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1

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

USGS Publications Warehouse

[1] 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. Copyright 2005 by the American Geophysical Union.

Amos, R.T.; Mayer, K.U.; Bekins, B.A.; Delin, G.N.; Williams, R.L.

2005-01-01

2

Modeling Subsurface Transport of Petroleum Hydrocarbons  

NSDL National Science Digital Library

This U.S. EPA website contains information on the modeling of subsurface transport of petroleum hydrocarbons and other contaminants. There are a few course modules on the fate and transport of contaminants. There are also OnSite on-line calculators for site-specific assessment calculations.

2008-03-11

3

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

NASA Astrophysics Data System (ADS)

In the framework of the EU FP7 project ModelPROBE, broadband spectral induced polarization (SIP) measurements were conducted at a former hydrogenation plant in Zeitz for the characterization of a hydrocarbon contaminant plume. In the source area total concentrations of BTEX contaminants partly exceed 1.5 g/l. Previous studies at the laboratory scale have demonstrated the sensitivity of SIP measurements to different concentrations of organic minerals; however, only few studies have been conducted at the field scale. The aim of this study was to investigate the potential of SIP imaging to delineate areas with different BTEX concentrations. SIP measurements were performed in the frequency range from 60 mHz to 1 kHz along a 120 m profile across the area of the former hydrogenation plant. At a later stage, a trench was excavated along the location of the profile in order to remove pipes, foundations and different sources of anthropogenic noise associated with the hydrogenation plant. Thereafter, SIP measurements were repeated inside the trench to study the effect of anthropogenic noise on the SIP images. Computed images for the data collected before and after the excavation of the trench show similar results validating the proposed approach even in the presence of anthropogenic noise. SIP images, for frequencies below 100 Hz, exhibit two main anomalies: low phase shift values (~ 5 mrad) for locations with free phase product (BTEX concentrations > 1.7 g/l); whereas relatively high polarization values (> 10 mrad) were observed for lower BTEX concentrations (1 - 1.7 g/l). Moreover, the spectral response of the areas where free phase product was detected reveals a flattened spectrum; while the areas with lower concentrations exhibit a typical Cole-Cole response. Based on these results, SIP imaging appears to be a suitable tool to delineate source-zones at highly contaminated sites.

Flores Orozco, A.; Kemna, A.; Oberdoerster, C.; Zschornack, L.; Leven, C.; Dietrich, P.; Weiss, H.

2011-12-01

4

An evaluation of soil-gas surveying for H{sub 2}S for locating subsurface hydrocarbon contamination  

SciTech Connect

A soil-gas survey was conducted at a gasoline service station and a former fire training facility to determine if surveying for hydrogen sulfide could be useful in locating nonaqueous phase hydrocarbon fuel in the subsurface. Relative to total organic vapor, oxygen, and carbon dioxide distributions, detectable hydrogen sulfide concentrations were much more restricted to the suspected source vicinity at both sites. Appreciable levels of soil-gas hydrogen sulfide, up to 600 Vppb, were observed in areas characterized by anaerobic or microaerophilic conditions having bulk oxygen levels below 4 percent. Based on the hydrogen sulfide distribution, nonaqueous phase hydrocarbon fuel was located at each site. These results suggest that soil-gas surveying for hydrogen sulfide may help locate mobile or residual gasoline and other nonaqueous phase hydrocarbons in the subsurface.

Robbins, G.A.; McAninch, B.E.; Gavas, F.M.; Ellis, P.M.

1995-07-01

5

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

6

DELINEATION OF SUBSURFACE HYDROCARBON CONTAMINANT DISTRIBUTION USING A DIRECT PUSH RESISTIVITY METHOD  

EPA Science Inventory

A direct push resistivity method was evaluated as a complementary screening tool to provide rapid in-situ contaminant detection to aid in better defining locations for drilling, sampling, and monitoring well installation at hazardous waste sites. Nine continuous direct push resi...

7

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

PubMed

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. PMID:22784635

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

2012-08-01

8

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

9

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...

10

UNDERSTANDING THE FATE OF PETROLEUM HYDROCARBONS IN THE SUBSURFACE ENVIRONMENT  

EPA Science Inventory

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. his paper provides extensive details...

11

Containment of subsurface contaminants  

DOEpatents

A barrier is disclosed 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. 5 figs.

Corey, J.C.

1994-09-06

12

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

13

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

PubMed

There is an imperative need for a chemical sensor capable of remote, in situ, long-term monitoring of chemical species at sites containing toxic chemical spills, specifically at chemical waste dumps, landfills, and locations with underground storage tanks. In the current research, a series of experiments were conducted measuring the near-infrared optical absorption of alkanes, aromatics, and chlorinated hydrocarbons. A spectral library was then developed to characterize the optical spectra of liquid hydrocarbons. Near-infrared analysis was chosen due to compatibility with optical fibers. The goal was to differentiate between classes of hydrocarbons and to also discriminate between compounds within a class of similar molecular structures. It was observed that unique absorption spectra can be obtained for each hydrocarbon, and this uniqueness can be used to discriminate between hydrocarbons from different families. Statistical analyses, namely, principal component analysis (PCA) and correlation coefficient (Spearman and Pearson methods), were attempted to match absorption spectra from an unknown hydrocarbon with the database with limited success. An algorithm was subsequently written to identify the characteristic peaks of each hydrocarbon that could be used to match data from an unknown chemical species with the database. PMID:24445930

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

2014-05-01

14

Subsurface fate of spilled petroleum hydrocarbons in continuous permafrost  

USGS Publications Warehouse

Accidental releases of approximately 2000 m3 of fuel have resulted in subsurface contamination adjacent to Imikpuk Lake, a drinking-water source near Barrow, AK. This paper presents a conceptual model of the distribution and transport of subsurface free-phase hydrocarbons at this site. The mean annual temperature in Barrow is -13 ??C, and average monthly temperatures exceed 0 ??C only during the months of June, July, and August. As a result, the region is underlain by areally continuous permafrost that extends to depths of up to 300 m and constrains subsurface hydrologic processes to a shallow zone that temporarily thaws each summer. During the 1993 and 1994 thaw seasons, the measured depth of thaw varied across the site from approximately 0.5 to 2 m. However, exploratory borings in 1995 showed that free-phase hydrocarbons were present at depths greater than 3 m, indicating that permafrost at this site is not a barrier to the vertical migration of nonaqueous-phase liquids. In 1996, a subsurface containment barrier was installed to prevent lateral movement of contaminated water to Imikpuk Lake, and a recovery trench was excavated upgradient of the barrier to facilitate removal of free-phase hydrocarbons. Free-phase hydrocarbons were recovered from the trench during 1996, 1997, and 1998. Recovery rates diminished over this time, and in 1999, no further product was recovered and the recovery operation was halted. Subsequent exploratory borings in 2001 and 2002 have revealed that some product remains in the subsurface. Data indicate that this remaining product exists in small discrete pockets or very thin layers of hydrocarbon floating on brine. These small reservoirs appear to be isolated from one another by relatively impermeable permafrost. Published by Elsevier B.V.

McCarthy, K.; Walker, L.; Vigoren, L.

2004-01-01

15

Microbial processes and subsurface contaminants  

NASA Astrophysics Data System (ADS)

A Chapman Conference entitled “Microbial Processes in the Transport, Fate, and In Situ Treatment of Subsurface Contaminants” was held in Snowbird, Utah, October 1-3, 1986. Members of the program committee and session chairmen were Lenore Clesceri (Rensselaer Polytechnic Institute, Troy, N.Y.), David Gibson (University of Texas, Austin), James Mercer (GeoTrans, Inc., Herndon , Va.), Donald Michelsen (Virginia Polytechnic Institute and State University, Blacksburg), Fred Molz (Auburn University, Auburn, Ala.), Bruce Rittman (University of Illinois, Urbana), Gary Sayler (University of Tennessee, Knoxville), and John T. Wilson (U.S. Environmental Protection Agency, Ada, Okla.). The following report attempts to highlight the six sessions that constituted the conference. For additional information, including a bound summary and abstracts, contact Fred J. Molz, Civil Engineering Department, Auburn University, AL 36849 (telephone: 205-826-4321).

Molz, Fred J.

16

OPPORTUNITIES FOR BIORECLAMATION OF AQUIFERS CONTAMINATED WITH PETROLEUM HYDROCARBONS  

EPA Science Inventory

Petroleum-derived hydrocarbons are an important class of ground water contaminants. Spills of hydrocarbons often produce regions in the subsurface that retain the spilled material trapped as an oily phase. When ground water infiltrates the oily material, the more water-soluble hy...

17

EVOLVING CONCEPTS OF SUBSURFACE CONTAMINANT TRANSPORT  

EPA Science Inventory

Currently, a large gap exists between theoretical advances in the understanding of how various natural processes affect subsurface contaminant transport, and our ability to translate those advances into practical applications. The lack of truly representative and reliable field t...

18

MODELING CONTAMINANT TRANSPORT THROUGH SUBSURFACE SYSTEMS  

EPA Science Inventory

Modeling of contaminant transport through soil to groundwater to a receptor requires that consideration he given to the many processes which control the transport and fate of chemical constituents in the subsurface environment. hese processes include volatilization, degradation, ...

19

MODELING CONTAMINANT TRANSPORT THROUGH SUBSURFACE SYSTEMS  

EPA Science Inventory

Modeling of contaminant transport through soil to groundwater to a receptor requires that consideration be given to the many processes which control the transport and fate of chemical constituents in the subsurface environment. These processes include volatilization, degradation,...

20

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.

Pemberton, Bradley E. (Aiken, SC); May, Christopher P. (Fairfax, VA); Rossabi, Joseph (Aiken, SC)

1997-01-01

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

UNDERSTANDING THE FATE OF PETROLEUM HYDROCARBONS IN THE SUBSURFACE ENVIRONMENT  

EPA Science Inventory

Sinca a significant number of the two or more million underground storage tank (UST) systems used for petroleum products leak, their cleanup poses a major environmental challenge. Our understnading of the fate of petroleum hydrocarbons in the subsurface environment is critical t...

23

Potential for Aerobic and Anaerobic Biodegradation of Petroleum Hydrocarbons in Boreal Subsurface  

Microsoft Academic Search

We studied the role of aerobic and anaerobic petroleum hydrocarbon degradation ata boreal, light-weight fuel and lubrication oil contaminated site undergoing naturalattenuation. At the site, anoxic conditions prevailed with high concentrations ofCH4 (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

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

2004-01-01

24

Plant-enhanced subsurface bioremediation of nonvolatile hydrocarbons  

Microsoft Academic Search

In recent years, phytoremediation, i.e., the use of plants to clean up soils contaminated with organics, has become a promising new area of research, particularly for in-situ cleanup of large volumes of slightly contaminated soils. A model that can be used as a predictive tool in phytoremediation operations was developed to simulate the transport and fate of a residual hydrocarbon

Yoon-Young Chang; M. Yavuz Corapcioglu

1998-01-01

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

Plant-enhanced subsurface bioremediation of nonvolatile hydrocarbons  

SciTech Connect

In recent years, phytoremediation, i.e., the use of plants to clean up soils contaminated with organics, has become a promising new area of research, particularly for in-situ cleanup of large volumes of slightly contaminated soils. A model that can be used as a predictive tool in phytoremediation operations was developed to simulate the transport and fate of a residual hydrocarbon contaminant interacting with plant roots in a partially saturated soil. Time-specific distribution of root quantity through soil, as well as root uptake of soil water and hydrocarbon, was incorporated into the model. In addition, the microbial activity in the soil rhizosphere was modeled with a biofilm theory. A sandy loam, which is dominate in soils of agricultural importance, was selected for simulations. Cotton, which has well-documented plant properties, was used as the model plant. Model parameters involving root growth and root distribution were obtained from the actual field data reported in the literature and ranges of reported literature values were used to obtain a realistic simulation of a phytoremediation operation. Following the verification of the root growth model with published experimental data, it has been demonstrated that plant characteristics such as the root radius are more dominant than contaminant properties in the overall rate of phytoremediation operation. The simulation results showed enhanced biodegradation of a hydrocarbon contaminant mostly because of increased biofilm metabolism of organic contaminants in a growing root system of cotton. Simulations also show that a high mean daily root-water uptake rate increases the contaminant retardation factors because of the resulting low water content. The ability to simulate the fate of a hydrocarbon contaminant is essential in designing technically efficient and cost-effective, plant-aided remedial strategies and in evaluating the effectiveness of a proposed phytoremediation scheme.

Chang, Y.Y. [Korea Inst. of Science and Technology Environmental Center, Seoul (Korea, Republic of); Corapcioglu, M.Y. [Texas A and M Univ., College Station, TX (United States). Dept. of Civil Engineering

1998-02-01

27

Enhanced bioremediation of subsurface contamination: Enzyme recruitment and redesign  

SciTech Connect

Subsurface systems containing radionuclide, heavy metal, and organic wastes must be carefully attended to avoid further impacts to the environment or exposures to human populations. It is appropriate, therefore, to invest in basic research to develop the requisite tools and methods for addressing complex cleanup problems. The rational modification of subsurface microoganisms by enzyme recruitment and enzyme design, in concert with engineered systems for delivery of microorganisms and nutrients to the contaminated zone, are potentially useful tools in the spectrum of approaches that will be required for successful remediation of deep subsurface contamination.

Brockman, F.J.; Ornstein, R.L.

1991-12-01

28

Fate and transport of ethylenediaminetetraacetate chelated contaminants in subsurface environments  

Microsoft Academic Search

Decontamination efforts during weapons production has historically involved the generation of mixed waste that was composed of organically chelated radionuclides. Waste disposal has traditionally involved shallow land burial, and not until recently has the subsurface migration of the organically complexed contaminants (co-contaminants) become a significant concern. The objective of this study was to provide an improved understanding of the geochemical

P. M. Jardine; D. L. Taylor

1995-01-01

29

Investigating hydrocarbon contamination using ground penetrating radar  

SciTech Connect

The increasing costs of remediating contaminated sites has stimulated research for cost reducing techniques in soil investigation and clean-up techniques. Under the traditional approach soil borings and groundwater wells are used to investigate contaminated soil. These are useful tools to determine the amount and characteristics of the contamination, but they are inefficient and costly in providing information on the location and extent of contamination as they only give information on one point. This often leads to uncertainty in estimating clean-up costs or, even worse, to unsuccessful clean-ups. MAP Environmental Research has developed a technology using Ground Penetrating Radar (GPR) in combination with in-house developed software to locate and define the extent of hydrocarbon contamination. With this technology, the quality of site investigation is increased while costs are reduced. Since 1994 MAP has been improving its technology and has applied it to over 100 projects, which all have been checked afterwards by conventional drilling. This paper gives some general characteristics of the method and presents a case study. The emphasis of this paper lies on the practical application of GPR to hydrocarbon contamination detection.

Roest, P.B. van der; Brasser, D.J.S.; Wagebaert, A.P.J.; Stam, P.H. [MAP Environmental Research BV, Arnhem (Netherlands)

1996-12-31

30

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...

31

A BIOVENTING APPROACH TO REMEDIATE A GASONLINE CONTAMINATED SUBSURFACE  

EPA Science Inventory

Bioventing is a subsurface process using an air stream to enhance biodegradation of oily contaminants. wo pilot-scale bioventing systems were installed at a field site. rocess operations began in October 1990. he field site is located at an air station. pill in 1969 of about 100,...

32

Subsurface characterization of groundwater contaminated by landfill leachate using microbial community profile  

E-print Network

Subsurface characterization of groundwater contaminated by landfill leachate using microbial. In this landfill leachate application, the weighted SOM assembles the microbial community data from monitoring (2011), Subsurface characterization of groundwater contaminated by landfill leachate using microbial

Vermont, University of

33

INVESTIGATING THE GEOELECTRICAL RESPONSE OF HYDROCARBON CONTAMINATION UNDERGOING BIODEGRADATION  

EPA Science Inventory

A newly proposed geoelectrical model for hydrocarbon contaminated sites predicts high conductivities coincident with t he Contaminated zone a s opposed t o t he traditionally accepted low conductivity. The model attributes the high conductivities to mineral weathering resulti...

34

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

35

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

2005-10-01

36

Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface  

SciTech Connect

Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene, phenanthrene, 2,3-benzofluorene, 2-methyl naphthalene, 2,3-dimethylnaphthalene, and fluoranthene in the presence of 400 mg l(-1) Tween 80. Studies involving microcosms composed of aquifer sediments showed that S. aromaticivorans B0695 could degrade phenanthrene effectively in sterile sediment and could enhance the rate at which this compound was degraded in nonsterile sediment. These findings indicate that it may be feasible to carry out (or, at least, to enhance) in situ bioremediation of phenanthrene-contaminated soils and subsurface environments with S. aromaticivorans B0695. In contrast, stra in B0695 was unable to degrade fluoranthene in microcosms containing aquifer sediments, even though it readily degraded this polynuclear aromatic hydrocarbon (PAH) in a defined liquid growth medium.

Shi, T; Fredrickson, Jim K.; Balkwill, David L.

2001-05-01

37

Geophysical techniques in the study of Hydrocarbon contamination: lab experiments  

NASA Astrophysics Data System (ADS)

Remediation of sites contaminated by hydrocarbon, due to blow out, leakage from tank or pipe and oil spill, is an environmental problem because infiltrated oil can persist in the ground for a long time and the actual method are invasive and expansive . In the last years there was a growing interest in the use of geophysical methods for environmental monitoring (Greenhouse et al., 1993; Daily and Ramirez, 1995; Lendvay et al., 1998; Atekwana et al., 2000; Chambers et al., 2004; Song et al., 2005; French et al., 2009), and there have been several recent study that relate self-potential measurements to subsurface contaminants (Perry et al., 1996; Naudet et al., 2003; Naudet et al., 2004). Infact, this method is a valid tool for site characterization and monitoring because it is sensitive to contaminant chemistry and redox processes generated by bacteria during the biodegradation phase (Atekwana et al., 2004; Naudet and Revil, 2005). Therefore the goal of this investigation is to characterize underground contaminant distributions using minimally invasive geophysical methods (electrical resistivity tomography and self-potential), in combination with hydrochemical measurements, and to develop fundamental constitutive relations between soil physical and degradation activity parameters and geophysically measurable parameters, in order to improve site remediation efficiency. These tests have been realized at a PVC pool situated in the Hydrogeosite Laboratory of CNR-IMAA. The pool is completely filled with ~ 0.80 m3 of an homogeneous medium (quartz-rich sand with a medium-high hydraulic conductivity in the order of 10-5 m/s), to simulate the space and time dynamics of an artificial aquifer; besides it has been endowed of a sensors network at surface and in borehole, to measure self-potential and electrical resistivity. The experiments consist in geophysical measurements to monitor a simulated oil spill into sand-box following by water rain. The experiment was able to obtain information about contaminant distribution and biodegradation in the subsurface. Besides combining measurements from multiple geophysical and/or hydrochemical measurements allow us to obtain more accurate characterization of spatial variability. The work is part of the research project ModelPROBE (Model-Driven soil probing, site assessment and evaluation, Grant No. 213161 in the framework of the EC-FP7 funded).

Giampaolo, Valeria; Rizzo, Enzo; Straface, Salvatore; Votta, Mario; Lapenna, Vincenzo

2010-05-01

38

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

39

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

40

Three-dimensional geologic modeling to determine the spatial attributes of hydrocarbon contamination, Noval Facility Fuel Farm, El Centro, California  

Microsoft Academic Search

An investigation was conducted at the Naval Air Facility located in El Centro (NAFEC), to determine the vertical and horizontal extent of hydrocarbon contamination at the facilities fuel farm. The fuel products are the result of tank and pipeline leakage, past tank cleaning, and past disposal of fuel dispensing and filter cleaning practices. Subsurface soil and groundwater data was collected

C. Johnson; S. Mutch; D. Padgett; L. Roche

1994-01-01

41

Armored Enzyme Nanoparticles for Remediation of Subsurface Contaminants  

SciTech Connect

The remediation of subsurface contaminants is a critical problem for the Department of Energy, other government agencies, and our nation. Severe contamination of soil and groundwater exists at several DOE sites due to various methods of intentional and unintentional release. Given the difficulties involved in conventional removal or separation processes, it is vital to develop methods to transform contaminants and contaminated earth/water to reduce risks to human health and the environment. Transformation of the contaminants themselves may involve conversion to other immobile species that do not migrate into well water or surface waters, as is proposed for metals and radionuclides; or degradation to harmless molecules, as is desired for organic contaminants. Transformation of contaminated earth (as opposed to the contaminants themselves) may entail reductions in volume or release of bound contaminants for remediation. Research at Rensselaer focused on the development of haloalkane dehalogenase as a critical enzyme in the dehalogenation of contaminated materials (ultimately trichloroethylene and related pollutants). A combination of bioinformatic investigation and experimental work was performed. The bioinformatics was focused on identifying a range of dehalogenase enzymes that could be obtained from the known proteomes of major microorganisms. This work identified several candidate enzymes that could be obtained through relatively straightforward gene cloning and expression approaches. The experimental work focused on the isolation of haloalkane dehalogenase from a Xanthobacter species followed by incorporating the enzyme into silicates to form biocatalytic silicates. These are the precursors of SENs. At the conclusion of the study, dehalogenase was incorporated into SENs, although the loading was low. This work supported a single Ph.D. student (Ms. Philippa Reeder) for two years. The project ended prior to her being able to perform substantive bioinformatics efforts that would identify more promising dehalogenase enzymes. The SEN synthesis, however, was demonstrated to be partially successful with dehalogenases. Further work would provide optimized dehalogenases in SENs for use in pollution remission.

Jonathan S. Dordick; Jay Grate; Jungbae Kim

2007-02-19

42

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

43

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

44

Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site  

Microsoft Academic Search

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,

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

2010-01-01

45

Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration  

E-print Network

Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration Philip C. Myint, Laurence Rongy, Kjetil B. Haugen, Abbas Firoozabadi Department. Combustion of fossil fuels contributes to rising atmospheric carbon dioxide (CO2) levels that have been

Firoozabadi, Abbas

46

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

47

Brines as Sources of Long-term Subsurface Contamination  

NASA Astrophysics Data System (ADS)

Concentrated salt solutions, i.e. brines, are source terms for environmental contaminants released into surface waters and groundwaters. Brines arise from both natural and industrial processes such as natural salt deposits, solid rocket fuel production, landfill leachates, nuclear fuel reprocessing, and acid rock drainage. Additionally, many of the in-situ remediation fluids that have been implemented at the pilot or the field scale are also classified as brines. While brines are miscible with water, mixing processes are slow in the subsurface and this constrains the dilution of contaminants present within brines and the delivery of remediation fluids to sites where reactions are needed. The mixing of brines during their vertical migration through aquifers is determined by aquifer permeability as well as differences in density and viscosity between the brine and the ambient groundwater. The stability criterion for brine displacement was predicted in 1952 by Hill and the resulting dispersion at the mixing front is quantified by a compilation of literature data and the acquisition of new experimental data. As brines sink through aquifers, they become emplaced in less accessible locations where mass transfer models predict that contaminants within brines are slowly released into flowing groundwater. For radioactive wastes and environmental contaminants with very low acceptable concentrations, groundwater quality can be impacted for decades. Field data from a cooling water disposal site suggest that a dense brine is likely still present as a source term 40 years after waste disposal was stopped. Overall, analysis of pollution sources, quantification of transport processes, generalization of laboratory data, and limited evaluation of field data indicate that brines represent long-term sources of groundwater contamination and that source control has not been seriously addressed.

Flowers, T. C.; Hunt, J. R.

2004-12-01

48

DEVELOPMENT OF A DATA EVALUATION/DECISION SUPPORT SYSTEM FOR REMEDIATION OF SUBSURFACE CONTAMINATION  

EPA Science Inventory

Subsurface contamination frequently originates from spatially distributed sources of multi-component nonaqueous phase liquids (NAPLs). Such chemicals are typically persistent sources of ground-water contamination that are difficult to characterize. This work addresses the feasi...

49

INTERNET COURSE ON MODELING SUBSURFACE TRANSPORT OF PETROLEUM HYDROCARBONS  

EPA Science Inventory

Assessment of leaks from underground storage tanks relies on knowledge of contaminant fate and transport, hydrology and in some cases modeling. EPA is developing an interactive, on-line training course to provide states with a low-cost training opportunity for these areas. Two ...

50

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

51

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

52

Bacterial and archaeal communities in long-term contaminated surface and subsurface soil evaluated through coextracted RNA and DNA.  

PubMed

Soil RNA and DNA were coextracted along a contamination gradient at a landfarming field with aged crude oil contamination to investigate pollution-dependent differences in 16S rRNA and rRNA gene pools. Microbial biomass correlated with nucleic acid yields as well as bacterial community change, indicating that the same factors controlled community size and structure. In surface soil, bacterial community evenness, estimated through length heterogeneity PCR (LH-PCR) fingerprinting, appeared higher for RNA-based than for DNA-based communities. The RNA-based community profiles resembled the DNA-based communities of soil with a lower contamination level. Cloning-based identification of bacterial hydrocarbon-degrading taxa in the RNA pool, representing the viable community with high protein synthesis potential, indicated that decontamination processes still continue. Analyses of archaea revealed that only Thaumarchaeota were present in the aerobic samples, whereas more diverse communities were found in the compacted subsurface soil with more crude oil. For subsurface bacteria, hydrocarbon concentration explained neither the community structure nor the difference between RNA-based and DNA-based communities. However, rRNA of bacterial taxa associated with syntrophic and sulphate-reducing alkane degradation was detected. Although the same prokaryotic taxa were identified in DNA and RNA, comparison of the two nucleic acid pools can aid in the assessment of past and future restoration success. PMID:24986450

Mikkonen, Anu; Santalahti, Minna; Lappi, Kaisa; Pulkkinen, Anni-Mari; Montonen, Leone; Suominen, Leena

2014-10-01

53

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

54

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

55

Observed relation of soil magnetic susceptibility and soil gas hydrocarbon analyses to subsurface hydrocarbon accumulations  

Microsoft Academic Search

Magnetic susceptibility (MS) studies on soils over 19 oil and gas fields showed anomalously large amounts of diagenetic minerals in shallow-depth samples in about 98% of the cases tested. Soil MS anomalies were compared with soil gas hydrocarbon (GHC) anomalies over 12 oil and gas fields (including several stratigraphic traps) and one gas storage reservoir. Samples were collected along the

D. F. Saunders; K. R. Burson; C. K. Thompson

1991-01-01

56

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

DOEpatents

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

Knauss, Kevin G. (Livermore, CA); Copenhaver, Sally C. (Livermore, CA); Aines, Roger D. (Livermore, CA)

2000-01-01

57

Method 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.

1995-10-03

58

Petroleum-related hydrocarbons in deep and subsurface sediments from South-Western Barents Sea.  

PubMed

Subsurface sediments from a pockmark area in South-Western Barents Sea have been earlier found to contain elevated levels of petroleum-related polycyclic aromatic hydrocarbons. This work describes a comprehensive analysis of various biomarkers, including the highly source-specific hopanes, in a 4.5 m long gravity core from the same area, together with subsurface sediment samples from other areas in the region without pockmarks present ("background samples"). A clear difference between the pockmark gravity core and the background sediment cores was found, both with regard to genesis and the level of transformation of organic matter. A number of indicator parameters, such as methylphenanthrene index (MPI-1), point towards a significantly higher maturity of hydrocarbons in the pockmark core throughout its length as compared to the other sampled locations. Higher contents of microbial hopanoids (hopenes) may indicate the former presence of petroleum. These findings confirm the hypothesis of a natural hydrocarbon source in the deeper strata present in the studied location with pockmarks. PMID:21601919

Boitsov, Stepan; Petrova, Vera; Jensen, Henning K B; Kursheva, Anna; Litvinenko, Ivan; Chen, Yifeng; Klungsøyr, Jarle

2011-06-01

59

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

60

Biogeochemical Stability of Contaminants in the Subsurface Following In Situ Treatment  

EPA Science Inventory

In recent years, innovative treatment technologies have emerged to meet groundwater cleanup goals. In many cases these methods take advantage of the redox behavior of contaminant species. For example, remedial technologies that strategically manipulate subsurface redox conditio...

61

MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE: APPLICATIONS: JOURNAL ARTICLE  

EPA Science Inventory

NRMRL-ADA-00329 Azadpour-Keeley**, A., Keeley, J.W., Russell, H.H., and Sewell*, G.W. Monitored Natural Attenuation of Contaminants in the Subsurface: Applications. Ground Water Monitoring and Reme...

62

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. PMID:20870785

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

2010-01-01

63

The use of biological activities to monitor the removal of fuel contaminants—perspective for monitoring hydrocarbon contamination: a review  

Microsoft Academic Search

Soil biological activities are vital for the restoration of soil contaminated with hydrocarbons. Their role includes the biotransformation of petroleum compounds into harmless compounds. In this paper, the use of biological activities as potential monitoring tools or bioindicators during bioremediation of hydrocarbon-contaminated soil are reviewed. The use of biological activities as bioindicators of hydrocarbon removal in soil has been reported

Mphekgo P. Maila; Thomas E. Cloete

2005-01-01

64

Polycyclic Aromatic Hydrocarbon Distribution and Modification in the Sub-surface Plume Near the Deepwater Horizon Wellhead  

NASA Astrophysics Data System (ADS)

A significant concern associated with oil spills is the toxicity associated with the polycyclic aromatic hydrocarbon (PAH) component. Ratios of various PAH's have also been used as indicators of oil sources. During a late May/early June cruise, 57 samples for PAH analysis were collected in the vicinity of the Deepwater Horizon wellhead. Most samples were from the previously reported sub-surface oil plume, centered near 1100 m depth. PAH concentrations ranged up to 117 ?g/L and rapidly diminished in the subsurface with distance from the wellhead. The Macondo well oil was observed to be rich in naphthalenes. Within a few km of the wellhead, the percentage of methyl-naphthalenes in the sub-surface plume was generally higher than in the source, suggesting preferential solubilization of this low molecular weight fraction. However, the percentage rapidly decreased away from the well also suggesting rapid destruction or removal of the naphthalenes. The pyrogenic index (Wang et al.) was <0.05 for all samples, indicating a petroleum origin. For a few samples, some other PAH ratios (e.g., MP/P and P/A ratios) suggested a combustion origin. However, these ratios also tended to vary both with percent methyl-naphthalenes and distance from the wellhead, suggesting anomalous ratios originating from solubilization/degradation effects. We also obtained a more limited set of surface water samples, generally avoiding the most contaminated areas as well as areas of oil burning. For these surface water samples, similar trends were observed as at depth, probably resulting from selective volatilization and photo-degradation. Overall, the data illustrate how environmental factors lead both to reduced concentrations and fractionation of the PAH's.

Shiller, A. M.; Joung, D.; Wade, T.

2011-12-01

65

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

66

Novel method for cleaning a vacuum chamber from hydrocarbon contamination  

SciTech Connect

A novel method for cleaning a high vacuum chamber is presented. This method is based on concurrent in situ high-energetic UV light activation of contaminants located in the residual gas and at the vacuum chamber surfaces as well as the in situ generation of highly reactive ozone. Ozone oxidizes the contaminants to volatile species. Investigations by energy-dispersive x-ray analysis of residual gas depositions and mass-spectroscopy measurements of the residual gas in the vacuum chamber identify the contaminant species as hydrocarbons. After a cleaning period of 8 h, a decrease in measured chamber contamination by about 90% could be achieved according to atomic force microscope analysis. Mass spectroscopy measurements using a residual gas analyzer indicate the creation of volatile, carbonaceous species during the cleaning process.

Wanzenboeck, H. D.; Roediger, P.; Hochleitner, G.; Bertagnolli, E.; Buehler, W. [Vienna University of Technology, Floragasse 7/1, A-1040 Vienna (Austria); Carl Zeiss NTS GmbH, Carl-Zeiss-Str. 56, Oberkochen 73447 (Germany)

2010-11-15

67

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

68

Release of polyaromatic hydrocarbons from coal tar contaminated soils  

SciTech Connect

A variety of process wastes generated from manufactured gas production (MGP) have contaminated soils and groundwater at production and disposal sites. Coal tar, consisting of a complex mixture of hydrocarbons present as a nonaqueous phase liquid, makes up a large portion of MGP wastes. Of the compounds in coal tar, polyaromatic hydrocarbons (PAHs) are the major constituents of environmental concern due to their potential mutagenic and carcinogenic hazards. Characterization of the release of PAHs from the waste-soil matrix is essential to quantifying long-term environmental impacts in soils and groundwater. Currently, conservative estimates for the release of PAHs to the groundwater are made assuming equilibrium conditions and using relationships derived from artificially contaminated soils. Preliminary work suggests that aged coal tar contaminated soils have much lower rates of desorption and a greater affinity for retaining organic contaminants. To obtain better estimates of desorption rates, the release of PAHs from a coal tar soil was investigated using a flow-interruption, miscible displacement technique. Methanol/water solutions were employed to enhance PAH concentrations above limits of detection. For each methanol/water solution employed, a series of flow interrupts of varying times was invoked. Release rates from each methanol/water solution were estimated from the increase in concentration with duration of flow interruption. Aqueous-phase release rates were then estimated by extrapolation using a log-linear cosolvency model.

Priddy, N.D.; Lee, L.S. [Purdue Univ., West Lafayette, IN (United States). Dept. of Agronomy

1996-11-01

69

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

70

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

1996-12-31

71

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

72

Utilization of petroleum hydrocarbons by Pseudomonas fluorescens isolated from a petroleum-contaminated soil  

Microsoft Academic Search

A strain of Pseudomonas fluorescens, isolated from petroleum hydrocarbon-contaminated soil was examined for its ability to utilize a variety of hydrocarbon substrates. Surface tension measurements indicated the production of biosurfactant during the microbial degradation of hydrocarbon. The organism utilized both short and long chain n-alkanes. It emulsified a number of aliphatic and aromatic hydrocarbons.

S Barathi; N Vasudevan

2001-01-01

73

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

74

Geophysical investigation of anomalous conductivity at a hydrocarbon contaminated site  

SciTech Connect

The intuitive geoelectric model for hydrocarbon light non-aqueous phase liquid (LNAPL) plumes treats the plume as a resistive body in the subsurface. Results of field studies have shown that plume bodies can develop conductive attributes over time, and that this dichotomous nature of electrical conductivity varies over time. A comprehensive geophysical survey was undertaken to evaluate the electrical nature of an older plume as well as to evaluate the methods best suited for characterization. Dipole-dipole resistivity profiling, self potential, electromagnetic induction, and ground penetrating radar were all used to characterize the conductive plume. Ground penetrating radar located conductive plume boundaries best, while the dipole-dipole resistivity and self potential methods located the plume but did not resolve the boundaries of the plume.

Nash, M.S.; Atekwana, E.; Sauck, W.A. [Western Michigan Univ., Kalamazoo, MI (United States)

1997-10-01

75

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

76

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. PMID:22053187

Seuront, Laurent

2011-01-01

77

FIELD-DRIVEN APPROACHES TO SUBSURFACE CONTAMINANT TRANSPORT MODELING.  

EPA Science Inventory

Observations from field sites provide a means for prioritizing research activities. In the case of petroleum releases, observations may include spiking of concentration distributions that may be related to water table fluctuation, co-location of contaminant plumes with geochemi...

78

USE OF APATITE FOR CHEMICAL STABILIZATION OF SUBSURFACE CONTAMINANTS  

Microsoft Academic Search

Groundwater at many Federal and civilian industrial sites is often contaminated with toxic metals at levels that present a potential concern to regulatory agencies. The U.S. Department of Energy (DOE) has some unique problems associated with radionuclides (primarily uranium), but metal contaminants most likely drive risk-based cleanup decisions, from the perspective of human health, in groundwater at DOE and U.S.

William D. Bostick

2003-01-01

79

Effects of Surfactant Sorption on the Equilibrium Distribution of Organic Pollutants in Contaminated Subsurface Environments  

Microsoft Academic Search

Partitioning of two hydrophobic organic contaminants (HOCs), phenanthrene and naphthalene, to surfactant micelles, kaolinite\\u000a and sorbed surfactants was studied to provide further insight on (1) the effectiveness of using sorbed surfactants to remove\\u000a HOCs from water and (2) the feasibility of using surfactant-enhanced aquifer remediation (SEAR) for contaminated subsurface\\u000a systems. Sorbed surfactant partition coefficients (Kss) showed a strong dependence on

Seok-Oh Ko; Mark A. Schlautman; Elizabeth R. Carraway

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

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

82

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

83

Control of Subsurface Contaminant Migration by Vertical Engineered Barriers  

EPA Science Inventory

This Fact Sheet is intended to provide remedial project managers (RPMs), on-scene coordinators (OSCs), contractors, and other remediation stakeholders with a basic overview of hazardous waste containment systems constructed to prevent or limit the migration of contamination in gr...

84

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 (Department of Energy) DOE weapons production sites. Many of the chlorinated hydrocarbons are either known or suspected carcinogens and thus pose health risks to the public and/or site workers. Chlorinated hydrocarbons, unlike simple hydrocarbons, 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 the literature, and disagreement still exist about the mechanisms and rates of many of the key reactions.

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

2002-08-01

85

Monitoring Contamination of the subsurface with Quasi-Static Deformation  

NASA Astrophysics Data System (ADS)

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 one tiltmeter at the bottom of a 10m cased borehole and one seismometer buried to a depth of about 1m. The instruments were installed in late summer and early fall of 2002. The drift in tilt caused by their installation decayed to near background levels in about one year. The site was irrigated with plain water at 50,000 l/day for 40 days during the fall of 2003. The irrigation was repeated in the fall of 2004 for 50 days, again with 50,000 l/day. This time the irrigation water contained 150ppm of a biosurfactant. This surfactant was chosen to simulate a contaminant through its effect on the modification of surface tension and because it is environmentally benign. It was developed for bioremediation. We expected subtle changes in the relative responses of the instruments as the elastic properties of the vadose zone were altered by the contaminant. This expectation is based on a long series of laboratory measurements, e.g. W. Brunner and H.A. Spetzler 2002. We used natural sources for the excitation of the instruments, solid Earth tides for the tiltmeters and microseisms, i.e. ocean generated noise at about 6s periods, for the seismometers. In the case of the tilt meters we used theoretical site specific tilt and compared that with our measured tilt. We found no significant change in the correlation coefficient between theoretical and measured tilt for the water-only irrigation. The correlation coefficient was generally above 0.9. The correlation coefficient dropped precipitously about ten days after we had started irrigating with the surfactant. It recovered again about ten days after irrigation was stopped. A preliminary analysis of the seismic data shows similar trends, but with much more noise. Using a Born approximation we calculate that a slight perturbation of the complex moduli near the surface does indeed yield changes in tidally-induced tilt near the observed values. Brunner, W. M. and H. A. Spetzler, Contaminant-Induced Mechanical Damping in Partially Saturated Berea Sandstone, Geophys. Res. Lett., Vol.29, No.16, 10.1029/2002GL015455 ,2002

Spetzler, H.; Snieder, R.; Zhang, J.

2005-12-01

86

In situ biodegradation of a hydrocarbon-contaminated landfill  

SciTech Connect

The anaerobic and/or low-aeration biodegradation of urban waste, contaminated by polycyclic aromatic hydrocarbon (PAH) compounds and a spill of tar products, is described. Before the industrial plant was designed, laboratory tests were carried out to determine the process feasibility and define the biodegradation rate of the pollutants. Preliminary tests on bacteria growth efficiency in aerobic and anaerobic conditions were carried out in Erlenmeyer flasks and showed interesting results in both cases. Following these tests, four different laboratory reactors were assembled to simulate waste treatment under different operating conditions. During 3 months of continuous treatment, the tar and PAH contents were measured in the waste and in the leachate and the bacteria population growth was registered. Treatment results show pollutant degradation of nearly 90%.

Arazzini, S.; Bocchieri, P.; Migliorini, G.; Rivara, L. [Castalia S.p.A., Genova (Italy); Tripaldi, G. [Castalia S.p.A., Roma (Italy)

1995-12-31

87

Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters.  

PubMed

The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well. PMID:24903252

Naseri, Masoud; Barabadi, Abbas; Barabady, Javad

2014-10-01

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

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

90

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

91

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

92

Rapid delineation of subsurface petroleum contamination using the site characterization and analysis penetrometer system  

Microsoft Academic Search

The Site Characterization and Analysis Penetrometer System (SCAPS) was used to investigate subsurface petroleum contamination\\u000a at Aberdeen Proving Ground, Maryland. The SCAPS is a rapid site-screening tool developed by the Tri-Services (U.S. Army, Navy,\\u000a and Air Force) to reduce the cost of installation restoration activities. The system, consisting of a geophysical cone penetrometer\\u000a fitted with a laser-induced fluorescence petroleum sensor,

W. M. Davis; E. R. Cespedes; L. T. Lee; J. F. Powell; R. A. Goodson

1997-01-01

93

RADIO FREQUENCY ENHANCED DECONTAMINATION OF SOILS CONTAMINATED WITH HALOGENATED HYDROCARBONS  

EPA Science Inventory

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

94

Integrated magnetic, gravity, and GPR surveys to locate the probable source of hydrocarbon contamination in Sharm El-Sheikh area, south Sinai, Egypt  

NASA Astrophysics Data System (ADS)

Sharm El-Sheikh waters were suddenly hit by hydrocarbon spills which created a serious threat to the prosperous tourism industry in and around the city. Analysis of soil samples, water samples, and seabed samples collected in and around the contaminated bay area showed anomalous levels of hydrocarbons. An integrated geophysical investigation, using magnetic, gravity, and ground penetrating radar geophysical tools, was conducted in the headland overlooking the contaminated bay in order to delineate the possible subsurface source of contamination. The results of the geophysical investigations revealed three underground manmade reinforced concrete tanks and a complicated network of buried steel pipes in addition to other unidentified buried objects. The depths and dimensions of the discovered objects were determined. Geophysical investigations also revealed the presence of a north-south oblique slip fault running through the eastern part of the studied area. Excavations, conducted later on, confirmed the presence of one of the tanks delineated by the geophysical surveys.

Morsy, Mona; Rashed, Mohamed

2013-01-01

95

Polar non-hydrocarbon contaminants in reservoir core extracts  

Microsoft Academic Search

: A geochemical investigation of oils in sandstone core plugs and drill stem test oils was carried out on samples from a North Sea reservoir. A sample of diesel used as a constituent of the drilling fluids was also analysed. The aliphatic and aromatic hydrocarbons and polar non-hydrocarbons were isolated using solid phase extraction methods. GC analysis of the hydrocarbon

B. Bennett; S. R. Larter

2000-01-01

96

Ecotoxicity of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil.  

PubMed

Soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (PAHs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. The total concentration of the 16 PAHs listed as priority pollutants by the US Environmental Protection Agency (US-EPA) was 2634+/-241 mg/kgdw in soil samples. The toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (Vibrio fischeri; Microtox test, Daphnia magna) and chronic (Pseudokirchneriella subcapitata, Ceriodaphnia dubia) bioassays and the EC values were expressed as percentage water extract in the test media (v/v). Algal growth (EC50-3d=2.4+/-0.2% of the water extracts) and reproduction of C. dubia (EC50-7d=4.3+/-0.6%) were the most severely affected, compared to bacterial luminescence (EC50-30 min=12+/-3%) and daphnid viability (EC50-48 h=30+/-3%). The Ames and Mutatox tests indicated mutagenicity of water extracts, while no response was found with the umu test. The toxicity of the soil samples was assessed on the survival and reproduction of earthworms (Eisenia fetida) and collembolae (Folsomia candida), and on the germination and growth of higher plants (Lactuca sativa L.: lettuce and Brassica chinensis J.: Chinese cabbage). The EC50 values were expressed as percentage contaminated soil in ISO soil test medium (weight per weight-w/w) and indicated severe effects on reproduction of the collembola F. candida (EC50-28 d=5.7%) and the earthworm E. fetida (EC50-28 d=18% and EC50-56 d=8%, based on cocoon and juvenile production, respectively). Survival of collembolae was already affected at a low concentration of the contaminated soil (EC50-28 d=11%). The viability of juvenile earthworms was inhibited at much lower concentrations of the cokery soil (EC50-14 d=28%) than the viability of adults (EC50-14 d=74%). Only plant growth was inhibited (EC50-17d=26%) while germination was not. Chemical analyses of water extracts allowed us to identify inorganic water-extractable pollutants as responsible for toxicity on aquatic species, especially copper for effects on D. magna and C. dubia. The soil toxicity on collembolae and earthworms could be explained by 4 PAH congeners-fluorene, phenanthrene, pyrene, and fluoranthene. Yet, toxicity of the cokery soil as a whole was much lower than toxicity that could be deduced from the concentration of each congener in spiked soils, indicating that pollutants in the soil became less bioavailable with ageing. PMID:17382389

Eom, I C; Rast, C; Veber, A M; Vasseur, P

2007-06-01

97

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...

98

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

99

Effectiveness of in site biodegradation for the remediation of polycyclic aromatic hydrocarbons at a contaminated oil refinery, Port Arthur, Texas  

E-print Network

The effectiveness of bioremediation for the removal of polycyclic aromatic hydrocarbons (PAHs) from sediments contaminated with highly weathered petroleum was evaluated at a contaminated oil refinery. The sediments were chronically contaminated...

Moffit, Alfred Edward

2012-06-07

100

Microbial Community Responses to Organophosphate Substrate Additions in Contaminated Subsurface Sediments  

PubMed Central

Background Radionuclide- and heavy metal-contaminated subsurface sediments remain a legacy of Cold War nuclear weapons research and recent nuclear power plant failures. Within such contaminated sediments, remediation activities are necessary to mitigate groundwater contamination. A promising approach makes use of extant microbial communities capable of hydrolyzing organophosphate substrates to promote mineralization of soluble contaminants within deep subsurface environments. Methodology/Principal Findings Uranium-contaminated sediments from the U.S. Department of Energy Oak Ridge Field Research Center (ORFRC) Area 2 site were used in slurry experiments to identify microbial communities involved in hydrolysis of 10 mM organophosphate amendments [i.e., glycerol-2-phosphate (G2P) or glycerol-3-phosphate (G3P)] in synthetic groundwater at pH 5.5 and pH 6.8. Following 36 day (G2P) and 20 day (G3P) amended treatments, maximum phosphate (PO43?) concentrations of 4.8 mM and 8.9 mM were measured, respectively. Use of the PhyloChip 16S rRNA microarray identified 2,120 archaeal and bacterial taxa representing 46 phyla, 66 classes, 110 orders, and 186 families among all treatments. Measures of archaeal and bacterial richness were lowest under G2P (pH 5.5) treatments and greatest with G3P (pH 6.8) treatments. Members of the phyla Crenarchaeota, Euryarchaeota, Bacteroidetes, and Proteobacteria demonstrated the greatest enrichment in response to organophosphate amendments and the OTUs that increased in relative abundance by 2-fold or greater accounted for 9%–50% and 3%–17% of total detected Archaea and Bacteria, respectively. Conclusions/Significance This work provided a characterization of the distinct ORFRC subsurface microbial communities that contributed to increased concentrations of extracellular phosphate via hydrolysis of organophosphate substrate amendments. Within subsurface environments that are not ideal for reductive precipitation of uranium, strategies that harness microbial phosphate metabolism to promote uranium phosphate precipitation could offer an alternative approach for in situ sequestration. PMID:24950228

Martinez, Robert J.; Wu, Cindy H.; Beazley, Melanie J.; Andersen, Gary L.; Conrad, Mark E.; Hazen, Terry C.; Taillefert, Martial; Sobecky, Patricia A.

2014-01-01

101

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

102

Plant aided biopile for remediation of soil contaminated by petroleum hydrocarbons  

Microsoft Academic Search

As a more innovative technique, plant aided biopile has been developed to enhance the remediation efficiency of biopile, known as one of the remediation methods for soil contaminated by petroleum hydrocarbons. Plant effects were added to the conventional biopile and its potential application was tested by comparing remediation efficiency at artificially diesel contaminated soil. The treatments were a biopile treatment,

Y. Chang; K. Kim; K. Sung; C. Lee

2003-01-01

103

A street deposit sampling method for metal and hydrocarbon contamination assessment  

Microsoft Academic Search

Urban surface contamination, by atmospheric deposits as well as human activities, is a major concern for urban pollution management. Besides coarse street deposits which are clearly perceived and easily removed, suspended solid (SS) surface loads and contamination by heavy metals and hydrocarbons are rarely assessed although they could be of major importance with regards to combined or separate server overflow

François-Jérôme Bris; Stéphane Garnaud; Nicole Apperry; Ana Gonzalez; Jean-Marie Mouchel; Ghassan Chebbo; Daniel R Thévenot

1999-01-01

104

Identification of Sediment Organic Carbon Location and Association with Polycyclic Aromatic Hydrocarbons (PAHs) in Contaminated Sediment  

E-print Network

Hydrocarbons (PAHs) in Contaminated Sediment Upal Ghosh1 , Richard G. Luthy1 , J. Seb Gillette2 , and Richard N is known about the mechanisms of PAH and other hydrophobic organic compound sequestration and aging successful sediment bioremediation is the availability of contaminants to microorganisms for degradation

105

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

106

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

SciTech Connect

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. Phytoremediation and Phytostabilization have been proven to be a cost-effective, safe, efficient, and publicly acceptable technology for clean up and/or stabilization of contaminant metals . However, no phyto-based technologies have been developed for stabilization or removal of plutonium from soils and groundwater, and very few have been investigated for other actinides . Current metal-phytostabilization and phytoremediation techniques, predominately based around lead, nickel, and other soft-metal phytoextraction, will almost certainly be inadequate for plutonium due its distinct chemical properties . Phytosiderophore-based phytoremediation may provide technically and financially practical methods for remediation and long-term stewardship of soils that have low to moderate, near surface actinide contamination . We plan to demonstrate potential benefits of phytosiderophore-producing plants for long-term actinide contaminant stabilization by the plant's prevention of soil erosion and actinide migration through hydraulic control and/or through actinide removal through phytoextraction . We may also show possible harm caused by these plants through increased presence of actinide chelators that could increase actinide mobilization and migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or be used to develop plant-based soil stabilization/remediation technologies .

Ruggiero, C. E. (Christy E.); Twary, S. N. (Scott N.); Deladurantaye, E. (Elise)

2003-01-01

107

Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site  

SciTech Connect

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 ribosomal RNA 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 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 concentration of nitrogen species, oxygen and sampling season did not appear to strongly influence the distribution of Rhodanobacter. 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 [Florida State University; Prakash, Om [Florida State University; Jasrotia, Puja [Florida State University; Overholt, Will [Florida State University; Cardenas, Erick [Michigan State University, East Lansing; Hubbard, Daniela [Florida State University; Tiedje, James M. [Michigan State University, East Lansing; Watson, David B [ORNL; Schadt, Christopher Warren [ORNL; Brooks, Scott C [ORNL; Kostka, Joel [Florida State University

2011-01-01

108

Plant-bacteria partnerships for the remediation of hydrocarbon contaminated soils.  

PubMed

Plant-bacteria partnerships have been extensively studied and applied to improve crop yield. In addition to their application in agriculture, a promising field to exploit plant-bacteria partnerships is the remediation of soil and water polluted with hydrocarbons. Application of effective plant-bacteria partnerships for the remediation of hydrocarbons depend mainly on the presence and metabolic activities of plant associated rhizo- and endophytic bacteria possessing specific genes required for the degradation of hydrocarbon pollutants. Plants and their associated bacteria interact with each other whereby plant supplies the bacteria with a special carbon source that stimulates the bacteria to degrade organic contaminants in the soil. In return, plant associated-bacteria can support their host plant to overcome contaminated-induced stress responses, and improve plant growth and development. In addition, plants further get benefits from their associated-bacteria possessing hydrocarbon-degradation potential, leading to enhanced hydrocarbon mineralization and lowering of both phytotoxicity and evapotranspiration of volatile hydrocarbons. A better understanding of plant-bacteria partnerships could be exploited to enhance the remediation of hydrocarbon contaminated soils in conjunction with sustainable production of non-food crops for biomass and biofuel production. PMID:23058201

Khan, Sumia; Afzal, Muhammad; Iqbal, Samina; Khan, Qaiser M

2013-01-01

109

Field study of in situ remediation of petroleum hydrocarbon contaminated soil on site using microwave energy.  

PubMed

Many laboratory-scale studies strongly suggested that remediation of petroleum hydrocarbon contaminated soil by microwave heating is very effective; however, little definitive field data existed to support the laboratory-scale observations. This study aimed to evaluate the performance of a field-scale microwave heating system to remediate petroleum hydrocarbon contaminated soil. A constant microwave power of 2 kW was installed directly in the contaminated area that applied in the decontamination process for 3.5h without water input. The C10-C40 hydrocarbons were destroyed, desorbed or co-evaporated with moisture from soil by microwave heating. The moisture may play an important role in the absorption of microwave and in the distribution of heat. The success of this study paved the way for the second and much larger field test in the remediation of petroleum hydrocarbon contaminated soil by microwave heating in place. Implemented in its full configuration for the first time at a real site, the microwave heating has demonstrated its robustness and cost-effectiveness in cleaning up petroleum hydrocarbon contaminated soil in place. Economically, the concept of the microwave energy supply to the soil would be a network of independent antennas which powered by an individual low power microwave generator. A microwave heating system with low power generators shows very flexible, low cost and imposes no restrictions on the number and arrangement of the antennas. PMID:22119305

Chien, Yi-Chi

2012-01-15

110

Ecotoxicity Monitoring of Hydrocarbon-Contaminated Soil During Bioremediation: A Case Study  

Microsoft Academic Search

The ecotoxicity of hydrocarbon-contaminated soil originating from a brownfield site was evaluated during a 17-month biodegradation\\u000a pilot test. The initial concentration of total petroleum hydrocarbons (TPHs) in the soil was 6380 ?g\\/g dry weight. An amount\\u000a of 200 kg soil was inoculated with 1.5 L of the bacterial preparation GEM-100 containing Pseudomonas sp. and Acinetobacter sp. strains (5.3 1010 CFU.mL?1) adapted

TomᚠHubálek; Simona Vosáhlová; Vít Mat?j?; Nora Ková?ová; ?en?k Novotný

2007-01-01

111

Influence of nutrients addition and bioaugmentation on the hydrocarbon biodegradation of a chronically contaminated Antarctic soil.  

PubMed

Complexity involved in the transport of soils and the restrictive legislation for the area makes on-site bioremediation the strategy of choice to reduce hydrocarbons contamination in Antarctica. The effect of biostimulation (with N and P) and bioaugmentation (with two bacterial consortia and a mix of bacterial strains) was analysed by using microcosms set up on metal trays containing 2.5 kg of contaminated soil from Marambio Station. At the end of the assay (45 days), all biostimulated systems showed significant increases in total heterotrophic aerobic and hydrocarbon-degrading bacterial counts. However, no differences were detected between bioaugmented and nonbioaugmented systems, except for J13 system which seemed to exert a negative effect on the natural bacterial flora. Hydrocarbons removal efficiencies agreed with changes in bacterial counts reaching 86 and 81% in M10 (bioaugmented) and CC (biostimulated only) systems. Results confirmed the feasibility of the application of bioremediation strategies to reduce hydrocarbon contamination in Antarctic soils and showed that, when soils are chronically contaminated, biostimulation is the best option. Bioaugmentation with hydrocarbon-degrading bacteria at numbers comparable to the total heterotrophic aerobic counts showed by the natural microflora did not improve the process and showed that they would turn the procedure unnecessarily more complex. PMID:19191978

Ruberto, L; Dias, R; Lo Balbo, A; Vazquez, S C; Hernandez, E A; Mac Cormack, W P

2009-04-01

112

Biodegradation of petroleum hydrocarbons in contaminated aqueous and sediment environments  

E-print Network

, respectively), a polyoxyethylene, or both positive and negative charges (defined as nonionic and amphoteric) (Figure 4). Typically, the hydrophobic tail is a fiexible-chain hydrocarbon where the longer the chain, the more effective the surfactant. However... Imidazolium salts Amphoteric Hydrophobic Nonionic Hydrophobic Betatines Sodium perflouro. cetyl carboxylates Alkylpherol ethxylates Ethylene-oxide-propylene-oxide (EO-PO) copolymers Alkanolamides tk ethoxylates Figure 4-Basic molecular structures...

Mills, Marc Allyn

2012-06-07

113

Potential of phytoremediation for the removal of petroleum hydrocarbons in contaminated salt marsh sediments.  

PubMed

Degradation of petroleum hydrocarbons in colonized and un-colonized sediments by salt marsh plants Juncus maritimus and Phragmites australis collected in a temperate estuary was investigated during a 5-month greenhouse experiment. The efficiency of two bioremediation treatments namely biostimulation (BS) by the addition of nutrients, and bioaugmentation (BA) by addition of indigenous microorganisms was tested in comparison with hydrocarbon natural attenuation in un-colonized and with rhizoremediation in colonized sediments. Hydrocarbon degrading microorganisms and root biomass were assessed as well as hydrocarbon degradation levels. During the study, hydrocarbon degradation in un-colonized sediments was negligible regardless of treatments. Rhizoremediation proved to be an effective strategy for hydrocarbon removal, yielding high rates in most experiments. However, BS treatments showed a negative effect on the J. maritimus potential for hydrocarbon degradation by decreasing the root system development that lead to lower degradation rates. Although both plants and their associated microorganisms presented a potential for rhizoremediation of petroleum hydrocarbons in contaminated salt marsh sediments, results highlighted that nutrient requirements may be distinct among plant species, which should be accounted for when designing cleanup strategies. PMID:24584003

Ribeiro, Hugo; Mucha, Ana P; Almeida, C Marisa R; Bordalo, Adriano A

2014-05-01

114

Monitoring the bio-stimulation of hydrocarbon-contaminated soils by measurements of soil electrical properties, and CO2 content and its 13C/12C isotopic signature  

NASA Astrophysics Data System (ADS)

Hydrocarbon contaminated soils represent an environmental issue as it impacts on ecosystems and aquifers. Where significant subsurface heterogeneity exists, conventional intrusive investigations and groundwater sampling can be insufficient to obtain a robust monitoring of hydrocarbon contaminants, as the information they provide is restricted to vertical profiles at discrete locations, with no information between sampling points. In order to obtain wider information in space volume on subsurface modifications, complementary methods can be used like geophysics. Among geophysical methods, geoelectrical techniques such as electrical resistivity (ER) and induced polarization (IP) seem the more promising, especially to study the effects of biodegradation processes. Laboratory and field geoelectrical experiments to characterize soils contaminated by oil products have shown that mature hydrocarbon-contaminated soils are characterized by enhanced electrical conductivity although hydrocarbons are electrically resistive. This high bulk conductivity is due to bacterial impacts on geological media, resulting in changes in the chemical and physical properties and thus, to the geophysical properties of the ground. Moreover, microbial activity induced CO2 production and isotopic deviation of carbon. Indeed, produced CO2 will reflect the pollutant isotopic signature. Thus, the ratio ?13C(CO2) will come closer to ?13C(hydrocarbon). BIOPHY, project supported by the French National Research Agency (ANR), proposes to use electrical methods and gas analyses to develop an operational and non-destructive method for monitoring in situ biodegradation of hydrocarbons in order to optimize soil treatment. Demonstration field is located in the South of Paris (France), where liquid fuels (gasoline and diesel) leaked from some tanks in 1997. In order to stimulate biodegradation, a trench has been dug to supply oxygen to the water table and thus stimulate aerobic metabolic bioprocesses. ER and IP surveys are performed regularly to monitor the stimulated biodegradation and progress of remediation until soil cleanup. Microbial activity is characterized by CO2 production increase and ?13C isotopic deviation, in the produced CO2 measured by infrared laser spectroscopy, and by an evolution of electrical conductivity and IP responses in correlation with microbiological and chemical analyses.

Noel, C.; Gourry, J.; Ignatiadis, I.; Colombano, S.; Dictor, M.; Guimbaud, C.; Chartier, M.; Dumestre, A.; Dehez, S.; Naudet, V.

2013-12-01

115

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

116

Structure and Function of Microbial Communities Controlling the Fate and Transformation of U(VI) in Radionuclide Contaminated Subsurface Sediments  

Microsoft Academic Search

Uranium contamination is widespread in subsurface sediments at mining and milling sites across North America, South America, and Eastern Europe. In the U.S. alone, the Department of Energy (DOE) is responsible for the remediation of 7,280 km2 of soils and groundwater contaminated due to processes associated with uranium extraction for nuclear weapons production. As a result of waste disposal practices,

Denise Marie Akob

2008-01-01

117

Contamination of soil, soil gas, and ground water by hydrocarbon compounds near Greear, Morgan County, Kentucky. Water resources investigation  

Microsoft Academic Search

The purpose of the report is to present the results of an investigation of hydrocarbon contamination near Greear, KY. Specifically, the report describes the areal extent and migration of the hydrocarbon contamination in the soil, soil gas, and ground water in the study area. The report also includes a description of the hydrogeologic framework of the Greear area. The application

A. G. Alexander; D. D. Zettwoch; M. D. Unthank; R. B. Burns

1993-01-01

118

Emission of nitrous oxide from hydrocarbon contaminated soil amended with waste water sludge and earthworms  

Microsoft Academic Search

Soils in Mexico are often contaminated with hydrocarbons and addition of waste water sludge and earthworms accelerates their removal. However, little is known how contamination and subsequent bioremediation affects emissions of N2O and CO2. A laboratory study was done to investigate the effect of waste water sludge and the earthworm Eisenia fetida on emission of N2O and CO2 in a

Silvia M. Contreras-Ramos; Dioselina Álvarez-Bernal; Joaquín A. Montes-Molina; Oswald Van Cleemput; Luc Dendooven

2009-01-01

119

Occurrence and community composition of fast-growing Mycobacterium in soils contaminated with polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Fast-growing mycobacteria are considered essential members of the polycyclic aromatic hydrocarbons (PAH) degrading bacterial community in PAH-contaminated soils. To study the natural role and diversity of the Mycobacterium community in contaminated soils, a culture-independent fingerprinting method based on PCR combined with denaturing gradient gel electrophoresis (DGGE) was developed. New PCR primers were selected which specifically targeted the 16S rRNA genes

Natalie M. Leys; Annemie Ryngaert; Leen Bastiaens; Pierre Wattiau; Eva M. Top; Willy Verstraete; Dirk Springael

2005-01-01

120

Chromium transport in an acidic waste contaminated subsurface medium: the role of reduction.  

PubMed

A series of wet chemical extractions and column experiments, combined with electron microprobe analysis (EMPA) and X-ray photoelectron spectroscopy (XPS) measurements, were conducted to estimate the extent of Cr(VI) desorption and determine the mechanism(s) of Cr(VI) attenuation in contaminated and naturally aged (decades) Hanford sediments which were exposed to dichromate and acidic waste solutions. Results from wet extractions demonstrated that contaminated sediments contained a relatively large fraction of tightly-bound Cr. Results from column experiments showed that effluent Cr concentrations were low and only a small percentage of the total Cr inventory was removed from the sediments. EMPA inspections indicated that Cr contamination was spread throughout sediment matrix and high-concentrated Cr spots were absent. XPS analyses confirmed that most surface Cr occurred as reduced Cr(III), which was spatially associated with Fe(III). Collectively, the results from macroscopic experiments and microprobe and spectroscopic measurements demonstrated that reduction of Cr(VI) have occurred in these sediments, limiting dramatically the mass flux from this contaminated source. The most likely mechanism of Cr(VI) reduction is the acid promoted dissolution of Fe(II)-bearing soil minerals and/or their surface coatings, release of Fe(II) in the aqueous phase, abiotic homogeneous and/or heterogeneous Cr(VI) reduction by aqueous, sorbed and/or structural Fe(II), and subsequently, formation of insoluble Cr(III) phases or [Cr(III) Fe(III)] solid solutions. The results from this study will improve our fundamental understanding of Cr(VI) behavior in natural heterogeneous subsurface media and may be used as a basis for developing or selecting potential remedial measures. PMID:20875666

Qafoku, Nikolla P; Evan Dresel, P; Ilton, Eugene; McKinley, James P; Resch, Charles T

2010-12-01

121

Bioremediation of Hydrocarbons Contaminating Sewage Effluent Using Man-made Biofilms: Effects of Some Variables.  

PubMed

Biofilm samples were established on glass slides by submerging them in oil-free and oil-containing sewage effluent for a month. In batch cultures, such biofilms were effective in removing crude oil, pure n-hexadecane, and pure phenanthrene contaminating sewage effluent. The amounts of the removed hydrocarbons increased with increasing biofilm surface area exposed to the effluent. On the other hand, addition of the reducing agent thioglycollate dramatically inhibited the hydrocarbon bioremediation potential of the biofilms. The same biofilm samples removed contaminating hydrocarbons effectively in three successive batch bioremediation cycles but started to become less effective in the cycles thereafter, apparently due to mechanical biofilm loss during successive transfers. As major hydrocarbonoclastic bacteria, the biofilms harbored species belonging to the genera Pseudomonas, Microvirga, Zavarzinia, Mycobacterium, Microbacterium, Stenotrophomonas, Gordonia, Bosea, Sphingobium, Brachybacterium, and others. The nitrogen fixer Azospirillum brasilense and the microalga Ochromonas distigma were also present; they seemed to enrich the biofilms, with nitrogenous compounds and molecular oxygen, respectively, which are known to enhance microbiological hydrocarbon degradation. It was concluded that man-made biofilms based upon sewage microflora are promising tools for bioremediation of hydrocarbons contaminating sewage effluent. PMID:25146193

Al-Mailem, D M; Kansour, M K; Radwan, S S

2014-11-01

122

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...

123

Hydrocarbon solvent recovery in the presence of resin contaminants  

SciTech Connect

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. The system developed was a three-stage low temperature condensation process preceded by a cascade impactor. A scale model of the system was designed and constructed. It was tested in the laboratory, and on a split stream of an actual plant process.

Turpin, J.L.

1984-01-01

124

Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface  

Microsoft Academic Search

  Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC\\u000a were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene,\\u000a phenanthrene,

T Shi; Jim K. Fredrickson; David L. Balkwill

2001-01-01

125

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

Microsoft Academic Search

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.

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

2012-01-01

126

Study of Petroleum Hydrocarbons under Chemical-Biological Degradation in Contaminated Soils  

Microsoft Academic Search

Microbial decontamination of petroleum-polluted soils has been recognized to be an efficient, economical and versatile alternative for physical or chemical treatments. In this study, different components of petroleum in contaminated soil were investigated under optimal environmental conditions which were determined by previous experiments. An aerobic bacteria with the ability to utilize both hydrocarbons and benzene as carbon sources was identified

Ningning Sun; Hongqi Wang; Jingqi Liu; Yongqiang Qi

2009-01-01

127

Evaluation of landfarm remediation of hydrocarbon-contaminated soil at the inveresk railyard, Launceston, Australia  

Microsoft Academic Search

Costing of landfarm bioremediation of hydrocarbon-contaminated soil (2700 m3 material) at a disused railyard site in Tasmania, Australia is reported. The landfarm area (8000 m2) was enclosed in an impermeable clay embankment and where necessary the base was also rolled with clay. Microbial inoculation was not deemed to be necessary since suitable degrading biota were found to be present in

M. A. Line; C. D. Garland; M. Crowley

1996-01-01

128

EARLY WARNING MARINE WATER SUPPLY PROTECTION STRATEGY: THE THREAT OF OIL SPILL (PETROLEUM HYDROCARBON) CONTAMINATION  

EPA Science Inventory

Oil spills resulting from the twice-grounded freighter New Carissa on the Central Oregon coast in the spring of 1999 caused substantial concern regarding potential petroleum hydrocarbon (PHC) contamination of Coos Bay, Alsea Bay and Yaquina Bay estuaries and resident seawater fac...

129

Surfactants and Bacterial Bioremediation of Polycyclic Aromatic Hydrocarbon Contaminated Soil—Unlocking the Targets  

Microsoft Academic Search

The activities of man produce significant levels of toxic polycyclic aromatic hydrocarbon compounds (PAHs), which have been identified as excellent candidates for biodegradative removal from contaminated sites. PAHs strongly sorb to soil particles and can also partition into a nonaqueous phase, often limiting bioavailability. In this context, synthetic surfactants and biosurfactants will be discussed as a means to mobilize and

Roy Elliot; Naresh Singhal; Simon Swift

2010-01-01

130

Analysis of hydrocarbon-contaminated groundwater metagenomes as revealed by high-throughput sequencing.  

PubMed

The tendency for chlorinated aliphatics and aromatic hydrocarbons to accumulate in environments such as groundwater and sediments poses a serious environmental threat. In this study, the metabolic capacity of hydrocarbon (aromatics and chlorinated aliphatics)-contaminated groundwater in the KwaZulu-Natal province of South Africa has been elucidated for the first time by analysis of pyrosequencing data. The taxonomic data revealed that the metagenomes were dominated by the phylum Proteobacteria (mainly Betaproteobacteria). In addition, Flavobacteriales, Sphingobacteria, Burkholderiales, and Rhodocyclales were the predominant orders present in the individual metagenomes. These orders included microorganisms (Flavobacteria, Dechloromonas aromatica RCB, and Azoarcus) involved in the degradation of aromatic compounds and various other hydrocarbons that were present in the groundwater. Although the metabolic reconstruction of the metagenome represented composite cell networks, the information obtained was sufficient to address questions regarding the metabolic potential of the microbial communities and to correlate the data to the contamination profile of the groundwater. Genes involved in the degradation of benzene and benzoate, heavy metal-resistance mechanisms appeared to provide a survival strategy used by the microbial communities. Analysis of the pyrosequencing-derived data revealed that the metagenomes represent complex microbial communities that have adapted to the geochemical conditions of the groundwater as evidenced by the presence of key enzymes/genes conferring resistance to specific contaminants. Thus, pyrosequencing analysis of the metagenomes provided insights into the microbial activities in hydrocarbon-contaminated habitats. PMID:23307295

Abbai, Nathlee S; Pillay, Balakrishna

2013-07-01

131

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...

132

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...

133

Chlorinated hydrocarbon contaminants in feces of river otters from the southern Pacific  

E-print Network

hydrocarbon contaminants in coastal river otters (Lontra canadensis) were evaluated by sampling feces (scats.elsevier.com/locate/scitotenv #12;The North American river otter (Lontra canadensis) inhabits coastal regions of the Georgia Basin spatial trends in residues. © 2008 Elsevier B.V. All rights reserved. Keywords: River otter Lontra

134

Protozoa in Subsurface Sediments from Sites Contaminated with Aviation Gasoline or Jet Fuel  

PubMed Central

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. Samples were taken from the unsaturated zone to depths slightly below the floating free product in the saturated zone. 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. The same trends were noted in the biotreatment area, except that numbers of protozoa were higher. 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. Little reduction in hydraulic conductivity was observed, and no bacterial fouling of the aquifer was observed during biotreatment. PMID:16348871

Sinclair, James L.; Kampbell, Don H.; Cook, Mike L.; Wilson, John T.

1993-01-01

135

Modeling of multiphase transport of multicomponent organic contaminants and heat in the subsurface: Numerical model formulation  

SciTech Connect

A numerical compositional simulator (Multiphase Multicomponent Nonisothermal Organics Transport Simulator (M[sup 2]NOTS)) has been developed for modeling transient, three-dimensional, nonisothermal, and multiphase transport of multicomponent organic contaminants in the subsurface. The governing equations include (1) advection of all three phases in response to pressure, capillary, and gravity forces; (2) interphase mass transfer that allows every component to partition into each phase present; (3) diffusion; and (4) transport of sensible and latent heat energy. Two other features distinguish M[sup 2]NOTS from other simulators reported in the groundwater literature: (1) the simulator allows for any number of chemical components and every component is allowed to partition into all fluid phases present, and (2) each phase is allowed to completely disappear from, or appear in, any region of the domain during a simulation. These features are required to model realistic field problems region of the domain during a simulation. These features are required to model realistic field problems involving transport of mixtures of nonaqueous phase liquid contaminants, and to quantify performance of existing and emerging remediation methods such as vacuum extraction and steam injection. 74 refs., 1 fig.

Adenekan, A.E. (Exxon Production Research Company, Houston, TX (United States)); Patzek, T.W. (Univ. of California, Berkeley (United States)); Pruess, K. (Lawrence Berkeley Lab., CA (United States))

1993-11-01

136

Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site.  

PubMed

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. PMID:22179233

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; Kostka, Joel E

2012-02-01

137

BIOREMEDIATION OF PETROLEUM HYDROCARBON CONTAMINANTS IN MARINE HABITATS  

EPA Science Inventory

Bioremediation is being increasingly seen as an effective environmentally benign treatment for shorelines contaminated as a result of marine oil spills. Despite a relatively long history of research on oil-spill bioremediation, it remains an essentially empirical technology and m...

138

Bioremediation of petroleum hydrocarbon contaminants in marine habitats  

Microsoft Academic Search

Bioremediation is being increasingly seen as an effective, environmentally benign treatment for shorelines contaminated as a result of marine oil spills. Despite a relatively long history of research on oil-spill bioremediation, it remains an essentially empirical technology and many of the factors that control bioremediation have yet to be adequately understood. Nutrient amendment is a widely accepted practice in oil-spill

Ian M Head; Richard PJ Swannell

1999-01-01

139

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

USGS Publications Warehouse

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 ??mol g-1 (dry weight) day-1 while oxygen concentration decreased at a rate of 0.124 ??mol 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. Also, the community is strongly nitrogen limited, and nitrogen additions may be required to significantly enhance hydrocarbon biodegradation.

Aelion, C.M.; Bradley, P.M.

1991-01-01

140

Remediation of sandy soils contaminated with hydrocarbons and halogenated hydrocarbons by soil vapour extraction.  

PubMed

This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%. PMID:22561947

Albergaria, José Tomás; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

2012-08-15

141

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

142

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

143

Bioremediation of petroleum hydrocarbon-contaminated ground water: The perspectives of history and hydrology  

USGS Publications Warehouse

Bioremediation, the use of microbial degradation processes to detoxify environmental contamination, was first applied to petroleum hydrocarbon-contaminated ground water systems in the early 1970s. Since that time, these technologies have evolved in some ways that were clearly anticipated early investigators, and in other ways that were not foreseen. The expectation that adding oxidants and nutrients to contaminated aquifers would enhance biodegradation, for example, has been born out subsequent experience. Many of the technologies now in common use such as air sparging, hydrogen peroxide addition, nitrate addition, and bioslurping, are conceptually similar to the first bioremediation systems put into operation. More unexpected, however, were the considerable technical problems associated with delivering oxidants and nutrients to heterogeneous ground water systems. Experience has shown that the success of engineered bioremediation systems depends largely on how effectively directions and rates of ground water flow can be controlled, and thus how efficiently oxidants and nutrients can be delivered to contaminated aquifer sediments. The early expectation that injecting laboratory-selected or genetically engineered cultures of hydrocarbon-degrading bacteria into aquifers would be a useful bioremediation technology has not been born out subsequent experience. Rather, it appears that petroleum hydrocarbon-degrading bacteria are ubiquitous in ground water systems and that bacterial addition is usually unnecessary. Perhaps the technology that was least anticipated early investigators was the development of intrinsic bioremediation. Experience has shown that natural attenuation mechanisms - biodegradation, dilution, and sorption - limit the migration of contaminants to some degree in all ground water systems. Intrinsic bioremediation is the deliberate use of natural attenuation processes to treat contaminated ground water to specified concentration levels at predetermined points in the aquifer. In current practice, intrinsic bioremediation of petroleum hydrocarbons requires a systematic assessment to show that ambient natural attenuation mechanisms are efficient enough to meet regulatory requirements and a monitoring program to verify that performance requirements are met in the future.

Chapelle, F. H.

1999-01-01

144

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

145

Efficiency of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from contaminated soil.  

PubMed

This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil. PMID:23681773

Singh, Anil Kumar; Cameotra, Swaranjit Singh

2013-10-01

146

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

2013-09-01

147

Biogeochemical evidence for subsurface hydrocarbon occurrence, Recluse oil field, Wyoming; preliminary results  

USGS Publications Warehouse

Anomalously high manganese-to-iron ratios occurring in pine needles and sage leaves over the Recluse oil field, Wyoming, suggest effects of petroleum microseepage on the plants. This conclusion is supported by iron and manganese concentrations in soils and carbon and oxygen isotope ratios in rock samples. Seeping hydrocarbons provided reducing conditions sufficient to enable divalent iron and manganese to be organically complexed or adsorbed on solids in the soils. These bound or adsorped elements in the divalent state are essential to plants, and the plants readily assimilate them. The magnitude of the plant anomalies, combined with the supportive isotopic and chemical evidence confirming petroleum leakage, makes a strong case for the use of plants as a biogeochemical prospecting tool.

Dalziel, Mary C.; Donovan, Terrence J.

1980-01-01

148

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

149

Coupling of Groundwater Recharge and Biodegradation of Subsurface Crude-Oil Contamination (Invited)  

NASA Astrophysics Data System (ADS)

Surface hydrologic properties controlling groundwater recharge can have a large effect on biodegradation rates in the subsurface. Two studies of crude oil contamination show that degradation rates are dramatically increased where recharge rates are enhanced. The first site, located near Bemidji, Minnesota, was contaminated in August, 1979 when oil from a pipeline rupture infiltrated into a surficial glacial outwash aquifer. Discrete oil phases form three separate pools at the water table, the largest of which is 25x75 m at a depth of 6-8 m. Gas and water concentrations and microbial community data show that methanogenic conditions prevail in this oil pool. There is extreme spatial dependence in the degradation rates such that most of the n-alkanes have been degraded in the upgradient end, but in the downgradient end n-alkane concentrations are nearly unaltered from the original spill. Recharge rates through the two ends of the oil body were estimated using a water table fluctuation method. In 2002, the more degraded end received 15.2 cm of recharge contrasted to 10.7 cm at the less degraded end. The enhanced recharge is caused by topographic focusing of runoff toward a local depression. Microbial data using the Most Probable Number method show that the methanogen concentrations are 10-100 times greater in the more degraded end of the oil body suggesting that a growth nutrient is supplied by recharge. A decrease in partial pressure of N2 compared to Ar in the soil gas indicates nitrogen fixation probably meets N requirements (Amos et al., 2005, WRR, doi:10.1029/2004WR003433). Organic phosphorus is the main form of P in infiltrating pore water and concentration decreases with depth. The second site is located 40 km southeast of the Bemidji site at an oil pipeline pumping station near Cass Lake, Minnesota. This site was contaminated by oil leaking from a pipe coupling for an unknown duration of time between 1971 and 2002. The oil body at this site lies under a fenced area of the pumping station and is comparable in size to the largest Bemidji site oil pool. The oil is heavily degraded with complete loss of the n-alkane fraction suggesting that degradation is accelerated at this site. The pumping station is flat, gravel-covered, devoid of vegetation, and surrounded by a berm. Thus, the combined effects of no runoff, rapid infiltration, and zero transpiration all enhance recharge to the oil body. Recharge rates through the gravel yard and the adjacent forested area were estimated using a water table fluctuation method. Data for the first six months of 2010 showed that recharge below the gravel yard was 40% greater than below the forested area. Groundwater ammonia concentrations increase from 0.02 to 0.5 mmol/L under the oil body, while background NO3 is only 0.01 mmol/L and there is negligible N in the oil, again suggesting that N fixation meets N requirements. Combined, these studies suggest that enhanced transport of a limiting nutrient other than N from the surface may accelerate degradation of subsurface contamination.

Bekins, B. A.; Hostettler, F. D.; Delin, G. N.; Herkelrath, W. N.; Warren, E.; Campbell, P.; Rosenbauer, R. J.; Cozzarelli, I.

2010-12-01

150

Monitored natural attenuation of a long-term petroleum hydrocarbon contaminated sites: a case study.  

PubMed

This study evaluated the potential of monitored natural attenuation (MNA) as a remedial option for groundwater at a long-term petroleum hydrocarbon contaminated site in Australia. Source characterization revealed that total petroleum hydrocarbons (TPH) as the major contaminant of concern in the smear zone and groundwater. Multiple lines of evidence involving the geochemical parameters, microbiological analysis, data modelling and compound-specific stable carbon isotope analysis all demonstrated natural attenuation of hydrocarbons occurring in the groundwater via intrinsic biodegradation. Groundwater monitoring data by Mann-Kendall trend analysis using properly designed and installed groundwater monitoring wells shows the plume is stable and neither expanding nor shrinking. The reason for stable plume is due to the presence of both active source and natural attenuation on the edge of the plume. Assuming no retardation and no degradation the contaminated plume would have travelled a distance of 1,096 m (best case) to 11,496 m (worst case) in 30 years. However, the plume was extended only up to about 170 m from its source. The results of these investigations provide strong scientific evidence for natural attenuation of TPH in this contaminated aquifer. Therefore, MNA can be applied as a defensible management option for this site following significant reduction of TPH in the source zone. PMID:22899178

Naidu, Ravi; Nandy, Subhas; Megharaj, Mallavarapu; Kumar, R P; Chadalavada, Sreenivasulu; Chen, Zuliang; Bowman, Mark

2012-11-01

151

Enzymatic bioremediation of polyaromatic hydrocarbons by fungal consortia enriched from petroleum contaminated soil and oil seeds.  

PubMed

The present study focuses on fungal strains capable of secreting extracellular enzymes by utilizing hydrocarbons present in the contaminated soil. Fungal strains were enriched from petroleum hydrocarbons contaminated soil samples collected from Chennai city, India. The potential fungi were isolated and screened for their enzyme secretion such as lipase, laccase, peroxidase and protease and also evaluated fungal enzyme mediated PAHs degradation. Total, 21 potential PAHs degrading fungi were isolated from PAHs contaminated soil, which belongs to 9 genera such as Aspergillus, Curvularia, Drechslera, Fusarium, Lasiodiplodia, Mucor Penicillium, Rhizopus, Trichoderma, and two oilseed-associated fungal genera such as Colletotrichum and Lasiodiplodia were used to test their efficacy in degradation of PAHs in polluted soil. Maximum lipase production was obtained with P. chrysogenum, M. racemosus and L. theobromae VBE1 under optimized cultural condition, which utilized PAHs in contaminated soil as sole carbon source. Fungal strains, P. chrysogenum, M. racemosus and L. theobromae VBE1, as consortia, used in the present study were capable of degrading branched alkane isoprenoids such as pristine (C17) and pyrene (C18) present in PAHs contaminated soil with high lipase production. The fungal consortia acts as potential candidate for bioremediation of PAHs contaminated environments. PMID:24813008

Balaji, V; Arulazhagan, P; Ebenezer, P

2014-05-01

152

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

NASA Astrophysics Data System (ADS)

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 samples that have not been heavily contaminated by the mud used to drill the wells. To address this issue, a “clean-sampling method” deploying the newly developed Schlumberger Quicksilver MDT probe was used to collect a subsurface sample at a depth of 1.79 km (5872 ft) from an exploratory well within Cambrian-age sandstones in the Illinois Basin. This yielded a formation water sample that was determined to have less than 4% drilling mud contamination based on tracking changes in the aqueous geochemistry of the formation water during ~3 hours of pumping at depth prior to sample collection. A suite of microscopy and culture-independent molecular analyses were completed using the DNA extracted from microbial cells in the formation water, which included 454 amplicon pyrosequencing that targeted the V1-V3 hypervariable region of bacterial 16S rRNA gene sequences. Results demonstrated an extremely low diversity microbial community living in formation water at 1.79 km-depth. More than 95 % of the total V1-V3 pyrosequencing reads (n=11574) obtained from the formation water were affiliated with a halophilic ?-proteobacterium and most closely related to the genus Halomonas. In contrast, about 3 % of the V1-V3 sequences in the drilling mud library (n=13044) were classified as genus Halomonas but were distinctly different and distantly related to the formation water Halomonas detected at 1.79 km-depth. These results were consistent with those obtained using a suite of other molecular screens (e.g., Terminal-Restriction Fragment Length Polymorphism (T-RFLP) and the initial full length 16S rRNA amplicon libraries) and bioinformatic analyses (e.g., 16S rRNA and Open Reading Frame (ORF) calls established from the 454 metagenomic community analyses). Functional pathway modeling is underway to evaluate the adaptation of this indigenous microbial community to the hydrologic and geologic history of the deep subsurface environment of the Illinois Basin.

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

2010-12-01

153

Use of the FIDLER Scintillation Probe for the Characterization of Subsurface Radionuclide Contamination  

SciTech Connect

The Measurement Applications and Development Group at the Oak Ridge National Laboratory has used a FIDLER to characterize a site where numerous localized and dispersed concentrations of uranium had been previously discovered beneath a poured concrete floor. The thick floor impeded the evaluation of the distribution of regions containing uranium without boring numerous holes through the concrete. The purpose of this study was to perform a radiological assessment of the building in preparation for remediation of the site. Integrated counts were taken with the FIDLER probes fixed in place on a systematic grid across the area to be evaluated. The results were then superimposed on a drawing of the area of evaluation. This approach allowed the boundaries of the regions with subsurface contamination to be resolved much better than by using standard survey techniques and decreased the number of borehole samples and subsequent analyses. The study demonstrated that this survey technique provides rapid and essential characterization information and reduces sampling, analytical, and remediation costs.

Coleman, R.L.; Murray, M.E.

1999-11-14

154

Studies on the dissolution of polycyclic aromatic hydrocarbons from contaminated materials using a novel dialysis tubing experimental method  

Microsoft Academic Search

Assessment of risk and remediation strategies at contaminated sites requires that both the amounts of contaminants present and their potential for release from materials and soils be evaluated. The release, or dissolution, of polycyclic aromatic hydrocarbons (PAHs) from contaminated materials to water was therefore investigated. To facilitate investigations of PAH dissolution from physically disparate materials such as solid coal tars,

Paula J. Woolgar; Kevin C. Jones

1999-01-01

155

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

156

Occurrence and distribution of polycyclic aromatic hydrocarbons in surface microlayer and subsurface seawater of Lagos Lagoon, Nigeria.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) in surface microlayer (SML) and subsurface water (SSW) of Lagos Lagoon were investigated using gas chromatography-electron capture detector (GC-ECD) technique to ascertain their occurrence and spatial distribution, origin, enrichment, and carcinogenicity. Total PAH (?PAH) concentrations ranged from 9.10 to 16.20 ?g L(-1) in the SML and 8.90 to 13.30 ?g L(-1) in the SSW. ?PAH concentrations were relatively higher in the SML than the underlying SSW samples. The enrichment factors (EFs) of ?PAHs ranged from 0.76 to 1.74 while the EFs of the individual PAHs varied from 0.50 to 2.09. In general, the EFs values calculated in this study were consistent or slightly less than the EFs reported for similar coastal seawater ecosystems. A correlation between the EFs of fluoranthene and pyrene indicated a positive significant value (R?=?0.9828, p?

Benson, Nsikak U; Essien, Joseph P; Asuquo, Francis E; Eritobor, Adeola L

2014-09-01

157

State of subsoil in a former petrol station: physicochemical characterization and hydrocarbon contamination evaluation  

NASA Astrophysics Data System (ADS)

Former petrol stations are, possibly, potential hydrocarbon contaminated soil areas due to leakage in Underground Storage Tanks and fuel dispensing activities. Volatile Organic Compounds (VOCs) in gasoline, like benzene and semi-volatile organics in diesel, are carcinogenic and very toxic substances which can involve a serious risk for ecosystem and human health. Based on Electrical Resistivity Tomography 2D results from a previous work, there have been selected three potentially contaminated goal areas in a former petrol station located in SE Spain in order to obtain soil samples by drilling and to assess the gasoline and diesel contamination. A special sampling design was carried out and soil samples for VOCs were preserved at field with a KCl solution to minimize volatilization losses. It had been chosen Headspace-GC-MS as the better technique to quantify individual VOCs and GC-FID to get a Total Petroleum Hydrocarbon (TPH) assessment after a solid/fluid pressurized extraction. The physicochemical characterization of the subsoil was performed to know how humidity, clay content or pH data could be related to the presence of hydrocarbons in the soil samples. Results show that VOCs concentrations in subsoil samples of the petrol station are around ppb levels. TPH ranged between 17 mg/kg soil and 93 mg/kg soil (ppm levels) what involves diesel and gasoline leaks due to these detected residual concentrations in the subsoil. The maximum value was found at 6 m deep in an intermediate zone between Underground Storage Tanks positions (located at 4 m deep). Therefore, these results confirm that organic compounds transference with strong vertical component has taken place. It has been observed that humidity minimum values in the subsoil are related to TPH maximum values that could be explained because of the vapour phase and the retention of hydrocarbon in soil increases when humidity goes down. Adsorption of hydrocarbons in the subsoil tend to be pH-dependent and clay content dependent: maximum of adsorption taken place at minimum pH what encourage protonation and minimum clay content in the subsoil make organic compounds infiltration downstream easier. It could be noticed the importance of physicochemical subsoil characterization and contamination assessment in the subsoil of petrol stations in order to avoid the hydrocarbons pollution of the groundwater. Then plan the best remediation technique according to this characterization taking into account the residual hydrocarbon concentration in the subsoil and the associated risk for human and ecosystems.

María Rosales, Rosa; Martinez-Pagán, Pedro; Faz, Ángel; Bech, Jaume

2013-04-01

158

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

2012-05-01

159

Geochemical and isotopic characteristics associated with high soil 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 at a hydrocarbon-contaminated site in SW Michigan showed high conductivities associated with the zone of contamination. Within the contaminated portion of the aquifer, different phases of hydrocarbon impact are recognized, namely, zones with residual and dissolved phase hydrocarbons (RDH) and zones where these phases coexist with free product (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). Geochemical and isotopic data from closely spaced vertical samples within the high conductive zones were used to provide geochemical evidence for biodegradation and to investigate redox processes occurring within the conductive zones. Depth distribution of TEAs and educts showed evidence of reduction of nitrate, iron, manganese, and sulfate across steep vertical gradients. Within the portion of the plume characterized by RDH, SO4 reduction has supplanted denitrification via dissimilatory nitrate reduction, and the reduction of Fe (III) and Mn(IV) as the major observed redox process. This zone was also characterized by the highest DIC. The delta 13CDIC values of -16.9 to -9.5‰ suggest that DIC evolution within this zone is controlled by carbonate dissolution through enhanced CO2 production related to microbial hydrocarbon degradation. Within the portion of the aquifer with RDFH, DIC was lower compared to the RDH location with an associated delta13CDIC in the range of +6.5 to -4.4‰. Both the DIC and delta 13CDIC suggest that methanogenesis is the dominant redox process. With respect to mineral weathering as a possible source of ions contributing to high conductivities, the results show higher concentrations of Na, Ca, and Mg in the contaminated portion of the aquifer compared to uncontaminated parts. This is consistent with the weathering of carbonate and Na and Ca feldspars, the dominant minerals in the aquifer. Higher TDS at the contaminated locations were also coincident with higher DIC, and increased CO2 production. In general, both TDS and bulk soil conductivity increased with depth at the contaminated and uncontaminated locations. TDS and bulk conductivity were positively correlated at the uncontaminated location, suggesting that TDS was a good predictor of bulk conductivity. However, at the contaminated locations, the correlation between the bulk conductivity and the TDS was poorer, the lack of correlation being more so in portions of the aquifer with free phase hydrocarbons (RDFH). This may suggest that the TDS may not reliably predict the bulk conductivities of hydrocarbon-impacted soils. The present study seeks to provide a likely interrelationship between redox processes, biomineralization of hydrocarbons, and high bulk soil conductivities. Moreover, high conductivities measured at hydrocarbon-contaminated sites may be useful in assessing the potential for natural attenuation and to monitor intrinsic bioremediation at these sites.

Legall, Franklyn David

160

Aliphatic hydrocarbons in an oil-contaminated soil: Carbon economy during microbiological decontamination.  

PubMed

Microbial decontamination of hydrocarbon-polluted soil was paralleled with soil respiration measurements. About 1,500 tons of a loamy top soil were found to be contaminated with approximately 2000 mg/kg of aliphatic hydrocarbons, mainly oleic (C18:1) and linoleic acid (C18:2) found in the vicinity of a linoleum manufacturing and then a car dewaxing plant. The contaminated soil was analysed for dry matter, pH, dehydrogenase activity, electrical conductivity and nutrient content viz. nitrate, phosphorus and potassium, as well as a number of indigenous microbes. The soil was low in salt and nutrients. This paper describes the procedure and measures to decontaminate this bulk soil on site from approx. 2,000 to 500 mg of aliphatic hydrocarbons/kg dry matter by use of a nutrient emulsion, indigenous micro-organisms and aeration over 13 months. This 75% reduction in aliphatic hydrocarbons resulted in a concomitant carbon efflux, measured as soil respiration, and was used to calculate carbon fluxes. PMID:19005855

Wibbe, M L; Blanke, M M

1999-01-01

161

Remediation of petroleum hydrocarbon-contaminated sites by DNA diagnosis-based bioslurping technology.  

PubMed

The application of effective remediation technologies can benefit from adequate preliminary testing, such as in lab-scale and Pilot-scale systems. Bioremediation technologies have demonstrated tremendous potential with regards to cost, but they cannot be used for all contaminated sites due to limitations in biological activity. The purpose of this study was to develop a DNA diagnostic method that reduces the time to select contaminated sites that are good candidates for bioremediation. We applied an oligonucleotide microarray method to detect and monitor genes that lead to aliphatic and aromatic degradation. Further, the bioremediation of a contaminated site, selected based on the results of the genetic diagnostic method, was achieved successfully by applying bioslurping in field tests. This gene-based diagnostic technique is a powerful tool to evaluate the potential for bioremediation in petroleum hydrocarbon contaminated soil. PMID:25129160

Kim, Seungjin; Krajmalnik-Brown, Rosa; Kim, Jong-Oh; Chung, Jinwook

2014-11-01

162

Laboratory studies of the remediation of polycyclic aromatic hydrocarbon contaminated soil by in-vessel composting  

Microsoft Academic Search

The biodegradation of 16 polycyclic aromatic hydrocarbons (PAHs), listed as priority pollutants by the USEPA, present in a coal-tar-contaminated soil from a former manufactured gas plant site was investigated using laboratory-scale in-vessel composting reactors to determine the suitability of this approach as a bioremediation technology. Preliminary investigations were conducted over 16 weeks to determine the optimum soil composting temperature (38,

Blanca Antizar-Ladislao; Joseph Lopez-Real; Angus J. Beck

2005-01-01

163

Bioremediation of hydrocarbon contaminated-oil field drill-cuttings with bacterial isolates  

Microsoft Academic Search

The effectiveness of 2 bacterial isolates (Bacillus subtilis and Pseudomonas aeruginosa) in the restoration of oil-field drill-cuttings contaminated with polycyclic aromatic hydrocarbons (PAHs) was studied. A mixture of 4 kg of the drill-cuttings and 0.67 kg of top-soil were charged into triplicate plastic reactors labeled A1 to A3, B1 to B3, C1 to C3 and O1 to O3. These were

Reuben N. Okparanma; Josiah M. Ayotamuno; Peremelade P. Arak

2009-01-01

164

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

Microsoft Academic Search

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

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

2010-01-01

165

PHENOTYPIC RESPONSES OF THE SOIL BACTERIAL COMMUNITY TO POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATION IN SOILS  

Microsoft Academic Search

Five soils with different levels of polycyclic aromatic hydrocarbon (PAH) and metallic contamination were sampled from a former coke facility site located in the north of France. Among PAH-degrading microbiota, naphthalene-degraders were ubiquitous, whereas bacteria-degrading PAHs of more than two rings were present in only the polluted soils, in the range of 1% to 10% of the total microbiota. Phenotypic

C. Lors; J. R. Mossmann; P. Barbé

2004-01-01

166

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

167

CROSS-INDUCTION OF PYRENE AND PHENANTHRENE IN MYCOBACTERIUM SP. ISOLATED FROM POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATED RIVER SEDIMENTS  

EPA Science Inventory

A polycyclic aromatic hydrocarbon (PAH)-degrading culture enriched from contaminated river sediments and a Mycobacterium sp. isolated from the enrichment were tested to investigate the possible synergistic and antagonistic interactions affecting the degradation of pyrene in the p...

168

PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES  

EPA Science Inventory

The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

169

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...

170

Forensic differentiation of biogenic organic compounds from petroleum hydrocarbons in biogenic and petrogenic compounds cross-contaminated soils and sediments  

Microsoft Academic Search

“Total petroleum hydrocarbons” (TPHs) or “petroleum hydrocarbons” (PHCs) are one of the most widespread soil pollutants in Canada, North America, and worldwide. Clean-up of PHC-contaminated soils and sediments costs the Canadian economy hundreds of million of dollars annually. Much of this activity is driven by the need to meet regulated levels of PHC in soil. These PHC values are legally

Zhendi Wang; C. Yang; F. Kelly-Hooper; B. P. Hollebone; X. Peng; C. E. Brown; M. Landriault; J. Sun; Z. Yang

2009-01-01

171

Field metabolomics and laboratory assessments of anaerobic intrinsic bioremediation of hydrocarbons at a petroleum-contaminated site  

Microsoft Academic Search

Summary Field metabolomics and laboratory assays were used to assess the in situ anaerobic attenuation of hydrocarbons in a contaminated aquifer underly- ing a former refinery. Benzene, ethylbenzene, 2- methylnaphthalene, 1,2,4- and 1,3,5-trimethylbenzene were targeted as contaminants of greatest regulatory concern (COC) whose intrinsic remediation has been previously reported. Metabolite profiles associated with anaerobic hydrocarbon decay revealed the microbial utilization

Victoria A. Parisi; Gaylen R. Brubaker; Matthew J. Zenker; Roger C. Prince; Lisa M. Gieg; Marcio L. B. da Silva; Pedro J. J. Alvarez; Joseph M. Suflita

2009-01-01

172

Refined gasoline in the subsurface  

SciTech Connect

Geologists today are being called upon not only to find naturally occurring petroleum, but also to help assess and remediate the problem of refined hydrocarbons and other man-made contaminants in the subsurface that may endanger freshwater resources or human health. Petroleum geologists already have many of the skills required and are at ease working with fluid flow in the subsurface. If called for environmental projects, however, they will need to know the language and additional concepts necessary to deal with the hydrogeologic problems. Most releases of refined hydrocarbons and other man-made contaminants occur in the shallow unconfined groundwater environment. This is divided into three zones: the saturated zone, unsaturated zone, and capillary fringe. All three have unique characteristics, and contamination behaves differently in each. Gasoline contamination partitions into four phases in this environment; vapor phase, residual phase, free phase, and dissolved phase. Each has a different degree of mobility in the three subsurface zones. Their direction and rate of movement can be estimated using basic concepts, but geological complexities frequently complicate this issue. 24 refs., 19 figs., 4 tabs.

Bruce, L.G. (Amoco Corporation, Tulsa, OK (United States))

1993-02-01

173

Sequential electron acceptor model for evaluation of in situ bioremediation of petroleum hydrocarbon contaminants in groundwater.  

PubMed

Mathematical development and model application is provided for a multiple substrate, sequential electron acceptor model, accounting for hydrodynamic transport, adsorption, and sequential oxygen/iron(III)-based biodegradation. Equations for iron(III)-based biodegradation of petroleum hydrocarbons are developed based on oxygen-inhibited Monod kinetics. The iron(III)-based biodegradation expressions were combined with earlier work by Widdowson and Aelion, to develop the two-dimensional, multiple substrate, oxygen/iron(III) sequential electron acceptor biodegradation model presented here. In addition to mathematical model development, simulations demonstrating the advantages of sequential electron acceptor and multiple substrate biodegradation models are provided. These simulations show that commonly-used single electron acceptor models may underpredict natural, in situ biodegradation potential at sites where indigenous microorganisms are capable of using multiple electron acceptors. Additional simulations show that, for contaminant plumes composed of constituents which biodegrade at different rates and under varying electron acceptor conditions, a multiple substrate model may allow more accurate prediction of both individual contaminant concentrations and the total amount of biodegraded contaminant. Considering that typical contaminant plumes are composed of multiple constituents with varying biodegradation properties and health risks, multiple substrate sequential electron acceptor models have the potential to provide more accurate tracking of individual constituent migration. The model was applied to a leaking UST site in Laurel Bay, South Carolina. Laboratory and monitoring well data presented in Landmeyer et al. have established that the petroleum hydrocarbon contaminants are present in the groundwater and are undergoing sequential oxygen-iron(III)-based biodegradation. Model simulations proved capable of reproducing the trends observed at the Laurel Bay site in that BTX contaminants were removed by sequential biodegradation, occurring first aerobically and subsequently anaerobically, and that iron(III)-reducing organisms biodegrade contaminants only in the absence of oxygen. The BTX compounds were individually but simultaneously modeled, allowing explicit modeling of specific contaminant biodegradation properties (e.g., toluene and xylene are assumed to degrade sequentially and benzene is assumed to degrade aerobically only). Although simulations presented here can reproduce trends observed at the Laurel Bay site, inclusion of additional electron acceptors and additional model calibration to data from this and other sites is necessary to improve and verify the model's capability to predict the efficacy of intrinsic biodegradation of petroleum hydrocarbon contaminants in groundwater. PMID:9472325

Brauner, J S; Widdowson, M A

1997-11-21

174

Bioremediation of contaminated groundwater  

DOEpatents

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

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

1995-01-01

175

Bioremediation of contaminated groundwater  

DOEpatents

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

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

1995-01-24

176

Effects of oxygen supply on the biodegradation rate in oil hydrocarbons contaminated soil  

NASA Astrophysics Data System (ADS)

Respirometry studies using the 10-chamber Micro-Oxymax respirometer (Columbus, Ohio) were conducted to determine the effect of biostimulation (by diverse ways of O2 supply) on enhancing biodegradation in soils contaminated with oil hydrocarbons. Soil was collected from a former military airport in Kluczewo, Poland. Oxygen was supplied by means of aerated water, aqueous solutions of H2O2 and KMnO4. The biodegradation was evaluated on the basis of O2 uptake and CO2 production. The O2 consumption and CO2 production rates during hydrocarbons biodegradation were estimated from the slopes of cumulative curve linear regressions. The pertinent intrinsic and enhanced biodegradation rates were calculated on the basis of mass balance equation and O2 uptake and CO2 production rates. The biodegradation rates of 5-7 times higher as compared to a control were observed when the aqueous solution of KMnO4 in concentration of 20 g L-1 was applied. Permanganate is known to readily oxidize alkene carbon - carbon double bonds; so it can be successfully applied in remediation technology for soils contaminated with oil hydrocarbons. While hydrocarbons are not completely mineralized by permanganate oxidation reactions, their structure is altered by polar functional groups providing vast improvements in aqueous solubility and availability for biodegradation. The 3% aqueous solution of H2O2 caused significant improvement of the biodegradation rates as compared to a control (on average about 260%). Aerobic biodegradation of hydrocarbons can benefit from the presence of oxygen released during H2O2 decomposition. Adding of aerated water resulted in an increase of biodegradation rates (about 114 - 229%) as compared to a control. The aerated water can both be the source of oxygen for microorganisms and determine the transport of substrate to bacteria cells.

Zawierucha, I.; Malina, G.

2011-04-01

177

A protocol for assessing the biotreatability of hydrocarbon contaminated exploration and production site soils  

SciTech Connect

It is estimated that there are over 260,000 natural gas production wells in the continental United States. Production or reserve pits exist which ma require remediation depending on several conditions such as: the manner in which they were initially closed; whether or not they were lined; and the local climate, soil type, and depth to groundwater. As part of the Gas Research Institute (GRI) research program on exploration and production (E&P) site remediation, a treatability Protocol is being developed to facilitate the rapid assessment of the amenability of the contaminated soils to remediation by biological processes. This paper describes the treatability protocol and the results of a series of treatability tests on a spectrum of hydrocarbon contaminated E&P soils collected from various operating locations throughout the United States. The soils are subjected to physical and chemical characterization prior to treatability testing. Potential biotoxic characteristics of the soils are determined by a respirometry screening technique. Presuming that the soils are not toxic to aerobic soil microorganisms, 20 percent by weight aqueous slurries of the soils are prepared and subjected to continuous batch aeration for a six week period. Conditions favorable to microbial growth are maintained in the reactors by monitoring and augmentation is needed of pH, microbial nutrients and oxygen for microbial respiration. The extent of microbial degradation of the contaminant hydrocarbons is monitored by periodic measurement of total petroleum hydrocarbons (TPH), oil and grease, and individual hydrocarbon compounds as determined by gas chromatography. Microbial plate counts are prepared to document the biological viability of the treatment process. The factors influencing the amenability of these soils to bioremediation as determined from the test results are discussed.

Tezak, J.; Miller, J.A.; Lawrence, A.W. [and others

1995-12-01

178

Characterization of the bacterial archaeal diversity in hydrocarbon-contaminated soil.  

PubMed

A polyphasic approach combining culture-based methods with molecular methods is useful to expand knowledge on microbial diversity in contaminated soil. Microbial diversity was examined in soil samples from a former industrial site in the European Alps (mainly used for aluminum production and heavily contaminated with petroleum hydrocarbons) by culture-dependent and culture-independent methods. The physiologically active eubacterial community, as revealed by fluorescence-in-situ-hybridization (FISH), accounted for 6.7% of the total (DAPI-stained) bacterial community. 4.4% and 2.0% of the DAPI-stained cells could be attributed to culturable, heterotrophic bacteria able to grow at 20°C and 10°C, respectively. The majority of culturable bacterial isolates (34/48) belonged to the Proteobacteria (with a predominance of Alphaproteobacteria and Gammaproteobacteria), while the remaining isolates were affiliated with the Actinobacteria, Cytophaga-Flavobacterium-Bacteroides and Firmicutes. A high fraction of the culturable, heterotrophic bacterial population was able to utilize hydrocarbons. Actinobacteria were the most versatile and efficient degraders of diesel oil, n-alkanes, phenol and PAHs. The bacterial 16S rRNA gene clone library contained 390 clones that grouped into 68 phylotypes related to the Proteobacteria, Bacteroidetes, Actinobacteria and Spirochaetes. The archaeal 16S rRNA gene library contained 202 clones and 15 phylotypes belonging to the phylum Euryarchaeota; sequences were closely related to those of methanogenic archaea of the orders Methanomicrobiales, Methanosarcinales, Methanobacteriales and Thermoplasmatales. A number of bacterial and archaeal phylotypes in the clone libraries shared high similarities with strains previously described to be involved in hydrocarbon biodegradation. Knowledge of the bacterial and archaeal diversity in the studied soil is important in order to get a better insight into the microbial structure of contaminated environments and to better exploit the bioremediation potential by identifying potential hydrocarbon degraders and consequently developing appropriate bioremediation strategies. PMID:22386232

Zhang, De-Chao; Mörtelmaier, Christoph; Margesin, Rosa

2012-04-01

179

Resistivity and Induced Polarization Imaging at a Hydrocarbon Contaminated Site in Brazil  

NASA Astrophysics Data System (ADS)

An area contaminated by accidental BTEX spills was investigated with resistivity and induced polarization methods. The main objective in this study was to relate the geophysical signature of the area with zones that were possibly undergoing microbial degradation of the contaminants. The spills took place over a decade ago; however, the exact location of these spills is unknown, as well as the amount of contaminant that was released into the subsurface. DC-resistivity identified a high contrast between the background (rho up to 2000 ohm.m) and a relatively conductive zone (rho < 100 ohm.m), where high chargeabilities were also measured (m > 30 mV/V). Normalized chargeability is enhanced in this anomaly zone (mn > 0.1). Soil samples collected in the area were submitted to direct bacterial count, clay content estimation, X-ray diffraction and SEM analysis. The electrical properties of each samples was also measured. The samples collected from the "background" (high resistivity zone) presented total bacterial amounts much smaller (dozens of colony forming units) than the samples from the conductive zone (millions of colony forming units). This observation could lead us to interpret that the zone of higher bacteria amount is undergoing biodegradation that would explain the increased conductivity at that portion of the subsurface. However, the geophysical properties observed at this zone could also be related to the clay content distribution throughout the surveyed area (concentrations up to 30%). Moreover, despite the fact that more microbes were found in the area, SEM images did not find any biodegradation typical feature of the grains, which are for example, mineral corrosion and dissolution or even biomineralization. This study is still undergoing and we are searching for more evidence of biodegradation in the samples. This study shows the limitation of the use of geophysical methods to access contaminant presence and/or biodegradation zones when the exact location of the contamination is unknown.

Ustra, A.; Elis, V.; Hiodo, F.; Bondioli, A.; Miura, G.

2012-12-01

180

Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1997 annual progress report  

SciTech Connect

'The overall objective of the basic research grant is to characterize the potential of common hydrocarbon contaminants in ecosystems to act as endocrine disruptors. The three major lines of research include (1) a biotechnology based screening system to identify potential hormone mimics and antagonists; (2) an animal screening system to identify biomarkers of endocrine effects. and (3) a literature review to identify compounds at a variety of DOE sites that need to be examined for endocrine disrupting effects. By relating results obtained from this research project to contamination problems at various DOE sites. CBR will provide data and information on endocrine disrupting contaminants to DOE for consideration in risk analyses for determining clean-up levels and priorities needed at the sites.'

NONE

1997-01-01

181

XPS study of the effect of hydrocarbon contamination on polytetrafluoroethylene (teflon) exposed to atomic oxygen  

NASA Technical Reports Server (NTRS)

The presence of hydrocarbon contamination on the surface of polytetrafluoroethylene (PTFE) markedly affects the oxygen uptake, and hence the wettability, of this polymer when exposed to an oxygen plasma. As revealed by X-ray photoelectron spectroscopy (XPS) analysis, the oxygen-to-carbon ratio (O/C) for such a polymer can increase sharply, and correspondingly the fluorine-to-carbon ratio (F/C) can decrease sharply, at very short exposure times; at longer times, however, such changes in the O/C and F/C ratios reverse direction, and these ratios then assume values similar to those of the unexposed PTFE. The greater the extent of hydrocarbon contamination in the PTFE, the larger are the amplitudes of the 'spikes' in the O/C- and F/C-exposure time plots. In contrast, a pristine PTFE experiences a very small, monotonic increase of surface oxidation or O/C ratio with time of exposure to oxygen atoms, while the F/C ratio is virtually unchanged from that of the unexposed polymer (2.0). Unless the presence of adventitious hydrocarbon is taken into account, anomalous surface properties relating to polymer adhesion may be improperly ascribed to PTFE exposed to an oxygen plasma.

Golub, Morton A.; Wydeven, Theodore; Cormia, Robert D.

1991-01-01

182

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

Microsoft Academic Search

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

R. Bonaccorsi; C. R. Stoker

2006-01-01

183

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

184

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...

185

Remediation of hydrocarbon-contaminated soils by ex situ microwave treatment: technical, energy and economic considerations.  

PubMed

In this study, the remediation of diesel-polluted soils was investigated by simulating an ex situ microwave (MW) heating treatment under different conditions, including soil moisture, operating power and heating duration. Based on experimental data, a technical, energy and economic assessment for the optimization of full-scale remediation activities was carried out. Main results show that the operating power applied significantly influences the contaminant removal kinetics and the moisture content in soil has a major effect on the final temperature reachable during MW heating. The first-order kinetic model showed an excellent correlation (r2 > 0.976) with the experimental data for residual concentration at all operating powers and for all soil moistures tested. Excellent contaminant removal values up to 94.8% were observed for wet soils at power higher than 600 W for heating duration longer than 30 min. The use of MW heating with respect to a conventional ex situ thermal desorption treatment could significantly decrease the energy consumption needed for the removal of hydrocarbon contaminants from soils. Therefore, the MW treatment could represent a suitable cost-effective alternative to the conventional thermal treatment for the remediation of hydrocarbon-polluted soil. PMID:25145181

Falciglia, P P; Vagliasindi, F G A

2014-01-01

186

Biomarker sensitivity for polynuclear and halogenated aromatic hydrocarbon contamination in fish species from Galveston Bay  

SciTech Connect

The Galveston Bay estuary exhibits a contamination gradient for polynuclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons, which is useful for comparing biomarker response sensitivity in fish taken from different bay locations. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), were collected from four stations where sediment total PAHs ranged from 68 to > 1,000 ng/g. Hardhead catfish showed no consistent CYP1A mediated responses (hepatic ethoxyresorufin-O-deethylase activity (EROD), CYP1A mRNA levels, or CYP1A immunoreactive protein) in the field collected fish or in fish dosed with up to 15 mg/kg benzo(a)pyrene (BaP). Significant differences were seen in field collected hardhead catfish in biliary concentrations of naphthalene, phenanthrene, and BaP metabolites. Conversely, in croakers taken from the same four Galveston Bay locations, there were significant elevations IN EROD and glutathione-S-transferase activities, CYP1A immunoreactive protein, and biliary PAH metabolites at the contaminated stations. These studies suggest that croaker is a good monitoring species especially with respect to induction of CYP1A mediated responses by PAHs. Biliary PAH metabolites and PAH-DNA adducts were sensitive to PAH contamination in both species.

Willett, K.; McDonald, S.; Steinberg, M.; Beatty, K.; Safe, S. [Texas A and M Univ., College Station, TX (United States)

1995-12-31

187

Effects of Temperature Changes on Biodegradation of Petroleum Hydrocarbons in Contaminated Soils from an Arctic Site  

NASA Astrophysics Data System (ADS)

Bioremediation is being considered as a cost-effective and a minimally disruptive remedial option at remote sites in the Arctic and sub-Arctic impacted by petroleum NAPL contamination. The implementation of on-site bioremediation in cold environments has been generally limited in the short, non-freezing summer months since ground remains frozen for 8-9 months of the year. This study evaluates the effect of different temperature regimes on petroleum hydrocarbon biodegradation rates and extent, as well as on the microbial activity. A series of pilot-scale landfarming bioremediation experiments (1 m×0.6 m×0.35 m soil tank dimension) was performed using aged, petroleum fuel-contaminated soils shipped from Resolution Island, Nunavut, Canada. These experiments were conducted under the following temperature conditions: (1) variable daily average field temperatures (1 to 10°C) representative of summers at the site; (2) constant mean temperature-mode with 6°C, representing typical stable laboratory incubation; and (3) under seasonal freeze-thaw conditions (-8°C to 10°C). Data to be presented include changes with time of petroleum hydrocarbons concentration fractionated by C-lengths, soil moisture (unfrozen water) contents, O2 and CO2 concentrations in soil pore gas, microbial population size and community composition in nutrient- amended and untreated landfarms. Hydrocarbon biodegradation and heterotrophic respiration activity was more rapid under the variable temperature cycle (1 to 10°C) than at a constant average temperature of 6°C, and total petroleum hydrocarbon (TPH) concentrations were reduced by 55% due to biodegradation over a 60 day test period under the variable temperature regime, compared to only 21% in soil tanks which were subjected to a constant temperature of 6°C. Shifts in microbial community were clearly observed in the both temperature modes using PCR-DGGE analyses and the emergence of a hydrocarbon-degrading population, Alkanindiges, was identified through 16S rRNA gene sequence analyses. Under the seasonal freeze-thaw conditions, microbial activity and hydrocarbon degradation was detected even when soils were frozen. The microbial activity was significantly correlated to residual unfrozen water contents.

Chang, W.; Klemm, S.; Whyte, L.; Ghoshal, S.

2009-05-01

188

Temporal evolution of the geoelectrical response on a hydrocarbon contaminated site  

NASA Astrophysics Data System (ADS)

A geoelectrical campaign was initiated in 2009 to delineate a massive hydrocarbon spill, which occurred because of a petroleum pipe breakdown in 2009. These measurements have been compared with both field resistivity measurements made in 2009 and with laboratory measurements. From a physicochemical point of view, a hydrocarbon contamination has to be understood as a spatially and temporally varying object, responsible for a change in geoelectrical response. To evaluate the signal measured on site, geoelectrical laboratory measurements were performed on the petroleum oil extracted from the site during two stages of degradation. On the laboratory scale, the non-degraded oil shows an increase in resistivity, normalized chargeability and quadrature conductivity with oil content, whereas the degraded oil indicates a slight decrease in resistivity, but no modification of the phase-lag and chargeability parameters. In the field, resistivity measurements performed in 2009, just after the pipe breakdown, show weak changes in resistivity measured over the contaminated area. However, between 2009 and 2012, biodegradation of the oil has led to a clear decrease in the resistivity within the impacted zone. No variations in normalized chargeability or quadrature conductivity were measured in 2012 between the contaminated and the non-contaminated areas, despite the presence of biofilms. In the field, the studied hydrocarbon contamination under degradation appears not to modify the capacitive part of conduction, but rather it concerns the ohmic part of conduction. The field and laboratory measurements led us to the conclusion that to choose the most discriminatory and efficient geophysical parameters, it is necessary to have a priori information about the oil (i.e. non-degraded or partially degraded). In the present case study, there is no need to acquire chargeability and phase-lag parameters to locate the contamination in the field, as they do not undergo any change. On the other hand, the resistivity parameter is a good indicator of the presence of partially degraded oil. We also note that normalized chargeability values have been very useful in characterizing the geometry of the clayey-silt roof.

Blondel, Amélie; Schmutz, Myriam; Franceschi, Michel; Tichané, Frédéric; Carles, Margaux

2014-04-01

189

Effects of humic acid on phytodegradation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals.  

PubMed

The use of humic acid (HA) to enhance the efficiency of phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel was evaluated in this study. A sample of soil was artificially contaminated with commercially available diesel fuel to an initial total petroleum hydrocarbons (TPH) concentration of 2300 mg/kg and four heavy metals with concentrations of 400 mg/kg for Pb, 200 mg/kg for Cu, 12 mg/kg for Cd, and 160 mg/kg for Ni. Three plant species, Brassica campestris, Festuca arundinacea, and Helianthus annuus, were selected for the phytodegradation experiment. Percentage degradation of TPH in the soil in a control pot supplemented with HA increased to 45% from 30% without HA. The addition of HA resulted in an increases in the removal of TPH from the soil in pots planted with B. campestris, E arundinacea, and H. annuus, enhancing percentage degradation to 86%, 64%, and 85% from 45%, 54%, and 66%, respectively. The effect of HA was also observed in the degradation of n-alkanes within 30 days. The rates of removal of n-alkanes in soil planted with B. campestris and H. annuus were high for n-alkanes in the range of C11-C28. A dynamic increase in dehydrogenase activity was observed during the last 15 days of a 30-day experimental period in all the pots amended with HA. The enhanced biodegradation performance for TPHs observed might be due to an increase in microbial activities and bioavailable TPH in soils caused by combined effects of plants and HA. The results suggested that HA could act as an enhancing agent for phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel and heavy metals. PMID:22432335

Park, Soyoung; Kim, Ki Seob; Kim, Jeong-Tae; Kang, Daeseok; Sung, Kijune

2011-01-01

190

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

191

Evaluation of electrochemical processes for the removal of several target aromatic hydrocarbons from petroleum contaminated water.  

PubMed

Ground and surface water contamination resulting from the leakage of crude oil and refined petroleum products is a serious and growing environmental problem throughout the world. Consequently, a study of the use of electrochemical treatment in the clean-up was undertaken with the aim of reducing the water contamination by aromatic pollutants to more acceptable levels. In the experiments described, water contamination by refined petroleum products was simulated under laboratory conditions. Electrochemical treatment, using aluminium electrodes, has been optimised by full factorial design and surface response analysis in term of BTEX and PAHs removal and energy consumption. The optimal conditions of pH, current density, electrolysis time, electrolyte type, and electrolyte concentration have then been applied in the treatment of real water samples which were monitored as petroleum contaminated samples. Treatment results have shown that electrochemical methods could achieve the concentration of these pollutants to undetectable levels in particular groundwater and surface water, hence, they can be highly effective in the remediation of water contaminated by aromatic hydrocarbons, and the use of these processes is therefore recommended. PMID:21243149

Alsalka, Yamen; Karabet, François; Hashem, Shahir

2011-03-01

192

Interrelationship of Pyrogenic Polycyclic Aromatic Hydrocarbon (PAH) Contamination in Different Environmental Media.  

PubMed

Interrelationships between pyrogenic polycyclic aromatic hydrocarbons (PAHs) were assessed in air, soil, water, sediment, and tree leaves by using multi-media monitoring data. Concurrent concentration measurements were taken bimonthly for a year for the multi-media at urban and suburban sites. PAH level correlations between air and other media were observed at the urban site but were less clear at the suburban site. Considering a closer PAHs distribution/fate characteristics to soil than suspended solids, contamination in sediment seemed to be governed primarily by that in soil. The partitioning of PAHs in waters could be better accounted for by sorption onto black carbon and dissolved organic carbon. PMID:22303141

Kim, Seung-Kyu; Lee, Dong Soo; Shim, Won Joon; Yim, Un Hyuk; Shin, Yong-Seung

2009-01-01

193

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

194

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...

195

Carbazole angular dioxygenation and mineralization by bacteria isolated from hydrocarbon-contaminated tropical African soil.  

PubMed

Four bacterial strains isolated from hydrocarbon-contaminated soils in Lagos, Nigeria, displayed extensive degradation abilities on carbazole, an N-heterocyclic aromatic hydrocarbon. Physicochemical analyses of the sampling sites (ACPP, MWO, NESU) indicate gross pollution of the soils with a high hydrocarbon content (157,067.9 mg/kg) and presence of heavy metals. Phylogenetic analysis of the four strains indicated that they were identified as Achromobacter sp. strain SL1, Pseudomonas sp. strain SL4, Microbacterium esteraromaticum strain SL6, and Stenotrophomonas maltophilia strain BA. The rates of degradation of carbazole by the four isolates during 30 days of incubation were 0.057, 0.062, 0.036, and 0.050 mg L(-1) h(-1) for strains SL1, SL4, SL6, and BA. Gas chromatographic (GC) analyses of residual carbazole after 30 days of incubation revealed that 81.3, 85, 64.4, and 76 % of 50 mg l(-1) carbazole were degraded by strains SL1, SL4, SL6, and BA, respectively. GC-mass spectrometry and high-performance liquid chromatographic analyses of the extracts from the growing and resting cells of strains SL1, SL4, and SL6 cultured on carbazole showed detection of anthranilic acid and catechol while these metabolites were not detected in strain BA under the same conditions. This study has established for the first time carbazole angular dioxygenation and mineralization by isolates from African environment. PMID:24728574

Salam, L B; Ilori, M O; Amund, O O; Numata, M; Horisaki, T; Nojiri, H

2014-08-01

196

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. PMID:16345270

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

1978-01-01

197

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...

198

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...

199

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

200

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

201

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

2012-10-01

202

Use of radar for nonintrusive subsurface investigations  

SciTech Connect

Finding and mapping buried hazardous waste can be a time-consuming process. However, advances in ground-penetrating radar technology are improving the means by which to detect subsurface features and related contamination. Geophysical Survey Systems, Inc. (North Salem, New Hampshire) has developed an innovative ground-penetrating radar system. The Subsurface Interface Radar (SIR{reg_sign}) system can provide real-time and continuous-profile records that indicate the location and depth of objects within subsurfaces of soil, concrete, rock, water, or other dielectric materials. The SIR{reg_sign} system allows the user to investigate subsurface conditions in a nonintrusive manner; this radar can locate underground storage tanks and buried drums, delineate landfill boundaries and burial trenches, and in some cases, the radar can identify hydrocarbon plums.

NONE

1995-07-01

203

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

204

Groundwater pollution and subsurface sediment contamination in closed MSW landfill, Henchir El Yahoudia  

Microsoft Academic Search

Drilling survey of subsurface geology and groundwater sampling were made at a lakeside of the municipal solid waste (MSW) landfill, Henchir El Yahoudia that is closed in 1999. According to the result of perimeter drilling survey, three aquifers could be recognized below the landfill; 2.0-3.2m, 4.0-6.0m, and 8.5-12.0m in depth. These aquifers were isolated each other using open standpipe piezometer

Mitsuo Yoshida; Abdul Nasser Ibrahim; Jamila Tarhouni; Ahmed Ghrabi

205

Growth kinetics of some subsurface microbial strains using naphthalene as a probe contaminant  

Microsoft Academic Search

The focus of this study is the unravelling of the microbial dynamics of the biodegradation of naphthalene, a polycyclic aromatic hydrocarbon, in an aqueous–sediment matrix. The Pour plate procedure was adopted for the isolation of the microbial colonies, while the sub?culturing of the isolates was based on their cultural (biochemical) and morphological characteristics. Investigations showed that the microbial colonies consisted

C. N. Owabor; S. E. Ogbeide; A. A. Susu

2011-01-01

206

Phytoremediation of petroleum hydrocarbons in tropical coastal soils I. selection of promising woody plants  

Microsoft Academic Search

Goal, Scope and Background  This glasshouse study is aimed at evaluating tropical plants for phytoremediation of petroleum hydrocarbon-contaminated saline\\u000a sandy subsurface soils. Tropical plants were selected for their ability to tolerate high salinity and remove No. 2 diesel\\u000a fuel in coastal topsoil prior to further investigation of the phytoremediation feasibility in deep contaminated soils. The\\u000a residual petroleum-hydrocarbon contaminant at the John

Wenhao H. Sun; Joey B. Lo; Françoise M. Robert; Chittaranjan Ray; Chung-Shih Tang

2004-01-01

207

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

2012-01-01

208

Microbial in situ degradation of aromatic hydrocarbons in a contaminated aquifer monitored by carbon isotope fractionation  

NASA Astrophysics Data System (ADS)

We present an approach for characterizing in situ microbial degradation using the 13C/ 12C isotope fractionation of contaminants as an indicator of biodegradation. The 13C/ 12C isotope fractionation of aromatic hydrocarbons was studied in anoxic laboratory soil percolation columns with toluene or o-xylene as the sole carbon and electron source, and sulfate as electron acceptor. After approximately 2 months' of incubation, the soil microbial community degraded 32 mg toluene l -1 and 44 mg o-xylene l -1 to less than 0.05 mg l -1, generating a stable concentration gradient in the column. The 13C/ 12C isotope ratio in the residual non-degraded fraction of toluene and o-xylene increased significantly, corresponding to isotope fractionation factors (?C) of 1.0015 and 1.0011, respectively. When the extent of biodegradation in the soil column was calculated based on the measured isotope ratios ( Rt) and an isotope fractionation factor (?C=1.0017) obtained from a sulfate-reducing batch culture the theoretical residual substrate concentrations ( Ct) matched the measured toluene concentrations in the column. This indicated that a calculation of biodegradation based on isotope fractionation could work in systems like soil columns. In a field study, a polluted, anoxic aquifer was analyzed for BTEX and PAH contaminants. These compounds were found to exhibit a significant concentration gradient along an 800-m groundwater flow path downstream of the source of contamination. A distinct increase in the carbon isotope ratio ( ?13C) was observed for the residual non-degraded toluene (7.2‰), o-xylene (8.1‰) and naphthalene fractions (1.2‰). Based on the isotope values and the laboratory-derived isotope fractionation factors for toluene and o-xylene, the extent to which the residual substrate fraction in the monitoring wells had been degraded by microorganisms was calculated. The results revealed significant biodegradation along the groundwater flow path. In the wells at the end of the plume, the bioavailable toluene and o-xylene fractions had been almost completely reduced by in situ microbial degradation. Although indane and indene showed decreasing concentrations downstream of the groundwater flow path, suggesting microbial degradation, their carbon isotope ratios remained constant. As the physical properties of these compounds are similar to those of BTEX compounds, the constant isotope values of indane and indene indicated that microbial degradation did not lead to isotope fractionation of all aromatic hydrocarbons. In addition, physical interaction with the aquifer material during the groundwater passage did not significantly alter the carbon isotope composition of aromatic hydrocarbons.

Richnow, Hans H.; Annweiler, Eva; Michaelis, Walter; Meckenstock, Rainer U.

2003-08-01

209

Polycyclic aromatic hydrocarbon contamination and recovery characteristics in some organisms after the Nakhodka oil spill.  

PubMed

Following the oil spill from the Russian tanker Nakhodka in 1997 in the Sea of Japan, polycyclic aromatic hydrocarbons (PAH) were monitored for three years in some molluscs from the Mikuni-cho shore in Japan. Total PAH concentrations in marine organisms except for spiny top shell, ranged from 5.3 to 32.7 ng/g wet weight, but no trends were evident. Total PAH concentration in spiny top shell (Turbo cornutus) was 44 ng/g w.w. in the first month after the oil spill. However, it rapidly decreased to less than 5.4 ng/g w.w. from the second month. Spiny top shell, which was exposed to dietary Nakhodka heavy fuel oil, concentrated benzo(a)pyrene to 17.1 ng/g w.w. after two weeks of exposure and then rapidly eliminated it during an elimination phase. These results suggest that spiny top shell accumulates PAHs because of their low ability to metabolize PAH, but it can excrete parent PAHs rapidly when removed from the source of contamination. Thus it is suitable as an indicator organism in monitoring oil contamination. It can also be inferred from these field and laboratory investigations that, in three years, organisms from the Mikuni-cho shore seem to have adequately recovered from the Nakhodka oil spill contamination. PMID:15556192

Koyama, Jiro; Uno, Seiichi; Kohno, Kumiko

2004-12-01

210

Evaluation of the role of environmental contamination in the microbial degradation of polyaromatic hydrocarbons  

SciTech Connect

Studies were undertaken to determine the effect of environmental contamination upon the potential for degradation of polyaromatic hydrocarbons (PAH) by the microbial populations in freshwater sediments. Naphthalene (NAP), phenanthrene (PHE), and benzo(a)pyrene(BP) were employed as substrates for PAH biodegradation. Biodegradation was assessed by mineralization of the /sup 14/C-PAH substrates incubated in sediment slurries. Mineralization rate constants and substrate turnover times were calculated for PAH mineralization studies. Sediment microcosms treated with individual, unlabeled PAH or a synthetic oil (SO) were sampled for the mineralization assay after various periods of acclimation. NAP and PHE treatments enhanced PAH mineralization rates while BP was inhibitory. The SO treatment caused a substantial enhancement of PAH mineralization rates. A PAH-degrading bacterial population added to various sediment systems did not significantly enhance PAH mineralizaion rates. Studies with natural sediment samples also indicated that previous environmental contamination tends to enhance the potential for PAH biodegradation. Studies indicated PAH mineralization in sediments was related to the length of incubation time, temperature, molecular size of the substrate and prior exposure to PAH or related contaminants.

Sherrill, T.W.

1982-01-01

211

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

212

Geothrix fermentans gen. nov., sp. nov., a novel Fe(III)-reducing bacterium from a hydrocarbon-contaminated aquifer  

Microsoft Academic Search

In an attempt to understand better the micro-organisms involved in anaerobic degradation of aromatic hydrocarbons in the Fe(lll)-reducing zone of petroleum-contaminated aquifers, Fe(lll)-reducing micro-organisms were isolated from contaminated aquifer material that had been adapted for rapid oxidation of toluene coupled to Fe(lll) reduction. One of these organisms, strain H-5T, was enriched and isolated on acetate\\/Fe(lll) medium. Strain H-5T is a

John D. Coates; Debra J. Ellis; Catherine V. Gaw; Derek R. Lovley

213

Ability of cold-tolerant plants to grow in hydrocarbon-contaminated soil.  

PubMed

Phytoremediation of hydrocarbons in soil involves plants and their associated microorganisms. Differences in environmental conditions and restrictions on species importation mean that each country may need to identify indigenous plants to use for phytoremedation. Screening plants for hydrocarbon tolerance before screening for degradation ability may prove more economical than screening directly for degradation. Thirty-nine cold-tolerant plants native, or exotic and naturalized, in western Canada were assessed for their ability to survive in crude oil-contaminated soil. Four naturalized grasses (i.e., Agropyron pectiniforme, Bromus inermis, Phleum pratense, and Poa pratensis), three naturalized legumes (i.e., Medicago sativa, Melilotus officinalis, and Trifolium repens), two native forbs (i.e., Artemisia frigida and Potentilla pensylvanica), one native grass (i.e., Bromus ciliatus) and two native legumes (i.e., Glycyrrhiza lepidota and Psoralea esculenta) exhibited phytoremediation potential, based on survival. We determined the effect of increasing crude oil concentrations on total and root biomass, and relative growth rate of those species with the highest survival. The addition of 0.5%, 1%, and 5% (crude oil wt/fresh soil wt) crude oil to soil significantly decreased both the total biomass by at least 22% of the control and the relative growth rate of all species except P. esculenta. Root biomass significantly decreased by at least 22% with crude oil addition in all species except P. esculenta and A. frigida. Total biomass production in contaminated soil had a significant negative correlation with the relative growth rate in uncontaminated soil. PMID:12929494

Robson, Diana Bizecki; Knight, J Diane; Farrell, Richard E; Germida, James J

2003-01-01

214

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

PubMed Central

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 primers targeting the Sphingomonas 16S rRNA gene combined with denaturing gradient gel electrophoresis (DGGE) was developed to assess Sphingomonas diversity in PAH-contaminated soils. PCR using the new primer pair on a set of template DNAs of different bacterial genera showed that the method was selective for bacteria belonging to the family Sphingomonadaceae. Single-band DGGE profiles were obtained for most Sphingomonas strains tested. Strains belonging to the same species had identical DGGE fingerprints, and in most cases, these fingerprints were typical for one species. Inoculated strains could be detected at a cell concentration of 104 CFU g of soil?1. The analysis of Sphingomonas population structures of several PAH-contaminated soils by the new PCR-DGGE method revealed that soils containing the highest phenanthrene concentrations showed the lowest Sphingomonas diversity. Sequence analysis of cloned PCR products amplified from soil DNA revealed new 16S rRNA gene Sphingomonas sequences significantly different from sequences from known cultivated isolates (i.e., sequences from environmental clones grouped phylogenetically with other environmental clone sequences available on the web and that possibly originated from several potential new species). In conclusion, the newly designed Sphingomonas-specific PCR-DGGE detection technique successfully analyzed the Sphingomonas communities from polluted soils at the species level and revealed different Sphingomonas members not previously detected by culture-dependent detection techniques. PMID:15066784

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

2004-01-01

215

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

216

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

217

A case study of bioremediation of petroleum-hydrocarbon contaminated soil at a crude oil spill site  

Microsoft Academic Search

Laboratory and field pilot studies were carried out on the bioremediation of soil contaminated with petroleum hydrocarbons in the Borhola oil fields, Assam, India. The effects of aeration, nutrients (i.e. nitrogen and phosphorus) and inoculation of extraneous microbial consortia on the bioremediation process were investigated. The beneficial effects of these parameters on the bioremediation rate were realised equally in laboratory

B. K. Gogoi; N. N. Dutta; P. Goswami; T. R. Krishna Mohan

2003-01-01

218

Polycyclic aromatic hydrocarbon contamination of American lobster, Homarus americanus , in the proximity of a coal-coking plant  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental contaminants resulting predominantly from anthropogenic pyrolytic and combustion processes (NRCC 1983). In addition to the usual methods of aerial and aqueous transport to the coastal marine environment substantial amounts of PAH are added through the use of products such as creosote, coal tar and coal tar pitch as preservative and antifouling agents in

J. F. Uthe; C. J. Musial

1986-01-01

219

Chlorinated hydrocarbon contaminants in feces of river otters from the southern Pacific coast of Canada, 1998–2004  

Microsoft Academic Search

Chlorinated hydrocarbon contaminants in coastal river otters (Lontra canadensis) were evaluated by sampling feces (scats) collected on the south coast of British Columbia, Canada. A broad survey of industrialized areas of the Strait of Georgia region was conducted in 1998, and a subsequent survey of working harbours in 2004. Samples from 1998 were analyzed for polychlorinated biphenyls (PCBs), organochlorine (OC)

John E. Elliott; Daniel A. Guertin; Jennifer M. E. Balke

2008-01-01

220

Bioremediation of an aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soil by filamentous fungi isolated from the soil  

Microsoft Academic Search

Twenty-one filamentous fungi were isolated from the soil of an old polycyclic aromatic hydrocarbon (PAH)-contaminated gaswork site and tested in their native soil for PAH degradation. This degradation study was performed for each isolate with two inoculation treatments, by spore or mycelial inoculum. An improvement in the extent of total PAH degradation occurred with mycelial inoculum. The greatest degradation was

Olivier Potin; Catherine Rafin; Etienne Veignie

2004-01-01

221

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

222

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

223

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

SciTech Connect

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 into the surrounding soils. The baseline remediation plan for cleanup of contaminated soils beneath the BGD involves complete removal of the ducts, followed by surveying the underlying and surrounding soils, then removing soil that has been contaminated above cleanup goals. Alternatively, if soil contamination around and beneath the BGD is either non-existent/minimal (below cleanup goals) or is very localized and can be ''surgically removed'' at a reasonable cost, the BGD can be decontaminated and left in place. 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 and to present this data to the stakeholders as part of the Engineering Evaluation/Cost Analysis (EE/CA) process. 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. The tools consisted of a tracer gas leak detection system that was used to define the gaseous leak paths out of the BGD and guide soil characterization studies, a small-footprint Geoprobe to reach areas surrounding the BGD that were difficult to access, two novel, field-deployed, radiological analysis systems (ISOCS and BetaScint) and a three-dimensional (3D) visualization system to facilitate data analysis/interpretation. 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 implementing this approach.

Sullivan, T.; Heiser, J.; Kalb, P.; Milian, L.; Newson, C.; Lilimpakas, M.; Daniels, T.

2002-02-26

224

Remediation trials for hydrocarbon-contaminated sludge from a soil washing process: evaluation of bioremediation technologies.  

PubMed

The usual fate of highly contaminated fine products (silt-clay fractions) from soil washing plants is disposal in a dump or thermal destruction (organic contaminants), with consequent environmental impacts. Alternative treatments for these fractions with the aim of on-site reuse are needed. Therefore, the feasibility of two technologies, slurry bioremediation and landfarming, has been studied for the treatment of sludge samples with a total petroleum hydrocarbon (TPH) content of 2243 mg/kg collected from a soil washing plant. The treatability studies were performed at the laboratory and pilot-real scales. The bioslurry assays yielded a TPH reduction efficiency of 57% and 65% in 28 days at the laboratory and pilot scale, respectively. In the landfarming assays, a TPH reduction of 85% in six months was obtained at laboratory scale and 42% in three months for the bioremediation performed in the full-scale. The efficiency of these processes was evaluated by ecotoxicity assessments. The toxic effects in the initial sludge sample were very low for most measured parameters. After the remediation treatments, a decrease in toxic effects was observed in earthworm survival and in carbon mineralisation. The results showed the applicability of two well known bioremediation technologies on these residues, this being a novelty. PMID:22118850

Frutos, F J García; Pérez, R; Escolano, O; Rubio, A; Gimeno, A; Fernandez, M D; Carbonell, G; Perucha, C; Laguna, J

2012-01-15

225

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

226

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...

227

ANNUAL 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

Research is investigating mineralogic and geochemical factors controlling the desorption rate of 137Cs+ from subsurface sediments on the Hanford Site contaminated with different types of high-level waste. The project will develop kinetic data and models that describe the release ...

228

Improved management of winter operations to limit subsurface contamination with degradable deicing chemicals in cold regions.  

PubMed

This paper gives an overview of management considerations required for better control of deicing chemicals in the unsaturated zone at sites with winter maintenance operations in cold regions. Degradable organic deicing chemicals are the main focus. The importance of the heterogeneity of both the infiltration process, due to frozen ground and snow melt including the contact between the melting snow cover and the soil, and unsaturated flow is emphasised. In this paper, the applicability of geophysical methods for characterising soil heterogeneity is considered, aimed at modelling and monitoring changes in contamination. To deal with heterogeneity, a stochastic modelling framework may be appropriate, emphasizing the more robust spatial and temporal moments. Examples of a combination of different field techniques for measuring subsoil properties and monitoring contaminants and integration through transport modelling are provided by the SoilCAM project and previous work. Commonly, the results of flow and contaminant fate modelling are quite detailed and complex and require post-processing before communication and advising stakeholders. The managers' perspectives with respect to monitoring strategies and challenges still unresolved have been analysed with basis in experience with research collaboration with one of the case study sites, Oslo airport, Gardermoen, Norway. Both scientific challenges of monitoring subsoil contaminants in cold regions and the effective interaction between investigators and management are illustrated. PMID:24281673

French, Helen K; van der Zee, Sjoerd E A T M

2014-08-01

229

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

230

Coupling Between Flow and Precipitation in Heterogeneous Subsurface Environments and Effects On Contaminant Fate and Transport  

SciTech Connect

Reactive mixing fronts can occur at large scales, e.g. when chemical amendments are injected in wells, or at small scales (pore-scales) when reactive intermediates are being generated in situ at grain boundaries, cell surfaces and adjacent to biofilms. The product of the reactions such as mineral precipitates, biofilms or filtered colloids modifies permeability leading to the complex coupling between flow and reactions and precipitation. The objectives are to determine how precipitates are distributed within large and small scale mixing fronts, how permeability and flow is modified by precipitation, how the mobility of a representative contaminant, strontium, is affected by the precipitation of carbonates, and how subsequent dissolution of the carbonates result in mobilization of Sr and increased flow. The desired outcomes of the project are to help develop methods leading to sequestration of metal contaminants, and to determine how macroscopic field-scale modeling can be applied to predict the outcome of remediation activities.

Tartakovsky, Alexandre M.; Redden, George D.; Yoshiko Fujita; Scheibe, Tim; Smith, Robert; Reddy, Michael; Kelly, Shelly

2006-06-01

231

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

232

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 slab-on-grade building found at a site contaminated with gasoline. Although the high VOC concentrations (30-60 g m³) 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

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

1995-01-01

233

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) PMID:1903628

Aelion, C M; Bradley, P M

1991-01-01

234

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

235

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. PMID:9758812

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

1998-01-01

236

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

USGS Publications Warehouse

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

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

1998-01-01

237

[Contamination and source of polycyclic aromatic hydrocarbons in epikarst spring water].  

PubMed

The water samples were collected from four typical epikarst springs in Nanchuan District, Chongqing Municipality between October 2010 and October 2011. Sixteen priority polycyclic aromatic hydrocarbons in epikarst spring waters were quantitatively analyzed by the gas chromatography-mass spectrometer (GC-MS). The objectives of this study were to investigate the seasonal variations of polycyclic aromatic hydrocarbons' concentration, composition, source and contamination characterization in epikarst springs water. The results showed that the detection ratios of 16 PAHs in four springs were 100%. The total concentrations of 16 PAHs fluctuated greatly in epikarst spring water during one year observation, and the concentration ranged from 341 to 4 968 ng x L(-1), with a mean value of 1772 ng x L(-1). The total concentrations of 7 carcinogenic PAHs in rain season were all higher than those in dry season in four epikarst springs. The PAHs profiles were dominated by (2-3) rings PAHs in spring water, which accounted for more than 50% of 16 PAHs. The PAHs in spring water mainly originated from the combustion of coal, biomass and petroleum, and during June to October 2011, PAHs originated from the combustion of coal and biomass had a larger contribution. The ratios of Ant/( Ant + Phe) and Fla/( Fla + Pyr) changing with seasons showed that Ant, Phe, Fla and Pyr were easy to migrate in epikarst soils. In 4 isomeric ratios, the ratios of Fla/(Fla + Pyr) were more sensitive to reflect the information of sources. Compared to other areas in the world, the concentration of 16 PAHs in epikarst spring water is at a higher level, which shows the epikarst spring water has been suffered the PAHs pollution. PMID:25158482

Sun, Yu-Chuan; Shen, Li-Cheng; Yuan, Dao-Xian

2014-06-01

238

Assessment of degradation pathways in an aquifer with mixed chlorinated hydrocarbon contamination using stable isotope analysis.  

PubMed

The demonstration of monitored natural attenuation (MNA) of chlorinated hydrocarbons in groundwater is typically conducted through the evaluation of concentration trends and parent-daughter product relationships along prevailing groundwater flow paths. Unfortunately, at sites contaminated by mixtures of chlorinated ethenes, ethanes, and methanes, the evaluation of MNA by using solely concentration data and parent-daughter relationships can result in erroneous conclusions regarding the degradation mechanisms that are truly active at the site, since many of the daughter products can be derived from multiple parent compounds. Stable carbon isotope analysis was used, in conjunction with concentration data, to clarify and confirm the active degradation pathways at a former waste solvent disposal site where at least 14 different chlorinated hydrocarbons have been detected in the groundwater. The isotope data indicate that TCE, initially believed to be present as a disposed product and/or a PCE dechlorination intermediate, is attributable to dehydrochlorination of 1,1,2,2-PCA. The isotope data further support that vinyl chloride and ethene in the site groundwater result from dichloroelimination of 1,1,2-trichlorethane and 1,2-dichloroethane, respectively, rather than from reductive dechlorination of the chlorinated ethenes PCE, TCE, or 1,2-DCE. The isotope data confirm that the chlorinated ethanes and chlorinated methanes are undergoing significant intrinsic degradation, whereas degradation of the chlorinated ethenes may be limited. In addition to the classical trend of enriched isotope values of the parent compounds with increasing distance associated to biodegradation, shifts of isotope ratios of degradation byproduct in the opposite direction due to mixing of isotopically light byproducts of biodegradation with compounds from the source are shown to be of high diagnostic value. These data underline the value of stable isotope analysis in confirming transformation processes at sites with complex mixtures of chlorinated compounds. PMID:16173553

Hunkeler, Daniel; Aravena, Ramon; Berry-Spark, Karen; Cox, Evan

2005-08-15

239

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

240

Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516  

SciTech Connect

Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors)

McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W. [S M Stoller Corporation, 2439 Robertson Drive, Richland, WA 99354 (United States)] [S M Stoller Corporation, 2439 Robertson Drive, Richland, WA 99354 (United States)

2013-07-01

241

Biodegradation of organic contaminants in subsurface systems: Kinetic and metabolic considerations  

SciTech Connect

Groundwater contaminated by organic chemicals from industrial spills, leaking underground gasoline storage tanks and landfills has caused concern about the future of a major source of drinking water. A potential alternative to expensive groundwater reclamation projects is the use of natural soil bacteria to degrade organic contaminants. This study was designed to measure the kinetic response of tertiary butyl alcohol (TBA), determine the biological degradation rates of methanol, ethanol, propanol, l-butanol, TBA, pentanol, phenol and 2,4-dichlorophenol; describe site specific conditions which enhance or inhibit degradation and compare biodegradation rates with thermodynamic predictions. Each of the test compounds except TBA was readily degraded in the Blacksburg soil. Inhibition of sulfate reduction by the addition of molybdate stimulated degradation of all compounds including TBA, whereas, inhibition of methanogenesis with BESA slowed the degradation rates. The addition of nitrate did not affect the biodegradation in Blacksburg soil. In the Newport News soil, all of the test compounds were biodegraded at substantially higher rates than was observed in the Blacksburg soil. The presence of the metabolic inhibitors did not affect degradation, however, the addition of nitrate increased the degradation rates of the alcohols but not the phenols. The degradation rates in each of the soils did not correlate with the bacterial population size or free energies of the reactions.

Morris, M.S.

1988-01-01

242

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

243

Properties of hydrocarbon- and salt-contaminated flare pit soils in northeastern British Columbia (Canada).  

PubMed

Many contaminated sites in Canada are associated with flare pits generated during past petroleum extraction operations. Flare pits are located adjacent to well sites, compressor stations and batteries and are often subjected to the disposal of wastes from the flaring of gas, liquid hydrocarbons and brine water. This study was conducted to evaluate the physical, chemical, electrical and mineral properties of three flare pit soils as compared to adjacent control soils. Results showed that particle size distribution, pH, total N, cation exchange capacity, exchangeable Mg(2+), and sodium adsorption ratio were similar in soils from flare pits and control sites. Total C, exchangeable Ca(2+), K(+) and Na(+), soluble Ca(2+), Mg(2+), K(+) and Na(+) and electrical conductivity were higher in flare pit soils compared to control soils. X-ray diffraction and scanning electron microscopic analyses showed the presence of gypsum [CaSO(4).2H(2)O], dolomite [CaMg(CO(3))(2)], pyrite [FeS(2)], jarosite [KFe(3)(OH)(6)(SO(4))(2)], magnesium sulphate, oxides of copper and iron+copper in salt efflorescence observed in flare pit soils. Soils from both flare pits and control sites contained mica, kaolonite and 2:1 expanding clays. The salt-rich materials altered the ionic equilibria in the flare pit soils; K(Mg-Ca) selectivity coefficients in control soils were higher compared to contaminated soils. The properties of soils (e.g., high electrical conductivity) affected by inputs associated with oil and gas operations might render flare pit soils less conducive to the establishment and growth of common agricultural crops and forest trees. PMID:15950049

Arocena, J M; Rutherford, P M

2005-07-01

244

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

2013-01-01

245

In situ detection of anaerobic alkane metabolites in subsurface environments  

PubMed Central

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.

2013-01-01

246

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

2013-06-15

247

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

2013-10-15

248

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

PubMed

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. PMID:21369833

Singleton, David R; Richardson, Stephen D; Aitken, Michael D

2011-11-01

249

Evaluation of landfarm remediation of hydrocarbon-contaminated soil at the Inveresk Railyard, Launceston, Australia  

SciTech Connect

The cost of landfarm bioremediation of hydrocarbon-contaminated soil at a disused railyard site in Tasmania, Australia is reported. The landfarm area was enclosed in an impermeable clay embankment and where necessary the base was also rolled with clay. Microbial inoculation was not deemed to be necessary since suitable degrading biota were found to be present in site samples prior to commencement of the landfarming. Fertilizer amendment comprised primarily ammonium sulphate and superphosphate to give a C:N ratio (TPH:fertilizer) of 28:1 and a C:P ratio of 200:1. The soil was turned regularly and watered as required for the 12-month duration of the operation. Over this period levels of TPH showed a linear decline from a mean of 4,644 mg/kg to near 100 mg/kg or less, with greatest losses being in the chain lengths C10-C28. The cost was determined to be $A13.40c per m{sup 3}, which is at the lower end of the spectrum of reported landfarming costs. The cost of such operations is important since the reported economics will influence others` choice of bioremediation techniques.

Line, M.A.; Garland, C.D. [Univ. of Tasmania, Hobart (Australia)] [Univ. of Tasmania, Hobart (Australia); Crowley, M. [Stephenson EMF Consultants, Hobart (Australia)] [Stephenson EMF Consultants, Hobart (Australia)

1996-12-31

250

Biostimulation Reveals Functional Redundancy of Anthracene-Degrading Bacteria in Polycyclic Aromatic Hydrocarbon-Contaminated Soil  

PubMed Central

Abstract Stable-isotope probing was previously used to identify bacterial anthracene-degraders in untreated soil from a former manufactured gas plant site. However, subsequent pyrosequence analyses of total bacterial communities and quantification of 16S rRNA genes indicated that relative abundances of the predominant anthracene-degrading bacteria (designated Anthracene Group 1) diminished as a result of biological treatment conditions in lab-scale, aerobic bioreactors. This study identified Alphaproteobacterial anthracene-degrading bacteria in bioreactor-treated soil which were dissimilar to those previously identified. The largest group of sequences was from the Alterythrobacter genus while other groups of sequences were associated with bacteria within the order Rhizobiales and the genus Bradyrhizobium. Conditions in the bioreactor enriched for organisms capable of degrading anthracene which were not the same as those identified as dominant degraders in the untreated soil. Further, these data suggest that identification of polycyclic aromatic hydrocarbon-degrading bacteria in contaminated but untreated soil may be a poor indicator of the most active degraders during biological treatment. PMID:24302851

Dunlevy, Sage R.; Singleton, David R.; Aitken, Michael D.

2013-01-01

251

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

252

Characterization of culturable heterotrophic bacteria in hydrocarbon-contaminated soil from an alpine former military site.  

PubMed

We characterized the culturable, heterotrophic bacterial community in soil collected from a former alpine military site contaminated with petroleum hydrocarbons. The physiologically active eubacterial community, as revealed by fluorescence-in situ-hybridization, accounted for 14.9 % of the total (DAPI-stained) bacterial community. 4.0 and 1.2 % of the DAPI-stained cells could be attributed to culturable, heterotrophic bacteria able to grow at 20 and 10 °C, respectively. The majority of culturable bacterial isolates (23/28 strains) belonged to the Proteobacteria with a predominance of Alphaproteobacteria. The remaining isolates were affiliated with the Firmicutes, Actinobacteria and Bacteroidetes. Five strains could be identified as representatives of novel species. Characterization of the 28 strains demonstrated their adaptation to the temperature and nutrient conditions prevailing in the studied soil. One-third of the strains was able to grow at subzero temperatures (-5 °C). Studies on the effect of temperature on growth and lipase production with two selected strains demonstrated their low-temperature adaptation. PMID:24402300

Zhang, Dechao; Margesin, Rosa

2014-06-01

253

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. PMID:21369833

Richardson, Stephen D.; Aitken, Michael D.

2011-01-01

254

Pilot-scale bioremediation of a petroleum hydrocarbon-contaminated clayey soil from a sub-Arctic site.  

PubMed

Bioremediation is a potentially cost-effective solution for petroleum contamination in cold region sites. This study investigates the extent of biodegradation of petroleum hydrocarbons (C16-C34) in a pilot-scale biopile experiment conducted at 15°C for periods up to 385 days, with a clayey soil, from a crude oil-impacted site in northern Canada. Although several studies on bioremediation of petroleum hydrocarbon-contaminated soils from cold region sites have been reported for coarse-textured, sandy soils, there are limited studies of bioremediation of petroleum contamination in fine-textured, clayey soils. Our results indicate that aeration and moisture addition was sufficient for achieving 47% biodegradation and an endpoint of 530mg/kg for non-volatile (C16-C34) petroleum hydrocarbons. Nutrient amendment with 95mg-N/kg showed no significant effect on biodegradation compared to a control system without nutrient but similar moisture content. In contrast, in a biopile amended with 1340 mg-N/kg, no statistically significant biodegradation of non-volatile fraction was detected. Terminal Restriction Fragment Length Polymorphism (T-RFLP) analyses of alkB and 16S rRNA genes revealed that inhibition of hydrocarbon biodegradation was associated with a lack of change in microbial community composition. Overall, our data suggests that biopiles are feasible for attaining the bioremediation endpoint in clayey soils. Despite the significantly lower biodegradation rate of 0.009day(-1) in biopile tank compared to 0.11day(-1) in slurry bioreactors for C16-C34 hydrocarbons, the biodegradation extents for this fraction were comparable in these two systems. PMID:25218258

Akbari, Ali; Ghoshal, Subhasis

2014-09-15

255

Considerations for robust compositional simulations of subsurface nonaqueous phase liquid contamination and remediation  

SciTech Connect

A nonisothermal compositional model has been developed for examining nonaqueous phase liquid contamination and remediation scenarios. The governing mass balance equations and constraints have been presented, and various type of compositional formulations available have been examined. An efficient and robust formulation has been developed that addressed certain issues related to groundwater situations and overcomes numerical difficulties encountered with previous formulations. The proposed formulation collapses to that corresponding to the multiphase flow equation set when interface mass transfer is neglected. Numerical implementation of the formulation has been discussed, and example problems have been presented for benchmark and verification. The present formulation outperforms other currently used formulations for the isothermal case studied and performs at least as well as its counterparts for the nonisothermal case. Characteristics of the simulator that hinder convergence for difficult problems have been identified, and directions for even further improvements have been noted. 30 refs., 8 figs., 3 tabs.

Panday, S.; Wu, Y.S.; Huyakorn, P.S. [HydroGeoLogic, Inc., Herndon, VA (United States)] [HydroGeoLogic, Inc., Herndon, VA (United States); Forsyth, P.A. [Univ. of Waterloo, Ontario (Canada)] [Univ. of Waterloo, Ontario (Canada); Falta, R.W. [Clemson Univ., SC (United States)] [Clemson Univ., SC (United States)

1995-05-01

256

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

257

Distribution of petroleum hydrocarbons and organochlorinated contaminants in marine biota and coastal sediments from the ROPME Sea Area during 2005.  

PubMed

The composition and spatial distribution of various petroleum hydrocarbons (PHs), comprising both aliphatic and polycyclic aromatic hydrocarbons (PAHs), and selected chlorinated pesticides and PCBs were measured in biota and coastal sediments from seven countries in the Persian Gulf and the Gulf of Oman (Bahrain, Iran, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates). Evidence of extensive marine contamination with respect to organochlorinated compounds and PHs was not observed. Only one site, namely the BAPCO oil refinery in Bahrain, was considered to be chronically contaminated. Comparison of the results from this survey for ? DDTs and ? PCBs in rock oysters from the Gulf of Oman with similar measurements made at the same locations over the past two decades indicates a temporal trend of overall decreasing ? PCB concentrations in oysters, whereas ? DDTs levels have little changed during that period. PMID:20965523

de Mora, Stephen; Tolosa, Imma; Fowler, Scott W; Villeneuve, Jean-Pierre; Cassi, Roberto; Cattini, Chantal

2010-12-01

258

Anaerobic hydrocarbon degradation in petroleum-contaminated harbor sediments under sulfate-reducing and artificially imposed iron-reducing conditions  

USGS Publications Warehouse

The potential use of iron(III) oxide to stimulate in-situ hydrocarbon degradation in anaerobic petroleum-contaminated harbor sediments was investigated. Previous studies have indicated that Fe(III)-reducing bacteria (FeRB) can oxidize some electron donors more effectively than sulfate- reducing bacteria (SRB). In contrast to previous results in freshwater sediments, the addition of Fe(III) to marine sediments from San Diego Bay, CA did not switch the terminal electron-accepting process (TEAP) from sulfate reduction to Fe-(III) reduction. Addition of Fe(III) also did not stimulate anaerobic hydrocarbon oxidation. Exposure of the sediment to air [to reoxidize Fe(II) to Fe(III)] followed by anaerobic incubation of the sediments, resulted in Fe-(III) reduction as the TEAP, but contaminant degradation was not stimulated and in some instances was inhibited. The difference in the ability of FeRB to compete with the SRB in the different sediment treatments was related to relative population sizes. Although the addition of Fe(III) did not stimulate hydrocarbon degradation, the results presented here as well as other recent studies demonstrate that there may be significant anaerobic hydrocarbon degradation under sulfate-reducing conditions in harbor sediments.

Coates, J.D.; Anderson, R.T.; Woodward, J.C.; Phillips, E.J.P.; Lovley, D.R.

1996-01-01

259

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

NASA Astrophysics Data System (ADS)

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

Vodyanitskii, Yu. N.

2014-02-01

260

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

2011-07-01

261

Environmental Analysis of Endocrine Disrupting Effects from Hydrocarbon Contaminants in the Ecosystem  

SciTech Connect

This annual report summarizes the progress of three years of a three-year grant awarded to the Center for Bioenvironmental Research (CBR) at Tulane and Xavier Universities. The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones in different species present in aquatic ecosystems. The three major areas of research include (1) a biotechnology based screening system to identify potential hormone mimics and antagonists; (2) an animal screening system to identify biomarkers of endocrine effects; and (3) a literature review to identify compounds at various DOE sites that are potential endocrine disruptors. Species of particular focus in this study 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 human inhabitants. The focus of the literature research was to provide an analysis of the contaminants located on or around various Department of Energy (DOE) sites that are or have the potential to function as endocrine disruptors and to correlate the need for studying endocrine disruptors to DOE's programmatic needs. Previous research within the Center for Bioenvironmental Research at Tulane and Xavier Universities has focused on understanding the effects of environmental agents on the human and wildlife health and disease. In particular this research has focused on how exogenous agents can function to mimic or disrupt normal endocrine signaling, i.e. estrogen, thyroid within various systems from whole animal studies with fish, amphibians and insects to human cancer cell lines. Significant work has focused on the estrogenic and anti-estrogenic action of both synthetic organochlorine chemicals and naturally produced phytochemicals. Recent projects have extended these research objectives to examination of these environmental agents on the symbiotic relationship between nitrogen fixing rhizobial bacteria and leguminous plants. This research will form the foundation for future experiments into the genetic manipulation of plants to potentially promote greater or more specific symbiotic relationships between plant and Rhizobium allowing this biological phenomenon to be used in a greater number of crop types. Future technology developments could include the genetic engineering of crops suitable for in situ vadose zone 2 bioremediation (via microbes) and phytoremediation (through the crop, itself) in contaminated DOE sites.

McLachlan, John A.

2000-06-01

262

Two- and Three-Dimensional Depiction of Subsurface Geology Using Commercial Software for Support of Groundwater Contaminant Fate and Transport Analysis - 13345  

SciTech Connect

Groundwater contamination by hexavalent chromium and other nuclear reactor operation-related contaminants has resulted in the need for groundwater remedial actions within the Hanford Site reactor areas (the Hanford Site 100 Area). The large geographic extent of the resultant contaminant plumes requires an extensive level of understanding of the aquifer structure, characteristics, and configuration to support assessment and design of remedial alternatives within the former 100-D, 100-H, and 100-K reactor areas. The authors have prepared two- and three-dimensional depictions of the key subsurface geologic structures at two Hanford Site reactor operable units (100-K and 100-D/H). These depictions, prepared using commercial-off-the-shelf (COTS) visualization software, provide a basis for expanding the understanding of groundwater contaminant migration pathways, including identification of geologically-defined preferential groundwater flow pathways. These identified preferential flow pathways support the conceptual site model and help explain both historical and current contaminant distribution and transport. (authors)

Ivarson, Kristine A. [North Wind, Inc. Richland, Washington 99352 (United States)] [North Wind, Inc. Richland, Washington 99352 (United States); Miller, Charles W.; Arola, Craig C. [CH2M HILL Plateau Remediation Company, Richland, Washington 99352 (United States)] [CH2M HILL Plateau Remediation Company, Richland, Washington 99352 (United States)

2013-07-01

263

The prediction of the effectiveness of interceptor trenches in the remediation of ground-water contamination by petroleum hydrocarbons  

E-print Network

is unknown; and therefore, it was not possible to calculate the hydraulic conductivity based upon the transmissivity. Contamination of the ground water is by gasoline, which exists in two phases: a free-floating separate phase, and a dissolved phase... system, although values for hydraulic conductivity were estimated and had to be increased in order to simulate flow to the interceptor trench. The failure of the interceptor trench system at Site C to recover liquid hydrocarbons serves to make apparent...

Mast, Mary Katherine

2012-06-07

264

Solid culture amended with small amounts of raw coffee beans for the removal of petroleum hydrocarbon from weathered contaminated soil  

Microsoft Academic Search

Solid culture with small amounts of low-quality raw coffee beans was used for total petroleum hydrocarbon (TPH) removal from a weathered and polluted soil. Soil contaminated with 58 000mgkg?1 of TPH was treated with soil:coffee bean ratios of 98:2, 96:4, 94:6, and 92:8, at a C:N:P ratio of 100:10:1, 20% humidity, and 28°C, for periods of 15, 60, and 90

Adriana Roldán-Martín; Graciano Calva-Calva; Norma Rojas-Avelizapa; Ma. Dolores Díaz-Cervantes; Refugio Rodríguez-Vázquez

2007-01-01

265

Culture Independent Detection of Sphingomonas sp. EPA 505 Related Strains in Soils Contaminated with Polycyclic Aromatic Hydrocarbons (PAHs)  

Microsoft Academic Search

The Sphingomonas genus hosts many interesting pollutant-degrading strains. Sphingomonas sp. EPA505 is the best studied polycyclic aromatic hydrocarbon (PAH)-degrading Sphingomonas strain. Based on 16S rRNA gene sequence analysis, Sphingomonas sp. strain EPA505 forms a separate branch in the Sphingomonas phylogenetic tree grouping exclusively PAH-degrading isolates. For specific PCR detection and monitoring of Sphingomonas sp. EPA505 and related strains in PAH-contaminated

N. M. Leys; A. Ryngaert; L. Bastiaens; E. M. Top; W. Verstraete; D. Springael

2005-01-01

266

Microbial metabolism and community structure in response to bioelectrochemically enhanced remediation of petroleum hydrocarbon-contaminated soil.  

PubMed

This study demonstrates that electrodes in a bioelectrochemical system (BES) can potentially serve as a nonexhaustible electron acceptor for in situ bioremediation of hydrocarbon contaminated soil. The deployment of BES not only eliminates aeration or supplement of electron acceptors as in contemporary bioremediation but also significantly shortens the remediation period and produces sustainable electricity. More interestingly, the study reveals that microbial metabolism and community structure distinctively respond to the bioelectrochemically enhanced remediation. Tubular BESs with carbon cloth anode (CCA) or biochar anode (BCA) were inserted into raw water saturated soils containing petroleum hydrocarbons for enhancing in situ remediation. Results show that total petroleum hydrocarbon (TPH) removal rate almost doubled in soils close to the anode (63.5-78.7%) than that in the open circuit positive controls (37.6-43.4%) during a period of 64 days. The maximum current density from the BESs ranged from 73 to 86 mA/m(2). Comprehensive microbial and chemical characterizations and statistical analyses show that the residual TPH has a strongly positive correlation with hydrocarbon-degrading microorganisms (HDM) numbers, dehydrogenase activity, and lipase activity and a negative correlation with soil pH, conductivity, and catalase activity. Distinctive microbial communities were identified at the anode, in soil with electrodes, and soil without electrodes. Uncommon electrochemically active bacteria capable of hydrocarbon degradation such as Comamonas testosteroni, Pseudomonas putida, and Ochrobactrum anthropi were selectively enriched on the anode, while hydrocarbon oxidizing bacteria were dominant in soil samples. Results from genus or phylum level characterizations well agree with the data from cluster analysis. Data from this study suggests that a unique constitution of microbial communities may play a key role in BES enhancement of petroleum hydrocarbons biodegradation in soils. PMID:24628095

Lu, Lu; Huggins, Tyler; Jin, Song; Zuo, Yi; Ren, Zhiyong Jason

2014-04-01

267

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

268

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

269

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

SciTech Connect

'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 human inhabitants. This reports the progress of 1.5 years of a three-year grant awarded to the Tulane/Xavier Center for Bioenvironmental Research (CBR). A growing body of evidence suggests that chemicals in the environment can disrupt the endocrine system of animals (i.e., wildlife and humans) and adversely impact the development of these species. Because of the multitude of known endocrine-disrupting chemicals and the numerous industrial and government sectors producing these chemicals, almost every federal agency has initiated research on the endocrine effects of chemicals relevant to their operations. This study represents the Department of Energy (DOE) Basic Energy Sciences'' only research on the impacts of endocrine-disrupting chemicals. The activities employed by this project to determine these impacts include development of biotechnology screens (in vitro), animal screens (in vivo), and other analyses of aquatic ecosystem biomarkers of exposure. The results from this study can elucidate how chemicals in the environment, including those from DOE activities, can signal (and alter) the development of a number of species in aquatic ecosystems. These signals can have detrimental impacts not only on an organismal level, but also on community, population, and entire ecosystem levels, including humans.'

McLachlan, J.

1998-06-01

270

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

2013-04-15

271

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

272

Biomarker sensitivity for polynuclear aromatic hydrocarbon contamination in two marine fish species collected in Galveston Bay, Texas  

SciTech Connect

The Galveston Bay estuary exhibited a contamination gradient for polynuclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons, and the comparative sensitivity of various biomarkers in fish from different bay locations were determined. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), were collected from four stations where sediment total PAHs ranged from 68 > 1,000 ng/g. The induction of cytochrome P4501A-(CYP1A)-dependent hepatic ethoxyresorufin-O-deethylase (EROD) activity, CYPIA mRNA levels, or CYPIA immunoreactive protein in hardhead catfish was highly variable in the field-collected fish and in fish dosed with up to 15 mg/kg benzo[a]pyrene (BaP). In contrast, significant differences were seen in biliary concentrations of naphthalene, phenanthrene, and BaP metabolites in hardhead catfish from polluted versus less polluted areas. In croakers taken from the same four Galveston Bay locations, EROD and glutathione S-transferase activities, immunoreactive CYP1A protein, biliary PAH metabolites, and PAH-DNA adducts were higher at the contaminated stations compared with less polluted locations. These studies suggest that the croaker is a good species for monitoring contaminants that induce CYP1A-mediated responses. Biliary PAH metabolites and PAH-DNA adducts were also sensitive indicators of exposure to PAH contamination in both species of fish.

Willett, K.L.; Steinberg, M.A.; Safe, S.H. [Texas A and M Univ., College Station, TX (United States). Veterinary Physiology and Pharmacology; McDonald, S.J.; Beatty, K.B.; Kennicutt, M.C. [Geochemical and Environmental Research Group, College Station, TX (United States)

1997-07-01

273

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

274

Ability of Cold-Tolerant Plants to Grow in Hydrocarbon-Contaminated Soil  

Microsoft Academic Search

Phytoremediation of hydrocarbons in soil involves plants and their associated microorganisms. Differences in environmental conditions and restrictions on species importation mean that each country may need to identify indigenous plants to use for phytoremediation. Screening plants for hydrocarbon tolerance before screening for degradation ability may prove more economical than screening directly for degradation. Thirty-nine cold-tolerant plants native, or exotic and

Diana Bizecki Robson; J. Diane Knight; Richard E. Farrell; James J. Germida

2003-01-01

275

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 ...

276

Enrichment and partitioning of polycyclic aromatic hydrocarbons in the sea surface microlayer and subsurface water along the coast of Xiamen Island, China.  

PubMed

Sea microlayer (SML) and subsurface water (SSW) samples were collected around Xiamen Island to study the enrichment and partitioning of polycyclic aromatic hydrocarbons (PAHs). Total PAH concentrations ranged from 93.43 to 411.05 ng L(-1) in the SML and 49.29-279.42 ng L(-1) in the SSW. Compared with the results of previous studies before pollution control measurements, PAHs levels decreased significantly. The enrichment factors (EFs) of dissolved and particulate PAHs varied from 0.68 to 2.71 and 0.43-3.56. EFs showed the consistent enrichment trends with sites and exhibited different enrichment characteristics between 2 and 3 ring PAHs and 4 ring PAHs. Furthermore, the much higher concentrations of BaP (strong carcinogenicity) were accompanied by higher EFs in the SML samples from the Western Xiamen Harbour, which together indicated the risk of impacts to the fish eggs that usually float on the SML water after exposure to oil spills and combustion, contributed directly by the port and shipping activities. PMID:24274953

Ya, Miao-Lei; Wang, Xin-Hong; Wu, Yu-Ling; Ye, Cui-Xing; Li, Yong-Yu

2014-01-15

277

Clonal Variation in Survival and Growth of Hybrid Poplar and Willow in an IN SITU Trial on Soils Heavily Contaminated with Petroleum Hydrocarbons  

Microsoft Academic Search

Species and hybrids between species belonging to the genera Populus (poplar) and Salix (willow) have been used successfully for phytoremediation of contaminated soils. Our objectives were to: 1) evaluate the potential for establishing genotypes of poplar and willow on soils heavily contaminated with petroleum hydrocarbons and 2) identify promising genotypes for potential use in future systems. We evaluated height, diameter,

Ronald S. Zalesny Jr; Edmund O. Bauer; Richard B. Hall; Jill A. Zalesny; Joshua Kunzman; Chris J. Rog; Don E. Riemenschneider

2005-01-01

278

Role of environmental fluctuations and microbial diversity in degradation of hydrocarbons in contaminated sludge.  

PubMed

Little is known about microbial communities involved in hydrocarbon degradation, whether it be their structural and functional diversity or their response to environmental constraints such as oxygen fluctuation. Here, current knowledge of the impact of diversity and redox oscillations upon ecosystem processes is reviewed. In addition, we present the main conclusions of our studies in this field. Oxic/anoxic oscillations had a strong impact upon bacterial community structures, influencing their ability to degrade hydrocarbons and their capacity to reduce hydrocarbon toxicity. Furthermore, a decrease in functional diversity has a strong impact on pollutant degradation. PMID:21530651

Cravo-Laureau, Cristiana; Hernandez-Raquet, Guillermina; Vitte, Isabelle; Jézéquel, Ronan; Bellet, Virginie; Godon, Jean-Jacques; Caumette, Pierre; Balaguer, Patrick; Duran, Robert

2011-11-01

279

Assessment of diesel contamination in groundwater using electromagnetic induction geophysical techniques.  

PubMed

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. PMID:18393065

Jin, Song; Fallgren, Paul; Cooper, Jeffrey; Morris, Jeffrey; Urynowicz, Michael

2008-05-01

280

Linkage between bacterial and fungal rhizosphere communities in hydrocarbon-contaminated soils is related to plant phylogeny.  

PubMed

Phytoremediation is an attractive alternative to excavating and chemically treating contaminated soils. Certain plants can directly bioremediate by sequestering and/or transforming pollutants, but plants may also enhance bioremediation by promoting contaminant-degrading microorganisms in soils. In this study, we used high-throughput sequencing of bacterial 16S rRNA genes and the fungal internal transcribed spacer (ITS) region to compare the community composition of 66 soil samples from the rhizosphere of planted willows (Salix spp.) and six unplanted control samples at the site of a former petrochemical plant. The Bray-Curtis distance between bacterial communities across willow cultivars was significantly correlated with the distance between fungal communities in uncontaminated and moderately contaminated soils but not in highly contaminated (HC) soils (>2000?mg?kg(-1) hydrocarbons). The mean dissimilarity between fungal, but not bacterial, communities from the rhizosphere of different cultivars increased substantially in the HC blocks. This divergence was partly related to high fungal sensitivity to hydrocarbon contaminants, as demonstrated by reduced Shannon diversity, but also to a stronger influence of willows on fungal communities. Abundance of the fungal class Pezizomycetes in HC soils was directly related to willow phylogeny, with Pezizomycetes dominating the rhizosphere of a monophyletic cluster of cultivars, while remaining in low relative abundance in other soils. This has implications for plant selection in phytoremediation, as fungal associations may affect the health of introduced plants and the success of co-inoculated microbial strains. An integrated understanding of the relationships between fungi, bacteria and plants will enable the design of treatments that specifically promote effective bioremediating communities. PMID:23985744

Bell, Terrence H; El-Din Hassan, Saad; Lauron-Moreau, Aurélien; Al-Otaibi, Fahad; Hijri, Mohamed; Yergeau, Etienne; St-Arnaud, Marc

2014-02-01

281

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

PubMed

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 10 m x 10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2,135 ng g(-1), and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2,135 (30 days) to 1,196 ng g(-1) (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (>10) and low values of fluoranthene to pyrene ratio (0.3-0.4). PMID:12398405

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

2002-01-01

282

Rhamnolipid Produced from Agroindustrial Wastes Enhances Hydrocarbon Biodegradation in Contaminated Soil  

Microsoft Academic Search

A crude biosurfactant solution was produced by Pseudomonas aeruginosa growing on agroindustrial wastes as the substrate and used to study its effect on hydrocarbon biodegradation by the indigenous\\u000a soil microflora under laboratory conditions. Two concentrations were studied at first and 1 mg of biosurfactant\\/g of soil\\u000a showed to be the most efficient for the total petroleum hydrocarbon reduction, which reached

Maria Benincasa

2007-01-01

283

Sample preparation and characterization for a study of environmentally acceptable endpoints for hydrocarbon-contaminated soil  

SciTech Connect

In the past, the interdisciplinary research effort required to investigate the acceptable cleanup endpoints for hydrocarbon-impacted soils has been limited by the lack of standardized soils for testing. To support the efforts of the various researchers participating in the EAE research initiative, soil samples were collected from ten sites representing hydrocarbon-impacted soils typical of exploration/production, refinery, and bulk storage terminal operations. The hydrocarbons in the standard soils include crude oil, mixed refinery products, diesel, gasoline, and jet fuel. Physical characterization included analysis of soil texture, water retention, particle density, nanoporosity, pH, electrical conductivity, cation exchange capacity, buffer capacity, organic carbon, sodium adsorption ratio, and clay mineralogy. Chemical characterization included analysis of total recoverable petroleum hydrocarbons, total volatile and semivolatile organic compounds and metals, and TCLP for metals and organics. An analysis of the aliphatic and aromatic hydrocarbon fractions was performed on each soil to support the use of various models for assessing soil toxicity. Screening-level toxicity tests were conducted using Microtox{trademark}, plant seed germination and growth, and earthworm mortality and growth. Biodegradability screening tests were performed in slurry shake flasks to estimate the availability of hydrocarbon fractions to soil microorganisms.

Kreitinger, J.P.; Finn, J.T. [Remediation Technologies, Inc., Ithaca, NY (United States)

1995-12-31

284

Contrasting the community structure of arbuscular mycorrhizal fungi from hydrocarbon-contaminated and uncontaminated soils following willow (Salix spp. L.) planting.  

PubMed

Phytoremediation is a potentially inexpensive alternative to chemical treatment of hydrocarbon-contaminated soils, but its success depends heavily on identifying factors that govern the success of root-associated microorganisms involved in hydrocarbon degradation and plant growth stimulation. Arbuscular mycorrhizal fungi (AMF) form symbioses with many terrestrial plants, and are known to stimulate plant growth, although both species identity and the environment influence this relationship. Although AMF are suspected to play a role in plant adaptation to hydrocarbon contamination, their distribution in hydrocarbon-contaminated soils is not well known. In this study, we examined how AMF communities were structured within the rhizosphere of 11 introduced willow cultivars as well as unplanted controls across uncontaminated and hydrocarbon-contaminated soils at the site of a former petrochemical plant. We obtained 69 282 AMF-specific 18S rDNA sequences using 454-pyrosequencing, representing 27 OTUs. Contaminant concentration was the major influence on AMF community structure, with different AMF families dominating at each contaminant level. The most abundant operational taxonomic unit in each sample represented a large proportion of the total community, and this proportion was positively associated with increasing contamination, and seemingly, by planting as well. The most contaminated soils were dominated by three phylotypes closely related to Rhizophagus irregularis, while these OTUs represented only a small proportion of sequences in uncontaminated and moderately contaminated soils. These results suggest that in situ inoculation of AMF strains could be an important component of phytoremediation treatments, but that strains should be selected from the narrow group that is both adapted to contaminant toxicity and able to compete with indigenous AMF species. PMID:25032685

Hassan, Saad El-Din; Bell, Terrence H; Stefani, Franck O P; Denis, David; Hijri, Mohamed; St-Arnaud, Marc

2014-01-01

285

Contrasting the Community Structure of Arbuscular Mycorrhizal Fungi from Hydrocarbon-Contaminated and Uncontaminated Soils following Willow (Salix spp. L.) Planting  

PubMed Central

Phytoremediation is a potentially inexpensive alternative to chemical treatment of hydrocarbon-contaminated soils, but its success depends heavily on identifying factors that govern the success of root-associated microorganisms involved in hydrocarbon degradation and plant growth stimulation. Arbuscular mycorrhizal fungi (AMF) form symbioses with many terrestrial plants, and are known to stimulate plant growth, although both species identity and the environment influence this relationship. Although AMF are suspected to play a role in plant adaptation to hydrocarbon contamination, their distribution in hydrocarbon-contaminated soils is not well known. In this study, we examined how AMF communities were structured within the rhizosphere of 11 introduced willow cultivars as well as unplanted controls across uncontaminated and hydrocarbon-contaminated soils at the site of a former petrochemical plant. We obtained 69 282 AMF-specific 18S rDNA sequences using 454-pyrosequencing, representing 27 OTUs. Contaminant concentration was the major influence on AMF community structure, with different AMF families dominating at each contaminant level. The most abundant operational taxonomic unit in each sample represented a large proportion of the total community, and this proportion was positively associated with increasing contamination, and seemingly, by planting as well. The most contaminated soils were dominated by three phylotypes closely related to Rhizophagus irregularis, while these OTUs represented only a small proportion of sequences in uncontaminated and moderately contaminated soils. These results suggest that in situ inoculation of AMF strains could be an important component of phytoremediation treatments, but that strains should be selected from the narrow group that is both adapted to contaminant toxicity and able to compete with indigenous AMF species. PMID:25032685

Stefani, Franck O. P.; Denis, David; Hijri, Mohamed; St-Arnaud, Marc

2014-01-01

286

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

287

Novel Application of Cyclolipopeptide Amphisin: Feasibility Study as Additive to Remediate Polycyclic Aromatic Hydrocarbon (PAH) Contaminated Sediments  

PubMed Central

To decontaminate dredged harbor sediments by bioremediation or electromigration processes, adding biosurfactants could enhance the bioavailability or mobility of contaminants in an aqueous phase. Pure amphisin from Pseudomonas fluorescens DSS73 displays increased effectiveness in releasing polycyclic aromatic hydrocarbons (PAHs) strongly adsorbed to sediments when compared to a synthetic anionic surfactant. Amphisin production by the bacteria in the natural environment was also considered. DSS73’s growth is weakened by three model PAHs above saturation, but amphisin is still produced. Estuarine water feeding the dredged material disposal site of a Norman harbor (France) allows both P. fluorescens DSS73 growth and amphisin production. PMID:21673923

Groboillot, Anne; Portet-Koltalo, Florence; Le Derf, Franck; Feuilloley, Marc J. G.; Orange, Nicole; Poc, Cecile Duclairoir

2011-01-01

288

A numerical model for simulating the in-situ volatilization of hydrocarbon contaminants in soils  

Microsoft Academic Search

A three-dimensional model of the advective transport of organic contaminants in the gaseous phase of the unsaturated zone has been developed and tested against selected analytical solutions. The model accounts for the evaporation of contaminants from a pure liquid surface, partitioning of a contaminant from an aqueous solution and the adsorption\\/desorption of organics with soil particle surfaces. The results predict

G. P. SABADELL; D. K. SUNADA; N. S. GRIGG

1989-01-01

289

FEDERAL STAFF INFORMATION: SUBSURFACE REMEDIATION BRANCH (SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)  

EPA Science Inventory

The Subsurface Remediation Branch in NRMRL's Subsurface Protection and Remediation Division conducts research into defining the chemical, physical and biological processes that affect the fate, transport, and remediation of contaminants in the subsurface. The Branch's focus is o...

290

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

291

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 PMID:9924010

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

1999-01-01

292

Molecular Analysis of Surfactant-Driven Microbial Population Shifts in Hydrocarbon-Contaminated Soil†  

PubMed Central

We analyzed the impact of surfactant addition on hydrocarbon mineralization kinetics and the associated population shifts of hydrocarbon-degrading microorganisms in soil. A mixture of radiolabeled hexadecane and phenanthrene was added to batch soil vessels. Witconol SN70 (a nonionic, alcohol ethoxylate) was added in concentrations that bracketed the critical micelle concentration (CMC) in soil (CMC?) (determined to be 13 mg g?1). Addition of the surfactant at a concentration below the CMC? (2 mg g?1) did not affect the mineralization rates of either hydrocarbon. However, when surfactant was added at a concentration approaching the CMC? (10 mg g?1), hexadecane mineralization was delayed and phenanthrene mineralization was completely inhibited. Addition of surfactant at concentrations above the CMC? (40 mg g?1) completely inhibited mineralization of both phenanthrene and hexadecane. Denaturing gradient gel electrophoresis of 16S rRNA gene segments showed that hydrocarbon amendment stimulated Rhodococcus and Nocardia populations that were displaced by Pseudomonas and Alcaligenes populations at elevated surfactant levels. Parallel cultivation studies revealed that the Rhodococcus population can utilize hexadecane and that the Pseudomonas and Alcaligenes populations can utilize both Witconol SN70 and hexadecane for growth. The results suggest that surfactant applications necessary to achieve the CMC alter the microbial populations responsible for hydrocarbon mineralization. PMID:10877792

Colores, Gregory M.; Macur, Richard E.; Ward, David M.; Inskeep, William P.

2000-01-01

293

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

294

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

295

Increased mortality odds ratio of male liver cancer in a community contaminated by chlorinated hydrocarbons in groundwater  

PubMed Central

Aims: To investigate the association between cancer mortality risk and exposure to chlorinated hydrocarbons in groundwater of a downstream community near a contaminated site. Methods: Death certificates inclusive for the years 1966–97 were collected from two villages in the vicinity of an electronics factory operated between 1970 and 1992. These two villages were classified into the downstream (exposed) village and the upstream (unexposed) according to groundwater flow direction. Exposure classification was validated by the contaminant levels in 49 residential wells measured with gas chromatography/mass spectrometry. Mortality odds ratios (MORs) for cancer were calculated with cardiovascular-cerebrovascular diseases as the reference diseases. Multiple logistic regressions were performed to estimate the effects of exposure and period after adjustment for age. Results: Increased MORs were observed among males for all cancer, and liver cancer for the periods after 10 years of latency, namely, 1980–89, and 1990–97. Adjusted MOR for male liver cancer was 2.57 (95% confidence interval 1.21 to 5.46) with a significant linear trend for the period effect. Conclusion: The results suggest a link between exposure to chlorinated hydrocarbons and male liver cancer risk. However, the conclusion is limited by lack of individual information on groundwater exposure and potential confounding factors. PMID:12709523

Lee, L; Chung, C; Ma, Y; Wang, G; Chen, P; Hwang, Y; Wang, J

2003-01-01

296

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

297

Potential of vetiver (vetiveria zizanioides (L.) Nash) for phytoremediation of petroleum hydrocarbon-contaminated soils in Venezuela.  

PubMed

Venezuela is one of the largest oil producers in the world. For the rehabilitation of oil-contaminated sites, phytoremediation represents a promising technology whereby plants are used to enhance biodegradation processes in soil. A greenhouse study was conducted to determine the tolerance of vetiver (Vetiveria zizanioides (L.) Nash) to a Venezuelan heavy crude oil in soil. Additionally, the plant's potential for stimulating the biodegradation processes of petroleum hydrocarbons was tested under the application of two fertilizer levels. In the presence of contaminants, biomass and plant height were significantly reduced. As for fertilization, the lower fertilizer level led to higher biomass production. The specific root surface area was reduced under the effects of petroleum. However, vetiver was found to tolerate crude-oil contamination in a concentration of 5% (w/w). Concerning total oil and grease content in soil, no significant decrease under the influence of vetiver was detected when compared to the unplanted control. Thus, there was no evidence of vetiver enhancing the biodegradation of crude oil in soil under the conditions of this trial. However, uses of vetiver grass in relation to petroleum-contaminated soils are promising for amelioration of slightly polluted sites, to allow other species to get established and for erosion control. PMID:17305302

Brandt, Regine; Merkl, Nicole; Schultze-Kraft, Rainer; Infante, Carmen; Broll, Gabriele

2006-01-01

298

Studies on the dissolution of polycyclic aromatic hydrocarbons from contaminated materials using a novel dialysis tubing experimental method  

SciTech Connect

Assessment of risk and remediation strategies at contaminated sites requires that both the amounts of contaminants present and their potential for release from materials and soils be evaluated. The release, or dissolution, of polycyclic aromatic hydrocarbons (PAHs) from contaminated materials to water was therefore investigated. To facilitate investigations of PAH dissolution from physically disparate materials such as solid coal tars, creosote, oil, and spent oxide, an experimental method for measuring dissolved PAHs was developed employing dialysis tubing in batch-type system. This was validated and compared to aqueous-phase PAH concentrations measured using more traditional techniques and also predicted using Raoult's law. The experimental procedure was successfully used to determine near equilibrium aqueous concentrations of PAHs, but it could only be used to determine relative rates of approach to equilibrium as the dialysis tubing effected the rate constants. It was found that the contaminant materials influenced dissolution, in particular the close to equilibrium concentrations. For materials chemically similar to PAHs, such as nonaqueous-phase liquids (NAPLs), the concentrations could be predicted using Raoult's law. For materials that were chemically dissimilar to PAHs, such as spent oxide, release was more thermodynamically favorable than for NAPLs.

Woolgar, P.J. (Lancaster Univ. (United Kingdom) Scottish Environment Protection Agency, Stirling (United Kingdom)); Jones, K.C. (Lancaster Univ. (United Kingdom))

1999-06-15

299

Phytoremediation of abandoned crude oil contaminated drill sites of Assam with the aid of a hydrocarbon-degrading bacterial formulation.  

PubMed

Environmental deterioration due to crude oil contamination and abandoned drill sites is an ecological concern in Assam. To revive such contaminated sites, afield study was conducted to phytoremediate four crude oil abandoned drill sites of Assam (Gelakey, Amguri, Lakwa, and Borholla) with the aid of two hydrocarbon-degrading Pseudomonas strains designated N3 and N4. All the drill sites were contaminated with 15.1 to 32.8% crude oil, and the soil was alkaline in nature (pH8.0-8.7) with low moisture content, low soil conductivity and low activities of the soil enzymes phosphatase, dehydrogenase and urease. In addition, N, P, K, and C contents were below threshold limits, and the soil contained high levels of heavy metals. Bio-augmentation was achieved by applying Pseudomonas aeruginosa strains N3 and N4 followed by the introduction of screened plant species Tectona grandis, Gmelina arborea, Azadirachta indica, and Michelia champaca. The findings established the feasibility of the phytoremediation of abandoned crude oil-contaminated drill sites in Assam using microbes and native plants. PMID:24933892

Yenn, R; Borah, M; Boruah, H P Deka; Roy, A Sarma; Baruah, R; Saikia, N; Sahu, O P; Tamuli, A K

2014-01-01

300

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

301

Contamination of cheese by polycyclic aromatic hydrocarbons in traditional smoking. Influence of the position in the smokehouse on the contamination level of smoked cheese.  

PubMed

This paper sets out to determine the polycyclic aromatic hydrocarbon (PAH) contamination degree of a traditionally smoked cheese: Herreño cheese, which comes from one of the Canary Islands. Its PAH profile is thoroughly studied by means of gas chromatography-mass spectrometry in SIM mode, and compared with that of an unsmoked cheese. Furthermore, a parameter not previously studied is evaluated, namely the influence of the position of the individual cheeses in the smokehouse on their PAH contamination level. Heavy PAH, among which are included most of the carcinogens, are very scarce and their concentrations low. In fact, benz[a]anthracene, together with chrysene+triphenylene, are the only heavy PAH detected in all of the smoked samples studied. The concentration of benzo[a]pyrene, detected only in 1 of the samples, is below the limit established in Spain for the rind of smoked cheese. In contrast, high concentrations of light PAH have been found, especially of naphthalene and its alkyl derivatives, whose effect on human health is not yet well established. The results derived from the analysis of the PAH profile suggest the potential usefulness of certain ratios between some pairs of PAH (phenanthrene/anthracene, naphthalene/acenaphthylene) to provide information on the PAH contamination source. Furthermore, differences have been found, depending on the position of the cheeses in the smokehouse, those placed in the path followed by the smoke being more contaminated. Therefore, the findings of this study could help in improving the design of smokehouses, to decrease the PAH contamination degree of smoked cheese. PMID:21426955

Guillén, M D; Palencia, G; Ibargoitia, M L; Fresno, M; Sopelana, P

2011-04-01

302

Anaerobic Degradation of Polycyclic Aromatic Hydrocarbons and Alkanes in Petroleum-Contaminated Marine Harbor Sediments  

Microsoft Academic Search

Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaer- obic conditions, in a previous study an unusual site was found in San Diego Bay in which two PAHs, naphthalene and phenanthrene, were oxidized to carbon dioxide under sulfate-reducing conditions. Further investigations with these sediments revealed that methylnaphthalene, fluorene, and fluoranthene were also anaerobically oxidized to

JOHN D. COATES; JOAN WOODWARD; JON ALLEN; PAUL PHILP; DEREK R. LOVLEY

1997-01-01

303

A protocol to estimate the release of anthropogenic hydrocarbons from contaminated soils.  

PubMed

An operational protocol, appropriate for a tier 1 or tier 2 type relative risk evaluation of a site that has polycyclic aromatic hydrocarbon (PAH) or petroleum hydrocarbon impacted soils, was developed to estimate the fraction of anthropogenic hydrophobic hydrocarbons that will be released rapidly from such soils. The development of this protocol used over 400 datasets from 40 different field samples to establish and verify the operational protocol. The datasets resulted from four-month kinetic desorption studies of these field samples. Based on the chemicals evaluated, the protocol has greatest application to two, three, and four ring-PAH and to diesel range aliphatic hydrocarbons. The protocol is a simple batch desorption analysis that uses established methods and is conducted for 7 d. The protocol results were verified with specific correlation relationships (r2 = 0.81 to 0.96) to estimate the rapidly releasing fraction (F value) that is obtained in a full, four-month chemical release evaluation. PMID:12959552

Loehr, Raymond C; Lamar, Michael R; Poppendieck, Dustin G

2003-09-01

304

Contamination and potential biodegradation of polycyclic aromatic hydrocarbons in mangrove sediments of Xiamen, China  

Microsoft Academic Search

Five stations were established in the Fenglin mangrove area of Xiamen, China to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation potential of indigenous microorganisms and isolating the high molecule weight (HMW)–PAH degrading bacteria was also one of the aims of this work. The results showed that the

Yun Tian; Yuan-rong Luo; Tian-ling Zheng; Li-zhe Cai; Xiao-xing Cao; Chong-ling Yan

2008-01-01

305

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

SciTech Connect

Our research objectives are as follows: (1) Transform poplar and other tree species to extend and optimize chlorinated hydrocarbon (CHC) oxidative activities. (2) Determine the mechanisms of CHC oxidation in plants. (3) Isolate the genes responsible for CHC oxidation in plants.

Strand, Stuart E.

2003-06-01

306

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

2003-01-01

307

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...

308

Harnessing the Hydrocarbon-Degrading Potential of Contaminated Soils for the Bioremediation of Waste Engine Oil  

Microsoft Academic Search

Waste engine oil pollution is an endemic problem in African countries as waste oil is often discharged into the environment\\u000a without adequate treatment because waste oil recycling facilities are not readily available. In this study, laboratory-based\\u000a microcosms (natural attenuation, biostimulation, bioaugmentation and combined treatment of biostimulation–bioaugmentation)\\u000a were set up with soils (from old hydrocarbon biopiles) spiked with waste engine oil

Samuel Aleer; Eric M. Adetutu; Tanvi H. Makadia; Sayali Patil; Andrew S. Ball

2011-01-01

309

Effect of simulated rhizodeposition on the relative abundance of polynuclear aromatic hydrocarbon catabolic genes in a contaminated soil.  

PubMed

Microcosms were used to investigate whether soil exposure to mulberry root extracts (rich in phenolic compounds) select for bacteria that degrade polynuclear aromatic hydrocarbons (PAHs). Unlike previous studies with freshly spiked soil, the present experiments were conducted with soils aged for 518 d with [14C]phenanthrene to decrease bioavailability and avoid exaggerating the selective pressure exerted by PAHs relative to the rhizosphere effect. Microcosms simulating contaminated planted soil were exposed to carbon at 20 mg/L/week of mulberry root extract for 211 d to simulate rhizodeposition. Contaminated bulk soils microcosms were amended with a C-free mineral medium to discern the effect of rhizodeposition. Uncontaminated soil controls also were exposed to similar dose regimes. Real-time quantitative polymerase chain reaction was used to enumerate total bacteria and PAH degraders harboring the genes nahAc (coding for naphthalene dioxygenase), todC1 (coding for toluene/benzene/chlorobenzene dioxygenase), bmoA (coding for hydroxylating monooxygenases), and dmpN (coding for phenol hydroxylase). Exposure to root extracts enhanced the growth of total bacteria and PAH degraders in both contaminated and uncontaminated rhizosphere microcosms. The relative abundance of PAH-degrader gene copies (as a fraction of the total bacteria) was similar for different treatments, suggesting that the root extracts did not select for PAH degraders. Overall, these results suggest that rhizodeposition from phenolic releasers contributes to the fortuitous (but not selective) proliferation of PAH degraders, which may enhance phytoremediation. PMID:16519298

Da Silva, Marcio L B; Kamath, Roopa; Alvarez, Pedro J J

2006-02-01

310

Phytomediated biostimulation of the autochthonous bacterial community for the acceleration of the depletion of polycyclic aromatic hydrocarbons in contaminated sediments.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic contaminants causing hazards to organisms including humans. The objective of the study was to validate the vegetation of dredged sediments with Phragmites australis as an exploitable biostimulation approach to accelerate the depletion of PAHs in nitrogen spiked sediments. Vegetation with Phragmites australis resulted in being an efficient biostimulation approach for the depletion of an aged PAHs contamination (229.67 ± 15.56 ?g PAHs/g dry weight of sediment) in dredged sediments. Phragmites australis accelerated the oxidation of the PAHs by rhizodegradation. The phytobased approach resulted in 58.47% of PAHs depletion. The effects of the treatment have been analyzed in terms of both contaminant depletion and changes in relative abundance of the metabolically active Gram positive and Gram negative PAHs degraders. The metabolically active degraders were quantified both in the sediments and in the root endospheric microbial community. Quantitative real-time PCR reactions have been performed on the retrotranscribed transcripts encoding the Gram positive and Gram negative large ? subunit (RHD?) of the aromatic ring hydroxylating dioxygenases. The Gram positive degraders resulted in being selectively favored by vegetation with Phragmites australis and mandatory for the depletion of the six ring condensed indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene. PMID:25170516

Di Gregorio, Simona; Gentini, Alessandro; Siracusa, Giovanna; Becarelli, Simone; Azaizeh, Hassan; Lorenzi, Roberto

2014-01-01

311

Phytomediated Biostimulation of the Autochthonous Bacterial Community for the Acceleration of the Depletion of Polycyclic Aromatic Hydrocarbons in Contaminated Sediments  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic contaminants causing hazards to organisms including humans. The objective of the study was to validate the vegetation of dredged sediments with Phragmites australis as an exploitable biostimulation approach to accelerate the depletion of PAHs in nitrogen spiked sediments. Vegetation with Phragmites australis resulted in being an efficient biostimulation approach for the depletion of an aged PAHs contamination (229.67 ± 15.56??g PAHs/g dry weight of sediment) in dredged sediments. Phragmites australis accelerated the oxidation of the PAHs by rhizodegradation. The phytobased approach resulted in 58.47% of PAHs depletion. The effects of the treatment have been analyzed in terms of both contaminant depletion and changes in relative abundance of the metabolically active Gram positive and Gram negative PAHs degraders. The metabolically active degraders were quantified both in the sediments and in the root endospheric microbial community. Quantitative real-time PCR reactions have been performed on the retrotranscribed transcripts encoding the Gram positive and Gram negative large ? subunit (RHD?) of the aromatic ring hydroxylating dioxygenases. The Gram positive degraders resulted in being selectively favored by vegetation with Phragmites australis and mandatory for the depletion of the six ring condensed indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene.

Gentini, Alessandro; Becarelli, Simone; Azaizeh, Hassan

2014-01-01

312

MICROBIAL COMMUNITY STRUCTURE IN A SHALLOW HYDROCARBON-CONTAMINATED AQUIFER ASSOCIATED WITH HIGH ELECTRICAL CONDUCTIVITY  

EPA Science Inventory

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 hydr...

313

EVIDENCE FOR MICROBIAL ENHANCED ELECTRICAL CONDUCTIVITY IN HYDROCARBON-CONTAMINATED SEDIMENTS  

EPA Science Inventory

Electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale column experiment consisting of biotic contaminated and uncontaminated columns. Microbial population numbers increased with a clear pattern of depth zonation within the ...

314

Advanced fuel hydrocarbon remediation national test location - biocell treatment of petroleum contaminated soils  

SciTech Connect

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 air and moisture levels, degradation rates can be increased and total treatment time reduced over natural systems.

Heath, J.; Lory, E.

1997-03-01

315

Parameters describing nonequilibrium transport of polycyclic aromatic hydrocarbons through contaminated soil columns: Estimability analysis, correlation, and optimization  

NASA Astrophysics Data System (ADS)

The soil and groundwater at former industrial sites polluted by polycyclic aromatic hydrocarbons (PAHs) produce a very challenging environmental issue. The description of PAH transport by means of mathematical models is therefore needed for risk assessment and remediation strategies at these sites. Due to the complexity of release kinetics and transport behavior of the PAHs in the aged contaminated soils, their transport is usually evaluated at the laboratory scale. Transport parameters are then estimated from the experimental data via the inverse method. To better assess the uncertainty of optimized parameters, an estimability method was applied to firstly investigate the information content of experimental data and the possible correlations among parameters in the two-site sorption model. These works were based on the concentrations of three PAHs, Acenaphthene (ACE), Fluoranthene (FLA) and Pyrene (PYR), in the leaching solutions of the experiments under saturated and unsaturated flow conditions.

Ngo, Viet V.; Michel, Julien; Gujisaite, Valérie; Latifi, Abderrazak; Simonnot, Marie-Odile

2014-03-01

316

Microbial metabolism of polycyclic aromatic hydrocarbons (PAH) in creosote contaminated soils  

SciTech Connect

Creosote contaminated sites are of environmental significance due to the high concentrations of toxic and/or mutagenic PAH usually found at these sites. Microbial degradation of PAH can be seen as a novel form of contaminant detoxification. This paper describes the microbial degradation of PAH in creosote contaminated soils using (9-{sup 14}C) phenanthrene as a model PAH. Microbial metabolism was assessed with a mass balance approach as well as identification of PAH metabolites by GC/MS/FTIR. The mass balance accounted for the amount portion of the added phenanthrene. To confirm the effectiveness of microbial degradation to decrease soil toxicity, the Microtox{reg_sign} and Mutatox{reg_sign} assays were used to monitor toxicity of the creosote soils throughout the experiments. Mass balance results indicated that phenanthrene was readily mineralized in the contaminated soils, while metabolite production accounted for only a minor portion of the added phenanthrene. Toxicity of contaminated soils increased slightly early in the incubation and then decreased over longer time periods. Mutagenicity of soils, however, did not decrease appreciably over a 3-month time period. The identity of metabolic products found in the soils will be discussed.

Carmichael, L.M.; Pfaender, F.K. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering

1994-12-31

317

X-Ray Photoelectron Spectroscopy Study of the Effect of Hydrocarbon Contamination on Poly(Tetrafluoroethylene) Exposed to a Nitrogen Plasma  

NASA Technical Reports Server (NTRS)

It has been shown that unless the surface of poly(tetrafluoroethylene)(PTFE) is free of hydrocarbon contamination, anomalous changes in the oxygen and fluorine contents, as measured by X-ray photoelectron spectroscopy (XPS), and hence also the surface properties, may be improperly ascribed to a PTFE film exposed to a oxygen plasma.

Golub, Morton A.; Lopata, Eugene S.; Finney, Lorie S.

1993-01-01

318

Hydrocarbon balance of a site which had been highly and chronically contaminated by petroleum wastes of a refinery (from 1956 to 1992)  

Microsoft Academic Search

Petroleum hydrocarbon pollution in the Gulf of Fos (South France) was studied following the cessation of petroleum waste discharge from an oil refinery in the Lavera area. Sediments were collected in core samples of 30 cm at eight stations along a radial from the refinery to the open sea. Petroleum contamination has been detected up to the beginning of the

Yveline Le Dréau; Frédéric Jacquot; Pierre Doumenq; Michel Guiliano; Jean Claude Bertrand; Gilbert Mille

1997-01-01

319

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

Microsoft Academic Search

The purpose of this study was to determine the concentration and types of polycyclic aromatic hydrocarbons (PAHs), a group of environmentally toxic and persistent chemicals, at contaminated oil exploration and production (E&P) sites located in environmentally sensitive and geographically distinct areas throughout Texas. Samples of tank bottom solids, the oily sediment that collects at the bottom of the tanks, were

Heidi K. Bojes; Peter G. Pope

2007-01-01

320

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

SciTech Connect

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

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

1997-01-01

321

Monitoring the Natural Recovery of Hydrocarbon-Contaminated Sediments with Chemical Fingerprinting  

Microsoft Academic Search

Drs. Scott A. Stout, Gregory S. Douglas, and Allen D. Uhler are principals at NewFields Environmental Forensics Practice, LLC, in Rockland, Massachusetts. They each have over 15 years experience in the chemical characterization of petroleum and related contaminants in the environment. Their firm specializes in the application of chemical fingerprinting and other forensic tools in assessing liability associated with environmental

Scott A. Stout; Allen D. Uhler; Gregory S. Douglas

2005-01-01

322

Bioremediation Of Groundwater Contaminated Wtih Gasoline Hydrocarbons And Oxygenates Using A Membrane-Based Reactor  

EPA Science Inventory

The objective of this study was to operate a novel, field-scale, aerobic bioreactor and assess its performance in the ex situ treatment of groundwater contaminated with gasoline from a leaking underground storage tank in Pascoag, RI. The groundwater contained elevated concentrat...

323

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

SciTech Connect

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

Strand, Stuart E.

2002-06-01

324

CONTAMINANT TRANSPORT RESULTING FROM MULTICOMPONENT NONAQUEOUS PHASE LIQUID POOL DISSOLUTION IN THREE-DIMENSIONAL SUBSURFACE FORMATIONS (R823579)  

EPA Science Inventory

A semi-analytical method for simulating transient contaminant transport originating from the dissolution of multicomponent nonaqueous phase liquid (NAPL) pools in three-dimensional, saturated, homogeneous porous media is presented. Each dissolved component may undergo first-order...

325

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

326

Characterization of novel polycyclic aromatic hydrocarbon dioxygenases from the bacterial metagenomic DNA of a contaminated soil.  

PubMed

Ring-hydroxylating dioxygenases (RHDs) play a crucial role in the biodegradation of a range of aromatic hydrocarbons found on polluted sites, including polycyclic aromatic hydrocarbons (PAHs). Current knowledge on RHDs comes essentially from studies on culturable bacterial strains, while compelling evidence indicates that pollutant removal is mostly achieved by uncultured species. In this study, a combination of DNA-SIP labeling and metagenomic sequence analysis was implemented to investigate the metabolic potential of main PAH degraders on a polluted site. Following in situ labeling using [(13)C]phenanthrene, the labeled metagenomic DNA was isolated from soil and subjected to shotgun sequencing. Most annotated sequences were predicted to belong to Betaproteobacteria, especially Rhodocyclaceae and Burkholderiales, which is consistent with previous findings showing that main PAH degraders on this site were affiliated to these taxa. Based on metagenomic data, four RHD gene sets were amplified and cloned from soil DNA. For each set, PCR yielded multiple amplicons with sequences differing by up to 321 nucleotides (17%), reflecting the great genetic diversity prevailing in soil. RHDs were successfully overexpressed in Escherichia coli, but full activity required the coexpression of two electron carrier genes, also cloned from soil DNA. Remarkably, two RHDs exhibited much higher activity when associated with electron carriers from a sphingomonad. The four RHDs showed markedly different preferences for two- and three-ring PAHs but were poorly active on four-ring PAHs. Three RHDs preferentially hydroxylated phenanthrene on the C-1 and C-2 positions rather than on the C-3 and C-4 positions, suggesting that degradation occurred through an alternate pathway. PMID:25128340

Chemerys, Angelina; Pelletier, Eric; Cruaud, Corinne; Martin, Florence; Violet, Fabien; Jouanneau, Yves

2014-11-01

327

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

Microsoft Academic Search

Fe(III)-reducing bacteria yielded cell counts of up to 240 cells ml1 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

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

2003-01-01

328

Geophysical Signatures of Microbial Activity at Hydrocarbon Contaminated Sites: A Review  

Microsoft Academic Search

Microorganisms participate in a variety of geologic processes that alter the chemical and physical properties of their environment.\\u000a Understanding the geophysical signatures of microbial activity in the environment has resulted in the development of a new\\u000a sub-discipline in geophysics called “biogeophysics”. This review focuses primarily on literature pertaining to biogeophysical\\u000a signatures of sites contaminated by light non-aqueous phase liquids (LNAPL),

Estella A. Atekwana; Eliot A. Atekwana

2010-01-01

329

The physiology of mycorrhizal Lolium multiflorum in the phytoremediation of petroleum hydrocarbon-contaminated soil  

E-print Network

paucimobilis EPA505 (Sp)] on total phenolics and total antioxidant activity in leaves of Lolium multiflorum var. Passerel Plus during the phytoremediation of benzo[a]pyrene- contaminated sand ????????????????????.... Effect of Glomus intraradices (AMF... ?..?????????????????????... Effect of rhizosphere management (RM) and Arabian medium crude oil (ACO) on leaf nitrate reductase activity, proline, antioxidant activity, and total phenolics of Lolium multiflorum cv. Passerel Plus, after 80 days...

Alarcon, Alejandro

2009-06-02

330

Relationship between heavy fuel oil phytotoxicity and polycyclic aromatic hydrocarbon contamination in Salicornia fragilis.  

PubMed

Greenhouse experiments were carried out to study the effects of heavy fuel oil contamination on the growth and the development of Salicornia fragilis Ball and Tutin, a salt-marsh edible species. Plants were sampled in spring at the "Aber du Conquet" (Finistère, France), and artificially exposed by coating shoot sections with N degrees 6 fuel oil or by mixing it in their substratum. The impact of petroleum on plant development was followed by phytotoxicity assessments and PAH shoots assays. The plants exhibited visual symptoms of stress, i.e. chlorosis, yellowing, growth reduction and perturbations in developmental parameters. The contamination of plants by shoot coating appeared to be less than through soil. Moreover, the increase of the degree of pollution induced more marked effects on plants, likely because of the physical effects of fuel. However, bioaccumulation of PAHs in shoot tissues was also found to be significant, even at very low levels of contamination, and highly related to the conditions of exposure to oil. The strong relationships between the PAH contents of Salicornia plants and growth reduction suggest a chemical toxicity of fuel oil, compounds like PAHs being known to inhibit physiological processes in plants. PMID:17493664

Meudec, Anna; Poupart, Nathalie; Dussauze, Jacques; Deslandes, Eric

2007-08-01

331

Impact of erosion and transfer processes in Polycyclic Aromatic Hydrocarbon contamination of water bodies in the Seine River basin (France)  

NASA Astrophysics Data System (ADS)

Polycyclic Aromatic Hydrocarbons (PAHs) reach problematic concentrations in water and sediment of numerous streams of the world. In the Seine River (France), they prevent to achieve the good chemical status enforced by European law. However, the provenance and the fate of PAHs found in rivers are still poorly understood. Here, we combined chemical and fallout radionuclide measurements conducted on a large number of suspended sediment (SS) (n = 231) and soil (n = 37) samples collected at 62 sites during an entire hydrological year. A model was developed to estimate mean PAH concentration in sediment from the population density in the drainage area and good relationships were found during both low stage and flood periods. Influence of human population also appeared to be stronger during the latter period. However, some discrepancies between measured and modeled PAH concentrations were observed and the role of the origin of SS was investigated. During the low flow period, the observed differences were explained by the provenance of river sediment (agricultural topsoil vs. eroded channel banks). Time-averaged PAH concentrations measured in suspended sediment collected in the catchments where erosion of agricultural topsoil dominated were systematically higher than the predicted values. On the contrary, in the catchments where erosion mainly occurred in deep soil or river embankment, the supply of particles protected from atmospheric fallout contamination led to measure concentrations below the predicted values. As this relationship between population density and SS contamination was no longer valid during the flood period, the role of transfer times was also investigated. The percentages of freshly eroded sediment in samples were determined by comparing the 7Be/210Pb ratio in rainfall and SS. An annual turn-over cycle of sediment was observed but no relationship was found between PAH contamination and residence times of particles within rivers. This result suggested that the impact of PAH exchanges between aqueous and particulate phases was negligible. Finally, results derived from PAH diagnostic ratios showed that the contamination signature vary between rural soil and urban signatures therefore suggesting that the temporal changes in riverine pollution mainly depend on the variations of contribution of both pools. More specifically, the low flow period is characterized by background signal provided by erosion and mainly driven by the origin of SS and the stocks accumulated in the vicinity of anthropogenic activities. During the flood period, an additional signal of contamination is provided by direct urban releases due to the increase in PAH emissions (household heating) and impervious surface leaching.

Gateuille, David; Evrard, Olivier; Moreau-Guigon, Elodie; Chevreuil, Marc; Mouchel, Jean-Marie

2014-05-01

332

Bioremediation of groundwater contaminated with gasoline hydrocarbons and oxygenates using a membrane-based reactor.  

PubMed

The objective of this study was to operate a novel, field-scale, aerobic bioreactor and assess its performance in the ex situ treatment of groundwater contaminated with gasoline from a leaking underground storage tank in Pascoag, RI. The groundwater contained elevated concentrations of MTBE (methyl tert-butyl ether), TBA (tert-butyl alcohol), TBF (tert-butyl formate), BTEX (benzene, toluene, ethyl benzene, and xylene isomers), and other gasoline additives (tert-amyl methyl ether, di-isopropyl ether, tert-amyl alcohol, methanol, and acetone). The bioreactor was a gravity-flow membrane-based system called a Biomass Concentrator Reactor (BCR) designed to retain all biomass within the reactor. It was operated for six months at an influent flow rate that ultimately reached 5 gpm. The goal was to achieve a removal of all contaminants to <5 microg/L, which is the California Drinking Water advisory for MTBE. The concentration of TBA, an MTBE biodegradation byproduct, was consistently lower than that of MTBE. The other daughter compound detected in the influent, TBF, was degraded to concentrations below the detection limit of 0.02 microg/L. BTEX were consistently degraded to significantly lower levels in the effluent throughout the duration of the study (<1 microg/L). A similar high removal efficiency of the other gasoline oxygenates present in the groundwater (TAME, DIPE, and TAA) was also achieved. Dissolved organic carbon analysis demonstrated the ability of the bioreactor to produce high quality effluents with nonpurgeable organic carbon (NPOC) averaging approximately 50% lowerthan the NPOC concentrations in the influent contaminated groundwater. PMID:16570627

Zein, Maher M; Suidan, Makram T; Venosa, Albert D

2006-03-15

333

Microbial diversity, community composition and metabolic potential in hydrocarbon contaminated oily sludge: prospects for in situ bioremediation.  

PubMed

Microbial community composition and metabolic potential have been explored in petroleum-hydrocarbon-contaminated sludge of an oil storage facility. Culture-independent clone library-based 16S rRNA gene analyses revealed that the bacterial community within the sludge was dominated by the members of ?-Proteobacteria (35%), followed by Firmicutes (13%), ?-Proteobacteria (11%), Bacteroidetes (10%), Acidobacteria (6%), ?-Proteobacteria (3%), Lentisphaerae (2%), Spirochaetes (2%), and unclassified bacteria (5%), whereas the archaeal community was composed of Thermoprotei (54%), Methanocellales (33%), Methanosarcinales/Methanosaeta (8%) and Methanoculleus (1%) members. Methyl coenzyme M reductase A (mcrA) gene (a functional biomarker) analyses also revealed predominance of hydrogenotrophic, methanogenic Archaea (Methanocellales, Methanobacteriales and Methanoculleus members) over acetoclastic methanogens (Methanosarcinales members). In order to explore the cultivable bacterial population, a total of 28 resident strains were identified and characterized in terms of their physiological and metabolic capabilities. Most of these could be taxonomically affiliated to the members of the genera Bacillus, Paenibacillus, Micrococcus, Brachybacterium, Aerococcus, and Zimmermannella, while two strains were identified as Pseudomonas and Pseudoxanthomonas. Metabolic profiling exhibited that majority of these isolates were capable of growing in presence of a variety of petroleum hydrocarbons as sole source of carbon, tolerating different heavy metals at higher concentrations (?1 mM) and producing biosurfactant during growth. Many strains could grow under a wide range of pH, temperature, or salinity as well as under anaerobic conditions in the presence of different electron acceptors and donors in the growth medium. Correlation between the isolates and their metabolic properties was estimated by the unweighted pair group method with arithmetic mean (UPGMA) analysis. Overall observation indicated the presence of diverse groups of microorganisms including hydrocarbonoclastic, nitrate reducing, sulphate reducing, fermentative, syntrophic, methanogenic and methane-oxidizing bacteria and Archaea within the sludge community, which can be exploited for in situ bioremediation of the oily sludge. PMID:24682711

Das, Ranjit; Kazy, Sufia K

2014-06-01

334

Contamination and distribution of parent, nitrated, and oxygenated polycyclic aromatic hydrocarbons in smoked meat.  

PubMed

Smoked meat is widely consumed in many areas, particularly in rural southwest China. High concentrations of polycyclic aromatic hydrocarbons (PAHs) in smoked meat could lead to adverse dietary exposure and health risks. In this study, 27 parent PAHs (pPAHs), 12 nitrated PAHs (nPAHs), and 4 oxygenated PAHs (oPAHs) were measured in coal- and wood-smoked meats. The median concentrations of pPAHs, nPAHs, and oPAHs were as high as 1.66?×?10(3), 4.29, and 20.5 ng/g in the coal-smoked meat and 2.54?×?10(3), 7.32, and 9.26 ng/g in the wood-smoked meat, respectively. Based on the relative potency factors of individual PAHs, the calculated toxic equivalent (TEQ) values of all pPAHs were 22.1 and 75.1 ng TEQ/g for the wood- and coal-smoked meats, respectively. The highest concentrations of PAHs can be found in the surface layer of skin and decrease exponentially with depth. Surface PAH concentrations correlated with concentrations of PAHs in household air and with the concentration in emission exhaust. Migration of PAHs from surface to interior portions of meat is faster in lean than in fat or skin, and oPAHs and pPAHs can penetrate deeper than pPAHs. The penetration ability of PAHs is negatively correlated with the molecular weight. PMID:24910314

Chen, Yuanchen; Shen, Guofeng; Su, Shu; Shen, Huizhong; Huang, Ye; Li, Tongchao; Li, Wei; Zhang, Yanyan; Lu, Yan; Chen, Han; Yang, Chunli; Lin, Nan; Zhu, Ying; Fu, Xiaofang; Liu, Wenxin; Wang, Xilong; Tao, Shu

2014-10-01

335

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

SciTech Connect

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

Stuart Strand

2004-09-27

336

Identifying the sources of subsurface contamination at the Hanford site in Washington using high-precision uranium isotopic measurements  

NASA Astrophysics Data System (ADS)

The contrasts in isotopic composition between natural and anthropogenic uranium promotes the measurement of uranium isotopic composition as a fingerprint and tracer of uranium contamination in the environment. At the Hanford site, there are multiple plumes of a variety of contaminants, including uranium, resulting from decades of nuclear fuel production and processing. We focused in particular on a uranium groundwater plume and two vadose zone U plumes associated with the B-BX-BY tank farm. The groundwater plume (>30 ppb U) is currently approximately 250 m wide, at least 900 m long with U concentrations up to 525 ppb. The precise origin and history of this contamination is not well understood, since a number of tanks and incidents are potential sources. Here we report the isotopic compositions of U from vadose zone samples obtained from two contaminated cores in the B-BX-BY tank farm, and of U from groundwater samples. The isotopic analyses produce a link between a particular vadose zone U plume and groundwater contamination, identify contamination sources, and provide estimates of the relative proportions of anthropogenic uranium in the analyzed samples. In addition, the U isotopic compositions can be related to the estimated history of U use to constrain the history of contamination events in the B-BX-BY tank farm. Samples from two vadose zone cores were analyzed, one from near tank BX-102, the other near tank B-110. Both these cores are located SW of the axis of the groundwater plume. Isotopic compositions (234U/238U, 235U/238U and 236U/238U) of chemically separated U were measured on an Isoprobe, multiple collector ICP source mass spectrometer. Based on the U isotopic data, we find that the vadose zone plume associated with tank BX-102 is more likely a source of the ground water plume, rather than the vadose zone plume associated with tank B-110. From a comparison with a model history of the isotopic composition of processed U, the BX-102 vadose zone plume is consistent with a 1951 spill. A similar comparison for the B-110 plume, suggests that the origin of that contamination was an incident early in the history of processing, rather than a known 1970/1971 leak from tank B-110.

Christensen, J. N.; Dresel, P. E.; Maher, K.; Conrad, M. S.; Depaolo, D. J.

2003-04-01

337

Polycyclic aromatic hydrocarbon contamination in an urban area assessed by Quercus ilex leaves and soil.  

PubMed

We investigated the PAH contamination of Naples urban area, densely populated and with high traffic flow, by analyses of environmental matrices: soil and Quercus ilex leaves. Being some PAHs demonstrated to have hazardous effects on human health, the accumulation of carcinogenic and toxic PAHs (expressed as B(a)Peq) was evaluated in the leaves and soil. The main sources of the PAHs were discriminated by the diagnostic ratios in the two matrices. The urban area appeared heavily contaminated by PAHs, showing in soil and leaves total PAH concentrations also fivefold higher than those from the remote area. The soil mainly accumulated heavy PAHs, whereas leaves the lightest ones. Median values of carcinogenic PAH concentrations were higher in soil (440 ng g(-1) d.w.) and leaves (340 ng g(-1) d.w.) from the urban than the remote area (60 and 70 ng g(-1) d.w., respectively, for soil and leaves). Also, median B(a)Peq concentrations were higher both in soil and leaves from the urban (137 and 63 ng g(-1) d.w., respectively) than those from the remote area (19 and 49 ng g(-1) d.w., respectively). Different from the soils, the diagnostic ratios found for the leaves discerned PAH sources in the remote and urban areas, highlighting a great contribution of vehicular traffic emission as main PAH source in the urban area. PMID:24604269

De Nicola, F; Alfani, A; Maisto, G

2014-06-01

338

Final Report Coupling in silico microbial models with reactive transport models to predict the fate of contaminants in the subsurface.  

SciTech Connect

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 this modeling approach can be used to develop new strategies to optimize bioremediation. The approach of coupling genome-scale metabolic models with reactive transport modeling is now well enough established that it has been adopted by other DOE investigators studying uranium bioremediation. Furthermore, the basic principles developed during our studies will be applicable to much broader investigations of microbial activities, not only for other types of bioremediation, but microbial metabolism in diversity of environments. This approach has the potential to make an important contribution to predicting the impact of environmental perturbations on the cycling of carbon and other biogeochemical cycles.

Lovley, Derek R.

2012-10-31

339

Removal of petroleum hydrocarbons from contaminated groundwater by the combined technique of adsorption onto perlite followed by the O3/H2O2 process.  

PubMed

Groundwater contaminated with petroleum hydrocarbons was treated using a combined system of adsorption onto powdered expanded perlite (PEP) followed by the O3/H2O2 process. The pretreatment investigations indicated a high capacity for PEP to remove petroleum hydrocarbons from the contaminated water. An experimental total petroleum hydrocarbon (TPH) adsorption capacity of 275 mg/g PEP was obtained at the natural pH of water. The experimental data fit best with the Freundlich isotherm model and pseudo-second-order adsorption model. The second phase of the experiment evaluated the performance of the O3/H2O2 process in the removal of residual TPH from pretreated water and compared the results with that of raw water. The O3/H202 process attained a maximum TPH removal rate for the pretreated water after 70 min, when 93% of the residual TPH in the effluent of the adsorption system was removed. Overall, the combination of adsorption onto PEP for 100 min and the subsequent treatment with the O3/H2O2 process for 70min eliminated over 99% of the TPH of highly petroleum-contaminated groundwater, with initial values of 162 mg/L. Therefore, we can conclude that the developed treatment system is an appropriate method of remediation for petroleum-contaminated waters. PMID:23240183

Moussavi, Gholamreza; Bagheri, Amir

2012-09-01

340

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

EPA Science Inventory

Remediation of hazardous material spills is often costly and entails cumbersome procedures. he traditional method is to drill core samples in the area where the contaminant is thought to be present and then analyze these samples in a laboratory. he denser the sampling grid, the m...

341

Sampling and Analysis Instruction for Evaluation of Residual Chromium Contamination in the Subsurface Soil at 100-C-7  

SciTech Connect

This sampling and analysis instruction (SAI) provides the requirements for sample collection and laboratory analysis to evaluate the extent of hexavalent chromium contamination present in the soil below the 100-C-7 and 100-C-7:1 remedial action waste site excavations.

W. S. Thompson

2007-02-15

342

Utilization of biosolids during the phytoremediation of hydrocarbon-contaminated soil.  

PubMed

Addition of anaerobically digested sewage sludge (biosolids) to soil may improve conditions for phytoremediation of petroleum hydrocarbons (PHCs) through improved soil chemical, biological, and physical properties. A 32-wk greenhouse study investigated three rates of biosolids addition (0, 13.34, and 26.68 g oven-dry biosolids kg(-1) oven-dry soil) and the presence or absence of smooth brome (Bromus inermis Leyss. cv. Carlton) plants on the removal of diesel (3.5 g kg(-1) oven-dry soil) in an industrial, sandy loam soil. Diesel PHCs were divided into two fractions based on equivalent normal straight-chain boiling point ranges (F2: nC10-nC16; F3: nC16-nC34). The addition of biosolids did not increase the extent of PHC degradation but did result in significantly greater first-order decay constants compared to unamended controls. Overall, the presence of plants did not increase the rate or extent of PHC degradation, relative to that observed in unamended, non-vegetated soils. Vegetation was, however, an important factor within the biosolids-amended soils as was observed by a greater extent of PHC degradation. Some of this decrease was attributed to plant-induced removal of biosolids components that were contributing to the F3 fraction. Overall, the low-amendment rate (13.34 g oven-dry biosolids kg(-1) oven-dry soil) was considered to be the most effective treatment because it produced the greatest overall PHC degradation rate (0.226 wk(-1) for total PHCs) and resulted in the greatest recovery of biosolids-derived N by smooth brome (26.6%). PMID:16738382

Dickinson, S J; Rutherford, P M

2006-01-01

343

Subsurface characterization of groundwater contaminated by landfill leachate using microbial community profile data and a nonparametric decision-making process  

NASA Astrophysics Data System (ADS)

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 data-driven methodology is based on clustering a set of molecular genetic-based microbial community profiles. Microbes were sampled from groundwater monitoring wells located within and around an aquifer contaminated with landfill leachate. We modified a self-organizing map (SOM) to weight the input variables by their relative importance and provide statistical guidance for classifying sample similarities. The methodology includes the following steps: (1) preprocessing the microbial data into a smaller number of independent variables using principal component analysis, (2) clustering the resulting principal component (PC) scores using a modified SOM capable of weighting the input PC scores by the percent variance explained by each score, and (3) using a nonparametric statistic to guide selection of appropriate groupings for management purposes. In this landfill leachate application, the weighted SOM assembles the microbial community data from monitoring wells into groupings believed to represent a gradient of site contamination that could aid in characterization and long-term monitoring decisions. Groupings based solely on microbial classifications are consistent with classifications of water quality from hydrochemical information. These microbial community profile data and improved decision-making strategy compliment traditional chemical groundwater analyses for delineating spatial zones of groundwater contamination.

Pearce, Andrea R.; Rizzo, Donna M.; Mouser, Paula J.

2011-06-01

344

Bald eagle mortality and chlorinated hydrocarbon contaminants in livers from British Columbia, Canada, 1989-1994.  

PubMed

Between 1989 and 1994, we obtained 278 carcasses of bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada. All specimens were necropsied and the cause of death determined wherever possible. Livers from a subset of 75 birds were analyzed for polychlorinated biphenyl (PCB) and organochlorine (OC) pesticide residues. A further subset of 19 eagles found dead around the Strait of Georgia, an area of known pulp mill pollution, in summer, and therefore presumably resident birds, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and non-ortho PCBs. Liver concentrations ranged from less than 1 to 190 mg/kg for DDE, and up to 72 mg/kg for total PCBs. Concentrations of other OCs were generally less than 1 mg/kg, with the exception of chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs and PCDFs contained detectable concentrations of the major 2,3,7,8-substituted isomers. Some birds were very contaminated; one eagle found near a kraft pulp mill site in 1990 contained: 400 ng/kg 2,3,7,8-TCDD, 1400 ng/kg 1,2,3,7,8-PnCDD and 4400 ng/kg 1,2,3,6,7,8-HxCDD. Birds with higher PCB and dichlorodiphenyldichloroethane (DDE) concentrations appeared to weigh less, and there was a significant negative relationship between both PCBs and DDE and numeric scoring of body condition, reflecting the well known process of starvation-induced mobilization of body lipids and contaminants. Birds with higher 2,3,7,8-TCDD concentrations tended to have unusually low concentrations of 2,3,7,8-TCDF, interpreted to indicate hepatic cytochrome P4501A-type induction by TCDD and subsequent metabolism of TCDF. PMID:15093512

Elliott, J E; Wilson, L K; Langelier, K W; Norstrom, R J

1996-01-01

345

Water quality concerns due to forest fires: polycyclic aromatic hydrocarbons (PAH) contamination of groundwater from mountain areas.  

PubMed

Water quality alterations due to forest fires may considerably affect aquatic organisms and water resources. These impacts are cumulative as a result of pollutants mobilized from fires, chemicals used to fight fire, and postfire responses. Few studies have examined postfire transport into water resources of trace elements, including the polycyclic aromatic hydrocarbons (PAH), which are organic pollutants produced during combustion and are considered carcinogenic and harmful to humans. PAH are also known to adversely affect survival, growth, and reproduction of many aquatic species. This study assessed the effects of forest wildfires on groundwater from two mountain regions located in protected areas from north and central Portugal. Two campaigns to collect water samples were performed in order to measure PAH levels. Fifteen of 16 studied PAH were found in groundwater samples collected at burned areas, most of them at concentrations significantly higher than those found in control regions, indicating aquifer contamination. The total sum of PAH in burned areas ranged from 23.1to 95.1 ng/L with a median of 62.9 ng/L, which is one- to sixfold higher than the average level measured in controls (16.2 ng/L). In addition, in control samples, the levels of light PAH with two to four rings were at higher levels than heavy PAH with five or six rings, thus showing a different profile between control and burned sites. The contribution of wildfires to groundwater contamination by PAH was demonstrated, enabling a reliable assessment of the impacts on water quality and preparation of scientifically based decision criteria for postfire forest management practices. PMID:25072713

Mansilha, C; Carvalho, A; Guimarães, P; Espinha Marques, J

2014-01-01

346

Stable-isotope probing of the polycyclic aromatic hydrocarbon-degrading bacterial guild in a contaminated soil.  

PubMed

The bacteria responsible for the degradation of naphthalene, phenanthrene, pyrene, fluoranthene or benz[a]anthracene in a polycyclic aromatic hydrocarbon (PAH)-contaminated soil were investigated by DNA-based stable-isotope probing (SIP). Clone libraries of 16S rRNA genes were generated from the (13) C-enriched ('heavy') DNA recovered from each SIP experiment, and quantitative PCR primers targeting the 16S rRNA gene were developed to measure the abundances of many of the SIP-identified sequences. Clone libraries from the SIP experiments with naphthalene, phenanthrene and fluoranthene primarily contained sequences related to bacteria previously associated with the degradation of those compounds. However, Pigmentiphaga-related sequences were newly associated with naphthalene and phenanthrene degradation, and sequences from a group of uncultivated ?-Proteobacteria known as Pyrene Group 2 were newly associated with fluoranthene and benz[a]anthracene degradation. Pyrene Group 2-related sequences were the only sequences recovered from the clone library generated from SIP with pyrene, and they were 82% of the sequences recovered from the clone library generated from SIP with benz[a]anthracene. In time-course experiments with each substrate in unlabelled form, the abundance of each of the measured groups increased in response to the corresponding substrate. These results provide a comprehensive description of the microbial ecology of a PAH-contaminated soil as it relates to the biodegradation of PAHs from two to four rings, and they underscore that bacteria in Pyrene Group 2 are well-suited for the degradation of four-ring PAHs. PMID:21564459

Jones, Maiysha D; Crandell, Douglas W; Singleton, David R; Aitken, Michael D

2011-10-01

347

Evaluation of sediment contamination by heavy metals, organochlorinated pesticides, and polycyclic aromatic hydrocarbons in the Berre coastal lagoon (southeast France).  

PubMed

During the last decades, the Berre lagoon, located in southeastern France, has been deeply affected by strong contaminant inputs. Surveys of surface sediment contamination have been sparsely performed since 1964 with data often disconnected with regard to time and space. To contribute to filling this gap, this study examined the pollution status of the lagoon during a 2012 sampling. Concentrations of heavy metals (HMs) (cadmium [Cd], chromium [Cr], copper [Cu], lead [Pb], and zinc [Zn]), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons were examined. The available seawater metal fraction was also investigated. Water from the Vaine basin (VB; stations 1 through 6) exhibited the lowest oxygen concentration (mean O?% saturation 38.9%). HM loads were in the order of Zn > Cr > Pb > Cu > Cd with overall concentration ranges of 0.20-1.40 mg kg(-1) for Cd, 17.1-119 mg kg(-1) for Cr, 7.0-60.7 g(-1) for Cu, 12.0-104 mg kg(-1) for Pb, and 56.5-215 mg kg(-1) for Zn. Although HMs accumulated at levels largely exceeding their relative natural background level of 11-fold for Pb and 80-fold for Zn, their mean concentrations decreased largely to below the acceptable legal limits. HM loads were 20 to threefold the relative corresponding value of the threshold effect level benchmark of potential biological risk. Metals were only scantly released by sediments with mean percentage release of 0.99% for Cd and 40.2% for Cr with a peak for this latter element of 99% in the VB sector. In the case of OCPs, sediments appeared to be significantly polluted, especially in the VB area, with a mean lindane concentration of 0.05 mg kg(-1), which is ? fivefold the legal threshold. Among PAHs, benzo[a]pyrene exceeded the permitted limit of 0.1 mg kg(-1) mainly in the VB sector. PMID:23712770

Arienzo, M; Masuccio, A A; Ferrara, L

2013-10-01

348

Chlorinated hydrocarbon contaminants in feces of river otters from the southern Pacific coast of Canada, 1998-2004.  

PubMed

Chlorinated hydrocarbon contaminants in coastal river otters (Lontra canadensis) were evaluated by sampling feces (scats) collected on the south coast of British Columbia, Canada. A broad survey of industrialized areas of the Strait of Georgia region was conducted in 1998, and a subsequent survey of working harbours in 2004. Samples from 1998 were analyzed for polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides, and polychlorinated dioxins (PCDDs) and furans (PCDFs), while in 2004, chemistry was confined to summation operatorPCBs and OC pesticides. Concentrations of OC pesticides were low in both years, with only dichlorodiphenyldichloroethylene (DDE; range: 0.01-2.12 mg/kg lw) and hexachlorocyclobenzene (HCB; range: 0.003-0.25 mg/kg lw) detected in all samples. In 1998, octachlorodibenzo-p-dioxin (OCDD) and other higher chlorinated PCDD/Fs were found in most samples, with OCDD ranging from 120 ng/kg lw in Clayoquot Sound to 19,100 ng/kg lw in a pooled sample from two latrines in Nanaimo. PCBs were present in all samples. In 1998 geometric mean concentrations of the sum of 59 PCB congeners ranged from 0.49 mg/kg lw in Nanaimo to 12.3 mg/kg lw in Victoria Harbour. Six years later, mean summation operatorPCBs remained elevated (geometric mean 9.5 mg/kg lw) in Victoria Harbour. Geometric mean concentrations of summation operatorPCBs from Victoria Harbour in 1998 and 2004 were >9 mg/kg lw, a published adverse effect level for reproduction. At some latrines in both Victoria and Esquimalt Harbours, concentrations of TCDD-toxic equivalents exceeded 1500 ng/kg lw, a value for health effects in otters that we derived using published information. As shown in previous studies, analysis of scats provides an efficient and non-intrusive approach to assessing contaminant threats to otter populations, and to documenting spatial trends in residues. PMID:18433835

Elliott, John E; Guertin, Daniel A; Balke, Jennifer M E

2008-07-01

349

Distribution of Endophytic Bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. from Soils Contaminated by Polycyclic Aromatic Hydrocarbons  

PubMed Central

The distributions of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. grown in soils contaminated with different levels of polycyclic aromatic hydrocarbons (PAHs) were investigated with polymerase chain reaction followed by denaturing gradient gel electrophoresis technology (PCR-DGGE) and cultivation methods. Twelve types of PAHs, at concentrations varying from 0.16 to 180 mg·kg?1, were observed in the roots and shoots of the two plants. The total PAH concentrations in Alopecurus aequalis Sobol obtained from three different PAH-contaminated stations were 184, 197, and 304 mg·kg?1, and the total PAH concentrations in Oxalis corniculata L. were 251, 346, and 600 mg·kg?1, respectively. The PCR-DGGE results showed that the endophytic bacterial communities in the roots and shoots of the two plants were quite different, although most bacteria belonged to Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. A total of 68 endophytic bacterial strains were isolated from different tissues of the two plants and classified into three phyla: Firmicutes, Proteobacteria and Bacteroidetes. In both plants, Bacillus spp. and Pseudomonas spp. were the dominant cultivable populations. With an increase in the PAH pollution level, the diversity and distribution of endophytic bacteria in the two plants changed correspondingly, and the number of cultivable endophytic bacterial strains decreased rapidly. Testing of the isolated endophytic bacteria for tolerance to each type of PAH showed that most isolates could grow well on Luria-Bertani media in the presence of different PAHs, and some isolates were able to grow rapidly on a mineral salt medium with a single PAH as the sole carbon and energy source, indicating that these strains may have the potential to degrade PAHs in plants. This research provides the first insight into the characteristics of endophytic bacterial populations under different PAH pollution levels and provides a species resource for the isolation of PAH-degrading endophytic bacteria. PMID:24358247

Peng, Anping; Liu, Juan; Gao, Yanzheng; Chen, Zeyou

2013-01-01

350

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

USGS Publications Warehouse

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

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

2006-01-01

351

Geochemical assessment of gaseous hydrocarbons: mixing of bacterial and thermogenic methane in the deep subsurface petroleum system, Gulf of Mexico continental slope  

E-print Network

petroleum system may have been swept by migrating fluids at >4 km, and then charged both vents (GC 185, GC 233 and GC 286) at the seafloor and reservoirs in the deep subsurface. The volume of bacterial methane from geologically significant depth in rapidly...

Ozgul, Ercin

2004-09-30

352

Diversity and distribution of anaeromyxobacter strains in a uranium-contaminated subsurface environment with a nonuniform groundwater flow.  

PubMed

Versaphilic Anaeromyxobacter dehalogenans strains implicated in hexavalent uranium reduction and immobilization are present in the fractured saprolite subsurface environment at the U.S. Department of Energy Integrated Field-Scale Subsurface Research Challenge (IFC) site near Oak Ridge, TN. To provide insight into the in situ distribution of Anaeromyxobacter strains in this system with a nonuniform groundwater flow, 16S rRNA gene-targeted primers and linear hybridization (TaqMan) probes were designed for Oak Ridge IFC Anaeromyxobacter isolates FRC-D1 and FRC-W, along with an Anaeromyxobacter genus-targeted probe and primer set. Multiplex quantitative real-time PCR (mqPCR) was applied to samples collected from Oak Ridge IFC site areas 1 and 3, which are not connected by the primary groundwater flow paths; however, transport between them through cross-plane fractures is hypothesized. Strain FRC-W accounted for more than 10% of the total quantifiable Anaeromyxobacter community in area 1 soils, while strain FRC-D1 was not detected. In FeOOH-amended enrichment cultures derived from area 1 site materials, strain FRC-D1 accounted for 30 to 90% of the total Anaeromyxobacter community, demonstrating that this strain was present in situ in area 1. The area 3 total Anaeromyxobacter abundance exceeded that of area 1 by 3 to 5 orders of magnitude, but neither strain FRC-W- nor FRC-D1-like sequences were quantifiable in any of the 33 area 3 groundwater or sediment samples tested. The Anaeromyxobacter community in area 3 increased from <10(5) cells/g sediment outside the ethanol biostimulation treatment zone to 10(8) cells/g sediment near the injection well, and 16S rRNA gene clone library analysis revealed that representatives of a novel phylogenetic cluster dominated the area 3 Anaeromyxobacter community inside the treatment loop. The combined applications of genus- and strain-level mqPCR approaches along with clone libraries provided novel information on patterns of microbial variability within a bacterial group relevant to uranium bioremediation. PMID:19346346

Thomas, Sara H; Padilla-Crespo, Elizabeth; Jardine, Phillip M; Sanford, Robert A; Löffler, Frank E

2009-06-01

353

Diversity and Distribution of Anaeromyxobacter Strains in a Uranium-Contaminated Subsurface Environment with a Nonuniform Groundwater Flow? †  

PubMed Central

Versaphilic Anaeromyxobacter dehalogenans strains implicated in hexavalent uranium reduction and immobilization are present in the fractured saprolite subsurface environment at the U.S. Department of Energy Integrated Field-Scale Subsurface Research Challenge (IFC) site near Oak Ridge, TN. To provide insight into the in situ distribution of Anaeromyxobacter strains in this system with a nonuniform groundwater flow, 16S rRNA gene-targeted primers and linear hybridization (TaqMan) probes were designed for Oak Ridge IFC Anaeromyxobacter isolates FRC-D1 and FRC-W, along with an Anaeromyxobacter genus-targeted probe and primer set. Multiplex quantitative real-time PCR (mqPCR) was applied to samples collected from Oak Ridge IFC site areas 1 and 3, which are not connected by the primary groundwater flow paths; however, transport between them through cross-plane fractures is hypothesized. Strain FRC-W accounted for more than 10% of the total quantifiable Anaeromyxobacter community in area 1 soils, while strain FRC-D1 was not detected. In FeOOH-amended enrichment cultures derived from area 1 site materials, strain FRC-D1 accounted for 30 to 90% of the total Anaeromyxobacter community, demonstrating that this strain was present in situ in area 1. The area 3 total Anaeromyxobacter abundance exceeded that of area 1 by 3 to 5 orders of magnitude, but neither strain FRC-W- nor FRC-D1-like sequences were quantifiable in any of the 33 area 3 groundwater or sediment samples tested. The Anaeromyxobacter community in area 3 increased from <105 cells/g sediment outside the ethanol biostimulation treatment zone to 108 cells/g sediment near the injection well, and 16S rRNA gene clone library analysis revealed that representatives of a novel phylogenetic cluster dominated the area 3 Anaeromyxobacter community inside the treatment loop. The combined applications of genus- and strain-level mqPCR approaches along with clone libraries provided novel information on patterns of microbial variability within a bacterial group relevant to uranium bioremediation. PMID:19346346

Thomas, Sara H.; Padilla-Crespo, Elizabeth; Jardine, Phillip M.; Sanford, Robert A.; Löffler, Frank E.

2009-01-01

354

[Study on degradation of polycyclic aromatic hydrocarbons (PAHs) with different additional carbon sources in aged contaminated soil].  

PubMed

This study was conducted with different additional carbon sources (such as: glucose, DL-malic acid, citrate, urea and ammonium acetate) to elucidate the degradation of polycyclic aromatic hydrocarbons (PAHs) in aged contaminated soil under an indoor simulation experiment. The results showed that the quantity of CO2 emission in different additional carbon sources treatments was obviously much more than that of check treatment in the first week, and the quantity of CO2 emission in DL-malic acid treatment was the largest. The average CO2 production decreased in an order urea > glucose approximately citrate approximately DL-malic acid approximately ammonium acetate > check. Meanwhile, the amount of volatized PAHs in applied carbon sources treatments was significantly less than that in check treatment. The amount of three volatized PAHs decreased in an order phenanthrene > fluoranthene > benzo(b)fluoranthene. Compared with the check treatment, the average degradation rates of the three PAHs were significantly augmented in the supplied carbon sources treatments, in which rates of the three PAHs were much higher in DL-malic acid and urea treatments than those in other treatments. The largest proportion of residual was benzo(b)fluoranthene (from 72% to 81%) among three PAHs compounds, followed by fluoranthene (from 53% to 70% ) and phenanthrene (from 27% to 44%). PMID:22509608

Yin, Chun-Qin; Jiang, Xin; Wang, Fang; Wang, Cong-Ying

2012-02-01

355

Mitogen induced proliferative responses of lymphocytes from spot (Leiostomus xanthurus) exposed to polycyclic aromatic hydrocarbon contaminated environments  

SciTech Connect

The marine fish spot, Leiostomus xanthurus, was collected from five sites in the lower Chesapeake Bay system representing a gradient of sediment polycyclic aromatic hydrocarbon (PAH) concentrations. The proliferative responses to mitogens by anterior kidney lymphocytes were assessed using (3H)-thymidine uptake by replicating DNA. The data show two different mitogen-dependent lymphocytic responses as the sediment PAH levels increase at the sampling sites; a suppression of the response to the T cell mitogens, concanavalin A (Con A) and phytohemagglutinin, and a sharp augmentation of the response to B cell mitogen, lipopolysaccharide (LPS), as well as to poke weed mitogen and peanut agglutinin. The magnitude of the lymphoproliferative responses correlated strongly with the total sediment PAH concentrations (r2 greater than 0.8). A similar correlation was also observed with 15 selected individual PAH compounds regardless of their molecular weights. By maintaining the fish in clean York River water for up to 24 weeks, it was possible to reverse the augmented proliferative responses to LPS of fish from all sampling sites and to increase the reduced responses to Con A, in fish from three sites, and partially in two sites where sediments were highly contaminated with PAH. These results suggest that the proliferative responses of fish lymphocytes to mitogens may be a potentially sensitive biomarker of exposure to, and effects of xenobiotics.

Faisal, M.; Marzouk, M.S.; Smith, C.L.; Huggett, R.J. (Virginia Institute of Marine Science, School of Marine Science, College of William Mary, Gloucester Point (United States))

1991-01-01

356

Pyrosequence analyses of bacterial communities during simulated in situ bioremediation of polycyclic aromatic hydrocarbon-contaminated soil  

PubMed Central

Barcoded amplicon pyrosequencing was used to generate libraries of partial 16S rRNA genes from two columns designed to simulate in situ bioremediation of polycyclic aromatic hydrocarbons (PAHs) in weathered, contaminated soil. Both columns received a continuous flow of artificial groundwater but one of the columns additionally tested the impact of biostimulation with oxygen and inorganic nutrients on indigenous soil bacterial communities. The penetration of oxygen to previously anoxic regions of the columns resulted in the most significant community changes. PAH-degrading bacteria previously determined by stable-isotope probing (SIP) of the untreated soil generally responded negatively to the treatment conditions, with only members of the Acidovorax and a group of uncharacterized PAH-degrading Gammaproteobacteria maintaining a significant presence in the columns. Additional groups of sequences associated with the Betaproteobacterial family Rhodocyclaceae (including those associated with PAH degradation in other soils), and the Thiobacillus, Thermomonas, and Bradyrhizobium genera were also present in high abundance in the biostimulated column. Similar community responses were previously observed during biostimulated ex situ treatment of the same soil in aerobic, slurry-phase bioreactors. While the low relative abundance of many SIP-determined groups in the column libraries may be a reflection of the slow removal of PAHs in that system, the similar response of known PAH-degraders in a higher-rate bioreactor system suggests that alternative PAH-degrading bacteria, unidentified by SIP of the untreated soil, may also be enriched in engineered systems. PMID:23132343

Singleton, David R.; Jones, Maiysha D.; Richardson, Stephen D.; Aitken, Michael D.

2012-01-01

357

Pyrosequence analyses of bacterial communities during simulated in situ bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.  

PubMed

Barcoded amplicon pyrosequencing was used to generate libraries of partial 16S rRNA genes from two columns designed to simulate in situ bioremediation of polycyclic aromatic hydrocarbons (PAHs) in weathered, contaminated soil. Both columns received a continuous flow of artificial groundwater but one of the columns additionally tested the impact of biostimulation with oxygen and inorganic nutrients on indigenous soil bacterial communities. The penetration of oxygen to previously anoxic regions of the columns resulted in the most significant community changes. PAH-degrading bacteria previously determined by stable-isotope probing (SIP) of the untreated soil generally responded negatively to the treatment conditions, with only members of the Acidovorax and a group of uncharacterized PAH-degrading Gammaproteobacteria maintaining a significant presence in the columns. Additional groups of sequences associated with the Betaproteobacterial family Rhodocyclaceae (including those associated with PAH degradation in other soils), and the Thiobacillus, Thermomonas, and Bradyrhizobium genera were also present in high abundance in the biostimulated column. Similar community responses were previously observed during biostimulated ex situ treatment of the same soil in aerobic, slurry-phase bioreactors. While the low relative abundance of many SIP-determined groups in the column libraries may be a reflection of the slow removal of PAHs in that system, the similar response of known PAH degraders in a higher-rate bioreactor system suggests that alternative PAH-degrading bacteria, unidentified by SIP of the untreated soil, may also be enriched in engineered systems. PMID:23132343

Singleton, David R; Jones, Maiysha D; Richardson, Stephen D; Aitken, Michael D

2013-09-01

358

Linking Specific Heterotrophic Bacterial Populations to Bioreduction of Uranium and Nitrate in Contaminated Subsurface Sediments by Using Stable Isotope Probing?†  

PubMed Central

Shifts in terminal electron-accepting processes during biostimulation of uranium-contaminated sediments were linked to the composition of stimulated microbial populations using DNA-based stable isotope probing. Nitrate reduction preceded U(VI) and Fe(III) reduction in [13C]ethanol-amended microcosms. The predominant, active denitrifying microbial groups were identified as members of the Betaproteobacteria, whereas Actinobacteria dominated under metal-reducing conditions. PMID:21948831

Akob, Denise M.; Kerkhof, Lee; Küsel, Kirsten; Watson, David B.; Palumbo, Anthony V.; Kostka, Joel E.

2011-01-01

359

Linking specific heterotrophic bacterial populations to bioreduction of uranium and nitrate using stable isotope probing in contaminated subsurface sediments  

SciTech Connect

Shifts in terminal electron-accepting processes during biostimulation of uranium-contaminated sediments were linked to the composition of stimulated microbial populations using DNA-based stable isotope probing. Nitrate reduction preceded U(VI) and Fe(III) reduction in [{sup 13}C]ethanol-amended microcosms. The predominant, active denitrifying microbial groups were identified as members of the Betaproteobacteria, whereas Actinobacteria dominated under metal-reducing conditions.

Akob, Denise M. [Florida State University; Kerkhof, Lee [Rutgers University; Kusel, Kirsten [Friedrich Schiller University Jena, Jena Germany; Watson, David B [ORNL; Palumbo, Anthony Vito [ORNL; Kostka, Joel [Florida State University

2011-01-01

360

Effects of Mixing Low Amounts of Orange Peel (Citrus reticulata) with Hydrocarbon-Contaminated Soil in Solid Culture to Promote Remediation  

Microsoft Academic Search

The effect of mixing low amounts of orange peel (Citrus reticulata) with a soil contaminated with hydrocarbons (58,000 mg kg soil) for promoting the soil remediation in solid culture was studied. The experimental design was established in solid culture at soil\\/orange (Citrus reticulata) peel ratios of 100:0, 98:2, 96:4, 94:6 and 92:8, at 30% humidity and a C:N:P ratio of

A. ROLDÁN-MARTÍN; F. ESPARZA-GARCÍA; G. CALVA-CALVA; R. RODRÍGUEZ-VÁZquez

2006-01-01

361

The influence of different temperature programmes on the bioremediation of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated soil by in-vessel composting  

Microsoft Academic Search

The biodegradation of 16 US. EPA-listed polycyclic aromatic hydrocarbons (?PAHs), with accompanying humification and microbial community structure changes during simulated in-vessel composting-bioremediation of an aged coal-tar-contaminated soil amended with green waste were studied over 56 days. The experimental design compared one constant temperature profile (TC=38°C) with three variable temperature profiles (TP1, TP2 and TP3), including treatment at 70°C to comply

Blanca Antizar-Ladislao; Angus J. Beck; Katarina Spanova; Joe Lopez-Real; Nicholas J. Russell

2007-01-01

362

Characterization of biochemical properties and biological activities of biosurfactants produced by Pseudomonas aeruginosa mucoid and non-mucoid strains isolated from hydrocarbon-contaminated soil samples  

Microsoft Academic Search

Biochemical and pharmacological properties of biosurfactants produced at 45°C temperature by Pseudomonas aeruginosa mucoid (M) and non-mucoid (NM) strains, isolated from hydrocarbon-contaminated soil samples, were characterized. Both the strains secreted appreciable amount of biosurfactants (5.0–6.5 g\\/l), responsible for the reduction of surface tension of the medium from 68 to 29±0.5 mN\\/m post 96 h of growth. Maximum yield of biosurfactants was observed following

Kishore Das; Ashis K. Mukherjee

2005-01-01

363

Growth of inoculated white-rot fungi and their interactions with the bacterial community in soil contaminated with polycyclic aromatic hydrocarbons, as measured by phospholipid fatty acids  

Microsoft Academic Search

The objective of this study was to examine the possibility of measuring the growth of three white-rot fungi in soil contaminated with polycyclic aromatic hydrocarbons (PAHs), by estimating the soil levels of the phospholipid fatty acid (PLFA) 18:2?6,9. The effect of the fungi on the PAH concentration and on the indigenous bacterial population in the soil was monitored. As shown

B. E Andersson; L Welinder; P. A Olsson; S Olsson; T Henrysson

2000-01-01

364

Environmental Analysis of Endocrine Disrupting Effects from Hydrocarbon Contaminants in the Ecosystem - Final Report - 09/15/1996 - 09/14/2000  

SciTech Connect

The three major components of the research included: (a) a biotechnology based screening system to identify potential hormone mimics and antagonists (b) an animal screening system to identify biomarkers of endocrine effects and (c) a literature review to identify compounds at various DOE sites that are potential endocrine disruptors. Species of particular interest in this study were those that 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 human inhabitants. The objective of this basic research is to characterize the potential of common hydrocarbon contaminants in ecosystems to act as endocrine disruptors. Although the endocrine disrupting effects of contaminants such as dioxin and PCBs have been well characterized in both animals and humans, little is known about the capacities of other hydrocarbon contaminants to act as endocrine disruptors. Results obtained from this research project have provided information on endocrine disrupting contaminants for consideration in DOE's risk analyses for determining clean-up levels and priorities at contaminated DOE sites.

McLachlan, John A.

2000-09-14

365

Functional Diversity and Electron Donor Dependence of Microbial Populations Capable of U(VI) Reduction in Radionuclide-Contaminated Subsurface Sediments?  

PubMed Central

In order to elucidate the potential mechanisms of U(VI) reduction for the optimization of bioremediation strategies, the structure-function relationships of microbial communities were investigated in microcosms of subsurface materials cocontaminated with radionuclides and nitrate. A polyphasic approach was used to assess the functional diversity of microbial populations likely to catalyze electron flow under conditions proposed for in situ uranium bioremediation. The addition of ethanol and glucose as supplemental electron donors stimulated microbial nitrate and Fe(III) reduction as the predominant terminal electron-accepting processes (TEAPs). U(VI), Fe(III), and sulfate reduction overlapped in the glucose treatment, whereas U(VI) reduction was concurrent with sulfate reduction but preceded Fe(III) reduction in the ethanol treatments. Phyllosilicate clays were shown to be the major source of Fe(III) for microbial respiration by using variable-temperature Mössbauer spectroscopy. Nitrate- and Fe(III)-reducing bacteria (FeRB) were abundant throughout the shifts in TEAPs observed in biostimulated microcosms and were affiliated with the genera Geobacter, Tolumonas, Clostridium, Arthrobacter, Dechloromonas, and Pseudomonas. Up to two orders of magnitude higher counts of FeRB and enhanced U(VI) removal were observed in ethanol-amended treatments compared to the results in glucose-amended treatments. Quantification of citrate synthase (gltA) levels demonstrated a stimulation of Geobacteraceae activity during metal reduction in carbon-amended microcosms, with the highest expression observed in the glucose treatment. Phylogenetic analysis indicated that the active FeRB share high sequence identity with Geobacteraceae members cultivated from contaminated subsurface environments. Our results show that the functional diversity of populations capable of U(VI) reduction is dependent upon the choice of electron donor. PMID:18378664

Akob, Denise M.; Mills, Heath J.; Gihring, Thomas M.; Kerkhof, Lee; Stucki, Joseph W.; Anastácio, Alexandre S.; Chin, Kuk-Jeong; Küsel, Kirsten; Palumbo, Anthony V.; Watson, David B.; Kostka, Joel E.

2008-01-01

366

Variations in the abundance and identity of class II aromatic ring-hydroxylating dioxygenase genes in groundwater at an aromatic hydrocarbon-contaminated site.  

PubMed

The abundance of genes encoding aromatic ring-hydroxylating dioxygenases (RHDs) in the groundwater at an aromatic hydrocarbon-contaminated landfill near Sydney, Australia, was determined by quantitative DNA-DNA hybridization using class II RHD genes as probes. There were marked differences in hybridization signal intensity against DNA extracted from the groundwater at seven different locations across this heterogeneous site. This was interpreted as indicating variation in RHD gene abundance. Clone libraries of polymerase chain reaction (PCR)-amplified RHD gene fragments were constructed from DNA from each of the groundwater samples. The libraries from the samples with greater RHD gene abundance were dominated by a group of bacterial class II RHD genes, designated the S-cluster, that has yet to be found in cultured isolates. These groundwater samples contained no detectable petroleum hydrocarbons. A second group of class II RHD gene sequences, designated the T-cluster, dominated RHD gene clone libraries prepared from groundwater samples that contained detectable levels of total petroleum and aromatic hydrocarbons but lower RHD gene abundance. The hosts and in situ expression of these novel genes, and the substrates of the enzymes they encode, remain unknown. The scarcity of genes from known aromatic hydrocarbon-degrading bacteria and the numerical dominance of the novel genes suggest that the hosts of these novel genes may play an important role in aromatic hydrocarbon degradation at this site. PMID:15643944

Taylor, Paul M; Janssen, Peter H

2005-01-01

367

Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site  

SciTech Connect

Natural selection in highly radioactive waste sites may yield bacteria with favorable bioremediating characteristics. However, until recently the microbial ecology of such environments has remained unexplored because of the high costs and technical complexities associated with extracting and characterizing samples from such sites. We have examined the bacterial ecology within radioactive sediments from a high-level nuclear waste plume in the vadose zone on the DOE?s Hanford Site in south-central Washington state (Fredrickson et al, 2004). Manganese-dependent, radiation resistant bacteria have been isolated from this contaminated site including the highly Mn-dependent Deinococcus and Arthrobacter spp.

Daly, Michael J.

2005-06-01

368

Modeling geochemical reactions in contaminated aquifers: Transformation of aromatic hydrocarbons by bacteria and concomitant inorganic chemical evolution  

Microsoft Academic Search

The physical environment of groundwater flow and contaminant transport, the chemical environment of contaminant-water-rock interactions, and the biological environment of microbially mediated processes act to influence the fate of groundwater contaminants in a complex and interconnected way. Prediction of the chemical evolution of groundwater in the complex environment of a contaminated aquifer is necessary to address environmental contamination and remediation

J. S. Herman; W. R. Kelly; A. L. Mills; G. M. Hornberger

1992-01-01

369

Environmental projects. Volume 5, part 1: Study of subsurface contamination. Part 2: Guide to implement environmental compliance programs  

NASA Technical Reports Server (NTRS)

In support of the national goal for the preservation of the environment and the protection of human health and safety, NASA, the Jet Propulsion Laboratory, and the Goldstone Deep Space Communications Complex have adopted the position that their operating installations shall maintain a high level of compliance in regard to regulations concerning environmental hazards. An investigation carried out by Engineering Science, Inc. focused on possible underground contamination that may have resulted from leaks and/or spills from storage facilities at the Goldstone Communications Complex. It also involved the cleanup of a non-hazardous waste dumpsite at the Mojave Base Site at the Goldstone complex. The report also includes details of the management duties and responsibilities needed to maintain compliance with environmental laws and regulations.

Bengelsdorf, I.

1988-01-01

370

SMART 3D SUBSURFACE CONTAMINANT CHARACTERIZATION AT THE BGRR DECOMMISSIONING PROJECT. ACCELERATED SITE TECHNOLOGY DEPLOYMENT COST AND PERFORMANCE REPORT.  

SciTech Connect

The BGRR was the world's first nuclear reactor dedicated to the peaceful exploration of atomic energy. The reactor pile consisted of a 700-ton, 25-foot cube of graphite fueled by uranium. A total of 1,369 fuel channels were available with roughly half in use at any given time. Insertion and removal of boron steel control rods controlled reactor power levels. One or more of five fans powered air-cooling. Air was brought in through two filtered plenums, flowed through and around the reactor core, through an exhaust duct containing filters, and finally out through the 320-foot high exhaust stack. Spent fuel was temporarily stored in the spent-fuel canal, and then sent to the Department of Energy's Savannah River Site (SRS). Access to the canal for removing spent fuel was through the Canal House (Building 709). The BGRR ceased operation in 1968 and was placed in a shutdown mode in which all fuel was removed and sent to SRS. Penetrations in the biological shield around the graphite cube and fuel channels were sealed. The final decontamination and decommissioning (D and D) process was initiated in 1999 and is scheduled for completion in 2005. An accelerated schedule was developed that combines characterization with removal actions for the various systems and structures. Before D and D work on a section of the BGRR facility begins, contaminant characterization is conducted to determine the types and amounts of contaminants present. The data are then used for project planning, including decisions affecting the extent of removal, waste designation, and health and safety plans.

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

2001-12-01

371

Escherichia coli contamination and health aspects of soil and tomatoes (Solanum lycopersicum L.) subsurface drip irrigated with on-site treated domestic wastewater.  

PubMed

Faecal contamination of soil and tomatoes irrigated by sprinkler as well as surface and subsurface drip irrigation with treated domestic wastewater were compared in 2007 and 2008 at experimental sites in Crete and Italy. Wastewater was treated by Membrane Bio Reactor (MBR) technology, gravel filtration or UV-treatment before used for irrigation. Irrigation water, soil and tomato samples were collected during two cropping seasons and enumerated for the faecal indicator bacterium Escherichia coli and helminth eggs. The study found elevated levels of E. coli in irrigation water (mean: Italy 1753 cell forming unit (cfu) per 100 ml and Crete 488 cfu per 100 ml) and low concentrations of E. coli in soil (mean: Italy 95 cfu g(-1) and Crete 33 cfu g(-1)). Only two out of 84 tomato samples in Crete contained E. coli (mean: 2700 cfu g(-1)) while tomatoes from Italy were free of E. coli. No helminth eggs were found in the irrigation water or on the tomatoes from Crete. Two tomato samples out of 36 from Italy were contaminated by helminth eggs (mean: 0.18 eggs g(-1)) and had been irrigated with treated wastewater and tap water, respectively. Pulsed Field Gel Electrophoresis DNA fingerprints of E. coli collected during 2008 showed no identical pattern between water and soil isolates which indicates contribution from other environmental sources with E. coli, e.g. wildlife. A quantitative microbial risk assessment (QMRA) model with Monte Carlo simulations adopted by the World Health Organization (WHO) found the use of tap water and treated wastewater to be associated with risks that exceed permissible limits as proposed by the WHO (1.0 × 10(-3) disease risk per person per year) for the accidental ingestion of irrigated soil by farmers (Crete: 0.67 pppy and Italy: 1.0 pppy). The QMRA found that the consumption of tomatoes in Italy was deemed to be safe while permissible limits were exceeded in Crete (1.0 pppy). Overall the quality of tomatoes was safe for human consumption since the disease risk found on Crete was based on only two contaminated tomato samples. It is a fundamental limitation of the WHO QMRA model that it is not based on actual pathogen numbers, but rather on numbers of E. coli converted to estimated pathogen numbers, since it is widely accepted that there is poor correlation between E. coli and viral and parasite pathogens. Our findings also stress the importance of the external environment, typically wildlife, as sources of faecal contamination. PMID:22944202

Forslund, A; Ensink, J H J; Markussen, B; Battilani, A; Psarras, G; Gola, S; Sandei, L; Fletcher, T; Dalsgaard, A

2012-11-15

372

Role of natural attenuation, phytoremediation and hybrid technologies in the remediation of a refinery soil with old/recent petroleum hydrocarbons contamination.  

PubMed

Within a search for a biological remediation technology to remove petroleum hydrocarbons (PHC) from a contaminated soil from a refinery, the potential of monitored natural attenuation (MNA) was compared with the use of transplants of Cortaderia selloana both in the absence and in the presence of soil amendments. After 31 months of experiments, MNA was effective in removing most of the recent PHC contamination (50% of the initial total contamination) at 5-20 cm depth. The presence of weathered contamination explains the existence of an established community of PHC degraders, as can be inferred by the most probable number technique. C. selloana, in its turn, showed capacity to mobilize the most recalcitrant fraction of PHC to its roots, nevertheless masking its remediation capacity. The use of a hybrid technology (C. selloana together with treatments with a surfactant and a bioaugmentation product) improved the removal of PHC at 15-20 cm depth, the presence of C. selloana facilitating the migration of additives into the deeper layers of soil, which can be considered a secondary but positive role of the plant. In the surface soil layer, which was exposed to both microorganisms and the atmosphere, a further 20% of weathered PHC contamination disappeared (70% total removal) as a result of photo- and chemical degradation. Periodic revolving of the soil, like tillage, to expose all the contaminated soil to the atmosphere will therefore be a reliable option for reducing the contamination of the refinery soil if conditions (space and equipment) permit this operation. PMID:23240204

Couto, Maria Nazaré P F S; Pinto, Dorabela; Basto, M Clara P; Vasconcelos, Teresa S D

2012-09-01

373

Parameters describing nonequilibrium transport of polycyclic aromatic hydrocarbons through contaminated soil columns: estimability analysis, correlation, and optimization.  

PubMed

The soil and groundwater at former industrial sites polluted by polycyclic aromatic hydrocarbons (PAHs) produce a very challenging environmental issue. The description of PAH transport by means of mathematical models is therefore needed for risk assessment and remediation strategies at these sites. Due to the complexity of release kinetics and transport behavior of the PAHs in the aged contaminated soils, their transport is usually evaluated at the laboratory scale. Transport parameters are then estimated from the experimental data via the inverse method. To better assess the uncertainty of optimized parameters, an estimability method was applied to firstly investigate the information content of experimental data and the possible correlations among parameters in the two-site sorption model. These works were based on the concentrations of three PAHs, Acenaphthene (ACE), Fluoranthene (FLA) and Pyrene (PYR), in the leaching solutions of the experiments under saturated and unsaturated flow conditions. The estimability results showed that the experiment under unsaturated flow conditions contained more information content for estimating four transport parameters than under the saturated one. In addition, whatever the experimental conditions for all three PAHs the fraction of sites with instantaneous sorption, f, was highly correlated with the adsorption distribution coefficient, Kd. The very strong correlation between the two parameters f and Kd suggests that they should not be simultaneously calibrated. Transport parameters were optimized using HYDRUS-1D software with different scenarios based on the estimability analysis results. The optimization results were not always reliable, especially in the case of the experiment under saturated flow conditions because of its low information content. In addition, the estimation of transport parameters became very uncertain if two parameters f and Kd were optimized simultaneously. The findings of the current work can suggest some reasons behind the optimization problems and indicate the type of experimental information additionally needed for parameter identification. To overcome the parameterization issues of PAH non-equilibrium transport, the experimental design, timescale, and model refinement need further improvement. The conclusions presented in this paper are not limited necessarily to PAHs, but may also be relevant to other organic contaminants with similar leaching behavior. PMID:24522237

Ngo, Viet V; Michel, Julien; Gujisaite, Valérie; Latifi, Abderrazak; Simonnot, Marie-Odile

2014-03-01

374

Bio-removal of mixture of benzene, toluene, ethylbenzene, and xylenes/total petroleum hydrocarbons/trichloroethylene from contaminated water.  

PubMed

Four pure cultures were isolated from soil samples potentially contaminated with gasoline compounds either at a construction site near a gas station in Fai Chi Kei, Macau SAR or in the northern parts of China (Beijing, and Hebei and Shandong). The effects of different concentrations of benzene, toluene, ethylbenzene, and three isomers (ortho-, meta-, and para-) of xylene (BTEX), total petroleum hydrocarbons (TPH), and trichloroethylene (TCE), when they were present in mixtures, on the bio-removal efficiencies of microbial isolates were investigated, together with their interactions during the bio-removal process. When the isolates were tested for the BTEX (50-350 mg/L)/TPH (2000 mg/L) mixture, BTEoX in BTEoX/TPH mixture was shown with higher bio-removal efficiencies, while BTEmX in BTEmX/TPH mixture was shown with the lowest, regardless of isolates. The TPH in BTEmX/TPH mixture, on the other hand, were generally shown with higher bio-removal efficiencies compared to when TPH mixed with BTEoX and BTEpX. When these BTEX mixtures (at 350 mg/L) were present with TCE (5-50 mg/L), the stimulatory effect of TCE toward BTEoX bio-removal was observed for BTEoX/TCE mixture, while the inhibitory effect of TCE toward BTEmX for BTEmX/TCE mixture. The bio-removal efficiency for TPH was shown lower in TPH (2000 mg/L)/TCE (5-50 mg/L) mixtures compared to TPH present alone, implying the inhibitory effect of TCE toward TPH bio-removal. For the mixture of BTEX (417 mg/L), TPH (2000 mg/L) along with TCE (5-50 mg/L), TCE was shown co-metabolically removed more efficiently at 15 mg/L, probably utilizing BTEX and/or TPH as primary substrates. PMID:19803079

Shim, Hojae; Ma, Wei; Lin, Aijun; Chan, Kaicho

2009-01-01

375

Polycyclic Aromatic Hydrocarbons and n-alkanes in sediments of the Upper Scheldt River Basin: contamination levels and source apportionment  

E-print Network

Polycyclic Aromatic Hydrocarbons and n-alkanes in sediments of the Upper Scheldt River Basin River at Wervik and the Espierre Canal), were analysed for n-alkanes and polycyclic aromatic hydrocarbons (PAHs). Total n-alkane and PAH concentrations in all the sampled cores ranged from 2.8 to 29 mg kg

Boyer, Edmond

376

Benthic foraminifera as tools in interpretation of subsurface hydrocarbon fluid flow at Veslemøy High and Hola-Vesterålen areas of the Barents Sea.  

NASA Astrophysics Data System (ADS)

Relatively few studies have focused on high-latitude benthic foraminifera related to hydrocarbon seeps. In this study, we present micropaleontological data from 8 gravity cores from the Veslemøy High and 4 surface sediments (0-1cm) from Hola-Vesterålen, Norway. The study of hydrocarbon impregnation and its effect on benthic foraminfera was conducted on selected sediment samples from the calcium-rich Holocene sediments of the Veslemøy High. The assemblage of foraminifera have been identified from three regional clusters. Cluster I and II are dominated by benthic foraminifera Buccella, Cassidulina, Cibicides, Discopulvinulina, Epistominella, Pullenia and Trifarina. Cluster III is distinct with an elevated abundance of Cassidulina, Cibicides and Trifarina with significant (>5 %) occurrence of Nonionella and Uvigerina. There is no apparent dissolution on the preserved foraminifera. However, there can be differential dissolution or destruction of the more fragile (thinner-walled test) species like Epistominella, Nonionella or Pullenia while leaving behind over-represented species like Cibicides or Trifarina (both preferring coarse grained, high energy areas that can withstand permanent winnowing and redeposition) with higher preservation potential. Also, Cluster III is placed right over the underlying fault line with shallow seep-indications and thus the fluids released may have induced the dissolution of the fragile species. Moreover, the significant occurrence of benthic foraminifera Nonionella auris, and Uvigerina peregrina, in Holocene deposits of Cluster III may be indicative of environments influenced by hydrocarbon migration to the seafloor. Previous studies have reported active natural hydrocarbon seepage in the Hola area and the stable carbon and hydrogen isotopic composition of methane in the sediments suggests a predominantly thermogenic methane source. The seep-assemblage is composed of Cibicides (~60%), Cassidulina, Discanomalina, Textularia and Trifarina. Discanomalina coronata is an indicator species to identify active cold-water coral mounds. A negative carbon isotopic signal is recorded by D. coronata in all samples. Seep samples with low diversities also contain deformed individuals of Cibicides lobatulus (3.4-6.5 %), similar to those reported for a gigantic oil spill from a tanker or for environments polluted with heavy metals. However, it is an attached form and thus its test shape is affected by the nature of the substratum. Carbon isotopic signature of the deformed specimens reveal slightly lower values than their undeformed counterparts. One sample from Ullsfjorden was also studied where the assemblage is represented by Bulimina, Cassidulina, Globobulimina, Melonis, Nonionella and Reophax. Infaunal fauna B. marginata, M. barleeanum, and N. labradorica prefer muddy/silty to sandy substrata and high organic matter input, and thrive under suboxic-dysoxic conditions. All species in this assemblage have recorded negative carbon isotopic signal.

Baranwal, Soma; Sauer, Simone; Knies, Jochen; Chand, Shyam; Jensen, Henning; Klug, Martin

2014-05-01

377

Simulation of subsurface biotransformation  

Microsoft Academic Search

Hydrophobic organic contaminants like DDT, Polychlorobiphenyls (PCB's) and polyaromatic hydrocarbons (PAH's), have been detected all over the world. They tend to accumulate in the atmosphere and in the soil as a result of their physical and chemical properties. Breakdown mainly proceeds by (photo)chemical reactions in the atmosphere and via microbial transformation in the soil. Microbial transformation can be viewed as

T. N. P. Bosma

1994-01-01

378

THE RELATIONSHIP OF TOTAL DISSOLVED SOLIDS MEASUREMENTS TO BULK ELECTRICAL CONDUCTIVITY IN AN AQUIFER CONTAMINATED WITH HYDROCARBON  

EPA Science Inventory

A recent conceptual model links high bulk electrical 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 investigated the vertical distributio...

379

Evaluating the effects of bioremediation on genotoxicity of polycyclic aromatic hydrocarbon-contaminated soil using genetically engineered, higher eukaryotic cell lines.  

PubMed

Bioremediation is one of the commonly applied remediation strategies at sites contaminated with polycyclic aromatic hydrocarbons (PAHs). However, remediation goals are typically based on removal of the target contaminants rather than on broader measures related to health risks. We investigated changes in the toxicity and genotoxicity of PAH-contaminated soil from a former manufactured-gas plant site before and after two simulated bioremediation processes: a sequencing batch bioreactor system and a continuous-flow column system. Toxicity and genotoxicity of the residues from solvent extracts of the soil were determined by the chicken DT40 B-lymphocyte isogenic cell line and its DNA-repair-deficient mutants. Although both bioremediation processes significantly removed PAHs from the contaminated soil (bioreactor 69% removal, column 84% removal), bioreactor treatment resulted in an increase in toxicity and genotoxicity over the course of a treatment cycle, whereas long-term column treatment resulted in a decrease in toxicity and genotoxicity. However, when screening with a battery of DT40 mutants for genotoxicity profiling, we found that column treatment induced DNA damage types that were not observed in untreated soil. Toxicity and genotoxicity bioassays can supplement chemical analysis-based risk assessment for contaminated soil when evaluating the efficacy of bioremediation. PMID:22443351

Hu, Jing; Nakamura, Jun; Richardson, Stephen D; Aitken, Michael D

2012-04-17

380

Effect of humic deposit (leonardite) on degradation of semi-volatile and heavy hydrocarbons and soil quality in crude-oil-contaminated soil  

Microsoft Academic Search

In order to investigate the bioremedial potential of humic deposit (leonardite), the effects of the treatments of leonardite\\u000a and a commercial bioaugmentation agent on the degradation of a variety of petroleum hydrocarbons (C13–C31) and soil enzyme\\u000a activities (urease acid-alkaline phosphatase and dehydrogenase) were tested within a soil incubation experiment lasting 120 days.\\u000a Experimentally crude-oil-contaminated soil (2.5%) was regulated to a C:N:P

Oguz Can Turgay; Esin Erayd?n Erdogan; Ayten Karaca

2010-01-01

381

Subsurface Drainage Contribution to Streamflow in Subsurface Drained Agricultural Watersheds  

NASA Astrophysics Data System (ADS)

In intensively subsurface drained agricultural watersheds, subsurface drainage influences both the streamflow pattern and the water quality of the receiving streams. Quantification of subsurface drainage volume may improve flood forecasting, enable estimation of contaminant loading through subsurface drains and assist in identification of target areas for load reduction and water conservation measures. The streamflow in a typical subsurface drained watershed consists of direct runoff (surface and subsurface runoff), drain flow (subsurface drainage) and base flow. During and immediately following storm events, drain flow can be considered part of both direct runoff and base flow, and in between the storms, drain flow can be part of base flow. As a first step, we explore quantifying the subsurface drainage contribution to observed streamflow using traditional hydrograph separation combined with surface runoff estimation. Annual average base flow contribution is estimated using average base flow during the driest two months of the year (August and September), when the drain flow can be considered negligible. The methodology was first evaluated using observations of drain flow from two experimental study sites in the Hoagland watershed in west central Indiana, USA and predictions of total watershed drain flow from a distributed application of the DRAINMOD drainage model. The methodology was then applied to other gauged rivers throughout the Wabash River basin in Indiana and compared to maps of estimated subsurface drainage extent.

Ale, S.; Bowling, L. C.

2010-12-01

382

Comparison of earthworm responses to petroleum hydrocarbon exposure in aged field contaminated soil using traditional ecotoxicity endpoints and 1H NMR-based metabolomics.  

PubMed

(1)H NMR metabolomics and conventional ecotoxicity endpoints were used to examine the response of earthworms exposed to petroleum hydrocarbons (PHCs) in soil samples collected from a site that was contaminated with crude oil from a pipeline failure in the mid-1990s. The conventional ecotoxicity tests showed that the soils were not acutely toxic to earthworms (average survival ? 90%), but some soil samples impaired reproduction endpoints by >50% compared to the field control soil. Additionally, metabolomics revealed significant relationships between earthworm metabolic profiles (collected after 2 or 14 days of exposure) and soil properties including soil PHC concentration. Further comparisons by partial least squares regression revealed a significant relationship between the earthworm metabolomic data (collected after only 2 or 14 days) and the reproduction endpoints (measured after 63 days). Therefore, metabolomic responses measured after short exposure periods may be predictive of chronic, ecologically relevant toxicity endpoints for earthworms exposed to soil contaminants. PMID:23938450

Whitfield Åslund, Melissa; Stephenson, Gladys L; Simpson, André J; Simpson, Myrna J

2013-11-01

383

Effect of subsurface heterogeneity on free-product recovery from unconfined aquifers  

NASA Astrophysics Data System (ADS)

Free-product record system designs for light-hydrocarbon-contaminated sites were investigated to evaluate the effects of subsurface heterogeneity using a vertically integrated three-phase flow model. The input stochastic variable of the areal flow analysis was the log-intrinsic permeability and it was generated using the Turning Band method. The results of a series of hypothetical field-scale simulations showed that subsurface heterogeneity has a substantial effect on free-product recovery predictions. As the heterogeneity increased, the recoverable oil volume decreased and the residual trapped oil volume increased. As the subsurface anisotropy increased, these effects together with free- and total-oil contaminated areas were further enhanced. The use of multiple-stage water pumping was found to be insignificant compared to steady uniform pumping due to reduced recovery efficiency and increased residual oil volume. This observation was opposite to that produced under homogeneous scenarios. The effect of subsurface heterogeneity was enhanced at relatively low water pumping rates. The difference in results produced by homogeneous and heterogeneous simulations was substantial, indicating greater attention should be paid in modeling free-product recovery systems with appropriate subsurface heterogeneity.

Kaluarachchi, Jagath J.

1996-03-01

384

Potential subsurface structures and hydrocarbon reservoirs in the southern Appalachian Basin beneath the Cumberland Plateau and eastern Highland Rim, Tennessee, Kentucky, and southwestern Virginia  

NASA Astrophysics Data System (ADS)

Oil and gas exploration in the southern Appalachian basin is typically concentrated around areas with historically proven reserves and very limited prospecting is conducted elsewhere in the region. To remove possible correlation problems and promote regional prospecting a standardized picking methodology was established in geophysical logs for the Middle Ordovician carbonate lithofacies (Nashville-Stones River Groups). This methodology was then used to correlate the units across Cumberland Plateau of Tennessee, Kentucky, and Virginia, from the Nashville-Jessamine domes to the Clinchport-Whiteoak Mountain thrust in the Valley and Ridge. The same lithofacies may extend in Ohio, Pennsylvania, and New York, suggesting a standardized nomenclature be established. This methodology is key to resolving regional and local structures, and structural trends in this area. To identify deformation probably associated with blind structural trends and producing fields, regional structure contour, trend surface residual anomaly, and isopach maps were constructed using data from 7,639 geophysical logs, 1,960 drill cores, and 433 surface contacts. These maps correlate well with known producing fields and identified a possible decollement in the Chattanooga Shale along with the southern extension of the Rome trough in Tennessee. A geologic model for hydrocarbon emplacement was constructed to accommodate all the available structural and petroleum information. The model illustrates a proposed decollement soled in the Chattanooga Shale that forms linear potential Mississippian-age traps and a previously unidentified continuation of the Rome trough and Sequatchie Valley fault beneath the western section of the Wartburg basin in Tennessee. The Flynn Creek impact structure was also investigated because it has a good hydrocarbon potential and may have economical reserves. The impact occurred in a carbonate-dominated target during the Late Devonian. Four persistent, concentric faults indicate the Flynn Creek impact structure is not asymmetric and has a diameter of 4.7 km (2.9 mi), which was calculated from the outermost partially developed fault system, or 4 km (2.5 mi) using the third fault system, which is fully developed. Both estimates are larger than the previously estimated 3.8 km.

Evenick, Jonathan Charles

385

In vitro evaluation of germination and growth of five plant species on medium supplemented with hydrocarbons associated with contaminated soils.  

PubMed

The effect of a hydrocarbon mixture (HCM) of three polycyclic aromatic hydrocarbons (PAH) and Maya crude oil on germination, growth and survival of four grasses (Bouteloua curtipendula, Cenchrus ciliaris, Echinochloa crusgalli and Rhynchelytrum repens) was studied and compared to a control (Festuca arundinacea) under in vitro conditions. The species were cultured on MS medium with different HCM initial concentrations. Germination was not affected for any assayed concentration; however, the length of the stems and roots decreased when HCM increased and the survival of the four species also diminished. Except for F. arundinacea, a direct link between hydrocarbon concentration and plant survival was observed. In vitro studies are clean and easy to handle techniques allowing isolation of the plant activity from that derived from associations with microorganisms in non-sterile cultures. To our knowledge, this is the first work towards phytoremediation assisted by in vitro plant cultivation. PMID:18222086

Reynoso-Cuevas, L; Gallegos-Martínez, M E; Cruz-Sosa, F; Gutiérrez-Rojas, M

2008-09-01

386

Subsurface Samples: Collection and Processing  

SciTech Connect

Microbiological data, interpretation, and conclusions from subsurface samples ultimately depend on the quality and representative character of the samples. Subsurface samples for environmental microbiology ideally contain only the microbial community and geochemical properties that are representative of the subsurface environment from which the sample was taken. To that end, sample contamination by exogenous microorganisms or chemical constituents must be eliminated or minimized, and sample analyses need to begin before changes in the microbial community or geochemical characteristics occur. This article presents sampling methods and sample processing techniques for collecting representative samples from a range of subsurface environments. Factors that should be considered when developing a subsurface sampling program are discussed, including potential benefits, costs, and limitations enabling researchers to evaluate the techniques that are presented and match them to their project requirements. Methods and protocols to address coring, sampling, processing and quality assessment issues are presented.

Long, Philip E.; Griffin, W. Timothy; Phelps, Tommy J.

2002-12-01

387

Estimation of uncertainty in the sampling and analysis of polychlorinated biphenyls and polycyclic aromatic hydrocarbons from contaminated soil in Brighton, UK.  

PubMed

The heterogeneity of environmental samples is increasingly recognised, yet rarely examined in organic contamination investigations. In this study soil samples from an ex-landfill site in Brighton, UK were analysed for polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) contamination by using a balanced sampling protocol. The analytical technique of gas chromatography-mass spectrometry was found to be fit for purpose by the use of duplicate samples and the statistical analysis of variances, as well as of certified reference materials. The sampling uncertainty was found to significantly overweigh the analytical uncertainty, by a factor of 3 and 6 for PCBs and PAHs, respectively. The soil samples showed a general trend of PCB concentration that was under the recommended target level of 20 ng/g dry weight. It is possible that one site alongside the main road may exceed the 20 ng/g target level, after taking into consideration the overall measurement uncertainty (70.8%). The PAH contamination was more severe, with seven sites potentially exceeding the effect-range medium concentrations. The soil samples with relatively high PCB and PAH concentrations were all taken from the grass verge, which also had the highest soil organic carbon content. The measurement uncertainty which was largely due to sampling can be reduced by sampling at a high resolution spacing of 17 m, which is recommended in future field investigations of soil organic contamination. PMID:25128886

Zhou, John L; Siddiqui, Ertan; Ngo, Huu Hao; Guo, Wenshan

2014-11-01

388

Relating groundwater and sediment chemistry to microbial characterization at a BTEX-contaminated site  

SciTech Connect

The National Center for Manufacturing Science is investigating bioremediation of petroleum hydrocarbon at a site in Belleville, Michigan. As part of this study we examined the microbial communities to help elucidate biodegradative processes currently active at the site. We observed high densities of aerobic hydrocarbon degraders and denitrifiers in the less-contaminated sediments. Low densities of iron and sulfate reducers were measured in the same sediments. In contrast, the highly-contaminated sediments showed low densities of aerobic hydrocarbon degraders and denitrifiers and high densities of iron and sulfate reducers. Methanogens were also found in these highly-contaminated sediments. These contaminated sediments also showed a higher biomass, by phospholipid fatty acids, and greater ratios of phospholipid fatty acids which indicate stress within the microbial community. Aquifer chemistry analyses indicated that the more-contaminated area was more reduced and had lower sulfate than the less-contaminated area. These conditions suggest that the subsurface environment at the highly-contaminated area had progressed into sulfate reduction and methanogensis. The less-contaminated area, although less reduced, also appeared to be progressing into primarily iron- and sulfate-reducing microbial communities. The proposed treatment to stimulate bioremediation includes addition of oxygen and nitrate. Groundwater chemistry and microbial analyses revealed significant differences resulted from the injection of dissolved oxygen and nitrate in the subsurface. These differences included increases in pH and Eh and large decreases in BTEX, dissolved iron, and sulfate concentrations at the injection well.

Pfiffner, S.M.; Palumbo, A.V.; McCarthy, J.F. [Oak Ridge National Lab., TN (United States); Gibson, T. [General Motors Research and Development Center, Warren, MI (United States)] [and others

1996-07-01

389

Comparison of Plant Families in a Greenhouse Phytoremediation Study on an Aged Polycyclic Aromatic Hydrocarbon–Contaminated Soil  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, recalcitrant, and potentially carcinogenic pollutants. Plants and their associated rhizosphere microbes can promote PAH dissipation, off ering an economic and ecologically attractive remediation technique. Th is study focused on the eff ects of diff erent types of vegetation on PAH removal and on the interaction between the plants and their associated microorganisms. Aged PAH-polluted

Paul E. Olson; Ana Castro; Mark Joern; Nancy M. DuTeau; Elizabeth A. H. Pilon-Smits; Kenneth F. Reardon

2007-01-01

390

Avoidance response of the estuarine amphipod Eohaustorius estuarius to polycyclic aromatic hydrocarbon-contaminated, field-collected sediments  

SciTech Connect

Amphipods (Eohaustorius estuarius) were placed in two-chamber containers with different combinations of three contaminated sediments and a control sediment, and their distribution was determined after 2 or 3 d. Amphipods avoided the sediment with the highest PAH contamination and one of two sediments with moderate PAH concentrations. In the moderately contaminated sediment avoided by amphipods, the (avoidance) response was more sensitive than mortality as a biological indicator of unacceptable sediment contamination. The avoidance response in this case likely represents an early indication of potential mortality from sediment exposure. Population levels of amphipods in moderately to heavily PAH-contaminated sediments may be influenced by a combination of avoidance behavior and toxicity/lethality.

Kravitz, M.J. (Environmental Protection Agency, Washington, DC (United States). Office of Water); Lamberson, J.O.; Ferraro, S.P.; Swartz, R.C.; Boese, B.L.; Specht, D.T. (Environmental Protection Agency, Newport, OR (United States))

1999-06-01

391

Diffusion of gasoline-range hydrocarbon vapors in porous media  

SciTech Connect

In this study a variety of physical and chemical factors affecting gasoline-range hydrocarbon vapor diffusion were investigated using laboratory-scale soil column reactors. Experimentation was designed to simulate actual stabilized boundary conditions following a spill or subsurface discharge of immiscible contaminants (e.g., gasoline hydrocarbons) to the unsaturated zone. Experimental results are compared with values predicted using existing theories and models which describes gaseous diffusive flux through soil columns. Soil column reactors were constructed of 4'' I.D. aluminum pipe, and consisted of a liquid hydrocarbon reservoir, soil support screen, 15'' soil column with sample ports, an enclosed headspace and a metered headspace sweep gas device. The design of the column allowed the measurement of hydrocarbon concentration gradients and hydrocarbon flux rates. Diffusion of benzene vapor was observed in a series of experiments designed to isolate and evaluate the physical e