system, but microbial populations and activity were maximally enhanced by additions of both nitrogen and phosphorus. When nutrients were added to soil in the field at three levels of N:P (100:45, 200:90, and 300:135 mg/kg soil), the greatest stimulation in microbial activity occurred at the lowest, rather than the highest, level of nutrient addition. The total soil-water potentials ranged from -2 to -15 bar with increasing levels of fertilizer. Semivolatile hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (<1%) and low moisture (1-3%) contents. We examined the effects of nutrient additions on microorganisms in contaminated soil from this site in laboratory microcosms and in mesocosms incubated for 6 weeks in the field. Nitrogen was the major limiting nutrient in this system, but microbial populations and activity were maximally enhanced by additions of both nitrogen and phosphorus. When nutrients were added to soil in the field at three levels of N:P (100:45, 200:90, and 300:135 mg/kg soil), the greatest stimulation in microbial activity occurred at the lowest, rather than the highest, level of nutrient addition. The total soil-water potentials ranged from -2 to -15 bar with increasing levels of fertilizer. Semi-volatile hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.

Braddock, J. F.; Ruth, M. L.; Catterall, P. H.; Walworth, J. L.; Mccarthy, K. A.

1997-01-01

354

Profiles of Mycobacterium communities under polycyclic aromatic hydrocarbon contamination stress in the Shenfu Irrigation Area, northeast China.  

PubMed

Indigenous Mycobacterium communities play an important role in the degradation of polycyclic aromatic hydrocarbons (PAHs), but little is known about Mycobacterium distribution in situ at PAH-contaminated sites. In this study, the diversity and distribution of Mycobacterium communities were investigated in sediments and soils at sites upstream, midstream, and downstream of an oil-sewage irrigation channel, using denaturing gradient gel electrophoresis (DGGE). The results show that heavy PAH contamination in upstream sites negatively affected Mycobacterium community diversity compared with midstream and downstream sites in all 3 sample types (sediments, corn field soils, and rice field soils). There was a correlation between the distribution of Mycobacterium communities and PAH contamination, as indicated by canonical correspondence analysis. Mycobacterium diversity and distribution was found to vary between the 3 sample types. PMID:24102223

Li, Xinyu; Li, Xu; Wang, Jian; Wang, Xiujuan; Sun, Jian; Su, Zhencheng; Zhang, Huiwen; Li, Peijun

2013-10-03

355

ANNUAL REPORT. DEVELOPMENT OF RADON AS A NATURAL TRACER FOR MONITORING THE REMEDIATION OF NAPL CONTAMINATION IN THE SUBSURFACE  

EPA Science Inventory

Dense non-aqueous phase liquids (DNAPLs) such as trichloroethene (TCE) and perchloroethene (PCE) present long-term challenges in terms of quantification in the subsurface at many DOE facilities. Over the past year we have continued investigating a potentially lower-cost method fo...

356

BENZENE AND NAPHTHALENE SORPTION ON SOIL CONTAMINATED WITH HIGH MOLECULAR WEIGHT RESIDUAL HYDROCARBONS FROM UNLEADED GASOLINE  

EPA Science Inventory

For complex nonaqueous phase liquids (NAPLs), the composition of the NAPL retained in the pore space of geologic material weathers until the residual NAPL no longer acts a liquid and exists as discrete regions of hydrocarbon (termed residual hydrocarbons) in association with the ...

357

Spatial Mapping of Lead, Arsenic, Iron, and Polycyclic Aromatic Hydrocarbon Soil Contamination in Sydney, Nova Scotia: Community Impact From the Coke Ovens and Steel Plant  

Microsoft Academic Search

This paper presents spatial maps of the arsenic, lead, and polycyclic aromatic hydrocarbon (PAH) soil contamination in Sydney, Nova Scotia, Canada. The spatial maps were designed to create exposure cohorts to help understand the observed increase in health effects. To assess whether contamination can be a proxy for exposures, the following hypothesis was tested: residential soils were impacted by the

Timothy W. Lambert; Jennifer Boehmer; Jason Feltham; Lindsay Guyn; Rizwan Shahid

2011-01-01

358

Immunoquantitation and Microsomal Monooxygenase Activities of Hepatic Cytochromes P4501A and P4502B and Chlorinated Hydrocarbon Contaminant Levels in Polar Bear ( Ursus maritimus)  

Microsoft Academic Search

Contamination of the Arctic ecosystem by anthropogenic compounds has resulted in exposure of polar bear (Ursus maritimus) to lipophilic chlorinated hydrocarbon contaminants (CHCs) accumulated through the marine food web. Liver samples were collected from 16 adult male polar bears in the Canadian arctic and subjected to chemical analysis for CHCs and metabolites, determination of alkoxyresorufinO-dealkylase activities, and immunoquantitation of cytochrome

Robert J. Letcher; Ross J. Norstrom; Song Lin; Malcolm A. Ramsay; Stelvio M. Bandiera

1996-01-01

359

Subsurface geology of the Warfield structures in southwestern West Virginia: Implications for tectonic deformation and hydrocarbon exploration in the Central Appalachian basin  

SciTech Connect

Data from over 6000 wells and five multichannel reflection seismic lines were used to constrain the subsurface geometry of the Warfield structures in southwestern West Virginia within the central Appalachian basin. Based on their vertical differences in geometry and structural styles, we divided the Warfield structures into shallow (above the Devonian Onondaga Limestone), intermediate (between the Devonian Onondaga Limestone and the Silurian Tuscarora Sandstone), and deep (below the Ordovician Trenton horizon) structural levels. Shallow structures are related to the Alleghanian deformation above the major detachment horizon of the Devonian shales and consist of the Warfield anticline with a 91.5-m closure and southeast-dipping monoclines, which aided the northwest migration and entrapment of oil and gas. At the intermediate level, the closure of the Warfield anticline is lost because the Alleghanian deformation is obscured below the major detachment of the Devonian shales, which explains the reduced production from the Devonian and Silurian reservoirs. Deep structures are characterized by an asymmetric half graben within a continental rift system known as the Rome trough, in which a thick sequence of sedimentary rocks exists to provide sources for overlying reservoirs. Although stratigraphic traps may be associated with thickness and facies changes, the deep level is structurally unfavorable for trapping hydrocarbons. Based on changes we found in map trend, we divided the Warfield structures into a middle segment and southern and northern bends. The middle segment is parallel to the New York-Alabama lineament (a northeast-trending magnetic gradient); the southern and the northern bends are linked to the 38th parallel lineament (a west-trending fault system) and the Burning Springs-Mann Mountain lineament (a north-trending magnetic gradient), respectively.

Gao, D. [Duke Univ., Durham, NC (United States); Shumaker, R.C. [West Virginia Univ., Morgantown (United States)

1996-08-01

360

Microstructural Alteration of Hydrocarbon Contaminated Permafrost Affected Soils at the Caribou - Poker Creeks CREEL Research Watershed: Implications for Subsurface Transport.  

National Technical Information Service (NTIS)

The thermodynamic conditions within the seasonally frozen active layer overlying permafrost in the Caribou-Poker Creeks Research Watershed in Alaska are such that there is continuing translocation of water and ice, and the displacement of soil particles. ...

T. L. White P. J. Williams W. G. Rees Y. Marchand

2000-01-01

361

Development of radon-222 as a natural tracer for monitoring the remediation of NAPL contamination in the subsurface. 1998 annual progress report  

SciTech Connect

'The objective of this research is to develop a unique method of using naturally occurring radon-222 as a tracer for locating and quantitatively describing the presence of subsurface NAPL contamination. The research will evaluate using radon as an inexpensive, yet highly accurate, means of detecting NAPL contamination and assessing the effectiveness of NAPL remediation. Laboratory, field, and modeling studies are being performed to evaluate this technique, and to develop methods for its successful implementation in practice. This report summarizes work that has been accomplished after 1-year of a 3-year project. The research to date has included radon tracer tests in physical aquifer models (PAMs) and field studies at Site 300 of the Lawrence Livermore National Laboratory, CA, and Site 100D at Hanford DOE Facility, WA. The PAM tests have evaluated the ability of radon as a tracer to monitor the remediation of TCE NAPL contamination using surfactant treatment, and oxidation with permanganate. The surfactant tests were performed in collaboration with Dr. Jack Istok and Dr. Jennifer Field and their EMSP project ``In-situ, Field-Scale Evaluation of Surfactant Enhanced DNAPL Recovery Using a Single-Well-Push-Pull Test.'''' This collaboration enabled the EMSP radon project to make rapid progress. The PAM surfactant tests were performed in a radial flow geometry to simulate the push-pull-method that is being developed for surfactant field tests. The radon tests were easily incorporated into these experiments, since they simply rely on measuring the natural radon present in the subsurface fluids. Two types of radon tests were performed: (1) static tests where radon was permitted to build-up to steady-state concentrations in the pore fluids and the groundwater concentrations were monitored, and (2) dynamic tests were the radon response during push-pull surfactant tests was measured. Both methods were found to be useful in determining how NAPL remediation was progressing.'

Semprini, L.; Istok, J.

1998-06-01

362

Benzene and Naphthalene Sorption on Soil Contaminated with High Molecular Weight Residual Hydrocarbons from Unleaded Gasoline.  

National Technical Information Service (NTIS)

For complex nonaqueous phase liquids (NAPLs), the composition of the NAPL retained in the pore space of geologic material weathers until the residual NAPL no longer acts as a liquid and exists as discrete regions of hydrocarbon (termed residual hydrocarbo...

D. C. Bouchard S. C. Mravik G. B. Smith

1990-01-01

363

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

SciTech Connect

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

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

1985-01-01

364

Heavy Metals and Petroleum Hydrocarbons Contamination of Bottom Sediments of Gulf of Oman area, United Arab Emirates  

NASA Astrophysics Data System (ADS)

The concentrations of total petroleum hydrocarbons (TPH), total organic carbon (%TOC) and petroleum related heavy metals beside the grain size distribution of 4 stations in Gulf of Oman area (Khor Kalbaa , Debba ,Khor Fakan and Fujairah) , UAE were determined in the bottom sediment. Copper, zinc, nickel, lead, cadmium and vanadium concentration were found within the lowest effect, The contamination levels were found due to petrogenic origin and their sources are either weathered or highly weathered crude oils and or used lubricating oil. Their detection gives an indication of recent and continuous petroleum inputs.

Musallam, A.; El Tokhi, M.; Abed, S. Al; Mahmoud, B.

2012-04-01

365

Mineralization of polycyclic and n-heterocyclic aromatic compounds in hydrocarbon-contaminated soils  

Microsoft Academic Search

The comparative mineralization of eight polycyclic aromatic compounds in five soils collected from an abandoned coal tar refinery in eastern Ohio was determined. The soils showed differences only in total extractable hydrocarbon content of the soil chemical characteristics measured. The compounds studied included five polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and carcinogenic benz[a]anthracene and benzo[a]pyrene) and three N-heterocyclic aromatics (9H-carbazole,

Robert J. Grosser; David Warshawsky; J. Robie Vestal

1995-01-01

366

FORENSIC ANALYSIS AND SOURCE PARTITIONING OF ALIPHATIC HYDROCARBON CONTAMINATION IN LAKE MARUIT AQUATIC SEDIMENTS  

Microsoft Academic Search

Investigations of natural and\\/or engineered environmental systems require achieving a comprehensive characterization and identification of contaminants of concern. The differentiation of contaminant molecular markers (MMs) that originate from various sources is difficult when simply based only on their chemical compositions. Thus, a comprehensive forensic analysis coupled with source partitioning modeling is needed for characterizing contaminant compositions, predicting their possible transport,

TAREK A. KASSIM

367

Hydrocarbon-degradation potential in reference soils and soils contaminated with jet fuel  

Microsoft Academic Search

A series of test wells were drilled adjacent to a fuel farm and a JP-5 jet fuel pump station located at a naval air station in Maryland. At least 5 hectares of subsurface soil (to an average depth of 4m) above a local aquifer were found to contain high concentrations of petroleum compounds, including such volatile aromatics as benzene, toluene,

R. F. Lee; R. Hoeppel

1990-01-01

368

Subsurface characterization of groundwater contaminated by landfill leachate using microbial community profile data and a nonparametric decision-making process  

Microsoft Academic Search

Microbial biodiversity in groundwater and soil presents a unique opportunity for improving characterization and monitoring at sites with multiple contaminants, yet few computational methods use or incorporate these data because of their high dimensionality and variability. We present a systematic, nonparametric decision-making methodology to help characterize a water quality gradient in leachate-contaminated groundwater using only microbiological data for input. The

Andrea R. Pearce; Donna M. Rizzo; Paula J. Mouser

2011-01-01

369

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

PubMed

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

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

1999-02-01

370

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

PubMed Central

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

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

1999-01-01

371

A perspective on the benefits of the subsurface volatilization and ventilation system  

SciTech Connect

The presence of petroleum hydrocarbons, distillates, and chlorinated solvents in the subsurface environment frequently occurs from inadvertent discharges or unlawful release, and can pose a serious threat to human health and the environment. Due to strict environmental regulations, many industries are faced with significant financial and , potentially, criminal penalties associated with releases of these chemicals. In recent years, responsible industries have intensified efforts to remediate subsurface contamination problems. A new technology that addresses each aspect of subsurface contamination by volatile organic compounds (VOCs) has been developed that serves to minimize the duration and cost of remedial efforts. The Subsurface Volatilization and Ventilation System[trademark] promotes in situ destruction of contamination by biodegradation, and air circulation to enhance volatilization and vapor capture to reduce VOC mass present in the subsurface as bulk product, aqueous phase and sorbed contamination, and vapors. Because all phases of VOC contamination are addressed simultaneously, the remediation process is greatly accelerated. In addition, because SVVS[trademark] is simplistic in design and construction, remediation costs are typically well below those associated with more traditional treatment options.

Mayotte, T.J. (Brown and Root Environmental, Holt, MI (United States))

1993-10-01

372

Hepatic coenzyme Q redox balance of fishes as a potential bioindicator of environmental contamination by polycyclic aromatic hydrocarbons.  

PubMed

In this communication, we introduce a novel biomarker of aquatic contamination based on the xenobiotic-induced response of the hepatic coenzyme Q (CoQ) redox balance of fishes to polycyclic aromatic hydrocarbons (PAHs). The method is demonstrated by comparing changes in the liver CoQ redox balance with that measured using the CYP1A-based, 7-ethoxyresofurin-O-deethylase activity assay, on administration of benzo[a]pyrene (BaP) and ?-naphthoflavone (BNF) to Barramundi (Lates calcarifer). Both assays showed comparable dose-dependent effects in fish treated with BaP or BNF. Perturbation in the constitutive hepatic CoQ redox balance of fishes may thus provide a simple biomarker of aquatic PAH contamination. PMID:20739316

Hasbi, Ghitarina; de Nys, Rocky; Burns, Kathryn; Whalan, Steve; Dunlap, Walter C

2010-08-25

373

Hepatic coenzyme Q redox balance of fishes as a potential bioindicator of environmental contamination by polycyclic aromatic hydrocarbons  

PubMed Central

In this communication, we introduce a novel biomarker of aquatic contamination based on the xenobiotic-induced response of the hepatic coenzyme Q (CoQ) redox balance of fishes to polycyclic aromatic hydrocarbons (PAHs). The method is demonstrated by comparing changes in the liver CoQ redox balance with that measured using the CYP1A-based, 7-ethoxyresofurin-O-deethylase activity assay, on administration of benzo[a]pyrene (BaP) and ?-naphthoflavone (BNF) to Barramundi (Lates calcarifer). Both assays showed comparable dose-dependent effects in fish treated with BaP or BNF. Perturbation in the constitutive hepatic CoQ redox balance of fishes may thus provide a simple biomarker of aquatic PAH contamination.

Hasbi, Ghitarina; de Nys, Rocky; Burns, Kathryn; Whalan, Steve; Dunlap, Walter C.

2011-01-01

374

Three-dimensional modeling of subsurface contamination: A case study from the radio frequency-heating demonstration at the Savannah River Site  

SciTech Connect

Computer based three-dimensional modeling is a powerful tool used for visualizing and interpreting environmental data collected at the Savannah River Site (SRS). Three-dimensional modeling was used to image and interpret subsurface spatial data, primarily, changes in the movement, the accumulation, and the depletion of contaminants at the Integrated Demonstration Site (IDS), a proving ground for experimental environmental remediation technologies. Three-dimensional models are also educational tools, relaying complex environmental data to interested non-technical individuals who may be unfamiliar with the concepts and terminology involved in environmental studies. The public can draw their own conclusions of the success of the experiments after viewing the three-dimensional images set up in a chronological order. The three-dimensional grids generated during these studies can also be used to create images for visualization and animated sequences that model contamination movement. Animation puts the images of contamination distribution in motion and results in a new perspective on the effects of the remedial demonstration.

Poppy, S.P. [South Carolina Univ., Aiken, SC (United States)]|[Westinghouse Savannah River Co., Aiken, SC (United States); Eddy-Dilek, C.A.; Jarosch, T.R. [Westinghouse Savannah River Co., Aiken, SC (United States)

1994-07-01

375

Persistence and degrading activity of free and immobilised allochthonous bacteria during bioremediation of hydrocarbon-contaminated soils.  

PubMed

Rhodococcus sp. and Pseudomonas sp. bioremediation experiments were carried out using free and immobilized cells on natural carrier material (corncob powder) in order to evaluate the feasibility of its use in the bioremediation of hydrocarbon-contaminated soils. Terminal restriction fragment length polymorphism analysis was performed on the 16S rRNA gene as molecular fingerprinting method in order to assess the persistence of inoculated strains in the soil over time. Immobilized Pseudomonas cells degraded hydrocarbons more efficiently in the short term compared to the free ones. Immobilization seemed also to increase cell growth and stability in the soil. Free and immobilized Rhodococcus cells showed comparable degradation percentages, probably due to the peculiarity of Rhodococcus cells to aggregate into irregular clusters in the presence of hydrocarbons as sole carbon source. It is likely that the cells were not properly adsorbed on the porous matrix as a result of the small size of its pores. When Rhodococcus and Pseudomonas cells were co-immobilized on the matrix, a competition established between the two strains, that probably ended in the exclusion of Pseudomonas cells from the pores. The organic matrix might act as protective agent, but it also possibly limited cell density. Nevertheless, when the cells were properly adsorbed on the porous matrix, the immobilization became a suitable bioremediation strategy. PMID:22555628

Rivelli, Valentina; Franzetti, Andrea; Gandolfi, Isabella; Cordoni, Sergio; Bestetti, Giuseppina

2012-05-04

376

Synthesis and characterization of hydrophobic zeolite for the treatment of hydrocarbon contaminated ground water.  

PubMed

Hydrophobic zeolite was synthesized, modified and characterized for its suitability as a permeable reactive barrier (PRB) material for treatment of hydrocarbons in groundwater. Batch sorption tests were performed along with a number of standard characterization techniques. High and low ionic strength and pH tests were also conducted to determine their impact on hydrocarbon uptake. Further ion exchange tests were conducted to determine the potential for the zeolite to act as both a hydrocarbon capture material and nutrient a delivery system for bioremediation. The zeolite was coated with octadecyltrichlorosilane (C18) to change its surface properties. The results of the surface characterization tests showed that the underlying zeolite structure was largely unaffected by the coating. TGA measurements showed a reactive carbon content of 1-2%. Hydrocarbon (o-xylene and naphthalene) sorption isotherms results compared well with the behaviour of similar materials investigated by other researchers. Ionic strength and pH had little effect on hydrocarbon sorption and the treated zeolite had an ion exchange capacity of 0.3 mequiv./g, indicating it could be utilised as a nutrient source in PRBs. Recycle tests indicated that the zeolite could be used cleaned and reused at least three times without significant reduction in treatment effectiveness. PMID:20688431

Northcott, Kathy A; Bacus, Joannelle; Taya, Naoyuki; Komatsu, Yu; Perera, Jilska M; Stevens, Geoffrey W

2010-07-16

377

Hydrocarbon Exploration  

NSDL National Science Digital Library

To detect the hydrocarbon reservoir, structure traps should be detected. Seismic reflection profiles can be used to illustrate the structure image for the subsurface layers and hence, find out structure traps for oil. key words: Seismic reflection profiles, structural traps, oil potentialities,...

Tarabees, Elhamy

378

Inhibitory effect of aged-petroleum hydrocarbons on the survival of inoculated microorganism in a crude-oil contaminated site.  

PubMed

We studied the effects of aged total petroleum hydrocarbons (aged TPH) on the survival of allochthonous diesel-degrading Rhodococcus sp. strain YS-7 in both laboratory and field investigations. The aged TPH extracted from a crude oil-contaminated site were fractionized by thin-layer chromatography/flame ionization detection (TLC/FID). The three fractions identified were saturated aliphatic (SA), aromatic hydrocarbon (AH), and asphaltene-resin (AR). The ratio and composition of the separated fractions in the aged TPH were quite different from the crude-oil fractions. In the aged TPH, the SA and AH fractions were reduced and the AR fraction was dramatically increased compared to crude oil. The SA and AH fractions (2 mg/L each) of the aged TPH inhibited the growth of strain YS-7. Unexpectedly, the AR fraction had no effect on the survival of strain YS-7. However, crude oil (1,000 mg/L) did not inhibit the growth of strain YS-7. When strain YS-7 was inoculated into an aged crude oil-contaminated field and its presence was monitored by fluorescent in situ hybridization (FISH), we discovered that it had disappeared on 36 days after the inoculation. For the first time, this study has demonstrated that the SA and AH fractions in aged TPH are more toxic to an allochthonous diesel-degrading strain than the AR fraction. PMID:20075636

Kang, Yoon-Suk; Park, Youn Jong; Jung, Jaejoon; Park, Woojun

2009-12-01

379

Impact of bacterial and fungal processes on 14C-hexadecane mineralisation in weathered hydrocarbon contaminated soil.  

PubMed

In this study, the impact of bacterial and fungal processes on (14)C-hexadecane mineralisation was investigated in weathered hydrocarbon contaminated soil. The extent of (14)C-hexadecane mineralisation varied depending on the bioremediation strategy employed. Under enhanced natural attenuation conditions, (14)C-hexadecane mineralisation after 98 days was 8.5 ± 3.7% compared to <1.2% without nitrogen and phosphorus additions. (14)C-hexadecane mineralisation was further enhanced through Tween 80 amendments (28.9 ± 2.4%) which also promoted the growth of a Phanerochaete chyrsosporium fungal mat. Although fungal growth in weathered hydrocarbon contaminated soil could be promoted through supplementing additional carbon sources (Tween 80, sawdust, compost, pea straw), fungal (14)C-hexadecane mineralisation was negligible when sodium azide was added to soil microcosms to inhibit bacterial activity. In contrast, when fungal activity was inhibited through nystatin additions, (14)C-hexadecane mineralisation ranged from 6.5 ± 0.2 to 35.8 ± 3.8% after 98 days depending on the supplied amendment. Bacteria inhibition with sodium azide resulted in a reduction in bacterial diversity (33-37%) compared to microcosms supplemented with nystatin or microcosms without inhibitory supplements. However, alkB bacterial groups were undetected in sodium azide supplemented microcosms, highlighting the important role of this bacterial group in (14)C-hexadecane mineralisation. PMID:22154183

Adetutu, Eric M; Ball, Andy S; Weber, John; Aleer, Samuel; Dandie, Catherine E; Juhasz, Albert L

2011-12-07

380

Natural attenuation of fuel hydrocarbon contaminants: Hydraulic conductivity dependency of biodegradation rates in a field case study  

SciTech Connect

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene (B), toluene (T), ethyl benzene (E), and xylene (X). The second, a reactive pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rate constants associated with each of the K zones. In both the mass loss model and the reactive pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distributions is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.

Lu, Guoping; Zheng, Chunmiao

2003-07-15

381

Natural Attenuation of Fuel Hydrocarbon Contaminants: Correlation of Biodegradation with Hydraulic Conductivity in a Field Case Study  

SciTech Connect

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi, USA. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene (B), toluene (T), ethyl benzene (E), and xylene (X). The second, a reactive pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rate constants associated with each of the K zones. In both the mass loss model and the reactive pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distributions is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.

Lu, Guoping; Zheng, Chunmiao

2003-10-15

382

Identifying the sources of subsurface contamination at the Hanford site in Washington using high-precision uranium isotopic measurements  

SciTech Connect

In the mid-1990s, a groundwater plume of uranium (U) was detected in monitoring wells in the B-BX-BY Waste Management Area (WMA) at the Hanford Site in Washington. This area has been used since the late 1940s to store high-level radioactive waste and other products of U fuel-rod processing. Using multiple collector ICP source magnetic sector mass spectrometry (MC ICPMS) high precision uranium isotopic analyses were conducted of samples of vadose zone contamination and of groundwater. The ratios {sup 236}U/{sup 238}U, {sup 234}U/{sup 238}U and {sup 238}U/{sup 235}U are used to distinguish contaminant sources. Based on the isotopic data, the source of the groundwater contamination appears to be related to a 1951 overflow event at tank BX-102 that spilled high level U waste into the vadose zone. The U isotopic variation of the groundwater plume is a result of mixing between contaminant U from this spill and natural background U. Vadose zone U contamination at tank B-110 likely predates the recorded tank leak and can be ruled out as a source of groundwater contamination, based on the U isotopic composition. The locus of vadose zone contamination is displaced from the initial locus of groundwater contamination, indicating that lateral migration in the vadose zone was at least 8 times greater than vertical migration. The time evolution of the groundwater plume suggests an average U migration rate of {approx}0.7-0.8 m/day showing slight retardation relative to a ground water flow of {approx}1 m/day.

Christensen, John N.; Dresel, P. Evan; Conrad, Mark E.; Maher, Kate; DePaolo, Donald J.

2004-03-30

383

Bioremediation of petroleum hydrocarbon-contaminated soil by composting in biopiles  

Microsoft Academic Search

Composting of contaminated soil in biopiles is an ex situ technology, where organic matter such as bark chips are added to contaminated soil as a bulking agent. Composting of lubricating oil-contaminated soil was performed in field scale (5×40 m3) using bark chips as the bulking agent, and two commercially available mixed microbial inocula as well as the effect of the

K. S. Jørgensen; J. Puustinen; A.-M. Suortti

2000-01-01

384

Deep subsurface microbial processes  

NASA Astrophysics Data System (ADS)

Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of other habitats, the study of deep subsurface microbiology is still in its infancy.

Lovley, Derek R.; Chapelle, Francis H.

1995-01-01

385

Olivibacter oleidegradans sp. nov., a hydrocarbon-degrading bacterium isolated from a biofilter clean-up facility on a hydrocarbon-contaminated site.  

PubMed

A novel hydrocarbon-degrading, Gram-negative, obligately aerobic, non-motile, non-sporulating, rod-shaped bacterium, designated strain TBF2/20.2(T), was isolated from a biofilter clean-up facility set up on a hydrocarbon-contaminated site in Hungary. It was characterized by using a polyphasic approach to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate is affiliated with the genus Olivibacter in the family Sphingobacteriaceae. It was found to be related most closely to Olivibacter ginsengisoli Gsoil 060(T) (93.3% 16S rRNA gene sequence similarity). Strain TBF2/20.2(T) grew at pH 6-9 (optimally at pH 6.5-7.0) and at 15-42 °C (optimally at 30-37 °C). The major fatty acids were iso-C(15:0) (39.4%), summed feature 3 (iso-C(15:0) 2-OH and/or C(16:1)?7c; 26.0%), iso-C(17:0) 3-OH (14.5%) and C(16:0) (4.5%). The major menaquinone was MK-7 and the predominant polar lipid was phosphatidylethanolamine. The DNA G+C content of strain TBF2/20.2(T) was 41.2 mol%. Physiological and chemotaxonomic data further confirmed the distinctiveness of strain TBF2/20.2(T) from recognized members of the genus Olivibacter. Thus, strain TBF2/20.2(T) is considered to represent a novel species of the genus Olivibacter, for which the name Olivibacter oleidegradans sp. nov. is proposed. The type strain is TBF2/20.2(T) (=NCAIM B 02393(T) =CCM 7765(T)). PMID:21257685

Szabó, István; Szoboszlay, Sándor; Kriszt, Balázs; Háhn, Judit; Harkai, Péter; Baka, Erzsébet; Táncsics, András; Kaszab, Edit; Privler, Zoltán; Kukolya, József

2011-01-21

386

Bioremediation of hydrocarbon-contaminated soils and groundwater in northern climates  

Microsoft Academic Search

A field demonstration and research project was conducted in Fairbanks, Alaska, to demonstrate, evaluate, and document the construction and operation of three selected bioremediation technologies-landfarming, recirculating leachbeds, and infiltration galleries. Landfarming involves adding water and nutrients to contaminated soil to stimulate microbial activity and contaminant degradation. Infiltration galleries are dynamic in-situ treatment systems designed to stimulate microbial activity and subsequent

Charles M. Reynolds; W. Alan Braley; Michael D. Travis; Lawrence B. Perry; Iskandar K. Iskandar

1998-01-01

387

Advanced fuel hydrocarbon remediation national test location - biocell treatment of petroleum contaminated soils  

Microsoft Academic Search

Biocells are engineered systems that use naturally occurring microbes to degrade fuels and oils into simpler, nonhazardous, and nontoxic compounds. Biocells are able to treat soils contaminated with petroleum based fuels and lubricants, including diesel, jet fuel, and lubricating and hydraulic oils. The microbes use the contaminants as a food source and thus destroy them. By carefully monitoring and controlling

J. Heath; E. Lory

1997-01-01

388

PHOTOACTIVATED TOXICITY IN AMPHIPODS COLLECTED FROM POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SITES  

EPA Science Inventory

The risk of photo-activated PAH toxicity in contaminated aquatic systems has not been well characterized. To better indicate this potential, amphipods (Gammarus spp.) were collected from two PAH contaminated sites (Hog Island and USX), as well as a reference site (Chipmunk Cove)...

389

INEEL Subregional Conceptual Model Report Volume 2: Summary of Existing Knowledge of Geochemical Influences on the Fate and Transport of Contaminants in the Subsurface at the INEEL  

SciTech Connect

This document summarizes previous descriptions of geochemical system conceptual models for the vadose zone and groundwater zone (aquifer) beneath the Idaho National Engineering and Environmental Laboratory (INEEL). The primary focus is on groundwater because contaminants derived from wastes disposed at INEEL are present in groundwater, groundwater provides a pathway for potential migration to receptors, and because geochemical characteristics in and processes in the aquifer can substantially affect the movement, attenuation, and toxicity of contaminants. The secondary emphasis is perched water bodies in the vadose zone. Perched water eventually reaches the regional groundwater system, and thus processes that affect contaminants in the perched water bodies are important relative to the migration of contaminants into groundwater. Similarly, processes that affect solutes during transport from nearsurface disposal facilities downward through the vadose zone to the aquifer are relevant. Sediments in the vadose zone can affect both water and solute transport by restricting the downward migration of water sufficiently that a perched water body forms, and by retarding solute migration via ion exchange. Geochemical conceptual models have been prepared by a variety of researchers for different purposes. They have been published in documents prepared by INEEL contractors, the United States Geological Survey (USGS), academic researchers, and others. The documents themselves are INEEL and USGS reports, and articles in technical journals. The documents reviewed were selected from citation lists generated by searching the INEEL Technical Library, the INEEL Environmental Restoration Optical Imaging System, and the ISI Web of Science databases. The citation lists were generated using the keywords ground water, groundwater, chemistry, geochemistry, contaminant, INEL, INEEL, and Idaho. In addition, a list of USGS documents that pertain to the INEEL was obtained and manually searched. The documents that appeared to be the most pertinent were selected from further review. These documents are tabulated in the citation list. This report summarizes existing geochemical conceptual models, but does not attempt to generate a new conceptual model or select the ''right'' model. This document is organized as follows. Geochemical models are described in general in Section 2. Geochemical processes that control the transport and fate of contaminants introduced into groundwater are described in Section 3. The natural geochemistry of the Eastern Snake River Plain Aquifer (SRPA) is described in Section 4. The effect of waste disposal on the INEEL subsurface is described in Section 5. The geochemical behavior of the major contaminants is described in Section 6. Section 7 describes the site-specific geochemical models developed for various INEEL facilities.

Paul L. Wichlacz; Robert C. Starr; Brennon Orr

2003-09-01

390

Sorption of selected polycyclic aromatic hydrocarbons on soils in oil-contaminated systems  

Microsoft Academic Search

The adsorption and desorption behaviour of selected polycyclic aromatic hydrocarbons (PAHs) on different soils was investigated by static and dynamic methods. On the basis of a system including the four phases of soil, water, oil adsorbed and oil in emulsion, a model for the description of the adsorption behaviour in the presence of oil was developed. In systems without oil

T Walter; H. J Ederer; C Först; L Stieglitz

2000-01-01

391

Phototoxic response of Lumbriculus variegatus to sediments contaminated by polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The toxicity of certain polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms can be greatly increased upon exposure of the organisms to ultraviolet (UV) radiation present in sunlight. The phenomenon of photoactivation of PAHs had received some attention in the laboratory; however, evaluation of the photoinduced toxicity of PAHs in field settings has been limited. In these studies, in situ chambers

Philip D. Monson; Gerald T. Ankley; Patricia A. Kosian

1995-01-01

392

POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL  

EPA Science Inventory

Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

393

Slurry-Phase Ozonation for Remediation of Sediments Contaminated by Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic, persistent, bioaccumulating organic compounds containing two or more fused aromatic rings. They are listed by the U.S. Environmental Protection Agency as priority pollutants because of their carcinogenicity and toxicity. Employing ozonation as a remediation technique, this work investigated the treatability of a sediment sample from a freshwater boat slip subjected to

Yu Zeng; P. K. Andrew Hong

2002-01-01

394

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by Cladosporium sphaerospermum isolated from an aged PAH contaminated soil  

Microsoft Academic Search

The ability of a Deuteromycete fungus, Cladosporium sphaerospermum, previously isolated from soil of an aged gas manufacturing plant, to degrade polycyclic aromatic hydrocarbons was investigated. This strain was able to degrade PAHs in non-sterile soils (average 23%), including high molecular weight PAHs, after 4 weeks of incubation. In a microcosm experiment, PAH depletion was clearly correlated to fungal establishment. In

Olivier Potin; Etienne Veignie; Catherine Rafin

2004-01-01

395

Evidence for microbial enhanced electrical conductivity in hydrocarbon-contaminated sediments  

NASA Astrophysics Data System (ADS)

Bulk electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale laboratory experiment consisting of biotic contaminated and uncontaminated columns. Population numbers of oil degrading microorganisms increased with a clear pattern of depth zonation within the contaminated column not observed in the uncontaminated column. Microbial community structure determined from ribosomal DNA intergenic spacer analysis showed a highly specialized microbial community in the contaminated column. The contaminated column showed temporal increases in bulk conductivity, dissolved inorganic carbon, and calcium, suggesting that the high bulk conductivity is due to enhanced mineral weathering from microbial activity. The greatest change in bulk conductivity occurred in sediments above the water table saturated with diesel. Variations in electrical conductivity magnitude and microbial populations and their depth distribution in the contaminated column are similar to field observations. The results of this study suggest that geophysical methodologies may potentially be used to investigate microbial activity.

Atekwana, Estella A.; Atekwana, Eliot A.; Werkema, D. Dale; Allen, Jonathan P.; Smart, Laura A.; Duris, Joseph W.; Cassidy, Daniel P.; Sauck, William A.; Rossbach, Silvia

2004-12-01

396

Chlorinated hydrocarbon contamination in osprey eggs and nestlings from the Canadian Great Lakes basin, 1991-1995.  

PubMed

Populations of osprey (Pandion haliaetus) in the Great Lakes basin declined dramatically during the 1950s-1970s due largely to adverse effects of persistent chlorinated hydrocarbons, ingested in their fish prey, on eggshell thickness and adult survival. Nevertheless, these contaminants were not measured in osprey tissues during the decades of decline on the Canadian Great Lakes. Between 1991 and 1995, we monitored recovering osprey populations on the Great Lakes, including Georgian Bay and the St. Marys River area on Lake Huron and the St. Lawrence Islands National Park, as well as at two inland sites within the basin. Current OC levels, even from the most contaminated lakes, were typically lower than those associated with reproductive effects. DDE levels in fresh eggs averaged 1.2-2.9 microg/g, well below the 4.2 microg/g level associated with significant eggshell thinning and shell breakage. Nevertheless, a proportion of eggs from all study areas did exceed this level. PCB levels in eggs seldom exceeded 5 microg/g except in one lake of high breeding density in the Kawartha Lakes inland study area, where the mean sum PCB level was 7.1 microg/g and the maximum concentration measured was 26.5 microg/g. On average, mean reproductive output (0.78-2.75 young per occupied nest) of breeding populations in Great Lakes basin study areas exceeded the threshold of 0.8 young thought necessary to maintain stable populations. We concluded that, although eggs and especially nestling plasma, are useful in reflecting local contaminant levels, ospreys are relatively insensitive, at least at the population level, to health effects of current levels of chlorinated hydrocarbons on the Canadian Great Lakes. PMID:12739869

Martin, Pamela A; De Solla, Shane R; Ewins, Peter

397

Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons.  

PubMed

Environmentally persistent aromatic hydrocarbons known as unresolved complex mixtures (UCMs) derived from crude oil can be accumulated by, and elicit toxicological responses in, marine organisms (e.g. mussels, Mytilus edulis). Comprehensive two-dimensional gas chromatography time-of-flight mass-spectrometry (GCxGC-ToF-MS) previously revealed that these UCMs included highly branched alkylated aromatic hydrocarbons. Here, the effects of biodegradation on the toxicity and chemical composition of an aromatic UCM hydrocarbon fraction isolated from Tia Juana Pesado (TJP) crude oil were examined. 48h exposure of mussels to the aromatic hydrocarbon fraction (F2) resulted in tissue concentrations of 900microgg(-1) (dry wt.) and approximately 45% decrease in clearance rate. Over 90% of the hydrocarbon burden corresponded to an UCM. Following a 5day recovery period, GCxGC-ToF-MS analysis of the tissues indicated depuration of most accumulated hydrocarbons and clearance rates returned to those observed in controls. To assess the potential of biodegradation to reduce UCM toxicity, TJP F2 was exposed to bacteria isolated from Whitley Bay, UK, for 46days. Mussels exposed to the undegraded TJP F2 from the abiotic control exhibited a reduction in clearance rate comparable with values for the pure crude oil TJP F2. Clearance rates of mussels exposed to biodegraded TJP F2 were statistically similar to seawater controls, suggesting biodegradation had reduced the TJP F2 toxicity. GCxGC-ToF-MS analysis revealed the same compound groups in the tissue of mussels exposed to pure TJP F2, undegraded TJP F2 and biodegraded TJP F2 samples; however >300 fewer compounds were observed in the biodegraded (954 compounds) compared to the undegraded TJP F2 (1261). The compound distributions were markedly different, possibly accounting for the decrease in toxicity. Extraction and analysis of pelleted bacterial cell material revealed that a significant proportion of the TJP F2 had adsorbed onto the cells. Thus extreme care must be taken in interpreting biodegradation data from recalcitrant UCM hydrocarbons. PMID:20542318

Frenzel, Max; Scarlett, Alan; Rowland, Steven J; Galloway, Tamara S; Burton, Sara K; Lappin-Scott, Hilary M; Booth, Andy M

2010-06-12

398

Microbial Community Dynamics in Uranium Contaminated Subsurface Sediments under Biostimulated Conditions with High Nitrate and Nickel Pressure  

SciTech Connect

The subsurface at the Oak Ridge Field Research Center represents an extreme and diverse geochemical environment that places different stresses on the endogenous microbial communities, including low pH, elevated nitrate concentrations, and the occurrence of heavy metals and radionuclides, including hexavalent uranium [U(VI)]. The in situ immobilization of U(VI) in the aquifer can be achieved through microbial reduction to relatively insoluble U(IV). However, a high redox potential due to the presence of nitrate and the toxicity of heavy metals will impede this process. Our aim is to test biostimulation of the endogenous microbial communities to improve nitrate reduction and subsequent U(VI) reduction under conditions of elevated heavy metals.

Moreels,D.; Crosson, G.; Garafola, C.; Monteleone, D.; Taghavi, S.; Fitts, J.; van der Lelie, D.

2008-01-01