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1

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

PubMed Central

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

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

2009-01-01

2

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

SciTech Connect

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

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

1988-01-01

3

Monitoring microbial community in a subsurface soil contaminated with hydrocarbons by quinone profile.  

PubMed

A natural attenuation experiment was carried out using a lysimeter for 308 days after contaminating the subsoil with hydrocarbons (HCs) and the changes in the structures of microbial community in the hydrocarbon (HC) contaminated subsoil were monitored by quinone profile analysis. The residues of HCs remained for 217 days in the subsoil after the contamination. The amount of total quinones (TQ), an indicator of microbial biomass, significantly increased in the HC contaminated subsoil for 217 days, comparing with that of the background subsoil or the subsoil before the addition of HCs. The major quinone species and the quinone composition, indicators of community structure, were significantly different between the HC contaminated soil and the background soil for 217 days. The major increased quinine species in the HC contaminated soil were menaquinone-8(H4), menaquinone-9(H2) and ubiquinone-9, indicating the propagation of Gram-positive bacteria with high guanine and cytosine content and gamma-subclass of Proteobacteria and fungi. There was no significant difference in the diversity of the quinone species (DQ), an indicator of taxonomic diversity of microbial community, except for the decrease in DQ in the shallow subsoil after 35 days when a high concentration of HCs was detected. After 308 days when the HCs in the subsoil disappeared, TQ returned to the level of the background soil, and no significant difference in quinone composition were observed between the HC contaminated soil and the background soil. The results suggested that respiratory quinones are effective biomarkers for characterizing the temporal changes of microbial community in the HC contaminated subsoil. PMID:15763082

Song, Dejun; Katayama, Arata

2005-04-01

4

Subsurface contaminants focus area.  

National Technical Information Service (NTIS)

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, includi...

1996-01-01

5

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

6

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

7

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

Microsoft Academic Search

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

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

2005-01-01

8

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

9

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...

10

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...

11

Understanding the fate of petroleum hydrocarbons in the subsurface environment  

SciTech Connect

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

Chen, C.T.

1992-01-01

12

Understanding the fate of petroleum hydrocarbons in the subsurface environment  

Microsoft Academic Search

To achieve effective remediation of subsurface petroleum hydrocarbon contamination, definite scientific and technical knowledge of their fate after they are spilled onto the ground surface or leaked from underground storage tanks is essential. The paper provides extensive details of the parameters that affect the fate of petroleum products in the underground environment. These include: the character of the subsurface environment;

Chien T. Chen

1992-01-01

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

Modeling subsurface contamination at Fernald  

SciTech Connect

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

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

1994-09-13

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

A bioenhancement process for rapid remediation of multiphase subsurface contamination  

SciTech Connect

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

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

1994-08-01

17

Subsurface Contaminants Focus Area annual report 1997  

SciTech Connect

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

NONE

1997-12-31

18

Subsurface Assessment Handbook for Contaminated Sites.  

National Technical Information Service (NTIS)

The purpose of the handbook is to improve subsurface investigations at contaminated sites. Site investigations draw on many disciplines (e.g., geology, chemistry, mathematics, and biology) and therefore challenge both investigators and users of the result...

J. F. Barker R. V. Nicholson D. J. A. Smyth J. P. Greenhouse P. J. Gudjurgis D. L. Rudolph J. W. Molson E. O. Frind E. A. Sudicky M. Graham

1994-01-01

19

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...

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

Phytoremediation of hydrocarbon contaminated soils  

SciTech Connect

This book presents innovative technology for environmental clean up using in situ treatment. It describes the results of a field study focusing on hydrocarbon contamination, especially polynuclear aromatic hydrocarbons, in surface and near surface soils. The field demonstration used soils contaminated with aged diesel fuels. The random block design enabled the investigators to test the statistical difference in the effects of different vegetated and unvegetated treatments. They tested the degradation of diesel and polynuclear aromatic hydrocarbon components in plots containing three different vegetation treatments, two grasses, and a legume, and a non-vegetated control. Part one of the monograph gives a complete and thorough account of the results of the field study. Part two covers the design and potential costs of a full-scale implementation of the demonstration system as well as the performance and potential application of the new technology.

Banks, M.K.; Govindaraju, R.S.; Schwab, A.P. [Purdue Univ., Lafayette, IN (United States); Kulakow, P. [Kansas State Univ., Manhattan, KS (United States); Finn, J. [Remediation Technologies, Inc. (United States)

1999-11-01

23

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...

24

Characterization of the methanotrophic bacterial community present in a trichloroethylene-contaminated subsurface groundwater site  

SciTech Connect

Contamination of subsurface environments with chlorinated hydrocarbons is a potentially serious threat to drinking water sources. Subsurface microbial communities degrade a wide variety of chlorinated hydrocarbons in the laboratory. This paper examines the ground water methanotrophic community, finding that it is dominated by sMMO-producting group II methanotrophs, suggested by the presence of sMMO genes in the aquifer sediments, and well adapted to oligotrophic conditions. sMMO is expressed in the sediments, but it is not clear that this is sufficient for in situ bioremediation. 46 refs., 2 figs., 2 tabs.

Bowman, J.P.; Jimenez, L.; Rosario, I.; Sayler, G.S. (Univ. of Tennessee, Knoxville (United States)); Hazen, T.C. (Westinghouse Savannah River Laboratory, Aiken, SC (United States))

1993-08-01

25

Identifying future directions for subsurface hydrocarbon migration research  

NASA Astrophysics Data System (ADS)

Subsurface hydrocarbon migration is important for understanding the input and impacts of natural hydrocarbon seepage on the environment. Great uncertainties remain in most aspects of hydrocarbon migration, including some basic mechanisms of this four-phase flow of tar, oil, water, and gas through the complex fracture-network geometry particularly since the phases span a wide range of properties. Academic, government, and industry representatives recently attended a workshop to identify the areas of greatest need for future research in shallow hydrocarbon migration.Novel approaches such as studying temporal and spatial seepage variations and analogous geofluid systems (e.g., geysers and trickle beds) allow deductions of subsurface processes and structures that remain largely unclear. Unique complexities exist in hydrocarbon migration due to its multiphase flow and complex geometry, including in-situ biological weathering. Furthermore, many aspects of the role of hydrocarbons (positive and negative) in the environment are poorly understood, including how they enter the food chain (respiration, consumption, etc.) and “percolate” to higher trophic levels. But understanding these ecological impacts requires knowledge of the emissions' temporal and spatial variability and trajectories.

Leifer, I.; Clark, J. F.; Luyendyk, B.; Valentine, D.

26

MAPPING OF SUBSURFACE CONTAMINANT PROFILES BY NEURAL NETWORKS  

Microsoft Academic Search

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

CLAIRE JORDAHL Project Engineer

1999-01-01

27

Bioremediation of Petroleum Hydrocarbon Contaminated Sites  

SciTech Connect

Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of environmental parameters on bioremediation is important in designing a bioremediation system to reduce petroleum hydrocarbon concentrations in impacted soils.

Paul Fallgren

2009-03-30

28

Field-Scale Assessment of Phytotreatment of Soil Contaminated with Weathered Hydrocarbons and Heavy Metals (9 pp)  

Microsoft Academic Search

Background, Aim and Scope  \\u000a Phytoremediation is a remediation method which uses plants to remove, contain or detoxify environmental contaminants. Phytoremediation\\u000a has successfully been applied for the removal of fresh hydrocarbon contamination, but removal of aged hydrocarbons has proven\\u000a more difficult. Biodegradation of hydrocarbons in the subsurface can be enhanced by the presence of plant roots, i.e. the\\u000a rhizosphere effect. Phytostabilization

Kati Vaajasaari; Anneli Joutti

2006-01-01

29

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

SciTech Connect

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

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

1996-10-01

30

ANAEROBIC BIOTRANSFORMATION OF CONTAMINANTS IN THE SUBSURFACE  

EPA Science Inventory

Anaerobic conditions predominate in contaminated aquifers and are not uncommon in noncontaminated areas. Comparatively little is known about degradative processes and nutrient cycling under anaerobic conditions. However, it is apparent these processes are fundamentally differen...

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

New barrier fluids for subsurface containment of contaminants  

Microsoft Academic Search

In some situations, containment of contaminants in the subsurface may be preferable to removal or treatment in situ. In these cases, it maybe possible to form barriers by injecting fluids (grouts) that set in place and reduce the formation permeability. This paper reports laboratory work to develop two types of fluids for this application: colloidal silica (CS) and polysiloxane (PSX).

G. J. Moridis; P. Persoff; H. Y. Holman; S. J. Muller; K. Pruess; C. J. Radke

1993-01-01

33

The Stimulation of Hydrocarbon Reservoirs with Subsurface Nuclear Explosions  

SciTech Connect

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

LORENZ,JOHN C.

2000-12-08

34

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

SciTech Connect

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

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

1993-02-01

35

Abiotic Organic Chemistry of the Terrestrial Deep Subsurface: Isotopic Constraints on Hydrocarbon Formation  

Microsoft Academic Search

In serpentinized terrains in both marine and terrestrial subsurface, recent attention has focused on H2 and hydrocarbon gases - on their potential production by abiogenic processes of water-rock interaction; the possibility of their use by deep microbial communities as substrates for life; and on the relevance of such subsurface analogs for the origin of life on earth or elsewhere in

B. Sherwood Lollar; T. M. McCollom; J. S. Seewald; G. Lacrampe-Couloume

2008-01-01

36

Hydrocarbon Contamination in Groundwaters: Removal by Alcohol Flooding.  

National Technical Information Service (NTIS)

Present pump-and-treat remediation strategies employed to remove hydrocarbon contaminants that exist in groundwater as nonaqueous phase liquids (NAPLs) can displace only a fraction of the contaminant due to the trapping effects of capillary forces. These ...

K. J. Farley G. R. Boyd S. Patwardhan

1992-01-01

37

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...

38

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

39

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

40

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

NASA Astrophysics Data System (ADS)

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

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

2003-04-01

41

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

42

Development of a Data Evaluation/Decision Support System for Remediation of Subsurface Contamination.  

National Technical Information Service (NTIS)

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 w...

F. Eisenberg D. B. McLaughlin

2001-01-01

43

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...

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

Microbial degradation of petroleum hydrocarbon contaminants: an overview.  

PubMed

One of the major environmental problems today is hydrocarbon contamination resulting from the activities related to the petrochemical industry. Accidental releases of petroleum products are of particular concern in the environment. Hydrocarbon components have been known to belong to the family of carcinogens and neurotoxic organic pollutants. Currently accepted disposal methods of incineration or burial insecure landfills can become prohibitively expensive when amounts of contaminants are large. Mechanical and chemical methods generally used to remove hydrocarbons from contaminated sites have limited effectiveness and can be expensive. Bioremediation is the promising technology for the treatment of these contaminated sites since it is cost-effective and will lead to complete mineralization. Bioremediation functions basically on biodegradation, which may refer to complete mineralization of organic contaminants into carbon dioxide, water, inorganic compounds, and cell protein or transformation of complex organic contaminants to other simpler organic compounds by biological agents like microorganisms. Many indigenous microorganisms in water and soil are capable of degrading hydrocarbon contaminants. This paper presents an updated overview of petroleum hydrocarbon degradation by microorganisms under different ecosystems. PMID:21350672

Das, Nilanjana; Chandran, Preethy

2011-01-01

46

Hydrocarbon-degradation potential in reference soils and soils contaminated with jet fuel  

SciTech Connect

A series of test wells were drilled adjacent to a fuel farm and a JP-5 jet fuel pump station located at a naval air station in Maryland. At least 5 hectares of subsurface soil (to an average depth of 4m) above a local aquifer were found to contain high concentrations of petroleum compounds, including such volatile aromatics as benzene, toluene, ethylbenzene, and xylenes. Horizontal transport has resulted in slow seepage from banks into streams of the affected area. The source of the petroleum is due to various spills over the past 10 years and possible continuous leakage from the tanks. There is a large body of literature describing the microbial metabolism of polycyclic aromatic hydrocarbons in aerobic solid-water system. Petroleum degradation in surface and subsurface soils is affected by such factors as moisture content, pH, soil type, soil organics, temperature, and oxygen concentrations. The authors determined the degradation rates of 14C-labeled hydrocarbons added to soils collected from a contaminated surface site (Site D), contaminated subsurface sites (Wells A and B), and a clean reference site (Well C).

Lee, R.F.; Hoeppel, R.

1990-01-01

47

Removal of trichloroethylene contamination from the subsurface: A comparative evaluation of different remediation strategies by means of numerical simulation  

SciTech Connect

Volatile organic compounds such as petroleum hydrocarbons and halogenated hydrocarbon solvents are common contaminants of the subsurface environment. Although immiscible with water, many of these organics have large enough aqueous phase solubilities to significantly degrade the quality of groundwater with which they come in contact. In addition, many of these substances exhibit high vapor pressures, causing them to partition strongly into the gas phase in their surroundings. Because of these properties, a volatile organic compound (VOC), once introduced into the subsurface may be transported as a solute, a vapor, or as a constituent in a non- aqueous phase liquid (NAPL). This implies that at some sits, an adequate description of the migration of these contaminants in the subsurface would necessarily involve three phases, -- gas, aqueous and NAPL. For example, to design an effective aquifer remediation scheme for a site where NAPL is present, it would be wrong to focus solely on the aqueous phase while ignoring either the gas phase or the NAPL phase. In the present work, we use a simulator developed by Falta et al. (1990a), known as STMVOC,'' which models true three-phase flow in which NAPL, gas and aqueous phases can move in response to pressure, capillary and gravitational forces. STMVOC is capable of handling three-dimensional, three-phase fluid flow with strong heat transport and the associated phased change effects. 16 refs., 5 figs., 4 tabs.

Adenekan, A.E.; Pruess, K.; Falta, R.W.

1990-12-01

48

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

49

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

50

Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout  

USGS Publications Warehouse

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. Copyright ?? 2011 by the American Geophysical Union.

Socolofsky, S. A.; Adams, E. E.; Sherwood, C. R.

2011-01-01

51

Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout  

USGS Publications Warehouse

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.

2011-01-01

52

GEOCHEMISTRY OF SUBSURFACE REACTIVE BARRIERS FOR REMEDIATION OF CONTAMINATED GROUND WATER  

EPA Science Inventory

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

53

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

54

PREDICTING SUBSURFACE CONTAMINANT TRANSPORT AND TRANSFORMATION: CONSIDERATIONS FOR MODEL SELECTION AND FIELD VALIDATION  

EPA Science Inventory

Predicting subsurface contaminant transport and transformation requires mathematical models based on a variety of physical, chemical, and biological processes. The mathematical model is an attempt to quantitatively describe observed processes in order to permit systematic forecas...

55

Hydrocarbon contamination in Cartagena Bay, Colombia  

Microsoft Academic Search

This study deals with the levels of aromatic and aliphatic hydrocarbon quantification in sediments and organisms in Cartagena Bay (Colombia), 1996–1997. Sediments (14 stations) and bivalves (2 stations) were monitored at different times of the year. Areas with high values were in the north with concentrations above 100 ?g\\/g with a maximum of 1415 ?g\\/g. Areas with low values were

C. H Parga-Lozano; A. J Marrugo-González; R Fernández-Maestre

2002-01-01

56

Animal Waste-Enhanced Degradation of Hydrocarbon-Contaminated Soil  

Microsoft Academic Search

Land previously used for petroleum production is being converted to commercial, industrial, or residential uses and requires remediation to remove petroleum hydrocarbons (HC). Concurrently, large quantities of animal wastes are produced annually, creating waste-handling and disposal problems. A laboratory study was conducted to determine whether amending contaminated soil with animal manure and inorganic fertilizer affected the degradation rate and amount

Daniel E. Wellman; April L. Ulery; Matthew P. Barcellona; Sonja Duerr-Auster

2001-01-01

57

Pressurised liquid extraction of polycyclic aromatic hydrocarbons from contaminated soils  

Microsoft Academic Search

The reliability and efficiency of the pressurised liquid extraction technique (PLE) for extracting polycyclic aromatic hydrocarbons (PAHs) from contaminated soil has been investigated. Experimental design was used to study the influence of seven extraction variables (sample load, solvents used, solvent ratios, pressure, temperature, extraction time, and rinse volume). The results show that large sample loads in combination with small solvent

Staffan Lundstedt; Bert van Bavel; Peter Haglund; Mats Tysklind; Lars Öberg

2000-01-01

58

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

59

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

Microsoft Academic Search

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

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

2002-01-01

60

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

61

Method for removing hydrocarbon contaminants from solid materials  

DOEpatents

A system 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).

Bala, Gregory A. (Idaho Falls, ID); Thomas, Charles P. (Idaho Falls, ID)

1995-01-01

62

Apparatus for removing hydrocarbon contaminants from solid materials  

DOEpatents

A system 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).

Bala, Gregory A. (Idaho Falls, ID); Thomas, Charles P. (Idaho Falls, ID)

1996-01-01

63

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

64

Abiotic Organic Chemistry of the Terrestrial Deep Subsurface: Isotopic Constraints on Hydrocarbon Formation  

NASA Astrophysics Data System (ADS)

In serpentinized terrains in both marine and terrestrial subsurface, recent attention has focused on H2 and hydrocarbon gases - on their potential production by abiogenic processes of water-rock interaction; the possibility of their use by deep microbial communities as substrates for life; and on the relevance of such subsurface analogs for the origin of life on earth or elsewhere in the solar system. In deep subsurface Precambrian Shield rocks in South Africa, Canada and Finland, H2, methane and higher hydrocarbon gases have been identified at depths of 1-4 km. While some sites are dominated by gases produced by microbial methanogenesis, the deepest, most ancient fracture waters with residence times on the order of tens of millions of years contain hydrocarbon gases with a pattern of carbon isotope depletion in 13C and hydrogen isotope enrichment in 2H between methane and ethane consistent with abiogenic polymerization1. More recently, the carbon and hydrogen isotope variation between the higher hydrocarbon homologues have also been demonstrated to fit a simple mass balance model consistent with abiogenic polymerization reactions2. In this study, a series of experiments were performed by heating aqueous solutions at 250°C and 170Mpa under reducing conditions using powdered native Fe as a source of H2 and catalyst, and CO as a carbon source in a flexible cell hydrothermal apparatus. Experiments resulted in rapid generation of methane and higher hydrocarbon products typical of Fischer- Tropsch abiotic organic synthesis. These gases were analyzed for carbon and hydrogen isotopes to verify the polymerization model. Unlike the field samples, the experiments showed a carbon isotope enrichment between methane and ethane - suggesting that the extent of fractionation in the first, most highly fractionating step may vary as a function of different reaction mechanisms or parameters such as catalysts or conversion ratios. For the higher hydrocarbons however, carbon isotope values were completely consistent with the abiogenic polymerization model, as for the field samples. It appears that the rapid rate of chain polymerization is such that any net isotopic fractionation associated with subsequent carbon addition steps is negligible and suggests that carbon isotope values for the higher alkane gases may be predicted independent of the fractionation associated with the first step.1.Sherwood Lollar et al. (2002) Nature 416:522-524.2.Sherwood Lollar et al. (2008) GCA doi:10.1016/j.gca.2008.07.004

Sherwood Lollar, B.; McCollom, T. M.; Seewald, J. S.; Lacrampe-Couloume, G.

2008-12-01

65

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

Microsoft Academic Search

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

J. D. Albino; I. M. Nambi

2009-01-01

66

Subsurface hydrologic monitoring to evaluate contaminant migration: requirements and solutions  

SciTech Connect

Providing adequate subsurface monitoring for solid-waste treatment and disposal facilities involves a variety of complexities, many of which are due to the diversity of the waste forms and of the geologic and hydrologic settings encountered. An adequate and cost-effective evaluation of ground-water quality under such diverse conditions requires the coordination of a variety of technical disciplines and analytic methods. The purpose of this discussion is to: (1) consider the relationship of monitoring and the more detailed subsurface environmental performance assessments; (2) show how subsurface monitoring is best planned and organized within the framework of the overall environmental performance assessment objectives; and (3) explain the requirements and background needed for environmental evaluations of solid-waste treatment facilities and disposal sites.

Nelson, R.W.

1981-09-01

67

Innovative Processes for Reclamation of Contaminated Subsurface Environments.  

National Technical Information Service (NTIS)

Research to better assess the capabilities and limitations of fixed-film bioreactors for removing selected organic contaminants from ground water or from contaminated vapor streams produced by air stripping of polluted ground water and by soil venting ope...

L. W. Canter L. E. Streebin M. Carlota Arquiaga F. E. Carranza D. E. Miller

1989-01-01

68

Are Microbial Nanowires Responsible for Geoelectrical Changes at Hydrocarbon Contaminated Sites?  

NASA Astrophysics Data System (ADS)

Significant advances in near-surface geophysics and biogeophysics in particular, have clearly established a link between geoelectrical response and the growth and enzymatic activities of microbes in geologic media. Recent studies from hydrocarbon contaminated sites suggest that the activities of distinct microbial populations, specifically syntrophic, sulfate reducing, and dissimilatory iron reducing microbial populations are a contributing factor to elevated sediment conductivity. However, a fundamental mechanistic understanding of the processes and sources resulting in the measured electrical response remains uncertain. The recent discovery of bacterial nanowires and their electron transport capabilities suggest that if bacterial nanowires permeate the subsurface, they may in part be responsible for the anomalous conductivity response. In this study we investigated the microbial population structure, the presence of nanowires, and microbial-induced alterations of a hydrocarbon contaminated environment and relate them to the sediments' geoelectrical response. Our results show that microbial communities varied substantially along the vertical gradient and at depths where hydrocarbons saturated the sediments, ribosomal intergenic spacer analysis (RISA) revealed signatures of microbial communities adapted to hydrocarbon impact. In contrast, RISA profiles from a background location showed little community variations with depth. While all sites showed evidence of microbial activity, a scanning electron microscope (SEM) study of sediment from the contaminated location showed pervasive development of "nanowire-like structures" with morphologies consistent with nanowires from laboratory experiments. SEM analysis suggests extensive alteration of the sediments by microbial Activity. We conclude that, excess organic carbon (electron donor) but limited electron acceptors in these environments cause microorganisms to produce nanowires to shuttle the electrons as they seek for distant electron acceptors. Hence, electron flow via bacterial nanowires may contribute to the geoelectrical response.

Hager, C.; Atekwana, E. A.; Gorby, Y. A.; Duris, J. W.; Allen, J. P.; Atekwana, E. A.; Ownby, C.; Rossbach, S.

2007-05-01

69

Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil.  

PubMed

A diesel fuel spill at a concentration of 1 L m(-2) soil was simulated on a 12 m(2) plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. PMID:17555854

Serrano, Antonio; Gallego, Mercedes; González, Jose Luis; Tejada, Manuel

2008-02-01

70

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

71

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

72

The role of biominerals in enhancing the geophysical response at hydrocarbon contaminated sites  

NASA Astrophysics Data System (ADS)

There are several source mechanisms by which microbial activity in the subsurface can change geophysical signatures. To date the source mechanisms generating the geophysical signatures in microbially active environments remain poorly understood. In this study, we investigated the link between the biogeochemical processes resulting in biotransformation of metallic iron mineral phases and the associated biogeophysical signatures. Hydrocarbon contaminated environments provide excellent laboratories for investigating iron mineral biotransformation. In particular, we investigated the magnetic susceptibility (MS) and the complex conductivity (CC) signatures of a hydrocarbon contaminated site near Bemidji, Minnesota. For the MS study, we investigated the changes in the MS response for cores retrieved from the site as well as down boreholes. The contaminated location revealed two enriched MS zones. The first MS lies within the hydrocarbon smear zone, which is limited to the zone of water table fluctuation with high concentrations of dissolved Fe(II) and organic carbon content. Magnetite and siderite were the dominant minerals formed during this process. However, magnetite was responsible for the bulk of MS changes. The second zone of MS enhancement lies within the vadose zone which is characterized by methane depletion suggesting that aerobic or anaerobic oxidation of methane is coupled to iron-reduction resulting in magnetite precipitation. For the CC work, we conducted laboratory CC measurements along four cores in addition to field CC survey. We found that the real (sigma?) and imaginary (sigma?) conductivity are higher for samples from within the oil plume especially within the smear zone compared to background uncontaminated samples. Using magnetite as an example of the biometallic minerals in the smear zone at the site, a clear increase in the sigma? response with increasing magnetite content was observed suggesting that the presence of bio-metallic mineral phases as well as electroactive Fe(II) within the smear zone impacts the imaginary conductivity. Our results suggest that the biogeochemical processes leading to the precipitation of metallic iron mineral phases impacts the geophysical signatures at hydrocarbon contaminated sites undergoing active biodegradation. These bio-metallic minerals (e.g., magnetite) provide us with another source mechanism which has not been considered in previous studies. Therefore, the recognition of the zone of enriched bio-metallic iron mineral phases within the water table fluctuating zone calls for a reevaluation of biogeophysical signatures observed at hydrocarbon contaminated sites commonly attributed to an enhancement of pore water conductivity related to the production of metabolic byproducts.

Mewafy, Farag Mohamed

73

Relating Hybrid Poplar Fine Root Production, Soil Nutrients, and Hydrocarbon Contamination  

Microsoft Academic Search

Quantifying the effects of hydrocarbon contamination on hybrid poplar fine root dynamics provides information about how well these trees tolerate the adverse conditions imposed by the presence of petroleum in the soil. The objective of this research was to investigate the relationship between the varying concentrations of total petroleum hydrocarbons (TPH) and nutrients across a hydrocarbon-contaminated site, and quantify the

J. J. Gunderson; J. D. Knight; K. C. J. Van Rees

2008-01-01

74

Estimation of hydrocarbon biodegradation rates in gasoline-contaminated sediment from measured respiration rates  

USGS Publications Warehouse

An open microcosm method for quantifying microbial respiration and estimating biodegradation rates of hydrocarbons in gasoline-contaminated sediment samples has been developed and validated. Stainless-steel bioreactors are filled with soil or sediment samples, and the vapor-phase composition (concentrations of oxygen (O2), nitrogen (N2), carbon dioxide (CO2), and selected hydrocarbons) is monitored over time. Replacement gas is added as the vapor sample is taken, and selection of the replacement gas composition facilitates real-time decision-making regarding environmental conditions within the bioreactor. This capability allows for maintenance of field conditions over time, which is not possible in closed microcosms. Reaction rates of CO2 and O2 are calculated from the vapor-phase composition time series. Rates of hydrocarbon biodegradation are either measured directly from the hydrocarbon mass balance, or estimated from CO2 and O2 reaction rates and assumed reaction stoichiometries. Open microcosm experiments using sediments spiked with toluene and p-xylene were conducted to validate the stoichiometric assumptions. Respiration rates calculated from O2 consumption and from CO2 production provide estimates of toluene and p- xylene degradation rates within about ??50% of measured values when complete mineralization stoichiometry is assumed. Measured values ranged from 851.1 to 965.1 g m-3 year-1 for toluene, and 407.2-942.3 g m-3 year-1 for p- xylene. Contaminated sediment samples from a gasoline-spill site were used in a second set of microcosm experiments. Here, reaction rates of O2 and CO2 were measured and used to estimate hydrocarbon respiration rates. Total hydrocarbon reaction rates ranged from 49.0 g m-3 year-1 in uncontaminated (background) to 1040.4 g m-3 year-1 for highly contaminated sediment, based on CO2 production data. These rate estimates were similar to those obtained independently from in situ CO2 vertical gradient and flux determinations at the field site. In these experiments, aerobic conditions were maintained in the microcosms by using air as the replacement gas, thus preserving the ambient aerobic environment of the subsurface near the capillary zone. This would not be possible with closed microcosms.

Baker, R. J.; Baehr, A. L.; Lahvis, M. A.

2000-01-01

75

Estimation of hydrocarbon biodegradation rates in gasoline-contaminated sediment from measured respiration rates  

NASA Astrophysics Data System (ADS)

An open microcosm method for quantifying microbial respiration and estimating biodegradation rates of hydrocarbons in gasoline-contaminated sediment samples has been developed and validated. Stainless-steel bioreactors are filled with soil or sediment samples, and the vapor-phase composition (concentrations of oxygen (O 2), nitrogen (N 2), carbon dioxide (CO 2), and selected hydrocarbons) is monitored over time. Replacement gas is added as the vapor sample is taken, and selection of the replacement gas composition facilitates real-time decision-making regarding environmental conditions within the bioreactor. This capability allows for maintenance of field conditions over time, which is not possible in closed microcosms. Reaction rates of CO 2 and O 2 are calculated from the vapor-phase composition time series. Rates of hydrocarbon biodegradation are either measured directly from the hydrocarbon mass balance, or estimated from CO 2 and O 2 reaction rates and assumed reaction stoichiometries. Open microcosm experiments using sediments spiked with toluene and p-xylene were conducted to validate the stoichiometric assumptions. Respiration rates calculated from O 2 consumption and from CO 2 production provide estimates of toluene and p-xylene degradation rates within about ±50% of measured values when complete mineralization stoichiometry is assumed. Measured values ranged from 851.1 to 965.1 g m -3 year -1 for toluene, and 407.2-942.3 g m -3 year -1 for p-xylene. Contaminated sediment samples from a gasoline-spill site were used in a second set of microcosm experiments. Here, reaction rates of O 2 and CO 2 were measured and used to estimate hydrocarbon respiration rates. Total hydrocarbon reaction rates ranged from 49.0 g m -3 year -1 in uncontaminated (background) to 1040.4 g m -3 year -1 for highly contaminated sediment, based on CO 2 production data. These rate estimates were similar to those obtained independently from in situ CO 2 vertical gradient and flux determinations at the field site. In these experiments, aerobic conditions were maintained in the microcosms by using air as the replacement gas, thus preserving the ambient aerobic environment of the subsurface near the capillary zone. This would not be possible with closed microcosms.

Baker, Ronald J.; Baehr, Arthur L.; Lahvis, Matthew A.

2000-01-01

76

USE OF APATITE FOR CHEMICAL STABILIZATION OF SUBSURFACE CONTAMINANTS  

SciTech Connect

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. Environmental Protection Agency (EPA) Superfund Sites include lead (Pb), arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), zinc (Zn), selenium (Se), antimony (Sb), copper (Cu) and nickel (Ni). Thus, the regulatory ''drivers'' for toxic metals in contaminated soils/groundwaters are very comparable for Federal and civilian industrial sites, and most sites have more than one metal above regulatory action limits. Thus improving the performance of remedial technologies for metal-contaminated groundwater will have ''dual use'' (Federal and civilian) benefit.

Dr. William D. Bostick

2003-05-01

77

Reactive Membrane Barriers for Containment of SubSurface Contamination (September 15, 2002-December 15, 2006, Final Report).  

National Technical Information Service (NTIS)

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 incorpora...

W. A. Arnold E. L. Cussler

2006-01-01

78

CO2-efflux measurements for evaluating source zone natural attenuation rates in a petroleum hydrocarbon contaminated aquifer.  

PubMed

In order to gain regulatory approval for source zone natural attenuation (SZNA) at hydrocarbon-contaminated sites, knowledge regarding the extent of the contamination, its tendency to spread, and its longevity is required. However, reliable quantification of biodegradation rates, an important component of SZNA, remains a challenge. If the rate of CO(2) gas generation associated with contaminant degradation can be determined, it may be used as a proxy for the overall rate of subsurface biodegradation. Here, the CO(2)-efflux at the ground surface is measured using a dynamic closed chamber (DCC) method to evaluate whether this technique can be used to assess the areal extent of the contaminant source zone and the depth-integrated rate of contaminant mineralization. To this end, a field test was conducted at the Bemidji, MN, crude oil spill site. Results indicate that at the Bemidji site the CO(2)-efflux method is able to both delineate the source zone and distinguish between the rates of natural soil respiration and contaminant mineralization. The average CO(2)-efflux associated with contaminant degradation in the source zone is estimated at 2.6 ?mol m(-2) s(-1), corresponding to a total petroleum hydrocarbon mineralization rate (expressed as C(10)H(22)) of 3.3 g m(-2) day(-1). PMID:21142178

Sihota, Natasha J; Singurindy, Olga; Mayer, K Ulrich

2011-01-15

79

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

80

Hydrocarbon Contamination Decreases Mating Success in a Marine Planktonic Copepod  

PubMed Central

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

Seuront, Laurent

2011-01-01

81

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

EPA Science Inventory

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

82

PROTOZOA IN SUBSURFACE SEDIMENTS FROM SITES CONTAMINATED WITH AVIATION GASOLINE OR JET FUEL  

EPA Science Inventory

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. oreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gas...

83

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

Microsoft Academic Search

A numerical compositional simulator (Multiphase Multicomponent Nonisothermal Organics Transport Simulator (M2NOTS)) 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

A. E. Adenekan; T. W. Patzek; K. Pruess

1993-01-01

84

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

Microsoft Academic Search

A numerical compositional simulator [Multiphase Multicomponent Nonisothermal Organics Transport Simulator (M2NOTS)] 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

A. E. Adenekan; T. W. Patzek; K. Pruess

1993-01-01

85

MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE: PROCESSES  

EPA Science Inventory

Among the alternatives considered for the remediation of soil and ground water at hazardous wastes sites are the use of natural processes to reduce or remove the contaminants of concern. Under favorable conditions, the use of natural attenuation can result in significant cost sa...

86

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...

87

Magnetic properties changes due to hydrocarbon contaminated groundwater table fluctuations  

NASA Astrophysics Data System (ADS)

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

Ameen, Nawrass

2013-04-01

88

Using rational enzyme redesign to improve enzyme-mediated microbial dehalogenation of recalcitrant substances in deep-subsurface environments.  

National Technical Information Service (NTIS)

Heavily halogenated hydrocarbons are one of the most prevalent classes of man-made recalcitrant environmental contaminants and often make their way into subsurface environments. Biodegradation of heavily chlorinated compounds in the deep subsurface often ...

R. L. Ornstein

1993-01-01

89

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

90

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

91

Stimulating in situ surfactant production to increase contaminant bioavailability and augment bioremediation of petroleum hydrocarbons  

NASA Astrophysics Data System (ADS)

The effectiveness of a bioremediation strategy is largely dependent on relationships between contaminant sequestration (geochemical limitations) and microbial degradation potential (biological limitations). As contaminant bioavailability becomes mass transfer limited, contaminant removal will show less sensitivity to biodegradation enhancements without concurrent enhancements to rates of mass transfer into the bioavailable phase. Implementing a strategy that can simultaneously address geochemical and biological limitations is motivated by a subsurface zone of liquid petroleum hydrocarbons (LPH) contamination that is in excess of 10 acres (40,000 sq. meters). Biodegradation potential at the site is high; however, observed biodegradation rates are generally low, indicative of bioavailability limitations (e.g., low aqueous solubilities, nutrient deficiencies, and/or mass transfer limitations), and estimates indicate that bioremediation (i.e., biosparging/bioventing) with unaugmented biodegradation may be unable to achieve the remedial objectives within an acceptable time. Bench-scale experiments using soils native to the site provide evidence that, in addition to nutrient additions, a pulsed oxygen delivery can increase biodegradation rates by stimulating the microbial production of biosurfactants (rhamnolipids), leading to a reduction in surface tension and an increase in contaminant bioavailability. Pilot-scale tests at the field site are evaluating the effectiveness of stimulating in situ biosurfactant production using cyclic biosparging. The cyclic sparging creates extended periods of alternating aerobic and oxygen-depleted conditions in the submerged smear zone. The increased bioavailability of LPH and the resulting biodegradation enhancements during the test are evaluated using measurements of surface tension (as confirmation of biosurfactant accumulation) and nitrate concentrations (as substantiation of anaerobic biodegradation during shut-off periods). The successful promotion of in situ biosurfactant production during biosparging is expected to provide a cost effective solution to site remediation requirements.

Haws, N. W.; Bentley, H. W.; Yiannakakis, A.; Bentley, A. J.; Cassidy, D. P.

2006-12-01

92

Bioremediation of marine sediments contaminated by hydrocarbons: Experimental analysis and kinetic modeling  

Microsoft Academic Search

This work deals with bioremediation experiments on harbor sediments contaminated by aliphatic and polycyclic aromatic hydrocarbons (PAHs), investigating the effects of a continuous supply of inorganic nutrients and sand amendments on the kinetics of microbial growth and hydrocarbon degradation. Inorganic nutrients stimulated microbial growth and enhanced the biodegradation of low and high molecular weight hydrocarbons, whereas sand amendment increased only

Francesca Beolchini; Laura Rocchetti; Francesco Regoli; Antonio Dell’Anno

2010-01-01

93

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

Microsoft Academic Search

Chlorinated hydrocarbons (CHCs) are the most common contaminant found at hazardous waste sites and are the most prevalent contaminants on U.S. Department of Energy (DOE) weapons production sites. Many of the CHCs are either known or suspected carcinogens and thus pose health risks to the public and\\/or site workers. Unlike simple hydrocarbons, CHCs are resistant to biodegradation, but can degrade

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

2006-01-01

94

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

95

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

Microsoft Academic Search

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

A. E. Adenekan; T. W. Patzek; K. Pruess

1993-01-01

96

Bioremediation treatability assessment of hydrocarbon-contaminated soils from Eureka, Nunavut  

Microsoft Academic Search

The bioremediation potential of three hydrocarbon-contaminated soil samples with diverse soil physical\\/chemical characteristics from Eureka, Ellesmere Island, Nunavut, was assessed. Microbial enumeration by viable plate counts and MPN analyses combined with molecular analysis (PCR and colony hybridization) for hydrocarbon catabolic genes (alkB+, xylE+, ndoB+) demonstrated the presence of significant numbers of aerobic cold-adapted hydrocarbon-degrading organisms in the three contaminated soils.

L. G. Whyte; B. Goalen; J. Hawari; D. Labbé; C. W. Greer; M. Nahir

2001-01-01

97

Induced Polarization methodology: application to a hydrocarbon contaminated site  

NASA Astrophysics Data System (ADS)

Induced Polarization (IP) is a promising method for environmental studies (Vaudelet et al., 2011; Abdel Aal et al., 2006). This method has already been successful for the study of contaminations in the laboratory scale (Vanhala, 1997; Revil et al., 2011; Schmutz et al., 2012) but is still not trivial on the field. Temporal IP seems relatively common for field studies. When contamination implies a significative change of the polarization parameters, successful studies have been lead (Fiandaca et al. 2012; Dahlin et al., 2002 on landfills). Otherwise hydrocarbon contamination may induce small changes on IP parameters (Vaudelet et al., 2011). Spectral induced polarization has not been widely used for field application yet: this method is sensitive to coupling effects and time consuming. Moreover, all the phenomenon responsible of the signal is not completely understood yet (Kemna et al., 2012). The main aim of our presentation is about IP methodology, applied on site affected by a hydrocarbon contamination. In this case, precautions have to be taken to get explicit answers from the contamination. Field investigations have been made: chargeability measurements in order to delineate the free phase contamination extension and spectral induced polarization soundings in order to characterize more precisely the contamination. We would like to provide recommendations to improve induced polarization measurements especially on three aspects, (i) propose a different measurement sequence to make chargeability measurements and (ii) evaluate the influence of the current injection time on chargeability measurements (iii) give general precautions to achieve SIP measurements. A different new chargeability sequence is proposed integrating the use of separated injection and measure cables to avoid coupling phenomena in multicore cables. Indeed, this kind of coupling can significantly decrease the signal / noise ratio (Dahlin et al., 2012). Direct and reverse measurements have been made in order to evaluate if the data and data quality are comparable. Different times of injection have also been tested to evaluate their influence on chargeability measurements: long injection times (4 and 8 seconds) indicate the same high chargeability trend, to the contrary to small injection time (2 seconds). Long injection time generate (i) the polarization of more elements (ii) a stronger polarization of polarizable elements. For environmental purposes, long injection times are recommended. Spectral induced polarization soundings have been made using the SIP Fuchs device, with an amplifier in order to stabilize the injected current (Radic 2004). Unpolarizable measurement electrodes have been connected to the apparatus with optic fiber and metallic injection electrodes have been link with a specific cable arrangement, both to reduce coupling effect with the ground (Vaudelet et al., 2011; Ghorbani et al., 2007). These precautions give good quality result and allow the inversion of the data to obtain Cole Cole parameters (Ghorbani et al., 2007), useful for hydrogeological interpretations.

Blondel, Amelie; Schmutz, Myriam; Tichane, Frederic; Franceschi, Michel; Carles, Margaux

2013-04-01

98

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

EPA Science Inventory

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

99

Delineation of Hydrocarbon Contamination of Soils and Sediments With Environmental Magnetic Methods: Laboratory and Field Studies  

NASA Astrophysics Data System (ADS)

Hydrocarbon contamination of soils and sediments is a worldwide environmental problem. The present research focuses on the study of magnetic properties of hydrocarbon contaminated soils and sediments using environmental magnetic methods both on field sites as well as in laboratory batch experiments. The main objectives of this research are i) to determine a possible application of magnetic proxies for the delineation of organic contamination in soils and sediments and ii) to examine the role of bacteria in changing soil magnetic properties after hydrocarbon contamination. A former oil field and a former military site which are heavily contaminated with hydrocarbons were studied. Additionally, three different types of natural clean soils were investigated in laboratory experiments by simulating hydrocarbon contamination in sterile and microbial active setups. Magnetic properties, soil properties, iron bioavailability, iron redox state and hydrocarbon content of samples were measured. Additionally, magnetic susceptibility (MS) was monitored weekly in laboratory batch set-ups during several months. Results from the field sites showed that there is an increase of MS and a good correlation between MS and hydrocarbon content. A weekly monitored MS result from the laboratory study clearly indicated~~10% change (increase as well as decrease) of initial MS of respective soils only in microbial active set-ups with saturation after a few weeks of experimental period. This depicts that there is a change of MS caused by microbial iron mineral transformation in presence of hydrocarbon contamination in soils. The results from the field study demonstrate that magnetic proxies can be used to localize hydrocarbon contamination. However, more field sites with hydrocarbon contaminated soils and sediments need to be investigated by using environmental magnetic methods for better understanding the factors driving such changes in magnetic properties.

Rijal, M. L.; Appel, E.; Porsch, K.; Kappler, A.; Blaha, U.; Petrovsky, E.

2008-12-01

100

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

NASA Astrophysics Data System (ADS)

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

Cunningham, A.

2002-05-01

101

Remediation of contaminated subsurface materials by a metal-reducing bacterium  

SciTech Connect

A biotic approach for remediating subsurface sediments and groundwater contaminated with carbon tetrachloride (CT) and chromium was evaluated. Cells of the Fe(iii)-reducing bacterium strain BrY were added to sealed, anoxic flasks containing Hanford groundwater, natural subsurface sediments, and either carbon tetrachloride, CT, or oxidized chromium, Cr(VI). With lactate as the electron donor, BrY transformed CT to chloroform (CF), which accumulated to about 1 0 % of the initial concentration of CT. The remainder of the CT was transformed to unidentified, nonvolatile compounds. Transformation of CT by BrY was an indirect process Cells reduced solid phase Fe(ill) to chemically reactive FE(II) that chemically transformed the chlorinated contaminant. Cr(VI), in contrast, was reduced by a direct enzymatic reaction in the presence or absence of Fe(III)-bearing sediments. These results demonstrate that Fe(ill)-reducing bacteria provide potential for transforming CT and for reducing CR(VI) to less toxic Cr(III). Technologies for stimulating indigenous populations of metal-reducing bacteria or for introducing specific metal-reducing bacteria to the subsurface are being investigated.

Gorby, Y.A.; Amonette, J.E.; Fruchter, J.S.

1994-11-01

102

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

SciTech Connect

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

Krupka, Kenneth M.; Martin, Wayne J.

2001-07-23

103

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.

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

104

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

PubMed Central

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

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

2010-01-01

105

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

PubMed

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

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

2010-05-01

106

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

SciTech Connect

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

Ruggiero, Christy

2005-06-01

107

Interactions between subsurface microbial assemblages and mixed organic and inorganic contaminant systems  

SciTech Connect

Metals are introduced into aquatic environments as results of mining and refining of ores and other human activities, such as combustion of fossil fuels, spraying of pesticides, and disposal of domestic and industrial wastes. Synthetic chelating agents have been used for nuclear decontamination, waste processing, and detergent industry because they react with radionuclides and heavy metal ions and form stable water-soluble complexes. Co-disposal of synthetic chelating agents with radionuclides and/or heavy metals at some landfill sites for energy and industrial wastes have caused increase in organic-inorganic mixtures transport in the subsurface environment. The extensive presence and the possible persistence of these waste mixtures in those environments underlines the need to study their effects on aquatic microbial assemblages. To remediate a contaminated aquifer, the microorganisms must not be severely inhibited by the chemical pollutants. In this research, the effects of selected chemical contaminants (organic and inorganic species) on ground water bacteria and a mixture of model organic and inorganic chemicals (i.e., imidazole and copper) on surface and subsurface bacteria were determined. Adaptation of microorganisms to in situ contaminants may be the prerequisite for microbial degradation to occur. In addition, some environmental factors such as concentrations of inorganic nutrients may limit or affect biodegradation of subsurface organic pollutants. Microbial degradative activity in ground water of a chemical waste landfill site in Georgia and in ground water samples from California were the focus of this study. Effects of inorganic nutrients on microbial degradation of toluene, p-cresol, and phenol in ground waters were evaluated. 14 refs., 3 figs., 1 tab.

Hwang, H.M.; Loya, J.A. (Jackson State Univ., MS (United States)); Perry, D.L. (Lawrence Berkeley Lab., CA (United States)); Scholze, R. (Army Construction Engineering Research Lab., Champaign, IL (United States))

1994-11-01

108

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

109

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

EPA Science Inventory

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

110

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

EPA Science Inventory

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

111

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

EPA Science Inventory

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

112

Hydrocarbon stress response of four tropical plants in weathered crude oil contaminated soil in microcosms  

Microsoft Academic Search

Responses to hydrocarbon stress of four tropical plants Panicum maximum, Zea mays, Centrosema sp. and Pueraria sp. grown in crude oil contaminated soils (1%, 5% and 10% w\\/w) were evaluated in a green house. Plants’ percentage survival, shoot heights, biomass development, and phytotoxicity susceptibility were used as indicators of growth, stress response and hydrocarbon tolerance. Relative to control, shoot heights

Ifechukwu E. Adieze; Justina C. Orji; Rose N. Nwabueze; G. O. C. Onyeze

2012-01-01

113

Transcriptome of Geobacter uraniireducens growing in uranium-contaminated subsurface sediments.  

PubMed

To learn more about the physiological state of Geobacter species living in subsurface sediments, heat-sterilized sediments from a uranium-contaminated aquifer in Rifle, Colorado, were inoculated with Geobacter uraniireducens, a pure culture representative of the Geobacter species that predominates during in situ uranium bioremediation at this site. Whole-genome microarray analysis comparing sediment-grown G. uraniireducens with cells grown in defined culture medium indicated that there were 1084 genes that had higher transcript levels during growth in sediments. Thirty-four c-type cytochrome genes were upregulated in the sediment-grown cells, including several genes that are homologous to cytochromes that are required for optimal Fe(III) and U(VI) reduction by G. sulfurreducens. Sediment-grown cells also had higher levels of transcripts, indicative of such physiological states as nitrogen limitation, phosphate limitation and heavy metal stress. Quantitative reverse transcription PCR showed that many of the metabolic indicator genes that appeared to be upregulated in sediment-grown G. uraniireducens also showed an increase in expression in the natural community of Geobacter species present during an in situ uranium bioremediation field experiment at the Rifle site. These results demonstrate that it is feasible to monitor gene expression of a microorganism growing in sediments on a genome scale and that analysis of the physiological status of a pure culture growing in subsurface sediments can provide insights into the factors controlling the physiology of natural subsurface communities. PMID:18843300

Holmes, Dawn E; O'Neil, Regina A; Chavan, Milind A; N'Guessan, Lucie A; Vrionis, Helen A; Perpetua, Lorrie A; Larrahondo, M Juliana; DiDonato, Raymond; Liu, Anna; Lovley, Derek R

2009-02-01

114

REFLECTANCE SPECTROSCOPY AS A RAPID TOOL FOR QUALITATIVE MAPPING AND CLASSIFICATION OF HYDROCARBONS SOIL CONTAMINATION  

Microsoft Academic Search

Petroleum hydrocarbons are contaminants of particular significance. With production rates of 13.26 million cubic meters of crude oil per day, their potential as soil and water contaminant is apparent. The most 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

G. Schwartz; G. Eshel; M. Ben-Haim; E. Ben-Dor

115

Enhancing technology acceptance: The role of the subsurface contaminants focus area external integration team  

SciTech Connect

The US DOE is developing and deploying innovative technologies for cleaning up its contaminated facilities using a market-oriented approach. This report describes the activities of the Subsurface Contaminant Focus Area`s (SCFA) External Integration Team (EIT) in supporting DOE`s technology development program. The SCFA program for technology development is market-oriented, driven by the needs of end users. The purpose of EIT is to understand the technology needs of the DOE sites and identify technology acceptance criteria from users and other stakeholders to enhance deployment of innovative technologies. Stakeholders include regulators, technology users, Native Americans, and environmental and other interest groups. The success of this national program requires close coordination and communication among technology developers and stakeholders to work through all of the various phases of planning and implementation. Staff involved must be willing to commit significant amounts of time to extended discussions with the various stakeholders.

Kirwan-Taylor, H.; McCabe, G.H. [Battelle Seattle Research Center, WA (United States); Lesperance, A. [Pacific Northwest National Lab., Richland, WA (United States); Kauffman, J.; Serie, P.; Dressen, L. [EnvironIssues (United States)

1996-09-01

116

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

PubMed

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

Lee, Kenneth Y

2008-12-15

117

Innovative technology for expedited site remediation of extensive surface and subsurface contamination  

SciTech Connect

Large scale surface and subsurface contamination resulted from numerous releases of feed stock, process streams, waste streams, and final product at a major chemical plant. Soil and groundwater was contaminated by numerous compounds including lead, tetraethyl lead, ethylene dibromide, ethylene dichloride, and toluene. The state administrative order dictated that the site be investigated fully, that remedial alternative be evaluated, and that the site be remediated within a year period. Because of the acute toxicity and extreme volatility of tetraethyl lead and other organic compounds present at the site and the short time frame ordered by the regulators, innovative approaches were needed to carry out the remediation while protecting plant workers, remediation workers, and the public.

Audibert, J.M.E.; Lew, L.R.

1994-12-31

118

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

119

Bioremediation of marine sediments contaminated by hydrocarbons: experimental analysis and kinetic modeling.  

PubMed

This work deals with bioremediation experiments on harbor sediments contaminated by aliphatic and polycyclic aromatic hydrocarbons (PAHs), investigating the effects of a continuous supply of inorganic nutrients and sand amendments on the kinetics of microbial growth and hydrocarbon degradation. Inorganic nutrients stimulated microbial growth and enhanced the biodegradation of low and high molecular weight hydrocarbons, whereas sand amendment increased only the removal of high molecular weight compounds. The simultaneous addition of inorganic nutrients and sand provided the highest biodegradation (>70% for aliphatic hydrocarbons and 40% for PAHs). A semi-empirical kinetic model was successfully fitted to experimental temporal changes of hydrocarbon residual concentrations and microbial abundances. The estimated values for parameters allowed to calculate a doubling time of 2.9 d and a yield coefficient biomass/hydrocarbons 0.39 g C biomass g-1C hydrocarbons, for the treatment with the highest hydrocarbon biodegradation yield. A comparison between the organic carbon demand and temporal profiles of hydrocarbons residual concentration allowed also to calculate the relative contribution of contaminants to carbon supply, in the range 5-32%. This suggests that C availability in the sediments, influencing prokaryotic metabolism, may have cascade effects on biodegradation rates of hydrocarbons. Even if these findings do not represent a general rule and site-specific studies are needed, the approach used here can be a relevant support tool when designing bioremediation strategies on site. PMID:20609514

Beolchini, Francesca; Rocchetti, Laura; Regoli, Francesco; Dell'Anno, Antonio

2010-10-15

120

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

Microsoft Academic Search

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

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

2009-01-01

121

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

NASA Astrophysics Data System (ADS)

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

Bonaccorsi, R.; Stoker, C. R.

2006-12-01

122

A composite modeling approach for subsurface transport of degrading contaminants from land-disposal sites  

NASA Astrophysics Data System (ADS)

A composite modeling approach is presented for simulating the three-dimensional (3-D) subsurface transport of dissolved contaminants with transformation products. The approach is based on vertical infiltration and contaminant transport in the unsaturated zone and 3-D groundwater flow and contaminant migration in the saturated zone. Moisture movement and groundwater flow are considered to be steady, but contaminant transport is treated as transient. The model allows for advection, dispersion, linear or nonlinear equilibrium sorption, and first-order biochemical transformation of either a single contaminant species, or a multi-species, straight or branched, decay chain. The model is designed for regulatory decision making using Monte Carlo analysis. For such applications considerable emphasis is placed on computational efficiency and robustness of the model. An efficient and robust semi-analytical method is used to perform the steady-state solution for infiltration through the unsaturated zone. A variety of transport solutions, corresponding to transient or steady state, and linear or nonlinear sorption conditions, are incorporated in the model. For transient linear transport, the Laplace transform technique is used. The transformed unsaturated-zone transport equation is solved analytically; the transformed saturated-zone transport is solved numerically using the Laplace transform-Galerkin (LTG) technique which permits a nonuniform groundwater flow field, reflecting the influence of locally higher infiltration from the waste source. The model contains fully 3-D solutions for flow and transport in the saturated zone, as well as two-dimensional solutions for vertical cross-sectional and areal scenarios. Model formulations and solution schemes are verified by comparison against a fully 3-D, variably saturated flow and transport code for a hypothetical problem which represents a typical landfill. The model is applied also to simulate a controlled release field experiment and the model predictions compare well with groundwater monitoring data for the site.

Kool, J. B.; Huyakorn, P. S.; Sudicky, E. A.; Saleem, Z. A.

1994-11-01

123

In situ measurements of subsurface contaminants with a multi-channel laser-induced fluorescence system  

NASA Astrophysics Data System (ADS)

A new multi-channel laser-induced fluorescence (LIF) probe with novel optical fiber probe geometry has been designed and integrated into a cone penetrometer testing (CPT) system for in situ contamination detection. The system is capable of collecting excitation and emission matrices (EEMs) of subsurface contaminants as a function of depth in seconds. Compared to our previous multi-channel LIF-CPT system, the new system is faster and more compact, with reduced probe size and sampling area. This article describes the first field demonstration of the system at Hanscom Air Force Base, Massachusetts. One contaminated site within the base was characterized through in situ measurements of 26 LIF-CPT pushes. To validate the LIF results, core samples taken at five locations were analyzed by both on-site LIF measurements and by off-site laboratory analyses with EPA methods. The comparison of the LIF and laboratory results is presented, along with the results of the in situ measurements.

Wu Pepper, Jane; Wright, Andrew O.; Kenny, Jonathan E.

2002-01-01

124

Assessing of Conceptual Models for Subsurface Reactive Transport of Inorganic Contaminants  

NASA Astrophysics Data System (ADS)

In many subsurface situations where human health and environmental quality are at risk (e.g., contaminant hydrogeology, petroleum extraction, carbon sequestration, etc.), scientists and engineers are being asked by federal agency decision-makers to predict the fate of chemical species under conditions where both reactions and transport are processes of first-order importance. In 2002, a working group (WG) was formed by representatives of the U.S. Geological Survey, Environmental Protection Agency, Department of Energy, Nuclear Regulatory Commission, Department of Agriculture, and Army Engineer Research and Development Center to assess the role of reactive transport modeling (RTM) in addressing these situations. Specifically, the goals of the WG are to (1) evaluate the state of the art in conceptual model development and parameterization for RTM, as applied to soil, vadose zone, and groundwater systems, and (2) prioritize research directions that would enhance the practical utility of RTM.

Davis, James A.; Yabusaki, Steven B.; Steefel, Carl I.; Zachara, John M.; Curtis, Gary P.; Redden, George D.; Criscenti, Louise J.; Honeyman, Bruce D.

2004-11-01

125

Using radon-222 in soil gas as an indicator of subsurface contamination by non-aqueous phase-liquids (NAPLs)  

Microsoft Academic Search

The dependence of the soil gas radon concentration on ground contamination by non-aqueous phase-liquids (NAPLs) was studied. Subsurface NAPL contamination is known as one of the major problems concerning the clean-up of polluted industrial sites. One reason is the mostly limited number of soil sampling locations, which makes adequate tracing of the extent of contami- nation difficult. With the aim

M. Schubert; K. Freyer; H. C. Treutler; H. Weiss

2002-01-01

126

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

127

Control of petroleum-hydrocarbon contaminated groundwater by intrinsic and enhanced bioremediation.  

PubMed

In the first phase of this study, the effectiveness of intrinsic bioremediation on the containment of petroleum hydrocarbons was evaluated at a gasoline spill site. Evidences of the occurrence of intrinsic bioremediation within the BTEX (benzene, toluene, ethylbenzene, and xylenes) plume included (1) decreased BTEX concentrations; (2) depletion of dissolved oxygen (DO), nitrate, and sulfate; (3) production of dissolved ferrous iron, methane, and CO2; (4) deceased pH and redox potential; and (5) increased methanogens, total heterotrophs, and total anaerobes, especially within the highly contaminated areas. In the second phase of this study, enhanced aerobic bioremediation process was applied at site to enhance the BTEX decay rates. Air was injected into the subsurface near the mid-plume area to biostimulate the naturally occurring microorganisms for BTEX biodegradation. Field results showed that enhanced bioremediation process caused the change of BTEX removal mechanisms from anaerobic biodegradation inside the plume to aerobic biodegradation. This variation could be confirmed by the following field observations inside the plume due to the enhanced aerobic bioremediation process: (1) increased in DO, CO2, redox potential, nitrate, and sulfate, (2) decreased in dissolved ferrous iron, sulfide, and methane, (3) increased total heterotrophs and decreased total anaerobes. Field results also showed that the percentage of total BTEX removal increased from 92% to 99%, and the calculated total BTEX first-order natural attenuation rates increased from 0.0092% to 0.0188% per day, respectively, after the application of enhanced bioremediation system from the spill area to the downgradient area (located approximately 300 m from the source area). PMID:20923098

Chen, Ku-Fan; Kao, Chih-Ming; Chen, Chiu-Wen; Surampalli, Rao Y; Lee, Mu-Sheng

2010-01-01

128

The effect of hydrocarbon contamination on the accumulation of lipids in soils  

NASA Astrophysics Data System (ADS)

The effect of hydrocarbon contamination on the accumulation of lipids in soils is discussed. The field study was performed in the Shchelkovo district of Moscow oblast on soddy-podzolic soils contaminated with hydrocarbons in low concentrations along the entire profile. It was shown that the transformation of the hydrocarbons under the particular soil-geochemical conditions follows the way of the formation of incompletely oxidized compounds that are analytically determined in the fraction of the lipids. A significant increase in the concentration of lipids was found in the lower horizons of the semihydromorphic and hydromorphic soils under conditions of excessive moistening and a low redox potential. There was no increase in the concentration of the lipids in the upper soil horizons with their optimum water content and high values of the redox potential, which could be due to the complete oxidation of the hydrocarbons to carbon dioxide and water.

Lisovitskaya, O. V.; Mozharova, N. V.

2013-06-01

129

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...

130

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

PubMed Central

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

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

2013-01-01

131

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

PubMed

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

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

2013-01-01

132

Petroleum hydrocarbon contamination of the Southern Black Sea Shelf, Turkey  

Microsoft Academic Search

Introduction  In this study, total petroleum hydrocarbon (TPH) contents and some aliphatic and aromatic hydrocarbon concentrations were\\u000a analysed in coastal sediments of hot points collected from along the Southern Black Sea Shelf.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Surface sediment (0–2 cm) samples were collected from the locations using a Van Veen type grab sampler in September 2008 during\\u000a a cruise on the Pollution Monitoring

Nuray Balk?s; Abdullah Aksu; Mahmut S. Er?an

133

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

Microsoft Academic Search

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

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

2009-01-01

134

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

PubMed

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

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

2013-01-01

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

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

PubMed

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 H(2)O(2) 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, J L; Kampbell, D H; Cook, M L; Wilson, J T

1993-02-01

137

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.

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

1993-01-01

138

Applying model abstraction techniques to optimize monitoring networks for detecting subsurface contaminant transport  

NASA Astrophysics Data System (ADS)

Improving strategies for monitoring subsurface contaminant transport includes performance comparison of competing models, developed independently or obtained via model abstraction. Model comparison and parameter discrimination involve specific performance indicators selected to better understand subsurface contaminant transport to optimize groundwater monitoring networks (GMN). Three abstraction techniques were validated for GMN design: (1) using pedotransfer functions, (2) profile aggregation, and (3) limiting the input domain by ignoring the unsaturated zone. Data were collected in the tracer experiment at the USDA-ARS OPE3 integrated research site. A pulse of a potassium chloride solution was applied to a 13m x14 m irrigation plot, and chloride concentrations were measured in the groundwater at three sampling depths in 12 observations wells installed at distances of 7 m and 14 m from the irrigation plot. The spatial distribution of soil materials was obtained from cores taken at 0.2 m increments to the depth of 2 m during installation of the observation wells. Soil hydraulic conductivity values were obtained from the HYDRUS-3D calibration with chloride concentration time series measured in the observation wells, and soil water retention was estimated from pedotransfer functions. The model abstraction techniques were evaluated using HYDRUS-3D simulations performed for different hydrologic scenarios. These scenarios included three weather, two ground-water depth, and two groundwater slope scenarios, as well as two different locations of the contaminant release selected within the irrigation plot. The weather scenarios were based on 25%, 50% and 75% of the 10-year probability of mean annual precipitation. The monitoring locations for GMN were selected based on three performance indicators: the peak concentration (Cpeak), the time to the peak concentration (Tpeak) and total chemical flux (QC). The monitoring locations were selected based on (a) more frequent, and (b) more probable and persistent appearance of maximum or minimum values of the above performance indicators. Cpeak and QC appeared to be more reliable performance indicators compared to Tpeak. The profile aggregation method was found to be the only abstraction technique that generated a GMN differed from the network obtained using the calibrated HYDRUS-3D model based on Cpeak and QC performance indicators. The outcome of this study provides reasonable assurance that model abstraction techniques can be used to optimize monitoring network strategies, and can provide specific the information for the future data collection and abstraction efforts to optimize a GMN.

Pachepsky, Y. A.; Guber, A.; Gish, T. J.; Yakirevich, A.; Nicholson, T. J.; Cady, R.

2012-12-01

139

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

140

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

PubMed Central

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

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

2012-01-01

141

Oxidation of polycyclic aromatic hydrocarbons by fungal isolates from an oil contaminated refinery soil  

Microsoft Academic Search

Background and Objective  Indigenous soil microorganisms are used for the biodegradation of petroleum hydrocarbons in oily waste residues from the petroleum\\u000a refining industry. The objective of this investigation was to determine the potential of indigenous strains of fungi in soil\\u000a contaminated with petroleum hydrocarbons to bio-degrade polycyclic aromatic hydrocarbons (PAH).\\u000a \\u000a \\u000a \\u000a Materials and Methods  Twenty one fungal strains were isolated from a soil

Zhongming Zheng; Jeffrey P. Obbard

2003-01-01

142

Polycyclic aromatic hydrocarbons in Estonian soil: contamination and profiles  

Microsoft Academic Search

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

M Trapido

1999-01-01

143

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

144

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

145

EFFECTS OF BREATHING AIR CONTAINING CONTAMINANTS SUCH AS CO2, CO AND HYDROCARBONS AT 1 AND 5 ATMOSPHERES  

EPA Science Inventory

The neural and behavioral effects of air contaminants such as CO2, CO and hydrocarbons are reviewed. Each contaminant or contaminant class is reviewed separately and then an attempt is made to estimate effects of combinations of contaminants. The effects are reviewed for both nor...

146

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

SciTech Connect

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

Benignus, V.A.

1987-11-01

147

Polycyclic aromatic hydrocarbons degradation by composting in a soot-contaminated alkaline soil  

Microsoft Academic Search

This study deals with the biodegradation of the polycyclic aromatic hydrocarbons (PAH)s present in a soil contaminated by soot waste, characterised by a total PAHs content in the 200mgkg?1 range. A challenging characteristic of the waste soil treated was its high alkalinity, with a pH of about 12.8. The waste came from a soot-contaminated area located in the industrial zone

L. M. Moretto; S. Silvestri; P. Ugo; G. Zorzi; F. Abbondanzi; C. Baiocchi; A. Iacondini

2005-01-01

148

Ecotoxicological and microbiological characterization of soils from heavy-metal- and hydrocarbon-contaminated sites  

Microsoft Academic Search

The aims of this study were to characterize soils from industrial sites by combining physicochemical, microbiological, and\\u000a ecotoxicological parameters and to assess the suitability of these assays for evaluation of contaminated sites and ecological\\u000a risk assessment. The soil samples were taken from long-term contaminated sites containing high amounts of heavy metals (sites\\u000a 1 and 2) or petroleum hydrocarbons (site 3)

Gra?yna A. P?aza; Grzegorz Na??cz-Jawecki; Onruthai Pinyakong; Paul Illmer; Rosa Margesin

2010-01-01

149

Subsurface Distribution of Hydrocarbons in the Building 403 Area at LLNL.  

National Technical Information Service (NTIS)

The loss of 9000 to 17,500 gallons of regular gasoline from an underground tank in the Building 403 area was investigated. Samples of saturated and unsaturated soil and ground water were collected and analyzed for total gasoline hydrocarbons and/or aromat...

M. D. Dresen F. Hoffman S. Lovejoy

1986-01-01

150

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

SciTech Connect

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

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

1994-03-01

151

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

152

Venting for the removal of hydrocarbon vapors from gasoline contaminated soil  

Microsoft Academic Search

The utilization of a venting strategy to remove gasoline vapors from contaminated soil strata was investigated in this exper?ment. A contained gasoline “leak”; was created in a large outdoor facility which simulated soil strata and a static water table. An air flow was established, and vapor samples taken before, during, and after venting were checked for hydrocarbon content. The effluent

J. Scott Thornton; Wilford L. Wootan Jr

1982-01-01

153

Petroleum–hydrocarbon contamination and remediation by microbioventing at subAntarctic Macquarie Island  

Microsoft Academic Search

Natural attenuation of petroleum hydrocarbons in polar and subpolar soils is limited by low nutrients, low temperatures, and water availability. This study investigated three sites contaminated with diesel fuel and the use of aeration to remediate one of the sites at sub-Antarctic Macquarie Island. These sites were of differing ages and had different soil–water regimes. The most recent spill (New

John L. Rayner; Ian Snape; James L. Walworth; Paul Mc A. Harvey; Susan H. Ferguson

2007-01-01

154

Are Microbial Nanowires Responsible for Geoelectrical Changes at Hydrocarbon Contaminated Sites?  

Microsoft Academic Search

Significant advances in near-surface geophysics and biogeophysics in particular, have clearly established a link between geoelectrical response and the growth and enzymatic activities of microbes in geologic media. Recent studies from hydrocarbon contaminated sites suggest that the activities of distinct microbial populations, specifically syntrophic, sulfate reducing, and dissimilatory iron reducing microbial populations are a contributing factor to elevated sediment conductivity.

C. Hager; E. A. Atekwana; Y. A. Gorby; J. W. Duris; J. P. Allen; C. Ownby; S. Rossbach

2007-01-01

155

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...

156

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...

157

Recycling of solvent used in a solvent extraction of petroleum hydrocarbons contaminated soil  

Microsoft Academic Search

The application of water washing technology for recycling an organic composite solvent consisting of hexane and pentane (4:1; TU-A solvent) was investigated for extracting total petroleum hydrocarbons (TPH) from contaminated soil. The effects of water volume, water temperature, washing time and initial concentration of solvent were evaluated using orthogonal experiments followed by single factor experiments. Our results showed that the

Guozhong Wu; Xingang Li; Frédéric Coulon; Hong Li; Jingyan Lian; Hong Sui

2011-01-01

158

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

Microsoft Academic Search

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

Lisa M. Gieg; R. S. Tanner; S. H. Jr. Harris; K. L. Sublette; J. M. Suflita; R. V. Kolhatkar

1999-01-01

159

Statistical Evaluation of Geochemical Parameter Distribution in a Ground Water System Contaminated with Petroleum Hydrocarbons  

Microsoft Academic Search

acterize the water types. However, interpretations based on the above methods using major chemical species may A shallow-depth ground water area was investigated to identify be misleading or ineffective for a petroleum-contami- the dominant processes governing the distribution of hydrocarbon contaminants and hydrogeochemical parameters. The ground water nated ground water system, because there are other in the study site has

Jin-Yong Lee; Jeong-Yong Cheon; Kang-Kun Lee; Seok-Young Lee; Min-Hyo Lee

2001-01-01

160

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

161

Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium  

USGS Publications Warehouse

A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached from soil by application of the CBM water and traces native salt mobilization to groundwater. Resulting selenium concentrations in groundwater at this alluvial site were generally low (0.5–23 ?g/L) compared to Wyoming’s agricultural use suitability standard (20 ?g/L).

Bern, Carleton R.; Engle, Mark A.; Boehlke, Adam R.; Zupancic, John W.

2013-01-01

162

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

163

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...

164

User's Guide to the Collection and Analysis of Tree Cores to Assess the Distribution of Subsurface Volatile Organic Compounds.  

National Technical Information Service (NTIS)

Analysis of the volatile organic compound content of tree core is an inexpensive, rapid, simple approach to examining the distribution of subsurface volatile compound contaminants. The method has been shown to detect several volatile petroleum hydrocarbon...

D. A. Vroblesky

2008-01-01

165

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

166

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

167

Biomarkers for Great Lakes priority contaminants: halogenated aromatic hydrocarbons.  

PubMed Central

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

Feeley, M M

1995-01-01

168

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

Microsoft Academic Search

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

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

2007-01-01

169

Leaching of human pathogens in repacked soil lysimeters and contamination of potato tubers under subsurface drip irrigation in Denmark  

Microsoft Academic Search

The risk for contamination of potatoes and groundwater through subsurface drip irrigation with low quality water was explored in 30 large-scale lysimeters containing repacked coarse sand and sandy loam soils. The human pathogens, Salmonella Senftenberg, Campylobacter jejuni and Escherichia coli O157:H7, and the virus indicator Salmonella Typhimurium bacteriophage 28B, were added weekly through irrigation tubes for one month with low

Anita Forslund; Finn Plauborg; Mathias Neumann Andersen; Bo Markussen; Anders Dalsgaard

2011-01-01

170

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

171

Anaerobic degradation of polycyclic aromatic hydrocarbons and alkanes in petroleum-contaminated marine harbor sediments.  

PubMed Central

Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaerobic 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 carbon dioxide in these sediments, while pyrene and benzo[a]pyrene were not. Studies with naphthalene indicated that PAH oxidation was sulfate dependent. Incubating the sediments with additional naphthalene for 1 month resulted in a significant increase in the oxidation of [14C]naphthalene. In sediments from a less heavily contaminated site in San diego Bay where PAHs were not readily degraded, naphthalene degradation could be stimulated through inoculation with active PAH-degrading sediments from the most heavily contaminated site. Sediments from the less heavily contaminated site that had been adapted for rapid anaerobic degradation of high concentrations of benzene did not oxidize naphthalene, suggesting that the benzene- and naphthalene-degrading populations were different. When fuels containing complex mixtures of alkanes were added to sediments from the two sites, there was significant degradation in the alkanes. [14C]hexadecane was also anaerobically oxidized to 14CO2 in these sediments. Molybdate, a specific inhibitor of sulfate reduction, inhibited hexadecane oxidation. These results demonstrate that a wide variety of hydrocarbon contaminants can be degraded under sulfate-reducing conditions in hydrocarbon-contaminated sediments, and they suggest that it may be possible to use sulfate reduction rather than aerobic respiration as a treatment strategy for hydrocarbon-contaminated dredged sediments.

Coates, J D; Woodward, J; Allen, J; Philp, P; Lovley, D R

1997-01-01

172

Distribution and geochemistry of contaminated subsurface waters in fissured volcanogenic bed rocks of the Lake Karachai Area, Chelyabinsk, Southern Urals  

SciTech Connect

The present investigation is devoted to the study of the distribution and geochemistry of contaminated subsurface waters, beneath the site of temporary storage of liquid radioactive waste known as Lake Karachai. For this purpose a method of hydrogeochemical logging (HGCL) together with standard hydrogeochemical and geophysical methods of uncased hole logging were used. The distribution of sodium nitrate brine plumes in the subsurface was determined by the physical and physico-chemical properties of these brines and by the petrochemical composition of enclosing rocks and the structural setting of the flow paths. The latter is represented by fractures and large faults in the bedrock of volcanogenic and volcanogenic-sedimentary rocks of intermediate-to-basic composition. The volcanogenic rocks are overlain in some places by a thin cover of unconsolidated sediments, i.e., by loams and relatively impermeable silts. Contaminated waters flow-in accordance with the eluvium bottom relief towards local areas of natural (Mishelyak and Techa rivers) and artificial (Novogomenskii water intake) discharge of subsurface waters. The large Mishelyak fault, southwest of Lake Karachai and under fluvial sediments of the Mishelyak, is assumed to significantly influence the flow pattern of contaminated waters, diverting them from an intake of drinking water.

Solodov, I.N.; Belichkin, V.I.; Zotov, A.V.; Kochkin, B.T. [Russian Academy of Sciences, Moscow (Russian Federation); Drozhko, E.G. [Atomic Energy of Russia (Russian Federation); Glagolev, A.V.; Skokov, A.N. [Russian Federation Committee on Geological and Subsurface Usage (Russian Federation)

1994-06-01

173

Study to determine the feasibility of using a ground-penetrating radar for more-effective remediation of subsurface contamination  

SciTech Connect

Remediation of hazardous material spills is often costly and entails cumbersome procedures. The 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. The denser the sampling grid, the more effective it is; unfortunately, it is also more expensive to implement and more damaging to the environment. A nonintrusive method for detecting subsurface contamination, therefore, would be highly desirable. Toward this end, the capability of ground-penetrating radar (GPR) to identify natural subsurface features, detect man-made objects buried in the soil, and both detect and define the extent of contaminated soil or groundwater was assessed. The study concluded that the technology for the envisioned GPR already exists. In terms of hardware, it was found that a synthetic-pulse radar has the potential to operate effectively in the three types of subsurface environments modeled in the study, environments representative of seven out of ten 'common cases' found at remediation sites.

Douglas, D.G.; Burns, A.A.; Rino, C.L.; Maresca, J.W.

1992-05-01

174

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

175

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

176

Influence of in situ steam formation by radio frequency heating on thermodesorption of hydrocarbons from contaminated soil.  

PubMed

Thermal desorption of a wide spectrum of organic contaminants, initiated by radio frequency (RF) heating, was studied at laboratory and pilot-plant scales for an artificially contaminated soil and for an originally contaminated soil from an industrial site. Up to 100 °C, moderate desorption rates were observed for light aromatics such as toluene, chlorobenzene, and ethylbenzene. Desorption of the less volatile contaminants was greatly enhanced above 100 °C, when fast evaporation of soil-water produced steam for hydrocarbon stripping (steam-distillation, desorption rates increased by more than 1 order of magnitude). For hydrocarbons with low water solubility (e.g., aliphatic hydrocarbons), the temperature increase above 100 °C after desiccation of soil again led to a significant increase of the removal rates, thus showing the impact of hydrocarbon partial pressure. RF heating was shown to be an appropriate option for thermally enhanced soil vapor extraction, leading to efficient cleaning of contaminated soils. PMID:21105642

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

2010-12-15

177

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

178

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

179

Coupling methodology and application of a fully integrated model for contaminant transport in the subsurface system  

NASA Astrophysics Data System (ADS)

An efficient integrated modeling approach is developed to simulate the contaminant transport in the subsurface system. The unsaturated zone is divided into a number of horizontal sub-areas according to the atmospheric boundary conditions, land use types and hydrological conditions. Solute migration through the unsaturated zone of each sub-area is assumed to be vertical and can be represented by the one-dimensional advection-dispersion equation, which is then coupled to the three-dimensional advection-dispersion equation representing the subsequent groundwater transport. The finite element method is adopted to discretize the vertical solute equation, while the hybrid finite element and finite difference method is used to discretize the three-dimensional saturated solute transport equation, which is split into the horizontal and vertical equations based on the concept of the horizontal/vertical splitting. The unsaturated and saturated solute transport equations are combined into a unified matrix by the mass balance analysis for the adjacent nodes located at the one-dimensional soil column and at the water table. Two hypothetical cases and two field cases are simulated to test the validity of the model with the results compared with those from HYDRUS-1D, SWMS2D and the measured data. The limitations of the model are discussed as well. The analysis of the four cases demonstrates that the proposed model can calculate the water flow and solute transport reasonably even with complex boundary and variable topography conditions. It also shows that the model is efficient to simulate the water flow and solute transport in regional-scale areas with small computational costs. However, the model will lose accuracy when the lateral dispersion effect is dominant in the unsaturated zone.

Zhu, Yan; Shi, Liangsheng; Yang, Jinzhong; Wu, Jingwei; Mao, Deqiang

2013-09-01

180

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

181

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

PubMed Central

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

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

2006-01-01

182

Transport and Degradation of Semivolatile Hydrocarbons in a Petroleum-Contaminated Aquifer, Bemidji, Minnesota  

USGS Publications Warehouse

Polycyclic aromatic hydrocarbons (PAH) were used as probes to identify the processes controlling the transport and fate of aqueous semivolatile hydrocarbons (SVHCs) in a petroleum-contaminated aquifer near Bemidji, Minnesota. PAH and other SVHCs were isolated from ground water by field solid-phase extraction and analyzed using gas chromatography/mass spectrometry. Close to the oil body, aqueous aliphatic hydrocarbon compositions are substantially different from the parent oil, suggesting microbial alteration prior to or during dissolution. Aqueous PAH concentrations are elevated above oil-water equilibrium concentrations directly beneath the oil and decrease dramatically at distances ranging from the 25 to 65 m downgradient from the leading edge of the oil body. Variations in downgradient distributions of naphthalene, fluorene and phenanthrene, coupled with their biodegradation, partitioning and volatility characteristics, suggest that the PAH are useful probes for distinguishing between the biogeochemical processes affecting SVHC transport and persistence in ground water.

Furlong, E. T.; Koleis, J. C.; Aiken, G. R.

1997-01-01

183

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

184

Environmental assessment of aromatic hydrocarbons-contaminated sediments of the Mexican Salina Cuz Bay.  

PubMed

Concentrations of total aromatic hydrocarbons and extractable organic matter in the water column and sediment were determined in samples collected in the course of the last 20 years from the Salina Cruz Harbor, México, to assess the degree of organic contamination. In sediments, organic compounds accumulate in shallow areas mostly associated with extractable organic matter and fine fractions. Calculated geocumulation index and enrichment factors suggest that contamination could be derived from anthropogenic activities attributed to harbor and ship scrapping activities, as well as transboundary source. Concentration of total aromatic hydrocarbons (as chrysene equivalents) ranged from 0.01 to 534 microg l(-1) in water, and from 0.10 to 2,160 microg g(-1) in sediments. Total aromatic concentration of 5 microg g(-1) is proposed as background concentration. PMID:17295107

González-Macías, C; Schifter, I; Lluch-Cota, D B; Méndez-Rodríguez, L; Hernández-Vázquez, S

2007-10-01

185

Use of fluorescence spectroscopy for monitoring petroleum hydrocarbon contamination in estuarine and ocean waters  

SciTech Connect

The aromatic hydrocarbon content of extracted water samples were estimated by fluorescence emission spectroscopy. Solutions were excited at 300 nm, the emission scanned from 310-500 nm and the fluorescence emission intensity of the main peaks measured and reported as equivalents of m-terphenyl (lambda/sub em/330 nm) and chrysene (lambda/sub em/ 380 nm). The fluorescence emission of the reagent impurities was measured as the blank. Results show that if fluorescence spectroscopy is to be used to monitor petroleum contamination of estuarine and seawaters, the fluorescence emission of extracts should be measured at least at two wavelenghts (330 nm; 380 nm) to allow the detection of fuel oil, lubricating oil and crude oil inputs. A preliminary clean up of extracts is not usually required, thus the measurement of the fluorescence emission of water extracts provides a rapid means of monitoring petroleum hydrocarbon contamination. (JMT)

Maher, W.A.

1983-04-01

186

Characterization and safety evaluation of the impact of hydrocarbon contaminants on ecological receptors.  

PubMed

Hydrocarbon-contaminant removal efficiency of Bambara groundnuts and biomagnification was investigated. The crude oil contaminated soil samples in which the plants were established were either un-amended, or amended with NPK, or Urea, or Poultry manure. Amendments improved phytoextraction rates as follows: Urea - 63.37%, NPK - 65.99%, Poultry - manure - 70.04%, for PAH; Urea - 78.80%, NPK - 79.80%, Poultry manure - 87.90%, for BTEX. Hazard characterization from 28-day feeding study revealed negative effects of potentially toxic BTEX and PAH on organ weight, optimum digestibility and animal growth rate. Sleep time decreased with increasing hydrocarbon concentrations probably due to increased liver enzyme activity. PMID:20623265

Nwaichi, Eucharia O; Onyeike, Eugene N; Wegwu, Matthew O

2010-08-01

187

Contamination of soils in the urbanized areas of Belarus with polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

The content of polycyclic aromatic hydrocarbons (PAHs) in the soils of urbanized areas, including the impact zones of Belarus, were studied. The concentrations of 16 PAHs in the soils were determined for individual and high-rise building zones, forests, and forest parks of Belarus. The levels of the PAH accumulation in the soils of different industrial enterprises and boiler stations were analyzed. Possible sources of soil contamination with PAHs were considered, and the structure of the PAHs in the soils was shown. The levels of the soil contamination were determined from the regulated parameters for individual compounds and the sum of 16 PAHs.

Kukharchyk, T. I.; Khomich, V. S.; Kakareka, S. V.; Kurman, P. V.; Kozyrenko, M. I.

2013-02-01

188

Mechanical Alteration And Contamination Issues In Automated Subsurface Sample Acquisition And Handling  

NASA Astrophysics Data System (ADS)

The Drilling Automation for Mars Exploration (DAME) project's purpose is to develop and field-test drilling automation and robotics technologies for projected use in missions in the 2011-15 period. DAME includes control of the drilling hardware, and state estimation of both the hardware and the lithography being drilled and the state of the hole. A sister drill was constructed for the Mars Analog Río Tinto Experiment (MARTE) project and demonstrated automated core handling and string changeout in 2005 drilling tests at Rio Tinto, Spain. DAME focused instead on the problem of drill control while actively drilling while not getting stuck. Together, the DAME and MARTE projects demonstrate a fully automated robotic drilling capability, including hands-off drilling, adjustment to different strata and downhole conditions, recovery from drilling faults (binding, choking, etc.), drill string changeouts, core acquisition and removal, and sample handling and conveyance to in-situ instruments. The 2006 top-level goal of DAME drilling in-situ tests was to verify and demonstrate a capability for hands-off automated drilling, at an Arctic Mars-analog site. There were three sets of 2006 test goals, all of which were exceeded during the July 2006 field season. The first was to demonstrate the recognition, while drilling, of at least three of the six known major fault modes for the DAME planetary-prototype drill, and to employ the correct recovery or safing procedure in response. The second set of 2006 goals was to operate for three or more hours autonomously, hands-off. And the third 2006 goal was to exceed 3m depth into the frozen breccia and permafrost with the DAME drill (it had not gone further than 2.2m previously). Five of six faults were detected and corrected, there were 43 hours of hands-off drilling (including a 4 hour sequence with no human presence nearby), and 3.2m was the total depth. And ground truth drilling used small commercial drilling equipment in parallel in order to obtain cores and ice profiles at the drilling site. In the course of DAME drilling automation testing, the drilling-induced temperature gradients and their effects on encountered subsurface permafrost and ice layers were observed while drilling in frozen impact breccia at Haughton Crater. In repeated tests of robotic core removal processing and handling in the MARTE project, including field tests, cross-contamination issues arose between successive cores and samples, and procedures and metrics were developed for minimizing the cross-contamination. The MARTE core processing cross-contamination aspects were tested by analyzing a set of pristine samples (those stratigraphically known) vs. cuttings (loose clays) or artifacts from the robotic drilling (indurated clay layers). MARTE ground truth drilling, in parallel with the automated tests, provided control information on the discontinuity/continuity of the stratigraphic record (i.e., texture, color and structure of loose and consolidated materials).

Glass, B. J.; Cannon, H.; Bonaccorsi, R.; Zacny, K.

2006-12-01

189

Identification of the key factors affecting composting of a weathered hydrocarbon-contaminated soil  

Microsoft Academic Search

The effects of the C\\/N ratio, CaCO3 and PO4 addition, and temperature profile on reactor-based composting of weathered hydrocarbon-contaminated soil were evaluated in a series of 30-day tests in temperature-controlled mini-composters. Soil containing 17,000 mg (kg dry soil)-1 mineral oil and grease (MOG) was composted with maple leaves and alfalfa. Although the leaves and alfalfa also contained MOG, degradation of

N. Beaudin; R. F. Caron; R. Legros; J. Ramsay; B. Ramsay

1999-01-01

190

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

Microsoft Academic Search

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

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

2005-01-01

191

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

192

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

Microsoft Academic Search

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

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

2003-01-01

193

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

Microsoft Academic Search

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 ¹⁴C-PAH substrates incubated in sediment slurries. Mineralization rate constants and substrate turnover times were

Sherrill

1982-01-01

194

TOXICOKINETICS OF POLYCYCLIC AROMATIC HYDROCARBONS FROM CONTAMINATED SEDIMENT BY THE AMPHIBIAN LARVAE (PLEURODELES WALTL)  

Microsoft Academic Search

The newt larvae (Pleurodeles waltl) stage 48–49 in the development table of Gallien and Durocher (1) were exposed for 30 days to sediment previously contaminated with individual C-labeled polycyclic aromatic hydrocarbons (PAHs), including anthracene (Ant), phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP). Toxicokinetic parameters (uptake and depuration rate constants) were measured. The rate of radioactivity release was measured under both

P. Garrigues; J. E. Djomo; V. Ferrier; A. Dauta; A. Monkiedje; A. Mvondo Ze; J. F. Narbonne

2004-01-01

195

Removal of petroleum hydrocarbons from contaminated groundwater using an electrocoagulation process: Batch and continuous experiments  

Microsoft Academic Search

The efficacy of an electrocoagulation process (ECP) was evaluated for the treatment of petroleum-contaminated groundwater and quantified as the total petroleum hydrocarbon (TPH) removed. Various operating variables were examined for their effects on TPH removal; these variables included electrode materials (aluminum, iron, and steel), water pH (4 to 11), current density (2 to 18mA\\/cm2), reaction time (2 to 60min), aeration,

Gholamreza Moussavi; Rasoul Khosravi; Mahdi Farzadkia

2011-01-01

196

Pyrosequence Analysis of Unamplified and Whole Genome Amplified DNA from Hydrocarbon-Contaminated Groundwater  

Microsoft Academic Search

Pyrosequence data was used to analyze the composition and metabolic potential of a metagenome from a hydrocarbon-contaminated\\u000a site. Unamplified and whole genome amplified (WGA) sequence data was compared from this source. According to MG-RAST, an additional\\u000a 2,742,252 bp of DNA was obtained with the WGA, indicating that WGA has the ability to generate a large amount of DNA from\\u000a a

Nathlee S. Abbai; Algasan Govender; Rehana Shaik; Balakrishna Pillay

197

Studying contaminant transport and chem ical reduction in subsurface sediment by modeling flow in porous media  

Microsoft Academic Search

This paper presents imaging and modeling aspects of an interdisciplinary study of subsurface pollution and environmental remediation. F18 — FDG PET and Tc99m — NaTcO4 SPECT studie s were performed to follow dynamic changes in the radiotracer distribution in model systems. Radioisotope solution was pumped through the test columns filled with sand or sediment in order to reproduce subsurface conditions

Rostyslav Boutchko; Vitaliy Rayz; James O'Neil; Nicholas T. Vandehey; Peter S. Nico; Jennifer Druhan; Thomas F. Budinger; David Saloner; Grant T. Gullberg; William W. Moses

2010-01-01

198

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...

199

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...

200

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

EPA Science Inventory

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

201

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

EPA Science Inventory

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

202

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

Microsoft Academic Search

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

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

2010-01-01

203

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

204

Hydrocarbon contamination and plant species determine the phylogenetic and functional diversity of endophytic degrading bacteria.  

PubMed

Salt marsh sediments are sinks for various anthropogenic contaminants, giving rise to significant environmental concern. The process of salt marsh plant survival in such environment is very intriguing and at the same time poorly understood. The plant–microbe interactions may play a key role in the process of environment and in planta detoxification.In this study, a combination of culture-dependent and culture-independent molecular approaches [enrichment cultures, polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), DNA sequencing] were used to investigate the effect of petroleum hydrocarbons (PH) contamination on the structure and function[polycyclic aromatic hydrocarbon (PAH) dioxygenase genes] of endophytic bacterial communities of salt marsh plant species (Halimione portulacoides and Sarcocornia perennis)in the estuarine system Ria de Aveiro (Portugal). Pseudomonads dominated the cultivable fraction of the endophytic communities in the enrichment cultures. In a set of fifty isolates tested, nine were positive for genes encoding for PAH dioxygenases (nahAc)and four were positive for plasmid carrying genes encoding PAH degradation enzymes(nahAc). Interestingly, these plasmids were only detected in isolates from most severely PH-polluted sites. The results revealed site-specific effects on endophytic communities,related to the level of PH contamination in the sediment, and plant-species-specific ‘imprints’ in community structure and in genes encoding for PAH dioxygenases. These results suggest a potential ecological role of bacterial plant symbiosis in the process of plant colonization in urban estuarine areas exposed to PH contamination. PMID:24765659

Oliveira, Vanessa; Gomes, Newton C M; Almeida, Adelaide; Silva, Artur M S; Simões, Mário M Q; Smalla, Kornelia; Cunha, Ângela

2014-03-01

205

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

PubMed

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

Uhmann, Amandine; Aspray, Thomas J

2012-06-15

206

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

207

Hydrochemical and Isotopic Evidence of Natural Attenuation at the Gas Station Contaminated with Fuel Hydrocarbon  

NASA Astrophysics Data System (ADS)

Groundwater flow, hydrochemistry and the carbon isotope composition (d13C) of dissolved inorganic carbon (DIC) were measured to know the effect of natural attenuation which is induced by biodegradation of petroleum hydrocarbon at the abandoned gas station contaminated fuel hydrocarbons. The aquifer sediment consists of 4 to 5 m of unconsolidated and weathered soils overlying granite. The monitoring results of water level showed the immediate response of that to rainfall. This implies that the site is an unconfined aquifer or is located at the near of groundwater recharge area. The contaminant transport modeling using GMS showed that the contaminants, BTEX, transported to two main directions, south and southwest from UST and pipeline. These results were proved by the filed observation of the BTEX from the groundwater seepage at the streams of south and southwest area. The geochemical indicator of natural attenuation, red iron precipitate, was also observed at the groundwater seepage. The hydrochemical indicators, Fe(II), Mn(II), sufides, and methane, of terminal electron accepting processes represented the sulfate reducing and methanogenesis environment of the site. d13C values of DIC ranged from -20.2 to -9.3 permil and increased in the source zone by the microbial degradation of hydrocarbon under methanogenic condition. The enrichment of isotopically heavy C is caused by the production of light 12CH4 from microbial respiration. The molar ratio of Ca to HCO3 is about 2.5 and this indicates the contribution of microbial oxidation of fuel hydrocarbon to DIC in groundwater. The geochemical modeling using PHREEQC showed the oversaturation of siderite, rhodocrosite and goethite and the saturation index of calcite increased as the increase of bicarbonate, indicating the enhanced microbial degradation. From the research results, the mineralogical, hydrological and microbiological factors can exert influence on groundwater chemistry and d13C of DIC.

Ko, K.; Oh, I.; Suk, H.; Lee, K.

2005-12-01

208

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

PubMed

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

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

2004-09-01

209

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

210

Rapid evolution of redox processes in a petroleum hydrocarbon-contaminated aquifer  

USGS Publications Warehouse

Ground water chemistry data collected over a six-year period show that the distribution of contaminants and redox processes in a shallow petroleum hydrocarbon-contaminated aquifer has changed rapidly over time. Shortly after a gasoline release occurred in 1990, high concentrations of benzene were present near the contaminant source area. In this contaminated zone, dissolved oxygen in ground water was depleted, and by 1994 Fe(III) reduction and sulfate reduction were the predominant terminal electron accepting processes. Significantly, dissolved methane was below measurable levels in 1994, indicating the absence of significant methanogenesis. By 1996, however, depletion of solid-phase Fe(III)-oxyhydroxides in aquifer sediments and depletion of dissolved sulfate in ground water resulted in the onset of methanogenesis. Between 1996 and 2000, water-chemistry data indicated that methanogenic metabolism became increasingly prevalent. Molecular analysis of 16S-rDNA extracted from sediments shows the presence of a more diverse methanogenic community inside as opposed to outside the plume core, and is consistent with water-chemistry data indicating a shift toward methanogenesis over time. This rapid evolution of redox processes reflects several factors including the large amounts of contaminants, relatively rapid ground water flow (???0.3 m/day [???1 foot/day]), and low concentrations of microbially reducible Fe(III) oxyhydroxides (???1 ??mol/g) initially present in aquifer sediments. These results illustrate that, under certain hydrologic conditions, redox conditions in petroleum hydrocarbon-contaminated aquifers can change rapidly in time and space, and that the availability of solid-phase Fe(III)-oxyhydroxides affects this rate of change.

Chapelle, F. H.; Bradley, P. M.; Lovley, D. R.; O'Neill, K.; Landmeyer, J. E.

2002-01-01

211

Detection and remediation of soil and aquifer systems contaminated with petroleum products: an overview  

Microsoft Academic Search

Fate of organic chemicals in the subsurface strata is not very well understood. It has only been a decade or two that environmental scientists are focusing their attentions on remediating sites that are contaminated with organic chemicals. Different routes of soil and groundwater contamination by petroleum hydrocarbon compounds and their partitioning into gaseous, aqueous and pure phases in the subsurface

Farhad Nadim; George E Hoag; Shili Liu; Robert J Carley; Peter Zack

2000-01-01

212

Humic acids enhanced removal of aromatic hydrocarbons from contaminated aquifers: developing a sustainable technology.  

PubMed

Contamination by gasoline and diesel fuels is a threat to groundwater resources. Polynuclear aromatic hydrocarbons (PAHs) which can represent up to 60% of volume in diesel fuels are of particular concern because many of them are carcinogenic and they are persistent, especially in oxygen-limited environment. Despite the development of alternative approaches, pump and treat continues to be the leading technology for the remediation of groundwater contaminated by gasoline and diesel fuels. The efficiency of this technology is however limited by the low solubility of the aromatic hydrocarbons. The objective of this study was to investigate the influence of humic acids on the removal of aromatic hydrocarbons from petroleum products in groundwater aquifers and to evaluate the potential use of humic acids, as a cost effective additive, in groundwater and soil remediation. In order to prove the feasibility of using humic acid in the field, a pilot scale experiment was conducted in a model aquifer with a very dense monitoring network, providing controlled conditions only possible in a semi-artificial system. In addition, different sources of humic acids were compared with surfactants for their ability to bind PAHs. PMID:11597111

Lesage, S; Brown, S; Millar, K; Novakowski, K

2001-09-01

213

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

214

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...

215

Geology and Geohydrology at CRREL, Hanover, New Hampshire: Relationship to Subsurface Contamination.  

National Technical Information Service (NTIS)

Trichloroethylene (TCE) was discovered in three of the industrial wells at CRREL, as well as in two domestic wells in bedrock across the river. This report describes the geohydrology of the CRREL vicinity and the subsurface behavior of TCE as part of the ...

S. A. Shoop L. W. Gatto

1992-01-01

216

VALOR code version 1. 0: A PC code for simulating immiscible contaminant transport in subsurface systems  

Microsoft Academic Search

A two-dimensional numerical model for immiscible multiphase fluid flow in subsurface systems was developed. The model is entitled Vertical and Lateral Organic Redistribution (VALOR). VALOR is capable of simulating the vertical and lateral simultaneous migration of water, air, and nonaqueous phase liquids (NAPLs) in heterogeneous soils with horizontally aligned geologic strata. It can be used to investigate the lateral migration

L. M. Abriola; K. Rathfelder; M. Maiza; S. Yadav

1992-01-01

217

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

PubMed

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

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

2012-02-01

218

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

SciTech Connect

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

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

2002-06-01

219

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

EPA Science Inventory

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

220

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

221

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

SciTech Connect

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

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

2009-07-01

222

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

223

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

PubMed Central

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.

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

2009-01-01

224

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

Microsoft Academic Search

Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons\\u000a (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous\\u000a (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified\\u000a PAHs, including high-molecular-weight compounds, were removed to a

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

225

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...

226

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...

227

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

228

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

229

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

Microsoft Academic Search

Natural attenuation processes are commonly used for remediation of contaminated sites. A variety of natural processes occur without human intervention at all sites to varying rates and degrees of effectiveness to attenuate (decrease) the mass, toxicity, mobility, volume, or concentration of organic and inorganic contaminants in soil, groundwater, and surface water systems. The objective of this review is to identify

Kenneth M. Krupka; Wayne J. Martin

2001-01-01

230

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

NASA Astrophysics Data System (ADS)

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

Papapetridis, K.; Paleologos, E.

2012-04-01

231

Application of data fusion in human health risk assessment for hydrocarbon mixtures on contaminated sites.  

PubMed

The exposure and toxicological data used in human health risk assessment are obtained from diverse and heterogeneous sources. Complex mixtures found on contaminated sites can pose a significant challenge to effectively assess the toxicity potential of the combined chemical exposure and to manage the associated risks. A data fusion framework has been proposed to integrate data from disparate sources to estimate potential risk for various public health issues. To demonstrate the effectiveness of the proposed data fusion framework, an illustrative example for a hydrocarbon mixture is presented. The Joint Directors of Laboratories Data Fusion architecture was selected as the data fusion architecture and Dempster-Shafer Theory (DST) was chosen as the technique for data fusion. For neurotoxicity response analysis, neurotoxic metabolites toxicological data were fused with predictive toxicological data and then probability-boxes (p-boxes) were developed to represent the toxicity of each compound. The neurotoxic response was given a rating of "low", "medium" or "high". These responses were then weighted by the percent composition in the illustrative F1 hydrocarbon mixture. The resulting p-boxes were fused according to DST's mixture rule of combination. The fused p-boxes were fused again with toxicity data for n-hexane. The case study for F1 hydrocarbons illustrates how data fusion can help in the assessment of the health effects for complex mixtures with limited available data. PMID:23219588

Dyck, Roberta; Islam, M Shafiqul; Zargar, Amin; Mohapatra, Asish; Sadiq, Rehan

2013-11-16

232

Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil.  

PubMed

The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology. PMID:18333672

Lemieux, Christine L; Lambert, Iain B; Lundstedt, Staffan; Tysklind, Mats; White, Paul A

2008-04-01

233

Ex situ treatment of hydrocarbon-contaminated soil using biosurfactants from Lactobacillus pentosus.  

PubMed

The utilization of biosurfactants for the bioremediation of contaminated soil is not yet well established, because of the high production cost of biosurfactants. Consequently, it is interesting to look for new biosurfactants that can be produced at a large scale, and it can be employed for the bioremediation of contaminated sites. In this work, biosurfactants from Lactobacillus pentosus growing in hemicellulosic sugars solutions, with a similar composition of sugars found in trimming vine shoot hydrolysates, were employed in the bioremediation of soil contaminated with octane. It was observed that the presence of biosurfactant from L. pentosus accelerated the biodegradation of octane in soil. After 15 days of treatment, biosurfactants from L. pentosus reduced the concentration of octane in the soil to 58.6 and 62.8%, for soil charged with 700 and 70,000 mg/kg of hydrocarbon, respectively, whereas after 30 days of treatment, 76% of octane in soil was biodegraded in both cases. In the absence of biosurfactant and after 15 days of incubation, only 1.2 and 24% of octane was biodegraded in soil charged with 700 and 70,000 mg/kg of octane, respectively. Thus, the use of biosurfactants from L. pentosus, as part of a well-designed bioremediation process, can provide mechanisms to mobilize the target contaminants from the soil surface to make them more available to the microbial population. PMID:21797277

Moldes, Ana Belén; Paradelo, Remigio; Rubinos, David; Devesa-Rey, Rosa; Cruz, José Manuel; Barral, María Teresa

2011-09-14

234

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

PubMed

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

Xu, Ran; Obbard, Jeffrey P

2004-01-01

235

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

236

VALOR code version 1. 0: A PC code for simulating immiscible contaminant transport in subsurface systems  

SciTech Connect

A two-dimensional numerical model for immiscible multiphase fluid flow in subsurface systems was developed. The model is entitled Vertical and Lateral Organic Redistribution (VALOR). VALOR is capable of simulating the vertical and lateral simultaneous migration of water, air, and nonaqueous phase liquids (NAPLs) in heterogeneous soils with horizontally aligned geologic strata. It can be used to investigate the lateral migration of light organic liquids (SG < 1) across the water table, as well as the downward percolation of dense organic liquids (SG > 1) through the saturated zone. Optional features allow for transport over a sloping water table. The model is primarily intended as a planning tool for site assessment and permitting studies.

Abriola, L.M.; Rathfelder, K.; Maiza, M.; Yadav, S. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering)

1992-09-01

237

A Cyclic Approach for the Qunatification and Remediation of Subsurface Contamination  

NASA Astrophysics Data System (ADS)

A new approach to contaminated land assessment and revitalisation, focusing on groundwater quality and complex contamination patterns at urban industrial megasites was developed. The new approach comprises three cycles: (a) the assessment of groundwater contamination using an integral mass flux based investigation method at the scale of entire industrial sites, (b) the delimiting of potential contamination source zones using backtracking and contaminant fingerprinting techniques, and (c) the development of emission oriented remediation strategies. The major advantage of the new approach is that the number of areas to be considered for further investigation and remediation is reduced from one cycle to the next. Consequently, a large potentially contaminated area is screened initially, but only a small area may be finally remediated, yielding a significant reduction of costs. The results from the integral investigation at the scale of entire megasites can be used for risk assessment purposes, for the quantification of the natural attenuation potential, as well as for the development of priorities for clean-up and / or further investigations and for the design of remediation measures. In addition, a consistent quantification of uncertainties in the results from the application of the integral groundwater investigation method is possible. Finally, the delimiting of the source zone extent and its uncertainty allows to define priorities for further investigation measures at a smaller scale, and to develop cost-optimized clean-up strategies. In this contribution, the focus will be on the three cycles of the new approach. Also, examples of application will be presented.

Ptak, T.; Teutsch, G.

2004-12-01

238

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

239

Comparison of indigenous and exogenous microbial populations during slurry phase biodegradation of long-term hydrocarbon-contaminated soil.  

PubMed

In this study, a number of slurry-phase strategies were trialled over a 42 day period in order to determine the efficacy of bioremediation for long-term hydrocarbon-contaminated soil (145 g kg(-1) C(10)-C(40)). The addition of activated sludge and nutrients to slurries (bioaugmentation) resulted in enhanced hydrocarbon removal (51.6 ± 8.5 %) compared to treatments receiving only nutrients (enhanced natural attenuation [ENA]; 41.3 ± 6.4 %) or no amendments (natural attenuation; no significant hydrocarbon removal, P < 0.01). This data suggests that the microbial community in the activated sludge inoculum contributed to the enhanced removal of hydrocarbons in ENA slurries. Microbial diversity in slurries was monitored using DGGE with dominant bands excised and sequenced for identification. Applying the different bioremediation strategies resulted in the formation of four distinct community clusters associated with the activated sludge (inoculum), bioaugmentation strategy at day 0, bioaugmentation strategy at weeks 2-6 and slurries with autoclaved sludge and nutrient additions (bioaugmentation negative control). While hydrocarbon-degrading bacteria genera (e.g. Aquabacterium and Haliscomenobacter) were associated with the hydrocarbon-contaminated soil, bioaugmentation of soil slurries with activated sludge resulted in the introduction of bacteria associated with hydrocarbon degradation (Burkholderiales order and Klebsiella genera) which presumably contributed to the enhanced efficacy for this slurry strategy. PMID:22684213

Aburto-Medina, Arturo; Adetutu, Eric M; Aleer, Sam; Weber, John; Patil, Sayali S; Sheppard, Petra J; Ball, Andrew S; Juhasz, Albert L

2012-11-01

240

Influence of soil and hydrocarbon properties on the solvent extraction of high-concentration weathered petroleum from contaminated soils.  

PubMed

Petroleum ether was used to extract petroleum hydrocarbons from soils collected from six oil fields with different history of exploratory and contamination. It was capable of fast removing 76-94 % of the total petroleum hydrocarbons including 25 alkanes (C11-C35) and 16 US EPA priority polycyclic aromatic hydrocarbons from soils at room temperature. The partial least squares analysis indicated that the solvent extraction efficiencies were positively correlated with soil organic matter, cation exchange capacity, moisture, pH, and sand content of soils, while negative effects were observed in the properties reflecting the molecular size (e.g., molecular weight and number of carbon atoms) and hydrophobicity (e.g., water solubility, octanol-water partition coefficient, soil organic carbon partition coefficient) of hydrocarbons. The high concentration of weathered crude oil at the order of 10(5) mg kg(-1) in this study was demonstrated adverse for solvent extraction by providing an obvious nonaqueous phase liquid phase for hydrocarbon sinking and increasing the sequestration of soluble hydrocarbons in the insoluble oil fractions during weathering. A full picture of the mass distribution and transport mechanism of petroleum contaminants in soils will ultimately require a variety of studies to gain insights into the dynamic interactions between environmental indicator hydrocarbons and their host oil matrix. PMID:24442962

Sui, Hong; Hua, Zhengtao; Li, Xingang; Li, Hong; Wu, Guozhong

2014-05-01

241

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

PubMed Central

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

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

2006-01-01

242

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

SciTech Connect

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

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

2006-01-01

243

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

SciTech Connect

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

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

2006-09-30

244

Dynamics of carbon, nitrogen and hydrocarbons in diesel-contaminated soil amended with biosolids and maize.  

PubMed

Contamination of soil with hydrocarbons occurs frequently when petroleum ducts are damaged. Restoration of those contaminated soils might be achieved by applying readily available organic material. An uncontaminated clayey soil sampled in the vicinity of a duct carrying diesel which ruptured recently, was contaminated in the laboratory and amended with or without maize or biosolids while production of carbon dioxide (CO(2)), dynamics of ammonia (NH(4)(+)), nitrates (NO(3)(-)), and total petroleum hydrocarbons (TPH) were monitored. The fastest mineralization of diesel, as witnessed by production of CO(2), was found when biosolids were added, but the amount mineralized after 100 days, approximately 88%, was similar in all treatments. Approximately 5 mg of the 48 mg TPH kg(-1) found in the sterilized soil at the beginning of the experiment could not be accounted for after 100 days. The concentration of TPH in the unsterilized soil decreased rapidly in all treatments, but the rate of decrease was different between the treatments. The fastest decrease was found in the soil amended with biosolids and approximately 30 mg TPH kg(-1) or 60% could not be accounted for within 7 days. The decrease in concentration of TPH at the onset of the incubation was similar in the other treatments. After 100 days, the concentration of TPH was similar in all soils and appear to stabilize at 19 mg TPH kg(-1) soil. It was concluded that biosolids accelerated the decomposition of diesel and TPH due to its large nutrient content, but after 100 days the amount of diesel mineralized and the residual concentration of TPH was not affected by the treatment applied. PMID:14575750

Rivera-Espinoza, Y; Dendooven, L

2004-01-01

245

Leaching of human pathogens in repacked soil lysimeters and contamination of potato tubers under subsurface drip irrigation in Denmark.  

PubMed

The risk for contamination of potatoes and groundwater through subsurface drip irrigation with low quality water was explored in 30 large-scale lysimeters containing repacked coarse sand and sandy loam soils. The human pathogens, Salmonella Senftenberg, Campylobacter jejuni and Escherichia coli O157:H7, and the virus indicator Salmonella Typhimurium bacteriophage 28B, were added weekly through irrigation tubes for one month with low irrigation rates (8 mm per week). In the following six months lysimeters were irrigated with groundwater free of pathogens. Two weeks after irrigation was started, phage 28B was detected in low concentrations (2 pfu ml(-1)) in leachate from both sandy loam soil and coarse sand lysimeters. After 27 days, phage 28B continued to be present in similar concentrations in leachate from lysimeters containing coarse sand, while no phage were found in lysimeters with sandy loam soil. The added bacterial pathogens were not found in any leachate samples during the entire study period of 212 days. Under the study conditions with repacked soil, limited macropores and low water velocity, bacterial pathogens seemed to be retained in the soil matrix and died-off before leaching to groundwater. However, viruses may leach to groundwater and represent a health risk as for some viruses only few virus particles are needed to cause human disease. The bacterial pathogens and the phage 28B were found on the potato samples harvested just after the application of microbial tracers was terminated. The findings of bacterial pathogens and phage 28 on all potato samples suggest that the main risk associated with subsurface drip irrigation with low quality water is faecal contamination of root crops, in particular those consumed raw. PMID:21762945

Forslund, Anita; Plauborg, Finn; Andersen, Mathias Neumann; Markussen, Bo; Dalsgaard, Anders

2011-10-01

246

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

SciTech Connect

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

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

1982-08-01

247

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

248

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

249

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

SciTech Connect

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

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

1995-05-01

250

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

251

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 ...

252

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...

253

Organochlorine, organophosphoric and organotin contaminants, aromatic and aliphatic hydrocarbons and heavy metals in sediments of the ports from Polish part of the Vistula Lagoon (Baltic Sea)  

Microsoft Academic Search

The concentrations of: polycyclic aromatic and petroleum hydrocarbons, polychlorinated biphenyls, dioxins, organochlorine and organophosphoric pesticides, tributyltin and metals were determined in sediments of approach fairways to the main ports in the Polish part of the Vistula Lagoon and of the Elbl?g River. Analysed sediments contained low concentrations of all contaminants, except petroleum hydrocarbons. The average petroleum hydrocarbons (PHCs) concentration was

Marta Staniszewska; Helena Boniecka; Anna Gajecka

2012-01-01

254

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

PubMed

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 (alphaC) of 1.0015 and 1.0011, respectively. When the extent of biodegradation in the soil column was calculated based on the measured isotope ratios (R(t)) and an isotope fractionation factor (alphaC=1.0017) obtained from a sulfate-reducing batch culture the theoretical residual substrate concentrations (C(t)) 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 (delta13C) was observed for the residual non-degraded toluene (7.2 per thousand ), o-xylene (8.1 per thousand ) and naphthalene fractions (1.2 per thousand ). 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. PMID:12855203

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

2003-08-01

255

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

256

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

SciTech Connect

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

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

2006-09-21

257

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

PubMed

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

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

2012-10-01

258

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

259

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

260

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

PubMed Central

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

Aelion, C M; Bradley, P M

1991-01-01

261

Anaerobic oxidation of crude oil hydrocarbons by the resident microorganisms of a contaminated anoxic aquifer.  

PubMed

The biodegradation of two crude oils by microorganisms from an anoxic aquifer previously contaminated by natural gas condensate was examined under methanogenic and sulfate-reducing conditions. Artificially weathered Alaska North Slope crude oil greatly stimulated both methanogenesis and sulfate reduction. Gas chromatographic analysis revealed the entire n-alkane fraction of this oil (C13-C34) was consumed under both conditions. Naphthalene, 2-methylnaphthalene, and 2-ethylnaphthalene were also biodegraded but only in the presence of sulfate. Alba crude oil, which is naturally depleted in n-alkanes, resulted in a relatively modest stimulation of methanogenesis and sulfate reduction. Polycyclic aromatic hydrocarbon biodegradation was similar to that found for the Alaska North Slope crude oil, but a broader range of compounds was metabolized, including 2,6-dimethylnaphthalene and 2,7-dimethylnaphthalene in the presence of sulfate. These results indicate that n-alkanes are relatively labile, and their biodegradation in terrestrial environments is not necessarily limited by electron acceptor availability. Polycyclic aromatic hydrocarbons are relatively more recalcitrant, and the biodegradation of these substrates appeared to be sulfate-dependent and homologue-specific. This information should be useful for assessing the limits of in situ crude oil biodegradation in terrestrial environments and for making decisions regarding risk-based corrective actions. PMID:14655710

Townsend, G Todd; Prince, Roger C; Suflita, Joseph M

2003-11-15

262

Enhanced bioremediation of hydrocarbon-contaminated soil using pilot-scale bioelectrochemical systems.  

PubMed

Two column-type bioelectrochemical system (BES) modules were installed into a 50-L pilot scale reactor packed with diesel-contaminated soils to investigate the enhancement of passive biodegradation of petroleum compounds. By using low cost electrodes such as biochar and graphite granule as non-exhaustible solid-state electron acceptors, the results show that 82.1-89.7% of the total petroleum hydrocarbon (TPH) was degraded after 120 days across 1-34cm radius of influence (ROI) from the modules. This represents a maximum of 241% increase of biodegradation compared to a baseline control reactor. The current production in the BESs correlated with the TPH removal, reaching the maximum output of 70.4±0.2mA/m(2). The maximum ROI of the BES, deducting influence from the baseline natural attenuation, was estimated to be more than 90cm beyond the edge of the reactor (34cm), and exceed 300cm should a non-degradation baseline be used. The ratio of the projected ROI to the radius of BES (ROB) module was 11-12. The results suggest that this BES can serve as an innovative and sustainable technology for enhanced in situ bioremediation of petroleum hydrocarbons in large field scale, with additional benefits of electricity production and being integrated into existing field infrastructures. PMID:24762696

Lu, Lu; Yazdi, Hadi; Jin, Song; Zuo, Yi; Fallgren, Paul H; Ren, Zhiyong Jason

2014-06-15

263

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

PubMed

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

Steliga, Teresa; Jakubowicz, Piotr; Kapusta, Piotr

2012-12-01

264

Petroleum hydrocarbon contamination in boreal forest soils: a mycorrhizal ecosystems perspective.  

PubMed

The importance of developing multi-disciplinary approaches to solving problems relating to anthropogenic pollution is now clearly appreciated by the scientific community, and this is especially evident in boreal ecosystems exposed to escalating threats of petroleum hydrocarbon (PHC) contamination through expanded natural resource extraction activities. This review aims to synthesize information regarding the fate and behaviour of PHCs in boreal forest soils in both ecological and sustainable management contexts. From this, we hope to evaluate potential management strategies, identify gaps in knowledge and guide future research. Our central premise is that mycorrhizal systems, the ubiquitous root symbiotic fungi and associated food-web communities, occupy the structural and functional interface between decomposition and primary production in northern forest ecosystems (i.e. underpin survival and productivity of the ecosystem as a whole), and, as such, are an appropriate focal point for such a synthesis. We provide pertinent basic information about mycorrhizas, followed by insights into the ecology of ecto- and ericoid mycorrhizal systems. Next, we review the fate and behaviour of PHCs in forest soils, with an emphasis on interactions with mycorrhizal fungi and associated bacteria. Finally, we summarize implications for ecosystem management. Although we have gained tremendous insights into understanding linkages between ecosystem functions and the various aspects of mycorrhizal diversity, very little is known regarding rhizosphere communities in PHC-contaminated soils. This makes it difficult to translate ecological knowledge into environmental management strategies. Further research is required to determine which fungal symbionts are likely to survive and compete in various ecosystems, whether certain fungal - plant associations gain in ecological importance following contamination events, and how PHC contamination may interfere with processes of nutrient acquisition and exchange and metabolic processes. Research is also needed to assess whether the metabolic capacity for intrinsic decomposition exists in these ecosystems, taking into account ecological variables such as presence of other organisms (and their involvement in syntrophic biodegradation), bioavailability and toxicity of mixtures of PHCs, and physical changes to the soil environment. PMID:17437558

Robertson, Susan J; McGill, William B; Massicotte, Hugues B; Rutherford, P Michael

2007-05-01

265

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.

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

2004-01-01

266

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

Microsoft Academic Search

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

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

267

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

Microsoft Academic Search

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

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

2004-01-01

268

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

Microsoft Academic Search

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

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

2004-01-01

269

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

270

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

Microsoft Academic Search

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

Ran Xu; Jeffrey P. Obbard

271

Comparison of polycyclic aromatic hydrocarbon distributions and sedimentary organic matter characteristics in contaminated, coastal sediments from Pensacola Bay, Florida  

Microsoft Academic Search

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in a contaminated coastal area and the characteristics of the natural organic matter in tandem. We present a detailed study of PAH concentration, distribution, and organic matter characteristics of three core samples from Pensacola Bay, Florida. Solid-state 13C Nuclear Magnetic Resonance (NMR), pyrolysis gas chromatography coupled with mass

Myrna J. Simpson; Benny Chefetz; Ashish P. Deshmukh; Patrick G. Hatcher

2005-01-01

272

Impact of Bacterial Biomass on Contaminant Sorption and Transport in a Subsurface Soil †  

PubMed Central

The objective of this study was to investigate the impact of bacterial biomass on the sorption and transport of three solutes (quinoline, naphthalene, and 45Ca) in a subsurface soil. Miscible displacement techniques were employed to measure sorption and transport of the above compounds during steady, saturated water flow in sterile and/or bacterium-inoculated soil columns. The soil was inoculated with either a quinoline-degrading bacterium, Pseudomonas sp. 3N3A isolate, or its mutant isolate, B53, which does not degrade quinoline. In soil columns inoculated with the B53 and 3N3A isolates, quinoline sorption was reduced by about 60 and 20%, respectively. In contrast, 45Ca sorption was minimally reduced, which indicated that biomass did not significantly alter the cation-exchange capacity of the soil. Biomass impacts on sorption were solute specific, even when the sorption mechanism for both quinoline and 45Ca was similar. Thus, the differential response is attributed to biomass-induced changes in quinoline speciation; an increase in pH at the sorbent-water interface would result in a larger proportion of the neutral species and a decrease in sorption. Sorption of naphthalene was reduced by about 30%, which was attributed to accessibility of hydrophobic regions. Minimal biosorption of all solutes indicated negligible biofacilitated transport. Alteration of the soil surfaces upon addition of bacterial biomass reduced sorption of quinoline and naphthalene, thereby enhancing transport.

Bellin, C. A.; Rao, P. S. C.

1993-01-01

273

(The role of colloidal particles on the subsurface transport of contaminants)  

SciTech Connect

The primary purpose of this foreign travel was to attend the 10th meeting of the European Community's CoCo (colloids and complexation) Club to learn about research on groundwater colloids in Europe and inform the CoCo participants about the colloid subprogram of the US Department of Energy (DOE) Subsurface Science Program. The goal of CoCo Club research, and of the umbrella MIRAGE (MIgration of RAdionuclides in the GEosphere) Project, is to develop data and understanding necessary to complete safety assessments for licensing nuclear repositories in Europe. The emphasis of CoCo Club research is sorption of radionuclides to organic and inorganic colloidal particles. The traveler also visited the British Geological Survey (BGS) headquarters and a BGS field site. Discussions focused on development of innovative drilling equipment for minimizing aquifer disturbance, development and application of computerized resistivity tomography for aquifer characterization, and laboratory research on the role of organic matter on metal transport. The trip was successful in that the traveler obtained a comprehensive overview of European research on groundwater colloids which will help improve and focus DOE's colloid subprogram, and the traveler learned about advances in specific areas that will contribute to his own DOE-funded project.

McCarthy, J.F.

1990-02-22

274

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

275

Microbial community response to petroleum hydrocarbon contamination in the unsaturated zone at the experimental field site Vaerløse, Denmark.  

PubMed

This study investigates the influence of petroleum hydrocarbons on a microbial community in the vadose zone under field conditions. An artificial hydrocarbon mixture consisting of volatile and semi-volatile compounds similar to jet-fuel was emplaced in a previously uncontaminated vadose zone in nutrient-poor glacial melt water sand. The experiment included monitoring of microbial parameters and CO(2) concentrations in soil gas over 3 months in and outside the hydrocarbon vapor plume that formed around the buried petroleum. Microbial and chemical analyses of soil and vadose zone samples were performed on samples from cores drilled to 3.3 m depth on three dates and three lateral distances from the buried petroleum mass. Significantly elevated CO(2) concentrations were observed after contamination. Total cell numbers as determined by fluorescence microscopy were strongly correlated with soil organic carbon and nitrogen content but varied little with contamination. Redundancy analysis (RDA) allowed direct analysis of effects of selected environmental variables or the artificial contamination on microbiological parameters. Variation in biomass and CO(2) production was explained by soil parameters, to 46%, and by the duration of contamination, to 39.8%. The microbial community structure was assessed by community level physiological profiles (CLPP) analysis using Biolog(TM) Eco-Plates. In the CLPP data only 35.9% of the variation could be linked to soil parameters and contamination, however, the samples with greatest exposure to hydrocarbons grouped together on RDA plots. It is concluded that, at this nutrient-poor site, the microbial community was dominated by natural heterogeneity and that the influence of petroleum hydrocarbon vapors was weak. PMID:19712308

Kaufmann, Karin; Christophersen, Mette; Buttler, Alexandre; Harms, Hauke; Höhener, Patrick

2004-06-01

276

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 building at a site contaminated with gasoline. High VOC concentrations (30-60 g m{sup -3}) were measured in a soil gas 0.7 m below the building. Measured indoor air concentrations were nearly 10{sup 6} lower due to a sharp gradient in soil-gas VOC concentrations between 0.1 and 0.7 m ( a factor of nearly 10{sup 3}) and the dilution of soil gas entering the building by wind-driven building ventilation ( a factor of nearly 10{sup 3}). Measurements of soil physical and biological characteristics indicate that a partial physical barrier to vertical transport in combination with microbial degradation can explain the gradient. While these factors are likely to be important to varying degrees at other sites contaminated with VOC, we conclude that (1) the results of this study cannot be directly applied to estimate indoor air quality at other sites without the risk of incurring significant errors and instead that (2) future attempts to estimate VOC transport into building should be made with careful attention to the identification and separation of physical and biotic effects. 33 refs., 6 figs., 3 tabs.

Fischer, M.L.; Bentley, A.J.; Hodgson, A.T.; Sextro, R.G.; Daisey, J.M. [Lawrence Berkeley National Lab., CA (United States)] [Lawrence Berkeley National Lab., CA (United States); Dunkin, K.A. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); Nazaroff, W.W. [Lawrence Berkeley National Lab., CA (United States)] [Lawrence Berkeley National Lab., CA (United States); [Univ. of California, Berkeley, CA (United States)

1996-10-01

277

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

PubMed

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

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

2013-03-01

278

Contamination of polycyclic aromatic hydrocarbons (PAHs) in urban soils in Beijing, China.  

PubMed

Soil contamination with polycyclic aromatic hydrocarbons (PAHs) is an increasing problem in many countries, including China. An extensive and systematic survey has been undertaken to evaluate the contamination with PAHs of urban soils in Beijing, China. Soil samples were collected from campuses of universities, schools and kindergartens, public squares, fallow land and roadsides, and were analyzed for 16 PAHs by GC-MS. There was a high variability in the total PAHs (SigmaPAHs) concentrations, ranging from less than 366 to 27,825 ng g(-1). The highest SigmaPAHs concentrations were found at roadsides and industrial sites. Soil organic carbon (SOC) is one of the important factors that can influence the concentrations of PAHs in soils. It was found that concentrations of SigmaPAHs were significantly correlated with that of soil organic carbon. To trace the sources of PAHs, the ratios of phenanthrene to anthracene and fluoranthene to pyrene were used to identify pyrogenic and petrogenic sources, respectively. In most cases, PAHs in soils in urban areas of Beijing were pyrogenic. These sources included motor vehicle exhausts, industrial activities and coal burning. These data can be further used to assess the health risk associated with soils polluted with PAHs. PMID:15992927

Tang, Lily; Tang, Xiang-Yu; Zhu, Yong-Guan; Zheng, Ming-Hui; Miao, Qi-Long

2005-08-01

279

Surfactant-Enhanced Desorption and Biodegradation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil  

PubMed Central

We evaluated two nonionic surfactants, one hydrophobic (Brij 30) and one hydrophilic (C12E8), for their ability to enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil after it had been treated in an aerobic bioreactor. The effects of each surfactant were evaluated at doses corresponding to equilibrium aqueous-phase concentrations well above the surfactant’s critical micelle concentration (CMC), slightly above the CMC, and below the CMC. The concentrations of all 3- and 4-ring PAHs were significantly lower in the soil amended with Brij 30 at the two lower doses compared to controls, whereas removal of only the 3-ring PAHs was significantly enhanced at the highest Brij 30 dose. In contrast, C12E8 did not enhance PAH removal at any dose. In the absence of surfactant, <5% of any PAH desorbed from the soil over an 18-d period. Brij 30 addition at the lowest dose significantly increased the desorption of most PAHs, whereas the addition of C12E8 at the lowest dose actually decreased the desorption of all PAHs. These findings suggest that the effects of the two surfactants on PAH biodegradation could be explained by their effects on PAH bioavailability. Overall, this study demonstrates that the properties of the surfactant and its dose relative to the corresponding aqueous-phase concentration are important factors in designing systems for surfactant-enhanced bioremediation of PAH-contaminated soils in which PAH bioavailability is limited.

Zhu, Hongbo; Aitken, Michael D.

2010-01-01

280

Effects of rapeseed oil on the rhizodegradation of polyaromatic hydrocarbons in contaminated soil.  

PubMed

Plants have the ability to promote degradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil by supporting PAH degrading microorganisms in the rhizosphere (rhizodegradation). The aim of this study was to evaluate if rapeseed oil increases rhizodegradation because various studies have shown that vegetable oils are able to act as extractants for PAHs in contaminated soils and therefore might increase bioavailability of PAHs for microbial degradation. In this study different leguminous and grass species were tested. The results suggested a significant impact of vegetable oil (1 and 3% w/w) on plant growth (decrease of plant height and biomass). The results of the pot experiment showed a decrease in the PAH content of the soil without amendment of rapeseed oil after six months. In soil amended with 1% and 3% of oil, there was no decrease in PAH content within this period. Although no enhancement of PAH degradation by plants could be measured in the bulk soil of the pot experiments, a rhizobox experiment showed a significant reduction of PAH content in the rhizosphere of alfalfa (Medicago sativa cv. Europe). Our investigations also showed significant differences in the degradation behaviour of the 16 individually analysed PAHs. PMID:24933877

Gartler, Jorg; Wimmer, Bernhard; Soja, Gerhard; Reichenauer, Thomas G

2014-01-01

281

Bioavailability of polycyclic aromatic hydrocarbons from a historically contaminated sediment core  

SciTech Connect

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

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

1995-09-01

282

Subsurface Microbial Communities and Geochemistry Within a Vertical Transect of a Uranium-Contaminated Aquifer  

NASA Astrophysics Data System (ADS)

Microbial communities and geochemistry were analyzed within floodplain alluvia of the San Juan River, New Mexico, down-gradient of a uranium mill tailings disposal cell. A multi-level sampling device was used to investigate vertical variations in geochemistry and microbial community structure within the uranium contaminant plume within this shallow aquifer. Chemical analyses indicate that the interaction of uncontaminated artesian water and contaminant fluids has resulted in three geochemically-distinct regions. Similarity comparisons of bacterial community 16S rDNA fingerprints, based on T-RFLP analyses, show a grouping of microbial populations into three assemblages. These groupings correspond to the three geochemically-defined regions of the aquifer profile, indicating a relationship between community structure and geochemistry. Combined Bacterial 16S rDNA clone library and T-RFLP analyses show a predominance of organisms related to Nitrospira and Nitrosolobus, chemolithotrophic nitrite and ammonia oxidizers respectively, in the uncontaminated region of the aquifer profile. Within the plume-impacted area, organisms related to known nitrifying bacteria were not detected. Bacteria phylogenetically related to Acinetobacter, Aeromonas, Gallionella, Psuedomonas, and Thiomicrospira were identified in both the uncontaminated and plume regions. Within the contaminated region, sequences from organisms related to the metal oxidizing bacteria Leptothrix and Sphaerotilus were also found. 16S rDNA sequences with high similarity to Duganella zoogloeoides, a chemolithotrophic Mn-oxidizing bacterium known for uranyl complexation and sorption, were abundant in the clone library from the plume-impacted region. A diversity of organisms related to sulfate- and sulfur-reducing bacteria including Desulfobulbus, Desulfofrigus, Desulfosarcina, Desulfosporosinus, Desulfotomaculum, and Geobacter were present in the uncontaminated zone while less SRB diversity (Desulfobacter, Desulfobulbus, and Desulfonema) was observed in the plume region. T-RFLP results substantiate this trend, suggesting sulfate reducer populations shift from high diversity and low relative abundance to less diversity and a larger abundance over the transition from uncontaminated water into the plume region. These findings indicate that there is considerable biological potential for uranium immobilization at this site through reductive precipitation by sulfate or other metal reducing organisms or microbial uptake and sequestration. Given the diversity of microorganisms related to chemolithotrophic bacteria, growth by this mode of metabolism, and the biological oxidation of reduced metals, is also potentially an important process that may influence metal biogeochemistry at this site.

Gihring, T. M.; McKinley, J. P.; Fredrickson, J. K.; Long, P. E.

2002-12-01

283

Effects of climatic modalities on polycyclic aromatic hydrocarbons (PAHs) availability and attenuation in historically contaminated Technosol  

NASA Astrophysics Data System (ADS)

Since the decline of industrial activities in France, large areas of polycyclic aromatic hydrocarbon (PAHs)-contaminated soils have remained derelict. Thus, the fate of PAHs in such soils through natural attenuation process needs to be assessed. On the long-term scale (10-100 years), climate will greatly contribute to the evolution of soil physico-chemical properties and by consequences PAHs availability. In our study, we examined the effect of three contrasted climatic conditions (freeze-thawing, wetting-drying and high temperature) on soil aging processes of 11 historically contaminated soils and consequences on the availability of polycyclic aromatic compounds (including the 16 priority pollutants PAHs). Batch experiments were set-up for each modality; freeze-dried soil underwent variation of humidity and/or temperature. In a first step, PACs availability was roughly evaluated, with a water-extraction method using a H2O2 + CaCl2 solution. Dissolved organic carbon (DOC) content was measured in these extracts before and after applying the climatic modalities. Difference in DOC indicated an effect of the climatic modality on PACs availability. If an effect was noticed, available PACs was then accurately measured using (i) an hydrogen-peroxide oxidation on the soils followed (ii) a dichloromethane (DCM) extraction and a Gas Chromatography - Mass Spectrometer (GC-MS) quantification of the remaining PACs (i.e. unavailable). Variation of PACs availability will greatly help to understand the mechanisms associated between PACs desorption/sequestration and the abiotic influence of climate. Results of this work will further help understanding and predict the rate of natural attenuation of PACs in contaminated soils for the incoming decades.

Dagois, Robin; Schwartz, Christophe; Faure, Pierre

2014-05-01

284

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

SciTech Connect

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

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

1998-09-01

285

Innovative Technology Summary Report: Fiber Optic/Cone Penetrometer System for Subsurface Heavy Metals Detection. Subsurface Contaminants Focus Area and Industry Programs.  

National Technical Information Service (NTIS)

The purpose of this project is to develop an integrated fiber optic sensor/cone penetrometer system to analyze the heavy-metals content of the subsurface. This site characterization tool will use the penetrometer to deploy an optical fiber chemical sensor...

2000-01-01

286

Hydrocarbon contamination in groundwaters: Removal by alcohol flooding. Technical completion report, 1 May 1988-30 April 1990  

SciTech Connect

Present pump-and-treat remediation strategies employed to remove hydrocarbon contaminants that exist in groundwater as nonaqueous phase liquids (NAPLs) can displace only a fraction of the contaminant due to the trapping effects of capillary forces. These effects however are shown to be effectively eliminated by injecting alcohol solutions through the contamination zone. A laboratory column apparatus was developed to simulate NAPL contamination, free product recovery, and residual NAPL removal by alcohol flooding. Columns were packed with either glass beads or a South Carolina aquifer soil, and contaminated in preliminary experiments with benzene (a light NAPL) and in final experiments with trichloroethylene (TCE) (a dense NAPL). Proper scaling of the column was found to be critical in ensuring that the laboratory results adequately represented field-scale conditions.

Farley, K.J.; Boyd, G.R.; Patwardhan, S.

1992-05-01

287

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.

Agrawal, Akhil; Gieg, Lisa M.

2013-01-01

288

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

289

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

290

Phytoremediation of hydrocarbon contaminants in subantarctic soils: An effective management option.  

PubMed

Accidental fuel spills on world heritage subantarctic Macquarie Island have caused considerable contamination. Due to the island's high latitude position, its climate, and its fragile ecosystem, traditional methods of remediation are unsuitable for on-site clean up. We investigated the tolerance of a subantarctic native tussock grass, Poa foliosa (Hook. f.), to Special Antarctic Blend (SAB) diesel fuel and its potential to reduce SAB fuel contamination via phytoremediation. Toxicity of SAB fuel to P. foliosa was assessed in an 8 month laboratory growth trial under growth conditions which simulated the island's environment. Single seedlings were planted into 1 L pots of soil spiked with SAB fuel at concentrations of 1000, 5 000, 10 000, 2000 and 40 000 mg/kg (plus control). Plants were harvested at 0, 2, 4 and 8 months and a range of plant productivity endpoints were measured (biomass production, plant morphology and photosynthetic efficiency). Poa foliosa was highly tolerant across all SAB fuel concentrations tested with respect to biomass, although higher concentrations of 20 000 and 40 000 mg SAB/kg soil caused slight reductions in leaf length, width and area. To assess the phytoremediation potential of P. foliosa (to 10 000 mg/kg), soil from the planted pots was compared with that from paired unplanted pots at each SAB fuel concentration. The effect of the plant on SAB fuel concentrations and the associated microbial communities found within the soil (total heterotrophs and hydrocarbon degraders) were compared between planted and unplanted treatments at the 0, 2, 4 and 8 month harvest periods. The presence of plants resulted in significantly less SAB fuel in soils at 2 months and a return to background concentration by 8 months. Microbes did not appear to be the sole driving force behind the observed hydrocarbon loss. This study provides evidence that phytoremediation using P. foliosa is a valuable remediation option for use at Macquarie Island, and may be applicable to the management of fuel spills in other cold climate regions. PMID:24836716

Bramley-Alves, Jessica; Wasley, Jane; King, Catherine K; Powell, Shane; Robinson, Sharon A

2014-09-01

291

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

PubMed Central

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

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

2005-01-01

292

The effects of petroleum hydrocarbon and heavy metal contamination of marine sediments on recruitment of Antarctic soft-sediment assemblages: a field experimental investigation  

Microsoft Academic Search

A manipulative field experiment was conducted at Casey Station, Antarctica, to determine the effect of contamination of marine sediments on the recruitment and development of soft-sediment assemblages. Uncontaminated marine sediments were defaunated and then contaminated by adding hydrocarbons (diesel fuel and lubrication oil) or heavy metals (extracted from contaminated soil) prior to deployment on the seabed for a period of

Jonathan S Stark; Ian Snape; Martin J Riddle

2003-01-01

293

Studies on bioremediation of polycyclic aromatic hydrocarbon-contaminated sediments: bioavailability, biodegradability, and toxicity issues.  

PubMed

The widespread contamination by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes. This research studied a chronically PAH-contaminated estuarine sediment from the East River (ER; NY, USA) characterized by high concentrations of PAHs (approximately 4-190 ppm), sulfide, and metals and a marine sediment from New York/ New Jersey Harbor (NY/NJH; USA) with only trace quantities of PAHs (0.1-0.6 ppm). The focus was to examine the relationship between bioavailability of PAHs and their biological removal in a slurry system. Freshwater and marine sediment toxicity tests were conducted to measure baseline toxicity of both sediments to amphipods, aquatic worms, fathead and sheepshead minnow larvae, and a vascular plant; to determine the cause of toxicity; and to evaluate the effectiveness of the biotreatment strategies in reducing toxicity. Results showed the ER sediment was acutely toxic to all freshwater and marine organisms tested and that the toxicity was mainly caused by sulfide, PAHs, and metals present in the sediment. In spite of the high toxicity, most of the PAH compounds showed significant degradation in the aerobic sediment/water slurry system if the initial high oxygen demand due to the high sulfide content of the sediment was overcome. The removal of PAHs by biodegradation was closely related to their desorbed amount in 90% isopropanol solution during 24 h of contact, while the desorption of model PAH compounds from freshly spiked NY/NJH sediment did not describe the bioavailability of PAHs in the East River sediment well. The research improves our understanding of bioavailability as a controlling factor in bioremediation of PAHs and the potential of aerobic biodegradation for PAH removal and ecotoxicity reduction. PMID:12627632

Tabak, Henry H; Lazorchak, James M; Lei, Li; Khodadoust, Amid P; Antia, Jimmy E; Bagchi, Rajesh; Suidan, Makram T

2003-03-01

294

Contamination, source, and input route of polycyclic aromatic hydrocarbons in historic wastewater-irrigated agricultural soils.  

PubMed

Contamination by polycyclic aromatic hydrocarbons (PAHs) of historic wastewater-irrigated agricultural topsoil (0-5 cm) and the contribution of groundwater irrigation and atmospheric deposition to soil PAHs were studied in a typical agricultural region, i.e. Hunpu region, Liaoning, China. Concentrations of total PAHs ranged from 0.43 to 2.64 mg kg?¹ in topsoil, being lower than those found in other wastewater-irrigated areas. The levels of PAHs in soil declined as the distance from a water source increased. Concentrations of individual PAHs were generally higher in upland than in paddy topsoils. The calculated nemerow composite index showed that agricultural soil in the region was "polluted" by PAHs. A human health risk assessment based on the total toxic equivalent concentration showed that the presence of elevated concentrations of PAHs in the soil might pose a great threat to the health of local residents. Ratios of pairs of PAHs and principal component analysis (PCA) showed that pyrogenesis, such as coal combustion, was the main source of PAHs, while petroleum, to some extent, also had a strong influence on PAHs contamination in upland soil. The distribution patterns of individual PAHs and composition of PAHs differed between irrigation groundwater and topsoil, but were similar between atmospheric deposition and topsoil. There were significant linear correlations (r = 0.90; p < 0.01) between atmospheric deposition rates and average concentrations of the 16 individual PAHs in soils, while no significant relationships were observed between irrigation groundwater and topsoil in levels of PAHs. These suggested that PAHs in agricultural soils were mainly introduced from atmospheric deposition, rather than from groundwater irrigation after the phasing out of wastewater irrigation in the region since 2002. This study provides a reference to ensure agricultural product safety, pollution control, and proper soil management. PMID:23072782

Wang, Ning; Li, Hong-Bo; Long, Jin-Lin; Cai, Chao; Dai, Jiu-Lan; Zhang, Juan; Wang, Ren-Qing

2012-12-01

295

Characteristics in oxidative degradation by ozone for saturated hydrocarbons in soil contaminated with diesel fuel.  

PubMed

Although alkanes are relatively less reactive to chemical oxidation compared to alkenes, the chemical oxidation of alkanes has not been adequately explored in the context of environmental remediation efforts. Laboratory-scale column experiments were therefore conducted with soil artificially contaminated by diesel fuel as a surrogate for alkanes of environmental relevance. Particular attention was paid to saturated hydrocarbons refractory to volatilization. Reaction conditions involve 1485mgkg(-1) of the initial concentration of diesel range organics (DRO) and a constant ozone concentration of 119+/-6mgl(-1) at the flow rate of 50mlmin(-1). The observed removal of DRO reached 94% over 14h of continuous ozone injection. Ozone oxidation demonstrated effective removal of non-volatile DRO in the range of C(12)-C(24). Each alkane compound displayed comparable degradation kinetics, suggesting virtually no selectivity of ozone reactions with alkanes in soil. A pseudo-first order kinetic model closely simulated the removal kinetics, yielding a reaction rate constant of 0.213 (+/-0.021)h(-1) and a half-life of 3.3 (+/-0.3)h under the experimental conditions used in this study. An estimate of ozone demand was 32mg of O(3) (mgDRO)(-1). PMID:16872663

Yu, Do-Yun; Kang, Namgoo; Bae, Wookeun; Banks, M Katherine

2007-01-01

296

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

297

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

PubMed

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, 55 and 70 degrees C). Three tests were performed; firstly, soil was composted with green-waste, with a moisture content of 60%. Secondly, microbial activity was HgCl2-inhibited in the soil green-waste mixture with a moisture content of 60%, to evaluate abiotic losses, while in the third experiment only soil was incubated at the three different temperatures. PAHs and microbial populations were monitored. PAHs were lost from all treatments with 38 degrees C being the optimum temperature for both PAH removal and microbial activity. Calculated activation energy values (E(a)) for total PAHs suggested that the main loss mechanism in the soil-green waste reactors was biological, whereas in the soil reactors it was chemical. Total PAH losses in the soil-green waste composting mixtures were by pseudo-first order kinetics at 38 degrees C (k = 0.013 day(-1), R2 = 0.95), 55 degrees C (k = 0.010 day(-1), R2 = 0.76) and at 70 degrees C (k = 0.009 day(-1), R2 = 0.73). PMID:15823743

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

2005-01-01

298

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

PubMed

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

Wang, Xiaojing; Zou, Zhihong; Zou, Hui

2013-10-01

299

Identification of persulfate oxidation products of polycyclic aromatic hydrocarbon during remediation of contaminated soil.  

PubMed

The extent of PAH transformation, the formation and transformation of reaction byproducts during persulfate oxidation of polycyclic aromatic hydrocarbons (PAHs) in coking plant soil was investigated. Pre-oxidation analyses indicated that oxygen-containing PAHs (oxy-PAHs) existed in the soil. Oxy-PAHs including 1H-phenalen-1-one, 9H-fluoren-9-one, and 1,8-naphthalic anhydride were also produced during persulfate oxidation of PAHs. Concentration of 1,8-naphthalic anhydride at 4h in thermally activated (50°C) persulfate oxidation (TAPO) treatment increased 12.7 times relative to the oxidant-free control. Additionally, the oxy-PAHs originally present and those generated during oxidation can be oxidized by unactivated or thermally activated persulfate oxidation. For example, 9H-fluoren-9-one concentration decreased 99% at 4h in TAPO treatment relative to the control. Thermally activated persulfate resulted in greater oxy-PAHs removal than unactivated persulfate. Overall, both unactivated and thermally activated persulfate oxidation of PAH-contaminated soil reduced PAH mass, and oxidized most of the reaction byproducts. Consequently, this treatment process could limit environmental risk related to the parent compound and associated reaction byproducts. PMID:24862467

Liao, Xiaoyong; Zhao, Dan; Yan, Xiulan; Huling, Scott G

2014-07-15

300

Bioremediation of weathered petroleum hydrocarbon soil contamination in the Canadian High Arctic: laboratory and field studies.  

PubMed

The bioremediation of weathered medium- to high-molecular weight petroleum hydrocarbons (HCs) in the High Arctic was investigated. The polar desert climate, contaminant characteristics, and logistical constraints can make bioremediation of persistent HCs in the High Arctic challenging. Landfarming (0.3 m(3) plots) was tested in the field for three consecutive years with plots receiving very little maintenance. Application of surfactant and fertilizers, and passive warming using a greenhouse were investigated. The field study was complemented by a laboratory experiment to better understand HC removal mechanisms and limiting factors affecting bioremediation on site. Significant reduction of total petroleum HCs (TPH) was observed in both experiments. Preferential removal of compounds nC16 occurred, whereas in the field, TPH reduction was mainly limited to removal of compounds nC16 was observed in the fertilized field plots only. The greenhouse increased average soil temperatures and extended the treatment season but did not enhance bioremediation. Findings suggest that temperature and low moisture content affected biodegradation of HCs in the field. Little volatilization was measured in the laboratory, but this process may have been predominant in the field. Low-maintenance landfarming may be best suited for remediation of HCs compounds

Sanscartier, David; Laing, Tamsin; Reimer, Ken; Zeeb, Barbara

2009-11-01

301

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

SciTech Connect

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

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

2000-05-15

302

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

303

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

304

[Contamination characters of polycyclic aromatic hydrocarbons in Daliao River system of China].  

PubMed

With GC/MS, a quantitative study was made on the polycyclic aromatic hydrocarbons (PAHs) in the surface water and suspended particulates in Daliao River system, with their spatial distribution and sources investigated. The results showed that the total PAHs concentration ranged from 946.1 to 13 448.5 ng x L(-1) in surface water, and from 317.5 to 238 518.7 ng x g in suspended particulates. The PAHs concentration was decreased in the order of Taizi River > Daliao River > Hunhe River. The PAHs in surface water were dominated by 3-5 rings, while those in suspended particulates were dominated by 2 rings. The calculated ratios of selected PAHs suggested that the discharges from municipal, petrochemical and steel industrial wastewater, and the atmospheric fallout might be the important PAHs sources, and the contamination sources of PAHs were the mixture of petrogenic and pyrolytic inputs. In comparing with other river and marine systems in the world, Daliao River system had higher concentrations of PAHs in its surface water and suspended particulates, and thus, presented certain ecological risk. PMID:17886647

Guo, Wei; He, Meng-Chang; Yang, Zhi-Feng; Lin, Chun-Ye; Quan, Xiang-Chun; Wang, Hao-Zheng

2007-07-01

305

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

PubMed Central

Summary Field metabolomics and laboratory assays were used to assess the in situ anaerobic attenuation of hydrocarbons in a contaminated aquifer underlying 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 of alkylbenzenes, including the trimethylbenzene COC, PAHs and several n?alkanes in the contaminated portions of the aquifer. Anaerobic biodegradation experiments designed to mimic in situ conditions showed no loss of exogenously amended COC; however, a substantive rate of endogenous electron acceptor reduction was measured (55?±?8?µM SO4 day?1). An assessment of hydrocarbon loss in laboratory experiments relative to a conserved internal marker revealed that non?COC hydrocarbons were being metabolized. Purge and trap analysis of laboratory assays showed a substantial loss of toluene, m? and o?xylene, as well as several alkanes (C6–C12). Multiple lines of evidence suggest that benzene is persistent under the prevailing site anaerobic conditions. We could find no in situ benzene intermediates (phenol or benzoate), the parent molecule proved recalcitrant in laboratory assays and low copy numbers of Desulfobacterium were found, a genus previously implicated in anaerobic benzene biodegradation. This study also showed that there was a reasonable correlation between field and laboratory findings, although with notable exception. Thus, while the intrinsic anaerobic bioremediation was clearly evident at the site, non?COC hydrocarbons were preferentially metabolized, even though there was ample literature precedence for the biodegradation of the target molecules.

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

2009-01-01

306

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

307

Biodegradation of an Alicyclic Hydrocarbon by a Sulfate-Reducing Enrichment from a Gas Condensate-Contaminated Aquifer  

PubMed Central

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

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

2003-01-01

308

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

309

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

310

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

311

Bioremediation of petroleum hydrocarbons in contaminated soils: comparison of biosolids addition, carbon supplementation, and monitored natural attenuation  

Microsoft Academic Search

Two methods of biostimulation were compared in a laboratory incubation study with monitored natural attenuation (MNA) for total petroleum hydrocarbon (TPH) degradation in diesel-contaminated Tarpley clay soil with low carbon content. One method utilized rapid-release inorganic fertilizers rich in N and P, and the other used sterilized, slow-release biosolids, which added C in addition to N and P. After 8

Dibyendu Sarkar; Michael Ferguson; Rupali Datta; Stuart Birnbaum

2005-01-01

312

Abiotic behavior of entrapped petroleum products in the subsurface during leaching  

Microsoft Academic Search

Petroleum products are generally volatile hydrocarbon mixtures. These mixtures may contaminate land surfaces, the unsaturated zone and ground waters at numerous sites and thus represent a long-term source of environmental subsurface pollution. Based on laboratory and field evidence obtained by our research groups and others we emphasize in the present review paper the effect of leaching on the abiotic processes

Ishai Dror; Zev Gerstl; Rene Prost; Bruno Yaron

2002-01-01

313

Enumeration and characterization of the soil microflora from hydrocarbon-contaminated soil sites able to mineralize polycyclic aromatic hydrocarbons (PAH)  

Microsoft Academic Search

The use of a plate screening technique allowed the direct isolation and quantification of polycylic aromatic hydrocarbon (PAH)-degrading bacteria from different soil sites. Bacteria that were able to grow on anthracene, phenanthrene, fluoranthene or pyrene as a sole carbon source were found with numbers between 103 and 105 colony-forming units (cfu)\\/g of soil dry weight, but only in samples that

M. Kästner; M. Breuer-Jammali; B. Mahro

1994-01-01

314

Apparent Contradiction: Psychrotolerant Bacteria from Hydrocarbon-Contaminated Arctic Tundra Soils That Degrade Diterpenoids Synthesized by Trees  

PubMed Central

Resin acids are tricyclic terpenoids occurring naturally in trees. We investigated the occurrence of resin acid-degrading bacteria on the Arctic tundra near the northern coast of Ellesmere Island (82°N, 62°W). According to most-probable-number assays, resin acid degraders were abundant (103 to 104 propagules/g of soil) in hydrocarbon-contaminated soils, but they were undetectable (<3 propagules/g of soil) in pristine soils from the nearby tundra. Plate counts indicated that the contaminated and the pristine soils had similar populations of heterotrophs (106 to 107 propagules/g of soil). Eleven resin acid-degrading bacteria belonging to four phylogenetically distinct groups were enriched and isolated from the contaminated soils, and representative isolates of each group were further characterized. Strains DhA-91, IpA-92, and IpA-93 are members of the genus Pseudomonas. Strain DhA-95 is a member of the genus Sphingomonas. All four strains are psychrotolerant, with growth temperature ranges of 4°C to 30°C (DhA-91 and DhA-95) or 4°C to 22°C (IpA-92 and IpA-93) and with optimum temperatures of 15 to 22°C. Strains DhA-91 and DhA-95 grew on the abietanes, dehydroabietic and abietic acids, but not on the pimaranes, isopimaric and pimaric acids. Strains IpA-92 and IpA-93 grew on the pimaranes but not the abietanes. All four strains grew on either aliphatic or aromatic hydrocarbons, which is unusual for described resin acid degraders. Eleven mesophilic resin acid degraders did not use hydrocarbons, with the exception of two Mycobacterium sp. strains that used aliphatic hydrocarbons. We conclude that hydrocarbon contamination in Arctic tundra soil indirectly selected for resin acid degraders, selecting for hydrocarbon degraders that coincidentally use resin acids. Psychrotolerant resin acid degraders are likely important in the global carbon cycle and may have applications in biotreatment of pulp and paper mill effluents.

Yu, Zhongtang; Stewart, Gordon R.; Mohn, William W.

2000-01-01

315

Apparent contradiction: psychrotolerant bacteria from hydrocarbon-contaminated arctic tundra soils that degrade diterpenoids synthesized by trees.  

PubMed

Resin acids are tricyclic terpenoids occurring naturally in trees. We investigated the occurrence of resin acid-degrading bacteria on the Arctic tundra near the northern coast of Ellesmere Island (82 degrees N, 62 degrees W). According to most-probable-number assays, resin acid degraders were abundant (10(3) to 10(4) propagules/g of soil) in hydrocarbon-contaminated soils, but they were undetectable (<3 propagules/g of soil) in pristine soils from the nearby tundra. Plate counts indicated that the contaminated and the pristine soils had similar populations of heterotrophs (10(6) to 10(7) propagules/g of soil). Eleven resin acid-degrading bacteria belonging to four phylogenetically distinct groups were enriched and isolated from the contaminated soils, and representative isolates of each group were further characterized. Strains DhA-91, IpA-92, and IpA-93 are members of the genus Pseudomonas. Strain DhA-95 is a member of the genus Sphingomonas. All four strains are psychrotolerant, with growth temperature ranges of 4 degrees C to 30 degrees C (DhA-91 and DhA-95) or 4 degrees C to 22 degrees C (IpA-92 and IpA-93) and with optimum temperatures of 15 to 22 degrees C. Strains DhA-91 and DhA-95 grew on the abietanes, dehydroabietic and abietic acids, but not on the pimaranes, isopimaric and pimaric acids. Strains IpA-92 and IpA-93 grew on the pimaranes but not the abietanes. All four strains grew on either aliphatic or aromatic hydrocarbons, which is unusual for described resin acid degraders. Eleven mesophilic resin acid degraders did not use hydrocarbons, with the exception of two Mycobacterium sp. strains that used aliphatic hydrocarbons. We conclude that hydrocarbon contamination in Arctic tundra soil indirectly selected for resin acid degraders, selecting for hydrocarbon degraders that coincidentally use resin acids. Psychrotolerant resin acid degraders are likely important in the global carbon cycle and may have applications in biotreatment of pulp and paper mill effluents. PMID:11097882

Yu, Z; Stewart, G R; Mohn, W W

2000-12-01

316

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

317

Hydrocarbons contamination and microbial degradation in mangrove sediments of the Niger Delta region (Nigeria)  

Microsoft Academic Search

The distribution of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), and their degradability by bacteria in epipelic and benthic sediments from Qua Iboe Estuary mangrove ecosystem and associated creeks were investigated. The research findings revealed that total aliphatic hydrocarbons in sediments ranged from 16.82 mg·kg to 210 mg kg , wheras total PAHs ranged from 6.30 to 35.55 mg·kg dry weight of sediment.

J. P. Essien; G. A. Ebong; J. E. Asuquo; A. A. Olajire

2012-01-01

318

The extent and significance of petroleum hydrocarbon contamination in Crater Lake, Oregon  

Microsoft Academic Search

In order to evaluate hydrocarbon inputs to Crater Lake from anthropogenic and natural sources, samples of water, aerosol,\\u000a surface slick and sediment were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) for determination of\\u000a their aliphatic and aromatic hydrocarbon concentrations and compositions. Results show that hydrocarbons originate from both\\u000a natural (terrestrial plant waxes and algae) and anthropogenic (petroleum use) sources

Daniel R. Oros; Robert W. Collier; Bernd R. T. Simoneit

319

The extent and significance of petroleum hydrocarbon contamination in Crater Lake, Oregon  

Microsoft Academic Search

In order to evaluate hydrocarbon inputs to Crater Lake from anthropogenic and natural sources, samples of water, aerosol,\\u000a surface slick and sediment were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) for determination of\\u000a their aliphatic and aromatic hydrocarbon concentrations and compositions. Results show that hydrocarbons originate from both\\u000a natural (terrestrial plant waxes and algae) and anthropogenic (petroleum use) sources

Daniel R. Oros; Robert W. Collier; Bernd R. T. Simoneit

2007-01-01

320

Partial Characterization of Biosurfactant from Lactobacillus pentosus and Comparison with Sodium Dodecyl Sulphate for the Bioremediation of Hydrocarbon Contaminated Soil  

PubMed Central

The capability of a cell bound biosurfactant produced by Lactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-). The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR) that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage), as well as CH2–CH3 and C–O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000?mg?Kg?1 of octane was treated with biosurfactant from L. pentosus or SDS. Treatment of soil for 15 days with the biosurfactant produced by L. pentosus led to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced by L. pentosus accelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment.

Moldes, A. B.; Paradelo, R.; Vecino, X.; Cruz, J. M.; Gudina, E.; Rodrigues, L.; Teixeira, J. A.; Dominguez, J. M.; Barral, M. T.

2013-01-01

321

Partial characterization of biosurfactant from Lactobacillus pentosus and comparison with sodium dodecyl sulphate for the bioremediation of hydrocarbon contaminated soil.  

PubMed

The capability of a cell bound biosurfactant produced by Lactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-). The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR) that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage), as well as CH2-CH3 and C-O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000 mg Kg(-1) of octane was treated with biosurfactant from L. pentosus or SDS. Treatment of soil for 15 days with the biosurfactant produced by L. pentosus led to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced by L. pentosus accelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment. PMID:23691515

Moldes, A B; Paradelo, R; Vecino, X; Cruz, J M; Gudiña, E; Rodrigues, L; Teixeira, J A; Domínguez, J M; Barral, M T

2013-01-01

322

Petroleum hydrocarbon biodegradation under seasonal freeze-thaw soil temperature regimes in contaminated soils from a sub-Arctic site.  

PubMed

Several studies have shown that biostimulation in ex situ systems such as landfarms and biopiles can facilitate remediation of petroleum hydrocarbon contaminated soils at sub-Arctic sites during summers when temperatures are above freezing. In this study, we examine the biodegradation of semivolatile (F2: C10-C16) and nonvolatile (F3: C16-C34) petroleum hydrocarbons and microbial respiration and population dynamics at post- and presummer temperatures ranging from -5 to 14 °C. The studies were conducted in pilot-scale tanks with soils obtained from a historically contaminated sub-Arctic site in Resolution Island (RI), Canada. In aerobic, nutrient-amended, unsaturated soils, the F2 hydrocarbons decreased by 32% during the seasonal freeze-thaw phase where soils were cooled from 2 to -5 °C at a freezing rate of -0.12 °C d(-1) and then thawed from -5 to 4 °C at a thawing rate of +0.16 °C d(-1). In the unamended (control) tank, the F2 fraction only decreased by 14% during the same period. Biodegradation of individual hydrocarbon compounds in the nutrient-amended soils was also confirmed by comparing their abundance over time to that of the conserved diesel biomarker, bicyclic sesquiterpanes (BS). During this period, microbial respiration was observed, even at subzero temperatures when unfrozen liquid water was detected during the freeze-thaw period. An increase in culturable heterotrophs and 16S rDNA copy numbers was noted during the freezing phase, and the (14)C-hexadecane mineralization in soil samples obtained from the nutrient-amended tank steadily increased. Hydrocarbon degrading bacterial populations identified as Corynebacterineae- and Alkanindiges-related strains emerged during the freezing and thawing phases, respectively, indicating there were temperature-based microbial community shifts. PMID:21194195

Chang, Wonjae; Klemm, Sara; Beaulieu, Chantale; Hawari, Jalal; Whyte, Lyle; Ghoshal, Subhasis

2011-02-01

323

Source identification of hydrocarbon contaminants and their transportation over the Zonguldak shelf, Turkish Black Sea  

NASA Astrophysics Data System (ADS)

Under great anthropogenic pressure due to the substantial freshwater input from the surrounding industrial and agricultural areas, especially central and middle-Eastern Europe, the Black Sea basin is ranked among the most ecologically threatened water bodies of the world. Oil levels are unacceptable in many coastal areas perilously close to polluted harbors and many river mouths; the places presenting the highest levels of bio-diversity and having a high socio-economic importance due to human use of coastal resources. There are about sixty sources of pollution which resulted in "hot spots" having disastrous impacts on sensitive marine and coastal areas and needing immediate priorities for action. Beyond such land-based sources, trans-boundary pollution sources from Black Sea riparian countries, heavy maritime traffic, particularly involving petroleum transports and fishing boats, and the improper disposal of ballast and bilge waters and solid waste are also important marine sources of pollution. Found in fossil fuels such as Polycyclic Aromatic Hydrocarbons are generated by incomplete combustion of organic matter. In order to estimate their distribution in sediment and their sources, they were monitored from the bottom samples offshore the Zonguldak industry region, one of the most polluted spots in the Turkish Black Sea. There the budget of pollutants via rivers is not precisely known due to an evident lack of data on chemical and granulometric composition of the river runoff and their fluxes. Therefore the marine sediments, essential components of marine ecosystems, are very important in our estimating the degree of the damage given to the ecosystem by such inputs. Realization of the sources and transport of these contaminants will be a critical tool for future management of the Zonguldak industry region and its watershed. The sea bottom in study area is composed of mainly sand and silt mixtures with small amount of clay. Geochemical analyses have shown that oil contamination was dominated in near-shore sediments. Their spatial distributions over the shelf area make an estimation of possible pollution sources and their transportation routes possible. Sea port activities, industrial inputs and partly maritime petroleum transport are the main sources of pollutants. They are under the control of the longshore currents supplied with river alluvium and coastal abrasion material.

Unlu, S.; Alpar, B.

2009-04-01

324

Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons.  

PubMed

Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAHs), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a seminatural, two-year weathering period on PAH/oil chemistry and toxicity in a marine sediment that had been spiked with three different oils (a gas oil, a lubricating oil, and a crude oil; all tested at five concentrations). Toxicity of bioavailable, pore water-accommodated oil/PAH fractions was quantified using a bacterial (Vibrio fischeri) assay and the in vitro chemical-activated luciferase expression assay (DR-CALUX; using conditions to detect PAHs). Results of chemical analyses pointed to (microbial) degradation of all three oils: Sediment oxygen demand during weathering increased with increasing oil concentration, total oil concentrations decreased to between 17 and 29% of initial levels, and resolved n-alkanes were depleted in weathered oil fractions. Furthermore, a shift in the relative importance of different boiling-point fraction ranges of the oils was observed on weathering. Generally, the lowest fraction range (C10-C16) disappeared, whereas the relative proportion of the highest (C28-C40) fraction range increased considerably. Remarkably, for the gas oil, this fraction shift was dependent on the oil concentration in sediment. Similarly, degradation of PAHs was strongly affected by the sedimentary oil content, indicating that the presence of oil stimulated PAH degradation. This phenomenon applied to both low- and high-molecular-weight PAHs, although the first group (3- and 4-ring PAHs) was degraded most. Results from the V. fischeri and DR-CALUX assay showed that in most cases, pore-water toxicity decreased on weathering. Combining the assay responses with chemical data indicated that the observed toxicity probably was not caused by the analyzed PAHs but, rather, by specific oil constituents instead. PMID:16704068

Jonker, Michiel T O; Brils, Jos M; Sinke, Anja J C; Murk, Albertinka J; Koelmans, Albert A

2006-05-01

325

Assessment of diesel contamination in groundwater using electromagnetic induction geophysical techniques  

SciTech Connect

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

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

2008-07-01

326

Separation of motor oils, oily wastes and hydrocarbons from contaminated water by sorption on chrome shavings  

Microsoft Academic Search

In this paper, the ability of chrome shavings to remove motor oils, oily wastes and hydrocarbons from water has been studied. To determine amount of hydrocarbons sorbed on tanned wastes, a FT-NIR methodology was used and a multivariate calibration based on partial least squares (PLS) was employed for data treatment. The light density, porous tanned waste granules float on the

A. Gammoun; S. Tahiri; A. Albizane; M. Azzi; J. Moros; S. Garrigues; M. de la Guardia

2007-01-01

327

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 ...

328

Separation of motor oils, oily wastes and hydrocarbons from contaminated water by sorption on chrome shavings.  

PubMed

In this paper, the ability of chrome shavings to remove motor oils, oily wastes and hydrocarbons from water has been studied. To determine amount of hydrocarbons sorbed on tanned wastes, a FT-NIR methodology was used and a multivariate calibration based on partial least squares (PLS) was employed for data treatment. The light density, porous tanned waste granules float on the surface of water and remove hydrocarbons and oil films. Wastes fibers from tannery industry have high sorption capacity. These tanned solid wastes are capable of absorbing many times their weight in oil or hydrocarbons (6.5-7.6g of oil and 6.3g of hydrocarbons per gram of chrome shavings). The removal efficiency of the pollutants from water is complete. The sorption of pollutants is a quasi-instantaneous process. PMID:17157981

Gammoun, A; Tahiri, S; Albizane, A; Azzi, M; Moros, J; Garrigues, S; de la Guardia, M

2007-06-25

329

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

330

Short Communication: A method for extraction of DNA and PCR-based detection of polycyclic aromatic hydrocarbon-degrading bacteria in soil contaminated with oil and grease  

Microsoft Academic Search

A protocol for extraction of microbial DNA from oil-and grease-saturated soil is reported that can be used to target availability of specific genotypes of bacteria in extensively contaminated soils using the polymerase chain reaction. The methodology developed can be used in the biotreatibility studies for in situ bioremediation of hydrocarbon-contaminated sites.

P. Padmanabhan; R. Shanker; P. Khanna

1998-01-01

331

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

332

Ecohydrological Linkage Between Surface-Derived Dissolved Organic Matter and Subsurface Carrying Capacity for Unattached Subsurface Bacterial Populations: Implications for Biodegradation in Contaminated Groundwater Environments  

NASA Astrophysics Data System (ADS)

Degradation by aquifer microbial populations of dissolved organic matter (DOM) transported from the surface environment exerts strong controls on the concentration, composition, and reactivity of DOM as it is transported in ground water. In turn, the quantity of readily degradable DOM may be a major control of the carrying capacity for bacteria in groundwater and, consequently, would affect the fate of lower levels of organic contaminants being advected through the same sediments. For a 5-km long plume of groundwater organic contaminants in a sandy aquifer at Cape Cod, Massachusetts, the partitioning of bacteria between solution and grain surfaces increased with decreasing distance downgradient from the source. In general, the unattached bacterial populations were particularly sensitive to the level of DOM present. Approximately 2/3 of the spatial variability for unattached bacteria within the upgradient 3 km of the contaminant plume can be explained statistically simply by the abundance of the more degradable (non alkyl benzene surfactant [ABS]) DOM, even though predation by groundwater nanoflagellates (protists) and sorptive-filtration of unattached bacteria both vary spatially. However, distance downgradient from the contaminant source, which directly correlates with both the age and abundance of the DOM, could explain ~98% of the variability of unattached bacteria along the longitudinal axis of the plume. Down-well incubations (USGS well site F513) were performed using membrane (100K Dalton cutoff) chambers (initially seeded with undifferentiated, laboratory-grown aquifer bacteria at abundances of 1 x 105 or of 1 x 107 bacteria/mL) that come to chemical equilibrium with surrounding groundwater within ~1 day. Following a 7-day down-well incubation, numbers of unattached bacteria within the chambers converged on a final abundance value of 2.0 ± 0.6 x 106 bacteria per mL, consistent with the in-situ bacterial abundance within that part of the plume (typically between 1.0 x 106 and 2.0 x 106/mL). Incubation for a longer (21 day) period resulted in final bacterial abundances that were not statistically different than those observed for the shorter (7-day) incubations. Results from the Cape Cod study suggests the carrying capacity of the system for unattached groundwater bacteria that are advecting downgradient with specific organic contaminants may be determined by the more degradable fraction of the DOM.

Harvey, R. W.; Gruden, C. L.; Aiken, G. R.; Metge, D. W.; Kinner, N. E.

2004-12-01

333

Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models  

DOEpatents

A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management.

He, Wei (New Milford, NJ); Anderson, Roger N. (New York, NY)

1998-01-01

334

Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models  

DOEpatents

A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management. 20 figs.

He, W.; Anderson, R.N.

1998-08-25

335

Arbuscular mycorrhizal fungi in chronically petroleum-contaminated soils in Mexico and the effects of petroleum hydrocarbons on spore germination.  

PubMed

Arbuscular mycorrhizal fungi (AMF) have been hypothesized to enhance plant adaptation and growth in petroleum-contaminated soils. Nevertheless, neither AMF-biodiversity under chronically petroleum-contaminated soils nor spore germination response to petroleum hydrocarbons has been well studied. Chronically petroleum-contaminated rhizosphere soil and roots from Echinochloa polystachya, Citrus aurantifolia and C. aurantium were collected from Activo Cinco Presidentes, Tabasco, Mexico. Root colonization and spore abundance were evaluated. Additionally, rhizosphere soil samples were propagated using Sorghum vulgare L. as a plant trap under greenhouse conditions; subsequently, AMF-spores were identified. AMF-colonization ranged from 63 to 77% while spore number ranged from 715 to 912 in 100 g soil, suggesting that AMF tolerate the presence of petroleum hydrocarbons in the rhizosphere. From grass species, four AMF-morphospecies were identified: Glomus ambisporum, G. sinuosum (previously described as Sclerocystis sinuosum), Acaulospora laevis, and Ambispora gerdermanni. From citrus trees, four AMF-species were also identified: Scutellospora heterogama, G. ambisporum, Acaulospora scrobiculata, and G. citricola. In a second study, it was observed that spore germination and hyphal length of G. mosseae, G. ambisporum, and S. heterogama were significantly reduced by either volatile compounds of crude oil or increased concentrations of benzo[a ]pyrene or phenanthrene in water-agar. PMID:17910101

Franco-Ramírez, Alicia; Ferrera-Cerrato, Ronald; Varela-Fregoso, Lucía; Pérez-Moreno, Jesús; Alarcón, Alejandro

2007-10-01

336

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

337

A comprehensive inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the INEL RWMC during the years 1984-2003, Volume 3  

SciTech Connect

This is the third volume of this comprehensive report of the inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the Idaho National Engineering Laboratory. Appendix B contains a complete printout of contaminant inventory and other information from the CIDRA Database and is presented in volumes 2 and 3 of the report.

NONE

1995-05-01

338

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

339

Innovative geochemical approaches to chronostratigraphy and hydrocarbon detection in subsurface: Neogene exploration wells, northern Gulf of Mexico  

SciTech Connect

Application of isotope chronostratigraphy to numerous exploration wells in the northern Gulf of Mexico provides a large data base for making stratigraphic correlations with resolutions of 20,000 years in the Pleistocene and 50,000 years in the Pliocene-Miocene. A composite record of the O-18 and C-13 of foraminifera for the last 4.5 m.y. enables the recognition of 131 O-18 stages and a similar number of C-13 stages independent of the O-18 stages. The integrated approach incorporating these complimentary stages and all available biostratigraphic information is used to derive a chronostratigraphy of unparalleled resolution in exploration wells. Within this absolute time framework, they have determined the timing and extent of more than five regional unconformities. These unconformities can be distinguished from those produced by more localized salt tectonics or growth faulting. The carbon isotopic composition of fine-grained sediments in exploration wells provides a combination of stratigraphic and geochemical information of importance to hydrocarbon exploration. The range in isotopic values seen in the fine-grained sediments is greater than 20 per thousand, which is extremely different than that observed in the biogenic carbonate. The C-13 record is characterized by a series of 2 to 6 per thousand shifts in mean isotopic value in both the positive and negative direction. Superimposed over these shifts are numerous events, mainly negative excursions, on the order of -2 to -10 per thousand. The chronology of the C-13 fine fraction records is based on the chronostratigraphy derived from the foraminiferal-based O-18 record. C-13 events and shifts can be used to correlate wells within exploration trends like the Flexure Trend. Some of the negative C-13 events appear to reflect the occurrence of calcite formed by the microbial biodegradation of crude oil and gas.

Trainor, D.M.; Williams, D.F.

1987-05-01

340

Comparative study of five polycyclic aromatic hydrocarbon degrading bacterial strains isolated from contaminated soils.  

PubMed

Five polycyclic aromatic hydrocarbon (PAH) degrading bacterial strains, Pseudomonas putida 34, Pseudomonas fluorescens 62, Pseudomonas aeruginosa 57, Sphingomonas sp. strain 107, and the unidentified strain PL1, were isolated from two contaminated soils and characterized for specific features regarding PAH degradation. Degradation efficiency was determined by the rapidity to form clearing zones around colonies when sprayed with different PAH solutions and the growth in liquid medium with different PAHs as sole source of carbon and energy. The presence of plasmids, the production of biosurfactants, the effect of salicylate on PAH degradation, the transformation of indole to indigo indicating the presence of an aromatic ring dioxygenase activity, and the hybridization with the SphAb prove representing a sequence highly homologous to the naphthalene dioxygenase ferredoxin gene nahAb were examined. The most efficient strain in terms of substrate specificity and rapidity to degrade different PAHs was Sphingomonas sp. strain 107, followed by strain PL1 and P. aeruginosa 57. The less efficient strains were P. putida 34 and P. fluorescens 62. Each strain transformed indole to indigo, except strain PL1. Biosurfactants were produced by P. aeruginosa 57 and P. putida 34, and a bioemulsifier was produced by Sphingomonas sp. strain 107. The presence of salicylate in solid medium has accelerated the formation of clearing zones and the transformation of indole by Sphingomonas sp. strain 107 and P. aeruginosa 57 colonies. Plasmids were found in Sphingomonas sp. strain 107 and strain PL1. The SphAb probe hybridized with DNA extracted from each strain. However, hybridization signals were detected only in the plasmidic fraction of Sphingomonas sp. strain 107 and strain PL1. Using a polymerase chain reaction (PCR) approach, we determined that several genes encoding enzymes involved in the upper catabolic pathway of naphthalene were present in each strain. Sequencing of PCR DNA fragments revealed that, for all the five strains, these genes are highly homologous with respective genes found in the pah, dox, and nah operons, and are arranged in a polycistronic operon. Results suggest that these genes are ordered in the five selected strains like the pah, nah, and dox operons. PMID:9115093

Dagher, F; Déziel, E; Lirette, P; Paquette, G; Bisaillon, J G; Villemur, R

1997-04-01

341

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.

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

2014-01-01

342

The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage.  

PubMed

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (?75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. PMID:24704958

Potashev, Konstantin; Sharonova, Natalia; Breus, Irina

2014-07-01

343

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

EPA Science Inventory

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

344

Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons  

Microsoft Academic Search

Environmentally persistent aromatic hydrocarbons known as unresolved complex mixtures (UCMs) derived from crude oil can be accumulated by, and elicit toxicological responses in, marine organisms (e.g. mussels, Mytilus edulis). Comprehensive two-dimensional gas chromatography time-of-flight mass-spectrometry (GC×GC–ToF-MS) previously revealed that these UCMs included highly branched alkylated aromatic hydrocarbons. Here, the effects of biodegradation on the toxicity and chemical composition of an

Max Frenzel; Alan Scarlett; Steven J. Rowland; Tamara S. Galloway; Sara K. Burton; Hilary M. Lappin-Scott; Andy M. Booth

2010-01-01

345

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

346

Stimulating in situ surfactant production to increase contaminant bioavailability and augment bioremediation of petroleum hydrocarbons  

Microsoft Academic Search

The effectiveness of a bioremediation strategy is largely dependent on relationships between contaminant sequestration (geochemical limitations) and microbial degradation potential (biological limitations). As contaminant bioavailability becomes mass transfer limited, contaminant removal will show less sensitivity to biodegradation enhancements without concurrent enhancements to rates of mass transfer into the bioavailable phase. Implementing a strategy that can simultaneously address geochemical and biological

N. W. Haws; H. W. Bentley; A. Yiannakakis; A. J. Bentley; D. P. Cassidy

2006-01-01

347

FORENSIC ANALYSIS AND SOURCE PARTITIONING OF ALIPHATIC HYDROCARBON CONTAMINATION IN LAKE MARUIT AQUATIC SEDIMENTS  

Microsoft Academic Search

Investigations of natural and\\/or engineered environmental systems require achieving a comprehensive characterization and identification of contaminants of concern. The differentiation of contaminant molecular markers (MMs) that originate from various sources is difficult when simply based only on their chemical compositions. Thus, a comprehensive forensic analysis coupled with source partitioning modeling is needed for characterizing contaminant compositions, predicting their possible transport,

TAREK A. KASSIM

348

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

PubMed Central

We assessed chlorinated hydrocarbon contamination of mink and river otters on the Columbia and Fraser River systems of northwestern North America, in relation to morphological measures of condition. We obtained carcasses of mink and river otters from commercial trappers during the winters 1994-1995 and 1995-1996. Necropsies included evaluation of the following biological parameters: sex, body mass and length, age, thymus, heart, liver, lung, spleen, pancreas, kidney, gonad, omentum, adrenal gland and baculum masses, baculum length, and stomach contents. Livers were analyzed, individually or in pools, for residues of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans. Contaminant levels were relatively low compared to those documented in other North American populations, although they ranged higher than those detected during an earlier survey (1990-1992) of these regional populations. Body condition varied slightly among collection regions, but showed no relationship with contaminant burden. Mink from the upper Fraser River had less fat stores and also had some of the lowest OC contamination levels observed. Similarly, a few individuals with enlarged livers and kidneys had low contaminant levels. Although a few individual animals with gross abnormalities of reproductive systems did not show high levels of contamination, there was a significant negative correlation between total PCB concentrations (as Aroclor 1260) and baculum length in juvenile mink (r = 0.707; p = 0.033; n = 8). The association of juvenile baculum length with eventual reproductive success is unknown, but further characterization of reproductive organ morphology and relationship to contaminants should be undertaken in a larger subset of these populations. Images Figure 1 Figure 2 Figure 3

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

1999-01-01

349

Verification and sensitivity of the calculational methods used in the PATHRAE code to predict subsurface contaminant transport for risk assessments of SRP waste sites  

SciTech Connect

Presented in this report are an independent verification of the subsurface contaminant transport calculations contained in the code and an assessment of the sensitivity of predicted contaminant concentrations to uncertainties in transport parameters. The subsurface transport approximation incorporated in the PATHRAE risk assessment code was compared with alternate two-dimensional and three-dimensional approximations and with the EPA VHS model. Agreement between the PATHRAE approximation and the alternate two-dimensional approximation was good. Due to its neglect of vertical dispersion, the PATHRAE model predicted higher groundwater (undiluted) concentrations than the three-dimensional approximation and, for EPA parameters, the VHS model. The use of a value of zero for horizontal dispersivity, as specified for 1 m and 100 m wells in SPR waste site analyses, was found to add an additional degree of conservatism to PATHRAE estimates of groundwater concentration, yielding levels that were more than three orders of magnitude higher than those of the three-dimensional model for a 100 m well. Implementation of the transport approximation in the PATHRAE code was verified by comparing code generated concentrations with those of an independent calculation for wide ranges of the input parameters. Agreement between PATHRAE and the independent calculations was excellent.

Fjeld, R.A.; Elzerman, A.W.; Overcamp, T.J.; Giannopoulos, N.; Crider, S.; Sill, B.L.

1986-10-01

350

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

351

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

352

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

353

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

354

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

355

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.

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

2003-01-01

356

Uncertainty based optimal monitoring network design for a chlorinated hydrocarbon contaminated site  

Microsoft Academic Search

An application of a newly developed optimal monitoring network for the delineation of contaminants in groundwater is demonstrated\\u000a in this study. Designing a monitoring network in an optimal manner helps to delineate the contaminant plume with a minimum\\u000a number of monitoring wells at optimal locations at a contaminated site. The basic principle used in this study is that the\\u000a wells

Sreenivasulu Chadalavada; Bithin Datta; Ravi Naidu

2011-01-01

357

Removal of hydrocarbon contaminant film from spacecraft optical surfaces using a radiofrequency-excited oxygen plasma.  

NASA Technical Reports Server (NTRS)

Results of a study on the feasibility of removing contaminant films from optical surfaces in vacuum, using an oxygen plasma, are discussed. Contaminant films were deposited onto optical surfaces from butadiene and methane gases at a pressure of about 4 torr in the presence of ultraviolet radiation. Optical surfaces evaluated included ultraviolet-reflecting mirrors, gratings, quartz disks, and spacecraft thermal control surfaces. In general, it was found that contaminants could be removed successfully from surfaces using an oxygen plasma. Exceptions were the white-paint thermal control surfaces, which, when contaminated, degraded further during exposure to the oxygen plasma.

Beverly, W. D.; Gillete, R. B.; Cruz, G. A.

1973-01-01

358

Hydrocarbons in the water and bottom sediments of a region with continuous petroleum contamination  

Microsoft Academic Search

The abundances and compositions of aliphatic hydrocarbons (AHC) and polyaromatic hydrocarbons (PAH) were investigated in the\\u000a water and bottom sediments of the southwestern Amur Bay in the Sea of Japan. The water contained from 0 to 129 ?g\\/1AHC (averaging\\u000a 42.2 ?g\\/l) and from 5 to 85 ng\\/l PAH (averaging 18 ng\\/l). The bottom sediments contained 168–2098 ?g\\/g AHC and 7.2–1100

I. A. Nemirovskaya

2007-01-01

359

Characterization of Rhodococcus opacus R7, a strain able to degrade naphthalene and o -xylene isolated from a polycyclic aromatic hydrocarbon-contaminated soil  

Microsoft Academic Search

Rhodococcus opacus R7 was isolated from a soil contaminated with polycyclic aromatic hydrocarbons for its ability to grow on naphthalene. The strain was also able to degrade o-xylene, the isomer of xylenes most recalcitrant to microbial degradation. The catabolic pathways for naphthalene and o-xylene were investigated by identification of metabolites in R. opacus R7 cultures performed with the two hydrocarbons and

Patrizia Di Gennaro; Emanuela Rescalli; Enrica Galli; Guido Sello; Giuseppina Bestetti

2001-01-01

360

Microbial community dynamics in uranium contaminated subsurface sediments under biostimulated conditions with high nitrate and nickel pressure  

Microsoft Academic Search

Background, aim, and scope  The subsurface at the Oak Ridge Field Research Center represents an extreme and diverse geochemical environment that places\\u000a different stresses on the endogenous microbial communities, including low pH, elevated nitrate concentrations, and the occurrence\\u000a of heavy metals and radionuclides, including hexavalent uranium [U(VI)]. The in situ immobilization of U(VI) in the aquifer\\u000a can be achieved through microbial

David Moreels; Garry Crosson; Craig Garafola; Denise Monteleone; Safiyh Taghavi; Jeffrey P. Fitts; Daniel van der Lelie

2008-01-01

361

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

Microsoft Academic Search

The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site

DONALD E. LANGWORTHY; R. H. Findlay; R. D. Stapleton; G. S. Sayler

1998-01-01

362

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

363

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

Microsoft Academic Search

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

Gerald T. Ankley; Scott A. Collyard; Philip D. Monson; Patricia A. Kosian

1994-01-01

364

Habitat function of agricultural soils as affected by heavy metals and polycyclic aromatic hydrocarbons contamination  

Microsoft Academic Search

Ecotoxic activity of soils polluted with polycyclic aromatic hydrocarbon (PAH) and heavy metals (HM) was evaluated in pot and laboratory experiments. Plants and soil microorganisms were chosen as test organisms and six different soil materials were used in the study. The applied levels of HM and PAH were aimed to reflect environmental conditions in the “worst case” situation. Zn2+, Pb2+

Barbara Maliszewska-Kordybach; Bo?ena Smreczak

2003-01-01

365

POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL  

EPA Science Inventory

Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

366

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

Microsoft Academic Search

The toxicity of certain polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms can be greatly increased upon exposure of the organisms to ultraviolet (UV) radiation present in sunlight. The phenomenon of photoactivation of PAHs had received some attention in the laboratory; however, evaluation of the photoinduced toxicity of PAHs in field settings has been limited. In these studies, in situ chambers

Philip D. Monson; Gerald T. Ankley; Patricia A. Kosian

1995-01-01

367

Development of radon-222 as a natural tracer for monitoring the remediation of NAPL contamination in the subsurface. 1998 annual progress report  

SciTech Connect

'The objective of this research is to develop a unique method of using naturally occurring radon-222 as a tracer for locating and quantitatively describing the presence of subsurface NAPL contamination. The research will evaluate using radon as an inexpensive, yet highly accurate, means of detecting NAPL contamination and assessing the effectiveness of NAPL remediation. Laboratory, field, and modeling studies are being performed to evaluate this technique, and to develop methods for its successful implementation in practice. This report summarizes work that has been accomplished after 1-year of a 3-year project. The research to date has included radon tracer tests in physical aquifer models (PAMs) and field studies at Site 300 of the Lawrence Livermore National Laboratory, CA, and Site 100D at Hanford DOE Facility, WA. The PAM tests have evaluated the ability of radon as a tracer to monitor the remediation of TCE NAPL contamination using surfactant treatment, and oxidation with permanganate. The surfactant tests were performed in collaboration with Dr. Jack Istok and Dr. Jennifer Field and their EMSP project ``In-situ, Field-Scale Evaluation of Surfactant Enhanced DNAPL Recovery Using a Single-Well-Push-Pull Test.'''' This collaboration enabled the EMSP radon project to make rapid progress. The PAM surfactant tests were performed in a radial flow geometry to simulate the push-pull-method that is being developed for surfactant field tests. The radon tests were easily incorporated into these experiments, since they simply rely on measuring the natural radon present in the subsurface fluids. Two types of radon tests were performed: (1) static tests where radon was permitted to build-up to steady-state concentrations in the pore fluids and the groundwater concentrations were monitored, and (2) dynamic tests were the radon response during push-pull surfactant tests was measured. Both methods were found to be useful in determining how NAPL remediation was progressing.'

Semprini, L.; Istok, J.

1998-06-01

368

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

369

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

370

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...

371

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 ...

372

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

373

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

NASA Astrophysics Data System (ADS)

Microorganisms participate in a variety of geologic processes that alter the chemical and physical properties of their environment. Understanding the geophysical signatures of microbial activity in the environment has resulted in the development of a new sub-discipline in geophysics called “biogeophysics”. This review focuses primarily on literature pertaining to biogeophysical signatures of sites contaminated by light non-aqueous phase liquids (LNAPL), as these sites provide ideal laboratories for investigating microbial-geophysical relationships. We discuss the spatial distribution and partitioning of LNAPL into different phases because the physical, chemical, and biological alteration of LNAPL and the subsequent impact to the contaminated environment is in large part due to its distribution. We examine the geophysical responses at contaminated sites over short time frames of weeks to several years when the alteration of the LNAPL by microbial activity has not occurred to a significant extent, and over the long-term of several years to decades, when significant microbial degradation of the LNAPL has occurred. A review of the literature suggests that microbial processes profoundly alter the contaminated environment causing marked changes in the petrophysical properties, mineralogy, solute concentration of pore fluids, and temperature. A variety of geophysical techniques such as electrical resistivity, induced polarization, electromagnetic induction, ground penetrating radar, and self potential are capable of defining the contaminated zones because of the new physical properties imparted by microbial processes. The changes in the physical properties of the contaminated environment vary spatially because microbial processes are controlled by the spatial distribution of the contaminant. Geophysical studies must consider the spatial variations in the physical properties during survey design, data analysis, and interpretation. Geophysical data interpretation from surveys conducted at LNAPL-contaminated sites without a microbial and geochemical context may lead to ambiguous conclusions.

Atekwana, Estella A.; Atekwana, Eliot A.

2010-03-01

374

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...

375

Polycyclic aromatic hydrocarbon (PAH) contamination in the urban topsoils of Shenyang, China  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) in the surface urban soils of Shenyang in Northeastern China were investigated. The total concentration of the PAHs ranged from 0.09 to 8.35 mg kg, with an average value of 1.51 ± 1.64 mg kg. 3–5-ring PAHs accounted for 90% of total PAHs. The functional areas, such as the industrial regions (4.95 mg kg) and main roads (1.56 mg kg),

Yuebing Sun; Guohong Sun; Qixing Zhou; Yingming Xu; Lin Wang; Xuefeng Liang; Yang Sun; Xu Qin

2012-01-01

376

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

PubMed

In the mid-1990s, a groundwater plume of uranium (U) was detected in monitoring wells in the B-BX-BY Waste Management Area at the Hanford Site in Washington. This area has been used since the late 1940s to store high-level radioactive waste and other products of U fuel-rod processing. Using multiple-collector ICP source magnetic sector mass spectrometry, high-precision uranium isotopic analyses were conducted of samples of vadose zone contamination and of groundwater. The isotope ratios 236U/238U, 234U/238U, and 238U/235U are used to distinguish contaminant sources. On the basis of the isotopic data, the source of the groundwater contamination appears to be related to a 1951 overflow event at tank BX-102 that spilled high-level U waste into the vadose zone. The U isotopic variation of the groundwater plume is a result of mixing between contaminant U from this spill and natural background U. Vadose zone U contamination at tank B-110 likely predates the recorded tank leak and can be ruled out as a significant source of groundwater contamination, based on the U isotopic composition. The locus of vadose zone contamination is displaced from the initial locus of groundwater contamination, indicating that lateral migration in the vadose zone was at least 8 times greater than vertical migration. The time evolution of the groundwater plume suggests an average U migration rate of approximately 0.7-0.8 m/day showing slight retardation relative to a groundwater flow of approximately 1 m/day. PMID:15260332

Christensen, John N; Dresel, P Evan; Conrad, Mark E; Maher, Kate; DePaolo, Donald J

2004-06-15

377

Identifying the Sources of Subsurface Contamination at the Hanford Site in Washington using High-precision Uranium Istopic Measurements  

SciTech Connect

In the mid-1990s, a groundwater plume of uranium (U) was detected in monitoring wells in the B-BX-BY Waste Management Area at the Hanford Site in Washington. This area has been used since the late 1940s to store high level radioactive waste and other products of U fuel-rod processing. Using multiple-collector ICP source magnetic sector mass spectrometry, high-precision uranium isotopic analyses were conducted of samples of vadose zone contamination and of groundwater. The isotope ratios 236U/238U, 234U/238U, and 238U/235U are used to distinguish contaminant sources. On the basis of the isotopic data, the source of the groundwater contamination appears to be related to a 1951 overflow event at tank BX-102 that spilled high-level U waste into the vadose zone. The U isotopic variation of the groundwater plume is a result of mixing between contaminant U from this spill and natural background U. Vadose zone U contamination at tank B-110 likely predates the recorded tank leak and can be ruled out as a significant source of groundwater contamination, based on the U isotopic composition. The locus of vadose zone contamination is displaced from the initial locus of groundwater contamination, indicating that lateral migration in the vadose zone was at least 8 times greater than vertical migration. The time evolution the groundwater plume suggests an average U migration rate of {approx}0.7-0.8 m/day showing slight retardation relative a groundwater flow of {approx}1 m/day.

Christensen, John N.; Dresel, P Evan; Conrad, Mark E.; Maher, Katharine; DePaolo, Donald J.

2004-06-15

378

Effects of hydrocarbon contamination on ozone generation with dielectric barrier discharges  

NASA Astrophysics Data System (ADS)

The increasing usage of the feed gases of lower grade liquid oxygen (LOX) containing higher levels of trace hydrocarbon impurities in dielectric barrier discharge (DBD) for ozone generation requires a better understanding of the kinetics of the by-product formation resulting from reactions involving these hydrocarbon impurities. As a case study of hydrocarbon impurities, the kinetics of CH4 conversion in DBDs and the subsequent HNO3 formation were investigated by means of gas-phase plasma diagnostics, supported by detailed process modeling, and extensive in-situ and ex-situ by-product analysis. The by-products formation in the plasma with the presence of CH4, were found to differ significantly in oxygen-fed generators as compared to generators fed with oxygen/nitrogen mixtures. The amount of HNO3 formed depends on the concentration of NOx formed in the plasma and the amount of CH4 that is converted, but not on the O3 concentration. In the present work we have investigated CH4 concentrations of up to 1.95 wt% of the feed gas. The rate of deterioration of the overall ozone generator performance was found to be affected by the concentration of nitrogen in the oxygen/nitrogen mixture.

Lopez, Jose L.; Vezzu, Guido; Freilich, Alfred; Paolini, Bernhard

2013-08-01

379

Effect of Sphingobium yanoikuyae B1 inoculation on bacterial community dynamics and polycyclic aromatic hydrocarbon degradation in aged and freshly PAH-contaminated soils  

Microsoft Academic Search

Sphingobium yanoikuyae B1 is able to degrade a range of polycyclic aromatic hydrocarbons (PAHs) and as a sphingomonad belongs to one of the dominant genera found in PAH-contaminated soils. We examined the ecological effect that soil inoculation with S. yanoikuyae B1 has on the native bacterial community in three different soils: aged PAH-contaminated soil from an industrial site, compost freshly

Michael Cunliffe; Michael A. Kertesz

2006-01-01

380

Screening and degrading characteristics and community structure of a high molecular weight polycyclic aromatic hydrocarbon-degrading bacterial consortium from contaminated soil  

Microsoft Academic Search

Inoculation with efficient microbes had been proved to be the most important way for the bioremediation of polluted environments. For the treatment of abandoned site of Beijing Coking Chemical Plant contaminated with high level of high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), a bacterial consortium capable of degrading HMW-PAHs, designated 1-18-1, was enriched and screened from HMW-PAHs contaminated soil. Its degrading ability

Run Sun; Jinghua Jin; Guangdong Sun; Ying Liu; Zhipei Liu

2010-01-01

381

A perspective on the benefits of the subsurface volatilization and ventilation system  

SciTech Connect

The presence of petroleum hydrocarbons, distillates, and chlorinated solvents in the subsurface environment frequently occurs from inadvertent discharges or unlawful release, and can pose a serious threat to human health and the environment. Due to strict environmental regulations, many industries are faced with significant financial and , potentially, criminal penalties associated with releases of these chemicals. In recent years, responsible industries have intensified efforts to remediate subsurface contamination problems. A new technology that addresses each aspect of subsurface contamination by volatile organic compounds (VOCs) has been developed that serves to minimize the duration and cost of remedial efforts. The Subsurface Volatilization and Ventilation System[trademark] promotes in situ destruction of contamination by biodegradation, and air circulation to enhance volatilization and vapor capture to reduce VOC mass present in the subsurface as bulk product, aqueous phase and sorbed contamination, and vapors. Because all phases of VOC contamination are addressed simultaneously, the remediation process is greatly accelerated. In addition, because SVVS[trademark] is simplistic in design and construction, remediation costs are typically well below those associated with more traditional treatment options.

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

1993-10-01

382

Influence of electron donor on the minimum sulfate concentration required for sulfate reduction in a petroleum hydrocarbon-contaminated aquifer  

USGS Publications Warehouse

Fluctuations in the availability of electron donor (petroleum hydrocarbons) affected the competition between sulfate-reducing bacteria (SRB) and methanogenic bacteria (MB) for control of electron flow in a petroleum hydrocarbon-contaminated aquifer. The data suggest that abundant electron donor availability allowed MB to sequester a portion of the electron flow even when sulfate was present in sufficient concentrations to support sulfate reduction. For example, in an area of abundant electron-donor availability, SRB appeared to be unable to sequester the electron flow from MB in the presence of 1.4 mg/L sulfate. The data also suggest that when electron-donor availability was limited, SRB outcompeted MB for available substrate at a lower concentration of sulfate than when electron donor was plentiful. For example, in an area of limited electron-donor availability, SRB appeared to maintain dominance of electron flow at sulfate concentrations less than 1 mg/L. The presence of abundant electron donor and a limited amount of sulfate reduced competition for available substrate, allowing both SRB and MB to metabolize available substrates concurrently.

Vroblesky, D. A.; Bradley, P. M.; Chapelle, F. H.

1996-01-01

383

Headspace solid-phase microextraction as a tool to estimate the contamination of smoked cheeses by polycyclic aromatic hydrocarbons.  

PubMed

Headspace solid-phase microextraction (HS-SPME) was used to study polycyclic aromatic hydrocarbons (PAH) in smoked cheeses. Two types of fiber coatings and different extraction conditions were tested. The results reveal that the use of an 85-microm polyacrylate fiber immersed in the headspace of the samples at 70 degrees C for 60 min is suitable for the detection of PAH with no more than 4 aromatic rings. To determine if a relationship can be established between the results obtained using a solvent extraction technique and HS-SPME, 6 samples of smoked cheese previously studied by a solvent extraction method were analyzed by HS-SPME, and the results obtained by both methodologies were compared. Polycyclic aromatic hydrocarbons were identified and quantified by gas chromatography-mass spectrometry operating in selective ion monitoring mode. Among the PAH determined by the solvent extraction method, only those with 4 aromatic rings or less were detected by HS-SPME and, consequently, this technique does not allow one to determine the PAH content of smoked cheese samples under the conditions of the study. Nevertheless, the relationship between the results obtained by both techniques for some PAH revealed that HS-SPME could be useful as a screening method to distinguish among samples with different degrees of PAH contamination. PMID:15591362

Guillén, M D; Sopelana, P

2005-01-01

384

In situ biosurfactant production and hydrocarbon removal by Pseudomonas putida CB-100 in bioaugmented and biostimulated oil-contaminated soil.  

PubMed

In situ biosurfactant (rhamnolipid) production by Pseudomonas putida CB-100 was achieved during a bioaugmented and biostimulated treatment to remove hydrocarbons from aged contaminated soil from oil well drilling operations. Rhamnolipid production and contaminant removal were determined for several treatments of irradiated and non-irradiated soils: nutrient addition (nitrogen and phosphorus), P. putida addition, and addition of both (P. putida and nutrients). The results were compared against a control treatment that consisted of adding only sterilized water to the soils. In treatment with native microorganisms (non-irradiated soils) supplemented with P. putida, the removal of total petroleum hydrocarbons (TPH) was 40.6%, the rhamnolipid production was 1.54 mg/kg, and a surface tension of 64 mN/m was observed as well as a negative correlation (R = -0.54; p < 0.019) between TPH concentration (mg/kg) and surface tension (mN/m), When both bacteria and nutrients were involved, TPH levels were lowered to 33.7%, and biosurfactant production and surface tension were 2.03 mg/kg and 67.3 mN/m, respectively. In irradiated soil treated with P. putida, TPH removal was 24.5% with rhamnolipid generation of 1.79 mg/kg and 65.6 mN/m of surface tension, and a correlation between bacterial growth and biosurfactant production (R = -0.64; p < 0.009) was observed. When the nutrients and P. putida were added, TPH removal was 61.1%, 1.85 mg/kg of biosurfactants were produced, and the surface tension was 55.6 mN/m. In summary, in irradiated and non-irradiated soils, in situ rhamnolipid production by P. putida enhanced TPH decontamination of the soil. PMID:24294259

Ángeles, Martínez-Toledo; Refugio, Rodríguez-Vázquez

2013-01-01

385

Airborne concentrations, skin contamination, and urinary metabolite excretion of polycyclic aromatic hydrocarbons among paving workers exposed to coal tar derived road tars  

Microsoft Academic Search

The exposure of surface dressing workers to polycyclic aromatic hydrocarbons (PAH) was studied. Four different paving sites, at which coal tar-containing binders were applied, were selected as work sites with high exposure levels of PAH. Breathing zone airborne particulates, contamination of the skin with PAH, and 1-hydroxypyrene in urine of the workers involved in chip sealing were determined. Substantial concentrations

FRANS J. JONGENEELEN; PAUL T. J. SCHEEPERS; ANITA GROENENDIJK; LEON A. G. J. M. VAN AERTS; ROB B. M. ANZION; ROBERT P. BOS; SIEBRAND J. VEENSTRA

1988-01-01

386

Effects of humic substances and soya lecithin on the aerobic bioremediation of a soil historically contaminated by polycyclic aromatic hydrocarbons (PAHs)  

Microsoft Academic Search

The high hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) strongly reduces their bioavailability in aged contaminated soils, thus limiting their bioremedia- tion. The biodegradation of PAHs in soils can be enhanced by employing surface-active agents. However, chemical surfactants are often recalcitrant and exert toxic effects in the amended soils. The effects of two biogenic materials as pollutant-mobilizing agents on the aerobic

Fabio Fava; Sara Berselli; Pellegrino Conte; Alessandro Piccolo; Leonardo Marchetti

2004-01-01

387

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

388

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

NASA Technical Reports Server (NTRS)

In this note, we show that X-ray photoelectron Spectroscopy (XPS) data and the changes in surface properties attending exposure of poly(tetrafluoroethylene) (PTFE) films to a nitrogen plasma can likewise be misinterpreted when the interfering role of minor surface hydrocarbon contamination is not taken into account.

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

1993-01-01

389

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

390

INEEL Subregional Conceptual Model Report Volume 2: Summary of Existing Knowledge of Geochemical Influences on the Fate and Transport of Contaminants in the Subsurface at the INEEL  

SciTech Connect

This document summarizes previous descriptions of geochemical system conceptual models for the vadose zone and groundwater zone (aquifer) beneath the Idaho National Engineering and Environmental Laboratory (INEEL). The primary focus is on groundwater because contaminants derived from wastes disposed at INEEL are present in groundwater, groundwater provides a pathway for potential migration to receptors, and because geochemical characteristics in and processes in the aquifer can substantially affect the movement, attenuation, and toxicity of contaminants. The secondary emphasis is perched water bodies in the vadose zone. Perched water eventually reaches the regional groundwater system, and thus processes that affect contaminants in the perched water bodies are important relative to the migration of contaminants into groundwater. Similarly, processes that affect solutes during transport from nearsurface disposal facilities downward through the vadose zone to the aquifer are relevant. Sediments in the vadose zone can affect both water and solute transport by restricting the downward migration of water sufficiently that a perched water body forms, and by retarding solute migration via ion exchange. Geochemical conceptual models have been prepared by a variety of researchers for different purposes. They have been published in documents prepared by INEEL contractors, the United States Geological Survey (USGS), academic researchers, and others. The documents themselves are INEEL and USGS reports, and articles in technical journals. The documents reviewed were selected from citation lists generated by searching the INEEL Technical Library, the INEEL Environmental Restoration Optical Imaging System, and the ISI Web of Science databases. The citation lists were generated using the keywords ground water, groundwater, chemistry, geochemistry, contaminant, INEL, INEEL, and Idaho. In addition, a list of USGS documents that pertain to the INEEL was obtained and manually searched. The documents that appeared to be the most pertinent were selected from further review. These documents are tabulated in the citation list. This report summarizes existing geochemical conceptual models, but does not attempt to generate a new conceptual model or select the ''right'' model. This document is organized as follows. Geochemical models are described in general in Section 2. Geochemical processes that control the transport and fate of contaminants introduced into groundwater are described in Section 3. The natural geochemistry of the Eastern Snake River Plain Aquifer (SRPA) is described in Section 4. The effect of waste disposal on the INEEL subsurface is described in Section 5. The geochemical behavior of the major contaminants is described in Section 6. Section 7 describes the site-specific geochemical models developed for various INEEL facilities.

Paul L. Wichlacz; Robert C. Starr; Brennon Orr

2003-09-01

391

Contamination, source identification, and risk assessment of polycyclic aromatic hydrocarbons in agricultural soil of Shanghai, China  

Microsoft Academic Search

The level, distribution, compositional pattern, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural\\u000a soil of Shanghai were investigated. The concentrations ranged from 140.7 to 2,370.8 ?g kg???1 for 21 PAHs and from 92.2 to 2,062.7 ?g kg???1 for 16 priority PAHs, respectively. The higher level of PAHs was mainly distributed in the south and west of Shanghai region,\\u000a and the lower concentration

YuFeng Jiang; XueTong Wang; MingHong Wu; GuoYing Sheng; JiaMo Fu

392

Hydrocarbon wastes at petroleum- and creosote-contaminated sites. Rapid characterization of component classes by thin-layer chromatography with flame ionization detection  

SciTech Connect

Adaptation of thin-layer chromatography with flame ionization detection for the semiquantitative characterization of residual hydrocarbon contamination at petroleum and wood-preserving hazardous waste sites is described. Soils collected from an abandoned oilfield battery site and a former creosote wood treatment facility in Alberta were solvent extracted and the residues characterized using two mobile-phase systems, one capable of separating polar waste components and the other of separating constituent aromatics according to ring number. The method provides a rapid component class fingerprint of the saturate, aromatic, and polar components of heavy hydrocarbon wastes, is analogous to column chromatography, and is useful for estimating the extent of weathering experienced by aged hydrocarbon wastes in the soil environment. As such, it can be useful for preliminary screening of the potential biotreatability or inherent recalcitrance of hydrocarbon waste mixtures. 34 refs., 7 figs., 4 tabs.

Pollard, S.J.; Hrudey, S.E. (Univ. of Alberta, Edmonton, Alberta (Canada)); Fuhr, B.J.; Alex, R.F.; Holloway, L.R.; Tosto, F. (Oil Sands and Hydrocarbon Recovery Analytical Lab., Edmonton, Alberta (Canada))

1992-12-01

393

Mapping subsurface pathways for contaminant migration at a proposed low level waste disposal site using electromagnetic methods  

SciTech Connect

Electromagnetic methods have been used to measure apparent terrain conductivity in the downstream portion of a watershed in which a waste disposal site is proposed. At that site, the pathways for waste migration in ground water are controlled by subsurface channels. The channels are identified using isocurves of measured apparent conductivity. Two upstream channel branches are found to merge into a single downstream channel which constitutes the main drainage path out of the watershed. The identification and mapping of the ground water pathways is an important contribution to the site characterization study and the pathways analysis. The direct applications of terrain conductivity mapping to the planning of the monitoring program, the hydrogeological testing, and the modeling study are demonstrated. 7 references, 4 figures.

Pin, F.G.; Ketelle, R.H.

1984-01-01

394

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

395

IN SITU APPARENT CONDUCTIVITY MEASUREMENTS AND MICROBIAL POPULATION DISTRIBUTION AT A HYDROCARBON CONTAMINATED SITE  

EPA Science Inventory

We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light non-aqueous phase liquid (LNAPL). The bulk conductivity was measured using in situ vertical resistivity probes, while the most probable number met...

396

Contamination of animal feed and food from animal origin with mineral oil hydrocarbons.  

PubMed

Oils and fats used for the production of animal feed can become contaminated with mineral oil material originating from gas oils (C18-C35) or synthetic oils (poly-alpha olefins, C25 to beyond C45). An important cause is assumed to be the discharge of waste oils, such as motor oil and hydraulic oils. Mineral oil material was analysed by on-line LC-GC-FID directly in the fat or in a raw extract from animal feed or foodstuffs. In Switzerland in summer/autumn 1999 concentrations in oils and fats for feed production were often found to be between 100 and 1000 mg/kg. In the feeds, the average concentration was around 100 mg/kg with values ranging up to a maximum of 1000 mg/kg; few samples were free of contamination. In animal body fat, the average concentration determined in summer 1999 was 25 mg/kg, with a maximum of 150 mg/kg, although in samples from December 1999, contamination was substantially lower. In the fat phase of eggs, the average concentration was 30 mg/kg, with a maximum of 80 mg/kg. Paraffin oil is used for feed production, which may account for part of the contamination problem (e.g. eggs). PMID:11212542

Grob, K; Vass, M; Biedermann, M; Neukom, H P

2001-01-01

397

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

398

DEVELOPMENT OF RADON-222 AS A NATURAL TRACER FOR MONITORING THE REMEDIATION OF NAPL CONTAMINATION IN THE SUBSURFACE  

EPA Science Inventory

One of the major obstacles preventing cost-effective cleanup of many DOE sites is the current inability to accurately locate and quantify residual nonaqueous phase liquid (NAPL) contamination. The recently developed natural radon tracer method has the potential to provide a rapid...

399

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...

400

Volatile hydrocarbons inhibit methanogenic crude oil degradation.  

PubMed

Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene, and xylenes) were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34) and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene) were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales) were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 ?mol CH4/g sediment/day) with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34). For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 ?mol CH4/g sediment/day). This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers. PMID:24765087

Sherry, Angela; Grant, Russell J; Aitken, Carolyn M; Jones, D Martin; Head, Ian M; Gray, Neil D

2014-01-01

401

Effects of Nonionic Surfactant Addition on Populations of Polycyclic Aromatic Hydrocarbon-Degrading Bacteria in a Bioreactor Treating Contaminated Soil  

PubMed Central

We studied the effects of two polyethoxylated nonionic surfactants, Brij 30 and C12E8, on populations of polycyclic aromatic hydrocarbon- (PAH-) degrading bacteria from a bioreactor treating PAH-contaminated soil. Each surfactant was evaluated at doses that corresponded to aqueous-phase concentrations both above and below the critical micelle concentration (CMC) after mixing with reactor slurry. Real-time quantitative PCR was used to quantify 16S ribosomal RNA (rRNA) gene sequences representing degraders of salicylate, naphthalene, phenanthrene or pyrene previou